A Novel Site-Specific Integration System for Genetic Modification of Aspergillus flavus

Aspergillus flavus is a fungus that produces aflatoxin B1, one of the most carcinogenic secondary metabolites. Understanding the regulation mechanism of aflatoxin biosynthesis in this fungus requires precise methods for genomic integration of mutant alleles. To avoid the disadvantage of DNA integration into the genome by non-homologous or ectopic recombination, we developed a novel strategy for site-specific integration of foreign DNA by using a carboxin-resistant sdh2R allele (His 249 Leu). Our results demonstrated that the transformants were generated with a high efficiency (>96%) of correct integration into the sdh2-lcus of the genome of A. flavus NRRL 3357. The advantage of this method is that introduction of the eGFP expression cassette into the sdh2-locus had little effect on fungal growth and virulence while also being rapid and efficient. This system will be a valuable tool for genetic manipulation in A. flavus. To the best of our knowledge, this is the first report on the efficient site-specific integration at the sdh2-locus in the genome of Aspergillus

Impact of Resource-Based Economic Transformation Policy on Sulfur Dioxide Emissions: A Case Study of Shanxi Province

Air pollution, particularly SO2 emission, has become a global problem, seriously threatening the sustainable development and health of mankind. Based on the panel data of 248 prefecture-level cities in China during 2003–2018, this study used the Propensity Score Matching-Difference in Difference (PSM-DID) method within the counterfactual framework to evaluate the treatment effect of the policy made by the National Resource-Based Economic Transformation Comprehensive Supporting Reform Pilot Zone (CRZ) on sulfur dioxide (SO2) emissions. The results show the following. (1) The benchmark regression results demonstrate that the CRZ policy has significantly decreased per capita SO2 emissions (PCSO2) and SO2 emissions per unit of GDP (PGSO2) in the pilot zone, and the placebo test indicates that the evaluation of the policy effect is robust. (2) The dynamic effect test indicates that there is a lag in the effect of the CRZ policy on reducing SO2 emissions. The policy effect of the CRZ policy on PCSO2 and PGSO2 was not obvious in the first stage (2011–2015), the CRZ policy significantly reduced the PCSO2 and PGSO2 in the second stage of policy implementation (2016 and beyond), and the reduction effect of CRZ policy on SO2 emissions is increasing over time. (3) The mechanism analysis shows that optimizing industrial structure, increasing human capital, strengthening technological innovation, and expanding opening to the outside world are the main ways for the CRZ policy to reduce SO2 emissions. The study will help promote SO2 emissions reduction in Shanxi Province, providing a reference for the transformation and development of other resource-based cities in China and the world and contributing to accelerating the achievement of regional emission reduction targets and sustainable development

Impact of Resource-Based Economic Transformation Policy on Sulfur Dioxide Emissions: A Case Study of Shanxi Province

Air pollution, particularly SO2 emission, has become a global problem, seriously threatening the sustainable development and health of mankind. Based on the panel data of 248 prefecture-level cities in China during 2003–2018, this study used the Propensity Score Matching-Difference in Difference (PSM-DID) method within the counterfactual framework to evaluate the treatment effect of the policy made by the National Resource-Based Economic Transformation Comprehensive Supporting Reform Pilot Zone (CRZ) on sulfur dioxide (SO2) emissions. The results show the following. (1) The benchmark regression results demonstrate that the CRZ policy has significantly decreased per capita SO2 emissions (PCSO2) and SO2 emissions per unit of GDP (PGSO2) in the pilot zone, and the placebo test indicates that the evaluation of the policy effect is robust. (2) The dynamic effect test indicates that there is a lag in the effect of the CRZ policy on reducing SO2 emissions. The policy effect of the CRZ policy on PCSO2 and PGSO2 was not obvious in the first stage (2011–2015), the CRZ policy significantly reduced the PCSO2 and PGSO2 in the second stage of policy implementation (2016 and beyond), and the reduction effect of CRZ policy on SO2 emissions is increasing over time. (3) The mechanism analysis shows that optimizing industrial structure, increasing human capital, strengthening technological innovation, and expanding opening to the outside world are the main ways for the CRZ policy to reduce SO2 emissions. The study will help promote SO2 emissions reduction in Shanxi Province, providing a reference for the transformation and development of other resource-based cities in China and the world and contributing to accelerating the achievement of regional emission reduction targets and sustainable development

Androgen receptor and heat shock protein 27 co-regulate the malignant potential of molecular apocrine breast cancer

Abstract Background The most striking feature of molecular apocrine breast cancer (MABC) is the expression of androgen receptor (AR). We report here the mechanism of the AR in regulating the behavior of MABC. Methods The MABC cell line, MDA-MB-453, and the nonMABC cell line, MCF7, were used in this study. The effect of dihydrotestosterone (DHT) and heat shock protein 27 (HSP27) on cell proliferation was quantified using the cell counter kit-8 (CCK8) and clonogenic assays in vitro and by a xenograft tumor model in vivo. The expression of the AR and HSP27 was analyzed using western blot, qPCR, and immunofluorescence assays. Complexes of the AR and HSP27 were detected by co-immunoprecipitation (Co-IP). Results In MDA-MB-453 cells, DHT promoted cell proliferation and stimulated AR and HSP27 translocation from the cytoplasm to the nucleus, whereas, it inhibited MCF7 cell growth, and only the AR translocated into the nucleus. HSP27 knock-down decreased the proliferative ability of MDA-MB-453 cells, which could be rescued by DHT, while HSP27 and DHT had synergistic effects on MCF7 cells. HSP27 phosphorylation was a prerequisite for AR translocation into the nucleus, especially phosphorylation on serine 82. In addition, DHT stimulated the tumorigenic and metastatic capacities of MDA-MB-453 cells, while HSP27 knock-down decreased the rate of tumor formation and induced apoptosis in cells. Conclusions The results suggest that HSP27 assists the AR in regulating the malignant behavior of MABC, and these findings might be helpful in the treatment of MABC

Additional file 2 of Host sex disparity and viral genotype dependence of the glycosylation level of small Hepatitis B surface protein in patients with HBeAg-positive chronic Hepatitis B

Supplementary Material

Additional file 1 of Host sex disparity and viral genotype dependence of the glycosylation level of small Hepatitis B surface protein in patients with HBeAg-positive chronic Hepatitis B

Supplementary Material

AR–PDEF pathway promotes tumour proliferation and upregulates MYC-mediated gene transcription by promoting MAD1 degradation in ER-negative breast cancer

Abstract Background Androgen receptor (AR) is expressed in 60%~ 70% oestrogen receptor (ER)-negative breast cancer (BC) cases and promotes the growth of this cancer subtype. Expression of prostate-derived Ets factor (PDEF), a transcription factor, is highly restricted to epithelial cells in hormone-regulated tissues. MYC and its negative regulator MAD1 play an important role in BC progression. Previously, we found that PDEF expression is strongly correlated with AR expression. However, the relationship between AR and PDEF and the function of PDEF in ER-negative BC proliferation are unclear. Methods AR and PDEF expression in ER-negative BC tissues and cell lines was determined by performing immunohistochemistry or western blotting. Protein expression levels and location were analysed by performing western blotting, RT-qPCR and immunofluorescence staining. Co-immunoprecipitation and chromatin immunoprecipitation assays were performed to validate the regulation of AR–PDEF–MAD1–MYC axis. Moreover, the effect of AR and PDEF on BC progression was investigated both in vitro and in vivo. Results We found that PDEF was overexpressed in ER-negative BC tissues and cell lines and appeared to function as an oncogene. PDEF expression levels were strongly correlated with AR expression in ER-negative BC, and PDEF transcription was positively regulated by AR. PDEF upregulated MYC-mediated gene transcription by promoting MAD1 degradation in ER-negative BC. Finally, we found that compared with the inhibition of AR expression alone, simultaneous inhibition of AR and PDEF expression further suppressed tumour proliferation both in vitro and in vivo. Conclusions Our data highlight the role of the AR–PDEF–MAD1–MYC axis in BC progression and suggest that PDEF can be used as a new clinical therapeutic target for treating ER-negative BC