Interstitial cell network volume is reduced in the terminal bowel of ageing mice

Clinicopathological features and prognosis of colonic and rectal gastrointestinal stromal tumors: A propensity score matching analysis

Background

Colonic gastrointestinal stromal tumor (cGIST) and rectal gastrointestinal stromal tumor (rGIST) are two rare subtypes of gastrointestinal stromal tumor (GIST). The view that colonic and rectal carcinoma are different is generally accepted; however, whether there is a difference between cGIST and rGIST is still unknown. Here, we aimed to provide evidence for future clinical management and research by comparing the differences between the two types of GIST in the above-mentioned aspects.

Methods

Patients were enrolled from three medical centers in China and published literature was collected following the inclusion and exclusion criteria. Propensity score matching was used to eliminate differences between cohorts.

Results

Between cGIST and rGIST patients, significant differences were observed in age, tumor size, mitotic index, NIH risk category, growth pattern, and symptoms. Adjuvant therapy is used in a high proportion of cGIST patients, and neoadjuvant therapy is used in a high proportion of rGIST patients. Although local resection is the main surgical method in both cohorts, the proportion is higher in cGIST patients. The overall survival of rGIST patients was better than that of the cGIST patients before propensity score matching (PSM). Interestingly, no significant differences in prognosis were observed after PSM.

Conclusions

Although there were significant differences between cGIST and rGIST patients in baseline characteristics, clinicopathological features, treatment choice, and overall survival rate before PSM, no significant differences in long-term survival were observed between the two groups after PSM. In our study, there may be no differences in the tumor entity between cGIST and rGIST.

Arecoline hydrobromide enhances jejunum smooth muscle contractility via voltage-dependent potassium channels in W/Wv mice

Gastrointestinal motility was disturbed in W/Wv, which were lacking of interstitial cells of Cajal (ICC). In this study, we have investigated the role of arecoline hydrobromide (AH) on smooth muscle motility in the jejunum of W/Wv and wild-type (WT) mice. The jejunum tension was recorded by an isometric force transducer. Intracellular recording was used to identify whether AH affects slow wave and resting membrane potential (RMP) in vitro. The whole-cell patch clamp technique was used to explore the effects of AH on voltage-dependent potassium channels for jejunum smooth muscle cells. AH enhanced W/Wv and WT jejunum contractility in a dose-dependent manner. Atropine and nicardipine completely blocked the excitatory effect of AH in both W/Wv and WT. TEA did not reduce the effect of AH in WT, but was sufficient to block the excitatory effect of AH in W/Wv. AH significantly depolarized the RMP of jejunum cells in W/Wv and WT. After pretreatment with TEA, the RMP of jejunum cells indicated depolarization in W/Wv and WT, but subsequently perfused AH had no additional effect on RMP. AH inhibited the voltage-dependent K+ currents of acutely isolated mouse jejunum smooth muscle cells. Our study demonstrate that AH enhances the contraction activity of jejunum smooth muscle, an effect which is mediated by voltage-dependent potassium channels that acts to enhance the excitability of jejunum smooth muscle cells in mice.

Understanding the Biology of Human Interstitial Cells of Cajal in Gastrointestinal Motility

Millions of patients worldwide suffer from gastrointestinal (GI) motility disorders such as gastroparesis. These disorders typically include debilitating symptoms, such as chronic nausea and vomiting. As no cures are currently available, clinical care is limited to symptom management, while the underlying causes of impaired GI motility remain unaddressed. The efficient movement of contents through the GI tract is facilitated by peristalsis. These rhythmic slow waves of GI muscle contraction are mediated by several cell types, including smooth muscle cells, enteric neurons, telocytes, and specialised gut pacemaker cells called interstitial cells of Cajal (ICC). As ICC dysfunction or loss has been implicated in several GI motility disorders, ICC represent a potentially valuable therapeutic target. Due to their availability, murine ICC have been extensively studied at the molecular level using both normal and diseased GI tissue. In contrast, relatively little is known about the biology of human ICC or their involvement in GI disease pathogenesis. Here, we demonstrate human gastric tissue as a source of primary human cells with ICC phenotype. Further characterisation of these cells will provide new insights into human GI biology, with the potential for developing novel therapies to address the fundamental causes of GI dysmotility.

Lactobacillus plantarum KFY02 enhances the relieving effect of gardenoside on montmorillonite induced constipation in mice

Lactobacillus plantarum KFY02 (KFY02), isolated from naturally fermented milk yoghurt in Korla, Xinjiang, Northwest of China, showed gardenoside action for the intestinal regulation of constipated mice. Comparatively, the effects of KFY02 (0.5 × 108 CFU kg-1, by body weight (BW)), gardenoside (50 mg kg-1, BW), and KFY02 (0.5 × 108 CFU kg-1, BW) + gardenoside (50 mg kg-1, BW) on intestinal regulation in mice with montmorillonite-induced constipation were also studied. Enzyme linked immunoassay, hemotoxylin and eosin (H&E) staining, quantitative polymerase chain reaction (qPCR) assay and high performance liquid chromatography (HPLC) analysis were used for the study. Compared with the model group, KFY02 + genipin (combined group) increased the propelling rate of activated carbon in the small intestines of mice and accelerated the discharge of the first black stool in mice. At the same time, the combination group reduced the levels of motilin (MTL), substance P (SP) and endothelin-1 (ET-1) in the serum, and increased the somatostatin (SS), vasoactive intestinal peptide (VIP), acetylcholinesterase (AchE) and gastrin (Gastrin) levels in the serum, which made these parameters close to those of the normal group. Using qPCR analysis, it was observed that the combined group up-regulated the mRNA expression of endothelial nitric oxide synthase (eNOS), stem cell factor (SCF), stem cell factor receptor (c-Kit), glutathione (GSH), catalase and manganese-superoxide dismutase (Mn-SOD) and down-regulated the expression of inducible nitric oxide synthase (iNOS) and transient receptor potential vanilloid receptor 1 (TRPV1). The combination increased the Bacteroides and Akkermansia abundances and decreased the Firmicutes abundance in the feces of the constipated mice and decreased the Firmicutes/Bacteroides ratio. The expression of the above genes was similar to that of the normal group. The results indicate that KFY02 produced β-glucosidase to hydrolyze the gardenoside glycosidic bond to produce genipin and can effectively promote the regulation of gastrointestinal hormones and intestinal peristalsis and reduce oxidative tissue damage in constipated mice. This study also confirmed that KFY02 has similar relieving effects to gardenoside for constipation in mice.

Interstitial cell network volume is reduced in the terminal bowel of ageing mice

Ageing is associated with impaired neuromuscular function of the terminal gastrointestinal (GI) tract, which can result in chronic constipation, faecal impaction and incontinence. Interstitial cells of cajal (ICC) play an important role in regulation of intestinal smooth muscle contraction. However, changes in ICC volume with age in the terminal GI tract (the anal canal including the anal sphincter region and rectum) have not been studied. Here, the distribution, morphology and network volume of ICC in the terminal GI tract of 3‐ to 4‐month‐old and 26‐ to 28‐month‐old C57BL/6 mice were investigated. ICC were identified by immunofluorescence labelling of wholemount preparations with an antibody against c‐Kit. ICC network volume was measured by software‐based 3D volume rendering of confocal Z stacks. A significant reduction in ICC network volume per unit volume of muscle was measured in aged animals. No age‐associated change in ICC morphology was detected. The thickness of the circular muscle layer of the anal sphincter region and rectum increased with age, while that in the distal colon decreased. These results suggest that ageing is associated with a reduction in the network volume of ICC in the terminal GI tract, which may influence the normal function of these regions.