ITIH4 (inter-alpha-trypsin inhibitor heavy chain 4) is a new acute-phase protein isolated from cattle during experimental infection

Liver microbial community and associated host transcriptome in calves with feed induced acidosis

Introduction

In the dairy industry, calves are typically fed diets rich in highly fermentable carbohydrates and low in fibrous feeds to maximize ruminal papillae and tissue development. Calves on such diets are vulnerable at developing ruminal acidosis. Prevalent in cattle, liver abscess (LA) is considered a sequela to ruminal acidosis. LAs can cause significant liver function condemnation and decreased growth and production. Currently, we know little about the liver microbiome in calves with feed-induced acidosis.

Methods

Using our established model of ruminal acidosis, where young calves were fed an acidosis-inducing (AC) or -blunting (control) diet starting at birth until 17-week of age, we investigated microbial community changes in the liver resultant from ruminal acidosis. Eight calves were randomly assigned to each diet, with four animals per treatment. Rumen epithelium and liver tissues were collected at 17 weeks of age right after euthanasia. Total RNAs were extracted and followed by whole transcriptome sequencing. Microbial RNA reads were enriched bioinformatically and used for microbial taxonomy classification using Kraken2.

Results

AC Calves showed significantly less weight gain over the course of the experiment, in addition to significantly lower ruminal pH, and rumen degradation comparison to the control group (p < 0.05). In the liver, a total of 29 genera showed a significant (p < 0.05) abundance change (> 2-fold) between the treatments at 17-week of age. Among these, Fibrobacter, Treponema, Lactobacillus, and Olsenella have been reported in abscessed liver in cattle. Concurrent abundance changes in 9 of the genera were observed in both the liver and rumen tissues collected at 17-week of age, indicating potential crosstalk between the liver and rumen epithelial microbial communities. Significant association was identified between host liver gene and its embedded microbial taxa. Aside from identifying previously reported microbial taxa in cattle abscessed liver, new repertoire of actively transcribed microbial taxa was identified in this study.

Discussion

By employing metatranscriptome sequencing, our study painted a picture of liver microbiome in young calves with or without feed induced acidosis. Our study suggested that liver microbiome may have a critical impact on host liver physiology. Novel findings of this study emphasize the need for further in-depth analysis to uncover the functional roles of liver resident microbiome in liver metabolic acidosis resultant from feed-related ruminal acidosis.

Acute phase proteins in cattle and swine: A review

The major acute phase proteins (APPs) in cattle are haptoglobin (Hp) and serum amyloid A (SAA), and in swine, are Hp, SAA, C-reactive protein (CRP), and Pig major acute phase protein (Pig-MAP). Many methodologic assays are presently available to measure these parameters, which are still being improved to increase their specificity, sensitivity, user-friendliness, and economic availability. In cattle, the main applications are the diagnosis and monitoring of frequent diseases such as mastitis and metritis in dairy cows and respiratory problems in young calves. In pigs, APPs are useful in the control of bacterial and viral infections, and they may be used at the slaughterhouse to monitor subclinical pathologies and improve food safety. The utility of APP in animal production must not be forgotten; optimization of protocols to improve performance, welfare, and nutrition may benefit from the use of APPs. Other sample types besides serum or plasma have potential uses; APP determination in milk is a powerful tool in the control of mastitis, saliva is a non-invasive sample type, and meat juice is easily obtained at the slaughterhouse. Increasing our knowledge of reference intervals and the influence of variables such as age, breed, sex, and the season is important. Finally, worldwide harmonization and standardization of analytical procedures will help to expand the use of APPs.

Validation of new automated turbidimetric immunoassays for the measurement of haptoglobin and inter-α-trypsin inhibitor heavy chain H4 specific for the bovine species

BACKGROUND

Good strategical programs are required for the early detection of disease even in the absence of evident clinical signs, which is crucial in satisfying animal welfare. Haptoglobin (Hp) and inter-α-trypsin inhibitor heavy chain H4 (ITIH4) are acute phase proteins and good biomarkers of early inflammation in cattle, with plasma levels that significantly increase after injury or infection.

OBJECTIVES

We aimed to develop and validate two new immunoturbidimetric methods for Hp and ITIH4.

METHODS

Species-specific antibodies were obtained and used to develop the immunoassays. For the Hp assay, antibodies were fixed to latex microparticles to enhance detection. The immunoassays were set up in an automated analyzer to carry out validation studies. Reference intervals were calculated using Reference Value Advisor.

RESULTS

The Hp immunoturbidimetric method had a linear analytical range up to 0.40 mg/mL. The limit of detection (LoD) was 0.005 mg/mL, and the limit of quantification (LoQ) was 0.007 mg/mL. Total imprecision was less than 7%. Comparison with ELISA and single radial immunodiffusion (SRID) showed good correlation, whereas the comparison with the colorimetric method showed constant and proportional differences. The ITIH4 immunoassay showed linearity up to 5 mg/mL, and the LoD was 0.002 mg/mL. Total imprecision was less than 6%. Method comparison showed a good correlation with single radial immunodiffusion, both methods being equivalent. Bilirubin, triglycerides, and hemoglobin presented no interference in any of the assays. Reference intervals were 0.007-0.017 mg/mL for Hp and 0.2-0.7 mg/mL for ITIH4 in dairy cows 10 days before parturition.

CONCLUSIONS

Immunoturbidimetric methods developed for Hp and ITIH4 can measure basal and increased levels of these proteins, showing adequate precision, accuracy, and robustness.

Inter-α-inhibitor heavy chain H4 and sepsis-related coagulation disturbances: Another link between innate immunity and coagulation

Background

The protease inhibitor inter-α-inhibitor heavy chain H4 (ITIH4) has been described as an acute-phase reactant and could potentially aid in sepsis monitoring and prognostication.

Objectives

To investigate ITIH4 plasma levels in sepsis patients compared with healthy controls and to examine the association between ITIH4 and acute-phase response markers, blood coagulation, and organ dysfunction in sepsis.

Methods

We performed a post hoc study to a prospective cohort study. Patients with septic shock (n = 39) were enrolled upon intensive care unit admission. ITIH4 was analyzed using an in-house immunoassay. Standard coagulation parameters, thrombin generation, fibrin formation and lysis, C-reactive protein, organ dysfunction markers, Sequential Organ Failure Assessment score, and disseminated intravascular coagulation (DIC) score were registered. ITIH4 levels were also investigated in a murine Escherichia coli sepsis model.

Results

ITIH4 did not display acute-phase behavior as mean ITIH4 levels were not increased in patients with septic shock or in E. coli-infected mice. However, ITIH4 exhibited large interindividual variation in patients with septic shock compared with healthy controls. Low ITIH4 was associated with sepsis-related coagulopathy, including a high DIC score (mean ITIH4: DIC, 203 μg/mL vs non-DIC, 267 μg/mL, P = .01), low antithrombin (r = 0.70, P < .0001) and decreased thrombin generation (mean ITIH4: first peak thrombin tertile, 210 μg/mL vs third peak thrombin tertile, 303 μg/mL, P = .01). ITIH4 showed moderate correlation with arterial blood lactate (ρ = -0.50, P < .001) but only weak correlations with C-reactive protein, alanine transaminase, bilirubin, and Sequential Organ Failure Assessment score (all, ρ < 0.26, P > .05).

Conclusion

ITIH4 is associated with sepsis-related coagulopathy but is not an acute-phase reactant during septic shock.

Changes in the Profile of Fecal Microbiota and Metabolites as Well as Serum Metabolites and Proteome After Dietary Inulin Supplementation in Dairy Cows With Subclinical Mastitis

The occurrence and development of mastitis is linked to dysbiostic gastrointestinal microbiota. Inulin is a dietary prebiotic that improves the profile of intestinal flora. Our previous study showed that inulin supplementation could improve the ruminal microbes of subclinical mastitis (SCM) cows. The current study attempted to further investigate the response of hindgut (fecal) microbiome and metabolites, serum metabolism, and protein expression to inulin in the in SCM cows. Different levels of inulin (0, 100, 200, 300, and 400 g/day per cow) were supplemented in SCM cows. Compared with control group, Bacteroides and Bifidobacteria were increased, and Paeniclostridium, Ruminococcaceae, Coprococcus, and Clostridia were decreased in the feces of inulin groups, and accompanied with elevated propionate and butyrate concentrations, while secondary bile acid (SBA) metabolites were increased and proinflammatory lipid oxidation products were dropped in both feces and serum. In serum, inulin intake suppressed the levels of triglyceride (TG) and low-density lipoprotein (LDL). Serum proteome analysis found that CD44 antigen, phosphatidylinositol-glycan-specific phospholipase D, apolipoprotein A-II, and superoxide dismutase [Cu-Zn] were upregulated, while cathelicidin-1, haptoglobin, serpin A3, inter-alpha-trypsin inhibitor heavy chain H4 were downregulated in inulin groups. These findings suggested further evidence for inulin supplementation in amelioration of inflammatory symptoms in SCM cows, which might provide alternative treatment for mastitis.

Application of Proteogenomics to Urine Analysis towards the Identification of Novel Biomarkers of Prostate Cancer: An Exploratory Study

Simple Summary

Prostate cancer (PCa) is one of the most common cancers. Due to the limited and invasive approaches for PCa diagnosis, it is crucial to identify more accurate and non-invasive biomarkers for its detection. The aim of our study was to non-invasively uncover new protein targets for detecting PCa using a proteomics and proteogenomics approach. This work identified several dysregulated mutant protein isoforms in urine from PCa patients, some of them predicted to have a protective or an adverse role in these patients. These results are promising given urine’s non-invasive nature and offers an auspicious opportunity for research and development of PCa biomarkers.

Abstract

To identify new protein targets for PCa detection, first, a shotgun discovery experiment was performed to characterize the urinary proteome of PCa patients. This revealed 18 differentially abundant urinary proteins in PCa patients. Second, selected targets were clinically tested by immunoblot, and the soluble E-cadherin fragment was detected for the first time in the urine of PCa patients. Third, the proteogenome landscape of these PCa patients was characterized, revealing 1665 mutant protein isoforms. Statistical analysis revealed 6 differentially abundant mutant protein isoforms in PCa patients. Analysis of the likely effects of mutations on protein function and PPIs involving the dysregulated mutant protein isoforms suggests a protective role of mutations HSPG2*Q1062H and VASN*R161Q and an adverse role of AMBP*A286G and CD55*S162L in PCa patients. This work originally characterized the urinary proteome, focusing on the proteogenome profile of PCa patients, which is usually overlooked in the analysis of PCa and body fluids. Combined analysis of mass spectrometry data using two different software packages was performed for the first time in the context of PCa, which increased the robustness of the data analysis. The application of proteogenomics to urine proteomic analysis can be very enriching in mutation-related diseases such as cancer.

Proteomics and Metabolomics Profiling of Platelets and Plasma Mediators of Thrombo-Inflammation in Gestational Hypertension and Preeclampsia

Platelets may be pivotal mediators of the thrombotic and coagulopathic complications of preeclampsia (PE), linking inflammation and thrombosis with endothelial and vascular dysfunction. Both PE and gestational hypertension (GH) fall within the spectrum of hypertensive complications of pregnancy, with GH being a risk factor for preeclampsia. However, it is unclear what biomarkers distinguish PE from GH. Using a discovery size cohort, we aimed to characterize specific plasma and platelet thrombo-inflammatory drivers indicative of PE and differentiate PE from GH. We performed multiplex immunoassays, platelet and plasma quantitative proteomics and metabolomics of PE patients, comparing with non-pregnant (NP), healthy pregnant controls (PC) and GH participants. The expression pattern of plasma proteins and metabolites in PE/GH platelets was distinct from that of NP and PC. Whilst procoagulation in PC may be fibrinogen driven, inter-alpha-trypsin inhibitors ITIH2 and ITIH3 are likely mediators of thrombo-inflammation in GH and PE, and fibronectin and S100A8/9 may be major procoagulant agonists in PE only. Also enriched in PE were CCL1 and CCL27 plasma cytokines, and the platelet leucine-rich repeat-containing protein 27 and 42 (LRRC27/42), whose effects on platelets were explored using STRING analysis. Through protein-protein interactions analysis, we generated a new hypothesis for platelets’ contribution to the thrombo-inflammatory states of preeclampsia.

Inter-Alpha-Trypsin Inhibitor Heavy Chain 4 Plays an Important Role in the Development and Reproduction of Nilaparvata lugens

Simple Summary

The brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae), is a destructive insect pest of rice. It causes reductions in rice yield and great economic losses. In this study, we used RNAi to explore the function of the inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) gene in the development and reproduction of the brown planthopper. Our results revealed that ITIH4 influences the survival, ovarian development, egg production, and egg hatching of this insect, indicating that ITIH4 plays important roles in development and reproduction. Considering the importance of ITIH4 in the brown planthopper, it may be a potential target for pest management.

Abstract

The brown planthopper, Nilaparvata lugens, is a difficult-to-control insect pest affecting rice yields in Asia. As a structural component of the inter-alpha-trypsin inhibitor (ITI), the inter-alpha-trypsin inhibitor heavy chain (ITIH) has been reported to be involved in various inflammatory or malignant disorders, ovarian development, and ovulation. To reveal the function of ITIH4 in N. lugens, the gene encoding N. lugens ITIH4 (NlITIH4) was cloned and characterized. NlITIH4 contains a signal peptide, a vault protein inter-alpha-trypsin domain, and a von Willebrand factor type A domain. qPCR analysis showed that NlITIH4 was expressed at all developmental stages and in all tissues (fat body, ovary, and gut), with the highest expression in the fat body. Double stranded NlITIH4 (dsNlITIH4) injection clearly led to an RNAi-mediated inhibition of the expression of NlITIH4 and resulted in reduced survival, delayed ovarian development, and reduced egg production and egg hatching. These results indicate that NlITIH4 plays an important role in the development and reproduction of N. lugens.

Preliminary exploration on the serum biomarkers of bloodstream infection with carbapenem-resistant Klebsiella pneumoniae based on mass spectrometry

Background

Carbapenem‐resistant K. pneumoniae (CRKP) bloodstream infections (BSI) must be rapidly identified to improve patient survival rates. This study investigated a new mass spectrometry‐based method for improving the identification of CRKP BSI and explored potential biomarkers that could differentiate CRKP BSI from sensitive.

Methods

Mouse models of BSI were first established. MALDI‐TOF MS was then used to profile serum peptides in CRKP BSI versus normal samples before applying BioExplorer software to establish a diagnostic model to distinguish CRKP from normal. The diagnostic value of the model was then tested against 32 clinical CRKP BSI and 27 healthy serum samples. Finally, the identities of the polypeptides used to establish the diagnostic model were determined by secondary mass spectrometry.

Results

107 peptide peaks were shared between the CRKP and normal groups, with 18 peaks found to be differentially expressed. Five highly expressed peptides in the CRKP group (m/z 1349.8, 2091.3, 2908.2, 4102.1, and 8129.5) were chosen to establish a diagnostic model. The accuracy, specificity and sensitivity of the model were determined as 79.66%, 81.48%, and 78.12%, respectively. Secondary mass spectrometry identified the Fibrinogen alpha chain (FGA), Inter‐alpha‐trypsin inhibitor heavy chain H4 (ITIH4) and Serum amyloid A‐2 protein (SAA2) as the source of the 5 serum peptides.

Conclusions

We successfully established a serum peptide‐based diagnostic model that distinguished clinical CRKP BSI samples from normal healthy controls. The application of MALDI‐TOF MS to measure serum peptides, therefore, represents a promising approach for early BSI diagnosis of BSI, especially for multidrug‐resistant bacteria where identification is urgent.

Measurement of ITIH4 and Hp levels in bitches with pyometra using newly developed ELISA methods

Measurement of acute phase proteins (APPs) as biomarkers in canine medicine is in increasing demand. In the present study, the development and validation of two ELISA methods for the quantification of canine inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) and haptoglobin (Hp) are shown. The adequate imprecision and accuracy and wide analytical range make the developed methods appropriate to quantify ITIH4 and Hp in serum samples. The inter- and intra-assay CVs were lower than 10 %, and the assays maintained linearity under dilution and showed analytical equivalence with the method of radial immunodiffusion. The measurement of CRP, Hp and ITIH4 in sera from bitches affected by pyometra allowed us to determine that ITIH4 behaves as a moderate APP in dogs. The group of bitches affected by pyometra showed very high levels of CRP (147 ± 91 mg/L), corresponding to a strong inflammatory process, which resulted in a moderate increase in the concentrations of Hp (7 times) and ITIH4 (3 times) compared to the control group.

Potential of Antithrombin III as a Biomarker of Antidepressive Effect in Major Depressive Disorder

Background: The evaluation of treatment response to antidepressant therapy commonly depends on neuropsychologic assessments, as there are currently no suitable biomarkers. Previous research has identified a panel of increased proteins in patients with major depressive disorder (MDD), including antithrombin III (ATIII), as potential biomarkers of depression. Methods: A total of 90 MDD patients were recruited. Of these, 74 patients received occipital repetitive transcranial magnetic stimulation (rTMS) as individualized, standard, or sham treatment for 5 days, and underwent the complete procedure, including clinical assessments, blood collection, and protein measurement. Results: After treatment, ATIII was significantly decreased in both the individualized and standard groups (both p < 0.001) relative to the sham group. In the individualized group, reduction in ATIII was associated with improvements in several neuropsychological assessments. Furthermore, ATIII at baseline in the standard group and after individualized rTMS showed good performance for evaluating or predicting the response to five-day treatment (AUC = 0.771, 95% CI, 0.571-0.971; AUC = 0.875, 95% CI, 0.714-1.000, respectively) and remission at follow-up (AUC = 0.736, 95% CI, 0.529-0.943; AUC = 0.828, 95% CI, 0.656-1.000, respectively). Lastly, both baseline ATIII and change in ATIII showed good predictive value for the 24-item Hamilton Depression Rating Scale at follow-up (p = 0.024 and 0.023, respectively). Conclusion: Our study revealed a reduction in ATIII after occipital rTMS in MDD patients and a relationship between change in ATIII and therapeutic response. Taken together, these findings provide evidence for the potential of ATIII as a biomarker for the evaluation and prediction of antidepressive effects.

Staphylococcus aureus-induced proteomic changes in the mammary tissue of rats: A TMT-based study

Staphylococcus aureus is one of the most important pathogens causing mastitis in dairy cows. The objective of this study was to establish a rat model of mastitis induced by S. aureus infection and to explore changes in the proteomes of mammary tissue in different udder states, providing a better understanding of the host immune response to S. aureus mastitis. On day 3 post-partum, 6 rats were randomly divided into two groups (n = 3), with either 100 μL of PBS (blank group) or a S. aureus suspension containing 2×10⁷ CFU·mL⁻¹ (challenge group) infused into the mammary gland duct. After 24 h of infection, the rats were sacrificed, and mammary gland tissue was collected. Tandem mass tag (TMT)-based technology was applied to compare the proteomes of healthy and mastitic mammary tissues. Compared with the control group, the challenge group had 555 proteins with significant differences in expression, of which 428 were significantly upregulated (FC>1.2 and p<0.05) and 127 were downregulated (FC>0.83 and p<0.05 or p<0.01). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that upregulated differentially significant expressed proteins (DSEPs) were associated with mainly immune responses, including integrin alpha M, inter-α-trypsin inhibitor heavy chain 4, and alpha-2-macroglobulin. This study is the first in which a rat model of S. aureus-induced mastitis was used to explore the proteins related to mastitis in dairy cows by TMT technology, providing a model for replication of dairy cow S. aureus-induced mastitis experiments.

Identification of New Peptide Biomarkers for Bacterial Bloodstream Infection

PURPOSE

Due to a lack of effective early diagnostic measures, new diagnostic methods for bacterial bloodstream infections (BSIs) are urgently needed. A protein-peptide profiling approach can be used to identify novel diagnostic biomarkers of BSIs.

EXPERIMENTAL DESIGN

In this study, MALDI-TOF MS and nano-LC/ESI-MS/MS are used to analyze serum peptides. In addition, GO and network analyses are conducted as a means of analyzing these potential protein markers. Finally, the potential biomarkers are verified in independent clinical samples via ELISA.

RESULTS

m/z 1533.8, 2794.3, 3597.3, 5007.3, and 7816.7 reveal an identical trend; the intensity of m/z 1533.8, 2794.3, and 3597.3 are higher in the infection group relative to controls, whereas the intensity of m/z 5007.3 and 7816.7 are lower in the infection group. Four peaks are successfully identified including ITIH4, KNG1, SAA2, and C3. GO and network analyses find these proteins to form an interaction network, which may be correlated with BSI. ELISA results indicate that ITIH4, KNG1, and SAA2 are effective in differentiating infected from normal control group and the febrile group.

CONCLUSIONS AND CLINICAL RELEVANCE

These biomarkers have the potential to offer new insights into the signaling networks underlying the development and progression of BSI.

Development and validation of an ELISA for the quantification of bovine ITIH4 in serum and milk

Inter alpha trypsin inhibitor heavy chain 4 (ITIH4) is a serum protein belonging to the Inter alpha trypsin inhibitor (ITI) family, which was previously characterized by our group as a new APP in cattle. This protein was firstly described in pigs where is known to be a major acute phase protein, also denominated Pig-MAP. Increases of ITIH4 of up to 12 times the pre-infection values were previously reported in the serum of heifers with experimentally induced summer mastitis. ITIH4 was detected in the milk of cows with mastitis by western blot, but the method previously used to quantify this protein, radial immunodiffusion, was not sensitive enough to quantify it in milk samples. In this study we developed an ELISA method which allows the quantification of bovine ITIH4 in serum and milk samples. Previously developed antibodies were used to perform the assay, including anti bovine ITIH4 polyclonal antibodies and a monoclonal antibody against pig ITIH4 that also recognizes the bovine homologous protein. The ELISA developed showed an adequate precision, with inter and intra- assay coefficients of variation lower than 10% for serum and milk samples. The assay keeps linearity under dilution for both serum and milk samples. A good agreement was observed between the values measured by ELISA and radial immunodiffusion in serum samples.

Elevated levels of circulating ITIH4 are associated with hepatocellular carcinoma with nonalcoholic fatty liver disease: from pig model to human study

BACKGROUND

Noninvasive biomarkers are urgently needed for optimal management of nonalcoholic fatty liver disease (NAFLD) for the prevention of disease progression into nonalcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). In order to identify the biomarkers, we generated the swine hepatocellular carcinoma (HCC) model associated with NAFLD and performed serum proteomics on the model.

METHODS

Microminipigs were fed a high-fat diet to induce NAFLD and a normal diet as the control. To induce HCC, diethylnitrosamine was intraperitoneally administered. Biopsied liver samples were histopathologically analyzed every 12 weeks. Serum proteins were separated by blue native two-dimensional gel electrophoresis and proteins of interest were subsequently identified by MALDI-TOF MS/MS. Human serum samples were analyzed to validate the candidate protein using antibody-mediated characterization.

RESULTS

In the NAFLD pigs, hepatic histology of nonalcoholic steatohepatitis (NASH) was observed at 36 weeks, and HCC developed at 60 weeks. Among serum proteins identified with MALDI-TOF MS/MS, serum inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), an acute response protein which is secreted primarily by liver, was identified as the most characteristic protein corresponding with NAFLD progression and HCC development in the NAFLD pigs. With immunoassay, serum ITIH4 levels in the NAFLD pigs were chronologically increased in comparison with those in control animal. Furthermore, immunohistochemistry showed ITIH4 expression in hepatocytes also increased in both the cancer lesions and parenchyma as NAFLD progressed. Human study is also consistent with this observation because serum ITIH4 levels were significantly higher in HCC-NAFLD patients than in the simple steatosis, NASH, and virus-related HCC patients. Of note, HCC-NAFLD patients who had higher serum ITIH4 levels exhibited poorer prognosis after hepatectomy.

CONCLUSIONS

We established an HCC pig model associated with NAFLD. Serum proteomics on the swine HCC with NAFLD model implicated ITIH4 as a non-invasive biomarker reflecting NAFLD progression as well as subsequent HCC development. Most importantly, the results in the swine study have been validated in human cohort studies. Dissecting speciation of serum ITIH4 promises to have clinical utility in monitoring the disease.

Serum IgM Glycosylation Associated with Tuberculosis Infection in Mice

Changes in serum glycans discriminate between disease statuses in cancer. A similar connection has not been established in the context of infectious diseases such as tuberculosis (TB). The inflammation arising from infection by Mycobacterium tuberculosis may affect host protein glycosylation, thereby providing information about disease status in TB. A mouse model of infection was used to study glycoprotein N-glycosylation in serum. Following digestion of serum glycoproteins with peptide-N-glycosidase F (PNGase F), released glycans were permethylated and analyzed by multidimensional mass spectrometry (MS). Conditions included naive or Mycobacterium bovis BCG-vaccinated animals, which were either uninfected or infected with M. tuberculosis MS results were validated by lectin blotting. We found that both glycoprotein fucosylation and sialylation were particularly sensitive to M. tuberculosis infection. We observed that M. tuberculosis infection elevates serum IgM levels and induces changes in glycosylation that could inform about the disease.IMPORTANCE We demonstrate that M. tuberculosis infection influenced host protein glycosylation in a mouse model. The mechanism by which infection modifies glycans in serum proteins is not understood. Investigation of the regulation of such modifications by M. tuberculosis opens a new field that could lead to the discovery of novel biomarkers. Validation of such findings in human samples will reveal the clinical relevance of these findings.

Characterization of the plasma proteome of nonhuman primates during Ebola virus disease or melioidosis: a host response comparison

Background

In-depth examination of the plasma proteomic response to infection with a wide variety of pathogens can assist in the development of new diagnostic paradigms, while providing insight into the interdependent pathogenic processes which encompass a host’s immunological and physiological responses. Ebola virus (EBOV) causes a highly lethal infection termed Ebola virus disease (EVD) in primates and humans. The Gram negative non-spore forming bacillus Burkholderia pseudomallei (Bp) causes melioidosis in primates and humans, characterized by severe pneumonia with high mortality. We sought to examine the host response to infection with these two bio-threat pathogens using established animal models to provide information on the feasibility of pre-symptomatic diagnosis, since the induction of host molecular signaling networks can occur before clinical presentation and pathogen detection.

Methods

Herein we report the quantitative proteomic analysis of plasma collected at various times of disease progression from 10 EBOV-infected and 5 Bp-infected nonhuman primates (NHP). Our strategy employed high resolution LC–MS/MS and a peptide-tagging approach for relative protein quantitation. In each infection type, for all proteins with > 1.3 fold abundance change at any post-infection time point, a direct comparison was made with levels obtained from plasma collected daily from 5 naïve rhesus macaques, to determine the fold changes that were significant, and establish the natural variability of abundance for endogenous plasma proteins.

Results

A total of 41 plasma proteins displayed significant alterations in abundance during EBOV infection, and 28 proteins had altered levels during Bp infection, when compared to naïve NHPs. Many major acute phase proteins quantitated displayed similar fold-changes between the two infection types but exhibited different temporal dynamics. Proteins related to the clotting cascade, immune signaling and complement system exhibited significant differential abundance during infection with EBOV or Bp, indicating a specificity of the response.

Conclusions

These results advance our understanding of the global plasma proteomic response to EBOV and Bp infection in relevant primate models for human disease and provide insight into potential innate immune response differences between viral and bacterial infections.

Electronic supplementary material

The online version of this article (10.1186/s12014-019-9227-3) contains supplementary material, which is available to authorized users.

Merkel cell polyomavirus and Langerhans cell neoplasm

BACKGROUND

The relationship between various external agents such as pollen, food, and infectious agents and human sensitivity exists and is variable depending upon individual's health conditions. For example, we believe that the pathogenetic potential of the Merkel cell polyomavirus (MCPyV), the resident virus in skin, is variable and depends from the degree of individual's reactivity. MCPyV as well as Epstein-Barr virus, which are normally connected with humans under the form of subclinical infection, are thought to be involved at various degrees in several neoplastic and inflammatory diseases. In this review, we cover two types of Langerhans cell neoplasms, the Langerhans cell sarcoma (LCS) and Langerhans cell histiocytosis (LCH), represented as either neoplastic or inflammatory diseases caused by MCPyV.

METHODS

We meta-analyzed both our previous analyses, composed of quantitative PCR for MCPyV-DNA, proteomics, immunohistochemistry which construct IL-17 endocrine model and interleukin-1 (IL-1) activation loop model, and other groups' data.

RESULTS

We have shown that there were subgroups associated with the MCPyV as a causal agent in these two different neoplasms. Comparatively, LCS, distinct from the LCH, is a neoplastic lesion (or sarcoma) without presence of inflammatory granuloma frequently observed in the elderly. LCH is a proliferative disease of Langerhans-like abnormal cells which carry mutations of genes involved in the RAS/MAPK signaling pathway. We found that MCPyV may be involved in the development of LCH.

CONCLUSION

We hypothesized that a subgroup of LCS developed according the same mechanism involved in Merkel cell carcinoma pathogenesis. We proposed LCH developed from an inflammatory process that was sustained due to gene mutations. We hypothesized that MCPyV infection triggered an IL-1 activation loop that lies beneath the pathogenesis of LCH and propose a new triple-factor model.

Plasma proteins associated with circulating carotenoids in Nepalese school-aged children

Carotenoids are naturally occurring pigments that function as vitamin A precursors, antioxidants, anti-inflammatory agents or biomarkers of recent vegetable and fruit intake, and are thus important for population health and nutritional assessment. An assay approach that measures proteins could be more technologically feasible than chromatography, thus enabling more frequent carotenoid status assessment. We explored associations between proteomic biomarkers and concentrations of 6 common dietary carotenoids (α-carotene, β-carotene, lutein/zeaxanthin, β-cryptoxanthin, and lycopene) in plasma from 500 6-8 year old Nepalese children. Samples were depleted of 6 high-abundance proteins. Plasma proteins were quantified using tandem mass spectrometry and expressed as relative abundance. Linear mixed effects models were used to determine the carotenoid:protein associations, accepting a false discovery rate of q < 0.10. We quantified 982 plasma proteins in >10% of all child samples. Among these, relative abundance of 4 were associated with β-carotene, 11 with lutein/zeaxanthin and 51 with β-cryptoxanthin. Carotenoid-associated proteins are notably involved in lipid and vitamin A transport, antioxidant function and anti-inflammatory processes. No protein biomarkers met criteria for association with α-carotene or lycopene. Plasma proteomics may offer an approach to assess functional biomarkers of carotenoid status, intake and biological function for public health application. Original maternal micronutrient trial from which data were derived as a follow-up activity was registered at ClinicalTrials.gov: NCT00115271.

Serum proteome profiling in canine idiopathic dilated cardiomyopathy using TMT-based quantitative proteomics approach

Idiopathic dilated cardiomyopathy (iDCM) is a primary myocardial disorder with an unknown aetiology, characterized by reduced contractility and ventricular dilation of the left or both ventricles. Naturally occurring canine iDCM was used herein to identify serum proteomic signature of the disease compared to the healthy state, providing an insight into underlying mechanisms and revealing proteins with biomarker potential. To achieve this, we used high-throughput label-based quantitative LC-MS/MS proteomics approach and bioinformatics analysis of the in silico inferred interactome protein network created from the initial list of differential proteins. To complement the proteomic analysis, serum biochemical parameters and levels of know biomarkers of cardiac function were measured. Several proteins with biomarker potential were identified, such as inter-alpha-trypsin inhibitor heavy chain H4, microfibril-associated glycoprotein 4 and apolipoprotein A-IV, which were validated using an independent method (Western blotting) and showed high specificity and sensitivity according to the receiver operating characteristic curve analysis. Bioinformatics analysis revealed involvement of different pathways in iDCM, such as complement cascade activation, lipoprotein particles dynamics, elastic fibre formation, GPCR signalling and respiratory electron transport chain.

SIGNIFICANCE

Idiopathic dilated cardiomyopathy is a severe primary myocardial disease of unknown cause, affecting both humans and dogs. This study is a contribution to the canine heart disease research by means of proteomic and bioinformatic state of the art analyses, following similar approach in human iDCM research. Importantly, we used serum as non-invasive and easily accessible biological source of information and contributed to the scarce data on biofluid proteome research on this topic. Bioinformatics analysis revealed biological pathways modulated in canine iDCM with potential of further targeted research. Also, several proteins with biomarker potential have been identified and successfully validated.

Significant changes in ITIH4, AHSG, ORM1, and CD46 content in milk fat globule membrane proteins of ketotic dairy cows

High concentrations of non-esterified fatty acid (NEFA) and β-hydroxybutyrate (BHBA) in cows' blood caused by ketosis are associated with inflammatory states. We hypothesised that ketosis in postparturient dairy cows would result in altered levels on inflammation-related proteins not only in plasma but also in the milk fat globule membranes (MFGM). Thirty cows were selected from a dairy farm in Heilongjiang, China. Inflammatory milk fat globule membrane proteins were detected using ELISA kits, and a fully automatic biochemical analyser was used to measure the concentrations of BHBA, NEFA, glucose (GLU) and triglyceride (TG) in plasma. MFGM protein from milk of ketotic cows contained significantly different concentrations of acute-phase response proteins (complement C3 (C3), prothrombin (F2), alpha-1-acid glycoprotein (ORM1), inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), alpha-2-HS-glycoprotein (AHSG), complement C9 (C9), complement regulatory protein variant 4 (CD46)) in comparison with milk from non-ketotic cows. Blood concentrations of C3, complement C9 (C9), tumour necrosis factor α (TNFα), MFGM C3, monocyte differentiation antigen CD14 (CD14) and ORM1 levels were correlated with energy balance. ITIH4 and CD46 increased, and AHSG and ORM1 decreased before the onset of ketosis. These biomarkers offer potential as predictors and monitors of ketosis in at-risk cows.

Hyaluronic Acid Coated Chitosan Nanoparticles Reduced the Immunogenicity of the Formed Protein Corona

Studying the interactions of nanoparticles (NPs) with serum proteins is necessary for the rational development of nanocarriers. Optimum surface chemistry is a key consideration to modulate the formation of the serum protein corona (PC) and the resultant immune response. We investigated the constituent of the PC formed by hyaluronic acid-coated chitosan NPs (HA-CS NPs). Non-decorated chitosan NPs (CS NPs) and alginate-coated chitosan NPs (Alg-CS NPs) were utilized as controls. Results show that HA surface modifications significantly reduced protein adsorption relative to controls. Gene Ontology analysis demonstrates that HA-CS NPs were the least immunogenic nanocarriers. Indeed, less inflammatory proteins were adsorbed onto HA-CS NPs as opposed to CS and Alg-CS NPs. Interestingly, HA-CS NPs differentially adsorbed two unique anti-inflammatory proteins (ITIH4 and AGP), which were absent from the PC of both controls. On the other hand, CS and Alg-CS NPs selectively adsorbed a proinflammatory protein (Clusterin) that was not found on the surfaces of HA-CS NPs. While further studies are needed to investigate abilities of the PCs of only ITIH4 and AGP to modulate the interaction of NPs with the host immune system, our results suggest that this proof-of-concept could potentially be utilized to reduce the immunogenicity of a wide range of nanomaterials.

Serum biomarkers predictive of pre-eclampsia

AIM

We sought serum biomarkers predictive of pre-eclampsia (PE).

MATERIALS & METHODS

Sera obtained at 12-14 weeks of pregnancy from 24 cases who later developed PE and 24 controls with uncomplicated pregnancies were processed and analyzed using a serum proteomic approach.

RESULTS

Many statistically significant serum PE biomarker candidates (n > 60) were found comparing cases and controls. In addition, logistic regression analysis modeled biomarker data resulted in 14 different multimarker combinations having high detection sensitivity and specificity (AUC >0.9).

CONCLUSIONS

Developed panels of serum biomarkers appeared effective in identifying pregnant women at 12-14 weeks gestation at risk of PE later in their pregnancy.

Acute-phase ITIH4 levels distinguish multi-system from single-system Langerhans cell histiocytosis via plasma peptidomics

BACKGROUND

Langerhans cell histiocytosis (LCH) is a proliferative disorder in which abnormal Langerhans cell (LC)-like cells (LCH cells) intermingle with inflammatory cells. Whether LCH is reactive or neoplastic remains a controversial matter. We recently described Merkel cell polyomavirus (MCPyV) as a possible causative agent of LCH and proposed interleukin-1 loop model: LCH is a reactive disorder with an underlying oncogenic potential and we now propose to test this theory by looking for acute markers of inflammation. We detected MCPyV-DNA in the peripheral blood cells of patients with high-risk organ-type (LCH-risk organ (RO) (+)) but not those with non-high-risk organ-type LCH (LCH-RO (-)); this difference was significant. LCH-RO (-) is further classified by its involvement of either a single organ system (SS-LCH) or multiple organ systems (MS-LCH). In patients with LCH-RO (-), MCPyV-DNA sequences were present in LCH tissues, and significant differences were observed between LCH tissues and control tissues associated with conditions such as dermatopathic lymphadenopathy and reactive lymphoid hyperplasia. Although MCPyV causes subclinical infection in nearly all people and 22 % of healthy adults will harbor MCPyV in their buffy coats, circulating monocytes could serve as MCPyV reservoirs and cause disseminated skin lesions.

METHODS

Plasma sample from 12 patients with LCH-RO (-) (5 MS-LCH and 7 SS-LCH) and 5 non-LCH patients were analyzed by peptidomics. Mass spectrometry (MS) spectra were acquired and peptides exhibiting quantitative differences between MS-LCH and SS-LCH patients were targeted.

RESULTS

One new candidate biomarker, m/z 3145 was selected and identified after obtaining a MS/MS fragmentation pattern using liquid chromatography-MS/MS. This peak was identified as a proteolytic fragment derived from inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4, [PDB: Q14624]).

CONCLUSIONS

Peptidomics of LCH have revealed that the level of acute-phase ITIH4 distinguishes MS-LCH-RO (-) from SS-LCH-RO (-). Acute-phase proteins serve non-specific, physiological immune functions within the innate immune system. LCH may be a reactive disorder with both underlying neoplastic potential of antigen presenting cells harboring BRAF mutations and hyper-immunity of other inflammatory cells against MCPyV infection. Among LCH-RO (-), MCPyV-DNA sequences were present in both MS-LCH tissues and SS-LCH tissues without significant differences. ITIH4 may show that LCH activity or LCH subtypes correlates with the systemic or localized reactions of MCPyV infection.

iTRAQ-based quantitative proteomic analysis of longissimus muscle from growing pigs with dietary supplementation of non-starch polysaccharide enzymes

Non-starch polysaccharide enzymes (NSPEs) have long been used in the feed production of monogastric animals to degrade non-starch polysaccharide to oligosaccharides and promote growth performance. However, few studies have been conducted on the effect of such enzymes on skeletal muscle in monogastric animals. To elucidate the mechanism of the effect of NSPEs on skeletal muscle, an isobaric tag for relative and absolute quantification (iTRAQ) for differential proteomic quantitation was applied to investigate alterations in the proteome in the longissimus muscle (LM) of growing pigs after a 50-d period of supplementation with 0.6% NSPEs in the diet. A total of 51 proteins were found to be differentially expressed in the LM between a control group and the NSPE group. Functional analysis of the differentially expressed protein species showed an increased abundance of proteins related to energy production, protein synthesis, muscular differentiation, immunity, oxidation resistance and detoxification, and a decreased abundance of proteins related to inflammation in the LM of the pigs fed NSPEs. These findings have important implications for understanding the mechanisms whereby dietary supplementation with NSPEs enzymes can promote growth performance and improve muscular metabolism in growing pigs.

Comparative serum proteome expression of the steroid-induced femoral head osteonecrosis in adults

Steroid-induced osteonecrosis of the femoral head (SONFH) is a disabling, aseptic and ischemic disease that develops following steroid therapy. The pathogenesis of SONFH is unclear, so the early diagnosis and treatment for this disease is yet to be established. The purpose of the present study was to identify potential biomarkers for SONFH. The differential expression of serum proteins from patients with SONFH and healthy volunteers was analyzed by the proteomics method. The protein samples were labeled and subjected to isoelectric focusing and two-dimensional gel electrophoresis. The resultant protein spots were matched and quantified by an imaging analysis system. The differentially-expressed protein spots were subjected to in-gel trypsin digestion followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Significantly lower levels of complement component 3 (C3), C4, inter-α-trypsin inhibitor heavy chain H4 and α-2-macroglobulin were found in the serum of patients with SONFH. These proteins are reported to be actively involved in intravascular coagulation, apoptosis and reactive oxygen species imbalance, indicating that multiple pathological reactions occur in SONFH and these proteins may serve as potential biomarkers for the diagnosis of SONFH.

iTRAQ-proteomics and bioinformatics analyses of mammary tissue from cows with clinical mastitis due to natural infection with Staphylococci aureus

Background

Proteomics and bioinformatics may help us better understand the biological adaptations occurring during bovine mastitis. This systems approach also could help identify biomarkers for monitoring clinical and subclinical mastitis. The aim of the present study was to use isobaric tags for relative and absolute quantification (iTRAQ) to screen potential proteins associated with mastitis at late infectious stage.

Results

Healthy and mastitic cows’ mammary gland tissues were analyzed using iTRAQ combined with two-dimensional liquid chromatography-tandem mass spectrometry (2D-LC-MS/MS). Bioinformatics analyses of differentially expressed proteins were performed by means of Gene Ontology, metabolic pathways, transcriptional regulation networks using Blast2GO software, the Dynamic Impact Approach and Ingenuity Pathway Analysis. At a false discovery rate of 5%, a total of 768 proteins were identified from 6,499 peptides, which were matched with 15,879 spectra. Compared with healthy mammary gland tissue, 36 proteins were significantly up-regulated (>1.5-fold) while 19 were significantly down-regulated (<0.67-fold) in response to mastitis due to natural infections with Staphylococci aureus. Up-regulation of collagen, type I, alpha 1 (COL1A1) and inter-alpha (Globulin) inhibitor H4 (ITIH4) in the mastitis-infected tissue was confirmed by Western blotting and Immunohistochemistry.

Conclusion

This paper is the first to show the protein expression in the late response to a mastitic pathogen, thus, revealing mechanisms associated with host tissue damage. The bioinformatics analyses highlighted the effects of mastitis on proteins such as collagen, fibrinogen, fibronectin, casein alpha and heparan sulfate proteoglycan 2. Our findings provide additional clues for further studies of candidate genes for mastitis susceptibility. The up-regulated expression of COL1A1 and ITIH4 in the mastitic mammary gland may be associated with tissue damage and repair during late stages of infection.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-839) contains supplementary material, which is available to authorized users.

A proteomics approach to the identification of plasma biomarkers for latent tuberculosis infection

A proteomic analysis was performed to screen the potential latent tuberculosis infection (LTBI) biomarkers. A training set of spectra was used to generate diagnostic models, and a blind testing set was used to determine the accuracy of the models. Candidate peptides were identified using nano-liquid chromatography-electrospray ionization–tandem mass spectrometry. Based on the training set results, 3 diagnostic models recognized LTBI subjects with good cross-validation accuracy. In the blind testing set, LTBI subjects could be identified with sensitivities and specificities of 85.20% to 88.90% and 85.7% to 100%, respectively. Additionally, 14 potential LTBI biomarkers were identified, and all proteins were identified for the first time through proteomics in the plasma of healthy, latently infected individuals. In all, proteomic pattern analyses can increase the accuracy of LTBI diagnosis, and the data presented here provide novel insights into potential mechanisms involved in LTBI.

Protein profile of the seminal plasma of collared peccaries (Pecari tajacu Linnaeus, 1758)

This study was conducted to characterize the major proteins of the peccary seminal plasma, based on the semen samples collected from nine adult and reproductively sound animals. Our approach included the use of two-dimensional electrophoresis followed by Coomassie blue staining and analysis of polypeptide maps with PDQuest Software (Bio-Rad). Proteins were identified by tandem mass spectrometry (LC-MS/MS). We detected 179 protein spots per gel and 98 spots were identified by mass spectrometry, corresponding to 23 different proteins. The combined intensity of those spots accounted for 56.2±6% of the intensities of all spots and 60.9% of the intensities of spots presented in every protein map. Protein spots identified as clusterin represented 19.7±8.3% of the integrated optical densities of all spots detected in the seminal plasma maps. There was a negative association (r=-0.87; P<0.05) between the intensity of a clusterin spot and the percentage of sperm with functional membrane. Spermadhesin porcine seminal plasma protein 1 and bodhesin 2 comprised 5.4±1.9 and 8.8±3.9% of the total intensity of all spots respectively. Many proteins appeared in a polymorphic pattern, such as clusterin (27 spots), epididymal secretory glutathione peroxidase (ten spots), inter-α-trypsin inhibitor (12 spots), and IgG-binding protein (ten spots), among others. In conclusion, we presently describe the major seminal plasma proteome of the peccary, which exhibits a distinct high expression of clusterin isoforms. Knowledge of wild species reproductive biology is crucial for an understanding of their survival strategies and adaptation in a changing environment.

Serum Inter-Alpha-Trypsin Inhibitor Heavy Chain 4 (ITIH4) in Children with Chronic Hepatitis C: Relation to Liver Fibrosis and Viremia

Liver fibrosis and viremia are determinant factors for the treatment policy and its outcome in chronic hepatitis C virus (HCV) infection. We aimed to investigate serum level of inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) and its relation to liver fibrosis and viremia in children with chronic HCV. ITIH4 was measured by ELISA in 33 treatment-naive children with proved chronic HCV and compared according to different clinical, laboratory and histopathological parameters. Liver histopathological changes were assessed using Ishak score and compared with aspartate transaminase-to-platelet ratio (APRI) and FIB-4 indices as simple noninvasive markers of fibrosis. ITIH4 was measured in a group of 30 age- and sex-matched healthy controls. ITIH4 was significantly higher in patients than in controls (54.2 ± 30.78 pg/mL versus 37.21 ± 5.39 pg/mL; P = 0.021). ITIH4, but not APRI or FIB-4, had a significant direct correlation with fibrosis stage (P = 0.015, 0.961, and 0.389, resp.), whereas, the negative correlation of ITIH4 with HCV viremia was of marginal significance (P = 0.071). In conclusion, ITIH4 significantly correlated with higher stages of fibrosis indicating a possible relation to liver fibrogenesis. The trend of higher ITIH4 with lower viremia points out a potential antiviral properties and further studies in this regard are worthwhile.

Screening differentially expressed serum proteins in gastric cancer by iTRAQ labeling coupled with 2D-LC-MS/MS

AIM: To screen serum differentially expressed proteins in gastric cancer (GC) patients and search biomarkers for GC diagnosis.

METHODS: Forty-five serum samples from GC patients and 45 from normal controls were collected. High-abundance proteins in serum were removed by immune-chromatography assay. Isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional liquid chromatography/tandem mass spectrometry (2D-LC-MS/MS) were used to analyze and identify differentially expressed serum proteins between the two groups. Bioinformatics was used to analyze the identified differentially expressed proteins, and the expression of representative differential proteins was verified by Western blot.

RESULTS: The iTRAQ coupled with 2D-LC-MS/MS analysis led to the identification of a total of 199 proteins, of which 17 were differentially expressed proteins between the two groups, including 12 up-regulated ones and 5 down-regulated ones in GC patients.These differentially expressed proteins are involved in 10 biological processes, 9 molecular functions and 2 cellular components. Western blot results showed that compared with the normal control controls, the expression of representative differential protein ITIH4 in serum of GC patients was significantly up-regulated (1.7517 ± 0.247 vs 1 ± 0, P < 0.05).

CONCLUSION: ITIH4 may be used as a new potential biomarker for diagnosis of GC.

A proteomic study of plasma protein changes under extreme physical stress

The Spartathlon race (brisk walking a distance of 246km in less than 36h) was employed as a model of severe physical stress to investigate proteomic alterations in the plasma of athletes at the start (Athens) and finish (Sparta) of the race, as well as 48h after the race (Post). The athletes' plasma was analyzed by 2D gel electrophoresis (2-DE) and the differentially expressed proteins were identified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS). The ProteoSeek™ Albumin/IgG removal kit and the ProteoMiner™ enrichment kit were utilized to detect medium- and low-abundance proteins, whose expression may be masked due to high-abundance proteins. Our results were confirmed by Western blot and biochemical analyses. Overall fifty-two proteins were differentially expressed between the starting point, the finishing line and two days after the end of the race. Of these, thirty proteins were involved in inflammation, while the rest concerned anti-oxidation, anti-coagulation and iron and vitamin D transport. These results indicate that prolonged physical stress affects circulating stress-related proteins, which might be employed as biomarkers of stress-related diseases.

BIOLOGICAL SIGNIFICANCE

The current study employed the Spartathlon, as a model of prolonged endurance exercise, to identify and isolate putative biomarkers of inflammation under extreme physical stress conditions. These protein quantitative variations may pave the way to exploration and understanding of stress-related physiological processes, the stress response itself and diseases whose onset appears to be linked to stress.

ITIH4: A New Potential Biomarker of "Toxin Syndrome" in Coronary Heart Disease Patient Identified with Proteomic Method

Objective. This trial aims to look for the protein biomarker of "toxin syndrome" of CHD patients. Methods. We have performed two trials in this paper. The first trial was a randomized controlled trial (RCT) of the plasma proteome in unstable angina (UA) patients by Maldi-Tof Mass. The second trial was a nested case-control study in 1503 stable CHD patients with one-year followup for acute cardiovascular events (ACEs). Results. In the RCT study, 12 protein spots were found to be the differential protein for the significant differences between the difference of before and after treatment in group A and group B; 2 of them (3207.37 Da and 4279.95 Da) was considered to be unique to "toxin syndrome" for being differential proteins of group B but not group A. These 2 spots were identified as Isoform 1 of Fibrinogen alpha chain precursor (FGA, 3207.37 Da) and Isoform 2 of inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4, 4279.95 Da), respectively. In the nested case-control study, the result of Western blot demonstrated that protein expression of ITIH4 in the group with followup ACEs was significantly lower than the matched group without followup ACEs (P = 0.027). Conclusion. ITIH4 might be a new potential biomarker of CHD "toxin syndrome" in TCM, indicating the potential role in early identifying high-risk CHD patients in stable period.

Jacalin bound plasma O-glycoproteome and reduced sialylation of alpha 2-HS glycoprotein (A2HSG) in rheumatoid arthritis patients

Glycosylation studies of plasma proteins can reveal information about the onset and progression of diseases, where in the glycan biosynthetic pathways are disturbed as in rheumatoid arthritis (RA). The present study was focused on analysis of O-linked glycoproteins of plasma in RA patients. Two dimensional gel electrophoresis of jacalin bound plasma of RA patients revealed a number of differentially expressed protein spots as compared to healthy controls. Eighteen protein spots were found to have statistically significant (p<0.05) difference in their expression level from four sets of gels and were identified by MALDI-TOF MS. Most of the identified proteins were predicted to be O-glycosylated proteins by Net-O-Gly 3.1 algorithm. Among these the alpha 2HS glycoprotein (A2HSG) was found to be down regulated whereas inter alpha trypsin inhibitor H4 (ITIH4) was up regulated and this was validated by Western blotting. The glycosylation studies showed the reduced N-linked sialylation of A2HSG in RA patients. Altered glycoprotein expression and functional as well as structural studies of glycans might help in the diagnosis of RA and understanding the disease pathogenesis.

Activity-dependent neuroprotector homeobox protein: A candidate protein identified in serum as diagnostic biomarker for Alzheimer's disease

Alzheimer's disease (AD) is the most common cause of dementia of late life. To enhance our understanding of AD proteome, the serum proteins were analyzed using two-dimensional gel electrophoresis (2DE) combined with nano-high performance liquid chromatography electrospray ionization tandem mass spectrometry (nano-HPLC-ESI-MS/MS) followed by peptide fragmentation patterning. In this study, six protein spots with differential expression were identified. Five up-regulated proteins were identified as actin, apolipoprotein A-IV (Apo A-IV), inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), alpha-1-antitrypsin (AAT), and antithrombin-III (AT-III); one protein, activity-dependent neuroprotector homeobox protein (ADNP) was down-regulated in AD patients. These proteins with differential expression in the serum may serve as potential indicators of AD. Our results suggested that ADNP may play an important role in slowing the progression of clinical symptoms of AD.

Proteomic analysis reveals oxidative stress response as the main adaptative physiological mechanism in cows under different production systems

Three groups of cows representing three ranges of welfare in the production system were included in the study: two groups of Bruna dels Pirineus beef cattle maintained under different management systems (good and semiferal conditions) and a group of Alberes cows, a breed that lives in the mountains (hardest conditions). In order to identify new stress/welfare biomarkers, serum from Bruna cows living in both environments was subjected to DIGE labelling, two-dimensional electrophoresis and MALDI-MS or ion trap MS. Identification was achieved for 15 proteins, which mainly belonged to three biological functions, the oxidative stress pathway (glutathione peroxidase (GPx) and paraoxonase (PON-1)), the acute phase protein family (Heremans Schmid glycoprotein alpha2 (α2-HSG)) and the complement system. Biological validation included the Alberes breed. GPx and PON-1 were validated by an enzymatic assay and found to be higher and lower, respectively, in cows living in hard conditions. α2-HSG was validated by ELISA and found to be reduced in hard conditions. Other biomarkers of the redox status were also altered by living conditions: protein carbonyl content, superoxide dismutase (SOD) and glutathione reductase (GR). Our results show that changes in the redox system are the main adaptation of cows living in challenging environmental conditions.

Proteomic characterization by 2-DE in bovine serum and whey from healthy and mastitis affected farm animals

Acute phase proteins (APP) have been identified in whey and sera from healthy and mastitis cows through the proteomic analysis using two-dimensional electrophoresis (2-DE) coupled with Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Although normal and mastitis serum samples show relatively similar protein composition, marked differences in expression levels and patterns can be observed. Conversely, normal and mastitis whey showed a very different composition, likely due to extravasation of blood proteins to the mammary gland. Different isoforms from the most abundant protein in milk, casein, were detected in both normal and mastitis whey. Other proteins, such as lactotransferrin, were only detected in the inflamed animal samples. Immunoglobulins showed different patterns but not increased levels in the inflamed whey. Also, many cellular proteins in mastitis cow's whey, that were absent from healthy cow's milk. They are responsible for the great change in composition between normal and mastitis whey, especially those which exert a biological function related to immune defense. Data collected in this work are of interest for gaining information about physiological changes in protein patterns in different fluids and, the correspondent modifications as result of an acute phase process in farm. This article is part of a Special Issue entitled: Proteomics: The clinical link.

Proteomic analyses of host and pathogen responses during bovine mastitis

The pursuit of biomarkers for use as clinical screening tools, measures for early detection, disease monitoring, and as a means for assessing therapeutic responses has steadily evolved in human and veterinary medicine over the past two decades. Concurrently, advances in mass spectrometry have markedly expanded proteomic capabilities for biomarker discovery. While initial mass spectrometric biomarker discovery endeavors focused primarily on the detection of modulated proteins in human tissues and fluids, recent efforts have shifted to include proteomic analyses of biological samples from food animal species. Mastitis continues to garner attention in veterinary research due mainly to affiliated financial losses and food safety concerns over antimicrobial use, but also because there are only a limited number of efficacious mastitis treatment options. Accordingly, comparative proteomic analyses of bovine milk have emerged in recent years. Efforts to prevent agricultural-related food-borne illness have likewise fueled an interest in the proteomic evaluation of several prominent strains of bacteria, including common mastitis pathogens. The interest in establishing biomarkers of the host and pathogen responses during bovine mastitis stems largely from the need to better characterize mechanisms of the disease, to identify reliable biomarkers for use as measures of early detection and drug efficacy, and to uncover potentially novel targets for the development of alternative therapeutics. The following review focuses primarily on comparative proteomic analyses conducted on healthy versus mastitic bovine milk. However, a comparison of the host defense proteome of human and bovine milk and the proteomic analysis of common veterinary pathogens are likewise introduced.

Effects of different antimicrobial treatments on serum acute phase responses and leucocyte counts in pigs after a primary and a secondary challenge infection with Actinobacillus pleuropneumoniae

The susceptibility to an initial challenge and a re-challenge inoculation with Actinobacillus pleuropneumoniae was analysed in pigs that were treated with antimicrobials of different efficacies following the first exposure to A pleuropneumoniae. In brief, 30 nine-week-old specific pathogen-free pigs were allocated to five groups of six. After acclimatisation, four groups were inoculated with A pleuropneumoniae serotype 2. At the onset of clinical signs, three of the groups of pigs were treated with enrofloxacin, tetracycline or penicillin. A fourth group served as the inoculated control and the fifth group as a control group that had not been inoculated. On day 28, all five groups were re-challenged with the same strain of A pleuropneumoniae serotype 2 as had been used in the first inoculation. No treatments were carried out at this time. The acute phase responses and differential leucocyte counts were monitored in detail after both inoculations. Leucocytosis and acute phase responses in the forms of serum amyloid A, pig-major acute phase protein and haptoglobin were recorded in all of the inoculated groups after the onset of clinical signs following the first inoculation. A porcine mannan-binding lectin-A response was less evident in the pigs. Acute phase responses resembling those of the first inoculation were observed in the pigs that had not previously been inoculated and in the pigs treated with enrofloxacin. Acute phase responses were not recorded in the other three groups, where the pigs had seroconverted to A pleuropneumoniae serotype 2 following the first inoculation.

Surface shaving as a versatile tool to profile global interactions between human serum proteins and the Staphylococcus aureus cell surface

The human commensal bacterium Staphylococcus aureus is renowned as a causative agent of severe invasive diseases. Upon entering the bloodstream, S. aureus can infect almost every tissue and organ system in the human body. To withstand insults from the immune system upon invasion, several immune-evasive mechanisms have evolved in S. aureus, such as complement inhibition by secreted proteins and IgG-binding by surface-exposed protein A. While it is generally accepted that S. aureus cells bind a range of host factors for various purposes, no global analyses to profile staphylococcal host factor binding have so far been performed. Therefore, we explored the possibility to profile the binding of human serum proteins to S. aureus cells by "surface shaving" with trypsin and subsequent MS analysis of liberated peptides. This resulted in the identification of several components of the complement system, the platelet factor 4 and the isoform 1 of the inter-α-trypsin inhibitor heavy chain H4 on the staphylococcal cell surface. We conclude that surface shaving is a versatile tool to profile global interactions between human serum proteins and the S. aureus cell surface.

Proteomic identification of serum peptides predicting subsequent spontaneous preterm birth

OBJECTIVE

We sought to identify serum markers of subsequent spontaneous preterm birth (SPTB) in asymptomatic women prior to labor.

STUDY DESIGN

Serum proteomics was applied to sera from 80 pregnant women sampled at 24 weeks and an additional 80 pregnant women sampled at 28 weeks. Half had uncomplicated pregnancies and half had SPTB.

RESULTS

Three specific peptides arising from inter-alpha-trypsin inhibitor heavy chain 4 protein were significantly reduced in women at 24 and 28 weeks having subsequent SPTB. The most discriminating peptide had a sensitivity of 65.0% and specificity of 82.5%; odds ratio, 8.8; and 95% confidence interval, 3.1-24.8. A combination of the 3 new biomarkers and 6 previously studied biomarkers increased sensitivity to 86.5%, with a specificity of 80.6% at 28 weeks.

CONCLUSION

Three novel serum markers of SPTB have been identified using serum proteomics. Using a combination of these new markers with additional markers, women at risk of SPTB can be identified weeks prior to SPTB.