Identification of human herpes virus 1 encoded microRNAs in biopsy samples of lower esophageal sphincter muscle during per-oral endoscopic myotomy for esophageal achalasia.

Esophageal achalasia is a rare chronic debilitating disorder characterized by incomplete lower esophageal sphincter (LES) relaxation and abnormal peristalsis due to myenteric plexus degeneration. Although complex interactions among immunity, viruses and inheritance have been proposed, its causes remain unknown. MicroRNAs (miRs) play crucial roles in regulation of gene expression during pathophysiological processes. Certain viruses representing herpes simplex virus (HSV) encode miRs derived from their own genomes. For underlying relation of miRNAs to achalasia, we analyzed miRNAs expression profile using biopsy samples obtained from LES muscle during per-oral endoscopic myotomy (POEM). Peroral LES muscle biopsy sampling was uneventfully performed in case series of achalasia. Control biopsy tissues were also obtained from LES muscle of patients without symptoms relating to abnormal esophageal motility, whose esophago-gastric junction was surgically excised. RNA was extracted from biopsy specimens and analyzed using a microarray. Differentially expressed miRNAs in achalasia patients compared to controls were identified and analyzed using reverse transcription quantitative polymerase chain reaction. The HSV-1-derived hsv1-miR-H1 and -H18 was significantly overexpressed in achalasia cohorts compared to controls. Correlations between the viral miRs' expression levels and the patients' clinical characteristics including achalasia morphologic type, dilatation grading, and disease duration were not identified. Further studies with larger sample size are needed to replicate the current heuristic identification of the neurotropic viral miRs and unraveling their functional significance provides new insight linking to neurodegenerative etiology in achalasia. This article is protected by copyright. All rights reserved.