Biology subjects

Macala, K. F.

Publications and source records attributed to Macala, K. F..

3 recordsLinked to original sources

bioRxiv2026

Mitochondrial-targeted therapy with elamipretide preserves cardiac function and prevents late mortality in murine sepsis-induced cardiac dysfunction.

Sepsis-induced cardiac dysfunction (SICD) occurs in nearly half of septic patients, is associated with increased mortality, and lacks targeted therapy. Emerging evidence implicates impaired mitochondrial function and metabolic inflexibility as central contributors to myocardial depression. Here, we characterized SICD in a murine model of polymicrobial sepsis and evaluated the therapeutic potential of the cardiolipin-stabilizing peptide elamipretide (Ela). Sepsis induced marked impairments in cardiac performance, accompanied by reductions in cardiac cardiolipin content, impaired mitochondrial respiratory capacity localized to complex I, and altered substrate utilization. Integration of stable isotope metabolic flux tracing with lipidomic, metabolomic, and proteomic analyses identified a convergent metabolic bottleneck at the level of the electron transport system. This defect was associated with upstream accumulation of acetyl-CoA, Co-A esters, and ketone bodies, consistent with impaired oxidative flux and energetic failure. Administration of a single early dose of Ela restored cardiolipin content, complex I function, normalized metabolic flux, improved cardiac function during both acute sepsis and recovery, and completely prevented late sepsis-related mortality. These findings identify cardiolipin-dependent mitochondrial dysfunction as a central pathogenic mechanism underlying SICD and position mitochondrial-targeted therapy as a promising therapeutic strategy in sepsis. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/736409v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@1ca5b47org.highwire.dtl.DTLVardef@2ecfc2org.highwire.dtl.DTLVardef@149ccb9org.highwire.dtl.DTLVardef@1fbcb6_HPS_FORMAT_FIGEXP M_FIG C_FIG Ela improves SICD by stabilizing cardiolipin species and improving mitochondrial complex I function. SICD depicted in red denotes conditions altered compared to healthy control cardiomyocyte, SICD+Ela depicted in green denotes changes relative to SICD. SICD, sepsis-induced cardiac dysfunction; ELA, elamipretide; ADP, adenosine diphosphate; ATP, adenosine triphosphate; ROS, reactive oxygen species.

physiology↗

bioRxiv2026

A neonatal rat sepsis score captures the time course and severity of disease in a clinically relevant rat peritonitis model.

BackgroundNeonatal sepsis is a major cause of infant morbidity and mortality worldwide, particularly in preterm and very low birthweight babies. Fundamental differences between neonates and adults warrant clinically relevant models of neonatal sepsis. Here, we describe a preclinical fecal-slurry (FS)-induced peritonitis model of polymicrobial sepsis in neonatal rats, along with a novel neonatal rat sepsis score (nRSS) to monitor illness severity. MethodsPeritonitis was induced in 3-day-old Sprague Dawley rats by intraperitoneal injection of various doses (0.3-1.5mg/g body weight) of fecal slurry (FS); control pups received equivalent doses of vehicle. All pups received analgesics (buprenorphine), antibiotics (ampicillin and gentamicin), and fluids (saline) to model clinical standards of sepsis treatment. Time-dependent changes in circulating cytokines (IL-6, IL-1{beta}) and biomarkers of sepsis pathology (hemoglobin, glucose, alanine transaminase [ALT] levels) were assessed and correlated with nRSS scores. ResultsFS administration caused a dose-dependent increase in severity of sepsis over time, as indicated by increases in mortality rates (based on predefined criteria for euthanasia), nRSS scores, as well as time-dependent changes in circulating glucose, hemoglobin, IL-6, IL-1{beta}, and ALT activity levels. nRSS scores correlated with all quantitative measures of sepsis pathology. Notably, females showed higher mortality and higher early NRSS scores than males at moderate to high FS doses, yet biochemical markers and time of death did not differ between sexes, suggesting that the apparent female vulnerability may reflect more conspicuous behavioral manifestations of illness rather than greater underlying physiological severity. ConclusionInduction of peritonitis in rats at postnatal day 3 produced a consistent and reproducible model of polymicrobial neonatal sepsis. Illness severity was monitored using a newly developed nRSS. By minimizing distress and incorporating standards of care, this model and scoring system may serve as a platform for future investigations into the underlying mechanisms and potential therapeutic interventions for neonatal sepsis. ImpactO_LIA clinically relevant rat model of neonatal polymicrobial sepsis was developed, incorporating standards of care (analgesics, antibiotics, and fluid resuscitation) to better reflect the clinical context in which preclinical findings must ultimately translate. C_LIO_LIA novel neonatal rat sepsis scoring system (nRSS) was developed and validated, providing a sensitive, non-invasive measure of disease severity that correlates with biochemical markers and predicts mortality. C_LIO_LIFemale pups showed higher mortality and earlier behavioral signs of illness than males despite equivalent biochemistry, highlighting that clinical scores may capture sex-dependent vulnerability not apparent in standard biochemical measures. C_LIO_LITogether, this model and scoring system offer a refined platform for mechanistic and therapeutic studies of neonatal sepsis while advancing the welfare-conscious 3Rs principles essential to rigorous preclinical research C_LI

physiology↗

bioRxiv2026

Early sex-specific organ transcriptional divergence without physiological differences in a murine model of fecal-induced peritonitis

Sepsis is defined as a dysregulated response to infection, leading to life-threatening organ dysfunction that particularly affects parenchymal organs. Clinical studies remain inconclusive regarding the impact of biological sex on sepsis, and preclinical studies are predominantly performed in male animals. We examined early (8 h) septic responses in male and female mice using a fecal-induced peritonitis (FIP) model. Blood biochemical parameters, body temperature, and murine sepsis scores provided evidence of a septic response in animals randomized to FIP compared to controls, but showed no physiological differences between male and female mice. Transcriptomic analysis of the liver, kidney, and lung showed consistent inflammatory activation in response to sepsis as compared to controls. Notably, in the kidney and lung, female mice exhibited stronger immune activation and a heightened inflammatory response compared to males. Thus, biological sex differences in the septic response can be detected in early acute sepsis without apparent physiological differences.

pathology↗