Publications by authors named "Francesco Colotta"

27 Publications

  • Page 1 of 1

Modulation of inflammatory and immune responses by vitamin D.

J Autoimmun 2017 Dec 18;85:78-97. Epub 2017 Jul 18.

DiaSorin Inc, Stillwater, MN, USA.

Vitamin D (VitD) is a prohormone most noted for the regulation of calcium and phosphate levels in circulation, and thus of bone metabolism. Inflammatory and immune cells not only convert inactive VitD metabolites into calcitriol, the active form of VitD, but also express the nuclear receptor of VitD that modulates differentiation, activation and proliferation of these cells. In vitro, calcitriol upregulates different anti-inflammatory pathways and downregulates molecules that activate immune and inflammatory cells. Administration of VitD has beneficial effects in a number of experimental models of autoimmune disease. Epidemiologic studies have indicated that VitD insufficiency is frequently associated with immune disorders and infectious diseases, exacerbated by increasing evidence of suboptimal VitD status in populations worldwide. To date, however, most interventional studies in human inflammatory and immune diseases with VitD supplementation have proven to be inconclusive. One of the reasons could be that the main VitD metabolite measured in these studies was the 25-hydroxyVitD (25OHD) rather than its active form calcitriol. Although our knowledge of calcitriol as modulator of immune and inflammatory reactions has dramatically increased in the past decades, further in vivo and clinical studies are needed to confirm the potential benefits of VitD in the control of immune and inflammatory conditions.
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http://dx.doi.org/10.1016/j.jaut.2017.07.007DOI Listing
December 2017

A low plasma 1,25(OH) vitamin D/PTH (1-84) ratio predicts worsening of renal function in patients with chronic heart failure.

Int J Cardiol 2016 Dec 10;224:220-225. Epub 2016 Sep 10.

Department of Cardiovascular Research, IRCCS-Istituto di Ricerche Famacologiche Mario Negri, Milan, Italy.

Background: Dysregulation of the vitamin D system promotes renal dysfunction and has direct detrimental effects on the heart. Progressive deterioration of renal function is common in patients with chronic heart failure (HF) and is invariably associated with unfavorable outcomes which can be improved by early identification and timely interventions. We examined the relation between two plasma markers of vitamin D metabolism and worsening of renal function (WRF) in a large cohort of patients with chronic HF.

Methods: Plasma levels of 1,25-dihydroxyvitamin D (1,25(OH)D) and parathyroid hormone PTH (1-84) were measured in 1237 patients with clinical evidence of chronic and stable HF enrolled in the multicentre GISSI-HF trial and followed for 3.9years. We examined the relation of 1,25(OH)D, PTH(1-84), and their ratio with WRF, defined as first increase in serum creatinine concentration ≥0.3mg/dL and ≥25% at two consecutive measurements at any time during the study.

Results: Lower 1,25(OH)D/PTH(1-84) ratio was associated with a higher baseline serum concentration of creatinine, winter season, female sex and older age; 335 patients (29.6%) experienced an episode of WRF. After adjustment, a lower 1,25(OH)D/PTH(1-84) ratio remained significantly associated with a higher risk of WRF (HR=0.75 [0.62-0.90], p=0.002) and correctly reclassified events. This ratio also independently predicted mortality and admission to hospital for cardiovascular reasons.

Conclusions: The plasma 1,25(OH)D/PTH(1-84) ratio is a promising indicator of future risk of deterioration of renal function in patients with chronic HF and mild renal impairment, that may serve to optimize therapies and improve outcomes.
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http://dx.doi.org/10.1016/j.ijcard.2016.09.014DOI Listing
December 2016

Simple, rapid and accurate molecular diagnosis of acute promyelocytic leukemia by loop mediated amplification technology.

Oncoscience 2015 27;2(1):50-8. Epub 2014 Dec 27.

DiaSorin SpA, Gerenzano (VA), Italy.

The diagnostic work-up of acute promyelocytic leukemia (APL) includes the cytogenetic demonstration of the t(15;17) translocation and/or the PML-RARA chimeric transcript by RQ-PCR or RT-PCR. This latter assays provide suitable results in 3-6 hours. We describe here two new, rapid and specific assays that detect PML-RARA transcripts, based on the RT-QLAMP (Reverse Transcription-Quenching Loop-mediated Isothermal Amplification) technology in which RNA retrotranscription and cDNA amplification are carried out in a single tube with one enzyme at one temperature, in fluorescence and real time format. A single tube triplex assay detects bcr1 and bcr3 PML-RARA transcripts along with GUS housekeeping gene. A single tube duplex assay detects bcr2 and GUSB. In 73 APL cases, these assays detected in 16 minutes bcr1, bcr2 and bcr3 transcripts. All 81 non-APL samples were negative by RT-QLAMP for chimeric transcripts whereas GUSB was detectable. In 11 APL patients in which RT-PCR yielded equivocal breakpoint type results, RT-QLAMP assays unequivocally and accurately defined the breakpoint type (as confirmed by sequencing). Furthermore, RT-QLAMP could amplify two bcr2 transcripts with particularly extended PML exon 6 deletions not amplified by RQ-PCR. RT-QLAMP reproducible sensitivity is 10(-3) for bcr1 and bcr3 and 10(-)2 for bcr2 thus making this assay particularly attractive at diagnosis and leaving RQ-PCR for the molecular monitoring of minimal residual disease during the follow up. In conclusion, PML-RARA RT-QLAMP compared to RT-PCR or RQ-PCR is a valid improvement to perform rapid, simple and accurate molecular diagnosis of APL.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4341464PMC
http://dx.doi.org/10.18632/oncoscience.114DOI Listing
March 2015

Targeting the mitotic checkpoint for cancer therapy with NMS-P715, an inhibitor of MPS1 kinase.

Cancer Res 2010 Dec;70(24):10255-64

Department of Cell Biology-Oncology, Nerviano Medical Sciences, Viale Pasteur 10, Nerviano 20014, Italy.

MPS1 kinase is a key regulator of the spindle assembly checkpoint (SAC), a mitotic mechanism specifically required for proper chromosomal alignment and segregation. It has been found aberrantly overexpressed in a wide range of human tumors and is necessary for tumoral cell proliferation. Here we report the identification and characterization of NMS-P715, a selective and orally bioavailable MPS1 small-molecule inhibitor, which selectively reduces cancer cell proliferation, leaving normal cells almost unaffected. NMS-P715 accelerates mitosis and affects kinetochore components localization causing massive aneuploidy and cell death in a variety of tumoral cell lines and inhibits tumor growth in preclinical cancer models. Inhibiting the SAC could represent a promising new approach to selectively target cancer cells.
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http://dx.doi.org/10.1158/0008-5472.CAN-10-2101DOI Listing
December 2010

Cdc7 kinase inhibitors: 5-heteroaryl-3-carboxamido-2-aryl pyrroles as potential antitumor agents. 1. Lead finding.

J Med Chem 2010 Oct;53(20):7296-315

Nerviano Medical Sciences Srl, Business Unit Oncology, Viale Pasteur 10, 20014 Nerviano, MI, Italy.

Cdc7 serine/threonine kinase is a key regulator of DNA synthesis in eukaryotic organisms. Cdc7 inhibition through siRNA or prototype small molecules causes p53 independent apoptosis in tumor cells while reversibly arresting cell cycle progression in primary fibroblasts. This implies that Cdc7 kinase could be considered a potential target for anticancer therapy. We previously reported that pyrrolopyridinones (e.g., 1) are potent and selective inhibitors of Cdc7 kinase, with good cellular potency and in vitro ADME properties but with suboptimal pharmacokinetic profiles. Here we report on a new chemical class of 5-heteroaryl-3-carboxamido-2-substituted pyrroles (1A) that offers advantages of chemistry diversification and synthetic simplification. This work led to the identification of compound 18, with biochemical data and ADME profile similar to those of compound 1 but characterized by superior efficacy in an in vivo model. Derivative 18 represents a new lead compound worthy of further investigation toward the ultimate goal of identifying a clinical candidate.
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http://dx.doi.org/10.1021/jm100504dDOI Listing
October 2010

Targeting genetic instability in cancer cells.

Curr Drug Targets 2010 Oct;11(10):1293-5

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http://dx.doi.org/10.2174/1389450111007011293DOI Listing
October 2010

Dual targeting of CDK and tropomyosin receptor kinase families by the oral inhibitor PHA-848125, an agent with broad-spectrum antitumor efficacy.

Mol Cancer Ther 2010 Aug 3;9(8):2243-54. Epub 2010 Aug 3.

Cell Biology Department, BU Oncology, Nerviano Medical Sciences, v.le Pasteur 10, Nerviano, Milan 20014, Italy.

Altered expression and activity of cyclin-dependent kinase (CDK) and tropomyosin receptor kinase (TRK) families are observed in a wide variety of tumors. In those malignancies with aberrant CDK activation, the retinoblastoma protein (pRb) pathway is deregulated, leading to uncontrolled cell proliferation. Constitutive activation of TRKs is instead linked to cancer cell survival and dissemination. Here, we show that the novel small-molecule PHA-848125, a potent dual inhibitor of CDKs and TRKs, possesses significant antitumor activity. The compound inhibits cell proliferation of a wide panel of tumoral cell lines with submicromolar IC(50). PHA-848125-treated cells show cell cycle arrest in G(1) and reduced DNA synthesis, accompanied by inhibition of pRb phosphorylation and modulation of other CDK-dependent markers. The compound additionally inhibits phosphorylation of TRKA and its substrates in cells, which functionally express this receptor. Following oral administration, PHA-848125 has significant antitumor activity in various human xenografts and carcinogen-induced tumors as well as in disseminated primary leukemia models, with plasma concentrations in rodents in the same range as those found active in inhibiting cancer cell proliferation. Mechanism of action was also confirmed in vivo as assessed in tumor biopsies from treated mice. These results show that the dual CDK-TRK inhibitor PHA-848125 has the potential for being a novel and efficacious targeted drug for cancer treatment.
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http://dx.doi.org/10.1158/1535-7163.MCT-10-0190DOI Listing
August 2010

Targeting cell division cycle 7 kinase: a new approach for cancer therapy.

Clin Cancer Res 2010 Sep 20;16(18):4503-8. Epub 2010 Jul 20.

Nerviano Medical Sciences Oncology, Nerviano, Milan, Italy.

The cell division cycle 7 (Cdc7) is a serine-threonine kinase, originally discovered in budding yeast, required to initiate DNA replication. Human Cdc7 phosphorylates the minichromosome maintenance protein 2 (Mcm2), a component of the DNA replicative helicase needed for genome duplication. Inhibition of Cdc7 in cancer cells impairs progression through S phase, inducing a p53-independent apoptotic cell death, whereas in normal cells, it does not affect cell viability. Small molecule compounds able to interfere with Cdc7 activity have been identified and shown to be effective in controlling tumor growth in animal models. Two Cdc7 inhibitors are currently in phase I clinical development. Inhibition of Cdc7 kinase activity in cancer cells restricts DNA replication and induces apoptotic cell death by an unprecedented molecular mechanism of action.
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http://dx.doi.org/10.1158/1078-0432.CCR-10-0185DOI Listing
September 2010

Therapeutic efficacy of the pan-cdk inhibitor PHA-793887 in vitro and in vivo in engraftment and high-burden leukemia models.

Exp Hematol 2010 Apr 16;38(4):259-269.e2. Epub 2010 Feb 16.

Nerviano Medical Sciences Srl, Business Unit Oncology, Nerviano, Italy.

Objective: The aim of the work was to determine and characterize, in vitro and in vivo, the therapeutic activity of PHA-793887, a new potent pan-cdk inhibitor, in the context of hematopoietic neoplasms.

Materials And Methods: Thirteen leukemic cell lines bearing different cytogenetic abnormalities and normal hematopoietic cells were used in cytotoxicity and colony assays. The drug activity at the molecular level was analyzed by Western blotting. PHA-793887 was also tested in vivo in several leukemia xenograft models.

Results: PHA-793887 was cytotoxic for leukemic cell lines in vitro, with IC(50) ranging from 0.3 to 7 microM (mean: 2.9 microM), regardless of any specific chromosomal aberration. At these doses, the drug was not cytotoxic for normal unstimulated peripheral blood mononuclear cells or CD34(+) hematopoietic stem cells. Interestingly, in colony assays PHA-793887 showed very high activity against leukemia cell lines, with an IC(50) <0.1 microM (mean: 0.08 microM), indicating that it has efficient and prolonged antiproliferative activity. PHA-793887 induced cell-cycle arrest, inhibited Rb and nucleophosmin phosphorylation, and modulated cyclin E and cdc6 expression at low doses (0.2-1 microM) and induced apoptosis at the highest dose (5 microM). It was also effective in vivo in both subcutaneous xenograft and primary leukemic disseminated models that better mimic naturally occurring human disease. Interestingly, in one disseminated model derived from a relapsed Philadelphia-positive acute lymphoid leukemia patient, PHA-793887 showed strong therapeutic activity also when treatment was started after establishment of high disease burden.

Conclusions: We conclude that PHA-793887 has promising therapeutic activity against acute leukemias in vitro and in vivo.
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http://dx.doi.org/10.1016/j.exphem.2010.02.004DOI Listing
April 2010

Identification of N,1,4,4-tetramethyl-8-{[4-(4-methylpiperazin-1-yl)phenyl]amino}-4,5-dihydro-1H-pyrazolo[4,3-h]quinazoline-3-carboxamide (PHA-848125), a potent, orally available cyclin dependent kinase inhibitor.

J Med Chem 2009 Aug;52(16):5152-63

Business Unit Oncology, Nerviano Medical Sciences Srl, Viale Pasteur 10, 20014 Nerviano (MI), Italy.

The discovery of a novel class of inhibitors of cyclin dependent kinases (CDKs) is described. Starting from compound 1, showing good potency as inhibitor of CDKs but being poorly selective against a panel of serine-threonine and tyrosine kinases, new analogues were synthesized. Enhancement in selectivity, antiproliferative activity against A2780 human ovarian carcinoma cells, and optimization of the physical properties and pharmacokinetic profile led to the identification of highly potent and orally available compounds. Compound 28 (PHA-848125), which in the preclinical xenograft A2780 human ovarian carcinoma model showed good efficacy and was well tolerated upon repeated daily treatments, was identified as a drug candidate for further development. Compound 28 is currently undergoing phase I and phase II clinical trials.
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http://dx.doi.org/10.1021/jm9006559DOI Listing
August 2009

Cancer-related inflammation, the seventh hallmark of cancer: links to genetic instability.

Carcinogenesis 2009 Jul 25;30(7):1073-81. Epub 2009 May 25.

Nerviano Medical Sciences, Nerviano, Milan, Italy.

Inflammatory conditions in selected organs increase the risk of cancer. An inflammatory component is present also in the microenvironment of tumors that are not epidemiologically related to inflammation. Recent studies have begun to unravel molecular pathways linking inflammation and cancer. In the tumor microenvironment, smoldering inflammation contributes to proliferation and survival of malignant cells, angiogenesis, metastasis, subversion of adaptive immunity, reduced response to hormones and chemotherapeutic agents. Recent data suggest that an additional mechanism involved in cancer-related inflammation (CRI) is induction of genetic instability by inflammatory mediators, leading to accumulation of random genetic alterations in cancer cells. In a seminal contribution, Hanahan and Weinberg [(2000) Cell, 100, 57-70] identified the six hallmarks of cancer. We surmise that CRI represents the seventh hallmark.
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http://dx.doi.org/10.1093/carcin/bgp127DOI Listing
July 2009

Anticancer drug discovery and development.

Adv Exp Med Biol 2008 ;610:19-42

Nerviano Medical Sciences, Nerviano (Milan), Italy.

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http://dx.doi.org/10.1007/978-0-387-73898-7_3DOI Listing
July 2008

Crucial pathophysiological role of CXCR2 in experimental ulcerative colitis in mice.

J Leukoc Biol 2007 Nov 26;82(5):1239-46. Epub 2007 Jul 26.

Department of Preclinical Pharmacology, Dompé pha r ma s p a, Via Campo di Pile, 67100, L'Aquila, Italy.

Polymorphonuclear leukocyte infiltration and activation into colonic mucosa are believed to play a pivotal role in mediating tissue damage in human ulcerative colitis (UC). Ligands of human CXC chemokine receptor 1 and 2 (CXCR1/R2) are chemoattractants of PMN, and high levels were found in the mucosa of UC patients. To investigate the pathophysiological role played by CXCR2 in experimental UC, we induced chronic experimental colitis in WT and CXCR2(-/-) mice by two consecutive cycles of 4% dextran sulfate sodium administration in drinking water. In wild-type (WT) mice, the chronic relapsing of DSS-induced colitis was characterized by clinical signs and histopathological findings that closely resemble human disease. CXCR2(-/-) mice failed to show PMN infiltration into the mucosa and, consistently with a key role of PMN in mediating tissue damage in UC, showed limited signs of mucosal damage and reduced clinical symptoms. Our data demonstrate that CXCR2 plays a key pathophysiological role in experimental UC, suggesting that CXCR2 activation may represent a relevant pharmacological target for the design of novel pharmacological treatments in human UC.
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http://dx.doi.org/10.1189/jlb.0207118DOI Listing
November 2007

Placental growth factor-1 potentiates hematopoietic progenitor cell mobilization induced by granulocyte colony-stimulating factor in mice and nonhuman primates.

Stem Cells 2007 Jan 28;25(1):252-61. Epub 2006 Sep 28.

C. Gandini Bone Marrow Transplantation Unit, Istituto Nazionale Tumori, Via Venezian, 1, 20133 Milano, Italy.

The complex hematopoietic effects of placental growth factor (PlGF) prompted us to test in mice and nonhuman primates the mobilization of peripheral blood progenitor cells (PBPCs) elicited by recombinant mouse PlGF-2 (rmPlGF-2) and recombinant human PlGF-1 (rhPlGF-1). PBPC mobilization was evaluated by assaying colony-forming cells (CFCs), high-proliferative potential-CFCs (HPP-CFCs), and long-term culture-initiating cells (LTC-ICs). In mice, both rmPlGF-2 and rhPlGF-1 used as single agents failed to mobilize PBPCs, whereas the combination of rhPlGF-1 and granulocyte colony-stimulating factor (rhG-CSF) increased CFCs and LTC-ICs per milliliter of blood by four- and eightfold, respectively, as compared with rhG-CSF alone. rhPlGF-1 plus rhG-CSF significantly increased matrix metalloproteinase-9 plasma levels over rhG-CSF alone, suggesting a mechanistic explanation for rhPlGF-1/rhG-CSF synergism. In rhesus monkeys, rhPlGF-1 alone had no mobilization effect, whereas rhPlGF-1 (260 microg/kg per day) plus rhG-CSF (100 microg/kg per day) increased rhG-CSF-elicited mobilization of CFCs, HPP-CFCs, and LTC-ICs per milliliter of blood by 5-, 7-, and 15-fold, respectively. No specific toxicity was associated with the administration of rhPlGF-1 alone or in combination. In conclusion, our data demonstrate that rhPlGF-1 significantly increases rhG-CSF-elicited hematopoietic mobilization and provide a preclinical rationale for evaluating rhPlGF-1 in the clinical setting.
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http://dx.doi.org/10.1634/stemcells.2006-0020DOI Listing
January 2007

Requirements for the different cysteines in the chemotactic and desensitizing activity of human thioredoxin.

Antioxid Redox Signal 2005 Sep-Oct;7(9-10):1189-94

Dompe' Research Center and Consorzio Biolaq, L'Aquila, Italy.

Thioredoxin (Trx) is a protein disulfide oxidoreductase that can be secreted and act as a chemoattractant for leukocytes. Like chemokines, it causes desensitization of monocytes against its chemotactic activity and that of monocyte chemoattractant protein-1 (MCP-1). To investigate the role of the redox properties of Trx, and particularly of some of its five cysteines, in its chemotactic and desensitizing action, we tested different mutants, including Trx80, a truncated form, and various mutants lacking specific cysteines: Trx C62S/C73S and the redox-inactive mutant Trx C32S/C35S. Of the mutants, only Trx80 maintained the chemotactic activity of wild-type Trx toward both monocytes and polymorphonuclear neutrophils, all of them desensitized monocytes against wild-type Trx or MCP-1, but not chemotactic peptide formyl-methionyl-leucil peptide. These data indicate that different redox-active cysteines are important for Trx chemotactic action, whereas its desensitizing action does not have these requirements, suggesting a redox-independent mechanism.
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http://dx.doi.org/10.1089/ars.2005.7.1189DOI Listing
January 2006

2-Arylpropionic CXC chemokine receptor 1 (CXCR1) ligands as novel noncompetitive CXCL8 inhibitors.

J Med Chem 2005 Jun;48(13):4312-31

Dompé Research and Development, Dompé S.p.A., via Campo di Pile, 67100, L'Aquila, Italy.

The CXC chemokine CXCL8/IL-8 plays a major role in the activation and recruitment of polymorphonuclear (PMN) cells at inflammatory sites. CXCL8 activates PMNs by binding the seven-transmembrane (7-TM) G-protein-coupled receptors CXC chemokine receptor 1 (CXCR1) and CXC chemokine receptor 2 (CXCR2). (R)-Ketoprofen (1) was previously reported to be a potent and specific noncompetitive inhibitor of CXCL8-induced human PMNs chemotaxis. We report here molecular modeling studies showing a putative interaction site of 1 in the TM region of CXCR1. The binding model was confirmed by alanine scanning mutagenesis and photoaffinity labeling experiments. The molecular model driven medicinal chemistry optimization of 1 led to a new class of potent and specific inhibitors of CXCL8 biological activity. Among these, repertaxin (13) was selected as a clinical candidate drug for prevention of post-ischemia reperfusion injury.
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http://dx.doi.org/10.1021/jm049082iDOI Listing
June 2005

Inhibition of the chemokine receptor CXCR2 prevents kidney graft function deterioration due to ischemia/reperfusion.

Kidney Int 2005 May;67(5):1753-61

Transplant Research Center Chiara Cucchi de Alessandri e Gilberto Crespi Mario Negri Institute for Pharmacological Research, Villa Camozzi, Ranica, Bergamo, Italy.

Background: Ischemia/reperfusion (I/R) injury after organ transplantation is a major cause of delayed graft function. Following I/R, locally produced CXC chemokines attract and activate granulocytes, which in turn promote graft damage.

Methods: We examined the involvement of granulocyte recruitment via the CXCR2 pathway in a rat model of 4 hours cold ischemia followed by kidney transplantation. Serum creatinine and intragraft granulocyte infiltration were monitored in the early phase posttransplant. A CXCR2 inhibitor, repertaxin, was given to recipients before transplantation (at -24 hours or -8 hours or -2 hours), immediately before reperfusion and 2 hours later.

Results: An increase of granulocyte chemoattractant CINC-1/interleukin-8 (IL-8) mRNA expression after I/R both in syngeneic and allogeneic transplantation was associated with a marked infiltration of granulocytes in renal tissue. In syngeneic transplantation, Lewis rats given 15 mg/kg repertaxin 24 hours before surgery had granulocyte graft infiltration and serum creatinine levels significantly reduced in respect to vehicle-treated animals. Intermediate effects were observed with 5 mg/kg, whereas the dose of 30 mg/kg had toxic effects. We found that reducing the pretreatment time to 8 hours before surgery was still effective. Prevention of granulocyte infiltration and serum creatinine increase was also obtained in allogeneic transplantation, when Brown Norway recipients of Lewis kidneys were given 15 mg/kg repertaxin starting 8 hours before surgery.

Conclusion: Repertaxin treatment of the recipient animal was effective in preventing granulocyte infiltration and renal function impairment both in syngeneic and in allogeneic settings. The possibility to modulate I/R injury in this rat model opens new perspectives for preventing posttransplant delayed graft function in humans.
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http://dx.doi.org/10.1111/j.1523-1755.2005.00272.xDOI Listing
May 2005

Neuroprotection with the CXCL8 inhibitor repertaxin in transient brain ischemia.

Cytokine 2005 May;30(3):125-31

Mario Negri Institute for Pharmacological Research, Milan, Italy.

Infiltration of polymorphonuclear neutrophils (PMNs) is thought to play a role in ischemic brain damage. The present study investigated the effect of repertaxin, a new noncompetitive allosteric inhibitor for the receptors of the inflammatory chemokine CXC ligand 8 (CXCL8)/interleukin-8 (IL-8), on PMN infiltration and tissue injury in rats. Cerebral ischemia was induced by permanent or transient occlusion of the middle cerebral artery and myeloperoxidase activity, a marker of PMN infiltration, and infarct volume were evaluated 24 h later. Repertaxin (15 mg/kg) was administered systemically at the time of ischemia and every 2 h for four times. In permanent ischemia repertaxin reduced PMN infiltration by 40% in the brain cortex but did not limit tissue damage. In transient ischemia (90-min ischemia followed by reperfusion), repertaxin inhibited PMN infiltration by 54% and gave 44% protection from tissue damage. Repertaxin had anti-inflammatory and neuroprotective effects also when given at reperfusion and even at 2 h of reperfusion. The protective effect of repertaxin did not interfere with brain levels of the chemokine. Since the PMN infiltration and its inhibition by repertaxin were comparable in the two models we conclude that reperfusion induces PMN activation, and inhibition of CXCL8 by repertaxin might be of pharmacological interest in transient ischemia.
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http://dx.doi.org/10.1016/j.cyto.2004.12.014DOI Listing
May 2005

Inhibition of interleukin-8 (CXCL8/IL-8) responses by repertaxin, a new inhibitor of the chemokine receptors CXCR1 and CXCR2.

Biochem Pharmacol 2005 Feb 9;69(3):385-94. Epub 2004 Dec 9.

Dompé S.p.A. Research Center, L'Aquila, Italy.

Repertaxin is a new non-competitive allosteric blocker of interleukin-8 (CXCL8/IL-8) receptors (CXCR1/R2), which by locking CXCR1/R2 in an inactive conformation prevents receptor signaling and human polymorphonuclear leukocyte (PMN) chemotaxis. Given the unique mode of action of repertaxin it was important to examine the ability of repertaxin to inhibit a wide range of biological activities induced by CXCL8 in human leukocytes. Our results show that repertaxin potently and selectively blocked PMN adhesion to fibrinogen and CD11b up-regulation induced by CXCL8. Reduction of CXCL8-mediated PMN adhesion by repertaxin was paralleled by inhibition of PMN activation including secondary and tertiary granule release and pro-inflammatory cytokine production, whereas PMN phagocytosis of Escherichia coli bacteria was unaffected. Repertaxin also selectively blocked CXCL8-induced T lymphocyte and natural killer (NK) cell migration. These data suggest that repertaxin is a potent and specific inhibitor of a wide range of CXCL8-mediated activities related to leukocyte recruitment and functional activation in inflammatory sites.
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http://dx.doi.org/10.1016/j.bcp.2004.10.007DOI Listing
February 2005

Repertaxin, a novel inhibitor of rat CXCR2 function, inhibits inflammatory responses that follow intestinal ischaemia and reperfusion injury.

Br J Pharmacol 2004 Sep 9;143(1):132-42. Epub 2004 Aug 9.

Immunopharmacology, Departamento de Bioquímica e Imunologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.

1. Neutrophils are thought to play a major role in the mediation of reperfusion injury. CXC chemokines are known inducers of neutrophil recruitment. Here, we assessed the effects of Repertaxin, a novel low molecular weight inhibitor of human CXCL8 receptor activation, on the local, remote and systemic injuries following intestinal ischaemia and reperfusion (I/R) in the rat. 2. Pre-incubation of rat neutrophils with Repertaxin (10(-11)-10(-6) m) inhibited the chemotaxis of neutrophils induced by human CXCL8 or rat CINC-1, but not that induced by fMLP, PAF or LTB(4), in a concentration-dependent manner. Repertaxin also prevented CXCL8-induced calcium influx but not CXCL8 binding to purified rat neutrophils. 2. In a model of mild I/R injury (30 min of ischaemia and 30 min of reperfusion), Repertaxin dose-dependently (3-30 mg kg(-1)) inhibited the increase in vascular permeability and neutrophil influx. Maximal inhibition occurred at 30 mg kg(-1). 4. Following severe I/R injury (120 min of ischaemia and 120 min of reperfusion), Repertaxin (30 mg kg(-1)) markedly prevented neutrophil influx, the increase in vascular permeability both in the intestine and the lungs. Moreover, there was prevention of haemorrhage in the intestine of reperfused animals. 5. Repertaxin effectively suppressed the increase in tissue (intestine and lungs) and serum concentrations of TNF-alpha and the reperfusion-associated lethality. 6. For comparison, we also evaluated the effects of an anti-CINC-1 antibody in the model of severe I/R injury. Overall, the antibody effectively prevented tissue injury, systemic inflammation and lethality. However, the effects of the antibody were in general of lower magnitude than those of Repertaxin. 7. In conclusion, CINC-1 and possibly other CXC chemokines, acting on CXCR2, have an important role during I/R injury. Thus, drugs, such as Repertaxin, developed to block the function of the CXCR2 receptor may be effective at preventing reperfusion injury in relevant clinical situations.
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http://dx.doi.org/10.1038/sj.bjp.0705862DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1575259PMC
September 2004

Noncompetitive allosteric inhibitors of the inflammatory chemokine receptors CXCR1 and CXCR2: prevention of reperfusion injury.

Proc Natl Acad Sci U S A 2004 Aug 28;101(32):11791-6. Epub 2004 Jul 28.

Dompé, 67100 L'Aquila, Italy.

The chemokine CXC ligand 8 (CXCL8)/IL-8 and related agonists recruit and activate polymorphonuclear cells by binding the CXC chemokine receptor 1 (CXCR1) and CXCR2. Here we characterize the unique mode of action of a small-molecule inhibitor (Repertaxin) of CXCR1 and CXCR2. Structural and biochemical data are consistent with a noncompetitive allosteric mode of interaction between CXCR1 and Repertaxin, which, by locking CXCR1 in an inactive conformation, prevents signaling. Repertaxin is an effective inhibitor of polymorphonuclear cell recruitment in vivo and protects organs against reperfusion injury. Targeting the Repertaxin interaction site of CXCR1 represents a general strategy to modulate the activity of chemoattractant receptors.
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http://dx.doi.org/10.1073/pnas.0402090101DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC511013PMC
August 2004

IL-8 induces a specific transcriptional profile in human neutrophils: synergism with LPS for IL-1 production.

Eur J Immunol 2004 Aug;34(8):2286-92

Centro di Eccellenza per l'Innovazione Diagnostica e Terapeutica, Institute of General Pathology, University of Milan, Milan, Italy.

IL-8 is an inflammatory CXC chemokine involved in neutrophil recruitment and activation in various inflammatory conditions. The transcriptional profile induced by IL-8 in human neutrophils was analyzed using high-density oligonucleotide arrays and compared with that of the prototypic phagocyte activator LPS. As expected, LPS induced a major effect on the cell transcriptome, upregulating 116 (0.93%) and downregulating 70 (0.56%) of the transcripts. IL-8 induced a less profound modulation of the cell transcriptome, with upregulation of 30 (0.25%) and downregulation of 6 (0.04%) of the transcripts. Although the two proinflammatory mediators induced partially overlapping transcriptional profiles (50.0% of IL-8-responsive genes were concordantly regulated by LPS), IL-8 also modulated a significant number of genes unresponsive to LPS, including soluble mediators, membrane receptors, signaling molecules, and regulators of transcription and translation. A set of IL-8-inducible genes was related to cell motility, possibly a strategy to prepare for migration into tissues. Analysis of the IL-8-responsive gene IL-1beta at the protein level revealed that transcript induction was not followed by protein production. Neutrophils stimulated with IL-8, however, showed a significant increase in IL-1beta secretion after subsequent exposure to LPS. Thus, the effect of IL-8 at the transcriptional level could provide a synergistic effect with microbial products for neutrophil activation.
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http://dx.doi.org/10.1002/eji.200324481DOI Listing
August 2004

Key role of proline-rich tyrosine kinase 2 in interleukin-8 (CXCL8/IL-8)-mediated human neutrophil chemotaxis.

Immunology 2004 Apr;111(4):407-15

Dompé S.p.A., L'Aquila, Italy.

The signalling pathways leading to CXCL8/IL-8-induced human neutrophil migration have not been fully characterized. The present study demonstrates that CXCL8 induces tyrosine phosphorylation as well as enzymatic activity of proline-rich tyrosine kinase 2 (Pyk2), a non-receptor protein tyrosine kinase (PTK), in human neutrophils. Induction of Pyk2 tyrosine phosphorylation by CXCL8 is regulated by Src PTK activation, whereas it is unaffected by phosphatidylinositol 3-kinase activation. Inhibition of Pyk2 activation by PP1, a Src PTK inhibitor, is paralleled by the inhibition of CXCL8-mediated neutrophil chemotaxis. Among CXCL8 receptors, Src protein tyrosine kinase activation selectively regulates CXCR1-mediated polymorphonuclear neutrophil (PMN) chemotaxis. Overexpression of PykM, the kinase-dead mutant of Pyk2, blocks CXCL8-induced chemotaxis of HL-60-derived PMN-like cells, thus pinpointing the key role of Pyk2 in CXCL8-induced chemotaxis.
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http://dx.doi.org/10.1111/j.1365-2567.2004.01822.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1782435PMC
April 2004

IL-1 beta scavenging by the type II IL-1 decoy receptor in human neutrophils.

J Immunol 2003 Jun;170(12):5999-6005

Istituto Ricerche Farmacologiche Mario Negri, Milan, Italy.

IL-1 elicits its cellular effects by binding a heterodimeric receptor consisting of IL-1RI and the accessory protein, IL-1RAcPr. In addition, it binds to IL-1RII, which lacking signaling function has been ascribed a decoy role. The fate of the ligand following interaction with the decoy receptor was examined in human polymorphonuclear cells (PMN), which express predominantly (>90%) IL-1RII. Incubation of PMN with IL-1beta results in a rapid decrease in cell surface-associated ligand accompanied by a concomitant increase in internalized IL-1 with 50-60% of IL-1beta located intracellularly within 1 h at 37 degrees C. The use of blocking Abs revealed that IL-1 internalization is mediated exclusively by the decoy receptor. The results of inhibitor analysis demonstrate that internalization requires ATP synthesis and involves clathrin-mediated endocytosis. Following removal of the ligand, the receptor was rapidly re-expressed on the cell surface. Cyclohexamide, a protein synthesis inhibitor, had no effect upon the process, suggesting that the re-expressed receptor was recycled. In addition, human keratinocytes stably transfected with IL-1RII (HaCAT 811) also internalized the IL-1RII with 43% cell surface receptor internalized after 90 min. Immunofluorescence microscopy revealed colocalization of the internalized receptor with wheat germ agglutinin-labeled internalized glycoproteins and early endosome Ag-1, a protein associated with the early endosome compartments, indicative of cellular uptake of IL-1RII by endocytosis. In contrast, little or no internalization was observed in other cells of immune origin. These results suggest that the decoy receptor IL-1RII can act as a scavenger of IL-1, representing a novel autoregulatory mechanism of the IL-1 system.
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http://dx.doi.org/10.4049/jimmunol.170.12.5999DOI Listing
June 2003

Isolation of human Fab fragments against ovarian carcinoma using guided selection.

Methods Mol Biol 2003 ;207:145-59

Istituto Nazionale per lo Studio e la Cura dei Tumori, Department of Experimental Oncology, Unit of Molecular Therapies, Milano, Italy.

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http://dx.doi.org/10.1385/1-59259-334-8:145DOI Listing
May 2003

An HGF-MSP chimera disassociates the trophic properties of scatter factors from their pro-invasive activity.

Nat Biotechnol 2002 May;20(5):488-95

Division of Molecular Oncology, Institute for Cancer Research and Treatment (IRCC), University of Torino Medical School, I-10060 Candiolo, Torino, Italy.

Hepatocyte growth factor (HGF) and macrophage-stimulating protein (MSP) have an intrinsic dual nature: they are trophic cytokines preventing apoptosis on one side and scatter factors promoting invasion on the other. For therapeutic use, their anti-apoptotic activity must be separated from their pro-invasive activity. To this end, we engineered chimeric factors containing selected functional domains of HGF and/or MSP in different combinations, and tested their biological activity. Here we present a chimeric cytokine derived from the alpha-chains of HGF and MSP, named Metron factor 1 for its ability to concomitantly activate the HGF receptor (Met) and the MSP receptor (Ron). We provide evidence that Metron factor 1 prevents apoptosis and stimulates cell proliferation at nanomolar concentrations, but is devoid of any pro-invasive activity. In an in vivo murine model of drug-induced nephrotoxicity, intravenous injection of recombinant Metron factor 1 prevented renal damage and preserved tubular integrity.
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http://dx.doi.org/10.1038/nbt0502-488DOI Listing
May 2002