Heat shock transcription factor 1-activating compounds suppress polyglutamine-induced neurodegeneration through induction of multiple molecular chaperones - PubMed Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Sep 19;283(38):26188-97.
doi: 10.1074/jbc.M710521200. Epub 2008 Jul 16.

Heat shock transcription factor 1-activating compounds suppress polyglutamine-induced neurodegeneration through induction of multiple molecular chaperones

Nobuhiro Fujikake  1 , Yoshitaka Nagai, H Akiko Popiel, Yuma Okamoto, Masamitsu Yamaguchi, Tatsushi Toda
Affiliations

Heat shock transcription factor 1-activating compounds suppress polyglutamine-induced neurodegeneration through induction of multiple molecular chaperones

Nobuhiro Fujikake et al. J Biol Chem. .

Abstract

Many neurodegenerative diseases including Alzheimer, Parkinson, and polyglutamine (polyQ) diseases are thought to be caused by protein misfolding. The polyQ diseases, including Huntington disease and spinocerebellar ataxias (SCAs), are caused by abnormal expansions of the polyQ stretch in disease-causing proteins, which trigger misfolding of these proteins, resulting in their deposition as inclusion bodies in affected neurons. Although genetic expression of molecular chaperones has been shown to suppress polyQ protein misfolding and neurodegeneration, toward developing a therapy, it is ideal to induce endogenous molecular chaperones by chemical administration. In this study, we assessed the therapeutic effects of heat shock transcription factor 1 (HSF1)-activating compounds, which induce multiple molecular chaperones, on polyQ-induced neurodegeneration in vivo. We found that oral administration of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) markedly suppresses compound eye degeneration and inclusion body formation in a Drosophila model of SCA. 17-AAG also dramatically rescued the lethality of the SCA model (74.1% rescue) and suppressed neurodegeneration in a Huntington disease model (46.3% rescue), indicating that 17-AAG is widely effective against various polyQ diseases. 17-AAG induced Hsp70, Hsp40, and Hsp90 expression in a dose-dependent manner, and the expression levels correlated with its therapeutic effects. Furthermore, knockdown of HSF1 abolished the induction of molecular chaperones and the therapeutic effect of 17-AAG, indicating that its therapeutic effects depend on HSF1 activation. Our study indicates that induction of multiple molecular chaperones by 17-AAG treatment is a promising therapeutic approach for a wide range of polyQ diseases and possibly other neurodegenerative diseases.

PubMed Disclaimer

Figures

FIGURE 1.
FIGURE 1.
17-AAG treatment suppresses compound eye degeneration in the MJDtr-Q78S flies. Light microscopic images of the compound eye morphologies of 1-day-old MJDtr-Q78S flies treated with various HSF1-activating compounds. A, untreated MJDtr-Q78S flies show severe compound eye degeneration. B, notably, treatment with 17-AAG (1.5 μm), an HSF1-activating compound, strongly suppressed compound eye degeneration in the MJDtr-Q78S flies. C and D, treatment with GA (5 μm, C) or RA (5 μm, D) moderately suppressed compound eye degeneration. E and F, treatment with neither CL (100 μm, E) nor GGA (40 mm, F) showed any detectable changes in compound eye degeneration. G, treatment with SB (10 mm), a histone deacetylase inhibitor used as a positive control, weakly suppressed compound eye degeneration. Fly genotype is gmr-GAL4/+; UAS-MJDtr-Q78S/+.
FIGURE 2.
FIGURE 2.
17-AAG suppresses polyQ-induced compound eye degeneration in a dose-dependent manner. Light microscopic images of the compound eye morphologies of 1-day-old MJDtr-Q78S flies treated with various concentrations of 17-AAG. A, untreated MJDtr-Q78S flies. B-F, 17-AAG treatment at concentrations of 500 nm (C), 1.5 μm (D), and 5 μm (E) strongly suppressed compound eye degeneration in the MJDtr-Q78S flies, whereas treatment at 50 nm (B) showed modest suppression. However, 17-AAG treatment at 50 μm (F) failed to improve compound eye degeneration in the MJDtr-Q78S flies. These data indicate that 17-AAG treatment up to 5 μm suppresses polyQ-induced neurodegeneration in a dose-dependent manner. Fly genotype is gmr-GAL4/+; UAS-MJDtr-Q78S/+.
FIGURE 3.
FIGURE 3.
17-AAG suppresses degeneration of photoreceptor neurons in the Htt-Q128 flies. A-F, toluidine blue-stained sections of the eyes of 1-day-old Htt-Q128 flies treated with various HSF1-activating compounds (5 μm). Expression of the Htt-Q128 protein caused progressive photoreceptor degeneration, resulting in loss of rhabdomeres in each ommatidium (B), whereas flies expressing the GAL4 activator protein alone (Control) showed normal structures of ommatidia (A). Notably, 17-AAG remarkably suppressed photoreceptor degeneration in the Htt-Q128 flies (C). GA (D) and RA (E) moderately suppressed photoreceptor degeneration. SB, used as a positive control, also showed moderate suppression (F). Fly genotypes are gmr-GAL4/+; UAS-Htt-Q128/+ (B-F) or gmr-GAL4/+ (A). G, the average number of rhabdomeres/ommatidium in the Htt-Q128 flies treated with various HSF1-activating compounds. 17-AAG significantly suppressed photoreceptor degeneration, resulting in an increase in the number of rhabdomeres/ommatidium from 4.6 ± 0.3 to 5.7 ± 0.1. GA, RA, and SB modestly increased the number of rhabdomeres to 5.1 ± 0.2, to 5.1 ± 0.2, and to 5.3 ± 0.3, respectively. H, the percentage of rescue of photoreceptor degeneration in the Htt-Q128 flies by treatment with HSF1-activating compounds. 17-AAG most effectively rescued photoreceptor degeneration in the Htt-Q128 flies (46.3 ± 5.5%) as compared with GA, RA, and SB (22.8 ± 8.3, 22.0 ± 8.5, and 29.8 ± 10.5% respectively). The data are expressed as the means ± S.E. (n ≥ 3). *, p < 0.05; **, p < 0.01 (Student's t test).
FIGURE 4.
FIGURE 4.
17-AAG increases the survival rate of the MJDtr-Q78S flies during their development to adults. The survival rates during the development to adults are shown of flies expressing the MJDtr-Q78 protein within the nervous system treated with 17-AAG. The ratio of the MJDtr-Q78S flies to the control flies was calculated by dividing the number of emerging flies not bearing CyO (MJDtr-Q78S flies) by that of emerging flies bearing CyO (control flies) to evaluate the survival rate of the MJDtr-Q78S flies. Expression of the MJDtr-Q78 protein significantly decreased the survival rate (46.2 ± 14.4%), whereas the MJDtr-Q27 protein did not cause any significant changes (105.2 ± 12.6%). Notably, 17-AAG treatment significantly increased the survival rate of the MJDtr-Q78S flies (86.0 ± 9.8%), corresponding to a 74.1 ± 16.5% rescue of the lethality. The data are expressed as the means ± S.E. (n = 3). *, p < 0.05 (Student's t test). Fly genotypes are elav-GAL4/UAS-MJDtr-Q78S (MJDtr-Q78S) or elav-GAL4/UAS-MJDtr-Q27 (MJDtr-Q27).
FIGURE 5.
FIGURE 5.
17-AAG suppresses inclusion body formation of the MJDtr-Q78 protein without affecting its expression level. A-D, confocal microscopic images of eye-antennal discs of third instar larvae of the MJDtr-Q78W flies treated with 17-AAG (1.5 μm), stained with an anti-HA antibody to detect the MJDtr-Q78 protein. Lower (×200, A, B) and higher (×630, C, D) magnification images are shown. Eye portions (posterior) are to the right, and antennal portions (anterior) to the left. The arrowheads indicate morphogenetic furrows. The 17-AAG-treated MJDtr-Q78W flies (B and D) have significantly fewer inclusion bodies (arrows) as compared with the untreated flies (A and C). E and F, quantitative analyses of the effects of 17-AAG on inclusion body formation. Schematic representation is shown of an eye disc, in which inclusion bodies (red) are formed in the area where the MJDtr-Q78 protein is expressed (gray in F, right). The ratio of the anteroposterior width of the area with cells containing inclusion bodies (Wi) to that of the area with cells containing the diffusely distributed MJDtr-Q78 protein (Wd) was calculated. The ratio of Wi/Wd was significantly decreased by 17-AAG treatment from 0.84 ± 0.04 to 0.59 ± 0.05 (E). The data are expressed as the means ± S.E. (n ≥ 7). *, p < 0.01 (Student's t test). Fly genotype is gmr-GAL4/+; +; UAS-MJDtr-Q78W/+. G, Western blot analyses of the MJDtr-Q78 protein in the MJDtr-Q78S flies treated with 17-AAG using an anti-HA antibody to detect the MJDtr-Q78 protein (upper panel) and an anti-tubulin antibody (lower panel). 17-AAG did not affect the expression level of the MJDtr-Q78 protein. Fly genotypes are gmr-GAL4/+, UAS-MJDtr-Q78S/+ (MJDtr-Q78S), or gmr-GAL4/+ (control, Cont).
FIGURE 6.
FIGURE 6.
17-AAG induces expression of molecular chaperones in a dose-dependent manner. A, RT-PCR analyses of Hsp70, Hsp40, and Hsp90 mRNAs expressed in third instar larvae of the MJDtr-Q78S flies treated with 17-AAG (50 nm, 500 nm, 5 μm, or 50 μm). Flies expressing the GAL4 activator protein alone (Cont) exposed to heat shock (HS) were used as a positive control. The rp49 mRNA was also analyzed as an internal control. B-D, real time quantitative RT-PCR analyses of Hsp70, Hsp40, and Hsp90 mRNAs expressed in the MJDtr-Q78S fly larvae. Treatment with 17-AAG up to 5 μm induced expression of Hsp70 (B), Hsp40 (C), and Hsp90 (D) mRNAs in a dose-dependent manner (60.87-, 2.20-, and 2.42-fold at 5 μm, respectively). The results shown are from representative experiments. The data are expressed as the means ± S.E. (n = 3). Fly genotypes are gmr-GAL4/+, UAS-MJDtr-Q78S/+ (MJDtr-Q78S), or gmr-GAL4/+ (control).
FIGURE 7.
FIGURE 7.
RNAi-mediated knockdown of HSF1 abolishes the therapeutic effect of 17-AAG on compound eye degeneration in the MJDtr-Q78S flies. A, Western blot analyses of the HSF1 protein expressed in SL2 cells co-transfected with expression vectors for the HSF1 protein and HSF1 RNAi, using the anti-Myc antibody to detect the HSF1 protein (upper panel) and the anti-tubulin antibody (lower panel). Co-expression of the HSF1 RNAi almost completely knocks down expression of the HSF1 protein. B-E, light microscopic images of the compound eye morphologies of the 17-AAG (5 μm)-treated MJDtr-Q78S flies expressing the MJDtr-Q78 protein alone (D) or co-expressing the HSF1 RNAi (E). Untreated MJDtr-Q78S flies expressing the MJDtr-Q78 protein alone (B) or co-expressing the HSF1 RNAi (C) are also shown. Co-expression of the HSF1 RNAi almost completely abolished the therapeutic effect of 17-AAG on compound eye degeneration in the MJDtr-Q78S flies. Fly genotypes are gmr-GAL4/+, UAS-MJDtr-Q78S/+, +/+ (B and D) or gmr-GAL4/+, UAS-MJDtr-Q78S/+, and UAS-HSF1-RNAi/+ (C and E). F, real time quantitative RT-PCR analyses of Hsp70 mRNA expressed in the eye-antennal discs of the 17-AAG (5 μm)-treated MJDtr-Q78S fly larvae co-expressing the HSF1 RNAi or expressing the MJDtr-Q78 protein alone. Flies expressing the GAL4 activator protein alone (control, Cont) exposed to heat shock (HS) were used as a positive control. Co-expression of the HSF1 RNAi decreased the expression level of Hsp70 mRNA in the 17-AAG-treated MJDtr-Q78S fly larvae from 2.37- to 0.68-fold. The experiments were repeated at least four times except for control flies. The results from representative experiments are shown for control flies. The data are expressed as the means ± S.E. (n ≥ 3). *, p < 0.01 (Student's t test). Fly genotypes are gmr-GAL4/+, UAS-MJDtr-Q78S/+ (MJDtr-Q78S), gmr-GAL4/+, UAS-MJDtr-Q78S/UAS-HSF1-RNAi (MJDtr-Q78S/HSF1 RNAi), or gmr-GAL4/+ (Cont).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Ross, C. A., and Poirier, M. A. (2005) Nat. Rev. Mol. Cell Biol. 6 891-898 - PubMed
    1. Gusella, J. F., and MacDonald, M. E. (2000) Nat. Rev. Neurosci. 1 109-115 - PubMed
    1. Zoghbi, H. Y., and Orr, H. T. (2000) Annu. Rev. Neurosci. 23 217-247 - PubMed
    1. Bence, N. F., Sampat, R. M., and Kopito, R. R. (2001) Science 292 1552-1555 - PubMed
    1. Nagai, Y., Onodera, O., Chun, J., Strittmatter, W. J., and Burke, J. R. (1999) Exp. Neurol. 155 195-203 - PubMed

Publication types

MeSH terms

LinkOut - more resources