ABSTRACT
Conventional pleurodesing agents often provoke acute pleural inflammation followed by fibrosis. The inflammation frequently causes pain and fever. Transforming growth factor (TGF)-beta is a pro-fibrotic but anti-inflammatory cytokine. Intrapleural TGF-beta2 administration produces effective pleurodesis in animals, but its effects on mesothelial cells are unknown. The authors hypothesised that, unlike conventional pleurodesing agents, TGF-beta2 can induce collagen synthesis without stimulating pleural inflammation. In the in vitro studies, TGF-beta2, talc and doxycycline were administered to rabbit mesothelial cells for 24 h. These agents were also injected intrapleurally in rabbits and the induced pleural fluids collected at 24 h. TGF-beta2 was as potent as talc and doxycycline in upregulating mesothelial cell collagen expression. Talc and doxycycline both induced significant increases in interleukin (IL)-8 production from mesothelial cells in vitro and in rabbit pleural fluids in vivo. TGF-beta2, however, did not stimulate mesothelial cell IL-8 release in vitro and induced a dose-dependent suppression of pleural fluid IL-8. Pleural fluid IL-8 levels correlated significantly with leukocyte and lactate dehydrogenase concentrations in the fluids. In summary, transforming growth factor-beta was a potent inducer of mesothelial cell collagen synthesis. Unlike talc and tetracycline, which provoked pleural inflammation, transforming growth factor-beta2 suppressed pleural inflammation in vivo. Transforming growth factor-beta2 can produce effective pleural fibrosis without necessitating acute pleural inflammation.
Subject(s)
Collagen/biosynthesis , Epithelial Cells/drug effects , Epithelial Cells/metabolism , Interleukin-8/biosynthesis , Pleura/drug effects , Transforming Growth Factor beta/administration & dosage , Animals , Anti-Bacterial Agents/administration & dosage , Cells, Cultured , Dose-Response Relationship, Drug , Doxycycline/administration & dosage , Injections , Pleura/metabolism , Rabbits , Talc/administration & dosageABSTRACT
We examined the effects of dexamethasone treatment on nuclear factor (NF)-kappa B activation and lung inflammation in transgenic reporter mice expressing photinus luciferase under the control of an NF-kappa B-dependent promoter (HLL mice). In vitro studies with bone marrow and peritoneal macrophages derived from these mice showed that treatment with dexamethasone blocked luciferase induction after treatment with Escherichia coli lipopolysaccharide (LPS); however, treatment of mice with intraperitoneal injection of dexamethasone at doses of 0.3 microg/g and 1 microg/g failed to inhibit NF-kappa B-dependent luciferase activity in the lungs. Furthermore, intraperitoneal treatment with 10 microg/g of dexamethasone prior to LPS paradoxically resulted in augmented luciferase activity as compared with that of mice treated with LPS alone. NF-kappa B-dependent luciferase expression in the lungs was detected by bioluminescence imaging and by measurement of luciferase activity in homogenized lung tissue. In these studies, there was an excellent correlation between indirect measurement of luciferase activity by bioluminescence in living mice and direct measurement of luciferase activity in lung tissue. Dexamethasone treatment did not affect LPS-induced neutrophilic influx or the concentration of macrophage inflammatory protein-2 in lung lavage fluid. These findings emphasize the potential error of extrapolating in vitro findings to complex in vivo events such as regulation of inflammation.
Subject(s)
Dexamethasone/administration & dosage , Glucocorticoids/administration & dosage , NF-kappa B/drug effects , NF-kappa B/physiology , Animals , Lipopolysaccharides/administration & dosage , Macrophages/metabolism , Mice , Mice, TransgenicABSTRACT
Ascorbate contributes to several metabolic processes including efficient hydroxylation of hydroxyproline in elastin, collagen, and proteins with collagenous domains, yet hydroxyproline in elastin has no known function. Prolyl hydroxylation is essential for efficient collagen production; in contrast, ascorbate has been shown to decrease elastin accumulation in vitro and to alter morphology of elastic tissues in vivo. Ascorbate doses that maximally stimulated collagen production (10-200 microM) antagonized elastin biosynthesis in vascular smooth muscle cells and skin fibroblasts, depending on a combination of dose and exposure time. Diminished elastin production paralleled reduced elastin mRNA levels, while collagen I and III mRNAs levels increased. We compared the stability of mRNAs for elastin and collagen I with a constitutive gene after ascorbate supplementation or withdrawal. Ascorbate decreased elastin mRNA stability, while collagen I mRNA was stabilized to a much greater extent. Ascorbate withdrawal decreased collagen I mRNA stability markedly (4.9-fold), while elastin mRNA became more stable. Transcription of elastin was reduced 72% by ascorbate exposure. Differential effects of ascorbic acid on collagen I and elastin mRNA abundance result from the combined, marked stabilization of collagen mRNA, the lesser stability of elastin mRNA, and the significant repression of elastin gene transcription.
Subject(s)
Ascorbic Acid/physiology , Collagen/biosynthesis , Elastin/biosynthesis , Fibroblasts/metabolism , Muscle, Smooth, Vascular/metabolism , Skin/metabolism , Animals , Cells, Cultured , Connective Tissue/metabolism , Gene Expression Regulation , In Situ Hybridization , Oxidation-Reduction , RNA, Messenger/genetics , Swine , Transcription, Genetic/drug effects , Tropoelastin/metabolismABSTRACT
Elastin is rapidly deposited during late gestation in resilient tissues such as the arteries, lungs and skin owing to increased concentration of its mRNA. Pathological states can arise from congenital insufficiency or disorganization of elastin (cutis laxa). Other elastin deficiencies may be due to excess elastolysis or gene dosage effects. In the former, high turnover rates can be assessed by measurements of elastin degradation products in urine. Excess elastin accumulation by skin fibroblasts is characteristic of genetic diseases such as Buschke-Ollendorff syndrome, Hutchinson-Gilford progeria and keloid. Elastin expression is modulated by peptide growth factors, steroid hormones and phorbol esters, among which transforming growth factor beta (TGF-beta) is an especially potent up-regulator, acting largely through stabilization of mRNA. Recent evidence indicates cutis laxa fibroblasts that express little or no elastin have normal transcriptional activity but abnormal rates of elastin mRNA degradation. This defect is substantially reversed by TGF-beta through mRNA stabilization. Current studies explore the hypothesis that stability determinants lie within the 3' untranslated region of elastin mRNA. Post-transcriptional control of elastin expression appears to be a major regulatory mechanism.
Subject(s)
Elastin/biosynthesis , Animals , Cutis Laxa/metabolism , Fibrosis/metabolism , Humans , Keloid/metabolism , Progeria/metabolismABSTRACT
Presenta una metodología que sirva para la evaluación de impactos ambientales (EIA) de proyectos de saneamiento básico. La metodología es aplicada al proyecto de Tratamiento y Disposición Final de los Efluentes Cloacales de la ciudad de Palmira
Subject(s)
Argentina , Environment , Water Purification , Wastewater Disposal , Methods , Health Services ProgrammingABSTRACT
Realiza la evaluación de los impactos ambientales del proyecto de disposición final en terreno mediante el ordenamiento del área de reuso de los efluentes domésticos del Gran Mendoza evacuados en la Planta de Tratamiento de Campo Espejo. El análisis aporta elementos económicos para decidir con respecto al problema de la contaminación hídrica provocado por el uso desordenado y clandestino de dichos efluentes en el riego de cultivos
Subject(s)
Argentina , Wastewater Disposal , Wastewater Use , Agricultural Irrigation , EnvironmentABSTRACT
En el análisis realizado en este trabajo se aportan elementos económicos para decidir con respecto al problema de contaminación hídrica provocado por el uso desordenado y clandestino de los efluentes domésticos del gran Mendoza, en el riego de cultivos. La evaluación de impactos ambientales resulta, para un horizonte de 20 años y una tasa de costo de oportunidad del capital del 10
de alrededor $900.000.-, por lo que la rentabilidad del proyecto es muy satisfactoria
Subject(s)
Sanitary Engineering , River Pollution , CongressABSTRACT
Este estudio se realiza para identificar, prevenir e intepretar las consecuencias al bienestar humano y al entorno con el objeto de asegurar las inversiones que se lleven a cabo prevengan, controlen y/o mitiguen los efectos negativos sobre los recursos naturales y el bienestar de las personas
Subject(s)
Sanitary Engineering , Environment , CongressABSTRACT
Realiza la evaluación de los impactos ambientales del proyecto de disposición final en terreno mediante el ordenamiento del área de reuso de los efluentes domésticos del Gran Mendoza evacuados en la Planta de Tratamiento de Campo Espejo. El análisis aporta elementos económicos para decidir con respecto al problema de la contaminación hídrica provocado por el uso desordenado y clandestino de dichos efluentes en el riego de cultivos
Subject(s)
Argentina , Wastewater Disposal , Agricultural Irrigation , Environment , Wastewater UseABSTRACT
Presenta una metodología que sirva para la evaluación de impactos ambientales (EIA) de proyectos de saneamiento básico. La metodología es aplicada al proyecto de Tratamiento y Disposición Final de los Efluentes Cloacales de la ciudad de Palmira
Subject(s)
Argentina , Wastewater Disposal , Environment , Methods , Health Services Programming , Water PurificationABSTRACT
During tissue repair and development, matrix accumulation is modulated as multiple signals impinge on target cells. We have investigated the effects of combinations of the mitogenic cytokines, basic fibroblast growth factor (bFGF), transforming growth factor alpha (TGF-alpha), and insulin-like growth factor-1 (IGF-1) with transforming growth factor-beta 1 (TGF-beta 1) with respect to the production of two matrix components, elastin and type I collagen. Using specific enzyme-linked immunoassays for detection of secreted precursors in both vascular smooth muscle cells and skin fibroblasts from the domestic pig, production of these two fibrous proteins was shown to be strongly stimulated by TGF-beta 1. In the smooth muscle cell, both bFGF and TGF-alpha were potent antagonists of TGF-beta 1-mediated matrix production, whereas IGF-1 was only weakly additive with respect to elastin production. Antagonism was also evident to a lesser extent in skin fibroblasts. Reduced responsiveness to TGF-beta 1 did not appear to be due to a switch to a proliferative state, since TGF-beta 1 itself acted as a mitogen in confluent SMC, and TGF-alpha was only a weak mitogen in confluent fibroblast cultures. Although a predominant effect of TGF-beta is matrix accumulation, these findings suggest that this property will be significantly modified by the cytokine context.
Subject(s)
Collagen/biosynthesis , Cytokines/pharmacology , Elastin/biosynthesis , Muscle, Smooth, Vascular/metabolism , Skin/metabolism , Transforming Growth Factor beta/pharmacology , Animals , Cell Division/drug effects , Drug Combinations , Drug Interactions , Fibroblast Growth Factor 2/pharmacology , Fibroblasts/metabolism , Insulin-Like Growth Factor I/pharmacology , Muscle, Smooth, Vascular/cytology , Skin/cytology , Swine , Transforming Growth Factor alpha/pharmacologyABSTRACT
We describe a method using a semi-dry gel electro-blotter to transfer RNA from standard agarose-formaldehyde denaturing gels in less than 30 min. The method requires equilibrating the gel in a low ionic strength buffer. The transfer is done under high-current and low-voltage conditions. This method maintains the overall sharpness of the bands on the final autoradiogram while shortening the time required for Northern transfer by approximately 12 hours.
