Calcium channels, transporters and exchangers in placenta: a review.
Calcium (Ca2+) entry in cells is crucial for development and physiology of virtually all cell types. It acts as an intracellular (second) messenger to regulate a diverse array of cellular functions, from cell division and differentiation to cell death. Among candidates for Ca2+ entry in cells are-voltage-dependant Ca2+ channels (VDCCs), transient receptor potential (TRP)-related Ca2+ channels and store-operated Ca2+ (SOC) channels. Plasma membrane Ca2+-ATPases (PMCA) and Na+/Ca2+ exchanger (NCX) are mainly responsible for Ca2+ extrusion. These different Ca2+channels/transporters and exchangers exhibit specific distribution and physiological properties. During pregnancy, the syncytiotrophoblast layer of the human placenta transfers as much as 30 g of Ca2+ from the mother to the fetus, especially in late gestation where Ca2+ transport through different channels must increase in response to the demands of accelerating bone mineralization of the fetus. The identification and characterization of the different Ca2+ channels/transporters and exchangers on the brush-border membrane (BBM) facing the maternal circulation, and the basal plasma membrane (BPM) facing the fetal circulation; placental membrane of the syncytiotrophoblasts have been the focus of numerous studies. This review discusses current views in this field regarding localization and functions during transcellular Ca2+ entry and extrusion from cells particularly in the placenta.
Belkacemi
Louiza
L
Laboratoire de Physiologie Materno-Foetale, Département des Sciences Biologiques, Université du Québec à Montréal, C.P. 8888, Succursale 'Centre-Ville'Montréal, Montréal, Québec, Canada H3C 3P8.
Bédard
Isabelle
I
Simoneau
Lucie
L
Lafond
Julie
J
D000818:Animals; D001846:Bone Development / Q000502:physiology; D015220:Calcium Channels / Q000378:metabolism / Q000502:physiology*; D020013:Calcium Signaling / Q000502:physiology*; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D005260:Female; D047109:Fetal Development / Q000502:physiology; D006801:Humans; D010920:Placenta / Q000378:metabolism / Q000502:physiology*; D011247:Pregnancy; D019831:Sodium-Calcium Exchanger / Q000378:metabolism
D015220:Calcium Channels; D002352:Carrier Proteins; D019831:Sodium-Calcium Exchanger; D000252:Calcium-Transporting ATPases