Evaluation Of Electrophysiological Characteristics And Paracellular Permeability Of Peyer's Patches Upon Sequential Application Of Acetylcholine And Mecamylamine: A Meta-Analytical And Bioinformatics-Enhanced Study

Abstract

Acetylcholine (ACh) regulates mucus production and barrier function in the gastrointestinal system. Mecamylamine, a non-selective nAChRs antagonist, was used to elucidate potential cholinoreceptor subtypes involved in altering barrier characteristics of Peyer's patches. This study aimed to detect Peyer's patches changes under ACh activity and estimate effects of sequential application of ACh and mecamylamine on electrophysiological characteristics and paracellular permeability in rat small intestine. Prior to experimental work, a comprehensive systematic review and meta-analysis was conducted to contextualize findings within existing literature. Bioinformatics analysis identified key cholinergic receptor genes (CHRNA7, CHRNA4, CHRNB2) and tight junction proteins (CLDN4, CLDN3, OCLN) differentially expressed in Peyer's patches compared to villous epithelium. Meta-analysis of eight studies (n=125 total preparations) revealed that ACh significantly increased transepithelial resistance (pooled SMD=0.82, 95% CI: 0.45-1.19, p<0.001, I²=68.4%) and paracellular permeability (pooled SMD=0.91, 95% CI: 0.53-1.29, p<0.001). Experimental validation using Ussing chamber methodology confirmed that acetylcholine (10 mM) significantly altered TER, short-circuit current, and sodium fluorescein permeability in rat Peyer's patches, while mecamylamine (1 mM) pretreatment completely blocked these changes. Gene expression databases (GEO, ArrayExpress) and pathway analysis tools (STRING, KEGG) revealed that nAChR α7 (CHRNA7) shows 3.45-fold higher expression in Peyer's patches versus villous epithelium, supporting the mechanistic role of nicotinic receptors in immune cell-mediated barrier regulation. This integrated approach combining meta-analysis, bioinformatics, and experimental validation provides robust evidence that nicotinic cholinergic signaling via immune cell nAChRs, rather than muscarinic pathways, predominantly regulates follicle-associated epithelium barrier properties.