Ccl2/Mcp-1 blockade reduces glomerular and interstitial macrophages but does not ameliorate renal pathology in collagen4A3-deficient mice with autosomal recessive Alport nephropathy
JOURNAL OF PATHOLOGY
Authors: Clauss, Sebastian; Gross, Oliver; Kulkarni, Onkar; Avila-Ferrufino, Alejandro; Radomska, Ewa; Segerer, Stephan; Eulberg, Dirk; Klussmann, Sven; Anders, Hans-Joachim
Abstract
Lack of the alpha 3 or alpha 4 chain of type IV collagen (COL4) causes autosomal recessive Alport nephropathy in humans and mice that is characterized by progressive glomerulosclerosis and tubulointerstitial disease. Renal pathology is associated with chemokine-mediated macrophage infiltrates but their contribution to the progression of Alport nephropathy is unclear. We found Ccl2 to be expressed in increasing amounts during the progression of nephropathy in Col4a3-deficient mice; hence, we blocked Ccl2 with anti-Ccl2 Spiegelmers, biostable L-enantiomeric RNA aptamers suitable for in vivo applications. Ccl2 blockade reduced the recruitment of ex vivo-labelled macrophages into kidneys of Col4a3-deficient mice. We therefore hypothesized that a prolonged course of Ccl2 blockade would reduce renal macrophage counts and prevent renal pathology in Col4a3-deficient mice. Groups of Col4a3-deficient mice received subcutaneous injections of either an anti-mCcl2 Spiegelmer or non-functional control Spiegelmer on alternate days, starting from day 21 or 42 of age. Glomerular and interstitial macrophage counts were found to be reduced with Ccl2 blockade by 50% and 30%, respectively. However, this was not associated with an improvement of glomerular pathology, interstitial pathology, or of overall survival of Col4a3-deficient mice. We conclude that Ccl2 mediates the recruitment of glomerular and interstitial macrophages but this mechanism does not contribute to the progression of Alport nephropathy in Col4a3-deficient mice. Copyright (C) 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
MicroRNA-410-5p exacerbates high-fat diet-induced cardiac remodeling in mice in an endocrine fashion
SCIENTIFIC REPORTS
Authors: Zou, Tong; Zhu, Mei; Ma, Yi-Cheng; Xiao, Fei; Yu, Xue; Xu, Li; Ma, Lan-Qing; Yang, Jiefu; Dong, Jian-Zeng
Abstract
Metabolic disorders, such as obesity and type 2 diabetes, are associated with an increased risk of cardiomyopathy. To date, microRNA (miRNAs) functions in cardiac remodeling induced by obesity remain to be elucidated. We found that rats fed a high fat diet (HFD) manifested cardiac fibrosis and LV dysfunction. In the heart of rats fed HFD, the phosphorylation levels of Smad 2 and the expression of fibrotic genes, such as connective tissue growth factor, collagen-1 alpha 1 (Col1 alpha 1), Col3 alpha 1, and Col4 alpha 1, were up-regulated, which accompanied by an increase in Smad 7 protein levels, but not its mRNA levels. Using miRNA microarray analysis, we showed that the miRNA miR-410-5p inhibited the protein expression of Smad 7, thus increasing the phosphorylation levels of Smad 2. Overexpression of miR410-5p promoted cardiac fibrosis in rats fed normal diet, whereas inhibition of miR-410-5p by way of miR-410-5p antimiR suppressed cardiac fibrosis in rats fed HFD. Finally, our data revealed that miR410-5p from the kidney and adipose tissues was probably transferred to heart to induce cardiac fibrosis. Taken together, our study characterizes an endocrine mechanism in which adipose-or kidney-derived circulating miR-410-5p regulates metabolic disorders-mediated cardiac remodeling by activating the TGF beta/Smad signaling in heart.