title: Two Distinct Isoforms of Matrix Metalloproteinase-2 Are Associated with Human Delayed Kidney Graft Function.
abstract: Delayed graft function (DGF) is a frequent complication of renal transplantation, particularly in the setting of transplantation of kidneys derived from deceased donors and expanded-criteria donors. DGF results from tubular epithelial cell injury and has immediate and long term consequences. These include requirement for post-transplantation dialysis, increased incidence of acute rejection, and poorer long-term outcomes. DGF represents one of the clearest clinical examples of renal acute ischemia/reperfusion injury. Experimental studies have demonstrated that ischemia/reperfusion injury induces the synthesis of the full length secreted isoform of matrix metalloproteinase-2 (FL-MMP-2), as well as an intracellular N-terminal truncated MMP-2 isoform (NTT-MMP-2) that initiates an innate immune response. We hypothesized that the two MMP-2 isoforms mediate tubular epithelial cell injury in DGF. Archival renal biopsy sections from 10 protocol biopsy controls and 41 cases with a clinical diagnosis of DGF were analyzed for the extent of tubular injury, expression of the FL-MMP-2 and NTT-MMP-2 isoforms by immunohistochemistry (IHC), in situ hybridization, and qPCR to determine isoform abundance. Differences in transcript abundance were related to tubular injury score. Markers of MMP-2-mediated injury included TUNEL staining and assessment of peritubular capillary density. There was a clear relationship between tubular epithelial cell expression of both FL-MMP-2 and NTT-MMP-2 IHC with the extent of tubular injury. The MMP-2 isoforms were detected in the same tubular segments and were present at sites of tubular injury. qPCR demonstrated highly significant increases in both the FL-MMP-2 and NTT-MMP-2 transcripts. Statistical analysis revealed highly significant associations between FL-MMP-2 and NTT-MMP-2 transcript abundance and the extent of tubular injury, with NTT-MMP-2 having the strongest association. We conclude that two distinct MMP-2 isoforms are associated with tubular injury in DGF and offer novel therapeutic targets for the prevention of this disorder.
authors.affiliation: Department of Medicine, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Shaynah
authors.initials: S
authors.lastname: Wanga
authors.affiliation: Department of Medicine, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Carla S
authors.initials: CS
authors.lastname: Ceron
authors.affiliation: Department of Medicine, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Delgado
authors.affiliation: Department of Medicine, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Joshi
authors.affiliation: Department of Surgery, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Spaulding
authors.affiliation: Department of Surgery, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Joy P
authors.initials: JP
authors.lastname: Walker
authors.affiliation: Department of Medicine, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Sangheon
authors.initials: S
authors.lastname: Song
authors.affiliation: Department of Pathology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Jean L
authors.initials: JL
authors.lastname: Olson
authors.affiliation: Department of Medicine, San Francisco Department of Veterans Affairs Medical Center/University of California San Francisco, San Francisco, California, United States of America.
authors.forename: David H
authors.initials: DH
authors.lastname: Lovett
mesh_terms: D002196:Capillaries / Q000378:metabolism; D051799:Delayed Graft Function / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D016030:Kidney Transplantation; D007684:Kidney Tubules / Q000098:blood supply / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D020778:Matrix Metalloproteinase 2