Sacral neuromodulation for refractory ulcerative colitis: safety and efficacy in a prospective observational series of eight patients.

PURPOSE: Ulcerative colitis (UC) treatment is mainly based on immunosuppressive therapy. As anti-inflammatory effects of sacral neuromodulation (SNM) have been previously reported in animal models, we conducted a pilot study aimed at assessing clinical, biological, and endoscopic response but also safety of SNM use in UC refractory to medical therapy. METHODS: Adult patients with histologically proven UC resistant to immunosuppressive therapy were invited to enroll in the study. Primary outcome was the rate of UC remission (UCDAI score ≤ 2, without any criteria > 1) at 8 weeks (W8). Secondary outcomes were biological and endoscopic response also evaluated at W8 and W16. Subsequently, every patient was followed every 6 months. Adverse events were prospectively collected for safety assessment during the follow-up. RESULTS: Eight patients, with mean age 47 years old, suffering from UC for 2-13 years were included. There were no complications in relation to SNM procedure. The acceptance of the device was excellent in all patients. Clinical and endoscopic remission was obtained at W8 in one patient (12.5%) and three other patients (37.5%) were responders at W16. At review (mean follow-up of 4 years), two patients (25%) were in remission and two (25%) were responders. CONCLUSION: SNM application is safe in patients suffering from refractory UC. Effects on disease activity were mainly observed after 16 weeks. Larger prospective studies are mandatory, but SNM could be a way to reinforce medical therapy and reduce the use of immunosuppressive drugs.

Tumor cells hijack enteric glia to activate colon cancer stem cells and stimulate tumorigenesis.

BACKGROUND: Colon cancer stem cells (CSCs), considered responsible for tumor initiation and cancer relapse, are constantly exposed to regulatory cues emanating from neighboring cells present in the tumor microenvironment. Among these cells are enteric glial cells (EGCs) that are potent regulators of the epithelium functions in a healthy intestine. However, whether EGCs impact CSC-driven tumorigenesis remains unknown. METHODS: Impact of human EGC primary cultures or a non-transformed EGC line on CSCs isolated from human primary colon adenocarcinomas or colon cancer cell lines with different p53, MMR system and stemness status was determined using murine xenograft models and 3D co-culture systems. Supernatants of patient-matched human primary colon adenocarcinomas and non-adjacent healthy mucosa were used to mimic tumor versus healthy mucosa secretomes and compare their effects on EGCs. FINDINGS: Our data show that EGCs stimulate CSC expansion and ability to give rise to tumors via paracrine signaling. Importantly, only EGCs that were pre-activated by tumor epithelial cell-derived soluble factors increased CSC tumorigenicity. Pharmacological inhibition of PGE2 biosynthesis in EGCs or IL-1 knockdown in tumor epithelial cells prevented EGC acquisition of a pro-tumorigenic phenotype. Inhibition of PGE2 receptor EP4 and EGFR in CSCs inhibited the effects of tumor-activated EGCs. INTERPRETATION: Altogether, our results show that EGCs, once activated by the tumor, acquire a pro-tumorigenic phenotype and stimulate CSC-driven tumorigenesis via a PGE2/EP4/EGFR-dependent pathway. FUNDING: This work was supported by grants from the French National Cancer Institute, La Ligue contre le Cancer, the 'Région des Pays de la Loire' and the UNC Lineberger Comprehensive Cancer Center.

[From human pluripotent stem cells to custom-made intestinal organoids]. / Organoïdes (2) - Façonner l'intestin à partir des cellules souches pluripotentes humaines.

The study of gut diseases is often limited by the access to human biological tissues and animal models that do not faithfully mimic the human pathologies. In this context, the development of intestinal organoids from human pluripotent stem cells is paving the way of gastrointestinal physiology and digestive disease study. In this review, we recall the embryonic development of the digestive tract and its translation to human pluripotent stem cell differentiation. We also present the different types of intestinal organoids that can be generated, as well as their applications in research.

TITLE: Façonner l'intestin à partir des cellules souches pluripotentes humaines. ABSTRACT: L'étude des maladies digestives est parfois limitée par l'accès aux tissus de patients et les modèles précliniques ne sont pas toujours fidèles aux pathologies observées chez l'homme. Dans ce contexte, le développement d'organoïdes intestinaux à partir de cellules souches pluripotentes humaines représente une avancée importante dans l'étude des processus physiologiques et des pathologies digestives. Dans cette revue, nous rappelons les étapes majeures du développement du tractus digestif chez l'homme et décrivons le rationnel de la différenciation dirigée des cellules souches pluripotentes humaines. Nous faisons également un état des lieux sur les différents types d'organoïdes intestinaux existants et leurs applications en recherche fondamentale et préclinique. Enfin, nous discutons des opportunités offertes par les organoïdes intestinaux humains dans un contexte de médecine de précision et de médecine réparatrice.

Basal and Spasmolytic Effects of a Hydroethanolic Leaf Extract of Melissa officinalis L. on Intestinal Motility: An Ex Vivo Study.

Melissa officinalis L. (lemon balm) has been used for decades with symptomatic benefits in patients with digestive disorders. However, very little is known on the effects of M. officinalis on the gastrointestinal (GI) tract. In this study, the basal and spasmolytic properties of a hydroethanolic leaf extract (HLE) of M. officinalis were assessed ex vivo on different segments of the GI tract of mice after phytochemical characterization of the extract. M. officinalis HLE had site- and dose-dependent effects on the contractile activity of the GI tract, the motility response being impacted in the jejunum and ileum but not in the antrum and colon. The observed effects could be caused by the phenolic compounds (mainly rosmarinic acid) detected in the extract.

Perioperative Transcutaneous Tibial Nerve Stimulation to Reduce Postoperative Ileus After Colorectal Resection: A Pilot Study.

BACKGROUND: Postoperative ileus involves an inflammatory pathway characterized by an increase of inflammation mediators in the colon wall; this could probably be prevented by sacral nerve neuromodulation. The posterior tibial nerve can be stimulated electrically to mimic neuromodulation. OBJECTIVE: The aims of this study were to assess the efficacy of transcutaneous posterior tibial nerve stimulation in reducing the delay in GI motility recovery, to assess the safety of posterior tibial nerve stimulation in a perioperative setting, and to assess the efficacy of posterior tibial nerve stimulation in reducing the occurrence of postoperative ileus. DESIGN: This was a preliminary randomized controlled study. SETTINGS: This study was conducted in 1 academic hospital in France. PATIENTS: Forty patients undergoing an elective colectomy were included and randomly assigned into 2 groups, posterior tibial nerve stimulation or placebo, according to the side of colectomy and the surgical access size. INTERVENTION: Perioperative posterior tibial nerve stimulation or placebo was performed 3 times per day according to the randomly assigned group. MAIN OUTCOME MEASURES: Delay in GI motility recovery (passage of stool and tolerance of solid food) was measured. RESULTS: Of the 40 patients included, 34 were included in the final analysis, in which 2 patients in the placebo group were allocated the incorrect device. The 6 other patients were secondarily excluded because of protocol deviation. In the intention-to-treat analysis, the mean delay in GI motility recovery was 3.6 and 3.11 days (in the placebo and tibial nerve stimulation groups; p = 0.60). Occurrence of postoperative ileus was not significantly higher in the placebo group (35.3% vs 17.6%; p = 0.42). In the per-protocol analysis, we observed the same trends except for the occurrence of postoperative ileus, which was significantly higher in the placebo group (p = 0.045). Tolerance to posterior tibial nerve stimulation was good, and all of the patients completed the protocol. LIMITATIONS: The amplitude of stimulation is set according to patient sensation, so some patients could have been aware of their group. In addition there were some inherent limitations because of the preliminary nature of the study and several deviations from the protocol. CONCLUSIONS: Posterior tibial nerve stimulation was safe in a perioperative setting and had a potential effect on GI motility recovery. The results of this study will be useful for sample size calculations in a larger prospective randomized trial. See Video Abstract at http://links.lww.com/DCR/A708.

Sacral nerve stimulation enhances early intestinal mucosal repair following mucosal injury in a pig model.

KEY POINTS: Reducing intestinal epithelial barrier (IEB) dysfunctions is recognized as being of major therapeutic interest for various intestinal disorders. Sacral nerve stimulation (SNS) is known to reduce IEB permeability. Here, we report in a pig model that SNS enhances morphological and functional recovery of IEB following mucosal injury induced via 2,4,6-trinitrobenzenesulfonic acid. These effects are associated with an increased expression of tight junction proteins such as ZO-1 and FAK. These results establish that SNS enhances intestinal barrier repair in acute mucosal injury. They further set the scientific basis for future use of SNS as a complementary or alternative therapeutic option for the treatment of gut disorders with IEB dysfunctions such as inflammatory bowel diseases or irritable bowel syndrome. ABSTRACT: Intestinal epithelial barrier (IEB) dysfunctions, such as increased permeability or altered healing, are central to intestinal disorders. Sacral nerve stimulation (SNS) is known to reduce IEB permeability, but its ability to modulate IEB repair remains unknown. This study aimed to characterize the impact of SNS on mucosal repair following 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced lesions. Six pigs were stimulated by SNS 3 h prior to and 3 h after TNBS enema, while sham animals (n = 8) were not stimulated. The impact of SNS on mucosal changes was evaluated by combining in vivo imaging, histological and functional methods. Biochemical and transcriptomic approaches were used to analyse the IEB and mucosal inflammatory response. We observed that SNS enhanced the recovery from TNBS-induced increase in transcellular permeability. At 24 h, TNBS-induced alterations of mucosal morphology were significantly less in SNS compared with sham animals. SNS reduced TNBS-induced changes in ZO-1 expression and its epithelial pericellular distribution, and also increased pFAK/FAK expression compared with sham. Interestingly, SNS increased the mucosal density of neutrophils, which was correlated with an increase in trypsin and TGF-ß1 levels compared with sham. Finally, SNS prevented the TNBS-induced increases in IL-1ß and IL-4 over time that were observed with sham treatment. In conclusion, our results show that SNS enhances mucosal repair following injury. This study highlights novel mechanisms of action of SNS and identifies SNS as a new therapy for diseases with IEB repair disorders.

Improvement of Refractory Ulcerative Proctitis With Sacral Nerve Stimulation.

BACKGROUND AND AIMS: Sacral nerve stimulation (SNS) is recognized for its efficiency and safety for anal incontinence, preventing high morbidity. Evidence from the literature suggests extending SNS to diseases associated with problems of intestinal barrier permeability. The aim of this study was to highlight clinical evidence of the beneficial impact of SNS in a refractory proctitis case report. MATERIALS AND METHODS: A permanent SNS was performed successfully in a patient with proctitis after implantation of the neuromodulator. Despite immunosuppressive drugs, the patient was experiencing mucus and blood discharge, pain, and fecal incontinence. To relieve fecal incontinence, SNS was tested without modification of medications. Disease activity, endoscopic and histologic score, ex vivo barrier permeability, expression of inflammatory cytokines (transforming growth factor-ß, tumor necrosis factor α, Interleukin-6, Interleukin-8), and junctional proteins (ZO-1, claudin-1, occludin) were assessed before and after SNS to observe the impact of SNS other than for incontinence. RESULTS: After a 3-week period of temporary stimulation, the patient experienced significant improvement with a decrease in fecal incontinence and disease activity scores. Both endoscopic and histologic scores showed improvement. The rectal barrier permeability decreased with SNS, whereas junctional protein mRNA expression transiently increased. Clinical and histologic improvement was sustained over time. After 18 months of permanent stimulation, the patient remained improved by SNS. CONCLUSION: This work demonstrates the relevance to explore further indications of SNS beyond fecal incontinence.

Butyrate enemas enhance both cholinergic and nitrergic phenotype of myenteric neurons and neuromuscular transmission in newborn rat colon.

Postnatal changes in the enteric nervous system (ENS) are involved in the establishment of colonic motility. In adult rats, butyrate induced neuroplastic changes in the ENS, leading to enhanced colonic motility. Whether butyrate can induce similar changes during the postnatal period remains unknown. Enemas (Na-butyrate) were performed daily in rat pups between postnatal day (PND) 7 and PND 17. Effects of butyrate were evaluated on morphological and histological parameters in the distal colon at PND 21. The neurochemical phenotype of colonic submucosal and myenteric neurons was analyzed using antibodies against Hu, choline acetyltransferase (ChAT), and neuronal nitric oxide synthase (nNOS). Colonic motility and neuromuscular transmission was assessed in vivo and ex vivo. Butyrate (2.5 mM) enemas had no impact on pup growth and histological parameters compared with control. Butyrate did not modify the number of Hu-immunoreactive (IR) neurons per ganglia. A significant increase in the proportion (per Hu-IR neurons) of nNOS-IR myenteric and submucosal neurons and ChAT-IR myenteric neurons was observed in the distal colon after butyrate enemas compared with control. In addition, butyrate induced a significant increase in both nitrergic and cholinergic components of the neuromuscular transmission compared with control. Finally, butyrate increased distal colonic transit time compared with control. We concluded that butyrate enemas induced neuroplastic changes in myenteric and submucosal neurons, leading to changes in gastrointestinal functions. Our results support exploration of butyrate as potential therapy for motility disorders in preterm infants with delayed maturation of the ENS.

Enteric glia protect against Shigella flexneri invasion in intestinal epithelial cells: a role for S-nitrosoglutathione.

BACKGROUND: Enteric glial cells (EGCs) are important regulators of intestinal epithelial barrier (IEB) functions. EGC-derived S-nitrosoglutathione (GSNO) has been shown to regulate IEB permeability. Whether EGCs and GSNO protect the IEB during infectious insult by pathogens such as Shigella flexneri is not known. METHODS: S flexneri effects were characterised using in vitro coculture models of Caco-2 cells and EGCs (or GSNO), ex vivo human colonic mucosa, and in vivo ligated rabbit intestinal loops. The effect of EGCs on S flexneri-induced changes in the invasion area and the inflammatory response were analysed by combining immunohistochemical, ELISA and PCR methods. Expression of small G-proteins was analysed by western blot. Expression of ZO-1 and localisation of bacteria were analysed by fluorescence microscopy. RESULTS: EGCs significantly reduced barrier lesions and inflammatory response induced by S flexneri in Caco-2 monolayers. The EGC-mediated effects were reproduced by GSNO, but not by reduced glutathione, and pharmacological inhibition of pathways involved in GSNO synthesis reduced EGC protecting effects. Furthermore, expression of Cdc42 and phospho-PAK in Caco-2 monolayers was significantly reduced in the presence of EGCs or GSNO. In addition, changes in ZO-1 expression and distribution induced by S flexneri were prevented by EGCs and GSNO. Finally, GSNO reduced S flexneri-induced lesions of the IEB in human mucosal colonic explants and in a rabbit model of shigellosis. CONCLUSION: These results highlight a major protective function of EGCs and GSNO in the IEB against S flexneri attack. Consequently, this study lays the scientific basis for using GSNO to reduce barrier susceptibility to infectious or inflammatory challenge.