Speaker: Professor Kuang Sheng LEE (Oscar)
Institution: Department of Orthopaedic & Traumatology, Chinese University of Hong Kong
Hosted by: Professor Benzhong TANG
Abstract
Mesenchymal stem cells (MSCs) were first defined as a group of cells which were of self-renewal ability, were able to be culture-expanded for a prolonged period of time, and are able to differentiate into various lineages of connective progenies originated from embryonic mesoderm including bone, cartilage and adipose tissues. These cells were first isolated from bone marrow; subsequently, MSCs isolated from other sources such as liposuction fat, synovial tissues and trabecular bone have been reported by other investigators. Recently, it was reported that certain population of stem cells in human bone marrow, although low in frequency, were able to differentiate into cells and tissues originated from not only mesoderm, but also ectoderm.
In our laboratory, we have successfully isolated and culture-expanded MSCs from human bone marrow and umbilical cord blood using negative immuno-selection and limiting dilution methods. Surface phenotype of these cells was performed using flow cytometry and surface marker phenotype was characteristic of MSCs. These MSCs were able to differentiate into progenies originated from all three germ layers including osteoblasts, chondrocytes, adipocytes, neuroglial cells and hepatocytes. In vitro functionality of these differentiated progenies was also demonstrated. Particularly, MSC-differentiated hepatocytes have been shown to be able to secrete urea and uptake of low density lipoproteins is also noted in these MSC-differentiated hepatocytes.
There are various applications of MSCs in biomedical research both in vitro and in vivo. The in vitro model of MSC culture can serve as an excellent model to study the control of differentiation as well as the cell fate in each lineage. Novel genes and proteins that control differentiation can also be explored in this model. Besides, it can also be used for screening of new drugs and compounds. Most important of all, MSCs are indispensable in the study of cell therapy, tissue engineering and regenerative medicine.
Over the years, we have published more than one hundred peer-reviewed research articles to report our findings regarding the molecular mechanisms that govern the fate choice and differentiation, as well as the plasticity and applications of MSCs. In particular, our efforts made to elucidate how MSCs sense and respond to biophysical and mechanical stimuli have substantially contributed to the understanding of mechanobiology in MSCs.
In summary, it is foreseeable that in the near future, MSCs will revolutionize the treatment of a variety of diseases. Therefore, more efforts should be made to further elucidate the basic science of MSCs to accelerate their clinical translation from bench to bedside.
About the speaker
Professor Oscar Lee is an internationally renowned orthopaedic surgeon and stem cell scientist. He specializes in adult joint reconstruction and musculoskeletal tumour surgeries.
Over the years, Prof. Lee has been devoting to the development of cellular therapies for musculoskeletal diseases such as bone and soft tissue tumours and ageing-related conditions including osteoporosis, sarcopenia and frailty. In his early career, he has pioneered to successfully isolate mesenchymal stem cells (MSCs) not only from human bone marrow but also from human umbilical cord blood, and other different types of tissues. In addition, he has extensively studied the biology of osteogenesis and has discovered the hepatogenic potential of MSCs. Moreover, Prof. Lee has extensively studied how physical properties of the microenvironments, including three-dimensional spherical spatial boundary conditions, substrate stiffness, and mechanical forces generated by fluid shear stress, contribute to the regulation of osteogenesis in MSCs. Prof. Lee is also developing new robotic assisted orthopaedic surgical techniques to further increase surgical precision, and AI-based platform technologies to facilitate imaging and histopathological diagnosis further improve patient outcome. Prof. Lee has published more than 120 peer-reviewed articles in leading journals such as Cell, Nature Cell Biology, Gastroenterology, Hepatology, Nucleic Acid Research, PNAS, Blood and Biomaterials. Prof. Lee is the Associate Editor of Stem Cell Research &Therapy since 2015, and the Associate Editor of Cytotherapy since 2018. He has also served as editorial board member and reviewer for numerous journals related to orthopaedics, stem cell research and regenerative medicine. Prof. Lee is the Past President of Taiwan Orthopedic Research Society (2014-2016) and is Fellow of International Combined Orthopedic Research Society (ICORS). Prof. Lee has been elected President of Taiwan Association of Artificial Intelligence Research and Development in Biomedicine in 2018, and has been elected Vice President of International Society for Cell & Gene Therapy (ISCT) for 2019 to 2021.
In the Department of Orthopaedic & Traumatology, Prof. Lee runs the Laboratory for Intelligent Orthopaedic Bio-Engineering Research. He is also the Theme Convener of "Clinical Trial and Precision Medicine" Programme at the Institute for Tissue Engineering and Regenerative Medicine at the Chinese University of Hong Kong.