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: Surya Ramachandran, Anila Venugopal, K Sathisha, G Reshmi, Sona Charles, G Divya, N S Pratap Chandran, Ajit Mullassari, M Radhakrishna Pillai, C C Kartha
• Journal: Proteomics (Proteomics) Vol. 12 Issue 18 Pg. 2808-21 (Sep 2012) ISSN: 1615-9861 [Electronic] Germany
• PMID: 22930659 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical References

• Proteome
• RNA, Messenger
• Cyclophilin A
• Glucose

Topics

• Cell Line
• Cells, Cultured
• Cyclophilin A (genetics, immunology)
• Diabetes Mellitus, Type 2 (complications, genetics, immunology)
• Female
• Gene Expression Regulation
• Glucose (immunology)
• Humans
• Inflammation (diagnosis, immunology)
• Male
• Middle Aged
• Monocytes (immunology, metabolism)
• Proteome (genetics, immunology)
• Proteomics
• RNA, Messenger (genetics)
• Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization