Margaret H. Baron
- PROFESSOR Medicine, Hematology and Medical Oncology
- PROFESSOR Developmental and Regenerative Biology
- PROFESSOR Oncological Sciences
- Cellular Differentiation
- Developmental Biology
- Endothelial Cells
- Gene Regulation
- Gene Therapy
- Growth Factors and Receptors
- Image Analysis
- Knockout Mice
- Protein Complexes
- Protein Structure/Function
- Signal Transduction
- Stem Cells
- Transcription Factors
- Transcriptional Activation and Repression
- Transgenic Mice
- Vascular Development
A.B., Harvard University
Ph.D., Massachusetts Institute of Technology
M.D., Harvard Medical School
Health Science and Technology
Massachusetts General Hospital
Biochemistry & Molecular Biology
Margaret H. Baron, MD PhD, is Fishberg Professor of Medicine in Hematology, Director of Hematology and Medical Oncology Research, and a member of the Tisch Cancer Institute (TCI) and Black Family Stem Cell Institute (BFSCI). Dr. Baron is an established scientist who has nearly 24 years of continuous, independent NIH-sponsored research funding in hematopoiesis and a publication record spanning protein biochemistry, virology, cell biology, developmental biology, and stem cell biology. She is well known for her work on the plasticity of the differentiated state, globin gene regulation, and developmental hematopoiesis.
Dr. Baron is a graduate of the Harvard-M.I.T. Program in Health Sciences and Technology (H.S.T.) and holds degrees from Harvard (A.B.), Harvard Medical School (M.D.) and M.I.T. (Ph.D.). She trained in the laboratories of David Baltimore (Ph.D. thesis) and Tom Maniatis (postdoc). Her first independent faculty position was in The Biological Laboratories at Harvard U., where she spent 8 years as an assistant and then associate professor before moving to a tenured position at Mount Sinai in 1997, with an important goal of helping to expand the hematopoiesis and stem cell biology research programs at her new institution. She served for 18 months (2006-2007) as Interim Co-Director of the BFSCI. She is currently Director of the Program in Hematology and Blood Disorders (Division of Hematology and Medical Oncology) and Program Director of an NIH-funded T32 Research Training Program in Molecular and Cellular Hematology (which can support postdoc and clinical fellows).
Dr. Baron is a dedicated educator, having developed and directed courses for PhD and MD/PhD students at Harvard and at Mount Sinai. She is co-founder and Co-Director for the Developmental and Stem Cell Biology (DSCB) Multidisciplinary Training Area (MTA) for PhD and MD/PhD students. She has served as a member of the Steering Committee for the Graduate School of Biomedical Sciences, Assistant Director of the Medical Scientists Training Program (MSTP), and Co-Director for the former Mechanisms of Disease and Therapies Multidisciplinary Training Area (MTA).
To read more about Dr. Baron's research, please visit the Baron Laboratory website.
Executive Leadership in Academic Medicine (ELAM) program
2011 - Present
Association of American Physicians (AAP)
Research Recognition Award
American Cancer Society
2001 - Present
Irene and Dr. Arthur M. Fishberg Professor of Medicine
Mount Sinai School of Medicine
2000 - Present
American Society for Clinical Investigation (ASCI)
1989-92 - 1992
Basil O'Connor Scholar Award
March of Dimes
1987-94 - 1994
Lucille P. Markey Charitable Trust Scholar Award
Our lab combines embryology and stem cell biology, with a focus on mammalian hematopoietic (blood cell) and vascular (blood vessels) development.
One area of investigation is the formation and cell fate specification of mesoderm, the embryonic germ layer that gives rise to blood and endothelial (blood vessel) cells as well as muscle, cartilage and bone. This work utilizes various transgenic mouse and embryonic stem (ES) cell lines to dissect out genetic and molecular pathways involved in these processes.
A second area of investigation that has occupied much of our attention for the past few years is the development of embryonic ("primitive") erythroid (red blood) cells. These "EryP" form in the yolk sac, the first site of hematopoietic development in the mammalian embryo. We have developed transgenic mouse models to monitor and isolate the three major yolk sac cell populations: EryP, vascular endothelial and visceral endoderm. In the mouse, EryP arise in large numbers from yolk sac-derived progenitors at the end of gastrulation, entering the circulation as nucleated cells soon thereafter, and continue to mature in a stepwise and synchronous fashion. By taking advantage of a transgenic mouse line in which fluorescent proteins are expressed exclusively in the EryP lineage, we have been able to follow and purify not only circulating EryP but also the very first erythroid-committed cells that in the yolk sac, as early as embryonic day (E) 7.5. We generated global gene expression profiles at 24 hour intervals from E7.5 through E12.5 that revealed two abrupt changes in transcript diversity that coincided with the entry of EryP into the circulation and with their enucleation, respectively. These changes were paralleled by expression of critical regulatory factors. Experiments designed to test predictions from these data have allowed us to identify key regulatory pathways and factors involved in EryP progenitors and in their more differentiated descendants. Our analysis uncovered not only well studied red blood cell genes but also some surprises. These genes form the basis for ongoing studies. To our knowledge, this is the first transcriptome assembled for a single lineage of the embryo over the course of its differentiation. While we have focused initially on the development of EryP, insights from our microarray studies can also be applied tothe emergence of the first adult type (definitive) hematopoietic stem/progenitor cells.
The transgenic mouse lines we have created can be crossed to generate multiply transgenic lines in which different color fluorescent proteins are expressed in various lineages (for example, in blood cells, endothelial cells, or endoderm cells). We are taking advantage of these lines to image the development of the embryo in real time.
Finally, we are beginning to apply what we have learned from our studies on embryonic red blood cells to the development of adult ("definitive") red blood cells in human patients with hematological diseases.
Baron MH, Isern J, Fraser ST. The embryonic origins of erythropoiesis in mammals. Blood, FIRST EDITION version online 2012 Feb;.
Artus J, Douvaras P, Piliszek A, Isern J, Baron MH, Hadjantonakis AK. BMP4 signaling directs primitive endoderm-derived XEN cells to an extraembryonic visceral endoderm identity. Developmental biology 2012 Jan; 361(2).
Isern J, He Z, Fraser ST, Nowotschin S, Ferrer-Vacquer A, Moore R, Hadjantonakis A, Schulz V, Tuck D, Gallagher PG, Baron MH. Single Lineage Transcriptome Analysis Reveals Key Regulatory Pathways in Primitive Erythroid Progenitors in the Mouse Embryo. Blood 2011; 117: 4924-4934.
Isern J, Fraser ST, He Z, Zhang H, Baron MH. Dose-dependent regulation of primitive erythroid maturation and identity by the transcription factor Eklf. Blood 2010; 116: 3972-3980.
Fraser ST, Isern J, Baron MH. Use of transgenic fluorescent reporter mouse lines to monitor hematopoietic and erythroid development during embryogenesis. Methods in Enzymology 2010; 476: 403-427.
Zhang H, Fraser ST, Papazoglu C, Hoatlin ME, Baron MH. The Mouse Mesendoderm Gene Goosecoid is a Transcriptional Target of the Mixl1 Homeodomain Protein in Differentiating Embryonic Stem Cells. Stem Cells 2009; 27: 2884-2895.
Fraser ST, Baron MH. Embryonic fates for extraembryonic lineages: new perspectives. J. Cellular Biochem. 2009; 107: 586-591.
Isern J, Fraser ST, He Z, Baron MH. The fetal liver is a niche for maturation of primitive erythroid cells. Proc Natl Acad Sci USA 2008; 105: 6662-6667.
Durand C, Robin C, Bollerot K, Baron MH, Ottersbach K, Dzierzak E. Embryonic stromal clones reveal developmental regulators of definitive hematopoietic stem cells. Proc. Natl. Acad. Sci. U.S.A. 2007; 104: 20838-20843.
Fraser ST, Isern J, Baron MH. Maturation and enucleation of primitive erythroblasts is accompanied by changes in cell surface antigen expression patterns during mouse embryogenesis. Blood 2007; 109: 343-352.
Haremaki T, Fraser ST, Kuo YM, Baron MH, Weinstein DC. Vertebrate Ctr1 coordinates morphogenesis and progenitor cell fate and regulates embryonic stem cell differentiation.. Proc. Natl. Acad. Sci. U.S.A 2007; 104: 12029-12034.
Kwon G, Fraser ST, Eakin G, Mangano M, Isern J, Hadjantonakis AK, Baron MH. Tg(Afp-GFP) Expression Marks Primitive and Definitive Endoderm Lineages during Mouse Development. Developmental Dynamics 2006; 235: 2549-2558.
Willey S, Ayuso-Sacido A, Zhang H, Fraser ST, Adlam MA, Sahr K, Kyba M, Daley GQ, Keller G, Baron MH. Acceleration of Mesoderm Development and Expansion of Hematopoietic Progenitors in Differentiating ES Cells by the Mouse Mix-Like Homeodomain Transcription Factor. Blood 2006; 107: 3122-3130.
Baron MH. Early Patterning of the Mouse Embryo: Implications for Hematopoietic Commitment and Differentiation. Experimental Hematology 2005; 33: 1015-1020.
Fraser ST, Hadjantonakis K, Willey S, Sahr KE, Kelly OG, Jones EV, Dickinson ME, Baron MH. Using a Histone Yellow Fluorescent Protein Fusion for Tagging and Tracking Endothelial Cells in ES Cells and Mice. Genesis 2005; 42: 162-171.
Fraser ST, Baron MH. The Specification of Early Hematopoiesis in the Mammal. Current Opinion in Hematology 2005; 12: 217-221.
Physicians and scientists on the faculty of the Icahn School of Medicine at Mount Sinai often interact with pharmaceutical, device and biotechnology companies to improve patient care, develop new therapies and achieve scientific breakthroughs. In order to promote an ethical and transparent environment for conducting research, providing clinical care and teaching, Mount Sinai requires that salaried faculty inform the School of their relationships with such companies.
Below are financial relationships with industry reported by Dr. Baron during 2012 and/or 2013. Please note that this information may differ from information posted on corporate sites due to timing or classification differences.
- Curis Inc.
Mount Sinai's faculty policies relating to faculty collaboration with industry are posted on our website at http://icahn.mssm.edu/about-us/services-and-resources/faculty-resources/handbooks-and-policies/faculty-handbook. Patients may wish to ask their physician about the activities they perform for companies.
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Annenberg Building Floor 24 Room 04E
1468 Madison Avenue
New York, NY 10029