糖尿病腎病變是一種糖尿病患者嚴重的併發症。大約 30-40％第一型糖尿病患者和15％第二型糖尿病患者會惡化成末期的腎臟疾病。糖尿病腎病變中即使在無微白蛋白尿症的症狀，亦會造成近端腎小管上皮細胞的凋亡及腎小管功能障礙，這說明了腎小管與間質在糖尿病腎病惡化的關鍵角色。然而腎小管上皮細胞的腎小管功能不良、腎小管上皮細胞凋亡與超顯微結構形態的改變目前仍然不知其確切的機轉。西洛他唑 (CilostazolCTZ) 是一個特殊的磷酸二酯 3 抑製劑，可防止血小板凝集，擴張血管，可用於治療周邊疾病的的缺氧症狀與間歇性跛行，依照過去的研究 CTZ 可降低活體實驗中氧化壓力，假設若 CTZ 可降低氧化壓力，是否藉由抗氧化壓力的作用來延緩糖尿病腎病變的持續惡化，與減少粒線體因氧化壓力造成的功能受損。本研究的目的是高血糖和氧化壓力對細胞凋亡的潛在影響，評估在腎臟近端小管的粒線體 DNA(mtDNA) 含量和粒線體形態的變化。在本研究中，進行了高血糖對腎臟的影響的研究與分析。測定Bcl-2、 Bax、caspasa-3 與活化型 caspase 的表現與經 CTZ 治療後的情形，以確定細胞的傷害與凋亡。採取糖尿病腎臟組織分析超顯微構造與組織學的變化。利用實時聚合鏈反應測定相對腎臟粒線體 DNA (mtDNA) 的含量。結果顯示，CTZ 在對糖尿病老鼠的治療組可降低腎絲球基底膜的厚度，以及改善系膜基質的擴大，此外，超顯微構造與組織學的觀察研究，CTZ 可以恢復腎小管上皮細胞中粒線體的形態。亦可減少細胞凋亡。利用實時聚合鏈反應測定相對腎臟粒線體 DNA，發現糖尿病老鼠腎臟檢體 mtDNA 拷貝數會增加。經 CTZ 治療後，mtDNA 含量降低而且接近正常。 Diabetic nephropathy is a serious complication for patients with diabetes mellitus (DM). Approximately 30-40% of patients with type I and 15% with type II DM develop end-stage renal disease. Proximal tubular epithelial cells apoptosis and tubular dysfunction has been reported in DM even in the absence of microabuminuria, which suggests a pivotal role of tubul-interstitium in the development of diabetic nephropathy. But exact mechanism underlying tubular malfunction and ultra-structural morphological alteration of proximal tubular epithelial cells in DM remains unknown. Cilostazol is a specific inhibitor of phosphodiesterase 3, which prevents platelet aggregation and dilates blood vessels. Previous study has shown that cilostazol decreased reactive oxygen species activity significantly in the kidneys of diabetic rats. The aim of this study is focus on the potential effects of hyperglycemia and oxidative stress in apoptosis, mitochondrial DNA (mtDNA) content and mitochondrial morphological alteration in proximal tubule of kidney. The effect of hyperglycemia on kidney is investigated and analyzes the changes in Bcl-2, Bax，caspasa-3 and cleaved-caspase expression after treatment with cilostazol to identify the apoptotic cell damage. Diabetic kidneys are sampled for the quantity of relative kidney mitochondrial DNA (mtDNA) content. The results showed that Cilostazol can decrease the thickness of glomerular basement membrane, and the expansion of the mesangial matrix is regressed in diabetic rats under ultra-structural and histological evaluation, It also restores mitochondrial morphology in proximal tubular epithelial cells and reduces apoptosis. As measured by real time PCR , Mt DNA copy number is increased in diabetic rats but it shows a decrease manner close to the normal group after Cilostazol treatment.
