Histone Deacetylase Inhibitor, Trichostatin A, Affects Gene Expression Patterns during Morphogenesis of Chicken Limb Buds in vivo

Abstract

Acetylation is one of the key chromatin modifications that control gene transcription during embryonic development and tumorigenesis. The types of genes sensitive to such modifications in vivo are not known to date. We investigated the expression of a number of genes involved in embryonic development after treatment with trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, in the limbs of chicken embryos. Our results show that TSA affects the expression profiles of some genes that play important roles during limb development. The expression of BMP4, SF/HGF and Twist1 increased, whereas the expression of BMP2, FGF8, Shh, Scleraxis, Myf5 and MyoD was decreased or even inhibited. In contrast, the expression of Pax3, Paraxis, Msx1, CREB, and PCNA was not affected. Our results indicate that the chicken embryo can serve as an effective in vivo model for studying the effect of HDAC inhibitors on gene expression and can be helpful for understanding the role of chromatin remodeling and epigenetic control of gene expression.

Diffusible signals and epigenetic timing cooperate in late proximo-distal limb patterning

“…Importantly, TSA applied systemically does not substantially alter normal development, except for a slight increase in the number of somites of mid-gestation mouse embryos (Nervi et al, 2001). In the limb, TSA does not cause a general upregulation of gene expression (Zhao et al, 2009a), and we found that it inhibits a number of distal limb markers, which suggests that the effect on Hoxa13 activation is not due to unspecific unleashing of normally repressed genes. Regarding the skeletal phenotype, the fact that the zeugopod and not the autopod is primarily affected, despite the distal location of the TSA bead, suggests that the premature activation of the autopod program leads to a reduction in the number of cells with a zeugopod expression profile crossing the differentiation front, and this eventually jeopardizes zeugopod size.…”

“…5C; supplementary material Fig. S2) (Zhao et al, 2009a), which indicates that chromatin de-repression is sufficient for Hoxa13 activation in the absence of these limb bud signals, at least in the distal region of the limb (see Discussion).…”

Direct functional consequences of ZRS enhancer mutation combine with secondary long range SHH signalling effects to cause preaxial polydactyly

“…2U). To establish if increased SHH-dependent limb bud expansion is required for the induction of anterior-ectopic SHH and preaxial polydactyly in Slk/Wt leg buds, we locally inhibited growth by implanting TSA-soaked beads into the posterior leg bud mesenchyme, proximal to the ZPA, at stage 18–19HH (Towers et al, 2008; Zhao et al, 2009; Towers et al, 2011). Unlike previous observations, where application of TSA at stage 20HH inhibits anterior digit formation while maintaining posterior digit identity (Towers et al, 2008), Wt/Wt TSA-treated legs either lost posterior digits or had posterior–anterior digit identity transformation (Fig.…”

Development and Regeneration of Sox2+ Endoderm Progenitors Are Regulated by a HDAC1/2-Bmp4/Rb1 Regulatory Pathway

“…Trichostatin A, an inhibitor of class I Hdacs, increases Bmp4 expression in limb bud explants (Zhao et al, 2009). Moreover, Increased Bmp4 expression leads to decreased Sox2 expression in the neural tube (Linker and Stern, 2004).…”