Search results for "regulation"
showing 10 items of 4463 documents
Misguided Effort with Elusive Implications
2016
Good self-control has been linked to adaptive outcomes such as better health, cohesive personal relationships, success in the workplace and at school, and less susceptibility to crime and addictions. In contrast, self-control failure is linked to maladaptive outcomes. Understanding the mechanisms by which self-control predicts behavior may assist in promoting better regulation and outcomes. A popular approach to understanding self-control is the strength or resource depletion model. Self-control is conceptualized as a limited resource that becomes depleted after a period of exertion resulting in self-control failure. The model has typically been tested using a sequential-task experimental p…
Mboat7 down-regulation by hyper-insulinemia induces fat accumulation in hepatocytes.
2020
Background: Naturally occurring variation in Membrane-bound O-acyltransferase domain-containing 7 (MBOAT7), encoding for an enzyme involved in phosphatidylinositol acyl-chain remodelling, has been associated with fatty liver and hepatic disorders. Here, we examined the relationship between hepatic Mboat7 down-regulation and fat accumulation. Methods: Hepatic MBOAT7 expression was surveyed in 119 obese individuals and in experimental models. MBOAT7 was acutely silenced by antisense oligonucleotides in C57Bl/6 mice, and by CRISPR/Cas9 in HepG2 hepatocytes. Findings: In obese individuals, hepatic MBOAT7 mRNA decreased from normal liver to steatohepatitis, independently of diabetes, inflammatio…
The four murine peroxisomal ABC-transporter genes differ in constitutive, inducible and developmental expression.
1999
Four ATP-binding cassette (ABC) half-transporters have been identified in mammalian peroxisomes: adrenoleukodystrophy protein (ALDP), adrenoleukodystrophy-related protein (ALDRP), 70-kDa peroxisomal membrane protein (PMP70) and PMP70-related protein (P70R). Inherited defects in ALDP cause the neurodegenerative disorder X-linked adrenoleukodystrophy (X-ALD). By comparative Northern blot analyses we found each of the four murine peroxisomal ABC transporter mRNA species at maximum abundance only in a few tissues, which differed for each family member. The four genes were also regulated differentially during mouse brain development: ALDP mRNA was most abundant in embryonic brain and gradually d…
A new vicious cycle involving glutamate excitotoxicity, oxidative stress and mitochondrial dynamics
2011
Glutamate excitotoxicity leads to fragmented mitochondria in neurodegenerative diseases, mediated by nitric oxide and S-nitrosylation of dynamin-related protein 1, a mitochondrial outer membrane fission protein. Optic atrophy gene 1 (OPA1) is an inner membrane protein important for mitochondrial fusion. Autosomal dominant optic atrophy (ADOA), caused by mutations in OPA1, is a neurodegenerative disease affecting mainly retinal ganglion cells (RGCs). Here, we showed that OPA1 deficiency in an ADOA model influences N-methyl-D-aspartate (NMDA) receptor expression, which is involved in glutamate excitotoxicity and oxidative stress. Opa1enu/+mice show a slow progressive loss of RGCs, activation …
Connecting temporal identity to mitosis: the regulation of Hunchback in Drosophila neuroblast lineages.
2006
Both in vertebrates and invertebrates, neural stem cells generate different cell types at different times during development. It has been suggested that this process depends on temporal identity transitions of neural progenitors, but the underlying mechanism has not been resolved, yet. Recently, Drosophila neuroblasts (NBs) have been shown to be an excellent model system to investigate this subject. Here, changes in temporal identity are regulated by sequential and transient expression of transcription factors in the NB, such as Hunchback (Hb) and Kruppel (Kr). The temporal expression profile is maintained in the progeny. Hb is expressed first and thus defines the earliest identity in a giv…
p27Kip1participates in the regulation of endoreplication in differentiating chick retinal ganglion cells
2015
Nuclear DNA duplication in the absence of cell division (i.e. endoreplication) leads to somatic polyploidy in eukaryotic cells. In contrast to some invertebrate neurons, whose nuclei may contain up to 200,000-fold the normal haploid DNA amount (C), polyploid neurons in higher vertebrates show only 4C DNA content. To explore the mechanism that prevents extra rounds of DNA synthesis in these latter cells we focused on the chick retina, where a population of tetraploid retinal ganglion cells (RGCs) has been described. We show that differentiating chick RGCs that express the neurotrophic receptors p75 and TrkB while lacking retinoblastoma protein, a feature of tetraploid RGCs, also express p27K…
Weak D and partial D: our experience in daily activity
2011
Influence of arbuscular mycorrhizal colonisation on cadmium induced Medicago truncatula root isoflavonoid accumulation.
2012
Cadmium is a serious environmental pollution threats to the planet. Its accumulation in plants affects many cellular functions, resulting in growth and development inhibition, whose mechanisms are not fully understood. However, some fungi forming arbuscular mycorrhizal symbiosis with the majority of plant species have the capacity to buffer the deleterious effect of this heavy metal. In the present work we investigated the capacity of Rhizophagus irregularis (syn. Glomus irregularis) to alleviate cadmium stress in Medicago truncatula. In spite of a reduction in all mycorrhizal parameters, plants colonized for 21 days by R. irregularis and treated by 2 mg kg(-1) cadmium displayed less growth…
Centenarians maintain miRNA biogenesis pathway while it is impaired in octogenarians.
2016
Centenarians but not octogenarians up regulate the expression of miRNAs, as we previously reported. We have looked into miRNA biogenesis. We show that RNA POL II, DROSHA, EXPORTIN 5 and DICER, are up-regulated in centenarians compared with octogenarians. Furthermore, factors involved in the control of these miRNAs biogenesis genes are also up-regulated in centenarians. Therefore, the up-regulation of miRNA expression in centenarians can be explained in part because miRNA biogenesis pathway is depressed in octogenarians (ordinary aging) while it is maintained in centenarians (extraordinary aging).
Chromatin-associated RNA interference components contribute to transcriptional regulation in Drosophila
2009
RNA interference (RNAi) pathways have evolved as important modulators of gene expression that operate in the cytoplasm by degrading RNA target molecules through the activity of short (21-30 nucleotide) RNAs1-6. RNAi components have been reported to have a role in the nucleus, as they are involved in epigenetic regulation and heterochromatin formation(7-10). However, although RNAi-mediated post-transcriptional gene silencing is well documented, the mechanisms of RNAi-mediated transcriptional gene silencing and, in particular, the role of RNAi components in chromatin dynamics, especially in animal multicellular organisms, are elusive. Here we show that the key RNAi components Dicer 2 (DCR2) a…