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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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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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Ravelli KG, Ramos ADT, Gonçalves LB, Magnoli FC, Troncone LRP. Phoneutria nigriventer spider toxin Tx2-6 induces priapism in mice even after cavernosal denervation. Toxicon 2017; 130:29-34. [DOI: 10.1016/j.toxicon.2017.02.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 01/27/2017] [Accepted: 02/23/2017] [Indexed: 01/11/2023]
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El-Tantawy NL. Helminthes and insects: maladies or therapies. Parasitol Res 2014; 114:359-77. [PMID: 25547076 DOI: 10.1007/s00436-014-4260-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 12/15/2014] [Indexed: 11/24/2022]
Abstract
By definition, parasites cause harm to their hosts. But, considerable evidence from ancient traditional medicine has supported the theory of using parasites and their products in treating many diseases. Maggots have been used successfully to treat chronic, long-standing, infected wounds which failed to respond to conventional treatment by many beneficial effects on the wound including debridement, disinfection, and healing enhancement. Maggots are also applied in forensic medicine to estimate time between the death and discovery of a corpse and in entomotoxicology involving the potential use of insects as alternative samples for detecting drugs and toxins in death investigations. Leeches are segmented invertebrates, famous by their blood-feeding habits and used in phlebotomy to treat various ailments since ancient times. Leech therapy is experiencing resurgence nowadays in health care principally in plastic and reconstructive surgery. Earthworms provide a source of medicinally useful products with potential antimicrobial, antiviral, and anticancer properties. Lumbrokinases are a group of fibrinolytic enzymes isolated and purified from earthworms capable of degrading plasminogen-rich and plasminogen-free fibrin and so can be used to treat various conditions associated with thrombotic diseases. Helminth infection has been proved to have therapeutic effects in both animal and human clinical trials with promising evidence in treating many allergic diseases and can block the induction of or reduce the severity of some autoimmune disorders as Crohn's disease or ulcerative colitis. What is more, venomous arthropods such as scorpions, bees, wasps, spiders, ants, centipedes, snail, beetles, and caterpillars. The venoms and toxins from these arthropods provide a promising source of natural bioactive compounds which can be employed in the development of new drugs to treat diseases as cancer. The possibility of using these active molecules in biotechnological processes can make these venoms and toxins a valuable and promising source of natural bioactive compounds. The therapeutic use of helminthes and insects will be of great value in biomedicine and further studies on insect toxins will contribute extensively to the development of Biomedical Sciences.
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Affiliation(s)
- Nora L El-Tantawy
- Department of Medical Parasitology, Faculty of Medicine, Mansoura University, 2 El-Gomhouria Street, Mansoura, 35516, Egypt,
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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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Nunes KP, Wynne BM, Cordeiro MN, Borges MH, Richardson M, Leite R, DeLima ME, Webb RC. Increased cavernosal relaxation by Phoneutria nigriventer toxin, PnTx2-6, via activation at NO/cGMP signaling. Int J Impot Res 2011; 24:69-76. [PMID: 21975567 PMCID: PMC3253321 DOI: 10.1038/ijir.2011.47] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Erectile dysfunction mechanisms in diabetic patients are multifactorial and often lead to resistance to current therapy. Animal toxins have been used as pharmacological tools to study penile erection. Human accidents involving the venom of Phoneutria nigriventer spider are characterized by priapism. We hypothesize that PnTx2-6 potentiates cavernosal relaxation in diabetic mice by increasing cGMP. This effect is nNOS dependent. Cavernosal strips were contracted with phenylephrine (10−5 M) and relaxed by electrical field stimulation (EFS, 20V, 1–32 Hz) in the presence or absence of PnTx2-6 (10−8 M).Cavernosal strips from nNOS and eNOS knocaut (KO) mice, besides nNOS inhibitor (10−5M), were used to evaluate the role of this enzyme in the potentiation effect evoked by PnTx2-6. Tissue cGMP levels were determined after stimulation with PnTx2-6 in presence or absence of L-NAME (10−4M) and ω-conotoxin GVIA (10−6M), an N-type calcium channel inhibitor. Results showed PnTx2-6 enhanced cavernosal relaxation in diabetic mice (65%) and eNOS KO mice, but not in nNOS KO mice. The toxin effect in the cavernosal relaxation was abolished by nNOS inhibitor. cGMP levels are increased by PnTx2-6, however L-NAME abolished this enhancement as well as ω-conotoxin GVIA. We conclude PnTx2-6 facilitates penile relaxation in diabetic mice through a mechanism dependent on nNOS, probably via increasing NO/cGMP production.
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Affiliation(s)
- K P Nunes
- Department of Biochemistry, Biological Science Institute, Federal University of Minas Gerais, Gerais, Belo Horizonte, Brazil.
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Chaim OM, Trevisan-Silva D, Chaves-Moreira D, Wille ACM, Ferrer VP, Matsubara FH, Mangili OC, da Silveira RB, Gremski LH, Gremski W, Senff-Ribeiro A, Veiga SS. Brown spider (Loxosceles genus) venom toxins: tools for biological purposes. Toxins (Basel) 2011; 3:309-44. [PMID: 22069711 PMCID: PMC3202818 DOI: 10.3390/toxins3030309] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 02/26/2011] [Accepted: 03/17/2011] [Indexed: 12/16/2022] Open
Abstract
Venomous animals use their venoms as tools for defense or predation. These venoms are complex mixtures, mainly enriched of proteic toxins or peptides with several, and different, biological activities. In general, spider venom is rich in biologically active molecules that are useful in experimental protocols for pharmacology, biochemistry, cell biology and immunology, as well as putative tools for biotechnology and industries. Spider venoms have recently garnered much attention from several research groups worldwide. Brown spider (Loxosceles genus) venom is enriched in low molecular mass proteins (5–40 kDa). Although their venom is produced in minute volumes (a few microliters), and contain only tens of micrograms of protein, the use of techniques based on molecular biology and proteomic analysis has afforded rational projects in the area and permitted the discovery and identification of a great number of novel toxins. The brown spider phospholipase-D family is undoubtedly the most investigated and characterized, although other important toxins, such as low molecular mass insecticidal peptides, metalloproteases and hyaluronidases have also been identified and featured in literature. The molecular pathways of the action of these toxins have been reported and brought new insights in the field of biotechnology. Herein, we shall see how recent reports describing discoveries in the area of brown spider venom have expanded biotechnological uses of molecules identified in these venoms, with special emphasis on the construction of a cDNA library for venom glands, transcriptome analysis, proteomic projects, recombinant expression of different proteic toxins, and finally structural descriptions based on crystallography of toxins.
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Affiliation(s)
- Olga Meiri Chaim
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
| | - Dilza Trevisan-Silva
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
| | - Daniele Chaves-Moreira
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
| | - Ana Carolina M. Wille
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
- Department of Structural, Molecular Biology and Genetics, State University of Ponta Grossa, CEP 84030-900 Ponta Grossa, Paraná, Brazil;
| | - Valéria Pereira Ferrer
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
| | - Fernando Hitomi Matsubara
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
| | | | - Rafael Bertoni da Silveira
- Department of Structural, Molecular Biology and Genetics, State University of Ponta Grossa, CEP 84030-900 Ponta Grossa, Paraná, Brazil;
| | - Luiza Helena Gremski
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
| | - Waldemiro Gremski
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
- Catholic University of Paraná, Health and Biological Sciences Institute, CEP 80215-901 Curitiba, Paraná, Brazil;
| | - Andrea Senff-Ribeiro
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
| | - Silvio Sanches Veiga
- Department of Cell Biology, Federal University of Paraná, CEP 81531-980 Curitiba, Paraná, Brazil; (O.M.C.); (D.T.-S); (D.C.-M); (A.C.M.W.); (V.P.F.); (F.H.M.); (L.H.G.); (A.S.-R)
- Author to whom correspondence should be addressed; ; Tel.: +55-41-33611776; Fax: +55-41-3266-2042
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Torres F, Silva C, Lanza L, Santos AV, Pimenta A, De Lima M, Diniz M. Functional expression of a recombinant toxin – rPnTx2-6 – active in erectile function in rat. Toxicon 2010; 56:1172-80. [DOI: 10.1016/j.toxicon.2010.04.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2009] [Revised: 03/24/2010] [Accepted: 04/19/2010] [Indexed: 10/19/2022]
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Nunes KP, Cordeiro MN, Richardson M, Borges MN, Diniz SOF, Cardoso VN, Tostes R, De Lima ME, Webb RC, Leite R. Nitric oxide-induced vasorelaxation in response to PnTx2-6 toxin from Phoneutria nigriventer spider in rat cavernosal tissue. J Sex Med 2010; 7:3879-88. [PMID: 20722794 DOI: 10.1111/j.1743-6109.2010.01978.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Priapism is one of several symptoms observed in accidental bites by the spider Phoneutria nigriventer. The venom of this spider is comprised of many toxins, and the majority has been shown to affect excitable ion channels, mainly sodium (Na(+) ) channels. It has been demonstrated that PnTx2-6, a peptide extracted from the venom of P. nigriventer, causes erection in anesthetized rats and mice. AIM We investigated the mechanism by which PnTx2-6 evokes relaxation in rat corpus cavernosum. MAIN OUTCOME MEASURES PnTx2-6 toxin potentiates nitric oxide (NO)-dependent cavernosal relaxation. METHODS Rat cavernosal strips were incubated with bretylium (3 × 10(-5) M) and contracted with phenylephrine (PE; 10(-5) M). Relaxation responses were evoked by electrical field stimulation (EFS) or sodium nitroprusside (SNP) before and after 4 minutes of incubation with PnTx2-6 (10(-8) M). The effect of PnTx2-6 on relaxation induced by EFS was also tested in the presence of atropine (10(-6) M), a muscarinic receptor antagonist, N-type Ca(2+) channel blockers (ω-conotoxin GVIA, 10(-6) M) and sildenafil (3 × 10(-8) M). Technetium99m radiolabeled PnTx2-6 subcutaneous injection was administrated in the penis. RESULTS Whereas relaxation induced by SNP was not affected by PnTx2-6, EFS-induced relaxation was significantly potentiated by this toxin as well as PnTx2-6 plus SNP. This potentiating effect was further increased by sildenafil, not altered by atropine, however was completely blocked by the N-type Ca(2+) channels. High concentrated levels of radiolabeled PnTx2-6 was specifically found in the cavernosum tissue, suggesting PnTx2-6 is an important toxin responsible for P. nigriventer spider accident-induced priapism. CONCLUSION We show that PnTx2-6 slows Na(+) channels inactivation in nitrergic neurons, allowing Ca(2+) influx to facilitate NO/cGMP signalling, which promotes increased NO production. In addition, this relaxation effect is independent of phosphodiesterase enzyme type 5 inhibition. Our data displays PnTx2-6 as possible pharmacological tool to study alternative treatments for erectile dysfunction.
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Affiliation(s)
- Kenia P Nunes
- Biological Science Institute, Belo Horizonte, MG, Brazil.
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Nickson CP, Currie BJ, Fenner PJ. Priapism and Irukandji syndrome. Ann Emerg Med 2010; 55:581-2. [PMID: 20494230 DOI: 10.1016/j.annemergmed.2010.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 12/08/2009] [Accepted: 01/06/2010] [Indexed: 10/19/2022]
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