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Direct optic nerve sheath (DONS) application of Schwann cells prolongs retinal ganglion cell survival in vivo.

Guo L, Davis B, Nizari S, Normando EM, Shi H, Galvao J, Turner L, Shi J, Clements M, Parrinello S, Cordeiro MF - Cell Death Dis (2014)

Bottom Line: Although both SC/DONS and SC/IVT altered the temporal course of RGC degeneration in pONT, SC/DONS resulted in delayed but long-lasting effects on RGC protection, compared with SC/IVT treatment.SC/DONS was found to significantly reduce RGC apoptosis in vivo and significantly increase RGC survival by targeting secondary rather than primary degeneration.We show that SC transplantation can be monitored in real time and that the protective effects of SCs are associated with targeting secondary degeneration, with implications for translating cell-based therapies to the clinic.

View Article: PubMed Central - PubMed

Affiliation: Glaucoma and Retinal Neurodegeneration Research, Visual Neuroscience, UCL Institute of Ophthalmology, London, UK.

ABSTRACT
Cell-based therapies are increasingly recognized as a potential strategy to treat retinal neurodegenerative disease. Their administration, however, is normally indirect and complex, often with an inability to assess in real time their effects on cell death and their migration/integration into the host retina. In the present study, using a partial optic nerve transection (pONT) rat model, we describe a new method of Schwann cell (SC) delivery (direct application to injured optic nerve sheath, SC/DONS), which was compared with intravitreal SC delivery (SC/IVT). Both SC/DONS and SC/IVT were able to be assessed in vivo using imaging to visualize retinal ganglion cell (RGC) apoptosis and SC retinal integration. RGC death in the pONT model was best fitted to the one-phase exponential decay model. Although both SC/DONS and SC/IVT altered the temporal course of RGC degeneration in pONT, SC/DONS resulted in delayed but long-lasting effects on RGC protection, compared with SC/IVT treatment. In addition, their effects on primary and secondary degeneration, and axonal regeneration, were also investigated, by histology, whole retinal counting, and modelling of RGC loss. SC/DONS was found to significantly reduce RGC apoptosis in vivo and significantly increase RGC survival by targeting secondary rather than primary degeneration. Both SC/DONS and SC/IVT were found to promote RGC axonal regrowth after optic nerve injury, with evidence of GAP-43 expression in RGC somas and axons. SC/DONS may have the potential in the treatment of optic neuropathies, such as glaucoma. We show that SC transplantation can be monitored in real time and that the protective effects of SCs are associated with targeting secondary degeneration, with implications for translating cell-based therapies to the clinic.

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Diagram of administrations of SCs in pONT. Schematic diagram shows SC/DONS and SC/IVT transplantation of SCs in a rat pONT model. SCs were administered directly to the ON sheath in the SC/DONS application after pONT (0.2 mm cut was made in the dorsal optic nerve), whereas with SC/IVT SCs were injected into the vitreous 3 days before pONT
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fig1: Diagram of administrations of SCs in pONT. Schematic diagram shows SC/DONS and SC/IVT transplantation of SCs in a rat pONT model. SCs were administered directly to the ON sheath in the SC/DONS application after pONT (0.2 mm cut was made in the dorsal optic nerve), whereas with SC/IVT SCs were injected into the vitreous 3 days before pONT

Mentions: To minimize invasive procedures, SC/DONS was only made once during the surgery of pONT. SCs (2 × 108cells/ml) were mixed with Matrigel in a 1 : 1 ratio immediately before application, and 5 μl of the mixture was administered onto the injured ON at the end of pONT surgery (Figure 1). Having previously shown that ON injury can be evaluated in vivo using DARC (Detection of Apoptotic Retinal Cells),29 we first assessed the effects of SC/DONS with the same method in pONT. Compared with baseline (Figures 2a and b), untreated pONT induced a significant increase in RGC apoptosis at both 7 (Figure 2c, maximal level) and 21 (Figure 2d) days (Figure 2g, P<0.01), which was similar to our previous study.29 SC/DONS significantly reduced RGC apoptosis at both 7 (Figures 2e, g–h, P<0.01) and 21 (Figures 2f, g–h, P<0.05) days compared with untreated pONT. In this experiment, the percentage of RGC apoptosis relative to SC/IVT could not be evaluated due to an overlap of the fluorescence spectra of green fluorescent protein (GFP)-SCs and apoptotic RGCs labelled with annexinV-488. In addition, this study only assessed SC effects following one application during pONT surgery, in order to minimize the number of invasive and anaesthetic procedures. However, to prolong therapeutic efficacy and to mimic the clinical situation, we recognize the need to assess different time points of DONS application. This is to be the subject of future work.


Direct optic nerve sheath (DONS) application of Schwann cells prolongs retinal ganglion cell survival in vivo.

Guo L, Davis B, Nizari S, Normando EM, Shi H, Galvao J, Turner L, Shi J, Clements M, Parrinello S, Cordeiro MF - Cell Death Dis (2014)

Diagram of administrations of SCs in pONT. Schematic diagram shows SC/DONS and SC/IVT transplantation of SCs in a rat pONT model. SCs were administered directly to the ON sheath in the SC/DONS application after pONT (0.2 mm cut was made in the dorsal optic nerve), whereas with SC/IVT SCs were injected into the vitreous 3 days before pONT
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4237238&req=5

fig1: Diagram of administrations of SCs in pONT. Schematic diagram shows SC/DONS and SC/IVT transplantation of SCs in a rat pONT model. SCs were administered directly to the ON sheath in the SC/DONS application after pONT (0.2 mm cut was made in the dorsal optic nerve), whereas with SC/IVT SCs were injected into the vitreous 3 days before pONT
Mentions: To minimize invasive procedures, SC/DONS was only made once during the surgery of pONT. SCs (2 × 108cells/ml) were mixed with Matrigel in a 1 : 1 ratio immediately before application, and 5 μl of the mixture was administered onto the injured ON at the end of pONT surgery (Figure 1). Having previously shown that ON injury can be evaluated in vivo using DARC (Detection of Apoptotic Retinal Cells),29 we first assessed the effects of SC/DONS with the same method in pONT. Compared with baseline (Figures 2a and b), untreated pONT induced a significant increase in RGC apoptosis at both 7 (Figure 2c, maximal level) and 21 (Figure 2d) days (Figure 2g, P<0.01), which was similar to our previous study.29 SC/DONS significantly reduced RGC apoptosis at both 7 (Figures 2e, g–h, P<0.01) and 21 (Figures 2f, g–h, P<0.05) days compared with untreated pONT. In this experiment, the percentage of RGC apoptosis relative to SC/IVT could not be evaluated due to an overlap of the fluorescence spectra of green fluorescent protein (GFP)-SCs and apoptotic RGCs labelled with annexinV-488. In addition, this study only assessed SC effects following one application during pONT surgery, in order to minimize the number of invasive and anaesthetic procedures. However, to prolong therapeutic efficacy and to mimic the clinical situation, we recognize the need to assess different time points of DONS application. This is to be the subject of future work.

Bottom Line: Although both SC/DONS and SC/IVT altered the temporal course of RGC degeneration in pONT, SC/DONS resulted in delayed but long-lasting effects on RGC protection, compared with SC/IVT treatment.SC/DONS was found to significantly reduce RGC apoptosis in vivo and significantly increase RGC survival by targeting secondary rather than primary degeneration.We show that SC transplantation can be monitored in real time and that the protective effects of SCs are associated with targeting secondary degeneration, with implications for translating cell-based therapies to the clinic.

View Article: PubMed Central - PubMed

Affiliation: Glaucoma and Retinal Neurodegeneration Research, Visual Neuroscience, UCL Institute of Ophthalmology, London, UK.

ABSTRACT
Cell-based therapies are increasingly recognized as a potential strategy to treat retinal neurodegenerative disease. Their administration, however, is normally indirect and complex, often with an inability to assess in real time their effects on cell death and their migration/integration into the host retina. In the present study, using a partial optic nerve transection (pONT) rat model, we describe a new method of Schwann cell (SC) delivery (direct application to injured optic nerve sheath, SC/DONS), which was compared with intravitreal SC delivery (SC/IVT). Both SC/DONS and SC/IVT were able to be assessed in vivo using imaging to visualize retinal ganglion cell (RGC) apoptosis and SC retinal integration. RGC death in the pONT model was best fitted to the one-phase exponential decay model. Although both SC/DONS and SC/IVT altered the temporal course of RGC degeneration in pONT, SC/DONS resulted in delayed but long-lasting effects on RGC protection, compared with SC/IVT treatment. In addition, their effects on primary and secondary degeneration, and axonal regeneration, were also investigated, by histology, whole retinal counting, and modelling of RGC loss. SC/DONS was found to significantly reduce RGC apoptosis in vivo and significantly increase RGC survival by targeting secondary rather than primary degeneration. Both SC/DONS and SC/IVT were found to promote RGC axonal regrowth after optic nerve injury, with evidence of GAP-43 expression in RGC somas and axons. SC/DONS may have the potential in the treatment of optic neuropathies, such as glaucoma. We show that SC transplantation can be monitored in real time and that the protective effects of SCs are associated with targeting secondary degeneration, with implications for translating cell-based therapies to the clinic.

Show MeSH
Related in: MedlinePlus