Effects of histone deacetylase inhibitors on transcriptional regulation of the hsp70 gene in Drosophila

Abstract

npg Histone acetyltransferases/deacetylases contribute to the activation or inactivation of transcription by modifying the structure of chromatin. Here we examined the effects of histone deacetylase inhibitors (HDIs), trichostatin A, and sodium butyrate on hsp70 gene transcriptional regulation in Drosophila. The chromatin immunoprecipitation assays revealed that HDI treatments induced the hyperacetylation of histone H3 at the promoter and the transcribing regions of hsp70 gene, increased the accessibility of heat-shock factor to target heat-shock element, and promoted the RNA polymerase II-mediated transcription. Moreover, the quantitative real-time PCR confirmed that the HDI-induced hyperacetylation of histone H3 enhanced both the basal and the inducible expression of hsp70 mRNA level. In addition, the acetylation level of histone H3 at the promoter exhibited a fluctuated change upon the time of heat shock. These experimental data implicated a causal link between histone acetylation and enhanced transcription initiation of hsp70 gene in Drosophila.

Rabies virus glycoprotein expression in Drosophila S2 cells. I: Design of expression/selection vectors, subpopulations selection and influence of sodium butyrate and culture medium on protein expression

“…This situation may occur during the process of gene transfection and integration and cannot be avoided. Sodium butyrate (NaBu) by inhibiting histone deacetylase promotes chromatin exposure which leads to increased transcription of "silent" regions of the genome (Chen et al, 2002;Dorner et al, 1989;Li and Li, 2006;Ping et al, 2006;Santos et al, 2007;Song et al, 2006;Zhao et al, 2006). Depending on the magnitude of the NaBu effect, it leads to cell mortality due to cell deregulation, but the increased transcription may allow the transcription of heterologous genes integrated into the "silent" regions of the genome.…”

Improving heterologous protein expression in transfected Drosophila S2 cells as assessed by EGFP expression

“…Based on published studies (Dorner et al 1989;Chen et al 2002;Li and Li 2006;Zhao et al 2006;Ping et al 2006;Song et al 2006), sodium butyrate (NaBu), is a histone deacetylase inhibitor, affecting the chromatin structure and leading to the destabilization of nucleosomal structure. As a consequence, the NaBU influence on chromatin exposure may facilitate binding of transcription factors to DNA resulting in an increased and deregulated cell protein synthesis.…”

“…In this context, the transfection procedure, aiming the introduction of foreign DNA into cells, is an important step. The calcium phosphate method has been recommended for gene transfection of S2 cells (Van der Straten et al 1989) but procedures based on liposome reagent have been reported to be more efficient (Han 1996;Park et al 1999;Shin and Cha 2002) Besides the metallothionein promoter induction by copper sulfate (CuSO 4 ) (Huang et al 2004) it has been studied the enhancement of gene expression by agents, such as the sodium butyrate (NaBu), a histone deacetylase inhibitor that lead to chromatin exposure and allow the transcriptional factors binding and increased gene expression (Dorner et al 1989;Li and Li 2006;Zhao et al 2006;Ping et al 2006;Song et al 2006).…”

Life Extension in Drosophila by Histone Deacetylase Inhibitors

“…The changes obtained were accompanied by the hyperacetylation of core histone H3 and elevated levels of expression of hsp22 and hsp70 genes. In the subsequent study by the same authors (Zhao et al 2006), treatment with SB caused elevated acetylation levels at histone H3 located at both promoter and coding regions of the hsp70 gene, along with enhanced accessibility of heatshock factor to target element and increased rate of RNA polymerase II-mediated transcription. The SB-induced hyperacetylation of histone H3 resulted in upregulation of both basal and inducible hsp70 expression.…”