Amelioration of retinal degeneration and proteolysis in acute ocular hypertensive rats by calpain inhibitor ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbo nyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester

T. Oka, R. D. Walkup, Y. Tamada, E. Nakajima, A. Tochigi, Thomas (Tom) Shearer, M. Azuma

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Background: Our recent study suggested involvement of calpain-induced proteolysis in retinal degeneration and dysfunction in acute ocular hypertensive rats. The purpose of the present study was to determine if an orally available form of calpain inhibitor, ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbo nyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester (SNJ-1945), ameliorated retinal degeneration induced by acute hypertension in rats. To help extrapolate the effect of SNJ-1945 from the rat model to the human glaucomatous patient, in vitro inhibition of calpain-induced proteolysis by SNJ-1945 in monkey and human retinal proteins was compared with proteolysis in rat proteins. Methods: Intraocular pressure (IOP) in rats was elevated to 110 mm Hg for 50 min. SNJ-1945 was administrated i.p. or orally before ocular hypertension. Retinal degeneration was evaluated by hematoxylin and eosin (H&E) staining and cell counting. Transcripts for calpains and calpastatin in rat, monkey, and human retinas were measured by quantitative RT-PCR. Calpain activities were determined by casein zymography. Soluble retinal proteins from rat, monkey, and humans were incubated with calcium to activate calpains, with or without SNJ-1945. Proteolysis of calpain substrate α-spectrin was analyzed by immunoblotting. Results: Elevated IOP caused retinal degeneration and proteolysis of α-spectrin. Both i.p. and oral administration of SNJ-1945 inhibited proteolysis of α-spectrin and ameliorated retinal degeneration. Transcript levels for calpain 1 and calpastatin were similar in rat, monkey, and human retinas. Calpain 2 transcript levels were higher in rats compared with monkey and human. Appreciable caseinolytic activities due to calpains were observed in monkey and human retinas. Incubation of retinal soluble proteins with calcium led to proteolysis of α-spectrin due to calpains in rat, monkey, and human samples. SNJ-1945 similarly inhibited proteolysis in all species. Conclusion: Our results suggested that orally available calpain inhibitor SNJ-1945 might be a possible candidate drug for testing in preventing progression of glaucomatous retinal degeneration.

Original languageEnglish (US)
Pages (from-to)2139-2145
Number of pages7
JournalNeuroscience
Volume141
Issue number4
DOIs
StatePublished - 2006

Fingerprint

Retinal Degeneration
Calpain
Charcoal
Proteolysis
Esters
Haplorhini
Spectrin
Retina
Intraocular Pressure
Proteins
calpain inhibitors
carbamic acid
Calcium
Ocular Hypertension
((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbonyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester
Hematoxylin
Eosine Yellowish-(YS)
Caseins
Immunoblotting
Oral Administration

Keywords

  • α-spectrin
  • calpain
  • calpain inhibitor SNJ-1945
  • calpastatin
  • glaucoma
  • retinal ganglion cell

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

@article{82b28aa83e864977990fe3eba00a1de5,
title = "Amelioration of retinal degeneration and proteolysis in acute ocular hypertensive rats by calpain inhibitor ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbo nyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester",
abstract = "Background: Our recent study suggested involvement of calpain-induced proteolysis in retinal degeneration and dysfunction in acute ocular hypertensive rats. The purpose of the present study was to determine if an orally available form of calpain inhibitor, ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbo nyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester (SNJ-1945), ameliorated retinal degeneration induced by acute hypertension in rats. To help extrapolate the effect of SNJ-1945 from the rat model to the human glaucomatous patient, in vitro inhibition of calpain-induced proteolysis by SNJ-1945 in monkey and human retinal proteins was compared with proteolysis in rat proteins. Methods: Intraocular pressure (IOP) in rats was elevated to 110 mm Hg for 50 min. SNJ-1945 was administrated i.p. or orally before ocular hypertension. Retinal degeneration was evaluated by hematoxylin and eosin (H&E) staining and cell counting. Transcripts for calpains and calpastatin in rat, monkey, and human retinas were measured by quantitative RT-PCR. Calpain activities were determined by casein zymography. Soluble retinal proteins from rat, monkey, and humans were incubated with calcium to activate calpains, with or without SNJ-1945. Proteolysis of calpain substrate α-spectrin was analyzed by immunoblotting. Results: Elevated IOP caused retinal degeneration and proteolysis of α-spectrin. Both i.p. and oral administration of SNJ-1945 inhibited proteolysis of α-spectrin and ameliorated retinal degeneration. Transcript levels for calpain 1 and calpastatin were similar in rat, monkey, and human retinas. Calpain 2 transcript levels were higher in rats compared with monkey and human. Appreciable caseinolytic activities due to calpains were observed in monkey and human retinas. Incubation of retinal soluble proteins with calcium led to proteolysis of α-spectrin due to calpains in rat, monkey, and human samples. SNJ-1945 similarly inhibited proteolysis in all species. Conclusion: Our results suggested that orally available calpain inhibitor SNJ-1945 might be a possible candidate drug for testing in preventing progression of glaucomatous retinal degeneration.",
keywords = "α-spectrin, calpain, calpain inhibitor SNJ-1945, calpastatin, glaucoma, retinal ganglion cell",
author = "T. Oka and Walkup, {R. D.} and Y. Tamada and E. Nakajima and A. Tochigi and Shearer, {Thomas (Tom)} and M. Azuma",
year = "2006",
doi = "10.1016/j.neuroscience.2006.05.060",
language = "English (US)",
volume = "141",
pages = "2139--2145",
journal = "Neuroscience",
issn = "0306-4522",
publisher = "Elsevier Limited",
number = "4",

}

TY - JOUR

T1 - Amelioration of retinal degeneration and proteolysis in acute ocular hypertensive rats by calpain inhibitor ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbo nyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester

AU - Oka, T.

AU - Walkup, R. D.

AU - Tamada, Y.

AU - Nakajima, E.

AU - Tochigi, A.

AU - Shearer, Thomas (Tom)

AU - Azuma, M.

PY - 2006

Y1 - 2006

N2 - Background: Our recent study suggested involvement of calpain-induced proteolysis in retinal degeneration and dysfunction in acute ocular hypertensive rats. The purpose of the present study was to determine if an orally available form of calpain inhibitor, ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbo nyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester (SNJ-1945), ameliorated retinal degeneration induced by acute hypertension in rats. To help extrapolate the effect of SNJ-1945 from the rat model to the human glaucomatous patient, in vitro inhibition of calpain-induced proteolysis by SNJ-1945 in monkey and human retinal proteins was compared with proteolysis in rat proteins. Methods: Intraocular pressure (IOP) in rats was elevated to 110 mm Hg for 50 min. SNJ-1945 was administrated i.p. or orally before ocular hypertension. Retinal degeneration was evaluated by hematoxylin and eosin (H&E) staining and cell counting. Transcripts for calpains and calpastatin in rat, monkey, and human retinas were measured by quantitative RT-PCR. Calpain activities were determined by casein zymography. Soluble retinal proteins from rat, monkey, and humans were incubated with calcium to activate calpains, with or without SNJ-1945. Proteolysis of calpain substrate α-spectrin was analyzed by immunoblotting. Results: Elevated IOP caused retinal degeneration and proteolysis of α-spectrin. Both i.p. and oral administration of SNJ-1945 inhibited proteolysis of α-spectrin and ameliorated retinal degeneration. Transcript levels for calpain 1 and calpastatin were similar in rat, monkey, and human retinas. Calpain 2 transcript levels were higher in rats compared with monkey and human. Appreciable caseinolytic activities due to calpains were observed in monkey and human retinas. Incubation of retinal soluble proteins with calcium led to proteolysis of α-spectrin due to calpains in rat, monkey, and human samples. SNJ-1945 similarly inhibited proteolysis in all species. Conclusion: Our results suggested that orally available calpain inhibitor SNJ-1945 might be a possible candidate drug for testing in preventing progression of glaucomatous retinal degeneration.

AB - Background: Our recent study suggested involvement of calpain-induced proteolysis in retinal degeneration and dysfunction in acute ocular hypertensive rats. The purpose of the present study was to determine if an orally available form of calpain inhibitor, ((1S)-1-((((1S)-1-benzyl-3-cyclopropylamino-2,3-di-oxopropyl)amino)carbo nyl)-3-methylbutyl)carbamic acid 5-methoxy-3-oxapentyl ester (SNJ-1945), ameliorated retinal degeneration induced by acute hypertension in rats. To help extrapolate the effect of SNJ-1945 from the rat model to the human glaucomatous patient, in vitro inhibition of calpain-induced proteolysis by SNJ-1945 in monkey and human retinal proteins was compared with proteolysis in rat proteins. Methods: Intraocular pressure (IOP) in rats was elevated to 110 mm Hg for 50 min. SNJ-1945 was administrated i.p. or orally before ocular hypertension. Retinal degeneration was evaluated by hematoxylin and eosin (H&E) staining and cell counting. Transcripts for calpains and calpastatin in rat, monkey, and human retinas were measured by quantitative RT-PCR. Calpain activities were determined by casein zymography. Soluble retinal proteins from rat, monkey, and humans were incubated with calcium to activate calpains, with or without SNJ-1945. Proteolysis of calpain substrate α-spectrin was analyzed by immunoblotting. Results: Elevated IOP caused retinal degeneration and proteolysis of α-spectrin. Both i.p. and oral administration of SNJ-1945 inhibited proteolysis of α-spectrin and ameliorated retinal degeneration. Transcript levels for calpain 1 and calpastatin were similar in rat, monkey, and human retinas. Calpain 2 transcript levels were higher in rats compared with monkey and human. Appreciable caseinolytic activities due to calpains were observed in monkey and human retinas. Incubation of retinal soluble proteins with calcium led to proteolysis of α-spectrin due to calpains in rat, monkey, and human samples. SNJ-1945 similarly inhibited proteolysis in all species. Conclusion: Our results suggested that orally available calpain inhibitor SNJ-1945 might be a possible candidate drug for testing in preventing progression of glaucomatous retinal degeneration.

KW - α-spectrin

KW - calpain

KW - calpain inhibitor SNJ-1945

KW - calpastatin

KW - glaucoma

KW - retinal ganglion cell

UR - http://www.scopus.com/inward/record.url?scp=33747357512&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33747357512&partnerID=8YFLogxK

U2 - 10.1016/j.neuroscience.2006.05.060

DO - 10.1016/j.neuroscience.2006.05.060

M3 - Article

VL - 141

SP - 2139

EP - 2145

JO - Neuroscience

JF - Neuroscience

SN - 0306-4522

IS - 4

ER -