ITRAQ-Based Proteomics Reveals Novel Biomarkers for Idiopathic Pulmonary Fibrosis.
ABSTRACT: Idiopathic pulmonary fibrosis (IPF) is a gradual lung disease with a survival of less than 5 years post-diagnosis for most patients. Poor molecular description of IPF has led to unsatisfactory interpretation of the pathogenesis of this disease, resulting in the lack of successful treatments. The objective of this study was to discover novel noninvasive biomarkers for the diagnosis of IPF. We employed a coupled isobaric tag for relative and absolute quantitation (iTRAQ)-liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach to examine protein expression in patients with IPF. A total of 97 differentially expressed proteins (38 upregulated proteins and 59 downregulated proteins) were identified in the serum of IPF patients. Using String software, a regulatory network containing 87 nodes and 244 edges was built, and the functional enrichment showed that differentially expressed proteins were predominantly involved in protein activation cascade, regulation of response to wounding and extracellular components. A set of three most significantly upregulated proteins (HBB, CRP and SERPINA1) and four most significantly downregulated proteins (APOA2, AHSG, KNG1 and AMBP) were selected for validation in an independent cohort of IPF and other lung diseases using ELISA test. The results confirmed the iTRAQ profiling results and AHSG, AMBP, CRP and KNG1 were found as specific IPF biomarkers. ROC analysis indicated the diagnosis potential of the validated biomarkers. The findings of this study will contribute in understanding the pathogenesis of IPF and facilitate the development of therapeutic targets.
Project description:Yin-deficiency-heat (YDH) syndrome is a concept in Traditional Chinese Medicine (TCM) for describing subhealth status. However, there are few efficient diagnostic methods available for confirming YDH syndrome. To explore the novel method for diagnosing YDH syndrome, we applied iTRAQ to observe the serum protein profiles in YDH syndrome rats and confirmed protein levels by ELISA. A total of 92 differentially expressed proteins (63 upregulated proteins and 29 downregulated proteins), which were mainly involved in complement and coagulation cascades and glucose metabolism pathway, were identified by the proteomic experiments. Kininogen 1 (KNG1) was significantly increased (p < 0.0001), while apolipoprotein C-III (APOC3, p < 0.005) and paraoxonase 1 (PON1, p < 0.001) were significantly decreased in the serum of YDH syndrome rats. The combination of KNG1, APOC3, and PON1 constituted a diagnostic model with 100.0% sensitivity and 85.0% specificity. The results indicated that KNG1, APOC3, and PON1 may act as potential biomarkers for diagnosing YDH syndrome. KNG1 may regulate cytokines and chemokines release in YDH syndrome, and the low levels of PON1 and APOC3 may increase oxidative stress and lipolysis in YDH syndrome, respectively. Our work provides a novel method for YDH syndrome diagnosis and also provides valuable experimental basis to understand the molecular mechanism of YDH syndrome.
Project description:Background:Hepatocellular carcinoma (HCC) is a malignant tumor associated with a poor prognosis. Serum biomarkers of HCC have the potential to improve the diagnosis, provide a means to monitor the tumors, and predict their malignancy. Proteins that are expressed differentially between HCC patients and normal controls have the potential to be biomarkers. Method:Serum samples from 10 confirmed HCC patients and 10 controls were collected. The differentially expressed proteins in the serum were identified using an isobaric tags for relative and absolute quantitation- (iTRAQ-) based method. Potential serum biomarkers were validated by ELISA in another 20 HCC patients and 20 controls. Their expression data in HCC were extracted from The Cancer Genome Atlas (TCGA) dataset. Results:A total of 260 proteins were measured in the serum of HCC patients and compared to those in sex- and age-matched normal controls. Forty-one proteins displayed significant changes, with 26 being downregulated and 15 being upregulated. Upregulated proteins included alpha-1-antitrypsin (A1AT) and peroxiredoxin 2 (PRDX2), and downregulated proteins included paraoxonase 1 (PON1) and C-reactive protein (CRP). We then used ELISA to measure serum levels of A1AT, PRDX2, PON1, and CRP in another 20 patients with HCC and found that only PON1 levels were consistent with the iTRAQ result. In TCGA dataset, PON1 expression was downregulated in HCC tissues (P < 0.001) and low expression of PON1 was associated with poor survival in HCC patients (P < 0.001) and low expression of PON1 was associated with poor survival in HCC patients (. Conclusions:PON1 could act as a biomarker for HCC to assist in the diagnosis of HCC.
Project description:BACKGROUND Spinal cord injury (SCI) is a devastating trauma of the central nervous system (CNS), with high levels of morbidity, disability, and mortality. One week after SCI may be a critical time for treatment. Changes in protein expression have crucial functions in nervous system diseases, although the effects of changes occurring 1 week after SCI on patient outcomes are unclear. MATERIAL AND METHODS Protein expression was examined in a rat contusive SCI model 1 week after SCI. Differentially expressed proteins (DEPs) were identified by isobaric tagging for relative and absolute protein quantification (iTRAQ)-coupled liquid chromatography tandem-mass spectrometry (LC-MS/MS) proteomics analysis. Gene Ontology (GO) analysis was performed to identify the biological processes, molecular functions, and cellular component terms of the identified DEPs, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) was used to identify key enriched pathways. Protein-protein interaction (PPI) networks were analyzed to identify the top 10 high-degree core proteins. RESULTS Of the 295 DEPs identified, 204 (69.15%) were upregulated and 91 (30.85%) were downregulated 1 week after injury. The main cellular components, molecular functions, biological processes, and pathways identified may be crucial mechanisms involved in SCI. The top 10 high-degree core proteins were complement component C3 (C3), alpha-2-HS-glycoprotein (Ahsg), T-kininogen 1 (Kng1), Serpinc1 protein (Serpinc1), apolipoprotein A-I (Apoa1), serum albumin (Alb), disulfide-isomerase protein (P4hb), transport protein Sec61 subunit alpha isoform 1 (Sec61a1), serotransferrin (Tf), and 60S ribosomal protein L15 (Rpl15). CONCLUSIONS The proteins identified in this study may provide potential targets for diagnosis and treatment 1 week after SCI.
Project description:The purpose of this study was to evaluate the utility of potential serum biomarkers for acute aortic dissection (AAD) that were identified by isobaric Tags for Relative and Absolute Quantitation (iTRAQ) approaches. Serum samples from 20 AAD patients and 20 healthy volunteers were analyzed using iTRAQ technology. Protein validation was performed using samples from 120 patients with chest pain. A total of 355 proteins were identified with the iTRAQ approach; 164 proteins reached the strict quantitative standard, and 125 proteins were increased or decreased more than 1.2-fold (64 and 61 proteins were up- and downregulated, resp.). Lumican, C-reactive protein (CRP), thrombospondin-1 (TSP-1), and D-dimer were selected as candidate biomarkers for the validation tests. Receiver operating characteristic (ROC) curves show that Lumican and D-dimer have diagnostic value (area under the curves [AUCs] 0.895 and 0.891, P < 0.05). For Lumican, the diagnostic sensitivity and specificity were 73.33% and 98.33%, while the corresponding values for D-dimer were 93.33% and 68.33%. For Lumican and D-dimer AAD combined diagnosis, the sensitivity and specificity were 88.33% and 95%, respectively. In conclusion, Lumican has good specificity and D-dimer has good sensitivity for the diagnosis of AAD, while the combined detection of D-dimer and Lumican has better diagnostic value.
Project description:Systematic profiling of a larger portion of circulating plasma proteome provide opportunities for unbiased discovery of novel markers to improve diagnostic, therapeutic, or predictive accuracy. This study aimed to identify differentially expressed proteins (DEPs) in plasma that could provide overall insight into the molecular changes of both H- type hypertension (HH) and HH-related acute ischemic stroke (AIS). This study used an iTRAQ-based LC-MS/MS proteomics approach to screen for plasma DEPs in HH patients with and without AIS, and controls. After excluding highly abundant plasma proteins, more than 600 proteins, and their relative levels, were identified. Of these, 26 DEPs, each showing > 1.2-fold change, were identified in HH and HH-related AIS patients compared with controls. Bioinformatics analysis revealed that these DEPs were enriched in 21 functional gene ontology items; "blood coagulation" was the most predominant pathway showing enrichment. Of these, eight DEPs were located in the hub position of networks involved with protein-protein interactions. AT-3, CRP, ApoB, and AHSG were further validated in each group by enzyme-linked immune sorbent assays. Comparing HH-related AIS with HH, the areas under the curve for AT-3, CRP, ApoB, and AHSG were 0.698, 0.892, 0.626, and 0.847, respectively. This proteomic profiling study provided enhanced pathophysiological understanding of the regulatory processes involved in coagulation, inflammation, and metabolism, and identified a panel of novel biomarkers for detecting HH-related AIS during its pre-stroke stage.
Project description:The epidemic of pulmonary tuberculosis (TB), especially multidrug-resistance tuberculosis (MDR-TB) presented a major challenge for TB treatment today. We performed iTRAQ labeling coupled with two-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS) and Solexa sequencing among MDR-TB patients, drug-sensitive tuberculosis (DS-TB) patients, and healthy controls. A total of 50 differentially expressed proteins and 43 differentially expressed miRNAs (fold change >1.50 or <0.60, P<0.05) were identified in the MDR-TB patients compared to both DS-TB patients and healthy controls. We found that 22.00% of differentially expressed proteins and 32.56% of differentially expressed miRNAs were related, and could construct a network mainly in complement and coagulation cascades. Significant differences in CD44 antigen (CD44), coagulation factor XI (F11), kininogen-1 (KNG1), miR-4433b-5p, miR-424-5p, and miR-199b-5p were found among MDR-TB patients, DS-TB patients and healthy controls (P<0.05) by enzyme-linked immunosorbent assay (ELISA) and SYBR green qRT-PCR validation. A strong negative correlation, consistent with the target gene prediction, was found between miR-199b-5p and KNG1 (r=-0.232, P=0.017). Moreover, we established the MDR-TB diagnostic model based on five biomarkers (CD44, KNG1, miR-4433b-5p, miR-424-5p, and miR-199b-5p). Our study proposes potential biomarkers for MDR-TB diagnosis, and also provides a new experimental basis to understand the pathogenesis of MDR-TB.
Project description:Background:Idiopathic pulmonary fibrosis (IPF) is a progressive, eventually fatal disease. IPF is characterized by excessive accumulation of the extracellular matrix (ECM) in the alveolar parenchyma and progressive lung scarring. The pathogenesis of IPF and whether the ECM involved in the process remain unknown. Methods:To identify potential treatment target and ECM associated proteins that may be involved in the development of IPF, we employed isobaric tag for relative and absolute quantitation (iTRAQ) combined liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach to examine protein expression in lung tissues from IPF patients. Results:A total of 662 proteins with altered expression (455 upregulated proteins and 207 downregulated proteins) were identified in lung tissue of IPF patients compared with control. KEGG pathway enrichment analysis showed that the altered proteins in lung tissue mainly belonged to the PI3K-Akt signaling, focal adhesion, ECM-receptor interaction, and carbon metabolism pathways. According to the bioinformatic definition of the matrisome, 229 matrisome proteins were identified in lung tissue. These proteins comprised the ECM of lung, of which 104 were core matrisome proteins, and 125 were matrisome-associated proteins. Of the 229 ECM quantified proteins, 56 significantly differentially expressed proteins (19 upregulated proteins and 37 downregulated proteins) were detected in IPF lung tissue samples. In addition to proteins with well-known functions such as COL1A1, SCGB1A1, TAGLN, PSEN2, TSPAN1, CTSB, AGR2, CSPG2, and SERPINB3, we identified several novel ECM proteins with unknown function deposited in IPF lung tissue including LGALS7, ASPN, HSP90AA1 and HSP90AB1. Some of these differentially expressed proteins were further verified using Western blot analysis and immunohistochemical staining. Conclusions:This study provides a list of proteomes that were detected in IPF lung tissue by iTRAQ technology combined with LC-MS/MS. The findings of this study will contribute better understanding to the pathogenesis of IPF and facilitate the development of therapeutic targets.
Project description:Obesity is a chronic disease that negatively affects life expectancy through its association with life-threatening diseases such as cancer and cardiovascular diseases. Expression proteomics combined with in silico interaction studies are used to uncover potential biomarkers and the pathways that promote obesity-related complications. These biomarkers can either aid in the development of personalized therapies or identify individuals at risk of developing obesity-related diseases. To determine the serum protein changes, Wistar rats were fed standard chow (low fat, LF), or chow formulated high fat (HF) diets (HF1, HF2 and HF3) for 8 and 42 weeks to induce obesity. Serum samples were collected from lean and obese rats at these time points. The serum samples were precipitated using trichloroacetic acid (TCA)/acetone and analyzed by 2-Dimensional SDS-PAGE. Serum protein profiles were examined using mass spectrometry (MS)-based proteomics and validated by western blotting. Protein-protein interactions among the selected proteins were studied in silico using bioinformatics tools. Several proteins showed differences in expression among the three HF diets when compared to the LF diet, and only proteins with???twofold expression levels were considered differentially expressed. Apolipoprotein-AIV (APOA4), C-reactive protein (CRP), and alpha 2-HS glycoprotein (AHSG) showed differential expression at both 8 and 42 weeks, whereas alpha 1 macroglobulin (AMBP) was differentially expressed only at 8 weeks. Network analysis revealed some interactions among the proteins, an indication that these proteins might interactively play a crucial role in development of obesity-induced diseases. These data show the variation in the expression of serum proteins during acute and chronic exposure to high fat diet. Based on the expression and the in-silico interaction these proteins warrant further investigation for their role in obesity development.
Project description:Systems biology and bioinformatics provide the feasibility for the basic research associated with "same traditional Chinese medicine (TCM) syndrome in different diseases". In this study, the plasma proteins in postoperative colorectal (PCC) and postoperative liver cancer (PLC) patients with YDLKS (Yin deficiency of liver-kidney syndrome) were screened out using iTRAQ combined with LC-MS/MS technology. The results demonstrated that, KNG1, AMBP, SERPING1, etc, were all differentially expressed in both PCC and PLC patients with YDLKS, and associated closely with complement and coagulation cascades pathway. C7 and C2 were another two representative factors involving in former pathway. Further validation showed that, the C7 levels were increased significantly in PLC (P < 0.05) and PCC (P < 0.05) with YDLKS group compared to those of NS (no obvious TCM syndromes) group. The AMBP levels were down-regulated significantly in PLC with YDLKS group compared to those of PCC with YDLKS group (P < 0.05). The significant differences of SERPING1 levels (and C2 levels) were shown between YDLKS and NS in PCC (P < 0.01). There were also significant differences of C2 levels between PCC and PLC patients with YDLKS (P < 0.05). Moreover, significant differences of C2 levels were also found between PLC and PCC patients with YDLKS (P < 0.01). ROC curves indicated that, C7 and SERPING1 independently had a potential diagnostic value in distinguishing YDLKS from NS in PLC and PCC, providing the evidences for the material basis of "same TCM syndrome in different diseases" in PCC and PLC patients with YDLKS.
Project description:Among malignant tumors, the mortality rate of esophageal squamous cell carcinoma (ESCC) ranks sixth in the world. Late-stage diagnosis of ESCC increases the mortality. Therefore, more effective biomarkers for early diagnosis of ESCC are necessary. Unfortunately, appropriate biomarkers for clinical diagnosis and prognosis have not been identified yet. However, recent progresses in quantitative proteomics have offered opportunities to identify plasma proteins as biomarkers for ESCC. In the present study, plasma samples were analyzed by differential in-gel electrophoresis (DIGE) and differentially expressed proteins were identified by matrix assisted laser desorption ionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF MS). A total of 31 proteins representing 12 unique gene products were identified, in which 16 proteins were up-regulated and 15 down-regulated in tumors. The up-regulated proteins were alpha-2-HS-glycoprotein (AHSG), leucine-rich alpha-2-glycoprotein (LRG), zinc-alpha-2-glycoprotein, alpha-1-antichymotrypsin, complement factor I and complement C4-B, whereas the down-regulated proteins were serum albumin, Ig alpha-2 chain C region, alpha-1-antitrypsin, fibrinogen gamma chain, haptoglobin and hemoglobin subunit alpha. Among all the differentially expressed proteins, AHSG and LRG were validated by ELISA. The results were consistent with the data from the proteomics results, further suggesting that AHSG and LRG may be employed as potential biomarkers for the early diagnosis of ESCC. In summary, this study was the first time to use DIGE combined MALDI-TOF/TOF platform to identify the potential plasma biomarkers for ESCC. The plasma AHSG and LRG showed great potential for ESCC screening.