Silencing of lncRNA XIST impairs angiogenesis and exacerbates cerebral vascular injury after ischemic stroke

Abstract

The aim of this study was to investigate the function and regulatory mechanism of long non-coding RNA (lncRNA) X-inactive-specific transcript (XIST) in cerebral ischemic stroke (CIS). The impact of lncRNA XIST on CIS was evaluated in acute CIS patients, middle cerebral artery occlusion (MCAO) mice, and oxygen-glucose deprivation and restoration brain endothelial cells. Our results demonstrated that the expression of lncRNA XIST decreased during the early stages of CIS but then increased in the later stages in CIS patients and ischemic models in vivo and in vitro. In addition, the serum levels of lncRNA XIST negatively correlated with severity of neurological impairment of CIS patients. Further studies exhibited that lncRNA XIST regulated the expression of proangiogenic factor-integrin a5 (Itga5) and anti-inflammation factor-Kruppel-like transcription factor 4 (KLF4) by targeting microRNA-92a (miR-92a). Silencing of lncRNA XIST impaired angiogenesis and exacerbated cerebral vascular injury following CIS, leading to larger infarcts and worse neurological deficits in transient MCAO mice. Mechanistic analysis revealed that lncRNA XIST modulated angiogenesis and alleviated cerebral vascular injury following CIS through mediating the miR-92a/Itga5 or KLF4 axis, respectively. These data indicate that lncRNA XIST confers protection against CIS, providing a valuable target for future prevention and treatment of CIS.

Non-coding RNAs in the regulation of blood–brain barrier functions in central nervous system disorders

“…In ischemic stroke, lncRNA XIST has been proposed to be a potential biomarker for predicting the prognosis of acute cerebral ischemia and a therapeutic target for stroke patients. LncRNA XIST exhibited increased expression during the late stages (seven days later) after the onset of ischemic stroke, and the serum levels of lncRNA XIST were significantly negatively correlated with the severity of neurological impairments in the ischemic stroke patients [ 61 ]. Silencing of lncRNA XIST significantly impaired angiogenesis by decreasing the endothelial migration and tube formation, exacerbated cerebral vascular injury by markedly reducing the expressions of KLF4 and tight junction proteins claudin-5 and ZO-1, and evidently increased the vascular permeability by upregulating the expression of E-selectin, vascular cell adhesion protein 1 (VCAM-1), ICAM-1, and p-NF-kB [ 61 ].…”

“…LncRNA XIST exhibited increased expression during the late stages (seven days later) after the onset of ischemic stroke, and the serum levels of lncRNA XIST were significantly negatively correlated with the severity of neurological impairments in the ischemic stroke patients [ 61 ]. Silencing of lncRNA XIST significantly impaired angiogenesis by decreasing the endothelial migration and tube formation, exacerbated cerebral vascular injury by markedly reducing the expressions of KLF4 and tight junction proteins claudin-5 and ZO-1, and evidently increased the vascular permeability by upregulating the expression of E-selectin, vascular cell adhesion protein 1 (VCAM-1), ICAM-1, and p-NF-kB [ 61 ]. Another lncRNA, named lncRNA associated with breast cancer brain metastasis (BCBM) (Lnc-BM), has also been suggested as a prognostic biomarker of the progression of brain metastasis in breast cancer patients [ 62 ].…”

“…Recent studies also demonstrated the functional roles of lncRNAs in the regulation of the BBB permeability and neurological recovery in ischemic stroke. Among these differentially expressed lncRNAs in ischemic stroke, lncRNA metastasis-associated lung adenocarcinoma transcript 1 (Malat1) [ 95 – 97 ], LOC102640519 [ 98 ], and maternally expressed gene 3 (MEG3) [ 99 ] exhibit increased expression, and lncRNA small nucleolar RNA host gene 8 (Snhg8) [ 100 ] and X-inactive-specific transcript (XIST) [ 61 ] exhibit decreased expression in brain microvascular endothelial cell (BMEC) cultures, astrocytes, or ischemic brain tissues under hypoxia or cerebral ischemia in mice (Fig. 1 ).…”

“…Further investigation suggested that lncRNA Malat1 could positively regulate the expression of aquaporin-4 (AQP4) by competitively binding miR-145 to mediate the damage of astrocytes during ischemic stroke [ 97 ]. LncRNA XIST was found to exhibit decreased serum levels during the early stages of ischemic stroke patients, and silencing lncRNA XIST significantly decreased the endothelial migration and tube formation, and exacerbated cerebral vascular injury by notably reducing the expressions of krüppel-like factor 4 (KLF4) and tight junction proteins claudin-5 and ZO-1, leading to larger infarction and worse neurological functions in transient ischemic stroke mice [ 61 ].…”

Long Non Coding RNA Based Regulation of Cerebrovascular Endothelium

“…Xist acts as a sponge for miR-92a , which in turn regulates levels of integrin-α5 and KLF4. KLF4 overexpression can reduce levels of E-selectin, VCAM-1, ICAM-1 and p- NFκB ( Wang C. et al, 2021 ).…”