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: Using immunofluorescence, we compared AVP, GRP, VIP, and VIPR2 levels in Zfhx3Sci/+ and Zfhx3+/+ SCN. We found that GRP and VIP levels, but not AVP and VIPR2 levels, were significantly decreased in Zfhx3Sci/+ at ZT6 (Figures 4E–4I). There was a small but significant decrease in Zfhx3Sci/+ SCN size compared to Zfhx3+/+ (Zfhx3Sci/+ SCN size: 53,600 ± 2,400 μm2, n = 4; Zfhx3+/+ SCN size: 66,900 ± 1,600 μm2, n = 4; p < 0.05, t test, area of DAPI signal fluorescence). The data suggest that ZFHX3 actively influences the expression of these clock-relevant neuropeptides in the adult SCN and that this activation is disrupted in Zfhx3Sci/+ mice. These differences were not primarily due to aberrant terminal differentiation, as there was no significant reduction in the number of AVP or VIP immuno-positive neurons (Figures 4J and 4K). Interestingly, ZFHX3 immuno-positive neurons almost completely overlapped with those for both AVP and VIP (Figure S3).
Affiliation: MRC Harwell, Harwell Science and Innovation Campus, Oxfordshire OX11 0RD, UK.