title: The role of IFI35 in lupus nephritis and related mechanisms.
abstract: OBJECTIVE
  It's reported that multiple genes in the IFN-γ/STAT1 pathway were hypomethylated and associated with the pathogenesis of lupus nephritis (LN). Our previous study using microarray analysis suggested that interferon induced 35-kDa protein (IFI35) was hypomethylated and increased in LN. However, the role of IFI35 in LN and related mechanism remains to be elucidate.
  
  
  METHODS
  The expressions of IFNγR, STAT1, IFI35 and MBD2 in the human kidneys tissues was detected by real-time PCR and Western blot. The protein levels of IFI35 in the human kidney tissues were detected by immunohistochemistry. The methylation status of IFNγR, STAT1 and IFI35 were detected by methylation specific PCR. Cell proliferation assay was evaluated using cell counting kit 8; pcDNA-IFI35 (pcDNA-MBD2) or IFI35 RNAi (MBD2 RNAi) was used to upregulated or downregulated the expression of the IFI35 and MBD2.
  
  
  RESULTS
  The expressions of IFNγR, STAT1 and IFI35 in the LN kidneys were significantly higher than controls. IFI35 was expressed in mesangial cells, and positively correlated with the proliferation of mesangial cells. IFNγR, STAT1and IFI35 was hypomethylated and MBD2 was increased in LN kidneys. In vitro data confirmed those findings: after stimulating with the serum from LN patients, the proliferation of human renal mesangial cells (HRMCs) was increased. The expressions of the three members of IFNγ signal pathway were hypomethylated and upregulated. However, this effect was reversed by MBD2 knockdown. IFI35 promoted the proliferation of HRMCs and was regulated by MBD2.
  
  
  CONCLUSIONS
  Our results demonstrated that IFI35 enhances the proliferation of mesangial cells and was regulated by MBD2 in LN.
authors.affiliation: a Department of Rheumatology , Xiangya Hospital, Central South University , Changsha , Hunan , People's Republic of China.
authors.forename: Lihua
authors.identifier: http://orcid.org/0000-0002-5201-4792
authors.initials: L
authors.lastname: Zhang
authors.affiliation: a Department of Rheumatology , Xiangya Hospital, Central South University , Changsha , Hunan , People's Republic of China.
authors.forename: Honglin
authors.identifier: http://orcid.org/0000-0002-9322-5684
authors.initials: H
authors.lastname: Zhu
authors.affiliation: a Department of Rheumatology , Xiangya Hospital, Central South University , Changsha , Hunan , People's Republic of China.
authors.forename: Yisha
authors.identifier: http://orcid.org/0000-0001-8309-6631
authors.initials: Y
authors.lastname: Li
authors.affiliation: a Department of Rheumatology , Xiangya Hospital, Central South University , Changsha , Hunan , People's Republic of China.
authors.forename: Xiaodan
authors.identifier: http://orcid.org/0000-0002-9453-4980
authors.initials: X
authors.lastname: Dai
authors.affiliation: a Department of Rheumatology , Xiangya Hospital, Central South University , Changsha , Hunan , People's Republic of China.
authors.forename: Bin
authors.identifier: http://orcid.org/0000-0002-2857-6648
authors.initials: B
authors.lastname: Zhou
authors.affiliation: b Department of Immunology and Internal Medicine , University of Texas Southwestern Medical Center , Dallas , TX , USA.
authors.forename: Quanzhen
authors.identifier: http://orcid.org/0000-0002-7257-0489
authors.initials: Q
authors.lastname: Li
authors.affiliation: a Department of Rheumatology , Xiangya Hospital, Central South University , Changsha , Hunan , People's Republic of China.
authors.forename: Xiaoxia
authors.identifier: http://orcid.org/0000-0002-3928-9660
authors.initials: X
authors.lastname: Zuo
authors.affiliation: a Department of Rheumatology , Xiangya Hospital, Central South University , Changsha , Hunan , People's Republic of China.
authors.forename: Hui
authors.identifier: http://orcid.org/0000-0001-5593-8563
authors.initials: H
authors.lastname: Luo
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008181:Lupus Nephritis / Q000378:metabolism*; D050527:Mesangial Cells / Q000378:metabolism; D050794:STAT1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D050799:STAT5 Transcription Factor / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; C085378:IFI35 protein, human; D047908:Intracellular Signaling Peptides and Proteins; C489325:MBD2 protein, human; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050799:STAT5 Transcription Factor; C494092:STAT5A protein, human; D025521:Tumor Suppressor Proteins
keywords: Hypomethylation; IFI35; MBD2; Mesangial cells