Search results for "Gene expression"
showing 10 items of 4085 documents
Influence of gene action across different time scales on behavior.
2002
Genes can affect natural behavioral variation in different ways. Allelic variation causes alternative behavioral phenotypes, whereas changes in gene expression can influence the initiation of behavior at different ages. We show that the age-related transition by honey bees from hive work to foraging is associated with an increase in the expression of the foraging ( for ) gene, which encodes a guanosine 3′,5′-monophosphate (cGMP)–dependent protein kinase (PKG). cGMP treatment elevated PKG activity and caused foraging behavior. Previous research showed that allelic differences in PKG expression result in two Drosophila foraging variants. The same gene can thus exert different types of influe…
Up-Regulation of leucocytes Genes Implicated in Telomere Dysfunction and Cellular Senescence Correlates with Depression and Anxiety Severity Scores
2012
BACKGROUND: Major depressive disorder (MDD) is frequently associated with chronic medical illness responsible of increased disability and mortality. Inflammation and oxidative stress are considered to be the major mediators of the allostatic load, and has been shown to correlate with telomere erosion in the leucocytes of MDD patients, leading to the model of accelerated aging. However, the significance of telomere length as an exclusive biomarker of aging has been questioned on both methodological and biological grounds. Furthermore, telomeres significantly shorten only in patients with long lasting MDD. Sensitive and dynamic functional biomarkers of aging would be clinically useful to eval…
Expression of Toll-Like Receptors in the Developing Brain
2012
Toll-like receptors (TLR) are key players of the innate and adaptive immune response in vertebrates. The original protein Toll in Drosophila melanogaster regulates both host defense and morphogenesis during development. Making use of real-time PCR, in situ hybridization, and immunohistochemistry we systematically examined the expression of TLR1-9 and the intracellular adaptor molecules MyD88 and TRIF during development of the mouse brain. Expression of TLR7 and TLR9 in the brain was strongly regulated during different embryonic, postnatal, and adult stages. In contrast, expression of TLR1-6, TLR8, MyD88, and TRIF mRNA displayed no significant changes in the different phases of brain develop…
Anti-Aging Effects of GDF11 on Skin
2020
International audience; Human skin is composed of three layers: the epidermis, the dermis, and the hypodermis. The epidermis has four major cell layers made up of keratinocytes in varying stages of progressive differentiation. Skin aging is a multi-factorial process that affects every phase of its biology and function. The expression profiles of inflammation-related genes analyzed in resident immune cells demonstrated that these cells have a strong ability to regenerate adult skin stem cells and to produce endogenous substances such as growth differentiation factor 11 (GDF11). GDF11 appears to be the key to progenitor proliferation and/or differentiation. The preservation of youthful phenot…
Hormonal regulation of S-adenosylmethionine synthase transcripts in pea ovaries
1996
Two cDNA clones coding for S-adenosyl-L-methionine synthase (SAMs, EC 2.5.1.6) have been isolated from a cDNA library of gibberellic acid-treated unpollinated pea ovaries. Both cDNAs were sequenced showing a high degree of identity but coding for different SAMs polypeptides. The presence of two SAMs genes in pea was further confirmed by Southern analysis. Expression of the SAMs genes in the pea plant was found at different levels in vegetative and reproductive tissues. We characterized the expression levels of SAMs genes during the development or senescence of pea ovaries. Northern analysis showed that transcription of SAMs genes in parthenocarpic fruits was upregulated by auxins in the sam…
Tif1γ regulates the TGF-β1 receptor and promotes physiological aging of hematopoietic stem cells.
2014
The hematopoietic system declines with age. Myeloid-biased differentiation and increased incidence of myeloid malignancies feature aging of hematopoietic stem cells (HSCs), but the mechanisms involved remain uncertain. Here, we report that 4-mo-old mice deleted for transcription intermediary factor 1γ (Tif1γ) in HSCs developed an accelerated aging phenotype. To reinforce this result, we also show that Tif1γ is down-regulated in HSCs during aging in 20-mo-old wild-type mice. We established that Tif1γ controls TGF-β1 receptor (Tgfbr1) turnover. Compared with young HSCs, Tif1γ(-/-) and old HSCs are more sensitive to TGF-β signaling. Importantly, we identified two populations of HSCs specifical…
Physical exercise as an epigenetic modulator: Eustress, the "positive stress" as an effector of gene expression.
2012
Physical exercise positively influences epigenetic mechanisms and improves health. Several issues remain unclear concerning the links between physical exercise and epigenetics. There is growing concern about the negative influence of excessive and persistent physical exercise on health. How an individual physically adapts to the prevailing environmental conditions might influence epigenetic mechanisms and modulate gene expression. In this article, we put forward the idea that physical exercise, especially long-term repetitive strenuous exercise, positively affects health, reduces the aging process, and decreases the incidence of cancer through induced stress and epigenetic mechanisms. We pr…
Cognitive deficits in aged rats correlate with levels of l-arginine, not with nNOS expression or 3,4-DAP-evoked transmitter release in the frontopari…
2005
Aging is associated with altered neurotransmitter function in the brain. In this study, we measured release parameters for acetylcholine (ACh), norepinephrine and serotonin in the frontoparietal cortex of young and aged rats. We also determined cortical amino acid concentrations and nitric oxide (NO) synthase function. Prior to sacrifice, the rats had been tested for Morris water-maze performance. In aged, compared with young rats, we observed a reduction in both uptake of choline and acetylcholine release. Serotonin release and L-arginine concentrations (a precursor of NO) showed an aging-related increase; however, L-citrulline/L-arginine ratios were decreased in aged rats. Moreover, while…
Sponge homologue to human and yeast gene encoding the longevity assurance polypeptide: differential expression in telomerase-positive and telomerase-…
2000
Porifera show a characteristic Bauplan in spite of the fact that (almost) all cells are telomerase-positive and presumably provided with an unlimited potency for cell proliferation. Studies revealed that telomerase-positive cells can be triggered to telomerase-negative cells by dissociating them into single cells. Single cells from the demosponge Suberites domuncula, in contrast to cells present in primmorphs (a special form of cell aggregates), lack the property to proliferate and they undergo apoptosis. One gene, SDLAGL, was identified in primmorphs that showed high sequence similarity to the longevity assurance genes from other Metazoa. In single cells no transcripts of SDLAGL could be i…
Negative Regulation of β Enolase Gene Transcription in Embryonic Muscle Is Dependent upon a Zinc Finger Factor That Binds to the G-rich Box within th…
1998
We have previously identified a muscle-specific enhancer within the first intron of the human beta enolase gene. Present in this enhancer are an A/T-rich box that binds MEF-2 protein(s) and a G-rich box (AGTGGGGGAGGGGGCTGCG) that interacts with ubiquitously expressed factors. Both elements are required for tissue-specific expression of the gene in skeletal muscle cells. Here, we report the identification and characterization of a Kruppel-like zinc finger protein, termed beta enolase repressor factor 1, that binds in a sequence-specific manner to the G-rich box and functions as a repressor of the beta enolase gene transcription in transient transfection assays. Using fusion polypeptides of b…