Figure 4

From: The NAD World 2.0: the importance of the inter-tissue communication mediated by NAMPT/NAD+/SIRT1 in mammalian aging and longevity control

Figure 4

The concept of the NAD World 2.0. The original concept of the NAD World is now reformulated as the NAD World 2.0, with an emphasis on the importance of the inter-tissue communication between three key organs and tissues, namely, the hypothalamus as the control center of aging/controller, skeletal muscle as an effector/actuator, and adipose tissue as a modulator/possible sensor (both biological and engineering terms are described in parallel). Cooperative functions of SIRT1 and NAMPT, both iNAMPT and eNAMPT, play a crucial role in regulating the system dynamics of this inter-tissue communications. The NAD World 2.0 as a control system provides new insights into the regulation of biological robustness and fragility in mammalian aging and longevity control. See text for details.