Gut microbiota controls the development of chronic pancreatitis: A critical role of short-chain fatty acids-producing Gram-positive bacteria

Chronic pancreatitis (CP) is a progressive and irreversible fibroinflammatory disorder, accompanied by pancreatic exocrine insufficiency and dysregulated gut microbiota. Recently, accumulating evidence has supported a correlation between gut dysbiosis and CP development. However, whether gut microbiota dysbiosis contributes to CP pathogenesis remains unclear. Herein, an experimental CP was induced by repeated high-dose caerulein injections. The broad-spectrum antibiotics (ABX) and ABX targeting Gram-positive (G+) or Gram-negative bacteria (G-) were applied to explore the specific roles of these bacteria. Gut dysbiosis was observed in both mice and in CP patients, which was accompanied by a sharply reduced abundance for short-chain fatty acids (SCFAs)-producers, especially G+ bacteria. Broad-spectrum ABX exacerbated the severity of CP, as evidenced by aggravated pancreatic fibrosis and gut dysbiosis, especially the depletion of SCFAs-producing G+ bacteria. Additionally, depletion of SCFAs-producing G+ bacteria rather than G- bacteria intensified CP progression independent of TLR4, which was attenuated by supplementation with exogenous SCFAs. Finally, SCFAs modulated pancreatic fibrosis through inhibition of macrophage infiltration and M2 phenotype switching. The study supports a critical role for SCFAs-producing G+ bacteria in CP. Therefore, modulation of dietary-derived SCFAs or G+ SCFAs-producing bacteria may be considered a novel interventive approach for the management of CP.

Ursolic acid increases strength in mdx mice model and may decrease fibrosis deposition by tgf-ß downregulation / El ácido ursólico aumenta la resistencia en el modelo de ratones mdx y podría disminuir la deposición de fibrosis mediante la regulación decreciente de tgf-ß

SUMMARY: Dystrophin disfunction results in sarcolemma destabilization, leading muscle cell damage by continuous degeneration cycles and limited regeneration. In muscle dystrophy, caused by dystrophin dysfunction, inflammation, necrosis and fibrosis are pathophysiological muscle function loss characteristics. As a genetic disease, this muscle dystrophy has no cure, however, advances in drug therapy using glucocorticoids can decrease the disease progression. Subsequently, alternative therapies were studied, such as ursolic acid (UA), that inhibits muscle atrophy and increases muscle mass and strength. Herein, we used 10 mg/kg daily supplementation in mdx mice for 4 weeks to evaluate serum creatine phosphokinase (CPK), muscle strength (Kondziela test), muscular organization (histology) and expression of fibrosis related genes (TGF-ß, TNF-α, mstn and ostn). UA supplementation increased muscle morphological organization, motor strength and decreased muscular TGF-ß expression. Altogether, the gene expression profile, histological organization and strength could suggest that UA treatment did not stop the fibrogenesis but decreased its progress.

RESUMEN: La disfunción de la distrofina resulta en la desestabilización del sarcolema, llevando al daño de las células musculares por ciclos continuos de degeneración y regeneración limitada. En la distrofia muscular, debido a la disfunción de la distrofina, la inflamación, la necrosis y la fibrosis, son características fisiopatológicas de la pérdida de la función muscular. Como enfermedad genetica no es possible remediar esta distrofia muscular, sin embargo, los avances en la terapia de medicamentos con glucocorticoides pueden disminuir la progresión de la enfermedad. Se estudiaron terapias alternativas, como el ácido ursólico (UA), que inhibe la atrofia muscular y aumenta la masa y la fuerza muscular. En este estudio, utilizamos una suplementación diaria de 10 mg / kg en ratones mdx durante 4 semanas para evaluar la creatina fosfoquinasa (CPK) sérica, la fuerza muscular (prueba de Kondziela), la organización muscular (histología) y la expresión de genes relacionados con la fibrosis (TGF-ß, TNF- α, mstn y ostn). La suplementación con AU aumentó la organización morfológica muscular, la fuerza motora y la disminución de la expresión muscular de TGF-ß. El perfil de expresión génica, la organización histológica y la fuerza simultáneamente podrían sugerir que el tratamiento con AU no detuvo la fibrogénesis sino que disminuyó su progreso.

Dynamic phenotype of lung type Ⅱ alveolar epithelial cells in radiation-induced lung injury and its role in the formation of fibrosis / 中华放射医学与防护杂志

Objective:To explore the dynamic phenotype of type Ⅱ alveolar epithelial cells(AEC Ⅱ)in radiation-induced lung fibrosisand its role in the formation of fibrosis.Methods:Totally 90 C57BL/6J female mice were divided into 2 groups: irradiation group (50, thoracic irradiation with a single dose of 20 Gy X-rays), control group (40, sham irradiation). At 24 h, 4 and 12 weeks after irradiation, 5 mice were euthanized and the lungs were collected for pathological observation. The other lungtissues were collected for the isolation of primary AEC Ⅱ cells with microbeadssorting.The mRNA expressions of proSP-C, HOPX, vimentin, β-catenin and TGF-β1 in AEC II cells were detected by RT-PCR.Results:Acute pneumonitis was observed in the lungs at 24 h after irradiation and alleviated in accompany with partial alveolar septal thickening and a small amount of collagen deposition at 4 weeks after irradiation. The collagen deposition became more pronounced at 12 weeks after irradiation, together with collapsed and fused alveolar cavities, alveolar septal hyperplasia, and pulmonary fibrosis formation.The mRNAexpression levels of proSP-C and HOPX in primary AEC Ⅱ cells increased at 24 hours after irradiation and then approached to a peak value at 4 weeks after irradiation ( F=8.441, 3.586, P=0.036). The mRNA expression levels of vimentin, a biomarker of EMT, was increased significantly at 4 weeks and continued up to 12 weeks after irradiation( F=8.358, P=0.001). The mRNA expression levels of profibrotic factors β-catenin and TGF-β1 were both significant increased at 12 weeks after irradiation( F=4.62, 3.279, P=0.044). Conclusions:The phenotypeof AECⅡ cells could not only be transformed from proSP-C+ to HOPX+ /proSP-C+ , HOPX+ /proSP-C+ /vimentin+ , and vimentin+ /proSP-C, but also differentiated into mesenchymal cells with highly expressed profibrotic factors, thereby inducing EMT process, which either played a role in the repair of radiation-induced lung injury or triggered radiation-induced fibrosis.

C/EBPb converts bovine fibroblasts to adipocytes without hormone cocktail induction

BACKGROUND: Adipogenesis and fibrogenesis can be considered as a competitive process in muscle, which may affect the intramuscular fat deposition. The CCAAT/enhancer-binding protein beta (C/EBPb) plays an important role in adipogenesis, which is well-characterized in mice, but little known in bovine so far. RESULTS: In this study, real-time qPCR revealed that the level of C/EBPb was increased during the developmental stages of bovine and adipogenesis process of preadipocytes. Overexpression of C/EBPb promoted bovine fibroblast proliferation through mitotic clonal expansion (MCE), a necessary process for initiating adipogenesis, by significantly downregulating levels of p21 and p27 (p < 0.01). Also, the PPARc expression was inhibited during the MCE stage (p < 0.01). 31.28% of transfected fibroblasts adopted lipid-laden adipocyte morphology after 8 d. Real-time qPCR showed that C/EBPb activated the transcription of early stage adipogenesis markers C/EBPa and PPARc. Expression of ACCa, FASN, FABP4 and LPL was also significantly upregulated, while the expression of LEPR was weakened. CONCLUSIONS: It was concluded C/EBPb can convert bovine fibroblasts into adipocytes without hormone induction by initiating the MCE process and promoting adipogenic genes expression, which may provide new insights into the potential functions of C/EBPb in regulating intramuscular fat deposition in beef cattle.

lncRNA ZEB1-AS1 inhibits high glucose-induced EMT and fibrogenesis by regulating the miR-216a-5p/BMP7 axis in diabetic nephropathy

Diabetic nephropathy (DN) is one of the leading causes of mortality in diabetic patients. Long non-coding RNA zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) plays a crucial role in the development of various diseases, including DN. However, the molecular mechanism of ZEB1-AS1 in DN pathogenesis remains elusive. An in vitro DN model was established by treating HK-2 cells with high glucose (HG). Quantitative polymerase chain reaction (qRT-PCR) was utilized to detect the expression levels of ZEB1-AS1, microRNA-216a-5p (miR-216a-5p), and bone morphogenetic protein 7 (BMP7). Western blot assay was used to evaluate the protein levels of BMP7, epithelial-to-mesenchymal transition (EMT)-related proteins, and fibrosis markers. Additionally, the interaction among ZEB1-AS1, miR-216a-5p, and BMP7 was predicted by MiRcode (http://www.mircode.org) and starBase 2.0 (omics_06102, omicX), and confirmed by luciferase reporter assay. ZEB1-AS1 and BMP7 were down-regulated, while miR-216a-5p was highly expressed in kidney tissues of DN patients. Consistently, HG treatment decreased the levels of ZEB1-AS1 and BMP7, whereas HG increased miR-216a-5p expression in HK-2 cells in a time-dependent manner. ZEB1-AS1 upregulation inhibited HG-induced EMT and fibrogenesis. Furthermore, ZEB1-AS1 directly targeted miR-216a-5p, and overexpression of miR-216a-5p restored the inhibitory effects of ZEB1-AS1 overexpression on EMT and fibrogenesis. BMP7 was negatively targeted by miR-216a-5p. In addition, ZEB1-AS1 suppressed HG-induced EMT and fibrogenesis by regulating miR-216a-5p and BMP-7. lncRNA ZEB1-AS1 inhibited high glucose-induced EMT and fibrogenesis via regulating miR-216a-5p/BMP7 axis in diabetic nephropathy, providing a potential target for DN therapy.

[RETRACTED ARTICLE] lncRNA ZEB1-AS1 inhibits high glucose-induced EMT and fibrogenesis by regulating the miR-216a-5p/BMP7 axis in diabetic nephropathy

Diabetic nephropathy (DN) is one of the leading causes of mortality in diabetic patients. Long non-coding RNA zinc finger E-box binding homeobox 1 antisense 1 (ZEB1-AS1) plays a crucial role in the development of various diseases, including DN. However, the molecular mechanism of ZEB1-AS1 in DN pathogenesis remains elusive. An in vitro DN model was established by treating HK-2 cells with high glucose (HG). Quantitative polymerase chain reaction (qRT-PCR) was utilized to detect the expression levels of ZEB1-AS1, microRNA-216a-5p (miR-216a-5p), and bone morphogenetic protein 7 (BMP7). Western blot assay was used to evaluate the protein levels of BMP7, epithelial-to-mesenchymal transition (EMT)-related proteins, and fibrosis markers. Additionally, the interaction among ZEB1-AS1, miR-216a-5p, and BMP7 was predicted by MiRcode (http://www.mircode.org) and starBase 2.0 (omics_06102, omicX), and confirmed by luciferase reporter assay. ZEB1-AS1 and BMP7 were down-regulated, while miR-216a-5p was highly expressed in kidney tissues of DN patients. Consistently, HG treatment decreased the levels of ZEB1-AS1 and BMP7, whereas HG increased miR-216a-5p expression in HK-2 cells in a time-dependent manner. ZEB1-AS1 upregulation inhibited HG-induced EMT and fibrogenesis. Furthermore, ZEB1-AS1 directly targeted miR-216a-5p, and overexpression of miR-216a-5p restored the inhibitory effects of ZEB1-AS1 overexpression on EMT and fibrogenesis. BMP7 was negatively targeted by miR-216a-5p. In addition, ZEB1-AS1 suppressed HG-induced EMT and fibrogenesis by regulating miR-216a-5p and BMP-7. lncRNA ZEB1-AS1 inhibited high glucose-induced EMT and fibrogenesis via regulating miR-216a-5p/BMP7 axis in diabetic nephropathy, providing a potential target for DN therapy.

Expresión de TGF-p como indicio temprano de lesión del tejido hepático en la enfermedad de hígado graso no alcohólico / Expression of TGF-p as an early sign of liver tissue injury in nonalcoholic fatty liver disease

Resumen Introducción: la enfermedad de hígado graso no alcohólico (NAFLD) constituye un problema de salud pública asociado con el síndrome metabólico; su patogénesis implica el inicio de una cascada de señalización bioquímica compleja y su estimulación continua podría consolidar un proceso de fibrogénesis en el tejido. El objetivo del estudio fue analizar expresión de genes implicados en daño hepático, en los procesos iniciales de la lesión en pacientes con NAFLD o con factores de riesgo relacionados a esta patología, en búsqueda de biomarcadores moleculares útiles a la práctica clínica tales como TGF-pi, COL1A2 y MMP20. Metodología: estudio analítico de corte transversal. Se estudiaron características epidemiológicas, bioquímicas, y expresión génica de TGF-pU, COL1A2 y MMP20 en tejido hepático, en individuos con factores de riesgo para NAFLD. Resultados: se incluyeron 83 participantes con factores de riesgo asociados a NAFLD, 22 individuos (26.5%) fueron diagnosticados con NAFLD mediante ultrasonografía. Los factores de riesgo hallados fueron hipertensión arterial (50.6%), obesidad (49.4%), diabetes mellitus (34.9%) y dislipidemia (21.7%). La dislipidemia fue significativamente asociada con el riesgo de desarrollar NAFLD (OR=4; p=0.011). Se encontraron diferencias significativas para colesterol total (p<0.05); y una expresión génica de TGF--31 (con NAFLD p<0.0001 y sin NAFLD p<0.0001 frente al control) y COL1A2 (con NAFLD p=0.002 y sin NAFLD p=0.955 frente al control) con un patrón de expresión creciente a mayor grado de lesión hepática. Conclusión: para concluir, sugerimos activación de las vías de señalización que conducen a fibrogénesis en individuos con factores de riesgo para NAFLD, y mucho más acentuada en pacientes con NAFLD.

Abstract Introduction: nonalcoholic fatty liver disease (NAFLD) is a public health problem associated with the metabolic syndrome; its pathogenesis implies the start of a complex biochemical signaling cascade and its continuous stimulation could consolidate a fibrogenesis process in the tissue. The aim of the study was to analyze expression of genes involved in liver damage in the initial processes of the lesion in patients with NAFLD or with risk factors related to this pathology, in search of molecular biomarkers useful to clinical practice such as TGF--31, COL1A2 and MMP20. Methodology: cross-sectional analytical study. Epidemiological, biochemical, and gene expression characteristics of TGF--31, COL1A2 and MMP20 in liver tissue in individuals with risk factors for NAFLD were studied. Results: 83 participants with risk factors associated to NAFLD were included; 22 individuals (26.5%) were diagnosed with NAFLD by ultrasonography. The risk factors found were hypertension (50.6%), obesity (49.4%), diabetes mellitus (34.9%) and dyslipidemia (21.7%). Dyslipidemia was significantly associated with the risk of developing NAFLD (OR = 4; p = 0.011). Significant differences were found for total cholesterol (p <0.05); and a gene expression of TGF-P1 (with NAFLD p <0.0001 and without NAFLD p <0.0001 versus control) and COL1A2 (with NAFLD p = 0.002 and without NAFLD p = 0.955 versus control) with a pattern of increasing expression at higher degree of liver injury. Conclusion: to conclude, we suggest activation of the signaling pathways that lead to fibrogenesis in individuals with risk factors for NAFLD, and much more accentuated in patients with NAFLD.

Caracterização do imunofenótipo das células envolvidas no processo fibrótico de fígados bovinos cronicamente infectados por Fasciola hepatica / Immunophenotype characterization of the cells involved in the fibrotic process of bovine livers chronically infected by Fasciola hepatica

A fasciolose é uma doença parasitária causada por trematódeo do gênero Fasciola sp., que pode ocasionar fibrose hepática. Objetivou-se caracterizar o imunofenótipo das células que participam da fibrogênese de fígados bovinos frente à infecção por F. hepatica. Foram utilizados fragmentos dos lobos direito e esquerdo de 74 fígados bovinos com fasciolose. Os fragmentos foram submetidos a processamento histológico, coloração com tricrômico de Masson e imuno-histoquímica. Utilizaram-se análise estatística descritiva e teste de correlação de Spearmann com 5% de probabilidade. Na classificação do grau de fibrose, observou-se prevalência do grau 1, com associação positiva e significativa entre o grau de fibrose e o lobo hepático esquerdo (ρ=0,41; P<0,0001). Os imunofenótipos observados foram células estreladas hepáticas (CEHs) no parênquima e miofibroblastos (MFs) no espaço porta (EP). Não foram encontrados fibroblastos. Não houve correlação significativa entre o grau de fibrose e a quantidade de CEH nos lobos hepáticos, direito e esquerdo. Verificou-se aumento do número de estruturas portais, bem como do número de camadas circundando cada estrutura no EP, contudo não houve influência de qualquer estrutura sobre o grau de fibrose hepática (P>0,05). Concluiu-se que as células CEH e os MFs participam da fibrogênese de fígados bovinos com fasciolose crônica.(AU)

Fascioliasis is a parasitic disease caused by a fluke of the genus Fasciola sp., which can lead to end liver fibrosis. This study aimed to characterize the immunophenotype of cells that participate in the fibrogenesis of livers of cattle that face infection by F. hepatica. Fragments of the right and left lobes of 74 cattle livers with fascioliasis were used. The fragments were subjected to histological analysis, Masson's trichrome special stain, and immunohistochemistry. A descriptive statistical analysis was used, with a 5% probability in Spearman correlation test. The classification of degree of fibrosis revealed prevalence of grade 1, with a positive and significant association between the degree of fibrosis and the left hepatic lobe (ρ = 0.41; p <0.0001). The observed immunophenotypes corresponded to hepatic stellate cells (HSCs) in the parenchyma and myofibroblasts (MFs) in the portal tract (PT). Fibroblasts were not found. There was no significant correlation between the degree of fibrosis and the amount of HSC in right and left hepatic lobes. There was an increase in the number of portal structures, as well as in the number of layers surrounding each structure of the PT, but there was no influence of any structure of the PT on the degree of liver fibrosis (P>0.05). HSCs and MFs were concluded to play a role in the fibrogenesis of cattle livers with chronic fascioliasis.(AU)

Research progress on tumor ECM fibrogenesis in tumor metastasis / 中国药理学通报

Tumor metastasis is one of the most important biologi-cal characteristics of malignant tumor, and it is also the main factor resulting in poor prognosis and leading to failure of treat-ment. In recent years, studies have shown that the extracellular matrix ( ECM) of tumor microenvironment plays a critical role in tumor metastasis. Tumor ECM fibrogenesis could form the cross-linked network structure, which not only provides nutrition and support to tumor, also it is necessary to tumor growth and inva-sion. These research results indicate that blocking ECM fibro-genesis may exert an inhibitory effect on tumor metastasis. Therefore, targeting ECM fibrogenesis has become a particularly attractive strategy as it can be used in the treatment of metasta-sis-related diseases. The ECM fibrogenesis in tumor is reviewed in this paper as well as the treatment strategies on tumor metas-tasis by targeting ECM fibrogenesis, which may provide refer-ences for follow-up research and clinical treatment.

Dynamic expression of desmin, α-SMA and TGF-β1 during hepatic fibrogenesis induced by selective bile duct ligation in young rats

We previously described a selective bile duct ligation model to elucidate the process of hepatic fibrogenesis in children with biliary atresia or intrahepatic biliary stenosis. Using this model, we identified changes in the expression of alpha smooth muscle actin (α-SMA) both in the obstructed parenchyma and in the hepatic parenchyma adjacent to the obstruction. However, the expression profiles of desmin and TGF-β1, molecules known to be involved in hepatic fibrogenesis, were unchanged when analyzed by semiquantitative polymerase chain reaction (RT-PCR). Thus, the molecular mechanisms involved in the modulation of liver fibrosis in this experimental model are not fully understood. This study aimed to evaluate the molecular changes in an experimental model of selective bile duct ligation and to compare the gene expression changes observed in RT-PCR and in real-time quantitative PCR (qRT‐PCR). Twenty-eight Wistar rats of both sexes and weaning age (21-23 days old) were used. The rats were separated into groups that were assessed 7 or 60 days after selective biliary duct ligation. The expression of desmin, α-SMA and TGF-β1 was examined in tissue from hepatic parenchyma with biliary obstruction (BO) and in hepatic parenchyma without biliary obstruction (WBO), using RT-PCR and qRT‐PCR. The results obtained in this study using these two methods were significantly different. The BO parenchyma had a more severe fibrogenic reaction, with increased α-SMA and TGF-β1 expression after 7 days. The WBO parenchyma presented a later, fibrotic response, with increased desmin expression 7 days after surgery and increased α-SMA 60 days after surgery. The qRT‐PCR technique was more sensitive to expression changes than the semiquantitative method.

Effects of the administration of pentoxifylline and prednisolone on the evolution of portal fibrogenesis secondary to biliary obstruction in growing animals: immunohistochemical analysis of the expression of TGF-β and VEGF

OBJECTIVE: During the neonatal and infancy periods, some chronic liver diseases may lead to progressive hepatic fibrosis, which is a condition that can ultimately result in the loss of organ function and severe portal hypertension necessitating hepatic transplantation. In a previous report, pharmacological interventions were demonstrated to modulate hepatic fibrosis induced by bile duct ligation in young rats. The administration of pentoxifylline or prednisolone, or the combination of both, resulted in reduced fibrogenesis in portal spaces. The objectives of the present study were to evaluate the expression of transforming growth factor β and vascular endothelial growth factor after bile duct ligation in young rats and to assess the effect of those same drugs on cytokine expression. METHODS: In this experimental study, 80 young rats (21 or 22 days old) were submitted either to laparotomy and common bile duct ligation or to sham surgery. The animals were allocated into four groups according to surgical procedure, and the following treatments were administered: (1) common bile duct ligation + distilled water, (2) sham surgery + distilled water, (3) common bile duct ligation + pentoxifylline, or (4) common bile duct ligation + prednisolone. After 30 days, a hepatic fragment was collected from each animal for immunohistochemical analysis using monoclonal antibodies against transforming growth factor β and vascular endothelial growth factor. Digital morphometric and statistical analyses were performed. RESULTS: The administration of pentoxifylline reduced the transforming growth factor β-marked area and the amount of transforming growth factor β expressed in liver tissue. This effect was not observed after the administration of prednisolone. There was a significant reduction in vascular endothelial growth factor expression after the administration of either drug compared with the non-treatment group. CONCLUSIONS: The administration of pentoxifylline to cholestatic young rats resulted in the diminished expression of transforming growth factor β and vascular endothelial growth factor in liver tissue. The administration of steroids resulted in the diminished expression of vascular endothelial growth factor only. These pathways may be involved in hepatic fibrogenesis in young rats submitted to bile duct ligation and exposed to pentoxifylline or prednisolone.

Transforming growth factor-β-1 polymorphisms are infrequent but exist at selected loci in oral submucous fibrosis.

Background : Oral submucous fibrosis (OSF) may be considered a collagen metabolic disorder resulting from areca-nut alkaloid exposure and individual variation in collagen metabolism. Due to the complexity of OSF pathogenesis, it is important to elucidate independent and interactive effects of polymorphisms of collagen-related genes on OSF risk. Materials and Methods : This study is focused on seven polymorphisms (SNPs) of transforming growth factor-beta-1 (TGF-beta-1) gene in patients with oral submucous fibrosis (OSF), belonging to south Indian ethnic extraction. The mean age at presentation was 43.9 years, range 23-72 years (n=50, M:F ratio, 2.6:1). DNA samples from 50 subjects of the same ethnic group and comparable demographic features who have had practiced the habit of areca-chewing of almost equal duration, but remained free of disease constituted the controls. All DNA samples were collected progressively and purified from peripheral blood employing standard protocols and tested for SNPs. They included two polymorphisms in the promoter region (C-509T and G-800A), three polymorphisms in exon-1 (Arg25Pro(G915C), Leu10Pro(T869C), Glu47Gly(A979G) and two in 5 ͲUTR regions (C→T(rs13306708) and G→A (rs9282871). The extracted DNA samples along with the primers underwent PCR amplification and the genotypic and allelic frequencies were calculated. All calculations were performed using the SPSS software. The PCR products were purified and subsequently sequenced using Flour S™ multi-imager system (Biorad). The sequenced data were analyzed using the BioEdit sequence analysis software. Results : Out of the seven polymorphisms analyzed, six such as two in the promoter region, three in exon-1 and one in 5¢UTR were found to have a " P" value above 0.05 and hence were not significant. The C→T transition (rs13306708) in the 5¢UTR region recorded a " P" value of 0.03 on comparison and hence was found to be significant. The allelic frequencies for this C→T transition in patients were 68.7% C and 31.2% T (27CC, 15CT, 8TT) and that in controls were 89.5% C and 10.4% T (42CC, 6CT, 2TT). Conclusions : The polymorphism in 5¢UTR C-T in TGF beta 1 gene has a significant association with OSF, being a prime determinant in the pro-angiogenic pathway which has got direct bearing with the pathophysiology of the disease. The proximity of this polymorphism to the transcription site and the associated risk involved is discussed.

Mechanism of the transforming growth factor-â induction of fibronectin expression in hepatic stem-like cells

Transforming growth factor-â1 (TGF-â1) plays an important role in the fibrogenic process in the liver. The aim of the present study was to explore the action of TGF-â1 on fibronectin expression in rat hepatic stem-like cells and the underlying mechanisms. The level of fibronectin expression was determined in hepatic stem-like cells (WB cells) before and after TGF-â1 stimulation by RT-PCR and Western blot methods. Using immunogold transmission electron microscopy and the Western blot method, we observed the result of the expression and the distribution of cAMP, phosphorylated Smad3 and Smad7 before and after TGF-â1 treatment. The levels of fibronectin expression in both mRNA and protein increased 4- to 5-fold after TGF-â1 stimulation, reaching an optimum level after 8 h and then gradually falling back. Similarly, TGF-â1 stimulation resulted in an increase of cAMP in WB cells, peaking at 8 h. After treatment with TGF-â1 for 24 h, the expression of cAMP gradually decreased. In addition, we found that TGF-â1 treatment also contributed to the increased expression and to changes in cellular distribution of phosphorylated Smad3 (translocation from the cytoplasm to the nucleus) and Smad7 (translocation from the nucleus to the cytoplasm) in WB cells. The present study demonstrates that TGF-â is involved in the fibrogenic process in hepatic stem cells through up-regulation of fibronectin expression, and the mechanisms underlying this process may be associated with the activation of cAMP and Smad pathways.

Fibrosis intestinal y enfermedad de Crohn / Intestinal fibrosis and Crohn´s disease

Fibrogenesis in Crohn´s disease (CD) leads to intestinal stricture and fibrostenosing phenotype. Despite the remarkable success in the last years in medical therapies for CD, fibrostenosing phenotype is still difficult to deal with. Most of these patients need surgery trough their lives. There is a lot of information of fibrogenesis process on liver, lung or skin but we have fewer knowledge about the mechanisms involved in intestinal fibrosis. This article aims to review some of this factors and mechanisms associated to the development of fibrosis in CD. Probably, the identification of more elements that contribute to fibrogenesis in CD allow us in the future to have better treatments on patients and eventually to prevent this complication.

El fenómeno de fibrogénesis en la Enfermedad de Crohn determina el desarrollo de estenosis intestinal en un subgrupo de pacientes. A pesar del avance en el tratamiento de la Enfermedad de Crohn, el fenotipo estenosante sigue siendo de difícil manejo, requiriendo cirugía en la mayoría de los casos. Existe mucha información acerca de este proceso en otros tejidos como hígado, pulmón o piel. Sin embargo, a nivel del intestino, contamos con poco conocimiento acerca de los factores involucrados. Este artículo pretende hacer una revisión de algunos de los mecanismos involucrados en el desarrollo de la fibrosis intestinal en la Enfermedad de Crohn. Es probable que la identificación de más elementos que contribuyen al desarrollo de estenosis en EC, permitan a futuro un mejor manejo de estos pacientes y eventualmente en algunos casos la prevención de esta complicación.

Oxidized low-density-lipoprotein accumulation is associated with liver fibrosis in experimental cholestasis

OBJECTIVE: The aim of the present study was to examine the probable relationship between the accumulation of oxLDL and hepatic fibrogenesis in cholestatic rats. INTRODUCTION: There is growing evidence to support the current theories on how oxidative stress that results in lipid peroxidation is involved in the pathogenesis of cholestatic liver injury and fibrogenesis. One of the major and early lipid peroxidation products, OxLDL, is thought to play complex roles in various immuno-inflammatory mechanisms. METHODS: A prolonged (21-day) experimental bile duct ligation was performed on Wistar-albino rats. Biochemical analysis of blood, histopathologic evaluation of liver, measurement of the concentration of malondialdehyde (MDA) and superoxide-dismutase (SOD) in liver tissue homogenates, and immunofluorescent staining for oxLDL in liver tissue was conducted in bile-duct ligated (n = 8) and sham-operated rats (n = 8). RESULTS: Significantly higher levels of MDA and lower concentrations of SOD were detected in jaundiced rats than in the sham-operated rats. Positive oxLDL staining was also observed in liver tissue sections of jaundiced rats. Histopathological examination demonstrated that neither fibrosis nor other indications of hepatocellular injury were found in the sham-operated group, while features of severe hepatocellular injury, particularly fibrosis, were found in jaundiced rats. CONCLUSION: Our results support the finding that either oxLDLs are produced as an intermediate agent during exacerbated oxidative stress or they otherwise contribute to the various pathomechanisms underlying the process of liver fibrosis. Whatever the mechanism, it is clear that an association exists between elevated oxLDL levels and hepatocellular injury, particularly with fibrosis. Further studies are needed to evaluate the potential effects of oxLDLs on the progression of secondary biliary cirrhosis.

Immunohistochemical studies of stellate cells in experimental cholestasis in newborn and adult rats

BACKGROUND AND AIMS: Although there is much known about liver diseases, some aspects remain unclear, such as the nature of the differences between the diseases observed in newborn infants and those in adults. For example, how do newborns respond to duct epithelial cell injury? Do the stellate cells in newborns respond similarly to those in adults during biliary obstruction? METHODS: Ninety newborn Wistar rats aged six days, weighing 8.0 - 13.9 g each, and 90 adult rats weighing 199.7 - 357.0 g each, were submitted to bile duct ligation. After surgery, they were randomly divided and sacrificed on the 3rd, 5th, 7th, 14th, 21st or 28th day post-bile duct ligation. Hepatic biopsies were obtained and immunohistochemical semi-quantification of desmin and á-SMA expression was performed in hepatic stellate cells and in myofibroblasts in the portal space, and between the portal space and the liver lobule. RESULTS: Desmin expression in the myofibroblast cells post-bile duct ligation was higher in young rats, reaching its peak level in a shorter time when compared to the adult animals. The differences between the groups for á-SMA expression were less significant than for desmin. CONCLUSIONS: These findings indicate that there is an increase in the number of collagen-producing myofibroblast cells in young animals, suggesting that there is more intense fibrosis in this population. This finding may explain why young animals with bile duct obstruction experience more intense portal fibrosis that is similar to the pathology observed in the livers of newborns with biliary atresia.

Chronic Pancreatitis with Fibrogenesis / 한양의대학술지

Chronic pancreatitis is an ongoing inflammatory disorder characterized by irreversible destruction of the pancreas associated with disabling chronic pain and permanent loss of exocrine and endocrine function. Fibrosis and loss of acinar cell mass in the pancreas are characteristic findings in chronic pancreatitis, and pancreatic fibrosis is suggested to contribute to the irreversibility of the disease Over the past several decades, several theories have emerged to explain the pathogenesis and evolution of pancreatitis. These models provide conceptual frameworks that are not mutually exclusive, but at times are mutually contradictory. The role of pancreatic fibrogenesis in response to various forms of pancreatic injury and the relationship of fibrogenesis in response to the progression from acute to chronic form is emphasized within the sentinel acute pancreatitis event (SAPE) model of chronic pancreatitis. Studies on pancreatic fibrogenesis have been given new impetus, largely because of the identification and characterization of stellate-shaped cells in the pancreas. In the normal pancreas, pancreatic stellate cells (PSC) exist in a quiescent state. However in pancreatic injury, the PSCs are activated so that they exhibit increased proliferation, transformation onto myofibroblast-like cells and synthesize increased amounts of the extracellular matrix proteins that form fibrous tissues. Therefore, the PSCs have a central role in pancreatic fibrogenesis. Over the past several decades, the pathogenesis of chronic pancreatitis has been studied. However, the pathogenesis of chronic pancreatitis is unclear. Therefore, further studies would be needed to clarify the pathogenesis of chronic pancreatitis..

Hepatic Fibrogenesis / 대한소화기학회지

In acute injury, liver recovers completely without any scarring change or complication. However, large portion of liver is changed into fibrotic state by excessive production of extracellular matrix (ECM) under chronic injury. Excessive production of ECM results in hepatic fibrosis and repeated process of hepatic fibrosis progress into liver cirrhosis. Liver cirrhosis is an irreversible and terminal state of chronic liver disease and one of the major causes of death in Korea. To block the progression to liver cirrhosis, various studies in the field of virology and immunology have been proceeded. Recently, studies on the hepatic fibrogenesis have progressed with the development of molecular biology. Hepatic stellate cells (HSC) play a key role in the pathogenesis of hepatic fibrosis by producing ECM. The degree of hepatic fibrosis depends on the proliferation and activation of HSC and increased net production of collagen. Therefore, inhibition of HSC activation is one of the main ways to block the progression of hepatic fibrosis. Many kinds of factors such as oxidative stress, acetaldehyde, ascorbic acid, transforming growth factor-beta (TGF-beta) and carbon tetrachloride (CCl4) have been reported to activate HSC and stimulate collagen gene expression. Although there are no definite and effective antifibrogenic agents, possible candidates are antioxidants, interferon, retinoids such as beta-carotene, flavonoids, renin-angiotensin system inhibitors and peroxisome proliferator activated receptor-gamma (PPAR-gamma) agonists. We tried to evaluate the charateristics of HSC in order to develop agents that inhibit hepatic fibrogenesis.

HCV core protein promotes liver fibrogenesis via up-regulation of CTGF with TGF-beta1

Liver cirrhosis is one of the major complications of hepatitis C virus (HCV) infection, but the mechanisms underlying HCV-related fibrogenesis are still not clear. Although the roles of HCV core protein remain poorly understood, it is supposed to play an important role in the regulation of cellular growth and hepatocarcinogenesis. The aim of this study was to examine the role of HCV core protein on the hepatic fibrogenesis. We established an in vitro co-culture system with primary hepatic stellate cell (HSC) isolated from rats, and a stable HepG2-HCV core cell line which had been transfected with HCV core gene. The expressions of fibrosis-related molecules transforming growth factor beta1 (TGF-beta1), transforming growth factor b receptor II (TGF beta RII), alpha-smooth muscle actin (alpha-SMA) and connective tissue growth factor (CTGF) were analyzed via histological or molecular methods. In addition, the expression levels of matrix metaloprotinase-2 (MMP-2) and collagen type I (Col I) from the co-cultured media were measured by zymogram and ELISA, respectively. The expressions of alpha-SMA, TGF-beta1, Col I, TGF beta RII and MMP-2 were significantly increased in the co-culture of stable HepG2-HCV core with HSC. Moreover, the significant increases of CTGF and TGF-beta1 in the HCV core-expressing cells were observed by either Northern or Western blot analysis. These results suggest that HCV core protein may contribute to the hepatic fibrogenesis via up-regulation of CTGF and TGF-beta1.

The Role of Hepatitis C Virus Core Protein on Liver Fibrogenesis: A Study Using an In Vitro Co-culture System / 대한소화기학회지

BACKGROUND/AIMS: The study of liver fibrogenesis by hepatitis C virus (HCV) has been limited due to the lack of an efficiency in vitro culture systems. In the present study, we investigated whether or not HCV core protein is directly related to liver fibrogenesis through stimulation of hepatic stellate cells (HSC). METHODS: Human and rat HSC were isolated and we established an in vitro co-culture system of a stable HepG2-HCV core cell line which was transfected with HCV core gene and primary HSC. We performed immunocytochemical staining and Western and Northern blot analysis in the stimulated HSC by HCV ocre protein to identify the expression of transforming growth factor beta1 (TGF-beta1), transforming growth factor beta receptor II (TGFbeta R II), alpha-smooth muscle actin (alpha-SMA) and connective tissue growth factor (CTGF). The expression of matrix metaloprotinase-2 (MMP-2) and collagen type I (Col I) in the culture media were measured by zymogram and ELISA, respectively. RESULTS: The expression of TGF-beta1 and CTGF was significantly higher in the stable HepG2-HCV core cell line than in HepG2 cells. Furthermore, the makers related to fibrosis such as alpha-SMA, TGF-beta1, Col I, TGFRII and MMP-2 were highly experssed in the co-culture of stable HepG2-HCV core with HSC. CONCLUSIONS: HCV core protein may play a direct role in the fibrogenesis of chronic liver disease with HCV infection.