Tamar Paperna

Pharmacogenetics of glatiramer acetate therapy for multiple sclerosis reveals drug-response markers.

Genetic-based optimization of treatment prescription is becoming a central research focus in the management of chronic diseases, such as multiple sclerosis, which incur a prolonged drug-regimen adjustment. This study was aimed to identify genetic markers that can predict response to glatiramer acetate (Copaxone) immunotherapy for relapsing multiple sclerosis. For this purpose, we genotyped fractional cohorts of two glatiramer acetate clinical trials for HLA-DRB1*1501 and 61 single nucleotide polymorphisms within a total of 27 candidate genes. Statistical analyses included single nucleotide polymorphism-by-single nucleotide polymorphism and haplotype tests of drug-by-genotype effects in drug-treated versus placebo-treated groups. We report the detection of a statistically significant association between glatiramer acetate response and a single nucleotide polymorphism in a T-cell receptor &bgr; (TRB@) variant replicated in the two independent cohorts (odds ratio=6.85). Findings in the Cathepsin S (CTSS) gene (P=0.049 corrected for all single nucleotide polymorphisms and definitions tested, odds ratio=11.59) in one of the cohorts indicate a possible association that needs to be further investigated. Additionally, we recorded nominally significant associations of response with five other genes, MBP, CD86, FAS, IL1R1 and IL12RB2, which are likely to be involved in glatiramer acetates mode-of-action, both directly and indirectly. Each of these association signals in and of itself is consistent with the no-association null-hypothesis, but the number of detected associations is surprising vis-à-vis chance expectation. Moreover, the restriction of these associations to the glatiramer acetate-treated group, rather than the placebo group, clearly demonstrates drug-specific genetic effects. These findings provide additional progress toward development of pharmacogenetics-based personalized treatment for multiple sclerosis.

Internet usage by patients with multiple sclerosis: implications to participatory medicine and personalized healthcare.

Online health information and services for patients were suggested to improve symptom management and treatment adherence, thereby contributing to healthcare optimization. This paper aimed to characterize multiple sclerosis (MS) patients Internet usage. Information regarding browsing habits, Internet reliability, and the medical teams attitude to information collected online was obtained by questionnaires from MS patients. Data was compared between nonbrowsers, browsers on MS topics, and browsers on non-MS topics only. From the 96 patients recruited, 61 (63.5%) performed MS-related searches. The most viewed topics were “understanding the disease” and “treatments”. Patients reported that the information helped coping with MS and assured them of the appropriateness of their therapy. Shorter disease duration was correlated with higher Internet activity. Disabled patients were more interested in online interaction with specialists and support groups. This paper suggests that MS patients benefit from online information, and it emphasizes the importance of resources tailored to patients needs.

Androgen receptor CAG repeat length in Jewish Israeli women who are BRCA1/2 mutation carriers: association with breast/ovarian cancer phenotype

BRCA1/2 mutation carriers are at an increased risk for developing breast and/or ovarian cancer. Yet, the genetic and environmental factors that govern the phenotypic expression of mutant BRCA1/2 alleles remain elusive. The CAG repeat within exon 1 of the androgen receptor (AR) gene is reportedly associated with breast cancer phenotype in BRCA1 mutation carriers. Two hundred and twenty seven BRCA1/2 mutation carriers were genotyped for the polymorphic AR CAG repeat, and allele size was correlated with breast/ovarian cancer morbidity parameters. Of 227 BRCA1/2 carriers, 169 were BRCA1 mutation carriers and 58 carried a BRCA2 mutation, 149 had breast and/or ovarian cancer and 78 were asymptomatic mutation carriers. The mean age at diagnosis in women with either or both neoplasms was 46.7±11.2 years, and that of the asymptomatic group – 45.8±9.4 years, a statistically insignificant difference. The AR CAG repeat ranged from eight to 28 in all tested women, and the mean number of the repeats were not statistically different between affected (18.3±2.4) and asymptomatic mutation carriers (18.6±2.1). The AR CAG repeat among patients with early onset (<42 years) breast cancer was significantly shorter (17.5±2.3) compared with asymptomatic individuals (18.6±2.1) (P<0.01), and the shorter allele – the younger the age at diagnosis. There is no conclusive evidence of association between AR CAG repeat size and breast or ovarian cancer risk in Jewish BRCA1/2 mutation carriers. A small effect of a short AR CAG allele size on breast cancer at early age (<42 years) cannot be excluded.

The ubiquitin–proteasome pathway regulates claudin 5 degradation

The tight junctions (TJs) form continuous intracellular contacts, which help create selective barriers in epithelial and endothelial cell layers. The structures created by the TJs are very dynamic and can be rapidly remodeled in response to physiological and pathological signals. Claudin 5 is a membranal TJ protein which plays a critical role in determining the permeability of endothelial barriers. We describe the regulation of claudin 5 degradation by the ubiquitin–proteasome system (UPS). Our results indicate that claudin 5 has a relatively short half‐life and can be polyubiquitinated on lysine 199. This ubiquitination appears to trigger the proteasome‐dependent degradation of claudin 5. Other mechanisms also seem to be involved in the post‐translational regulation of claudin 5, including a ubiquitin‐independent and probably indirect lysosomal‐dependent pathway. These findings provide evidence for the involvement of the UPS in the regulation of claudin 5 levels, and set the stage for further research to determine the involvement of this pathway in the modulation of the properties of TJs and cell‐layer barriers. J. Cell. Biochem. 113: 2415–2423, 2012.

Cathepsins and their endogenous inhibitors cystatins: expression and modulation in multiple sclerosis.

Cathepsins are involved in a variety of physiological processes including antigen processing and presentation and extracellular matrix degradation. In the present study, we evaluated whether expression levels of cathepsins S and B and their inhibitors cystatins B and C are affected by multiple sclerosis (MS) disease state (relapse and remission) and therapies (interferon‐β[IFN‐β] and the glucocorticoid [GC] methylprednisolone), and whether they are associated with the IFN‐β response phenotype. Real‐time PCR was employed to compare RNA expression levels in peripheral blood leucocytes (PBLs) and ELISA to determine serum protein levels of MS patients and matched healthy individuals. Cathepsin S RNA was higher in MS patients in the relapse state compared to controls (by 74%, P= 3 × 10−5, n= 30 versus n= 18) with a similar increase observed in serum (66%, P= 0.002, n= 18 versus n= 20). GC treatment reduced cathepsin S levels in PBL RNA (by 44%, P= 6 × 10−6, n= 27) and serum proteins (by 27%, P= 1 × 10−5, n= 26), reduced the serum protein levels of pro‐cathepsin B (by 8%, P= 0.0007, n= 23), and in parallel increased the serum levels of their inhibitor cystatin C (by 82%, P= 8 × 10−6, n= 26). IFN‐β therapy significantly elevated the RNA levels (n= 16) of cathepsin B (by 16%, P= 0.03), cystatin B (44%, P= 0.004) and cystatin C (48%, P= 0.011). In the serum, only cathepsin S levels were reduced by IFN‐β (16%, P= 0.006, n= 25). Interestingly, pre‐treatment serum cathepsin S/cystatin C ratio was higher in ‘good responders’ to IFN‐β therapy compared to patients without a good response (by 94%, P= 0.003). These results suggest that cathepsin S and cystatin C may contribute to disease activity in MS, specifically in a subgroup of patients that are responsive to IFN‐β therapy, and that these proteins should be further evaluated as biomarkers in MS.

Chronotherapy using corticosteroids for multiple sclerosis relapses

Background: The activity of the immune system displays a circadian rhythm. In diseases characterised by aberrant immune activity, chronotherapy (a treatment regimen tailored to diurnal body rhythms) may increase the efficiency, safety and tolerability of drugs. Aim: To compare the outcomes of intravenous corticosteroid administration during the day or night, for treatment of acute multiple sclerosis relapses. Methods: 17 patients with multiple sclerosis were included in the study. Clinical assessment of disability was performed at trial entry, and at days 7 and 30 from the initiation of treatment. Adverse events and preference of night-time versus daytime treatment were assessed at the end of the treatment course. Results: After night-time treatment, clinical recovery was significantly (p<0.001) enhanced and the mean number of side effects was significantly (p = 0.007) lower. Furthermore, most patients expressed a preference for night-time versus daytime treatment. Conclusions: The study suggests a potential benefit for implementation of chronotherapy using steroid treatment for acute multiple sclerosis relapse, with implications for other immune-mediated disorders.

Tight junction proteins expression and modulation in immune cells and multiple sclerosis

The tight junction proteins (TJPs) are major determinants of endothelial cells comprising physiological vascular barriers such as the blood–brain barrier, but little is known about their expression and role in immune cells. In this study we assessed TJP expression in human leukocyte subsets, their induction by immune activation and modulation associated with autoimmune disease states and therapies. A consistent expression of TJP complexes was detected in peripheral blood leukocytes (PBLs), predominantly in B and T lymphocytes and monocytes, whereas the in vitro application of various immune cell activators led to an increase of claudin 1 levels, yet not of claudin 5. Claudins 1 and 5 levels were elevated in PBLs of multiple sclerosis (MS) patients in relapse, relative to patients in remission, healthy controls and patients with other neurological disorders. Interestingly, claudin 1 protein levels were elevated also in PBLs of patients with type 1 diabetes (T1D). Following glucocorticoid treatment of MS patients in relapse, RNA levels of JAM3 and CLDN5 and claudin 5 protein levels in PBLs decreased. Furthermore, a correlation between CLDN5 pre‐treatment levels and clinical response phenotype to interferon‐β therapy was detected. Our findings indicate that higher levels of leukocyte claudins are associated with immune activation and specifically, increased levels of claudin 5 are associated with MS disease activity. This study highlights a potential role of leukocyte TJPs in physiological states, and autoimmunity and suggests they should be further evaluated as biomarkers for aberrant immune activity and response to therapy in immune‐mediated diseases such as MS.

Interferon-beta induces distinct gene expression response patterns in human monocytes versus T cells.

Background Monocytes, which are key players in innate immunity, are outnumbered by neutrophils and lymphocytes among peripheral white blood cells. The cytokine interferon-β (IFN-β) is widely used as an immunomodulatory drug for multiple sclerosis and its functional pathways in peripheral blood mononuclear cells (PBMCs) have been previously described. The aim of the present study was to identify novel, cell-specific IFN-β functions and pathways in tumor necrosis factor (TNF)-α-activated monocytes that may have been missed in studies using PBMCs. Methodology/Principal Findings Whole genome gene expression profiles of human monocytes and T cells were compared following in vitro priming to TNF-α and overnight exposure to IFN-β. Statistical analyses of the gene expression data revealed a cell-type-specific change of 699 transcripts, 667 monocyte-specific transcripts, 21 T cell-specific transcripts and 11 transcripts with either a difference in the response direction or a difference in the magnitude of response. RT-PCR revealed a set of differentially expressed genes (DEGs), exhibiting responses to IFN-β that are modulated by TNF-α in monocytes, such as RIPK2 and CD83, but not in T cells or PBMCs. Known IFN-β promoter response elements, such as ISRE, were enriched in T cell DEGs but not in monocyte DEGs. The overall directionality of the gene expression regulation by IFN-β was different in T cells and monocytes, with up-regulation more prevalent in T cells, and a similar extent of up and down-regulation recorded in monocytes. Conclusions By focusing on the response of distinct cell types and by evaluating the combined effects of two cytokines with pro and anti-inflammatory activities, we were able to present two new findings First, new IFN-β response pathways and genes, some of which were monocytes specific; second, a cell-specific modulation of the IFN-β response transcriptome by TNF-α.

Opposing effects of the HLA-DRB1*0301-DQB1*0201 haplotype on the risk for multiple sclerosis in diverse Arab populations in Israel.

Different multiple sclerosis (MS) prevalence rates were reported for Muslim and Christian Arabs in Israel. In this study, we evaluated whether associations of human leukocyte antigen (HLA) genes with MS may contribute to this prevalence difference. DNA samples from Israeli Arab MS patients (n=109) and controls (n=132) were typed for HLA class I (HLA-A, -B and -C) and II (HLA-DRB1 and -DQB1) genes. Global comparisons of HLA allele frequencies revealed significant differences between Christians and Muslims; therefore, case–control analyses were stratified by religious affiliation. Disease characteristics of Muslim and Christian Arab MS patients were similar to those reported for European populations. Opposing association signals with MS were observed for alleles composing the DRB1*0301-DQB1*0201 haplotype: positive association of the HLA-DRB1*0301 allele in Muslims (PBonferroni=0.004, odds ratio (OR)=3.07), and negative association in Christian Arabs (PBonferroni=0.01, OR=0.12), with similar results obtained for HLA-DQB1*0201. HLA-B*52 was negatively associated with MS only in Muslims (PBonferroni=0.01, OR=0.03). The study presents for the first time a high-resolution HLA gene analysis in clinically well-characterized Arab populations with MS, and shows the population-specific contribution of the DRB1*0301-DQB1*0201 haplotype to disease susceptibility.

Immunomodulation by chronobiologically-based glucocorticoids treatment for multiple sclerosis relapses

This study compares the effects of daytime versus nighttime intravenous glucocorticoid treatment of multiple sclerosis (MS) relapses for several immune indicators. The levels of serum CRP, TNFalpha, ESR, MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined at trial entry and at day 7 post therapy initiation in 35 MS patients. Serum MMP-9 protein levels were differentially affected by treatment regimen, and were significantly lower after nighttime treatment. Both treatment protocols led to a similar reduction of ESR, CRP and TNFalpha. These findings provide preliminary characterization of biomarkers in the application of chronobiology-based glucocorticoid therapeutics in MS and other immune disorders.