SIRT1 and obesity due to melanocortin 4 receptor deficiency: Thus, our data unambiguously demonstrate that CAP counters diet-induced obesity in WT mice robustly at ambient temperature and in the TNZ through the PRDM16-mediated enhancement of UCP-1 transcription, as shown in Figure 9B. The HFD inhibits TRPV1, prevents Ca2+ influx and activation of kinases, and activates SIRT-1.