title: Analysis of Gene Expression and Ultrastructure of Stifle Menisci from Juvenile and Adult Pigs.
abstract: The origin of the age-associated degenerative processes in meniscal tissue is poorly understood and may be related to an imbalance of anabolic and catabolic metabolism. The aim of the current study was to compare medial menisci isolated from juvenile pigs and degenerated medial menisci from adult pigs in terms of gene expression profile and ultrastructure. Medial menisci were isolated from the knee joints of juvenile and adult pigs (n = 8 for each group). Degeneration was determined histologically according to a scoring system. In addition, the gene expression profiles of 14 genes encoding extracellular matrix proteins, catabolic matrix metalloproteinases and mediators of inflammation were analyzed. Changes in the ultrastructure of the collagen network of the meniscal tissue were analyzed by using transmission electron microscopy. The histologic analysis of menisci showed significantly higher grade of degeneration in tissue isolated from adult porcine knee joints compared with menisci isolated from juvenile knee joints. In particular, destruction of the collagen network was greater in adult menisci than in juvenile menisci. Degenerated menisci showed significantly decreased gene expression of COL1A1 and increased expression of MMP2, MMP13, and IL8. The menisci from adult porcine knee joints can serve as a model for meniscal degeneration. Degenerative changes were manifested as differences in histopathology, gene expression and ultrastructure of collagen network.
authors.affiliation: Department of Experimental Orthopaedics, Trauma Surgery and Orthopaedic Surgery, BG Trauma Centre Ludwigshafen, Ludwigshafen, Germany. michael.kreinest@bgu-ludwigshafen.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Kreinest
authors.affiliation: Department of Experimental Orthopaedics, BG Trauma Centre Ludwigshafen, Ludwigshafen, Germany.
authors.forename: Gregor
authors.initials: G
authors.lastname: Reisig
authors.affiliation: Department of Pathology, University Medical Centre Göttingen, Göttingen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Ströbel
authors.affiliation: Department of Experimental Orthopaedics, BG Trauma Centre Ludwigshafen, Ludwigshafen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fickert
authors.affiliation: Department of Medical Statistics and Biometry, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Brade
authors.affiliation: Department of Anatomy, University of Duisburg-Essen, Essen, Germany.
authors.forename: Gunther
authors.initials: G
authors.lastname: Wennemuth
authors.affiliation: Department of Molecular Cell Biology, University Medical Centre Homburg, Saarland University, Homburg-Saar, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Lipp
authors.affiliation: Department of Experimental Orthopaedics, BG Trauma Centre Ludwigshafen, Ludwigshafen, Germany.
authors.forename: Markus L
authors.initials: ML
authors.lastname: Schwarz
mesh_terms: D000367:Age Factors; D000818:Animals; D001706:Biopsy; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D018836:Inflammation Mediators / Q000378:metabolism; D007719:Knee Joint / Q000378:metabolism* / Q000648:ultrastructure*; D008297:Male; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism; D008592:Menisci, Tibial / Q000378:metabolism* / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D034421:Sus scrofa
chemical_list: D016326:Extracellular Matrix Proteins; D018836:Inflammation Mediators; D020782:Matrix Metalloproteinases