Regulated Gene Expression with Promoters Responding to Inducers

Genetically engineered transgenic animals and plants have proven to be extremely useful for analyzing biochemical and developmental processes.Promoters responding to chemical inducers will be powerful tools for basic research in molecular biology and biotechnological applications.Various chemical inducible systems based on activation and inactivation of the target gene had been described.The transfer of regulatory elements from prokaryotes,insects,and mammals has opened new avenues to construct chemically inducible promoters that differ in their ability to regulate the temporal and spatial expression patterns,and this will dramatically increase the application of transgenic technology.This review provides an overview on regulation of gene expression,promoter activating systems,promoter inactivation systems,inducible gene over expression,and inducible anti suppression.

Posttraumatic stress symptom trajectories of Chinese university students during the first eight months of the COVID-19 pandemic and their association with cognitive reappraisal,expressive suppression,and posttraumatic growth

Objective: To identify the moderating effects of cognitive reappraisal(CR) and expressive suppression(ES) on the relationship between posttraumatic stress(PTS) symptoms and posttraumatic growth(PTG) in university students. Methods: The survey included 1 987 Chinese university students who completed questionnaires on PTS symptoms in February 2020, with three follow-up surveys at two-month intervals until August 2020. We assessed CR and ES at February 2020 and PTG at August 2020. Growth mixture modeling was used to classify the PTS symptom trajectories. Multinomial logistic regression was used to recognize the predictors of class membership. The relationships among PTS symptoms, CR, ES, and PTG were examined using multi-group path analysis.Results: Sex, SARS-Co V-2 infection of a family member or friend, number of siblings, CR, and ES were significantly associated with PTS symptoms. Three latent classes were identified: ‘Increasing PTS’(n=205, 10.0%) who had rapid deterioration of PTS symptoms, ‘Moderate PTS’(n=149, 8.0%) who had a high level of PTS symptoms at the beginning and slightly increasing, and ‘Persistent Minimal PTS’(n=1 633, 82.0%), who had slow resolution of PTS symptoms over time. Male, SARS-Co V-2 infection of a family member or friend, and having a lower CR and a higher ES, were more likely to have ‘Increasing PTS’. PTS at February 2020 predicted PTG only in ‘Increasing PTS’ class, and both CR and ES had moderating effects on the conversion between them.Conclusions: Most students recovered from posttraumatic stress of COVID-19 pandemic, but a small proportion expeienced increasing PTS symptoms, and those with this condition may benefit from emotional regulation intervention.

Suppressive effect of dexamethasone on the neutrophil expression of CD18 in rats with radiation induced brain edema

BACKGROUND： Stereo-tactic radiation therapy （SRT） is widely used to treat intracranial diseases, but some patients suffered from radiation induced brain edema after SRT. Once radiation induced brain edema occurs, the treatment is quite difficult, and it always leads to a poor outcome. Dexamethasone has certain therapeutic effect on traumatic brain edema, but the biological mechanism is still unclear. OBJECTIVE ： To observe the effect of dexamethasone on the neutrophil expression of CD18.DESIGN ： A randomized control observation.SETTING： Changhai Hospital of the Second Military Medical University of Chinese PLA. MATERIALS ： The experiment was carried out in Changhai Hospital of the Second Military Medical University of Chinese PLA from January 1999 to December 1999. Twenty SD rats （male and female each in half） weighing （250±50） g were used. METHODS： Twenty SD rats were divided into four groups at random. ① Blank control group （n=5）： The rats were not treated without dexamethasone or irradiation;② Irradiation group （n=5）： The rats were given irradiation but no dexamethasone treatment; ③ Irradiation＋1 mg/kg dexamethasone group （n=5）; The rats were treated with irradiation and dexamethasone of 1 mg/kg; ④Irradiation＋5 mg/kg dexamethasone group （n=5）： The rats were treated with irradiation and dexamethasone of 5 mg/kg. The heads of the rats were irradiated with 10 MeV X-ray （30 Gy）, and brain tissue was removed after 2 weeks to observe the pathological changes. Blood samples were taken from the carotid artery, gradient centrifugation was used, and neutrophile layer was obtained, the level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were detected with Northern blot and flow cytometry respectively. MAIN OUTCOME MEASURES： ① Blood cell count; ② Pathological results; ③ level of neutrophile expression of CD18 mRNA and quantity of membrane proteins. RESULTS ： All the 20 SD rats were involved in the analysis of results without deletion. At 2 weeks after irradiation, obvious cell injury could be observed under light microscope. The level of neutrophile expression of CD18 mRNA and quantity of membrane proteins in blood were obviously increased, but the severity of cell injury was relieved in the irradiation＋1 and 5 mg/kg dexamethasone groups, and the CD18 expression was markedly suppressed （P 〈 0.05）, and the suppression was more obvious in the irradiation＋5 mg/kg dexamethasone group than in the irradiation＋1 mg/kg dexamethasone group （P 〈 0.01 ）. CONCLUSION： Dexamethasone can reduce the radiation induced brain edema by inhibiting the expression of CD18.

Psychological impacts of the COVID-19 epidemic on Chinese people: Exposure, post-traumatic stress symptom, and emotion regulation

Objective:To examine the effects of coronavirus disease-2019(COVID-19)exposure,expressive suppression/cognitive reappraisal,and demographic variables on post-traumatic stress symptoms(PTS)among Chinese.Methods:Participants were recruited by social media through We Chat and 6049 Chinese(aged from 17 to 63 years;median=24)from 31 provinces were included in the study.PTS symptoms,expressive suppression,and cognitive reappraisal were assessed after the outbreak of COVID-19.A regression mixture analysis was conducted in Mplus 7.Results:A regression mixture model identified three latent classes that were primarily distinguished by differential effects of COVID-19 exposures on PTS symptoms:(1)Class 1(mildly PTS symptoms,80.9%),(2)Class 2(moderate PTS symptoms,13.0%),and(3)Class 3(high PTS symptoms,6.1%).The results demonstrated that the young,women and people with responsibilities and concerns for others were more vulnerable to PTS symptoms;and they had more expression inhibition and less cognitive reappraisal in three latent classes.Conclusions:The findings suggest that more attention needs to be paid to vulnerable groups such as the young,women and people with responsibilities and concerns for others.Therapies to encourage emotional expression and increase cognitive reappraisal may also be helpful for trauma survivors.

Experimental study on siRNA expressing vector-based RNA interference targeting c-Myc in human hepatocellular carcinoma cell line BEL-7402

Objective: To explore the inhibition of the expression of c-Myc in human hepatocellular carcinoma via vector-based RNA interference (RNAi). Methods: Two RNA interference DNA templates targeting c-Myc oncogene were designed via online software and synthesized. By ligation, the fragments were inserted into pSilencer 1.0-U6 to construct the recombinant siRNA expressing plasmids. The identified recombinants were introduced into BEL-7402 cells with Lipofactamine. The inhibition of c-Myc expression, together with the expression of CDK4, hTERT and Gadd45β in c-Myc down-regulated BEL-7402 cells, were analyzed by semi-quantitative RT-PCR. Results: Two recombinant plasmids pSic-myc-1 and pSic-myc-2, which direct the yields of siRNAs targeting c-Myc in cells, were constructed. Among which, pSic-myc-2 was shown to trigger a RNAi-mediated inhibition of expression of c-Myc in BEL-7402 by up to 90%. In c-Myc knockdown BEL-7402 cells, the expression of CDK4 and hTERT were down-regulated with a ratio of 85% and 57%, respectively, while the expression of Gadd45β was up-regulated by up to 110%. Conclusion: The expression of c-Myc in BEL-7402 could be suppressed by vector-based RNA interference successfully. The knockdown of c-Myc in turn resulted in the changes of expression of genes related to cell proliferation and apoptosis. Thus, our study provided a preliminary data in searching of a c-Myc-targeted RNAi therapy of human hepatocellular carcinoma.

Suppression dampens unpleasant emotion faster than reappraisal:Neural dynamics in a Chinese sample

The timing dynamics of regulating negative emotion with expressive suppression and cognitive reappraisal were investigated in a Chinese sample. Event-Related Potentials were recorded while subjects were required to view, suppress emotion expression to, or reappraise emotional pictures. The results showed a similar reduction in self-reported negative emotion during both strategies. Additionally, expressive suppression elicited larger amplitudes than reappraisal in central-frontal P3 component(340–480 ms). More importantly, the Late Positive Potential(LPP) amplitudes were decreased in each 200 ms of the 800–1600 ms time intervals during suppression vs. viewing conditions. In contrast, LPP amplitudes were similar for reappraisal and viewing conditions in all the time windows, except for the decreased amplitudes during reappraisal in the 1400–1600 ms. The LPP(but not P3) amplitudes were positively related to negative mood ratings, whereas the amplitudes of P3, rather than LPP, predict self-reported expressive suppression. These results suggest that expressive suppression decreases emotion responding more rapidly than reappraisal, at the cost of greater cognitive resource involvements in Chinese individuals.

JNK1 negatively controls antifungal innate immunity by suppressing CD23 expression

Subject Code:H10 With the support by the National Natural Science Foundation of China,a study by Dr.Lin Xin(林欣)’s groups from the Institute for Immunology,School of Medicine,Tsinghua University demonstrates that JNK1negatively regulates CD23,a novel C-type lectin receptor(CLR)with antifungal properties。