calpastatin and Multiple-Sclerosis

To identify promising candidate genes linked to interindividual differences in the efficacy of interferon beta therapy. Recombinant interferon beta therapy is widely used to reduce disease activity in multiple sclerosis (MS). However, up to 50% of patients continue to have relapses and worsening disability despite therapy.. We used a genome-wide pharmacogenomic approach to identify single-nucleotide polymorphism (SNP) allelic differences associated with interferon beta therapy response.. Four collaborating centers in the Mediterranean Basin. Data Coordination Center at the University of California, San Francisco.. A cohort of 206 patients with relapsing-remitting MS followed up prospectively for 2 years after initiation of treatment.. DNA was pooled and hybridized to Affymetrix 100K GeneChips. Pooling schemes were designed to minimize confounding batch effects and increase confidence by technical replication.. Single-nucleotide polymorphism detection. Comparison of allelic frequencies between good responders and nonresponders to interferon beta therapy.. A multianalytical approach detected significant associations between several SNPs and treatment response, which were validated by individual DNA genotyping on an independent platform. After the validation stage was complete, 81 additional individuals were added to the analysis to increase power. We found that responders and nonresponders had significantly different genotype frequencies for SNPs located in many genes, including glypican 5, collagen type XXV alpha1, hyaluronan proteoglycan link protein, calpastatin, and neuronal PAS domain protein 3.. The reported results address the question of genetic heterogeneity in MS and the response to immunotherapy by analysis of the correlation between different genotypes and clinical response to interferon beta therapy. Many of the detected differences between responders and nonresponders were genes associated with ion channels and signal transduction pathways. The study also suggests that genetic variants in heparan sulfate proteoglycan genes may be of clinical interest in MS as predictors of the response to therapy. In addition to new insights into the mechanistic biology of interferon beta, these results help define the molecular basis of interferon beta therapy response heterogeneity.

Topics: Adult; Basic Helix-Loop-Helix Transcription Factors; Calcium-Binding Proteins; Cohort Studies; Collagen Type XIII; Extracellular Matrix Proteins; Female; Genome; Glypicans; Humans; Immunologic Factors; Interferon-beta; Male; Multiple Sclerosis; Nerve Tissue Proteins; Oligonucleotide Array Sequence Analysis; Pharmacogenetics; Polymorphism, Single Nucleotide; Proteoglycans; Transcription Factors

While multiple molecular mechanisms contribute to midbrain nigrostriatal dopaminergic degeneration in Parkinson's disease (PD), the mechanism of damage in non-dopaminergic sites within the central nervous system, including the spinal cord, is not well-understood. Thus, to understand the comprehensive pathophysiology underlying this devastating disease, postmortem spinal cord tissue samples (cervical, thoracic, and lumbar segments) from patients with PD were analyzed compared to age-matched normal subjects or Alzheimer's disease for selective molecular markers of neurodegeneration and inflammation. Distal axonal degeneration, relative abundance of both sensory and motor neuron death, selective loss of ChAT(+) motoneurons, reactive astrogliosis, microgliosis, increased cycloxygenase-2 (Cox-2) expression, and infiltration of T cells were observed in spinal cord of PD patients compared to normal subjects. Biochemical analyses of spinal cord tissues revealed associated inflammatory and proteolytic events (elevated levels of Cox-2, expression and activity of μ- and m-calpain, degradation of axonal neurofilament protein, and concomitantly low levels of endogenous inhibitor - calpastatin) in spinal cord of PD patients. Thus, pathologically upregulated calpain activity in spinal cords of patients with PD may contribute to inflammatory response-mediated neuronal death, leading to motor dysfunction. We proposed calpain over-activation and calpain-calpastatin dysregulation driving in a cascade of inflammatory responses (microglial activation and T cell infiltration) and degenerative pathways culminating in axonal degeneration and neuronal death in spinal cord of Parkinson's disease patients. This may be one of the crucial mechanisms in the degenerative process.

Topics: Alzheimer Disease; Axons; Calcium-Binding Proteins; Calpain; Case-Control Studies; Cell Death; Cytoskeletal Proteins; Gliosis; Humans; Huntington Disease; Inflammation; Multiple Sclerosis; Nerve Degeneration; Neurons; Parkinson Disease; Spinal Cord; T-Lymphocytes

In autoimmune demyelinating diseases such as multiple sclerosis (MS), the degradation of myelin proteins results in destabilization of the myelin sheath. Thus, proteases have been implicated in myelin protein degradation, and recent studies have demonstrated increased expression and activity of a calcium-activated neutral proteinase (calpain) in experimental allergic encephalomyelitis, the corresponding animal model of MS. In the present study, calpain activity and expression (at translational and transcriptional levels) were evaluated in white matter from human patients with MS and Parkinson's and Alzheimer's diseases and compared with that of white matter from normal controls. Western blot analysis revealed that levels of the active form of calpain and calpain-specific degradation products (fodrin) were increased by 90.1% and 52.7%, respectively, in MS plaques compared with normal white matter. Calpain translational expression was up-regulated by 462.5% in MS plaques compared with controls, although levels of the specific endogenous inhibitor, calpastatin, were not altered significantly. At the transcriptional level, no significant changes in calpain or calpastatin expression were detected by reverse transcription-PCR. Using double immunofluorescent labeling, increased calpain expression was observed in reactive astrocytes, activated T cells, and activated mononuclear phagocytes in and adjacent to demyelinating lesions. Calpain activity and translational expression were not increased significantly in white matter from patients with Parkinson's or Alzheimer's diseases compared with that of normal controls. Because calpain degrades all major myelin proteins, the increased activity and expression of this proteinase may play a critical role in myelinolysis in autoimmune demyelinating diseases such as MS.

Topics: Calcium; Calcium-Binding Proteins; Calpain; Demyelinating Diseases; Fluorescent Antibody Technique; Humans; Multiple Sclerosis; Protein Biosynthesis; Transcription, Genetic