长链非编码RNA MEF2C-AS1对大鼠骨量的影响

The Effect of Long Non-coding RNA MEF2C-AS1 on Bone Mass in Rats

目的探讨长链非编码RNA MEF2C-AS1是否通过下调去卵巢大鼠MEF2C和SOST表达,来影响大鼠骨量。方法将46只5月龄SD大鼠,随机分为假手术组(SHAM组)和去卵巢组(OVX组),每组各23只。术后12周,各组随机剖杀大鼠以验证骨质疏松模型是否成功。将假手术组剩下的16只大鼠随机分成2组,每组各8只,分别为假手术对照组(SHAM)、假手术+MEF2C-AS1组(SHAM+MEF2C-AS1);将去卵巢组剩下的16只大鼠随机分成2组,每组各8只,分别为去卵巢对照组(OVX)、去卵巢+MEF2C-AS1组(OVX+MEF2C-AS1)。然后对SHAM+MEF2C-AS1组和OVX+MEF2C-AS1组注射MEF2C-AS1慢病毒载体,对SHAM组和OVX组注射等量空慢病毒载体。8周后处死大鼠时收集大鼠股骨和血液行Western blot、ELISA分析和Micro-CT成像。结果术后12周,OVX组骨体积(bone volume,BV)、骨体积分数(bone volume fraction/total volume,BV/TV)、骨小梁数量(trabecular number,Tb.N)、骨小梁厚度(trabecular thickness,Tb.Th)、骨密度(bone mineral density,BMD)较SHAM组下降(P<0.05),而骨小梁分离度(Tb.Sp)较SHAM组升高(P<0.05),证实大鼠骨质疏松模型造模成功。慢病毒载体注射8周后,OVX+MEF2C-AS1组大鼠MEF2C蛋白和SOST蛋白相对表达量较OVX对照组下降(P<0.05),且OVX+MEF2C-AS1组大鼠骨体积(BV)、骨体积分数(BV/TV)、骨小梁数量(Tb.N)、骨小梁厚度(Tb.Th)及骨密度(BMD)均高于OVX对照组(P<0.05)。结论lncRNA MEF2C-AS1通过下调MEF2C表达,来抑制SOST蛋白表达量,改善去卵巢骨质疏松大鼠骨小梁相关骨微结构,促进骨形成,增加骨体积和骨密度,对骨质疏松有潜在的治疗意义。

Objective To investigate whether long non-coding RNA MEF2C-AS1 can affect the bone mass by down-regulating the MEF2C and SOST expression in ovariectomized rats.Methods Forty-six five-month-old SD rats were randomly divided into the sham operation(SHAM)group and the ovariectomized(OVX)group,with twenty-three rats in each group.At 12 weeks after the operation,rats in each group were randomly dissected to verify the success of the osteoporosis model.The remaining rats were randomly divided into the SHAM control group,SHAM+MEF2C-AS1 group,OVX control group and OVX+MEF2C-AS1 group,with 8 rats in each group.Then the corresponding lentivirus vector of MEF2C-AS1 were injected into the+MEF2C-AS1 groups and an equivalent empty lentivirus vector were injected into the control groups.After 8 weeks,when the rats were executed,the femurs and blood were collected for Western blot,ELISA analysis and Micro-CT imaging.Results At 12 weeks after the operation,BV,BV/TV,Tb.Th,Tb.N and BMD in OVX group were lower than SHAM group(all P<0.05),while Tb.Sp was significantly higher than that of the SHAM group(P<0.05),which confirming that the rat osteoporosis model was successfully established.After 8 weeks of lentivirus vector injection,the relative expression levels of MEF2C protein and SOST protein in OVX+MEF2C-AS1 group were lower than OVX control group(P<0.05).The BV,BV/TV,Tb.N,Tb.Th and BMD of rats in OVX+MEF2C-AS1 group were higher than OVX control group(P<0.05).Conclusion lncRNA MEF2C-AS1 can improve the trabecular bone microstructure,promote bone formation and increase bone volume and bone mineral density in rats with osteoporosis after ovariectomization,by inhibiting the expression of sclerostin through down-regulating MEF2C protein expression,which has potential therapeutic significance for osteoporosis.