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Glucose plays a vital part in milk protein synthesis through the mTOR signaling pathway in bovine mammary epithelial cells (BMEC). The objectives of this study were to determine how glucose affects hexokinase (HK) activity in BMEC and investigate the regulatory effect of HK in kappa casein (CSN3) synthesis via the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway in BMEC. For this, HK1 and HK2 were knocked out in BMEC using the CRISPR/Cas9 system. The gene and protein expression, glucose uptake, and cell proliferation were measured. We found that glucose uptake, cell proliferation, CSN3 gene expression levels, and expression of HK1 and HK2 increased with increasing glucose concentrations. Notably, glucose uptake was significantly reduced in HK2 knockout (HK2KO) BMEC treated with 17.5 mM glucose. Moreover, under the same glucose treatment conditions, the proliferative ability and abundance of CSN3 were significantly diminished in both HK1 knockout (HK1KO) and HK2KO BMEC compared with that in wild-type BEMC. We further observed that the phosphorylation levels of ribosome protein subunit 6 kinase 1 (S6K1) were reduced in HK1KO and HK2KO BMEC following treatment with 17.5 mM glucose. As expected, the levels of glucose-6-phosphate and the mRNA expression levels of glycolysis-related genes were decreased in both HK1KO and HK2KO BMEC following glucose treatment. These results indicated that the knockout of HK1 and HK2 inhibited cell proliferation and CSN3 expression in BMEC under glucose treatment, which may be associated with the inactivation of the S6K1 and inhibition of glycolysis.

The objective of this study was to determine the role of SLC15A4 in the muramyl dipeptide (MDP)-mediated inflammatory response of bovine rumen epithelial cells (BRECs). First, changes in the mRNA expression of pro-inflammatory factor genes in BRECs following 10 μg mL–1 MDP treatments were examined. RT-qPCR results showed that the expression of pro-inflammatory factor (IL-1β, IL-6, and TNF-α) mRNAs were significantly increased under MDP stimulation (P

This experiment investigated the effects of different levels of bile acid (BA) additives in diets on the lactation performance, serum antioxidant metabolites, and serum biochemical indices of 60 multiparous mid-lactation dairy cows. The cows were randomized to receive one of the four homogeneous treatments, with the BA preparation supplemented at 0, 6, 12, and 18 g/head/d. The experiment lasted for 14 weeks. The first 2 weeks were the pre-feeding period. The milk yield and composition data were recorded weekly, and the dry matter intake and antioxidative blood index were analyzed on the 6th, 10th, and 14th weeks of the study. On the 84th day of the experiment, the experimental group exhibited significantly higher levels of total protein and albumin, by 57.5% and 55.6%, respectively, compared to the control group (p < 0.05). On both the 28th and 84th days of the trial, the experimental group showed a markedly higher lipase content compared to the control group, by 26.5% and 25.2%, respectively (p < 0.05). Furthermore, the experimental group displayed notably elevated levels of superoxide dismutase, glutathione peroxidase, and total antioxidant capacity, surpassing the control group by 17.4%, 21.6%, and 8.7%, respectively. In conclusion, BA additives improve the serum antioxidant indices of dairy cows, thereby enhancing the performance of these cows.

Acute diarrhoea and intestinal inflammation represent one of the most prevalent clinical disorders of milk production, resulting in enormous annual financial damage for the dairy sector. In the context of an unsatisfactory therapeutic effect of antibiotics, the natural products of plants have been the focus of research. Quercetin is an important flavonoid found in a variety of plants, including fruits and vegetables, and has strong anti-inflammatory effects, so it has received extensive attention as a potential anti-inflammatory antioxidant. However, the underlying basis of quercetin on inflammatory reactions and oxidative tension generated by lipopolysaccharide (LPS) in bovine intestinal epithelial cells (BIECs) is currently unexplained. This research aimed to determine the influence of quercetin on LPS-induced inflammatory reactions, oxidative tension, and the barrier role of BIECs. Our findings demonstrated that BIEC viability was significantly improved in LPS-treated BIEC with 80 μg/mL quercetin compared with the control group. Indicators of oxidative overload and genes involved in barrier role revealed that 80 μg/mL quercetin efficiently rescued BIECs from oxidative and barrier impairment triggered by 5 μg/mL LPS. In addition, the mRNA expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6, as well as chemokines CXCL2, CXCL5, CCL5, and CXCL8, was diminished in LPS-treated BIECs with 80 μg/mL quercetin compared with LPS alone. Furthermore, the mRNA expression of toll-like receptor 4 (TLR4), CD14, myeloid differential protein-2 (MD2), and myeloid differentiation primary response protein (MyD88) genes associated with the TLR4 signal mechanism was markedly reduced by the addition of quercetin to LPS-modulated BIECs, indicating that quercetin can suppress the TLR4 signal mechanism. We performed Western blotting on the NF-κB signalling mechanism and compared it with immunofluorescence to further corroborate this conclusion. The LPS treatment enhanced the proportions of p-IκBα/GAPDH and p-p65/GAPDH. Compared with the LPS-treated group, quercetin administration decreased the proportions of p-IκBα/GAPDH and p-p65/GAPDH. In addition, immunofluorescence demonstrated that quercetin greatly reduced the LPS-induced nuclear translocation of NF-κB p65 in BIECs. The benefits of quercetin on inflammatory reactions in LPS-induced BIECs may be a result of its capacity to inhibit the TLR4-mediated NF-κB signalling mechanism. These findings suggest that quercetin can be used as an anti-inflammatory reagent to treat intestinal inflammation induced by LPS release.

Glucose and amino acids are important sources of nutrients in the synthetic milk of dairy cows, and understanding the fate of amino acids is essential to optimize the utilization of amino acids in milk protein synthesis, thereby reducing nutrient inefficiencies during lactation. The purpose of this study was to investigate the effects of LPS and different concentrations of glucose on (1) the expression of inflammatory factors and genes, (2) the glucose metabolism, and (3) amino acid utilization in BMECs. The results showed that there was an interaction (LPS × glucose, p < 0.05) between LPS and glucose content in the inflammatory cytokine genes (IL-6 and TNF-α) and the inflammatory regulatory genes (CXCL2, CXCL8, and CCL5). With the addition of LPS, the HG + LPS group caused downregulated (p < 0.05) expression of IL-6 and TNF-α, compared with the LG + LPS group. Interestingly, compared with the LG + LPS group, the HG + LPS group upregulated (p < 0.05) the expression of CXCL2, CXCL8, and CCL5. LPS supplementation increased (p = 0.056) the consumption of glucose and GLUT1 gene expression (p < 0.05) and tended to increase (p = 0.084) the LDHA gene expression of BMECs under conditions of different concentrations of glucose culture. High glucose content increased (p < 0.001) the consumption of glucose and enhanced (p < 0.05) the GLUT1, HK1, HK2, and LDHA gene expression of BMECs with or without LPS incubation, and there was an interaction (LPS × glucose, p < 0.05) between LPS and glucose concentrations in GLUT1 gene expression. In this study, LPS enhanced (p < 0.05) the consumption of amino acids such as tryptophan, leucine, isoleucine, methionine, valine, histidine, and glutamate, while high levels of glucose decreased (p < 0.01) consumption, except in the case of tyrosine. For histidine, leucine, isoleucine, and valine consumption, there was an interaction (LPS × glucose, p < 0.05) between LPS and glucose levels. Overall, these findings suggest that relatively high glucose concentrations may lessen the LPS-induced BMEC inflammatory response and reduce amino acid consumption, while low glucose concentrations may increase the demand for most amino acids through proinflammatory responses.

Excessive lipid mobilization will snatch cell membrane lipids in postpartum dairy cows, which may impair the function of immune cells, including peripheral mononuclear cells (PBMCs) and polymorphonuclear granulocytes (PMNs). Acetate, as a precursor and the energy source of milk fat synthesis, plays a key role in lipid synthesis and the energy supply of dairy cows. However, there is little information about the effect of sodium acetate (NaAc) on the immune function of PBMC and PMN in postpartum dairy cows. Therefore, this study aimed to evaluate the effects of NaAc on the immune functions of PBMCs and PMNs in postpartum dairy cows. In this experiment, twenty-four postpartum multiparous Holstein cows were randomly selected and divided into a NaAc treatment group and a control group. Our results demonstrated that the dietary addition of NaAc increased (p < 0.05) the number of monocytes and the monocyte ratio, suggesting that these postpartum cows fed with NaAc may have better immunity. These expressions of genes (LAP, XBP1, and TAP) involved in the antimicrobial activity in PBMCs were elevated (p < 0.05), suggesting that postpartum dairy cows supplemented with NaAc had the ability of antimicrobial activity. In addition, the mRNA expression of the monocarboxylate transporters MCT1 and MCT4 in PBMCs was increased (p < 0.05) in diets supplemented with NaAc in comparison to the control. Notably, the expression of the XBP1 gene related to antimicrobial activity in PMN was upregulated with the addition of NaAc. The mRNA expression of genes (TLN1, ITGB2, and SELL) involved in adhesion was profoundly increased (p < 0.05) in the NaAc groups. In conclusion, our study provided a novel resolution strategy in which the use of NaAc can contribute to immunity in postpartum dairy cows by enhancing the ability of antimicrobial and adhesion in PBMCs and PMNs.

This study aimed to assess the effects of partially substituting soybean meal in the diet with slow-release urea (SRU) on the lactation performance, heat shock signal molecules, and environmental sustainability of heat-stressed lactating cows in the middle stage of lactation. In this study, 30 healthy Holstein lactating dairy cattle with a similar milk yield of 22.8 ± 3.3 kg, days in milk of 191.14 ± 27.24 days, and 2.2 ± 1.5 parity were selected and randomly allocated into two groups. The constituents of the two treatments were (1) basic diet plus 500 g soybean meal (SM) for the SM group and (2) basic diet plus 100 g slow-release urea and 400 g corn silage for the SRU group. The average temperature humidity index (THI) during the experiment was 84.47, with an average THI of >78 from day 1 to day 28, indicating the cow experienced moderate heat stress conditions. Compared with the SM group, the SRU group showed decreasing body temperature and respiratory rate trends at 20:00 (p < 0.1). The substitution of SM with SRU resulted in an increasing trend in milk yield, with a significant increase of 7.36% compared to the SM group (p < 0.1). Compared to the SM group, AST, ALT, and γ-GT content levels were significantly increased (p < 0.05). Notably, the levels of HSP-70 and HSP-90α were significantly reduced (p < 0.05). The SRU group showed significantly increased acetate and isovalerate concentrations compared with the SM group (p < 0.05). The prediction results indicate that the SRU group exhibits a significant decrease in methane (CH4) emissions when producing 1 L of milk compared to the SM group (p < 0.05). In summary, dietary supplementation with SRU tended to increase the milk yield and rumen fermentation and reduce plasma heat shock molecules in mid-lactation, heat-stressed dairy cows. In the hot summer, using SRU instead of some soybean meal in the diet alleviates the heat stress of dairy cows and reduces the production of CH4.

Subacute rumen acidosis (SARA) will cause an increase in endotoxin, which will have a negative effect on the bovine rumen epithelial cells (BREC). Flavonoids are effective in treating inflammation caused by endotoxin. Quercetin is a vital flavonoid widely occurring in fruits and vegetables and has received significant interest as a prospective anti-inflammatory antioxidant. Nonetheless, quercetin’s protective machinery against such damage to BREC induced by lipopolysaccharide (LPS) remains unclear. A combined quercetin and LPS-induced BREC inflammation model was utilized to elucidate the effect of quercetin protecting BREC from LPS-induced injury. After treating BREC with different doses of LPS (1, 5, and 10 μg/mL) for 6 h or 24 h, the mRNA expression of inflammatory factors was detected. Our experimental results show the establishment of the BREC inflammation model via mRNA high expression of pro-inflammatory cytokines in BREC following 6 h treatment with 1 µg/mL LPS. The promotive effect of 80 μg/mL quercetin on BREC growth via the cell counting kit-8 (CCK8) assay was observed. The expression of pro-inflammatory cytokines and chemokines, notably tumor necrosis factor α (TNF-α), Interleukin 1β (IL-1β), IL-6, CC-motif chemokine ligand 2 (CCL2), CCL20, CCL28, and CXC motif chemokine 9 (CXCL9), etc., was significantly reduced by quercetin supplementation. We also analyzed the mRNA detection of related pathways by qRT-PCR. Our validation studies demonstrated that quercetin markedly curbed the mRNA expression of the toll-like receptor 4 (TLR4) and myeloid differentiation primary response protein (MyD88) and the nuclear factor-κB (NF-κB) in LPS-treated BREC. In addition, western blot result outcomes confirmed, as expected, that LPS significantly activated phosphorylation of p44/42 extracellular regulated protein kinases (ERK1/2) and NF-κB. Unexpectedly, this effect was reversed by adding quercetin. To complement western blot results, we assessed p-ERK1/2 and p-p65 protein expression using immunofluorescence, which gave consistent results. Therefore, quercetin’s capacity to bar the TLR4-mediated NF-κB and MAPK signaling pathways may be the cause of its anti-inflammatory effects on LPS-induced inflammatory reactions in BREC. According to these results, quercetin may be utilized as an anti-inflammatory medication to alleviate inflammation brought on by high-grain feed, and it also lays out a conceptual foundation regarding the development and utilization of quercetin in the later stage.

The primary product of rumen fermentation is acetic acid, and its sodium salt is an excellent energy source for post-partum cows to manage negative energy balance (NEB). However, it is unknown how adding sodium acetate (NAc) may affect the rumen bacterial population of post-partum cows. Using the identical nutritional total mixed ration (TMR), this research sought to characterize the impact of NAc supplementation on rumen fermentation and the composition of bacterial communities in post-partum cows. After calving, 24 cows were randomly assigned to two groups of 12 cows each: a control group (CON) and a NAc group (ACE). All cows were fed the same basal TMR with 468 g/d NaCl added to the TMR for the CON group and 656 g/d NAc added to the TMR for the ACE group for 21 days after calving. Ruminal fluid was collected before morning feeding on the last day of the feeding period and analyzed for rumen bacterial community composition by 16S rRNA gene sequencing. Under the identical TMR diet conditions, NAc supplementation did not change rumen pH but increased ammonia nitrogen (NH3-N) levels and microbial crude protein (MCP) concentrations. The administration of NAc to the feed upregulated rumen concentrations of total volatile fatty acids (TVFA), acetic, propionic, isovaleric and isobutyric acids without affecting the molar ratio of VFAs. In the two experimental groups, the Bacteroidota, Firmicutes, Patescibacteria and Proteobacteria were the dominant rumen phylum, and Prevotella was the dominant rumen genus. The administration of NAc had no significant influence on the α-diversity of the rumen bacterial community but upregulated the relative abundance of Prevotella and downregulated the relative abundance of RF39 and Clostridia_UCG_014. In conclusion, the NAc supplementation in the post-peripartum period altered rumen flora structure and thus improved rumen fermentation in dairy cows. Our findings provide a reference for the addition of sodium acetate to alleviate NEB in cows during the late perinatal period.

Bovine liver mainly utilizes the propionate as a gluconeogenic substrate to synthesize the glucose. However, the mechanism underlying the regulatory effects of propionate on the glucose production in bovine hepatocytes remains less known. Previous studies have demonstrated G protein-coupled receptor 41 (GPR41) as receptors for propionate. We hypothesized that propionate may regulate the glucose production by GPR41 in bovine hepatocytes. Therefore, the aim of the study was to investigate the regulatory effects of propionate and GPR41 on glucose production in bovine hepatocytes. Hepatocytes with GPR41 overexpression were incubated in the presence of either 0 or 3 mM propionate for 24 h. These results showed that the expression of phosphoenolpyruvate carboxykinase 2 (PCK2) and pyruvate carboxylase (PC) genes involved in gluconeogenesis was enhanced (P < 0.01) with propionate treatment. Remarkably, the addition of propionate promotes the glucose production in bovine hepatocytes. Expression of GPR41 was increased by the addition of propionate in bovine hepatocytes overexpressed GPR41 by overexpression plasmid AAV1 compared with the absence of propionate. Interestingly, expression of PCK2 was markedly attenuated in GPR41 overexpressed-hepatocytes with propionate. Importantly, overexpression of GPR41 attenuated glucose output in propionate-induced bovine hepatocytes. These findings revealed that GPR41 negatively regulates glucose production by downregulating the expression of PCK2 in propionate-induced bovine hepatocytes.

Bovine mastitis is one of the most common clinical diseases in dairy cows, causing huge economic losses to the dairy industry. Quercetin is an important flavonoid existing in many food resources, which has attracted widespread attention as a potential anti-inflammatory and antioxidant. However, the molecular mechanism of quercetin on inflammatory responses and oxidative stress in bovine mammary epithelial cells (BMECs) induced by lipopolysaccharide (LPS) remains unknown. The objective of this study was to investigate the effects of quercetin on inflammation responses, oxidative stress, and barrier function of BMEC induced by LPS. Our results showed that BMEC viability was not affected by treatment with 50 and 100 μg/ml of quercetin and 1 μg/ml of LPS compared with control group. The results of oxidative stress indicators and related genes of barrier function indicated that 100 μg/ml of quercetin effectively protected the BMECs from damage of oxidative and barrier induced by 1 μg/ml of LPS. Moreover, the messenger RNA (mRNA) expressions of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, and chemokines CXCL2, CXCL5, CCL5, and CXCL8 were markedly decreased in the LPS-treated bovine retinal endothelial cells (BRECs) with 100 μg/ml of quercetin relatively to LPS alone. More importantly, the mRNA expressions of toll-like receptor 4 (TLR4), CD14, myeloid differential protein-2 (MD2), and myeloid differentiation primary response protein (MyD88) genes involved in TLR4 signal pathway were significantly attenuated by the addition of quercetin in LPS-treated BMEC, suggesting that quercetin can inhibit the TLR4 signal pathway. In addition, immunocytofluorescence showed that quercetin significantly inhibited the nuclear translocation of NF-κB p65 in BMEC induced by LPS. Therefore, the protective effects of quercetin on inflammatory responses in LPS-induced BMEC may be due to its ability to suppress the TLR4-mediated NF-κB signaling pathway. These findings suggest that quercetin can be used as an anti-inflammatory reagent to treat mastitis induced by exogenous or endogenous LPS release.

The purpose of the study was to assess the recovery, immune function, and breeding efficiency of postpartum dairy cows fed Astragalus membranaceus (AM) as a feed additive. The experiment used a completely randomized design. Cows were randomly assigned to two groups: (1) Control group fed total mixed ration (TMR; CON group, n = 15); (2) AM group fed TMR and AM (AM group, n = 15). The AM group was fed 675 g/day. The experimental results showed that compared with the CON group. The breeding interval of the AM group of dairy cows had a tendency to shorten (0.05 < p < 0.1). Plasma viscosity (PV), Plasma fibrinogen (FIB), the red cell aggregation index (TRCAI), Calcitonin (CT), Immunoglobulin M (IgM), and Luteinizing hormone (LH) results of AM group showed a time-treatment interaction (p < 0.05). Furthermore, the result of the study revealed that feeding AM as feed additives to dairy cows during the postpartum period had positive effects on wound recovery, immune function, endocrine regulation, and breeding efficiency.

The increased use of antibiotics continues to pose a threat to public health because of the increasing concern of antibiotic residue. Tea tree oil (TTO) is an extract of the Australian plant Melaleuca alternifolia with anti-inflammatory and antioxidant properties. However, there is little information on TTO supplementation in the diet of finishing pigs. Hence, the present study aimed to investigate the effect of TTO supplemented diets on the growth performance, meat quality, serum biochemical indices, and antioxidant capacity of the finishing pigs. Our results showed that TTO supplementation increased (P < 0.05) the mRNA expression of insulin-like growth factors -I (IGFs-I), growth acceleration hormone (GH), and heart fatty acid-binding protein (H-FABP), while the mRNA expression of myostatin gene (MSTN), and calpain-1 (CAST) decreased by the TTO supplementation, compared with the control group. In addition, TTO supplementation increased (P < 0.05) serum alkaline phosphatase (ALP), immunoglobulin G (IgG), and IgM levels but decreased (P < 0.05) serum aspartate transaminase (AST) concentration, relative to the control group. In addition, we found that the live weight and intramuscular fat enhanced (P < 0.05) significantly, and muscle pH 24 min value, cooking loss, and shear force decreased (P < 0.05) dramatically in the TTO group. The TTO supplementation increased (P < 0.05) C18:2n6t concentration and decreased (P < 0.05) C12:0 and C16:0 concentration, relative to the control group. Dietary supplementation with TTO decreased (P < 0.05) malondialdehyde (MDA) and increased (P < 0.05) glutathione peroxidase (GSH-Px) activity in serum. These results indicated that TTO supplementation could improve immunity and antioxidant, carcass traits, the nutritional value of pork, and the antioxidant capacity of finishing pigs. Therefore, TTO has potential positive effects as a feed additive in the pig industry.

This study aimed to evaluate whether sodium butyrate (SB) attenuates the ruminal response to LPS-stimulated inflammation by activating GPR41 in bovine rumen epithelial cells (BRECs). We examined the SB regulation of GPR41 and its impact on LPS-induced inflammation using GPR41 knockdown BRECs. The LPS-induced BRECs showed increases in the expression of genes related to pro-inflammation and decreases in the expression of genes related to tight junction proteins; these were attenuated by pretreatment with SB. Compared with that in LPS-stimulated BRECs, the ratio of phosphorylated NF-κB (p65 subunit) to NF-κB (p65 subunit) and the ratio of phosphorylated IκBα to IκBα were suppressed with SB pretreatment. The LSB group abated LPS-induced apoptosis and decreased the expression of Bax, Caspase 3, and Caspase 9 mRNA relative to the LPS group. In addition, the LSB group had a lower proportion of cells in the G0–G1 phase and a higher proportion of cells in the S phase than the LPS group. The mRNA expression of ACAT1 and BDH1 genes related to volatile fatty acid (VFA) metabolism were upregulated in the LSB group compared to those in LPS-induced BRECs. In addition, pretreatment with SB promoted the gene expression of GPR41 in the LPS-induced BRECs. Interestingly, SB pretreatment protected BRECs but not GPR41KD BRECs. Our results suggest that SB pretreatment protects against the changes in BRECs LPS-induced inflammatory response by activating GPR41.

The objective of this study was to determine the effect of replacing isonitrogenous and isoenergetic basis alfalfa hay (AH) with stevia (Stevia rebaudiana) hay in dairy cow diets on nutrient digestion, milk performance, rumen fermentation, and nitrogen (N) utilization. In this study, 24 healthy Holstein lactating dairy cattle with a similar milk yield of 33.70 ± 2.75 (mean ± SD) kg, days in milk 95.98 ± 23.59 (mean ± SD) days, and body weight 587.75 ± 66.97 (mean ± SD) kg were selected and randomly allocated into three groups. The constituents of the three treatments were (1) 30.0% AH, and 0% stevia hay (SH) for the AH group; (2) 24.0% AH, and 6% SH for the 6% SH group; (3) 18.0% AH, and 12% SH for the 12% SH group. The substitution of AH with SH did not affect dry matter intake (DMI), gross energy (GE), and other nutrients intake but increased the digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF). Compared with the AH diet, the cows fed the 6% SH diet had a higher milk yield and concentration of milk fat. Fecal and urinary nitrogen (N) were lower in cows fed a 6% SH diet than in cows fed the AH diet. Milk N secretion and milk N as a percentage of N intake were higher in cows fed a 6% SH diet than in cows fed AH diets. The concentration of ruminal volatile fatty acids, acetic acid, and ammonia-N were higher in cows fed a 6% SH diet than in cows fed an AH diet. By comparison, the 12% SH group did not affect milk yield, milk composition, N utilization, and rumen fermentation compared with the AH and 6% SH groups. In conclusion, it appears that feeding 6% SH, replacing a portion of AH, may improve lactation performance and N utilization for lactating dairy cows.

The aim of this study was to evaluate the effects of buffalo milk and cow milk on lipid metabolism in obese mice. Milk composition analysis showed fat, protein, and total solid content in buffalo milk was higher than cow milk, while the lactose content of buffalo milk was lower than cow milk. After milk metabolite extraction and LC-MS/MS analysis, differential metabolites were mainly enriched in “linoleic acid metabolism pathways,” “pentose and glucuronate interconversion pathways,” and “metabolism of xenobiotics by cytochrome P450 pathways.” We fed three groups of C57BL/6J mice (n = 6 per group) for 5 weeks: (1) high-fat diet group (HFD group); (2) high-fat diet + buffalo milk group (HBM group); and (3) high-fat diet + cow milk group (HCM group). Our results showed that body weight of mice was significantly decreased in HBM and HCM groups from 1 to 4 weeks compared with the HFD group. The mRNA expression of ACAA2, ACACB, and SLC27A5 genes involved in the lipid metabolism in liver tissue were significantly elevated in HCM group, relatively to HFD and HBM group. In addition, the adipocyte number, size and lipid accumulation in the liver were significantly decreased in HCM group compared with the HFD group by H&E staining and oil red O staining, but was not change in HBM group. The mRNA levels of TNF-α and IL-1β inflammatory genes were significantly increased in HBM group, relatively to HFD and HCM group, which is consistent with results from inflammatory cell infiltration and tissue disruption by colon tissue sections. In conclusion, dietary supplementation of cow milk has beneficial effects on loss of weight and lipid metabolism in obese mice.

Short-chain fatty acids (SCFAs) play a pivotal role in regulating the proliferation and development of bovine rumen epithelial cells (BRECs). G protein-coupled receptor 41 (GPR41) is involved in the signal transduction in BRECs as a receptor for SCFAs. Nevertheless, the impact of GPR41 on the proliferation of BRECs has not been reported. The results of this research showed that the knockdown of GPR41 (GRP41KD) decreased BRECs proliferation compared with the wild-type BRECs (WT) (p < 0.001). The RNA sequencing (RNA-seq) analysis showed that the gene expression profiles differed between WT and GPR41KD BRECs, with the major differential genes enriched in phosphatidylinositol 3-kinase (PIK3) signaling, cell cycle, and amino acid transport pathways (p < 0.05). The transcriptome data were further validated by Western blot and qRT-PCR. It was evident that the GPR41KD BRECs downregulated the level of the PIK3-Protein kinase B (AKT)-mammalian target of the rapamycin (mTOR) signaling pathway core genes, such as PIK3, AKT, eukaryotic translation initiation factor 4E binding protein 1 (4EBP1) and mTOR contrasted with the WT cells (p < 0.01). Furthermore, the GPR41KD BRECs downregulated the level of Cyclin D2 p < 0.001) and Cyclin E2 (p < 0.05) compared with the WT cells. Therefore, it was proposed that GPR41 may affect the proliferation of BRECs by mediating the PIK3-AKT-mTOR signaling pathway.

Tea tree oil (TTO) plays an important role in regulating lipid metabolism and has anti-inflammatory properties. In postpartum dairy cows, dry matter intake (DMI) is dramatically decreased, resulting in lipid metabolism disorder and the systemic pro-inflammatory response. However, the effects of TTO on glucolipid metabolism and immunity in postpartum dairy cows remain uninvestigated. Therefore, this study aimed to evaluate the effects of TTO on production performance, serum biochemical indicators, and immunity in postpartum dairy cows. Our results demonstrate that DMI tended to increase (p = 0.07) in the total mixed ration (TMR) diets supplemented with 0.01% TTO/dry matter (DM) basis relative to that in the control group. The 4% fat-corrected milk (FCM) content in the 0.01% and 0.02% TTO groups showed an increase (p = 0.09) compared with that in the control. Remarkably, the levels of globulin (GLO) and immunoglobulin G (IgG) were elevated (p < 0.05) in the TMR diet supplemented with 0.02% TTO compared to those in the control group. The TTO caused no profound changes in cholesterol (CHO), triglyceride (TG), high-density lipoprotein (HDL), or low-density lipoprotein (LDL). Notably, 0.02% TTO increased (p < 0.05) the serum glucose concentration relative to that in the control group. In conclusion, our results demonstrate that TTO could improve glucolipid metabolism and enhance immunity in postpartum dairy cows. It may be a novel resolution strategy for body condition recovery and the improvement of milk performance.

Buckling failure is a major concern in lightweight lattice core sandwich structures (LCSSs). This study proposes an efficient method for designing LCSSs with superior buckling strength under uniaxial compression. In this approach, the buckling-resistant non-uniform shapes of single struts with different slenderness and inclination are first identified, and then they are directly used to replace uniform struts in LCSSs. This method can save considerable design time compared to conventional methods, which require conducting optimizations on entire LCSSs. Numerical results demonstrate that four designed representative non-uniform LCSSs can gain over 15% improvement in buckling strength compared to their counterpart uniform LCSSs. This improvement is even comparable to the solutions from optimizations on entire LCSSs. Two LCSSs with non-uniform struts are 3D printed, and the test results validate at least 10% improvement in compressive strength. Based on the proposed method, various LCSSs with superior buckling strength could be designed for different loadings. [ABSTRACT FROM AUTHOR]

Tea tree oil (TTO) plays an important role in lipid metabolism, alleviating the inflammatory responses. Fatty liver is associated with lipid accumulation in hepatocytes, leading to inflammation. However, there is very limited information on the effects of TTO on lipid accumulation, and inflammation in bovine hepatocytes. This study aimed to evaluate whether TTO alleviates palmitic acid (PA)-induced lipid accumulation in bovine hepatocytes. Hepatocytes isolated from mid-lactating Holstein cows were pretreated with 100 μM PA for 72 h. Cells were either pretreated with PA alone (PA group) or with PA followed by 0.00625% TTO treatment for 12 h (PT group). Expression of fatty acid oxidant genes increased (P < 0.05) while fatty acid synthesis genes decreased (P < 0.05) in the PT group compared with the PA group. PA treatment resulted in increased (P < 0.05) expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), but these increases were less in the PT group (P < 0.05). Compared to the PA group, expression of phosphorylated (p)-p65 and p-inhibitor κBα (p-IκBα) was suppressed (P < 0.05) by TTO treatment. TTO treatment limited (P < 0.05) the increase in intracellular reactive oxygen species (ROS) and prevented (P < 0.05) a reduction in mitochondrial membrane potential observed in response to PA treatment. Expression of endoplasmic reticulum (ER) stress genes was reduced (P < 0.05) in the PT group compared with the PA group. Our results suggest that TTO treatment attenuates the effects of PA in hepatocytes, leading to fatty acid oxidation, decreased fatty acid synthesis, suppressed inflammatory response, and reduced ER stress. Taken together, the results of this study suggest that TTO treatment may be a promising therapeutic approach to imbalanced lipid homeostasis, inflammation and ER stress in dairy cows shortly before and after calving.

Acetate is a precursor substance for fatty acid synthesis in bovine mammary epithelial cells (BMECs), and the mTOR signaling pathway plays an important role in milk fat synthesis. However, the mechanism of the regulatory effects of acetate on lipogenic genes via the mTOR signaling pathway in BMEC remains unknown. We hypothesized that acetate can enhance the expression of lipogenic genes and triglyceride (TG) production by activating the mTOR signaling pathway in BMECs. Therefore, the aim of this study was to investigate the network of acetate-regulated lipid metabolism by the mTOR signaling pathway in BMECs. These results showed that TG synthesis was elevated (p < 0.01) in BMECs with acetate treatment. The lipid droplets were increased in the acetate-treated groups compared with those in the control group through the Bodipy staining of the lipids. In addition, the fatty acid profile in BMECs treated with acetate was affected, with an elevation in the proportions of C14:0, C16:0, and C18:0. The mRNA levels of the sterol-response-element-binding protein 1 (SREBP1), stearoyl-CoA desaturase 1 (SCD1), and fatty acid synthase (FAS) genes involved in the lipogenesis and transcriptional factors were upregulated (p < 0.05) in BMECs with acetate treatment. Remarkably, the expression of acetyl-CoA carboxylase α (ACCα) and FAS rate-limiting enzymes involved in lipogenesis was upregulated in BMECs with acetate treatment. Moreover, the addition of acetate enhanced the key protein expression of S6K1, which is related to the mTOR signaling pathway. Taken together, our data suggest that TG accumulation and expression of lipogenic genes induced by acetate are associated with the activation of the mTOR signaling pathway, which provides new insights into the understanding of the molecular mechanism in the expression of mTOR-signaling-pathway-regulated lipogenic genes.

The E2F family of transcription factor is divided into activators and repressors that control cell proliferation. Bovine mammary epithelial cells (BMECs) can be immortalized using human papillomavirus 16 E6E7 (HPV16 E6E7) and simian vacuolating virus 40 large T antigen (SV40T). In addition, SV40T does not require E2F1, E2F2, and E2F3 activators to induce proliferation in mouse embryo fibroblasts (MEFs). However, we report that E2F3 activator is required to induce the proliferation of BMECs. Our results showed that, at an early stage, primary BMECs lacking the E2F1 expression have the capacity to proliferate and show E2F2 and E2F3 slight protein levels. At a late stage, primary BMECs deficient for E2F3 completely abolish any proliferative ability and exhibit a severe cell senescence signal, although the E2F2 can be expressed at a late stage of primary BMECs. Compared with the late stage of primary BMECs, the BMECs immortalized by SV40T and E6E7 restored the protein level of E2F3 and enhanced the CDK4, CDK6, cyclin D3, and CDK2 protein level, leading to proliferating robustly. Surprisingly, it was found that p53, p21Cip1, and p27Kip1 were upregulated in SV40T and E6E7-immortalized BMECs, relatively to primary BMECs. Notably, Cdc2 was almost expressed in primary BMECs. However, Cdc2 was elevated in BMECs immortalized by SV40T and E6E7. In conclusion, this study revealed a molecular mechanism where E2F3 controls the BMECs’ proliferation and senescence.