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Holody, C. D.

Publications and source records attributed to Holody, C. D..

2 recordsLinked to original sources

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↗

Maternal iron deficiency remodels cardiac mitochondria and alters stress responses in hypertensive pregnancy

Maternal iron deficiency (ID) during pregnancy is associated with cardiovascular adaptations, including reduced blood pressure and improved cardiac efficiency in hypertensive pregnancy. However, whether these apparent functional gains are accompanied by preserved cardiac mitochondrial function remains unclear. Given the high metabolic demands of the maternal heart and irons central role in oxidative metabolism, we examined how maternal ID affects cardiac mitochondrial ultrastructure, respiration, dynamics, and redox status in pregnant spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. Female SHR and WKY rats were fed iron-replete or iron-restricted diets before and throughout gestation. On gestational day 21, cardiac mitochondrial ultrastructure was assessed by transmission electron microscopy, respiration by high-resolution respirometry, mitochondrial dynamics and quality control proteins by immunoblotting, and antioxidant gene expression by RT-qPCR. Iron restriction reduced maternal hemoglobin levels in both strains. ID dams exhibited enlarged, morphologically heterogeneous mitochondria with reduced cristae density and lower succinate-supported respiration. SHR dams exhibited reduced fusion signalling, reflected by a lower L-OPA1:S-OPA1 ratio, lower MFN2 abundance, and further ID-associated reductions in MFN1 and MFN2. In contrast, DRP1 phosphorylation increased in ID-WKY dams. Iron restriction increased LC3-II:I ratio and BNIP3 in SHR, increased PINK1 in both strains, and increased antioxidant gene expression in ID-SHR but decreased in ID-WKY dams. Despite these alterations, downstream apoptosis activation was not observed. Maternal ID was associated with remodelling of myocardial mitochondrial ultrastructure and selectively constrains iron-dependent respiration in hypertensive pregnancy, suggesting favourable hemodynamic adaptations may coexist with underlying bioenergetic constraints in the maternal heart.

physiology↗