Adenylyl cyclase isoform 1 contributes to sinoatrial node automaticity via functional microdomains.

Autor:	Ren L; Department of Internal Medicine, Division of Cardiovascular Medicine, UCD, Davis, California, USA.; Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, California, USA., Thai PN; Department of Internal Medicine, Division of Cardiovascular Medicine, UCD, Davis, California, USA.; Department of Veteran Affairs, Northern California Health Care System, Sacramento, California, USA., Gopireddy RR; Department of Pharmacology, UCD, Davis, California, USA., Timofeyev V; Department of Internal Medicine, Division of Cardiovascular Medicine, UCD, Davis, California, USA., Ledford HA; Department of Internal Medicine, Division of Cardiovascular Medicine, UCD, Davis, California, USA., Woltz RL; Department of Internal Medicine, Division of Cardiovascular Medicine, UCD, Davis, California, USA.; Department of Veteran Affairs, Northern California Health Care System, Sacramento, California, USA., Park S; Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, Nevada, USA.; Prestige Biopharma Korea, Myongjigukje 7-ro, Gangseo-gu, Busan, South Korea., Puglisi JL; College of Medicine. California North State University, Sacramento, California, USA., Moreno CM; Department of Physiology and Membrane Biology, UCD, Davis, California, USA.; Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington, USA., Santana LF; Department of Physiology and Membrane Biology, UCD, Davis, California, USA., Conti AC; Research & Development Service, John D. Dingell VA Medical Center, and.; Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, Michigan, USA., Kotlikoff MI; College of Veterinary Medicine, Cornell University, Ithaca, New York, USA., Xiang YK; Department of Veteran Affairs, Northern California Health Care System, Sacramento, California, USA.; Department of Pharmacology, UCD, Davis, California, USA., Yarov-Yarovoy V; Department of Physiology and Membrane Biology, UCD, Davis, California, USA., Zaccolo M; Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom., Zhang XD; Department of Internal Medicine, Division of Cardiovascular Medicine, UCD, Davis, California, USA.; Department of Veteran Affairs, Northern California Health Care System, Sacramento, California, USA., Yamoah EN; Department of Physiology and Cell Biology, University of Nevada, Reno, Reno, Nevada, USA., Navedo MF; Department of Pharmacology, UCD, Davis, California, USA., Chiamvimonvat N; Department of Internal Medicine, Division of Cardiovascular Medicine, UCD, Davis, California, USA.; Department of Veteran Affairs, Northern California Health Care System, Sacramento, California, USA.; Department of Pharmacology, UCD, Davis, California, USA.
Jazyk:	angličtina
Zdroj:	JCI insight [JCI Insight] 2022 Nov 22; Vol. 7 (22). Date of Electronic Publication: 2022 Nov 22.
DOI:	10.1172/jci.insight.162602
Abstrakt:	Sinoatrial node (SAN) cells are the heart's primary pacemaker. Their activity is tightly regulated by β-adrenergic receptor (β-AR) signaling. Adenylyl cyclase (AC) is a key enzyme in the β-AR pathway that catalyzes the production of cAMP. There are current gaps in our knowledge regarding the dominant AC isoforms and the specific roles of Ca2+-activated ACs in the SAN. The current study tests the hypothesis that distinct AC isoforms are preferentially expressed in the SAN and compartmentalize within microdomains to orchestrate heart rate regulation during β-AR signaling. In contrast to atrial and ventricular myocytes, SAN cells express a diverse repertoire of ACs, with ACI as the predominant Ca2+-activated isoform. Although ACI-KO (ACI-/-) mice exhibit normal cardiac systolic or diastolic function, they experience SAN dysfunction. Similarly, SAN-specific CRISPR/Cas9-mediated gene silencing of ACI results in sinus node dysfunction. Mechanistically, hyperpolarization-activated cyclic nucleotide-gated 4 (HCN4) channels form functional microdomains almost exclusively with ACI, while ryanodine receptor and L-type Ca2+ channels likely compartmentalize with ACI and other AC isoforms. In contrast, there were no significant differences in T-type Ca2+ and Na+ currents at baseline or after β-AR stimulation between WT and ACI-/- SAN cells. Due to its central characteristic feature as a Ca2+-activated isoform, ACI plays a unique role in sustaining the rise of local cAMP and heart rates during β-AR stimulation. The findings provide insights into the critical roles of the Ca2+-activated isoform of AC in sustaining SAN automaticity that is distinct from contractile cardiomyocytes.
Databáze:	MEDLINE
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