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Updated: Jun 15, 2026
Quantitative Analysis and Characterization of Atherosclerotic Lesions in the Murine Aortic Sinus
Published on: December 8, 2013
Analysis of the polycystins in aortic vascular smooth muscle cells
Qi Qian1, Ming Li, Yiqiang Cai
1Division of Nephrology, Mayo Clinic, Rochester, Minnesota 55905, USA. Qian.qi@mayo.edu
Insights
Cardiovascular disease is the main cause of death in autosomal dominant polycystic kidney disease (ADPKD). This study reveals polycystins
Area of Science:
- Vascular Biology
- Nephrology
- Cell Biology
Background:
- Cardiovascular complications are the primary cause of mortality in autosomal dominant polycystic kidney disease (ADPKD).
- The specific mechanisms underlying these cardiovascular manifestations in ADPKD remain largely uncharacterized.
- Polycystins, proteins implicated in ADPKD, are investigated for their role in vascular smooth muscle cells.
Purpose of the Study:
- To characterize the expression and localization of polycystin-1 and polycystin-2 in vascular smooth muscle cells.
- To elucidate the in vivo interaction between polycystin-1 and polycystin-2.
- To determine the subcellular localization of polycystins and their potential role in vascular function.
Main Methods:
- Immunoprecipitation to assess protein interactions.
- Glycosidase treatment and cell surface biotinylation to identify cell surface proteins.
- Immunofluorescence microscopy for protein localization.
- Immuno-gold electron microscopy for high-resolution subcellular localization.
Main Results:
- Polycystin-1 expression is developmentally regulated, while polycystin-2 levels are more constant.
- Polycystin-1 and polycystin-2 interact in vivo.
- Polycystin-1, but not polycystin-2, is found on the plasma membrane.
- Both polycystins are predominantly cytoplasmic but also localize to the sarcoplasmic reticulum and dense plaques, with polycystin-1 also near the cell surface.
Conclusions:
- The polycystins play a significant role in the development, maintenance, and function of arterial organization.
- These findings provide insights into the pathogenesis of the vascular phenotype observed in ADPKD.
- Further research into polycystin function may reveal therapeutic targets for ADPKD-related cardiovascular complications.
Abstract:
The leading cause of death in autosomal dominant polycystic kidney disease (ADPKD) is cardiovascular. However, little is known about the pathogenesis of these manifestations. The present study was undertaken to characterize the ADPKD proteins, the polycystins, in vascular smooth muscle cells. It was demonstrated that the expression of polycystin-1 is developmentally regulated, whereas polycystin-2 has a more constant level of expression. A polycystin-1 subpopulation was immunoprecipitated by polycystin-2, indicating an in vivo interaction of these two proteins. Analysis with glycosidase and cell surface biotinylation indicates that some polycystin-1 products, but not polycystin-2, are located on the plasma membrane. Immunofluorescence showed that most of the polycystin-1 and polycystin-2 was cytoplasmic but that persistent polycystin-1 staining was located in proximity to the cell surface after a Triton-X extraction, whereas no clear surface localization of polycystin-2 was detected. Immuno-gold electron microscopy revealed that polycystin-1 was localized at the plasma membrane and sarcoplasmic reticulum, whereas polycystin-2 was mainly located in the sarcoplasmic reticulum. Both polycystins were found to be associated with dense plaques. These observations are consistent with an important role of the polycystins in the development, maintenance, and function of the myoelastic arterial organization and with the vascular phenotype associated with ADPKD.
