ABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping early-career researchers promote themselves alongside their papers. Minwook Kim is first author on ‘ Synovial joint cavitation initiates with microcavities in interzone and is coupled to skeletal flexion and elongation in developing mouse embryo limbs’, published in BiO. He is a postdoc in the lab of Maurizio Pacifici at the Abramson Research Center in Philadelphia, USA investigating developmental biology, tissue engineering and regenerative medicine in the context of the synovial joint.
Minwook Kim
What is your scientific background and the general focus of your lab?
I studied mechanical engineering in college and bioengineering in graduate school. My graduate research focused on studying cartilage tissue engineering and in particular, developing engineering cartilage. I carried out these bioengineering studies under the guidance of Drs Nancy Pleshko, George Dodge and Robert Mauck. I wanted to broaden my knowledge in the fields of developmental biology and molecular genetics, aiming to become immersed in studies on mechanisms of embryonic synovial joint formation and growth. To fulfil these goals, I joined the laboratory of Dr Maurizio Pacifici at the Children's Hospital of Philadelphia as a postdoctoral fellow. My current research focuses on the formation of synovial joints and particularly understanding the mechanisms of joint cavitation and lineage commitment of synovia progenitor cells at a prospective joint site.
How would you explain the main findings of your paper to non-scientific family and friends?
The synovial joint space (for example, the knee joint) and the fluid that fills the joint are essential for joint function and lubrication, but their developmental biology remains largely obscure. In our paper, we discovered that joint cavitation initiates with the emergence of multiple discrete, micron-wide tissue discontinuities we term ‘microcavities’ in the joint-forming region. The microcavities were surrounded by cells and contained a sugar and protein content. We also found that the growing femur and tibia anlagen progressively flexed at the knee over time. Conditional deletion of hyaluronan synthase 2 (Has2), a producer of hyaluronic acid (HA), on joint-forming cells in the future joint region delayed the cavitation process. Our data reveal that cavitation is a stepwise process brought about by sequential action of microcavities, skeletal flexion and elongation, and HA accumulation.
What are the potential implications of these results for your field of research?
This study provides novel and unprecedented insights into mechanisms of synovial joint development and cavitation. Understanding the dynamics of HA metabolism in the regulation of joint formation and cavitation will continue to provide novel insights into the creation of superior therapeutic tools to treat degenerative joint diseases.
What has surprised you the most while conducting your research?
Our results demonstrate that joint cavitation is a stepwise and rapid process. Knee joint cavitation starts with formation of microcavities in the joint-forming region and evolves into a single, fluid-filled cavity within 6-12 hours. Conversely, digit joint cavitation starts and ends within 72-84 hours.
“Our results demonstrate that joint cavitation is a stepwise and rapid process.”
What, in your opinion, are some of the greatest achievements in your field and how has this influenced your research?
Dumortier et al. (2019) demonstrated that hydraulic fracturing of cell–cell contacts followed by contractility-directed coarsening of microlumens sets the first axis of symmetry of the mouse embryos. This study ascertained our idea regarding the initiation and progression of joint cavitation.
What changes do you think could improve the professional lives of early-career scientists?
Postdocs need a principal-investigator-independent travel grant to attend scientific meetings, particularly small group meetings such as the Gordon Research Conference. Meeting top scientists in the field and learning their new findings at these conferences will motivate young scientists and give them an opportunity for social and scientific networking.
What's next for you?
I am currently looking for a faculty position in an academic institution and working on my first R01 grant.
Minwook Kim's contact details: 3615 Civic Center Boulevard, Abramson Research Center, Suite 904, Philadelphia PA 19104, USA.
E-mail: [email protected]
