In welke mate voldoen fysiotherapeuten aan de Nederlandse Beweegrichtlijn en de 10.000 stappennorm?

Voldoende fysieke activiteit verkleint het risico op chronische ziekten en heeft een positief effect op het psychische welzijn. De mens hoeft in de moderne tijd niet erg fysiek actief te zijn voor zijn dagelijkse bezigheden. Vanwege de vermindering van de fysieke activiteitenniveau en de mogelijke gezondheidsrisico’s daarvan zijn er verschillende normen en richtlijnen opgesteld voor de mate van gezond bewegen

Polymorphic differences within HLA-C alleles contribute to alternatively spliced transcripts lacking exon 5

The human leukocyte antigen (HLA) genes are amongst the most polymorphic in the human genome. Alternative splicing could add an extra layer of complexity, but has not been studied extensively. Here, we applied an RNA based approach to study the influence of allele polymorphism on alternative splicing of HLA-C in peripheral blood. RNA was isolated from these peripheral cells, converted into cDNA and amplified specifically for twelve common HLA-C allele groups. Through subsequent sequencing of HLA-C, we observed alternative splicing variants of HLA-C*04 and *16 that resulted in exon 5 skipping and were co-expressed with the mature transcript. Investigation of intron 4 sequences of HLA-C*04 and *16 compared to other HLA-C alleles demonstrated no effect on predicted splice sites and branch point. To further investigate if the unique polymorphic positions in exon 5 of HLA-C*04 or *16 may facilitate alternative splicing by acting on splicing regulatory elements (SRE), in-silico splicing analysis was performed. While the HLA-C*04 specific SNP in exon 5 had no effect on predicted exonic SRE, the HLA-C*16 specific exon 5 SNP did alter exonic SRE. Our findings provide experimental and theoretical support for the concept that polymorphisms within the HLA-C alleles influence the alternative splicing of HLA-C. This article is protected by copyright. All rights reserved

Mitochondrial dynamics in visual cortex are limited in vivo and not affected by axonal structural plasticity.

Mitochondria buffer intracellular Ca2+ and provide energy [1]. Because synaptic structures with high Ca2+ buffering [2–4] or energy demand [5] are often localized far away from the soma, mitochondria are actively transported to these sites [6–11]. Also, the removal and degradation of mitochondria are tightly regulated [9, 12, 13], because dysfunctional mitochondria are a source of reactive oxygen species, which can damage the cell [14]. Deficits in mitochondrial trafficking have been proposed to contribute to the pathogenesis of Parkinson’s disease, schizophrenia, amyotrophic lateral sclerosis, optic atrophy, and Alzheimer’s disease [13, 15–19]. In neuronal cultures, about a third of mitochondria are motile, whereas the majority remains stationary for several days [8, 20]. Activity-dependent mechanisms cause mitochondria to stop at synaptic sites [7, 8, 20, 21], which affects synapse function and maintenance. Reducing mitochondrial content in dendrites decreases spine density [22, 23], whereas increasing mitochondrial content or activity increases it [7]. These bidirectional interactions between synaptic activity and mitochondrial trafficking suggest that mitochondria may regulate synaptic plasticity. Here we investigated the dynamics of mitochondria in relation to axonal boutons of neocortical pyramidal neurons for the first time in vivo. We find that under these circumstances practically all mitochondria are stationary, both during development and in adulthood. In adult visual cortex, mitochondria are preferentially localized at putative boutons, where they remain for several days. Retinal-lesion-induced cortical plasticity increases turnover of putative boutons but leaves mitochondrial turnover unaffected. We conclude that in visual cortex in vivo, mitochondria are less dynamic than in vitro, and that structural plasticity does not affect mitochondrial dynamics

Summary of all SMM and FRAP analyses of YFP-GR, YFP-MR and YFP-GR deletion mutants.

<p>Short, ‘short’ bound fraction; long, ‘long’ bound fraction; D, diffusion coefficient; imm. time, average immobilization time; Δ-Flu, Δ-Fludrocortisone; dex, dexamethasone; Predn, prednisolone; csol, cortisol; cort, corticosterone; aldo, aldosterone; DOC, deoxycorticosterone; spiro, spironolactone; epler, eplerenone. Fraction size and diffusion coefficient for immobile fraction in SMM are for both immobile fractions combined. Results are represented as best fit ± SEM (of three separate fits) for SMM and as average ± SEM of top 10% fits for FRAP.</p

Ligand structure determines the nuclear mobility of the GR.

<p>A range of natural and synthetic agonists (black bars) and an antagonists (red bar) were tested for their effect on the intranuclear mobility of the GR by both SMM (A) and FRAP (B–C) analysis. Multiple structural elements of the steroids are associated with a reduced mobility of the receptor. Altered mobility can be reflected in all aspects of mobility: a larger bound fraction (SMM; white bars and FRAP; white and light grey bars combined) a lower diffusion coefficient (in µm²/s, written in its corresponding bar in A) and longer immobilization times (C). (D and E) A mutation of phenylalanine 623 to alanine (F623A) prevents interactions of the 9-fluoro group of steroids within the ligand binding pocket of the GR. F623A YFP-GR still translocates completely to the nucleus after 3 hours of 1 µM prednisolone or Δ-fludrocortisone treatment (D). SMM analyses of nuclear F623A YFP-GR kinetics shows that the mobility of F623A YFP-GR is highly similar after either Δ-fludrocortisone or prednisolone treatment (black bars for the diffusing fraction, with their corresponding diffusion coefficient (in µm²/s) written within their corresponding bar; (E)). SMM: n = 20, FRAP: n = 30. Data represented as total fit ± SEM (of 3 separate PICS analyses) for SMM and as average of top 10% fits ± SEM for FRAP. Δ-flu; Δ-fludrocortisone, dex; dexamethasone, Predn; prednisolone, csol; cortisol, cort; corticosterone. The data for GR-dexamethasone is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090532#pone-0090532-g002" target="_blank">Figure 2</a>.</p

Loss of either the DNA-binding or the ligand-binding domain results in a high GR mobility.

<p>(A) Schematic representation of three functional YFP-GR deletion mutants tested. (B and C) Fraction distributions as analyzed by SMM (B) and FRAP (C). Diffusion coefficients are written within the corresponding bars in B (in µm²/s). (D) Immobilization times of both bound fractions in FRAP. While loss of the AF-1 domain hardly affects GR's nuclear mobility, deletion of the DBD and especially the LBD leads to a very mobile receptor with reduced frequency and average duration of DNA-binding and a higher diffusion coefficient. SMM: n = 20, FRAP: n = 30. Data represented as total fit ± SEM (of 3 separate PICS analyses) for B and as average of top 10% fits ± SEM for C and D. The data for wild type GR is the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090532#pone-0090532-g003" target="_blank">Figure 3</a>.</p

SMM and FRAP analyses provide a consistent model of the intranuclear mobility of the GR.

<p>(A) A two-population fit of SMM analysis for dexamethasone-bound YFP-GR identifies two fractions of approximately equal size. (B) Both fractions show a linear increase in mean squared displacement (MSD) over time, but with a 40-fold difference in MSD. Diffusion coefficients (D_fast and D_slow) are calculated from a linear fit of the experimental data (dashed lines; D =  slope/4). The D_fast of 1.31 µm²/s fits to diffusing molecules, while the D_slow of only 0.03 µm²/s best fits to the slow movement of chromatin and the molecules bound to it. (C) A 3-population Monte Carlo simulation of the FRAP curve for dexamethasone-bound YFP-GR shows that half of the nuclear population is diffusing, while the remainder is subdivided into two bound fractions that differ in their immobilization times. The fraction size of the diffusing fraction is similar in size as that obtained from SMM analysis. (D) Both bound fractions are only transiently immobilized, with a 3-fold difference in duration. (A and B) Data represented as best fit ± SEM (of 3 separate PICS analyses). (C and D) Data represented as average of top 10% best fits ± SEM.</p