Transcription factor EB (TFEB) promotes autophagy in early brain injury after subarachnoid hemorrhage in rats

Background: Early brain injury (EBI) is responsible for devastating outcomes for patients with subarachnoid hemorrhage (SAH). Autophagy and Apoptosis regulate the process of cell death. The transcription factor EB (TFEB) can increase autophagic flux by promoting autophagosome formation and autophagosome-lysosome fusion, and dysregulation of TFEB activity might induce the development of several diseases. However, the biological functions of TFEB in EBI post-SAH remain unknown.

Methods: We established an animal model of SAH by modified endovascular perforation and a cellular model by treating primary cortical neurons with oxyhemoglobin (oxyHb). A recombinant adenovirus containing a shRNA targeting TFEB (adv-sh-TFEB) was used to knock down TFEB expression. Protein levels of TFEB, Bax, Bcl-2, cleaved Caspase-3, LC3, and Beclin-1 were measured by western blotting and immunofluorescence staining. Neuronal Apoptosis was assessed by flow cytometry and TUNEL staining. Short-term neurobehavioral functions were examined by modified Garcia and beam balance scores. Brain edema was determined through assessment of brain water content.

Results: TFEB was increased at the protein level in cellular and animal models of SAH. TFEB depletion attenuated the oxyHb-induced Apoptosis of primary cortical neurons and Autophagy. TFEB downregulation improved the short-term neurobehavioral functions and reduced brain edema after SAH and inhibited neuronal Apoptosis in SAH rats.

Conclusion: TFEB depletion improves short-term neurologic performance and reduces brain edema by preventing Autophagy and Apoptosis after SAH.

TFEB; apoptosis; autophagy; neurobehavioral functions; subarachnoid hemorrhage.