Expression analysis of long non-coding RNAs and their target genes in multiple sclerosis patients

Molecular mechanism of lncRNAs in pathogenesis and diagnosis of auto-immune diseases, with a special focus on lncRNA-based therapeutic approaches

Autoimmune diseases are a diverse set of conditions defined by organ damage due to abnormal innate and acquired immune system responses. The pathophysiology of autoimmune disorders is exceedingly intricate and has yet to be fully understood. The study of long non-coding RNAs (lncRNAs), non-protein-coding RNAs with at least 200 nucleotides in length, has gained significant attention due to the completion of the human genome project and the advancement of high-throughput genomic approaches. Recent research has demonstrated how lncRNA alters disease development to different degrees. Although lncRNA research has made significant progress in cancer and generative disorders, autoimmune illnesses are a relatively new research area. Moreover, lncRNAs play crucial functions in differentiating various immune cells, and their potential relationships with autoimmune diseases have received growing attention. Because of the importance of Th17/Treg axis in auto-immune disease development, in this review, we discuss various molecular mechanisms by which lncRNAs regulate the differentiation of Th17/Treg cells. Also, we reviewed recent findings regarding the several approaches in the application of lncRNAs in the diagnosis and treatment of human autoimmune diseases, as well as current challenges in lncRNA-based therapeutic approaches to auto-immune diseases.

Long Non-Coding RNAs, Novel Offenders or Guardians in Multiple Sclerosis: A Scoping Review

Multiple sclerosis (MS), a chronic inflammatory demyelinating disease of the central nervous system, is one of the most common neurodegenerative diseases worldwide. MS results in serious neurological dysfunctions and disability. Disturbances in coding and non-coding genes are key components leading to neurodegeneration along with environmental factors. Long non-coding RNAs (lncRNAs) are long molecules in cells that take part in the regulation of gene expression. Several studies have confirmed the role of lncRNAs in neurodegenerative diseases such as MS. In the current study, we performed a systematic analysis of the role of lncRNAs in this disorder. In total, 53 studies were recognized as eligible for this systematic review. Of the listed lncRNAs, 52 lncRNAs were upregulated, 37 lncRNAs were downregulated, and 11 lncRNAs had no significant expression difference in MS patients compared with controls. We also summarized some of the mechanisms of lncRNA functions in MS. The emerging role of lncRNAs in neurodegenerative diseases suggests that their dysregulation could trigger neuronal death via still unexplored RNA-based regulatory mechanisms. Evaluation of their diagnostic significance and therapeutic potential could help in the design of novel treatments for MS.

Scavenging the hidden impacts of non-coding RNAs in multiple sclerosis

Multiple sclerosis (MS) is a chronic neuroinflammatory disease that causes severe neurological dysfunction leading to disabilities in patients. The prevalence of the disease has been increasing gradually worldwide, and the specific etiology behind the disease is not yet fully understood. Therapies aimed against treating MS patients have been growing lately, intending to delay the disease progression and increase the patients' quality of life. Various pathways play crucial roles in developing the disease, and several therapeutic approaches have been tackling those pathways. However, these strategies have shown several side effects and inconsistent efficacy. MicroRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) have been shown to act as key players in various disease pathogenesis and development. Several proinflammatory and anti-inflammatory miRNAs have been reported to participate in the development of MS. Hence, the review assesses the role of miRNAs, lncRNAs, and circRNAs in regulating immune cell functions better to understand their impact on the molecular mechanics of MS.

Epigenetic modifications of tumor necrosis factor-alpha in joint cartilage tissue from osteoarthritis patients - CONSORT

BACKGROUND

Osteoarthritis (OA) remains one of the most common osteopathy for centuries, which can be attributed to multiple risk factors including mechanical and biochemical ones. More and more studies verified that inflammatory cytokines play important roles in the progression of OA, such as tumor necrosis factor-alpha (TNF-α). In this study, we aimed to investigate the relationship between epigenetic manifestations of TNF-? and the pathogenesis of OA.

METHODS

Totally, 37 OA patients' cartilage was collected through the knee joint and 13 samples of articular cartilage as healthy control was collected through traumatic amputation. Real-time PCR, Western blot and ELISA analysis were performed to observe the expression of target genes and proteins in collected samples.

RESULTS

Compared with the healthy control group, TNF-? was over-expressing in cartilage which was collected from OA patients. DNA hypomethylation, histone hyperacetylation and histone methylation were observed in the TNF-? promoter in OA compared with normal patients, and we also studied series of enzymes associated with epigenetics. The results showed that by increasing DNA methylation and decreasing histone acetylation in the TNF-? promoter, and TNF-? over-expression in OA cartilage was suppressed, histone methylation has no significant correlation with OA.

CONCLUSION

In conclusion, the changes of epigenetic status regulate TNF-α expression in the cells, which are pivotal to the OA disease process. These results may give us a better understanding of OA and may provide new therapeutic options.

Dysregulation of long noncoding RNA MEG3 and NLRC5 expressions in patients with relapsing-remitting multiple sclerosis: is there any correlation?

Long noncoding RNA MEG3 and NLRC5 genes are both involved in the immune system and the regulation of NLRC5 by MEG3 is documented in rheumatoid arthritis. Therefore, we intended to evaluate the association between the expressions of MEG3 and NLRC5 in multiple sclerosis (MS). Forty relapsing and remitting MS (RRMS) patients (20 in each group) and twenty healthy individuals were enrolled. The expression level of MEG3 and NLRC5 was assessed in peripheral blood mononuclear cells. Sub-group analysis demonstrated that the expression level of MEG3 is reduced in the relapse patient group compared to remission and healthy groups (p < 0.001). The expression level of NLRC5 was higher in whole patients compared with healthy controls (p < 0.05). Moreover, a negative correlation was observed between the expression of these two genes (r = -0.73, p < 0.0001). To conclude, our findings showed the dysregulation of MEG3 and NLRC5 expressions in RRMS patients. Also, the converse association of MEG3 and NLRC5 reflects that the role of MEG3 in MS development is probably mediated by modulation of NLRC5.

The emerging role of noncoding RNAs in neuroinflammation: Implications in pathogenesis and therapeutic approaches

Noncoding RNAs (ncRNAs) are important regulators of gene expression in different cell processes. Due to their ability in monitoring neural development genes, these transcripts confer neurons with the potential to exert broad control over the expression of genes for performing neurobiological functions. Although the change of ncRNA expression in different neurodegenerative diseases has been reviewed elsewhere, only recent evidence drove our attention to unravel the involvement of these molecules in neuroinflammation within these devastating disorders. Remarkably, the interactions between ncRNAs and inflammatory pathways are not fully recognized. Therefore, this review has focused on the interplay between diverse inflammatory pathways and the related ncRNAs, including microRNAs, long noncoding RNAs, and competing endogenous RNAs in Alzheimer's disease, Parkinson's diseases, amyotrophic lateral sclerosis, epilepsy, multiple sclerosis, Huntington's disease, and prion diseases. Providing novel insights in the field of combining biomarkers is a critical step for using them as diagnostic tools and therapeutic targets in clinical settings.

What do we know about the role of lncRNAs in multiple sclerosis?

Multiple sclerosis is a chronic, inflammatory and degenerative disease of the central nervous system of unknown aetiology although well-defined evidence supports an autoimmune pathogenesis. So far, the exact mechanisms leading to autoimmune diseases are still only partially understood. We know that genetic, epigenetic, molecular, and cellular factors resulting in pathogenic inflammatory responses are certainly involved. Long non-coding RNAs (lncRNAs) are non-protein coding transcripts longer than 200 nucleotides that play an important role in both innate and acquired immunity, so there is great interest in lncRNAs involved in autoimmune diseases. The research on multiple sclerosis has been enriched with many studies on the molecular role of lncRNAs in the pathogenesis of the disease and their potential application as diagnostic and prognostic biomarkers. In particular, many multiple sclerosis fields of research are based on the identification of lncRNAs as possible biomarkers able to predict the onset of the disease, its activity degree, its progression phase and the response to disease-modifying drugs. Last but not least, studies on lncRNAs can provide a new molecular target for new therapies, missing, so far, a cure for multiple sclerosis. While our knowledge on the role of lncRNA in multiple sclerosis has recently improved, further studies are required to better understand the specific role of lncRNAs in this neurological disease. In this review, we present the most recent studies on molecular characterization of lncRNAs in multiple sclerosis disorder discussing their clinical relevance as biomarkers for diagnosis and treatments.

LncRNA GAS5 and miR-137 Polymorphisms and Expression are Associated with Multiple Sclerosis Risk: Mechanistic Insights and Potential Clinical Impact

The pathogenesis of multiple sclerosis (MS) is influenced by the interaction of genetic and epigenetic mechanisms. The long noncoding RNA GAS5 acts as a competing endogenous RNA for microRNA-137 and is involved in demyelination. We investigated the association of GAS5 and miR-137 expression and their polymorphisms with MS susceptibility. One hundred and eight MS patients and 104 healthy controls were included. Expression analysis and genotyping of GAS5-rs2067079 and miR-137-rs1625579 single nucleotide polymorphisms were performed by qPCR. Serum GAS5 was upregulated, while serum miR-137 was downregulated in MS compared with the controls. Serum miR-137 was an excellent discriminator of MS patients from the controls (AUC = 0.97) and a negative independent predictor of MS in multivariate logistic analysis. Serum GAS5 expression was positively correlated with the expanded disability status scale scores in the relapsing-remitting MS patients. The rs2067079TT minor homozygote genotype was associated with an increased MS risk, while the rs1625579G minor allele was protective. rs1625579 showed an age-specific effect, while the rs2067079 affected the MS risk in gender- and age-specific manners. In MS patients, rs2067079TT was associated with a higher serum GAS5 than other genotypes, while serum miR-137 did not differ between rs1625579 genotypes. Our results suggest serum GAS5 and miR-137 as MS biomarkers, with miR-137 as a negative predictor of MS risk and GAS5 as a marker of MS severity. We propose rs2067079 and rs1625579 as novel genetic markers of MS susceptibility, and at least, rs2067079 possibly impacts the crosstalk between GAS5 and miR-137.