Polarity as a physiological modulator of cell function

Abstract

Cell polarity, the asymmetric distribution of proteins, organelles, and cytoskeleton, plays an important role in development, homeostasis, and disease. Understanding the mechanisms that govern cell polarity is critical for creating strategies to treat developmental defects, accelerate tissue regeneration, and hinder cancer progression. This review focuses on the role of cell polarity in a number of physiological processes, including asymmetric division, cell migration, immune response mediated by T lymphocytes, and cancer progression and metastasis, and highlights microfabrication techniques to systematically parse the role of microenvironmental cues in the regulation of cell polarity.

Figure 1.

Cell polarity plays a critical role in cell function. A prime example is the epithelial cells utilizing apical-basal polarity to provide a barrier function against pathogens. Another example is cell migration which requires front-to-back polarity to allow cells to adhere to and detach from the ECM. Polarity is also required for neurons to perform their task of propagating action potentials and sending messages from the central nervous system to distant body parts.

Figure 2.

Cell divisions are controlled by internal and external signals. Symmetric divisions occur when there is an equal distribution of proteins, organelles, and cytoskeleton in the mother cell resulting in two daughter cells of the same fate. Asymmetric divisions through the intrinsic mechanism have an unequal distribution of proteins and fate determinants often resulting in daughter cells with different fates. Through the extrinsic mechanism, the cell divides symmetrically but daughter cells receive different signals from the microenvironment resulting in diverse cell fates.