Effect of high dose inhaled steroid on cells, cytokines, and proteases in induced sputum in chronic obstructive pulmonary disease

Inhaled corticosteroids are widely prescribed for the treatment of stable chronic obstructive pulmonary disease (COPD), despite lack of proven efficacy. Because COPD involves airway inflammation and probable protease-antiprotease imbalance, we examined the effect of high dose fluticasone propionate on markers of activity of both pathogenetic mechanisms. Thirteen patients with COPD were treated with fluticasone propionate (500 microg twice a day) for 4 wk, delivered via MDI and spacer, in a double-blind crossover study. There was no clinical benefit in terms of lung function or symptom scores, and induced sputum inflammatory cells, percentage neutrophils, and IL-8 levels were unchanged. Sputum supernatant elastase activity, matrix metalloproteinase (MMP)-1, MMP-9, and the antiproteases secretory leukoprotease inhibitor (SLPI) and tissue inhibitor of metalloproteinase (TIMP)-1 were similarly unaffected by treatment. These results add to previous evidence that inhaled steroids have no anti-inflammatory action in stable COPD. Furthermore, inhaled steroids do not appear to redress the protease-antiprotease imbalance that is thought to be important in the pathogenesis of airway obstruction.

Bronchiolitis obliterans syndrome after (heart-)lung transplantation. Impaired antiprotease defense and increased oxidant activity

Increased numbers of neutrophils are a common finding in bronchoalveolar lavage fluid (BALF) samples obtained from patients after (heart-)lung transplantation [(H)LTX]. Since proteases and reactive oxygen species secreted by neutrophils are capable of causing substantial damage to the lung tissue if not counterbalanced by the antiprotease and antioxidant screen, we hypothesized that neutrophil products may play a role in the development of obliterative bronchiolitis (OB). A total of 72 BALF samples obtained from 33 patients after (H)LTX were evaluated. Sixteen of these patients were suffering from bronchiolitis obliterans syndrome (BOS) at the time of bronchoalveolar lavage (BAL). As a control, BALF samples from 17 healthy volunteers were analyzed. Anti-neutrophil elastase (NE) activity was quantified by a titration assay. Concentrations of alpha(1)-protease inhibitor (API), secretory leukocyte protease inhibitor (SLPI), NE-API complex, and myeloperoxidase (MPO) were measured by ELISA. Oxidized methionine [Met(O)] was quantified by high-performance liquid chromatography (HPLC). Epithelial lining fluid (ELF) from patients suffering from BOS showed significantly increased neutrophil counts, significantly elevated concentrations of NE-API complex and Met(O), and a significant decrease in the concentration of SLPI. Furthermore, a trend toward an increased NE activity and MPO concentration was observed. These findings suggest that neutrophils may be involved in the development of BOS.

Mastitis and immunological factors in breast milk of lactating women in Malawi

Although an elevated sodium concentration in human milk is suggested to be an indicator of mastitis, it is unclear whether elevated sodium concentrations are associated with immunological and inflammatory mediators in human milk. We conducted a cross-sectional study to evaluate the relationships between elevated breast milk sodium concentrations and levels of lactoferrin, lysozyme, secretory leukocyte protease inhibitor (SLPI), interleukin-8 (IL-8), and RANTES (regulated on activation normal T cell expressed and secreted) in human milk at 6 weeks postpartum in 96 lactating women in Blantyre, Malawi. Mastitis, as indicated by an elevated breast milk sodium concentration, was present in 15.6% of the women. Women with and without mastitis had respective median levels of other factors as follows: lactoferrin, 1,230 versus 565 mg/liter (P < 0. 0007); lysozyme, 266 versus 274 mg/liter (P = 0.55); SLPI, 76 versus 15 microg/liter, (P < 0.0002); IL-8, 339 versus 25 ng/liter (P < 0. 0001); and RANTES, 82 versus 3 ng/liter (P < 0.0001). Elevated sodium concentrations in breast milk are associated with an increase in levels of some immunological and inflammatory factors in breast milk.

Bikunin, a serine protease inhibitor, is present on the cell boundary of epidermis

Bikunin, which is an inhibitor of serine proteases, is widely distributed in human tissues, including liver, kidney, and mucous membranes of the stomach and colon. The aim of this study was to clarify whether bikunin is expressed in human epidermis and its appendages. Immunoblot analysis using a specific polyclonal antibody to bikunin revealed that a single 43 kDa protein is present in the cell lysate from the human keratinocyte cell line HaCaT. Immunohistochemically, dotted reaction products stained with anti-bikunin antibody were localized on the cell boundary in both basal and spinous cell layers, except on the cell boundary of the basal cells facing the basal membrane. There were no reaction products in the granular-horny cell layers. Reaction products stained with anti-bikunin antibody were also observed on the hair bulb cells and eccrine sweat gland cells, but not on apocrine sweat glands. Also, reaction products were observed on the luminal surface of the renal proximal tubules and in the cytoplasm of these cells. In immunoelectron microscopy, gold particles were observed on the cell membranes close to the desmosomal structures. Reverse transcription-polymerase chain reaction and northern blot analyses showed that mRNA specific for bikunin was expressed in HaCaT cells and human epidermal keratinocytes obtained from suction blisters, and was contained in a commercially available human keratinocyte cDNA preparation. These findings indicate that bikunin is expressed in keratinocytes and may play an important part in regulating keratinocytes in either mitosis or inflammation.

The effect of immediate-hypersensitivity reactions on the level of SLPI, granulocyte elastase, alpha1-antitrypsin, and albumin in nasal secretions, by the method of unilateral antigen challenge

BACKGROUND

The aim of this paper was to investigate the role of SLPI in patients with allergic rhinitis. From this point of view, we also examined leukocyte elastase, alpha1-antitrypsin, and albumin. SLPI is an inhibitor of serine proteases such as leukocyte elastase, cathepsin G, and mast-cell chymase. Since chymase is considered to participate in mast-cell degranulation and histamine release, SLPI might act as a regulator of allergic reactions. Recent interest has been focused on leukocytes and allergy. Since SLPI is a strong inhibitor of leukocyte elastase, we also focused on the function of elastase in allergic rhinitis.

METHODS

We used the method of nasal lavage after unilateral nasal antigen challenge in atopic and healthy subjects. The ELISA quantified SLPI and elastase. Albumin and alpha1-antitrypsin were quantified by electroimmunoassay. Gel filtration was used to separate native SLPI from its complex with elastase.

RESULTS

There was a higher level of SLPI in lavage fluid from healthy subjects than from atopic patients. SLPI was increased on the contralateral side in atopic subjects after allergen challenge. The absence of increase in SLPI on the challenged side may be attributed to the increase in elastase and its binding to SLPI, which might have an effect on the immunoreactivity and interfere with the ELISA. It may then be assumed that there is an augmentation of SLPI on the challenged side as well. No increase was seen in healthy subjects. There was a higher concentration of elastase, alpha1-antitrypsin, and albumin before antigen challenge in atopic patients outside the pollen season than in healthy subjects. As expected, an increase was also seen in the challenged side exclusively in atopic subjects.

CONCLUSIONS

The lower concentration of SLPI in nasal lavage fluid among the atopic patients than the healthy subjects indicates damaged mucosa. Neural reflexes are involved in SLPI release since there was an increase even in the contralateral nostril. A higher level of elastase and albumin before allergen challenge suggests chronic inflammation in nasal mucosa outside the pollen season. Leukocyte recruitment takes place in response to IgE-mediated reactions, which are reflected in an increase in elastase in response to allergen challenge.

Plasminogen activator inhibitor type 2 in human corneal epithelium

PURPOSE

To examine normal human corneal epithelium in vivo and in vitro for expression and status of plasniinogcn activ:ltor inhibitor type 2 (PAI-2).

METHODS

Normal hiuman corneas were prepared for frozen sections and for culture of corneal keratinocytes. PAI-2 was analyzed by immunohistochemistry and western blot analysis uising antibodies that recognize all forms of PAI-2.

RESULTS

In vivo and in vitro, PAI-2 was immunohistochemically localized to the superficial corneal keratinocytes. Immunostaining also revealed the presence of PAI-2 in its relaxed (i.e., cleaved) conformation. In vivo, the staining pattern of the relaxed form was identical with that of total PAI-2, but in vitro the relaxed form was detected in a smaller subpopulation of superficial cells. In vitro, the staining pattern indicated a cytoplasmic localization for PAI-2. Western blot analysis revealed that most of the PAI-2 was cell associated and functionally active.

CONCLUSIONS

The present results are the first to show that PAI-2 is found in normal human corneal epithelium in vivo and in vitro, where it can be considered as a differentiation product. At least in vitro, all detectable PAI-2 is cell associated, with a cytoplasmic distribution. A subpopulation of keratinocytes also contains PAI-2 in its relaxed (i.e., cleaved) conformation. Cleavage by an as yet unidentified cytoplasmic proteinase may constitute a crucial aspect of the function of corneal epithelial PAI-2, which may be relevant to terminal differentiation and death of the corneal keratinocyte.

Comparative study of assays for prostate-specific antigen molecular forms

BACKGROUND

The detection of prostate-specific antigen (PSA) molecular forms such as free PSA and PSA-ACT and the use of PSA molecular ratios, especially the percentage of free to total PSA, have been reported to improve the diagnostic accuracy of prostate cancer in the patients with slightly elevated serum PSA values. However, the correlation among the values of serum free PSA or PSA-ACT obtained in various assays remains unclear.

METHODS

Serum free PSA and PSA-ACT values were detected with the following assays: Hybritech, DPC, EIKEN, Abbott, Roche and Can-Ag for free PSA and Dainippon, Chugai, EIKEN and Bayer for PSA-ACT. The data obtained with each assay were compared with Hybritech (free PSA) and Dainippon (PSA-ACT) as standards.

RESULTS

The free PSA data obtained with the Hybritech, EIKEN, Abbott and Can-Ag kits were similar. The values obtained with the DPC and Roche kits showed a linear regression of y = ax + b with those obtained with the Hybritech, with a b value of zero and an a value of 1.20 and 1.57, respectively. The serum PSA-ACT values detected with the Dainippon and Chugai kits were identical. The equation for converting the data obtained with the EIKEN kits to the Dainippon value was 0.7636 x (EIKEN) + 0.1381.

CONCLUSIONS

Serum free PSA and PSA-ACT values obtained with various assays were not necessarily the same. Some kits for the assay of free PSA and PSA-ACT gave the same serum values. The free PSA values obtained with the other kits could be converted using appropriate equations. The gamma-Sm values showed wide variations and were not considered suitable as a measurement of free PSA.

Protease nexin I expression is up-regulated in human skeletal muscle by injury-related factors

Protease nexin I is a 43-50 kDa glycoprotein capable of inhibiting a number of serine proteases. In cultured differentiated human skeletal muscle (myotubes), we previously found that protease nexin I was localized in patches at their surface where it was active and able to inhibit thrombin. To understand the role of skeletal muscle protease nexin I after injury or in inflammatory conditions where thrombin might be extravasated by blood vessels, we examined the role of inflammatory factors on protease nexin I synthesis and secretion by myotubes in culture. By enzyme-linked immunosorbent assay (ELISA) and Western blotting, we found that this serine protease inhibitor is secreted by cultured human myotubes. Protease nexin I secretion is stimulated by tumor necrosis factor-alpha, transforming growth factor-beta and interleukin-1. Complex formation experiments with labeled thrombin reveal active protease nexin I bound to the surface of the treated cells. Secreted protease nexin I-thrombin complex was enhanced in the presence of transforming growth factor-beta and tumor necrosis factor-alpha. Protease nexin I mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis. Whatever the conditions, no significantly different levels were observed, indicating that the changes in cell and media protease nexin I concentration are elicited at the translational/posttranslational levels. Immunocytochemical studies on human skeletal muscle biopsies of patients suffering from inflammatory myopathies showed an overexpression of protease nexin I together with the above inflammatory factors. These findings suggest that skeletal muscle protease nexin I might play a role after injury or inflammatory pathologies.

Co-localization of tissue factor and tissue factor pathway inhibitor in coronary atherosclerosis

Tissue factor (TF) initiates the extrinsic pathway of blood coagulation by acting as a cofactor for Factor VII. Inhibition of the Factor VIIa-TF complex is mediated by the tissue factor pathway inhibitor (TFPI), which is a serine protease inhibitor with three Kunitz-type domains. The localization of TF and TFPI protein has been examined immunohistochemically in various atherosclerotic lesions of coronary arteries from 22 autopsy cases and their messenger RNA expression has been confirmed by reverse transcription-polymerase chain reaction. Four types of atherosclerotic lesion (types I, II, III, and IV) were classified according to the method described by Stary et al. TF and TFPI were localized in endothelial cells, macrophages, macrophage-derived foam cells, and smooth muscle cells in the intimal lesions, medial smooth muscle cells, and endothelial cells of the microvessels in the adventitia. Immunohistochemical double staining revealed the co-localization of TF and TFPI in the endothelial cells and macrophages in four types of atherosclerotic lesions. In type III and IV lesions, the number of TF- and TFPI-positive cells was increased, accompanied by extracellular localization of TF and TFPI in the lipid core of atherosclerotic plaques. Fibrin deposition was found around TF- and TFPI-positive macrophages and in the lipid core of atherosclerotic plaques. TF and TFPI messenger RNA were detected more frequently in coronary arteries with type III and IV lesions than in those with type I and II lesions. The co-localization of TF and TFPI was demonstrated in various atherosclerotic lesions of coronary arteries and was shown to be intimately related to fibrin deposition in advanced atherosclerotic plaques. The co-localization of TF and TFPI may thus be closely associated with thrombogenicity in atherosclerotic lesions of coronary arteries.

Temporal expression of urokinase plasminogen activator, plasminogen activator inhibitor and gelatinase-B in chronic wound fluid switches from a chronic to acute wound profile with progression to healing

The plasminogen activator/plasmin system is known to initiate a proteolytic cascade resulting in the activation of matrix metalloproteinases in vitro leading to the degradation of extracellular matrix. To investigate whether or not this cascade is present during delayed wound healing and contributes to the pathophysiological basis of impaired healing we examined the temporal expression of urokinase plasminogen activator, plasminogen activator inhibitor-1 and gelatinase-B in fluid collected from chronic venous leg ulcers compared to acute surgical mastectomy wounds. Using a chromogenic substrate assay, levels of active urokinase plasminogen activator in chronic wounds were found to be about five fold higher compared to sera and two fold higher compared to mastectomy wounds. Levels of active plasminogen activator inhibitor-1 in chronic wounds were four times higher than those found in sera and two times higher than those found in mastectomy wound fluid. Using a fibrin overlay system and reverse zymography, we found that when the wound was not healing, the expression of urokinase plasminogen activator in chronic wound fluid was initially detected in the active forms (50 and 33 kDa), but that as the wound healed and decreased in size, was detected as an inhibitor- bound urokinase plasminogen activator-plasminogen activator inhibitor-1 complex ( congruent with 80-116 kDa). When the expression of active urokinase plasminogen activator was highest, no plasminogen activator inhibitor-1 was detectable. In contrast, urokinase plasminogen activator was always detected in the inhibitor bound form as a urokinase plasminogen activator-plasminogen activator inhibitor-1 complex in blood- and plasma-derived serum and mastectomy wound fluid. Plasminogen activator inhibitor-1 was detected in blood-derived serum and mastectomy wound fluid but not in plasma derived serum. Expression of matrix metalloproteinase-9 in chronic wound fluids, analyzed by gelatin zymography, showed that when urokinase plasminogen activator was detected in the active forms, matrix metalloproteinase-9 was overexpressed by approximately twice that found in mastectomy wounds and approximately 30 times that detected in blood-derived sera. When urokinase plasminogen activator appeared almost entirely as an enzyme- inhibitor complex, the level of expression of matrix metalloproteinase-9 was similar to that seen in mastectomy wound fluid. We conclude that the switch in urokinase plasminogen activator expression from an active to inhibitor bound form correlates with the decrease seen in matrix metalloproteinase-9 expression suggesting the presence of a proteolytic cascade initiated by the plasminogen activator/plasmin system during wound healing leading to the activation of matrix metalloproteinase-9. In addition, expression of urokinase plasminogen activator and matrix metalloproteinase-9 appear to be useful biomarkers to determine clinical wound healing status.

Tobacco smoking and gingival neutrophil activity in young adults

The influence of smoking on the activity of the gingival neutrophils in young periodontally healthy adults was studied. The neutrophil activity was measured in terms of the gingival crevicular fluid (GCF) levels of elastase, lactoferrin (LF), alpha-1-antitrypsin (alpha-1-AT), alpha-2-macroglobulin (alpha-2 MG) and protein. 30 healthy dental students with no clinical signs of periodontitis, 15 smokers (8 women and 7 men) aged 20-32 years and 15 non-smokers (7 women and 8 men) aged 22-31 years, volunteered to take part in the investigation. The gingival inflammation was registered at 6 sites and the GCF volume was collected from the same sites. The GCF volume was measured with a Periotron 6000. The elastase activity was measured with a chromogenic low molecular substrate and the LF alpha-1-AT, alpha-2-MG levels were determined with ELISA. The protein concentration was measured by the Bradford method. The results showed a statistically significantly lower GCF volume among smokers as compared to non-smokers. No significant difference was found in the elastase activity/microl of the GCF supernatant between smokers and non-smokers but there was a large inter-individual variation. Nor did the concentrations of LF, alpha-1-AT, alpha-2-MG and protein per microl GCF differ significantly between the 2 groups. The results suggest that the influence of smoking on the examined factors associated with neutrophil activity is limited under healthy or slightly inflamed gingival conditions giving only small amounts of GCF.

Neutrophil response and microbiological findings around teeth and dental implants

The aim of this study was to compare the neutrophil response, measured as both functional and antigenic elastase, around teeth and titanium implants and to relate these findings to the microbiota. The 31 patients included in the study had been treated successfully for total or partial edentulism with titanium implants. Crevicular fluid and microbiological samples were taken from 3 sites: 1) crevices around teeth and 2) implants in 16 partially edentulous patients and 3) crevices around implants in 15 edentulous patients. All sites sampled showed similar degrees of inflammation assessed by gingival index and total protein concentration. The samples were analyzed for elastase activity and immunoreactive elastase. The elastase activity was significantly higher in crevices surrounding implants in partially edentulous patients compared with implants in edentulous patients. The antigenic elastase showed no difference among the 3 sites. Gram-positive cocci were the main bacterial species in all 3 groups. Edentulous patients tended to have lower frequency of black pigmenting anaerobes. No correlation of analyzed bacteria and elastase activity was found between the 3 sites. This study indicates that, despite a similar appearance of clinical parameters and absence of significant differences in the microbiota, the inflammation around implants in partially edentulous patients induces a stronger neutrophil response than does the inflammation around implants in edentulous patients.

Improved hepatic and pancreatic localisation of the equine alpha-1-proteinase inhibitor family of serpins using an antigen enhancement technique and a monoclonal antibody

Equine alpha-1-proteinase inhibitor (API) consists of three, occasionally four, serum glycoproteins. This study investigated the immunohistochemical localisation of equine API in paraformaldehyde fixed, paraffin embedded equine tissue samples of liver, lung, stomach, pancreas, jejunum and colon in five horses using affinity purified sheep polyclonal and protein A purified mouse monoclonal antibodies, whose specificities were verified by Western blotting. Exposing tissue sections to boiling citrate buffer greatly enhanced antigen recovery and improved immunostaining with both antibodies, resulting in discovery of novel tissue distribution patterns for the horse. In the horses studied, all hepatocytes showed some degree of cytoplasmic staining, many having perinuclear intense granular inclusions. This finding is contrary to findings in human studies where hepatocytes of Pi MM phenotype have proven difficult to stain for human API, despite evidence at the molecular level suggesting hepatocytes as the major source of serum API. This discrepancy may be due to the use of different tissue fixation and antigen recovery techniques. In all other tissues examined, the distribution of equine API was similar to human studies.

Alpha-1-antichymotrypsin immunoreactivity in papillary carcinoma of the thyroid gland

AIM

Papillary thyroid carcinoma (PTC) is the most common malignant tumour of the thyroid gland. The immunohistochemical profile of PTC is characterized by immunoreactivity of tumour cells for cytokeratins, thyroglobulin, vimentin, EMA and S100 protein. Recently, the presence of a serum protease inhibitor, alpha-1-antitrypsin (A1AT), has been demonstrated in tumour cells of PTC. The aim of our study was to test immunoreactivity of PTC for another inhibitor of proteases, alpha-1-antichymotrypsin (A1ACT).

METHODS AND RESULTS

Serial paraffin sections of nine consecutive cases of PTC were tested with anti-A1AT and anti-A1ACT antibodies. No immunoreactivity for A1AT and A1ACT was found in the normal thyroid tissue surrounding each tumour. In seven out of nine cases, tumour cells of PTC showed cytoplasmic immunoreactivity for A1ACT. In two cases, A1ACT was detected even in the nuclei. Immunoreactivity for A1AT was found only in three cases. Two cases of PTC showed no staining for both A1ACT and A1AT. No significant correlation of A1ACT staining was found with various prognostic indices (age of patients, histological pattern, tumour size, presence of regional lymph node metastases). The two cases showing a lack of staining for both A1ACT and A1AT showed a more aggressive clinical behaviour.

CONCLUSIONS

Our preliminary study shows that A1ACT is expressed by tumour cells in a large proportion of papillary carcinomas of the thyroid gland. Its significance remains, to the best of our knowledge, still unknown. The observation of a more aggressive behaviour in the two cases characterized by the absence of immunoreactivity for both A1ACT and A1AT suggests that the presence or absence of protease inhibitors could play a role in controlling tumour progression in PTC.

Presence of tissue factor pathway inhibitor in human atherosclerotic plaques is associated with reduced tissue factor activity

BACKGROUND

Plaque disruption and exposure of subendothelial procoagulants such as tissue factor (TF) to circulating factor VII/VIIa (FVII/VIIa) lead to intravascular thrombosis. Tissue factor pathway inhibitor (TFPI) is an endogenous inhibitor of TF-induced coagulation that binds to factor Xa and the TF-FVIIa catalytic complex in a two-step process. The aim of this study was to determine the expression of TFPI within human atherosclerotic plaque and its role in modulation of TF activity.

METHODS AND RESULTS

We measured the level of TFPI antigen in human carotid plaque and determined the relationship between TFPI and TF activity within plaque. Furthermore, we examined the biological activity and immunolocalization patterns of TFPI within carotid plaque. TFPI was detectable (TFPI+ group) in 22 of 34 specimens (mean+/-SEM, 404. 4+/-91.8 pg/mg) and undetectable (TFPI- group) in 12 of 34 specimens. In the TFPI- group, normalized TF activity was significantly greater than that in the TFPI+ group (0.28+/-0.04 vs 0.14+/-0.02 U/pg, P=0.002). Furthermore, neutralization of TFPI activity using a polyclonal antibody resulted in an 8-fold increase in TF activity in the TFPI+ group (P=0.001) but had no effect in the TFPI- group. Immunostaining for TFPI showed localization to endothelial cells, vascular smooth muscle cells within the fibrous cap region of the plaque, and macrophages within the shoulder region of the plaque.

CONCLUSIONS

Taken together, these data suggest that biologically active TFPI is present within human atherosclerotic plaque and is associated with attenuated TF activity.

Inter-alpha-inhibitor in calcium stones

1. A broad spectrum of proteins has been detected within calcium stones. A newcomer to the field of urolithiasis is the blood protein inter-alpha-inhibitor. Inter-alpha-inhibitor comprises three protein chains linked by chondroitin sulphate: two heavy chains, H1 (65 kDa) and H2 (70 kDa) and a light chain (approx. 30 kDa) most commonly known as bikunin. The physiological function of the two heavy chains is unknown; nor has their presence been reported in urine. However, bikunin has been implicated in various renal diseases, including urolithiasis. 2. This study was undertaken to determine which chains of inter-alpha-inhibitor are actually present in calcium kidney stones. Organic extracts were obtained from 10 calcium stones and analysed by SDS/PAGE and Western blotting. The H1 and H2 chains of inter-alpha-inhibitor were detected in 9 of the 10 stones, but only one stone contained a protein with a molecular mass close to that of bikunin (30-35 kDa). 3. These results demonstrate for the first time that H1 and H2 are present in stones and show that the bikunin chain of inter-alpha-inhibitor may not be the only part of the molecule implicated in stone formation.

Cornified cell envelope assembly: a model based on electron microscopic determinations of thickness and projected density

In stratifying squamous epithelia, the cornified cell envelope (CE), a peripheral layer of crosslinked protein, is assembled sequentially from precursor proteins initially dispersed in the cytoplasm. Its major component is loricrin (37 kDa in mouse), which contributes from approx. 60% to &gt;80% of the protein mass in different tissues. Despite its importance to the mechanical resilience and impenetrability of these tissues, detailed information has not been obtained on CE structure, even on such basic properties as its thickness or uniformity across a given CE or from tissue to tissue. To address this issue, we have studied CEs isolated from three murine epithelia, namely epidermis, forestomach and footpad, by electron microscopy of metal-shadowed specimens and scanning transmission electron microscopy (STEM) of unstained specimens. The former data reveal that the cytoplasmic surface is smoothly textured whereas the extracellular surface is corrugated, and that the average thickness is 15.3+/−1.2 nm, and strikingly uniform. Measurements of mass-per-unit-area from the STEM images yielded values of approx. 7.0+/−0.8 kDa/nm2, which were remarkably consistent over all three tissues. These data imply that the mature CE has a uniquely defined thickness. To explain its uniformity, we postulate that loricrin forms a molecular monolayer, not a variable number of multiple layers. In this scenario, the packing density is one loricrin monomer per 7 nm2, and loricrin should have an elongated shape, 2.5-3.0 nm wide by approx. 11 nm long. Moreover, we anticipate that any inter-tissue variations in the mechanical properties of CEs should depend more on protein composition and cross-linking pattern than on the thickness of the protein layer deposited.

Identification, origins and the diurnal role of the principal serine protease inhibitors in human tear fluid

PURPOSE

Previous work identified polymorphonuclear leukocyte (PMN) elastase as the major caseinolytic entity in tears collected after overnight eye closure. This study was designed to identify the principal serine protease inhibitors (serpins) in tears and to determine their function in the regulation of PMN cell proteases on eye closure.

METHODS

Reflex and closed eye tear samples were collected by microcapillary tube and centrifuged. After reflex and closed eye supernatants (R and C) were fractionated by HPLC, samples were subjected to casein zymography and reverse zymography. Western blots were utilized to screen tears and HPLC fractions for elastase, cathepsin G and proteinase-3 and to obtain semi-quantitative data on alpha 1-protease inhibitor (alp1), alpha 1-antichymotrypsin (alpha 1-Achy), secretory leukocyte protease inhibitor (SLPI), elafin and alpha 2-macroglobulin (alpha 2-M) as well as associated complexes and products. To confirm specificity of reactivity, samples were immunoprecipitated for a given protease or serpin and screened for the coprecipitation of interacting species.

RESULTS

Although R fluid contains no caseinolytic activity, it contains low levels of serpin-like activity principally in the form of SLPI (5-10 ng/microliter). Lesser amounts of alpha 2-M, alpha 1-Achy and alp1 (approximately < 1-3 ng/microliter) are also evident. C fluid is associated with very high levels of PMN cell proteases along with a approximately 5-20-fold increase in the concentrations of all of the above inhibitors. Trace levels of elafin were also detected. The concentrations of rapid reacting inhibitors exceeded that of proteases, with SLPI, alpha 1-Achy and alp1 being the principal functional entities. In atypical samples, complexes of elastase and alpha 2-M were also encountered.

CONCLUSIONS

SLPI, a known antimicrobial agent and an elastase and cathepsin G inhibitor, is the principal serpin in R fluid. C fluid is associated with a marked increase in the concentrations of an array of rapid reacting serpins capable of inhibiting all known PMN cell serine proteases. In the normal closed eye, the concentration of rapid reacting inhibitors always exceeds that of proteases with C fluid also containing a functional reserve of the slow reacting inhibitor alpha 2-M.

[Homocysteine, 5,10-methylenetetrahydrofolate reductase and deep venous thrombosis. Survey of 120 patients in internal medicine]

BACKGROUND

In the last few years, the association of deep vein thrombosis with frequent biological risk factors and genetic polymorphisms has significantly modified the field of venous thrombosis. In this study, we measured plasma homocysteine levels and tested the C677T methylenetetrahydrofolate reductase (MTHFR) mutation.

PATIENTS AND METHODS

Plasma homocysteine levels and test for C677T MTHFR mutation were performed in 120 consecutive patients with objectively diagnosed deep vein thrombosis, and in 120 controls.

RESULTS

We found a strong association between hyperhomocysteinemia and thrombosis (odd ratio: 2.43 IC 95% [1.27-4.7]). Conversely the C677T MTHFR gene polymorphism is only associated with hyperhomocysteinemia but not associated with thrombosis.

CONCLUSION

This is a preliminary study to the ongoing international multicentric study of SNFMI (Société nationale française de m0+edecine interne) concerning hyperhomocysteinemia and venous thrombosis.

Immunohistochemical demonstration of the plasminogen activator system in human gingival tissues and gingival fibroblasts

The relative distribution of urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and plasminogen activator inhibitor-2 (PAI-2) was studied in cultured human gingival fibroblasts, healthy gingival tissues and inflamed gingival tissues by immunohistochemistry. In cultured gingival fibroblasts t-PA, u-PA and PAI-1 were expressed in cytoplasm; u-PA and PAI-1 were more intensely stained than t-PA; PAI-2 was not detectable in gingival fibroblasts. Following interleukin 1 beta (IL-1 beta) stimulation, the intensity of intracellular staining for t-PA was increased and a number of cells staining strongly for PAI-2 were seen; no difference in the intensity of immunostaining level was noted for the expression of u-PA and PAI-1 between IL-1 beta stimulated cells and unstimulated cells. In healthy gingival tissues, u-PA and PAI-1 displayed a wide distribution throughout all the connective tissue and epithelium; t-PA localized mainly in the connective tissue while PAI-2 showed little association with the connective tissue but did faintly stain in the epithelial layer. In inflamed gingival tissues, staining for t-PA was significantly increased in the extracellular matrix of the connective tissue, whereas staining for u-PA, PAI-1 and PAI-2 was found to be slightly increased, but no significant difference was noted for staining when compared with the healthy gingival tissues. A granular distribution of t-PA, u-PA, PAI-1 and PAI-2 was noted around areas of inflammatory cell infiltration. These immunohistochemical findings indicate that the plasminogen activator system produced by fibroblasts may be influenced by the presence of the inflammatory mediator IL-1 beta. In addition, the significant increase of t-PA in inflamed connective tissue and the wide expression of these components around inflamed cells may contribute to connective tissue degradation and may relate to the migration and localization of monocytes/macrophages in inflamed tissue.

Quantification and characterization of human endothelial cell-derived tissue factor pathway inhibitor-2

Tissue factor pathway inhibitor-2 (TFPI-2), also known as placental protein 5, is a serine protease inhibitor consisting of three tandemly-arranged Kunitz-type protease inhibitor domains. While TFPI-2 is a potent inhibitor of trypsin, plasmin, kallikrein, and factor XIa in the test tube, the function of this inhibitor in vivo remains unclear. In the present study, we investigated the synthesis and secretion of TFPI-2 by cultured endothelial cells derived from human umbilical vein, aorta, saphenous vein, and dermal microvessels to gain insight into its biological function. While all endothelial cells examined synthesized and secreted TFPI-2, dermal microvascular endothelial cells synthesized threefold to sevenfold higher levels of TFPI-2. Approximately 60% to 90% of the TFPI-2 secreted by endothelial cells was directed to the subendothelial extracellular matrix (ECM). When cultured human umbilical vein endothelial cells were stimulated with inflammatory mediators such as phorbol 12-myristate,13-acetate; endotoxin; and tumor necrosis factor-alpha, TFPI-2 synthesis by these cells increased twofold to 14-fold. Recombinant TFPI-2 bound to dermal microvascular endothelial cell monolayers and its ECM in a specific, dose-dependent, and saturable manner with Kd values of 21 and 24 nmol/L, respectively. TFPI-2 interacted with 4.5 X 10(10) sites/cm2 (3 X 10[5] sites/cell) and 2.3 X 10(11) sites/cm2 on endothelial cells and ECM, respectively. In the presence of rabbit anti-TFPI-2 IgG, but not preimmune IgG, endothelial cells dissociated from the culture flask in a time- and IgG concentration-dependent manner. Our findings provide evidence that endothelial cell-derived TFPI-2 is primarily secreted into the abluminal space and presumably plays an important role in maintaining the integrity of the ECM essential for cell attachment.

Markers for macrophage and osteoclast lineages in giant cell lesions of the oral cavity

PURPOSE

Giant cell lesions of the oral cavity are a well recognized entity. However, the histogenesis of these lesions is still the subject of controversy, with support for both histiocyte/macrophage and osteoclast origins being found in the literature. This study evaluated a set of peripheral giant cell lesions (PGCLs) and central giant cell lesions (CGCLs) for characteristics of both cell types to address this dilemma.

MATERIALS AND METHODS

Detection of histiocyte/macrophage characteristics was accomplished immunohistochemically by evaluating for markers specific for this cell type, namely alpha-1 -antichymotrypsin (1 -ACT) and factor XIIIa antibodies. Detection of osteoclast characteristics made use of the fact that osteoclasts possess a unique enzyme, tartrate-resistant acid phosphatase, which can be appreciated by histochemical procedures.

RESULTS

A large percentage of the multinucleated cells stained with the 1-ACT (38.08% in PGCLs and 15.84% in CGCLs), while only isolated cells stained for factor XIIIa (1.20% PGCLs, 0.99% CGCLs). Isolated stromal cells also were stained. Virtually all multinucleated cells reacted with the tartrate-resistant acid phosphatase stain (99.26% PGCLs, 98.34% CGCLs), as did a number of the mononuclear stromal cells.

CONCLUSIONS

This study supports the contention that GCLs of the oral cavity may arise from precursor cells related to the granulocyte/macrophage line, and may originate from mononuclear cells that express markers for both macrophages and osteoclasts.