title: Myeloperoxidase expression in human colonic mucosa is related to systemic oxidative balance in healthy subjects.
abstract: OBJECTIVE
  To improve understanding of the preclinical stage of colonic inflammation by exploring the existence of a link between early inflammatory changes in the colonic mucosa and the systemic redox balance.
  
  
  METHODS
  Clinical characteristics, a fasting blood draw, and mucosal biopsies from the right, left, and sigmoid-rectum colonic tracts collected from 28 healthy individuals (14/14 males/females) who underwent colonoscopy. Myeloperoxidase (MPO) positive cells infiltrating colonic mucosa specimens were assessed by immunohistochemistry, and patients divided into high or low MPO expressing cells/optical field groups (MPOhighor MPOlow, respectively).The systemic oxidative balance has been studied through derived-Reactive Oxygen Metabolites (d-ROMs), Biological Antioxidant Potential (BAP), and Lipoperoxide-cholesterol Oxidizing (LP-CHOLOX) tests on serum.
  
  
  RESULTS
  MPOhighpatients demonstrated an increased systemic oxidative stress compared to MPOlowindividuals (P = 0.035), especially when MPO is referred to the left-sided colonic mucosa (P = 0.007). MPOlowsubjects in the sigmoid-rectum showed a significant higher antioxidant capacity in the serum (P < 0.02). Sex-specific differences in MPO expression (male and female: 4.6 ± 3.2 and 2.6 ± 1.5 MPO-positive cells/optical field, respectively, P = 0.044), and a decreasing gradient in MPO expression moving from the cecum to the rectum (ascendant, descendant, and sigmoid-rectum: 3.7 ± 2.8, 3.1 ± 1.7, and 1.4 ± 0.5, respectively, P = 0.012) were also found and discussed.
  
  
  CONCLUSIONS
  The study is the first demonstrating a connection between systemic redox balance and MPO expression in the colonic mucosa, according to the colonic tract and patient gender. Further research evaluating the MPO expression in the human colon and its relationship with pathological conditions could benefit from these results.
authors.affiliation: a Department of Diagnostics, Clinical, and Public Health Medicine, Section of Human Morphology , University of Modena and Reggio Emilia , Modena , Italy.
authors.forename: Stefano
authors.identifier: http://orcid.org/0000-0002-7350-5603
authors.initials: S
authors.lastname: Mancini
authors.affiliation: a Department of Diagnostics, Clinical, and Public Health Medicine, Section of Human Morphology , University of Modena and Reggio Emilia , Modena , Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mariani
authors.affiliation: b Department of Biomedical, Metabolic, and Neural Sciences, Section of Human Morphology , University of Modena and Reggio Emilia , Modena , Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Sena
authors.affiliation: b Department of Biomedical, Metabolic, and Neural Sciences, Section of Human Morphology , University of Modena and Reggio Emilia , Modena , Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Benincasa
authors.affiliation: a Department of Diagnostics, Clinical, and Public Health Medicine, Section of Human Morphology , University of Modena and Reggio Emilia , Modena , Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Roncucci
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D003106:Colon / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D003113:Colonoscopy; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D009195:Peroxidase / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D009195:Peroxidase
keywords: MPO; Myeloperoxidase; antioxidant capacity; colonic inflammation; colonic mucosa; oxidative stress; redox balance