Noëlla Germain

Increase in macrophage elastase (MMP-12) in lungs from patients with chronic obstructive pulmonary disease.

Abstract.Objective and design: Chronic obstructive pulmonary disease (COPD) is characterized by an inflammatory process and airway remodeling involving matrix metalloproteinases (MMPs). Thus, we analyzed the expression and release of MMP-12 (macrophage metalloelastase) in bronchoalveolar lavage (BAL) and lung tissue from COPD patients and control subjects.Methods: Immunocytochemistry and immunochemistry were performed to analyze the expression of MMP-12 in BAL cells and bronchial biopsies. Western blotting was used for the evaluation of MMP-12 in BAL fluids.Results: The number of MMP-12 expressing macrophages together with the staining intensity was higher in BAL samples from COPD patients than in controls subjects. Similar results were noted in bronchial biopsies with higher MMP-12 expression in COPD subjects than in controls. Enhanced MMP-12 level was also observed in BAL fluids from patient with COPD in comparison to control subjects.Conclusion: This study demonstrated that COPD patients produce greater quantities of MMP-12 than controls, which may be a critical step in the pathogenesis of COPD and emphysema.

Influence of fatty acid ethanolamides and Δ9-tetrahydrocannabinol on cytokine and arachidonate release by mononuclear cells

The effects of arachidonic acid ethanolamide (anandamide), palmitoylethanolamide and delta9-tetrahydrocannabinol on the production of tumor necrosis factor-alpha (TNF-alpha), interleukin-4, interleukin-6, interleukin-8, interleukin-10, interferon-gamma, p55 and p75 TNF-alpha soluble receptors by stimulated human peripheral blood mononuclear cells as well as [3H]arachidonic acid release by non-stimulated and N-formyl-Met-Leu-Phe (fMLP)-stimulated human monocytes were investigated. Anandamide was shown to diminish interleukin-6 and interleukin-8 production at low nanomolar concentrations (3-30 nM) but inhibited the production of TNF-alpha, interferon-gamma, interleukin-4 and p75 TNF-alpha soluble receptors at higher concentrations (0.3-3 microM). Palmitoylethanolamide inhibited interleukin-4, interleukin-6, interleukin-8 synthesis and the production of p75 TNF-alpha soluble receptors at concentrations similar to those of anandamide but failed to influence TNF-alpha and interferon-gamma production. The effect of both compounds on interleukin-6 and interleukin-8 production disappeared with an increase in the concentration used. Neither anandamide nor palmitoylethanolamide influenced interleukin-10 synthesis. delta9-Tetrahydrocannabinol exerted a biphasic action on pro-inflammatory cytokine production. TNF-alpha, interleukin-6 and interleukin-8 synthesis was maximally inhibited by 3 nM delta9-tetrahydrocannabinol but stimulated by 3 microM delta9-tetrahydrocannabinol, as was interleukin-8 and interferon-gamma synthesis. The level of interleukin-4, interleukin-10 and p75 TNF-alpha soluble receptors was diminished by 3 microM delta9-tetrahydrocannabinol. [3H]Arachidonate release was stimulated only by high delta9-tetrahydrocannabinol and anandamide concentrations (30 microM). These results suggest that the inhibitory properties of anandamide, palmitoylethanolamide and delta9-tetrahydrocannabinol are determined by the activation of the peripheral-type cannabinoid receptors, and that various endogenous fatty acid ethanolamides may participate in the regulation of the immune response.

Inhibition of bleomycin-induced pulmonary fibrosis in mice by the matrix metalloproteinase inhibitor batimastat.

Bleomycin‐induced pulmonary fibrosis is known to be associated with the increased activity of two gelatinases, matrix metalloproteinase (MMP)‐2 and MMP‐9, in bronchoalveolar lavage (BAL). This study has investigated the effect of a synthetic inhibitor of MMP, batimastat, on the development of pulmonary fibrosis induced by bleomycin administration in mice. Animals wereintranasally instilled with saline or bleomycin (0.5 mg in 100 µl per mouse). Batimastat (30 mg/kg) or vehicle alone was administered by intraperitoneal injection 24 h and 1 h before saline or bleomycin instillation, and then daily at the same dosage until the end of the study. Fifteen days after bleomycin administration, BAL was performed and the lung was removed. Treatment of mice with batimastat significantly reduced bleomycin‐induced lung fibrosis, as shown in the lung by histopathological examination and by a decrease in hydroxyproline levels. Batimastat also prevented the increase in BAL macrophage and lymphocyte numbers, whereas it did not show any effect on the increased expression of active transforming growth factor‐beta (TGF‐β) in BAL. Batimastat treatment was effective in reducing MMP‐2 and MMP‐9 activity as well as the tissue inhibitor of metalloproteinase‐1 (TIMP‐1) level in BAL. These results suggest that administration of the MMP inhibitor batimastat is useful in preventing experimental pulmonary fibrosis induced by bleomycin and raises the possibility of a therapeutic approach to human pulmonary fibrotic disease. Copyright

Effects of cannabinoid receptor ligands on LPS-induced pulmonary inflammation in mice

The effects of cannabinoid receptor agonists WIN 55,212-2, delta9-tetrahydrocannabinol (delta9-THC), arachidonoylethanolamide (anandamide) and palmitoylethanolamide on lipopolysaccharide (LPS) -induced bronchopulmonary inflammation in mice were investigated. WIN 55,212-2 and delta9-THC induced a concentration-dependent decrease in TNF-alpha level in the bronchoalveolar lavage fluid (BALF) (maximum inhibition 52.7% and 36.9% for intranasal doses of 750 nmol x kg(-1) and 2.65 mmol x kg(-1), respectively). This effect was accompanied by moderately reduced neutrophil recruitment. Palmitoylethanolamide (750 nmol x kg(-1)) diminished the level of TNF-alpha in BALF by 31.5% but had no effect on neutrophil recruitment. Anandamide (7.5-750 nmol x kg(-1)) did not influence the inflammatory process but TNF-alpha level and neutrophil recruitment were decreased by 28.0% and 62.0%, respectively, with 0.075 nmol x kg(-1). These results demonstrate that the cannabinoid receptor ligands inhibited LPS-induced pulmonary inflammation and suggest that this effect could be at least in part mediated by the cannabinoid CB2 receptor.

Imbalance between matrix metalloproteinases (MMP-9 and MMP-2) and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) in acute respiratory distress syndrome patients.

ObjectiveMatrix metalloproteinases (MMPs) are known to be involved in degradation of extracellular matrix. We aimed to assess the role of MMPs and their natural inhibitors (TIMPs) in the genesis and the evolution of acute respiratory distress syndrome (ARDS). DesignProspective, clinical study. SettingIntensive care unit of a university hospital. PatientsTwenty-one patients were assigned to three different groups: Group 1 patients developed ARDS that rapidly resolved in <4 days; Group 2 patients developed ARDS lasting >8 days; Group 3 (control group) patients had clinical criteria for hospital-acquired pneumonia without ARDS. InterventionBronchoalveolar lavages were performed on day 0 of the onset of ARDS and on days 4, 8, and 12 for unresolving ARDS. For group 3, the bronchoalveolar lavages were performed on day 0 of the pneumonia. On these bronchoalveolar lavage fluids, we measured the amount of MMP-9 and -2 and their inhibitors TIMP-1 and -2. Measurements and Main ResultsThe amount of MMP-9 measured by enzyme-linked immunosorbent assay was significantly lower in the bronchoalveolar lavages from patients with ARDS (group 1 and group 2) compared with the control group (p < .01) throughout the study. The ratio MMP-9/TIMP-1 was also significantly smaller and was less than one in the two ARDS groups (p < .05) compared with the control group (group 3), where this ratio was greater than one. In the second bronchoalveolar lavages, this ratio was greater than one only in the ARDS group that rapidly resolved (group 1), whereas it stayed less than one when the ARDS was lasting (group 2). Concerning the quantity of MMP-2 and the ratio MMP-2/TIMP-2, there was no statistical difference between the three groups throughout the study. Using zymography, there was no significant difference in the amounts of active and latent MMP-9 between the three groups. Moreover, no significant difference in the quantity of latent and active MMP-2 in the three groups was noted. ConclusionThese results suggest that the MMP-9 level and MMP-9/TIMP-1 ratio play a role in the pathogenesis of ARDS and, namely, the imbalance between MMP-9 and TIMP-1 would participate in airway remodeling leading to either short- or long-course ARDS. The ratio MMP-9/TIMP-1 could be a predictive factor of the ARDS evolution.

Repeated endotoxin exposure induces interstitial fibrosis associated with enhanced gelatinase (MMP-2 and MMP-9) activity

Abstract:Background: Dysregulation of matrix metalloproteinases (MMPs) has been implicated in lung injury associated with inflammatory disorders and several lung diseases such as pulmonary fibrosis.¶Objective: We studied a murine model of lipopolysaccharide (LPS)-induced chronic inflammation in order to analyse the relationship between MMP activity in bronchoalveolar lavage fluid and collagen deposition in lung tissue. BP2 mice were exposed to repeated aerosols of LPS of E. coli for 8 months.¶Results: The inflammatory reaction induced by LPS increased throughout the time of exposure and was associated after 10 weeks with collagen deposition in the alveolar walls. Meantime, we observed in BAL fluid from LPS-exposed mice an early induction of MMP-9 correlated with neutrophil recruitment. MMP-2 increased during the early inflammatory phase, and also during the development of the fibrotic phase.¶Conclusion: Repeated exposure of mice to an aerosol of LPS can lead to pulmonary interstitial fibrosis and MMPs seem to be associated with this process.¶

Modulation of airway remodeling-associated mediators by the antifibrotic compound, pirfenidone, and the matrix metalloproteinase inhibitor, batimastat, during acute lung injury in mice

Matrix metalloproteinases (MMPs) are potent to degrade basement membrane collagen associated with acute lung injury in inflammatory processes. We have investigated effects of pirfenidone, antifibrotic agent, and batimastat, inhibitor of MMPs, on gelatinase activities, on release of tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta), as well as on recruitment of inflammatory cells in bronchoalveolar lavage (BAL) fluid after aerosol administration of lipopolysaccharide (LPS) in mice. Pretreatment with pirfenidone reduced neutrophil recruitment, TNF-alpha and TGF-beta levels, and MMP-9 secretion. In contrast, pretreatment with batimastat (30 or 60 mg/kg, i.p.) only reduced TNF-alpha and TGF-beta levels. Batimastat did not reduce MMP secretion in BAL fluid but inhibited MMP-9 activity. The increase in tissue inhibitor of matrix metalloproteinase (TIMP)-1 induced by LPS was not modified by the two drugs. These findings demonstrate that the two drugs can inhibit the in vivo increase in MMP induced by LPS, batimastat with a direct inhibitor effect on MMP activity and pirfenidone as a consequence of its antiinflammatory effect.

Prevention by the tachykinin NK2 receptor antagonist, SR 48968, of antigen‐induced airway hyperresponsiveness in sensitized guinea‐pigs

The involvement of tachykinins in antigen‐induced airway hyperresponsiveness (AHR) was characterized pharmacologically in guinea‐pigs sensitized to ovalbumin with antagonists of tachykinin NK1 and NK2 receptors, namely SR 140333 and SR 48968, respectively. AHR was illustrated by increased sensitivity to bronchoconstriction provoked by aerosolized acetylcholine in anaesthetized, ventilated animals, administrated 48 h after ovalbumin aerosol challenge. SR 48968 (1 mg kg−1, i.p.), when given once 30 min before the antigen challenge, prevented AHR, whereas SR 140333 did not. These findings suggest that the tachykinin NK2 receptor antagonist, SR 48968, may be useful for investigating mechanisms of tachykinins in the development of airway hyperresponsiveness.

Inhibition of inflammatory cell recruitment by the tachykinin NK3-receptor antagonist, SR 142801, in a murine model of asthma

Several observations suggest that tachykinins (substance P, neurokinin A and neurokinin B) are involved in the pathogenesis of pulmonary diseases and elicit several airway responses such as bronchoconstriction and neurogenic inflammation via interactions with specific receptors denoted NK(1), NK(2) and NK(3). We have investigated the effect of a selective antagonist for tachykinin NK(3) receptor, SR 142801 ((R)-(N)-(1-(3-(1-benzoyl-3-(3,4-dichlorophenyl)piperidin-3-yl)propyl)-4-phenylpiperidin-4-yl-N-methylacetamide), on the inflammatory cell recruitment in ovalbumin-sensitized and -challenged mice used as a model of allergic asthma. Twenty hours after the two-ovalbumin challenges, differential cell counts were calculated and indicated that SR 142801 caused a significant decrease in the number of neutrophils and eosinophils. Forty hours after the last ovalbumin exposure, SR 142801 induced a significant decrease in the recruitment of eosinophils. These results suggest that tachykinins and tachykinin NK(3) receptors can interfere with cell recruitment in inflammatory response.

Effect of the cannabinoid receptor ligand, WIN 55,212-2, on superoxide anion and TNF-α production by human mononuclear cells

Cannabinoids are known to downregulate immune response but the role for cannabinoid receptors in cannabinoid-induced immunosuppression is still unclear. To address this question, the interference of CB1 and CB2 receptor antagonists with the inhibition of TNF-alpha production by synthetic cannabinoid WIN 55,212-2 was studied using human peripheral blood mononuclear cells (PBMC) in vitro. CB2 (SR 144528) but not CB1 (SR 141716A) receptor antagonist dose dependently interfered with WIN 55,212-2-induced inhibition of TNF-alpha synthesis. Also, WIN 55,212-2 decreased fMLP-induced reactive oxygen species generation in lipopolysaccharide (LPS)-primed PBMC. However, the high concentrations of cannabinoid receptor ligands needed to achieve significant effects suggest that the observed effects may be in part cannabinoid receptor independent.