Short communication: Menaquinone-4 (vitamin K2) induces proliferation responses in bovine peripheral blood mononuclear cells

Identification of menaquinone-4 (vitamin K2) target genes in bovine endometrial epithelial cells in vitro

The effect of vitamin K on bovine endometrial epithelial cells has not been thoroughly investigated. The objective of this study was to examine the effect of the biologically active form of vitamin K, menaquinone-4, on gene expression in bovine endometrial epithelial cells. First, we examined the mRNA and protein expression levels of UBIAD1, a menaquinone-4 biosynthetic enzyme. Second, we screened for potential target genes of menaquinone-4 in bovine endometrial epithelial cells using RNA-sequencing. We found 50 differentially expressed genes; 42 were upregulated, and 8 were downregulated. Among them, a dose-dependent response to menaquinone-4 was observed for the top three upregulated (TRIB3, IL6, and TNFAIP3) and downregulated (CDC6, ORC1, and RRM2) genes. It has been suggested that these genes play important roles in reproductive events. In addition, GDF15 and VEGFA, which are important for cellular functions as they are commonly involved in pathways, such as positive regulation of cell communication, cell differentiation, and positive regulation of MAPK cascade, were upregulated in endometrial epithelial cells by menaquinone-4 treatment. To the best of our knowledge, this is the first study showing the expression of UBIAD1 in the bovine uterus. Moreover, the study determined menaquinone-4 target genes in bovine endometrial epithelial cells, which may positively affect pregnancy with alteration of gene expression in cattle uterus.

Effect of vitamin K3 supplementation on immunoglobulin G concentration in colostrum of periparturient Holstein dairy cows

This study was to examine the effects of dietary vitamin K (VK) 3 supplementation on immune-related substances in milk, oxidative stress indices in plasma and VK1, and menaquinone 4 (MK-4) in plasma and milk in periparturient dairy cows. Forty healthy perinatal Holstein-Friesian dairy cows were used in this study. Twenty-one animals were randomly selected and categorized into the VK3 supplemented (50 mg/day/head as VK3) group; the remaining 19 were categorized into the control group. On day 3 after calving, blood and milk were sampled, and their chemical components were determined. The VK3 supplemented group had significantly higher menaquinone 4 levels in plasma and milk on day 3 postpartum than the control group. In addition, there was a significant increase in the immunoglobulin G (IgG) level in milk. VK3 may be absorbed from the gastrointestinal tract and converted to MK-4, the biologically active form of VK, in the mammary gland and other tissues. It was thought that the increase in MK-4 level in plasma and milk induced an increase in the concentration of IgG in milk. VK3 supplementation to periparturient dairy cows may contribute to the production of colostrum with high concentrations of IgG and MK-4.

Effects of dietary vitamin K3 supplementation on vitamin K1 and K2 (menaquinone) dynamics in dairy cows

The effect of dietary vitamin K₃ (VK3) on ruminant animals is not fully investigated. The aim of this study was to examine the effects of dietary VK3 on lactation performance, rumen characteristics, and VK1 and menaquinone (MK, or VK2) dynamics in the rumen, plasma, and milk of dairy cows. Eight Holstein dairy cows in late lactation periods were used in two crossover trials including a control (nontreatment) and a 50 or 200 mg/day (d) VK3 supplementation group. After 14 days, plasma, ruminal fluid, and milk were sampled and their VK1 and MKs contents were measured using fluorescence-high-performance liquid chromatography (HPLC). Milk production was unchanged after feeding 50 mg/day VK3 but marginally decreased after feeding 200 mg/day VK3. The molar ratio of propionate in ruminal fluid was significantly increased on feeding 200 mg/day VK3. Additionally, MK-4 concentrations significantly increased in both plasma and milk after VK3 feeding (50 and 200 mg/day). In ruminal fluid, MK-4 concentrations increased after 200 mg/day VK3 feeding. These results suggest that VK3 may be a good source of MK-4, the biologically active form of VK, in Holstein dairy cows during their late lactation periods. This study provides a basis for understanding the physiological role of VK in dairy cows.

Effect of summer heat stress on gene expression in bovine uterine endometrial tissues

Heat stress negatively affects reproductive functions in cows. Increased temperature disturbs fetal development in utero. However, the effect of heat stress on uterine endometrial tissues has not been fully examined. Using qPCR analysis, we measured the mRNA expression of various molecular markers in uterine endometrial tissue of dairy cows from Hokkaido, Japan, in winter and summer. Markers examined were heat shock proteins (HSPs), antioxidant enzymes (catalase, copper/zinc superoxide dismutase, manganese superoxide dismutase, and glutathione peroxidase 4), inflammatory cytokines, and interferon stimulated genes. Our results showed heat stress, body and milk temperatures were higher during summer than during winter. Expression levels of HSP27, HSP60, and HSP90 mRNA, and of catalase and copper/zinc superoxide dismutase mRNA were lower in summer than in winter. Tumor necrosis factor alpha expression was higher in summer than in winter. In conclusion, summer heat stress may reduce the expression of HSPs, affecting the levels of inflammatory cytokines in bovine uterine endometrial tissue.