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Díaz-Peña LF, Daniela TO, Aguilar MB, Luis E, Lazcano-Pérez F, Arreguín-Espinosa R, Hernandez-Cruz A, Ibarra-Alvarado C, García-Arredondo A. A subfraction obtained from the venom of the tarantula Poecilotheria regalis contains inhibitor cystine knot peptides and induces relaxation of rat aorta by inhibiting L-type voltage-gated calcium channels. Toxicon X 2023; 18:100151. [PMID: 36873112 DOI: 10.1016/j.toxcx.2023.100151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 02/19/2023] Open
Abstract
Venoms from tarantulas contain low molecular weight vasodilatory compounds whose biological action is conceived as part of the envenomation strategy due to its propagative effects. However, some properties of venom-induced vasodilation do not match those described by such compounds, suggesting that other toxins may cooperate with these ones to produce the observed biological effect. Owing to the distribution and function of voltage-gated ion channels in blood vessels, disulfide-rich peptides isolated from venoms of tarantulas could be conceived into potential vasodilatory compounds. However, only two peptides isolated from spider venoms have been investigated so far. This study describes for the first time a subfraction containing inhibitor cystine knot peptides, PrFr-I, obtained from the venom of the tarantula Poecilotheria regalis. This subfraction induced sustained vasodilation in rat aortic rings independent of vascular endothelium and endothelial ion channels. Furthermore, PrFr-I decreased calcium-induced contraction of rat aortic segments and reduced extracellular calcium influx to chromaffin cells by the blockade of L-type voltage-gated calcium channels. This mechanism was unrelated to the activation of potassium channels from vascular smooth muscle, since vasodilation was not affected in the presence of TEA, and PrFr-I did not modify the conductance of the voltage-gated potassium channel Kv10.1. This work proposes a new envenomating function of peptides from venoms of tarantulas, and establishes a new mechanism for venom-induced vasodilation.
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Key Words
- ACh, acetylcholine
- ADP, adenosine diphosphate
- Cav, voltage-gated calcium channel
- DMEM, Dulbecco's modified eagle's medium
- DRP, disulfide-rich peptide
- EC50, half maximal effective concentration
- Emax, maximum effect
- FBS, fetal bovine serum
- HPLC, high-performance liquid chromatography
- ICK peptide
- ICK, inhibitor cystine knot
- IKCa, intermediate conductance calcium-activated potassium channel
- Kv, voltage-gated potassium channel
- L-type calcium voltage-gated calcium
- LC-MS/MS, liquid chromatography-tandem mass spectrometer
- MALDI, matrix-assisted desorption ionization
- Nav, voltage-gated sodium channel
- Phe, phenylephrine
- Poecilotheria regalis, venom
- RP, reverse phase
- Rat aorta
- SEM, standard error of the mean
- SKCa, small conductance calcium-activated potassium channel
- SNP, sodium nitroprusside
- TEA, tetraethylammonium
- TOF, time of flight
- TRP, transient receptor potential
- Vasodilation
- Vh, holding-voltage
- endothelium-intact (E+), endothelium-denuded (E−)
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Romero Caimi G, Gorzalczany S, Bonazzola P, Deza Z, Rosón MI, Alvarez L, Castilla R. Angiotensin II type 1 receptor is involved in hypertension and vascular alterations caused by environmental toxicant hexachlorobenzene. Toxicol Rep 2021; 8:1599-1606. [PMID: 34522623 PMCID: PMC8424126 DOI: 10.1016/j.toxrep.2021.08.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/04/2021] [Accepted: 08/28/2021] [Indexed: 11/30/2022] Open
Abstract
Environmental hexachlorobenzene (HCB) increases blood pressure (BP) in female rats, causing alterations in arterial structure and function. Here we study the role of Angiotensin II receptor type 1 (AT1) in HCB-induced hypertension through the use of AT1 antagonist losartan. HCB-treated male rats showed a 22.7% increase in BP which was prevented by losartan. Losartan blocked HCB-induced changes in arterial morphology (decreased aorta cell number and increased wall thickness). Losartan also prevented HCB-induced alterations in artery relaxation by acetylcholine and nitroprusside but not the reduction in the maximum contraction by phenylephrine. Losartan rescued arterial molecular alterations caused by HCB (i.e. an increase in TGF-β1 and AT1 expression and a decrease in eNOS expression and nitrite levels) and reduced hydrogen sulfide plasma concentration. In conclusion: in this work we demonstrate that AT1 activity is involved in HCB effects on the vascular system leading to hypertension.
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Key Words
- AT1
- AT1, angiotensin II receptor type 1
- Ach, acetylcholine
- AhR, aryl hydrocarbon receptor
- Ang II, angiotensin II
- Aorta
- BP, systolic blood pressure
- H&E, hematoxylin and eosin
- HCB, hexachlorobenzene
- Hexachlorobenzene
- Hypertension
- Losartan
- NO, nitric oxide
- PCBs, polychlorinated biphenyls
- POPs, persistent organic pollutant
- Phe, phenylephrine
- SNP, nitroprusside
- TGF-β1, Transforming Growth Factor-β1
- eNOS, endothelial nitric oxide synthase
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Affiliation(s)
- Giselle Romero Caimi
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Paraguay 2155, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina
| | - Susana Gorzalczany
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Farmacología, Cátedra de Farmacología, Junín 956, C1113AAD, Ciudad Autónoma de Buenos Aires, Argentina
| | - Patricia Bonazzola
- Universidad de Buenos Aires, CONICET, Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), Marcelo T. de Alvear 2270, C1122AAJ, Ciudad Autónoma de Buenos Aires, Argentina
| | - Zahira Deza
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Paraguay 2155, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina
| | - María Inés Rosón
- Universidad de Buenos Aires, CONICET, Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), Marcelo T. de Alvear 2270, C1122AAJ, Ciudad Autónoma de Buenos Aires, Argentina
| | - Laura Alvarez
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Laboratorio de Efectos Biológicos de Contaminantes Ambientales, Paraguay 2155, C1121ABG Ciudad Autónoma de Buenos Aires, Argentina
| | - Rocío Castilla
- Universidad de Buenos Aires, CONICET, Instituto Alberto C. Taquini de Investigaciones en Medicina Traslacional (IATIMET), Marcelo T. de Alvear 2270, C1122AAJ, Ciudad Autónoma de Buenos Aires, Argentina
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