https://orcid.org/0000-0001-8411-626X
Figures & data
Figure 1 Green Tea Infusion does not affect overall Toxicity but ameliorates neurodegenerative Phenotypes of Flies expressing mutant Htt. A. Relative viability of flies expressing Htt with an elongated polyQ repeat (Httex1p-Q93) is significantly reduced (P=0.00379, two-way ANOVA) compared to that of control flies expressing Htt with a short polyQ repeat (Httex1p-Q20). Reduced viability of Httex1p-Q93 flies is not rescued by green tea supplementation. CM: control medium, GTM: green tea containing medium. Viability of Htt expressing flies is shown as the ratio of eclosed transgene expressing flies in percent of non-expressing control siblings, error bars represent SEM, n (vials/flies): Q20 CM=6/325, Q20 GTM=6/384, Q93 CM=6/411, Q93 GTM=7/300. B. Httex1p-Q93 flies have significantly reduced (P=6.39×10−8, two-way ANOVA) climbing ability compared to Httex1p-Q20 control siblings, and motor performance is significantly (P=0.015, two-way ANOVA) enhanced by green tea supplementation, however, this effect is not specific for Httex1p-Q93 expression. Bars show the average distance climbed vertically per seconds, error bars represent SEM. C. In the eyes of six-day-old Httex1p-Q93 expressing adults significantly fewer (P=2×10−16, two-way ANOVA) visible rhabdomeres are present per ommatidium than in similarly treated Httex1p-Q20 control. Green tea supplementation significantly ameliorates degeneration of photoreceptor neurons (P=0.01, two-way ANOVA), and this effect is specific for mutant Huntingtin (interaction P=0.0039, two-way ANOVA). Bars show the average of the average number of rhabdomeres per ommatidium in inspected eyes, error bars represent SEM. D. In the retina of Httex1p-Q93 expressing Drosophila kept on GTM medium the percentage of ommatidia with 6 or 7 intact rhabdomeres is increased compared to ommatidia of flies kept on CM medium (P=0.0076, Chi-squared test). Bars represent the frequency of ommatidia containing the indicated number of rhabdomeres. E. Representative images of retina of flies expressing mutant (HttQ93) or control (HttQ20) Huntingtin kept on CM or GTM medium. In healthy retina, seven visible rhabdomeres are present in each ommatidium.
Figure 2 Green Tea does not influence Htt Protein Levels. A representative immunoblot with antibody raised against the N-terminal part of human Htt (top panel) shows unaltered levels of mutant Htt in head extracts of Httex1p-Q93 expressing flies reared on GTM or CM (lanes 3 and 4, respectively; at least five biological replicates per treatment were inspected). In the absence of the elav-GAL4 neuronal driver (lane 2), the Httex1p-Q93 transgene is not expressed. Immunoblot with anti-α-tubulin antibody (bottom panel) serves as loading control.
Figure 3 Green Tea Infusion increases the Lifespan of mutant Huntingtin expressing Drosophila. The two graphs on top show percent survival as function of days of adult Drosophila females expressing A. Httex1p-Q20 (control) or B. Httex1p-Q93 transgenes (combined results of experiments performed at two different times are shown) in the nervous system kept on either CM or GTM. Median lifespan of Httex1p-Q93 expressing flies is significantly reduced compared to that of Httex1p-Q20 controls (P=1.8×10−54, Mann–Whitney U test). On GTM medium Httex1p-Q93 expressing flies reach 75 and 90% mortality rates significantly later than on CM (P=0.0218 and P=0.0003, respectively; Mann–Whitney U test). C. Wild-type fruit flies have a significantly (P=1.1×10−7, Two Stage Hazard Rate Comparison) shorter lifespan on GTM than on CM. The graph shows percent survival as function of days of isogenic w1118 fruit flies kept at 25°C.
