Surface molecules on mesenchymal stem cells (MSCs) play important roles in various aspects of MSC biology, including cell adhesion, migration, immunomodulation, and interaction with the microenvironment. These surface molecules are involved in mediating interactions with other cells, extracellular matrix (ECM) components, and signalling pathways. Surface molecules like integrins, selectins, and cadherins are essential for MSC adhesion to the ECM and to other cells. Integrins, such as α5β1 and αvβ3, are involved in the attachment of MSCs to ECM components like fibronectin and vitronectin. This adhesion to the ECM is essential for MSC survival and maintenance of their stem cell properties. Integrins also help maintain the stemness of MSCs by regulating self-renewal and preventing premature differentiation. For example, α6β1 and α9β1 integrins have been associated with the maintenance of the undifferentiated state of MSCs. Whilst MSCs do not express selectins themselves, they can interact with selectin ligands on endothelial cells or immune cells during the process of homing to inflamed tissues. This interaction may facilitate the extravasation of MSCs from the bloodstream and their recruitment to target tissues. MSCs express cell surface molecules that are involved in immune regulation. For example, programmed death-ligand 1 (PD-L1) interacts with programmed cell death protein 1 (PD-1) on T cells, leading to T cell suppression. Other surface molecules, such as Fas ligand (FasL) and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), can induce apoptosis in activated immune cells, contributing to immunomodulation by MSCs. Surface receptors, including growth factor receptors, cytokine receptors, and Toll-like receptors (TLRs), are also critical for sensing and responding to signals from the microenvironment. For example, TLRs on MSCs can recognize pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), initiating innate immune responses and modulating MSC behaviour. Surface molecules like CD9, CD63, and CD81 can be associated with the release of extracellular vesicles (EVs), including exosomes and microvesicles, from MSCs. These EVs are thought to contain bioactive molecules, such as microRNAs and proteins, which can influence neighbouring cells and mediate intercellular communication. The expression of certain surface molecules on MSCs can change with aging and cellular senescence. Such alterations in surface molecule expression can impact MSC functionality and regenerative potential. Surface molecules like CXCR4 and CCR2 are involved in chemotaxis and homing of MSCs to sites of tissue injury or inflammation. These molecules allow MSCs to migrate toward gradients of chemokines, contributing to tissue repair and regeneration. Finally, MSCs can express tissue-specific homing receptors that enable them to target specific tissues or organs. Certain integrins and chemokine receptors are involved in the preferential homing of MSCs to bone marrow, liver, or damaged cartilage. For example, integrins α4β1 (VLA-4) and αLβ2 (LFA-1) are important for MSC migration and homing to injured or inflamed tissues and are involved in the adhesion of MSCs to endothelial cells and their transendothelial migration to reach target tissues. Explore our full MSCs surface molecules product range below and discover more, for less.