AMPK调节骨骼肌细胞GLUT4基因表达的机制研究

腺苷酸活化蛋白激酶(AMPK)能调节运动/肌肉收缩所引起的骨骼肌细胞葡萄糖转运蛋白4(GLUT4)基因的表达,但至今它的调节机制不清.研究显示在非运动刺激引起的细胞信号事件中由组蛋白去乙酰化酶(HDACs)以及组蛋白乙酰化酶(HATs)控制的组蛋白乙酰化状态是调节基因表达的重要机制,所以我们假设AMPK信号途径是通过征用HDACs中的HDAC5(在骨骼肌细胞内高表达)来实现对运动/肌肉收缩引起的GLUT4基因表达控制.细胞分为正常浓度葡萄糖对照组(NGLU组)、正常浓度AICAR组(NGLU AICAR组)、高浓度对照组(HGLU组)、高浓度AICAR组(HGLU AICAR组).用5 mmol/L和20 mmol/L葡萄糖浓度培养骨骼肌细胞后,NGLU AICAR组和HGLU AICAR组与肌肉收缩模拟信号刺激5-氨基-4-甲酰胺咪唑核糖核苷酸(AICAR)孵育.AICAR能激活NGLU组骨骼肌细胞AMPKα2、减少骨骼肌细胞核HDAC5蛋白、促使HDAC5与骨骼肌细胞加强因子(MEF2)蛋白分离和上调GLUT4基因的表达;相反,高浓度葡萄糖延迟由AICAR引起的AMPKα2磷酸化、AMPKα2向细胞核转入、HDAC5向细胞核转出和GLUT4基因的表达.实验结果说明在不同葡萄糖浓度下的骨骼肌细胞GLUT4基因表达变化都对应着上游AMPK蛋白和下游HDAC5蛋白的变化,AMPK可能是征用转录抑制子HDAC5来调节MEF2的活性而达到控制肌肉收缩所引起的GLUT4基因表达.     

骨质疏松——一种起源于人生最初二十年的疾病

骨质疏松──一种起源于人生最初二十年的疾病ＥｇｏＳｅｅｍａｎ段云波１．前言由于骨密度随年龄增加而降低，因此骨折患者骨折部位的低骨密度可能是由于大量的骨丢失或因年轻时获得的骨峰值水平较低所致［１～５］，这两种过程发生机制有着本质的区别，骨折发生的年龄，...     

血管加压素受体Ⅰ在实验性糖尿病大鼠肾脏和肝脏的调节

本文利用链脲佐菌素诱导的实验性糖尿病大鼠,在糖尿病形成2周时分别测定血糖、肾小球滤过率(GFR)、血浆精氨酸血管加压素(AVP)、血钠及血浆渗透压,并用选择性AVP受体Ⅰ(V1)的放射配体~(125)I[d(CH_2)_5-Sarcosine~7]AVP对肾髓质膜和肝细胞膜V1受体进行结合分析。实验分三组:糖尿病组(D组)、胰岛素治疗组(T组)和对照组(C组)。结果表明,糖尿病形成2周时,各组血糖值为:D=37±7.5mmol/L;T=19±5.78mmol/L: C=7.63±0.59mmol/L。DT两组的GFR均增加,血浆AVP在D组明显高于对照组。膜受体结合试验显示:肾髓质膜V1受体最大结合容量(Bmax)在各组均无明显差异,解离常数(Kd值)D组大于T、C两组,肝细胞膜Bmax在T组增加,而Kd值在各组均未见改变。     

情感虐待等社会心理因素与初中生抑郁情绪关系的研究

目的 探讨情感虐待、家庭结构、亲友支持和D型人格等社会心理因素与初中生抑郁情绪的关系.方法 以分层整群抽样法,调查广州市5个区3160名初中-年级学生,采用儿童抑郁障碍自评量表、亲子冲突策略量表、D型人格量表、自编一般情况、家庭结构、亲友支持问卷对他们进行调查,并用相关和路径分析方法探讨情感虐待等社会心理网素与初中生抑郁的关系及联系的途径.结果 (1)女生的抑郁得分(11.2)显著高于男生(10.3)(t=-4.27,P＜0.001),年龄与抑郁得分呈显著正相关(r=0.06,P=0.001).(2)相关分析显示,亲友支持是抑郁的保护因素,情感虐待、D型人格、非双亲家庭是抑郁的危险因素.(3)路径分析发现,负性情感对抑郁影响最大(路径系数为0.37),其次是亲友支持(-0.246)、情感虐待(0.203)、社交抑制(0.075)和家庭结构(0.047),各路径系数检验均具有统计学意义.情感虐待主要经负性情感和亲友支持间接影响抑郁,路径系数分别为0.119和0.05.家庭结构对抑郁的影响最小,且为间接效应.结论 初中生的抑郁情绪受情感虐待等多个社会心理的影响,故应采取综合措施预防其抑郁情绪的发生和发展.

Abstract：

Objective To investigate the association between emotional abuse, family structure, family support, type D personality and depressive symptom in junior high school students.Methods 3160 junior high school students were recruited with stratified sampling method in Guangzhou to conmplete a self-administered questionnaire including Depression Self-rating Scale for Children, Parent-Child Conflict Tactic Scale, Type D Scale-14, Family Structure Scale, Relative Support Scale and general information. Correlation and path analysis were performed to explore the association of emotional abuse, family structure, family support and type D personality with depressive symptom and their potential pathways. Results ( 1 ) The average level of depressive symptom was higher in girls than in boys, and age was positively related to depressive disorder (r = 0.06, P = 0.001 ).(2)Correlation analysis indicated that family support was a protective factor for depressive symptom,while emotional abuse, type D personality and family structure with single parent were risk factors for depressive symptom. (3)Data from Path analysis showed that the negative affection had the strongest impact on depressive symptom with a path coefficient of 0.37, followed by family support (-0.246),emotional abuse (0.203), social inhibition (0.075) and family structure (0.047). All the path coefficients were statistically significant. Emotional abuse indirectly impacted on depressive disorder through negative affectivity and family support (the path coefficients were 0.119 and 0.05,respectively), while family structure had the smallest indirect impact on depressive symptom.Conclusion Depressive symptom in junior high school students was affected by multiple psychosocial factors, suggesting that comprehensive measures should be taken to prevent the occurrence and development of depressive symptom.