A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
Physiol Rep. 2020 Jul;8(13):e14474. doi: 10.14814/phy2.14474.
Dietary fats are essential for cardiac function. The metabolites of fats known as fatty acids provide most of the energy for cardiac tissue, serve as building blocks for membranes and regulate important signaling cascades. Despite their importance, excess fat intake can cause cardiac dysfunction. The detrimental effects of high-fat diet (HFD) on cardiac health are widely investigated in long-term studies but the short-term effects of fats have not been thoroughly studied. To elucidate the near-term effects of a HFD on the growth and maturation of late adolescent heart we subjected 11-week-old mice to an 8-week long HFD (42% of calories from fat, 42% from carbohydrate, n = 8) or chow diet (12% of calories from fat, 66% from carbohydrate, n = 7) and assessed their effects on the heart in vivo and in vitro. Our results showed that excessive fat feeding interferes with normal maturation of the heart indicated by the lack of increase in dimensions, volume, and stroke volume of the left ventricles of mice on high fat diet that were evident in mice on chow diet. In addition, differences in regional strain during the contraction cycle between mice on HFD and chow diet were seen. These changes were associated with reduced activity of the growth promoting PI3K-Akt1 signaling cascade and moderate changes in glucose metabolism without changes in calcium signaling. This study suggests that even a short period of HFD during late adolescence hinders cardiac maturation and causes physiological changes that may have an impact on the cardiac health in adulthood.
膳食脂肪对心脏功能至关重要。脂肪的代谢产物——脂肪酸，为心肌提供了大部分能量，是构成细胞膜的物质基础，并调节着重要的信号级联反应。尽管脂肪非常重要，但过量的脂肪摄入会导致心脏功能障碍。长期研究广泛探讨了高脂肪饮食（HFD）对心脏健康的有害影响，但脂肪的短期影响尚未得到充分研究。为了阐明 HFD 对青春期后期心脏生长和成熟的近期影响，我们将 11 周龄的小鼠置于 8 周的 HFD（脂肪提供 42%的热量，碳水化合物提供 42%的热量，n=8）或标准饮食（脂肪提供 12%的热量，碳水化合物提供 66%的热量，n=7）中，并评估它们对体内和体外心脏的影响。我们的结果表明，过量的脂肪喂养会干扰心脏的正常成熟，表现在高脂肪饮食组小鼠的左心室尺寸、体积和每搏输出量没有增加，而在标准饮食组小鼠中则有增加。此外，还观察到高脂肪饮食组和标准饮食组小鼠在收缩周期中局部应变的差异。这些变化与促进生长的 PI3K-Akt1 信号级联的活性降低以及葡萄糖代谢的适度变化有关，而钙信号没有变化。这项研究表明，即使是青春期后期的短暂 HFD 也会阻碍心脏成熟，并导致可能对成年人心血管健康产生影响的生理变化。
