Reduced expression of voltage-gated Kv11.1 (hERG) K(+) channels in aganglionic colon in Hirschsprung's disease

Differential mRNA expression in ileal and colonic biopsies in irritable bowel syndrome with diarrhea or constipation

Altered mucosal functions are documented in jejunal or colorectal mucosa from patients with irritable bowel syndrome (IBS). Our aim was to quantify ileal, ascending, and rectosigmoid colon mucosal expression of genes in IBS-diarrhea (D) and IBS-constipation (C). Forty-four patients with IBS-D, 30 with IBS-C, and 30 healthy volunteers underwent colonoscopic ileal, ascending, and rectosigmoid colon biopsies. Biopsies were stored in RNA_later at -80 °C, purified with on-column DNase, cDNA libraries prepared from 100-200 ng of total RNA, sequenced on Illumina NovaSeq 6000, and analyzed on Illumina's RTA version 3.4.4. Normalized mRNA expression was obtained using MAP-RSeq bioinformatics pipeline. Differential expressions in the groups (Log2-fold change) were measured using the bioinformatics package edgeR 2.6.2, corrected for false discovery rate (P_ADJ <0.05). There were 30 females with IBS-C and 31 females and 13 males with IBS-D. In IBS-D and IBS-C groups, there were differential expressions of 181 genes in ascending colon and 199 genes in rectosigmoid colon. The majority were gene upregulations in IBS-D with functions reflecting activation of inflammation genes, TRPV1 (visceral hypersensitivity) and neurotransmitters/receptors (specifically purinergic, GABA, and cannabinoid). Although gene differential expressions in the ascending and rectosigmoid colon mucosa of the two groups were different, the diverse upregulated genes involved immune functions, receptors, transmitters, ion channels, and transporters. Conversely, there was reduced expression of PI15 and PI16 genes that inhibit proteases. In patients with IBS-D and IBS-C, differential expressions of genes related to immune, transmitter, nociceptive, protease inhibition, channel, and transporter functions suggest opportunities to reverse the pathobiology and treat patients with IBS.NEW & NOTEWORTHY This study compares gene expression in mucosa of the terminal ileum, right colon, and left colon in patients with diarrhea- or constipation-predominant irritable bowel syndrome (IBS) and contrasts expression between these two disease entities and also between each entity and mucosa from healthy controls. The study shows there is differential expression of genes related to immune, transmitter, nociceptive, ion channel, and transporter functions, as well as reduced serine protease inhibition, in patients with IBS.

Modulation of Pacemaker Potentials in Murine Small Intestinal Interstitial Cells of Cajal by Gamisoyo-San, a Traditional Chinese Herbal Medicine

BACKGROUND

The Gamisoyo-san (GSS) has been used for -improving the gastrointestinal (GI) symptoms. The purpose of this study was to investigate the effects of GSS, a traditional Chinese herbal medicine, on the pacemaker potentials of mouse small intestinal interstitial cells of Cajal (ICCs).

METHODS

ICCs from the small intestines were dissociated and cultured. Whole-cell patch-clamp configuration was used to record pacemaker potentials and membrane currents.

RESULTS

GSS depolarized ICC pacemaker potentials in a dose-dependent manner. Pretreatment with 4-diphenylacetoxypiperidinium iodide completely inhibited GSS-induced pacemaker potential depolarizations. Intracellular GDP-β-S inhibited GSS-induced effects, and in the presence of U-73122, GSS-induced effects were inhibited. Also, GSS in the presence of a Ca2+-free solution or thapsigargin did not depolarize pacemaker potentials. However, in the presence of calphostin C, GSS slightly depolarized pacemaker potentials. Furthermore, GSS inhibited both transient receptor potential melastatin7 and Ca2+-activated Cl- channel (anoctamin1) currents.

CONCLUSION

GSS depolarized pacemaker potentials of ICCs via G protein and muscarinic M3 receptor signaling pathways and through internal or external Ca2+-, phospholipase C-, and protein kinase C-dependent and transient receptor potential melastatin 7-, and anoctamin 1-independent pathways. The study shows that GSS may regulate GI tract motility, suggesting that GSS could be a basis for developing novel prokinetic agents for treating GI motility dysfunctions.

Laparoscopic-assisted pull-through operation for Hirschsprung's disease: a systematic review and meta-analysis

PURPOSE

In the last two decades, laparoscopic-assisted pull-through (LAPT) has gained much popularity in the treatment of Hirschsprung's disease. The aim of this meta-analysis was to determine the long-term outcome of patients treated laparoscopically.

METHODS

A systematic literature-based search for relevant cohorts was performed using the terms "Hirschsprung's disease and Laparoscopy", "Laparoscopic-assisted pull-through outcome", "Laparoscopic-assisted Soave pull-through" "Laparoscopic-assisted Swenson pull-through" and Laparoscopic-assisted Duhamel pull-through. The relevant cohorts of laparoscopic operated HD were systematically searched for outcome regarding continence, constipation, secondary surgery related to the laparoscopic approach and enterocolitis. Pooled incidence rates and odds ratios (ORs) with 95 % confidence intervals (CI) were calculated using standardized statistical methodology.

RESULTS

Sixteen studies met defined inclusion criteria, reporting a total of 820 patients. All studies were retrospective case series, with variability in outcome assessment quality and length of follow-up. The median cohort size consisted of 28 patients (range 15-218). In the long-term follow-up, 97 patients (11.14 %) experienced constipation (OR 0.06, 95 % CI 0.05-0.08, p < 0.00001), 53 (6.46 %) incontinence/soiling (OR 0.01 95 % CI 0.01-0.01, p < 0.00001), 75 (9.14 %) recurrent enterocolitis (OR 0.02 95 % CI 0.01-0.02, p < 0.00001) and 69 (8.4 %) developed complications requiring secondary surgery (OR 0.01 95 % CI 0.01-0.02, p < 0.00001). Overall events in long-term follow-up occurred in 225 (27.5 %) patients (OR 0.24 95 % CI 0.20-0.30, p < 0.00001).

CONCLUSIONS

This meta-analysis shows that nearly one-third of the patients continue to have long-term bowel problems, such as constipation, soiling and recurrent enterocolitis following LAPT. Many patients treated by LAPT require secondary surgery. Large randomized studies with long-term follow-up are necessary to determine the difference in outcome between LAPT and completely transanal pull-through operation.