Long non-coding RNA taurine-upregulated gene 1 (TUG1) plays pivotal roles in angiogenesis, an important mechanism of neural repair after intracerebral hemorrhage (ICH). However, the role of TUG1 in angiogenesis following ICH is not clear. Therefore, in this study, we investigated the role and the underlying mechanism of TUG1 in neurologic impairment and cerebral angiogenesis following ICH. The ICH rat model was established and then rats were injected with TUG1-expressing plasmid (pcDNA-TUG1) or miR-26a mimic, a critical regulator of VEGF-mediated angiogenesis. We confirmed the overexpression of TUG1 and miR-26a by qRT-PCR. The neurological deficits of ICH rats were evaluated by modified neurological severity scores. The expression of angiogenesis markers VEGF and CD31 were examined by immunohistochemistry and western blot. The interaction between TUG1 and miR-26a was determined by luciferase reporter assay. Our results showed that ICH caused a marked upregulation of TUG1 and a significant downregulation of miR-26a. TUG1 overexpression led to the deterioration of neurologic function and inhibited cerebral angiogenesis in ICH rats. In contrast, overexpression of miR-26a alleviated the neurologic damage and promoted cerebral angiogenesis in ICH rats, but these could be attenuated by TUG1 overexpression. Furthermore, TUG1 directly bound to miR-26a and inhibited its expression. Importantly, TUG1 overexpression inhibited the expression of VEGF by targeting miR-26a. In conclusion, our results indicated that TUG1 aggravated ICH-mediated injury by suppressing angiogenesis by downregulating miR-26a. This suggests a rationale for targeting TUG1/miR-26a in the therapy of ICH.
Keywords: Angiogenesis; intracerebral hemorrhage; miR-26a; neurological function; taurine-upregulated gene 1.
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