Research
Our work has built the idea that bone does not contain a single stem cell, but instead a series of locally restricted stem cells that are specialized for the physiology of their respective sites. This includes identification of a stem cell in the over layer (periosteum) of limb bones and the flat bones of the skull (calvarium) that is specialized for direct bone formation without a preceding cartilage template (intramembranous ossification; Debnath et al., Nature 2023). This stem cell also collaborates with a second, distinct stem cell to form the skull, and altered interactions between these two skull stem cells can cause disorders of premature skull fusion (Bok et al., Nature 2023). We have also identified a stem cell responsible for forming the spine and found that this stem cell contributes to the high rates of metastasis to the spine versus other skeletal sites seen in breast cancer (Sun et al. Nature, 2023).
In addition to this work on skeletal stem cells, we have a longstanding interest in signaling in the skeleton. This includes identification the of axon guidance cue SLIT3 functions as a skeletal angiogenic factor produced by bone forming osteoblasts (Xu et al., Nature Medicine 2018). We have also identified a negative-regulatory co-receptor for hedgehog ligands, SLITRK5, that acts to control bone formation by osteoblasts (Sun et al. Nature Communications 2021). Lastly, we also have investigated mechanisms of signal transduction in bone forming osteoblasts, including identifying mitogen activated protein kinase (MAPKs) signaling pathways that drive the skeletal effects seen in neurofibromatosis (Bok et al. Nature Communications 2020; Kim JM et al., Nature Communications 2020).
Current Projects:
Currently the Greenblatt lab focuses on identifying new stem cells and other cell types present in the skeleton and understanding how these skeletal stem cells impact local and systemic disease, including identification of additional new stem cells in the spine and skull.
Bio
Dr. Greenblatt is a physician-scientist who leads a research program discovering new stem cells in the skeleton and understanding how these skeletal stem cells impact local and systemic disease. After completing an MS/BS program at Yale University, he then performed MD and PhD studies at Harvard University, completing his PhD in the laboratory of Dr. Laurie Glimcher. Receiving a NIH Director's Early Independence Award and a Burroughs Wellcome Career Award for Medical Scientists allowed him to transition directly to establishing a research lab after completing residency in pathology at Brigham and Women's Hospital. Currently he is in the department of Pathology and Laboratory Medicine at Weill Cornell Medicine. In addition to research, he serves as a practicing pathologist at New York Presbyterian Hospital.
Distinctions:
2022, Fuller Albright Award for “meritorious scientific accomplishment in the bone and mineral field”, American Society for Bone and Mineral Research
2020, Elected Member, American Society for Clinical Investigation
2017 American Society for Clinical Investigation Young Investigator Award
2015 Harold M. Frost Young Investigator Award, Orthopaedic Research Society and the American Society for Bone and Mineral Research
2015 John Haddad Young Investigator Award from the Advances in Mineral Metabolism and the American Society for Bone and Mineral Research
2014 Paul E. Strandjord Young Investigator Award from the Academy of Clinical Physicians and Scientists
2012 Leon Reznick Memorial Prize for excellence in “research and scholarly activities” among graduating Harvard Medical School students
2010 Jeffrey Modell Dissertation Award, Harvard Immunology PhD program