Yang Bin, Jain Sunjay, Ashra Shairbanu Y, Furness Peter N, Nicholson Michael L
Department of Infection, Immunity and Inflammation, University of Leicester, Leicester General Hospital, UK.
Transplantation. 2006 May 27;81(10):1442-50. doi: 10.1097/01.tp.0000209412.77312.69.
Caspase-3 plays a key role in apoptosis, but the involvement of apoptosis and caspase-3 in mediating long-term ischemia/reperfusion (I/R) and immunosuppressive injury are not fully defined. The present study was undertaken to investigate apoptosis and caspase-3 in a renal I/R injury rat model with or without immunosuppression.
The right renal pedicle was clamped for 45 minutes and left nephrectomy was induced. Cyclosporin A (CsA), tacrolimus (Tac), rapamycin (Rap), or mycophenolate mofetil (MMF) were administered daily. Animals were killed at 16 weeks, and the levels of apoptosis (with in situ end-labeling fragmented DNA), caspase-3 protein (with immunohistochemistry, Western blotting, and activity assay), and messenger RNA (mRNA; with quantitative reverse-transcriptase polymerase chain reaction) were evaluated.
Kidneys with I/R injury showed increased apoptosis in tubular and interstitial areas compared with control kidneys. Tacrolimus, Rap, and MMF significantly reduced apoptosis, but CsA did not. Distribution of full-length caspase-3 widened in I/R-injured kidneys from normal distal tubules and collecting ducts to dilated proximal tubules and expanded interstitium, whereas active caspase-3 was mainly scattered in damaged tubules and interstitium. Active caspase-3 staining and 24-kDa active caspase-3 protein was enhanced in I/R-injured and CsA-treated kidneys, but decreased by Tac, Rap, and MMF. These results were also consistent with changes in caspase-3 activity. Although caspase-3 mRNA levels were significantly increased in uninephrectomy and I/R-injured kidneys, they were not significantly affected by the immunosuppressants. In addition, all changes detected were positively correlated with renal structure and function.
Apoptosis and caspase-3 are not only involved in the long-term renal I/R injury, but also mediate the divergent effects of immunosuppression in this model.
半胱天冬酶 - 3在细胞凋亡中起关键作用，但细胞凋亡和半胱天冬酶 - 3在介导长期缺血/再灌注（I/R）和免疫抑制损伤中的作用尚未完全明确。本研究旨在探讨有无免疫抑制的肾I/R损伤大鼠模型中的细胞凋亡和半胱天冬酶 - 3。
夹闭右侧肾蒂45分钟并诱导左肾切除术。每天给予环孢素A（CsA）、他克莫司（Tac）、雷帕霉素（Rap）或霉酚酸酯（MMF）。16周时处死动物，评估细胞凋亡水平（采用原位末端标记破碎DNA法）、半胱天冬酶 - 3蛋白水平（采用免疫组织化学、蛋白质印迹法和活性测定法）以及信使核糖核酸（mRNA；采用定量逆转录聚合酶链反应法）。
与对照肾相比，I/R损伤的肾在肾小管和间质区域的细胞凋亡增加。他克莫司、雷帕霉素和霉酚酸酯显著减少细胞凋亡，但环孢素A未减少。全长半胱天冬酶 - 3的分布在I/R损伤的肾中从正常的远端小管和集合管扩展到扩张的近端小管和扩大的间质，而活性半胱天冬酶 - 3主要散在于受损的小管和间质中。活性半胱天冬酶 - 3染色和24 kDa活性半胱天冬酶 - 3蛋白在I/R损伤和CsA处理的肾中增强，但在他克莫司、雷帕霉素和霉酚酸酯处理后降低。这些结果也与半胱天冬酶 - 3活性的变化一致。虽然在单侧肾切除和I/R损伤的肾中半胱天冬酶 - 3 mRNA水平显著升高，但它们未受到免疫抑制剂的显著影响。此外，检测到的所有变化均与肾结构和功能呈正相关。
细胞凋亡和半胱天冬酶 - 3不仅参与长期肾I/R损伤，还介导该模型中免疫抑制的不同作用。
