Related Experiment Video
Updated: Apr 17, 2026
A Novel Light Damage Paradigm for Use in Retinal Regeneration Studies in Adult Zebrafish
Published on: October 24, 2013
DNA damage, poly(ADP-Ribose) polymerase activation, and phosphorylated histone H2AX expression during postnatal
David Martín-Oliva1, Sandra M Martín-Guerrero1, Ana M Matia-González2
1Departamento de Biología Celular, Facultad de Ciencias, Universidad de Granada, Granada, Spain.
Purpose:
The purpose of this study was to investigate the incidence of DNA damage during postnatal development of the retina and the relationship between DNA damage and cell death.
Methods:
DNA damage in the developing postnatal retina of C57BL/6 mice was assessed by determining the amounts of 8-hydroxy-2'-deoxyguanosine (8-OHdG), which is indicative of DNA oxidation and related to the formation of DNA single-strand breaks (SSBs), and phosphorylated histone H2AX (γ-H2AX), a marker of DNA double-strand breaks (DSBs). Poly(ADP-ribose) polymerase (PARP) activation was measured by ELISA and Western blotting. The location of γ-H2AX-positive and dying cells was determined by immunofluorescence and TUNEL assays.
Results:
Oxidative DNA damage was maintained at low levels during high PARP activation between postnatal days 0 (P0) and P7. Phosphorylated histone H2AX gradually increased between P0 and P14 and decreased thereafter. Phosphorylated histone H2AX-positive cells with cell death morphology or TUNEL positivity were more abundant at P7 than at P14.
Conclusions:
Oxidative DNA damage in postnatal retina increases during development. It is low during the first postnatal week when PARP-1 activity is high but increases thereafter. The rise in DSBs when PARP activity is downregulated may be attributable to accumulated oxidative damage and SSBs. At P7 and P14, γ-H2AX-positive cells are repairing naturally occurring DNA damage, but some are dying (mostly at P7), probably due to an accumulation of irreparable DNA damage.
Insights
DNA damage in developing mouse retinas increases after the first week, correlating with cell death. High Poly(ADP-ribose) polymerase (PARP) activity in early development may protect against DNA damage, but later decreases may lead to cell death.
Area of Science:
- Ophthalmology
- Molecular Biology
- Developmental Biology
Background:
- Postnatal retinal development involves complex cellular processes.
- DNA damage and repair mechanisms are crucial for maintaining tissue integrity.
- Understanding DNA damage in the developing retina is key to preventing vision impairment.
Purpose of the Study:
- To investigate DNA damage incidence during postnatal retinal development.
- To explore the relationship between DNA damage and cell death in the developing retina.
Main Methods:
- Assessed DNA oxidation (8-hydroxy-2'-deoxyguanosine) and double-strand breaks (phosphorylated histone H2AX).
- Measured Poly(ADP-ribose) polymerase (PARP) activation using ELISA and Western blotting.
- Localized DNA damage and cell death markers via immunofluorescence and TUNEL assays.
Main Results:
- Oxidative DNA damage remained low during high PARP activation (postnatal days 0-7).
- Phosphorylated histone H2AX (DNA double-strand breaks) increased from postnatal day 0 to 14.
- More DNA double-strand break-positive cells exhibited cell death at postnatal day 7 compared to day 14.
Conclusions:
- Oxidative DNA damage rises in the postnatal retina after the first week.
- Decreased PARP activity correlates with increased DNA double-strand breaks and potential cell death.
- Cells attempt to repair DNA damage, but accumulation can lead to cell death, particularly at postnatal day 7.
