First Author | Harada T | Year | 2004 |
Journal | Am J Pathol | Volume | 164 |
Issue | 1 | Pages | 59-64 |
PubMed ID | 14695319 | Mgi Jnum | J:88434 |
Mgi Id | MGI:3033270 | Doi | 10.1016/S0002-9440(10)63096-9 |
Citation | Harada T, et al. (2004) Role of ubiquitin carboxy terminal hydrolase-L1 in neural cell apoptosis induced by ischemic retinal injury in vivo. Am J Pathol 164(1):59-64 |
abstractText | Ubiquitin is thought to be a stress protein that plays an important role in protecting cells under stress conditions; however, its precise role is unclear. Ubiquitin expression level is controlled by the balance of ubiquitinating and deubiquitinating enzymes. To investigate the function of deubiquitinating enzymes on ischemia-induced neural cell apoptosis in vivo, we analyzed gracile axonal dystrophy (gad) mice with an exon deletion for ubiquitin carboxy terminal hydrolase-L1 (UCH-L1), a neuron-specific deubiquitinating enzyme. In wild-type mouse retina, light stimuli and ischemic retinal injury induced strong ubiquitin expression in the inner retina, and its expression pattern was similar to that of UCH-L1. On the other hand, gad mice showed reduced ubiquitin induction after light stimuli and ischemia, whereas expression levels of antiapoptotic (Bcl-2 and XIAP) and prosurvival (brain-derived neurotrophic factor) proteins that are normally degraded by an ubiquitin-proteasome pathway were significantly higher. Consistently, ischemia-induced caspase activity and neural cell apoptosis were suppressed approximately 70% in gad mice. These results demonstrate that UCH-L1 is involved in ubiquitin expression after stress stimuli, but excessive ubiquitin induction following ischemic injury may rather lead to neural cell apoptosis in vivo. |