Background: Thiazolidinediones (TZDs) activate peroxisome proliferator-activated receptor gamma (PPARgamma) and are used clinically to help restore peripheral insulin sensitivity in Type 2 diabetes (T2DM). Interestingly, long-term treatment of mouse models of Alzheimers disease (AD) with TZDs also has been shown to reduce several well-established brain biomarkers of AD including inflammation, oxidative stress and Abeta accumulation. While some of the TZD actions are becoming clear in AD models and may mediate their reported beneficial impact in AD patients, little is known about the functional consequences of TZDs in animal models of normal aging. Because aging is a common risk factor for both AD and T2DM, we investigated whether the TZD, pioglitazone could alter brain aging under non-pathological conditions. Findings: The TZD pioglitazone (PIO) was incorporated into the diet to yield a final dose of approximately 2.3 mg/kg body weight/day. PIO reduced insulin levels irrespective of age. Interestingly, a significant reduction in the Ca2+-dependent afterhyperpolarization was seen in the aged animals with no significant change in LTP maintenance or learning and memory performance. Finally, a combination of microarray analyses on hippocampal tissue and serum-based multiplex cytokine assays revealed that age-dependent inflammatory changes in brain and periphery were not reversed by PIO.
Effects of long-term pioglitazone treatment on peripheral and central markers of aging.
Sex, Age
View SamplesThiazolidinediones (TZDs) are agonists at peroxisome proliferator-activated gamma-type (PPAR-y) receptors and are used clinically for the treatment of type 2 diabetes where they have been shown to reestablish insulin sensitivity, improve lipids profile, and reduce inflammation. Recent work also suggests that TZDs may be beneficial in Alzheimer's disease (AD), ameliorating cognitive decline early in the disease process. However, there have been only a few studies identifying mechanisms through which cognitive benefits may be exerted. Starting at 10 months of age, the triple transgenic mouse model of AD (3xTg-AD) with accelerated amyloid-B (AB) deposition and tau pathology was treated with the TZD pioglitazone (PIO- Actos) at 18 mg/Kg body weight/day. After four months, PIO-treated animals showed multiple beneficial effects, including improved learning on the active avoidance task, reduced serum cholesterol, decreased hippocampal AB deposits, and enhanced short- and long-term plasticity. Baseline electrophysiological membrane properties and blood glucose levels were unchanged by PIO treatment. Gene microarray analyses of hippocampal tissue identified predicted transcriptional responses following TZD treatment as well as potentially novel targets of TZDs, including facilitation of estrogenic processes, and decreases in glutamatergic and ketone metabolic/ cholesterol dependent processes. Taken together, these results confirm prior animal studies showing that TZDs can ameliorate cognitive deficits associated with AD-related pathology, but also extend these findings by pointing to novel molecular targets in the brain.
Long-term pioglitazone treatment improves learning and attenuates pathological markers in a mouse model of Alzheimer's disease.
Sex, Age
View SamplesNotch signaling is widely implicated in mouse mammary gland development and tumorigenesis. To investigate the effects of acute activation of Notch signaling in the mammary epithelial compartment, we generated bi-transgenic MMTV-rtTA; TetO-NICD1 (MTB/TICNX) mice that conditionally express a constitutively active NOTCH1 intracellular domain (NICD1) construct in the mammary epithelium upon doxycycline administration.
Notch promotes recurrence of dormant tumor cells following HER2/neu-targeted therapy.
Sex, Age, Specimen part, Treatment, Time
View SamplesPotassium is one of the essential macronutrients required for plant growth and development. It plays a major role in different physiological processes like cell elongation, stomatal movement, turgor regulation, osmotic adjustment, and signal transduction by acting as a major osmolyte and component of the ionic environment in the cytosol and subcellular organelles.
Gene expression analysis of rice seedling under potassium deprivation reveals major changes in metabolism and signaling components.
Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Knockout of G protein β5 impairs brain development and causes multiple neurologic abnormalities in mice.
Specimen part
View SamplesGb5 is a divergent, evolutionarily-conserved, member of the heterotrimeric G protein b subunit family that is expressed principally in brain and neuronal tissue. Among Gb isoforms, Gb5 is unique in its ability to heterodimerize with members of the R7 subfamily of the regulator of G protein signaling (RGS) proteins that contain G protein-g like (GGL) domains. Previous studies employing Gb5 knockout mice have shown that Gb5 is an essential stabilizer of GGL domain-containing RGS proteins and regulates the deactivation of retinal phototransduction and the proper functioning of retinal bipolar cells. The purpose of this study is to better understand the functions of Gb5 in the brain outside the visual system by employing molecular biology, immunohistochemistry and confocal imaging technologies. We show here that mice lacking Gb5 have a markedly abnormal neurologic phenotype that includes neurobehavioral developmental delay, wide-based gait, motor learning and coordination deficiencies, and hyperactivity. Using immunohistochemical analysis and a green fluorescent reporter of Purkinje cell maturation we show that the phenotype of Gb5-deficient mice includes, in part, delayed development of the cerebellar cortex, an abnormality that likely contributes to the neurobehavioral phenotype. Multiple neuronally-expressed genes are dysregulated in non-cerebellar portion of Gb5 KO mice.
Knockout of G protein β5 impairs brain development and causes multiple neurologic abnormalities in mice.
Specimen part
View SamplesGb5 is a divergent, evolutionarily-conserved, member of the heterotrimeric G protein b subunit family that is expressed principally in brain and neuronal tissue. Among Gb isoforms, Gb5 is unique in its ability to heterodimerize with members of the R7 subfamily of the regulator of G protein signaling (RGS) proteins that contain G protein-g like (GGL) domains. Previous studies employing Gb5 knockout mice have shown that Gb5 is an essential stabilizer of GGL domain-containing RGS proteins and regulates the deactivation of retinal phototransduction and the proper functioning of retinal bipolar cells. The purpose of this study is to better understand the functions of Gb5 in the brain outside the visual system by employing molecular biology, immunohistochemistry and confocal imaging technologies. We show here that mice lacking Gb5 have a markedly abnormal neurologic phenotype that includes neurobehavioral developmental delay, wide-based gait, motor learning and coordination deficiencies, and hyperactivity. Using immunohistochemical analysis and a green fluorescent reporter of Purkinje cell maturation we show that the phenotype of Gb5-deficient mice includes, in part, delayed development of the cerebellar cortex, an abnormality that likely contributes to the neurobehavioral phenotype. Multiple neuronally-expressed genes are dysregulated in cerebellum of Gb5 KO mice.
Knockout of G protein β5 impairs brain development and causes multiple neurologic abnormalities in mice.
Specimen part
View SamplesCK1-alpha-LS was knocked down in human coronary artery smooth muscle cells. Gene level and exon level changes in expression were assessed.
Protein kinase CK1alphaLS promotes vascular cell proliferation and intimal hyperplasia.
Specimen part
View SamplesThe pervasive nature of RNA polymerase II (Pol II) transcription requires efficient termination. A key player in this process is the cleavage and polyadenylation (CPA) factor PCF11, which directly binds to the Pol II C-terminal domain and dismantles elongating Pol II from DNA in vitro. We demonstrate that PCF11-mediated termination is essential for vertebrate development. A range of genomic analyses, including: mNET-seq, 3' mRNA-seq, chromatin RNA-seq and ChIP-seq, reveals that PCF11 enhances transcription termination and stimulates early polyadenylation genome-wide. PCF11 binds preferentially between closely spaced genes, where it prevents transcriptional interference and downstream gene silencing. Notably, PCF11 is sub-stoichiometric to the CPA complex. Low levels of PCF11 are maintained by an auto-regulatory mechanism involving premature termination of its own transcript, and are important for normal development. Both in human cell culture and during zebrafish development, PCF11 selectively attenuates the expression of other transcriptional regulators by premature CPA and termination. Overall design: Semi-nascent transcriptome measured by chromatin-bound RNA-seq in HeLa cells. Control and PCF11 knock-down (2 biological replicates) and control and PCF11 PAS1 deletion (4 biological replicates).
Selective Roles of Vertebrate PCF11 in Premature and Full-Length Transcript Termination.
Specimen part, Subject
View SamplesTo gain insight into the changes in gene expression pattern upon Ebola infection, CD45+/+ (100% protein level) and CD45+/- (62% protein level) mice were challenged with mouse adapted Ebola virus. At time-points day 0, 1, 3, 5, 7, 9, 11 and 13, spleen tissue was harvested and splenocytes isolated. Total RNA was isolated for mRNA expression analysis. The mouse genome 430 2.0 array (Affymetrix, Inc.), which consists of over 39,000 genes in a single array, was used. Based on gene expression patterns, the variable genes were grouped into sixteen clusters. Each cluster contained genes associated with cellular immune processes, signaling, cell-cycle, complement coagulation cascade, biosynthesis/metabolism, ubiquitous genes involved in several cascades, and genes of unknown function. Interestingly, gene expression in clusters 2 and 3 were significantly downregulated by day 1 following EBOV challenge in CD45100% mice. In contrast, at day 1 following EBOV infection, the CD45 62% mice maintained gene expression patterns similar to day 0. The differences in gene expression patterns between the CD45 100% and CD45 62% splenocytes were less apparent at day 3 following infection and by days 5 and 7 they became very similar. At day 9, when wild-type mice had succumbed to the disease, the pattern in CD45 62% mice remained similar to the day 7 patterns of CD45 100% and CD45 62% mice. The pattern at days 11 and 13 in the CD45 62% mice had returned to that of day 0 CD45 100% or CD45 62% mice. These results suggested that in CD45 100% mice, subversion of the cell transcriptional machinery during the early stages of EBOV infection (day 1) might represent a major factor leading to death of the mice. In CD45 62% mice, early control of gene regulation likely provided the appropriate antiviral responses leading to regulated inflammation, immune co-stimulation, and survival.
Reduced levels of protein tyrosine phosphatase CD45 protect mice from the lethal effects of Ebola virus infection.
Specimen part
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