Dawan NewsOn February 29, 2024, the High-tech Research and Development Center (Basic Research Management Center) of the National Natural Science Commission released the top ten scientific advances in China in 2023.
Light is the source power of life, and it is also one of the most important perceptual inputs of living organisms. Light not only provides people with visual image perception, but also regulates a series of physiological and pathological functions such as circadian rhythm, sleep, and mood. A number of public health studies at home and abroad have shown that excessive light exposure at night significantly increases the risk of metabolic diseases such as diabetes and obesity. However, whether light can directly regulate blood glucose metabolism and what biological mechanism it uses to achieve it are important scientific questions that have not yet been solved.
Professor Xue Tian's research team at the University of Science and Technology of China discovered that light directly activates special photoreceptor cells in the eye, transmits signals through the optic nerve to the nerve nuclei of the hypothalamus and medulla, and finally acts on the brown adipose tissue in the periphery through the sympathetic nerve, inhibiting its ability to consume blood sugar (Fig). The research results were published in the internationally renowned journal "Cell".
Figure "Eye-brain-brown fat axis" mediates the neural mechanism of light regulation of blood glucose metabolism.
Light passes through the retinal intrinsic photosensitive ganglion cells (IPRGCs), transmits light information to the supraoptic nucleus of the hypothalamus (SON), then to the hypothalamic paraventricular nucleus (PVN), the solitary tract nucleus of the brainstem (NTS), to the median slit pallilose nucleus (RPA), and finally to the brown adipose tissue innervated by the sympathetic nerve. Light through this long-range "eye-brain-brown fat axis" neural connection inhibits the thermogenesis caused by the consumption of blood glucose by adipose tissue, resulting in an excessive increase in blood glucose, resulting in a decrease in blood glucose metabolism in humans and mice.
This study discovered a new "eye-brain-peripheral brown fat" pathway, answered the long-unknown biological mechanism of photoregulation of blood glucose metabolism, and expanded the new function of photosensory regulation of life processes. It is suggested that modern people should pay attention to a healthy light environment, and the wavelength, intensity and exposure duration of night light should be controlled in view of the increased risk of metabolic diseases caused by light pollution at night. The photoreceptor cells, neural circuits and peripheral target organs discovered in this work provide a theoretical basis and potential intervention strategies for the prevention and treatment of glucose metabolism disorders caused by light pollution.
"Ten Advances in Science in China" aims to publicize the scientific progress of China's major basic research, stimulate the scientific enthusiasm and dedication of the majority of scientific and technological workers, carry out the popularization of basic research, promote public understanding, care and support for basic research, and create a good scientific atmosphere in the whole society. Since 2010, a total of 12 achievements led by USTC have been selected for this progress.
Dawan News reporter Chen Mu and intern Yang Shuchun.
Edited by Xu Dapeng.