Mark W. Majesky, PhD
Children's Title: Director of Myocardial Regeneration Initiative; Principal Investigator
Academic Title: Professor of Pediatrics
Research Center: Center for Developmental Biology and Regenerative Medicine
"I love studying developmental biology and all its implications. It has enriched my life in many ways beyond my job. There is so much beauty in the field for me, and I get so excited when I learn about these biological mechanisms. I would study them even if they weren't part of my career. Knowing that it can have a tangible impact on children makes it worthwhile."
Mark began his research training at the University of Washington (UW) and now returns to the Pacific Northwest to join the Center for Developmental Biology and Regenerative Medicine to lead its groundbreaking program in stem cell biology and regenerative medicine as the director of the Myocardial Regeneration Initiative.
Hoglund VJ, Dong XR, Majesky MWNeointima formation: a local affair.
20844267 Arteriosclerosis, thrombosis, and vascular biology, 2010 Oct. : 1877-9
Yoshida T, Gan Q, Franke AS, Ho R, Zhang J, Chen YE, Hayashi M, Majesky MW, Somlyo AV, Owens GKSmooth and cardiac muscle-selective knock-out of Kruppel-like factor 4 causes postnatal death and growth retardation.
20439457 The Journal of biological chemistry, 2010 July 2 : 21175-84
Majesky MWDevelopmental biology in the vasculature--review series.
19369655 Arteriosclerosis, thrombosis, and vascular biology, 2009 May : 622
Regan JN, Majesky MWBuilding a vessel wall with notch signaling.
19246684 Circulation research, 2009 Feb. 27 : 419-21
Passman JN, Dong XR, Wu SP, Maguire CT, Hogan KA, Bautch VL, Majesky MWA sonic hedgehog signaling domain in the arterial adventitia supports resident Sca1+ smooth muscle progenitor cells.
18591670 Proceedings of the National Academy of Sciences of the United States of America, 2008 July 8 : 9349-54
Dong XR, Maguire CT, Wu SP, Majesky MWChapter 9. Development of coronary vessels.
19022061 Methods in enzymology, 2008 : 209-28
Majesky MWDevelopmental basis of vascular smooth muscle diversity.
17379839 Arteriosclerosis, thrombosis, and vascular biology, 2007 June : 1248-58
Majesky MWOrganizing motility: LIM domains, LPP, and smooth muscle migration.
16484626 Circulation research, 2006 Feb. 17 : 306-8
Hirschi KK, Majesky MWSmooth muscle stem cells.
14699631 The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology, 2004 Jan. : 22-33
Majesky MWDevelopment of coronary vessels.
15522744 Current topics in developmental biology, 2004 : 225-59
Majesky MWDecisions, decisions...SRF coactivators and smooth muscle myogenesis.
12730127 Circulation research, 2003 May 2 : 824-6
Majesky MWVascular smooth muscle diversity: insights from developmental biology.
12667434 Current atherosclerosis reports, 2003 May : 208-13
Majka SM, Jackson KA, Kienstra KA, Majesky MW, Goodell MA, Hirschi KKDistinct progenitor populations in skeletal muscle are bone marrow derived and exhibit different cell fates during vascular regeneration.
12511590 The Journal of clinical investigation, 2003 Jan. : 71-9
Chang DF, Belaguli NS, Iyer D, Roberts WB, Wu SP, Dong XR, Marx JG, Moore MS, Beckerle MC, Majesky MW, Schwartz RJCysteine-rich LIM-only proteins CRP1 and CRP2 are potent smooth muscle differentiation cofactors.
12530967 Developmental cell, 2003 Jan. : 107-18
Majesky MWMouse model for atherosclerotic plaque rupture.
11980677 Circulation, 2002 April 30 : 2010-1
Majesky MWSmooth muscle-specific transcription without a CArG box element.
11934827 Circulation research, 2002 April 5 : 628-30
- Research Description
University of Washington, Department of Pharmacology
University of Washington, Vascular Biology
Assistant Professor, Baylor College of Medicine, Houston, TX
Associate Professor, Baylor College of Medicine, Houston, TX
Professor, University of North Carolina, Chapel Hill, NC
Molecular Basis of Coronary Vessel Development:
We study the development and differentiation of coronary blood vessels. Coronary progenitors are found in the proepicardium, a transient cell population that arises independently of the heart itself. In evolution, the appearance of the proepicardium correlates with the transition of the heart from a primitive tubular structure with a thin-walled, epithelial-type myocardium, as is found in pre- and early chordates, to a thick multilayered pumping organ found in most vertebrates.
Fate mapping studies show that proepicardial cells are the forerunners for the endothelium, smooth muscle and adventitial cells of the coronary vasculature. Formation of coronary vessels occurs by an epithelial to mesenchymal transformation (EMT) of proepicardial cells at the surface of the heart, followed by vasculogenesis in the subepicardial layer, assembly and remodeling of a primitive coronary plexus, and investment by coronary smooth muscle cells (CoSMCs).
We apply molecular biological and developmental genetic approaches to identify pathways for CoSMC commitment and differentiation during heart development. We use both chick and mouse models to explore mechanisms that couple proepicardial cell EMT and transcriptional activation of CoSMC target genes. Current projects in the lab employ transgenic and knockout mice to examine the role of sonic hedgehog signaling, rhoGTPase activation, and cytoskeletal remodeling in the stimulation of SRF and Tbxdependent transcription that mediates proepicardial cell differentiation to CoSMCs.
Role of Tbx18 in Murine Development:
T-box-containing proteins play critical roles as transcription factors that regulate cell fate and differentiation in development. Tbx18 is highly expressed in septum transversum and proepicardium. We used gene targeting in ES cells to produce Tbx18 knockout mice, which die shortly after birth with skeletal, renal and cardiac defects. Current projects aim to characterize these defects in detail, identify binding partners and gene targets for Tbx18, and prepare a conditional null allele for analysis of Tbx18 function in adult mice. Tbx18 is highly expressed in mesothelial membranes that line the pleural, pericardial and peritoneal cavities. These membranes are prone to fibrotic reactions to injury. Fibrosis limits regeneration and repair, restricts end organ function, and is an important cause failure in renal dialysis, and reproductive function after pelvic surgery. Adult models of mesothelial wound repair will allow us to genetically dissect key steps leading to pathological fibrosis.
Another goal of this project is to identify enhancer elements that direct Tbx18 expression to the proepicardium. Using rVISTA phylogenetic sequence comparisons, several conserved intronic elements have been identified as candidate proepicardial enhancers. These elements have been multimerized, ligated into minimal promoter vectors, and are being tested in transgenic frogs and mice.
Sonic Hedgehog Signaling and Adventitial Stem Cells
Blood vessels are continuously undergoing formation, regression, remodeling and repair throughout life. We found a domain of sonic hedgehog signaling restricted to the adventitial layer of artery walls which supports a population of resident vascular stem and progenitor cells. When removed from the adventitial niche environment, these resident progenitors differentiate to mural-like cells (pericytes and smooth muscle cells) in vitro, and closely associate with nascent microvessels in angiogenesis assays in vivo. Maintenance of an adventitial stem/progenitor cell phenotype is dependent upon expression of KLF4. The role of sonic hedgehog signaling in development of the adventitia is an active area of current investigation in the laboratory.
- About My Work
- Research Focus Area
Genetics, Stem Cell Biology, Developmental Biology