First published online February 4, 2005
Journal of Experimental Biology 208, 697-705 (2005)
Published by The Company of Biologists 2005
doi: 10.1242/jeb.01439
Lifespan extension and elevated hsp gene expression in Drosophila caused by histone deacetylase inhibitors
Yanmei Zhao*,
Hui Sun*,
Jun Lu,
Xiaoxue Li,
Xia Chen,
Dan Tao,
Weifeng Huang and
Baiqu Huang
The Institute of Genetics and Cytology, Northeast Normal University,
Changchun 130024, P.R. China
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Fig. 1. Survival curves of adult Drosophila. iso2: the long-lived
iso-female line, maximum lifespan 73 days, mean lifespan 45.53 days; iso4: the
short-lived iso-female line, maximum lifespan 62 days, mean lifespan 38.47
days. The differences were significant (P<0.01). Values shown are
the means ± S.E.M. of four parallel
experiments.
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Fig. 2. Difference in basal expression of hsp22 (A) and hsp70 (B)
genes during aging between long- and short-lived lines. Total RNA was isolated
from flies, which were cultured and treated as described in the Materials and
methods until 6 days and 30 days. Quantitative real-time PCR was performed to
determine the mRNA expression levels of hsp genes (N=3).
Values are means ± S.E.M.
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Fig. 4. The death curves of adult flies maintained under high temperature. One
hundred flies 6 days after eclosion were kept at 37°C and the number of
dead flies was counted at each of the indicated time points for long-lived
(iso2) and short-lived (iso4) lines. Values shown are the means ±
S.E.M. of four parallel experiments.
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Fig. 5. Survival curves of adult Drosophila maintained at 25°C. (A)
Influence of heat shock on lifespan in the long-lived line. RMHS extended mean
lifespan by 11.5% and maximum lifespan by 5.6%. (B) Influence of the HDAC
inhibitor TSA on lifespan in the long-lived line. Only c.TSA extended mean
lifespan by 15.6%. (C) Influence of HDAC inhibitor BuA on lifespan in
long-lived line. BuA treatment had no obvious effect on both mean and maximum
lifespan. (D) Influence of heat shock and the HDAC inhibitors TSA or BuA on
lifespan in the long-lived line. There was no significant differences among
RMHS, TSA-RMHS and BuA-RMHS treatments. (E) Influence of heat shock on
lifespan in short-lived line. RMHS extended mean lifespan by 25.8% and maximum
lifespan by 11.5%, respectively. (F) Influence of the HDAC inhibitor TSA on
lifespan in the short-lived line. o.TSA slightly increased mean lifespan by
5%, and c.TSA increased mean lifespan by 24.4% and maximum lifespan by 16.4%.
(G) Influence of the HDAC inhibitor BuA on lifespan in the short-lived line.
Only o.BuA increased mean lifespan by 25.8% and maximum lifespan by 11.5%,
respectively. (H) Influence of heat shock and HDAC inhibitor TSA or BuA on
lifespan in short-lived line. No significant differences existed among RMHS,
TSA-RMHS and BuA-RMHS treatments. Values shown are the means ±
S.E.M. of four parallel experiments. con,
control without any treatment; HS, 37°C one-off heat shock induced for 30
minutes only in larvae; RMHS, 32°C repeated mild heat shock for 1 h every
3 days until death; o.TSA, 10 µmol l-1 TSA one-off treatment for
5 h only in larvae; c.TSA, continuous 10 µmol l-1 TSA treatment
until death; o.BuA, 10 mmol l-1 BuA one-off treatment for 5 h only
in larvae; c.BuA, continuous 10 mmol l-1 BuA treatment until
death.
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Fig. 6. Hyperacetylation of histone H3 following HDAC inhibitor treatment and heat
shock induction. (A,B) Western blots of the acetylated histone H3 (AcH3) in
long-lived and in short-lived flies, respectively. The results of
photodensitometric analysis of A and B are shown in C. The upper bands are the
internal reference actin, and the lower bands are acetylated histone H3.
Values shown are the mean ± S.D. of three
independent experiments. *Significant (P<0.05);
**highly significant (P<0.01). Abbreviations as in
Fig. 5.
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Fig. 7. Influence of HDAC inhibitor-induced histone H3 hyperacetylation on
hsp mRNA expression during aging. (A,B) hsp22 mRNA basal
expression in young flies (6-day old; A) and old flies (30-day old; B) after
HDAC inhibitor treatment. (C,D) hsp70 mRNA basal expression in young
flies (6-day old; C) and old flies (30-day old; D) after HDAC inhibitor
treatment. (E,F) hsp22 mRNA inducible expression in young flies
(6-day old; E) and old flies (30-day old; F) after HDAC inhibitor treatment.
(G,H) hsp70 mRNA inducible expression in young flies (6-day old; G)
and old flies (30-day old; H) after HDAC inhibitor treatment. Experiments were
performed in triplicate. Bars represent means ±
S.E.M. For basal expression (A-D),
*P<0.05 and **P<0.01,
versus untreated control. For inducible expression (E-H),
*P<0.05 and **P<0.01,
versus RMHS. Abbreviations as in
Fig. 5.
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Fig. 8. Influence of HDAC inhibitor-induced histone H3 hyperacetylation on Hsp22
protein level. Western blot analysis of Hsp22 in long-lived (iso2) and
short-lived flies (iso4). The upper bands are actin used as the internal
reference and the lower bands are Hsp22 protein. Experiments were performed in
triplicate. The abbreviations as in Fig.
5.
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© The Company of Biologists Ltd 2005
80-fold increase compared to the control.