Abstract
The epigenetic silencing of exogenous transcriptional units integrated into the genome represents a critical problem both for long-term gene therapy efficacy and for the eradication of latent viral infections. We report here that limitation of essential amino acids, such as methionine and cysteine, causes selective up-regulation of exogenous transgene expression in mammalian cells. Prolonged amino acid deprivation led to significant and reversible increase in the expression levels of stably integrated transgenes transcribed by means of viral or human promoters in HeLa cells. This phenomenon was mediated by epigenetic chromatin modifications, because histone deacetylase (HDAC) inhibitors reproduced starvation- induced transgene up-regulation, and transcriptome analysis, ChIP, and pharmacological and RNAi approaches revealed that a specific class II HDAC, namely HDAC4, plays a critical role in maintaining the silencing of exogenous transgenes. This mechanism was also operational in cells chronically infected with HIV-1, the etiological agent of AIDS, in a latency state. Indeed, both amino acid starvation and pharmacological inhibition of HDAC4 promoted reactivation of HIV-1 transcription and reverse transcriptase activity production in HDAC4 + ACH-2 T-lymphocytic cells but not in HDAC4 - U1 promonocytic cells. Thus, amino acid deprivation leads to transcriptional derepression of silenced transgenes, including integrated plasmids and retroviruses, by a process involving inactivation or down-regulation of HDAC4. These findings suggest that selective targeting of HDAC4 might represent a unique strategy for modulating the expression of therapeutic viral vectors, as well as that of integrated HIV-1 proviruses in latent reservoirs without significant cytotoxicity.
| Original language | English |
|---|---|
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 109 |
| Issue number | 34 |
| DOIs | |
| Publication status | Published - Aug 21 2012 |
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Keywords
- GPR143
- HIV-1 latency
- Ocular albinism type 1
- TNF alpha
- Tyrosine
ASJC Scopus subject areas
- General
Cite this
Amino acid starvation induces reactivation of silenced transgenes and latent HIV-1 provirus via down-regulation of histone deacetylase 4 (HDAC4). / Palmisano, Ilaria; Della Chiara, Giulia; D'Ambrosio, Rosa Lucia; Huichalaf, Claudia; Brambilla, Paola; Corbetta, Silvia; Riba, Michela; Piccirillo, Rosanna; Valente, Sergio; Casari, Giorgio; Mai, Antonello; Boneschi, Filippo Martinelli; Gabellini, Davide; Poli, Guido; Schiaffino, Maria Vittoria.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 109, No. 34, 21.08.2012.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Amino acid starvation induces reactivation of silenced transgenes and latent HIV-1 provirus via down-regulation of histone deacetylase 4 (HDAC4)
AU - Palmisano, Ilaria
AU - Della Chiara, Giulia
AU - D'Ambrosio, Rosa Lucia
AU - Huichalaf, Claudia
AU - Brambilla, Paola
AU - Corbetta, Silvia
AU - Riba, Michela
AU - Piccirillo, Rosanna
AU - Valente, Sergio
AU - Casari, Giorgio
AU - Mai, Antonello
AU - Boneschi, Filippo Martinelli
AU - Gabellini, Davide
AU - Poli, Guido
AU - Schiaffino, Maria Vittoria
PY - 2012/8/21
Y1 - 2012/8/21
N2 - The epigenetic silencing of exogenous transcriptional units integrated into the genome represents a critical problem both for long-term gene therapy efficacy and for the eradication of latent viral infections. We report here that limitation of essential amino acids, such as methionine and cysteine, causes selective up-regulation of exogenous transgene expression in mammalian cells. Prolonged amino acid deprivation led to significant and reversible increase in the expression levels of stably integrated transgenes transcribed by means of viral or human promoters in HeLa cells. This phenomenon was mediated by epigenetic chromatin modifications, because histone deacetylase (HDAC) inhibitors reproduced starvation- induced transgene up-regulation, and transcriptome analysis, ChIP, and pharmacological and RNAi approaches revealed that a specific class II HDAC, namely HDAC4, plays a critical role in maintaining the silencing of exogenous transgenes. This mechanism was also operational in cells chronically infected with HIV-1, the etiological agent of AIDS, in a latency state. Indeed, both amino acid starvation and pharmacological inhibition of HDAC4 promoted reactivation of HIV-1 transcription and reverse transcriptase activity production in HDAC4 + ACH-2 T-lymphocytic cells but not in HDAC4 - U1 promonocytic cells. Thus, amino acid deprivation leads to transcriptional derepression of silenced transgenes, including integrated plasmids and retroviruses, by a process involving inactivation or down-regulation of HDAC4. These findings suggest that selective targeting of HDAC4 might represent a unique strategy for modulating the expression of therapeutic viral vectors, as well as that of integrated HIV-1 proviruses in latent reservoirs without significant cytotoxicity.
AB - The epigenetic silencing of exogenous transcriptional units integrated into the genome represents a critical problem both for long-term gene therapy efficacy and for the eradication of latent viral infections. We report here that limitation of essential amino acids, such as methionine and cysteine, causes selective up-regulation of exogenous transgene expression in mammalian cells. Prolonged amino acid deprivation led to significant and reversible increase in the expression levels of stably integrated transgenes transcribed by means of viral or human promoters in HeLa cells. This phenomenon was mediated by epigenetic chromatin modifications, because histone deacetylase (HDAC) inhibitors reproduced starvation- induced transgene up-regulation, and transcriptome analysis, ChIP, and pharmacological and RNAi approaches revealed that a specific class II HDAC, namely HDAC4, plays a critical role in maintaining the silencing of exogenous transgenes. This mechanism was also operational in cells chronically infected with HIV-1, the etiological agent of AIDS, in a latency state. Indeed, both amino acid starvation and pharmacological inhibition of HDAC4 promoted reactivation of HIV-1 transcription and reverse transcriptase activity production in HDAC4 + ACH-2 T-lymphocytic cells but not in HDAC4 - U1 promonocytic cells. Thus, amino acid deprivation leads to transcriptional derepression of silenced transgenes, including integrated plasmids and retroviruses, by a process involving inactivation or down-regulation of HDAC4. These findings suggest that selective targeting of HDAC4 might represent a unique strategy for modulating the expression of therapeutic viral vectors, as well as that of integrated HIV-1 proviruses in latent reservoirs without significant cytotoxicity.
KW - GPR143
KW - HIV-1 latency
KW - Ocular albinism type 1
KW - TNF alpha
KW - Tyrosine
UR - http://www.scopus.com/inward/record.url?scp=84865194183&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865194183&partnerID=8YFLogxK
U2 - 10.1073/pnas.1202174109
DO - 10.1073/pnas.1202174109
M3 - Article
C2 - 22826225
AN - SCOPUS:84865194183
VL - 109
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 34
ER -