Characteristics of tunneling nanotube-like structures formed by human dermal microvascular pericytes in vitro

Tunneling nanotubes (TNTs) represent an innovative way for cells to communicate with one another, as they act as long conduits between cells. However, their roles in human dermal microvascular pericytes (HDMPCs) interaction remain elusive in vitro. In this work, we identified and characterized the TNT-like structures that connected two or more pericytes in two-dimensional cultures and formed a functional network in the human dermis. Immunofluorescence assay indicated that the F-actin was an essential element to form inter-pericyte TNT-like structures, as it decreased in actin polymer inhibitor-cytochalasin B treated groups, and microtubules were present in almost half of the TNT-like structures. Most importantly, we only found the presence of mitochondrial in TNT-like structures containing α-tubulin, and the application of microtubule assembly inhibitor-Nocodazole significantly reduced the percentage of TNT-like structures that contain α-tubulin, resulting in a sudden decrease in the positive rate of cytochrome c oxidase subunit 4 isoform 1 (COX IV, a marker of mitochondria) in TNT-like structures. In summary, we described a novel intercellular communication-TNT-like structures-between HDMPCs in vitro, and this work allows us to properly understand the cellular mechanisms of spreading materials between HDMPCs, shedding light on the role of HDMPCs.