Project description:TGF-b is an important pleiotropic cytokine with potent immunoregulatory properties. Although many previous reports have been proposed for the immunoregulatory functions of TGF-b on T cells, such as the suppression of cell proliferation, cytokine production and cytokine signaling, as well as the induction of apoptosis, it is not well elucidated whether the each effect of TGF-b on T cells is dependent on Smad signaling or Smad-independent other signaling pathways. The aim of the study was to clarify the involvement of Smad signaling and to investigate the redundancy of Smad2 and Smad3 on various TGF-b-mediated regulation of gene expression in CD4+ T cells. We used microarrays to detail the global program of gene expression regulated by TGF-b in CD4+ T cells, and identified distinct classes of up/down-regulated genes which are dependent on or independent of TGF-b-Smad signaling. Most of genes regulated by TGF-b were redundantly dependent on Smad2 and Smad3, including Foxp3 and IL-2. In addition, some genes were sufficiently regulated via Smad2 or Smad3 signaling alone. In contrast, TGF-b-mediated RORgt induction was independent of Smad signaling. CD4+CD25-CD44loCD62Lhi T cells (naive) were isolated from the spleens in wild-type (WT), T cell-specific Smad2 conditional knockout (Smad2KO or Smad2del/del), Smad3 knockout (Smad3KO or Smad3-/-) or Smad2del/delSmad3+/- mice by using a BD FACS ariaTM cell sorter (BD Bioscience) (purity: >98%). Freshly purified cells were then stimulated with anti-TCR stimuli in the absence or presence of TGF-b for 24 hr, respectively. A complete and precise experimental procedure is given in the "treatment protocol". It was very difficult to obtain the enough number of CD4+CD25-CD44loCD62Lhi naive T cells from Smad2del/delSmad3-/- mice because alomost all of CD4+ T cells were activated in Smad2del/delSmad3-/- mice. We confirmed that the several known Smad-regulated genes were almost out of control in Smad2del/delSmad3+/- CD4+ T cells by using quantitative RT-PCR. Furthermore, previous studies have reported the similar results in other cell types deficit in two alleles of Smad2 and one allele of Smad3. For these reasons, we substituted Smad2del/delSmad3+/- naive T cells for Smad2/3-deficient naive T cells. Cells were quickly collected 24 hr after culture for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Cellular binary fate decisions require the progeny to silence genes associated with the alternative fate. The major subsets of alpha:beta T cells have been extensively studied as a model system for fate decisions. While the transcription factor RUNX3 is required for the initiation of Cd4 silencing in CD8 T cell progenitors, it is not required to maintain the silencing of Cd4 and other helper T lineage genes. The other runt domain containing protein, RUNX1, silences Cd4 in an earlier T cell progenitor, but this silencing is reversed whereas the gene silencing after RUNX3 expression is not reverse. Therefore, we hypothesized that RUNX3 and not RUNX1 recruits other factors that maintains the silencing of helper T lineage genes in CD8 T cells. To this end, we performed a proteomics screen of RUNX1 and RUNX3 to determine candidate silencing factors.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:TGF-beta signaling in neural crest cells is required for normal craniofacial development. This signaling can be transduced via TGF-beta type I receptors (TGFbRI) using Smad-dependent or Smad independent signaling pathways. We used microarrays to identify TGF-beta-responsive genes that are dependent either on TGFbRI kinase, Tak1 kinase or both. Primary palatal mesenchymal cell cultures were established. Cultured cells were stimulated with TGF-beta2 in the presence or absence of TGFbRI kinase and Tak1 kinase inhibitors. Unstimulated cells were used as controls. Total RNAs were isolated and hybridized on Affymetrix microarrays.
Project description:TGF-b is an important pleiotropic cytokine with potent immunoregulatory properties. Although many previous reports have been proposed for the immunoregulatory functions of TGF-b on T cells, such as the suppression of cell proliferation, cytokine production and cytokine signaling, as well as the induction of apoptosis, it is not well elucidated whether the each effect of TGF-b on T cells is dependent on Smad signaling or Smad-independent other signaling pathways. The aim of the study was to clarify the involvement of Smad signaling and to investigate the redundancy of Smad2 and Smad3 on various TGF-b-mediated regulation of gene expression in CD4+ T cells. We used microarrays to detail the global program of gene expression regulated by TGF-b in CD4+ T cells, and identified distinct classes of up/down-regulated genes which are dependent on or independent of TGF-b-Smad signaling. Most of genes regulated by TGF-b were redundantly dependent on Smad2 and Smad3, including Foxp3 and IL-2. In addition, some genes were sufficiently regulated via Smad2 or Smad3 signaling alone. In contrast, TGF-b-mediated RORgt induction was independent of Smad signaling.
Project description:CD69 is a transmembrane protein expressed on the surface of activated leukocyte. The ligand for CD69 and the intracellular signaling pathway of this molecule are yet unknown. It is widely used as a marker of activated lymphocyte, but its function in immune system is not known. We used micro-array to define genes whose expression is regulated by activation antigene CD69. CD4 T cells were isolated from the spleen of wt B6 and CD69-deficient B6 mice and in vitro activated with anti-CD3/anti-CD28 coated beads. On one groupe of wt B6 cells, CD69 was activated using a anti-CD69 and secoundary antibody. RNA extraction and hybridization on Affymetrix microarrays was performed for wt B6, CD69-activated wt B6 and CD69-deficient B6 CD4 T cells.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.