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Calcification of Vascular Smooth Muscle Cells and Imaging of Aortic Calcification and Inflammation
Published on: May 31, 2016
Activating transcription factor 4 regulates stearate-induced vascular calcification
Masashi Masuda1, Tabitha C Ting, Moshe Levi
1Division of Renal Diseases and Hypertension, University of Colorado Denver, Aurora, CO, USA.
Journal of Lipid Research
|May 26, 2012
Summary
Saturated fatty acids like stearate promote vascular calcification by activating the ATF4 pathway. This involves endoplasmic reticulum stress and osteoblastic differentiation in vascular smooth muscle cells, leading to vessel hardening.
Area of Science:
- Cardiovascular Biology
- Molecular Biology
- Cell Biology
Background:
- Stearate, a saturated fatty acid, has been previously shown to promote osteoblastic differentiation and mineralization of vascular smooth muscle cells (VSMC).
- Vascular calcification is a complex process implicated in cardiovascular disease.
- Understanding the molecular mechanisms underlying stearate-induced vascular calcification is crucial.
Purpose of the Study:
- To investigate the molecular mechanisms by which stearate promotes vascular calcification.
- To determine the role of Activating Transcription Factor 4 (ATF4) in stearate-induced vascular calcification.
Main Methods:
- VSMCs were treated with exogenous stearic acid or a stearoyl-CoA desaturase (SCD) inhibitor (CAY10566).
- Expression of ATF4, endoplasmic reticulum (ER) stress markers (p-eIF2α, CHOP, XBP-1), and osteoblastic markers were analyzed.
- ATF4 knockdown using shRNA and ATF4 overexpression using adenovirus were performed.
Main Results:
- Increased stearate levels induced ATF4 expression and activation via the PERK-eIF2α pathway.
- Stearate and SCD inhibition increased ER stress, correlating with ER stearate levels.
- ATF4 knockdown prevented stearate-induced osteoblastic differentiation and mineralization, while ATF4 overexpression promoted vascular calcification.
Conclusions:
- Activation of ATF4 is a key mediator of stearate-induced vascular calcification.
- The PERK-eIF2α pathway and ER stress are involved in this process.
- Targeting ATF4 may offer a therapeutic strategy for preventing vascular calcification.
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