S100B expression defines a state in which GFAP-expressing cells lose their neural stem cell potential and acquire a more mature developmental stage.: S100B is absent in SVZ GFAP expressing cells

International audienceDuring the postnatal development, astrocytic cells in the neocortex progressively lose their neural stem cell (NSC) potential, whereas this peculiar attribute is preserved in the adult subventricular zone (SVZ). To understand this fundamental difference, many reports suggest that adult subventricular GFAP-expressing cells might be maintained in immature developmental stage. Here, we show that S100B, a marker of glial cells, is absent from GFAP-expressing cells of the SVZ and that its onset of expression characterizes a terminal maturation stage of cortical astrocytic cells. Nevertheless, when cultured in vitro, SVZ astrocytic cells developed as S100B expressing cells, as do cortical astrocytic cells, suggesting that SVZ microenvironment represses S100B expression. Using transgenic s100b-EGFP cells, we then demonstrated that S100B expression coincides with the loss of neurosphere forming abilities of GFAP expressing cells. By doing grafting experiments with cells derived from beta-actin-GFP mice, we next found that S100B expression in astrocytic cells is repressed in the SVZ, but not in the striatal parenchyma. Furthermore, we showed that treatment with epidermal growth factor represses S100B expression in GFAP-expressing cells in vitro as well as in vivo. Altogether, our results indicate that the S100B expression defines a late developmental stage after which GFAP-expressing cells lose their NSC potential and suggest that S100B expression is repressed by adult SVZ microenvironment

Association between Regulator of G Protein Signaling 9–2 and Body Weight

Regulator of G protein signaling 9–2 (RGS9–2) is a protein that is highly enriched in the striatum, a brain region that mediates motivation, movement and reward responses. We identified a naturally occurring 5 nucleotide deletion polymorphism in the human RGS9 gene and found that the mean body mass index (BMI) of individuals with the deletion was significantly higher than those without. A splicing reporter minigene assay demonstrated that the deletion had the potential to significantly decrease the levels of correctly spliced RGS9 gene product. We measured the weights of rats after virally transduced overexpression of RGS9–2 or the structurally related RGS proteins, RGS7, or RGS11, in the nucleus accumbens (NAc) and observed a reduction in body weight after overexpression of RGS9–2 but not RGS7 or 11. Conversely, we found that the RGS9 knockout mice were heavier than their wild-type littermates and had significantly higher percentages of abdominal fat. The constituent adipocytes were found to have a mean cross-sectional area that was more than double that of corresponding cells from wild-type mice. However, food intake and locomotion were not significantly different between the two strains. These studies with humans, rats and mice implicate RGS9–2 as a factor in regulating body weight.National Institute of Mental Health (U.S.) (R41MH78570 award)National Center for Research Resources (U.S.) (Rhode Island IDeA Network of Biomedical Research Excellence (RI-INBRE) Award P20RR016457-10

Impact of the TCR Signal on Regulatory T Cell Homeostasis, Function, and Trafficking

Signaling through the T cell antigen receptor (TCR) is important for the homeostasis of naïve and memory CD4+ T cells. The significance of TCR signaling in regulatory T (Treg) cells has not been systematically addressed. Using an Ox40-cre allele that is prominently expressed in Treg cells, and a conditional null allele of the gene encoding p56Lck, we have examined the importance of TCR signaling in Treg cells. Inactivation of p56Lck resulted in abnormal Treg homeostasis characterized by impaired turnover, preferential redistribution to the lymph nodes, loss of suppressive function, and striking changes in gene expression. Abnormal Treg cell homeostasis and function did not reflect the involvement of p56Lck in CD4 function because these effects were not observed when CD4 expression was inactivated by Ox40-cre.The results make clear multiple aspects of Treg cell homeostasis and phenotype that are dependent on a sustained capacity to signal through the TCR

The expression of mouse CLEC-2 on leucocyte subsets varies according to their anatomical location and inflammatory state

Expression of mouse C‐type lectin‐like receptor 2 (CLEC‐2) has been reported on circulating CD11b(high) Gr‐1(high) myeloid cells and dendritic cells (DCs) under basal conditions, as well as on a variety of leucocyte subsets following inflammatory stimuli or in vitro cell culture. However, previous studies assessing CLEC‐2 expression failed to use CLEC‐2‐deficient mice as negative controls and instead relied heavily on single antibody clones. Here, we generated CLEC‐2‐deficient adult mice using two independent approaches and employed two anti‐mouse CLEC‐2 antibody clones to investigate surface expression on hematopoietic cells from peripheral blood and secondary lymphoid organs. We rule out constitutive CLEC‐2 expression on resting DCs and show that CLEC‐2 is upregulated in response to LPS‐induced systemic inflammation in a small subset of activated DCs isolated from the mesenteric lymph nodes but not the spleen. Moreover, we demonstrate for the first time that peripheral blood B lymphocytes present exogenously derived CLEC‐2 and suggest that both circulating B lymphocytes and CD11b(high) Gr‐1(high) myeloid cells lose CLEC‐2 following entry into secondary lymphoid organs. These results have significant implications for our understanding of CLEC‐2 physiological function

Pengembangan Perangkat Peer Assessment untuk Menilai Keterampilan Representasi, Karakter Disiplin dan Kerjasama Siswa Kelas V SD di Yayasan Yohanes Gabriel Surabaya

Penelitian ini bertujuan untuk (1) menghasilkan perangkat peer assessment yang layak untuk menilai keterampilan representasi, karakter disiplin dan kerjasama siswa kelas V SD, dan (2) mengetahui reliabilitas perangkat peer assessment untuk menilai keterampilan representasi, karakter disiplin, dan kerjasama siswa kelas V SD yang dikembangkan. Penelitian ini merupakan penelitian dan pengembangan (R&D). Penelitian ini menggunakan model ADDIE. Subjek uji coba adalah siswa kelas V SD di Yayasan Yohanes Gabriel Surabaya. Subjek coba kelompok kecil terdiri dari 63 siswa. Subjek uji coba lapangan terdiri atas 144 siswa. Pengumpulan data menggunakan validasi ahli evaluasi, validasi ahli karakter, validasi ahli matematika, angket respon guru, dan angket respon siswa. Analisis data menggunakan uji faktorial dan uji interrater reliability Kappa Cohen. Hasil penelitian berupa perangkat peer assessment yang layak dan efektif untuk menilai keterampilan representasi, karakter disiplin dan kerjasama siswa. Kelayakan bahan ajar ini dapat dilihat dari hasil penilaian ahli evaluasi pada aspek isi pernyataan peer assessment sebesar 45 pada skala sangat baik, aspek tujuan penilaian sebesar 10 pada skala sangat baik dan aspek bahasa mendapat nilai 16 pasa skala sangat baik. Ahli karakter memberikan penilaian untuk aspek langkah-langkah pembelajaran sebesar 8 pada skala sangat baik, aspek isi peer assessment sebesar 32 pada skala sangat baik, aspek tujuan penilaian sebesar 11 pada skala sangat baik, dan aspek bahasa sebesar 16 pada skala sangat baik. Ahli matematika memberi nilai pada aspek langkah-langkah pembelajara dalam RPP sebesar 43 pada skala sangat baik dan untuk aspek bahasa sebesar 9 pada skala baik. Menurut respon guru dan siswa, penilaian teman sebaya yang dikembangkan masuk kategori sangat baik, sedangkan reliabilitas perangkat penilaian dilihat pada uji validitas yang menunjukkan p > 0.5 dan uji interrater reliability yang menunjukkan hasil bahwa penilaian teman sebaya yang dilakukan siswa dapat digunakan sebagai acuan untuk menilai dengan level Kappa Cohen dengan level agreement minimal moderate. Sebagai saran masukan sebaiknya peer assessment dibuat dalam bentuk program komputer sehingga bisa dengan mudah dan sering digunakan saat di kelas. Kata Kunci : peer assessment, keterampilan representasi, karakter disiplin, kerjasama

Genes associated with multiple sclerosis: 15 and counting

Evaluation of: The International Multiple Sclerosis Genetics Consortium (IMSGC). IL12A, MPHOSPH9/CDK2AP1 and RGS1 are novel multiple sclerosis susceptibility loci. Genes Immun. 11(5), 397-405 (2010). Multiple sclerosis (MS) develops in genetically susceptible populations as a result of environmental exposures, and discovering these genetic and/or environmental factors will provide fundamental new insights into the pathogenesis, diagnosis and treatment of this disabling disease. With the introduction of genome-wide association studies, the number of genes found to be associated with MS has increased rapidly. In all of these genes, in a study by the International Multiple Sclerosis Genetics Consortium, the classic MS risk locus, HLA-DRB1, stood out with remarkably strong statistical significance, but they also identified 12 other loci and/or genes associated with MS. However, all of these alleles have a very modest odds ratio and they explain approximately 3% of the variance in MS risk. Recently, the International Multiple Sclerosis Genetics Consortium provided evidence for three new loci that show significant association at a genome-wide level: RGS1, IL12A and MPHOSPH9/CDK2AP1. In this article, we will review the three newly discovered susceptibility loci and the implications of genome-wide association studies in MS on clinical practice