Expression and localization of TIMP-1, TIMP-2, MMP-13, MMP-2, and MMP-9 in early and advanced experimental lung silicosis.
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Animals↗
Biomedical subjects
M Selman
Publications and source records attributed to M Selman.
Expression of matrix metalloproteinase 1 in rodents: comment on the article by Huebner et al.
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Animals↗
Human lung myofibroblast-derived inducers of alveolar epithelial apoptosis identified as angiotensin peptides.
Earlier work from this laboratory found that fibroblasts isolated from fibrotic human lung [human interstitial pulmonary fibrosis (HIPF)] secrete a soluble inducer(s) of apoptosis in alveolar epithelial cells (AECs) in vitro [B. D. Uhal, I. Joshi, A. True, S. Mundle, A. Raza, A. Pardo, and M. Selman. Am. J. Physiol. 269 (Lung Cell. Mol. Physiol. 13): L819-L828, 1995]. The cultured human fibroblast strains most active in producing the apoptotic activity contained high numbers of stellate cells expressing alpha-smooth muscle actin, a myofibroblast marker. The apoptotic activity eluted from gel-filtration columns only in fractions corresponding to proteins. Western blotting of the protein fraction identified immunoreactive angiotensinogen (ANGEN), and two-step RT-PCR revealed expression of ANGEN by HIPF fibroblasts but not by normal human lung fibroblasts. Specific ELISA detected angiotensin II (ANG II) at concentrations sixfold higher in HIPF-conditioned medium than in normal fibroblast-conditioned medium. Pretreatment of the concentrated medium with purified renin plus purified angiotensin-converting enzyme (ACE) further increased the ELISA-detectable ANG II eightfold. Apoptosis of AECs in response to HIPF-conditioned medium was completely abrogated by the ANG II receptor antagonist saralasin (50 microg/ml) or anti-ANG II antibodies. These results identify the protein inducers of AEC apoptosis produced by HIPF fibroblasts as ANGEN and its derivative ANG II. They also suggest a mechanism for AEC death adjacent to HIPF myofibroblasts [B. D. Uhal, I. Joshi, C. Ramos, A. Pardo, and M. Selman. Am. J. Physiol. 275 (Lung Cell. Mol. Physiol. 19): L1192-L1199, 1998].
Angiotensin II↗
Matrix metalloproteinases 2, 9, and 13, and tissue inhibitors of metalloproteinases 1 and 2 in experimental lung silicosis.
Exposure to silica induces granulomatous lung inflammation evolving to fibrosis through yet unclear pathogenic mechanisms. We examined the expression of extracellular matrix remodeling molecules: collagenase 3, gelatinases A and B, and TIMP-1 and TIMP-2 in experimental lung silicosis. Rats were instilled with 50 mg of silica and sacrificed after 15 and 60 d. At 60 d a significant increase in lung collagen content was found (170.2 +/- 34.4 versus 88.2 +/- 20.8 microgram/mg in controls, p = 0.01). Gelatin zymography of bronchoalveolar lavage fluid (BALF) from 15 and 60 d revealed bands of progelatinase A and progelatinase B, and lung tissue zymograms showed in addition, the active gelatinase A form at 15 d. By in situ hybridization and immunohistochemistry, early silicotic granulomas exhibited intense staining for all matrix metalloproteinases (MMPs) and TIMPs assayed. Labeling was restricted inside granulomas and surrounding areas. Late silicotic granulomas at 60 d showed lower MMP expression than did early lesions, and in highly fibrotic nodules scarce signal was usually found. TIMP-1 and TIMP-2 showed a moderate reduction in 60-d silicotic nodules. These findings suggest that an imbalance in the expression of MMPs and TIMPs may be implicated in extracellular matrix remodeling and basement membrane disruption during experimental lung silicosis.
Animals↗
Acidic fibroblast growth factor induces an antifibrogenic phenotype in human lung fibroblasts.
Acidic fibroblast growth factor (FGF-1), a prototype member of the heparin-binding growth factor family, influences proliferation, differentiation, and protein synthesis in different cell types. However, its possible role on lung extracellular matrix (ECM) metabolism has not been evaluated. In this study we examined the effects of FGF-1 and FGF-1 plus heparin on type I collagen, collagen-binding stress protein HSP47, interstitial collagenase (matrix metalloproteinase [MMP]-1), gelatinase A, and tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 expression by normal human lung fibroblasts. Heparin was used because it enhances the biologic activities of FGF-1. Fibroblasts were exposed either to 20 ng/ml FGF-1 plus 100 micrograms/ml heparin for 48 h or to FGF-1 or heparin alone. Messenger RNA (mRNA) expression was analyzed by Northern blot. Collagen synthesis was evaluated by digestion of [3H]collagen with bacterial collagenase, MMP-1 by Western blot, and gelatinolytic activities by zymography. Our results show that FGF-1 induced collagenase mRNA expression, which was strongly enhanced when FGF-1 was used with heparin. Likewise, both FGF-1 and FGF-1 plus heparin reduced by 70 to 80% the expression of type I collagen transcript, in part through effect on pro-alpha1(I) collagen mRNA stability. A downregulation of HSP47 gene expression was also observed. Synthesis of collagen and collagenase proteins paralleled gene expression results. FGF-1 activities were abolished with genistein, a tyrosine kinase inhibitor. Neither FGF-1 nor FGF-1 plus heparin affected the expression of TIMP-1, TIMP-2, and gelatinase A. These findings demonstrate that FGF-1, mostly in the presence of heparin, upregulates collagenase and downregulates type I collagen expression that might have a protective role in avoiding collagen accumulation during lung ECM remodeling.
Collagen↗
Human leukocyte antigen-associated susceptibility to pulmonary tuberculosis: molecular analysis of class II alleles by DNA amplification and oligonucleotide hybridization in Mexican patients.
BACKGROUND: Pulmonary tuberculosis (PTB) develops by a complex combination of environmental factors with genetic susceptibility. In this context, an association between human leukocyte antigens (HLAs) and tuberculosis has been examined in several populations, but results have been controversial. DESIGN AND MEASUREMENTS: A prospective evaluation of class II HLA genotypes was completed by the polymerase chain reaction (PCR) sequence-specific primer technique and PCR sequence-specific oligonucleotide hybridization in a Mexican population. SETTING: This study was conducted at the Clinical Service of Tuberculosis and the Department of Immunology, National Institute of Respiratory Diseases, Mexico City, Mexico. PATIENTS: Four groups were examined: 95 healthy subjects; 50 nonimmunosuppressed PTB patients; 15 HIV-infected patients (stage IVc in the Centers for Disease Control and Prevention [CDC] classification system for AIDS) with PTB; and 37 HIV-infected patients in the asymptomatic stage (CDC stage II). RESULTS: The frequencies of alleles DQA1*0101 (odds ratio [OR], 6.18; 95% confidence interval [CI], 2.38 to 16.08), DQB1*0501 (OR, 6.16; 95% CI, 2.44 to 17.71), and DRB1*1501 (OR, 7.92; 95% CI, 2.71 to 23.14) were significantly increased in nonimmunosuppressed patients with PTB when compared with healthy subjects. By contrast, frequencies of allele DQB1*0402 and antigens DR4 and DR8 were significantly decreased in patients with PTB. Additionally, a significantly higher frequency of the DRB1*1101 allele was found in HIV-positive subjects (OR, 6.67; 95% CI, 2.13 to 20.83). CONCLUSION: The genetic influence associated with the HLA system appears to have an important role in the development of PTB, although this susceptibility may not be relevant in patients with severe immunodeficiency diseases such as AIDS.
AIDS-Related Opportunistic Infections↗
Proteinase-antiproteinase imbalance in the pathogenesis of emphysema: the role of metalloproteinases in lung damage.
Pulmonary emphysema refers to a lung disorder characterized by a diffuse destruction of the alveolar walls resulting in enlargement of the distal airspaces. The disease is usually a chronic, progressive, and disabling disorder. The concept of proteinase/antiproteinase imbalance evolved from the identification of patients with alpha 1-antytripsin deficiency, and from the development of experimental emphysematous lesions using different enzymes. For a long time, this concept was seen as an elastase/antielastase imbalance, with the consequent degradation of elastin. Recent evidence, however, suggests that an intricate process of pulmonary remodeling occurs during the development of emphysema, where a complex network of serine proteases and metalloproteinases capable of degrading different extracellular matrix molecules, primarily, but not exclusively fibrillar collagens and elastin, are implicated in the pathogenesis of this disease.
Animals↗
[Single ventricle--case report].
A case of congenital heart disease (single ventricle) has been reported in nine and half years old child. This congenital heart disease is uncommon, but its diagnosis and treatment are complex. Complete noninvasive and invasive diagnostic procedure has been performed with this child. This congenital heart disease is proclaimed as inoperable because pulmonary hypertension has been developed.
Child↗
Gelatinases A and B are up-regulated in rat lungs by subacute hyperoxia: pathogenetic implications.
Subacute hyperoxia may cause basement membrane disruption and subsequent fibrosis. To test the role of extracellular matrix degradation in hyperoxic damage, we analyzed the expression of gelatinases A and B and tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2 in rats exposed to 85% O2. Oxygen-exposed rats were studied at 1, 3, 5, and 7 days, and compared with air-breathing rats. Lung mRNAs assayed by Northern and in situ hybridization showed an up-regulation of lung gelatinases A and B from the 3rd day on. Gelatinase A was localized in alveolar macrophages and in interstitial and alveolar epithelial cells. Gelatinase B mRNA and protein were localized in macrophages and bronchiolar and alveolar epithelial cells. Increased gelatinase A and B activities were demonstrated in bronchoalveolar lavage. TIMP-1 and TIMP-2 were constitutively expressed, and only TIMP-1 displayed a moderate increase with hyperoxia. To elucidate transcriptional mechanisms for increased gelatinase B expression after hyperoxia, nuclear transcription factor-kappabeta activation was explored. Oxidative stress significantly increased the lung expression of nuclear transcription factor-kappabeta (p65) protein, and nuclear transcription factor-kappabeta activation and increased levels of gelatinases A and B were found in isolated type II alveolar cells obtained from hyperoxic rats. Conceivably, subacute hyperoxia induces excessive gelatinase activity, which may contribute to lung damage.
Acute Disease↗
Airway involvement in hypersensitivity pneumonitis.
Exposure to organic particles causes, in a susceptible host, diffuse inflammation of the lung acinus. However, immunopathologic response may not be confined to the alveoli and may also involve the large and peripheral airways. Therefore, after allergen inhalation a clinical spectrum of respiratory disorders may be observed, including hypersensitivity pneumonitis, asthma, chronic airway obstruction, and simple chronic bronchitis. Hypersensitivity pneumonitis is not a uniform disease but a complex syndrome, and the involvement of the airways may occur alone, simultaneously with, or after the parenchymal disease.
Alveolitis, Extrinsic Allergic↗
Cell size, cell cycle, and alpha-smooth muscle actin expression by primary human lung fibroblasts.
Primary human lung fibroblasts were separated into small (group I), intermediate (group II), and large (group III) subpopulations by unit gravity sedimentation (1 G). The three subsets retained differences in cell size for up to 15 days of primary culture. Flow cytometric (fluorescence-activated cell sorter) measurements of forward-angle light scatter agreed well with fibroblast volume measured by image analysis and confirmed the utility of forward-angle light scatter for discriminating size subpopulations. Group II fibroblasts accumulated most rapidly by 8 days of culture and also contained the greatest proportion of S and G2/M phase cells as determined by fluorescence-activated cell sorter. Fibroblasts that were immunoreactive with antibodies to alpha-smooth muscle actin (alpha-SMA) were found only in group III. In situ end labeling of fragmented DNA detected apoptotic cells in both groups II and III, but double labeling for in situ end labeling and alpha-SMA revealed apoptotic cells in both the alpha-SMA-positive and -negative populations. These results demonstrate that primary human lung fibroblasts behave as predicted by classic models of cell cycle progression and differentiation. However, they do not support the hypothesis that the expression of alpha-actin is related to apoptosis. We also describe a simple and reproducible method for the high-yield isolation of human lung fibroblast subsets of differing proliferative potential and phenotype.
Actins↗
Alveolar epithelial cell death adjacent to underlying myofibroblasts in advanced fibrotic human lung.
Earlier work from this laboratory showed that abnormal fibroblast phenotypes isolated from fibrotic human lung produce factor(s) capable of inducing apoptosis and necrosis of alveolar epithelial cells in vitro [B. D. Uhal, I. Joshi, A. True, S. Mundle, A. Raza, A. Pardo, and M. Selman. Am. J. Physiol. 269 (Lung Cell. Mol. Physiol. 13): L819-L828, 1995]. To determine whether epithelial cell death is associated with proximity to abnormal fibroblasts in vivo, the spatial distribution of epithelial cell loss, DNA fragmentation, and myofibroblasts was examined in the same tissue specimens used previously for fibroblast isolation. Paraffin sections of normal and fibrotic human lung were subjected to in situ end labeling (ISEL) of fragmented DNA and simultaneous immunolabeling of alpha-smooth muscle actin (alpha-SMA); replicate samples were subjected to electron microscopy and detection of collagens by the picrosirius red technique. Normal human lung exhibited very little labeling except for positive alpha-SMA immunoreactivity of smooth muscle surrounding bronchi and vessels. In contrast, fibrotic human lung exhibited moderate to heavy ISEL of interstitial, cuboidal epithelial, and free alveolar cells. ISEL of the alveolar epithelium was not distributed uniformly but was most intense immediately adjacent to underlying foci of alpha-SMA-positive fibroblast-like interstitial cells. Both electron microscopy and picrosirius red confirmed epithelial cell apoptosis, necrosis, and cell loss adjacent to foci of collagen accumulation surrounding fibroblast-like cells. These results demonstrate that the cuboidal epithelium of the fibrotic lung contains dying as well as proliferating cells and support the hypothesis that alveolar epithelial cell death is induced by abnormal lung fibroblasts in vivo as it is in vitro.
Apoptosis↗
72-kD (MMP-2) and 92-kD (MMP-9) type IV collagenase production and activity in different histologic types of lung cancer cells.
In this study we examined the production of gelatinases A and B (MMP-2 and MMP-9), and their natural inhibitors TIMP-1 and TIMP-2 in cell lines derived from different histologic types of lung cancer. Gelatinolytic activity was measured by zymography and radiolabeled gelatin degradation. Immunocytochemistry and Western blot analysis were performed to corroborate the presence of immunoreactive MMP-2, MMP-9, TIMP-1 and TIMP-2 proteins. The highest gelatinolytic activity was identified in the cell extracts from a small-cell carcinoma cell line. MMP-9 was observed in all samples as a proenzyme, while MMP-2 was present as zymogen in the squamous-cell and in the small-cell carcinomas, and in its active form in one squamous-cell carcinoma cell line. TIMPs were also present in the neoplastic lung cell lines. TIMP-1 was observed in the media of all cells as a 21-kD band, and as TIMP-1 polymers with the exception of the small-cell carcinoma samples. TIMP-2 was found as higher-order molecular immunoreactive complexes that may correspond to proMMP-2/TIMP-2 complexes. These results demonstrate that lung neoplastic cells produce both MMP-2 and MMP-9 and their inhibitors, with the small-cell carcinoma cell extracts showing the highest enzymatic activity. This gelatinolytic activity fits well with the clinical metastatic behavior of this type of lung cancer.
Blotting, Western↗
Utility of a provocation test for diagnosis of chronic pigeon Breeder's disease.
Chronic hypersensitivity pneumonitis (CHP) can be difficult to differentiate from other interstitial lung diseases (ILD). To determine the diagnostic usefulness of a provocation test (PT), 17 patients with CHP induced by avian antigens, 17 with other ILD, and five healthy control subjects were challenged with pigeon serum. After PT, an increase in body temperature (BT) and a decrease in FVC, PaO2 and SaO2% were observed in all patients with CHP and in three with ILD. No reaction was noticed in healthy subjects. ROC curves showed that for FVC the best cut point was a drop of 16% displaying sensitivity (S): 76%, specificity (SP): 81%, positive predictive value (PPV): 81%, and negative predictive value (NPV): 83%. For a drop of 3 mm Hg in PaO2 or 3% SaO2, S was 88% for both, SP was 82 and 86%, PPV was 81 and 82%, and NPV was 82 and 86%, respectively. An increase of BT > 0.5(o) C showed S, 100%; SP, 82%; PPV, 100%; NPV, 86%. A univariate regression analysis confirmed that changes in BT and FVC are predicting values of CHP: RR, 82.5 (CI, 10.43 to 651.76) and 1.21 (CI, 1.06 to 1.36). There were no challenge test complications. These findings suggest that PT is a useful tool for diagnosis of CHP.
Adult↗
Colchicine, D-penicillamine, and prednisone in the treatment of idiopathic pulmonary fibrosis: a controlled clinical trial.
STUDY OBJECTIVE: We compared the long-term efficacy of the combination of colchicine and/or D-penicillamine with prednisone, in comparison to prednisone alone in patients with idiopathic pulmonary fibrosis (IPF). DESIGN: Nonrandomized prospective study in patients with IPF confirmed by biopsy specimen. SETTING: National Institute of Respiratory Diseases, Mexico. PATIENTS: Fifty-six IPF patients were included in this study. Patients received either colchicine/ prednisone (n=19), D-penicillamine/prednisone (n=11), D-penicillamine/colchicine/prednisone (n=11), or prednisone alone (n=15). Prednisone therapy was started at 1.0 mg/kg/d for 1 month followed by a biweekly taper to a maintenance dose of 15 mg/d. Colchicine was administered at a daily dose of 1.0 mg, and D-penicillamine was given at a daily dose of 600 mg. MEASUREMENTS AND RESULTS: Response to therapy was assessed by changes in lung function test results as measured by total and vital lung capacities, arterial blood gas analysis at rest breathing room air, and survival. No significant differences either in lung mechanics or in arterial gases were found in any group relative to the baseline measurement. Thirteen of the 56 patients died during the first 2 years, and 29 were dead at 5 years follow-up. Comparison of survival curves by Cox regression model showed no statistically significant difference among the four groups. Known side effects attributable to prednisone were more common and severe than those attributable to the other drugs. CONCLUSIONS: Our results suggest that neither colchicine nor D-penicillamine modified the progressive course of prednisone-treated IPF, and that the search for new drugs is imperative.
Adult↗
Problems encountered in high-level research in developing countries.
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Developing Countries↗
Lung alveolar epithelial cells synthesize interstitial collagenase and gelatinases A and B in vitro.
Type II pneumocytes are multifunctional alveolar epithelial cells that play a major role in the maintenance of lung structure and function. Recent evidence supports that these cells can synthesize a variety of extracellular matrix components in vitro, suggesting an active participation in connective tissue remodeling. However, their possible role in extracellular matrix degradation is unknown. In this study the production of matrix metalloproteinases (MMPs) was examined in primary cultures of rat alveolar type II pneumocytes after 2 and 7 days in culture. Under basal conditions, at both periods type II cells expressed interstitial collagenase mRNA. The immunoreactive protein was detected both in the cells and in conditioned media, and collagenolytic activity was revealed after trypsin activation. Gelatinolytic activity was detected by zymography showing a relative molecular mass of approximately 72 and 92 kDa (gelatinases A and B). Phorbol treatment increased collagenase and gelatinase activities. In addition, three alveolar epithelial cell lines were analysed for MMP production: MLE-12 (mice), L2 (rat), and A549 (human). The cell lines A549 and MLE-12 revealed collagenase and gelatinase A and B activities whereas the L2 cell line only exhibited gelatinase A activity, even after PMA induction. These findings demonstrate that alveolar epithelial cells synthesize in vitro several MMPs that confer on them the ability to degrade extracellular matrix and basement membrane components, a capacity of considerable importance for the remodeling of the stromal/epithelial interface.
Animals↗
Upregulation of acidic fibroblast growth factor during development of experimental lung fibrosis.
Fibroblast proliferation and extracellular matrix accumulation are crucial in the pathogenesis of lung fibrosis. Fibroblast growth factor (FGF)-1 participates in both processes, but its role in lung fibrogenesis has not been evaluated. We analyzed the expression of FGF-1 and of FGF receptor (FGFR) in a model of lung fibrosis induced in rats with paraquat plus hyperoxia. Experimental and control animals were killed at 48 h and 2, 4, and 8 wk, and the lungs were studied by in situ hybridization, immunohistochemistry, and Northern blot. In normal lungs, scattered macrophages contained FGF-1. In contrast, at all times examined, the injured lungs exhibited FGF-1 transcript and the immunoreactive protein, mainly in alveolar epithelial cells and macrophages. In advanced fibrotic lesions, fibroblasts also appeared stained. Northern blot corroborated the upregulation of FGF-1 mRNA. FGFR was not observed in normal lungs, whereas it was strongly increased in the damaged lungs and was virtually immunolocalized in the same cell types as the corresponding ligand. These findings suggest that FGF-1 and FGFR are actively synthesized during the development of pulmonary fibrosis.
Animals↗