阿仑膦酸钠及仙灵骨葆对OPG基因敲除小鼠骨骼肌的影响

Effect of alendronate and Xianlinggubao on skeletal muscle of osteoprotegerin gene knockout osteoporotic mice

目的:选用骨保护素(osteoprotegerin,OPG)基因敲除的骨质疏松小鼠模型,观察阿仑膦酸钠及仙灵骨葆对其骨骼肌的作用。方法:将2个月龄的OPG基因敲除小鼠及正常小鼠随机分为安慰剂(正常组)、阿仑膦酸钠及仙灵骨葆组,予安慰剂或药物处理12周。股直肌行HE染色后观察其形态,并采用实时PCR检测股直肌重链肌球蛋白mRNA的表达情况。结果:OPG基因敲除小鼠的股直肌单位面积骨骼肌纤维数目明显增加(+12.94%,P=0.028),肌纤维横截面积明显减小(-23.0%,P=0.004),股直肌中肌球蛋白重链mRNA的表达水平显著降低(P<0.01);而阿仑膦酸钠及仙灵骨葆处理后能明显减少单位面积骨骼肌纤维数目(-14.64%,P=0.022;-9.96%,P=0.014),增加骨骼肌纤维横截面积(+24.45%,P=0.011;+23.3%,P=0.002),同时能够增加小鼠股直肌肌球蛋白重链mRNA的表达水平(P<0.01)。结论:阿仑膦酸钠及仙灵骨葆能明显改善OPG基因敲除所致骨质疏松小鼠骨骼肌的退化,其作用机制可能与改善骨密度或中药的植物雌激素作用有关。

Objective To investigate the effect of alendronate （ALEN） and Xianlinggubao（XLGB） on skeletal muscle of osteoprotegerin （OPG） gene knockout mice. Methods 2-month-old wild type mice （WT） and OPG gene knockout mice （KO） were randomly divided into WT＋NS （normal saline）, KO＋NS, KO＋ALEN and KO＋XLGB groups. Animals in KO＋ALEN and KO＋XLGB were treated with ALEN [injected subcutaneously, 0.2 mg/（kg·d）] and XLGB [injected intragastrically, 500 mg/（kg·d）] for 12 weeks, respectively. Histological morphology of rectus femoris was examined by HE staining, and mRNA of myosin heavy chain （Myh） of rectus femoris was determined by real-time PCR. Results OPG gene knockout mice had significant skeletal muscle degeneration manifested as increase in number of skeletal muscle fiber/unit area （＋12.94% ,P=0.028）and reduction of cross-sectional area of skeletal muscle fiber （-23.0% ,P=0.004）, combined with significant decrease in mRNA expression of Myh （P〈0.01）. Both treatments of alendronate and XLGB could reduce the the number of skeletal muscle fiber/ unit area （-14.64%,P=0.022;-9.96%,P=0.014, respectively）, increase the cross-sectional area of fiber （＋24.45%,P= 0.011; ＋23.3% ,P=0.002）, and increase the mRNA expression of Myh of rectus femoris （P〈0.01）. Conclusions Both alendrouate and XLGB could prevent the deterioration of skeletal muscle of osteoporotic mice induced by OPG gene knockout.