Integrated microRNA-mRNA analysis reveals the roles of microRNAs in the muscle fat metabolism of Yanbian cattle.

Fat deposition is an important economic trait in farm animals. However, it is difficult to genetically improve intramuscular fat deposition via trait-based cattle breeding. The main objectives of this study were to analyze the factors about beef flavor, and to detect functional microRNA (miRNA, miR) associated with intramuscular fat deposition in Yanbian cattle. Longissimus dorsi samples from six steers were separated into high- and low-fat groups (n = 3 each) based on the marbling score, and transcriptomic analysis was performed using miRNA sequencing. A total of 33 miRNAs and 38 genes were found to be differentially expressed in the high- and low-fat groups. Quantitative real-time polymerase chain reaction was performed to validate the sequencing results. Integrated miRNA-mRNA analysis revealed that miRNA-associated target genes were primarily associated with skeletal muscle development. However, some of the miRNAs (miR-424 etc.) and genes (ATF3 etc.) were also associated with fat metabolism. A targeted relationship between miR-22-3p and the WFIKKN2 gene and its involvement in adipocyte differentiation were confirmed experimentally. The study findings may provide potential candidate molecular targets for the selection of cattle with improved meat quality.

[Analysis of chronic obstructive pulmonary disease screening questionnaire and pulmonary function test among migrant workers exposed to dust].

Objective: To analyze the application of Chronic Obstructive Pulmonary Disease (COPD) Screening Questionnaire and pulmonary function test in dust-exposed migrant workers. Methods: In May 2019, 149 cases of dust exposed migrant workers were selected as the research subjects through the free clinic in the countryside. COPD Screening Questionnaire and lung function test were carried out to analyze the high-risk groups and the influencing factors of positive pulmonary function test results. Results: Among 149 cases of dust-exposed migrant workers, 107 (71.8%) were positive for questionnaire screening, 73 (49.0%) were positive for pulmonary function test, 75 (50.3%) were diagnosed with coal worker's pneumoconiosis, and 101 (67.8%) were diagnosed with lung function injury. The positive rate of pulmonary function of migrant workers with positive questionnaire screening results was significantly higher than that of those with negative results (P<0.05) . The results of multivariate analysis showed that compared with non-pneumoconiosis, the risk of positive pulmonary function test results was higher in dust-exposed migrant workers with stage Ⅲ pneumoconiosis (OR=16.462, 95%CI: 3.390-79.946; P<0.01) . Compared with non-smoking, the risks of positive pulmonary function test results of dust-exposed migrant workers with smoking index of 11-20 package years and >20 package years were higher (OR=19.814, 95%CI: 3.854-101.883; OR=9.733, 95%CI: 2.310-41.008; P<0.01) . Conclusion: The risk of COPD in dust-exposed migrant workers is high, so we should strengthen the early examination of the high pneumoconiosis stage and smoking population. The screening questionnaire can better screen out the high-risk groups of COPD, and it can be used as a basic screening tool.

Bovine bta-microRNA-1271 Promotes Preadipocyte Differentiation by Targeting Activation Transcription Factor 3.

Yanbian yellow cattle are one of the top five largest breeds of cattle in China. We had previously found that bta-miR-1271 is differentially expressed in the longissimus dorsi muscles of Yanbian yellow bulls and steers. However, whether bta-miR-1271 affects bovine fat formation is unclear. In this study, we used target gene prediction, dual-luciferase reporter assay, and transfection-mediated overexpression and inhibition of bta-miR-1271 in a culture of Yanbian yellow cattle preadipocytes to investigate the role of bta-miR-1271 in adipogenesis. We showed that bta-miR-1271 directly targets the 3'-untranslated region (3'-UTR) of the activating transcription factor 3 (ATF3) mRNA and downregulates its expression. Overexpression of bta-miR-1271 enforced by the miRNA mimics promoted triglyceride accumulation and significantly upregulated expression of the adipogenic peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer-binding protein α (C/EBPα) genes at both the protein and mRNA levels, as demonstrated by RT-qPCR and Western blot analyses. Conversely, inhibition of bta-miR-1271 expression produced the opposite effect. Our results show that bta-miR-1271 regulates differentiation of Yanbian yellow cattle preadipocytes by inhibiting ATF3 expression, which highlights the importance of microRNA-mediated regulation of adipogenesis. miR-1271 and its target gene(s) may provide a new research direction for investigating biological agents affecting intramuscular fat deposition in cattle.