Vascular smooth muscle LRP6 limits arteriosclerotic calcification in diabetic LDLR-/- mice by restraining noncanonical Wnt signals.
Vascular smooth muscle LRP6 limits arteriosclerotic calcification in diabetic LDLR-/- mice by restraining noncanonical Wnt signals.
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DOI：
10.1161/circresaha.117.306712
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发表时间：
2015-07-03
影响因子：
20.1
通讯作者：
Towler DA
中科院分区：
文献类型：
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作者：
Cheng SL;Ramachandran B;Behrmann A;Shao JS;Mead M;Smith C;Krchma K;Bello Arredondo Y;Kovacs A;Kapoor K;Brill LM;Perera R;Williams BO;Towler DA
Wnt信号调节糖尿病血管疾病的关键方面。我们合成了SM 22-Cre; LRP 6（fl/fl）;图10示出了LDLR-/-小鼠的血管平滑肌谱系（VSM）的Wnt共受体LRP 6的分布，以确定Wnt共受体LRP 6在雄性LDLR缺失小鼠的血管平滑肌谱系（VSM）中的贡献，所述VSM是对饮食（HFD）诱导的糖尿病动脉硬化敏感的背景。与LRP 6（fl/fl）;LDLR-/-对照相比，SM 22-Cre; LRP 6（fl/fl）;LDLR-/-（LRP 6-VKO）同胞在HFD时显示主动脉钙化增加，而空腹血糖、血脂或身体组成无变化。脉搏波速度（动脉硬度指数）也增加。血管钙化促进了主动脉骨软骨形成和循环骨桥蛋白（OPN），一种动脉硬化的基质细胞调节剂。LRP 6-VKO中配体和卷曲（Fzd）受体谱的调查显示，经典和非经典Wnt与Fzd 10一起上调。Fzd 10通过LRP 6抑制的USF激活同源物刺激非经典信号传导和OPN启动子活性。RNAi显示USF 1而不是USF 2支持LRP 6-VKO VSM中的OPN表达，免疫沉淀证实USF 1与OPN染色质的结合增加。ML 141是cdc 42/Rac 1非经典信号传导的拮抗剂，可抑制USF 1活化、骨软骨形成程序、碱性磷酸酶和VSM钙化。质谱鉴定了LRP 6与蛋白质精氨酸甲基转移酶（PRMT）-1结合，并且核不对称二甲基精氨酸修饰随着LRP 6-VKO而增加。RNAi证实PRMT 1抑制OPN和TNAP，而PRMT 4支持表达。含有PRMT 4的H3 R17 Me 2a特征的USF 1复合物随着LRP 6-VKO而增加。Jmjd 6是一种因LRP 6缺陷而下调的脱甲基酶，抑制OPN和TNAP表达、USF 1：H3 R17 Me 2a复合物形成和反式激活。LRP 6抑制VSM非经典信号，促进骨软骨分化，部分介导的USF 1和精氨酸甲基化依赖性继电器。
Wnt signaling regulates key aspects of diabetic vascular disease. We generated SM22-Cre;LRP6(fl/fl);LDLR-/- mice to determine contributions of Wnt co-receptor LRP6 in the vascular smooth muscle lineage (VSM) of male LDLR-null mice, a background susceptible to diet (HFD) - induced diabetic arteriosclerosis. As compared to LRP6(fl/fl);LDLR-/- controls, SM22-Cre;LRP6(fl/fl);LDLR-/- (LRP6-VKO) siblings exhibited increased aortic calcification on HFD without changes in fasting glucose, lipids, or body composition. Pulse wave velocity (index of arterial stiffness) was also increased. Vascular calcification paralleled enhanced aortic osteochondrogenic programs and circulating osteopontin (OPN), a matricellular regulator of arteriosclerosis. Survey of ligands and Frizzled (Fzd) receptor profiles in LRP6-VKO revealed upregulation of canonical and noncanonical Wnts alongside Fzd10. Fzd10 stimulated noncanonical signaling and OPN promoter activity via an USF-activated cognate inhibited by LRP6. RNAi revealed that USF1 but not USF2 supports OPN expression in LRP6-VKO VSM, and immunoprecipitation confirmed increased USF1 association with OPN chromatin. ML141, an antagonist of cdc42/Rac1 noncanonical signaling, inhibited USF1 activation, osteochondrogenic programs, alkaline phosphatase, and VSM calcification. Mass spectrometry identified LRP6 binding to protein arginine methyltransferase (PRMT) - 1, and nuclear asymmetric dimethylarginine modification was increased with LRP6-VKO. RNAi demonstrated that PRMT1 inhibits OPN and TNAP while PRMT4 supports expression. USF1 complexes containing the H3R17Me2a signature of PRMT4 are increased with LRP6-VKO. Jmjd6, a demethylase downregulated with LRP6 deficiency, inhibits OPN and TNAP expression, USF1:H3R17Me2a complex formation and transactivation. LRP6 restrains VSM noncanonical signals that promote osteochondrogenic differentiation, mediated in part via USF1- and arginine methylation – dependent relays.