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The unfolded protein response (UPR) is an evolutionarily conserved pathway that senses and responds to the accumulation of misfolded proteins in the endoplasmic reticulum (ER) lumen during bacterial infection. The IRE-1/XBP-1 pathway is a major branch of the UPRER that has been conserved from yeast to human. Dioscin, a steroidal saponin exhibits a broad spectrum of properties. However, whether dioscin influences the immune response and the underlying molecular mechanisms remain obscure. We find that dioscin increases resistance to Gram-negative pathogen Pseudomonas aeruginosa. Furthermore, dioscin also inhibits the growth of pathogenic bacteria. Meanwhile, dioscin enhances the resistance to pathogens by reducing bacterial burden in the intestine. Through genetic screening, we find that dioscin activates the UPRER to promote innate immunity via IRE-1/XBP-1 pathway. Intriguingly, dioscin requires the neural XBP-1 for immune response. Our findings suggest that dioscin may be a viable candidate for the treatment of infectious diseases. [ABSTRACT FROM AUTHOR]

Mutations in MC4R are the most common genetic cause of obesity. In the reported Chinese morbid obesity cohort, 10 out of 59 harbor six MC4R variants, including Y35C, T53I, V103I, R165W, G233S, and C277X, among which V103I has a relatively high frequency, while other five variants are rare in the population. The prevalence of MC4R carriers in Chinese morbid obese patients (body mass index ≥ 45 kg m−2) is detected as 16.9% in this study. R165W and C277X are loss‐of‐function variants. The patient with R165W achieves excess weight loss (%EWL) as high as 20.6% and 50.3% at 1 and 8 months after surgery, respectively. G233S is reported for the first time in Asia obese population. The patient harboring G233S has a %EWL as 23.3% one month postsurgery. It is concluded that morbid obese patients with rare MC4R variants can benefit from metabolic surgery. More importantly, the choice of surgery procedure and MC4R variant should be taken into consideration for personalized treatment. In the future, a larger size cohort, accompanied with regular and longer follow‐up, would be helpful. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is a frequently occurring malignant gastrointestinal cancer. The 5-year survival rate of HCC is still below 8%, and thus, identifying more effective therapeutic methods is needed. Here, we evaluated the effects of Stigmast-4-en-6β-ol-3-one (S463) on the viability and colony formation of liver cancer cells. S463 treatment decreased the viability and induced apoptosis and ferroptosis in liver cancer cells, and also increased cellular malondialdehyde (MDA) and lipid peroxidation levels. In S463 treated cells, the expression level of Bax was increased, and the expression level of GPX4 was reduced, and the cleavage of PARP was improved. We also found that S463 treatment downregulated E2F1 and upregulated p53 at both the mRNA and protein levels. Importantly, rescue experiments revealed that overexpression of E2F1 partially restored S463-induced Bax and p53 upregulation and GPX4 downregulation and counteracted the S463-induced decrease in cell viability and colony formation and the S463-induced increase in MDA and lipid peroxidation levels. Our findings suggest that S463 significantly inhibits viability and colony formation and induces apoptosis and ferroptosis in liver cancer cells via E2F1. [ABSTRACT FROM AUTHOR]

Nocardia farcinica is an opportunistic pathogen that causes nocardiosis primarily in patients with compromised immune systems. In this study, we used the genetically tractable organism Caenorhabditis elegans as a model to study the innate immune responses to N. farcinica infection. We found that unlike other pathogenic bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus, N. farcinica failed to kill adult worms. In another words, adult worms exposed to N. farcinica exhibited a normal lifespan, compared with those fed the standard laboratory food bacterium Escherichia coli OP50. Interestingly, deletion of three core genes (pmk-1, nsy-1 and sek-1) in the p38 MAPK/PMK-1 pathway reduced the survival of worm exposure to N. farcinica, highlighting a crucial role of this pathway for C. elegans in resistance to N. farcinica. Furthermore, our results revealed that N. farcinica exposure up-regulated the level of PMK-1 phosphorylation. The activation of PMK-1 promoted nuclear translocation of a transcription factor SKN-1/Nrf2, which in turn mediated N. farcinica infection resistance in C. elegans. Our results provide an excellent example that the integrity of immune system is key aspect for counteract with pathogenesis of N. farcinica. [ABSTRACT FROM AUTHOR]