Evaluation of Serum and Gene Expression of Galectin-4, Interleukin-27, and Complement-7 in Hepatitis C Virus-Infected Egyptian Patients.

BACKGROUND: Hepatitis C virus (HCV) is considered a major global public health problem. Recently, there are great advances in HCV therapy, but there are some limitations that are creating an urgent need for assessment of some cytokines that have a potent antiviral effect in the immune system and anti-inflammatory effects to provide a potential novel immunotherapeutic target in HCV infection. OBJECTIVE: This study was directed to assess the serum levels and gene expression levels of Galectin-4 (LEG4), Interleukin-27 (IL-27), and Complement-7 (C-7) and their correlation with the viral load in HCV infection. Subjects and Methods. This work was conducted on 80 subjects, Group 1 (n = 40) early detected HCV patients and Group 2 (n = 40) healthy controls. LEG4, IL-27, and C-7 were assessed at the protein levels by ELISA, and their gene expression was assessed by RT-qPCR. The viral load was measured by PCR. RESULTS: There were significant elevations in the mean levels of gene expression and serum levels of all studied parameters LEG4, IL-27, and C-7 in the HCV group compared to the control group. Significant negative correlations between the viral load and each of the serum proteins and gene expressions of both LEG4 and IL-27 in HCV patients were found. The gene expression levels of LEG4, IL-27, and C-7 were positively correlated with their corresponding serum proteins in HCV patients. CONCLUSION: LEG4 and IL-27 showed significant negative correlations with the viral load, which could be an immune response to the control of the extent of hepatic inflammation, thus creating a potential novel immunotherapeutic approach in HCV infection for further studies or therapeutic clinical trials.

Factor trefoil-3 y galectina-4 como nuevos candidatos para biomarcadores pronósticos en infarto de miocardio con elevación del segmento ST / Trefoil factor-3 and galectin-4 as new candidates for prognostic biomarkers in ST-segment elevation myocardial infarction

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In search of causal pathways in diabetes: a study using proteomics and genotyping data from a cross-sectional study.

AIMS/HYPOTHESIS: The pathogenesis of type 2 diabetes is not fully understood. We investigated whether circulating levels of preselected proteins were associated with the outcome 'diabetes' and whether these associations were causal. METHODS: In 2467 individuals of the population-based, cross-sectional EpiHealth study (45-75 years, 50% women), 249 plasma proteins were analysed by the proximity extension assay technique. DNA was genotyped using the Illumina HumanCoreExome-12 v1.0 BeadChip. Diabetes was defined as taking glucose-lowering treatment or having a fasting plasma glucose of ≥7.0 mmol/l. The associations between proteins and diabetes were assessed using logistic regression. To investigate causal relationships between proteins and diabetes, a bidirectional two-sample Mendelian randomisation was performed based on large, genome-wide association studies belonging to the DIAGRAM and MAGIC consortia, and a genome-wide association study in the EpiHealth study. RESULTS: Twenty-six proteins were positively associated with diabetes, including cathepsin D, retinal dehydrogenase 1, α-L-iduronidase, hydroxyacid oxidase 1 and galectin-4 (top five findings). Three proteins, lipoprotein lipase, IGF-binding protein 2 and paraoxonase 3 (PON-3), were inversely associated with diabetes. Fourteen of the proteins are novel discoveries. The Mendelian randomisation study did not disclose any significant causal effects between the proteins and diabetes in either direction that were consistent with the relationships found between the protein levels and diabetes. CONCLUSIONS/INTERPRETATION: The 29 proteins associated with diabetes are involved in several physiological pathways, but given the power of the study no causal link was identified for those proteins tested in Mendelian randomisation. Therefore, the identified proteins are likely to be biomarkers for type 2 diabetes, rather than representing causal pathways.

The roles of galectin-3 and galectin-4 in the idiopatic Parkinson disease and its progression.

OBJECTIVES: Idiopathic Parkinson's Disease is a neurodegenerative disease caused by the loss of cells that secrete dopamine in the basal ganglia. Galectins are multipotent, evolutionarily conserved, cell surface glycoconjugated and crosslinked carbohydrate-binding proteins. The roles of these proteins in the diagnosis of the disease have been investigated. PATIENT AND METHODS: Patients who were diagnosed with idiopathic Parkinson's disease were classified as early (stage 1-2) and advanced stage (stage 3-5) according to the Hoehn-Yahr classification. In addition, voluntary cases without parkinson disease constituted the control group. Serum samples of consecutive Parkinson patients and age and gender matched healthy controls were used to measure serum galectin-3 and serum galectin-4 levels. The levels were compared between Parkinson's patients and control groups and early and advanced stage Parkinson's groups. RESULTS: Thirty age and gender-matched healthy controls and 60 parkinson patients were enrolled in the study. Serum galectin-3 levels were lower in controls compared with patients (892.9 (168.2-2416.3) vs. 2271.8 (375.9-9673.4), respectively, P < 0.01). Serum galectin-3 levels were related to Hoehn-Yahr stages and (r: 0.691, P < 0.001). The early stage group (20 patients) had lower serum galectin-4 levels compared with advanced stages (40 patients) (197.97 ± 46.42 vs. 334.263 ± 37, respectively, P < 0.01). Serum galectin-4 levels were also lower in controls compared with patients 185.1 (116.2-313.3) vs. 282.3 (156.9-984.8), respectively, P < 0.01. ROC analysis showed that serum galectin-3 and galectin-4 were statistically significant in the identification of Parkinson disease and advanced stages. The results were significant for galectin-3 (AUC: 0.89, SE: 0.034, P < 0.001 and CI: 0.823-0.958; P < 0.001) and for galectin-4 (AUC: 0.758, SE: 0.05, P < 0.001). CONCLUSION: Serum galectin-3 and galectin-4 may be potential noninvasive markers for the identification of Parkinson disease and advanced stages.

Protein biomarkers and coronary microvascular dilatation assessed by rubidium-82 PET in women with angina pectoris and no obstructive coronary artery disease.

BACKGROUND AND AIMS: While a plethora of biomarkers have been shown to be associated with coronary artery disease, studies assessing biomarkers in coronary microvascular dysfunction (CMD) are few. We investigated associations between cardiovascular protein biomarkers and non-endothelium dependent CMD assessed by positron emission tomography (PET). METHODS: In 97 women with angina pectoris and no significant obstructive coronary artery disease (<50% stenosis on invasive coronary angiography), CMD was defined as myocardial blood flow reserve (MBFR) < 2.5 by rubidium-82 PET. Blood samples were analyzed with a cardiovascular disease proteomic panel encompassing 92 biomarkers. The relation between MBFR and biomarkers was evaluated with age-adjusted regression analysis. RESULTS: Median age was 62 years (range 31-79), median MBFR was 2.7 (range 1.2-4.7) and 32% had non-endothelium dependent CMD (MBFR<2.5). Four biomarkers were significantly correlated with MBFR: Galectin-4 (Gal4, p = 0.008), growth differentiation factor 15 (GDF15, p = 0.026), tissue-type plasminogen activator (tPA, p = 0.030) and von Willebrand factor (vWF, p = 0.018), while 12 biomarkers showed a trend for correlation (0.05 ≤ p < 0.15). Of the 16 identified biomarkers, 10 are involved in pro-inflammatory pathways. CONCLUSIONS: In a panel of 92 cardiovascular protein biomarkers, 4 were significantly associated with non-endothelium dependent CMD in women: Gal4, GDF15, tPA and vWF, suggesting that inflammatory status and coagulation changes are associated with impaired microvascular dilatation. Further confirmatory studies are needed to corroborate these findings.

Proteomic Biomarkers for Incident Aortic Stenosis Requiring Valvular Replacement.

BACKGROUND: Aortic valve stenosis (AS) is the most common indication for cardiac valve surgery; untreated AS is linked to high mortality. The etiological background of AS is unknown. Previous human studies were typically based on case-control studies. Biomarkers identified in prospective studies could lead to novel mechanistic insights. METHODS: Within a large population survey with blood samples obtained at baseline, 334 patients were identified who later underwent surgery for AS (median age [interquartile range], 59.9 [10.4] years at survey and 68.3 [12.7] at surgery; 48% female). For each case, 2 matched referents were allocated. Plasma was analyzed with the multiplex proximity extension assay for screening of 92 cardiovascular candidate proteins. Conditional logistic regression models were used to assess associations between each protein and AS, with correction for multiple testing. A separate set of 106 additional cases with 212 matched referents was used in a validation study. RESULTS: Six proteins (growth differentiation factor 15, galectin-4, von Willebrand factor, interleukin 17 receptor A, transferrin receptor protein 1, and proprotein convertase subtilisin/kexin type 9) were associated with case status in the discovery cohort; odds ratios ranged from 1.25 to 1.37 per SD increase in the protein signal. Adjusting the multivariable models for classical cardiovascular risk factors at baseline yielded similar results. Subanalyses of case-referent triplets (n=133) who showed no visible coronary artery disease at the time of surgery in the index person supported associations between AS and growth differentiation factor 15 (odds ratio, 1.40; 95% confidence interval, 1.10-1.78) and galectin-4 (odds ratio, 1.27; 95% confidence interval, 1.02-1.59), but these associations were attenuated after excluding individuals who donated blood samples within 5 years before surgery. In triplets (n=201), which included index individuals with concurrent coronary artery disease at the time of surgery, all 6 proteins were robustly associated with case status in all sensitivity analyses. In the validation study, the association of all but 1 (interleukin 17 receptor A) of these proteins were replicated in patients with AS with concurrent coronary artery disease but not in patients with AS without coronary artery disease. CONCLUSIONS: We provide evidence that 5 proteins were altered years before AS surgery and that the associations seem to be driven by concurrent atherosclerotic disease.

LGALS4, CEACAM6, TSPAN8, and COL1A2: Blood Markers for Colorectal Cancer-Validation in a Cohort of Subjects With Positive Fecal Immunochemical Test Result.

BACKGROUND: A noninvasive blood test for the early detection of colorectal cancer (CRC) is highly required. We evaluated a panel of 4 mRNAs as putative markers of CRC. MATERIALS AND METHODS: We tested LGALS4, CEACAM6, TSPAN8, and COL1A2, referred to as the CELTiC panel, using quantitative reverse transcription polymerase chain reaction, on subjects with positive fecal immunochemical test (FIT) results and undergoing colonoscopy. Using a nonparametric test and multinomial logistic model, FIT-positive subjects were compared with CRC patients and healthy individuals. RESULTS: All the genes of the CELTiC panel displayed statistically significant differences between the healthy subjects (n = 67), both low-risk (n = 36) and high-risk/CRC (n = 92) subjects, and those in the negative-colonoscopy, FIT-positive group (n = 36). The multinomial logistic model revealed LGALS4 was the most powerful marker discriminating the 4 groups. When assessing the diagnostic values by analysis of the areas under the receiver operating characteristic curves (AUCs), the CELTiC panel reached an AUC of 0.91 (sensitivity, 79%; specificity, 94%) comparing normal subjects to low-risk subjects, and 0.88 (sensitivity, 75%; specificity, 87%) comparing normal and high-risk/CRC subjects. The comparison between the normal subjects and the negative-colonoscopy, FIT-positive group revealed an AUC of 0.93 (sensitivity, 82%; specificity, 97%). CONCLUSION: The CELTiC panel could represent a useful tool for discriminating subjects with positive FIT findings and for the early detection of precancerous adenomatous lesions and CRC.

The role of galectin-4 in physiology and diseases.

Galectin-4, a tandem repeat member of the ß-galactoside-binding proteins, possesses two carbohydrate-recognition domains (CRD) in a single peptide chain. This lectin is mostly expressed in epithelial cells of the intestinal tract and secreted to the extracellular. The two domains have 40% similarity in amino acid sequence, but distinctly binding to various ligands. Just because the two domains bind to different ligands simultaneously, galectin-4 can be a crosslinker and crucial regulator in a large number of biological processes. Recent evidence shows that galectin-4 plays an important role in lipid raft stabilization, protein apical trafficking, cell adhesion, wound healing, intestinal inflammation, tumor progression, etc. This article reviews the physiological and pathological features of galectin-4 and its important role in such processes.

Systematic large-scale meta-analysis identifies a panel of two mRNAs as blood biomarkers for colorectal cancer detection.

Colorectal cancer (CRC) is the third most common cancer in the world. A significant survival rate is achieved if it is detected at an early stage. A whole blood screening test, without any attempt to isolate blood fractions, could be an important tool to improve early detection of colorectal cancer. We searched for candidate markers with a novel approach based on the Transcriptome Mapper (TRAM), aimed at identifying specific RNAs with the highest differential expression ratio between colorectal cancer tissue and normal blood samples. This tool permits a large-scale systematic meta-analysis of all available data obtained by microarray experiments. The targeting of RNA took into consideration that tumour phenotypic variation is associated with changes in the mRNA levels of genes regulating or affecting this variation.A real time quantitative reverse transcription polymerase chain reaction (qRT- PCR) was applied to the validation of candidate markers in the blood of 67 patients and 67 healthy controls. The expression of genes: TSPAN8, LGALS4, COL1A2 and CEACAM6 resulted as being statistically different.In particular ROC curves attested for TSPAN8 an AUC of 0.751 with a sensitivity of 83.6% and a specificity of 58.2% at a cut off of 10.85, while the panel of the two best genes showed an AUC of 0.861 and a sensitivity of 92.5% with a specificity of 67.2%.Our preliminary study on a total of 134 subjects showed promising results for a blood screening test to be validated in a larger cohort with the staging stratification and in patients with other gastrointestinal diseases.

Galectin-4 serves as a prognostic biomarker for the early recurrence / metastasis of hepatocellular carcinoma.

Galectin-4 is a multifunctional lectin found at both intracellular and extracellular sites. It could serve as a tumor suppressor intracellularly and promote tumor metastases extracellularly during colorectal cancer development. However, galectin-4 expression and its prognostic value for patients with hepatocellular carcinoma (HCC) have not been well investigated. Here we report that galectin-4 was significantly downregulated in early recurrent/metastatic HCC patients, when compared to non-recurrent/metastatic HCC patients. Low expression of gelectin-4 was well associated with larger tumor size, microvascular invasion, malignant differentiation, more advanced TNM stage, and poor prognosis. Cancer cell migration and invasion could be significantly reduced through overexpression of galectin-4, but upregulated by knocking down of galectin-4 in vitro. Moreover, the serum galectin-4 level could be significantly elevated solely by hepatitis B virus infection. Combined with clinicopathological features, the higher serologic level of galectin-4 was well associated with more aggressive characteristics of HCC. Taken together, galectin-4 expression closely associates with HCC progression and might have potential use as a prognostic biomarker for HCC patients.

Circulating galectins -2, -4 and -8 in cancer patients make important contributions to the increased circulation of several cytokines and chemokines that promote angiogenesis and metastasis.

BACKGROUND: Circulating concentrations of the cytokines interleukin-6 (IL-6), granulocyte colony-stimulating factor (G-CSF) and chemokines monocyte chemotatic protein 1 (MCP-1)/CCL2 and growth-regulator oncogene α (GROα)/chemokine C-X-C motif ligand 1 are commonly increased in cancer patients and they are increasingly recognised as important promoters, via divergent mechanisms, of cancer progression and metastasis. METHODS: The effect of galectins-2, -4 and -8, whose circulating levels are highly increased in cancer patients, on endothelial secretion of cytokines was assessed in vitro by cytokine array and in mice. The relationship between serum levels of galectins and cytokines was analysed in colon and breast cancer patients. RESULTS: Galectins-2, -4 and -8 at pathological concentrations induce secretion of G-CSF, IL-6, MCP-1 and GROα from the blood vascular endothelial cells in vitro and in mice. Multiple regression analysis indicates that increased circulation of these galectins accounts for 41∼83% of the variance of these cytokines in the sera of colon and breast cancer patients. The galectin-induced secretion of these cytokines/chemokines is shown to enhance the expression of endothelial cell surface adhesion molecules, causing increased cancer-endothelial adhesion and increased endothelial tubule formation. CONCLUSION: The increased circulation of galectins -2, -4 and -8 in cancer patients contributes substantially to the increased circulation of G-CSF, IL-6 and MCP-1 by interaction with the blood vascular endothelium. These cytokines and chemokines in turn enhance endothelial cell activities in angiogenesis and metastasis.

Simultaneous determination of serum galectin-3 and -4 levels detects metastases in colorectal cancer patients.

BACKGROUND: Development of effective ways to detect metastases is highly desirable for improving the therapeutic strategies and survival of cancer patients. Serum levels of galectin-3 and -4, two members of the galactoside-binding galectin family, have recently been reported to be markedly increased up to 31-fold in the bloodstream of colorectal cancer patients and in particular those with metastases. RESULTS: We found that simultaneous determination of serum galectin-3 and -4 levels in a single assay provides a high specificity and sensitivity in distinguishing colorectal cancer patients without metastases from those with liver metastases. This result was partly attributed by a reciprocal relationship of serum galectin-3 and -4 levels in patients with metastases. Higher serum galectin-3/-4 levels at the time of primary tumour removal in patients who did not exhibit clinically detectable metastases were associated with a trend of a poorer patients' survival in the next 10 years. CONCLUSION: Simultaneous determination of serum galectin-3 and -4 levels can potentially be used alone or in combination with other assessments to detect colorectal cancer metastases.

Serum galectin-2, -4, and -8 are greatly increased in colon and breast cancer patients and promote cancer cell adhesion to blood vascular endothelium.

PURPOSE: Adhesion of disseminating tumor cells to the blood vascular endothelium is a pivotal step in metastasis. Previous investigations have shown that galectin-3 concentrations are increased in the bloodstream of patients with cancer and that galectin-3 promotes adhesion of disseminating tumor cells to vascular endothelium in vitro and experimental metastasis in vivo. This study determined the levels of galectin-1, -2, -3, -4, -8, and -9 in the sera of healthy people and patients with colon and breast cancer and assessed the influence of these galectins on cancer-endothelium adhesion. EXPERIMENTAL DESIGN: Serum galectins and auto-anti-MUC1 antibodies were assessed using ELISA and mucin protein (MUC1) glycan microarrays, and cancer-endothelium adhesion was determined using monolayers of human microvascular lung endothelial cells. RESULTS: The levels of serum galectin-2, -3, -4, and -8 were significantly increased up to 31-fold in patients with cancer and, in particular, those with metastases. As previously shown for galectin-3, the presence of these galectins enhances cancer-endothelium adhesion by interaction with the Thomsen-Friedenreich (TF; Galß1,3GalNAcα-) disaccharide on cancer-associated MUC1. This causes MUC1 cell surface polarization, thus exposing underlying adhesion molecules that promote cancer-endothelium adhesion. Elevated circulating galectin-2 levels were associated with increased mortality in patients with colorectal cancer, but this association was suppressed when anti-MUC1 antibodies with specificity for the TF epitope of MUC1 were also present in the circulation. CONCLUSIONS: Increased circulation of several members of the galectin family is common in patients with cancer and these may, like circulating galectin-3, also be involved in metastasis promotion.