Bone mesenchymal stem cells improve cholestatic liver fibrosis by targeting ULK1 to regulate autophagy through PI3K/AKT/mTOR pathway.

Cholestatic liver disease (CLD) is a severe disease, which can progress to liver cirrhosis, even liver cancer. Hepatic stellate cells (HSCs) activation plays a crucial role in CLD development. Bone mesenchymal stem cells (BMSCs) treatment was demonstrated to be beneficial in liver diseases. However, the therapeutic effect and mechanism of BMSCs on CLD are poorly known. In the present study, we investigated the therapeutic effects and underlying mechanisms of BMSCs transplantation in mouse models of bile duct ligation-induced cholestatic liver fibrosis (CLF). The results revealed that BMSCs significantly improved liver function and reduced the formation of fibrosis after portal vein transplantation. Mechanistically, after coculturing BMSCs and HSCs, we identified that BMSCs alleviated starvation-induced HSCs activation. Further, BMSCs inhibited HSCs activation by decreasing autophagy, and PI3K/AKT/mTOR pathway was involved in the regulation. More importantly, ULK1 is identified as the main autophagy-related gene regulated by BMSCs in HSCs autophagy. Overexpression of ULK1 reversed the suppression of HSCs autophagy by BMSCs. Collectively, our results provide a theoretical basis for BMSCs targeting ULK1 to attenuate HSCs autophagy and activation and suggest that BMSCs or ULK1 may be an alternative therapeutic approach/target for the treatment of CLF.

Arsenic disturbs neural tube closure involving AMPK/PKB-mTORC1-mediated autophagy in mice.

Arsenic exposure is a significant risk factor for folate-resistant neural tube defects (NTDs), but the potential mechanism is unclear. In this study, a mouse model of arsenic-induced NTDs was established to investigate how arsenic affects early neurogenesis leading to malformations. The results showed that in utero exposure to arsenic caused a decline in the normal embryos, an elevated embryo resorption, and a higher incidence of malformed embryos. Cranial and spinal deformities were the main malformation phenotypes observed. Meanwhile, arsenic-induced NTDs were accompanied by an oxidant/antioxidant imbalance manifested by elevated levels of reactive oxygen species (ROS) and decreased antioxidant activities. In addition, changes in the expression of autophagy-related genes and proteins (ULK1, Atg5, LC3B, p62) as well as an increase in autophagosomes were observed in arsenic-induced aberrant brain vesicles. Also, the components of the upstream pathway regulating autophagy (AMPK, PKB, mTOR, Raptor) were altered accordingly after arsenic exposure. Collectively, our findings propose a mechanism for arsenic-induced NTDs involving AMPK/PKB-mTORC1-mediated autophagy. Blocking autophagic cell death due to excessive autophagy provides a novel strategy for the prevention of folate-resistant NTDs, especially for arsenic-exposed populations.

Sodium alginate hydrogel integrated with type III collagen and mesenchymal stem cell to promote endometrium regeneration and fertility restoration.

A thinner endometrium has been linked to implantation failure, and various therapeutic strategies have been attempted to improve endometrial regeneration, including the use of mesenchymal stem cells (MSCs). However, low survival and retention rates of transplanted stem cells are main obstacles to efficient stem cell therapy in thin endometrium. Collagen type III is a key component of the extracellular matrix, plays a crucial role in promoting cell proliferation and differentiation, and has been identified as the major collagen expressed at the implantation site. Herein, composite alginate hydrogel containing recombinant type III collagen (rCo III) and umbilical cord mesenchymal stem cells are developed. rCo III serves as favorable bioactive molecule, displaying that rCo III administration promotes MSCs proliferation, stemness maintenance and migration. Moreover, rCo III administration enhances cell viability and migration of mouse endometrial stromal cells (ESCs). In a mouse model of thin endometrium, the Alg-rCo III hydrogel loaded with MSCs (MSC/Alg-rCo III) significantly induces endometrial regeneration and fertility enhancement in vivo. Further studies demonstrate that the MSC/Alg-rCo III hydrogel promoted endometrial function recovery partly by regulating mesenchymal-epithelial transition of ESCs. Taken together, the combination of Alg-rCo III hydrogel and MSCs has shown promising results in promoting endometrium regeneration and fertility restoration, and may provide new therapeutic options for endometrial disease.

The lncRNA NEAT1/miR-29b/Atg9a axis regulates IGFBPrP1-induced autophagy and activation of mouse hepatic stellate cells.

AIMS: Insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) promotes hepatic stellate cell (HSC) autophagy and activation. However, the underlying mechanism remains unknown. Noncoding RNAs (ncRNAs) including long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), have received increasing attention. We aimed to investigate the roles of the lncRNA nuclear enriched abundant transcript 1 (NEAT1), miR-29b, and autophagy related protein 9a (Atg9a), and their relationships with each other during IGFBPrP1-induced HSC autophagy and activation. MAIN METHODS: Levels of NEAT1, miR-29b, Atg9a, and autophagy were detected in adenovirus-mediated IGFBPrP1 (AdIGFBPrP1)-treated mouse liver tissue and immortalized mouse hepatic stellate cell line JS1 transfected with either AdIGFBPrP1 or siIGFBPrP1. In AdIGFBPrP1-treated JS1 cells, autophagy and activation were detected after altering NEAT1, miR-29b, or Atg9a levels. In AdIGFBPrP1-treated JS1 cells, relationships among NEAT1, miR-29b, and Atg9a were explored using dual-luciferase reporter assays, Western blot, qRT-PCR, and immunofluorescence. KEY FINDINGS: IGFBPrP1 increased levels of NEAT1, Atg9a, and autophagy while decreasing the level of miR-29b in mouse liver tissues and mouse HSCs. Moreover, NEAT1 increased HSC autophagy and activation while miR-29b decreased both processes. Atg9a also participated in IGFBPrP1-induced HSC autophagy and activation. Importantly, NEAT1, miR-29b, and Atg9a formed a NEAT1/miR-29b/Atg9a regulatory axis for IGFBPrP1-induced HSC autophagy and activation. SIGNIFICANCE: Our study unveiled the new NEAT1/miR-29b/Atg9a regulatory axis involved in IGFBPrP1-induced mouse HSC autophagy and activation. The study thus provides new insights in the pathogenesis and potential therapeutic strategies of liver fibrosis.

IGFBPrP1 accelerates autophagy and activation of hepatic stellate cells via mutual regulation between H19 and PI3K/AKT/mTOR pathway.

BACKGROUND: Our previous study found that insulin-like growth factor binding protein-associated protein (IGFBPrP1) drives hepatic stellate cells (HSCs) activation, and IGFBPrP1 and transforming growth factor ß1 (TGFß1) likely interact with each other to promote HSCs activation. TGFß1 reportedly promotes autophagy and contributes to HSCs activation; however, the mechanism between IGFBPrP1 and autophagy in liver fibrogenesis is yet unknown. Moreover, long noncoding RNA (lncRNA) H19 participates in autophagy regulation and plays a crucial function in liver fibrosis. AIMS: To define the relationship between IGFBPrP1 and autophagy and the role of H19 in IGFBPrP1-induced hepatic fibrosis. METHODS: IGFBPrP1 and autophagy were detected in bile duct ligation (BDL)-induced hepatic fibrosis. Adenovirus-mediated IGFBPrP1 was transfected into mouse liver and JS-1 cells with or without LY294002 or rapamycin to examine the effects of IGFBPrP1 on HSCs activation and autophagy as well as the PI3K/AKT/mTOR pathway. lncRNA H19 in liver fibrosis tissues and JS-1 cells induced by IGFBPrP1 were detected, then autophagy and HSCs activation level were detected in JS-1 cells by IGFBPrP1 with H19 overexpression or knowdown. RESULTS: IGFBPrP1 expression and autophagy level were concomitantly increased in liver tissue with BDL-induced hepatic fibrosis. Furthermore, we found that IGFBPrP1 stimulated autophagy and HSCs activation in vivo and in vitro, and PI3K/AKT/mTOR signaling pathway was involved in the regulation of autophagy by IGFBPrP1. In addition, H19 promoted autophagy by interacting with the PI3K/AKT/mTOR pathway in IGFBPrP1-induced HSCs activation. CONCLUSIONS: IGFBPrP1 promoted autophagy and contributed to HSCs activation via mutual regulation between H19 and the PI3K/AKT/mTOR pathway.

Insulin-like growth factor binding protein related protein 1 knockdown attenuates hepatic fibrosis via the regulation of MMPs/TIMPs in mice.

BACKGROUND: Previous research suggested that insulin-like growth factor binding protein related protein 1 (IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix (ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis. METHODS: Hepatic fibrosis was induced by thioacetamide (TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog (Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin (α-SMA), transforming growth factor ß 1 (TGFß1), collagen I, MMPs/TIMPs, Sonic Hedgehog (Shh), and glioblastoma family transcription factors (Gli1) were investigated by immunohistochemical staining and Western blotting analysis. RESULTS: We found that hepatic expression of IGFBPrP1, TGFß1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGFß1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance. CONCLUSIONS: Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGFß1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.