Overexpression of tumor necrosis factor-alpha diminishes pulmonary fibrosis induced by bleomycin or transforming growth factor-beta.
ABSTRACT Tumor necrosis factor-alpha (TNF-alpha) is thought to be important in the development of pulmonary fibrosis. However, surfactant protein-C/TNF-alpha transgenic mice do not spontaneously develop pulmonary fibrosis but instead develop alveolar enlargement and loss of elastic recoil. We hypothesized that overexpression of TNF-alpha in the lung requires an additional insult to produce fibrosis. In this study we evaluated whether TNF-alpha overexpression altered the development of pulmonary fibrosis due to bleomycin or transforming growth factor-beta (TGF-beta). Either 0.2 U bleomycin or saline was administered into left lung of TNF-alpha transgenic mice and their transgene-negative littermates. To overexpress TGF-beta, an adenovirus vector containing either active TGF-beta (AdTGF-beta) or LacZ was administered at a dose of 3 x 108 plaque-forming units per mouse. Fibrosis was assessed histologically and by measurement of hydroxyproline. TNF-alpha transgenic mice tolerated bleomycin or AdTGF-beta, whereas the transgene-negative littermates demonstrated severe pulmonary fibrosis after either agent. An increase in prostaglandin E2 and downregulation of TNF receptor I expression were observed in the TNF-alpha transgenic mice. In addition, recombinant human TNF-alpha attenuated bleomycin-induced pulmonary fibrosis. TNF-alpha has a complex role in the development of pulmonary fibrosis. Endogenous TNF-alpha may be important in the development of fibrosis as indicated in other reports, but overexpression of TNF-alpha or exogenous TNF-alpha limits pulmonary fibrosis in mice.
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ABSTRACT: Inflammation is involved in renal fibrosis, a final common pathway for kidney diseases. To clarify how JAK/STAT/SOCS system was involved in renal fibrosis, UUO was induced in BALB/c or SOCS3(+/-) mice in the presence or absence of JAK inhibitor-incorporated nanoparticle (pyridine6-PGLA). UUO increased pSTAT3 and subsequently elevated SOCS3 levels in the obstructed kidneys. pSTAT3 levels were further increased in SOCS3(+/-) mice. UUO-induced renal fibrosis was markedly suppressed in SOCS3(+/-) mice, while it was aggravated by pre-treatment with pyridine6-PGLA. Although there were no differences in renal mRNA levels of TGF-β and collagens between wild and SOCS3(+/-) mice, MMP-2 activity was enhanced in SOCS3(+/-) UUO mice. Activated MMP-2 was completely suppressed by pyridine6-PGLA-pre-treatment. TNF-α one of JAK/STAT activators, increased pSTAT3 levels and subsequently induced MMP-2 activation in proximal tubular cells. These results suggest that JAK/STAT3 signaling may play a role in repair process of renal fibrosis in UUO partly via MMP-2 activation.Clinical Immunology 11/2013; 150(1):78-87. · 3.77 Impact Factor
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ABSTRACT: A compound was isolated from Centipeda minima using bioassay-guided screening. The structure of this compound was elucidated based on its spectral data, and it was identified as helenalin. The hepatoprotective effect of helenalin was evaluated using a liver fibrosis model induced by intragastric administration with alcohol within 24weeks in rats. The results revealed that helenalin significantly prevented alcohol-induced hepatic injury and fibrogenesis, as evidenced by the decrease in serum aminotransferase, the attenuation of histopathological changes, and the inhibition of the hepatic fibrosis indicators, such as hyaluronic acid, type III precollagen, laminin, hydroxyproline and collagen α type I. Mechanistically, studies showed that helenalin expedited ethanol metabolism by enhancing the alcohol and aldehyde dehydrogenase activities. Furthermore, helenalin alleviated lipid peroxidation, recruited the anti-oxidative defense system, inhibited CYP2E1 activity, and reduced the inflammatory mediators, including TGF-β1, TNF-α, IL-6 and IL-1β and myeloperoxidase, via down-regulation of NF-κB. Helenalin significantly decreased collagen deposition by reducing the profibrotic cytokines like transforming growth factor-β, platelet-derived growth factor-β and connective tissue growth factor, and promoted extracellular matrix degradation by modulating the levels of tissue inhibitor of matrix metalloproteinase-1 and matrix metalloproteinase-9. In addition, helenalin inhibited HSCs activation as evidenced by the down-regulation of α-SMA and TGF-β levels. In conclusion, helenalin had a significant protective effect on chronic ethanol-induced hepatic fibrosis and may be a major bioactive ingredient of Centipeda minima.Fitoterapia 01/2014; · 2.23 Impact Factor
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ABSTRACT: Background: The purpose of this work was to look into the effects of infliximab on wound healing in experimental glaucoma filtration surgery and to compare the antifibrotic effects of this agent to that of mitomycin-C (MMC). Methods: Twenty-eight male New Zealand White rabbits were randomly assigned to four groups, each including seven rabbits: control group, sham group, MMC group, and infliximab group. The rabbits in the control group were not operated on and did not receive any treatment. The rabbits in the sham group underwent trabeculectomy and had one drop of saline instilled four times a day for 14 days. The rabbits in the MMC treatment group underwent trabeculectomy, and a sponge soaked in 0.4 mg/mL MMC was applied intraoperatively to the scleral surgical site for three minutes. The rabbits in the infliximab treatment group underwent trabeculectomy and one drop of 10 mg/mL infliximab was instilled four times a day for 14 days after surgery. On day 14 of the experiment, the operated and control eyes were enucleated and histologically and immunohistochemically analyzed. Results: The mean fibroblast and mononuclear cell (MNC) numbers and the mean immunostaining intensities of transforming growth factor-β (TGF-β), fibroblast growth factor-β (FGF-β), and platelet-derived growth factor (PDGF) in the sham group were higher than those of the control group (P<0.01). The mean fibroblast and MNC numbers and the mean immunostaining intensities of TGF-β, FGF-β, and PDGF in the MMC and infliximab groups were statistically significantly lower than those of the sham group (P<0.01). The mean fibroblast and MNC numbers and the mean TGF-β, FGF-β, and PDGF immunostaining intensities of the MMC and infliximab groups were similar (P>0.05). Conclusion: Our study suggests that topical infliximab effectively suppresses the subconjunctival wound healing response after experimental glaucoma filtration surgery, reducing the MNC and fibroblast numbers and immunostaining intensities of TGF-β, FGF-β, and PDGF.Drug Design, Development and Therapy 01/2014; 8(-):421-429. · 3.49 Impact Factor