锌转运蛋白ZIP8 在骨关节炎中的表达及其机制研究

目的:探讨锌转运蛋白ZIP8在骨关节炎患者中的表达及其对软骨细胞生长及基质金属蛋白酶(MMPs)表达的影响。方法:收集20例骨关节炎患者(OA组)和20例非骨关节炎患者(对照组)血清和软骨组织;采用原子吸收分光光度计测定患者血清和软骨组织中锌离子的表达水平;MTT方法检测软骨细胞的生长活力;采用小RNA干扰沉默ZIP8基因的表达;实时荧光定量PCR方法检测ZIP8及金属基质蛋白酶MMP3、MMP9、MMP12和MMP13等基因的m RNA表达水平;蛋白免疫印迹检测ZIP8及MMP3、MMP9、MMP12和MMP13等蛋白的表达水平。结果:OA组的血清和软骨组织中的锌离子浓度明显高于对照组(P0.01)。OA组软骨组织中ZIP8的m RNA(P0.05)和蛋白(P0.01)表达水平显著高于对照组。ZIP8小RNA干扰片段可以有效的沉默ZIP的基因表达(P0.01);沉默ZIP8的表达促进骨关节炎患者来源的软骨细胞的生长(P0.05),并且降低基质金属蛋白酶包括MMP3,MMP9,MMP12和MMP13的表达水平(P0.05)。结论:ZIP8与骨关节炎密切相关,沉默ZIP8的表达可以提高软骨细胞的生长活力,并且抑制基质金属蛋白酶的表达,为骨关节炎的治疗提供了新的靶点。

Expression of Zinc Transporter ZIP8 in Osteoarthritis and the Underlying Mechanism

Objective:To investigate the expression of zinc transporter ZIP8 in osteoarthritis (OA) and its effect on the growth and viability of chondrocyte and the expression of matrix metalloproteinases (MMPs).Methods:The serum and cartilage tissues were collected from 20 osteoarthritis patients (OA group) and 20 non-osteoarthritis patients (control group). Concentrations of zinc-ion in serum and cartilage tissues were measured by atomic absorption spectrophotometer. Cell growth and viability was detected by MTT assay. ZIP8 gene silencing was achieved by small interfering RNA (siRNA). The mRNA expression levels of ZIP8, MMP3, MMP9, MMP12 and MMP13 were measured by quantitative real-time PCR. The protein expression levels of ZIP8, MMP3, MMP9, MMP12 and MMP13 were detected by Western blot analysis.Results:The concentrations of zinc-ion were elevated in the serumand cartilage tissues of OA group as compared with control group (P<0.01). The mRNA (P<0.05) and protein (P<0.01) expression of ZIP8 were both significantly increased in cartilage tissues of OA group compared with control group. ZIP8 siRNA effectively silenced the expression of ZIP8 in chondrocytes (P<0.01). ZIP8 silencing significantly promoted cell growth of chondrocytes isolated from OA patients (P<0.05) and markedly inhibited the expression of MMPs including MMP3, MMP9, MMP12 and MMP13 (P<0.05).Conclusion:ZIP8 is closely related to osteoarthritis, and ZIP8 gene expression silencing was capable of increasing cell growth and viability of chondrocytes and decreasing gene expression of MMPs which provides a novel target for treatment of OA in future.