The perinatal period and early infancy are considered critical periods for lung development, and adversities during this period are believed to impact lung health in adulthood.The main factors affecting postnatal lung development and growth include environmental exposures, cigarette smoking, (viral) infections, allergic sensitization, and asthma.Therefore, we hypothesized that concomitant exposure in the early postnatal period in mice would cause more profound alterations in lung alveolarization and growth in adult life, quantified by stereology, and differently modulate lung inflammation and gene expression than either insult alone.Five-day-old male mice were immunized intraperitoneally (i.p.) with 10 µg of ovalbumin (OVA). This procedure was repeated at the 7th day of life, animals from the control group received i.p. injection of PBS only. Mice were exposed to either ambient PM2.5 or filtered air from the 5th to the 39th day of life, using an ambient particle concentrator developed at the Harvard School of Public Health (HAPC).Total RNA of lung samples (n=3 animals per group) was extracted using RNeasy Mini Kit (Qiagen, Hilden, Germany), according to manufacturer's instructions. The microarray analysis was performed using three RNA samples for each studied group (Control, OVA, PM2.5, OVA+PM2.5), totalizing 12 samples. One hundred nanograms of total RNA was amplified with the Ambion WT Expression Kit and hybridized onto the GeneChip Mouse Gene 2.0 ST Array (Thermo Scientific, Massachusetts, USA), following manufacturer’s protocol. The comparison between the control and OVA group exhibit 32 DEGs (28 up-regulated and 4 down-regulated), between the control and PM2.5 group had 6 DEGs (4 up and 2 down) and between the control and OVA+PM2.5 group had 5 DEGs (4 up and 1 down). The comparison between OVA and PM2.5 group showed 97 DEGS (22 up and 75 down) and between OVA and OVA+PM2.5 group had 7 DEGs (4 up and 3 down). Finally, the comparison between the PM2.5 and OVA+PM2.5 group exhibit 34 DEGs (2 up and 32 down).Our experimental data provide pathological support for the hypothesis that either allergic or environmental insults in early life have permanent adverse consequences to lung growth. In addition, combined insults were associated with the development of a COPD-like phenotype in young adult mice.
Allergic sensitization and exposure to ambient air pollution beginning early in life lead to a COPD-like phenotype in young adult mice.
Treatment
View SamplesWallerian degeneration (WD) involves the fragmentation of axonal segments disconnected from their cell bodies, segmentation of the myelin sheath, and removal of debris by Schwann cells and immune cells. The removal and downregulation of myelin-associated inhibitors of axonal regeneration and synthesis of growth factors by these two cell types are critical responses to successful nerve repair. Here, we analyzed the transcriptome of the sciatic nerve of mice carrying the Wallerian degeneration slow (WldS) mutant gene, a gene that confers axonal protection in the distal stump after injury, therefore causing significant delays in WD, neuroinflammation, and axonal regeneration.
Transcriptional profiling of the injured sciatic nerve of mice carrying the Wld(S) mutant gene: identification of genes involved in neuroprotection, neuroinflammation, and nerve regeneration.
Specimen part, Time
View SamplesThe efficacy and exceptionally good tolerance of estrogen blockade in the treatment of breast cancer is well recognized but novel agents are required, especially to take advantage of the multiple consecutive responses obtained in breast cancer progressing following previous hormone therapy, thus delaying the use of cytotoxic chemotherapy with its usually serious side effects. Acolbifene (ACOL) is a novel and unique antiestrogen completely free of estrogen-like activity in both the mammary gland and uterus while preventing bone loss. From the preclinical and clinical data so-far available, this new antiestrogen represents a unique opportunity for a highly potent and specific blockade of estrogen action in the mammary gland and uterus while exerting estrogen-like beneficial effects in other tissues (selective estrogen receptor modulator or SERM activity). In order to better understand the specificity of action of acolbifene, we have used Affymetrix GeneChips containing 45,000 probe sets to analyze 34,000 genes to determine the specificity of this compound compared to the pure antiestrogen fulvestrant, as well as the mixed antagonists/agonists tamoxifen and raloxifene to block the effect of estradiol (E2) and to induce effects of their own on gene expression in the mouse mammary gland. The genes modulated by E2 were those identified in two separate experiments and validated by quantitative real-time PCR (Q_RT-PCR). Three hours after the single subcutaneous injection of E2 (0.05 ug), the simultaneous administration of acolbifene, fulvestrant, tamoxifen and raloxifene blocked by 98%, 62%, 43% and 92% the number of E2-upregulated genes, respectively. On the other hand, 70%, 10%, 25% and 55% of the genes down-regulated by E2 were blocked by the same compounds. Acolbifene was also the compound which, when used alone, modulated the smallest number of genes also influenced by E2, namely 4%, thus possibly explaining the potent tumoricidal action of this compound in human breast cancer xenografts where 61% of tumors disappeared, thus bringing a new paradigm in the hormonal therapy of breast cancer.
Specific transcriptional response of four blockers of estrogen receptors on estradiol-modulated genes in the mouse mammary gland.
Specimen part, Treatment
View SamplesPurpose: The DBA/2J mouse is a model for secondary angle-closure glaucoma due to iris atrophy and pigment dispersion, which ultimately leads to increased intraocular pressure (IOP). We sought to correlate changes in retinal gene expression with glaucoma-like pathology by performing microarray analysis of retinal RNA from DBA/2J mice at 3 months before disease onset, and at 8 months, after IOP elevation. Methods: IOP was monitored monthly in DBA/2J animals by Tono-Pen and animals with normal (3 months) or elevated IOP (8 months) were identified. RNA was prepared from 3 individual retinas at each age, and the RNA was amplified and used to generate biotin-labeled probe for high density mouse Affymetrix arrays (U430.2). A subset of genes was selected for confirmation by quantitative RT-PCR using independent retina samples from DBA/2J animals at 3, 5 and 8 months of age, and compared to retinas from C57BL/6J control animals at 3 and 8 months. Results: There were changes in expression of 68 genes, with 32 genes increasing and 36 genes decreasing at 8 months versus 3 months. Upregulated genes were associated with immune response, glial activation, signaling and gene expression, while down-regulated genes included multiple crystallin genes. Significant changes in 9 upregulated genes and 2 downregulated genes were confirmed by quantitative RT-PCR, with some showing changes in expression by 5 months. Conclusions: DBA/2J retina shows evidence for glial activation and an immune-related response following IOP elevation, similar to what has been reported following acute elevation of IOP in other models.
Microarray analysis of retinal gene expression in the DBA/2J model of glaucoma.
Age
View SamplesThe major myeloid blood cell lineages, including erythrocytes, platelets, granulocytes and macrophages, are generated from hematopoietic stem cells (HSC) by differentiation through a series of increasingly more committed progenitor cells. Precise phenotypic identification and functional characterization of such intermediate progenitors has important consequences for understanding fundamental differentiation processes and is clinically relevant since such events become dysregulated in various disease settings, including leukemia. While previous studies have suggested a hierarchy for myeloid differentiation involving a common progenitor through which all myeloid lineages are derived, several recent studies have suggested that such a developmental intermediate might not be an absolute requirement. Here, we evaluated the functional in vitro and in vivo potentials of a range of prospectively isolated myeloid precursors with differential expression of CD150, Endoglin and CD41. Our studies reveal a complex hierarchy of myeloerythroid progenitors with distinct and developmentally restricted lineage potentials. Global gene expression signatures of these cellular subsets revealed expression patterns consistent with their functional capacities, while hierarchical clustering analysis provides details on their lineage relationships. These data challenge existing models of hematopoietic differentiation, by suggesting that progenitors of the innate and adaptive immune system in the adult separate late, and to a large extent, following the divergence of megakaryocytic/erythroid potential.
Elucidation of the phenotypic, functional, and molecular topography of a myeloerythroid progenitor cell hierarchy.
No sample metadata fields
View SamplesGene expression profiling using microarray has been limited to profiling of differentially expressed genes at comparison setting since probesets for different genes have different sensitivities. We overcome this limitation by using a very large number of varied microarray datasets as a common reference, so that statistical attributes of each probeset, such as dynamic range or a threshold between low and high expression can be reliably discovered through meta-analysis. This strategy is implemented in web-based platform named Gene Expression Commons (http://gexc.stanford.edu/ ) with datasets of 39 distinct highly purified mouse hematopoietic stem/progenitor/functional cell populations covering almost the entire hematopoietic system. Since the Gene Expression Commons is designed as an open platform, any scientist can explore gene expression of any gene, search by expression pattern of interest, submit their own microarray datasets, and design their own working models.
Gene Expression Commons: an open platform for absolute gene expression profiling.
Sex, Age
View SamplesThe 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 SamplesUsing EphB2 or the ISC marker Lgr5, we have FACS-purified and profiled intestinal stem cells (ISCs), crypt proliferative progenitors and late transient amplifying cells to define a gene expression program specific for normal ISCs.
The intestinal stem cell signature identifies colorectal cancer stem cells and predicts disease relapse.
Specimen part
View SamplesEpigenetic modifications must underlie lineage-specific differentiation since terminally differentiated cells express tissue-specific genes, but their DNA sequence is unchanged. Hematopoiesis provides a well-defined model of progressive differentiation in which to study the role of epigenetic modifications in cell fate decisions. Multi-potent progenitors (MPPs) can differentiate into all blood cell lineages, while downstream progenitors commit to either myeloerythroid or lymphoid lineages. While DNA methylation is critical for myeloid versus lymphoid differentiation, as demonstrated by the myeloerythroid bias in Dnmt1 hypomorphs {Broske, 2009 #6}, a comprehensive DNA methylation map of hematopoietic progenitors, or of any cell lineage, does not exist. Here we have generated a mouse DNA methylation map, examining 4.6 million CpG sites throughout the genome including all CpG islands and shores, examining MPPs, all lymphoid progenitors (ALPs), common myeloid progenitors (CMPs), granulocyte/macrophage progenitors (GMPs), and thymocyte progenitors (DN1, DN2, DN3). Interestingly, differentiation towards the myeloid lineage corresponds with a net decrease in DNA methylation, while lymphoid commitment involves a net increase in DNA methylation, but both show substantial dynamic changes consistent with epigenetic plasticity during development. By comparing lineage-specific DNA methylation to gene expression array data, we find many examples of genes and pathways not previously known to be involved in lymphoid/myeloid differentiation, such as Gcnt2, Arl4c, Gadd45, and Jdp2. Several transcription factors, including Meis1 and Prdm16 were methylated and silenced during differentiation, suggesting a role in maintaining an undifferentiated state. Additionally, epigenetic modification of modifiers of the epigenome appears to be important in hematopoietic differentiation. Our results directly demonstrate that modulation of DNA methylation occurs during lineage-specific differentiation, often correlating with gene expression changes, and define a comprehensive map of the methylation and transcriptional changes that accompany myeloid versus lymphoid fate decisions.
Comprehensive methylome map of lineage commitment from haematopoietic progenitors.
Sex, Age
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
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