Long non-coding RNA ZFAS1 exerts a protective role to alleviate oxygen and glucose deprivation-mediated injury in ischemic stroke cell model through targeting miR-186-5p/MCL1 axis

Pathophysiology of Ischemic Stroke: Noncoding RNA Role in Oxidative Stress

Stroke is a neurological disease that causes significant disability and death worldwide. Ischemic stroke accounts for 75% of all strokes. The pathophysiological processes underlying ischemic stroke include oxidative stress, the toxicity of excitatory amino acids, ion disorder, enhanced apoptosis, and inflammation. Noncoding RNAs (ncRNAs) may have a vital role in regulating the pathophysiological processes of ischemic stroke, as confirmed by the altered expression of ncRNAs in blood samples from acute ischemic stroke patients, animal models, and oxygen-glucose-deprived (OGD) cell models. Due to specific changes in expression, ncRNAs can potentially be biomarkers for the diagnosis, treatment, and prognosis of ischemic stroke. As an important brain cell component, glial cells mediate the occurrence and progression of oxidative stress after ischemic stroke, and ncRNAs are an irreplaceable part of this mechanism. This review highlights the impact of ncRNAs in the oxidative stress process of ischemic stroke. It focuses on specific ncRNAs that underlie the pathophysiology of ischemic stroke and have potential as diagnostic biomarkers and therapeutic targets.

The protective effects of lncRNA ZFAS1/miR-421-3p/MEF2C axis on cerebral ischemia-reperfusion injury

LncRNA ZNFX1 antisense RNA 1 (ZFAS1) could improve neuronal damage and inhibit inflammation and apoptosis. We conducted an in-depth exploration on the protective mechanism of ZFAS1 in cerebral ischemia-reperfusion injury. Overexpressed or silenced plasmids of ZFAS1 were transfected into the cells to analyze the effects of oxygen-glucose deprivation/reperfusion (OGD/R) treatment on the viability, apoptosis and related gene expressions of Neuro-2a cell by performing MTT assay, flow cytometry, qRT-PCR, and Western blot. Bioinformatic analysis, qRT-PCR, dual-luciferase reporter assay and RNA immunoprecipitation were used to screen and verify the miRNA(s) which could competitively bind with ZFAS1 and downstream mRNA(s) targeted by the miRNA(s). The effects of ZFAS1 and the above target miRNA(s) or gene(s) on the apoptosis of OGD/R-injured cells, apoptosis-related proteins, inflammatory factors and p65/IκBα pathway were further verified via the rescue test. The results from the middle cerebral artery occlusion (MCAO) mouse model in vivo were consistent with those from the cellular experiments. The expression of lncRNA ZFAS1 in OGD/R-injured cells was inhibited, and the up-regulation of ZFAS1 protected Neuro-2a cells. MiR-421-3p was predicted to be the target miRNA of ZFAS1 and could offset the protective effect of ZFAS1 overexpression on OGD/R-injured cells following its up-regulation. MEF2C, which was the downstream target gene of miR-421-3p, reversed the OGD/R-induced enhanced cell damage caused by miR-421-3p mimic when MEF2C was overexpressed. In in vivo studies, ZFAS1 overexpression reduced brain tissue infarction, apoptosis and gene regulation caused by MCAO, while miR-421-3p mimic had the opposite effect. Collectively, the regulation of lncRNA ZFAS1/miR-421-3p/MEF2C axis showed protective effects on cerebral ischemia-reperfusion injury.

The role of blood lnc-ZFAS1 in acute ischemic stroke: correlation with neurological impairment, inflammation, and survival profiles

Background

Long non‐coding RNA zinc finger antisense 1 (lnc‐ZFAS1) has been reported to inhibit neuronal damage in acute ischemic stroke (AIS). However, the role of lnc‐ZFAS1 in AIS patients remains unclear. Therefore, we assessed the relationship of lnc‐ZFAS1 with neurological impairment, inflammation, and prognosis in AIS patients.

Methods

Totally, 241 AIS patients and 120 controls were enrolled. lnc‐ZFAS1 in peripheral blood mononuclear cells was evaluated using reverse transcription‐quantitative polymerase chain reaction. Besides, a 3‐year follow‐up was conducted to assess recurrence‐free survival (RFS) and overall survival (OS) in AIS patients.

Results

lnc‐ZFAS1 was reduced in AIS patients compared to that in controls (Z = −10.693, p < 0.001). In AIS patients, lnc‐ZFAS1 was negatively correlated with National Institutes of Health Stroke Scale score (r_s = −0.335, p < 0.001), C‐reactive protein (r_s = −0.284, p < 0.001), tumor necrosis factor‐alpha (r_s = −0.293, p < 0.001), interleukin‐1β (r_s = −0.149, p = 0.021), and interleukin‐6 (r_s = −0.161, p = 0.012), but not underlying diseases (all p > 0.05). Besides, lnc‐ZFAS1 was divided into high and low levels based on the median expression in AIS patients. Indeed, high lnc‐ZFAS1 predicted better RFS (χ² = 6.222, p = 0.013); the 1‐year, 2‐year, and 3‐year RFS rates were 94.2%, 88.3%, and 85.5%, respectively, in patients with high lnc‐ZFAS1, then 87.5%, 79.2%, and 71.6%, respectively, in those with low lnc‐ZFAS1. However, lnc‐ZFAS1 was not correlated with OS (χ² = 1.404, p = 0.236); the 1‐year, 2‐year, and 3‐year OS rates were 98.3%, 95.8%, and 94.0%, respectively, in patients with high lnc‐ZFAS1, then 96.7%, 93.9%, and 89.6%, respectively, in those with low lnc‐ZFAS1.

Conclusion

Lower lnc‐ZFAS1 expression is connected with increased neurological impairment and inflammation as well as worse RFS in AIS patients.