The role of the lncRNA MIR3142HG in kidney disease-associated endothelial injury

• Applicant: Dr. Andreas Dieter Zietzer
• Subject Area: Nephrology ; Cardiology, Angiology ; Cell Biology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 514976099

Chronic kidney disease is a major risk factor for the development of cardiovascular disease. Uremic toxins, such as indoyxlsulfate (IS), mediate inflammation and endothelial dysfunction, but so far, the underlying molecular mechanisms of how IS impairs endothelial regeneration are not fully understood. Recent research has identified long-non-coding RNAs (lncRNA) to be important mediators of cardiovascular disease development. Our preliminary data show that IS causes a pro-inflammatory activation of the endothelium and impairs endothelial regeneration. By use of total RNA sequencing, we have identified three lncRNAs that are highly expressed and significantly dysregulated after IS injury of endothelial cells. Among these RNAs, MIR3142HG is until now almost completely uncharacterized especially with regard to its biological function. As lncRNAs often exert their biological function through the binding of other RNAs and proteins, the first aim of this study is to characterize the interactome of MIR3142HG. To this end, we will isolate MIR3142HG from endothelial cells via a pulldown experiment and perform proteomic analysis as well as RNA sequencing from those isolates. Furthermore, we have started to perform loss-of-function experiments for MIR3142HG by transfecting an LNA Gapmer to elucidate its biological role in IS-treated endothelial cells. An additional aim will be to identify the factors that mediate the upregulation of MIR3142HG after IS injury. A number of the cellular effects seen from IS treatment are mediated by organic anion transporting polypeptides (OATPs). We have identified OATP2A to be the most abundant OATP in endothelial cells and to be highly regulated upon IS injury. Loss-of-function experiments of OATP2A will be performed to elucidate its role in IS-mediated endothelial injury and the upregulation of MIR3142HG. As next step, we aim to investigate the distribution and the role of MIR3142HG in human blood. Like many other lncRNAs, MIR3142HG is not well conserved and no homologues have been identified in mice. Preliminary data show that MIR3142HG is present in human blood, and therein found in large and small extracellular vesicles. In a pilot cohort, we found that the total blood levels of MIR3142HG are inversely correlated with kidney function. We plan to extend this cohort to > 200 patients and to include cardiovascular outcomes after two years, in order to examine the association between MIR3142HG and cardiovascular disease in humans. Furthermore, ex vivo experiments will be performed with human plasma and extracellular vesicles to investigate the biological effect of circulating MIR3142HG on endothelial-cell regeneration. The overall aim of this application is to identify novel molecular mechanisms that mediate cardiovascular-disease development in patients with chronic kidney disease. MIR3142HG is a promising candidate for this aim, and the biological role and function will be investigated in depth through this proposal.

• DFG Programme: Research Grants
• Co-Investigator: Privatdozent Dr. Felix Jansen