大鼠创伤性骨髓炎后骨骼肌过度纤维化及其与转化生长因子-β的相关性

Excessive skeletal muscle fibrosis and its correlation of tumor growth factor-IS in rats with traumatic osteomyelitis

目的探讨创伤性骨髓炎后骨骼肌过度纤维化及其与转化生长因子β（TGF—β）的相关性。方法雄性Wistar大鼠80只，按随机数字表法分为骨髓炎组和对照组，每组40只。骨髓炎组通过创伤（软组织钝挫伤）、手术（髓内克氏针固定）、感染（接种10^2CFU／ml金黄色葡萄球菌菌液）建立创伤性骨髓炎模型。对照组以无菌等渗盐水替代菌液。术后3，7，14，28d取损伤周围肌肉组织，采用HE染色和免疫组化染色观察不同时相点病理学变化及转化生长因子-β（TGF—β）的表达情况。结果骨骼肌HE染色：骨髓炎组各时相点可见炎症、坏死、纤维组织增生等变化，而对照组病变较轻。骨骼肌免疫组化染色：骨髓炎组、对照组染色结果均为阳性，骨髓炎组肌细胞和间质阳性染色均较强，对照组阳性染色主要表达在肌细胞中。术后3d骨髓炎组TGF-β表达强度（19．4±2．7）与对照组（18．6±2．8）比较，差异无统计学意义（P〉0．05）；术后7，14，28d，骨髓炎组（25．3±1．9，28．5±2．7，36．0±1．8）与对照组（21．7±2．5，25．6±1．8，34．2±1．6）相应时相点比较，差异有统计学意义（P〈0．05）。术后骨髓炎组、对照组TGF-β表达逐步增强，表达强度均在术后28d达到峰值。结论大鼠创伤性骨髓炎致骨骼肌纤维化增加，且其纤维化程度与TGF-β表达增加相关。

Objective To examine excessive fibrosis of the skeletal muscle in rats with traumatic osteomyelitis and its correlation with tumor growth factor-β （TGF-β）. Methods Eighty male Wistar rats were randomized into osteomyelitis group （ n = 40 ） and control group （ n = 40 ）, according to the random number table. Rats in osteomyelitis group were subjected to soft tissue injury, intramedullary Kirschner wire fixation and bacterial infection with 102 CFU/ml Staphylococcus aureus. In control group, aseptic normal saline was used instead of bacteria solution. At postoperative 3,7, 14 and 28 d, muscular tissues surrounding the injury site were harvested to detect histopathologic changes and expression of TGF- β by HE staining and immunohistoehemistry. Results HE staining showed more severe pathological changes in osteomyelitis group than in control group, such as inflammation, necrosis and fibroplasia. Positive immunohistochemical staining was detected, but a strong positive staining was recognized within both myocyte and matrix in osteomyelitis group versus only myocytc in control group. At postoperative 3 d, expression of TGF-β was similar between osteomyelitis group （ 19.4 ± 2.7 ） and control group （18.6 ± 2.8） （P 〉 0.05） . At postoperative 7, 14 and 28 d, expressions of TGF-β in osteomyelitisgroup were 25.3 ± 1.9, 28.5 ± 2.7 and 36.0 ± 1.8 respectively, higher than 21.7 ± 2.5, 25.6 ± 1.8 and 34.2 ± 1.6 in control group （ P 〈 0.05 ）. After operation, expressions of TGF-β in both groups showed gradual increase and peaked at 28 d. Conclusion Traumatic osteomyelitis can increase skeletal muscle fibrosis and the process is related to the increased expression of TGF-β.