Identification of novel molecular candidates for acute liver failure in plasma of BALB/c murine model

Phosphatidylethanolamine-binding protein 4 deficiency exacerbates carbon tetrachloride-induced liver fibrosis by regulating the NF-κB signaling pathway

Liver fibrosis is a pathological process which can progress to hepatocirrhosis, even hepatocellular carcinoma. Phosphatidylethanolamine-binding protein 4 (PEBP4) is a secreted protein involved in regulating many molecular pathways, whereas its roles in diseases including hepatic fibrosis remain undefined. The nuclear factor-κappa B (NF-κB) signaling pathway has been found to be involved in the development of liver fibrosis. In this study, we generated a hepatocyte-conditional knockout (CKO) mouse model of PEBP4, and explored the potential functions of PEBP4 on liver fibrosis and the NF-κB signaling pathway in a mouse model of carbon tetrachloride (CCl4)-induced liver fibrosis. We demonstrated that PEBP4 CKO aggravated CCl4-triggered liver fibrosis, as evidenced by altered histopathology, an increase in the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and hydroxyproline (HYP) levels, and more collagen deposition, as well as by enhanced expression of fibrotic markers including α-smooth muscle actin (α-SMA), collagen I and collagen III. Mechanistically, PEBP4 deficiency activated the NF-κB signaling pathway, as indicated by increased phosphorylation of NF-κB p65 and inhibitor protein κB inhibitor-α (IκB-α), and nuclear NF-κB p65 expression in the fibrotic liver. Notably, the NF-κB inhibitor pyrrolidine dithiocarbamate (PDTC) partially blocked the activation of the NF-κB pathway, and reversed the pro-fibrotic effect of PEBP4 deletion in CCl4-treated mice. Together, these results suggest that PEBP4 deficiency results in aggravation of liver fibrosis and activation of the NF-κB signaling pathway, supporting a novel concept that PEBP4 is a crucial player in hepatic fibrosis, but also might be a negative regulator of the NF-κB signaling in liver fibrosis.

Plasma proteomics reveals crosstalk between lipid metabolism and immunity in dairy cows receiving essential fatty acids and conjugated linoleic acid

Essential fatty acids (EFA) and conjugated linoleic acids (CLA) are unsaturated fatty acids with immune-modulatory effects, yet their synergistic effect is poorly understood in dairy cows. This study aimed at identifying differentially abundant proteins (DAP) and their associated pathways in dairy cows supplied with a combination of EFA and CLA during the transition from antepartum (AP) to early postpartum (PP). Sixteen Holstein cows were abomasally infused with coconut oil as a control (CTRL) or a mixture of EFA (linseed + safflower oil) and CLA (Lutalin, BASF) (EFA + CLA) from − 63 to + 63 days relative to parturition. Label-free quantitative proteomics was performed on plasma samples collected at days − 21, + 1, + 28, and + 63. During the transition time, DAP, consisting of a cluster of apolipoproteins (APO), including APOE, APOH, and APOB, along with a cluster of immune-related proteins, were related to complement and coagulation cascades, inflammatory response, and cholesterol metabolism. In response to EFA + CLA, specific APO comprising APOC3, APOA1, APOA4, and APOC4 were increased in a time-dependent manner; they were linked to triglyceride-enriched lipoprotein metabolisms and immune function. Altogether, these results provide new insights into metabolic and immune adaptation and crosstalk between them in transition dairy cows divergent in EFA + CLA status.

Metabolomic profiles of breath odor compounds for prognostic prediction in patients with acute-on-chronic liver failure: A pilot study

AIM

The aim of this study was to use a metabonomics approach to identify potential biomarkers of exhaled breath condensate (EBC) for predicting the prognosis of acute-on-chronic liver failure (ACLF).

METHODS

Using liquid chromatography mass spectrometry, EBC metabolites of ACLF patients surviving without liver transplantation (n = 57) and those with worse outcomes (n = 45), and controls (n = 15) were profiled from a specialized liver disease center in Beijing. The metabolites were used to identify candidate biomarkers, and the predicted performance of potential biomarkers was tested.

RESULTS

Forty-one metabolites, involving glycerophospholipid metabolism, sphingolipid metabolism, arachidonic acid metabolism, and amino acid metabolism, as candidate biomarkers for discriminating the different outcomes of ACLF were selected. A prognostic model was constructed by a panel of four metabolites including phosphatidylinositol [20:4(5Z,8Z,11Z,14Z)/13:0], phosphatidyl ethanolamine (12:0/22:0), L-metanephrine and ethylbenzene, which could predict the worse prognosis in ACLF patients with sensitivity (84.4%) and specificity (89.5%) (area under the receiver operating characteristic curve [AUC] = 0.859, 95% confidence interval [CI] = 0.787-0.931). Compared with Model for End-Stage Liver Disease (MELD) score (AUC = 0.639, 95% CI = 0.526-0.753) and MELD-sodium (MELD-Na) score (AUC = 0.692, 95% CI = 0.582-0.803), EBC-associated metabolite signature model could better predict worse outcomes in patients with ACLF (p < 0.05). Using the MELD-Na score and EBC metabolite signatures, a decision tree model was built for predicting the prognosis of ACLF identified on logistic regression analyses (AUC = 0.906, 95% CI = 0.846-0.965).

CONCLUSION

EBC metabolic signatures show promise as potential biomarkers for predicting worse prognosis of ACLF.

Plasminogen as a prognostic biomarker for HBV-related acute-on-chronic liver failure

BACKGROUNDHBV-related acute-on-chronic liver failure (HBV-ACLF) is hallmarked by high short-term mortality rates, calling for accurate prognostic biomarkers for initial risk stratification.METHODSThree tandem mass tag-labeled (TMT-labeled) quantitative proteomic studies were performed on 10 patients with HBV-related acute hepatic decompensation and on 20 patients with HBV-ACLF. Candidate biomarkers were preliminarily verified in a cross-sectional cohort (n = 144) and further confirmed in 2 prospective cohorts (n = 207 and n = 148).RESULTSPlasminogen, a potential prognostic biomarker for HBV-ACLF, was identified by TMT quantitative proteomics and preliminarily verified in the cross-sectional cohort. Further validation with a prospective cohort (n = 207) showed that plasminogen levels at admission were significantly lower (P < 0.001) in HBV-ACLF nonsurvivors than in survivors. The cumulative survival duration of patients with high plasminogen levels was significantly longer (P < 0.001) than that of patients with low plasminogen levels. During hospitalization, plasminogen levels significantly decreased (P = 0.008) in the deterioration group but significantly increased (P < 0.001) in the improvement group. Additionally, plasminogen levels gradually increased in survivors but gradually decreased in nonsurvivors. The P5 score, a prognostic panel incorporating plasminogen levels, hepatic encephalopathy occurrence, age, international normalized ratio (INR), and total bilirubin, was significantly superior to the Child-Pugh, Model for End-stage Liver Disease (MELD), Chronic Liver Failure Consortium ACLF (CLIF-C ACLF), Chinese Group on the Study of Severe Hepatitis B (COSSH), and HINT (a prognostic score based on hepatic encephalopathy occurrence, INR, neutrophil count, and thyroid-stimulating hormone) scores (all P < 0.05). The performances of the plasminogen level and P5 score were validated in a second multicenter, prospective cohort (n = 148).CONCLUSIONSPlasminogen is a promising prognostic biomarker for HBV-ACLF, and sequential plasminogen measurements could profile the clinical course of HBV-ACLF. P5 is a high-performance prognostic score for HBV-ACLF.FUNDINGThe National Key Research and Development Program (2017YFC1200204); the National Natural Science Foundation of China (81400589, 81600497); the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (81121002); the Chinese High-Tech Research and Development Programs (2012AA020204); the National S&T Major Project (2012ZX10002004); and the Zhejiang Provincial Medicine and Health Science and Technology Project (2016147735).

Discovery of a Potential Plasma Protein Biomarker Panel for Acute-on-Chronic Liver Failure Induced by Hepatitis B Virus

Hepatitis B virus (HBV)-associated acute-on-chronic liver failure (HBV-ACLF), characterized by an acute deterioration of liver function in the patients with chronic hepatitis B (CHB), is lack of predicting biomarkers for prognosis. Plasma is an ideal sample for biomarker discovery due to inexpensive and minimally invasive sampling and good reproducibility. In this study, immuno-depletion of high-abundance plasma proteins followed by iTRAQ-based quantitative proteomic approach was employed to analyze plasma samples from 20 healthy control people, 20 CHB patients and 20 HBV-ACLF patients, respectively. As a result, a total of 427 proteins were identified from these samples, and 42 proteins were differentially expressed in HBV-ACLF patients as compared to both CHB patients and healthy controls. According to bioinformatics analysis results, 6 proteins related to immune response (MMR), inflammatory response (OPN, HPX), blood coagulation (ATIII) and lipid metabolism (APO-CII, GP73) were selected as biomarker candidates. Further ELISA analysis confirmed the significant up-regulation of GP73, MMR, OPN and down-regulation of ATIII, HPX, APO-CII in HBV-ACLF plasma samples (p < 0.01). Moreover, receiver operating characteristic (ROC) curve analysis revealed high diagnostic value of these candidates in assessing HBV-ACLF. In conclusion, present quantitative proteomic study identified 6 novel HBV-ACLF biomarker candidates and might provide fundamental information for development of HBV-ACLF biomarker.

Regucalcin expression in bovine tissues and its regulation by sex steroid hormones in accessory sex glands

Regucalcin (RGN) is a mammalian Ca2+-binding protein that plays an important role in intracellular Ca2+ homeostasis. Recently, RGN has been identified as a target gene for sex steroid hormones in the prostate glands and testis of rats and humans, but no studies have focused on RGN expression in bovine tissues. Thus, in the present study, we examined RGN mRNA and protein expression in the different tissues and organs of veal calves and beef cattle. Moreover, we investigated whether RGN expression is controlled through sex steroid hormones in bovine target tissues, namely the bulbo-urethral and prostate glands and the testis. Sex steroid hormones are still illegally used in bovine husbandry to increase muscle mass. The screening of the regulation and function of anabolic sex steroids via modified gene expression levels in various tissues represents a new approach for the detection of illicit drug treatments. Herein, we used quantitative PCR, western blot and immunohistochemistry analyses to demonstrate RGN mRNA and protein expression in bovine tissues. In addition, estrogen administration down-regulated RGN gene expression in the accessory sex glands of veal calves and beef cattle, while androgen treatment reduced RGN gene expression only in the testis. The confirmation of the regulation of RGN gene expression through sex steroid hormones might facilitate the potential detection of hormone abuse in bovine husbandry. Particularly, the specific response in the testis suggests that this tissue is ideal for the detection of illicit androgen administration in veal calves and beef cattle.

The diverse roles of calcium-binding protein regucalcin in cell biology: from tissue expression and signalling to disease

Regucalcin (RGN) is a calcium (Ca(2+))-binding protein widely expressed in vertebrate and invertebrate species, which is also known as senescence marker protein 30, due to its molecular weight (33 kDa) and a characteristically diminished expression with the aging process. RGN regulates intracellular Ca(2+) homeostasis and the activity of several proteins involved in intracellular signalling pathways, namely, kinases, phosphatases, phosphodiesterase, nitric oxide synthase and proteases, which highlights its importance in cell biology. In addition, RGN has cytoprotective effects reducing intracellular levels of oxidative stress, also playing a role in the control of cell survival and apoptosis. Multiple factors have been identified regulating the cell levels of RGN transcripts and protein, and an altered expression pattern of this interesting protein has been found in cases of reproductive disorders, neurodegenerative diseases and cancer. Moreover, RGN is a serum-secreted protein, and its levels have been correlated with the stage of disease, which strongly suggests the usefulness of this protein as a potential biomarker for monitoring disease onset and progression. The present review aims to discuss the available information concerning RGN expression and function in distinct cell types and tissues, integrating cellular and molecular mechanisms in the context of normal and pathological conditions. Insight into the cellular actions of RGN will be a key step towards deepening the knowledge of the biology of several human diseases.

Proteomics-based investigations of animal models of disease

Cells contain a large yet, constant genome, which contains all the coding information necessary to sustain cellular physiology. However, proteins are the end products of genes, and hence dictate the phenotype of cells and tissues. Therefore, proteomics can provide key information for the elucidation of physiological and pathophysiological mechanisms by identifying the protein profile from cells and tissues. The relatively novel techniques used for the study of proteomics thus have the potential to improve diagnostic, prognostic, as well as therapeutic avenues. In this review, we first discuss the benefits of animal models over the use of human samples for the proteomic analysis of human disease. Next, we aim to demonstrate the potential of proteomics in the elucidation of disease mechanisms that may not be possible by other conventional technologies. Following this, we describe the use of proteomics for the analysis of PTM and protein interactions in animal models and their relevance to the study of human disease. Finally, we discuss the development of clinical biomarkers for the early diagnosis of disease via proteomic analysis of animal models. We also discuss the development of standard proteomes and relate how this data will benefit future proteomic research. A comprehensive review of all animal models used in conjunction with proteomics is beyond the scope of this manuscript. Therefore, we aimed to cover a large breadth of topics, which together, demonstrate the potential of proteomics as a powerful tool in biomedical research.

[Gene expression profiling in the first twelve weeks of treatment in chronic hepatitis C patients]

INTRODUCTION

Gene expression profiling in the first weeks of treatment of patients with chronic hepatitis C may contribute to better evaluate the response to interferon-based therapy. The objective of this study was to evaluate the gene expression profiles of early responders and non-responders before, and after 12 weeks of treatment with peginterferon alfa and ribavirin.

METHODS

Gene expression profiles were analysed in 12 patients with chronic hepatitis C, and scheduled for treatment with peginterferon alpha and ribavirin.

RESULTS

Of the 12 patients studied, six showed a complete early virological response, while six failed to control viremia. In early responders, treatment with peginterferon and ribavirin induced an increased expression of a larger number of interferon-induced genes (ISG15, IFI6, IFI44L, IFI27, MX1, OASL, IRF7, IFIT3, IFITM1, EIF2AK2, HERC5 and APOBEC3) than in non-responders (ISG15, IFI44L, IFI27, IRF7, USP18) in the first twelve weeks of treatment (P<0.05). In both groups, there were changes in the levels of certain genes poorly described in the treatment of hepatitis C so far.

CONCLUSIONS

The gene expression profiles described in this study provide a new insight to understanding the pathogenesis of the disease and treatment effect. The more marked effect of the treatment on the expression of interferon-response genes observed in early responders could explain their better control of viral load.

Regucalcin is broadly expressed in male reproductive tissues and is a new androgen-target gene in mammalian testis

Regucalcin (RGN) is a calcium (Ca2+)-binding protein which regulates intracellular Ca2+homeostasis by modulating the activity of enzymes regulating Ca2+concentration and enhancing Ca2+-pumping activity. Several studies have described the pivotal role of proper Ca2+homeostasis regulation to spermatogenesis and male fertility. Recently,RGNwas identified as a sex steroid-regulated gene in prostate and breast; however, a possible role of RGN in spermatogenesis has not been examined. In this study, the expression and localization of RGN in rat and human testis, and other rat reproductive tissues was analyzed. Moreover, we studied whether RGN protein was present in seminiferous tubule fluid (STF). Finally, we examined the effect of 5α-dihydrotestosterone (DHT) on the expression ofRgnmRNA in rat seminiferous tubules (SeT) culturedex vivo. The results presented in this study show that RGN is expressed in Leydig and Sertoli cells, as well as in all types of germ cells of both rat and human testis. RGN is also expressed in rat prostate, epididymis, and seminal vesicles. Moreover, RGN protein is present in rat STF. The results also demonstrate thatRgnexpression is age dependent in rat testis, and is upregulated by the non-aromatizable androgen DHT in rat SeT culturedex vivo. Taken together, these findings indicate thatRgnis a novel androgen-target gene in rat testis and that it may have a role in male reproductive function, particularly in the control of spermatogenesis.

Serum UPLC-MS/MS metabolic profiling in an experimental model for acute-liver injury reveals potential biomarkers for hepatotoxicity

A key interest in clinical diagnosis and pharmaceutical industry is to have a repertoire of noninvasive biomarkers to-individually or in combination-be able to infer or predict the degree of liver injury caused by pathological conditions or drugs. Metabolomics-a comprehensive study of global metabolites-has become a highly sensitive and powerful tool for biomarker discovery thanks to recent technological advances. An ultra-performance liquid chromatography/time-of-flight tandem mass spectrometry (UPLC/TOF MS/MS)-based metabolomics approach was employed to investigate sera from galactosamine-treated rats to find potential biomarkers for acute liver injury. Hepatic damage was quantified by determining serum transaminase activity and in situ liver histological lesions. Principal component analysis in combination with coefficient of correlation analysis was used for biomarker selection and identification. According to the data, serum levels of several metabolites including glucose, amino acids, and membrane lipids were significantly modified, some of them showing a high correlation with the degree of liver damage determined by histological examination of the livers. In conclusion, this study supports that UPLC-MS/MS based serum metabolomics in experimental animal models could be a powerful approach to search for biomarkers for drug- or disease-induced liver injury.

α-2-HS-glycoprotein is a potential marker predicting hepatitis B e antigen seroconversion in patients with chronic hepatitis B during treatment with pegylated interferon alpha-2b

The efficacy of interferon (IFN) is limited in about 1/3 of patients with chronic hepatitis B (CHB). We used two-dimensional electrophoresis (2-DE)-based proteomic strategies to identify potential serum markers predicting hepatitis B e antigen (HBeAg) seroconversion in these patients during IFN therapy. Two groups of patients were enrolled: training and validation. In the training group, 2-DE experiments and subsequent identification of altered levels of proteins showed that α-2-HS-glycoprotein, leucine-rich α-2-glycoprotein, and haptoglobin were significantly upregulated as compared with baseline levels in the HBeAg seroconversion group, whereas apolipoprotein C-III precursor, leucine-rich α-2-glycoprotein, and α-albumin were downregulated in the non-seroconversion group. For patients with HBeAg seroconversion in the training group, Western blot analyses showed that α-2-HS-glycoprotein levels in 75% of patients were significantly upregulated at the end of the treatment as compared with baseline levels. Subsequent experiments in the validation group showed that α-2-HS-glycoprotein levels were significantly increased at week 4 in 83.33% of patients in the HBeAg seroconversion group. Dynamic changes in the serum level of α-2-HS-glycoprotein may be a potential early marker for predicting HBeAg seroconversion during IFN treatment for CHB.

Comparative serum proteomic analysis of patients with acute-on-chronic liver failure: alpha-1-acid glycoprotein maybe a candidate marker for prognosis of hepatitis B virus infection

The acute-on-chronic liver failure (AoCLF) caused by hepatitis B virus (HBV) infection remains to be a challenge in clinics with a high mortality rate in China, and it is important to identify biomarkers to foresee the prognosis of patients with HBV. The current study analysed serum proteome changes of acute-on-chronic liver failure as a result of acute exacerbation of chronic hepatitis B infection. Serum samples were collected from normal subjects (NS, n = 8), patients with chronic hepatitis B (CHB, n = 12) and patients with AoCLF (n = 12). After removal of albumin/IgG and ultramembrane centrifugation, serum proteins were separated by two-dimensional gel electrophoresis. Differentially expressed spots were identified by matrix-associated laser desorption ionization time-of-flight tandem mass spectrometry. Through the removal of albumin/IgG and ultramembrane centrifugation, the well-resolved and reproducible two-dimensional gel electrophoresis (2-DE) profiles were obtained. A total of 23 proteins were identified on 2-DE profiles by their differential expression between the three cohorts. Mass spectrometry analysis resulted in the identification of 12 proteins unambiguously. Western blot analysis confirmed the proteomics results that the α1-acid glycoprotein (α1-AGP) levels decrease significantly in plasma of patients with AoCLF, but somewhat decreased in patients with chronic HBV. Further α1-AGP levels in bulk serum samples were measured by immune turbidimetry including normal subjects group (n = 25), acute hepatitis group (n = 36), chronic hepatitis group (n = 52) and AoCLF group (n = 48), the level of α1-AGP in AoCLF groups sharply decrease than other groups. Our study shows that α1-AGP may be a potential plasma biomarker for AoCLF diagnosis because of acute exacerbation of chronic hepatitis B infection.

Peroxiredoxin 2: a potential biomarker for early diagnosis of hepatitis B virus related liver fibrosis identified by proteomic analysis of the plasma

Background

Liver fibrosis is a middle stage in the course of chronic Hepatitis B virus (HBV) infection, which will develop into cirrhosis and eventually hepatocellular carcinoma (HCC) if not treated at the early stage. Considering the limitations and patients' reluctance to undergo liver biopsy, a reliable, noninvasive diagnostic system to predict and assess treatment and prognosis of liver fibrosis is needed. The aim of this study was to identify biomarkers for early diagnosis of HBV related liver fibrosis.

Method

Plasma samples from 7 healthy volunteers and 27 HBV infected patients with different stages of fibrosis were selected for 2-DIGE proteomic screening. One-way ANOVA analysis was used to assess differences in protein expression among all groups. The alteration was further confirmed by western blotting. Plasma levels of 25 serological variables in 42 healthy volunteers and 68 patients were measured to establish a decision tree for the detection of various stages fibrosis.

Result

The up-regulated proteins along with fibrosis progress included fibrinogen, collagen, macroglobulin, hemopexin, antitrypsin, prealbumin and thioredoxin peroxidase. The down-regulated proteins included haptoglobin, serotransferrin, CD5 antigen like protein, clusterin, apolipoprotein and leucine-rich alpha-2-glycoprotein. For the discrimination of milder stage fibrosis, the area under curve for Prx II was the highest. Four variables (PT, Pre, HA and Prx II) were selected from the 25 variables to construct the decision tree. In a training group, the correct prediction percentage for normal control, milder fibrosis, significant fibrosis and early cirrhosis was 100%, 88.9%, 95.2% and 100%, respectively, with an overall correct percent of 95.9%.

Conclusion

This study showed that 2-D DIGE-based proteomic analysis of the plasma was helpful in screening for new plasma biomarkers for liver disease. The significant up-expression of Prx II could be used in the early diagnosis of HBV related liver fibrosis.

Serum peptide profiles during progression of chronic hepatitis B virus infection to liver failure

Chronic hepatitis B virus (HBV)-infected patients with liver failure have a poor prognosis, and no satisfactory biomarkers are available for diagnosis before the end-stage. We explored serum peptide profiling for diagnosis and prediction of progression to liver failure in HBV-infected patients. Serum samples (164) from healthy subjects (n = 20), or subjects with chronic hepatitis B without cirrhosis and liver failure [chronic hepatitis B subjects without cirrhosis and liver failure (CHB); n = 33], with compensated liver cirrhosis (compensated liver cirrhosis (LC); n = 35), with acute-on-chronic liver failure [acute-on-chronic liver failure (ACLF); n = 38] or with chronic liver failure [chronic liver failure (CLF), n = 38] were applied to ClinProt magnetic beads, and bound peptides/proteins were analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Our classification diagnostic models of liver disease were generated based on the Genetic Algorithm (GA) and Quick Classifier Algorithm (QC). Differentially expressed peptides were found among all test groups, with patterns of difference that readily distinguished between healthy and various HBV-associated liver disease samples. The model generated seven characteristic peptide peaks at 4053 m/z, 3506 m/z, 4963 m/z, 9289 m/z, 2628 m/z, 3193 m/z and 6432 m/z, giving overall predictive capability of 54.27%. Two-way comparisons of LC, ACLF or CLF vs CHB had predictive capabilities of 79.8%, 91.41% and 97.99%, respectively. Comparisons of ACLF or CLF vs LC were predictive at 87.72% and 82.18%, respectively and ACLF vs CLF was predictive at 75.05%. These classification diagnostic models generated by different peptide peaks were further validated in blinded tests with 67-100% accuracy. Serum peptide patterns vary during progression of chronic HBV infection to liver failure and may be used to distinguish different stages of the disease.

Proteome responses to stable hepatitis B virus transfection and following interferon alpha treatment in human liver cell line HepG2

Hepatitis B virus (HBV) infection is a worldwide health problem and may develop to liver fibrosis, cirrhosis, and even hepatocellular carcinoma. To investigate the global proteome responses of liver-derived cells to HBV infection and IFNalpha treatment, 2-DE and MS-based analysis were performed to compare the proteome changes between HBV stably transfected cell line HepG2.2.15 and its parental cell line HepG2, as well as HepG2.2.15 before and after IFNalpha treatment (5000 IU/mL for 72 h). Compared to HepG2, 12 of 18 down-regulated and 27 of 32 up-regulated proteins were identified in HepG2.2.15. After IFNalpha treatment, 6 of 7 down-regulated and 11 of 14 up-regulated proteins were identified. Differentially expressed proteins caused by HBV infection were involved with cytoskeletal matrix, heat shock stress, kinases/signal transduction, protease/proteasome components, etc. Prohibitin showed a dose-dependent up-regulation during IFNalpha treatment and might play a potent role in anti-HBV activities of IFNalpha by enhancing the crossbinding p53 expression to achieve the apoptosis of HBV infected liver cells. Down-regulation of interferon-stimulated gene 15 (ISG15) in HepG2.2.15 and recovery by IFNalpha suggested its relationship with IFNalpha's anti-HBV effect.

A study on the differential protein profiles in liver cells of heat stress rats with and without turpentine treatment

BACKGROUND

Heat stress (HS) and related illnesses are a major concern in military, sports, and fire brigadiers. HS results in physiologic responses of increased temperature, heart rate and sweating. In heat stroke, inflammatory response plays an important role and it is evidenced that turpentine (T) induced circulating inflammatory cytokines reduced survival rate and duration at 42 degrees C. Here we report the alteration in the protein expression in liver cells upon HS with and without T treatment using two dimensional gel electrophoresis (2-DE), tryptic in-gel digestion and MALDI-TOF-MS/MS approaches.

RESULTS

The effects of HS and T treatments alone and a combined treatments (T+HS) was performed in Wistar rat models. Proteomic analysis of liver in the HS and T+HS groups were analyzed compared to liver profiles of resting control and T treated groups. The study revealed a total of 25 and 29 differentially expressed proteins in the HS and T+HS groups respectively compared to resting control group. Fourteen proteins showed altered expression upon T treatment compared to resting control group. Proteins that are involved in metabolic and signal transduction pathways, defense, redox regulation, and cytoskeletal restructuring functions were identified. The altered expression of proteins reflected in 2D gels were corroborated by quantitative real time RT-PCR analysis of 8 protein coding genes representing metabolic and regulatory pathways for their expression and normalized with the house keeping gene beta-actin.

CONCLUSION

The present study has identified a number of differentially expressed proteins in the liver cells of rats subjected to T, HS and T+HS treatments. Most of these proteins are implicated in cell metabolism, as well as adaptive response to incurred oxidative stress and tissue damage due to T+HS and HS effects.

Senescence marker protein 30 in acute liver failure: validation of a mass spectrometry proteomics assay

BACKGROUND

Our previous proteomic study showed that the senescence marker protein (SMP30) is selectively present in the plasma of a murine model of acute liver failure (ALF). The aim of this study was to validate this SMP30 expression in the plasma and liver tissues of mice and humans with ALF.

METHODS

After the proteomic analysis of plasma from a murine model of D-galactosamine/lipopolysaccharide (GalN/LPS)-induced ALF by two-dimensional electrophoresis (2-DE) and mass spectrometry, the expression levels of SMP30 in the plasma and liver tissues were validated by western blot and RT-PCR analyses. These results were then confirmed in plasma samples from humans.

RESULTS

These data validate the results of 2-DE, and western blot showed that SMP30 protein levels were only elevated in the plasma of ALF mice. Further analysis revealed that GalN/LPS induced the downregulation of SMP30 protein levels in liver tissues (by approximately 25% and 16% in the GalN/LPS-treated mice and in the treated mice that survived, respectively; P < 0.01). Hepatic SMP30 mRNA levels decreased by about 90% only in the mice that survived the GalN/LPS treatment. Importantly, plasma obtained from patients with ALF also contained higher levels of SMP30, about (3.65 +/- 0.34) times those observed in healthy volunteers.

CONCLUSION

This study shows that SMP30 is not only a potential biomarker for the diagnosis and even prognosis of ALF. It also plays a very important role in a self-protective mechanism in survival and participates in the pathophysiological processes of ALF.

Proteomic analysis of the pathophysiological process involved in the antisnake venom effect of Mucuna pruriens extract

Previously, we reported the antisnake venom properties of a Mucuna pruriens seed extract (MPE) and tested its in vivo efficacy against Echis carinatus venom (EV) in short- (1 injection) and long-term (three weekly injections) treatments. The aim of the present study was to investigate plasma proteome changes associated with MPE treatments and identify proteins responsible for survival of envenomated mice (CHALLENGED mice). Six treatment groups were studied. Three control groups: one saline, one short-term and one long-term MPE treatment. One group received EV alone. Two test groups received EV with either a short-term or long-term MPE treatment (CHALLENGED mice). The plasma from each group was analysed by 2-DE/MALDI-TOF MS. The most significant changes with treatment were: albumin, haptoglobin, fibrinogen, serum amyloid A and serum amyloid P. Most of these changes were explained by EV effects on coagulation, inflammation and haemolysis. However, MPE treatments prevented the EV-induced elevation in HPT. Consequently, HPT levels were similar to controls in the plasma of CHALLENGED mice. The plasma of CHALLENGED mice showed substantial proteomic modifications. This suggests the mechanism of MPE protection involves the activation of counterbalancing processes to compensate for the imbalances caused by EV.