Telocytes inside of the peripheral nervous system – a 3D endoneurial network and putative role in cell communication

Abstract

In this paper, we developed the hypothesis concerning the reasons to assimilate endoneurial fibroblast-like dendritic phenotype [shortly termed endoneurial dendritic cells (EDCs)] to the endoneurial telocytes (TCs). We reviewed the literature concerning EDCs status and report our observations on ultrastructure and some immune electron microscopic aspects of the cutaneous peripheral nerves. Our data demonstrate that EDCs long time considered as fibroblasts or fibroblast-like, with an ovoidal nucleus and one or more moniliform cell extensions [telopodes (Tps)], which perform homocellular junctions, also able to shed extracellular microvesicles can be assimilated to TC phenotype. Sometimes, small profiles of basement membrane accompany to some extent Tps. Altogether data resulted from scientific literature and our results strength the conclusion EDCs are really TCs inside of the peripheral nervous system. The inner three-dimensional (3D) network of endoneurial TCs by their homo-and heterocellular communications appears as a genuine cell-to-cell communication system inside of each peripheral nerve.

Single‐cell RNA sequencing reveals telocytes subsets of human lung

“…49 Telopode (Tps) was considered crucial for the cell junction formation between TCs and other types of cells. 50 Tps was significant in TCs dominated cell-cell communication. 51 Research showed that TCs co-cultured with peritoneal macrophages could inhibit apoptosis through paracrine effects.…”

The Osteopath’s Imprint: Osteopathic Medicine Under the Nanoscopic Lens

“…Telocytes (interstitial or stromal cells), are present throughout the body, can communicate through long “tentacles” that reach between tens and hundreds of micrometers, called telopods [ 32 ]. Telopods touch not only other telocytes but cells of different nature, close and distant [ 33 ]. Nanotunnels allow to transport different biochemicals and extracellular vesicles for the regulation of cellular morphogenesis, regeneration and metabolism, and influence the function toward a physiological or pathological environment [ 34 ].…”

Morphologies and potential roles of telocytes in nervous tissue

“…Moreover, TCs have also been observed in tumour tissues such as breast tumour and basal cell carcinoma, possibly playing roles in promoting invasive behaviour of microtumours. 65,66…”

“…Particularly, TCs have also been documented to be involved in regenerative processes due to their tandem with SCs in a variety of organs, such as aorta, 53 eye, 54 heart, 3,55,56 liver, 57,58 lungs, 38,39,59 skeletal muscles, 60–62 skin, 47 meninges and choroid plexus, 41,63,64 which are tissues contiguous to the brain where neural SC niches are located except for typical locations (e.g., subventricular zone and/or subgranular zone). Moreover, TCs have also been observed in tumour tissues such as breast tumour and basal cell carcinoma, possibly playing roles in promoting invasive behaviour of microtumours 65,66 …”