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1.
Hum Cell ; 35(1): 150-162, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34822133

RESUMO

MCM3AP-AS1 regulates the cartilage repair in osteoarthritis, but how it regulates osteogenic differentiation of dental pulp stem cells (DPSCs) remains to be determined. DPSCs were isolated and induced for osteogenic differentiation. MCM3AP-AS1 expression was increased along with the osteogenic differentiation of DPSCs, whose expression was positive correlated with those of OCN, alkaline phosphatase (ALP) and RUNX2. On contrary, miR-143-3p expression was decreased along with the osteogenic differentiation and was negatively correlated with those of OCN, ALP and RUNX2. Dual-luciferase reporter gene assay showed that miR-143-3p can be negatively regulated by MCM3AP-AS1 and can regulate IGFBP5. MCM3AP-AS1 overexpression increased the expression levels of osteogenesis-specific genes, ALP activity and mineralized nodules during DPSC osteogenic differentiation, while IGFBP5 knockdown or miR-143-3p overexpression counteracted the effect of MCM3AP-AS1 overexpression in DPSCs. Therefore, this study demonstrated the role of MCM3AP-AS1/miR-143-3p/IGFBP5 axis in regulating DPSC osteogenic differentiation.


Assuntos
Acetiltransferases/fisiologia , Diferenciação Celular/genética , Polpa Dentária/citologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Expressão Gênica/genética , Expressão Gênica/fisiologia , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , MicroRNAs/metabolismo , Osteogênese/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/fisiologia , Células-Tronco/fisiologia , Acetiltransferases/genética , Acetiltransferases/metabolismo , Fosfatase Alcalina/metabolismo , Diferenciação Celular/fisiologia , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Osteogênese/fisiologia , RNA Longo não Codificante/metabolismo , Células-Tronco/metabolismo
2.
Cells ; 9(12)2020 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-33276584

RESUMO

Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) play critical roles in membrane stability and cell signaling within the retina. ELOVL2 (Elongation of Very Long Chain Fatty Acids-Like 2), an elongase involved in the synthesis of long chain polyunsaturated fatty acids (LC-PUFAs), has recently been implicated in regulating aging in the mammalian retina. In this work, we characterize the expression and function of elovl2 in the retina development in embryonic zebrafish. Whole mount in situ hybridization shows elovl2 is expressed in the Muller glia in embryonic and adult zebrafish. Lipidomics analysis of elovl2 crispants whole embryos at day 2 and eyes at day 7 demonstrated significant changes in lipids composition, especially on the level of lipids containing docosahexaenoic acid (DHA). Histological analysis of zebrafish lacking elovl2 revealed increased retinal thickness compared to controls at day 7 without gross disruptions of the retinal architecture. Finally, elovl2 crispants showed differences in the visual motor reflex light off (VMR-OFF) at day 7 compared to controls. In sum, inactivation of elovl2 in zebrafish embryos caused changes in lipid composition and in visual behavior, further confirming the important role of LC-PUFAs in healthy vision.


Assuntos
Acetiltransferases/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Retina/embriologia , Retina/fisiologia , Visão Ocular , Proteínas de Peixe-Zebra/fisiologia , Acetiltransferases/metabolismo , Animais , Ácidos Docosa-Hexaenoicos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Hibridização In Situ , Lipidômica , Lipídeos/química , Neuroglia/metabolismo , Fenótipo , Peixe-Zebra
3.
Folia Biol (Praha) ; 66(3): 91-103, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33069188

RESUMO

The most recent genome-editing system called CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat system with associated protein 9-nuclease) was employed to delete four non-essential genes (i.e., Caeco1, Caidh1, Carom2, and Cataf10) individually to establish their gene functionality annotations in pathogen Candida albicans. The biological roles of these genes were investigated with respect to the cell wall integrity and biogenesis, calcium/calcineurin pathways, susceptibility of mutants towards temperature, drugs and salts. All the mutants showed increased vulnerability compared to the wild-type background strain towards the cell wall-perturbing agents, (antifungal) drugs and salts. All the mutants also exhibited repressed and defective hyphal growth and smaller colony size than control CA14. The cell cycle of all the mutants decreased enormously except for those with Carom2 deletion. The budding index and budding size also increased for all mutants with altered bud shape. The disposition of the mutants towards cell wall-perturbing enzymes disclosed lower survival and more rapid cell wall lysis events than in wild types. The pathogenicity and virulence of the mutants was checked by adhesion assay, and strains lacking rom2 and eco1 were found to possess the least adhesion capacity, which is synonymous to their decreased pathogenicity and virulence.


Assuntos
Candida albicans/fisiologia , Proteínas Fúngicas/fisiologia , Genes Fúngicos , Acetiltransferases/deficiência , Acetiltransferases/genética , Acetiltransferases/fisiologia , Antifúngicos/farmacologia , Sistemas CRISPR-Cas , Cálcio/fisiologia , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Candida albicans/patogenicidade , Cátions/farmacologia , Adesão Celular , Ciclo Celular , Parede Celular/efeitos dos fármacos , Quitinases/farmacologia , Dano ao DNA , Proteínas Fúngicas/genética , Deleção de Genes , Glucana Endo-1,3-beta-D-Glucosidase/farmacologia , Hifas/crescimento & desenvolvimento , Isocitrato Desidrogenase/deficiência , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/fisiologia , Fases de Leitura Aberta , Reprodução Assexuada , Fatores Associados à Proteína de Ligação a TATA/deficiência , Fatores Associados à Proteína de Ligação a TATA/genética , Fatores Associados à Proteína de Ligação a TATA/fisiologia , Virulência/genética
4.
Plant J ; 103(4): 1575-1589, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32433816

RESUMO

Arabidopsis thaliana AKR2A plays an important role in plant responses to cold stress. However, its exact function in plant resistance to cold stress remains unclear. In the present study, we found that the contents of very long-chain fatty acids (VLCFAs) in akr2a mutants were decreased, and the expression level of KCS1 was also reduced. Overexpression of KCS1 in the akr2a mutants could enhance VLCFAs contents and chilling tolerance. Yeast-2-hybrid and bimolecular fluorescence complementation (BIFC) results showed that the transmembrane motif of KCS1 interacts with the PEST motif of AKR2A both in vitro and in vivo. Overexpression of KCS1 in akr2a mutants rescued akr2a mutant phenotypes, including chilling sensitivity and a decrease of VLCFAs contents. Moreover, the transgenic plants co-overexpressing AKR2A and KCS1 exhibited a greater chilling tolerance than the plants overexpressing AKR2A or KCS1 alone, as well as the wild-type. AKR2A knockdown and kcs1 knockout mutants showed the worst performance under chilling conditions. These results indicate that AKR2A is involved in chilling tolerance via an interaction with KCS1 to affect VLCFA biosynthesis in Arabidopsis.


Assuntos
Acetiltransferases/fisiologia , Proteínas de Arabidopsis/fisiologia , Ácidos Graxos/metabolismo , Chaperonas Moleculares/fisiologia , Acetiltransferases/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Temperatura Baixa/efeitos adversos , Resposta ao Choque Frio , Ácidos Graxos/fisiologia , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Chaperonas Moleculares/genética , Fotossíntese , Plantas Geneticamente Modificadas , Técnicas do Sistema de Duplo-Híbrido
5.
Fish Physiol Biochem ; 46(4): 1349-1359, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32239337

RESUMO

Fish are a major source of beneficial n-3 LC-PUFA in human diet, and there is considerable interest to elucidate the mechanism and regulatory aspects of LC-PUFA biosynthesis in farmed species. Long-chain polyunsaturated fatty acid (LC-PUFA) biosynthesis involves the activities of two groups of enzymes, the fatty acyl desaturase (Fads) and elongase of very long-chain fatty acid (Elovl). The promoters of elovl5 elongase, which catalyses the rate-limiting reaction of elongating polyunsaturated fatty acid (PUFA), have been previously described and characterized from several marine and diadromous teleost species. We report here the cloning and characterization of elovl5 promoter from two freshwater fish species, the carnivorous snakehead fish (Channa striata) and zebrafish. Results show the presence of sterol-responsive elements (SRE) in the core regulatory region of both promoters, suggesting the importance of sterol regulatory element-binding protein (Srebp) in the regulation of elovl5 for both species. Mutagenesis luciferase and electrophoretic mobility shift assays further validate the role of SRE for basal transcriptional activation. In addition, several Sp1-binding sites located in close proximity with SRE were present in the snakehead promoter, with one having a potential synergy with SRE in the regulation of elovl5 expression. The core zebrafish elovl5 promoter fragment also directed in vivo expression in the yolk syncytial layer of developing zebrafish embryos.


Assuntos
Acetiltransferases/fisiologia , Peixes/fisiologia , Fator de Transcrição Sp1/fisiologia , Proteínas de Ligação a Elemento Regulador de Esterol/fisiologia , Ativação Transcricional/fisiologia , Proteínas de Peixe-Zebra/fisiologia , Peixe-Zebra/fisiologia , Animais , Clonagem Molecular , DNA/genética , DNA/isolamento & purificação , Luciferases/genética , Mutagênese Sítio-Dirigida , Regiões Promotoras Genéticas , Transfecção
6.
Elife ; 92020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-32065581

RESUMO

Eukaryotic genomes are folded into loops. It is thought that these are formed by cohesin complexes via extrusion, either until loop expansion is arrested by CTCF or until cohesin is removed from DNA by WAPL. Although WAPL limits cohesin's chromatin residence time to minutes, it has been reported that some loops exist for hours. How these loops can persist is unknown. We show that during G1-phase, mammalian cells contain acetylated cohesinSTAG1 which binds chromatin for hours, whereas cohesinSTAG2 binds chromatin for minutes. Our results indicate that CTCF and the acetyltransferase ESCO1 protect a subset of cohesinSTAG1 complexes from WAPL, thereby enable formation of long and presumably long-lived loops, and that ESCO1, like CTCF, contributes to boundary formation in chromatin looping. Our data are consistent with a model of nested loop extrusion, in which acetylated cohesinSTAG1 forms stable loops between CTCF sites, demarcating the boundaries of more transient cohesinSTAG2 extrusion activity.


Assuntos
Acetiltransferases/fisiologia , Fator de Ligação a CCCTC/fisiologia , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Acetilação , Proteínas de Transporte/genética , Simulação por Computador , Fase G1 , Genoma Humano , Humanos , Proteínas Nucleares/genética , Ligação Proteica , Proteínas Proto-Oncogênicas/genética
7.
Life Sci Alliance ; 3(3)2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32051254

RESUMO

In mitotic cells, establishment of sister chromatid cohesion requires acetylation of the cohesin subunit SMC3 (acSMC3) by ESCO1 and/or ESCO2. Meiotic cohesin plays additional but poorly understood roles in the formation of chromosome axial elements (AEs) and synaptonemal complexes. Here, we show that levels of ESCO2, acSMC3, and the pro-cohesion factor sororin increase on meiotic chromosomes as homologs synapse. These proteins are less abundant on the largely unsynapsed sex chromosomes, whose sister chromatid cohesion appears weaker throughout the meiotic prophase. Using three distinct conditional Esco2 knockout mouse strains, we demonstrate that ESCO2 is essential for male gametogenesis. Partial depletion of ESCO2 in prophase I spermatocytes delays chromosome synapsis and further weakens cohesion along sex chromosomes, which show extensive separation of AEs into single chromatids. Unsynapsed regions of autosomes are associated with the sex chromatin and also display split AEs. This study provides the first evidence for a specific role of ESCO2 in mammalian meiosis, identifies a particular ESCO2 dependence of sex chromosome cohesion and suggests support of autosomal synapsis by acSMC3-stabilized cohesion.


Assuntos
Acetiltransferases/metabolismo , Cromátides/metabolismo , Pareamento Cromossômico/fisiologia , Acetilação , Acetiltransferases/genética , Acetiltransferases/fisiologia , Animais , Proteínas de Ciclo Celular , Cromátides/genética , Proteínas Cromossômicas não Histona , Pareamento Cromossômico/genética , Segregação de Cromossomos/genética , Segregação de Cromossomos/fisiologia , Estruturas Cromossômicas/metabolismo , Gametogênese/genética , Masculino , Meiose/genética , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Nucleares/genética , Cromossomos Sexuais/metabolismo , Espermatócitos/metabolismo , Complexo Sinaptonêmico/metabolismo
8.
Genes Genet Syst ; 94(5): 197-206, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31694990

RESUMO

Genome instability is a cause of cellular senescence. The ribosomal RNA gene repeat (rDNA) is one of the most unstable regions in the genome and its instability is proposed to be a major inducer of cellular senescence and restricted lifespan. We previously conducted a genome-wide screen using a budding yeast deletion library to identify mutants that exhibit a change in the stability of the rDNA region, compared to the wild-type. To investigate the correlation between rDNA stability and lifespan, we examined deletion mutants with very stable rDNA and found that deletion of EAF3, encoding a component of the NuA4 histone acetyltransferase complex, reproducibly resulted in increased stabilization of the rDNA. In the absence of Eaf3, and of other subunits of the NuA4 complex, we observed lower levels of extrachromosomal rDNA circles that are produced by recombination in the rDNA and are thus an indicator of rDNA instability. The replicative lifespan in the eaf3 mutant was extended by ~30%, compared to the wild-type strain. Our findings provide evidence that rDNA stability is correlated with extended replicative lifespan. The eaf3 mutation possibly affects the non-coding transcription in rDNA that regulates rDNA recombination through cohesin dissociation.


Assuntos
Senescência Celular/genética , DNA Ribossômico/fisiologia , Genes de RNAr , Histona Acetiltransferases/fisiologia , Proteínas de Saccharomyces cerevisiae/fisiologia , Acetiltransferases/genética , Acetiltransferases/fisiologia , Proteínas de Ligação a DNA/fisiologia , Regulação Fúngica da Expressão Gênica , Instabilidade Genômica , Histona Acetiltransferases/genética , Mutação , Proteínas de Saccharomyces cerevisiae/genética , Proteínas Reguladoras de Informação Silenciosa de Saccharomyces cerevisiae/fisiologia , Sirtuína 2/fisiologia
9.
Nat Chem Biol ; 15(3): 285-294, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30718814

RESUMO

GCN5-related N-acetyl-transferase (GNAT)-like enzymes from toxin-antitoxin modules are strong inhibitors of protein synthesis. Here, we present the bases of the regulatory mechanisms of ataRT, a model GNAT-toxin-antitoxin module, from toxin synthesis to its action as a transcriptional de-repressor. We show the antitoxin (AtaR) traps the toxin (AtaT) in a pre-catalytic monomeric state and precludes the effective binding of ac-CoA and its target Met-transfer RNAfMet. In the repressor complex, AtaR intrinsically disordered region interacts with AtaT at two different sites, folding into different structures, that are involved in two separate functional roles, toxin neutralization and placing the DNA-binding domains of AtaR in a binding-compatible orientation. Our data suggests AtaR neutralizes AtaT as a monomer, right after its synthesis and only the toxin-antitoxin complex formed in this way is an active repressor. Once activated by dimerization, later neutralization of the toxin results in a toxin-antitoxin complex that is not able to repress transcription.


Assuntos
Acetiltransferases/metabolismo , Antitoxinas/fisiologia , Sistemas Toxina-Antitoxina/fisiologia , Acetiltransferases/fisiologia , Arilamina N-Acetiltransferase , Proteínas de Bactérias , Toxinas Bacterianas/metabolismo , Escherichia coli/enzimologia , Escherichia coli/metabolismo , Biossíntese de Proteínas/fisiologia , Salmonella/enzimologia , Salmonella/metabolismo , Sistemas Toxina-Antitoxina/genética
10.
Nephron ; 143(1): 17-23, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30625494

RESUMO

BACKGROUND: The recent growing evidence that the proximal tubule underlies the early pathogenesis of diabetic kidney disease (DKD) is unveiling novel and promising perspectives. This pathophysiological concept links tubulointerstitial oxidative stress, inflammation, hypoxia, and fibrosis with the progression of DKD. In this new angle for DKD, the prevailing molecular mechanisms on proximal tubular cells emerge as an innovative opportunity for prevention and management of DKD as well as to improve diabetic dysmetabolism. SUMMARY: The mercapturate pathway (MAP) is a classical metabolic detoxification route for xenobiotics that is emerging as an integrative circuitry detrimental to resolve tubular inflammation caused by endogenous electrophilic species. Herein we review why and how it might underlie DKD. Key Messages: MAP is a hallmark of proximal tubular cell function, and cysteine-S-conjugates might represent targets for early intervention in DKD. Moreover, the biomonitoring of urinary mercapturates from metabolic inflammation products might be relevant for the implementation of preventive/management strategies in DKD.


Assuntos
Acetilcisteína/metabolismo , Nefropatias Diabéticas/metabolismo , Túbulos Renais Proximais/metabolismo , Acetiltransferases/fisiologia , Cisteína/metabolismo , Nefropatias Diabéticas/etiologia , Humanos , Túbulos Renais Proximais/citologia , Leucotrienos/metabolismo , Estresse Oxidativo
11.
Gene ; 666: 134-144, 2018 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-29733968

RESUMO

Elongase of very long-chain fatty acids 6 (ELOVL6) is a rate-limiting enzyme catalyzing elongation of saturated and monounsaturated long-chain fatty acid. Although functional characteristics of Elovl6 have been demonstrated in mammal, the role of elovl6 in fish remains unclear. In this study, we firstly cloned three isoforms of elovl6 (elovl6a, elovl6b and elovl6-like) from loach (Misgurnus anguillicaudatus). Molecular characterizations of the three elovl6 isoforms in loach and their expressions of early life stages and different tissues were then determined. We also functionally characterized the three elovl6 isoforms using heterologous expression in baker's yeast. Results obtained here showed the three elovl6 proteins in loach can elongate C16:0 and C16:1 to C18:0 and C18:1, respectively. At last, to confirm the role of three loach elovl6 isoforms for elongation of fatty acids in adaption to cold stress, differences in skin histological structures, body fatty acid compositions, expressions of four hepatic lipogenesis or lipolysis related genes, and expressions of the three elovl6 isoforms and their related gene uncoupling protein 1 (ucp1) in different tissues were investigated in the loach reared in two different water temperatures (28 °C and 4 °C) for ten days. Cold stress increased ratios of C18/C16 and C20:5n-3/C18:3n-3 in loach body, and induced expressions of hepatic acyl-CoA delta-9 desaturase 1 (scd1), sterol-regulator element-binding protein 1 (srebp1), carnitine palmitoyltransferase 1 (cpt1) and fatty acid synthase (fas). Meanwhile, significant differences were found in expressions of the three elovl6 isoforms in different tissues between 28 °C and 4 °C groups. Overall, this study suggests that the three elovl6 isoforms in loach have ability to elongate C16 to C18, and elovl6 proteins in loach may play a role in adaptation to cold stress.


Assuntos
Acetiltransferases/fisiologia , Resposta ao Choque Frio , Proteínas de Peixes/fisiologia , Termotolerância , Sequência de Aminoácidos , Animais , Cipriniformes , Elongases de Ácidos Graxos , Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Isoenzimas/fisiologia , Fases de Leitura Aberta , Especificidade de Órgãos , Filogenia
12.
Cell Metab ; 27(4): 914-925.e5, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29551589

RESUMO

Whether and how regulation of genes and pathways contributes to physiological aging is topic of intense scientific debate. By performing an RNA expression-based screen for genes downregulated during aging of three different species, we identified glycine-C-acetyltransferase (GCAT, EC 2.3.1.29). Impairing gcat expression promotes the lifespan of C. elegans by interfering with threonine catabolism to promote methylglyoxal (MGO; CAS 78-98-8) formation in an amine oxidase-dependent manner. MGO is a reactive dicarbonyl inducing diabetic complications in mammals by causing oxidative stress and damaging cellular components, including proteins. While high concentrations of MGO consistently exert toxicity in nematodes, we unexpectedly find that low-dose MGO promotes lifespan, resembling key mediators of gcat impairment. These were executed by the ubiquitin-proteasome system, namely PBS-3 and RPN-6.1 subunits, regulated by the stress-responsive transcriptional regulators SKN-1/NRF2 and HSF-1. Taken together, GCAT acts as an evolutionary conserved aging-related gene by orchestrating an unexpected nonlinear impact of proteotoxic MGO on longevity.


Assuntos
Acetiltransferases/fisiologia , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Aldeído Pirúvico/metabolismo , Treonina/metabolismo , Acetiltransferases/genética , Animais , Proteínas de Ligação a DNA/metabolismo , Longevidade/fisiologia , Estresse Oxidativo , Transdução de Sinais , Fatores de Transcrição/metabolismo
13.
Nucleic Acids Res ; 46(5): 2335-2346, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29361031

RESUMO

Esco1 has been reported to function as a cohesion establishment factor that mediates chromosome cohesion and segregation in mitotic cells. However, its exact roles in meiosis have not been clearly defined. Here, we document that Esco1 is expressed and localized to both the nucleus and cytoplasm during mouse oocyte meiotic maturation. Depletion of Esco1 by siRNA microinjection causes the meiotic progression arrest with a severe spindle abnormality and chromosome misalignment, which is coupled with a higher incidence of the erroneous kinetochore-microtubule attachments and activation of spindle assembly checkpoint. In addition, depletion of Esco1 leads to the impaired microtubule stability shown by the weakened resistance ability to the microtubule depolymerizing drug nocodazole and the decreased level of acetylated α-tubulin. Conversely, overexpression of Esco1 causes hyperacetylation of α-tubulin and spindle defects. Moreover, we find that Esco1 binds to α-tubulin and is required for its acetylation. The reduced acetylation level of α-tubulin in Esco1-depleted oocytes can be restored by the ectopic expression of exogenous wild-type Esco1 but not enzymatically dead Esco1-G768D. Purified wild-type Esco1 instead of mutant Esco1-G768D acetylates the synthesized peptide of α-tubulin in vitro. Collectively, our data assign a novel function to Esco1 as a microtubule regulator during oocyte meiotic maturation beyond its conventional role in chromosome cohesion.


Assuntos
Acetiltransferases/metabolismo , Meiose , Oócitos/metabolismo , Fuso Acromático/metabolismo , Tubulina (Proteína)/metabolismo , Acetilação , Acetiltransferases/fisiologia , Animais , Cromossomos de Mamíferos , Citoplasma/metabolismo , Feminino , Cinetocoros/metabolismo , Lisina/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular , Meiose/genética , Camundongos Endogâmicos ICR , Microtúbulos/metabolismo , Oócitos/enzimologia , Tubulina (Proteína)/química
14.
Mol Nutr Food Res ; 62(1)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28980402

RESUMO

Although dietary fatty acids can modulate metabolic and immune responses, the effects of palmitoleic acid (16:1n-7) remain unclear. Since this monounsaturated fatty acid is described as a lipokine, studies with cell culture and rodent models have suggested it enhances whole body insulin sensitivity, stimulates insulin secretion by ß cells, increases hepatic fatty acid oxidation, improves the blood lipid profile, and alters macrophage differentiation. However, human studies report elevated blood levels of palmitoleic acid in people with obesity and metabolic syndrome. These findings might be reflection of the level or activity of stearoyl-CoA desaturase-1, which synthesizes palmitoleate and is enhanced in liver and adipose tissue of obese patients. The aim of this review is to describe the immune-metabolic effects of palmitoleic acid observed in cell culture, animal models, and humans to answer the question of whether palmitoleic acid is a plausible nonpharmacological strategy to prevent, control, or ameliorate chronic metabolic and inflammatory disorders. Despite the beneficial effects observed in cell culture and in animal studies, there are insufficient human intervention studies to fully understand the physiological effects of palmitoleic acid. Therefore, more human-based research is needed to identify whether palmitoleic acid meets the promising therapeutic potential suggested by the preclinical research.


Assuntos
Ácidos Graxos Monoinsaturados/uso terapêutico , Síndrome Metabólica/tratamento farmacológico , Obesidade/tratamento farmacológico , Acetiltransferases/fisiologia , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/prevenção & controle , LDL-Colesterol/sangue , Elongases de Ácidos Graxos , Humanos , Resistência à Insulina , Síndrome Metabólica/prevenção & controle , Obesidade/prevenção & controle , Estearoil-CoA Dessaturase/fisiologia
15.
Nucleic Acids Res ; 45(16): 9388-9397, 2017 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-28934466

RESUMO

Sister chromatid cohesion, mediated by cohesin complex and established by the acetyltransferases Esco1 and Esco2, is essential for faithful chromosome segregation. Mutations in Esco2 cause Roberts syndrome, a developmental disease characterized by severe prenatal retardation as well as limb and facial abnormalities. However, its exact roles during oocyte meiosis have not clearly defined. Here, we report that Esco2 localizes to the chromosomes during oocyte meiotic maturation. Depletion of Esco2 by morpholino microinjection leads to the precocious polar body extrusion, the escape of metaphase I arrest induced by nocodazole treatment and the loss of BubR1 from kinetochores, indicative of inactivated SAC. Furthermore, depletion of Esco2 causes a severely impaired spindle assembly and chromosome alignment, accompanied by the remarkably elevated incidence of defective kinetochore-microtubule attachments which consequently lead to the generation of aneuploid eggs. Notably, we find that the involvement of Esco2 in SAC and kinetochore functions is mediated by its binding to histone H4 and acetylation of H4K16 both in vivo and in vitro. Thus, our data assign a novel meiotic function to Esco2 beyond its role in the cohesion establishment during mouse oocyte meiosis.


Assuntos
Acetiltransferases/metabolismo , Histonas/metabolismo , Cinetocoros/metabolismo , Pontos de Checagem da Fase M do Ciclo Celular/genética , Meiose/genética , Oócitos/enzimologia , Acetilação , Acetiltransferases/fisiologia , Aneuploidia , Animais , Cromossomos de Mamíferos/enzimologia , Feminino , Histonas/química , Lisina/metabolismo , Camundongos Endogâmicos ICR , Fuso Acromático/metabolismo
16.
Proc Natl Acad Sci U S A ; 114(37): 9906-9911, 2017 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-28847955

RESUMO

Sister chromatids are tethered together by the cohesin complex from the time they are made until their separation at anaphase. The ability of cohesin to tether sister chromatids together depends on acetylation of its Smc3 subunit by members of the Eco1 family of cohesin acetyltransferases. Vertebrates express two orthologs of Eco1, called Esco1 and Esco2, both of which are capable of modifying Smc3, but their relative contributions to sister chromatid cohesion are unknown. We therefore set out to determine the precise contributions of Esco1 and Esco2 to cohesion in vertebrate cells. Here we show that cohesion establishment is critically dependent upon Esco2. Although most Smc3 acetylation is Esco1 dependent, inactivation of the ESCO1 gene has little effect on mitotic cohesion. The unique ability of Esco2 to promote cohesion is mediated by sequences in the N terminus of the protein. We propose that Esco1-dependent modification of Smc3 regulates almost exclusively the noncohesive activities of cohesin, such as DNA repair, transcriptional control, chromosome loop formation, and/or stabilization. Collectively, our data indicate that Esco1 and Esco2 contribute to distinct and separable activities of cohesin in vertebrate cells.


Assuntos
Acetiltransferases/metabolismo , Cromátides/fisiologia , Proteínas Cromossômicas não Histona/metabolismo , Acetilação , Acetiltransferases/fisiologia , Sequência de Bases , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/fisiologia , Divisão Celular/fisiologia , Cromátides/metabolismo , Proteínas Cromossômicas não Histona/fisiologia , Segregação de Cromossomos/fisiologia , Replicação do DNA/fisiologia , Regulação da Expressão Gênica/genética , Humanos , Proteínas Nucleares/metabolismo
17.
Diabetes ; 66(7): 1833-1846, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28461456

RESUMO

Dysfunctional fatty acid (FA) metabolism plays an important role in the pathogenesis of ß-cell dysfunction and loss of ß-cell mass in type 2 diabetes (T2D). Elovl6 is a microsomal enzyme that is responsible for converting C16 saturated and monounsaturated FAs into C18 species. We previously showed that Elovl6 played a critical role in the development of obesity-induced insulin resistance by modifying FA composition. To further define its role in T2D development, we assessed the effects of Elovl6 deletion in leptin receptor-deficient C57BL/KsJ db/db mice, a model of T2D. The db/db;Elovl6-/- mice had a markedly increased ß-cell mass with increased proliferation and decreased apoptosis, an adaptive increase in insulin, and improved glycemic control. db/db islets were characterized by a prominent elevation of oleate (C18:1n-9), cell stress, and inflammation, which was completely suppressed by Elovl6 deletion. As a mechanistic ex vivo experiment, isolated islets from Elovl6-/- mice exhibited reduced susceptibility to palmitate-induced inflammation, endoplasmic reticulum stress, and ß-cell apoptosis. In contrast, oleate-treated islets resulted in impaired glucose-stimulated insulin secretion with suppressed related genes irrespective of the Elovl6 gene. Taken together, Elovl6 is a fundamental factor linking dysregulated lipid metabolism to ß-cell dysfunction, islet inflammation, and ß-cell apoptosis in T2D, highlighting oleate as the potential culprit of ß-cell lipotoxicity.


Assuntos
Acetiltransferases/deficiência , Acetiltransferases/genética , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Tipo 2/genética , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Acetiltransferases/fisiologia , Animais , Apoptose/genética , Glicemia/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Estresse do Retículo Endoplasmático , Elongases de Ácidos Graxos , Ácidos Graxos não Esterificados/metabolismo , Feminino , Imuno-Histoquímica , Técnicas In Vitro , Inflamação/induzido quimicamente , Inflamação/genética , Secreção de Insulina , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Ilhotas Pancreáticas/patologia , Metabolismo dos Lipídeos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ácido Oleico/farmacologia , Tamanho do Órgão , Palmitatos/efeitos adversos , Reação em Cadeia da Polimerase em Tempo Real , Receptores para Leptina/genética
18.
J Dairy Sci ; 100(6): 4987-4995, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28390727

RESUMO

In nonruminants, it is well established that elongation of very long-chain fatty acid-like fatty acid elongase 6 (ELOVL6) catalyzes the synthesis of C18:0 from C16:0 in lipogenic tissues like adipose and liver. However, the role of ELOVL6 in regulating lipid metabolism in ruminant mammary gland remains unknown. In the present study, ELOVL6 was overexpressed or knocked down via adenoviral transfection to assess its role in goat mammary epithelial cells. Results revealed that ELOVL6 overexpression had a weak effect on the expression of genes related to triacylglycerol (TAG) synthesis and desaturation. Overexpression of ELOVL6 increased the content of C18:0 at the expense of C16:0, and increased the elongation index of C16:0. Overexpression of ELOVL6 had no significant effect on the elongation index of C16:1n-7 and the desaturation indices of C16:0 and C18:0. Knockdown of ELOVL6 had a negative effect on mRNA expression of the esterification genes GPAM and diacylglycerolacyltransferase 2 (DGAT2) and TAG concentration; however, it increased the concentration of C16:0 and decreased C18:1n-7 and C18:1n-9 in goat mammary epithelial cells. Accordingly, downregulation of ELOVL6 significantly decreased the elongation indices of C16:0 and C16:1n-7. The lack of change in the desaturation indices of C16:0 and C18:0 upon knockdown of ELOVL6 was consistent with the minor change in SCD1 expression. In conclusion, these are the first results highlighting an important role of ELOVL6 in long-chain fatty elongation and TAG synthesis in ruminant mammary cells.


Assuntos
Acetiltransferases/fisiologia , Células Epiteliais/metabolismo , Ácidos Graxos/biossíntese , Glândulas Mamárias Animais/citologia , Triglicerídeos/biossíntese , Acetiltransferases/genética , Animais , Diacilglicerol O-Aciltransferase , Esterificação/genética , Elongases de Ácidos Graxos , Feminino , Técnicas de Silenciamento de Genes/veterinária , Cabras , RNA Mensageiro/metabolismo , Triglicerídeos/genética
19.
PLoS One ; 11(7): e0159375, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27467521

RESUMO

ELOVL family member 6, elongation of very long chain fatty acids (Elovl6) is a microsomal enzyme, which regulates the elongation of C12-16 saturated and monounsaturated fatty acids. Elovl6 has been shown to be associated with various pathophysiologies including insulin resistance, atherosclerosis, and non-alcoholic steatohepatitis. To investigate a potential role of Elovl6 during bone development, we here examined a skeletal phenotype of Elovl6 knockout (Elovl6-/-) mice. The Elovl6-/- skeleton was smaller than that of controls, but exhibited no obvious patterning defects. Histological analysis revealed a reduced length of proliferating and an elongated length of hypertrophic chondrocyte layer, and decreased trabecular bone in Elovl6-/- mice compared with controls. These results were presumably due to a modest decrease in chondrocyte proliferation and accelerated differentiation of cells of the chondrocyte lineage. Consistent with the increased length of the hypertrophic chondrocyte layer in Elovl6-/- mice, Collagen10α1 was identified as one of the most affected genes by ablation of Elovl6 in chondrocytes. Furthermore, this elevated expression of Collagen10α1 of Elovl6-null chondrocytes was likely associated with increased levels of Foxa2/a3 and Mef2c mRNA expression. Relative increases in protein levels of nuclear Foxa2 and cytoplasmic histone deacethylase 4/5/7 were also observed in Elovl6 knockdown cells of the chondrocyte lineage. Collectively, our data suggest that Elovl6 plays a critical role for proper development of embryonic growth plate.


Assuntos
Acetiltransferases/fisiologia , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Condrócitos/citologia , Lâmina de Crescimento/crescimento & desenvolvimento , Acetiltransferases/genética , Animais , Condrócitos/metabolismo , Elongases de Ácidos Graxos , Camundongos , Camundongos Knockout , Osteoblastos/metabolismo
20.
Oncotarget ; 7(34): 55789-55810, 2016 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-27322556

RESUMO

Lysine acetylation is a post-translational modification that regulates gene transcription by targeting histones as well as a variety of transcription factors in the nucleus. Recently, several reports have demonstrated that numerous cytosolic proteins are also acetylated and that this modification, affecting protein activity, localization and stability has profound consequences on their cellular functions. Interestingly, most non-histone proteins targeted by acetylation are relevant for tumorigenesis. In this review, we will analyze the functional implications of lysine acetylation in different cellular compartments, and will examine our current understanding of lysine acetyltransferases family, highlighting the biological role and prognostic value of these enzymes and their substrates in cancer. The latter part of the article will address challenges and current status of molecules targeting lysine acetyltransferase enzymes in cancer therapy.


Assuntos
Lisina Acetiltransferases/fisiologia , Lisina/metabolismo , Neoplasias/tratamento farmacológico , Acetilação , Acetiltransferases/fisiologia , Animais , Biomarcadores , Humanos , Lisina Acetiltransferases/antagonistas & inibidores , Camundongos , Proteínas dos Microtúbulos , Neoplasias/metabolismo , Prognóstico , Processamento de Proteína Pós-Traducional , Fatores de Transcrição de p300-CBP/fisiologia
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