EGF and BMPs Govern Differentiation and Patterning in Human Gastric Glands.

BACKGROUND & AIMS: The homeostasis of the gastrointestinal epithelium relies on cell regeneration and differentiation into distinct lineages organized inside glands and crypts. Regeneration depends on Wnt/ß-catenin pathway activation, but to understand homeostasis and its dysregulation in disease, we need to identify the signaling microenvironment governing cell differentiation. By using gastric glands as a model, we have identified the signals inducing differentiation of surface mucus-, zymogen-, and gastric acid-producing cells. METHODS: We generated mucosoid cultures from the human stomach and exposed them to different growth factors to obtain cells with features of differentiated foveolar, chief, and parietal cells. We localized the source of the growth factors in the tissue of origin. RESULTS: We show that epidermal growth factor is the major fate determinant distinguishing the surface and inner part of human gastric glands. In combination with bone morphogenetic factor/Noggin signals, epidermal growth factor controls the differentiation of foveolar cells vs parietal or chief cells. We also show that epidermal growth factor is likely to underlie alteration of the gastric mucosa in the precancerous condition atrophic gastritis. CONCLUSIONS: Use of our recently established mucosoid cultures in combination with analysis of the tissue of origin provided a robust strategy to understand differentiation and patterning of human tissue and allowed us to draw a new, detailed map of the signaling microenvironment in the human gastric glands.

Effects of bariatric surgery on functional connectivity of the reward and default mode network: A pre-registered analysis.

Obesity imposes serious health risks and involves alterations in resting-state functional connectivity of brain networks involved in eating behavior. Bariatric surgery is an effective treatment, but its effects on functional connectivity are still under debate. In this pre-registered study, we aimed to determine the effects of bariatric surgery on major resting-state brain networks (reward and default mode network) in a longitudinal controlled design. Thirty-three bariatric surgery patients and 15 obese waiting-list control patients underwent magnetic resonance imaging at baseline, after 6 and 12 months. We conducted a pre-registered whole-brain time-by-group interaction analysis, and a time-by-group interaction analysis on within-network connectivity. In exploratory analyses, we investigated the effects of weight loss and head motion. Bariatric surgery compared to waiting did not significantly affect functional connectivity of the reward network and the default mode network (FWE-corrected p > .05), neither whole-brain nor within-network. In exploratory analyses, surgery-related BMI decrease (FWE-corrected p = .041) and higher average head motion (FWE-corrected p = .021) resulted in significantly stronger connectivity of the reward network with medial posterior frontal regions. This pre-registered well-controlled study did not support a strong effect of bariatric surgery, compared to waiting, on major resting-state brain networks after 6 months. Exploratory analyses indicated that head motion might have confounded the effects. Data pooling and more rigorous control of within-scanner head motion during data acquisition are needed to substantiate effects of bariatric surgery on brain organization.

Weight loss reduces head motion: Revisiting a major confound in neuroimaging.

Head motion during magnetic resonance imaging (MRI) induces image artifacts that affect virtually every brain measure. In parallel, cross-sectional observations indicate a correlation of head motion with age, psychiatric disease status and obesity, raising the possibility of a systematic artifact-induced bias in neuroimaging outcomes in these conditions, due to the differences in head motion. Yet, a causal link between obesity and head motion has not been tested in an experimental design. Here, we show that a change in body mass index (BMI) (i.e., weight loss after bariatric surgery) systematically decreases head motion during MRI. In this setting, reduced imaging artifacts due to lower head motion might result in biased estimates of neural differences induced by changes in BMI. Overall, our finding urges the need to rigorously control for head motion during MRI to enable valid results of neuroimaging outcomes in populations that differ in head motion due to obesity or other conditions.

A novel human gastric primary cell culture system for modelling Helicobacter pylori infection in vitro.

BACKGROUND AND AIMS: Helicobacter pylori is the causative agent of gastric diseases and the main risk factor in the development of gastric adenocarcinoma. In vitro studies with this bacterial pathogen largely rely on the use of transformed cell lines as infection model. However, this approach is intrinsically artificial and especially inappropriate when it comes to investigating the mechanisms of cancerogenesis. Moreover, common cell lines are often defective in crucial signalling pathways relevant to infection and cancer. A long-lived primary cell system would be preferable in order to better approximate the human in vivo situation. METHODS: Gastric glands were isolated from healthy human stomach tissue and grown in Matrigel containing media supplemented with various growth factors, developmental regulators and apoptosis inhibitors to generate long-lasting normal epithelial cell cultures. RESULTS: Culture conditions were developed which support the formation and quasi-indefinite growth of three dimensional (3D) spheroids derived from various sites of the human stomach. Spheroids could be differentiated to gastric organoids after withdrawal of Wnt3A and R-spondin1 from the medium. The 3D cultures exhibit typical morphological features of human stomach tissue. Transfer of sheared spheroids into 2D culture led to the formation of dense planar cultures of polarised epithelial cells serving as a suitable in vitro model of H. pylori infection. CONCLUSIONS: A robust and quasi-immortal 3D organoid model has been established, which is considered instrumental for future research aimed to understand the underlying mechanisms of infection, mucosal immunity and cancer of the human stomach.

Ghrelin and NUCB2/nesfatin-1 are expressed in the same gastric cell and differentially correlated with body mass index in obese subjects.

The orexigenic peptide ghrelin and the anorexigenic peptide nesfatin-1 are expressed by the same endocrine cell of the rat stomach, the X/A-like cell. However, data in humans are lacking, especially under conditions of obesity. We collected gastric tissue of obese patients undergoing sleeve gastrectomy and investigated the expression of nesfatin-1 and ghrelin in the gastric oxyntic mucosa by immunofluorescence. Nesfatin-1 immunoreactivity was detected in the human oxyntic mucosa in cells with an endocrine phenotype. A major portion of nesfatin-1 immunoreactive cells (78 %) co-localized with ghrelin indicating the occurrence in human X/A-like cells. In patients with very high body mass index (BMI 55-65 kg/m(2)), the number of nesfatin-1 immunoreactive cells/low-power field was significantly higher than in obese patients with lower BMI (40-50 kg/m(2), 118 ± 10 vs. 82 ± 11, p < 0.05). On the other hand, the number of ghrelin immunoreactive cells was significantly reduced in obese patients with higher compared to lower BMI (96 ± 12 vs. 204 ± 21, p < 0.01). Also the ghrelin-acylating enzyme ghrelin-O-acyltransferase decreased with increasing BMI. In conclusion, nesfatin-1 immunoreactivity is also co-localized with ghrelin in human gastric X/A-like cells giving rise to a dual role of this cell type with differential effects on stimulation and inhibition of appetite dependent on the peptide released. The expression of these two peptides is differentially regulated under obese conditions with an increase of nesfatin-1 and a decrease of ghrelin immunoreactivity with rising BMI pointing towards an adaptive change of expression that may counteract further body weight increase.

Bariatric Surgery and Brain Health-A Longitudinal Observational Study Investigating the Effect of Surgery on Cognitive Function and Gray Matter Volume.

Dietary modifications leading to weight loss have been suggested as a means to improve brain health. In morbid obesity, bariatric surgery (BARS)-including different procedures, such as vertical sleeve gastrectomy (VSG), gastric banding (GB), or Roux-en-Y gastric bypass (RYGB) surgery-is performed to induce rapid weight loss. Combining reduced food intake and malabsorption of nutrients, RYGB might be most effective, but requires life-long follow-up treatment. Here, we tested 40 patients before and six months after surgery (BARS group) using a neuropsychological test battery and compared them with a waiting list control group. Subsamples of both groups underwent structural MRI and were examined for differences between surgical procedures. No substantial differences between BARS and control group emerged with regard to cognition. However, larger gray matter volume in fronto-temporal brain areas accompanied by smaller volume in the ventral striatum was seen in the BARS group compared to controls. RYGB patients compared to patients with restrictive treatment alone (VSG/GB) had higher weight loss, but did not benefit more in cognitive outcomes. In sum, the data of our study suggest that BARS might lead to brain structure reorganization at long-term follow-up, while the type of surgical procedure does not differentially modulate cognitive performance.

Improvement in self-reported eating-related psychopathology and physical health-related quality of life after laparoscopic sleeve gastrectomy: A pre-post analysis and comparison with conservatively treated patients with obesity.

OBJECTIVE: The present study examined the effects of laparoscopic sleeve gastrectomy (LSG) on self-reported eating-related psychopathology and health-related quality of life (HRQoL). Outcomes of the LSG group were compared with a group of conservatively treated (CT) patients, who underwent a 1-year multimodal weight reduction group program that included dietary advice, physical exercise, psychoeducation, cognitive-behavioral therapy, training in Jacobson's progressive muscle relaxation, and social group support. The setting was a multidisciplinary obesity center. METHOD: A sample of 103 patients with obesity were investigated using the Eating Disorder Inventory and the Short Form Health Survey before and, on average, 19 (±5) months after weight loss intervention. Thereof, 63 patients (age 45.6±10.9years, 71.4% females) underwent LSG, and 40 patients (age 50.6±11.3years, 77.5% females) underwent the CT program. Patients were assigned to either the surgical or the nonsurgical intervention group following clinical guidelines and patient preference. RESULTS: In the LSG group, excess weight loss (%EWL) was 53.0±24.0%, and body mass index (BMI) decreased from 51.5±8.1 to 38.0±7.7kg/m2. In the CT group, %EWL was 13.9±27.1%, and BMI decreased from 40.3±6.7 to 38.0±7.2kg/m2. Significant improvements in eating-related psychopathology were observed in both groups. Although both groups had a similar BMI after the respective interventions, LSG patients reported significantly greater body satisfaction and substantial improvement in perceived physical health from a lower baseline level than CT patients. DISCUSSION: In the second follow-up year, LSG was associated with greater weight loss from a higher baseline weight, and greater improvements in self-reported eating-related psychopathology and physical HRQoL compared with conservative treatment.

Changes in self-reported eating patterns after laparoscopic sleeve gastrectomy: a pre-post analysis and comparison with conservatively treated patients with obesity.

BACKGROUND: Patients with severe obesity need to adapt to surgically induced changes in their eating behaviors to maintain treatment success. OBJECTIVES: This study examined the effects of laparoscopic sleeve gastrectomy (LSG) on weight loss and on 3 dimensions of eating behavior, namely, cognitive restraint, disinhibition, and hunger. Outcomes of the LSG group were compared with a group of conservatively treated (CT) patients, who underwent a 1-year multimodal weight-reduction group program that included dietary advice, physical exercise, psychoeducation, cognitive-behavioral therapy, training in Jacobson's progressive muscle relaxation, and social group support. SETTING: The study setting was a multidisciplinary obesity center located in a university hospital. METHODS: A sample of 102 patients with obesity were investigated using the Three-Factor Eating Questionnaire before and, on average, 19 (±5) months after weight loss intervention. Of the 102 patients, 62 (age 45.8±10.8 years, 71% females) underwent LSG, and 40 patients (age 50.6±11.3 years, 77.5% females) underwent the CT program. Patients were assigned to either the surgical or the nonsurgical intervention group following clinical guidelines and patient preference. RESULTS: In the LSG group, total weight loss was 25.9±11.0%, excess weight loss was 52.8±24.1%, and body mass index decreased from 51.4±8.1 to 38.0±7.8 kg/m². In the CT group, total weight loss was 5.4±10.6%, excess weight loss was 13.9±27.1%, and body mass index decreased from 40.3±6.7 to 38.0±7.2 kg/m². Significant improvements in self-reported eating behaviors were observed in both groups, that is, an increased cognitive restraint of eating, a decreased disinhibition of eating control, and a reduced degree of perceived hunger. In contrast, whereas Three-Factor Eating Questionnaire scores before weight loss intervention did not differ between groups, LSG patients reported significantly greater reductions in disinhibition and hunger than CT patients did after weight loss intervention. In both groups, greater weight loss was associated with decreased hunger sensations. CONCLUSION: In the second follow-up year, LSG was associated with greater weight loss and greater improvements in self-reported eating behaviors compared with conservative treatment.

Overexpression of COP9 signalosome subunits, CSN7A and CSN7B, exerts different effects on adipogenic differentiation.

The COP9 signalosome (CSN) is an essential regulator of cullin-RING-ubiquitin (Ub) ligases (CRLs), which ubiquitinate important cellular regulators and target them for degradation by the Ub proteasome system (UPS). The CSN exhibits deneddylating activity localized on subunit CSN5, which removes the ubiquitin-like protein Nedd8 from the cullins of CRLs. CSN-mediated deneddylation is an important step in the process of CRL remodeling, in which new substrate recognition units are incorporated into Ub ligases to meet changed requirements for proteolysis in cells. For instance, extensive CRL remodeling occurs during adipogenic differentiation when new CRL3s are formed. Diversification of CSN complexes during evolution is most likely another adaptation to meet different cellular requirements. Best known CSN variants are formed by different CSN subunit isoforms. For instance, in plant cells, isoforms have been identified for the MPN-domain subunits CSN5 (CSN5A and CSN5B) and CSN6 (CSN6A and CSN6B) which form four distinct CSN variants. In mammalian cells CSNCSN7A and CSNCSN7B variants are generated by CSN7 isoforms. We demonstrate that the two variants coexist in human LiSa-2 cells and in mouse embryonic fibroblasts. During adipogenic differentiation of LiSa-2 cells CSN7B increases in parallel with an elevation of the total CSN complex. Permanent overexpression of Flag-CSN7B but not of Flag-CSN7A accelerates adipogenesis in LiSa-2 cells indicating a specific function of the CSNCSN7B variant in stimulating adipogenesis. Silencing of CSN7A as well as of CSN7B in LiSa-2 cells and in mouse embryonic fibroblasts (MEFs) reduces adipogenic differentiation demonstrating that both CSNCSN7A and CSNCSN7B variants are involved in the process.

CAND1 exchange factor promotes Keap1 integration into cullin 3-RING ubiquitin ligase during adipogenesis.

Adipogenesis is governed by a plethora of regulatory proteins which are most commonly controlled by the ubiquitin proteasome system. Here, we show that the differentiation of LiSa-2 preadipocytes is associated with an increase of cullin-associated and neddylation-dissociated 1 (CAND1), COP9 signalosome (CSN), neddylated cullin 3 (Cul3) and the BTB protein Keap1. Silencing of CAND1 leads to a decrease and reduced integration of Keap1 into Cul3-RING ubiquitin ligases (CRL3) and to a retardation of adipogenesis. Transient transfection of LiSa-2 cells with CAND1 targeting miRNA148a also reduces Keap1 and slowed down adipogenesis of LiSa-2 cells. These results demonstrate for the first time that CAND1 acts as a BTB-protein exchange factor for CRL3 complexes. The specific increase of neddylated Cul3 might be explained by the recruitment of Cul3 or CRL3 in a membrane-bound location during adipogenesis. Together, the results show that during adipogenesis in LiSa-2 cells a CAND1-dependent remodeling and activation/neddylation of CRL3 complexes take place.

Determinants of Weight Loss following Laparoscopic Sleeve Gastrectomy: The Role of Psychological Burden, Coping Style, and Motivation to Undergo Surgery.

BACKGROUND: The amount of excess weight loss (%EWL) among obese patients after bariatric surgery varies greatly. However, reliable predictors have not been established yet. The present study evaluated the preoperative psychological burden, coping style, and motivation to lose weight as factors determining postoperative treatment success. METHODS: The sample included 64 morbidly obese patients with a preoperative BMI of 51 ± 8 kg/m(2) who had undergone laparoscopic sleeve gastrectomy (LSG). Well-established questionnaires were applied before surgery to assess the psychological burden in terms of "perceived stress" (PSQ-20), "depression" (PHQ-9), "anxiety" (GAD-7), and "mental impairment" (ISR) as well as coping style (Brief COPE) and motivation to lose weight. %EWL as an indicator for treatment success was assessed on average 20 months after surgery. RESULTS: Based on the %EWL distribution, patients were classified into three %EWL groups: low (14-39%), moderate (40-59%), and high (60-115%). LSG patients with high %EWL reported significantly more "active coping" behavior prior to surgery than patients with moderate and low %EWL. Patients' preoperative psychological burden and motivation to lose weight were not associated with %EWL. CONCLUSION: An "active coping" style might be of predictive value for better weight loss outcomes in patients following LSG intervention.

Local and systemic chemotherapy with taurolidine and taurolidine/heparin in colon cancer-bearing rats undergoing laparotomy.

Experimental studies in the therapy of malignant abdominal tumors have shown that different cytotoxic agents suppress the intraperitoneal tumor growth. Nevertheless, a general accepted approach to prevent tumor recurrences does not exist. Following subcutaneous and intraperitoneal injection of 10(4) colon adenocarcinoma cells (DHD/K12/TRb), the influences of both taurolidine or taurolidine/heparin on intraperitoneal and subcutaneous tumor growth was investigated in 105 rats undergoing midline laparotomy. The animals were randomized into 7 groups and operated on during 30 min. To investigate the intraperitoneal (local) influence of either taurolidine or heparin on tumor growth, the substances were applied intraperitoneally. Systemic and intraperitoneal effects were evaluated after intravenous injection of the substances. Both application forms were also combined to analyze synergistic effects. Tumor weights, as well as the incidence of abdominal wound metastases, were determined four weeks after the intervention. In order to evaluate the effects of the agents, blood was taken to determine the peripheral leukocytes counts. Intraperitoneal tumor growth in rats receiving intraperitoneal application of taurolidine (median 7.0 mg, P = 0.05) and of taurolidine/heparin (median 0 mg, P = 0.02) was significantly reduced when compared to the control group (median 185 mg). The simultaneous instillation of both agents also reduced the intraperitoneal tumor growth (median 4 mg, P = 0.04), while the intravenous injection of the substances caused no local effect. In contrast, the subcutaneous tumor growth did not differ among all groups. In all groups, abdominal wound recurrences were rare and did not differ. Independent of the agents and the application form, the operation itself caused a slight leukopenia shortly after the operation and a leukocytosis in the following course. Intraperitoneal therapy of either taurolidine or in combination with heparin inhibits local tumor growth and abdominal wound recurrences in rats undergoing midline laparotomy. Neither the intraperitoneal nor the intravenous application or the combination of the two agents influenced the subcutaneous tumor growth. The substances did not alter the changes of peripheral leukocytes.

The COP9 signalosome, cullin 3 and Keap1 supercomplex regulates CHOP stability and adipogenesis.

Obesity is one of the most serious health problems of the 21(st) century. It is associated with highly increased risk of type 2 diabetes, high blood pressure, cardiovascular disease as well as several cancers. The expansion of the fat tissue needs the differentiation of preadipocytes to adipocytes, a process called adipogenesis. Dysfunction of adipogenesis is a hallmark of obesity and delineation of underlying mechanisms has high priority for identifying targets for pharmacological intervention. Here we investigate the impact of the COP9 signalosome (CSN), a regulator of cullin-RING ubiquitin ligases (CRLs), and of C/EBP homologous protein (CHOP) on the differentiation of LiSa-2 preadipocytes. CHOP induced by piceatannol or by permanent overexpression in LiSa-2 cells blocks adipocyte differentiation as characterized by inhibited fat droplet formation and vascular endothelial growth factor (VEGF) production. Knockdown of the CSN by permanent downregulation of CSN1 in LiSa-2 cells elevates CHOP and retards adipogenesis. The effect of the CSN knockdown on CHOP stability can be explained by the protection of the CRL component Keap1 by the CSN associated ubiquitin-specific protease 15 (USP15). Pulldowns and glycerol gradients reveal that CHOP interacts with a supercomplex consisting of the CSN, cullin 3 and Keap1. Transient knockdown of Keap1 increases CHOP steady state level and retards its degradation. We conclude that CHOP stability is controlled by a CSN-CRL3(Keap1) complex, which is crucial for adipogenesis. Our data show that CHOP is a distinguished target for pharmacological intervention of obesity.

Isolated amyloid tumor in the mediastinum: report of a case.

Primary amyloidosis isolated in the mediastinum is rarely encountered in thoracic surgery and few such cases have been reported. We present a case of primary isolated hilar amyloidosis of the mediastinum to illustrate the difficulties in differentiating this disorder preoperatively from central bronchial carcinoma, carcinoid tumor, and mediastinal lymphoma. Usually, a definitive diagnosis can only be made by open biopsy during thoracoscopy or thoracotomy. In conclusion, amyloidosis should be considered in the differential diagnosis of patients when calcifications are found, bearing in mind that radiologic findings are inconclusive and transbronchial biopsy can be negative.