Search results for "RECEPTORS"
showing 10 items of 3254 documents
Selenoproteins, cholesterol-lowering drugs, and the consequences: revisiting of the mevalonate pathway.
2004
3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and peroxisome proliferator-activated receptor alpha activators (fibrates) are the backbone of pharmacologic hypercholesterolemia and dyslipidemia treatment. Many of their clinical effects, however, are still enigmatic. This article describes how a side road of the mevalonate pathway, characterized in recent years, can rationalize a major fraction of these unexplained observations. This side road is the enzymatic isopentenylation of selenocysteine-tRNA([Ser]Sec) (Sec-tRNA), the singular tRNA to decode the unusual amino acid selenocysteine. The functionally indispensable isopentenylation of Sec-tRNA requires a unique interm…
Genetic-dependency of peroxisomal cell functions - emerging aspects
2003
This paper reviews aspects concerning the genetic regulation of the expression of the well studied peroxisomal genes including those of fatty acid beta-oxidation enzymes; acyl-CoA oxidase, multifunctional enzyme and thiolase from different tissues and species. An important statement is PPARalpha, which is now long known to be in rodents the key nuclear receptor orchestrating liver peroxisome proliferation and enhanced peroxisomal beta-oxidation, does not appear to control so strongly in man the expression of genes involved in peroxisomal fatty acid beta-oxidation related enzymes. In this respect, the present review strengthens among others the emerging concept that, in the humans, the main …
Synthetic studies on neoclerodane diterpenes from Salvia splendens: oxidative modifications of ring A.
2011
Salvinorin A (1), a neoclerodane diterpene from the hallucinogenic mint Salvia divinorum, is the only known naturally occurring non-nitrogenous and specific κ-opioid agonist. Some oxidative modifications of the A ring in the congeners of 1 isolated from Salvia splendens salviarin, splenolide B, splendidin and in the non-natural 8-epi-salviarin gave new derivatives, some of which were tested as agonists at opioid receptors. However, none of these compounds were active. The presence of the C-18, C-19 lactone could be at the origin of the observed lack of binding affinity.
Cigarette smoke increases TLR4 and modifies LPS mediated responses in airway epithelial cells.
2008
Airway epithelium is emerging as a regulator of innate immune responses to a variety of insults including cigarette smoke. The main goal of this study was to explore the effects of cigarette smoke extracts (CSE) on Tolllike receptor (TLR) expression and activation in a human bronchial epithelial cell line (16-HBE). The CSE increased the expression of TLR4 and the lipopolysaccharide (LPS) binding, the nuclear factor-jB (NF-jB) activation, the release of interleukin-8 (IL-8) and the chemotactic activity toward neutrophils. It did not induce TLR2 expression or extracellular signal-regulated signal kinase 1/2 (ERK1/2) activation. The LPS increased the expression of TLR4 and induced both NF-jB a…
The hedgehog receptor patched is involved in cholesterol transport.
2011
International audience; BACKGROUND: Sonic hedgehog (Shh) signaling plays a crucial role in growth and patterning during embryonic development, and also in stem cell maintenance and tissue regeneration in adults. Aberrant Shh pathway activation is involved in the development of many tumors, and one of the most affected Shh signaling steps found in these tumors is the regulation of the signaling receptor Smoothened by the Shh receptor Patched. In the present work, we investigated Patched activity and the mechanism by which Patched inhibits Smoothened. METHODOLOGY/PRINCIPAL FINDINGS: Using the well-known Shh-responding cell line of mouse fibroblasts NIH 3T3, we first observed that enhancement …
Sigma 1 receptora gēna izslēgšanas ietekme uz adipozo audu stromas šūnu diferenciāciju
2020
Cilmes šūnu iegūšanas avoti, diferenciācijas potenciāli un kas to ietekmē, un to izmantošana terapeitiskos nolūkos ir liels diskusiju un izpētes objekts. Viens no variantiem ir no taukaudiem iegūtās stromas šūnas, kuras ir multipotentas cilmes šūnas, kurām ir pierādīta spēja diferencēties pa osteogēno līniju, kā arī adipogēnu, hondrogēnu un miogēnu šūnu tipiem un citiem. Tiek apskatīti faktori, kas var ietekmēt to diferenciāciju. Šī darba mērķis bija gūt labāku ieskatu uz Sigma 1 receptora gēna izslēgšanas jeb inaktivēšanas ietekmi uz adipozo audu stromas šūnu diferenciāciju. Maģistra darba uzdevumi bija papildināt iemaņas darbā šūnu kultūru laboratorijā un apskatīt pieejamo literatūru par …
Integrin α2β1 Mediates Isoform-Specific Activation of p38 and Upregulation of Collagen Gene Transcription by a Mechanism Involving the α2 Cytoplasmic…
1999
Two collagen receptors, integrins alpha1beta1 and alpha2beta1, can regulate distinct functions in cells. Ligation of alpha1beta1, unlike alpha2beta1, has been shown to result in recruitment of Shc and activation of the Ras/ERK pathway. To identify the downstream signaling molecules activated by alpha2beta1 integrin, we have overexpressed wild-type alpha2, or chimeric alpha2 subunit with alpha1 integrin cytoplasmic domain in human osteosarcoma cells (Saos-2) lacking endogenous alpha2beta1. The chimeric alpha2/alpha1 chain formed a functional heterodimer with beta1. In contrast to alpha2/alpha1 chimera, forced expression of alpha2 integrin resulted in upregulation of alpha1 (I) collagen gene …
Convergent Loss of Chemoreceptors across Independent Origins of Slave-Making in Ants
2022
The evolution of an obligate parasitic lifestyle often leads to the reduction of morphological and physiological traits, which may be accompanied by loss of genes and functions. Slave-maker ants are social parasites that exploit the work force of closely related ant species for social behaviours such as brood care and foraging. Recent divergence between these social parasites and their hosts enables comparative studies of gene family evolution. We sequenced the genomes of eight ant species, representing three independent origins of ant slavery. During the evolution of eusociality, chemoreceptor genes multiplied due to the importance of chemical communication in societies. We investigated ev…
The Epigenetics of the Endocannabinoid System
2020
The endocannabinoid system (ES) is a cell-signalling system widely distributed in biological tissues that includes endogenous ligands, receptors, and biosynthetic and hydrolysing machineries. The impairment of the ES has been associated to several pathological conditions like behavioural, neurological, or metabolic disorders and infertility, suggesting that the modulation of this system may be critical for the maintenance of health status and disease treatment. Lifestyle and environmental factors can exert long-term effects on gene expression without any change in the nucleotide sequence of DNA, affecting health maintenance and influencing both disease load and resistance. This potentially …
Receptor for advanced glycation end products is subjected to protein ectodomain shedding by metalloproteinases.
2008
The receptor for advanced glycation end products (RAGE) is a 55-kDa type I membrane glycoprotein of the immunoglobulin superfamily. Ligand-induced up-regulation of RAGE is involved in various pathophysiological processes, including late diabetic complications and Alzheimer disease. Application of recombinant soluble RAGE has been shown to block RAGE-mediated pathophysiological conditions. After expression of full-length RAGE in HEK cells we identified a 48-kDa soluble RAGE form (sRAGE) in the culture medium. This variant of RAGE is smaller than a 51-kDa soluble version derived from alternative splicing. The release of sRAGE can be induced by the phorbol ester PMA and the calcium ionophore c…