Corilagin Counteracts IL-13Rα1 Signaling Pathway in Macrophages to Mitigate Schistosome Egg-Induced Hepatic Fibrosis.

The IL-13Rα1 signaling pathway and M2 macrophages play crucial roles in schistosome egg-induced hepatic fibrosis via the expression of pro-fibrotic molecules. This study aims to investigate the inhibitory effect and mechanism of action of corilagin on schistosome egg-induced hepatic fibrosis via the IL-13Rα1 signaling pathway in M2 macrophages in vitro and in vivo. The mRNA and protein expression of IL-13Rα1, PPARγ, KLF4, SOCS1, STAT6, p-STAT6, and TGF-ß was measured in vitro with corilagin treatment after IL-13 stimulation and in vivo corilagin treatment after effectively killing the adult schistosomes in schistosome-infected mice. Histological analysis of liver tissue was assessed for the degree of hepatic fibrosis. The results revealed that corilagin significantly reduced the expression of PPARγ, KLF4, SOCS1, p-STAT6, and TGF-ß compared with model group and praziquantel administration (p < 0.01 or p < 0.05) in vivo and in vitro, which indicated a strong inhibitory effect of corilagin on IL-13Rα1 signaling pathway. As well, the inhibitory effect of corilagin showed a significant dose-dependence (p < 0.05). The area of fibrosis and distribution of M2 macrophages in mouse liver tissue were reduced significantly and dose-dependently with corilagin treatment compared to model group or praziquantel administration (p < 0.01 or p < 0.05), indicating that corilagin suppressed IL-13Rα1 signaling pathway and M2 macrophage polarization effectively in vivo. Furthermore, the anti-fibrogenic effect persisted even when IL-13Rα1 was up- or down-regulated in vitro. In conclusion, corilagin can suppress schistosome egg-induced hepatic fibrosis via inhibition of M2 macrophage polarization in the IL-13Rα1 signaling pathway.

Role of hydrogen sulfide in portal hypertension and esophagogastric junction vascular disease.

AIM: To investigate the association between endogenous hydrogen sulfide (H2S) and portal hypertension as well as its effect on vascular smooth muscle cells. METHODS: Portal hypertension patients were categorized by Child-Pugh score based on bilirubin and albumin levels, prothrombin time, ascites and hepatic encephalopathy. Plasma H2S concentrations and portal vein diameters (PVDs) were compared between portal hypertension patients and control participants, as well as between portal hypertension patients with varying degrees of severity. In addition, we established a rabbit hepatic schistosomiasis portal hypertension (SPH) model and analyzed liver morphology, fibrosis grade, plasma and liver tissue H2S concentrations, as well as cystathionine γ-lyase (CSE) activity and phosphorylated extracellular signal-regulated kinase (pERK)1/2, B cell lymphoma (Bcl)-2 and Bcl-XL expression in portal vein smooth muscle cells, in addition to their H2S-induced apoptosis rates. RESULTS: In portal hypertension patients, endogenous H2S levels were significantly lower than those in healthy controls. The more severe the disease was, the lower were the H2S plasma levels, which were inversely correlated with PVD and Child-Pugh score. Liver tissue H2S concentrations and CSE expression were significantly lower in the SPH rabbit livers compared with the control animals, starting at 3 wk, whereas pERK 1/2 expressions gradually increased 12-20 wk after SPH model establishment. In portal vein smooth muscle cells, increasing H2S levels led to increased apoptosis, while Bcl-2 and Bcl-XL expression decreased. CONCLUSION: H2S prevents vascular restructuring caused by excessive proliferation of smooth muscle cells via apoptosis induction, which helps to maintain normal vascular structures.

Dynamics of Sept4 expression in fibrotic livers of mice infected with Schistosoma japonicum.

n order to investigate the dynamics of Septin4 (Sept4) expression and its function in the formation of fibrotic livers in mice infected with Schistosoma japonicum, we constructed the mouse model of S. japonicum egg-induced liver fibrosis for 24 weeks. Immunohistochemical staining, qRT-PCR and Western blot were used to detect the expression of Sept4 and α-smooth muscle actin (α-SMA). We found Sept4 localized in the perisinusoidal space where hepatic stellate cells (HSCs) distribute in the periphery of circumoval granulomas and the portal venule. The expression of Sept4 and α-SMA had a similar significant tendency of an up-regulation to a peak at 12 weeks post-infection (p.i.) followed by a down-regulation. At 24 weeks p.i. both were at a low level. These results suggest that Sept4 and α-SMA may interact together in HSCs. Based on this evidence, we hypothesize that Sept4 seems to be involved in the formation of inflammatory granulomata and subsequent liver fibrosis by regulating HSCs activation.

Dynamics of Capillaria-hepatica-induced hepatic septal fibrosis in rats.

INTRODUCTION: The pathogenesis of septal hepatic fibrosis, induced in rats by Capillaria hepatica infection, was studied with the aid of a large collection of stored paraffin blocks, representative of the different evolutive phases of fibrosis which appeared in 100% of infected rats. METHODS: Studies were conducted involving histology, immunohistochemistry, immunofluorescence and morphometric methods, in order to observe the dynamic behavior of the cellular and matrix components of fibrosis, over a one year period of evolution. RESULTS: Observation verified that septal fibrosis originates from several portal spaces simultaneously. Its origin and progression involve blood vessel proliferation (angiogenesis), multiplication of actin-positive cells (pericytes and myofibroblasts) and progressive collagen deposition. By the end of 4-5 months, a progressive decrease in all these components was observed, when signs of regression of septal fibrosis became more evident over time. CONCLUSIONS: Besides indicating the fundamental role played by angiogenesis in the pathogenesis of fibrosis, these morphological data concerning the dynamics of this C. hepatica experimental model proved to be adequate for future investigations regarding the functional aspects of fibrosis induction, progression and regression.

Dynamics of Capillaria-hepatica-induced hepatic septal fibrosis in rats / Dinâmica da fibrose septal hepática induzida por Capillaria hepatica em ratos

INTRODUCTION: The pathogenesis of septal hepatic fibrosis, induced in rats by Capillaria hepatica infection, was studied with the aid of a large collection of stored paraffin blocks, representative of the different evolutive phases of fibrosis which appeared in 100 percent of infected rats. METHODS: Studies were conducted involving histology, immunohistochemistry, immunofluorescence and morphometric methods, in order to observe the dynamic behavior of the cellular and matrix components of fibrosis, over a one year period of evolution. RESULTS: Observation verified that septal fibrosis originates from several portal spaces simultaneously. Its origin and progression involve blood vessel proliferation (angiogenesis), multiplication of actin-positive cells (pericytes and myofibroblasts) and progressive collagen deposition. By the end of 4-5 months, a progressive decrease in all these components was observed, when signs of regression of septal fibrosis became more evident over time. CONCLUSIONS: Besides indicating the fundamental role played by angiogenesis in the pathogenesis of fibrosis, these morphological data concerning the dynamics of this C. hepatica experimental model proved to be adequate for future investigations regarding the functional aspects of fibrosis induction, progression and regression.

INTRODUÇÃO: Um extenso material de patologia experimental arquivado em blocos de parafina, ilustrativo das diferentes fases da fibrose hepática septal, que 100 por cento dos ratos desenvolvem em seguida uma infecção com o nematódeo Capillaria hepatica. MÉTODOS: O material foi sistematicamente estudado com métodos morfológicos e morfométricos, no sentido de se verificar o comportamento dos elementos celulares e matriciais durante a evolução da fibrose hepática septal ao longo de um período de um ano. RESULTADOS: Foi constatado que a fibrose septal se origina de vários espaços porta ao mesmo tempo, com proliferação vascular (angiogênese), multiplicação de células actino-positivas (pericitos, miofibroblastas) e progressivo depósito de colágeno. Ao fim dos 4-5 meses há uma involução regressiva de todos estes indícios morfológicos, mas com alguns septos persistindo bem evidentes até o fim de um ano. CONCLUSÕES: Além de ilustrar o papel fundamental desempenhado pela angiogênese, o modelo se mostrou adequado para futuros estudos funcionais relacionados com a indução, progressão e regressão da fibrose hepática.

Capillaria hepatica-induced septal fibrosis in rats: a contribution to the study of liver fibrogenesis.

INTRODUCTION: Septal fibrosis of the liver regularly develops in rats infected with the nematode Capillaria hepatica. Curative treatment of the infection prevents the development of septal fibrosis when intervention occurs up to postinfection day (PID) 15, but not later. The present investigation aimed to demonstrate which parasitic factors are present when the process of septal fibrosis can no longer be prevented by curative treatment. METHODS: Wistar rats were infected with 600 embryonated eggs of C. hepatica administered by gavage and treated with ivermectin and mebendazole in separate groups at PIDs 10, 12, 15, 17 or 20. Rats from each group and their nontreated controls, were killed and examined 40 days after the end of treatment. RESULTS: Findings by PID 15 were compatible with the stage of complete maturation of infection, when worms and eggs were fully developed and a complex host-parasite multifocal necroinflammatory reaction showed greater intensity, but with no signs of septal fibrosis, which appeared from PID 17 onward. CONCLUSIONS: Since the worms spontaneously died by PID 15, not only septal fibrosis production, but also its maintenance and further development appeared dependent on the presence of eggs, which were the only parasitic factor remaining thereafter.

Capillaria hepatica-induced septal fibrosis in rats: a contribution to the study of liver fibrogenesis / Contribuição para o estudo da fibrogenesis hepática em ratos infectados com Capillaria hepatica

INTRODUCTION: Septal fibrosis of the liver regularly develops in rats infected with the nematode Capillaria hepatica. Curative treatment of the infection prevents the development of septal fibrosis when intervention occurs up to postinfection day (PID) 15, but not later. The present investigation aimed to demonstrate which parasitic factors are present when the process of septal fibrosis can no longer be prevented by curative treatment. METHODS: Wistar rats were infected with 600 embryonated eggs of C. hepatica administered by gavage and treated with ivermectin and mebendazole in separate groups at PIDs 10, 12, 15, 17 or 20. Rats from each group and their nontreated controls, were killed and examined 40 days after the end of treatment. RESULTS: Findings by PID 15 were compatible with the stage of complete maturation of infection, when worms and eggs were fully developed and a complex host-parasite multifocal necroinflammatory reaction showed greater intensity, but with no signs of septal fibrosis, which appeared from PID 17 onward. CONCLUSIONS: Since the worms spontaneously died by PID 15, not only septal fibrosis production, but also its maintenance and further development appeared dependent on the presence of eggs, which were the only parasitic factor remaining thereafter.

INTRODUÇÃO: A fibrose septal do fígado se desenvolve regularmente em ratos infectados pelo nematódeo Capillaria hepatica. O tratamento curativo da infecção, feito antes do 15º dia da infecção, mas não mais tarde, impediu o aparecimento da fibrose septal. O presente trabalho procura verificar qual o estado do parasitismo aos 15 dias da infecção, crucial para patogenia da fibrose septal. MÉTODOS: Ratos foram infectados por via digestiva com 600 ovos embrionados de C. hepatica e tratados com Ivermectina e mebendazol, em grupos separados, aos 10, 12, 15, 17 ou 20 dias após a infecção. O animal de cada grupo e seus respectivos controles foram mortos e examinados aos 40 dias após o fim do tratamento. RESULTADOS: Os achados aos 15 dias da infecção mostraram a maturação completa da parasitose, com presença de ovos e vermes, circundados por reação necro-inflamatória, mas ainda sem fibrose septal. Daí por diante, a fibrose septal se fez presente. CONCLUSÕES: Como os vermes morrem espontaneamente após o 15º dia da infecção, não apenas a origem, mas o posterior crescimento e a manutenção da fibrose septal dependem da presença dos ovos acumulados no fígado, os quais são os únicos elementos parasitários presentes após o 15º dia da infecção por C. hepatica no rato.

Manson's schistosomiasis in the undernourished mouse: some recent findings.

This paper deals with current knowledge of the interrelationships between Schistosoma infection and malnutrition. It emphasizes the relevance of these investigations in the face of dynamic and evolving changes occurring in population diets and changes in the epidemiological patterns of schistosomiasis in endemic countries. The paper further discusses the basis for continuing the studies on this subject and the reasons why it represents a misunderstood association. This review also focuses on the cellular and humoral immune responses in the undernourished mouse model infected with Schistosoma mansoni, with updated information on the immune response in wild-type and iNOS knockout mice concerning soluble egg antigen specific antibodies and kinetics of IFN-gamma, IL-4, IL-10 and IL-13 cytokines, in the chronic phase of Manson's schistosomiasis. There is indication that schistosome-infected undernourished mice are able to develop a humoral immune response, but antibody titres are much lower than in the control animals. Cytokine production (IFN-gamma, IL-4, IL-10) is lower in the undernourished mice, but as infection progresses to the chronic phase its kinetics run an antagonistic course when compared to that of well-nourished animals. Marked variation in the secretion of IL-13 (a fibrogenic cytokine) could explain why undernourished mice do not develop liver "pipe-stem" fibrosis described in previous papers on well-nourished animals.

Relationship between serum cytokines profiles and hepatic fibrosis in schistosomiasis mansoni: an experimental study.

Forty of eighty mice (10 each group) were infected with S. mansoni cercariae and sacrificed at 3 weeks (G-A), 6 weeks (G-B), 12 weeks (G-C) and 16 weeks (G-D) post infection (P.I). The other forty mice were used as control groups of ten mice each. There were highly significant difference between egg counts after 12 weeks & 16 weeks of infection compared to 6 weeks P.I. The maximum egg count and mature eggs were in 6th week P.I while dead eggs reached the peak at 16th weeks P.I. Liver egg counts showed maximum followed by intestinal and then, stool egg counts. A highly significant differences in hydroxyproline, TGF-Bland IL-4 of infected than in controls and their peak at 16 weeks P.I. A significant difference in the IFN-gamma in the infected than in controls with peak occurred at 6 weeks P.I. and declined after that reaching a low level at 16 weeks P.I. A highly significant positive correlation was between TGF-Bland IL4 and significant negative correlation between IFN-gamma and both IL4 & TGF-B1. A highly significant and significant negative correlation between TGF-B1 and egg count at 12 & 16 weeks P.I respectively. Negative correlation was between IL-4 and egg count at 16 weeks P.I. But, significant positive correlation was between IFN-gamma with the egg count at 16 weeks P.I. A significant negative correlation was between TGF-B1 and oogram at 6 & 16 weeks P.I, but highly significant positivity was between IFN-gamma and oogram at 16 weeks P.I. A significant negative correlation was between IL-4 and oogram at 16 weeks P.I. A significant positive correlation was between levels of hydroxyproline and TGF-B1 at 12 & 16 weeks P.I. Highly significant negative correlation between hydroxyproline and IFN-gamma was at 12 weeks P.I with significant and highly significant positive correlation between hydroxyproline and IL4 at 12 & 16 weeks P.I.

Therapy with bone marrow cells reduces liver alterations in mice chronically infected by Schistosoma mansoni.

AIM: To investigate the potential of bone marrow mononuclear cells (BM-MCs) in the regeneration of hepatic lesions induced by Schistosoma mansoni (S.mansoni) chronic infection. METHODS: Female mice chronically infected with S.mansoni were treated with BM-MCs obtained from male green fluorescent protein (GFP) transgenic mice by intravenous or intralobular injections. Control mice received injections of saline in similar conditions. Enzyme-linked immunosorbent assay (ELISA) assay for transforming growth factor-beta (TGF-beta), polymerase chain reaction (PCR) for GFP DNA, immunofluorescence and morphometric studies were performed. RESULTS: Transplanted GFP(+) cells migrated to granuloma areas and reduced the percentage of liver fibrosis. The presence of donor-derived cells was confirmed by fluorescence in situ hybridization (FISH) analysis for detection of cells bearing Y chromosome and by PCR analysis for detection of GFP DNA. The levels of TGF-beta, a cytokine associated with fibrosis deposition, in liver fragments of mice submitted to therapy were reduced. The number of oval cells in liver sections of S.mansoni-infected mice increased 3-4 fold after transplantation. A partial recovery in albumin expression, which is decreased upon infection with S.mansoni, was found in livers of infected mice after cellular therapy. CONCLUSION: In conclusion, transplanted BMCs migrate to and reduce the damage of chronic fibrotic liver lesions caused by S.mansoni.

Role of partial hepatectomy on Capillaria hepatica-induced hepatic fibrosis in rats.

It is known that hepatic fibrosis may regress following partial hepatectomy, since the hepatic parenchyma regenerates very rapidly, but not the excess of fibrous tissue. The present study evaluated this hypothesis by observing the behavior of systematized septal fibrosis induced by either 30 or 90-day-old Capillaria hepatica infection, in rats subjected to partial hepatectomy. The results revealed that the morphology of the fibrosis was unaffected, but its relative quantity within the microscope field appeared significantly decreased, as a consequence of the increased liver tissue mass following regeneration.

Role of partial hepatectomy on Capillaria hepatica-induced hepatic fibrosis in rats

It is known that hepatic fibrosis may regress following partial hepatectomy, since the hepatic parenchyma regenerates very rapidly, but not the excess of fibrous tissue. The present study evaluated this hypothesis by observing the behavior of systematized septal fibrosis induced by either 30 or 90-day-old Capillaria hepatica infection, in rats subjected to partial hepatectomy. The results revealed that the morphology of the fibrosis was unaffected, but its relative quantity within the microscope field appeared significantly decreased, as a consequence of the increased liver tissue mass following regeneration.

Sabe-se que a fibrose hepática pode sofrer uma redução em seqüência uma hepatectomia parcial, uma vez que o parênquima hepático se regenera muito rápido, mas não o excesso de tecido fibroso. O presente trabalho avalia esta hipótese ao observar como se comporta a fibrose septal sistematizada induzida pela Capillaria hepática no rato, após infecção de 30 ou 90 dias de duração, em animais submetidos à hepatectomia parcial. Os resultados revelaram que a fibrose em si mesma não foi afetada na sua morfologia, mas a sua quantidade relativa apareceu diminuída significativamente no campo microscópico como conseqüência do aumento da massa de tecido hepático pós-regeneração.

Capillaria hepatica in rats: focal parasitic hepatic lesions and septal fibrosis run independent courses

Capillaria hepatica causes two main lesions in the liver of rats: multifocal chronic inflammation, directly related to the presence of disintegrating parasites and their eggs, and a process of systematized septal fibrosis. The comparative behavior of these two lesions was investigated in rats experimentally infected with 600 embryonated eggs, following either corticosteroid treatment or specific antigenic stimulation, in an attempt to understand the relationship between these two lesions, and the pathogenesis of septal fibrosis. The two treatments differently modified the morphological aspects of the focal parasitic-related lesions, but did not interfere with the presentation of diffuse septal fibrosis, although a mild decrease in the degree of fibrosis occurred in corticoid-treated animals. These findings indicate that although the two lesions are C. hepatica induced, they are under different pathogenetic control, the induction of septal fibrosis being triggered during early infection to follow an independent pathway.

Pathogenesis of septal fibrosis of the liver. (An experimental study with a new model.).

Septal fibrosis is an important, frequent, and non-specific type of fibrosis associated with chronic liver diseases, but its pathogenesis is still poorly understood. An interesting model of septal fibrosis occurs in rats infected with the nematode Capillaria hepatica. This model was used to investigate the pathogenesis, site of origin, structure, and cell-types of septal fibrosis. Forty young adult Wistar rats were inoculated with 800 embryonated eggs of C. hepatica. Daily liver samples were obtained from the 20th to the 39th day after inoculation to cover the critical period when septal fibrosis usually starts. Routine histology, electron microscopy, immunohistochemistry, and indirect immunofluorescence were applied to the study of liver sections. Septal blood vessels were demonstrated by India ink perfusion of the portal vein system. Prominent angiogenesis was observed to precede collagen deposition. Besides angiogenesis and mesenchymal-cell mobilization, septal fibrosis was seen to originate from portal spaces and to course through acinar zone I in between sinusoids, inducing no alterations in them, with no evident participation of stellate hepatic cells. Septal fibrosis appeared as an adaptative type of response of the liver to chronic injury, which resulted in a new structure that is normal to other species and creates accessory vessels that drain portal blood into hepatic sinusoids.

A contributory role for activated hepatic stellate cells in the dynamics of Schistosoma japonicum egg-induced fibrosis.

The disease manifestations of schistosomiasis arise from the mammalian host-mediated type 2 T-helper cell-induced (Th2) fibro-granulomatous inflammatory response to eggs trapped within host tissues. Activated hepatic stellate cells are well described as the effector cells of hepatic fibrosis in a variety of human diseases and rodent models. The aim of this study was to further understand the mechanism of fibrosis and the role of hepatic stellate cells in hepatic schistosomiasis progression. Groups of female CBA mice, which produce an intermediate degree of Schistosoma japonicum-induced liver fibrosis, were infected with S. japonicum, perfused at fortnightly time points and the liver tissue and contained egg granulomas examined by immunohistochemistry and cytokine and chemokine analysis using quantitative PCR. Immunohistochemistry demonstrated the presence of activated hepatic stellate cells in the periphery of egg granulomas, adjacent to fibrotic areas. Time course analysis demonstrated that the transcription of smooth muscle actin-alpha type 1 collagen, IL-4, IL-13, IL-13Ralpha2 and tissue inhibitor of metalloproteinase-1 mirrored the initial increase and subsequent down-modulation of granuloma diameter in mice. However, the transcription of monocyte chemo-attractant protein-1, Regulated upon Activation Normal T Cell Expressed and Secreted (RANTES), TNF-alpha, IFN-gamma and matrix metalloproteinase-9 paralleled the evolution of the total liver disease burden. Transforming growth factor-beta1 transcription did not appear to be of biological significance in this mouse model. Immunohistochemical analysis of human hepatic granulomas showed close association of smooth muscle actin-alpha-expressing cells with fibrosis in five available cases of end-stage (advanced) schistosomiasis japonica. We conclude that activated hepatic stellate cells play a contributory role in the granulomatous, fibrotic process induced by S. japonicum eggs, both in the murine model and in human disease.

Capillaria hepatica in rats: focal parasitic hepatic lesions and septal fibrosis run independent courses.

Capillaria hepatica causes two main lesions in the liver of rats: multifocal chronic inflammation, directly related to the presence of disintegrating parasites and their eggs, and a process of systematized septal fibrosis. The comparative behavior of these two lesions was investigated in rats experimentally infected with 600 embryonated eggs, following either corticosteroid treatment or specific antigenic stimulation, in an attempt to understand the relationship between these two lesions, and the pathogenesis of septal fibrosis. The two treatments differently modified the morphological aspects of the focal parasitic-related lesions, but did not interfere with the presentation of diffuse septal fibrosis, although a mild decrease in the degree of fibrosis occurred in corticoid-treated animals. These findings indicate that although the two lesions are C. hepatica induced, they are under different pathogenetic control, the induction of septal fibrosis being triggered during early infection to follow an independent pathway.

Regressão da fibrose hepática / Regression of hepatic fibrosis

Durante muito tempo, se acreditou que a fibrose hepática extensa e de longa duracão fosse um processo irreversível. As investigacões sobre o comportamento da fibrose hepática, nas formas avancadas da esquistossomose, vieram abalar este conceito e hoje em dia está se estabelecendo a nocão de que qualquer fibrose é reversível, inclusive aquela associada à cirrose hepática. O problema é identificar sua causa e removê-la. Embora, a fibrose hepática tenha per se pouca significacão fisiopatológica, sua gravidade está relacionada com as alteracões vasculares que ela encerra. O que dá ao assunto primordial importância são os indícios até aqui obtidos de que, a regressão da fibrose costuma se acompanhar de uma remodelacão das alteracões vasculares no seu interior. Mas, há peculiaridades relativas ao tipo anatômico e ao papel fisiológico que certas fibroses exibem, e tais peculiaridades podem interferir com o processo regressivo da mesma, o que pode significar que por vezes a fibrose pode se tornar permanente. Esses assuntos, alguns deles controversos, são aqui apresentados e discutidos.

[Regression of hepatic fibrosis]. / Regressão da fibrose hepática.

Extensive and persistent hepatic fibrosis has for a long time been considered irreversible. However, recent studies on the behavior of hepatic fibrosis, especially those related to evolution and involution of advanced schistosomiasis in man, have challenged this concept, and nowadays it is becoming clear that any type of fibrosis is reversible, including that associated with hepatic cirrhosis. The problem consists in identifying and eliminating its cause. Although fibrosis in the liver has little functional significance by itself, its severity derives from associated vascular changes. However, new data on fibrosis regression indicate that disappearance of fibrosis is usually accompanied by remodeling of vascular changes. But, there are peculiarities related to the anatomic type of fibrosis and to its functional significance, which suggest that sometimes fibrosis may indeed be irreversible. These aspects, some of which in need of further studies, are presented and discussed herein.