Diagnostic Markers for Schistosome-Mediated Liver Disease

<p>Chronic schistosomiasis presents with either a moderate or a severe form, termed intestinal (INT) or hepatosplenic (HS) schistosomiasis, respectively. The Schistosoma mansoni-associated hepatomegaly is estimated in 8.5 million people and ultimately results from liver granulomas induced by trapped parasitic eggs. The CBA/J mouse model replicates these two human disease forms and was used to understand the progressive pathology that leads to HS and to identify potential biomarkers. In this model 20% of infected mice spontaneously develop hypersplenomegaly syndrome (HSS) by 20 weeks of infection while the remaining 80% develop moderate splenomegaly syndrome (MSS). Using this model, we compared the liver protein patterns of control mice and mice infected for 6, 8, 12, or 20 (MSS and HSS) weeks. Two-dimensional differential in gel electrophoresis (2D-DIGE) was used to identify protein pattern variations and protein spots were identified using matrix adsorption laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry. In the first experiment, we found 124 protein spot unique changes for MSS and HSS compared to control mice of which 80 were identified and 35 changes were specific for HSS. In the second experiment, comparison between various time points with control mice revealed 76 significant protein spot changes of which 44 were identified using MALDI-TOF mass spectrometry. Importantly, we found that the abundance of liver keratin D, transferrin isoforms, collagen isoforms, hydroxyproline and Schistosoma mansoni-phosphoenolpyruvate carboxykinase increased while epoxide hydrolase isoforms, peroxiredoxin 6 and major urinary protein (MUP) isoforms decreased significantly with infection. To verify the changes in the liver 2D-DIGE analysis, candidate liver protein markers were measured in mouse serum using targeted biochemical assays. The mouse serum analysis showed MUP levels were decreased, while transferrin, connective tissue growth factor (CTGF), keratin D, hydroxyproline were increased in HSS mice compared to control mice or MSS mice supporting the liver 2D-DIGE analysis. Using targeted assays, serum samples from INT and HS patients were tested for the candidate liver protein markers: keratin D, CTGF, hydroxyproline and transferrin. The human serum analysis showed keratin D levels increased for HS compared to INT and normal sera. The CTGF levels were high in INT compared to HS and normal sera, while transferrin remained unchanged in INT and HS similar to normal sera. Additionally, in severe HS disease, serum hydroxyproline emerged as a strong indicator of fibrosis. We believe that these findings will have direct value in the development of diagnostic tools for early detection of hepatosplenic schistosomiasis in humans.</p>

Diagnostic Markers for Schistosome-Mediated Liver Disease

<p>Chronic schistosomiasis presents with either a moderate or a severe form, termed intestinal (INT) or hepatosplenic (HS) schistosomiasis, respectively. The Schistosoma mansoni-associated hepatomegaly is estimated in 8.5 million people and ultimately results from liver granulomas induced by trapped parasitic eggs. The CBA/J mouse model replicates these two human disease forms and was used to understand the progressive pathology that leads to HS and to identify potential biomarkers. In this model 20% of infected mice spontaneously develop hypersplenomegaly syndrome (HSS) by 20 weeks of infection while the remaining 80% develop moderate splenomegaly syndrome (MSS). Using this model, we compared the liver protein patterns of control mice and mice infected for 6, 8, 12, or 20 (MSS and HSS) weeks. Two-dimensional differential in gel electrophoresis (2D-DIGE) was used to identify protein pattern variations and protein spots were identified using matrix adsorption laser desorption ionisation-time of flight (MALDI-TOF) mass spectrometry. In the first experiment, we found 124 protein spot unique changes for MSS and HSS compared to control mice of which 80 were identified and 35 changes were specific for HSS. In the second experiment, comparison between various time points with control mice revealed 76 significant protein spot changes of which 44 were identified using MALDI-TOF mass spectrometry. Importantly, we found that the abundance of liver keratin D, transferrin isoforms, collagen isoforms, hydroxyproline and Schistosoma mansoni-phosphoenolpyruvate carboxykinase increased while epoxide hydrolase isoforms, peroxiredoxin 6 and major urinary protein (MUP) isoforms decreased significantly with infection. To verify the changes in the liver 2D-DIGE analysis, candidate liver protein markers were measured in mouse serum using targeted biochemical assays. The mouse serum analysis showed MUP levels were decreased, while transferrin, connective tissue growth factor (CTGF), keratin D, hydroxyproline were increased in HSS mice compared to control mice or MSS mice supporting the liver 2D-DIGE analysis. Using targeted assays, serum samples from INT and HS patients were tested for the candidate liver protein markers: keratin D, CTGF, hydroxyproline and transferrin. The human serum analysis showed keratin D levels increased for HS compared to INT and normal sera. The CTGF levels were high in INT compared to HS and normal sera, while transferrin remained unchanged in INT and HS similar to normal sera. Additionally, in severe HS disease, serum hydroxyproline emerged as a strong indicator of fibrosis. We believe that these findings will have direct value in the development of diagnostic tools for early detection of hepatosplenic schistosomiasis in humans.</p>

Cofilin 2 Acts as an Inflammatory Linker Between Chronic Periodontitis and Alzheimer’s Disease in Amyloid Precursor Protein/Presenilin 1 Mice

Increasing evidence has shown a correlation between chronic periodontitis (CP) and Alzheimer’s disease (AD). Nevertheless, there is still a lack of direct evidence, and especially key molecules to connect the two diseases. This study aims to investigate potential protein links between CP and AD within the inflammatory aspect. The hippocampus of CP model mice and controls were collected, and changes in protein expression were evaluated using two-dimensional differential in-gel electrophoresis (2D-DIGE) analysis combined with liquid chromatography tandem mass spectrometry. A total of 15 differentially expressed proteins were identified in CP model mice, as compared with the controls. Among them, S100-A9, transthyretin, Cofilin 2, peroxiredoxin 2, and lipocalin-2 were validated by Western blot according to their dual function both in inflammation and AD. Based on 2D-DIGE analysis, CP animal model had higher levels of S100-A9, Cofilin 2, peroxiredoxin 2, and lipocalin-2 compared to controls. The level of Cofilin 2, one of the well-established proteins in the pathology of AD, was strongly correlated with the time course of CP pathology, indicating a specific molecular correlation between CP and AD. Moreover, the in vivo results showed the level of Cofilin 2 increased significantly along with a prominent increase of the phosphorylation of protein phosphatase 2 (PP2A) and tau protein in the cell lysates of Porphyromonas gingivalis (P.g-LPS)-treated SK-N-SH APPwt cells. Cofilin 2 inhibition resulted in a sharp decrease in PP2A dependent of tau phosphorylation. Furthermore, tumor growth factor (TGF)-β1 was one of the most important inflammatory cytokines for the Pg-LPS-induced Cofilin 2 upregulation in SK-N-SH APPwt cells. These results showed inflammation served as the bond between CP and AD, whereas inflammatory related proteins could be the key linkers between the two diseases. Determining the association between CP and AD at the molecular mechanism will not only hold the direct evidence of the association between the two diseases but also provide a new way of preventing and treating AD: the effective prevention and treatment of CP could serve as a useful method to alleviate the development of AD.

Comparative two-dimensional fluorescence gel electrophoresis

Comparative two-dimensional gel electrophoresis (CoFGE) is a special version of two-dimensional polyacrylamide GE (2D-PAGE) and related to difference GE (2D-DIGE). It provides reproducibility and standardisation for 2D-PAGE by introducing a reference to the experiment. CoFGE uses different fluorescent labels to distinguish analyte and a marker protein mixture. The method allows in silico correction of the assignment of gel-separated proteins based on the co-run references, which form a grid of landmarks across the entire gel. The variability of spot coordinates is reduced to ~1% error and data can thus be compared to results generated independently with the same method. In this way, searchable repositories of gel-separated proteins become feasible. In addition, the CoFGE experimental principle can be used for protein quantification by applying the proteins of the marker grid in different concentrations. Here we present the protocol for conducting a CoFGE experiment, which takes about 2 days to complete for a technician skilled in GE.

Proteomic Exploration of Plasma Exosomes and Other Small Extracellular Vesicles in Pediatric Hodgkin Lymphoma: A Potential Source of Biomarkers for Relapse Occurrence

Exosomes and other small extracellular vesicles (EVs) are potential sources of cancer biomarkers. Plasma-derived EVs have not yet been studied in pediatric Hodgkin lymphoma (HL), for which predictive biomarkers of relapse are greatly needed. In this two-part proteomic study, we used two-dimensional difference gel electrophoresis (2D-DIGE) followed by liquid chromatography–tandem mass spectrometry (LC–MS/MS) to analyze EV proteins of plasma collected at diagnosis from children with nodular sclerosis HL, relapsed or not. EVs isolated using membrane affinity had radii ranging from 20 to 130 nm and contained the programmed cell death 6-interacting (ALIX) and the tumor susceptibility gene 101 (TSG101) proteins, whereas calnexin (CANX) was not detected. 2D-DIGE identified 16 spots as differentially abundant between non-relapsed and relapsed HL (|fold change| ≥ 1.5, p < 0.05). LC–MS/MS identified these spots as 11 unique proteins, including five more abundant in non-relapsed HL (e.g., complement C4b, C4B; fibrinogen γ chain, FGG) and six more abundant in relapsed HL (e.g., transthyretin, TTR). Shotgun LC–MS/MS on pooled EV proteins from non-relapsed HL identified 161 proteins, including 127 already identified in human exosomes (ExoCarta data). This EV cargo included 89 proteins not yet identified in exosomes from healthy plasma. Functional interrogation by the Database for Annotation, Visualization and Integrated Discovery (DAVID) revealed that the EV proteins participate in platelet degranulation and serine-type endopeptidase activity as the most significant Gene Ontology (GO) biological process and molecular function (p < 0.01).

Proteomics Profiling of the Urine of Patients with Hyperthyroidism after Anti-Thyroid Treatment

Hyperthyroidism, which is characterized by increased circulating thyroid hormone levels, alters the body’s metabolic and systemic hemodynamic balance and directly influences renal function. In this study, the urinary proteome of patients with hyperthyroidism was characterized using an untargeted proteomic approach with network analysis. Urine samples were collected from nine age-matched patients before and after carbimazole treatment. Differences in the abundance of urinary proteins between hyperthyroid and euthyroid states were determined using a 2D-DIGE coupled to MALDI-TOF mass spectrometry. Alterations in the abundance of urinary proteins, analyzed via Progenesis software, revealed a statistically significant difference in abundance in a total of 40 spots corresponding to 32 proteins, 25 up and 7 down (≥1.5-fold change, ANOVA, p ≤ 0.05). The proteins identified in the study are known to regulate processes associated with cellular metabolism, transport, and acute phase response. The notable upregulated urinary proteins were serotransferrin, transthyretin, serum albumin, ceruloplasmin, alpha-1B-glycoprotein, syntenin-1, and glutaminyl peptide cyclotransferase, whereas the three notable downregulated proteins were plasma kallikrein, protein glutamine gamma-glutamyl transferase, and serpin B3 (SERPINB3). Bioinformatic analysis using ingenuity pathway analysis (IPA) identified the dysregulation of pathways associated with cellular compromise, inflammatory response, cellular assembly, and organization and identified the involvement of the APP and AKT signaling pathways via their interactions with interleukins as the central nodes.

Proteomics signature of autoimmune atrophic gastritis: towards a link with gastric cancer

Background Autoimmune atrophic gastritis (AAG) is a chronic disease that can progress to gastric cancer (GC). To better understand AAG pathology, this proteomics study investigated gastric proteins whose expression levels are altered in this disease and also in GC. Methods Using two-dimensional difference gel electrophoresis (2D-DIGE), we compared protein maps of gastric corpus biopsies from AAG patients and controls. Differentially abundant spots (|fold change|≥ 1.5, P < 0.01) were selected and identified by LC–MS/MS. The spots were further assessed in gastric antrum biopsies from AAG patients (without and with Helicobacter pylori infection) and from GC patients and unaffected first-degree relatives of GC patients. Results 2D-DIGE identified 67 differentially abundant spots, with 28 more and 39 less abundant in AAG-corpus than controls. LC–MS/MS identified these as 53 distinct proteins. The most significant (adjusted P < 0.01) biological process associated with the less abundant proteins was “tricarboxylic acid cycle”. Of the 67 spots, 57 were similarly differentially abundant in AAG-antrum biopsies irrespective of H. pylori infection status. The differential abundance was also observed in GC biopsies for 14 of 28 more abundant and 35 of 39 less abundant spots, and in normal gastric biopsies of relatives of GC patients for 6 and 25 spots, respectively. Immunoblotting confirmed the different expression levels of two more abundant proteins (PDIA3, GSTP gene products) and four less abundant proteins (ATP5F1A, PGA3, SDHB, PGC). Conclusion This study identified a proteomics signature of AAG. Many differential proteins were shared by GC and may be involved in the progression of AAG to GC.

Bone Marrow-Derived Mesenchymal Stem Cells Differentially Affect Glioblastoma Cell Proliferation, Migration, and Invasion: A 2D-DIGE Proteomic Analysis

Bone marrow-derived mesenchymal stem cells (BM-MSCs) display high tumor tropism and cause indirect effects through the cytokines they secrete. However, the effects of BM-MSCs on the biological behaviors of glioblastoma multiforme remain unclear. In this study, the conditioned medium from BM-MSCs significantly inhibited the proliferation of C6 cells ( P < 0.05 ) but promoted their migration and invasion ( P < 0.05 ). Two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) proteomic analysis revealed 17 proteins differentially expressed in C6 cells exposed to the BM-MSC-conditioned medium including five upregulated proteins and 12 downregulated proteins. Among these, six differentially expressed proteins (Calr, Set, Oat, Npm1, Ddah1, and Tardbp) were closely related to cell proliferation and differentiation, and nine proteins (Pdia6, Sphk1, Anxa4, Vim, Tuba1c, Actr1b, Actn4, Rap2c, and Tpm2) were associated with motility and the cytoskeleton, which may modulate the invasion and migration of tumor cells. Above all, by identifying the differentially expressed proteins using proteomics and bioinformatics analysis, BM-MSCs could be genetically modified to specifically express tumor-suppressive factors when BM-MSCs are to be used as tumor-selective targeting carriers in the future.