Despite advances in investigating functional aspects of osteoblast (OB) differentiation, especially studies on how bone proteins are deposited and mineralized, there has been little research on the intracellular trafficking of bone proteins during OB differentiation. Collagen synthesis and secretion is markedly upregulated upon Ascorbic Acid (AA) stimulation. Understanding the mechanism by which collagen is mobilized in specialized OB cells is important for both basic cell biology and diseases involving defects in bone secretion and deposition. RabGTPases are major regulators on protein trafficking throughout the cell. In this study, we identified the Rab GTPases that are upregulated during 5-day AA differentiation of OBs using microarray analysis, namely Rab1, Rab3d and Rab27b.
Rab GTPase mediated procollagen trafficking in ascorbic acid stimulated osteoblasts.
Specimen part, Cell line
View SamplesThe recent identification of cancer stem cells (CSCs) in multiple human cancers provides a new inroad to understanding tumorigenesis at the cellular level. CSCs are defined by their characteristics of self-renewal, multipotentiality, and tumor initiation upon transplantation. By testing for these defining characteristics, we provide evidence for the existence of CSCs in a transgenic mouse model of glioma, S100-verbB;Trp53. In this glioma model, CSCs are enriched in the side-population (SP) cells. These SP cells have enhanced tumor-initiating capacity, self-renewal, and multipotentiality compared to non-SP cells from the same tumors. Furthermore, gene expression analysis comparing FACS-sorted cancer SP cells to non-SP cancer cells and normal neural SP cells identified 45 candidate genes that are differentially expressed in glioma stem cells. We validated the expression of two genes from this list (S100a4 and S100a6) in primary mouse gliomas and human glioma samples. Analyses of xenografted human GBM (glioblatoma multiforme) cell lines and primary human glioma tissues show that S100A4 and S100A6 are expressed in a small subset of cancer cells and that their abundance is positively correlated to tumor grade. In conclusion, this study shows that CSCs exist in a mouse glioma model, suggesting that this model can be used to study the molecular and cellular characteristics of CSCs in vivo and to further test the cancer stem cell hypothesis.
Cancer stem cells are enriched in the side population cells in a mouse model of glioma.
No sample metadata fields
View SamplesMurine models have been valuable instruments in defining the pathogenesis of diabetic nephropathy (DN), but they only partially recapitulate disease manifestations of human DN, limiting their utility . In order to define the molecular similarities and differences between human and murine DN, we performed a cross-species comparison of glomerular transcriptional networks. Glomerular gene expression was profiled in patients with early type 2 DN and in three mouse models (streptozotocin DBA/2 mice, db/db C57BLKS, and eNOS-deficient C57BLKS db/db mice). Species-specific transcriptional networks were generated and compared with a novel network-matching algorithm. Three shared, human-mouse cross-species glomerular transcriptional networks containing 143 (Human-STZ), 97 (Human- db/db), and 162 (Human- eNOS-/- db/db) gene nodes were generated. Shared nodes across all networks reflected established pathogenic mechanisms of diabetic complications, such as elements of JAK-STAT and VEGFR signaling pathways . In addition, novel pathways not formally associated with DN and cross-species gene nodes and pathways unique to each of the human-mouse networks were discovered. The human-mouse shared glomerular transcriptional networks will assist DN researchers in the selection of mouse models most relevant to the human disease process of interest. Moreover, they will allow identification of new pathways shared between mice and humans.
Identification of cross-species shared transcriptional networks of diabetic nephropathy in human and mouse glomeruli.
Age, Specimen part, Disease, Disease stage, Treatment
View SamplesAn alternative promoter of the PGC-1alpha gene gives rise to three new PGC-1alpha isoforms refered to as PGC-1a2 (A2), PGC-1a3 (A3) and PGC-1a4 (A4). The proximal PGC-1 alpha promotor transcribes the canonical PGC-1 alpha which is refered to as PGC-1a1 (A1).G1/G2/G3 samples refer to the Green fluorescent protein (GFP) control samples used in this experiment. Forced expression of the PGC-1a4 isoform results in muslce hypertrophy associated with increased IGF-1 signaling and repression of myostatin signaling.
A PGC-1α isoform induced by resistance training regulates skeletal muscle hypertrophy.
Specimen part
View SamplesPolyinosinic:polycytidylic acid (poly I:C) is a synthetic analogue of double-stranded (ds)RNA, a molecular pattern associated with viral infections, that is used to exacerbate inflammation in lung injury models. Despite its frequent use, there are no detailed studies of the responses elicited by a single topical administration of poly I:C to the lungs of mice. Our data provides the first demonstration that the molecular responses in the airways induced by poly I:C correlate to those observed in the lungs of COPD patients. These expression data also revealed three distinct phases of response to poly I:C, consistent with the changing inflammatory cell infiltrate in the airways. Poly I:C induced increased numbers of neutrophils and NK cells in the airways, which were blocked by CXCR2 and CCR5 antagonists, respectively. Using gene set variation analysis on representative data sets, gene sets defined by poly I:C-induced DEGs were enriched in the molecular profiles of chronic obstructive pulmonary disease (COPD), but not idiopathic pulmonary fibrosis patients. Collectively, these data represent a new approach for validating the clinical relevance of preclinical animal models and demonstrate that a dual CXCR2/CCR5 antagonist may be an effective treatment for COPD patients.
Double-stranded RNA induces molecular and inflammatory signatures that are directly relevant to COPD.
Sex, Specimen part, Time
View SamplesGenomic profiling of bleomycin- and saline-treated mice across 7 timepoints (1, 2, 7, 14, 21, 28, 35 days post treatment) was carried out in C57BL6/J mice to determine the phases of response to bleomycin treatment which correspond to onset of active pulmonary fibrosis.
Bleomycin induces molecular changes directly relevant to idiopathic pulmonary fibrosis: a model for "active" disease.
Sex, Specimen part, Treatment, Time
View SamplesCD38, a multi-functional membrane receptor and enzyme, consumes NAD+ to generate products such as cyclic-ADP-ribose. CD38 knockout mice show elevated tissue and blood NAD+ level. Chronic feeding of high-fat, high-sucrose diet to wild type mice leads to exercise intolerance and reduced metabolic flexibility. Loss of CD38 by genetic mutation protects mice from diet-induced metabolic deficit. These animal model results suggest that elevation of tissue NAD+ through genetic ablation of CD38 can profoundly alter energy homeostasis in animals that are maintained on a calorically-excessive Western diet.
Genetic Ablation of CD38 Protects against Western Diet-Induced Exercise Intolerance and Metabolic Inflexibility.
Specimen part
View SamplesIsoniazid induced varying degrees of hepatic steatosis in an inbred strain Mouse Diversity Panel (MDP) study. RNA was isolated from all animals for analysis of gene expression changes in the liver. The objective of this study was to identify gene expression changes that drive isoniazid-induced steatosis.
A systems biology approach utilizing a mouse diversity panel identifies genetic differences influencing isoniazid-induced microvesicular steatosis.
Sex, Specimen part, Treatment
View SamplesRationale: While modulation of the serotonin transporter (5HTT) has shown to be a risk factor for pulmonary arterial hypertension for almost 40 years, there is a lack of in vivo data about the broad molecular effects of pulmonary inhibition of 5HTT. Previous studies have suggested effects on inflammation, proliferation, and vasoconstriction. The goal of this study was to determine which of these were supported by alterations in gene expression in serotonin transporter knockout mice. Methods: Eight week old normoxic mice with a 5-HTT knock-out (5HTT-/-) and their heterozygote(5HTT+/-) or wild-type(5HTT+/+) littermates had right ventricular systolic pressure(RVSP) assessed, lungs collected for RNA, pooled, and used in duplicate in Affymetrix array analysis. Representative genes were confirmed by quantitative RT-PCR and western blot. Results: RVSP was normal in all groups. Only 124 genes were reliably changed between 5HTT-/- and 5HTT+/+ mice. More than half of these were either involved in inflammatory response or muscle function and organization; in addition, some matrix, heme oxygenase, developmental, and energy metabolism genes showed altered expression. Quantitative RT-PCR for examples from each major group confirmed changes seen by array, with an intermediate level in 5HTT+/- mice. Conclusions: These results for the first time show the in vivo effects of 5HTT knockout in lungs, and show that many of the downstream mechanisms suggested by cell culture and ex vivo experiments are also operational in vivo. This suggests that the effect of 5HTT on pulmonary vascular function arises from its impact on several systems, including vasoreactivity, proliferation, and immune function.
Gene expression in lungs of mice lacking the 5-hydroxytryptamine transporter gene.
No sample metadata fields
View SamplesFamilial pulmonary arterial hypertension (fPAH) is associated with mutations in BMPR2. Many of these mutations occur in the BMPR2 tail domain, leaving the SMAD functions intact. In order to determine the in vivo consequences of BMPR2 tail domain mutation, we created a smooth-muscle specific doxycycline inducible BMPR2 mutation with an arginine to termination mutation at amino acid 899. When these SM22-rtTA x TetO7-BMPR2R899X mice had transgene induced for 9 weeks, starting at 4 weeks of age, they universally developed pulmonary vascular pruning as assessed by fluorescent microangiography. Approximately half the time the induced animals developed elevated right ventricular systolic pressures (RVSP), associated with extensive pruning, muscularization of small pulmonary vessels, and development of large structural pulmonary vascular changes. These lesions included large numbers of macrophages and T-cells in their adventitial compartment, as well as CD133 positive cells in the lumen. Small vessels filled with CD45 positive and sometimes CD3 positive cells were a common feature in all SM22-rtTA x TetO7-BMPR2R899X mice. Gene array experiments show changes in stress response, muscle organization and function, proliferation and apoptosis, and developmental pathways before RVSP increases. Our results show that the primary phenotypic result of BMPR2 tail domain mutation in smooth muscle is pulmonary vascular pruning leading to elevated RVSP, associated with early dysregulation in multiple pathways with clear relevance to PAH. This model should be useful to the research community in examining early molecular and physical events in the development of PAH, and as a platform to validate potential treatments.
Mice expressing BMPR2R899X transgene in smooth muscle develop pulmonary vascular lesions.
No sample metadata fields
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