Cognition is defined as the brain’s ability to acquire, process, store, and retrieve information. Pain has been described as an unpleasant sensory or emotional experience, and for experiencing pain consciously, cognitive processing becomes imperative. Moreover, evaluation of pain strongly depends on cognition as it requires learning and recall of previous experiences. There could be a possible close link between neural systems involved in cognition and pain processing, and studies have reported an association between pain and cognitive impairment. In this narrative review, we explore the available evidence that has investigated cognitive changes associated with pain. We also examine the anatomical, biochemical, and molecular association of pain and neuro-cognition. Additionally, we focus on the cognitive impairment caused by analgesic medications. There is a need to improve our understanding of pathophysiology and cognitive impairment mechanisms associated with chronic pain and its treatment. This area provides a diverse opportunity for grounding future research, aiding institution of timely interventions to prevent chronic pain and associated cognitive decline, ultimately improving patient care. The multidimensional pain experience is a prevalent complaint in clinical practice and impacts an individual’s physiologic and psychologic states. Pain is classically defined as an unpleasant sensory or emotional experience associated with actual or potential tissue damage . Thus, pObservations in the setting of chronic pain (pain persisting longer than 3 months) usually exceed the duration of the noxious stimulus and have deleterious effects on the psychosocial elements of the individual . AlthougIn this narrative review, we explore the available evidence and summarize the existing literature on the effects of pain on various cognitive changes. We also examine the anatomical, biochemical and molecular association of pain and neuro-cognition. Additionally, we focus on the cognitive impairment caused by analgesic medications. We highlight the need to improve our understanding of the pathophysiology and the mechanisms of cognitive impairment associated with chronic pain and the treatment thereof.Understanding the association between neural systems involved in pain and cognition is central to deciphering the relationship between these two entities. At the most basic level, the pain pathway consists of (1) Transduction, (2) Transmission, (3) Modulation, and (4) Perception .Noxious stimuli are transduced via a series of specialized nociceptors into a recognizable signal, transmitted through Aδ , and C fibers (pain). Most sensory fibers would then project to the dorsal root ganglion (DRG), from where the sensory input is transmitted to the central nervous system CNS; . In the N-methyl-D-aspartate (NMDA) receptor configuration and sensitivity , and the medial thalamic nuclei are important components of motivational and affective domains of pain . The thaThe descending pain pathway comprises various supraspinal components – the rostral ventromedial medulla (RVM), the dorsolateral pontomesencephalic tegmentum, and the PAG . The PAGNeuroplasticity includes the structural and functional changes that occur in the brain enabling adaptation to environmental cues, learning, memory, and rehabilitation after brain injury . In factImaging studies have suggested a spatiotemporal reorganization of brain activity in relation to chronic pain, during which the representation of pain gradually shifts from sensory to emotional and limbic structures. Thus, the transition of acute pain to chronic pain is a type of activity-induced plasticity of the limbic-cortical circuitry resulting in the reorganization of the neocortex . Evidencde novo neurogenesis throughout the peripheral and central pain circuits. Decreased BDNF levels at the hippocampus are found in chronic pain conditions, and this finding is positively linked to the development of depression-like symptoms ] and modulation of neuronal excitability  Opioid receptors are uniquely present at all the neural loci associated with pain signaling and perception . The opiOpioids have unique problems, including constipation, diarrhea, sedation, nausea, vomiting, and pruritus . Having Although opioids, TCAs, and anticonvulsant therapies inherently impact the cognitive domains, this impact is inconsistently observed over human and animal studies. The majority of human studies suggest a decrease in attention, processing, memory encoding and retrieval, reaction time, and psychomotor performance with the use of opioids, TCAs, and anticonvulsants . HoweverEndocannabinoids (ECs) are the in-built antinociceptive system of the body. Current research focuses on understanding this EC system better and maximizing its potential to provide safer pain control. The major areas of interest include – EC metabolism inhibition, Anandamide (AEA), and 1-arachidonoyl glycerol (2-AG) are the earliest recognized EC ligands in the body . ECs, AEOpioids are potent analgesics, however, considering their unique side effect profile and evidence of an emerging opioid epidemic, alternative non-pharmacological therapies are now being explored. Sensory processing of signals can be modulated by altering the attention component of cognitive processing . ModulatCognitive behavior therapy refers to the psychotherapeutic techniques used to decrease pain perception. Traditionally, it includes relaxation therapy, activity pacing, sleep hygiene, scheduling pleasant activity, identifying and modifying cognitive distortions . CBT hasMindfulness meditation and mindfulness-based cognitive therapy have shown therapeutic benefit and improved sensitivity to opioid-based treatment in patients with chronic lower back pain , 2020. MClinical and preclinical studies indicate a definitive link between pain and cognitive domains. However, the precise underlying psychological and neural mechanisms, the cognitive deficit associated with each chronic pain condition, and the role of subjective factors, the nature and the duration of the pain are yet to be elucidated. Chronic pain also results in adaptations and alterations in cognitive strategies, further adding to the heterogeneity in interpreting the primary deficit. Neuroplasticity-based reorganizational changes have an essential role in pain permanence and pain modulation and should be considered during the interpretation of the findings.Lack of consistent cognitive effects across studies, methods, and pain conditions highlight the need for more standardized evaluation methods to allow comparisons to identify global and precise cognitive deficits. The use of different batteries of neurocognitive tests and pain questionnaires prevent a head-on comparison between different chronic pain conditions and their impact on the cognitive domains. The tests should have the sensitivity to identify the intensity of pain and the effect of pain on various cognitive domains. These limitations and the complex nature of the interconnection between pain and cognitive neuro-matrix makes evaluative conclusions rather difficult. Future studies should be designed to address these issues. Furthermore, current research lacks evidence to draw inference for longer-term impacts on cognition in patients with chronic pain. Chronic pain-based animal models have been used to understand the implication of pain on long term cognitive domains; however, these models are limited in their ability to mimic the motivation-affective and evaluative aspects of pain.Future studies should be modified to incorporate psychophysiological, psychophysical, pharmacological, and brain imaging techniques to evaluate cognitive effects in the setting of chronic pain. Such studies would provide a multidimensional understanding of cognitive effects and provide insights into the underlying mechanisms and outcomes of pharmacotherapy. The current knowledge paves the way for future research to understand better the cognitive domains and their connection with various pain dimensions to improve therapeutic management and avoid unfavorable cognitive outcomes.The past two decades have provided tremendous insights into the multifaceted role of pain in modulating cognitive domains and vice versa. This comprehensive review focused on the multidimensional role of pain in several cognitive domains including attention, memory, processing, executive functioning, decision making, psychomotor efficiency and reaction time highlights the current understanding of the intricate association between pain and cognition. We also provided insights into the role of various pharmacologic and non-pharmacologic approaches in the management of pain and the cognitive implications associated with it. It is imperative to understand the precise nature of the cognitive task affected by chronic pain. This understanding is crucial to tailor pain management therapy to the requirement of the individual. This personalized multimodal pain management allows improvement in long term quality of life and facilitates recovery.TK and VR: involve in the planning, critical thinking, and writing the manuscript. Both authors contributed to the article and approved the submitted version.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.


Meanwhile, a number of host factors including receptors are required for the infection of PEDV via interacting with the viral proteins, thereby affecting the reproduction of PEDV and contributing to its life cycle. In this review, we provide an updated understanding of viral proteins and host factors, as well as their interactions in terms of PEDV infection. Additionally, the effects of cellular factors, events, and signaling pathways on PEDV infection are also discussed. Thus, these comprehensive and profound insights should facilitate for the further investigations, control, and prevention of PEDV infection.Porcine epidemic diarrhea virus (PEDV), a coronavirus pathogen of the pig intestinal tract, can cause fatal watery diarrhea in piglets, thereby causing huge economic losses to swine industries around the world. The pathogenesis of PEDV has intensively been studied; however, the viral proteins of PEDV and the host factors in target cells, as well as their interactions, which are the foundation of the molecular mechanisms of viral infection, remain to be summarized and updated. PEDV has multiple important structural and functional proteins, which play various roles in the process of virus infection. Among them, the S and N proteins play vital roles in biological processes related to PEDV survival  Porcine epidemic diarrhea (PED) is an acute and highly contagious intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV) . PEDV caAs a member of the Nidovirales order and Coronaviridae family, PEDV has a typically corolla-shaped, mostly spherical morphology, with a diameter ranging from 95 to 190 nm (including spikes) and an average of 130 nm. The sequences located at the 3′ side of the PEDV genome encode four structural proteins, namely, the spike protein , membrane protein , envelop protein , and nucleocapsid protein  .Similar to other coronaviruses (CoVs) , the infCoronaviruses’ 5′UTRs vary in length, ranging from 209 to 528 nucleotides. The 5′UTR of coronaviruses has a short ORF starting with AUG at a similar location that encodes 3–11 amino acids . The rolThis spike (S) protein is a type I glycoprotein, and three S proteins of PEDV forming a rod-shaped functional spike trimer located in the outermost layer of virus particles are the foundation for its multifunction, such as the binding of PEDV to other molecules and the entry of virus into target cells . Based oThe M protein encoded by PEDV is an essential membrane glycoprotein in the envelope. Growing evidence indicates that the M protein has multiple functions. Firstly, it can be utilized as an important antigen for developing diagnostic reagents. Indirect enzyme-linked immunosorbent assay (ELISA) using the recombinant PEDV M protein as antigen displays high sensitivity and specificity in detecting the PEDV antibody . SecondlThe N protein of PEDV is the only phosphorylated nucleocapsid protein among the known structural proteins of CoVs. As a major structural protein of PEDV, the mRNA and protein contents of the N reach to the highest during the process of viral infection. The multifunctional property of the N protein manifests in several aspects: (1) its being bound by viral RNA provides a structural basis for the helix nucleocapsid, while the resultant product is recognized by the M protein through their interaction, and then packaged into viral particles to form the core of CoVs ; (2) as The E protein is a small membrane glycoprotein, which is distributed on the surface of the virus envelope. According to the primary and secondary structure analysis of this protein, it can be divided into three parts: the short amino terminal hydrophilic region, the α helix structure with a length of about 25 aa containing the transmembrane region, and the long carboxyl terminal region . So far,As a unique feature to other coronaviruses such as TGEV and SeCoV, the sequence located between the PEDV S and E genes is responsible for encoding the non-structural ORF3 protein. It contains four transmembrane regions and forms a homologous tetramer structure . As an avia targeting the NF-κB pathway during the viral infection  is widely distributed in the small intestine and kidney of pigs . The funIt is recognized that a large number of the main receptors for many viruses belong to glycoprotein or glycolipid, with sialic acid or sialic acid derivatives at the end . In thisHeparan sulfate (HS) is known for its role as an attachment factor by many viruses to enter cells . Its simEpidermal growth factor receptor (EGFR) is widely distributed on the membrane surface of mammalian epithelial cells and fibroblasts . Importain vivo dissemination , specifically expressed on the surface of dendritic cells (DCs), is a C-type lectin-like cell-surface receptor with multiple functions. Its expression is also found in gastric and intestinal mucosa and other epithelial cells. Initially, DC-SIGN was proved only to be a pattern recognition receptor (PRR) and adhesion molecule for dendritic cells to recognize pathogenic infections and participate in the innate immunity of organisms. Accumulating evidence has indicated that DC-SIGN also acts as the receptor of many viruses for infecting hosts and the mediator of virus immune escape. Importantly, DC-SIGN, together with other PRRs, can identify and capture viruses, further swallowing and storing them to evade lysosome degradation, then participate in antigen presentation, thereby achieving the mediation of virus infection and mination . Studiesmination . Human amination . Based oin vitro proliferation of PEDV has been described (Type II transmembrane serine proteases (TTSPs), being a family with more than 20 members, can be mainly divided into four subgroups: HAT/DESC, hepsin/TMPRSS, matriptase, and corin . TTSPs cescribed . These sescribed . Althougin vitro and in vivo through modulating related proteins of the tight junction and adhesion junction in the early stage of infection  protein, derived from the main transcription form and the longest transcript of the NPM gene, is mainly located in the granular region of the nucleolus. As a nuclear shuttle protein, NPM1 plays multiple roles in the nucleolus including centrosome duplication, ribosome biogenesis, intracellular transport, apoptosis, and mRNA splicing . ImportaHeterogeneous nuclear ribonucleoprotein (hnRNP) is a general term designated for the members of the RNA binding protein family, which consists of at least twenty members. Heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), one of the most abundant members of this family , can be Successful PEDV replication requires the coordinated production, processing, and assembly of each protein and nucleic acid of the virus, as well as the release of progeny viruses capable of infecting new cells from infected cells. Initially, the interaction of the same type M proteins provides a scaffold for the morphogenesis of the virus, while the interaction between the M-S and M-N facilitates the recruitment of the structural components of the virus to the assembly site . FinallyAs the first defense line against pathogenic microorganism invasion, natural immune response plays a vital antiviral role in the early stage of virus infection. The critical action of interferon (IFN) in the process of virus infection and proliferation has long been recognized. As an IFN-induced common natural immune limiting factor , BST2 coEukaryotic protein synthesis consists of three stages, namely, initiation, elongation, and termination, each of which involves a different set of protein factors. This event mainly occurs in the ribosomes within the cytoplasm, with the participation of a series of eIFs. So far, 13 translation–initiation factors have been identified in eukaryotes, of which eIF3 has the largest molecular weight (∼650 kDa) and is composed of 8–13 polypeptides . Eukaryocis-trans isomerase D (PPID), also named as CyP40, is a member of the peptidyl-prolyl cis-trans isomerase (PPIase) family. It is conducive to protein folding, ligand binding, and nuclear sorting of glucocorticoid, estrogen, and progesterone receptors  in the intestinal villi of pigs, while the most common in vitro (Porcine epidemic diarrhea virus whole inactivated and attenuated virus vaccines have played an effective role in the prevention and control of PED . Besidesin vitro . Interesin vitro . Likewisin vitro . AdditioViruses are obligate intracellular parasites that are limited by the ability of their genomes. Accordingly, all viruses evolve the capability to hijack host factors for their own replication. Meanwhile, host cells also develop complex signaling networks to detect, control, and eradicate invading viruses, although these antiviral pathways are often circumvented, suppressed, or disrupted by various viral anti-mechanisms. Thus, virus–host interactions represent an ongoing evolutionary arm race to perfection at the molecular and cellular levels. Therefore, it is of far-reaching significance to deeply study the pathogenesis of PEDV and identify PEDV receptors and related host factors, thereby providing more druggable targets for the prevention and treatment of PEDV.YH performed the literature study, drafted the structural design of the review, and wrote the manuscript. XX, LY, and AW contributed intellectually with the critical revision of the manuscript. All authors have read and approved the final manuscript.AW is employed by PCB Biotechnology, LLC. The remaining 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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The human endometrium plays a vital role in providing the site for embryo implantation and maintaining the normal development and survival of the embryo. Recent studies have shown that stress is a common factor for the development of unexplained reproductive disorders. The nonreceptive endometrium and disturbed early maternal-fetal interaction might lead to infertility including the repeated embryo implantation failure and recurrent spontaneous abortion, or late pregnancy complications, thereby affecting the quality of life as well as the psychological status of the affected individuals. Additionally, psychological stress might also adversely affect female reproductive health. In recent years, several basic and clinical studies have tried to investigate the harm caused by psychological stress to reproductive health, however, the mechanism is still unclear. Here, we review the relationship between psychological stress and endometrial dysfunction, and its consequent effects on female infertility to provide new insights for clinical therapeutic interventions in the future. In recent years, researchers have focused on the role of endometrium in infertility, assuming that endometrial dysfunction might contribute to a large part of pregnancy failure. Thus, reproductive scientists have performed various procedures to analyze the endometrium of patients with recurrent implantation failure (RIF), including hysteroscopy, scratching of the uterine cavity before embryo transfer. Recently, the high-throughput techniques, such as RNA-seq has been utilized to identify new biomarkers of endometrial receptivity to improve the clinical pregnancy rate in IVF-ET technology. However, there have been no relevant advances in diagnosing and improving endometrial receptivity at the molecular level.Infertility is a disease characterized by the failure to establish a clinical pregnancy after 12 months of regular and unprotected intercourse. Studies have estimated that approximately 12% of married women have difficulty getting pregnant or maintaining a pregnancy  and apprThe human endometrium is a highly dynamic tissue that is cyclically shed, regenerated, and remodeled. This is mainly regulated by changes in estrogen and progesterone secreted by the ovaries, and the endometrium is only receptive to implantation for a few days during the midpoint of the menstrual cycle . Spatiotin vivo, and psychological distress might affect the secretion and regulation of the endocrine hormones  axis is a tightly regulated system that controls the human endometrium , 47. FSHPregnancy is a physiological process involving multiple independent and cascading performance events, such as embryo implantation, decidualization, placental development, and final fetal delivery . The sucFor more than 80 years, scientists have been interested in investigating endometrial receptivity, leading to an in-depth understanding of embryo-endometrial cross-talk and implantation-related processes. In humans, the endometrium receptivity is optimum during the mid-luteal phase of a regular cycle, thus, the LH surge before ovulation occurs between days 6-10 , 52. TheMolecular evidence indicates that locally produced signaling molecules, including cytokines, growth factors, homeobox transcription factors, lipid mediators, morphogens and ovarian hormones, act as autocrine, paracrine, and juxtacrine factors to determine the uterine receptivity . In thisMany important signaling pathways are known to regulate cell proliferation, differentiation, and apoptosis, as well as endometrial function. Different from most mammals, before the establishment of endometrial receptivity, human endometrial stromal cells (HESCs) initiate differentiation  stimulated by progesterone in the absence of embryos , 44, 50.The previous section describes that the HPO axis-mediated secretion of hormones determines the functional differentiation and response of the endometrium. Also, various paracrine and autocrine regulatory molecules combined endocrine hormones drive the functional differentiation of the endometrium during the menstrual cycle. Any factors that lead to changes of paracrine and autocrine that regulate endometrial function will cause the dysfunction of the endometrium. In recent years, studies have suggested the role of psychological stress in triggering unexplained infertility and miscarriages may be associated with dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis. The abnormal abundance of neurotrophic factors, sex steroids, metabolic and/or inflammatory cytokines can cause alterations in neurotransmitters, intracellular signaling, gene transcription, and translation. Epigenetic change is a regular and natural occurrence in the regulation of gene expression and activity. It has been proposed that epigenetic changes also contribute to the short-term and long-term imbalances in neuronal function and behavior , 94, whiThe primary endocrine components involved in the response of the stress system include the HPA axis and locus coeruleus-norepinephrine (LC/NE) autonomic nervous system  Figure , 98. Whein vitro, acting through the CRH receptor  . Stress receptor . In acutreceptor . The resreceptor –108. Chrreceptor . ChronicThe regulation and integration of biological, psychological, and social factors in human physiology benefit from the analysis of precise biomarkers that indicate accurate stress responses. In the past decade, there has been an extensive growth in the use of RNAi in cells, as well as transgenic, knockout, and conditional knockout mouse models, which provide valuable insights into the stress-induced endometrial dysfunction. Additionally, psychological stress not only interferes with the functioning of the endometrium by affecting endocrine hormones but also directly regulates the local microenvironment of the endometrium.The human endometrium contains specific cells that undergo cyclic changes under the influence of steroid hormones as well as numerous local paracrine and autocrine factors. The stressors trigger the endometrial endoplasmic reticulum (ER) stress to deplete energy and cause periodic changes in the menstrual cycle . EmerginThe expression of the mouse uterine adrenergic receptor Adrb2 temporarily increases during the peri-implantation period. Abnormal activation of the receptor Adrb2 signal can destroy the space between embryos during implantation. The activation of the cAMP-PKA pathway can lead to a significant increase in the loss of mid-pregnancy and is known to be accompanied by a specific down regulation of LPA3 . Previouin vivo . This suggested that GC signaling regulated important biological functions, including immune cell trafficking and embryonic development . Brain-din vivo . This hoin vivo . The expin vivo . Additioin vivo .Thus, psychological stress is closely related to the functioning of the human endometrium. The stressors not only interfere with the reproductive hormones that regulate the endometrium but also directly participate in the regulation of the microenvironment of the endometrium , uterine scratching before embryo transfer, and stem cell therapy –135. Howin vivo and to understand how these mechanisms work in the human endometrium. Psychological interventions for women with infertility have the potential to decrease anxiety and depression and may well lead to significantly higher pregnancy rates. Therefore, infertility patients must be psychologically counseled and supported as they go through assisted reproductive technology (ART) treatment. We recommend that the Society of Reproductive Medicine or the Center of Reproductive Medicine to incorporate psychological assessment and intervention into the routine diagnosis and treatment of ART. In addition, how do epinephrine or glucocorticoids caused by stress affect the nervous system and reproductive system? How do the signals between the nervous system and the reproductive system influence and feed back to each other? Is the abnormal reproductive function caused by stress reversible? What kind of psychological intervention is the most effective for infertile couples? These are all worth exploring and answering in the future.Here, we evaluated the effects of psychological stress on the human endometrium and subsequently on pregnancy outcome. It is necessary to understand how these mechanisms work during gestational stress J-xW and S-bK prepared the manuscript. SL give an intensive suggestion and discussion. All authors contributed to the article and approved the submitted version.This work was supported by National Natural Science Foundation of China (81901481 to J-xW).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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Research efforts in the past few years have transformed our understanding of the structure and multifaceted roles of the cells and their intricate crosstalk in development and disease pathogenesis. In this review, we present a new wave of technologies that include glomerulus-on-a-chip, three-dimensional microfluidic models, and organoids all promising to improve our understanding of glomerular biology and to enable the development of GFB-targeted therapies. Here, we also outline the challenges and the opportunities of these emerging biomimetic systems that aim to recapitulate the complex glomerular filter, and the evolving perspectives on the sophisticated repertoire of cellular signaling that comprise the glomerular milieu.The glomerulus is a compact cluster of capillaries responsible for blood filtration and initiating urine production in the renal nephrons. A trilaminar structure in the capillary wall forms the glomerular filtration barrier (GFB), composed of glycocalyx-enriched and fenestrated endothelial cells adhering to the glomerular basement membrane and specialized visceral epithelial cells, podocytes, forming the outermost layer with a molecular slit diaphragm between their interdigitating foot processes. The unique dynamic and selective nature of blood filtration to produce urine requires the functionality of each of the GFB components, and hence, mimicking the glomerular filter  Howard SkipperThe glomerular filtration barrier (GFB) is a highly specialized interface responsible for blood filtration that is charge and size selective. While its functionality and integrity are maintained by a constant interaction between glomerular endothelial cells (GECs), the glomerular basement membrane (GBM), and podocytes , they arin vivo models, where these traits are preserved. Using rodent models is regarded as the gold standard in GFB research. Mice have been used extensively to study the GFB, given the advantage that the complexity of the GFB microenvironment can be fully recapitulated, that there are several available genetically defined strains and the relative ease of single gene targeting  line, developed by in vivo has been achieved by direct labeling or indirect measurements  that is regulated via macula densa cells in the distal tubule and the myogenic response  cultures are a simple culture system to study glomerular cell-specific effects, as they provide screening of large numbers of conditions and treatments that would otherwise not be possible in vivo . To studvia endothelin receptor A after media transfer  affected the glomerular microvasculature (Exposure of GECs to laminar shear forces found culature . Their fculature . DiffereThe models described so far provide robust high-throughput, high-content reductionist assay systems. They have provided a wealth of information on the fundamental biological and disease processes of the GFB. Nevertheless, they provide a limited physiological context of the filtration barrier. Since there is growing awareness of the interconnections between cells and the ECM surrounding them, there is substantial effort by the community to develop model systems that can better reflect the complex microenvironment cells encounter in a tissue.Organs-on-a-chip have been developed for complex organs such as liver , heart , gut Ki, lungs , 2012, ain vitro model of diabetic kidney disease, Wang et al. developed a glomerulus-on-a-chip using glomeruli isolated from rats. The chip consisted of five channels, a capillary in the middle and collection channels on the outside, with the channels in between filled with gel. Isolated glomeruli were injected in the capillary channel and allowed to attach for the cells to spread and form a barrier under flow. GECs and podocytes were identified by CD31 and synaptopodin staining, respectively. High glucose treatment enhanced the permeability to proteins and increased reactive oxygen species production and podocyte detachment (in vivo setting (To study the effect of hypertension on the filtration barrier, Zhou et al. developed a glomerulus-on-a-chip using murine immortalized GECs and podocytes. The cells were separated in the chip by a polycarbonate membrane coated with basement membrane extracts, and the authors increased the flow in the upper channel of the chip harboring the GECs . Increastachment . Musah etachment . The aut setting . These m setting . The aut setting .in situ has a complex structure with intricate microvascular capillary networks in a unique geometry that could play a role in the development and function of podocytes (Given that the glomerulus odocytes , there hodocytes . They fuodocytes . This syodocytes .Current GFB 3D culture model technologies have a number of drawbacks, such as recirculating instead of a continuous flow, long culture times to achieve fully confluent layers, lack of a basement membrane, and limited throughput. However, these models still hold great promise for improving our understanding of glomerular crosstalk and their potential use for personalized and precision medicine. In the future, chips where cells can form a basement membrane without separating gels or man-made membranes will emerge, and the inclusion of mesangial cells, pericytes, and parietal epithelial cells to the chips would enable all the intricate signaling which takes place in the glomerulus.PAX2 and NPHS1 in the presence of retinoic acid. Further, co-culture with microvascular endothelial cells resulted in more compact organization of the spheroids (Scaffold-free 3D cultures are anchorage-independent models that rely on the self-aggregation of cells in specialized culture plates with ultra-low attachment coating that promotes spheroid formation. Multicellular spheroids have been shown to recapitulate physiological characteristics of tissues and tumors with regard to cell-cell contact, and allow for natural cell-ECM interactions . Glomerupheroids .These scaffold-free 3D cultures are not barrier models, and many questions remain: in particular, about the composition of the spheres. And improvement in oxygenation through integration of endothelial cells has not been examined in this setting. Today’s glomeruloid spheres can provide insights for podocyte-ECM interactions and can be adapted to medium- or high-throughput screening assays. There is still the need for culture optimization to enhance reproducibility of spheroids in culture and to study GFB components, while maintaining a small enough size for sufficient nutrient exchange. However, this area of research is moving fast, and we will undoubtedly see advances in the years to come.in vitro have led to the development of organoids, self-organized 3D aggregations of cells. Over the last few years, these developments have provided researchers the opportunity to establish near-physiological models to study human development and diseases. Organoids can be derived from embryonic stem cells or iPSCs. The kidney is an anatomically complex organ with numerous different cell types, which makes it difficult to get organoids containing all renal structures including a functional filtration barrier. As of today, organoids are premature, and as such, they do not represent ideal modeling systems for studies of the GFB; however, they hold promise to be so in the future.Attempts to fully culture organs via single-cell sequencing and have been found to contain developing podocytes, parietal epithelial cells, tubular cells, collecting ducts, and interstitial and stromal cells. Missing or underrepresented cells with current methods are GECs, mesangial cells, principal and intercalated cells (in vivo environment for vascularization, further characterization of the role of substrate stiffness can improve kidney organoid differentiation. Another limitation of the current organoid systems is the heterogeneity and batch-to-batch variation during initial formation and maturation. To address this, Dr. Little’s group have employed two different approaches for scaling up the generation of kidney organoids with less heterogeneity and higher reproducibility. Kumar et al. demonstrated a method to scale up the generation of kidney micro-organoids in suspension culture (Embryonic kidneys are divided into the metanephric mesenchyme and the ureteric bud. Nephron progenitor cells in the metanephric mesenchyme are the origin of the glomeruli, Bowman’s capsule, and the renal tubules, and stromal progenitor cells give rise to interstitial cells. The ureteric bud is the origin of the collecting ducts. During development, intricate signaling leads to differentiation of cells and the formation of a mature kidney. In order to form kidney organoids, this signaling needs to be applied to embryonic or pluripotent stem cells. With this in mind, the development of differentiation protocols for embryonic and iPSCs toward renal cells  was rapied cells , and immed cells . Hale eted cells . Geneticed cells . In addied cells , or traned cells . In the ed cells . By modued cells . They sh culture . Using t culture . Using t culture , which wDespite the many challenges that still remain for organoids to fully resemble mature human kidneys, including less off targets cells as described in detail in the review by in vitro models is paramount to elucidate the intricate signaling of cells in the GFB. Today, there is greater recognition that components of the GFB work as an integrated functional unit. As more and more new tools become available, such as iPSCs in culture and 3D model systems, we shall look to integrate these human-relevant in vitro models with data-driven and mechanistic modeling as well as artificial intelligence-driven methods that can assist with in silico drug discovery and modeling (The lack of specific treatments for diseases of the GFB is a worldwide health issue. The need for new explorative modeling , which wmodeling , opportuAs these experimental model systems continue to evolve and improve in terms of their physiological context and throughput, model systems have a huge potential to help unravel the molecular mechanisms of GFB breakdown and the pathogenic crosstalk signaling that may drive disease. These developments should minimize the use of animal models and accelerate discoveries by enabling the platforms for personalized and precision medicine to lower drug-induced adverse events, and identify new targets for treatments of kidney diseases that affect the filtration barrier.Conceptualization by KE, EL and ID. KE, EL, NA, EA and ID wrote the manuscript. All authors contributed to the article and approved the submitted version.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.


Introduction: There is an emerging interest in modulating the gut microbiota to target the gut-brain axis and improve maternal mental health in the perinatal period. This systematic review evaluated the effectiveness of prebiotics, probiotics, and synbiotics supplementation during pregnancy to reduce the risk of maternal mental health problems in the perinatal period.Methods: Electronic biomedical databases and clinical trial registries were searched from database inception through August 2020 to identify randomized controlled clinical trials (RCTs) evaluating the effect of probiotic, prebiotic, or synbiotic supplements administered to women during pregnancy on measures of perinatal depression, anxiety, and other mental health outcomes. Study selection, risk of bias appraisal, and data extraction were independently performed by two reviewers. Pooled mean differences (MD) and odds ratios (pOR) with 95% confidence intervals (CI) were calculated in random-effects meta-analyses for the outcomes of interest in the review.Results: From 3,868 studies identified through the search strategy, three RCTs of low risk of bias involving 713 participants were included, all three testing probiotics. There were no differences between probiotics and control groups in the mean depression scores  at end of follow-up. Although statistical significance was not achieved, probiotics showed an advantage in the proportion of participants scoring below an established cut-off for depression . Compared to placebo, probiotics in pregnancy reduced anxiety symptoms ; however, this advantage was not translated in a reduction in the proportion of participants scoring above an established cut-off for anxiety . There were no differences between probiotics and control groups in global mental health scores at end of follow-up .Conclusion: There is limited but promising evidence about the effectiveness of probiotics during pregnancy to reduce anxiety symptoms and reduce the proportion of women scoring ABOVE a cut-off depression score. There is a lack of RCT evidence supporting prebiotics and synbiotics supplementation for similar purposes in the perinatal period. More research is needed before prebiotics, probiotics, and synbiotics are recommended to support maternal mental health and well-being in the perinatal period.Systematic Review Registration: PROSPERO, CRD42019137158. Maternal mental health problems in the perinatal period are a global public health challenge. As many as one in five women develop depression  and/or aDysbiosis or altered community composition of gut microbiota is linked to the origins of an ever-expanding set of inflammatory and non-communicable diseases , 7. Our Not surprisingly, there is an emerging interest in microbiome modification through the administration of probiotics, prebiotics, and synbiotics, to improve aspects of the gut-brain axis . ProbiotPrebiotic, probiotic, and synbiotic supplements are increasingly been used during pregnancy to reduce the risk of maternal mental health disorders during the perinatal period, but their effects have not been systematically evaluated. The objective of our systematic review was to synthesize this emerging literature, namely to evaluate the evidence on the administration of prebiotic, probiotic, and/or synbiotic supplements during pregnancy to reduce the risk of mental health problems in the perinatal period.This systematic review was reported and conducted in accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement . A protoClinicalTrials.gov and the WHO International Clinical Trials Registry Platform), Scopus, Web of Science Core Collection, and BIOSIS (Web of Science Platform)] were conducted from database inception to August 19, 2020. The search strategy was designed by a health sciences librarian (LD) and comprised of both selected subject headings and free terms related to probiotics , prebiotics , and their combination (synbiotics) and then combined with terms for the concept of pregnancy. The search was limited to randomized controlled trials (RCTs) using the Glanville et al. , EMBASE (Ovid interface), CINAHL Plus with Full Text (EBSCOhost interface), Cochrane Central Register of Controlled Trials  evaluating the administration of prebiotic, probiotic, and synbiotic supplementation during pregnancy were considered for inclusion in the review. Studies should have been conducted in clinical  settings or in the general population and included populations of women with uncomplicated pregnancies . The intervention of interest was probiotic, prebiotic, or synbiotic supplements, alone or combined, administered orally to women anytime during pregnancy, at any dose, with the intention to treat for a minimum of seven days. Primary outcomes in the review were measures of maternal mental health  anytime during pregnancy  and/or in the first 12 months after delivery, expressed proportions of women with a diagnosis of mental health disorder, or changes in scores from baseline for questionnaire data. Studies that reported outcome measures using structured clinical interviews  or validated screening questionnaires  were considered for inclusion. Excluded from the review were review articles, editorials, letters, case series, case reports, quasi-experimental studies, other observational studies, and cross-over trials.Two pairs of independent reviewers  screened titles and abstracts generated from the searches to identify potentially relevant studies. The full text of articles deemed relevant and those whose abstracts and titles provided insufficient information were retrieved and independently assessed for eligibility in the review. Disagreements about study eligibility were resolved through discussions among reviewers until a consensus was reached.Two pairs of independent reviewers  assessed the risk of bias of primary studies using standardized instruments based on study design. Discrepancies in risk of bias assessment were resolved through discussions among reviewers until consensus was reached Risk of bias of RCTs was assessed using the Cochrane Risk of Bias (RoB) tool, which included the following critera: random sequence generation, allocation concealment, blinding of participants and personnel, bliding of outcome assessment, incomplete outcome data, selective reporting and other sources of bias . For eacThe following information was extracted from primary studies using a data extraction form: year, country, study design, characteristics of the population, intervention and comparison groups, and study outcomes. Data from the included studies was extracted by one reviewer (VD) and then independently verified for accuracy and completeness by a second reviewer (OS or MO). Discrepancies in data extraction were resolved by a consensus.I2 statistic (I2 < 25%), moderate (I2 between 26 and 74%) or (I2 ≥ 75%) . We conducted meta-analyses of RCT data using a random effects model. Pooled odds ratios (pOR) for categorical data and mean differences (MD) for continuous outcome data (when outcomes at the end of follow-up were reported using the same measurement instrument) were reported with 95% confidence intervals (CI) around the effect estimates. Forest plots were used to display individual and pooled trial results. Statistical heterogeneity across trials was quantified using the tatistic . Heterog2 ≥ 75%) . We expl2 ≥ 75%) , where aThe quality of the evidence for each outcome in the review that included pooled RCT data was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework . The GRAn = 30), not primary research (n = 15), incorrect study population (n = 2), no RCT design (n = 2), and ongoing study (n = 1). The complete references of excluded studies and reasons for exclusion is available upon request. One ongoing study , from enrollment until 6 months after birth, if breastfeeding, or before if the participants did not breastfeed for 24 h. The other trial . The results were heterogeneous across the trials. Potential sources of heterogeneity include differences in study populations. While the Slykerman et al. . Results across the trials were homogeneous.When the percentage of participants scoring above a cut-off score in the EPDS were analyzed in the two trials , 36 Fig, particiI2 = 0%). Results were homogeneous across the trials.A meta-analysis of two RCTs , 36 invoI2 = 59%).When the proportion of participants scoring above a cut-off in STAI-6 anxiety scores were analyzed , the pooI2 = 13%).A meta-analysis of two trials , 34 invoA formal evaluation of publication bias was not feasible as only 3 trials were identified in the review. Similarly, the small number of studies assessing the outcomes of interest in the review precluded subgroup analyses by relevant characteristics of the populations and the interventions under study.The quality of evidence was rated as moderate to low across the different outcomes . The maiLactobacillus rhamnosus probiotic (with and without Bifidobacterium), initiated at the beginning of the second trimester of gestation, was associated with a statistically significant reduction in the STAI-6 instrument anxiety scores prior to birth and in the postpartum period . While not statistically significant, similar trends were observed for reduced depression scores and lower likelihood of women with scores below cut-off values for clinical depression or anxiety. The review did not identify any trials evaluating the effectiveness of prebiotic or synbiotic supplementation, highlighting the need for research in these areas.This systematic review and meta-analysis identified early accumulating evidence from three RCTs, involving a total of 713 participants, on the effectiveness of probiotics administered during pregnancy in improving maternal mental health in the perinatal period. Based on 280 women from two RCTs conducted in New Zealand by Dawe et al.  and SlykThe evidence about the effectiveness of probiotics in decreasing mental health symptoms and risks in non-pregnancy populations is conflicted. Recent meta-analyses of RCTs , 23 haveThe effectiveness of probiotic intervention is based on a number of factors, such as the mode of therapy, strain of probiotic, and disease indication . The SlyLactobacillus rhamnosus  that may confound the impact of probiotic supplementation during pregnancy on mental health outcomes during and after pregnancy. However, using randomization alone to equally distribute potential confounders between the groups does not automatically protect against selection bias. As allocation concealment (which is another important pre-requisite in RCTs to prevent selection bias) was rated unclear in one of the studies , completThis systematic review did not examine potential mechanisms for the probiotic, prebiotic, or symbiotic effects on perinatal mental health symptoms; however, some modes of action investigated in preclinical studies may account for the probiotic effect of lowering anxiety and depression scores identified in this review. Rodent model studies have suggested that probiotics can reduce chronic stress markers  and attenuate hypothalamic-pituitary-adrenal (HTA) axis responses, which are hyperreactive in depressed patients . Others Strengths of our systematic review approach include the use of a comprehensive search strategy in both electronic and gray literature sources and involving of two reviewers in all stages of the review process as strategies to avoid selection bias in the review. The risk of bias and GRADE evaluations provided insightful information about the strengths and weaknesses of this body of evidence. Meta-analyses were conducted using methods that accounted for statistical and clinical heterogeneity across the studies. Our review is limited by the small number of RCTs evaluating the administration of probiotics during pregnancy to reduce mental health problems in the perinatal period and the moderate quality of the body of evidence for the outcomes evaluated in the primary studies.The use of probiotics, prebiotics and synbiotic supplementation during pregnancy is an emerging area of research. This systematic review found limited evidence about the effectiveness of probiotics administered during pregnancy to reduce the risk of maternal mental health disorders and highlighted the lack of evidence on prebiotics and synbiotics supplementation to inform their use for similar purposes. Firm clinical recommendations about the use of probiotics, prebiotics, and synbiotics to prevent the occurrence of mental health problems in the perinatal period cannot be based on the current body of evidence about their effectiveness. Finally, it is imperative that future trials of microbiota interventions test probiotic/prebiotic/synbiotic interventions that redress specific dysbioses in pregnancy gut microbiota that arise from poor mental health.The original contributions presented in the study are included in the article/MO, AK, and JW conceived and designed the study. VD, SL, OS, LD, and MO collected and analyzed the data. VD and MO drafted the manuscript. All authors approved the contents 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.


As the most widely used mammalian cell line, Chinese hamster ovary (CHO) cells can express various recombinant proteins with a post translational modification pattern similar to that of the proteins from human cells. During industrial production, cells need large amounts of ATP to support growth and protein expression, and since glycometabolism is the main source of ATP for cells, protein production partly depends on the efficiency of glycometabolism. And efficient glycometabolism allows less glucose uptake by cells, reducing production costs, and providing a better mammalian production platform for recombinant protein expression. In the present study, a series of progresses on the comprehensive optimization in CHO cells by glycometabolism strategy were reviewed, including carbohydrate intake, pyruvate metabolism and mitochondrial metabolism. We analyzed the effects of gene regulation in the upstream and downstream of the glucose metabolism pathway on cell’s growth and protein expression. And we also pointed out the latest metabolic studies that are potentially applicable on CHO cells. In the end, we elaborated the application of metabolic models in the study of CHO cell metabolism. In recent years, the proportion of biological drugs in the global pharmaceutical market has been expanding. Since 2002, more than 300 biological drugs have been approved by the FDA , and theFor macromolecular complex recombinant therapeutic proteins (RTPs), proper folding and post-translational modifications of proteins are required to meet their biological activity; therefore, mammalian cells are often used to produce RTPs. Among the mammalian cells, such as mouse myeloma cells, mouse fibroblasts, human embryonic kidney 293 cells, small hamster kidney cells, and human retina-derived PerC6 cells , ChineseSince the first RTP, tissue plasminogen activator (tPA), was approved for marketing in 1986 , CHO celTo meet the growing market demand for biopharmaceuticals, how to continuously innovate manufacturing processes to achieve higher volume productivity in shorter time, as well as stable product quality and lower production cost is a hot research topic in biopharmaceutical field nowadays. To achieve this, researchers overexpressed beneficial genes or repressed disadvantageous genes by genomic knock-out or siRNA-mediated knock-down to improve performance of CHO manufacturing cell lines. These cell engineering approaches classically focused on the cellular growth, metabolism, apoptosis, the protein glycosylation, secretion, and production . We alsoThis paper reviews the progress of research on optimizing CHO cellular glucose metabolism in three aspects: alternative carbon sources, pyruvate metabolism, and mitochondrial metabolism using gene editing techniques.2 by entering the tricarboxylic acid cycle (TCA cycle) continuously; the conversion to ribose phosphate through the pentose phosphate pathway, which is used for the generation of nucleic acid; and the synthesis to other substances such as amino acids and fatty acids.Glucose is the main component of mammalian cell culture medium and the main carbon source material that provides energy for cell growth. There are four main metabolic pathways of glucose in CHO cells: the conversion to lactic acid through the glycolytic pathway, which provides energy for cell growth; the complete oxidation to CO2 in the TCA cycle  and external  factors act together during cell lineage development, among which environmental factors include the provision of key components, such as amino acids, carbohydrates, and metabolites, which promote cell growth, prolong culture viability, and increase productivity by supporting efficient cell metabolism. However, high provision of nutrients can increase the production and accumulation of metabolic wastes, such as lactate and ammonia, inhibiting normal cellular metabolism. Moreover, very rapid glycolysis can lead to the accumulation of pyruvate, which in turn generates lactate. In addition, the production of lactate and ammonia can further lead to inefficient metabolism, resulting in reduced cell growth and protein synthesis . TherefoCHO cells cultured with galactose, instead of glucose as the sole carbon source, showed a low survival rate . In contThe affinity of fructose transporter protein (GLUT5) for fructose is lower than that of glucose transporter protein (GLUT1) for glucose. Thus, replacing glucose in the medium with fructose while CHO cells express GLUT5 can also reduce lactate accumulation by reducing the glycolytic flux . CHO celBy stably expressing both GLUT5 and pyruvate carboxylase (PYC), energy metabolism was improved, and lactate production was reduced, resulting in increased cell density and prolonged cell life span. Cellular metabolic flux analysis showed that CHO cells subjected to double gene editing had higher metabolic fluxes in glycolysis and TCA cycles, were able to consume more fructose, and maintained higher cell density .During the growth and protein expression of CHO cells, the culture medium can provide various nutrients to the cells. Among them, some carbohydrates, lipids, and amino acids can be metabolized by the cells to produce energy. These substances can be converted to each other to maintain the metabolic balance of the cells, and pyruvate plays a very important role in this conversion process. For example, the metabolism of amino acids such as alanine and glycine, lipids, such as glycerol and fatty acids, and various hexoses are all related to the metabolism of pyruvate. Especially for the TCA cycle, pyruvate is one of the most important metabolic substrates. In addition, during the production, transport, and consumption of pyruvate, the generated substances, such as nicotinamide adenine dinucleotide (NADH), are essential for the regulation of cellular metabolism and influence the efficiency of metabolism of various substances. Notably, pyruvate is also the only source of lactate, a waste product of cellular metabolism, and therefore, the study of pyruvate metabolism becomes an important part that cannot be bypassed when solving problems such as lactate production and accumulation. Since the processes of pyruvate production, transport and consumption involve multiple metabolites and key enzymes, various GOIs are available to optimize the metabolism of pyruvate.Pyruvate is the main product of the glycolytic process in CHO cells, and the concentration of intracellular pyruvate is mainly influenced by its production rate. If production rate exceeds consumption rate, a higher glycolytic flux leads to the accumulation of pyruvate. The rapid production and accumulation of pyruvate lead to the accumulation of lactate  and alanThe site of pyruvate production is primarily the cytoplasm, but its metabolism is in the mitochondrial matrix. Although pyruvate can freely cross the outer mitochondrial membrane (through pores or non-selective channels), it needs to cross the inner membrane and enter the mitochondrial matrix with the help of the mitochondrial pyruvate carrier (MPC), which participates in the TCA cycle, gluconeogenesis, and the metabolism of lipids and amino acids to provide energy to the organism . TherefoMPC are pyruvate transport proteins located on the inner mitochondrial membrane, which were identified by Papa and Halestrap  in the 1+ favor the consumption of lactate for the reverse reaction. Typically, the ratio of NAD+/NADH in the cytoplasm is ∼700:1, whereas the ratio of lactate/pyruvate is ∼20:1  complex may be inactivated by pyruvate dehydrogenase kinase (PDK) phosphorylation, resulting in the inability to metabolize pyruvate . TherefoIn a typical oxygen-depleted environment, the energy production rate of mammalian cells is approximately 2.5–4.5 pmol ATP/cell/h. Cells in the growth phase require approximately 30% more energy than in the resting phase . Aside fp ≤ 0.0001) after 48–72 h of aconitase silencing using siRNA alone, demonstrating that the downregulation of aconitase genes has the most lethal effect among TCA cycle genes. Aconitase catalyzes the reversible conversion of citric acid to cis-aconitic acid and then cis-aconitic acid to isocitric acid  in CHO cells, the researchers found that the expression of an inner mitochondrial membrane protein called Leucine Zipper and EF-Hand Containing Transmembrane Protein 1 (LETM1) improved. Therefore, LETM1 was identified as a potential target of miR-23. Meanwhile, due to the depletion of miR-23, although the growth of CHO cells was not changed, the specific productivity was increased, leading to a three-fold increase in the secreted alkaline phosphatase (SEAP) volume productivity . Furtheractivity  and incractivity .+ is important in mitochondria as a raw material for the synthesis of NADH. In mitochondrial reactions related to glucose metabolism, NAD+ is involved in the TCA cycle, oxidative phosphorylation, and oxidative respiratory chain   , which iSLC25A51 , thus suoduction  and is a content  and regun to ATP . In 2009n to ATP , and NMNn to ATP . The res in mice . This exEstablishing metabolic models of mammalian cells has been hampered by the complexity of cell structure, differences in media composition and manipulation, and parameters during culture. However, with the expansion of the coverage of histological technologies and the improvement of the reliability of histological data, in 2016, researchers were able to systematically study CHO cell metabolism for the first time, they successfully established a genome-scale CHO metabolic model, iCHO1766 . The modThe simulation scope and capability of metabolic models can limit the application of CHO cells in the industrial production of RTPs. To obtain more reliable and accurate results, metabolic models need to be updated regularly to cover the latest research advances in molecular and biochemical fields . ResearcIn the past few years, we have witnessed the progress of the CHO cells in many aspects. Among them, the importance of optimizing the CHO cell line as the host cell for protein expression cannot be overstated. Since the carbohydrate metabolism of the cells directly determines whether there is enough ATP to support cell proliferation and protein expression, the engineering of carbohydrate metabolism in CHO cells requires much deeper study. Researchers identified and overexpressed or down-expressed several key enzymes in three aspects: enabling fructose and galactose to replace glucose as the start of glycolysis; solving the problem of difficult translocation of pyruvate in the cytoplasm into the mitochondria for consumption; and increasing the efficiency of mitochondrial ATP production, which enables CHO cells to maximize energy generation with minimal carbohydrate utilization and suppress the accumulation of metabolic waste. Furthermore, the optimization of cellular metabolism is also directly reflected in the increase of protein production. However, further research is still warranted. For example, the latest metabolic studies such as NAMPT, NMNAT, and SLC25A51 have not been applied to improve protein expression, and the latest CRISPR technology still needs a breakthrough, which is expected to achieve direct mitochondrial genome editing. Big data and multi-omics technologies are also beneficial to provide new research directions and research ideas, assisting in the comprehensive analysis of the metabolic condition of the edited cells for metabolic engineering, effectively using these tools will be the key to improving the research efficiency. It should be noticed that most metabolic engineering studies are still at the basic research level, which have the potential to be applied in industrial production. And many excellent cell engineering studies have been applied to improve protein yield such as the genomic deletion/inactivation of the dihydrofolate reductase gene which paved the way for an economical utilization of CHO cells for biopharmaceutical manufacturing . Finally


Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease, exposing to the risk of liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Angio-genesis is a complex process leading to the development of new vessels from pre-existing vessels. Angiogenesis is triggered by hypoxia and inflammation and is driven by the action of proangiogenic cytokines, mainly vascular endothelial growth factor (VEGF). In this review, we focus on liver angiogenesis associated with NAFLD and analyze the evidence of liver angiogenesis in animal models of NAFLD and in NAFLD patients. We also report the data explaining the role of angiogenesis in the progression of NAFLD and discuss the potential of targeting angiogenesis, notably VEGF, to treat NAFLD. Non-alcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease worldwide . NAFLD iAngiogenesis is a complex process leading to the development of new vessels from pre-existing vessels. Angiogenesis occurs under physiological conditions during normal wound healing and also in pathological contexts, such as tumorigenesis, so that antiangiogenic molecules  monoclonal antibody) are used in the treatment of different cancers, including HCC, according to recent guidelines . MoleculAngiogenesis also takes place during chronic liver diseases. Indeed, liver fibrosis progression is accompanied by angiogenesis, regardless of the etiology of the liver disease ,5. In thIn the context of chronic liver disease, angiogenesis leads to quantitative changes of liver vessels with the emergence of new vessels but also consists in qualitative changes of vessels (both pre-existing and new vessels), resulting in a process known as vascular remodeling. Such qualitative vascular changes include dedifferentiation of liver sinusoidal endothelial cells (LSECs), also called capillarization, defined by the loss of their fenestrae and the acquisition of a basement membrane . In the This review focuses on angiogenesis associated with NAFLD. First, we report the manifestations of angiogenesis in animal models and in patients with NAFLD. Second, we address the role of angiogenesis in the progression of NAFLD. Finally, we discuss the potential of targeting angiogenesis to treat patients with NAFLD.Liver angiogenesis can be assessed either directly, typically by showing an increase in the number of hepatic vessels, or indirectly, by measuring the expression of angiogenesis markers, such as markers of endothelial cells or proangiogenic cytokines. Because indirect methods are the most easily accessible, they are commonly used, but one should keep in mind their limitations. Indeed, the expression of endothelial cell markers does not necessarily correlate with the number of endothelial cells because some endothelial markers, such as CD105, are upregulated during the activation of endothelial cells associated with angiogenesis .Many rodent models have been used to study NAFLD: each of them mimicking one or several features of human NAFLD, i.e., steatosis, NASH, fibrosis and HCC . SeveralSpecific techniques of imaging were used to analyze the global vasculature of mouse liver with NAFLD. Using scanned electronic microscopy of vascular corrosion casts of the liver, Coulon et al. showed that NAFLD was associated with a global alteration of the hepatic vascular architecture that consisted not only in an increased number of vessels but also in a clearly different phenotype of vessels, which displayed an enlarged diameter and a disrupted organization . The samCompared to studies in animal models, data related to liver angiogenesis in patients with NAFLD are more limited. We showed that the liver from patients with NAFLD displayed an increased expression of the endothelial marker, vWF especially in patients with advanced fibrosis . FurtherNAFLD patients display increased serum levels of angiogenic markers such as VEGF, soluble VEGFR-1 (sVEGFR1) and sVEGFR2 . HoweverEvidence of liver angiogenesis in animal models of NAFLD and in NAFLD patients suggests a role of liver angiogenesis in NAFLD pathogenesis. During NAFLD, angiogenesis drives inflammation and fibrosis, as reviewed elsewhere . Liver aThe molecular pathways of angiogenesis are intermingled with those of NAFLD. Proangiogenic cytokines have an impact on NAFLD. Indeed, VEGF is also involved in lipogenesis so that anti-VEGFR2 treatment can induce changes in the expression of lipogenesis genes, as shown in MCD mice . HypoxiaIncreasing evidence indicates that macrophages play a critical role in NAFLD development and progression ,33. Yet,One of the mechanisms that promote angiogenesis is the secretion of extracellular vesicles. Extracellular vesicles are submicron membrane-bound structures secreted from different cell types. They contain a wide variety of molecules and exert important functions in cell-to-cell communication . Many stCirrhosis is associated with the risk of developing HCC in all chronic liver diseases including NAFLD. However, non-cirrhotic patients with NASH have a higher risk of HCC compared to patients with other types of liver disease . HCC is Ultimately, the best way to demonstrate the role of angiogenesis in the pathogenesis of NAFLD is to assess the effect of antiangiogenic treatments in NAFLD.A few antiangiogenic molecules have been tested in animal models of NAFLD. Coulon et al. showed that treatment with anti-VEGFR2 decreased steatosis and inflammation in MCD mice diet  and reduPlacental growth factor (PlGF) is a proangiogenic cytokine associated selectively with pathological angiogenesis. A previous study has shown that inhibition of PlGF reduced angiogenesis, inflammation and fibrosis in a non-NAFLD animal model of liver disease , whereasBesides anti-VEGFR2, another antiangiogenic agent has been assessed in NASH, i.e., the peptibody L1-10 which inhibits the interaction of Ang-2 with its receptor Tie2 . AdminisThe inhibition of formation of extracellular vesicles (by genetic inhibition of caspase 3) has been shown to limit the production of hepatocyte-derived proangiogenic extracellular vesicles and to protect mice fed with MCD diet from angiogenesis and fibrosis, independent of steatosis and inflammation .The treatment of CDAA rats with angiotensin II type 1 receptor blocker has been shown to decrease neovascularization and liver fibrosis . These rOne should note that the antifibrotic effects of the antiangiogenic treatments are not specific to NAFLD and have also been reported in other models of chronic liver diseases ,52,53,54In conclusion, many studies have provided convincing evidence of early and intensive liver angiogenesis in NAFLD pathogenesis both in animal models and in patients. Angiogenesis promotes the development of NAFLD, the progression of fibrosis and the emergence of HCC. Antiangiogenic treatment can reduce NASH and prevent HCC formation in different animal models. Antiangiogenic molecules approved to treat advanced hepatocellular carcinoma, notably Bevacizumab , could h


The traditional theory of ductile fracture has limitations for predicting crack generation during a cold shell nosing process. Various damage criteria are employed to explain fracture and failure in the nose part of a cold shell. In this study, differences in microstructure among fractured materials and analysis of their surfaces indicated the occurrence of brittle fractures. The degree of “plastic deformation-induced embrittlement” (PDIE) of plastically deformable materials affects the likelihood of brittle fractures; PDIE can also decrease the strength in tension due to the Bauschinger effect. Two indicators of brittle fracture are presented, i.e., the critical value of PDIE and the allowable tensile strength (which in turn depends on the degree of PDIE or embrittlement-effective strain). When the maximum principal stress is greater than the latter and the PDIE is greater than the former, our method determines the likelihood of brittle fracture. This approach was applied to an actual cold shell nosing process, and the predictions were in good quantitative agreement with the experimental results. Crack initiation and growth have been important issues in cold metal forming for many years ,2. TradiDamage models have been successfully applied to predict tensile strength even after the fracture point ,17, as wDespite the use of various methods, chevron cracking prediction remains a problem. Most studies failed to predict V-shaped cracks, and all studies to date failed to predict the decreasing slope with the increase in radius, especially near the surface of the extrusion. In addition, the predicted radii of chevron cracks were much smaller than experimentally determined values . These oIt is often difficult to determine the reasons for fracture occurrence during cold forging, because the inherent behaviors of materials change with plastic deformation; only the mass remains unchanged. Brittle fracture of ductile materials during cold metal forming is particularly problematic. The degree of “plastic deformation-induced embrittlement” (PDIE) can be increased by embedded inclusions, such as nitrogen and hydrogen as well as detrimental metallic or non-metallic inclusions, in plastically deformable bodies. Kim et al.  investigIn cold metal forming, brittle fracture can occur during plastic deformation. Brittle fracture of initially ductile materials with moderate forgeability occurs frequently, e.g., in double cup, forward and backward extrusion. Sljapic et al.  studied The brittle facture of various materials has been studied theoretically and metallurgically. Jokl et al.  studied Here, a practical, macroscopic approach for predicting brittle fracture during cold forging of ductile materials is presented. We assumed that the degree of PDIE is isotropic, and also that fracture occurs in a plane normal to the direction of the maximum principal stress when its value exceeds the weighted tensile strength of the material embrittled by compressive plastic deformation.The microstructure of the fractured material was characterized by a typical spheroidized pearlite, as shown in To determine the causes of fracture, the materials were examined macroscopically and microscopically. The five tensile specimens shown in We analyzed the representative elongation-tensile load curve denoted by No. 2 in We simulated the same tensile test to determine the critical damage values of various damage models, based on the maximum damage calculated at the fracture point, including those of Freudenthal , McClintThe predicted critical damage values, which mean maximum damage values at the necking point at the fracture instant See a, are suWe simulated the cold shell nosing process using an elastoplastic finite element method ,38 with The predicted forming load-time curve is shown in We determined the damage values for all models and then normalized them by dividing by the critical damage. Plastic deformation of material under compression results in the loss of a great deal of tensile strength capacity because of the Bauschinger effect; the material becomes brittle to some extent, depending on the material properties and magnitude of the plastic deformation ,40. WhenIn the case of multiaxial stress and strain, we have to measure the “embrittlement-effective strain” to determine the degree of PDIE of the materials; this is done using a form of scalar function. For the three plane stress cases shown in Next, we checked the three special cases, With respect to the time parameter, the strain rate multiplied by the CSWI describes a type of compressive strain, i.e., embrittlement-effective strain, which is calculated asIn addition, we adopted another weighting function, denoted as Therefore, we evaluated the occurrence of brittle fracture when the maximum principal stress Note that the critical value of PDIE, denoted by Now, we consider the reason for 3% rate of crack occurrence. The reasons for fracture in the nose part during the single-stage cold shell nosing process were examined based on the theory of ductile fracture, using various damage models, i.e., the Freudenthal, McClintock, CL and NCL, RT, BDR, NRMQ, OSOS, CMV, RTCL, KH, BWUL and BWNL, and LH models, after tensile testing for detailed investigation of the flow stress and ductile fracture behaviors of the materials. However, the models could not predict fracture around the nose part.In this study, a practical methodology for predicting brittle fracture was presented based on the degree of PDIE of plastically deformable materials. A new concept, i.e., the CSWI, was proposed to calculate the embrittlement-effective strain, excluding the damage-effective strain from the multiaxial stress. The cumulative strain indexed by CSWI was taken to indicate the degree of PDIE, which affects the likelihood of brittle fracture of plastically deformable material, as well as the fracture stress due to the Bauschinger effect. The critical value of PDIE is a material and process parameter. Our methodology estimates the likelihood of brittle fracture only when the maximum principal stress is greater than the fracture stress, and the PDIE is greater than its critical value.Assuming that the tensile strength decreases linearly with increasing PDIE, our methodology was applied to determine the reasons for fracture in an actual cold shell nosing process. Comparison of the predicted and experimental fracture shape and position indicated good quantitative agreement. Comparison of the microstructures of the materials between the failure and success cases also supported the conclusions of this study.