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1.
Autophagy ; 19(2): 474-504, 2023 02.
Article in English | MEDLINE | ID: mdl-35579620

ABSTRACT

Impaired mitophagy is a primary pathogenic event underlying diverse aging-associated diseases such as Alzheimer and Parkinson diseases and sarcopenia. Therefore, augmentation of mitophagy, the process by which defective mitochondria are removed, then replaced by new ones, is an emerging strategy for preventing the evolvement of multiple morbidities in the elderly population. Based on the scaffold of spermidine (Spd), a known mitophagy-promoting agent, we designed and tested a family of structurally related compounds. A prototypic member, 1,8-diaminooctane (VL-004), exceeds Spd in its ability to induce mitophagy and protect against oxidative stress. VL-004 activity is mediated by canonical aging genes and promotes lifespan and healthspan in C. elegans. Moreover, it enhances mitophagy and protects against oxidative injury in rodent and human cells. Initial structural characterization suggests simple rules for the design of compounds with improved bioactivity, opening the way for a new generation of agents with a potential to promote healthy aging.


Subject(s)
Caenorhabditis elegans , Mitophagy , Aged , Animals , Humans , Caenorhabditis elegans/genetics , Diamines , Autophagy , Oxidative Stress
3.
Neuromuscul Disord ; 31(9): 803-813, 2021 09.
Article in English | MEDLINE | ID: mdl-34304968

ABSTRACT

Patients having Duchenne muscular dystrophy (DMD) are currently being treated with corticosteroids, which slow down disease progression at the expense of serious adverse effects. Tamoxifen is a pro-drug some of whose metabolites interact with the nuclear estrogen receptor, leading to anti-fibrotic and muscle-protective effects as has been demonstrated in a murine model of DMD. Here we report the results from a monocentric single arm prospective study in 13 ambulant boys aged 6-14 years with genetically confirmed DMD, aimed to assess the safety of tamoxifen and its impact on disease progression. Boys were treated for up to 3 years with 20 mg/day of oral tamoxifen, in addition to their ongoing corticosteroid treatment. For 8 of these patients, outcome was compared to an age- and performance-matched 12-month natural history dataset. The primary end point was the 6-minute walk test. Secondary end points were the NorthStar assessment, timed function tests, pulmonary function, the biomarker creatine phosphokinase and adverse effects. No adverse effects were noticed other than mild gynecomastia in 4 boys. Tamoxifen-treated patients retained motor and respiratory function, compared with a significant deterioration of age-matched historical control patients receiving corticosteroids only. These encouraging findings warrant a larger clinical trial to substantiate the use of tamoxifen in Duchenne muscular dystrophy.


Subject(s)
Muscular Dystrophy, Duchenne/drug therapy , Selective Estrogen Receptor Modulators/therapeutic use , Tamoxifen/therapeutic use , Adolescent , Adrenal Cortex Hormones/therapeutic use , Child , Disease Progression , Humans , Israel , Male , Motor Activity/drug effects , Prospective Studies , Treatment Outcome , Walk Test
4.
ACS Nano ; 12(6): 5284-5296, 2018 06 26.
Article in English | MEDLINE | ID: mdl-29856606

ABSTRACT

The increasing prevalence of antibacterial resistance globally underscores the urgent need to the update of antibiotics. Here, we describe a strategy for inducing the self-assembly of a host-defense antimicrobial peptide (AMP) into nanoparticle antibiotics (termed nanobiotics) with significantly improved pharmacological properties. Our strategy involves the myristoylation of human α-defensin 5 (HD5) as a therapeutic target and subsequent self-assembly in aqueous media in the absence of exogenous excipients. Compared with its parent HD5, the C-terminally myristoylated HD5 (HD5-myr)-assembled nanobiotic exhibited significantly enhanced broad-spectrum bactericidal activity in vitro. Mechanistically, it selectively killed Escherichia coli ( E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) through disruption of the cell wall and/or membrane structure. The in vivo results further demonstrated that the HD5-myr nanobiotic protected against skin infection by MRSA and rescued mice from E. coli-induced sepsis by lowering the systemic bacterial burden and alleviating organ damage. The self-assembled HD5-myr nanobiotic also showed negligible hemolytic activity and substantially low toxicity in animals. Our findings validate this design rationale as a simple yet versatile strategy for generating AMP-derived nanobiotics with excellent in vivo tolerability. This advancement will likely have a broad impact on antibiotic discovery and development efforts aimed at combating antibacterial resistance.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antimicrobial Cationic Peptides/pharmacology , Escherichia coli Infections/drug therapy , Escherichia coli/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Sepsis/drug therapy , alpha-Defensins/metabolism , Animals , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antimicrobial Cationic Peptides/chemical synthesis , Antimicrobial Cationic Peptides/chemistry , Disease Models, Animal , Escherichia coli/metabolism , Escherichia coli Infections/metabolism , Humans , Methicillin-Resistant Staphylococcus aureus/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Microbial Sensitivity Tests , Nanoparticles/chemistry , Sepsis/metabolism , alpha-Defensins/chemical synthesis , alpha-Defensins/chemistry
5.
Dev Cell ; 45(6): 726-737.e3, 2018 06 18.
Article in English | MEDLINE | ID: mdl-29920277

ABSTRACT

Developmental processes in different mammals are thought to share fundamental cellular mechanisms. We report a dramatic increase in cell size during postnatal pancreas development in rodents, accounting for much of the increase in organ size after birth. Hypertrophy of pancreatic acinar cells involves both higher ploidy and increased biosynthesis per genome copy; is maximal adjacent to islets, suggesting endocrine to exocrine communication; and is partly driven by weaning-related processes. In contrast to the situation in rodents, pancreas cell size in humans remains stable postnatally, indicating organ growth by pure hyperplasia. Pancreatic acinar cell volume varies 9-fold among 24 mammalian species analyzed, and shows a striking inverse correlation with organismal lifespan. We hypothesize that cellular hypertrophy is a strategy for rapid postnatal tissue growth, entailing life-long detrimental effects.


Subject(s)
Organ Size/physiology , Pancreas/growth & development , Pancreas/metabolism , Acinar Cells/physiology , Animals , Cell Enlargement , Cell Size , Humans , Hypertrophy , Insulin-Secreting Cells/physiology , Mice , Pancreas, Exocrine/physiology
6.
Oxid Med Cell Longev ; 2017: 5205471, 2017.
Article in English | MEDLINE | ID: mdl-28757910

ABSTRACT

Curcumin was found to be beneficial in treating several skin pathologies and diseases, providing antioxidant protection due to its reducing properties and its electrophilic properties (the ability to activate the Nrf2 pathway and induce phase II cytoprotective enzymes). Nevertheless, clinical applications of curcumin are being hampered by its insufficient solubility, chemical instability, and poor absorption, leading to low efficacy in preventing skin pathologies. These limitations can be overcome by using a nanotechnology-based delivery system. Here, we elucidated the possibility of using curcumin encapsulated in a microemulsion preserving its unique chemical structure. We also examined whether curcumin microemulsion would reduce UVB-induced toxicity in skin. A significant curcumin concentration was found in the human skin dermis following topical application of a curcumin microemulsion. Moreover, curcumin microemulsion enhanced the reduction of UV-induced cytotoxicity in epidermal cells, paving the way for other incorporated electrophiles in encapsulated form protecting skin against stress-related diseases.


Subject(s)
Curcumin , Drug Delivery Systems/methods , Kelch-Like ECH-Associated Protein 1/metabolism , Keratinocytes/metabolism , NF-E2-Related Factor 2/metabolism , Skin Aging , Ultraviolet Rays/adverse effects , Cell Line, Transformed , Curcumin/chemistry , Curcumin/pharmacology , Emulsions , Humans , Keratinocytes/pathology , Skin Aging/drug effects , Skin Aging/radiation effects
7.
Am J Respir Crit Care Med ; 196(12): 1559-1570, 2017 12 15.
Article in English | MEDLINE | ID: mdl-28850247

ABSTRACT

RATIONALE: Efficient elimination of pathogenic bacteria is a critical determinant in the outcome of sepsis. Sphingosine-1-phosphate receptor 3 (S1PR3) mediates multiple aspects of the inflammatory response during sepsis, but whether S1PR3 signaling is necessary for eliminating the invading pathogens remains unknown. OBJECTIVES: To investigate the role of S1PR3 in antibacterial immunity during sepsis. METHODS: Loss- and gain-of-function experiments were performed using cell and murine models. S1PR3 levels were determined in patients with sepsis and healthy volunteers. MEASUREMENTS AND MAIN RESULTS: S1PR3 protein levels were up-regulated in macrophages upon bacterial stimulation. S1pr3-/- mice showed increased mortality and increased bacterial burden in multiple models of sepsis. The transfer of wild-type bone marrow-derived macrophages rescued S1pr3-/- mice from lethal sepsis. S1PR3-overexpressing macrophages further ameliorated the mortality rate of sepsis. Loss of S1PR3 led to markedly decreased bacterial killing in macrophages. Enhancing endogenous S1PR3 activity using a peptide agonist potentiated the macrophage bactericidal function and improved survival rates in multiple models of sepsis. Mechanically, the reactive oxygen species levels were decreased and phagosome maturation was delayed in S1pr3-/- macrophages due to impaired recruitment of vacuolar protein-sorting 34 to the phagosomes. In addition, S1RP3 expression levels were elevated in monocytes from patients with sepsis. Higher levels of monocytic S1PR3 were associated with efficient intracellular bactericidal activity, better immune status, and preferable outcomes. CONCLUSIONS: S1PR3 signaling drives bacterial killing and is essential for survival in bacterial sepsis. Interventions targeting S1PR3 signaling could have translational implications for manipulating the innate immune response to combat pathogens.


Subject(s)
Cell Death/immunology , Receptors, Lysosphingolipid/genetics , Receptors, Lysosphingolipid/immunology , Sepsis/immunology , Signal Transduction/immunology , Animals , Cell Death/genetics , Disease Models, Animal , Disease-Free Survival , Humans , Mice , Signal Transduction/genetics , Sphingosine-1-Phosphate Receptors , Up-Regulation/genetics , Up-Regulation/immunology
8.
Free Radic Biol Med ; 104: 238-248, 2017 03.
Article in English | MEDLINE | ID: mdl-28088623

ABSTRACT

For a long time iodine has been used as an active dermal agent in the treatment of inflammatory, immune-mediated and infectious diseases. Moreover, topical iodine application has been reported to provide protection against sulfur-mustard-induced skin lesions, heat-induced and acid-induced skin burns in both haired guinea-pigs and mouse ear swelling models. However, the exact mechanism of action underlying these benefits of iodine has not yet been elucidated. In the current study, a novel mechanism of action by which iodine provides skin protection and relief, based on its electrophilic nature, is suggested. This study demonstrates that both iodine and iodide are capable of activating the Nrf2 pathway in human skin. As a result, skin protection against UVB-induced damage was acquired and the secretion of pro-inflammatory cytokines (IL-6, IL-8) from LPS-challenged skin was reduced. Iodide role in the enhanced activation of this pathway is demonstrated. The mode of action by which iodine and iodide activate the Nrf2 pathway is discussed.


Subject(s)
Burns/drug therapy , Inflammation/drug therapy , Iodine/administration & dosage , NF-E2-Related Factor 2/genetics , Skin/drug effects , Administration, Topical , Animals , Burns/genetics , Burns/pathology , Disease Models, Animal , Humans , Inflammation/chemically induced , Inflammation/genetics , Interleukin-6/genetics , Interleukin-8/genetics , Iodides/administration & dosage , Mice , Mustard Gas/toxicity , Skin/pathology , Skin/radiation effects , Ultraviolet Rays
9.
Proc Natl Acad Sci U S A ; 113(13): E1826-34, 2016 Mar 29.
Article in English | MEDLINE | ID: mdl-26976580

ABSTRACT

Minimally invasive detection of cell death could prove an invaluable resource in many physiologic and pathologic situations. Cell-free circulating DNA (cfDNA) released from dying cells is emerging as a diagnostic tool for monitoring cancer dynamics and graft failure. However, existing methods rely on differences in DNA sequences in source tissues, so that cell death cannot be identified in tissues with a normal genome. We developed a method of detecting tissue-specific cell death in humans based on tissue-specific methylation patterns in cfDNA. We interrogated tissue-specific methylome databases to identify cell type-specific DNA methylation signatures and developed a method to detect these signatures in mixed DNA samples. We isolated cfDNA from plasma or serum of donors, treated the cfDNA with bisulfite, PCR-amplified the cfDNA, and sequenced it to quantify cfDNA carrying the methylation markers of the cell type of interest. Pancreatic ß-cell DNA was identified in the circulation of patients with recently diagnosed type-1 diabetes and islet-graft recipients; oligodendrocyte DNA was identified in patients with relapsing multiple sclerosis; neuronal/glial DNA was identified in patients after traumatic brain injury or cardiac arrest; and exocrine pancreas DNA was identified in patients with pancreatic cancer or pancreatitis. This proof-of-concept study demonstrates that the tissue origins of cfDNA and thus the rate of death of specific cell types can be determined in humans. The approach can be adapted to identify cfDNA derived from any cell type in the body, offering a minimally invasive window for diagnosing and monitoring a broad spectrum of human pathologies as well as providing a better understanding of normal tissue dynamics.


Subject(s)
DNA Methylation , DNA/blood , Insulin-Secreting Cells/pathology , Oligodendroglia/pathology , Adolescent , Adult , Aged , Brain Ischemia/genetics , Brain Ischemia/pathology , Case-Control Studies , Cell Death , Child , Child, Preschool , DNA/metabolism , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/pathology , Female , Genetic Markers , Humans , Male , Middle Aged , Multiple Sclerosis, Relapsing-Remitting/genetics , Multiple Sclerosis, Relapsing-Remitting/pathology , Organ Specificity , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Pancreatitis, Chronic/genetics , Pancreatitis, Chronic/pathology , Promoter Regions, Genetic , Sensitivity and Specificity , Young Adult
10.
Free Radic Biol Med ; 77: 258-69, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25236737

ABSTRACT

Nitroxides are stable cyclic radicals of diverse size, charge, and lipophilicity. They are cell-permeative, which effectively protects cells, tissues, isolated organs, and laboratory animals from radical-induced damage. The mechanisms of activity through which nitroxides operate are diverse, including superoxide dismutase-mimetic activity, oxidation of semiquinone radicals, oxidation of reduced metal ions, procatalase-mimetic activity, interruption of radical chain reactions, and indirect modulation of NO levels. Nitroxides possess both a nucleophilic (reducing properties) and an electrophilic (oxidizing properties) nature and, therefore, they may affect different cellular pathways. In the current study, a novel mechanism of action by which nitroxides provide skin protection based on their electrophilic nature is suggested. This study shows that nitroxides may act as electrophiles, directly or indirectly, capable of activating the Keap1-Nrf2-ARE pathway in human keratinocytes (HaCaT) and in human skin (human organ culture model). The high potency of oxoammonium cations versus hydroxylamines in activating the system is demonstrated. The mechanism of action by which nitroxides activate the Keap1-Nrf2-ARE pathway is discussed. Understanding the mechanism of activity may expand the usage of nitroxides as a skin protection strategy against oxidative stress-related conditions.


Subject(s)
Antioxidant Response Elements , Intracellular Signaling Peptides and Proteins/metabolism , Keratinocytes/metabolism , NF-E2-Related Factor 2/metabolism , Nitrogen Oxides/pharmacology , Adult , Cell Line , Female , Humans , Kelch-Like ECH-Associated Protein 1 , Middle Aged , Signal Transduction , Tissue Culture Techniques , Transcriptional Activation , Young Adult
11.
J Microencapsul ; 30(6): 580-8, 2013.
Article in English | MEDLINE | ID: mdl-23489012

ABSTRACT

Here we present the newly developed "solvent exchange" method that overcomes the challenge of encapsulating hydrophobic compounds within nanoparticle of water soluble polymers. Our studies involved the model polymer polyvinylpyrrolidone (PVP) and the hydrophobic dye Nile red. We found that the minimum molecular weight of the polymer required for nanoparticle formation was 49 KDa. Dynamic Light Scattering (DLS) and Cryo-Transmission Electron Microscopy (cryo-TEM) studies revealed spherical nanoparticles with an average diameter ranging from 20 to 33 nm. Encapsulation efficiency was evaluated using UV spectroscopy and found to be around 94%. The nanocarriers were found to be highly stable; less than 2% of Nile red release from nanoparticles after the addition of NaCl. Nanoparticles containing Nile red were able to penetrate into glioma cells. The solvent exchange method was proved to be applicable for other model hydrophobic drug molecules including ketoprofen, ibuprofen and indomethacin, as well as other solvents.


Subject(s)
Drug Carriers/chemistry , Fluorescent Dyes/administration & dosage , Nanoparticles/chemistry , Oxazines/administration & dosage , Povidone/chemistry , Cations/chemistry , Drug Delivery Systems , Hydrophobic and Hydrophilic Interactions
12.
PLoS One ; 6(7): e21650, 2011.
Article in English | MEDLINE | ID: mdl-21747944

ABSTRACT

Prostate cancer is the most common non-dermatologic malignancy in men in the Western world. Recently, a frequent chromosomal aberration fusing androgen regulated TMPRSS2 promoter and the ERG gene (TMPRSS2/ERG) was discovered in prostate cancer. Several studies demonstrated cooperation between TMPRSS2/ERG and other defective pathways in cancer progression. However, the unveiling of more specific pathways in which TMPRSS2/ERG takes part, requires further investigation. Using immortalized prostate epithelial cells we were able to show that TMPRSS2/ERG over-expressing cells undergo an Epithelial to Mesenchymal Transition (EMT), manifested by acquisition of mesenchymal morphology and markers as well as migration and invasion capabilities. These findings were corroborated in vivo, where the control cells gave rise to discrete nodules while the TMPRSS2/ERG-expressing cells formed malignant tumors, which expressed EMT markers. To further investigate the general transcription scheme induced by TMPRSS2/ERG, cells were subjected to a microarray analysis that revealed a distinct EMT expression program, including up-regulation of the EMT facilitators, ZEB1 and ZEB2, and down-regulation of the epithelial marker CDH1(E-Cadherin). A chromatin immunoprecipitation assay revealed direct binding of TMPRSS2/ERG to the promoter of ZEB1 but not ZEB2. However, TMPRSS2/ERG was able to bind the promoters of the ZEB2 modulators, IL1R2 and SPINT1. This set of experiments further illuminates the mechanism by which the TMPRSS2/ERG fusion affects prostate cancer progression and might assist in targeting TMPRSS2/ERG and its downstream targets in future drug design efforts.


Subject(s)
Epithelial-Mesenchymal Transition , Homeodomain Proteins/metabolism , Prostatic Neoplasms/pathology , Repressor Proteins/metabolism , Serine Endopeptidases/metabolism , Trans-Activators/metabolism , Transcription Factors/metabolism , Animals , Cell Line , Disease Models, Animal , Epithelial-Mesenchymal Transition/genetics , Gene Fusion , Genetic Vectors/genetics , Humans , Male , Mice , Phenotype , Prostatic Neoplasms/genetics , Serine Endopeptidases/genetics , Signal Transduction/genetics , Trans-Activators/genetics , Zinc Finger E-box Binding Homeobox 2 , Zinc Finger E-box-Binding Homeobox 1
13.
Cancer Res ; 66(14): 7216-24, 2006 Jul 15.
Article in English | MEDLINE | ID: mdl-16849569

ABSTRACT

Cancers have been described as wounds that do not heal, suggesting that the two share common features. By comparing microarray data from a model of renal regeneration and repair (RRR) with reported gene expression in renal cell carcinoma (RCC), we asked whether those two processes do, in fact, share molecular features and regulatory mechanisms. The majority (77%) of the genes expressed in RRR and RCC were concordantly regulated, whereas only 23% were discordant (i.e., changed in opposite directions). The orchestrated processes of regeneration, involving cell proliferation and immune response, were reflected in the concordant genes. The discordant gene signature revealed processes (e.g., morphogenesis and glycolysis) and pathways (e.g., hypoxia-inducible factor and insulin-like growth factor-I) that reflect the intrinsic pathologic nature of RCC. This is the first study that compares gene expression patterns in RCC and RRR. It does so, in particular, with relation to the hypothesis that RCC resembles the wound healing processes seen in RRR. However, careful attention to the genes that are regulated in the discordant direction provides new insights into the critical differences between renal carcinogenesis and wound healing. The observations reported here provide a conceptual framework for further efforts to understand the biology and to develop more effective diagnostic biomarkers and therapeutic strategies for renal tumors and renal ischemia.


Subject(s)
Carcinoma, Renal Cell/pathology , Kidney Neoplasms/pathology , Kidney/physiology , Regeneration/physiology , Animals , Carcinoma, Renal Cell/genetics , Female , Gene Expression , Kidney Neoplasms/genetics , Mice , Mice, Inbred C57BL , Oligonucleotide Array Sequence Analysis , Regeneration/genetics
14.
J Endovasc Ther ; 13(1): 94-103, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16445329

ABSTRACT

PURPOSE: To investigate if a platelet inhibitor (aurintricarboxylic acid [ATA]) and a heparin-mimicking antagonist (RG-13577) of basic fibroblast growth factor 2 (bFGF2) could be combined as a stable compound and attached to conventional bare metal stents to hinder thrombus formation and inflammatory reactions of stenting. METHODS: Fifteen domestic pigs were stented with RG-13577/ATA-coated (n=6), ATA-coated (n=12), and bare metal stents (n=12) in the left anterior descending (LAD) and left circumflex (LCX) coronary arteries. All surviving pigs were evaluated with contrast angiography and intravascular ultrasonography (IVUS) after 4 weeks. Histological analysis of the stented arteries was performed after hematoxylin-eosin staining. Tissue factor (TF) staining and scanning electron microscopy (SEM) were performed in animals with acute stent thrombosis. RESULTS: Five of the 6 animals receiving an RG-13577/ATA-coated stent experienced acute stent thrombosis, while no adverse events occurred in the animals of the other 2 groups. Follow-up angiography did not show significant in-stent stenosis in either bare or ATA-coated stents. However, histomorphometry revealed larger neointimal area (3.54+/-0.69 mm2 versus 1.82+/-0.27 mm2, p<0.05) and outward plaque area (1.56+/-0.34 mm2 versus 0.61+/-0.12 mm2, p<0.05) in ATA-coated stents. Three-dimensional IVUS analysis showed analogous results, with significantly larger neointimal volume and outward plaque volume in ATA-coated stents. There was a slight increase in TF staining around the stent struts, while SEM showed increased platelet adhesion and activity in RG-13577/ATA-coated stents versus the ATA-coated and bare metal stents. CONCLUSION: RG-13577/ATA-coated stents lead to acute stent thrombosis. The ATA coating alone did not lead to acute events, but resulted in higher neointimal hyperplasia and expansive remodeling. These results underline the importance of preclinical studies before using new coated stents in human arteries.


Subject(s)
Aurintricarboxylic Acid/pharmacology , Aurintricarboxylic Acid/toxicity , Coronary Vessels/drug effects , Fibroblast Growth Factor 2/antagonists & inhibitors , Phenoxyacetates/pharmacology , Phenoxyacetates/toxicity , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation Inhibitors/toxicity , Polymers/pharmacology , Polymers/toxicity , Stents , Thrombosis/etiology , Animals , Aurintricarboxylic Acid/administration & dosage , Coronary Angiography , Coronary Restenosis/prevention & control , Coronary Vessels/pathology , Drug Combinations , Drug Evaluation, Preclinical , Hyperplasia , Microscopy, Electron, Scanning , Phenoxyacetates/administration & dosage , Platelet Aggregation Inhibitors/administration & dosage , Polymers/administration & dosage , Stents/adverse effects , Swine , Thrombosis/diagnostic imaging , Thrombosis/pathology , Treatment Failure , Tunica Intima/drug effects , Tunica Intima/pathology
15.
Cancer Res ; 64(3): 1058-66, 2004 Feb 01.
Article in English | MEDLINE | ID: mdl-14871838

ABSTRACT

The Src-related protein kinase Lyn plays an important role in B-cell activation. However, several lines of evidence suggest that it is also involved in the control of cellular proliferation and the inhibition of apoptosis. We have discovered that Lyn is expressed in normal prostate epithelia, in 95% of primary human prostate cancer (PC) specimens examined, and in all of the PC cell lines that we assayed. Moreover, Lyn knockout mice display abnormal prostate gland morphogenesis, which suggests that Lyn plays an important role in prostate epithelium development and implies that Lyn is a candidate target for specific therapy for PC. Using a drug-design strategy to construct sequence-based peptide inhibitors, a Lyn-specific inhibitor, KRX-123, targeting a unique interaction site within Lyn, was synthesized. KRX-123 was found to inhibit cellular proliferation in three hormone-refractory PC cell lines, DU145, PC3, and TSU-Pr1 with IC(50) values of 2-4 micro M. In vivo, tumor volume of DU145 explants in nude mice was significantly reduced after once-a-week injections of KRX-123, at a dose of 10 mg/kg, for a period of 5 weeks. Histological analyses of the treated tumors indicated extensive apoptosis. Thus, we suggest that Lyn inhibition may serve as a prime target for the treatment of hormone-refractory PC.


Subject(s)
Enzyme Inhibitors/pharmacology , Peptides/pharmacology , Prostatic Neoplasms/genetics , src-Family Kinases/antagonists & inhibitors , src-Family Kinases/genetics , Animals , Cell Line, Tumor , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Nude , Oligopeptides/chemistry , Oligopeptides/pharmacology , Phosphorylation/drug effects , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/enzymology , Xenograft Model Antitumor Assays
16.
J Biol Chem ; 279(2): 1242-55, 2004 Jan 09.
Article in English | MEDLINE | ID: mdl-14570903

ABSTRACT

A platform for specifically modulating kinase-dependent signaling using peptides derived from the catalytic domain of the kinase is presented. This technology, termed KinAce, utilizes the canonical structure of protein kinases. The targeted regions (subdomain V and subdomains IX and X) are analyzed and their sequence, three-dimensional structure, and involvement in protein-protein interaction are highlighted. Short myristoylated peptides were derived from the target regions of the tyrosine kinases c-Kit and Lyn and the serine/threonine kinases 3-phosphoinositide-dependent kinase-1 (PDK1) and Akt/protein kinase B (PKB). For each kinase an active designer peptide is shown to selectively inhibit the signaling of the kinase from which it is derived, and to inhibit cancer cell proliferation in the micromolar range. This technology emerges as an applicable tool for deriving sequence-based selective inhibitors for a broad range of protein kinases as hits that may be further developed into drugs. Moreover, it enables identification of novel kinase targets for selected therapeutic indications as demonstrated in the KinScreen application.


Subject(s)
Drug Design , 3-Phosphoinositide-Dependent Protein Kinases , Amino Acid Sequence , Animals , Aorta/metabolism , Catalytic Domain , Cell Cycle Proteins/metabolism , Cell Division , Cell Line, Tumor , Cell-Free System , Cloning, Molecular , Cyclin-Dependent Kinase Inhibitor p27 , Cytosol/metabolism , DNA Mutational Analysis , Dose-Response Relationship, Drug , Glutathione Transferase/metabolism , Humans , Immunoblotting , Male , Mice , Mice, Inbred BALB C , Models, Molecular , Molecular Sequence Data , Myristic Acids/metabolism , Peptides/chemistry , Phosphorylation , Protein Binding , Protein Serine-Threonine Kinases/metabolism , Protein Structure, Tertiary , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Proto-Oncogene Proteins c-kit/metabolism , Substrate Specificity , Tumor Suppressor Proteins/metabolism , src-Family Kinases/metabolism
17.
Blood ; 102(6): 2099-107, 2003 Sep 15.
Article in English | MEDLINE | ID: mdl-12763936

ABSTRACT

The G-protein-coupled receptors of the endothelial differentiation gene (EDG) family mediate pro-angiogenic activities, such as endothelial cell proliferation, chemotaxis, and vessel morphogenesis. We synthesized and tested the effects of a 9-amino acid peptide (KRX-725), derived from the second intracellular loop of S1P3 (EDG3). KRX-725 mimics the effects of sphingosine 1-phosphate (S1P), the natural ligand of S1P3, by triggering a Gi-dependent MEK-ERK (mitogen-activated protein kinase kinase and extracellular signal-regulated kinase) signal transduction pathway. Using aortic rings as an ex vivo model of angiogenesis, vascular sprouting was assessed in the presence of KRX-725 or S1P. KRX-725 induced extensive and dense vascular sprouts, which contain an elaborated organization of endothelial and smooth muscle layers, including lumen formation. When KRX-725 or S1P was combined with proangiogenic factors, such as basic fibroblast growth factor (bFGF), stem cell factor, or vascular endothelial growth factor, the effect was synergistic, leading to further enhancement of vascular sprouting. KRX-725 also initiated neovascularization in a mouse corneal pocket assay in vivo and showed synergism with bFGF. The specificity of KRX-725 was demonstrated via peptide-induced receptor internalization of S1P3 but not S1P1. The ability of a short peptide to stimulate extensive angiogenesis and to synergize with pro-angiogenic factors suggests that KRX-725 may serve as a useful agent in treating pathologic conditions such as peripheral vascular disease, cardiac ischemia, or tissue grafts.


Subject(s)
I-kappa B Proteins/metabolism , MAP Kinase Signaling System/physiology , Neovascularization, Physiologic/physiology , Peptide Fragments/pharmacology , Animals , Aorta/cytology , Cells, Cultured , Dose-Response Relationship, Drug , Drug Synergism , Endothelial Growth Factors/pharmacology , Endothelium, Vascular/cytology , Fibroblast Growth Factor 2/pharmacology , GTP-Binding Protein alpha Subunits, Gi-Go/metabolism , Humans , I-kappa B Proteins/chemistry , I-kappa B Proteins/genetics , Intercellular Signaling Peptides and Proteins/pharmacology , Lymphokines/pharmacology , MAP Kinase Signaling System/drug effects , Mice , Mice, Inbred C57BL , Mitogen-Activated Protein Kinases/metabolism , Muscle, Smooth, Vascular/cytology , NF-KappaB Inhibitor alpha , Neovascularization, Physiologic/drug effects , Peptide Fragments/chemical synthesis , Protein Structure, Tertiary , Receptors, Lysophospholipid , Stem Cell Factor/pharmacology , Transfection , Umbilical Veins/cytology , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
18.
J Neurol Sci ; 206(1): 49-57, 2003 Jan 15.
Article in English | MEDLINE | ID: mdl-12480085

ABSTRACT

The immunomodulating capacity of heparin led us to test the effect of the synthetic heparin-mimicking and low anticoagulant compound RG-13577 on the course of experimental autoimmune encephalomyelitis (EAE) and central nervous system (CNS) inflammation. EAE was induced in SJL mice by inoculation with whole mouse spinal cord homogenate. RG-13577, delivered intraperitoneally, inhibited the clinical signs of acute EAE and markedly ameliorated inflammation in the spinal cord, primarily by inhibiting heparanase activity in lymphocytes and astrocytes and thus impairing lymphocyte traffic. RG-13577 treatment was effective when started on day of disease induction or day 7 after induction. The low molecular weight heparin, enoxaparin, tested under the same conditions, exerted only a minor insignificant inhibitory effect. RG-13577 also inhibited the tyrosine phosphorylation of several proteins, particularly Erk1 and Erk2 of the MAP kinase signaling pathways associated with inflammation and cell proliferation. RG-13577 blocked the activity of sPLA(2) and inhibited CNS PGE(2) production both in vivo and in vitro.


Subject(s)
Anticoagulants/pharmacology , Central Nervous System/physiopathology , Encephalomyelitis, Autoimmune, Experimental/physiopathology , Heparin/pharmacology , Heparin/physiology , Inflammation/prevention & control , Animals , Brain/metabolism , Central Nervous System/drug effects , DNA Primers , Dinoprostone/metabolism , Female , Glucuronidase/genetics , Heparin/chemistry , Mice , Mice, Inbred Strains , Phenoxyacetates/pharmacology , Phosphorylation , Phosphotyrosine/metabolism , Polymers/pharmacology , Spinal Cord/drug effects , Spinal Cord/physiopathology
19.
Coron Artery Dis ; 13(5): 291-4, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12394654

ABSTRACT

BACKGROUND: We evaluated the usefulness of intravascular ultrasound (IVUS) in the non-uniform distribution of in-stent neointimal hyperplasia, comparing macroscopic measurements with IVUS-guided histomorphometry. METHODS: Coronary stenting was performed in 45 left coronaries of 39 pigs, using 18 Tenax (Biotronik Gmbh and Co., Berlin, Germany), 11 bare Genius (Eurocor, Bonn, Germany), 10 polymer-coated Genius (Eurocor) and six Biodivysio Matrix LO (Biodivysio Ltd, Farnham, Surrey, UK) stents. After 4 weeks, coronary angiography and IVUS with automatic pullback were performed. IVUS images were analysed using three-dimensional analysis (EchoPlaque 2; INDEC Systems Inc., Mountain View, California, USA). The stented segments were formalin fixed, embedded in Technovit 9100 and cut to 4-8 microm thick slides. The most diseased in-stent segment was 4.49 +/- 4.54 mm away from the distal stent edge assessed by IVUS. Sections of these segments were stained for histomorphometry. RESULTS: A significant correlation was found between IVUS-guided histomorphometry and three-dimensional IVUS measurements of maximal intimal thickness (r = 0.6985, P < 0.005) and area (r = 0.7736, P < 0.001). Macroscopic measurements resulted in comparable maximal intimal thickness (0.83 +/- 0.43 mm compared with 0.81 +/- 0.46 mm) and area (4.44 +/- 1.73 mm2 compared with 3.45 +/- 1.55 mm2) by IVUS and histomorphometry, respectively. Although stent length, diameter, nominal inflation pressure and time and injury score did not differ between the stents, bare Genius stents resulted in significant smaller neointimal volume compared to Tenax, polymer-coated Genius and Biodivysio stents: 24.46 +/- 4.98 mm3 compared with 59.18 +/- 26.41, 60.46 +/- 10.03 and 61.41 +/- 16.27 mm3, respectively (P < 0.05). CONCLUSION: The significant correlation between IVUS-guided histomorphometry and IVUS measurements confirms the usefulness of IVUS in evaluation of experimental in-stent restenosis. Implantation of bare Genius stents resulted in significant lower neointimal hyperplasia compared to Tenax, polymer-coated Genius or phosphorylcholine-coated Biodivysio stents.


Subject(s)
Coronary Restenosis/diagnostic imaging , Coronary Restenosis/pathology , Coronary Vessels/diagnostic imaging , Coronary Vessels/pathology , Stents , Ultrasonography, Interventional , Animals , Female , Hyperplasia , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Male , Stents/adverse effects , Swine
20.
J Cell Physiol ; 192(3): 276-85, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12124773

ABSTRACT

A series of nine synthetic polyaromatic compounds were synthesized by polymerization of aromatic ring monomers with formaldehyde, which yield substantially ordered backbones with different functional anionic groups (hydroxyl and carboxyl) on the phenol ring. These compounds were tested for their heparin-mimicking activity: (1) inhibition of heparanase activity; (2) inhibition of SMC proliferation; and (3) release of bFGF from the ECM. We demonstrate that compounds that have two hydroxyl groups para and ortho to the carboxylic group and a carboxylic group at a distance of two carbons from the phenol ring inhibit heparanase activity and SMC proliferation, as well as induced an almost complete release of bFGF from ECM. Addition of a methyl group next to the carboxylic group led to a preferential inhibition of heparanase activity. Similar results were obtained with a compound that contains one hydroxyl group para to the carboxylic group and an ether group near the carboxylic group on the phenol ring. Preferential inhibition of SMC proliferation was best achieved when the position of the hydroxyl group is para and ortho to the carboxylic group and the carboxylic group is at a distance of one carbon from the phenol ring. On the other hand, for maximal release of bFGF from ECM, the position of the carboxylic group should be three carbons away from the phenol ring. These new heparin-mimicking compounds may have a potential use in inhibition of tumor metastasis, arteriosclerosis, and inflammation.


Subject(s)
Fibroblast Growth Factor 2/metabolism , Heparin/chemistry , Heparin/pharmacology , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/physiology , Animals , Cattle , Cell Division/drug effects , Cells, Cultured , Extracellular Matrix/drug effects , Fibroblast Growth Factor 2/pharmacology , Glucuronidase/metabolism , Heparitin Sulfate/metabolism , Hydrocarbons, Aromatic/chemistry , Hydrocarbons, Aromatic/pharmacology , Molecular Mimicry , Muscle, Smooth, Vascular/cytology , Structure-Activity Relationship , Thrombin/pharmacology
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