The Glucagon-Like Peptide-1 Receptor Agonist Exendin-4 Inhibits Lipopolysaccharide-Induced Osteoclast Formation and Bone Resorption via Inhibition of TNF-α Expression in Macrophages
Exendin-4 suppressed expression of LPS-induced tumor necrosis factor- (TNF-) α and receptor activator of NF-kB ligand (RANKL) in vivo. TNF-α and RANKL mRNA levels in mouse calvariae were determined using real-time RT-PCR. Total RNA was isolated from mouse calvariae after 5-day daily supracalvarial injections with PBS, LPS (100 μg/day) with or without exendin-4 (20 μg/day), and exendin-4 alone (20 μg/day). TNF-α and RANKL mRNA levels were normalized to the expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Data is expressed as means ± SD. The statistical significance of differences was determined using Scheffe’s test (;, ).