Novel targets of antifibrotic and anti-inflammatory treatment in CKD

Abstract

Chronic kidney disease (CKD) is becoming a worldwide epidemic, driven largely by the dramatic rise in the prevalence of diabetes and obesity. Novel targets and treatments for CKD are, therefore, desperately needed-to both mitigate the burden of this disease in the general population and reduce the necessity for renal replacement therapy in individual patients. This Review highlights new insights into the mechanisms that contribute to CKD, and approaches that might facilitate the development of disease-arresting therapies for CKD. Particular focus is given to therapeutic approaches using antifibrotic agents that target the transforming growth factor β superfamily. In addition, we discuss new insights regarding the roles of vascular calcification, the NADPH oxidase family, and inflammation in the pathogenesis of CKD. We also highlight a new understanding regarding kidney energy sensing pathways (AMPK, sirtuins, and mTOR) in a variety of kidney diseases and how they are linked to inflammation and fibrosis. Finally, exciting new insights have been made into the role of mitochondrial function and mitochondrial biogenesis in relation to progressive kidney disease. Prospective therapeutics based on these findings will hopefully renew hope for clinicians and patients in the near future.

Figure 1

Specific targets and potential therapeutic strategies to inhibit or slow the progression of CKD. There is a complex feed-forward relationship between the initiating factors (hyperglycaemia, obesity, hypertension, bone and mineral disorders) and cardiovascular disorders that stimulate and regulate a variety of major pathways leading to CKD and its complications. Inhibiting intrinsic renal pathways linked to inflammation (NADPH oxidase) and fibrosis (Smads, TGF-β, and CTGF) might prove beneficial. A possible central pathway would be the activation of AMPK that can reduce both inflammatory and profibrotic pathways. Abbreviations: AICAR, AMP analogue; AMPK, 5’-AMP-activated protein kinase; BMP-7, bone morphogenetic protein 7; CKD, chronic kidney disease; CTGF, connective tissue growth factor; EMT, epithelial–mesenchymal transition; HGF, hepatocyte growth factor; NF, nuclear factor; NOX, NADPH oxidase; R, receptor; ROS, reactive oxygen species; Smad, mothers against decapentaplegic homologue; TGF-β, transforming growth factor β; USF, upstream stimulatory factor.