[Regulation of JAK2/STAT3 signaling pathway by polydatin in the treatment of hormone-induced femoral head necrosis in rats].

Abstract

Objective: To explore the therapeutic effect of polygonum cuspidatum glycoside on steroid-induced osteonecrosis of the femoral head(SONFH) in rats and its potential mechanism of protecting bone tissue by regulating the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway(JAK2/STAT3).

Methods: Fifty male SD rats were randomly divided into control group, model group, low-dose polygonum cuspidatum glycoside group (polygonum cuspidatum glycoside-L), high-dose polygonum cuspidatum glycoside group (polygonum cuspidatum glycoside-H), and polygonum cuspidatum glycoside-H+Colivelin (JAK2/STAT3 pathway activator) group. SONFH model was induced by lipopolysaccharide and dexamethasone. The treatment groups were given polygonum cuspidatum glycoside orally(polygonum cuspidatum glycoside-L 10 mg·kg^-1, polygonum cuspidatum glycoside-H 20 mg·kg^-1, and the polygonum cuspidatum glycoside-H+Colivelin group was injected with Colivelin (1 mg·kg^-1) intraperitoneally once a day, while the control and model groups were given an equal volume of saline for 6 weeks. The observed indicators included serum calcium(Ca), serum phosphorus (P), alkaline phosphatase, and transforming growth factor β1(TGF-β1) levels, micro-CT scanning, hematoxylin-eosin staining, and Western blot detection of JAK2/STAT3 signaling pathway and osteogenic differentiation marker genes, including Runt-related transcription factor 2 (Runx2), bone morphogenetic protein 2 (BMP2), and osteopontin (OPN) protein expression.

Results: Compared with the model group, the trabecular bone area percentage in the polygonum cuspidatum glycoside-L and polygonum cuspidatum glycoside-H groups was significantly increased, and the empty lacunar rate was significantly decreased (P<0.05). Micro-CT analysis showed that the bone volume fraction, trabecular number, and thickness increased, and the trabecular separation decreased in the polygonum cuspidatum glycoside-treated groups(P<0.05). Serum biochemical tests found that the serum Ca and P concentrations in the polygonum cuspidatum glycoside-L and polygonum cuspidatum glycoside-H groups were restored, the alkaline phosphatase levels decreased, and the transforming growth factor β1 levels increased (P<0.05). Western blot analysis showed that polygonum cuspidatum glycoside significantly inhibited the activation of the JAK2/STAT3 signaling pathway in the model group and promoted the expression of osteogenic differentiation marker genes such as Runx2, BMP2, and OPN (P<0.05). Compared with the polygonum cuspidatum glycoside-H group, the improvements in the polygonum cuspidatum glycoside-H+Colivelin group were somewhat weakened, indicating the importance of the JAK2/STAT3 signaling pathway in the action of polygonum cuspidatum glycoside.

Conclusion: polygonum cuspidatum glycoside promotes osteogenic differentiation, improves bone microstructure, and has significant therapeutic effects on rat SONFH by regulating the JAK2/STAT3 signaling pathway.