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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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-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.

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

BACKGROUND

Transplantation 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.

METHODS

Flow 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).

RESULTS

After 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.

CONCLUSIONS

Hypoxic 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.

Human amniotic MSCs-mediated anti-inflammation of CD206hiIL-10hi macrophages alleviates isoproterenol-induced ventricular remodeling in mice

BACKGROUND

Human amniotic mesenchymal stem cells (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammation which makes them suitable for the treatment of various diseases.

OBJECTIVE

This study aimed to explore the therapeutic effect and molecular mechanism of hAMSCs in ventricular remodeling (VR).

METHODS

hAMSCs were characterized by a series of experiments such as flow cytometric analysis, immunofluorescence, differentiative induction and tumorigenicity. Mouse VR model was induced by isoproterenol (ISO) peritoneally, and the therapeutic effects and the potential mechanisms of hAMSCs transplantation were evaluated by echocardiography, carboxy fluorescein diacetate succinimidyl ester (CFSE) labeled cell tracing, histochemistry, qRT-PCR and western blot analysis. The co-culturing experiments were carried out for further exploring the mechanisms of hAMSCs-derived conditioned medium (CM) on macrophage polarization and fibroblast fibrosis in vitro.

RESULTS

hAMSCs transplantation significantly alleviated ISO-induced VR including cardiac hypertrophy and fibrosis with the improvements of cardiac functions. CFSE labeled hAMSCs kept an undifferentiated state in heart, indicating that hAMSCs-mediated the improvement of ISO-induced VR might be related to their paracrine effects. hAMSCs markedly inhibited ISO-induced inflammation and fibrosis, seen as the increase of M2 macrophage infiltration and the expressions of CD206 and IL-10, and the decreases of CD86, iNOS, COL3 and αSMA expressions in heart, suggesting that hAMSCs transplantation promoted the polarization of M2 macrophages and inhibited the polarization of M1 macrophages. Mechanically, hAMSCs-derived CM significantly increased the expressions of CD206, IL-10, Arg-1 and reduced the expressions of iNOS and IL-6 in RAW264.7 macrophages in vitro. Interestingly, RAW264.7-CM remarkably promoted the expressions of anti-inflammatory factors such as IL-10, IDO, and COX2 in hAMSCs. Furthermore, the CM derived from hAMSCs pretreated with RAW264.7-CM markedly inhibited the expressions of fibrogenesis genes such as αSMA and COL3 in 3T3 cells.

CONCLUSION

Our results demonstrated that hAMSCs effectively alleviated ISO-induced cardiac hypertrophy and fibrosis, and improved the cardiac functions in mice, and the underlying mechanisms might be related to inhibiting the inflammation and fibrosis during the ventricular remodeling through promoting the polarization of CD206hiIL-10hi macrophages in heart tissues. Our study strongly suggested that by taking the advantages of the potent immunosuppressive and anti-inflammatory effects, hAMSCs may provide an alternative therapeutic approach for prevention and treatment of VR clinically.

Immune and cytokine alterations and RNA-sequencing analysis in gestational tissues from pregnant women after recovery from COVID-19

BACKGROUND

COVID-19 is a global pandemic. Understanding the immune responses in pregnant women recovering from COVID-19 may suggest new therapeutic approaches.

METHODS

We performed a cross-sectional study between March 1, 2020, and September 1, 2020. Participants were assigned into the convalescent COVID-19 group if they had a previous COVID-19 infection during pregnancy or the healthy control group. RNA-Seq was performed on human umbilical cord mesenchymal stem cells (hUMSCs) and human amniotic mesenchymal stem cells (hAMSCs). Immunohistochemical staining, cytokine testing, lymphocyte subset analysis, RNA-Seq, and functional analyses were performed on the placental and umbilical cord blood (UCB) and compared between the two groups.

RESULTS

A total of 40 pregnant women were enrolled, with 13 in the convalescent group and 27 in the control group. There were 1024, 46, and 32 differentially expressed genes (DEGs) identified in the placental tissue, hUMSCs, and hAMSCs between the convalescent and control groups, respectively. Enrichment analysis showed those DEGs were associated with immune homeostasis, antiviral activity, cell proliferation, and tissue repair. Levels of IL-6, TNF-α, total lymphocyte counts, B lymphocytes, Tregs percentages, and IFN-γ expressing CD4+ and CD8+ T cells were statistically different between two groups (p ≤ 0.05). ACE2 and TMPRSS2 expressed on the placenta were not different between the two groups (p > 0.05).

CONCLUSION

Multiple changes in immune responses occurred in the placental tissue, hUMSCs, and hAMSCs after maternal recovery from COVID-19, which might imply their protective roles against COVID-19 infection.

Human amniotic mesenchymal stem cell-conditioned medium inhibited LPS-induced cell injury and inflammation by modulating CD14/TLR4-mediated signaling pathway in monocytes

Human amniotic mesenchymal stem cells (hAMSCs) have attracted considerable attention as a promising regenerative therapy. Many studies reported that the conditioned medium of hAMSCs (AM-CM) exerted anti-inflammatory and immunomodulatory functions, while its underlying mechanism is poorly understood. In this study, we first confirmed that AM-CM (25%, 50%, 100%) was optimal for anti-inflammation at 24 h. Lipopolysaccharide (LPS)-induced alteration of cell morphology, the decrease of cell proliferation, and the upregulation of cell apoptosis were significantly reversed in AM-CM-treated THP-1 cells. 25% and 50% AM-CM significantly decreased LPS-induced intracellular reactive oxygen species (ROS) production and proinflammatory cytokines secretion. Mechanistically, we found that AM-CM treatment suppressed LPS-induced activation of MAPK and NF-κB pathways by inhibiting CD14/TLR4 in THP-1 cells. Meanwhile, activation of NLRP3 inflammasome was also dose-dependently attenuated by AM-CM treatment. Thus, AM-CM may exert positive influences on the inflammation microenvironment and provide a novel strategy for improving tissue regeneration.

CD44 mediates hyaluronan to promote the differentiation of human amniotic mesenchymal stem cells into chondrocytes

OBJECTIVES

CD44 is the major receptor for hyaluronan (HA), but its effect on HA-induced differentiation of human amnion mesenchymal stem cells into chondrocytes is unclear. This study aimed to investigate the effects and mechanisms of CD44 in HA-induced chondrogenesis.

METHODS

Immunocytochemistry and toluidine blue staining were used to assess the secretion of type II collagen and aggrecan, respectively. qRT-PCR and western blotting were performed to evaluate the expression of key genes and proteins.

RESULTS

The expression of aggrecan and type II collagen was downregulated after using the anti-CD44 antibody (A3D8). The transcriptional levels of chondrocytes‑associated genes SRY‑box transcription factor 9, aggrecan, and collagen type II alpha 1 chain were also decreased. Thus, CD44 may mediate HA-induced differentiation of hAMSCs into chondrocytes. Further investigation indicated that expression of phosphorylated (p)‑Erk1/2 and p‑Smad2 decreased following CD44 inhibition. The changes in the expression of p-Erk1/2 and p-Smad2 were consistent after using the ERK1/2 inhibitor (U0126) and agonist (EGF), respectively. After administering the p-Smad2 inhibitor, the expression levels of p-ERK1/2 and p-Smad2 appeared downregulated. The results showed crosstalk between Erk1/2 and Smad2. Moreover, inhibition of p-Erk1/2 and p-Smad2 significantly reduced the accumulation of aggrecan and type II collagen.

CONCLUSION

These data indicate that CD44 mediates HA-induced differentiation of hAMSCs into chondrocytes by regulating Erk1/2 and Smad2 signaling.

Human amniotic mesenchymal stem cells-derived IGFBP-3, DKK-3, and DKK-1 attenuate liver fibrosis through inhibiting hepatic stellate cell activation by blocking Wnt/β-catenin signaling pathway in mice

Background

Liver fibrosis is an outcome of restoring process in chronic liver injury. Human amniotic mesenchymal stem cells (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating liver fibrosis. This study aimed to explore the effect and mechanism of hAMSCs on liver fibrosis.

Methods

hAMSCs were transplanted into carbon tetrachloride (CCl₄)-induced liver fibrosis mice via tail vein, and the effects of hAMSCs on hepatic fibrosis were assessed. The effects of hAMSCs and hAMSCs conditional medium (CM) on the activation of hepatic stellate cells (HSCs) were investigated in vivo and in vitro. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may inhibit the activation of HSCs. Finally, the underlying mechanisms were explored by assessing IGF-1R/PI3K/AKT and GSK3β/β-catenin signaling pathways in the activated HSCs (LX-2) with hAMSCs and hAMSCs transfected with corresponding siRNAs.

Results

Our results showed that hAMSCs possessed the characterizations of mesenchymal stem cells. hAMSCs significantly reduced liver fibrosis and improved liver function in mice by inhibiting HSCs activation in vivo. Both hAMSCs and hAMSC-CM remarkably inhibited the collagen deposition and activation of LX-2 cells in vitro. Antibody array assay showed that insulin-like growth factor binding protein-3 (IGFBP-3), Dickkopf-3 (DKK-3), and Dickkopf-1 (DKK-1) were highly expressed in the co-culture group and hAMSC-CM group compared with LX-2 group. Western blot assay demonstrated that IGFBP-3, DKK-3, and DKK-1 derived from hAMSCs inhibit LX-2 cell activation through blocking canonical Wnt signaling pathway.

Conclusions

Our results demonstrated that IGFBP-3, Dkk3, and DKK-1 secreted by hAMSCs attenuated liver fibrosis in mice through inhibiting HSCs activation via depression of Wnt/β-catenin signaling pathway, suggesting that hAMSCs or hAMSC-CM provides an alternative therapeutic approach for the treatment of liver fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02906-z.

Human amniotic mesenchymal stem cells combined with PPCNg facilitate injured endometrial regeneration

BACKGROUND

Caused by the injury to the endometrial basal layer, intrauterine adhesions (IUA) are characterized by uterine cavity obliteration, leading to impaired fertility. Human amniotic mesenchymal stem cells (hAMSCs) have the potential to promote endometrial regeneration mainly through paracrine ability. PPCNg is a thermoresponsive biomaterial consisted of Poly (polyethylene glycol citrate-co-N-isopropylacrylamide) (PPCN) mixed with gelatin, which has been reported as a scaffold for stem cell transplantation. This study aims to investigate the therapeutic effect of hAMSCs combined with PPCNg transplantation in promoting the regeneration of injured endometrium.

METHODS

hAMSCs were cultured in different concentrates of PPCNg in vitro, and their proliferation, apoptosis and cell cycle were examined by CCK-8 assay and flow cytometry. Immunofluorescence was used to determine the MSCs specific surface markers. The expression of pluripotent genes was analyzed by qRT-PCR. The multiple-lineage differentiation potential was further evaluated by detecting the differentiation-related genes using qRT-PCR and specific staining. The Sprague-Dawley (SD) rat IUA model was established with 95% ethanol. hAMSCs combined with PPCNg were transplanted through intrauterine injection. The retention of DiR-labeled hAMSCs was observed by vivo fluorescence imaging. The endometrium morphology was assessed using hematoxylin and eosin (H&E) and Masson staining. Immunohistochemistry staining was performed to detect biomarkers related to endometrial proliferation, re-epithelialization, angiogenesis and endometrial receptivity. The function of regenerated endometrium was evaluated by pregnancy tests.

RESULTS

hAMSCs maintained normal cell proliferation, apoptosis and cell cycle in PPCNg. Immunofluorescence and qRT-PCR showed that hAMSCs cultured in PPCNg and hAMSCs cultured alone expressed the same surface markers and pluripotent genes. hAMSCs exhibited normal multilineage differentiation potential in PPCNg. Vivo fluorescence imaging results revealed that the fluorescence intensity of hAMSCs combined with PPCNg intrauterine transplantation was stronger than that of direct hAMSCs intrauterine transplantation. Histological assays showed the increase in the thickness of endometrial and the number of endometrial glands, and the remarkably decrease in the fibrosis area in the PPCNg/hAMSCs group. The expressions of Ki-67, CK7, CK19, VEGF, ER and PR were significantly increased in the PPCNg/hAMSCs group. Moreover, the number of implanted embryos and pregnancy rate were significantly higher in the PPCNg/hAMSCs group than in the hAMSCs group.

CONCLUSIONS

PPCNg is suitable for growth, phenotype maintenance and multilineage differentiation of hAMSCs. hAMSCs combined with PPCNg intrauterine transplantation can facilitate the regeneration of injured endometrium by improving utilization rates of hAMSCs, and eventually restore reproductive capacity.

Icariside II promotes the differentiation of human amniotic mesenchymal stem cells into dopaminergic neuron-like cells

The purpose of this study is to observe the effect of icariside II (ICS II) on the differentiation of human amniotic mesenchymal stem cells (hAMSCs) into dopaminergic neuron-like cells, the involvement of PI3K signaling pathway inhibitors. After identifying hAMSCs by flow cytometry, hAMSCs were induced and treated with ICS II at 10 μmol/L, 3 μmol/L, 1 μmol/L, and 0 μmol/L. hAMSCs in the LY294002+3μM ICS II group were pretreated with 20 μmol/L LY294002, a PI3K-specific inhibitor, for 1 h, and then hAMSCs were induced with 3 μmol/L ICS II. On the 21st day of induction, immunofluorescence was used to detect expression of the neuronal nuclei (NeuN), neuron-specific enolase (NSE), microtubule-associated protein-2 (MAP-2), glial fibrillary acidic protein (GFAP), and tyrosine hydroxylase (TH) antigens in each induced cell group. Western blotting was used to detect the relative protein expression of NSE, MAP-2, GFAP, and TH. ELISA was used to detect the dopamine concentration in the induction medium supernatant of each group. After 21 d of ICS II induction, immunofluorescence showed that GFAP expression was not obvious in any hAMSC group. The NeuN, NSE, MAP-2, and TH fluorescent proteins were expressed in each group. NeuN was expressed in the nucleus and cytoplasm, while NSE, MAP-2, and TH were mainly expressed in the cytoplasm. The positive cell rates of NeuN, NSE, MAP-2, and TH in the 10 μmol/L, 3 μmol/L, and 1 μmol/L ICS II groups were higher than those in the LY294002+3μM ICS II and control groups. After 21 d of induction, the Western blot results showed that the protein expression levels of NSE, MAP-2, and TH in the 10 μmol/L, 3 μmol/L, and 1 μmol/L ICS II groups were significantly higher than those in the LY294002+3μM ICS II and control groups. The MAP-2 protein expression levels in the 10 μmol/L and 3 μmol/L groups were higher than that in the 1 μmol/L group. After 21 d of induction, the dopamine concentrations in the culture supernatants of the 10 μmol/L, 3 μmol/L, and 1 μmol/L ICS II groups were higher than those in the LY294002+3μM ICS II and control groups. In our experiment, ICS II induced hAMSCs to differentiate into dopaminergic neuron-like cells, and the optimal concentration range of ICS II was 3-10 μmol/L. Moreover, the PI3K signaling pathway is involved in the above differentiation process.

miR-146a-3p suppressed the differentiation of hAMSCs into Schwann cells via inhibiting the expression of ERBB2

Human amniotic mesenchymal stem cells (hAMSCs) can be differentiated into Schwann-cell-like cells (SCLCs) in vitro. However, the underlying mechanism of cell differentiation remains unclear. In this study, we explored the phenotype and multipotency of hAMSCs, which were differentiated into SCLCs, and the expression of nerve repair-related Schwann markers, such as S100 calcium binding protein B (S-100), TNF receptor superfamily member 1B (P75), and glial fibrillary acidic protein (GFAP) were observed to be significantly increased. The secreted functional neurotrophic factors, like brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin-3 (NT-3), were determined and also increased with the differentiation time. Moreover, miR-146a-3p, which significantly decreased during the differentiation of hAMSCs into SCLCs, was selected by miRNA-sequence analysis. Further molecular mechanism studies showed that Erb-B2 receptor tyrosine kinase 2 (ERBB2) was an effective target of miR-146a-3p and that miR-146a-3p down-regulated ERBB2 expression by binding to the 3'-UTR of ERBB2. The expression of miR-146a-3p markedly decreased, while the mRNA levels of ERBB2 increased with the differentiation time. The results showed that down-regulating miR-146a-3p could promote SC lineage differentiation and suggested that miR-146a-3p negatively regulated the Schwann-like phenotype differentiation of hAMSCs by targeting ERBB2. The results will be helpful to establish a deeper understanding of the underlying mechanisms and find novel strategies for cell therapy.

FoxO1 and Wnt/β-catenin signaling pathway: Molecular targets of human amniotic mesenchymal stem cells-derived conditioned medium (hAMSC-CM) in protection against cerebral ischemia/reperfusion injury

Ischemia-reperfusion (I/R) injury has weakened the effects of available treatment options for ischemic stroke. Although conditioned medium obtained from human amniotic mesenchymal stem cells (hAMSC-CM) has been reported to exert protective effect against stroke, detailed knowledge about its possible molecular mechanisms is not still completely available. The present study was designed to investigate whether hAMSC-CM can modulate FoxO1 and Wnt/β-catenin signaling pathway after ischemic stroke to create neuroprotective effects. Middle cerebral artery occlusion (MCAO) model with male Wistar rats was used to evaluate the effects of hAMSC-CM on activities of FoxO1, Wnt/β-catenin signaling pathway, and endogenous antioxidant system and apoptotic cell death. The results demonstrated that induction of MCAO significantly reduced activities of FoxO1, Wnt/β-catenin signaling pathway, and endogenous antioxidant system and enhanced apoptotic cell death (P < 0.05). In addition, treatment by hAMSC-CM immediately after cerebral reperfusion resulted in significantly reduced infarct size and increased activities of FoxO1, Wnt/β-catenin signaling pathway, and restoring endogenous antioxidant system and suppressing apoptotic cell death (P < 0.05). Likewise, increased activity of Wnt/β-catenin signaling pathway resulted in suppressing the neuroinflammation by inhibiting the expression of TNF-α and increasing the expression of IL-10. These findings demonstrate that hAMSC-CM can be considered as an excellent candidate in the treatment of acute ischemic stroke in clinical routine.

Intratracheal Transplantation of Amnion-Derived Mesenchymal Stem Cells Ameliorates Hyperoxia-Induced Neonatal Hyperoxic Lung Injury via Aminoacyl-Peptide Hydrolase

Background and Objectives

Bronchopulmonary dysplasia (BPD) has major effects in premature infants. Although previous literature has indicated that mesenchymal stem cells (MSCs) can alleviate lung pathology in BPD newborns and improve the survival rate, few research have been done investigating significantly differentially expressed genes in the lungs before and after MSCs therapy. The aim of this study is to identify differentially expressed genes in lung tissues before and after hAD-MSC treatment.

Methods and Results

Human amnion-derived MSCs (hAD-MSCs) were cultured and met the MSCs criteria for cell phenotype and multidirectional differentiation. Then we confirmed the size of hAD-MSCs-EXOs and their expressed markers. An intratracheal drip of living cells showed the strongest effect on NHLI compared to cellular secretions or exosomes, both in terms of ameliorating pulmonary edema and reducing inflammatory cell infiltration. Through gene chip hybridization, PCR, and western blotting, acylaminoacyl-peptide hydrolase (APEH) expression was found to be significantly decreased under hyperoxia, and significantly increased after hAD-MSC treatment.

Conclusions

The intratracheal transplantation of hAD-MSCs ameliorated NHLI in neonatal rats through APEH.

Fibroblast growth factor 2-induced human amniotic mesenchymal stem cells combined with autologous platelet rich plasma augmented tendon-to-bone healing

Objective

The purpose of this study was to explore the effect of fibroblast growth factor 2 (FGF-2) on collagenous fibre formation and the osteogenic differentiation of human amniotic mesenchymal stem cells (hAMSCs) in vitro, as well as the effect of FGF-2–induced hAMSCs combined with autologous platelet-rich plasma (PRP) on tendon-to-bone healing in vivo.

Methods

In vitro, hAMSCs were induced by various concentrations of FGF-2 (0, 10, 20, and 40 ​ng/ml) for 14 days, and the outcomes of ligamentous differentiation and osteogenic differentiation were detected by quantitative real-time reverse transcription PCR, Western blot, immunofluorescence, and picrosirius red staining. In addition, a lentivirus carrying the FGF-2 gene was used to transfect hAMSCs, and transfection efficiency was detected by quantitative real time reverse transcription PCR (qRT-PCR) and Western blot. In vivo, the effect of hAMSCs transfected with the FGF-2 gene combined with autologous PRP on tendon-to-bone healing was detected via histological examination, as well as biomechanical analysis and radiographic analysis.

Results

In vitro, different concentrations of FGF-2 (10, 20, and 40 ​ng/ml) all promoted the ligamentous differentiation and osteogenic differentiation of hAMSCs, and the low concentration of FGF-2 (10 ​ng/ml) had a good effect on differentiation. In addition, the lentivirus carrying the FGF-2 gene was successfully transfected into hAMSCs with an optimal multiplicity of infection (MOI) (50), and autologous PRP was prepared successfully. In vivo, the hAMSCs transfected with the FGF-2 gene combined with autologous PRP had a better effect on tendon-to-bone healing than the other groups (p ​< ​0.05), as evidenced by histological examination, biomechanical analysis, and radiographic analysis.

Conclusion

hAMSCs transfected with the FGF-2 gene combined with autologous PRP could augment tendon-to-bone healing in a rabbit extra-articular model.

The translational potential of this article

hAMSCs transfected with the FGF-2 gene combined with autologous PRP may be a good clinical treatment for tendon-to-bone healing, especially for acute sports-related tendon–ligament injuries.

Human amniotic mesenchymal stem cells alleviate paraquat-induced pulmonary fibrosis in rats by inhibiting the inflammatory response

AIMS

To investigate the therapeutic effects of human amniotic mesenchymal stem cells (hAMSCs) on paraquat (PQ)-induced pulmonary fibrosis in rats and investigate the inflammatory mechanisms.

MAIN METHODS

hAMSCs were identified by morphological, flow cytometry and immunocytochemistry. A pulmonary fibrosis model was induced by administering PQ to rats. The hAMSCs group was treated with hAMSCs after 6 h of PQ poisoning. At 21 days after hAMSCs transplantation, lungs were harvested for H&E, Masson and immunohistochemical staining to evaluate pulmonary histopathology, collagen deposition, CD3+ cell infiltration and hAMSCs colonization. Arterial blood was used for lactic acid analysis and venous blood was used to detect TNF-α, IL-6, and TGF-β1 by ELISA method.

KEY FINDINGS

hAMSCs can improve the lung structure and decrease collagen deposition induced by PQ. The membranes of CD3+ T cell in the PQ group were round and complete, while that in the hAMSCs group rats exhibited punctate or diffuse staining. In addition, the CD3+ cell was decreased by hAMSCs administration, and MAB1281-positive cells were detected in lung of hAMSCs group rats. The survival rate of the hAMSCs group was significantly higher than that of the PQ group at 21 days after injection. TNF-α, IL-6, TGF-β1 and lactic acid were significantly decreased by hAMSCs administration.

SIGNIFICANCE

hAMSCs have a significant therapeutic effect on pulmonary fibrosis induced by acute PQ poisoning and can improve survival rate in rats. Furthermore, hAMSCs administration can improve lung histopathology and reduce collagen deposition by reducing inflammatory CD3+ T cell infiltration, inflammatory cytokine expression and lactic acid levels.

Human amniotic mesenchymal stem cells improve the follicular microenvironment to recover ovarian function in premature ovarian failure mice

Background

Many adult women younger than 40 years old have premature ovarian failure (POF) and infertility. Previous studies confirmed that different tissue-derived stem cells could restore ovarian function and folliculogenesis in chemotherapy-induced POF mice. The aim of this study was to explore the therapeutic efficacy and underlying mechanisms of human amniotic mesenchymal stem cells (hAMSCs) transplantation for hydrogen peroxide-induced ovarian damage.

Methods

Bilateral ovaries of female mice were burned with 10% hydrogen peroxide to establish a POF model. After 24 h of treatment, hAMSCs and diethylstilbestrol were administered to POF mice by intraperitoneal injection and intragastric administration, respectively. After either 7 or 14 days, ovarian function was evaluated by the oestrus cycle, hormone levels, ovarian index, fertility rate, and ovarian morphology. The karyotype was identified in offspring by the G-banding technique. hAMSCs tracking, immunohistochemical staining, and real-time polymerase chain reaction (PCR) were used to assess the molecular mechanisms of injury and repair.

Results

The oestrus cycle was recovered after hAMSCs transplantation at 7 and 14 days. Oestrogen levels increased, while follicle-stimulating hormone levels decreased. The ovarian index, fertility rate, and population of follicles at different stages were significantly increased. The newborn mice had no obvious deformity and showed normal growth and development. The normal offspring mice were also fertile. The tracking of hAMSCs revealed that they colonized in the ovarian stroma. Immunohistochemical and PCR analyses indicated that changes in proteins and genes might affect mature follicle formation.

Conclusions

These results suggested that hAMSCs transplantation can improve injured ovarian tissue structure and function in oxidatively damaged POF mice. Furthermore, the mechanisms of hAMSCs are related to promoting follicular development, granulosa cell proliferation, and secretion function by improving the local microenvironment of the ovary.

Hyaluronic acid promotes osteogenic differentiation of human amniotic mesenchymal stem cells via the TGF-β/Smad signalling pathway

AIMS

This study investigated the effects of hyaluronic acid (HA), a commonly used osteogenic medium referred to as DAG, and the combined administration of HA and DAG (CG) on the osteogenic differentiation of human amniotic mesenchymal stem cells (hAMSCs), and the underlying mechanism.

MAIN METHODS

The phenotype of hAMSCs was detected by flow cytometry and immunocytochemical staining. Alkaline phosphatase (ALP) and calcium deposition assays were employed for evaluating the osteogenic differentiation of hAMSCs. The expression of osteogenesis-related genes and proteins was determined by quantitative reverse transcription PCR (qRT-PCR) and Western blotting, respectively. Meanwhile, the molecular mechanism of osteogenic differentiation of hAMSCs was detected by PCR array and qRT-PCR.

KEY FINDINGS

The results showed that treatment with CG could significantly stimulate hAMSC ALP activity and calcium deposition compared to treatment with DAG, while HA had little effect. The expression of osteogenesis-related molecules and stemness-related molecules was up-regulated at the mRNA and protein levels in all three groups, and this up-regulation was most significant in the CG group. In addition, treatment with CG significantly increased the gene expressions involved in regulation of the TGF-β/Smad signalling pathway compared to treatment with DAG. Furthermore, the pro-osteogenic differentiation effects as well as the up-regulated expression of genes observed in the CG treatment group were significantly inhibited when the cells were pre-treated with SB431542, an inhibitor of the TGF-β/Smad pathway.

SIGNIFICANCE

These results suggest that HA in combination with DAG could significantly enhance the osteogenic differentiation of hAMSCs, potentially via the TGF-β/Smad signalling pathway.

MiR-429 improved the hypoxia tolerance of human amniotic cells by targeting HIF-1α

MicroRNA-429(miR-429) plays an important role in mesenchymal stem cells. Hypoxia-inducible factor 1α (HIF-1α) is a nuclear transcription factor that regulates the proliferation, apoptosis and tolerance to hypoxia of mesenchymal stem cells. HIF-1α is also a target gene of miR-429. We investigated whether miR-429 plays a role in hypoxia tolerance with HIF-1α in human amniotic mesenchymal stem cells (hAMSCs). The expression of miR-429 was increased by hypoxia in hAMSCs. miR-429 expression resulted in decreased HIF-1α protein level, but little effect on HIF-1α mRNA. While overexpression of HIF-1α increased the survival rate and exhibited anti-apoptosis effects in hAMSCs under hypoxia, co-expression of miR-429 reduced survival and increased apoptosis. However, miR-429 silencing with HIF-1α overexpression stimulated cell survival and reduced apoptosis. Co-expression of HIF-1α and miR-429 reduced VEGF and Bcl-2 proteins and increased Bax and C-Caspase-3 levels in hAMSCs under hypoxia compared with cells expressing only HIF-1α; cells with HIF-1α overexpression and miR-429 silencing showed the opposite effects. These results indicate that HIF-1α and angomiR-429 reciprocally antagonized each other, while HIF-1α and antagomiR-429 interacted with each other to regulate survival and apoptosis in hAMSCs under hypoxia. miR-429 increased VEGF and Bcl-2 protein levels and decreased Bax and cleaved Caspase-3 protein levels by promoting the synthesis of HIF-1α. These results indicate that miR-429 negatively regulates the survival and anti-apoptosis ability of hAMSCs by mediating HIF-1α expression and improves the ability of hAMSCs to tolerate hypoxia.

Human amniotic mesenchymal stem cells improve ovarian function in natural aging through secreting hepatocyte growth factor and epidermal growth factor

Background

Although many reports show that various kinds of stem cells have the ability to recover function in premature ovarian aging, few studies have looked at stem cell treatment of natural ovarian aging (NOA). We designed this experimental study to investigate whether human amniotic mesenchymal stem cells (hAMSCs) retain the ability to restore ovarian function, and how hAMSCs work in this process.

Methods

To build the NOA mouse model, the mice were fed for 12–14 months normally with young fertile female mice as the normal control group (3–5 months old). Hematoxylin and eosin staining permitted follicle counting and showed the ovarian tissue structure. An enzyme-linked immunosorbent assay was used to detect the serum levels of the sex hormones estradiol (E2), anti-mullerian hormone (AMH), and follicle-stimulating hormone (FSH). The proliferation rate and marker expression level of human ovarian granule cells (hGCs) (ki67, AMH, FSH receptor, FOXL2, and CYP19A1) were measured by flow cytometry (FACS). Cytokines (growth factors) were measured by a protein antibody array methodology. After hepatocyte growth factor (HGF) and epidermal growth factor (EGF) were co-cultured with hGCs, proliferation (ki67) and apoptosis (Annexin V) levels were analyzed by FACS. After HGF and EGF were injected into the ovaries of natural aging mice, the total follicle numbers and hormone levels were tested.

Results

After the hAMSCs were transplanted into the NOA mouse model, the hAMSCs exerted a therapeutic activity on mouse ovarian function by improving the follicle numbers over four stages. In addition, our results showed that hAMSCs significantly promoted the proliferation rate and marker expression level of ovarian granular cells that were from NOA patients. Meanwhile, we found that the secretion level of EGF and HGF from hAMSCs was higher than other growth factors. A growth factor combination (HGF with EGF) improved the proliferation rate and inhibited the apoptosis rate more powerfully after a co-culture with hGCs, and total follicle numbers and hormone levels were elevated to a normal level after the growth factor combination was injected into the ovaries of the NOA mouse model.

Conclusions

These findings provide insight into the notion that hAMSCs play an integral role in resistance to NOA. Furthermore, our present study demonstrates that a growth factor combination derived from hAMSCs plays a central role in inhibiting ovarian aging. Therefore, we suggest that hAMSCs improve ovarian function in natural aging by secreting HGF and EGF.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0781-9) contains supplementary material, which is available to authorized users.

Different therapeutic effects of cells derived from human amniotic membrane on premature ovarian aging depend on distinct cellular biological characteristics

BACKGROUND

Many reports have shown that various kinds of stem cells have the ability to recover premature ovarian aging (POA) function. Transplantation of human amniotic epithelial cells (hAECs) improves ovarian function damaged by chemotherapy in a mice model. Understanding of how to evaluate the distinct effects of adult stem cells in curing POA and how to choose stem cells in clinical application is lacking.

METHODS

To build a different degrees of POA model, mice were administered different doses of cyclophosphamide: light dose (70 mg/kg, 2 weeks), medium dose (70 mg/kg, 1 week; 120 mg/kg, 1 week), and high dose (120 mg/kg, 2 weeks). Enzyme-linked immunosorbent assay detected serum levels of sex hormones, and hematoxylin and eosin staining allowed follicle counting and showed the ovarian tissue structure. DiIC₁₈(5)-DS was employed to label human amniotic mesenchymal stem cells (hAMSCs) and hAECs for detecting the cellular retention time in ovaries by a live imaging system. Proliferation of human ovarian granule cells (ki67, AMH, FSHR, FOXL2, and CYP19A1) and immunological rejection of human peripheral blood mononuclear cells (CD4, CD11b, CD19, and CD56) were measured by flow cytometry (fluorescence-activated cell sorting (FACS)). Distinction of cellular biological characteristics between hAECs and hAMSCs was evaluated, such as collagen secretory level (collagen I, II, III, IV, and VI), telomerase activity, pluripotent markers tested by western blot, expression level of immune molecules (HLA-ABC and HLA-DR) analyzed by FACS, and cytokines (growth factors, chemotactic factors, apoptosis factors, and inflammatory factors) measured by a protein antibody array methodology.

RESULTS

After hAMSCs and hAECs were transplanted into a different degrees of POA model, hAMSCs exerted better therapeutic activity on mouse ovarian function in the high-dose administration group, promoting the proliferation rate of ovarian granular cells from premature ovarian failure patients, but also provoking immune rejection. Meanwhile, our results showed that the biological characteristics of hAMSCs were superior to hAECs, but not to expression of immune molecules.

CONCLUSIONS

These results suggest that hAMSCs are a more effective cell type to improve ovarian function than hAECs. Meanwhile, this distinct effect is attributable to cellular biological characteristics of hAMSCs (telomerase activity, expression level of pluripotent markers, cytokine and collagen secretion) that are superior to hAECs, except for immunological rejection. Sufficient consideration of cell properties is warranted to move forward to more effective clinical therapy.

[In vitrodifferentiation of human amniotic mesenchymal stem cells into ligament fibroblasts after induced by transforming growth factor β 1 and vascular endothelial growth factor]

Objective

To investigate whether human amniotic mesenchymal stem cells (hAMSCs) have the characteristics of mesenchymal stem cells (MSCs) and the differentiation capacity into ligament fibroblasts in vitro.

Methods

The hAMSCs were separated through trypsin and collagenase digestion from placenta, the phenotypic characteristics of hAMSCs were detected by flow cytometry, the cytokeratin-19 (CK-19) and vimentin expression of hAMSCs were tested through immunofluorescence staining. The hAMSCs at the 3rd passage were cultured with L-DMEM/F12 medium containing transforming growth factor β ₁ (TGF-β ₁) and vascular endothelial growth factor (VEGF) as the experimental group and with single L-DMEM/F12 medium as the control group. The morphology of hAMSCs was observed by inverted phase contrast microscope; the cellular activities and ability of proliferation were examined by cell counting kit-8 (CCK-8) method; the ligament fibroblasts related protein expressions including collagen type I, collagen type III, Fibronectin, and Tenascin-C were detected by immunofluorescence staining; specific mRNA expressions of ligament fibroblasts and angiogenesis including collagen type I, collagen type III, Fibronectin, α-smooth muscle actin (α-SMA), and VEGF were measured by real-time fluorescence quantitative PCR.

Results

The hAMSCs presented monolayer and adherent growth under inverted phase contrast microscope; the flow cytometry results demonstrated that hAMSCs expressed the MSCs phenotypes; the immunofluorescence staining results indicated the hAMSCs had high expression of the vimentin and low expression of CK-19; the hAMSCs possessed the differentiation ability into the osteoblasts, chondroblasts, and lipoblasts. The CCK-8 results displayed that cells reached the peak of growth curve at 7 days in each group, and the proliferation ability in the experimental group was significantly higher than that in the control group at 7 days ( P<0.05). The immunofluorescence staining results showed that the expressions of collagen type I, collagen type III, Fibronectin, and Tenascin-C in the experimental group were significantly higher than those in the control group at 5, 10, and15 days after culture ( P<0.05). The real-time fluorescence quantitative PCR results revealed that the mRNA relative expressions had an increasing tendency at varying degrees with time in the experimental group ( P<0.05). The relative mRNA expressions of collagen type I, collagen type III, Fibronectin, α-SMA, and VEGF in the experimental group were significantly higher than those in the control group at the other time points ( P<0.05), but no significant difference was found in the relative mRNA expressions of collagen type I, collagen type III, and VEGF between 2 groups at 5 days ( P>0.05).

Conclusion

The hAMSCs possesses the characteristics of MSCs and good proliferation ability which could be chosen as seed cell source in tissue engineering. The expressions of ligament fibroblasts and angiogenesis related genes could be up-regulated, after induction in vitro, and the synthesis of ligament fibroblasts related proteins could be strengthened. In addition, the application of TGF-β ₁ and VEGF could be used as growth factors sources in constructing tissue engineered ligament.