GAS5 is a lncRNA involved in cell cycle regulation and takes part in normal growth arrest in T cells and non-transformed lymphocytes (54). The GAS5 has several different activities, including different effects on the pathogenesis/pathophysiology of autoimmune diseases and inflammatory diseases; in addition, it can have a suppressive effect on glucocorticoids (18). A previous investigation into identifying significant genes in RRMS involved the analysis of regulatory networks (55). Building on this work, we analyzed the GAS5-miRNAs-mRNAs network and found that miR-651-5p, hsa-miR-345-5p, hsa-miR-520a-5p, hsa-miR-520d-5p, hsa-miR-524-5p, and hsa-miR-525-5p are highly associated with GAS5 in this network, respectively. Additionally, Chen et al. investigated this in 2021 and identified dysregulation of miR-651-5p in Parkinson's disease (56). However, to our knowledge, there hasn't been any study on the involvement of these miRNAs in MS. Nonetheless, our findings suggest that miR-651-5p and GAS5 may interact and potentially serve as a new mitochondrial hallmark for MS. We used gene set enrichment analysis tools to evaluate the GAS5 protein targets functionally. These genes mainly regulate gene expression, apoptosis, cellular response to stress, and FoxO singling pathways. In addition, these genes enrich RNA binding, protein kinase binding, and nuclear receptor binding. It was elucidated that GAS5 exerts regulatory control over the CD4 + T cell response and apoptosis in HIV patients by modulating miR-21 expression. They also explained that targeting these genes might be beneficial to create T cell over-activation in other infectious or inflammatory diseases (57). Furthermore, it has been demonstrated that the down-regulation of GAS5 in patients with atherosclerosis can effectively attenuate both inflammation and oxidative stress. This is supported by findings indicating that the overexpression of GAS5 in T helper I cells of these patients leads to increased levels of inflammation and oxidative stress (58), suggesting that overexpression of GAS5 could be a contributing factor to the development of these conditions. Alternatively, Zhao et al. provided evidence that GAS5 performs as a tumor suppressor in human glioma stem cells by up-regulating FoxO expression through the repression of miR196-a-5p (59). Meanwhile, in MS patients, de Oliveira et al. observed a reduction in the transcription level of genes that promote cell death, including BAD, BAX, and FASL in PBMCs. The abnormal expression of genes associated with apoptosis may contribute to the expansion of persistent memory autoreactive lymphocytes and ultimately worsen MS (60). Wang et al. identified In two families, loss of functional activity of a nuclear receptor called NR1H3 has been associated with primary progressive multiple sclerosis due to substituting glutamine for arginine in the NR1H3 protein (61). The results from these investigations provide supporting evidence for our enrichment analysis findings concerning the functional role of proteins associated with GAS5 and their involvement in specific pathways. Using GeneCards and Harmonizome databases, we identified transcription factors and protein kinases that are associated with GAS5. A previous study has demonstrated a down-regulation of RUNX1 in Multiple Sclerosis (MS) patients, and as the disease progressed, the down-regulation of GAS5 was further enhanced (62). Miao et al. conducted an in-depth analysis of the interaction between RUNX1 and GAS5, wherein they observed that the overexpression of GAS5 impeded cell cycle progression and proliferation in Diffuse Large B-cell lymphoma (DLBCL). Furthermore, their investigation demonstrated the inverse relationship between the inhibition of cell proliferation induced by GAS5 in DLBCL and the down-regulation of RUNX1 expression (63). In addition, YY1, a transcription factor, has a negative effect on GAS5 expression levels by binding to its promoter and inhibiting its transcription. The interaction of YY1 with lncRNA GAS5 leads to increased PFKFB3 transcription, intensifying neuronal glycolysis, thereby worsening brain I/R (ischemia/reperfusion) injury (64). Propofol induces GAS5 in oral squamous cell carcinoma (OSCC) cells, which competes with miR-1297, reducing its inhibitory effect on GSK3β, leading to increased GSK3β and decreased Mcl1. FoxO1 facilitates GAS5 transcription in response to propofol treatment. These findings suggest that propofol has antitumor effects in OSCC cells, and the FoxO1-GAS5-miR-1297-GSK3β axis is crucial to propofol-induced apoptosis (65). Our findings indicate that GAS5-related transcription factors and protein kinase contribute significantly to various human diseases, especially neurodegenerative conditions, demonstrating the importance of these factors in such diseases. Through our investigation of GAS5 target mRNAs and GAS5-associated RBPs, we identified 10 mRNA targets and 21 RBPs. hnRNPA1, an RBP, has been implicated in the pathogenesis of MS. Specifically, this study identified nine single nucleotide variants (SNVs) within the hnRNPA1-M9 domain, which resulted in the mislocalization of hnRNPA1 to the cytoplasm and the formation of stress granules. These disease-associated SNVs were also found to induce cell apoptosis in MS patients. Consequently, the researchers concluded that mutations in hnRNPA1 may contribute to the underlying mechanisms of MS pathogenesis (66). A case-report study demonstrated that the presence of permutation FMR1 (55–200 CGG repeats), acting as an RBP, can lead to Lamin A/C and αβ-crystallin aggregation within neural cells. These aggregated proteins are postulated to be involved in developing autoimmune diseases, particularly MS (67). Moreover, QKI is known to be involved in the regulation of normal myelinogenesis. The decreased expression of QKI has been associated with disturbances in axonal myelination and the pathogenesis of MS (68). Alternatively, in a comparative study between MS patients and control subjects, the transcriptional level of vascular endothelial growth factor A (VEGFA) was examined in PBMC. The results revealed a down-regulation of VEGFA expression in both cerebrospinal fluid (CSF) and PBMC of MS patients (69). Gayo et al., in their study on MS patients, observed an increase in the level of IL-10 following treatment with glucocorticoids. They proposed that the up-regulation of IL10 contributes to the effectiveness of steroids in controlling MS (70). Dysregulation of KLF2, a transcription factor, has been observed to contribute to the aggravation of demyelination in the spinal cord within the experimental autoimmune encephalomyelitis (EAE) murine model, suggesting that KLF2 plays a protective role in EAE and serves to suppress neuronal degeneration (71). This investigation revealed that both GAS5 target mRNAs and GAS5-related RBPs are significantly instrumental in either the advancement or protection of MS. This suggests that these biomolecules could potentially serve as a diagnostic and therapeutic target for MS. MS researchers are currently prioritizing the search for specific biomarkers to improve diagnosis. Additionally, there is an insufficiency of efficacious therapeutic interventions for progressive MS, making the development of new treatments imperative (72). In this study, we examined the potential roles of LncRNA GAS5 on RRMS vulnerability. Therefore, we assessed the relationship between GAS5 expression level in PBMC and clinical data of RRMS patients, and we determined the significant correlation between GAS5 expression and family history and gender. Consequently, GAS5 was up-regulated in the patients with family history and in females compared to the patients without family history and males, respectively. In addition, we observed overexpression of GAS5 in RRMS patients compared to the normal group. Based on the obtained results, we investigated prior studies and identified relevant studies that corroborate our findings, including Gharesouran et al., which demonstrated that GAS5 expression in MS patients was higher than in controls (16). Additionally, Senousy et al. performed a study in 2020 and showed serum up-regulation of GAS5 in MS patients (20). Previous investigations have primarily examined the transcriptional level of GAS5 in the patient's serum. However, the main goal of the current study was to evaluate the expression of GAS5 exclusively within PBMCs derived from the samples. This methodological approach facilitated the removal of erythrocytes and granulocytes from the analyzed samples. Considering the crucial involvement of T cells within PBMCs in the pathogenesis of multiple sclerosis (MS), evaluating GAS5 expression in PBMCs bears significant implications for comprehensive MS sample studies. Although we obtained the diagnostic potential of GAS5 as AUC = 0.6498, Senousy et al. indicated that GAS5 could distinguish MS patients from controls by ROC curve with AUC = 0.73 (20). Notably, if future studies increase the number of samples, the power discrimination of GAS5 will be enhanced. Overall, the transcriptional level of GAS5, particularly in PBMCs, has been identified as a potential hallmark for future evaluation of the role of mitochondria in MS disease. Exosomes exhibit a non-random assortment of components derived from their parent cells, displaying a distinct composition that mirrors the cellular activation status and susceptibility to pathological states of the originating tissue. Moreover, extracellular RNA, RNA-binding proteins, and various cellular proteins demonstrate differential expression in exosomes. Notably, the cargo of exosomes released from cell cultures is predominantly composed of diverse classes of RNA, such as miRNA and long non-coding RNAs (73). In this study, cell cultures were employed to explore, for the first time, potential changes in the expression profiles of GAS5 and its targeted miRNAs in HMC3 cells and their derived exosomes following induction of redox imbalance and oxidative stress via tBHP. Following treatment, a significant upregulation of GAS5 expression was observed with a 50 µm tBHP concentration (redox imbalance) compared to both control and 200 µm tBHP conditions (oxidative stress). Additionally, a direct relationship was found between the expression levels of miR-651-5p and oxidative stress in both HMC3 cells and their derived exosomes. These findings indicate a significant association between redox imbalance and oxidative stress and the dysregulation of GAS5 and miR-651-5p expression in cells, underscoring their potential roles in the cellular stress response. Moreover, our results suggest that miR-651-5p may be transported into exosomes, especially under conditions of oxidative stress associated with MS. This transportation process could potentially be regulated by the interaction between GAS5 and miR-651-5p. While Farr et al. previously identified miR-651-5p as an indicator of lyssavirus infection in a human stem cell-derived neural model (74), there is a lack of studies investigating this miRNA in the context of MS, highlighting its potential for further exploration within the realm of MS research. Elucidating the intricate mechanisms governing the role of GAS5/miR-651-5p could offer valuable insights into disease pathogenesis and the role of mitochondria in MS. Mechanistically, it has been shown that energy-stress-induced GAS5 modulates mitochondrial tricarboxylic acid flux by disrupting the tandem association of metabolic enzymes: fumarate hydratase, malate dehydrogenase, and citrate synthase, which are canonical members of the tricarboxylic acid cycle. GAS5 negatively correlates with the levels of these associated mitochondrial metabolic enzymes in tumors and is beneficial for overall survival in individuals with breast cancer (75). It has been also reported that the knockdown of Yin-Yang 1 or GAS5 protects against ischemia/reperfusion-induced ischemic brain damage and improves overall neurological functions in vivo. Overall, Yin-Yang 1 interacts with lncRNA GAS5 to promote PFKFB3 transcription, enhancing neuronal glycolysis, which in turn exacerbates cerebral ischemia/reperfusion injury (76). Another study showed that GAS5 overexpression inhibited inflammation, oxidative stress, and pyroptosis in high-glucose-induced renal tubular cells by downregulating the expression of miR-452-5p (77). A recent study indicates that GAS5 is involved in pathways associated with neurodegeneration. The study suggests that a GAS5-targeting small molecule, NPC86, has significant therapeutic potential to prevent the onset of neurodegenerative diseases and dementias (78). Additionally, it was shown that silencing of the GAS5 alleviates neuronal cell apoptosis and inflammatory responses by sponging microRNA-93 to repress phosphatase and tensin homolog expression in spinal cord injury (79). Findings also indicate that GAS5 plays a role in regulating apoptosis, cell cycle, homeostasis of reactive oxygen species, and redox balance in MM cells. Reduced GAS5 expression is suggested to contribute to disease progression in malignant melanoma patients (80). In a study more relevant to MS, it was found that interference with GAS5 in transplanted microglia attenuates the progression of experimental autoimmune encephalomyelitis (EAE) and promotes remyelination in a lysolecithin-induced demyelination model. Consistently, higher levels of GAS5 are found in amoeboid-shaped microglia in MS patients. Further functional studies show that GAS5 suppresses the transcription of TRF4, a key factor controlling M2 macrophage polarization, by recruiting the polycomb repressive complex 2 (PRC2), thereby inhibiting M2 polarization (81). Altogether, uncovering the molecular basis of the interaction between oxidative stress, GAS5 expression, and loading of miR-651-5p in exosomes could reveal potential signaling pathways involved in MS pathobiology.