RT info:eu-repo/semantics/article T1 Delimiting CD34+ Stromal Cells/Telocytes Are Resident Mesenchymal Cells That Participate in Neovessel Formation in Skin Kaposi Sarcoma. A1 González Gómez, Miriam A1 Díaz-Flores, Lucio A1 Gutiérrez, Ricardo A1 García, Maria del Pino A1 Palmas, Marta A1 Carrasco, Jose Luis A1 Madrid, Juan Francisco A1 Díaz-Flores, Lucio Jr. K1 Kaposi sarcoma; mesenchymal/stromal cells; CD34+ stromal cells/telocytes; intussusceptive angiogenesis; intussusceptive lymphangiogenesis K1 Kaposi sarcoma K1 Mesenchymal/stromal cells K1 CD34+ stromal cells/telocytes K1 Intussusceptive angiogenesis; K1 Intussusceptive lymphangiogenesis AB Abstract: Kaposi sarcoma (KS) is an angioproliferative lesion in which two main KS cell sources are currently sustained: endothelial cells (ECs) and mesenchymal/stromal cells. Our objective is toestablish the tissue location, characteristics and transdifferentiation steps to the KS cells of the latter.For this purpose, we studied specimens of 49 cases of cutaneous KS using immunochemistry andconfocal and electron microscopy. The results showed that delimiting CD34+ stromal cells/Telocytes (CD34+SCs/TCs) in the external layer of the pre-existing blood vessels and around skin appendages form small convergent lumens, express markers for ECs of blood and lymphatic vessels, share ultrastructural characteristics with ECs and participate in the origin of two main types of neovessels, the evolution of which gives rise to lymphangiomatous or spindle-cell patterns—the substrate of the main KS histopathological variants. Intraluminal folds and pillars (papillae) are formed in the neovessels, which suggests they increase by vessel splitting (intussusceptive angiogenesis and intussusceptive lymphangiogenesis). In conclusion, delimiting CD34+SCs/TCs are mesenchymal/stromal cells that can transdifferentiate into KS ECs, participating in the formation of two types of neovessels. The subsequent growth of the latter involves intussusceptive mechanisms, originating several KS variants. These findings are of histogenic, clinical and therapeutic interest SN 1661-6596 YR 2023 FD 2023 LK http://riull.ull.es/xmlui/handle/915/35006 UL http://riull.ull.es/xmlui/handle/915/35006 LA en NO Int J Mol Sci. 2023 Feb 14;24(4):3793. doi: 10.3390/ijms24043793. PMID: 36835203; PMCID: PMC9962853.Autores: Díaz-Flores L, Gutiérrez R, González-Gómez M, García MDP, Palmas M, Carrasco JL, Madrid JF, Díaz-Flores L Jr. DS Repositorio institucional de la Universidad de La Laguna RD 21-may-2024