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Abstract: FR-PO154

The Effect of Autophagic Flow in the Phenotype Transformation of Macrophage M1/M2

Session Information

Category: Glomerular Diseases

  • 1201 Glomerular Diseases: Fibrosis and Extracellular Matrix

Authors

  • Liu, Yuqiu, Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
  • Jiang, Yuteng, Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
  • Zhao, Yu, Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
  • Zhu, Xiaodong, Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
  • Wu, Beibei, Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, China
  • Zhang, Xiaoliang, Zhong Da Hospital, Southeast University, School of Medicine, Nanjing, JIANGSU , China
Background

Macrophage infiltration is an important histopathological feature of kidney disease, and its activation state in the microenvironment is the main factor determines disease prognosis. Autophagy is a process in which lysosomes degrade their own damaged and excess proteins. It’s highly dynamic, also known as autophagic flow. In this study, macrophages were cultured in vitro to fully observe the levels of autophagic flow and the effects on the M1/M2 phenotype transformation.

Methods

The macrophages RAW264.7 were stimulated with IFN-γ+LPS and IL-4 for 24h to induce M1 and M2 activation. Use of autophagosome-generating activator (RAPA), autophagosome production inhibitor (3-MA), autolysosome fusion inhibitor (BAFA) and autolysosome degradation inhibitor (CQ) to intervene M1/M2 for 24h. The expression levels of M1 markers, M2 markers and autophagy markers were detected by western blot and immunofluorescence. Then using an electron microscope to observe autophagic flow.

Results

1. The expression of M1 markers (iNOS, TNF-α) increased with IFN-γ+LPS. Instead, IL-4 stimulated activation of M2 that the levels of MR and Arg-1 increased. 2. Autophagy-related proteins LC3 and Beclin-1 had higher level in M2 cells with the level of autophagy specific degradation protein p62 decreased, suggesting the autophagy level of M2 cells was higher than that of M1 cells. 3. The autophagosome formation, fusion of autophagosomes with lysosomes, autolysosome formation, and substrate degradation were observed by EM. 4.For M1 cells, RAPA increased the expression of LC3, Beclin-1 and p62, while those decreased with 3-MA. After BAFA intervention, the expression of LC3 and Beclin-1 decreased, when p62 was significantly increased. But the expression of LC3-II, Beclin-1 and p62 showed a tendency to increase after CQ intervention. 5.Activation of autophagy induced the transformation of M2 cells, while inhibition of autophagy induced M1 activation.

Conclusion

Autophagic flow can regulate the mutual transformation of macrophage M1/M2 phenotype. But changes in a single marker can’t confirm the level of autophagy in the cell, the dynamic changes in autophagy flow need to be evaluated.