Diabetic gastroparesis

Alpinia officinarum Hance extract ameliorates diabetic gastroparesis by regulating SCF/c-kit signaling pathway and rebalancing gut microbiota

Diabetic gastroparesis (DGP) is a common complication of type 2 diabetes mellitus (T2DM). Alpinia officinarum Hance (AOH) is one of the most commonly used both as a food and folk medicines, which is rich in diarylheptanoids and flavonoids. The gastroprotection and hypoglycemic effect make AOH has great potential in developing of anti-DGP complementary medicine. However, the molecular mechanisms of AOH that act against DGP are yet to be elucidated. In this study, we evaluated the therapeutic effects, the potential molecular mechanism, and the changes of gut microbiota of AOH in DGP. The 5 components of the AOH were analyzed, and the potential signaling pathway of AOH improving DGP was predicted by molecular docking. Subsequently, DGP rat model was constructed using high-fat-irregular-diet, AOH intervention significantly reduced blood glucose levels, increased gastrointestinal propulsion rate, and improved gastric histological morphology in DGP rats. Meanwhile, AOH has been shown to regulate the SCF/c-kit signaling pathway and rebalance the gut microbiota, which may be closely related to its role in improving DGP. Taken together, AOH may play a protective role on DGP through multiple mechanisms, which might pave the road for development and utilization of AOH.

Low-intensity pulsed ultrasound at ST36 improves the gastric motility by TNF-α/IKKβ/NF-κB signaling pathway in diabetic rats

BACKGROUND AND AIM

Low-intensity pulsed ultrasound (LIPUS) can effectively regulate the central and peripheral nervous system. However, whether LIPUS could act on acupuncture points to modulate the activity of peripheral nervous has rarely been studied. Our study aimed to investigate whether LIPUS at ST36 could improve gastric emptying in diabetic gastroparesis rats.

METHODS

Sprague-Dawley male rats were divided into three groups: control group (CON), diabetic gastroparesis group (DM), and diabetic gastroparesis LIPUS treated group (LIPUS). The body weight and blood glucose were recorded every week. Glucose tolerance, gastric emptying rate, and gastric motility were measured before and after treatment. Gastric motility was assessed by ultrasonic examination and Muscle strip experiment. The expression level of c-Kit was assessed by immunohistochemistry staining. Levels of TNF-α, p-NF-κB p-65, NF-κB p-65, and p-IKKβ, IKKβ were measured by western blot.

RESULTS

We reported LIPUS at an intensity of 0.88 W/cm2 exhibited significant differences in functional recovery of gastric delayed emptying in diabetic rats. Through ultrasound gastric motility functional testing and analysis of gastric antral smooth muscle strips indirectly and directly proved the effectiveness of LIPUS for the recovery of gastric delayed emptying. Pathological analysis and western blot indicated that the mechanism by which LIPUS applied to ST36 improved gastric motility may be partially attributed to the inhibition of the TNF-α/IKKβ/NF-κB signaling pathway, thereby rescuing the damaged interstitial cells of Cajal network.

CONCLUSION

LIPUS at ST36 improved the gastric motility and rescued the damaged networks of interstitial cells of Cajal. LIPUS may have a promising therapeutic potential for diabetic gastroparesis.

T2DB: A Web Database for Long Non-Coding RNA Genes in Type II Diabetes

Type II diabetes (T2D) is a growing health problem worldwide due to increased levels of obesity and can lead to other life-threatening diseases, such as cardiovascular and kidney diseases. As the number of individuals diagnosed with T2D rises, there is an urgent need to understand the pathogenesis of the disease in order to prevent further harm to the body caused by elevated blood glucose levels. Recent advances in long non-coding RNA (lncRNA) research may provide insights into the pathogenesis of T2D. Although lncRNAs can be readily detected in RNA sequencing (RNA-seq) data, most published datasets of T2D patients compared to healthy donors focus only on protein-coding genes, leaving lncRNAs to be undiscovered and understudied. To address this knowledge gap, we performed a secondary analysis of published RNA-seq data of T2D patients and of patients with related health complications to systematically analyze the expression changes of lncRNA genes in relation to the protein-coding genes. Since immune cells play important roles in T2D, we conducted loss-of-function experiments to provide functional data on the T2D-related lncRNA USP30-AS1, using an in vitro model of pro-inflammatory macrophage activation. To facilitate lncRNA research in T2D, we developed a web application, T2DB, to provide a one-stop-shop for expression profiling of protein-coding and lncRNA genes in T2D patients compared to healthy donors or subjects without T2D.

[Diabetic gastroenteropathy: modern methods of diagnosis and treatment]

Diabetes mellitus is a chronic disease with a growing prevalence worldwide, however, the prevalence of its complications, including gastroenteropathy, is also increasing. The pathophysiology of diabetic gastroenteropathy (DH) combines hyperglycemia, vagus nerve dysfunction, decreased expression of nitric oxide synthase in the myenteric plexus, changes in the interstitial Cajal cell network, as well as oxidative stress. Clinical signs of DH are gastroesophageal reflux, gastroparesis, constipation, abdominal pain and diarrhea. Among the diagnostic methods are manometry with pH measurement (assessment of esophageal motility), gastric emptying scintigraphy, respiratory test (to assess gastroparesis), aspiration and cultivation of the contents of the jejunum (to diagnose bacterial overgrowth syndrome). To date, there is no definitive treatment for DH - an interdisciplinary approach is aimed at slowing the progression of the disease, relieving symptoms and restoring gastrointestinal function. Patients are recommended a diet low in simple sugars and high in fiber; optimization of glycemic control with a target glycemia of less than 180 mg/dl. As for drug therapy, the use of prokinetics and antiemetics is justified, and in case of excessive bacterial growth syndrome, antibacterial therapy (rifaximin) is carried out. Modern approaches to the treatment of DH are also accumulating, including the use of botulinum toxin, pyloroplasty and electrical stimulation of the stomach in individual patients. Despite the constant development of new treatments, they are not yet able to completely cure DH in the near future, which makes it necessary to conduct further research in this area.

Helpful or harmful? The impact of the ketogenic diet on eating disorder outcomes in type 1 diabetes mellitus

INTRODUCTION

Eating disorders (EDs) are common complications in people with type 1 diabetes (PwT1D), given the rigid focus on food and insulin dose adjustment. Dietary recommendations for T1D match those for the general population, yet many fail to achieve target HbA1c. Evidence suggests that lower carbohydrate meals and thus reduced insulin requirements may decrease inconsistencies in insulin absorption, maintain euglycemia and weight. Dietary restriction is a recognized risk factor for ED development, and Ketogenic Diets (KD) involve restriction of common family-based foods, thus impacting social normality and microbiome diversity. We reviewed the current literature on PwT1D following a KD to understand effects on ED risks.

AREAS COVERED

Published data from MEDLINE, Embase, and PsycINFO were used. Search terms included: type 1 diabetes mellitus; or insulin dependent diabetes or T1D AND EDs or anorexia or bulimia or disordered eating AND low-carbohydrate diet or carbohydrate restricted diet or low carb diet or ketogenic diet.

EXPERT OPINION

Research into the effects of KDs on ED outcomes in PwT1D are limited, given the concerns over risks of diabetic ketoacidosis, hypoglycemia, and dyslipidemia. Longer term studies on the participants' experience and motivations of adhering or admonishing the diet are needed.

Neural control of pancreatic peptide hormone secretion

Pancreatic peptide hormone secretion is inextricably linked to maintenance of normal levels of blood glucose. In animals and man, pancreatic peptide hormone secretion is controlled, at least in part, by input from parasympathetic (vagal) premotor neurons that are found principally in the dorsal motor nucleus of the vagus (DMV). Iatrogenic (insulin-induced) hypoglycaemia evokes a homeostatic response commonly referred to as the glucose counter-regulatory response. This homeostatic response is of particular importance in Type 1 diabetes in which episodes of hypoglycaemia are common, debilitating and lead to suboptimal control of blood glucose. Glucagon is the principal counterregulatory hormone but for reasons unknown, its secretion during insulin-induced hypoglycaemia is impaired. Pancreatic parasympathetic neurons are distinguishable electrophysiologically from those that control other (e.g. gastric) functions and are controlled by supramedullary inputs from hypothalamic structures such as the perifornical region. During hypoglycaemia, glucose-sensitive, GABAergic neurons in the ventromedial hypothalamus are inhibited leading to disinhibition of perifornical orexin neurons with projections to the DMV which, in turn, leads to increased secretion of glucagon.

Relationship Between Gastric Emptying Rate and Simultaneously Assessed Symptoms in Functional Dyspepsia

METHODS

During a GE test (breath test with ¹³C-octanoic acid labelled 250 kcal solid meal), the severity of 6 symptoms (postprandial fullness, epigastric pain and burning, bloating, nausea and belching) was assessed, every 15 min, before meal-intake and 4h postprandially. The sum of individual symptom scores generated the meal-related symptoms score; the sum of all symptoms generated overall meal-related symptom severity (OSS). Data were compared in patients with normal and delayed GE (cut-off T_1/2≥ 109 min). Data are shown as mean±SEM.

RESULTS

504 patients were included, of which 382 patients (67% female, age 43.8±0.8 years, BMI 23.3±0.2 kg/m²) had normal and 122 patients (77% female, age 42.7±1.5 years, BMI 23.2±0.6 kg/m²) had delayed GE. OSS tended to be higher in patients with delayed GE (81.8±3.4 vs. 99.5±7.1, p=.05). Only nausea was significantly higher in patients with delayed GE (11±0.8 vs. 16±1.6, p=.01). No correlations were observed between GE rate and any of the symptoms (OSS: r=0.06, p=.2; nausea: r=0.06, p=.1). The symptom severity time course showed a significant difference only for nausea, with increased severity ratings 90 min after the meal (p<.01) in delayed GE compared to normal GE patients.

CONCLUSION

The severity of symptoms in functional dyspepsia and idiopathic gastroparesis, even when assessed during the GE test meal, is not correlated to gastric emptying rate. (Ethics committee University Hospital of Leuven study number S55426).

CNS-Sparing Histamine H3 Receptor Antagonist as a Candidate to Prevent the Diabetes-Associated Gastrointestinal Symptoms

Among the histamine receptors, growing evidence points to the histamine H₃ receptor as a pharmacological candidate to counteract the autonomic neuropathy associated with diabetes. The study aimed to evaluate the effect of PF00868087 (also known as ZPL-868), a CNS-sparing histamine H₃ receptor antagonist, on the autonomic neuropathy of the intestinal tract associated with diabetes. Diabetes was induced in male BALB/c mice by a single high dose of streptozotocin (150 mg/kg). Colorectal specimens from control and diabetic mice, randomized to vehicle or PF0086087 (10, 30, 100 mg/kg/day by oral gavage for 14 days), were processed for morphological and immunohistochemical analysis. A significant overproduction of mucus in the intestinal mucosa of diabetic mice compared to the controls was observed. PF0086087 at the highest dose prevented mucin overproduction. The immunohistochemistry analysis demonstrated that diabetes causes a decrease in the inhibitory component of enteric motility, measured as the percentage of neuronal nitric oxide synthase-positive neurons (p < 0.05) and a parallel increase in the excitatory component evaluated as substance P-positive fibres (p < 0.01). PF0086087 dose-dependently prevented these pathophysiological events. In conclusion, PF0086087 may be an essential tool in preventing nitrergic dysfunction in the myenteric plexus of the distal colon and diabetes-induced gastrointestinal complications.

Gastroparesis: A Multidisciplinary Approach to Management

Gastroparesis is a neuromuscular disorder whose hallmark is delayed gastric emptying. It is a global challenge to the healthcare system because of poor treatment satisfaction for both the patients and clinicians, eventually leading to a reduction in the quality of life, with antecedent anxiety and depression. Although it is multifactorial in origin, diabetic, idiopathic, and drug-induced gastroparesis are the major risk factors. Disrupted interstitial cells of Cajal (ICC) and gastric dysrhythmia are pivotal to the pathogenesis, with most of the investigations targeted toward assessing gastric emptying and accommodation usually affected by distorted ICC and other neural networks. The treatment challenges can be overcome by a multidisciplinary approach involving gastroenterologists, gastrointestinal surgeons, biomedical engineers, nutritionists, psychologists, nurses, radionuclide radiologists, pharmacists, and family physicians. The exploration of the fundamental physiological processes underlying gastroparesis with the use of biomechanical materials should be given more attention by biomedical engineers to integrate innovative engineering with medicine for solving complex medical issues.

MALAT1: A Pivotal lncRNA in the Phenotypic Switch of Gastric Smooth Muscle Cells via the Targeting of the miR-449a/DLL1 Axis in Diabetic Gastroparesis

Diabetic gastroparesis (DGP) is a common complication of diabetes mellitus (DM). Our previous study suggested that the expression of the long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is closely related to DGP. However, the role of MALAT1 in DGP pathogenesis remains unclear. Here, we aim to characterize the role of MALAT1 in DGP. First, we analyzed the lncRNA expression profiles through lncRNA sequencing. Next, we detected MALAT1 expression in the stomach tissues of DGP model mice and diabetic patients. Then, we investigated the role and mechanisms of MALAT1 in the proliferation, migration, phenotypic switch, and carbachol-induced intracellular Ca²⁺ changes in human gastric smooth muscle cells (HGSMCs) under high glucose (HG) conditions, using short hairpin RNA technology, RNA immunoprecipitation, and dual-luciferase reporter assays. We show that MALAT1 expression was upregulated in the gastric tissues of DGP model mice, the adjacent healthy tissues collected from diabetic gastric cancer patients with DGP symptoms, and in HGSMCs cultured under HG conditions. Functionally, MALAT1 knockdown in vitro impacted the viability, proliferation, migration and promoted the phenotypic switch of HGSMCs under HG conditions. Additionally, we show that MALAT1 sponged miR-449a, regulating Delta-like ligand 1 (DLL1) expression in HGSMCs; any disturbance of the MALAT1/miR-449a/DLL1 pathway affects the proliferation, migration, phenotypic switch, and carbachol-induced Ca²⁺ transient signals in HGSMCs under HG conditions. Collectively, our data highlight a novel regulatory signaling pathway, the MALAT1/miR-449a/DLL1 axis, in the context of DGP.

Electroacupuncture at ST36 Improve the Gastric Motility by Affecting Neurotransmitters in the Enteric Nervous System in Type 2 Diabetic Rats

Electroacupuncture (EA) can effectively relieve hyperglycemia and gastric emptying disorders in diabetic gastroparesis (DGP). However, the effect of EA on type 2 diabetes mellitus (T2DM) gastroparesis and its mechanism in the enteric nervous system (ENS) are rarely studied. We investigated the therapeutic effect of EA at ST36 and its effect on the main inhibitory and excitatory neurotransmitters in the ENS in DGP rats. Male Sprague-Dawley (SD) rats were fed a high-fat diet for 2 weeks and injected with streptozotocin (STZ) at 35 mg/kg to induce T2DM. T2DM rats were divided into the diabetic mellitus (DM) group and the EA group. The control (CON) group comprised normal rats without any intervention. EA treatment was started 6 weeks after the induction of DM and continued for 5 weeks. The body weight and food intake of the rats were recorded every week. Blood glucose, insulin, glucose tolerance, gastric emptying, and antral motility were measured after treatment. The expression of protein gene product 9.5 (PGP9.5), neuronal nitric oxide synthase (nNOS), and choline acetyltransferase (ChAT) in gastric antrum were quantified by western blotting and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The T2DM gastroparesis model was successfully established. EA treatment reduced the body weight, food intake, and blood glucose; improved glucose intolerance and insulin resistance; increased the gastric emptying rate, the mean antral pressure, and the amplitude of antral motility; and decreased the frequency of antral motility compared with those in the DM group. EA treatment increased the expression level of nNOS, ChAT, and PGP9.5 proteins, and nNOS and ChAT mRNA. The results suggested that EA at ST36 could ameliorate DGP, partly restore the damage to general neurons, and increase nNOS and ChAT in the gastric antrum. EA improved DGP partly via reducing the loss of inhibitory and excitatory neurotransmitters in the ENS.

Diabetic gastroenteropathy: An underdiagnosed complication

This article is an extensive review that provides an update on the pathophysiology, symptoms, diagnosis, and treatment of diabetic gastroenteropathy. There is no reported prevalence, but it has been described that patients with type 1 diabetes have a cumulative incidence at 10 years of 5.2%, and type 2 patients, 1%. Also, in the group of type 1 diabetes, it has been observed that women are more likely to present this condition (5.8% vs 3.5%). Many factors are associate with its development (e.g., hyperglycemia, vagal dysfunction, loss of expression of neural nitric oxide synthase in the myenteric plexus, alterations in the Cajal interstitial cell network, and oxidative stress). Gastrointestinal discomfort could be perceived 70% higher in diabetic patients, describing that 25% of diabetic patients experience gastrointestinal symptoms. Diabetic enteropathy could affect any portion of the gastrointestinal tract, but esophageal alterations were described in more than 60% of diabetic patients, also 60% of them present constipation, and 20%, diarrhea. Gastric emptying scintigraphy is useful to evaluate gastroparesis, therefore, gastric retention of more than 60% at 2 h has a sensitivity of 100% and specificity of 20% for diagnosis; however, other studies such as breath tests, with a sensitivity of 89% and a specificity of 80%, or the endoscopic capsule contribute to the diagnosis. There is no cure; however, management must be multidisciplinary, focused on slowing the progression of diabetic gastroenteropathy, reducing symptoms, and restoring function; that includes nutritional recommendation, maintain glucose levels kept below 180 mg/dL, use of prokinetics, anti-emetics; nowadays, it has been special interest in surgical treatment, such as pyloroplasty, also gastric electrical stimulation appears to be another alternative.

Prucalopride in diabetic and connective tissue disease-related gastroparesis: Randomized placebo-controlled crossover pilot trial

BACKGROUND

Gastroparesis, defined by delayed gastric emptying in the absence of mechanical outlet obstruction, is a frequent neuropathic complication of diabetes mellitus, and effective treatments are lacking. Prucalopride is a pan-gut prokinetic with selective agonist effects on serotonin 5-HT4 receptors in the gut. This study aimed to assess the effect of prucalopride 4 mg daily on Gastroparesis Cardinal Symptom Index (GCSI), meal-related symptom score (MRSS), and gastric emptying rate in diabetic or connective tissue disease (CTD)-related gastroparesis patients.

METHODS

This was a double-blind crossover trial of four-week treatment periods with prucalopride or placebo divided by two weeks of washout. GSCI, MRSS, gastric emptying scintigraphy, PAGI-SYM, and PAGI-QoL were assessed at baseline and the end of each treatment period. Daily bowel movement (BM) frequency and gastrointestinal symptoms were recorded in each period.

KEY RESULTS

Fifteen gastroparesis patients (13 diabetic, 2 CTD) were enrolled. GCSI scores were lower than baseline but not different between treatment arms. MRSS scores over time or cumulative score were not significantly different between groups. Gastric emptying was more rapid in the prucalopride treatment period, with mean four-hour meal retention of 22 ± 6% in PRU period vs 40 ± 9% in the placebo period (P = 0.05). Weekly BM frequency was significantly higher in prucalopride than placebo periods (10.5 ± 1.8 vs 7.5 ± 0.8, P < 0.0001). Perception of weight loss was higher in patients on prucalopride. Analysis of diabetic gastroparesis (n = 13) population did not change the conclusions.

CONCLUSION AND INFERENCE

Prucalopride at 4 mg accelerates gastric emptying and bowel movement frequency but does not appear to ameliorate gastroparesis or meal-related symptoms in this study.

Disturbed Gastrointestinal Contractility in a Polycystic Ovary Syndrome Rat Model

BACKGROUND

Polycystic ovary syndrome (PCOS), a common hormonal disorder in women, affects 4-18% of women of reproductive age worldwide. A higher prevalence of irritable bowel syndrome was found in women with PCOS. However, the effects and mechanism of PCOS on stomach and colon contractility remain unclear.

AIMS

This study aims to evaluate the correlation between PCOS and gastrointestinal disorder.

METHODS

Four-week-old female rats were subcutaneously implanted with pellets containing 7.5 mg of dihydrotestosterone for 13 weeks to create PCOS rat models. After vaginal smears, the estrus cycle stage was evaluated. Oral glucose tolerance test was performed after 90 days of treatment. All animals were killed at 17 weeks. The rats were fasted overnight and then anesthetized before decapitation, and the stomach fundus and colon were surgically removed and cultured in oxygenated Krebs solution. Acetylcholine and carbachol were used to evaluate the cholinergic system on contractility.

RESULTS

The basal and stomach fundus responded with a reduced frequency and contractility in response to acetylcholine in the PCOS group. Moreover, no difference was found in the spontaneous stomach contractility induced by carbachol in both groups. Lower maximal colon muscle contractility was also found in response to acetylcholine stimulation in PCOS rats. Furthermore, lower maximal muscle contractility was found in response to extracellular calcium levels. MLC20 phosphorylation was also reduced in the gastrointestinal tissue in PCOS rats.

CONCLUSIONS

PCOS induces gastroparesis and reduces gastrointestinal muscle contractility. This effect is, at least partly, through reducing the responsiveness of acetylcholine and MLC20 phosphorylation.

Inhibition of GSK-3β restores delayed gastric emptying in obesity-induced diabetic female mice

Diabetic gastroparesis (DG) is a clinical syndrome characterized by delayed gastric emptying (DGE). Loss of nuclear factor erythroid 2-related factor 2 (Nrf2) is associated with reduced neuronal nitric oxide synthase-α (nNOSα)-mediated gastric motility and DGE. Previous studies have shown that nuclear exclusion and inactivation of Nrf2 is partly regulated by glycogen synthase kinase 3β (GSK-3β). In the current study, the molecular signaling of GSK-3β-mediated Nrf2 activation and its mechanistic role on DG were investigated in high-fat diet (HFD)-induced obese/Type 2 diabetes (T2D) female mice. Adult female C57BL/6J mice were fed with HFD or normal diet (ND) with or without GSK-3β inhibitor (SB 216763, 10 mg/kg body wt ip) start from the 14th wk and continued feeding mice for an additional 3-wk time period. Our results show that treatment with GSK-3β inhibitor SB attenuated DGE in obese/T2D mice. Treatment with SB restored impaired gastric 1) Nrf2 and phase II antioxidant enzymes through PI3K/ERK/AKT-mediated pathway, 2) tetrahydrobiopterin (BH₄, cofactor of nNOS) biosynthesis enzyme dihydrofolate reductase, and 3) nNOSα dimerization in obese/T2 diabetic female mice. SB treatment normalized caspase 3 activity and downstream GSK-3β signaling in the gastric tissues of the obese/T2 diabetic female mice. In addition, GSK-3β inhibitor restored impaired nitrergic relaxation in hyperglycemic conditions. Finally, SB treatment reduced GSK3 marker, pTau in adult primary enteric neuronal cells. These findings emphasize the importance of GSK-3β on regulating gastric Nrf2 and nitrergic mediated gastric emptying in obese/diabetic rodents.NEW & NOTEWORTHY Inhibition of glycogen synthase kinase 3β (GSK-3β) with SB 216763 attenuates delayed gastric emptying through gastric nuclear factor erythroid 2-related factor 2 (Nrf2)-phase II enzymes in high-fat diet-fed female mice. SB 216763 restored impaired gastric PI3K/AKT/ β-catenin/caspase 3 expression. Inhibition of GSK-3β normalized gastric dihydrofolate reductase, neuronal nitric oxide synthase-α expression, dimerization and nitrergic relaxation. SB 216763 normalized both serum estrogen and nitrate levels in female obese/Type 2 diabetes mice. SB 216763 reduced downstream signaling of GSK-3β in enteric neuronal cells in vitro.

Electroacupuncture Relieves Suppression of Autophagy in Interstitial Cells of Cajal of Diabetic Gastroparesis Rats

BACKGROUND

The incidence of diabetic gastroparesis (DGP) is mainly blamed to abnormity of interstitial cells of Cajal (ICCs). Autophagy could degrade damaged proteins and organelles to keep intracellular homeostasis, and it could directly influence structure and number of cells. In this study, we aimed to figure out the relationship between DGP and autophagy of ICCs.

METHODS

Sixty Sprague-Dawley (SD) rats were randomly divided into normal control group (NC, 10) and modeling group (50). Rats in the modeling group were injected 2% streptozotocin (STZ) and fed with high-glucose and high-fat diet for 8 weeks in order to establish DGP rat model. After modeling, 30 successfully modeled rats were randomly selected and separated into diabetic gastroparesis group (DGP, 10), GDP rats with electroacupuncture group (EA, 10), and GDP rats with metoclopramide group (MP, 10). When the intervention was completed, blood glucose was measured by ONE TOUCH glucometer and gastrointestinal propulsive rate was detected through measuring optical density. Autophagosomes were observed under transmission electron microscope (TEM). The expression of LC3 protein and P62 protein was measured by Western blot. When ICCs were transfected with GFP-RFP-LC3 plasmid, autophagy flux was observed by laser scanning confocal microscope.

RESULTS

(1) After intervention, compared with blood glucose of rats in the NC group, all of the DGP, EA, and MP groups were remarkably increased (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01); compared with the DGP group, the blood glucose of the EA and MP groups was decreased greatly (P < 0.01). (2) Compared with gastrointestinal propulsive rate of rats in the NC group, no matter gastric emptying rate or intestinal propulsive rate, the EA and MP groups were significantly reduced (P < 0.01); compared with the NC group, gastric emptying rate and intestinal propulsive rate in the EA group were obviously decreased (P < 0.05, P < 0.01); compared with the DGP group, the EA and MP groups were increased significantly (P < 0.01). (3) Compared with the NC group, intensity of RFP and GFP in the DGP group was obviously increased (P < 0.05, P < 0.01), in other words, the DGP group accompanying suppression of autophagy; compared with the DGP group, intensity of RFP and GFP in the EA group was decreased significantly (P < 0.05, P < 0.01). (4) There was no autophagosome in the NC group, and an autophagosome existed in the DGP group. Both EA and MP groups found autophagy. (5) When coming to LC3 II/LC3 I, compared with the NC group, the ratio was enhanced in the DGP and EA groups (P < 0.01, P < 0.05); compared with the DGP group, LC3 II/LC3 I was dramatically decreased in the MP and EA groups (P < 0.01). (6) As the substrate of degradation, the expression of P62 in the other three groups was significantly increased (P < 0.01) compared with the NC group; compared with the DGP group, the amount of P62 in the EA and MP groups was reduced greatly (P < 0.01).

CONCLUSION

The impaired autophagy flux in ICCs is the pathological basis of diabetic gastroparesis, blaming to fusion dysfunction of autophagosome and lysosome and electroacupuncture (EA) could ease the suppression of autophagy to improve gastric motility.

Diabetic Gastroparesis: Perspectives From a Patient and Health Care Providers

Gastroparesis is defined as a delay in gastric emptying in the absence of mechanical obstruction in the stomach. Gastroparesis has a number of causes, including postsurgical, secondary to medications, postinfectious, idiopathic, and as a complication of diabetes mellitus, where it is underrecognized. The cardinal symptoms of diabetic gastroparesis are nausea, early satiety, bloating, and vomiting. Diabetic gastroparesis is more common in females and has a cumulative incidence of 5% in type 1 diabetes and 1% in type 2 diabetes. It is associated with a reduction in quality of life and exerts a significant burden on health care resources. The pathophysiology of this disorder is incompletely understood. Diagnosis is made based on typical symptoms associated with the demonstration of delayed gastric emptying in the absence of gastric outlet obstruction. Gastric emptying scintigraphy is the gold standard for demonstrating delayed gastric emptying, but other methods exist including breath testing and the wireless motility capsule. Diabetic gastroparesis should be managed within a specialist multidisciplinary team, and general aspects involve dietary manipulations/nutritional support, pharmacological therapy, and surgical/endoscopic interventions. Specific pharmacological therapies include prokinetics and antiemetics, with several new medications in the drug development pipeline. Surgical/endoscopic interventions include botulinum toxin injection into the pylorus, gastric peroral endoscopic myotomy and gastric electrical stimulation. This article provides a detailed review and summary of the epidemiology, pathophysiology, investigation, and management of diabetic gastroparesis, and also gives an individual patient's perspective of living with this disabling disorder.

Pathophysiology and management of diabetic gastroenteropathy

Polyneuropathy is a common complication to diabetes. Neuropathies within the enteric nervous system are associated with gastroenteropathy and marked symptoms that severely reduce quality of life. Symptoms are pleomorphic but include nausea, vomiting, dysphagia, dyspepsia, pain, bloating, diarrhoea, constipation and faecal incontinence. The aims of this review are fourfold. First, to provide a summary of the pathophysiology underlying diabetic gastroenteropathy. Secondly to give an overview of the diagnostic methods. Thirdly, to provide clinicians with a focussed overview of current and future methods for pharmacological and nonpharmacological treatment modalities. Pharmacological management is categorised according to symptoms arising from the upper or lower gut as well as sensory dysfunctions. Dietary management is central to improvement of symptoms and is discussed in detail, and neuromodulatory treatment modalities and other emerging management strategies for diabetic gastroenteropathy are discussed. Finally, we propose a diagnostic/investigation algorithm that can be used to support multidisciplinary management.

Gastric Electrical Stimulation Improves Symptoms of Diabetic Gastroparesis in Patients on Peritoneal Dialysis-2 Case Reports

Diabetic gastroparesis (DGP), a delay in gastric emptying without obstruction to outflow as a complication of diabetes, typically develops after at least 10 years of diabetes. Cardinal symptoms include nausea, vomiting, early satiety, bloating, and upper abdominal pain. The aim of DGP treatment is to alleviate the severity and frequency of symptoms, improve the level of gastric emptying, ameliorate the patient's nutritional status and to optimize glycemic control. In the treatment of chronic drug-refractory nausea and vomiting secondary to DGP, gastric electrical stimulation (GES) such as Enterra Therapy System (Medtronic Inc., Minneapolis, MN, USA) can be considered. It is well established that diabetic nephropathy is the most common cause of end-stage renal disease (ESRD) requiring renal replacement therapy. The exact prevalence of patients with severe DGP and ESRD is not known; however, finding a therapeutic approach to these patients, particularly those whose gastroparesis symptoms preclude them from undergoing kidney transplant procedure, represents a huge challenge. Our experience suggests that GES implantation can be an effective treatment modality for type 1 diabetic patients on peritoneal dialysis (PD) who are simultaneous pancreas-kidney transplantation candidates, by improving the severity and frequency of gastroparesis symptoms and eventually ensuring their optimal nutritional and fluid intake.

Efficacy of Gastric Electrical Stimulation for Gastroparesis: US/European Comparison

BACKGROUND

Gastric electrical stimulation (GES) is used in both the US and Europe, but little research has investigated the demographics of gastroparesis patients receiving GES by geographic location.

METHODS

We compared data from 380 patients, 296 female and 84 males, mean age 42 years, 246 idiopathic (ID), 107 diabetic (DM), and 27 post-surgical (PS). The statistical significance was calculated by Chi-square test and a P-value obtained for ID, DM, and PS. The statistical significance was calculated by Fischer exact test and a P-value obtained comparing male vs. female.

RESULTS

European centers had 61 GES patients compared to 319 from the US. In Europe, 100% of patients had gastric emptying test (GET) values available; in the US, it was 75% of patients. European centers had more DM patients (59%) than the US (22%), and a smaller proportion of ID patients (25%) than the US (72%). There was a statistical difference between the causes of gastroparesis in the patients receiving GES (P-value < 0.00001). There was also significant difference in the gender of the patients receiving GES, with a greater proportion of women in the US (P value = 0.0023).

CONCLUSIONS

Comparing GES in US vs. Europe demonstrated significant differences in gastroparesis demographics and percentage of patients with GET data. After analyzing the previously discussed results and reviewing recent updates in evidence-based medicine guidelines, the discrepancy and variance in patient populations in the US and Europe emphasizes the need for a database that allows better analysis and treatment of gastroparesis patients worldwide including stimulation therapies.

Implication of neurohormonal-coupled mechanisms of gastric emptying and pancreatic secretory function in diabetic gastroparesis

Recently, diabetic gastroparesis (DGP) has received much attention as its prevalence is increasing in a dramatic fashion and management of patients with DGP represents a challenge in the clinical practice due to the limited therapeutic options. DGP highlights an interrelationship between the gastric emptying and pancreatic secretory function that regulate a wide range of digestive and metabolic functions, respectively. It well documented that both gastric emptying and pancreatic secretion are under delicate control by multiple neurohormonal mechanisms including extrinsic parasympathetic pathways and gastrointestinal (GI) hormones. Interestingly, the latter released in response to various determinants that related to the rate and quality of gastric emptying. Others and we have provided strong evidence that the central autonomic nuclei send a dual output (excitatory and inhibitory) to the stomach and the pancreas in response to a variety of hormonal signals from the abdominal viscera. Most of these hormones released upon gastric emptying to provide feedback, and control this process and simultaneously regulate pancreatic secretion and postprandial glycemia. These findings emphasize an important link between gastric emptying and pancreatic secretion and its role in maintaining homeostatic processes within the GI tract. The present review deals with the neurohormonal-coupled mechanisms of gastric emptying and pancreatic secretory function that implicated in DGP and this provides new insights in our understanding of the pathophysiology of DGP. This also enhances the process of identifying potential therapeutic targets to treat DGP and limit the complications of current management practices.

An Exceptional Case of Diabetic Ketoacidosis

We present a case of diabetic ketoacidosis, known as one of the most serious metabolic complications of diabetes. We were confronted with rapid neurological deterioration and unseen glycaemic values, which reached almost 110 mmol/L, subsequently resulting in hyperkalaemia and life-threatening dysrhythmias. This is the first reported live case with such high values of blood glucose and a favourable outcome.

Up-regulation of the Ang II/AT1 receptor may compensate for the loss of gastric antrum ICC via the PI3k/Akt signaling pathway in STZ-induced diabetic mice

The classic renin-angiotensin system (RAS) is a complex system in which angiotensin II (Ang II) has been identified as an important endogenous regulator that influences both smooth muscle contraction and cell growth. Although a local RAS is known to exist in the gastrointestinal tract, it is unclear whether Ang II is involved in the loss of gastric interstitial cells of Cajal (ICC) in diabetic mice. The present study was designed to investigate the effect of Ang II on ICC survival in streptozotocin (STZ)-induced diabetic mice. Western blot, immunofluorescence, isometric muscle recording, enzyme-linked immunosorbent assay (ELISA) and a cell counting kit-8 were used in this research. Our results demonstrate that the c-Kit and membrane-bound stem cell factor (mSCF) protein expression levels in gastric smooth muscle were decreased in STZ-induced diabetic mice. However, the angiotensin receptor type 1 (AT1R) expression levels in gastric smooth muscle and angiotensin-converting enzyme (ACE) expression levels in gastric mucosa were increased. The effect of Ang II on the tonic contraction of gastric smooth muscle was potentiated in diabetic mice, and the plasma Ang II level was enhanced. Ang II increased mSCF expression, cell proliferation, and Akt-Ser473 phosphorylation in cultured gastric smooth muscle cells (GSMCs). These effects were reduced by specific inhibitors ZD7155 (an AT1R antagonist) and LY294002 (a PI3-kinase inhibitor). Our results suggest that Ang II increases mSCF expression and cell proliferation in cultured GSMCs in a PI3K/Akt signaling-dependent manner. ACE and AT1R up-regulation in the stomach may help compensate for ICC loss in STZ-induced diabetic mice.

Effectiveness and safety of Helicobacter pylori eradication in treating diabetic gastroparesis patients with Helicobacter pylori infection: Meta-analysis

AIM: To evaluate the effectiveness and safety of Helicobacter pylori (H. pylori) eradication in treating diabetic gastroparesis (DGP) patients with H. pylori infection.

METHODS: Online databases (PubMed, EMbase, Cochrane Library, Wangfang, CNKI and CBMdice) were searched for randomized controlled trials investigating therapeutic effects of H. pylori eradication vs conventional treatment. Outcomes were analyzed with RevMan 5.3.

RESULTS: Six randomized controlled trials containing 508 patients were included. The results of meta-analysis showed that H. pylori eradication was superior to conventional treatment for DGP patients in clinical effects (RR = 1.33, 95%CI: 1.21-1.47, P < 0.00001). The incidence of adverse events was similar between the two therapies (P = 0.39).

CONCLUSION: Compared with the conventional treatment, H. pylori eradication has more significant clinical effects and comparable incidence of adverse events.

Gastroparesis

PURPOSE OF REVIEW

This review summarizes recent progress in the epidemiology, pathophysiology, and treatment of gastroparesis.

RECENT FINDINGS

The relationship between delayed gastric emptying and symptom pattern in gastroparesis and, related to it, its separation from functional dyspepsia remains an area of controversy and uncertainty. Pathophysiological studies have focused on the role of pyloric resistance and duodenal motility in generation of symptoms. In diabetic patients, glycemic control did not determine short-term changes in gastric emptying rate in type 2 diabetes, but poor glycemic control was a major risk factor for long-term development of gastroparesis in type 1 diabetes. At the cellular level, diabetic gastroparesis is characterized by loss of interstitial cells of Cajal (ICCs), and this is inversely correlated to the number of CD206+ macrophages, which are thought to have a protective effect on ICCs. Treatment trials have focused on dietary factors and a nasal spray formulation of metoclopramide. A meta-analysis of prokinetic studies found no association between symptom improvement and enhancement of gastric emptying in gastroparesis. Two controlled studies showed no benefit of tricyclic antidepressants (nortriptyline, amitriptyline) in idiopathic gastroparesis and functional dyspepsia with delayed emptying.

SUMMARY

The relationship between delay in gastric emptying, symptom pattern, and response to prokinetic therapy in gastroparesis is poor. In diabetes, gastroparesis is characterized by loss of ICCs, and this is inversely correlated to the number of CD206+ macrophages. Dietary interventions may help to alleviate symptoms. Tricyclic antidepressants do not provide symptomatic benefit to patients with idiopathic gastroparesis.

Relationship between ghrelin and abnormal gastric emptying in diabetes mellitus

In recent years, the morbidity of diabetes mellitus has increased rapidly in the world, and the harm of complications of diabetes mellitus has ranked third after cancer and cardiovascular and cerebrovascular diseases. Abnormal gastric emptying is one of the common complications of diabetic mellitus, which seriously influences the life quality of the patients. Therefore, it is important to investigate the pathogenesis of abnormal gastric emptying in diabetes mellitus. The role of ghrelin in the pathophysiology of abnormal gastric emptying in diabetes mellitus is a hot area of research now. In this paper, we review the relationship between ghrelin and abnormal gastric emptying in diabetes mellitus.

Phytobezoar leading to gastric outlet obstruction in a patient with diabetes

Gastroparesis is a condition which results in delayed gastric emptying without gastric outflow tract obstruction. Gastrointestinal involvement in diabetes can present in various forms such as oesophageal dysmotility, gastro-oesophageal reflux disease, gastroparesis, enteropathy, non-alcoholic fatty liver disease and glycogenic hepatopathy. Gastroparesis is the most common gastric motility disorder complicating long-standing diabetes. It can sometimes lead to mechanical obstruction as a result of formation of bezoars. Phytobezoars are the most common type of bezoar and are composed of indigestible food, vegetable fibre or seeds. Poor pyloric function and decreased acid formation predisposes phytobezoars formation in patients with diabetic gastroparesis. An 80-year-old patient with diabetes in our presentation developed gastric outlet obstruction due to impaction of phytobezoar over the pylorus.

Neural stem cell therapies for enteric nervous system disorders

The enteric nervous system is vulnerable to a range of congenital and acquired disorders that disrupt the function of its neurons or lead to their loss. The resulting enteric neuropathies are some of the most challenging clinical conditions to manage. Neural stem cells offer the prospect of a cure given their potential ability to replenish missing or dysfunctional neurons. This article discusses diseases that might be targets for stem cell therapies and the barriers that could limit treatment application. We explore various sources of stem cells and the proof of concept for their use. The critical steps that remain to be addressed before these therapies can be used in patients are also discussed. Key milestones include the harvesting of neural stem cells from the human gut and the latest in vivo transplantation studies in animals. The tremendous progress in the field has brought experimental studies exploring the potential of stem cell therapies for the management of enteric neuropathies to the cusp of clinical application.

Gastric emptying and duodenal motility upon intake of a liquid meal with monosodium glutamate in healthy subjects

Glutamate is thought to serve as a special signal for gut functions. We investigated the effects of monosodium l‐glutamate (MSG) on gastric emptying and duodenal motility. Ten healthy male volunteers underwent rapid magnetic resonance imaging (MRI) of the abdomen. Coronal images were successively acquired after ingestion of liquid meal (200 kcal in 200 mL: 9 g protein, 28.4 g carbohydrate, 5.6 g fat, 370 mg Na⁺) with and without 0.5% MSG. During the acquisition of MRI, participants breathed freely. In all participants, the gastric residual volume gradually decreased to 80.1 ± 14.2% without MSG and to 75.9 ± 14.3% with MSG after 60 min (P = 0.45 between the groups, n = 10). In two of 10 participants, gastric emptying slowed down significantly, whereas in the remaining eight participants, gastric residual volume decreased to 84.0 ± 13.1% without MSG, and to 73.0 ± 14.6% with MSG after 60 min (P = 0.015, n = 8). There was no difference in the shape of the stomach between groups. In four of the eight participants responding positively to MSG, the duodenum wall was sufficiently identified to quantify the motions. The inclusion of MSG enhanced duodenal motility, judging from changes in (1) the magnitude of the duodenal area, (2) the center of gravity, and (3) the mean velocity of the wall motions. The third parameter most significantly indicated the excitatory effect of l‐glutamate on duodenum motility (~ three‐ to sevenfold increase during 60 min, P < 0.05, n = 4). These results suggest that MSG accelerates gastric emptying by facilitating duodenal motility, at least in subjects with positive responses to MSG.

The gut and brain share many neurotransmitters and hormones, thereby gut motility frequently reflects mental conditions in humans. So far, procedures to quantify gut motility in vivo have not yet been established. This study of abdominal rapid magnetic resonance imaging (MRI) demonstrates that monosodium L‐glutamate (MSG) accelerates gastric emptying by facilitating duodenal motility, at least in subjects with positive responses to MSG.