Cell Volume Regulatory Ion Transport in the Regulation of Cell Migration

Abstract

Cell migration is typically accomplished by the generation of protrusive mechanical forces and is achieved by repeated spatially and temporally coordinated cycles including the formation of a leading edge, the formation of new and disruption of older adhesions to the substratum, actomyosin based contractions and retraction of the trailing edge. Beside the well-described roles of the cytoskeleton and cell adhesions during these processes, a growing body of evidence indicates that the precise regulation of the cell volume is an indispensable prerequisite for coordinated cell migration. On the one hand during cell migration cell volume is continuously tormented by mechanical and morphological alterations, which pose changes to the intracellular hydrostatic pressure, metabolic changes and the formation or degradation of macromolecules like actin, which distort the osmotic equilibrium and the action of chemoattractants, hormones and transmitters, which frequently alter the electrical properties of a cell and thus cause cell swelling or shrinkage, respectively. On the other hand, a migrating cell actively has to govern cell volume regulatory ion transport mechanisms in order to create the appropriate micro- or even nanoenvironment in the intra- and/or extracellular space, which is necessary to guarantee the correct polarity and hence direction of movement of a migrating cell. This chapter will focus on the role of the cell volume regulatory ion transport mechanisms as they participate in the regulation of cell migration and special emphasis is given to their interplay with the cytoskeleton, their meaning for substrate adhesion and to the polarized fashion of their subcellular distribution.

Voltage-activated ion channels and Ca2+-induced Ca2+ release shape Ca2+ signaling in Merkel cells

“…The Ca 2+ transients we observe in Merkel cells reflects a balance between Ca 2+ influx, release from stores, and sequestration by buffering and extrusion [69]. These processes are all modulated by Ca 2+ [69] [70,71].…”

Chloride Channel Blockers Suppress Formation of Engulfment Pseudopodia in Microglial Cells

“…Since all blockers used in the present study suppress at least Cl - -channel activity [3,22,37,39] and lamellipodium formation, we conclude that Cl - -channels contribute significantly in lamellipodium formation. In addition, these ion transport mechanisms are tightly linked to the cytoskeleton and hence regulate the dynamics for adhesion and pseudopodia protrusion [40,41,42]. Whether a similar polarized distribution of ion channels and transporters is established during the formation of engulfment pseudopodia is, however, not known yet.…”

LSm4 Associates with the Plasma Membrane and Acts as a Co-factor in Cell Volume Regulation

“…Cell volume regulation is essential for the maintenance of cellular homoeostasis, and is involved in important physiological processes like cell migration [1], cell proliferation [2], or apoptosis [3], amongst others. There is mounting evidence that cell volume regulatory mechanisms, and specifically the swelling dependent anion and osmolyte channel IClswell may be exploited for the therapy of pathophysiological events, for example in the heart [4,5], in exercise induced asthma [6], viral 580 infections [7], pulmonary hypertension [8], ulcers [9], or cancer [10].…”