RESUMO
Organisms have evolved a complex system, called the DNA damage response (DDR), which maintains genome integrity. The DDR is responsible for identifying and repairing a variety of lesions and alterations in DNA. DDR proteins coordinate DNA damage detection, cell cycle arrest, and repair, with many of these events regulated by protein phosphorylation. In the human proteome, 23 proteins contain the BRCT (BRCA1 C-Terminus domain) domain, a modular signaling domain that can bind phosphopeptides and mediate protein-protein interactions. BRCTs can be found as functional single units, tandem (tBRCT), triplet (tpBRCT), and quartet. Here we examine the evolution of the tpBRCT architecture present in TOPBP1 (DNA topoisomerase II binding protein 1) and ECT2 (epithelial cell transforming 2), and their respective interaction partners RAD9 (Cell cycle checkpoint control protein RAD9) and CYK-4 (Rac GTPase-activating protein 1), with a focus on the conservation of the phosphopeptide-binding residues. The pair TOPBP1-RAD9 arose with the Eukaryotes and ECT2-CYK-4 with the Eumetazoans. Triplet structural and functional characteristics were conserved in almost all organisms. The first unit of the triplet (BRCT0) is different from the other two BRCTs but conserved between orthologs for both TOPBP1 and ECT2. BRCT domain evolution simulations suggest a trend to retain the singlet or towards two or three BRCT copies per protein consistent with functional tBRCT and tpBRCT architectures. Our results shed light on the emergence of the function and architecture of multiple BRCT domain organizations and provide information about the evolution of the BRCT triplet. Knowledge of BRCT domain evolution can improve the understanding of DNA damage response mechanisms and signal transduction in DDR.
Assuntos
Proteína BRCA1 , Proteínas de Ciclo Celular , Humanos , Proteína BRCA1/metabolismo , Domínios Proteicos , Proteínas de Ciclo Celular/metabolismo , Dano ao DNA , Transdução de Sinais , Fosforilação , Ligação ProteicaRESUMO
The effect of fine wheat bran (FWB) as a methyl donor source on performance, metabolism, body composition and blood traits of growing broilers was studied. Three hundred and twenty broilers from eight to 28 d of age, distributed in a randomized block design, with five treatments and eight replicates of eight animals each were used. The experimental diets were: NC, formulated with 72% of the Met+Cys requirement; Met, formulated with 85% of the Met+Cys equivalents by DL-methionine addition; Bet, formulated with 85% of the Met+Cys equivalents by anhydrous betaine addition; Fwb-, formulated with 72% of the Met+Cys requirement and 20% FWB; and Fwb+, formulated with 85% of the Met+Cys requirement and 20% FWB. Feed intake was reduced (p 0.05) by FWB inclusion but the feed conversion ratio was the same (p>0.05) between the positive control diets. Supplementation of DL-methionine and anhydrous betaine showed the same (p>0.05) metabolizability of nutrients. Treatments with higher DL-methionine levels (Met and Fwb+) promoted more weight of feathers (p 0.05). Animals fed with FWB showed the lowest (p 0.05) body gains. In conclusion, FWB inclusion did not promote methyl radicals supply.
Assuntos
Animais , Aves/fisiologia , Aves/metabolismo , Betaína/administração & dosagem , Betaína/síntese química , Triticum/químicaRESUMO
The effect of fine wheat bran (FWB) as a methyl donor source on performance, metabolism, body composition and blood traits of growing broilers was studied. Three hundred and twenty broilers from eight to 28 d of age, distributed in a randomized block design, with five treatments and eight replicates of eight animals each were used. The experimental diets were: NC, formulated with 72% of the Met+Cys requirement; Met, formulated with 85% of the Met+Cys equivalents by DL-methionine addition; Bet, formulated with 85% of the Met+Cys equivalents by anhydrous betaine addition; Fwb-, formulated with 72% of the Met+Cys requirement and 20% FWB; and Fwb+, formulated with 85% of the Met+Cys requirement and 20% FWB. Feed intake was reduced (p 0.05) by FWB inclusion but the feed conversion ratio was the same (p>0.05) between the positive control diets. Supplementation of DL-methionine and anhydrous betaine showed the same (p>0.05) metabolizability of nutrients. Treatments with higher DL-methionine levels (Met and Fwb+) promoted more weight of feathers (p 0.05). Animals fed with FWB showed the lowest (p 0.05) body gains. In conclusion, FWB inclusion did not promote methyl radicals supply.(AU)
Assuntos
Animais , Aves/metabolismo , Aves/fisiologia , Triticum/química , Betaína/administração & dosagem , Betaína/síntese químicaRESUMO
Life cycle assessment (LCA) has been used in many studies to evaluate the effect of feeding strategy on the environmental impact of pig production. However, because most studies have been conducted in European conditions, the question of possible interactions with the context of production is still under debate. The objective of this study was to evaluate these effects in 2 contrasted geographic contexts of production, South America (Brazil) and Europe (France). The LCA considered the process of pig fattening, including production and transport of feed ingredients and feed, raising of fattening pigs, and manure storage, transport, and spreading. Impacts were calculated at the farm gate, and the functional unit considered was 1 kg of BW gain over the fattening period. The performances of pigs were simulated for each scenario using the InraPorc population model (2,000 pigs per scenario considering between-animal variability). The LCA calculations were performed for each pig according to its own performance and excretion, and the results were subjected to variance analysis. The results indicate that for some impacts there are clear interactions between the effects of the feeding program, the origin of soybean, and the location of production. For climate change, interest in phase feeding and incorporation of crystalline AA (CAA) is limited and even counterproductive in Brazil with soybeans from the South (without deforestation), whereas they appear to be efficient strategies with soybeans from the Center West (with deforestation), especially in France. Rather similar effects, as those for climate change, were observed for cumulative energy demand. Conversely, potential eutrophication and acidification impacts were reduced by phase feeding and CAA addition in a rather similar way in all situations. Individual daily feeding, the only strategy that took into account between-animal variability, was the most effective approach for reducing the life cycle impact of pig fattening in all situations, whereas the potential of phase feeding programs and CAA was dependent on soybean origin and the geographical context of pig production, in contrast with previous results.
Assuntos
Criação de Animais Domésticos/métodos , Estágios do Ciclo de Vida , Suínos/fisiologia , Animais , Brasil , Mudança Climática , Conservação dos Recursos Naturais , Meio Ambiente , Eutrofização , Feminino , França , Masculino , Esterco , Modelos Teóricos , Glycine max , Suínos/crescimento & desenvolvimentoRESUMO
GR primary cells cultures were isolated from hepatic granulomas induced in C3H mice livers by Schistosoma mansoni infection; the GRX continuous cell line was derived from GR cells after long-term culture and a progressive drift towards a rapidly proliferating cell population. These cells were analyzed and compared in terms of their clonal heterogeneity. Clones were classified on the basis of cell substrate, cell-cell adhesion (growth morphology of the clone) and fat droplet accumulation. GR cells were composed of two slow-growing clone types, while GRX cells gave rise to clones with several phenotypes, including the two found in the GR cells. The overall proportion of different clones in the GRX cell population was stable in long-term cultures, as well as after recloning of the highly proliferating, but not the slowly proliferating, clones. We propose that the slow-growing clones are maintained in the overall population by continuous contribution of new slow-growing cells from the rapidly growing ones. The slow-growing clones may represent the basal population of liver connective tissue cells that can be mobilized into injured tissues and that are involved in tissue repair. The highly proliferating clones with a broad capacity of phenotype expression that arise after long-term growth stimulation of the local cell population may represent the hypertrophic connective tissue cells, such as those observed in progressive fibrotic reactions associated with chronic liver tissue inflammation.
Assuntos
Fígado/patologia , Animais , Linhagem Celular , Células Clonais , Tecido Conjuntivo/patologia , Fibroblastos/patologia , Heterogeneidade Genética , Granuloma/patologia , Hepatopatias Parasitárias/patologia , Camundongos , Camundongos Endogâmicos C3H , Esquistossomose mansoni/patologiaRESUMO
GR primary cells cultures were isolated from hepatic granulomas induced in C3H mice livers by Schistosoma mansoni infection; the GRX continuous cell line was derived from GR cells after long-term culture and a progressive drift towards a rapidly proliferating cell population. These cells were analyzed and compared in terms of their clonal heterogeneity. Clones were classified on the basis of cell substrate, cell-cell adhesion (growth morphology of the clone) and fat droplet accumultation. GR cells were composed of two slow-growing clone types, while GRX cells grave rise to clones with several phenotypes, including the two found in the GR cells. The overall proportion of different clones in the GRX cell population was stable in long-term cultures, as well as after recloning of the highly proliferating, but not the slowly proliferating, clones. We propose that the slow-growing clones are maintained in the overall population by continuous contribution of new slow-growing cells from the rapidly growing ones. The slow-growing clones may represent the basal population of liver connective tissue cells that can be mobilized into injured tissues and that are involved in tissue repair. The highth proliferating clones with a broad capacity of phenotype expression that arise after long-term growth simulation of the local cell population may represent the hypertrophic connective tissue cells, such as those observed in progressive fibrotic reactions associated with chronic liver tissue inflammation
Assuntos
Animais , Camundongos , Fígado/patologia , Linhagem Celular , Células Clonais , Tecido Conjuntivo/patologia , Fibroblastos/patologia , Heterogeneidade Genética , Granuloma/patologia , Hepatopatias Parasitárias/patologia , Esquistossomose mansoni/patologiaRESUMO
Liver connective tissue cells (LCTC) isolated from patients with fibrotic livers have morphological and biochemical characteristics of myofibroblasts. We have examined the proliferation of LCTC derived from normal livers and from livers with fibrosis of different etiologies, as well as proliferation of skin fibroblasts. We have compared proliferation rates in the presence of fresh human serum and heat-inactivated serum. While skin fibroblast and LCTC from normal liver showed no difference, proliferation of LCTC from fibrotic livers was markedly decreased in the presence of heat-inactivated serum. We demonstrate that the native complement component C1 is a factor involved in the induction of DNA synthesis and proliferation of LCTC isolated from fibrotic livers. We propose that native C1, acting probably in cooperation with other growth factors, is involved in the expansion of connective tissue cells during the development of liver fibrosis.
Assuntos
Proteínas do Sistema Complemento/fisiologia , Células do Tecido Conjuntivo , DNA/biossíntese , Fígado/citologia , Sangue , Divisão Celular , Tecido Conjuntivo/metabolismo , Humanos , Fígado/metabolismo , Cirrose Hepática/metabolismo , Cirrose Hepática/patologiaRESUMO
Hepatic injury elicits an excessive deposition of extracellular matrix probably due to a loss of control mechanisms in mesenchymal cells in fibrotic lesions, or a local activity of growth factors. To study collagen synthesis in an in vitro model of fibrotic lesions, we isolated liver connective tissue cells (LCTC) from murine schistosomal granulomas in C3H/HeN mice. Collagen was quantified in culture supernatants using a sirius red dye assay. LCTC and skin fibroblasts (SF) secreted similar amounts of collagen per cell and secretion was inversely proportional to the cell density. Cells cultured at low density (10,000 cells/cm2) secreted two- to three-times more collagen per cell when compared to cells grown in high-density cultures (60,000 cells/cm2). Collagen secretion was stimulated by transforming growth factor-beta (TGF-beta) in both cell lines, but the response of LCTC was detected from 1 ng/ml on, while SF responded only to higher concentrations (2.5 and 5 ng/ml). These data do not support the hypothesis that cells from fibrotic livers have lost the normal control mechanisms and suggest that their control is disturbed locally by the presence of peptide growth factors during the development of fibrosis.
Assuntos
Colágeno/biossíntese , Tecido Conjuntivo/metabolismo , Granuloma/metabolismo , Fígado/metabolismo , Esquistossomose/metabolismo , Animais , Tecido Conjuntivo/patologia , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Granuloma/patologia , Fígado/patologia , Hepatopatias Parasitárias/metabolismo , Hepatopatias Parasitárias/patologia , Camundongos , Camundongos Endogâmicos C3H , Esquistossomose/patologia , Fator de Crescimento Transformador beta/farmacologiaRESUMO
Hepatic injury elicits an excessive deposition of extracellular matrix probably due to a loss of control mechanisms in mesenchymal cells in fibrotic lesions, or a local activity of growth factors. To study collagen synthesis in an in vitro model of fibrotic lesions, we isolated liver connective tissue cells (LCTC) from murine schistosomal granulomas in C3H/HeN mice. Collagen was quantified in culture supernatants using a sirius red dye assay. LCTC and skin fibroblasts (SF) secreted similar amounts of collagen per cell and secretion was inversely proportional to the cell density. Cells cultured at low density (10,000 cells/cm2) secreted two- to three-times more collagen per cell when compared to cells grown in high-density cultures (60,000 cells/cm2). Collagen secretion was stimulated by transforming growth factor-beta (TGF-beta) in both cell lines, but the response of LCTC was detected from 1 ng/ml on, while SF responded only to higher concentrations (2.5 and 5 ng/ml). These data do not support the hypothesis that cells from fibrotic livers have lost the normal control mechanisms and suggest that their control is disturbed locally by the presence of peptide growth factors during the development of fibrosis.