Université de Nantes, CHU Nantes, CNRS, INSERM, l'institut du thorax, Nantes, France.
Université catholique de Louvain, Institut de Recherche Expérimentale et Clinique, Pole of Cardiovascular Research, Brussels, Belgium.
Acta Physiol (Oxf). 2021 Mar;231(3):e13566. doi: 10.1111/apha.13566. Epub 2020 Oct 16.
Metabolic sources switch from carbohydrates in utero, to fatty acids after birth and then a mix once adults. O-GlcNAcylation (O-GlcNAc) is a post-translational modification considered as a nutrient sensor. The purpose of this work was to assess changes in protein O-GlcNAc levels, regulatory enzymes and metabolites during the first periods of life and decipher the impact of O-GlcNAcylation on cardiac proteins.
Heart, brain and liver were harvested from rats before and after birth (D-1 and D0), in suckling animals (D12), after weaning with a standard (D28) or a low-carbohydrate diet (D28F), and adults (D84). O-GlcNAc levels and regulatory enzymes were evaluated by western blots. Mass spectrometry (MS) approaches were performed to quantify levels of metabolites regulating O-GlcNAc and identify putative cardiac O-GlcNAcylated proteins.
Protein O-GlcNAc levels decrease drastically and progressively from D-1 to D84 (13-fold, P < .05) in the heart, whereas the changes were opposite in liver and brain. O-GlcNAc levels were unaffected by weaning diet in any tissues. Changes in expression of enzymes and levels of metabolites regulating O-GlcNAc were tissue-dependent. MS analyses identified changes in putative cardiac O-GlcNAcylated proteins, namely those involved in the stress response and energy metabolism, such as ACAT1, which is only O-GlcNAcylated at D0.
Our results demonstrate that protein O-GlcNAc levels are not linked to dietary intake and regulated in a time and tissue-specific manner during postnatal development. We have identified by untargeted MS putative proteins with a particular O-GlcNAc signature across the development process suggesting specific role of these proteins.
代谢来源在子宫内从碳水化合物转变，出生后从脂肪酸转变，然后在成年后混合。O-连接的 N-乙酰氨基葡萄糖（O-GlcNAc）是一种被认为是营养传感器的翻译后修饰。本工作的目的是评估生命早期阶段蛋白质 O-GlcNAc 水平、调节酶和代谢物的变化，并解析 O-GlcNAc 化对心脏蛋白的影响。
在出生前（D-1 和 D0）和出生后（D12）、哺乳期（D12）、断奶后（D28 或 D28F）和成年期（D84）从大鼠的心脏、大脑和肝脏中采集样本。通过 Western blot 评估 O-GlcNAc 水平和调节酶。通过质谱（MS）方法定量调节 O-GlcNAc 的代谢物水平，并鉴定潜在的心脏 O-GlcNAc 化蛋白。
心脏中的蛋白质 O-GlcNAc 水平从 D-1 到 D84 急剧且逐渐下降（13 倍，P <.05），而在肝脏和大脑中则相反。断奶饮食对任何组织中的 O-GlcNAc 水平均无影响。调节 O-GlcNAc 的酶和代谢物水平的变化与组织有关。MS 分析鉴定出潜在的心脏 O-GlcNAc 化蛋白的变化，例如那些参与应激反应和能量代谢的蛋白，例如仅在 D0 时才被 O-GlcNAc 化的 ACAT1。
我们的结果表明，蛋白质 O-GlcNAc 水平与饮食摄入无关，并在出生后发育过程中以时间和组织特异性的方式进行调节。我们通过非靶向 MS 鉴定出具有特定 O-GlcNAc 特征的潜在蛋白，这些蛋白在整个发育过程中都存在，这表明这些蛋白具有特定的作用。
