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

AIMS: Despite 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 METHODS: We 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 FINDINGS: Transplant of hAMSC-islet organoids results in remarkably better glycemic control, an enhanced glucose tolerance, and a higher ß 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 ß cells, which ultimately promotes the synthesis, folding and secretion of insulin, respectively. SIGNIFICANCE: hAMSC-islet organoids can evidently increase the efficiency of islet engraftment and might develop into a promising alternative for the clinical treatment of T1DM.

MicroRNA miR-19b-3p mediated G protein γ subunit 7 (GNG7) loss contributes lung adenocarcinoma progression through activating Hedgehog signaling.

G protein γ subunit 7 (GNG7) is a subunit of heterotrimeric G protein. It has been demonstrated low expressed GNG7 in various cancers. Nevertheless, the role of GNG7 in lung adenocarcinoma (LUAD) remains unclear. In the present study, GNG7 expression in LUAD tissues and cell lines was analyzed by RT-qPCR, western blot and immunohistochemical. Kaplan-Meier analysis was performed for determining the prognostic value of GNG7 expression. Then, the function of GNG7 in LUAD progression was examined by cell proliferation, invasion and mouse xenograft assays. In addition, the underlying biological mechanisms of GNG7 in LUAD progression were explored via the bioinformatics analysis and experimental validation. We found GNG7 was markedly down-regulated in LUAD tissues and cell lines. Clinically, low expression of GNG7 was associated with the dismal prognosis of LUAD patients. Gain-of-function analysis showed that GNG7 overexpression inhibited proliferation and invasion of LUAD cell in vitro, and compromised tumor formation ability in vivo. Besides, mechanistic study revealed that overexpression of GNG7 affected the progression of LUAD via inhibiting activation of Hedgehog signaling. Moreover, bioinformatics prediction and experimental verification confirmed that GNG7 was targeted by miR-19b-3p, which was elevated expression in LUAD and promoting the progression of LUAD. Furthermore, rescue experiments demonstrated that GNG7 reintroduction weakened miR-19b-3p-mediated aggressive tumor phenotypes of LUAD cells. These findings suggested miR-19b-3p/GNG7 axis contributed to the progression of LUAD through Hedgehog signaling, which might be a potential therapeutic target for LUAD treatment.

Exosomes derived from human umbilical cord mesenchymal stem cells alleviate acetaminophen-induced acute liver failure through activating ERK and IGF-1R/PI3K/AKT signaling pathway.

This study aimed to investigate the therapeutic potential of human umbilical cord mesenchymal stem cells derived exosomes (hUCMSC-Exo) in acute liver failure (ALF) in mice as well as its underlying mechanism. We found that a single tail vein administration of hucMSC-Exo effectively enhanced the survival rate, inhibited apoptosis in hepatocytes, and improved liver function in APAP-induced mouse model of ALF. Furthermore, the deletion of glutathione (GSH) and superoxide dismutase (SOD), generation of malondialdehyde (MDA), and the over production of cytochrome P450 E1 (CYP2E1) and 4-hydroxynonenal (4-HNE) caused by APAP were also inhibited by hucMSC-Exo, indicating that hucMSC-Exo inhibited APAP-induced apoptosis of hepatocytes by reducing oxidative stress. Moreover, hucMSC-Exo significantly down-regulated the levels of inflammatory cytokines IL-6, IL-1ß, and TNF-α in APAP-treated livers. Western blot showed that hucMSC-Exo significantly promoted the activation of ERK1/2 and IGF-1R/PI3K/AKT signaling pathways in APAP-injured LO2 cells, resulting in the inhibition of apoptosis of LO2 cells. Importantly, PI3K inhibitor LY294002 and ERK1/2 inhibitor PD98059 could reverse the function of hucMSC-Exo on APAP-injured LO2 cells in some extent. Our results suggest that hucMSC-Exo offer antioxidant hepatoprotection against APAP in vitro and in vivo by inhibitiing oxidative stress-induced apoptosis via upregulation of ERK1/2 and PI3K/AKT signaling pathways.

Human amniotic mesenchymal stem cells inhibit hepatocellular carcinoma in tumour-bearing mice.

Hepatocellular carcinoma (HCC) is the third leading cause of the cancer-related death in the world. Human amniotic mesenchymal stem cells (hAMSCs) have been characterized with a pluripotency, low immunogenicity and no tumorigenicity. Especially, the immunosuppressive and anti-inflammatory effects of hAMSCs make them suitable for treating HCC. Here, we reported that hAMSCs administrated by intravenous injection significantly inhibited HCC through suppressing cell proliferation and inducing cell apoptosis in tumour-bearing mice with Hepg2 cells. Cell tracking experiments with GFP-labelled hAMSCs showed that the stem cells possessed the ability of migrating to the tumorigenic sites for suppressing tumour growth. Importantly, both hAMSCs and the conditional media (hAMSC-CM) have the similar antitumour effects in vitro, suggesting that hAMSCs-derived cytokines might be involved in their antitumour effects. Antibody array assay showed that hAMSCs highly expressed dickkopf-3 (DKK-3), dickkopf-1 (DKK-1) and insulin-like growth factor-binding protein 3 (IGFBP-3). Furthermore, the antitumour effects of hAMSCs were further confirmed by applications of the antibodies or the specific siRNAs of DKK-3, DKK-1 and IGFBP-3 in vitro. Mechanically, hAMSCs-derived DKK-3, DKK-1 and IGFBP-3 markedly inhibited cell proliferation and promoted apoptosis of Hepg2 cells through suppressing the Wnt/ß-catenin signalling pathway and IGF-1R-mediated PI3K/AKT signalling pathway, respectively. Taken together, our study demonstrated that hAMSCs possess significant antitumour effects in vivo and in vitro and might provide a novel strategy for HCC treatment clinically.

Human amniotic mesenchymal stem cells and their paracrine factors promote wound healing by inhibiting heat stress-induced skin cell apoptosis and enhancing their proliferation through activating PI3K/AKT signaling pathway.

BACKGROUND: Increasing evidence has shown that mesenchymal stem cells (MSCs) yield a favorable therapeutic benefit for thermal burn skin wounds. Human amniotic MSCs (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating skin wounds. However, the exact effects of hAMSCs on the healing of thermal burn skin wounds and their potential mechanisms are not explored. METHODS: hAMSCs were isolated from amniotic membrane and characterized by RT-PCR, flow cytometry, immunofluorescence, and tumorigenicity test. We assessed the effects of hAMSCs and hAMSC conditional medium (CM) on wound healing in a deep second-degree burn injury model of mice. We then investigated the biological effects of hAMSCs and hAMSC-CM on the apoptosis and proliferation of heat stress-injured human keratinocytes HaCAT and dermal fibroblasts (DFL) both in vivo and in vitro. Next, we explored the underlying mechanisms by assessing PI3K/AKT and GSK3ß/ß-catenin signaling pathways in heat injured HaCAT and DFL cells after hAMSCs and hAMSC-CM treatments using PI3K inhibitor LY294002 and ß-catenin inhibitor ICG001. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may activate PI3K/AKT signaling pathway. RESULTS: Our results showed that hAMSCs expressed various markers of embryonic stem cells and mesenchymal stem cells and have low immunogenicity and no tumorigenicity. hAMSC and hAMSC-CM transplantation significantly promoted thermal burn wound healing by accelerating re-epithelialization with increased expression of CK19 and PCNA in vivo. hAMSCs and hAMSC-CM markedly inhibited heat stress-induced apoptosis in HaCAT and DFL cells in vitro through activation of PI3K/AKT signaling and promoted their proliferation by activating GSK3ß/ß-catenin signaling. Furthermore, we demonstrated that hAMSC-mediated activation of GSK3ß/ß-catenin signaling was dependent on PI3K/AKT signaling pathway. Antibody array assay showed that a panel of cytokines including PAI-1, C-GSF, periostin, and TIMP-1 delivered from hAMSCs may contribute to the improvement of the wound healing through activating PI3K/AKT signaling pathway. CONCLUSION: Our results demonstrated that hAMSCs and hAMSC-CM efficiently cure heat stress-induced skin injury by inhibiting apoptosis of skin cells and promoting their proliferation through activating PI3K/AKT signaling pathway, suggesting that hAMSCs and hAMSC-CM may provide an alternative therapeutic approach for the treatment of skin injury.

NEAT1 contributes to ox-LDL-induced inflammation and oxidative stress in macrophages through inhibiting miR-128.

Long noncoding RNAs (lncRNA) have been recognized as significant regulators in the progression of atherosclerosis (AS). Oxidized low-density lipoprotein (ox-LDL) can induce macrophage inflammation and oxidative stress, that serves important roles in AS. However, the exact function of lncRNA NEAT1 and its possible molecular mechanism in AS remain unclear. Here, we concentrated on the roles and molecular mechanisms of NEAT1 in AS development. In our current study, we observed that NEAT1 was elevated by ox-LDL in a dose-dependent and time-dependent manner. RAW264.7 cell survival was greatly enhanced, and cell apoptosis was significantly inhibited by LV-shNEAT1 transfection. In addition, knockdown of NEAT1 in RAW264.7 cells repressed CD36 expression and foam cell formation while NEAT1 overexpression shown an opposite process. Moreover, NEAT1 downregulation inhibited inflammation molecules including IL-6, IL-1ß, and TNF-α. Meanwhile, silencing of NEAT1 can also suppress reactive oxygen species (ROS) and malondialdehyde (MDA) levels with an enhancement of superoxide dismutase (SOD) activity in RAW264.7 cells. MicroRNAs are some short RNAs, and they can regulate multiple biological functions in many diseases including AS. Here, we found that miR-128 expression was remarkably decreased in ox-LDL-incubated RAW264.7 cells. Interestingly, miR-128 mimics was able to reverse AS-correlated events induced by overexpression of NEAT1. By using bioinformatics analysis, miR-128 was predicted as a target of NEAT1 and the correlation between them was validated in our study. Taken these together, it was implied that NEAT1 participated in ox-LDL-induced inflammation and oxidative stress in AS development through sponging miR-128.

Therapeutic efficiency of human amniotic epithelial stem cell-derived functional hepatocyte-like cells in mice with acute hepatic failure.

BACKGROUND: Hepatocyte transplantation has been proposed as an effective treatment for patients with acute liver failure (ALF), but its application is limited by a severe shortage of donor livers. Human pluripotent stem cells (hPSCs) have emerged as a potential cell source for regenerative medicine. Human amniotic epithelial stem cells (hAESCs) derived from amniotic membrane have multilineage differentiation potential which makes them suitable for possible application in hepatocyte regeneration and ALF treatment. METHODS: The pluripotent characteristics, immunogenicity, and tumorigenicity of hAESCs were studied by various methods. hAESCs were differentiated to hepatocyte-like cells (HLCs) using a non-transgenic and three-step induction protocol. ALB secretion, urea production, periodic acid-Schiff staining, and ICG uptake were performed to investigate the function of HLCs. The HLCs were transplanted into ALF NOD-SCID (nonobese diabetic severe combined immunodeficient) mouse, and the therapeutic effects were determined via liver function test, histopathology, and survival rate analysis. The ability of HLCs to engraft the damaged liver was evaluated by detecting the presence of GFP-positive cells. RESULTS: hAESCs expressed various markers of embryonic stem cells, epithelial stem cells, and mesenchymal stem cells and have low immunogenicity and no tumorigenicity. hAESC-derived hepatocytes possess the similar functions of human primary hepatocytes (hPH) such as producing urea, secreting ALB, uptaking ICG, storing glycogen, and expressing CYP enzymes. HLC transplantation via the tail vein could engraft in live parenchymal, improve the liver function, and protect hepatic injury from CCl4-induced ALF in mice. More importantly, HLC transplantation was able to significantly prolong the survival of ALF mouse. CONCLUSION: We have established a rapid and efficient differentiation protocol that is able to successfully generate ample functional HLCs from hAESCs, in which the liver injuries and death rate of CCl4-induced ALF mouse can be significantly rescued by HLC transplantation. Therefore, our results may offer a superior approach for treating ALF.

Differential analysis of clinical efficacy on patients with serious infection in ICU by different meropenem regimens.

To investigate the difference in clinical efficacy and safety of different meropenem regimens on patients with serious infection in ICU. Then, 228 patients with serious infection in ICU were divided by random into control group (intermittent administration in 1000mg/30min single dose) and research group (continuous administration in 200mg/10min +800mg/180min), respectively. The blood concentration of meropenem were recorded in two groups at different time points, and difference in treatment effectiveness, iconographic effectiveness, bacterial eradication rate, 28-day survival rate and many other clinical scoring indices (SOFA, APACHEII, CPIS, and SIRS) were compared between two groups. There were 212 patients completing the whole research, including 104 patients in research group and 108 patients in control group. The difference in treatment effectiveness (77.8% vs 53.7%), iconographic effectiveness (51.0% vs 18.5%), and 28-day survival rate (86.5% vs 64.8%) between two groups performed statistical significance (P<0.05). However, the difference in bacterial eradication rate (48.0% vs 46.3%) performed no statistical significance. Eight hours later, the difference in average blood concentration between two groups (9.61±3.63µg/ml vs 1.5±0.51µg/ml) showed statistical significance. Moreover, the difference in clinical scoring indices except APACHE II score between two groups performed statistical significance. It was helpful to maintain the blood concentration of meropenem by extending the transfusion time. Therefore, it could increase the clinical cure rate and 28-day survival of patients with serious infection in ICU, improve clinical indices, and reduce the usage amount of antibiotics.

ZnPPIX inhibits peritoneal metastasis of gastric cancer via its antiangiogenic activity.

Our previous study suggests that heme oxygenase-1 (HO-1) may play an important role in the metastasis of gastric cancer. Zinc protoporphyrin IX (ZnPPIX) is a special HO-1 inhibitor that inhibits the angiogenesis of pancreatic and lung cancer. In this study, we employed ZnPPIX to investigate the role of HO-1 in peritoneal metastasis of gastric cancer (PMGC) and explored the potential mechanism. We established animal model of PMGC by orthotopic implantation into nude mice of human gastric cancer cell line GC9811-P with high peritoneal metastasis potential. The mice were injected intraperitoneally with saline, CTX or ZnPPIX. Tumor microvessel density (MVD) in peritoneal metastatic nodules was determined by immunohistochemistry, and vascular endothelial growth factor (VEGF) level was determined by ELISA. We found that the number, volume, weight of peritoneal metastatic nodules and volume of seroperitoneum in ZnPPIX (4 mg/kg) group decreased remarkably compared with control group. MVD value and VEGF level of peritoneal metastatic tumor in ZnPPIX (4 mg/kg) group also decreased significantly, while the survival rate and survival time of the mice were higher than control group. ZnPPIX dose-dependently suppressed VEGF and GC9811-P induced angiogenesis. Furthermore, ZnPPIX suppressed VEGF induced reactive oxygen species production and ERK phosphorylation in human umbilical vein endothelial cells. In conclusion, our results suggest that HO-1 plays an important role in PMGC and ZnPPIX is an effective antitumor and antiangiogenic agent for PMGC.