Abstract: SA-PO321

Elucidation of the Gene Regulatory Networks That Control Diabetes-Induced Kidney Damage

Session Information

Category: Chronic Kidney Disease (Non-Dialysis)

  • 308 CKD: Mechanisms of Tubulointerstitial Fibrosis

Authors

  • Wang, Bo, Monash University, Melbourne, New South Wales, Australia
  • Naeem, Haroon, Monash University, Melbourne, New South Wales, Australia
  • Ji, Guanyu, E-gene co.ltd, ShenZhen, China
  • Kantharidis, Phillip, Monash University, Melbourne, New South Wales, Australia
  • Ricardo, Sharon D., Monash University, Melbourne, New South Wales, Australia
Background

Diabetes mellitus is an epidemic of the 21st century and is now the leading cause of chronic kidney disease (CKD) that results in the development of fibrosis. TGF-b1 is of the major drivers in the progression of diabetic nephropathy We use advanced next-generation sequencing (NGS) technology to identify genomic sequences and signatures unique to TGF-b1 to provide a global approach for interrogating TGF-β1-induced kidney damage. The discovery of new therapeutic targets was coupled with complementary functional analyses to identify and validate novel regulators of kidney injury and fibrosis.

Methods

Mesangial cells were treated with TGF-β1 at 10ng/ml for 72 hours, followed by NGS to determine miRNA, mRNA, DNA methylation and H3K27me3 levels. Integrative and complementary functional analyses were employed to identify potential regulators and qPCR and luciferase assay used for validation.

Results

A genetic and epigenetic library as established and includes miRNA, RNA, DNA methylation and histone (H3K27me3) modification. Our data showed that the hyper-methylation of DNA methylation was induced by TGF-β1. H3K27me3 expression was inhibited by TGF-β1 treatment together with the regulation of NRARP and TnxB identified as new targets in the development of fibrosis. The negative and positive expression pattern of miRNA and mRNA were quantified in response to TGF-β1. A novel regulator, miR-378, was also found to be a pivotal regulator of the TGF-β/Smad pathway, confirmed using NRK52E cells co-transfected with the SMAD3 CAGA reporter and miR-378 in the presence of TGF-β1 for 3 days of culture and STZ-induced diabetic kidney samples. Moreover, miR-378 was found to regulate MAPK signalling through repression of the MAPK1 pathway.

Conclusion

TGF-b1 mediates genetic and epigenetic interactions in kidney mesangial cells within a complicated network of gene expression and DNA modification. DNA methylation and H3K27me3 modification were found to be involved in TGF-β1 regulated pathogenesis of mesangial cells. We established a multi-omics library to demonstrate the gene expression regulated by miRNA and epigenetic changes. We report a protective regulator of miR-378 through mediating MAPK pathway, in the downstream induction of kidney cell fibrosis and mesangial hypertrophy. Moreover, H3K27me3 was indicated as a novel regulator using NGS technology.

Funding

  • Government Support - Non-U.S.