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Updated: Jul 7, 2026
Calcification of Vascular Smooth Muscle Cells and Imaging of Aortic Calcification and Inflammation
Published on: May 31, 2016
Calcification of aortic smooth muscle cells isolated from spontaneously hypertensive rats
Kouta Kanemaru1, Kazuhiko Seya, Izumi Miki
1Department of Pharmacology, Hirosaki University Graduate School of Medicine, Japan.
Insights
Hypertension accelerates vascular calcification in rat aortic smooth muscle cells (SMCs). This study reveals increased calcification markers and activity in hypertensive rats, suggesting a link via the Msx2-Osterix pathway.
Area of Science:
- Cardiovascular Biology
- Vascular Biology
- Hypertension Research
Background:
- Hypertension and vascular calcification are known cardiovascular disease risk factors.
- The direct relationship between hypertension and vascular calcification remains unclear.
Purpose of the Study:
- To investigate the relevance of hypertension to vascular calcification.
- To examine aortic smooth muscle cells (SMCs) from normotensive and spontaneously hypertensive rats (SHR).
Main Methods:
- Isolated aortic SMCs from Wistar Kyoto rats (WKY) and SHR.
- Cultured cells and performed Von Kossa staining for calcification.
- Analyzed gene expression of calcification-related proteins (Msx2, Osterix, ALP, Runx2) and ALP activity.
Main Results:
- SHR aortic SMCs showed significantly increased calcified area compared to WKY.
- Gene expression of Msx2, Osterix, and alkaline phosphatase (ALP) was upregulated in SHR SMCs.
- ALP activity was significantly higher in SHR aortic SMCs, indicating enhanced calcification.
Conclusions:
- Hypertension promotes vascular calcification in aortic SMCs.
- The Msx2-Osterix signaling pathway appears to mediate this increased calcification in hypertensive rats.
Abstract:
Although hypertension and vascular calcification are well established as important risk factors for several cardiovascular diseases, the relationship between them is unknown. Here, we investigated whether hypertension is relevant to vascular calcification by examining aortic smooth muscle cells (SMCs) isolated from the descending thoracic aortas of Wistar Kyoto rats (WKY) as normotensive rats and spontaneously hypertensive rats (SHR), a typical rat model of hypertension. Cells were cultured in DMEM containing 10% FBS for 6 days after reaching confluence. Von Kossa staining revealed that the positively stained calcified area of aortic SMCs from SHR increased rapidly compared to that from WKY. The gene expressions of calcification-regulating proteins including msh homeobox homolog 2, Osterix (a master transcription factor for osteogenesis), and alkaline phosphatase (ALP) (a marker of vascular calcification) were significantly increased in aortic SMCs from SHR compared to SMCs from WKY. On the other hand, Runx2, another osteogenic transcription factor, did not upregulate. Furthermore, we confirmed that ALP activity was strongly increased in aortic SMCs from SHR compared to SMCs from WKY. These results suggest that aortic SMCs from SHR tend to become easily calcified via an Msx2-Osterix signaling pathway.
