Changes in the mechanism of Ca2+ mobilization during the differentiation of BC3H1 muscle cells

Abstract

Ca2+ sequestration and release in BC3H1 muscle cells is strongly dependent on the stage of differentiation. In proliferating cells, more than 90% of the sequestered Ca2+ was Ins(1,4,5)P3-sensitive and 25% was caffeine-sensitive. In differentiated cells, the Ca2+ accumulation was 5-fold higher and was InsP3-insensitive, but about 60% of the sequestered Ca2+ was caffeine-sensitive. These changes were reversible upon addition of growth stimuli. Similarly, by measuring the intracellular Ca2+ concentration in single intact BC3H1 cells, it was found that the number of histamine-responsive cells decreased and the number of caffeine-responsive cells increased during muscle cell differentiation. These data indicate that the development of the muscle phenotype in BC3H1 myoblasts induces a major rearrangement of the mechanisms for Ca2+ mobilization.

Expression of the Ryanodine Receptor Type 3 Calcium Release Channel during Development and Differentiation of Mammalian Skeletal Muscle Cells

“…Studies on the structural and functional organization of intracellular calcium stores indicated that the activity of these organelles depends on a complex level of organization, including the regulated expression of the genes encoding proteins that transport calcium ions in the luminal side of these vesicles, calcium binding proteins, and calcium release channels (1). Previous studies on the composition and function of intracellular calcium stores during in vitro differentiation of skeletal muscle cells revealed that, whereas InsP 3 -sensitive stores can be present in undifferentiated and in differentiated cells, caffeine-sensitive stores can be detected only in differentiated cells (42)(43). These observations suggest that the InsP 3 receptor plays a role in regulating intracellular calcium homeostasis with respect to housekeeping activities, whereas expression and function of the skeletal muscle isoform, RyR1, have been shown to be mainly related to the functions of the differentiated muscle cells.…”

“…Myotubes-In skeletal muscle cells, calcium release through RyRs is associated with the expression of the differentiated phenotype and the regulation of muscle contraction, whereas the pathway that operates through the InsP 3 receptors appears to be independent of differentiation (42)(43). The organization of calcium stores and the expression of calcium release channels has been extensively studied using in vitro cultured cell lines and in developing and adult skeletal muscles (39, 42, 44 -46).…”

Intracellular Ca 2+ Handling in Vascular Smooth Muscle Cells Is Affected by Proliferation

“…Indeed, porcine aortic cells were passaged, and the effect of PDGF-BB was mainly translational, 33 whereas we used primary cultures, and our results indicate that regulation was pretranslational. Differentiation of muscle cell lines was also associated with changes in the caffeine sensitivity and expression of the ryanodine receptor gene, 35,36 but at that time, the various RyR isoforms were not yet described. Transforming growth factor-␤ was shown to induce the expression of RyR3 together with the release of Ca 2ϩ in response to ryanodine in mink lung epithelial cells.…”

IP3-induced tension and IP3-receptor expression in rat soleus muscle during postnatal development

“…Experiments were carried out at 22°C. natal stages studied, whereas De Smedt and colleagues (10,11) found high levels of this isoform in undifferentiated mouse skeletal muscle cell lines, which were decreased when the cells were induced to differentiate. These differences could be due to the type of preparation and/or to the animal species used and/or to a different sensitivity in the technique used, particularly in the oligonucleotide primer sequences.…”