Abstract:
OBJECTIVE To investigate the effect of the Tenghuang Jiangu capsule on matrix metabolism in rats with knee osteoarthritis and its molecular mechanism.
METHODS Sixty SD rats were randomly divided into the sham operation group, model group, positive control group(glucosamine sulfate: 0.17 g·kg−1), and high-, middle-, and low- dose treatment groups(Tenghuang Jiangu capsule: 0.36, 0.18, 0.09 g·kg−1), with 10 rats in each group. Knee osteoarthritis(KOA) rat model was made using a modified version of the Hulth method, excluding the sham operation group. After 6 weeks of modelling, glucosamine sulfate and the corresponding dosage of the Tenghuang Jiangu capsule were administered through the stomach, and 0.9% normal saline was administered through the stomach in the sham operation group and the model group. After 2 months of continuous intragastric administration of the above drugs, the knee joint grade of rats was observed using the Lequesne knee joint grade score; the gait change, joint range of motion, and joint swelling degree of rats were evaluated with the Lequesne knee joint grade score, the pathological morphology of the joint cartilage was observed through saffron solid green O staining, and preform quantitative OARSI scoring. Serum concentrations of core-binding factor subunit beta(Cbf-β), matrix metalloproteinase 13(MMP-13), tissue inhibitor of metalloproteinase 2(TIMP-2), type Ⅱ collagen terminal peptide(CTX-Ⅱ), platelet reactive protein disintegrin metallopeptidase 4(ADAMTS-4), and platelet reactive protein disintegrin metallopeptidase 5(ADAMTS-5) were detected by ELISA. The expression of AMP-activated protein kinase(AMPK), peroxidase proliferator-activated receptor γ coactivator 1α(PGC-1α), MMP-13 mRNA and protein in the articular cartilage were observed with RT-PCR and Western blotting.
RESULTS Compared with the sham-operated group, the serum Cbf-β, MMP-13, CTX-Ⅱ, ADAMTS-4, and ADAMTS-5 concentrations, and the MMP-13 mRNA and protein expression levels significant increased in the model group, the Lequesne MG score and the OARSI score also increased in the model group and low-dose groups, but serum TIMP-2 concentration significant decreased in the model group. The expression levels of PGC-1α and AMPK mRNA in the cartilage of the right knee joint also exhibited a downward trend(P<0.01). Compared with the model group, the concentration of ADAMTS-5 and TIMP-2 in the high-dose group exhibited a downward trend, while the TIMP-2 concentration exhibited an upward trend(P<0.01). The Lequesne MG score, OARSI score, and Cbf-β, CTX-Ⅱ, and ADAMTS-4 levels in the middle- and high-dose groups all showed a downward trend. The expression of the PGC-1α protein and its grey value in the cartilage tissue of the right knee joint exhibited an increasing trend(P<0.05 or P<0.01). The content of MMP-13 and MMP-13 mRNA, and protein expression in the low-, middle-, and high-dose groups of Tenghuang Jiangu capsule exhibited a downward trend, and the expression levels of AMPK and the PGC-1α mRNA in the cartilage tissue of the right knee joint also increased, the expression of the AMPK protein and its grey value in the cartilage tissue of the right knee joint exhibited an increasing trend(P<0.05 or P<0.01).
CONCLUSION Tenghuang Jiangu capsule delays the degeneration of the articular cartilage in KOA model rats, which may be related to maintaining the homeostasis of the articular cartilage matrix and reversing the damage of mitochondrial biogenesis, and the activation of the AMPK/PGC-1α signal pathway may play a key regulatory role.