In:
Arteriosclerosis, Thrombosis, and Vascular Biology, Ovid Technologies (Wolters Kluwer Health), Vol. 35, No. suppl_1 ( 2015-05)
Abstract:
HDL mimetic peptides hold promise for the treatment of cardio-metabolic diseases. Transient increases in plasma TG and/or safety concerns may limit their therapeutic applications however, particularly in high risk patients with hypertriglyceridemia and diabetes. Presently, we sought to identify peptide structural features responsible for these adverse effects. The single helix peptide ATI-5261 was used as a model, since it forms a class A α-helix like many HDL mimetic peptides and has exceptional secondary structure and solubility. High dose ip injection (300 mg/kg) of ATI-5261 induced muscle toxicity in C57Bl/6 mice vs. vehicle (serum CPK@4 h = 32,314±2359 vs 143±44 IU/L), increased ALT and AST activities (233±10 & 4595±933 vs 26±6 & 84±21 IU/L) and elevated plasma TG (1951±77 vs 37±7 mg/dl). A majority (~90%) of the cytotoxicity and TG increase was eliminated by removing phenylalanine residues from the apolar face of ATI-5261. Similar results were obtained by removing cationic arginine residues from the lipid-water interface. Thus both features were necessary, but each not sufficient, to induce cytotoxicity and TG elevations. Based on this, a peptide (CS6253) was created that was non-toxic (no adverse effect level 〉 500 mg/kg; t1/2 =7.0±0.6 h in rats), retained secondary structure (75±5% α-helicity), high solubility and ability to stimulate ABCA1-dependent cholesterol efflux efficiently (Km=0.80±0.40 vs. 0.86±0.25 μg/ml ATI-5261). In vivo CS6253 was TG neutral, promoted macrophage RCT, and reduced (32%) substantial atherosclerosis in apoE KO mice fed western diet 10 wks (lesion area = 22±4 vs. 15±2% with 30 mg CS6253/kg, ip injection every 48 h for 6 wks, p 〈 0.01) and improved glucose - and insulin- tolerance tests with lowering of HbA1c levels in C57Bl/6 mice fed high-fat diet (DIO model). In summary, the cytotoxic and TG elevating effects of high-dose ATI-5261 were dependent on class A α-helix structure. CS6253 with its improved safety margin represents a novel ABCA1 ligand peptide with potential to treat diabetes and associated cardiovascular disease.
Type of Medium:
Online Resource
ISSN:
1079-5642
,
1524-4636
DOI:
10.1161/atvb.35.suppl_1.28
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2015
detail.hit.zdb_id:
1494427-3
