Journal: Proceedings of the National Academy of Sciences of the United States of America

Article Title: Tryptophan-2,3-dioxygenase (TDO) inhibition ameliorates neurodegeneration by modulation of kynurenine pathway metabolites

doi: 10.1073/pnas.1604453113

Figure Lengend Snippet: QUIN exacerbates neurodegeneration in HD flies and overexpression of hKAT is neuroprotective via increased KYNA levels. (A) QUIN levels in WT and HTT93Q-expressing flies. QUIN is detected in flies fed with 0.5 mg/mL of QUIN, but was not measurable in untreated flies. n = 3–5 flies per treatment, ***P < 0.001. (B) HTT93Q and cn−/− HTT93Q flies fed QUIN exhibit increased rhabdomere degeneration compared with untreated flies. Neuroprotection conferred by the cn mutation is abolished by QUIN feeding. n = 11–12 per treatment, **P < 0.01, ***P < 0.001. (C) Panneuronal overexpression of hKAT in a WT background causes an increase in KYNA production compared with controls at both posteclosion ages tested. n = 3–5 per genotype, ***P < 0.001. (D) HTT93Q flies with panneuronal overexpression of hKAT show a significant reduction in the 3-HK/KYNA ratio. The transgene control used in this experiment was a transgenic Drosophila line expressing an empty pJFRC2 vector. n = 4–5 per condition, **P < 0.01, ***P < 0.001. (E) Overexpression of hKAT is neuroprotective in HTT93Q flies at both posteclosion ages tested. n = 9–13 flies per condition, ***P < 0.001. (F) Overexpression of hKAT ameliorates the eclosion phenotype observed in HTT93Q flies. Transgene control + Htt93Q flies: n = 1084; hKAT + Htt93Q flies: n = 1,010, ***P < 0.001; ns, not significant. Data are the mean ± SEM (one-way ANOVA with Newman–Keuls post hoc test).

Article Snippet: The gene encoding kynurenine aminotransferase (hKAT) was amplified from a human fetal cDNA library ( 54 ) and cloned into the pJFRC2 vector ( 55 )—a gift from Gerald Rubin (Addgene plasmid no. 26214)—by standard methods.

Techniques: Over Expression, Expressing, Mutagenesis, Control, Transgenic Assay, Plasmid Preparation