Testicular telocytes: a new player in cell biology of testis

Background Telocytes (TCs) are a recently identified population of interstitial cells distinguished by their long, thin cytoplasmic extensions known as telopodes. Since their initial discovery, TCs have been reported in various organs of the body, where they are involved in tissue organization, intercellular communication, and microenvironmental regulation. In the male reproductive system, the identification of TCs within the testicular interstitium has generated growing scientific interest due to their potential roles in testicular structure, function, and homeostasis. However, a comprehensive synthesis of current knowledge on testicular telocytes remains limited. Main text This review summarizes the existing literature on testicular telocytes, focusing on their morphological features, ultrastructural characteristics, immunophenotypic profiles, and anatomical localization within the testis. It discusses their interactions with key testicular components, including Leydig cells, Sertoli cells, immune cells, blood vessels, and extracellular matrix, highlighting their potential roles in intercellular signaling, tissue organization, and maintenance of the testicular microenvironment. The review also presents a comparative analysis of testicular telocytes across different species, emphasizing both conserved and species specific structural and functional characteristics. In addition, emerging evidence regarding their involvement in testicular development, physiological regulation, and pathological conditions is critically discussed, providing insights into their possible biological and clinical significance. Conclusions Testicular telocytes constitute a distinct and important cellular component of the testicular interstitium, characterized by unique structural and functional properties. Their strategic localization and extensive cellular networks suggest a key role in maintaining testicular architecture and supporting normal reproductive function. Although current evidence highlights their biological relevance, further experimental and translational studies are required to clarify their precise mechanisms of action and to explore their potential implications in male infertility, testicular diseases, and regenerative medicine.