Exosomes derived from human umbilical cord mesenchymal stem cells ameliorate experimental non-alcoholic steatohepatitis via Nrf2/NQO-1 pathway.

No approved effective therapy for non-alcoholic steatohepatitis (NASH) is currently available. Exosomes derived from mesenchymal stem cells (MSCs) perform the functions such as inhibiting inflammation, anti-oxidative stress, regulating immunity, but it is not clear whether human umbilical cord mesenchymal stem cells (hUC-MSCs) exosomes protect against NASH through Nrf2/NQO-1 pathway. Therefore, this study was conducted to investigate the effects of hUC-MSCs exosomes on NASH through Nrf2/NQO-1 pathway in vivo and in vitro. C57BL/6J male mice were fed with high fat and high cholesterol diet (HFHC) and methionine choline deficiency diet (MCD). Mice were treated with or without hUC-MSCs exosomes by tail intravenous injection. The liver histology, lipid metabolism and oxidative stress were evaluated. HepG2 and AML12 cells were incubated with palmitic acid (PA) and MCD conditioned medium, respectively. Then the therapeutic effect of hUC-MSCs exosomes in steatotic cells was evaluated. To elucidate the signaling pathways, the Nrf2-specific blocker ML385 was applied to intervene in vitro. In NASH models, hUC-MSCs exosomes attenuated steatosis in hepatocytes, altered the abnormal expression of lipid-related genes including SREBP-1c, PPAR-α, Fabp5, CPT1α, ACOX and FAS, suppressed the hepatic inflammatory responses by decreasing the expression of F4/80+ macrophages, CD11c+ macrophages as well as the content of TNF-α and IL-6. hUC-MSCs exosomes also inhibited oxidative stress by reducing the level of MDA, CYP2E1 and ROS, increasing the activity of SOD and GSH in hepatocytes. Notably, hUC-MSCs exosomes enhanced the protein ratio of p-Nrf2/Nrf2 and the protein expression of NQO-1. Moreover, in vitro, the therapeutic effects of hUC-MSCs exosomes on lipid deposition and ROS were reversed by ML385. Also, ML385 reduced the protein expression of p-Nrf2 and NQO-1 in vitro. Nrf2/NQO-1 antioxidant signaling pathway may play a key role in the treatment of NASH by hUC-MSCs exosomes.

Kang Y ，Song Y ，Luo Y ，Song J ，Li C ，Yang S ，Guo J ，Yu J ，Zhang X ... -  《-》

Human umbilical cord mesenchymal stromal cell-derived exosomes protect against MCD-induced NASH in a mouse model.

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are increasingly being studied in clinical trials of end-stage liver disease because of their good tissue repair and anti-inflammatory effects. hUC-MSC exosomes are vesicles with spherical structures secreted by cells that produce them. The diameter of exosomes is much smaller than that of hUC-MSCs, suggesting that exosomes might be a novel and safer therapeutic product of mesenchymal stem cells. As exosomes have been suggested to have biochemical functions similar to those of hUC-MSCs, this study investigated the efficiency of hUC-MSC-derived exosomes in protecting against nonalcoholic steatohepatitis using an MCD-induced mouse model. Human umbilical cord mesenchymal stem cell-derived exosomes were extracted and purified. The effect of these exosomes on disease progression in an MCD-induced nonalcoholic steatohepatitis mouse model was investigated. The results showed that UC-MSC exosomes intravenously transplanted into mice with MCD-induced NASH improved MCD-induced body weight loss and liver damage in a mouse model. Additionally, the inflammatory cytokines in liver tissue were reduced, which may be caused by exosome-induced macrophage anti-inflammatory phenotypes both in vitro and in vivo. In addition, UC-MSC exosomes reversed PPARα level in ox-LDL-treated hepatocytes in vitro and in NASH mouse liver, which had been downregulated. UC-MSC exosomes alleviate MCD-induced NASH in mice by regulating the anti-inflammatory phenotype of macrophages and by reversing PPARα protein expression in liver cells, which holds great potential in NASH therapy.

Shi Y ，Yang X ，Wang S ，Wu Y ，Zheng L ，Tang Y ，Gao Y ，Niu J ... -  《Stem Cell Research & Therapy》

Human umbilical cord mesenchymal stem cell-derived exosomes attenuate neuroinflammation and oxidative stress through the NRF2/NF-κB/NLRP3 pathway.

We investigated whether human umbilical cord mesenchymal stem cell (hUC-MSC)-derived exosomes bear therapeutic potential against lipopolysaccharide (LPS)-induced neuroinflammation. Exosomes were isolated from hUC-MSC supernatant by ultra-high-speed centrifugation and characterized by transmission electron microscopy and western blotting. Inflammatory responses were induced by LPS in BV-2 cells, primary microglial cultures, and C57BL/6J mice. H2 O2 was also used to induce inflammation and oxidative stress in BV-2 cells. The effects of hUC-MSC-derived exosomes on inflammatory cytokine expression, oxidative stress, and microglia polarization were studied by immunofluorescence and western blotting. Treatment with hUC-MSC-derived exosomes significantly decreased the LPS- or H2 O2 -induced oxidative stress and expression of pro-inflammatory cytokines (IL-6 and TNF-α) in vitro, while promoting an anti-inflammatory (classical M2) phenotype in an LPS-treated mouse model. Mechanistically, the exosomes increased the NRF2 levels and inhibited the LPS-induced NF-κB p65 phosphorylation and NLRP3 inflammasome activation. In contrast, the reactive oxygen species scavenger NAC and NF-κB inhibitor BAY 11-7082 also inhibited the LPS-induced NLRP3 inflammasome activation and switched to the classical M2 phenotype. Treatment with the NRF2 inhibitor ML385 abolished the anti-inflammatory and anti-oxidative effects of the exosomes. hUC-MSC-derived exosomes ameliorated LPS/H2 O2 -induced neuroinflammation and oxidative stress by inhibiting the microglial NRF2/NF-κB/NLRP3 signaling pathway.

Che J ，Wang H ，Dong J ，Wu Y ，Zhang H ，Fu L ，Zhang J ... -  《-》

Curcumin preconditioned mesenchymal stem cells derived exosomes transplantation ameliorate and protect against non- alcoholic steatohepatitis by regulation the expression of key genes of inflammation and oxidative stress.

Mesenchymal stem cells (MSCs) derived exosomes (MSCs/Exo) is considered a new strategy in cell free regenerative therapy. Curcumin preconditioning of MSCs reported to improve the anti- inflammatory and immunomodulatory properties of MSCs. We investigated the efficacy of exosome (Exo) obtained from curcumin-preconditioned MSCs (MSCs/Exo-Cur) vs. MSC/Exo without curcumin to ameliorate and prevent recurrence of non-alcoholic fatty liver (NASH) disease. In-vivo, methionine/choline-deficient diet (MCD) induced mice non-alcoholic fatty liver disease (NASH) were injected with MSCs/Exo without curcumin or MSCs/Exo-Cur with curcumin. We found that mice treated with MSCs/Exo-Cur had significantly ameliorated steatosis, inflammation, as evaluated by the reduced fibrosis in histopathological examination, decreased the serum level of liver enzymes (p < 0.001), liver triglycerides (TG) (p < 0.001) and cholesterol (Ch) (p < 0.001) and increased the lipid peroxidation (p < 0.001) compared to MSCs/Exo-treated mice. These effects remained for 3 months after treatment in MSCs/Exo-Cur-treated mice while features of NASH returned in MSCs/Exo-treated group. In vitro, HepG2 cells were cultured with palmitic acid (PA) and treated with MSCs/Exo or MSCs/Exo-Cur: the MSCs/Exo-Cur exposure reversed the lipotoxic effect from 4.5 to 1.7 fold vs 4.0 fold in MSCs/Exo and oxidative stress in PA-treated HepG2 cells (p < 0.001). We found that MSCs/Exo-Cur regulated the key markers of inflammatory and oxidative stress, genes responsible for fibrogenesis of the liver, key genes of lipid synthesis and transport. Interestingly, MSCs/Exo-Cur significantly down regulated the ASK-JNK-BAX genes involved in mitochondrial stress and apoptosis compared to MSCs/Exo (p < 0.001). Our study indicated that exosomes derived from curcumin preconditioned MSCs were able to ameliorate and protect against recurrence of NASH and regulated inflammatory, oxidative stress and mitochondrial-dependent apoptosis ASK-JNK-BAX genes.

Tawfeek GA ，Kasem HA 《-》

Human umbilical cord-derived mesenchymal stem cell-exosomal miR-627-5p ameliorates non-alcoholic fatty liver disease by repressing FTO expression.

Non-alcoholic fatty liver disease (NAFLD) is a spectrum of liver disorders. Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs)-based therapy is currently considered to be an effective treatment for NAFLD. The present study aimed to determine whether hUC-MSCs-exosomes have a hepatoprotective effect on NAFLD. We constructed NAFLD rat model by high-fat high-fructose feeding. Liver cells (L-O2) were treated with palmitic acid (PA) to mimic NAFLD model. NAFLD rats and PA-treated L-O2 cells were treated with hUC-MSCs-exosomes, and then we determined the influence of exosomes on liver damage and glucose and lipid metabolism in vivo and in vitro. We found that hUC-MSCs-exosomes exhibited an up-regulation of miR-627-5p. Exosomal miR-627-5p promoted cell viability and repressed apoptosis of PA-treated L-O2 cells. Exosomal miR-627-5p also enhanced the expression of G6Pc, PEPCK, FAS and SREBP-1c and suppressed PPARα expression in PA-treated L-O2 cells. Moreover, miR-627-5p interacted with fat mass and obesity-associated gene (FTO) and inhibited FTO expression in L-O2 cells. MiR-627-5p-enriched exosomes improved glucose and lipid metabolism in L-O2 cells by targeting FTO. In vivo, exosomal miR-627-5p ameliorated insulin tolerance, liver damage, glucose and lipid metabolism and reduced lipid deposition in NAFLD rats. Exosomal miR-627-5p also reduced body weight, liver weight, and liver index (body weight/liver weight) in NAFLD rats. In conclusion, these data demonstrate that HUC-MSCs-derived exosomal miR-627-5p improves glucose and lipid metabolism and alleviate liver damage by repressing FTO expression, thereby ameliorating NAFLD progression. Thus, hUC-MSCs-exosomes may be a potential treatment for NAFLD.

Cheng L ，Yu P ，Li F ，Jiang X ，Jiao X ，Shen Y ，Lai X ... -  《Human Cell》