Renal AAV2-Mediated Overexpression of Long Non-Coding RNA <i>H19</i> Attenuates Ischemic Acute Kidney Injury Through Sponging of microRNA-30a-5p.

Abstract

Renal ischemia-reperfusion (I/R) injury is a major cause of AKI. Noncoding RNAs are intricately involved in the pathophysiology of this form of AKI. Transcription of hypoxia-induced, long noncoding RNA <i>H19</i>, which shows high embryonic expression and is silenced in adults, is upregulated in renal I/R injury. Lentivirus-mediated overexpression, as well as antisense oligonucleotide-based silencing, modulated <i>H19 in vitro</i>. <i>In vivo</i> analyses used constitutive <i>H19</i> knockout mice. In addition, renal vein injection of adeno-associated virus 2 (AAV2) carrying <i>H19</i> caused overexpression in the kidney. Expression of <i>H19</i> in kidney transplant patients with I/R injury was investigated. <i>H19</i> is upregulated in kidney biopsies of patients with AKI, in murine ischemic kidney tissue, and in cultured and <i>ex vivo</i> sorted hypoxic endothelial cells (ECs) and tubular epithelial cells (TECs). Transcription factors hypoxia-inducible factor 1-<i>α</i>, LHX8, and SPI1 activate <i>H19</i> in ECs and TECs. <i>H19</i> overexpression promotes angiogenesis <i>in vitro</i> and <i>in vivo. In vivo</i>, transient AAV2-mediated <i>H19</i> overexpression significantly improved kidney function, reduced apoptosis, and reduced inflammation, as well as preserving capillary density and tubular epithelial integrity. Sponging of miR-30a-5p mediated the effects, which, in turn, led to target regulation of Dll4, ATG5, and Snai1. <i>H19</i> overexpression confers protection against renal injury by stimulating proangiogenic signaling. <i>H19</i> overexpression may be a promising future therapeutic option in the treatment of patients with ischemic AKI.