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Role of TRPC Channels in Mediating Calcium Signaling Response of Brain Microvessel Endothelial Cells to Mechanically‐Induced Injury
Author(s) -
Berrout Jonathan,
Jin Min,
O'Neil Roger G.
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.1020.4
Subject(s) - trpc , transient receptor potential channel , microvessel , trpv , chemistry , endothelial stem cell , calcium , microbiology and biotechnology , calcium channel blocker , channel blocker , biophysics , voltage dependent calcium channel , ruthenium red , fura 2 , calcium in biology , cytosol , medicine , biology , biochemistry , angiogenesis , in vitro , enzyme , receptor , organic chemistry , trpv1
Traumatic brain injury (TBI) can lead to the breakdown of the blood brain barrier (BBB). Since elevation of cytosolic calcium levels, [Ca]i, can compromise the BBB integrity, we assessed the effects of mechanical injury on [Ca]i in brain endothelial cells. Mouse brain microvessel endothelial cells (bEnd3 cells) were grown on elasticized membranes (BioFlex plates) and [Ca]i monitored using fura 2 fluorescence imaging. Application of a "moderate" injury, using a pressure/stretch pulse of 50 ms (~35% stretch; Cell Injury Controller II module), induced a rapid transient increase in [Ca]i by 110 +/‐ 17 nM (n = 6) which slowly returned to elevated basal levels over several minutes. In the absence of extracellular Ca the injury‐induced [Ca]i transient was greatly reduced, but not eliminated, implicating both Ca release from stores and Ca influx across the cell membrane. Unloading of Ca stores by treatment with thapsagargin (10 uM) did not abolish the injury transient. Addition of LOE‐908 (1 uM), a TRPC channel blocker, partially blocked the transient [Ca]i increase, while ruthenium red, a TRPV channel blocker, was without affect. It is concluded that mechanical injury of brain endothelial cells induces calcium influx, implicating [Ca]i transients in injury‐induced barrier breakdown. Further, the induced Ca influx appears to be associated with injury‐induced TRPC channel activation, but not TRPV channel activation.