microRNAs: key modulators of disease-modifying therapies in multiple sclerosis

Peripheral blood mononuclear cells expression of miR-200c, miR-125b, miR-27b, miR-203, and miR-155 in patients with significant or insignificant coronary artery stenosis

Coronary artery disease (CAD) is one of the principal causes of death worldwide. Among several predisposing factors, inflammation and inflammatory genes play a significant role in disease pathogenesis. Inflammatory microRNAs, small noncoding RNAs involved in regulating inflammation, are promising candidates for understanding pathogenesis of CAD and developing diagnostic biomarkers. The aim of the study was to evaluate the alteration of miR-200c, miR-125b, miR-27b, miR-203 and, miR-155 in patients suffering from coronary artery stenosis and insignificant coronary artery stenosis compared to healthy subjects. In this study we compared expressions of five inflammatory miRNAs in peripheral blood mononuclear cells (PBMCs) of 72 patients suffering significant coronary artery stenosis (CAD), 74 individuals without coronary artery disease and 30 individuals with insignificant coronary artery stenosis (ICAD). After blood collection, PBMCs were isolated and RNA was extracted. Gene expression levels were assessed by SYBR green based real-time PCR. Statistical analysis was performed using R program. Expression levels of miR-200c, miR-203, and miR-155 were lower in subjects with ICAD than that in CAD patients and subjects of the control group. MiR-125b was downregulated in CAD and ICAD groups compared to the control group. PBMC miR-27b was upregulated in the CAD group as compared to the ICAD and control groups. Receiver operating characteristic curve analysis verified potential of three miRNAs in separating subjects with ICAD from CAD patients and healthy individuals. In conclusion, this original investigation suggested that altered expression of these five miRNAs may serve as a novel diagnostic biomarker discriminating clinical presentations of coronary artery diseases.

miRNA 548a-3p as biomarker of NEDA-3 at 2 years in multiple sclerosis patients treated with fingolimod

BACKGROUND

Multiple sclerosis (MS) is a disabling autoimmune demyelinating disorder affecting young people and causing significant disability. In the last decade, different microRNA (miRNA) expression patterns have been associated to several treatment response therapies such as interferon and glatiramer acetate. Nowadays, there is increasing interest in the potential role of miRNA as treatment response biomarkers to the most recent oral and intravenous treatments. In this study, we aimed to evaluate serum miRNAs as biomarkers of No Evidence of Disease Activity (NEDA-3) at 2 years in patients with relapsing remitting MS (RRMS) treated with fingolimod.

MAIN BODY

A Discovery cohort of 31 RRMS patients treated with fingolimod were identified from the CLIMB study and classified as No Evidence of Disease Activity (NEDA-3) or Evidence of Disease Activity (EDA-3) after 2 years on treatment. Levels of miRNA expression were measured at 6 months using human serum miRNA panels and compared in EDA-3 and NEDA-3 groups using the Wilcoxon rank sum test. A set of differentially expressed miRNA was further validated in an independent cohort of 22 fingolimod-treated patients. We found that 548a-3p serum levels were higher levels in fingolimod-treated patients classified as NEDA-3, compared to the EDA-3 group in both the Discovery (n = 31; p = 0.04) and Validation (n = 22; p = 0.03) cohorts 6 months after treatment initiation; miR-548a-3p provided an AUC of 0.882 discriminating patients with NEDA-3 at 2 years in the Validation cohort.

CONCLUSION

Our results show differences in miR-548a-3p expression at 6 months after fingolimod start in patients with MS with NEDA-3 at 2 years. These results provide class III evidence of the use of miR-548a-3p as biomarker of NEDA-3 in patients with fingolimod.

piRNA and miRNA Can Suppress the Expression of Multiple Sclerosis Candidate Genes

Multiple sclerosis (MS) is a common inflammatory demyelinating disease with a high mortality rate. MS is caused by many candidate genes whose specific involvement has yet to be established. The aim of our study was to identify endogenous miRNAs and piRNAs involved in the regulation of MS candidate gene expression using bioinformatic methods. A program was used to quantify the interaction of miRNA and piRNA nucleotides with mRNA of the target genes. We used 7310 miRNAs from three databases and 40,000 piRNAs. The mRNAs of the candidate genes revealed miRNA binding sites (BSs), which were located separately or formed clusters of BSs with overlapping nucleotide sequences. The miRNAs from the studied databases were generally bound to mRNAs in different combinations, but miRNAs from only one database were bound to the mRNAs of some genes. For the first time, a direct interaction between the complete sequence of piRNA nucleotides and the nucleotides of their mRNA BSs of target genes was shown. One to several clusters of BSs of miRNA and piRNA were identified in the mRNA of ADAM17, AHI1, CD226, EOMES, EVI5, IL12B, IL2RA, KIF21B, MGAT5, MLANA, SOX8, TNFRSF1A, and ZBTB46 MS candidate genes. These piRNAs form the expression regulation system of the MS candidate genes to coordinate the synthesis of their proteins. Based on these findings, associations of miRNAs, piRNAs, and candidate genes for MS diagnosis are recommended.

Macular volume and fovea thickness as OCT-criteria for multiple sclerosis. Preliminary results

Background. The characteristic optical coherence tomography (OCT) changes in the optic nerve head in patients with multiple sclerosis are known and have been described many times, however, the state of the macular area is described in a small number of publications.The aim: to analyze the changes in the macular area of the retina in patients with multiple sclerosis, to identify the OCT signs pathognomonic for this disease and to trace their changes over time as the disease progresses.Material and methods. In addition to the standard ophthalmological examination, 28 patients (55 eyes) diagnosed with multiple sclerosis underwent OCT of the macular zone to determine the thickness of the fovea and the volume of the macula in the 6 mm zone. The follow-up period was 6–12 years. The endpoints were the primary treatment and the most recent inspection.Results. At the initial examination, the visual acuity was 0.96 ± 0.24 (95% CI: 0.9–1.03), fovea thickness – 253.0 μm (Q1–Q3: 233.0–264.0), macular volume – 5.471 mm3 (Q1–Q3: 5.281–5.625). In 37 cases (67.3 %), the macular volume was below normal. The initial fovea thickness was below normal in 9 cases (16.4 %). At the end of the study, visual acuity did not change statistically (p = 0.824) and amounted to 0.96 ± 0.25 (95% CI: 0.90–1.04). The fi nal thickness of the fovea was 247.5 μm (Q1–Q3: 233.0–260.0), changes are statistically significant (p = 0.02). Number of cases with a thickness below normal in the fi nal study was 11 (20 %), change of frequency of cases was not statistically signifi cant (p = 0.5). The fi nal macular volume was 5.393 mm3 (Q1–Q3: 5.197–5.565), the changes are statistically significant (p = 0.023). The final number of cases with a volume below the norm was 42 (76.4 %), the change in the frequency of cases is close to statistically signifi cant (p = 0.063). At all stages of the study, there was no case of an isolated decrease in the thickness of the fovea without a decrease in the volume of the macula.Conclusion. The decrease in the volume of the macula with time while maintaining the thickness of the fovea within the normal range can be attributed to the pathognomonic OCT signs of multiple sclerosis. This criterion can be used for a comprehensive assessment of the course and therapy of this disease.

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 expression and prognostic value of miR-146a and miR-155 in Turkish patients with multiple sclerosis

Multiple sclerosis (MS) is an inflammatory, autoimmune demyelinating, and neurodegenerative disorder of the central nervous system. Interactions between environmental factors, predisposition genes, and determining genes appear to be involved in its etiology. Epigenetic mechanisms such as microRNA-mediated gene regulation can determine the susceptibility and severity of autoimmune diseases. Therefore, to determine the role of miR-146a and miR-155 in MS and its developmental stages, the expression levels in the serum of MS and clinically isolated syndrome (CIS) patients were compared with those of healthy controls. In the present study, the expression levels of miR-146a and miR-155 were assessed using quantitative Real-Time PCR in blood samples of 15 CIS patients and 61 relapsing-remitting multiple sclerosis (RRMS) patients alongside 32 healthy patients as controls. Furthermore, any associations with the clinicopathologic variables of the patients were also evaluated. Dysregulations were found only in the miR-146a and miR-155 expressions in the RRMS-Control group. When the RRMS patients were evaluated in terms of the characteristics of sex, annual attack rate, age of diagnosis, duration of follow-up, and immunomodulatory treatments used, no significant differences were observed. However, significant dysregulations were identified in miRNA expression in the vitamin D level, EDSS values, and the number of attacks. ROC curve analysis showed that miR-146a and miR-155 were significant in the RRMS-Control group for the area under the curve (AUC). It is possible that miR-146a may be associated with vitamin D deficiency and disease disability, while miR-155 may be associated with the number of attacks.

The global prevalence of familial multiple sclerosis: an updated systematic review and meta-analysis

BACKGROUND

Considering that many recent studies have reported the prevalence of familial multiple sclerosis (FMS), we performed an updated meta-analysis of the worldwide prevalence of FMS by the addition of recent publications.

METHODS

A search in PubMed, Scopus, the ISI Web of Science, and Google Scholar was undertaken up to 20 December 2020. The inclusion criteria were based on the CoCoPop approach (condition, context, and population). Meta-analysis of the qualified studies was conducted by comprehensive meta-analysis ver. 2 software.

RESULTS

The pooled prevalence of MS in relatives of 16,179 FMS cases was estimated to be 11.8% (95% CI: 10.7-13) based on a random-effects model. The pooled mean age of disease onset in adult probands was calculated to be 28.7 years (95% CI: 27.2 ± 30.2). Regarding 13 studies that reported the data of FMS in pediatrics (n = 877) and adults (n = 6636), the FMS prevalence in pediatrics and adults was 15.5% (95% CI: 13.8-17.4) and 10.8% (95% CI: 8.1-14.2), respectively. The prevalence of FMS in affected males (n = 5243) and females (n = 11,503) was calculated to be 13.7% (95% CI: 10.1-18.2) and 15.4% (95% CI: 10.3-22.4), respectively. The odds ratio of male/female in FMS cases was not statistically significant (OR = 0.9; 95% CI: 0.6-1.2, P = 0.55). Subgroup analysis demonstrated a significant difference in the prevalence of FMS between the geographical areas (P = 0.007). The meta-regression model indicated that the prevalence of FMS is lower with higher latitude and higher MS prevalence (P < 0.001). In contrast, meta-regression based on prevalence day was not statistically significant (P = 0.29).

CONCLUSIONS

The prevalence of FMS is higher in the pediatric group than that of adults, distinct between geographical areas, and diminishes with the increment of MS prevalence and latitude. Also, the symptoms initiate relatively at younger ages in the FMS cases. Interestingly, our analysis unveiled that FMS is not more prevalent in men than women and the risk of MS development in relatives is not higher when the affected proband is male.