低氧预处理增强了 HIF-1α 依赖性 HSP70 信号，以减少缺血性肾衰竭诱导的肾小管细胞凋亡和自噬。

Hypoxic preconditioning reinforces HIF-alpha-dependent HSP70 signaling to reduce ischemic renal failure-induced renal tubular apoptosis and autophagy.

机构信息

Division of Urology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.

出版信息

Life Sci. 2010 Jan 16;86(3-4):115-23. doi: 10.1016/j.lfs.2009.11.022. Epub 2009 Dec 4.

DOI:10.1016/j.lfs.2009.11.022

PMID:19962996

Abstract

AIMS

Repetitive hypoxic preconditioning (RHP) may provide more efficient protection than single hypoxic preconditioning against renal ischemia/reperfusion-induced injury via hypoxia-induced factor 1alpha (HIF-1alpha)-dependent heat shock protein 70 (HSP70) pathways.

MAIN METHODS

Wistar rats were subjected to intermittent hypoxic exposure (15h/day), whereas controls were kept at sea level. We evaluated renal expression of HIF-1alpha, HSP70, the endoplasmic reticulum stress protein GRP78, caspase 12, Beclin-1, and poly-(ADP-ribose)-polymerase (PARP) with western blotting. Renal apoptosis determined by terminal transferase dUTP nick end labeling (TUNEL), Beclin-1-dependent autophagy, and monocyte/macrophage (ED-1) infiltration were evaluated by immunocytochemistry. Renal function was determined with blood urea nitrogen (BUN) and plasma creatinine levels. HIF-1alpha inhibitors and Deoxyribonucleotide (DNA) or Ribonucleotide (RNA) interference of HSP70 were used to evaluate their possible roles in this process.

KEY FINDINGS

Renal HIF-1alpha and HSP70 expression were enhanced by hypoxic preconditioning and inhibited by the HIF-1alpha inhibitor, YC-1, as well as phosphatidylinositol 3-kinase (PI3K)/Akt inhibitors. After the return to normoxia, renal HSP70 protein levels were maintained for one week in the RHP group, but they decayed after one day in the single hypoxic preconditioning group. Ischemia/reperfusion significantly increased renal TUNEL-apoptosis, Beclin-1-dependent autophagy, ED-1 infiltration, expression of GRP78, caspase 12, Beclin-1, PARP, and BUN and plasma creatinine levels in control rats. RHP significantly decreased all ischemia/reperfusion-enhanced parameters. Intraperitoneal pretreatment with YC-1 and quercetin (an inhibitor of HSP70 induction) eliminated RHP-induced protection. Anti-sense oligodeoxyribonucleotides or interference RNA targeting HSP70 abrogated the protection against hypoxia/reoxygenation-induced oxidative injury in RHP-treated proximal tubules.

SIGNIFICANCE

We demonstrate that RHP promotes HIF-1alpha-dependent HSP70 signaling to reduce renal ischemia/reperfusion injury.

摘要

目的

重复低氧预处理（RHP）可能通过缺氧诱导因子 1α（HIF-1α）依赖性热休克蛋白 70（HSP70）途径提供比单次低氧预处理更有效的保护，防止肾缺血/再灌注诱导的损伤。

主要方法

Wistar 大鼠进行间歇性低氧暴露（每天 15 小时），而对照组保持在海平面。我们通过 Western 印迹评估 HIF-1α、HSP70、内质网应激蛋白 GRP78、半胱天冬酶 12、Beclin-1 和聚（ADP-核糖）-聚（PARP）的肾表达。通过末端转移酶 dUTP 缺口末端标记（TUNEL）评估肾细胞凋亡，通过免疫细胞化学评估 Beclin-1 依赖性自噬和单核细胞/巨噬细胞（ED-1）浸润。通过血尿素氮（BUN）和血浆肌酐水平来评估肾功能。使用 HIF-1α抑制剂和 HSP70 的脱氧核苷酸（DNA）或核糖核苷酸（RNA）干扰来评估它们在这个过程中的可能作用。

主要发现

低氧预处理增强了肾 HIF-1α和 HSP70 的表达，并被 HIF-1α 抑制剂 YC-1 以及磷脂酰肌醇 3-激酶（PI3K）/Akt 抑制剂抑制。在返回常氧后，RHP 组的肾 HSP70 蛋白水平在一周内维持，但在单次低氧预处理组中，在一天后就衰减了。缺血/再灌注在对照组大鼠中显著增加了肾 TUNEL 凋亡、Beclin-1 依赖性自噬、ED-1 浸润、GRP78、半胱天冬酶 12、Beclin-1、PARP 和 BUN 及血浆肌酐水平。RHP 显著降低了所有缺血/再灌注增强的参数。腹腔内预先给予 YC-1 和槲皮素（HSP70 诱导抑制剂）消除了 RHP 诱导的保护作用。针对 HSP70 的反义寡脱氧核苷酸或干扰 RNA 消除了 RHP 处理的近端肾小管对缺氧/复氧诱导的氧化损伤的保护作用。