BACKGROUND: Cardiolipin is a mitochondrial-specific phospholipid that maintains integrity of the electron transport chain (ETC) and plays a central role in myocardial ischemia/reperfusion injury. Tafazzin is an enzyme that is required for cardiolipin maturation. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) use to provide hemodynamic support for acute myocardial infarction has grown exponentially, is associated with poor outcomes, and is under active clinical investigation, yet the mechanistic effect of VA-ECMO on myocardial damage in acute myocardial infarction remains poorly understood. We hypothesized that VA-ECMO acutely depletes myocardial cardiolipin and exacerbates myocardial injury in acute myocardial infarction. METHODS: We examined cardiolipin and tafazzin levels in human subjects with heart failure and healthy swine exposed to VA-ECMO and used a swine model of closed-chest myocardial ischemia/reperfusion injury to evaluate the effect of VA-ECMO on cardiolipin expression, myocardial injury, and mitochondrial function. RESULTS: Cardiolipin and tafazzin levels are significantly reduced in the left ventricles of individuals requiring VA-ECMO compared with individuals without VA-ECMO before heart transplantation. Six hours of exposure to VA-ECMO also decreased left ventricular levels of cardiolipin and tafazzin in healthy swine compared with sham controls. To explore whether cardiolipin depletion by VA-ECMO increases infarct size, we performed left anterior descending artery occlusion for a total of 120 minutes followed by 180 minutes of reperfusion in adult swine in the presence and absence of MTP-131, an amphipathic molecule that interacts with cardiolipin to stabilize the inner mitochondrial membrane. Compared with reperfusion alone, VA-ECMO activation beginning after 90 minutes of left anterior descending artery occlusion increased infarct size (36±8% versus 48±7%; P <0.001). VA-ECMO also decreased cardiolipin and tafazzin levels, disrupted mitochondrial integrity, reduced electron transport chain function, and promoted oxidative stress. Compared with reperfusion alone or VA-ECMO before reperfusion, delivery of MTP-131 before VA-ECMO activation reduced infarct size (22±8%; P =0.03 versus reperfusion alone and P <0.001 versus VA-ECMO alone). MTP-131 restored cardiolipin and tafazzin levels, stabilized mitochondrial function, and reduced oxidative stress in the left ventricle. CONCLUSIONS: We identified a novel mechanism by which VA-ECMO promotes myocardial injury and further identify cardiolipin as an important target of therapy to reduce infarct size and to preserve mitochondrial function in the setting of VA-ECMO for acute myocardial infarction.

The validity of self-reported tobacco use is often questioned given the potential for underestimation of use. This study used data from a double-blind, placebo-controlled clinical trial of varenicline for smokeless tobacco dependence in India to evaluate the accuracy of self-reported smokeless tobacco cessation using biochemical validation procedures and to evaluate correlates of reporting inaccuracy. Smokeless tobacco users attending a dental clinic at AIIMS were randomized to placebo or varenicline; all participants received counseling. Detailed smokeless tobacco use was recorded and abstinence was defined as cotinine-verified 7-day point prevalence cessation (cotinine < 50 ng/ml) and breath CO > 10 ppm at the end of 12 weeks of treatment. One-half of study completers (82/165) self-reported abstinence. Biochemical verification confirmed that (65.9%) subjects provided accurate self-reports while (34.1%) participants underreported tobacco use. These data indicate poor agreement between self-reported and biochemically confirmed abstinence (κ = −0.191). Underreporters of tobacco use had significantly higher baseline cotinine (p < 0.05), total craving (p < 0.012), and negative reinforcement craving (p < 0.001) vs. those whose self-reports were correctly verified. These findings provide evidence to support the need for biochemical validation of self-reported abstinence outcomes among smokeless tobacco users in cessation programs in India and identify high levels of pretreatment cotinine and craving levels as potential correlates of false reporting.

Barth Syndrome (BTHS) is an early onset, lethal X-linked disorder caused by a mutation in tafazzin (TAFAZZIN), a mitochondrial acyltransferase that remodels monolysocardiolipin (MLCL) to mature cardiolipin (CL) and is essential for normal mitochondrial, cardiac, and skeletal muscle function. Current gene therapies in preclinical development require high levels of transduction. We tested whether TAFAZZIN gene therapy could be enhanced with the addition of a cell-penetrating peptide, penetratin (Antp). We found that TAFAZZIN-Antp was more effective than TAFAZZIN at preventing the development of pathological cardiac hypertrophy and heart failure. These findings indicate that a cell-penetrating peptide enhances gene therapy for BTHS.

This study evaluates the effects of hydro-alcoholic root extract of Delphinium denudatum Wall (Jadwar, family; Ranunculaceae) for its ability to attenuate the nicotine-withdrawal in nicotine-dependent rats. The physical dependence on nicotine was induced in male adult Wistar albino rats (175-250 g) by subcutaneous implantation of Alzet mini osmotic pumps which ...

Background: Barth syndrome (BTHS) is a rare X-linked mitochondrial disorder caused by mutations in the TAFAZZIN gene, which disrupts cardiolipin (CL) remodeling and mitochondrial function. While cardiac manifestations of BTHS are well characterized, the mechanisms underlying skeletal muscle weakness and fatigability are poorly understood. Methods: We investigated neuromuscular and mitochondrial alterations in a novel murine model (Taz ^PM ) carrying a patient-derived D75H point mutation in Tafazzin . This mutation preserves protein abundance but abolishes enzymatic activity. Skeletal muscle function was assessed via weightlifting and hanging tests. Muscle fiber composition and neuromuscular junction (NMJ) integrity were evaluated using immunofluorescence, western blotting, and in vivo electrophysiology. Mitochondrial morphology was examined by transmission electron microscopy, and bioenergetics were quantified using ultra-performance liquid chromatography. Stress signaling was assessed by western blotting. Results: Male Taz ^PM mice exhibited elevated monolysocardiolipin and reduced mature CL levels, confirming deficient transacylase activity. These mice exhibited lower muscle strength and endurance, smaller muscle fibers of all types, and a shift toward fast-twitch type 2B fibers, which are more susceptible to fatigue. Electrophysiological analysis revealed a 60% reduction in motor unit number and an increase in average single motor unit potential, indicating motor neuron remodeling. NMJ protein analysis showed decreased MUSK and DOK7 and increased CHRNA1, suggesting impaired NMJ integrity. Despite mitochondrial structural abnormalities and reduced expression of key mitochondrial proteins (NDUFB8, MCU, TMEM65), resting ATP, phosphocreatine, and adenine nucleotide ratios were unchanged in both glycolytic and oxidative muscles. However, stress signaling pathways were markedly activated, including phosphorylation of eIF2α, increased CHOP, DELE1, p53 expression, and altered Wnt/β-catenin signaling components. Conclusions: Deficiency of Tafazzin enzymatic activity in skeletal muscle is sufficient to result in widespread neuromuscular remodeling, including fiber size/type shifts, motor unit loss, NMJ dysregulation, and stress pathway activation, without overt energetic failure at rest. These findings suggest that myopathy in BTHS arises not solely from mitochondrial ATP insufficiency but rather from cumulative structural and signaling disruptions.

Mustard keratopathy, caused by exposure of the cornea to sulfur or nitrogen mustard vesicants, chemical warfare agents, can lead to severe and often irreversible vision loss. Despite considerable efforts to develop medical countermeasures, including anti-inflammatory, antioxidant, anti-fibrotic, and anti-angiogenic therapies, no treatment effectively targets the underlying mechanisms responsible for mustard-induced tissue injury or prevents long-term disease progression. In the present study, we comprehensively define mitochondrial mechanisms underlying nitrogen mustard-induced corneal injury in both our cell culture model in vitro and a mouse model in vivo. DNM1L (aka Drp1) is a mitochondria-localized dynamin-related GTPase that executes mitochondrial fission and facilitates the autophagic elimination of damaged mitochondrial components. Using complementary in vitro and in vivo models, we demonstrate that nitrogen mustard rapidly induces excessive mitochondrial fragmentation, bioenergetic collapse, membrane depolarization, oxidative stress, intracellular acidification, mitophagy, and apoptotic cell death. Pharmacological inhibition of DNM1L with Mdivi-1 preserves mitochondrial structure and function, restores cellular metabolism, reduces oxidative damage, and markedly improves corneal epithelial integrity, and tissue repair following nitrogen mustard exposure. Collectively, these findings establish mitochondrial dysfunction as a central pathological mechanism in mustard keratopathy and identify DNM1L-mediated mitochondrial remodeling as a therapeutically actionable target. The findings provide strong preclinical evidence supporting mitochondrial-directed therapy as a promising strategy for treating mustard keratopathy. This work was funded by: Project grant R01EY035220 (to MEF) from the National Eye Institute, National Institutes of Health, Bethesda, MD, USA A grant from the Massachusetts Lions Eye Research Foundation, Millis, MA, USA to the Department of Ophthalmology, Tufts University School of Medicine A challenge grant from Research to Prevent Blindness, Inc., New York, NY, USA to the Department of Ophthalmology, Tufts University School of Medicine One Sentence Summary: The study findings establish mitochondrial dysfunction as a central pathological mechanism in mustard keratopathy and identify DNM1L-mediated mitochondrial remodeling as a therapeutically actionable target.