Objective To construct bone marrow-derived monocyte-macrophage lineage tracer mice,and to explore its application in the study of ovarian immune mechanism in polycystic ovary syndrome(PCOS).Methods A fluorescent mouse model of macrophages was constructed based on the Cre/LoxP sys-tem,and Lyz2Cre was mated with R26-CAG-LSL-tdTomato tracer mice,and Lyz2Cre was screened by PCR to i-dentify Td-tomatoflox/flox mice.Tissues were collected for laser confocal imaging of frozen sections to detect Lyz2Cre;Td-tomatoflox/flox mouse on macrophage tracing effect.The tracer mice were fed with high fat combined with letrozole gavage to construct an obese PCOS model,and the success of the PCOS model was evaluated by functional and histopathological methods.Finally,immunofluorescence multiplex labeling combined with laser confocal was used to show the distribution and typing of macrophages traced by Td-tomato in physiological o-varies and PCOS ovaries.Results Lyz2Cre was successfully constructed.Td-tomatoflox/flox tracer mice had clear Td-tomato fluorescence signals in macrophage-rich tissues such as liver,lung,spleen,ovaries,and uterus,proving that the tracer mice could be used to study the proliferation,migration and lineage differentiation of bone marrow-derived monocytes-macrophages.HE staining showed that the ovaries in the PCOS model group exhib-ited polycystic changes,and the body weight,ovarian wet weight and blood glucose of the mice were significantly increased(P all＜0.05),indicating that the obese PCOS model was successfully constructed.Immunofluores-cence multi-label detection showed that compared to the control group,the number of hone marrow-derived macrophages in the ovaries in the PCOS group was significantly increased(P＜0.05)and immersed in the cystic follicle cavity,and the proportion of M1 type was significantly increased(P＜0.05).Conclusion Macrophage lineage tracer mice(Lyz2Cre;Td-tomatoflox/flox),and its application found that the number of ovarian bone mar-row-derived macrophages in obese PCOS mice was significantly increased,and the Ml type was presented,which may be the key factor leading to the imbalance of the ovarian immune microenvironment in PCOS,and providing a new model and strategy for in-depth study of the mechanism of macrophages in a variety of diseases.
维普
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