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3 Responses

  1. kathy
    kathy July 5, 2011 at 2:00 pm | | Reply

    Thanks for posting on my favorite topic. There are so many directions that islet cell transplantation research is moving. This direction offers both an alternative site for the islets and a means of learning more about their behavior in vivo.

  2. Meri
    Meri July 5, 2011 at 8:58 pm | | Reply

    I appreciate the work they do too! Fascinating!

  3. Dr. Midhat Abdulreda
    Dr. Midhat Abdulreda July 11, 2011 at 10:24 am | | Reply

    Yes the eye model is currently an experimental tool, a highly versatile one that is, that is being used to investigate many aspects of islet physiology and immunobiology in vivo. We have been able to address many questions that could not be addressed using conventional in vitro studies.

    While transplantation into the anterior chamber of the eye has provided us with great advantages over other transplantation sites by enabling longitudinal and non-invasive in vivo imaging of the very same individual pancreatic islets with cellular resolution, like other experimental transplantation sites the eye model will fall short of the real situation within the pancreas.

    Nonetheless, while currently practiced in the clinic islet transplantation into the liver is still considered an experimental approach that has its limitations as well (e.g., IBMIR), which is the reason why many funding agencies including the NIH have had active funding opportunities to look for alternative sites….

    With that said, the eye may offer a viable transplantation site in the future for a variety of reasons including: 1) easy access for implantation, 2) possible local immunosuppression and minimization/elimination of systemic side effects, 3) easy non-invasive observation/imaging of islets to assess islet function and follow up on islet mass, 4) immune privilege properties and possible tolerance induction (great advantage given the high interest in immune tolerance), 5) possibly less islet required for transplantation given the non-enzymatic environment.

    Of course we still need to address many remaining issues regarding the eye model including possible effects on eye sight. As a first step in that direction, we have already moved these studies into non-human primates in Miami and we recently provided a proof-of-principle of the feasibility of islet transplantation into the eye of large mammals (see our study in Diabetologia 2011 May;54(5):1121-6. Epub 2011 Mar 1, http://www.ncbi.nlm.nih.gov/pubmed/21360190). We have also recently expanded these studies to South Korea where we hope to address many of the remaining issues before considering translation into the clinic.

    I believe that I stated it clearly in the UTM interview by saying “We believe the eye may one day be used…” because this is what we believe and hope to achieve in the future.

    Regards,
    Midhat Abdulreda, M.S, Ph.D
    Diabetes Research Institute (DRI)
    University of Miami Miller School of Medicine

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