Early oral nutrition improves postoperative ileus through the TRPA1/CCK1-R-mediated mast cell-nerve axis

Docosahexaenoic acid (DHA) promotes recovery from postoperative ileus and the repair of the injured intestinal barrier through mast cell-nerve crosstalk

The objective of this study was to investigate the neuroimmune mechanisms implicated in the enhancement of gastrointestinal function through the administration of oral DHA. Mast cell-deficient mice (KitW-sh) and C57BL/6 mice were used to establish postoperative ileus (POI) models. To further validate our findings, we conducted noncontact coculture experiments involving dorsal root ganglion (DRG) cells, bone marrow-derived mast cells (BMMCs) and T84 cells. Furthermore, the results obtained from investigations conducted on animals and cells were subsequently validated through clinical trials. The administration of oral DHA had ameliorative effects on intestinal barrier injury and postoperative ileus. In a mechanistic manner, the anti-inflammatory effect of DHA was achieved through the activation of transient receptor potential ankyrin 1 (TRPA1) on DRG cells, resulting in the stabilization of mast cells and increasing interleukin 10 (IL-10) secretion in mast cells. Furthermore, the activation of the pro-repair WNT1-inducible signaling protein 1 (WISP-1) signaling pathways by mast cell-derived IL-10 resulted in an enhancement of the intestinal barrier integrity. The current study demonstrated that the neuroimmune interaction between mast cells and nerves played a crucial role in the process of oral DHA improving the intestinal barrier integrity of POI, which further triggered the activation of CREB/WISP-1 signaling in intestinal mucosal cells.

Butyrate promotes visceral hypersensitivity in IBS model via mast cell-derived DRG neuron lincRNA-01028-PKC-TRPV1 pathway

Emerging evidence indicates that gut dysbiosis is involved in the pathogenesis of visceral hypersensitivity (VH). However, how gut microbiota contributes to the development of VH is unknown. Here, we sought to examine the signal transduction pathways from gut to dorsal root ganglion (DRG) responsible for this. Therefore, abdominal withdrawal reflex (AWR) scores, fecal output, fecal water content, and total gastrointestinal transit time (TGITT) were assessed in Con rats, VH rats, rats treated with NaB, and VH rats treated with VSL#3. Fecal microbiota and its metabolite (short-chain fatty acids, SCFAs), mast cell degranulation in colon, lincRNA-01028, miR-143, and protease kinase C (PKC) and TRPV1 expression in DRGs were further detected. VH rats showed an increased fecal water content, a shortened TGITT, an increased abundance of Clostridium sensu stricto 1 and increased butyrate in fecal samples, an increased mast cell degranulation, an increased expression of lincRNA-01028, PKC, and TRPV1, and a decreased expression of miR-143 in DRGs compared with control rats, which could be restored by the application of probiotic VSL#3. The above-mentioned detection in rats treated with butyrate was similar to that of VH rats. We further confirm whether butyrate sensitized DRG neurons by a lincRNA-01028, miR-143, and PKC-dependent mechanism via mast cell in vitro. In co-cultures, MCs treated with butyrate elicited a higher TRPV1 current, a higher expression of lincRNA-01028, PKC, and a lower expression of miR-143 in DRG neurons, which could be inhibited by a lincRNA-01028 inhibitor. These findings indicate that butyrate promotes visceral hypersensitivity via mast cell-derived DRG neuron lincRNA-01028-PKC-TRPV1 pathway.IMPORTANCEIrritable bowel syndrome (IBS), characterized by visceral hypersensitivity, is a common gastrointestinal dysfunction syndrome. Although the gut microbiota plays a role in the pathogenesis and treatment of irritable bowel syndrome (IBS), the possible underlying mechanisms are unclear. Therefore, it is of critical importance to determine the signal transduction pathways from gut to DRG responsible for this in vitro and in vivo assay. This study demonstrated that butyrate sensitized TRPV1 in DRG neurons via mast cells in vivo and in vitro by a lincRNA-01028, miR-143, and PKC-dependent mechanism. VH rats similarly showed an increased abundance of Clostridium sensu stricto 1, an increased fecal butyrate, an increased mast cell degranulation, and increased expression of TRPV1 compared with control rats, which could be restored by the application of VSL#3. In conclusion, butyrate produced by the altered intestinal microbiota is associated with increased VH.

Nutrition in intestinal transplantation: centre stage or supporting act?

PURPOSE OF REVIEW

Intestinal transplantation (ITx), whether isolated or combined with other organs, is now a valid treatment option in some patients with chronic intestinal failure or extensive venous mesenteric thrombosis. The aim in these patients is not only to restore nutritional autonomy, but also to minimize the risk of complications, both short and long term. Despite parenteral nutrition playing a central part in the management of intestinal failure patients, there are little data about the perioperative and postoperative nutritional management of ITx patients, due to small patient populations per centre. In this review, we collected the scientific data available to date.

RECENT FINDINGS

In this review, we will bundle the limited scientific information about diet after intestinal and multivisceral transplantation combined with recommendations from our own clinical practice in 28 ITx patients in University Hospitals Leuven, Belgium. We will discuss the immediate preoperative period, surgical complications necessitating dietary interventions and the late postoperative phase in a stable outpatient transplant recipient.

SUMMARY

Although no specific research has been done in the field of ITx, we can extrapolate some findings from other solid organ transplants. Prehabilitation might prove to be of importance; Preserving kidney and liver function in the pretransplant period should be pursued. Transition from parenteral to enteral and oral nutrition can be complex due to inherent surgical procedures and possible complications. Ultimately, the goal is to give patients nutritional autonomy, while also minimizing the risk of foodborne infections by teaching patients well tolerated food practices.

Molecular and cellular mechanisms underlying postoperative paralytic ileus by various immune cell types

Postoperative ileus (POI) is a well-known complication following gut manipulation or surgical trauma, leading to an impaired gut motility and prolonged postoperative recovery time. Few current therapeutic strategies can prevent POI, and this disorder remains to be a major clinical challenge for patients undergoing surgery. Comprehensive understanding of cellular and molecular mechanisms related to the pathogenesis of POI stimulates the discovery of more promising targets for treatment. POI is closely associated with a series of inflammatory events within the bowel wall, and as key components of inflammatory mechanisms, different types of immune cells, including macrophages, dendritic cells, and T lymphocytes, play significant roles during the development of POI. A variety of immune cells are recruited into the manipulation sites after surgery, contributing to early inflammatory events or impaired gut motility. Our review intends to summarize the specific relationship between different immune cells and POI, mainly focusing on the relevant mechanisms underlying this disorder.

Electroacupuncture versus sham electroacupuncture in the treatment of postoperative ileus after laparoscopic surgery for colorectal cancer: study protocol for a multicentre, randomised, sham-controlled trial

INTRODUCTION

Postoperative ileus (POI) is an inevitable complication of almost all abdominal surgeries, which results in prolonged hospitalisation and increased healthcare costs. Various treatment strategies have been developed for POI but with limited success. Electroacupuncture (EA) might be a potential therapy for POI. However, evidence from rigorous trials that evaluated the effectiveness of EA for POI is limited. Thus, the aim of this study was to examine whether EA can safely reduce the time to the first defecation after laparoscopic surgery in patients with POI.

METHODS AND ANALYSIS

This multicentre randomised sham-controlled trial will be conducted in four hospitals in China. A total of 248 eligible participants with colorectal cancer who will undergo laparoscopic surgery will be randomly allocated to an EA group and a sham EA group in a 1:1 ratio. Treatment will be performed starting on postoperative day 1 and continued for four consecutive days, once per day. If the participant is discharged within 4 days after surgery, the treatment will cease on the day of discharge. The primary outcome will be the time to first defecation. The secondary outcome measures will include time to first flatus, tolerability of semiliquid and solid food, length of postoperative hospital stay, postoperative nausea and vomiting, abdominal distension, postoperative pain, postoperative analgesic, time to first ambulation, blinding assessment, credibility and expectancy and readmission rate.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the Ethics Committee of Beijing University of Chinese Medicine (number 2020BZHYLL0116) and the institutional review board of each hospital. The results will be disseminated through peer-reviewed publications. This study protocol (V.3.0, 6 March 2020) involves human participants and was approved by the ethics committees of Beijing University of Chinese Medicine (number 2020BZHYLL0116), Beijing Friendship Hospital Affiliated to Capital Medical University (number 2020-P2-069-01), Beijing Chao-Yang Hospital Affiliated to Capital Medical University (number 2020-3-11-2), National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College (number 20/163-2359), and the Affiliated Hospital of Qingdao University (number QYFYKYLL711311920). The participants gave informed consent to participate in the study before taking part.

TRIAL REGISTRATION NUMBER

ChiCTR2000038444.

Neuro-innate immune interactions in gut mucosal immunity

The gastrointestinal (GI) tract performs a set of vital physiological functions related to food and water consumption. To help regulate these complex physiological processes, the GI tract is innervated by extensive neural networks. The GI tract also serves as the largest immune organ aimed to protect hosts from harmful microbes and toxins ingested with food. It emerges that the enteric nervous and immune systems are highly integrated to optimize digestion while reinforcing immune protection. In this review, we will discuss key cellular players involved in the neuro-immune interactions within the GI mucosa with the focus on the recently uncovered neural pathways that regulate mucosal immunity in a context relevant to GI health and disease.

Neurotransmitter and neuropeptide regulation of mast cell function: a systematic review

The existence of the neural control of mast cell functions has long been proposed. Mast cells (MCs) are localized in association with the peripheral nervous system (PNS) and the brain, where they are closely aligned, anatomically and functionally, with neurons and neuronal processes throughout the body. They express receptors for and are regulated by various neurotransmitters, neuropeptides, and other neuromodulators. Consequently, modulation provided by these neurotransmitters and neuromodulators allows neural control of MC functions and involvement in the pathogenesis of mast cell–related disease states. Recently, the roles of individual neurotransmitters and neuropeptides in regulating mast cell actions have been investigated extensively. This review offers a systematic review of recent advances in our understanding of the contributions of neurotransmitters and neuropeptides to mast cell activation and the pathological implications of this regulation on mast cell–related disease states, though the full extent to which such control influences health and disease is still unclear, and a complete understanding of the mechanisms underlying the control is lacking. Future validation of animal and in vitro models also is needed, which incorporates the integration of microenvironment-specific influences and the complex, multifaceted cross-talk between mast cells and various neural signals. Moreover, new biological agents directed against neurotransmitter receptors on mast cells that can be used for therapeutic intervention need to be more specific, which will reduce their ability to support inflammatory responses and enhance their potential roles in protecting against mast cell–related pathogenesis.

Postoperative Ileus and Postoperative Gastrointestinal Tract Dysfunction: Pathogenic Mechanisms and Novel Treatment Strategies Beyond Colorectal Enhanced Recovery After Surgery Protocols

Postoperative ileus (POI) and postoperative gastrointestinal tract dysfunction (POGD) are well-known complications affecting patients undergoing intestinal surgery. GI symptoms include nausea, vomiting, pain, abdominal distention, bloating, and constipation. These iatrogenic disorders are associated with extended hospitalizations, increased morbidity, and health care costs into the billions and current therapeutic strategies are limited. This is a narrative review focused on recent concepts in the pathogenesis of POI and POGD, pipeline drugs or approaches to treatment. Mechanisms, cellular targets and pathways implicated in the pathogenesis include gut surgical manipulation and surgical trauma, neuroinflammation, reactive enteric glia, macrophages, mast cells, monocytes, neutrophils and ICC's. The precise interactions between immune, inflammatory, neural and glial cells are not well understood. Reactive enteric glial cells are an emerging therapeutic target that is under intense investigation for enteric neuropathies, GI dysmotility and POI. Our review emphasizes current therapeutic strategies, starting with the implementation of colorectal enhanced recovery after surgery protocols to protect against POI and POGD. However, despite colorectal enhanced recovery after surgery, it remains a significant medical problem and burden on the healthcare system. Over 100 pipeline drugs or treatments are listed in Clin.Trials.gov. These include 5HT4R agonists (Prucalopride and TAK 954), vagus nerve stimulation of the ENS-macrophage nAChR cholinergic pathway, acupuncture, herbal medications, peripheral acting opioid antagonists (Alvimopen, Methlnaltexone, Naldemedine), anti-bloating/flatulence drugs (Simethiocone), a ghreline prokinetic agonist (Ulimovelin), drinking coffee, and nicotine chewing gum. A better understanding of the pathogenic mechanisms for short and long-term outcomes is necessary before we can develop better prophylactic and treatment strategies.

MiR-216a-5p alleviates chronic constriction injury-induced neuropathic pain in rats by targeting KDM3A and inactivating Wnt/β-catenin signaling pathway

Neuropathic pain is a devastating disease and exists tolerance to current available analgesics. MicroRNAs were reported to be involved in the regulation of neuropathic pain, but the biological role of miR-216a-5p in neuropathic pain remains unclear. In this study, we constructed a CCI rat model of neuropathic pain. Our results showed that the expression of miR-216a-5p was downregulated in CCI rats, and mechanical allodynia and thermal hyperalgesia in CCI rats were improved by miR-216a-5p overexpression, suggesting that miR-216a-5p overexpression alleviated neuropathic pain. Moreover, ELISA showed that miR-216a-5p overexpression inhibited concentration and mRNA expression of IL-6, TNF-α and IL-1β as well as suppressed microglial infiltration, indicating that miR-216a-5p overexpression inhibited neuroinflammation. Besides, we found that miR-216a-5p upregulation inactivated the Wnt/β-catenin signaling pathway. Furthermore, KDM3A was the downstream target of miR-216a-5p and KDM3A knockdown attenuated neuropathic pain. Finally, through rescue assay, we found that KDM3A countervailed miR-216a-5p mediated regulation of neuropathic pain via the Wnt/β-catenin signaling pathway. To sum up, our study confirmed that miR-216a-5p alleviated neuropathic pain in rats by targeting KDM3A and inactivating the Wnt/β-catenin signaling pathway, which may open a new and useful way for treatment of neuropathic pain.