Studies in mammal models show that reduced sleep is associated with increased food intake. Zebrafish (Danio rerio) is emerging as a promising model for studying sleep and feeding behaviour due to its Show more
Studies in mammal models show that reduced sleep is associated with increased food intake. Zebrafish (Danio rerio) is emerging as a promising model for studying sleep and feeding behaviour due to its similarities with mammals. Our goal was to investigate whether sleep restriction increases food intake in zebrafish, its potential effects on central regulation of feeding, and whether effects are similar in both sexes. Individually housed male and female adult zebrafish were exposed to nighttime (ND) or daytime (DD) vibrations and compared to a control group without vibration (n = 30 males and n = 27 females). ND, but not DD, reduced sleep during the disturbance period, with males showing a significant effect and females exhibiting an altered sleep pattern without a statistically significant reduction. ND also significantly increased food intake in males, as measured by daily milligrammes and number of pellets consumed. In contrast, ND females exhibited a decrease in the time spent feeding, suggesting a sex-specific response to sleep disruption. The whole brain expression of neuropeptide Y (npy), proopiomelanocortin (pomc), and its receptor melanocortin-4 (mc4r) were analysed by RT-qPCR. Males from ND exhibited significantly reduced pomc mRNA levels. Grouped-housed (three male and two female) zebrafish exposed to ND also exhibited increased food intake. In conclusion, sleep restriction affected food intake behaviour and the central regulation in zebrafish, with distinct sex-specific effects. Show less
Neuroblastoma (NB) is a heterogeneous cancer of the sympathetic nervous system, which accounts for 7-10% of paediatric malignancies worldwide. Due to the lack of targetable molecular aberrations in NB Show more
Neuroblastoma (NB) is a heterogeneous cancer of the sympathetic nervous system, which accounts for 7-10% of paediatric malignancies worldwide. Due to the lack of targetable molecular aberrations in NB, most treatment options remain relatively nonspecific. Here, we investigated the therapeutic potential of BCI, an inhibitor of DUSP1 and DUSP6, in cultured NB cells. BCI was cytotoxic in a range of NB cell lines and induced a short-lived activation of the AKT and stress-inducible MAP kinases, although ERK phosphorylation was unaffected. Furthermore, a phosphoproteomic screen identified significant upregulation of JNK signalling components and suppression in mTOR and R6K signalling. To assess the specificity of BCI, CRISPR-Cas9 was employed to introduce insertions and deletions in the DUSP1 and DUSP6 genes. Surprisingly, BCI remained fully cytotoxic in NB cells with complete loss of DUSP6 and partial depletion of DUSP1, suggesting that BCI exerts cytotoxicity in NB cells through a complex mechanism that is unrelated to these phosphatases. Overall, these data highlight the risk of using an inhibitor such as BCI as supposedly specific DUSP1/6, without understanding its full range of targets in cancer cells. Show less