糖尿病大鼠肩关节病理改变及其机制

Pathological studies on the impact of diabetes on periarthritis of shoulder formation

目的 探讨糖尿病大鼠肩关节病理改变及其形成机制.方法 选取体质量为240～260 g之间的SPF级雄性SD大鼠45只,随机分为两组,即对照组（20只）和模型组（25只）.对照组采用维持饲料喂养.模型组持续高糖高脂饲料喂养1个月后,链脲佐菌素（STZ） 30 mg/kg注射诱导建立2型糖尿病模型（T2DM）.造模成功后,留取各组大鼠双侧肩关节软骨、滑膜及周围肌肉（包括肌腱）等软组织,行苏木素-伊红（HE）染色,在光镜下观察各部位组织形态学变化;酶联免疫吸附法检测各组血浆及肌肉前列腺素E-2（PGE-2）、转化生长因子-β1（TGF-β1）的含量;样本碱水解法检测肌腱羟脯氨酸（HYP）的含量;逆转录-聚合酶链反应（RT-PCR）检测上述指标mRNA的相对表达量.结果 模型组和对照组肩关节出现病理改变的比例分别为76.19％和10.00％,差异有统计学意义（P＜0.05）.两组出现病理改变的关节软骨、滑膜、肌腱的镜下特点基本相似,主要变现为关节软骨面粗糙,部分可见细胞外基质浅层裂开,软骨外观呈丝绒状;滑膜肥厚与纤维化,滑膜细胞肥大增生;肌腱中胶原纤维结构疏松而紊乱,部分断裂.模型组血浆及肌肉PGE-2的含量分别为（39.13±7.72）、（42.18±12.73） ng/L,较对照组（18.86±6.35）、（21.39±7.18）ng/L比较均升高（P＜0.05）.模型组血浆及肌肉TGF-β1的含量分别为（23.44 ±7.28）、（29.14 ±7.33） μg/L,较对照组（10.58 ±3.52）、（12.43 ±4.56） μg/L比较均升高（P＜0.05）.模型组与对照组肌腱HYP的含量分别为（119.42 ±27.18）、（64.19±10.45）μg/g,两者比较差异有统计学意义（P＜0.05）.模型组软组织中TGF-β1、PGE-2及HYP mRNA的相对表达量分别为5.78±0.90、8.29±1.76、13.89±3.18,明显高于对照组的1.89±0.27、3.06 ±0.60、7.22±2.05,差异有统计学意义（P＜0.05）.结论 T2DM可导致大鼠肩关节软骨、滑膜及周围肌肉等软组织出现炎性改变及纤维化,与肩周炎肩周软组织自然退变病理特点一致,可认为是肩周炎的成因之一.

Objective To explore the pathological changes and its formation mechanism in the shoulder joint of diabetic rats.Methods The 45 SPF male SD rats that weighing between 240 and 260 gram were randomly divided into two groups namely the control group （20） and the model group （25）.The control group maintained by general diet.The model group fed with high sugar and high fat diet for 1 month,after that streptozocin （STZ） 30 mg/kg were injected into rats aiming to induce the model of type 2 diabetes （T2DM）.After the success of modeling,take specimens from each rat group with bilateral shoulder cartilage,synovial membrane,surrounding muscles （including tendons）,and other soft tissues,observe morphologic-al changes of specimens under light microscopy after HE staining.Enzyme-linked immunosorbent assay was used to detect the prostaglandin E-2 （PGE-2） of plasma and muscle,and also transforming growth factor-beta 1 （TGF-β1） levels; sample based hydrolysis to detect tendon hydroxyproline （HYP） content; the expression of the above indicators relative mRNA were detected by reverse transcriptase-polymerase chain reaction （RT-PCR）.Results The shoulder pathological changes of model group and control group were 76.19% and 10.00% respectively,the difference was statistically significant （P 〈 0.05）.The pathological changes of articular cartilage,synovial membrane and tendons observed under microscope are similar,the main features are articular cartilage surface roughness,partly visible shallow crack of the extracellular matrix,velvet-like appearance of cartilage ; Synovial hypertrophy and fibrosis,synovial cell hypertrophy and the structure of tendon collagen fiber is loose,disorder and partial rupture.The PGE-2 content of plasma and muscle in model group were （39.13 ± 7.72）,（42.18 ± 12.73） ng/L respectively,compared with the control group （18.86 ±6.35）,（21.39 ±7.18） ng/L respectively,were increased （P 〈0.05）.The TGF-β1 level of plasma and muscle in model group were （23.44 ± 7.28）,（29.14 ± 7.33） μg/L respectively,compared with the control group （10.58 ± 3.52）,（12.43 ± 4.56） μg/L respectively,were elevated （P 〈0.05）.The HYP content of model group and control group were （119.42 ± 27.18）,（64.19 ± 10.45） μg/g respectively,the difference was statistically significant （P 〈 0.05）.TGF-β1,PGE-2 and HYP mRNA expression of soft tissue in model group were 5.78 ± 0.90,8.29 ± 1.76,13.89 ±3.18 respectively,significantly higher than the control group （1.89 ±0.27,3.06 ± 0.60,7.22 ± 2.05）,the difference was statistically significant （P 〈 0.05）.Conclusion Type 2 diabetes can result in inflammatory changes and fibrosis of rat shoulder cartilage,synovial membrane,surrounding muscles and other soft tissues.The above pathological features are consistent with the natural degeneration of shoulder soft tissue and periarthritis.Therefore,type 2 diabetes can be considered as one of the causes of periarthritis.