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.

Kidney and lung tissue modifications after BDL-induced liver injury in mice are associated with increased expression of IGFBPrP1 and activation of the NF-κB inflammation pathway.

BACKGROUND: Hepatorenal and hepatopulmonary syndrome are common clinical diseases; however, their mechanisms have not been fully elucidated. Our aim was to determine whether liver injury by bile duct ligation (BDL) causes modifications in kidney and lung tissue in mice, and to explore the possible mechanism of these changes. METHODS: BDL in mice was used as a research model. Pathologic changes of liver, kidney, and lung tissue were observed by hematoxylin-eosin (H&E) staining. The expression of IGFBPrP1, NF-κB, TNF-α, and IL-6 were investigated in liver, kidney, and lung tissue by immunohistochemical staining and western blot. The correlation between IGFBPrP1 and NF-κB, TNF-α, and IL-6 protein expression in liver, kidney, and lung tissues of each group was analyzed by the Pearson method. RESULTS: H&E staining showed, after BDL administration in mice, different degrees of inflammatory change in liver, kidney, and lung tissues of mice in each group. The results of immunohistochemical staining and western blot analysis showed increased expressions of IGFBPrP1, NF-κB, TNF-α, and IL-6 after BDL. Pearson correlation analysis showed that IGFBPrP1 positively correlated with the expressions of NF-κB, TNF-α, and IL-6. CONCLUSION: Liver injury caused by bile duct ligation can lead to kidney and lung tissue injury in mice. The mechanism of injury may be related to the high expression of liver injury factor IGFBPrP1, transcription factor NF-κB, proinflammatory cytokine TNF-α, and IL-6 in kidney and lung tissue. Moreover, an increased expression level of IGFBPrP1 may be accompanied by the activation of the NF-κB inflammatory pathway.

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.