In the human organism, each of the cells has a strictly defined set of functions, and, therefore, the existence of such a harmonious system would not be possible with the loss of any of them. Stromal cells are the critical multipotent units of structural systems of most tissues since when differentiation is completed, stromal cells can play the role of connective tissue of any organ. In general, this type of cell is most often found in the bone marrow, which means that stromal cells have an immune-directed orientation.
On the other hand, animal cells in tissues are rarely arranged chaotically, on the contrary, they form a structurally cohesive system that ensures interaction: the extracellular matrix. This term should be understood as the basis of connective tissue, which allows the implementation of mechanical support of cells and the transport of chemical substances. Since the extracellular matrix is primarily formed from connective tissue cells, it is pertinent to note that stromal cells are fundamental to the construction of the 3D matrix (Andreeva & Matveeva, 2018). More specifically, the presence of multipotent cells in the rigid matrix allows dynamic remodeling of the 3D structure of the extracellular basal plate. This has been confirmed by artificially culturing the extracellular matrix containing trace amounts of stromal cells as a result (Rakian et al., 2015). Such cells can be located in the matrix either freely or, more often, attached via integrins. The components of the extracellular matrix (produced proteins) are synthesized directly to the stromal cells and then released outside by exocytosis. This makes it possible not only to form a matrix from scratch but also to supplement the existing structure with additional elements. In addition, stromal cells are responsible for the production of solubility factors, which allows the extracellular matrix to maintain a concentration gradient and thus ensure efficient transport of molecules.
References
Andreeva, E. R., & Matveeva, D. K. (2018). Multipotent mesenchymal stromal cells and extracellular matrix: regulation under hypoxia. Human Physiology, 44(6), 696-705.
Rakian, R., Block, T. J., Johnson, S. M., Marinkovic, M., Wu, J., Dai, Q.,… & Chen, X. D. (2015). Native extracellular matrix preserves mesenchymal stem cell “stemness” and differentiation potential under serum-free culture conditions. Stem Cell Research & Therapy, 6(1), 1-11.