The purpose of this study was to characterize the histologic development of OA in a mouse model where OA is induced by destabilization of the medial meniscus (DMM model) and to identify genes regulated during different stages of the disease, using RNA isolated from the joint organ and analyzed using microarrays.427 genes from the microarrays passed consistency and significance filters. There was an initial up-regulation at 2 and 4 weeks of genes involved in morphogenesis, differentiation, and development, including growth factor and matrix genes, as well as transcription factors including Atf2, Creb3l1, and Erg. Most genes were off or down-regulated at 8 weeks with the most highly down-regulated genes involved in cell division and the cytoskeleton. Gene expression increased at 16 weeks, in particular extracellular matrix genes including Prelp, Col3a1 and fibromodulin.The results support a phasic development of OA with early matrix remodelling and transcriptional activity followed by a more quiescent period that is not maintained.
Disease progression and phasic changes in gene expression in a mouse model of osteoarthritis.
Sex, Age, Specimen part
View SamplesRegulatory T cells (Tregs) can suppress a wide variety of cell types, in diverse organ sites and inflammatory conditions. While Tregs possess multiple suppressive mechanisms, the number required for maximal function is unclear. Furthermore, whether any inter-relationship orcross-regulatory mechanisms exist that areused to orchestrate and control their utilization is unknown. Here we assessed the functional capacity of Tregs lacking the ability to secrete both interleukin-10 (IL-10) and IL-35, which individually are required for maximal Treg activity. Surprisingly, IL-10/IL-35-double deficient Tregswere fully functionalin vitro and in vivo. Loss of IL-10 and IL-35 was compensated for by a concurrent increase in cathepsin E (CTSE) expression, enhanced TRAIL (Tnfsf10)expression and soluble TRAIL release, rendering IL-10/IL-35-double deficient Tregsfunctionally dependent on TRAIL in vitro and in vivo. Lastly, while C57BL/6 Tregs are IL-10/IL-35-dependent, Balb/c Tregs, which express high levels of CTSE and enhanced TRAIL expression, are TRAIL-dependent.These data reveal that cross-regulatory pathways exist, which control the utilization of suppressive mechanisms,thereby providing Tregfunctional plasticity.
The plasticity of regulatory T cell function.
Specimen part
View SamplesPseudoautosomal regions (PAR1 and PAR2) in eutherians retain homologous regions between the X and Y chromosomes that play a critical role in the obligatory X-Y crossover during male meiosis. Genes that reside in the PAR1 are exceptional in that they are rich in repetitive sequences and undergo a very high rate of recombination. Remarkably, murine PAR1 homologs have translocated to various autosomes, reflecting the complex recombination history during the evolution of the mammalian X chromosome. We now report that the SNF2-type chromatin remodeling protein ATRX controls the expression of eutherians ancestral PAR1 genes that have translocated to autosomes in the mouse. In addition, we have identified two potentially novel mouse PAR1 orthologs. We propose that the ancestral PAR1 genes share a common epigenetic environment that allows ATRX to control their expression.
The SWI/SNF protein ATRX co-regulates pseudoautosomal genes that have translocated to autosomes in the mouse genome.
Sex
View SamplesBeyond demonstrating a critical role for progesterone receptor signaling in normal mammary epithelial proliferation, the progesterone receptor knockout mouse disclosed the progesterone receptor along with its effector pathways as key determinants of mammary neoplastic progression. Despite these advances, however, further progress in our mechanistic understanding of progesterones involvement in mammary morphogenesis and tumorigenesis is contingent upon defining the essential effector pathways responsible for transducing the progesterone signal into a mammary proliferative and/or pro-survival response. Toward this goal, a judiciously chosen acute progesterone treatment regimen together with microarray methods was applied to the mammary gland of the normal mouse to uncover new effectors that operate immediately downstream of the progesterone mammary signal. Examination of the resultant progesterone-responsive transcriptome disclosed inhibitor of differentiation or DNA binding 4 (Id4) as a molecular target acutely induced by progesterone in the murine mammary epithelium.
Transcriptional response of the murine mammary gland to acute progesterone exposure.
No sample metadata fields
View SamplesLevels of C/EBP are low in myeloid blast crisis (BC) of chronic myelogenous leukemia (CML) and its expression in p210BCR/ABL-expressing hematopoietic cells induces granulocytic differentiation, inhibits proliferation and suppresses leukemogenesis. To assess the mechanisms involved in these effects, C/EBP targets were identified by microarray analyses. Upon C/EBP activation, expression of c-Myb and GATA-2 was repressed in 32D-BCR/ABL, K562 and CML-BC primary cells but only c-Myb levels decreased slightly in CD34+ normal progenitors. The role of these two genes for the biological effects of C/EBP was assessed by perturbing their expression in K562 cells. Expression of c-Myb blocked the proliferation inhibition and differentiation-inducing effects of C/EBP while c-Myb siRNA treatment enhanced C/EBP-mediated proliferation inhibition and induced changes in gene expression indicative of monocytic differentiation. GATA-2 expression suppressed the proliferation inhibitory effect of C/EBP but blocked in part the effect on differentiation; GATA-2 siRNA treatment had no effects on C/EBP induction of differentiation but inhibited proliferation of K562 cells, alone or upon C/EBP activation. In summary, the effects of C/EBP in p210BCR/ABL -expressing cells depend, in part, on transcriptional repression of c-Myb and GATA-2. Since perturbation of c-Myb and GATA-2 expression has non identical consequences for proliferation and differentiation of K562 cells, the effects of C/EBP appear to involve different transcription-regulated targets.
Transcriptional repression of c-Myb and GATA-2 is involved in the biologic effects of C/EBPalpha in p210BCR/ABL-expressing cells.
No sample metadata fields
View SamplesMouse infection with the tapeworm Hymenolepis diminuta leads to a less severe DNBS-colitis. Increased Th2 and regulatory cytokine production in the spleen is a hallmark of Hymenolepis diminuta infection, therefore we hypothesized that given this microenvironment, splenic adaptive cells acquire an anti-inflammatory phenotype. We tested the ability of putative splenic regulatory B cells generated by Hymenolepis diminuta infection to down-regulate intestinal inflammation. We found that unlike splenic B cells from uninfected mice, splenic B cells from Hymenolepis diminuta -infected animals ameliorated chemically-induced colitis.
Splenic B cells from Hymenolepis diminuta-infected mice ameliorate colitis independent of T cells and via cooperation with macrophages.
Specimen part
View SamplesAim of present study was to describe the changes induced deletion of the Wfs1 gene in the temporal lobe of mice. Mutant mice were backcrossed to two different genomic backgrounds in order to exclude confounding foreign genomic background influence. Samples from temporal lobes were analyzed by using Affymetrix Genechips, expression profiles were functionally annotated by using GSEA and Ingenuity Pathway Analysis. We found that Wfs1 mutant mice are significantly smaller (20.9 1.6 g) than their wild-type counterparts (31.0 0.6g, p < 0.0001). Interestingly, genechip analysis identified growth hormone transcripts up-regulated and functional analysis found appropriate pathways activated. Moreover, we found significant increase in the level of IGF1 in the plasma of wfs1 mutant mice. Taken together, wfs1 mutation induces growth retardation whereas the growth hormone pathway is activated. Further studies are needed to describe biochemical and molecular details of the growth hormone axis in the wfs1 mutant mice.
Wfs1 gene deletion causes growth retardation in mice and interferes with the growth hormone pathway.
Specimen part
View SamplesAnalysis of HSCs from control and c-myc N-myc deficient long-term hematopoietic stem cells. HSCs lacking both c-myc and N-myc display increased apoptosis rates. Data provide insight into the molecular changes occuring upon complete loss of Myc activity, clarifying the resulting apoptotic mechanism and the role of Myc family proteins in HSCs and commited progenitors.
Hematopoietic stem cell function and survival depend on c-Myc and N-Myc activity.
Age, Specimen part
View SamplesAnalysis of HSCs from control and c-myc N-myc deficient long-term hematopoietic stem cells. HSCs lacking both c-myc and N-myc display increased apoptosis rates. Data provide insight into the molecular changes occuring upon complete loss of Myc activity, clarifying the resulting apoptotic mechanism and the role of Myc family proteins in HSCs.
Hematopoietic stem cell function and survival depend on c-Myc and N-Myc activity.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Hematopoietic stem cell function and survival depend on c-Myc and N-Myc activity.
Age, Specimen part
View Samples