BACKGROUND: Iron metabolism disorder has been proved to be a key factor of Parkinson's disease, but research on brain iron metabolism is still immature, and the role of glial cells in the brain iron metabolism remains unclear. Many studies have pointed that microglia plays an important role in the pathogenesis of Parkinson's disease, which closely related to iron.OBJECTIVE: To further explore the relationship between microglia and neurons in iron metabolism based on our previous study, and to clarify the role of microglia in iron-induced selective damaged dopaminergic neurons of Parkinson's disease.METHODS: This was an in vitro cellular experiment, which was finished in the Medical College of Qingdao University, Shandong Province, China. The effects of conditioned medium of microglia on the survival rate of mesencephalic neurons and iron metabolism were observed by changing the iron levels in microglia.Lipopolysaccharide was used to activate different iron-loaded microglia, and then the effects of conditioned medium on the survival rate of mesencephalic neurons and iron metabolism were determined. The effects of different iron levels in microglia on microglia and inflammatory factors and lactoferrin released from the activated microglia were detected by siRNA and ELISA. The effects of these inflammatory factors and lactoferrin on the survival of mesencephalic neurons and iron metabolism were observed. The iron levels in mesencephalic neurons were changed, and then added into the above conditioned medium to observe the survival of neurons and iron metabolism. This experimental protocol was approved by the Hospital Ethics Committee (No. 01482311234). All experimental procedures were performed in accordance with the Guide for the Care and Use of Laboratory Animals issued by the United States National Institutes of Health.RESULTS AND CONCLUSION: Our study results show that the function of microglia is closely related to the iron metabolism in nigra dopaminergic neurons. Research on the rational use of microglia to prevent neuronal degeneration gives a strong impetus to the prevention and treatment of Parkinson's disease.