This study aimed to evaluate whether (-)-epigallocatechin-3-gallate (EGCG) alleviates hepatic responses to lipopolysaccharide (LPS)-induced inflammation and oxidation. Isolated bovine hepatocytes and BALB/c mice were used for LPS challenge and EGCG pretreatment experiments in vitro and in vivo. LPS-challenged (6 μg/mL) hepatocytes exhibited increased levels of NF-κB (p65 and IκBα) and MAPK (p38, ERK, JNK) phosphorylation as well as increased binding activity of p65 to target pro-inflammatory gene promoters, and these effects were suppressed by pretreatment with 50 μM EGCG. Moreover, the reduction in Nrf2 signaling and antioxidant enzyme activities induced by LPS stimulation were reversed upon EGCG treatment. In vivo experiments demonstrated the protective role of EGCG in response to GalN/LPS-induced mortality and oxidative damage. Together, our results suggest that EGCG is hepatoprotective via inhibition of MAPK/NF-κB signaling and activation of the Nrf2 cascade. This information might help design strategies for counteracting hepatitis in ruminants and monogastric animals.

Escherichia coli (E. coli) is one of the main causative agents of mastitis in dairy cows. Lycium barbarum polysaccharide (LBP) has a variety of physiological effects as it has antioxidants, it is hypoglycemic, it has anti-aging properties, it is neuroprotective, immune boosting, and it has anti-inflammatory effects in vivo and in vitro. In this study, we examined whether LBP affects the expression of pro-inflammatory factors, and the mitogen-activated protein kinase (MAPK) signaling pathway via activation of the suppressor of cytokine signaling-3 (SOCS3) in E. coli-induced primary bovine mammary epithelial cell (pbMEC) inflammatory responses. The experiment was designed with the control group (NC), cells were treated with E. coli for 6 h as the E. coli group (E. coli), and cells were pretreated with 100 μg/mL or 300 μg/mL of LBP for 24 h, followed by the addition of E. coli for 6 h as the E. coli + low level (E + LL) or E. coli + high level (E + HL) groups. The addition of LBP did not alter the cell viability of pbMEC in a dose-dependent assay. Pretreatment with LBP significantly decreased the expression of pro-inflammatory genes (IL1B, MAPK14, COX-2, iNOS) and proteins (COX-2, IL-1β, TNF-α) in the cells challenged by E. coli as compared with the control group (p < 0.05). E. coli stimulation significantly increased the production of reactive oxygen species (ROS) and malondialdehyde (MDA) in pbMEC, and decreased the antioxidants’ capacity with regard to decreased superoxide dismutase (SOD) and total antioxidant capacity (T-AOC); however, pretreatment with LBP reversed the oxidative stress and inhibition of antioxidants in cells challenged by E. coli. Moreover, LBP reversed the upregulated expression of the components of the MAPK pathway (increased phosphorylation level of p38, JNK, and ERK), followed by E. coli stimulation. Consistently, cells exposed to E. coli strengthened the staining of p38, whereas pretreatment of LBP weakened the staining of p38 in cells challenged by E. coli. Notably, the expression of SOCS3 was increased by LBP added to the cells in a dose-dependent manner. Additionally, the level of decreased expression of proinflammatory factors (IL-1β, TNF-α, and COX-2) was higher in the E + LL group than in the E + HL group. These results indicate that LBP pretreatment is effective in the alleviation of E. coli-induced inflammatory and oxidative responses in pbMEC through activation of SOCS3 and depression of MAPK signaling. As such, this might help us to develop molecular strategies for mitigating the detrimental effects of clinical bovine mastitis.

Pyocyanin (PCN) is an extracellular toxin secreted by Pseudomonas aeruginosa (PA), which has redox capacity and disrupts the redox balance of host cells, affecting cell function and leading to cell death. The aim of this experiment was to compare the degree of apoptosis, inflammation, and oxidative stress of bovine mammary epithelium cells (bMECs) induced by lipopolysaccharide (LPS) and pyocyanin (PCN) and to examine whether PCN can promote the apoptosis, inflammation, and oxidative stress of bMECs induced by LPS. In this study, 1 µg/mL LPS and 1 µg/mL PCN were finally selected for subsequent experiments through dose-dependent experiments. In this study, cells were not given any treatment and were used as the control group (NC). The cells were treated with PCN or LPS individually for 6 h as the PCN group (PCN) or the LPS group (LPS), and the combination of LPS and PCN challenge for 6 h as the LPS + PCN (LPS + PCN) group. Compared with the control and LPS groups, PCN resulted in a significantly upregulated expression of genes related to pro-inflammatory (IL-6, TNF-α, MyD88), apoptotic (Bax, Caspase3, Caspase9), as well as protein expression of components in the TLR4/NF-κB signaling pathway (TLR4, p-p65, p65), and p53 signaling pathway (p-p53, p53, Caspase9) (p < 0.05). Moreover, the expression of genes and proteins was significantly upregulated after PCN treatment combined with LPS compared to either LPS or PCN challenge alone (p < 0.05). The stimulation of PCN combined with LPS significantly increased reactive oxygen species (ROS) and malondialdehyde (MDA) production in bovine mammary epithelial cells (bMECs), as well as decreased glutathione peroxidase (GSH-Px) and total antioxidant capacity (T-AOC). Moreover, cells in the LPS + PCN group aggravated oxidative stress and antioxidant inhibition in cells. In addition, the expression of the corresponding genes and proteins related to the Nrf2 pathway (Nrf2, HO-1) was significantly down-regulated in the PCN group as compared to the control group (p < 0.05). Altogether, PCN stimulation exacerbates inflammatory reactions, apoptosis, and oxidative stress reactions, as well as when combined with LPS challenge in bMECs. Therefore, this study indicates that PCN manifests a role in promoting apoptosis, inflammation, and oxidative stress and interacting with LPS to enhance more serious biological stress responses.

Milk production traits are the most important quantitative economic traits in dairy cow production; improving the yield and quality of milk is an important way to ensure the production efficiency of the dairy industry. This study carried out a series of in-depth statistical genetics studies and molecular analyses on the Chinese Holstein cows in the Jiangsu Province, such as descriptive statistics and copy number variation analysis. A genetic correlation, phenotypic correlation, and descriptive statistical analysis of five milk production traits (milk yield, milk fat percentage, milk fat yield, milk protein percentage, and milk protein yield) of the dairy cows were analyzed using the SPSS and DMU software. Through quality control, 4173 cows and their genomes were used for genomic study. Then, SNPs were detected using DNA chips, and a copy number variation (CNV) analysis was carried out to locate the quantitative trait loci (QTL) of the milk production traits by Perl program software Penn CNV and hidden Markov model (HMM). The phenotypic means of the milk yield, milk fat percentage, milk fat mass, milk protein percentage, and milk protein mass at the first trimester were lower than those at the other trimesters by 8.821%, 1.031%, 0.930%, 0.003%, and 0.826%, respectively. The five milk production traits showed a significant phenotypic positive correlation (p < 0.01) and a high genetic positive correlation among the three parities. Based on the GGPBovine 100 K SNP data, QTL-detecting research on the fist-parity milk performance of dairy cows was carried out via the CNV. We identified 1731 CNVs and 236 CNVRs in the 29 autosomes of 984 Holstein dairy cows, and 19 CNVRs were significantly associated with the milk production traits (p < 0.05). These CNVRs were analyzed via a bioinformatics analysis; a total of 13 gene ontology (GO) terms and 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly enriched (p < 0.05), and these terms and pathways are mainly related to lipid metabolism, amino acid metabolism, and cellular catabolic processes. This study provided a theoretical basis for the molecular-marker-assisted selection of dairy cows by developing descriptive statistics on the milk production traits of dairy cows and by locating the QTL and functional genes that affect the milk production traits of first-born dairy cows. The results describe the basic status of the milk production traits of the Chinese Holstein cows in Jiangsu and locate the QTL and functional genes that affect the milk production traits of the first-born cows, providing a theoretical basis for the molecular-marker-assisted selection of dairy cows.