Isorhamnetin Exerts Antifibrotic Effects by Attenuating Platelet-Derived Growth Factor-BB-induced HSC-T6 Cells Activation via Suppressing PI3K-AKT Signaling Pathway

Background: Currently, liver fibrosis is growing worldwide; unfortunately, there is no definite cure for this disease. Hence, understanding the molecular pathways involved in the development of liver fibrosis can help to find a proper treatment. In this study, we aimed to evaluate the effects of isorhamnetin as an antifibrotic agent on platelet-derived growth factor (PDGF)-BB-activated hepatic stellate cells (HSC)-T6 cells in a concentration-dependent manner. We have also attempted to assess signaling pathways that may affect liver fibrosis. Methods: PDGF-BB was used to activate the HSC-T6 rat hepatic stellate cell line. The activated cells were treated with Isorhamnetin for 24 h. Finally, we compared the mRNA expression level of COLA1 and α-SMA and also the level of phosphorylated AKT protein with the control group. Results: The obtained data revealed a significant increase in the expression level of the COLA1 and α-SMA genes (p > 0.05), as well as phosphorylated AKT protein, in the cells treated with PDGF-BB. In addition, 75 and 100 µM concentrations of Isorhamnetin markedly declined the COLA1 and α-SMA expression and also the phosphorylated AKT protein level in the HSC-T6 cells. Conclusion: Our findings suggest that Isorhamnetin decreases HSC-T6 activation, the expression of COLA1 and α-SMA, in vitro, which could act as an antifibrotic element to reduce and treat liver fibrosis disease.

Effects of exosomes of mesenchymal stem cells on cholesterol-induced hepatic fibrogenesis.

Objectives: Free cholesterol in the diet can cause liver fibrosis by accumulating in Hepatic stellate cells (HSCs). The rate of mortality of this disease is high worldwide and there is no definite remedy for it, but might be treated by anti-fibrotic therapies. MSCs-derived exosomes are known as the new mechanism of cell-to-cell communication, showing that exosomes can be used as a new treatment. In this study, we investigated the ability of exosomes of WJ-MSCs as a new remedy to reduce cholesterol-induced liver fibrosis in the LX2 cell line. Materials and Methods: MSCs were isolated from Wharton's jelly of the umbilical cord and the exosomes were extracted. The LX2 cell line was cultured in DMEM medium with 10% FBS, then cells were treated with 75 and 100 µM concentrations of cholesterol for 24 hr. The mRNA expression of TGF-ß, αSMA, and collagen1α genes, and the level of Smad3 protein were measured to assess liver fibrosis. Results: Cholesterol increased the expression of TGF-ß, αand -SMA, and collagen1α genes by increasing the phosphorylation of the Smad3 protein. Treatment with Exosomes significantly reduced the expression of TGF-ß, α-SMA, and collagen1α genes (fibrosis genes). Treatment with exosomes prevented the activation of HSCs by inhibiting the phosphorylation of the Smad3 protein. Conclusion: The exosomes of WJ-MSCs can inhibit the TGFß/Smad3 signaling pathway preventing further activation of HSCs and progression of liver fibrosis. So, the exosomes of WJ-MSCs s could be introduced as a treatment for liver failure.