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1.
BMJ Open ; 14(7): e081853, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38969368

RESUMO

INTRODUCTION: Work-related musculoskeletal disorders (WMSDs) are disorders of the musculoskeletal system that have the highest prevalence among workers worldwide. Workers in gas stations usually work in poor ergonomic working conditions, including prolonged standing and repetitive posturing. OBJECTIVE: The study aimed to investigate the prevalence of WMSDs and fatigue and to identify the predictors of WMSDs among gas station workers. DESIGN: The present study was a cross-sectional study. SETTING AND PARTICIPANTS: 2962 gas station workers from an oil and gas company in China, with ages ranging from 17 to 75 years old, 55.47% female. RESULTS: The prevalence of WMSDs within the 12 months prior to the study was 73.23%, with the highest prevalence in the neck, shoulders, ankles and feet. Furthermore, a correlation was observed between fatigue, stress and WMSDs. Fatigue and job role were the strongest predictors of WMSDs, with an OR range of 2.211-3.413. CONCLUSIONS: This research identified the detrimental impact of WMSDs and fatigue on gas station workers, indicating the critical need for interventions to reduce WMSDs and relieve fatigue.


Assuntos
Fadiga , Doenças Musculoesqueléticas , Doenças Profissionais , Humanos , Estudos Transversais , Feminino , Adulto , China/epidemiologia , Masculino , Pessoa de Meia-Idade , Fadiga/epidemiologia , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Adulto Jovem , Doenças Musculoesqueléticas/epidemiologia , Doenças Musculoesqueléticas/etiologia , Prevalência , Adolescente , Idoso , Estresse Ocupacional/epidemiologia , Indústria de Petróleo e Gás
2.
Behav Sci (Basel) ; 14(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38247684

RESUMO

Tech giants are large, well-known internet and technology companies. Employees of such companies are generally expected to work fast and for long periods of time, causing them to experience high occupational fatigue. The relationship between occupational fatigue and well-being is complex. Furthermore, in the context of the workplace, unhealthy eating behaviour may be used as a mechanism to cope with fatigue and stress. This study explored the relationship between occupational fatigue, well-being and unhealthy eating behaviour within this specific professional population. Study 1 used qualitative research methods, in which in-depth interviews were conducted with staff working at 13 tech giants in Shenzhen, China (N = 50). The findings revealed that work-related stress and occupational fatigue are common among employees working for tech giants. Additionally, factors such as unhealthy eating behaviour, workload, working hours and workplace interpersonal relationships were found to influence occupational well-being. Study 2 involved a cross-sessional survey of 237 employees of tech giants. The results indicated that occupational fatigue negatively impacts occupational well-being and that unhealthy eating behaviours play a moderating role between occupational fatigue and occupational well-being. These findings highlight the significance of adopting appropriate measures to improve the situation and cope with the effects of occupational fatigue by managing unhealthy eating behaviours.

3.
Behav Sci (Basel) ; 14(1)2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38247717

RESUMO

Logistics personnel in Chinese universities are facing unbalanced costs and benefit from overloaded work with minimum wages, which impede school development and their well-being. However, the logistics staff population has been neglected in past investigations pertaining to psychological health conditions. The present study aimed to examine the positive well-being, work-related rumination, and work engagement of logistics staff, their correlations, and the factors affecting well-being in 282 Chinese university logistics staff via the Smith Well-being Questionnaire, the Work-Related Rumination Questionnaire, and the Utrecht Work Engagement Scale. The results indicated low levels of well-being and high levels of work-related rumination and work engagement among Chinese university logistics staff. The presence of positive attitudes towards life and work and high levels of work engagement predicts enhanced well-being, while the presence of negative characteristics and work-related rumination predicts decreased well-being. In situations where the working hours and work duties are challenging to change, universities can regularly schedule psychological counselling sessions for logistics staff to improve their well-being.

4.
Work ; 76(2): 707-726, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36938763

RESUMO

BACKGROUND: Occupational health factors such as shift work, sleep, fatigue, and work environment jeopardise the health and safety of gas station workers. This calls for new research to investigate how the working environment and characteristics impact the occupational health of workers at gas stations. However, minimal research has been conducted in this field, especially those involving psychological and behavioural factors, occupational stress, and so forth. OBJECTIVE: This review was performed to investigate the present condition of the occupational risk of gas station workers in this safety-critical position. METHODS: Five databases (Web of Science, ScienceDirect, PubMed, Google Scholar, and PsycINFO) were searched for relevant peer-reviewed studies. Results were selected according to these criteria: studies on fatigue, shift work, sleep, and physical and mental health of gas station employees; published on or before November 11, 2021; papers in English. RESULTS: Twenty studies were considered for the final analysis. The results showed that shift work at gas stations leads to psychological and physiological problems. The psychological consequences included anxiety, stress, and depression, while the physiological consequences included biochemical changes and lifestyle consequences. CONCLUSION: Shift work and the specific working environment of gas station employees adversely affect their sleep, stress levels, physical and mental health, and turnover intention. This systematic review allowed us to consider the occupational risk factors that can lead to sickness or accidents and contribute to reducing these risk factors. Realistic countermeasures ought to be established and interventions must be explored to mitigate risks to life, property, and the environment in operating gas stations.


Assuntos
Saúde Ocupacional , Estresse Ocupacional , Humanos , Saúde Mental , Sono , Fadiga/etiologia
5.
Int J Mol Sci ; 24(3)2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36768942

RESUMO

Vibrio parahaemolyticus is a moderately halophilic foodborne pathogen that is mainly distributed in marine and freshwater environments. The transition of V. parahaemolyticus between aquatic ecosystems and hosts is essential for infection. Both freshwater and host environments have low salinity. In this study, we sought to further investigate the effects of low salinity (0.5% NaCl) on the fitness and virulence of V. parahaemolyticus. We found that V. parahaemolyticus could survive in Luria-Bertani (LB) and M9 mediums with different NaCl concentrations, except for the M9 medium containing 9% NaCl. Our results further showed that V. parahaemolyticus cultured in M9 medium with 0.5% NaCl had a higher cell density than that cultured at other NaCl concentrations when it entered the stationary phase. Therefore, we compared the transcriptomes of V. parahaemolyticus wild type (WT) cultured in an M9 medium with 0.5% and 3% NaCl at the stationary phase using RNA-seq. A total of 658 genes were significantly differentially expressed in the M9 medium with 0.5% NaCl, including regulators, osmotic adaptive responses (compatible solute synthesis systems, transporters, and outer membrane proteins), and virulence factors (T3SS1 and T6SS1). Furthermore, a low salinity concentration in the M9 medium induced the expression of T3SS1 to mediate the cytotoxicity of V. parahaemolyticus to HeLa cells. Similarly, low salinity could also induce the secretion of the T3SS2 translocon protein VPA1361. These factors may result in the high pathogenicity of V. parahaemolyticus in low-salinity environments. Taken together, these results suggest that low salinity (0.5% NaCl) could affect gene expression to mediate fitness and virulence, which may contribute to the transition of V. parahaemolyticus between aquatic ecosystems and the host.


Assuntos
Vibrio parahaemolyticus , Humanos , Vibrio parahaemolyticus/metabolismo , Sistemas de Secreção Tipo III/metabolismo , Cloreto de Sódio/farmacologia , Cloreto de Sódio/metabolismo , Células HeLa , Pressão Osmótica , Ecossistema , Perfilação da Expressão Gênica , Proteínas de Bactérias/metabolismo
6.
J Appl Toxicol ; 42(4): 660-670, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34716709

RESUMO

Zearalenone (ZEA) is one of the most major food contaminants in cereal crops worldwide, risking health of both livestock and humans. This study aimed to assess the cytotoxicity and the underlying mechanism of ZEA on thymic epithelial cells. By using proteomics analysis, we identified 596 differentially expressed proteins in MTEC1 cells upon zearalenone exposure, of which 245 were upregulated and 351 were downregulated. Gene ontology (GO) analysis suggested that differentially expressed proteins were participated in protein synthesis, oxidative phosphorylation, and ATP binding. KEGG pathway enrichment analysis showed that differentially expressed proteins were mainly related to mitochndrial metabolism, such as citrate cycle (TCA cycle) and oxidative phosphorylation. We demonstrated that ZEA treatment was able to increase the intracellular reactive oxygen species (ROS) level, to decrease ΔΨm, ATP level, and the copy number of mtDNA, leading to necrotic cell death. Moreover, we showed that ZEA treatment inhibited cell proliferation and induced G2/M phase arrest by downregulation of proliferation-associated proteins ERK, p-ERK, CDK1, and p-CHK1. Taken together, we found that the toxicity of ZEA on thymic epithelial cells is mainly caused by the inhibition of mitochondrial dysfunction and cell proliferation. Our study might open new avenues for treatment strategies.


Assuntos
Zearalenona , Trifosfato de Adenosina/metabolismo , Animais , Células Epiteliais/metabolismo , Camundongos , Proteômica , Espécies Reativas de Oxigênio/metabolismo , Zearalenona/toxicidade
8.
Ecotoxicol Environ Saf ; 153: 135-141, 2018 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-29425844

RESUMO

Zearalenone (ZEA) was a mycotoxin biosynthesized by a variety of Fusarium fungi via a polypeptide pathway. ZEA has significant toxic reaction on immune cells. Thymic epithelial cells (TECs) as a crucial constituent of thymic stroma can provide unique microenvironment for thymocyte maturation, but the mechanism of ZEA affecting the TECs is poorly understood. The basic data about gene expression differences for the ZEA on thymic epithelial cell line 1 (MTEC1) will help us to elucidate this mechanism. Here, cell viability and proliferation assay and transcriptome sequencing on MTEC1 treated with ZEA were performed. 4188 differentially expressed genes (DEGs) between ZEA treated and control groups were identified, confirmed and analyzed. Our results showed that 10-50µg/ml ZEA significantly inhibited MTEC1 proliferation and arrested cell cycle at G2/M phase. Gene ontology and KEGG pathway analysis revealed that Chemokine, JAK-STAT and Toll-like receptor signaling pathway, were involved in the cell cycle pathway. 16 key genes involved in the cell cycle processes were validated and the results suggested that Mitotic catastrophe (MC) may take part in ZEA inhibition of METC1 cell proliferation. These data highlighted the importance of cell cycle pathway in MTEC1 treated with ZEA, and will contribute to get the molecular mechanisms of ZEA inhibition of MTEC1 cell proliferation.


Assuntos
Proliferação de Células/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Timo/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Zearalenona/toxicidade , Animais , Técnicas de Cultura de Células , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , Timo/patologia
9.
BMJ Case Rep ; 20172017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29237666

RESUMO

Spigelian hernias are a rare lateral ventral abdominal hernia that carry a high risk of strangulation due to their smaller sizes, and require surgical intervention. In more complex cases involving an anticoagulated patient, perioperative management of anticoagulation must be monitored and reviewed to avoid potential pitfalls. We present an 81-year-old woman who presented with right groin pain, and was requiring warfarin anticoagulation due to her cardiac history. The spigelian hernia was diagnosed and reduced laparoscopically, and the defect was repaired and reinforced by mesh. However, the patient suffered from catastrophic complications postoperatively related to her anticoagulation management. Spigelian hernias require surgical interventions. However, in an anticoagulated patient with significant comorbidities, perioperative anticoagulation needs to be closely monitored to balance the risk of thromboembolic disease with acceptable postoperative bleeding risks.


Assuntos
Anticoagulantes/efeitos adversos , Enoxaparina/efeitos adversos , Hematoma/diagnóstico , Hérnia Ventral/cirurgia , Hemorragia Pós-Operatória/diagnóstico , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Evolução Fatal , Feminino , Hematoma/induzido quimicamente , Hérnia Ventral/complicações , Humanos , Laparoscopia , Dor/etiologia , Hemorragia Pós-Operatória/induzido quimicamente , Telas Cirúrgicas
10.
Acta Biochim Biophys Sin (Shanghai) ; 49(5): 409-419, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28369179

RESUMO

The gender-biased thymus involution and the importance of microRNAs (miRNAs, miRs) expression in modulating the thymus development have been reported in many studies. However, how males and females differ in so many ways in thymus involution remains unclear. To address this question, we investigated the miRNA expression profiles in both untreated 3- and 12-month-old female and male mice thymuses. The results showed that 7 and 18 miRNAs were defined as the sex- and age-specific miRNAs, respectively. The expression of miR-181c-5p, miR-20b-5p, miR-98b-5p, miR-329-3p, miR-341-5p, and miR-2137 showed significant age-difference in mice thymus by quantitative polymerase chain reaction. High expression levels of miR-2137 were detected in mice thymic epithelial cells and gradually increased during the process of thymus aging. MiR-27b-3p and miR-378a-3p of the female-biased miRNAs were confirmed as the sex- and estrogen-responsive miRNAs in mice thymus in vivo. Their potential target genes and the pathway were identified by the online software. Possible regulation roles of sex- and age-specific miRNA expression during the process of thymus aging were discussed. Our results suggested that these miRNAs may be potential biomarkers for the study of sex- and age-specific thymus aging and involution.


Assuntos
Envelhecimento/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , MicroRNAs/metabolismo , Caracteres Sexuais , Timo/metabolismo , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C
11.
Environ Toxicol ; 32(4): 1170-1182, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27404259

RESUMO

In view of the extensive use of nanoparticles in countless applications, a fast and effective method for assessing their potential adverse effects on the environment and human health is extremely important. At present, in vitro cell-based assays are the standard approach for screening chemicals for cytotoxicity because of their relative simplicity, sensitivity, and cost-effectiveness compared with animal studies. Regrettably, such cell-based viability assays encounter limitations when applied to determining the biological toxicity of nanomaterials, which often interact with assay components and produce unreliable outcomes. We have established a cell-impedance-based, label-free, real-time cell-monitoring platform suitable for use in a variety of mammalian cell lines that displays results as cell index values. In addition to this real-time screening platform, other traditional cytotoxicity assays were employed to validate cytotoxicity assessments. We suggest that the cell impedance measurement approach is effective and better suited to determining the cytotoxicity of nanomaterials for environmental safety screening. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1170-1182, 2017.


Assuntos
Nanopartículas Metálicas/toxicidade , Células A549 , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Teste de Materiais , Camundongos , Células NIH 3T3 , Estresse Oxidativo , Tamanho da Partícula
12.
Acta Biochim Biophys Sin (Shanghai) ; 48(11): 1034-1041, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27742678

RESUMO

MicroRNAs are highly conserved non-coding small RNAs participating in almost all kinds of biological activities. MiR-181a has been reported to be involved in the differentiation of porcine primary preadipocytes, but the profound effect of miR-181a-5p on 3T3-L1 adipocyte differentiation and proliferation is still unclear. In this study, we found that supplementation of miR-181a-5p in 3T3-L1 cells significantly promoted the adipogenesis and inhibited cell proliferation with increased expression of adipogenic marker genes including peroxisome proliferator-activated receptor gamma (Pparγ), CCAAT/enhancer-binding protein alpha (C/ebpα), fatty acid-binding protein 4 (Fabp4), and Adiponectin, accompanied by an accumulation of lipid droplet, an increase of triglyceride content, and a decrease of cell proliferation. Furthermore, by using the luciferase assay, Smad7 and Tcf7l2, two important members of transforming growth factor-ß (TGFß) and Wnt signaling pathway, were proven to be the direct target genes of miR-181a-5p. Moreover, supplementation of miR-181a-5p in 3T3-L1 cells altered the expressions of proteins involved in the TGFß signaling pathway, such as TGFBR1, p-SMAD3, SMAD4, c-MYC, and p15. Taken together, these results indicate that miR-181a-5p promotes 3T3-L1 preadipocyte differentiation and adipogenesis through regulating TGFß/Smad and Wnt signaling pathway by directly targeting Smad7 and Tcf7l2.


Assuntos
Adipogenia/genética , MicroRNAs/fisiologia , Proteína Smad7/genética , Proteína 1 Semelhante ao Fator 7 de Transcrição/genética , Células 3T3-L1 , Adipócitos/citologia , Animais , Diferenciação Celular/fisiologia , Camundongos
13.
Biochem Biophys Res Commun ; 478(4): 1772-9, 2016 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-27613096

RESUMO

Chemotherapeutic agents can upregulate autophagy which contributes to the acquisition of chemoresistance and the recurrence of cancer. The involvement of hHR23A in chemoresistance is unknown. In this study, we provide evidence suggesting that hHR23A may regulate autophagy. Knockdown of hHR23A decreased cell growth and increased the resistance in A549 cells to the DNA-damaging agents, cisplatin and oxaliplatin. Measurement of EGFP-LC3 puncta (a marker of autophagy) revealed that autophagy was increased in hHR23A-depleted cells. This effect was augmented by exposure to cisplatin or oxaliplatin. In contrast, the overexpression of hHR23A reversed the levels of autophagy-related proteins to control levels in hHR23A-knockdown cells. Moreover, we observed direct interactions among hHR23A, Beclin 1, and LC3. Finally, 3-methyladenine (3-MA)-induced inhibition of autophagy was found to reverse the sensitivity of hHR23A-knockdown cells to the tested DNA-damaging agents. These results collectively indicated that hHR23A-depleted cells exhibit enhanced autophagy when treated with DNA-damaging agents, perhaps suggesting a basis for the involvement of hHR23A in the acquired chemoresistance of cancer cells. Our study thus reveals a previously unrecognized autophagic function for hHR23A and suggests that it could be a potential therapeutic target for chemosensitizing resistant cancer cells.


Assuntos
Autofagia/efeitos dos fármacos , Cisplatino/farmacologia , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Compostos Organoplatínicos/farmacologia , Células A549 , Adenina/análogos & derivados , Adenina/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Autofagia/genética , Proteína Beclina-1/metabolismo , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Citometria de Fluxo , Humanos , Immunoblotting , Microscopia Confocal , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Oxaliplatina , Ligação Proteica , Interferência de RNA
14.
Acta Biochim Biophys Sin (Shanghai) ; 48(9): 840-9, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27411504

RESUMO

The expression profiles of miRNAs in thymus tissues from mice of different age have been demonstrated in our previous study. After an integrated analysis of the miRNA expression profiles, we demonstrated that the expression of miR-181a-5p was significantly decreased in thymic epithelial cells (TECs) from 10- to 19-month-old mice when compared with that in TECs from 1-month-old mice by quantitative reverse transcriptase polymerase chain reaction. We hypothesized that miR-181a-5p in TECs might be associated with the age-related thymus involution through regulating some genes or signaling pathway. To test this hypothesis, the mouse medullary thymic epithelial cells (MTEC1) were used. Transfection with miR-181a-5p mimic promoted the proliferation of MTEC1 cells, but did not affect apoptosis. The effect was reversed when the expression of miR-181a-5p was suppressed in MTEC1 cells. Furthermore, the transforming growth factor beta receptor I (Tgfbr1) was confirmed as a direct target of miR-181a-5p by luciferase assay. Moreover, it was found that overexpression of miR-181a-5p down-regulated the phosphorylation of Smad3 and blocked the activation of the transforming growth factor beta signaling. Nevertheless, an inversely correlation was observed between the expression of Tgfbr1 and miR-181a-5p in TECs derived from mice of different age. Collectively, we provide evidence that miR-181a-5p may be an important endogenous regulator in the proliferation of TECs, and the expression levels of miR-181a-5p in TECs may be associated with the age-related thymus involution.


Assuntos
MicroRNAs/genética , Timo/citologia , Timo/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Linhagem Celular , Proliferação de Células/genética , Proliferação de Células/fisiologia , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Regulação para Baixo , Células Epiteliais/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Transdução de Sinais/genética , Proteína Smad3/genética , Proteína Smad3/metabolismo , Transcriptoma
15.
Acta Biochim Biophys Sin (Shanghai) ; 48(3): 290-7, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26837421

RESUMO

MiR-195 has been implicated in inhibiting cell proliferation in different types of tumors. Whether it contributes to the process of thymic epithelial cells (TECs) proliferation remains unclear. In this study, we found that miR-195a-5p was highly up-regulated in the TECs isolated from the aging mice. Further experiments showed that miR-195a-5p mimic transfection inhibited the proliferation of mouse medullary thymic epithelial cell line 1 (MTEC1), whereas the transfection of miR-195a-5p inhibitor in MTEC1 had the opposite effect. In addition, miR-195a-5p had no obvious effect on MTEC1 apoptosis. Furthermore, Smad7, a negative regulator of transforming growth factor ß pathway, was confirmed as a direct target of miR-195a-5p by luciferase assays. Taken together, our results indicate that miR-195a-5p inhibits MTEC1 proliferation, at least in part, via down-regulation of Smad7.


Assuntos
Proliferação de Células/fisiologia , MicroRNAs/fisiologia , Proteína Smad7/metabolismo , Timo/citologia , Animais , Apoptose , Células Epiteliais/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , MicroRNAs/metabolismo , Timo/metabolismo
16.
Cell Signal ; 27(11): 2304-13, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26296656

RESUMO

Among other functions, the Chk1 protein plays an essential role in coordinating the cellular stress response by determining cell cycle arrest. The levels of Chk1 expression and activity are critical for its functions, especially in cell cycle progression, genomic integrity, cell viability and tissue development. Chk1 protein expression should therefore be tightly controlled both during normal growth and under stress situations. However, it is still unknown how Chk1 protein levels are regulated during normal cell cycle progression. In this study, we show that the effect of hHR23A on Chk1 protein turnover could impact the cell cycle progression observed in hHR23A-knockdown cells. Our results reveal that hHR23A associates with Chk1 through its UBA domains, and that knockdown of hHR23A increases and stabilizes the protein level of Chk1 and its phosphorylation at S347. Knockdown of hHR23A results in proliferation defects and S-phase accumulation. DNA damage reduces the interaction between Chk1 and hHR23A, releasing Chk1 from hHR23A and enhancing S-phase accumulation. Based on these novel findings, we propose that hHR23A acts as a carrier to promote Chk1 degradation through the Ubiquitin Proteasome System. These results strengthen the model in which DNA damage induces Chk1 phosphorylation on chromatin followed by releasing phospho-Chk1 from the chromatin into soluble nucleus and the cytoplasm where Chk1 activates the cell cycle checkpoints; and finally, Chk1 is degraded and checkpoint signaling is terminated.


Assuntos
Pontos de Checagem do Ciclo Celular/genética , Enzimas Reparadoras do DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas Quinases/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular , Quinase 1 do Ponto de Checagem , Dano ao DNA/genética , Replicação do DNA/genética , Humanos , Fosforilação/genética , Proteínas Quinases/genética , Estrutura Terciária de Proteína , Interferência de RNA , RNA Interferente Pequeno/genética , Fase S/genética , Transdução de Sinais
17.
Nutrients ; 7(5): 3200-18, 2015 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-25951128

RESUMO

Bear bile was used as a traditional medicine or tonic in East Asia, and ursodeoxycholic acid (UDCA) is the most important compound in bear bile. Further, synthetic UDCA is also used in modern medicine and nutrition; therefore, its further functional effects warrant research, in vitro methods could be used for the fundamental research of its anticancer effects. In this study, the apoptotic effects of UDCA in human oral squamous carcinoma HSC-3 cells through the activation of caspases were observed by the experimental methods of MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay, DAPI (4',6-diamidino-2-phenylindole) staining, flow cytometry analysis, RT-PCR (reverse transcription-polymerase chain reaction) assay and Western blot assay after HSC-3 cells were treated by different concentrations of UDCA. With 0 to 400 µg/mL UDCA treatment, UDCA had strong growth inhibitory effects in HSC-3 cells, but had almost no effect in HOK normal oral cells. At concentrations of 100, 200 and 400 µg/mL, UDCA could induce apoptosis compared to untreated control HSC-3 cells. Treatment of 400 µg/mL UDCA could induce more apoptotic cancer cells than 100 and 200 µg/mL treatment; the sub-G1 DNA content of 400 µg/mL UDCA treated cancer cells was 41.3% versus 10.6% (100 µg/mL) and 22.4% (200 µg/mL). After different concentrations of UDCA treatment, the mRNA and protein expressions of caspase-3, caspase-8, caspase-9, Bax, Fas/FasL (Fas ligand), TRAIL (TNF-related apoptosis-inducing ligand), DR4 (death receptor 4) and DR5 (death receptor 5) were increased in HSC-3 cells, and mRNA and protein expressions of Bcl-2 (B-cell lymphoma 2), Bcl-xL (B-cell lymphoma-extra large), XIAP (X-linked inhibitor of apoptosis protein), cIAP-1 (cellular inhibitor of apoptosis 1), cIAP-2 (cellular inhibitor of apoptosis 2) and survival were decreased. Meanwhile, at the highest concentration of 400 µg/mL, caspase-3, caspase-8, caspase-9, Bax, Fas/FasL, TRAIL, DR4, DR5, and IκB-α expression levels were the highest, and Bcl-2, Bcl-xL, XIAP, cIAP-1, cIAP-2, survival, and NF-κB expression levels were the lowest. These results proved that UDCA could induce apoptosis of HSC-3 cancer cells through caspase activation, and the higher concentration of UDCA had stronger effects in vitro. UDCA might be a good nutrient for oral cancer prevention.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/tratamento farmacológico , Caspases/metabolismo , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Ácido Ursodesoxicólico/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/enzimologia , Caspases/genética , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/enzimologia , Humanos , Proteínas Inibidoras de Apoptose/metabolismo , NF-kappa B/metabolismo , RNA Mensageiro/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço
18.
Acta Biochim Biophys Sin (Shanghai) ; 47(5): 355-61, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25918183

RESUMO

Previous evidence has indicated that the microRNA-125b (miR-125b) family plays important roles in the regulation of cancer cell growth, development, differentiation, and apoptosis. However, whether they contribute to the process of adipocyte differentiation remains unclear. In the present study, we revealed that the expression level of miR-125b-5p, a member of miR-125b family, was dramatically up-regulated during differentiation of 3T3-L1 preadipocyte into mature adipocyte. Supplement of miR-125b-5p into 3T3-L1 cells promoted adipogenic differentiation as evidenced by increased lipid droplets and mRNA levels of adipocyte-specific molecular markers, including peroxisome proliferators-activated receptor γ, CCAAT/enhancer-binding protein α, fatty acid-binding protein 4, and lipoprotein lipase, and by triglyceride accumulation. CCK-8 assay showed that miR-125b-5p supplementation significantly inhibited cell proliferation. Flow cytometry analysis showed that miR-125b-5p impaired G1/S phase transition as well as the mRNA and protein expression of G1/S-related genes, such as Cyclin D2, Cyclin D3, and CDK4. Nevertheless, it had no effect on apoptosis. Additionally, by target gene prediction, we demonstrated that smad4 may be a potential target of miR-125b-5p in mouse 3T3-L1 preadipocytes, accounting for some of miR-125b-5p's functions. Taken together, these data indicated that miR-125b-5p may serve as an important positive regulator in adipocyte differentiation, at least partially through down-regulating smad4.


Assuntos
Tecido Adiposo/citologia , Diferenciação Celular , Proliferação de Células , MicroRNAs/fisiologia , Células 3T3-L1 , Animais , Camundongos
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