Department of Nephrology, Xiangya Hospital of Central South University, Changsha, PR China.
Ren Fail. 2011;33(2):207-16. doi: 10.3109/0886022X.2011.553979.
This study aims to investigate the role of Notch pathway in the renal ischemia/reperfusion injury (IRI)-associated inflammation and apoptosis.
Male Sprague-Dawley rats were divided into three groups: normal saline (NS)-treated sham rats, NS-treated ischemia/reperfusion (I/R) rats, and N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester (DAPT) (a γ-secretase inhibitor) treated I/R rats. I/R rat model underwent nephrectomy of the right kidney and was subjected to 60 min of left renal pedicle occlusion followed by 24 h, 48 h, and 72 h of reperfusion, respectively. The levels of creatinine, urea nitrogen (BUN), interleukin (IL)-6, tumor necrosis factor (TNF)-α in serum samples and urinary N-acety-β-d-glucosaminidase (NAG) were assayed. Histological examinations were performed. The protein expression of Notch2, hairy/enhancer of split 1 (hes-1), NF-κB2, monocyte chemoattractant protein (MCP)-1, B-cell lymphoma 2 (bcl-2), and bcl-2-associated X (bax) were detected and the degree of apoptosis of tubular cells was evaluated.
Renal IR induced severe tubular damage, caused significant increases in the Scr, BUN, IL-6, TNF-α, urinary NAG, Notch2, hes-1, NF-κB2, MCP-1, ratio of tubule cells apoptosis, and reduction in the ratio of bcl-2 to bax. However, DAPT treatment significantly reduced the level of Scr, BUN, IL-6, TNF-α, and NAG. Thus, I/R activates Notch2/hes-1 signaling and DAPT treatment can ameliorate the severity of tubular damage after renal IRI, lower the expression of NF-κB2, MCP-1, and bax protein, increase the expression of bcl-2 protein, and reduce the ratio of terminal 2-deoxyuridine 5-triphosphate nick end-labeling-positive cells.
Notch signaling plays an important role in the renal IRI-associated inflammation and apoptosis. DAPT can protect against IRI through partly suppressing inflammation and apoptosis, which could constitute a new target for AKI.
本研究旨在探讨 Notch 通路在肾缺血再灌注损伤（IRI）相关炎症和细胞凋亡中的作用。
雄性 Sprague-Dawley 大鼠分为三组：生理盐水（NS）处理的假手术组、NS 处理的 I/R 组和 N-[N-(3,5-二氟苯乙酰基)-L-丙氨酰]-S-苯甘氨酸叔丁酯（DAPT）（γ-分泌酶抑制剂）处理的 I/R 组。I/R 大鼠模型行右肾切除术，左肾蒂夹闭 60 min 后分别再灌注 24 h、48 h 和 72 h。检测血清样本中肌酐、尿素氮（BUN）、白细胞介素（IL）-6、肿瘤坏死因子（TNF）-α以及尿 N-乙酰-β-D-氨基葡萄糖苷酶（NAG）水平。进行组织学检查。检测 Notch2、头发状增强子分裂 1（hes-1）、核因子（NF）-κB2、单核细胞趋化蛋白（MCP）-1、B 细胞淋巴瘤 2（bcl-2）和 Bcl-2 相关 X（bax）的蛋白表达，并评估管状细胞的凋亡程度。
肾 IRI 引起严重的肾小管损伤，导致 Scr、BUN、IL-6、TNF-α、尿 NAG、Notch2、hes-1、NF-κB2、MCP-1、肾小管细胞凋亡比例增加，bcl-2 与 bax 比例降低。然而，DAPT 治疗显著降低了 Scr、BUN、IL-6、TNF-α和 NAG 的水平。因此，IRI 激活了 Notch2/hes-1 信号通路，DAPT 治疗可减轻肾 IRI 后肾小管损伤的严重程度，降低 NF-κB2、MCP-1 和 bax 蛋白的表达，增加 bcl-2 蛋白的表达，并降低末端 2-脱氧尿苷 5-三磷酸尼克末端标记阳性细胞的比例。
Notch 信号在肾 IRI 相关炎症和细胞凋亡中起重要作用。DAPT 通过部分抑制炎症和凋亡来保护 IRI，这可能成为急性肾损伤的一个新靶点。
