MEOX2 Participates in Hepatic Stellate Cells-Induced Liver Fibrosis by Regulating the PI3K/AKT Signaling Pathway.

Background: Hepatic stellate cells (HSCs) serve as the crucial accelerating factor in the progression of liver fibrosis (LF). In contrast to HSCs, adult-derived human liver stem/progenitor cells (ADHLSCs) exhibit greater potency in terms of differentiation and proliferation, rendering them highly applicable in LF treatment. The objective of this study is to identify new therapeutic targets for LF by comparing differentially expressed genes (DEGs) between ADHLSCs and HSCs.

Methods: We investigated DEGs between ADHLSCs and HSCs using the GSE49995 dataset obtained from the Gene Expression Omnibus (GEO) database, aiming to identify new therapeutic targets for LF. Subsequently, we activated HSCs to delve deeper into the mesenchyme homeobox 2 (MEOX2), PH domain Leucine-rich repeat protein phosphatase (PHLPP), and Phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathways in LF progression, employing platelet-derived growth factor (PDGF), and conducted infection with Overexpression (OE)- and shRNA- (sh-) lentiviruses. Cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay, while cell proliferation was evaluated through 5-ethynyl-2'-deoxyuridine (EdU) staining and flow cytometry. Relative mRNA expression levels were determined via qPCR. Western blot analysis was performed to measure protein expression levels, and the regulatory role of MEOX2 was investigated using dual luciferase reporter assays.

Results: We identified 332 DEGs that were down-regulated and 201 DEGs that were up-regulated between ADHLSCs and HSCs. Notably, expression in ADHLSCs was significantly reduced. These DEGs primarily participated in the collagen-containing extracellular matrix and the PI3K/AKT signaling pathway. MEOX2 could inhibit cancer cell proliferation via the PI3K/AKT signaling pathway. Additionally, the JASRPAR2022 database predicted the target gene of MEOX2. Our results indicated that OE- significantly inhibited HSCs' cell vitality and proliferation. Further analysis revealed that MEOX2 binds to promoters, thereby up-regulating its transcription. This action led to the inhibition of p-AKT expression, consequently reducing HSC proliferation and slowing the progression of LF.

Conclusions: MEOX2 up-regulates PHLPP expression and inhibits AKT phosphorylation, thereby reducing the cell activity and proliferation ability of HSCs and inhibiting the progression of LF.