Pigment Epithelium-Derived Factor Is Retinal Ganglion Cell Neuroprotective and Axogenic After Optic Nerve Crush Injury

Abstract

Citation: Vigneswara V, Berry M, Logan A, Ahmed Z. Pigment epithelium-derived factor is retinal ganglion cell neuroprotective and axogenic after optic nerve crush injury. Invest Ophthalmol Vis Sci. 2013;54: 262454: -263354: . DOI: 10.1167 PURPOSE. To investigate neuroprotective and axogenic properties of pigment epitheliumderived factor (PEDF) in retinal ganglion cells (RGC) in vitro and in vivo.METHODS. Adult rat retinal cultures were treated with combinations of PBS and PEDF with or without a cell permeable analogue of cAMP, and RGC survival and neurite lengths quantified. The optic nerves of anesthetised rats were also crushed intraorbitally to transect all RGC axons followed by intravitreal injections of either PBS, PEDF, or cAMPþPEDF every 7 days. RGC were back filled with FluoroGold to quantify RGC survival and longitudinal optic nerve sections were stained with GAP43 antibodies to detect regenerating RGC axons.RESULTS. An optimal dose of 2.5 3 10 À5 lg/lL, promoted 65% more RGC survival than controls in vitro, increasing by 4.4-and 5-fold the number of RGC with neurites and the mean neurite length, respectively. Addition of cAMP with or without PEDF did not potentiate RGC survival or the mean number of RGC with neurites, but enhanced RGC neurite length by 1.4-fold, compared with PEDF alone. After optic nerve crush (ONC), PEDF protected RGC from apoptosis and increased the numbers of regenerating RGC axons in the optic nerve by 4.6-and 3.4-fold, respectively when compared with controls. cAMP did not enhance PEDF-induced RGC neuroprotection, but potentiated its neuroregenerative effects by 2-to 3-fold, increasing the number of RGC axons regenerating at 500 and 1000 lm from the lesions site.CONCLUSIONS. This study is the first to demonstrate that PEDF enhances both RGC survival and axon regeneration in vitro and in vivo.Keywords: PEDF, retinal ganglion cells, neuroprotection, axon regeneration, optic nerve R etinal ganglion cells (RGC) rapidly die after axotomy, but are protected by combinatorial treatments with neurotrophic factors (NTF), including brain-derived NTF (BDNF), neurotrophin-3/4 (NT-3/4), ciliary neurotrophic factor (CNTF), glial cell line-derived neurotrophic (GDNF), and basic fibroblast growth factor (FGF2). 1-7 NTF combinations also activate intrinsic axon growth signalling pathways that initiate RGC axon regeneration.1-7 Pigment epithelium-derived factor (PEDF) is a 50 kDa NTF glycoprotein belonging to the serpin superfamily, that protects a wide range of central nervous system (CNS) neurons. [8][9][10][11][12][13][14][15] Although first isolated from fetal human retinal pigment (choroid) epithelial cells, like many other NTF, PEDF is expressed in a wide variety of tissues including brain, spinal cord, skeletal muscle, heart, endothelial cells, and osteoblasts. [16][17][18][19][20] PEDF has an array of unique properties including neuroprotective, anti-angiogenic, antiinflammatory, anti-oxidative, and antitumorigenic activities. [21][22][23][24][25][26][27] PEDF is a multifaceted NTF that ...

AMPA receptor desensitization is the determinant of AMPA receptor mediated excitotoxicity in purified retinal ganglion cells

“…When comparing RGCs treated with s-AMPA along with trophic factor deprivation and trophic factor deprivation group alone, no significant changes were observed in the number of viable cells, however an increase in RGC neurite expression was observed. A previous study demonstrated that treatment of cAMP (a precursor to p-CREB) in RGCs was not able to induce soma protection but was able to promote neuritogenesis (Vigneswara et al, 2013), thus possibly providing an explanation as to why in our study AMPAR activation in RGC was not protective against injury but showed an increase in the number of neurites. Similarly, neuritogenesis following AMPAR stimulation has also been observed in cerebral cortex neurons (Monnerie and Le Roux, 2006).…”

siRNA-Mediated Knockdown of the mTOR Inhibitor RTP801 Promotes Retinal Ganglion Cell Survival and Axon Elongation by Direct and Indirect Mechanisms

“…After analgesia with subcutaneous injection of buprenorphine (0.1 mL/100 g; National Veterinary Supplies), animals were anesthetized, secured in a headholding frame, and underwent bilateral ONC as described previously. 53,54 Briefly, after a midline cutaneous incision, the ON was exposed through a superior orbital approach and crushed with forceps 2 mm from the lamina cribrosa, within the dural sheath to sever all RGC axons while preserving retinal vascular supply.…”

“…Animals were killed by CO 2 overdose, and retinae dissociated into single cells using a papain dissociation kit in accordance with the manufacturer's protocols (Worthington Biochemicals, Lakewood, NJ, USA), as described previously. 19,54 Retinal cells were plated at a density of 125,000 cells per well into 8-well chamber slides (BD Biosciences, Erembodegem, Belgium) precoated with poly-Dlysine and laminin, in 300 lL/well Neurobasal A with B27 supplement and gentamicin (sNBA; all from Invitrogen, Paisley, UK). To assess the effect of siRTP801 on RGC survival and neurite outgrowth in the presence of activated retinal glia, additional cultures were prepared from animals 5 days after ONC (as described above).…”

Short‐term effect of intravitreal ranibizumab on intraocular concentrations of vascular endothelial growth factor‐A and pigment epithelium‐derived factor in neovascular glaucoma

“…PEDF plays thus a critical role in the homeostasis of angiogenesis in ocular tissues. In addition, PEDF exhibits a variety of other biological properties including anti‐apoptotic, anti‐inflammatory, antioxidative and neuroprotective effects …”

“…In addition, PEDF exhibits a variety of other biological properties including anti-apoptotic, antiinflammatory, antioxidative and neuroprotective effects. [11][12][13][14][15] As some of the most powerful stimulators and inhibitors of angiogenesis, VEGF-A and PEDF are interwoven with each other. PEDF acts as a major antagonistic component, while VEGF-A is the predominant cytokine in promoting angiogenesis.…”