Novel mutations in TARDBP (TDP-43) in patients with familial amyotrophic lateral sclerosis.

The TAR DNA-binding protein 43 (TDP-43) has been identified as the major disease protein in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration with ubiquitin inclusions (FTLD-U), defining a novel class of neurodegenerative conditions: the TDP-43 proteinopathies. The first pathogenic mutations in the gene encoding TDP-43 (TARDBP) were recently reported in familial and sporadic ALS patients, supporting a direct role for TDP-43 in neurodegeneration. In this study, we report the identification and functional analyses of two novel and one known mutation in TARDBP that we identified as a result of extensive mutation analyses in a cohort of 296 patients with variable neurodegenerative diseases associated with TDP-43 histopathology. Three different heterozygous missense mutations in exon 6 of TARDBP (p.M337V, p.N345K, and p.I383V) were identified in the analysis of 92 familial ALS patients (3.3%), while no mutations were detected in 24 patients with sporadic ALS or 180 patients with other TDP-43-positive neurodegenerative diseases. The presence of p.M337V, p.N345K, and p.I383V was excluded in 825 controls and 652 additional sporadic ALS patients. All three mutations affect highly conserved amino acid residues in the C-terminal part of TDP-43 known to be involved in protein-protein interactions. Biochemical analysis of TDP-43 in ALS patient cell lines revealed a substantial increase in caspase cleaved fragments, including the approximately 25 kDa fragment, compared to control cell lines. Our findings support TARDBP mutations as a cause of ALS. Based on the specific C-terminal location of the mutations and the accumulation of a smaller C-terminal fragment, we speculate that TARDBP mutations may cause a toxic gain of function through novel protein interactions or intracellular accumulation of TDP-43 fragments leading to apoptosis

Global prevalence and disease burden of vitamin D deficiency: a roadmap for action in low- and middle-income countries.

Vitamin D is an essential nutrient for bone health and may influence the risks of respiratory illness, adverse pregnancy outcomes, and chronic diseases of adulthood. Because many countries have a relatively low supply of foods rich in vitamin D and inadequate exposure to natural ultraviolet B (UVB) radiation from sunlight, an important proportion of the global population is at risk of vitamin D deficiency. There is general agreement that the minimum serum/plasma 25-hydroxyvitamin D concentration (25(OH)D) that protects against vitamin D deficiency-related bone disease is approximately 30 nmol/L; therefore, this threshold is suitable to define vitamin D deficiency in population surveys. However, efforts to assess the vitamin D status of populations in low- and middle-income countries have been hampered by limited availability of population-representative 25(OH)D data, particularly among population subgroups most vulnerable to the skeletal and potential extraskeletal consequences of low vitamin D status, namely exclusively breastfed infants, children, adolescents, pregnant and lactating women, and the elderly. In the absence of 25(OH)D data, identification of communities that would benefit from public health interventions to improve vitamin D status may require proxy indicators of the population risk of vitamin D deficiency, such as the prevalence of rickets or metrics of usual UVB exposure. If a high prevalence of vitamin D deficiency is identified (>20% prevalence of 25(OH)D 1%), food fortification and/or targeted vitamin D supplementation policies can be implemented to reduce the burden of vitamin D deficiency-related conditions in vulnerable populations

Rationale and Plan for Vitamin D Food Fortification : A Review and Guidance Paper

Vitamin D deficiency can lead to musculoskeletal diseases such as rickets and osteomalacia, but vitamin D supplementation may also prevent extraskeletal diseases such as respiratory tract infections, asthma exacerbations, pregnancy complications and premature deaths. Vitamin D has a unique metabolism as it is mainly obtained through synthesis in the skin under the influence of sunlight (i.e., ultraviolet-B radiation) whereas intake by nutrition traditionally plays a relatively minor role. Dietary guidelines for vitamin D are based on a consensus that serum 25-hydroxyvitamin D (25[OH]D) concentrations are used to assess vitamin D status, with the recommended target concentrations ranging from >= 25 to >= 50 nmol/L (>= 10->= 20 ng/mL), corresponding to a daily vitamin D intake of 10 to 20 mu g (400-800 international units). Most populations fail to meet these recommended dietary vitamin D requirements. In Europe, 25(OH)D concentrations <30 nmol/L (12 ng/mL) and <50 nmol/L (20 ng/mL) are present in 13.0 and 40.4% of the general population, respectively. This substantial gap between officially recommended dietary reference intakes for vitamin D and the high prevalence of vitamin D deficiency in the general population requires action from health authorities. Promotion of a healthier lifestyle with more outdoor activities and optimal nutrition are definitely warranted but will not erase vitamin D deficiency and must, in the case of sunlight exposure, be well balanced with regard to potential adverse effects such as skin cancer. Intake of vitamin D supplements is limited by relatively poor adherence (in particular in individuals with low-socioeconomic status) and potential for overdosing. Systematic vitamin D food fortification is, however, an effective approach to improve vitamin D status in the general population, and this has already been introduced by countries such as the US, Canada, India, and Finland. Recent advances in our knowledge on the safety of vitamin D treatment, the dose-response relationship of vitamin D intake and 25(OH)D levels, as well as data on the effectiveness of vitamin D fortification in countries such as Finland provide a solid basis to introduce and modify vitamin D food fortification in order to improve public health with this likewise cost-effective approach.Peer reviewe

Transgenic Expression of Soluble Human CD5 Enhances Experimentally-Induced Autoimmune and Anti-Tumoral Immune Responses

CD5 is a lymphoid-specific transmembrane glycoprotein constitutively expressed on thymocytes and mature T and B1a lymphocytes. Current data support the view that CD5 is a negative regulator of antigen-specific receptor-mediated signaling in these cells, and that this would likely be achieved through interaction with CD5 ligand/s (CD5L) of still undefined nature expressed on immune or accessory cells. To determine the functional consequence of loss of CD5/CD5L interaction in vivo, a new transgenic mouse line was generated (shCD5EμTg), expressing a circulating soluble form of human CD5 (shCD5) as a decoy to impair membrane-bound CD5 function. These shCD5EμTg mice showed an enhanced response to autologous antigens, as deduced from the presentation of more severe forms of experimentally inducible autoimmune disease (collagen-induced arthritis, CIA; and experimental autoimmune encephalitis, EAE), as well as an increased anti-tumoral response in non-orthotopic cancer models (B16 melanoma). This enhancement of the immune response was in agreement with the finding of significantly reduced proportions of spleen and lymph node Treg cells (CD4+CD25+FoxP3+), and of peritoneal IL-10-producing and CD5+ B cells, as well as an increased proportion of spleen NKT cells in shCD5EμTg mice. Similar changes in lymphocyte subpopulations were observed in wild-type mice following repeated administration of exogenous recombinant shCD5 protein. These data reveal the relevant role played by CD5/CD5L interactions on the homeostasis of some functionally relevant lymphocyte subpopulations and the modulation of immune responses to autologous antigens

Vitamin D Binding Protein Genotype Is Associated with Serum 25-Hydroxyvitamin D and PTH Concentrations, as Well as Bone Health in Children and Adolescents in Finland

Peer reviewe

CD5-CK2 Signaling Modulates Erk Activation and Thymocyte Survival

<div><p>CD5 is well recognized for its importance in thymic selection. Although this property of CD5 has been attributed to its ITIM-domain dependent regulation of TCR-signal strength, the mechanism has not been established. A second major signaling domain within the cytoplasmic tail of CD5 is a CK2 binding/activation domain (CD5-CK2BD). Using a gene-targeted mouse in which the CD5-CK2BD is selectively ablated (CD5-ΔCK2BD), we determined that loss of function of CD5-CK2 signaling in a MHC-II selecting TCR transgenic (OT-II) mouse resulted in decrease in double positive (DP) thymocytes, which correlated with enhanced apoptosis. Remarkably, DP cells expressing high levels of CD5 and CD69 and single positive (CD4+SP) thymocytes were increased in CD5-ΔCK2BD mice indicating that CD5-CK2 signaling regulates positive selection and promotes survival. Consistent with this possibility, we determined that the activation and nuclear localization of ERK as well as apoptosis was greater in thymic populations from OTII CD5-ΔCK2BD mice than OTII CD5-WT mice following injection of OVA_323-339-peptide. The mobilization of Ca²⁺, an early event of TCR activation, was not altered by the loss of CD5-CK2 signaling. Collectively, these data demonstrate that the CD5-CK2 signaling axis regulates positive selection by modulating activation of ERK and promoting survival independent of proximal TCR signals.</p></div

Nuclear translocation pERK is independent of CD5-CK2 signaling.

<p>(A) Images of DP and CD4+SP thymocytes obtained from PBS or OVAp injected CD5-WT OTII and CD5-ΔCK2BD OTII TCR-Tg mice and analyzed by imaging flow cytometry. The images show each channel individually represented as well as an overlay of all channels. The data are representative of at least 900 images each from 2 independent experiments (n = 2 mice each group). (B) Quantitative representation of all events represented in (A). The graphs reflect mean±SEM pERK levels inside the nucleus (left panels) or ratio of pERK in nucleus to whole cell (right panels) within DP (upper panels) or CD4+SP (lower). (C) Images of pERK in DP and CD4+SP thymocytes obtained from non-TCR transgenic CD5-WT and CD5-ΔCK2BD mice. The images are representative of 900–1500 images from 3 independent experiments (n = 3 mice each group). (D) Quantitative representation analyzed similar to (B). **p<0.01 ****p<0.0001, unpaired two-tailed Student-t test.</p

Increased TCR dependent MAPK activation and enhanced AICD in CD5-CK2BD deficient mice is independent of peripheral T cells activation and thymocyte FasL expression.

<p>(A) Total cell numbers (left panel) of CD5-WT vs CD5-ΔCK2BD newborn mice after injection of either PBS (control) or α-CD3 (20 μg) for 24h. To evaluate the effect of anti-CD3 stimulation, both CD5-ΔCK2BD or CD5-WT were compared with their respective unstimulated controls. <b>S</b>ubpopulation analysis show DP (middle panel) or CD4+ SP thymocytes (right panel) (B) Scatter plots showing Bcl-2 levels in DP and CD4+ SP thymocytes. (C) Bar graphs of FasL expression in PBS injected and anti-CD3 injected mice. Adult thymocytes were used as positive control. (D) Scatter plots show pERK expression 24h after α-CD3 injection or PBS as in DP and CD4+ SP cells from CD5-WT and CD5-ΔCK2BD newborn mice. (E) Graphs showing expression of pJNK (F) pP38 and (G) pZap70. Each graph is representative of 1 independent experiment (n = 5–6 each group). *p<0.05, **p<0.01, ***p<0.001, unpaired two-tailed Student-t test.</p

Ablation of CD5-CK2 binding domain alters thymic T cell development.

<p>Thymic DN, DP (CD4+CD8+) and SP (CD4+ or CD8+) populations (dot plots), proportions and absolute numbers (graphs) in CD5-WT OTII and CD5-ΔCK2BD OTII TCR-Tg mice (A) and CD5-WT and CD5-ΔCK2BD mice (B). Ratio of CD4:CD8 SP cells in CD5-WT OTII and CD5-ΔCK2BD OTII TCR-Tg mice (C) and CD5-WT and CD5-ΔCK2BD non-TCR Tg mice (D). The flow cytometric dot plots are representative of one of five mice from each strain. The graphs represent data from 4 independent experiments (n = 4–7 each group) *p<0.05, **p<0.01, ***p<0.001, unpaired two-tailed Student-t test.</p

Enhanced <i>in vitro</i> and <i>in vivo</i> thymocyte apoptosis in the absence of the CD5-CK2BD.

<p>(A) Apoptosis (Annexin V⁺ 7-AAD^-/+) in thymocytes from CD5-WT and CD5-ΔCK2BD mice following culture for 24h in the presence of α-CD3 and/or α-CD5 or medium alone. The graphs show apoptosis in gated DP, CD4+SP and CD8+SP and populations. Data represent mean±SEM from one experiment (n = 3–4 independent mice). (B) Histograms (lower left) show proportion of cells with elevated caspase 3 levels relative to unstained cells within DP and CD4+SP thymocytes obtained from CD5-WT and CD5-ΔCK2BD OTII TCR-Tg mice after i.p injection with either PBS or OVAp. Solid vertical lines are drawn to reflect unstained MFI and to identify the caspase 3 on the highest expressing population. Scatter plots show MFI of caspase 3 levels in DP cells (top), proportion of DP cells expressing high levels of caspase 3 (middle) and MFI of high caspase 3 expressing CD4+ SP cells (bottom). Data represents 4 independent experiments (n = 4 mice each group). Numbers are presented as mean±SEM, *p<0.05, unpaired two-tailed Student-t test.</p