A Modified Glycosaminoglycan, GM-0111, Inhibits Molecular Signaling Involved in Periodontitis

Background

Periodontitis is characterized by microbial infection, inflammation, tissue breakdown, and accelerated loss of alveolar bone matrix. Treatment targeting these multiple stages of the disease provides ways to treat or prevent periodontitis. Certain glycosaminoglycans (GAGs) block multiple inflammatory mediators as well as suppress bacterial growth, suggesting that these GAGs may be exploited as a therapeutic for periodontitis.

Methods

We investigated the effects of a synthetic GAG, GM-0111, on various molecular events associated with periodontitis: growth of Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) pathogenic bacteria associated with periodontitis; activation of pro-inflammatory signaling through TLR2 and TLR4 in mouse macrophage RAW 264.7 cells and heterologously expressed HEK 293 cells; osteoclast formation and bone matrix resorption in cultured mouse pre-osteoclasts.

Results

(1) GM-0111 suppressed the growth of P. gingivalis and A. actinomycetemcomitans even at 1% (w/v) solution. The antibacterial effects of GM-0111 were stronger than hyaluronic acid (HA) or xylitol in P. gingivalis at all concentrations and comparable to xylitol in A. actinomycetemcomitans at ≥2% (w/v) solution. We also observed that GM-0111 suppressed biofilm formation of P. gingivalis and these effects were much stronger than HA. (2) GM-0111 inhibited TLR-mediated pro-inflammatory cellular signaling both in macrophage and HEK 293 cells with higher selectivity for TLR2 than TLR4 (IC₅₀ of 1–10 ng/mL vs. > 100 μg/mL, respectively). (3) GM-0111 blocked RANKL-induced osteoclast formation (as low as 300 ng/mL) and bone matrix resorption. While GM-0111 showed high affinity binding to RANKL, it did not interfere with RANKL/RANK/NF-κB signaling, suggesting that GM-0111 inhibits osteoclast formation by a RANKL-RANK-independent mechanism.

Conclusions

We report that GM-0111 inhibits multiple molecular events involved in periodontitis, spanning from the early pro-inflammatory TLR signaling, to pathways activated at the later stage component of bone loss.

2-O, 3-O-desulfated heparin inhibits neutrophil elastase-induced HMGB-1 secretion and airway inflammation

Neutrophil elastase (NE) is a major inflammatory mediator in cystic fibrosis (CF) that is a robust predictor of lung disease progression. NE directly causes airway injury via protease activity, and propagates persistent neutrophilic inflammation by up-regulation of neutrophil chemokine expression. Despite its key role in the pathogenesis of CF lung disease, there are currently no effective antiprotease therapies available to patients with CF. Although heparin is an effective antiprotease and anti-inflammatory agent, its anticoagulant activity prohibits its use in CF, due to risk of pulmonary hemorrhage. In this report, we demonstrate the efficacy of a 2-O, 3-O-desulfated heparin (ODSH), a modified heparin with minimal anticoagulant activity, to inhibit NE activity and to block NE-induced airway inflammation. Using an established murine model of intratracheal NE-induced airway inflammation, we tested the efficacy of intratracheal ODSH to block NE-generated neutrophil chemoattractants and NE-triggered airway neutrophilic inflammation. ODSH inhibited NE-induced keratinocyte-derived chemoattractant and high-mobility group box 1 release in bronchoalveolar lavage. ODSH also blocked NE-stimulated high-mobility group box 1 release from murine macrophages in vitro, and inhibited NE activity in functional assays consistent with prior reports of antiprotease activity. In summary, this report suggests that ODSH is a promising antiprotease and anti-inflammatory agent that may be useful as an airway therapy in CF.

Partially-desulfated heparin improves survival in Pseudomonas pneumonia by enhancing bacterial clearance and ameliorating lung injury

Nosocomial pneumonia (NP, or hospital-acquired pneumonia) is associated with infections originating from hospital-borne pathogens. Persistent microbial presence and acute lung injury are common features of these infections, contributing to the high mortality rates and excessive financial burden for these patients. Pseudomonas aeruginosa (PA), a gram-negative opportunistic pathogen, is one of the prominent pathogens associated with NP. PA pneumonia is characterized by excessive secretion of inflammatory cytokines, neutrophil infiltration, and subsequent lung damage. The persistent presence of PA along with overwhelming inflammatory response is suggestive of impairment in innate immunity. High mobility group box 1 (HMGB1), a recently discovered potent pro-inflammatory cytokine, plays an important role in PA lung infections by compromising innate immunity via impairing phagocyte function through toll-like receptors (TLR) TLR2 and TLR4. ODSH (2-O, 3-O-desulfated heparin), a heparin derivative with significant anti-inflammatory properties but minimal anti-coagulatory effects, has been shown to reduce neutrophilic lung injury in the absence of active microbial infections. This study examined the effects of ODSH on PA pneumonia. This study demonstrates that ODSH not only reduced PA-induced lung injury, but also significantly increased bacterial clearance. The ameliorated lung injury, together with the increased bacterial clearance, resulted in marked improvement in the survival of these animals. The resulting attenuation in lung injury and improvement in bacterial clearance were associated with decreased levels of airway HMGB1. Furthermore, binding of HMGB1 to its receptors TLR2 and TLR4 was blunted in the presence of ODSH. These data suggest that ODSH provides a potential novel approach in the adjunctive treatment of PA pneumonia.

Novel sulfated polysaccharides disrupt cathelicidins, inhibit RAGE and reduce cutaneous inflammation in a mouse model of rosacea

BACKGROUND

Rosacea is a common disfiguring skin disease of primarily Caucasians characterized by central erythema of the face, with telangiectatic blood vessels, papules and pustules, and can produce skin thickening, especially on the nose of men, creating rhinophyma. Rosacea can also produce dry, itchy eyes with irritation of the lids, keratitis and corneal scarring. The cause of rosacea has been proposed as over-production of the cationic cathelicidin peptide LL-37.

METHODOLOGY/PRINCIPAL FINDINGS

We tested a new class of non-anticoagulant sulfated anionic polysaccharides, semi-synthetic glycosaminoglycan ethers (SAGEs) on key elements of the pathogenic pathway leading to rosacea. SAGEs were anti-inflammatory at ng/ml, including inhibition of polymorphonuclear leukocyte (PMN) proteases, P-selectin, and interaction of the receptor for advanced glycation end-products (RAGE) with four representative ligands. SAGEs bound LL-37 and inhibited interleukin-8 production induced by LL-37 in cultured human keratinocytes. When mixed with LL-37 before injection, SAGEs prevented the erythema and PMN infiltration produced by direct intradermal injection of LL-37 into mouse skin. Topical application of a 1% (w/w) SAGE emollient to overlying injected skin also reduced erythema and PMN infiltration from intradermal LL-37.

CONCLUSIONS

Anionic polysaccharides, exemplified by SAGEs, offer potential as novel mechanism-based therapies for rosacea and by extension other LL-37-mediated and RAGE-ligand driven skin diseases.

Low anticoagulant heparin targets multiple sites of inflammation, suppresses heparin-induced thrombocytopenia, and inhibits interaction of RAGE with its ligands

While heparin has been used almost exclusively as a blood anticoagulant, important literature demonstrates that it also has broad anti-inflammatory activity. Herein, using low anti-coagulant 2-O,3-O-desulfated heparin (ODSH), we demonstrate that most of the anti-inflammatory pharmacology of heparin is unrelated to anticoagulant activity. ODSH has low affinity for anti-thrombin III, low anti-Xa, and anti-IIa anticoagulant activities and does not activate Hageman factor (factor XII). Unlike heparin, ODSH does not interact with heparin-platelet factor-4 antibodies present in patients with heparin-induced thrombocytopenia and even suppresses platelet activation in the presence of activating concentrations of heparin. Like heparin, ODSH inhibits complement activation, binding to the leukocyte adhesion molecule P-selectin, and the leukocyte cationic granular proteins azurocidin, human leukocyte elastase, and cathepsin G. In addition, ODSH and heparin disrupt Mac-1 (CD11b/CD18)-mediated leukocyte adhesion to the receptor for advanced glycation end products (RAGE) and inhibit ligation of RAGE by its many proinflammatory ligands, including the advanced glycation end-product carboxymethyl lysine-bovine serum albumin, the nuclear protein high mobility group box protein-1 (HMGB-1), and S100 calgranulins. In mice, ODSH is more effective than heparin in reducing selectin-mediated lung metastasis from melanoma and inhibits RAGE-mediated airway inflammation from intratracheal HMGB-1. In humans, 50% inhibitory concentrations of ODSH for these anti-inflammatory activities can be achieved in the blood without anticoagulation. These results demonstrate that the anticoagulant activity of heparin is distinct from its anti-inflammatory actions and indicate that 2-O and 3-O sulfate groups can be removed to reduce anticoagulant activity of heparin without impairing its anti-inflammatory pharmacology.

Nonanticoagulant heparin reduces myocyte Na+ and Ca2+ loading during simulated ischemia and decreases reperfusion injury

Heparin desulfated at the 2-O and 3-O positions (ODSH) decreases canine myocardial reperfusion injury. We hypothesized that this occurs from effects on ion channels rather than solely from anti-inflammatory activities, as previously proposed. We studied closed-chest pigs with balloon left anterior descending coronary artery occlusion (75-min) and reperfusion (3-h). ODSH effects on [Na(+)](i) (Na Green) and [Ca(2+)](i) (Fluo-3) were measured by flow cytometry in rabbit ventricular myocytes after 45-min of simulated ischemia [metabolic inhibition with 2 mM cyanide, 0 glucose, 37 degrees C, pacing at 0.5 Hz; i.e., pacing-metabolic inhibition (PMI)]. Na(+)/Ca(2+) exchange (NCX) activity and Na(+) channel function were assessed by voltage clamping. ODSH (15 mg/kg) 5 min before reperfusion significantly decreased myocardial necrosis, but neutrophil influx into reperfused myocardium was not consistently reduced. ODSH (100 microg/ml) reduced [Na(+)](i) and [Ca(2+)](i) during PMI. The NCX inhibitor KB-R7943 (10 microM) or the late Na(+) current (I(Na-L)) inhibitor ranolazine (10 microM) reduced [Ca(2+)](i) during PMI and prevented effects of ODSH on Ca(2+) loading. ODSH also reduced the increase in Na(+) loading in paced myocytes caused by 10 nM sea anemone toxin II, a selective activator of I(Na-L). ODSH directly stimulated NCX and reduced I(Na-L). These results suggest that in the intact heart ODSH reduces Na(+) influx during early reperfusion, when I(Na-L) is activated by a burst of reactive oxygen production. This reduces Na(+) overload and thus Ca(2+) influx via NCX. Stimulation of Ca(2+) extrusion via NCX later after reperfusion may also reduce myocyte Ca(2+) loading and decrease infarct size.

Characterization of bleomycin lung injury by nuclear magnetic resonance: correlation between NMR relaxation times and lung water and collagen content

The response of the NMR relaxation times (T(1), CPMG T(2), and Hahn T(2)) to bleomycin-induced lung injury was studied in excised, unperfused rat lungs. NMR, histologic, and biochemical (collagen content measurement) analyses were performed 1, 2, 4, and 8 weeks after intratracheal instillation of saline (control lungs) or 10 U/kg bleomycin sulfate. The control lungs showed no important NMR, water content, histologic, or collagen content changes. The spin-spin relaxation times for the fast and intermediate components of the CPMG decay (T(2f) and T(2i), respectively) increased 1 week after bleomycin injury (acute inflammatory stage) and then progressively decreased during the following 2-8 weeks (i.e., with the development of the chronic, fibrotic stage of the injury). The slow component (T(2s)) showed no significant changes. The response of T(1) and the slow component of the Hahn T(2) was, on the whole, similar to that of CPMG T(2f) and T(2i). T(1) changes were very small. Lung water content increased 1 week after injury. Histologic and biochemical assessment of collagen showed that collagen content was close to control at 1 week, but markedly increased at 2, 4, and 8 weeks. T(1) and T(2) data were directly correlated with lung water content and inversely correlated with collagen content. Our results indicate that NMR relaxation time measurements (particularly T(2)) reflect the structural changes associated with bleomycin injury. The prolonged T(2) relaxation times observed in the acute stage are related to the presence of edema, whereas the subsequent decrease in these values marks the stage of the collagen deposition (fibrotic stage). CPMG-T(2) and Hahn-T(2) measurements can be valuable as a potentially noninvasive method for characterizing bleomycin-induced lung injury and pathologically related lung disorders.

Cloning and characterization of the cDNA and gene for human epitheliasin

Previously, we reported cloning and characterization of the mouse gene, epitheliasin. In the present work we cloned the cDNA of the full-length human orthologue and characterized its gene including 2 kb of 5' flanking sequence. Analysis of epitheliasin gene expression in adult tissues shows that it is expressed as 3.4 kb and 2 kb transcripts. The major 3.4 kb transcript is observed in the following order: prostate > colon > small intestine > pancreas > kidney > lung > liver. Epitheliasin transcripts in fetal tissues are observed only in kidney and lung. In situ hybridization analysis of tissues revealed that epitheliasin was preferentially expressed in epithelial cells. The gene consists of 14 exons and 13 introns based on comparison with its cDNA sequence. In the 5' flanking region, we identified two transcription start sites and three CpG islands encompassing a number of potential regulatory elements including SP1, SREBP, GRE/PRE and ERE. The region upstream of the transcription sites lacks a TATA box but contains an initiator-like element as well as a downstream promoter-like element. In vitro experiments with lymph node carcinoma of prostate (LNCaP) cells revealed that the epitheliasin gene was induced by androgens and the induction was not blocked by cycloheximide indicating that the induction required no intermediate protein factors. Immunoprecipitation analysis showed that androgens strongly increased epitheliasin protein levels.

Synthesis of pyrrolo[2,1-c[1,4]benzodiazepines via reductive cyclization of omega-azido carbonyl compounds by TMSI: an efficient preparation of antibiotic DC-81 and its dimers

Azido carbonyl compounds on reaction with trimethylsilyl iodide (in situ prepared from TMSCl/NaI) led to the formation of diazepine imines in good yields under mild conditions. This methodology has been applied to the parent unsubstituted pyrrolobenzodiazepine, the natural product DC-81 and its dimers.

Cloning, genomic organization, chromosomal assignment and expression of a novel mosaic serine proteinase: epitheliasin

We report the isolation of a cDNA encoding a novel murine serine proteinase, epitheliasin. The cDNA spans 1753 bp and encodes a mosaic protein with a calculated molecular mass of 53529 Da. Its domains include a cytoplasmic tail, a type II transmembrane domain, a low-density lipoprotein receptor class A domain, a cysteine rich scavenger receptor-like domain and a serine proteinase domain. The proteinase portion domain shows 46-53% identity with mouse neurotrypsin, acrosin, hepsin and enteropeptidase. The gene, located in the telomeric region in the long arm of mouse chromosome 16, consists of 14 exons and 13 introns and spans approximately 18 kb. Epitheliasin is expressed primarily in the apical surfaces of renal tubular and airway epithelial cells.

Novel antidiabetic and hypolipidemic agents. 3. Benzofuran-containing thiazolidinediones

Several thiazolidinedione derivatives having 5-hydroxy-2,3-dihydro-2, 2,4,6,7-pentamethylbenzofuran moieties and their 5-benzyloxy derivatives and 5-hydroxy-2,4,6,7-tetramethylbenzofuran moieties were synthesized and evaluated in db/db mice. Insertion of an N-Me group into the linker between thiazolidinedione and substituted benzofuran pharmacophores showed considerable improvement in their euglycemic activity. Further improvement has been observed when a pyrrolidine moiety is introduced in the structure to give 5-[4-[N-[3(R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6, 7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidin-2- ylmethoxy]pheny lene]thiazolidine-2,4-dione (21a). At a 100 mg/kg/day dose of the maleate salt, compound 21a reduced the plasma glucose and triglyceride to the level of lean littermate, i.e. 8 +/- 1 mM, and is the most potent and efficacious compound reported in this series.

Facile and improved synthesis of 4 beta-aminopodophyllotoxin congeners

An efficient synthesis of 4 beta-aminopodophyllotoxin from 4 beta-bromopodophyllotoxin using ammonia, and also a facile synthesis of 4 beta-amino-4'-O-demethylpodophyllotoxin from 4 beta-azidopodophyllotoxin by simultaneous azido reduction and selective demethylation at 4'-position employing chlorotrimethylsilane and sodium iodide, has been described. These are potential precursors for the various 4 beta-amino analogs of podophyllotoxin possessing DNA topoisomerase II inhibition activity.

Induction of urokinase-type plasminogen activator receptor by IL-1 beta

Extensive tissue remodeling occurs in survivors of acute lung injury, leading to nearly normal histology and physiology in the majority of individuals, whereas others suffer significant impairment due to the development of pulmonary fibrosis. Alveolar epithelial cells play a central role in the repair process. They are strategically located to directly participate in the solubilization of intraalveolar fibrin deposits, and have the capacity to promote fibrinolysis. We have previously reported that interleukin-1 beta (IL-1 beta), an important inflammatory mediator in acute lung injury, upregulates urokinase-type plasminogen activator expression by human A549 cells (1). In this work, we show that IL-1 beta increases cell-surface plasmin generation, mediated in part by increased expression of urokinase receptor (u-PAR). Northern blot analyses demonstrated that IL-1 beta rapidly induces accumulation of u-PAR messenger RNA (mRNA) in a dose-dependent fashion, and that this effect is blocked by actinomycin. The IL-1 beta-mediated increase in u-PAR mRNA is inhibited by: (1) the relatively specific protein kinase C (PKC) inhibitors 1-(5-isoquinoline sulfonyl)-2-methylpiperazine (H7) and calphostin C; and (2) prolonged pretreatment of cells with phorbol myristate acetate (PMA), suggesting that PKC is an important component of the signaling pathway. Okadaic acid, an inhibitor of serine/threonine phosphatases, markedly potentiates the effect of IL-1 beta on u-PAR mRNA levels. In contrast, dexamethasone, in concentrations as low as 10(-8) M, completely blocks the IL-1 beta-mediated increase in u-PAR mRNA. Half-life experiments show that dexamethasone has no effect on u-PAR mRNA stability. Aldosterone, at concentrations in which it binds primarily to the mineralocorticoid receptor, has no effect on u-PAR expression, suggesting that the glucocorticoid effect is due to a transrepressive mechanism. In summary, IL-1 beta increases cell-surface plasmin generation in A549 cells by coordinately upregulating urokinase and u-PAR expression. Transcriptional activation of the u-PAR gene involves PKC-dependent mechanisms, and glucocorticoid suppression is probably due to interactions between the glucocorticoid receptor and another transcriptional activating system such as activator protein-1 (AP-1) and/or nuclear factor-kB (NF-kB).

Human dipeptidyl-peptidase I. Gene characterization, localization, and expression

Dipeptidyl-peptidase I, a lysosomal cysteine proteinase, is important in intracellular degradation of proteins and appears to be a central coordinator for activation of many serine proteinases in immune/inflammatory cells. Little is known about the molecular genetics of the enzyme. In the present investigation the gene for dipeptidyl-peptidase I was cloned and characterized. The gene spans approximately 3.5 kilobases and consists of two exons and one intron. The genomic organization is distinct from the complex structures of the other members of the papain-type cysteine proteinase family. By fluorescence in situ hybridization, the gene was mapped to chromosomal region 11q14.1-q14.3. Analysis of the sequenced 5'-flanking region revealed no classical TATA or CCAAT box in the GC-rich region upstream of cap site. A number of possible regulatory elements that could account for tissue-specific expression were identified. Northern analyses demonstrated that the dipeptidyl-peptidase I message is expressed at high levels in lung, kidney, and placenta, at moderate to low levels in many organs, and at barely detectable levels in the brain, suggesting tissue-specific regulation. Among immune/inflammatory cells, the message is expressed at high levels in polymorphonuclear leukocytes and alveolar macrophages and their precursor cells. Treatment of lymphocytes with interleukin-2 resulted in a significant increase in dipeptidyl-peptidase I mRNA levels, suggesting that this gene is subjected to transcriptional regulation. The results provide initial insights into the molecular basis for the regulation of human dipeptidyl-peptidase I.

On stochastic approximation algorithms for classes of PAC learning problems

The classical stochastic approximation methods are shown to yield algorithms to solve several formulations of the PAC learning problem defined on the domain [0,1](d). Under some smoothness conditions on the probability measure functions, simple algorithms to solve some PAC learning problems are proposed based on networks of nonpolynomial units (e.g. artificial neural networks). Conditions on the sizes of the samples required to ensure the error bounds are derived using martingale inequalities.

Nitric oxide donor prevents hydrogen peroxide-mediated endothelial cell injury

Because nitric oxide is being used to treat acute lung injury and because it may either reduce or potentiate oxidant-mediated vascular injury, we studied the effect of the nitric oxide donor S-nitroso-N-acetyl-D-penicillamine (SNAP) on hydrogen peroxide (H2O2)-induced injury to cultured rat lung microvascular endothelial cells (RLMVC). Cells were exposed to H2O2 through its enzymatic generation by glucose and glucose oxidase or by its direct application. Glucose oxidase exposure causes a concentration- and time-dependent increase in 51chromium (51Cr) release from RLMVC. Catalase, dimethylthiourea or deferoxamine protects against this oxidant injury. SNAP (100 microM) prevents the increase in 51Cr release resulting from glucose oxidase or direct application of H2O2. N-acetyl-D-penicillamine is ineffective. Photo-decayed SNAP slightly decreases the 51Cr release caused by glucose oxidase but not the injury produced by directly adding H2O2. Treatment with the guanosine 3',5'-cyclic monophosphate (cGMP) analogue 8-BrcGMP (1-10 mM) provides no protection. SNAP decreases in vitro the net oxidation of ferrous to fcrric iron by H2O2, the iron-catalyzed consumption of H2O2 in Fenton's reaction, the iron-mediated generation of hydroxyl radicals, and the Fe(2+)-H2O2-catalyzed peroxidation of lipid membranes. Providing exogenous nitric oxide dramatically prevents H2O2-mediated endothelial injury, likely by reducing iron-mediated oxidant generation and subsequent lipid peroxidation.

Biosynthesis and processing of proteinase 3 in U937 cells. Processing pathways are distinct from those of cathepsin G

Proteinase 3 is a human polymorphonuclear leukocyte serine proteinase that degrades elastin in vitro and causes emphysema when administered by intratracheal insufflation into hamsters. Proteinase 3, stored in the azurophilic granules, is expressed in progenitor cells of myeloid origin. In the present study, the biosynthesis, processing, and intracellular transport of the enzyme was investigated in the human myelomonocytic cell line U937. Proteinase 3 is initially identified as a 35-kDa precursor and converted into the 29-kDa mature form within 3 h. By using a combination of techniques including amino-terminal sequencing, we identified the 35-kDa form as a zymogen containing an activation dipeptide but lacking the amino-terminal 25 residues, presumably the result of cleavage by a signal peptidase. Tunicamycin treatment and alkalinization of acidic cell compartments with NH4Cl did not prevent the processing of the proteinase 3 zymogen into the mature form, suggesting that the enzyme is targeted to the cytoplasmic granules by a mechanism other than the mannose 6-phosphate receptor. Brefeldin A inhibited the zymogen processing, suggesting that the dipeptide cleavage occurred in a post-Golgi organelle. The enzyme responsible for the removal of the dipeptide is a cysteine proteinase since E-64d, a class-specific inhibitor, prevented processing. However, treatment of cells with a dipeptidyl peptidase I inhibitor, Gly-Phe-diazomethyl ketone and with the lysosomotropic agents, NH4Cl and chloroquine, did not prevent dipeptide cleavage, indicating that the processing enzyme for proteinase 3 is not dipeptidyl peptidase I. In contrast, Gly-Phe-diazomethyl ketone inhibited cleavage of the dipeptide from cathepsin G. This indicates that processing of proteinase 3 is distinct from that of cathepsin G. Proteinase 3 is also processed at the COOH-terminal extension. Cleavage takes place next to Arg-222, suggesting that a trypsin-like proteinase is involved in the COOH-terminal processing.

Thoracic epidural analgesia compared with patient controlled intravenous morphine after upper abdominal surgery

Twenty-one ASA I or II patients undergoing upper abdominal surgery were studied for 24 hours after operation. They were entered into a prospective, randomised study of patient-controlled intravenous morphine compared with continuous thoracic epidural fentanyl combined with 0.2% bupivacaine. Pain relief was superior in the bupivacaine series (P < 0.05) throughout the 24 hour study period and this was associated with significantly greater pulmonary ventilation compared with the PCA series. Forced expiratory parameters were reduced in both series after the operation but significantly less so in the epidural group. There was a reduced incidence of emetic symptoms in the epidural group (P < 0.05) but the incidence of other minor side effects did not differ significantly. Thoracic epidural fentanyl/bupivacaine results in significantly better analgesia than patient-controlled intravenous morphine.

Interaction of secretory leukocyte protease inhibitor with proteinase-3

Secretory leukocyte protease inhibitor (SLPI) is a 12 kD nonglycosylated serine antiproteinase secreted by cells of mucosal surfaces. In human lung, SLPI is present in the respiratory epithelium. It is the major barrier to tissue destruction mediated by the polymorphonuclear leukocyte (PMN) serine proteinases, elastase and cathepsin G, within the upper respiratory tract. We have recently described a third PMN serine proteinase, proteinase-3, that like elastase causes lung matrix destruction and experimental emphysema. The current studies examine interactions between SLPI and proteinase-3. The results show that: (1) SLPI and its reactive-site variants have no or minimal inhibitory activity against proteinase-3; (2) native SLPI does not complex with proteinase-3; (3) proteinase-3 selectively degrades both native and oxidized SLPI; (4) the cleavage of SLPI by proteinase-3 occurs at the peptide bond COOH-terminal to Ala-16 in the NH2-terminal domain of SLPI.

Human neutrophil proteinase 3: mapping of the substrate binding site using peptidyl thiobenzyl esters

A series of peptidyl thiobenzyl esters was used to map the active site of human leukocyte proteinase 3. The steady-state kinetics parameters reveal the following features regarding the substrate specificity of proteinase 3 and its putative active site: (a) the preferred P1 residue is a small hydrophobic amino acid such as aminobutyric acid, norvaline, valine or alanine (in decreasing order of preference); (b) the enzyme has an extended active site; and (c) its active site is similar to that of the related serine proteinases leukocyte elastase and leukocyte cathepsin G.

Pulmonary epithelial cell urokinase-type plasminogen activator. Induction by interleukin-1 beta and tumor necrosis factor-alpha

Diffuse alveolar damage, presenting clinically as adult respiratory distress syndrome, is characterized initially by widespread intra-alveolar fibrin deposition. Alveolar epithelial cells play a central role in the subsequent repair process. We have recently shown that alveolar epithelial cells have the capacity to promote fibrinolysis (Marshall, B. C., Sageser, D. S., Rao, N. V., Emi, M., and Hoidal, J. R. (1990) J. Biol. Chem. 265, 8198-8204) and may therefore directly participate in the extensive remodeling that follows acute lung injury. Because the tissue repair process occurs in an acute inflammatory setting, we investigated the effects of inflammatory mediators on urokinase-type plasminogen activator (u-PA) expression by pulmonary epithelial cells. We found that interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) upregulated PA activity in A549 human pulmonary epithelial cells. Biosynthetic labeling and immunoprecipitation showed that both cytokines caused marked accumulation of newly synthesized u-PA. Northern blot analyses demonstrated that both IL-1 beta and TNF-alpha induced relatively rapid accumulation of u-PA mRNA which did not require de novo protein synthesis and was substantially inhibited by glucocorticoids. Nuclear run-off transcription studies showed that both cytokines caused rapid transcriptional activation of the u-PA gene. While the effects of IL-1 beta and TNF-alpha were qualitatively similar, some differences emerged. Most notably, TNF-alpha led to a more sustained accumulation of u-PA mRNA than did IL-1 beta. In contrast to their effects on u-PA expression, IL-1 beta and TNF-alpha had minimal effect on PA inhibitor-1 expression. These effects of IL-1 beta and TNF-alpha, mediators known to play a key role in acute lung injury and inflammation, may promote lysis of alveolar fibrin by alveolar epithelium, thereby aiding in restoration of normal lung architecture.

Primary structure of a Thomsen-Friedenreich-antigen-specific lectin, jacalin [Artocarpus integrifolia (jack fruit) agglutinin]. Evidence for the presence of an internal repeat

Jacalin [Artocarpus integrifolia (jack fruit) agglutinin] is made up of two types of chains, heavy and light, with M(r) values of 16,200 +/- 1200 and 2090 +/- 300 respectively (on the basis of gel-permeation chromatography under denaturing conditions). Its complete amino acid sequence was determined by manual degradation using a 4-dimethylaminoazobenzene 4'-isothiocyanate double-coupling method. Peptide fragments for sequence analysis were obtained by chemical cleavages of the heavy chain with CNBr, hydroxylamine hydrochloride and iodosobenzoic acid and enzymic cleavage with Staphylococcus aureus proteinase. The peptides were purified by a combination gel-permeation and reverse-phase chromatography. The light chains, being only 20 residues long, could be sequenced without fragmentation. Amino acid analyses and carboxypeptidase-Y-digestion C-terminal analyses of the subunits provided supportive evidence for their sequence. Computer-assisted alignment of the jacalin heavy-chain sequence failed to show sequence similarity to that of any lectin for which the complete sequence is known. Analyses of the sequence showed the presence of an internal repeat spanning residues 7-64 and 76-130. The internal repeat was found to be statistically significant.

Thermodynamic and kinetic studies on the mechanism of binding of methylumbelliferyl glycosides to jacalin

The binding of Artocarpus integrifolia lectin (jacalin) to 4-methylumbelliferyl (Meumb)-glycosides, Gal alpha Meumb, Gal beta Meumb, GalNAc alpha Meumb, GalNAc beta-Meumb, and Gal beta 3GalNAc beta Meumb was examined by extrinsic fluorescence quenching titration and stopped flow spectrofluorimetry. The binding was characterized by 100% quenching of fluorescence of Meumb-glycosides. Their association constants range from 2.0 x 10(4) to 1.58 x 10(6) M-1 at 15 degrees C. Entropic contribution is the major stabilizing force for avid binding of Meumb-glycosides indicating the existence of a hydrophobic site that is complementary to their methylumbelliferyl group. The second order association rate constants for interaction of these sugars with lectin at 15 degrees C vary from 8.8 x 10(5) to 3.24 x 10(6) M-1 S-1, at pH 7.2. The first order dissociation rate constants range from 2.30 to 43.0 S-1 at 15 degrees C. Despite the differences in their association rate constants, the overall values of association constants for these saccharides are determined by their dissociation rate constants. The second order rate constant for the association of Meumb-glycosides follows a pattern consistent with the magnitude of the activation energies involved therin. Activation parameters for association of all ligands illustrate that the origin of the barrier between binding of jacalin to Meumb-glycosides is entropic, and the enthalpic contribution is small. A correlation between these parameters and the structure of the ligands on the association rates underscores the importance of steric factors in determining protein saccharide recognitions.

Oocyte maturation in Clarias batrachus: in vitro effect of various gonadotropins and homologous pituitary homogenate

The effects of five different gonadotropins and homologous pituitary homogenate (HP) on germinal vesicle breakdown (GVBD) were investigated in vitro using folliculated oocytes of Clarias batrachus. Among all the gonadotropins, salmon gonadotropin (SG-G100) was the most potent in vitro inducer of oocyte maturation. At concentrations of 1, 0.1, 0.01 and 0.001 microgram/ml it induced 86.98 +/- 2.71, 68.74 +/- 2.85, 44.56 +/- 1.75 and 25.90 +/- 2.36% GVBD. Next to SG-G100 in inducing GVBD was luteinizing hormone (LH) which was consistently found to be effective at all the concentrations used. Human chorionic gonadotropin was also found to be effective at all the concentrations but when compared to SG-G100 and LH, it was less effective. Follicle stimulating hormone and pregnant mare serum gonadotropin were found to be effective at higher concentrations but were ineffective at the lowest concentration. HP treatment resulted in a significant number of GVBD at all the three concentrations used.

Oocyte maturation inClarias batrachus. III. Purification and characterization of maturation-inducing steroid

Maturation-inducing steroid (MIS) in the Indian female catfish,Clarias batrachus, was purified and characterized from the incubation medium in which fully grown but immature folliculated oocytes were incubated with salmon gonadotropin (SG-G100) for 36 h. Maturation-inducing (MI) activity of residues obtained at various steps of extraction and purification was assessed byin vitro germinal vesicle breakdown (GVBD) assay using folliculated oocytes ofC. batrachus. The post incubation medium was extracted with diethyl ether. The ether phase was partitioned using 50% methanol plus n-hexane. The methanol phase which had MI activity was fractionated into 7 fractions using reverse-phase high-performance liquid chromatography. Of these 7 fractions, fraction 3 was found to be active in having MI ability and identified as 17 α,20β-dihydroxy-4-pregnen-3-one (17α,20β-diOHprog). The authenticity of 17α,20β-diOHprog as the major follicular mediator of gonadotropin-induced oocyte maturation was further confirmed by thin-layer chromatography (TLC) in which fraction 3 was run along with authentic 17α,20β-diOHprog standard. This investigation gives a direct evidence that 17α,20β-diOHprog is the major naturally occurring MIS in Indian female catfish,C. batrachus.

Characterization of proteinase-3 (PR-3), a neutrophil serine proteinase. Structural and functional properties

Proteinase 3 (PR-3) is a human polymorphonuclear leukocyte (PMNL) serine proteinase that degrades elastin in vitro and causes emphysema when administered by tracheal insufflation to hamsters (Kao, R. C., Wehner, N. G., Skubitz, K. M., Gray, B. H., and Hoidal, J. R. (1988) J. Clin. Invest. 82, 1963-1973). We have determined the primary structure of several PR-3 peptides and have analyzed catalytic properties of the enzyme. The enzyme has considerable amino acid sequence homology with two other well characterized PMNL neutral serine proteinases, elastase and cathepsin G. Furthermore, the NH2-terminal amino acid sequence of PR-3 is identical to that of the target antigen of the anti-neutrophil cytoplasmic autoantibodies associated with Wegener's granulomatosis. PR-3 degrades a variety of matrix proteins including fibronectin, laminin, vitronectin, and collagen type IV. It shows no or minimal activity against interstitial collagens types I and III, respectively. The analysis of peptides generated by PR-3 digestion of insulin chains and the activity profile against a panel of chromogenic synthetic peptide substrates show that PR-3 prefers small aliphatic amino acids (alanine, serine, and valine) at the P1 site. The elastase-like specificity of PR-3 is consistent with its striking sequence homology to elastase at substrate binding sites. PR-3 is inhibited by alpha 1-proteinase inhibitor (ka = 8.1 x 10(6) M-1 S-1; delay time = 25 ms) and alpha 2-macroglobulin (ka = 1.1 x 10(7) M-1 S-1; delay time = 114 ms) but not by alpha 1-anti-chymotrypsin. In contrast to elastase and cathepsin G, PR-3 is not inhibited by secretory leukoprotease inhibitor and is weakly inhibited by eglin c. Thus, PR-3 is distinct from the other PMNL proteinases.

Structural features of the sulphated polysaccharide from a green seaweed, Spongomorpha indica

A sulphated heteropolysaccharide, [alpha]D +59 degrees, was isolated from a green seaweed, Spongomorpha indica, by extraction with ammonium oxalate. The polymer is composed of arabinose, xylose, galactose and glucose in the ratio 8.9:1.0:12.0:1.0. Studies showed that the polysaccharide is a complex and multilinked polymer containing arabinose in both furanose and pyranose forms. The core of the polysaccharide is composed of 1,4-linked galactose units. The arabinofuranose units are present as non-reducing end units, as well as jointed through 1,3- and 1,2-linkages. The majority of the arabinopyranose units are joined through 1,4-linkages. Xylose is present as a branch terminating unit. Glucose is joined through 1,4-linkages. Both arabinose and galactose carry branches. Sulphate groups are present on some of the arabinose units at C-2 and on some of the galactose units at C-2 and C-3.

Ibuprofen prevents oxidant lung injury and in vitro lipid peroxidation by chelating iron

Because ibuprofen protects from septic lung injury, we studied the effect of ibuprofen in oxidant lung injury from phosgene. Lungs from rabbits exposed to 2,000 ppm-min phosgene were perfused with Krebs-Henseleit buffer at 50 ml/min for 60 min. Phosgene caused no increase in lung generation of cyclooxygenase metabolites and no elevation in pulmonary arterial pressure, but markedly increased transvascular fluid flux (delta W = 31 +/- 5 phosgene vs. 8 +/- 1 g unexposed, P less than 0.001), permeability to albumin (125I-HSA) lung leak index 0.274 +/- 0.035 phosgene vs. 0.019 +/- 0.001 unexposed, P less than 0.01; 125I-HSA lavage leak index 0.352 +/- 0.073 phosgene vs. 0.008 +/- 0.001 unexposed, P less than 0.01), and lung malondialdehyde (50 +/- 7 phosgene vs. 24 +/- 0.7 mumol/g dry lung unexposed, P less than 0.01). Ibuprofen protected lungs from phosgene (delta W = 10 +/- 2 g; lung leak index 0.095 +/- 0.013; lavage leak index 0.052 +/- 0.013; and malondialdehyde 16 +/- 3 mumol/g dry lung, P less than 0.01). Because iron-treated ibuprofen failed to protect, we studied the effect of ibuprofen in several iron-mediated reactions in vitro. Ibuprofen attenuated generation of .OH by a Fenton reaction and peroxidation of arachidonic acid by FeCl3 and ascorbate. Ibuprofen also formed iron chelates that lack the free coordination site required for iron to be reactive. Thus, ibuprofen may prevent iron-mediated generation of oxidants or iron-mediated lipid peroxidation after phosgene exposure. This suggests a new mechanism for ibuprofen's action.

Role of cytochrome P-450 in reperfusion injury of the rabbit lung

Reactive oxygen species are a major cause of damage occurring in ischemic tissue after reperfusion. During reperfusion transitional metals such as iron are required for reactive oxygen species to mediate their major toxic effects. Xanthine oxidase is an important source of reactive oxygen species during ischemia-reperfusion injury, but not in all organs or species. Because cytochrome P-450 enzymes are an important pulmonary source of superoxide anion (O2-.) generation under basal conditions and during hyperoxia, and provide iron catalysts necessary for hydroxyl radical (.OH) formation and propagation of lipid peroxidation, we postulated that cytochrome P-450 might have a potential role in mediating ischemia-reperfusion injury. In this report, we explored the role of cytochrome P-450 enzymes in a rabbit model of reperfusion lung injury. The P-450 inhibitors 8-methoxypsoralen, piperonyl butoxide, and cimetidine markedly decreased lung edema from transvascular fluid flux. Cimetidine prevented the reperfusion-related increase in lung microvascular permeability, as measured by movement of 125I-albumin from the vascular space into lung water and alveolar fluid. P-450 inhibitors also prevented the increase in lung tissue levels of thiobarbituric acid reactive products in the model. P-450 inhibitors did not block enhanced O2-. generation by ischemic reperfused lungs, measured by in vivo reduction of succinylated ferricytochrome c in lung perfusate, but did prevent the increase in non-protein-bound low molecular weight chelates of iron after reperfusion. Thus, cytochrome P-450 enzymes are not likely a major source of enhanced O2-. generation, but serve as an important source of iron in mediating oxidant injury to the rabbit lung during reperfusion. These results suggest an important role of cytochrome P-450 in reperfusion injury to the lung and suggest potential new therapies for the disorder.

Sulfated polysaccharides prevent human leukocyte elastase-induced acute lung injury and emphysema in hamsters

Studies were designed to explore the possibility that sulfated polysaccharides had the potential to prevent human leukocyte elastase (HLE)-induced lung injury. Arteparon (GAGPS), heparin, heparan sulfate, chondroitin sulfate, and dextran sulfate, but not dextran, inhibited HLE-mediated hydrolysis of succinyl-ala2-val-pNA. GAGPS, used as a paradigmatic sulfated polysaccharide, was a potent inhibitor of elastolysis in vitro. GAGPS given intratracheally prevented acute injury and emphysema in hamsters when administered up to 8 h before HLE insufflation. The results suggest that sulfated polysaccharides may be potent inhibitors of HLE-mediated lung injury.

Alveolar epithelial cell plasminogen activator. Characterization and regulation

Intra-alveolar fibrin deposition is one of the pathological hallmarks of acute lung injury. Because alveolar epithelial cells play a central role in the repair process following acute lung injury, this study was undertaken to examine their potential to produce a plasminogen activator (PA). We now report the synthesis and secretion of PA by rat alveolar epithelial cells with the catalytic properties of a urokinase-type (u-PA) rather than tissue-type plasminogen activator. Studies of regulation of epithelial cell u-PA revealed: 1) phorbol myristate acetate (PMA) but not the inactive structural analog 4 alpha-PMA upregulated u-PA synthesis, putatively via the protein kinase C pathway; 2) PMA induction of u-PA activity was substantially inhibited by dexamethasone and completely inhibited by cycloheximide; 3) unstimulated alveolar epithelial cells had no detectable u-PA mRNA, whereas PMA exposure led to activation of the u-PA gene and accumulation of a 2.5-kilobase u-PA mRNA; and 4) cycloheximide did not abolish this induction of u-PA mRNA suggesting that intermediate protein synthesis was not necessary for the activation of transcription. In light of their capacity to promote fibrinolysis and their strategic anatomic location, alveolar epithelial cells are likely to play a key role in the extensive remodelling process that follows acute lung injury.

Hydroxyl radical generating activity of hydrous but not calcined kaolin is prevented by surface modification with dipalmitoyl lecithin

The catalytic activity of kaolin, an aluminum silicate, for generating hydroxyl radicals (.OH) from hydrogen peroxide (H2O2) was studied in a chemical system that measured .OH as evolution of methane (CH4) from dimethyl sulfoxide. In the presence of a reducing agent and 10 mM H2O2, hydrous and calcined kaolin generated mean +/- SE CH4 concentrations of 1634 +/- 328 and 1395 +/- 29 ppm, respectively. Surface modification with dipalmitoyl lecithin, the lipid of pulmonary surfactant, blocked generation of .OH in hydrous kaolin (38 +/- 38 ppm CH4) but not in calcined kaolin (875 +/- 262 ppm CH4). The catalytic activity of kaolin for producing .OH from H2O2 may be important in the pathogenesis of kaolin toxicity, and calcined kaolin may be more toxic than hydrous kaolin because the calcined form is resistant to surface modification by lipids of pulmonary surfactant.

Differences in lung function and prevalence of pneumoconiosis between two kaolin plants

To investigate the origin of differences in previously published pulmonary function studies of workers in kaolin plants in Georgia, spirometric and radiographic data collected in a cross sectional survey of two large plants were analysed. As compared with workers in plant 2, workers in plant 1 had a 2.7-fold greater prevalence of pneumoconiosis and a mean 0.361 decrement in adjusted forced vital capacity. Our previous finding that exposure to kaolin was not associated with a decrement in lung function may have resulted from failure to consider differences between the plants.

Role of reactive oxygen species in reperfusion injury of the rabbit lung

We have developed a model of reperfusion injury in Krebs buffer-perfused rabbit lungs, characterized by pulmonary vasoconstriction, microvascular injury, and marked lung edema formation. During reperfusion there was a threefold increase in lung superoxide anion (O2-) production, as measured by in vivo reduction of nitroblue tetrazolium, and a twofold increase in the release of O2- into lung perfusate, as measured by reduction of succinylated ferricytochrome c. Injury could be prevented by the xanthine oxidase inhibitor allopurinol, the O2- scavenger SOD, the hydrogen peroxide scavenger catalase, the iron chelator deferoxamine, or the thiols dimethylthiourea or N-acetylcysteine. The protective effect of SOD could be abolished by the anion channel blocker 4,4'-diisothiocyano-2,2'-stilbene disulfonic acid, indicating that SOD consumes O2- in the extracellular medium, thereby creating a concentration gradient favorable for rapid diffusion of O2- out of cells. Our results extend information about the mechanisms of reperfusion lung injury that have been assembled by studies in other organs, and offer potential strategies for improved organ preservation, for treatment of reperfusion injury after pulmonary thromboembolectomy, and for explanation and therapy of many complications of pulmonary embolism.

Dusts causing pneumoconiosis generate .OH and produce hemolysis by acting as Fenton catalysts

Silicates causing pneumoconiosis function as Fenton catalysts to generate hydroxyl radicals (.OH) when incubated with hydrogen peroxide and a reducing substance. In contrast, silicates which do not cause pneumoconiosis demonstrate no Fenton activity. Catalytic activity is decreased by pretreatment of silicates with the iron chelators deferoxamine or transferrin. Hemolysis from silicates is decreased by interventions which remove superoxide anion or hydrogen peroxide from the medium, or by pretreatment of dusts with iron chelators. Thus, asbestos and nonfibrous silicates may cause pneumoconiosis through a common oxidant mechanism by catalyzing production of toxic .OH radicals in the lung.