Polyamines appear to be involved in the turnover, growth and maintenance of intestinal mucosa integrity. Since polyamines could act -in part at least- through their incorporation into cellular proteins as catalyzed by transglutaminase, we have measured this enzyme activity in villus enterocytes isolated from pig jejunum and in homogenate derived from isolated cells. A part of putrescine, spermidine and spermine taken up by enterocytes is incorporated in TCA precipitable material derived from cells and this corresponds to the presence of transglutaminase activity in cellular homogenates. This activity which is time and substrate concentration dependent is strongly inhibited by the transglutaminase inhibitor glycine methyl ester. The capacity for de novo production of polyamines from L-arginine or L-glutamine is very limited in isolated enterocytes, and this coincided with a very low ornithine decarboxylase activity when compared with polyamine cell content. It is concluded that the main source of polyamines for pig enterocytes is extracellular and that exogenous polyamines are substrates for enterocyte transglutaminase.
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http://dx.doi.org/10.1007/BF00926881 | DOI Listing |
J Immunother Cancer
January 2025
Internal Medicine I, Ulm University Hospital, Ulm, Germany
Background: Pancreatic ductal adenocarcinoma (PDAC) is mostly refractory to immunotherapy due to immunosuppression in the tumor microenvironment and cancer cell-intrinsic T cell tolerance mechanisms. PDAC is described as a "cold" tumor type with poor infiltration by T cells and factors leading to intratumoral T cell suppression have thus received less attention. Here, we identify a cancer cell-intrinsic mechanism that contributes to a T cell-resistant phenotype and describes potential combinatorial therapy.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food and Nutrition, Joint Research Center for Food Nutrition and Health of IHM, Anhui Agriculture University, Hefei, Anhui 230036, China. Electronic address:
Micelle systems using safe food-grade biopolymers are of particular interest for the encapsulation and delivery of nutrition components. Micellar casein (MC) was assembled using transglutaminase (TGase) to couple with phosphoserine peptide, which enhance the stability of docosahexaenoic acid (DHA) from algae oil. The mechanism behind the construction of MC-phosphoserine peptide and the encapsulation of DHA was explored.
View Article and Find Full Text PDFMiddle East J Dig Dis
October 2024
Department of Pediatrics, All India Institute of Medical Sciences (AIIMS), Bhopal, Madhya Pradesh, India.
Celiac disease (CD) is an immune-mediated enteropathy with varied systemic involvement and association with increased morbidity and mortality. Strong clinical suspicion is the key, and diagnosis is made using histopathology and serology. Though the consumption of a strict gluten-free diet can improve symptoms and limit mucosal damage, curative therapy is still lacking.
View Article and Find Full Text PDFArthritis Rheumatol
January 2025
Division of Medicine, Department of Inflammation and Rare Diseases, UCL Centre for Rheumatology, University College London, London, NW3 2PF, UK.
Objective: Scleroderma is a life-threatening autoimmune disease characterized by inflammation, tissue remodelling, and fibrosis. This study aimed to investigate the expression and function of transglutaminase 2 (TGM2) in scleroderma skin and experimentally-induced dermal fibrosis to determine its potential role and therapeutic implications.
Methods: We performed immunohistochemistry on skin sections to assess TGM2 expression and localisation, and protein biochemistry of both SSc-derived and healthy control dermal fibroblasts to assess TGM2 expression, function and ECM deposition in the presence of a TGM2 and TGFβ neutralizing antibodies and a small molecule inhibitor of the TGFβRI kinase.
Foods
December 2024
Department of Digestive Tract Diseases, Medical University of Lodz, 90-153 Lodz, Poland.
Background: Celiac disease (CD) is an autoimmune disease that results from the interaction of genetic, immune, and environmental factors. According to the 2020 European Society for Pediatric Gastroenterology Hepatology and Nutrition (ESPGHAN) guidelines, an elimination diet (i.e.
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