Dept of Mol & Pharmacol Neurosci, Grad Sch of Biomed & Health Sci, Hiroshima Univ, Japan; Dept of Anesthesiology ＆ Critical Care, Grad Sch of Biomed & Health Sci, Hiroshima Univ, Japan.
Dept of Mol & Pharmacol Neurosci, Grad Sch of Biomed & Health Sci, Hiroshima Univ, Japan.
Eur J Pharmacol. 2023 Sep 15;955:175806. doi: 10.1016/j.ejphar.2023.175806. Epub 2023 May 23.
Propofol is widely used for general anesthesia and sedation; however, the mechanisms of its anesthetic and adverse effects are not fully understood. We have previously shown that propofol activates protein kinase C (PKC) and induces its translocation in a subtype-specific manner. The purpose of this study was to identify the PKC domains involved in propofol-induced PKC translocation. The regulatory domains of PKC consist of C1 and C2 domains, and the C1 domain is subdivided into the C1A and C1B subdomains. Mutant PKCα and PKCδ with each domain deleted were fused with green fluorescent protein (GFP) and expressed in HeLa cells. Propofol-induced PKC translocation was observed by time-lapse imaging using a fluorescence microscope. The results showed that persistent propofol-induced PKC translocation to the plasma membrane was abolished by the deletion of both C1 and C2 domains in PKCα and by the deletion of the C1B domain in PKCδ. Therefore, propofol-induced PKC translocation involves the C1 and C2 domains of PKCα and the C1B domain of PKCδ. We also found that treatment with calphostin C, a C1 domain inhibitor, abolished propofol-induced PKCδ translocation. In addition, calphostin C inhibited the propofol-induced phosphorylation of endothelial nitric oxide synthase (eNOS). These results suggest that it may be possible to modulate the exertion of propofol effects by regulating the PKC domains involved in propofol-induced PKC translocation.
异丙酚广泛用于全身麻醉和镇静；然而，其麻醉和不良反应的机制尚未完全阐明。我们之前已经表明，异丙酚以亚型特异性方式激活蛋白激酶 C（PKC）并诱导其易位。本研究的目的是确定参与异丙酚诱导的 PKC 易位的 PKC 结构域。PKC 的调节结构域包括 C1 和 C2 结构域，C1 结构域进一步细分为 C1A 和 C1B 亚结构域。缺失每个结构域的突变 PKCα 和 PKCδ与绿色荧光蛋白（GFP）融合并在 HeLa 细胞中表达。通过荧光显微镜的延时成像观察到异丙酚诱导的 PKC 易位。结果表明，PKCα 的 C1 和 C2 结构域以及 PKCδ 的 C1B 结构域缺失均可消除持久的异丙酚诱导的 PKC 向质膜的易位。因此，异丙酚诱导的 PKC 易位涉及 PKCα 的 C1 和 C2 结构域以及 PKCδ 的 C1B 结构域。我们还发现，C1 结构域抑制剂钙调蛋白 C 可消除异丙酚诱导的 PKCδ 易位。此外，钙调蛋白 C 抑制了异丙酚诱导的内皮型一氧化氮合酶（eNOS）的磷酸化。这些结果表明，通过调节参与异丙酚诱导的 PKC 易位的 PKC 结构域，可能有可能调节异丙酚作用的发挥。
