CGRP derived from cardiac fibroblasts is an endogenous suppressor of cardiac fibrosis
CGRP derived from cardiac fibroblasts is an endogenous suppressor of cardiac fibrosis
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源自心脏成纤维细胞的 CGRP 是心脏纤维化的内源性抑制因子。
DOI：
10.1093/cvr/cvz234
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发表时间：
2020-06-01
影响因子：
10.8
通讯作者：
Li, Yuanjian
中科院分区：
文献类型：
--
作者：
Li, Wenqun;Zhang, Zheng;Li, Yuanjian
心脏成纤维细胞的异常激活导致心脏纤维化，不断发展的证据表明，心脏成纤维细胞来源的内源性生物活性物质以自分泌/旁分泌的方式调节心脏成纤维细胞的激活。本研究首次发现心肌成纤维细胞具有合成和分泌降钙素基因相关肽（calcitonin generelated peptide，CGRP）的功能，因此本研究旨在探讨心肌成纤维细胞来源的CGRP在心肌成纤维细胞活化中的作用及其调控机制。发现心脏CGRP主要来源于心脏成纤维细胞。用特异性激动剂异硫氰酸烯丙酯激活TRPA 1促进CGRP的合成和分泌，以及细胞内Ca 2+。TRPA 1特异性拮抗剂HC 030031和钙离子螯合剂BAPTA-AM可逆转上述作用。应用TGF-β 1诱导心脏成纤维细胞活化，发现TGF-β 1可增加心脏成纤维细胞CGRP的mRNA表达和分泌水平。CGRP 8 -37（CGRP受体拮抗剂）或α-CGRP小干扰RNA（siRNA）均加重TGF-β 1诱导的心脏成纤维细胞增殖、分化、胶原蛋白产生并引发炎症。此外，CGRP 8 -37和alpha-CGRP siRNA也促进TGF-β 1诱导的NF-κ B活化，包括I κ B α磷酸化和p65核转位。NF-κ B抑制剂吡咯烷二硫代氨基甲酸铵（PDTC）逆转CGRP 8 -37对NF-κ B活化的影响。CGRP 8 -37对TGF-β 1诱导的心肌成纤维细胞活化的促进作用可被PDTC逆转。野百合碱（MCT）诱导肺动脉高压，逐渐导致右心室纤维化。该心脏纤维化模型是为了测试TRPA 1激活在体内的潜在有益作用而开发的。无毒TRPA 1激动剂肉桂醛（CA）可抑制MCT诱导的右心室收缩压、RV/LV+S和右心室胶原积聚升高以及CGRP下调。结论心肌成纤维细胞来源的CGRP可能通过抑制NF-κ B B的活化而抑制心肌成纤维细胞的活化。通过激活TRPA 1增加自分泌CGRP可改善心脏纤维化。这些发现支持了这样的观点，即来源于心脏成纤维细胞的CGRP是心脏纤维化的内源性抑制因子。
Aims Aberrant activation of cardiac fibroblasts leads to cardiac fibrosis, and evolving evidences suggest that endogenous bioactive substances derived from cardiac fibroblasts regulate cardiac fibroblasts activation in an autocrine/paracrine manner. Here we first presented evidence that cardiac fibroblasts can synthesize and secrete calcitonin generelated peptide (CGRP), therefore, this study aimed to investigate the role of cardiac fibroblasts-derived CGRP in cardiac fibroblasts activation and its regulative mechanism.Methods and results The abundantly expression of CGRP in rat, mouse, and human myocardium allowed us to explore the cellular origin of CGRP, and found that the cardiac CGRP was mainly derived from cardiac fibroblasts. Activating TRPA1 with a specific agonist allyl isothiocyanate promoted the synthesis and secretion of CGRP, as well as intracellular Ca2+. These effects were reversed by TRPA1-specific antagonist HC030031 and Ca2+ chelator BAPTA-AM. TGF-beta 1 was applied to induce the activation of cardiac fibroblasts, and found that TGF-b1 can increase the mRNA expression and secretion levels of CGRP in cardiac fibroblasts. Either CGRP8-37 (CGRP receptor antagonist) or alpha-CGRP small interfering RNA (siRNA) aggravated TGF-beta 1-induced proliferation, differentiation, collagen production, and instigated inflammation in cardiac fibroblasts. Moreover, TGF-beta 1-induced NF-kappa B activation including I kappa B alpha phosphorylation and p65 nuclear translocation were also promoted by CGRP8-37 and alpha-CGRP siRNA. NF-kappa B inhibitor pyrroli-dinedithiocarbamate ammonium (PDTC) reversed the effects of CGRP8-37 on NF-kappa B activation. The promotive effects of CGRP8-37 on TGF-b1-induced activation of cardiac fibroblasts were all reversed by PDTC. Monocrotaline (MCT) induces pulmonary arterial hypertension, progressively leading to right ventricular fibrosis. This model of cardiac fibrosis was developed here to test the potentially beneficial effects of TRPA1 activation in vivo. The non-toxic TRPA1 agonist Cinnamaldehyde (CA) inhibited MCT-induced elevation in right ventricle systolic pressure, RV/LV+S, and right ventricular collagen accumulation, as well as down-regulation of CGRP. CA increased the synthesis and secretion of CGRP, and inhibited TGF-beta 1-induced activation in cardiac fibroblasts.Conclusion Our data suggested an autocrine role for cardiac fibroblasts-derived CGRP in suppressing activation of cardiac fibroblasts through inhibiting NF-kappa B activation. Increasing autocrine CGRP by activating TRPA1 can ameliorate cardiac fibrosis. These findings support the notion that CGRP derived from cardiac fibroblasts is an endogenous suppressor of cardiac fibrosis.