Yang Xiaobo, Chen Weiping, Zhao Xiang, Chen Linwei, Li Wanli, Ran Jisheng, Wu Lidong
The Second Affiliated Hospital of Zhejiang University, School of Medicine, Hangzhou, China .
DNA Cell Biol. 2018 Mar;37(3):271-277. doi: 10.1089/dna.2017.4048. Epub 2018 Jan 22.
Pyruvate kinase M2 (PKM2) has been wildly verified to modulate glycolysis in tumor cells. However, the role of PKM2 on the glycolysis of osteoarthritis (OA) chondrocytes is still unclear. In present study, we investigate the function of PKM2 on OA chondrocyte glycolysis and the collagen matrix generation in vitro. Results showed that PKM2 was upregulated in OA chondrocytes compared with healthy control chondrocytes. In OA chondrocytes, ATP expression was lower compared with healthy control chondrocytes. Loss-of-function experiment showed that PKM2 knockdown mediated by lentivirus transfection could significantly suppress the glucose consumption and lactate secretion levels and decrease glucose transporter-1 (Glut-1), lactate dehydrogenase A (LDHA), and hypoxia inducible factor 1-alpha (HIF-1α), indicating the inhibition of PKM2 knockdown on glycolysis. Moreover, Cell Counting Kit-8 (CCK-8), flow cytometry, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay showed that PKM2 knockdown inhibited OA chondrocyte proliferation and promoted the apoptosis. Western blot and immunocytochemical staining showed that PKM2 knockdown downregulated the expression levels of COL2A1 and SOX-9. In summary, our results conclude that PKM2 modulates the glycolysis and extracellular matrix generation, providing the vital role of PKM2 on OA pathogenesis and a novel therapeutic target for OA.
丙酮酸激酶M2（PKM2）已被广泛证实可调节肿瘤细胞中的糖酵解。然而，PKM2在骨关节炎（OA）软骨细胞糖酵解中的作用仍不清楚。在本研究中，我们在体外研究了PKM2对OA软骨细胞糖酵解和胶原基质生成的作用。结果显示，与健康对照软骨细胞相比，PKM2在OA软骨细胞中表达上调。在OA软骨细胞中，ATP表达低于健康对照软骨细胞。功能丧失实验表明，慢病毒转染介导的PKM2敲低可显著抑制葡萄糖消耗和乳酸分泌水平，并降低葡萄糖转运蛋白1（Glut-1）、乳酸脱氢酶A（LDHA）和缺氧诱导因子1α（HIF-1α），表明PKM2敲低对糖酵解有抑制作用。此外，细胞计数试剂盒8（CCK-8）、流式细胞术和末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）分析表明，PKM2敲低抑制了OA软骨细胞增殖并促进了细胞凋亡。蛋白质印迹和免疫细胞化学染色表明，PKM2敲低下调了COL2A1和SOX-9的表达水平。总之，我们的结果表明，PKM2调节糖酵解和细胞外基质生成，揭示了PKM2在OA发病机制中的重要作用以及OA的新治疗靶点。
