Intercellular communication between bone cells through osteocyte dendritic network boosts bone formation

Osteocytes are confined to a mineralized bone matrix, and individual osteocytes are spatially separated and interconnected by their dendritic network. Through this network, osteocytes communicate with one another to maintain homeostasis. However, the physical size of the exchanged signaling elements is too small, making it difficult to observe their movement direction and speed in real time. Here, we construct the osteocyte dendritic network and visualize intercellular communication between osteocytes, including mitochondrial transfer from donor to recipient osteocytes. This mitochondrial transfer through the dendritic network is direct evidence of osteocyte-to-osteocyte intercellular communication, and the transferred mitochondria metabolically support the recipient osteocytes. Our results demonstrate visualization of osteocyte dendritic connections and intercellular communication. We anticipate that our study will help inform the therapeutic strategy for targeting fragile cells by revealing the direction of communication in response to energy demands in bone cells.