ALG5 Regulates STF-62247-Induced Milk Fat Synthesis via the mTOR Signaling Pathway.

Milk fat content is a critical indicator of milk quality. Exploring the key regulatory genes involved in milk fat synthesis is essential for enhancing milk fat content. STF-62247 (STF), a thiazolamide compound, has the potential to bind with ALG5 and upregulate lipid droplets in fat synthesis. However, the effect of STF on the process of milk fat synthesis and whether it acts through ALG5 remains unknown. In this study, the impact of ALG5 on milk fat synthesis and its underlying mechanism were investigated using bovine mammary epithelial cells (BMECs) and mouse models through real-time PCR, western blotting, Oil Red O staining, and triglyceride analysis. Experimental findings revealed a positive correlation between STF and ALG5 with the ability to synthesize milk fat. Silencing ALG5 led to decreased expression of FASN, SREBP1, and PPARγ in BMECs, as well as reduced phosphorylation levels in the PI3K/AKT/mTOR signaling pathway. Moreover, the phosphorylation levels of the PI3K/AKT/mTOR signaling pathway were restored when ALG5 silencing was followed by the addition of STF. These results suggest that STF regulates fatty acid synthesis in BMECs by affecting the PI3K/AKT/mTOR signaling pathway through ALG5. ALG5 is possibly a new factor in milk fat synthesis.

MSI2 Modulates Unsaturated Fatty Acid Metabolism by Binding FASN in Bovine Mammary Epithelial Cells.

The regulation of fatty acid metabolism is crucial for milk flavor and quality. Therefore, it is important to explore the genes that play a role in fatty acid metabolism and their mechanisms of action. The RNA-binding protein Musashi2 (MSI2) is involved in the regulation of numerous biological processes and plays a regulatory role in post-transcriptional translation. However, its role in the mammary glands of dairy cows has not been reported. The present study examined MSI2 expression in mammary glands from lactating and dry milk cows. Experimental results in bovine mammary epithelial cells (BMECs) showed that MSI2 was negatively correlated with the ability to synthesize milk fat and that MSI2 decreased the content of unsaturated fatty acids (UFAs) in BMECs. Silencing of Msi2 increased triglyceride accumulation in BMECs and increased the proportion of UFAs. MSI2 affects TAG synthesis and milk fat synthesis by regulating fatty acid synthase (FASN). In addition, RNA immunoprecipitation experiments in BMECs demonstrated for the first time that MSI2 can bind to the 3'-UTR of FASN mRNA to exert a regulatory effect. In conclusion, MSI2 affects milk fat synthesis and fatty acid metabolism by regulating the triglyceride synthesis and UFA content through binding FASN.

WITHDRAWN: RNA binding protein Musashi2 regulates dairy cows' mastitis by activating the TGFß signaling pathway.

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Allicin Alleviated LPS-Induced Mastitis via the TLR4/NF-κB Signaling Pathway in Bovine Mammary Epithelial Cells.

Dairy farming is the most important economic activity in animal husbandry. Mastitis is the most common disease in dairy cattle and has a significant impact on milk quality and yield. The natural extract allicin, which is the main active ingredient of the sulfur-containing organic compounds in garlic, has anti-inflammatory, anticancer, antioxidant, and antibacterial properties; however, the specific mechanism underlying its effect on mastitis in dairy cows needs to be determined. Therefore, in this study, whether allicin can reduce lipopolysaccharide (LPS)-induced inflammation in the mammary epithelium of dairy cows was investigated. A cellular model of mammary inflammation was established by pretreating bovine mammary epithelial cells (MAC-T) with 10 µg/mL LPS, and the cultures were then treated with varying concentrations of allicin (0, 1, 2.5, 5, and 7.5 µM) added to the culture medium. MAC-T cells were examined using RT-qPCR and Western blotting to determine the effect of allicin. Subsequently, the level of phosphorylated nuclear factor kappa-B (NF-κB) was measured to further explore the mechanism underlying the effect of allicin on bovine mammary epithelial cell inflammation. Treatment with 2.5 µM allicin considerably decreased the LPS-induced increase in the levels of the inflammatory cytokines interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) and inhibited activation of the NOD-like receptor protein 3 (NLRP3) inflammasome in cow mammary epithelial cells. Further research revealed that allicin also inhibited the phosphorylation of inhibitors of nuclear factor kappa-B-α (IκB-α) and NF-κB p65. In mice, LPS-induced mastitis was also ameliorated by allicin. Therefore, we hypothesize that allicin alleviated LPS-induced inflammation in the mammary epithelial cells of cows probably by affecting the TLR4/NF-κB signaling pathway. Allicin will likely become an alternative to antibiotics for the treatment of mastitis in cows.

Effect of season on slaughter performance, meat quality, muscle amino acid and fatty acid composition, and metabolism of pheasants (Phasianus colchicus).

This study aimed to investigate the effect of summer and winter on slaughter performance, muscle quality, flavor-related substance content, and gene expression levels related to the fat metabolism of pheasants. One-hundred 1-day-old pheasants were fed for 5 months starting in March and July and then, respectively, slaughtered in summer (August) and winter (December). The results revealed that compared with summer, winter not only increased pheasant live weight, dressed percentage, full-eviscerated yield, and muscle yield (p < 0.05) but also enhanced the activities of SOD and CAT in serum (p < 0.05). Winter significantly increased meat color, the contents of inosinic acid, and flavor amino acid in muscle. Amino acid contents in leg muscles of pheasants in winter were significantly higher than in summer except for histidine (p < 0.05). Winter increased the contents of muscle mono-unsaturated fatty acid, reducing saturated fatty acid. Summer improved fat synthesis in liver, promoted the deposition of triglycerides and cholesterol, and reduced the expression levels of fat metabolism-related genes in muscle, while winter increased the expression levels of genes related to muscle fat metabolism to provide energy for body and affect muscle fatty acid profile. Overall, pheasants fed in winter had better sensory quality and flavor than summer.