Search

Objective: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by thrombofibrotic obstruction of the proximal pulmonary arteries, which result in vascular remodeling of the distal pulmonary artery. While the cellular and molecular mechanisms underlying CTEPH pathogenesis remain incompletely understood, recent evidence implicates vascular remodeling. Here, we identify the molecular mechanisms that contribute to vascular remodeling in CTEPH.Methods: Microarray data (GSE130391) for patients with CTEPH and healthy controls were downloaded from the Gene Expression Omnibus (GEO) and screened for differentially expressed genes (DEGs). DEGs were functionally annotated using Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. A protein–protein interaction (PPI) network was constructed to identify hub genes. Finally, pulmonary artery samples were harvested from patients with CTEPH (n = 10) and from controls (n = 10) and primary vascular smooth muscle cells (VSMCs) were cultured. Effects of the proto-oncogene FOS on VSMC proliferation and migration were assessed using expression and knockdown studies.Results: We detected a total of 292 DEGs, including 151 upregulated and 141 downregulated genes. GO analysis revealed enrichment of DEGs in biological processes of signal transduction, response to lipopolysaccharide, signal transduction, and myeloid dendritic cell differentiation. Molecular function analysis revealed enrichment in tumor necrosis factor (TNF)-activated receptor activity, transcriptional activator activity, and protein homodimerization activity. The expression of TNF-α and its receptor (sTNFR1 and sTNFR2) were significantly higher in CTEPH group, compared with control group. KEGG pathway analysis revealed enrichment in salmonella infection, pathways in cancer, osteoclast differentiation, and cytokine-cytokine receptor interaction. Hub genes in the PPI included FOS, suggesting an important role for this gene in vascular remodeling in CTEPH. Primary VSMCs derived from patients with CTEPH showed increased FOS expression and high proliferation and migration, which was attenuated by FOS inhibition. In control VSMCs, TNF-α treatment increased proliferation and migration, which FOS inhibition likewise attenuated.Conclusion: TNF-α drives CTEPH pathogenesis by promoting VSMC proliferation and migration via increased FOS expression. These results advance our understanding of the molecular mechanisms of vascular remodeling in CTEPH, and may inform the development of new therapeutic targets.

ObjectivesCarotid artery geometry influences blood flow disturbances and is thus an important risk factor for carotid atherosclerosis. Extracellular matrix (ECM) and yes-associated protein (YAP) expression may play essential roles in the pathophysiology of carotid artery stenosis, but the effect of blood flow disturbances of carotid bifurcation location on the ECM is unknown. We hypothesized that carotid artery anatomy and geometry are independently associated with the ECM and YAP expression.MethodsIn this cross-sectional study, 193 patients were divided into two groups: an asymptomatic group (n = 111) and a symptomatic group (n = 82), symptomatic patients presenting with ischemic attack, amaurosis fugax, or minor non-disabling stroke. For all subjects before surgery, carotid bifurcation angle and internal artery angle were measured with computed tomography angiography (CTA), and laminar shear stress was measured with ultrasonography. After surgery, pathology of all plaque specimens was analyzed using hematoxylin and eosin (HE) staining and Movat special staining. Immunohistochemistry was performed to detect expression of YAP in a subset of 30 specimens.ResultsSymptomatic patients had increased carotid bifurcation angle and laminar shear stress compared to asymptomatic patients (P < 0.05), although asymptomatic patients had increased internal carotid angle compared to symptomatic patients (P < 0.001). Relative higher bifurcation angles were correlated with increased carotid bifurcation, decreased internal angle, and decreased laminar shear stress. For each change in intervertebral space or one-third of vertebral body height, carotid bifurcation angle changed 4.76°, internal carotid angle changed 6.91°, and laminar shear stress changed 0.57 dynes/cm2. Pathology showed that average fibrous cap thickness and average narrowest fibrous cap thickness were greater in asymptomatic patients than symptomatic patients (P < 0.05). Expression of proteoglycan and YAP protein in symptomatic patients was higher than in asymptomatic patients (P < 0.001), while collagen expression was lower in symptomatic patients than asymptomatic patients (P < 0.05).ConclusionGeometry of the carotid artery and position relative to cervical spine might be associated with ECM and YAP protein expression, which could contribute to carotid artery stenosis.

ObjectiveVaricose veins are a common problem worldwide and can cause significant impairments in health-related quality of life, but the etiology and pathogenesis remain not well defined. This study aims to elucidate transcriptomic regulations of varicose veins by detecting differentially expressed genes, pathways and regulator genes.MethodsWe harvested great saphenous veins (GSV) from patients who underwent coronary artery bypass grafting (CABG) and varicose veins from conventional stripping surgery. RNA-Sequencing (RNA-Seq) technique was used to obtain the complete transcriptomic data of both GSVs from CABG patients and varicose veins. Weighted Gene Co-expression network analysis (WGCNA) and further analyses were then carried out with the aim to elucidate transcriptomic regulations of varicose veins by detecting differentially expressed genes, pathways and regulator genes.ResultsFrom January 2015 to December 2016, 7 GSVs from CABG patients and 13 varicose veins were obtained. WGCNA identified 4 modules. In the brown module, gene ontology (GO) analysis showed that the biological processes were focused on response to stimulus, immune response and inflammatory response, etc. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis showed that the biological processes were focused on cytokine-cytokine receptor interaction and TNF signaling pathway, etc. In the gray module, GO analysis showed that the biological processes were skeletal myofibril assembly related. The immunohistochemistry staining showed that the expression of ASC, Caspase-1 and NLRP3 were increased in GSVs from CABG patients compared with varicose veins. Histopathological analysis showed that in the varicose veins group, the thickness of vascular wall, tunica intima, tunica media and collagen/smooth muscle ratio were significantly increased, and that the elastic fiber/internal elastic lamina ratio was decreased.ConclusionThis study shows that there are clear differences in transcriptomic information between varicose veins and GSVs from CABG patients. Some inflammatory RNAs are down-regulated in varicose veins compared with GSVs from CABG patients. Skeletal myofibril assembly pathway may play a crucial role in the pathogenesis of varicose veins. Characterization of these RNAs may provide new targets for understanding varicose veins diagnosis, progression, and treatment.