Heterogeneity of serum gelatinases MMP-2 and MMP-9 isoforms and charge variants.

The matrix metalloproteinases (MMPs) gelatinase A (MMP-2) and gelatinase B (MMP-9) are mediators of brain injury in multiple sclerosis (MS) and valuable biomarkers of disease activity. We applied bidimensional zymography (2-DZ) as an extension of classic monodimensional zymography (1-DZ) to analyse the complete pattern of isoforms and post-translational modifications of both MMP-9 and MMP-2 present in the sera of MS patients. The enzymes were separated on the basis of their isoelectric points (pI) and apparent molecular weights (Mw) and identified both by comparison with standard enzyme preparations and by Western blot analysis. Two MMP-2 isoforms, and at least three different isoforms and two different states of organization of MMP-9 (the multimeric MMP-9 and the N-GAL-MMP-9 complex) were observed. In addition, 2-DZ revealed for the first time that all MMP-9 and MMP-2 isoforms actually exist in the form of charge variants: four or five variants in the NGAL complex, more charge variants in the case of MMP-9; and five to seven charge variants for MMP-2. Charge variants were also observed in recombinant enzymes and, after concentration, also in sera from healthy individuals. Sialylation (MMP-9) and phosphorylation (MMP-2) contributed to molecular heterogeneity. The detection of charge variants of MMP-9 and MMP-2 in MS serum samples illustrates the power of 2-DZ and demonstrates that in previous studies MMP mixtures, rather than single molecules, were analysed. These observations open perspectives for better diagnosis and prognosis of many diseases and need to be critically interpreted when applying other methods for MS and other diseases.

Multiple Sclerosis Progression and Relapse Activity in Children.

Importance: Although up to 20% of patients with multiple sclerosis (MS) experience onset before 18 years of age, it has been suggested that people with pediatric-onset MS (POMS) are protected against disability because of greater capacity for repair. Objective: To assess the incidence of and factors associated with progression independent of relapse activity (PIRA) and relapse-associated worsening (RAW) in POMS compared with typical adult-onset MS (AOMS) and late-onset MS (LOMS). Design, Setting, and Participants: This cohort study on prospectively acquired data from the Italian MS Register was performed from June 1, 2000, to September 30, 2021. At the time of data extraction, longitudinal data from 73 564 patients from 120 MS centers were available in the register. Main Outcomes and Measures: The main outcomes included age-related cumulative incidence and adjusted hazard ratios (HRs) for PIRA and RAW and associated factors. Exposures: Clinical and magnetic resonance imaging features, time receiving disease-modifying therapy (DMT), and time to first DMT. Results: After applying the inclusion and exclusion criteria, the study assessed 16 130 patients with MS (median [IQR] age at onset, 28.7 [22.8-36.2 years]; 68.3% female). Compared with AOMS and LOMS, patients with POMS had less disability, exhibited more active disease, and were exposed to DMT for a longer period. A first 48-week-confirmed PIRA occurred in 7176 patients (44.5%): 558 patients with POMS (40.4%), 6258 patients with AOMS (44.3%), and 360 patients with LOMS (56.8%) (P < .001). Factors associated with PIRA were older age at onset (AOMS vs POMS HR, 1.42; 95% CI, 1.30-1.55; LOMS vs POMS HR, 2.98; 95% CI, 2.60-3.41; P < .001), longer disease duration (HR, 1.04; 95% CI, 1.04-1.05; P < .001), and shorter DMT exposure (HR, 0.69; 95% CI, 0.64-0.74; P < .001). The incidence of PIRA was 1.3% at 20 years of age, but it rapidly increased approximately 7 times between 21 and 30 years of age (9.0%) and nearly doubled for each age decade from 40 to 70 years (21.6% at 40 years, 39.0% at 50 years, 61.0% at 60 years, and 78.7% at 70 years). The cumulative incidence of RAW events followed a similar trend from 20 to 60 years (0.5% at 20 years, 3.5% at 30 years, 7.8% at 40 years, 14.4% at 50 years, and 24.1% at 60 years); no further increase was found at 70 years (27.7%). Delayed DMT initiation was associated with higher risk of PIRA (HR, 1.16; 95% CI, 1.00-1.34; P = .04) and RAW (HR, 1.75; 95% CI, 1.28-2.39; P = .001). Conclusions and Relevance: PIRA can occur at any age, and although pediatric onset is not fully protective against progression, this study's findings suggest that patients with pediatric onset are less likely to exhibit PIRA over a decade of follow-up. However, these data also reinforce the benefit for DMT initiation in patients with POMS, as treatment was associated with reduced occurrence of both PIRA and RAW regardless of age at onset.

Structure-dependent inhibition of gelatinases by dietary antioxidants in rat astrocytes and sera of multiple sclerosis patients.

We investigated whether polyphenols modulate the expression and activity of the enzymes gelatinases A (MMP-2) and B (MMP-9), involved in the pathogenesis of multiple sclerosis (MS). LPS-activated primary rat astrocytes were treated with the flavonoids quercetin (QRC) and cathechins [green tea extract (GTE)] and the non-flavonoids resveratrol (RSV) and tyrosol/hydroxytyrosol (Oliplus). As assessed by zymography and RT-PCR, RSV and Oliplus, but not QRC and GTE, dose-dependently inhibited the LPS-induced levels and mRNA expression of MMP-2 and MMP-9. By contrast, in cell-free systems direct inhibition of gelatinase activity in MS sera was determined by QRC and GTE, but not by RSV. Oliplus was only partially effective. Our results indicate that the flavonoids and non-flavonoids tested exert their inhibitory effect on MMPs, displaying different mechanisms of action, possibly related to their structure. Therefore, their combined use may represent a powerful tool for the down-regulation of MMPs in the course of MS.

Anti-inflammatory nutritional intervention in patients with relapsing-remitting and primary-progressive multiple sclerosis: A pilot study.

The aim of this work was to assess the influence of nutritional intervention on inflammatory status and wellness in people with multiple sclerosis. To this end, in a seven-month pilot study we investigated the effects of a calorie-restricted, semi-vegetarian diet and administration of vitamin D and other dietary supplements (fish oil, lipoic acid, omega-3 polyunsaturated fatty acids, resveratrol and multivitamin complex) in 33 patients with relapsing-remitting multiple sclerosis and 10 patients with primary-progressive multiple sclerosis. At 0/3/6 months, patients had neurological examination, filled questionnaires and underwent anthropometric measurements and biochemical analyses. Serum fatty acids and vitamin D levels were measured as markers of dietary compliance and nutritional efficacy of treatment, whereas serum gelatinase levels were analyzed as markers of inflammatory status. All patients had insufficient levels of vitamin D at baseline, but their values did not ameliorate following a weekly administration of 5000 IU, and rather decreased over time. Conversely, omega-3 polyunsaturated fatty acids increased already after three months, even under dietary restriction only. Co-treatment with interferon-beta in relapsing-remitting multiple sclerosis was irrelevant to vitamin D levels. After six months nutritional treatment, no significant changes in neurological signs were observed in any group. However, serum levels of the activated isoforms of gelatinase matrix metalloproteinase-9 decreased by 59% in primary-progressive multiple sclerosis and by 51% in relapsing-remitting multiple sclerosis patients under nutritional intervention, including dietary supplements. This study indicates that a healthy nutritional intervention is well accepted by people with multiple sclerosis and may ameliorate their physical and inflammatory status.