Background Growing evidence suggests the key role of ghrelin in the onset and progression of nonalcoholic fatty liver disease (NAFLD). The potential participation of ghrelin and the ghrelin receptor antagonist, LEAP-2, in the onset of liver fibrosis in patients with severe obesity and NAFLD through the regulation of TGF-& beta;1-induced hepatic stellate cell (HSC) activation was investigated. Methods Circulating (n = 179) and hepatic expression (n = 95) of ghrelin and LEAP-2 were measured in patients with severe obesity and available liver pathology analysis undergoing Roux-en-Y gastric bypass (RYGB). The effect of ghrelin isoforms and LEAP-2 on TGF-& beta;1-induced HSC activation, fibrogenic response, and contractile properties was evaluated in vitro in human LX-2 cells. Results Plasma and hepatic ghrelin were negatively associated, while LEAP-2 exhibited a positive association with liver fibrosis in patients with obesity and NAFLD. Six months after RYGB, hepatic function was improved and, although acylated ghrelin and LEAP-2 concentrations remained unchanged, both hormones were inversely related to post-surgical levels of profibrogenic factors TGF-& beta;1 and TIMP-1. Acylated ghrelin treatment reversed TGF-& beta;1-induced myofibroblast-like phenotype, collagen contractile properties, and the upregulation of factors involved in HSC activation and fibrogenesis via PI3K/Akt/mTOR pathway. Moreover, acylated ghrelin inhibited the mild HSC activation induced by LEAP-2. Conclusions Ghrelin is an anti-fibrogenic factor blocking HSC activation induced by the most potent fibrogenic cytokine, TGF-& beta;1, and LEAP-2. The imbalance between acylated ghrelin and ghrelin receptor antagonist LEAP-2 might contribute to maintain liver fibrosis in patients with obesity and NAFLD.

Introduction: Obesity contributes to ectopic fat deposition in non-adipose organs, including the pancreas. Pancreas steatosis associates with inflammation and beta-cell dysfunction, contributing to the onset of insulin resistance and type 2 diabetes. An improvement of pancreatic steatosis and indices of insulin resistance is observed following bariatric surgery, but the underlying mechanisms remain unknown. We sought to analyze whether guanylin (GUCA2A) and uroguanylin (GUCA2B), two gut hormones involved in the regulation of satiety, food preference and adiposity, are involved in the amelioration of pancreas fat accumulation after bariatric surgery. Methods: Pancreas steatosis, inflammation, islet number and area were measured in male Wistar rats with diet-induced obesity (n=125) subjected to surgical (sham operation and sleeve gastrectomy) or dietary (pair-fed to the amount of food eaten by gastrectomized animals) interventions. The tissue distribution of guanylate cyclase C (GUCY2C) and the expression of the guanylin system were evaluated in rat pancreata by real-time PCR, Western-blot and immunohistochemistry. The effect of guanylin and uroguanylin on factors involved in insulin secretion and lipogenesis was determined in vitro in RIN-m5F beta-cells exposed to lipotoxic conditions. Results: Sleeve gastrectomy reduced pancreas steatosis and inflammation and improved insulin sensitivity and synthesis. An upregulation of GUCA2A and GUCY2C, but not GUCA2B, was observed in pancreata from rats with dietinduced obesity one month after sleeve gastrectomy. Interestingly, both guanylin and uroguanylin diminished the lipotoxicity in palmitate-treated RIN-m5F beta-cells, evidenced by lower steatosis and downregulated lipogenic factors Srebf1, Mogat2 and Dgat1. Both guanylin peptides reduced insulin synthesis (Ins1 and Ins2) and release from RIN-m5F beta-cells, but only guanylin upregulated Wnt4, a factor that controls beta-cell proliferation and function. Discussion: Together, sleeve gastrectomy reduced pancreatic steatosis and improved beta-cell function. Several mechanisms, including the modulation of inflammation and lipogenesis as well as the upregulation of GUCA2A in the pancreas, might explain this beneficial effect of bariatric surgery.

Glycerol is a key metabolite for lipid accumulation in insulin-sensitive tissues. We examined the role of aquaporin-7 (AQP7), the main glycerol channel in adipocytes, in the improvement of brown adipose tissue (BAT) whitening, a process whereby brown adipocytes differentiate into white like unilocular cells, after cold exposure or bariatric surgery in male Wistar rats with diet-induced obesity (DIO) (n = 229). DIO promoted BAT whitening, evidenced by increased BAT hypertrophy, steatosis and upregulation of the lipogenic factors Pparg2 , Mogat2 and Dgat1. AQP7 was detected in BAT capillary endothelial cells and brown adipocytes, and its expression was upregulated by DIO. Interestingly, AQP7 gene and protein expressions were downregulated after cold exposure (4( ?)C) for 1 week or one month after sleeve gastrectomy in parallel to the improvement of BAT whitening. Moreover, Aqp7 mRNA expression was positively associated with transcripts of the lipogenic factors Pparg2 , Mogat2 and Dgat1 and regulated by lipogenic (ghrelin) and lipolytic (isoproterenol and leptin) signals. Together, the upregulation of AQP7 in DIO might contribute to glycerol influx used for triacylglycerol synthesis in brown adipocytes, and hence, BAT whitening. This process is reversible by cold exposure and bariatric surgery, thereby suggesting the potential of targeting BAT AQP7 as an anti-obesity therapy.

Simple Summary Netrin-1 (NTN-1) regulates obesity-associated low-grade inflammation, being also involved in the control of cell migration and proliferation. We aim to study whether excess visceral adipose tissue in patients with obesity and colon cancer is associated with increased NTN1 and the expression levels of its main receptors, promoting an inflammatory microenvironment that favours colon cancer development. Increased expression levels of NTN1 and its receptor NEO1 in the visceral adipose tissue from patients with obesity and colon cancer together with elevated DCC and UNC5B mRNA levels in patients with colon cancer were found. Moreover, the treatment of colorectal cancer cells with NTN-1 and with the adipocyte-derived secretome obtained from patients with obesity increased the migration of colorectal cancer cells. These results suggest that NTN-1 plays an important role in obesity-associated colon cancer development. Netrin (NTN)-1, an extracellular matrix protein with a crucial role in inflammation, is dysregulated during obesity (OB) and influences colon cancer (CC) progression. To decipher the mechanisms underlying CC development during obesity, we examined the expression of NTN1 and its receptors in the visceral adipose tissue (VAT) of 74 (25 normal weight (NW)) (16 with CC) and 49 patients with OB (12 with CC). We also evaluated the effect of caloric restriction (CR) on the gene expression levels of Ntn1 and its receptors in the colon from a rat model fed a normal diet. The impact of adipocyte-conditioned media (ACM) from patients with OB and NTN-1 was assessed on the expression levels of neogenin 1(NEO1), deleted in colorectal carcinomas (DCC) and uncoordinated-5 homolog B (UNC5B) in Caco-2 and HT-29 human colorectal cell lines, as well as on Caco-2 cell migration. Increased NTN1 and NEO1 mRNA levels in VAT were due to OB (p < 0.05) and CC (p < 0.001). In addition, an upregulation in the expression levels of DCC and UNC5B in patients with CC (p < 0.01 and p < 0.05, respectively) was observed. Decreased (p < 0.01) Ntn1 levels in the colon from rats submitted to CR were found. In vitro experiments showed that ACM increased DCC (p < 0.05) and NEO1 (p < 0.01) mRNA levels in HT-29 and Caco-2 cell lines, respectively, while UNC5B decreased (p < 0.01) in HT-29. The treatment with NTN-1 increased (p < 0.05) NEO1 mRNA levels in HT-29 cells and DCC (p < 0.05) in both cell lines. Finally, we revealed a potent migratory effect of ACM and NTN-1 on Caco-2 cells. Collectively, these findings point to increased NTN-1 during OB and CC fuelling cancer progression and exerting a strong migratory effect on colon cancer cells.

INTRODUCTION: Laparoscopic resection of the pancreas (LRP) has been implemented to a varying degree because it is technically demanding and requires a long learning curve. In the present study we analyze the risk factors for complications and hospital readmissions in a single center study of 105 consecutive LRPs. METHODS: We conducted a retrospective study using a prospective database. Data were collected on age, gender, BMI, ASA score, type of surgery, histologic type, operative time, hospital stay, postoperative complications, degree of severity and hospital readmission. RESULTS: The cohort included 105 patients, 63 females and 42 males with a median age and BMI of 58 (53-70) and 25.5 (22,2-27.9) respectively. Eighteen (17%) central pancreatectomies, 5 (4.8%) enucleations, 81 (77.6%) distal pancreatectomies and one total pancreatectomy were performed. Fifty-six patients (53.3%) experienced some type of complication, of which 13 (12.3%) were severe (Clavien-Dindo > IIIb) and 11 (10.5%) patients were readmitted in the first 30 days after surgery. In the univariate analysis, age, male gender, ASA score, central pancreatectomy and operative time were significantly associated with the development of complications (P <0.05). In the multivariate analysis, male gender (OR 7.97; 95% CI 1.08-58.88)), severe complications (OR 59.40; 95% CI, 7.69-458.99), and the development of intrabdominal collections (OR 8.97; 95% CI, 1.28-63.02)) were associated with hospital readmission. CONCLUSIONS: Age, male gender, ASA score, operative time and central pancreatectomy are associated with a higher incidence of complications. Male gender, severe complications and intraabdominal collections are associated with more hospital readmissions.

Background: The biological mediators supporting the resolution of liver steatosis, inflammation and fibrosis after bariatric surgery in patients with obesity and NAFLD remain unclear. We sought to analyze whether uroguanylin and guanylin, two gut hormones involved in the regulation of satiety, food preference and adiposity, are involved in the amelioration of obesity-associated NAFLD after bariatric surgery. Methods: Proguanylin (GUCA2A) and prouroguanylin (GUCA2B) were measured in 214 participants undergoing bariatric surgery with biopsy-proven NAFLD diagnosis. Pathways involved in lipid metabolism, mitochondrial network and fibrogenesis were evaluated in liver biopsies (n = 137). The effect of guanylin and uroguanylin on these metabolic functions was assessed in HepG2 hepatocytes and LX-2 hepatic stellate cells (HSC) under lipotoxic and profibrogenic conditions.Results: Plasma and hepatic expression of GUCA2B were decreased in obesity-associated NAFLD. Both GUCA2A and GUCA2B levels were increased after sleeve gastrectomy and Roux-en-Y gastric bypass in parallel to the improved liver function. The liver of patients with type 2 diabetes showed impaired mitochondrial & beta;-oxidation, biogenesis, dynamics as well as increased fibrosis. Uroguanylin diminished the lipotoxicity in palmitate-treated HepG2 hepatocytes, evidenced by decresased steatosis and lipogenic factors, as well as increased mitochondrial network expression, AMPK-induced & beta;-oxidation and oxygen consumption rate. Additionally, uroguanylin, but not guanylin, reversed HSC myofibroblast transdifferentiation as well as fibrogenesis after TGF-& beta;1 stimulation.Conclusions: Uroguanylin constitutes a protective factor against lipotoxicity, mitochondrial dysfunction and fibrosis. Increased GUCA2B levels might contribute to improve liver injury in patients with obesity-associated NAFLD after bariatric surgery.

Acute pancreatitis (AP) is the third most frequent cause of hospital admissions for digestive disorders in the US and Europe after digestive bleeding and cholelithiasis/cholecystitis. The incidence of AP ranges from 15 to 100 cases per 100,000 inhabitants per year, and has been steadily increasing in recent years. In Spain, the reported incidence is 72 patients per 100,000 inhabitants per year. The most frequent cause is biliary lithiasis (50 %-60 % of cases); fortunately, 80 % of patients have only mild symptoms¿as defined by the revised Atlanta Classification¿and progress favorably, although mortality rate is 4.2 %. Clinical guidelines explicitly indicate that laparoscopic cholecystectomy should be performed during the first 48-72 hours or at the time of hospital admission in mild cases of biliary origin.

Biomechanical properties of adipose tissue (AT) are closely involved in the development of obesity associated comorbidities. Bariatric surgery (BS) constitutes the most effective option for a sustained weight loss in addition to improving obesity-associated metabolic diseases including type 2 diabetes (T2D). We aimed to determine the impact of weight loss achieved by BS and caloric restriction (CR) on the biomechanical properties of AT. BS but not CR changed the biomechanical properties of epididymal white AT (EWAT) from a diet-induced obesity rat model, which were associated with metabolic improvements. We found decreased gene expression levels of collagens and Lox together with increased elastin and Mmps mRNA levels in EWAT after BS, which were also associated with the biomechanical properties. Moreover, an increased blood vessel density was observed in EWAT after surgery, confirmed by an up regulation of Acta2 and Antxr1 gene expression levels, which was also correlated with the biomechanical properties. Visceral AT from patients with obesity showed increased stiffness after tensile tests compared to the EWAT from the animal model. This study uncovers new insights into EWAT adaptation after BS with decreased collagen crosslink and synthesis as well as an increased degradation together with enhanced blood vessel density providing, simultaneously, higher stiffness and more ductility. Statement of Significance Biomechanical properties of the adipose tissue (AT) are closely involved in the development of obesity associated comorbidities. In this study, we show for the first time that biomechanical properties of AT determined by E , UTS and strain at UTS are decreased in obesity, being increased after bariatric surgery by the promotion of ECM remodelling and neovascularization. Moreover, these changes in biomechanical properties are associated with improvements in metabolic homeostasis. Consistently, a better characterization of the plasticity and biomechanical properties of the AT after bariatric surgery opens up a new field for the development of innovative strategies for the reduction of fibrosis and inflammation in AT as well as to better understand obesity and its associated comorbidities.

Background and aim: fifty to 70 percent of pancreatic neuro-endocrine tumors are diagnosed incidentally. The objective of this study was to compare the phenotype and oncologi-cal outcomes of incidental versus symptomatic pancreatic neuroendocrine tumors. Methods: a retrospective study was performed, identifying all incidental and symptomatic tumors resected between 2000 and 2019. Baseline characteristics, symptoms, oper-ative variables and pathological stage were all recorded. Patterns of recurrence and overall and disease-free survival were analyzed in both groups. Results: fifty-one incidental and 45 symptomatic pancreat-ic tumor resections were performed. Symptomatic tumors were more frequent in females (29 vs 17; p = 0.005) and younger patients (median years; 50 vs 58; p = 0.012) and were detected at a more advanced stage (p = 0.027). There were no differences in location and most resections (n = 49; 51 %) were performed laparoscopically. There were no operative mortalities and 17 (17.7 %) severe com-plications (>_ IIIb on the Clavien-Dindo classification) were recorded with no differences between the two groups. With a median follow-up of 64.4 months (range 13.5-90), overall survival at five and ten years was 89.7 % and 72.8 % for the non-incidental tumors and 80.9 % and 54.6 % for the incidental tumors (p = ns), respectively. Disease-free survival in both groups (excluding M1a) was 71.2 % and 47.5 %, and 93.7 % and 78.1 %, respectively (p = ns). Conclusions: symptomatic tumors are more frequent in females and present at more advanced pathological stag-es. There were no significant differences in overall and disease-free survival between the two groups. Resection of incidental tumors >_ 1.5-2 cm seems advisable, although each case should be assessed on an individual basis.

Obesity is a worldwide main health concern, with a high treatment failure. This chapter focuses on the definition of obesity, based on excessive fat accumulation and thus underscores the importance of body composition, and the clinical tools currently used to diagnose it, mainly body mass index that is only a proxy measure of body composition. It also highlights the importance of the personal commitment to comply to a healthy diet and physical activity recommendations since surgery is most effective when accompanied by lifestyle modifications. Additionally, it addresses the description of types of patients who could benefit most from surgical management of excessive body fat percentage and metabolic derangements, as well as on the indications for surgery that are currently valid.