Caroline Candida de Oliveira

Attenuation of colitis injury in rats using Garcinia cambogia extract

Inflammatory bowel disease (IBD), Crohns disease and ulcerative colitis are chronic enteropathies that probably result from a dysregulated mucosal immune response. These pathologies are characterized by oxidative and nitrosative stress, leukocyte infiltration and up‐regulation of pro‐inflammatory substances. Current IBD treatment presents limitations in both efficacy and safety that stimulated the search for new active compounds. Garcinia cambogia extract has attracted interest due to its pharmacological properties, including gastroprotective effects. In this study, the antiinflammatory activity of a garcinia extract was assessed in TNBS‐induced colitis rats. The results obtained revealed that garcinia administration to colitic rats significantly improved the macroscopic damage and caused substantial reductions in increases in MPO activity, COX‐2 and iNOS expression. In addition, garcinia extract treatment was able to reduce PGE2 and IL‐1β colonic levels. These antiinflammatory actions could be related to a reduction in DNA damage in isolated colonocytes, observed with the comet assay. Finally, garcinia extract caused neither mortality nor toxicity signals after oral administration. As such, the antiinflammatory effects provided by the Garcinia cambogia extract result in an improvement of several parameters analysed in experimental colitis and could provide a source for the search for new antiinflammatory compounds useful in IBD treatment. Copyright

Inflammatory alterations in excluded colon in rats: A comparison with chemically induced colitis

Abstract Diversion colitis occurs commonly in the large bowel remnant after diversion of the fecal stream. Several experimental models of colitis have been described, but none examine the inflammatory alterations that can occur in experimentally defunctioned colons. This characterization could be useful in understanding pathophysiological aspects of diversion colitis, and in developing future therapeutic strategies. Thus, we evaluated the temporal inflammatory alterations in the defunctioned colon of rats by analyzing the histological results, infiltrating neutrophils, pro-inflammatory markers such as cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS), and DNA damage in isolated colonocytes. We compared the obtained data with those from hapten-induced colitis. The experimental diversion of the colon fecal stream induces diversion colitis characterized by an early inflammatory process with increased neutrophil infiltrate, and COX-2 and iNOS expression that resembles, in some aspects, the inflammatory characteristics of chemically induced colitis. After acute inflammation resolution, there was an increase in COX-2 and iNOS expression and the presence of lymphoid follicular hyperplasia and ulcerations, suggesting that diversion colitis can be experimentally established and useful for studying different pathophysiological aspects of this condition.

Infliximab modifies mesenteric adipose tissue alterations and intestinal inflammation in rats with TNBS-induced colitis.

Abstract Objective. Infliximab is a monoclonal anti-TNF-α antibody that is used therapeutically to treat Crohns disease (CD). High levels of pro-inflammatory cytokines, especially TNF-α, have been observed in the gastrointestinal tract of CD patients and were associated with alterations in the mesenteric adipose tissue, which also contributed to the high levels of adipokine release. The authors used a rat model of colitis that produces mesenteric adipose tissue alterations that are associated with intestinal inflammation to study the effects that infliximab treatment has on adipokine production, morphological alterations in adipose tissue and intestinal inflammation. Material and methods. The ability of infliximab to neutralize rat TNF-α was evaluated in vitro using U937 cells. Colitis was induced by repeated intracolonic trinitrobenzene sulfonic acid instillations and was evaluated by macroscopic score, histopathological analysis, myeloperoxidase activity, TNF-α and IL-10 expression as well as iNOS (inducible NO synthase) expression and JNK phosphorylation in colon samples. The alterations in adipose tissue were assessed by TNF-α, IL-10, leptin, adiponectin and resistin levels as well as adipocyte size and peroxisome proliferator-activated receptor (PPAR)-γ expression. Results. Infliximab treatment controlled intestinal inflammation, which reduced lesions and neutrophil infiltration. Inflammatory markers, such as iNOS expression and JNK phosphorylation, were also reduced. In mesenteric adipose tissue, infliximab increased the production of IL-10 and resistin, which was associated with the restoration of adipocyte morphology and PPAR-γ expression. Conclusions. Our results suggest that infliximab could contribute to the control of intestinal inflammation by modifying adipokine production by mesenteric adipose tissue.

Methotrexate is effective in reactivated colitis and reduces inflammatory alterations in mesenteric adipose tissue during intestinal inflammation.

Mesenteric white adipose tissue hypertrophy and modifications in adipocytokine production are described features of Crohns disease. Experimentally, mesenteric white adipose tissue alterations, associated with intestinal inflammation, can be induced in a model of reactivated colitis by repeated administration of intrarectal trinitrobenzenosulfonic acid (TNBS) in ethanol solution. Crohns disease patients refractory to corticosteroid treatment are frequently treated with methotrexate; however, there is no information regarding the drugs effect on adipose tissue alterations and in a reactivated colitis experimental model. Thus, we evaluated the effect of methotrexate upon mesenteric WAT alterations and inflammatory features in experimental colitis in rats. Colitis status was evaluated by macroscopic score, histopathological analysis, myeloperoxidase activity, TNF-alpha and IL-10 expression, as well as iNOS and TLR-4 expression in colon samples. The adipose tissue alterations were assessed by TNF-alpha, IL-10, leptin and adiponectin production, as well as by macrophage infiltration evaluation. Methotrexate exerts an anti-inflammatory activity in experimental reactivated colitis by regulating the shift from Th1 to Th2 cytokines, reducing TNF-alpha and improving IL-10 production. Additionally, methotrexate reduces other inflammatory parameters in the colon, such as iNOS and TLR-4 expression. In mesenteric white adipose tissue, methotrexate treatment reduces the production of pro- and anti-inflammatory adipocytokines as well as macrophage infiltration, suggesting that immunosuppressant drugs diminish adipose tissue inflammatory alterations associated with intestinal inflammation.

SOX9 Elevation Acts with Canonical WNT Signaling to Drive Gastric Cancer Progression.

Gastric cancer remains one of the leading causes of global cancer mortality due to therapy resistance, with Helicobacter pylori (H. pylori) infection being a major risk factor. In this study, we report the significance of an elevation of the stem cell regulator SOX9 in bacteria-infected human gastritis and cancer samples, paralleling increased levels of TNFα SOX9 elevation was more intense in specimens containing the pathogenically significant cagA+ strains of H. pylori Notably, we found that SOX9 was required for bacteria-induced gastric cancer cell proliferation, increased levels of β-catenin, and acquisition of stem cell-like properties. Analysis of three large clinical cohorts revealed elevated SOX9 levels in gastric cancer with advanced tumor stage and poor patient survival. Functionally, SOX9 silencing in gastric cancer cells enhanced apoptosis and senescence, concomitantly with a blockade to self-renewal and tumor-initiating capability. Paralleling these effects, we also found SOX9 to mediate cisplatin chemoresistance associated with reduced disease-free survival. Mechanistic interactions between SOX9 and β-catenin expression suggested the existence of a regulatory role for SOX9 targeting the WNT canonical pathway. Taken together, our findings establish the significance of SOX9 in gastric cancer pathobiology and heterogeneity, with implications for targeting WNT-SOX9 signaling as a rational therapeutic strategy. Cancer Res; 76(22); 6735-46. ©2016 AACR.

Perinodal Adipose Tissue and Mesenteric Lymph Node Activation During Reactivated TNBS-Colitis in Rats

BackgroundColitis induced by trinitrobenzene sulfonic acid (TNBS) with reactivation is a good experimental model for studying inflammatory bowel disease pathogenesis and appropriate therapeutics. This experimental model allows the induction of colitis relapse and remission periods and the establishment of chronic disease features, such as the mesenteric adipose tissue alterations observed in Crohn’s disease. Lymph node activation and the role of perinodal adipose tissue (PAT) have been poorly studied in this model. Thus, a study of the interactions of lymph nodes and PAT could help to elucidate the mechanisms behind IBD pathogenesis.AimsThe purpose of this study was to examine lymph nodes and PAT alterations during reactivated TNBS-colitis in Wistar rats.MethodsIn this study, the alterations of PAT and lymph node cells during experimental colitis, induced by repeated intracolonic TNBS instillations, were evaluated, focusing on fatty acid and adipocytokine profile analysis and cytokines production, respectively.Results and ConclusionFatty acid analysis of PAT reveals an increase of ω-6 polyunsaturated fatty acids during colits, such as linoleic acid, gamma-linolenic acid and arachidonic acid. ω-6 arachidonic acid was not increased in lymph node cells or serum. PAT also produces elevated levels of pro- and anti-inflammatory adipokines during colitis. Lymph node cells release high levels of IFN-γ and TNF-α but not IL-10, characterizing the predominant Th-1 response associated with this disease. Nevertheless, T cells from animals with colitis demonstrated increased IFN-γ production via a COX-2-dependent mechanism after supplementation with ω-6 arachidonic acid, suggesting that PAT modification could contribute to the lymph node cell activation observed during colitis.

Depot-specific alterations to insulin signaling in mesenteric adipose tissue during intestinal inflammatory response.

Current knowledge suggests that adipose tissue is an active organ, participating in intestinal and mesenteric disease. Additionally, adipose tissue surrounds the lymph nodes and has special properties, acting as a paracrine regulator of adjacent lymphoid tissues. These adipose tissue depots can express and secrete numerous cytokines, known as adipocytokines, which then modify the action of insulin in adipose tissue itself. Using a well-accepted model of intestinal inflammation, we studied insulin signaling in mesenteric adipose tissue (MAT) and in perinodal mesenteric adipose tissue (PAT). Our results showed that the action of insulin is modified during the intestinal inflammatory response in these adipose tissue depots. MAT became resistant to insulin signaling, as evaluated by the IRS/AKT pathway, in the inflammation. This resistant status was associated with high JNK activity and the presence of infiltrating macrophages. Conversely, the adipose tissue that involves the mesenteric lymph nodes acquired greater sensitivity to insulin signaling via IRS/AKT, probably via up-regulation of IRS during experimental colitis. We demonstrated experimentally the existence of site-specific adaptive alterations in two mesenteric adipose tissue depots to the intestinal inflammatory response, probably resulting in alterations in free fatty acids and other secretory products supplied by the adjacent tissues that could act as inflammatory modulator substances.

Thalidomide controls adipose tissue inflammation associated with high-fat diet-induced obesity in mice.

INTRODUCTION Immunosuppressant agents modulate the activity of the immune system and control adipose tissue inflammatory responses associated with obesity. Controlling adipose tissue inflammation represents an interesting option for inhibiting the low-grade inflammatory state in obese subjects and for preventing obesity-associated pathologies. In this work, we assessed the effects of thalidomide on the inflammatory response in adipose tissue as well as on systemic inflammatory marker expression in the well-established high-fat diet-induced obesity mouse model. METHODS Swiss male mice were fed a high-fat diet (60% kcal from fat) for 12 weeks and received thalidomide for the last 10 days (100 mg.kg-1). Adipokine levels were measured in serum and adipose tissue by EIA and real-time quantitative PCR, respectively. Adipose tissue infiltrating macrophages were identified by immunohistochemistry and western blot analysis of F4/80 marker expression. Other inflammatory markers, such as c-Jun N-terminal kinase (JNK) phosphorylation and monocyte chemoattractant protein-1 (MCP-1) production, were also evaluated by western blot analysis. In vitro assays using 3T3-L1 adipocytes were also conducted to evaluated adipokine release. RESULTS In obese mice, thalidomide administration induced a reduction in adiposity accompanied by a reduction of tumor necrosis factor-α (TNF-α), leptin and MCP-1 adipose tissue production, macrophage infiltration and JNK activation. TNF-α and leptin serum levels were also reduced by thalidomide treatment in obese mice. In vitro, the release of basal TNF-α and lipopolysaccharide (LPS)-induced MCP-1 was inhibited in 3T3-L1 cells. SIGNIFICANCE Our results suggest that drugs that can modulate the inflammatory status as well as control adipose tissue expansion could represent an interesting approach in the management of obesity, highlighting the need for further development of such compounds.

Effects of iron supplementation in mice with hypoferremia induced by obesity

Iron is an important micronutrient, but it can also act as a dangerous element by interfering with glucose homeostasis and inflammation, two features that are already disturbed in obese subjects. In this work, we study the effects of systemic iron supplementation on metabolic and inflammatory responses in mice with hypoferremia induced by obesity to better characterize whether iron worsens the parameters that are already altered after 24 weeks of a high-fat diet (HFD). Mice were maintained on a control diet or a HFD for 24 weeks and received iron-III polymaltose (50 mg/kg/every 2 days) during the last two weeks. Glucose homeostasis (basal glucose and insulin test tolerance) and systemic and visceral adipose tissue (VAT) inflammation were assessed. Iron levels were measured in serum. The Prussian blue reaction was used in isolated macrophages to detect iron deposition. Iron supplementation resulted in an increased number of VAT macrophages that were positive for Prussian blue staining as well as increased serum iron levels. Systemic hepcidin, leptin, resistin, and monocyte chemoattractant protein-1 (MCP-1) levels were not altered by iron supplementation. Local adipose tissue inflammation was also not made worse by iron supplementation because the levels of hepcidin, MCP-1, leptin, and interleukin (IL)-6 were not altered. In contrast, iron supplementation resulted in an increased production of IL-10 by adipose tissue and VAT macrophages. Leukocytosis and VAT plasminogen activator inhibitor-1 (PAI-1) level were reduced, but insulin resistance was not altered after iron supplementation. In conclusion, systemic iron supplementation in mice with hypoferremia induced by obesity did not worsen inflammatory marker or adipose tissue inflammation or the metabolic status established by obesity. Iron deposition was observed in adipose tissue, mainly in macrophages, suggesting that these cells have mechanisms that promote iron incorporation without increasing the production of inflammatory mediators.

A novel experimental model of erectile dysfunction in rats with heart failure using volume overload

Background Patients with heart failure (HF) display erectile dysfunction (ED). However, the pathophysiology of ED during HF remains poorly investigated. Objective This study aimed to characterize the aortocaval fistula (ACF) rat model associated with HF as a novel experimental model of ED. We have undertaken molecular and functional studies to evaluate the alterations of the nitric oxide (NO) pathway, autonomic nervous system and oxidative stress in the penis. Methods Male rats were submitted to ACF for HF induction. Intracavernosal pressure in anesthetized rats was evaluated. Concentration-response curves to contractile (phenylephrine) and relaxant agents (sodium nitroprusside; SNP), as well as to electrical field stimulation (EFS), were obtained in the cavernosal smooth muscle (CSM) strips from sham and HF rats. Protein expression of endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS) and phosphodiestarese-5 in CSM were evaluated, as well as NOX2 (gp91phox) and superoxide dismutase (SOD) mRNA expression. SOD activity and thiobarbituric acid reactive substances (TBARs) were also performed in plasma. Results HF rats display erectile dysfunction represented by decreased ICP responses compared to sham rats. The neurogenic contractile responses elicited by EFS were greater in CSM from the HF group. Likewise, phenylephrine-induced contractions were greater in CSM from HF rats. Nitrergic response induced by EFS were decreased in the cavernosal tissue, along with lower eNOS, nNOS and phosphodiestarese-5 protein expressions. An increase of NOX2 and SOD mRNA expression in CSM and plasma TBARs of HF group were detected. Plasma SOD activity was decreased in HF rats. Conclusion ED in HF rats is associated with decreased NO bioavailability in erectile tissue due to eNOS/nNOS dowregulation and NOX2 upregulation, as well as hypercontractility of the penis. This rat model of ACF could be a useful tool to evaluate the molecular alterations of ED associated with HF.