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Senescent cells release a variety of cytokines, proteases, and growth factors collectively known as the senescence-associated secretory phenotype (SASP). Sustained SASP contributes to a pattern of chronic inflammation associated with aging and implicated in many age-related diseases. Here, we investigated the expression and function of the immunomodulatory cytokine BAFF (B-cell activating factor; encoded by the TNFSF13B gene), a SASP protein, in multiple senescence models. We first characterized BAFF production across different senescence paradigms, including senescent human diploid fibroblasts (WI-38, IMR-90) and monocytic leukemia cells (THP-1), and tissues of mice induced to undergo senescence. We then identified IRF1 (interferon regulatory factor 1) as a transcription factor required for promoting TNFSF13B mRNA transcription in senescence. We discovered that suppressing BAFF production decreased the senescent phenotype of both fibroblasts and monocyte-like cells, reducing IL6 secretion and SA-β-Gal staining. Importantly, however, the influence of BAFF on the senescence program was cell type-specific: in monocytes, BAFF promoted the early activation of NF-κB and general SASP secretion, while in fibroblasts, BAFF contributed to the production and function of TP53 (p53). We propose that BAFF is elevated across senescence models and is a potential target for senotherapy.

BACKGROUND: Mesenchymal stem cells are ideal candidates in regenerative medicine, and their clinical application is currently limited by reduced cell viability and poor paracrine capacity caused by changes in the transplanted microenvironment. The preconditioning strategy is believed to maximize the survival rate and biological role of mesenchymal stem cells in the transplanted microenvironment, providing new ideas and potential for the treatment of severe burn injuries. OBJECTIVE: To review the potential of mesenchymal stem cell preconditioning strategies in the treatment of severe burn injuries. METHODS: With “mesenchymal stem cells, MSCs, preconditioning, pretreatment, burn injury, severe burn injury, burn pathophysiology” as the search terms in Chinese and English, the original articles and reviews collected from January 2000 to January 2022 in CNKI database and PubMed database were searched, and screened and analyzed. Finally, 81 articles were selected for review after excluding researches that were not related to this publication, inconsistent, outdated and repetitive, and those with low credibility and poor logical rigor. RESULTS AND CONCLUSION: (1) The traditional treatment methods after severe burn injury are fluid resuscitation, airway management, infection prevention and control, organ support, early eschar decompression and eschar autograft and allograft transplantation. Clinical treatment still faces great challenges. (2) Mesenchymal stem cells have become a hot spot for treatment because of their low immunogenicity, easy access, and strong tissue repair ability. (3) Once mesenchymal stem cells are applied to burn wounds, they will face the oxidative stress environment caused by ischemia/hypoxia and increased production of reactive oxygen species, resulting in decreased cell survival rate and biological activity. (4) Strategies such as cytokine preconditioning, hypoxia preconditioning, gene modification and drug preconditioning can play a role in treating wound infection, reducing excessive inflammation, relieving hypermetabolic state, regulating immune system, promoting wound healing, and inhibiting therapeutic potential of hypertrophic scars. (5) The application of pretreatment strategies in the clinical treatment of severe burn injuries is limited due to the small number of patients with severe burns and insufficient clinical data to support them. (6) The efficacy and safety of preconditioning strategies in the treatment of severe burn injuries need to be determined through a large number of preclinical studies and clinical cases. BACKGROUND: Mesenchymal stem cells are ideal candidates in regenerative medicine, and their clinical application is currently limited by reduced cell viability and poor paracrine capacity caused by changes in the transplanted microenvironment. The preconditioning strategy is believed to maximize the survival rate and biological role of mesenchymal stem cells in the transplanted microenvironment, providing new ideas and potential for the treatment of severe burn injuries. OBJECTIVE: To review the potential of mesenchymal stem cell preconditioning strategies in the treatment of severe burn injuries. METHODS: With “mesenchymal stem cells, MSCs, preconditioning, pretreatment, burn injury, severe burn injury, burn pathophysiology” as the search terms in Chinese and English, the original articles and reviews collected from January 2000 to January 2022 in CNKI database and PubMed database were searched, and screened and analyzed. Finally, 81 articles were selected for review after excluding researches that were not related to this publication, inconsistent, outdated and repetitive, and those with low credibility and poor logical rigor. RESULTS AND CONCLUSION: (1) The traditional treatment methods after severe burn injury are fluid resuscitation, airway management, infection prevention and control, organ support, early eschar decompression and eschar autograft and allograft transplantation. Clinical treatment still faces great challenges. (2) Mesenchymal stem cells have become a hot spot for treatment because of their low immunogenicity, easy access, and strong tissue repair ability. (3) Once mesenchymal stem cells are applied to burn wounds, they will face the oxidative stress environment caused by ischemia/hypoxia and increased production of reactive oxygen species, resulting in decreased cell survival rate and biological activity. (4) Strategies such as cytokine preconditioning, hypoxia preconditioning, gene modification and drug preconditioning can play a role in treating wound infection, reducing excessive inflammation, relieving hypermetabolic state, regulating immune system, promoting wound healing, and inhibiting therapeutic potential of hypertrophic scars. (5) The application of pretreatment strategies in the clinical treatment of severe burn injuries is limited due to the small number of patients with severe burns and insufficient clinical data to support them. (6) The efficacy and safety of preconditioning strategies in the treatment of severe burn injuries need to be determined through a large number of preclinical studies and clinical cases. [ABSTRACT FROM AUTHOR]

Kidney disease (KD) is a life-threatening disease characterized by high morbidity and mortality in clinical settings, which can be caused by many reasons, and the incidence increases with age. However, supportive therapy and kidney transplantation still have limitations in alleviating KD progression. Recently, mesenchymal stem cells (MSCs) have shown great potential in repairing injury through their multidirectional differentiation and self-renewal ability. Of note, MSCs serve as a safe and effective therapeutic strategy for treating KD in preclinical and clinical trials. Functionally, MSCs ameliorate KD progression by regulating the immune response, renal tubular cell apoptosis, tubular epithelial-mesenchymal transition, oxidative stress, angiogenesis, and so on. In addition, MSCs exhibit remarkable efficacy in both acute kidney injury (AKI) and chronic kidney disease (CKD) through paracrine mechanisms. In this review, we outline the biological characteristics of MSCs, discuss the efficacy and mechanisms of MSCs-based therapy for KD, summarize the completed and ongoing clinical trials, as well as analyze limitations and new strategies, aiming to provide new ideas and approaches for the preclinical experiments and clinical trials of MSCs transplantation for KD. [ABSTRACT FROM AUTHOR]

Background: The aim is to verify the therapeutic effect and possible mechanism of human umbilical cord Wharton's jelly-derived transplantation of mesenchymal stem cells (UMSCs) on CCl4-induced hepatic fibrosis rats through in vivo studies and to explore the regulatory mechanism of UMSCs on fibrosis of hepatic stellate cells (HSCs) through in vitro experiments. Methods: In vivo experiment: Rats were randomly divided into blank control group and hepatic fibrosis group. During the entire trial, the blank control group received subcutaneous injection of normal saline, while in the hepatic fibrosis group received injections of 50% CCl4-olive oil subcutaneously for 10 weeks to establish the rat model of liver fibrosis. Hepatic fibrosis rats were then randomly and evenly divided into umbilical cord mesenchymal stem cell (UMSC) group, bone marrow mesenchymal stem cell (BMSC) group, UMSC-culture medium (CM) group, and control group. Rats in each group were infused with the following substances through the caudal vein as follows: 1 mL UMSCs (2 × 106/mL) in UMSC group, 1 mL BMSCs (2 × 106/mL) in BMSC group, 1 mL UMSCs-CM in CM group, and 1 mL saline in control group. Rats of each group were closely observed (weight, hair condition, activity, appetite, diarrhea, etc.), venous blood samples were collected, the number of white blood cells and lymphocytes were measured, and liver function indicators (ALT, AST, TBIL, ALB) were determined. Three weeks later, rat liver specimens were taken, HE stained, pathological changes were examined and quantified. In vitro experiments: HSCs were seeded in 6-well plates at 1.0 × 105/mL, with a serum-free medium for 24 hours. Then, 2 mL of UMSCs-CM was added in the study group, while an equal amount of complete medium was added to the control group. RT-PCR was used to detect TGF-β1, Collagen-I, TIMP-2 mRNA expression in HSCs, and western blot was used to detect TGF-β1 protein expression in HSCs. Results: In vivo experiment: Compared with the control group, after the transplantation, the activity status (weight, spirit, appetite, movement, hair, diarrhea, etc.) of rats in the UMSC group, BMSC group, and CM group were improved. The liver function indexes of these groups, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) were significantly decreased (p < 0.05), while albumin (ALB) levels were mildly but not significantly increased (p > 0.05). The Knodell score (reflecting the degree of liver inflammation) and Chevallier score (reflecting the degree of liver fibrosis) of liver specimens in pathological examination were also significantly reduced, and the difference in the quantitative scores of those indexes was statistically significant (p < 0.05). There was no statistically significant difference in the number of venous white blood cells and lymphocytes, liver function indexes (ALT, AST, TBIL, ALB), Knodell score, and Chevallier score of liver samples among the UMSC group, BMSC group, and CM group. In vitro experiments: After treatment with UMSCs-CM, the expression of TGF-β1, Collagen-I, and TIMP-2 mRNA in HSCs was significantly down-regulated compared with that of the control group (treated with complete medium), and it gradually decreased with the extension of the treatment time. Compared with the control group, the expression of TGF-β1 protein in the HSCs of the experimental group was down-regulated, and this effect was time-dependent, specifically, the control group (2.49 ± 0.43) > the experimental group at 48 hours (1.98 ± 0.26) > the experimental group at 72 hours (1.62 ± 0.20) (F = 7.796, p < 0.05). Conclusions: In rats with liver fibrosis, transplantation of UMSCs can improve liver function and reduce the inflammatory activity and fibrosis of the liver, possibly through the paracrine mechanism. UMSCs inhibit HSCs fibrosis through a paracrine mechanism, which is time-dependent, possibly by targeting TGF-β1 and its downstream gene products. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cell (MSC) therapy has gained significant traction in the context of cardiovascular repair, and have been proposed to exert their regenerative effects via the secretion of paracrine factors. In this systematic review, we examined the literature and consolidated available evidence for the "paracrine hypothesis". Two Ovid SP databases were searched using a strategy encompassing paracrine mediated MSC therapy in the context of ischemic heart disease. This yielded 86 articles which met the selection criteria for inclusion in this study. We found that the MSCs utilized in these articles were primarily derived from bone marrow, cardiac tissue, and adipose tissue. We identified 234 individual protective factors across these studies, including VEGF, HGF, and FGF2; which are proposed to exert their effects in a paracrine manner. The data collated in this systematic review identifies secreted paracrine factors that could decrease apoptosis, and increase angiogenesis, cell proliferation, and cell viability. These included studies have also demonstrated that the administration of MSCs and indirectly, their secreted factors can reduce infarct size, and improve left ventricular ejection fraction, contractility, compliance, and vessel density. Furthering our understanding of the way these factors mediate repair could lead to the identification of therapeutic targets for cardiac regeneration. [ABSTRACT FROM AUTHOR]

Stem cells in the anterior pituitary gland can give rise to all resident endocrine cells and are integral components for the appropriate development and subsequent maintenance of the organ. Located in discreet niches within the gland, stem cells are involved in bi-directional signalling with their surrounding neighbours, interactions which underpin pituitary gland homeostasis and response to organ challenge or physiological demand. In this review we highlight core signalling pathways that steer pituitary progenitors towards specific endocrine fate decisions throughout development. We further elaborate on those which are conserved in the stem cell niche postnatally, including WNT, YAP/TAZ and Notch signalling. Furthermore, we have collated a directory of single cell RNA sequencing studies carried out on pituitaries across multiple organisms, which have the potential to provide a vast database to study stem cell niche components in an unbiased manner. Reviewing published data, we highlight that stem cells are one of the main signalling hubs within the anterior pituitary. In future, coupling single cell sequencing approaches with genetic manipulation tools in vivo, will enable elucidation of how previously understudied signalling pathways function within the anterior pituitary stem cell niche. [ABSTRACT FROM AUTHOR]

Sepsis, a life-threatening condition resulting in multiple organ dysfunction, is characterized by a dysregulated immune response to infection. Current treatment options are limited, leading to unsatisfactory outcomes for septic patients. Here, we present a series of studies utilizing compact bone mesenchymal stem cells (CB-MSCs) and their derived paracrine mediators, especially exosome (CB-MSCs-Exo), to treat mice with cecal ligation and puncture-induced sepsis. Our results demonstrate that CB-MSCs treatment significantly improves the survival rate of septic mice by mitigating excessive inflammatory response and attenuating sepsis-induced organ injuries. Furthermore, CB-MSCs-conditioned medium, CB-MSCs secretome (CB-MSCs-Sec), and CB-MSCs-Exo exhibit potent anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated murine macrophage (RAW264.7). Intriguingly, intravenous administration of CB-MSCs-Exo confers superior protection against inflammation and organ damage in septic mice compared to CB-MSCs in certain aspects. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS) shotgun proteomic analysis, we identify a range of characterized proteins derived from the paracrine activity of CB-MSCs, involved in critical biological processes such as immunomodulation and apoptosis. Our findings highlight that the paracrine products of CB-MSCs could serve as a promising cell-free therapeutic agent for sepsis. • CB-MSCs possess the potential to mitigate the severity of organ damage and reduce mortality in septic mice. • CB-MSC-Exo retains therapeutic potency akin to their parent cells, and the direct intravascular injection of CB-MSCs-Exo is feasible and safe, supporting further evolution for clinical applications. • The global characterization of the proteome and functional analyses suggest that proteins related to the immune system and inflammation-processes are enriched in CB-MSCs paracrine products, and some specific proteins (prohibitin, SLC25A5, and gelsolin) are enriched in CB-MSCs-Exo, revealing the excellent potential of these proteins in the regulation of sepsis. • The paracrine products of CB-MSCs can serve as a promising cell-free therapeutic agent for sepsis. [ABSTRACT FROM AUTHOR]

The combination of hyaluronic acid (HA) and BMP-2 has been reported to promote bone regeneration. However, the interaction of endothelial cells and bone marrow mesenchymal stem cells (BMSCs) during HA + BMP-2 treatment is not fully understood. This study aimed to analyze the direct effect of HA, as well as the paracrine effect of HA-treated endothelial cells, on the BMP-2-mediated osteogenic differentiation of BMSCs. The angiogenic differentiation potential of HA at different molecular weights and different concentrations was tested. The direct effect of HA, as well as the indirect effect of HA-treated human umbilical cord endothelial cells (HUVECs, i.e., conditioned medium (CM)-based co-culture) on the BMP-2-mediated osteogenic differentiation of BMSCs was analyzed using alkaline phosphatase (ALP) staining and activity, alizarin red S (ARS) staining, and RT-qPCR of osteogenic markers. Angiogenic differentiation markers were also analyzed in HUVECs after treatment with HA + BMP-2. The bone regeneration potential of BMP-2 and HA + BMP-2 was analyzed in a rat ectopic model. We found that 1600 kDa HA at 300 µg/mL promoted tube formation by HUVECs in vitro and upregulated the mRNA expression of the angiogenic markers CD31, VEGF, and bFGF. HA inhibited, but conditioned medium from HA-treated HUVECs promoted, the BMP-2-mediated osteogenic differentiation of BMSCs, as indicated by the results of ALP staining and activity, ARS staining, and the mRNA expression of the osteogenic markers RUNX-2, ALP, COLI, and OPN. HA + BMP-2 (50 ng/mL) upregulated the expression of the angiogenesis-related genes VEGF and bFGF in HUVECs and bone regeneration in vivo compared to BMP-2 treatment. In conclusion, the paracrine effect of hyaluronic acid-treated endothelial cells promotes BMP-2-mediated osteogenesis, suggesting the application potential of HA + BMP-2 in bone tissue engineering.

Abstract Background Declining ovarian function in advance-aged women and in premature ovarian insufficiency (POI) patients seriously affects quality of life, and there is currently no effective treatment to rescue ovarian function in clinic. Stem cell transplantation is a promising therapeutic strategy for ovarian aging, but its clinical application is limited due to the low efficiency and unclear mechanism. Here, a novel combination of umbilical cord-mesenchymal stem cells (UC-MSCs) and autocrosslinked hyaluronic acid (HA) gel is explored to rescue ovarian reserve and fecundity in POI and naturally aging mice. Methods To investigate HA prolonged the survival after UC-MSCs transplantation, PCR and immunofluorescence were performed to track the cells on day 1, 3, 7 and 14 after transplantation. The effects of HA on UC-MSCs were analyzed by CCK8 assay, RNA-sequencing and 440 cytokine array. In vivo experiments were conducted to evaluate the therapeutic effects of UC-MSCs combined with HA transplantation in 4-vinylcyclohexene diepoxide (VCD)-induced POI mice and naturally aging mice model. Ovarian function was analyzed by ovarian morphology, follicle counts, estrous cycle, hormone levels and fertility ability. To investigate the mechanisms of stem cell therapy, conditioned medium was collected from UC-MSCs and fibroblast. Both in vitro ovarian culture model and 440 cytokine array were applied to assess the paracrine effect and determine the underlying mechanism. Hepatocyte growth factor (HGF) was identified as an effective factor and verified by HGF cytokine/neutralization antibody supplementation into ovarian culture system. Results HA not only prolongs the retention of UC-MSCs in the ovary, but also boosts their secretory function, and UC-MSCs promote follicular survival by activating the PI3K-AKT pathway through a paracrine mechanism both in vitro and in vivo. More importantly, HGF is identified as the key functional cytokine secreted by MSCs. Conclusions The results show that HA is an excellent cell scaffold to improve the treatment efficiency of UC-MSCs for ovarian aging under both physiological and pathological conditions, and the therapeutic mechanism is through activation of the PI3K-AKT pathway via HGF. These findings will facilitate the clinical application of MSCs transplantation for ovarian disorders.

The interaction between electrospinning nanomaterials and stem cells to repair damaged tissue mainly focus on manipulating cell viability, proliferation, or paracrine by the materials and their specific topology. In particular, the paracrine products of stem cells influence the behavior of those repairable cells (i.e., epidermal cells, fibroblasts, and endothelial cells) to speed up the repair progress. In this study, a series of nanofiber-based meshes were fabricated by electrospinning and light-welding technology to investigate their impacts on the paracrine behaviors of adipose stem cells (ADSCs) and their performance in accelerating wound healing. We found that the nanofiber-based meshes with varied grid sizes and modified with gelatin nanofibers could regulate the paracrine of ADSCs. As a result, the migration of fibroblasts and endothelial cells as well as angiogenesis was all influenced in vitro. In vivo investigation using rat skin wound healing models also indicated that the nanofiber-based meshes could accelerate wound healing rate, increase the thickness of the regenerated epidermis, and promote type I collagen production and CD31-positive vessel formation in the dermis layer. Taken together, such nanofiber-based meshes provide effective and promising alternatives to design tissue-repair scaffolds involving manipulating stem cell paracrine and wound closure.

Treatment of myocardial infarction (MI) with bone marrow cells (BMCs) improves post-MI cardiac function in rodents. However, clinical trials of BMC therapy have been less effective. While most rodent experiments use young healthy donors, patients undergoing autologous cell therapy are older and post-MI. We previously demonstrated that BMCs from aged and post-MI donor mice are therapeutically impaired, and that donor MI induces inflammatory changes in BMC composition including reduced levels of B lymphocytes. Here, we hypothesized that B cell alterations in bone marrow account for the reduced therapeutic potential of post-MI and aged donor BMCs. Injection of BMCs from increasingly aged donor mice resulted in progressively poorer cardiac function and larger infarct size. Flow cytometry revealed fewer B cells in aged donor bone marrow. Therapeutic efficacy of young healthy donor BMCs was reduced by depletion of B cells. Implantation of intact or lysed B cells improved cardiac function, whereas intact or lysed T cells provided only minor benefit. We conclude that B cells play an important paracrine role in effective BMC therapy for MI. Reduction of bone marrow B cells because of age or MI may partially explain why clinical autologous cell therapy has not matched the success of rodent experiments.

Abstract Telocytes (TCs) are a type of interstitial cells with essential roles in regenerative medicine. TCs spatially exist in the stem cell niche and are considered a ‘stem cell helper cell’. Mesenchymal stromal cells therapy has been widely used in treating lung diseases, while there is increasing evidence from preclinical studies to show the beneficial effects of TCs to support smooth muscle cells and treat lung diseases, by releasing paracrine factors, exosomes, and microvesicles. There are still limitations and challenges to be overcome for TCs‐based translational medicine and clinical applications, by developing new methods and improving therapeutic strategies. The present review overviews the historical development, morphology and spatialization, biomarker specificity and values, biological functions, therapeutic effects on preclinical lung diseases, as well as potential mechanisms and future perspectives in lung diseases. TCs exert beneficial effects on preclinical asthma and acute lung injury and essential roles in repairing injured lung tissues and angiogenesis, by releasing paracrine factors and exosomes.

Background: Knee Osteoarthritis (kOA), the most common joint degenerative disorder, lacks effective therapeutics. Placenta-derived mesenchymal stromal cells (PMSCs) are effective in tissue repairing and generation, which have potential in treating kOA. This study aimed to determine the anti-kOA efficacy of PMSCs and to explore its action mode. Methods: Flow cytometry and three-line differentiation were performed for identification of PMSCs. In vivo, a rat kOA model established by anterior cruciate ligament transection (ACLT) surgery was used to evaluate the efficacy of PMSCs. Histopathological HE and SO staining with Osteoarthritis Research Society International scoring were conducted, and cartilage expressions of MMP13 and Col2 were measured by immunohistochemistry. Pain behavior parameters by mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL), were measured. In vitro, wound healing and cell immunofluorescence assays were conducted to detect the proliferation and migration ability of chondrocytes treated with PMSCs conditioned medium (PMSCs-CM). Quantitative real-time PCR (qRT-PCR) and Western blot (WB) assays were applied to explore the molecular action of PMSCs on chondrocytes. Results: The results of flow cytometry indicated that the surface markers of PMSCs (CD73 > 95%, CD90 > 95%, and CD34 < 2%) were consistent with the typical mesenchymal stromal cells. The in vivo data showed that PMSCs significantly reversed the kOA progression by protection of cartilage, regulation of anabolic (Col2) and catabolic (MMP13) expressions, and relief of pain symptoms. The in vitro data showed that PMSCs promoted chondrocyte proliferation and migration and significantly restored the IL-1β-induced abnormal gene expressions of Col2, Mmp13, Adamts4, Adamts5 and Sox9 and also restored the abnormal protein expressions of Col2, Mmp13 and Sox9 of chondrocytes. The molecular actions of PMSCs on chondrocytes in nested co-culture way or in conditioned medium way were similar, confirming a paracrine-based mode of action. Conclusion: This study demonstrated PMSCs’ anti-kOA efficacy and its paracrine-based action mode, providing novel knowledge of PMSCs and suggesting it as a promising cell therapy for treatment of kOA. [ABSTRACT FROM AUTHOR]

Prostate cancer is a common malignancy affecting men worldwide. While the vast majority of newly diagnosed prostate cancers are categorized as adenocarcinomas, a spectrum of uncommon tumor types occur including those with small cell and neuroendocrine cell features. Benign neuroendocrine cells exist in the normal prostate microenvironment, and these cells may give rise to primary neuroendocrine carcinomas. However, the more common development of neuroendocrine prostate cancer is observed after therapeutics designed to repress the signaling program regulated by the androgen receptor which is active in the majority of localized and metastatic adenocarcinomas. Neuroendocrine tumors are identified through immunohistochemical staining for common markers including chromogranin A/B, synaptophysin and neuron specific enolase (NSE). These markers are also common to neuroendocrine tumors that arise in other tissues and organs such as the gastrointestinal tract, pancreas, lung and skin. Notably, neuroendocrine prostate cancer shares biochemical features with nerve cells, particularly functions involving the secretion of a variety of peptides and proteins. These secreted factors have the potential to exert local paracrine effects, and distant endocrine effects that may modulate tumor progression, invasion, and resistance to therapy. This review discusses the spectrum of factors derived from neuroendocrine prostate cancers and their potential to influence the pathophysiology of localized and metastatic prostate cancer. [ABSTRACT FROM AUTHOR]

It has been known that senescence-associated secretory phenotype (SASP) triggers senescence of the surrounding normal cells. However, SASP signaling regarding mesenchymal stromal cell aging remains to be fully elucidated. Therefore, the present study aimed to clarify the molecular mechanism of late (passage) MSC-induced paracrine SASP-mediated senescence of early (passage) MSCs during ex vivo expansion. Here, we conducted an extensive characterization of senescence features in bone-marrow (BM)-derived MSCs from healthy human donors. Late MSCs displayed an enlarged senescent-like morphology, induced SASP-related proinflammatory cytokines (IL-1α and IL-8), and reduced clonogenic capacity and osteogenic differentiation when compared to early MSCs. Of note, paracrine effects of SASP-related IL-1α and IL-8 from late MSCs induced cellular senescence of early MSCs via an NF-κB-dependent manner. Moreover, cellular senescence of early MSCs was promoted by the synergistic action of IL-1α and IL-8. However, inhibition of NF-κB by shRNA transfection or using inhibitors in early MSCs blocked early MSCs cellular senescence caused by paracrine SASP of late MSCs. In conclusion, these findings reveal that late MSCs display features of senescence and that, during ex vivo expansion, SASP-related proinflammatory cytokines contribute to activate a cellular senescence program in early MSCs that may ultimately impair their functionality. [ABSTRACT FROM AUTHOR]

The vertebrate nonapeptide families arginine vasopressin (AVP) and oxytocin (OXT) are considered to have evolved from a single vasopressin-like peptide present in invertebrates and termed arginine vasotocin in early vertebrate evolution. Unprecedented genome sequence availability has more recently allowed new insight into the evolution of nonapeptides and especially their receptor families in the context of whole genome duplications. In bony fish, nonapeptide homologues of AVP termed arginine vasotocin (Avp) and an OXT family peptide (Oxt) originally termed isotocin have been characterized. While reproductive roles of both nonapeptide families have historically been studied in several vertebrates, their roles in teleost reproduction remain much less understood. Taking advantage of novel genome resources and associated technological advances such as genetic modifications in fish models, we here critically review the current state of knowledge regarding the roles of nonapeptide systems in teleost reproduction. We further discuss sources of plasticity of the conserved nonapeptide systems in the context of diverse reproductive phenotypes observed in teleost fishes. Given the dual roles of preoptic area (POA) synthesized Avp and Oxt as neuromodulators and endocrine/paracrine factors, we focus on known roles of both peptides on reproductive behaviour and the regulation of the hypothalamic-pituitarygonadal axis. Emphasis is placed on the identification of a gonadal nonapeptide system that plays critical roles in both steroidogenesis and gamete maturation. We conclude by highlighting key research gaps including a call for translational studies linking new mechanistic understanding of nonapeptide regulated physiology in the context of aquaculture, conservation biology and ecotoxicology. [ABSTRACT FROM AUTHOR]

Simple Summary: The tumor microenvironment has risen over the last years as a significant contributor to the failure of antitumoral strategies due to its numerous pro-tumorigenic activities. In this review, we focused on two features of this microenvironment, namely angiogenesis and immunity, which have been the targets of therapies to tackle tumors via its microenvironmental part over the last decade. Increasing our knowledge of the complex interactions within this ecosystem is mandatory to optimize these therapeutic approaches. The development of innovative experimental models is of great help in reaching this goal. Cancer progression occurs in concomitance with a profound remodeling of the cellular microenvironment. Far from being a mere passive event, the re-orchestration of interactions between the various cell types surrounding tumors highly contributes to the progression of the latter. Tumors notably recruit and stimulate the sprouting of new blood vessels through a process called neo-angiogenesis. Beyond helping the tumor cope with an increased metabolic demand associated with rapid growth, this also controls the metastatic dissemination of cancer cells and the infiltration of immune cells in the tumor microenvironment. To decipher this critical interplay for the clinical progression of tumors, the research community has developed several valuable models in the last decades. This review offers an overview of the various instrumental solutions currently available, including microfluidic chips, co-culture models, and the recent rise of organoids. We highlight the advantages of each technique and the specific questions they can address to better understand the tumor immuno-angiogenic ecosystem. Finally, we discuss this development field's fundamental and applied perspectives. [ABSTRACT FROM AUTHOR]

Background: Adipose-derived stem cells (ADSCs) have provided promising applications for Crohn's disease (CD). However, the practical efficacy of ADSCs remains controversial, and their mechanism is still unclear. Based on the pathogenesis of dysregulated immune responses and abnormal lymphatic alterations in CD, vascular endothelial growth factor-C (VEGF-C) is thought to be a favourable growth factor to optimize ADSCs. We aimed to investigate the efficacy of VEGF-C-stimulated ADSCs and their dual mechanisms in both inhibiting inflammation "IN" and promoting inflammation "OUT" in the intestine. Methods: Human stem cells isolated from adipose tissues were identified, pretreated with or without 100 ng/ml VEGF-C and analysed for the secretion of cell culture supernatants in vitro. Lymphatic endothelial cells (LECs) were treated with ADSCs-conditioned medium or co-cultured with ADSCs and VEGF-C stimulated ADSCs. Changes in LECs transmigration, and VEGF-C/VEGFR-3 mRNA levels were assessed by transwell chamber assay and qRT–PCR. ADSCs and VEGF-C-stimulated ADSCs were intraperitoneally injected into mice with TNBS-induced chronic colitis. ADSCs homing and lymphatic vessel density (LVD) were evaluated by immunofluorescence staining. Lymphatic drainage was assessed using Evans blue. Cytokines and growth factors expression was detected respectively by ELISA and qRT–PCR. The protein levels of VEGF-C/VEGFR-3-mediated downstream signals and the NF-κB pathway were assayed by western blot. Faecal microbiota was measured by 16S rRNA sequencing. Results: ADSCs stimulated with VEGF-C released higher levels of growth factors (VEGF-C, TGF-β1, and FGF-2) and lower expression of cytokines (IFN-γ and IL-6) in cell supernatants than ADSCs in vitro (all P < 0.05). Secretome released by VEGF-C stimulated ADSCs exhibited a stronger LEC migratory capability and led to elevated VEGF-C/VEGFR-3 expression, but these effects were markedly attenuated by VEGFR-3 inhibitor. VEGF-C-stimulated ADSCs homing to the inflamed colon and mesenteric lymph nodes (MLNs) can exert stronger efficacy in improving colitis symptoms, reducing inflammatory cell infiltration, and significantly enhancing lymphatic drainage. The mRNA levels and protein concentrations of anti-inflammatory cytokines and growth factors were markedly increased with decreased proinflammatory cytokines in the mice treated with VEGF-C-stimulated ADSCs. Systemic administration of VEGF-C-stimulated ADSCs upregulated the colonic VEGF-C/VEGFR-3 pathway and activated downstream AKT and ERK phosphorylation signalling, accompanied by decreased NF-κB p65 expression. A higher abundance of faecal p-Bacteroidetes and lower p-Firmicutes were detected in mice treated with VEGF-C-stimulated ADSCs (all P < 0.05). Conclusion: VEGF-C-stimulated ADSCs improve chronic intestinal inflammation by promoting lymphatic drainage and enhancing paracrine signalling via activation of VEGF-C/VEGFR-3-mediated signalling and inhibition of the NF-κB pathway. Our study may provide a new insight into optimizing ADSCs treatment and investigating potential mechanisms in CD. [ABSTRACT FROM AUTHOR]

Background and Aims: Therapy failure in patients with metastatic colorectal cancer (mCRC, ∼80% occur in the liver) remains an overarching challenge. Preclinical studies demonstrated that HER3 promotes CRC cell survival, but therapies blocking the neuregulin-induced canonical HER3 signaling have made little impact in the clinic. Recent studies suggest that the liver microenvironment promotes CRC growth by activating HER3 in a neuregulin-independent fashion, thus elucidation of these mechanisms may reveal new strategies for treating patients with mCRC., Methods: Patient-derived primary liver endothelial cells (ECs) were used to interrogate EC-CRC crosstalk. We conducted proteomic analysis to identify EC-secreted factor(s) that triggers non-canonical HER3 activation in CRC, and determined the subsequent effects on mCRC using diverse murine mCRC models. In vitro studies with genetic and pharmacological interventions were used to map the non-canonical HER3 pathway., Results: We demonstrated that EC-secreted leucine-rich alpha-2-glycoprotein 1 (LRG1) directly binds and activates HER3 and promotes CRC growth distinct from neuregulin, the canonical HER3 ligand. Blocking host-derived LRG1 by gene knockout or a neutralizing antibody impaired mCRC outgrowth in the liver and prolonged mouse survival. We identified protein synthesis activated by the PI3K-PDK1-RSK-eIF4B axis as the biologically relevant signaling cascade downstream of the LRG1-HER3 interaction, which was not blocked by conventional HER3-specific antibodies that failed in prior clinical trials., Conclusions: LRG1 is a novel HER3 ligand and mediates liver-mCRC crosstalk. The LRG1-HER3 signaling axis is distinct from canonical HER3 signaling and represents a new therapeutic opportunity to treat patients with mCRC, and potentially other types of liver metastases., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Fam3a has been demonstrated to regulate pancreatic β-cell function and glucose homeostasis. However, the role and mechanism of Fam3a in regulating α-cell function remain unexplored., Methods: Glucagon and glucagon-like peptide-1 (GLP-1) levels in pancreas and plasma were measured in global Fam3a knockout (Fam3a -/- ) mice. Human islet single-cell RNA sequencing (scRNA-seq) datasets were utilized to analyze gene expression correlations between FAM3A and PCSK1 (encoding PC1/3, which processes proglucagon into GLP-1). Mouse pancreatic α-cell line αTC1.9 cells were transfected with Fam3a siRNA or plasmid for Fam3a knockdown or overexpression to explore the effects of Fam3a on PC1/3 expression and GLP-1 production. The downstream mediator (including Nr4a2) was identified by transcriptomic analysis, and its role was confirmed by Fam3a knockdown or overexpression in αTC1.9 cells. Based on the interacted protein of Nr4a2 and the direct binding to Pcsk1 promoter, the transcription factor Foxa2 was selected for further verification. Nuclear translocation assay and dual-luciferase reporter assay were used to clarify the involvement of Fam3a-Nr4a2-Foxa2 pathway in PC1/3 expression and GLP-1 production. Moreover, α-cell-specific Fam3a knockout (Fam3a α-/- ) mice were constructed to evaluate the metabolic variables and hormone levels under normoglycemic, high-fat diet (HFD)-fed and streptozotocin (STZ)-induced diabetic conditions. Exendin 9-39 (Ex9), a GLP-1 receptor antagonist, was used to investigate GLP-1 paracrine effects in Fam3a α-/- mice and in their primary islets., Results: Compared with wild-type mice, pancreatic and plasma active GLP-1 levels were increased in Fam3a -/- mice. Analysis of human islet scRNA-seq datasets showed a significant negative correction between FAM3A and PCSK1 in α-cells. Fam3a knockdown upregulated PC1/3 expression and GLP-1 production in αTC1.9 cells, while Fam3a overexpression displayed inverse effects. Transcriptomic analysis identified Nr4a2 as a key downstream mediator of Fam3a, and Nr4a2 expression in αTC1.9 cells was downregulated and upregulated by Fam3a knockdown and overexpression, respectively. Nr4a2 silencing increased PC1/3 expression, albeit Nr4a2 did not directly bind to Pcsk1 promoter. Instead, Nr4a2 formed a complex with Foxa2 to facilitate Fam3a-mediated Foxa2 nuclear translocation. Foxa2 negatively regulated PC1/3 expression and GLP-1 production. Besides, Foxa2 inhibited the transcriptional activity of Pcsk1 promoter at specific binding sites 10 and 6, and this inhibition was intensified by Nr4a2 in αTC1.9 cells. Compared with Flox/cre littermates, improved glucose tolerance, increased active GLP-1 level in pancreas and plasma, upregulated plasma insulin level in response to glucose, and decreased plasma glucagon level were observed in Fam3a α-/- mice. Primary islets isolated from Fam3a α-/- mice also showed an increase in active GLP-1 and insulin release. In addition, the insulinotropic effect of intra-islet GLP-1 was blocked by Ex9 in Fam3a α-/- mice and in their primary islets. Similarly, HFD-fed Fam3a α-/- mice also exhibited an improved glucose tolerance. Both HFD-fed and STZ-induced diabetic Fam3a α-/- mice showed an increased pancreatic active GLP-1 level, an elevated plasma insulin level and a reduced plasma glucagon level., Conclusions: Fam3a deficiency in α-cells enhances pancreatic GLP-1 production to improve β-cell function via paracrine signaling in an Nr4a2-Foxa2-PC1/3-dependent manner. Our study unveils a novel strategy for reprogramming α-cell proglucagon processing output from glucagon to GLP-1 and deepen the understanding of crosstalk between α-cells and β-cells., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Cardiopoiesis-primed human stem cells exert sustained benefit in treating heart failure despite limited retention following myocardial delivery. To assess potential paracrine contribution, the secretome of cardiopoiesis conditioned versus naïve human mesenchymal stromal cells was decoded by directed proteomics augmented with machine learning and systems interrogation. Cardiopoiesis doubled cellular protein output generating a distinct secretome that segregated the conditioned state. Altering the expression of 1035 secreted proteins, cardiopoiesis reshaped the secretome across functional classes. The resolved differential cardiopoietic secretome was enriched in mesoderm development and cardiac progenitor signaling processes, yielding a cardiovasculogenic profile bolstered by upregulated cardiogenic proteins. In tandem, cardiopoiesis enhanced the secretion of immunomodulatory proteins associated with cytokine signaling, leukocyte migration, and chemotaxis. Network analysis integrated the differential secretome within an interactome of 1745 molecules featuring prioritized regenerative processes. Secretome contribution to the repair signature of cardiopoietic cell-treated infarcted hearts was assessed in a murine coronary ligation model. Intramyocardial delivery of cardiopoietic cells improved the performance of failing hearts, with undirected proteomics revealing 50 myocardial proteins responsive to cell therapy. Pathway analysis linked the secretome to cardiac proteome remodeling, pinpointing 17 cardiopoiesis-upregulated secretome proteins directly upstream of 44% of the cell therapy-responsive cardiac proteome. Knockout, in silico, of this 22-protein secretome-dependent myocardial ensemble eliminated indices of the repair signature. Accordingly, in vivo, cell therapy rendered the secretome-dependent myocardial proteome of an infarcted heart indiscernible from healthy counterparts. Thus, the secretagogue effect of cardiopoiesis transforms the human stem cell secretome, endows regenerative competency, and upregulates candidate paracrine effectors of cell therapy-mediated molecular restitution., (© The Author(s) 2024. Published by Oxford University Press.)

The Conical 9 well dish (C9 well dish) is characterized by a decreasing cross-sectional area towards the base. This design was hypothesized to enhance embryonic development by emulating the in vivo physical environment through density modulation. Comparative analyses revealed no significant difference in nuclear maturation rates between the C9 well dish and the 5-well dish. Reactive oxygen species (ROS) generation was lower in the C9 well dish compared to the 5-well dish; however, this difference was not statistically significant. On the second day of in vitro culture, the cleavage rate in the C9 well dish was 4.66% higher, although not statistically significant, and the rates of blastocyst development were similar across both dishes. No significant differences were observed in the intracellular levels of glutathione (GSH) and ROS, as well as in the total cell number within the blastocysts between the dish types. The expression of mitogen-related factors, TGFα and IGF-1, in the blastocysts was consistent between the dishes. However, PDGFβ expression was significantly lower in the C9 well dish compared to the 35 mm petri dish. Similarly, the expression of the apoptosis factor Bax/Bcl2l2 showed no significant differences between the two dishes. Despite the marked difference in PDGFβ expression, its impact on blastocyst formation appeared negligible. The study also confirmed the feasibility of culturing a small number of oocytes per donor, collected via Ovum Pick-Up (OPU), with reduced volumes of culture medium and mineral oil, thus offering economic advantages. In conclusion, the present study indicates that the C9 well dish is effective for in vitro development of a small quantity of oocytes and embryos, presenting it as a viable alternative to traditional cell culture dishes., Competing Interests: No potential conflict of interest relevant to this article was reported., (© Copyright 2024 Korean Society of Animal Science and Technology.)

Prostate cancer is a common malignancy affecting men worldwide. While the vast majority of newly diagnosed prostate cancers are categorized as adenocarcinomas, a spectrum of uncommon tumor types occur including those with small cell and neuroendocrine cell features. Benign neuroendocrine cells exist in the normal prostate microenvironment, and these cells may give rise to primary neuroendocrine carcinomas. However, the more common development of neuroendocrine prostate cancer is observed after therapeutics designed to repress the signaling program regulated by the androgen receptor which is active in the majority of localized and metastatic adenocarcinomas. Neuroendocrine tumors are identified through immunohistochemical staining for common markers including chromogranin A/B, synaptophysin and neuron specific enolase (NSE). These markers are also common to neuroendocrine tumors that arise in other tissues and organs such as the gastrointestinal tract, pancreas, lung and skin. Notably, neuroendocrine prostate cancer shares biochemical features with nerve cells, particularly functions involving the secretion of a variety of peptides and proteins. These secreted factors have the potential to exert local paracrine effects, and distant endocrine effects that may modulate tumor progression, invasion, and resistance to therapy. This review discusses the spectrum of factors derived from neuroendocrine prostate cancers and their potential to influence the pathophysiology of localized and metastatic prostate cancer.

Skin tissue regeneration and repair is a complex process involving multiple cell types, and current therapies are limited to promoting skin wound healing. Mesenchymal stromal cells (MSCs) have been proven to enhance skin tissue repair through their multidifferentiation and paracrine effects. However, there are still difficulties, such as the limited proliferative potential and the biological processes that need to be strengthened for MSCs in wound healing. Recently, three-dimensional (3D) bioprinting has been applied as a promising technology for tissue regeneration. 3D-bioprinted MSCs could maintain a better cell ability for proliferation and expression of biological factors to promote skin wound healing. It has been reported that 3D-bioprinted MSCs could enhance skin tissue repair through anti-inflammatory, cell proliferation and migration, angiogenesis, and extracellular matrix remodeling. In this review, we will discuss the progress on the effect of MSCs and 3D bioprinting on the treatment of skin tissue regeneration, as well as the perspective and limitations of current research.

Background: Small intestinal ischemia-reperfusion (IR) injury is a common intestinal disease with high morbidity and mortality. Mesenchymal stem cells (MSCs) have been increasingly used in various intestinal diseases. This study aimed to evaluate the therapeutic effect of hair follicle MSCs (HFMSCs) on small intestinal IR injury.Methods: We divided Sprague–Dawley rats into three groups: the sham group, IR group and IR + HFMSCs group. A small intestinal IR injury rat model was established by clamping of the superior mesenteric artery (SMA) for 30 min and reperfusion for 2 h. HFMSCs were cultured in vitro and injected into the rats through the tail vein. Seven days after treatment, the intrinsic homing and differentiation characteristics of the HFMSCs were observed by immunofluorescence and immunohistochemical staining, and the paracrine mechanism of HFMSCs was assessed by Western blotting and enzyme-linked immunosorbent assay (ELISA).Results: A small intestinal IR injury model was successfully established. HFMSCs could home to damaged sites, express proliferating cell nuclear antigen (PCNA) and intestinal stem cell (ISC) markers, and promote small intestinal ISC marker expression. The expression levels of angiopoietin-1 (ANG1), vascular endothelial growth factor (VEGF) and insulin growth factor-1 (IGF1) in the IR + HFMSCs group were higher than those in the IR group. HFMSCs could prevent IR-induced apoptosis by increasing B-cell lymphoma-2 (Bcl-2) expression and decreasing Bcl-2 homologous antagonist/killer (Bax) expression. Oxidative stress level detection showed that the malondialdehyde (MDA) content was decreased, while the superoxide dismutase (SOD) content was increased in the IR + HFMSCs group compared to the IR group. An elevated diamine oxidase (DAO) level reflected the potential protective effect of HFMSCs on the intestinal mucosal barrier.Conclusion: HFMSCs are beneficial to alleviate small intestinal IR injury through intrinsic homing to the small intestine and by differentiating into ISCs, via a paracrine mechanism to promote angiogenesis, reduce apoptosis, regulate the oxidative stress response, and protect intestinal mucosal function potentially. Therefore, this study suggests that HFMSCs serve as a new option for the treatment of small intestinal IR injury.

BACKGROUND: Human umbilical cord mesenchymal stem cells have the characteristics of strong differentiation and immunoregulation, which have been widely concerned in cell therapy. OBJECTIVE: To summarize the research progress of human umbilical cord mesenchymal stem cells in the treatment of endometrial related diseases. METHODS: Key words were “human umbilical cord mesenchymal stem cells, endometrium, endometriosis, intrauterine adhesions, thin endometrium” in Chinese and English. PubMed, CNKI, and Wanfang databases were retrieved for articles published from 1991 to 2020. Totally 64 articles meeting the inclusion criteria were reviewed and analyzed. RESULTS AND CONCLUSION: (1) Human umbilical cord mesenchymal stem cells, as a kind of stem cells with considerable development potential, have the advantages of rich sources, convenient collection, significant cell proliferation and differentiation. (2) Human umbilical cord mesenchymal stem cells promote the repair of endometrial cell injury, reduce scar formation and improve endometrial function through immune regulation, cell differentiation and downregulation of fibrotic gene expression, which is conducive to embryo implantation and pregnancy. (3) The important mechanism of human umbilical cord mesenchymal stem cell transplantation for endometrium may be related to their paracrine cytokines and nutritional factors, and these factors participate in endometrial repair and immune regulation. (4) The treatment method based on human umbilical cord mesenchymal stem cells has achieved some promising results in the treatment of endometrial injury diseases, such as inhibiting the proliferation and promoting the apoptosis of endometrial cells in vitro, and restoring the fertility of endometriosis rats by repairing the damaged endometrium. It can remarkably promote the regenerative repair of endometrium in rats with severe intrauterine adhesion syndrome, promote vascular regeneration, restore endometrial function, increase the thickness of endometrium through immune regulation, improve endometrial receptivity, and provide new ideas for the treatment of thin endometrium. (5) Human umbilical cord mesenchymal stem cells can escape the recognition of the body’s immune system and avoid host monitoring, so infusion into the body will not cause strong rejection. (6) At present, most of the research is still limited to animal experiments, and its application in clinical treatment is not extensive. In the future, more clinical trials are needed to further study treatment mechanism of human umbilical cord mesenchymal stem cells for endometrium. [ABSTRACT FROM AUTHOR]

Aging is one of the causative agents associated with heart failure. Cell-based therapies show potential in the treatment of cardiac aging due to the characteristics of stem cells, including differentiation and the paracrine effect. This study aimed to investigate in detail the mechanism related to biomolecules released from mesenchymal stem cells in the treatment of cardiac aging. In vitro and in vivo models were designed to explore the above hypothesis. Experimental results from the in vitro model indicated that the elevation of oxidative stress, the expression of aging marker p53, and the suppression of antioxidant marker SOD2 could be found in D-galactose-stressed H9c2 cardiomyoblasts. The co-culture of D-galactose-stressed H9c2 with mesenchymal stem cells significantly improved the above pathological signaling. An animal model revealed that the change in cardiac structure, the accumulation of fibrotic collagen, and the activation of the above pathological signaling could be observed in heart tissues of D-galactose-stressed rats. After the rats had received mesenchymal stem cells, all the pathological conditions were significantly improved in D-galactose-stressed hearts. Further evidence indicated that the release of the survival marker IGF-1 was detected in a stem-cell-conditioned medium. Significant increases in cell viability and the expression of SOD2, as well as a reduction in oxidative stress and the suppression of p53, were found in D-galactose-stressed H9c2 cells cultured with a stem-cell-conditioned medium, whereas the depletion of IGF-1 in stem-cell-conditioned medium diminished the antiaging effect on H9c2 cells. In conclusion, the paracrine release of IGF-1 from mesenchymal stem cells increases the expression of antioxidant marker SOD2, and the expression of SOD2 reduces oxidative stress as well as suppresses p53, leading to a reduction in cardiac senescence in D-galactose-stressed rats. [ABSTRACT FROM AUTHOR]

Understanding the molecular mechanisms of nociception has recently grown impressively. Nociception is mediated by mechanical, chemical, or microbial stimuli that evoke unpleasant feelings, alerting the host of the risk of tissue damage. Such diverse arrays of noxious stimuli trigger various escape reactions, usually altering immune homeostasis. Notably, nociceptors can recognize cytokines or pathogens via sensory molecules or innate immune receptors, participating in immune responses. Accumulating evidence suggests that activated nociceptors produce various humoral factors that affect the immune system and act like endocrine/paracrine signals. Thus, understanding the interplay between the nociceptive and immune systems may open new avenues for the development of an interdisciplinary research field, hereinafter referred to as 'senso‐immunology'. This review will discuss the physiological relevance of the senso‐immune system in the host defense context, focusing on how senso‐immune research might yield novel treatments to cure pain and inflammation. [ABSTRACT FROM AUTHOR]

A new paradigm of cell therapy-based approaches as a solution to several diseases caused by damage or loss of cells/tissues leading to organ failure heralded the birth of a new branch in medicine called regenerative medicine (RM), which was further fueled by in vitro cell expansion and tissue engineering (TE) technologies, including the ability to grow embryonic stem cells, induce pluripotent stem cells, and so on. RM addresses organ failure by repair, regeneration, or restoration, rejuvenation using cells, stem cells, or progenitor cells as tools having added cell-derived products also as a tool, and extracellular matrix component-based support, either direct or indirect (e.g., matrix induced autologous chondrocyte implantation) using scaffolds. Now, the main objective of RM is to solve the functional loss of cells that have evolved from cells as tools to cell-derived factors and scaffolds per se as tools. In this context, an important yet indispensable group of cells that constitute the major portion of the human body in terms of the number of cells having several essential roles to play, both directly and indirectly, starting from digestion and the immune system to the growing evidence of influencing neuronal function, aging, and carcinogenesis has been ignored. We would like to focus on these in this review as they should essentially be considered as a tool of RM, especially for neurological disorders for their vital role. What we are indicating is the second genome or the gut microbiome. [ABSTRACT FROM AUTHOR]

Background: Endothelial damage is an initial step of macro- and micro-vasculature dysfunctions in diabetic patients, accounting for a high incidence of diabetic vascular complications, such as atherosclerosis, nephropathy, retinopathy, and neuropathy. However, clinic lacks effective therapeutics targeting diabetic vascular complications. In field of regenerative medicine, mesenchymal stem cells, such as human umbilical cord-derived MSCs (hucMSCs), have great potential in treating tissue damage. Methods: To determine whether hucMSCs infusion could repair diabetic vascular endothelial damage and how it works, this study conducted in vivo experiment on streptozotocin-induced diabetic rat model to test body weight, fasting blood glucose (FBG), serum ICAM-1 and VCAM-1 levels, histopathology and immunohistochemical staining of aorta segments. In vitro experiment was further conducted to determine the effects of hucMSCs on diabetic vascular endothelial damage, applying assays of resazurin staining, MTT cell viability, wound healing, transwell migration, and matrigel tube formation on human umbilical vein endothelial cells (HUVECs). RNA sequencing (RNAseq) and molecular experiment were conducted to clarify the mechanism of hucMSCs. Results: The in vivo data revealed that hucMSCs partially restore the alterations of body weight, FBG, serum ICAM-1 and VCAM-1 levels, histopathology of aorta and reversed the abnormal phosphorylation of ERK in diabetic rats. By using the conditioned medium of hucMSCs (MSC-CM), the in vitro data revealed that hucMSCs improved cell viability, wound healing, migration and angiogenesis of the high glucose-damaged HUVECs through a paracrine action mode, and the altered gene expressions of IL-6, TNF-α, ICAM-1, VCAM-1, BAX, P16, P53 and ET-1 were significantly restored by MSC-CM. RNAseq incorporated with real-time PCR and Western blot results clarified that high glucose activated MAPK/ERK signaling in HUVECs, while MSC-CM reversed the abnormal phosphorylation of ERK and overexpressions of MKNK2, ERBB3, MYC and DUSP5 in MAPK/ERK signaling pathway. Conclusions: HucMSCs not only ameliorated blood glucose but also protected vascular endothelium from diabetic damage, in which MAPK/ERK signaling mediated its molecular mechanism of paracrine action. Our findings provided novel knowledge of hucMSCs in the treatment of diabetes and suggested a prospective strategy for the clinical treatment of diabetic vascular complications. [ABSTRACT FROM AUTHOR]

Obesity has recently been defined as a chronic low-grade inflammatory disease. Obesity-induced inflammation of adipose tissue (AT) is an essential trigger for insulin resistance (IR) and related metabolic diseases. Although the underlying molecular basis of this inflammation has not been fully identified, there is consensus that the recruited and activated macrophages in AT are the most important culprits of AT chronic inflammation. Adipose tissue macrophages (ATMs) are highly plastic and could be polarized from an anti-inflammatory M2 to proinflammatory M1 phenotypes on stimulation by microenvironmental signals from obese AT. Many efforts have been made to elucidate the molecular signaling pathways of macrophage polarization; however, the upstream drivers governing and activating macrophage polarization have rarely been summarized, particularly regulatory messages from the AT microenvironment. In addition to adipocytes, the AT bed also contains a variety of immune cells, stem cells, as well as vascular, neural, and lymphatic tissues throughout, which together orchestrate the AT microenvironment. Here, we summarize how the aforesaid neighbors of ATMs in the AT microenvironment send messages to ATMs and thus regulate its phenotype during obesity. Deciphering the biology and polarization of ATMs in the obese environment is expected to provide a precise immunotherapy for adipose inflammation and obesity-related metabolic diseases. [ABSTRACT FROM AUTHOR]

The well-developed placentation is fundamental for the reproductive pregnancy while the defective placental development is the pathogenetic basis of preeclampsia (PE), a dangerous complication of pregnancy comprising the leading causes of maternal and perinatal morbidity and mortality. Placenta-derived mesenchymal stem cells (PMSCs) are a group of multipotent stem cells that own a potent capacity of differentiating into constitutive cells of vessel walls. Additionally, with the paracrine secretion of various factors, PMSCs inextricably link and interact with other component cells in the placenta, collectively improving the placental vasculature, uterine spiral artery remolding, and uteroplacental interface immunoregulation. Recent studies have further indicated that preeclamptic PMSCs, closely implicated in the abnormal crosstalk between other ambient cells, disturb the homeostasis and development in the placenta. Nevertheless, PMSCs transplantation or PMSCs exosome therapies tend to improve the placental vascular network and trophoblastic functions in the PE model, suggesting PMSCs may be a novel and putative therapeutic strategy for PE. Herein, we provide an overview of the multifaceted contributions of PMSCs in early placental development. Thereinto, the intensive interactions between PMSCs and other component cells in the placenta were particularly highlighted and further extended to the implications in the pathogenesis and therapeutic strategies of PE. [ABSTRACT FROM AUTHOR]

Abstract Background Osteoarthritis (OA) is the most common joint degenerative disorder, with little effective therapy to date. Nanofat is a cocktail of cells obtained from fat tissue, which possesses regenerative capacity and has a potential in treating OA. This study aimed to determine the anti-OA efficacy of Nanofat from basic and clinical aspects and explore its action mode. Methods Flow cytometry was performed to characterize Nanofat. A monoiodoacetate-induced OA rat model was employed for in vivo study. Cell viability and wound healing assays were conducted for in vitro study. Real-time PCR and Western blot assays were applied to explore the molecular action mode of Nanofat. Moreover, a retrospective analysis was conducted to determine the clinical efficacy and safety of Nanofat on knee OA patients. Results The in vivo results showed that Nanofat significantly attenuated pain symptoms and protected cartilage ECM (Col2) from damage, and its effects were not significantly differed with adipose tissue-derived stem cells (both P > 0.05). The in vitro results showed that Nanofat promoted the cell viability and migration of chondrocytes and significantly restored the IL-1β-induced abnormal gene expressions of Col2, Aggrecan, Sox9, Adamts5, Mmp3, Mmp9 Mmp13, IL-6 and Col10 and protein expressions of Col2, MMP9, MMP13, and Sox9 of chondrocytes. The regulatory actions of Nanofat on these anabolic, catabolic, and hypertrophic molecules of chondrocytes were similar between two treatment routes: co-culture and conditioned medium, suggesting a paracrine-based mode of action of Nanofat. Moreover, the clinical data showed that Nanofat relieved pain and repaired damaged cartilage of OA patients, with no adverse events. Conclusion In sum, this study demonstrated the anti-OA efficacy as well as a paracrine-based action mode of Nanofat, providing novel knowledge of Nanofat and suggesting it as a promising and practical cell therapy for clinical treatment of OA.

To research the paracrine role of adipose tissue-derived mesenchymal stem cells (ADMSCs) in promoting angiogenesis under the three-dimensional culture conditions consisting of a functionalized self-assembling peptide nanofiber hydrogel. ADMSCs were isolated, extracted, and then identified. Three kinds of peptides (RADAI-16, RGD, and KLT) were prepared, and a functionalized self-assembling peptide nanofiber hydrogel was produced by mixing RADAI-16, RGD, and KLT in a volume ratio 2:1:1. AFM was used to observe RADAI-16, RGD, KLT, and the functionalized self-assembling peptide nanofiber hydrogel. Then, ADMSCs were cultured under three-dimensional conditions consisting of the peptide nanofiber hydrogel, and AFM was used to observe cell migration. The ADMSCs in the common culture group (37°C, 5% CO2 cell culture box) and hypoxic culture group (37°C, 10% CO2, and 1% O2 hypoxic culture box) acted as controls. ADMSCs were three-dimensionally cultured in situ for 1 day, and then the concentrations of HGF and VEGF in the supernatant were determined by ELISA. Cells were extracted from the peptide nanofiber hydrogel, and HO-1 expression was detected by western blotting. ADMSCs have high expression levels of CD29, CD90, and CDl05 and low expression levels of CD34 and CD45. In addition, they can differentiate into adipocytes and osteocytes. The diameters of the fibers of RADAI-16, RGD, KLT, and the functionalized self-assembling peptide hydrogel are 17.34 ± 1.82, 15.50 ± 1.41, 13.77 ± 1.18, and 20.26 ± 1.25 nm, respectively. AFM indicated that cells in the functionalized self-assembling peptide nanofiber hydrogel migrated farther than those in RADAI-16. The concentrations of HGF under common, hypoxic, and three-dimensional culture conditions were 47.31 ± 6.75, 247.86 ± 17.59, and 297.25 ± 17.95 pg/mL, respectively, while the concentrations of VEGF were 218.30 ± 3.03, 267.13 ± 4.27, and 289.14 ± 3.11 pg/mL, respectively. Both HGF and VEGF were expressed more in the presence of the functionalized self-assembling peptide nanofiber hydrogel than in its absence (P < 0.05). Using western blotting, ADMSCs cultured under hypoxic and three-dimensional conditions were found to have high expression levels of HO-1. Culturing ADMSCs under three-dimensional conditions consisting of functionalized self-assembling peptide nanofiber hydrogels can promote their paracrine role in angiogenesis, such as HGF and VEGF, and hypoxia is one of the important elements.

Abstract Background Effective treatments for acute-on-chronic liver failure (ACLF) are lacking. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have been applied in tissue regeneration and repair, acting through paracrine effects, cell fusion, and actual transdifferentiation. The present study was designed to investigate the therapeutic potential of hUC-MSCs in acute-on-chronic liver injury (ACLI) and ACLF rat models. Methods Wistar rats aged 6 weeks were intraperitoneally administered porcine serum (PS) at a dose of 0.5 mL twice per week for 11 weeks to generate an immune liver fibrosis model. After 11 weeks, rats with immune liver fibrosis were injected intravenously with lipopolysaccharide (LPS) to induce an ACLI model or combined LPS and D-galactosamine (D-GalN) to induce an ACLF model. The rats with ACLI or ACLF were injected intravenously with 2×106 hUC-MSCs, 4×106 hUC-MSCs, or 0.9% sodium chloride as a control. The rats were sacrificed at 1, 2, 4, and 6 weeks (ACLI rats) or 4, 12, and 24 h (ACLF rats). The blood and liver tissues were collected for biochemical and histological investigation. Results The application of hUC-MSCs in rats with ACLI and ACLF led to a significant decrease in the serum levels of ALT, AST, TBil, DBil, ALP, ammonia, and PT, with ALB gradually returned to normal levels. Inflammatory cell infiltration and collagen fiber deposition in liver tissues were significantly attenuated in ACLI rats that received hUC-MSCs. Inflammatory cell infiltration and apoptosis in liver tissues of ACLF rats that received hUC-MSCs were significantly attenuated. Compared with those in the rats that received 0.9% sodium chloride, a significant reduction in proinflammatory cytokine levels and elevated serum levels of hepatocyte growth factor (HGF) were found in ACLF rats that received hUC-MSCs. Furthermore, Notch, IFN-γ/Stat1, and IL-6/Stat3 signaling were inhibited in ACLI/ACLF rats that received hUC-MSCs. Conclusions hUC-MSC transplantation can improve liver function, the degree of fibrosis, and liver damage and promote liver repair in rats with ACLI or ACLF, mediated most likely by inhibiting Notch signaling and reversing the imbalance of the Stat1/Stat3 pathway.

Wenshen Xiaozheng Tang (WXT), a traditional Chinese medicine (TCM) decoction, is effective for treating endometriosis. However, the effect of WXT on endometrium-derived mesenchymal stem cells (eMSCs) which play a key role in the fibrogenesis of endometriosis requires further elucidation. The aim of this study was to clarify the potential mechanism of WXT in improving fibrosis in endometriosis by investigating the regulation of WXT on differentiation and paracrine of eMSCs. The nude mice with endometriosis were randomly divided into model group, WXT group and mifepristone group. After 21 days of treatment, the lesion volume was calculated. Fibrosis in the lesions was evaluated by Masson staining and expression of fibrotic proteins. The differentiation of eMSCs in vivo was explored using a fate-tracking experiment. To further clarify the regulation of WXT on eMSCs, primary eMSCs from the ectopic lesions of endometriosis patients were isolated and characterized. The effect of WXT on the proliferation and differentiation of ectopic eMSCs was examined. To evaluate the role of WXT on the paracrine activity of ectopic eMSCs, the conditioned medium (CM) from ectopic eMSCs pretreated with WXT was collected and applied to treat ectopic endometrial stromal cells (ESCs), after which the expression of fibrotic proteins in ectopic ESCs was assessed. In addition, transcriptome sequencing was used to investigate the regulatory mechanism of WXT on ectopic eMSCs, and western blot and ELISA were employed to determine the key mediator. WXT impeded the growth of ectopic lesions in nude mice with endometriosis and reduced collagen deposition and the expression of fibrotic proteins fibronectin, collagen I, α-SMA and CTGF in the endometriotic lesions. The fate-tracking experiment showed that WXT prevented human eMSCs from differentiating into myofibroblasts in the nude mice. We successfully isolated eMSCs from the lesions of patients with endometriosis and demonstrated that WXT suppressed proliferation and myofibroblast differentiation of ectopic eMSCs. Moreover, the expression of α-SMA, collagen I, fibronectin and CTGF in ectopic ESCs was significantly down-regulated by the CM of ectopic MSCs pretreated with WXT. Combining the results of RNA sequencing, western blot and ELISA, we found that WXT not only reduced thrombospondin 4 expression in ectopic eMSCs, but also decreased thrombospondin 4 secretion from ectopic eMSCs. Thrombospondin 4 concentration-dependently upregulated the expression of collagen I, fibronectin, α-SMA and CTGF in ectopic ESCs, indicating that thrombospondin 4 was a key mediator of WXT in inhibiting the fibrotic process in endometriosis. WXT improved fibrosis in endometriosis by regulating differentiation and paracrine signaling of eMSCs. Thrombospondin 4, whose release from ectopic eMSCs is inhibited by WXT, may be a potential target for the treatment of endometriosis. [Display omitted] • WXT, a traditional Chinese medicine decoction, is effective for improving fibrosis in endometriosis. • WXT improves fibrosis in endometriosis by regulating differentiation and paracrine of ectopic eMSCs. • WXT reduced the expression and secretion of thrombospondin 4 by ectopic eMSCs. • Thrombospondin 4 promotes the expression of fibrotic proteins in ectopic ESCs. [ABSTRACT FROM AUTHOR]

The combination of biological scaffold and neural stem cells (NSCs) is a promising treatment strategy for spinal cord injury (SCI). But adverse niche at injures spinal cord severe hamper the transplanted NSCs to preferentially differentiate neurons. In this study, we compared the therapeutic outcomes in rat completely transected SCI model after transplantations of collagen scaffold loaded with NSCs in different forms including unicellular NSCs, neurospheres, differentiated unicellular NSCs, and differentiated neurospheres. The results showed collagen scaffold combined each form of NSCs could markedly restore the motor function of the hindlimbs by Basso-Beattie-Bresnahan(BBB) scoring to similar levels. The transcriptome analysis showed there were similar expressions of neurotrophic factors among neurospheres, differentiated unicellular NSCs, and differentiated neurospere. Next, we enriched neurotrophic factors secreted from culture medium of these three forms of NSCs respectively and combined with collagen scaffold were transplanted into SCI to further assay therapeutic effects of secreting neurotrophic factors on SCI. BBB score analysis showed that the secreted neurotrophic factors from above three forms of NSCs had similar functional recovery of SCI. Therefore, we proposed that allogeneic NSCs transplant promotes functional recovery of SCI predominantly by secreting neurotrophic factors, not by direct neuronal replacement of differentiated neurons from transplanted cells.

The well-developed placentation is fundamental for the reproductive pregnancy while the defective placental development is the pathogenetic basis of preeclampsia (PE), a dangerous complication of pregnancy comprising the leading causes of maternal and perinatal morbidity and mortality. Placenta-derived mesenchymal stem cells (PMSCs) are a group of multipotent stem cells that own a potent capacity of differentiating into constitutive cells of vessel walls. Additionally, with the paracrine secretion of various factors, PMSCs inextricably link and interact with other component cells in the placenta, collectively improving the placental vasculature, uterine spiral artery remolding, and uteroplacental interface immunoregulation. Recent studies have further indicated that preeclamptic PMSCs, closely implicated in the abnormal crosstalk between other ambient cells, disturb the homeostasis and development in the placenta. Nevertheless, PMSCs transplantation or PMSCs exosome therapies tend to improve the placental vascular network and trophoblastic functions in the PE model, suggesting PMSCs may be a novel and putative therapeutic strategy for PE. Herein, we provide an overview of the multifaceted contributions of PMSCs in early placental development. Thereinto, the intensive interactions between PMSCs and other component cells in the placenta were particularly highlighted and further extended to the implications in the pathogenesis and therapeutic strategies of PE.

Wound healing is a complex process of repair that involves the interaction between different cell types and involves coordinated interactions between intracellular and extracellular signaling. Bone Marrow Mesenchymal Stem Cells (BMSCs) based and acellular amniotic membrane (AM) therapeutic strategies with the potential for treatment and regeneration of tissue. We aimed to evaluate the involvement of paracrine effects in tissue repair after the flap skin lesion rat model. In the full-thickness flap skin experiment of forty Wistar rats: A total of 40 male Wistar rats were randomized into four groups: group I: control (C; n = 10), with full-thickness lesions on the back, without (BMSCs) or AM (n = 10); group II: injected (BMSCs; n = 10); group III: covered by AM; group IV–injected (AM + BMSCs; n = 10). Cytokine levels, IL-1, and IL-10 assay kits, superoxide dismutase (SOD), glutathione reductase (GRs) and carbonyl activity levels were measured by ELISA 28th day, and TGF-β was evaluated by immunohistochemical, the expression collagen expression was evaluated by Picrosirius staining. Our results showed that the IL-1 interleukin was higher in the control group, and the IL-10 presented a higher mean when compared to the control group. The groups with BMSCs and AM showed the lowest expression levels of TGF-β. SOD, GRs, and carbonyl activity analysis showed a predominance in groups that received treatment from 80%. The collagen fiber type I was predominant in all groups; however, the AM + BMSCs group obtained a higher average when compared to the control group. Our findings suggest that the AM+ BMSCs promote skin wound healing, probably owing to their paracrine effect attributed to the promotion of new collagen for tissue repair.

The pancreatic islet is responsive to an array of endocrine, paracrine, and nutritional inputs that adjust hormone secretion to ensure accurate control of glucose homeostasis. Although the mechanisms governing glucose-coupled insulin secretion have received the most attention, there is emerging evidence for a multitude of physiological signaling pathways and paracrine networks that collectively regulate insulin, glucagon, and somatostatin release. Moreover, the modulation of these pathways in conditions of glucotoxicity or lipotoxicity are areas of both growing interest and controversy. In this review, the contributions of external, intrinsic, and paracrine factors in pancreatic β-, α-, and δ-cell secretion across the full spectrum of physiological (i.e., fasting and fed) and pathophysiological (glucoand lipotoxicity; diabetes) environments will be critically discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: This study provides novel mechanistic insights into the capacity of the inflammatory cytokine IL-6 and its associated STAT3-dependent signaling pathway to stimulate proliferation in trans between individual sub-clones in a model of heterogeneity in inflammatory breast cancer. The clinical relevance of this discovery is provided by our observation that proliferation of the IL-6 responsive subclone is sensitive to inhibition with the clinically approved anti-IL-6 receptor humanized monoclonal antibody Tocilizumab. These findings therefore provide a rationale for potentially repurposing Tocilizumab for the treatment of a subset of inflammatory breast cancer patients. Inflammatory breast cancer (IBC) describes a highly aggressive form of breast cancer of diverse molecular subtypes and clonal heterogeneity across individual tumors. Accordingly, IBC is recognized by its clinical signs of inflammation, associated with expression of interleukin (IL)-6 and other inflammatory cytokines. Here, we investigate whether sub-clonal differences between expression of components of the IL-6 signaling cascade reveal a novel role for IL-6 to mediate a proliferative response in trans using two prototypical IBC cell lines. We find that SUM149 and SUM 190 cells faithfully replicate differential expression observed in a subset of human IBC specimens between IL-6, the activated form of the key downstream transcription factor STAT3, and of the HER2 receptor. Surprisingly, the high level of IL-6 produced by SUM149 cells activates STAT3 and stimulates proliferation in SUM190 cells, but not in SUM149 cells with low IL-6R expression. Importantly, SUM149 conditioned medium or co-culture with SUM149 cells induced growth of SUM190 cells, and this effect was abrogated by the IL-6R neutralizing antibody Tocilizumab. The results suggest a novel function for inter-clonal IL-6 signaling in IBC, whereby IL-6 promotes in trans proliferation of IL-6R and HER2-expressing responsive sub-clones and, therefore, may provide a vulnerability that can be exploited therapeutically by repurposing of a clinically approved antibody. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor 1 (Igf1) and insulin-like growth factor binding protein 3 (Igfbp3) are endocrine and paracrine factors that influence stroke occurrence, severity, and recovery. Low levels of endocrine Igf1 and Igfbp3 were associated with larger infarct volumes and unfavorable outcomes. Paracrine Igf1 is brain cytoprotective and improves functional recovery after stroke. In this study, we evaluated the effects of zinc finger protein 580 (Zfp580) on endocrine and paracrine Igf1 and Igfbp3 after stroke. Zfp580 suppressed the expression of Igf1 and Igfbp3 in cerebral microvascular endothelial cells (bEnd.3) as determined by real-time RT-PCR. Zfp580 was suppressed by combined oxygen and glucose deprivation (OGD) and mediated the effect of OGD on Igf1 and Igfbp3. In vivo , we evaluated paracrine regulation by real-time RT-PCR of brain lysates and endocrine regulation by ELISA of blood samples. Genomic ablation of Zfp580 did not alter basal paracrine or endocrine Igf1 and Igfbp3 levels. After transient middle cerebral artery occlusion (MCAo), Zfp580 was globally elevated in the brain for up to 3 days. Paracrine Igf1 and Igfbp3 were selectively induced in the ischemic hemisphere from day 2 to day 3 or day 1 to day 7, respectively. In Zfp580 knockout mice, the paracrine regulations of Igf1 and Igfbp3 were attenuated while endocrine Igf1 and the molar Igf1/Igfbp3 ratio were increased. In conclusion, Zfp580 differentially controls paracrine and endocrine Igf1 and Igfbp3 after stroke. Inhibition of Zfp580 might be a new treatment target leading to increased activity of Igf1 to improve stroke outcome. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis (OA) is the most common joint disorder, lacking disease-modifying treatments. Adipose-derived mesenchymal stem cells (ADSCs) are adult multipotent stromal cells obtained from fat tissue, which holds great potential in treating OA. This study aimed to evaluate the anti-OA efficacy of ADSCs from preclinical and clinical facets and explore the underlying mechanism of action. Methods: In vivo , a single dose of 5 × 105 ADSCs was injected into the knee joints of monoiodoacetate-induced OA rat model. The levels of metabolic and hypertrophic molecules (MMP13, Collagen II, Collagen X) of chondrocytes were measured by immunohistochemistry. In vitro , cell viability assay was conducted to detect the proliferation ability of chondrocytes treated with ADSCs conditioned medium (ADSCs-CM). Quantitative real-time polymerase chain reaction and Western blot assays were applied to explore the mechanism of action of ADSCs. Moreover, a retrospective analysis was conducted to determine the clinical efficacy and safety of ADSCs on OA patients. Results: The animal study showed that ADSCs significantly alleviated OA cartilage lesions in rats, as was confirmed by downregulation of the MMP13 and Collagen X and upregulation of the Collagen II. In vitro data showed that ADSCs-CM promoted the proliferation of chondrocytes, and significantly restored the IL-1β-induced abnormal expressions of molecular markers IL-6, Aggrecan, MMP3, MMP13, Collagen II, Collagen X, ADAMTS5, ADAMTS9, SOX6, and SOX9 in chondrocytes. Such regulatory effects of ADSCs-CM on the proliferation and these anabolic, catabolic, and hypertrophic markers of chondrocytes suggested a paracrine-based mode of action of ADSCs. Furthermore, the clinical data showed that ADSCs reduced pain and repaired cartilage damage in OA patients, with no adverse events. Conclusion: This study demonstrated the anti-OA efficacy, safety, and a paracrine-based mechanism of ADSCs, providing a promising cell-based therapeutic option for OA treatment. [ABSTRACT FROM AUTHOR]

Spermatogenesis in testis is an important process for sexual reproduction, and worldwide about 10–15 percent of couples suffer from infertility. It is of importance to study spermatogenesis at single cell level in both of human and model organisms. Currently, single-cell RNA sequencing technologies (scRNA-seq) had been extensively applied to the study of cellular components and its gene regulations in the testes of different species, including human, monkey, mouse, and fly, but not in zebrafish. Zebrafish was a widely used model organism in biology and had been extensively used for the study of spermatogenesis in the previous studies. Therefore, it is also important to profile the transcriptome of zebrafish testis at single cell level. In this study, the transcriptomes of 14, 315 single cells from adult male zebrafish testes were profiled by scRNA-seq, and 10 cell populations were revealed, including Leydig cell, Sertoli cell, spermatogonia cell (SPG), spermatocyte, and spermatids. Notably, thousands of cell-type specific novel marker genes were identified, including sumo3b for SPG, krt18a.1 for Sertoli cells, larp1b and edrf1 for spermatids, which were also validated by RNA in situ hybridization experiments. Interestingly, through Ligand-Receptor (LR) analyses, zebrafish Leydig cells demonstrated stronger paracrine influence on germ cells than Sertoli cells. Overall, this study could be an important resource for the study of spermatogenesis in zebrafish and might also facilitate the study of the genes associated with human infertility through using zebrafish as a model organism. [ABSTRACT FROM AUTHOR]

Insulin stimulates adipose tissue to extract fatty acids from circulation and sequester them inside adipose cells. How fatty acids are transported across the capillary endothelial barrier, and how this process is regulated, remains unclear. We modeled the relationship of adipocytes and endothelial cells in vitro to test the role of insulin in fatty acid transport. Treatment of endothelial cells with insulin did not affect endothelial fatty acid uptake, but endothelial cells took up more fatty acids when exposed to medium conditioned by adipocytes treated with insulin. Manipulations of this conditioned medium indicated that the secreted factor is a small, hydrophilic, non-proteinaceous metabolite. Factor activity was correlated with lactate concentration, and inhibition of lactate production in adipocytes abolished the activity. Finally, lactate alone was sufficient to increase endothelial uptake of both free fatty acids and lipids liberated from chylomicrons, and to promote transendothelial transport, at physiologically relevant concentrations. Taken together, these data suggest that insulin drives adipocytes to secrete lactate, which then acts in a paracrine fashion to promote fatty acid uptake and transport across the neighboring endothelial barrier. [ABSTRACT FROM AUTHOR]