Cytotoxicity and vitreous stability of chemically modified connexin43 mimetic peptides for the treatment of optic neuropathy

Chen, Ying-Shan, Toth, Istvan, Danesh-Meyer, Helen V., Green, Colin R. and Rupenthal, Ilva D. (2013) Cytotoxicity and vitreous stability of chemically modified connexin43 mimetic peptides for the treatment of optic neuropathy. Journal of Pharmaceutical Sciences, 102 7: 2322-2331. doi:10.1002/jps.23617


Author Chen, Ying-Shan
Toth, Istvan
Danesh-Meyer, Helen V.
Green, Colin R.
Rupenthal, Ilva D.
Title Cytotoxicity and vitreous stability of chemically modified connexin43 mimetic peptides for the treatment of optic neuropathy
Journal name Journal of Pharmaceutical Sciences   Check publisher's open access policy
ISSN 0022-3549
1520-6017
Publication date 2013-06-01
Sub-type Article (original research)
DOI 10.1002/jps.23617
Open Access Status Not yet assessed
Volume 102
Issue 7
Start page 2322
End page 2331
Total pages 10
Place of publication Hoboken, NJ, United States
Publisher John Wiley & Sons
Language eng
Subject 3003 Pharmaceutical Science
Abstract Optic neuropathy is associated with retinal ganglion cell (RGC) loss leading to optic nerve damage and visual impairment. Unregulated connexin (Cx) hemichannel opening plays a role in RGC loss. Thus, inhibition via Cx43-specific mimetic peptides (MP) may prevent further cell death. However, the highly hydrophilic character and poor stability of native peptides prevent their efficient delivery across biological membranes. The present study aimed to improve the stability of Cx43 MP by conjugation to C-lipoamino acid (C-Laa) or sugar groups. Unmodified and modified Cx43 MP were synthesized using solid-phase peptide synthesis. Their functionality was assessed by propidium iodide (PI) uptake into NT2 cells, a human testicular carcinoma progenitor cell line able to differentiate into astrocytes, whereas the stability in ocular vitreous was measured by reversed-phase high-performance liquid chromatography. PI uptake studies showed inhibition of hemichannel opening for unmodified and modified Cx43 MP. Stability measurements revealed improved stability of modified Cx43 MP, with two Laa groups increasing the peptide half-life in bovine vitreous more than twofold. Conjugation to C-Laa or sugar did not affect the functionality of Cx43 MP, but addition of two C-Laa groups significantly improved peptide stability. Laa-modifications may therefore offer improved stability and retinal delivery of peptides in vivo.
Formatted abstract
Optic neuropathy is associated with retinal ganglion cell (RGC) loss leading to optic nerve damage and visual impairment. Unregulated connexin (Cx) hemichannel opening plays a role in RGC loss. Thus, inhibition via Cx43-specific mimetic peptides (MP) may prevent further cell death. However, the highly hydrophilic character and poor stability of native peptides prevent their efficient delivery across biological membranes. The present study aimed to improve the stability of Cx43 MP by conjugation to C12-lipoamino acid (C12-Laa) or sugar groups. Unmodified and modified Cx43 MP were synthesized using solid-phase peptide synthesis. Their functionality was assessed by propidium iodide (PI) uptake into NT2 cells, a human testicular carcinoma progenitor cell line able to differentiate into astrocytes, whereas the stability in ocular vitreous was measured by reversed-phase high-performance liquid chromatography. PI uptake studies showed inhibition of hemichannel opening for unmodified and modified Cx43 MP. Stability measurements revealed improved stability of modified Cx43 MP, with two Laa groups increasing the peptide half-life in bovine vitreous more than twofold. Conjugation to C12-Laa or sugar did not affect the functionality of Cx43 MP, but addition of two C12-Laa groups significantly improved peptide stability. Laa-modifications may therefore offer improved stability and retinal delivery of peptides in vivo.
Keyword Cell culture
Conjugation
Connexin
HPLC
Intravitreal delivery
Lipoamino acid
Mimetic peptide
Peptide delivery
Solid-phase peptide synthesis
Stability
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2014 Collection
School of Chemistry and Molecular Biosciences
School of Pharmacy Publications
 
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Citation counts: TR Web of Science Citation Count  Cited 12 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 13 times in Scopus Article | Citations
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Created: Sat, 25 May 2013, 00:38:23 EST by Mrs Louise Nimwegen on behalf of School of Chemistry & Molecular Biosciences