Weighted Gene Co-expression Network Analysis of Key Biomarkers Associated With Bronchopulmonary Dysplasia
FRONTIERS IN GENETICS
Authors: Cai, Yao; Ma, Fei; Qu, LiuHong; Liu, Binqing; Xiong, Hui; Ma, Yanmei; Li, Sitao; Hao, Hu
Abstract
Bronchopulmonary dysplasia (BPD) is a complex disorder resulting from interactions between genes and the environment. The accurate molecular etiology of BPD remains largely unclear. This study aimed to identify key BPD-associated genes and pathways functionally enriched using weighted gene co-expression network analysis (WGCNA). We analyzed microarray data of 62 pre-term patients with BPD and 38 pre-term patients without BPD from Gene Expression Omnibus (GEO). WGCNA was used to construct a gene expression network, and genes were classified into definite modules. In addition, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of BPD-related hub genes were performed. Firstly, we constructed a weighted gene co-expression network, and genes were divided into 10 modules. Among the modules, the yellow module was related to BPD progression and severity and included the following hub genes:MMP25,MMP9,SIRPA,CKAP4,SLCO4C1, andSLC2A3; and the red module included some co-expression molecules that displayed a continuous decline in expression with BPD progression and included the following hub genes:LEF1,ITK,CD6,RASGRP1,IL7R,SKAP1,CD3E, andICOS. GO and KEGG analyses showed that high expression of inflammatory response-related genes and low expression of T cell receptor activation-related genes are significantly correlated with BPD progression. The present WGCNA-based study thus provides an overall perspective of BPD and lays the foundation for identifying potential pathways and hub genes that contribute to the development of BPD.
Matrix metalloproteinase 14 and 19 expression is associated with thoracic aortic aneurysms
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
Authors: Jackson, Veronica; Olsson, Therese; Kurtovic, Sanela; Folkersen, Lasse; Paloschi, Valentina; Wagsater, Dick; Franco-Cereceda, Anders; Eriksson, Per
Abstract
Objective: It is hypothesized that an altered turnover of extracellular matrix mediated by matrix metalloproteinases (MMPs) is present in thoracic aortic aneurysms. Here, we analyzed the occurrence of MMPs and MMP inhibitors in ascending aortic aneurysms in patients with bicuspid and tricuspid aortic valves. Methods: Expression of 23 MMPs and their inhibitors was measured in aortic intima/media and adventitia in 109 patients (40 tricuspid, 69 bicuspid, 68 with aortic diameter >= 4.5 cm, and 41 with <= 4.0 cm) using Affymetrix Exon arrays (Affymetrix, Santa Clara, Calif). Gene expression was confirmed by quantitative real-time polymerase chain reaction. Principal components analysis was used to study differences in gene expression. Immunohistochemistry was used to study protein expression. Results: We detected messenger RNA expression for gelatinases (MMP2 and MMP9), stromelysin 3 (MMP11), all membrane bound MMPs (MMP14, MMP15, MMP16, MMP17, MMP24, MMP25), MMP19, MMP21, and MMP28 in ascending aorta. No expression of collagenases was detected. Principal components analysis showed that changes in mRNA expression between dilated and nondilated aorta were mainly detected in patients with tricuspid aortic valves. MMP14 and MMP19 showed higher expression in dilated aortas and MMP19 expression correlated positively to maximal aortic diameter in patients with tricuspid aortic valves (Rho = 0.61, P = .004, and Rho = 0.57, P = .008, using raw and body surface area-corrected aortic diameter, respectively). Immunohistochemical staining demonstrated increased medial expression of MMP14 and MMP19 in dilated aorta. Conclusions: The present study identifies MMP14 and MMP19 as proteolytic enzymes potentially involved in aneurysm formation in the ascending aorta of patients with tricuspid aortic valves. (J Thorac Cardiovasc Surg 2012;144:459-66)