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Pinctada martensii is a major marine pearl cultured species in southern China, and its meat is rich in protein, which is an excellent material for the preparation of bioactive peptides. In this study, the peptides from Pinctada martensii meat were prepared by simulated gastrointestinal hydrolysis, and after multistep purification, the structures of the peptides were identified, followed by the solid-phase synthesis of the potential antioxidant peptides. Finally, the antioxidant activities of the peptides were verified using HepG2 cells, whose oxidative stress was induced by hydrogen peroxide (H2O2). It was shown that the antioxidant peptide (S4) obtained from Pinctada martensii meat could significantly increase the cell viability of HepG2 cells. S4 could also scavenge reactive oxygen species (ROS) and reduce the lactate dehydrogenase (LDH) level. In addition, it could enhance the production of glutathione (GSH) and catalase (CAT) in HepG2 cells, as well as the expression of key genes in the Nrf2 signaling pathway. Three novel antioxidant peptides, arginine–leucine (RL), arginine–glycine–leucine (RGL), and proline–arginine (PR), were also identified. In conclusion, peptides from Pinctada martensii meat and three synthetic peptides (RGL, RL, PR) showed antioxidant activity and could have the potential to be used as antioxidant candidates in functional foods. [ABSTRACT FROM AUTHOR]

Hemolin is a distinctive immunoglobulin superfamily member involved in invertebrate immune events. Although it is believed that hemolin regulates hemocyte phagocytosis and microbial agglutination in insects, little is known about its contribution to the humoral immune system. In the present study, we focused on hemolin in Antheraea pernyi ( Ap -hemolin) by studying its pattern recognition property and humoral immune functions. Tissue distribution analysis demonstrated the mRNA level of Ap -hemolin was extremely immune-inducible in different tissues. The results of western blotting and biolayer interferometry showed recombinant Ap -hemolin bound to various microbes and pathogen-associated molecular patterns. In further immune functional studies, it was detected that knockdown of hemolin regulated the expression level of antimicrobial peptide genes and decreased prophenoloxidase activation in the A. pernyi hemolymph stimulated by microbial invaders. Together, these data suggest that hemolin is a multifunctional pattern recognition receptor that plays critical roles in the humoral immune responses of A. pernyi ., Competing Interests: Author YL is employed by Liaoning Applos Biotechnology Co. Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 He, Zhou, Cai, Liu, Zhao, Zhang, Wang and Zhang.)

Experimental studies using synthetic peptides identical to the bcr-abl fusion region in chronic myeloid leukemia (CML) patients have revealed that some specific peptides could bind to human leukocyte antigen (HLA) class I and class II molecules. Previous clinical observations have also reported some significant HLA associations with the development of CML in their populations. Due to high diversity of HLA alleles, the present study assessed the possibility of an association of HLA molecules in CML patients living in Jiangsu province, the eastern part of China. HLA-A, B and DRB1 allele distributions in 295 CML patients (aged 4 - 65 years) were analysed and compared with unrelated healthy hematopoietic stem cell donors from the same ethnic and geographic background. By comparison of the HLA gene distribution characteristics between CML and healthy donor populations, differences with statistical significance were found in HLA-A*30 (5.42% versus 9.13%) with odds ratio (OR) 0.57, DRB1*07 (8.14% versus 12.51%; OR = 0.62), and B*81 (0.51% versus 0.09%, OR = 5.44). These results suggest that expression of HLA-A*30, DRB1*07 might imply a protective effect on CML acquisition, while B*81 might be associated with CML susceptive factors in our population. [ABSTRACT FROM AUTHOR]