The hallmark lesions of age-related macular degeneration (AMD) are drusen and basal linear deposit which are lipid substances deposited in Bruch membrane or the compartment on the Bruch membrane. There is a prevailing hypothesis that lipid and its oxidized derivant deposited in retina may have important roles in the pathogenesis of AMD. Lipid oxidation products are toxic, may affect the adjacent cells, induce inflammation, and trigger neovascularization.7-ketocholestoral (7KCh), a naturally occurring oxidized form of cholesterol, had been found to be toxic to retinal cells and able to induce chronic inflammation, which may play a critical role in the development of AMD. However the precise mechanism remains to be elucidated. Thus we will make a brief review of 7KCh and its association with AMD.
Purpose To detect whether a 3243 point mutation existed in age-related macular degeneration (AMD). MethodsTwenty-six cases of wet form AMD patients, ten cases of dry form AMD patients were selected,and compared with twenty nomal controls. After collecting anti-coagulated blood samples, total cellular DNA were extracted and purified. Using polymerase chain reaction and restriction fragment long polymorphism techniques, the mtDNA Ararr;G point mutation at position 3243 were detected. Results After cleaveded by restriction endonuclease Apa I, a 294 bp fragment remained only in all detected DNA samples including twenty-six wet form AMD, and ten dry form AMD. No any other fragment appeared. The result showed that there was no Ararr;G mutation at position 3243 found in AMD. Conclusion It is suggested that mtDNA 3243 point mutation due to maternal inheritance might be not concerned with both wet form AMD and dry form AMD. (Chin J Ocul Fundus Dis,2000,16:231-232)
MiRNAs are stable small RNAs that are expressed abundantly in animals and plants. They can bind to the 3'-untranslated region of the target mRNA, and regulate its expression at the post-transcriptional level. The miRNAs’ abnormal expression and its following abnormal biological regulation are closely related to the occurrence and development of age-related macular degeneration (AMD), including inflammatory response, oxidative stress injury, phagocytosis dysfunction and abnormal angiogenesis. Since the dysregulation of miR-155, miR-125b and miR-34a seems to play a more important role in AMD, these microRNAs may be expected to become the new biomarkers and therapeutic targets for AMD.