Research Interests

The goal in my laboratory is primarily to foster regeneration of axons across and beyond the area of injury. This has been an objective since moving to Miami in 1989. To improve regeneration of axons after spinal cord injury, we are investigating increases in cyclic AMP levels, interference with proteoglycans (molecules that inhibit axonal growth), transplantation of Schwann cells and/or olfactory ensheathing glia, and genetic engineering of these cells before transplantation to improve their neurotrophic factor-secreting capability. We have also initiated a new microarray study to explore gene differences between neurons that are able to regrow onto a cellular bridge placed in the area of injury and those that do not grow onto the bridge. Because the reactions of the tissue to spinal cord injury are many and varied, I espouse the concept that a combination strategy will be necessary to adequately improve outcome after spinal cord injury.

A main contribution of my laboratory has been to introduce the novel use of a cellular (Schwann cell) bridge across a complete transection gap in the adult rat spinal cord. We have tried a number of combination strategies, and the spinal cord injured animal has improved. For example, when neurotrophins, brain-derived neurotrophic factor and neurotrophin-3, are introduced along with Schwann cell bridges, there are more regrowing fibers on the bridge and there is an increased variety of fibers on the bridge, including some from distant neuronal somata positioned in the brain stem. Fibers also exit the bridge after a combination strategy, such as the transplantation of olfactory ensheathing glia at either end of the Schwann cell bridge. This combination also led to long-distance axonal regeneration in the adult rat spinal cord. We also have tested combination strategies in a spinal cord contusion model. We have demonstrated that a combination strategy with either lesion model is consistently more effective than transplanting Schwann cells alone. Also, more recent studies have been initiated to assess transplanted Schwann cell survival, and how to improve it, and to investigate modes of presenting the Schwann cells in the spinal cord from a bioengineering perspective.  

Interview with Marc Buoniconti, President, The Miami Project to Cure Paralysis

Today I am going to share portions of a recent question and answer session with Dr. Mary Bartlett Bunge. As often happens when I get together with her, our discussions go on for a while so I am including only a portion here. In the near future, I will write up and share additional excerpts. Since joining our team in 1989 with her late husband and former scientific director, Richard P. Bunge, she has been a research superstar for The Miami Project. She has spent much of her career working with Schwann cells, and it is a discovery that she and Dr. Damien Pearse reported in 2004 that is the impetus for our application to the FDA for our first ever clinical trial involving Schwann cell transplantation.

MARC: We all know that you are a highly accomplished neuroscientist, but can you tell us what made you want to become a scientist in the first place?

Mary Bartlett Bunge, Ph.D.: When I was a young girl in Connecticut we lived in the woods and near a stream on which I rowed my little leaky rowboat. As I saw many tadpoles swimming around, I wondered how they developed and grew. When I was a little older I remember being in biology class and part of our exercise was to draw many types of one-celled animals (such as paramecia) and they enthralled me so much that I began to consider that biology would be more compelling than my strong artistic and fashion interests. Following high school I went to Simmons College in order to become a lab tech. But when I joined the summer program at Jackson Laboratories in Bar Harbor, ME, I worked with a man who one day placed rabbit heart tissue in culture. When I saw the tissue in the Petri dish still beating, it was a major moment for me that provided inspiration to go to graduate school. This sealed my career path, going to the University of Wisconsin and meeting my future husband, Richard, who introduced me to the nervous system. In one of my courses I saw images in an early electron microscope, and when I saw how beautiful they were I was hooked for good! I then used electron microscopy for my Ph.D. Thesis.

MARC: How did you end up at The Miami Project? At the time you were at a very prestigious institution and we were a fledgling organization struggling for credibility.

MBB: Dick believed in a quote by Goethe, “When the harbor feels safe, then it is time to leave”. So when he received a call about being interviewed for the job of scientific director at The Miami Project, we immediately thought that this might be a way in which we could utilize our extensive knowledge of Schwann cells to see how they could be helpful in spinal cord injury. We also thought that if we came here we could assemble a larger team to make better progress in looking at the role of Schwann cells in repairing the spinal cord.

MARC: It’s safe to say that Schwann cells have been central to your life’s work. When did you start working on them and why?

MBB: We learned about Schwann cells from Dr. Margaret Murray while at Columbia Presbyterian College of Physicians and Surgeons as postdocs. She was very famous for developing nerve tissue culture. After studying nervous tissue in culture, it became Richard’s vision to use a piece of human peripheral nerve to obtain Schwann cells which could be transplanted into the injury site of the same person, and thus avoid immune rejection. After the initial studies of Schwann cell transplantation into the spinal cord, we realized that we could enhance the positive results of Schwann cells by combining them with other strategies. This led to the 2004 discovery. I am a basic scientist but from the beginning I was always interested in how my work would be relevant to clinical conditions and always felt that the Schwann cell held great promise.

MARC: Just to switch things up a little bit, coming from a family of many talents, what do you like to do in your free time?

MBB: Not that I have a lot of free time, but I love to go to New York, and have “art days” with one of my sons, taking in museums and art galleries. In particular, glass sculpture is a passion of mine. Right in our back yard is the University of Miami’s Lowe Art Museum with the Myrna and Sheldon Palley Pavilion for Contemporary Glass and Studio Arts, which is just wonderful. I also love to see movies, listen to books on tape or CD (everyday while driving) and write poetry, particularly limericks. Just last week-end I participated in a 2-day intensive workshop presented by the MFA Creative Writing Program at UM. To keep active I like to walk, garden and attend Pilates classes.

MARC: Thank you Dr. Bunge for all your hard work and for dedicating your life to trying to solve the complex mystery of spinal cord injury. The Miami Project will expand on this interview with a more detailed and in-depth story in the near future.