Novel anti-inflammatory mechanisms of N-Acetyl-Ser-Asp-Lys-Pro in hypertension-induced target organ damage
Novel anti-inflammatory mechanisms of N-Acetyl-Ser-Asp-Lys-Pro in hypertension-induced target organ damage
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DOI：
10.1152/ajpheart.00305.2007
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发表时间：
2008-03-01
影响因子：
4.8
通讯作者：
Carretero, Oscar A.
中科院分区：
文献类型：
--
作者：
Sharma, Umesh;Rhaleb, Nour-Eddine;Carretero, Oscar A.
高血压（HBP）是心脏、肾脏和血管功能障碍的重要危险因素。过度炎症是hbp诱导靶器官损伤（target organ damage， TOD）的主要致病机制。n -乙酰基ser - asp - lys - pro （AcSDKP）是一种由血管紧张素转换酶（ACE）特异性降解的四肽，可减轻高血压引起的炎症、纤维化和TOD。我们的假设是，Ac-SDKP通过抑制：1)骨髓干细胞向巨噬细胞的分化，2)巨噬细胞的活化和迁移，3)活化的巨噬细胞释放促炎细胞因子tnf - α来发挥其抗炎作用。新鲜分离的BMSC在巨噬细胞生长培养基中培养。流式细胞术分析小鼠骨髓间充质干细胞向巨噬细胞的分化，以F4/80作为巨噬细胞成熟的标志。在改良的Boyden室中测量巨噬细胞的迁移。ELISA法检测培养后活化巨噬细胞tnf - α释放量。采用免疫印迹法研究了angii诱导的高血压小鼠心肌巨噬细胞的活化。小天狼星红染色测定间质胶原沉积。我们发现Ac-SDKP （10 nM）使培养的BMSC向成熟巨噬细胞的分化减少24.5% [F4/80阳性：平均荧光强度为14.09 +/- 1.06，Ac-SDKP为10.63 +/- 0.35；P < 0.05]。Ac-SDKP还能减少半乳糖凝集素-3和巨噬细胞集落刺激因子依赖的巨噬细胞迁移。此外，AcSDKP还能降低细菌LPS刺激下巨噬细胞tnf - α的分泌。在ANG ii诱导的高血压小鼠中，Ac-SDKP降低了半乳糖凝集素-3的表达和间质胶原沉积。半乳糖凝集素-3是一种通过浸润心肌巨噬细胞产生的蛋白质。综上所述，本研究表明Ac-SDKP的部分抗炎作用是由于其直接作用于BMSC和巨噬细胞，抑制其分化、活化和细胞因子的释放。这些作用解释了Ac-SDKP在高血压中的一些抗炎和抗纤维化特性。
High blood pressure (HBP) is an important risk factor for cardiac, renal, and vascular dysfunction. Excess inflammation is the major pathogenic mechanism for HBP-induced target organ damage (TOD). N-acetyl-Ser-Asp-Lys-Pro (AcSDKP), a tetrapeptide specifically degraded by angiotensin converting enzyme (ACE), reduces inflammation, fibrosis, and TOD induced by HBP. Our hypothesis is that Ac-SDKP exerts its anti-inflammatory effects by inhibiting: 1) differentiation of bone marrow stem cells (BMSC) to macrophages, 2) activation and migration of macrophages, and 3) release of the proinflammatory cytokine TNF-alpha by activated macrophages. BMSC were freshly isolated and cultured in macrophage growth medium. Differentiation of murine BMSC to macrophages was analyzed by flow cytometry using F4/80 as a marker of macrophage maturation. Macrophage migration was measured in a modified Boyden chamber. TNF-alpha release by activated macrophages in culture was measured by ELISA. Myocardial macrophage activation in mice with ANG II-induced hypertension was studied by Western blotting of Mac-2 (galectin-3) protein. Interstitial collagen deposition was measured by picrosirius red staining. We found that Ac-SDKP (10 nM) reduced differentiation of cultured BMSC to mature macrophages by 24.5% [F4/80 positivity: 14.09 +/- 1.06 mean fluorescent intensity for vehicle and 10.63 +/- 0.35 for Ac-SDKP; P < 0.05]. Ac-SDKP also decreased galectin-3 and macrophage colony-stimulating factor-dependent macrophage migration. In addition, AcSDKP decreased secretion of TNF-alpha by macrophages stimulated with bacterial LPS. In mice with ANG II-induced hypertension, Ac-SDKP reduced expression of galectin-3, a protein produced by infiltrating macrophages in the myocardium, and interstitial collagen deposition. In conclusion, this study demonstrates that part of the anti-inflammatory effect of Ac-SDKP is due to its direct effect on BMSC and macrophage, inhibiting their differentiation, activation, and cytokine release. These effects explain some of the anti-inflammatory and antifibrotic properties of Ac-SDKP in hypertension.