Overexpression of CRABP2 inhibits dexamethasone-induced apoptosis in human osteoblast cells

Background: The purpose of the current study was to explore the role and underlying mechanism of cellular retinoic acid binding protein 2 (CRABP2) in dexamethasone (DEX)-induced Apoptosis in human osteoblast cells.

Methods: GSE10311 was downloaded from the Gene Expression Omnibus (GEO) database to identify the differentially expressed genes (DEGs) by the limma/R package. Primary human osteoblast was isolated and treated with different concentration of DEX (0, 10^-8, 10^-7, 10^-6, 10^-5, and 10^-4 mol/L), and cell viability and flow cytometry were used to detect cell proliferation and Apoptosis. A CRABP2 overexpression plasmid (oe-CRABP2) was used to overexpress CRABP2, and western blotting was conducted to detect protein expression.

Results: We found that CRABP2 was downregulated in the DEX-treated group. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses indicated that DEGs were associated with PI3K/Akt signaling pathway. DEX downregulated CRABP2 gene and protein expression, inhibited viability, and induced human osteoblast Apoptosis. Overexpression of CRABP2 reversed DEX-induced Apoptosis in human osteoblast. Moreover, overexpression of CRABP2 delayed the progression of DEX-induced osteonecrosis of the femoral head (ONFH) animal model.

Conclusion: In conclusion, CRABP2 is effective at inhibiting DEX-induced human osteoblast Apoptosis and delayed ONFH progression.