Significance: The assembly and function of membrane proteins depend on the lipid milieu. In recent years the protein components of the mitochondrial calcium uniporter have been identified, but its specific phospholipid requirements are not known. Utilizing yeast mutants defective in their ability to synthesize different phospholipids, we identify a specific requirement of cardiolipin (CL) in the stability and function of the mitochondrial uniporter. Our findings are translatable to higher organisms because endogenous uniporter abundance is decreased in patient-derived cells and cardiac tissue from Barth syndrome, an inherited deficiency in CL levels. This work shows that yeast phospholipid mutants can be leveraged to uncover specific lipid requirements of membrane proteins and suggests impaired mitochondrial calcium signaling in the pathogenesis of Barth syndrome.

Nutrient stress triggers transcriptional changes that limit Ca ²⁺ influx into mitochondria through the MCU.

Background/Objectives: Fecal peritonitis following penetrating abdominal trauma is a serious condition that often results in sepsis and organ failure. The aim of our study was to develop a novel conscious porcine model of sepsis and organ dysfunction caused by multiple penetrating injuries to the small and large intestines. Methods: Twelve female Yorkshire pigs (average weight 50.6 ± 6.5 kg) were divided into two groups: Penetrating Abdominal Trauma (PAT) (n = 8) and Control (n = 4). All surgical procedures were performed under anesthesia with adequate analgesia. In the PAT group, the small and large intestines were punctured, and feces mixed with saline were introduced into the abdominal cavity to induce peritonitis. The Control group received sham surgery with only saline solution. The animals were observed in a conscious state over a period of 72 h, vital parameters were recorded, and blood samples were taken regularly. We adapted a pig-specific SOFA score and developed pig-specific SIRS criteria and NEWS2 score to assess organ function. The model was validated by independent investigators. Results: The survival rate in the PAT group was 75%, with an average survival time of 58.5 h, while all animals in the Control group survived to euthanasia. Monitoring showed pathophysiological changes, such as tachycardia, leucopenia, and thrombocytopenia, indicative of sepsis and organ dysfunction. Blinded investigators independently confirmed the model’s validity. Conclusions: A new swine model of penetrating abdominal trauma and sepsis has been successfully developed that demonstrates significant physiological and immunologic changes comparable to human sepsis. This new model provides a realistic platform for future research into sepsis, its diagnostics, and the evaluation of therapeutic strategies.

Background/Objectives: Extremity trauma represents a significant proportion of battlefield injuries and is prevalent in polytraumatized patients from accidents. Delayed antibiotic treatment and surgical intervention can lead to wound infections, contributing to preventable mortality. This preliminary study aimed to develop a conscious swine model of complex extremity trauma that induces systemic inflammatory response syndrome (SIRS). Methods: All surgical procedures were conducted under anesthesia with sufficient analgesia. All swine were instrumented with a telemetry device and catheters at least 3 days prior to any injury. In phase 1 of model development, a complex extremity injury was performed that consisted of skin and muscle loss, bone defect, severe hemorrhage, and 2 h tourniquet application. In phase 2, multi-drug resistant Gram-positive and Gram-negative bacteria were inoculated topically at the injury site to exacerbate pathophysiological changes towards SIRS. Post-injury, conscious animals were assessed a minimum of twice daily, including pain assessment, neurological response, and vital signs. Blood samples were collected for microbiological testing, complete blood cell counts, and biochemical analysis. Results: After establishing SIRS criteria for Sinclair swine, we developed a model of severe extremity trauma leading to SIRS. During phase 1, resuscitative fluids were reduced and discontinued, with animals surviving 24 h and maintaining SIRS for up to 4 h post-recovery. Phase 2 showed that Gram-negative and Gram-positive pathogens can exacerbate and prolong SIRS. After 72 h, localized infection at the injury site was observed in all animals. Conclusions: We established a new swine model of complex extremity trauma with SIRS. Our model is consistent, reproducible, and relevant to prolonged care scenarios, providing a platform for future research into the evaluation of preventative and therapeutic strategies.