Inhibition of LncRNA H19 Attenuates Testicular Torsion-Induced Apoptosis and Preserves Blood-Testis Barrier Integrity

Testicular torsion is a common emergency in adolescents, and can lead to severe ischemia reperfusion injury (IRI). LncRNA H19 has been shown to increase during ischemia, but its role in testicular IRI remains unknown. Focusing on this research gap, we utilized H19 biallelic mutant mice and Sertoli cell line (TM4) to construct in vivo and in vitro models of ischemia/reperfusion (I/R) and oxygen-glucose deprivation/reperfusion (OGD/R). Compared to WT I/R mice, H19^-/- I/R mice showed milder tissue disorganization and cell loss, with a more intact blood-testis barrier (BTB). The cell viability decreased, ROS levels and apoptosis-related factors such as Bax/Bcl-2 increased in TM4 cells after OGD/R, whereas these changes were reversed when H19 was knocked down followed by OGD/R (si-H19+OGD/R). In contrast, over-expression of H19 in TM4 cells exacerbates OGD/R-induced cell apoptosis. Through in-depth analysis of KEGG-enriched pathways, the PI3K/AKT pathway was identified as a potential target of H19 modulation. Western blotting confirmed that, in OGD/R cells, elevated H19 levels were accompanied by the excessive AKT phosphorylation and the tight junction marker ZO-1 degradation; and in si-H19+OGD/R cells, the decreased AKT phosphorylation was recovered and the up-regulated ZO-1 expression was weakened simultaneously via using the AKT activator SC79. These results suggest that inhibiting H19 in OGD/R cells might preserve the integrity of the BTB by reversing the excessive phosphorylation of AKT. Moreover, H19 deficiency in si-H19+OGD/R cells alleviated the disturbances in glycolysis, fatty acid biosynthesis, and amino acid metabolism. Our study indicates that H19 might be a potential therapeutic target for clinic testicular I/R treatment.