PMID- 17724206 OWN - NLM STAT- MEDLINE DCOM- 20071011 LR - 20220129 IS - 0146-0404 (Print) IS - 0146-0404 (Linking) VI - 48 IP - 9 DP - 2007 Sep TI - MMP and TIMP expression in quiescent, dividing, and differentiating human lens cells. PG - 4192-9 AB - PURPOSE: Matrix metalloproteinases (MMPs) and the tissue inhibitors of the MMPs (TIMPs) have been implicated in lens differentiation, growth, remodeling, and cataract. Hence, a gene expression analysis was undertaken in epithelial and fiber cells dissected from clear human donor lenses. METHODS: The human lens was dissected into three regions: anterior epithelial, equatorial, and fiber cells. Primary lens cell cultures were also analyzed. cDNA was generated by reverse transcription of the mRNA portion of the total RNA isolated from each sample. Gene expression data were generated using quantitative real-time reverse transcription PCR. Data were analyzed in terms of cycle threshold number (C(T)) and were normalized to endogenous 18S expression. Western blot analyses were carried out to confirm the presence of two critical MMPs. RESULTS: Anterior and equatorial samples were uncontaminated by fiber cells because they showed high expression of alpha-crystallin genes but low expression of beta- and gamma-crystallins. The fibers had high expression of these genes and of MIP. MMP genes were expressed at uniformly low levels in the native tissues except for MMP-14 and -15 (MT1- and MT2-MMP, respectively). In fact, MT1-MMP declined in expression from the anterior epithelium to fibers, whereas MT2-MMP increased. The presence of MT1 and MT2-MMP proforms and faster migrating bands, indicating processed or activated forms, was confirmed at the protein level. TIMP genes were uniformly highly expressed in native tissues, with TIMP-3 having the highest expression in the epithelial tissues and TIMP-2 in the fibers. MMP expression was generally elevated in both sets of cultured cells, including MMP-2 and -9. TIMP genes were also relatively highly expressed in the cultured cells. CONCLUSIONS: MMP expression is generally well regulated in native tissues, with relatively low expression of MMPs and high expression of TIMPs. Membrane-type MMPs (MT1 and 2-MMPs) were the most highly expressed; this is important in a tissue with relatively high membrane content but low extracellular space. The striking reciprocal patterns of expression of MT1-MMP and MT2-MMP indicate that these enzymes are of particular significance in lens function. FAU - Hodgkinson, Lisa M AU - Hodgkinson LM AD - School of Biological Sciences, University of East Anglia, Norwich, United Kingdom. l.hodgkinson@uea.ac.uk FAU - Duncan, George AU - Duncan G FAU - Wang, Lixin AU - Wang L FAU - Pennington, Caroline J AU - Pennington CJ FAU - Edwards, Dylan R AU - Edwards DR FAU - Wormstone, I Michael AU - Wormstone IM LA - eng GR - G0100250/MRC_/Medical Research Council/United Kingdom PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - United States TA - Invest Ophthalmol Vis Sci JT - Investigative ophthalmology & visual science JID - 7703701 RN - 0 (RNA, Messenger) RN - 0 (Tissue Inhibitor of Metalloproteinases) RN - EC 3.4.24.- (Matrix Metalloproteinases) SB - IM MH - Aged MH - Blotting, Western MH - Cell Differentiation/genetics MH - Cell Division/genetics MH - Cells, Cultured MH - Gene Expression/*physiology MH - Humans MH - Lens, Crystalline/*cytology/*metabolism MH - Matrix Metalloproteinases/*genetics MH - Middle Aged MH - RNA, Messenger/metabolism MH - Reverse Transcriptase Polymerase Chain Reaction MH - Tissue Donors MH - Tissue Inhibitor of Metalloproteinases/*genetics EDAT- 2007/08/29 09:00 MHDA- 2007/10/12 09:00 CRDT- 2007/08/29 09:00 PHST- 2007/08/29 09:00 [pubmed] PHST- 2007/10/12 09:00 [medline] PHST- 2007/08/29 09:00 [entrez] AID - 48/9/4192 [pii] AID - 10.1167/iovs.06-1371 [doi] PST - ppublish SO - Invest Ophthalmol Vis Sci. 2007 Sep;48(9):4192-9. doi: 10.1167/iovs.06-1371.