Neural differentiation of human placenta-derived mesenchymal stem cells following neural cell co-culture

We induced human placenta-derived mesenchymal stem cells （hPMSCs） to differentiate into neural cells by adding chemical reagents, despite the fact that toxic chemicals induce cell shrinkage or cytoskeletal formation, which does not represent a proper cell differentiation process. The present study established a co-culture system with hPMSCs and neural cells and analyzed the influence of neural cells on hPMSC differentiation in a co-culture system, hPMSCs were isolated and purified from human full-term placenta using collagenase digestion. Fetal neural cells were co-cultured with hPMSCs for 48 hours using the Transwell co-culture system, hPMSCs co-cultured with neural cells exhibited a slender morphology with a filament. After 96 hours, hPMSCs expressed neuron-specific enolase, which suggested that co-culture of hPMSCs and neural cells induced neural differentiation of hPMSCs.

Uric acid promotes neuronal differentiation of human placenta-derived mesenchymal stem cells in a time- and concentration-dependent manner

Uric acid is an important, naturally occurring serum antioxidant. The present study investigates the use of uric acid for promoting proliferation and neuronal differentiation of mesenchymal stem cells derived from human placenta tissue. Human placenta-derived mesenchymal stem cells were pre-induced in the presence of either 0, 0.2, 0.4 or 0.8 mM uric acid in combination with 1 mM β-mercaptoethanol for 24 hours, followed by exposure to identical uric acid concentrations and 5 mM β-mercaptoethanol for 6 and 10 hours. Cells developed a neuronal-like morphology, with formation of interconnected process extensions, typical of neural cells. Immunocytochemistry and immunofluorescence staining showed neuron specific enolase positive cells were present in each group except the control group. A greater number of neuron specific enolase positive cells were observed in 0.8 mM uric acid in combination with 5 mM β-mercaptoethanol at 10 hours. After 24 hours of induction, Nissl bodies were detected in the cytoplasm of all differentiated cell groups except the control group and Nissl body numbers were greatest in human placenta-derived mesenchymal stem cells grown in the presence of 0.8 mM uric acid and 5 mM β-mercaptoethanol. These results suggest uric acid accelerates differentiation of human placenta-derived mesenchymal stem cells into neuronal-like cells in a time-and concentration-dependent manner.

Identification of tumorigenic risk genes in human placenta-derived mesenchymal stem cells treated with 3-methylcholanthrene

Mesenchymal stem cells(MSCs)capable of tumour topotaxis have been served as cellular vehicles to deliver anti-tumour agents.As cellular components of the tumour microenvironment,MSCs also affect tumour progression.However,the tumour transformation-related genes of MSCs remain unclear since either tumorigenic or tumour suppressor effects within these cells have been researched.Hence,we aimed to identify potential biomarkers indicative of tumorigenic risk by RNA-seq analysis of human placenta tissue-derived MSCs(hPTMSCs)exposed to the carcinogenic agent,3-methylcholanthrene(3-MC).Twenty-nine tumour transformation-related genes and three pluripotency-related genes were appraised as differentially expressed genes(DEGs)in hPTMSCs.Overexpression of sfrp1 led to reduced cell viability,migration,and colony formation in A549.In contrast,the overexpression of ptgs2 exerted the opposite effect.These results indicate that A549 cells with high ptgs2 expression but low sfrp1 expression may have a more potential tumorigenic capacity.Taken together,this study suggests that ptgs2 and sfrp1 may be tumorigenic risk genes.

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.

Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.

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.

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.

Effects of leptin-modified human placenta-derived mesenchymal stem cells on angiogenic potential and peripheral inflammation of human umbilical vein endothelial cells(HUVECs) after X-ray radiation

Combined radiation-wound injury(CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells(HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells(HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8(CCK-8) assay. The secretion of pro-inflammatory cytokines(human granulocyte macrophage-colony stimulating factor(GM-CSF), interleukin(IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay(ELISA). The expression of pro-angiogenic factors(vascular endothelial growth factor(VEGF) and basic fibroblast growth factor(b FGF)) mRNA was detected by real-time quantitative polymerase chain reaction(RT-qPCR) assay. Relevant molecules of the nuclear factor-κB(NF-κB) and Janus kinase(JAK)/signal transducer and activator of transcription(STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs(HPMSCs/leptin) exhibited better cell proliferation, migration, and angiogenic potential(expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines(human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.

Dissecting molecular mechanisms underlying ferroptosis in human umbilical cord mesenchymal stem cells:Role of cystathionineγ-lyase/hydrogen sulfide pathway

BACKGROUND Ferroptosis can induce low retention and engraftment after mesenchymal stem cell(MSC)delivery,which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension(PAH)therapy.Interestingly,the cystathionineγ-lyase(CSE)/hydrogen sulfide(H_(2)S)pathway may contribute to mediating ferroptosis.However,the influence of the CSE/H_(2)S pathway on ferroptosis in human umbilical cord MSCs(HUCMSCs)remains unclear.AIM To clarify whether the effect of HUCMSCs on vascular remodelling in PAH mice is affected by CSE/H_(2)S pathway-mediated ferroptosis,and to investigate the functions of the CSE/H_(2)S pathway in ferroptosis in HUCMSCs and the underlying mechanisms.METHODS Erastin and ferrostatin-1(Fer-1)were used to induce and inhibit ferroptosis,respectively.HUCMSCs were transfected with a vector to overexpress or inhibit expression of CSE.A PAH mouse model was established using 4-wk-old male BALB/c nude mice under hypoxic conditions,and pulmonary pressure and vascular remodelling were measured.The survival of HUCMSCs after delivery was observed by in vivo bioluminescence imaging.Cell viability,iron accumulation,reactive oxygen species production,cystine uptake,and lipid peroxidation in HUCMSCs were tested.Ferroptosis-related proteins and S-sulfhydrated Kelchlike ECH-associating protein 1(Keap1)were detected by western blot analysis.RESULTS In vivo,CSE overexpression improved cell survival after erastin-treated HUCMSC delivery in mice with hypoxiainduced PAH.In vitro,CSE overexpression improved H_(2)S production and ferroptosis-related indexes,such as cell viability,iron level,reactive oxygen species production,cystine uptake,lipid peroxidation,mitochondrial membrane density,and ferroptosis-related protein expression,in erastin-treated HUCMSCs.In contrast,in vivo,CSE inhibition decreased cell survival after Fer-1-treated HUCMSC delivery and aggravated vascular remodelling in PAH mice.In vitro,CSE inhibition decreased H_(2)S levels and restored ferroptosis in Fer-1-treated HUCMSCs.Interestingly,upregulation of the CSE/H_(2)S pathway induced Keap1 S-sulfhydration,which contributed to the inhibition of ferroptosis.CONCLUSION Regulation of the CSE/H_(2)S pathway in HUCMSCs contributes to the inhibition of ferroptosis and improves the suppressive effect on vascular remodelling in mice with hypoxia-induced PAH.Moreover,the protective effect of the CSE/H_(2)S pathway against ferroptosis in HUCMSCs is mediated via S-sulfhydrated Keap1/nuclear factor erythroid 2-related factor 2 signalling.The present study may provide a novel therapeutic avenue for improving the protective capacity of transplanted MSCs in PAH.

Zinc enhances the cell adhesion,migration,and self-renewal potential of human umbilical cord derived mesenchymal stem cells

BACKGROUND Zinc(Zn)is the second most abundant trace element after Fe,present in the human body.It is frequently reported in association with cell growth and proliferation,and its deficiency is considered to be a major disease contributing factor.AIM To determine the effect of Zn on in vitro growth and proliferation of human umbilical cord(hUC)-derived mesenchymal stem cells(MSCs).METHODS hUC-MSCs were isolated from human umbilical cord tissue and characterized based on immunocytochemistry,immunophenotyping,and tri-lineage differentiation.The impact of Zn on cytotoxicity and proliferation was determined by MTT and Alamar blue assay.To determine the effect of Zn on population doubling time(PDT),hUC-MSCs were cultured in media with and without Zn for several passages.An in vitro scratch assay was performed to analyze the effect of Zn on the wound healing and migration capability of hUC-MSCs.A cell adhesion assay was used to test the surface adhesiveness of hUC-MSCs.Transcriptional analysis of genes involved in the cell cycle,proliferation,migration,and selfrenewal of hUC-MSCs was performed by quantitative real-time polymerase chain reaction.The protein expression of Lin28,a pluripotency marker,was analyzed by immunocytochemistry.RESULTS Zn at lower concentrations enhanced the rate of proliferation but at higher concentrations(>100μM),showed concentration dependent cytotoxicity in hUC-MSCs.hUC-MSCs treated with Zn exhibited a significantly greater healing and migration rate compared to untreated cells.Zn also increased the cell adhesion rate,and colony forming efficiency(CFE).In addition,Zn upregulated the expression of genes involved in the cell cycle(CDC20,CDK1,CCNA2,CDCA2),proliferation(transforming growth factorβ1,GDF5,hypoxia-inducible factor 1α),migration(CXCR4,VCAM1,VEGF-A),and self-renewal(OCT4,SOX2,NANOG)of hUC-MSCs.Expression of Lin28 protein was significantly increased in cells treated with Zn.CONCLUSION Our findings suggest that zinc enhances the proliferation rate of hUC-MSCs decreasing the PDT,and maintaining the CFE.Zn also enhances the cell adhesion,migration,and self-renewal of hUC-MSCs.These results highlight the essential role of Zn in cell growth and development.

Interferon-gamma and tumor necrosis factor-alpha synergistically enhance the immunosuppressive capacity of human umbilical-cordderived mesenchymal stem cells by increasing PD-L1 expression

BACKGROUND The immunosuppressive capacity of mesenchymal stem cells(MSCs)is dependent on the“license”of several proinflammatory factors to express immunosuppressive factors such as programmed cell death 1 ligand 1(PD-L1),which determines the clinical therapeutic efficacy of MSCs for inflammatory or immune diseases.In MSCs,interferon-gamma(IFN-γ)is a key inducer of PD-L1 expression,which is synergistically enhanced by tumor necrosis factor-alpha(TNF-α);however,the underlying mechanism is unclear.AIM To reveal the mechanism of pretreated MSCs express high PD-L1 and explore the application of pretreated MSCs in ulcerative colitis.METHODS We assessed PD-L1 expression in human umbilical-cord-derived MSCs(hUC-MSCs)induced by IFN-γand TNF-α,alone or in combination.Additionally,we performed signal pathway inhibitor experiments as well as RNA interference experiments to elucidate the molecular mechanism by which IFN-γalone or in combination with TNF-αinduces PD-L1 expression.Moreover,we used luciferase reporter gene experiments to verify the binding sites of the transcription factors of each signal transduction pathway to the targeted gene promoters.Finally,we evaluated the immunosuppressive capacity of hUC-MSCs treated with IFN-γand TNF-αin both an in vitro mixed lymphocyte culture assay,and in vivo in mice with dextran sulfate sodium-induced acute colitis.RESULTS Our results suggest that IFN-γinduction alone upregulates PD-L1 expression in hUC-MSCs while TNF-αalone does not,and that the co-induction of IFN-γand TNF-αpromotes higher expression of PD-L1.IFN-γinduces hUCMSCs to express PD-L1,in which IFN-γactivates the JAK/STAT1 signaling pathway,up-regulates the expression of the interferon regulatory factor 1(IRF1)transcription factor,promotes the binding of IRF1 and the PD-L1 gene promoter,and finally promotes PD-L1 mRNA.Although TNF-αalone did not induce PD-L1 expression in hUCMSCs,the addition of TNF-αsignificantly enhanced IFN-γ-induced JAK/STAT1/IRF1 activation.TNF-αupregulated IFN-γreceptor expression through activation of the nuclear factor kappa-B signaling pathway,which significantly enhanced IFN-γsignaling.Finally,co-induced hUC-MSCs have a stronger inhibitory effect on lymphocyte proliferation,and significantly ameliorate weight loss,mucosal damage,inflammatory cell infiltration,and up-regulation of inflammatory factors in colitis mice.CONCLUSION Overall,our results suggest that IFN-γand TNF-αenhance both the immunosuppressive ability of hUC-MSCs and their efficacy in ulcerative colitis by synergistically inducing high expression of PD-L1.

Injectable collagen scaffold with human umbilical cordderived mesenchymal stem cells promotes functional recovery in patients with spontaneous intracerebral hemorrhage:phase Ⅰ clinical trial

Animal expe riments have shown that injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells can promote recovery from spinal cord injury.To investigate whether injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells can be used to treat spontaneous intracerebral hemorrhage,this non-randomized phase I clinical trial recruited patients who met the inclusion criteria and did not meet the exclusion crite ria of spontaneous intracerebral hemorrhage treated in the Characteristic Medical Center of Chinese People’s Armed Police Force from May 2016 to December 2020.Patients were divided into three groups according to the clinical situation and patient benefit:control(n=18),human umbilical cord-derived mesenchymal stem cells(n=4),and combination(n=8).The control group did not receive any transplantation.The human umbilical cord-derived mesenchymal stem cells group received human umbilical cord-derived mesenchymal stem cell transplantation.The combination group received injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells.Patients who received injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells had more remarkable improvements in activities of daily living and cognitive function and smaller foci of intra cerebral hemorrhage-related encephalomalacia.Severe adve rse events associated with cell transplantation were not observed.Injectable collagen scaffold with human umbilical cord-derived mesenchymal stem cells appears to have great potential treating spontaneous intracerebral hemorrhage.

Enhanced wound healing and hemostasis with exosome-loaded gelatin sponges from human umbilical cord mesenchymal stem cells

BACKGROUND Rapid wound healing remains a pressing clinical challenge,necessitating studies to hasten this process.A promising approach involves the utilization of human umbilical cord mesenchymal stem cells(hUC-MSCs)derived exosomes.The hypothesis of this study was that these exosomes,when loaded onto a gelatin sponge,a common hemostatic material,would enhance hemostasis and accelerate wound healing.AIM To investigate the hemostatic and wound healing efficacy of gelatin sponges loaded with hUC-MSCs-derived exosomes.METHODS Ultracentrifugation was used to extract exosomes from hUC-MSCs.Nanoparticle tracking analysis(NTA),transmission electron microscopy(TEM),and western blot techniques were used to validate the exosomes.In vitro experiments were performed using L929 cells to evaluate the cytotoxicity of the exosomes and their impact on cell growth and survival.New Zealand rabbits were used for skin irritation experiments to assess whether they caused adverse skin reactions.Hemolysis test was conducted using a 2%rabbit red blood cell suspension to detect whether they caused hemolysis.Moreover,in vivo experiments were carried out by implanting a gelatin sponge loaded with exosomes subcutaneously in Sprague-Dawley(SD)rats to perform biocompatibility tests.In addition,coagulation index test was conducted to evaluate their impact on blood coagulation.Meanwhile,SD rat liver defect hemostasis model and full-thickness skin defect model were used to study whether the gelatin sponge loaded with exosomes effectively stopped bleeding and promoted wound healing.RESULTS The NTA,TEM,and western blot experimental results confirmed that exosomes were successfully isolated from hUC-MSCs.The gelatin sponge loaded with exosomes did not exhibit significant cell toxicity,skin irritation,or hemolysis,and they demonstrated good compatibility in SD rats.Additionally,the effectiveness of the gelatin sponge loaded with exosomes in hemostasis and wound healing was validated.The results of the coagulation index experiment indicated that the gelatin sponge loaded with exosomes had significantly better coagulation effect compared to the regular gelatin sponge,and they showed excellent hemostatic performance in a liver defect hemostasis model.Finally,the full-thickness skin defect healing experiment results showed significant improvement in the healing process of wounds treated with the gelatin sponge loaded with exosomes compared to other groups.CONCLUSION Collectively,the gelatin sponge loaded with hUC-MSCs-derived exosomes is safe and efficacious for promoting hemostasis and accelerating wound healing,warranting further clinical application.

Effect of Human Umbilical Cord Mesenchymal Stem Cells on GRP78/ATF4 Pathway in Alzheimer s Disease Model Mice

[Objectives]To study the effect of human umbilical cord mesenchymal stem cells(hUC-MSCs)on GRP78/ATF4 pathway in APP/PS1 mice.[Methods]Twelve 6-month-old female APP/PS1 mice were randomly divided into model group(MOD,n=6)and human umbilical cord mesenchymal stem cell treatment group(MSC,n=6);six 6-month-old C57BL/6N mice were used as control group(CON,n=6).The mice in each group were treated with the fourth generation of human umbilical cord mesenchymal stem cells through tail vein.Four weeks later,the mice in each group were killed.The expression of GFP78 and ATF4 in the cortex of mice in each group was detected by Western blotting and real-time fluorescence quantitative PCR.[Results]The results of immunoblotting and real-time fluorescence quantitative PCR showed that the expression of GRP78 in MOD group was lower than that in CON group and the expression of ATF4 increased.The expression of GRP78 protein in MSC group was higher than that in MOD group,but the expression of ATF4 protein was lower.The results of real-time fluorescence quantitative PCR showed that the mRNA level of GRP78 decreased and the mRNA level of ATF4 increased in MOD group compared with CON group.The mRNA level of GRP78 in MSC group was higher than that in MOD group,while the mRNA level of ATF4 in MSC group was lower than that in MOD group.[Conclusions]Human umbilical cord mesenchymal stem cells can regulate the expression of GRP78/ATF4 pathway in APP/PSI mice,which may be related to the stress level of endoplasmic reticulum in the brain of APP/PS1 mice mediated by human umbilical cord mesenchymal stem cells.

Exploring the Mechanism of CircRNA-vgll3 in Osteogenically Differentiated Human Bone Marrow Mesenchymal Stem Cells

Objective:To explore the mechanism of circRNA-vgll3 in osteogenic differentiation of human bone marrow mesenchymal stem cells.Methods:BMSCs cells were transfected with circRNA-vgll3,and divided into circRNA-vgll3 high-level group,circRNA-vgll3 low-level group,and negative control group(circRNA-vgll3 not transfected)according to the amount of transfection.The proliferation and apoptosis of BMSCs osteoblasts in each group were analyzed,and the alkaline phosphatase(ALP)activity,type I collagen gray value,bone morphogenetic protein 2(BMP-2),Runx2 protein,and mRNA expression levels were detected.Results:The circRNA-vgll3 low-level group had a significant inhibitory effect on the proliferation of BMSCs osteoblasts,and the apoptosis rate of the circRNA-vgll3 low-level group was significantly higher than that of the circRNA-vgll3 high-level group(P<0.05);ALP activity,type I collagen gray value,BMP-2,Runx2 protein,and mRNA expression levels in the high-level circRNA-vgll3 group were significantly higher than those in the low-level circRNA-vgll3 group,and the difference was statistically significant(P<0.05).Conclusion:Overexpression of circRNA-vgll3 can promote the osteogenic differentiation ability of BMSCs,while low expression of circRNA-vgll3 can inhibit the osteogenic differentiation ability of BMSCs.The main mechanism of action is that circRNA-vgll3 can affect osteogenic differentiation by regulating the Runx2 protein.

Transplantation of placenta-derived mesenchymal stem cell-induced neural stem cells to treat spinal cord injury

Because of their strong proliferative capacity and multi-potency, placenta-derived mesenchymal stem cells have gained interest as a cell source in the field of nerve damage repair. In the present study, human placenta-derived mesenchymal stem ceils were induced to differentiate into neural stem cells, which were then transplanted into the spinal cord after local spinal cord injury in rats. The motor functional recovery and pathological changes in the injured spinal cord were observed for 3 successive weeks. The results showed that human placenta-derived mesenchymal stem cells can differentiate into neuron-like cells and that induced neural stem cells contribute to the restoration of injured spinal cord without causing transplant rejection. Thus, these cells promote the recovery of motor and sensory functions in a rat model of spinal cord injury. Therefore, human placenta-derived mesenchymal stem cells may be useful as seed cells during the repair of spinal cord injury.

Long non-coding RNA SNHG16 promotes human placenta-derived mesenchymal stem cell proliferation capacity through the PI3K/AKT pathway under hypoxia

BACKGROUND The effect of hypoxia on mesenchymal stem cells(MSCs)is an emerging topic in MSC biology.Although long non-coding RNAs(lncRNAs)and messenger RNAs(mRNAs)are reported to play a critical role in regulating the biological characteristics of MSCs,their specific expression and co-expression profiles in human placenta-derived MSCs(hP-MSCs)under hypoxia and the underlying mechanisms of lncRNAs in hP-MSC biology are unknown.AIM To reveal the specific expression profiles of lncRNAs in hP-MSCs under hypoxia and initially explored the possible mechanism of lncRNAs on hP-MSC biology.METHODS Here,we used a multigas incubator(92.5%N_(2),5%CO_(2),and 2.5%O_(2))to mimic the potential of hP-MSCs.RNA sequencing technology was applied to identify the exact expression profiles of lncRNAs and mRNAs under hypoxia.RESULTS We identified 289 differentially expressed lncRNAs and 240 differentially expressed mRNAs between the hypoxia and normoxia groups.Among them,the lncRNA SNHG16 was upregulated under hypoxia,which was also validated by reverse transcription-polymerase chain reaction.SNHG16 was confirmed to affect hP-MSC proliferation rates using a SNHG16 knockdown model.SNHG16 overexpression could significantly enhance the proliferation capacity of hP-MSCs,activate the PI3K/AKT pathway,and upregulate the expression of cell cycle-related proteins.CONCLUSION Our results revealed the specific expression characteristics of lncRNAs and mRNAs in hypoxiacultured hP-MSCs and that lncRNA SNHG16 can promote hP-MSC proliferation through the PI3K/AKT pathway.

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.

Human umbilical cord mesenchymal stem cells as treatment of adjuvant rheumatoid arthritis in a rat model

AIM:To investigate the effect of human umbilical cord stem cells,both mesenchymal and hematopoietic(CD34+),in the treatment of arthritis.METHODS:Mesenchymal stem cells(MSCs) and hematopoietic(CD34+) stem cells(HSC) were isolated from human umbilical cord blood obtained from the umbilical cord of healthy pregnant donors undergoing fullterm normal vaginal delivery.MSC,HSC,methotrexate(MTX) and sterile saline were injected intra-articularly into the rat hindpaw with complete freunds adjuvant(CFA) induced arthritis after the onset of disease(day 34),when arthritis had become well established(arthritis score ≥ 2).Arthritic indices were evaluated and the levels of interleukin(IL)-1,tumor necrosis factor(TNF)-α and interferon(IFN)-γ and anti-inflammatory cytokine IL-10 in serum were determined using enzyme-linked immunosorbent assay.Animals of all groups were sacrificed 34 d after beginning treatment,except positive control(PC) which was sacrificed at 10,21 and 34 d for microscopic observation of disease progression.We used hematoxylin,eosin and Masson's trichrome stains for histopathological examination of cartilage and synovium.RESULTS:The mean arthritis scores were similar in all groups at 12 and 34 d post immunization,with no statistical significant difference.Upon the injection of stem cells(hematopoietic and mesenchymal),the overall arthritis signs were significantly improved around 21 d after receiving the injection and totally disappeared at day 34 post treatment in MSC group.Mean hindpaw diameter(mm) in the MSC rats was about half that of the PC and MTX groups(P = 0.007 and P = 0.021,respectively) and 0.6 mm less than the HSC group(P = 0.047),as indicated by paw swelling.Associated with these findings,serum levels of TNF-α,IFN-γ and IL-1 decreased significantly in HSC and MSC groups compared to PC and MTX groups(P < 0.05),while the expression of IL-10 was increased.Histopathological examination with H and E stain revealed that the MTX treated group showed significant reduction of leucocytic infiltrate and hypertrophy of the synovial tissue with moderate obliteration of the joint cavity.Stem cells treated groups(both hematopoietic CD34+ and mesenchymal),showed significant reduction in leucocytic infiltrate and hypertrophy of the synovial tissue with mild obliteration of the joint cavity.With Masson's trichrome,stain sections from the PC group showed evidence of vascular edema of almost all vessels within the synovium in nearly all arthritic rats.Vacuoles were also visible in the outer vessel wall.The vessel became hemorrhagic and finally necrotic.In addition,there was extensive fibrosis completely obliterating the joint cavity.The mean color area percentage of collagen in this group was 0.324 ± 0.096,which was significantly increased when compared to the negative control group.The mean color area percentage of collagen in hematopoietic CD34+ and mesenchymal groups was 0.176 ± 0.0137 and 0.174 ± 0.0197 respectively,which showed a marked decrement compared to the PC group,denoting a mild increase in synovial tissue collagen fibers.CONCLUSION:MSC enhance the efficacy of CFAinduced arthritis treatment,most likely through the modulation of the expression of cytokines and amelioration of pathological changes in joints.