Cytosolic Ca2+ dynamics in normal and pathological human cells

.ROSSI, JUAN PABLO F.C.; M. VIGIL1, M. ONTIVEROS1, D. RINALDI1, M. V. ESPELT1, I. MANGIALAVORI1, O. REY2, J. P. ROSSI1, M. FERREIRA-GOMES1

LA PLATA

Congreso; XLVII Reunión Anual de la Sociedad de Biofísica Argentina. La Plata; 2018

SOCIEDAD ARGENTINA DE BIOFÍSICA

Cytosolic Ca2+ dynamics in normal and pathological human cellsM. Vigil1, M.  Ontiveros1, D. Rinaldi1,M. V. Espelt1, I. Mangialavori1, O. Rey2, J.P. Rossi1, M. Ferreira-Gomes11Instituto de Química y FisicoquímicaBiológicas. ?Prof. Paladini?. Departamento de Química Biológica, Facultad deFarmacia y Bioquímica. Universidad de Buenos Aires. 2Instituto deInmunología, Genética y Metabolismo (INIGEM). Cátedra de Genética. Facultad deFarmacia y Bioquímica. Universidad de Buenos Aires. Calcium homeostasis is highly regulated in cells. Free cytosolic Ca2+([Ca2+]c), which acts as a second messenger, is crucial for awide range of biological functions. All cells must maintain a low concentrationof [Ca2+]c (~100 nM) to maintain viability, while using theirincrease as a versatile signaling pathway. Prolonged intracellular elevation ofCa2 + can trigger cell death. Evidence shows that the calciumhomeostasis is altered in cancer cells and the alteration is involved in tumoronset, angiogenesis, progression and metastasis. In this work, we characterizedthe dynamics of [Ca2+]c for different neoplastic lines SW480, CaCoand HepG2, and compare them with the normal dynamics of HEK293T cells.The dynamics of [Ca2+]c were examined by the Ca2+release from endoplasmic reticulum (ER) in the different cell lines. The cellswere loaded with fluo4 or fura2 to measure [Ca2+]c and followed thefluorescence in real time before and after the addition of thapsigargin, aninhibitor of the sarcoplasmic reticulum calcium pump. The dynamics of [Ca2+]c in HEK293T cells showed a maximumpeak followed by an exponential decrease to the basal level. On the other hand,in the colon carcinoma cells, SW480 and CaCo, the peaks returned to a highersteady-state. In HepG2 cells, no peaks were observed but an exponentialincrease to a maximal steady-state.Then, we studied the effect of quercetin on the dynamics of [Ca2+]c.Quercetin is a flavonoid with antitumoral properties, which inhibits calciumchannels and pumps,  altering theintracellular calcium homeostasis. We observed that quercetin altered thedynamics of [Ca2+]c in SW480, CaCo, and HepG2 cells, whereas inHEK293T cells did not change. Ours results suggest that quercetin could affectthe calcium homeostasis in pathogenic cells by inhibition of Ca2+transport systems.This work reveals that the study of dynamics of [Ca2+]c couldbe used for characterizing differences in calcium homeostasis in pathogeniccells. Acknowledgments. This work was supported with grantsof ANPCYT, CONICET and UBACYT.