ABSTRACT
Background N6-methyladenosine (m6A) RNA methylation may play an important role in the process of malignant transformation of cells induced by environmental carcinogens. However, the specific roles and mechanisms need to be further explored. Objective To explore the role and mechanism of m6A binding protein insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) in the malignant transformation of human gastric mucosal epithelial cells GES-1 induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Methods Based on the GES-1 malignant transformation cells MC-30, a stable knockdown IGF2BP3 MC-30 cell line (MC30-shIGF2BP3, abbreviated as MC30-shI3) was constructed by lentiviral transfection technology, and a negative control group (MC30-NC) was also prepared. Real-time quantitative polymerase chain reaction (qRT-PCR) and Western blotting were applied to detect the mRNA expression and protein levels of IGF2BP3. RNA binding protein immunoprecipitation (RIP-qPCR) was used to examine the combination between IGF2BP3 protein and MYC mRNA in malignant cells MC-30. Furthermore, the stability of MYC mRNA was detected by actinomycin D assay. CCK-8 and Transwell respectively were employed to detect cell proliferation, migration, and invasion. Western blotting was applied to detect the expression of EMT markers (N-cadherin, Vimentin, α-SMA, and Snail). The role of the downstream target gene MYC was further elucidated by a rescue assay in MC30-shI3 cells transfected with a plasmid overexpressing MYC to observe changes in cellular phenotypes (proliferation, migration, invasion) and expression of key EMT proteins. Results Compared with the control group, the expression of IGF2BP3 mRNA was up-regulated after 5, 10, 20, and 40 μmol·L−1 MNNG infection of GES-1 cells (P<0.05). After 20 μmol·L−1 MNNG infection, the expression level of IGF2BP3 mRNA increased with prolongation of exposure time (P<0.05). Compared with the control group, the mRNA and protein expression levels of IGF2BP3 were up-regulated in the 10th, 20th, and 30th generations of 5 μmol·L−1 MNNG malignant transformation (P<0.05). The results of qRT-PCR and Western blotting showed that, compared with the MC30-NC group, the IGF2BP3 and MYC mRNA expression and protein expression decreased in the MC30-shI3 group (P<0.01). The CCK8 and transwell assay results showed that, compared with the MC30-NC group, the cell proliferation, migration, and invasion abilities significantly reduced in the MC30-shI3 group (P<0.01). The results of the Western blotting showed that, compared with the MC30-NC group, the protein levels of EMT markers N-cadherin, Vimentin, α-SMA, and Snail decreased in the MC30-shI3 group (P<0.01). The results of RIP-qPCR showed that, compared with the IgG group, the mRNA level was higher for the enriched MYC in the IGF2BP3 group (P<0.01); the results of the actinomycin D assay showed that, compared with the MC30-NC group, the stability of MYC mRNA significantly reduced in the MC30-shI3 group (P<0.01). While the rescue experiment showed that, compared with the IGF2BP3 knock-down+vector group, the MYC protein level significantly increased in the IGF2BP3 knock-down + MYC over-expression group (P<0.01), the proliferation, migration, and invasion abilities significantly enhanced (P<0.01), and the EMT key proteins (N-cadherin, Vimentin, α-SMA, Snail) increased in the MC30-shI3+MYC group (P<0.01). Conclusion Exposure to MNNG could result in up-regulation of IGF2BP3 expression in GES-1 cells. IGF2BP3 may enhance the proliferation, migration, and invasion of malignantly transformed human gastric epithelial cells by binding to MYC mRNA and increasing its stability and expression level and thus promoting the EMT process, which in turn affects the progression of malignant transformation.
ABSTRACT
Background Occupational stress and depressive symptoms of disease prevention and control personnel are serious. Objective To investigate the relationship between occupational stress, psychological capital, and depressive symptoms of disease prevention and control personnel, and analyze the potential mediating effect of psychological capital on the relationship between occupational stress and depressive symptoms. Methods From July to September 2020, a cluster random sampling method was used to select 2201 employees from 21 centers for disease control and prevention as study subjects covering all levels of administrative divisions in Jiangsu Province. A total of 2036 valid questionnaires were collected with a recovery rate of 92.5%. The Core Occupational Stress Scale, Patient Health Questionnaire, and Psychological Capital Questionnaire were used to investigate their occupational stress, depressive symptoms, and psychological capital. Stratified regression analysis was used to explore the effects of occupational stress and psychological capital on depressive symptoms. A mediating effect model was used to analyze and verify the potential mediating effect of psychological capital on the relationship between occupational stress and depressive symptoms. Results The total scores in M (P25, P75) of occupational stress, depressive symptoms, and psychological capital in the target population were 42.0 (37.0, 48.0), 8.0 (4.0, 9.0), and 4.6 (4.0, 5.0) respectively. The positive rate of occupational stress was 31.0% (631/2036), and the positive rate of depressive symptoms was 22.0% (448/2036). The dimensional scores of organization and reward, and demand and effort of occupational stress were positively correlated with the total score of depressive symptoms [Spearman correlation coefficients (rs) were 0.371 and 0.269, P<0.05]. The dimensional scores of social support and autonomy of occupational stress and the score of psychological capital were negatively correlated with the total score of depressive symptoms (rs=−0.373, −0.112, −0.494, P<0.05). The organization and reward, and demand and effort had positive effects on depressive symptoms (b=0.188, 0.177, P<0.05), while social support and autonomy had negative effects on depressive symptoms (b=−0.290, −0.078, P<0.05), and associated with a 22.5% increase of explanatory variance. Psychological capital had a negative effect on depressive symptoms (b=−0.368, P<0.05), and associated with an 11.0% increase of explanatory variance. Psychological capital had mediating effects on the associations of social support, organization and reward, and autonomy with depressive symptoms, and the mediating effect values were −0.210 (95%CI: −0.253-−0.171), 0.096 (95%CI: 0.071-0.122), and −0.164 (95%CI: −0.229-−0.103), respectively. The corresponding mediating effect percentages were 40.23%, 26.97%, and 45.56%, respectively. Conclusion Occupational stress of disease prevention and control personnel can directly affect depressive symptoms, but also indirectly through psychological capital. Psychological capital plays a partial mediating role in the associations of social support, organization and reward, and autonomy of occupational stress with depressive symptoms. The occurrence of depressive symptoms can be reduced by decreasing occupational stress and increasing psychological capital.
ABSTRACT
Objective@#To investigate the benzene concentration in the workplace of benzene-related enterprises in Yangzhou City from 2014 to 2018, and the abnormal blood routine of workers exposed to benzene, and to assess their occupational hazards.@*Methods@#The environmental monitoring data of benzene-related enterprises and the health examination data of benzene exposed workers were collected in March 2019. The inhalation risk assessment model of the National Environmental Protection Agency (EPA) was used to assess the carcinogenic and non-carcinogenic risks of benzene workers.@*Results@#The qualified rate of benzene detection in the workplace was 100% from 2014 to 2018, the highest concentration was 1.42 mg/m3 in five years. The abnormal rates of blood routine detection in benzene exposed workers in five years was 7.10% (213/2 998) 、5.17% (218/4 214) 、5.61% (196/3 493) 、7.65% (288/3 767) 、7.83% (280/3 574) and 7.83%. respectively. The results of risk assessment showed that the minimum carcinogenic risk value was 7.56×10-6 and the maximum carcinogenic risk value was 31.33×10-6 in 2014-2018. The hazard quotient values were than 1.@*Conclusion@#Benzene monitoring concentration in benzene-related enterprises in Yangzhou City from 2014 to 2018 was low, which meets the occupational exposure limit in China. However, the abnormal rate of blood routine in five years is still high, and there are both carcinogenic and non-carcinogenic risks. We should pay more attention to the health risk of workers exposed to low concentrat in benzene.
ABSTRACT
The paper presented the implementation of the healthcare reform policy and initial success of Xinyu TCM Hospital in its reform pilot work of public hospital reform in Xinyu city ,Jiangxi province. The authors also analyzed problems and causes of the hospital in business development and cost control during the reform ,proposing to carry out TCM development policy ,enhance government investment ,streamline TCM service pricing ,and innovate TCM supporting model. In addition ,they also proposed TCM hospitals to enhance management ,and reform their mechanism to resolve such problems as high operating costs ,and poor talent development and lack of feature disciplines .
ABSTRACT
In this paper,the educational mode of master of public health (MPH) in America and China were reviewed through literatures searching and internet searching and the difference between America and China were compared from the sources of students,students' characters,educational objective,specialties and curricula,methods of teaching and management.There is still a certain gap in education of MPH in China.The educational mode needs optimizing with changing enrollment methods,definitude training objectives,perfect curriculum setting,increased opportunities for practice and strict quality control,so that the educational mode of MPH will be perfected in China.
ABSTRACT
<p><b>OBJECTIVE</b>Cytochrome P450 2E1 (CYP2E1) is an important metabolizing enzyme involved in oxidative stress responses to benzene, a chemical associated with bone marrow toxicity and leukemia. We aimed to identify the CYP2E1 genetic biomarkers of susceptibility to benzene toxicity in support of environmental and occupational exposure prevention, and to test whether a model using immortal human lymphocytes might be an efficient tool for detecting genetic biomarkers.</p><p><b>METHODS</b>Immortalized human lymphocyte cell lines with independent genotypes on four CYP2E1 SNP sites were induced with 0.01% phenol, a metabolite of benzene. CYP2E1 gene function was evaluated by mRNA expression and enzyme activity. DNA damage was measured by Single-Cell Gel Electrophoresis (SCGE).</p><p><b>RESULTS</b>Among the four SNPs, cells with rs2070673TT and rs2030920CC showed higher levels of CYP2E1 transcription and enzymatic activity than the other genotypes in the same SNP site. Cells with higher gene expression genotypes also showed higher comet rates compared with lower gene expression genotypes.</p><p><b>CONCLUSION</b>These results suggest that CYP2E1 rs2070673 and rs2030920 might be the genetic biomarkers of susceptibility to benzene toxicity and that the immortalized human lymphocytes model might be an efficient tool for the detection of genetic biomarkers of susceptibility to chemicals.</p>
Subject(s)
Adolescent , Adult , Humans , Middle Aged , Young Adult , Asian People , Benzene , Metabolism , Pharmacology , Cell Line , Cell Proliferation , Cytochrome P-450 CYP2E1 , Genetics , Lymphocytes , Metabolism , Phenol , Metabolism , PharmacologyABSTRACT
Objective To explore the mechanism of the skin lesion induced by oxidation hair dyes Methods The effects of subjects,such as oxidation hair dyes,hydrogen peroxide (H 2O 2) and p phenylenediamine (PPD) and their mixture which were main components of oxidation hair dyes,on the proliferation of rat's keratinocytes were detected by primary culture technique of rat's keratinocytes and MTT colorimetric assay Results All of the observed groups presented a certain inhibition on proliferation of the rat's keratinocytes,except the group exposed to PPD at the lowest dose for the shorter period The OD values decreased with the increase of exposure levels and periods Dose response relationship was observed between the exposure levels and inhibition rates of cell survival(the r values after 24 h exposue: r H 2O 2 =0 981, r PPD =0 949, r PPD-H 2O 2 =0 963, r hair dyes =0 887) Conclusion The skin lesion induced by oxidation hair dyes might associated with its cytotoxicity
ABSTRACT
Objective To study possible mechanisms of oxidative damages in rat lung type Ⅱ cells induced by cooking oil fume (COF). Methods The rat type Ⅱ lung cells were pretreated with anti_oxidant N_acetylcysteine (NAC) for 30 miuntes and were exposed to COF for 12 hours. The contents of MDA and GSH were detected with thiobarbituric acid colorimetric assay and 5,5_dithiobis 2_nitrobenzoic acid colorimetric assay. Results The significant increase of the contents of MDA and significant decrease of the contents of GSH were observed in the rat lung type Ⅱ cells with the increase of exposure doses of COF and the prolongation of exposure time of COF. The pretratment of NAC could reduce the production of MDA and increase the contents of GSH of the cells. Conclusion The possible mechanisms of oxidative damages in rat lung type Ⅱ cells induced by cooking oil rume might be formation of lipid peroxidation and interference of GSH anti_oxidative systems of the cells.