Maternal high-fat diet promotes calcified atherosclerotic plaque formation in adult offspring by enhancing transformation of vascular smooth muscle cells to osteochondrocytic-like phenotype

Abstract

Abstract Background and objective Maternal high-fat diet (HFD) has been shown to modulate vascular function and remodeling in adult offspring. Atherosclerotic vascular calcification is closely associated with the onset of cardiovascular event. We therefore investigated the impact of maternal HFD on calcification of atherogenic plaques. Methods and results Eight-week-old female apo-E−/− mice (C57BL/6) were fed an HFD or a normal diet (ND) one week prior to mating, and the diet was continued throughout gestation and lactation. Offspring of both groups were fed a high-cholesterol diet (HCD) from 8 weeks of age. Ex vivo osteogenic activity of aortic root and aortic arch was analyzed using in vivo imaging system (IVIS) with OsteoSense 680. Sixteen-week-old male offspring of HFD-fed dams (O-HFD) showed a 1.4-fold increase in fluorescent intensity compared with those of ND-fed dams (O-ND) (p<0.05). Likewise, female O-HFD showed a significantly increased osteogenic activity in aortic arch (154%, p<0.05). Percentages of plaque area and oil red O-positive area were comparable between O-ND and O-HFD of both genders, suggesting that augmented osteogenic activity in O-HFD is not dependent on the plaque size. To investigate the underlying mechanism of augmented calcified plaque formation in O-HFD, vascular smooth muscle cells (VSMCs) of thoracic aorta form 8-week-old male offspring were primarily cultured and VSMCs calcification was induced by treatment with calcification media supplemented with phosphate (2.6 mM). Alizarin-red-positive area upon 10 days stimulation showed a 3.4-fold increase in VSMCs from O-HFD compared with that from O-ND (p<0.01). Consistently, western blotting analysis revealed that expression level of osteocalcin was significantly higher in O-HFD than O-ND, suggesting that osteochondrocytic transformation of VSMCs is augmented in O-HFD. Conclusion Our findings demonstrate that maternal HFD accelerates the development of atherogenic calcification independent of plaque size. In vitro transformation to osteochondrocytic-like cells is enhanced in VSMCs from offspring of HFD-fed dams. Inhibition of VSMCs skewing toward osteochondrocytic-like cells could be a potential therapeutic target for preventing the development of atherosclerotic vascular calcification. Funding Acknowledgement Type of funding source: None