A novel peptide inhibitor attenuates C-reactive protein's pro-inflammatory effects in-vivo

Abstract

Background: Higher levels of C-reactive protein (CRP) predict cardiovascular events and also portend a poorer prognosis in patients with acute coronary syndromes. Much in-vitro and in-vivo data support a role for CRP in atherogenesis.

Methods: Using the one-bead-one-compound (OBOC) combinatorial library method we have successfully identified peptides against human CRP that inhibit its biological effects in-vitro. Hence we tested the effect of the best characterized inhibitor (CRP-i2) on the effects of CRP in an appropriate animal model, Wistar rats.

Results: Treatment with CRP resulted in significant increase in superoxide anion, nuclear factor kappaB (NFκb) activity and the release of biomarkers of inflammation from macrophages compared to Wistar rats treated with human albumin (HuSA). Pre-treatment with the inhibitor, CRP-i2, resulted in a significant reduction in CRP induced superoxide anion, NFκb activity and biomarkers of inflammation. Also, there were no observed clinical or laboratory related adverse effects.

Conclusions: We demonstrate that our novel peptide inhibitor attenuates the proinflammatory effects of CRP in-vivo. Future studies will examine the long-term effects of this inhibitor on vascular pathobiology.

Keywords: CRP; Inflammation; Macrophages.

Figure 1. Effect of the CRP peptide inhibitor on CRP induced inflammation (in-vivo)

Rats were injected HuSA (10 mg/kg bw) or HCRP (10 mg/kg bw) or HCRP+ CRP inhibitor CRP-i2 for 3 days and euthanized on Day 4. Peritoneal macrophages were obtained and superoxide (Fig 1A), cytokine release (Fig 1B) and NFκb activity (Fig 1C) were assessed as described in Methods. *p<0.05 compared to HuSA; *a, p<0.05 compared to HCRP treated rats.

Figure 1. Effect of the CRP peptide inhibitor on CRP induced inflammation (in-vivo)

Rats were injected HuSA (10 mg/kg bw) or HCRP (10 mg/kg bw) or HCRP+ CRP inhibitor CRP-i2 for 3 days and euthanized on Day 4. Peritoneal macrophages were obtained and superoxide (Fig 1A), cytokine release (Fig 1B) and NFκb activity (Fig 1C) were assessed as described in Methods. *p<0.05 compared to HuSA; *a, p<0.05 compared to HCRP treated rats.

Figure 1. Effect of the CRP peptide inhibitor on CRP induced inflammation (in-vivo)

Rats were injected HuSA (10 mg/kg bw) or HCRP (10 mg/kg bw) or HCRP+ CRP inhibitor CRP-i2 for 3 days and euthanized on Day 4. Peritoneal macrophages were obtained and superoxide (Fig 1A), cytokine release (Fig 1B) and NFκb activity (Fig 1C) were assessed as described in Methods. *p<0.05 compared to HuSA; *a, p<0.05 compared to HCRP treated rats.