Human Amniotic Mesenchymal Stem Cells Research Articles

Conditioned Medium from Human Amniotic Membrane-Derived Mesenchymal Stem Cells Modulates Inflammatory and Myofibrotic Factors in Vivo

Background: Heart failure (HF) is a prevalent diagnosis with a significant mortality rate. Various therapeutic approaches exist for treating HF, and human adipose-derived mesenchymal stem cells-conditioned medium (hAMSCs-CM) therapy has emerged as a promising option. Despite its potential efficacy, the precise mechanism of action underlying hAMSCs-CM treatment remains unclear. To address this knowledge gap, we conducted a novel animal study to investigate the mechanism of action of hAMSCs-CM in an HF model, with a specific focus on transforming growth factor-β (TGF-β)/galectin-3, monocyte chemoattractant protein-1 (MCP1), B-type natriuretic peptide (BNP), and aldosterone (ALD). Methods: Forty adult male Wistar rats were divided into 4 groups: control, HF, culture medium, and CM. All rats, except those in the control group, received an injection of isoproterenol to induce an animal model of HF. The CM group was administered the CM, while those in the culture medium group received standard culture media. Subsequently, serum levels of fibrotic factors, including TGF-β/galectin-3, MCP1, BNP, and ALD, were measured using ELISA. Statistical analysis was performed using one-way analysis of variance and the Tukey test. Results: Serum levels of TGF-β/galectin-3, MCP1, BNP, and ALD were significantly elevated in the HF, CM, and culture medium groups compared with the control group (P<0.001). Additionally, these fibrotic factors were significantly reduced in the CM group compared with the HF group (P<0.001). Notably, CM therapy could not restore TGF-β/galectin-3, MCP1, BNP, or ALD levels to the normal range observed in the control group. Conclusion: Our findings indicate that hAMSCs-CM modulates the expression of inflammatory and fibrotic cytokines, such as TGF-β/galectin-3, MCP1, BNP, and ALD, in isoproterenol-induced HF in male rats. These results contribute to a better understanding of the therapeutic mechanisms underlying hAMSCs-CM treatment for HF.

RGDSP-functionalized peptide hydrogel stimulates growth factor secretion via integrin αv/PI3K/AKT axis for improved wound healing by human amniotic mesenchymal stem cells.

The wound healing process involves communication among growth factors, cytokines, signaling pathways, and cells in the extracellular matrix, with growth factors acting as key regulators. Although stem cells can promote wound healing by secreting diverse growth factors, their therapeutic potential is hindered by poor survival and engraftment. Mimicking the stem cell-matrix interactions can improve stem cell survival, regulate their fate, and even enhance their paracrine effects. This study investigated the use of composite RGDmix hydrogel, which can support the survival and proliferation of human amniotic mesenchymal stem cells (hAMSCs), and effectively increase the expression of various growth factors, thereby promoting wound re-epithelialization, angiogenesis, and epidermal maturation. At last, the specific role of integrin αv and PI3K/AKT signaling pathways in the secretion of growth factors were examined by silencing them in vitro and in vivo. Results suggested that the RGDmix hydrogel improved the secretion of growth factors by hAMSCs through the RGDSP/integrin αv/PI3K/AKT axis, thereby enhancing the therapeutic effect in wound healing.

MiR-16a-5p antagonizes FGF-2 in ligamentogenic differentiation of MSC: a new therapeutic perspective for tendon regeneration

With the increasing demand for exercise, the population of patients with ankle sprain to anterior talofibular ligament injury has the characteristics of a large base and high requirements for returning to sports, and how to promote the repair of damaged ligaments from a microscopic perspective is an urgent problem to be solved. In many studies, human amniotic mesenchymal stem cells have strong differentiation ability, and can be induced to continuously differentiate into ligament cells to achieve the purpose of repairing damaged ligaments. Human amniotic stem cells were extracted and cultured from human amniotic tissues, evaluated by cell identification and other techniques, and evaluated into ligament differentiation by toluidine blue, alizarin red, oil red O staining and detection of ligament cell differentiation, protein detection by Western blot, mRNA level by qPCR, and finally, the targeted binding relationship between miR-16a-5p and mRNA FGF2 was verified by double luciferase reporter assay. The expression of collagen type 1 (COL 1), collagen type 3 (COL3), SCX and MKX was increased by overexpression of mRNA FGF2, respectively, and miR-16a-5p had a targeted effect on FGF2 and regulated the ligamentous differentiation of human amniotic mesenchymal stem cells. We found that the regulatory effect of overexpressed mRNA FGF2 on mesenchymal stem cells could be inhibited by up-regulation of miR-16a-5p, while the knockdown of FGF2 could reverse the regulatory effect of miR-16a-5p inhibition on ligament-forming differentiation of human amniotic mesenchymal stem cells. In this study, we discovered the existence of the miR-16a-5p–FGF2 axis in human amniotic mesenchymal stem cells, and the differentiation of human amniotic mesenchymal stem cells into ligamentous cells can be regulated by regulating various links in this axis.

Steroidogenic differentiation of human amniotic membrane-derived mesenchymal stem cells into a progesterone-/androgen-producing cell lineage by SF-1 and an estrogen-producing cell lineage by WT1-KTS.

Sex steroid hormones, primarily synthesized by gonadal somatic cells, are pivotal for sexual development and reproduction. Mice studies have shown that two transcription factors, steroidogenic factor 1 (SF-1) and Wilms' tumor 1 (WT1), are involved in gonadal development. However, their role in human gonadal somatic differentiation remains unclear. We therefore aimed to investigate the roles of SF-1 and WT1 in human gonadal steroidogenic cell differentiation. Using a transient lentivirus-mediated gene expression system, we assessed the effects of SF-1 and WT1 expression on the steroidogenic potential of human amniotic membrane-derived mesenchymal stem cells (hAmMSCs). SF-1 and WT1-KTS, a splice variant of WT1, played distinct roles in human steroidogenic differentiation of hAmMSCs. SF-1 induced hAmMSC differentiation into progesterone- and androgen-producing cell lineages, whereas WT1-KTS promoted hAmMSC differentiation into estrogen-producing cell lineages. Our findings revealed that SF-1 and WT1-KTS play important roles in human gonadal steroidogenic cell differentiation, especially during ovarian development. These findings may pave the way for future studies on human ovarian differentiation and development.

Influence of the Surface Topography of Titanium Dental Implants on the Behavior of Human Amniotic Stem Cells.

The dental implant surface plays a crucial role in osseointegration. The topography and physicochemical properties will affect the cellular functions. In this research, four distinct titanium surfaces have been studied: machined acting (MACH), acid etched (AE), grit blasting (GBLAST), and a combination of grit blasting and subsequent acid etching (GBLAST + AE). Human amniotic mesenchymal (hAMSCs) and epithelial stem cells (hAECs) isolated from the amniotic membrane have attractive stem-cell properties. They were cultured on titanium surfaces to analyze their impact on biological behavior. The surface roughness, microhardness, wettability, and surface energy were analyzed using interferometric microscopy, Vickers indentation, and drop-sessile techniques. The GBLAST and GBLAST + AE surfaces showed higher roughness, reduced hydrophilicity, and lower surface energy with significant differences. Increased microhardness values for GBLAST and GBLAST + AE implants were attributed to surface compression. Cell viability was higher for hAMSCs, particularly on GBLAST and GBLAST + AE surfaces. Alkaline phosphatase activity enhanced in hAMSCs cultured on GBLAST and GBLAST + AE surfaces, while hAECs showed no mineralization signals. Osteogenic gene expression was upregulated in hAMSCs on GBLAST surfaces. Moreover, α2 and β1 integrin expression enhanced in hAMSCs, suggesting a surface-integrin interaction. Consequently, hAMSCs would tend toward osteoblastic differentiation on grit-blasted surfaces conducive to osseointegration, a phenomenon not observed in hAECs.

A novel induced pluripotent stem cell model of Schwann cell differentiation reveals NF2 - related gene regulatory networks of the extracellular matrix.

Schwann cells are vital to development and maintenance of the peripheral nervous system and their dysfunction has been implicated in a range of neurological and neoplastic disorders, including NF2 -related schwannomatosis. We developed a novel human induced pluripotent stem cell (hiPSC) model to study Schwann cell differentiation in health and disease. We performed transcriptomic, immunofluorescence, and morphological analysis of hiPSC derived Schwann cell precursors (SPCs) and terminally differentiated Schwann cells (SCs) representing distinct stages of development. To validate our findings, we performed integrated, cross-species analyses across multiple external datasets at bulk and single cell resolution. Our hiPSC model of Schwann cell development shared overlapping gene expression signatures with human amniotic mesenchymal stem cell (hAMSCs) derived SCs and in vivo mouse models, but also revealed unique features that may reflect species-specific aspects of Schwann cell biology. Moreover, we identified gene co-expression modules that are dynamically regulated during hiPSC to SC differentiation associated with ear and neural development, cell fate determination, the NF2 gene, and extracellular matrix (ECM) organization. By cross-referencing results between multiple datasets, we identified new genes potentially associated with NF2 expression. Our hiPSC model further provides a tractable platform for studying Schwann cell development in the context of human disease.

Amniotic miracle: Investigating the unique development and applications of amniotic membrane in wound healing.

The perfect repair of damaged skin has always been a constant goal for scientists; however, the repair and reconstruction of skin is still a major problem and challenge in injury and burns medicine. Human amniotic membrane (hAM), with its good mechanical properties and anti-inflammatory, antioxidant and antimicrobial benefits, containing growth factors that promote wound healing, has evolved over the last few decades from simple skin sheets to high-tech dressings, such as being made into nanocomposites, hydrogels, powders, and electrostatically spun scaffolds. This paper aims to explore the historical development, applications, trends, and research hotspots of hAM in wound healing. We examined 2660 publications indexed in the Web of Science Core Collection (WoSCC) from January 1, 1975 to July 12, 2023. Utilizing bibliometric methods, we employed VOSviewer, CiteSpace, and R-bibliometrix to characterize general information, identify development trends, and highlight research hotspots. Subsequently, we identified a collection of high-quality English articles focusing on the roles of human amniotic epithelial stem cells (hAESCs), human amniotic mesenchymal stem cells (hAMSCs), and amniotic membrane (AM) scaffolds in regenerative medicine and tissue engineering. Bibliometric analysis identified Udice-French Research Universities as the most productive affiliation and Tseng S.C.G. as the most prolific author. Keyword analysis, historical direct quotations network, and thematic analysis helped us review the historical and major themes in this field. Our examination included the knowledge structure, global status, trends, and research hotspots regarding the application of hAM in wound healing. Our findings indicate that contemporary research emphasizes the preparation and application of products derived from hAM. Notably, both hAM and the cells isolated from it - hADSCs and hAESCs are prominent and promising areas of research in regenerative medicine and tissue engineering. This research delivers a comprehensive understanding of the knowledge frameworks, global dynamics, emerging patterns, and primary research foci in the realm of hAM applications for wound healing. The field is rapidly evolving, and our findings offer valuable insights for researchers. Future research outcomes are anticipated to be applied in clinical practice, enhancing methods for disease prevention, diagnosis, and treatment.

Arthrospira platensis and Gracilaria gracilis algae extracts as biological inducers for human amniotic mesenchymal stem cells (hAMSC)

Arthrospira platensis and Gracilaria gracilis algae extracts as biological inducers for human amniotic mesenchymal stem cells (hAMSC)

Human amniotic mesenchymal stem cell-islet organoids enhance the efficiency of islet engraftment in a mouse diabetes model

AimsDespite islet transplantation has proved a great potential to become the standard therapy for type 1 diabetes mellitus (T1DM), this approach remains limited by ischemia, hypoxia, and poor revascularization in early post-transplant period as well as inflammation and life-long host immune rejection. Here, we investigate the potential and mechanism of human amniotic mesenchymal stem cells (hAMSCs)-islet organoid to improve the efficiency of islet engraftment in immunocompetent T1DM mice. Main methodsWe generated the hAMSC-islet organoid structure through culturing the mixture of hAMSCs and islets on 3-dimensional-agarose microwells. Flow cytometry, whole-body fluorescent imaging, immunofluorescence, Calcein-AM/PI staining, ELISA, and qPCR were used to assess the potential and mechanism of shielding hAMSCs to improve the efficiency of islet transplantation. Key findingsTransplant of hAMSC-islet organoids results in remarkably better glycemic control, an enhanced glucose tolerance, and a higher β cell mass in vivo compared with control islets. Our results show that hAMSCs shielding provides an immune privileged microenvironment for islets and promotes graft revascularization in vivo. In addition, hAMSC-islet organoids show higher viability and reduced dysfunction after exposure to hypoxia and inflammatory cytokines in vitro. Finally, our results show that shielding with hAMSCs leads to the activation of PKA-CREB-IRS2-PI3K and PKA-PDX1 signaling pathways, up-regulation of SIL1 mRNA levels, and down-regulation of MT1 mRNA levels in β cells, which ultimately promotes the synthesis, folding and secretion of insulin, respectively. SignificancehAMSC-islet organoids can evidently increase the efficiency of islet engraftment and might develop into a promising alternative for the clinical treatment of T1DM.

Beneficial effects of bioactive peptides extracted from Spirulina platensis and Gracilaria gracilis algae on bone regeneration/osteogenic differentiation of mesenchymal stem cells

Mesenchymal stem cells are used in the treatment of many diseases, particularly in the repair of bone injuries. Algae with various medicinal applications are considered important natural resources. There is limited research on the effects of bioactive peptides from algae extraction on mesenchymal stem cells. In this study the impact of bioactive proteins, protein lysates and peptide fractions (<3, <30 and <50 kDa) isolated from two algae species, Spirulina platensis and Gracilaria gracilis on the proliferation and osteogenic differentiation of human amniotic mesenchymal stem cells (hAMSCs) was investigated. The proteins were extracted ant hydrolyzed with trypsin enzyme to create peptides, which were then separated by ultrafiltration. hAMSCs were exposed to different concentrations of bioactive compounds (100, 300, 500 and 700 µg/ml) for varying time periods. Cell proliferation was assessed using the with 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and to evaluate differentiation into bone tissue, the amount of mineral deposition was measured with alizarin red staining, and alkaline phosphatase enzyme activity was determined using a colorimetric method. The expression of Runx2, Osteocalcin, and β-Catenin genes expression was analyzed using RT-qPCR on days 7, 14 and 21 post-treatment. The results indicated that the <3 kDa peptide fraction of S. platensis and G. gracilis had no cytotoxic effects, increased cell proliferation at a concentration of 300 μg/ml, and enhanced the expression of osteogenic marker genes, alkaline phosphatase enzyme a activity, and calcium deposition in the extracellular matrix. In general, fractions that show positive effects on hAMSC differentiation have the potential to treat bone defects and promote osteoregeneration.

Investigating the indirect therapeutic effect of hAMSCs utilizing a novel scaffold (PGS-co-PCL/PGC/PPy/Gelatin) in myocardial ischemia-reperfusion-induced renal failure in male Wistar rats

BackgroundMyocardial ischemia-reperfusion (MI/R) occurs due to temporary or permanent interruptions in the coronary and circulatory system, indirectly affecting kidney function through reduced cardiac output for metabolic needs. In this study, the aim was to explore the indirect effects of using human amniotic membrane mesenchymal stem cells (hAMSCs) with the PGS-co-PCL/PGC/PPy/Gelatin scaffold in male rats with renal failure induced by miocardial ischemia-reperfusion. MethodsMI/R injury was induced in 48 male Wistar rats through left anterior descending artery ligation, divided into four groups (n=12); control group, cell group, scaffold group, and celss+scaffold group. Evaluations were conducted at two and thirty days post MI/R injury, encompassing echocardiography, biochemical, inflammatory markers analysis, and histological assessment. ResultsEchocardiographic findings exhibited notable enhancement in ejection fraction, fractional shortening, and stroke volume of treated groups compared to controls after 30 days (P< 0.05). Serum creatinine (P< 0.001) and urea (P< 0.05) levels significantly decreased in the scaffold+cells group) compared to the control group. The treated cells+ scaffold group displayed improved kidney structure, evidenced by larger glomeruli and reduced Bowman's space compared to the control group (P< 0.01). Immunohistochemical analysis indicated reduced TNF-α protein in the scaffold+ cells group (P< 0.05) in contrast to the control group (P< 0.05). Inflammatory factors IL-6, TNF-α, and AKT gene expression in renal tissues were improved in scaffold+ cells-treated animals. ConclusionOur research proposes the combination of hAMSCs and the PGS-co-PCL/PGC/PPy/Gelatin scaffold in MI/R injured rats appears to enhance renal function and reduce kidney inflammation by improving cardiac output.

The improvement of inflammatory infiltration and pregnancy outcome in mice with recurrent spontaneous abortion by human amniotic mesenchymal stem cells.

Recurrent spontaneous abortion is thought to be mostly triggered by immune-related causes. Mesenchymal stem cells, which exhibit the traits of multi-directional differentiation capacity and low immunogenicity, have recently been recommended as a viable treatment for spontaneous abortion-prone mice to increase the success of pregnancy. Amniotic membrane tissue is a byproduct of pregnancy and delivery that has a wide range of potential uses due to its easy access to raw materials and little ethical constraints. To construct an abortion-prone mouse model for this investigation, CBA/J female mice were coupled with male DBA/2 mice, while CBA/J female mice were paired with male BALB/c mice as a control. The identical volume of human amniotic mesenchymal stem cells or phosphate buffer was injected intraperitoneally on the 4.5th day of pregnancy. CBA/J female mice were sacrificed by cervical dislocation on the 13.5th day of pregnancy, the embryo absorption rate was calculated, and the uterus, decidua tissues and placenta were gathered for examination. Through detection, it was discovered that human amniotic mesenchymal stem cells significantly increased the expression of interleukin 10 and transforming growth factor beta, while they significantly decreased the expression of interleukin 1 beta and interleukin 6, improved vascular formation and angiogenesis, and minimized the embryo absorption rate and inflammatory cell infiltration in the recurrent spontaneous abortion + human amniotic mesenchymal stem cells group. In any case, human amniotic mesenchymal stem cells regulate inflammatory factors and cell balance at the maternal-fetal interface, which result in a reduction in the rate of embryo absorption and inflammatory infiltration and provide an innovative perspective to the clinical therapy of recurrent spontaneous abortion.

Human amniotic mesenchymal stem cells-derived conditioned medium and exosomes alleviate oxidative stress-induced retinal degeneration by activating PI3K/Akt/FoxO3 pathway

Age-related macular degeneration (AMD) is the leading cause of vision loss among the elderly, which is primarily attributed to oxidative stress-induced damage to the retinal pigment epithelium (RPE). Human amniotic mesenchymal stem cells (hAMSC) were considered to be one of the most promising stem cells for clinical application due to their low immunogenicity, tissue repair ability, pluripotent potential and potent paracrine effects. The conditional medium (hAMSC-CM) and exosomes (hAMSC-exo) derived from hAMSC, as mediators of intercellular communication, play an important role in the treatment of retinal diseases, but their effect and mechanism on oxidative stress-induced retinal degeneration are not explored. Here, we reported that hAMSC-CM alleviated H2O2-induced ARPE-19 cell death through inhibiting mitochondrial-mediated apoptosis pathway in vitro. The overproduction of reactive oxygen species (ROS), alteration in mitochondrial morphology, loss of mitochondrial membrane potential and elevation of Bax/Bcl2 ratio in ARPE-19 cells under oxidative stress were efficiently reversed by hAMSC-CM. Moreover, it was found that hAMSC-CM protected cells against oxidative injury via PI3K/Akt/FoxO3 signaling. Intriguingly, exosome inhibitor GW4869 alleviated the inhibitory effect of hAMSC-CM on H2O2-induced decrease in cell viability of ARPE-19 cells. We further demonstrated that hAMSC-exo exerted the similar protective effect on ARPE-19 cells against oxidative damage as hAMSC-CM. Additionally, both hAMSC-CM and hAMSC-exo ameliorated sodium iodate-induced deterioration of RPE and retinal damage in vivo. These results first indicate that hAMSC-CM and hAMSC-exo protect RPE cells from oxidative damage by regulating PI3K/Akt/FoxO3 pathway, suggesting hAMSC-CM and hAMSC-exo will be a promising cell-free therapy for the treatment of AMD in the future.

IGF-1 Genome-Edited Human MSCs Exhibit Robust Anti-Arthritogenicity in Collagen-Induced Arthritis.

Stem cell therapy stands out as a promising avenue for addressing arthritis treatment. However, its therapeutic efficacy requires further enhancement. In this study, we investigated the anti-arthritogenic potential of human amniotic mesenchymal stem cells (AMM) overexpressing insulin-like growth factor 1 (IGF-1) in a collagen-induced mouse model. The IGF-1 gene was introduced into the genome of AMM through transcription activator-like effector nucleases (TALENs). We assessed the in vitro immunomodulatory properties and in vivo anti-arthritogenic effects of IGF-1-overexpressing AMM (AMM/I). Co-culture of AMM/I with interleukin (IL)-1β-treated synovial fibroblasts significantly suppressed NF-kB levels. Transplantation of AMM/I into mice with collagen-induced arthritis (CIA) led to significant attenuation of CIA progression. Furthermore, AMM/I administration resulted in the expansion of regulatory T-cell populations and suppression of T-helper-17 cell activation in CIA mice. In addition, AMM/I transplantation led to an increase in proteoglycan expression within cartilage and reduced infiltration by inflammatory cells and also levels of pro-inflammatory factors including cyclooxygenase-2 (COX-2), IL-1β, NF-kB, and tumor necrosis factor (TNF)-α. In conclusion, our findings suggest that IGF-1 gene-edited human AMM represent a novel alternative therapeutic strategy for the treatment of arthritis.

Effects of Mesenchymal Stem Cells-Derived Extracellular Vesicles on Inhibition of Hepatic Fibrosis by Delivering miR-200a.

Hepatic fibrosis (HF) is a common pathological feature of chronic hepatic diseases. We aimed to illuminate the significance of amniotic mesenchymal stem cells (AMSCs)-derived extracellular vesicles (AMSCs-EVs) in HF. Human AMSCs-EVs were isolated and identified. HF mice were constructed and treated with EVs. The fibrosis was observed by staining experiments and Western blot (WB) assay. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and hepatic hydroxyproline (Hyp) were detected to confirm liver function. For the in vitro experiments, human hepatic stellate cells were induced with transforming growth factor-β and treated with EVs. To measure the degree of HF, the expression of alpha-smooth muscle actin (α-SMA) and Collagen I was detected by WB assay, and cell proliferation was detected by cell counting kit 8 assay. The levels of miR-200a, Zinc finger E-box binding homeobox 1 (ZEB1), and phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3) were detected by WB and real-time quantitative polymerase chain reaction. The binding of ZEB1 to PIK3R3 and miR-200a to ZEB1 was analyzed by chromatin immunoprecipitation and dual luciferase assays to validate their relationships. Human AMSCs and AMSCs-EVs were obtained. Serum ALT, AST, TBIL, and hepatic Hyp were increased, implying the fibrosis degree was aggravated in HF mice, which was decreased again after EV treatment. EVs inhibited HF degree by reducing α-SMA and Collagen I and promoting cell proliferation. AMSCs-EVs delivered miR-200a into hepatocytes, which up-regulated miR-200a expression, inhibited ZEB1 expression, and reduced its enrichment on the PIK3R3 promoter, therefore inhibiting PIK3R3 expression and alleviating HF. Overexpression of ZEB1 or PIK3R3 attenuated the anti-fibrotic effect of AMSCs-EVs. Human AMSCs-derived EVs mediated miR-200a delivery and inhibition of intracellular ZEB1/PIK3R3 axis to exert anti-fibrosis effects.

Human amniotic mesenchymal stem cells inhibit immune rejection injury from allogeneic mouse heart transplantation: A preliminary study on the microRNA expression

BackgroundMesenchymal stem cell therapy is a new treatment for immune rejection in heart transplantation. The aim of this paper is to investigate the effect of human amniotic mesenchymal stem cells (hAMSCs) on alleviating immune rejection of allogeneic heart transplantation in mice and its possible underlying mechanism. MethodsWe injected hAMSCs into cervical ectopic heart transplantation model mice via tail vein to observe the survival time, the pathological changes of donor myocardium, and the fluorescent distribution of hAMSCs after the transplantation. MicroRNAs (miRs) with significantly differential expression were obtained by RNA sequencing and bioinformatic analysis, and a dual luciferase reporter gene assay together with real-time quantitative PCR (qRT-PCR) was performed to verify the relationship between miRs and their targeting genes. ResultsThe intervention of hAMSCs prolonged the graft survival time and alleviated the pathological damage of the donor heart. The injected hAMSCs were distributed mainly in the liver, spleen, and kidney, only a very small portion in the donor and recipient hearts. In the allogeneic transplantation models, the expression of miR-34b-5p significantly increased after hAMSC treatment. MiR-34b-5p showed a knockdown effect on gene Fc gamma receptor 2B (FCGR2B). ConclusionshAMSCs can reduce the immune rejection injury after allogeneic heart transplantation. This effect may be associated with the upregulation of miR-34b-5p expression to knock down its targeting gene FCGR2B.

Hypoxia preconditioning of human amniotic mesenchymal stem cells enhances proliferation and migration and promotes their homing via the HGF/C-MET signaling axis to augment the repair of acute liver failure

BackgroundTransplantation of mesenchymal stem cells (MSCs) is a newly developed strategy for treating acute liver failure (ALF). Nonetheless, the low survival rate of MSCs after transplantation and their poor homing to damaged tissues limit the clinical application of MSCs. The research assessed whether hypoxic preconditioning (HPC) can improve the biological activity of human amniotic mesenchymal stem cells (hA-MSCs), promote their homing ability to the liver of mice with ALF, and influence liver tissue repair. MethodsFlow cytometry, CCK8, Transwell, and Western blotting assays were conducted to assess the effects of hypoxic preconditioning on the phenotype, proliferation, and migration of hA-MSCs and the changes in the c-Met and CXCR4 gene expression levels were studied. To evaluate the effects of the transplantation of hypoxic preconditioning of hA-MSCs on the homing and repair of D-galactosamine (D-GalN)/LPS-induced ALF, the mechanism was elucidated by adding c-Met, CXCR4-specific blockers (SU11274 and AMD3100). ResultsAfter hypoxia pretreatment (1% oxygen volume fraction), hA-MSCs maintained the morphological characteristics of adherence and vortex colony growth and showed high CD44, CD90, and CD105 and low CD31, CD34, and CD45 expression levels. Hypoxic preconditioning of hA-MSCs significantly increased their proliferation and migration and highly expressed the c-Met and CXCR4 genes. In vivo and in vitro, this migration-promoting effect was suppressed by the c-Met specific blocker SU11274. In the acute liver failure mouse model, the HGF expression level was considerably elevated in the liver than that in the serum, lungs and kidneys. The transplantation of hypoxic preconditioned hA-MSCs introduced a remarkable improvement in the liver function and survival rate of mice with ALF and enhanced the anti-apoptosis ability of liver cells. The anti-apoptotic enhancing effect of hypoxic preconditioning was suppressed by the c-Met specific blocker SU11274. Hypoxic hA-MSCs administration was observed to have considerably increased the fluorescent cells in the liver than that recorded after administering normal oxygen-hA-MSCs. The number of hepatic fluorescent cells decreased remarkably after adding the c-Met inhibitor SU11274, compared to that recorded after hypoxic pretreatment, whereas the effect of c-Met inhibitor SU11274 on normal oxygen-hA-MSCs was not significant. ConclusionsHypoxic preconditioning depicted no impact on the morphology and phenotype features of the human amniotic mesenchymal stem cells, but it can promote their proliferation, migration, anti-apoptotic effect, and homing rate and improve the repair of acute liver failure, which might be mediated by the HGF/c-Met signaling axis.

Dual cross-linked COL1/HAp bionic gradient scaffolds containing human amniotic mesenchymal stem cells promote rotator cuff tendon–bone interface healing

The tendon-bone interface heals through scar tissue, while the lack of a natural interface gradient structure and collagen fibre alignment leads to the occurrence of retearing. Therefore, the promotion of tendon healing has become the focus of regenerative medicine. The purpose of this study was to develop a gradient COL1/ hydroxyapatite (HAp) biomaterial loaded with human amniotic mesenchymal stem cells (hAMSCs). The performance of common cross-linking agents, Genipin, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS), and dual cross-linked materials were compared to select the best cross-linking mechanism to optimize the biological and mechanical properties of the scaffold. The optimal COL1/HAp-loaded with hAMSCs were implanted into the tendon-bone rotator cuff interfaces in rats and the effect on the tendon-bone healing was assessed by micro-CT, histological analysis, and biomechanical properties. The results showed that Genipin and EDC/NHS dual cross-linked COL1/HAp had good biological activity and mechanical properties and promoted the proliferation and differentiation of hAMSCs. Animal experiments showed that the group using a scaffold loaded with hAMSCs had excellent continuity and orientation of collagen fibers, increased fibrocartilage and bone formation, and significantly higher biomechanical functions than the control group at the interface at 12 weeks post operation. This study demonstrated that dual cross-linked gradient COL1/HAp-loaded hAMSCs could promote interface healing, thereby providing a feasible strategy for tendon-bone interface regeneration.

Intravenous administration exosomes derived from human amniotic mesenchymal stem cells improves neurological recovery after acute traumatic spinal cord injury in rats.

Our previous study has showed that human amniotic mesenchymal stem cells (hAMSCs) transplantation improves neurological recovery after traumatic spinal cord injury (TSCI) in rats. However, less is known about the effects of exosomes derived from hAMSCs for TSCI. Here, we investigated whether hAMSCs-derived exosomes improve neurological recovery in TSCI rats and the underlying mechanisms. A rat traumatic spinal cord injury (TSCI) mode was established using a weight drop device. At 2 hr after TSCI, rats were administered either hAMSCs-derived exosomes or phosphate buffered saline via the tail vein. Locomotor recovery was evaluated by an open-field locomotor rating scale and gridwalk task. Spinal cord water content, hematoxylin and eosin (H&E) staining, Evans blue (EB) dye extravasation, immunofluorescence staining, and enzyme-linked immunosorbent were performed to elucidate the underlying mechanism. hAMSCs-derived exosomes significantly reduced the numbers of ED1+ macrophages/microglia and caspase-3+cells and decreased the levels of reactive oxygen species, myeloperoxidase activity and inflammatory cytokines, such as tumor necrosis factor alpha, interleukin-6 and interleukin-1β. In addition, hAMSCs-derived exosomes significantly attenuated spinal cord water content and Evans blue extravasation, and enhanced angiogenesis and axonal regeneration. Finally, hAMSCs-derived exosomes also significantly reduced the lesion volume, inhibited astrogliosis, and improved functional recovery. Taken together, these findings demonstrate that hAMSCs-derived exosomes have favourable effects on rats after acute TSCI, and that they may serve as an alternative cell-free therapeutic approach for treating acute TSCI.

Differentiation potential of human amniotic fluid-derived mesenchymal stem cells into hepatocyte-like cells

Differentiation potential of human amniotic fluid-derived mesenchymal stem cells into hepatocyte-like cells