Pathophysiological Roles of Peroxisome Proliferator Activated Receptor (PPAR) on Development and Progression of Chronic kidney diseases -Search for a New Therapeutic Target for Chronic Kidney Diseases-

(1)过氧化物酶体增殖物激活受体(PPAR)对肾小球细胞的致病作用：在培养的大鼠肾小球系膜细胞中，高糖(25 MM)可促进血管内皮生长因子(VEGF)的产生和DNA合成，而PPAR激动剂噻唑烷二酮对此有抑制作用。在18例早期2型糖尿病肾病患者的肾组织标本中，原位杂交检测的肾小球血管内皮生长因子信使RNA的表达与肾小球系膜基质区和血管极部新生血管的形成密切相关。我们报告一例POEMS(Crow-Fukase)综合征合并2型糖尿病，与血浆血管内皮生长因子水平升高有关，但没有糖尿病肾病的迹象。我们还检测了正常、微量和大量白蛋白尿的2型糖尿病患者的血浆血管内皮生长因子浓度，结果表明，糖尿病肾病的存在是n…循环血浆中的血管内皮生长因子浓度升高的可能性更大。(2)腺病毒载体基因转移系统的建立及其在肾脏疾病模型动物中的应用：建立了实时荧光定量聚合酶链式反应(RT-Real-time PCR，光周期技术)和编码PPAR的腺病毒载体、PAF-AH基因(AdhPPAR、AdhPAF-AH)的基因转移系统，证实其在不同的细胞培养体系中均有表达。将AdhPAF-AH转移到肾硬化症模型动物(SHC大鼠)体内，通过PAF-AH在肝脏的表达抑制肾硬化，并通过高密度脂蛋白颗粒转移到肾脏。建立肾脏特异、有效的基因转移系统将促进AdhPPAR、、和AdhPAF-AH在糖尿病肾病或IgA肾病等常见肾脏疾病模型动物的基因治疗中的应用。(3)PPAR及其相关因素在肾脏疾病动物模型中的病理生理作用：给免疫球蛋白A肾病模型小鼠(HIGA小鼠)喂饲亚麻酸(6系列多不饱和脂肪酸)或亚麻酸(6系列多不饱和脂肪酸)。与饲喂亚油酸相比，饲喂亚麻酸可抑制蛋白尿、肾功能障碍(血肌酐升高)和肾小球硬化改变，提示其可能参与肾病的发病机制和PPAR治疗IgA肾病的潜在靶点。前列腺素(PUFA衍生的金盏花素)在肾脏中的生理作用被用它们的受体Knoch-out mce检测，提示盐敏感性部分依赖于前列腺素，但缺血性急性肾功能衰竭。此外，在不改变血压的自发性高血压大鼠(SHR)的病理组织学变化的情况下，将微量稀释剂直接稀释到单侧肾切除大鼠的残余肾中，盐负荷的1型血管紧张素II受体(AT1)蛋白尿大鼠和自发性高血压大鼠(GT；(4)针对慢性肾脏疾病心血管事件的临床研究：我们登记了大约600名HD患者，并对导致心血管事件的临床参数进行了横断面检查，结果显示，事件的最强预测因素是炎症(CRP)，其次是糖尿病等，ARB和/或ACE抑制剂的使用除了体重、血清白蛋白和体重代表良好的营养状态和血液透析(HD)的有效性(Kt/V)外，还改善了患者的生活预后。摄入亚麻酸可改善对照组的C反应蛋白，但不能改善血液透析患者的C反应蛋白(手稿正在准备中)，这部分解释了血液透析患者心血管事件所致的不良预后。较少

(1)Pathogenetic actions of Peroxisome Proliferator Activated Receptor (PPAR) on glomerular cells: In rat mesangial cells in culture, high ambient glucose(25mM), especially when fluctuated time by time, promoted Vascular Endothelial Growth Factor(VEGF) production and DNA synthesis, which is inhibited by treatment of the cells with a thiazolizinedione, a PPAR, agonist. In the kidney specimens from 18 type 2 patients with early stage of diabetic nephropathy, glomerular VEGF messenger RNA expression determined by in situ hybridization is well correlated with neovasculization at the vascular pole and mesangial matrix area^<1)> (glomerular sclerosis) ^<6)>. We presented a case of POEMS (Crow-Fukase) syndrome with Type 2 diabetes, which was associated with elevated plasma VEGF level, but no sign of diabetic nephropathy^<8)>. We also measured plasma VEGF concentration in Type 2 diabetic patients with normo-, micro, and macro-albuminuria, the results of which showed that the presence of DN is n … More ot associated with an elevation of circulating plasma VEGF concentration2). These results suggest that overproduction of VEGF in situ in the kidney may play a local pathogenetic role in early-stage DN, which is dependent on PPAR,and PKC.(2)Establishment of gene transfer system using adenovirus vector and application for model animals with renal diseases : We established a system of mRNA measurement by RT-real time PCR(light-cycler) and that of gene transfer system using adeno-virus vector encoding PPAR,, and PAF-AH cDNA (AdhPPAR,,nd AdhPAF-AH) which are confirmed to express respective mRNA and protein in various culture cell systems.First, AdhPAF-AH was trasfected to a nephrosclerosis model animal (SHC rat), which resultantly inhibited nephrosclerosis through PAF-AH expression in the liver and transferred to the kidney on HDL particles12). Estabulishment of kidney specific, effective gene transfer system would promote application of AdhPPAR,、,nd AdhPAF-AH for gene therapy of various model animals for common renal disease such as diabetic nephropathy or IgA nephropathy.(3)Pathogenetic roles of PPAR and its related factors for the pathophysiology in animal models with renal diseases: IgA nephropathy model mice (HIGA mouse) were feeded with,inolenic acid (an, 3 series poly-unsaturated fatty acid (PUFA))-or linolic acid (, 6 series PUFA) which are also possible ligands for PPAR. Feeding with,inolenic acid compared to that with linolic acid inhibited proteinuria, renal dysfunction(increase in plasma creatinine) and glomerular sclerotic change^<13)>, suggesting a potential involvement in pathogenesis and a potential therapeutic target of PPAR for IgA nephropathy. The physiological roles of prostanoids (PUFA-derived autacoid) in the kidney are tested using their receptor knoch-out mce, suggesting that salt-sensitivity is partly dependent upon prostanoids^<10)>, but ischemic acute renal failure^<3)>. In additon, direct micro-dilution into the remnant kidney in unilateral nephrectomizen, salt-loaded rats of an anti-sense oligonucleotide to type 1 angiotensin II receptor(AT1) amelionate proteinuria and patho-histological changes without changing blood pressure in spontaneous hypertensive rats (SHR) ^<11)>, supporting the concept that angiotensin II locally produced plays a significant roles in progression of renal dysfunction via ATI receptor signals.(4)Clinical studies targeted for cardio-vascular events in chronic kidney diseases : We registered about 600 HD patients and cross-sectionally examined the clinical parameters responsible for incidence of cardiovascular, which showed that the strongest predictor for events is inflammation (CRP) followed by diabetes and so forth and that use of ARB and/or ACE inhibitors inaddition of BW, serum albumin and body weight representative for good nutritional state and effectiveness of hemodialysis (HD) (Kt/V) improved life prognosis^<5)>. Intake of, inolenic acid improved CRP in the control population, but not in the HD patients (manuscript in preparation), explaining partly poor prognosis due to cardiovascular events of HD patients. Less