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Fiorito S, Collevecchio C, Epifano F, Genovese S. Targeting prolidase. A survey of the literature data to depict a structure-activity relationship frame and to address future studies for drug development. Bioorg Med Chem 2024; 110:117833. [PMID: 38996544 DOI: 10.1016/j.bmc.2024.117833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 07/04/2024] [Accepted: 07/08/2024] [Indexed: 07/14/2024]
Abstract
Prolidase (EC.3.4.13.9) is a Mn+2-dependent dipeptidase that is well known to play a crucial role in several physiological and pathological processes affecting humans. More in particular, this enzyme is involved in the cleavage of proline- and hydroxyproline-containing dipeptides (imidodipeptides), providing a fine regulation of the homeostasis of these two amino acids. Hyperactivity or deficiency of prolidase have been clearly associated to the development and progress of several acute and chronic syndromes (e.g. chronic liver fibrosis, viral and acute hepatitis, cancer, neurological disorders, inflammation, skin diseases, intellectual disability, respiratory infection). Thus, targeting prolidase and modulating its activity is an intriguing field of research with a great therapeutic potential for the next future and for the design of specific and selective drugs. Prolidase can be exploited in two essential ways: as an activator of proline containing prodrugs and by direct interaction. In this latter case, few specific ligands for the title enzyme have been described, but with no reports about their structure-activity relationship. The aim of this comprehensive review is to gather all available information on prolidase targeting so far reported in the literature, to rationalize the observed data and effect into a preliminary structure-relationship picture, to comment about the effectiveness of each reported ligands, and to address future research activities providing new potential and putative natural, semisynthetic, and purely synthetic molecules able to trigger prolidase as the main biological target.
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Affiliation(s)
- Serena Fiorito
- Dipartimento di Farmacia, Università "Gabriele d'Annunzio" Chieti - Pescara, Via dei Vestini 31, 66100 Chieti Scalo (CH), Italy
| | - Chiara Collevecchio
- Dipartimento di Farmacia, Università "Gabriele d'Annunzio" Chieti - Pescara, Via dei Vestini 31, 66100 Chieti Scalo (CH), Italy
| | - Francesco Epifano
- Dipartimento di Farmacia, Università "Gabriele d'Annunzio" Chieti - Pescara, Via dei Vestini 31, 66100 Chieti Scalo (CH), Italy.
| | - Salvatore Genovese
- Dipartimento di Farmacia, Università "Gabriele d'Annunzio" Chieti - Pescara, Via dei Vestini 31, 66100 Chieti Scalo (CH), Italy.
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Eni-Aganga I, Lanaghan ZM, Ismail F, Korolkova O, Goodwin JS, Balasubramaniam M, Dash C, Pandhare J. KLF6 activates Sp1-mediated prolidase transcription during TGF-β 1 signaling. J Biol Chem 2024; 300:105605. [PMID: 38159857 PMCID: PMC10847167 DOI: 10.1016/j.jbc.2023.105605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/09/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024] Open
Abstract
Prolidase (PEPD) is the only hydrolase that cleaves the dipeptides containing C-terminal proline or hydroxyproline-the rate-limiting step in collagen biosynthesis. However, the molecular regulation of prolidase expression remains largely unknown. In this study, we have identified overlapping binding sites for the transcription factors Krüppel-like factor 6 (KLF6) and Specificity protein 1 (Sp1) in the PEPD promoter and demonstrate that KLF6/Sp1 transcriptionally regulate prolidase expression. By cloning the PEPD promoter into a luciferase reporter and through site-directed deletion, we pinpointed the minimal sequences required for KLF6 and Sp1-mediated PEPD promoter-driven transcription. Interestingly, Sp1 inhibition abrogated KLF6-mediated PEPD promoter activity, suggesting that Sp1 is required for the basal expression of prolidase. We further studied the regulation of PEPD by KLF6 and Sp1 during transforming growth factor β1 (TGF-β1) signaling, since both KLF6 and Sp1 are key players in TGF-β1 mediated collagen biosynthesis. Mouse and human fibroblasts exposed to TGF-β1 resulted in the induction of PEPD transcription and prolidase expression. Inhibition of TGF-β1 signaling abrogated PEPD promoter-driven transcriptional activity of KLF6 and Sp1. Knock-down of KLF6 as well as Sp1 inhibition also reduced prolidase expression. Chromatin immunoprecipitation assay supported direct binding of KLF6 and Sp1 to the PEPD promoter and this binding was enriched by TGF-β1 treatment. Finally, immunofluorescence studies showed that KLF6 co-operates with Sp1 in the nucleus to activate prolidase expression and enhance collagen biosynthesis. Collectively, our results identify functional elements of the PEPD promoter for KLF6 and Sp1-mediated transcriptional activation and describe the molecular mechanism of prolidase expression.
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Affiliation(s)
- Ireti Eni-Aganga
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; School of Graduate Studies, Meharry Medical College, Nashville, Tennessee, USA; Department of Microbiology, Immunology and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Zeljka Miletic Lanaghan
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; Neuroscience Graduate Program, Vanderbilt University, Nashville, Tennessee, USA
| | - Farah Ismail
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA
| | - Olga Korolkova
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; Department of Biochemistry, Cancer Biology, Pharmacology and Neuroscience, Meharry Medical College, Nashville, Tennessee, USA
| | - Jeffery Shawn Goodwin
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; Department of Biochemistry, Cancer Biology, Pharmacology and Neuroscience, Meharry Medical College, Nashville, Tennessee, USA
| | - Muthukumar Balasubramaniam
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; Department of Biochemistry, Cancer Biology, Pharmacology and Neuroscience, Meharry Medical College, Nashville, Tennessee, USA
| | - Chandravanu Dash
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; Department of Microbiology, Immunology and Physiology, Meharry Medical College, Nashville, Tennessee, USA; Department of Biochemistry, Cancer Biology, Pharmacology and Neuroscience, Meharry Medical College, Nashville, Tennessee, USA.
| | - Jui Pandhare
- Center for AIDS Health Disparities Research, Meharry Medical College, Nashville, Tennessee, USA; School of Graduate Studies, Meharry Medical College, Nashville, Tennessee, USA; Department of Microbiology, Immunology and Physiology, Meharry Medical College, Nashville, Tennessee, USA.
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Eni-Aganga I, Lanaghan ZM, Balasubramaniam M, Dash C, Pandhare J. PROLIDASE: A Review from Discovery to its Role in Health and Disease. Front Mol Biosci 2021; 8:723003. [PMID: 34532344 PMCID: PMC8438212 DOI: 10.3389/fmolb.2021.723003] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 08/18/2021] [Indexed: 01/14/2023] Open
Abstract
Prolidase (peptidase D), encoded by the PEPD gene, is a ubiquitously expressed cytosolic metalloproteinase, the only enzyme capable of cleaving imidodipeptides containing C-terminal proline or hydroxyproline. Prolidase catalyzes the rate-limiting step during collagen recycling and is essential in protein metabolism, collagen turnover, and matrix remodeling. Prolidase, therefore plays a crucial role in several physiological processes such as wound healing, inflammation, angiogenesis, cell proliferation, and carcinogenesis. Accordingly, mutations leading to loss of prolidase catalytic activity result in prolidase deficiency a rare autosomal recessive metabolic disorder characterized by defective wound healing. In addition, alterations in prolidase enzyme activity have been documented in numerous pathological conditions, making prolidase a useful biochemical marker to measure disease severity. Furthermore, recent studies underscore the importance of a non-enzymatic role of prolidase in cell regulation and infectious disease. This review aims to provide comprehensive information on prolidase, from its discovery to its role in health and disease, while addressing the current knowledge gaps.
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Affiliation(s)
- Ireti Eni-Aganga
- Center for AIDS Health Disparities Research, Nashville, TN, United States
- School of Graduate Studies and Research, Nashville, TN, United States
- Department of Microbiology, Immunology and Physiology, Nashville, TN, United States
| | - Zeljka Miletic Lanaghan
- Center for AIDS Health Disparities Research, Nashville, TN, United States
- Pharmacology Graduate Program, Vanderbilt University, Nashville, TN, United States
| | - Muthukumar Balasubramaniam
- Center for AIDS Health Disparities Research, Nashville, TN, United States
- Department of Biochemistry, Cancer Biology, Pharmacology and Neuroscience, Meharry Medical College, Nashville, TN, United States
| | - Chandravanu Dash
- Center for AIDS Health Disparities Research, Nashville, TN, United States
- School of Graduate Studies and Research, Nashville, TN, United States
- Department of Biochemistry, Cancer Biology, Pharmacology and Neuroscience, Meharry Medical College, Nashville, TN, United States
| | - Jui Pandhare
- Center for AIDS Health Disparities Research, Nashville, TN, United States
- School of Graduate Studies and Research, Nashville, TN, United States
- Department of Microbiology, Immunology and Physiology, Nashville, TN, United States
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Current Understanding of the Emerging Role of Prolidase in Cellular Metabolism. Int J Mol Sci 2020; 21:ijms21165906. [PMID: 32824561 PMCID: PMC7460564 DOI: 10.3390/ijms21165906] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/11/2020] [Accepted: 08/15/2020] [Indexed: 12/12/2022] Open
Abstract
Prolidase [EC 3.4.13.9], known as PEPD, cleaves di- and tripeptides containing carboxyl-terminal proline or hydroxyproline. For decades, prolidase has been thoroughly investigated, and several mechanisms regulating its activity are known, including the activation of the β1-integrin receptor, insulin-like growth factor 1 receptor (IGF-1) receptor, and transforming growth factor (TGF)-β1 receptor. This process may result in increased availability of proline in the mitochondrial proline cycle, thus making proline serve as a substrate for the resynthesis of collagen, an intracellular signaling molecule. However, as a ligand, PEPD can bind directly to the epidermal growth factor receptor (EGFR, epidermal growth factor receptor 2 (HER2)) and regulate cellular metabolism. Recent reports have indicated that PEPD protects p53 from uncontrolled p53 subcellular activation and its translocation between cellular compartments. PEPD also participates in the maturation of the interferon α/β receptor by regulating its expression. In addition to the biological effects, prolidase demonstrates clinical significance reflected in the disease known as prolidase deficiency. It is also known that prolidase activity is affected in collagen metabolism disorders, metabolic, and oncological conditions. In this article, we review the latest knowledge about prolidase and highlight its biological function, and thus provide an in-depth understanding of prolidase as a dipeptidase and protein regulating the function of key biomolecules in cellular metabolism.
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Szoka L, Karna E, Andrulewicz‐Botulinska E, Hlebowicz‐Sarat K, Palka JA. The mechanism for differential effect of nelfinavir and indinavir on collagen metabolism in human skin fibroblasts. Exp Dermatol 2019; 28:845-853. [DOI: 10.1111/exd.13956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 05/06/2019] [Indexed: 02/07/2023]
Affiliation(s)
- Lukasz Szoka
- Department of Medicinal Chemistry Medical University of Bialystok Bialystok Poland
| | - Ewa Karna
- Department of Medicinal Chemistry Medical University of Bialystok Bialystok Poland
| | | | | | - Jerzy A. Palka
- Department of Medicinal Chemistry Medical University of Bialystok Bialystok Poland
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Proline oxidase silencing induces proline-dependent pro-survival pathways in MCF-7 cells. Oncotarget 2018; 9:13748-13757. [PMID: 29568391 PMCID: PMC5862612 DOI: 10.18632/oncotarget.24466] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 02/01/2018] [Indexed: 11/28/2022] Open
Abstract
Proline degradation by proline dehydrogenase/proline oxidase (PRODH/POX) contributes to apoptosis or autophagy. The identification of specific pathway of apoptosis/survival regulation is the aim of this study. We generated knocked-down PRODH/POX MCF-7 breast cancer cells (MCF-7shPRODH/POX). PRODH/POX silencing did not affect cell viability. However, it contributed to decrease in DNA and collagen biosynthesis, increase in prolidase activity and intracellular proline concentration as well as increase in the expression of iNOS, NF-κB, mTOR, HIF-1α, COX-2, AMPK, Atg7 and Beclin-1 in MCF-7shPRODH/POX cells. In these cells, glycyl-proline (GlyPro, substrate for prolidase) further inhibited DNA and collagen biosynthesis, maintained high prolidase activity, intracellular concentration of proline and up-regulated HIF-1α, AMPK, Atg7 and Beclin-1, compared to GlyPro-treated MCF-7 cells. In MCF-7 cells, GlyPro increased collagen biosynthesis, concentration of proline and expression of caspase-3, cleaved caspases -3 and -9, iNOS, NF-κB, COX-2 and AMPKβ. PRODH/POX knock-down contributed to pro-survival autophagy pathways in MCF-7 cells and GlyPro-derived proline augmented this process. However, GlyPro induced apoptosis in PRODH/POX-expressing MCF-7 cells as detected by up-regulation of active caspases -3 and -9. The data suggest that PRODH/POX silencing induces autophagy in MCF-7 cells and GlyPro-derived proline supports this process.
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Szoka L, Karna E, Nazaruk J, Palka JA. Prolidase-dependent mechanism of (Z)-8,9-epoxyheptadeca-1,11,14-triene-induced inhibition of collagen biosynthesis in cultured human skin fibroblasts. Nat Prod Res 2015; 30:665-71. [PMID: 25982243 DOI: 10.1080/14786419.2015.1038535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The effects of polyolefinic compound from roots of Cirsium palustre, (Z)-8,9-epoxyheptadeca-1,11,14-triene (EHT) on collagen biosynthesis, prolidase activity, expression of insulin-like growth factor receptor (IGF-IR), β1 integrin, MAP kinases (pERK1/2), the transcription factors such as nuclear factor kappa B (NF-κB) and hypoxia-inducible factor-1α (HIF-1α) were evaluated in human dermal fibroblasts treated with micromolar concentrations (40-200 μM) for 24 h. It was found that EHT-dependent inhibition of collagen biosynthesis was accompanied by parallel inhibition in prolidase activity. Since IGF-I is the most potent regulator of both processes and prolidase is regulated by β1 integrin signalling, the effect of EHT on IGF-IR and β1 integrin receptor expressions were evaluated. Exposure of the cells to EHT contributed to distinct increase in IGF-IR and slight increase in β1 integrin receptor expressions. It was accompanied by decrease in expression of pERK1/2, HIF-1α and NF-κB. EHT-dependent inhibition of collagen biosynthesis results from inhibition of prolidase activity, the enzyme involved in collagen biosynthesis.
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Affiliation(s)
- Lukasz Szoka
- a Department of Medicinal Chemistry , Medical University of Bialystok , Mickiewicza 2d Street, 15-222 Bialystok , Poland
| | - Ewa Karna
- a Department of Medicinal Chemistry , Medical University of Bialystok , Mickiewicza 2d Street, 15-222 Bialystok , Poland
| | - Jolanta Nazaruk
- b Department of Pharmacognosy , Medical University of Bialystok , Mickiewicza 2a Street, 15-222 Bialystok , Poland
| | - Jerzy A Palka
- a Department of Medicinal Chemistry , Medical University of Bialystok , Mickiewicza 2d Street, 15-222 Bialystok , Poland
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Szoka L, Karna E, Morka RP, Palka JA. Enalapril stimulates collagen biosynthesis through prolidase-dependent mechanism in cultured fibroblasts. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:677-83. [PMID: 25772062 PMCID: PMC4438220 DOI: 10.1007/s00210-015-1114-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/04/2015] [Indexed: 12/21/2022]
Abstract
The mechanism of a lower incidence of dermatological manifestations in patients treated with enalapril compared to patients treated with other ACE-inhibitors, e.g., captopril, is not known. The finding that prolidase plays an important role in collagen biosynthesis and that some angiotensin-converting enzyme inhibitors affect prolidase activity led us to evaluate its effect on collagen biosynthesis in cultured human skin fibroblasts. Since insulin-like growth factor (IGF-I) and transforming growth factor beta 1 (TGF-β1) are the most potent stimulators of both collagen biosynthesis and prolidase activity, and prolidase is regulated by β1 integrin signaling, the effect of enalapril and enalaprilat on IGF-IR, TGF-β1, and β1 integrin receptor expressions was evaluated. Cells were treated with milimolar concentrations (0.3 and 0.5 mM) of enalapril and enalaprilat for 24 h. The activity of prolidase was determined by colorimetic assay. Collagen biosynthesis was evaluated by radiometric assay. Expression of signaling proteins was evaluated using Western blot. It was found that enalapril- and enalaprilat-dependent increase in prolidase activity and expression was accompanied by parallel increase in collagen biosynthesis. The exposure of the cells to 0.5 mM enalapril and enalaprilat contributed to increase in IGF-IR and α2β1 integrin receptor as well as TGF-β1 and NF-κB p65 expressions. Enalapril- and enalaprilat-dependent increase of collagen biosynthesis in fibroblasts results from increase of prolidase activity and expression, which may undergo through activation of α2β1 integrin and IGF-IR signaling as well as upregulation of TGF-β1 and NF-κB p65, the inhibitor of collagen gene expression.
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Affiliation(s)
- Lukasz Szoka
- Department of Medicinal Chemistry, Medical University in Bialystok, Mickiewicza 2 D, 15-222 Bialystok, Poland
| | - Ewa Karna
- Department of Medicinal Chemistry, Medical University in Bialystok, Mickiewicza 2 D, 15-222 Bialystok, Poland
| | - Renata Pawlak Morka
- Department of Medicinal Chemistry, Medical University in Bialystok, Mickiewicza 2 D, 15-222 Bialystok, Poland
| | - Jerzy A. Palka
- Department of Medicinal Chemistry, Medical University in Bialystok, Mickiewicza 2 D, 15-222 Bialystok, Poland
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The mechanism of hydralazine-induced collagen biosynthesis in cultured fibroblasts. Naunyn Schmiedebergs Arch Pharmacol 2013; 386:303-9. [PMID: 23344524 PMCID: PMC3597333 DOI: 10.1007/s00210-013-0836-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 01/14/2013] [Indexed: 11/26/2022]
Abstract
The finding that hydralazine (HYD) affects collagen metabolism led us to investigate the mechanism of its action on collagen biosynthesis, prolidase expression and activity, expression of α2β1 integrin, insulin-like growth factor-I receptor (IGF-IR), focal adhesion kinase (FAK), mitogen-activated protein (MAP) kinases (ERK1, ERK2), and transcription factors hypoxia-inducible factor-1α (HIF-1α) and nuclear factor-κB p65 (NF-κB p65) in human dermal fibroblasts. Confluent fibroblasts were treated with micromolar concentrations (50–500 μM) of HYD for 24 h. HYD had no influence on cell viability. It was found that HYD-dependent increase in collagen biosynthesis was accompanied by a parallel increase in prolidase activity and expression, HIF-1α expression, and decrease in DNA biosynthesis, compared to untreated cells. Since collagen biosynthesis and prolidase activity are regulated by a signal induced by activated α2β1 integrin receptor as well as IGF-IR, the expression of these receptors was measured by Western immunoblot analysis. The exposure of the cells to HYD contributed to the increase in IGF-IR expression without any effect on α2β1 integrin receptor and FAK expressions. It was accompanied by a decrease in expression of MAP kinases and NF-κB p65, the known inhibitor of collagen gene expression. The data suggest that the HYD-dependent increase of collagen biosynthesis in cultured human skin fibroblasts results from activation of IGF-IR expression and prolidase activity and downregulation of NF-κB p65.
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Karna E, Szoka L, Palka J. Thrombin-dependent modulation of β1-integrin-mediated signaling up-regulates prolidase and HIF-1α through p-FAK in colorectal cancer cells. Mol Cell Biochem 2011; 361:235-41. [PMID: 21993963 DOI: 10.1007/s11010-011-1108-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Accepted: 09/28/2011] [Indexed: 11/29/2022]
Abstract
Products of prolidase [E.C. 3.4.13.9] activity, proline or hydroxyproline, contribute to up-regulation of hypoxia-inducible factor-1α (HIF-1α). Prolidase activity is regulated by β(1)-integrin signaling. We studied the effects of echistatin (a well-known disintegrin) and thrombin (a serine protease capable of activation of integrin α(2)β(1) receptor) on prolidase activity and expressions of prolidase, α(2)β(1)-integrin receptor, focal adhesion kinase (FAK), MAP-kinases (ERK(1) and ERK(2)), and nuclear HIF-1α in human colon adenocarcinoma (DLD-1) cells. It has been found that treatment of the cells with thrombin contributes to decrease in the expression of prolidase and simultaneously increase in its phosphorylation, resulting in maintenance of the enzyme activity. The phenomenon was accompanied by thrombin-dependent recovery of depressed autophosphorylation of FAK (pY(397)) under the effect of FAK inhibitor (1,2,4,5-benzenetetramine tetrahydrochloride). Although integrin α(2)β(1) receptor expression was not affected by thrombin, the signaling induced by thrombin up-regulated nuclear HIF-1α expression. It was accompanied by increase in the expression of MAP kinases, ERK1 and ERK2. It suggests that integrin-dependent signaling through p-FAK is up-regulated in DLD-1 cells and it may represent potential target for anti-cancer therapy.
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Affiliation(s)
- Ewa Karna
- Department of Medicinal Chemistry, Medical University in Bialystok, Bialystok, Poland
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Jung S, Silvius D, Nolan KA, Borchert GL, Millet YH, Phang JM, Gunn TM. Developmental cardiac hypertrophy in a mouse model of prolidase deficiency. ACTA ACUST UNITED AC 2011; 91:204-17. [DOI: 10.1002/bdra.20789] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/11/2011] [Accepted: 01/13/2011] [Indexed: 11/09/2022]
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Jang J, Stella A, Boudou F, Levillain F, Darthuy E, Vaubourgeix J, Wang C, Bardou F, Puzo G, Gilleron M, Burlet-Schiltz O, Monsarrat B, Brodin P, Gicquel B, Neyrolles O. Functional characterization of the Mycobacterium tuberculosis serine/threonine kinase PknJ. MICROBIOLOGY-SGM 2010; 156:1619-1631. [PMID: 20185505 DOI: 10.1099/mic.0.038133-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Eukaryotic-like Ser/Thr protein kinases (STPKs) are present in many bacterial species, where they control various physiological and virulence processes by enabling microbial adaptation to specific environmental signals. PknJ is the only member of the 11 STPKs identified in Mycobacterium tuberculosis that still awaits characterization. Here we report that PknJ is a functional kinase that forms dimers in vitro, and contains a single transmembrane domain. Using a high-density peptide-chip-based technology, multiple potential mycobacterial targets were identified for PknJ. We confirmed PknJ-dependent phosphorylation of four of these targets: PknJ itself, which autophosphorylates at Thr(168), Thr(171) and Thr(173) residues; the transcriptional regulator EmbR; the methyltransferase MmaA4/Hma involved in mycolic acid biosynthesis; and the dipeptidase PepE, whose encoding gene is located next to pknJ in the mycobacterial genome. Our results provide a number of candidate phospho-targets for PknJ and possibly other mycobacterial STPKs that could be studied to investigate the role of STPKs in M. tuberculosis physiology and virulence.
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Affiliation(s)
- Jichan Jang
- Inserm Equipe Avenir Biology of Intracellular Pathogens, Institut Pasteur Korea, Seoul, Republic of Korea.,Unit of Mycobacterial Genetics, Institut Pasteur, Paris, France
| | - Alexandre Stella
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Frédéric Boudou
- Unit of Mycobacterial Genetics, Institut Pasteur, Paris, France
| | - Florence Levillain
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Eliette Darthuy
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Julien Vaubourgeix
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Chongzhen Wang
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Fabienne Bardou
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Germain Puzo
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Martine Gilleron
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Odile Burlet-Schiltz
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Bernard Monsarrat
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France
| | - Priscille Brodin
- Inserm Equipe Avenir Biology of Intracellular Pathogens, Institut Pasteur Korea, Seoul, Republic of Korea
| | | | - Olivier Neyrolles
- Université de Toulouse, Université Paul Sabatier, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale, F-31077 Toulouse, France.,Unit of Mycobacterial Genetics, Institut Pasteur, Paris, France
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Betulinic acid inhibits the expression of hypoxia-inducible factor 1α and vascular endothelial growth factor in human endometrial adenocarcinoma cells. Mol Cell Biochem 2010; 340:15-20. [DOI: 10.1007/s11010-010-0395-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Accepted: 02/03/2010] [Indexed: 11/26/2022]
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14
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Metabonomics study of liver cancer based on ultra performance liquid chromatography coupled to mass spectrometry with HILIC and RPLC separations. Anal Chim Acta 2009; 650:3-9. [PMID: 19720165 DOI: 10.1016/j.aca.2009.03.039] [Citation(s) in RCA: 175] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2008] [Revised: 02/28/2009] [Accepted: 03/20/2009] [Indexed: 01/28/2023]
Abstract
In this study, urinary metabolites from liver cancer patients and healthy volunteers were studied by a metabonomic method based on ultra performance liquid chromatography coupled to mass spectrometry. Both hydrophilic interaction chromatography (HILIC) and reversed-phase liquid chromatography (RPLC) were used to separate the urinary metabolites. Principle component analysis (PCA) and partial least squares to latent structure-discriminant analysis (PLS-DA) models were built to separate the healthy volunteers from the liver cancer patients and to find compounds that are expressed in significantly different amounts between the two populations. 21 metabolite ions were considered as potential biomarkers according to the Variable importance in the Project (VIP) value and S-plot. Compared with RPLC, a more sensitive and stable response can be recorded in HILIC mode due to the high content of organic solvent used. Moreover, the liver cancer group and the healthy volunteers can be better separated based on the data from the HILIC separation, which indicates that HILIC is suitable for urinary metabonomic analysis. In HILIC mode, several polar compounds related to arginine and proline metabolism, alanine and aspartate metabolism, lysine degradation, nicotinate and nicotinamide metabolism were found to be significantly changed in the concentrations of the two different populations: healthy and cancer. In contrast, in RPLC mode, these changed compounds are related to fatty acids oxidation.
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15
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Abstract
OBJECTIVES Prolidase is a cytosolic exopeptidase that cleaves iminodipeptides with carboxy-terminal proline or hydroxyproline and plays major role in collagen turnover. Collagen is the essential content in atherosclerotic plaque playing a key role in the stability/instability of and progression of coronary artery disease (CAD). Consequently, in this study we sought to determine serum prolidase activity and markers of oxidative stress such as lipid hydroperoxide and total free sulfhydryl in CAD. DESIGN AND METHODS We have evaluated 199 patients with CAD and 122 control cases with clinical, electrocardiographic, and laboratory investigation. We have measured serum prolidase activity and serum total free sulfhydryl levels spectrophotometrically. Serum lipid hydroperoxide levels were determined with ferrous ion oxidation-xylenol orange method. We assessed the association of serum prolidase activity with the presence and severity of CAD and clinical characteristics, and laboratory parameters. RESULTS Serum prolidase activity (52.5+/-5.6 vs. 46.7+/-5.1 U/l, respectively, P<0.001) and serum lipid hydroperoxide levels were significantly increased in patients with CAD compared with control cases whereas, serum total free sulfhydryl levels were significantly decreased in patients with CAD compared with control cases. Serum prolidase activity and total free sulfhydryl levels were independent predictors of the presence of CAD [(chi=75.532, ss=0.212, P=0.003) and (chi=25.969, ss=-30.486, P=0.019), respectively] and Gensini score [(beta=0.276, P<0.001) and (beta=-0.274, P<0.001), respectively]. Independent predictors of serum prolidase activity were serum high-density lipoprotein cholesterol (beta=-0.138, P=0.023) and urea levels (beta=0.146, P=0.036), and Gensini score (beta=0.317, P<0.001). CONCLUSION Findings of this study have shown that serum prolidase activity is significantly associated with the presence and severity of CAD, and elevated serum prolidase activity might be an independent predictor of coronary atherosclerosis.
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16
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Prolidase activity in serum and pleural fluids in patients with tuberculous pleural effussion. Clin Biochem 2008; 41:670-5. [DOI: 10.1016/j.clinbiochem.2008.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Revised: 03/07/2008] [Accepted: 03/08/2008] [Indexed: 11/22/2022]
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Karna E, Palka JA. Phosphoenolpyruvate-dependent inhibition of collagen biosynthesis, α2β1 integrin and IGF-I receptor signaling in cultured fibroblasts. Mol Cell Biochem 2008; 315:61-7. [DOI: 10.1007/s11010-008-9789-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 05/06/2008] [Indexed: 10/22/2022]
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18
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Lupi A, Tenni R, Rossi A, Cetta G, Forlino A. Human prolidase and prolidase deficiency: an overview on the characterization of the enzyme involved in proline recycling and on the effects of its mutations. Amino Acids 2008; 35:739-52. [DOI: 10.1007/s00726-008-0055-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Accepted: 02/07/2008] [Indexed: 10/22/2022]
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Demirbag R, Yildiz A, Gur M, Yilmaz R, Elçi K, Aksoy N. Serum prolidase activity in patients with hypertension and its relation with left ventricular hypertrophy. Clin Biochem 2007; 40:1020-5. [PMID: 17604013 DOI: 10.1016/j.clinbiochem.2007.05.015] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 05/23/2007] [Accepted: 05/29/2007] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The purpose of this study was to determine serum prolidase activity in patients with hypertension and its relation with left ventricular hypertrophy. DESIGN AND METHODS Serum prolidase activity was measured spectrophotometrically in hypertensive patients with (Group II, n=30) and without left ventricular hypertrophy (Group III, n=30) and in control group (Group I, n=30). RESULTS Prolidase activity was significantly lower in Group I than in Groups II and III (44.64+/-6.42 U/L vs. 54.14+/-6.30 U/L and 54.25+/-7.14 U/L, respectively; ANOVA, p<0.001). We revealed significant correlation between prolidase activity and presence and duration of hypertension (both of p<0.05) but not left ventricular mass index. Multivariate analysis shown that prolidase activity was significantly associated with age (beta=0.481, p<0.001) and duration of hypertension (beta=0.396, p<0.001). CONCLUSIONS Our data show that serum prolidase activity is associated with the presence hypertension independent of left ventricular hypertrophy.
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Affiliation(s)
- Recep Demirbag
- Department of Cardiology, Medical Faculty, Harran University, Sanliurfa, Turkiye, P.K: 112, Sanliurfa, Turkey.
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20
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Cechowska-Pasko M, Pałka J, Wojtukiewicz MZ. Enhanced prolidase activity and decreased collagen content in breast cancer tissue. Int J Exp Pathol 2006; 87:289-96. [PMID: 16875494 PMCID: PMC2517371 DOI: 10.1111/j.1365-2613.2006.00486.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Adherent interactions between integrins and extracellular matrix (ECM) proteins play an important role in tumorigenicity and invasiveness. The major component of ECM is collagen that plays a central role in the interaction with integrins. The expression of certain collagenases (gelatinases) by tumour cells is one of the characteristic features of the so-called metastatic phenotype, presumably by breaking down ECM barriers as well by altering the ECM-cell interaction. Although extracellular collagenases initiate the breakdown of collagen, the final step of collagen degradation is catalysed by intracellular prolidase. Collagen deposition, gelatinolytic and prolidase activities, expression of beta(1)-integrin receptor and their possible relationships were studied in seven operable breast cancer cases. In breast cancer tissue, we have found significant decrease in the amount of collagen. The decrease in collagen deposition in breast cancer tissue was accompanied by increase in the tissue gelatinolytic and prolidase activities. Simultaneously, a slight decrease in the expression of beta(1)-integrin receptor in breast cancer tissue was observed. These results suggest that alteration in collagen metabolism in breast cancer tissue may reflect tissue remodelling, characteristic for invasive phenotype of cancer cells. Increased gelatinolytic and prolidase activities in breast cancer tissue may enhance stromal matrix degradation and thus may promote metastatic dissemination. On the basis of the data, it seems that compounds endowed with gelatinolytic and prolidase inhibitory activities may be considered as a potential drug candidates for breast cancer therapy.
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Surazynski A, Liu Y, Miltyk W, Phang JM. Nitric oxide regulates prolidase activity by serine/threonine phosphorylation. J Cell Biochem 2006; 96:1086-94. [PMID: 16167338 DOI: 10.1002/jcb.20631] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Prolidase [E.C. 3.4.13.9], a member of the matrix metalloproteinase (MMP) family, is a manganese-dependent cytosolic exopeptidase that cleaves imidodipeptides containing C-terminal proline or hydroxyproline. It plays an important role in collagen metabolism, matrix remodeling and cell growth. Nitric oxide (NO), a versatile signaling molecule, regulates many processes including collagen synthesis and matrix remodeling and, thereby, may modulate angiogenesis, tumor invasiveness, and metastasis. Thus, we considered that prolidase may be an important target of NO regulation. In our study, SIN I and DETA/NO were used as NO donors. Both donors increased prolidase activity in a time-dependent and dose-dependent manner. Prolidase activity increased not only with NO donors but also with endogenous NO in cells transfected with iNOS. The effect of iNOS was abolished by treatment with S-methylisothiourea (SMT), a selective inhibitor of iNOS. However, with either exogenous or endogenous sources of NO, the increase in prolidase activity was not accompanied by increased prolidase expression. Therefore, we suspected phosphorylation of prolidase as a potential mechanism regulating enzyme activation. We observed increased serine/threonine phosphorylation on prolidase protein in cells treated with NO donors and in cells transfected with iNOS. To determinate the pathways that may mediate prolidase induction by NO, we first used 8-Br-cGMP, a cGMP agonist, and found that 8-Br-cGMP strongly and rapidly stimulated prolidase activity accompanied by increased phosphorylation. Rp-8-Br-pCPT-cGMP, an inhibitor of cGMP, reduced NO donor-stimulated prolidase activity to control levels. To test whether the MAPK pathway is involved in this NO-dependent activation, we used an ERK1/2 inhibitor and found that it had no effect on prolidase activity increased by NO donors. These results demonstrate that NO stimulates prolidase activity by increasing serine/threonine phosphorylation through PKG-cGMP pathway, but independent of MAPK and suggest an interaction between inflammatory signaling pathways and regulation of the terminal step of matrix degradation.
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Affiliation(s)
- Arkadiusz Surazynski
- Metabolism and Cancer Susceptibility Section, Laboratory of Comparative Carcinogenesis, National Cancer Institute at Frederick, Frederick, Maryland 21702, USA
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Karna E, Miltyk W, Pałka JA. Butyrate-induced collagen biosynthesis in cultured fibroblasts is independent on alpha2beta1 integrin signalling and undergoes through IGF-I receptor cascade. Mol Cell Biochem 2006; 286:147-52. [PMID: 16541197 DOI: 10.1007/s11010-005-9106-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Accepted: 12/08/2005] [Indexed: 10/24/2022]
Abstract
The potential role of butyrate to modulate cellular metabolism through integrin receptor led to evaluation of its effect on collagen biosynthesis in cultured fibroblasts. Confluent human dermal fibroblasts were treated with 2 mM and 4 mM of sodium butyrate (NaB) for 48 h. It was found that butyrate induced collagen biosynthesis and prolidase activity independently of alpha2beta1 integrin signaling. The expressions of both alpha2 and beta1 integrin subunits as well as integrin-induced activation of focal adhesion kinase (FAK) were not affected in the cells treated with NaB. Since insulin-like growth factor-I (IGF-I) is the most potent stimulator of collagen biosynthesis in fibroblasts, the effect of butyrate on IGF-I receptor (IGF-IR) expression was evaluated. It was found that the exposure of the cells to 4 mM butyrate contributed to a distinct increase in IGF-IR. It was accompanied by a parallel increase in the expression of Sos protein and MAP-kinases (ERK1, ERK2). The data suggests that butyrate-dependent stimulation of collagen biosynthesis in cultured human skin fibroblasts undergoes through IGF-IR signaling.
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Affiliation(s)
- Ewa Karna
- Department of Medicinal Chemistry, Medical University in Białystok, Kilińskiego 1, 15-089 Białystok, Poland
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Cechowska-Pasko M, Palka J, Bańkowski E. Fasting-induced inhibition of collagen biosynthesis in rat skin. A possible role for phosphoenolpyruvate in this process. Mol Cell Biochem 2005; 265:203-8. [PMID: 15543950 DOI: 10.1023/b:mcbi.0000044397.32748.23] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Fasting is accompanied by a decrease in collagen biosynthesis. The mechanism of this phenomenon involves inhibition of prolidase activity, an enzyme that plays a key role in upregulation of collagen metabolism. The mechanism of fasting-induced inhibition of prolidase activity is not known. Phosphoenolpyruvate (PEP) is known as a strong inhibitor of prolidase activity. It exerts this effect by inhibition of the enzyme phosphorylation. Unphosphorylated prolidase is inactive. One may expect that fasting-associated increase in posphoenolpyruvate content in animal tissues may be a factor which inactivates prolidase and makes it inactive in collagen biosynthesis. We measured the levels of phosphoenolpyruvate, pyruvate, and pyruvate kinase in the skin of control and fasted rats and correlated these parameters with prolidase expression, prolidase activity and collagen biosynthesis in this tissue. Significant increase of PEP concentration (about 30%) was found in the skin of fasted rats. In the same time prolidase activity and collagen biosynthesis decreased by about 50% and 30%, respectively, compared to controls. It is known that phosphoenolpyruvate is converted to pyruvate by the action of pyruvate kinase. Since fasting significantly decreases the activity of this enzyme, one may suggest that the accumulation of PEP is caused by a reduced utilisation of this metabolite. As demonstrated by Western immunoblot analysis the decrease in prolidase activity was not accompanied by a decrease in the amount of the enzyme protein. Instead, a decrease in the enzyme phosphorylation was observed. The reduction in phosphorylation seems to be responsible for the decrease in prolidase activity. These data suggest that fasting-evoked accumulation of PEP reduces the activity of prolidase, providing a mechanism for inhibition of collagen biosynthesis in the skin.
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Affiliation(s)
- Marzanna Cechowska-Pasko
- Department of Medical Biochemistry, Medical Academy of Bialystok, Mickiewicza, Bialystok, Poland.
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de Jesus Santana AS, de Carvalho-E-Silva SP, de Brito-Gitirana L. Structural aspects of an unusual choroidal polarized hyaline cartilage in the eyeball of Bufo ictericus and Rana catesbeiana (Amphibia, Anura): morphological and physiological significance. Micron 2004; 36:89-93. [PMID: 15582483 DOI: 10.1016/j.micron.2004.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2004] [Revised: 07/09/2004] [Accepted: 07/10/2004] [Indexed: 11/26/2022]
Abstract
Amphibian eyes play an important role in vision and in several physiological processes, such as food capture and breathing. To maintain the integrity of the eyeball there is a unique cuplike hyaline cartilage as a supporting tissue. In Bufo ictericus and Rana catesbeiana the cartilage layer is located between the retina and the choroids, being designated as choroidal cartilage, important to visual performance. On the retinal surface, there is no perichondrium, and the pigmented epithelium exhibits an intimate relationship to the cartilage layer.
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Affiliation(s)
- Andréa Souza de Jesus Santana
- Laboratory of Animal and Comparative Histology, Institute of Biological Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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Wrześniok D, Buszman E, Karna E, Nawrat P, Palka J. Melanin potentiates gentamicin-induced inhibition of collagen biosynthesis in human skin fibroblasts. Eur J Pharmacol 2002; 446:7-13. [PMID: 12098580 DOI: 10.1016/s0014-2999(02)01793-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
One of the recognized side effects of gentamicin is ototoxicity. The mechanism underlying the organ specificity of this side effect of gentamicin has not been fully established. In view of the fact that a number of pharmacologic agents are known to form complexes with melanin and melanin is an abundant constituent of the inner ear tissues, we determined whether gentamicin interacts with melanin and how this process affects the biosynthesis of collagen in cultured human skin fibroblasts. Our results indicate that gentamicin forms complexes with melanin. The amount of gentamicin bound to melanin increases with increasing of initial drug concentration. The Scatchard plot analysis of drug binding to melanin showed that at least two classes of independent binding sites are implicated in gentamicin-melanin complex formation: one class with an association constant K(1) approximately 4 x 10(3) M(-1), and the second class with an association constant K(2) approximately 3 x 10(2) M(-1). The number of total binding sites (n(1)+n(2)) was calculated as about 1.36 micromol gentamicin per 1 mg melanin. We have suggested that prolidase, an enzyme involved in collagen metabolism, may be one of the targets for gentamicin-induced inhibition of collagen biosynthesis. We found that gentamicin-induced inhibition of prolidase activity (IC(50) approximately 100 microM) and collagen biosynthesis (IC(50) approximately 100 microM). At this concentration of gentamicin, DNA biosynthesis in human skin fibroblasts was inhibited only by about 30%. Melanin at 100 microg/ml produced about 25% inhibition of DNA synthesis and about 30% inhibition of prolidase activity, but it had no effect on collagen biosynthesis in cultured fibroblasts. However, the addition of melanin (100 microg/ml) to gentamicin-treated cells (100 microM) augmented the inhibitory action of gentamicin on collagen and DNA biosynthesis and partially reversed its inhibitory effect on prolidase activity. A melanin-induced augmentation of the inhibitory effects of gentamicin on collagen and DNA biosynthesis may explain the mechanism for the organ specificity of gentamicin-induced hearing loss in patients administered this drug.
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Affiliation(s)
- Dorota Wrześniok
- Department of Pharmaceutical Chemistry, University Medical School of Silesia, Jagiellońska 4, 41-200, Sosnowiec, Poland
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