Luong Trang T D, Schelski Nadeshda, Boehme Beate, Makridakis Manousos, Vlahou Antonia, Lang Florian, Pieske Burkert, Alesutan Ioana, Voelkl Jakob
Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Biomedical Research Foundation, Academy of Athens, Athens, Greece.
Cell Physiol Biochem. 2018;46(4):1305-1316. doi: 10.1159/000489144. Epub 2018 Apr 18.
BACKGROUND/AIMS: Fibulin-3, an extracellular matrix glycoprotein, inhibits vascular oxidative stress and remodeling in hypertension. Oxidative stress is prevalent in chronic kidney disease (CKD) patients and is an important mediator of osteo-/chondrogenic transdifferentiation and calcification of vascular smooth muscle cells (VSMCs) during hyperphosphatemia. Therefore, the present study explored the effects of Fibulin-3 on phosphate-induced vascular calcification.
Experiments were performed in primary human aortic smooth muscle cells (HAoSMCs) treated with control or with phosphate without or with additional treatment with recombinant human Fibulin-3 protein or with hydrogen peroxide as an exogenous source of oxidative stress.
Treatment with calcification medium significantly increased calcium deposition in HAoSMCs, an effect significantly blunted by additional treatment with Fibulin-3. Moreover, phosphate-induced alkaline phosphatase activity and mRNA expression of osteogenic and chondrogenic markers MSX2, CBFA1, SOX9 and ALPL were all significantly reduced by addition of Fibulin-3. These effects were paralleled by similar regulation of oxidative stress in HAoSMCs. Phosphate treatment significantly up-regulated mRNA expression of the oxidative stress markers NOX4 and CYBA, down-regulated total antioxidant capacity and increased the expression of downstream effectors of oxidative stress PAI-1, MMP2 and MMP9 as well as BAX/BLC2 ratio in HAoSMCs, all effects blocked by additional treatment with Fibulin-3. Furthermore, the protective effects of Fibulin-3 on phosphate-induced osteogenic and chondrogenic markers expression in HAoSMCs were reversed by additional treatment with hydrogen peroxide.
Fibulin-3 attenuates phosphate-induced osteo-/ chondrogenic transdifferentiation and calcification of VSMCs, effects involving inhibition of oxidative stress. Up-regulation or supplementation of Fibulin-3 may be beneficial in reducing the progression of vascular calcification during hyperphosphatemic conditions such as CKD.
背景/目的：纤连蛋白-3是一种细胞外基质糖蛋白，可抑制高血压中的血管氧化应激和重塑。氧化应激在慢性肾脏病（CKD）患者中普遍存在，并且是高磷血症期间血管平滑肌细胞（VSMC）骨/软骨生成转分化和钙化的重要介质。因此，本研究探讨了纤连蛋白-3对磷酸盐诱导的血管钙化的影响。
在原代人主动脉平滑肌细胞（HAoSMC）中进行实验，这些细胞用对照处理，或用磷酸盐处理，同时或不同时额外用重组人纤连蛋白-3蛋白处理，或用过氧化氢作为氧化应激的外源性来源处理。
用钙化培养基处理显著增加了HAoSMC中的钙沉积，而额外用纤连蛋白-3处理可显著减弱该效应。此外，添加纤连蛋白-3可显著降低磷酸盐诱导的碱性磷酸酶活性以及成骨和软骨生成标志物MSX2、CBFA1、SOX9和ALPL的mRNA表达。HAoSMC中氧化应激的类似调节与这些效应平行。磷酸盐处理显著上调了氧化应激标志物NOX4和CYBA的mRNA表达，下调了总抗氧化能力，并增加了氧化应激下游效应物PAI-1、MMP2和MMP9的表达以及HAoSMC中BAX/BLC2比值，所有这些效应均被额外用纤连蛋白-3处理所阻断。此外，用过氧化氢额外处理可逆转纤连蛋白-3对磷酸盐诱导的HAoSMC中成骨和软骨生成标志物表达的保护作用。
纤连蛋白-3减弱了磷酸盐诱导的VSMC骨/软骨生成转分化和钙化，其作用涉及抑制氧化应激。上调或补充纤连蛋白-3可能有利于减少高磷血症状态（如CKD）期间血管钙化的进展。
