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Nissim Silanikove, Fira Shapiro, Adi Rauch & Gabriel Leitner

Distribution of Xanthine Dehydrogenase and Xanthine Oxidase in milk fractions : Evidence for post-transcriptional regulation of Xanthine Oxidase in the frame of the mammary innate immune defense system. Nissim Silanikove, Fira Shapiro, Adi Rauch & Gabriel Leitner. Nitrite NADH. NitrateNAD.

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Nissim Silanikove, Fira Shapiro, Adi Rauch & Gabriel Leitner

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  1. Distribution of Xanthine Dehydrogenase and Xanthine Oxidase in milk fractions : Evidence for post-transcriptional regulation of Xanthine Oxidase in the frame of the mammary innate immune defense system Nissim Silanikove, Fira Shapiro, Adi Rauch & Gabriel Leitner

  2. Nitrite NADH NitrateNAD Or2H2O2 SOD

  3. Reaction of Lactoperoxidase with Hydrogen peroxide and Nitrite Nitric Oxide is a Free Radical 1. LPO + H2O2 LPO compound 1 2. LPO compound I + NO2- LPO compound II + ●NO2 3. LPO compound II + NO2- LPO + ●NO2 N=O

  4. Scenario of NO cycling and metabolism in mammary secretion (Free radicals Biol Med, 2005)

  5. Question Number 1 • In the mammary gland, XOR has an essential, non-enzymatic, structural role in fat secretion (Vorbach et al. Genes Dev 2002, 16:3223) • It is well established that XOR associated with fat secretion is located within the inner side of MFGM ) e.g. J. Physiol 2002, 545:567) Do we have sufficient XO to support its role in innate immunity? (Free radicals biol Med 2005, 38: 1139 )

  6. Xanthine + hypoxanthine and uric acid concentration in oxytocin-induced and mature milk

  7. QuestionNumber2 As mature fresh milk do not contains measurable amount of xanthine, but contains uric acid in the range of 30 40 -micro-molar, it is important to know whether it derived from milk xanthine or secreted as uric acid? Fresh milk (i.e., milk secreted into the alveoli within 5 to 10 min before sampling) was obtained at the end of noon-milking following injection of oxytocine.

  8. Distribution of xanthine oxidase, alkaline phosphatase and acid phosphatase in milk fractions Xanthine oxidase Alkaline phosphataseAcid phosphatase % of total % of total % of total Whoe milk100 100 100 Fat* (MFGM) 33 45 48 WMP 21 39 34 Phos.lipids54 84 82 Casein 3 - - Truly soluble43 16 18

  9. Distribution of enzymes inside and outside of WMP membranes XO (U/ml) XD (U/ ml) XD/XO Total XD/XO Inside AlP (U/ml) AcP (U/ml) Intact1.11 - - - 114 16.2 Total1.55 1.10 0.71 2.5 118 15.1

  10. Distribution of enzymes in MFGM with and without plasmin deactivation With plasmin deactivation Without plasmin deactivation XO (U/g) 2.4 ± 0.4 3.7 ± 0.6 XD (U/g)1.7 ± 0.5 - XD/XO Total0.7 ± 0.08 - XD/XO inside4.25 ± 0.5 - AlP (U/g)135 ± 10 142 ± 15 AcP (U/g)39 ± 7 42 ± 9

  11. Distribution of protein in milk fractions Total protein Casein Protein in WMP Protein in MFGM g/l % of total g/l % of total g/Kg % of total g/Kg % of total 29.2 100 22.7 78 44.3 0.094 40.3 0.095

  12. Lipid composition (as % of dry matter) in whey membrane particles (WMP) and milk fat globule membranes (MFGM) WMP MFGM Average SD Average SD Total lipid25.62.7 29.7 3.1 Lipid P0.530 0.09 0.621 0.11 Phos.lipids13.25 2.25 15.53 2.75

  13. Question Number 3 Does XO-derived oxidative stress play a rolein sub-clinical mastitis;i.e., under conditions that do not elicit an apparent classical inflammatory symptoms

  14. Cork 2005 The model: Each cow tested had at least one uninfected quarter (NBF) and one of the other quarters infected with one of the following bacteria: - +

  15. BOLFA 2006 Uric acid and nitrate in sub-clinically infected glands

  16. Cork 2005 Clotting time and curd firmness

  17. Question Number 4 Does XO-derived oxidative stress play a rolein clinical mastitis;i.e., under conditions that elicit an apparent classical inflammatory symptoms

  18. The model: Each cow tested was infused in one quarter once with Casein hydrolyzate, lipopolysaccharide, or saline, and samples from each gland were sampled for two days post-treatment BOLFA 2006

  19. Effect of infusion of CNH and LPS into the mammary gland on the immune cell population Treatment SCC (×1000) PMN (%) CD4+ (% CD8+ (%) CD14+ (%) Control 116±20a 29±3.3a 3.1±0.9a 5.7±1.6a 5.5±1.8a CNH 3146±324b 57±7b 3.3±1.1a 10.5±2.0b 12.6±2.2b LPS 4960±793c 90±9.1c 1.8±2.2b 4.4±4.0a 6.6±4.4a

  20. Caseinolysis (proteose peptone formation) in CNH and LPS treated glands

  21. Uric acid in CNH / LPS treated glands

  22. Nitrate in CNH and LPS treated glands

  23. Major conclusions • Our data suggest that XO is post-transcriptional regulated through allocation of substrate (xanthine) availability. • Together with lactic peroxidase they involve in the oxidative (mostly nitrosative) stress in certain type of sub-clinical mastitis. • This system is the main driving force of oxidative/nitosative stress in E.Coli/LPS driven mastitis.

  24. The Jekyll and Hyde sides of uric acid • Uric acid is a major anti-oxidant in blood plasma and milk • However, uric acid is also a danger signal that alerts the immune system to dying cells (Nature 425: 516, 2003). • In hyperuricemia, crystals of uric acid canprecipitate in joins, where they cause gout and/or in other tissues causing inflammation. • Does XO-depended gouty inflammation involve in the pathogenesis induced by E. coli/LPS in the mammary gland ?

  25. BOLFA 2006 Thank you: I hope that this lecture will contribute to our ability to raise healthier cows and produce better dairy products

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