Elucidation of a Novel Pathway through Which HDAC1 Controls Cardiomyocyte Differentiation through Expression of SOX-17 and BMP2
et al. (2012) Elucidation of a Novel Pathway through Which HDAC1 Controls Cardiomyocyte
Differentiation through Expression of SOX-17 and BMP2. PLoS ONE 7(9): e45046. doi:10.1371/journal.pone.0045046
Elucidation of a Novel Pathway through Which HDAC1 Controls Cardiomyocyte Differentiation through Expression of SOX-17 and BMP2
Eneda Hoxha 0
Erin Lambers 0
John A. Wasserstrom 0
Alexander Mackie 0
Veronica Ramirez 0
Tatiana Abramova 0
Suresh K. Verma 0
Prasanna Krishnamurthy 0
Raj Kishore 0
Yao Liang Tang, University of Cincinnati, United States of America
0 Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University , Chicago, Illinois , United States of America
Embryonic Stem Cells not only hold a lot of potential for use in regenerative medicine, but also provide an elegant and efficient way to study specific developmental processes and pathways in mammals when whole animal gene knock out experiments fail. We have investigated a pathway through which HDAC1 affects cardiovascular and more specifically cardiomyocyte differentiation in ES cells by controlling expression of SOX17 and BMP2 during early differentiation. This data explains current discrepancies in the role of HDAC1 in cardiovascular differentiation and sheds light into a new pathway through which ES cells determine cardiovascular cell fate.
-
Funding: Work described in this manuscript was supported in part by National Institute of Health grants HL091983, HL105597, HL095874, HL053354 and
HL108795 to RK and American Heart Associations pre-doctoral fellowship grant 11PRE7360065 to EH. The funders had no role in study design, data collection and
analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
Since they were first isolated over a decade ago, ES cells have
paved the way for exciting new discoveries [1]. It is through
studying the molecular circuitry of ES cells that we have been able
to learn key factors that govern pluripotency and differentiation
[2,3] [46].
HDAC1 has been widely studied due to its implication in many
disorders and has been shown to be important during
development [7,8]. HDAC1 knockout mice are embryonic lethal, however
cardiac restricted knockout of HDAC1 under the alpha-MHC
promoter does not show any deficiencies in heart structure and
function at baseline [8]. This has led to the belief that HDAC1 and
HDAC2 have redundant roles during differentiation in the heart
[8]. Other research investigating the role of HDACs, also points at
a possible redundancy between different HDACs. However, most
of the current work on HDACs has been done using chemical
inhibitors of these enzymes that are not specific to any one HDAC
in particular and weekly class specific [9,10]. A possible
redundancy in the role of HDAC1 and HDAC2, however, cannot
explain the severe phenotype observed in the global knockout.
Additionally, it is not clear at what stage during development
HDAC1 is important, so tissue restricted KO of this gene might
bypass the stage in which HDAC1 is important and fail to
recognize and understand its role. In fact, alpha-MHC is
expressed at a very late point in cardiomyocyte development
and is more of a maturation marker than a marker for
commitment towards the cardiomyocyte phenotype. ES cells are
very efficient and useful models to study developmental pathways
that cannot be clearly elucidated through the use of KO mice.
Because of the apparent discrepancy described in earlier published
data for the role of HDAC1, we investigated a possible role for this
enzyme in mES cell early differentiation into the cardiovascular
cell lineage and elucidated a pathway through which HDAC1
controls cardiomyocyte differentiation. Data presented in this
manuscript sheds new light into the cardiomyocyte differentiation
circuity of ES cells.
Results and Discussion
To elucidate the role of HDAC1 in mES cells in early
differentiation and to investigate any cell type specific effects of
HDAC1, we created shRNA-mediated stable HDAC1-knock
down (HDAC1-KD) cell lines in ES cells (Fig. 1A).
Based on the discrepancy for the role of HDAC1 in the
development of the heart observed in previous published work, we
hypothesized that HDAC1 played a key role very early in
differentiation, before cardiac markers were expressed and was
needed for these early specification genes to be expressed. Thus,
we investigated the role of HDAC1 in the differentiation of
pluripotent cells in vitro. We were particularly interested in
determining the stage during cardiovascular differentiation at
which HDAC1 was important and the pathway through which it
induced cardiovascular differentiation.
We investigated the molecular pathway through which HDAC1
was affecting expression of downstream transcription factors
important for cardiovascular differentiation. We induced
differentiation through Embryoid Body (EB) formation in both wild
type (w (...truncated)