Fig. 2: UA induces acid ceramidase (asah-1) expression to promote neuronal health.
From: An intestinal sphingolipid confers intergenerational neuroprotection
a, RNAi-mediated knockdown of rme-2 suppresses UA-induced reduction of PLM axon breaks in mec-17(ok2109); lon-2(e678) animals. b,c, The progeny of P0 mothers (mec-17(ok2109); lon-2(e678), hrde-1(tm1200); mec-17(ok2109); lon-2(e678) (b) and znfx-1(gg561); mec-17(ok2109); lon-2(e678) (c) animals) exposed to UA for 16 h (L4 to young adult) have reduced PLM axon breaks for two generations (F1 and F2). Experimental timing as in Fig. 1g. d, Schematic of transcriptome analysis following UA exposure (top). Total RNA was isolated from L4 larvae exposed to UA for 12 h (compared with the DMSO control). asah-1 was upregulated following UA exposure (Supplementary Table 1). The upregulation of asah-1 messenger RNA in wild-type L4 larvae after 12 h of UA exposure was independently confirmed using qPCR (bottom; n = 3 independent experiments). The housekeeping gene cdc-42 was used as the control. e,f, Loss of asah-1 by RNAi (e) or gene deletion (f) suppresses the ability of UA to reduce PLM axon breaks in mec-17(ok2109); lon-2(e678) animals. g, Representative fluorescence micrographs (top) and calculated levels (bottom) of the Pasah-1::nls::gfp transcriptional reporter. Expression was detected in the intestine from late embryogenesis through to adult (see Extended Data Fig. 4). Pasah-1::nls::gfp expression increased in animals exposed to UA for 12 h compared with the controls (DMSO); a.u. arbitrary units. Lateral views, anterior to the left, of L4 larvae are shown. Pharynx marked by a white asterisk. Scale bar, 25 μm. a–c,e–g, n = 186, 186, 162 and 154 (a); n = 90, 69, 61, 65, 71, 71, 160, 156, 145, 158, 73 and 68 (b); n = 98, 101, 99, 100, 76, 71, 115, 115, 115, 114, 116 and 121 (c); n = 126, 101, 148 and 94 (e); n = 223, 220, 202 and 194 (f); and n = 37 and 43 (g) hermaphrodite animals per condition (left to right). a–g, P values were determined using an ANOVA (a–c,e) or unpaired Student’s t-test (d,f,g). ****P ≤ 0.0001; ***P ≤ 0.001; **P ≤ 0.01; *P ≤ 0.05; and NS, not significant. Error bars indicate the s.e.m. Source data are provided.
