Search results for " Regulation"
showing 10 items of 3187 documents
Serine- and Threonine/Valine-Dependent Activation of PDK and Tor Orthologs Converge on Sch9 to Promote Aging
2014
Dietary restriction extends longevity in organisms ranging from bacteria to mice and protects primates from a variety of diseases, but the contribution of each dietary component to aging is poorly understood. Here we demonstrate that glucose and specific amino acids promote stress sensitization and aging through the differential activation of the Ras/cAMP/PKA, PKH1/2 and Tor/S6K pathways. Whereas glucose sensitized cells through a Ras-dependent mechanism, threonine and valine promoted cellular sensitization and aging primarily by activating the Tor/S6K pathway and serine promoted sensitization via PDK1 orthologs Pkh1/2. Serine, threonine and valine activated a signaling network in which Sch…
Trichinella spiralisThymidylate Synthase: Developmental Pattern, Isolation, Molecular Properties, and Inhibition by Substrate and Cofactor Analogues
1996
Abstract Thymidylate synthase specific activity was found to remain at a constant level in crude extracts from muscle larvae, isolated (1-15 months after infection) by pepsin-HCl digestion, as well as from adult worms ofTrichinella spiralis.The enzyme was purified and its molecular (monomer mol. wt 35 kD) and kinetic (sequential mechanism with the Kmvalues 3.1 and 19 μM for dUMP and N5,10-methylenetetrahydrofolate, respectively) properties determined. 5-Fluoro-dUMP was a competitive, slow-binding inhibitor of the parasite enzyme. N5,10-methylenetetrahydrofolate analogues 10-propargyl-5,8-dideazafolate (CB3717), ZD1694, BW1843U89, and AG337 were weaker inhibitors of the parasite than regener…
A two miRNA classifier differentiates follicular thyroid carcinomas from follicular thyroid adenomas.
2015
The inherent diagnostic limitations of thyroid fine needle aspiration (FNA), especially in the "indeterminate" category, can be partially overcome by molecular analyses. We aimed at the identification of miRNAs that could be used to improve the discrimination of indeterminate FNAs. miRNA expression profiling was performed for 17 follicular carcinomas (FTCs) and 8 follicular adenomas (FAs). The microarray results underwent cross-comparison using three additional microarray data sets. Candidate miRNAs were validated by qPCR in an independent set of 32 FTCs and 46 FAs. Sixty-eight differentially expressed miRNAs were identified. Thirteen miRNAs could be confirmed by cross comparison. A two-miR…
Cultured Ito cells of rat liver express the alpha 2-macroglobulin gene.
1987
Ito cells were isolated from rat liver and kept in culture for up to 13 days. The capability of the Ito cells to synthesize a2-macroglobulin was analyzed at different times after isolation and by pulse-chase experiments. Newly synthesized a2-macroglobulin was determined by immunoprecipitation followed by sodium dodecyl sulfate/ polyacrylamide gel electrophoresis and fluorography. a2-Macroglobulin synthesis was hardly detectable in Ito cells and their media 3 days after plating. However, 5 - 11 days after the isolation of the cells, increasing amounts of a2-macroglobulin were synthesized. The results of pulse-chase experiments performed on day 7 showed that radioactively labeled a2-macroglob…
Cadmium regulation of apoptotic and stress response genes in tumoral and immortalized epithelial cells of the human breast
2008
Cadmium (Cd) is a widely-disseminated metal which can be imported and accumulated in living cells thereby drastically interfering with their biological mechanisms. Increasing interest has been recently focused on the elucidation of the cellular and molecular aspects of Cd-dependent regulation of gene expression and signal transduction pathways in different model system. Concerning breast cancer, very limited studies have been produced so far on the role played by Cd on estrogen receptor-negative human breast cancer cells, that are expected to be insensitive to the already-proven metallo-estrogenic effect exerted by Cd on the estrogen receptor-positive cell counterparts. Here, we have examin…
Let-7d miRNA Shows Both Antioncogenic and Oncogenic Functions in Osteosarcoma-Derived 3AB-OS Cancer Stem Cells
2015
Osteosarcoma (OS), an aggressive highly invasive and metastatic bone-malignancy, shows therapy resistance and recurrence, two features that likely depend on cancer stem cells (CSCs), which hold both self-renewing and malignant potential. So, effective anticancer therapies against OS should specifically target and destroy CSCs. We previously found that the let-7d microRNA was downregulated in the 3AB-OS-CSCs, derived from the human OS-MG63 cells. Here, we aimed to assess whether let-7d modulation affected tumorigenic and stemness properties of these OS-CSCs. We found that let-7d-overexpression reduced cell proliferation by decreasing CCND2 and E2F2 cell-cycle-activators and increasing p21 an…
Profilin1 regulates sternum development and endochondral bone formation.
2012
Bone development is a dynamic process that requires cell motility and morphological adaptation under the control of actin cytoskeleton. This actin cytoskeleton system is regulated by critical modulators including actin-binding proteins. Among them, profilin1 (Pfn1) is a key player to control actin fiber structure, and it is involved in a number of cellular activities such as migration. During the early phase of body development, skeletal stem cells and osteoblastic progenitor cells migrate to form initial rudiments for future skeletons. During this migration, these cells extend their process based on actin cytoskeletal rearrangement to locate themselves in an appropriate location within mic…
Metazoan Circadian Rhythm: Toward an Understanding of a Light-Based Zeitgeber in Sponges
2013
In all eukaryotes, the 24-h periodicity in the environment contributed to the evolution of the molecular circadian clock. We studied some elements of a postulated circadian clock circuit in the lowest metazoans, the siliceous sponges. First, we identified in the demosponge Suberites domuncula the enzyme luciferase that generates photons. Then (most likely), the photons generated by luciferase are transmitted via the biosilica glass skeleton of the sponges and are finally harvested by cryptochrome in the same individual; hence, cryptochrome is acting as a photosensor. This information-transduction system, generation of light (luciferase), photon transmission (through the siliceous spicules),…
Spatial learning and expression patterns of PP1 mRNA in mouse hippocampus.
2009
<i>Background:</i> Synaptic plasticity is believed to be the major cellular basis for learning and memory. Protein phosphorylation is a key process involved in changes in the efficacy of neurotransmission. In long-term changes synaptic plasticity is followed by structural plasticity and protein de novo synthesis. Such mechanisms are believed to build the basis of hippocampal learning and memory investigated in the Morris water maze (MWM) task. To examine the role of dephosphorylation during that model for spatial learning, we analyzed protein phosphatase 1 (PP1) expression in the hippocampus of mice at various stages of the task and in two groups with different learning abilitie…
Prunella vulgaris L. Upregulates eNOS Expression in Human Endothelial Cells
2010
The purported effects of "circulation-improving" herbs used in traditional Chinese medicine (TCM) show striking similarities with the vascular actions of nitric oxide (NO) produced by the endothelial NO synthase (eNOS). We have previously reported that Salviae miltiorrhizae radix and Zizyphi spinosae semen upregulate eNOS expression. In the present study, we studied the effect on eNOS gene expression of 15 Chinese herbs with potential effects on the vasculature, and identified Prunella vulgaris L. (PVL) (flowering spike) as a potent eNOS-upregulating agent. In EA.hy 926 cells, a cell line derived from human umbilical vein endothelial cells (HUVEC), an aqueous extract of PVL increased eNOS …