A rare P2X7 variant Arg307Gln with absent pore formation function protects against neuroinflammation in multiple sclerosis

Multiple sclerosis (MS) is a chronic relapsing-remitting inflammatory disease of the central nervous system characterized by oligodendrocyte damage, demyelination and neuronal death. Genetic association studies have shown a 2-fold or greater prevalence of the HLA-DRB1*1501 allele in the MS population compared with normal Caucasians. In discovery cohorts of Australasian patients with MS (total 2941 patients and 3008 controls), we examined the associations of 12 functional polymorphisms of P2X7, a microglial/macrophage receptor with proinflammatory effects when activated by extracellular adenosine triphosphate (ATP). In discovery cohorts, rs28360457, coding for Arg307Gln was associated with MS and combined analysis showed a 2-fold lower minor allele frequency compared with controls (1.11% for MS and 2.15% for controls, P = 0.0000071). Replication analysis of four independent European MS case-control cohorts (total 2140 cases and 2634 controls) confirmed this association [odds ratio (OR) = 0.69, P = 0.026]. A meta-analysis of all Australasian and European cohorts indicated that Arg307Gln confers a 1.8-fold protective effect on MS risk (OR = 0.57, P = 0.0000024). Fresh human monocytes heterozygous for Arg307Gln have >85% loss of 'pore' function of the P2X7 receptor measured by ATP-induced ethidium uptake. Analysis shows Arg307Gln always occurred with 270His suggesting a single 307Gln-270His haplotype that confers dominant negative effects on P2X7 function and protection against MS. Modeling based on the homologous zP2X4 receptor showed Arg307 is located in a region rich in basic residues located only 12 Å from the ligand binding site. Our data show the protective effect against MS of a rare genetic variant of P2RX7 with heterozygotes showing near absent proinflammatory 'pore' function.

Measurement of water-holding capacity in raw and freeze-dried broiler breast meat with visible and near-infrared spectroscopy

The feasibility of using visible/near-infrared spectroscopy (vis/NIR) to segregate broiler breast fillets by water-holding capacity (WHC) was determined. Broiler breast fillets (n = 72) were selected from a commercial deboning line based on visual color assessment. Meat color (L*a*b*), pH (2 and 24 h), drip loss, and salt-induced water uptake were measured. Reflectance measurements were recorded from 400 to 2,500 nm in both raw and freeze-dried breast meat samples. Raw and freeze-dried samples had similar spectra in the visible region (400-750 nm), but the freeze-dried samples exhibited numerous bands in the NIR region (750-2,500 nm) corresponding to muscle proteins and lipids that were not observed in the NIR spectra of the raw samples. Linear discriminate analyses were used to classify fillets as high-WHC or low-WHC according to predicted meat quality characteristics. Using the visible spectra (400-750 nm), fillets could be correctly classified into high-WHC and low-WHC groups based on drip loss and salt-induced water uptake with 88 to 92% accuracy in raw samples and 79 to 86% accuracy in freeze-dried samples. Using the NIR spectra (750-2,500 nm), fillets could be correctly classified into high-WHC and low-WHC groups with 74 to 76% accuracy in raw samples and 85 to 86% accuracy in freeze-dried samples. Thus, freeze-drying enhanced the accuracy of WHC classification using the NIR portion of the spectra. Data from this study demonstrate the potential for utilizing vis/NIR spectroscopy as a method for classifying broiler breast meat according to WHC.

Design and initial results from a kilojoule level Dense Plasma Focus with hollow anode and cylindrically symmetric gas puff

We have designed and built a Dense Plasma Focus (DPF) Z-pinch device using a kJ-level capacitor bank and a hollow anode, and fueled by a cylindrically symmetric gas puff. Using this device, we have measured peak deuteron beam energies of up to 400 keV at 0.8 kJ capacitor bank energy and pinch lengths of ∼6 mm, indicating accelerating fields greater than 50 MV/m. Neutron yields of on the order of 10(7) per shot were measured during deuterium operation. The cylindrical gas puff system permitted simultaneous operation of DPF with a radiofrequency quadrupole accelerator for beam-into-plasma experiments. This paper describes the machine design, the diagnostic systems, and our first results.

Predictors and dynamics of postpartum relapses in women with multiple sclerosis

Background:

Several studies have shown that pregnancy reduces multiple sclerosis (MS) relapses, which increase in the early postpartum period. Postpartum relapse risk has been predicted by pre-pregnancy disease activity in some studies.

Objective:

To re-examine effect of pregnancy on relapses using the large international MSBase Registry, examining predictors of early postpartum relapse.

Methods:

An observational case–control study was performed including pregnancies post-MS onset. Annualised relapse rate (ARR) and median Expanded Disability Status Scale (EDSS) scores were compared for the 24 months pre-conception, pregnancy and 24 months postpartum periods. Clustered logistic regression was used to investigate predictors of early postpartum relapses.

Results:

The study included 893 pregnancies in 674 females with MS. ARR (standard error) pre-pregnancy was 0.32 (0.02), which fell to 0.13 (0.03) in the third trimester and rose to 0.61 (0.06) in the first three months postpartum. Median EDSS remained unchanged. Pre-conception ARR and disease-modifying treatment (DMT) predicted early postpartum relapse in a multivariable model.

Conclusion:

Results confirm a favourable effect on relapses as pregnancy proceeds, and an early postpartum peak. Pre-conception DMT exposure and low ARR were independently protective against postpartum relapse. This novel finding could provide clinicians with a strategy to minimise postpartum relapse risk in women with MS planning pregnancy.

The Kurtzke EDSS rank stability increases 4 years after the onset of multiple sclerosis: results from the MSBase Registry

BACKGROUND

The Expanded Disability Status Scale (EDSS) is widely used to rate multiple sclerosis (MS) disability, but lack of disease duration information limits utility in assessing severity. EDSS ranking at specific disease durations was used to devise the MS Severity Score, which is gaining popularity for predicting outcomes. As this requires validation in longitudinal cohorts, we aimed to assess the utility of EDSS ranking as a predictor of 5-year outcome in the MSBase Registry.

METHODS

Rank stability of EDSS over time was examined in the MSBase Registry, a large multicentre MS cohort. Scores were ranked for 5-year intervals, and correlation of rank across intervals was assessed using Spearman's rank correlation. EDSS progression outcomes at 10 years were disaggregated by 5-year EDSS scores.

RESULTS

Correlation coefficients for EDSS rank over 5-year intervals increased with MS duration: years 1-6=0.55, years 4-9=0.74, years 7-12=0.80 and years 10-15=0.83. EDSS progression risk at 10 years after onset was highly dependent on EDSS at 5 years; one-point progression risk was greater for EDSS score of >2 than ≤2. Two-point progression was uncommon for EDSS score of <2 and more common at EDSS score of 4.

CONCLUSIONS

EDSS rank stability increases with disease duration, probably due to reduced relapses and less random variation in later disease. After 4 years duration, EDSS rank was highly predictive of EDSS rank 5 years later. Risk of progression by 10 years was highly dependent on EDSS score at 5 years duration. We confirm the utility of EDSS ranking to predict 5-year outcome in individuals 4 years after disease onset.

Adverse events of interferon beta-1a: a prospective multi-centre international ICH-GCP-based CRO-supported external validation study in daily practice

Background

Due to methodological shortcomings the available post-registration data on the adverse events (AEs) occurring in interferon beta-1a (INFb-1a)-treated patients fail to adequately validate phase III data and only partially inform on safety in daily practice. We assessed AEs in relapsing remitting multiple sclerosis (RRMS) patients treated with intramuscular (IM) INFb-1a in daily practice using data quality assurance measures similar to those in phase III trials.

Methods

A prospective, International Conference on Harmonization (ICH) - Good Clinical Practice (GCP)-based, clinical research organization (CRO)-supported study in 36 practices in the Netherlands, Belgium, the United Kingdom and Luxembourg. During 24 months after start of IM INFb-1a treatment 275 RRMS patients were assessed for AEs' severity (mild, moderate, severe) and relationship to treatment (not, unlikely, likely, definite). Data were compared with those reported in the pivotal phase III trial.

Findings

75.3% of the patients experienced one or more AEs that were likely or definitely related to INFb-1a. Of all AEs 40.5% were likely or definitely treatment-related; 68.5% of these were mild, and 3% severe. 6.6% of the patients discontinued treatment because of an AE. Compared to the pivotal phase III trial, we found statistically significantly lower incidences for most of the common AEs: headache, muscle ache, fatigue, fever, chills, nausea. One patient died following two cerebral vascular events in study month 22, both AEs were assessed as not related to INFb-1a.

Conclusion

Three out of four RRMS patients treated with IM INFb-1a in daily practice experience treatment-related AEs, most of these being mild. Our data externally validate the favorable phase III safety profile of IM INFb-1a and suggest that the real-life incidence of treatment-related AEs is less than reported in the pivotal phase III trial. Larger studies are needed to detect rare, potentially hazardous AEs of IM INFb-1a.

Locked-in, walked out

Locked in syndrome is typically associated with significant morbidity and mortality. We report a patient who had an unusually good recovery from locked in syndrome due to pontine infarction. The good recovery exhibited by our patient may have resulted from resolution of oedema at the site of infarction and brainstem plasticity being augmented by initial supportive measures in the intensive care unit and early, intensive rehabilitation.

Abdominal massage for the alleviation of constipation symptoms in people with multiple sclerosis: a randomized controlled feasibility study

BACKGROUND

Constipation affects many people with multiple sclerosis (MS), negatively impacting on their quality of life. The use of abdominal massage has been reported in several populations and has been shown to increase the frequency of defaecation.

OBJECTIVE

The objective of this study was to determine the feasibility of undertaking abdominal massage in people with MS.

METHODS

Following ethical approval, 30 patients with MS and constipation were recruited. After providing informed written consent and completion of baseline outcome measures, participants were randomly allocated to a massage group or a control group. The massage group participants were provided with advice on bowel management, and they or their carers were taught how to deliver abdominal massage and were recommended to perform it daily during the 4-week intervention period. The control group received bowel management advice only. Outcomes were measured pre (Week 0) and post treatment (Week 4), and at Week 8 and included: the Constipation Scoring System (CSS) (primary outcome), the Neurogenic Bowel Dysfunction Score, and a bowel diary.

RESULTS

Both groups demonstrated a decrease in CSS score from Week 0 to Week 4, indicating an improvement in constipation symptoms; however, the massage group improved significantly more than the control groups (mean difference between groups in score change -5.0 (SD 1.5), 95% CI -8.1, -1.8; t = -3.28, df = 28, p = 0.003).

CONCLUSION

The results of this small study suggest a positive effect of the intervention on the symptoms of constipation, and support the feasibility of a substantive trial of abdominal massage for the alleviation of the symptoms of constipation in people with MS.

Genetic polymorphisms, their allele combinations and IFN-beta treatment response in Irish multiple sclerosis patients

INTRODUCTION

IFN-beta is widely used as first-line immunomodulatory treatment for multiple sclerosis. Response to treatment is variable (30-50% of patients are nonresponders) and requires a long treatment duration for accurate assessment to be possible. Information about genetic variations that predict responsiveness would allow appropriate treatment selection early after diagnosis, improve patient care, with time saving consequences and more efficient use of resources.

MATERIALS & METHODS

We analyzed 61 SNPs in 34 candidate genes as possible determinants of IFN-beta response in Irish multiple sclerosis patients. Particular emphasis was placed on the exploration of combinations of allelic variants associated with response to therapy by means of a Markov chain Monte Carlo-based approach (APSampler).

RESULTS

The most significant allelic combinations, which differed in frequency between responders and nonresponders, included JAK2-IL10RB-GBP1-PIAS1 (permutation p-value was p(perm) = 0.0008), followed by JAK2-IL10-CASP3 (p(perm) = 0.001).

DISCUSSION

The genetic mechanism of response to IFN-beta is complex and as yet poorly understood. Data mining algorithms may help in uncovering hidden allele combinations involved in drug response versus nonresponse.

The MHC2TA-168A/G and +1614G/C polymorphisms and risk for multiple sclerosis or chronic inflammatory arthropathies

The -168A-G polymorphism has been shown to influence transcription of the MHC2TA gene and has been implicated in several inflammatory/autoimmune disorders. Attempts to reproduce these findings have been inconclusive. We investigated the role of this promoter single nucleotide polymorphism (SNP) in 440 multiple sclerosis (MS), 293 rheumatoid arthritis (RA), 74 juvenile idiopathic arthritis (JIA) patients and 316 healthy controls from Northern Ireland. We also genotyped a non-synonymous SNP in exon 11, +1614G/C. There was no significant difference in the -168G allele frequencies and carriage rates in the separate RA, JIA, or MS collections compared with the control group [odds ratio (OR) = 1.1, 95% confidence intervals (CI) = 0.86-1.44; OR = 1.1, 95% CI = 0.75-1.68; OR = 1.1, 95% CI = 0.84-1.35, respectively]. Assessment of the common phenotype (chronic inflammatory disease; n = 807 vs 316 controls) was negative as well. Carriage of +1614C was protective against JIA (OR = 0.6, 95% CI = 0.3-1.0) and showed a similar trend in RA and MS (OR = 0.7, 95% CI = 0.5-1.0; OR = 0.8, 95% CI = 0.6-1.0, respectively). The common phenotype (chronic inflammatory disease) was also significant (OR = 0.7, 95% CI = 0.6-1.0).

CTLA4 gene polymorphisms and multiple sclerosis in Northern Ireland

Four CTLA4 polymorphisms were investigated in a Northern Irish collection of relapsing-remitting (RR) and primary-progressive (PP) multiple sclerosis (MS) patients. The CTLA4 promoter (-318 C/T), exon 1 (+49 A/G) and intergenic CT60 SNPs, as well as a microsatellite found in the 3' UTR (AT(n)) were analysed in 246 RRMS, 84 PPMS and 158 healthy controls. The A allele of the exon 1 +49 A/G SNP (OR=1.36; 95% CI=1.11-1.81; P=0.038), and more so the AA genotype (OR=1.70; 95% CI=1.11-2.60; P=0.015) were associated with RR, but not PPMS. In the PPMS population, overall allele distribution of the AT(n) microsatellite was significantly different from that in the healthy controls. We did not find any association with the promoter (-318 C/T) or intergenic CT60 SNPs in either of the disease cohorts. In concordance with several recent studies, we detected a trend toward higher carriage rates of the +49 G allele in PP vs RR MS patients (66.7% vs 58.9%), though this was not significant. Our data highlight the CTLA4 +49 A/G and 3'UTR polymorphisms as potential modifiers of disease course in MS.

Determination of genetic factors influencing susceptibility to disease and response to interferon-B in multiple sclerosis (131.16)

Treatment strategies of multiple sclerosis (MS) aim to slow progression of the disease and provide symptomatic relief. Interferon B (IFN B) is the most prominent disease modifying drug used in the treatment of MS. It has been shown to decrease relapse rates and delay progression of the disease. There are currently three proprietary IFN B products on the market; Avonex and Rebif (IFN B1a), and Betaferon (IFN B1b). Despite demonstrated efficacy, these products are not without their problems. There is considerable variation in response, with an estimated 30–50% of patients showing treatment failure, and high treatments costs. In essence, treatment is on a trial and error basis. To date there is no method of treatment outcome prediction at onset of treatment. In this study we have screened approximately 60 polymorphisms in over 30 candidate response genes, based on notions of their known function and the literature. We selected SNPs in the promoter region, hypothesising that polymorphisms may modify IFN inducibility. Additionally non-synonymous SNPs and those potentially affecting splicing, were also selected. Polymorphisms were typed in DNA samples from 260 Irish patients classified as responders or non-responders. A cohort of 120 healthy controls was also included in the study to determine whether these SNPs influenced susceptibility to MS.

The neuropeptide genes TAC1, TAC3, TAC4, VIP and PACAP(ADCYAP1), and susceptibility to multiple sclerosis

The related immunomodulatory neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylyl cyclase activating peptide (PACAP; gene symbol ADCYAP1) have recently been proposed as novel therapeutics for the treatment of multiple sclerosis (MS). These neuropeptides, as well as those belonging to the tachykinin family exert pleiotropic effects, many of which are of relevance to central nervous system inflammation. In the present study, we have analysed 14 single nucleotide polymorphisms (SNPs) and 4 microsatellite markers in the VIP, ADCYAP1, TAC3 and TAC4 genes for susceptibility to MS in a case-control collection from Northern Ireland. Following correction for multiple comparisons, we did not find any significant associations between single polymorphic markers or multiple-marker haplotypes and susceptibility to MS. Furthermore, we analysed 2 SNPs in the TAC1 gene in a set of Sardinian trio MS families, based on our previous observation of association of these SNPs with MS in the Northern Irish (Genes Immun. 2005, 6, 265-270). Analysis of these SNPs in the Sardinians was not significant though a similar trend to that originally observed in the Northern Irish was present. Meta-analysis of the Sardinian and Northern Irish TAC1 SNP genotype data revealed a Mantel-Haenszel Common OR Estimate for the TAC1 intron 1 SNP rs2072100 of 0.76 (95% CI 0.63-0.92; P=0.005; A allele) and for the TAC1 promoter SNP rs7793277 of 0.76 (95% CI 0.615-0.95; P=0.014; C allele). Our data advocate a need for further exploration of the TAC1 gene region in MS.

Eucalyptus gunnii CCR and CAD2 promoters are active in lignifying cells during primary and secondary xylem formation in Arabidopsis thaliana

Cell-specific expression patterns of the Eucalyptus gunnii cinnamoyl coenzymeA reductase (EgCCR) and cinnamyl alcohol dehydrogenase (EgCAD2) promoters were analyzed by promoter-GUS histochemistry in the primary and secondary xylem tissues from floral stems and roots of Arabidopsis thaliana. Expression patterns indicated that the EgCCR and EgCAD2 genes were expressed in a coordinated manner in primary and secondary xylem tissues of the Arabidopsis floral stem and root. Both genes were expressed in all lignifying cells (vessel elements, xylem fibers and paratracheal parenchyma cells) of xylem tissues. The capacity for long-term monolignol production appeared to be related to the cell-specific developmental processes and biological roles of different cell types. Our results suggested that lignification of short-lived vessel elements was achieved by a two-step process involving (i) monolignol production by vessel elements prior to vessel programmed cell death and (ii) subsequent monolignol production by vessel-associated living paratracheal parenchyma cells following vessel element cell death. EgCCR and EgCAD2 gene expression patterns suggested that the process of xylem cell lignification was similar in both primary and secondary xylem tissues in Arabidopsis floral stems and roots.

Linkage disequilibrium screening for multiple sclerosis implicates JAG1 and POU2AF1 as susceptibility genes in Europeans

By combining all the data available from the Genetic Analysis of Multiple sclerosis in EuropeanS (GAMES) project, we have been able to identify 17 microsatellite markers showing consistent evidence for apparent association. As might be expected five of these markers map within the Major Histocompatibility Complex (MHC) and are in LD with HLA-DRB1. Individual genotyping of the 12 non-MHC markers confirmed association for three of them--D11S1986, D19S552 and D20S894. Association mapping across the candidate genes implicated by these markers in 937 UK trio families revealed modestly associated haplotypes in JAG1 (p=0.019) on chromosome 20p12.2 and POU2AF1 (p=0.003) on chromosome 11q23.1.

Germin-like genes are expressed during somatic embryogenesis and early development of conifers

Germins and germin-like proteins (GLPs) are members of a superfamily of proteins widely distributed in plants. Their localization within the extracellular matrix and in some cases their hydrogen peroxide-producing activity suggests that these proteins are involved in cell wall metabolism during stress responses and developmental processes. Several very highly conserved conifer GLPs have been identified in somatic embryo tissues. In order to gain more knowledge on their potential involvement in the development of this particular tissue, we have characterized a new GLP gene, LmGER1 in hybrid larch. Anti-GLP immunserum and in-gel activity analyses suggested the presence of superoxide dismutase activity in apoplastic proteins from larch somatic embryos. These results could indicate a possible role for LmGER1 in this physiological process. The expression of LmGER1 has been followed during the maturation of somatic embryos and in different organs of young plantlets by homologous transformation with a promoter-gus construct. This promoter was activated in the root cap of young embryos and, later on, in the cotyledons and in the vascular procambium and xylem. Furthermore, the importance of this gene in embryo development was evaluated by transforming embryonal masses with a gene construct encoding a hairpin RNA leading to gene silencing. The potential role of LmGER1 in cross-linking of cell wall components is discussed.

Pharmacogenomics of responsiveness to interferon IFN-beta treatment in multiple sclerosis: a genetic screen of 100 type I interferon-inducible genes

OBJECTIVES

Interferon IFN-beta is indicated for the treatment of multiple sclerosis. A significant proportion of patients show a poor clinical response to therapy. Type I interferon exerts its effect at least partially through interaction of specific transcription factors with interferon-stimulated response elements (ISREs), mostly located in promoter regions of its target genes. We hypothesized that polymorphisms may occur within or close to ISRE elements, altering type I interferon inducibility and ultimately leading to a modified clinical response in carriers.

METHODS

We selected 100 ISRE-containing genes and sequenced their promoter regions in small genomic deoxyribonucleic acid pools of responding and nonresponding patients, as well as healthy control subjects. A selection of polymorphisms discovered by this approach was scrutinized subsequently in a collection of individual deoxyribonucleic acid samples.

RESULTS

We identified 4 genes containing polymorphisms associated with response to recombinant IFN-beta: IFNAR1 (P = .036), LMP7 (P = .002; odds ratio [OR], 6.37 [95% confidence interval (CI), 1.84-24.1]), CTSS (P = .02; OR, 0.38 [95% CI, 0.18-0.84]), and MxA (P = .015; OR, 3.37 [95% CI, 1.11-11.4]). Logistic regression analysis with treatment outcome used as the dependent variable and genotype as the independent variable revealed 2 genes, LMP7 (OR, 0.55 [95% CI, 0.34-0.89]) and MxA (OR, 0.41 [95% CI, 0.19-0.88]), that were independently associated with treatment response.

CONCLUSIONS

Our work confirms and extends previous indications for a polygenic mechanism involved in bringing about responsiveness to recombinant IFN-beta. The identification of 2 genes active in the antigen processing and presentation cascade; that is, LMP7, coding for the proteasome subunit beta, and CTSS, coding for cathepsin S; as potential response modifiers may identify this pathway as being of particular relevance to phenotypic expression of response heterogeneity.