ERKs are the point of divergence of PKA and PKC activation by PTHrP in human skin fibroblasts

Parathyroid hormone-related peptide (PTHrP) receptors, coupled to trimeric G proteins, operate in most target cells through at least three different transduction routes: Galpha s-mediated stimulation of adenylylcyclase (AC), Galpha q-mediated activation of phospholipase Cbeta (PLC) and mitogen-activated protein kinase (MAPK) activation. In this study we investigated the relative role of different pathways in human skin fibroblast proliferation. Using chemical inhibitors and activators of signal transduction, we demonstrated that: (i) AC/cAMP and PLC/1,4,5 inositol triphosphate/diacylglycerol second-messenger systems are simultaneously activated following PTHrP binding to its receptors; (ii) the mitogenic response to PTHrP derives from a balance between two counteracting pathways--an activating route mediated by protein kinase C (PKC) and an inhibitory route mediated by protein kinase A (PKA); (iii) PTHrP mitogenic effects are largely dependent on MAPKs, whose activity can be modulated by both PKA and PKC. Our results indicate that MAPKs are common targets of both transduction routes and, at the same time, their point of divergence in mediating PTHrP dual and opposite mitogenic effects.

Skin biopsies for cell cultures from Mediterranean free-ranging cetaceans

The aim of this study was to develop a useful method for obtaining viable tissue samples for establishing cell cultures from skin biopsies of free-ranging cetaceans. The skin biopsies were performed by two methods: dart from an air gun and dart from a crossbow. The dart tip was modified to collect tissue. The tissue was kept in tissue culture medium at ambient temperature, then processed within 24 h. Many modifications in culture technique, with respect to conventional culture methods for human fibroblasts, were made. The cultures thus obtained can be used for many purposes, including genetic and toxicological studies. In toxicology they are an alternative in vitro system for studying threatened animals such as marine mammals. In particular, fibroblasts can be used to test the vulnerability of cetaceans and pinnipeds to different environmental contaminants such as organochlorine compounds, heavy metals and polycyclic aromatic hydrocarbons.

Iron mobilization from crocidolite as enhancer of collagen content in rat lung fibroblasts

Asbestos exposure causes pulmonary fibrosis by mechanisms that remain uncertain. There is increasing evidence that iron from asbestos is responsible for many of its effects. In this paper, we investigated the effect of iron mobilized from crocidolite asbestos on collagen content in rat lung fibroblast cultures under serum-free conditions. Crocidolite (2, 4, 6 microg/cm2 well) increased collagen content in a dose-dependent manner (+42 +/- 8, +92 +/- 10, and +129 +/- 13% vs controls). This effect was specific for collagen, since it did not alter total protein content and was inhibited by the iron chelator deferoxamine (DFO). Preincubation of crocidolite with citrate (1 mM) for 48 hr resulted in iron mobilization (51 microM) and increased collagen production (>3-fold) in treated cells. These effects occurred without the intervention of serum factors. The absence of cell damage, proliferation or lipid peroxidation leads to the supposition that iron from crocidolite per se may act as a profibrogenic agent. Although the in vivo participation of other cells and factors cannot be excluded, we conclude that iron released from crocidolite plays a role in collagen increase occurring during asbestosis.

Effect of S-carboxymethylcysteine lysine salt on mucociliary clearance in rabbits with secretory cell metaplasia

A single intratracheal instillation of porcine pancreatic elastase (PPE, 100 U/Kg) induces in rabbits bronchial secretory cell metaplasia as well as emphysematous changes. The mucus hypersecretion and the marked reduction of ciliated cells matched by a high percentage of atypical cilia are responsible for the delayed mucociliary clearance in this model. S-Carboxymethylcysteine lysine salt (SCMC-LYS, 0.35 g/Kg b.w.), given per os daily for 10 days starting 2 days before elastase administration, significantly ameliorated the mucociliary clearance. The pharmacological treatment did not modify the degree of secretory cell metaplasia and the percentage of atypical cilia, or prevent the alveolar wall destruction. At TEM examination, the morphological aspects of secretion occurring in bronchial tree of PPE-treated animals were rarely visible in the PPE + SCMC-LYS treated group. The beneficial effect of SCMC-LYS on mucociliary clearance may be ascribed to an antisecretagogue effect of this drug through elastase inhibition and to a reduction of mucus viscosity.

Collagen breakdown products and lung collagen metabolism: an in vitro study on fibroblast cultures

BACKGROUND

In fibrotic diseases such as pulmonary fibrosis there is evidence suggesting enhanced synthesis and degradation of lung connective tissue components, including collagen. It has therefore been hypothesised that products of collagen degradation may have a role in the promotion of collagen deposition. In support of this hypothesis, it has recently been shown that intravenous injection of lung collagen degradation products in experimental animals stimulated collagen synthesis leading to increased collagen deposition and diffuse interstitial lung disease.

METHODS

Rabbit and human fibroblast cultures from lung and skin were used as an in vitro model to study the responses of these cells to rabbit collagen degradation products. The effects of an acute exposure to collagen degradation products on synthesis of collagen and noncollagenous protein have been studied in confluent cultures by [3H]-proline incorporation. The effects of collagen degradation products on fibroblast proliferation and production of genetic types of collagen have also been investigated.

RESULTS

The acute exposure of rabbit lung fibroblast cultures to collagen degradation products significantly increased collagen synthesis without affecting non-collagenous protein synthesis. This effect was dose related, specific for lung fibroblasts, and species specific. Collagen degradation products altered the rate of synthesis of genetic types of collagen with a consequent decrease of type III/I+III collagen ratio (0.26 (0.04) treated with collagen degradation products; 0.45 (0.02) controls). These effects occurred without the intervention of serum factors. In addition, collagen degradation products neither affected fibroblast proliferation nor selected specific clones emphasising one type of collagen.

CONCLUSIONS

These results suggest that collagen degradation products can influence lung collagen metabolism by stimulating collagen synthesis. The regulation of collagen mass by collagen degradation products may be of importance in lung collagen homeostasis in vivo.

Neutrophil lysosomal dysfunctions in mutant C57 Bl/6J mice: interstrain variations in content of lysosomal elastase, cathepsin G and their inhibitors

In this paper we report the serum antiprotease screening and the biochemical and functional characteristics of neutrophils in a variety of mouse strains with different susceptibilities for developing a protease-mediated injury. C57Bl/6J mice and their mutants tight-skin and pallid have a lower serum elastase inhibitory capacity (-30, -65 and -70% respectively) than other inbred strains (i.e. NMRI and Balb/c, which both have similar values). We demonstrate that these values are a consequence of a decreased concentration of the alpha 1-protease inhibitor for elastase [PI(E)], which is the major serum inhibitor of elastase and cathepsin G. In addition, neutrophil lysosomal dysfunctions characterized by abnormally high contents of elastase and cathepsin G, or defective lysosomal secretion are observed in tight-skin and pallid mice respectively. Another C57Bl/6J mutant with lysosomal abnormalities is the beige mouse. Negligible amounts of elastase and cathepsin G, as well as defective neutrophil degranulation, have been described previously in this strain. We found, however, discrete amounts of a latent form of neutrophil elastase that undergoes a spontaneous activation by a protease-dependent mechanism. We also report that neutrophil cathepsin G in this mouse is tightly bound to lysosomal membranes, but is released in near normal quantities during exocytosis. Cytosolic elastase and cathepsin G inhibitors, which were previously reported as being specific for the beige neutrophils, have also been detected in all the examined strains. Neutrophil functions, lysosomal enzyme content and serum antiprotease screening may represent key elements in the protease-antiprotease balance and may explain the different interstrain susceptibility to developing lesions in which an elastolytic activity has been implicated.

Cardiac collagen changes during the development of right ventricular hypertrophy in tight-skin mice with emphysema

The tight-skin (Tsk) mouse is a genetic model of pulmonary emphysema. In this mouse, right ventricular hypertrophy (RVH) starts to develop at approximately 8 months of age, probably as a consequence of the emphysema. The aim of the present study was to investigate cardiac collagen synthesis, content, and types both before and during the development of RVH. Collagen synthesis, assessed by the [3H]proline incorporation method, was significantly increased in the right ventricle of 3-month-old Tsk mice. This was accompanied by a marked increase in right ventricle collagen content. Collagen typing showed no difference from controls. At 8 months of age collagen synthesis had returned to control values, right ventricular collagen content was elevated but held lower values than at 3 months, and collagen typing showed a prevalence of the more compliant type III. By 16 months of age, right ventricular collagen content had returned to control values and there was a shift in collagen types due to a relative increase of the more rigid type I. At 24 months of age right ventricular collagen content was increased again and collagen type I continued to predominate. These results suggest a dynamic role for collagen both before and during the development of RVH secondary to emphysema.

The pallid mouse. A model of genetic alpha 1-antitrypsin deficiency

BACKGROUND

The current hypothesis of pulmonary emphysema is based on an alteration of the protease-antiprotease balance within the lower respiratory tract. This hypothesis derives largely from studies in emphysema patients with genetic deficiency in serum alpha 1-antitrypsin. In animals, naturally occurring deficiency in serum elastase inhibitory capacity associated with early development of emphysema has been reported in the tight-skin mouse. We describe here a mouse model of genetic deficiency of alpha 1-antitrypsin in which emphysema occurs late in life.

EXPERIMENTAL DESIGN

A genetic deficiency in serum alpha 1-antitrypsin was investigated in pallid mice, a strain with spontaneous occurring emphysema. Additionally, the possible pathogenetic role of an elastase-anti-elastase imbalance in pallid mice was investigated using molecular biologic, biochemical, histologic, ultrastructural, and immunoelectron microscopic methods.

RESULTS

Pallid mice have markedly low levels of serum alpha 1-antitrypsin associated with a severe deficiency in serum elastase inhibitory capacity. However, they have normal alpha 1-antitrypsin mRNA levels in the liver. At ultrastructural examination, disruption of alveolar septa is first seen at 8 months of age. At histologic examination, some patchy areas of air-space enlargement with destruction of alveolar septa are seen from 12 months of age onward. These histologic changes are paralleled by a decrease in lung elastin content. The development of the pulmonary lesions is preceded by an alveolar elastolytic burden detected by an immunogold technique.

CONCLUSIONS

All these data suggest that the lung changes in pallid mice are the result of an elastolytic process due to a severe inborn deficiency of serum alpha 1-antitrypsin. This animal model reproduces important features of the human condition and may provide new insights into the pathogenesis of emphysema.

Lung collagen synthesis and deposition in tight-skin mice with genetic emphysema

The tight-skin (Tsk) mouse is a genetic model of pulmonary emphysema linked to a deficiency of serum antielastase. In this mouse occurrence of connective tissue abnormalities in various organs (systemic scleroderma) has been reported. The aim of the present work was to study lung collagen synthesis and deposition in Tsk mice. No differences in the collagen synthesis rate and morphology at the ultrastructural level were found in Tsk mice at birth. At 2 months of age, a marked increase in collagen was observed within the alveolar septa. At this time, an increased lung collagen synthesis, assessed by determining prolyl hydroxylase activity and incorporation of radiolabeled proline, was found in Tsk mice with respect to control mice. However, due to the ongoing parenchymal destruction, the values of total lung collagen at 6 and 12 months of age were only moderately but significantly increased with respect to those observed at 2 months. As a consequence, a progressive accumulation of lung collagen fibers was observed in the residual septa. The increase in collagen deposition was accompanied by a relative increase in type I collagen. Although the data in the literature would suggest a genetic cause for the lung collagen change in Tsk mice, the data presented here indicate that the change in lung collagen metabolism may be a part of a remodeling process taking place after lung destruction.

Identification of elastase in human eosinophils: immunolocalization, isolation, and partial characterization

Although an elastolytic activity in eosinophil-rich cell fractions from mice has been reported, this enzyme has not been purified and characterized as yet in any mammalian species. Eosinophilic elastase was isolated from human eosinophil fragments (cytosomes) obtained from normal and eosinophilic subjects. The enzyme was purified to apparent electrophoretic homogeneity by fast protein liquid chromatography. The enzyme shows the same physical properties of the major elastase isoenzyme of human neutrophils. In addition, like monocyte elastase, it reacts with a monoclonal antibody against human neutrophil elastase. The biochemical similarities observed between the above-mentioned enzymes and the immunolocalization findings strongly support the idea that human eosinophils and neutrophils contain the same enzyme activity. Eosinophils show immunoreactive material in both types of dense cytoplasmic granules. This observation supports the current hypothesis that the different types of eosinophilic granules represent successive morphological stages of maturation.

An elastolytic proteinase from rabbit leukocytes: purification and partial characterization

A proteinase with elastolytic activity was isolated from granules of rabbit bloodstream leukocytes, and purified to apparent homogeneity by a multi-step procedure consisting of ammonium sulfate precipitation, batch fractionation on DEAE-Sephadex A-50, and finally by preparative isoelectric focusing (IEF) on Sephadex G-75 Superfine. The molecule weight of the enzyme, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), was 28,500. This enzyme shows an isoelectric point at pH 9.0. The proteinase is active against natural elastins as well as toward Suc-(Ala)3-NA, Methoxy-Suc-(Ala)2-Pro-Val-NA, and (to a lesser extent) against Suc-(Ala)2-Pro-Leu-NA and Boc-Ala-ONp. The inhibition profile of the isolated enzyme indicates that rabbit granulocyte elastase belongs to the group of serine proteinases. Inhibition by some natural proteinase inhibitors is also observed. Unlike other mammalian elastases, it is insensitive to elastatinal.

Ultrastructural ciliary defects in children with recurrent infections of the lower respiratory tract

One hundred fifty-four children with recurrent or chronic infections of the lower respiratory tract compatible with the diagnosis of primary ciliary dyskinesia (PCD) were evaluated for the presence of ultrastructural ciliary abnormalities. Studies were performed on multiple samples of respiratory mucosa obtained by nasal and bronchial brushing. Twenty-eight children showed ultrastructural ciliary defects compatible with the diagnosis of PCD: Twenty-four presented dynein arm deficiency (either as isolated defect or in association with microtubular abnormalities), two had ciliary aplasia, and two showed microtubular abnormalities. Eleven patients with PCD had situs viscerum inversus, bronchiectasis, and chronic sinusitis (Kartagener's syndrome); one child with Kartagener's syndrome had normal ciliary structure. The appearance of respiratory symptoms within the first month of life, the colonization by Haemophilus influenzae, and a history of recurrent rhinitis and otitis were characteristically present in children with PCD. The clinical status of those patients who reached adolescence was, in our experience, remarkably good. An early diagnosis with adequate prevention and therapy of respiratory infections may have an important role in minimizing irreversible lung damage.

Hydrocephalus, bronchiectasis, and ciliary aplasia

A girl presented in the neonatal period with hydrocephalus, bronchiectasis, and ciliary aplasia. A common defect both in respiratory tract cilia and in ventricular ependyma cilia may explain the association of the two diseases.

Development of interstitial lung fibrosis by long-term treatment with collagen breakdown products in rabbits

We recently demonstrated that collagen breakdown products derived from elastase digestion (CDP) can stimulate "in vivo" lung collagen synthesis. The present work deals with the morphological and biochemical characteristics of an experimental model of lung fibrosis developed in rabbit by long-term treatment with CDP. Stimulation of collagen synthesis by CDP resulted in a significant thickening of alveolar septa due to accumulation of fibroblasts and a marked deposition of collagen fibrils as revealed by light as well as electron microscopy. Biochemical analysis confirmed the increase in lung collagen deposition. Total collagen content as determined by hydroxy-proline analysis was increased in CDP-treated animals of about 56% in respect to control animals. A relative increase of type I collagen in respect to type III was also observed. An additional interesting observation was a progressive hyperplasia of type II pneumocytes. Unlike other experimental models of lung fibrosis, the collagen deposition in our condition is not preceded or associated with inflammatory or degenerative processes. This fact renders this model very suitable to study matrix-cell interactions in pulmonary fibrogenesis.

In vivo stimulation of lung collagen synthesis by collagen derived peptides

In the present work we examined the "in vivo" effects of collagen breakdown products derived from elastase digestion on lung collagen synthesis in rabbits. It was found that i.v. injection of collagen peptides greatly enhances the collagen synthesis rate while does not affect the synthesis of non collagenous proteins. The increase of incorporation of 3H-proline in lung collagen parallels that of prolyl hydroxylase activity. The collagen synthesis, expressed as fractional rate (% day), amounted to 15% day in treated animals, resulting in a significant increase with respect to controls (11.7% day). The observations reported provide evidence that collagen breakdown products stimulate lung collagen synthesis and may play a role in collagen homeostasis.

Serum antielastase deficiency in tight-skin mice with genetic emphysema

The tight-skin (Tsk) mouse is a model of genetically determined emphysema. The cause for the development of the lung lesion is unknown. In the present study we investigated the lung morphometry and the serum elastase inhibitory capacity (EIC) of Tsk mice. Mean interalveolar distance was significantly greater (+60%) in Tsk mice than in C57 Bl/6J, NMRI, and Balb/c mice, which have similar values. Serum of Tsk mice against mouse leukocyte elastase (MLE) has significantly lower EIC values than that of NMRI, Balb/c (-64%), and C57 Bl/6J (-50%) mice. Similar results were obtained when porcine pancreatic elastase (PPE) was used. Against human leukocyte elastase (HLE), however, there was no difference among the strains, all of which had high EIC values. Preincubation of mouse (C57 Bl/6J) serum with chloramine-T (CT) resulted in an almost complete inhibition of EIC against MLE and PPE but only in a 20% inhibition against HLE using a synthetic substrate. Using elastin Congo Red as substrate, CT inhibited EIC against MLE and PPE by approximately 70% but did not affect the EIC against HLE. These results indicate that (1) the Tsk mouse can be considered a model of severe inborn deficiency of serum antielastase activity which is associated with emphysema; and (2) MLE and PPE can be considered interchangeable in studies of serum EIC in the mouse. On the other hand, the differences between MLE and HLE preclude the use of HLE for EIC determination in this species.

Immunoelectron-microscopic demonstration of elastase in emphysematous lungs of tight-skin mice

The tight-skin (Tsk) mouse has recently been proposed as a genetic model of emphysema. A morphometric study has shown that emphysema develops quickly, between 15 days and 1 month after birth. Previous biochemical and ultrastructural investigations of the lungs of 1- and 2-month-old Tsk mice revealed the presence of an ongoing elastolytic process. The goal of the present study was to investigate the role of mouse leukocyte elastase (MLE) in the development of emphysema in 1-month-old Tsk mice. Using electron microscopy and an immunogold labeling technique with rabbit anti-MLE IgG, MLE was localized within the lung neutrophils of control and Tsk mice. MLE was also found associated with elastin in the alveolar septa of Tsk but not of control mice. Little or no labeling was associated with other components (collagen, pneumocytes, and endothelium) of alveolar septa of Tsk mice. Lung elastin of control mice, or of control mice rendered emphysematous with porcine pancreatic elastase, showed negligible gold particle density when incubated with gold-conjugated rabbit IgG. Thus, under the present experimental conditions, an aspecific labeling of elastin is unlikely. This study indicates that MLE may be one of the factors responsible for the rapid development of emphysema in Tsk mice.

A biochemical and morphological investigation of the early development of genetic emphysema in tight-skin mice

The tight-skin (Tsk) mouse has recently been proposed as a genetic model of emphysema. In the present study, the development of emphysema was investigated in these mice with histological, biochemical, and ultrastructural methods at 4 days and at 1 and 2 months of life. At 4 days after birth, histological examination of the lungs revealed only a mild enlargement of the primary sacculi. Neither biochemical nor ultrastructural changes were seen however at this time. At 1 month of age, the histological examination showed marked emphysema-like changes, characterized by enlargment of air spaces accompanied by destruction of alveolar walls. Biochemical analysis showed a marked decrease in insoluble elastin content and a significant increase in salt-extractable collagen. Ultrastructural investigation revealed edema fluid in the interstitium and broken and disorganized elastic fibers. All these findings strikingly resemble the changes which occur in the lungs early after an instillation of elastase. In the 2-month-old Tsk mice the histological lesion progressed in severity. The ultrastructural findings were similar to those observed at 1 month, and the biochemical changes showed no signs of recovery. Thus, in these mice, the emphysematous lesion develops very rapidly between 4 days and 1 month of life and shows the characteristics of an elastolytic process which is still ongoing at 2 months of age.

A 16-month study of the development of genetic emphysema in tight-skin mice

The tight-skin (tsk) mouse has been recently proposed as a model of genetically determined emphysema. In the present study, the development of this lung lesion was investigated morphometrically in both male and female tsk mice from 4 days to 16 months of age. "Pallid" (pa) mice with a closely related genetic background served as controls. Despite small differences in the mean linear intercept seen at 1 and at 16 months, both male and female tsk mice were found to be similarly susceptible to the development of the emphysematous lesion. Three main phases were observed in the evolution of the emphysema. The first phase, from 4 days to 2 months after birth, included enlargement of the peripheral lung units, already evident at 4 and at 15 days, and destruction of the lung parenchyma, which occurred between 15 days and 1 month and rapidly progressed for as long as 2 months. A second phase of stabilization or of mild progression of the emphysematous lesion occurred between 2 and 8 months of age. A third phase, in the advanced age between 8 and 16 months, included a further exacerbation of the parenchymal destruction. At 16 months of age, the lungs of the pa mice also showed some patchy areas of air-space enlargement with destruction of the alveolar septa.

The saccharin method for testing mucociliary function in patients suspected of having primary ciliary dyskinesia

In order to evaluate the clinical value of the saccharin test as a practical and simple measure of mucociliary clearance, nasal mucociliary clearance (NMCC) and ciliary ultrastructure were studied in 22 patients suspected of having primary ciliary dyskinesia (PCD) based on the saccharin test. Ten patients fulfilling the diagnostic criteria of PCD had a pathological response to the saccharin test (transport time greater than 60 minutes), and this was consistently associated with ultrastructural defects, specific for PCD. These results validate the suitability of the clinical use of the saccharin test as a screening procedure for NMCC. The false-negative results obtained in three cases of PCD, all with borderline values, cannot be ascribed to ineffectiveness of the test, but rather to the persistence of some motility by certain defective cilia, detectable by microphoto-oscillographic investigation of specimens obtained by nasal biopsy or brushing.

Cilia-lacking respiratory cells in ciliary aplasia

This report describes the ultrastructural alterations observed in the nasal and bronchial mucosa of an 11-yr-old male suffering from immotile cilia syndrome (ICS). The morphological features observed in this patient are consistent with a ciliary aplasia. In fact, ciliated cells appeared to be replaced by columnar cells lacking cilia and basal bodies, and bearing on their surface cilium-like projections without any internal axonemal structure. In spite of the absence of basal bodies, centrioles, and kinocilia, these cells unexpectedly showed mature striated roots and centriolar precursor material scattered throughout the apical cytoplasm. These data suggest that control over basal body assembly is distinct from control over striated root formation. The presence of the above-reported structures in cells otherwise presenting many morphological features of normal ciliated cells is discussed on the basis of current knowledge of respiratory cilia biogenesis.

Isolation and partial characterization of a proteinase with elastolytic activity from mouse blood leukocytes

Leukocyte elastase has been implicated in the etiology of pulmonary emphysema. Recently, two genetic models of emphysema have been described, in mouse, which may enhance our understanding of the pathogenesis of emphysema. We therefore sought to purify mouse leukocyte elastase in order to characterize its biochemical properties. Leukocyte enzyme has been purified by a two-step procedure involving salt extraction of granular fraction, followed by preparative isoelectric focusing on Sephadex G-75 Superfine. The enzyme hydrolyses elastin and synthetic substrates for elastase, even if to a different extent. Inhibition studies indicates that the enzyme is a serine proteinase. Mouse elastase has a single isoelectric point of 8.65 and it behaves on sodium dodecyl sulphate polyacrylamide gel electrophoresis as a major band (molecular weight 29,000) and two minor bands (molecular weight 27,000 and 25,800, respectively.

Purification and partial characterization of elastase activity from rat alveolar and peritoneal macrophages

Macrophage elastase was purified from conditioned media from alveolar and thioglycollate-elicited peritoneal macrophages. The enzyme was purified to apparent electrophoretic homogeneity by preparative isoelectric focusing after a purification step consisting of low ionic strength dialysis and sequential batch fractionation on DEAE-Sephadex A-50. The proteinase activities isolated from alveolar and peritoneal macrophages showed the same physical and biochemical properties. This fact suggests that the same enzyme activity is present in rat macrophages of two different anatomical sites. The molecular weight and isoelectric point of the enzyme were estimated to be 22,500 and 8.3, respectively. The enzyme, characterized as a metallo proteinase, had elastolytic activity, as well as activity toward Suc-(Ala)3-NA. It is inhibited by o-phenanthroline, chicken ovoinhibitor, and EDTA, but not by phenylmethylsulfonyl fluoride or soybean trypsin inhibitor. The macrophage enzyme possesses biochemical and biophysical properties different from the rat pancreatic and granulocyte elastases (which are serine proteinases), and from the metallo proteinase with elastolytic activity isolated from rat platelets.

Bromotrichloromethane-induced damage to bronchiolar Clara cells

Administration of bromotrichloromethane (BrCCl3) to rats results in selective damage to bronchiolar non-ciliated Clara cells; ciliated bronchiolar cells and pneumocytes were unaffected. The cellular alterations begin very early (10 min) after poisoning. Lipid peroxidation, as measured by the malonic dialdehyde (MDA) content in the lung, is greatly increased 10 min after BrCCl3 administration. A histochemical technique to detect, in vitro, lipid peroxidation in frozen sections was used to demonstrate whether sufficient activation of BrCCl3 occurs in lung tissue. The positivity for the histochemical reaction was observed in bronchiolar epithelium in which cytochrome P450-dependent monooxygenase activity is predominantly located. The data obtained strongly support that BrCCl3 is highly metabolized in bronchiolar Clara cells.

Isolation and partial characterization of rat elastolytic enzymes from various cells and tissues

Different elastolytic enzymes were isolated from rat aorta and platelets, as well as from granulocyte and pancreatic extracts. The active fractions were purified to electrophoretic apparent homogeneity by precipitation with ammonium sulfate, sequential batch fractionation on DEAE-Sephadex A-50, and finally by isoelectric focusing (IF) on Sephadex G-75 Superfine. The molecular weight and the isoelectric point of the isolated enzymes were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and by analytical IF, respectively. All the enzymes have elastolytic activity as well as activity toward Suc-(Ala)3-NA. The inhibition profile of the different isolated enzymes toward various inhibitors indicates that aortic, pancreatic, and granulocyte enzymes all belong to the group of serine proteinases, unlike the platelet elastase which is a metalloproteinase.

Effect of the novel synthetic protease inhibitor furoyl saccharin on elastase-induced emphysema in rabbits and hamsters

Furoyl saccharin, a novel heterocyclic acylating agent which has been previously found to possess a potent inhibitory capacity in vitro for elastase and other serine proteases, has been investigated in vivo in two acute animal models of emphysema. In hamsters, intratracheal (i.tr.) administration of 0.1 mg porcine pancreatic elastase resulted seven days later, in a 42% increase of the mean linear intercept (Lm). Addition of 0.3 mg to 0.3 mg furoyl saccharin to elastase exhibited a partial, not dose-related, but statistically significant inhibition of the increase of LM. Addition of 1 mg furoyl saccharin (equivalent to a dose of 12.5 mg/kg) completely abolished the increase in Lm. In the rabbit i.tr. instillation of 3.7 mg porcine pancreatic elastase induced within seven days, a 48% increase of the Lm, a 27% decrease of the internal surface area (ISA) of the lungs and a 33% decrease of the ISA corrected to an arbitrary total lung volume of 70 ml (ISA70). Furoyl saccharin given i.tr. 15 min prior to elastase at the doses 3, 10 and 20 mg prevented significantly in a dose-related manner, the changes in Lm, ISA and ISA70. The highest furoyl saccharin dose (equivalent to a dose of 10.8 mg/kg) completely protected against the emphysematous lesion. Additionally furoyl saccharin (20 mg i.tr.) prevented in the rabbit model the depletion in lung insoluble elastin and the increase in salt soluble collagen induced by the elastase administration. These results show that furoyl saccharin also in vivo has a marked antielastase activity.

Severe teratospermia in an infertile man with bronchiectasis

Morphologic examination of sperm samples from an infertile man with bronchiectasis revealed a severe teratospermia characterized by rare abnormalities that were present in most of his spermatozoa. These abnormalities were represented by round-headed spermatozoa, changes in chromatin condensation, acrosomal alterations, multiple tails, and complete subcellular derangement. The similarity between the above-reported abnormalities and those observed in various species of laboratory animals strongly suggests that the observed defects might be the result of a defective function of the manchette during spermiogenesis. The absence of specific defects of the axonemal morphologic features in sperm tails and in respiratory cilia, together with some laboratory data, suggests that association between infertility and bronchiectasis cannot be related, in our patient, to a generalized syndrome.

Pulmonary vascular injury in pancreatitis: evidence for a major role played by pancreatic elastase

Using an experimental model of pancreatitis in the rat, the role of trypsin and elastase in mediating lung vascular injury in this condition was examined. The induction of pancreatitis by injection of sodium cholate in the pancreas resulted in a significant decrease in serum trypsin inhibitory capacity, and in a complete saturation of serum elastase inhibitory capacity matched by the appearance of endothelial injury of pulmonary capillaries and edema formation. The complete lack of serum elastase inhibitory capacity was associated with the presence of elastase activity in serum and bronchoalveolar lavage (BAL) fluids. The pretreatment of animals with N-furoyl saccharin (a potent inhibitor of many serine proteinases) prevented lung capillary injury and the imbalance of serum proteinase-anti-proteinase activities as well as the appearance of any elastolytic activity in serum and BAL fluids. These findings which clearly demonstrate the protease dependence of the pulmonary vascular injury in our experimental model, strongly suggested a major role for elastase(s). The suppression, in the experimental model, of the serum elastase inhibitory capacity by using chloramine-T resulted in an earlier onset of lung vascular damage, a marked worsening of pulmonary lesions, and an increase of elastolytic levels in serum and BAL fluids. Furthermore the physical properties of the protein molecule with enzyme activity detected in BAL fluids were consistent with those of rat pancreatic elastase. The reported data strongly support the hypothesis that pancreatic elastase plays a major role in the development of pulmonary vascular injury after acute pancreatitis.

Detection of elastase activity with a zymogram method after isoelectric focusing in polyacrylamide gel

A zymogram method for detecting elastase activity following isoelectric focusing in polyacrylamide gel is described. After enzyme activity has been visualized, the gel itself is available for protein staining and for analysis in sodium dodecyl sulfate-polyacrylamide gel electrophoresis in second dimension. The zymogram method is suitable for detecting microgram amounts of elastase and has one step only. It can be used with the purified enzyme as well as with crude extracts of tissue containing elastases showing activity toward succinyl-(Ala)3-p-nitroanilide. By this method a major component of elastase in both porcine and rat pancreas was detected. In addition, two forms of elastase with isoelectric points of 8.2 and 8.8, respectively, were identified in rat leukocyte extracts.