Advances on nervous system impairment induced by hand-transmitted vibration / 环境与职业医学

Hand-transmitted vibration is one of the most common physical harmful factors in the workplace，and the hand-arm vibration syndrome caused by it lacks effective treatment, and seriously affects the physical and mental health of the involved workers. As an important target for hand-transmitted vibration, the nervous system has attracted increasing attention from scholars, and much progress has been made in recent years in studying the effects of hand-transmitted vibration on nervous system function. Based on related literature at home and abroad, this paper introduced the hand-transmitted vibration-associated damage in peripheral, autonomic, and central nervous systems, and then explored the associated influence factors, like vibration frequency, environment temperature, and individual factors. The potential directions for further research were also proposed.

Effects of hand-transmitted vibration on fingertip terminal nerve: A meta-analysis / 环境与职业医学

Background Hand-transmitted vibration is one of the most common occupational hazards and is closely related to symptoms of fingertip terminal nerve damage. Objective To analyze the effects of hand-transmitted vibration on the terminal nerve of fingertips. Methods We systematically searched literature about the effects of hand-transmitted vibration on fingertip terminal nerve at home and abroad. The outcome index was the number (rate) of fingertip terminal nerve symptoms reported by the vibration group and the control group, such as finger numbness and finger tingling, and the search period was from database inception to December 2021. The quality of cross-sectional studies was assessed using the criteria recommended by the Agency for Healthcare Research and Quality (AHRQ), and the quality of cohort studies was assessed by the Newcastle-Ottawa Scale (NOS). NoteExpress 3.2 was used for literature management, and Excel 2003 was used for data collection and extraction. RevMan 5.4.1 software was used for statistical analysis, and random effect model was used to calculate the OR value of pooled effects and to draw forest plots. Subgroup analysis was carried out according to the working years with vibration exposure. At the same time, sensitivity analysis was performed after excluding studies with the largest weight and funnel plots were generated to evaluate publication bias. Results A total of 3619 articles were retrieved, and 39 articles were finally included, including 29 Chinese articles and 10 English articles; 36 cross-sectional studies and 3 cohort studies. In total, 8399 subjects were studied, including 5673 cases in the vibration exposure group and 2726 cases in the control group. Random effect model was used to merge the included literature. The results of meta-analysis showed that compared with the control group, hand-transmitted vibration was significantly associated with the self-reported occurrence of finger numbness (OR=8.29, 95%CI: 5.43-12.66), finger tingling (OR=7.50, 95%CI: 4.78-11.77), finger swelling (OR=8.25, 95%CI: 4.06-16.76), finger stiffness (OR=10.71, 95%CI: 3.60-31.87), finger trembling (OR=5.11, 95%CI: 2.60-10.04), hand weakness (OR=11.05, 95%CI: 3.98-30.68), hand sweating (OR=2.70, 95%CI: 1.64-4.43), hand coldness (OR=3.54, 95%CI: 2.42-5.18) (P<0.01). The subgroup analysis showed that the odds ratios of both finger numbness and finger tingling increased in the early and middle stages of vibration exposure (<5 years and 5-10 years of exposure duration）(finger numbness: OR=11.11, 19.07; finger tingling: OR=4.70, 16.55, respectively)(P<0.01), and decreased in the late stage of vibration exposure (10-15 years and ≥15 years of exposure duration) (finger numbness: OR=9.57, 2.30; finger tingling: OR=5.71, 6.00, respectively) (P<0.01). The results of sensitivity analysis showed a stable pooled effect (OR=13.96, 95%CI: 4.85-40.13, Z=4.89, P<0.01). The funnel plot results showed positive publication bias. Conclusion Occupational exposure to hand-transmitted vibration can cause finger numbness, finger tingling, finger swelling, finger stiffness, finger trembling, hand weakness, hand sweating, and hand coldness.

The effect of PM2.5 on oncogene expression in HBE cells / 中华劳动卫生职业病杂志

Objective@#To study the effect of particulate matter 2.5 (PM2.5) on oncogene expression in human bronchial epithelial (HBE) cells.@*Methods@#HBE cells were selected as the study subjects, and PM2.5 treatment group (10 μg/ml and 50 μg/ml) , negative control group and positive control group (10 μmol/L Cr6+) were set. CCK8 assay was used to test the IC50 value of PM2.5. HBE cells were treated with PM2.5 for 24 h at 10 μg/ml and 50 μg/ml, additionally, cells were treated with blank as negative control, 10 μmol/L Cr6+ as a positive control for 24 h. After the treatment, mRNA expression of oncogenes including c-myc, c-fos, k-ras and p53 were detected by fluorescent quantitative RT-PCR, the protein expression of oncogenes were detected with western blot.@*Results@#The IC50 value of PM2.5 in HBE cells is 70.12 μg/ml. The qRT-PCR data showed that compared with the control group, the expression level of c-myc gene increased by respectively 500.1%、780.7%、305.3% after exposure to 10、50 μg/ml PM2.5 and positive control group; c-fos gene increased respectively 34.0%、76.7%、131.3% after exposure to 10、50 μg/ml PM2.5 and positive control group; k-ras gene increased respectively 50.3%、107.0%、49.7% after exposure to 10、50 μg/ml PM2.5 and positive control group; p53 gene decreased by 28.3%、28.7%、59.7% after exposure to 10、50 μg/ml PM2.5 and positive control group. The western blot results showed that compared with the control group, c-myc protein increased respectively 29.7%、77.3% after exposure to 50 μg/ml PM2.5 and positive control group; c-fos protein increased respectively 200.3%、137.0% after exposure to 50 μg/ml PM2.5 and positive control group; k-ras protein increased respectively 106.3%、130.3%、116.7% after exposure to 10、50 μg/ml PM2.5 and positive control group; p53 protein decreased by 43.7%、53.3%、52.1% after exposure to 10、50 μg/ml PM2.5 and positive control group.@*Conclusion@#PM2.5 could promote the expression of oncogenes in HBE cells, the carcinogenicity of haze might be related to promotion of oncogenes expression induced by PM2.5.

Construction of 3β-HSD gene silencing cell line and its effects on apoptosis induced by DEHP / 中华劳动卫生职业病杂志

Objective@#To construct 3β-HSD gene shRNA lentivirus interference vecto, then transfect into human MCF-7 cells, and construct cell line with 3β-HSD gene silencing, finally to study the effects of 3β-HSD on apoptosis induced by di- (2-ethylhexyl) phthalate (DEHP) .@*Methods@#According to the mRNA sequence of 3β-HSD gene provided by GenBank, three interference sequences were designed and connected to PLVX-shRNA2-puro after annealing. The recombinant lentivirus vector was transfected into 293FT cells, the virus supernatants were collected and infected with MCF-7 cells. After puromycin screening, MCF-7 cells with 3β-HSD gene silencing were constructed. The cells with 3β-HSD gene silencing were identified by real-time quantitative PCR and western blot. Then the 3β-HSD gene silencing cells and MCF-7 cells were treated at various doses of DEHP for 24 hours to detect the gene expression and protein expression of apoptosis genes including Bax, Caspase-3 and Caspase-8.@*Results@#The interference sequence of 3β-HSD gene inserted into lentivirus vector PLVX-shRNA2-puro is consistent with the designed sequence. 3β-HSD gene expression level in MCF-7 cells with 3β-HSD gene silencing was 77% lower than than that of control MCF-7 cells. 3β-HSD protein level in MCF-7 cells with 3β-HSD gene silencing was 74% lower than that of control MCF-7 cells. After DEHP treatment in MCF-7 cells with 3β-HSD gene silencing and control MCF-7 cells, qRT-PCR results showed that Bax gene expression levels increased by 28%-54%, Caspase-3 gene increased by 13%-49%, Caspase-8 gene increased by 21%-70% in MCF-7 cells when compared with the control group. Additionally, in the 3β-HSD gene silencing cells, Bax gene expression level decreased by 11%-28%, Caspase-3 gene expression decreased by 12%-23%, Caspase-8 gene expression decreased by 11%-34%, compared with the same treatment group of MCF-7 cells. Western blot results showed that Bax protein expression level increased by 28%-61%, Caspase-3 protein expression level increased by 40%-48%, Caspase-8 protein increased by 31%-84% in MCF-7 cells when compared with the control group. In 3β-HSD gene silencing cells, Bax protein expression level increased by 11%-27%, Caspase-3 protein increased by 21%-40%, Caspase-8 protein increased by 12%-25%, compared with the same treatment group of MCF-7 cells.@*Conclusion@#The stable 3β-HSD gene silencing cell line are successfully constructed in this study. DEHP can induce increased expression of apoptotic gene and protein. Silencing of 3β-HSD gene can inhibit the activation of apoptotic gene by DEHP in a certain degree.

Effects of 3β-HSD gene silence or overexpression on DEHP induced oxidative damage in MCF-7 cells / 中华劳动卫生职业病杂志

Objective@#To study the oxidative damage of di- (2-ethylhexyl) phthalate (DEHP) on MCF-7 cells, and to investigate the effects of 3β-hydroxysteroid dehydrogenase (3β-HSD) gene silence or overexpression on DEHP-induced oxidative damage.@*Methods@#MCF-7 cells, 3β-HSD gene silencing cells and 3β-HSD gene overexpression cells were treated with different doses of DEHP (0,0.05,0.1,0.2,0.4,0.8 mmol/L) for 24h, then intracellular oxidative damage index such as MDA, SOD, GSH, GSH-PX were detected, DNA repair gene hOGG1, hMTH1 mRNA expression were tested by Q-PCR, hOGG1, hMTH1 protein expression were detected by western blot.@*Results@#After MCF-7 cells were treated by DEHP, MDA levels increased; SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the differences were statistically significant when compared with control (P<0.05 or P<0.01) . In 3β-HSD gene silencing cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content increased, SOD activity, GSH content, GSH-PX activity decreased, hOGG1 and hMTH1 mRNA expression levels decreased, hOGG1 and hMTH1 protein expression levels decreased, the difference were statistically significant (P<0.05 or P<0.01) . In 3β-HSD gene overexpression cells which were treated by DEHP, when compared with the same dose group of MCF-7 cells, MDA content decreased; SOD activity, GSH content, GSH-PX activity increased, of hOGG1 and hMTH1 mRNA expression levels increased, hOGG1 and hMTH1 protein expression levels increased, the difference were statistically significant (P<0.05 or P<0.01) .@*Conclusion@#DEHP could cause oxidative damage in MCF-7 cells, induce the changes of related genes and proteins, 3β-HSD plays an antioxidant role in the process of DEHP ox-idative damage.

Establishment of human neuroblastoma SH-SY5Y cell line stably silencing beclin1 / 生物医学工程学杂志

The pGenesil-1-Beclin1 eukaryotic expression vectors were constructed to establish an SH-SY5Y cell line stably expressing shRNA-Beclin1. The shRNA was connected to pGenesil-1 to construct the recombinant plasmid pGenesil-1-Beclin1, which was transformed into JM109 E. coli. Positive clones were identified by digestion with restriction endonuclease and DNA sequencing. SH-SY5Y cells were cultured by the conventional method. The pGenesil-1-Beclin1 and pGenesil-1 plasmids were transfected into SH-SY5Ycells, and the cells were screened by G418 until the stable G418-resistant monoclonal cells were acquired. Beclin1 mRNA and Beclin1 protein were detected by RT-PCR and Western blot analysis respectively. The results of restriction endonuclease analysis and DNA sequencing confirmed the correct construction of the eukaryotic expression vector pGenesil-1-Beclin1. Two SH-SY5Y transfected cell lines were successfully selected. Compared with the control group, RT-PCR and Western blot showed that the expression of Beclin1 mRNA and protein were down regulated 71.28% ± 1.45% (P < 0.05)and 75.50% ± 2.63% (P < 0.05), respectively. The results indicated that the eukaryotic expression vector pGenesil-1-Beclin1 was successfully constructed and the SH-SYSY cell lines with inhibited Beclin1 expression were established. It provides a useful cell model for studying the biological function of Beclin1.