Yang Yue, Wang Yang, Kong Yawei, Zhang Xiaoning, Zhang He, Gang Yi, Bai Lunhao
Department of Orthopedic Surgery, Shengjing Hospital of China Medical University, Shenyang, China.
Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, China.
Front Pharmacol. 2018 Jun 6;9:598. doi: 10.3389/fphar.2018.00598. eCollection 2018.
The anti-inflammatory and antioxidant capacity of carnosine (CAR) has been investigated in autoimmune diseases. The aim of this study was to evaluate the potential protective effects of oral CAR supplements to ameliorate type 2 diabetes mellitus (T2DM)-induced osteoarthritis (OA) in rats and its mechanism. Seventy male Sprague-Dawley rats were randomly divided into the control group (CG, = 10) and the T2DM group ( = 60). A rat model of T2DM was established using a high fat diet and streptozotocin (30 mg/kg, i.p.). The 41 rats that developed T2DM were chosen and randomly divided into four groups: T2DM-induced OA group (OAG, = 11), and the T2DM-induced OA with low, moderate, and high-doses of CAR for 8 weeks group (CAR-L, CAR-M, and CAR-H, = 10). After 13 weeks, all rats were evaluated by enzyme-linked immunosorbent assay (ELISA), histology, immunohistochemistry, and western blotting. Fibroblast-like synoviocytes (FLSs) were obtained from the knee joints of all rats. The effects of CAR on the inflammatory response in interleukin (IL)-1β-stimulated FLSs under a high glucose environment were evaluated by real-time quantitative polymerase chain reaction, western blotting, flow cytometry, and immunofluorescence. The results of ELISA (IL-1β and tumor necrosis factor-α), the histological evaluation (Mankin and OARSI score), western blotting [COL2A1, matrix metalloproteinase (MMP)-3, MMP-13, IL-1β, and nuclear factor-kappaB (NF-κB) p65], and immunohistochemistry (COL2A1, MMP-3, and MMP-13) indicated that oral CAR attenuated the development of T2DM-induced OA and suppressed the inflammatory response. Moreover, CAR alleviated MMP-3 and MMP-13 expression levels by decreasing reactive oxygen species content and suppressing nuclear translocation of NF-κB p65 on IL-1β-induced FLSs in a high glucose environment. These findings indicate that oral CAR had chondroprotective effects on T2DM-induced OA through the reactive oxygen species (ROS)/NF-κB pathway.
肌肽（CAR）的抗炎和抗氧化能力已在自身免疫性疾病中得到研究。本研究的目的是评估口服CAR补充剂对改善大鼠2型糖尿病（T2DM）诱导的骨关节炎（OA）的潜在保护作用及其机制。70只雄性Sprague-Dawley大鼠被随机分为对照组（CG，n = 10）和T2DM组（n = 60）。采用高脂饮食和链脲佐菌素（30 mg/kg，腹腔注射）建立T2DM大鼠模型。选择41只发生T2DM的大鼠并随机分为四组：T2DM诱导的OA组（OAG，n = 11），以及T2DM诱导的OA分别给予低、中、高剂量CAR处理8周的组（CAR-L、CAR-M和CAR-H，n = 10）。13周后，通过酶联免疫吸附测定（ELISA）、组织学、免疫组织化学和蛋白质印迹法对所有大鼠进行评估。从所有大鼠的膝关节获取成纤维样滑膜细胞（FLS）。通过实时定量聚合酶链反应、蛋白质印迹法、流式细胞术和免疫荧光评估CAR对高糖环境下白细胞介素（IL）-1β刺激的FLS中炎症反应的影响。ELISA结果（IL-1β和肿瘤坏死因子-α）、组织学评估（Mankin和OARSI评分）、蛋白质印迹法[Ⅱ型胶原（COL2A1）、基质金属蛋白酶（MMP）-3、MMP-13、IL-1β和核因子-κB（NF-κB）p65]以及免疫组织化学（COL2A1、MMP-3和MMP-13）表明，口服CAR可减轻T2DM诱导的OA的发展并抑制炎症反应。此外，CAR通过降低高糖环境下IL-1β诱导的FLS中的活性氧含量并抑制NF-κB p65的核转位，减轻了MMP-3和MMP-13的表达水平。这些发现表明，口服CAR通过活性氧（ROS）/NF-κB途径对T2DM诱导的OA具有软骨保护作用。
