Tumor comprises of heterogeneous population of cells where not all the disseminated cancer cells have the prerogative and “in-build genetic cues” to form secondary tumors. Cells with stem like properties complemented by key signaling molecules clearly have shown to exhibit selective growth advantage to form tumors at distant metastatic sites. Thus, defining the role of cancer stem cells (CSC) in tumorigenesis and metastasis is emerging as a major thrust area for therapeutic intervention. Precise relationship and regulatory mechanisms operating in various signal transduction pathways during cancer dissemination, extravasation and angiogenesis still remain largely enigmatic. How the crosstalk amongst circulating tumor cells (CTC), epithelial mesenchymal transition (EMT) process and CSC is coordinated for initiating the metastasis at secondary tissues, and during cancer relapse could be of great therapeutic interest. The signal transduction mechanisms facilitating the dissemination, infiltration of CSC into blood stream, extravasations, progression of metastasis phenotype and angiogenesis, at distant organs, are the key pathologically important vulnerabilities being elucidated. Therefore, current new drug discovery focus has shifted towards finding “key driver genes” operating in parallel signaling pathways, during quiescence, survival and maintenance of stemness in CSC. Understanding these mechanisms could open new horizons for tackling the issue of cancer recurrence and metastasis-the cause of ~90% cancer associated mortality. To design futuristic & targeted therapies, we propose a multi-pronged strategy involving small molecules, RNA interference, vaccines, antibodies and other biotechnological modalities against CSC and the metastatic signal transduction cascade. Metastasis is the result of dissemination of primary cancer tissue cells that go on to initiate and colonize at distant secondary tissue sites. Cancer cells purportedly disseminate from tumors in hoards and establish new tumors in distant organs , 2. Metaen masse. The documentation of clinically significant metastatic genes and properties has enhanced the biological understanding of metastasis and its distinctive stages [Tumor comprises of heterogeneous population of cells. This intratumoral heterogeneity leads to an organized hierarchy corresponding to the spatial structure of a normal tissue, self-renewing cancer stem cells, progenitor cells and tumor cells. The identification of CSC within a subpopulation with enhanced tumor initiating and growth promoting cells has led to major improvements in our understanding about how individual tumor's cellular architectural components might be vulnerable for targeted therapies. Self-renewal, invasiveness and tumor progression that were once attributed to tumor cells in general have been tracked down to a fraction of cancer cells within the tumor bulk. Hence, the role of CSC in metastasis is understandably significant and therapeutically remains a challenge. Tumor initiation by disseminated cancer cells depends on their ability to self-renew and initiate metastatic tumors, the very same properties that are attributable to CSC are intrinsic to cancer metastasis. Presence of CSC, initially identified in hematopoietic cancers , 4 has ne stages , 21. Hige stages .CSC, unlike progenitor cells are responsible for long-term tumor growth and remains recalcitrant to currently available therapeutic options. This is analogous to normal stem cells that maintain tissues homeostasis. This small population of CSC existing in tumors may well be the cause of metastases, as these cells are known to from secondary tumors in immunodeficient mouse models. The metastatic niche & EMT act in synergy with signaling transduction pathways known to regulate CSC properties and metastasis as cancer cells with stem cell surface markers are proven to promote metastasis.Herein, we outline current knowhow and future directions of the molecular biology of metastatic tumor growth, by focusing mainly on signaling pathways that allow metastatic CSC to survive under hostile conditions, continue infiltration into bloodstream and initiate tumors at distant organs. How these pathways might provide an opportunistic window and genetically susceptible regulatory mechanisms for targeted drug discovery & development remains largely unexplored territory? It is important to mention here that our knowledge of the mechanisms that underlie metastasis are still in its infancy and the discussion in this review mainly focuses on the findings from animal models, which often are unable to mimic the processes in human patients. It is our hope that the knowledge about how CSC, CTC, EMT and other regulatory loops coalesce to form metastases will ultimately be useful in defining new therapeutic strategies.Metastatic CSC (mCSC) are unique in their own intricacy, intravasation of disseminated cancer cells from its primary source of origin, extravasation into different organs and covert colonization after a latent phase has clear hallmarks that normal disseminated cancer cells are not able to achieve. Not all migrating cancer cells or CSC with metastatic potential are able to initiate tumors at distant organ sites due to the fact, that most of the disseminated cells are usually gone too far down the pathway of differentiation. The mCSC either exist and extravagate or, might be derived from disseminated tumor cells, which reacquire stemness to initiate tumors in distant organs , 24. Lac0 phase of the cell cycle and fail to proliferate as a potential source of tumor propagating entities. Perhaps it is a failure of these cancer cells to metastasize and form new tumors or a defense mechanism to avoid unwanted immune response when the odds are stacked up against them [via signaling pathways that directs tumor cells on how and when to proliferative depending on the difficulties these disseminated cells might face. This was evident in breast cancer where Bone Morphogenic Protein (BMP) signals lung parenchyma to enforce dormancy, suppression of self-renewal and encouraging differentiation. Coco, a BMP antagonist suppresses BMP via sequestration and hence counteracts latency [Cancer cells with the ability to from distant tumors in other parts of body can remain dormant for years despite the removal of primary tumor by surgery or other pharmacological approaches. How disseminated CSC remain latent, and play crucial role of stromal signaling and cell-cell interactions in maintaining quiescence remains elusive. Mouse models are unable to mimic the intricate process of dormancy and reactivation that is observed in human patients, where latency can last from months to years. Based on experimental evidence on what we know so far, it is still uncertain whether metastatic niche and molecular pathways that initiate metastasis are required before, during or after metastasis, once the cells pass through dormancy. Disseminated tumor cells (DTC) found in bone marrow were shown to be in dormant stage in terms of their tumorigenic ability , 26 and nst them , 28. Thinst them , 30. Per latency .Two important caveats need to be addressed before therapies targeting CSC and mCSC could be considered. The CSC follow the same molecular blue print as normal stem cells necessitating the importance of strategies that would discriminate CSC from normal stem cells. Currently it is unclear if drugs developed to target CSC would not target normal stem cells on the pretext of increased proliferation by CSC. Understanding the genetic networks and associated cellular & environmental factors might specifically pinpoint towards the intricacies of CSC and normal stem cells, and ultimately open up a new therapeutic window for targeted therapies , 33. ObvConsiderable progress has been made to understand how cancer heterogeneity behaves and in unravelling of the genetic mechanisms operating during tumor development. Cancer heterogeneity in many instances seems to be due to the hierarchical organization that a tumor follows. This hierarchical tree follows the same basic principles of organ development and resembles closely to the kinetics of tumor growth. The CSC encompassing the top of this hierarchy resemble the normal stem cells in terms of phenotype and functionality with additional oncogenic mutations as tumor progresses. CSC not just self-renew their own population but also give rise to a progeny of partially or completely differentiated cells. Lineage tracking studies in mouse models provided genetic evidence that primary tumors of colon, brain and skin follow the hierarchical organization of their tissue of origin , 15, 33.Convincing evidence for a lineage relationship among CSC, adult stem cells and mCSC were obtained from studies on colorectal cancer. These mechanistic studies revealed that upon acquiring genetic alterations in WNT pathway, intestinal stem cells gave rise to adenomas . CSC resEMT is fundamental to embryogenesis, especially in tissue invasion and neural crest formation or gastrulation . A numbeFor disseminated cancer cells, it is important to locate and proliferate in organ site(s) that would be supportive, just like stem cells in an adult tissue. Stem cells reside in specialized site termed as niches, which provide molecular and cellular signals to promote self-renewal capabilities as well as differentiation of stem cells, as and when required. Niches have been characterized in numerous tissues, like hematopoietic bone marrow, intestinal epithelium, brain and epidermis –59. CSC Disseminated cancer cells may end up in random locations in parenchyma but recent findings suggest a growing possibility of occupation of stem cell niches by disseminated CSC. For instance, prostate cancer cells exhibit tendency to occupy hematopoietic stem cell niche to exploit it for its own viability, growth and sustainability . Other lDistant organs are prone to influence by the primary tumors, which could lead to the establishment of a pre-metastatic niche formation . This haWith the passage of time, tumors tend to get rigid and this stiffness is often attributed to ECM. The rigidity provided by ECM activates the expression of focal adhesion molecule (FAK) and PI3K-AKT by cancer cells that are also observed in mCSC . Lysyl oGlycosaminoglycan hyaluronan is another ECM component that binds to cell surface receptor-CD44 of breast cancer cells and inhibits apoptosis during lung metastasis in mouse models . The binvia Ezrin after its engagement with α-4 integrins [Not all disseminated tumor cells that invade another tissue survive. Disseminated tumor cells should either avoid harmful stromal signals or in response, over-express anti-apoptotic & survival pathway genes and be “deaf” to death signals. This has been documented for brain metastasizing cells that up-regulate the expression of serpins to inhibit plasmin expression by astrocytes, thus preventing lethal FasL signaling  and circntegrins . Clinicantegrins  whereas ntegrins , 82. Thuntegrins  and othentegrins  stressedntegrins . Interacntegrins , 86. Outntegrins , 88. Anontegrins –91. Mostntegrins .via Wnt and Notch pathways [Stem cell niches in bone marrow, intestinal mucosa and brain, promote plasticity/stemness pathways , 58, 62.pathways , 82. In CSC generally require additional set of mutations in order to successfully initiate and develop metastatic tumors. Xenotransplantation of stage IIIB/C human melanoma cells from patients with metastatic melanoma in mice has been shown to form lesions and metastasis occurred in mice with these tumor xenografts . This stRecent efforts to sequence cancer genomes have further revealed extensive genetic variations within tumors from the same issue. This heterogeneity causes phenotypic variations, modulate various signaling pathways and reduce the efficacy of cancer drugs due to variable gene expression profile of these tumors. These studies have identified around 140 genes that, when modified by mutations can promote tumorigenesis –100.Mutations in pathways regulated epigenetically, might also play important role in supporting and enhancing metastasis. Mutational changes in epigenetic regulators or metabolic signaling pathways (Isocitrate dehydrogenases-IDH1 and IDH2) that enhance the epigenetic signals could trigger a selection pressure, favoring proliferative and aggressive phenotypes , 102. ThVariations in machinery regarding mRNA processing, non-coding RNAs and translation can also enhance the metastatic traits of cancer cells , 105–108Notch pathway has immense importance in terms of cell fate determination, angiogenesis, CSC and tumor immunity. Notch signaling is predominantly involved in cell-cell communication between adjacent cells through transmembrane receptors and ligands , 110. Thvia paracrine or autocrine routes [Hedgehog (HH) pathway is pivotal to tissue patterning in embryos and tissue repair as well as EMT . The inhe routes . Activate routes . Recent e routes . Moreovee routes . RhabdomThe HH signaling, similar to Notch signaling pathway involves canonical and non-canonical pathways. Canonical axis involves PTCH1-SMO-GLI while non-canonical could be independent of SMO . Non-canThere are three major pathways of Wnt-signaling cascade; canonical Wnt signaling pathway that involves β-catenin, T-cell-specific transcription factor (TCF) and lymphoid enhancer-binding factor (LEF) axis, which has been implicated in tumorigenesis and two non-canonical pathways; planar cell polarity signaling pathway that regulates the cytoskeleton and Wnt/calcium pathway, which is involved in intracellular calcium regulation. Understanding of the Wnt canonical pathway has led to increased interest in developing therapeutic strategies for its inhibition in cancer.via segment polarity protein i.e. disheveled homologue (Dvl) phosphoprotein, which is localized in cytoplasm. Once activated, Dvl inhibits β-catenin phosphorylation, mediated by Axin[Inhibition of Wnt, HH and Notch signaling pathways has certainly led to the development of promising therapies that would interfere with tumor progression and metastasis Table . Wnt ligd by AxinA multiprd by Axin.Preclinid by Axin. It has d by Axin. Moreoved by Axin and EMT d by Axin. Hence, Establishing a correlation between CSC and metastasis could have an immense implication on the future cancer treatment. Model experiments stress the importance of taking preventive measurements earlier than what is practiced by oncologists currently. The notion that stem cells are quiescent, seldom divide and have distinctive properties as compared to the main population of a tumor in conjunction with the ability to express higher levels of drug transporter proteins to flush out chemotherapeutic drugs, has necessitated the development of new drugs to target CSC . The abitrans-retinoic acid had been used as an inducer of differentiation in patients with acute premyelocytic leukemia with higher success rate. Additionally, TPA, butyric acid, vitamin D3, and DMSO have also been used for solid tumors, though using targeted remedies, for instance, PPARα activator, nerve growth factors or compounds like vesnarinone may turn out to be more effective [Considering that CSC are paramount to the growth of primary tumor and metastasis, it seems logical to target the self-renewal capabilities of these cells. Therapies targeting self-renewal modalities developed hitherto, cyclopamine targeting the hedgehog, exisulind, imatinib, and bromoindirubin-3'-oxime, affecting the Wnt/β-catenin signaling pathways have had varying degrees of success. On the contrary, we could argue that, inducing differentiation in CSC would technically eliminate their propensity to self-renewal. Clinically all ffective . Understvia ABC transporter genes, a group of drug transporter genes and other unknown cellular mechanisms that provide them defense against small molecule drugs. Chemotherapy and other therapeutic approaches that could inhibit the efflux of drugs out of CSC, by hindering the ABC transporter genes might lead to increased susceptibility of tumors to current or new therapies. One such attempt was made by inhibiting ABCB1 transporter with limited success, though scientists are hopeful that inhibitors of ABCG2 might turn out to be a success story in future [Tumor cells and CSC are inherently known to flush out drugs n future .Not all metastasizing cancer cells generate secondary tumors, and it appears that only CSC have the prerogative to undertake such a task. Hence, targeting CSC at the initial stages of metastasis could drastically reduce progression of a tumor in metastatic niche. Such has been the case in animal models where inhibiting CXCR4, a homing factor, prevented the formation of primary tumor in addition to blocking metastasis . This imBy the time a primary tumor is normally detected metastasizing cells have already been migrating to secondary site(s) or pre-metastatic niche has already been set up. Under such circumstances, blocking the reactivation of quiescent metastatic CSC could be an attractive therapeutic strategy. Such therapies are far from reality, as appropriate animal models depicting dormancy are required for further validation and proof-of-concept studies. Understanding the process of reactivation and factors associated with metastatic niche, would certainly help in developing safe and potent drugs.With the development of the Human Genome Sequence data blueprint in 2001, systematic gene expression profiling (GEP) efforts were directed towards normal and tumor tissues, to elucidate molecular signatures required to classify these tumors based on the genomics data as well as delineate various stages of carcinogenesis. In the last few years, for example, The Cancer Genome Atlas (TCGA) and other networks have reported four main subtypes of breast cancers, after detailed analyses of different genetic and epigenetic abnormalities observed in these tumors . This coA combination therapy may be a way forward, where either 2 small molecules, or one small molecule and one biotechnology based drug, or more recently employing RNAi technology for targeting key driver genes , seems fAnother major challenge faced by the Pharmaceutical/Biotechnology companies is the safety and toxicity of NCEs resulting in high attrition rates during clinical drug development process. Individually or in combination-toxicogenomics, NGS and CRISPR-cas9 technologies, need to be leveraged early in drug discovery and pre-clinical development in appropriate animal models to identify and circumvent drug-induced toxicity issues. From personalized medicine point of view, how and where we can employ RNAi/CRISPR gene editing protocols for identifying, characterizing and targeting gene(s) responsible for intravasation to extravasation, dissemination and ultimate colonization of CSC & tumor cells at distant sites remains to be experimentally exploited and validated. A system biology level understanding of TCGA datasets along with better biomarkers to predict toxicity will certainly go a long way in customizing therapeutic options based on the GEP of the individual tumors. This will require collaboration and sharing of data from academic labs, industry, NGOs, regulatory bodies and other stakeholders to create systems and processes, wherein these data sets are available freely in the public domain, something on the lines of NCBI. Of particular interest will be the drugs, which fail in phase II/III and the lessons learnt, which need to be incorporated in future NDDRD programs. If successful strategies are designed and carried out after careful analyses of “repurposed drug molecules” some of these failed therapies might prove beneficial for another type of cancer, or another disease indication, based on critical evaluation of GEP datasets. Taken together, building on new mechanistic insights into metastasis, we need to make sure that future NDDRD is not done in isolation but in collaboration, where the cancer patient will be the ultimate beneficiary.


There is considerable interest in the physiology and pathology, as well as the cellular and molecular biology, of bone marrow adipose tissue (BMAT). Because bone marrow adiposity is linked not only to systemic energy metabolism, but also to both bone marrow and musculoskeletal disorders, this biologic compartment has become of major interest to investigators from diverse disciplines. Bone marrow adiposity represents a virtual multi-tissue endocrine organ, which encompasses cells from multiple developmental lineages  and occupies all the non-osseous and non-cartilaginous space within long bones. A number of research groups are now focusing on bone marrow adiposity to understand a range of clinical afflictions associated with bone marrow disorders and to consider mechanisms-based strategies for future therapies. The topics assembled here were initially discussed at the Second International Meeting on Bone Marrow Adiposity (BMA) in Rotterdam, Netherlands  and provide a broad overview of the current state of the field. These meeting notes contain informal conclusions and are intended to encourage the reader to explore them further in literature or by performing own experiments. This meeting was a follow-up of the 1st BMA meeting held in Lille, France.in vitro displayed a dramatic increase in adipogenic differentiation at the expense of osteogenic differentiation.Bone marrow stromal cells (BMSCs) are a heterogeneous group of plastic-adherent cells that include multipotent progenitors. A subset of these cells has the capacity to self-renew and the potential to generate several cell types. BMSCs are related to a much broader group of precursor cells commonly referred to as mesenchymal stem/stromal cells (MSCs), which are ubiquitous fibroblastic cells that can be harvested from many tissues. From a bone perspective, one of the biologically more interesting cell types within a BMSC population is the skeletal stem cell (SSC).Whether bone marrow-derived adipocytes share characteristics of peripheral fat cells  is still a matter of debate. The adipose organ displays a high degree of plasticity: cold exposure increases the mass and activity of brown adipose tissue (BAT), while an excess in energy enlarges the white adipose tissue (WAT). This observation suggests that adipocytes are prone to convert reversibly under physiologic stimuli to preserve the homeostasis of the organism.The molecular mechanisms controlling stem cell fate and lineage-commitment are fundamental to our understanding of bone marrow adiposity. The biologic properties of the multipotent cells that generate mesenchymal tissues , both during pre- and post-natal development, have remained more elusive than those of pluripotent embryonic stem cells, which are well-defined cells derived from the inner cell mass of blastocysts that can form all somatic tissues and germ-line cells in adult animals. It is well-accepted that the regenerative capacity of these cells declines with age, thus reducing their ability to support musculoskeletal tissue repair. Furthermore, loss of bone in elderly osteoporotic patients frequently occurs concomitantly with increased bone marrow fat. These changes in tissue repair and homeostasis ultimately are associated at the cellular level with mechanisms of self-renewal and cell fate determination in the mesenchymal lineage.in vivo in mouse models with functional mutations that affect either osteogenic or adipogenic lineage differentiation. As mentioned above, at the meeting, several lines of published and unpublished evidence in support of this concept were informally discussed, and are presented here without citable sources of information merely to provide a flavor of the argumentation and the current thinking in the field. First, unscheduled activation of PTH/PTHrP signaling in SSCs suppresses the Wnt inhibitor sclerostin. This suppression results in activation of the osteogenic WNT signaling pathway resulting in excessive bone formation. Second, over-production of erythropoietin by mesenchymal stromal cells (including SSCs), which support hematopoiesis, causes decreased adipocyte formation. Third, mature osteogenic cells exhibit decreased expression of MMP14 (MT-MMP1), which prevents cleavage of a non-canonical ligand for Notch signaling  that is inhibitory for adipogenesis and resides in the extracellular region of osteoblasts. The sequestration of DLK1 on the osteoblast surface precludes its release and the loss of its inhibitory function in adipogenesis contributes to increased bone marrow fat. Fourth, in dyskeratosis congenita,Recent studies indicate that regulation of cell fate in SSCs may be central to maintaining balanced levels of bone marrow adiposity. This premise is based on several key observations made Consistent with the importance of paracrine signaling, studies by Clabaut and colleagues suggest that adipocytes originating from MSCs may promote trans-differentiation (or re-programming) of osteogenic cells derived from MSCs. This trans-differentiation is presumably due to activation of OCT4 (POU5F1) and PPARϒ2 (PPARG), as well as epigenetic changes in CpG methylation due to as-yet undefined adipokines secreted by adipocytes. Studies by van Eerden and colleagues suggest that osteogenic differentiation of MSCs may involve a positive feed-back loop featuring auto/paracrine production of leptin. Hence, osteogenic vs. adipogenic lineage commitment may be the net result of multiple competing growth factors and morphogens that interact with the cell surface of uncommitted and/or pre-committed mesenchymal cells.Beyond cell-surface-mediated events that involve complex ligand/receptor interactions, MSCs from different sources exhibit major differences in the expression of nuclear proteins that control transcription of mRNAs and their subsequent processing. Unpublished RNA-seq data obtained for blood-vessel-associated pericytes from peripheral adipose-tissue vs. bone marrow revealed hundreds of differentially expressed genes, and several tens of transcription factors and RNA binding proteins that are distinct between the 2 MSC types. These studies showed evidence of novel DNA- and RNA-binding proteins that are selectively upregulated in adipose-derived MSCs, and that are necessary for adipogenic but not osteogenic differentiation. These findings suggest that MSCs from adipose-tissue selectively activate key regulatory proteins for adipogenic differentiation, presumably to prime these cells for repair or expansion of the tissue in which they are embedded.Collectively, recent studies in the field indicate that clinical perturbations in bone marrow adiposity affect paracrine signaling among mesenchymal and non-mesenchymal cells at different levels of lineage maturation. These paracrine events clearly drive self-renewal and cell fate of mesenchymal cells, and may favor normal lineage progression (programming) or trans-differentiation (re-programming) by altering epigenetic events, as well as expression of both DNA- and RNA-binding gene regulatory factors.BMAT increases with aging and in diverse clinical conditions such as osteoporosis, anorexia nervosa and caloric restriction, Cushing's syndrome, estrogen deficiency, glucocorticoid therapy, and perhaps in obesity and diabetes.BMA2016 provided new insights to these questions. Aging has an important influence on bone structure and function, and is a factor with a sex-dependent component related to temporal changes in gonadal hormone production. Osteoporosis is a significant health problem for which postmenopausal women are most vulnerable. Gina Woods reported her group's analysis of the AGES study  of older subjects (∼78–79 y old), which revealed that free estradiol negatively correlates with vertebral BMAT in males but not females. This is consistent with the concept that estrogens suppress BMAT formation (at least in elderly men) and indicates a potential mechanism for the sex-dependent effects of estrogen. Also, treatment of postmenopausal women with 17β-estradiol decreases BMAT within 2 weeks, independent of changes in bone mass.Several reports presented at In addition to aging and osteoporosis, there is much interest in the relationship between BMAT and obesity. Indeed, obesity is defined by excessive adiposity and is associated with metabolic and endocrine dysregulationUcp1 transcripts in whole bones, leading to speculation that BMAT has BAT-like characteristics.The obesity pandemic has motivated a surge of research into BAT, which, via uncoupling protein 1 (UCP1), can mediate adaptive thermogenesis and thereby enhance energy expenditure. As such, there is now much interest in the relationship between ambient temperature, adiposity, and metabolic function.et al. in rabbits and rats further revealed that CR decreases leptin expression but increases adiponectin expression in tibial BMAT, suggesting that CR directly alters the endocrine properties of BMAT.Several reports addressed the function of BMAT during caloric restriction (CR). In the mouse SBA model of anorexia, it was found that there is a significant positive correlation between BMAT volume and circulating adiponectin. Conversely, CR in rabbits does not increase BMAT or circulating adiponectin,The endocrine causes of BMAT accumulation during CR also remain unresolved. Olfa Ghali reported that SBA mice have increased BMAT, and their BMSCs have elevated expression of adipocyte genes  and increased acetylation of Runx2 and Foxo1; these effects also occur in BMSCs following Sirt1 inhibition. Thus, SBA suppresses Sirt1, resulting in increased acetylation of Runx2 and Foxo1, and possibly stimulation of local glucocorticoid activity. Consistent with this finding, CR-induced increases in BMAT are associated with glucocorticoid excess but can occur without hypoleptinaemia.The above studies have focused on CR in non-obese animal models. One recent paper shows that, in obese mice, weight loss limits BMAT accumulation.Pth1r) in MSCs. These mice had substantially increased BMAT, high Rankl/Tnfsf11 expression in BMAT, and increased Rankl protein in serum and bone marrow; however, no Rankl was detected in peripheral adipose depots. This suggests that BMAT can influence circulating Rankl concentrations, highlighting a novel potential endocrine function of BMAT.Finally, Beate Lanske studied a mouse model with conditional deletion of the PTH receptor  insufficiency. However, the direct role of BMAT on the regulation of HSCs and the subsequent production of the different haematopoietic lineages within the bone marrow is still ill defined. Naveiras and colleagues determined a net negative effect of bone marrow-derived adipocytes in hematopoiesis, both in homeostasis and upon stress-induced hematopoiesis following irradiation-mediated aplasia. More specifically, their work demonstrated that highly adipocytic areas within the marrow were significantly depleted in short-term HSCs and progenitors, as were HSCs co-cultured with fully differentiated adipocytes. Of note, long-term HSC activity remained unchanged after co-culture with either preadipocytes or fully mature adipocytes. Pharmacological or genetically-engineered adipocytic inhibition upon radiation-induced aplasia significantly accelerated haematopoietic recovery after HSC transplantation while enhancing new bone deposition. Others have since validated both the reduced supportive capacity of bone marrow derived mature adipocytesIn the particular case of aplastic anemia, characterized by massive adipocytic infiltration upon autoimmune HSC insult, a direct effect of PPARG inhibitors in T cell function has also been demonstrated.in vivo imaging or histological reconstruction at the single cell level, has led to much controversy regarding the nature of the cellular components that directly associate with haematopoietic stem cells (HSCs), constituting the so-called HSC niche. HSCs were first functionally and geographically associated to osteoblasts and the endostium. It has since been determined that although osteoblasts can produce trophic factors that favor HSC maintenance indirectly via the PTH receptor (Pth1r), calcium–sensing mechanisms, N-cadherin interactions and osteopontin, it is mainly Leptin receptor postive perivascular cells (Lepr+) within the highly vascularized endostium that are functionally required for HSC survival through secretion of high levels of CXCL12 for retention and SCF, angiopoietins as well as IGF-like proteins as HSC trophic factors. In parallel, distinct perivascular nestinGFP cells with mesenchymal stem cell (MSC) properties have also been shown necessary and sufficient for HSC self-renewal in vivo.GFP MSCs overlap with the histologically distinct CXCL12-high adventicial reticular cells (CARs) known to associate with HSCs within the bone marrow.Mechanistically, how these findings integrate the recent understanding of the HSC niche is still an open question. The inherent 3D structure of the haematopoietic stem cell (HSC) niche embedded within the bone marrow, hardly accessible for in vitro system to mimic the yellow-to-red marrow transition to uncover novel promoters of the yellow-to-red bone marrow transition. Using Digital Holographic Microscopy, they screened the Prestwick Chemical Library of FDA-approved drugs and natural compounds for inhibitors of adipocytic differentiation to accelerate the yellow–to-red marrow transition to improve post-transplant survival. Also they developed and optimized a semi-automated image analysis (MarrowQuant ImageJ Plug-In) that allows for unbiased quantification and size distribution of bone marrow adipocytes in vivo from stained bone marrow sections. These approaches have great potential for improving our understanding of the relationship between BMAT and hematopoiesis.The Naveiras group also presented an Collectively, the data discussed in the meeting is compatible with the scenario that mature adipocytes, and thus BMAT, prevent the rapid expansion of short-term haematopoietic progenitors while supporting the survival of the most primitive HSC compartment. Contrarily, the preadipocytic Lepr+, CXCL12+ adventitial reticular cells would be responsible for HSC proliferation. Further research is needed to elucidate the specific mechanisms responsible for the differential regulation of adult hematopoiesis throughout the adipocytic differentiation axis, and to determine how deregulation of the adipocytic axis may contribute to the microenvironment-guided initiation or progression of haematopoietic malignancies, as previously demonstrated for osteoblastic and neural-derived signaling within the bone marrow.In vitro co-culture systems have revealed a range of potential mechanisms, including lipid transfer from adipocytes to prostate cancer cells, which promotes growth and invasion of the metastasizing cancer cells. Combining a murine model of prostate cancer bone metastases with a high-fat diet revealed a change in tumor cell metabolism toward the Warburg phenotype, with increased glycolytic enzymes, increased lactate production and decreased oxidative phosphorylation. This finding was supported by in silico analysis of patients with metastatic prostate cancer, where an increase in genes associated with the Warburg effect was detected.In vivo studies using a murine model of myeloma have now identified distinct changes in bone marrow-derived adipocytes within the myeloma-bone microenvironment. For example, in vitro co-cultures of myeloma cells and bone marrow-derived adipocytes show that adipocytes promote myeloma cell growth and survival. Similarly, bone marrow-derived adipocytes were found to transfer lipid to leukemic blasts and thereby promote AML proliferation, a biologic effect that uses novel mechanisms mediated by the FABP4 transporter protein in bone marrow-derived adipocytes, and CPT1 in leukemic blasts. It is becoming increasingly evident that bone marrow-derived adipocytes are ideally placed to interact with tumor cells and contribute to the tumor-bone microenvironment. As such, elucidating the relationship between these cell types represents a new avenue to explore novel therapeutic targets for the treatment of these deadly malignancies.It has long been known that interactions between cancer cells and cells of the host bone marrow microenvironment are essential to drive both cancer-induced bone disease and tumor growth and survival. The contributions of osteoblasts and osteoclasts to this relationship are well documented but the role of bone marrow-derived adipocytes remains largely unexplored. Since both the incidence of bone metastases and the proportion of bone marrow-derived adipocytes increase with age, it is tempting to speculate that bone marrow-derived adipocytes may play an important role in supporting tumor cell survival within bone. Murine models have demonstrated that increasing bone marrow adiposity promotes the progression of osteolytic prostate cancer growth within bone.in vivo. Although young C57BL/6 mice are largely devoid of BM adipocytes, a small number of perilipin(Plin1)-positive:osterix (Osx1/Sp7) traced cells were observed in the bone marrow of 8-week-old mice.Several recent studies have focused on identifying the bone marrow adipocyte-osteoblast progenitor cell In several conditions, including aging and osteoporosis, the tendency of MSCs to differentiate toward osteoblasts switches in favor of adipogenesis. Of interest, mice held at temperatures below 26°C (optimum is 32°C) gain bone marrow fat and lose bone mass, further supporting the interrelationship between adipogenesis and osteogenesis.CPT1) and SCD1 expression, hence leading to lipotoxicity in MSCs from osteonecrotic patients. In line with these preclinical findings are population-based data by Woods and others, who determined bone marrow adiposity of elderly men and women with BMD measurements by magnetic resonance and assessment of the occurrence of prevalent vertebral fractures. Both in men and women, the bone marrow fat percentage positively correlates with prevalent vertebral fracture and femoral neck BMD. Taking an opposite approach, Grahnemo and colleagues studied a RID transgenic mouse model, which is characterized by low visceral adiposity and possibly also low marrow fat. Compared to wild-type mice, both male and female RID mice had increased trabecular BMD and cortical content, as well as greater bone strength. Nevertheless, it is currently unclear whether the improved skeletal health in these mice is explained by low visceral fat or perhaps reduced BMAT. Although many questions remain, these studies together suggest that BMAT, through secretion of FFAs, may affect neighboring bone cells leading to compromised skeletal health.Evidence is accumulating that lipids in the bone marrow microenvironment affect bone cell function. For example, storage of BMAT-derived lipids in osteocytes may lead to their apoptosis, either during osteocyte differentiation or when osteocytes are fully mature and embedded in the bone matrix. Furthermore, saturated free fatty acids (FFA), such as palmitate, cause endoplasmic reticulum stress and apoptosis in human MSCs. Interestingly, Dalla Valle showed that the deleterious effect of saturated FFA was abrogated by converting them into mono-unsaturated FFAs through increased activity of the enzyme stearoyl-Co-A desaturase 1 (SCD1), for example by expression of the Liver X receptor (LXR). This result was supported by a study from the same group looking at patients having non-traumatic osteonecrosis. Among other potential causes, increased bone marrow adiposity may underlie osteonecrosis and it was shown that MSCs from these patients are more susceptible to palmitate, leading to increased adipocyte differentiation. The mechanism proposed to limit the exposure to saturated FFAs as described by Dalla Valle was recapitulated in this study, as shown by dysregulation of ERK (MAPK1/MPAK3) activation and Carnitine Palmitoyltransferase  and the expression of these genes was further elevated following ovariectomy. Of interest, Bisschop showed that BMAT in women varies with specific stages of pregnancy, which further corroborates the importance of the gonadal axis in regulating BMAT.Douni presented 2 different transgenic mouse models of osteoporosis. One model expresses low copy numbers of RANKL and presents with trabecular bone loss only; in contrast, the second model has a high RANKL copy number and displays trabecular bone loss and cortical bone porosity, at least partially due to high osteoclast numbers. Of interest, BMAT is increased up to 100% in these high-copy number mice by only 4 months of age.Rankl expression. PTH treatment in vivo inhibited BM adipogenesis. Hence, this study suggests that PTH signaling may mediate mesenchymal stem cell fate allocation in the bone marrow environment and that BMAT controls bone resorption.The Lanske group presented data indicating a novel role for PTH in marrow adipogenesis. Of interest, PTH levels are high in conditions that are characterized by high BMAT, such as osteoporosis, caloric restriction and chronic kidney disease, suggesting that PTH might stimulate adipogenesis. Contrary to this expectation, mice lacking the PTH/PTHrP receptor (Pth1r) in MSCs had severe loss of trabecular and cortical bone with a concomitant marked increase in BMAT. Culturing bone marrow derived cells from these mice exhibited preferential differentiation into adipocytes. Remarkably, bone resorption was also increased in these mice presumably due to BMAT-derived Using an elegant 3D BMAT culture model composed of silk scaffolds, Fairfield showed that another classical osteocytic factor, Sclerostin (SOST), affects BMAT. Leptin has a well-established function as being an appetite-reducing adipokine, but its effect on bone metabolism remains obscure, despite many efforts focusing on the contribution of systemic and peripheral leptin. Van der Eerden and coworkers added complexity to the current knowledge by providing additional evidence that human osteoblasts produce leptin, and that osteoblast-produced leptin is crucial for osteoblastic differentiation and mineralization. It remains unclear whether leptin produced by neighboring adipocytes contributes to osteogenic differentiation, but it is evident that an autocrine/paracrine role in osteoblasts cannot be ignored. Because PTH, sclerostin and leptin collectively represent crucial players in skeletal homeostasis, it will be informative to examine their roles in the potential cross talk between adipocytes and osteoblast lineage cells.In summary, evidence is accruing that BMAT is a complex tissue in which multiple cell types from distinct developmental lineages control skeletal health through local production of lipids and growth factors. It will be important to determine the temporal and spatial mechanisms that mediate cross-talk of bone cells with BMAT, and how this cross-talk supports skeletal health.BMAT research is an emerging and exciting topic in pre-clinical and clinical research. It has direct implications for many different scientific fields, including bone biology, oncology, metabolism, aging, endocrinology, haematology, and rheumatology, but also for BMAT-related clinical conditions. The future research on BMAT will yield novel fundamental knowledge with huge potential for translation, including how BMAT impacts disease progression and by identifying BMAT biomarkers for improved disease diagnosis and treatment. Such knowledge could open new avenues for personalized medicine, as well as population-level screening and management.


Glucocorticoids (GCs) are steroid hormones, naturally produced by activation of the hypothalamic-pituitary-adrenal (HPA) axis, that mediate the immune and metabolic systems. Synthetic GCs are used to treat a number of inflammatory conditions and diseases including lupus and rheumatoid arthritis. Generally, chronic or high dose GC administration is associated with side effects such as steroid-induced skeletal muscle loss, visceral adiposity, and diabetes development. Patients who are taking exogenous GCs could also be more susceptible to poor food choices, but the effect that increasing fat consumption in combination with elevated exogenous GCs has only recently been investigated. Overall, these studies show that the damaging metabolic effects initiated through exogenous GC treatment are significantly amplified when combined with a high fat diet (HFD). Rodent studies of a HFD and elevated GCs demonstrate more glucose intolerance, hyperinsulinemia, visceral adiposity, and skeletal muscle lipid deposition when compared to rodents subjected to either treatment on its own. Exercise has recently been shown to be a viable therapeutic option for GC-treated, high-fat fed rodents, with the potential mechanisms still being examined. Clinically, these mechanistic studies underscore the importance of a low fat diet and increased physical activity levels when individuals are given a course of GC treatment. Glucocorticoids (GCs) are a classification of steroid hormones, naturally produced by activation of the hypothalamic-pituitary-adrenal (HPA) axis, that are responsible for mediating both the immune system and energy metabolism. Over the past six decades, synthetic GCs have been established as an integral component of hematological cancer therapy  and are This paper will summarize the available information regarding the metabolic implications associated with the collective effects of elevations in GCs and a HFD . This information is critically important and clinically relevant as the number of patients taking exogenous GCs is rising and underscores the importance of a low fat diet when individuals are given a course of GC treatment.Several cardiometabolic diseases  are associated with elevations in GC concentrations . The eleDue to their systemic catabolic actions, GCs increase hepatic glucose production , skeletaGCs act on the central nervous system to impact feeding behavior and physical activity patterns . In rodeInsulin resistance, which is an impaired response of insulin-sensitive tissues to insulin signalling, is a characteristic feature of T2DM and plays a key role in the pathogenesis of the disease ,35. SystCushing’s disease patients are characterized by a redistribution of body fat from peripheral subcutaneous depots, to more central abdominal regions . This ovGCs affect several integral proteins responsible for insulin-stimulated glucose uptake. Treatment of male rats with dexamethasone (Dex), a GR agonist, causes a reduction in insulin receptor (IR) phosphorylation within skeletal muscle and subsequent inhibition of Akt phosphorylation/activity after insulin administration . This deThe liver is a major organ responsible for regulating glucose and lipid homeostasis. In the fasted state, the liver’s glucose production through gluconeogenesis (GNG) and glycogenolysis (GGL) helps maintain euglycaemia. In the fed state, increased glucose uptake into the liver and the reduction in glucose production are critical components to post-prandial glucose control. With increased plasma glucose concentration, insulin is responsible for suppressing endogenous glucose production , while GGC-induced hepatic insulin resistance results in impaired suppression of hepatic glucose production by insulin . GeneralIt is clearly established that elevations in GCs, whether in Cushing’s disease patients or through exogenous corticosteroid therapy, cause excess adiposity . This fiAs mentioned above, 11β-HSD1, which is predominately expressed within the liver, brain, skeletal muscle, and adipose tissue, amplifies the amount of active GCs in a given tissue, potentially increasing the exposure to increased GC activity . IncreasThe catabolic activity of GCs causes the mobilization of substrates from peripheral sources such as the skeletal muscle, liver, and adipose tissue. GCs are also capable of acting on the brain by modulating behaviour, autonomic, and sympathetic responses in addition to augmenting learning and memory . The conTwo elegant rodent studies examined the effect of prior metabolic stress (restraint or cold stress) on the preference for “comfort foods” and the subsequent response of the HPA axis. Both studies found that “comfort” foods were preferred to standard chow, and the provision of these “comfort” foods reduced the degree of the stressor-induced sympathetic responses and lowered the basal corticotropin-releasing factor/hormone (CRF) levels within the hypothalamus ,79. CushWith the number of people currently taking synthetic GCs on the rise , it is iIn one key study, Gounarides et al.  examinedGenerally, the above HFD/GC overexposure models demonstrate a consistent and rapid increase in both visceral adiposity and ectopic lipid deposition . It is possible that since elevations in IMCL are known to occur within 2–3 days of HFD , and as Another methodology utilized to induce HPA activation is the chronic stress model, such as chronic social defeat stress (CSDS), restraint stress, or cold stress. Generally, when this form of GC elevation is combined with a HFD, the results are surprisingly contradictory to what is observed when Dex or corticosterone is injected or implanted exogenously. In mice exposed to both DIO and CSDS, the chronic stress actually improved the increased adiposity, body weight, and glucose intolerance observed after DIO . SimilarRegular physical activity  is widely used to control and/or treat several cardiometabolic diseases because of its compensatory and regulatory actions on a variety of organs including muscle, bone, liver, and adipose tissue. Interestingly, exercise is itself a common form of metabolic stress which stimulates the HPA axis  causing Voluntary exercise, generally considered to be aerobic, is well known to improve skeletal muscle insulin-stimulated glucose uptake  and insuRemarkably, very little is known in regard to the effect of regular exercise in rodents or humans consuming a HFD while undergoing exogenous GC treatment. To date, only three studies have investigated the therapeutic potential of exercise, predominantly aerobic exercise, in GC-treated, high-fat fed rodents. Liu et al.  establisDue to their pleiotropic consequences, GCs affect almost every tissue in the body, which increases their possible therapeutic benefits, but also intensifies likely side effects. Synthetic GCs are the predominant form of treatment for numerous inflammatory and immunological disorders, which makes the understanding the effect of diet and nutrition on their action a major clinical concern. Significant relationships exist between exogenous elevations in GC concentrations, peripheral insulin resistance, and diabetes development; an association which becomes magnified with the addition of a HFD. Fortunately, exercise appears to be a viable therapeutic option to offset some of the more severe metabolic side effects by improving overall glucose tolerance, skeletal muscle insulin signaling, insulin secretion, and body composition. Further research is required to fully understand the metabolic consequences of combining elevations in GCs and increased dietary fat in addition to the effect of exercise as a possible countermeasure.


The stability of an arterial thrombus, determined by its structure and ability to resist endogenous fibrinolysis, is a major determinant of the extent of infarction that results from coronary or cerebrovascular thrombosis. There is ample evidence from both laboratory and clinical studies to suggest that in addition to inhibiting platelet aggregation, antithrombotic medications have shear-dependent effects, potentiating thrombus fragility and/or enhancing endogenous fibrinolysis. Such shear-dependent effects, potentiating the fragility of the growing thrombus and/or enhancing endogenous thrombolytic activity, likely contribute to the clinical effectiveness of such medications. It is not clear how much these effects relate to the measured inhibition of platelet aggregation in response to specific agonists. These effects are observable only with techniques that subject the growing thrombus to arterial flow and shear conditions. The effects of antithrombotic medications on thrombus stability and ways of assessing this are reviewed herein, and it is proposed that thrombus stability could become a new target for pharmacological intervention. AntiplaIt is generally accepted that antiplatelet agents exert their antithrombotic effects by inhibiting agonist-induced platelet aggregation. It is for this reason that point-of-care platelet function tests that assess platelet aggregation in response to specific agonists, such as arachidonic acid, adenosine diphosphate and thrombin receptor activating peptide have been developed. However, in stenosed arteries, it is a shear gradient-dependent platelet aggregation mechanism which drives thrombus formation, while soluble agonists have only secondary roles, mainly stabilizing the formed aggregate .Further, some important determinants of thrombus formation, such as thrombin generation, fibrinolytic activity and endothelial dysfunction in patients on dual antiplatelet therapy are not determined by platelet aggregability . For exaThis finding together with the recognition that some patients continue to experience recurrent thrombotic events despite dual antiplatelet medications, has led to the proposal that some patients may benefit from anticoagulant treatment following percutaneous coronary intervention .Amongst patients receiving dual antithrombotic therapy, some patients despite compliance exhibit high on-treatment platelet reactivity  and it was shown that this was predictive of recurrent ischaemic events , 8. HoweThere is however, evidence to suggest that antiplatelet agents may have additional benefits, in addition to inhibition of platelet aggregation, which may impact on thrombus stability.The stability of an arterial thrombus is the major determinant of the severity and extent of distal tissue damage in myocardial infarction and ischaemic stroke . ThrombuIt has been observed that shear-induced platelet aggregation is inversely proportional to shear rate. Shear-induced platelet aggregation occurs when shear-activated platelets aggregate. The intensity of shear rate can regulate both the capture of flowing platelets into the aggregates and the size of those aggregates. Aggregation is less likely to occur at high shear stress sites because hydrodynamic forces carry platelets away with the flow, and aggregation appears to occur predominantly just downstream to this, at location(s) where shear drops but where platelets are able to aggregate via von Willebrand Factor (vWF). Any model involving only the effect of aggregation would inevitably yield to a steady state where all platelets are clumped together in a single aggregate. Hellmuth et al. developed a mathematical kinetic model to better understand the mechanisms of shear-induced platelet aggregation . PreviouSubstantial laboratory and clinical data suggest that current antiplatelet and antithrombotic medications exert some of their important effects by potentiating thrombus instability and susceptibility to fibrinolysis Table . The aimHigh shear rate at the arterial wall results in endothelial expression of vWF which results in platelet adhesion via interaction of platelet glycoprotein Ib-IX-V with vWF, with a supporting role for the P-selectin/P-selectin glycoprotein ligand 1 axis. This is followed by firm platelet adhesion to the endothelium via interaction of platelet aIIbb3 with endothelial avb3 and intercellular adhesion molecule 1. Subsequently, thrombin, the thrombospondin-1/CD36 axis and cyclooxygenase 1 all play a role in subsequent platelet activation and thrombus stabilization .Platelet receptors and ligands involved in initial integrin aIIbb3 activation and reversible platelet aggregation are shown in Fig. Contact-dependent signaling mechanisms are implicated in platelet contraction, irreversible platelet aggregation and stabilization of platelet aggregates. Subsequent activation of platelets is further promoted by degranulation and release of adenosine diphosphate (ADP) and thromboxane. Degranulation also results in release of CyPA, a potent stimulant of platelet activation which also enhances binding of fibrinogen to platelets . ThrombiAlthough the cardioprotective effects of aspirin are well recognized, after more than three decades of research, the mechanism of aspirin’s antithrombotic effect is still not fully understood. The prevailing view is that aspirin impairs platelet aggregation and subsequent thrombus formation via inhibition of platelet thromboxane synthesis.However, experimental evidence indicates a significant mismatch between the potent inhibitory effect of aspirin on platelet aggregation measured in vitro in anticoagulated blood, under static conditions, and the magnitude of the effect measured in vivo, under pathologically-relevant flow conditions. This discrepancy suggests that aspirin’s antithrombotic effect may involve other mechanisms of action, in addition to the inhibition of cyclooxygenase.−1, and loss of antiplatelet effect at high arterial shear rates has also been demonstrated in patients with severe atherosclerotic stenoses [In a perfusion chamber set-up, aspirin significantly reduced thrombus volume and thrombus height in the presence of citrate but no significant effects were observed in native, non-citrated blood –19. Furtstenoses . Perfusistenoses .It was shown that aspirin directly stimulated the activity of endothelial nitric oxide (NO) synthase and increased bioavailability of systemic NO . The addUsing a perfusion chamber to observe the growth and fragmentation of thrombus, it was shown that whilst aspirin or clopidogrel, either alone or in combination, failed to reduce thrombus growth in some individuals; in combination, caused marked destabilization of the formed occlusive thrombus in all subjects . These o2 levels were predictive of cardiovascular events over a 3-year follow-up [These laboratory findings, suggesting a mismatch between aspirin’s anti-aggregatory effects and its effects under high shear conditions in native blood, have also been supported by the findings of some recent clinical studies. Although it was postulated that patients with high on-treatment platelet reactivity (HTPR) despite taking aspirin would have a higher risk of adverse cardiovascular events, this postulate has been challenged. A recent study investigating the association between cardiovascular events and the most common laboratory indices of aspirin’s antithrombotic effects, namely HTPR and residual cyclo-oxygenase (COX)-1 activity, found that neither HTPR nor high residual COX-1 activity was significantly associated with likelihood of cardiovascular events . The larollow-up .Evidence suggests that there may be two distinct phases in the stabilization of a growing thrombus. The rapid first phase involves the tightening of platelet–platelet contacts in the loose platelet aggregate, resulting in a tight platelet core of thrombus with little space between platelets. Platelet activation during thrombus formation is localized to this central core, surrounded by a shell of non-activated platelets. The second, slower phase is linked to thrombin generation and fibrin formation.12 receptor is required for sustained activation of integrin αIIbβ3, irreversible platelet aggregation and thrombus stabilization [12 receptor, was confirmed using an ex vivo perfusion chamber technique. Whilst P2Y12 receptor antagonist treatment variably reduced the rate of thrombus growth, it consistently reduced thrombus stability and induced thrombus fragmentation [12 -null mice, only small unstable thrombi formed which did not reach occlusive size [Adenosine diphosphate plays an important role in the formation of a tightly packed, firm platelet core and thus in the maintenance of thrombus stability . The P2Ylization . The impentation . In an iive size .Electron microscopy revealed that in response to ex vivo ADP stimulation, blood from patients taking clopidogrel formed loosely packed, unstable thrombi, compared to blood from untreated patients, indicating that clopidogrel impaired the formation of the platelet-to-platelet contacts needed for normal thrombus growth and stabilization .12 antagonists have been shown to greatly enhance subsequent disaggregation through destabilisation of platelet–platelet contacts, and it has been proposed that measurement of disaggregation may be superior to measures of peak aggregation as a way of identifying P2Y12 inhibitor non-responsiveness and may allow tailoring of pharmacotherapy [12 inhibitor, disaggregation following specific agonist-induced platelet aggregation was variably but significantly increased [In addition to inhibiting peak platelet aggregation in response to ADP, P2Yotherapy –37. In pncreased .12 receptor inhibition. As described for aspirin, increased synthesis and release of NO from the endothelium affects thrombus stability by weakening the attachment of the thrombus to the vessel wall and by inhibiting clot retraction, leading to enhanced thrombus fragility. Furthermore, thrombus de-stabilisation may be responsible for the benefits of clopidogrel in the setting of therapeutic fibrinolysis. Addition of clopidogrel to aspirin and fibrinolytic therapy in patients with ST-segment elevation myocardial infarction was shown to significantly improve the patency rate of the infarct-related artery and reduced the frequency of ischaemic complications compared to aspirin and fibrinolysis alone [12 inhibition with ticagrelor or cangrelor. The P2Y12-dependent thrombus stabilization was accompanied by increased fibrin binding, and this P2Y12 function was restricted to high shear flow conditions [12 may be critical for early platelet thrombus stabilization [12 antagonism disrupts the stability of newly formed platelet aggregates, promoting disaggregation [Clopidogrel was shown to improve endothelial function and systemic NO bioavailability in patients with coronary artery disease . In contis alone , 41. In nditions . Freshlylization . An in vregation .preventing platelet aggregation, GPI can also promote instability of pre-formed thrombi by enhancing platelet disaggregation, reducing clot retraction, and reducing soluble CD40 ligand release from platelets [In addition to the well-recognised effects of glycoprotein IIb/IIIa inhibitors (GPI) in latelets . Abciximlatelets , leadinglatelets .Observation of the three dimensional structure of platelet thrombi formed on a collagen surface, showed that perfusion of blood containing the glycoprotein inhibitors abciximab, eptifibatide, or tirofiban over the formed thrombus resulted in thrombus dissolution, whereas this was not seen with control blood , 47. SucObservations from capillary perfusion systems and platelet aggregometry studies showed that abciximab and eptifibatide readily dispersed freshly-formed platelet aggregates, an effect mediated through dissociation of fibrinogen from the platelet surface . Others Thrombin, the most potent agonist of platelet aggregation, determines the formation of fibrin and physical characteristics, inhibits fibrinolysis and plays a central role in thrombus growth and stability . DespiteReal-time visualization of thrombus formation in experimental studies has shown that reducing the propagation of the thrombus and reducing its stability may be a novel way of reducing thrombosis. Not surprisingly, a number of novel antithrombotic agents have been developed and hold promise in reducing thrombus stability, discussed in a recent review in detail . These cStudies using animal models of thrombosis revealed that the contact activation plays an important role in thrombus formation while it has little or no role in haemostasis.Under pathologically-relevant shear conditions, factor XI has been shown to enhance coagulation, adhesion and aggregation of platelets and thrombus growth on collagen or tissue factor coated surfaces. Factor XI also protected the clot/thrombus against lysis once it was formed –59. In cInhibition of activated Factor XII (FXIIa) provides thromboprotection by reducing clot firmness . As reveThere are currently no inhibitors in routine clinical use targeting the primary platelet receptors, glycoprotein Ibα or glycoprotein VI, or their ligands (vWF/collagen) that initiate platelet adhesion and activation and become increasingly important as the shear rate increases.Inhibition of glycoprotein VI-dependent pathways by interfering in vascular collagen sites could reduce thrombosis in the setting of atherosclerotic plaque rupture, such as in myocardial infarction. Revacept, a soluble dimeric glycoprotein VI-Fc fusion protein has been shown to reduce platelet adhesion by blocking vascular collagen in plaques or erosion and to be safe in preclinical studies. A phase I study in humans showed that Revacept dose-dependently inhibited collagen-induced platelet aggregation without a significant effect on bleeding time. In contrast, ADP- or thrombin receptor activating peptide-dependent platelet aggregation remained unaltered .Antagonists of the platelet integrin αIIbβ3 are potent anti-thrombotic drugs, but also have the life-threatening adverse effect of bleeding. Integrins transmit signals bidirectionally and outside-in signalling greatly potentiates thrombosis. An inhibitor of Gα13-integrin interaction selectively abolishes outside-in signalling, leading to suppression of thrombosis without affecting bleeding time .Platelet degranulation results in release of CyPA, a potent stimulant of platelet activation which also enhances binding of fibrinogen to platelets. Inhibition of extracellular CyPA by specific inhibitors, such as MM284 or specific antibody-based antagonists, may modulate thrombus propagation without affecting the haemostasis .Whilst the generally accepted view is that antiplatelet agents exert their antithrombotic effects by inhibiting platelet aggregation, there is ample data from both laboratory and clinical studies to suggest that in addition to inhibiting platelet aggregation, antithrombotic medications in current use increase thrombus fragility and/or enhance endogenous fibrinolysis. Such interference with the mechanisms that normally impart stability to an arterial thrombus and enable it to resist high shear rates, likely contributes to the therapeutic effect of antithrombotic medications. It is not clear how much these effects relate to the measured inhibition of platelet aggregation in response to specific agonists. Most tests of platelet reactivity in clinical use are performed on anticoagulated blood under static conditions or at flow rates that are too low to be pathologically relevant, and therefore cannot assess thrombus stability. This is at least in part why these pharmacological effects of such medications have been relatively overlooked, in comparison to the effects on platelet inhibition, which have been extensively studied. The assessment of the impact of pharmacotherapies on thrombus stability necessitates that the in vitro thrombus be subjected to pathologically-relevant flow and shear conditions. There is now a need for such clinically applicable testing of thrombus stability in individual patients to assess the impact of different antithrombotic medications. Further assessment of these effects may serve to identify new antithrombotic agents which could target thrombus architecture and stability, by affecting platelet packing density and the density of the fibrin meshwork. Already some novel antithrombotic strategies that reduce thrombosis in experimental conditions appear to also reduce thrombus stability. Such targeted pharmacotherapy could reduce lasting thrombotic occlusion.In conclusion, there is substantial evidence from in vitro and in vivo studies that many antithrombotic medications have shear-dependent effects, potentiating the fragility of the growing thrombus and/or enhancing endogenous thrombolytic activity, and this likely contributes to their clinical effects. The effects of medications on thrombus stability should be further assessed in clinical settings and could become a new pharmacological target.


Picoides arcticus), a focal species representative of deadwood and old-growth biodiversity in eastern Canada. Forest attributes were simulated using a forest landscape model, LANDIS-II, and were used to infer future landscape suitability to BBWO under three anthropogenic climate forcing scenarios , compared to the historical baseline. We found climate change is likely to be detrimental for BBWO, with up to 92% decline in potential productivity under the worst-case climate forcing scenario (RCP 8.5). However, large declines were also projected under baseline climate, underlining the importance of harvest in determining future BBWO productivity. Present-day harvesting practices were the single most important cause of declining areas of old-growth coniferous forest, and hence appeared as the single most important driver of future BBWO productivity, regardless of the climate scenario. Climate-induced increases in fire activity would further promote young, deciduous stands at the expense of old-growth coniferous stands. This suggests that the biodiversity associated with deadwood and old-growth boreal forests may be greatly altered by the cumulative impacts of natural and anthropogenic disturbances under a changing climate. Management adaptations, including reduced harvesting levels and strategies to promote coniferous species content, may help mitigate these cumulative impacts.Many studies project future bird ranges by relying on correlative species distribution models. Such models do not usually represent important processes explicitly related to climate change and harvesting, which limits their potential for predicting and understanding the future of boreal bird assemblages at the landscape scale. In this study, we attempted to assess the cumulative and specific impacts of both harvesting and climate-induced changes on wildfires and stand-level processes  in the boreal forest of eastern Canada. The projected changes in these landscape- and stand-scale processes (referred to as “drivers of change”) were then assessed for their impacts on future habitats and potential productivity of black-backed woodpecker (BBWO;  Climate change is expected to have a strong impact on global biodiversity , includiMany boreal bird species rely on specific vegetation characteristics for different life history traits  that may be associated with different habitat types. Changes in boreal forest properties are thus likely to greatly affect habitat availability, triggering potential shifts in species demography and population persistence , and thuIn addition to climate change, several studies have already pointed out that anthropogenic activities such as forestry and the extraction of mineral and energy resources, have a very significant impact on boreal bird assemblages, notably by modifying forest vegetation composition –23. AlsoIn addition to assessing cumulative impacts, disentangling and assessing the relative contributions of stand- and landscape-scale drivers of changes in vegetation on bird habitat are essential to understand how climate change and harvesting will influence the future of boreal bird assemblages. Recent analyses  have sugMost studies projecting future ranges of bird species rely on correlative species distribution models based mainly on projections of where climate conditions within the current species ranges are likely to occur in the future (see ). This aPicoides arcticus) is found in conifer-dominated over-mature and old-growth forests  from the five replicates of the simulations used to assess the cumulative impacts for each climate scenario.2), which is an estimate of the variance of the dependent variable that can be explained by the driver of change. In this case, the dependent variable was total BBWO potential productivity for the entire study area. Following a three-way factorial ANOVA, where each driver of change  was considered as a factor, we calculated ω2 for each driver of change, at each time step, as:effect is the sum of squares related to the driver of change (the effect), dfeffect is the degree of freedom of the effect, MSerror is the mean square of the error, and SStot is the total sum of squares. ANOVA and ω2 calculations were performed separately for each RCP scenario.The relative importance of each driver of change on BBWO habitat was assessed using omega-squared values (ωt) and forcing scenario. Reduced model testing for impacts of changes in fire and in stand-scale drivers used simulations where fire regime and SEP / maxANPP / maxAGB parameters, respectively, were calibrated for the baseline climate. To assess the quantitative impacts of harvesting, the reduced model used simulations that simply omitted harvesting while controlling for all other factors.In addition to the proportion of variance explained, we also sought to estimate the quantitative impact of each driver of change on BBWO potential productivity, while controlling for all other factors . To do sWe also tested the impacts of each driver of change on each tree species. Percentage differences in simulated AGB (ΔB) between simulations run under the full model and those run under each reduced model were calculated at each time step for each species. These analyses are similar to those conducted by Boulanger et al. . All preTotal AGB was projected to decrease slightly over time in the study area under the baseline climate scenario . Higher BBWO productivity was projected in the early part of the 21st century with projected climate warming (compared to the baseline scenario) until ca. 2020, becoming lower thereafter , the total potential productivity of BBWO was estimated to be ca. 54–58 fledglings/100 kmscenario , althougereafter . By 21002/yr in 2010 to ca. 25–30 by 2020, before declining drastically to ≤6 fledglings/100 km2/yr in 2100 . However, shifts were projected by ca. 2050 under increasing anthropogenic climate forcing, where recently burned old coniferous stands were projected to become more productive than old coniferous unburned stands, with the differences being amplified under the more severe climate forcing scenarios .Harvesting was projected to reduce BBWO potential productivity throughout the simulation period , and it Few studies have projected the cumulative impacts of climate change and harvesting at both the stand and landscape levels on bird habitats using a spatially explicit forest landscape models . Ou2/yr) may not be high enough to support sustainable populations under any realistic anthropogenic forcing scenario. Based on historical forest age-structure, BBWO productivity was estimated to be ca. 75 fledglings/100 km2/yr in a 2,500-km2 boreal landscape in central Québec [sensu [Our simulations suggest that the cumulative impacts of forest harvesting and climate change on the forest ecosystem will cause major reductions in the availability of future BBWO habitat, with the potential productivity of this focal species being more severely reduced under stronger anthropogenic climate forcing. Among other impacts, climate change would impose changes in the relative importance of available habitat types for BBWO potential productivity. Under the baseline climate scenario, populations were largely maintained by the productivity of old coniferous stands. With climate warming, however, recently burned old coniferous forests would likely become more important for supporting BBWO. Conversely, increased reliance on burned forests under a warmer climate would not completely compensate for decreases in productivity due to the loss of old-growth coniferous forest, notably to harvesting. As a consequence, the projected potential productivity of BBWO by 2100 (reduced to below <10 fledglings/100 kml Québec . Althougc [sensu ).-1 for most forest management units) when compared with those reported by Boulanger et al. [per se. By targeting old-growth stands, high business-as-usual logging rates would likely contribute to the decline of suitable late-successional coniferous stands, while maintaining some important deciduous species, including trembling aspen, white birch and red maple, regardless of the climate scenarios. Boucher et al. [Nevertheless, our results show that important declines in BBWO potential productivity would likely occur in this area even under present-day climate, underlining the importance of non climatically-driven changes. Harvesting was found to be the most important driver of changes in BBWO potential productivity, regardless of the anthropogenic forcing scenario. In this context, harvesting would interact synergistically with climate-induced changes in forest landscapes to further shrink high-quality BBWO habitats over the long term. This striking result was contrary to our expectations as recent analyses  have indr et al.  when ther et al. . Moreover et al.  have shor et al. –89), notr et al. . Our 100Despite the major impacts of harvesting, climate-driven changes in BBWO productivity will be very significant and mostly linked to changes in the fire regime. Fire seasons in the study area have been projected to lengthen, leading to more frequent and severe fire-conducive weather . BBWO isOur simulations showed that climate-induced changes in stand-scale processes  are likely to have little impact on future BBWO potential productivity. Previous simulations performed on southern Canadian boreal forests , 63 haveOf greatest importance, our results suggest that maintaining current harvesting strategies could exacerbate the negative impacts of climate change on BBWO habitats and potential productivity. Even without climate forcing, however, business-as-usual harvesting strategies could lead to marked decreases in BBWO productivity. Similar results were also found by Mahon et al.  for nort2 fertilization on tree growth and stand succession. The potential interaction of higher CO2 with significantly longer growing seasons adds uncertainty to the predictions of reduced forest growth, particularly in regions where soil moisture and nutrients are non-limiting . Als. Als2 feg  were nosensu [Although our simulations attempt to integrate habitat and demographic information, we did not present landscape-based population viability models (sensu ), mostlysensu , 99. In sensu . Likewissensu , 100), asensu ). Furthesensu , 103, alsensu .Our study provides landscape-scale analyses of climate change on the habitat of a focal bird species in Canada’s eastern boreal forest. Since BBWO is considered an indicator species for recent deadwood and old-growth biodiversity in the boreal forest , 45, 46,The challenge we are confronting is how to balance the management of multiple forest values and ecosystem services while reducing uncertainty about the future conditions within which the forest is going to evolve, and projecting future habitats for species like the BBWO is part of that process. Finding convergence and implementing it in strategic forest planning is key to achieving sustainability. In that context, the generalist quality of a forest simulator such as LANDIS-II makes it a useful tool for integrating ecological processes and testing management strategies with multiple simultaneous objectives.S1 Appendix(PDF)Click here for additional data file.S2 Appendix(PDF)Click here for additional data file.S3 Appendix(PDF)Click here for additional data file.S4 Appendix(PDF)Click here for additional data file.S5 Appendix(PDF)Click here for additional data file.


Background: Prostate cancer (PCa) is a critical health burden, impacting the morbidity and mortality of millions of men around the world. Most of the patients with PCa have their disease at first sensitive to androgen deprivation treatments, but later they develop resistance to therapy and eventually die of metastatic castration-resistant prostate cancer (CRPC). Although the newly developed anti-androgen therapies are effectively alleviating symptoms and prolonging lives of patients, there are still no curable treatments for CRPC. Recently, statistical studies have shown that the chronic use of aspirin might be significantly associated with better outcomes in PCa patients. Through this review, we aim to identify the different proposed molecular mechanisms relating aspirin to the pathobiology of PCa neoplasms, with a major focus on basic research done in this context.Methods: Articles were retrieved via online database searching of PubMed and MEDLINE between 1946 and September 2016. Keywords and combinations related to PCa and aspirin were used to perform the search. Abstracts of the articles were studied by two independent reviewers and then data extraction was performed on the relevant articles that met our review objectives.Results: Aspirin, a non-steroidal anti-inflammatory drug (NSAID), affects the proliferation, apoptosis, resistance and metastasis of PCa cell lines, through both COX-dependent and COX-independent mechanisms. It also lowers levels of the PCa diagnostic marker prostate specific antigen (PSA), suggesting that clinicians need to at least be aware if their patients are using Aspirin chronically.Conclusion: This review strongly warrants further consideration of the signaling cascades activated by aspirin, which may lead to new knowledge that might be applied to improve diagnosis, prognosis and treatment of PCa. Prostate cancer (PCa) is the most prevalent solid tumor in men from industrialized nations and is the second largest cancer-related killer  in preventing colorectal cancer has been well-established  in aspirin users  pathway and the prostaglandins (PGs) synthase pathway, thus suppressing PG synthesis and inflammation  do bring systemic concentrations high enough to inhibit both COX1 and COX2. However, in nucleated cells, due to de novo synthesis, inhibition can only be prolonged with repeated daily dosing  mRNA and protein levels in dose-and time-dependent manners  secretion—one of the crucial molecules involved in cancer metastasis—from the highly invasive human PC3 PCa cells . When combined with statins in treatment, aspirin was shown to decrease proliferation of LNCaP cells with a reduction in cyclin D1 levels—which modulates cell cycle progression -induced apoptosis in both androgen-dependent LNCaP cells and other LNCaP derived cells , which represent CRPC, through decreased survivin protein—a versatile modulator of cell division and apoptosis in cancer Altieri, —expressiAnd finally, researchers have also evaluated the effect of new nitric oxide (NO) donating NSAIDs, including NO-aspirin and NO-ibuprofen, on LNCaP and PC3 PCa cell lines. They found these drugs to be potent inhibitors of proliferation and inducers of apoptosis via enhanced caspase-3 expression  pathway of arachidonic acid metabolism in the progression of PCa. Yang et al. showed that LO products, including 12-HETE, were significantly higher in malignant prostate tissue than non-malignant tissue. The role of an NSAID like aspirin in this process is unclear  receptor superfamily and tumor suppressor highly expressed in normal prostate epithelial cells  pathway  expression -70 expression in these cells  at AUB-FM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer JL and handling Editor declared their shared affiliation, and the handling Editor states that the process nevertheless met the standards of a fair and objective review.


Blunt cerebrovascular injury (BCVI) to the carotid artery is a relatively rare injury that is difficult to identify even with imaging. Any symptoms or neurological deficits following blunt neck injury mandate evaluation and consideration of BCVI. In an effort to highlight this issue, we report the case of a 31-year-old male patient who presented with left-sided weakness consistent with transient ischemic attack (TIA) and concussion. The patient's symptoms occurred within 24 hours of a blunt neck injury sustained by a knee strike during a basketball game. An initial computerized tomography (CT) scan of the brain was normal; a CT angiogram (CTA) of the neck and carotids did not reveal obstruction, dissection, stenosis, or abnormalities of the carotid or vertebral vessels and the patient was subsequently discharged. A magnetic resonance imaging (MRI) of the brain obtained four days after the initial injury demonstrated an acute infarct in the right middle cerebral artery (MCA) territory. Thus, despite initial negative imaging, neurological deficits must be aggressively pursued in order to prevent stroke in BCVI cases.  Blunt cerebrovascular injury (BCVI) is relatively rare, with an incidence rate of 0.39–1.11% . BCVI paA 31-year-old male with no significant history presented to the emergency department (ED) with left arm and leg weakness accompanied by headache and right-sided neck pain. The day prior while playing basketball, he sustained a blow to the right lateral neck during a collision with the knee of another player. That night, the patient had left arm and leg weakness accompanied by a facial droop, the latter resolving prior to presentation to the ED. In the ED, the patient had localized tenderness over the paracervical muscles and residual left arm and leg weakness. He had no carotid bruit, and the remainder of his physical exam was unremarkable. A brain computerized tomography (CT) scan without contrast  and CT aFour days after the injury occurred, the patient presented with persistent dizziness, right-sided headache, and left-sided weakness. During the physical exam a left-sided pronator drift was noted. Magnetic resonance imaging (MRI) of the brain demonstrated an acute ischemic infarct in the right frontoparietal lobe, superior aspect of posterior right temporal lobe, and posterior aspect of the right insular cortex with a 4 mm right-to-left midline shift . MRI of Blunt trauma to the neck with associated BCVI can have devastating complications. Mechanisms in BCVI are thought to include cervical hyperextension or hyperflexion, internal carotid artery stretching over vertebral bodies one and two, direct cervical trauma, intraoral trauma, and basilar skull fracture involving the carotid canal , 5. ThesStroke caused by BCVI occurs within the first 24 hours 25–50% of the time [Imaging modalities to diagnose BCVI include Duplex ultrasound, CTA, MRI, magnetic resonance angiography (MRA), and digital subtractive angiography (DSA). Thorough evaluation for BCVI should be performed in the presence of a clinical examination consistent with stroke, evidence of neck trauma, such as ecchymosis or bruits, and radiographic demonstration of neck injury, such as cervical spine fracture. The Denver Screening Criteria (DSC) was created from DSA studies to categorize the extent of arterial vessel wall injury in BCVI, defined as injury to the carotid or vertebral arteries caused by blunt force trauma . CerebroGenerally, DSA is considered the “gold standard” for BCVI detection; however it is an invasive procedure with inherent risks . AlternaIn the case of our patient, there was no radiologic evidence of cerebral infarction until four days after injury when he presented with a stroke. CTA of the carotid arteries both during initial and follow-up scans were normal. Considering the presenting symptoms and negative CTA, MRI of the brain and cerebral vessels, echocardiogram, and observation would have been an appropriate approach to prompt further diagnostic testing with DSA , 8, 10. To prevent thrombosis, embolization, and cerebral intracranial vessel clot propagation, the current initial recommendation for the management of BCVI is antithrombotic therapy . AntiplaMaking the diagnosis of cerebral ischemia caused by BCVI requires a high index of suspicion. In patients with neurological deficits, continued work-up is necessary. Even in the presence of negative CT and CTA imaging, MRI of the brain and cerebral vessels should be considered when symptoms persist. Patients with a history or presentation consistent with TIA should be admitted and thoroughly evaluated to ensure timely diagnosis and treatment.


Novel insights into the pathophysiology of schizophrenia are needed to move the field forward by providing the conceptual framework to facilitate development of new treatment strategies. It is well established that glutamatergic systems are disrupted in schizophrenia, which are intimately linked to metabolic function. While there are many promising new directions, accumulating evidence suggests that bioenergetic function is impaired in the brain in schizophrenia. There are multiple mechanisms in the brain to meet neuronal energy demands, including glycolysis, lactate uptake, and oxidative phosphorylation. In normal brain, neurons and astrocytes are coupled through the astrocyte-neuron lactate shuttle, where astrocytes metabolize glucose to lactate and pyruvate, primary energy substrates that are transported to neurons via monocarboxylate transporters (MCTs). Lactate generated by glycolysis in glial cells constitutively supports synaptic transmission even under conditions in which a sufficient supply of glucose and intracellular adenosine triphosphate (ATP) are present. Interestingly, working memory and other cognitive domains are dependent on the shuttling of lactate from astrocytes to neurons. This process highlights the bioenergetic coupling between astrocytes and neurons that develops as the brain matures, forming a critical biological process in the mature adult brain. We assessed elements of these systems in postmortem brain, testing the hypothesis that there are cell-subtype defects in bioenergetics function in the frontal cortex in schizophrenia.Well-validated assays were used to assess the activity of three glycolytic enzymes in postmortem dorsolateral prefrontal cortex (DLPFC) samples (n=16/group): lactate dehydrogenase (LDH), hexokinase (HXK), and phosphofructokinase (PFK). Each sample was assayed with and without a specific inhibitor (in duplicate) and normalized to protein loaded into the assay. We also probed for differences in protein expression using western blot analysis. Western blot analyses were run in duplicate using the following antibodies optimized for postmortem brain: MCT1, LDH, LDHA, LDHB, HXK1, glucose transporter 3 (GLUT3). We performed real time quantitative polymerase chain reaction (RT-qPCR) using TaqMan PCR assays  in duplicate on cDNA samples in 96-well optical plates on a Stratagene MX3000P . We also coupled laser capture microdissection (LCM) with RT-qPCR from superficial and deep layers of DLPFC using the Veritas Microdissection instrument and CapSure Macro LCM caps . Similar studies were performed in haloperidol-decanoate or vehicle (sesame oil) treated rats (intramuscular injection every 3 weeks for 9 months).We found a 24% decrease in PFK1 mRNA expression in the dorsolateral prefrontal cortex in schizophrenia (p=0.039). We also found decreases in HXK  and PFK  activity in the dorsolateral prefrontal cortex. These changes were not present in haloperidol treated rats. At the cell-level, in pyramidal neurons we found an increase in MCT1 mRNA expression , and decreases in HXK1 , PFK1 , GLUT1 , and GLUT3  mRNA expression. We found increases in MCT1  and GLUT3 , but not HXK1, PFK1, or GLUT1, mRNA expression in enriched pyramidal neuron samples of antipsychotic treated rats.As the brain develops, bioenergetic organization and the formation of synapses occur simultaneously, creating a fundamentally interdependent system. There is accumulating evidence of implicating a number of abnormalities associated with glucose metabolism, the lactate shuttle, and bioenergetic coupling in schizophrenia, suggesting energy storage and usage deficits in the brain. Bioenergetic deficits and genetic risk for synaptic dysfunction in schizophrenia could contribute to the pathophysiology of this illness. In normal brain, glucose enters cells through GLUTs and is processed by glycolytic enzymes resulting in bioenergetic substrates such as pyruvate. Pyruvate can then be converted to lactate and transported between cells or intracellularly by MCTs to be oxidized in the TCA cycle when neuronal energy demand is high. Our findings of decreased glycolytic enzyme and lactate transporter mRNA expression suggests a decrease in the capacity of pyramidal neurons to generate bioenergetic substrates from glucose via glycolytic pathways. Additionally, if neurons were unable to take up adequate amounts of glucose for glycolysis, the intracellular pool of available pyruvate/lactate for transport into mitochondria may be diminished, ultimately impacting energy supply. It is also possible that there is attenuated glycolysis in pyramidal neurons, with a shift towards pathways that boost protection from oxidative stress (pentose phosphate pathway). Other studies also report region and cell-subtype specific changes in the expression of genes encoding proteins involved in metabolism in this illness. Importantly, the above changes were not attributable to antipsychotic treatment. Both synaptic function and meeting of energetic demands are essential for cognition, and failure of either could contribute to the cognitive symptoms seen in schizophrenia. Augmenting affected systems such as glucose utilization pathways could offer a novel approach to restoring cognitive function in schizophrenia. This could include targeting pro-metabolic substrates pharmacologically.