Pathogenic and protective role of macrophages in kidney disease

Abstract

Macrophages (MΦ) are located throughout kidney tissue, where they play important roles in homeostasis, surveillance, tolerance, and cytoprotection. MΦ are highly heterogeneous cells and exhibit distinct phenotypic and functional characteristics depending on their microenvironment and the disease type and stage. Recent studies have identified a dual role for MΦ in several murine models of kidney disease. In this review, we discuss the pathogenic and protective roles of the various MΦ subsets in experimental and human kidney diseases and summarize current progress toward the therapeutic use of MΦ in kidney diseases.

Keywords: cell therapy; kidney disease; macrophages.

Fig. 1.

Macrophage phenotype and function are critical determinants of kidney injury or repair. In response to ongoing injury, activated pro-inflammatory macrophages (M1) secrete pathogenic factors that induce kidney injury and fibrosis by promoting inflammation and tubular cell apoptosis. In certain microenvironments, anti-inflammatory macrophages (M2) secrete regenerative trophic factors that reduce inflammation, promote cell proliferation, and stimulate angiogenesis, which leads to wound healing and renal recovery. It is unclear whether M2 contribute to kidney fibrosis.