Proteomic and Systems Biology Analysis of Monocytes Exposed to Securinine, a GABAA Receptor Antagonist and Immune Adjuvant

Abstract

Securinine, a GABAA receptor antagonist, has been reported to enhance monocyte cell killing of Coxiella burnetii without obvious adverse effects in vivo. We employed multiplex 2D gel electrophoresis using Zdyes, a new generation of covalently linked fluorescent differential protein detection dyes to analyze changes in the monocyte proteome in response to Securinine. Securinine antagonism of GABAA receptors triggers the activation of p38. We used the differential protein expression results to guide a search of the literature and network analysis software to construct a systems biology model of the effect of Securinine on monocytes. The model suggests that various metabolic modulators (fatty acid binding protein 5, inosine 5′-monophosphate dehydrogenase, and thioredoxin) are at least partially reshaping the metabolic landscape within the monocytes. The actin bundling protein L-plastin, and the Ca2+ binding protein S100A4 also appear to have important roles in the immune response stimulated by Securinine. Fatty acid binding protein 5 (FABP5) may be involved in effecting lipid raft composition, inflammation, and hormonal regulation of monocytes, and the model suggests that FABP5 may be a central regulator of metabolism in activated monocytes. The model also suggests that the heat shock proteins have a significant impact on the monocyte immune response. The model provides a framework to guide future investigations into the mechanisms of Securinine action and with elaboration may help guide development of new types of immune adjuvants.

Securinine suppresses osteoclastogenesis and ameliorates inflammatory bone loss

“…Sec accelerated macrophage killing of phase II Coxiella burnetii in vitro and also induced the release of IL-8, which promotes osteoclast differentiation in macrophages. It has also been reported that Sec increased the monocyte maturation through upregulation of Hsp70 (Shipman et al, 2012). Contrary to this report, the present study showed that Sec directly inhibits the differentiation of osteoclasts.…”

In-Depth Proteomic Characterization of Classical and Non-Classical Monocyte Subsets

“…There has been some genome-wide transcriptomics analysis [ 6 , 13 , 14 ] of individual monocyte subsets, but less information at the protein level is available. Most proteomic analyses performed on monocytes have used monocyte derived cell lines or with the whole monocyte population [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ]. Wong’s group have carried out proteomic analysis on purified monocyte populations [ 43 , 44 ], where they used iTRAQ to determine differences between cell populations.…”

Physiological, biomass elemental composition and proteomic analyses of Escherichia coli ammonium-limited chemostat growth, and comparison with iron- and glucose-limited chemostat growth

“…ZDYE-stained protein spot volumes were measured using a Typhoon Trio gel scanner (GE Healthcare Life Sciences). For protein identification, blue silver-stained protein gel spots were manually excised and proteins identified using an Agilent 6520 Accurate-Mass Q-TOF Chip LC/MS system (Agilent Technologies) (Dratz & Grieco, 2009;Shipman et al, 2012).…”