title: Interleukin-1 beta influences on lysyl oxidases and matrix metalloproteinases profile of injured anterior cruciate ligament and medial collateral ligament fibroblasts.
abstract: OBJECTIVE
  The anterior cruciate ligament (ACL) is known to have a poor healing ability, especially in comparison with the medial collateral ligament (MCL) which can heal relatively well. Interleukin-1beta (IL-1β) is considered to be an important chemical mediator in the acute inflammatory phase of ligament injury. The role of IL-1β-induced expressions of lysyl oxidases (LOXs) and matrix metalloproteinases (MMPs), which respectively facilitate extracellular matrix (ECM) repair and degradation, is poorly understood. In this study, we aim to determine the intrinsic differences between ACL and MCL by characterising the differential expressions of LOXs and MMPs in response to IL-1β in the injury process.
  
  
  METHODS
  Semi-quantitative polymerase chain reaction (PCR), quantitative real-time PCR, Western blot, and zymography were performed.
  
  
  RESULTS
  We detected high expressions of IL-1β-induced LOXs in normal ACL and MCL. Then, we found IL-1β induced injured MCL to express more LOXs than injured ACL (up to 2.85-fold in LOX, 2.58-fold in LOXL-1, 1.89-fold in LOXL-2, 2.46-fold in LOXL-3 and 2.18-fold in LOXL-4). Meanwhile, we found IL-1β induced injured ACL to express more MMPs than injured MCL (up to 1.72-fold in MMP-1, 1.95-fold in MMP-2, 2.05-fold in MMP-3 and 2.3-fold in MMP-12). The further protein results coincided with gene expressions above.
  
  
  CONCLUSIONS
  Lower expressions of LOXs and higher expressions of MMPs might help to explain the poor healing ability of ACL.
authors.affiliation: 111 Project Laboratory of Biomechanics and Tissue Repair, Bioengineering College, Chongqing University, Chongqing, 400044, People's Republic of China. wxxjj_2001@163.com
authors.forename: Jing
authors.initials: J
authors.lastname: Xie
authors.forename: Chunli
authors.initials: C
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Yin
authors.forename: ChunMing
authors.initials: C
authors.lastname: Xu
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Kuo-Li Paul
authors.initials: KL
authors.lastname: Sung
mesh_terms: D016118:Anterior Cruciate Ligament / Q000378:metabolism*; D000070598:Anterior Cruciate Ligament Injuries; D002478:Cells, Cultured; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism*; D020782:Matrix Metalloproteinases / Q000096:biosynthesis*; D017888:Medial Collateral Ligament, Knee / Q000293:injuries / Q000378:metabolism*; D008249:Protein-Lysine 6-Oxidase / Q000096:biosynthesis*; D014945:Wound Healing / Q000502:physiology*
chemical_list: D053583:Interleukin-1beta; D008249:Protein-Lysine 6-Oxidase; D020782:Matrix Metalloproteinases