Steroid and xenobiotic receptor (SXR) and its murine ortholog pregnane X receptor (PXR) are nuclear receptors that are expressed mainly in the liver and the intestine. They function as xenobiotic sensors by inducing genes involved in detoxification and drug excretion. Recent evidence showed that SXR and PXR are also expressed in bone tissue where they mediate bone metabolism. Here we report that systemic deletion of PXR results in aging-dependent wearing of articular cartilage of knee joints. Histomorphometrical analysis showed remarkable reduction of width and an enlarged gap between femoral and tibial articular cartilage in PXR knockout mice. We hypothesized that genes induced by SXR in chondrocytes have a protective effect on articular cartilage and identified Fam20a (family with sequence similarity 20a) as an SXR-dependent gene induced by the known SXR ligands, rifampicin and vitamin K2. Lastly, we demonstrated the biological significance of Fam20a expression in chondrocytes by evaluating osteoarthritis-related gene expression of primary articular chondrocytes. Consistent with epidemiological findings, our findings indicate that SXR/PXR protects against aging-dependent wearing of articular cartilage and that ligands for SXR/PXR have potential role in preventing osteoarthritis caused by aging.
Pregnane X receptor knockout mice display aging-dependent wearing of articular cartilage.
Cell line
View SamplesD-3-Phosphoglycerate dehydrogenase (Phgdh; EC 1.1.1.95) is a necessary enzyme for de novo L-serine biosynthesis via the phosphorylated pathway. We demonstrated previously that Phgdh is expressed exclusively by neuroepithelium and radial glia in developing mouse brain and later mainly by astrocytes. Mutations in the human PHGDH gene cause serine deficiency disorders (SDD) associated with severe neurological symptoms such as congenital microcephaly, psychomotor retardation, and intractable seizures. We recently demonstrated that genetically engineered mice, in which the gene for Phgdh has been disrupted, have significantly decreased levels of serine and glycine, and exhibit malformation of brain such as microcephaly. The Phgdh null (KO) embryos exhibit lethal phenotype after gestational day 14, indicating that the phosphorylated pathway is essential for embryogenesis, especially for brain development. It is worth noting that the Phgdh knockout (KO) embryos primarily displayed microcephaly, which is the most conspicuous phenotype of patients with SDD. Thus, Phgdh KO mice are a useful animal model for studying the effect of diminished L-serine levels on development of the central nervous system and other organs. To better understand the mechanism underlying the molecular pathogenesis of SDD, we sought to examine whether gene expression is altered in the Phgdh KO mouse model. We identify genes that have altered expression in the head of the Phgdh KO embryos using the GeneChip array. Some of the genes identified by this method belong in functional categories that are relevant to the biochemical and morphological aberrations of the Phgdh deletion.
Inactivation of the 3-phosphoglycerate dehydrogenase gene in mice: changes in gene expression and associated regulatory networks resulting from serine deficiency.
Specimen part
View SamplesThe sclera maintains and protects the eye ball, which receives visual inputs. The aim of this study is to identify characteristics of the human sclera as one of the connective tissues derived from the neural crest and mesoderm. We have here demonstrated microarray data of cultured human scleral cells.
Human sclera maintains common characteristics with cartilage throughout evolution.
No sample metadata fields
View SamplesInteraction of ICOS - ICOS ligand is required for the germinal center formation, T-cell immune responses, and development of autoimmune diseases. Human ICOS deficiency with the identical ICOS mutation has been identified in nine patients worldwide. In vitro studies showed T-cell defect of the patients was mild, and in vivo autoimmunity was uncommon and mild. Here we report in-depth analysis of T-cell function in two siblings with novel ICOS deficiency. While the brother displayed mild skin infections, psoriasis-like skin region, and defective immunoglobulin class switching, the sister had more severe symptoms, which included immunodeficiency, rheumatoid arthritis, inflammatory bowel disease, interstitial pneumonitis, and psoriasis. Despite of normal CD3/CD28-induced proliferation and IL-2 production in vitro, peripheral blood T-cells from both patients demonstrated decreased percentage of CD4 central and effector memory T-cells and impaired production of Th1, Th2, and Th17 cytokines upon CD3/CD28 costimulation or upon PMA/ionophore stimulation. The defective polarization into effector cells were associated with impaired induction of T-bet, GATA3 and MAF and RORC. Reduced CTLA-4+CD45RO+ FoxP3+ regulatory T-cells and diminished induction of inhibitory cell surface molecules including CTLA-4 were also observed in the patients. Further analysis of the gene expression and immune functions of the patients demonstrated increased induction of RANKL, lack of IFN-g response, and loss of Itch expression upon activation in the female case with autoimmunity. Our study suggests extensive T-cell dysfunction and loss of balance between effector cells and regulatory cells in the ICOS-deficient patients may account for their immunodeficiency and/or autoimmune disorder.
Impaired CD4 and CD8 effector function and decreased memory T cell populations in ICOS-deficient patients.
No sample metadata fields
View SamplesEstrogen clearly prevents osteoporotic bone loss by attenuating bone resorption. The molecular basis of how this is accomplished, however, remains elusive. Here we report a critical role of osteoclastic ERa in mediating estrogen action on bone in females. We selectively ablated ERa in differentiated osteoclasts (ERa dOc/dOc). ERa dOc/dOc females, but not males, exhibited clear trabecular bone loss, similar to the osteoporotic bone phenotype in post-menopausal women. Recovery of bone loss by estrogen treatment of the ovariectomized ERa dOc/dOc females was ineffective in the trabecular areas of the long bones and lumbar vertebral bodies. Osteoclastic apoptosis, induced by estrogen, occurred simultaneously with up-regulation of Fas ligand (FasL) expression in intact trabecular bones of ERa +/+mice, but not in ERa dOc/dOc mice. ERa was also required for similar effects of estrogen and tamoxifen in cultured osteoclasts. These findings suggest that the osteoprotective actions of estrogen and SERMS are mediated at least in part through osteoclastic ERa in trabecular bone; and the life span of mature osteoclasts is regulated through activation of the Fas/FasL system.
Estrogen prevents bone loss via estrogen receptor alpha and induction of Fas ligand in osteoclasts.
Sex, Specimen part
View SamplesLamin A/C was ablated in pancreatic acinar cells using Elastase1 driven, Cre-ErT mediated, LoxP recombination, causing excision of exons 10 and 11 of the Lmna gene
Lamin A/C Maintains Exocrine Pancreas Homeostasis by Regulating Stability of RB and Activity of E2F.
Sex
View SamplesSome neuropsychiatric disease, including schizophrenia, may originate during prenatal development, following periods of gestational hypoxia and placental oxidative stress. Here we investigated if gestational hypoxia promotes damaging secretions from the placenta that affect fetal development and whether a mitochondria-targeted antioxidant MitoQ might prevent this. Gestational hypoxia caused low birth-weight and changes in young adult offspring brain, mimicking those in human neuropsychiatric disease. Exposure of cultured neurons to fetal plasma or to secretions from the placenta or from model trophoblast barriers that had been exposed to altered oxygenation caused similar morphological changes. The secretions and plasma contained altered microRNAs whose targets were linked with changes in gene expression in the fetal brain and with human schizophrenia loci. Molecular and morphological changes in vivo and in vitro were prevented by a single dose of MitoQ bound to nanoparticles, which were shown to localise and prevent oxidative stress in the placenta but not in the fetus. We suggest the possibility of developing preventative treatments that target the placenta and not the fetus to reduce risk of psychiatric disease in later life. Overall design: 16 samples (4 biological replicates per group) were analysed using RNA sequencing. The 4 groups were: Normoxia+Saline (control sample), Normoxia+MitoQ-NP, Hypoxia+Saline and Hypoxia+MitoQ-NPs. Pair-wise comparison between all groups was performed.
Treating the placenta to prevent adverse effects of gestational hypoxia on fetal brain development.
No sample metadata fields
View SamplesThe zebrafish has the capacity to regenerate its heart after severe injury. While the function of a few genes during this process has been studied, we are far from fully understanding how genes interact to coordinate heart regeneration. To enable systematic insights into this phenomenon, we generated and integrated a dynamic co-expression network of heart regeneration in the zebrafish and linked systems-level properties to the underlying molecular events. Across multiple post-injury time points, the network displays topological attributes of biological relevance. We show that regeneration steps are mediated by modules of transcriptionally coordinated genes, and by genes acting as network hubs. We also established direct associations between hubs and validated drivers of heart regeneration with murine and human orthologs. The resulting models and interactive analysis tools are available at http://infused.vital-it.ch. Using a worked example, we demonstrate the usefulness of this unique open resource for hypothesis generation and in silico screening for genes involved in heart regeneration.
Analysis of the dynamic co-expression network of heart regeneration in the zebrafish.
Specimen part
View SamplesAnalysis of a SigX knockout mutant of Pseudomonas aeruginosa H103 strain in LB.
The absence of SigX results in impaired carbon metabolism and membrane fluidity in Pseudomonas aeruginosa.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Broad and Largely Concordant Molecular Changes Characterize Tolerogenic and Immunogenic Dendritic Cell Maturation in Thymus and Periphery.
Specimen part, Treatment
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