Alice Rigoni1, Richard Poulsom2, Rosemary Jeffery2, Shameer Mehta2, Amy Lewis2, Christopher Yau3, Eleni Giannoulatou4,5, Roger Feakins6, James O Lindsay7, Mario P Colombo1, Andrew Silver2. 1. Molecular Immunology Unit, Department of Research, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. 2. Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK. 3. Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK. 4. Victor Chang Cardiac Research Institute, Sydney, NSW, Australia. 5. St Vincent's Clinical School, University of New South Wales, Sydney, NSW, Australia. 6. Department of Histopathology, The Royal London Hospital, London, UK. 7. Centre for Immunobiology, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Abstract
Background: DUOX2 and DUOXA2 form the predominant H2O2-producing system in human colorectal mucosa. Inflammation, hypoxia, and 5-aminosalicylic acid increase H2O2 production, supporting innate defense and mucosal healing. Thiocyanate reacts with H2O2 in the presence of lactoperoxidase (LPO) to form hypothiocyanate (OSCN-), which acts as a biocide and H2O2 scavenging system to reduce damage during inflammation. We aimed to discover the organization of Duox2, Duoxa2, and Lpo expression in colonic crypts of Lieberkühn (intestinal glands) of mice and how distributions respond to dextran sodium sulfate (DSS)-induced colitis and subsequent mucosal regeneration. Methods: We studied tissue from DSS-exposed mice and human biopsies using in situ hybridization, reverse transcription quantitative polymerase chain reaction, and cDNA microarray analysis. Results: Duox2 mRNA expression was mostly in the upper crypt quintile while Duoxa2 was more apically focused. Most Lpo mRNA was in the basal quintile, where stem cells reside. Duox2 and Duoxa2 mRNA were increased during the induction and resolution of DSS colitis, while Lpo expression did not increase during the acute phase. Patterns of Lpo expression differed from Duox2 in normal, inflamed, and regenerative mouse crypts (P < 0.001). We found no evidence of LPO expression in the human gut. Conclusions: The spatial and temporal separation of H2O2-consuming and -producing enzymes enables a thiocyanate- H2O2 "scavenging" system in murine intestinal crypts to protect the stem/proliferative zones from DNA damage, while still supporting higher H2O2 concentrations apically to aid mucosal healing. The absence of LPO expression in the human gut suggests an alternative mechanism or less protection from DNA damage during H2O2-driven mucosal healing.
Background: DUOX2 and DUOXA2 form the predominant H2O2-producing system in humancolorectal mucosa. Inflammation, hypoxia, and 5-aminosalicylic acid increase H2O2 production, supporting innate defense and mucosal healing. Thiocyanate reacts with H2O2 in the presence of lactoperoxidase (LPO) to form hypothiocyanate (OSCN-), which acts as a biocide and H2O2 scavenging system to reduce damage during inflammation. We aimed to discover the organization of Duox2, Duoxa2, and Lpo expression in colonic crypts of Lieberkühn (intestinal glands) of mice and how distributions respond to dextran sodium sulfate (DSS)-induced colitis and subsequent mucosal regeneration. Methods: We studied tissue from DSS-exposed mice and human biopsies using in situ hybridization, reverse transcription quantitative polymerase chain reaction, and cDNA microarray analysis. Results:Duox2 mRNA expression was mostly in the upper crypt quintile while Duoxa2 was more apically focused. Most Lpo mRNA was in the basal quintile, where stem cells reside. Duox2 and Duoxa2 mRNA were increased during the induction and resolution of DSScolitis, while Lpo expression did not increase during the acute phase. Patterns of Lpo expression differed from Duox2 in normal, inflamed, and regenerative mouse crypts (P < 0.001). We found no evidence of LPO expression in the human gut. Conclusions: The spatial and temporal separation of H2O2-consuming and -producing enzymes enables a thiocyanate- H2O2 "scavenging" system in murine intestinal crypts to protect the stem/proliferative zones from DNA damage, while still supporting higher H2O2 concentrations apically to aid mucosal healing. The absence of LPO expression in the human gut suggests an alternative mechanism or less protection from DNA damage during H2O2-driven mucosal healing.
Authors: Keane K Y Lai; Xiaohui Hu; Keisuke Chosa; Cu Nguyen; David P Lin; Keith K Lai; Nobuo Kato; Yusuke Higuchi; Sarah K Highlander; Elizabeth Melendez; Yoshihiro Eriguchi; Patrick T Fueger; Andre J Ouellette; Nyam-Osor Chimge; Masaya Ono; Michael Kahn Journal: Cancers (Basel) Date: 2021-03-14 Impact factor: 6.639
Authors: C Felice; A Lewis; S Iqbal; H Gordon; A Rigoni; M P Colombo; A Armuzzi; R Feakins; J O Lindsay; A Silver Journal: Cell Mol Gastroenterol Hepatol Date: 2020-11-21