Upper esophageal sphincter abnormalities on high-resolution esophageal manometry and treatment response of type II achalasia.

BACKGROUND: Little is known about the clinical significance of upper esophageal sphincter (UES) motility disorders and their association with the treatment response of type II achalasia. None of the three versions of the Chicago Classification of Esophageal Motility Disorders has defined UES abnormality metrics or their function. UES abnormalities exist in some patients and indicate a clinically significant problem in patients with achalasia. AIM: To demonstrate the manometric differentiation on high-resolution esophageal manometry between subjects with abnormal UES and normal UES, and the association between UES type and the treatment response of type II achalasia. METHODS: In total, 498 consecutive patients referred for high-resolution esophageal manometry were analyzed retrospectively. The patients were divided into two groups, those with normal and abnormal UES function. UES parameters were analyzed after determining lower esophageal sphincter (LES) function. Patients with type II achalasia underwent pneumatic dilation for treatment. Using mixed model analyses, correlations between abnormal UES and treatment response were calculated among subjects with type II achalasia. RESULTS: Of the 498 consecutive patients, 246 (49.40%) were found to have UES abnormalities. Impaired relaxation alone was the most common UES abnormality (52.85%, n = 130). The incidence rate of type II achalasia was significantly higher in subjects with abnormal UES than those with normal UES (9.77% vs 2.58%, P = 0.01). After pneumatic dilation, LES resting pressure, LES integrated relaxation pressure, and UES residual pressure were significantly decreased (41.91 ± 9.20 vs 26.18 ± 13.08, 38.94 ± 10.28 vs 16.71 ± 5.65, and 11.18 ± 7.93 vs 5.35 ± 4.77, respectively, P < 0.05). According to the Eckardt score, subjects with type II achalasia and abnormal UES presented a significantly poorer treatment response than those with normal UES (83.33% vs 0.00%, P < 0.05). CONCLUSION: Impaired relaxation alone is the most common UES abnormality. The incidence of type II achalasia is associated with abnormal UES. Type II achalasia with abnormal UES has a poorer treatment response, which is a potentially prognostic indicator of treatment for this disease.

Epigenetic modification of TLE1 induce abnormal differentiation in diabetic mice intestinal epithelium.

The intestinal epithelium cells (IECs) in diabetes mellitus (DM) patients have been proven to be abnormally differentiated. During the differentiation of IECs, epigenetic modification acts as an important regulator. In this study, we aimed to examine the epigenetic alteration of Transducin-like Enhancer of Split 1 (TLE1), a multitask transcriptional co-repressor, contributing to the differentiation homeostasis in IECs of DM mice. The IECs of type 2 diabetic mice model were isolated and collected. Methylation states of whole genomic DNA promoter regions were investigated by microarray. Methylated-specific PCR was used to detect the methylation state of TLE1 promoter in DM mice IECs. The expression of TLE1, Hes1, and differentiated cell markers were measured through real-time PCR, Western blots, and immunohistochemistry; by transfection assay, TLE1 or Hes1 was independently down-regulated in intestinal epithelium cell line, IEC-6. Subsequent modulation on TLE1, Hes1, and differentiated intestinal cell markers were detected. Global gene promoter regions in DM intestinal epithelium were less methylated comparing to normal control. The expression of TLE1 was significantly increased via hypomethylated activation in DM mice IECs. Hes1 was significantly suppressed and the terminal cell markers abnormally expressed in DM mice IECs (P < 0.05). Inhibition or induction on the abundance of TLE1 in IEC-6 cell line resulted in the corresponding dysregulation of Hes1 and intestinal epithelium differentiation (P < 0.05). Demethylation of TLE1 promoter region activates the self-expression in diabetic mice IECs. Subsequently, TLE1, through the transcriptional suppression on expression of Hes1, contributes to the aberrant differentiation of IECs in DM mice.

Helicobacter pylori Infection Is Associated with Type 2 Diabetes, Not Type 1 Diabetes: An Updated Meta-Analysis.

BACKGROUND: Extragastric manifestations of Helicobacter pylori (H. pylori) infection have been reported in many diseases. However, there are still controversies about whether H. pylori infection is associated with diabetes mellitus (DM). This study was aimed at answering the question. METHODS: A systematic search of the literature from January 1996 to January 2016 was conducted in PubMed, Embase databases, Cochrane Library, Google Scholar, Wanfang Data, China national knowledge database, and SinoMed. Published studies reporting H. pylori infection in both DM and non-DM individuals were recruited. RESULTS: 79 studies with 57,397 individuals were included in this meta-analysis. The prevalence of H. pylori infection in DM group (54.9%) was significantly higher than that (47.5%) in non-DM group (OR = 1.69, P < 0.001). The difference was significant in comparison between type 2 DM group and non-DM group (OR = 2.05), but not in that between type 1 DM group and non-DM group (OR = 1.23, 95% CI: 0.77-1.96, P = 0.38). CONCLUSION: Our meta-analysis suggested that there is significantly higher prevalence of H. pylori infection in DM patients as compared to non-DM individuals. And the difference is associated with type 2 DM but not type 1 DM.

Certain Dietary Habits Contribute to the Functional Dyspepsia in South China Rural Area.

BACKGROUND Functional dyspepsia (FD) refers to a group of upper gastrointestinal syndromes, subdivided into two types: postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS). The etiology of FD remains unclear; however, unhealthy dietary habit is one potential underlying cause. We aim to explore the association of poor dietary habits with FD and its subtypes. MATERIAL AND METHODS A validated epidemiological questionnaire was designed to investigate dietary habits and gastrointestinal syndromes. Citizens in the Baotun community of Dongguan were invited to complete the study questionnaire. All participants were asked to undergo a physical examination and a blinded physician interview. The study was conducted from June 2015 to June 2016. FD was diagnosed using ROME III criteria. The association between investigated dietary habits and dyspeptic symptoms were explored. RESULTS There were 1,304 adult residents recruited for the study survey; 165 residents had existing organic dyspepsia (OD), 203 residents were diagnosed with FD, and the other 936 participants, who were without dyspeptic symptoms or functional gastrointestinal diseases, were regarded as the control group. Subtype diagnosis indicated 61 participants had EPS, 66 participants had PDS, and 76 participants had coexisting EPS and PDS. Unhealthy dietary habits were more prevalent in the FD group than in the control groups (75.86% versus 37.50%; p<0.001). FD was found to be associated with irregular mealtime, dining out, fatty food, sweet food, and coffee (p<0.05). The impact of each dietary factor varied with FD subtypes. CONCLUSIONS Certain types of dietary habits were positively correlated with the prevalence of FD. FD subtypes showed relatively different associations with dietary factors.

Sox9 transcriptionally regulates Wnt signaling in intestinal epithelial stem cells in hypomethylated crypts in the diabetic state.

BACKGROUND: Distinctive structures called crypts harbor intestinal epithelial stem cells (IESCs) which generate progenitor and terminally differentiated cells in the intestinal epithelium. Mammalian IESCs and their daughter cells require the participation of DNA methylation and the transcription factor Sox9 for proliferation and differentiation. However, the association between Sox9 and DNA methylation in this process remains elusive. METHODS: The DNA methylation of small intestinal epithelial crypts in db/db mice was detected via combining methylated DNA immunoprecipitation with microarray hybridization. DNA methylation of Sox9 promoter in crypts and IESCs was validated using bisulfite sequence analysis. The target sequence of the transcription factor Sox9 in IESCs was investigated via chromatin immunoprecipitation (ChIP) combined with deep sequencing (ChIP-seq). RESULTS: Increased Sox9 expression is accompanied by the loss of methylation in its promoter in IESCs. Sox9 targets the enhancers of the Wnt signaling pathway-related genes. Sox9 predominantly acts as a transcriptional activator at proximal enhancers of Wnt4, Tab2, Sox4, and Fzd8, but also functions as a potential transcriptional inhibitor at a distant enhancer of Cdk1. Lack of Sox9 transcriptional activation in specific repressors of the Wnt signaling pathway leads to the loss of intrinsic inhibitory action and ultimately produces overactivation of this pathway in db/db mice. CONCLUSIONS: Our study sheds light on the connections among DNA methylation, transcription factor modulation, and Wnt signaling in IESCs in the diabetic state. Hypomethylation in the Sox9 promoter is correlated to increased Sox9 expression in db/db IESCs. Although there is increased expression of Sox9 in db/db IESCs, the loss of Sox9 transcriptional activation in specific repressors of the Wnt signaling pathway might result in abnormalities in this pathway.

Metformin depresses overactivated Notch1/Hes1 signaling in colorectal cancer patients with type 2 diabetes mellitus.

The function of metformin in colorectal cancer (CRC) patients with diabetes mellitus (DM) remains a controversial topic because studies are increasingly focusing on epidemiologic features. We examined Notch1/Hes1 signaling in CRC with DM (DM-CRC) and investigated alterations in signaling caused by metformin treatment. For this purpose, information on pathological characteristics was collected from each patient. The proliferation of epithelium labeled with proliferating cell nuclear antigen and the differentiation of goblet cells were investigated using immunohistochemistry and periodic acid-Schiff staining, respectively. The factors involved in Notch1/Hes1 signaling were detected using qRT-PCR and western blot. In our study, we found that lymphatic metastasis, pTNM staging, and the carcinoembryonic antigen level were significantly different between groups. The depth of crypts and the rate of proliferating cell nuclear antigen-positive cells were distinctly higher in DM-CRC and patients who were managed with insulin. Moreover, the goblet cell differentiation rate was decreased in DM-CRC. The expression of Dll1, Notch1, Math1, and RBP-Jκ was increased in DM-CRC, whereas the expression of Dll4 and Hes1 was decreased in this group in normal tissue. In CRC tissue, the expression of Dll1 and Notch1 was clearly higher than that in DM-CRC. Furthermore, the trend in these changes was aggravated with insulin management and alleviated with metformin treatment. In conclusion, the abnormal cell proliferation and differentiation observed in DM-CRC are correlated with overactivated Notch1/Hes1 signaling, which is potentially relieved by metformin treatment.

Association of Bactericidal Dysfunction of Paneth Cells in Streptozocin-Induced Diabetic Mice with Insulin Deficiency.

BACKGROUND Type 1 diabetes mellitus (T1DM) is associated with increased risks of enteric infection. Paneth cells constitute the first line of the gut defense. Little is known about the impact of T1DM on the bactericidal function of intestinal Paneth cells. MATERIAL AND METHODS A T1DM mouse model was induced by intraperitoneal injection of streptozocin. The analysis of intestinal microbiota and the mucosal bactericidal assay were conducted to evaluate intestinal innate defense. Numbers of Paneth cells and their expression of related antimicrobial peptides were analyzed. Expression of total insulin receptor (IR) mRNA and relative levels of IR-A/IR-B were analyzed. The primary mouse small intestinal crypt culture was used to analyze the effect of insulin and glucose on the expression of related antimicrobial peptides of Paneth cells. RESULTS In T1DM mice, bacterial loads were increased and there was an alteration in the composition of the intestinal microflora. Exogenous bacteria had better survival in the small bowel of the T1DM mice. The expression of Paneth cell-derived antimicrobial peptides was significantly decreased in the T1DM mice, although the number of Paneth cells was increased. Relative levels of IR-A/IR-B in Paneth cells of diabetic mice were elevated, but the total IR mRNA did not change. Insulin treatment restored the expression of antimicrobial peptides and normalized the microbiota in the gut of T1DM mice. Subsequently, in vitro culture assay demonstrated that insulin rather than glucose was essential for the optimal expression of Paneth cell-derived antimicrobial peptides. CONCLUSIONS The bactericidal function of intestinal Paneth cells was impaired in STZ-induced diabetic mice, resulting in the altered intestinal flora, and insulin was essential for the optimal expression of Paneth cell-derived antimicrobial peptides.

Overexpression of miR-429 impairs intestinal barrier function in diabetic mice by down-regulating occludin expression.

Diabetes mellitus (DM) is a group of metabolic diseases characterised by insulin deficiency/resistance and hyperglycaemia. We previously reported the presence of an impaired tight junction and decreased expression of occludin (Ocln) and zonula occludens-1 (ZO-1) in the intestinal epithelial cells (IECs) of type 1 DM mice, but the exact mechanism remains unclear. In this study, we investigated the role of microRNAs (miRNAs) in impairing the tight junction in IECs of DM mice. Using an integrated comparative miRNA microarray, miR-429 was found to be up-regulated in IECs of type 1 DM mice. Then, miR-429 was confirmed to directly target the 3'-UTR of Ocln, although it did not target ZO-1. Moreover, miR-429 down-regulated the Ocln expression in IEC-6 cells in vitro. Finally, exogenous agomiRNA-429 was shown to down-regulate Ocln and induce intestinal barrier dysfunction in normal mice, while exogenous antagomiRNA-429 up-regulated Ocln in vivo and improved intestinal barrier function in DM mice. In conclusion, increased miR-429 could down-regulate the expression of Ocln by targeting the Ocln 3'-UTR, which impaired intestinal barrier function in DM mice.

miRNA-30e regulates abnormal differentiation of small intestinal epithelial cells in diabetic mice by downregulating Dll4 expression.

OBJECTIVES: Depression of the Notch/Hes1 pathway has been reported to play a role in abnormal differentiation of intestinal epithelial cells (IECs) in diabetes mellitus (DM). However, the mechanism by which this pathway influences IEC differentiation has remained unclear. In this study, we have investigated the role of microRNAs (miRNAs) in regulating the Notch/Hes1 pathway in IECs of DM mice. MATERIALS AND METHODS: Integrated comparative miRNA microarray technology was used to determine the expression profile of miRNAs in IECs of DM mice. After bioinformatic analysis, an miRNA with altered expression levels, miRNA-30e, was identified as a candidate for regulating the Notch pathway in DM. A luciferase reporter assay confirmed that miRNA-30e targeted 3'-UTR of the Notch gene. The role of miRNA-30e in regulating Notch signalling was then explored by up- and downregulating its expression in vitro and in vivo. RESULTS: Abnormal differentiation of IECs in DM mice was associated with reduced activity of the Dll4/NICD/Hes1 signal pathway. Based on bioinformatic analyses, increased expression of miRNA-30e was identified as a potential candidate for regulating Notch signalling. miRNA-30e targeted the 3'-UTR of Dll4 and downregulated Dll4 expression in primary IECs and IEC-6 cells. Exogenous miRNA-30e reduced activity of the Dll4/NICD/Hes1 pathway, and induced abnormal differentiation of IECs in normal mice. Conversely, treatment with miRNA-30e antagonist upregu-lated activity of the Dll4/NICD/Hes1 pathway in vivo, and normalized IEC differentiation in DM mice. CONCLUSIONS: Increased levels of miRNA-30e downregulated activity of the Dll4/NICD/Hes1 signalling pathway by targeting the 3'-UTR of Dll4, which contributed to abnormal differentiation in small intestinal epithelia of DM mice.

MEK/ERK pathway activation by insulin receptor isoform alteration is associated with the abnormal proliferation and differentiation of intestinal epithelial cells in diabetic mice.

In previous studies, we have reported the abnormal proliferation and differentiation of intestinal epithelial cells (IECs) in diabetes mellitus (DM) mice. The insulin receptor (IR) and its downstream mitogen-activated protein kinase kinase (MAPKK also known as MEK)/extracellular-regulated protein kinase (ERK) pathway is a classic pathway associated with cell proliferation and differentiation. The purpose of the present study is to investigate the role of the MEK/ERK pathway in abnormal proliferation and differentiation of IECs in DM mice. DM mouse models were induced by intraperitoneal injection of streptozotocin. The expression levels of the IR and its isoforms in IECs of DM mice and in IEC-6 cells were investigated. To ensure that the downstream pathways were monitored, QPCR and Western blotting were performed to detect the expression levels of MEK1/2, ERK1/2, PI3K, and Akt. Moreover, siRNA for IR-A and U0126, a specific inhibitor of MEK, were used to further investigate the relationship between the IR/MEK/ERK pathway and abnormal proliferation and differentiation of IECs in DM mice. In DM mice, excessive proliferation, disturbed differentiation, and a high ratio of IR-A/IR-B were detected in IECs. The expression levels of MEK1, MEK2, and ERK1/2 and their phosphorylated proteins in DM mice were significantly higher than those in the control group (P < 0.05), which could be offset by using siRNA for IR-A. The abnormal proliferation and differentiation of IECs in DM mice were normalized after the in vivo administration of U0126. The abnormal proliferation and differentiation of IECs in DM mice are associated with high IR-A/IR-B ratio and increased IR/MEK/ERK pathway activity.

Knockdown of linc-POU3F3 suppresses the proliferation, apoptosis, and migration resistance of colorectal cancer.

Long intergenic noncoding RNAs (lincRNAs) play important roles in regulating the biological functions and underlying molecular mechanisms of colorectal cancer (CRC). Here, we investigated the association of linc-POU3F3 and prognosis in CRC. We demonstrated that linc-POU3F3 was overexpressed in CRC tissues and positively correlated with tumor grade and N stage. Inhibition of linc-POU3F3 resulted in inhibition of cell proliferation and G1 cell cycle arrest, which was mediated by cyclin D1, CDK4, p18, Rb, and phosphorylated Rb. Inhibition of linc-POU3F3 induced apoptosis, and suppressed migration and invasion in LOVO and SW480 cell lines. This inhibition also increased the expressions of epithelial markers and decreased the expressions of mesenchymal markers, thus inhibiting the cancer epithelial-mesenchymal transition. The decreased migration and invasion following linc-POU3F3 knockdown were mediated by an increased BMP signal. Furthermore, autophagy was enhanced by linc-POU3F3 knockdown, suggesting the involvement of autophagy in the induced apoptosis. Collectively, linc-POU3F3 might be crucial in pro-proliferation, anti-apoptosis, and metastasis in LOVO and SW480 cells by regulating the cell cycle, intrinsic apoptosis, BMP signaling and autophagy. Thus, linc-POU3F3 is a potential therapeutic target and novel molecular biomarker for CRC.

DNA Methylation Dynamics During Differentiation, Proliferation, and Tumorigenesis in the Intestinal Tract.

DNA methylation, an epigenetic control mechanism in mammals, is widely present in the intestinal tract during the differentiation and proliferation of epithelial cells. Cells in stem cell pools or villi have different patterns of DNA methylation. The process of DNA methylation is dynamic and occurs at many relevant regulatory elements during the rapid transition of stem cells into fully mature, differentiated epithelial cells. Changes in DNA methylation patterns most often take place in enhancer and promoter regions and are associated with transcription factor binding. During differentiation, enhancer regions associated with genes important to enterocyte differentiation are demethylated, activating gene expression. Abnormal patterns of DNA methylation during differentiation and proliferation in the intestinal tract can lead to the formation of aberrant crypt foci and destroy the barrier and absorptive functions of the intestinal epithelium. Accumulation of these epigenetic changes may even result in tumorigenesis. In the current review, we discuss recent findings on the association between DNA methylation and cell differentiation and proliferation in the small intestine and highlight the possible links between dysregulation of this process and tumorigenesis.

Relative risk factors associated with the development of fundic gland polyps.

OBJECTIVES: The prevalence of fundic gland polyps (FGPs) is increasing. Some researchers consider this increase to be associated strongly with the long-term use of proton-pump inhibitors (PPIs); however, not all researchers share this belief. There are minimal data on the development of FGPs in China. Therefore, we aimed to investigate the prevalence of FGPs and risk factors associated with the development of this disease. MATERIALS AND METHODS: We studied 10 904 consecutive patients who underwent gastroduodenal endoscopies at our digestive endoscopy center between February 2011 and January 2013. Information on sex, age, Helicobacter pylori infection, PPIs intake, and the pathological results of the polyps were collected in the FGPs group and in the control group. The use of PPIs, sex, and H. pylori infection were statistically evaluated as dichotomous variables using a χ-test; age was evaluated as a continuous variable using a t-test. Finally, these factors were evaluated using a multiple logistic regression analysis. RESULTS: Gastric polyps were found in 759 (7.0%) patients, and 213 (2.0%) of these patients had FGPs. FGPs accounted for 28.1% of the gastric polyps. In the FGPs group, the percentage of H. pylori infection was 66.8% and the percentage of PPIs intake for at least 12 months was 23.1%. In the control group, the percentage of H. pylori infection was 77.4% and the percentage of PPIs intake for at least 12 months was 2.3%. The difference in the long-term use of PPIs was statistically significant between these two groups [χ=33.98, P<0.05, odds ratio (OR)=12.83, 95% confidence interval (CI): 4.47-36.80]. The results of the logistic regression were as follows: long-term use of PPIs (P<0.01, OR=14.11, 95% CI: 4.15-47.93); age (P<0.01, OR=1.69, 95% CI: 1.31-2.18). The P-values for sex and H. pylori infection were higher than 0.05. CONCLUSION: Age and the long-term use of PPIs were risk factors for the presence of FGPs; the long-term use of PPIs was a particularly strong risk factor.