title: AIM2 facilitates the apoptotic DNA-induced systemic lupus erythematosus via arbitrating macrophage functional maturation.
abstract: OBJECTIVE
  Lupus nephritis, a major cause of morbidity in patients with systemic lupus erythematosus (SLE), is generally thought to be induced by macrophage-mediated inflammation following deposition of various autoantibodies in kidneys. We previously reported that macrophage aberrant activation induced by activated lymphocyte-derived apoptotic DNA (apopDNA) have been found to play pathogenic roles in the immunodysregulation in lupus nephritis. However, DNA sensor(s) involved in apopDNA-induced macrophage activation and lupus nephritis remains largely undefined. Herein, we aimed to reveal the DNA sensor(s) involved in SLE disease.
  
  
  METHODS
  Correlation between the level of absent in melanoma 2 (AIM2), a cytoplasmic DNA receptor in the inflammasome pathway, and the clinical severity of SLE disease were analyzed in SLE patients as well as in lupus mice. Activated macrophages induced by apopDNA were analyzed by real-time PCR and western blot for AIM2 expression. After silencing of AIM2 via siRNA-mediated knockdown in vitro and in vivo, macrophage activation, inflammatory response, and SLE syndrome were assessed.
  
  
  RESULTS
  AIM2 expression was closely correlated with the severity of disease in SLE patients and in lupus mice. Importantly, AIM2 expression was significantly increased in apopDNA-induced macrophages and closely correlated with macrophage activation. Knockdown of AIM2 significantly blunted apopDNA-induced macrophage activation. Furthermore, blockade of AIM2 expression notably ameliorated SLE syndrome via impeding macrophage activation and dampening inflammatory response in apopDNA-induced lupus mice.
  
  
  CONCLUSIONS
  Our results implied that AIM2 might act as an important DNA sensor and a potential biomarker for apopDNA-induced macrophage functional maturation and SLE disease.
authors.affiliation: Institute for Immunobiology and Department of Immunology, Shanghai Medical College, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China.
authors.forename: Weijuan
authors.initials: W
authors.lastname: Zhang
authors.forename: Yanxing
authors.initials: Y
authors.lastname: Cai
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Zhinan
authors.initials: Z
authors.lastname: Yin
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Gao
authors.forename: Sidong
authors.initials: S
authors.lastname: Xiong
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000974:Antibodies, Antinuclear / Q000276:immunology; D017209:Apoptosis / Q000235:genetics* / Q000276:immunology; D002478:Cells, Cultured; D004247:DNA / Q000235:genetics* / Q000276:immunology; D004268:DNA-Binding Proteins; D005260:Female; D006801:Humans; D058847:Inflammasomes / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008180:Lupus Erythematosus, Systemic / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D008181:Lupus Nephritis / Q000235:genetics; D008262:Macrophage Activation / Q000235:genetics* / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008545:Melanoma / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D017008:Negotiating; D009687:Nuclear Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D055815:Young Adult
chemical_list: C410167:AIM2 protein, human; C540422:Aim2 protein, mouse; D000974:Antibodies, Antinuclear; C033365:DNA receptor; D004268:DNA-Binding Proteins; D058847:Inflammasomes; D009687:Nuclear Proteins; D011956:Receptors, Cell Surface; D004247:DNA