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1.
Healthcare (Basel) ; 12(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38667575

RESUMO

After the global challenges posed by COVID-19, researchers strived to identify risk factors for severe cases, which lead to various complications-including death. Lifestyle modifications, such as implementing a healthy diet and recommended physical activity, have been shown to be protective against severe COVID-19 cases. Despite an association of a plant-based diet with reduced COVID-19 severity, specific dietary characteristics have not been identified. Also, the methodology for measuring physical activity is variable, with studies overlooking the intensity or the habit components of physical activity. To bridge this gap, our study designed, validated, and applied a retrospective questionnaire with aims of exploring the relationship between lifestyle factors, specifically diet and physical activity, and severe COVID-19. We considered the intensity and years of physical activity habit, which is a limitation of other questionnaires. Results reveal associations of age and BMI with severe COVID-19. An excessive sugar diet was found to be associated with severe COVID-19 and increased symptom duration. We also observed an inverse relationship pattern of moderate- and vigorous-intensity physical activity across case severity, which is absent in walking physical activity. This study lays a foundation for research aiming to identify lifestyle factors that prevent severe COVID-19 cases.

2.
Healthcare (Basel) ; 11(16)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37628530

RESUMO

The n-3 polyunsaturated fatty acids (PUFAs) can reduce inflammatory markers and may therefore be useful in obesity management. The aim of this study was to analyze the effect of supplementation with n-3 PUFAs on total fatty acid profile in red blood cells (RBCs), as well as biochemical and inflammatory markers, in subjects with obesity. The study consisted in a randomized placebo-controlled, double-blind clinical trial involving 41 subjects with obesity during a 4-month follow-up. Individuals were randomly assigned to two groups: n-3 PUFA supplementation (1.5 g fish oil) and placebo (1.5 g sunflower oil). Anthropometric, biochemical, dietetic, cytokine and total fatty acid profiles in RBCs were measured. Both groups increased their PUFA intake and DHA incorporation in RBCs. However, the placebo group showed a reduction in serum IL-8 and MCP-1 at the end of the study. A multiple linear regression model adjusted by body fat mass and sex showed that an increase in DHA in RBCs decreased the serum IL-8 levels in both study groups at the end of the study. Our results highlight the role of dietary DHA and n-3 supplementation usefulness in exerting beneficial anti-inflammatory effects.

3.
Healthcare (Basel) ; 11(14)2023 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-37510432

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is closely associated with other metabolic disease and cardiovascular disease. Regular exercise reduces hepatic fat content and could be the first-line treatment in the management of NAFLD. This review aims to summarize the current evidence of the beneficial effects of exercise training and identify the molecular pathways involved in the response to exercise to define their role in the resolution of NAFLD both in animal and human studies. According to the inclusion criteria, 43 animal studies and 14 RCTs were included in this systematic review. Several exercise modalities were demonstrated to have a positive effect on liver function. Physical activity showed a strong association with improvement in inflammation, and reduction in steatohepatitis and fibrosis in experimental models. Furthermore, both aerobic and resistance exercise in human studies were demonstrated to reduce liver fat, and to improve insulin resistance and blood lipids, regardless of weight loss, although aerobic exercises may be more effective. Resistance exercise is more feasible for patients with NAFLD with poor cardiorespiratory fitness. More effort and awareness should be dedicated to encouraging NAFLD patients to adopt an active lifestyle and benefit from it its effects in order to reduce this growing public health problem.

4.
Nucleic Acids Res ; 51(11): 5396-5413, 2023 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-36971114

RESUMO

The deubiquitinating enzyme Ataxin-3 (ATXN3) contains a polyglutamine (PolyQ) region, the expansion of which causes spinocerebellar ataxia type-3 (SCA3). ATXN3 has multiple functions, such as regulating transcription or controlling genomic stability after DNA damage. Here we report the role of ATXN3 in chromatin organization during unperturbed conditions, in a catalytic-independent manner. The lack of ATXN3 leads to abnormalities in nuclear and nucleolar morphology, alters DNA replication timing and increases transcription. Additionally, indicators of more open chromatin, such as increased mobility of histone H1, changes in epigenetic marks and higher sensitivity to micrococcal nuclease digestion were detected in the absence of ATXN3. Interestingly, the effects observed in cells lacking ATXN3 are epistatic to the inhibition or lack of the histone deacetylase 3 (HDAC3), an interaction partner of ATXN3. The absence of ATXN3 decreases the recruitment of endogenous HDAC3 to the chromatin, as well as the HDAC3 nuclear/cytoplasm ratio after HDAC3 overexpression, suggesting that ATXN3 controls the subcellular localization of HDAC3. Importantly, the overexpression of a PolyQ-expanded version of ATXN3 behaves as a null mutant, altering DNA replication parameters, epigenetic marks and the subcellular distribution of HDAC3, giving new insights into the molecular basis of the disease.


Assuntos
Ataxina-3 , Cromatina , Replicação do DNA , Humanos , Ataxina-3/genética , Ataxina-3/metabolismo , Cromatina/genética , Dano ao DNA , Doença de Machado-Joseph/genética , Proteínas Repressoras/metabolismo
5.
Diabetes Metab Syndr Obes ; 15: 1771-1784, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35711690

RESUMO

Purpose: Differences in metformin effect on glycemic control in type 2 Diabetes (T2D) have been associated with diet, obesity, years since T2D diagnosis and genetic factors, such as the Met408Val (rs628031) SLC22A1/OCT1 gene polymorphism. This study aimed to analyze the effect of metformin and diet on glycemic control and its association with the Met408Val polymorphism in patients with T2D from western Mexico. Patients and Methods: A total of 240 T2D adult patients were enrolled in this cross-sectional study. Anti-hyperglycemic therapy, dietary intake, body composition and glycemic profile were recorded and the determination of genotypes of SLC22A1/OCT1 gene (rs628031) was performed using an allelic discrimination assay. Results: The type of metformin therapy was 47% monotherapy, 45% dual therapy (metformin+glibenclamide or metformin+insulin) and 8% triple therapy (metformin+glibenclamide+insulin). Individuals with metformin monotherapy had a higher glycemic control frequency (%HbA1c <7.0) compared with the dual and triple treatment schemes (77% vs 35% and 15%, respectively; p<0.001). Interestingly, a high potassium intake was documented in the three anti-hyperglycemic therapies and a lower intake of micronutrients, including calcium, magnesium, and zinc. An interaction was found between calcium intake and carriers of the risk allele A (408Val) with %HbA1c (P interaction=0.028), and potassium intake with the TyG index (P interaction=0.027). In addition, there was a positive correlation between calcium intake and %HbA1c (r=0.682; p=0.010), and potassium intake vs TyG index (r=0.593; p=0.033) in risk allele A (408Val) carriers with metformin monotherapy. Genotype frequencies were GG homozygotes (76.6%), GA heterozygotes (21.5%) and AA homozygotes (1.9%). The allele frequency was 87.4% for the ancestral allele G and 12.6% for the risk allele A. Conclusion: These findings suggest a differing effect of metformin on glycemic control regarding calcium and potassium intake and the Met408Val SLC22A1/OCT1 gene polymorphism in T2D patients.

6.
J Hum Nutr Diet ; 35(4): 713-721, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34750902

RESUMO

BACKGROUND: The ACTN3 gene is primarily expressed in fast skeletal muscle fibres. A common nonsense polymorphism in this gene is ACTN3 R577X (rs1815739), which causes an absolute deficiency of α-actinin-3 protein and alterations in muscle metabolism. Considering metabolic alterations are influenced by nutrition and genetic factors, as well as lifestyle factors, we hypothesise a possible association of the ACTN3 R577X polymorphism with metabolic alterations. METHODS: In this cross-sectional study, 397 adults met the inclusion criteria. Body composition was measured by electrical bioimpedance. Dietary data were analysed using Nutritionist Pro™ software. Biochemical variables were determined by dry chemistry. Genomic DNA was extracted from peripheral leukocytes and genotyping of the ACTN3 R577X polymorphism was determined by allelic discrimination using TaqMan probes. The statistical analyses were performed using SPSS statistical software. p < 0.05 was considered statistically significant. RESULTS: The ACTN3 577XX genotype was associated with high glucose, triglyceride and very low density lipoprotein-cholesterol levels and a higher frequency of hypertriglyceridaemia and insulin resistance in women. In males, the genetic variant showed a trend towards significance for insulin resistance. CONCLUSIONS: The ACTN3 R577X polymorphism was associated with metabolic alterations in women and a tendency was observed in men variant carriers. Thus, this common genetic variant could be implicated in the development of chronic metabolic diseases.


Assuntos
Actinina , Resistência à Insulina , Actinina/genética , Adulto , Estudos Transversais , Feminino , Genótipo , Humanos , Resistência à Insulina/genética , Masculino , México , Polimorfismo Genético
7.
Biochem Biophys Res Commun ; 543: 45-49, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33515911

RESUMO

In order to control the COVID-19 pandemic caused by SARS-CoV-2 infection, serious progress has been made to identify infected patients and to detect patients with a positive immune response against the virus. Currently, attempts to generate a vaccine against the coronavirus are ongoing. To understand SARS-CoV-2 immunoreactivity, we compared the IgG antibody response against SARS-CoV-2 in infected versus control patients by dot blot using recombinant viral particle proteins: N (Nucleocapsid), M (Membrane) and S (Spike). In addition, we used different protein fragments of the N and S protein to map immune epitopes. Most of the COVID-19 patients presented a specific immune response against the full length and fragments of the N protein and, to lesser extent, against a fragment containing amino acids 300-685 of the S protein. In contrast, immunoreactivity against other S protein fragments or the M protein was low. This response is specific for COVID-19 patients as very few of the control patients displayed immunoreactivity, likely reflecting an immune response against other coronaviruses. Altogether, our results may help develop method(s) for measuring COVID-19 antibody response, selectivity of methods detecting such SARS-CoV-2 antibodies and vaccine development.


Assuntos
COVID-19/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , SARS-CoV-2/imunologia , Proteínas M de Coronavírus/genética , Proteínas M de Coronavírus/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/genética , Humanos , Soros Imunes/imunologia , Imunidade Humoral , Immunoblotting , Imunoglobulina G/sangue , Fosfoproteínas/genética , Fosfoproteínas/imunologia , SARS-CoV-2/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Vírion/imunologia
8.
Genes Nutr ; 15(1): 15, 2020 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-32854610

RESUMO

BACKGROUND: Obesity is characterized by low-grade chronic inflammation and an excess of adipose tissue. The ASC gene encodes a protein that is part of the NLRP3 inflammasome, a cytosolic multiprotein complex that is associated with inflammation and metabolic alterations. To our knowledge, there is no evidence regarding ASC gene activity in obese adults in response to lifestyle modifications. PURPOSE: To evaluate the effect of hypocaloric diet and moderate-intensity structured exercise intervention on ASC gene expression and inflammatory markers in obese adults. METHODS: Thirty-seven obese individuals aged 25 to 50 years were randomized to the hypocaloric diet exercise group or hypocaloric diet group. The participants underwent a 4-month follow-up. Electrical bioimpedance was used for body composition analysis. Biochemical data were analyzed by dry chemistry and insulin levels by ELISA. ASC gene expression from peripheral blood was performed using real-time PCR. Dietary data was collected through questionnaires and analyzed using the Nutritionist Pro™ software. Quantification of cytokines was conducted using Bio-Plex Pro™ Human cytokine. The Astrand-Ryhming test was used to estimate the maximum oxygen volume and design the moderate-intensity structured exercise program ~ 75% heart rate (HR) RESULTS: After the intervention, both study groups significantly improved body composition (decreased weight, fat mass, waist circumference and abdominal obesity, p < 0.05). Besides, the diet-exercise group significantly decreased ASC mRNA expression, MCP-1, and MIP-1ß inflammatory cytokines compared to the diet group (p < 0.05). While in the diet group, MCP-1 and IL-8 exhibited significantly decreased levels (p < 0.05). In the diet-exercise group, a positive correlation between the atherogenic index and waist circumference was found (r = 0.822, p = 0.011), and a negative correlation was observed between the delta of ASC mRNA expression and IL-10 levels at the end of the intervention (r = - 0.627, p = 0.019). CONCLUSION: Low-grade chronic inflammation was attenuated through individualized exercise prescription and our findings highlight the role of the ASC gene in the inflammation of obese adults. TRIAL REGISTRATION: ClinicalTrials.gov , number NCT04315376 . Registered 20 March 2020-retrospectively registered.

9.
Reprod Domest Anim ; 55(9): 1180-1189, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32608107

RESUMO

Primiparous ewes and multiparous ewes show physiological differences during pregnancy, which can have an impact on the development of their offspring. The objective of this study was to compare the changes in the metabolic profile and in the size of some foetal bones throughout gestation between primiparous and multiparous ewes. Twelve primiparous (PM) ewes and 14 multiparous (MT) ewes were used. According to the dates of lambing, two groups of ewes were formed: Group 1 (G1, n = 6 PM and n = 7 MT) and Group 2 (G2, n = 6 PM and n = 7 MT). The body weight, body condition score, metabolic and foetal morphometric parameters were determined from before conception until the end of gestation. After lambing, the body weight and survival rate during the first 72 hr of life of lambs, as well as the maternal behaviour score were recorded. The PM ewes were lighter (p < .01) and had a greater mobilization of body reserves during gestation, mainly evidenced by a greater serum concentration of NEFAs and lower serum concentration of total proteins (p < .05) compared with the MT ewes. The parity did not affect the foetal morphometric variables. The lambs of MT ewes were heavier at parturition (p = .002) and tended to have a greater survival rate than those lambs of PM ewes (p = .09). In conclusion, PM ewes and MT ewes differ in their metabolic profile throughout the gestation. However, in the present study, we did not find parity differences in the dimensions of foetal bones during growth in gestation.


Assuntos
Osso e Ossos/embriologia , Paridade , Gravidez/metabolismo , Carneiro Doméstico/embriologia , Carneiro Doméstico/metabolismo , Animais , Animais Recém-Nascidos , Peso Corporal , Desenvolvimento Ósseo , Feminino , Desenvolvimento Fetal , Metaboloma , Gravidez/fisiologia
10.
Cytokine ; 130: 155085, 2020 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-32259772

RESUMO

BACKGROUND: Based on the crosstalk of inflammation with apoptosis, autophagy, and endoplasmic reticulum (ER) stress, the main objective of this study was to explore the role of interleukin-6 (IL-6) on genes and proteins related to these phenomena in the livers of mice submitted to acute exhaustive exercise. METHODS: Reverse transcription-quantitative polymerase chain reaction and immunoblotting technique were used to evaluate the livers of wild-type (WT) and IL-6 knockout (KO) mice at baseline (BL) and 3 h after the acute exhaustive physical exercise (EE). RESULTS: Compared to the WT at baseline, the IL-6 KO had lower exhaustion velocity, mRNA levels of Mtor, Ulk1, Map1lc3b, and Mapk14, and protein contents of ATG5 and p-p70S6K/p70S6K. For the WT group, the EE decreased glycemia, mRNA levels of Casp3, Mtor, Ulk1, Foxo1a, Mapk14, and Ppargc1a, and protein contents of ATG5 and p-p70S6K/p70S6K, but increased mRNA levels of Sqstm1. For the IL-6 KO group, the EE decreased glycemia, mRNA levels of Casp3 and Foxo1a, and protein contents of pAkt/Akt and Mature/Pro IL-1beta, but increased mRNA levels of Sqstm1, and protein contents of p-AMPK/AMPK. CONCLUSION: The inhibition of the hepatic autophagy markers induced by the acute EE was attenuated in IL-6 KO mice, highlighting a new function of this cytokine.

11.
Nutrients ; 12(3)2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32121154

RESUMO

The present study verified the responses of proteins related to the autophagy pathway after 10 h of fast with resistance exercise and protein ingestion in skeletal muscle and liver samples. The rats were distributed into five experimental groups: control (CT; sedentary and without gavage after fast), exercise immediately (EXE-imm; after fast, rats were submitted to the resistance protocol and received water by gavage immediately after exercise), exercise after 1 h (EXE-1h; after fast, rats were submitted to the resistance protocol and received water by gavage 1 h after exercise), exercise and supplementation immediately after exercise (EXE/Suppl-imm; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage immediately after exercise), exercise and supplementation 1 h after exercise (EXE/Suppl-1h; after fast, rats were submitted to the resistance protocol and received a mix of casein: whey protein 1:1 (w/w) by gavage 1 h after exercise). In summary, the current findings show that the combination of fasting, acute resistance exercise, and protein blend ingestion (immediately or 1 h after the exercise stimulus) increased the serum levels of leucine, insulin, and glucose, as well as the autophagy protein contents in skeletal muscle, but decreased other proteins related to the autophagic pathway in the liver. These results deserve further mechanistic investigations since athletes are combining fasting with physical exercise to enhance health and performance outcomes.


Assuntos
Autofagia , Biomarcadores/metabolismo , Proteínas Alimentares/administração & dosagem , Jejum/fisiologia , Fígado/metabolismo , Músculo Esquelético/metabolismo , Condicionamento Físico Animal , Treinamento Resistido , Albuminas/metabolismo , Animais , Autofagia/efeitos dos fármacos , Autofagia/genética , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Proteínas Alimentares/farmacologia , Ingestão de Alimentos , Jejum/sangue , Regulação da Expressão Gênica/efeitos dos fármacos , Insulina/sangue , Leucina/sangue , Fígado/efeitos dos fármacos , Masculino , Músculo Esquelético/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Triglicerídeos/sangue
12.
EMBO J ; 38(21): e102361, 2019 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-31613024

RESUMO

The E3 ubiquitin ligase RNF8 (RING finger protein 8) is a pivotal enzyme for DNA repair. However, RNF8 hyper-accumulation is tumour-promoting and positively correlates with genome instability, cancer cell invasion, metastasis and poor patient prognosis. Very little is known about the mechanisms regulating RNF8 homeostasis to preserve genome stability. Here, we identify the cellular machinery, composed of the p97/VCP ubiquitin-dependent unfoldase/segregase and the Ataxin 3 (ATX3) deubiquitinase, which together form a physical and functional complex with RNF8 to regulate its proteasome-dependent homeostasis under physiological conditions. Under genotoxic stress, when RNF8 is rapidly recruited to sites of DNA lesions, the p97-ATX3 machinery stimulates the extraction of RNF8 from chromatin to balance DNA repair pathway choice and promote cell survival after ionising radiation (IR). Inactivation of the p97-ATX3 complex affects the non-homologous end joining DNA repair pathway and hypersensitises human cancer cells to IR. We propose that the p97-ATX3 complex is the essential machinery for regulation of RNF8 homeostasis under both physiological and genotoxic conditions and that targeting ATX3 may be a promising strategy to radio-sensitise BRCA-deficient cancers.


Assuntos
Adenosina Trifosfatases/metabolismo , Ataxina-3/metabolismo , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , Homeostase , Proteínas Nucleares/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina/metabolismo , Adenosina Trifosfatases/genética , Ataxina-3/genética , Sobrevivência Celular , Cromatina/genética , Proteínas de Ligação a DNA/genética , Instabilidade Genômica , Células HEK293 , Células HeLa , Humanos , Proteínas Nucleares/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Transdução de Sinais , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
13.
Lifestyle Genom ; 12(1-6): 25-44, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31546245

RESUMO

BACKGROUND: Chronic diseases arise as a consequence of an unhealthy lifestyle primarily characterized by physical inactivity and unbalanced diets. Regular physical activity can improve health, and there is consistent evidence that these improvements may be the result of epigenetic modifications. OBJECTIVE: To identify epigenetic modificationsas outcomes of exercise interventions related to specific metabolic alterations. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) methodology for manuscript research and preparation was followed using PubMed and EBSCO databases for literature review. Out of 2,638 articles identified, only 34 articles met the inclusion criteria. RESULTS: The sections of the review were organized by metabolic alterations in which studies were grouped according to healthy, diseased, and trained individuals. Resistance exercise in humans induced epigenetic changes in pathways associated with energy metabolism and insulin sensitivity, contributing to healthy skeletal muscle. Endurance exercise also caused modifications in biomarkers associated to metabolic alterations through changes in DNA methylation and the expression of specific miRNAs. However, both resistance and endurance exercise are necessary to obtain a better physiological adaptation and a combination of both seems to be needed to properly tackle the increasing prevalence of non-communicable pathologies. CONCLUSION: Given the heterogeneity and complexity of the existing literature, it is currently not possible to propose a specific recommendation about the type, intensity, or duration of exercise that could be beneficial for different subsets of the population (healthy, diseased, and/or trained). Nevertheless, this review highlights the importance of exercise for health and shows the need to perform more research in this emerging area to identify epigenetic biomarkers that could serve as indicators of exercise adaptations.


Assuntos
Biomarcadores , Metabolismo Energético/genética , Epigênese Genética/fisiologia , Terapia por Exercício , Doenças Metabólicas/diagnóstico , Doenças Metabólicas/terapia , Biomarcadores/análise , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/terapia , Metilação de DNA/fisiologia , Exercício Físico/fisiologia , Interação Gene-Ambiente , Humanos , Estilo de Vida , Doenças Metabólicas/genética , Prognóstico , Comportamento Sedentário , Resultado do Tratamento
14.
Cancers (Basel) ; 11(8)2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31362447

RESUMO

: Claspin is essential for activating the DNA damage checkpoint effector kinase Chk1, a target in oncotherapy. Claspin functions are tightly correlated to Claspin protein stability, regulated by ubiquitin-dependent proteasomal degradation. Here we identify Glycogen Synthase Kinase 3-ß (GSK3-ß) as a new regulator of Claspin stability. Interestingly, as Chk1, GSK3-ß is a therapeutic target in cancer. GSK3-ß inhibition or knockdown stabilizes Claspin, whereas a GSK3-ß constitutively active form reduces Claspin protein levels by ubiquitination and proteasome-mediated degradation. Our results also suggest that GSK3-ß modulates the interaction of Claspin with ß-TrCP, a critical E3 ubiquitin ligase that regulates Claspin stability. Importantly, GSK3-ß knock down increases Chk1 activation in response to DNA damage in a Claspin-dependent manner. Therefore, Chk1 activation could be a pro-survival mechanism that becomes activated upon GSK3-ß inhibition. Importantly, treating triple negative breast cancer cell lines with Chk1 or GSK3-ß inhibitors alone or in combination, demonstrates that Chk1/GSK3-ß double inhibition restrains cell growth and triggers more apoptosis compared to individual treatments, thereby revealing novel possibilities for a combination therapy for cancer.

15.
FEBS J ; 286(3): 441-455, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29931808

RESUMO

Claspin was discovered as a Chk1-interacting protein necessary for Chk1 phosphorylation and activation by the upstream kinase, ATR, in response to DNA synthesis inhibition in Xenopus oocyte extracts. Subsequent investigations have defined a molecular model in which Claspin acts as an adaptor or scaffold protein to facilitate activation of Chk1 by ATR within a multiprotein complex that forms on single-stranded DNA at stalled replication forks and sites of DNA damage. Interestingly, Claspin is an unstable protein whose degradation via the proteasome is tightly regulated via ubiquitination and controlled by multiple ubiquitin ligases and deubiquitinases. As a result, Claspin levels fluctuate during the cell cycle, contributing to the regulation of checkpoint proficiency and playing a key role in terminating checkpoint-mediated cell cycle arrest. In addition to its role in signalling genotoxic stress, Claspin is required to maintain normal rates of replication fork progression during unperturbed DNA replication and may contribute to the regulation of replication origin firing. Consistent with this, Claspin can bind directly to DNA, with particular affinity for branched or forked molecules, and it interacts with multiple protein components of the replisome. As expected for a protein with key roles in checkpoint signalling and genome duplication, aberrations of Claspin expression and structure have been observed in cancer. Claspin is furthermore targeted to facilitate viral replication and plays a role in suppressing cellular DNA synthesis in response to nongenotoxic endoplasmic reticulum stress. Here, we review the functions and regulation of Claspin with a focus on areas of active research.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Ciclo Celular/genética , Replicação do DNA , Regulação Neoplásica da Expressão Gênica , Neoplasias/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Quinase 1 do Ponto de Checagem/genética , Quinase 1 do Ponto de Checagem/metabolismo , Quebras de DNA de Cadeia Simples , DNA de Cadeia Simples , Genoma Humano , Instabilidade Genômica , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Transdução de Sinais , Ubiquitinação , Xenopus laevis/genética , Xenopus laevis/crescimento & desenvolvimento , Xenopus laevis/metabolismo
16.
Cells ; 7(10)2018 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-30241373

RESUMO

Eukaryotic cells divide by accomplishing a program of events in which the replication of the genome is a fundamental part. To ensure all cells have an accurate copy of the genome, DNA replication occurs only once per cell cycle and is controlled by numerous pathways. A key step in this process is the initiation of DNA replication in which certain regions of DNA are marked as competent to replicate. Moreover, initiation of DNA replication needs to be coordinated with other cell cycle processes. At the molecular level, initiation of DNA replication relies, among other mechanisms, upon post-translational modifications, including the conjugation and hydrolysis of ubiquitin. An example is the precise control of the levels of the DNA replication initiation protein Cdt1 and its inhibitor Geminin by ubiquitin-mediated proteasomal degradation. This control ensures that DNA replication occurs with the right timing during the cell cycle, thereby avoiding re-replication events. Here, we review the events that involve ubiquitin signalling during DNA replication initiation, and how they are linked to human disease.

17.
Obes Facts ; 11(4): 344-353, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30092569

RESUMO

OBJECTIVE: The aim of this study was to analyze dietary ω-6:ω-3 polyunsaturated fatty acid (PUFA) ratio and its association with adiposity and serum adiponectin levels in a Mexican population. METHODS: In this cross-sectional study, individuals with a BMI ≥ 18.5 kg/m2, were classified using four methods to measure adiposity. Parameters of body composition were measured by InBody 3.0. Diet intake was evaluated prospectively using a 3-day written food record. Serum high-molecular weight adiponectin isoform was measured using an ELISA assay. Biochemical and adiposity variables were analyzed by tertiles of dietary ω-6:ω-3 PUFA ratio. RESULTS: A total of 170 subjects were recruited with a mean age of 36.9 ± 11.8 years. The 73.5% of subjects were women. Subjects in the higher tertile of dietary ω-6:ω-3 PUFA ratio had more adiposity and higher levels of triglycerides, VLDL-c, glucose, insulin and HOMA-IR than those in the first tertile (p < 0.05). Adiponectin levels showed a trend according to dietary ω-6:ω-3 PUFA ratio (p = 0.06). A linear regression model showed that waist circumference, insulin, and HOMA-IR have positive associations with dietary ω-6:ω-3 PUFA ratio. CONCLUSION: This study suggests that high dietary ω-6:ω-3 PUFA ratio is positively associated with excessive adiposity and worse metabolic profile.


Assuntos
Adiposidade , Dieta , Gorduras na Dieta/administração & dosagem , Ácidos Graxos Ômega-3/administração & dosagem , Comportamento Alimentar , Obesidade/epidemiologia , Circunferência da Cintura , Adiposidade/efeitos dos fármacos , Adiposidade/fisiologia , Adolescente , Adulto , Idoso , Composição Corporal/efeitos dos fármacos , Estudos Transversais , Gorduras na Dieta/farmacologia , Suplementos Nutricionais , Feminino , Humanos , Insulina/sangue , Resistência à Insulina , Lipídeos/sangue , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/metabolismo , Triglicerídeos/sangue , Circunferência da Cintura/efeitos dos fármacos , Adulto Jovem
18.
J Int Med Res ; 46(4): 1467-1476, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29338565

RESUMO

Objective Mexico has one of the world's highest rates of obesity, which is influenced by lipid-genetic and lifestyle factors. This study aimed to determine whether FABP2 (Ala54Thr) and MTTP (-493 G/T) genetic polymorphisms are associated with metabolic disorders in Mexican subjects. Methods A total of 523 subjects participated in a cross-sectional study. Genotyping for FABP2 and MTTP was performed using real-time RT-PCR. Biochemical and anthropometric data were evaluated. Results The genetically at-risk group (Thr54/-493T) was associated with significantly higher total and low-density lipoprotein cholesterol levels (difference between genetically at-risk group and wild-type group: 10.6 mg/dL and 8.94 mg/dL, respectively). Carriers within the genetically at-risk group had a significantly higher prevalence rate of hypercholesterolaemia (42.5% vs. 32.0%) and higher LDL-C levels (37.6% vs. 26.4%) than did non-carriers. Conclusions Subjects who are genetically at risk (Thr54/-493T) have higher total cholesterol levels, low-density lipoprotein cholesterol levels, and prevalence rate of hypercholesterolaemia. These findings highlight the importance of basing nutritional intervention strategies for preventing and treating chronic diseases on individual genetic characteristics.


Assuntos
Colesterol/metabolismo , Proteínas de Ligação a Ácido Graxo/genética , Estudos de Associação Genética , Lipoproteínas LDL/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Adulto , Demografia , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Doenças Metabólicas/genética , México , Grupos Raciais/genética , Fatores de Risco
19.
Mol Oncol ; 10(8): 1196-206, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27296872

RESUMO

DNA replication control is a key process in maintaining genomic integrity. Monitoring DNA replication initiation is particularly important as it needs to be coordinated with other cellular events and should occur only once per cell cycle. Crucial players in the initiation of DNA replication are the ORC protein complex, marking the origin of replication, and the Cdt1 and Cdc6 proteins, that license these origins to replicate by recruiting the MCM2-7 helicase. To accurately achieve its functions, Cdt1 is tightly regulated. Cdt1 levels are high from metaphase and during G1 and low in S/G2 phases of the cell cycle. This control is achieved, among other processes, by ubiquitination and proteasomal degradation. In an overexpression screen for Cdt1 deubiquitinating enzymes, we isolated USP37, to date the first ubiquitin hydrolase controlling Cdt1. USP37 overexpression stabilizes Cdt1, most likely a phosphorylated form of the protein. In contrast, USP37 knock down destabilizes Cdt1, predominantly during G1 and G1/S phases of the cell cycle. USP37 interacts with Cdt1 and is able to de-ubiquitinate Cdt1 in vivo and, USP37 is able to regulate the loading of MCM complexes onto the chromatin. In addition, downregulation of USP37 reduces DNA replication fork speed. Taken together, here we show that the deubiquitinase USP37 plays an important role in the regulation of DNA replication. Whether this is achieved via Cdt1, a central protein in this process, which we have shown to be stabilized by USP37, or via additional factors, remains to be tested.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Replicação do DNA , Endopeptidases/metabolismo , Ubiquitinação , Linhagem Celular , Fase G1 , Humanos , Fosforilação , Ligação Proteica , Fase S
20.
Rev. cuba. hematol. inmunol. hemoter ; 31(1): 41-52, ene.-mar. 2015.
Artigo em Espanhol | CUMED | ID: cum-66926

RESUMO

Introducción: el control médico del entrenamiento deportivo lleva implícita la medición de parámetros hematológicos y de los índices eritrocitarios, incluido el conteo de reticulocitos, además de controles bioquímicos para velar por el estado de salud del deportista y obtener mejores resultados deportivos.Objetivo: analizar el comportamiento de las variables de los estudios hematológicos realizados a los deportistas de las preselecciones que participaron en los juegos Panamericanos Guadalajara 2011.Método: se realizó un estudio descriptivo transversal que tuvo como universo a 804 deportistas de alto nivel que integraban las preselecciones nacionales que se preparaban para constituir los equipos nacionales que participarían en los Juegos Panamericanos en Guadalajara, México, 2011. A todos se les realizó el perfil hematológico como parte del pasaporte biológico establecido para este tipo de competición. Además, a 328 se les realizó electroforesis de hemoglobina.Resultados: se encontraron cifras de hemoglobina y hematocrito significativamente más bajas en el sexo femenino. La concentración de hemoglobina corpuscular media presentó diferencias significativas por grupo de deporte. En los deportistas a quienes se les realizó electroforesis de hemoglobina se encontraron 15 AS.Conclusiones: los hallazgos de esta investigación son de gran utilidad para el diagnóstico y seguimiento de la salud de los deportistas de alto rendimiento sometidos a fuertes cargas físicas de trabajo(AU)


Introduction: medical management of sports training implies the measurement of hematological parameters, red cell indices, reticulocyte count and biochemical controls to care for the athletes´ health condition and to obtain higher sports scores. Objective: to analyze the behavior of the variables in hematological studies of athletes who participated in the presets Pan American Games Guadalajara 2011. Methods: a descriptive cross-sectional study was carried out with a universe of 804 high-performance athletes from national teams, who were training to participate in the Pan American Games in Guadalajara, Mexico, 2011. Hematological profile was performed as part of the biological passport established for this type of competition. Additionally, a hemoglobin electrophoresis was carried out in 328 of them. Results: significantly lower hemoglobin and hematocrit figures were found in females. The Mean Corpuscular Hemoglobin Concentration (MCHC) showed significant differences by group of sports. In athletes who underwent electrophoresis, Hb 15 AS were found. Conclusions: the findings of this research are useful for diagnosis and health monitoring of athletes of high-performance, under heavy physical workloads.


Assuntos
Humanos , Biometria/métodos , Testes Hematológicos/métodos , Atletas , Epidemiologia Descritiva , Estudos Transversais
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