内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

大鼠和小鼠胰岛细胞和MIN6细胞均有内脂素表达.胰岛细胞内脂素的表达受葡萄糖(5.5和33.3 mmol/L)和棕榈酸(0.5 mmol/L)的影响(1.0±0.11、1.32±0.18、1.33±0.15、1.72±0.27,与5.5mmol/L葡萄糖组相比,均P<0.05),提示内脂素可能参与胰岛细胞的胰岛素释放的调控.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

内脂素在MIN6胰岛β细胞的表达及葡萄糖和棕榈酸对其表达的影响

Visfatin was expressed in rat anti mouse islets,as well as in MIN6 cells. The visfatin expression was affected by various concentrations of environmental glucose (5.5 and 33.3 mmoL/L) and palmitate(0.5 mmol/L). As compared with low-level glucose medium (5.5 mmol/L, 1.0±0.11) , visfatin expression increased in media with high glucose and palmitate (1.32 ±0. 18, 1. 33±0. 15,1.72±0.27, all P<0. 05). The result suggests that visfatin seems to be involved in the regulation of insulin secretion.     

高糖毒性对胰岛β细胞的影响及其临床对策

1血糖主要指血浆葡萄糖而言,是机体最主要的供能物质,摄入的饮食,在多种酶的作用下,逐步转化为以葡萄糖为代表的单糖或双糖。正常人血糖的浓度在神经、内分泌和肝脏等的调节下维持在一个狭窄的生理范围内,一般空腹血糖保持在3.9~5.6mmol/L,餐后血糖不超过7.8~8.3mmol/L水平,尽管由于饮食的差异,使血糖水平也高低波动很大,但胰岛β细胞对血糖的微小变化,可产生非常常敏感的应答反应。使正常人的血糖得以维持在狭窄的生理范围,表达B细胞及胰岛素的分泌功能处于良好状态。     

胰岛β细胞游离脂肪酸受体1表达对胰岛素分泌的影响

目的研究高脂、罗格列酮和非诺贝特对体外培养的β细胞瘤细胞系NIT-1细胞游离脂肪酸受体1（FFAR1）mRNA表达和胰岛素分泌功能的影响。方法将NIT-1细胞随机分为正常组（NC组）、高脂组（PA组）、高脂加罗格列酮组（RG组）、高脂加非诺贝特组（FF组）体外培养48 h,用放免法检测细胞基础胰岛素分泌（BIS）及葡萄糖刺激的胰岛素分泌（GSIS）水平,酶法检测胞内甘油三酯（TG）含量,RT-PCR技术检测细胞内FFAR1 mR-NA水平。结果与NC组比较,PA组GSIS降低,细胞内TG含量增多,FFAR1 mRNA表达明显上调。与PA组比较,RG、FF组GSIS增强,细胞内TG含量减少;RG组FFAR1 mRNA表达与之接近,FF组则明显减少,接近NC组水平。结论高脂对β细胞的毒性作用部分是通过上调FFAR1 mRNA表达所致;非诺贝特可通过抑制这种作用保护β细胞功能;罗格列酮对β细胞功能的保护作用与之无关。     

高饱和脂肪酸和高糖饮食对大鼠肝脏过氧化物酶体脂肪酸β-氧化的影响

将30只雄性Wistar大鼠分为三组各10只，对照组（NC组）基础饮食饲养，高饱和脂肪酸组（HSF组）高饱和脂肪酸饲养，高糖组（HS组）高糖饲养。喂养24周后，观察三组体重（BW），血清总胆固醇（TC）、甘油三酯（TG）、游离脂肪酸（FFA），肝脏过氧化氢酶（CAT）、脂酰CoA氧化酶、过氧化物酶体脂肪酸β-氧化活性变化。结果 HSF组、HS组BW、TG、TC、FFA及肝脏过氧化氢酶、过氧化物酶体脂肪酸β-氧化、脂酰CoA氧化酶活性较NC组明显升高（P〈0．05或P〈0．01）。提示长期高饱和脂肪酸、高糖饮食可导致大鼠脂质代谢紊乱，肝脏中的CAT、脂酰CoA氧化酶和过氧化物酶体脂肪酸β-氧化的活性升高。     

脂毒性对胰岛β细胞的影响及其临床对策

2型糖尿病（T2DM）是最常见的糖尿病类型,占所有糖尿病患者的90%以上。β细胞功能衰竭所致的胰岛素分泌缺陷是T2DM的主要特征之一。β细胞功能衰竭的根本原因至今未能完全阐明。目前大部分的研究一致认为,高血糖和脂质代谢紊乱是导致β细胞功能衰竭的主要原因,即所谓的糖毒性和脂毒性。其中脂质代谢紊乱主要表现为高甘油三脂血症,低密度脂蛋白胆固醇升高及高密度脂蛋白胆固醇降低。     

棕榈酸对小鼠胰岛β细胞瘤MIN6细胞凋亡的影响及其机制探讨

目的观察棕榈酸对小鼠胰岛β细胞瘤MIN6细胞凋亡的影响,并探讨其作用机制。方法培养于含0.5 mM棕榈酸的培养基中的MIN6细胞为实验组,仅含5%BSA的培养基培养的MIN6细胞为对照组,采用流式细胞术和原位末端转移酶标记技术(TUNEL)检测两组MIN6细胞凋亡情况。实验组于培养12(实验1组)、24(实验2组)、36(实验3组)h后,对照组于培养36 h后,采用Western blot法检测MIN6细胞中的凋亡诱导因子(AIF)及survivin。构建survivin过表达载体并转染实验组细胞,36 h后,同前法检测转染及未转染survivin过表达载体的MIN6细胞在含棕榈酸培养基中的凋亡情况。结果培养36 h后实验组MIN6细胞凋亡率为30.27%±3.15%,明显高于对照组的4.61%±0.51%(P<0.01)。实验1、2、3组MIN6细胞核中的AIF的相对表达量高于对照组,sur-vivin相对表达量低于对照组(P均<0.05)。棕榈酸培养36 h后,转染survivin过表达载体的MIN6细胞凋亡率为11.6%±2.09%,低于未转染者的31.27%±2.97%(P<0.01)。结论棕榈酸可诱导小鼠胰岛β细胞瘤MIN6细胞凋亡,可能与下调survivin表达和激活AIF凋亡信号通路有关;survivin表达上调可抑制棕榈酸诱导的MIN6细胞凋亡。     

高糖对原代培养人系膜细胞表达TGF-β1的影响

目的了解高糖对原代培养的人肾小球系膜细胞表达TGF-β1的影响,并进一步探讨糖尿病肾病的发病机制。方法取自愿水囊引产的胎儿肾并解剖取肾皮质剪碎,应用肾皮质组织块法合优生选择法培养人肾小球系膜细胞。以ELISA方法检测TGF-β1的表达。结果与正常组相比较,高糖组TGF-β1在24、48、72h均显著升高(P0.05或P0.01)。结论高糖能够升高系膜细胞TGF-β1分泌,这可能与肾小球系膜细胞细胞外基质积聚和糖尿病肾病发病密切相关。     

高糖、高脂肪酸饮食对大鼠骨骼肌葡萄糖转运体4mRNA表达的影响

成年Wistar大鼠随机分为对照组、高糖组、高饱和脂肪酸组、高不饱和脂肪酸组，喂养24周后，各实验组与对照组相比葡萄糖输注率（GIR）明显减低（P〈0．01），大鼠骨骼肌葡萄糖转运体4（GluT4）mRNA的表达显著降低（P〈0．01），其表达与游离脂肪酸呈明显负相关，与GIR呈明显正相关。高糖、高饱和脂肪酸及高不饱和脂肪酸饮食均可造成大鼠骨骼肌GluT4 mRNA的表达降低，这可能是胰岛素抵抗的原因。     

波动性高糖对胰岛β细胞增殖及Skp2-p27表达的影响

目的 探讨波动性高糖对INS-1细胞增殖、凋亡及对细胞周期进程的影响,并研究其可能的分子机制.方法 采用细胞计数试剂盒(cell counting kit-8)检测细胞增殖活性,流式细胞仪测定细胞周期及细胞ROS水平,Annexin-V/PI双标流式细胞术检测细胞凋亡.应用Western印迹检测细胞周期调控蛋白p27及Skp2的表达水平.结果 (1)波动性高糖及持续性高糖均明显抑制INS-1细胞的生长,且波动性高糖对细胞增殖的抑制作用更为显著.(2)波动性高糖及持续性高糖均明显增加INS-1细胞的凋亡,且波动性高糖作用更为显著.(3)波动性高糖及持续性高糖能明显抑制细胞周期进程,使INS-1细胞周期更多滞留在G0/G1期,G2/M期与S期细胞比例下降,波动性高糖作用更显著.(4)波动性高糖及持续性高糖均能显著增强细胞周期调控蛋白p27的表达,同时减弱Skp2蛋白的表达水平.结论 波动性高糖较持续性高糖更能够抑制INS-1细胞的增殖和诱导凋亡,可能是通过减弱Skp2蛋白的表达水平,增加p27蛋白的活性,使细胞阻滞在G0/G1期,抑制细胞周期进程,从而减弱细胞的增殖活性.

Abstract：

Objective To investigate the effect of intermittent high glucose on proliferation, apoptosis, and cell cycle progression of INS-1 cells, and the possible intracellular pathways activated by intermittent high glucose. Methods Cell viability was evaluated by cell counting kit, the cell cycle was determined by flow cytometry,Annexin-V/PI double-labeled cell apoptosis detection kit was used to monitor cell apoptosis. Cell cycle related protein Skp2 and p27 expressions were detected by Western blot. Results ( 1 ) Both intermittent and constant high glucose significantly inhibited the growth of INS-1 cells, and the former effect was more significant. ( 2 ) Intermittent and constant high glucose levels significantly increased apoptosis in INS-1 cells, and the former effect was more significant. (3) Intermittent and constant high glucose levels significantly inhibited the cell process, the G0/G1 cell cycle arrest also was induced by intermittent high glucose, resulting in lowered proportion of the G2/M phase and S phase of INS-1 cells. (4) Intermittent and constant high glucose significantly decreased the level of protein Skp2 and increased the level of cell cycle related protein p27. Conclusion Intermittent high glucose levels affect INS-1 cell growth and proliferation, as well as induce cell apoptosis, probably by decreasing the level of protein Skp2 and increasing the level of p27 in the cells, resulting in arrest of progression through the G1 phase to the S phase of INS1 cells, and thus impairment of cell proliferation.     

游离脂肪酸对胰岛素瘤细胞系βTc6细胞葡萄糖激酶和葡萄糖转运蛋白2表达及胰岛素分泌功能的影响

目的 探讨游离脂肪酸（FFA）对小鼠胰岛素瘤细胞系βTc6细胞葡萄糖激酶（GK）和葡萄糖转运蛋白2（GLUT2）的表达及相应的胰岛素分泌功能变化的影响.方法用不同浓度FFA（0.25、0.50、1.00 mmol/L）干预βTc6细胞24 h,应用逆转录（RT）-PCR法和Western Blot法检测GK和GLUT2表达情况,并观察细胞形态及葡萄糖刺激的胰岛素分泌功能（GSIS）的变化.应用单因素方差分析进行统计学分析.结果 （1）经过0.25 mmol/L FFA 作用24 h后,未见细胞形态学及GSIS 明显变化,细胞内GK和GLUT2 mRNA及其蛋白的表达水平与空白对照组（GK对照组0.80±0.12,GLUT2对照组0.72±0.11）比较亦未发生明显改变（均P〉0.05）;（2）0.50～1.00 mmol/L FFA 作用24 h之后,βTc6细胞内可见脂滴积聚,细胞团有崩解的趋势,随着浓度的增大,上述现象愈加明显.细胞GK（GKFFA0.500.32±0.05,GKFFA1.000.24±0.03）和GLUT2 （GLUT2FFA0.500.28±0.04,GLUT2FFA1.000.21±0.03）mRNA表达逐渐减低（均P〈0.05）,相应的蛋白表达水平亦逐步降低,胰岛素分泌也逐渐减少（均P〈0.05）.结论 低浓度FFA对胰岛β细胞生存和GK、GLUT2表达以及GSIS没有明显影响,但较高浓度的FFA将损害β细胞,并抑制GK和GLUT2表达以及GSIS.