PEP-1-MsrA ameliorates inflammation and reduces atherosclerosis in apolipoprotein E deficient mice

Abstract

BackgroundMethionine sulfoxide reductase A (MsrA) is a potent intracellular oxidoreductase and serves as an essential factor that protects cells against oxidative damage. However, therapeutic use of exogenous MsrA in oxidative stress-induced diseases is limited, because it cannot enter the cells. The aim of this study is to investigate whether MsrA with PEP-1, a cell penetrating peptide, fused to its N-terminus can protect against oxidative stress in macrophages and can attenuate atherosclerosis in apolipoprotein E deficient (apoE−/−) mice.MethodsMsrA and the fusion protein PEP-1-MsrA were expressed and purified using a pET28a expression system. Transduction of the fusion protein into macrophages was confirmed by Western blot and immunofluorescence staining. Intracellular reactive oxygen species (ROS) and apoptosis levels were measured by flow cytometry. In in vivo study, MsrA or PEP-1-MsrA proteins were intraperitoneally injected into apoE−/− mice fed a Western diet for 12 weeks. Plasma lipids levels, inflammatory gene expression, and paraoxonase-1 (PON1) and superoxide dismutase (SOD) activities were assessed. Atherosclerotic lesions were analyzed by Oil Red O staining and immunohistochemistry.ResultsPEP-1-MsrA could penetrate the cells and significantly reduced intracellular ROS levels and apoptosis in H2O2-treated macrophages. It also decreased TNFα and IL-1β mRNA levels and increased the IL-10 mRNA level in lipopolysaccharide-treated macrophages. In in vivo study, PEP-1-MsrA injection significantly increased plasma PON1 and SOD activities and decreased plasma monocyte chemoattractant protein 1 (MCP-1) level compared to the injection of vehicle control or MsrA. In PEP-1-MsrA injected mice, hepatic PON1 levels were increased, while the expression of TNFα and IL-6 mRNA in the liver was suppressed. Although plasma total cholesterol and triglyceride levels did not change, the aortic atherosclerosis in PEP-1-MsrA treated mice was significantly reduced. This was accompanied by a reduction of total and apoptotic macrophages in the lesions.ConclusionOur study provides evidence that PEP-1-MsrA may be a potential therapeutic agent for atherosclerosis-related cardiovascular diseases.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-015-0677-8) contains supplementary material, which is available to authorized users.

Protein methionine oxidation augments reperfusion injury in acute ischemic stroke

“…Using this model, we found that mice with MsrA deficiency were more susceptible to cerebral ischemia/reperfusion injury and were protected by administration of a pharmacological NF-κB inhibitor prior to ischemia (Figure 5 and Figure 6). These findings are concordant with previous studies demonstrating an important role of MsrA in inflammation and NF-κB regulation in atherosclerosis (16) and ischemia/reperfusion injury in myocardium (18). Our observation that NF-κB activation contributes to the increased susceptibility of MsrA −/− mice to cerebral ischemia/reperfusion injury also is consistent with a recent report implicating MsrA in protection from NF-κB activation in rat microglia in a model of neuroinflammation induced by lipopolysaccharide (22).…”

“…These findings suggest that protein methionine oxidation is a key pathological mechanism of reperfusion injury during acute ischemic stroke. Potential therapeutic approaches to target this pathway may include MsrA mimetics (16, 22), CaMKII inhibitors (64), and NF-κB pathway modulators.…”

Cell Penetrating Peptides, Novel Vectors for Gene Therapy

“…Although CPPs have been used as vectors for delivery of drugs [48][49][50][51], other peptides of therapeutic potential [52][53][54][55][56][57][58][59][60], proteins [56,[61][62][63][64][65], radioisotopes [66][67][68][69], quantum dots [70,71] and photosensitizers [72,73], this review will focus on use of CPPs as vectors for nucleic acid delivery, be they genes, oligonucleotides, peptide nucleic acid conjugates, small interfering RNA (siRNA) or the newest application with DNA origami. Although there is literature on all of these applications, most interest and work done to date has been with siRNA.…”

Acacetin exert antioxidant potential against atherosclerosis through Nrf2 pathway in apoE-/- mice

“…For atherosclerosis analysis, the entirety of the aorta was fixed in 4% paraformaldehyde, opened longitudinally and then analyzed en face. The aortic root slides were determined by Oil Red O (ORO) staining and quantification by Image J software as described preciously [19].…”