Aggrecan accumulates at sites of increased pulmonary arterial pressure in idiopathic pulmonary arterial hypertension

Abstract

Expansion of extracellular matrix occurs in all stages of pulmonary angiopathy associated with pulmonary arterial hypertension (PAH). In systemic arteries, dysregulation and accumulation of the large chondroitin‐sulfate proteoglycan aggrecan is associated with swelling and disruption of vessel wall homeostasis. Whether aggrecan is present in pulmonary arteries, and its potential roles in PAH, has not been thoroughly investigated. Here, lung tissue from 11 patients with idiopathic PAH was imaged using synchrotron radiation phase‐contrast microcomputed tomography (TOMCAT beamline, Swiss Light Source). Immunohistochemistry for aggrecan core protein in subsequently sectioned lung tissue demonstrated accumulation in PAH compared with failed donor lung controls. RNAscope in situ hybridization indicated ACAN expression in vascular endothelium and smooth muscle cells. Based on qualitative histological analysis, aggrecan localizes to cellular, rather than fibrotic or collagenous, lesions. Interestingly, ADAMTS15 , a potential aggrecanase, was upregulated in pulmonary arteries in PAH. Aligning traditional histological analysis with three‐dimensional renderings of pulmonary arteries from synchrotron imaging identified aggrecan in lumen‐reducing lesions containing loose, cell‐rich connective tissue, at sites of intrapulmonary bronchopulmonary shunting, and at sites of presumed elevated pulmonary blood pressure. Our findings suggest that ACAN expression may be an early response to injury in pulmonary angiopathy and supports recent work showing that dysregulation of aggrecan turnover is a hallmark of arterial adaptations to altered hemodynamics. Whether cause or effect, aggrecan and aggrecanase regulation in PAH are potential therapeutic targets.

Identification of key genes and signaling pathway in the pathogenesis of Huntington's disease via bioinformatics and next generation sequencing data analysis

“…Signaling pathways include signaling by GPCR [56] and extracellular matrix organization [57] were responsible for advancement of HD. Research has shown that CBLN2 [58], MOG (myelin oligodendrocyte glycoprotein) [59], ROS1 [60], LGR6 [61], GJA5 [62], SUCNR1 [63], REN (renin) [64], VEGFC (vascular endothelial growth factor C) [65], TLR2 [66], FGF12 [67], WT1 [68], SLC22A3 [69], CSRP3 [70], PAPPA2 [71], ACAN (aggrecan) [72], SHH (sonic hedgehog signaling molecule) [73], PDC (phosducin) [74], AGTR1 [75], XDH (xanthine dehydrogenase) [76], P2RX7 [77], NTSR1 [78], SIRT2 [79], RBP4 [80], BMP2 [81], ERBB3 [82], HAS2 [83], CDH13 [84], CSMD1 [85], NR3C2 [86], EPAS1 [87], TRPC6 [88], MMP3 [89], ERAP2 [90], HLA-DRB1 [91], CD74 [92], VWF (von Willebrand factor) [93], MTTP (microsomal triglyceride transfer protein) [494], ANGPT2 [184], AKR1C3 [495], NEDD4L [496], CASP1 [497], LDB2 [498], CHRNA5 [499], CCND2 [500], BRCA2 [97], ZBTB20 [501], EFNB2 [502], CYP7B1 [503], DCLK1 [504], RBM20 [505], PLCE1 [197], protein) [94], NEDD4L [95], CASP1 [96], BRCA2 [97], EFNB2 [98], PLCE1 [99], EGFR (epidermal growth factor receptor) [100], ABCA1 [101], CRHR2 [102], RND3 [103], COMT (catechol-O-methyltransferase) [104] and SMAD9 [105] plays an important role in the pathogenesis of hypertension. Studies have revealed that NEUROD4 [106], SOX10 [107], MOG (myelin oligodendrocyte glycoprotein) [108], NR5A2 [109], GLRA3 [110], FA2H [111], SERPINA […”