Cyclic stretch stimulates vascular smooth muscle cell alignment by redox-dependent activation of Notch3.
Cyclic stretch stimulates vascular smooth muscle cell alignment by redox-dependent activation of Notch3.
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DOI：
10.1152/ajpheart.00535.2010
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发表时间：
2011-05
期刊：
影响因子：
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通讯作者：
Jian Zhu;Chun-Lin Chen;S. Flavahan;Jennifer C. Harr;B. Su;N. Flavahan
中科院分区：
文献类型：
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作者：
Jian Zhu;Chun-Lin Chen;S. Flavahan;Jennifer C. Harr;B. Su;N. Flavahan
Notch 3缺陷的小鼠在动脉血管平滑肌细胞（VSMC）机械敏感性方面存在缺陷，包括生肌反应和自动调节受损以及VMSC方向不当。进行实验以确定Notch 3是否被机械刺激激活并有助于VSMC的机械敏感性反应，包括细胞重新排列。周期性的，单轴拉伸（10%，1 Hz）的人血管平滑肌细胞引起的Notch 3激活，证明了拉伸诱导的毛和分裂增强子1/毛相关的转录因子-1的表达，易位Notch 3的细胞核，和减少Notch 3的细胞外结构域。通过抑制Notch 3的表达[小干扰（si）RNA]或蛋白水解激活来防止这些作用。（羟氨基羰基）甲基]-4-甲基戊酰基-1-萘基丙氨酰基-1-丙氨酸-2-氨基乙基酰胺（TAPI-1; 50 μmol/l）抑制TNF-α转化酶（TACE）或N-[N-（3，5-二氟苯乙酰基-1-丙氨酰）]-S-苯基甘氨酸叔丁酯（DAPT; 20 μmol/l）抑制γ-分泌酶}。拉伸增加活性的活性氧在血管平滑肌细胞，确定使用二氯二氢荧光素荧光。过氧化氢酶（1，200 U/ml）可降解HNO 3，抑制拉伸诱导的Notch 3激活，而在未拉伸的细胞中，增加HNO 3活性[HNO 3或锰（III）四（1-甲基-4-吡啶基）卟啉]可激活Notch 3。牵张可增加TACE的活性，但可被过氧化氢酶阻止。牵张诱导的VSMCs中p38 MAPK的激活被过氧化氢酶或抑制Notch 3表达（siRNA）抑制。拉伸导致VSMC重新排列垂直于机械刺激的方向，这被过氧化氢酶或通过抑制Notch 3（TAPI-1或DAPT）的表达（siRNA）或激活而显著抑制。因此，周期性单轴拉伸通过ROS介导的机制激活Notch 3信号传导，并且Notch 3的存在对于VSMC中适当的拉伸诱导的细胞排列是必要的。这一机制可能有助于Notch 3介导VSMC发育成熟的生理作用。
Mice deficient in Notch3 have defects in arterial vascular smooth muscle cell (VSMC) mechanosensitivity, including impaired myogenic responses and autoregulation, and inappropriate VMSC orientation. Experiments were performed to determine if Notch3 is activated by mechanical stimulation and contributes to mechanosensitive responses of VSMCs, including cell realignment. Cyclic, uniaxial stretch (10%, 1 Hz) of human VSMCs caused Notch3 activation, demonstrated by a stretch-induced increase in hairy and enhancer of split 1/hairy-related transcription factor-1 expression, translocation of Notch3 to the nucleus, and a decrease in the Notch3 extracellular domain. These effects were prevented by inhibiting the expression [small interfering (si)RNA] or proteolytic activation of Notch3 {N-(R)-[2-(hydroxyaminocarbonyl)methyl]-4-methylpentanoyl-l-naphthylalanyl-l-alanine-2-aminoethyl amide (TAPI-1; 50 μmol/l) to inhibit TNF-α-converting enzyme (TACE) or N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester (DAPT; 20 μmol/l) to inhibit γ-secretase}. Stretch increased the activity of ROS within VSMCs, determined using dichlorodihydrofluorescein fluorescence. Catalase (1,200 U/ml), which degrades H₂O₂, inhibited the stretch-induced activation of Notch3, whereas in nonstretched cells, increasing H₂O₂ activity [H₂O₂ or manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin] caused activation of Notch3. Stretch increased the activity of TACE, which was prevented by catalase. Stretch-induced activation of p38 MAPK in VSMCs was inhibited either by catalase or by inhibiting Notch3 expression (siRNA). Stretch caused VSMCs to realign perpendicular to the direction of the mechanical stimulus, which was significantly inhibited by catalase or by inhibiting the expression (siRNA) or activation of Notch3 (TAPI-1 or DAPT). Therefore, cyclic uniaxial stretch activates Notch3 signaling through a ROS-mediated mechanism, and the presence of Notch3 is necessary for proper stretch-induced cell alignment in VSMCs. This mechanism may contribute to the physiological role of Notch3 in mediating developmental maturation of VSMCs.