CAJ | 학술논문

在糖尿病性大血管病变的发病过程中,高血糖以及晚期糖基化终末产物(advanced glycation end products,AGEs)、脂质异常和高胰岛素血症的相互作用较其单独作用可能更重要.本研究采用糖基化白蛋白(glycated serum albumin,GSA)模拟AGEs,观察胰岛素和GSA对大鼠血管平滑肌细胞(vascular smooth muscle cells,VSMCs)的增殖是否存在协同作用,并初步探讨其作用机制.采用组织贴块法分离培养大鼠VSMCs.经过或不经过各种丝裂原激活蛋白激酶(mitogen-activated protein kinases,MAPKs)抑制剂和氧自由基清除剂N-acetylcysteine(NAC)处理后,加入不同浓度的胰岛素、GSA或GSA+胰岛素,用MTT法和细胞计数法检测VSMCs的增殖.采用Western blot检测p38 MAPK和C-Jun N-terminal kinase 1/2(JNK1/2)的磷酸化.结果显示,GSA和胰岛素联合作用促进p38 MAPK的磷酸化,而对JNK1/2的磷酸化无明显影响.GSA和胰岛素均可促进VSMCs增殖,而且两者具有协同作用.p38 MAPK抑制剂SB203580和NAC可以抑制GSA和胰岛素联合作用引起的VSMCs增殖.以上结果提示,胰岛素和GSA对促进VSMCs增殖有协同作用,这可能是通过氧化应激敏感的p38 MAPK通路实现的.胰岛素和AGEs的协同作用在糖尿病性动脉粥样硬化和再狭窄的发病过程中可能起重要作用.
재당뇨병성대혈관병변적발병과정중,고혈당이급만기당기화종말산물(advanced glycation end products,AGEs)、지질이상화고이도소혈증적상호작용교기단독작용가능경중요.본연구채용당기화백단백(glycated serum albumin,GSA)모의AGEs,관찰이도소화GSA대대서혈관평활기세포(vascular smooth muscle cells,VSMCs)적증식시부존재협동작용,병초보탐토기작용궤제.채용조직첩괴법분리배양대서VSMCs.경과혹불경과각충사렬원격활단백격매(mitogen-activated protein kinases,MAPKs)억제제화양자유기청제제N-acetylcysteine(NAC)처리후,가입불동농도적이도소、GSA혹GSA+이도소,용MTT법화세포계수법검측VSMCs적증식.채용Western blot검측p38 MAPK화C-Jun N-terminal kinase 1/2(JNK1/2)적린산화.결과현시,GSA화이도소연합작용촉진p38 MAPK적린산화,이대JNK1/2적린산화무명현영향.GSA화이도소균가촉진VSMCs증식,이차량자구유협동작용.p38 MAPK억제제SB203580화NAC가이억제GSA화이도소연합작용인기적VSMCs증식.이상결과제시,이도소화GSA대촉진VSMCs증식유협동작용,저가능시통과양화응격민감적p38 MAPK통로실현적.이도소화AGEs적협동작용재당뇨병성동맥죽양경화화재협착적발병과정중가능기중요작용.
Hyperglycemia, advanced glycation end products (AGEs), hyperinsulinemia and dyslipidemia may play roles in the development of diabetes-associated atherosclerosis and post-angioplasty restenosis. Clinically, their effects seem to be synergic.However, few studies have focused on the synergistic action of these factors. In the present study, we investigated wheth er glycated serum albumin (GSA) has a synergistic effect with insulin on the proliferation of vascular smooth muscle cells (VSMCs). VSMCs were isolated from rat thoracic aortas and cultured in fetal bovine serum (FBS)-free medium for 24 h, then exposed to GSA, insulin or GSA + insulin for 48 h with or without pretreatment of mitogen-activated protein kinase (MAPK) inhibitors or the antioxidant N-acetylcysteine (NAC). Cell growth rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay or cell counting. The changes of phosphorylated-p38 MAPK and phosphorylated-C-Jun N-terminal kinase 1/2 (JNK1/2) were measured by Western blot analysis. The results showed that only p38 MAPK, but not JNK was activated by GSA and insulin co-incubation. VSMC proliferation was increased by insulin (10-1000 nmol/L) or GSA (10, 100 μg/mL). Co-incubation of insulin (100 nmol/L) and GSA (100 μg/mL) caused a more potent increase in VSMC proliferation than insulin or GSA incubation alone. P38 MAPK inhibitor, SB203580,as well as NAC, could inhibit the VSMC proliferation induced by co-incubation of GSA and insulin. The results show that insulin enhances GSA-induced VSMC proliferation, which may be mediated through a reactive oxygen species (ROS)-p38 MAPK pathway.The synergism of AGEs and insulin may play a detrimental role in the pathogenesis of diabetic atherosclerosis and post-angioplasty restenosis.