Targeting inflammatory pathways as a novel treatment for diabetic kidney disease.

Diabetic kidney disease is an important complication of diabetes and remains a huge medical burden and a major contributor of morbidity and mortality in patients with diabetes. Inflammation is recognised as a key contributor to diabetic complications, including both macrovascular complications such as atherosclerosis as well as in microvascular complications such as diabetic kidney disease. These complications often cluster in individual patients with diabetes. In the diabetic context, a number of pathological processes occur including chronic low-grade inflammation, oxidative stress, as well as increased synthesis and accumulation of extracellular matrix proteins, leading to fibrosis. These processes are largely driven by the regulation of key growth factors and cytokines such as TGFβ and TNFα which are elevated in diabetes. The direct targeting of such molecules as a potential treatment for diabetic kidney disease is problematic as these factors are involved in a number of important physiological responses including immune regulation, inflammation and cell survival. Recent work from our group and others has identified a novel "pro-resolution" pathway by which the body regulates the inflammation in response to injury. Our studies have demonstrated that an endogenous family of molecules known as “Lipoxins" can reduce inflammation via a number of pathways, including specific effects on the recruitment of macrophages to the diabetic kidney, and thus prevent damage occurring in the kidney as a result of diabetes. The use of these molecules and examining their effects on macrophages forms the basis of this study. Project: Pro-resolution therapy targeting chronic low-grade inflammatory signalling as a novel treatment for diabetic kidney disease. This project will involve the of the streptozotocin (STZ)-induced diabetic ApoE-/- mice which not only develop atherosclerosis (see other project), but also prominent diabetic kidney disease. These mice will be crossed with the FPR2 KO mice. FPR2 is the receptor to which Lipoxins bind and bias the receptor towards anti-inflammatory signalling. In addition, ApoE KO mice in which the receptor has been specifically deleted in myeloid cells will also be used to determine whether the protective effects of Lipoxins are via direct binding to macrophages, or to other cell populations as well. The focus will be on designing experiments to better understand how Lipoxin A4 dampens the pathological signalling that occurs in through inflammatory pathways in diabetes and specifically the target cells by which Lipoxins work. Kidneys will be collected from control and diabetic mice, with or without Lipoxin A4 treatment and analysed for gene expression. Experiments will include structural and functional analyses of the kidney, gene expression analysis by RT-qPCR, analysis for oxidative stress, markers of inflammation and fibrosis, and immunohistochemistry. There is an opportunity to perform some single-cell RNA-seq analysis depending on progress. In vitro methods will include a variety of tissue culture techniques in renal cell populations to dissect the molecular pathways involved. Methods include RT-qPCR, western blot and in-cell westerns, ELISA, immunofluorescence, transfections and reporter assays. Techniques to be used include animal experiments, cell biology, molecular techniques and RNA-seq. A Top Up Scholarship may be available to selective students.