Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help needed understanding results of a study

  1. Feb 19, 2016 #1
    -Aggrecan is an abundant component of cartilage within the growth plate as well as the articular cartilage of joints
    -ADAMTS4 and ADAMTS5 are aggrecanases that cleave aggrecan
    -Analysis of the growth plates of mice were performed by immunostaining the growth plates with an antibody against neo-epitope of aggrecan (GI-TEGE) which is generated following cleavage by aggrecanases
    The results showed:

    a) Wild-type mice: significant staining

    b) ADAMTS4 -/- mice: negligible staining

    c) ADAMTS5 -/- mice: similar staining to that of wild-type mice

    Conclusion: ADAMTS4 is the sole aggrecanase responsible for aggrecan cleavage at this anatomical location

    My question is that if GI-TEGE is generated following cleavage shouldn't ADAMTS4 be showing the most staining since it is responsible for cleaving at this site? Why is there the least staining at ADAMTS4 ? Am I missing something?
    Thank you in advanced!
    *image and data are taken from paper titled: deletion of active ADAMTS5 prevents cartilage degradation in a murine model of osteoarthritis by Glasson et al. 2005

    Attached Files:

  2. jcsd
  3. Feb 20, 2016 #2


    User Avatar
    Science Advisor
    2017 Award

    ADAMTS4 -/- mice have both copies of the ADAMTS4 gene knocked out. Because these mice lack ADAMTS4, they are unable to generate GI-TEGE and show no staining in the figure. When ADAMTS5 is knocked out (in the ADAMTS5 -/- mice), there is no change to the staining. Because mice lacking ADAMTS5 are capable of producing wild-type levels of GI-TEGE, they conclude that ADAMTS5 is not required for aggrecan cleavage at the location they stained.
  4. Feb 21, 2016 #3
    thank you!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook