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Updated: May 27, 2026
In vitro Assessment of Myocardial Protection following Hypothermia-Preconditioning in a Human Cardiac Myocytes Model
Published on: October 27, 2020
Therapeutic hypothermia cardioprotection in murine hemorrhagic shock/resuscitation differentially affects p38α/p38γ,
Jing Li1, David G Beiser, Huashan Wang
1Department of Emergency Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
Background:
Therapeutic hypothermia (TH) has demonstrated great potential for forestalling cardiovascular collapse and improving outcomes in the setting of severe hemorrhagic shock (HS). We used an established mouse model of severe HS to study the response of interrelated cardiac-signaling proteins p38, HspB1, and Akt to shock, resuscitation, and cardioprotective TH.
Methods:
Adult female C57BL6/J mice were bled and maintained at a mean arterial pressure of 35 mm Hg. After 30 minutes, mice were randomized to 120 minutes of TH (33°C ± 0.5°C) or continued normothermia at 37°C. After 90 minutes, animals were resuscitated and monitored for 180 minutes. Cardiac p38, Akt, and HspB1 phosphorylation (p-p38, p-Akt, and p-HspB1), expression, and Akt/HspB1 interactions were measured at serial time points during HS and resuscitation. Markers of mitochondrial damage (plasma cytochrome c), inflammation (myeloperoxidase), and apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling) were analyzed.
Results:
By 15 minutes HS, p-p38 and p-HspB1 significantly increased while p-Akt(T308) decreased (p < 0.05). TH attenuated phosphorylation of the p38α isoform during HS and increased phosphorylation of the p38γ isoform during both HS and early resuscitation (p < 0.05). TH increased Akt/HspB1 coimmunoprecipitation during early resuscitation and increased p-Akt and HspB1 expression during late resuscitation (p < 0.05). Finally, TH attenuated the myocardial myeloperoxidase and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining and plasma cytochrome c during late resuscitation.
Conclusions:
TH increases phosphorylation of p38γ during both HS and early resuscitation, but attenuates phosphorylation of p38α, increases Akt/HspB1 interaction, and modulates Akt phosphorylation during HS and resuscitation. Such TH-related signaling events are associated with reduced cardiac inflammation, apoptosis, and mitochondrial injury.
