[Osteopractic total flavone promoting rat extra-articular tendon-bone healing through mTOR pathway].

OBJECTIVE: To explore function and related molecular mechanism of osteopractic total flavone (OTF) on tendon healing in rats. METHODS: Ten male rats aged for 8 weeks were collected and weighted from 180 to 220 g. Tendon stem cells were cultivated, the third tendon stem cells were used for experiment. OTP treated with 0, 0.1, 1, 10 ng/ml were added into tendon stem cells, and expression change of ALP, Runx2, OCN, VEGF, P-S6, P-4E/BP1 were detected after 14 days. Forty male rats aged for 8 weeks (weighted 180 to 220 g) were established extra-articular tendon-bone transplanting healing model, and divided into experimental group and control group. Experimental group were treated with OTF(100 mg·kg⁻¹·d⁻¹), while control group was treated by normal saline with the same volume. Tendon-bone healing degree were detected by biomechanical testing at 3 and 6 weeks after surgery, histological detection were applied to detect tendon-bone healing and number of new vessles. RESULTS: After treated by OTP, ALP staining and active index detection showed there were statistical differences among 0, 0.1, 1, 10 ng/ml group. After 14 days' cultivation, western blotting results showed mTOR downstream marker protein P-S6 protein expression were gradually increased with increase of density of OTP, expression of P-4E/BP1 was reduced, while expression of Runx2, OCN, VEGF were increased. Biological detection results showed that there was no significant difference in mechanical strength between experimental group(0.78±0.05) N/mm and control group (0.51±0.02) N/mm at 3 weeks after surgery, while mechanical strength in experimental group (1.36±0.09) N/mm was higher than control group (1.01±0.08) N/mm at 6 weeks after surgery. Histological results showed maturity of tendon-bone surface cell were higher at 3 and 6 weeks in experimental group, sharpey fiber growth more density, calcification extent of mesenchyme was high, and new bone, vessels were increased. CONCLUSIONS: OTF could promote osteogenic differentiation of tendon stem cells through mTOR signaling in vitro, and stimulate tendon-bone healing in bone tunnel and enhance connection quality between tendon and bone.

Tenuigenin promotes the osteogenic differentiation of bone mesenchymal stem cells in vitro and in vivo.

Osteoporosis, which is a systemic skeletal disease characterized by low bone mineral density and microarchitectural deterioration of bone quality, is a global and increasing public health problem. Recent studies have suggested that Tenuigenin (TEN), a class of native compounds with numerous biological activities such as anti-resorptive properties, exerts protective effects against postmenopausal bone loss. The present study aims to investigate the osteogenic effects of TEN on bone mesenchymal stem cells (BMSCs) in vitro and in vivo. Alkaline phosphatase (ALP) activity/staining, Alizarin red staining and the expression of osteogenic markers, including runt-related transcription factor 2, osterix, osteocalcin, collagen Iα1, ß-catenin and glycogen synthase kinase-3ß were investigated in primary femoral BMSCs from C57/BL6 mice cultured under osteogenic conditions for 2 weeks to examine the effects of TEN. An ovariectomized (OVX) mouse model was used to investigate the effect of TEN treatment for 3 months in vivo. We found that ALP activity, mineralized nodules and the expression of osteogenic markers were increased and WNT/ß-catenin signaling was enhanced in vitro and in vivo. Bone parameters, including trabecular thickness, trabecular number and bone mineral density were higher in the OVX+TEN group than in control OVX mice. Our results suggest the therapeutic potential of TEN for the treatment of patients with postmenopausal osteoporosis.