Aherrahrou Rédouane, Baig Ferheen, Theofilatos Konstantinos, Lue Dillon, Beele Alicia, Örd Tiit, Kaikkonen Minna U, Aherrahrou Zouhair, Cheng Qi, Ghosh Saikat, Karnewar Santosh, Karnewar Vaishnavi, Finn Aloke, Owens Gary K, Joner Michael, Mayr Manuel, Civelek Mete
Center for Public Health Genomics, University of Virginia, Charlottesville, Virginia, United States of America.
A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Finland.
medRxiv. 2023 Nov 10:2023.11.10.23298351. doi: 10.1101/2023.11.10.23298351.
Smooth muscle cells (SMCs), which make up the medial layer of arteries, are key cell types involved in cardiovascular diseases (CVD), the leading cause of mortality and morbidity worldwide. In response to microenvironment alterations, SMCs dedifferentiate from a "contractile" to a "synthetic" phenotype characterized by an increased proliferation, migration, production of extracellular matrix (ECM) components, and decreased expression of SMC-specific contractile markers. These phenotypic changes result in vascular remodeling and contribute to the pathogenesis of CVD, including coronary artery disease (CAD), stroke, hypertension, and aortic aneurysms. Here, we aim to identify the genetic variants that regulate ECM secretion in SMCs and predict the causal proteins associated with vascular disease-related loci identified in genome-wide association studies (GWAS).
Using human aortic SMCs from 123 multi-ancestry healthy heart transplant donors, we collected the serum-free media in which the cells were cultured for 24 hours and conducted Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic analysis of the conditioned media.
We measured the abundance of 270 ECM and related proteins. Next, we performed protein quantitative trait locus mapping (pQTL) and identified 20 loci associated with secreted protein abundance in SMCs. We functionally annotated these loci using a colocalization approach. This approach prioritized the genetic variant rs6739323-A at the 2p22.3 locus, which is associated with lower expression of LTBP1 in SMCs and atherosclerosis-prone areas of the aorta, and increased risk for SMC calcification. We found that LTBP1 expression is abundant in SMCs, and its expression at mRNA and protein levels was reduced in unstable and advanced atherosclerotic plaque lesions.
Our results unravel the SMC proteome signature associated with vascular disorders, which may help identify potential therapeutic targets to accelerate the pathway to translation.
构成动脉中层的平滑肌细胞（SMC）是心血管疾病（CVD）的关键细胞类型，而心血管疾病是全球死亡和发病的主要原因。响应微环境变化，SMC从“收缩性”表型去分化为“合成性”表型，其特征为增殖增加、迁移、细胞外基质（ECM）成分产生增加以及SMC特异性收缩标记物表达降低。这些表型变化导致血管重塑，并促成包括冠状动脉疾病（CAD）、中风、高血压和主动脉瘤在内的CVD发病机制。在此，我们旨在鉴定调节SMC中ECM分泌的遗传变异，并预测与全基因组关联研究（GWAS）中确定的血管疾病相关位点相关的因果蛋白。
我们使用来自123名多血统健康心脏移植供体的人主动脉SMC，收集细胞培养24小时的无血清培养基，并对条件培养基进行基于液相色谱 - 串联质谱（LC-MS/MS）的蛋白质组分析。
我们测量了270种ECM和相关蛋白的丰度。接下来，我们进行了蛋白质定量性状位点定位（pQTL），并鉴定了20个与SMC中分泌蛋白丰度相关的位点。我们使用共定位方法对这些位点进行功能注释。该方法确定了2p22.3位点的遗传变异rs6739323-A为优先变异，该变异与SMC和主动脉易发生动脉粥样硬化区域中LTBP1的低表达相关，并增加了SMC钙化风险。我们发现LTBP1在SMC中表达丰富，其在mRNA和蛋白质水平的表达在不稳定和晚期动脉粥样硬化斑块病变中降低。
我们的结果揭示了与血管疾病相关的SMC蛋白质组特征，这可能有助于识别潜在的治疗靶点，以加速转化进程。
