Safety evaluation of human umbilical cord-mesenchymal stem cells in type 2 diabetes mellitus treatment:A phase 2 clinical trial

BACKGROUND Progressive pancreaticβcell dysfunction is a fundamental aspect of the pathology underlying type 2 diabetes mellitus(T2DM).Recently,mesenchymal stem cell(MSC)transplantation has emerged as a new therapeutic method due to its ability to promote the regeneration of pancreaticβcells.However,current studies have focused on its efficacy,and there are few clinical studies on its safety.AIM To evaluate the safety of human umbilical cord(hUC)-MSC infusion in T2DM treatment.METHODS An open-label and randomized phase 2 clinical trial was designed to evaluate the safety of hUC-MSC transplantation in T2DM in a Class A hospital.Ten patients in the placebo group received acellular saline intravenously once per week for 3 wk.Twenty-four patients in the hUC-MSC group received hUC-MSCs(1×106 cells/kg)intravenously once per week for 3 wk.Diabetic clinical symptoms and signs,laboratory findings,and imaging findings were evaluated weekly for the 1st mo and then at weeks 12 and 24 post-treatment.RESULTS No serious adverse events were observed during the 24-wk follow-up.Four patients(16.7%)in the hUC-MSC group experienced transient fever,which occurred within 24 h after the second or third infusion;this did not occur in any patients in the placebo group.One patient from the hUC-MSC group experienced hypoglycemic attacks within 1 mo after transplantation.Significantly lower lymphocyte levels(weeks 2 and 3)and thrombin coagulation time(week 2)were observed in the hUC-MSC group compared to those in the placebo group(all P<0.05).Significantly higher platelet levels(week 3),immunoglobulin levels(weeks 1,2,3,and 4),fibrinogen levels(weeks 2 and 3),D-dimer levels(weeks 1,2,3,4,12,and 24),and neutrophil-to-lymphocyte ratios(weeks 2 and 3)were observed in the hUC-MSC group compared to those in the placebo group(all P<0.05).There were no significant differences between the two groups for tumor markers(alpha-fetoprotein,carcinoembryonic antigen,and carbohydrate antigen 199)or blood fat.No liver damage or other side effects were observed on chest X-ray.CONCLUSION Our study suggested that hUC-MSC transplantation has good tolerance and high safety in the treatment of T2DM.It can improve human immunity and inhibit lymphocytes.Coagulation function should be monitored vigilantly for abnormalities.

Collagen scaffold combined with human umbilical cord-mesenchymal stem cells transplantation for acute complete spinal cord injury

Currently, there is no effective strategy to promote functional recovery after a spinal cord injury. Collagen scaffolds can not only provide support and guidance for axonal regeneration, but can also serve as a bridge for nerve regeneration at the injury site. They can additionally be used as carriers to retain mesenchymal stem cells at the injury site to enhance their effectiveness. Hence, we hypothesized that transplanting human umbilical cord-mesenchymal stem cells on collagen scaffolds would enhance healing following acute complete spinal cord injury. Here, we test this hypothesis through animal studies and a phase I clinical trial.(1) Animal experiments: Models of completely transected spinal cord injury were established in rats and canines by microsurgery. Mesenchymal stem cells derived from neonatal umbilical cord tissue were adsorbed onto collagen scaffolds and surgically implanted at the injury site in rats and canines;the animals were observed after 1 week–6 months. The transplantation resulted in increased motor scores, enhanced amplitude and shortened latency of the motor evoked potential, and reduced injury area as measured by magnetic resonance imaging.(2) Phase I clinical trial: Forty patients with acute complete cervical injuries were enrolled at the Characteristic Medical Center of Chinese People's Armed Police Force and divided into two groups. The treatment group(n = 20) received collagen scaffolds loaded with mesenchymal stem cells derived from neonatal umbilical cordtissues;the control group(n = 20) did not receive the stem-cell loaded collagen implant. All patients were followed for 12 months. In the treatment group, the American Spinal Injury Association scores and activities of daily life scores were increased, bowel and urinary functions were recovered, and residual urine volume was reduced compared with the pre-treatment baseline. Furthermore, magnetic resonance imaging showed that new nerve fiber connections were formed, and diffusion tensor imaging showed that electrophysiological activity was recovered after the treatment. No serious complication was observed during follow-up. In contrast, the neurological functions of the patients in the control group were not improved over the follow-up period. The above data preliminarily demonstrate that the transplantation of human umbilical cord-mesenchymal stem cells on a collagen scaffold can promote the recovery of neurological function after acute spinal cord injury. In the future, these results need to be confirmed in a multicenter, randomized controlled clinical trial with a larger sample size. The clinical trial was approved by the Ethics Committee of the Characteristic Medical Center of Chinese People's Armed Police Force on February 3, 2016(approval No. PJHEC-2016-A8). All animal experiments were approved by the Ethics Committee of the Characteristic Medical Center of Chinese People's Armed Police Force on May 20, 2015(approval No. PJHEC-2015-D5).

Effect of glycyrrhizic acid and 18β-glycyrrhetinic acid on the differentiation of human umbilical cord-mesenchymal stem cells into hepatocytes

BACKGROUND End-stage liver disease is a global health complication with high prevalence and limited treatment options.Cell-based therapies using mesenchymal stem cells(MSCs)emerged as an alternative approach to support hepatic regeneration.In vitro preconditioning strategies have been employed to strengthen the regenerative and differentiation potential of MSCs towards hepatic lineage.Chemical compounds of the triterpene class;glycyrrhizic acid(GA)and 18β-glycyrrhetinic acid(GT)possess diverse therapeutic properties including hepatoprotection and anti-fibrosis characteristics.They are capable of modulating several signaling pathways that are crucial in hepatic regeneration.Preconditioning with hepato-protective triterpenes may stimulate MSC fate transition towards hepatocytes.AIM To explore the effect of GA and GT on hepatic differentiation of human umbilical cord-MSCs(hUC-MSCs).METHODS hUC-MSCs were isolated and characterized phenotypically by flow cytometry and immunocytochemistry for the expression of MSC-associated surface molecules.Isolated cells were treated with GA,GT,and their combination for 24 h and then analyzed at three time points;day 7,14,and 21.qRT-PCR was performed for the expression of hepatic genes.Expression of hepatic proteins was analyzed by immunocytochemistry at day 21.Periodic acid Schiff staining was performed to determine the functional ability of treated cells.RESULTS The fusiform-shaped morphology of MSCs in the treatment groups in comparison with the untreated control,eventually progressed towards the polygonal morphology of hepatocytes with the passage of time.The temporal transcriptional profile of preconditioned MSCs displayed significant expression of hepatic genes with increasing time of differentiation.Preconditioned cells showed positive expression of hepatocyte-specific proteins.The results were further corroborated by positive periodic acid Schiff staining,indicating the presence of glycogen in their cytoplasm.Moreover,bi-nucleated cells,which is the typical feature of hepatocytes,were also seen in the preconditioned cells.CONCLUSION Preconditioning with glycyrrhizic acid,18β-glycyrrhetinic acid and their combination,successfully differentiates hUC-MSCs into hepatic-like cells.These MSCs may serve as a better therapeutic option for degenerative liver diseases in future.

Effectiveness and safety of human umbilical cord-mesenchymal stem cells for treating type 2 diabetes mellitus

BACKGROUND Progressive pancreaticβ-cell dysfunction is a fundamental part of the pathology of type 2 diabetes mellitus(T2DM).Cellular therapies offer novel opportunities for the treatment of T2DM to improve the function of isletβ-cells.AIM To evaluate the effectiveness and safety of human umbilical cord-mesenchymal stem cell(hUC-MSC)infusion in T2DM treatment.METHODS Sixteen patients were enrolled and received 1×10^(6) cells/kg per week for 3 wk as intravenous hUC-MSC infusion.The effectiveness was evaluated by assessing fasting blood glucose,C-peptide,normal glycosylated hemoglobin A1c(HbA1c),insulin resistance index(homeostatic model assessment for insulin resistance),and isletβ-cell function(homeostasis model assessment ofβ-cell function).The dosage of hypoglycemic agents and safety were evaluated by monitoring the occurrence of any adverse events(AEs).RESULTS During the entire intervention period,the fasting plasma glucose level was significantly reduced[baseline:9.3400(8.3575,11.7725),day 14±3:6.5200(5.2200,8.6900);P<0.01].The HbA1c level was significantly reduced on day 84±3[baseline:7.8000(7.5250,8.6750),day 84±3:7.150(6.600,7.925);P<0.01].The patients’isletβ-cell function was significantly improved on day 28±3 of intervention[baseline:29.90(16.43,37.40),day 28±3:40.97(19.27,56.36);P<0.01].The dosage of hypoglycemic agents was reduced in all patients,of whom 6(50%)had a decrement of more than 50%and 1(6.25%)discontinued the hypoglycemic agents.Four patients had transient fever,which occurred within 24 h after the second or third infusion.One patient(2.08%)had asymptomatic nocturnal hypoglycemia after infusion on day 28±3.No liver damage or other side effects were reported.CONCLUSION The results of this study suggest that hUC-MSC infusion can improve glycemia,restore isletβ-cell function,and reduce the dosage of hypoglycemic agents without serious AEs.Thus,hUC-MSC infusion may be a novel option for the treatment of T2DM.

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.

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.

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.

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.

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.

Recovery from Bell’s palsy after treatment using uncultured umbilical cord-derived mesenchymal stem cells:A case report

BACKGROUND Bell’s palsy is an idiopathic facial palsy with an unknown cause,and 75%of patients heal spontaneously.However,the other 25%of patients continue experiencing mild or severe disabilities,resulting in a reduced quality of life.Currently,various treatment methods have been developed to treat this disease.However,there is controversy regarding their effectiveness,and new alternative treatments are needed.CASE SUMMARY The patient suffered from left-sided facial paralysis due to Bell’s palsy for 7 years.The patient received an uncultured umbilical cord-derived mesenchymal stem cell transplant eight times for treatment.After follow-up for 32 mo,the paralysis was cured,and there was no recurrence.CONCLUSION Uncultured umbilical cord-derived mesenchymal stem cell transplantation may be a potential treatment for patients with Bell’s palsy who do not spontaneously recover.

Hypoxia and inflammatory factor preconditioning enhances the immunosuppressive properties of human umbilical cord mesenchymal stem cells

BACKGROUND Mesenchymal stem cells(MSCs)have great potential for the treatment of various immune diseases due to their unique immunomodulatory properties.However,MSCs exposed to the harsh inflammatory environment of damaged tissue after intravenous transplantation cannot exert their biological effects,and therefore,their therapeutic efficacy is reduced.In this challenging context,an in vitro preconditioning method is necessary for the development of MSC-based therapies with increased immunomodulatory capacity and transplantation efficacy.AIM To determine whether hypoxia and inflammatory factor preconditioning increases the immunosuppressive properties of MSCs without affecting their biological characteristics.METHODS Umbilical cord MSCs(UC-MSCs)were pretreated with hypoxia(2%O_(2))exposure and inflammatory factors(interleukin-1β,tumor necrosis factor-α,interferon-γ)for 24 h.Flow cytometry,polymerase chain reaction,enzyme-linked immunosorbent assay and other experimental methods were used to evaluate the biological characteristics of pretreated UC-MSCs and to determine whether pretreatment affected the immunosuppressive ability of UC-MSCs in coculture with immune cells.RESULTS Pretreatment with hypoxia and inflammatory factors caused UC-MSCs to be elongated but did not affect their viability,proliferation or size.In addition,pretreatment significantly decreased the expression of coagulationrelated tissue factors but did not affect the expression of other surface markers.Similarly,mitochondrial function and integrity were retained.Although pretreatment promoted UC-MSC apoptosis and senescence,it increased the expression of genes and proteins related to immune regulation.Pretreatment increased peripheral blood mononuclear cell and natural killer(NK)cell proliferation rates and inhibited NK cell-induced toxicity to varying degrees.CONCLUSION In summary,hypoxia and inflammatory factor preconditioning led to higher immunosuppressive effects of MSCs without damaging their biological characteristics.

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.

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.

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.

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.

Cellular preconditioning and mesenchymal stem cell ferroptosis

In this editorial,we comment on the article published in the recent issue of the World Journal of Stem Cells.They focus on stem cell preconditioning to prevent ferroptosis by modulating the cystathionineγ-lyase/hydrogen sulfide(H_(2)S)pathway as a novel approach to treat vascular disorders,particularly pulmonary hypertension.Preconditioned stem cells are gaining popularity in regenerative medicine due to their unique ability to survive by resisting the harsh,unfavorable microenvironment of the injured tissue.They also secrete various paracrine factors against apoptosis,necrosis,and ferroptosis to enhance cell survival.Ferroptosis,a regulated form of cell death characterized by iron accumulation and oxidative stress,has been implicated in various pathologies encompassing dege-nerative disorders to cancer.The lipid peroxidation cascade initiates and sustains ferroptosis,generating many reactive oxygen species that attack and damage multiple cellular structures.Understanding these intertwined mechanisms provi-des significant insights into developing therapeutic modalities for ferroptosis-related diseases.This editorial primarily discusses stem cell preconditioning in modulating ferroptosis,focusing on the cystathionase gamma/H_(2)S ferroptosis pathway.Ferroptosis presents a significant challenge in mesenchymal stem cell(MSC)-based therapies;hence,the emerging role of H_(2)S/cystathionase gamma/H_(2) S signaling in abrogating ferroptosis provides a novel option for therapeutic intervention.Further research into understanding the precise mechanisms of H_(2)S-mediated cytoprotection against ferroptosis is warranted to enhance the thera-peutic potential of MSCs in clinical settings,particularly vascular disorders.

Therapeutic and regenerative potential of different sources of mesenchymal stem cells for cardiovascular diseases

Mesenchymalstemcells(MSCs)areidealcandidatesfortreatingmanycardiovasculardiseases.MSCscanmodify the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities,which are essential to restore heart function.MSCs can be easily isolated from different sources,including bone marrow,adipose tissues,umbilical cord,and dental pulp.MSCs from various sources differ in their regenerative and therapeutic abilities for cardiovascular disorders.In this review,we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function.

Living biodrugs and how tissue source influences mesenchymal stem cell therapeutics for heart failure

In this editorial we comment on the article by Safwan M et al.We especially fo-cused on the cardiac function restoration by the use of mesenchymal stem cells(MSCs)therapy for heart failure(HF),which has emerged as a new treatment approach as“Living Biodrugs”.HF remains a significant clinical challenge due to the heart’s inability to pump blood effectively,despite advancements in medical and device-based therapies.MSCs have emerged as a promising therapeutic approach,offering benefits beyond traditional treatments through their ability to modulate inflammation,reduce fibrosis,and promote endogenous tissue rege-neration.MSCs can be derived from various tissues,including bone marrow and umbilical cord.Umbilical cord-derived MSCs exhibit superior expansion ca-pabilities,making them an attractive option for HF therapy.Conversely,bone marrow-derived MSCs have been extensively studied for their potential to im-prove cardiac function but face challenges related to cell retention and delivery.Future research is focusing on optimizing MSC sources,enhancing differentiation and immune modulation,and improving delivery methods to overcome current limitations.

Tissue-source effect on mesenchymal stem cells as living biodrugs for heart failure:Systematic review and meta-analysis

BACKGROUND Mesenchymal stem cells(MSCs),as living biodrugs,have entered advanced phases of clinical assessment for cardiac function restoration in patients with myocardial infarction and heart failure.While MSCs are available from diverse tissue sources,bone-marrow-derived MSCs(BM-MSCs)remain the most wellstudied cell type,besides umbilical-cord-derived MSCs(UC-MSCs).The latter offers advantages,including noninvasive availability without ethical considerations.AIM To compare the safety and efficacy of BM-MSCs and UC-MSCs in terms of left ventricular ejection fraction(LVEF),6-min walking distance(6MWD),and major adverse cardiac events(MACEs).METHODS Five databases were systematically searched to identify randomized controlled trials(RCTs).Thirteen RCTs(693 patients)were included using predefined eligibility criteria.Weighted mean differences and odds ratio(OR)for the changes in the estimated treatment effects.RESULTS UC-MSCs significantly improved LVEF vs controls by 5.08%[95%confidence interval(CI):2.20%-7.95%]at 6 mo and 2.78%(95%CI:0.86%-4.70%)at 12 mo.However,no significant effect was observed for BM-MSCs vs controls.No significant changes were observed in the 6MWD with either of the two cell types.Also,no differences were observed for MACEs,except rehospitalization rates,which were lower only with BM-MSCs(odds ratio 0.48,95%CI:0.24-0.97)vs controls.CONCLUSION UC-MSCs significantly improved LVEF compared with BM-MSCs.Their advant-Safwan M et al.Tissue-source and MSCs as living biodrugs ageous characteristics position them as a promising alternative to MSC-based therapy.