Involvement of matrix metalloproteinases and tenascin-C in elastin calcification.
Elastin degeneration and calcification occur in many cardiovascular diseases, including medial arterial elastocalcinosis, atherosclerosis, and bioprosthetic heart valve mineralization. In the present study, we tested the hypothesis that the onset and progression of elastin-oriented calcification is associated with matrix remodeling and elastin degradation events. We studied whether aluminum ions inhibit elastin calcification by reducing elastin degradation and altering remodeling events. Subdermal implantation of pure elastin in juvenile rats resulted in a time-dependent calcification of elastin, reaching high levels 21 days after implantation. In situ hybridization showed that elastin calcification was associated with an up-regulation of matrix metalloproteinase (MMP) mRNA expression, specifically MMP-9 and MMP-2. Gelatin zymography demonstrated increased MMP-9 and MMP-2 enzyme activities in early stages of elastin calcification. Calcified elastin displayed a time-dependent pattern of tenascin-C (TN-C) and alkaline phosphatase (AP) expression. Pretreatment of pure elastin with aluminum ions prior to implantation resulted in complete inhibition of elastin calcification. Aluminum ion binding to elastin was found to protect elastin against MMP-mediated degradation in vitro. Noncalcified, explanted aluminum-pretreated elastin exhibited reduced activities of MMPs. TN-C expression in elastin implants exhibited a time-dependent pattern that was also affected by pretreatment of elastin with aluminum ions. In conclusion, elastin calcification is accompanied by matrix remodeling events, and the efficacy of aluminum pretreatment in inhibiting elastin calcification may be related in part to its effects on elastin remodeling.
Bailey
Michael
M
501-1 Rhodes Research Center, Department of Bioengineering, Clemson University, Clemson, SC 29634, USA.
Pillarisetti
Swadeep
S
Jones
Peter
P
Xiao
Hui
H
Simionescu
Dan
D
Vyavahare
Narendra
N
D000469:Alkaline Phosphatase / Q000378:metabolism; D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000494:pharmacology; D000818:Animals; D001252:Astringents / Q000494:pharmacology; D015153:Blotting, Western; D002114:Calcinosis / Q000139:chemically induced / Q000503:physiopathology*; D002712:Chlorides / Q000494:pharmacology; D004195:Disease Models, Animal; D004549:Elastin / Q000187:drug effects / Q000378:metabolism* / Q000494:pharmacology; D017403:In Situ Hybridization; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000187:drug effects / Q000378:metabolism / Q000494:pharmacology; D020780:Matrix Metalloproteinase 9 / Q000187:drug effects / Q000378:metabolism / Q000494:pharmacology; D020782:Matrix Metalloproteinases / Q000187:drug effects / Q000378:metabolism* / Q000494:pharmacology; D010196:Pancreatic Elastase / Q000378:metabolism / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D019063:Tenascin / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D017607:Aluminum Compounds; D001252:Astringents; D002712:Chlorides; D012333:RNA, Messenger; D019063:Tenascin; D000077410:Aluminum Chloride; D004549:Elastin; D000469:Alkaline Phosphatase; D010196:Pancreatic Elastase; D020782:Matrix Metalloproteinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9