In this study we reported for the first time the down-regulation of lncRNAs ANRIL and MIAT in 50 CVT patients relative to controls. Moreover, two lncRNAs (ANRIL and MIAT) were identified as potential markers for CVT diagnosis with an AUC of 0.98 and 0.99, respectively for CVT. In our study, there was no significant association between ANRIL expressions with demographic and CVT risk factors in our patients. Unfortunately, data for identifying CVT severity with the modified Rankin Scale (mRS) were overlooked for many patients. Therefore, we could not estimate the genetic correlation between gene expressions with CVT severity to determine the inflammatory or anti-inflammatory effects of ANRIL and MIAT expression after CVT. According to previous reports, ANRIL gene polymorphisms associate to the IS risk and play a critical role in IS pathogenesis [19]. Moreover, ANRIL rs10965215 showed a good diagnostic accuracy for IS [20]. Also, several studies have identified the potential use of ANRIL as diagnostic biomarker for other disease such as Stroke[21, 22], CHD[23, 24], CAD[25, 26], Cancer[27, 28].
ANRIL overexpression is associated with inflammatory response in IS[29], The possible mechanism involved in pro-inflammatory effect of ANRIL include; increase in NF‑κB expression [30], type I interferon‑mediated signal transduction pathway and innate immune response [31]. On the other hand, the ANRIL downregulation with anti-inflammatory effects has been suggested in inflammatory bowel disease (IBD) [32], attenuating the atherosclerosis progression in CAD patients[8] ,and acute ischemic stroke[33]. Additionally, the association of ANRIL expression on endothelial dysfunction and promotion of thrombosis [34, 35] can represent the possible diagnostic potential of ANRIL for CVT.
We also found significant MIAT down-regulation in CVT patients compared to controls. Moreover, MIAT level in our patients with positive sex-specific risk factor was significantly higher relative to patients with negative sex-specific. Data from several sources have identified the positive association between sex- specific risk factors and CVT severity[36, 37], These results indicated that the possible inflammatory role of ANRIL on CVT.
Previous results confirmed the inflammatory effect of MIAT up-regulation with a positive correlation with disease severity in IS [38, 39], coronary artery disease [40], multiple sclerosis [41], and cancer [42]. The inflammatory mechanisms of MIAT has been suggested to participate in endothelial inflammation, vascular dysfunction [43], vascular leakage and upregulation of IL-1β and IL-6 [44]. However, Wang et al. in 2022 reported an anti-inflammatory effect of lncRNA MIAT in macrophages in synovium and myocardial tissues of collagen-induced arthritis mice [45].
We analyzed the circulating ANRIL and MIAT expression in CVT patients to identify a novel biomarker for CVT. Our results showed that circulating lncRNAs ANRIL and MIAT could be considered CVT biomarkers with an AUC score of 0.98 and 0.99, respectively, with the corresponding high sensitivity and specificity. This pilot study with 50 patients and 100 controls well demonstrated ANRIL and MIAT down-regulation after CVT. But, despite several substantial limitations, such as; retrospective design, small sample size, data obtained from one center, and not evaluating the mRS in admission and 3-month after CVT we cannot definitively report an association between these lncRNAs and CVT severity.
Collectively, this study outlines a possible role for ANRIL lncRNA in CVT. We firstly observed significant ANRIL down-regulation in CVT patients compared to controls. This is a novel finding for CVT disease, which might guide a new direction for future research. We recommend a study with a larger sample size for better evaluation of gene expression and outcome assessment.