Essential Molecules (essential + molecule)

Distribution by Scientific Domains


Selected Abstracts


Proteome analysis of adipocyte lipid rafts reveals that gC1qR plays essential roles in adipogenesis and insulin signal transduction

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 9 2009
Ki-Bum Kim
Abstract Since insulin receptors and their downstream signaling molecules are organized in lipid rafts, proteomic analysis of adipocyte lipid rafts may provide new insights into the function of lipid rafts in adipogenesis and insulin signaling. To search for proteins involved in adipocyte differentiation and insulin signaling, we analyzed detergent-resistant lipid raft proteins from 3T3-L1 preadipocytes and adipocytes by 2-DE. Eleven raft proteins were identified from adipocytes. One of the adipocyte-specific proteins was globular C1q receptor (gC1qR), an acidic 32,kDa protein known as the receptor for the globular domain of complement C1q. The targeting of gC1qR into lipid rafts was significantly increased during adipogenesis, as determined by immunoblotting and immunofluorescence. Since the silencing of gC1qR by small RNA interference abolished adipogenesis and blocked insulin-induced activation of insulin receptor, insulin receptor substrate-1 (IRS-1), Akt, and Erk1/2, we can conclude that gC1qR is an essential molecule involved in adipogenesis and insulin signaling. [source]


C. elegans knockouts in ubiquinone biosynthesis genes result in different phenotypes during larval development

BIOFACTORS, Issue 1-4 2005
ÁNgela Gavilán
Abstract Ubiquinone is an essential molecule in aerobic organisms to achieve both, ATP synthesis and antioxidant defence. Mutants in genes responsible of ubiquinone biosynthesis lead to non-respiring petite yeast. In C. elegans, coq-7/clk-1 but not coq-3 mutants live longer than wild type showing a ,slowed' phenotype. In this paper we demonstrate that absence in ubiquinone in coq-1, coq-2 or coq-8 mutants lead to larval development arrest, slowed pharyngeal pumping, eventual paralysis and cell death. All these features emerge during larval development, whereas embryo development appeared similar to that of wild type individuals. Dietary coenzyme Q did not restore any of the alterations found in these coq mutants. These phenomena suggest that coenzyme Q mutants unable to synthesize this molecule develop a deleterious phenotype leading to lethality. On the contrary, phenotype of C. elegans coq-7/clk-1 mutants may be a unique phenotype than can not generalize to mutants in ubiquinone biosynthesis. This particular phenotype may not be based on the absence of endogenous coenzyme Q, but to the simultaneous presence of dietary coenzyme Q and the its biosynthesis intermediate demethoxy-coenzyme Q. [source]


Identification of ventricular-side-enriched molecules regulated in a stage-dependent manner during cerebral cortical development

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2006
Itsuki Ajioka
Abstract Radial glial cells are the main component of the embryonic cortical ventricular zone (VZ), producing deep-layer excitatory neurons in the early stage and upper-layer excitatory neurons in the late stage of development. Previous studies have suggested that the laminar fate of deep-layer neurons might be determined by early-stage-specific secretory or transmembrane molecules (S/TMs) in the VZ. However, the different properties required to produce the different types of neurons in early-stage and late-stage VZ cells are largely unknown. Herein, we investigated the stage-dependent transcriptional profiles of the ventricular side of the mouse cortex, which was manually dissected at embryonic day (E)12, E14 and E16, and identified 3985 ,VZ-enriched' genes, regulated stage-dependently, by GeneChip analysis. These molecules were classified into nine types based on stage-dependent regulation patterns. Prediction programs for the S/TMs revealed 659 ,VZ-enriched' S/TMs. In situ hybridization and real-time PCR analysis for several of these molecules showed results consistent with the statistical analysis of the GeneChip experiments. Moreover, we identified 17 cell cycle-related early-stage and ,VZ-enriched' molecules. These molecules included not only those involved in cell cycle progression, but also essential molecules for DNA double-strand break repair, such as Rad51 and Rpa1. These results suggest that the early stage-VZ cells, which produce both deep- and upper-layer neurons, and the late-stage VZ cells, which produce only upper-layer neurons, are intrinsically different. The gene lists presented here will be useful for the investigation of stage-dependent changes in VZ cells and their regulatory mechanisms in the developing cortex. [source]


Effect of cigarette smoke extract on the polymorphonuclear leukocytes chemiluminescence: influence of a filter containing glutathione

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 2 2005
B. Zappacosta
Abstract Cigarette smoking is known to be a risk factor for several chronic and neoplastic diseases. Many compounds formed by cigarette burning, ranging from particulate materials to water solutes and gaseous extracts, are considered to be noxious agents, and many biochemical and molecular mechanisms have been proposed for the toxic effects of cigarette smoke. The oral cavity and the upper respiratory tract represent the first contact areas for smoke compounds; even a single cigarette can produce marked effects on some components of the oral cavity, either chemical compounds, such as glutathione and enzymes, or cellular elements, such as polymorphonuclear leukocytes. Several studies suggest a protective role of glutathione against the noxious effects of tobacco smoke; the sulphydril groups of glutathione, in fact, could react with some smoke products, such as unsaturated aldehydes, leading to the formation of harmless intermediate compounds and simultaneously preventing the inactivation of metabolically essential molecules, such as some enzymes. In this paper we analyse the effect of a filter containing glutathione on the respiratory burst of polymorphonuclear leukocytes exposed to aqueous extract of cigarette smoke, measuring their chemiluminescence activity. The results of this paper indicate that the GSH--containing filter has a likely protective effect against the inhibition of cigarette smoke extract on polymorphonuclear leukocyte activity. Copyright © 2005 John Wiley & Sons, Ltd. [source]


REVIEW ARTICLE: Inflammation and Implantation

AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2010
Nava Dekel
Approximately half of all human embryo implantations result in failed pregnancy. Multiple factors may contribute to this failure, including genetic or metabolic abnormalities of the embryo. However, many of these spontaneous early abortion cases are attributed to poor uterine receptivity. Furthermore, although many fertility disorders have been overcome by a variety of assisted reproductive techniques, implantation remains the rate-limiting step for the success of the in vitro fertilization (IVF) treatments. It has been demonstrated that endometrial biopsies performed either during the spontaneous, preceding cycle, or during the IVF cycle itself, significantly improve the rate of implantation, clinical pregnancies and live births. These observations suggest that mechanical injury of the endometrium may enhance uterine receptivity by provoking the immune system to generate an inflammatory reaction. In strong support of this idea, we recently found that dendritic cells (DCs), an important cellular component of the innate immune system, play a critical role in successful implantation in a mouse model. In this review, we discuss the hypothesis that the injury-derived inflammation in the biopsy-treated patients generates a focus for uterine DCs accumulation that, in turn, enhances the endometrial expression of essential molecules, which facilitate the interaction between the embryo and the uterine epithelium. [source]