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Updated: Mar 30, 2026
Encapsulated Cell Technology for the Delivery of Biologics to the Mouse Eye
Published on: March 30, 2020
Intravitreal Ciliary Neurotrophic Factor Transiently Improves Cone-Mediated Function in a CNGB3-/- Mouse Model of
Dario Marangoni1, Camasamudram Vijayasarathy2, Ronald A Bush2
1National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States 3Department of Biotechnology and Applied Clinical Science, University of L'Aquila, L'Aquila, Italy.
Purpose:
Ciliary neurotrophic factor (CNTF) was recently shown to augment cone function in CNGB3 mutant achromat dogs. However, testing CNTF-releasing implant in human CNGB3 achromats failed to show benefit. We evaluated the effects of CNTF protein on the retinal function in an additional achromatopsia model, the CNGB3-/- mouse.
Methods:
Fifty-nine CNGB3-/- mice (postnatal day [PD] ± SD = 30 ± 7) received a unilateral intravitreal injection of 1 or 2 μg CNTF protein, and 15 wild-type (WT) mice (PD = 34 ± 3) received 1 μg CNTF. Retinal function was evaluated by flash ERG and photopic flicker ERG (fERG) at 7 and 14 days after treatment.
Results:
Seven days post CNTF, the photopic b-wave Vmax was significantly increased in CNGB3-/- mice (P < 0.01), whereas it was reduced in WT mice (P < 0.05). Ciliary neurotrophic factor significantly increased the amplitude of photopic fERG and the photopic oscillatory potentials (OPs) in CNGB3-/- mice. Ciliary neurotrophic factor did not alter the scotopic a-wave in either CNGB3-/- or WT mice, but it increased the scotopic b-wave k (P < 0.01) in CNGB3-/- mice, indicating diminished scotopic sensitivity, and reduced the scotopic b-wave Vmax in WT mice (P < 0.05). No difference was found in ERG parameters between 1 or 2 μg CNTF. Fourteen days after CNTF injection the ERG changes in CNGB3-/- mice were lost.
Conclusions:
Intravitreal bolus CNTF protein caused a small and transient improvement of cone-mediated function in CNGB3-/- mice, whereas it reduced rod-mediated function. The increase in photopic OPs and the lack of changes in scotopic a-wave suggest a CNTF effect on the inner retina.
