奶牛泌乳早期肝线粒体功能受损：与蛋白质赖氨酸乙酰化的关系

Impaired hepatic mitochondrial function during early lactation in dairy cows: Association with protein lysine acetylation

Keywords：Early lactation; liver mitochondria; oxygen consumption rate; oxidative stress

关键词：泌乳早期；肝线粒体;耗氧率；氧化应激

哺乳动物：牛类

作者：García-Roche M, Casal A, Mattiauda DA, Ceriani M, Jasinsky A, Mastrogiovanni M, Trostchansky A, Carriquiry M, Cassina A, Quijano C

出版期刊：《PLoS One》 2019/3/14

Abstract：

Early lactation is an energy-demanding period for dairy cows which may lead to negative energy balance, threatening animal health and consequently productivity. Herein we studied hepatic mitochondrial function in Holstein-Friesian multiparous dairy cows during lactation, under two different feeding strategies. During the first 180 days postpartum the cows were fed a total mixed ration (70% forage: 30% concentrate) ad libitum (non-grazing group, G0) or grazed Festuca arundinacea or Mendicago sativa plus supplementation (grazing group, G1). From 180 to 250 days postpartum, all cows grazed Festuca arundinacea and were supplemented with total mixed ration. Mitochondrial function was assessed measuring oxygen consumption rate in liver biopsies and revealed that maximum respiratory rate decreased significantly in grazing cows during early lactation, yet was unchanged in non-grazing cows during the lactation curve. While no differences could be found in mitochondrial content or oxidative stress markers, a significant increase in protein lysine acetylation was found in grazing cows during early lactation but not in cows from the non-grazing group. Mitochondrial acetylation positively correlated with liver triglycerides and β-hydroxybutyrate plasma levels, well-known markers of negative energy balance, while a negative correlation was found with the maximum respiratory rate and sirtuin 3 levels. To our knowledge this is the first report of mitochondrial function in liver biopsies of dairy cows during lactation. On the whole our results indicate that mitochondrial function is impaired during early lactation in grazing cows and that acetylation may account for changes in mitochondrial function in this period. Additionally, our results suggest that feeding total mixed ration during early lactation may be an efficient protective strategy.

文章摘要：

泌乳早期是奶牛能量需求的时期，这可能导致能量负平衡，威胁动物健康，进而威胁生产力。在此，我们研究了荷斯坦-弗里斯兰经产奶牛在两种不同喂养策略下泌乳期间的肝线粒体功能。在产后的前 180 天，奶牛被随意饲喂总混合日粮（70% 的草料：30% 的精料）（非放牧组，G0）或放牧羊茅或门迪卡加补充剂（放牧组，G1）。从产后 180 天到 250 天，所有奶牛都吃过羊肚草并补充全混合日粮。通过测量肝活检中的耗氧率评估线粒体功能，发现在泌乳早期放牧奶牛的最大呼吸频率显着降低，但在泌乳曲线期间非放牧奶牛的最大呼吸频率没有变化。虽然在线粒体含量或氧化应激标志物方面没有发现差异，但在泌乳早期放牧奶牛中发现蛋白质赖氨酸乙酰化显着增加，但在非放牧组的奶牛中没有。线粒体乙酰化与肝脏甘油三酯和β-羟基丁酸血浆水平（众所周知的负能量平衡标志物）呈正相关，而与最大呼吸频率和sirtuin 3水平呈负相关。据我们所知，这是关于哺乳期奶牛肝活检中线粒体功能的第一份报告。总的来说，我们的研究结果表明，在放牧奶牛的泌乳早期，线粒体功能受损，乙酰化可能是这一时期线粒体功能变化的原因。此外，我们的研究结果表明，在泌乳早期喂养全混合日粮可能是一种有效的保护策略。

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