Department of Pediatric Surgery, Children's Hospital of Fudan University, Shanghai, 201102, China.
J Pediatr Surg. 2012 Dec;47(12):2216-23. doi: 10.1016/j.jpedsurg.2012.09.008.
BACKGROUND/PURPOSE: Propranolol, a non-selective beta-blocker, has recently been introduced as a novel treatment modality for proliferating hemangiomas. However, the mechanism of action of this therapy is unknown. In this study, we investigated propranolol in the etiology of hemangiomas that are associated with the proliferation and apoptosis of hemangioma-derived endothelial cells (HemECs).
HemECs were isolated from freshly resected hemangioma specimens. We studied propranolol-treated HemECs in vitro. We measured the effect of propranolol on HemEC viability using the Cell Counting Kit-8 (CCK-8) assay and proliferation and apoptosis using a BrdU labeling assay, annexin-V-fluorescein isothiocyanate/propidium iodide flow cytometry, and Hoechst 33342 fluorescent staining. We explored the potential mechanisms of propranolol-induced HemEC dysfunction using western blot analysis, a caspase assay kit, and real-time quantitative PCR.
We observed that propranolol had inhibitory effects on the viability and proliferation of HemECs. HemEC apoptosis significantly increased with 100 μM propranolol treatment. Vascular endothelial growth factor (VEGF) expression was down-regulated by propranolol in a dose-dependent manner. We also demonstrated activation of the caspase cascade, including caspase-9 and caspase-3 of the intrinsic pathway, and an increased p53 gene expression and Bax/Bcl-xL ratio in HemECs treated with 100 μM propranolol.
We obtained novel data that suggests propranolol could inhibit HemEC proliferation and induce apoptosis. The effects were likely mediated through the suppression of VEGF expression, activation of caspase-9 and caspase-3, up-regulation of the pro-apoptotic genes p53 and Bax and down-regulation of the anti-apoptotic gene Bcl-xL.
背景/目的：普萘洛尔是一种非选择性β受体阻滞剂，最近被引入作为增生性血管瘤的一种新的治疗方法。然而，这种治疗的作用机制尚不清楚。在这项研究中，我们研究了普萘洛尔在与血管瘤衍生内皮细胞（HemECs）增殖和凋亡相关的血管瘤发病机制中的作用。
从新鲜切除的血管瘤标本中分离出 HemECs。我们在体外研究了普萘洛尔处理的 HemECs。我们使用细胞计数试剂盒-8（CCK-8）测定法测量普萘洛尔对 HemEC 活力的影响，并用 BrdU 标记测定法、 Annexin-V-异硫氰酸荧光素/碘化丙啶流式细胞术和 Hoechst 33342 荧光染色法测量增殖和凋亡。我们使用 Western blot 分析、半胱天冬酶测定试剂盒和实时定量 PCR 探索了普萘洛尔诱导的 HemEC 功能障碍的潜在机制。
我们观察到普萘洛尔对 HemEC 的活力和增殖具有抑制作用。100 μM 普萘洛尔处理后，HemEC 凋亡显著增加。血管内皮生长因子（VEGF）表达呈剂量依赖性下调。我们还证明了内在途径中的 caspase-9 和 caspase-3 以及 HemEC 中 p53 基因表达和 Bax/Bcl-xL 比值的增加被 100 μM 普萘洛尔激活。
我们获得了新的数据表明，普萘洛尔可以抑制 HemEC 的增殖并诱导凋亡。这些作用可能是通过抑制 VEGF 表达、激活 caspase-9 和 caspase-3、上调促凋亡基因 p53 和 Bax 以及下调抗凋亡基因 Bcl-xL 来介导的。
