STAT Signaling and Its Anti-Apoptotic Effects in Dehydrated Xenopus laevis.

Xenopus laevis survives seasonal droughts by entering a hypometabolic state known as aestivation. One of the mechanisms employed by X. laevis to mitigate aestivation-induced tissue atrophy is gene regulation of pro-survival proteins. We further expand on the role of anti-apoptotic signaling in X. laevis by investigating the effect of signal transducer and activator of transcription (STAT) signaling on downstream anti-apoptotic genes in control and dehydrated liver and skeletal muscle of X. laevis. Herein, we found that STAT signaling is differentially regulated between tissues. STAT3 signaling in the liver and STAT5 signaling in skeletal muscle lead to the selective upregulation of downstream anti-apoptotic proteins. Additionally, pro-apoptotic STAT1 signaling is found to be attenuated in both tissues during dehydration stress. Overall, our results indicate an important role for anti-apoptotic proteins during dehydration stress and their contribution in mitigating aestivation-induced atrophy.