Akt1, a serine-threonine protein kinase member of the PKB/Akt gene family, plays a critical role in the regulation of several cellular processes including cell proliferation and apoptosis. In this study, we utilized Akt1+/+ and Akt1-/- C57/Bl6 female mice to demonstrate that Akt1 is required for normal mammary gland postnatal development and homeostasis. Akt1 deficiency resulted in severely delayed postnatal mammary gland growth as well as a significant decrease in the number of terminal end buds during puberty. Adult Akt1-/- mammary glands exhibited significantly fewer alveolar buds coupled with a significant increase in epithelial cell apoptosis compared to their wild-type counterparts. Microarray analysis revealed that Akt1 deficiency resulted in several altered gene expression changes and biological processes in adult mammary glands, including organismal development, cell death, and tissue morphology. Of particular importance, a significant decrease in expression of Btn1a1, a gene involved in milk lipid secretion, was observed in Akt1-/- mammary glands by both microarray and RT-PCR validation.
Akt1 is essential for postnatal mammary gland development, function, and the expression of Btn1a1.
Sex
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Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex.
Specimen part
View SamplesGestational diabetes mellitus (GDM) affects approximately 18% of pregnancies in the United States and increases the risk of adverse health outcomes in the offspring. These adult disease propensities may be set by anatomical and molecular alterations in the placenta associated with GDM. To assess the mechanistic aspects of fetal programming, we measured genome-wide methylation (Infinium HumanMethylation450 Beadchips) and expression (Affymetrix Transcriptome Microarrays) in placental tissue of 41 GDM cases and 41 matched pregnancies without maternal complications from the Harvard Epigenetic Birth Cohort. Specific transcriptional and epigenetic perturbations associated with GDM status included alterations in the major histocompatibility complex (MHC) region, which were validated in an independent cohort, the Rhode Island Child Health Study. Gene ontology enrichment among gene regulation influenced by GDM revealed an over-representation of immune response pathways among differential expression, reflecting these coordinated changes in the MHC region. Our study represents the largest investigation of transcriptomic and methylomic differences associated with GDM, providing comprehensive insight into the molecular basis of GDM induced fetal (re)programming.
Epigenome-wide and transcriptome-wide analyses reveal gestational diabetes is associated with alterations in the human leukocyte antigen complex.
Specimen part
View SamplesEpigenetic events, including covalent post-translational modification of histones, have frequently been demonstrated to play critical roles in tumor development and progression. The transcriptional coactivator, p300/CBP, possesses both histone acetyltransferase (HAT) activity as well as scaffolding properties that directly influence transcriptional activation of targeted genes. We have used a recently reported small molecule inhibitor of p300 HAT activity, C646, to explore the specific contribution of p300/CBP HAT activity to tumor development and progression. We find that C646 inhibits the growth of lineage-specific tumor cell lines including human melanomas through direct transcriptional regulation of cell cycle regulatory proteins. Further evaluation of the p300 HAT transcriptome in human melanoma cells using comprehensive gene expression profiling reveals that p300 HAT activity globally promotes cell cycle progression, nucleosome assembly, and the DNA damage checkpoint through direct transcriptional regulatory mechanisms. Additionally, C646 promotes sensitivity to DNA damaging agents leading to enhanced apoptosis of melanoma cells following combination treatment with cisplatin. Together our data suggest that p300 HAT activity regulates critical growth regulatory pathways in tumors and may serve as a novel therapeutic target for melanoma and other malignancies by promoting cellular responses to DNA damaging agents.
Selective inhibition of p300 HAT blocks cell cycle progression, induces cellular senescence, and inhibits the DNA damage response in melanoma cells.
Cell line, Treatment, Time
View SamplesCD4+ T cell help is critical for optimal CD8+ T cell expansion after priming in many experimental systems. However, a role for CD4+ T cells in regulating the initial steps of CD8+ T cell effector differentiation is not well established. Here we demonstrate that absence of CD4+ T cells at the time of replication-incompetent adenovirus vector immunization of C57BL/6 mice led to immediate CD8+ T cell dysfunction characteristic of exhaustion at the first detectable timepoints as well as impaired expansion of antigen-specific CD8+ T cells. The absence of CD4+ T cell help resulted in antigen-specific CD8+ T cells that had reduced ex vivo cytotoxicity and decreased capacity to produce IFN- and TNF-. CD8+ T cells primed in the absence of CD4+ T cells expressed elevated levels of the inhibitory receptors PD-1, LAG-3, and Tim-3, and these cells exhibited transcriptomic exhaustion profiles by gene set enrichment analysis. This dysfunctional state was imprinted within 3 days of immunization and could not be reversed by provision of CD4+ T cell help after priming. Partial rescue of unhelped CD8+ T cell expansion and effector differentiation could be achieved by PD-1 pathway blockade or recombinant IL-2 administration.
Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells.
Specimen part, Time
View SamplesExhaustion markers are expressed by T lymphocytes in Follicular Lymphoma (FL). Through these, TIM-3 has been recently identified as a poor pronostic factor when expressed by FL CD4+ T cells.
Impaired functional responses in follicular lymphoma CD8<sup>+</sup>TIM-3<sup>+</sup> T lymphocytes following TCR engagement.
Specimen part, Subject
View SamplesCD4 T cells promote innate and adaptive immune responses, but how vaccine-elicited CD4 T cells contribute to immune protection remains unclear.
Vaccine-elicited CD4 T cells induce immunopathology after chronic LCMV infection.
Specimen part, Time
View SamplesObesity is linked to the development of metabolic disorders. Expansion of white adipose tissue (WAT) from hypertrophy of pre-existing adipocytes and/or differentiation of precursors into new mature adipocytes contributes to obesity. We found that Nck2 expression is largely restricted to WAT, raising the hypothesis that it may play a unique function in that tissue. Using mice lacking Nck2, we found that Nck2 regulates adipocyte hypertrophy thus contributing to increased adiposity and progressive glucose intolerance, insulin resistance and hepatic steatosis. These findings were recapitulated in humans such that Nck2 expression in omental WAT was inversely correlated with the degree of obesity. Mechanistically, Nck2 deficiency promoted the induction of an adipocyte differentiation program and signaling by the PERK-eIF2a-ATF4 pathway in agreement with a role for the unfolded protein response in adipogenesis. These findings uncover Nck2 as a novel regulator of adipogenesis and that perturbation in its functionality contributes to adiposity-related metabolic disorders. Overall design: Differential gene expression profile between epididymal white adipose tissue of Nck2-/- and Nck2+/+ mice by RNA sequencing (Illumina HiSEq 2000)
Nck2 Deficiency in Mice Results in Increased Adiposity Associated With Adipocyte Hypertrophy and Enhanced Adipogenesis.
No sample metadata fields
View SamplesThe white adipose tissue (WAT) rapidly loses mass when mice are fed a diet containing trans-10, cis-12 conjugated linoleic acid (t10c12 CLA). A microarray analysis of WAT due to CLA feeding was performed to better define the processes and genes involved. WAT weight decreased by ca. 80% over 17 days of feeding a 0.5% t10c12 CLA diet. The lipid volume decreased by 90% and the number of adipocytes and total cells were reduced by15% and 47%, respectively. Microarray profiling of replicated pools of control and treated mice (n=140) at seven time points over the 17day feeding indicated between 2798 to 4318 genes showed mRNA changes of 2-fold or more. Transcript levels for genes of glucose and fatty acid import or biosynthesis were significantly reduced. A prolific inflammation response was indicated by the 2 to100-fold induction of many cytokine transcripts, including those for IL-6, IL1?, TNF ligands, and CXC family members
Trans-10, cis-12 conjugated linoleic acid causes inflammation and delipidation of white adipose tissue in mice: a microarray and histological analysis.
Age
View SamplesZika virus (ZIKV) is responsible for a major current outbreak in the Americas and has been causally associated with fetal microcephaly as well as Guillain-Barre syndrome in adults. However, the immune responses associated with controlling ZIKV replication remain poorly characterized. Here we report a detailed analysis of innate and adaptive immune responses following ZIKV infection in 16 rhesus monkeys. A robust proinflammatory innate immune response was observed within the first few days of infection, including upregulation of type 1 interferon, which correlated directly with viral loads. Immunomodulatory pathways, including IL-10 and TGF-, were also upregulated. ZIKV-specific neutralizing antibodies emerged rapidly by day 7 and correlated inversely with viral loads, which were undetectable in peripheral blood by day 6-10. In contrast, virus replication persisted in cerebrospinal fluid (CSF) for at least 21-42 days in 75% (3 of 4) of the monkeys that received the lowest dose of ZIKV tested, and ZIKV-specific antibodies were essentially undetectable in CSF. These data suggest that antibodies play a critical role in the rapid control of acute viremia in the periphery but were largely excluded from the central nervous system, allowing viral persistence at this immuonoprivileged site.
Zika Virus Persistence in the Central Nervous System and Lymph Nodes of Rhesus Monkeys.
Time
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