Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal.
ICVS/3B's-PT Government Associate Laboratory, 4710-057 Braga/Guimarães, Portugal.
Int J Mol Sci. 2024 May 6;25(9):5054. doi: 10.3390/ijms25095054.
Lung branching morphogenesis relies on intricate epithelial-mesenchymal interactions and signaling networks. Still, the interplay between signaling and energy metabolism in shaping embryonic lung development remains unexplored. Retinoic acid (RA) signaling influences lung proximal-distal patterning and branching morphogenesis, but its role as a metabolic modulator is unknown. Hence, this study investigates how RA signaling affects the metabolic profile of lung branching. We performed ex vivo lung explant culture of embryonic chicken lungs treated with DMSO, 1 µM RA, or 10 µM BMS493. Extracellular metabolite consumption/production was evaluated by using H-NMR spectroscopy. Mitochondrial respiration and biogenesis were also analyzed. Proliferation was assessed using an EdU-based assay. The expression of crucial metabolic/signaling components was examined through Western blot, qPCR, and in situ hybridization. RA signaling stimulation redirects glucose towards pyruvate and succinate production rather than to alanine or lactate. Inhibition of RA signaling reduces lung branching, resulting in a cystic-like phenotype while promoting mitochondrial function. Here, RA signaling emerges as a regulator of tissue proliferation and lactate dehydrogenase expression. Furthermore, RA governs fatty acid metabolism through an AMPK-dependent mechanism. These findings underscore RA's pivotal role in shaping lung metabolism during branching morphogenesis, contributing to our understanding of lung development and cystic-related lung disorders.
肺分支形态发生依赖于复杂的上皮-间充质相互作用和信号网络。然而，信号转导和能量代谢在塑造胚胎肺发育中的相互作用仍未被探索。视黄酸（RA）信号影响肺近端-远端模式形成和分支形态发生，但它作为代谢调节剂的作用尚不清楚。因此，本研究调查了 RA 信号如何影响肺分支的代谢特征。我们对用 DMSO、1 µM RA 或 10 µM BMS493 处理的鸡胚肺进行了离体肺外植体培养。通过 1 H-NMR 光谱分析评估细胞外代谢物的消耗/产生。还分析了线粒体呼吸和生物发生。通过基于 EdU 的测定评估增殖。通过 Western blot、qPCR 和原位杂交检查关键代谢/信号成分的表达。RA 信号刺激将葡萄糖重新导向丙酮酸和琥珀酸的产生，而不是丙氨酸或乳酸。抑制 RA 信号会减少肺分支，导致囊性样表型，同时促进线粒体功能。在这里，RA 信号作为组织增殖和乳酸脱氢酶表达的调节剂出现。此外，RA 通过 AMPK 依赖性机制调节脂肪酸代谢。这些发现强调了 RA 在分支形态发生过程中塑造肺代谢中的关键作用，有助于我们理解肺发育和囊性相关肺疾病。
