Ligamentum arteriosum and its telocytes: An ultrastructure description

Abstract

Results from my study have shown in 2022 the existence of telocytes (TCs) in mice ligamentum arteriosum (LA). Telocytes (TCs) are unique interstitial or stromal cells of mesodermal origin, defined by long cellular extensions called telopodes (Tps) which form a network, connecting them to surrounding cells. These Tps have dilated portions named podoms (usually containing mitochondria, endoplasmic reticulum and caveolae) and very thin segments (below resolving power of light microscopy), called podomers. Generally, transmission electron microscope revealed the existence of Tps with various conformations: (a) long, flattened irregular veils (ribbon‐like segments) with knobs, corresponding to podoms, and (b) tubular structures (podomers) with uneven caliber because of irregular dilations (knobs)—the podoms. Also shown were numerous extracellular vesicles and exosomes released by the TCs which sometimes made direct contact with telopodes. Telopodes were observed communicating with each other through adherens junctions. Telopodes sandwiched between myocytes or in close proximity (0.01 μm) from nerve terminals were also observed. These data might be useful for understanding the role(s) of TCs in intercellular signaling and communication, neuromodulation as well as comprehension of pathologies like structural remodeling within the LA.

Single‐cell RNA sequencing reveals telocytes subsets of human lung

“…More importantly, the intercellular communication mediated by exosomes could also be achieved through the delivery of genetic information, such as microRNAs (miRs) 57 . Cardiac TCs inhibit cardiac microvascular endothelial cell apoptosis through exosomal miR‐21‐5p‐targeted CDIP1 silencing to improve angiogenesis following myocardial infarction 58 …”

“…57 Cardiac TCs inhibit cardiac microvascular endothelial cell apoptosis through exosomal miR-21-5p-targeted CDIP1 silencing to improve angiogenesis following myocardial infarction. 58 The LGALS1 was one of the β-galactoside-binding proteins implicated in modulating cell-cell and cell-matrix interactions. 59 Our result showed that TCs' communication with killer cells might relate to the LGALS1 gene.…”

Roles of telocytes dominated cell–cell communication in fibroproliferative acute respiratory distress syndrome

“…TCs could produce higher levels of miRNA‐21‐5p and miR‐30b after being stimulated with LPS. TC‐EVs could be absorbed by valvular interstitial cells, and miR‐30b expression in calcified valvular tissues was notably increased after EV treatment, indicating that TC‐EVs were the communication media of miRNAs 41 . Yu et al.…”

Telocytes and inflammation: A review

“…TCs are widespread in a variety of tissues and organs, such as cardiac tissues, [5,6] vessels, [7] the trachea and lungs, [8,9] gallbladder, [10] liver, [11] Intestinal tissues, [12] duodenum, [13] colon, [14] and spleen, [15] and they are also found in the male genitals including the testis, [16] and epididymis, [17] as well as the female genital organs and the uterus, [18,19] oviduct, [20] and placenta. [21] In addition, TCs are also found in the pleura, [22] skin, [1] parotid glands, [23] skeletal muscle, [24,25] and epithelium.…”