1.Determination of 2, 4-dichlorophenoxyacetic acid in air of workplace by high-performance liquid chromatography.
Yanan WEN ; Zhaohui FU ; Jianning XU ; Shichuan TANG ; Quankai WANG ; Huanhuan LI ; Guangyun XIE ; Yuling ZHU ; Yiting GU ; Feng TAN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2014;32(6):458-459
OBJECTIVETo develop a method for determination of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the air of workplace by high-performance liquid chromatography.
METHODS2, 4-D was collected by ultrafine glass filters, desorbed by methanol, separated by a C18 column, and detected by a UV detector. Identification and quantification of 2, 4-D were performed by retention time and peak areas, respectively.
RESULTSThe linear range of the test was 2∼200 µg/ml; the elution efficiency was 94.6%- 95.9%; the limit of detection (S/N = 3) was 0.034 µg/ml (injection volume of 20 µl eluant); the lower limit of quantification (S/N = 10) was 0.11 µg/ml; the minimum detectable concentration was 0.011 mg/m(3); the minimum quantifiable concentration was 0.037 mg/m(3) (with sampled air volume of 45 L).
CONCLUSIONThis method is convenient and simple in sample collection and preparation, and satisfies all methodological requirements. Therefore, this method is useful for the determination of 2, 4-D in the air of workplace.
2,4-Dichlorophenoxyacetic Acid ; analysis ; Air ; analysis ; Air Pollutants, Occupational ; analysis ; Chromatography, High Pressure Liquid ; methods ; Workplace
2.TRIM25 inhibits HBV replication by promoting HBx degradation and the RIG-I-mediated pgRNA recognition.
Hongxiao SONG ; Qingfei XIAO ; Fengchao XU ; Qi WEI ; Fei WANG ; Guangyun TAN
Chinese Medical Journal 2023;136(7):799-806
BACKGROUND:
The hepatitis B virus (HBV) vaccine has been efficiently used for decades. However, hepatocellular carcinoma caused by HBV is still prevalent globally. We previously reported that interferon (IFN)-induced tripartite motif-containing 25 (TRIM25) inhibited HBV replication by increasing the IFN expression, and this study aimed to further clarify the anti-HBV mechanism of TRIM25.
METHODS:
The TRIM25-mediated degradation of hepatitis B virus X (HBx) protein was determined by detecting the expression of HBx in TRIM25-overexpressed or knocked-out HepG2 or HepG2-NTCP cells via Western blotting. Co-immunoprecipitation was performed to confirm the interaction between TRIM25 and HBx, and colocalization of TRIM25 and HBx was identified via immunofluorescence; HBV e-antigen and HBV surface antigen were qualified by using an enzyme-linked immunosorbent assay (ELISA) kit from Kehua Biotech. TRIM25 mRNA, pregenomic RNA (pgRNA), and HBV DNA were detected by quantitative real-time polymerase chain reaction. The retinoic acid-inducible gene I (RIG-I) and pgRNA interaction was verified by RNA-binding protein immunoprecipitation assay.
RESULTS:
We found that TRIM25 promoted HBx degradation, and confirmed that TRIM25 could enhance the K90-site ubiquitination of HBx as well as promote HBx degradation by the proteasome pathway. Interestingly, apart from the Really Interesting New Gene (RING) domain, the SPRY domain of TRIM25 was also indispensable for HBx degradation. In addition, we found that the expression of TRIM25 increased the recognition of HBV pgRNA by interacting with RIG-I, which further increased the IFN production, and SPRY, but not the RING domain is critical in this process.
CONCLUSIONS
The study found that TRIM25 interacted with HBx and promoted HBx-K90-site ubiquitination, which led to HBx degradation. On the other hand, TRIM25 may function as an adaptor, which enhanced the recognition of pgRNA by RIG-I, thereby further promoting IFN production. Our study can contribute to a better understanding of host-virus interaction.
Humans
;
Hepatitis B virus
;
DEAD Box Protein 58/metabolism*
;
RNA
;
Liver Neoplasms
;
Virus Replication
;
Tripartite Motif Proteins/genetics*
;
Transcription Factors
;
Ubiquitin-Protein Ligases/genetics*