Life Extension Mechanism Of Low Temperature Induction By Autophagy In C.Elegans

There are so many factors that affect organisms survive in the nature, including the temperature of the most importantfactors. Generally, both poikilotherms and homeotherms live longer in low temperature environment than high temperature environment, highlighting a generalrole of temperature reduction in lifespan extension.However, the underlying reasons remain unclear. One of the common view is that the lower temperature makes the physiological metabolism of the animals slows, further slows down the rate of aging, and prolong the lifespan. This view simply illustrates the organisms longer of lifespan is only partly because of the environmental impact. However, there was no real elucidating the underlying mechanisms of longevity in low temperature environment. Here,it takes advantage of C.elegans as a model, a recent study found that the survival times of C.elegans in the low temperature environment of 15℃ is longer than in the.high temperature environment of 25℃, which is associated with low temperature activation TRPA-1 ion channels.Previous research has found that autophagy is one of the mechanisms which is hunger induced lifespan extension in C.elegans.This study found that the low-temperature environment of 15℃ promote nematodes autophagy increases.At the same time, we found that the low temperature activates EGL-25/NHR-49 signal, and it will increase fat-7 expression. FAT-7 activate the nuclear receptors NHR-80, by producing omega-6 polyunsaturated fatty acid (PUFA)-arachidonic acid (AA). Further, NHR-80 promote HLH-30(a TFEB homologous transcription factors in mammals) express rising and HLH-30 into the nucleus increasing. Then HLH-30 mediated autophagy, and prolong the lifespan of the C.elegans. Finally, our research also found that activation of autophagy signal in the hypothermiais independent of each other with TRPA-1 cold ions channels. To sum up, the low temperature environment activates autophagy, mediated cryogenic nematodes longivity through EGL-25/NHR-49/FAT-7/AA/NHR-80/HLH-30 signaling pathways. Thus, our study reveals a new mechanism of low temperature for the lifespan extension of C.elegans.