DRAM1 protects neuroblastoma cells from oxygen-glucose deprivation/reperfusion-induced injury via autophagy.

DNA damage-regulated autophagy modulator protein 1 (DRAM1), a multi-pass membrane lysosomal protein, is reportedly a tumor protein p53 (TP53) target gene involved in autophagy. During cerebral ischemia/reperfusion (I/R) injury, DRAM1 protein expression is increased, and autophagy is activated. However, the functional significance of DRAM1 and the relationship between DRAM1 and autophagy in brain I/R remains uncertain. The aim of this study is to investigate whether DRAM1 mediates autophagy activation in cerebral I/R injury and to explore its possible effects and mechanisms. We adopt the oxygen-glucose deprivation and reperfusion (OGD/R) Neuro-2a cell model to mimic cerebral I/R conditions in vitro, and RNA interference is used to knock down DRAM1 expression in this model. Cell viability assay is performed using the LIVE/DEAD viability/cytotoxicity kit. Cell phenotypic changes are analyzed through Western blot assays. Autophagy flux is monitored through the tandem red fluorescent protein-Green fluorescent protein-microtubule associated protein 1 light chain 3 (RFP-GFP-LC3) construct. The expression levels of DRAM1 and microtubule associated protein 1 light chain 3II/I (LC3II/I) are strongly up-regulated in Neuro-2a cells after OGD/R treatment and peaked at the 12 h reperfusion time point. The autophagy-specific inhibitor 3-Methyladenine (3-MA) inhibits the expression of DRAM1 and LC3II/I and exacerbates OGD/R-induced cell injury. Furthermore, DRAM1 knockdown aggravates OGD/R-induced cell injury and significantly blocks autophagy through decreasing autophagosome-lysosome fusion. In conclusion, our data demonstrate that DRAM1 knockdown in Neuro-2a cells inhibits autophagy by blocking autophagosome-lysosome fusion and exacerbated OGD/R-induced cell injury. Thus, DRAM1 might constitute a new therapeutic target for I/R diseases.

Efficacy and safety of stenting for elderly patients with severe and symptomatic carotid artery stenosis: a critical meta-analysis of randomized controlled trials.

OBJECTIVE: To investigate both short-term and long-term therapeutic efficacy and safety of carotid artery stenting (CAS) and carotid artery endarterectomy (CEA) for elderly patients with severe and symptomatic carotid artery stenosis. METHODS: PubMed, EMBASE, Cochrane Library, Clinical Trials Register Centers, and Google Scholar were comprehensively searched. After identifying relevant randomized controlled trials, methodological quality was assessed by using Cochrane tools of bias assessment. Meta-analysis was performed by RevMan software, and subgroup analyses according to different follow-up periods were also conducted. RESULTS: Sixteen articles of nine randomized controlled trials containing 6,984 patients were included. Compared with CEA, CAS was associated with high risks of stroke during periprocedural 30 days (risk ratio [RR]=1.47, 95% confidence interval [CI]: 1.15-1.88), 48 months (RR=1.37, 95% CI: 1.11-1.70), and >48 months (RR=1.76, 95% CI: 1.34-2.31). There was no significant difference in the aspects of death, disabling stroke, or death at any time between the groups. For other periprocedural complications, CAS decreased the risk of myocardial infarction (RR=0.44, 95% CI: 0.26-0.75), cranial nerve palsy (RR=0.09, 95% CI: 0.04-0.22) and hematoma (RR=0.31, 95% CI: 0.14-0.68) compared with CEA, while it increased the risk of bradycardia or hypotension (RR=8.45, 95% CI 2.91-24.58). CONCLUSION: Compared with CEA, CAS reduced hematoma, periprocedural myocardial infarction, and cranial nerve palsy, while it was associated with higher risks of both short-term and long-term nondisabling stroke. And they seemed to be equivalent in other outcome measures. As regards to its minimal invasion, it should be applied only in specific patients.