Cell Biology of Diabetic Microvascular Complications

糖尿病微血管并发症的细胞生物学

• 批准号: 7266763
• 负责人: GEORGE L KING
• 金额: $ 41.5万
• 依托单位: JOSLIN DIABETES CENTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7266763
• 关键词: 1,2-diacylglycerol; Adverse effects; Affect; Animals; Apoptosis; Arteries; Basement membrane; Biochemical; Blood Vessels; Blood flow; Capillary Permeability; Cardiac; Cardiovascular Pathology; Cardiovascular system; Cell Adhesion Molecules; Cell model; Cells; Cellular biology; Clinical; Clinical Research; Clinical Trials; Condition; Data; Development; Diabetes Mellitus; Diabetic Angiopathies; Diabetic Retinopathy; Diglycerides; Elevation; Endothelial Cells; Endothelin-1; Enzyme Activation; Functional disorder; Glomerular Filtration Rate; Glucose; Hyperglycemia; Kidney; Kidney Glomerulus; Laboratories; Lesion; Leukocytes; MAP Kinase Gene; MAPK14 gene; Mediating; Membrane Proteins; Memory; Metabolic; Mitogen-Activated Protein Kinases; Modeling; Mus; Myelin P2 Protein; Myocardium; NADPH Oxidase; Oxidative Stress; Pathogenesis; Pathology; Pathway interactions; Patients; Pericytes; Phase; Phenotype; Physiological; Platelet-Derived Growth Factor; Play; Production; Protein Biosynthesis; Protein Isoforms; Protein Kinase C; Protein Overexpression; Proteins; Proteinuria; Proto-Oncogene Proteins c-akt; Renal Plasma Flow; Renal function; Reporting; Resolution; Retina; Retinal; Retinal Diseases; Role; Signal Transduction; Signaling Molecule; Testing; Tight Junctions; Tissues; Transforming Growth Factors; Transgenic Mice; Vascular Endothelial Growth Factors; Vascular Permeabilities; Visual Acuity; angiogenesis; animal data; base; cadherin 5; capillary bed; citrate carrier; cytokine; diabetic; genetic regulatory protein; hemodynamics; inhibitor/antagonist; macular edema; monocyte; occludin; prevent; promoter; retina blood vessel structure; ruboxistaurin; transcription factor

DESCRIPTION (provided by applicant): We proposed that many of the retinal, renal and cardiovascular pathologies in diabetes are due to the activation of diacylglycerol (DAG) and protein kinase C (PKC), especially ¿1/2 and d isoform pathways induced by hyperglycemia (HG). A large body of evidence in cultured vascular cells and vascular tissues (retinal, renal, glomeruli, arteries and myocardium) from diabetic animals and patients have shown that DAG/ PKC pathways are activated and associated with increases in cytokine expression or activities (VEGF, ET-1, PDGF ¿ orTGF ¿, ICAM's), capillary permeability, matrix protein production, changes in signaling molecules (MAP kinases and AKT) and elevation of oxidative stress via NADPH oxidase activation. Clinical studies have shown that PKC ¿ isoform selective inhibitor ruboxistaurin (RBX) preserved visual acuity, renal function and endothelial functions in the presence of hyperglycemia. However, for diabetic retinopathy (DR), treatment with RBX did not prevent the progression to proliferative retinopathy, but accelerated the resolution of macular edema. Both basic and clinical results suggest that PKC ¿ isoform activation may selectively affect endothelial functions. We have provided preliminary data to show that hyperglycemia enhanced pericyte apoptosis, which parallels with PKC d isoform and p38 MAPK activation, remained elevated even after the cells were returned to normal glycemic condition. Thus, these results suggest that the pericyte cell model could be a model of "Metabolic Memory" as observed in clinical studies. Thus, we are proposing that the differential activation of PKC ¿ 1/2 and d isoforms induced by hyperglycemia, are causing different and specific cellular changes in retinal endothelial cells and pericytes, respectively. Thus, to prevent the progression of DR, both PKC ¿ 1/2 and d isoforms may need to be normalized. To test this new hypothesis, we will: (1) identify the specific signaling mechanisms by which PKC ¿ 1/2 and d isoforms are mediating their different effects in retinal endothelial cells (activation of ERK1/2 MAPK-occludin and others) and pericytes (p38 MAPK, NADPH oxidases) ¿ and others; (2) define the isoform selective roles of PKC ¿ 1/2 and d isoforms on the various changes in biochemical, hemodynamic and pathological parameters observed in the endothelial cells and pericytes by using control and diabetic PKC ¿-/- and d-/- mice and endothelial cell targeted overexpression of PKCP2 in C57/BL6 mice. Finally, the idea of dual activation of PKC ¿ / d isoforms are needed to induce DR will be tested by treating diabetic PKC d-/- mice with PKC ¿ specific inhibitor RBX to determine whether most of the retinal pathologies in diabetes can be prevented.

描述（由申请人提供）：我们提出，糖尿病中的许多视网膜、肾脏和心血管病变是由于二酰甘油 (DAG) 和蛋白激酶 C (PKC) 的激活，尤其是 ¿高血糖 (HG) 诱导的 1/2 和 d 异构体途径 来自糖尿病动物和患者的培养血管细胞和血管组织（视网膜、肾、肾小球、动脉和心肌）的大量证据表明，DAG/ PKC 途径是激活并与细胞因子表达或活性（VEGF、ET-1、PDGF ¿ 或 TGF ¿、ICAM's）的增加相关，毛细血管临床研究表明，PKC ¿异构体选择性抑制剂 ruboxistaurin (RBX) 在高血糖的情况下可以保留视力、肾功能和内皮功能，然而，对于糖尿病性视网膜病变 (DR)，RBX 治疗并不能阻止进展为增殖性视网膜病变，而是加速了黄斑水肿的消退。基础和临床结果均表明 PKC ¿同种型激活可能选择性地影响内皮功能。我们提供的初步数据表明，高血糖会增强周细胞凋亡，这与 PKC d 同种型和 p38 MAPK 激活相似，即使在细胞恢复到正常血糖条件后，细胞凋亡仍然升高。周细胞模型可能是临床研究中观察到的“代谢记忆”模型，因此，我们提出 PKC 的差异激活 ¿高血糖诱导的 1/2 和 d 异构体分别引起视网膜内皮细胞和周细胞的不同和特异性细胞变化，因此，为了防止 DR 的进展，PKC ¿ 1/2 和 d 同工型可能需要标准化，为了检验这一新假设，我们将：(1) 确定 PKC ¿ 的具体信号传导机制。 1/2 和 d 同种型在视网膜内皮细胞（ERK1/2 MAPK-occludin 等的激活）和周细胞（p38 MAPK、NADPH 氧化酶）中介导其不同作用 ¿等；(2) 定义 PKC 的同种型选择性作用 ¿使用对照和糖尿病 PKC 观察内皮细胞和周细胞中生化、血流动力学和病理参数的各种变化的 1/2 和 d 异构体 ¿ -/- 和 d-/- 小鼠以及内皮细胞在 C57/BL6 小鼠中靶向过度表达 PKCP2 最后，双重激活 PKC 的想法 ¿诱导 DR 需要 /d 异构体，将通过用 PKC 治疗糖尿病 PKC d-/- 小鼠来测试 ¿特异性抑制剂 RBX 来确定是否可以预防大多数糖尿病视网膜病变。