Effects of experimental ulcerative colitis on myenteric neurons in P2X7-knockout mice

Author(s)

Machado, Felipe Alexandre ; Souza, Roberta Figueiroa ; Figliuolo, Vanessa Ribeiro ; Coutinho-Silva, Robson ; Castelucci, Patricia

• Document type: Journal article
• Source: Histochemistry and Cell Biology; v. 160, n. 4, p. 19-pg., 2023-06-12.

Abstract

This study aimed to investigate the distal colon myenteric plexus and enteric glial cells (EGCs) in P2X7 receptor-deficient (P2X7-/-) animals after the induction of experimental ulcerative colitis. 2,4,6-Trinitrobenzene sulfonic acid (TNBS) was injected into the distal colon of C57BL/6 (WT) and P2X7 receptor gene-deficient (P2X7-/-, KO) animals. Distal colon tissues in the WT and KO groups were analyzed 24 h and 4 days after administration. The tissues were analyzed by double immunofluorescence of the P2X7 receptor with neuronal nitric oxide synthase (nNOS)-immunoreactive (ir), choline acetyltransferase (ChAT)-ir, and PGP9.5 (pan neuronal)-ir, and their morphology was assessed by histology. The quantitative analysis revealed 13.9% and 7.1% decreases in the number of P2X7 receptor-immunoreactive (ir) per ganglion in the 24 h-WT/colitis and 4 day-WT/colitis groups, respectively. No reduction in the number of nNOS-ir, choline ChAT-ir, and PGP9.5-ir neurons per ganglion was observed in the 4 day-KO/colitis group. In addition, a reduction of 19.3% in the number of GFAP (glial fibrillary acidic protein)-expressing cells per ganglion was found in the 24 h-WT/colitis group, and a 19% increase in the number of these cells was detected in the 4 day-WT/colitis group. No profile area changes in neurons were observed in the 24 h-WT and 24 h-KO groups. The 4 day-WT/colitis and 4 day-KO/colitis groups showed increases in the profile neuronal areas of nNOS, ChAT, and PGP9.5. The histological analysis showed hyperemia, edema, or cellular infiltration in the 24 h-WT/colitis and 4 day-WT/colitis groups. Edema was observed in the 4 day-KO/colitis group, which showed no histological changes compared with the 24 h-KO/colitis group. We concluded that ulcerative colitis differentially affected the neuronal classes in the WT and KO animals, demonstrating the potential participation and neuroprotective effect of the P2X7 receptor in enteric neurons in inflammatory bowel disease. (AU)

• FAPESP's process: 18/07862-1 - Study of the effect of experimental ulcerative colitis on the enteric nervous system of P2X7 receptor deficient mice (P2X7-/-)
• Grantee: Patricia Castelucci
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/25927-2 - Morphological, molecular and functional aspects of the interaction between the P2X7 receptor and pannexin-1 in the enteric glial cells following intestinal ischemia/reperfusion
• Grantee: Patricia Castelucci
• Support Opportunities: Regular Research Grants