At present, the cause of MS is not fully understood, but knowledge of the genetic factors involved is essential for effective diagnosis and identification of the most appropriate MS therapeutic interventions. In this study, three genes (LASP1, TUBA1c and S100A6) with high degree, high closeness centrality and high betweenness measures, were highlighted as potential MS candidate regulator markers. These three genes (LASP1, TUBA1c and S100A6) seem to be the most significant genes in the MS disease process. Patients with MS are known to suffer from a number of digestive problems  and studies have shown that LASP1  and S100A6 genes have high expression in the digestive system. A link can therefore be established between the expression of these genes, MS and gastrointestinal problems in MS patients.
S100A6 functioning in a wide range of cell types, is a member of the S100 family and may be involved in and expressed in several types of human cancers . S100 family expression in MS patients could be considered as a diagnostic biomarker for MS, in which its inhibition of demyelinating nerve cells shows that S100 proteins could act as a candidate therapeutic target in MS . Keiko Komatsu et al.(2000), reported increased expression of S100A6 (Calcyclin), a calcium-bound protein of the S100 family, in human colorectal adenocarcinoma ; in this way, Eva Peterova (2021) reported an overexpression of S100 protein-encoding mRNA in both colorectal cancer cell lines . A study by Bartkowska et al.  showed that in response to different stress conditions, the level of S100A6 decreased in several brain structures, indicating that S100A6 may modulate stress responses. In an autoimmune disease study, a genome-wide methylation array has identified a few hypomethylated immune-related genes, amongst them S100A6 which shows up-regulation in autoimmune encephalitis patients .
Even though S100A6 is involved in many biological phenomena e.g. cell proliferation, cytoskeletal dynamics and tumorigenesis, and some of its biological activity is still unknown . At the transcriptional level, upstream stimulatory factor and Nuclear factor-kappa B (NF-κB) activates the S100A6 gene promoter, although p53 might act indirectly to suppress transcription of the S100A6 gene .
Microtubules, that are essential for multiple cellular processes, are constructed from homologous tubulin proteins. Microtubules shape crucial cytoskeletal structures that play a pivotal role in creating and maintaining neuronal mechanistic, biochemical functions such as polarity, regulating neuronal morphology, dendrite growth, neuron migration throughout brain development, transporting cargo, and scaffolding signaling molecules to form signaling hubs, and are vulnerable to degradation and disorganization in a variety of neurodegenerative diseases [38-40]. Malfunction of microtubules (Tuba1c) is also considered as the central physiopathological mechanism of neurodegenerative diseases and abnormalities in the regulatory pathways of microtubules disrupt the properties and functions of microtubules, leading to nerve damage . In a 2006 study, a decreased expression of the TUBA1C gene in Parkinson's disease was demonstrated by quantitative analysis of gene expression .
LASP1 )The LIM and SH3 protein 1) a focal adhesion adaptor protein, is an actin-binding, signaling pathway-regulated phosphoprotein and localizes within multiple sites of dynamic actin assembly. It has the potential to interact with various molecules, and is highly expressed in the adult central nervous system. It is ubiquitously expressed in normal tissues, and it transmits signals from the cytoplasm into the nucleus. It is a versatile structural, signaling, and biomarker protein and plays a crucial role in the growth and metastasis of gastric cancer, as well as being overexpressed in several other cancers [43-48]. Also, overexpression of LASP1 is often seen in colon cancer tissues, especially in metastatic colon cancer tissues. LASP1 can cause the progression and metastasis of colorectal cancer (CRC), but its mechanism is still unclear . Another study showed that LASP1 binds to the calcium-binding protein family (S100A) and increases its expression in colon cancer . this way, statistical analysis revealed that LASP1 and S100P are correlated (Kappa = 0.347, P < 0.01). Microarray data has revealed that alterations in LASP1 proteins affect cell migration, adhesion, and cytoskeletal organization . LASP1, significantly expressed by CNS neurons, is localized at synaptic sites .
A couple of significant transcription factors that interact with these hub genes were identified in this study. The YY1 transcription factor (Yi and Yang 1) is a multifactorial protein that, depending on the cell tissue, can activate or suppress gene expression . It is expressed in the nervous system. The YY1 promoter lacks the usual TATA box but has a rich GC sequence and therefore resembles a large subset of housekeeping and growth regulator genes. These features suggest that it may play an important role in development. In the central nervous system, myelination is performed by oligodendrocytes. YY1 function in oligodendrocytes was first reported by Berndt et al (2001). YY1 activates the promoter of myelin lipids and has been identified as an important player in myelination of the central nervous system during growth. In multiple neurodegenerative diseases, YY1 function is degraded through distinct mechanisms, including protein utilization, protein degradation, and ectopic nuclear / cytoplasmic shuttle (N/C). These disorders inhibit YY1 transcriptional activity and lead to gene transcriptional abnormalities that contribute to disease pathogenesis. A future goal in YY1 research is to discover other potential mechanisms that lead to YY1 dysfunction in neurodegenerative diseases, such as ectopic changes after translation .
NFAT is a family of transcription factors originally described as key factors in the immune response. There are five major members of the NFAT family: NFATc3 is one of five members of the NFAT transcription factor family that act as signal integrators because their function is to bind STAT3, c-Jun, CREB, and ATF3 factors at specific DNA binding sites. NFATs cannot be regulated alone and act as calcium-dependent transcription factors. The antigen-mediated T cell receptor (TCR) mediates multiple signaling cascades, including phospholipase C (PLC) -dependent pathways that are secondary messengers of inositol-1,4,5-triphosphate (IP3) and diacylglycerol (DAG). IP3 binds to the IP3 receptor in the endoplasmic reticulum (ER) and releases Ca2+ ions into the cytoplasm. .
NFATc1-4 activates intracellular calcium via dephosphorylation. Calcinurin activates a calcium / calmodulin-dependent phosphatase, which detects the transmitter signal to the nucleus (NLS) and carries it to the nucleus. This acts as a link between calcium signaling and NFAT-dependent gene transcription. Conversely, NFAT inactivation is mediated by phosphorylation by kinases that either retain NFAT in the cytoplasm or enhance nuclear export. According to a recent study, native human astrocytes also express NFAT and transmit to the nucleus . The findings suggest that NFATs control pathways involved in astrocyte activation and, therefore, may affect neuronal cell survival. Such a compelling idea suggests that NFAT is employed in neurological pathologies associated with neuro-inflammation in astrocytes. The findings show that NFATc3 is defined as a marker of a specific subset of astrocytes that are activated in response to lesions, as well as some degree of heterogeneity among astrocytes that may have consequences for cells in the nervous system . Preliminary findings in neuroblast cells have shown that various treatments that alter tubulin polymerization, such as reducing the mineral zinc, prevent the transfer of NFAT to the nucleus.
In addition, NFAT clusters gradually move away from the microtubules and communicate by transporting NFAT to the nucleus. Therefore, it has been shown that the association of NFAT with the microtubule network can increase the concentration of this transcription factor around the nucleus, and/or facilitate its interaction with nuclear pores. In agreement with a functional relationship between NFAT and microtubules, it has been observed that the degradation of several proteins that control the proper organization of the microtubule network, and the actin-cytoskeletal linker, disrupts the nucleus and transcriptional activity of NFAT. Overall, it indicates the involvement of microtubules in NFAT nuclear stimulation . The LASP1 gene enhances NFAT2 nuclear translocation by activating the nuclear factor Akt . NFAT can affect processes such as axon growth, synaptogenesis, Schwann cell differentiation, and myelination . In general, it can be concluded that increase of the expression of LASP1 and S100A6 genes and decrease the expression of the TUBA1C gene in multiple sclerosis disrupts NFAT transcriptional activity. Although the role of NFAT in regulating the immune system is well established, our knowledge of NFAT in human disease is limited. The function of NFAT in other aspects of human immune or inflammatory diseases is also largely unknown .
On this basis, the present study confirmed the importance of three gene expression patterns (LASP1, S100A6, TUBA1C) for understanding the transcriptome complexity of MS. This leads us to conclude that upregulation of LASP1 and S100A6 genes along with down-regulation of TUBA1C is central to MS pathology. To our knowledge, this is the first report to evaluate the level of expression of the above genes for discovery of a transcriptomic signature for MS disease. These findings provide a potential mechanism for some significant biomarkers responsible for the pathogenesis of MS. However, we still have a long way to go to understanding the larger transcriptomic profile for this disease. This study provides initial data to further investigate the possible role of these genes in the pathogenesis of MS.