高脂饮食对去卵巢大鼠骨微结构、骨IL-6及M-CSF mRNA水平的影响

Effects of high-fat diet on bone microstructure,bone IL-6 and M-CSF mRNA levels in ovariectomized rats

目的观察高脂饮食对绝经后雌性SD(sprague-dawiey)大鼠骨微结构、骨组织白介素-6(IL-6)及巨噬细胞集落刺激因子(M-CSF)m RNA的影响,探讨高脂对骨微结构的影响及其可能的发病机制。方法将40只6月龄雌性SD大鼠随机分为假手术+普通饲料饲养组(SHAM组)、假手术+高脂饲料饲养组(HFD组)、去卵巢+普通饲料组(OVX组)、去卵巢+高脂饲料饲养组(OVX+HFD组),每组10只。6个月后用微计算机断层扫描(Micro-CT)等方法检测大鼠右侧胫骨的骨微结构。用实时荧光定量聚合酶链反应(Realtime RT-PCR)测量大鼠左侧股骨中IL-6和M-CSF m RNA的表达差异。结果 6个月后,OVX组的骨体积(BV/TV)、骨小梁数目(Tb.N)、骨小梁厚度(Tb.Th)低于SHAM组,骨小梁分离度(Tb.Sp)大于SHAM组(P<0.05);OVX组BV/TV、Tb.N均大于OVX+HFD组,Tb.Sp小于OVX+HFD组(P<0.05);SHAM组BV/TV、Tb.N、Tb.Th高于SHAM+HFD组,SHAM+HFD与OVX组相比,除Tb.N外,其BV/TV、Tb.Th及Tb.Sp均无明显差异(P>0.05)。OVX组M-CSF和IL-6 m RNA的表达均高于SHAM组(P<0.05)。SHAM的M-CSF和IL-6 m RNA的表达低于SHAM+HFD组(P<0.05),SHAM+HFD的MCSF和IL-6 m RNA的表达低于OVX组(P<0.05),但OVX组与OVX+HFD组比较,M-CSF和IL-6 m RNA的表达无显著差异(P>0.05)。结论高脂引起的骨微结构的改变有可能是通过提高IL-6、M-CSF m RNA水平,导致破骨细胞活性增强、骨吸收增加引起的。

Objective To observe the effects of high-fat diet on bone microstructure,bone interleukin-6(IL-6)and macrophage colony-stimulating factor(M-CSF)mRNA in postmenopausal female SD rats(Sprague-Dawiey),and to explore the impact of high fat on bone microstructure and its potential pathogenesis.Methods A total of40female SD rats with6months old were randomly divided into sham operation+normal feed group(SHAM group),sham operation+high-fat feed group(HFD group),ovariectomized+normal feed group(OVX group)and ovariectomized+high-fat feed group(OVX+HFD group),with10rats in each group.After6months,microcomputer tomography(Micro-CT)and other methods were used to detect the bone microstructure of the right tibia.Real-time PT-PCR was used to measure the expression difference of IL-6and M-CSF mRNA in the left femur of the rats.Results After6months,the bone volume(BV/TV),the number of trabecular bone(Tb.N)and trabecular bone thickness(Tb.Th)in the OVX group were significantly lower than those in SHAM group,while the separation of trabecular bone(Tb.Sp)was higher than that in SHAM group(P<0.05);BV/TV,Tb.N in OVX group were higher than those in OVX+HFD group,and Tb.Sp was lower than that in OVX+HFD(P<0.05);BV/TV,Tb.N,Tb.Th in SHAM group were all higher than those in SHAM+HFD group.Compared with OVX group,other than Tb.N,BV/TV,Tb.Th and Tb.Sp in SHAM+HFD group were not significantly different(P>0.05).The expression of M-CSF and IL-6mRNA in OVX group was higher than that in SHAM group(P<0.05).The expression of M-CSF and IL-6mRNA in SHAM group was lower than that in SHAM+HFD group(P<0.05).The expression of M-CSF and IL-6mRNA in SHAM+HFD group was lower than that in OVX group(P<0.05).However,there was no significant difference in the expression of M-CSF and IL-6mRNA between OVX group and OVX+HFD group(P>0.05).Conclusion Changes in bone microstructure induced by high fat may be caused by increased IL-6and M-CSF mRNA levels,resulting in enhanced osteoclast activity and increased bone resorption.