A Rare Glimpse behind the Mask of Sepsis-induced Organ Failures Provides Hope for an Eventual Cure

Cardiac dysfunction in critical illness

PURPOSE OF REVIEW

Sepsis and septic shock are prevalent conditions that are likely to increase in prevalence in the future. Given the high mortality and morbidity associated with sepsis and sepsis-induced cardiac dysfunction, we must continue to make advances in knowledge of the complex physiologic interactions and how we may target specific mediators for potential therapeutic options in the future.

RECENT FINDINGS

Multiple biomarkers have been discovered, which when assayed in sepsis-induced cardiomyopathy predict morbidity and mortality. With increased sensitivity of echocardiography, we can diagnose subclinical cardiac dysfunction, which may have future implications for slowing or preventing progressive dysfunction.

SUMMARY

Sepsis-induced cardiomyopathy is the result of complicated interactions between the pathogen, the body's response to infection, and iatrogenic injury. Interplay between inflammatory, metabolic, and adrenergic systems results in direct and indirect myocardial injury leading to decreases in both systolic and diastolic cardiac function. As the interactions are further elucidated with additional research into other proteins and mediators, new treatment options can be researched. VIDEO ABSTRACT.

The emerging neuroprotective role of mitochondrial uncoupling protein-2 in traumatic brain injury

Traumatic brain injury (TBI) is a multifaceted disease with intrinsically complex heterogeneity and remains a significant clinical challenge to manage. TBI model systems have demonstrated many mechanisms that contribute to brain parenchymal cell death, including glutamate and calcium toxicity, oxidative stress, inflammation, and mitochondrial dysfunction. Mitochondria are critically regulated by uncoupling proteins (UCP), which allow protons to leak back into the matrix and thus reduce the mitochondrial membrane potential by dissipating the proton motive force. This uncoupling of oxidative phosphorylation from adenosine triphosphate (ATP) synthesis is potentially critical for protection against cellular injury as a result of TBI and stroke. A greater understanding of the underlying mechanism or mechanisms by which uncoupling protein-2 (UCP2) functions to maintain or optimize mitochondrial function, and the conditions which precipitate the failure of these mechanisms, would inform future research and treatment strategies. We posit that UCP2-mediated function underlies the physiological response to neuronal stress associated with traumatic and ischemic injury and that clinical development of UCP2-targeted treatment would significantly impact these patient populations. With a focus on clinical relevance in TBI, we synthesize current knowledge concerning UCP2 and its potential neuroprotective role and apply this body of knowledge to current and potential treatment modalities.