CD34+ membranous cell-entangled complexes and ultrastructural evidence of their integrative properties in the fascia system of rats and other species

The fascia system represents body-wide continuity and hypothesized communication, yet its underlying cellular mechanisms remain unclear. A recent study identified CD34 + membranous cells (CMCs) with mechanosensitive and communication properties in the subcutaneous fascia of the rat abdominal midline. The present study further explored that CMCs frequently associate with or accompany nerves, blood vessels, immunocytes, and/or extracellular vesicles, forming novel structural units termed CMC-entangled complexes (CECs) across subcutaneous, deep, and visceral fascial networks in different animal species. Laminar CMCs in the CECs often incompletely enclose hair follicles, intestinal crypts, nerves, blood vessels, and fiber bundles, indicating the formation of different microenvironments in various organs. Extracellular matrix-associated CECs interlock CMCs with the matrix and its fibers to form a special linkage structure in the fascia. Collectively, CECs represent recurrent ultrastructural organizations in which CMCs are positioned in close spatial association with nerves, blood vessels, immunocytes, extracellular vesicles, and/or matrix fibers, morphologically revealing frequent structural associations within the fascia system.