TY - JOUR
T1 - Pyruvate minimizes rtPA toxicity from in vitro oxygen-glucose deprivation and reoxygenation
AU - Ryou, Myoung Gwi
AU - Choudhury, Gourav Roy
AU - Winters, Ali
AU - Xie, Luokun
AU - Mallet, Robert T.
AU - Yang, Shao Hua
N1 - Funding Information:
This work was supported by National Institutes of Health grants R01NS054687 (SY) , R01NS054651 (SY) , R01NS076975 (RM) , T32 AG020494 (MR) , and RI6055 (MR) .
PY - 2013/9/12
Y1 - 2013/9/12
N2 - Clinical application of recombinant tissue plasminogen activator (rtPA) for stroke is limited by hemorrhagic transformation, which narrows rtPA's therapeutic window. In addition, mounting evidence indicates that rtPA is potentially neurotoxic if it traverses a compromised blood brain barrier. Here, we demonstrated that pyruvate protects cultured HT22 neuronal and primary microvascular endothelial cells co-cultured with primary astrocytes from oxygen glucose deprivation (OGD)/reoxygenation stress and rtPA cytotoxicity. After 3 or 6 h OGD, cells were reoxygenated with 11 mmol/L glucose±pyruvate (8 mmol/L) and/or rtPA (10 μg/ml). Measured variables included cellular viability (calcein AM and annexin-V/propidium iodide), reactive oxygen species (ROS; mitosox red and 2′,7′-dichlorofluorescein diacetate), NADPH, NADP+ and ATP contents (spectrophotometry), matrix metalloproteinase-2 (MMP2) activities (gelatin zymography), and cellular contents of MMP2, tissue inhibitor of metalloproteinase-2 (TIMP2), and phosphor-activation of anti-apoptotic p70s6 kinase, Akt and Erk (immunoblot). Pyruvate prevented the loss of HT22 cells after 3 h OGD±rtPA. After 6 h OGD, rtPA sharply lowered cell viability; pyruvate dampened this effect. Three hours OGD and 4 h reoxygenation with rtPA increased ROS formation by about 50%. Pyruvate prevented this ROS formation and doubled cellular NADPH/NADP + ratio and ATP content. In endothelial cell monolayers, 3 h OGD and 24 h reoxygenation increased FITC-dextran leakage, indicating disruption of intercellular junctions. Although rtPA exacerbated this effect, pyruvate prevented it while sharply lowering MMP2/TIMP2 ratio and increasing phosphorylation of p70s6 kinase, Akt and Erk. Pyruvate protects neuronal cells and microvascular endothelium from hypoxia-reoxygenation and cytotoxic action of rtPA while reducing ROS and activating anti-apoptotic signaling. These results support the proposed use of pyruvate as an adjuvant to dampen the side effects of rtPA treatment, thereby extending rtPA's therapeutic window.
AB - Clinical application of recombinant tissue plasminogen activator (rtPA) for stroke is limited by hemorrhagic transformation, which narrows rtPA's therapeutic window. In addition, mounting evidence indicates that rtPA is potentially neurotoxic if it traverses a compromised blood brain barrier. Here, we demonstrated that pyruvate protects cultured HT22 neuronal and primary microvascular endothelial cells co-cultured with primary astrocytes from oxygen glucose deprivation (OGD)/reoxygenation stress and rtPA cytotoxicity. After 3 or 6 h OGD, cells were reoxygenated with 11 mmol/L glucose±pyruvate (8 mmol/L) and/or rtPA (10 μg/ml). Measured variables included cellular viability (calcein AM and annexin-V/propidium iodide), reactive oxygen species (ROS; mitosox red and 2′,7′-dichlorofluorescein diacetate), NADPH, NADP+ and ATP contents (spectrophotometry), matrix metalloproteinase-2 (MMP2) activities (gelatin zymography), and cellular contents of MMP2, tissue inhibitor of metalloproteinase-2 (TIMP2), and phosphor-activation of anti-apoptotic p70s6 kinase, Akt and Erk (immunoblot). Pyruvate prevented the loss of HT22 cells after 3 h OGD±rtPA. After 6 h OGD, rtPA sharply lowered cell viability; pyruvate dampened this effect. Three hours OGD and 4 h reoxygenation with rtPA increased ROS formation by about 50%. Pyruvate prevented this ROS formation and doubled cellular NADPH/NADP + ratio and ATP content. In endothelial cell monolayers, 3 h OGD and 24 h reoxygenation increased FITC-dextran leakage, indicating disruption of intercellular junctions. Although rtPA exacerbated this effect, pyruvate prevented it while sharply lowering MMP2/TIMP2 ratio and increasing phosphorylation of p70s6 kinase, Akt and Erk. Pyruvate protects neuronal cells and microvascular endothelium from hypoxia-reoxygenation and cytotoxic action of rtPA while reducing ROS and activating anti-apoptotic signaling. These results support the proposed use of pyruvate as an adjuvant to dampen the side effects of rtPA treatment, thereby extending rtPA's therapeutic window.
KW - Antioxidant
KW - Blood brain barrier
KW - Cell death
KW - Matrix metalloproteinases
KW - Monocarboxylate transporter
KW - Reactive oxygen species
UR - http://www.scopus.com/inward/record.url?scp=84883219366&partnerID=8YFLogxK
U2 - 10.1016/j.brainres.2013.07.029
DO - 10.1016/j.brainres.2013.07.029
M3 - Article
C2 - 23891792
AN - SCOPUS:84883219366
SN - 0006-8993
VL - 1530
SP - 66
EP - 75
JO - Brain Research
JF - Brain Research
ER -