Single cell transcriptomic analysis reveals dynamic cellular composition changes at acupuncture point BL23 (Shenshu) in low back pain

The cellular and molecular mechanisms of acupuncture have been investigated across various tissues in multiple animal models. However, the dynamic cellular and molecular changes at human acupuncture points remain unexplored. The primary challenge preventing such a study is the practical difficulty of obtaining sufficient cells from acupoints. To address this, we developed a new needle manipulation technique that enables the collection of sufficient cell number from the acupuncture needle during the treatment. Using this approach and single-cell technology, we identified eight cell types at the acupoint BL23: inflammatory fibroblast, myofibroblast, skeletal muscle cell, endothelial cell, smooth muscle cell, adipocyte, macrophage, and a novel cell type characterized by marker genes <i>CNTNAP2</i> and <i>CSMD1</i>. Remarkably, this novel cell population was significantly enriched during the pain relief phase compared to the pain state, while the other seven cell types were significantly reduced following acupuncture analgesia. Transcriptomic analysis suggested that these novel cells are involved in synapse assembly and synaptic plasticity. This study presents the first characterization of cellular and transcriptional dynamics at the acupoint BL23, offering new insights into the mechanism underlying acupuncture-induced pain relief.