The LEI/L-DNase II pathway is activated in light-induced retinal degeneration in rats

Abstract

Purpose: Retinal death induced by light seems to be a caspase independent process. In this work we investigate the LEI/L-DNase II pathway, a caspase-independent pathway, in light-induced retinal degeneration in Fischer rats.Methods: Measurement of DNase activity in total retinal extracts of light exposed Fischer rats was performed by analysing a plasmid degradation on an agarose gel.The same method was used to measure the in vitro activity of recombinant LEI (reticulocyte lysate) after incubation with calpains.Results: L-DNase II activity is observed in retinal extracts of light exposed Fischer rats and increases with time illumination. In this apoptotic death, the activation of calpains has been shown. Here we show that L-DNase II activation is not catalized by calpains.Conclusion: The present study indicates that the LEI/L-DNase II may be a possible pathway activated during photoreceptor apoptosis in light-induced retinal degeneration but that this pathway is not directly activated by calpains.

Effects of white light‐emitting diode (LED) exposure on retinal pigment epithelium in vivo

“…This was done using an anti‐active‐caspase 3 antibody, an anti‐AIF 58 and an anti‐L‐DNase II 59 for caspase‐independent apoptosis. Contrary to what happens in LIRD, 60, 61 none of these effectors were activated in RPE exposed to LED suggesting the involvement of another type of cell death. Actually, the morphology of nuclei, the modification of Lamin B labelling and the RIP staining in scattered groups of cells and its cleavage indicate the activation of necrosis.…”

Retinal damage induced by commercial light emitting diodes (LEDs)

“…We use the usual model of albinos rat. Although the pertinence of this model and the translation of the results to human being is matter of discussion, it is useful to get an idea of the kind of lesions found with theses new devices as compared with other already investigated in our laboratory [17][18].…”

“…Instead, a caspase-independent cell death pathway, the LEI/L-DNase II was involved in photoreceptor degeneration [18]. The activation of this pathway involves the cleavage, by specific proteases, of the cytoplasmic Leukocyte Elastase Inhibitor (LEI), and its transformation into L-DNase II, a nuclear protein [19].…”

Regulation of Apoptotic Endonucleases by EndoG

“…Three other endonucleases of the DNase 2 group include DNase 2a, DNase 2b, and L-DNase 2 (Evans and Aguilera, 2003;Chahory et al, 2004). Another endonuclease known as caspase-activated DNase (CAD) has been tightly linked to apoptosis (Nagata, 2000).…”