Suppressed POL-1 pathway activity in BMS.

<p>A schematic model demonstrating the suppressed POL-1 pathway activity in BMS leading to activation of P53 dependent apoptosis. Over-expressed genes are depicted in red, down-expressed genes in green.</p

POL-1 pathway key genes verification by qRT-PCR.

<p>White dots represent BMS patients (N = 20), black dots represent RRMS patients (N = 15). Data are presented as relative quantification values using ΔCT method. The house keeping gene GAPDH expression levels were used as internal control for sample normalization. Low level of the POL-1 pathway key genes POLR1D (p = 0.001), RRN3 (p = 0.03) and LRPPRC (p = 0.03) is demonstrated in BMB patients as compared with RRMS patients.</p

Suppressed RNA-Polymerase 1 Pathway Is Associated with Benign Multiple Sclerosis

<div><p>Benign multiple sclerosis (BMS) occurs in about 15% of patients with relapsing-remitting multiple sclerosis (RRMS) that over time do not develop significant neurological disability. The molecular events associated with BMS are not clearly understood. This study sought to underlie the biological mechanisms associated with BMS. Blood samples obtained from a cohort of 31 patients with BMS and 36 patients with RRMS were applied for gene expression microarray analysis using HG-U133A-2 array (Affymetrix). Data were analyzed by Partek and pathway reconstruction was performed by Ingenuity for the most informative genes (MIGs). We identified a differing gene expression signature of 406 MIGs between BMS patients, mean±SE age 44.5±1.5 years, 24 females, 7 males, EDSS 1.9±0.2, disease duration 17.0±1.3 years, and RRMS patients, age 40.3±1.8 years, 24 females, 12 males, EDSS 3.5±0.2, disease duration 10.9±1.4 years. The signature was enriched by genes related RNA polymerase I (POL-1) transcription, general inflammatory response and activation of cell death. The most significant under-expressed pathway operating in BMS was the POL-1 pathway (p = 4.0*10⁻⁵) known while suppressed to activate P53 dependent apoptosis and to suppress NFκB induced inflammation. In accordance, of the 30 P53 target genes presented within the BMS signature, 19 had expression direction consistent with P53 activation. The transcripts within the pathway include POL-1 transcription factor 3 (RRN3, p = 4.8*10⁻⁵), POL-1 polypeptide D (POLR1D, p = 2.2*10⁻⁴), leucine-rich PPR-motif containing protein (LRPPRC p = 2.3*10⁻⁵⁾, followed by suppression of the downstream family of ribosomal genes like RPL3, 6,13,22 and RPS6. In accordance POL-1 transcript and release factor PTRF that terminates POL-1 transcription, was over-expressed (p = 4.4*10⁻³). Verification of POL-1 pathway key genes was confirmed by qRT-PCR, and RRN3 silencing resulted in significant increase in the apoptosis level of PBMC sub-populations in RRMS patients. Our findings demonstrate that suppression of POL-1 pathway induce the low disease activity of BMS.</p> </div

Differential expression between BMS and RRMS.

<p>A. Volcano plot based on all microarray transcripts demonstrates global p value and Log2 fold change for each gene in differentiating between PBMC gene expression of patients with BMS and patients with RRMS. Red dots display over-expressed genes, blue dots display down-expressed genes. 406 MIGs, 171 gene over-expressed and 235 down-expressed, with p<0.01 and a log fold change between -3.1 to 3.3, are demonstrated above the black horizontal line. B. Principal component analysis (PCA) plot for microarray data showing the difference between BMS and RRMS blood gene expression. The three first principal components PC1, PC2 and PC3 are the linear combinations of the expressions of 406 MIGs plotted with the proportion of variance explained by each component, which covered 70.0% of total variance. The different ellipsoids plotted in 3-dimentional space show clear separation between BMS (violet dots, N = 31) and RRMS (green dots, BMS = 36) patients.</p

Effect of RRN3 silencing on apoptosis in RRMS.

<p>A. Comparison of apoptotic level in PBMC sub-populations between BMS (white bars) and RRMS (black bars) patients. A significantly higher percent of apoptotic CD19+ B cells and CD14+ macrophages is demonstrated in BMS patients. B. Apoptosis level in PBMC sub-populations of RRMS patients before and after RRN3 silencing. Percent of apoptotic cells was measured by PI staining.</p

POL-1 pathway related genes: BMS vs. RRMS.

<p>POL-1 pathway related genes: BMS vs. RRMS.</p

Modeling of Cognitive Impairment by Disease Duration in Multiple Sclerosis: A Cross-Sectional Study

<div><p>Background/Aims</p><p>Large-scale population studies measuring rates and dynamics of cognitive decline in multiple sclerosis (MS) are lacking. In the current cross-sectional study we evaluated the patterns of cognitive impairment in MS patients with disease duration of up to 30 years.</p><p>Methods</p><p>1,500 patients with MS were assessed by a computerized cognitive battery measuring verbal and non-verbal memory, executive function, visual spatial perception, verbal function, attention, information processing speed and motor skills. Cognitive impairment was defined as below one standard deviation (SD) and severe cognitive impairment as below 2SD for age and education matched healthy population norms.</p><p>Results</p><p>Cognitive performance in our cohort was poorer than healthy population norms. The most frequently impaired domains were information processing speed and executive function. MS patients with secondary-progressive disease course performed poorly compared with clinically isolated syndrome, relapsing-remitting and primary progressive MS patients. By the fifth year from disease onset, 20.9% of patients performed below the 1SD cutoff for impairment, p = 0.005, and 6.0% performed below the 2SD cutoff for severe cognitive impairment, p = 0.002. By 10 years from onset 29.3% and 9.0% of patients performed below the 1SD and 2SD cutoffs, respectively, p = 0.0001. Regression modeling suggested that cognitive impairment may precede MS onset by 1.2 years.</p><p>Conclusions</p><p>The rates of cognitive impairment in this large sample of MS patients were lower than previously reported and severe cognitive impairment was evident only in a relatively small group of patients. Cognitive impairment differed significantly from expected normal distribution only at five years from onset, suggesting the existence of a therapeutic window during which patients may benefit from interventions to maintain cognitive health.</p></div

Descriptive data for 1500 MS patients.

<p>P = p by ANOVA after Bonferroni correction for group comparison; p^a = p between CIS and SPMS; p^b = p between RRMS and SPMS; p^c = p between PPMS and SPMS. N = number; SE = standard error of the mean; CIS = clinically isolated syndrome; RRMS = relapsing-remitting multiple sclerosis; SPMS = secondary progressive multiple sclerosis; PPMS = primary progressive multiple sclerosis; EDSS- Expanded disability status scale; IMD – Immunomodulatory drugs.</p

Cognitive performance as a function of MS disease duration.

<p>Cognitive performance for MS patients with disease durations of 1 to 30 years (5-year intervals) with 95% confidence intervals for GCS (A) and individual cognitive domains (B–H), N = 1500.</p

MindStreams Global Assessment Battery (GAB): Description of cognitive domains tested and outcome parameters obtained.

<p>Index scores explanation for GAB cognitive tests.</p><p>1. MEMORY: mean accuracies for learning and delayed recognition phases of Verbal and Non-Verbal Memory tests.</p><p>2. EXECUTIVE FUNCTION: composite scores (accuracy divided by average response time) for interference phase of the Stroop test and Go-NoGo test, mean weighted accuracy for Catch Game.</p><p>3. VISUAL SPATIAL: mean accuracy for Visual Spatial Processing test.</p><p>4. VERBAL: weighted accuracy for verbal rhyming test (part of Verbal Function test).</p><p>5. ATTENTION: mean response times for the Go-NoGo test and a no interference phase of the Stroop test, mean response time for a low-load stage of Staged Information Processing test, mean standard deviation of response time for the Go-NoGo test, mean accuracy for a medium-load stage of Information Processing test.</p><p>6. INFORMATION PROCESSING: composite scores (accuracy divided by average response time) for various low- and medium-load stages of the Staged Information Processing test.</p><p>7. MOTOR SKILLS: mean time until first move for Catch Game, mean inter-tap interval and standard deviation of inter-tap interval for Finger Tapping test.</p