Eosinophils participate in modulation of liver immune response and tissue damage induced by Schistosoma mansoni infection in mice.

The severity of chronic schistosomiasis has been mainly associated with the intensity and extension of the inflammatory response induced by egg-secreted antigens in the host tissue, especially in the liver and intestine. During acute schistosomiasis, eosinophils account for approximately 50% of the cells that compose the liver granulomas; however, the role of this cell-type in the pathology of schistosomiasis remains controversial. In the current study, we compared the parasite burden and liver immunopathological changes during experimental schistosomiasis in wild-type (WT) BALB/c mice and BALB/c mice selectively deficient for the differentiation of eosinophils (ΔdblGATA). Our data demonstrated that the absence of eosinophil differentiation did not alter the S. mansoni load or the liver retention of parasite eggs; however, there were significant changes in the liver immune response profile and tissue damage. S. mansoni infection in ΔdblGATA mice resulted in significantly lower liver concentrations of IL-5, IL-13, IL-33, IL-17, IL-10, and TGF-ß and higher concentrations of IFN-γ and TNF-α, as compared to WT mice. The changes in liver immune response observed in infected ΔdblGATA mice were accompanied by lower collagen deposition, but higher liver damage and larger granulomas. Moreover, the absence of eosinophils resulted in a higher mortality rate in mice infected with a high parasite load. Therefore, the data indicated that eosinophils participate in the establishment and/or amplification of liver Th-2 and regulatory response induced by S. mansoni, which is necessary for the balance between liver damage and fibrosis, which in turn is essential for modulating disease severity.

Disodium cromoglycate treatment reduces TH2 immune response and immunohistopathological features in a murine model of Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is an emergent chronic disease of the esophagus. The immunopathological process in EoE is characterized by Th2 immune response and prominent eosinophilic influx, in response to common food allergens. The classical treatment consists of allergen elimination diet and systemic/topical corticosteroid therapy. Nevertheless, patients do not always comply to treatment, and the prolonged corticosteroid therapy can cause side effects, therefore, there is an immediate need for new therapeutic approach for EoE. Disodium cromoglicate (DSCG) is a substance broadly used in allergic asthma treatment, and a well-known mast cell activation stabilizer. However, its effect in EoE have not been evaluated yet. This study aimed to assess the effects of DSCG treatment in an EoE experimental model. Male Balb/C mice were subcutaneously sensitized for five days with OVA, and subsequently orally OVA-challenged, DSCG administration was performed between the OVA-challenges. DSCG treatment not only reduced eosinophilic and mast cell influx, as well as reduced fibrosis. In addition, tslp, GATA3, IL-5, FoxP3 and IL-10 mRNA expression were reduced in esophageal mucosa, associated with lower Th2 (CD3+CD4+GATA3+IL4+) and B cells (CD19+CD40+) number in peripheral lymphoid organs. In conclusion, the data demonstrate DSCG treatment was effective in reducing mast cell activation and Th2 immune response, important immunopathological EoE features. Therefore, the use of DSCG as an EoE treatment can be considered a promising therapeutic approach to treat this disease.

Hepatic stellate cell activation promotes alcohol-induced steatohepatitis through Igfbp3 and SerpinA12.

BACKGROUND & AIMS: Steatohepatitis drives fibrogenesis in alcohol-related liver disease. Recent studies have suggested that hepatic stellate cells (HSCs) may regulate the parenchymal cell injury and inflammation that precedes liver fibrosis, although the mechanism remains incompletely defined. Neuropilin-1 (NRP-1) and synectin are membrane proteins implicated in HSC activation. In this study, we disrupted NRP-1 and synectin as models to evaluate the role of HSC activation on the development of steatohepatitis in response to alcohol feeding in mice. METHODS: Mice with HSC-selective deletion of NRP (ColCre/Nrp1loxP) or synectin (ColCre/synectinloxP) vs. paired Nrp1loxP or synectinloxP mice were fed a control diet or the chronic/binge alcohol feeding model. Several markers of steatosis and inflammation were evaluated. RESULTS: ColCre/Nrp1loxP mice showed less fibrosis, as expected, but also less inflammation and steatosis, with lower hepatic triglyceride content. Similar results were observed in the synectin model. Hepatocytes treated with supernatant of HSCs from ColCre/Nrp1loxP mice compared to supernatant from Nrp1loxP mice were protected against ethanol-induced lipid droplet formation. An adipokine and inflammatory protein array from the supernatant of HSCs with NRP-1 knockdown showed a significant reduction in Igfbp3 (a major insulin-like growth factor-binding protein with multiple metabolic functions) and an increase in SerpinA12 (a serine-protease inhibitor) secretion compared to wild-type HSCs. Recombinant Igfbp3 induced lipid droplets, triglyceride accumulation, and lipogenic genes in hepatocytes in vitro, while SerpinA12 was protective against ethanol-induced steatosis. Finally, Igfbp3 was increased, and SerpinA12 was decreased in serum and liver tissue from patients with alcoholic hepatitis. CONCLUSION: Selective deletion of NRP-1 from HSCs attenuates alcohol-induced steatohepatitis through regulation of Igfbp3 and SerpinA12 signaling. LAY SUMMARY: Hepatic stellate cells are known for their role in fibrosis (scarring of the liver). In this study, we describe their role in the modulation of fat deposition and inflammation in the liver, which occurs secondary to alcohol damage.

Proposition of a novel animal model of systemic sclerosis induced by type V collagen in C57BL/6 mice that reproduces fibrosis, vasculopathy and autoimmunity.

BACKGROUND: Type V collagen (Col V) has the potential to become an autoantigen and has been associated with the pathogenesis of systemic sclerosis (SSc). We characterized serological, functional, and histopathological features of the skin and lung in a novel SSc murine model induced by Col V immunization. METHODS: Female C57BL/6 mice (n = 19, IMU-COLV) were subcutaneously immunized with two doses of Col V (125 µg) emulsified in complete Freund adjuvant, followed by two intramuscular boosters. The control group (n = 19) did not receive Col V. After 120 days, we examined the respiratory mechanics, serum autoantibodies, and vascular manifestations of the mice. The skin and lung inflammatory processes and the collagen gene/protein expressions were analyzed. RESULTS: Vascular manifestations were characterized by endothelial cell activity and apoptosis, as shown by the increased expression of VEGF, endothelin-1, and caspase-3 in endothelial cells. The IMU-COLV mice presented with increased tissue elastance and a nonspecific interstitial pneumonia (NSIP) histologic pattern in the lung, combined with the thickening of the small and medium intrapulmonary arteries, increased Col V fibers, and increased COL1A1, COL1A2, COL3A1, COL5A1, and COL5A2 gene expression. The skin of the IMU-COLV mice showed thickness, epidermal rectification, decreased papillary dermis, atrophied appendages, and increased collagen, COL5A1, and COL5A2 gene expression. Anti-collagen III and IV and ANA antibodies were detected in the sera of the IMU-COLV mice. CONCLUSION: We demonstrated that cutaneous, vascular, and pulmonary remodeling are mimicked in the Col V-induced SSc mouse model, which thus represents a suitable preclinical model to study the mechanisms and therapeutic approaches for SSc.

Brucella abortus Infection Elicited Hepatic Stellate Cell-Mediated Fibrosis Through Inflammasome-Dependent IL-1ß Production.

In human brucellosis, the liver is frequently affected. Brucella abortus triggers a profibrotic response on hepatic stellate cells (HSCs) characterized by inhibition of MMP-9 with concomitant collagen deposition and TGF-ß1 secretion through type 4 secretion system (T4SS). Taking into account that it has been reported that the inflammasome is necessary to induce a fibrotic phenotype in HSC, we hypothesized that Brucella infection might create a microenvironment that would promote inflammasome activation with concomitant profibrogenic phenotype in HSCs. B. abortus infection induces IL-1ß secretion in HSCs in a T4SS-dependent manner. The expression of caspase-1 (Casp-1), absent in melanoma 2 (AIM2), Nod-like receptor (NLR) containing a pyrin domain 3 (NLRP3), and apoptosis-associated speck-like protein containing a CARD (ASC) was increased in B. abortus-infected HSC. When infection experiments were performed in the presence of glyburide, a compound that inhibits NLRP3 inflammasome, or A151, a specific AIM2 inhibitor, the secretion of IL-1ß was significantly inhibited with respect to uninfected controls. The role of inflammasome activation in the induction of a fibrogenic phenotype in HSCs was determined by performing B. abortus infection experiments in the presence of the inhibitors Ac-YVAD-cmk and glyburide. Both inhibitors were able to reverse the effect of B. abortus infection on the fibrotic phenotype in HSCs. Finally, the role of inflammasome in fibrosis was corroborated in vivo by the reduction of fibrotic patches in liver from B. abortus-infected ASC, NLRP, AIM2, and cCasp-1/11 knock-out (KO) mice with respect to infected wild-type mice.

Inflammation is regulated by the adenosine derivative molecule, IFC-305, during reversion of cirrhosis in a CCl4 rat model.

Cirrhosis is a liver pathology originated by hepatocytes, Kupffer and hepatic stellate cells interactions and transformations. This pathology is associated with inflammation and fibrosis, originated by molecular signals secreted by immunological and parenchymal cells, such as cytokines and chemokines, like IL-1ß, IL-6, TNF-α or MCP-1, driven by Kupffer cells signals. As part of inflammation resolution, the same activated Kupffer cells contribute to anti-inflammatory effects with IL-10 and MMP-9 secretion. In a Wistar rat model, cirrhosis induced with CCl4 is characterized by increased inflammatory cytokines, IL-6, IL-1ß, MCP-1, and TNF-α, in plasma and liver tissue. The IFC-305 compound, an adenosine derivative salt, reverses the cirrhosis in this model, suggesting that immune mechanisms related to inflammation should be explored. The IFC-305 reduced inflammatory cytokines, supporting the anti-inflammatory effects induced by the elevation of IL-10, as well as the reduction of M1 inflammatory macrophages (CD11b/c+/CD163+) and the increase of M2 anti-inflammatory macrophages (HIS36+/CD11b+), measured by flow cytometry. Furthermore, the IFC-305 enhances the metabolic activity of arginase and moderates the inducible nitric oxide synthetase, evaluated through biochemical and immunohistochemical methods. These results contribute to understand the function of the IFC-305, which modulates the immune response in the Wistar rat model of CCl4-induced cirrhosis and support the hepatic protective action through an anti-inflammatory effect, mainly mediated by Kupffer cells.

Galectin-3: A Friend but Not a Foe during Trypanosoma cruzi Experimental Infection.

Trypanosoma cruzi interacts with host cells, including cardiomyocytes, and induces the production of cytokines, chemokines, metalloproteinases, and glycan-binding proteins. Among the glycan-binding proteins is Galectin-3 (Gal-3), which is upregulated after T. cruzi infection. Gal-3 is a member of the lectin family with affinity for ß-galactose containing molecules; it can be found in both the nucleus and the cytoplasm and can be either membrane-associated or secreted. This lectin is involved in several immunoregulatory and parasite infection process. Here, we explored the consequences of Gal-3 deficiency during acute and chronic T. cruzi experimental infection. Our results demonstrated that lack of Gal-3 enhanced in vitro replication of intracellular parasites, increased in vivo systemic parasitaemia, and reduced leukocyte recruitment. Moreover, we observed decreased secretion of pro-inflammatory cytokines in spleen and heart of infected Gal-3 knockout mice. Lack of Gal-3 also led to elevated mast cell recruitment and fibrosis of heart tissue. In conclusion, galectin-3 expression plays a pivotal role in controlling T. cruzi infection, preventing heart damage and fibrosis.

Endothelial-to-mesenchymal transition: Cytokine-mediated pathways that determine endothelial fibrosis under inflammatory conditions.

During the last decade, the endothelial-to-mesenchymal transition (EndMT) process has attracted considerable attention due to associations with the onset of certain diseases, such as organ fibrosis and cancer. Several studies have assessed the mechanisms and signaling pathways that regulate endothelial fibrosis in the context of human pathologies. A number of inflammatory mediators, including pro-inflammatory cytokines, growth factors, oxidative stress, and toxins, induce the conversion of endothelial cells into mesenchymal fibroblast-like cells that promote disease progression. This review is separated into five chapters that critically present current knowledge on EndMT in the context of pathology. First, the main characteristics of EndMT are summarized, with a focus on the endothelial protein pattern changes that modulate the expressions of endothelial/fibrotic markers and extracellular matrix proteins. These expressions could serve as mechanisms for explaining potential EndMT contributions to human pathologies in adults. Second, the main findings supporting a connection between EndMT-mediated endothelial fibrosis and inflammatory conditions are presented. These connections could be linked to the onset and progression of pathological conditions. Third, EndMT inducers are described in detail. This includes considerations on the actions of the first and most well-known EndMT inducer, TGF-ß; of the most prominent pro-inflammatory cytokines released during inflammation, such as IL 1-ß and TNF-α; and of the NF-κB transcription factor, a common player during inflammation-induced EndMT. Furthermore, thorough attention is given to EndMT induction by endotoxins in the context of bacterial infectious diseases. Additionally, the participation of the inflammatory oxidative stress environment in the EndMT induction was also reviewed. Fourth, the pathophysiological findings of inflammation-induced EndMT are presented, and, fifth, special focus is placed on associations with cancer onset and development. Altogether, this review highlights the important role of EndMT-mediated endothelial fibrosis during inflammation in human pathologies.

Anti-Cyclic Citrullinated Peptide Antibodies and Severity of Interstitial Lung Disease in Women with Rheumatoid Arthritis.

OBJECTIVE: To evaluate whether serum titers of second-generation anticyclic citrullinated peptide antibodies (anti-CCP2) are associated with the severity and extent of interstitial lung disease in rheumatoid arthritis (RA-ILD). METHODS: In across-sectional study, 39 RA-ILD patients confirmed by high-resolution computed tomography (HRCT) were compared with 42 RA without lung involvement (RA only). Characteristics related to RA-ILD were assessed in all of the patients and serum anti-CCP2 titers quantified. RESULTS: Higher anti-CCP2 titers were found in RA-ILD compared with RA only (medians 77.9 versus 30.2 U/mL, P < 0.001). In the logistic regression analysis after adjustment for age, disease duration (DD), smoke exposure, disease activity, functioning, erythrocyte sedimentation rate, and methotrexate (MTX) treatment duration, the characteristics associated with RA-ILD were higher anti-CCP2 titers (P = 0.003) and + RF (P = 0.002). In multivariate linear regression, the variables associated with severity of ground-glass score were anti-CCP2 titers (P = 0.02) and with fibrosis score DD (P = 0.01), anti-CCP2 titers (P < 0.001), and MTX treatment duration (P < 0.001). CONCLUSIONS: Anti-CCP2 antibodies are markers of severity and extent of RA-ILD in HRCT. Further longitudinal studies are required to identify if higher anti-CCP2 titers are associated with worst prognosis in RA-ILD.

The TcI and TcII Trypanosoma cruzi experimental infections induce distinct immune responses and cardiac fibrosis in dogs

Trypanosoma cruzi infection may be caused by different strains with distinct discrete typing units (DTUs) that can result in variable clinical forms of chronic Chagas disease. The present study evaluates the immune response and cardiac lesions in dogs experimentally infected with different T. cruzi strains with distinct DTUs, namely, the Colombian (Col) and Y strains of TcI and TcII DTU, respectively. During infection with the Col strain, increased levels of alanine aminotransferase, erythrocytes, haematocrit and haemoglobin were observed. In addition, CD8+ T-lymphocytes isolated from the peripheral blood produced higher levels of interleukin (IL)-4. The latter suggests that during the acute phase, infection with the Col strain may remain unnoticed by circulating mononuclear cells. In the chronic phase, a significant increase in the number of inflammatory cells was detected in the right atrium. Conversely, infection with the Y strain led to leucopoenia, thrombopoenia, inversion of the ratio of CD4+/CD8+ T-lymphocytes and alterations in monocyte number. The Y strain stimulated the production of interferon-γ by CD4+ and CD8+ T-lymphocytes and IL-4 by CD8+ T-cells. In the chronic phase, significant heart inflammation and fibrosis were observed, demonstrating that strains of different DTUs interact differently with the host.

The TcI and TcII Trypanosoma cruzi experimental infections induce distinct immune responses and cardiac fibrosis in dogs.

Trypanosoma cruzi infection may be caused by different strains with distinct discrete typing units (DTUs) that can result in variable clinical forms of chronic Chagas disease. The present study evaluates the immune response and cardiac lesions in dogs experimentally infected with different T. cruzi strains with distinct DTUs, namely, the Colombian (Col) and Y strains of TcI and TcII DTU, respectively. During infection with the Col strain, increased levels of alanine aminotransferase, erythrocytes, haematocrit and haemoglobin were observed. In addition, CD8+ T-lymphocytes isolated from the peripheral blood produced higher levels of interleukin (IL)-4. The latter suggests that during the acute phase, infection with the Col strain may remain unnoticed by circulating mononuclear cells. In the chronic phase, a significant increase in the number of inflammatory cells was detected in the right atrium. Conversely, infection with the Y strain led to leucopoenia, thrombopoenia, inversion of the ratio of CD4+/CD8+ T-lymphocytes and alterations in monocyte number. The Y strain stimulated the production of interferon-γ by CD4+ and CD8+ T-lymphocytes and IL-4 by CD8+ T-cells. In the chronic phase, significant heart inflammation and fibrosis were observed, demonstrating that strains of different DTUs interact differently with the host.

Alterações iniciais da fibrose septal por Capillaria Hepatica (Bancroft, 1893) em ratos / Initial changes of septal fibrosis Capillaria hepatica (Bancroft, 1893) in rats

espaço-porta é o local de origem da fibrose em muitas doenças crônicas hepáticas. Essa área do fígado participa da drenagem linfática hepática e abriga diversos elementos celulares potencialmente fibrogênicos. Estudos sobre a fibrose hepática relacionados à infecção experimental de ratos pelo helminto Capillaria hepatica têm demonstrado que a fibrose começa em áreas portais com a distribuição de septos que sulcam o parênquima hepático se desenvolvendo em áreas próximas ao espaço de Disse. Entretanto, apesar de esta fibrose ocorrer de forma paralela aos sinusóides, estudos têm revelado que não apenas as células estreladas hepáticas participam da fibrose septal, mas também outros tipos celulares residentes nos espaços-porta. Diante destes aspectos, o presente estudo desenvolveu-se com o intuito de investigar a contribuição das células potencialmente fibrogênicas dos espaços-porta, nas fases iniciais da infecção, onde a fibrose se concentra. Para isso, foram utilizados fragmentos de fígado, em blocos parafinados, disponíveis nos arquivos do Laboratório de Patologia Experimental (CPqGM/Fiocruz) provenientes de ratos infectados com 800 ovos de Capillaria hepatica e foi possível observar que ocorreu a proliferação de colangiócitos e a concentração de miofibroblastos em áreas portais, além da ativação de células estreladas hepáticas, sendo todos os resultados vistos por meio da coloração de rotina HE, Picro-sírius vermelho e imunohistoquímica para α-actina de músculo liso, CD31 e GFAP.

Portal space is the local of origin for fibrosis in many chronic liver diseases. This area is involved with lymph drainage and contains several cell types, potentially fibrogenic. Experimental studies related to hepatic fibrosis during Capillaria hepatica infection in rats have suggested that the septal fibrosis indeed takes origin from portal spaces, with the distribution of the septs in the parenchymal region in proximity areas of Disse space. However, despite this fibrosis occurs in parallel to sinusoids, studies have revealed that not only the hepatic stellate cells participate in septal fibrosis, but also other resident cell types in the portal spaces. In face these aspects, the goal of present study was investigate the contribution of the cells potentially fibrogenic in the portal space, in the early phases of the infection. For this, blocks in paraffin available of the liver of rats infected with 800 eggs of Capillaria hepatica archived in the Laboratory of Experimental Pathology (Research Center Gonçalo Moniz, Fiocruz - BA), were utilized and it was observed that proliferation of colangiocytes and concentration of myofibroblasts occurred portal areas, in addition to the activation of hepatic stellate cells. All results were analised by routine staining HE, Sirius red and immunohistochemistry for α-SMA, GFAP and CD31.

IgG4-related multiorgan disease: report of the first autopsy case.

IgG4-related disease (IgG4RD) is a chronic recurring fibro-inflammatory pathology that is considered to be of autoimmune origin. Histopathology is considered to be the gold standard method for diagnosis. IgG4RD affects multiple organs. IgG4RD was first identified in the pancreas and was called autoimmune pancreatitis (AIP). During the following years, the disease spectrum was expanded and it was realised that the extrapancreatic lesions can precede, coexist or appear after the diagnosis of AIP. At present, several illnesses such as Mikulicz disease, Küttner tumour, multifocal fibrosclerosis, etc, are considered to be part of the IgG4RD spectrum. The symptoms of the disease tend to appear over months and years and diagnosis is achieved on average 13.5 months (4-60 months) after the onset. The purpose of this report was to provide information about a case that was sadly fatal but that permitted a complete histopathological study of the damaged tissues.

Therapeutic DNA vaccine reduces schistosoma mansoni-induced tissue damage through cytokine balance and decreased migration of myofibroblasts.

Helminths are known to elicit a wide range of immunomodulation characterized by dominant Th2-type immune responses. Our group previously showed that a DNA vaccine encoding the mycobacterial 65-kDa heat shock protein (DNA-hsp65) showed immunomodulatory properties. We also showed, using a helminth-tuberculosis (TB) co-infection model, that the DNA-hsp65 vaccine protected mice against TB. We next investigated the mechanistic role of the vaccine during helminth-TB co-infection. Clinically, helminth infection causes type 2 granulomas in the lung. Mice were immunized with DNA-hsp65 while they were submitted to the type 2 granuloma induction protocol by Schistosoma mansoni eggs infusion. In this work we investigated the effects of DNA-hsp65 on the pathology and immune response during the development of type 2 granuloma induced by S. mansoni eggs. Histologic analyses of lung parenchyma showed that the DNA-hsp65 vaccine protected mice against exacerbated fibrosis induced by Schistosoma eggs, and decreased the size of the granulomas. These changes were correlated with a reduction in the number of T cells specific for the egg antigens in the lung and also with modulation of Th2 cytokine expression. Taken together, our results showed that the adjuvant properties of the DNA-hsp65 vaccine regulated the immune response in this Th2 model, and resulted in a preserved lung parenchyma.

Gene expression changes associated with myocarditis and fibrosis in hearts of mice with chronic chagasic cardiomyopathy.

Chronic chagasic cardiomyopathy is a leading cause of heart failure in Latin American countries. About 30% of Trypanosoma cruzi-infected individuals develop this severe symptomatic form of the disease, characterized by intense inflammatory response accompanied by fibrosis in the heart. We performed an extensive microarray analysis of hearts from a mouse model of this disease and identified significant alterations in expression of approximately 12% of the sampled genes. Extensive up-regulations were associated with immune-inflammatory responses (chemokines, adhesion molecules, cathepsins, and major histocompatibility complex molecules) and fibrosis (extracellular matrix components, lysyl oxidase, and tissue inhibitor of metalloproteinase 1). Our results indicate potentially relevant factors involved in the pathogenesis of the disease that may provide new therapeutic targets in chronic Chagas disease.

Mesenchymal stem cells attenuate renal fibrosis through immune modulation and remodeling properties in a rat remnant kidney model.

Mesenchymal stem cells (MSCs) have regenerative properties in acute kidney injury, but their role in chronic kidney diseases is still unknown. More specifically, it is not known whether MSCs halt fibrosis. The purpose of this work was to investigate the role of MSCs in fibrogenesis using a model of chronic renal failure. MSCs were obtained from the tibias and femurs of male Wistar-EPM rats. Female Wistar rats were subjected to the remnant model, and 2|x|10(5) MSCs were intravenously administrated to each rat every other week for 8 weeks or only once and followed for 12 weeks. SRY gene expression was observed in female rats treated with male MSCs, and immune localization of CD73(+)CD90(+) cells at 8 weeks was also assessed. Serum and urine analyses showed an amelioration of functional parameters in MSC-treated animals at 8 weeks, but not at 12 weeks. Masson's trichrome and Sirius red staining demonstrated reduced levels of fibrosis in MSC-treated animals. These results were corroborated by reduced vimentin, type I collagen, transforming growth factor beta, fibroblast specific protein 1 (FSP-1), monocyte chemoattractant protein 1, and Smad3 mRNA expression and alpha smooth muscle actin and FSP-1 protein expression. Renal interleukin (IL)-6 and tumor necrosis factor alpha mRNA expression levels were significantly decreased after MSC treatment, whereas IL-4 and IL-10 expression levels were increased. All serum cytokine expression levels were decreased in MSC-treated animals. Taken together, these results suggested that MSC therapy can indeed modulate the inflammatory response that follows the initial phase of a chronic renal injury. The immunosuppressive and remodeling properties of MSCs may be involved in the decreased fibrosis in the kidney.

Development of chronic cardiomyopathy in canine Chagas disease correlates with high IFN-gamma, TNF-alpha, and low IL-10 production during the acute infection phase.

When infected with Trypanosoma cruzi, Beagle dogs develop symptoms similar to those of Chagas disease in human beings, and could be an important experimental model for a better understanding of the immunopathogenic mechanisms involved in chronic chagasic infection. This study evaluates IL-10, IFN-gamma and TNF-alpha production in the sera, culture supernatant, heart and cervical lymph nodes and their correlation with cardiomegaly, cardiac inflammation and fibrosis in Beagle dogs infected with T. cruzi. Pathological analysis showed severe splenomegaly, lymphadenopathy and myocarditis in all infected dogs during the acute phase of the disease, with cardiomegaly, inflammation and fibrosis observed in 83% of the animals infected by T. cruzi during the chronic phase. The data indicate that infected animals producing IL-10 in the heart during the chronic phase and showing high IL-10 production in the culture supernatant and serum during the acute phase had lower cardiac alterations (myocarditis, fibrosis and cardiomegaly) than those with high IFN-gamma and TNF-alpha levels. These animals produced low IL-10 levels in the culture supernatant and serum during the acute phase and did not produce IL-10 in the heart during the chronic phase of the disease. Our findings showed that Beagle dogs are a good model for studying the immunopathogenic mechanism of Chagas disease, since they reproduce the clinical and immunological findings described in chagasic patients. The data suggest that the development of the chronic cardiac form of the disease is related to a strong Th1 response during the acute phase of the disease, while the development of the indeterminate form results from a blend of Th1 and Th2 responses soon after infection, suggesting that the acute phase immune response is important for the genesis of chronic cardiac lesions.

Cilostazol and pentoxifylline decrease angiogenesis, inflammation, and fibrosis in sponge-induced intraperitoneal adhesion in mice.

AIMS: Adhesion formation following abdominal intervention is an abnormal peritoneal healing process. Our aim was to investigate the effects of controlling adhesion development by inhibiting its key components (angiogenesis, inflammation and fibrosis) using phosphodiesterase (PDE) inhibitors. MAIN METHODS: Two PDE inhibitors including cilostazol a PDE3 inhibitor (40 and 400 mg/kg), and pentoxifylline (PTX), a PDE 1-5 inhibitor (50 and 500 mg/kg) were used for a period of 7 days to inhibit angiogenesis, inflammation, and fibrosis in a murine model of sponge-induced peritoneal adhesion. Angiogenesis was assessed by hemoglobin content, vascular endothelial growth factor (VEGF) levels, and morphometric analysis. Accumulation of neutrophils and macrophages was determined by measuring myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) activities, respectively. Levels of TNF-alpha were also determined. Fibrosis was assessed by determining the amount of collagen in the implant; TGF-beta1 levels in the implant were also measured. KEY FINDINGS: Our results show that the treatments attenuated the main components of the adhesion tissue by reducing the amount of fibrovascular tissue that infiltrated the sponge matrix (wet weight). Hemoglobin content and VEGF levels were also decreased by approximately 40%. Neutrophil accumulation was unaffected by the compounds. However, NAG activity was reduced by pentoxifylline, but not by cilostazol. These compounds also decreased the levels of the pro-inflammatory and pro-fibrogenic cytokines TNF-alpha and TGF-beta1, respectively, and collagen synthesis. SIGNIFICANCE: Our results suggest that cilostazol and PTX decreased the development of peritoneal adhesions in the model, which might be associated with cyclic nucleotide modulation. Therapies to intervene in these pathways may be beneficial for the prevention of these lesions.

Ventricular expression of atrial natriuretic peptide in chronic chagasic cardiomyopathy is not induced by myocarditis.

BACKGROUND: The ventricles of the normal heart are virtually devoid of atrial natriuretic peptide (ANP). Although ANP occurs in ventricles submitted to elevated wall stress, it is not clear whether ANP expression is affected by myocarditis. We investigated the immunohistochemical expression of ANP in chronic chagasic cardiomyopathy, an inflammatory cardiomyopathy caused by infection with the protozoan Trypanosoma cruzi. METHODS: Necropsy samples from the left and right ventricles of 16 patients exhibiting chronic chagasic cardiomyopathy were evaluated for myocarditis, fibrosis, T. cruzi parasites and ANP immunoreactivity. The diameters of 50 myocytes per sample were measured. RESULTS: ANP was present in myocytes of the subendocardial region in 13/16 (81.3%) left and 10/16 (62.5%) right ventricular samples (P=0.25). Myocytes present in the inflammatory foci, near the infiltrating inflammatory cells but distant from the subendocardial region, did not express ANP. Trypanosoma cruzi parasites exhibited intense immunoreactivity for ANP. The mean myocyte diameter and the incidence of myocarditis, fibrosis, and T. cruzi parasites was similar between the left and right ventricular samples. No statistical differences were found between the ANP-positive and ANP-negative cases. CONCLUSIONS: In chronic chagasic cardiomyopathy, both ventricles exhibit hypertrophy, fibrosis and ANP in the subendocardial region. The inflammatory infiltrate does not induce ANP expression in the myocytes. Regional stress but not myocarditis itself, is probably responsible for ventricular ANP expression in myocarditis.