Effects of TAK-639, a novel topical C-type natriuretic peptide analog, on intraocular pressure and aqueous humor dynamics in mice

J. Cameron Millar, Anneli Savinainen, Serene Josiah, Iok Hou Pang

Research output: Contribution to journalArticle

Abstract

Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness, and individuals with ocular hypertension are at risk to develop POAG. Currently, the only modifiable risk factor for glaucoma progression is lowering of intraocular pressure (IOP). A novel mechanism for lowering IOP involves activation of the type B natriuretic peptide receptor (NPR-B), the naturally occurring agonist of which is C-type natriuretic peptide (CNP). Being a cyclic peptide of 22 amino acids, CNP does not readily penetrate the cornea and its ocular hypotensive effect requires intraocular injection. TAK-639 is a synthetic, cornea-permeable, 9-amino acid CNP analog has been studied for the treatment of ocular hypertension and POAG. We assessed TAK-639 in a receptor binding profile and the effects of TAK-639 on NPR-B-mediated cyclic GMP production in cultured transformed human trabecular meshwork (TM) cells (GTM-3). We also evaluated the effects of topical ocular administration of TAK-639 on mouse IOP and aqueous humor dynamics. Among 89 non-natriuretic peptide receptors, transporters, and channels evaluated, TAK-639 at 10 μM displaced ligand binding by more than 50% to only two receptors: the type 2 angiotensin receptor (IC50 = 8.2 μM) and the cholecystokinin A receptor (IC50 = 25.8 μM). In vitro, TAK-639 selectively activates NPR-B (EC50 = 61 ± 11 nM; GTM-3 cells) relative to NPR-A (EC50 = 2179 ± 670 nM; 293T cells). In vivo, TAK-639 lowered mouse IOP by three mechanisms: increase in aqueous humor outflow facility (C), reduction in the aqueous humor formation rate (Fin), and reduction in episcleral venous pressure (Pe). The maximum mean IOP decreases from baseline were −12.1%, −21.0%, and −36.1% for 0.1%, 0.3%, and 0.6% doses of TAK-639, respectively. Maximum IOP-lowering effect was seen at 2 h, and the duration of action was >6 h. With TAK-639 0.6%, at 2 h post-dose, aqueous outflow facility (C) increased by 155.8%, Fin decreased by 41.0%, the uveoscleral outflow rate (Fu) decreased by 52.6%, and Pe decreased by 31.5% (all p < 0.05). No ocular adverse effects were observed. TAK-639 is an efficacious IOP-lowering agent, with a unique combination of mechanisms of action on both aqueous formation and aqueous outflow facility. Further study of this mechanism of treatment may optimize pharmacologic outcomes and provide disease management in patients with POAG and ocular hypertension.

Original languageEnglish
Article number107763
JournalExperimental eye research
Volume188
DOIs
StatePublished - Nov 2019

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C-Type Natriuretic Peptide
Aqueous Humor
Intraocular Pressure
Ocular Hypertension
Cornea
Inhibitory Concentration 50
Ophthalmic Administration
Cholecystokinin A Receptor
Angiotensin Type 2 Receptor
Intraocular Injections
Trabecular Meshwork
Amino Acids
Topical Administration
Cyclic Peptides
Venous Pressure
Peptide Receptors
HEK293 Cells
Brain Natriuretic Peptide
Cyclic GMP
Blindness

Keywords

  • Aqueous humor
  • C-type natriuretic peptide
  • Intraocular pressure
  • Open-angle glaucoma
  • Trabecular meshwork

Cite this

@article{7dbdcbe9b3b34bcc93b81481a433a039,
title = "Effects of TAK-639, a novel topical C-type natriuretic peptide analog, on intraocular pressure and aqueous humor dynamics in mice",
abstract = "Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness, and individuals with ocular hypertension are at risk to develop POAG. Currently, the only modifiable risk factor for glaucoma progression is lowering of intraocular pressure (IOP). A novel mechanism for lowering IOP involves activation of the type B natriuretic peptide receptor (NPR-B), the naturally occurring agonist of which is C-type natriuretic peptide (CNP). Being a cyclic peptide of 22 amino acids, CNP does not readily penetrate the cornea and its ocular hypotensive effect requires intraocular injection. TAK-639 is a synthetic, cornea-permeable, 9-amino acid CNP analog has been studied for the treatment of ocular hypertension and POAG. We assessed TAK-639 in a receptor binding profile and the effects of TAK-639 on NPR-B-mediated cyclic GMP production in cultured transformed human trabecular meshwork (TM) cells (GTM-3). We also evaluated the effects of topical ocular administration of TAK-639 on mouse IOP and aqueous humor dynamics. Among 89 non-natriuretic peptide receptors, transporters, and channels evaluated, TAK-639 at 10 μM displaced ligand binding by more than 50{\%} to only two receptors: the type 2 angiotensin receptor (IC50 = 8.2 μM) and the cholecystokinin A receptor (IC50 = 25.8 μM). In vitro, TAK-639 selectively activates NPR-B (EC50 = 61 ± 11 nM; GTM-3 cells) relative to NPR-A (EC50 = 2179 ± 670 nM; 293T cells). In vivo, TAK-639 lowered mouse IOP by three mechanisms: increase in aqueous humor outflow facility (C), reduction in the aqueous humor formation rate (Fin), and reduction in episcleral venous pressure (Pe). The maximum mean IOP decreases from baseline were −12.1{\%}, −21.0{\%}, and −36.1{\%} for 0.1{\%}, 0.3{\%}, and 0.6{\%} doses of TAK-639, respectively. Maximum IOP-lowering effect was seen at 2 h, and the duration of action was >6 h. With TAK-639 0.6{\%}, at 2 h post-dose, aqueous outflow facility (C) increased by 155.8{\%}, Fin decreased by 41.0{\%}, the uveoscleral outflow rate (Fu) decreased by 52.6{\%}, and Pe decreased by 31.5{\%} (all p < 0.05). No ocular adverse effects were observed. TAK-639 is an efficacious IOP-lowering agent, with a unique combination of mechanisms of action on both aqueous formation and aqueous outflow facility. Further study of this mechanism of treatment may optimize pharmacologic outcomes and provide disease management in patients with POAG and ocular hypertension.",
keywords = "Aqueous humor, C-type natriuretic peptide, Intraocular pressure, Open-angle glaucoma, Trabecular meshwork",
author = "Millar, {J. Cameron} and Anneli Savinainen and Serene Josiah and Pang, {Iok Hou}",
year = "2019",
month = "11",
doi = "10.1016/j.exer.2019.107763",
language = "English",
volume = "188",
journal = "Experimental Eye Research",
issn = "0014-4835",
publisher = "Academic Press Inc.",

}

TY - JOUR

T1 - Effects of TAK-639, a novel topical C-type natriuretic peptide analog, on intraocular pressure and aqueous humor dynamics in mice

AU - Millar, J. Cameron

AU - Savinainen, Anneli

AU - Josiah, Serene

AU - Pang, Iok Hou

PY - 2019/11

Y1 - 2019/11

N2 - Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness, and individuals with ocular hypertension are at risk to develop POAG. Currently, the only modifiable risk factor for glaucoma progression is lowering of intraocular pressure (IOP). A novel mechanism for lowering IOP involves activation of the type B natriuretic peptide receptor (NPR-B), the naturally occurring agonist of which is C-type natriuretic peptide (CNP). Being a cyclic peptide of 22 amino acids, CNP does not readily penetrate the cornea and its ocular hypotensive effect requires intraocular injection. TAK-639 is a synthetic, cornea-permeable, 9-amino acid CNP analog has been studied for the treatment of ocular hypertension and POAG. We assessed TAK-639 in a receptor binding profile and the effects of TAK-639 on NPR-B-mediated cyclic GMP production in cultured transformed human trabecular meshwork (TM) cells (GTM-3). We also evaluated the effects of topical ocular administration of TAK-639 on mouse IOP and aqueous humor dynamics. Among 89 non-natriuretic peptide receptors, transporters, and channels evaluated, TAK-639 at 10 μM displaced ligand binding by more than 50% to only two receptors: the type 2 angiotensin receptor (IC50 = 8.2 μM) and the cholecystokinin A receptor (IC50 = 25.8 μM). In vitro, TAK-639 selectively activates NPR-B (EC50 = 61 ± 11 nM; GTM-3 cells) relative to NPR-A (EC50 = 2179 ± 670 nM; 293T cells). In vivo, TAK-639 lowered mouse IOP by three mechanisms: increase in aqueous humor outflow facility (C), reduction in the aqueous humor formation rate (Fin), and reduction in episcleral venous pressure (Pe). The maximum mean IOP decreases from baseline were −12.1%, −21.0%, and −36.1% for 0.1%, 0.3%, and 0.6% doses of TAK-639, respectively. Maximum IOP-lowering effect was seen at 2 h, and the duration of action was >6 h. With TAK-639 0.6%, at 2 h post-dose, aqueous outflow facility (C) increased by 155.8%, Fin decreased by 41.0%, the uveoscleral outflow rate (Fu) decreased by 52.6%, and Pe decreased by 31.5% (all p < 0.05). No ocular adverse effects were observed. TAK-639 is an efficacious IOP-lowering agent, with a unique combination of mechanisms of action on both aqueous formation and aqueous outflow facility. Further study of this mechanism of treatment may optimize pharmacologic outcomes and provide disease management in patients with POAG and ocular hypertension.

AB - Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness, and individuals with ocular hypertension are at risk to develop POAG. Currently, the only modifiable risk factor for glaucoma progression is lowering of intraocular pressure (IOP). A novel mechanism for lowering IOP involves activation of the type B natriuretic peptide receptor (NPR-B), the naturally occurring agonist of which is C-type natriuretic peptide (CNP). Being a cyclic peptide of 22 amino acids, CNP does not readily penetrate the cornea and its ocular hypotensive effect requires intraocular injection. TAK-639 is a synthetic, cornea-permeable, 9-amino acid CNP analog has been studied for the treatment of ocular hypertension and POAG. We assessed TAK-639 in a receptor binding profile and the effects of TAK-639 on NPR-B-mediated cyclic GMP production in cultured transformed human trabecular meshwork (TM) cells (GTM-3). We also evaluated the effects of topical ocular administration of TAK-639 on mouse IOP and aqueous humor dynamics. Among 89 non-natriuretic peptide receptors, transporters, and channels evaluated, TAK-639 at 10 μM displaced ligand binding by more than 50% to only two receptors: the type 2 angiotensin receptor (IC50 = 8.2 μM) and the cholecystokinin A receptor (IC50 = 25.8 μM). In vitro, TAK-639 selectively activates NPR-B (EC50 = 61 ± 11 nM; GTM-3 cells) relative to NPR-A (EC50 = 2179 ± 670 nM; 293T cells). In vivo, TAK-639 lowered mouse IOP by three mechanisms: increase in aqueous humor outflow facility (C), reduction in the aqueous humor formation rate (Fin), and reduction in episcleral venous pressure (Pe). The maximum mean IOP decreases from baseline were −12.1%, −21.0%, and −36.1% for 0.1%, 0.3%, and 0.6% doses of TAK-639, respectively. Maximum IOP-lowering effect was seen at 2 h, and the duration of action was >6 h. With TAK-639 0.6%, at 2 h post-dose, aqueous outflow facility (C) increased by 155.8%, Fin decreased by 41.0%, the uveoscleral outflow rate (Fu) decreased by 52.6%, and Pe decreased by 31.5% (all p < 0.05). No ocular adverse effects were observed. TAK-639 is an efficacious IOP-lowering agent, with a unique combination of mechanisms of action on both aqueous formation and aqueous outflow facility. Further study of this mechanism of treatment may optimize pharmacologic outcomes and provide disease management in patients with POAG and ocular hypertension.

KW - Aqueous humor

KW - C-type natriuretic peptide

KW - Intraocular pressure

KW - Open-angle glaucoma

KW - Trabecular meshwork

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