RESUMEN
Cerebral ischemia is a leading cause of death and long-term disability in the world. Tripartite motif-47 (Trim47), a member of the TRIM family proteins, has been reported to be involved in apoptosis and inflammation in various types of diseases. Nevertheless, the underlying molecular mechanism of Trim47 in cerebral ischemia/reperfusion (I/R) injury remains unclear. This study aimed to explore the role of Trim47 in cerebral I/R injury and the potential underlying mechanisms. The results indicated that Trim47 expression was markedly induced in rats after stroke onset. By the use of genetic approaches, we indicated that Trim47 knockdown significantly reduced the infarct size, mitigated the neurological deficits scores and decreased brain water contents in rats with cerebral I/R injury induced by middle cerebral artery occlusion (MCAO). In addition, Trim47 knockdown-alleviated cerebral I/R was correlated with the suppression of apoptosis through inhibiting Caspase-3 cleavage. Furthermore, reducing Trim47 apparently decreased the release of pro-inflammatory factors, including interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS), in brain samples of MCAO rats, which was partly by the blockage of nuclear factor-kappa B (NF-κB) signaling. However, Trim47 over-expression markedly accelerated cerebral ischemia injury through promoting apoptosis and inflammation. The suppressive effects of Trim47 knockdown on cerebral I/R were verified in human neuron-like cells stimulated by oxygen and glucose deprivation (OGD). Thus, this study demonstrated a new mechanism for the effect of Trim47 on cerebral I/R injury, and targeting Trim47 might provide feasible therapies for stroke treatment.
Asunto(s)
Apoptosis , Isquemia Encefálica/patología , Proteínas Portadoras/metabolismo , Inflamación/metabolismo , Daño por Reperfusión/patología , Accidente Cerebrovascular/patología , Proteínas de Motivos Tripartitos/fisiología , Ubiquitina-Proteína Ligasas/fisiología , Animales , Caspasa 3/metabolismo , Línea Celular Tumoral , Humanos , Infarto de la Arteria Cerebral Media , Interleucina-6/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Transducción de Señal , Proteínas de Motivos Tripartitos/genética , Ubiquitina-Proteína Ligasas/genéticaRESUMEN
Studies have extensively focused on the involvement of microRNAs (miRNAs) in cerebral ischemia/reperfusion (I/R) injury but not much on the specific role of miR-20a. Hence, this study is purposed to decipher whether miR-20a could regulate cadherin 1 (CDH1) to affect cerebral I/R injury in rats. Rat transient middle cerebral artery occlusion model (MCAO) was established. Rats were injected with lentiviral solution containing miR-20a inhibitor, or overexpressed CDH1 or combined depleted miR-20a and CDH1 to explore their roles in cerebral I/R injury. Oxidative stress-related factors, miR-20a, CDH1, nuclear factor-kappaB (NF-κB) and Nestin expression in brain tissues were detected by RT-qPCR and western blot assay. The target relation between miR-20a and CDH1 was predicted by online website and further confirmed by luciferase activity assay. In rats with cerebral I/R injury, increased miR-20a and decreased CDH1 were found in brain tissues. Reduction of miR-20a or elevation of CDH1 attenuated behavior function in MCAO rats. Inhibiting miR-20a or restoring CDH1 restrained oxidative stress, attenuated pathological damage of neurons, promoted neuron survival, and down-regulated NF-κB and Nestin expression in brain tissues of MCAO rats. CDH1 was determined to a target gene of miR-20a. This study elucidates that down-regulating miR-20a elevates CDH1 to protect neurons from cerebral I/R injury, which paves a new way for treatment of cerebral I/R injury.