Type 2 diabetes enhances arterial uptake of choline in atherosclerotic mice: an imaging study with positron emission tomography tracer ¹⁸F-fluoromethylcholine.

Abstract

BACKGROUND:

Diabetes is a risk factor for atherosclerosis associated with oxidative stress, inflammation and cell proliferation. The purpose of this study was to evaluate arterial choline uptake and its relationship to atherosclerotic inflammation in diabetic and non-diabetic hypercholesterolemic mice.

METHODS:

Low-density lipoprotein-receptor deficient mice expressing only apolipoprotein B100, with or without type 2 diabetes caused by pancreatic overexpression of insulin-like growth factor II (IGF-II/LDLR(-/-)ApoB(100/100) and LDLR(-/-)ApoB(100/100)) were studied. Distribution kinetics of choline analogue (18)F-fluoromethylcholine ((18)F-FMCH) was assessed in vivo by positron emission tomography (PET) imaging. Then, aortic uptakes of (18)F-FMCH and glucose analogue (18)F-fluorodeoxyglucose ((18)F-FDG), were assessed ex vivo by gamma counting and autoradiography of tissue sections. The (18)F-FMCH uptake in atherosclerotic plaques was further compared with macrophage infiltration and the plasma levels of cytokines and metabolic markers.

RESULTS:

The aortas of all hypercholesterolemic mice showed large, macrophage-rich atherosclerotic plaques. The plaque burden and densities of macrophage subtypes were similar in diabetic and non-diabetic animals. The blood clearance of (18)F-FMCH was rapid. Both the absolute (18)F-FMCH uptake in the aorta and the aorta-to-blood uptake ratio were higher in diabetic than in non-diabetic mice. In autoradiography, the highest (18)F-FMCH uptake co-localized with macrophage-rich atherosclerotic plaques. (18)F-FMCH uptake in plaques correlated with levels of total cholesterol, insulin, C-peptide and leptin. In comparison with (18)F-FDG, (18)F-FMCH provided similar or higher plaque-to-background ratios in diabetic mice.

CONCLUSIONS:

Type 2 diabetes enhances the uptake of choline that reflects inflammation in atherosclerotic plaques in mice. PET tracer (18)F-FMCH is a potential tool to study vascular inflammation associated with diabetes.

• Authors: Sanna Hellberg, Johanna M U Silvola, Max Kiugel, Heidi Liljenbäck, Olli Metsälä, Tapio Viljanen, Jari Metso, Matti Jauhiainen, Pekka Saukko, Pirjo Nuutila, Seppo Ylä-Herttuala, Juhani Knuuti, Anne Roivainen, Antti Saraste
• Journal: Cardiovascular diabetology (Cardiovasc Diabetol) Vol. 15 Pg. 26 (Feb 06 2016) ISSN: 1475-2840 [Electronic] England
• PMID: 26852231 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• Cytokines
• Fluorine Radioisotopes
• Radiopharmaceuticals
• fluoromethylcholine
• Choline

Topics

• Animals
• Aorta (diagnostic imaging, metabolism)
• Aortic Diseases (blood, diagnostic imaging, etiology, metabolism)
• Atherosclerosis (blood, diagnostic imaging, etiology, metabolism)
• Biomarkers (blood)
• Choline (administration & dosage, analogs & derivatives, pharmacokinetics)
• Cytokines (blood)
• Diabetes Mellitus, Type 2 (complications)
• Diabetic Angiopathies (blood, diagnostic imaging, etiology, metabolism)
• Disease Models, Animal
• Fluorine Radioisotopes
• Hypercholesterolemia
• Macrophages (metabolism, radiation effects)
• Mice, Inbred C57BL
• Mice, Transgenic
• Plaque, Atherosclerotic
• Positron-Emission Tomography (methods)
• Predictive Value of Tests
• Radiopharmaceuticals (administration & dosage, pharmacokinetics)
• Tissue Distribution