Search results for "Gene expression"

Transgenic overexpression of corticotropin releasing hormone provides partial protection against neurodegeneration in an in vivo model of acute excit…

2008

Abstract Corticotropin releasing hormone (CRH) is the central modulator of the mammalian hypothalamic–pituitary–adrenal (HPA) axis. In addition, CRH affects other processes in the brain including learning, memory, and synaptic plasticity. Moreover, CRH has been shown to play a role in nerve cell survival under apoptotic conditions and to serve as an endogenous neuroprotectant in vitro . Employing mice overexpressing murine CRH in the CNS, we observed a differential response of CRH-overexpressing mice (CRH-COE hom -Nes) to acute excitotoxic stress induced by kainate compared with controls (CRH-COE con -Nes). Interestingly, CRH-overexpression reduced the duration of epileptic seizures and pre…

Arylalkylamine N-acetyltransferase gene expression in retina and pineal gland of rats under various photoperiods

2004

Abstract The present study examines how the circadian oscillators in the retina and the suprachiasmatic nucleus (SCN) respond to changes in photoperiod. ArylalkylamineN-acetyltransferase (aa-nat) gene expression studied by quantitative RT-PCR revealed that in adult Sprague–Dawley rats kept under different light–dark (LD) cycles for two weeks the temporal pattern of AA-NAT mRNA expression was identical in retina and pineal gland. In both tissues, the time span between the onset of darkness and the nocturnal rise in AA-NAT mRNA expression was 3 h under LD 20:4, 6 h under LD 12:12, and 15 h under LD 4:20. As aa-nat expression in the pineal gland is regulated by the circadian oscillator in SCN,…

Melatonin stimulates the nonamyloidogenic processing ofβAPP through the positive transcriptional regulation of ADAM10 and ADAM17

2014

Melatonin controls many physiological functions including regulation of the circadian rhythm and clearance of free radicals and neuroprotection. Importantly, melatonin levels strongly decrease as we age and patients with Alzheimer's disease (AD) display lower melatonin than age-matched controls. Several studies have reported that melatonin can reduce aggregation and toxicity of amyloid-β peptides that are produced from the β-amyloid precursor protein (βAPP). However, whether melatonin can directly regulate the βAPP-cleaving proteases ('secretases') has not been investigated so far. In this study, we establish that melatonin stimulates the α-secretase cleavage of βAPP in cultured neuronal an…

Elevated cortisol modulates hsp70 and hsp90 gene expression and protein in sea bass head kidney and isolated leukocytes

2012

In fish, interactions between Hsps and cortisol are involved in stress modulated physiological processes including innate immune responses. Cortisol exerts a role in the regulation of Hsps synthesis. Fish head kidney is a lymphomieloid and endocrine organ releasing cortisol, and it is the central organ for immune-endocrine interactions. In sea bass, cortisol intraperitoneal injection and in vitro treatment of head kidney cells show that inducible Hsp70 and Hsp90 are modulated by this hormone. However, an inverse relationship between mRNA expression (real-time PCR) and Hsp70 and Hsp90 protein levels (densitometric band analysis) was found. Time-course assays indicate a cortisol-mediated regu…

Guidelines for biomarker discovery in endometrium: correcting for menstrual cycle bias reveals new genes associated with uterine disorders

2021

Abstract Transcriptomic approaches are increasingly used in reproductive medicine to identify candidate endometrial biomarkers. However, it is known that endometrial progression in the molecular biology of the menstrual cycle is a main factor that could affect the discovery of disorder-related genes. Therefore, the aim of this study was to systematically review current practices for considering the menstrual cycle effect and to demonstrate its bias in the identification of potential biomarkers. From the 35 studies meeting the criteria, 31.43% did not register the menstrual cycle phase. We analysed the menstrual cycle effect in 11 papers (including 12 studies) from Gene Expression Omnibus: t…

Does Arsenic Contamination Affect DNA Methylation Patterns in a Wild Bird Population? : An Experimental Approach

2021

Pollutants, such as toxic metals, negatively influence organismal health and performance, even leading to population collapses. Studies in model organisms have shown that epigenetic marks, such as DNA methylation, can be modulated by various environmental factors, including pollutants, influencing gene expression, and various organismal traits. Yet experimental data on the effects of pollution on DNA methylation from wild animal populations are largely lacking. We here experimentally investigated for the first time the effects of early-life exposure to environmentally relevant levels of a key pollutant, arsenic (As), on genome-wide DNA methylation in a wild bird population. We experimentall…

Towards powerful old age : association between hormone replacement therapy and skeletal muscle

2010

F-type lectin from the sea bass (Dicentrarchus labrax): purification, cDNA cloning, tissue expression and localization, and opsonic activity.

2009

Recently described biochemical and structural aspects of fucose-binding lectins from the European eel (Anguilla anguilla) and striped bass (Morone saxatilis) led to the identification of a novel lectin family ("F-type" lectins) characterized by a unique sequence motif and a characteristic structural fold. The F-type fold is shared not only with other members of this lectin family, but also with apparently unrelated proteins ranging from prokaryotes to vertebrates. Here we describe the purification, biochemical and molecular properties, and the opsonic activity of an F-type lectin (DlFBL) isolated from sea bass (Dicentrarchus labrax) serum. DlFBL exhibits two tandemly arranged carbohydrate-r…

Role of dioxygenase α-DOX2 and SA in basal response and in hexanoic acid-induced resistance of tomato (Solanum lycopersicum) plants against Botrytis …

2015

Resistance of tomato (Solanum Lycopersicum) to the fungal pathogen Botrytis cinerea requires complex interplay between hormonal signalling. In this study, we explored the involvement of new oxylipins in the tomato basal and induced response to this necrotroph through the functional analysis of the tomato α-dioxygenase2 (α-DOX2)-deficient mutant divaricata. We also investigated the role of SA in the defence response against this necrotrophic fungus using SA-deficient tomato nahG plants. The plants lacking dioxigenase α-DOX2, which catalyses oxylipins production from fatty acids, were more susceptible to Botrytis, and hexanoic acid-induced resistance (Hx-IR) was impaired; hence α-DOX2 is requ…

Involvement of an Alkane Hydroxylase System of Gordonia sp. Strain SoCg in Degradation of Solid n-Alkanes▿

2010

ABSTRACT Enzymes involved in oxidation of long-chain n -alkanes are still not well known, especially those in Gram-positive bacteria. This work describes the alkane degradation system of the n -alkane degrader actinobacterium Gordonia sp. strain SoCg, which is able to grow on n -alkanes from dodecane (C 12 ) to hexatriacontane (C 36 ) as the sole C source. SoCg harbors in its chromosome a single alk locus carrying six open reading frames (ORFs), which shows 78 to 79% identity with the alkane hydroxylase (AH)-encoding systems of other alkane-degrading actinobacteria. Quantitative reverse transcription-PCR showed that the genes encoding AlkB (alkane 1-monooxygenase), RubA3 (rubredoxin), RubA4…