Proteomic Analysis Reveals Differential Expression Profiles in Idiopathic Pulmonary Fibrosis Cell Lines.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, irreversible lung disorder of unknown cause. This disease is characterized by profibrotic activation of resident pulmonary fibroblasts resulting in aberrant deposition of extracellular matrix (ECM) proteins. However, although much is known about the pathophysiology of IPF, the cellular and molecular processes that occur and allow aberrant fibroblast activation remain an unmet need. To explore the differentially expressed proteins (DEPs) associated with aberrant activation of these fibroblasts, we used the IPF lung fibroblast cell lines LL97A (IPF-1) and LL29 (IPF-2), compared to the normal lung fibroblast cell line CCD19Lu (NL-1). Protein samples were quantified and identified using a label-free quantitative proteomic analysis approach by liquid chromatography-tandem mass spectrometry (LC-MS/MS). DEPs were identified after pairwise comparison, including all experimental groups. Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-Protein Interaction (PPI) network construction were used to interpret the proteomic data. Eighty proteins expressed exclusively in the IPF-1 and IPF-2 clusters were identified. In addition, 19 proteins were identified up-regulated in IPF-1 and 10 in IPF-2; 10 proteins were down-regulated in IPF-1 and 2 in IPF-2 when compared to the NL-1 proteome. Using the search tool for retrieval of interacting genes/proteins (STRING) software, a PPI network was constructed between the DEPs and the 80 proteins expressed exclusively in the IPF-2 and IPF-1 clusters, containing 115 nodes and 136 edges. The 10 hub proteins present in the IPP network were identified using the CytoHubba plugin of the Cytoscape software. GO and KEGG pathway analyses showed that the hub proteins were mainly related to cell adhesion, integrin binding, and hematopoietic cell lineage. Our results provide relevant information on DEPs present in IPF lung fibroblast cell lines when compared to the normal lung fibroblast cell line that could play a key role during IPF pathogenesis.

A preliminary study of platelet hyperactivity in the chronic indeterminate phase of Chagas' disease.

The chronic indeterminate phase of Chagas' disease is asymptomatic despite positive test results for antibodies specific to Trypanosoma cruzi. CD62P-APC (P-selectin) and PAC-1 FITC (GpIIb/IIIa) may improve diagnosis as biomarkers of platelet activity. Nine asymptomatic seropositive subjects, previously untreated, were selected from a blood bank within a year of Chagas' disease detection, in addition to a control group of four. All subjects were evaluated by flow cytometry for CD62P, PAC-1 and CD41, and in a complementary study, by Tissue Doppler Echocardiography for isovolumic relaxation times (IVRT) and E/A ratios. The subjects were classified as positive or negative for CD62P and PAC-1 by a cut off obtained from their mean±2SD. For IVRT and E/A ratios, cut offs were obtained from the American Society of Echocardiography and the European Association of Cardiovascular Imaging recommendations. Fisher's exact test was used for associated findings. Pre-test and post-test probability, sensitivity, specificity, positive and negative predictive values and likelihood ratios were calculated. Abnormalities were expressed as platelet hyperactivity and ventricular dysfunction in CD62P, PAC-1, IVRT and E/A ratios. CD62P appears to have greater sensitivity (0.75) and PAC-1, more accurate specificity (0.75), which may explain thrombotic events in Chagas' disease. We recommend the use of CD62P and PAC-1 as biomarkers of platelet hyperactivity in patients in the chronic indeterminate phase of Chagas' disease.