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Abstract Background Benzo [a] pyrene (BaP), a potent carcinogen, has been proved that it has toxicological effects via activation the aryl hydrocarbon receptor (AhR) pathway. AhR can participate in regulating lipogenesis and lipolysis. This topic will verify whether BaP regulates lipid metabolism via AhR. Methods (1) C57BL/6 mice were gavaged with BaP for 12 weeks to detect serum lipids, glucose tolerance, and insulin resistance. Morphological changes in white adipose tissue (WAT) were detected by Hematoxylin and Eosin staining. The mRNA expression levels of adipogenesis-related factors included recombinant human CCAAT/enhancer binding protein alpha (C/EBPα), peroxisome proliferator-activated receptor gamma (PPARγ), and fatty acid binding protein 4 (FABP4) and inflammatory factors included nuclear factor kappa-B (NF-κB), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor alpha (TNF-α) were detected using PCR. (2) Neutral lipid content changes in differentiated 3 T3-L1 adipocytes treated with BaP with and w/o AhR inhibitor were detected by Oil red staining. The protein expression levels of adipogenesis- and decomposition-related factors included PPARγ coactivator-1 alpha (PGC-1α), and peroxisome proliferation-activated receptor alpha (PPARα) were detected using western blotting. The mRNA expression levels of inflammatory factors were detected using PCR. Results (1) BaP inhibited body weight gain, decreased lipid content, increased lipid levels, and decreased glucose tolerance and insulin tolerance in mice; (2) BaP reduced the expressions of C/EBPα, PPARγ, FABP4, PGC-1α, and PPARα and increased the expressions of NF-κB, MCP-1, and TNF-α by activating AhR. Conclusion BaP inhibit fat synthesis and oxidation while inducing inflammation by activating AhR, leading to WAT dysfunction and causing metabolic complications.

Background: The outbreak of severe respiratory syndrome coronavirus 2 (SARS-COV-2) has led to long periods of social isolation for individuals across the world. Although medical students generally have a high prevalence of mental health problems, they have received less attention than other groups concerning the impact of SARS-COV-2. Therefore, the present study investigated the mental health status, risk factors, and protective factors for mental health problems in medical students in North China during the SARS-COV-2 pandemic.Methods: A WeChat-based survey, which included the Depression Anxiety Stress Scale-21 and measures of social demographics, was performed twice. Risk and protective factors were identified by binary logistic regression analysis.Results: A total of 702 effective questionnaires were collected in two separate surveys. In total, 24.55% of medical students were suffering anxiety to different degrees of severity, 13.18% were suffering depression in the first survey, and 3.71% wanted to give up working in primary medical care during the SARS-COV-2 pandemic in the second survey. In contrast, during the SARS-COV-2 pandemic, a risk factor for anxiety and depression was gender which is male, while being knowledgeable about the SARS-COV-2 pandemic and having a lower academic burden were both protective factors.Conclusions: Measures are required to prevent increases in mental health problems in medical students. Our findings suggest that increasing knowledge about the SARS-COV-2 pandemic and reducing academic burden in medical students is extremely important during the SARS-COV-2 pandemic.