Cellular characterization in Kaposi’s sarcoma using anti-αSMA antibodies.
CD34+ delimiting stromal cells/Telocytes are resident mesenchymal cells involved in neovessel formation in cutaneous Kaposi’s sarcoma.
Introduction
Kaposi’s sarcoma is a vascular tumor that primarily affects the skin, although it can also manifest in other organs. First described by Kaposi in 1872, the cellular origin of Kaposi’s sarcoma is debated, suggesting that it may arise from endothelial cells (EC) or mesenchymal/stromal cells. In its early stages, Kaposi’s sarcoma is considered a reactive angioproliferative lesion that may evolve into a true neoplasm. The association of the tumor with human herpes virus type 8 (HHV-8) indicates viral reprogramming of ECs, contributing to its pathogenesis.
The study explores CD34+ stromal cells/Telocytes (CD34+SCs/TCs) as possible mesenchymal precursors in Kaposi’s sarcoma. These cells, located around blood vessels and skin appendages, exhibit unique morphological features and express certain markers. Understanding their role in neovessel formation is crucial for histogenesis, therapy and experimental studies of Kaposi’s sarcoma. The research uses immunohistochemistry, immunofluorescence and electron microscopy techniques to observe tissue samples.
The role of αSMA in this article
αSmooth Muscle Actin (αSMA) is a marker used to distinguish preexisting blood vessel layers and neovessels in Kaposi’s sarcoma lesions. The αSMA antibody allows clear identification of the three structural layers of normal blood vessels: the intimal layer composed of CD34+ endothelial cells, the middle layer formed by pericytes or αSMA+ smooth muscle cells, and the outer layer bounded by CD34+SCs/TCs (telocytes). This distinction is key to understanding the transition from CD34+SCs/TCs to neovessel ECs.
In the context of Kaposi’s sarcoma, the presence of αSMA in the pericytes and smooth muscle cells of preexisting vessels provides clues to the pathophysiology of the disease. Neovessels, characterized by the absence of αSMA and pericytes, show significant structural differences from normal blood vessels. This difference is of great importance for clinical evaluation and the development of therapeutic strategies aimed at interrupting the pathological angiogenesis observed in Kaposi’s sarcoma.
A monoclonal antibody for the detection of αSMA in tissue
Detection and quantification of αSMA was a necessary step to characterize pericyte and smooth muscle cells associated with pre-existing blood vessels in early Kaposi’s sarcoma lesions. For this purpose, the anti-αSMA antibody (ABK1-A8914) from Abyntek Research Reagents was used. Immunohistochemistry and immunofluorescence techniques allowed visualization and quantification of αSMA-expressing cells, revealing significant differences in the distribution and abundance of these cells between pre-existing vessels and neovessels at different stages of Kaposi’s sarcoma.
For more than 15 years, Abyntek Biopharma has provided guidance in numerous research studies to select the most appropriate biological reagent to ensure desired results in the biomarkers analyzed. In addition to sharing its knowledge and expertise to support research, the biopharmaceutical company offers the wide range of high-quality products from its Abyntek Research Reagents line, specifically designed to meet the needs of researchers involved in studies such as this one.
Conclusion
This study identifies CD34+SCs/TCs as participants in neovessel formation in Kaposi’s sarcoma, acting as resident mesenchymal or stromal cells that can transdifferentiate into neovessel endothelial cells. These cells actively participate in the transition to neovessel ECs in the early stages of Kaposi’s sarcoma, marked by the expression of blood and lymphatic vessel markers.
In addition, the formation of two main types of neovessels evolving into progressive sarcomatous lesions was observed, highlighting their distinctive morphological features and their relationship to the pathogenesis and evolution of Kaposi’s sarcoma. This work underscores the importance of CD34+SCs/TCs in the pathological angiogenesis of Kaposi’s sarcoma and suggests future clinical and therapeutic implications in the management of this disease.
These results were published in the International Journal of Molecular Sciences on February 14, 2023.
