Epac2 Elevation Reverses Inhibition by Chondroitin Sulfate Proteoglycans In Vitro and Transforms Postlesion Inhibitory Environment to Promote Axonal Outgrowth in an Ex Vivo Model of Spinal Cord Injury

Alba Guijarro Belmar, Mindaugas Viskontas, Yuting Wei, Xuenong Bo, Derryck Shewan, Wenlong Huang (Corresponding Author)

Research output: Contribution to journalArticle

Abstract

Millions of patients suffer from debilitating spinal cord injury (SCI) without effective treatments. Elevating cAMP promotes CNS neuron growth in the presence of growth-inhibiting molecules. cAMP's effects on neuron growth is partly mediated by Epac, comprising Epac1 and Epac2 — the latter predominantly expresses in postnatal neural tissue. Here, we hypothesized that Epac2 activation would enhance axonal outgrowth after SCI. Using in vitro assays, we demonstrated for the first time that Epac2 activation using a specific soluble agonist (S-220) significantly enhanced neurite outgrowth of postnatal rat cortical neurons and markedly overcame the inhibition by chondroitin sulphate proteoglycans and mature astrocytes on neuron growth. We further investigated the novel potential of Epac2 activation in promoting axonal outgrowth by an ex vivo rat model of SCI mimicking post-SCI environment in vivo and by delivering S-220 via a self-assembling Fmoc-based hydrogel that has suitable properties for SCI repair. We demonstrated that S-220 significantly enhanced axonal outgrowth across the lesion gaps in the organotypic spinal cord slices, compared with controls. Furthermore, we elucidated for the first time that Epac2 activation profoundly modulated the lesion environment by reducing astrocyte/microglial activation and transforming astrocytes into elongated morphology that guided outgrowing axons. Finally, we showed that S-220, when delivered by the gel at 3 weeks after contusion SCI in male adult rats, resulted in significantly better locomotor performance for up to 4 weeks post-treatment. Our data demonstrate a promising therapeutic potential of S-220 in SCI, via beneficial effects on neurons and glia post-injury to facilitate axonal outgrowth.
Original languageEnglish
Pages (from-to)8330-8346
Number of pages17
JournalJournal of Neuroscience
Volume39
Issue number42
Early online date13 Aug 2019
DOIs
Publication statusPublished - 16 Oct 2019

Fingerprint

Chondroitin Sulfate Proteoglycans
Spinal Cord Injuries
Neurons
Astrocytes
Growth
Spinal Cord Regeneration
Contusions
Hydrogel
In Vitro Techniques
Neuroglia
Axons
Spinal Cord
Therapeutics
Gels
Wounds and Injuries

Keywords

  • astrocyte
  • axonal growth
  • cAMP
  • Epac2
  • organotypic
  • spinal cord injury
  • axonal regrowth
  • FUNCTIONAL RECOVERY
  • DRUG-DELIVERY
  • PROTEIN-KINASE
  • CST AXONS
  • PTEN DELETION
  • CYCLIC-AMP
  • NEURITE OUTGROWTH
  • GROWTH
  • CONDITIONAL GENETIC DELETION
  • CAMP

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

@article{b1ed56849b8843d4a2a6922c4ebcd45c,
title = "Epac2 Elevation Reverses Inhibition by Chondroitin Sulfate Proteoglycans In Vitro and Transforms Postlesion Inhibitory Environment to Promote Axonal Outgrowth in an Ex Vivo Model of Spinal Cord Injury",
abstract = "Millions of patients suffer from debilitating spinal cord injury (SCI) without effective treatments. Elevating cAMP promotes CNS neuron growth in the presence of growth-inhibiting molecules. cAMP's effects on neuron growth is partly mediated by Epac, comprising Epac1 and Epac2 — the latter predominantly expresses in postnatal neural tissue. Here, we hypothesized that Epac2 activation would enhance axonal outgrowth after SCI. Using in vitro assays, we demonstrated for the first time that Epac2 activation using a specific soluble agonist (S-220) significantly enhanced neurite outgrowth of postnatal rat cortical neurons and markedly overcame the inhibition by chondroitin sulphate proteoglycans and mature astrocytes on neuron growth. We further investigated the novel potential of Epac2 activation in promoting axonal outgrowth by an ex vivo rat model of SCI mimicking post-SCI environment in vivo and by delivering S-220 via a self-assembling Fmoc-based hydrogel that has suitable properties for SCI repair. We demonstrated that S-220 significantly enhanced axonal outgrowth across the lesion gaps in the organotypic spinal cord slices, compared with controls. Furthermore, we elucidated for the first time that Epac2 activation profoundly modulated the lesion environment by reducing astrocyte/microglial activation and transforming astrocytes into elongated morphology that guided outgrowing axons. Finally, we showed that S-220, when delivered by the gel at 3 weeks after contusion SCI in male adult rats, resulted in significantly better locomotor performance for up to 4 weeks post-treatment. Our data demonstrate a promising therapeutic potential of S-220 in SCI, via beneficial effects on neurons and glia post-injury to facilitate axonal outgrowth.",
keywords = "astrocyte, axonal growth, cAMP, Epac2, organotypic, spinal cord injury, axonal regrowth, FUNCTIONAL RECOVERY, DRUG-DELIVERY, PROTEIN-KINASE, CST AXONS, PTEN DELETION, CYCLIC-AMP, NEURITE OUTGROWTH, GROWTH, CONDITIONAL GENETIC DELETION, CAMP",
author = "{Guijarro Belmar}, Alba and Mindaugas Viskontas and Yuting Wei and Xuenong Bo and Derryck Shewan and Wenlong Huang",
note = "This work was supported by the International Spinal Research Trust, Scottish Rugby Union and RS McDonald Charitable Trust. We thank Professor Divya Chari for training with the ex vivo model. We also thank Dr Amer Syed, Ms Elena Moratal-Torres, Mr James W. Thomson, Ms Victoria Torsteinsb{\o} and Dr Marieta Georgieva for their assistance with rheology and in vitro experiments.",
year = "2019",
month = "10",
day = "16",
doi = "10.1523/JNEUROSCI.0374-19.2019",
language = "English",
volume = "39",
pages = "8330--8346",
journal = "Journal of Neuroscience",
issn = "0270-6474",
publisher = "Society for Neuroscience",
number = "42",

}

TY - JOUR

T1 - Epac2 Elevation Reverses Inhibition by Chondroitin Sulfate Proteoglycans In Vitro and Transforms Postlesion Inhibitory Environment to Promote Axonal Outgrowth in an Ex Vivo Model of Spinal Cord Injury

AU - Guijarro Belmar, Alba

AU - Viskontas, Mindaugas

AU - Wei, Yuting

AU - Bo, Xuenong

AU - Shewan, Derryck

AU - Huang, Wenlong

N1 - This work was supported by the International Spinal Research Trust, Scottish Rugby Union and RS McDonald Charitable Trust. We thank Professor Divya Chari for training with the ex vivo model. We also thank Dr Amer Syed, Ms Elena Moratal-Torres, Mr James W. Thomson, Ms Victoria Torsteinsbø and Dr Marieta Georgieva for their assistance with rheology and in vitro experiments.

PY - 2019/10/16

Y1 - 2019/10/16

N2 - Millions of patients suffer from debilitating spinal cord injury (SCI) without effective treatments. Elevating cAMP promotes CNS neuron growth in the presence of growth-inhibiting molecules. cAMP's effects on neuron growth is partly mediated by Epac, comprising Epac1 and Epac2 — the latter predominantly expresses in postnatal neural tissue. Here, we hypothesized that Epac2 activation would enhance axonal outgrowth after SCI. Using in vitro assays, we demonstrated for the first time that Epac2 activation using a specific soluble agonist (S-220) significantly enhanced neurite outgrowth of postnatal rat cortical neurons and markedly overcame the inhibition by chondroitin sulphate proteoglycans and mature astrocytes on neuron growth. We further investigated the novel potential of Epac2 activation in promoting axonal outgrowth by an ex vivo rat model of SCI mimicking post-SCI environment in vivo and by delivering S-220 via a self-assembling Fmoc-based hydrogel that has suitable properties for SCI repair. We demonstrated that S-220 significantly enhanced axonal outgrowth across the lesion gaps in the organotypic spinal cord slices, compared with controls. Furthermore, we elucidated for the first time that Epac2 activation profoundly modulated the lesion environment by reducing astrocyte/microglial activation and transforming astrocytes into elongated morphology that guided outgrowing axons. Finally, we showed that S-220, when delivered by the gel at 3 weeks after contusion SCI in male adult rats, resulted in significantly better locomotor performance for up to 4 weeks post-treatment. Our data demonstrate a promising therapeutic potential of S-220 in SCI, via beneficial effects on neurons and glia post-injury to facilitate axonal outgrowth.

AB - Millions of patients suffer from debilitating spinal cord injury (SCI) without effective treatments. Elevating cAMP promotes CNS neuron growth in the presence of growth-inhibiting molecules. cAMP's effects on neuron growth is partly mediated by Epac, comprising Epac1 and Epac2 — the latter predominantly expresses in postnatal neural tissue. Here, we hypothesized that Epac2 activation would enhance axonal outgrowth after SCI. Using in vitro assays, we demonstrated for the first time that Epac2 activation using a specific soluble agonist (S-220) significantly enhanced neurite outgrowth of postnatal rat cortical neurons and markedly overcame the inhibition by chondroitin sulphate proteoglycans and mature astrocytes on neuron growth. We further investigated the novel potential of Epac2 activation in promoting axonal outgrowth by an ex vivo rat model of SCI mimicking post-SCI environment in vivo and by delivering S-220 via a self-assembling Fmoc-based hydrogel that has suitable properties for SCI repair. We demonstrated that S-220 significantly enhanced axonal outgrowth across the lesion gaps in the organotypic spinal cord slices, compared with controls. Furthermore, we elucidated for the first time that Epac2 activation profoundly modulated the lesion environment by reducing astrocyte/microglial activation and transforming astrocytes into elongated morphology that guided outgrowing axons. Finally, we showed that S-220, when delivered by the gel at 3 weeks after contusion SCI in male adult rats, resulted in significantly better locomotor performance for up to 4 weeks post-treatment. Our data demonstrate a promising therapeutic potential of S-220 in SCI, via beneficial effects on neurons and glia post-injury to facilitate axonal outgrowth.

KW - astrocyte

KW - axonal growth

KW - cAMP

KW - Epac2

KW - organotypic

KW - spinal cord injury

KW - axonal regrowth

KW - FUNCTIONAL RECOVERY

KW - DRUG-DELIVERY

KW - PROTEIN-KINASE

KW - CST AXONS

KW - PTEN DELETION

KW - CYCLIC-AMP

KW - NEURITE OUTGROWTH

KW - GROWTH

KW - CONDITIONAL GENETIC DELETION

KW - CAMP

UR - http://www.jneurosci.org/lookup/doi/10.1523/JNEUROSCI.0374-19.2019

UR - http://www.mendeley.com/research/epac2-elevation-reverses-inhibition-chondroitin-sulfate-proteoglycans-vitro-transforms-postlesion-in

UR - http://www.scopus.com/inward/record.url?scp=85073488275&partnerID=8YFLogxK

U2 - 10.1523/JNEUROSCI.0374-19.2019

DO - 10.1523/JNEUROSCI.0374-19.2019

M3 - Article

C2 - 31409666

VL - 39

SP - 8330

EP - 8346

JO - Journal of Neuroscience

JF - Journal of Neuroscience

SN - 0270-6474

IS - 42

ER -