CAJ | 학술논문

目的：利用小鼠的 MC3T3-E1细胞来观察地塞米松对成骨细胞局部肾素-血管紧张素系统的调节作用。方法常规培养 MC3T3-E1细胞，细胞免疫组织化学观察成骨细胞局部肾素-血管紧张素系统组分血管紧张素Ⅱ的Ⅰ型和Ⅱ型受体以及血管紧张素转化酶的表达。然后利用无血清培养基培养12 h后，将 MC3T3-E1细胞分为4组：对照组、地塞米松组(10-6 mol/L)、地塞米松+米非司酮组以及米非司酮组(10-5 mol/L)。待干预36 h后，检测血管紧张素转化酶的活性。利用半定量PCR检测血管紧张素Ⅱ的Ⅰ型和Ⅱ型受体以及血管紧张素转化酶的mRNA的表达水平。利用 Western blot方法检测血管紧张素Ⅱ的Ⅰ型和Ⅱ型受体以及血管紧张素转化酶的蛋白表达水平。结果与对照组比较，地塞米松明显增加了成骨细胞的血管紧张素转化酶的活性、同时也增加了血管紧张素Ⅱ的Ⅰ型和Ⅱ型受体以及血管紧张素转化酶的蛋白和mRNA的水平(P<0.05)，但当同时给予米非司酮时，地塞米松的这种作用被阻断(P<0.05)。当单独给予米非司酮时，成骨细胞上血管紧张素转化酶的活性、血管紧张素Ⅱ的Ⅰ型和Ⅱ型受体以及血管紧张素转化酶的蛋白和mRNA的水平与对照组比较均无发生明显变化(P>0.05)。结论地塞米松通过成骨细胞上的糖皮质素受体激活成骨细胞局部肾素-血管紧张素系统，这很可能是激素性骨质疏松的发病机制之一。
목적：이용소서적 MC3T3-E1세포래관찰지새미송대성골세포국부신소-혈관긴장소계통적조절작용。방법상규배양 MC3T3-E1세포，세포면역조직화학관찰성골세포국부신소-혈관긴장소계통조분혈관긴장소Ⅱ적Ⅰ형화Ⅱ형수체이급혈관긴장소전화매적표체。연후이용무혈청배양기배양12 h후，장 MC3T3-E1세포분위4조：대조조、지새미송조(10-6 mol/L)、지새미송+미비사동조이급미비사동조(10-5 mol/L)。대간예36 h후，검측혈관긴장소전화매적활성。이용반정량PCR검측혈관긴장소Ⅱ적Ⅰ형화Ⅱ형수체이급혈관긴장소전화매적mRNA적표체수평。이용 Western blot방법검측혈관긴장소Ⅱ적Ⅰ형화Ⅱ형수체이급혈관긴장소전화매적단백표체수평。결과여대조조비교，지새미송명현증가료성골세포적혈관긴장소전화매적활성、동시야증가료혈관긴장소Ⅱ적Ⅰ형화Ⅱ형수체이급혈관긴장소전화매적단백화mRNA적수평(P<0.05)，단당동시급여미비사동시，지새미송적저충작용피조단(P<0.05)。당단독급여미비사동시，성골세포상혈관긴장소전화매적활성、혈관긴장소Ⅱ적Ⅰ형화Ⅱ형수체이급혈관긴장소전화매적단백화mRNA적수평여대조조비교균무발생명현변화(P>0.05)。결론지새미송통과성골세포상적당피질소수체격활성골세포국부신소-혈관긴장소계통，저흔가능시격소성골질소송적발병궤제지일。
Objective To investigate the regulatory effects of glucocorticoids on the local renin-angiotensin system in osteoblasts by using MC3T3-E1 cells.Methods Cellular immune histochemistry was carried out to observe the renin-angiotensin system in osteoblasts.And then after 12-hour culture in serum-free solution,MC3T3-E1 cells were divided into four groups:control,dexamethasone (DXM),dexamethasone + mifepristone (DXM+MIF)and mifepristone (MIF).Components of the renin-angiotensin system including angiotensin type 1 receptor (AT1R),angiotensin type 2 receptor (AT2R)and angiotensin converting enzyme (ACE)in osteoblasts were detected at the mRNA and protein levels using Western blot and PCR.The activity of ACE was also measured after 36-hour intervention.Results The results of immunohistochemistry showed that AT1R,AT2R and ACE were all expressed in osteoblasts.The activity of ACE increased obviously after dexamethasone intervention compared with that in the control group,which was blocked by mifepristone.The mRNA levels of AT1R,AT2R and ACE were increased by dexamethasone compared with those in the control group,which was inhibited by mifepristone.The protein levels of AT1R,AT2R and ACE were enhanced by dexamethasone compared with those in the control group, which was blocked when the cells were co-intervened with mifepristone.However,ACE activity and the mRNA and protein levels of AT1R,AT2R and ACE did not change when the cells were intervened with mifepristone alone (P>0.05).Conclusion The local renin-angiotensin system in osteoblasts is activated by dexamethasone through glucocorticoid receptors on osteoblasts,which may be one of the pathogenesis of glucocorticoid-induced osteoporosis.