A Guide to Pericyte Markers

Pericytes are perivascular, contractile, and multipotent cells that wrap around capillaries and venules, where they play important roles in vascular development, architecture, and permeability. These specialized cells interact closely with endothelial cells to maintain microvascular integrity, regulate blood flow, and support tissue repair, and angiogenesis. The loss or dysfunction of pericytes contributes to microvascular fragility, contributing to ischemic, fibrotic, neurodegenerative, and metabolic diseases, as well as tumor progression. Because of their broad physiological and pathological roles, pericytes are increasingly recognized as key regulators of vascular homeostasis and as potential therapeutic targets. Here, we highlight common markers to support the study and characterization of pericytes.

Challenges in defining pericyte markers

Defining pericyte-specific markers is a known challenge in the field due to the cell type’s heterogeneity and plasticity. Pericytes are highly dynamic, displaying context-dependent expression patterns that vary with tissue type, developmental stage, and pathological state. Their isolation is technically difficult, and dissociation from their native microenvironment often induces phenotypic alterations that can obscure their molecular identity. Pericytes also often exhibit an overlap in marker expression with other mesenchymal-derived cells, such as smooth muscle cells and mesenchymal stem cells. This shared lineage leads to the expression of common antigens, making it difficult to precisely define specific pericyte populations. There is yet to be a known marker that is unique to pericytes alone.

Pericytes are able to trans-differentiate into other mesenchymal cell types, including myogenic, osteogenic, chondrogenic, adipogenic, and even neural phenotypes, further complicating the establishment of fixed markers. Multiple markers may be co-expressed on a single pericyte, and their relative abundance can shift during activation, injury, or disease. As a result, different research groups studying the same tissue have reported conflicting antigenic profiles. This reflects not only biological variability but also methodological differences in isolation and labeling techniques. While there is no single, universal panel of markers for defining pericytes, differential co-immunostaining approaches using multiple markers provide a practical means for characterizing pericyte subtypes.

Common pericyte markers

A diverse panel of molecular markers has become widely used to identify pericytes across tissues and organs. Platelet-derived growth factor receptor β (PDGFRB) is a major pericyte marker involved in neurovascular function and development, including the recruitment of pericytes during embryonic angiogenesis. α-smooth muscle actin (ACTA2/αSMA), associated with capillary pericytes, plays a regulatory role in contraction and relaxation. Chondroitin sulfate proteoglycan 4 (CSPG4/NG2) is used to mark arteriolar and capillary pericytes. Regulator of G-protein signaling 5 (RGS5) is believed to function in tumor and embryonic angiogenesis. Aminopeptidase N (ANPEP/CD13) is a membrane-bound metalloprotease associated with brain pericytes. Desmin (DES) is a cytoplasmic marker that, along with NG2 and αSMA, varies in expression according to the vascular site. Melanoma cell adhesion molecule (MCAM/CD146) is a membrane marker found in capillary pericytes. Other commonly used pericyte markers include KCNJ8, ABCC9, NOTCH3, TAGLN, and MYH11.

Variations in pericyte functions and locations

Pericyte activation refers to the phenotypic transition of pericytes from a quiescent, vessel-stabilizing state to an active, proliferative, and migratory state that supports vascular remodeling and tissue repair. Upon stimulation by angiogenic cues, activated pericytes express distinct markers that differentiate them from their resting counterparts. RGS5 is one of the most consistent indicators of pericyte activation, frequently upregulated in both developmental and pathological angiogenesis. Other markers, such as endosialin (CD248) and vimentin (VIM), are associated with activated pericytes involved in vascular remodeling and fibrosis. In contrast, CSPG4/NG2 and delta-like 1 homolog (DLK1) are more characteristic of quiescent pericytes that contribute to vessel stability.

Pericytes have been categorized into subtypes based on their location along the vascular tree. Capillary pericytes (type I), characterized by the expression pattern NG2⁺/Desmin⁻/αSMA⁻, are typically found along small capillaries, where they play key roles in maintaining endothelial stability and regulating microvascular permeability. Pre-capillary pericytes (type II), defined by NG2⁺/Desmin⁺/αSMA⁺ expression, are located at the transition zones between arterioles and capillaries and exhibit greater contractile capacity, contributing to blood flow regulation and vessel remodeling. Post-capillary pericytes (type III), which are NG2⁻/αSMA⁺, are found near venules and are more actively involved in inflammatory responses and leukocyte trafficking.

Overcoming marker limitations

Addressing the limitations of current pericyte markers requires rigorous experimental design and the integration of complementary approaches. Because many pericyte markers are also expressed by other cell types, careful controls must be implemented to exclude contaminating populations. In animal models, findings should be confirmed using in vitro or ex vivo assays, where controlled environments enable direct assessment of pericyte behavior. Consistent phenotypic or functional changes observed across these models will provide stronger evidence for marker reliability.

The use of multi-omics technologies, particularly single-cell RNA sequencing (scRNA-seq), provides another means of delineating pericyte heterogeneity. Single-cell transcriptomics enables the high-resolution identification of pericyte subpopulations and their spatial distribution within the vascular niche, revealing organ-specific phenotypes and previously unrecognized markers. Emerging single-cell proteomic and epigenomic methods further expand this framework, allowing researchers to map pericyte heterogeneity at the protein and chromatin levels. Together, these tools offer a path toward refining pericyte classification, improving marker specificity, and establishing a more comprehensive understanding of pericyte identity across tissues and physiological contexts.

Table of pericyte markers

The table below highlights protein markers of pericytes reported in recent literature for identifying and characterizing distinct pericyte subpopulations. Each marker entry includes links to relevant antibody and assay products commonly used in immunodetection and molecular profiling studies. When applied in combination, these markers serve as a valuable reference for confirming pericyte identity, evaluating activation or differentiation states, and isolating specific pericyte populations in experimental models.

References

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Zhu S, Chen M, Ying Y, et al. Versatile subtypes of pericytes and their roles in spinal cord injury repair, bone development and repair. Bone Res. 2022;10(1):30. Published 2022 Mar 16. doi:10.1038/s41413-022-00203-2

Yao Y. Challenges in Pericyte Research: Pericyte-Specific and Subtype-Specific Markers. Transl Stroke Res. 2022;13(6):863-865. doi:10.1007/s12975-022-01018-3

Alvino VV, Mohammed KAK, Gu Y, Madeddu P. Approaches for the isolation and long-term expansion of pericytes from human and animal tissues. Front Cardiovasc Med. 2023;9:1095141. Published 2023 Jan 10. doi:10.3389/fcvm.2022.1095141

Dabravolski SA, Andreeva ER, Eremin II, et al. The Role of Pericytes in Regulation of Innate and Adaptive Immunity. Biomedicines. 2023;11(2):600. Published 2023 Feb 17. doi:10.3390/biomedicines11020600

van Splunder H, Villacampa P, Martínez-Romero A, Graupera M. Pericytes in the disease spotlight. Trends Cell Biol. 2024;34(1):58-71. doi:10.1016/j.tcb.2023.06.001

Oscar Franzén, Li-Ming Gan, Johan L M Björkegren. PanglaoDB: a web server for exploration of mouse and human single-cell RNA sequencing data. Database, Volume 2019, 2019, baz046, doi.org/10.1093/database/baz046

Cathery W, Faulkner A, Maselli D, Madeddu P. Concise Review: The Regenerative Journey of Pericytes Toward Clinical Translation. Stem Cells. 2018;36(9):1295-1310. doi:10.1002/stem.2846