title: Toll-Like Receptor 9 Inactivation Alleviated Atherosclerotic Progression and Inhibited Macrophage Polarized to M1 Phenotype in ApoE-/- Mice.
abstract: OBJECTIVE
  Toll-like receptor 9 (TLR9) is involved in many inflammatory diseases, but its role in atherosclerosis remains controversial. This study aimed to investigate the role of TLR9 in atherosclerosis development and macrophage polarization.
  
  
  METHODS
  ApoE(-/-) mice were treated with vehicle or IRS869 for 12 weeks. Plaque vulnerability was assessed with immunohistochemical analysis, picro-sirius red, and oil red O staining. The expressions of M1- and M2-associated markers in plaques were detected by RT-PCR and immunofluorescence. The aorta TLR9 and its downstream molecules including myeloid differentiation protein 88 (MyD88), phosphorylated nuclear factor-kappa B (p-NF-κB), and interferon regulatory factor 7 (IRF7) were determined by western blot analysis. The frequency of M1 and M2 subtype in RAW264.7 cells treated with IRS869 and/or ODN1826 was evaluated with flow cytometry.
  
  
  RESULTS
  In ApoE(-/-) mice, functional inactivation of TLR9 pathway resulted in attenuated atherosclerosis development, as manifested by reduced plaque burden and by decreased plaque vulnerability. Mechanistically, TLR9 inhibition prevented the activation of MyD88/NF-κB pathway and shifted the balance of M1/M2 toward M2 macrophages that were involved.
  
  
  CONCLUSIONS
  Our data indicated that TLR9 inactivation ameliorated atherosclerosis via skewing macrophage plasticity to M2 phenotype in ApoE-deficient mice. These findings may provide a promising therapeutic strategy for atherosclerosis.
authors.affiliation: Cardiovascular Department, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian 362000, China ; Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan, Shandong 250012, China.
authors.forename: Chunmei
authors.initials: C
authors.lastname: Ma
authors.affiliation: Cardiovascular Department, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian 362000, China ; Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan, Shandong 250012, China.
authors.forename: Qiufang
authors.initials: Q
authors.lastname: Ouyang
authors.affiliation: Cardiovascular Department, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian 362000, China.
authors.forename: Ziyang
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Rheumatism Department, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian 362000, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Chen
authors.affiliation: Rheumatism Department, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian 362000, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Rheumatism Department, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian 362000, China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Hu
authors.affiliation: Rheumatism Department, Second Affiliated Hospital and Second Clinical Medical College, Fujian Medical University, Quanzhou, Fujian 362000, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Lin
mesh_terms: D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics* / Q000378:metabolism; D050197:Atherosclerosis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D002460:Cell Line; D005260:Female; D050839:Interferon Regulatory Factor-7 / Q000235:genetics / Q000378:metabolism; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D051217:Toll-Like Receptor 9 / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D001057:Apolipoproteins E; D050839:Interferon Regulatory Factor-7; C494235:Irf7 protein, mouse; D016328:NF-kappa B; C495370:Tlr9 protein, mouse; D051217:Toll-Like Receptor 9