TY - JOUR
T1 - Alterations in intracellular calcium following infection of human endothelial cells with Trypanosoma cruzi
AU - Morris, Stephen A.
AU - Tanowitz, Herbert
AU - Hatcher, Victor
AU - Bilezikian, John P.
AU - Wittner, Murray
N1 - Funding Information:
Supported in part by grants HL35882, HL20859, HL28958 and AI2770 from the National Institutes of Health.
PY - 1988/6
Y1 - 1988/6
N2 - Trypanosoma cruzi infection in cultured human umbilical vein endothelial cells increased basal cellular calcium levels from 55 to 110 nM, as monitored with the fluorescent probe, fura-2. It also influenced intracellular calcium such that consistently higher total levels were observed in response to bradykinin, angiotensin II and norepinephrine, as compared to similarly treated uninfected cells. However, bradykinin and angiotensin II-dependent increases in calcium, when considered as the absolute increment or fold elevation over basal, were significantly lower in infected endothelial cells. Infection also influenced changes in calcium levels due to agents that operate independently of plasma membrane receptors. In the presence of ionomycin, the magnitude and rate of rise of intracellular calcium were decreased; additionally the calcium peak was delayed and the subsequent decline slowed. Similar to the results with bradykinin and angiotensin II, infection decreased both the increment in and fold stimulation of intracellular calcium in response to ionomycin. In contrast, infection altered only the total calcium stimulated in response to oligomycin; neither the fold stimulation of, nor increment in intracellular calcium was affected. These results indicate that (1) infection by T. cruzi alters calcium homeostasis in endothelial cells under basal and stimulated conditions; (2) both receptor-dependent and receptor-independent mechanisms are affected by infection. The possible contribution of altered calcium homeostasis induced by T. cruzi in the pathogenesis of chagasic cardiomyopathy is considered.
AB - Trypanosoma cruzi infection in cultured human umbilical vein endothelial cells increased basal cellular calcium levels from 55 to 110 nM, as monitored with the fluorescent probe, fura-2. It also influenced intracellular calcium such that consistently higher total levels were observed in response to bradykinin, angiotensin II and norepinephrine, as compared to similarly treated uninfected cells. However, bradykinin and angiotensin II-dependent increases in calcium, when considered as the absolute increment or fold elevation over basal, were significantly lower in infected endothelial cells. Infection also influenced changes in calcium levels due to agents that operate independently of plasma membrane receptors. In the presence of ionomycin, the magnitude and rate of rise of intracellular calcium were decreased; additionally the calcium peak was delayed and the subsequent decline slowed. Similar to the results with bradykinin and angiotensin II, infection decreased both the increment in and fold stimulation of intracellular calcium in response to ionomycin. In contrast, infection altered only the total calcium stimulated in response to oligomycin; neither the fold stimulation of, nor increment in intracellular calcium was affected. These results indicate that (1) infection by T. cruzi alters calcium homeostasis in endothelial cells under basal and stimulated conditions; (2) both receptor-dependent and receptor-independent mechanisms are affected by infection. The possible contribution of altered calcium homeostasis induced by T. cruzi in the pathogenesis of chagasic cardiomyopathy is considered.
KW - Endothelial cell
KW - Intracellular calcium
KW - Trypanosoma cruzi
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U2 - 10.1016/0166-6851(88)90076-X
DO - 10.1016/0166-6851(88)90076-X
M3 - Article
C2 - 3045542
AN - SCOPUS:0023890817
SN - 0166-6851
VL - 29
SP - 213
EP - 221
JO - Molecular and Biochemical Parasitology
JF - Molecular and Biochemical Parasitology
IS - 2-3
ER -