ABSTRACT
Objective::To observe the effect of icariin on damaged neurons from the perspective of endoplasmic reticulum stress, in order to explore some mechanisms for repairing damaged neurons. Method::PC12 cells were induced by nerve growth factor (NGF) to differentiate into neurons, and the positive rate of microtubule associated protein-2 (MAP2) and neuron-specific enolase (NSE) expressions was determined by flow cytometry. The experiment was divided into 4 groups, blank control group: PC12 induced differentiation into neuronal cells, solvent control group: PC12 induced differentiation into neurons+ 0.1% dimethyl sulfoxide (DMSO), thapsigargin group: PC12 induced differentiation into nerves Yuan+ 2 μmol·L-1 thapsigargin, and icariin group: PC12 induced differentiation into neurons+ 2 μmol·L-1 thapsigargin+ 0.1 μmol·L-1 icariin. The proliferation of the cells was detected by using cell counting kit-8(CCK-8) method, the apoptosis of the cells was detected by flow cytometry, the protein expressions of CCAAT/enhace-binding protein homologous protein(CHOP) and glucoseregulated protein 78(Grp78) were detected by Western blot, and the mRNA expressions of CHOP and Grp78 were detected by real-time quantitative PCR (Real-time PCR). Result::Compared with the solvent control group, the thapsigargin group inhibited the proliferation of neuron-like PC12 cells induced by NGF, promoted apoptosis, and up-regulated the expressions of CHOP and Grp78 (P<0.05, P<0.01). Compared with the thapsigargin group, the icariin group can alleviate the inhibition of neurotrophic activity by thapsigargin, reduce neuronal apoptosis, and down-regulate the expressions of CHOP and Grp78 (P<0.05, P<0.01). Conclusion::Icariin can inhibit endoplasmic reticulum stress by down-regulating the expressions of CHOP and Grp78 and promote the repair of damaged neurons.
ABSTRACT
Objective@#To explore the related influencing factors of high frequency hearing loss (HFHL) in workers exposed to noise and establish a prediction nomogram for HFHL.@*Methods@#A total of 822 workers exposed to noise from 46 enterprises were included. A questionnaire survey and a pure-tone hearing test were conducted for the workers. The data of noise level of the workers exposed was also collected. After single factor analysis of related influencing factors, the multivariate Logistic regression analysis was performed to identify the final independent influencing factors of HFHL. Finally, a nomogram model was established by R software to achieve individual prediction of HFHL.@*Results@#Among the 822 workers exposed to noise, 166 (20.2%) workers had HFHL. In multivariate Logistic regression analysis, increasing age, men, increasing wearing earphone time, less wearing earplugs, and high noise level were the independent risk factors for HFHL. The C-index of the nomogram model for predicting HFHL was 0.834 (95%CI: 0.748~0.903) . The area under the predictive power curve of nomogram model was 0.834 (95%CI: 0.799~0.869, P<0.001) .@*Conclusion@#Age, sex, wearing earphone time, wearing earplugs, and noise level are independent influence factors for HFHL. The nomogram model is successfully established as a accurate and visible tool for individually predicting the HFHL risk in workers exposed to noise.
ABSTRACT
Objective To develop a nylon membrane chip for rapid and systematic detection of the diabetes-associated 45 mutant loci in mitochondrial DNA(mtDNA).Methods The mutant-and wild-type probes were designed for detection of 45 mutant loci in mtDNA with Primer Premier 5.0 and NCBI BLAST softwares and the 90 probes with 8 poly T were immobilized on the Hybond N~+ nylon membranes which were treated with 5?SSC Buffer by UV-crosslinking;Then asymmetric PCR was employed to obtain the target single strand DNA(ssDNA).The PCR products were labeled with biotin after purification.NBT/BCIP was used as substrate that yields a very intense purple signal followed by AP-avidin,and the signals were observed in 24 samples with known sequences to evaluate the chips,each sample was repeatedly measured three times.Results The specific target fragments of 45 loci can be amplified under the same condition with nine sets of primers.The annealing temperatures of the wild-type [(59.01?1.42)℃] and mutant-type [(59.34?1.29)℃ ] probes are so close(t=1.046,P =0.301)that hybridization can be performed at the same temperature.The spots on the membrane chip are distinct,regular and well-distributed.The results of positive-and negative-control are perfect.The signals of negative probes and the background are similar.The results of chip were nearly concordant with that of DNA sequences(?~2=113.132,Kappa value =0.888,P = 0.000)except for T16189C mutant.Conclusions We have successfully developed a nylon membrane chip for rapid and systematic detection of the diabetes-associated 44 mutant loci in mtDNA.It could be used for screening for diabetic patients and high-risk people.