PURPOSE. Apolipoprotein A1 (ApoA1) has been shown to inhibit myopia development in chicks, but the underlying biological mechanism remains unknown. Because ApoA1 interacts with cyclic adenosine monophosphate (cAMP) in many cellular systems, we examined whether this interaction is important in myopia development. METHODS. The nonmetabolizable cAMP analogue 8-Bromo-cAMP (8-Br-cAMP) was administered intravitreally to the right eyes of 8-day old chicks for 4 consecutive days. Control eyes received vehicle. Chicks in group 1 received 8-Br-cAMP (0.1 mM or 1 mM) and were fitted with 10 diopter (D) lenses on both eyes, whereas chicks in group 2 (0.1 mM 8-Br-cAMP) wore plano lenses over both eyes. The levels of retinal cAMP and ApoA1 were examined in another two groups of chicks wearing 10 D (group 3) and þ10 D lenses (group 4) over their right eyes for 3 days, respectively (plano over left eyes). RESULTS. The 8-Br-cAMP significantly inhibited development of lens-induced myopia (group 1: 0.1 mM versus vehicle: +1.71 ± 1.22 D versus 8.00±2.19 D; 1 mM versus vehicle: +1.38 ± 1.34 D versus 9.96±1.14 D, mean ± SEM, P < 0.01 for both); 1 mM, but not 0.1 mM 8-Br-cAMP increased expression of retinal ApoA1 levels in right eyes (P < 0.01). The 8-Br-cAMP had minimal effect on normal eye growth. Both retinal cAMP and ApoA1 levels were significantly increased only in hyperopic eyes (group 4). CONCLUSIONS. The 8-Br-cAMP robustly inhibited development of lens-induced myopia. The increase in retinal ApoA1 observed in cAMP-treated and hyperopic eyes suggested a possible interplay between ApoA1 and cAMP in regulating eye growth.
- Apolipoprotein A1
- Cyclic adenosine monophosphate
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience