Deubiquitylating enzyme OTUB1 facilitates neuronal survival after intracerebral hemorrhage via inhibiting NF-κB-triggered apoptotic cascades

Abstract

The deubiquitylase OTU domain-containing ubiquitin aldehyde-binding protein 1 (OTUB1) has been implicated in the pathogenesis of various human diseases. However, the molecular mechanism by which OTUB1 participates in the pathogenesis of intracerebral hemorrhage (ICH) remains elusive. In the present study, we established an autologous whole blood fusion-induced ICH model in C57BL/6J mice. We showed that the upregulation of OTUB1 contributes to the attenuation of Nuclear factor kappa B (NF-κB) signaling and its downstream apoptotic signaling after ICH. OTUB1 directly associates with NF-κB precursors p105 and p100 after ICH, leading to attenuated polyubiquitylation of p105 and p100. Moreover, we revealed that NF-κB signaling was modestly activated both in ICH tissues and hemin-exposed HT-22 neuronal cells, accompanied with the activation of NF-κB downstream pro-apoptotic signaling. Notably, overexpression of OTUB1 strongly inhibited hemin-induced NF-κB activation, whereas interference of OTUB1 led to the opposite effect. Finally, we revealed that lentiviral transduction of OTUB1 markedly ameliorated hemin-induced apoptotic signaling and HT-22 neuronal death. Collectively, these findings suggest that the upregulation of OTUB1 serves as a neuroprotective mechanism in antagonizing neuroinflammation-induced NF-κB signaling and neuronal death, shed new light on manipulating intracellular deubiquitylating pathways as novel interventive approaches against ICH-induced secondary neuronal damage and death.