As such, inhibition or activation of chemerin signaling could be beneficial as a therapeutic approach depending on the type of cancer. Additional studies are required to determine if obesity influences cancer initiation or progression through increased adipose tissue production of chemerin and/or altered chemerin processing that leads to changes in chemerin signaling in the tumor microenvironment.Chemerin is widely recognized as an adipokine, with diverse biological roles in cellular differentiation and metabolism, as well as a leukocyte chemoattractant. Research investigating the role of chemerin in the obesity–cancer relationship has provided evidence both for pro- and anti-cancer effects. The tumor-promoting effects of chemerin primarily involve direct effects on migration, invasion, and metastasis as well as growth and proliferation of cancer cells. Chemerin can also promote tumor growth via the recruitment of tumor-supporting mesenchymal stromal cells and stimulation of angiogenesis pathways in endothelial cells. In contrast, the majority of evidence supports that the tumor-suppressing effects of chemerin are immune-mediated and result in a shift from immunosuppressive to immunogenic cell populations within the tumor microenvironment. Systemic chemerin and chemerin produced within the tumor microenvironment may contribute to these effects via signaling through CMKLR1 (chemerin Overweight and obesity rates have increased steadily for several decades and at present are a major global health crisis of epidemic proportions . Recent While the linkage between obesity and cancer risk is an active area of investigation, the underlying biological mechanisms are not well understood. Moreover, many tumors develop in an adipocyte-rich environment. For example, adipocytes are a major cellular component of the mammary fat pad, and recent evidence indicates that these cells have dynamic interactions with cancer cells to modulate tumor growth and metastases ,12. ThusObesity is characterized not only by a generalized expansion of adipose, but also the development of a progressive metabolic and endocrine dysfunction characterized by profound alterations in the production of several factors including lipids, hormones, pro-inflammatory cytokines, and a suite of adipose derived-signaling molecules termed adipokines ,14. AdipChemerin is a multifunctional secreted protein with established roles in energy metabolism, immune function, and fundamental cell processes such as differentiation, proliferation, and chemotaxis ,25. Cons1) and chemerin receptor 2 (chemerin2) as established by the International Union of Basic and Clinical Pharmacology Committee on Receptor Nomenclature . . chemerie matter . pRCC ace matter . The resquartile b, provid2) did not have larger tumor sizes but were more often at an advanced clinical stage . While the overweight and obese subjects had higher preoperative serum chemerin  in tumors from patients with neuroblastoma, a pediatric cancer of the peripheral nervous system. Moreover, a significant correlation was found between high expression of chemerin1, chemerin2, or CCRL2 and a decrease in overall survival probability. Exogenous chemerin stimulated MAPK and Akt phosphorylation, increased calcium mobilization and MMP-2 secretion from neuroblastoma SK-N-AS cells, while treatment with the putative chemerin1 inhibitor α-NETA reduced the viability and clonogenicity of these cells. Consistent with the latter, α-NETA impaired tumor growth in vivo in a murine SK-N-AS xenograft model. Taken together, these data provide evidence that chemerin/CMKLR1 signaling promotes neuroblastoma development through direct effects on tumor cells and the tumor microenvironment.At present, investigation of the relevance of chemerin and the cognate receptors to cancers of the nervous system is very limited. Tummler et al.  reported1chemerin or CCRL2 mRNA levels were elevated in grade III and IV  tumors compared with grade II glioma . De. De71]. 2 [chemerin expression in prostate tumor tissue [chemerin was downregulated in prostate cancer as compared to benign prostate tissues, with greater downregulation observed in castration-resistant prostate cancers [1 and chemerin2 expression were not evaluated, CCRL2 mRNA and protein levels were reported to be increased in prostate cancer PC3 cells, and CCRL2 expression increased in prostate cancer tissues versus prostate tissues from patients with benign prostatic hyperplasia [No significant difference in serum chemerin concentration was found between patients with prostate cancer and those with benign prostatic hyperplasia, however, differences were identified between cancer patients with different Gleason scores, a progressive measurement of prostate cancer aggressiveness as determined by tumor cell differentiation . Serum c2 . These lr tissue . Further cancers . While cerplasia . However1, chemerin2, and CCRL2 have also been identified in several cancer types and many of the fundamental biological activities  of chemerin have the potential to affect tumorigenesis and tumor progression. These effects may be elicited through immune-independent mechanisms that directly impact the growth and tumorigenicity of cancer cells and/or immune-dependent effects that influence the composition of the tumor microenvironment.Obesity is a major global health concern that has been linked to the development of many prevalent metabolic disorders such as type 2 diabetes, hyperlipidemia, and cardiovascular disease. There is also an increasing awareness that obesity represents a significant risk factor for the development of several malignancies. While our current understanding of the pathophysiological mechanisms linking obesity to cancer is evolving, growing interest has focused on the role of adipocyte-secreted signaling molecules as key mediators linking these disorders. Among these, circulating levels of the adipokine chemerin are well established to be directly related to adipose tissue mass and have been implicated in several obesity-related metabolic comorbidities. Altered levels of chemerin and the cognate receptors, chemerin1-dependent actions of chemerin. Elucidation of the role of chemerin2 and CCRL2 and the chemerin isoform-selectivity of these receptors in the context of cancer are priority areas for investigation. Moreover, while there has been considerable interest in the relationship of systemic concentrations of adipose-derived chemerin to cancer development and prognosis, comparatively little attention has been applied to the relevance of locally-derived chemerin secreted from cells located in the affected tissue or tumor microenvironment. This may be of particular importance to malignancies such as breast cancer where adipocytes are commonly found in close proximity to tumors and where evidence exists for an influence on tumor development and progression. Finally, most research regarding the impact of adipokines on cancer has focused on a single molecule. It is well known that the relative amounts and spectrum of adipokines is affected by adiposity and adipocyte function. Hence, while challenging, it will be important to apply a more holistic experimental approach to consider the interactions of multiple adipokines and consider synergistic and/or antagonistic effects in different tumor types and at different stages of tumor development.At present, epidemiological studies have introduced the potential utility of this adipokine as a potential biomarker for several malignancies, and clinical and empirical evidence supports both pro- and anti-cancer effects of chemerin. This suggests that the biological actions of chemerin with respect to cancer are highly contextual and dependent upon a number of factors that are important areas of further investigation. A fundamental issue in this regard is the large discrepancy (up to three orders of magnitude; see


Biological complexity of mechanisms of autoimmune hemolytic anemia (AHAI) in chronic lymphocytic leukemia B (CLL) and the relation cause / effect between these two diseases has been extensively researched, but currently is still far from being completely understood.It is known that the immune system has an important role in the pathogenesis of autoimmune diseases but also in the chronic lymphoproliferative malignancies. In this process of autoimmunity associated with immunodeficiency, the CLL neoplastic cells, the non-malignant B cells, T cells, and the cellular microenvironment cells are also involved. CLL pathological lymphocytes change peripheral immune tolerance acting as an antigen presenting cells and / or cells expressing inhibitory cytokines. The two subpopulations of T cells also have an important place: self-reactive T helper cells (TH) and regulatory T cells (Treg). The Fas / Fas ligand - cell death mechanism has a significant role both in maintaining cellular homeostasis, malignant hematopoietic cell expansion and the development of autoimmune disorders, including AIHA.The article reviews the etiopathogenesis of the autoimmune mechanism of AIHA in CLL, and its impact on the prognosis and long – term survival of patients with chronic lymphocytic leukemia B. AIHA is an autoimmune disease in which red blood cells (RBC) are destroyed prematurely due to production of antierythrocyte autoantibodies. The most common form of AIHA is characterized by the presence of “warm”-type autoantibodies, which are immunoglobulin G (IgG) type and react optimally at 37o Celsius, causing extravascular RBC destruction by tissue macrophages . Regarding the incidence of AIHA, no statistical differences was observed concerning the time to cytopenia onset during CLL course , treatment modality , and / or long-term survival  . Autoreactive lymphocytes could be the result of the gene segment rearrangement in the DNA of precursor lymphocytes. In most individuals, the intact cell-death mechanisms could inactivate and/or delete these autoreactive clones, but in people with a certain predisposition, a few of these cells continue to proliferate slowly in peripheral lymphoid organs. In addition, the alteration of mechanisms that prevent the expansion of autoreactive cells can cause several autoimmune manifestations [The biological explanation for the association between AIHA and CLL is complex and not fully understood [12]. In the blood of these patients two types of antibodies were identified: immunoglobulins secreted directly by CLL cells, and polyclonal RBC-reactive autoantibodies, with a different specificity and isotype from the first one . In healthy persons, autoreactive B and T cells  stay dormant, but if they are activated, could be capable to produce autoimmune disease [14]. In the context of pathogenic autoantibody production, the B cell is largely studied, it has the ability to process and present antigen, also to express the costimulatory molecules necessary to stimulate TH cells, in a conventional immune response [14]. The role of B cells in presenting autoantigen has been shown [15] in murine models of autoimmune diseases, such as diabetes [a) The studies have shown that the pathogenic autoantibodies could be produced by the residual nonmalignant B cells [14], and also by activation of costimulatory molecules such as CD80; the antigen presentation is enhanced after meeting with T cells expressing CD40 ligand [15]. Although it is known that CLL cells have reduced role as antigen presenting cells for conventional antigens, they are highly effective in stimulating the proliferation of TH cells specific for Rh protein [18].b) The role of CD5+ CLL B cells in autoantigen presentation is complex and unclear. In vitro, the malignant cells appear to be inefficient like antigen presentation cells (APC). This possibility should not be disregarded, additional reports have shown that autoimmune diseases, including AIHA, are initiated by changes in autoantigen presentation such as the recruitment of new APC types [19].c) Also, frequently involved in producing AIHA is the richest membrane protein in the red blood cells, the anion exchanger known as band 3 (B3). Because CLL cells bind with high avidity to B3 and produce in vitro phagocytosis of this protein, it is thought that the malignant lymphocytic cells present epitopes B3 to self-reactive T cell [21]. Treg cells are a subset of T cells, CD4 + CD25hiFoxP3 + and it have a role in maintaining tolerance, protective role in autoimmune diseases but also to initiate oncogenesis [21].d) On the other hand, studies have shown that both autoreactive T helper cells (TH) and regulatory T cells (Treg) play an important role for induction of AIHA [Some studies showed arguments in favor of T cells participation in the generation of antibodies associated with AIHA and CLL: in patients with idiopathic AIHA - presence of Treg clones specific for Rh epitopes [25]. Moreover, Fas is involved in the TH1 cell cytotoxicity, which is partially due to interaction of FasL expressed by activated cytotoxic cells with Fas expressed by target cells .It was identified an autoimmune/ lymphoproliferative syndrome (ALPS) in patients with inherited mutations of the Fas gene, and an ALPS-like clinical pattern (named autoimmune lymphoproliferative disease - ALD) in those with decreased Fas function, but noFas gene mutation. Was suggested that in the same subject, ALD is due to accumulation of several defects and these defects predispose to development of autoimmune diseases and/ or cancer other than ALPS/ALD . Fludara monotherapy is associated with a 2% risk of developing AIHA after the first administration, the next doses causing a significant increase in risk [24].f) Regarding the etio-pathology of the autoimmune anemia in chronic lymphocytic leukemia B it was observed that the risk of development of AIHA during the evolution of CLL is increased after the administration of some chemotherapeutic agents - alkylating agents, purine analogs and alemtuzumab [In terms of molecular and cytogenetic, the development of AIHA in CLL patients was associated with a specific configuration of B cell receptor (BCR) - HCDR3, unfavorable cytogenetic factors, such as del (17)( p13) and del (11) (q23) and un-mutated genetic status of IgVH (immunoglobulin heavy chain) [Pathogenic mechanism of autoimmune hemolytic anemia associated with chronic lymphocytic leukemia is very vast, not researched enough, and also far from being completely known. The prognosis of patients with advanced stage of disease and immune anemia is better than the prognosis of patients with advanced disease and anemia secondary to bone marrow infiltration. Generally, in terms of prognosis, AIHA did not demonstrate a significantly influence on prognosis and survival of patients with CLL. In the two most frequently systems used to staging chronic lymphocytic leukemia B: Rai and Binet, the presence of anemia included patients in the high-risk group, assessing survival ~ 30 months. None of these systems does not make a clear tie between cytopenia, depending on their immune or non-immune origin - although they present a clear difference in prognosis . We believe it is essential to determine the cause of anemia, because it is the only way we can achieve more accurate risk stratification in patients in therapeutic protocols, and also a more effective management of patients who have autoimmune hemolytic anemia associated with CLL.


Microvascular complications are often associated with slow and progressive damage of various organs. Pericytes are multi-functional mural cells of the microcirculation that control blood flow, vascular permeability and homeostasis. Whereas accumulating evidence suggests that these cells are also implicated in a variety of diseases, pericytes represent promising targets that can be manipulated for therapeutic gain. Here, we review the role of pericytes in angiogenesis, blood-brain barrier (BBB) function, neuroinflammation, tissue fibrosis, axon regeneration failure, and neurodegeneration. In addition, we outline strategies altering pericyte behavior to point out problems and promises for axon regeneration and central nervous system (CNS) repair following injury or disease. Revascularization and vascular normalization of these regions is crucial to ensure adequate delivery of oxygen and nutrients needed to sustain the high metabolic demands of performing daily activities essential for maintaining independent living. Under normal physiological conditions, however, axon growth and regeneration are extremely limited in the adult mammalian CNS  trauma and disease is associated with long-term consequences that impair basic body functions including sensation, cognition, locomotion, vision, bladder and bowel movements, all of which negatively impact the independent quality of life. Axon sprouting, regeneration and via physical contact and paracrine signaling  initiates angiogenesis , that allow binding and transmigration of leukocytes across the blood-brain barrier , and a lack of murine Apoe on proinflammatory cyclophilin A expression  where PDGF-B binding to heparan sulfate proteoglycans is disrupted and PDGFRβF7/F7 mice which have approximately 40% of the pericytes coverage of control littermates, have elucidated the impact that loss of pericytes has on the BBB  and trophic factors, may be an avenue worth exploring  pericyte, also known as type A, significantly reduces fibrotic scar formation and impairs wound closure after SCI  are fibrogenic and participate in scar formation, type-2 (Nestin-GFP+/NG2-DsRed+) pericytes are myogenic and aid skeletal muscle repair  exacerbates retinopathy with increased density of acellular capillaries and formation of microaneurysms  increases in the cerebrospinal fluid (CSF) following pericyte loss  with progressive pericyte loss show abnormalities in cortical depolarization, peak amplitude and response latency  is associated with late-onset AD and carriers of the gene have significantly less pericyte coverage compared to APOE3/2 carriers  protein (Sagare et al., 40/42 (Tachibana et al., 40/42 is substantially less, but a decrease is still observed suggesting that pericytes may use multiple methods of clearing Aβ (Tachibana et al., To now, we have only discussed indirect roles that loss of pericytes and capillary constriction can have in the pathogenesis of AD. Pericytes also have direct actions in clearing Aβ All this information taken together paints pericytes as an integral cell type in the pathogenesis and progression of AD. Due to the multitude of effects that pericytes have in different functional areas of the brain such as the BBB, cerebral blood flow and clearing Aβ, they are becoming an attractive target for potential treatments of AD.After being neglected for many years, pericytes have recently become the focus of an emerging field of research indicating that pericyte dysfunction plays a role in the onset and progression of neurodegenerative diseases as well as tissue fibrosis and lack of motor recovery after SCI (Mizutani et al., SIDEBAR 11.  How many different classes of pericytes really exist through the CNS?2.  What are the gene signatures of injury and disease-associated pericyte populations in the brain and spinal cord?3.  How is pericyte behavior controlled in a context-dependent manner?4.  Provided with the appropriate stimuli, do pericytes promote axon regeneration and CNS repair following injury and disease?FL, JP and AT: conceptualization, visualization and writing. AT: supervision, review and editing.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.


Synapse loss is an early feature shared by many neurodegenerative diseases, and it represents the major correlate of cognitive impairment. Recent studies reveal that microglia and astrocytes play a major role in synapse elimination, contributing to network dysfunction associated with neurodegeneration. Excitatory and inhibitory activity can be affected by glia-mediated synapse loss, resulting in imbalanced synaptic transmission and subsequent synaptic dysfunction. Here, we review the recent literature on the contribution of glia to excitatory/inhibitory imbalance, in the context of the most common neurodegenerative disorders. A better understanding of the mechanisms underlying pathological synapse loss will be instrumental to design targeted therapeutic interventions, taking in account the emerging roles of microglia and astrocytes in synapse remodeling. The prevalence of neurodegenerative disorders has been rapidly increasing over the past decades. These untreatable and often lethal conditions including Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS), affect over 100 million people worldwide  include three major cell subsets: astrocytes, microglia and oligodendrocytes. While the latter are mainly responsible for the formation of myelin and for providing metabolic support to axons  increases dendritic spine elimination in the developing mouse visual cortex, with no effects on synapse formation  and metabotropic (GABABR) GABA receptors. In terms of spatial organization, glutamatergic synapses are located almost exclusively on dendritic spines, whereas GABAergic synapses can be spread along the dendritic shaft, somata, and axon initial segments  and Presenilins 1 and 2 (PSEN1 and PSEN2), which cleave APP to form Aβ species  not only induces synaptotoxicity but also synaptic weakening through prolonged long-term depression (LTD) and impaired LTP  crossed with C1q knockout mice, lack of C1q protected against synaptophysin loss in the hippocampus of aged mice  induced neuronal loss, microgliosis and upregulated C3 as well as intracellular Aβ levels  is the strongest genetic risk factor influencing susceptibility to LOAD and it is associated with increased synapse loss , such as DNAJC6 (auxilin) and SYNJ-1 (synaptojanin 1), in patients with juvenile and early-onset atypical parkinsonism  has excitatory effects on the projections from the striatum to the internal segment of globus pallidus (GP), defined as the direct pathway, acting through D1 receptors (D1Rs). The same neurotransmitter, however, exerts inhibitory effects on the projection from the striatum to the external segment of GP through D2Rs, or indirect pathway  are sporadic, with the remaining 10% due to known mutations in a growing number of disease-associated genes, such as c9orf72, SOD1, FUS and TDP-43 , an antioxidizing enzyme, are associated with ALS.via the release of toxic mediators or by direct phagocytosis of neuronal compartments, as described above. The study of microgliosis in human ALS tissue has mostly been confined to post mortem studies, which tend to show an increase in microglia number . In SOD1 models, GLT-1 levels decrease as disease progresses  are important chaperones that reduce protein misfolding and aid in misfolded protein degradation. A recent study has found that in human ALS spinal cord, rapidly progressing disease was associated with increased HSPB5 and HSPB8 in astrocytes  are released from mitochondria within the degenerating motor nerves, supporting the role of mitochondrial dysfunction in ALS  compared to myelinated (MS-M) and control cases in various regions of the hippocampus, including CA3 and CA1  in the CA1 of the hippocampus and impaired LTP in EAE mice, leading to cognitive impairments mediated by IL-1β driven inflammation (Kim et al., However, other studies have reported synapse reduction occurring independently of demyelination (Jürgens et al., Researchers also found increased, rather than decreased, spine density in the somatosensory cortex of EAE mice, associated with increased VGLUT1 levels and disrupted PV+ interneuron connectivity (Potter et al., The synaptic terminals assessed in the above MS and EAE studies are exclusively pre-synaptic with no distinction of excitatory or inhibitory nature. Loss of inhibitory signaling causes E/I imbalance, which has already been described here in the context of dementias but applies to MS as well. Indeed, GABA levels are reduced in the CSF of patients with MS, indicating decreased inhibition (Manyam et al., Reduction of axosomatic synaptic terminals was recently reported in the cerebellum of MS patients, associated with increased levels of reactive astrocytes and microglia, specifically in the dentate nucleus (Albert et al., Altogether, these findings point toward a consistent alteration in the E/I balance in MS and encourage further investigation to better elucidating the role of glia mediated-synapse loss.via non-Aβ mediated mechanisms. However, whether this synaptic and cognitive rescue was due to attenuating microglial driven inflammation is unclear. Microglial neurotoxic and synaptotoxic cytokine release in prodromal stages of the disease is likely to coincide with complement deposition and aberrant phagocytosis. Complement molecules deposited at synapses have been reported to be work as a powerful “eat me” signal in several distinct neurodegenerative disorders. However, synapse elimination in pathological contexts could also be seen as a beneficial process, at least in the initial stages, aimed at re-establishing the E/I balance. Critical information will be provided by clinical trials currently testing a humanized anti-C1q antibody in neurodegeneration, after its safety was recently proven in both animal models and human cohorts (Lansita et al., Here, we have summarized the contributions of glial cells in some of the most common neurodegenerative diseases, highlighting evidence for their role in synapse remodeling. In disease, glia-mediated synaptic refinement likely represents an attempt to counteract network dysfunction occurring in the early stages of the disease. In this scenario, glia selectively remove excitatory or inhibitory connections in specific brain regions, to compensate for disease-associated changes in synaptic input. On the other hand, intrinsic dysfunction of glia cells, due for instance to genetic mutations, could also play a critical causative role in the pathogenesis of the diseases, acting as a primary trigger for E/I imbalance, by inducing excessive synaptic pruning . It is tGiven that early synapse loss is a common phenotype in many neurodegenerative diseases, it raises the exciting possibility that a greater understanding of glia-mediated synapse loss may lead to a single therapeutic strategy that targets many of the world’s most devastating diseases.CH, MT and RP revised the literature and wrote 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.


Delays in clinical suspicion of this diagnosis were common. In addition, no secondary transmission of Lassa fever to contacts of patients with low-risk exposures occurred, and infection of high-risk contacts was rare. Future public health investigations of such cases should focus on timely recognition of distinctive clinical features, earlier treatment of patients, and targeted public health responses focused on high-risk contacts. Lassa virus is a rodentborne arenavirus responsible for human cases of Lassa fever, a viral hemorrhagic fever, in West Africa and in travelers arriving to non–Lassa-endemic countries from West Africa. We describe a retrospective review performed through literature search of clinical and epidemiologic characteristics of all imported Lassa fever cases worldwide during 1969–2016. Our findings demonstrate that approximately half of imported cases had distinctive clinical features (defined as fever and  Time from patients seeking medical care to clinical suspicion of Lassa fever by clinical providers in their destination country ranged from 1 to 22 days (median 5 days). The time from when patients sought care to patient isolation ranged from 1 to 25 days (median 7 days). We found no reports of Lassa virus PCR testing performed on any patient before 2000; however, 9 of 16 patients (56%) in 2000 and later years had a positive Lassa virus PCR test within 1–2 days of hospital admission. Of the 32 patients for whom information on isolation procedures were described, 24 patients were isolated at some point during their hospitalizations in their destination countries. Of these, 11 (34%) patients were placed in a form of isolation immediately after they sought medical care; 3 patients were transferred to biocontainment units, and the remaining 8 patients were isolated with techniques ranging from standard precautions to a combination of contact, droplet, and airborne precautions. Of the 13 patients who were isolated later in their hospital stay, 2 patients were isolated with contact and airborne precautions, and 11 were subsequently transferred to specialized hospitals with infection control capacity designed for the care of patients with highly infectious diseases. Time to isolation ranged from 3 to 15 days after hospital admission  patients initially received antimalarial medications or antimicrobial drugs because of clinical suspicion of malaria or another infectious disease during their treatment course. In total, intravenous ribavirin was ordered for 7 (30%) patients. Four patients received intravenous ribavirin; 2 received a full course, and the other 2 died during treatment. Three patients had intravenous ribavirin ordered but died before receiving the medication.Contact tracing investigations were either not performed or not described in the literature for 16 (48%) patients. For the remaining 17 (52%) patients, a total of 3,420 contacts were followed; the number of contacts followed per investigation ranged from 3 to 552 (median 173). Eleven contact investigations stratified contacts into high-risk and low-risk contacts, with some further separating high-risk contacts into first-line or second-line contacts  did not demonstrate distinctive clinical features of Lassa fever. As such, providers encountering patients who have a nonspecific febrile illness after travel to West Africa should elicit a travel history and consider Lassa fever early in the differential diagnosis. Suspicion should be especially high for those patients with fever and >1 of the distinctive features we have described. Although most returning travelers from West Africa with Lassa fever in 2000 or later had viremia confirmed through a positive Lassa virus test obtained within 1–2 days of admission, some patients did not have their illness diagnosed until weeks into their illness. Samples of patients with suspected Lassa fever should be obtained as early as possible and tested by Lassa virus PCR at a reference laboratory; most reference laboratories in Europe and elsewhere have demonstrated proficiency in performing Lassa virus molecular diagnostics (The 33 cases of imported Lassa fever that occurred during 1969–2016 posed a similar set of challenges: timely diagnosis of a rare infectious disease not endemic to the patient’s destination country, timely treatment, and prevention of Lassa virus transmission to contacts. Among patients who were not medically evacuated, the median number of days from patient presentation to clinical suspicion of Lassa fever by clinicians in the destination country was 5 days. Several factors might have contributed to this delay in diagnosis. First, patients were seen by providers in countries where Lassa fever is not endemic, requiring consideration of a travel-associated illness infrequently encountered outside of West Africa. Second, in many cases, the patients’ travel to West Africa was not known at the time they initially sought care. Third, the clinical findings of Lassa fever are variable, ranging from nonspecific symptoms, such as fever, nausea, and myalgias in the early phase, to more distinctive features later, including pharyngitis, sore throat, tonsillitis, oropharyngeal ulcers, facial and neck swelling, conjunctival injection, and proteinuria. Hemorrhage is usually seen only in a minority of cases. Although fever and Treatment of Lassa fever comprises effective supportive care and use of intravenous ribavirin. Although timely treatment with intravenous ribavirin depends on successful procurement of the drug, it also rests on early consideration of the diagnosis, and might even be administered before laboratory confirmation of Lassa fever diagnosis in patients with severe illness. The relative minority of case-patients who received intravenous ribavirin in our review highlights the importance of early consideration of Lassa fever in the differential diagnosis for appropriate patients.Infection control was another challenge encountered by medical providers and healthcare systems caring for Lassa fever patients. The lack of appropriate use of isolation or barrier precautions in the 2 instances of secondary transmission speaks to the importance of adhering to standard precautions when caring for all patients, regardless of their diagnosis or presumed infectious status. In addition, the case of secondary transmission to the mortician in Germany illustrates the importance of maintenance of standard precautions during autopsy. Early consideration of Lassa fever as a diagnosis might also enable early institution of isolation and prevention of secondary transmission. Among those case-patients for whom a specific form of isolation was specified, most were admitted to high-security containment facilities or negative-pressure rooms with airborne precautions. Although these forms of isolation can prevent secondary transmission of Lassa virus, simple barrier or contact precautions have also been demonstrated to be safe and are less expensive and labor-intensive (Contact tracing investigations frequently involved hundreds of contacts and a substantial investment of time and labor on the part of public health teams. One investigation noted that “active surveillance of contacts by public health teams was impracticable and required enormous resources, involving over 3,000 communications” (Our review had several limitations. Information on historic cases, particularly those before 1985, was incomplete and limited. In some cases, reports provided scant or no information on the physical examination or laboratory studies of patients upon admission. Reports on contact tracing provided different degrees of detail, and levels of risk assessment were variable between investigations.With the ease and frequency of international travel, Lassa fever will continue to be encountered by healthcare providers in countries where Lassa fever is not endemic. Strict maintenance of standard infection control precautions in healthcare is critical for all patients and will help prevent secondary transmission of Lassa virus. Timely recognition of distinctive clinical features, earlier treatment of patients, and targeted public health responses focused on high-risk contacts will also be important components of future responses to imported cases of Lassa fever.Characteristics of imported Lassa fever cases, 1969–2016.


After the re-introduction of African swine fever virus (ASFV) genotype II isolates into Georgia in 2007, the disease spread from Eastern to Western Europe and then jumped first up to Mongolian borders and later into China in August 2018, spreading out of control and reaching different countries of Southeast Asia in 2019. From the initial incursion, along with domestic pigs, wild boar displayed a high susceptibility to ASFV and disease development. The disease established self-sustaining cycles within the wild boar population, a key fact that helped its spread and that pointed to the wild boar population as a substantial reservoir in Europe and probably also in Asia, which may hinder eradication and serve as the source for further geographic expansion. The present review gathers the most relevant information available regarding infection dynamics, disease pathogenesis and immune response that experimental infections with different ASFV isolates belonging to genotype I and II in wild boar and feral pigs have generated. Knowledge gaps in areas such as disease pathogenesis and immune response highlights the importance of focusing future studies on unravelling the early mechanisms of virus-cell interaction and innate and/or adaptive immune responses, knowledge that will contribute to the development of efficacious treatments/vaccines against ASFV. Sus scrofa) of all breeds and ages, with high lethality often up to 90–100% in naïve animals. There is no treatment or effective vaccine commercially available. The causative agent, African swine fever virus (ASFV), is a large and complex double-stranded DNA arbovirus that is the only member of the Asfarviridae family, genus Asfivirus [Currently, African swine fever (ASF) constitutes the biggest threat faced by the world pork industry in decades. ASF is a devastating haemorrhagic infectious disease which affects domestic and wild suids  has been pointed out as the most important host, while the role of bushpigs (Potamochoerus larvatus) in the transmission of ASFV has not been fully elucidated [Ornithodoros genus, especially Ornithodoros moubata and Ornithodoros erraticus, have been shown to be both reservoirs and transmission vectors of ASFV [Among them, the warthog  in 1957 and 1960, and from there to other European countries, South America and the Caribbean. Except for Sardinia, disease was eradicated from outside Africa in the mid-1990s. A second transcontinental spread of genotype II ASFV from Southeast Africa into Georgia occurred in 2007 . ASF subUnderstanding host–virus interactions and disease dynamics in wild boar by way of experimental infections, not only with genotype II isolates currently circulating in Europe and Asia but also with isolates belonging to other genotypes, is critical for risk assessments and future development of safe and efficacious treatment/vaccines effective in this population. Gathering the most relevant information available and identifying knowledge gaps regarding infection dynamics, disease pathogenesis and immune response, mainly in experimentally infected wild boar, was the aim of the present review.Virulence factors, host–virus interactions and the pathogenesis of most of the ASFV genotypes are still far from being understood. This lack of knowledge hampers targeted research into basic mechanisms of disease protection and vaccine design. So far, most studies have been focused on understanding how ASFV isolates of genotype I and II, the only genotypes that have spread outside Africa to date, affect domestic pigs. Since the genotype II outbreak in Georgia in 2007, several studies have been conducted trying to understand infections with particular isolates from Eastern and Central Europe and their disease dynamics. The biological characterization of such isolates has been carried out in domestic pigs ,24,25,263 HAD50 intramuscularly) and high doses  of genotype II isolates from the Caucasus region (Armenia in 2008 and Chechen Republic in 2009) resulted in acute forms of ASF with 100% lethality within less than 10 days [6 TCID50) with the ASFV Caucasus isolate died or were euthanized between day 8–9 pi. No antibodies were detected in serum samples [In general, wild boar displayed an apparent higher susceptibility to ASFV than domestic pigs in many of the experimental studies. The first oral and intramuscular experimental infections of piglets and adult wild boar with medium . A survivor (1 of 10) recovered completely after an acute disease and was commingled with three sentinel wild boar of the same age class from day 50 to 96 post initial inoculation. The sentinels remained healthy and both virus and antibody negative throughout the experiment, so no transmission occurred from the survivor to in-contact pigs. The survivor was negative for ASFV detection in blood and in different tissues taken at day 96 pi, although it had high antibody levels, indicating that virus exposure had occurred [5 to 106.5 HAU) of twelve adult minipigs, five domestic pigs aged six months and five wild boar, three adults around two years old and two piglets six months old [An ASFV isolate was obtained by animal passage using tissue samples that were DNA positive by PCR. These tissue samples were obtained from a wild boar outbreak with apparently low mortality in North-Eastern Estonia in 2015 . In younoccurred . A virusnths old . Three mnths old . In a seDespite the low mortality rates suggested by some field observations, for example in Estonia ,29, and Some studies have suggested the existence of isolates that displayed an attenuated phenotype, especially in domestic pigs ,26, alonEarly literature also describes preliminary experimental infections in wild boar through inoculation, ingestion and contact using Italian isolates belonging to genotype I see . Wild boIn a second experiment, four young wild boar  were split in two pens, each containing two boar of different sex. In both groups, the male boar received 2 mL of leukocytes culture infected with Nemi strain (genotype I) by intramuscular (group 1) and oral route (group 2) while female boar were kept in close contact with the infected animals. In group 1, the male boar intramuscularly inoculated displayed an increase in temperature from 24 h pi and died at day 11 pi showing less severe typical ASF macroscopic lesions  than observed in animals infected intramuscularly in the first experiment. Regarding the female boar in contact, clinical signs, evidence of viral infection or macroscopic lesions characteristic of ASF were not observed throughout several weeks after the death of the male boar. In group 2, the male boar infected orally developed clinical signs from day 6 pi, being euthanized in a moribund state at day 20 pi, while the female boar in contact developed clinical signs from day 20 pi and was euthanized in a moribund state at day 28 pi. In both animals, macroscopic lesions characteristic of ASF were scarce and mild showing mild alveolar oedema and systemic lymphadenitis . 6 HAU of Sardinian 2008 ASFV isolate (genotype I). Animals displayed respiratory distress and were euthanized between day 5 and 8 pi after reaching the humane endpoint. The peak temperature was detected at day 4 pi (41.7 °C), while the highest clinical scores were observed at day 8 pi. At necropsy pulmonary oedema, haemorrhagic lymph nodes, hepatic congestion, gall bladder wall oedema and haemorrhages were the most common macroscopic lesions [In more recent experimental studies, four wild boar were inoculated intramuscularly with 10 lesions .n = 3) and wild boar tested pestivirus-free (n = 3) were experimentally infected by intramuscular route with a dose of 104 TCID50 of ASFV E75 isolate (genotype I), revealed that only CSFV PI wild boar showed a progressive clinical disease from day 4 pi with external lesions and clinical signs typically described in acute forms of ASF  [An interesting study, in which 7-week-old classical swine fever virus postnatal persistently infected (CSFV PI) wild boar (abdomen) . While Cabdomen) . Sus scrofa) trapped in Florida, USA [7 HAU50 of Lisbon 1960 or DR 1979 respectively, while the rest of animals (four per group) were kept in close contact. Clinical signs  were observed in both groups of inoculated pigs between day 3 and 4 pi. All pigs infected with Lisbon 1960 isolate were either dead or moribund 2 to 6 days after the onset of fever (day 7–8 pi for inoculated pigs and day 14–20 pi for contact pigs), developing an acute form of ASF. All pigs exposed to DR 1979 isolate also died but survived 6 to 13 days after the onset of fever (day 11–16 pi for inoculated pigs and day 19–22 pi for contact pigs), developing a subacute form of ASF. In a previous experiment, only 20% of domestic pigs of a similar age died after infection with DR 1979 isolate [Biological characterization of ASFV genotype I strains from the Iberian Peninsula (highly virulent isolate Lisbon 1960) and the Dominican Republic (moderate virulent isolate DR 1979) were also carried out through intranasal inoculations of feral pigs , severe ascites with red-tinged fluid, perirenal oedema and marked retroperitoneal haemorrhages. The haemadsorption reaction, and the direct and indirect immunofluorescence were used to confirm the presence of ASFV in the blood and selected tissues samples from all infected pigs. ASFV-specific antibody response was only detected in pigs that died from 5 to 13 days after the onset of clinical signs .While control efforts, particularly increased biosecurity and professionalisation of the pig industry, have successfully reduced the incidence of ASF in domestic pigs, the wild boar population represents a substantial reservoir in Europe and probably also in Asia, which will hinder eradication and serve as a source for further geographic expansion . TherefoSus scrofa), they belong to different subspecies. Besides genetic differences, domestic pigs are managed and therefore their diet, reproduction and health status are controlled, whereas free-ranging wild boar are subjected to natural nutritional, climatic and reproductive variations and cycles. Wild boar in nature show intraspecific aggression, carry a mixed pathogen load and suffer periods of stress, which may compromise the function of their immune system. All together, these factors may affect the outcome of ASFV infection in wild boar. Therefore, it is important to study the pathogenetic and immunological mechanisms of ASF specifically in wild boar so that not only biological differences with domestic pigs can be identified but also additional differences between experimental and natural ASFV infection in wild boar can be assessed. These data can contribute to epidemiological studies, modelling and design of control strategies such as vaccine development and deployment. The fact that information about the presentation of ASF in wild boar was scarce, and derived only from limited experimental studies, led to early assumptions that it was unlikely that Caucasian isolates would become endemic in European wild boar populations without a significant change in virulence [Due to the close taxonomic relationship between wild boar and domestic pigs it could be assumed that ASFV infection in wild boar has a similar course as in domestic pigs, and furthermore, that an ASF vaccine developed for domestic pigs can be applied to vaccinate wild boar with similar results. However, even though both domestic pigs and European wild boar are of the same species (irulence . The evoIn most of the studies included in the present review, clinical evaluations were carried out by way of equivalent clinical scoring systems, which allowed to set up accurately the evolution and duration of clinical course of disease. In addition, viraemia levels and spread mechanisms through different organic fluids and routes of excretion were determined for swabs and blood samples by equivalent molecular detection techniques. Also, virus burdens in target tissues taken once the animals reached the humane endpoint were precisely evaluated. However, the published studies are more limited on precise, systematic and semi-quantitative evaluations of macroscopic and/or histopathologic lesions, which may establish differences among individual animals. In addition, there are few comparative evaluations between pig and wild boar describing the characteristics of the disease induced by experimental infection with ASFV.Furthermore, apart from ASFV-specific antibody responses, other innate or adaptive immunological parameters that may contribute to memory responses, key for vaccine design, have not been extensively assessed in wild boar. As in domestic pigs, no correlates of protection in wild boar are defined for ASFV infection, which can only be informed by a deeper knowledge of the host–virus interaction. Thus, experimental studies of ASFV in domestic pigs and wild boar require approaches that should be assessed not only by virologists, molecular biologists and immunologists, but also by pathologists. Therefore, along with standard protocols to evaluate virological parameters and immunological responses, scientists involved in ASFV studies would benefit from applying standard pathological evaluation protocols for adequate individual, intergroup and inter-experiment comparison. In this sense, standardized scoring systems to perform macroscopic and histopathological assessments of ASFV-inoculated pigs have been proposed . Such evAlthough pathogenetic mechanisms induced by high and moderate virulence ASFV isolates of genotype I have been widely studied since the disease first appeared in the Iberian Peninsula in the 1950–60s ,48, less


Although further investigation into these observations is needed to clarify OSC function in ovary physiology, clinical investigators and researchers studying female infertility are presently focusing on OSCs as a novel opportunity to restore ovarian reserve in both young women undergoing early ovarian failure and cancer survivors experiencing iatrogenic menopause.Recent studies support the existence of oogonial stem cells (OSCs) in the ovarian cortex of different mammals, including women.These cells are characterized by small size, membrane expression of DEAD(Asp-Glu-Ala-Asp)-box polypeptide-4 (Ddx4), and stemness properties  as well as the ability to differentiate in vitro into oocyte-like cells. However, the discovery of OSCs contrasts with the popular theory that there is a numerically defined oocyte pool for female fertility which undergoes exhaustion with menopause. Indeed, in the ovarian cortex of postmenopausal women OSCs have been detected that possess both viability and capability to differentiate into oocytes, which is similar to those observed in younger patients. The pathophysiological role of this cell population in aged women is still debated since OSCs, under appropriate stimuli, differentiate into somatic cells, and the occurrence of Ddx4 The theoretical physiology of mammalian fertility has long supported the belief that a fixed pool of oocytes, including approximately 100 progenitors during the time of puberty in women, is committed to providing the mature oocytes that span the duration of female fertility, and that this ovarian reserve undergoes a progressive decrease with aging until complete exhaustion occurs at menopause .Observations of OSCs by independent groups of investigators provided evidence of the existence of OSCs within the murine ovarian cortex ,4,5. ImpDrosophila as vasa [The orthologue of Ddx4 was originally discovered in  as vasa ,8. A vas as vasa . In huma as vasa ,11.+ cell subset [Although Ddx4 is a component of germ cell granules and was originally described in the cytoplasm of these cells, recent studies have suggested that the C-terminal domain of the protein is expressed on the cell surface of a small subset of human ovarian cells located within the cortex. In fact, in addition to their detection, by using specific antibodies to this portion of the molecule, it is even possible to isolate these cells by immunomagnetic procedures to enrich the Ddx4l subset . Such chl subset . Howeverl subset . AdditioThe primary utilization of OSCs is putatively directed at reconstituting the ovarian repertoire in women with ovarian insufficiency because of the ability of OSCs to differentiate into mature, competent, and functional oocytes both in vitro and in vivo, as detected in mice . Thus, iBeyond these potential applications of OSCs, there is speculation as to the pathophysiological role of these cells, in particular in the ovarian cortex of postmenopausal women. The expression of Ddx4 on these cells confirms their staminal condition; this potentially may be related to the activation of unknown molecular mechanisms, thereby driving pathological events in aged ovaries such as cancer, rather than merely guaranteeing an ovarian reserve with aging. Here, we review the current literature on OSCs, focusing on their debated pathophysiological role in post-menopausal age, while describing preliminary data by our group in support of the high plasticity and pluripotency of these cells, even in menopause.The traditional theory regarding a fixed ovarian reserve during the female mammal reproductive lifetime prevailed until 2004, when Tilly and colleagues provided the first evidence of OSC existence in the postnatal mammalian ovary .+ cells expressing synaptonemal complex protein (SYCP3), a meiotic cell marker, in the ovarian surface epithelium (OSE). These cells were shown to incorporate bromodeoxyuridine into their DNA, thereby supporting the ability to sustain follicle renewal in relation to mitotic activity. Also, they found healthy maturing follicles in the ovaries of mice with ovarian failure after sterilization by intensive busulfan treatment. Finally, once ovarian fragments of wild-type adult mice were implanted in the ovaries of transgenic mice expressing the reporter gene for green fluorescence protein (GFP), the authors observed the occurrence of GFP-negative oocytes surrounded by GFP-positive granulosa cells, suggesting that the transgenic OSCs migrated into the graft and developed new follicles in adult mice. For their ability to restore folliculogenesis during postnatal life, these cells were thus considered adult OSCs in mammals [By enumerating the follicles in ovarian sections, Tilly et al.  revealed mammals .Following their original description of OSCs in the ovarian cortex, Tilly et al.  later de+ cells were infected with the MSCV-PGK-GFP viral vector and injected into the ovaries of infertile mice, these cells underwent spontaneous differentiation into oocytes from which viable GFP-positive offspring were generated [However, both isolation and culture of OSCs remained elusive until 2009, when Zou and co-workers  successfenerated .+ cells that appeared very small (4 μm diameter) and expressed primordial germline markers. However, once established in vitro, these cells underwent differentiation to mature oocytes, with a larger diameter of up to 50 μm, and expressed terminal differentiation markers such as growth differentiation factor-9 (GDF-9), ZP glycoproteins, newborn ovary (NOBOX), and both meiosis markers Y-box (YBX)-2 protein and SYCP3. The authors extended these data in vivo by injecting GFP-transduced Ddx4+ cells into human ovarian cortical biopsies and observed the formation of follicles containing GFP-positive oocytes 2 weeks after xenotransplantation into NOD/SCID mice. They concluded that the ovaries of fertile women, in a manner similar to those of the adult mouse, harbor mitotically active germ cells capable of generating oocytes both in vitro and in vivo [In a subsequent study, Tilly and co-workers  purified in vivo .In agreement with these findings, other authors have described in the OSE of different mammals two separate populations of OSCs, namely very small embryonic-like stem cells (VSELs) with a 2–4 µm diameter and slightly bigger (5–8 µm) committed progenitors ,17. The +;Ddx4-Cre) to follow in vivo both proliferation and differentiation of Ddx4+cells. In this mouse model, Ddx4 promoter was found to drive the Cre recombinase expression in germline Ddx4+cells with a final effect of inducing recombination at a rainbow cassette composed of four open reading frames (ORFs) coding different fluorescent proteins. Thus, Ddx4 expressing cells were distinguished from somatic cells, namely Ddx4-negative cells, and in postnatal mouse ovaries the former were found to be mitotically inactive and did not contribute to oocyte formation during the de novo folliculogenesis. Moreover, in cultures of ovarian cells from these transgenic mice, only Ddx4-negative cells formed colonies with a morphology similar to OSCs. However, reverse transcriptase-polymerase chain reaction (RT-PCR) analysis demonstrated that these cells were not germline for their lack of germ markers such as OCT-4, STELLA, or Ddx4, or the pluripotent stem cell marker SOX-2. These results refreshed the traditional view that neo-oogenesis does not occur in mammals after birth and that no mitotically active Ddx4+germline progenitors exist in adult mouse ovaries [Despite these results, a few controversial observations were also raised . Zhang a ovaries .Subsequently, Niikura and co-workers  reported+ cells with a high degree of plasticity.Beyond animal models, in 2013 Stimpfel and colleagues [+ cells from adult human ovarian cortex samples, retrieved by mechanical detachment and a fluorescence-activated cell sorting (FACS) procedure. They isolated several Ddx4+ cell subsets separated in relation to the expression of distinct Ddx4 transcripts and levels of progenitor cell markers such as aldehyde dehydrogenase 1 (ALDH1) that were able to develop into oocyte-like structures [In a subsequent study, Clarkson and co-workers  reportedructures .+ cells can be detected and purified not only from fertile women but even from those of postmenopausal age [We have also recently shown that Ddx4usal age . These c+ cells to a lesser extent in postmenopausal than in premenopausal women [Further phenotype analysis showed that the oogonial markers stage-specific embryonic antigen (SSEA)-4 and FRAGILIS were present on Ddx4al women . Howeveral women .+ cells per cm3 of ovarian cortex, but the efficiency of differentiation into mature oocytes did not differ significantly between non-menopausal and menopausal women (p = 0.22) [However, several concerns still remain as to the biologic properties of these cells in adult human ovaries. Both size and quantitation in the cortex are not uniformly assessed by different authors. While Virant-Klun and co-workers defined as mature oocytes cultured cells with a diameter of 35–90 μm , we also = 0.22) .+ stem cells derived from the ovarian cortex of women in pre-, peri-, and postmenopausal age, with the exception of a 73-year-old patient whose ovarian cell culture did not generate colonies [In contrast with our observations, Stimpfel and co-workers  observedcolonies .+ OSCs into oocytes has been repeatedly and well proven in vitro, no data are presently available as to the significance and fate of these cells in vivo, under physiological conditions. It has been demonstrated that OSCs express follicle-stimulating hormone (FSH) receptors and are sensitive to FSH [Overwhelmingly, the physiopathological role and putative evolutionary meaning of these cells in postmenopausal women have yet to be defined and, although the differentiation of Ddx4e to FSH , thus suDrosophila has been directly related to similar alterations in brain tumors, supporting the hypothesis that germline molecular traits are involved and contribute to carcinogenesis [Although Ddx4 is prevalently expressed in germ cells as a fertility regulator, growing evidence in different organisms describes the involvement of this molecule in several processes of somatic cells and, in some cases, in contributing to tumorigenesis . In thisogenesis .In fact, Ddx4 is defined as a translational regulator of specific mRNAs in the germ lineage and participates in the generation of Piwi-interacting RNAs (piRNAs) that protect animal genomes against transposons and are essential for fertility ,24. More+ cells in epithelial ovarian cancer (EOC) samples as well as in ovarian tumor cell lines [Several investigators have demonstrated the occurrence of Ddx4ll lines ,27,28. Ill lines  found thll lines .Moreover, by analyzing 59 samples of different ovarian tumors, Kim and co-workers  found th+ cells appeared small and round (5 μm diameter) and expressed the pluripotency-related molecule SOX-2 as well as the primordial germ cell marker STELLA along with Ddx4. Once cultured in vitro, these cells proliferated and generated tumor-like structures. Since Ddx4 acts as positive translational regulator of proteins involved in the cell cycle, these results support the hypothesis that Ddx4+ cells in EOC represent the cancer stem cell component capable of proliferating and differentiating under specific stimuli. On the other hand, tumor and germ cells share several common features such as high telomerase activity, high proliferation rate, and migration potential, suggesting that the molecular pathways driving carcinogenesis are similarly involved in germ cell development [A similar cell population with the stemness phenotype was also found in borderline ovarian cancer . In thiselopment .A stem cell niche prone to malignant transformation was identified in the ovarian hilum region, at the junction between OSE, mesothelium, and tubal epithelium. Although Ddx4 was not investigated in these studies, the niche-forming cells expressed stem or progenitor cell markers such as ALDH1, leucine-rich repeat-containing G-protein coupled receptor-5 (LGR-5), lymphoid enhancer binding factor-1 (LEF-1), CD133, and cytokeratin-6B (CK-6B), and were able to generate tumor spheres in vitro. Their tumorigenic potential was confirmed by silencing TP53 and Retinoblastoma-1 (RB1) as oncosuppressor genes that are frequently mutated in ovarian cancer. In fact, the loss of both proteins induced a significant increase in the proliferation as well as development of high-grade serous adenocarcinoma in xenograft mouse models .+ cells detected in OSE is still debated, but it is a common opinion that these cells, under different stimuli, are not only capable of promoting neo-oogenesis but also participate in epithelium repair after ovulation and ovarian cancer development  expressing CD105, CD44, CD90, CD146, and CD73 as typical markers, and are capable of differentiating into cells belonging to all germ layers, under appropriate stimuli [+OSCs, while ontogeny-derived MSCs were not investigated in Ddx4 expression in order to speculate their putative germinal origin.Also, Stimpfel et al. have recently shownthat the above-mentioned stem cell fraction, namely Ddx4 stimuli . However+ OSCs and found interesting information concerning the putative fate of these cells in ovaries during the postmenopausal stage of women. By applying a previously described protocol [+ OSCs from the ovarian cortex of post-menopausal women undergoing oophorectomy for non-malignant diseases. In order to investigate their capability to acquire a “mesenchymal-like” phenotype, we exposed these cells to both FSH and epidermal growth factor (EGF) that are well known to promote the epithelial-to-mesenchymal transition (EMT) in different cell models [We have recently explored this aspect in Ddx4protocol , we isoll models ,39,40,41+ OSCs under FSH endocrine stimulation may perhaps resemble the hormonal condition typical of the menopausal stage in women in which ovary fibrosis may be dependent on high FSH serum levels.Such a mesenchymal phenotype transition of Ddx4+ cells, whose differentiation is possible even in postmenopausal women under the influence of both hormonal and micro environmental factors.Further experiments are needed to better characterize the somatic properties of these cells, although the data presently available support the germinal origin of ovarian MSCs and the high plasticity of Ddx4+ OSCs in the human ovarian cortex and their germ lineage differentiation in vitro after recruitmenthas been definitively determined, it is thus conceivable to consider their future potential applications in regenerative medicine.Once the existence of Ddx4During the reproductive period of women until menopause, ovarian neo-oogenesis induced by OSCs may contribute not only to the development of novel techniques to efficiently restore female fertility in several conditions of ovarian failure, such as early ovary exhaustion, but would also enable fertility preservation for oncologic patients undergoing chemotherapy or other gonadotoxic cancer treatments . DespiteParticularly in ovarian insufficiency, the recruitment of OSCs and their culture in vitro to generate mature oocytes, followed by fertilization and subsequent implantation in the uterus, would bean attractive alternative to the oocytes obtained from ovulations induced in vivo by repeated hormonal stimulation. This procedure is largely utilized by clinicians in medical centers enrolled in the treatment of infertility in women  and, altTo avoid repeated hormonal stimulations in oncologic premenopausal women, ovary cortex cryopreservation and transplantation to restore a woman’s fertility is currently adopted only in selected institutions and is encumbered by the high risk that transplanted autologous oocytes may not result in natural fertilization, while patients still require, even at a lower dosage, hormone stimulation . By contIn contrast with the putatively intensive utilization of OSCs in reversing ovarian failure in premenopausal women, the presumptive use of this model of regenerative medicine in the postmenopausal time period appears limited, if contextualized to reproduction. Reproductive aging is indeed characterized by a progressive decline in fecundity and fertility through reduced ovarian function , which aIn general, the in vitro oocyte recruitment from OSCs provides innovative approaches for the treatment of both primitive and secondary infertility. The main advantage in restoring the fertility of cancer patients by OSCs lays in the opportunity to avoid intensive hormonal stimulation that could increase the risk of metachronous or delayed hormone-dependent carcinogenesis. On the other hand, replacement of oocytes in the ovarian cortex of postmenopausal women may be useful in regulating the hormone imbalance typically encountered in aging and probably may be efficient in restraining the onset of pathological conditions associated with age-related hypo-oestrogenism in postmenopausal women.Recent advances in the field of regenerative medicine have focused on the application of OSCs, which, because of their ability to differentiate into oocyte-like cells in vitro, are considered a promising therapeutic approach to infertility and menopause. Indeed, the evidence of OSC occurrence in the ovarian cortex of non menopausal and menopausal women, and the ability of these cells to differentiate to form mature oocytes in vitro, strongly emphasize their putative use in the treatment of ovarian insufficiency.+ cells are involved in several biological processes of somatic cells and that they may also contribute to carcinogenesis in ovarian aging. Evidence that small Ddx4+ cells, cultured with FSH and EGF, acquire the MSC phenotype supports the concept of pluripotency and plasticity typical of stem cells.However, based on their stemness, occurrence in postmenopausal women, and hormone sensitivity, particularly to FSH, it remains a possibility that Ddx4In conclusion, beyond the unknown physiologic role of these cells during postmenopausal age in women, their putative utilization in balancing the endocrine derangements related to aging should be considered in future studies aimedat preventing the severity of some conditions typically associated with defective hormonal function in menopause.


Advances in genome science in the last 20 years have led to the discovery of over 50 single gene causes and genetic risk loci for steroid resistant nephrotic syndrome (SRNS). Despite these advances, the genetic architecture of childhood steroid sensitive nephrotic syndrome (SSNS) remains poorly understood due in large part to the varying clinical course of SSNS over time. Recent exome and genome wide association studies from well-defined cohorts of children with SSNS identified variants in multiple MHC class II molecules such as HLA-DQA1 and HLA-DQB1 as risk factors for SSNS, thus stressing the central role of adaptive immunity in the pathogenesis of SSNS. However, evidence suggests that unknown second hit risk loci outside of the MHC locus and environmental factors also make significant contributions to disease. In this review, we examine what is currently known about the genetics of SSNS, the implications of recent findings on our understanding of pathogenesis of SSNS, and how we can utilize these results and findings from future studies to improve the management of children with nephrotic syndrome. Nephrotic syndrome (NS) is the most common glomerular disease seen in the pediatric age group. It is the second most common kidney disease seen in pediatric nephrology clinic, the most common being congenital malformations of the kidney and the urinary tract. It is characterized by massive proteinuria, hypoalbuminemia, peripheral edema and hyperlipidemia . The preNephrotic syndrome in children is generally classified into steroid sensitive nephrotic syndrome (SSNS) and steroid resistant nephrotic syndrome (SRNS) based on the initial response to corticosteroid therapy at presentation. This classification resulted from the International Study of Kidney Disease in Children (ISKDC) studies in the 1970s, which showed that irrespective of morphological changes on kidney biopsy, the most important prognostic factor in NS is the response to corticosteroid and other immunosuppressive therapies . ChildreWhile the most important classification of NS is based on initial response to therapy, other classification schemas exist as well. For example, children with onset of nephrotic syndrome in the first 3 months of life are classified as having congenital nephrotic syndrome (CNS) and it is well known that about 80% of children with CNS will have genetic NS, with most being therapy resistant . While oThe etiology of idiopathic childhood nephrotic syndrome has remained elusive for decades. However, secondary causes such as infections , malignancy , autoimmune disorders , and drug associated  have been reported . More reMassive urinary loss of proteins the size of albumin or greater is the hallmark of nephrotic syndrome . Other f2 per 24 h. This barrier consists of three distinct layers, namely the fenestrated endothelial cells, the glomerular basement membrane, and the specialized visceral epithelial cells, the podocytes. The foot processes of adjacent podocytes interdigitate to form the slit diaphragm. Our recent understanding of the glomerular function now credits the slit diaphragm as a major barrier to the filtration of albumin (The glomerular filtration barrier (GFB) effectively limits the urine loss of albumin and other higher molecular weight proteins to <100 mg/m albumin . HoweverAccumulated evidence points to the role of T and B cell disorders in the pathogenesis of steroid sensitive nephrotic syndrome (SSNS). All current therapeutic agents for SSNS act by either depleting T and B cell populations or by modulating their functions . For exaThe exact mechanism of how disorders in the immune systems cause increased permeability of the glomerular filtration barrier is not fully understood. However, dysregulation of different cytokines expressed by activated immune cells like the T cells have been reported during relapse of NS . Also, rAnother theory that explains proteinuria in NS is the presence of soluble circulating permeability factors capable of increasing the loss of albumin and higher molecular weight proteins into the urine. This theory considers the normal kidney as being in an abnormal milieu . SeveralSome of the putative soluble circulating permeability factors include cardiotrophin-like cytokine 1 factor, soluble urokinase-like plasminogen receptor (suPAR), hemopexin, radical oxygen species, vascular endothelial growth factors, IL-13, IL-18, tumor necrosis factor-α, and angiopoetin-like 4 factor –42.These circulating factors, likely acting together, exert their effects on the glomerular filtration barrier to cause proteinuria. For example, hemopexin reduces glomerular sialoproteins and alters the actin cytoskeleton, a major contributor to podocyte structural integrity , 44.The discovery of over 50 single genes causing mostly SRNS highlights the primacy of the role of the podocytes in the pathogenesis of NS. Furthermore, current therapies of NS are known to have non-immune mediated effects on the podocyte, further underscoring its role in the pathogenesis of proteinuria in NS –48. The Generalized edema is the most common presenting feature of NS. The exact mechanism is not known. Two theories provide explanation for the pathogenesis of edema in NS . The mosHypertriglyceridemia and hypercholesterolemia characterize most cases of NS. The dyslipidemia is due to a combination of increased liver synthesis of albumin and lipoprotein to compensate for urinary loss of albumin, and disturbance in the metabolism of cholesterol . SpecifiAs mentioned previously, unlike SRNS where over 50 monogenic causes have been identified, single gene causes of SSNS have remained relatively elusive. Nonetheless, several reports point to importance of genetic factors in the risk and pathogenesis of SSNS. First, about 3% of children with SSNS have a first degree relative with SSNS . Second,PLCE1 and NPHS1 have been reported to have steroid responsive disease  gene  did not identify pathogenic variants in EMP2 .–63.PLCE1P2) gene  (60). HoMAGI2, TNS2, DLC1, CDK20, ITSN1, and ITSN2) as novel causes of disease , which includes patients with SSNS, as well as patients with partial response to corticosteroid treatment. Through a combination of homozygosity mapping (HM) and whole exome sequencing (WES) in these families as well as high throughput sequencing of an additional 1000 patients with NS, they identified recessive mutations in six genes ( disease  67). Ad. AdMAGI2TNS2 encodes tensin2, a focal adhesion molecule that like MAGI2 is known to regulate protein kinase B (PKB/AKT) activity and is vital to proper podocyte cytoskeletal dynamics identified homozygous missense mutations in a highly conserved amino acid residue of cyclin dependent kinase 20 (CDK20). Ashraf et al. posit that the products of MAGI2 and TNS2 interact and that all three proteins affect RhoGAP activity in podocytes through interactions with, or modulations of DLC1 Rho GTPase-activating protein , 71TNS2  protein .In vitro analysis by Ashraf et al. determined that the Rho GTPase-activating protein encoded by DLC1 regulates RhoA activity, which is essential for maintaining podocyte cytoskeleton dynamics  and Intersectin2 (ITSN2) as the cause of early onset NS in several families. This included homozygous missense ITSN1 mutations in two siblings in an Arab family and four other compound mutations in two additional families. WES of ITSN2 in five members of a Japanese family with two affected individuals revealed compound heterozygous mutations as a cause of disease which was then confirmed through the discovery of homozygous missense mutations in an additional NS patient. Intersectins are a family of proteins involved in clatherin mediated endocytosis and Ashraf et al. demonstrate that the products of ITSN1 and ITSN2 act as GEFs regulating Cdc42 activity  gene complex encoding MHC class II molecules required for extracellular antigen presentation  cohort demonstrated an increase in SSNS risk, a decrease in age at onset of disease, and an increase in chances of complete remission associated with patients bearing multiple risk alleles. One of the HLA risk alleles (rs28366266) lies upstream of HLA-DBR1, while the other (rs1063348) is a SNP in the 3′ untranslated region of HLA-DQB1 that is reported to reduce HLA-DRB1, HLA-DRB5, and HLA-DQB1 gene expression in the NEPTUNE cohort. This trans-ethnic analysis suggests that like HLA-DQA1, variants in HLA-DQB and HLA-DR regions may also be universal risk factors for SSNS. Furthermore, they demonstrate that these risk alleles may also affect the expression of other genes in the HLA regions, providing a complex pattern of disease inheritance that will require further studies.An extensive examination of SSNS associated risk alleles in three independent cohorts of NS patients was recently reported by Debiec et al. . This grHLA-DR/DQ alleles and SSNS in multiple independent cohorts regardless of ethnicity suggests that this region plays a critical role in SSNS pathogenesis. However, these variants fail to explain the phenotypic and ethnic variation observed in SSNS patients, or the lack of renal involvement in the numerous immunologic disorders associated with HLA variants. This suggests the presence of additional genetic factors outside of the HLA region that increase the susceptibility to renal disease. This “trigger, bullet, and target” idea proposes that much like the connection between HLA and PLA2R1 gene variants in adult membranous nephropathy, HLA variants in SSNS act as the trigger for unknown factors that connect immunologic dysfunction to renal disease . Phospholipase C gamma-2 (PLCG2) encodes a critical signaling enzyme that is required for the production of inositol triphosphate (IP3) and diacylglycerol (DAG) in response to growth and immune system receptor activation. Mutations in PLCG2 affect lymphocyte signaling and differentiation with hypermorphic variants associated with autoimmunity disorders in humans and glomerulonephritis in mice . Re. ReHLA-Don in NS . FurtherBTNL2) was found to be the lead SNP in the African patients in their French discovery cohort. Subsequent transethnic meta-analysis in all four SSNS cohorts with conditioning for two HLA loci SNPs (rs1063348 and rs28366266) revealed a significant SNP located in close proximity to the 3′ UTR of BTNL2, providing additional support for a potential role in SSNS pathogenesis. BTNL2 encodes a MHC Class II associated transmembrane protein that is involved in immune response regulation. Like PLCG2, variants in BTNL2 are associated with several disorders involving elevated auto-immune responses due to its role as a negative regulator of T cell proliferation and cytokine release , Angiotensin-converting enzyme (ACE), Interleukin 4 (IL4), and Interleukin 12 (IL12B promoter) have been reported –103CYP3Areported   to determine the precise mechanisms by which known immunological variants affect podocyte viability, (2) to identify novel variants that contribute to NS pathology through continued genetic analysis of large patient cohorts, and (3) to determine the key signaling pathways in podocytes onto which multiple pathogenic variants converge. Identification of these common molecular pathways is a critical step toward identification of novel effective therapeutic targets. A possible preliminary approach in this effort would be to examine changes in gene transcription during relapse and remission of SSNS. Through the knowledge acquired from studies such as these, we can start to identify potential druggable therapeutic targets.In conclusion, evidence from published studies suggest that the vast majority of SSNS cases are likely due to a complex interaction between variations in adaptive immunity, factors innate to the kidney, environmental factors and other population-specific rare genetic variants. A first step to understanding this complexity will be identification of rare genetic variants that are acting in concert with adaptive immunity to predispose patients to SSNS. Such a study can only be accomplished by large scale international collaborative studies. In addition, integration of data from such studies with epidemiologic studies and other omics study will ultimately lead to better understanding of disease mechanisms and identification of more effective and non-toxic therapies for SSNS.All authors contributed to the writing of this manuscript. BL created figures and tables. BL and RG edited 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.