HUANG Yan, WU Luyi, ZHAO Jimeng, MA Zhe, FANG Zhengzheng, LIU Huirong, WU Huangan

(1. Shanghai Research Institute of Acupuncture and Meridian，Shanghai University of Traditional Chinese Medicine, Shanghai, China；2. Clinical college，Affiliated Yueyang Hospital of Shanghai University of Traditional Chinese Medicine, Shanghai, China)

Abstract: Objective: Recent studies have focused on the efficacy of herb-partitioned moxibustion (HM) in ulcerative  colitis  (UC)  patients  and  its  immune  regulatory  mechanism  in  UC  in  rats.  To  investigate  the mechanism of action of HM in UC, this study for the first time explored the mechanism of the effect of HM on dextran sulfate sodium (DSS)-induced UC from the miRNA perspective. Methods: Rats were randomly divided into 3 groups [normal control (NC) group, UC model (UC) group, and herb-partitioned moxibustion (UCHM) group]. The UC and UCHM groups were administered 4% DSS in their drinking water for 7 days to induce the UC rat model; on day 8, the animals were administered 1% DSS in water for 7 days. Starting from day 8, the UCHM group received HM at the Tianshu points (bilateral, ST25) for 7 days. On day 15, colon tissues were collected under anesthesia with 2% pentobarbital sodium. The effect of HM at the ST25 points on UC in the rats was observed using general conditions, body weights, macroscopic colon injury scores, and microscopic histopathology scores. Two samples from each group were selected for total RNA extraction. The miRNA expression profile in the colon tissues was analyzed using small RNA-seqcombined with bioinformatics. Results: The body weights of the rats were decreased in the UC group. On day 14, the body weights of the rats in the UCHM group increased to a level similar to the weights in the NC group and were significantly higher than the weights in the UC group (P<0.001). The macroscopic colon injury scores and microscopic histopathology scores in the UC group both increased compared to the scores in the NC group (P<0.05). Both scores in the UCHM group decreased compared to the scores in the UC group (P<0.05). The UC group had 49 differentially expressed miRNAs in colon tissues compared to the NC group, of which 47  were  up-regulated  and  2  were  down-regulated.  The  UCHM  group  had  15  differentially  expressed miRNAs compared to the UC group, of which 13 were up-regulated and 2 were down-regulated. The changes in  miR-184  and  miR-490-5p  expression  levels  on  the  UC  pathological  status  were  reversed  by  HM intervention  at  the  ST25  points.  The  predicted  target  gene  pathways  of  these  2  miRNAs  were  closely associated with immune inflammation and carcinogenesis in UC. Validation using quantitative real-time polymerase  chain  reaction  (qRT-PCR)  showed  that  the  miR-184  and  miR-490-5p  expression  trend  was consistent with the sequencing results.  Conclusion:  HM at ST25 might regulate miR-184 and miR-490-5p expression, affect the transcription of inflammatory cytokines, regulate inflammatory signaling pathways, and attenuate inflammation and tissue injury in the colons of rats with DSS-induced UC.

Key  words:  Acupuncture  and  moxibustion,  Herb-partitioned  moxibustion,  Ulcerative  colitis,  miRNA expression profiles