Therapeutic utility of human umbilical cord-derived mesenchymal stem cells-based approaches in pulmonary diseases:Recent advancements and prospects

Pulmonary diseases across all ages threaten millions of people and have emerged as one of the major public health issues worldwide.For diverse disease con-ditions,the currently available approaches are focused on alleviating clinical symptoms and delaying disease progression but have not shown significant therapeutic effects in patients with lung diseases.Human umbilical cord-derived mesenchymal stem cells(UC-MSCs)isolated from the human UC have the capacity for self-renewal and multilineage differentiation.Moreover,in recent years,these cells have been demonstrated to have unique advantages in the treatment of lung diseases.We searched the Public Clinical Trial Database and found 55 clinical trials involving UC-MSC therapy for pulmonary diseases,including coronavirus disease 2019,acute respiratory distress syndrome,bron-chopulmonary dysplasia,chronic obstructive pulmonary disease,and pulmonary fibrosis.In this review,we summarize the characteristics of these registered clinical trials and relevant published results and explore in depth the challenges and opportunitiesfaced in clinical application.Moreover,the underlying mole-cular mechanisms involved in UC-MSC-based therapy for pulmonary diseases are also analyzed in depth.In brief,this comprehensive review and detailed analysis of these clinical trials can be expected to provide a scientific reference for future large-scale clinical application.

Human umbilical cord-derived mesenchymal stem cells treatment for refractory uveitis: a case series

AIM:To evaluate therapeutic outcomes of human umbilical cord-derived mesenchymal stem cells(HUC-MSCs)treatment in patients with refractory uveitis.METHODS:A retrospective and noncomparative review was performed on four patients with refractory uveitis from December 2013 to December 2017.HUC-MSCs were administered intravenously at a dose of 1×106 cells/kg.Clinical response,relapse rate,change of visual acuity,and other metrics were evaluated.RESULTS:All four patients presented with responses to HUC-MSCs treatment,with three males and one female.The numbers of uveitis attacks per year after the HUCMSCs treatment(0,2,0,0 respectively)all decreased compared with the numbers before the treatment(3,6,4,4 respectively).The oral steroid and immunosuppressive agents were tapered in all patients without recrudescence of ocular inflammation,and three patients discontinued their oral medicine at the last visit.The best corrected visual acuity(BCVA)of 3 patients was improved to varying degrees,and the BCVA of 1 patient remained at 20/20(Snellen chart)from the first to the last consultation.CONCLUSION:The study provides an effective therapy of HUC-MSCs in maintaining remission in patients affected by uveitis refractory to previous immunosuppressant treatments.

Alopecia treatment using minimally manipulated human umbilical cord-derived mesenchymal stem cells:Three case reports and review of literature

BACKGROUND Alopecia areata(AA)is a common autoimmune disease characterized by hair loss.AA appears in extensive forms,such as progressive and diffusing hair loss(diffuse AA),a total loss of scalp hair(alopecia totalis),and complete loss of hair over the entire body(alopecia universalis).Recently,mesenchymal stem cells(MSCs)have been identified as a therapeutic alternative for autoimmune diseases.For this reason,preclinical and case studies of AA and related diseases using MSCs have been conducted.CASE SUMMARY Case 1:A 55-year-old woman suffered from AA in two areas of the scalp.She was given 15 rounds of minimally manipulated umbilical cord-MSCs(MM-UC-MSCs)over 6 mo.The AA gradually improved 3 mo after the first round.The patient was cured,and AA did not recur.Case 2:A 30-year-old woman,with history of local steroid hormone injections,suffered from AA in one area on the scalp.She was given two rounds of MM-UC-MSCs over 1 mo.The AA immediately improved after the first round.The patient was cured,and AA did not recur.Case 3:A 20-year-old woman,who was diagnosed with alopecia universalis at the age of 12,was given 14 rounds of MM-UC-MSCs over 12 mo.Her hair began to grow about 3 mo after the first round.The patient was cured,and alopecia universalis did not recur.CONCLUSION MM-UC-MSC transplantation potentially treats patients who suffer from AA and related diseases.

Human umbilical cord-derived mesenchymal stem cells promote repair of neonatal brain injury caused by hypoxia/ischemia in rats

Administration of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)is believed to be an effective method for treating neurodevelopmental disorde rs.In this study,we investigated the possibility of hUC-MSCs treatment of neonatal hypoxic/ischemic brain injury associated with maternal immune activation and the underlying mechanism.We established neonatal rat models of hypoxic/ischemic brain injury by exposing pregnant rats to lipopolysaccharide on day 16 or 17 of pregnancy.Rat offspring were intranasally administe red hUC-MSCs on postnatal day 14.We found that polypyrimidine tract-binding protein-1(PTBP-1)participated in the regulation of lipopolysaccharide-induced maternal immune activation,which led to neonatal hypoxic/ischemic brain injury.Intranasal delive ry of hUC-MSCs inhibited PTBP-1 expression,alleviated neonatal brain injury-related inflammation,and regulated the number and function of glial fibrillary acidic protein-positive astrocytes,there by promoting plastic regeneration of neurons and im p roving brain function.These findings suggest that hUC-MSCs can effectively promote the repair of neonatal hypoxic/ischemic brain injury related to maternal immune activation through inhibition of PTBP-1 expression and astrocyte activation.

Human umbilical cord-derived mesenchymal stem cells: Current trends and future perspectives

Among resources of mesenchymal stem cells, human umbilical cord appears to be a rising source capable of differentiating into all germ layers, reaching and repairing lesion areas, and promoting wound repair, and it has also the capacity to influence the immune response. Human umbilical cord-derived mesenchymal stem cells are considered to be an optimal resource compared with other mesenchymal stem cells sources because they require a non-invasive recovery. All these characteristics allow their use in heterogeneous applications. Human umbilical cord-derived mesenchymal stem cells can regenerate tissues, stimulate angiogenesis, modulate inflammatory pathway signals and recruit endogenous stem cell. Human umbilical cord-derived mesenchymal stem cells suppress mitogen-induced signals and modulate the activation and proliferation of several immune cells, modifying lymphocyte phenotypes activity. In culture, human umbilical cord-derived mesenchymal stem cellss show the capacity to create several tissues such as bone, cartilage, and fat. Human umbilical cord-derived mesenchymal stem cells can be isolated from the different compartments of umbilical cord and processed by using different techniques. Clinical applications of human umbilical cord-derived mesenchymal stem cells include graft-versus-host disease, autoimmune diseases such as Sj?gren's syndrome and diabetes mellitus types 1 and 2, gynecological disorders like endometriosis. Recent studies have shown possible application on rheumatoid arthritis, osteoarthritis, and neuronal degenerative diseases. This review is focused on the resources, molecular profiles, propriety, in vitro characterizations, clinical applications and possible future usage of human umbilical cord-derived mesenchymal stem cells.

<i>In vitro</i>differentiation of human umbilical cord-derived mesenchymal stem cells into CD34⁺cells via CD34 antibody

CD34+cells differentiated from mesenchymal stem cells (MSCs) have a strong biological function in cardiovascular regeneration. However, the molecular mechanisms of and the methods to improve the CD34+ cell differentiation from MSCs, especially from human MSCs (hUC-MSCs) are still unclear. In the current study, the effect of CD34 antibody on the CD34+ cell differentiation from human umbilical cord (UC)-derived MSCs (hUC-MSCs) is determined. The results have demonstrated that the expression of cd34 protein is significantly increased in hUC-MSCs treated with CD34 antibody. In addition, the cell proliferation is increased in hUC-MSCs after treatment with CD34 antibody. Moreover, the expression of PI3K, AKT, p-AKT proteins, which are signaling molecules related to stem cell differentiation, is increased by CD34 antibody. The results suggest that CD34 antibody could promote the differentiation of hUC-MSCs into CD34+ cells and PI3K/AKT may be involved in this important process.

Therapeutic effects of human umbilical cord-derived mesenchymal stem cells against acute tubular necrosis quantified through measures of iNOS, BMP-7 and Bcl-2

Introduction: Acute tubular necrosis (ATN) is the most prevalent cause of acute renal failure (ARF). Mesenchymal stem cell transplantation has been studied as a potential treatment for renal dysfunction due to ATN. Inducible nitric oxide synthase (iNOS), bone morphogenetic protein-7 (BMP-7) and B-cell lymphoma 2 (Bcl-2) are surrogate markers of renal tubular epithelial regeneration and subsequent recovery of renal function following ATN. Methods: Serum creatinine (Scr) and blood urea nitrogen (BUN), as well as expression of iNOS, BMP-7 and Bcl-2 in gentamycin-induced ATN rat kidneys was investigated after human umbilical cord-derived mesenchymal stem cell (HUC-MSC) transplantation. Immunohistochemical staining was performed in 3 groups of rats: gentamycin-induced ATN treated with HUC-MSC, gentamycin-induced ATN without HUC-MSC, and untreated rats not receiving any treatments. Results: HUC-MSC transplantation led to a reduction in Scr and BUN in the kidneys of rats with gentamycin-induced ATN. Expression of iNOS in the HUC-MSC treated group occurred later and the expression levels were much lower during gentamycin-induced ATN compared to rats with ATN that were not treated with HUC-MSC. The expression of BMP-7 and Bcl-2 in the MSC-transplanted group was significantly increased compared to both control groups of rats with injured and healthy renal tubules. Conclusions: HUC-MSCs induce renal protection in a rat model of gentamycin-induced ATN, which is associated with reduced iNOS expression and up-regulation of Bcl-2 and BMP-7.

MicroRNA-451 from Human Umbilical Cord-Derived Mesenchymal Stem Cell Exosomes Inhibits Alveolar Macrophage Autophagy via Tuberous Sclerosis Complex 1/Mammalian Target of Rapamycin Pathway to Attenuate Burn-Induced Acute Lung Injury in Rats

Objective Our previous studies established that microRNA(miR)-451 from human umbilical cord mesenchymal stem cell-derived exosomes(hUC-MSC-Exos)alleviates acute lung injury(ALI).This study aims to elucidate the mechanisms by which miR-451 in hUC-MSC-Exos reduces ALI by modulating macrophage autophagy.Methods Exosomes were isolated from hUC-MSCs.Severe burn-induced ALI rat models were treated with hUC-MSC-Exos carrying the miR-451 inhibitor.Hematoxylin-eosin staining evaluated inflammatory injury.Enzyme-linked immunosorbnent assay measured lipopolysaccharide(LPS),tumor necrosis factor-α,and interleukin-1βlevels.qRT-PCR detected miR-451 and tuberous sclerosis complex 1(TSC1)expressions.The regulatory role of miR-451 on TSC1 was determined using a dual-luciferase reporter system.Western blotting determined TSC1 and proteins related to the mammalian target of rapamycin(mTOR)pathway and autophagy.Immunofluorescence analysis was conducted to examine exosomes phagocytosis in alveolar macrophages and autophagy level.Results hUC-MSC-Exos with miR-451 inhibitor reduced burn-induced ALI and promoted macrophage autophagy.MiR-451 could be transferred from hUC-MSCs to alveolar macrophages via exosomes and directly targeted TSC1.Inhibiting miR-451 in hUC-MSC-Exos elevated TSC1 expression and inactivated the mTOR pathway in alveolar macrophages.Silencing TSC1 activated mTOR signaling and inhibited autophagy,while TSC1 knockdown reversed the autophagy from the miR-451 inhibitor-induced.Conclusion miR-451 from hUC-MSC exosomes improves ALI by suppressing alveolar macrophage autophagy through modulation of the TSC1/mTOR pathway,providing a potential therapeutic strategy for ALI.

Phase I trial of human umbilical cord-derived mesenchymal stem cells for treatment of severe bronchopulmonary dysplasia

Severe bronchopulmonary dysplasia(BPD)is a chronic lung disorder that primarily affects premature babies with extremely low birth weight and involves in multiple organ system;no effective pharmacotherapy for this disease exists,and mortality remains high.Based on the evidence from previous preclinical studies and phase I clinical trials,this study aims to test the safety of intravenous application of a single dose of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)in patients with severe BPD.The Mesenchymal Stem cells for Bronchopulmonary Dysplasia Treatment(MSBDT)trial is a single center,open-label,dose-escalation phase I clinical trial.Severe BPD patients were enrolled in Children Hospital of Chongqing Medical University,Chongqing,China.The first six patients were treated with low-dose hUC-MSCs(1×10^(6) cells/kg)and the next seven patients were treated with high-dose hUC-MSCs(5×10^(6) cells/kg).This study is registered with ClinicalTrials.gov,number NCT03558334.No prespecified infusion-associated adverse events,immediate complication,respiratory or cardiovascular compromise were observed during infusion and 24 h after infusion.No significant changes in safety laboratory values were observed.One death event occurred in the low-dose group on study day 10,and one death event occurred in the high-dose group on study day 24,while,after review in detail,the two cases are not believed to be infusion-associated events.In conclusion,intravenous application of a single dose of hUC-MSCs was tolerated in thirteen patients with severe BPD.

Efficacy of serum-free cultured human umbilical cord mesenchymal stem cells in the treatment of knee osteoarthritis in mice

BACKGROUND We investigated the efficacy of intra-articular injection of human umbilical cord mesenchymal stem cells(hUC-MSCs)for the treatment of osteoarthritis(OA)progression in the knee joint.Although many experimental studies of hUC-MSCs have been published,these studies have mainly used fetal bovine serumcontaining cultures of hUC-MSCs;serum-free cultures generally avoid the shortcomings of serum-containing cultures and are not subject to ethical limitations,have a wide range of prospects for clinical application,and provide a basis or animal experimentation for clinical experiments.AIM To study the therapeutic effects of serum-free hUC-MSCs(N-hUCMSCs)in a mouse model of knee OA.METHODS Fifty-five male C57BL/6 mice were randomly divided into six groups:The blank control group,model control group,serum-containing hUC-MSCs(S-hUCMSC)group,N-hUCMSC group and hyaluronic acid(HA)group.After 9 weeks of modeling,the serum levels of interleukin(IL)-1β and IL-1 were determined.Hematoxylin-eosin staining was used to observe the cartilage tissue,and the Mankin score was determined.Immunohistochemistry and western blotting were used to determine the expression of collagen type II,matrix metalloproteinase(MMP)-1 and MMP-13.RESULTS The Mankin score and serum IL-1 and IL-1β and cartilage tissue MMP-1 and MMP-13 expression were significantly greater in the experimental group than in the blank control group(P<0.05).Collagen II expression in the experimental group was significantly lower than that in the blank control group(P<0.05).The Mankin score and serum IL-1 and IL-1β and cartilage tissue MMP-1 and MMP-13 levels the experimental group were lower than those in the model control group(P<0.05).Collagen II expression in the experimental group was significantly greater than that in the model control group(P<0.05).CONCLUSION N-hUCMSC treatment significantly alleviate the pathological damage caused by OA.The treatment effects of the ShUCMSC group and HA group were similar.

Expansion of human umbilical cord derived mesenchymal stem cells in regenerative medicine

BACKGROUND Stem cells are undifferentiated cells that possess the potential for self-renewal with the capacity to differentiate into multiple lineages.In humans,their limited numbers pose a challenge in fulfilling the necessary demands for the regeneration and repair of damaged tissues or organs.Studies suggested that mesenchymal stem cells(MSCs),necessary for repair and regeneration via transplantation,require doses ranging from 10 to 400 million cells.Furthermore,the limited expansion of MSCs restricts their therapeutic application.AIM To optimize a novel protocol to achieve qualitative and quantitative expansion of MSCs to reach the targeted number of cells for cellular transplantation and minimize the limitations in stem cell therapy protocols.METHODS Human umbilical cord(hUC)tissue derived MSCs were obtained and re-cultured.These cultured cells were subjected to the following evaluation pro-cedures:Immunophenotyping,immunocytochemical staining,trilineage differentiation,population doubling time and number,gene expression markers for proliferation,cell cycle progression,senescence-associatedβ-galactosidase assay,human telomerase reverse transcriptase(hTERT)expression,mycoplasma,cytomegalovirus and endotoxin detection.RESULTS Analysis of pluripotent gene markers Oct4,Sox2,and Nanog in recultured hUC-MSC revealed no significant differences.The immunophenotypic markers CD90,CD73,CD105,CD44,vimentin,CD29,Stro-1,and Lin28 were positively expressed by these recultured expanded MSCs,and were found negative for CD34,CD11b,CD19,CD45,and HLA-DR.The recultured hUC-MSC population continued to expand through passage 15.Proliferative gene expression of Pax6,BMP2,and TGFb1 showed no significant variation between recultured hUC-MSC groups.Nevertheless,a significant increase(P<0.001)in the mitotic phase of the cell cycle was observed in recultured hUC-MSCs.Cellular senescence markers(hTERT expression andβ-galactosidase activity)did not show any negative effect on recultured hUC-MSCs.Additionally,quality control assessments consistently confirmed the absence of mycoplasma,cytomegalovirus,and endotoxin contamination.CONCLUSION This study proposes the development of a novel protocol for efficiently expanding stem cell population.This would address the growing demand for larger stem cell doses needed for cellular transplantation and will significantly improve the feasibility of stem cell based therapies.

Human umbilical cord mesenchymal stem cells derivedexosomes on VEGF-A in hypoxic-induced mice retinal astrocytes and mice model of retinopathy of prematurity

AIM:To observe the effect of human umbilical cord mesenchymal stem cells(hUCMSCs)secretions on the relevant factors in mouse retinal astrocytes,and to investigate the effect of hUCMSCs on the expression of vascular endothelial growth factor-A(VEGF-A)and to observe the therapeutic effect on the mouse model of retinopathy of prematurity(ROP).METHODS:Cultured hUCMSCs and extracted exosomes from them and then retinal astrocytes were divided into control group and hypoxia group.MTT assay,flow cytometry,reverse transcription-polymerase chain reaction(RT-PCR)and Western blot were used to detect related indicators.Possible mechanisms by which hUCMSCs exosomes affect VEGF-A expression in hypoxia-induced mouse retinal astrocytes were explored.At last,the efficacy of exosomes of UCMSCs in a mouse ROP model was explored.Graphpad6 was used to comprehensively process data information.RESULTS:The secretion was successfully extracted from the culture supernatant of hUCMSCs by gradient ultracentrifugation.Reactive oxygen species(ROS)and hypoxia inducible factor-1α(HIF-1α)of mice retinal astrocytes under different hypoxia time and the expression level of VEGF-A protein and VEGF-A mRNA increased,and the ROP cell model was established after 6h of hypoxia.The secretions of medium and high concentrations of hUCMSCs can reduce ROS and HIF-1α,the expression levels of VEGF-A protein and VEGF-A mRNA are statistically significant and concentration dependent.Compared with the ROP cell model group,the expression of phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)signal pathway related factors in the hUCMSCs exocrine group is significantly decreased.The intravitreal injection of the secretions of medium and high concentrations of hUCMSCs can reduce VEGF-A and HIF-1αin ROP model tissues.HE staining shows that the number of retinal neovascularization in ROP mice decreases with the increase of the dose of hUCMSCs secretion.CONCLUSION:In a hypoxia induced mouse retinal astrocyte model,hUCMSCs exosomes are found to effectively reduce the expression of HIF-1αand VEGF-A,which are positively correlated with the concentration of hUCMSCs exosomes.HUCMSCs exosomes can effectively reduce the number of retinal neovascularization and the expression of HIF-1αand VEGF-A proteins in ROP mice,and are positively correlated with drug dosage.Besides,they can reduce the related factors on the PI3K/AKT/mTOR signaling pathway.

Preliminary study on the preparation of lyophilized acellular nerve scaffold complexes from rabbit sciatic nerves with human umbilical cord mesenchymal stem cells

BACKGROUND The gold standard of care for patients with severe peripheral nerve injury is autologous nerve grafting;however,autologous nerve grafts are usually limited for patients because of the limited number of autologous nerve sources and the loss of neurosensory sensation in the donor area,whereas allogeneic or xenografts are even more limited by immune rejection.Tissue-engineered peripheral nerve scaffolds,with the morphology and structure of natural nerves and complex biological signals,hold the most promise as ideal peripheral nerve“replacements”.AIM To prepare allogenic peripheral nerve scaffolds using a low-toxicity decellularization method,and use human umbilical cord mesenchymal stem cells(hUCMSCs)as seed cells to cultivate scaffold-cell complexes for the repair of injured peripheral nerves.METHODS After obtaining sciatic nerves from New Zealand rabbits,an optimal acellular scaffold preparation scheme was established by mechanical separation,varying lyophilization cycles,and trypsin and DNase digestion at different times.The scaffolds were evaluated by hematoxylin and eosin(HE)and luxol fast blue(LFB)staining.The maximum load,durability,and elastic modulus of the acellular scaffolds were assessed using a universal material testing machine.The acellular scaffolds were implanted into the dorsal erector spinae muscle of SD rats and the scaffold degradation and systemic inflammatory reactions were observed at 3 days,1 week,3 weeks,and 6 weeks following surgery to determine the histocompatibility between xenografts.The effect of acellular scaffold extracts on fibroblast proliferation was assessed using an MTT assay to measure the cytotoxicity of the scaffold residual reagents.In addition,the umbilical cord from cesarean section fetuses was collected,and the Wharton’s jelly(WJ)was separated into culture cells and confirm the osteogenic and adipogenic differentiation of mesenchymal stem cells(MSCs)and hUC-MSCs.The cultured cells were induced to differentiate into Schwann cells by the antioxidant-growth factor induction method,and the differentiated cells and the myelinogenic properties were identified.RESULTS The experiments effectively decellularized the sciatic nerve of the New Zealand rabbits.After comparing the completed acellular scaffolds among the groups,the optimal decellularization preparation steps were established as follows:Mechanical separation of the epineurium,two cycles of lyophilization-rewarming,trypsin digestion for 5 hours,and DNase digestion for 10 hours.After HE staining,no residual nuclear components were evident on the scaffold,whereas the extracellular matrix remained intact.LFB staining showed a significant decrease in myelin sheath composition of the scaffold compared with that before preparation.Biomechanical testing revealed that the maximum tensile strength,elastic modulus,and durability of the acellular scaffold were reduced compared with normal peripheral nerves.Based on the histocompatibility test,the immune response of the recipient SD rats to the scaffold New Zealand rabbits began to decline3 weeks following surgery,and there was no significant rejection after 6 weeks.The MTT assay revealed that the acellular reagent extract had no obvious effects on cell proliferation.The cells were successfully isolated,cultured,and passaged from human umbilical cord WJ by MSC medium,and their ability to differentiate into Schwann-like cells was demonstrated by morphological and immunohistochemical identification.The differentiated cells could also myelinate in vitro.CONCLUSION The acellular peripheral nerve scaffold with complete cell removal and intact matrix may be prepared by combining lyophilization and enzyme digestion.The resulting scaffold exhibited good histocompatibility and low cytotoxicity.In addition,hUC-MSCs have the potential to differentiate into Schwann-like cells with myelinogenic ability following in vitro induction.

Effects of miR-214-5p and miR-21-5p in hypoxic endometrial epithelial-cell-derived exosomes on human umbilical cord mesenchymal stem cells

BACKGROUND Thin endometrium seriously affects endometrial receptivity,resulting in a significant reduction in embryo implantation,and clinical pregnancy and live birth rates,and there is no gold standard for treatment.The main pathophysiological characteristics of thin endometrium are increased uterine arterial blood flow resistance,angiodysplasia,slow growth of the glandular epithelium,and low expression of vascular endothelial growth factor,resulting in endometrial epithelial cell(EEC)hypoxia and endometrial tissue aplasia.Human umbilical cord mesenchymal stem cells(HucMSCs)promote repair and regeneration of damaged endometrium by secreting microRNA(miRNA)-carrying exosomes.However,the initiation mechanism of HucMSCs to repair thin endometrium has not yet been clarified.AIM To determine the role of hypoxic-EEC-derived exosomes in function of HucMSCs and explore the potential mechanism.METHODS Exosomes were isolated from normal EECs(EEC-exs)and hypoxia-damaged EECs(EECD-exs),before characterization using Western blotting,nanoparticletracking analysis,and transmission electron microscopy.HucMSCs were cocultured with EEC-exs or EECD-exs and differentially expressed miRNAs were determined using sequencing.MiR-21-5p or miR-214-5p inhibitors or miR-21-3p or miR-214-5p mimics were transfected into HucMSCs and treated with a signal transducer and activator of transcription 3(STAT3)activator or STAT3 inhibitor.HucMSC migration was assessed by Transwell and wound healing assays.Differentiation of HucMSCs into EECs was assessed by detecting markers of stromal lineage(Vimentin and CD13)and epithelial cell lineage(CK19 and CD9)using Western blotting and immunofluorescence.The binding of the miRNAs to potential targets was validated by dual-luciferase reporter assay.RESULTS MiR-21-5p and miR-214-5p were lowly expressed in EECD-ex-pretreated HucMSCs.MiR-214-5p and miR-21-5p inhibitors facilitated the migratory and differentiative potentials of HucMSCs.MiR-21-5p and miR-214-5p targeted STAT3 and protein inhibitor of activated STAT3,respectively,and negatively regulated phospho-STAT3.MiR-21-5p-and miR-214-5p-inhibitor-induced promotive effects on HucMSC function were reversed by STAT3 inhibition.MiR-21-5p and miR-214-5p overexpression repressed HucMSC migration and differentiation,while STAT3 activation reversed these effects.CONCLUSION Low expression of miR-21-5p/miR-214-5p in hypoxic-EEC-derived exosomes promotes migration and differentiation of HucMSCs into EECs via STAT3 signaling.Exosomal miR-214-5p/miR-21-5p may function as valuable targets for thin endometrium.

Human umbilical cord mesenchymal stem cell-derived exosomes loaded into a composite conduit promote functional recovery after peripheral nerve injury in rats

Complete transverse injury of peripheral nerves is challenging to treat.Exosomes secreted by human umbilical cord mesenchymal stem cells are considered to play an important role in intercellular communication and regulate tissue regeneration.In previous studies,a collagen/hyaluronic acid sponge was shown to provide a suitable regeneration environment for Schwann cell proliferation and to promote axonal regeneration.This three-dimensional(3D)composite conduit contains a collagen/hyaluronic acid inner sponge enclosed in an electrospun hollow poly(lactic-co-glycolic acid)tube.However,whether there is a synergy between the 3D composite conduit and exosomes in the repair of peripheral nerve injury remains unknown.In this study,we tested a comprehensive strategy for repairing long-gap(10 mm)peripheral nerve injury that combined the 3D composite conduit with human umbilical cord mesenchymal stem cell-derived exosomes.Repair effectiveness was evaluated by sciatic functional index,sciatic nerve compound muscle action potential recording,recovery of muscle mass,measuring the cross-sectional area of the muscle fiber,Masson trichrome staining,and transmission electron microscopy of the regenerated nerve in rats.The results showed that transplantation of the 3D composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes promoted peripheral nerve regeneration and restoration of motor function,similar to autograft transplantation.More CD31-positive endothelial cells were observed in the regenerated nerve after transplantation of the loaded conduit than after transplantation of the conduit without exosomes,which may have contributed to the observed increase in axon regeneration and distal nerve reconnection.Therefore,the use of a 3D composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes represents a promising cell-free therapeutic option for the treatment of peripheral nerve injury.

Capacity of human umbilical cord-derived mesenchymal stem cells to differentiate into sweat gland-like cells:a preclinical study

Human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)possess various advantageous properties,including self-renewal,extended proliferation potential,multi-lineage differentiation potential and capacity for differentiating into sweat gland-like cells in certain conditions.However,little is known about the effect of clinical-grade culture conditions on these properties and on the differentiative potential of hUC-MSCs.In this study,we sought to investigate the properties of hUC-MSCs expanded with animal serum free culture media(ASFCM)in order to determine their potential for differentiation into sweat gland-like cells.We found that primary cultures of hUC-MSCs could be established with ASFCM.Moreover,cells cultured in ASFCM showed vigorous proliferation comparable to those of cells grown in classical culture conditions containing fetal bovine serum(FBS).Morphology of hUC-MSCs cultured in ASFCM was comparable to those of cells grown under classical culture conditions,and hUC-MSCs grown in both of the two culture conditions tested showed the typical antigen profile of MSCs—positive for CD29,CD44,CD90,and CD105,and negative for CD34 and CD45,as expected.Chromosomal aberration assay revealed that the cells were stable after long-term culture under both culture conditions.Like normal cultured MSCs,hUC-MSCs induced under ASFCM conditions exhibited expression of the same markers(CEA,CK14 and CK19)and developmental genes(EDA and EDAR)that are characteristic of normal sweat gland cells.Taken together,our findings indicate that the classical culture medium used to differentiate hUC-MSCs into sweat gland-like cells can be replaced safely by ASFCM for clinical purposes.

Human umbilical cord mesenchymal stem cells promote peripheral nerve repair via paracrine mechanisms

Human umbilical cord-derived mesenchymal stem cells （hUCMSCs） represent a promising young-state stem cell source for cell-based therapy. hUCMSC transplantation into the transected sciatic nerve promotes axonal regeneration and functional recovery. To further clarify the para-crine effects of hUCMSCs on nerve regeneration, we performed human cytokine antibody array analysis, which revealed that hUCMSCs express 14 important neurotrophic factors. Enzyme-linked immunosorbent assay and immunohistochemistry showed that brain-derived neurotrophic factor, glial-derived neurotrophic factor, hepatocyte growth factor, neurotrophin-3, basic fibroblast growth factor, type I collagen, fibronectin and laminin were highly expressed. Treatment with hUCMSC-conditioned medium enhanced Schwann cell viability and proliferation, increased nerve growth factor and brain-derived neurotrophic factor expression in Schwann cells, and enhanced neurite growth from dorsal root ganglion explants. These ifndings suggest that paracrine action may be a key mechanism underlying the effects of hUCMSCs in peripheral nerve repair.

Comparative breakthrough: Umbilical cord mesenchymal stem cells vs bone marrow mesenchymal stem cells in heart failure treatment

In this article,we evaluate the comparative efficacy and safety of mesenchymal stem cells(MSCs)derived from bone marrow(BM-MSCs)and umbilical cord(UC-MSCs)in the treatment of heart failure and myocardial infarction.MSCs have gained importance as living bio drug due to their regenerative potential,with BM-MSCs being the most extensively studied.However,UC-MSCs offer unique advantages,such as noninvasive collection and fewer ethical concerns.This systematic review and meta-analysis summarizes data from 13 randomized controlled trials,which included a total of 693 patients.Their study shows that UC-MSCs significantly improved left ventricular ejection fraction by 5.08%at 6 months and 2.78%at 12 months compared with controls,while BM-MSCs showed no significant effect.Neither cell type showed significant changes in 6-minute walk distance.In addition,UC-MSCs and BM-MSCs had comparable safety profiles,with no significant differences in major adverse cardiac events,except for a lower rehospitalization rate observed with BM-MSCs.These results position UC-MSCs as a promising alternative in MSC-based therapies for cardiac disease,offering potential improvements in cardiac function while maintaining a favorable safety profile.Future research should focus on optimizing adminis-tration protocols and further exploring the long-term benefits and mechanisms of UC-MSCs in cardiac repair.

Umbilical cord mesenchymal stem cell exosomes alleviate necrotizing enterocolitis in neonatal mice by regulating intestinal epithelial cells autophagy

BACKGROUND Necrotizing enterocolitis(NEC)is a severe gastrointestinal disease that affects premature infants.Although mounting evidence supports the therapeutic effect of exosomes on NEC,the underlying mechanisms remain unclear.AIM To investigate the mechanisms underlying the regulation of inflammatory response and intestinal barrier function by umbilical cord mesenchymal stem cell(UCMSCs)exosomes,as well as their potential in alleviating NEC in neonatal mice.METHODS NEC was induced in 5-d-old C57BL/6 pups through hypoxia and gavage feeding of formula containing lipopolysaccharide(LPS),after which the mice received human UCMSC exosomes(hUCMSC-exos).The control mice were allowed to breastfeed with their dams.Ileal tissues were collected from the mice and analyzed by histopathology and immunoblotting.Colon tissues were collected from NEC neonates and analyzed by immunofluorescence.Molecular biology and cell culture approaches were employed to study the related mechanisms in intestinal epithelial cells.RESULTS We found that autophagy is overactivated in intestinal epithelial cells during NEC,resulting in reduced expression of tight junction proteins and an increased inflammatory response.The ability of hUCMSC-exos to ameliorate NEC in a mouse model was dependent on decreased intestinal autophagy.We also showed that hUCMSC-exos alleviate the inflammatory response and increase migration ability in intestinal epithelial cells induced by LPS.CONCLUSION These results contribute to a better understanding of the protective mechanisms of hUCMSC-exos against NEC and provide a new theoretical and experimental foundation for NEC treatment.These findings also enhance our understanding of the role of the autophagy mechanism in NEC,offering potential avenues for identifying new therapeutic targets.

WJSC 6^(th) Anniversary Special Issues(2):Mesenchymal stem cells Umbilical cord-derived mesenchymal stem cells:Their advantages and potential clinical utility

Human umbilical cord(UC)is a promising source of mesenchymal stem cells(MSCs).Apart from their prominent advantages,such as a painless collection procedure and faster self-renewal,UC-MSCs have shown the ability to differentiate into three germ layers,to accumulate in damaged tissue or inflamed regions,to promote tissue repair,and to modulate immune response.There are diverse protocols and culture methods for the isolation of MSCs from the various compartments of UC,such as Wharton’s jelly,vein,arteries,UC lining and subamnion and perivascular regions.In this review,we give a brief introduction to various compartments of UC as a source of MSCs and emphasize the potential clinical utility of UC-MSCs for regenerative medicine and immunotherapy.