Differential brain and spinal cord cytokine and BDNF levels in experimental autoimmune encephalomyelitis are modulated by prior and regular exercise

The interactions between a prior program of regular exercise and the development of experimental autoimmune encephalomyelitis (EAE)-mediated responses were evaluated. in the exercised EAE mice, although there was no effect on infiltrated cells, the cytokine and derived neurotrophic factor (BDNF) levels were altered, and the clinical score was attenuated. Although, the cytokine levels were decreased in the brain and increased in the spinal cord, BDNF was elevated in both compartments with a tendency of lesser demyelization volume in the spinal cord of the exercised EAE group compared with the unexercised. (C) 2013 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)NIHUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Fisiol & Biofis, Nucleo Neurociencias, BR-31270901 Belo Horizonte, MG, BrazilMinist Educ Brazil, CAPES Fdn, Programa Pos Grad Ciencias Biol Fisiol Farmacol, BR-70040020 Brasilia, DF, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Patol, BR-31270901 Belo Horizonte, MG, BrazilUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilUniv Fed Minas Gerais, Inst Ciencias Biol, Dept Bioquim & Imunol, Lab Venenos & Toxinas Anim, BR-31270901 Belo Horizonte, MG, BrazilUniv Miami, Miller Sch Med, Miami Project Cure Paralysis, Miami, FL 33136 USALa Trobe Univ, Dept Biochem, Bundoora, Vic 3086, AustraliaUniversidade Federal de São Paulo, Dept Biofis, BR-04023062 São Paulo, BrazilCAPES: BEX 0020/12-5NIH: NS051709NIH: NS065479FAPEMIG: CBB-APQ-01459-10FAPEMIG: PPM-00200-12Web of Scienc

Computational Characterization of 3′ Splice Variants in the GFAP Isoform Family

Glial fibrillary acidic protein (GFAP) is an intermediate filament (IF) protein specific to central nervous system (CNS) astrocytes. It has been the subject of intense interest due to its association with neurodegenerative diseases, and because of growing evidence that IF proteins not only modulate cellular structure, but also cellular function. Moreover, GFAP has a family of splicing isoforms apparently more complex than that of other CNS IF proteins, consistent with it possessing a range of functional and structural roles. The gene consists of 9 exons, and to date all isoforms associated with 3′ end splicing have been identified from modifications within intron 7, resulting in the generation of exon 7a (GFAPδ/ε) and 7b (GFAPκ). To better understand the nature and functional significance of variation in this region, we used a Bayesian multiple change-point approach to identify conserved regions. This is the first successful application of this method to a single gene – it has previously only been used in whole-genome analyses. We identified several highly or moderately conserved regions throughout the intron 7/7a/7b regions, including untranslated regions and regulatory features, consistent with the biology of GFAP. Several putative unconfirmed features were also identified, including a possible new isoform. We then integrated multiple computational analyses on both the DNA and protein sequences from the mouse, rat and human, showing that the major isoform, GFAPα, has highly conserved structure and features across the three species, whereas the minor isoforms GFAPδ/ε and GFAPκ have low conservation of structure and features at the distal 3′ end, both relative to each other and relative to GFAPα. The overall picture suggests distinct and tightly regulated functions for the 3′ end isoforms, consistent with complex astrocyte biology. The results illustrate a computational approach for characterising splicing isoform families, using both DNA and protein sequences

Cerebellar pathology in multiple sclerosis and experimental autoimmune encephalomyelitis: current status and future directions

Recent decades have witnessed significant progress in understanding mechanisms driving neurodegeneration and disease progression in multiple sclerosis (MS), but with a focus on the cerebrum. In contrast, there have been limited studies of cerebellar disease, despite the common occurrence of cerebellar symptoms in this disorder. These rare studies, however, highlight the early cerebellar involvement in disease development and an association between the early occurrence of cerebellar lesions and risk of worse prognosis. In parallel developments, it has become evident that far from being a region specialized in movement control, the cerebellum plays a crucial role in cognitive function, via circuitry connecting the cerebellum to association areas of the cerebrum. This complexity, coupled with challenges in imaging of the cerebellum have been major obstacles in the appreciation of the spatio-temporal evolution of cerebellar damage in MS and correlation with disability and progression. MS studies based on animal models have relied on an induced neuroinflammatory disease known as experimental autoimmune encephalomyelitis (EAE), in rodents and non-human primates (NHP). EAE has played a critical role in elucidating mechanisms underpinning tissue damage and been validated for the generation of proof-of-concept for cerebellar pathological processes relevant to MS. Additionally, rodent and NHP studies have formed the cornerstone of current knowledge of functional anatomy and cognitive processes. Here, we propose that improved insight into consequences of cerebellar damage in MS at the functional, cellular and molecular levels would be gained by more extensive characterization of EAE cerebellar pathology combined with the power of experimental paradigms in the field of cognition. Such combinatorial approaches would lead to improved potential for the development of MS sensitive markers and evaluation of candidate therapeutics

Conserved features across exon 7/7a/7b of GFAP.

<p>The profile shows detail of the Group 2 profile from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033565#pone-0033565-g002" target="_blank">Figure 2</a> in the region surrounding exons 7 (right of screen) and 7a (right of centre). Exons (wide bars), UTRs (narrow bars) and introns (arrowed lines) are shown for two genes in the UCSC collection and one in RefSeq. At the bottom is the UCSC conservation profile relative to mouse and rat. Conserved regions are labelled A–F (in white). Labelling is from right to left to match the order in which exons are displayed. Conserved motifs that were identified are labelled as follows: GGG, the 3G triplets (feature A); EBF1, motif recognized by the transcription factor EBF1 (feature B); HSF1 and HSF2, the actual and possible acceptor sites identified by Human Splice Finder (scores 93.19 and 76.63 respectively, feature C); PTB1 (feature D) and PTB2 (feature C), conserved PTB-binding motifs embedded in polypyrimidine-rich sequences; PolyA polyadenylation signal AAUAAA (feature E). All other symbols are as per <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033565#pone-0033565-g002" target="_blank">Figure 2</a>.</p

Kyte-Doolittle hydropathy plots for the tail regions of GFAP isoforms across the human, rat and mouse.

<p>The human, rat and mouse sequences are indicated by red, blue and green trendlines respectively. The peaks below zero represent hydrophilicity, whereas those above zero represent hydrophobicity.</p

Comparison of the head, rod and tail domain sequences of GFAP isoforms across species.

<p>For each species, the exon usage for isoforms with 3′end splice variation is shown, relative to the major isoform GFAPα. For each isoform, the total length of the polypeptide is shown in terms of number of aa, followed by the length of the combined head+rod domains in brackets (i.e encoded by exons 1–6, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033565#pone-0033565-g001" target="_blank">Figure 1B</a>). The tail domain consists of exons 7–9 in GFAPα, exons 7 and 7a in GFAPδ/ε and exon 7b (which includes exon 7, intron 7a and exon 7a, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033565#pone-0033565-g001" target="_blank">Figure 1B</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033565#pone.0033565-Blechingberg1" target="_blank">[36]</a>) in GFAPκ. The length of the complete tail domain is shown for each isoform and the length of the variable regions for GFAPδ/ε and GFAPκ in brackets. The above data were generated from the UniProt Knowledgebase database.</p

The four segment classes identified in the GFAP gene using changept.

<p>The top four profiles show, for each sequence position in the human GFAP DNA sequence (chr17: 42982993–42992914 in UCSC genomic coordinates), the probability that the base at that position belongs to conservation groups 1 to 4 respectively, as identified by the program changept applied to a 3-way alignment of rat, mouse and human sequences. At any position, the sum of the four profiles is 1. The two rows below the Group 4 profile display the exons (wide bars), the UTRs (narrow bars) and the introns (thin lines) of GFAP genes recorded in the UCSC and RefSeq collections respectively. Below these are the UCSC conservation tracks relative to mouse and rat, in which darker regions correspond to higher conservation, and parallel lines indicate deletions. At the bottom of the figure are the exon numbers. Note that the gene is transcribed from right to left. Exon boundaries are indicated with red vertical lines. <i>Group 1</i> identifies regions of insertions specific to the human version of the gene; <i>group 2</i> corresponds mainly to the mapped exons of the GFAP gene, appearing to cover regions of high conservation between the three species; <i>group 3</i> is comprised of segments in which deletions occur in either the rat or the mouse genes, but not both; <i>group 4</i> represents the least conserved parts of the gene.</p

Comparison of secondary structures for the GFAP tail regions for the GFAPα, GFAPδ/ε and GFAPκ isoforms across species.

<p>The secondary structures of GFAP isoforms across human, mouse and rat were predicted using the PSIPRED server. Only the tail sequences were used as the sequences are similar up to exon 6. The program predicts the possibility of a helix (pink box), strand (yellow arrow) or a coil for the target amino acid.</p