Source data for Dwenger et al., 2022, Nature Communications

Description

Source data from study described in Dwenger et al., Nature Communications, 2022 Apr 19; 13(1):2051.

Steps to reproduce

Project title: Pyridine nucleotide redox potential in coronary smooth muscle couples myocardial blood flow to cardiac metabolism Citation information: Dwenger MM, Raph SM, Reyzer ML, Lisa Manier M, Riggs DW, Wohl ZB, Ohanyan V, Mack G, Pucci T, Moore JB 4th, Hill BG, Chilian WM, Caprioli RM, Bhatnagar A, Nystoriak MA. Pyridine nucleotide redox potential in coronary smooth muscle couples myocardial blood flow to cardiac metabolism. Nat Commun. 2022 Apr 19;13(1):2051. doi: 10.1038/s41467-022-29745-z. PMID: 35440632; PMCID: PMC9018695. The project description: Adequate oxygen delivery to the heart during stress is essential for sustaining cardiac function. Acute increases in myocardial oxygen demand evoke coronary vasodilation and enhance perfusion via functional upregulation of smooth muscle voltage-gated K+ (Kv) channels. Because this response is controlled by Kv1 accessory subunits (i.e., Kvβ), which are NAD(P)(H)-dependent aldo-keto reductases, we tested the hypothesis that oxygen demand modifies arterial [NAD(H)]i, and that resultant cytosolic pyridine nucleotide redox state influences Kv1 activity. High-resolution imaging mass spectrometry and live-cell imaging reveal cardiac workload-dependent increases in NADH:NAD+ in intramyocardial arterial myocytes. Intracellular NAD(P)(H) redox ratios reflecting elevated oxygen demand potentiate native coronary Kv1 activity in a Kvβ2-dependent manner. Ablation of Kvβ2 catalysis suppresses redox-dependent increases in Kv1 activity, vasodilation, and the relationship between cardiac workload and myocardial blood flow. Collectively, this work suggests that the pyridine nucleotide sensitivity and enzymatic activity of Kvβ2 controls coronary vasoreactivity and myocardial blood flow during metabolic stress. Animal model, what strain, age, how many, experimental conditions: Genetically engineered mouse strains in which Kcnab1 or Kcnab2 genes were ablated (i.e., Kvβ1.1−/−, Kvβ2−/−, respectively) or in which tyrosine-90 of Kvβ2 was mutated to phenylalanine (Kvβ2Y90F) were used for this study. Strain-matched wild-type mice (WT; C57BL6N for Kvβ1.1−/−, 129SvEv for Kvβ2−/−) were used as controls. Due to the potential for confounding effects of estrogen on the functional expression of vascular K+ channels, only male mice (aged-3–6 months) were used. All mice were bred and maintained in-house and fed normal chow ad libitum in a temperature-controlled room on a continuous 12:12 h light:dark cycle. How was the project carried out? We used a combination of imaging mass spectrometry, live-cell fluorescence imaging, patch clamp electrophysiology, echocardiography, ex vivo arterial diameter measurements, in situ proximity ligation, and biochemical approaches, as described at length in the published article.

Categories

Funding

Licence