骨化三醇通过激活组蛋白去乙酰化酶下调 HL-1 心房肌细胞成纤维细胞生长因子受体 1。
Calcitriol downregulates fibroblast growth factor receptor 1 through histone deacetylase activation in HL-1 atrial myocytes.
机构信息
Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, 250 Wu-Xing Street, Taipei, 11031, Taiwan.
Division of Endocrinology and Metabolism, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
出版信息
J Biomed Sci. 2018 May 18;25(1):42. doi: 10.1186/s12929-018-0443-3.
BACKGROUND
Fibroblast growth factor (FGF)-2 plays a crucial role in the pathophysiology of cardiovascular diseases (CVDs). FGF-2 was reported to induce cardiac hypertrophy through activation of FGF receptor 1 (FGFR1). Multiple laboratory findings indicate that calcitriol may be a potential treatment for CVDs. In this study, we attempted to investigate whether calcitriol regulates FGFR1 expression to modulate the effects of FGF-2 signaling in cardiac myocytes and explored the potential regulatory mechanism.
METHODS
Western blot, polymerase chain reaction, small interfering RNA, fluorometric activity assay, and chromatin immunoprecipitation (ChIP) analyses were used to evaluate FGFR1, FGFR2, FGFR3, FGFR4, phosphorylated extracellular signal-regulated kinase (p-ERK), β-myosin heavy chain (β-MHC), phosphorylated phospholipase Cγ (p-PLCγ), nuclear factor of activated T cells (NFAT), and histone deacetylase (HDAC) expressions and enzyme activities in HL-1 atrial myocytes without and with calcitriol (1 and 10 nM) treatment, in the absence and presence of FGF-2 (25 ng/mL) or suberanilohydroxamic acid (SAHA, a pan-HDAC inhibitor, 1 μM).
RESULTS
We found that calcitriol-treated HL-1 cells had significantly reduced FGFR1 expression compared to control cells. In contrast, expressions of FGFR2, FGFR3, and FGFR4 were similar between calcitriol-treated and control HL-1 cells. FGF-2-treated HL-1 cells had similar PLCγ phosphorylation and nuclear/cytoplasmic NFAT expressions compared to control cells. FGF-2 induced lower expressions of p-ERK and β-MHC in calcitriol-treated HL-1 cells than in control cells. FGFR1-knockdown blocked FGF-2 signaling and reversed the protective effects of calcitriol. Compared to control cells, calcitriol-treated HL-1 cells had higher nuclear HDAC activity. The ChIP analysis demonstrated a significant decrease in acetyl-histone H4, which is associated with an increase in HDAC3 in the FGFR1 promoter. Calcitriol-mediated FGFR1 downregulation was attenuated in the presence of SAHA.
CONCLUSIONS
Calcitriol diminished FGFR1 expression through HDAC activation, which ameliorated the harmful effects of FGF-2 on cardiac myocytes.
背景
成纤维细胞生长因子 (FGF)-2 在心血管疾病 (CVD) 的病理生理学中起着至关重要的作用。据报道，FGF-2 通过激活成纤维细胞生长因子受体 1 (FGFR1) 诱导心肌细胞肥大。多项实验室研究结果表明，骨化三醇可能是 CVD 的一种潜在治疗方法。在这项研究中，我们试图探讨骨化三醇是否通过调节 FGFR1 表达来调节心肌细胞中 FGF-2 信号的作用，并探讨潜在的调节机制。
方法
使用 Western blot、聚合酶链反应、小干扰 RNA、荧光酶活性测定和染色质免疫沉淀 (ChIP) 分析来评估无和有骨化三醇 (1 和 10 nM) 处理、无和有 FGF-2 (25 ng/mL) 或苏贝替酸 (SAHA，一种泛组蛋白去乙酰化酶抑制剂，1 μM) 处理的 HL-1 心房心肌细胞中的 FGFR1、FGFR2、FGFR3、FGFR4、磷酸化细胞外信号调节激酶 (p-ERK)、β-肌球蛋白重链 (β-MHC)、磷酸化磷酯酶 Cγ (p-PLCγ)、活化 T 细胞核因子 (NFAT) 和组蛋白去乙酰化酶 (HDAC) 的表达和酶活性。
结果
我们发现，与对照组细胞相比，骨化三醇处理的 HL-1 细胞的 FGFR1 表达明显降低。相比之下，骨化三醇处理和对照组 HL-1 细胞的 FGFR2、FGFR3 和 FGFR4 表达相似。与对照组细胞相比，FGF-2 处理的 HL-1 细胞的 PLCγ 磷酸化和核/细胞质 NFAT 表达相似。与对照组细胞相比，FGF-2 在骨化三醇处理的 HL-1 细胞中诱导的 p-ERK 和 β-MHC 表达较低。FGFR1 敲低阻断了 FGF-2 信号，并逆转了骨化三醇的保护作用。与对照组细胞相比，骨化三醇处理的 HL-1 细胞的核 HDAC 活性更高。ChIP 分析表明，与乙酰化组蛋白 H4 相关的 FGFR1 启动子中的 HDAC3 增加，导致组蛋白 H4 乙酰化减少。SAHA 的存在减弱了骨化三醇介导的 FGFR1 下调。
结论
骨化三醇通过激活 HDAC 来减少 FGFR1 表达，从而减轻 FGF-2 对心肌细胞的有害作用。
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