TY - JOUR
T1 - TOXI-SIM-A simulation tool for the analysis of mitochondrial and plasma membrane potentials
AU - Huber, Heinrich J.
AU - Plchut, Martin
AU - Weisová, Petronela
AU - Düssmann, Heiko
AU - Wenus, Jakub
AU - Rehm, Markus
AU - Ward, Manus
AU - Prehn, Jochen H.M.
PY - 2009/1/30
Y1 - 2009/1/30
N2 -
Changes in the electrochemical gradients across biological membranes are excellent indicators of pathophysiological processes, drug action, or drug toxicity. Our previous studies have utilized the potentiometric probe tetramethylrhodamine methyl ester (TMRM) to characterize changes in mitochondrial function by monitoring alterations in the mitochondrial membrane potential (Δψ
m
) over time during glutamate excitotoxicity. However, fluorescently charged dyes such as TMRM respond to changes in both Δψ
m
and the plasma membrane (Δψ
p
) potentials making whole cell fluorescence data difficult to interpret. Here we have implemented a mathematical model that exploits the Nernstian behaviour of TMRM and uses automated Newton based root-finding fitting (TOXI-SIM) to model changes in TMRM fluorescence from multiple cells simultaneously, providing output on changes in Δψ
m
and Δψ
p
over time. Based on Ca
2+
responses, TOXI-SIM allows for an accurate modelling of TMRM traces for different injury paradigms (necrosis, apoptosis, tolerance). TOXI-SIM is provided as a user friendly public web service for trace analysis, with an additional online data base provided for the storage and retrieval of experimental traces (http://systemsbiology.rcsi.ie/tmrm/index.html).
AB -
Changes in the electrochemical gradients across biological membranes are excellent indicators of pathophysiological processes, drug action, or drug toxicity. Our previous studies have utilized the potentiometric probe tetramethylrhodamine methyl ester (TMRM) to characterize changes in mitochondrial function by monitoring alterations in the mitochondrial membrane potential (Δψ
m
) over time during glutamate excitotoxicity. However, fluorescently charged dyes such as TMRM respond to changes in both Δψ
m
and the plasma membrane (Δψ
p
) potentials making whole cell fluorescence data difficult to interpret. Here we have implemented a mathematical model that exploits the Nernstian behaviour of TMRM and uses automated Newton based root-finding fitting (TOXI-SIM) to model changes in TMRM fluorescence from multiple cells simultaneously, providing output on changes in Δψ
m
and Δψ
p
over time. Based on Ca
2+
responses, TOXI-SIM allows for an accurate modelling of TMRM traces for different injury paradigms (necrosis, apoptosis, tolerance). TOXI-SIM is provided as a user friendly public web service for trace analysis, with an additional online data base provided for the storage and retrieval of experimental traces (http://systemsbiology.rcsi.ie/tmrm/index.html).
KW - Bioenergetics
KW - Excitotoxicity
KW - Glutamate
KW - Mathematical modelling
KW - Mitochondrial membrane potential
KW - Plasma membrane potential
UR - http://www.scopus.com/inward/record.url?scp=57649214083&partnerID=8YFLogxK
U2 - 10.1016/j.jneumeth.2008.09.003
DO - 10.1016/j.jneumeth.2008.09.003
M3 - Article
C2 - 18824028
AN - SCOPUS:57649214083
SN - 0165-0270
VL - 176
SP - 270
EP - 275
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
IS - 2
ER -