Institute of Nutritional Physiology, Leibniz Institute for Farm Animal Biology, Wilhelm-Stahl-Allee, Dummerstorf, Germany.
Institute of Muscle Biology and Growth, Leibniz Institute for Farm Animal Biology, Wilhelm-Stahl-Allee, Dummerstorf, Germany.
PLoS One. 2019 Oct 29;14(10):e0224484. doi: 10.1371/journal.pone.0224484. eCollection 2019.
Dysregulated skeletal muscle metabolism (DSMM) is associated with increased inter- and intramuscular fat deposition in low birth weight (L) individuals. The mechanisms behind DSMM in L individuals are not completely understood but decreased muscle mass and shifts in lipid and carbohydrate utilisation may contribute. Previously, we observed lower fat oxidation in a porcine model of low birth weight. To elucidate the biological activities underpinning this difference microfluidic arrays were used to assess mRNA associated with lipid metabolism in longissimus dorsi (LD) and semitendinosus (ST) skeletal muscle samples from thirty-six female L and normal birth weight (N) pigs. Plasma samples were collected from a sub-population to measure metabolite concentrations. Following overnight fasting, skeletal muscle and plasma samples were collected and the association with birth weight, diet and age was assessed. Reduced dietary fat was associated with decreased LD intermuscular fat deposition and beta-oxidation associated mRNA, in both birth weight groups. Lipid uptake and intramuscular fat deposition associated mRNA was reduced in only L pigs. Abundance of ST mRNA associated with lipolysis, lipid synthesis and transport increased in both birth weight groups. Lipid uptake associated mRNA reduced in only L pigs. These changes were associated with decreased plasma L glucose and N triacylglycerol. Post-dietary fat reduction, LD mRNA associated with lipid synthesis and inter- and intramuscular fat deposition increased in L, whilst beta-oxidation associated mRNA remains elevated for longer in N. In the ST, mRNA associated with lipolysis and intramuscular fat deposition increased in both birth weight groups, however this increase was more significant in L pigs and associated with reduced beta-oxidation. Analysis of muscle lipid metabolism associated mRNA revealed that profile shifts are a consequence of birth weight. Whilst, many of the adaptions to diet and age appear to be similar in birth weight groups, the magnitude of response and individual changes underpin the previously observed lower fat oxidation in L pigs.
骨骼肌代谢失调（DSMM）与低出生体重（LBW）个体中肌内和肌间脂肪沉积增加有关。LBW 个体中 DSMM 的机制尚不完全清楚，但肌肉质量减少和脂质及碳水化合物利用的转变可能与之相关。此前，我们观察到在 LBW 的猪模型中脂肪氧化减少。为了阐明这一差异的生物学基础，我们使用微流控阵列评估了来自 36 头 LBW 和正常出生体重（NBW）母猪的背最长肌（LD）和半腱肌（ST）骨骼肌样本中与脂质代谢相关的 mRNA。从亚群中采集血浆样本以测量代谢物浓度。在禁食过夜后，采集骨骼肌和血浆样本，并评估与出生体重、饮食和年龄的关系。在两个出生体重组中，减少膳食脂肪与 LD 肌间脂肪沉积和与β氧化相关的 mRNA 减少有关。仅在 LBW 猪中，脂质摄取和肌内脂肪沉积相关 mRNA 减少。仅在 LBW 猪中，与脂肪分解、脂质合成和转运相关的 ST mRNA 丰度增加。仅在 LBW 猪中，脂质摄取相关 mRNA 减少。这些变化与血浆中 L 葡萄糖和 N 三酰甘油减少有关。在减少膳食脂肪后，LBW 中与脂质合成和肌间及肌内脂肪沉积相关的 LD mRNA 增加，而与β氧化相关的 mRNA 在 NBW 中仍维持较长时间的高水平。在 ST 中，与脂肪分解和肌内脂肪沉积相关的 mRNA 在两个出生体重组中均增加，但在 LBW 猪中增加更为显著，并且与β氧化减少有关。对肌肉脂质代谢相关 mRNA 的分析表明，谱的变化是出生体重的结果。虽然，饮食和年龄的许多适应在出生体重组中似乎是相似的，但反应的幅度和个体变化是 LBW 猪中先前观察到的较低脂肪氧化的基础。
