Objective

We investigated the effect of berberine, a natural plant product that can activate AMP-activated protein kinase (AMPK), on Osteoarthritis (OA) development and associated pain in mice.

Design

Human primary knee chondrocytes were utilized to investigate how AMPK is activated by berberine. Both global knockout (KO) of AMPKα1 and congenic wild type (WT) mice were subjected to the post-traumatic OA through destabilization of medial meniscus (DMM) surgery. Two weeks after surgery, the mice were randomly divided into two groups with one group receiving berberine chloride daily via drinking water and were sacrificed at 6 and 12 weeks after surgery. OA severity was assessed by histological and histomorphometric analyses of cartilage degradation, synovitis, and osteophyte formation. OA-associated pain behavior was also determined. Immunohistochemistry (IHC) analyses were carried out to examine changes in AMPK signaling.

Results

Berberine induced phosphorylation of AMPKα (Thr172) via liver kinase B1 (LKB1), the major upstream kinase of AMPK, in chondrocytes in vitro. Both WT and AMPKα1KO developed OA and associated pain post DMM surgery. However, treatment with berberine significantly reduced severity of OA and associated pain in WT but not AMPKα1KO mice. IHC analysis of WT DMM knee cartilage further revealed that berberine inhibited concomitant loss of expression and phosphorylation of AMPKα and expression of SIRT1 and SIRT3, suggesting an important role of activation of AMPK signaling in mediating beneficial effect of berberine.

Conclusions

Berberine acts through AMPK to reduce joint structural damage and pain associated with post-traumatic OA in mice in vivo.

中文翻译：

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口服小檗碱通过 AMP 活化蛋白激酶 (AMPK) 限制小鼠创伤后骨关节炎的发展和相关疼痛

客观的

我们研究了小檗碱（一种可以激活 AMP 活化蛋白激酶 (AMPK) 的天然植物产品）对小鼠骨关节炎 (OA) 发展和相关疼痛的影响。

设计

人类原代膝关节软骨细胞被用来研究 AMPK 如何被小檗碱激活。AMPKα1 的全局敲除 (KO) 和同类野生型 (WT) 小鼠均通过内侧半月板 (DMM) 手术的去稳定化进行创伤后 OA。手术后两周，将小鼠随机分为两组，一组每天通过饮水接受氯化小檗碱，并在手术后第 6 周和第 12 周处死。通过软骨退化、滑膜炎和骨赘形成的组织学和组织形态学分析评估 OA 严重程度。还确定了 OA 相关的疼痛行为。进行免疫组织化学 (IHC) 分析以检查 AMPK 信号传导的变化。

结果

小檗碱在体外软骨细胞中通过肝激酶 B1 (LKB1)（AMPK 的主要上游激酶）诱导 AMPKα (Thr172) 磷酸化。WT 和 AMPKα1KO 在 DMM 手术后都出现了 OA 和相关疼痛。然而，小檗碱治疗显着降低了 WT 小鼠的 OA 严重程度和相关疼痛，但对 AMPKα1KO 小鼠没有影响。WT DMM 膝关节软骨的 IHC 分析进一步揭示，小檗碱抑制伴随的 AMPKα 表达和磷酸化以及 SIRT1 和 SIRT3 表达的丧失，表明 AMPK 信号通路的激活在介导小檗碱的有益作用中具有重要作用。

结论

Berberine 通过 AMPK 作用于小鼠体内，减少与创伤后 OA 相关的关节结构损伤和疼痛。