[Effects of PTHrP and Notch signaling on the proliferation of epiphysis stem cells].

Objective: To study the regulation of the proliferation of epiphysis stem cells by the PTHrP (parathyroid hormone related peptide) and Notch signaling systems.

Methods: An organ culture system of femurs of SD rat in 24 h after birth was employed. PTHrP (1 - 34) was used as the activator of the PTHrP signaling pathway and PTHrP (7 - 34) as the antagonist of PTH (parathyroid hormone)-receptor.

17β-Estradiol promotes cell proliferation in rat osteoarthritis model chondrocytes via PI3K/Akt pathway.

Osteoarthritis (OA) is the most common cause of musculoskeletal pain and disability. The importance of chondrocytes in the pathogenesis of OA is unequivocal. 17β-estradiol (E2) has a potential protective effect against OA.