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da Silva CN, Nunes KP, Dourado LFN, Vieira TO, Mariano XM, Cunha Junior ADS, de Lima ME. From the PnTx2-6 Toxin to the PnPP-19 Engineered Peptide: Therapeutic Potential in Erectile Dysfunction, Nociception, and Glaucoma. Front Mol Biosci 2022; 9:831823. [PMID: 35480885 PMCID: PMC9035689 DOI: 10.3389/fmolb.2022.831823] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/21/2022] [Indexed: 11/13/2022] Open
Abstract
The venom of the “armed” spider Phoneutria nigriventer comprises several potent toxins. One of the most toxic components from this venom is the neurotoxin PnTx2-6 (LD50 = ∼ 0.7 μg/mouse, 48 residues, five disulfide bridges, MW = 5,289.31 Da), which slows down the inactivation of various Na+ channels. In mice and rats, this toxin causes priapism, an involuntary and painful erection, similar to what is observed in humans bitten by P. nigriventer. While not completely elucidated, it is clear that PnTx2-6 potentiates erectile function via NO/cGMP signaling, but it has many off-target effects. Seeking to obtain a simpler and less toxic molecule able to retain the pharmacological properties of this toxin, we designed and synthesized the peptide PnPP-19 (19 residues, MW = 2,485.6 Da), representing a discontinuous epitope of PnTx2-6. This synthetic peptide also potentiates erectile function via NO/cGMP, but it does not target Na+ channels, and therefore, it displays nontoxic properties in animals even at high doses. PnPP-19 effectively potentiates erectile function not only after subcutaneous or intravenous administration but also following topical application. Surprisingly, PnPP-19 showed central and peripheral antinociceptive activity involving the opioid and cannabinoid systems, suggesting applicability in nociception. Furthermore, considering that PnPP-19 increases NO availability in the corpus cavernosum, this peptide was also tested in a model of induced intraocular hypertension, characterized by low NO levels, and it showed promising results by decreasing the intraocular pressure which prevents retinal damage. Herein, we discuss how was engineered this smaller active non-toxic peptide with promising results in the treatment of erectile dysfunction, nociception, and glaucoma from the noxious PnTx2-6, as well as the pitfalls of this ongoing journey.
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Affiliation(s)
- Carolina Nunes da Silva
- Departmentamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- *Correspondence: Maria Elena de Lima, ; Carolina Nunes da Silva, ; Kenia Pedrosa Nunes,
| | - Kenia Pedrosa Nunes
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL, United States
- *Correspondence: Maria Elena de Lima, ; Carolina Nunes da Silva, ; Kenia Pedrosa Nunes,
| | | | - Thayllon Oliveira Vieira
- Programa de Pós-Graduação em Medicina e Biomedicina Faculdade Santa Casa de Belo Horizonte, Belo Horizonte, Brazil
| | - Xavier Maia Mariano
- Programa de Pós-Graduação em Medicina e Biomedicina Faculdade Santa Casa de Belo Horizonte, Belo Horizonte, Brazil
| | | | - Maria Elena de Lima
- Departmentamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Programa de Pós-Graduação em Medicina e Biomedicina Faculdade Santa Casa de Belo Horizonte, Belo Horizonte, Brazil
- *Correspondence: Maria Elena de Lima, ; Carolina Nunes da Silva, ; Kenia Pedrosa Nunes,
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The synthetic peptide PnPP-19 potentiates erectile function via nNOS and iNOS. Nitric Oxide 2021; 113-114:23-30. [PMID: 33915274 DOI: 10.1016/j.niox.2021.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 01/27/2023]
Abstract
PnPP-19 peptide has a primary sequence design based on molecular modeling studies of PnTx2-6 toxin. It comprises the amino acid residues that are potentially significant for the pharmacological action of PnTx2-6. Ex vivo and in vivo experiments in normotensive, hypertensive, or diabetic murine models have shown a significant improvement in penile erection after administration of PnPP-19. Given the potential use of PnPP-19 in pharmaceutical formulations to treat erectile dysfunction and the lack of information concerning its mode of action, the present work investigates its activities on the nitrergic system. PnPP-19 induced a significant increase in nitric oxide (NO) and cGMP levels in corpus cavernosum (cc). These effects were inhibited by l-NAME, a non-selective inhibitor of nitric oxide synthase (NOS); were partially inhibited by 7- Nitroindazole, a selective inhibitor of neuronal NOS (nNOS); and were abolished by L-NIL, a selective inhibitor of inducible NOS (iNOS). This potentiating effect was not affected by atropine. PnPP-19 also led to changes in mRNA levels, protein expression and phosphorylation at specific sites of NOS, in cc. Assays using cavernous tissue from knockout mice to endothelial NOS (eNOS), nNOS or iNOS showed that PnPP-19 potentiates relaxation only in eNOS-knockout mice, which suggests an essential role for nNOS. Surprisingly, iNOS enhanced the potentiation of erectile function evoked by PnPP-19. Our results demonstrate that this new synthetic peptide potentiates erectile function via nitric oxide activation and reinforce its role as a new pharmacological tool for the treatment of erectile dysfunction.
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Scherzer ND, Reddy AG, Le TV, Chernobylsky D, Hellstrom WJG. Unintended Consequences: A Review of Pharmacologically-Induced Priapism. Sex Med Rev 2018; 7:283-292. [PMID: 30503727 DOI: 10.1016/j.sxmr.2018.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/14/2018] [Accepted: 09/16/2018] [Indexed: 01/30/2023]
Abstract
BACKGROUND Priapism has been linked to many commonly prescribed medications, as well as recreational drugs and toxins. Although the incidence of priapism as a result of medication is small, the increasing use of antidepressants, antipsychotics, and recreational drugs may lead to more cases of pharmacologically-induced priapism in the future. AIM To provide a comprehensive, up-to-date review of the most common causes of pharmacologically induced priapism and discuss incidence, pathophysiology, and basic management strategies. METHODS A review of the available literature from 1960 to 2018 was performed using PubMed with regards to pharmacologically induced priapism. MAIN OUTCOME MEASURE We reviewed publications that outlined incidence, pathophysiology, and management strategies for various pharmacologic causes of priapism: antidepressants, antipsychotics, antihypertensives, methylphenidate, cocaine, heparin, gonadotropin-releasing hormone, propofol, spider bites, and other miscellaneous causes. RESULTS An understanding of the pathophysiology behind common pharmacologic causes of priapism can assist in the development of better treatment strategies and prevent future episodes of priapism. By understanding the potential risks associated with the use of medications with α-blocking or sympathomimetic properties, physicians can reduce the likelihood of priapism in their patients, especially those with other medical conditions that put them at increased baseline risk. Early corporal aspiration and injection of phenylephrine reduces additional complications related to priapism. In select patients, early placement of a penile prosthesis may prevent further morbidity. CONCLUSION By developing a greater understanding of common pharmacologic causes of priapism, physicians can promptly identify and manage symptoms, leading to decreased patient morbidity. Scherzer ND, Reddy AG, Le TV, Chernobylsky D, Hellstrom WJG. Unintended Consequences: A Review of Pharmacologically-Induced Priapism. Sex Med Rev 2019;7:283-292.
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Affiliation(s)
| | - Amit G Reddy
- Department of Urology, Tulane University, New Orleans, LA, USA
| | - Tan V Le
- Department of Urology, Tulane University, New Orleans, LA, USA; Department of Andrology, Binh Dan Hospital, Ho Chi Minh City, Vietnam
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Nunes KP, de Oliveira AA, Szasz T, Biancardi VC, Webb RC. Blockade of Toll-Like Receptor 4 Attenuates Erectile Dysfunction in Diabetic Rats. J Sex Med 2018; 15:1235-1245. [DOI: 10.1016/j.jsxm.2018.07.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 07/02/2018] [Accepted: 07/06/2018] [Indexed: 12/19/2022]
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Peigneur S, de Lima ME, Tytgat J. Phoneutria nigriventer venom: A pharmacological treasure. Toxicon 2018; 151:96-110. [DOI: 10.1016/j.toxicon.2018.07.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/27/2018] [Accepted: 07/05/2018] [Indexed: 12/15/2022]
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PnTx2-6 (or δ-CNTX-Pn2a), a toxin from Phoneutria nigriventer spider venom, releases l-glutamate from rat brain synaptosomes involving Na+ and Ca2+ channels and changes protein expression at the blood-brain barrier. Toxicon 2018; 150:280-288. [DOI: 10.1016/j.toxicon.2018.06.073] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 06/12/2018] [Accepted: 06/14/2018] [Indexed: 11/18/2022]
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Ma B, Xi Z, Li J, Gao T, Liao R, Wang S, Li X, Tang Y, Wang Z, Hou S, Jiang J, Deng M, Duan Z, Tang X, Jiang L. Vasodilator and hypotensive effects of the spider peptide Lycosin-I in vitro and in vivo. Peptides 2018; 99:108-114. [PMID: 29248696 DOI: 10.1016/j.peptides.2017.12.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 12/11/2017] [Accepted: 12/12/2017] [Indexed: 11/23/2022]
Abstract
Lycosin-I, a spider peptide isolated from the venom of the spider Lycosa singoriensis, has anti-bacteria and anti-cancer properties in organisms. However, cardiovascular effects of Lycosin-I have not been studied. In this study, we investigated for the first time the vasodilator and hypotensive effects of Lycosin-I and the possible mechanisms, in order to develop a promising treatment for hypertension-related diseases. For in vitro experiments, thoracic aortas were isolated, and divided into two groups, endothelium-intact and endothelium-denuded aortic rings. Lycosin-I induced a remarkable dose-dependent relaxation in endothelium-intact aortic rings pre-treated with phenylephrine (p < 0.05), while it showed no obvious vasodilator effects in endothelium-denuded aortic rings (p > 0.05). The vasodilator effects of Lycosin-I were significantly weakened by a nitric oxide synthase (NOS) inhibitor, L-NAME (p < 0.001) and a selective inhibitor of nitric oxide (NO)-sensitive soluble guanylate cyclase (sGC), ODQ (p < 0.05), respectively. The levels of endothelial nitric oxide synthase (eNOS) phosphorylation and the NO production were significantly higher in human umbilical vascular endothelial cells pre-cultured with Lycosin-I than the control (p < 0.001), determined via western blot analysis and ozone-chemiluminescence technology. For in vivo experiments, arterial and venous catheters were inserted for mean arterial pressure (MAP) recording and drug administration in anaesthetized spontaneously hypertensive rats. Lycosin-I caused a transient drop of MAP 2 min after the administration compared with the control (p < 0.001). In conclusion, Lycosin-I has the potential to be an anti-hypertensive drug by endothelium-dependent vasodilatation, in which eNOS and NO-sensitive sGC are two main involved factors.
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Affiliation(s)
- Binbin Ma
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Zhouhuan Xi
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Jiahui Li
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Tianqi Gao
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Runzhi Liao
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Shuhang Wang
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Xianyao Li
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Yaqin Tang
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Zheng Wang
- The First Department of General Surgery, the Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, PR China
| | - Shengjie Hou
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China
| | - Jinying Jiang
- Department of Neonatology, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, Hunan 410013, PR China
| | - Meichun Deng
- Department of Biochemistry, School of Life Sciences, Central South University, Changsha, Hunan 410013, PR China
| | - Zhigui Duan
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, PR China
| | - Xing Tang
- College of Chemistry, Biology, and Material Science, East China Institute of Technology, Nanchang, Jiangxi 330013, PR China
| | - Liping Jiang
- Department of Parasitology, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, PR China.
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Freitas ACN, Silva GC, Pacheco DF, Pimenta AMC, Lemos VS, Duarte IDG, de Lima ME. The synthetic peptide PnPP-19 induces peripheral antinociception via activation of NO/cGMP/K ATP pathway: Role of eNOS and nNOS. Nitric Oxide 2017; 64:31-38. [PMID: 28087360 DOI: 10.1016/j.niox.2017.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 01/19/2023]
Abstract
BACKGROUND and purpose: The peptide PnPP-19, derived from the spider toxin PnTx2-6 (renamed as δ-CNTX-Pn1c), potentiates erectile function by activating the nitrergic system. Since NO has been studied as an antinociceptive molecule and PnPP-19 is known to induce peripheral antinociception, we intended to evaluate whether PnPP-19 could induce peripheral antinociception through activation of this pathway. EXPERIMENTAL APPROACH Nociceptive thresholds were measured by paw pressure test. PGE2 (2 μg/paw) was administered intraplantarly together with PnPP-19 and inhibitors/blockers of NOS, guanylyl cyclase and KATP channels. The nitrite concentration was accessed by Griess test. The expression and phosphorylation of eNOS and nNOS were determined by western blot. KEY RESULTS PnPP-19 (5, 10 and 20 μg/paw) induced peripheral antinociception in rats. Administration of NOS inhibitor (L-NOarg), selective nNOS inhibitor (L-NPA), guanylyl cyclase inhibitor (ODQ) and the blocker of KATP (glibenclamide) partially inhibited the antinociceptive effect of PnPP-19 (10 μg/paw). Tissue nitrite concentration increased after PnPP-19 (10 μg/paw) administration. Expression of eNOS and nNOS remained the same in all tested groups, however the phosphorylation of nNOS Ser852 (inactivation site) increased and phosphorylation of eNOS Ser1177 (activation site) decreased after PGE2 injection. Administration of PnPP-19 reverted this PGE2-induced effect. CONCLUSIONS AND IMPLICATIONS The peripheral antinociceptive effect induced by PnPP-19 is resulting from activation of NO-cGMP-KATP pathway. Activation of eNOS and nNOS might be required for such effect. Our results suggest PnPP-19 as a new drug candidate to treat pain and reinforce the importance of nNOS and eNOS activation, as well as endogenous NO release, for induction of peripheral antinociception.
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Affiliation(s)
- A C N Freitas
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil
| | - G C Silva
- Departamento Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil
| | - D F Pacheco
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil; Departamento Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil
| | - A M C Pimenta
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil
| | - V S Lemos
- Departamento Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil
| | - I D G Duarte
- Departamento Farmacologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil
| | - M E de Lima
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, M.G., Brazil.
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Borges MH, Figueiredo SG, Leprevost FV, De Lima ME, Cordeiro MDN, Diniz MR, Moresco J, Carvalho PC, Yates JR. Venomous extract protein profile of Brazilian tarantula Grammostola iheringi : searching for potential biotechnological applications. J Proteomics 2016; 136:35-47. [DOI: 10.1016/j.jprot.2016.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 12/21/2015] [Accepted: 01/25/2016] [Indexed: 02/06/2023]
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Silva CN, Nunes KP, Torres FS, Cassoli JS, Santos DM, Almeida FDM, Matavel A, Cruz JS, Santos-Miranda A, Nunes ADC, Castro CH, Machado de Ávila RA, Chávez-Olórtegui C, Láuar SS, Felicori L, Resende JM, Camargos ERDS, Borges MH, Cordeiro MN, Peigneur S, Tytgat J, de Lima ME. PnPP-19, a Synthetic and Nontoxic Peptide Designed from a Phoneutria nigriventer Toxin, Potentiates Erectile Function via NO/cGMP. J Urol 2015; 194:1481-90. [PMID: 26119670 DOI: 10.1016/j.juro.2015.06.081] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2015] [Indexed: 01/09/2023]
Abstract
PURPOSE We designed a peptide, PnPP-19, comprising the potential active core of the Phoneutria nigriventer native toxin PnTx2-6. We investigated its role on erectile function, and its toxicity and immunogenicity. MATERIALS AND METHODS Erectile function was evaluated by the intracavernous pressure-to-mean arterial pressure ratio during electrical field stimulation on rat pelvic ganglia. Cavernous strips were contracted with phenylephrine and relaxation was induced by electrical field stimulation with or without PnPP-19 (10(-8) M). Activity on sodium channels was evaluated by electrophysiological screening of transfected channels on Xenopus oocytes and dorsal root ganglion cells. Antibodies were detected by indirect enzyme-linked immunosorbent assay in mice previously treated with the peptide. Histopathological studies were performed with mouse organs treated with different doses of PnPP-19. RESULTS PnPP-19 was able to potentiate erection at 4 and 8 Hz in vivo and ex vivo. It showed no toxicity and low immunogenicity in mice, and did not affect sodium channels or rat hearts. PnPP-19 increased cyclic guanosine monophosphate levels at 8 Hz. This effect was inhibited by L-NAME (10(-4) M). Erectile function was partially inhibited by 7-nitroindazole (10(-5) M), a selective inhibitor of neuronal nitric oxide synthase. CONCLUSIONS PnPP-19 potentiates erection in vivo and ex vivo via the nitric oxide/cyclic guanosine monophosphate pathway. It does not affect sodium channels or rat hearts and shows no toxicity and low immunogenicity. These findings make it a promising candidate as a novel drug in the therapy of erectile dysfunction.
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Affiliation(s)
- Carolina Nunes Silva
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Kenia Pedrosa Nunes
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Fernanda Silva Torres
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Juliana Silva Cassoli
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniel Moreira Santos
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Flávia De Marco Almeida
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Jader Santos Cruz
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Arthur Santos-Miranda
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | - Carlos Chávez-Olórtegui
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Stephanie Stransky Láuar
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Liza Felicori
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | | | | | | | - Steve Peigneur
- Toxicology and Pharmacology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Maria Elena de Lima
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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Jung AR, Choi YS, Piao S, Park YH, Shrestha KR, Jeon SH, Hong SH, Kim SW, Hwang TK, Kim KH, Lee JY. The effect of PnTx2-6 protein from Phoneutria nigriventer spider toxin on improvement of erectile dysfunction in a rat model of cavernous nerve injury. Urology 2014; 84:730.e9-17. [PMID: 25168567 DOI: 10.1016/j.urology.2014.05.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 05/01/2014] [Accepted: 05/23/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVE To explore the therapeutic potential of PnTx2-6 injected 3 times a week for 4 weeks into the intracavernosal tissue in a rat model of bilateral cavernous nerve crush injury (BCNI). METHODS Eight-week-old male Sprague-Dawley rats were randomly divided into the following 6 groups (n = 5 per group): age-matched control (normal group), BCNI (injury group), post-BCNI phosphate-buffered saline injection (PBS group), post-BCNI Sf9 cell-lysate injection (N/C group), post-BCNI injection of cell lysate from S9 cells infected with wild-type recombinant baculovirus (W/T group), and post-BCNI injection of cell lysate from S9 cells infected with recombinant baculovirus containing PnTx2-6 (PnTx2-6 group). Injections were delivered 3 times a week for 4 weeks. After 4 weeks, intracavernosal pressure-to-mean arterial pressure ratio, smooth muscle and collagen content via the Masson trichrome staining, levels of neural nitric oxide synthase, phosphoendothelial nitric oxide synthase, and cyclic guanosine monophosphate were all measured. RESULTS The PnTx2-6 group showed significantly higher intracavernosal pressure-to-mean arterial pressure ratio (P <.05), smooth muscle-to-collagen ratio (P <.01), expression levels of neural nitric oxide synthase, phosphoendothelial nitric oxide synthase (P <.05), and cyclic guanosine monophosphate (P <.05) than all other experimental groups. CONCLUSION We conclude that PnTx2-6 improved erectile function and prevented muscle atrophy in a rat model of BCNI via increased synthesis of nitric oxide and cyclic guanosine monophosphate.
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Affiliation(s)
- Ae Ryang Jung
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Yong Sun Choi
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Shuyu Piao
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Yong Hyun Park
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Kshitiz Raj Shrestha
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Seung Hwan Jeon
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Sung-Hoo Hong
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Sae Woong Kim
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Tae-Kon Hwang
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Ki Hean Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, Gyengbuk, Republic of Korea
| | - Ji Youl Lee
- Department of Urology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.
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Triggering of protection mechanism against Phoneutria nigriventer spider venom in the brain. PLoS One 2014; 9:e107292. [PMID: 25211468 PMCID: PMC4161398 DOI: 10.1371/journal.pone.0107292] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 08/11/2014] [Indexed: 01/03/2023] Open
Abstract
Severe accidents caused by the "armed" spider Phoneutria nigriventer cause neurotoxic manifestations in victims. In experiments with rats, P. nigriventer venom (PNV) temporarily disrupts the properties of the BBB by affecting both the transcellular and the paracellular route. However, it is unclear how cells and/or proteins participate in the transient opening of the BBB. The present study demonstrates that PNV is a substrate for the multidrug resistance protein-1 (MRP1) in cultured astrocyte and endothelial cells (HUVEC) and increases mrp1 and cx43 and down-regulates glut1 mRNA transcripts in cultured astrocytes. The inhibition of nNOS by 7-nitroindazole suggests that NO derived from nNOS mediates some of these effects by either accentuating or opposing the effects of PNV. In vivo, MRP1, GLUT1 and Cx43 protein expression is increased differentially in the hippocampus and cerebellum, indicating region-related modulation of effects. PNV contains a plethora of Ca(2+), K(+) and Na(+) channel-acting neurotoxins that interfere with glutamate handling. It is suggested that the findings of the present study are the result of a complex interaction of signaling pathways, one of which is the NO, which regulates BBB-associated proteins in response to PNV interference on ions physiology. The present study provides additional insight into PNV-induced BBB dysfunction and shows that a protective mechanism is activated against the venom. The data shows that PNV has qualities for potential use in drug permeability studies across the BBB.
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Decaluwé K, Pauwels B, Boydens C, Van de Voorde J. Treatment of erectile dysfunction: new targets and strategies from recent research. Pharmacol Biochem Behav 2013; 121:146-57. [PMID: 24291648 DOI: 10.1016/j.pbb.2013.11.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/18/2013] [Indexed: 12/15/2022]
Abstract
In recent years, research on penile erection has increasingly been centered on the molecular mechanisms involved. Major progress has been made in the field and at present a whole number of neurotransmitters, chemical effectors, growth factors, second-messenger molecules, ions, intercellular proteins, and hormones have been characterized as components of the complex process of erection. This knowledge has led to the discovery of several new therapeutic targets and multiple medical approaches for the treatment of erectile dysfunction (ED). This review focuses on the progress made in this field within the last few years.
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Affiliation(s)
- K Decaluwé
- Department of Pharmacology, Ghent University, Ghent, Belgium
| | - B Pauwels
- Department of Pharmacology, Ghent University, Ghent, Belgium
| | - C Boydens
- Department of Pharmacology, Ghent University, Ghent, Belgium
| | - J Van de Voorde
- Department of Pharmacology, Ghent University, Ghent, Belgium.
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Fraga-Silva RA, Costa-Fraga FP, Savergnini SQ, De Sousa FB, Montecucco F, da Silva D, Sinisterra RD, Mach F, Stergiopulos N, da Silva RF, Santos RAS. An oral formulation of angiotensin-(1-7) reverses corpus cavernosum damages induced by hypercholesterolemia. J Sex Med 2013; 10:2430-42. [PMID: 23890028 DOI: 10.1111/jsm.12262] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
INTRODUCTION The renin angiotensin system plays a crucial role in erectile function. It has been shown that elevated angiotensin-II levels contribute to the development of erectile dysfunction (ED). Oppositely, angiotensin-(1-7) (Ang-[1-7]) mediates penile erection by activation of receptor Mas. Recently, we have developed a formulation based on Ang-(1-7) inclusion in cyclodextrin (CyD) [Ang-(1-7)-CyD], which allows for the oral administration of Ang-(1-7). AIM In the present study, we evaluated the effects of chronic treatment with Ang-(1-7)-CyD on penile fibrosis, oxidative stress, and endothelial function in hypercholesterolemic mice. METHODS Apolipoprotein(Apo)E-/- mice fed a Western-type diet for 11 weeks received Ang-(1-7)-CyD or vehicle during the final 3 weeks. Collagen content and reactive oxygen species (ROS) production within the corpus cavernosum were evaluated by Sirius red and dihydroethidium staining, respectively. Protein expression of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS), nicotinamide adenine dinucleotide phosphate (NADPH) subunits (p67-phox and p22-phox), and AT1 and Mas receptors in the penis was assessed by Western blotting. Nitric oxide (NO) production was measured by Griess assay in the mice serum. Cavernosal strips were mounted in an isometric organ bath to evaluate the endothelial function. MAIN OUTCOME MEASURES The effect of Ang-(1-7)-CyD treatment on penile fibrosis, oxidative stress, and endothelial function in hypercholesterolemia-induced ED. RESULTS Ang-(1-7)-CyD treatment reduced collagen content in the corpus cavernosum of ApoE-/- mice. This effect was associated with an attenuation of ROS production and a diminished expression of NADPH. Furthermore, Ang-(1-7)-CyD treatment augmented the expression of nNOS and eNOS in the penis and elevated vascular NO production. Importantly, these effects were accompanied by an improvement in cavernosal endothelial function. CONCLUSION Long-term treatment with Ang-(1-7)-CyD reduces penile fibrosis associated with attenuation of oxidative stress. Additionally, cavernosal endothelial function in hypercholesterolemic mice was markedly improved. These results suggest that Ang-(1-7)-CyD might have significant therapeutic benefits for the treatment of erectile dysfunction.
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Affiliation(s)
- Rodrigo A Fraga-Silva
- Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Nunes KP, Torres FS, Borges MH, Matavel A, Pimenta AM, De Lima ME. New insights on arthropod toxins that potentiate erectile function. Toxicon 2013; 69:152-9. [DOI: 10.1016/j.toxicon.2013.03.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 02/21/2013] [Accepted: 03/22/2013] [Indexed: 12/19/2022]
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Nunes KP, Toque HA, Borges MH, Richardson M, Webb RC, de Lima ME. Erectile function is improved in aged rats by PnTx2-6, a toxin from Phoneutria nigriventer spider venom. J Sex Med 2012; 9:2574-81. [PMID: 22925420 DOI: 10.1111/j.1743-6109.2012.02878.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Age-associated erectile dysfunction (ED) involves a decrease in nitric oxide (NO) availability and impaired relaxation. PnTx2-6, a toxin from the Phoneutria nigriventer spider, has been demonstrated to improve erectile function via NO/cyclic guanosine monophosphate (cGMP) pathway. This spider's venom is characterized by several symptoms, including erection. PnTx2-6 has been implicated in this phenomenon. Animal venoms have been postulated as potential drugs to treat ED. AIM PnTx2-6 toxin improves erectile function in aged rats via NO/cGMP. We investigated the effect of PnTx2-6 in the erectile function of aged rats. MAIN OUTCOME MEASURES ED was evaluated through changes in intracavernosal pressure/mean arterial pressure ratio during electrical field stimulation (EFS) of the pelvic ganglion of aged and adult rats (70 vs. 14 weeks). In functional studies, EFS-induced relaxation of corpus cavernosum (CC) strips were performed with or without PnTx2-6 (10-8M). RESULTS The decrease in erectile function associated with age was partially restored 15-20 minutes after injection of PnTx2-6 and further improved by sildenafil. PnTx2-6 enhanced EFS-induced relaxation, as well as cGMP levels in CC, from young and aged rats. Relaxation due to PnTx2-6 was further increased after 30 minutes incubation with Y-27632, a Rho-kinase inhibitor (10-6 M), in aging CC. Nitric oxide synthase (NOS) activity in aged and young cavernosal tissue was increased by incubation with PnTx2-6 (10 minutes). However, this toxin did not modify NOS expression. CONCLUSION PnTx2-6 improves penile relaxation in aged rats, via increased NOS activity and NO release, resulting in enhanced cGMP levels.
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Affiliation(s)
- Kenia P Nunes
- Department of Physiology, Georgia Health Sciences University, Augusta, GA, USA.
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