Freise Christian, Bobb Veronika, Querfeld Uwe
Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Pediatric Nephrology, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany; Center for Cardiovascular Research, Charité - Universitätsmedizin Berlin, Campus Mitte, Hessische Str. 3-4, 10115 Berlin, Germany.
Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Pediatric Nephrology, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany; Center for Cardiovascular Research, Charité - Universitätsmedizin Berlin, Campus Mitte, Hessische Str. 3-4, 10115 Berlin, Germany.
Exp Cell Res. 2017 Sep 15;358(2):242-252. doi: 10.1016/j.yexcr.2017.06.018. Epub 2017 Jun 26.
Transdifferentiation of vascular smooth muscle cells (VSMC) promotes the development of vascular calcifications such as arteriosclerosis. The aim was to investigate effects of specific extracellular matrix (ECM) components on transdifferentiation of VSMC to identify novel ECM-based therapeutic tools. Human collagens I & IV (CI, CIV) along with collagen XIV (CXIV) and a CXIV-derived fragment (CXIV-F), both of which induce differentiation, were applied in an in-vitro model of calcium-/phosphate (Ca/P)-induced osteochondrocytic transdifferentiation of human and murine VSMC. Transdifferentiation was determined by RT-PCR and calcium contents of VSMC cultures. Signaling pathways involved were determined by western-blot and luciferase reporter plasmid assays. Under normal culture conditions, CI induced VSMC proliferation and a more epithelioid/synthetic phenotype while CIV and predominantly CXIV provoked opposite effects. CIV and CXIV further blocked Ca/P-induced osteochondrocytic transdifferentiation of VSMC displayed e.g. by reduced gene expressions of Runx2, Sox9, osterix and increased expressions of αSMA and SM22α. This involved impaired activation of ERK1/2, NF-ĸB and Wnt-signaling. Similar preventive effects were achieved by applying CXIV-F. Impaired preventive effects of CXIV by co-treatment with a cluster of differentiation (CD)44 agonist propose CD44 as a CXIV-target structure on VSMC. In conclusion, CXIV and CXIV-F interfere with osteochondrocytic transdifferentiation of VSMC and should be further explored as potential therapeutic tools in vascular calcification.
血管平滑肌细胞（VSMC）的转分化促进了诸如动脉硬化等血管钙化的发展。本研究旨在探讨特定细胞外基质（ECM）成分对VSMC转分化的影响，以确定新型的基于ECM的治疗工具。将人I型和IV型胶原蛋白（CI、CIV）以及可诱导分化的胶原蛋白XIV（CXIV）和CXIV衍生片段（CXIV-F）应用于人和小鼠VSMC的钙/磷酸盐（Ca/P）诱导的骨软骨细胞转分化体外模型中。通过RT-PCR和VSMC培养物的钙含量来确定转分化情况。通过蛋白质免疫印迹和荧光素酶报告质粒分析来确定相关的信号通路。在正常培养条件下，CI诱导VSMC增殖并使其呈现更上皮样/合成型表型，而CIV和主要是CXIV则产生相反的作用。CIV和CXIV进一步阻断了Ca/P诱导的VSMC骨软骨细胞转分化，例如表现为Runx2、Sox9、osterix基因表达降低以及αSMA和SM22α表达增加。这涉及到细胞外信号调节激酶1/2（ERK1/2）、核因子κB（NF-κB）和Wnt信号通路的激活受损。应用CXIV-F也取得了类似的预防效果。通过与分化簇（CD）44激动剂共同处理，CXIV的预防作用受损，提示CD44是VSMC上CXIV的靶向结构。总之，CXIV和CXIV-F干扰了VSMC的骨软骨细胞转分化，应进一步探索其作为血管钙化潜在治疗工具的可能性。
