TY - JOUR
T1 - Temporal Changes in Caspase-1 and Caspase-8 Activities Following Brain Hypoxia With and Without Src kinase Inhibition in a Piglet Animal Model
AU - Angelis, Dimitrios
AU - Fontánez Nieves, Tania D.
AU - Delivoria-Papadopoulos, Maria
PY - 2015/11/1
Y1 - 2015/11/1
N2 - The Src family kinases are a family of intracellular, non-receptor tyrosine kinases that are involved in a variety of cellular functions including the regulation of inflammation and apoptosis after brain hypoxia. Caspase-1 (C1) activates IL-1β through the formation of complex structures, the inflammasomes, while caspase-8 (C8) is part of the extrinsic apoptotic pathway. C8 has been found to directly activate the production of IL-1β. Previously, we observed that C1 and IL-1β are increased in the acute phase after hypoxia in the brain of piglets, but they follow a different pattern long term, with C1 remaining activated throughout the period of observation, while IL-1β returning to baseline at 15 days. Src kinase inhibition ameliorated the activation of C1 and IL-1β early, but did not appear to have any effect long term. Prompted by these findings, we assessed the changes that occur over time (1 h and 15 days) in C1 and C8 activities after brain hypoxia as well as the effect of pretreatment with a Src kinase inhibitor, PP2 on these biochemical markers. Enzymatic activities were determined by spectrophotometry with measurements of C1 and C8 in each cytosolic brain sample (N = 4 in each group). We found that C1 and C8 activities increase in the acute phase following hypoxia in the brain of newborn piglets, with C8 relatively more than C1 (C8/C1 ratio increased from 2:1 as baseline to 3:1 in hypoxia). Fifteen days after hypoxia C8/C1 ratio decreased to about 1:1. In piglets that were pretreated with a Src kinase selective inhibitor (PP2) and then subjected to hypoxia, the C8/C1 ratio early increase was not observed. Immediately after hypoxia C8 and C1 follow a similar pattern of increase while long term this appears to dissociate. We propose that following this experimental methodology, the previously observed IL-1β production after hypoxia might be associated with C8 rather than C1 and that Src kinase is involved in the above process.
AB - The Src family kinases are a family of intracellular, non-receptor tyrosine kinases that are involved in a variety of cellular functions including the regulation of inflammation and apoptosis after brain hypoxia. Caspase-1 (C1) activates IL-1β through the formation of complex structures, the inflammasomes, while caspase-8 (C8) is part of the extrinsic apoptotic pathway. C8 has been found to directly activate the production of IL-1β. Previously, we observed that C1 and IL-1β are increased in the acute phase after hypoxia in the brain of piglets, but they follow a different pattern long term, with C1 remaining activated throughout the period of observation, while IL-1β returning to baseline at 15 days. Src kinase inhibition ameliorated the activation of C1 and IL-1β early, but did not appear to have any effect long term. Prompted by these findings, we assessed the changes that occur over time (1 h and 15 days) in C1 and C8 activities after brain hypoxia as well as the effect of pretreatment with a Src kinase inhibitor, PP2 on these biochemical markers. Enzymatic activities were determined by spectrophotometry with measurements of C1 and C8 in each cytosolic brain sample (N = 4 in each group). We found that C1 and C8 activities increase in the acute phase following hypoxia in the brain of newborn piglets, with C8 relatively more than C1 (C8/C1 ratio increased from 2:1 as baseline to 3:1 in hypoxia). Fifteen days after hypoxia C8/C1 ratio decreased to about 1:1. In piglets that were pretreated with a Src kinase selective inhibitor (PP2) and then subjected to hypoxia, the C8/C1 ratio early increase was not observed. Immediately after hypoxia C8 and C1 follow a similar pattern of increase while long term this appears to dissociate. We propose that following this experimental methodology, the previously observed IL-1β production after hypoxia might be associated with C8 rather than C1 and that Src kinase is involved in the above process.
KW - Apoptosis
KW - Caspase-1
KW - Caspase-8
KW - Hypoxic ischemic brain injury
KW - Neuro-inflammation
KW - Newborn piglet
KW - PP2
KW - Src kinase
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U2 - 10.1007/s11064-015-1717-8
DO - 10.1007/s11064-015-1717-8
M3 - Article
C2 - 26342830
AN - SCOPUS:84947043303
SN - 0364-3190
VL - 40
SP - 2270
EP - 2279
JO - Neurochemical Research
JF - Neurochemical Research
IS - 11
ER -