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Bleomycin Treatment (bleomycin + treatment)
Selected AbstractsLoss of ,1 integrin in mouse fibroblasts results in resistance to skin scleroderma in a mouse modelARTHRITIS & RHEUMATISM, Issue 9 2009Shangxi Liu Objective Activated adhesive signaling is a hallmark of fibroblasts isolated from the scars of scleroderma (systemic sclerosis) lesions. Beta-1 integrin plays a key role in adhesive signaling. The aim of the present study was to examine the role of ,1 integrin in a mouse model of skin scleroderma using mice bearing a fibroblast-specific deletion of ,1 integrin. Methods Cutaneous sclerosis was induced by subcutaneous injection of bleomycin. Control groups were treated with phosphate buffered saline. Mice bearing a fibroblast-specific deletion of ,1 integrin and control mice were investigated. Dermal thickness, collagen production, and the number of ,-smooth muscle actin,positive cells were determined. The quantity of the collagen-specific amino acid hydroxyproline was also measured. Results Bleomycin treatment induced marked cutaneous thickening and fibrosis in control mice. Conversely, the deletion of ,1 integrin resulted in resistance to bleomycin-induced fibrosis. Conclusion Expression of ,1 integrin by fibroblasts is required for fibrogenesis. Inhibition of ,1 integrin may be a viable method to alleviate the development of cutaneous sclerosis. [source] Loss of peroxisome proliferator,activated receptor , in mouse fibroblasts results in increased susceptibility to bleomycin-induced skin fibrosisARTHRITIS & RHEUMATISM, Issue 9 2009Mohit Kapoor Objective There is increasing evidence that the transcription factor peroxisome proliferator,activated receptor , (PPAR,) plays an important role in controlling cell differentiation, and that PPAR, ligands can modify inflammatory and fibrotic responses. The aim of the present study was to examine the role of PPAR, in a mouse model of skin scleroderma, in which mice bearing a fibroblast-specific deletion of PPAR, were used. Methods Cutaneous sclerosis was induced by subcutaneous injection of bleomycin, while untreated control groups were injected with phosphate buffered saline. Mice bearing a fibroblast-specific deletion of PPAR, were investigated for changes in dermal thickness, inflammation, collagen content, and the number of ,-smooth muscle actin,positive cells. The quantity of the collagen-specific amino acid hydroxyproline was also measured. In addition, the effect of PPAR, deletion on transforming growth factor ,1 (TGF,1) signaling in the fibroblasts was investigated. Results Bleomycin treatment induced marked cutaneous thickening and fibrosis in all treated mice. Deletion of PPAR, resulted in enhanced susceptibility to bleomycin-induced skin fibrosis, as indicated by increases in all measures of skin fibrosis and enhanced sensitivity of fibroblasts to TGF,1 in PPAR-deficient mice. Conclusion These results indicate that PPAR, suppresses fibrogenesis. Specific agonists of PPAR, may therefore alleviate the extent of the development of cutaneous sclerosis. [source] Investigation of sensory neurogenic components in a bleomycin-induced scleroderma model using transient receptor potential vanilloid 1 receptor, and calcitonin gene-related peptide,knockout miceARTHRITIS & RHEUMATISM, Issue 1 2008Árpád Szabó Objective Along with their classic afferent function (nociception), capsaicin-sensitive transient receptor potential vanilloid 1 (TRPV1) receptor,expressing sensory nerve terminals exert local and systemic efferent activities. Activation of TRPV1 causes sensory neuropeptide release, which modulates the inflammation process. The aim of the present study was to examine the role of this modulatory role of TRPV1 receptor and that of calcitonin gene-related peptide (CGRP) in bleomycin-induced scleroderma, using transgenic mice. Methods Cutaneous sclerosis was induced with daily subcutaneous injections of bleomycin for 30 days. Control groups were treated with phosphate buffered saline (PBS). TRPV1 receptor gene,deficient (TRPV1,/,) mice and CGRP-knockout (CGRP,/,) mice and their wild-type (WT) counterparts were investigated. A composite sclerosis score was calculated on the basis of thickening, leukocyte infiltration, and the amount/orientation of collagen bundles. Dermal thickness and the number of ,-smooth muscle actin (,-SMA),positive cells were also determined. The quantity of the collagen-specific amino acid hydroxyproline was measured by spectrophotometry. Results Bleomycin treatment induced marked cutaneous thickening and fibrosis compared with that observed in control mice treated with PBS. The composite sclerosis score was 18% higher, dermal thickness was 19% higher, the number of ,-SMA,positive cells was 47% higher, and the amount of hydroxyproline was 57% higher in TRPV1,/, mice than in their WT counterparts. Similarly, the composite sclerosis score was 47% higher, dermal thickness was 29% higher, the number of ,-SMA,positive cells was 76% higher, and the amount of hydroxyproline was 30% higher in CGRP,/, mice than in the respective WT groups. Conclusion These results suggest that activation of the TRPV1 receptor by mediators of inflammation induces sensory neuropeptide release, which might exert protective action against fibrosis. We confirmed the protective role of CGRP in the development of cutaneous sclerosis. [source] Cellular and molecular mechanisms of bleomycin-induced murine scleroderma: current update and future perspectiveEXPERIMENTAL DERMATOLOGY, Issue 2 2005Toshiyuki Yamamoto Abstract:, Scleroderma is a fibrotic condition characterized by immunologic abnormalities, vascular injury and increased accumulation of matrix proteins in the skin. Although the aetiology of scleroderma is not fully elucidated, a growing body of evidence suggests that extracellular matrix overproduction by activated fibroblasts results from complex interactions among endothelial cells, lymphocytes, macrophages and fibroblasts, via a number of mediators. Cytokines, chemokines and growth factors secreted by inflammatory cells and mesenchymal cells (fibroblasts and myofibroblasts) play an important role in the fibrotic process of scleroderma. Recently, we established a murine model of scleroderma by repeated local injections of bleomycin. Dermal sclerosis was induced in various mouse strains, although the intensity of dermal sclerosis varied among various strains. Histopathological and biochemical analysis demonstrated that this experimental murine scleroderma reflected a number of aspects of human scleroderma. Further investigation of the cellular and molecular mechanisms of inflammatory reaction, fibroblast activation and extracellular matrix deposition following dermal injury by bleomycin treatment will lead to the better understanding of the pathophysiology and the exploration of effective treatment against scleroderma. This review summarizes recent progress of the cellular and molecular events in the pathogenesis of bleomycin-induced scleroderma; moreover, further perspective by using this mouse model has been discussed. [source] Time course of bleomycin-induced lung fibrosisINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 3 2002G. Izbicki Summary. Intratracheal instillation (IT) of bleomycin is a widely used experimental model for lung fibrosis. In this study we describe the time-course of bleomycin-induced lung fibrosis in mice using computer-assisted morphometry. C57Bl/6J mice were treated with a single IT dose of bleomycin or control saline. Animals were killed 3, 6, 14 and 21 days post-IT. Lung injury was evaluated by analysis of bronchoalveolar lavage (BAL) fluid, hydroxyproline concentration in the lung, routine light microscopic examination resulting in a semiquantitative morphological index (SMI) of lung injury, and quantitative morphological measurements (fibrosis fraction and alveolar wall area fraction) aided by optimas image analysis software. Changes in BAL fluid attributed to bleomycin treatment include increased total cell count (days 14 and 21), and increased percentage of neutrophils (days 3 and 6) followed by a sustained increase in lymphocytes (days 6, 14 and 21). Hydroxyproline levels increased in bleomycin-treated mice on days 14 and 21. Median SMI grades were significantly elevated on days 3, 14 and 21. Computer-assisted morphometry demonstrated a 3-fold increase in fibrosis fraction and a 1.3-fold increase in wall area fraction in bleomycin-treated mice on day 14, with no further increase on day 21. These data also demonstrate that the most suitable time point for assessing lung fibrosis in this model is 14 days after IT instillation of bleomycin, based on the observation that at 14 days the animals developed extensive fibrosis, but had less variability in the fibrotic response and lower mortality than later at 21 days. Computer-assisted morphometry provides objective and quantitative measurements that are a useful tool for the evaluation of bleomycin-induced lung injury. [source] A case report: Primary extragonadal yolk sac tumor of penile shaft in a 2-year-old childINTERNATIONAL JOURNAL OF UROLOGY, Issue 4 2009Ryuto Nakazawa Abstract: A 2-year-old boy, who had the chief complaints of penile swelling and pain, was brought to the hospital by his mother. Penile contusion/trauma was suspected and he was admitted the same day to undergo emergency surgery to eliminate hematoma. The surgery revealed that the origin of the bleeding was not trauma but a tumor lesion of the penile shaft. It was histopathologically identified as a yolk sac tumor and no tumorous lesions were found except that in the penis. Therefore the patient was diagnosed as definitely having a yolk sac tumor originating in the penis. The patient received four cycles of cisplatin, etoposide and bleomycin treatment as adjuvant chemotherapy. Although it was impossible to completely resect the tumor, cisplatin, etoposide and bleomycin chemotherapy was effective and a complete response was achieved. We plan to carefully monitor the patient in the future. [source] Pivotal role of connective tissue growth factor in lung fibrosis: MAPK-dependent transcriptional activation of type I collagenARTHRITIS & RHEUMATISM, Issue 7 2009Markella Ponticos Objective Connective tissue growth factor (CTGF; CCN2) is overexpressed in systemic sclerosis (SSc) and has been hypothesized to be a key mediator of the pulmonary fibrosis frequently observed in this disease. CTGF is induced by transforming growth factor , (TGF,) and is a mediator of some profibrotic effects of TGF, in vitro. This study was undertaken to investigate the role of CTGF in enhanced expression of type I collagen in bleomycin-induced lung fibrosis, and to delineate the mechanisms of action underlying the effects of CTGF on Col1a2 (collagen gene type I ,2) in this mouse model and in human pulmonary fibroblasts. Methods Transgenic mice that were carrying luciferase and ,-galactosidase reporter genes driven by the Col1a2 enhancer/promoter and the CTGF promoter, respectively, were injected with bleomycin to induce lung fibrosis (or saline as control), and the extracted pulmonary fibroblasts were incubated with CTGF blocking agents. In vitro, transient transfection, promoter/reporter constructs, and electrophoretic mobility shift assays were used to determine the mechanisms of action of CTGF in pulmonary fibroblasts. Results In the mouse lung tissue, CTGF expression and promoter activity peaked 1 week after bleomycin challenge, whereas type I collagen expression and Col1a2 promoter activity peaked 2 weeks postchallenge. Fibroblasts isolated from the mouse lungs 14 days after bleomycin treatment retained a profibrotic expression pattern, characterized by greatly elevated levels of type I collagen and CTGF protein and increased promoter activity. In vitro, inhibition of CTGF by specific small interfering RNA and neutralizing antibodies reduced the collagen protein expression and Col1a2 promoter activity. Moreover, in vivo, anti-CTGF antibodies applied after bleomycin challenge significantly reduced the Col1a2 promoter activity by ,25%. The enhanced Col1a2 promoter activity in fibroblasts from bleomycin-treated lungs was partly dependent on Smad signaling, whereas CTGF acted on the Col1a2 promoter by a mechanism that was independent of the Smad binding site, but was, instead, dependent on the ERK-1/2 and JNK MAPK pathways. The CTGF effect was mapped to the proximal promoter region surrounding the inverted CCAAT box, possibly involving CREB and c-Jun. In human lung fibroblasts, the human COL1A2 promoter responded in a similar manner, and the mechanisms of action also involved ERK-1/2 and JNK signaling. Conclusion Our results clearly define a direct profibrotic effect of CTGF and demonstrate its contribution to lung fibrosis through transcriptional activation of Col1a2. Blocking strategies revealed the signaling mechanisms involved. These findings show CTGF to be a rational target for therapy in fibrotic diseases such as SSc. [source] | ||||||||||