Neymeyer H, Labes R, Reverte V, Saez F, Stroh T, Dathe C, Hohberger S, Zeisberg M, Müller G A, Salazar J, Bachmann S, Paliege A
Department of Anatomy, Charité Universitätsmedizin Berlin, Berlin, Germany.
Department of Physiology, School of Medicine, University of Murcia, Murcia, Spain.
Acta Physiol (Oxf). 2015 Nov;215(3):144-58. doi: 10.1111/apha.12586. Epub 2015 Sep 22.
The anti-inflammatory protein annexin A1 (AnxA1) and its formyl peptide receptor 2 (FPR2) have protective effects in organ fibrosis. Their role in chronic kidney disease (CKD) has not yet been elucidated. Our aim was to characterize the AnxA1/FPR2 system in models of renal fibrosis.
Rats were treated with angiotensin receptor antagonist during the nephrogenic period (ARAnp) to induce late-onset hypertensive nephropathy and fibrosis. Localization and regulation of AnxA1 and FPR2 were studied by quantitative real-time PCR and double labelling immunofluorescence. Biological effects of AnxA1 were studied in cultured renal fibroblasts from AnxA1(-/-) and wild-type mice.
Angiotensin receptor antagonist during the nephrogenic period kidneys displayed matrix foci containing CD73(+) fibroblasts, alpha-smooth muscle actin (a-SMA)(+) myofibroblasts and CD68(+) macrophages. TGF-β and AnxA1 mRNAs were ~threefold higher than in controls. AnxA1 was localized to macrophages and fibroblasts; myofibroblasts were negative. FPR2 was localized to fibroblasts, myofibroblasts, macrophages and endothelial cells. AnxA1 and FPR2 immunoreactive signals were increased in the foci, with fibroblasts and macrophages expressing both proteins. AnxA1(-/-) fibroblasts revealed higher α-SMA (sevenfold) and collagen 1A1 (Col1A1; 144-fold) mRNA levels than controls. Treatment of murine WT fibroblasts with TGF-β (22.5 ng mL 24 h(-1)) increased mRNA levels of α-SMA (9.3-fold) and Col1A1 (fourfold). These increases were greatly attenuated upon overexpression of AnxA1 (1.5- and 1.7-fold, respectively; P < 0.05). Human fibroblasts reacted similarly when receiving the FPR2 inhibitor WRW4.
Our results demonstrate that AnxA1 and FPR2 are abundantly expressed in the renal interstitium and modulate fibroblast phenotype and extracellular matrix synthesis activity.
抗炎蛋白膜联蛋白A1（AnxA1）及其甲酰肽受体2（FPR2）在器官纤维化中具有保护作用。它们在慢性肾脏病（CKD）中的作用尚未阐明。我们的目的是在肾纤维化模型中对AnxA1/FPR2系统进行表征。
在肾发生期用血管紧张素受体拮抗剂处理大鼠（ARAnp）以诱导迟发性高血压肾病和纤维化。通过定量实时PCR和双标免疫荧光研究AnxA1和FPR2的定位及调控。在来自AnxA1（-/-）和野生型小鼠的培养肾成纤维细胞中研究AnxA1的生物学效应。
在肾发生期用血管紧张素受体拮抗剂处理的肾脏显示出含有CD73（+）成纤维细胞、α平滑肌肌动蛋白（α-SMA）（+）肌成纤维细胞和CD68（+）巨噬细胞的基质灶。转化生长因子-β（TGF-β）和AnxA1 mRNA比对照组高约三倍。AnxA1定位于巨噬细胞和成纤维细胞；肌成纤维细胞为阴性。FPR2定位于成纤维细胞、肌成纤维细胞、巨噬细胞和内皮细胞。AnxA1和FPR2免疫反应信号在病灶中增加，成纤维细胞和巨噬细胞均表达这两种蛋白。AnxA1（-/-）成纤维细胞显示出比对照组更高的α-SMA（7倍）和胶原蛋白1A1（Col1A1；144倍）mRNA水平。用TGF-β（22.5 ng mL 24 h-1）处理小鼠野生型成纤维细胞可增加α-SMA（9.3倍）和Col1A1（4倍）的mRNA水平。在AnxA1过表达时，这些增加显著减弱（分别为1.5倍和1.7倍；P<0.05）。人成纤维细胞在接受FPR2抑制剂WRW4时反应相似。
我们的结果表明，AnxA1和FPR2在肾间质中大量表达，并调节成纤维细胞表型和细胞外基质合成活性。
