Diabetic Nephropathy

The Effect of Differentially Expressed Genes on the Progression of Diabetic Nephropathy
Keywords: diabetic nephropathy, type 2 diabetes
My primary research interest is to understand how the body responds to damage caused by diet-induced obesity and diabetes, a prominent public health concern in contemporary society. Diabetic nephropathy (DN) is a chronic disorder that leads to irreparable damage in the kidney. Approximately 30-40% of diabetic patients will eventually develop DN, and 5% of type II diabetics already have kidney disease at the time of diagnosis 1 . In fact, in the United States, DN is the leading cause of end stage renal disease (ESRD, which requires renal dialysis or renal transplant), as 50% of patients are diabetic 2, 3 .

Our laboratory is approaching this problem by identifying genes that are differentially expressed (DEX genes) in the kidney in a high fat diet-induced type II diabetes model. This model has been shown to replicate the clinical features of DN 4 . In a previous study (publication in preparation), we used an RNAseq screen followed by real-time PCR (RT-PCR) confirmation to identify 20 highly differentiated genes in the kidney cortex in DN mice. As 17 of the 20 genes have never before been studied in the prospect of their relationship to DN, we are interested in uncovering the role these DEX genes play in the onset and progression of the disease. Studying these genes is an important step towards developing novel therapies and uncovering potential early stage diagnostic biomarkers for this injurious disease, leading to improved health outcomes for thousands of affected people. The objective of this proposal is to further our understanding of the genes involved in the onset and progression of diabetic nephropathy. Specifically, we will: 1) determine how expression of three key DEX genes

Using knockout mouse models and transgenic animals that overexpress a gene, we will determine how the condition of DN mice differs from wild-type (WT) DN mice at each time point as a result of the loss or overexpression of one of our genes of interest. This aim may elucidate whether a gene contributes to the progression of DN, or if it is altered as a result of DN. The transgenic mouse facility at Johns Hopkins has expertise with the CRISPR system, and has successfully performed CRISPR-mediated insertion of flox sites. We will use this method to create kidney-specific knockouts with our gene of interest under the control of a kidney-specific promoter (ksp-cre). We will select a single candidate gene to study in this aim based on changes observed in SA1. If our selected gene is upregulated in the disease state, which is the case for sorcs1 and synpr, we will generate kidney-specific KO mice. On the contrary, gsta2 is downregulated in the kidney during DN, so we would overexpress this gene in DN kidneys and observe changes in disease state. If the changes in gene expression that we observed contribute to pathology, we expect to observe a less severe disease state (defined below) at each time point in transgenic animals. If the changes in gene expression are protective against this disease, we expect the disease state to be more severe at each time