Chinese scholars have discovered for the first time microglial like cells in the peripheral nervous system


  

  The development, function, and evolution of microglia in the peripheral nervous system

  Under the support of the National Natural Science Foundation of China (Grant No.: 32425024, etc.), the research team of Li Hanjie from the Chinese Academy of Sciences Shenzhen Institute of Advanced Technology cooperated with the team of Professor Chen Yun from Nanjing Medical University to make new progress in the research on the evolution of microglia. The research results were entitled "Peripheral nerve system microglia like cells can regulate neuronal soma size through evolution" and published online in Cell on April 7, 2025. Paper link: https://doi.org/10.1016/j.cell.2025.02.007 .

  As an important component of the immune system, macrophages are widely distributed in different tissues and organs, playing a crucial role in embryonic development, organ formation, homeostasis maintenance, and disease occurrence and development. Macrophage subpopulations are diverse and functionally complex. Among them, microglia, as a special member of the macrophage family, are widely involved in physiological and pathological processes such as central nervous system immune monitoring, inflammatory response, neurodevelopment, and degenerative diseases. Due to the large-scale application of rodent models, it was previously believed that microglia did not exist in the peripheral nervous system.

  Li Hanjie's research team used multidimensional research such as single-cell transcriptomics, epigenetics, characteristic protein expression, and developmental origin to identify for the first time a group of microglia cells related to species size and encapsulating neuronal bodies in the peripheral nervous system. Further functional studies have revealed the important role of peripheral nervous system microglia in neuronal cell body enlargement, axonal growth, and functional maturation. At the same time, multi species phylogenetic analysis also shows that peripheral nervous system microglia have ancient origins and are positively correlated with species body size and peripheral neuron cell size, which confirms the results of peripheral nervous system microglia regulating neuronal function mentioned above (Figure).

  This study not only proposes new immune neural interaction patterns, but also expands our understanding of the distribution and function of microglia. The discovery of microglia in the peripheral nervous system breaks through the century old notion that microglia only exist in the central nervous system, and provides a new perspective for the study of peripheral nervous system development and related diseases.