Research On The Signal Transduction In Apoptosis Of The Retinal Cells With Ischemic Optic Neuropathy (ION)

PrefaceThe proliferation and heredity maintenance of biological species, individual development, unification of the body parts and the external environment and organisms are all embedded in the process of signal transduction and regulation in cells. In other words, all vital phenomena are actually the sophisticated processes of signal transduction and regulation, which produce lots of biological effects in cells specifically. Signal transduction and regulation is the basis of the study on vital phenomena.In recent years, many people have noted that papilledema occures when the circulatory disturbance took place in the front end of optic nerve, which caused edema due to hypoxia. This is a mistake that will last as papillitis, or brain tumor patients, it is now recognized that it is a unique disease, called ischemic optic neuropathy. Retinal nerve fiber layers, consisting of the axons from retinal ganglion cells, gather at the posterior pole of eyeball and rotate 90 to form the optic nerve. Apoptosis, or programmed cell death, is a normal component of the development and health of multi-cellular organisms. Cells die in response to a variety of stimuli and during apoptosis they do so in a controlled, regulated fashion. However, in different circumstances, the ways of apoptosis are different. The diversity of the signal transduction pathways in cell apoptosis makes the occurrence and mechanism of apoptosis very complicated. With an increasing number of studies on apoptotic signal systems, we recognized that the signal transduction pathways in apoptosis have waved a complex and huge signal network. If we got an understanding of signal transduction pathways in apoptosis, this means that we could control the occurrence of apoptosis. Low calcium antagonists can be used systemically to alleviate the disease progress of patients with ischemic optic neuropathy. The results indicate that calcium antagonists have great potential function for the clinical treatment to the ischemic optic neuropathy. Research data support the hypothesis that there is a relationship between the vascular dysfunction and the pathogenesis of ischemic optic neuropathy. Based on this concept, we focus on the roles of calcium ion channels in the signal transduction process of apoptosis.Materials and methods一,Animal modelsWistar rats weight 170g-200g are provided by the Animal Center of China Medical University.二,Methods1 Animal model establishment of IONAfter the rats were anesthetized with urethane 2.5%, we used the RB for mydriasis and injected the Bangladesh Rose by tail vein prior to continuous laser irradiation on the optic disc for 20 seconds. In VEP groups, one eye of the rat was hit with laser and the other stayed without a scratch as the control to reduce errors.2 Changes of intracellular calcium in ION ganglion cells and the Ver blocking effectsRats were divided into 6 groups - control, day 1, 3, 5, 7 and Ver treated groups. Fluo3/AM technology and Hitachi F-3000 dual-wavelength fluorescence spectrophotometer were used for experiments Results were automatically calculated by the Quantitative Software in Hitachi F-3000 Calcium Measurement System.3 The activity and content determination of PKC-βin ION ganglion cells Rats were divided into 5 groups - control, day 1, 3, 5, and 7 experimental groups. Western blot method was used to determine the activity and content of PKC-β.4 The c-fos mRNA determination of ION ganglion cells4 The c-fos mRNA determination of ION ganglion cellsRats were divided into 8 groups - control, 15min, 30min, 1h, 2h, 4h, 6h, and 12h experimental groups. Total mRNA was extracted for RT-PCR experiment.Results1 Animal model establishment of IONTail injection with Bangladesh Rose and simple laser irradiation can not cause retinal ischemia. After induction with Bangladesh Rose, the laser can successfully cause ION models. The consequential changes in VEP, and retinal blood supply can be seen by optical microscopy and electron microscopy.2 Changes of intracellular calcium in ION ganglion cells and the Ver blocking effectsThe intracellular calcium increased significantly in ION retinal ganglion cells of apoptosis and decreased obviously in Ver treated cells but still higher than that in the normal cells. Ver significantly reduced the retinal edema (P<0.05).3 . The activity and content determination of PKC-βin ION ganglion cellsIn ION retinal ganglion cell of apoptosis, PKC-βactivity was significantly higherand decreased but higher than that in control.4 The c-fos mRNA determination of ION ganglion cellsC-fos mRNA content is rare in normal circumstances, but begins to increase at 15minutes and peak at 1 hour then gradually reduce to normal at 12h. Conclusions1. After induction with Bangladesh Rose, the laser irradiation can successfully set up ION models.2. During the apoptosis process of ION retinal ganglion cells, intracellular calcium concentration increased and decreased when treated with Ver but still higher than that in the normal. Calcium unbalance may be the starting signal of apoptosis.3. PKC-βis involved in the ION apoptosis process of retinal ganglion cells,which is related with the calcium concentration in the cells.4. The expression of c-fos gene is quick and transient in the ION apoptosis process of retinal ganglion cells.