“How do you mend a broken heart?” was the topic of one of our recent Stem Cellar blogs highlighting a stellar CIRM-funded publication on the regenerative abilities of the protein FSTL1 following heart injury. One of the master-minds behind this study is co-first author Ke Wei. Ke is a postdoc in Dr. Mark Mercola’s lab at the Sanford Burnham Prebys Medical Discovery Institute located in balmy southern California. He also happens to be one of our prized CIRM scholars.
Cross sections of a healthy (control) or injured mouse heart. Injured hearts treated with patches containing FSTL1 show the most recovery of healthy heart tissue (red). Image adapted from Wei et al. 2015)
Upon hearing of Ke’s important and exciting accomplishments in the field of regenerative medicine for heart disease, we called him up to learn more about his scientific accomplishments and aspirations.
Q: Tell us about your research background and how you got into this field?
KW: I went to UCLA for my graduate school PhD, and I studied under Dr. Fabian Chen focusing on heart development. At that time, I mainly worked on very early heart development and other tissues like smooth muscle cells. For my graduate thesis work, I found that particular genes were important for smooth muscle development.
So I was trained as a heart developmental biologist, but after my PhD, I came to the Burnham Institute and I joined two labs: Dr. Mark Mercola and Dr. Pilar Ruiz-Lozano. They co-mentored me for the first couple of years of my postdoc. Mark is interested in using stem cells and high throughput screens to identify pharmaceutical compounds for inducing heart regeneration and treating heart diseases. Pilar is interested in the epicardium, the outer layer of the heart, which is known to play important roles during heart development. When I joined their labs, they had combined forces to study how the epicardium affects heart development and heart diseases.
In their labs, I used my developmental biologist background to combine in vitro stem cells based screening studies (Mark) and in vivo mouse embryonic heart development studies (Pilar) to dissect the function of the epicardium on heart development and disease.
Q: Tell us about your experience as a CIRM scholar and what you were able to accomplish.
KW: My two years of CIRM fellowship were separated but my focus was the same for both CIRM-funded periods: to understand the effect of the epicardium on heart development and diseases.
In my first project in 2008, we tried to generate an in vitro model of mouse epicardial cells and used those cells to study their influence on cardiac differentiation using both in vitro and in vivo experiments. We ran into a lot of technical difficulties, so at that time, we decided to switch to using existing in vitro epicardial cell lines, and using those to study their influence on cardiomyocytes (heart muscle cells).
In my second year of CIRM funding in 2011, we identified the genes and proteins that can promote immature cardiomyocytes to proliferate, and put them in vivo and it worked. So the success of our publication all started from my second year of CIRM-fellowship.
Q: What benefits did you experience as a CIRM scholar?
KW: I’ve really enjoyed being a CIRM scholar and took advantage of the resources they provided me over the years. One of the benefits I enjoyed the most was attending the CIRM annual meetings and retreats. I was able to talk with a lot of scientists with different backgrounds, and that really expanded my horizons.
As you can see from our paper in Nature, it’s definitely not only a developmental biologist paper. It’s actually very clinical and collaborative, and it was done by many different groups working together. By going to CIRM conferences and meeting all the other CIRM fellows, I got a lot of new ideas, and those ideas encouraged me to collaborate with more scientists. These events really encouraged me to look beyond the thoughts of a developmental biologist.
Our paper is co-authored by me and Vahid Serpooshan from Stanford. We co-first authored this paper, and my work mainly involved the in vitro studies that identified the regenerative proteins and their function in heart injury. Vahid’s approach was more bioengineering focused. He produced the FSTL1 patch, put it in the rodent heart, and conducted all the other in vivo studies. It was a perfect collaboration to push this project for publication in a high level journal like Nature.
Q: What is the big picture of your research and your future goals?
KW: I plan to stay in academia. The key thing about heart diseases is that heart regeneration is very limited. Using our approach, we found one particular protein that’s important to the regenerative process, and in reality, its concentration is very low in the heart when it’s infarcted (injured). I think we have set up a pretty good system to test all possible therapeutic means in the lab, including proteins from the epicardium, small molecules, microRNAs and other compounds to activate cardiomyocyte proliferation. I plan to focus on understanding the mechanisms for why cardiomyocytes stop proliferating in the adult heart, and what new approaches we can pursue to promote their expansion and regenerative abilities. The FSTL1 story is the start of this, and I will try to find new factors that can promote heart regeneration.
Q: Will your work involve human stem cell models?
KW: To make this study clinically relevant, we included the swine models. We are definitely testing FSTL1 in human cells right now. Currently we can produce a huge amount of the human cardiomyocytes. They seem to be at a different stage than rodent cells so we are optimizing the system to perform screens for human cell proliferation. When that system is set up, then anything that comes out of the screen will be much more relevant to clinical studies in humans.
Q: What is your favorite thing about being a scientist?
Knowing that the information I acquire through experiments is new to mankind, and that my actions expand the horizon of combined human knowledge, even just for a tiny bit, is a huge satisfaction to me as a scientist.