Fig. 2: Pro-inflammatory upd3 produced from oenocytes mediates arrhythmia.
a Venn diagram showing the number of the predicted secretory proteins that are differentially expressed (≥2-fold, FDR < 0.05) under aging and paraquat treatment. Aging and paraquat RNA-Seq data were from our previous studies. Fly ages: 10-day-old vs. 30-day-old. b Genetic screening on 27 candidate genes for their role in paraquat-induced arrhythmia. WT: Wild-type (attP2 or attP40 RNAi control lines). For statistical numbers, refer to the Methods section. c PQ-induced arrhythmia measured by SOHA for two independent upd3 RNAi lines under oenocyte-specific GeneSwitch driver (PromEGS-Gal4). Ctrl genotype is PromE>attP40. (nleft-right = 20, 18, 23, 17, 22, 18 flies). d Relative mRNA expression of upd1, upd2 and upd3 from isolated oenocytes at ages of 1 week or 4 weeks. N = 3 biologically independent samples. e Relative mRNA expression of upd3 in different tissues dissected from young (1 week) and old (6 weeks) female flies. FB: fat body, OV: ovary, oe: oenocytes. N = 4 biological samples, results pooled from 2 independent experiments. f PQ-induced arrhythmia measured by SOHA for upd3 RNAi under fat body/gut-specific GeneSwitch driver, (nleft-right = 52, 27, 17, 18 flies). g Representative M-mode traces of wild-type and oenocyte-specific upd3 knockdown flies at young and old ages. h Arrhythmia index of wild-type and oenocyte-specific upd3 knockdown flies. Two independent RNAi lines used. Ctrl genotype is PromE>attP40, (nleft-right = 14, 17, 19, 20, 18, 19 flies). i Arrhythmia index for flies with ectopic upd3 expression (UAS-upd3-GFP) specifically in oenocytes. Flies are 1-week-old. Ctrl genotype is PromE>attP40 (nleft-right = 22, 28 flies). j Arrhythmia index of flies overexpressing upd3 in fat body and gut (S106GS-Gal4), nleft-right = 16, 17 flies. k Arrhythmia index of flies overexpressing upd3 in the heart (Hand-Gal4), nleft-right = 16, 21 flies. Data are represented as mean ± SEM. P values are calculated using two-tailed unpaired t-test (i–k), one-way ANOVA (b), or two-way ANOVA (c–f, h) followed by Holm-Sidak multiple comparisons. ns: not significant.
