March 2022: Andrew Sproul Lab

Background:

What is the main focus of your lab?

The main focus of our lab is to develop human pluripotent stem cell (hPSC) models of Alzheimer’s disease (AD) to better understand disease pathogenesis and to elucidate alternative therapeutic strategies. In this context we also develop novel hPSC differentiation protocols.  While researchers have cured “AD” in a mouse over a 100 times,there are still no significantly effective treatments in actual people. I think it is likely that we don’t understand the disease as well as we think we do and that there are critical human-specific components to AD. To this end, I run a proactive collaborative resource, the Stem Cell & Cellular Models Platform in the Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, which provides access to human stem cell models of AD for Taub researchers. I also run my own research program, and in practice, these two activities are often blended.

How long have you had your lab? When did you join Columbia University?

I started my lab in early 2015 after leaving the New York Stem Cell Foundation (NYSCF) where I was the 5 previous years. It was a homecoming in a sense, as I did my PhD at Columbia in the Biological Sciences department on the “downtown” campus while performing my doctoral research on the “uptown” campus with Lloyd Greene in Pathology & Cell Biology.

How big is your lab currently?

My lab currently has 4 full-time members, Ronak, Ellen, Elliot and Emily, as well as 1 volunteer/former SURF student Patrick.

Where is your lab located?

We are in the Black Building 10-02, conveniently located near both the main CSCI and Taub basic research floors.

Current affairs:

What are the most exciting projects/directions in the lab at this moment?

Although we probably have too many projects at the moment, I’ll briefly highlight four of them. The first is a collaboration with Dr. Joe Lee, where we are trying to better understand how protective genetic variants for familial AD (FAD), indentifid by Joe, exert their beneficial effects. We have concentrated on one protective SNP that delays onset of FAD by almost a decade in PSEN1 G206A carriers, which we believe works, at least in part, by dampening the microglial response to inflammatory stimuli, particularly against microbes. We plan on submitting a paper on this topic in the near future. Second, in collaboration with my Co-PIs and fellow CSCI affiliated members Drs. Alex Chavez and Gunnar Hargus, we are using CRISPRi/a screens to assess over 100 GWAS-identified AD genetic risk factors in the context of neuroinflammation. It is exciting to look at something at a larger scale than I might typically do and get at least an initial handle on what this plethora of gene hits might be doing. Third, in collaboration with Dr. Dritan Agalliu we are trying to develop a better human blood brain barrier (BBB) in vitro model. In a paper we contributed to, led by Dritan and other researchers at Weill Cornell (Lu et al., PNAS 2021), we showed that the most commonly used brain microvascular endothelial cell (BMEC) protocols, including those used by some very prominent researchers, in fact wrongly identifies the cells they produced as endothelial origin when they are in fact epithelial in nature (albeit with good barrier properties). We are leading efforts with Dritan to produce BMECS with bona fide BMEC idendity as well strong barrier properties, using a combination of directed development and transdifferentation approaches. Finally, for our most translational project, in collaboration with Dr. Andy Teich we are in the middle of conducting a screen of ~1000 compounds in hIPSC-derived neurons for beneficial effects on synaptic function, as synaptic loss correlates well with disease progression in AD. The readout is bar-coded RNA-Seq (PLATE-Seq) for each drug-treated 96 well-well. In order to interpret these lower read depth profiles, we have identified master regulators (MRs) in human neurons generated by Ngn2-mediated transdifferentiation, which are associated with the expression of many other genes which we can use the MR as a proxy for. In order to identify these MRs, we first made a human neuron interactome using 150 full depth RNA-Seq profiles generated from neurons derived from 10 independent permanent Ngn2/rtTA hPSC lines treated with 15 different stimuli in order to increase transcriptomic diversity.

What are the biggest accomplishments that your lab recently had?

Although I was very excited to have helped with recent publications with other Columbia researchers including Dritan Agalliu (PNAS paper mentioned above), Estela Area Gomez (EMBO 2020), and Francesca Bartolini (Brain, in Press), I am most proud of my first senior author paper by my former associate research scientist Saera Song (Song et. al, Current Protocols 2021). In this paper we described our efficient method of generating permanent lines with inducible transcription factors to derive excitatory (Ngn) and inhibitory (Ascl1, Dlx2) neurons by the simple addition of doxycycline and neural media. I’m also most excited about upcoming accomplishments, as we have many projects that are finally coming to near fruition.

Technology:

What are the model systems that your lab is using?

We exclusively use hPSC models, the majority of which are CRISPR-mediated knockins of late-onset AD (LOAD) and FAD genetic risk factors generated by my lab. We are in the process of starting to deposit published lines in repositories for broader dissmenatiion to the AD researcher community.

What are the key techniques that your lab is using? Are you open to training scientists from other labs?

Our lab routinely uses hPSC differentiation protocols to generate CNS cell types and various CRISPR technologies to genome-edit or to modulate gene expression. While I have advised on these topics which I am happy to continue to do, we don’t have the bandwidth to formally train people outside of our lab.

What facilities or equipment does your lab absolutely rely upon? Do you use CSCI cores?

 We absolultely rely on both CSCI cores frequently, and I cannot speakly highly enough about Directors Barbara and Mike on both a professional and a personal level.

Who shall be contacted with questions about equipment, resources and training?

You should probably contact me directly first at aas2003@cumc.columbia.edu, although I may pass you to someone in my lab depending on the question.

Training:

What's your best approach to mentoring trainees in the lab?

I think that people generally will rise to challenge, so I keep my expectations high in terms of intellectual engagement for non-PhDs in my lab. I treat technicians as more of a hybrid technician/graduate student role, which reflects my own  prior experience as a technician. For PhD level trainees (or graduate students), I think it is important to allow a level of scientific play as I like to call it. I was fortunate to have had a lot of freedom to pursue my own approaches/scientific ideas during my training so I try to allow the same for my trainees.

Who were your most influential mentors/role models in science and what did you learn from them?

The two most important scientific mentors in my career have been the late Sir Hans Kornberg at Boston Universisty and my doctoral advisor Lloyd Greene at Columbia. When I started working as a technician with Sir Hans, I was really lost in general after having gotting laid off from a really toxic first technican job at Brigham & Women’s Hospital (the PI shut down the lab to go to Harvard Business School) and having withdrawn my applications to medical school. I really grew to love the practice of scientific research during my three years with him, which is why I pursued a PhD. Lab meeetings were simply discussing the science over weakly brewed black coffee, including coming up with extra experiments to do that day on the fly. It was also great training to eventually run my own lab, as I ran the daily operations of the lab myself as the only other members were undergraduate researchers during the academic year who reported to me (in addition to Sir Hans). While doing my PhD with Lloyd, I really learned to think about science at a deeply mechanistic level. Lloyd gave me a lot of scientific freedom as well as the freedom to fail. It was a highly engaging environment, particularly since we also shared lab space and lab meetings with Drs. Michael Shelanski and Carol Troy. Lloyd thinks very deeply about scientific problems, is amazingly level headed about scientific progress, is the eiptomy of scientific integrity, and is an incredible writer, hopefully at least a little bit of which rubbed off on me during my time with him.

What would be your career advice for students/postdocs?

Be flexible in how your career aspirations manifest and be prepared to hard pivot when necessary. In my own career, I jumped from a bad initial postdoc at Mt. Sinai to working at NYSCF, a non-profit research institute (as well as foundation) where I participated in both academic and pharma collaborations. While that was an absolutely amazing experience with wonderful people, when it was clear there was no potential path to advance to the independent investigator level, at least at that time, I pivoted again back to academia to my current position. I have been able to develop my own independent research program while running a resource, albeit not trivially.

Are you accepting rotating students at the moment?

I would love to take a rotating student, although if you were to join my lab it would likely be a joint mentorship with one of our collaborators.

Lab management:

How do members of your lab celebrate accomplishments?

Usually with food.

What is the key to running a successful lab?

To remember the most important resource of a lab is its people. The part of running my lab I am the most proud of is the ongoing success of fomer lab members, which has included matriculation to Phd, MD, and MD/PhD programs for technicians, and a principle scientist position at a startup for the first PhD level person to leave my lab. I try to create a ‘win-win” situation for anyone who joins my group, which is my philosophy for interacting with other scientific partners in general.

What was the most exciting part about starting your new lab?

I had a lot of freedom to shape the newly-formed Platform in the way I thought to be most effective.

Stem Cell Directions:

What are the most important recent developments in the stem cell field?

?While its not stem cell-specific, I am amazed at the rapid progression of CRISPR technologies and how they can be applied in a stem cell context.

Which stem cell conferences does your lab attend?

We almost always attend the NYSCF Translational Stem Cell Conference at Rockefeller, and ISSCR when possible.

CSCI:

What was the main reason of you joining CSCI? What are the beneficial aspects of CSCI membership for your lab?

Although it was nice to be surrounded by so many other AD researchers when I joined the Taub Insitute, I felt less connected to the broader stem cell community than when I was at NYSCF. Joining CSCI helped alleviate that, and I think many of the high quality seminars and CSCI programmed activities are a boon to my lab.

What do you plan to bring to the CSCI community?

I think the differentiation protocols we develop could be useful to some members, and I also bring a pretty solid sense of humor.