Retinoic acid attenuates oxidative injury in bovine mammary epithelial cells induced by hydrogen peroxide

The objective of this study was to explore how retinoic acid (RA) attenuates oxidative injury induced by hydrogen peroxide (H2O2) in bovine mammary epithelial cells (BMEC). Subconfluence BMEC were randomly divided into four groups with six replicates: the control group (incubated in serum-free medium without RA or H2O2 for 30 h), H2O2 group (pre-incubated for 24 h without RA, then for another 6 h with 600 μM H2O2), RA group (incubated with 1 mg/ml RA for 30 h without H2O2), and RA + H2O2 group (RA prevention group, pre-incubated with 1 mg/ml RA for 24 h and then for another 6 h with 600 mM H2O2). The results showed that the H2O2 treatment significantly decreased several measured traits, including the cell viability, glutathione peroxidase (GPX) and thioredoxin reductase (TRXR) activities, selenoprotein P (SELP) content, catalase and superoxide dismutase activities, total antioxidant capacity, and GPX1, TRXR1, and SELP gene expression, as well as GPX1 and TRXR1 protein expression. H2O2 treatment also increased the malondialdehyde and reactive oxygen species contents and induced a marked increase of several measured traits, including the arachidonic acid (ARA) concentration, cytosolic phospholipase A2 and 5-lipoxygenase gene expression and activity, and 15-hydroxy twenty-four arachidonic acid and hydroxy peroxide tetracosenic arachidonic acid contents. RA pre-treatment prevented corresponding increases in parameters related to ARA metabolism and increased the activity of TRXR. Moreover, RA pre-treatment attenuated the phosphorylation levels of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase and effectively decreased the ARA content. These results suggest that RA protected BMEC from oxidative stress by elevating TRXR activity, which inhibited the MAPK signaling pathway and led to a decreased concentration of ARA.

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Gene expression of six major milk proteins in primary bovine mammary epithelial cells isolated from milk during the first twenty weeks of lactation

Czech Journal of Animal Science ◽

10.17221/6347-cjas ◽

2012 ◽

Vol 57 (No. 10) ◽

pp. 469-480 ◽

Cited By ~ 15

Author(s):

T. Sigl ◽

H.H.D. Meyer ◽

S. Wiedemann

Keyword(s):

Gene Expression ◽

Epithelial Cells ◽

Milk Protein ◽

Protein Gene ◽

Mammary Epithelial Cells ◽

Mammary Epithelial ◽

Milk Protein Gene ◽

Bovine Mammary Epithelial Cells ◽

Milk Protein Genes ◽

Milk Protein Gene Expression

The objective of the present study was to refine a previously developed method to isolate primary bovine mammary epithelial cells (pBMEC) from fresh milk. Using this method, it was tested whether the number of pBMEC and the relation of recovered pBMEC to total somatic cell count vary within the individual lactation stages. Furthermore, the expression levels of the milk protein genes during the first twenty weeks of lactation were determined by quantitative PCR method. A total number of 152 morning milk samples were obtained from twenty-four Holstein-Friesian cows during the first 20 weeks of lactation (day 8, 15, 26, 43, 57, 113, and 141 postpartum). Numbers of extracted pBMEC were consistent at all time-points (1.1 ± 0.06 to 1.4 ± 0.03 ×103/ml) and an average value of RNA integrity number (RIN) was 6.3 ± 0.3. Percentage of pBMEC in relation to total milk cells (2.0 ± 0.2 to 6.7 ± 1.0%) correlated with milk yield. Expression patterns of the casein genes alpha (α)S1, (α)S2, beta (β), and kappa (κ) (CSN1S1, CSN1S2, CSN2, CSN3, respectively) and the whey protein genes α-lactalbumin (LALBA) and progestagen-associated endometrial protein (PAEP; known as β-lactoglobulin) were shown to be comparable, i.e. transcripts of all six milk protein genes were found to peak during the first two weeks of lactation and to decline continuously towards mid lactation. However, mRNA levels were different among genes with CSN3 showing the highest and LALBA the lowest abundance. We hypothesized that milk protein gene expression has a pivotal effect on milk protein composition with no influence on milk protein concentration. This paper is the first to describe milk protein gene expression during lactation in pBMEC collected in milk. Future studies will be needed to understand molecular mechanisms in pBMEC including regulation of expression and translation throughout lactation.

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Comparison of Selenium Source in Preventing Oxidative Stress in Bovine Mammary Epithelial Cells

Animals ◽

10.3390/ani10050842 ◽

2020 ◽

Vol 10 (5) ◽

pp. 842 ◽

Cited By ~ 1

Author(s):

Lingling Sun ◽

Fang Wang ◽

Zhaohai Wu ◽

Lu Ma ◽

Craig Baumrucker ◽

...

Keyword(s):

Oxidative Stress ◽

Epithelial Cells ◽

Mammary Epithelial Cells ◽

Cell Damage ◽

Antioxidant Response ◽

Mammary Epithelial ◽

Mrna Abundance ◽

Bovine Mammary Epithelial Cells ◽

Pre Treatment ◽

Species Production

Oxidative stress can cause cell damage. Hydroxy-selenomethionine (HMSeBA) is an organic Se source with emerging antioxidant advantages. The objective of this study was to compare the effects of HMSeBA, selenomethionine (SeMet) and sodium selenite (SS) on the antioxidant response and the ability to resist oxidative stress in bovine mammary epithelial cells (BMEC). The BMEC were treated with 0 (Control), 20, 50, 100 and 150 nM HMSeBA, 100 nM SeMet and100 nM SS for 48 h. The results showed that HMSeBA and SeMet treatments had higher glutathione peroxidase (p < 0.01) and catalase (p = 0.01) activities and mRNA abundance of GPX3 (p = 0.02), but lower superoxide dismutase activity compared with SS (p = 0.04). The catalase activity (p < 0.05) and mRNA abundance of GPX3 (p = 0.04) changed in a quadratic manner with the increase of HMSeBA levels. To assess the potential protection of different Se sources against oxidative stress on BMEC, 0 or 50 μM H2O2 was added to BMEC culture for 3 h after Se pre-treatment for 48 h. The results showed that HMSeBA and SeMet, which did not differ (p > 0.05), but further decreased malondialdehyde and reactive oxygen species production compared with SS (p < 0.05). In conclusion, HMSeBA showed an enhanced cellular antioxidant status to resist oxidative damage induced by H2O2 when compared with SS, whereas the effects were similar to SeMet.

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