Myeloperoxidase expression in human colonic mucosa is related to systemic oxidative balance in healthy subjects

ABSTRACT

Objectives: 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 (MPO^high or MPO^low, 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: MPO^high patients demonstrated an increased systemic oxidative stress compared to MPO^low individuals (P = 0.035), especially when MPO is referred to the left-sided colonic mucosa (P = 0.007). MPO^low subjects 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.

Discussion: 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.

KEYWORDS:

• Myeloperoxidase
• MPO
• oxidative stress
• colonic mucosa
• redox balance
• antioxidant capacity
• colonic inflammation

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Stefano Mancini graduated in Medicine and Surgery from the University of Bologna, Italy (2004), and then specialized in Internal Medicine at the University of Modena and Reggio Emilia where he is currently completing his PhD degree in ‘Clinical and Experimental Medicine.’ His research has focused initially on the cardiometabolic risk factors and then focused on mechanisms of carcinogenesis mediated by the immune system and inflammation in the colorectum. His PhD project concerns the definition of a global risk model for the development of colorectal cancer.

Francesco Mariani graduated in Chemistry and Pharmaceutical Technology, and he is PhD in ‘Experimental and Clinical Oncology’ from the University of Modena and Reggio Emilia. His field of research has focused on the molecular and metabolic mechanisms leading to the development of colorectal cancer. He works as a researcher at the Department of Diagnostics, Clinical, and Public Health Medicine, and also he is obtaining a second degree in Medicine and Surgery, at the University of Modena and Reggio Emilia.

Paola Sena had a degree in Biology from the University of Modena and Reggio Emilia and then obtained a PhD in ‘Oncological Surgery of the Digestive System’. He is currently Assistant Professor at the Department of Biomedical Sciences, Metabolic and Neuroscience at the University of Modena and Reggio Emilia, where he teaches Anatomy and Histology. Her scientific work covers the molecular biology and signaling in inflammatory foci of aberrant crypts of the human colon, and she is an expert in developmental biology.

Marta Benincasa earned a degree in Chemistry from the University of Modena and Reggio Emilia and then a Master degree in Methodology of Laboratory Research (1992). She is scientific laboratory technician in the Department of Biomedical, Metabolic and Neural Sciences since 1995. Technical Skills: maintenance of cell line cultures in adhesion and suspension; mono- and bi-dimensional gel-electrophoresis; immunohistochemistry; immunofluorescence; bidimensional HPLC in proteomics analysis.

Luca Roncucci, MD, PhD, specialized in Internal Medicine, is Associate Professor in the Department of Internal Medicine of the University of Modena and Reggio Emilia. He trained as Research Fellow at the Ontario Cancer Institute of Toronto, Canada with a grant from the National Research Council of Italy, and obtained his PhD degree at the University of Modena in Human Pathology in 1995. Scientific research work focused mainly on colorectal neoplastic diseases, starting since 1983. He developed particular expertise on cell kinetics in normal colorectal mucosa and neoplastic colorectal lesions, chemoprevention of adenoma recurrence, the familiarity of colorectal cancer, and early events of human colorectal carcinogenesis (first report of aberrant crypt foci and mucin-depleted foci in the human colon).

ORCID

Stefano Mancini http://orcid.org/0000-0002-7350-5603

Additional information

Funding

This work was supported by Associazione Ricerca Tumori Intestinali - ARTI.