title: Proteomic profiling of high glucose primed monocytes identifies cyclophilin A as a potential secretory marker of inflammation in type 2 diabetes.
abstract: Hyperglycemia is widely recognized to be a potent stimulator of monocyte activity, which is a crucial event in the pathogenesis of atherosclerosis. We analyzed the monocyte proteome for potential markers that would enhance the ability to screen for early inflammatory status in Type 2 diabetes mellitus (T2DM), using proteomic technologies. Monocytic cells (THP-1) were primed with high glucose (HG), their protein profiles were analyzed using 2DE and the downregulated differentially expressed spots were identified using MALDI TOF/MS. We selected five proteins that were secretory in function with the help of bioinformatic programs. A predominantly downregulated protein identified as cyclophilin A (sequence coverage 98%) was further validated by immunoblotting experiments. The cellular mRNA levels of cyclophilin A in various HG-primed cells were studied using qRT-PCR assays and it was observed to decrease in a dose-dependent manner. LC-ESI-MS was used to identify this protein in the conditioned media of HG-primed cells and confirmed by Western blotting as well as ELISA. Cyclophilin A was also detected in the plasma of patients with diabetes. We conclude that cyclophilin A is secreted by monocytes in response to HG. Given the paracrine and autocrine actions of cyclophilin A, the secreted immunophilin could be significant for progression of atherosclerosis in type 2 diabetes. Our study also provides evidence that analysis of monocyte secretome is a viable strategy for identifying candidate plasma markers in diabetes.
authors.affiliation: Cardiovascular Disease Biology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India.
authors.forename: Surya
authors.initials: S
authors.lastname: Ramachandran
authors.forename: Anila
authors.initials: A
authors.lastname: Venugopal
authors.forename: K
authors.initials: K
authors.lastname: Sathisha
authors.forename: G
authors.initials: G
authors.lastname: Reshmi
authors.forename: Sona
authors.initials: S
authors.lastname: Charles
authors.forename: G
authors.initials: G
authors.lastname: Divya
authors.forename: N S Pratap
authors.initials: NS
authors.lastname: Chandran
authors.forename: Ajit
authors.initials: A
authors.lastname: Mullassari
authors.forename: M Radhakrishna
authors.initials: MR
authors.lastname: Pillai
authors.forename: C C
authors.initials: CC
authors.lastname: Kartha
mesh_terms: D002460:Cell Line; D002478:Cells, Cultured; D021984:Cyclophilin A / Q000235:genetics / Q000276:immunology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000235:genetics / Q000276:immunology*; D005260:Female; D005786:Gene Expression Regulation; D005947:Glucose / Q000276:immunology*; D006801:Humans; D007249:Inflammation / Q000175:diagnosis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism; D020543:Proteome / Q000235:genetics / Q000276:immunology*; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D020543:Proteome; D012333:RNA, Messenger; D021984:Cyclophilin A; D005947:Glucose