TY - JOUR
T1 - Osteopontin is proteolytically processed by matrix metalloproteinase 9
AU - Lindsey, Merry L.
AU - Zouein, Fouad A.
AU - Tian, Yuan
AU - Iyer, Rugmani Padmanabhan
AU - de Castro Brás, Lisandra E.
N1 - Publisher Copyright:
© 2015, National Research Council of Canada. All rights reserved.
PY - 2015/1/19
Y1 - 2015/1/19
N2 - Osteopontin is robustly upregulated following myocardial infarction (MI), which suggests that it has an important role in post-MI remodeling of the left ventricle (LV). Osteopontin deletion results in increased LV dilation and worsened cardiac function. Thus, osteopontin exerts protective effects post-MI, but the mechanisms have yet to be defined. Matrix metalloproteinases (MMPs) regulate LV remodeling post-MI, and osteopontin is a known substrate for MMP-2, -3, -7, and -9, although the cleavage sites have not been mapped. Osteopontin-derived peptides can exert distinct biological functions that may depend on their cleavage sites. We mapped the MMP-9 cleavage sites via LC-MS/MS analysis using label-free and N-terminal labeling methods, and compared them with those of MMP-2, -3, and -7. Each MMP yielded a unique cleavage profile with few overlapping cleavage sites. Using synthetic peptides, we validated 3 sites for MMP-9 cleavage at amino acid positions 151–152, 193–194, and 195–196. Four peptides were synthesized based on the upstream- and downstream-generated fragments and were tested for biological activity in isolated cardiac fibroblasts. Two peptides increased cardiac fibroblast migration rates post-wounding (p < 0.05 compared with the negative control). Our study highlights the importance of osteopontin processing, and confirms that different cleavage sites generate osteopontin peptides with distinct biological functions.
AB - Osteopontin is robustly upregulated following myocardial infarction (MI), which suggests that it has an important role in post-MI remodeling of the left ventricle (LV). Osteopontin deletion results in increased LV dilation and worsened cardiac function. Thus, osteopontin exerts protective effects post-MI, but the mechanisms have yet to be defined. Matrix metalloproteinases (MMPs) regulate LV remodeling post-MI, and osteopontin is a known substrate for MMP-2, -3, -7, and -9, although the cleavage sites have not been mapped. Osteopontin-derived peptides can exert distinct biological functions that may depend on their cleavage sites. We mapped the MMP-9 cleavage sites via LC-MS/MS analysis using label-free and N-terminal labeling methods, and compared them with those of MMP-2, -3, and -7. Each MMP yielded a unique cleavage profile with few overlapping cleavage sites. Using synthetic peptides, we validated 3 sites for MMP-9 cleavage at amino acid positions 151–152, 193–194, and 195–196. Four peptides were synthesized based on the upstream- and downstream-generated fragments and were tested for biological activity in isolated cardiac fibroblasts. Two peptides increased cardiac fibroblast migration rates post-wounding (p < 0.05 compared with the negative control). Our study highlights the importance of osteopontin processing, and confirms that different cleavage sites generate osteopontin peptides with distinct biological functions.
KW - Cardiac
KW - Cleavage sites
KW - Fibroblasts
KW - MMP-9
KW - Mass spectrometry
KW - Matrix metalloproteinases
KW - Myocardial infarction
KW - Osteopontin
KW - Peptides
KW - Proteomics
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U2 - 10.1139/cjpp-2015-0019
DO - 10.1139/cjpp-2015-0019
M3 - Article
C2 - 26176332
AN - SCOPUS:84943526580
VL - 93
SP - 879
EP - 886
JO - Canadian Journal of Physiology and Pharmacology
JF - Canadian Journal of Physiology and Pharmacology
SN - 0008-4212
IS - 10
ER -