Câmpean Valentina, Karpe Britta, Haas Christian, Atalla Akram, Peters Harm, Rupprecht Harald, Liebner Stefan, Acker Till, Plate Karl, Amann Kerstin
Department of Pathology, University of Erlangen-Nürnberg, Krankenhausstr. 12, 91054 Erlangen, Germany.
Am J Physiol Renal Physiol. 2008 May;294(5):F1174-84. doi: 10.1152/ajprenal.00320.2007. Epub 2008 Feb 13.
Capillary neoformation is important in repair of glomerular injury of various origins. VEGF was shown to be crucial for glomerular capillary repair in glomerulonephritis (GN). We reasoned that other angiogenic factors are likewise involved in glomerular capillary remodeling and found angiopoietin 1 and -2 (ANG1 and ANG2) mRNA to be upregulated in cDNA microarrays of microdissected glomeruli of anti-Thy1.1 GN of the rat. We then studied glomerular in situ gene and protein expression of ANG1 and ANG2 and their receptor Tie-2 in the course of anti-Thy1.1 GN, which was induced by injection of OX-7 antibody. Animals were perfusion fixed at days 6 and 12 after GN induction and compared with nonnephritic controls receiving PBS. Capillary damage and repair were quantitatively analyzed using stereological techniques. Gene and protein expression of ANG1 and ANG2 and their receptor Tie-2 was analyzed using real-time quantitative PCR from microdissected glomeruli, nonradioactive in situ hybridization, double immunofluorescence, and Western blot analysis. Glomerular capillarization assessed as length density was significantly lower at day 6 of anti-Thy1.1 GN than in controls; it was back to normal values at day 12. ANG1 and ANG2 gene expression was markedly upregulated at day 6 of the disease compared with controls. Protein expression of ANG1 and ANG2 was confined to podocytes and that of Tie-2 to endothelial cells. At day 12 of anti-Thy1.1 GN when capillary restoration was nearly completed, ANG1 and ANG2 gene expression returned to basal levels, whereas Tie-2 expression was still high. With the use of a combined molecular and in situ approach, the spatial and temporal gene and protein expression of the angiopoietins and their receptor was analyzed in anti-Thy1.1 GN. The results indicate that glomerular expression of ANG1 and ANG2 and Tie-2 is differentially regulated and may contribute to healing and endothelial cell stabilization in experimental GN.
毛细血管新生在各种原因引起的肾小球损伤修复中具有重要作用。血管内皮生长因子（VEGF）被证明在肾小球肾炎（GN）的肾小球毛细血管修复中起关键作用。我们推测其他血管生成因子同样参与肾小球毛细血管重塑，并发现血管生成素1和 -2（ANG1和ANG2）的mRNA在大鼠抗Thy1.1 GN微切割肾小球的cDNA微阵列中上调。然后我们研究了抗Thy1.1 GN病程中ANG1和ANG2及其受体Tie-2在肾小球的原位基因和蛋白表达，该疾病由注射OX-7抗体诱导。在GN诱导后第6天和第12天对动物进行灌注固定，并与接受磷酸盐缓冲液（PBS）的非肾炎对照进行比较。使用体视学技术对毛细血管损伤和修复进行定量分析。使用来自微切割肾小球的实时定量PCR、非放射性原位杂交、双重免疫荧光和蛋白质印迹分析来分析ANG1和ANG2及其受体Tie-2的基因和蛋白表达。以长度密度评估的肾小球毛细血管化在抗Thy1.1 GN第6天时显著低于对照组；在第12天恢复到正常水平。与对照组相比，疾病第6天时ANG1和ANG2基因表达明显上调。ANG1和ANG2的蛋白表达局限于足细胞，而Tie-2的蛋白表达局限于内皮细胞。在抗Thy1.1 GN第12天，当毛细血管修复几乎完成时，ANG1和ANG2基因表达恢复到基础水平，而Tie-2表达仍然很高。通过联合分子和原位方法，分析了抗Thy1.1 GN中血管生成素及其受体的时空基因和蛋白表达。结果表明，ANG1、ANG2和Tie-2在肾小球中的表达受到不同调节，可能有助于实验性GN的愈合和内皮细胞稳定。
