Broad-Spectrum Chemokine Inhibition Reduces Vascular Macrophage Accumulation and Collagenolysis Consistent with Plaque Stabilization in Mice

Abstract

Background: A major determinant of the risk of myocardial infarction is the stability of the atherosclerotic plaque. Macrophage-rich plaques are more vulnerable to rupture, since macrophages excrete an excess of matrix-degrading enzymes over their inhibitors, reducing collagen content and thinning the fibrous cap. Several genetic studies have shown that disruption of signalling by the chemokine monocyte chemoattractant protein 1 reduced the lipid lesion area and macrophage accumulation in the vessel wall. Methods: We have tested whether a similar reduction in macrophage accumulation could be achieved pharmacologically by treating apolipoprotein-E-deficient mice with the chemokine inhibitor NR58-3.14.3. Results: Mice treated for various periods of time (from several days to 6 months) with NR58-3.14.3 (approximately 30 mg/kg/day) consistently had 30–40% fewer macrophages in vascular lesions, compared with mice treated with the inactive control NR58-3.14.4 or PBS vehicle. Similarly, cleaved collagen staining was lower in mice treated for up to 7 days, although this effect was not maintained when treatment time was extended to 12 weeks. The vascular lipid lesion area was unaffected by treatment, but total collagen I staining and smooth muscle cell number were both increased, suggesting that a shift to a more stable plaque phenotype had been achieved. Conclusions: Strategies, such as chemokine inhibition, to attenuate macrophage accumulation may therefore be useful to promote stabilization of atherosclerotic plaques.

Preventive usage of broad spectrum chemokine inhibitor NR58-3.14.3 reduces the severity of pulmonary and hepatic graft-versus-host disease

“…The chemokine inhibitor used in this study, NR58-3.14.3, is a D amino acid peptide that is restrained by intermolecular disulfide linkage, and is derived from a conserved region at the C terminus of CCL2. NR58-3.14.3 inhibits leukocyte migration in response to a range of CXC and CC chemokines, including CCL2, CCL5, CCL3 and CXCL8 [31] and has been successfully used to treat various diseases in experimental animal studies [32,41,42,[48][49][50][51]. At present, the exact molecular mechanisms of NR58-3.14.3 responsible for the functional inhibition of chemokine-induced migration remain unknown.…”

“…If all the panoply of in vivo metabolism systems do not significantly metabolise this reagent, it is highly likely that NR58-3.14.3 is stable in in vitro cultures. In vivo steady state levels in mice achieved by 30 mg/kg body weight daily via an implantable osmotic minipump have been reported with 10-15 lM [48]. However, subcutaneous application in vivo leads to high spike concentrations, followed by a period when drug levels are undetectable due to its pharmacokinetics [41], and it cannot be excluded that differences in drug levels obtained in vivo compared to drug levels present in cell cultures in vitro led to the observed discrepancy of NR58-3.14.3 treatment on alloantigen-specific T cell expansion and activation in vitro and in vivo.…”

Regulation of Atherogenesis by Chemokines and Chemokine Receptors

“…Administration of purified M-T7 into rats caused a significant reduction of intimal hyperplasia after angioplasty injury (Liu et al 2000) and inhibited aortic allograft vasculopathy associated with reduced inflammatory cell invasion (Liu et al 2004; Dai et al 2010), indicating that it may prevent recurrent atherosclerotic plaque growth. NR58-3.14.3 is a broad-spectrum chemokine-blocking peptide that effectively inhibits the activities of CCL2, CCL3, CXCL8 and CXCL12, and treatment of ApoE −/− mice with this peptide significantly reduced macrophage accumulation in vascular lesions and increased the content of collagen and smooth muscle cells, although the vascular lipid lesion area was not changed (Reckless et al 2005). Also, tail-vein injection of a recombinant adenovirus encoding soluble protein 35K , a broad-spectrum CC-chemokine blocking agent encoded by Vaccinia virus, into ApoE −/− mice markedly reduced atherosclerotic plaque formation and atherosclerosis in carotid-caval vein grafts, accompanied by decreased macrophage recruitment into the lesions (Ali et al 2005; Bursill et al 2004).…”

The role of chemokines in recruitment of immune cells to the artery wall and adipose tissue

“…Beyond these studies, use of the broad-spectrum CC chemokine inhibitor, NR58-3.14.3 results in reduced macrophage content and cleaved collagen in apoE−/− mice (Reckless et al, 2005). For future studies, combined targeting of multiple chemokine/chemokine receptor pathways or targeting of other atherosclerosis risk factors with supplementation of chemokine inhibition may be effective alternatives.…”