Macrophages and MicroRNA-150 (AUDIO) Washington University School of Medicine Your browser does not support the audio element. Caption Our immune systems can change as we get older, and now researchers at Washington University School of Medicine in St. Louis have found that as immune cells called macrophages age, the changes in those older cells can increase the risks for age-related macular degeneration, a major cause of blindness in the united states. Jim Dryden has more... Credit Washington University BioMed Radio Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.