The Regulatory Factor ZFHX3 Modifies Circadian Function in SCN via an AT Motif-Driven Axis.
Bottom Line: Using RNA sequencing, we found minimal effects on core clock genes in Zfhx3(Sci/+) SCN, whereas the expression of neuropeptides critical for SCN intercellular signaling was significantly disturbed.Moreover, mutant ZFHX3 had a decreased ability to activate AT motifs in the promoters of these neuropeptide genes.Lentiviral transduction of SCN slices showed that the ZFHX3-mediated activation of AT motifs is circadian, with decreased amplitude and robustness of these oscillations in Zfhx3(Sci/+) SCN slices.
Affiliation: MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, UK.Show MeSH
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Mentions: A comparison of module 1 elements in Zfhx3Sci/+ and Zfhx3+/+ SCN revealed that 15 of 21 genes showed decreased expression in mutants. This included a number of neuropeptides and their receptors, such as: arginine vasopressin (Avp), gastrin-releasing peptide (Grp), Nms, prokineticin 2 (Prok2), Prokr2, Vip, and Vipr2. We measured their SCN mRNA expression at six time points across the light:dark cycle, using qPCR. Grp, Vip, and Vipr2 had damped mRNA expression in Zfhx3Sci/+ SCN (two-way ANOVA, genotype main effect, p < 0.05). Expression of Grp and Vip, two neuropeptides previously shown to be important for regulating the firing patterns of SCN neurons (Aton et al., 2005; Brown et al., 2005; Maywood et al., 2006;), was decreased but not absent at most time points (Figures 4A and 4B). It should be noted that Zfhx3 expression is not cyclic in the SCN, with no significant differences in mRNA expression (two-way ANOVA, time main effect, p > 0.2) and no gross differences in protein localization within the SCN between Zfhx3Sci/+ and Zfhx3+/+ animals (Figures 4C and 4D).
Affiliation: MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, UK.