Electroacupuncture Accelerates the Delayed Intestinal Transit in POI by Suppressing M1 Like Muscularis Macrophages and IL6 Secretion

Abstract

Background: Electroacupuncture (EA) at ST-36 could accelerate the delayed gastrointestinal (GI) motility in many GI motility dysfunction models, but the definite effect and mechanisms are unclear. In this study, We intended to investigate the effects of EA on intestinal manipulation (IM) mice model and involved mechanisms. Methods: Male C57BL/6 mice were randomized into five groups: normal control, intestinal manipulation (IM), IM with sham EA (SEA), IM with high-frequency EA (HEA) and IM with low-frequency EA (LEA). The GI transit was evaluated. The infiltration of muscularis macrophages (MMφ) and its phenotype were analysed with flow cytometry. Magnetic-activated cell sorting was applied to isolate MMφ, and the relationship between the MMφ and interstitial cells of Cajal (ICCs) was further investigated. Results: (1) Compared with the IM group, HEA and LEA attenuated the delayed intestinal transit. (2) Both the HEA and LEA obviously reduced the MMφ and supressed the M1 activation of the MMφ in the ileum. (3) EA restored the disrupted ICC networks through inhibiting the release of IL6 by the MMφ. Conclusion: (1)EA at acupoint ST-36 could accelerate the delayed intestinal transit in the IM murine model by restoring the ICC networks. (2)EA protected the ICCs through reducing the MMφ, inhibiting its M1 polarization and its IL6 secretion. Funding Statement: The work was supported by grants from the National Natural Science Foundation of China (nos. 81570488; nos. 81770536). Declaration of Interests: The authors declare they have no conflict interests. Ethics Approval Statement: This study was carried out in accordance with the principles of the Guide for the Care and Use of Laboratory Animals of Tongji Medical College, the Committee of Experimental Animals of Tongji Medical College of Huazhong University of Science and Technology.