Telocyte Characterization by Immunohistochemistry and Ultrastructure in Normal and Diabetic Human Kidneys

Ellery Haines^*
*Correspondence: Ellery Haines, Department of Biomedical Sciences, University of Warmia and Mazury, Olsztyn, Poland, Email:

Introduction

The kidneys are essential organs that maintain homeostasis by regulating fluid and electrolyte balance, filtering waste products, and producing hormones that control blood pressure and red blood cell production. Chronic Kidney Diseases (CKD), such as diabetic nephropathy, are a significant cause of morbidity and mortality worldwide, especially in individuals with diabetes. Understanding the cellular and molecular mechanisms involved in the pathology of CKD is essential to develop targeted therapeutic interventions. One promising area of research focuses on a newly identified type of interstitial cell, the telocyte, which plays a critical role in tissue homeostasis and repair [1].

Telocytes are a distinct population of stromal cells with long, slender extensions called telopodes, which form intricate networks within various tissues, including the kidney. These cells have been implicated in several physiological processes, including intercellular communication, tissue regeneration, and repair. Telocytes are characterized by their unique ultrastructural features and can be identified using immunohistochemistry and electron microscopy. In recent years, research has demonstrated that telocytes may be affected in pathological conditions such as diabetes, raising the possibility that telocyte dysfunction could contribute to diabetic nephropathy. Characterizing telocytes in normal and diabetic human kidneys using immunohistochemistry and ultrastructural analysis provides valuable insight into their role in health and disease [2].

Description

Telocytes were first described in the early 21st century and have since been identified in numerous organs, including the heart, lungs, skin, and kidneys. In the kidney, telocytes are primarily located in the renal interstitium, where they form complex networks with other cell types, including fibroblasts, endothelial cells, and immune cells. Telocytes are thought to facilitate communication between these cells through paracrine signaling and the release of extracellular vesicles, which contain proteins, RNA, and other signaling molecules. In addition, telocytes are involved in maintaining tissue architecture and promoting repair following injury [3].

Immunohistochemistry is a widely used technique to identify telocytes in tissue sections based on their expression of specific markers. In normal kidneys, telocytes express markers such as CD34, vimentin, and PDGFR-β, which distinguish them from other interstitial cells like fibroblasts and pericytes. These markers are critical for identifying telocytes in immunohistochemical studies, as they are not universally expressed by other cell types in the renal interstitium. For example, CD34 is a glycoprotein commonly associated with hematopoietic stem cells and endothelial progenitor cells but has been shown to be expressed by telocytes in various organs. Vimentin is an intermediate filament protein expressed by mesenchymal cells, including telocytes, and is often used as a marker for identifying these cells. PDGFR-β, or platelet-derived growth factor receptor-beta, is another mesenchymal cell marker that is highly expressed by telocytes in the kidney. These markers, in combination, allow for the identification and characterization of telocytes in kidney tissue sections using immunohistochemistry [4].

The ultrastructure of telocytes is unique and can be examined using electron microscopy, which provides detailed images of their cellular architecture. One of the most distinctive features of telocytes is their telopodes, which are long, thin cytoplasmic extensions that can be several micrometers in length. Telopodes are typically characterized by alternating thick and thin segments, giving them a "beads on a string" appearance. These extensions allow telocytes to form extensive networks with other cell types in the kidney and facilitate intercellular communication. Electron microscopy has revealed that telocytes possess a small, elongated cell body containing a relatively large nucleus and sparse cytoplasm. The cytoplasm often contains mitochondria, endoplasmic reticulum, and small vesicles, which are thought to be involved in the release of signaling molecules. In normal kidneys, telocytes maintain the structural integrity of the renal interstitium and play a crucial role in tissue repair following injury [5].

Conclusion

In conclusion, telocytes are a unique population of stromal cells that play a crucial role in maintaining kidney homeostasis and promoting tissue repair. In normal kidneys, telocytes form extensive networks with other interstitial cells and regulate processes such as ECM production, fibroblast activation, and immune homeostasis. However, in diabetic kidneys, telocytes are significantly altered, which may contribute to the pathogenesis of diabetic nephropathy. The loss of telocytes in diabetic kidneys is associated with increased fibrosis, inflammation, and impaired tissue repair, which ultimately leads to renal dysfunction. Characterizing telocytes in normal and diabetic human kidneys using immunohistochemistry and ultrastructural analysis provides valuable insights into their role in health and disease. Understanding the mechanisms by which telocytes are affected in diabetes may lead to the development of targeted therapies that restore telocyte function and prevent the progression of diabetic nephropathy. Further research is needed to elucidate the precise molecular pathways involved in telocyte dysfunction in diabetic kidneys and to explore potential therapeutic strategies for restoring telocyte function in CKD.

Acknowledgement

None.

Conflict of Interest

None.

References

1. Cantarero, Irene, Maria Jose Luesma, Jose Miguel Alvarez-Dotu and Eduardo Muñoz, et al. "Transmission electron microscopy as key technique for the characterization of telocytes." Curr Stem Cell Res Therapy 11 (2016): 410-414.

Google Scholar, Crossref, Indexed at

2. Popescu, L. M., C. G. Manole, M. Gherghiceanu and A. Ardelean, et al. "Telocytes in human epicardium." J Cell Mol Med 14 (2010): 2085-2093.

Google Scholar, Crossref, Indexed at

3. Borges, Luciano Figueiredo, Rafael Souza Pereira Falcão, Sebastião Roberto Taboga and Paulo Sampaio Gutierrez, et al. "Are telocytes related to maintenance of vascular homeostasis in normal and pathological aorta?." Cardiovascular Pathol 70 (2024): 107617.

Google Scholar, Crossref, Indexed at

4. Kondo, Ayano and Klaus H. Kaestner. "Emerging diverse roles of telocytes." Develop 146 (2019): dev175018.

Google Scholar, Crossref, Indexed at

5. Manole, Catalin G., Mihaela Gherghiceanu, Laura Cristina Ceafalan and Mihail E. Hinescu. "Dermal telocytes: A different viewpoint of skin repairing and regeneration." Cells 11 (2022): 3903.

Google Scholar, Crossref, Indexed at