Inhibition of LTBP2 Suppresses High Glucose-Induced Proliferation, Fibrosis, and Inflammation in Glomerular Mesangial Cells by Disrupting the PI3K/Akt/NF-κB Pathway

Abstract

Latent transforming growth factor-β binding protein-2 (LTBP2) plays a significant role in tissue fibrosis. This research aimed to elucidate whether LTBP2 influences the progression of diabetic nephropathy (DN) through the phosphatidylinositol 3-kinases/protein kinase B (PI3K/Akt)/nuclear factor kappa-B (NF-κB) pathway.

The HBZY-1 cells were exposed to high glucose to create diabetic nephropathy cell model. LTBP2 levels were examined by Western blot and immunofluorescence. After verifying the transfection efficiency of si-LTBP2, cell counting kit-8, 5-ethynyl-2-deoxyuridine staining, Western blot, flow cytometry and immunofluorescence were utilized to assess the proliferation, apoptosis and fibrosis of HBZY-1 cells, respectively. Collagen deposition was also detected by Sirius red staining, and inflammatory factors levels were determined by Elisa. PI3K/Akt/NF-κB pathway activators were applied to explore whether LTBP2 silencing could play a role in DN by modulating this pathway.

After treatment with high glucose, the expression of LTBP2 was elevated in HBZY-1 cells. LTBP2 silencing hindered the aberrant proliferation of HBZY-1 cells, with no significant effect on apoptosis; meanwhile, it reduced fibrosis, decreased collagen content, and decreased inflammatory factors levels in HBZY-1 cells. Following treatment with high glucose, the PI3K, Akt, and p65 phosphorylation levels were increased, whereas silencing LTBP2 reduced them. Activators of the PI3K/Akt/NF-κB pathway weakened the inhibition of LTBP2 silencing on cell proliferation, fibrosis, and inflammation.

In conclusion, silencing of LTBP2 weakened the proliferation, fibrosis, and inflammation of HBZY-1 cells treated with high glucose by hindering the PI3K/Akt/NF-κB pathway. This research offers a new reference for the targeted therapy of DN.