Vaccination of dairy cows with recombinant Streptococcus uberis adhesion molecule induces antibodies that reduce adherence to and internalization of S. uberis into bovine mammary epithelial cells

2011 ◽  
Vol 141 (3-4) ◽  
pp. 201-208 ◽  
Author(s):  
M.E. Prado ◽  
R.A. Almeida ◽  
C. Ozen ◽  
D.A. Luther ◽  
M.J. Lewis ◽  
...  
2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Zhuo-Ma Luoreng ◽  
Da-Wei Wei ◽  
Xing-Ping Wang

AbstractMastitis is a complex inflammatory disease caused by pathogenic infection of mammary tissue in dairy cows. The molecular mechanism behind its occurrence, development, and regulation consists of a multi-gene network including microRNA (miRNA). Until now, there is no report on the role of miR-125b in regulating mastitis in dairy cows. This study found that miR-125b expression is significantly decreased in lipopolysaccharide (LPS)-induced MAC-T bovine mammary epithelial cells. Also, its expression is negatively correlated with the expression of NF-κB inhibitor interacting Ras-like 2 (NKIRAS2) gene. MiR-125b target genes were identified using a double luciferase reporter gene assay, which showed that miR-125b can bind to the 3′ untranslated region (3′ UTR) of the NKIRAS2, but not the 3′UTR of the TNF-α induced protein 3 (TNFAIP3). In addition, miR-125b overexpression and silencing were used to investigate the role of miR-125b on inflammation in LPS-induced MAC-T. The results demonstrate that a reduction in miR-125b expression in LPS-induced MAC-T cells increases NKIRAS2 expression, which then reduces NF-κB activity, leading to low expression of the inflammatory factors IL-6 and TNF-α. Ultimately, this reduces the inflammatory response in MAC-T cells. These results indicate that miR-125b is a pro-inflammatory regulator and that its silencing can alleviate bovine mastitis. These findings lay a foundation for elucidating the molecular regulation mechanism of cow mastitis.


2011 ◽  
Vol 147 (3-4) ◽  
pp. 426-434 ◽  
Author(s):  
Xueyan Chen ◽  
Oudessa Kerro Dego ◽  
Raul A. Almeida ◽  
Troy E. Fuller ◽  
Douglas A. Luther ◽  
...  

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Raul A. Almeida ◽  
John R. Dunlap ◽  
Stephen P. Oliver

We showed that internalization ofStreptococcus uberisinto bovine mammary epithelial cells occurred through receptor- (RME) and caveolae-mediated endocytosis (CME). We reported also that treatment ofS. uberiswith host proteins including lactoferrin (LF) enhanced its internalization into host cells. Since the underlying mechanism(s) involved in such enhancement was unknown we investigated if preincubation ofS. uberiswith host proteins drives internalization of this pathogen into host cells through CME. Thus, experiments involving coculture of collagen-, fibronectin-, and LF-pretreatedS. uberiswith bovine mammary epithelial cells treated with RME and CME inhibitors were conducted. Results showed that internalization of host proteins-pretreatedS. uberisinto mammary epithelial cells treated with RME inhibitors was higher than that of untreated controls. These results suggest that pretreatment with selected host proteins commitsS. uberisto CME, thus avoiding intracellular bactericidal mechanisms and allowing its persistence into bovine mammary epithelial cells.


2018 ◽  
Vol 85 (1) ◽  
pp. 53-56 ◽  
Author(s):  
Raúl A. Almeida ◽  
Oudessa Kerro-Dego ◽  
Agustín G. Rius

Heat stress (HS) negatively affects milk production and has been associated with decreased immune function, and increased rate of intramammary infections (IMI). Research has shown that HS affects gene expression, cell cycle, and cell metabolism in bovine mammary epithelial cells (BMEC). Since BMEC are an initial target of mastitis pathogens, we studied adherence to and internalisation of S. uberis into HS-BMEC, as well as the effect that this interaction has on host cells by measuring HS-BMEC viability and membrane integrity. Results reported in this Research Communication showed that HS reduced cell viability and induced membrane damage. However, these pathological changes, as well as the rate of adherence and internalisation of S. uberis into BMEC, were augmented when S. uberis was cocultured with HS-BMEC. These results may help to understand the pathogenesis of S. uberis IMI as well as the increased susceptibility of mammary glands to IMI in cows subjected to HS.


2020 ◽  
Vol 60 (16) ◽  
pp. 1877
Author(s):  
Yujia Sun ◽  
Hailei Xia ◽  
Xubin Lu ◽  
Chong Xu ◽  
Mingxun Li ◽  
...  

Context The regulation of milk lipids is important for the evaluation of dairy cows’ performance. Lipids are produced and secreted by mammary gland under the regulation of steroid hormones, growth factors and microRNAs (miRNAs). MicroRNAs have been verified to be involved in numerous biological processes. Previous studies have shown that miR-141 is expressed at higher levels in dairy cows at peak lactation than in those at early lactation. However, the roles of miR-141 in bovine mammary epithelial cells (BMECs) and the mechanisms how it affects lipid metabolism are as yet unknown. Aims The aims of this study were to clarify (i) the molecular mechanisms of miR-141 in milk lipid metabolism, and (ii) how miR-141 affects milk lipid metabolism in BMECs. Methods Triglycerides were observed in BMECs using triglyceride analysis after overexpression or inhibition of miR-141; selected potential candidate genes that are targeted by miR-141 using TargetScan. The regulatory relationship among miR-141, SIRT1 gene and lipid metabolism-related genes (SREBF1, FASN and PPARγ) by using the dual luciferase assay, quantitative real-time PCR and western blotting. Key results Through overexpression or inhibition of miR-141 expression, we found that miR-141 promoted lipid metabolism in BMECs and an increase in triglycerides was observed in these cells. Further, miR-141 targets the 3′UTR of SIRT1 mRNA, and negative regulates the expression of SIRT1 gene in BMECs. Also, the expression levels of SREBF1, FASN and PPARγ, which are related to milk lipid metabolism, were also altered after overexpression miR-141. Conclusions Our results have revealed that miR-141 could promote milk lipid metabolism in BMECs by means of negative regulates SIRT1 gene and positive effects lipid metabolism-related genes (SREBF1, FASN and PPARγ) in BMECs. Implications Our research indicates that miR-141 could be considered a marker in cattle breeding to obtain high quality dairy products. It would be useful to study the function of miRNAs in milk lipid metabolism and synthesis. In the long term these findings might be helpful in developing practical means to improve the quality of ruminant milk.


Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3238
Author(s):  
Xinlu Liu ◽  
Jinglin Shen ◽  
Jinxin Zong ◽  
Jiayi Liu ◽  
Yongcheng Jin

β-sitosterol, a phytosterol with multiple biological activities, has been used in the pharmaceutical industry. However, there are only a few reports on the use of β-sitosterol in improving milk synthesis in dairy cows. This study aimed to investigate the effects of β-sitosterol on milk fat and protein syntheses in bovine mammary epithelial cells (MAC-T) and its regulatory mechanism. MAC-T cells were treated with different concentrations (0.01, 0.1, 1, 5, 10, 20, 30, or 40 μM) of β-sitosterol, and the expression levels of milk protein and fat synthesis-related genes and proteins were analyzed. β-sitosterol at 0.1, 1, and 10 μM concentrations promoted the mRNA and protein expression of β-casein. β-sitosterol (0.1, 1, 10 μM) increased the mRNA and protein expression levels of signal transducer activator of transcription 5 (STAT5), mammalian target of rapamycin (mTOR), and ribosomal protein S6 kinase beta-1 (S6K1) of the JAK2/STAT5 and mTOR signaling pathways. It also stimulated the milk fat synthesis-related factors, including sterol regulatory element-binding protein 1 (SREBP1), peroxisome proliferator-activated receptor-gamma (PPARγ), acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL), and stearyl CoA desaturase (SCD). β-sitosterol (0.1, 1, 10 μM) also significantly increased the expression of growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and hypoxia-inducible factor-1α (HIF-1α)-related genes. Notably, the compound inhibited the expression of the negative regulator, the suppressor of cytokine signaling 2 (SOCS2) at the two lower concentrations (0.1, 1 μM), but significantly promoted the expression at the highest concentration (30 μM). These results highlight the role of β-sitosterol at concentrations ranging from 0.1 to 10 μM in improving milk protein and fat syntheses, regulating milk quality. Therefore, β-sitosterol can be used as a potential feed additive to improve milk quality in dairy cows.


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