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A.W. Anderson, M.D.
Professor,
Department of Pediatrics
Assistant Professor,
Department of Cell Biology
Programs: Institutional Cardiovascular Research Training
Faculty, Medical Scientist Training Program
Email
ander005@mc.duke.edu
Research Park Building II
Box 3218
Duke University Medical Center
Durham, NC 27710
Phone 919-684-6027
Fax 919-684-4609
|
The
laboratory research focuses on the heart. The research
examines: the functional consequences of the sequence
differences among the isoforms of cardiac troponin T,
a think filament regulatory protein essential for myofilament
response to calcium; the role of the complement cascade
in the altered vascular permeability that follows cardiopulmonary
bypass; and the regulation of stem cell engraftment and
differentiation in cardiac myocytes in the heart in vivo.
1. We have identified the molecular
basis of the cardiac troponin T isoforms and have demonstrated
correlations between the level of expression of individual
isoforms and myofibrillar ATPase activity, the sensitivity
of the myofilaments to calcium, development, and heart
failure. We express recombinant troponin T in Sf9 cells.
The purified recombinant isoforms are used to replace
endogenous cardiac troponin T in chemically skinned cardiac
preparations and to form the troponin complex in solution.
The troponin complex is reconstituted with recombinant
cardiac troponin I and cardiac troponin C. These intact
troponin complexes are used to assess isoform dependent
modulation of calcium binding to troponin and cross-bridge
formation and kinetics in force generating myofilaments.
The effects of post-translational modifications of these
proteins are examined using these systems. A corollary
of these studies uses transgenic mice overexpressing specific
isoforms. The isoform dependent effects on isolated myocardium
and the in vivo heart are assessed. To examine the relevance
of the troponin T isoforms to function in the failing
heart and as a potential approach for modifying heart
failure, cross-breeding experiments make use of inherited
cardiomyopathies in the mouse.
2. We have demonstrated that blocking
the complement cascades at the level of the C3 convertase
decreases the severity of altered vascular permeability
that follows cardiopulmonary bypass. No specific therapy
is available for the multi-organ damage that results from
the inflammation and abnormal vascular permeability in
the infant following cardiopulmonary bypass. The experimental
protocols make use of an intact piglet model, recombinant
proteins, replacement of endogenous myofilament proteins,
assessment of calcium regulation in isolated myocytes,
and ventricular and pulmonary function.
3. Our most recently developed project
is a collaboration with Dr. Nadia Malouf with the University
of North Carolina at Chapel Hill. These studies are based
on our finding that adult-derived clonal stem cells differentiate
into endothelial and cardiac myocytes in the mouse and
rat heart in vivo. Our studies are focusing on the biology
of engraftment and differentiation and the consequences
of these processes on organ function in the normal animal
and organ dysfunction in animal models of human diseases
in vivo.
Selected Publications
Anderson PAW, Grieg A, Mark TM, Malouf NN, Oakeley AE,
Ungerleider RM, Allen PD, Kay BK. Molecular basis of human
cardiac troponin T isoforms expressed in the developing,
adult, and failing heart. Circ Res 1995;76:681-686.
Chai PJ, Nassar R, Oakeley AE, Craig DM, Quick G, Jaggers
JM, Sanders SP, Ungerleider RM, Anderson PAW. Soluble
complement receptor-1 protects heart, lung, and cardiac
myofilament function from cardiopulmonary damage. Circulation
2000;101:541-546.
Malouf NN, Coleman WB, Grisham JW, Lininger RA, Madden
VJ, Sproul M, Anderson PAW. Adult-derived stem cells from
the liver become myocytes in the heart in vivo. Am J Pathol
2001. In press. |
