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M Perretti

Publications and source records attributed to M Perretti.

At least 19 recordsLinked to original sources
PubMed2007

Formyl peptide receptors and the regulation of ACTH secretion: targets for annexin A1, lipoxins, and bacterial peptides.

The N-formyl peptide receptors (FPRs) are a family of G-protein coupled receptors that respond to proinflammatory N-formylated bacterial peptides (e.g., formyl-Met-Leu-Phe, fMLF) and, thus, contribute to the host response to bacterial infection. Paradoxically, a growing body of evidence suggests that some members of this receptor family may also be targets for certain anti-inflammatory molecules, including annexin A1 (ANXA1), which is an important mediator of glucocorticoid (GC) action. To explore further the potential role of FPRs in mediating ANXA1 actions, we have focused on the pituitary gland, where ANXA1 has a well-defined role as a cell-cell mediator of the inhibitory effects of GCs on the secretion of corticotrophin (ACTH), and used molecular, genetic, and pharmacological approaches to address the question in well-established rodent models. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis identified mRNAs for four FPR family members in the mouse anterior pituitary gland, Fpr-rs1, Fpr-rs2, Fpr-rs6, and Fpr-rs7. Functional studies confirmed that, like dexamethasone, ANXA1 and two ANXA1-derived peptides (ANXA1(1-188) and ANXA1(Ac2-26)) inhibit the evoked release of ACTH from rodent anterior pituitary tissue in vitro. Fpr1 gene deletion failed to modify the pituitary responses to dexamethasone or ANXA1(Ac2-26). However, lipoxin A4 (LXA4, 0.02-2 microM, a lipid mediator with high affinity for Fpr-rs1) mimicked the inhibitory effects of ANXA1 on ACTH release as also did fMLF in high (1-100 microM) but not lower (10-100 nM) concentrations. Additionally, a nonselective FPR antagonist (Boc1, 100 microM) overcame the effects of dexamethasone, ANXA1(1-188), ANXA1(Ac2-26), fMLF, and LXA4 on ACTH release, although at a lower concentration (50 microM), it was without effect. Together, the results suggest that the actions of ANXA1 in the pituitary gland are independent of Fpr1 but may involve other FPR family members, in particular, Fpr-rs1 or a closely related receptor. They thus provide the first evidence for a role of the FPR family in the regulation of neuroendocrine function.

Adrenocorticotropic Hormone↗
PubMed2006

Inflammation-induced modulation of cellular galectin-1 and -3 expression in a model of rat peritonitis.

OBJECTIVE AND DESIGN: To investigate the effect of galectin-1 (Gal-1) and -3 (Gal-3) on leukocyte migration and analyze the expression of both galectins in inflammatory cells using a model of rat peritonitis. MATERIAL OR SUBJECTS: Sprague-Dawley rats (n = 4 per group). TREATMENT: Peritonitis was induced in animals through intraperitoneal injection of carrageenin (1.5 mg/kg) and rat mesenteries were analyzed at different time points (0, 4, 24 and 48h). For pharmacological treatment, rats received intravenous injection of Gal-1 or -3 (3microg/kg) followed by carrageenin. METHODS: Western blotting and immunoelectron microscopy analysis. Statistical analysis was performed using ANOVA followed by Bonferroni test. RESULTS: Pharmacological treatment with Gal-1, but not Gal-3, inhibited (approximately 50 %) leukocyte recruitment into the peritoneal cavity at 4 h time-point. In this early phase, immunogold staining of mesenteries showed a diminished Gal-3 expression in degranulated mast cells and Gal-1 in transmigrated neutrophils (approximately 20 % reduction compared to intravascular cells). In the later phases (24 and 48h), leukocyte turnover was associated with augmented Gal-1 expression in neutrophils and macrophages and Gal-3 in mast cells and macrophages. CONCLUSIONS: These results point to a balanced expression of cell-associated-Gal-1/Gal-3 and might impact on the development of new therapeutic strategies for inflammatory diseases.

Animals↗
PubMed2005

Macrophage biology in the Anx-A1-/- mouse.

Historical data suggested that a soluble protein, since identified as annexin-A1 (Anx-A1) was released from macrophages following glucocorticoid stimulation and could modulate eicosanoid production and other functions of these cells. Here, we review some recent findings using a line of Anx-A1(-/-) mice to explore the impact of Anx-A1 gene deletion on macrophage biology. The absence of Anx-A1 selectively alters phagocytic capacity of rodent resident peritoneal macrophages apparently through changes in surface adhesion molecule expression. Anx-A1 is also apparently important in the tonic down-regulation of other macrophage functions such as COX-2 induction, PGE(2) release and the production of reactive oxygen species.

Animals↗
PubMed2005

The inhibition of neutrophil-endothelial cell adhesion by hyaluronan independent of CD44.

OBJECTIVE: To study the effect of hyaluronan on cell adhesion and recruitment both in vitro and in vivo, since hyaluronan both inhibits restenosis and is anti-inflammatory. When administered to animals undergoing angioplasty the recruitment of cells into the restenotic plaque is inhibited, as well as into inflammatory lesions. The recent discovery that ICAM-1 binds hyaluronan and exhibits the B(X(7))B HA binding motif, led us also to investigate whether cell adhesion could be modulated by hyaluronan. MATERIALS AND METHODS: Human neutrophils were adhered to human umbilical vein (HUVEC) or Ea.hy.926 HUVEC cells stimulated with phorbol myristate acetate (PMA) or tumour necrosis factor (TNFalpha). Neutrophil binding in vivo utilized FMLP-stimulated hamster cheek pouch post-capillary venules. RESULTS: Hyaluronan inhibited human neutrophil adhesion to both PMA and TNFalpha-stimulated HUVEC. Ea.hy.926 human immortal HUVECs expressed ICAM-1 in response to TNFalpha and PMA. E-selectin was also upregulated by 6 h with TNFalpha but not significantly with PMA. TNFalpha induced CD44 expression within 4 h, but PMA not significantly up to 6 h. However, specific binding of [125I]hyaluronan to Ea.hy.926 cells was increased by PMA-stimulation at 4 h. Neutrophil adhesion to PMA-stimulated Ea.hy.926 HUVECs was inhibited in a concentration dependent fashion by both anti-ICAM-1 and hyaluronan (1 ng/ml-10 microg/ml) at 4 h. At 1 mg/ml adhesion was stimulated by hyaluronan. Hyaluronan had no effect on neutrophil adhesion to resting Ea.hy.926 cells. Hyaluronan (25 mg/kg, i.v.) inhibited cell adhesion to FMLP-stimulated post capillary venules of the hamster cheek pouch, whilst leaving cell rolling unaffected. CONCLUSIONS: These results show that hyaluronan, at concentrations below those where intra-molecular associations occur, binds selectively to stimulated endothelial cells and inhibits neutrophil adhesion in vitro and in vivo via a mechanism which may involve molecules other than CD44, such as ICAM-1.

Animals↗
PubMed2004

Annexin 1 and neutrophil apoptosis.

ANXA1 (annexin 1), a member of the 'annexin' family of calcium- and phospholipid-binding proteins, was originally identified as an endogenous mediator of the anti-inflammatory actions of glucocorticoids. However, this protein exerts multiple inhibitory effects on the host inflammatory response, including a preferential regulation of the adhesion step of blood-borne neutrophil within the microenvironment of an inflamed vasculature. It is now emerging that ANXA1 is endowed with other roles, since the protein is abundant in inflammatory exudates as it is produced and released by the extravasated neutrophil. In the present paper, we review the novel proapoptotic effect of ANXA1 and discuss its potential with respect to the pathophysiology of inflammation and leucocyte recruitment.

Animals↗
PubMed2003

Generation of innovative anti-inflammatory and anti-arthritic glucocorticoid derivatives that release NO: the nitro-steroids.

Addition to the prednisolone structure of a chemical moiety (linker+nitric ester) that releases NO species yielded a novel glucocorticoid (nitro-prednisolone or NCX-1015) with enhanced anti-inflammatory activities. Nitro-prednisolone was much more potent than prednisolone and the derivative devoid of the nitric ester in an acute peritonitis model (higher impact on neutrophil migration and soluble mediator generation) as well as in models of chronic inflammation (air-pouch granuloma and collagen II-induced arthritis). In the collagen II-induced arthritis model, NCX-1015 abrogated the plasma levels of a catabolite of cartilage and bone metabolism, indication of a disease modifying action. In an in vitro assay of bone resorption, NCX-1015 did not activate osteoclast activity, whereas prednisolone did. This lack of effect of NCX-1015 was chiefly due to NO. We propose that NCX-1015 is the prototype of a new class of glucocorticoids, the nitro-steroids, endowed with enhanced anti-inflammatory properties and reduced side effects. These and other experimental observations here reviewed may prompt the assessment of the clinical impact of the nitro-steroids on rheumatoid arthritis and inflammatory bowel disease.

Amino Acids↗
PubMed2002

Stromal cell-derived factor 1 (CXCL12) induces monocyte migration into human synovium transplanted onto SCID Mice.

OBJECTIVE: The mechanisms by which monocyte/macrophage cells migrate to the joint involve a series of integrated adhesion and signaling events in which chemokines and their receptors are strongly implicated. This study was undertaken to investigate the hypothesis that stromal cell-derived factor 1 (SDF-1), a CXC chemokine (CXCL12), plays a critical role in monocyte/macrophage localization to synovium. METHODS: SDF-1 and CXC receptor 4 (CXCR4) expression in rheumatoid arthritis (RA) and osteoarthritis synovium and graft SDF-1, tumor necrosis factor alpha (TNF alpha), and human and murine vascular markers were examined by immunohistochemistry and double-immunofluorescence. The functional capacity of SDF-1 to modulate monocyte migration into joints was investigated by examining the localization of pro-myelomonocytic U937 cells into synovial tissue transplanted into SCID mice. SDF-1, TNF alpha, or saline was injected into graft sites and response determined by the number of fluorescently labeled U937 cells (injected intravenously) detected in grafts by ultraviolet microscopy. RESULTS: SDF-1 and CXCR4 were highly expressed in CD68+ cells in the RA synovium. SDF-1 induced U937 cell migration in vitro and in vivo in a dose-dependent manner and, in vivo, SDF-1 was more effective than TNF alpha. In contrast to TNF alpha, SDF-1 did not induce intracellular adhesion molecule 1 in transplant microvasculature. Furthermore, intragraft injection of SDF-1 did not up-regulate TNF alpha, or vice versa. CONCLUSION: This study demonstrates, for the first time, that SDF-1 is functional in vivo when injected into synovial grafts. In addition, SDF-1 is more potent than TNF alpha, and its mechanisms of action appear to be autonomous. Therefore, SDF-1 may be an important TNF-independent molecule involved in the migration to and retention of inflammatory effector cells in the joint.

Aged↗
PubMed2002

Time-dependent expression of annexin 1 in a model of chronic granulomatous inflammation.

OBJECTIVE AND DESIGN: To determine the expression pattern and distribution of the glucocorticoid-inducible protein annexin 1 (ANXA1) in a murine model of chronic granulomatous inflammation. MATERIALS OR SUBJECTS: TO Mouse. TREATMENT: Chronic granulomatous inflammation was induced by injecting into dorsal sub-cutaneous air-pouches in mice, a mixture of croton oil and Freund's complete adjuvant (CO/FCA). METHODS: Western and northern analysis, corticosterone assay, and immunohistochemistry. Statistical analysis was performed using ANOVA followed by Tukey's pair-wise comparisons or Dunnett's multiple comparisons. RESULTS: ANXA1 protein levels changed significantly throughout the 4-week time course, with an initial peak at day 7 and a later elevation at 28 days. ANXA1 mRNA levels peaked at days 1 and 3, with a significant decline at day 7 followed by an upward trend to day 28. Plasma corticosterone measurements taken throughout the time course revealed an increase from 14 days onward, suggesting that corticosterone does not influence ANXA1 expression during the initial stages of the model. Immunogold staining revealed that ANXA1 expression in the inflamed tissue was mainly in extravasated neutrophils, with intact protein (37 kDa) being predominantly observed on the cell membrane. CONCLUSIONS: The pattern of ANXA1 expression indicates that infiltrated neutrophils are responsible for the majority of ANXA1 present both at early and later stages of this model of granulomatous inflammation.

Animals↗
PubMed2002

The annexin-1 knockout mouse: what it tells us about the inflammatory response.

The 37kDa protein annexin 1 (Anx-1; lipocortin 1) is a glucocorticoid-regulated protein that has been implicated in the regulation of phagocytosis, cell signalling and proliferation, and postulated to be a mediator of glucocorticoids action in inflammation and in the control of anterior pituitary hormone release. Immuno-neutralisation or antisense strategies support this hypothesis as they can reverse the effect of glucocorticoids in several systems. We recently generated a line of mice lacking the Anx-1 gene noting that some tissues taken from such animals exhibited an increased expression of several proteins including COX-2 and cPLA2. In models of experimental inflammation, Anx-1(-/-) mice exhibit an exaggerated response and a partial or complete resistance to the anti-inflammatory effects of glucocorticoids. Several other anomalies were noted including abnormal leukocyte adhesion molecule expression, an increased spontaneous migratory behaviour of PMN in Anx-1(-/-) mice and a resistance in Anx-1(-/-) macrophages to glucocorticoid inhibition of superoxide generation. This paper reviews these and other data in the light of the development of the 'second messenger' hypothesis of glucocorticoid action.

Animals↗
PubMed2001

Analysis of the protection afforded by annexin 1 in ischaemia-reperfusion injury: focus on neutrophil recruitment.

Ischaemia-reperfusion injury underlies many of the most important cardiovascular diseases such as myocardial infarction, thrombotic stroke, embolic vascular occlusions and peripheral vascular insufficiency. Neutrophils feature prominently in this inflammatory component of post-ischaemic injury. Experimental therapies, shown to reduce neutrophil-mediated ischaemia-reperfusion injury include neutrophil depletion, direct inhibitors of neutrophil activators, antibodies against neutrophil adhesion molecules and the endothelial adhesion molecules. However, aside from these approaches, it is increasingly recognised that glucocorticoids are potent inhibitors of neutrophil-mediated injury. The anti-inflammatory actions of glucocorticoid include the activation of classical cytoplasmic receptors leading to changes in gene transcription as well as the induction of regulatory proteins, such as annexin 1. Annexin 1 is a potent inhibitor of neutrophil extravasation in vivo. Administration of the annexin 1 or peptides derived from its N-terminal domain, reduce neutrophil extravasation in models of acute inflammation. In addition, as reviewed by this article, annexin 1 protects against ischaemia-reperfusion in the heart and mesenteric microcirculation, as well as in multiple organ failure associated with splanchnic ischaemia-reperfusion. Such findings would suggest annexin 1 is a novel anti-inflammatory agent with a potential for the treatment of cardiovascular pathologies associated with neutrophil activation and recruitment.

Animals↗
PubMed2001

Pharmacological modulation of allergic inflammation in the rat airways and association with mast cell heterogeneity.

Administration of ovalbumin by aerosol to sensitised rats produced a rapid (15 min) protein exudation in different airway tissues, as determined by Evans blue staining. This was associated with marked mast cell degranulation determined by histological examination, with there being no difference between mucosal and connective tissue mast cells. A 5-day administration regimen with compound 48/80 selectively depleted connective tissue mast cell (positive to berberine staining) without modifying ovalbumin-induced plasma protein extravasation. Treatment of rats with dexamethasone (1 mg/kg, -12 h) or nor-dihydroguaiaretic acid (30 mg/kg i.p., -30 min) significantly reduced ovalbumin-induced protein extravasation and preserved mucosal mast cell morphology. Indomethacin (4 mg/kg i.v., -30 min) exerted no effect on either parameter. In conclusion, we propose the mucosal mast cell as a target cell responsible at least partly for the inhibitory actions of known anti-inflammatory drugs. We suggest an involvement of endogenous leukotriene(s), but not prostanoid(s), in mucosal mast cell activation/degranulation.

Administration, Inhalation↗
PubMed2001

The use of lymphocyte function-associated antigen (LFA)-1-deficient mice to determine the role of LFA-1, Mac-1, and alpha4 integrin in the inflammatory response of neutrophils.

After injury or infection, neutrophils rapidly migrate from the circulation into tissues by means of an orderly progression of adhesion receptor engagements. Neutrophils have been previously considered to use selectins exclusively to roll on vessels before an adhesion step mediated by the beta2 integrins, lymphocyte function-associated antigen (LFA)-1, and Mac-1. Here we use LFA-1(-/-) mice, function blocking monoclonal antibodies, and intravital microscopy to investigate the roles of LFA-1, Mac-1, and alpha4 integrins in neutrophil recruitment in vivo. For the first time, we show that LFA-1 makes a contribution to neutrophil rolling by stabilizing the transient attachment or tethering phase of rolling. In contrast, Mac-1 does not appear to be important for either rolling or firm adhesion, but instead contributes to emigration from the vessel. Blocking Mac-1 in the presence of LFA-1 significantly reduces emigration, suggesting cooperation between these two integrins. Low levels of alpha4beta1 integrin can be detected on neutrophils from LFA-1(+/+) and (-/-) mice. These cells make use of alpha4beta1 during the rolling phase, particularly in the absence of LFA-1. Thus LFA-1 and alpha4beta1, together with the selectins, are involved in the rolling phase of neutrophil recruitment, and, in turn, affect the later stages of the transmigration event.

Animals↗
PubMed2001

Enhanced serum glucocorticoid levels mediate the reduction of serosal mast cell numbers in diabetic rats.

Rats turned diabetic by treatment with alloxan exhibit a significant reduction in serosal mast cell numbersin parallel with decreased insulin levels in the plasma. Our aim was to investigate the putative involvement of endogenous glucocorticoid hormone in this phenomenon. The findings indicated that rats treated with alloxan responded with an increase in levels of serum corticosterone concomitantly with decreased mast cell numbers in the pleural space. We found that either surgical bilateral adrenalectomy or pretreatment with the steroid antagonist RU 486 (20 mg/kg, i.p.) impaired the drop in pleural mast cell counts in alloxinated rats. Administration of insulin (15 U/kg) prevented the increase in corticosterone levels and restored pleural mast cell levels in diabetic animals. In addition, treatment of naive rats with corticosterone (0.5 mg/kg, s.c.) or dexamethasone (0.1 mg/kg, s.c.), for 3 consecutive days, led to a reduction in the number of mast cells recovered from the pleural cavity as noted in diabetic animals. In contrast, insulin reduced serum corticosterone levels and induced a significant elevation in pleural mast cell numbers in naive rats. We conclude that there is a causative relationship between increased levels of glucocorticoids and down-regulation of mast cell numbers associated with the diabetic state, both phenomena clearly sensitive to insulin.

Adrenalectomy↗
PubMed2001

Mechanism of reaction of melatonin with human myeloperoxidase.

Recently, it was suggested that melatonin (N-acetyl-5-methoxytryptamine) is oxidized by activated neutrophils in a reaction most probably involving myeloperoxidase (Biochem. Biophys. Res. Commun. (2000) 279, 657-662). Myeloperoxidase (MPO) is the most abundant protein of neutrophils and is involved in killing invading pathogens. To clarify if melatonin is a substrate of MPO, we investigated the oxidation of melatonin by its redox intermediates compounds I and II using transient-state spectral and kinetic measurements at 25 degrees C. Spectral and kinetic analysis revealed that both compound I and compound II oxidize melatonin via one-electron processes. The second-order rate constant measured for compound I reduction at pH 7 and pH 5 are (6.1 +/- 0.2) x 10(6) M(-1) s(-1) and (1.0 +/- 0.08) x 10(7) M(-1) s(-1), respectively. The rates for the one-electron reduction of compound II back to the ferric enzyme are (9.6 +/- 0.3) x 10(2) M(-1) s(-1) (pH 7) and (2.2 +/- 0.1) x 10(3) M(-1) s(-1) (pH 5). Thus, melatonin is a much better electron donor for compound I than for compound II. Steady-state experiments showed that the rate of oxidation of melatonin is dependent on the H(2)O(2) concentration, is not affected by superoxide dismutase, and is quickly terminated by sodium cyanide. Melatonin can markedly inhibit the chlorinating activity of MPO at both pH 7 and pH 5. The implication of these findings in the activated neutrophil is discussed.

Chlorides↗
PubMed2001

Morphological alteration of peritoneal mast cells and macrophages in the mouse peritoneal cavity during the early phases of an allergic inflammatory reaction.

We investigated the presence of mast cell granules in macrophages following an in vivo model of an allergic reaction. Injection of ovalbumin (100 microg) into the peritoneal cavity of sensitised mice produced a rapid (within 2 h) influx of neutrophils followed by a slower (after >4 h) eosinophil migration. Ovalbumin treatment induced a high incidence (approximately 50%) of mast cell degranulation compared to control phosphated-buffered saline-treated mice. The majority (approximately 90%) of peritoneal macrophages contained mast cell granules as early as 2 h post-ovalbumin, with lower values at later time-points, as determined by staining with Toluidine blue and Berberine sulphate. This was confirmed by electron microscopy which enabled us to identify the complex mast cell granule sub-structural components in macrophage phagosomes. In conclusion, we used histochemical and ultrastructural analyses to show that mast cell granules become internalised with macrophages during the early stages of an experimental allergic reaction.

Animals↗
PubMed2001

Anti-inflammatory effects of a novel, potent inhibitor of poly (ADP-ribose) polymerase.

OBJECTIVE AND DESIGN: Oxygen- and nitrogen-derived free radicals and oxidants play an important role in the pathogenesis of various forms of inflammation. Recent work emphasizes the importance of oxidant-induced DNA strand breakage and activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) in the pathogenesis of various inflammatory diseases. We have recently demonstrated the efficacy of PJ34, a novel, potent phenanthridinone derivative PARP inhibitor, in rodent models of diabetic vascular dysfunction and stroke. Here we tested the efficacy of PARP inhibition in various models of local inflammation in rodents. MATERIALS AND METHODS: PJ34 (at doses of 0.03-30 mg/kg) was tested in rats and mice subjected to standard models of inflammation, with relevant parameters of inflammation measured using standard methods. RESULTS: PJ34 treatment (s.c, i.p. and i.v.) dose-dependently suppressed neutrophil infiltration and nitric oxide (but not KC and IL-1beta) production in peritonitis. In a model of systemic endotoxemia, PJ34 pretreatment significantly reduced plasma levels of TNF-alpha, IL-1beta and nitrite/nitrate (breakdown products of nitric oxide) production. PJ34 treatment (oral gavage) induced a significant suppression of the inflammatory response in dextran sulfate colitis, multiple low dose streptozotocin diabetes and cyclophosphamide-accelerated autoimmune diabetes in the non-obese diabetic mice, and reduced the degree of mononuclear cell infiltration into the iris in an endotoxin-induced uveitis model. Delaying the start of PJ34 administration in the colitis model conferred significant protective effects, while in the arthritis model the post-treatment paradigm lacked protective effects. CONCLUSIONS: PJ34 provides significant, dose-dependent, anti-inflammatory effects in a variety of local inflammation models. Some of its actions are maintained in the post-treatment regimen and/or after discontinuation of treatment. We conclude that PARP inhibition offers a powerful means for reducing the severity of various forms of local inflammatory responses.

Adenosine Triphosphate↗
PubMed2001

Cytokine modulation of liver annexin 1 expression during experimental endotoxemia.

Annexin 1 (ANXA1) is a calcium-binding protein endowed with anti-inflammatory properties. Using an extra-hepatic system, we showed that interleukin (IL)-6 regulates ANXA1 expression at the transcriptional level. The purpose of this study was to determine whether ANXA1 synthesis was modulated by IL-6 during experimental inflammation. We have compared liver ANXA1 expression during systemic and localized inflammatory reaction, using lipopolysaccharide (LPS) and turpentine. LPS treatment strongly induced ANXA1 expression in the liver of wild-type (WT) animals (+600%) whereas a modest increase (+60%) was measured in IL-6 knockout (KO) animals. Turpentine treatment did not affect the expression of ANXA1 in either animal type. LPS enhanced serum corticosteroid levels equally in WT and IL-6 KO mice, whereas higher tumor necrosis factor (TNF)-alpha and IL-1beta levels were released in IL-6 KO animals. Injection of mouse recombinant IL-6 to IL-6 KO animals before LPS or TNF-alpha challenge, replenished ANXA1 liver synthesis to that of WT animals. Exogenous ANXA1 but not ANXA5, administered to IL-6 KO mice before LPS challenge inhibited TNF-alpha release. We propose that ANXA1 acts as a novel acute phase protein, which is controlled in the liver by TNF-alpha and IL-6, and which may contribute to the resolution of systemic endotoxemia through a negative feedback on TNF-alpha release.

Animals↗