Characterization of small leucine-rich proteoglycans in aortic valves of patients with aortic valve stenosis

We previously reported aberrant glycosylation of lumican, one of small leucine-rich proteoglycans (SLRPs), in aortic valves in patients with aortic valve stenosis (AS). Extending the study, we here characterized other SLRPs of proline/arginine-rich end leucine-rich repeat protein (PRELP), decorin, and biglycan in AS valves. Specifically, thickened and calcified (AS-C) areas and apparently non-thickened and non-calcified (AS-N) areas of aortic valves were sampled in 8 patients with AS. Then amounts of three molecules with or without removal of N-glycosylation by PGNase were compared between the AS-C and AS-N areas. As a result, the amounts of PRELP with moderate and/or low amounts of N-glycosylation were found decreased in the AS-C areas compared to the AS-N areas. The amounts of decorin with both glycosaminoglycan (GAG) and N-linked oligosaccharides were decreased in the AS-C area compared to the AS-N area. Moreover, the amounts of biglycan with GAG and N-linked oligosaccharides were decreased, instead, the amounts of biglycan without GAG were increased in the AS-C areas compared to AS-N areas. These quantitative and qualitative changes of the three SLRPs detected here may be involved in the progression of AS changes of aortic valves.