As a traditional Chinese rice wine, Hong Qu glutinous rice wine (HQW) is popular among consumers due to its unique flavor. However, its quality changes during fermentation, and the potential relationships between flavor and microbes have not been systematically researched. In this work, physicochemical properties (pH, total sugar, alcohol, amino acid nitrogen), flavor compounds (organic acids, free amino acids, and volatile compounds), and microbial communities were investigated. The results revealed that Pantoea, Lactiplantibacillus, Lactobacillus, Leuconostoc, and Weissella predominated the bacterial genera, and Monascus was the predominant fungal genus. Organic acids, free amino acids, and key volatile compounds (esters and alcohols) significantly increased during fermentation. The correlations analysis showed that Lactiplantibacillus was closely associated with flavor compounds formation. This study deepens our understanding of the roles of microorganisms in flavor formation on traditional HQW fermentation.

Growth and differentiation factor 15 (GDF-15) has been studied as an important hallmark of cancer. However, the receptor of GDF-15 in pancreatic cancer cell remains unclear. Here, we investigated its biological effects in pancreatic ductal adenocarcinoma (PDAC). We found that aberrant GDF-15 expression positively correlated with poor survival of PDAC patients. GDF-15 protein enhanced tumor cell proliferation in two pancreatic cancer lines, AsPC-1 and BxPC-3. Knockdown GDF-15 attenuated its biological function in vitro and reduced PDAC cell tumorigenesis upon xenotransplantation into nude mice. Moreover, we identified that glial-derived neurotropic factor family receptor α-like (GFRAL) was upregulated in PDAC tissues and positively correlated with GDF-15 expression. High GFRAL expression was significantly associated with poor survival in PDAC patients. Furthermore, we identified that the biological effects of GDF-15 are mediated by its receptor GFRAL which is present in PDAC cells. After overexpression GFRAL in pancreatic cancer cells, the effect of GDF-15 was significantly enhanced. Overall, our findings demonstrated that the GDF-15 secreted by PDAC cells, binds to GFRAL, itself localized in PDAC cells, to promote cancer cell growth and metastasis through the GDF-15/GFRAL signaling pathway.

The objective of this study was to determine the oxidative stability and proteome profile of dorsal muscle of frozen obscure pufferfish subjected to repeated freeze–thaw cycles (FTC). Twenty frozen fish were filleted (2 cm × 2 cm × 2 cm) and subjected to FTC. Protein oxidation, lipid oxidation, antioxidant enzyme activities (AEA), and proteome profile were assessed. The results showed that the carbonyl content and TBARS value increased (p < .05), while sulfhydryl content and AEA decreased (p < .05) as FTC increased. SDS-PAGE analysis revealed that FTC induced significant alterations in disulfide linkage and fragments. There were significant (p < .05) correlations between lipid oxidation, AEA, and protein oxidation. A total of 19 differentially abundant proteins were identified, of which L-lactate dehydrogenase and other proteins could be potential biomarkers for pufferfish subjected to FTC. Bioinformatic analysis revealed that these proteins are mainly involved in membrane structure, respiratory chain, and apoptosis. Practical applications Pufferfish is popular in many Asian countries for its palatable flavor and frozen storage is the most common way for its preservation. However, repeated freeze–thaw cycles (FTC) remain a core issue in frozen products, which lead to various changes in protein and consequently have a serious impact on food quality. In this study, the extent of protein oxidation (PO) and proteomic changes in pufferfish muscle subjected to FTC was investigated. The initiation of PO correlates with increased lipid oxidation and decreased antioxidant enzyme activity, which may be used to control the PO. The differentially abundant proteins identified may be used to distinguish the frozen products subjected to different FTC. Understanding the molecular mechanism of protein changes induced by FTC will enable us to achieve the target-control and to preserve the frozen aquatic products with better quality.