Tissue Transglutaminase Research Papers - Academia.edu (original) (raw)

Malignancies arising from biliary tract epithelia, or cholangiocarcinoma, are rare tumors that have a poor prognosis. The incidence of these tumors is gradually increasing in many countries. Recent advances have been made in identifying... more

Malignancies arising from biliary tract epithelia, or cholangiocarcinoma, are rare tumors that have a poor prognosis. The incidence of these tumors is gradually increasing in many countries. Recent advances have been made in identifying some of the risk factors, and the need for appropriate classification is emerging. The diagnosis of cholangiocarcinoma is often difficult and requires multiple complementary studies. The use of molecular approaches may improve the diagnostic utility of biliary cytology. Treatment of these tumors is complex, and there are many different treatment options. Although surgical resection can be curative, many patients with cholangiocarcinoma are diagnosed at an advanced stage when only palliative approaches can be used. Photodynamic therapy is emerging as a useful modality.

Leukocyte infiltration into the central nervous system is an important feature of multiple sclerosis (MS) pathology. Among the infiltrating cells, monocytes comprise the largest population and are considered to play a dual role in the... more

Leukocyte infiltration into the central nervous system is an important feature of multiple sclerosis (MS) pathology. Among the infiltrating cells, monocytes comprise the largest population and are considered to play a dual role in the course of the disease. The enzyme tissue transglutaminase (TG2), produced by monocytes, plays a central role in monocyte adhesion/migration in animal models of MS. In the present study, we questioned whether TG2 expression is altered in monocytes from MS patients compared to healthy control (HC) subjects. Moreover, we determined the inflammatory status of these TG2-expressing monocytes, what inflammatory factor regulates TG2 expression, and whether TG2 can functionally contribute to their adhesion/migration processes. Primary human monocytes from MS patients and HC subjects were collected, RNA isolated and subjected to qPCR analysis. Human THP-1 monocytes were lentivirally transduced with TG2 siRNA or control and treated with various cytokines. Subsequ...

Effects of acetylcholine and of the cholinergic precursors choline, cytidine 5′-diphosphocholine (CDP-choline) and α-glyceril-phosphorylcholine (α-GPC) on transglutaminase (TG) and cyclin D1 expression were studied in primary astrocyte... more

Effects of acetylcholine and of the cholinergic precursors choline, cytidine 5′-diphosphocholine (CDP-choline) and α-glyceril-phosphorylcholine (α-GPC) on transglutaminase (TG) and cyclin D1 expression were studied in primary astrocyte cultures by confocal laser microscopy (CLSM) with monodansyl-cadaverine uptake as a marker of enzyme activity and by immunochemistry (Western blotting). CLSM analysis showed an increased cytofluorescence in 0.1 μM choline-treated astrocytes. Treatment with CDP-choline dose-dependently increased TG. A total of 1 μM CDP-choline exposure in 14 days in vitro (DIV) astrocyte cultures increased cytofluorescence. A total of 1 μM α-GPC 24 h-treated cultures revealed increased cytofluorescence both in cytosol and nuclei. Western blot analysis showed an increased TG expression in cultures exposed for 24 h to 1 μM choline or α-GPC, whereas in 24 h 1 μM CDP-choline and acetylcholine-treated astrocytes TG expression was unaffected. Treatment with 1 μM acetylcholine reduced TG expression at 21 DIV. In cultures at 14 and 35 DIV cholinergic precursor treatment for 24 h induced a marked down-regulation of cyclin D1 expression, with reduced cyclin D1 expression in 1 μM α-GPC treated astrocytes. Our data suggest a role of cholinergic precursors investigated independent from acetylcholine on maturation and differentiation of astroglial cells in vitro, rather than on their growth, proliferation and development in culture.

The food intake in developed countries is characterized by a deficient consumption of n-3 fatty acids and fiber. In this study, modified beef patties enriched with polyunsaturated n-3 fatty acids and fiber were developed. The texture... more

The food intake in developed countries is characterized by a deficient consumption of n-3 fatty acids and fiber. In this study, modified beef patties enriched with polyunsaturated n-3 fatty acids and fiber were developed. The texture profile was compared to traditional beef patties, showing lower values for all parameters except springiness. To improve its texture, pretreatments using transglutaminase (TG) and

Parenchyma cells of dormant Helianthus tuberosus tubers were induced to enter a synchronous cell cycle with the aim of studying therein the modifications which proteins undergo when they bind to polyamines. A transglutaminase-like... more

Parenchyma cells of dormant Helianthus tuberosus tubers were induced to enter a synchronous cell cycle with the aim of studying therein the modifications which proteins undergo when they bind to polyamines. A transglutaminase-like activity (TGase-like), which increases during the cell cycle, produces high molecular mass conjugates with [ 3 H]- and [ 14 C]-putrescine (PU) that can be precipitated with trichloroacetic acid or ammonium sulphate, together with complexes in which PU is not covalently bound. These pellets were subjected to acidic hydrolysis at high temperature and the amount of PU was determined by thin layer chromatography: PU decreases untill mid-G 1 and then increases during the cell cycle, remaining stationary only at the beginning of cell division

Glutamate exposure of astroglial cells caused ligand-gated channel receptor activation, associated with excitotoxic cell response. We investigated the effects of 24 h glutamate exposure on transglutaminase in astrocytes primary cultures... more

Glutamate exposure of astroglial cells caused ligand-gated channel receptor activation, associated with excitotoxic cell response. We investigated the effects of 24 h glutamate exposure on transglutaminase in astrocytes primary cultures at 7, 14, and 21 days in vitro (DIV). Increases in enzyme activity were observed as a function of cell differentiation stage in glutamate-treated cultures. These effects were significantly reduced when GYKI 52466, an AMPA/KA receptors inhibitor, was added to the culture medium prior to incubation with glutamate. Microscopy observation on transglutaminase-mediated, fluorescent dansylcadaverine incorporation in living cells was consistent with these results. Western blotting analysis with monoclonal antibody showed that glutamate also up-regulated tissue transglutaminase expression, which reached the highest values in 14 DIV cultures. Confocal laser scanning microscopy analysis of immunostained astroglial cells showed a mainly cytoplasmic localisation of the enzyme both in control and treated cultures; nevertheless, counterstaining with the nuclear dye acridine orange demonstrated the presence of tissue transglutaminase also into the nucleus of glutamate-exposed and 21 DIV cells. The increases in enzyme expression and localisation in the nucleus of glutamate-treated astroglial cells may be part of biochemical alterations induced by excitotoxic stimulus.

In 2012 the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) published an updated guideline for the diagnosis of Coeliac disease, allowing symptomatic individuals with appropriate serology and HLA... more

In 2012 the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) published an updated guideline for the diagnosis of Coeliac disease, allowing symptomatic individuals with appropriate serology and HLA genotype to be diagnosed without a small bowel biopsy. This retrospective study aimed to assess the applicability of this guideline to children in . Children less than 16 years of age investigated for coeliac disease with small bowel biopsy in between January 2010 and December 2012 were identified. The results of those with tissue transglutaminase IgA (tTG) levels greater than 50 units (10 times upper limit of normal), positive endomysial antibodies and HLA DQ2/DQ8 were used to calculate sensitivity and specificity. Data from 160 children was available: 70 had biopsy-confirmed Coeliac disease, and 90 had negative biopsies. Limited data precluded application of the guidelines to all patients. Using only tTG data, levels above 50 units provided a sensitivity of 67% and a specificity of 92%. Specificity increased to 97% when limited EMA and HLA DQ2/DQ8 data was added. Despite limited data, applying the ESPGHAN guidelines in the paediatric population over this period produced a high specificity (97%). Prospective studies are now required to confirm these findings.

The neurodegenerative disease multiple sclerosis (MS) is pathologically characterized by the massive influx of immune cells into the central nervous system. This contributes to demyelination and axonal damage which causes symptoms such as... more

The neurodegenerative disease multiple sclerosis (MS) is pathologically characterized by the massive influx of immune cells into the central nervous system. This contributes to demyelination and axonal damage which causes symptoms such as motor and cognitive dysfunctions. The migration of leukocytes from the blood vessel is orchestrated by a multitude of factors whose determination is essential in reducing cellular influx in MS patients and the experimental autoimmune encephalomyelitis (EAE) animal model. The here studied enzyme tissue Transglutaminase (TG2) is present intracellularly, on the cell surface and extracellularly. There it contributes to cellular adhesion and migration via its transamidation activity and possibly by facilitating cellular interaction with the extracellular matrix. Previous data from our group showed reduced motor symptoms and cellular infiltration after using a pharmacological TG2 transamidation activity inhibitor in a rat EAE model. However, it remained ...

Leukocyte infiltration into the central nervous system (CNS) is a key pathological feature in multiple sclerosis (MS) and the MS animal model experimental autoimmune encephalomyelitis (EAE). Recently, preventing leukocyte influx into the... more

Leukocyte infiltration into the central nervous system (CNS) is a key pathological feature in multiple sclerosis (MS) and the MS animal model experimental autoimmune encephalomyelitis (EAE). Recently, preventing leukocyte influx into the CNS of MS patients is the main target of MS therapies and insight into cell behaviour in the circulation is needed for further elucidation of such therapies. In this study, we aimed at in vivo visualization of monocytes in a time-dependent manner during EAE. Using intravital two-photon microscopy (IVM), we imaged CX3CR1(gfp/gfp) mice during EAE, visualizing CX3CR1-GFP(+) monocytes and their dynamics in the spinal cord vasculature. Our observations showed that intraluminal crawling of CX3CR1-GFP(+) monocytes increased even before the clinical onset of EAE due to immunization of the animals. Furthermore, intraluminal crawling remained elevated during ongoing clinical disease. Besides, the displacement of these cells was larger during the peak of EAE c...

Although the incidence of celiac disease (CD) is increasing, studies have been hampered by the lack of validated outcome measures. We sought to create a disease-specific Celiac Symptom Index (CSI) to reliably assess relevant symptoms. A... more

Although the incidence of celiac disease (CD) is increasing, studies have been hampered by the lack of validated outcome measures. We sought to create a disease-specific Celiac Symptom Index (CSI) to reliably assess relevant symptoms. A 36-item questionnaire was created after design by an expert committee and review/revision by patient focus groups. The survey, covering domains of CD-related symptoms and general health, was initially administered to 154 individuals with biopsy-proven CD; immunoglobulin (Ig)A tissue transglutaminase titers were determined, and gluten-free diet adherence was evaluated by a dietitian. The questionnaire was then revised to exclude questions with poor test characteristics and administered to a second, independent group of 52 individuals, to ensure validity. The subscales of "specific symptoms" and "general health" had excellent psychometric qualities that consisted of 11 and 5 items, respectively. The additive score based on these items was correlated with current general health, as measured by a visual analog scale and short form 36 general health subscale (P < or = .001 for both), as well as degree of adherence to the gluten-free diet (P = .008), lending external validity to the CSI. The resulting 16 questions make up the first CD-specific symptom index. The CSI allows for disease-specific monitoring of symptoms as an independent outcome measure or as part of a surrogate for disease activity in individuals with CD. The CSI might be an important tool for future clinical CD research.

BACKGROUND: The usefulness of celiac disease-related serology in monitoring patients on a gluten-free diet has been debated. AIM: To describe serologic changes over time and assess whether serology tests can predict compliance with the... more

BACKGROUND: The usefulness of celiac disease-related serology in monitoring patients on a gluten-free diet has been debated. AIM: To describe serologic changes over time and assess whether serology tests can predict compliance with the gluten-free diet. METHODS ...

Celiac disease (CD) is the most common autoimmune enteropathy in the western world caused by the intolerance to gluten in genetically predisposed individuals. CD is characterized by a remarkable rearrangement of the mucosal architecture,... more

Celiac disease (CD) is the most common autoimmune enteropathy in the western world caused by the intolerance to gluten in genetically predisposed individuals. CD is characterized by a remarkable rearrangement of the mucosal architecture, in which process myofibroblasts play a crucial role. Myofibroblasts (intestinal subepithelial myofibroblasts and interstitial cells of Cajal) are the most represented mesenchymal cell types in the gut mucosa and are involved in a broad range of biological processes including growth, mucosal protection, repair, inflammation and fibrosis. Myofibroblasts actively contribute to the mucosal changes in CD due to their ability to produce an excessive amount of extracellular matrix and basement membrane components (e.g. collagens, fibronectin, and specific enzymes including tissue transglutaminases) and through the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs). The enhanced production of ECM components and MMPs and the altered shape and motility of myofibroblasts in the duodenal mucosa of patients with CD suggest that myofibroblasts may play an essential role in the pathogenesis of CD.

Transamidation of α-synuclein by the Ca(2+)-dependent enzyme tissue transglutaminase (tTG, EC 2.3.2.13) is implicated in... more

Transamidation of α-synuclein by the Ca(2+)-dependent enzyme tissue transglutaminase (tTG, EC 2.3.2.13) is implicated in Parkinson's disease (PD). tTG may therefore offer a novel therapeutic target to intervene in PD. Here we first evaluated the potency and efficacy of three recently developed irreversible active-site inhibitors of tTG (B003, Z006 and KCC009) to inhibit tTG activity in vitro and in living cells. In vitro, all compounds were found to be full inhibitors of tTG activity showing a rank order of potency (defined by IC-50 values) of Z006>B003>KCC009. Upon Ca(2+) ionophore (A23187) induced activation of cellular tTG (measured by incorporation of the tTG-specific amine substrate 5-(biotinamido)pentylamine (BAP) into cellular proteins) in neuroblastoma SH-SY5Y cells, only Z006 (0.3-30 μM) retained the capacity to completely inhibit tTG activity. Under these conditions B003 (3-300 μM) only partially blocked tTG activity whereas KCC009 (3-100 μM) failed to affect tTG activity at any of the concentrations used. Z006 (30 μM) also blocked the tTG mediated incorporation of BAP into α-synuclein monomers and SDS-resistant multimers in vitro and in α-synuclein overexpressing SHSY5Y cells exposed to A23187 or the PD mimetic 1-methyl-4-phenylpyridine (MPP(+)). Moreover, Z006 (30 μM) substantially reduced formation of SDS-resistant α-synuclein multimers in SH-SY5Y cells exposed to A23187 or MPP(+) in the absence of BAP. We conclude that α-synuclein is a cellular substrate for tTG under conditions mimicking PD and blockade of tTG activity counteracts α-synuclein transamidation and aggregation in vitro and in living cells. Moreover, our cell model appears an excellent readout to identify candidate inhibitors of intracellular tTG.

Significant progresses on the anti-tissue transglutaminase antibodies (anti-tTG) ELISA tests have been achieved since anti-tTG early development. Our goal was to study the optimization of the antigen immobilization and the antibody... more

Significant progresses on the anti-tissue transglutaminase antibodies (anti-tTG) ELISA tests have been achieved since anti-tTG early development. Our goal was to study the optimization of the antigen immobilization and the antibody reaction conditions in an ELISA test for the detection of anti-tTG. Hence, three variants of an anti-tTG ELISA test were developed: tTG-Gliad-U, tTG-U and tTG-Gliad, according to the coating conditions (presence/absence of gli- adin) and the stringency in the sample buffer (presence/absence of urea). To assess IgA and IgG anti-tTG frequencies we used a group of 117 CD patients, 36 under a gluten-free diet and 14 with a selective IgA deficiency, and a control group of 165 non-celiac patients. Sensitivity of IgA anti-tTG in CD patients with villous atrophy was 95.5% (tTG-Gliad-U), 65.0% (tTG-U) and 92.5% (tTG-Gliad), respectively. Sensitivity of the IgG anti-tTG assay was 79.0%, 21.0% and 79.0%, re- spectively. Specificities ranged between 92.9% and 100%. S...

To estimate the frequency of celiac disease (CD) in children in the general population of Denver, Colorado. From 22,346 newborns characterized as expressing 0, 1, or 2 HLA-DR3(DQB1*0201) alleles, 987 were selected for a prospective... more

To estimate the frequency of celiac disease (CD) in children in the general population of Denver, Colorado. From 22,346 newborns characterized as expressing 0, 1, or 2 HLA-DR3(DQB1*0201) alleles, 987 were selected for a prospective stratified cohort study. Participants were followed for as long as 7 years with serial testing for serum IgA anti-transglutaminase antibodies and for evidence of CD (intestinal mucosal changes or persistent seropositivity). Of 40 children with at least one positive serologic test, 19 had evidence of CD (10 by biopsy, 9 by persistent seropositivity). Those expressing 0, 1, or 2 HLA-DR3 alleles had, respectively, 0.3% (95% CI, 0.0-2.7), 3.4% (3.0-11.7), and 3.2% (1.0-11.0) risk for evidence of CD by age 5 years. The adjusted risk estimate for evidence of CD by age 5 years for the Denver general population was 0.9% (0.4-2.0), or 1 in 104 (1:49-221). After adjusting for number of HLA-DR3 alleles expressed, risk was higher in females: RR=3.34 (1.00-10.9, P=.048). Evidence of CD was not observed before age 2.6 years. Celiac disease may affect 0.9% of Denver children by 5 years of age. Children positive for the HLA-DR3 allele and females appear to be at increased risk.

Imatinib, a tyrosine kinase inhibitor directed against the enzymatic domain of KIT protein, was found to produce dramatic clinical responses in metastatic gastrointestinal stromal tumors (GISTs). However, resistance usually develops thus... more

Imatinib, a tyrosine kinase inhibitor directed against the enzymatic domain of KIT protein, was found to produce dramatic clinical responses in metastatic gastrointestinal stromal tumors (GISTs). However, resistance usually develops thus determining treatment failure. The present study was performed to analyse the expression of somatostatin receptor (SSTR) subtypes, modulators of tissue transglutaminase, in a series of GISTs and leiomyosarcomas by immunohistochemistry to identify a new potential therapeutic target. Sixteen cases (8 males and 8 females, age range: 38–73; 11 GISTs, 4 leiomyosarcomas, 1 leiomyoma) were studied. Immunohistochemical detection of the relevant SSTRs was performed on paraffin-embedded tissue sections, stained with polyclonal antibodies directed against the five somatostatin receptor subtypes. We found 7 out of 16 (44%) tumors expressing all SSTRs and 14 out of 16 (87%) tumors positive for at least 3 subtypes. SSTR2A was the most represented subtype in the tumors studied, being expressed in approximately 70% of cases exhibiting an intense labeling in most of these cases. The significant expression of SSTRs shown in this series of GISTs and gastrointestinal leiomyosarcomas suggests a potential therapeutic target to be explored alone and/or in combination with other therapeutic agents in the setting of refractory GI stromal tumors.