PO.MCB09.02 · 分子与细胞生物学
ACADS依赖的脂肪酸氧化驱动胰腺癌细胞的线粒体重塑
ACADS-dependent fatty acid oxidation drive mitochondrial remodeling in pancreatic cancer cells
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
胰腺导管腺癌（PDAC）是一种高度侵袭性的癌症，预计到2030年将成为癌症相关死亡的第二大原因。虽然PDAC细胞主要依赖糖酵解，但新出现的证据表明线粒体代谢也有助于肿瘤存活。基质成纤维细胞对胰腺癌线粒体的代谢影响，尤其是通过脂肪酸氧化（FAO）的影响，仍知之甚少。在此，我们研究了成纤维细胞暴露是否改变PDAC细胞的线粒体重塑，以及这种重塑是否依赖于线粒体脂酰辅酶A脱氢酶（ACADS）介导的FAO。在单独培养和与3T3-L1成纤维细胞共培养的Panc1细胞中评估了线粒体变化。使用MitoTracker Red染色和共聚焦显微镜可视化线粒体含量。线粒体和代谢蛋白通过Western印迹定量。使用依托莫昔（Etomoxir，5-100 μM，24小时）抑制肉碱棕榈酰转移酶1（CPT1）。与单独培养的成纤维细胞相比，Panc1细胞显示出较低的基线线粒体质量。然而，当直接共培养时，Panc1细胞表现出线粒体含量增加以及ACADS和线粒体编码的细胞色素c氧化酶（MTCO1）表达升高，提示对成纤维细胞相互作用作出的线粒体适应。为检验这种重塑是否需要下游短链FAO，我们抑制了CPT1，即线粒体脂肪酸转入的限速酶。尽管CPT1并不直接调控ACADS，但依托莫昔介导的CPT1抑制显著降低了ACADS水平，与FAO通量减少一致。CPT1阻断还触发了代谢应激，表现为磷酸化AMP激活蛋白激酶α（p-AMPKα）增加，并导致动力相关蛋白1（DRP1）呈剂量依赖性增加，提示线粒体分裂增强和功能障碍。总之，我们的初步数据提示PDAC细胞依赖完整的脂肪酸氧化来维持线粒体完整性。
查看英文原文 English abstract
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer projected to become the second leading cause of cancer-related deaths by 2030. While PDAC cells rely primarily on glycolysis, emerging evidence indicates that mitochondrial metabolism also contributes to tumor survival. The metabolic impact of stromal fibroblasts on pancreatic cancer mitochondria, particularly through fatty acid oxidation (FAO), remains poorly understood. Here, we investigated whether fibroblast exposure alters mitochondrial remodeling in PDAC cells and if this remodeling depends on mitochondrial fatty Acyl-CoA Dehydrogenase (ACADS) mediated FAO. Mitochondrial changes were assessed in Panc1 cells cultured alone and co-cultured with 3T3-L1 fibroblasts. MitoTracker Red staining and confocal microscopy were used to visualize mitochondrial content. Mitochondrial and metabolic proteins were quantified with Western blotting. Carnitine Palmitoyltransferase 1 (CPT1) was inhibited using Etomoxir (5-100 μM, 24 hrs). Compared with fibroblasts grown separately, Panc1 cells showed lower baseline mitochondrial mass. However, when direct co-cultured, Panc1 cells exhibited increased mitochondrial content and elevated expression of ACADS and Mitochondrially Encoded Cytochrome c Oxidase (MTCO1), suggesting mitochondrial adaptation in response to fibroblast interaction. To test whether this remodeling required downstream short-chain FAO, we inhibited CPT1, the rate-limiting enzyme for mitochondrial fatty-acid import. Although CPT1 does not directly regulate ACADS, Etomoxir-mediated CPT1 inhibition significantly decreased ACADS levels, consistent with reduced FAO flux. CPT1 blockade also triggered metabolic stress, evidenced by increased phosphorylated AMP-activated protein kinase alpha (p-AMPKalpha), and resulted in a dose-dependent increase in Dynamin-Related Protein 1 (DRP1), indicating enhanced mitochondrial fission and dysfunction. Collectively, our preliminary data suggests that PDAC cells depend on intact fatty-acid oxidation to maintain mitochondrial integrity.
利益披露 Disclosure
M. Brown-Blackshear, None..
D. Asamoah, None..
N. Harris, None..
M. Lemecha, None.