Department of Pharmacology and Toxicology, The Joint Graduate Program in Toxicology, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey.
Rutgers Institute for Translational Medicine and Science, Rutgers, The State University of New Jersey, New Brunswick, New Jersey.
Am J Physiol Lung Cell Mol Physiol. 2022 Sep 1;323(3):L297-L307. doi: 10.1152/ajplung.00132.2022. Epub 2022 Jul 5.
Obesity can aggravate asthma by enhancing airway hyperresponsiveness (AHR) and attenuating response to treatment. However, the precise mechanisms linking obesity and asthma remain unknown. Human airway smooth muscle (HASM) cells exhibit amplified excitation-contraction (EC) coupling and force generation in obesity. Therefore, we posit that airway smooth muscle (ASM) cells obtained from obese donors manifest a metabolomic phenotype distinct from that of nonobese donor cells and that a differential metabolic phenotype, at least in part, drives enhanced ASM cell EC coupling. HASM cells derived from age-, sex-, and race-matched nonobese [body mass index (BMI) ≤ 24.9 kg·m] and obese (BMI ≥ 29.9 kg·m) lung donors were subjected to unbiased metabolomic screening. The unbiased metabolomic screening identified differentially altered metabolites linked to glycolysis and citric acid cycle in obese donor-derived cells compared with nonobese donor cells. The Seahorse assay measured the bioenergetic profile based on glycolysis, mitochondrial respiration, palmitate oxidation, and glutamine oxidation rates in HASM cells. Glycolytic rate and capacity were elevated in obese donor-derived HASM cells, whereas mitochondrial respiration, palmitate oxidation, and glutamine oxidation rates were comparable between obese and nonobese groups. mRNA and protein expression levels were also elevated in obese donor-derived HASM cells. Furthermore, pharmacological inhibition of PFKFB3 attenuated agonist-induced myosin light chain (MLC) phosphorylation in HASM cells derived from obese and nonobese donors. Our findings identify elevated glycolysis as a signature metabolic phenotype of obesity and inhibition of glycolysis attenuates MLC phosphorylation in HASM cells. These findings identify novel therapeutic targets to mitigate AHR in obesity-associated asthma.
肥胖可通过增强气道高反应性（AHR）和减弱治疗反应而加重哮喘。然而，将肥胖与哮喘联系起来的确切机制尚不清楚。人体气道平滑肌（HASM）细胞在肥胖中表现出增强的兴奋-收缩（EC）偶联和力生成。因此，我们假设来自肥胖供体的气道平滑肌（ASM）细胞表现出与非肥胖供体细胞不同的代谢表型，并且至少部分是不同的代谢表型驱动增强的 ASM 细胞 EC 偶联。从年龄、性别和种族匹配的非肥胖（BMI≤24.9kg·m）和肥胖（BMI≥29.9kg·m）肺供体中获得 HASM 细胞，并进行无偏见的代谢组学筛选。无偏见的代谢组学筛选鉴定出与肥胖供体衍生细胞中的糖酵解和柠檬酸循环相关的差异改变的代谢物。 Seahorse 测定法基于 HASM 细胞中的糖酵解、线粒体呼吸、棕榈酸氧化和谷氨酰胺氧化率来测量生物能量谱。肥胖供体衍生的 HASM 细胞中的糖酵解率和能力升高，而线粒体呼吸、棕榈酸氧化和谷氨酰胺氧化率在肥胖和非肥胖组之间相当。肥胖供体衍生的 HASM 细胞中的 mRNA 和蛋白表达水平也升高。此外，PFKFB3 的药理学抑制减弱了肥胖和非肥胖供体来源的 HASM 细胞中激动剂诱导的肌球蛋白轻链（MLC）磷酸化。我们的发现确定了升高的糖酵解作为肥胖的特征代谢表型，并且抑制糖酵解减弱了 HASM 细胞中的 MLC 磷酸化。这些发现确定了减轻肥胖相关哮喘中 AHR 的新治疗靶标。
