A242 STOOL FROM IBS-D PATIENT WITH A HISTORY OF A DYSBIOTIC AND NON-DYSBIOTIC ONSET MODULATE NEURONAL EXCITABILITY VIA DIFFERENT MECHANISMS

Autor: N N Jiménez-Vargas, M Guzman Rodriguez, Y Yu, E Neary, A E Lomax, D E Reed, S Vanner
Rok vydání: 2022
Zdroj: Journal of the Canadian Association of Gastroenterology. 5:134-135
ISSN: 2515-2092
2515-2084
DOI: 10.1093/jcag/gwab049.241
Popis: Background We have shown that Irritable Bowel Syndrome diarrhea-predominant (IBS-D) patients with a history of a dysbiotic-like onset have distinct stool metabolomic profiles versus those with a non-dysbiotic-like onset. IBS stool supernatants can sensitize mouse colonic afferent nerves via both histamine and proteases. However, it is unknown if stool supernatants from the two IBS-D subgroups modulate the excitability of nociceptive neurons via different neuroactive mediators Aims To evaluate whether there are differences in neuroactive mediators within stool supernatants from subgroups of IBS-D patients that can modulate the excitability of nociceptive neurons. Methods Stool samples from healthy control (HC) (N=5) and IBS-D patients with a dysbiotic (N=7) or non-dysbiotic-like (N=7) onset, was homogenized with Krebs solution and filtered. Proteolytic activity was assessed using casein as a substrate with and without protease inhibitors. Histamine was quantified by ELISA. DRG neurons from C57BL/6 mice were incubated overnight or acutely (30 min) with stool supernatants. Some neurons were pre-incubated with PAR2 (GB83, 10 μM) or H1R (pyrilamine, 1μM) antagonists prior to supernatant incubation. Changes in neuronal excitability were assessed with perforated patch-clamp by measuring the rheobase (current that elicits an action potential). Results Proteolytic activity in dysbiotic-like (57.9 U/μg, p Conclusions Proteases in stool supernatants from IBS-D patients increase neuronal excitability but only those with a history of dysbiotic like onset acutely increase neuronal excitability through H1 receptors. These findings suggest that stool supernatants from subgroups of IBS-D may modulate nociceptor excitability via different mechanisms. Funding Agencies CIHRAmerican Neurogastroenterology and Motility Society
Databáze: OpenAIRE
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