Spleen-derived interleukin-10 downregulates the severity of high-fat diet-induced non-alcoholic fatty pancreas disease. PLoS One. 2012;7:e53154. [PMID: 23285260 PMCID: PMC3532347 DOI: 10.1371/journal.pone.0053154]

Characterization of small RNAs in the spleen of MASH in a non-human primate model

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its advanced stage, metabolic dysfunction-associated steatohepatitis (MASH), are increasingly recognized as a global health issue. This study examines the role of small RNAs in the spleen of MASH using a non-human primate model. We performed high-throughput small RNA sequencing on spleen tissues from MASH-primates, revealing significant alterations in the expression of small non-coding RNAs, especially miRNAs. Notably, miR-96, miR-182, miR-183, and miR-122 showed differential expression in MASH spleens. Predictive and validation studies have identified potential target genes, such as PTX3 and NFIX, that were significantly dysregulated in spleens of MASH. These findings characterized small RNAs in spleen of MASH and offer a novel insight for further research for MASH.

Central obesity and fat-free mass are associated with a larger spleen volume in the general population

Background and aim

As the spleen plays a significant role in immunity, the aim was to investigate the associations of different body composition markers derived from various sources with spleen volume in a general population sample.

Materials and methods

Cross-sectional data of 1095 individuals (570 women; 52%) aged between 30 and 90 years were collected in the Study of Health in Pomerania (SHIP-START-2). We measured spleen volume by magnetic resonance imaging (MRI).Body composition markers were derived from classic anthropometry, bioelectrical impedance analysis, including absolute fat mass (FM) and fat-free mass (FFM), as well as from MRI, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and liver fat content. Sex-stratified-adjusted linear regression models were used to analyze the associations of body composition markers with spleen volumes.

Results

We observed positive associations of body mass index, body weight, waist circumference, hip circumference, waist-to-height ratio, absolute FM, absolute FFM, and VAT and SAT with spleen volume in men and women. An 8.12 kg higher absolute FFM was associated with a 38.4 mL (95% confidence interval [CI]: 26.7-50.1) higher spleen volume in men and a 5.21 kg higher absolute FFM with a 42.6 mL (95% CI: 26.2-59.0) higher spleen volume in women.

Conclusion

Our findings indicate that obesity-related body composition markers and FFM are associated with a higher spleen volume. Particularly, higher absolute FFM showed a strong association with a larger spleen volume in both men and women. Further studies are warranted to understand the clinical significance of body composition markers on large spleen volume.

Beneficial Effects of 6-Gingerol on Fatty Pancreas Disease in High-Fat High-Fructose Diet-Induced Metabolic Syndrome Rat Model

OBJECTIVE

To examine the effects of 6-gingerol (6-G) in overcoming fatty pancreas disease of high-fat high-fructose (HFHF) diet-induced metabolic syndrome in rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats were randomly divided into 5 groups. The healthy-control group (normal diet, n = 5) received a standard diet. The HFHF group (HFHF; n = 20) received an HFHF diet and a single-dose intraperitoneal injection of streptozotocin (22 mg/kgBW) at week 8. Metabolic syndrome-confirmed rats received 6-G at doses of 50 (6-G 50, n = 5), 100 (6-G 100, n = 5), and 200 (6-G 200, n = 5) mg/kgBW, respectively, for 8 weeks. All rats were killed at week 16. Pancreatic tissue and blood samples were obtained for histological and amylase analysis.

RESULTS

The serum amylase, MDA, mRNA of TNF-α, and IL-6 significantly increased, whereas GPx decreased in the HFHF group as compared with the normal diet group, respectively. Rats in the HFHF group showed pancreatic lipid accumulation and a decreased mean number of α- and β-cells in the pancreas. Meanwhile, all rats in 6-G at all dose groups showed improvement in all parameters and histopathological scores for lipid accumulation.

CONCLUSIONS

6-Gingerol could attenuate pancreatic lipid accumulation and improve the cell number of α- and β-cells in the pancreas, leading to improvements in fatty pancreas disease.

Pancreatic steatosis is an independent risk factor for post-transplant diabetes mellitus in kidney transplant patients

BACKGROUND AND AIM

Post-transplant diabetes mellitus (PTDM) is associated with an increased risk of post-transplant cardiovascular diseases, and several risk factors of PTDM have been shown in the literature. Yet, the relationship between hepatic and pancreatic steatosis with post-transplant diabetes mellitus remains vague. We aimed to evaluate pancreatic steatosis, a novel component of metabolic syndrome, and hepatic steatosis association with post-transplant diabetes mellitus in a single-center retrospective cohort study conducted on kidney transplant recipients.

METHOD

We have performed a single-center retrospective cohort study involving all kidney transplant recipients. We have utilized pretransplant Fibrosis-4, nonalcoholic fatty liver disease fibrosis score, and abdominal computed tomography for the assessment of visceral steatosis status.

RESULTS

We have included 373 kidney transplant recipients with a mean follow-up period of 32 months in our final analysis. Post-transplant diabetes mellitus risk is associated with older age (p < .001), higher body-mass index (p < .001), nonalcoholic fatty liver disease-fibrosis score (p = .002), hepatic (p < .001) or pancreatic (p < .001) steatosis on imaging and higher pre-transplant serum triglyceride (p = .003) and glucose levels (p = .001) after multivariate analysis.

CONCLUSION

Our study illustrates that recipients' pancreatic steatosis is an independent predictive factor for post-transplant diabetes mellitus including in kidney transplant patients.

Intrapancreatic fat deposition and nutritional treatment: the role of various dietary approaches

Ectopic fat accumulation in various organs and tissues, such as the liver, muscle, kidney, heart, and pancreas, is related to impaired capacity of adipose tissue to accumulate triglycerides, as a consequence of overnutrition and an unhealthy lifestyle. Ectopic fat promotes organ dysfunction and is a key factor in the development and progression of cardiometabolic diseases. Interest in intrapancreatic fat deposition (IPFD) has developed in the last few years, particularly in relation to improvement in methodological techniques for detection of fat in the pancreas, and to growing evidence for the role that IPFD might have in glucose metabolism disorders and cardiometabolic disease. Body weight reduction represents the main option for reducing fat, and the evidence consistently shows that hypocaloric diets are effective in reducing IPFD. Changes in diet composition, independently of changes in energy intake, might offer a more feasible and safe alternative treatment to energy restriction. This current narrative review focused particularly on the possible beneficial role of the diet and its nutrient content, in hypocaloric and isocaloric conditions, in reducing IPFD in individuals with high cardiometabolic risk, highlighting the possible effects of differences in calorie quantity and calorie quality. This review also describes plausible mechanisms by which the various dietary approaches could modulate IPFD.

Intrapancreatic fat, pancreatitis, and pancreatic cancer

Pancreatic cancer is typically detected at an advanced stage, and is refractory to most forms of treatment, contributing to poor survival outcomes. The incidence of pancreatic cancer is gradually increasing, linked to an aging population and increasing rates of obesity and pancreatitis, which are risk factors for this cancer. Sources of risk include adipokine signaling from fat cells throughout the body, elevated levels of intrapancreatic intrapancreatic adipocytes (IPAs), inflammatory signals arising from pancreas-infiltrating immune cells and a fibrotic environment induced by recurring cycles of pancreatic obstruction and acinar cell lysis. Once cancers become established, reorganization of pancreatic tissue typically excludes IPAs from the tumor microenvironment, which instead consists of cancer cells embedded in a specialized microenvironment derived from cancer-associated fibroblasts (CAFs). While cancer cell interactions with CAFs and immune cells have been the topic of much investigation, mechanistic studies of the source and function of IPAs in the pre-cancerous niche are much less developed. Intriguingly, an extensive review of studies addressing the accumulation and activity of IPAs in the pancreas reveals that unexpectedly diverse group of factors cause replacement of acinar tissue with IPAs, particularly in the mouse models that are essential tools for research into pancreatic cancer. Genes implicated in regulation of IPA accumulation include KRAS, MYC, TGF-β, periostin, HNF1, and regulators of ductal ciliation and ER stress, among others. These findings emphasize the importance of studying pancreas-damaging factors in the pre-cancerous environment, and have significant implications for the interpretation of data from mouse models for pancreatic cancer.

A long-term anti-inflammation markedly alleviated high-fat diet-induced obesity by repeated administrations of overexpressing IL10 human umbilical cord-derived mesenchymal stromal cells

Objectives

Obesity is a chronic process and could activate various inflammatory responses, which in turn aggravates obesity and related metabolic syndrome. Here we explored whether long-term inhibition of inflammation could successfully alleviate high-fat diet (HFD)-induced obesity.

Methods

We constructed stable overexpressing interleukin 10 (IL10) human umbilical cord-derived mesenchymal stromal cells (HUCMSCs) which repeatedly were applied to obesity mice with HFD feeding to obtain a long-term anti-inflammation based on the prominent anti-inflammation effects of IL10 and immunomodulatery effects of HUCMSCs. Then we monitored the features of obesity including body weight, serum ALT, AST, and lipids. In addition, glucose homeostasis was determined by glucose tolerance and insulin sensitivity tests. The infiltrated macrophages in adipose tissues and hepatic lipid accumulation were detected, and the expressions of adipogenesis and inflammatory genes in adipose tissues were examined by real-time (RT) PCR and western blot analysis.

Results

Compared with HUCMSCs, IL10-HUCMSCs treatment had much better anti-obesity effects including body weight reduction, less hepatic lipids accumulation, lower amount and size of adipocyte, greater glucose tolerance, less systemic insulin resistance, and less adipose tissue inflammation in HFD feeding mice. Finally, IL10-HUCMSCs could decrease the activation of MAPK JNK of adipose tissue induced by HFD. The inhibition of MAPK JNK signal pathway by a small chemical molecule SP600125 in 3T3-L1 cells, a preadipocyte line, reduced the differentiation of adipocytes and lipid droplet accumulation.

Conclusion

A lasting anti-inflammation based on gene modified stem cell therapy is an effective strategy in preventing diet-induced obesity and obesity-related metabolic syndrome.

Uniting epidemiology and experimental models: pancreatic steatosis and pancreatic cancer

Research from epidemiologic studies and experimental animal models provide insights into the role of pancreatic steatosis in the development of pancreatic cancer. Epidemiologic data demonstrate that pancreatic steatosis is widely prevalent and significantly associated with both development and progression of pancreatic cancer. By focusing on current experimental models, this review elucidates potential cellular mechanisms underlying not only the pathophysiology of pancreatic steatosis itself, but also the pathogenesis behind pancreatic steatosis's role in changing the tumour microenvironment and accelerating the development of pancreatic cancer. This review further explores the impact of bariatric surgery on pancreatic steatosis and pancreatic cancer. Synthesizing knowledge from both epidemiologic studies and experimental animal models, this review identifies gaps in current knowledge regarding pancreatic steatosis and its role in carcinogenesis and proposes future research directions to elucidate the possible mechanisms underlying other obesity-associated cancers.

Fatty Pancreas-Centered Metabolic Basis of Pancreatic Adenocarcinoma: From Obesity, Diabetes and Pancreatitis to Oncogenesis

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest types of cancer, and it is currently the third most common cause of cancer death in the U.S.A. Progress in the fight against PDAC has been hampered by an inability to detect it early in the overwhelming majority of patients, and also by the reduced oxygen levels and nutrient perfusion caused by new matrix formation through the activation of stromal cells in the context of desmoplasia. One harbinger of PDAC is excess intrapancreatic fat deposition, namely, fatty pancreas, which specifically affects the tumor macro- and microenvironment in the organ. Over half of PDAC patients have diabetes mellitus (DM) at the time of diagnosis, and fatty pancreas is associated with subsequent DM development. Moreover, there is a strong association between fatty pancreas and fatty liver through obesity, and a higher intrapancreatic fat percentage has been noted in acute pancreatitis patients with DM than in those without DM. All these findings suggest that the link between fatty pancreas and PDAC might occur through metabolic alterations, either DM-related or non-DM-related. Based on clinical, in vivo and in vitro evidence, the current review highlights the etiologies of fatty pancreas (including fatty infiltration and replacement) and the fatty pancreas-associated metabolic alterations involved in oncogenesis to provide crucial targets to prevent, detect, and/or effectively treat PDAC.

Dietary Sodium Nitrite Causes Similar Modifications to Splenic Inflammatory Gene Expression as a High-Fat Diet

Sodium nitrite (NaNO₂) is a widely used food additive. The present study compared the outcomes from intakes of dietary NaNO₂ and a high-fat diet (HFD), and assessed their combined effects on inflammatory gene expression in the immune tissues of the mouse. In experiment I, mice were fed a standard low-fat diet (LFD) without or with NaNO₂ (0.02 and 0.08%, w/w) for 11 wk. In experiment II, mice were fed an LFD without or with NaNO₂ (0.02%) or HFD without or with NaNO₂ (0.02%) for 11 wk. Inflammatory gene expression in the immune tissues was then measured. NaNO₂ consumption and HFD feeding each resulted in increased splenic mRNAs for cell markers of neutrophils (Ngp, NE, Ly6g, Mpo) and eosinophils (Epo, Ear6), and an S100 family member (S100A8). In contrast, NaNO₂ consumption and HFD feeding each resulted in decreased splenic mRNAs for cell markers of macrophages (Emr1, Itgax, CD68, CD206, Dectin-1, TLRs 4, 6, and 7), T- (CD3, CD4), NK- (CD56) and B-cells (CD20, CD40), pro- and anti-inflammatory cytokines (TNF-α, IL-6, IL-1β, IFN-γ, IL-18, IL-10, TGF-β), interleukin receptor antagonists (IL1ra, IL6ra) and cell adhesion molecules (ICAM-1, VCAM-1). However, dietary NaNO₂ combined with HFD feeding caused no further decrease in these transcript levels compared with dietary NaNO₂ alone. These NaNO₂- or HFD-induced modifications were less profound in the liver and abdominal adipose tissues than in the spleen. These findings indicate that dietary NaNO₂ has similar modulatory effects to HFD feeding on splenic inflammatory genes.

MELATONIN IMPROVES SPLEEN HISTOPHYSIOLOGY OF RATS WITH DIET-INDUCED OBESITY: CHRONOTHERAPY APPROACH

One of the most commoncharacteristics of obesity is the development of a systemic low-grade proinflammatory state in the entire body, including the immune organs. Spleen enlargement during diet-induced obesity contributes to the development of chronic inflammation. Melatonin due to immunomodulatory, antioxidant, and systemic metabolic rolesis proposed to be an effective candidate for anti-obesity therapy. As immune systems demonstrate pronounced circadian rhythmicity and immune cells have different types of melatonin receptors, a chronotherapeutic approach might be used to choose the most effective regimes of melatonin administration for the correction of obesity-provoked damage to the spleen. Thus, the main goal of our research was the analysis of the rats' spleen histophysiology during the development of high-calorie diet-inducedobesity (HCD) after administering melatonin daily at different times (morning or evening). Melatonin was administered by gavage for 7 weeks in the dose of 30 mg/kg 1 h before lights-off (HCD ZT11, M ZT11, evening), or 1 h after lights-on (HCD ZT01, M ZT01, morning). For assessment of the morpho-functional state of the spleen,the histopathological evaluation of red and white pulp in different zones of lymphoid follicles was implemented. It was observed that obesity development wasaccompaniedbyhyperemia and vessel dilatation in the red pulp; while in the white pulp notable deformation of germinal centers and destroyed borders between zones of lymphoid follicles were noticed.The HCD group demonstrated a decrease inthe relative amount of the white pulp, the crosssectional area of germinal centers, and the cross-sectional area of the marginal zone; whilethe increased relative amount of red pulp and marginal zone/germinal centers ratiowere detected compared with control. Melatonin administration to obese rats increases the relative amount of the white pulp (HCD ZT11 group), the cross-sectional area of germinal centers (HCD ZT01 and HCD ZT11 groups), and the cross-sectional area of the marginal zone (HCD ZT11 group), and decreasesmarginal zone/germinal centers ratio (HCD ZT01 group) in comparison with the HCD group.Also,it was demonstrated that a choice between the morning or evening regimes of the melatonin treatment did not affect the histophysiology of the spleen in rats receivingthe standard diet (M ZT01 and M ZT11 groups). These results indicate that melatonin can be considered to be a powerful potential therapeutic agent for the amelioration of obesity-induced changes in the spleen.

Sex-specific regulation of IL-10 production in human adipose tissue in obesity

BACKGROUND

Obesity-associated metabolic complications display sexual dimorphism and can be impacted by cytokines. We previously showed that interleukin-10 (IL-10) was upregulated in white adipose tissue (WAT) of obese women with type 2 diabetes (T2D). Whether this pertains to men is unknown. The aim of this study was to compare the impact of obesity and T2D on WAT IL-10 levels in men versus women.

METHODS

Plasma and subcutaneous WAT biopsies were obtained from 108 metabolically well-characterized individuals. WAT IL10 expression/secretion and WAT-resident IL-10-secreting macrophage number were measured. Circulating sex hormone levels were correlated to WAT IL10 expression in 22 individuals and sex hormone effects on macrophage IL10 expression were investigated in vitro.

RESULTS

Obese women with T2D showed increased IL10 expression/secretion and IL-10-secreting WAT macrophage number compared to other female groups. This difference was absent in men. Non-obese women and men with T2D showed similar IL-10 levels compared to healthy controls, indicating that T2D alone does not regulate IL-10. Although WAT IL10 expression correlated with serum estrone (E1) concentrations, recombinant E1 did not affect macrophage IL10 expression in vitro.

CONCLUSION

WAT IL-10 levels are higher in women with obesity and T2D, but not in men and this effect is primarily attributed to obesity per se. This is less likely to be driven by circulating sex hormones. We propose that the WAT IL-10 might exert protective effects in obesity-associated chronic inflammation in women which could be one of the contributing factors for the decreased morbidity observed in women during obesity than men.

Nonalcoholic fatty pancreas disease: An emerging clinical challenge

Nonalcoholic fatty pancreas disease (NAFPD) is an emerging disease that has gained an increasing amount of attention in recent years. It describes fat accumulation in the pancreas with insignificant alcohol consumption, but the pathogenesis is largely unknown. A wide range of terms have been used to describe the phenomenon of pancreatic fat accumulation, but NAFPD remains an under-recognized and non-independent disorder. Obesity, age, sex, race, and unhealthy lifestyle are established independent risk factors for NAFPD, which is strongly associated with metabolic syndrome, type 2 diabetes, pancreatitis, pancreatic fistula, pancreatic cancer, and nonalcoholic fatty liver disease. At present, imaging techniques are common diagnostic aids, but uniform criteria and consensus are lacking. Therapeutically, healthy diet, weight loss, and exercise are the mainstays to reduce pancreatic fat accumulation. It can be seen that there is a limited understanding of NAFPD at this stage and further exploration is needed. Previous studies have revealed that NAFPD may directly affect diagnosis and clinical decision-making. Therefore, exploring the pathophysiological mechanism and clinical associations of NAFPD is a major challenge for researchers and clinicians.

Vagotomy and Splenectomy Reduce Insulin Secretion and Interleukin-1β

OBJECTIVES

This study aimed to evaluate the effect of vagotomy, when associated with splenectomy, on adiposity and glucose homeostasis in Wistar rats.

METHODS

Rats were divided into 4 groups: vagotomized (VAG), splenectomized (SPL), VAG + SPL, and SHAM. Glucose tolerance tests were performed, and physical and biochemical parameters evaluated. Glucose-induced insulin secretion and protein expression (Glut2/glucokinase) were measured in isolated pancreatic islets. Pancreases were submitted to histological and immunohistochemical analyses, and vagus nerve neural activity was recorded.

RESULTS

The vagotomized group presented with reduced body weight, growth, and adiposity; high food intake; reduced plasma glucose and triglyceride levels; and insulin resistance. The association of SPL with the VAG surgery attenuated, or abolished, the effects of VAG and reduced glucose-induced insulin secretion and interleukin-1β area in β cells, in addition to lowering vagal activity.

CONCLUSIONS

The absence of the spleen attenuated or blocked the effects of VAG on adiposity, triglycerides and glucose homeostasis, suggesting a synergistic effect of both on metabolism. The vagus nerve and spleen modulate the presence of interleukin-1β in β cells, possibly because of the reduction of glucose-induced insulin secretion, indicating a bidirectional flow between autonomous neural firing and the spleen, with repercussions for the endocrine pancreas.

Substance P blocks β-aminopropionitrile-induced aortic injury through modulation of M2 monocyte-skewed monocytopoiesis

Aortic injuries, including aortic aneurysms and dissections, are fatal vascular diseases with distinct histopathological features in the aortic tissue such as inflammation-induced endothelial dysfunction, infiltration of immune cells, and breakdown of the extracellular matrix. Few treatments are available for treating aortic aneurysms and dissections; thus, basic and clinical studies worldwide have been attempted to inhibit disease progression. Substance P (SP) exerts anti-inflammatory effects and promotes restoration of the damaged endothelium, leading to vasculature protection and facilitation of tissue repair. This study was conducted to explore the protective effects of systemically injected SP on thoracic aortic injury (TAI). A TAI animal model was induced by orally administering β-aminopropionitrile to rats for 6 weeks. β-aminopropionitrile blocked crosslinking ECM in aorta to cause structural alteration with inflammation within 1 week and then, induced aortic dissection within 4 weeks of initiating treatment, leading to mortality within 6 weeks. Treatment of TAI rats with SP-induced anti-inflammatory responses systemically and locally, possibly by enriching anti-inflammatory M2 monocytes in the spleen and peripheral blood at early phase of aortic injury due to β-aminopropionitrile. SP-induced immune suppression finally prevented the development of aortic dissection by limiting inflammation-mediated aortic destruction. Taken together, these results suggest that SP treatment can block aortic injury by controlling the immune-cell profile and suppressing proinflammatory responses during the initial stage of vascular disease progression.

Research status and prgoress of nonalcoholic fatty pancreatic disease

Nonalcoholic fatty pancreatic disease (NAFPD) is a disease characterized by an increase in pancreatic fat accumulation. It is a component of the metabolic syndrome and often coexists with nonalcoholic fatty liver disease. Once the diagnosis is established, it is closely related to acute and chronic pancreatitis, type 2 diabetes mellitus, pancreatic fibrosis, and pancreatic cancer. In recent years, it has been confirmed that NAFPD is closely related to cardiovascular disease, liver fibrosis, and liver cancer. The prevalence of NAFPD ranges between 11% and 69%, and increases with age. It is worth noting that the prevalence in obese children is twice as high as that in non-obese children. The high prevalence rate and complexity of the disease have aroused people's high attention. Therefore, to improve the understanding of NAFPD, fully understand the clinical significance of NAFPD, and further study its pathogenesis, diagnosis, and treatment require the collaboration and joint efforts of multiple disciplines, including hepatopathy, gastroenterology, endocrine metabolism, cardiovascular disease, imaging, pathology, and others. In this paper, we review the clinical significance, pathogenesis, and imaging diagnosis of NAFPD and propose our personal understanding of the key points in future research.

The Role of the Anti-Inflammatory Cytokine Interleukin-10 in Tissue Fibrosis

Significance: Fibrosis is the endpoint of chronic disease in multiple organs, including the skin, heart, lungs, intestine, liver, and kidneys. Pathologic accumulation of fibrotic tissue results in a loss of structural integrity and function, with resultant increases in morbidity and mortality. Understanding the pathways governing fibrosis and identifying therapeutic targets within those pathways is necessary to develop novel antifibrotic therapies for fibrotic disease. Recent Advances: Given the connection between inflammation and fibrogenesis, Interleukin-10 (IL-10) has been a focus of potential antifibrotic therapies because of its well-known role as an anti-inflammatory mediator. Despite the apparent dissimilarity of diseases associated with fibrotic progression, pathways involving IL-10 appear to be a conserved molecular theme. More recently, many groups have worked to develop novel delivery tools for recombinant IL-10, such as hydrogels, and cell-based therapies, such as ex vivo activated macrophages, to directly or indirectly modulate IL-10 signaling. Critical Issues: Some efforts in this area, however, have been stymied by IL-10's pleiotropic and sometimes conflicting effects. A deeper, contextual understanding of IL-10 signaling and its interaction with effector cells, particularly immune cells, will be critical to future studies in the field. Future Directions: IL-10 is clearly a gatekeeper of fibrotic/antifibrotic signaling. The development of novel therapeutics and cell-based therapies that capitalize on targets within the IL-10 signaling pathway could have far-reaching implications for patients suffering from the consequences of organ fibrosis.

Non-alcoholic fatty pancreas disease - practices for clinicians

Obesity is a growing health burden worldwide, increasing the risk for several diseases featuring the metabolic syndrome - type 2 diabetes mellitus, dyslipidemia, non-alcoholic fatty liver disease and cardiovascular diseases. With the increasing epidemic of obesity, a new pathologic condition has emerged as a component of the metabolic syndrome - that of non-alcoholic fatty pancreas disease (NAFPD). Similar to non-alcoholic fatty liver disease (NAFLD), NAFPD comprises a wide spectrum of disease - from deposition of fat in the pancreas - fatty pancreas, to pancreatic inflammation and possibly pancreatic fibrosis. In contrast with NAFLD, diagnostic evaluation of NAFPD is less standardized, consisting mostly in imaging methods. Also the natural evolution of NAFPD and its association with pancreatic cancer is much less studied. Not least, the clinical consequences of NAFPD remain largely presumptions and knowledge about its metabolic impact is limited. This review will cover epidemiology, pathogenesis, diagnostic evaluation tools and treatment options for NAFPD, with focus on practices for clinicians.

Brain-Behavior-Immune Interaction: Serum Cytokines and Growth Factors in Patients with Eating Disorders at Extremes of the Body Mass Index (BMI) Spectrum

Alterations of the immune system are known in eating disorders (EDs), however the importance of cytokine balance in this context has not been clarified. We compared cytokines and growth factors at opposite ends of BMI ranges, in 90 patients classified in relation to BMI, depressive and EDs comorbidities. Serum concentrations of interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF) were determined by a biochip analyzer (Randox Labs). Differences were calculated through ANOVA. Possible predictors of higher cytokine levels were evaluated through regression analysis. IL-1α, IL-10, EGF, and IFN-γ were altered individuals with anorexia nervosa (AN) and binge eating disorder (BED). Night-eating was associated with IL-8 and EGF levels, IL-10 concentrations with post-dinner eating and negatively with sweet-eating, long fasting with higher IFN-γ levels. IL-2 increase was not linked to EDs, but to the interaction of depression and BMI. Altogether, for the first time, IL-1α, IL-10, EGF, and IFN-γ were shown to differ between AN and HCs, and between AN and individuals with obesity with or without BED. Only IL-2 was influenced by depression. Dysfunctional eating behaviors predicted abnormal concentrations of IL-10, EGF, IL-8 and IFN-γ.

A New Role for the Spleen: Aggravation of the Systemic Inflammatory Response in Rats with Severe Acute Pancreatitis

Little is known about the role of the spleen in mediating systemic inflammatory responses in severe acute pancreatitis (SAP). We investigated the role played by the spleen in rats after SAP induction. Splenectomy was performed at designated time points after SAP induction. Pancreatic tissue and serum samples were collected and subjected to histologic, immunohistochemical, and immunologic analyses. After SAP induction, the splenic immune response was enhanced during SAP progression, as shown by the increased diameter of the splenic periarterial lymphatic sheath and the thickness of the splenic marginal zone. Rats with splenectomy developed acute pancreatitis more slowly than rats without splenectomy. In addition, pancreatic tissues of rats with splenectomy contained lower levels of serum amylase, tumor necrosis factor-α, and IL-6 and exhibited less acinar cell death, leukocyte infiltration, and interstitial edema than those of rats without splenectomy. Compared with splenectomy alone, cotreatment with splenectomy and the administration of splenic cells originating from a rat with SAP 12 hours after induction increased systemic inflammation in SAP rats. Splenic factors exacerbated SAP-associated liver and lung injury and accentuated intestinal mucosal barrier dysfunction. Splenectomy altered the serum cytokine profile in rats with SAP. In a rat model of SAP, the spleen exacerbated the systematic inflammatory responses and injury to multiple organs, indicating a new role for the spleen in SAP.

Effect of Sheng-jiang powder on multiple-organ inflammatory injury in acute pancreatitis in rats fed a high-fat diet

BACKGROUND

Obesity worsens inflammatory organ injury in acute pancreatitis (AP), but there is no effective preventive strategy. Sheng-jiang powder (SJP) has been shown to alleviate multiple-organ inflammatory injury in rats with high-fat diet-induced obesity. Hence, SJP is supposed to have an effect on multiple-organ inflammatory injury in AP in rats fed a high-fat diet.

AIM

To explore how obesity may contribute to aggravating inflammatory organ injury in AP in rats and observe the effect of SJP on multiple-organ inflammatory injury in AP in rats fed a high-fat diet.

METHODS

Rats were randomly assigned to a control group (CG), an obese group (OG), and an SJP treatment group (SG), with eight rats per group. The rats in the OG and SG were fed a high-fat diet. From the third week, the rats in the SG were given oral doses of SJP (5 g/kg of body weight). After 12 wk, AP was induced in the three groups. Serum amylase level, body weight, Lee’s index, serum biochemistry parameters, and serum inflammatory cytokine and tissue cytokine levels were assessed, and the tissue histopathological scores were evaluated and compared.

RESULTS

Compared with the CG, serum triglyceride, total cholesterol, interleukin-6, and interleukin-10 levels were significantly higher in the OG, and serum high-density lipoprotein cholesterol level was significantly lower in the OG. Moreover, enhanced oxidative damage was observed in the pancreas, heart, spleen, lung, intestine, liver, and kidney. Evidence of an imbalanced antioxidant defense system, especially in the pancreas, spleen, and intestine, was observed in the obese AP rats. Compared with the OG, serum high-density lipoprotein cholesterol, interleukin-10, and superoxide dismutase expression levels in the pancreas, spleen, and intestine were increased in the SG. Additionally, SJP intervention led to a decrease in the following parameters: body weight; Lee’s index; serum triglyceride levels; serum total cholesterol levels; malondialdehyde expression levels in the pancreas, heart, spleen, lung, and liver; myeloperoxidase expression levels in the lung; and pathological scores in the liver.

CONCLUSION

Obesity may aggravate the inflammatory reaction and pathological multiple-organ injury in AP rats, and SJP may alleviate multiple-organ inflammatory injury in AP in rats fed a high-fat diet.

Sheng-jiang powder ameliorates obesity-induced pancreatic inflammatory injury via stimulating activation of the AMPK signalling pathway in rats

AIM

To investigate the mechanisms by which Sheng-jiang powder (SJP) ameliorates obesity-induced pancreatic inflammatory injury.

METHODS

Sprague-Dawley rats were randomized into three groups: normal group (NG), obese group (HLG), or SJP treatment group (HSG). Obesity was induced by feeding a high-fat diet in the HLG and HSG, while the NG received standard chow. Rats were euthanized after 12 wk, and blood and pancreatic tissues were collected for histopathological analyses. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transforming growth factor beta (TGF-β) expression, serum triglyceride and adiponectin levels, and apoptosis in pancreatic acinar cells were assessed. A high-fat AR42J acinar cell injury model was established using very low-density lipoprotein (VLDL). AR42J acinar cell culture supernatant, treated with different interventions, was applied to seven groups of pancreatic stellate cells (PSCs). The proliferation of PSCs and the expression of fibronectin and type I collagenase were assessed.

RESULTS

Compared with the NG, we found higher pathological scores for pancreatic tissues, lower serum adiponectin levels, higher expression levels of NF-κB in pancreatic tissues and TGF-β in pancreatic inflammatory cells, and increased apoptosis among pancreatic acinar cells for the HLG (P < 0.05). Compared with the HLG, we found reduced body weight, Lee’s index scores, serum triglyceride levels, and pathological scores for pancreatic tissues; higher serum adiponectin levels; and lower expression levels of NF-κB, in pancreatic tissue and TGF-β in pancreatic inflammatory cells for the HSG (P < 0.05). The in vitro studies showed enhanced PSC activation and increased expression levels of fibronectin and type I collagenase after SJP treatment. An adenosine 5‘-monophosphate-activated protein kinase (AMPK) inhibitor inhibited PSC activation.

CONCLUSION

SJP may ameliorate obesity-induced pancreatic inflammatory injury in rats by regulating key molecules of the adiponectin-AMPK signalling pathway.

Fatty pancreas: A possible risk factor for pancreatic cancer in animals and humans

Obesity, type 2 diabetes mellitus (T2DM) and aging are associated with pancreatic cancer risk, but the mechanisms of pancreatic cancer development caused by these factors are not clearly understood. Syrian golden hamsters are susceptible to N‐nitrosobis(2‐oxopropyl)amine (BOP)‐induced pancreatic carcinogenesis. Aging, BOP treatment and/or a high‐fat diet cause severe and scattered fatty infiltration (FI) of the pancreas with abnormal adipokine production and promote pancreatic ductal adenocarcinoma (PDAC) development. The KK‐A^y mouse, a T2DM model, also develops severe and scattered FI of the pancreas. Treatment with BOP induced significantly higher cell proliferation in the pancreatic ducts of KK‐A^y mice, but not in those of ICR and C57BL/6J mice, both of which are characterized by an absence of scattered FI. Thus, we hypothesized that severely scattered FI may be involved in the susceptibility to PDAC development. Indeed, severe pancreatic FI, or fatty pancreas, is observed in humans and is associated with age, body mass index (BMI) and DM, which are risk factors for pancreatic cancer. We analyzed the degree of FI in the non‐cancerous parts of PDAC and non‐PDAC patients who had undergone pancreatoduodenectomy by histopathology and demonstrated that the degree of pancreatic FI in PDAC cases is significantly higher than that in non‐PDAC controls. Moreover, the association with PDAC is positive, even after adjusting for BMI and the prevalence of DM. Accumulating evidence suggests that pancreatic FI is involved in PDAC development in animals and humans, and further investigations to clarify the genetic and environmental factors that cause pancreatic FI are warranted.

Supplementation of grape seed and skin extract to orlistat therapy prevents high-fat diet-induced murine spleen lipotoxicity

Spleen is the largest lymphoid organ and obesity is related to an elevated risk of immunity dysfunction. The mechanism whereby fat adversely affects the spleen is poorly understood. This study was designed to assess the effectiveness of grape seed and skin extract (GSSE) and orlistat (Xenical, Xe) on high-fat diet (HFD)-induced spleen lipotoxicity. Obese rats were treated either with GSSE (4 g/kg body weight) or Xe (2 mg/kg body weight) or GSSE+Xe and monitored for weight loss for 3 months. Animals were then sacrificed and their spleen used for the evaluation of lipotoxicity-induced oxidative stress and inflammation as well as the putative protection afforded by GSSE and Xe treatment. HFD induced body weight gain and glycogen accumulation into the spleen; ectopic deposition of cholesterol and triglycerides and an oxidative stress characterized by increased lipoperoxidation and carbonylation; inhibition of antioxidant enzyme activities, such as catalase, glutathione peroxidase, and superoxide dismutase; depletion of zinc and copper; and a concomitant increase in calcium. HFD also increased plasma pro-inflammatory cytokines, such as interleukin (IL)-6, IL-17A, tumour necrosis factor alpha, and C-reactive protein, and decreased plasma IL-10 and adiponectin. Importantly, GSSE counteracted all the deleterious effects of HFD on spleen (i.e., lipotoxicity, oxidative stress, and inflammation) and the best protection was obtained when combining Xe+GSSE. Combining GSSE with Xe prevented against fat-induced spleen lipotoxicity, oxidative stress, and inflammation; this combination may be beneficial in other diseases related to the spleen.

Diabetes Mellitus and Obesity as Risk Factors for Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest types of cancer. The worldwide estimates of its incidence and mortality in the general population are eight cases per 100,000 person-years and seven deaths per 100,000 person-years, and they are significantly higher in the United States than in the rest of the world. The incidence of this disease in the United States is more than 50,000 new cases in 2017. Indeed, total deaths due to PDAC are projected to increase dramatically to become the second leading cause of cancer-related deaths before 2030. Considering the failure to date to efficiently treat existing PDAC, increased effort should be undertaken to prevent this disease. A better understanding of the risk factors leading to PDAC development is of utmost importance to identify and formulate preventive strategies. Large epidemiologic and cohort studies have identified risk factors for the development of PDAC, including obesity and type 2 diabetes mellitus. This review highlights the current knowledge of obesity and type 2 diabetes as risk factors for PDAC development and progression, their interplay and underlying mechanisms, and the relation to diet. Research gaps and opportunities to address this deadly disease are also outlined.

Spleen-Derived Anti-Inflammatory Cytokine IL-10 Stimulated by Adipose Tissue-Derived Stem Cells Protects Against Type 2 Diabetes

Considering that the spleen plays an important role in the occurrence and development of diabetes, we aimed at investigating the role of the spleen in the treatment of type 2 diabetes (T2D) with adipose tissue-derived stem cells (ADSCs). We established a T2D/splenectomy (SPX) rat model by using high-fat diet/streptozotocin administration with SPX, assessed the therapeutic effects of ADSCs, and explored the possible mechanism. A single ADSC infusion was found to ameliorate hyperglycemia and insulin resistance in diabetic rats, accompanied by a considerable number of ADSCs homing to the spleens in T2D rats. Moreover, four times of infusion of ADSCs resulted in a more significant reduction of blood glucose and insulin resistance, whereas SPX exacerbated hyperglycemia and insulin resistance and attenuated the effects of ADSCs. In addition, ADSC infusion promoted anti-inflammatory cytokine interleukin (IL)-10 expression and inhibited pro-inflammatory cytokines IL-6, IL-1β, and tumor necrosis factor (TNF)-α expression in both the spleen and serum of T2D rats without SPX. ADSCs also inhibited serum IL-6, IL-1β, and TNF-α expression, but cannot promote IL-10 expression in T2D rats with SPX. Therefore, these data indicate that the effect of ADSCs ameliorating hyperglycemia and insulin resistance may be partially through promoting spleen-derived anti-inflammatory cytokine IL-10 expression. These novel findings further confirmed the essential role of the spleen in the ADSC treatment of T2D and provide an important theoretical basis for the potential application of ADSCs in T2D therapy.

Exploring the metabolic syndrome: Nonalcoholic fatty pancreas disease

After the first description of fatty pancreas in 1933, the effects of pancreatic steatosis have been poorly investigated, compared with that of the liver. However, the interest of research is increasing. Fat accumulation, associated with obesity and the metabolic syndrome (MetS), has been defined as “fatty infiltration” or “nonalcoholic fatty pancreas disease” (NAFPD). The term “fatty replacement” describes a distinct phenomenon characterized by death of acinar cells and replacement by adipose tissue. Risk factors for developing NAFPD include obesity, increasing age, male sex, hypertension, dyslipidemia, alcohol and hyperferritinemia. Increasing evidence support the role of pancreatic fat in the development of type 2 diabetes mellitus, MetS, atherosclerosis, severe acute pancreatitis and even pancreatic cancer. Evidence exists that fatty pancreas could be used as the initial indicator of “ectopic fat deposition”, which is a key element of nonalcoholic fatty liver disease and/or MetS. Moreover, in patients with fatty pancreas, pancreaticoduodenectomy is associated with an increased risk of intraoperative blood loss and post-operative pancreatic fistula.

The Influence of Bone Marrow-Secreted IL-10 in a Mouse Model of Cerulein-Induced Pancreatic Fibrosis

This study aimed to understand the role of IL-10 secreted from bone marrow (BM) in a mouse model of pancreatic fibrosis. The severity of cerulein-induced inflammation, fibrosis, and the frequency of BM-derived myofibroblasts were evaluated in the pancreas of mice receiving either a wild-type (WT) BM or an IL-10 knockout (KO) BM transplantation. The area of collagen deposition increased significantly in the 3 weeks after cerulein cessation in mice with an IL-10 KO BM transplant (13.7 ± 0.6% and 18.4 ± 1.1%, p < 0.05), but no further increase was seen in WT BM recipients over this time. The percentage of BM-derived myofibroblasts also increased in the pancreas of the IL-10 KO BM recipients after cessation of cerulein (6.7 ± 1.1% and 11.9 ± 1.3%, p < 0.05), while this figure fell in WT BM recipients after cerulein withdrawal. Furthermore, macrophages were more numerous in the IL-10 KO BM recipients than the WT BM recipients after cerulein cessation (23.2 ± 2.3 versus 15.3 ± 1.7 per HPF, p < 0.05). In conclusion, the degree of fibrosis, inflammatory cell infiltration, and the number of BM-derived myofibroblasts were significantly different between IL-10 KO BM and WT BM transplanted mice, highlighting a likely role of IL-10 in pancreatitis.

Role of leptin in body temperature regulation and lipid metabolism following splenectomy

OBJECTIVE

The physiological changes in serum triglycerides and body temperature that are induced by splenectomy are poorly understood. Therefore, the aim of this study was to investigate parameters related to lipid and glucose metabolism, as well as thermoregulation, in splenectomized mice.

DESIGN AND METHODS

Splenectomized and sham-operated WT mice (C57Bl/6) and ob/ob mice were randomly divided and treated with a standard or high fat diet, and several metabolic parameters and the body temperature were investigated.

RESULTS

Splenectomy induced a significant increase in triglyceride levels regardless of the diet. It was found that the splenectomized WT mice showed greater serum leptin and insulin levels compared with the sham-operated mice. Additionally, the body temperatures of the splenectomized WT mice were greater than the body temperatures of the control animals regardless of diet; this result too was observed without any significant change in the temperature of the splenectomized ob/ob animals.

CONCLUSION

The results suggest that splenectomy interferes with serum triglyceride metabolism and body temperature regardless of the fat content in the diet and that leptin is involved in the regulation of body temperature related to splenectomy.

Protective role of spleen-derived macrophages in lung inflammation, injury, and fibrosis induced by nitrogen mustard

Nitrogen mustard (NM) is a vesicant that causes lung injury and fibrosis, accompanied by a persistent macrophage inflammatory response. In these studies we analyzed the spleen as a source of these cells. Splenectomized (SPX) and sham control rats were treated intratracheally with NM (0.125 mg/kg) or PBS control. Macrophage responses were analyzed 1-7 days later. Splenectomy resulted in an increase in lung macrophages expressing CCR2, but a decrease in ATR-1α(+) cells, receptors important in bone marrow and spleen monocyte trafficking, respectively. Splenectomy was also associated with an increase in proinflammatory M1 (iNOS(+), CD11b(+)CD43(+)) macrophages in lungs of NM-treated rats, as well as greater upregulation of iNOS and COX-2 mRNA expression. Conversely, a decrease in CD11b(+)CD43(-) M2 macrophages was observed in SPX rats, with no changes in CD68(+), CD163(+), CD206(+), or YM-1(+) M2 macrophages, suggesting distinct origins of M2 subpopulations responding to NM. Macrophage expression of M2 genes including IL-10, ApoE, PTX-2, PTX-3, 5-HT2α, and 5-HT7 was also reduced in NM-treated SPX rats compared with shams, indicating impaired M2 activity. Changes in lung macrophages responding to NM as a consequence of splenectomy were correlated with exacerbated tissue injury and more rapid fibrogenesis. These data demonstrate that the spleen is a source of a subset of M2 macrophages with anti-inflammatory activity; moreover, in their absence, proinflammatory/cytotoxic M1 macrophages predominate in the lung, resulting in heightened pathology. Understanding the origin of macrophages and characterizing their phenotype after vesicant exposure may lead to more targeted therapeutics aimed at reducing toxicity and disease pathogenesis.

Metabolic and Phenotypic Differences between Mice Producing a Werner Syndrome Helicase Mutant Protein and Wrn Null Mice

Werner syndrome (WS) is a premature aging disorder caused by mutations in a RecQ-family DNA helicase, WRN. Mice lacking part of the helicase domain of the WRN orthologue exhibit many phenotypic features of WS, including metabolic abnormalities and a shorter mean life span. In contrast, mice lacking the entire Wrn protein (i.e. Wrn null mice) do not exhibit a premature aging phenotype. In this study, we used a targeted mass spectrometry-based metabolomic approach to identify serum metabolites that are differentially altered in young Wrn helicase mutant and Wrn null mice. An antibody-based quantification of 43 serum cytokines and markers of cardiovascular disease risk complemented this study. We found that Wrn helicase mutants exhibited elevated and decreased levels, respectively, of the anti-inflammatory cytokine IL-10 and the pro-inflammatory cytokine IL-18. Wrn helicase mutants also exhibited an increase in serum hydroxyproline and plasminogen activator inhibitor-1, markers of extracellular matrix remodeling of the vascular system and inflammation in aging. We also observed an abnormal increase in the ratio of very long chain to short chain lysophosphatidylcholines in the Wrn helicase mutants underlying a peroxisome perturbation in these mice. Remarkably, the Wrn mutant helicase protein was mislocalized to the endoplasmic reticulum and the peroxisomal fractions in liver tissues. Additional analyses with mouse embryonic fibroblasts indicated a severe defect of the autophagy flux in cells derived from Wrn helicase mutants compared to wild type and Wrn null animals. These results indicate that the deleterious effects of the helicase-deficient Wrn protein are mediated by the dysfunction of several cellular organelles.

Splenectomy attenuates obesity and decreases insulin hypersecretion in hypothalamic obese rats

OBJECTIVE

Obesity-induced abnormalities, such as insulin resistance, dyslipidemia and hypertension, are frequently correlated with low-grade inflammation, a process that may depend on normal spleen function. This study investigated the role of the spleen in the obesity induced by monosodium glutamate (MSG) treatment.

MATERIALS/METHODS

MSG-obese and lean control (CON) rats were subjected to splenectomy (SPL) or non-operated (NO).

RESULTS

MSG-NO rats presented a high adipose tissue content, insulin resistance, dyslipidemia and islet hypersecretion, accompanied by hypertrophy of both pancreatic islets and adipocytes when compared with CON-NO rats. In addition, changes in nitric oxide response were found in islets from the MSG-NO group without associated alterations in inducible nitric oxide synthase (iNOS) or IL1β expression. MSG-NO also presented increased leukocyte counts and augmented LPS-induced nitric oxide production in macrophages. Splenectomy of MSG-obese animals decreased insulin hypersecretion, normalized the nitric oxide response in the pancreatic islets, improved insulin sensitivity and reduced hypertrophy of both adipocytes and islets, when compared with MSG-NO rats.

CONCLUSION

Results show that splenectomy attenuates the progression of the obesity modulating pancreas functions in MSG-obese rats.

Severity of non-alcoholic fatty liver disease is associated with high systemic levels of tumor necrosis factor alpha and low serum interleukin 10 in morbidly obese patients

Morbid obesity has been shown to increase the risk to develop hepatic steatosis, also referred to as non-alcoholic fatty liver disease (NAFLD). Emerging evidence suggests that the severity of NAFLD may associate with increased serum levels of inflammatory markers as well as decreased concentration of mediators with anti-inflammatory actions, such as tumor necrosis factor alpha (TNF-α) and interleukin (IL) 10, respectively. We thus examined the serum levels of TNF-α and IL-10 in 102 morbidly obese women and men (body mass index > 40 kg/m(2)), exhibiting different grades of NAFLD. Blood glucose, glycated hemoglobin, insulin, the homeostatic model assessment of insulin resistance (HOMA-IR), total cholesterol, triglycerides, high- and low-density lipoproteins, parameters of liver function, TNF-α, and IL-10 were measured in each subject. The stage of NAFLD was estimated by abdominal ultrasound imaging. In comparison with morbidly obese subjects without steatosis, morbidly obese patients with NAFLD showed increased age (39.23 ± 9.80 years), HOMA-IR (6.74 ± 1.62), total cholesterol (219.7 ± 9.58 mg/dl), aspartate aminotransferase (36.25 ± 3.24 UI/l), gamma-glutamyl transpeptidase (37.12 ± 3.41 UI/l), and TNF-α (37.41 ± 1.72 pg/ml) as well as decreased serum levels of IL-10 (61.05 ± 2.43 pg/ml). Interestingly, the systemic levels of TNF-α increased, while IL-10 decreased in accordance with the severity of NAFLD, which supports a role for systemic inflammatory mediators in promoting steatosis progression. Further clinical prospective studies need to be addressed to elucidate the role of TNF-α and IL-10 in the development of NAFLD while also establishing their clinical utility in the assessment of morbidly obese patients at higher risk to develop severe steatosis.

Nonalcoholic fatty liver disease progression in rats is accelerated by splenic regulation of liver PTEN/AKT

BACKGROUND/AIM

The spleen has been reported to participate in the development of nonalcoholic fatty liver disease (NAFLD), but the mechanism has not been fully characterized. This study aims to elucidate how the spleen affects the development of NAFLD in a rat model.

MATERIALS AND METHODS

Following either splenectomy or sham operation, male Sprague-Dawley (SD) rats were fed a high-fat diet to drive the development of NAFLD; animals fed a normal diet were used as controls. Two months after surgery, livers and blood samples were collected. Serum lipids were measured; liver histology, phosphatase and tensin homologue deleted on chromosome 10 (PTEN) gene expression, and the ratio of pAkt/Akt were determined.

RESULTS

Splenectomy increased serum lipids, except triglyceride (TG) and high-density lipoprotein (HDL), in animals fed either a high-fat or normal diet. Furthermore, splenectomy significantly accelerated hepatic steatosis. Western blot analysis and real-time polymerase chain reaction showed splenectomy induced significant downregulation of PTEN expression and a high ratio of pAkt/Akt in the livers.

CONCLUSIONS

The spleen appears to play a role in the development of NAFLD, via a mechanism involving downregulation of hepatic PTEN expression.

Ectopic fat storage in the pancreas using 1H-MRS: importance of diabetic status and modulation with bariatric surgery-induced weight loss

OBJECTIVES

Recent literature suggests that ectopic fat deposition in the pancreas may contribute to endocrine and exocrine organ dysfunction, such as type 2 diabetes (T2D), pancreatitis or pancreatic cancer. The aim of this study was to determine factors associated with pancreatic triglyceride content (PTGC), and to investigate the impact of bariatric surgery on ectopic fat pads, pancreatic fat (PTGC) and hepatic fat (HTGC).

SUBJECTS

In all, 45 subjects (13 lean, 13 obese nondiabetics and 19 T2D, matched for age and gender) underwent 1H-magnetic resonance spectroscopy, computed tomography of the visceral abdominal fat, metabolic and lipidomic analysis, including insulin-resistance homeostasis model assessment (HOMA-IR), insulin-secretion homeostasis model assessment (HOMA-B) and plasma fatty-acid composition. Twenty obese subjects were reassessed 6 months after the bariatric surgery.

RESULTS

PTGC was significantly higher in type 2 diabetic subjects (23.8±3.2%) compared with obese (14.0±3.3; P=0.03) and lean subjects (7.5±0.9%; P=0.0002). PTGC remained significantly associated with T2D after adjusting for age and sex (β=0.47; P=0.004) or even after adjusting for waist circumference, triglycerides and HOMA-IR (β=0.32; P=0.04). T2D, C18:1n-9 (oleic acid), uric acid, triglycerides and plasminogen activator inhibitor-1 were the five more important parameters involved in PTGC prediction (explained 80% of PTGC variance). Bariatric surgery induced a huge reduction of both HTGC (-51.2±7.9%) and PTGC (-43.8±7.0%) reaching lean levels, whereas body mass index remained greatly elevated. An improvement of insulin resistance HOMA-IR and no change in HOMA-B were observed after bariatric surgery. The PTGC or HTGC losses were not correlated, suggesting tissue-specific mobilization of these ectopic fat stores.

CONCLUSION

Pancreatic fat increased with T2D and drastically decreased after the bariatric surgery. This suggests that decreased PTGC may contribute to improved beta cell function seen after the bariatric surgery. Further, long-term interventional studies are warranted to examine this hypothesis and to determine the degree to which ectopic fat mobilization may mediate the improvement in endocrine and exocrine pancreatic functions.

Hydrodynamic delivery of mIL10 gene protects mice from high-fat diet-induced obesity and glucose intolerance

High-fat diet (HFD) induced obesity is associated with low-grade inflammation, insulin resistance (IR), and glucose intolerance. The objective of this study is to assess the effect of interleukin 10 (IL10), an anti-inflammatory cytokine, on blocking HFD-induced obesity and obesity-associated metabolic disorders by hydrodynamic delivery of IL10-containing plasmid. Animals fed a regular chow or HFD received two injections (one on day 1 and the other on day 31) of plasmids containing green fluorescence protein (GFP) or mouse IL10 (mIL10) gene. Blood concentration of mIL10 reached ~200 ng/ml on day 7 in animals receiving mIL10 plasmid DNA. The transfection efficiency of liver cells was the same in animals fed a regular chow or HFD. No difference was seen in animals on regular chow when injected with plasmids containing either gfp or mIL10 gene. Overexpression of mIL10 prevented weight gain of animals on HFD. Intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance tests (ITT) showed that mIL10 maintained insulin sensitivity and prevented glucose intolerance. The mechanistic study reveals that mIL10 suppressed macrophage infiltration and reduced the development of crown-like structures in adipose tissue (AT). Collectively, these results suggest that maintaining a higher level of IL10 through gene transfer could be an effective strategy in preventing diet-induced obesity.