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.

WITHDRAWN: Cyclophilin a regulates autophagy of macrophage through PI3K/Akt/mTOR signaling

“…CyPA, an important inflammatory mediator in development of AS, is a potent chemoattractant for leukocytes, monocytes, and lymphocytes; within the plaques, macrophages can secrete large amounts of CyPA when stimulated by ROS [24][25][26]. Studies have shown highly expressed CyPA in advanced atherosclerotic lesions.…”

Cyclophilin A/Cluster of Differentiation 147 Interactions Participate in Early Brain Injury After Subarachnoid Hemorrhage in Rats

“…CyPA has been found to be secreted into the extracellular space by several types of cells, such as foam cells (14), vascular smooth muscle cells (15), and macrophages (16). In patients, higher levels of soluble extracellular CyPA can be detected under inflammatory conditions, for example, in nasal fluids of patients with asthma (35), in plasma of patients with type 2 diabetes (16), and in serum of patients with coronary artery disease (36). The exact mechanism by which CyPA is secreted from the intracellular to extracellular space has not been well described.…”

“…The most abundant of these is cyclophilin A (CyPA), which makes up 0.1-0.6% of all cytosolic proteins (13). Although CyPA is present intracellularly, it can be secreted from cells in response to inflammatory stimuli, such as hypoxia, infection, and oxidative stress (14)(15)(16). cluster of differentiation 147 (CD147), a type I transmembrane protein, was found to be the cell surface signaling receptor for extracellular CyPA.…”

Altered apolipoprotein C expression in association with cognition impairments and hippocampus volume in schizophrenia and bipolar disorder

“…The relationship between metabolic problems, such as obesity, diabetes and elevated lipids, and the expression of Apo has been frequently investigated in the general population (Padrao, Ferreira, Vitorino, & Amado, 2012;Ramachandran et al, 2012;Sadler et al, 2012). Due to antipsychotic medications in SZ and mood stabilisers in BD, those patients have an increased risk for metabolic disturbances and altered lipid metabolism (Gibbons, Thomas, Scarr, & Dean, 2010), ultimately contributing to an increased risk for cardiovascular disease (Meyer et al, 2008).…”