Jean-Pierre Rwigema: Pioneering Innovator in Stem Cell Research at the USC School of Dentistry

June 27, 2008

Jean-Pierre Rwigema was born in Rwanda with his three brothers and sister. After surviving the war and genocide that ravaged Rwanda in 1994, he went to study in South Africa where he finished high school at Glen High in Pretoria. He studied electrical engineering at the leading South African University of the Witwatersrand (Johannesburg) and later transferred to La Roche College in Pittsburgh where he majored in computer science and mathematics. He is now a student at the University of Southern California Dental School.

USC Stevens asked Jean-Pierre for details about himself and his research. This is what he told us:

Help us understand what you are up to (Describe your work / research):
hTERT-IMMORTALIZED HUMAN FETAL BONE MARROW MESENCHYMAL STEM CELLS EXPRESS STEM CELL MARKERS AND ARE CAPABLE OF OSTEOGENIC DIFFERENTIATION.

Mesenchymal stem cells (MSC) are non-hematopoietic stromal cells capable of differentiation into osteoblasts, chondrocytes, myocytes, adipocytes, and a variety of other cell types.  They contribute to regeneration of mesenchymal tissues such as bone, cartilage, muscle, ligament, tendon and adipose tissue.  

MSCs are characterized by expression of surface markers including CD29, CD10, CD44 and STRO-1, and are negative for hematopoietic markers CD34, CD45 and CD14.  We used human telomerase reverse transcriptase (hTERT) to immortalize a human fetal MSC (hfMSC.hTERT).  In the present study, we characterized the properties of the hfMSC.hTERT cell line with regard to expression of MSC markers and their ability to undergo osteogenic differentiation.  

The hfMSC.hTERT cells displayed a normal karyotype, and were analyzed for MSC markers by flow cytometry.  The cells were induced to osteogenic differentiation for a period of 4 weeks in osteogenic medium containing dexamethasone.  Control cultures were grown under non-osteogenic conditions.  Progressive morphologic differentiation was observed after 1 week in culture.  RT-PCR was used to screen cells for expression of collagen 1, osteocalcin, osteopontin, Runx2, alkaline phosphatase and Twist genes, which are critical in the process of osteogenic differentiation.  Alizarin Red staining was performed on treated and untreated cells to identify calcium deposits in the differentiated hfMSC.hTERT cells.  Morphological changes of hfMSC.hTERT have been observed during differentiation under osteogenic conditions.  Expression of collagen 1, osteocalcin, osteopontin, Runx2, alkaline phosphatase and Twist genes was detected both in non-differentiated and differentiated hfMSC.hTERT cells.  Alizarin Red staining revealed calcium deposits in the differentiated hfMSC.hTERT cells showing minearlization during osteogenic differentiation.  The hfMSC.hTERT immortalized cell line will be useful in further studies of stem cell biology and osteogenesis. 

What drives you to continue pursuing this area of study?
I have an obsession for wanting to know mysteries.

Describe how your work might impact people's lives, now and in the future. (What's the potential societal impact?)                                                                                                     
There are many ways in which human stem cells can be used in basic and in clinical research. Studies of human embryonic stemcells can yield information about the complex events that occur during human development. Some of the most serious medical conditions, such as cancer and birth defects, are due to abnormal cell division and differentiation. A better understanding of the genetic and molecular controls of these processes can help us gather more information about how such diseases arise and suggest new strategies for therapy. Furthermore, it is important to understand the signals that turn specific genes on and off to influence the differentiation of the stem cell.

Human stem cells can also be used to test new drugs. Cancer cell lines, for example, are used to screen potential anti-tumor drugs. Perhaps the most important potential application of human stem cells is the generation of cells and tissues that could be used for cell-based therapies. Today, donated organs and tissues are often used to replace destroyed tissue, but the need for transplantable tissues and organs far outweighs the available supply. Stem cells can be induced to differentiate into specific cell types in hope to treat diseases such as Parkinson's and Alzheimer's diseases, spinal cord injury, stroke, burns, heart disease, diabetes, osteoarthritis, and rheumatoid arthritis. One day, it may become possible to generate healthy heart muscle cells in the laboratory and then transplant those cells into patients with chronic heart disease. Recent studies in vitro indicate that it may be possible to direct the differentiation of embryonic stem cells or adult bone marrow cells into heart muscle cells.

How did you come up with the idea?
I always wanted to know more about stem cells, what they are, what they do and how we can use them to benefit our health.

Has anyone ever doubted that your idea could work? (Please elaborate.)
It is not that anyone has doubted that this scientific idea might not work but I think it is important to know why it wouldn't work or why it might work in unpredictable ways so that we can further our understanding.

What is the one innovation you can't live without?
Electricity

Any tips for aspiring innovators?
Share the knowledge

What is the most fun you've ever had?
Going on a hunting Safari in Rwanda

Three favorite things about LA:
The weather, there is always something to do, and the beaches