DNA damage and postural balance in multiple sclerosis patients

Combined effect of gender differences and fatiguing task on postural balance, functional mobility and fall risk in adults with multiple sclerosis: A preliminary study

AIM

To investigate the gender difference effect on postural balance, functional mobility, and fall risk after performing a fatiguing task in adults with multiple sclerosis (MS).

METHODS

Eleven women (30.91 ± 8.19 years) and seven men (30.29 ± 7.99 years) with relapsing-remitting MS performed a fatiguing task: three sets of the Five-repetition Sit-To-Stand Test (5-STST) were performed before and after the six-minute WalkTest (6MWT). Bipedal postural balance in eyes open and eyes closed conditions were assessed prefatigue (T0) and postfatigue (T3) using a force platform. Unipedal balance, functional mobility (Timed Up and Go Test), fall risk (Four Square Step Test) and fatigue [Visual Analogue Scale of Fatigue (VASF)] were assessed at T0 and T3. Heart rate (HR) and Rating of Perceived Exertion (RPE) were recorded before (only for HR), during and after the fatiguing task.

RESULTS

Compared to women, men showed an impairment of posturographic parameters [mean center of pressure (CoP) velocity (CoPVm) in both conditions (p < 0.05); CoP sway area (CoPAr) in both conditions (p < 0.01)], unipedal balance on the dominant leg (p <0.001), mobility (p<0.001) and an increased fall risk (p < 0.05). No gender differences were observed in 6MWT, 5-STST, HR, RPE, and VASF.

CONCLUSION

This preliminary study showed that fatiguing task negatively affected postural control, mobility and fall risk only in men. These gender differences were inconclusive but could be taken into account in postural balance rehabilitation programs for MS persons.

Polymorphism of the DNA repair gene XDP increases the risk of systemic lupus erythematosus but not multiple sclerosis in the Iranian population

BACKGROUND

Xeroderma pigmentosum group D ( XPD ) is an essential component of the nucleotide excision repair (NER) pathway, which can play a major role in DNA repair processes. A deficiency in this pathway was suggested as a causative factor of autoimmune diseases. Therefore, the current study aimed to investigate the relationship between XPD Lys751Gln polymorphism (rs13181) as one of the most common XDP polymorphisms and the risk of two important auto-immune diseases,namely systemic lupus erythematosus (SLE) and multiple sclerosis (MS) in the Iranian population.

METHODS

165 SLE patients and 165 age- and gender-matched healthy controls, and 150 MS patients and 150 age- and gender-matched healthy controls were genotyped for XPD rs13181 A/C polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The results of the present study have indicated that both C allele frequency ( P = 0.012; odds ratio: 1.5; 95% confidence interval: 1.1-2.07) and CC genotype ( P = 0.007; odds ratio: 2.46; 95% confidence interval: 1.2-4.7) in SLE patient were significantly higher than those in control group. Furthermore, there were no significant differences between MS patients and normal subjects concerning the genotype and the allele frequencies.

CONCLUSION

Our findings suggested that XPD rs13181 A/C polymorphism may be a crucial risk factor for the development of SLE but not MS in Iranian patients.

Vitamin D changes expression of DNA repair genes in the patients with multiple sclerosis

Oxidative stress (OS) plays an essential role in demyelination and tissue injury related to pathogenesis of multiple sclerosis (MS). On the other hand, vitamin D (VD) as an antioxidant reduces oxidative stress and has been used as adjuvant therapy in autoimmune diseases. Although VD supplementation is suggested as a protective and immunomodulation factor for MS patients, the molecular mechanisms remain unclear. Given that VD may modulate the immune system of MS patients through the DNA repair pathway, we aimed to evaluate the effects of VD supplementation in DNA repair genes expression including OGG1, MYH, MTH1, and ITPA. Transcript levels were measured using the RT-qPCR method in peripheral blood mononuclear cells (PBMCs) of relapsing-remitting multiple sclerosis (RRMS) patients before and after two months of VD supplementation. Furthermore, in silico analysis and correlation gene expression analysis was performed to find the biological binding sites and the effect of NRF2 on the regulation of DNA repair genes. Our data revealed that in MS patients, 2-month VD treatment significantly altered the expression of MYH, OGG1, MTH1, and NRF2 genes. A significant correlation was observed between DNA repair genes and NRF2 expression, which was confirmed by the presence of antioxidant response element (ARE) binding sites in the promoter of OGG1, MYH, and MTH1 genes. This study demonstrated that the impact of VD on MS patients may be mediated through the improvement of DNA repair system efficiency. This finding brought some new evidence for the involvement of DNA repair genes in the physiopathology of MS patients.