Department of Sport and Health Studies, College of Biomedical and Health Science, Konkuk University, Chungju 27478, Republic of Korea; Sports Convergence Institute, Konkuk University, Chungju 27478, Republic of Korea; Center for Metabolic Diseases, Konkuk University, Chungju 27478, Republic of Korea; Research Institute for Biomedical & Health Science, Chungju 27478, Republic of Korea.
Department of Physiology, KU Open Innovation Center, Research Institute of Medical Science, Konkuk University School of Medicine, Chungju 27478, Republic of Korea.
Life Sci. 2023 Sep 1;328:121903. doi: 10.1016/j.lfs.2023.121903. Epub 2023 Jun 30.
Caveolae are invaginated, Ω-shaped membrane structures. They are now recognized as portals for signal transduction of multiple chemical and mechanical stimuli. Notably, the contribution of caveolae has been reported to be receptor-specific. However, details of how they differentially contribute to receptor signaling remain unclear.
Using isometric tension measurements, patch-clamping, and western blotting, we examined the contribution of caveolae and their related signaling pathways to serotonergic (5-HT receptor-mediated) and adrenergic (α1-adrenoceptor-mediated) signaling in rat mesenteric arteries.
Disruption of caveolae by methyl-β-cyclodextrin effectively blocked vasoconstriction mediated by the 5-HT receptor (5-HTR), but not by the α1-adrenoceptor. Caveolar disruption selectively impaired 5-HTR-mediated voltage-dependent K channel (Kv) inhibition, but not α1-adrenoceptor-mediated Kv inhibition. In contrast, both serotonergic and α1-adrenergic effects on vasoconstriction, as well as Kv currents, were similarly blocked by the Src tyrosine kinase inhibitor PP. However, inhibition of protein kinase C (PKC) by either GO6976 or chelerythrine selectively attenuated the effects mediated by the α1-adrenoceptor, but not by 5-HTR. Disruption of caveolae decreased 5-HTR-mediated Src phosphorylation, but not α1-adrenoceptor-mediated Src phosphorylation. Finally, the PKC inhibitor GO6976 blocked Src phosphorylation by the α1-adrenoceptor, but not by 5-HTR.
5-HTR-mediated Kv inhibition and vasoconstriction are dependent on caveolar integrity and Src tyrosine kinase, but not on PKC. In contrast, α1-adrenoceptor-mediated Kv inhibition and vasoconstriction are not dependent on caveolar integrity, but rather on PKC and Src tyrosine kinase. Caveolae-independent PKC is upstream of Src activation for α1-adrenoceptor-mediated Kv inhibition and vasoconstriction.
陷窝是内陷的、Ω 形的膜结构。现在，它们被认为是多种化学和机械刺激信号转导的门户。值得注意的是，陷窝的贡献被报道是受体特异性的。然而，它们如何差异地贡献于受体信号的细节仍不清楚。
使用等长张力测量、膜片钳和 Western 印迹，我们研究了陷窝及其相关信号通路对大鼠肠系膜动脉中 5-羟色胺能（5-HT 受体介导）和肾上腺素能（α1-肾上腺素能受体介导）信号的贡献。
甲基-β-环糊精破坏陷窝有效地阻断了 5-HT 受体（5-HTR）介导的血管收缩，但不阻断 α1-肾上腺素能受体介导的血管收缩。陷窝破坏选择性损害了 5-HTR 介导的电压依赖性 K 通道（Kv）抑制，但不损害 α1-肾上腺素能受体介导的 Kv 抑制。相反，5-羟色胺能和 α1-肾上腺素能对血管收缩以及 Kv 电流的作用都被Src 酪氨酸激酶抑制剂 PP 类似地阻断。然而，Src 酪氨酸激酶抑制剂 PP 选择性地抑制蛋白激酶 C（PKC）通过 GO6976 或 Chelerythrine 抑制了由 α1-肾上腺素能受体介导的作用，但不抑制由 5-HTR 介导的作用。陷窝破坏降低了 5-HTR 介导的Src 磷酸化，但不降低 α1-肾上腺素能受体介导的Src 磷酸化。最后，PKC 抑制剂 GO6976 阻断了 α1-肾上腺素能受体介导的Src 磷酸化，但不阻断 5-HTR 介导的Src 磷酸化。
5-HTR 介导的 Kv 抑制和血管收缩依赖于陷窝的完整性和 Src 酪氨酸激酶，但不依赖于 PKC。相反，α1-肾上腺素能受体介导的 Kv 抑制和血管收缩不依赖于陷窝的完整性，而是依赖于 PKC 和 Src 酪氨酸激酶。PKC 对于α1-肾上腺素能受体介导的 Kv 抑制和血管收缩的 Src 激活是陷窝独立的。
