S REDZEPAGIC1, C. HUANG1, S. GLASTRAS1, 2, C. POLLOCK1, U. PANCHAPAKESAN1
1Renal Research Group, Kolling Institute, Royal North Shore Hospital, University of Sydney, Sydney, New South Wales; 2Department of Diabetes, Endocrinology and Metabolism, Royal North Shore Hospital, Sydney, New South Wales
Aim: To validate the role of a novel long non-coding RNA (LNCRNA) in a mouse model of diabetic kidney disease (DKD) and assess its regulation in human kidney proximal tubular cells (HK PTCs) exposed to high glucose (HG) and transforming growth factor beta (TGFb1).
Background: The incidence of DKD is increasing globally, and current treatment options are limited. Exploration of the role of LNCRNA in DKD may lead to new therapeutic targets.
Methods: RNA sequencing and bioinformatics was utilised to compare renal LNCRNA expression in two C57Bl/6 mouse models of DKD, namely streptozotocin (STZ)-induced diabetes and high-fat diet (HFD)-induced diabetes, versus non-diabetic controls. LNCRNAs differentially expressed in diabetic kidney compared to control were then analysed for relevance to DKD rather than metabolic dysregulation. These LNCRNAs were then validated by performing RT-PCR on diabetic mouse kidney and HK2PTCs exposed to HG and TGFb1.
Results: RNA sequencing identified upregulation of four novel LNCRNAs (log FC>1, P<0.05) common to both models and relevant to DKD. RT-PCR confirmed only one (LNCRNA#1) to be consistently expressed across human and mouse kidney; the LNCRNA#1 PCR product was similar and there was conservation and synteny with flanking genes.
Renal expression of LNCRNA#1 was upregulated in the STZ model of DKD versus control (P<0.005); though not in HFD-induced DKD (P=0.78).
In HK2 cells, LNCRNA#1 was upregulated by TGFb1 (P=0.05), though to a lesser extent by HG (P=0.06) at 48h.
Conclusions: LNCRNA#1 was identified as a potential target in DKD by its upregulation in an established mouse model of DKD and in TGFb1-exposed human PTCs. Sequence specific LNA GapmeR (Exiqon) will be used to further elucidate the functional relevance of this target in DKD.