The severity of intrahepatic cholestasis of pregnancy and its association with pregnancy complications and neonatal asphyxia: A single-center case analysis and systematic review.

Intrahepatic cholestasis of pregnancy (ICP) poses significant risks to maternal and neonatal health. Our study at Jiangxi Provincial Maternal and Child Health Hospital analyzed clinical and biochemical markers in singleton pregnancies diagnosed with ICP from October 2016 to December 2022. This research, supported by a systematic review and meta-analysis of existing studies, highlights the increasing incidence of ICP and its association with elevated levels of total bile acids, transaminases, and bilirubin. Our findings indicate a marked increase in the risk of preterm birth, cesarean delivery, and neonatal asphyxia as the severity of ICP escalates. This underscores the need for vigilant monitoring and management of affected pregnancies. By confirming the relationship between biochemical marker abnormalities and adverse pregnancy outcomes, our study advocates for enhanced clinical strategies and paves the way for future research aimed at improving prevention, diagnosis, and treatment methods for ICP.

CTFusion: CNN-transformer-based self-supervised learning for infrared and visible image fusion.

Infrared and visible image fusion (IVIF) is devoted to extracting and integrating useful complementary information from muti-modal source images. Current fusion methods usually require a large number of paired images to train the models in supervised or unsupervised way. In this paper, we propose CTFusion, a convolutional neural network (CNN)-Transformer-based IVIF framework that uses self-supervised learning. The whole framework is based on an encoder-decoder network, where encoders are endowed with strong local and global dependency modeling ability via the CNN-Transformer-based feature extraction (CTFE) module design. Thanks to the development of self-supervised learning, the model training does not require ground truth fusion images with simple pretext task. We designed a mask reconstruction task according to the characteristics of IVIF, through which the network can learn the characteristics of both infrared and visible images and extract more generalized features. We evaluated our method and compared it to five competitive traditional and deep learning-based methods on three IVIF benchmark datasets. Extensive experimental results demonstrate that our CTFusion can achieve the best performance compared to the state-of-the-art methods in both subjective and objective evaluations.

Light-induced manipulation of ultra-low surface tension droplets on stable quasi-liquid surfaces.

HYPOTHESIS: Perfluorocarbon is commonly used as a coolant, chemical reaction carrier solvent, medical anti-hypoxic agents and blood substitutes. The realization of non-contact complex manipulation of perfluorocarbon liquids is urgently needed in human life and industrial production. However, most liquid-repellent interfaces are ineffective for the transport of ultra-low surface tension perfluorocarbon liquids, and struggle to maintain good durability due to unstable air or oil cushions in the surface. Therefore, preparing surfaces for stable non-contact complex manipulation of ultra-low surface tension droplets remains a challenge. EXPERIMENTS: In this paper, a novel solution, a photothermal responsive droplet manipulation surface based on polydimethylsiloxane brushes, has been reported. On this surface, droplets with different surface tensions (as low as 10 mN/m) can be efficiently manipulated through induced near-infrared light. Notably, this surface maintains its effectiveness after exposure to extreme anthropogenic conditions. FINDINGS: The interface effect between perfluorocarbon droplets and polydimethylsiloxane brushes by near-infrared light-induced was investigated in detail. In addition, ultra-low surface tension droplets demonstrate the ability to transport solid particles. The conductive droplets exhibit sophisticated manipulation realizing the controlled switching of smart circuits. This research opens up new possibilities for advancing the capabilities and adaptability of ultralow surface tension droplets in a range of applications.

Lessons to Learn About the Misdiagnosis of a Rare Case in China: Bart Syndrome or Carmi Syndrome?

Objective: We report a case of Carmi Syndrome in a neonate. Aim: To share our lessons in diagnosis of the case of Carmi Syndrome. Case Report: Carmi Syndrome is an extremely rare autosomal recessive genetic disorder characterized the coexistence of pyloric atresia and junctional epidermolysis bullosa, and with aplasia cutis congenita in approximately 28% patients. In this case, a full-term male neonate was born to a G4P2+1L1 multipara through cesarean section delivery in hospital in a non-consanguineous marriage with 4000mL of II°meconium-stained amniotic fluid. He was found extensive skin loss over lower legs and other parts, with scattered blisters and bilateral microtia. Plain abdominal X-ray revealed a large gastric air bubble with no gas distally. The mother had an intrauterine fetal loss previously for reasons unknown. The dermatologist diagnosed the newborn with Bart Syndrome, while the pediatric surgeon diagnosed congenital pyloric atresia(CPA). The parents refused further treatment and the neonate passed away about 30 hours after birth. Outcome: The neonate passed away about 30 hours after birth. Conclusion: Lessons from this case:①.Rule out Carmi Syndrome in patients with PA, and differentiate Bart syndrome and Carmi Syndrome in patients with abnormal skin manifestations. ②. For rare and/or severe diseases, multidisciplinary teams(MDTs) should be establish. ③. Genetic counseling and prenatal diagnosis are necessary prior to subsequent childbearings. ④.Termination of pregnancy might be contemplated if certain indicators are revealed.

Effectiveness of video-based psychiatric rehabilitation for patients with early-phase schizophrenia spectrum: A randomized controlled trial.

AIM: This study aimed to establish a comprehensive set of recovery-oriented rehabilitation programs for individuals with schizophrenia, comparing the efficacy of video-based rehabilitation to traditional face-to-face interventions. The primary objective was to assess whether video-based rehabilitation could serve as a viable alternative for individuals with schizophrenia residing in remote areas. METHODS: A randomized controlled study was used to recruit 80 patients with schizophrenia in a stable post-hospitalization stage following discharge. Participants were categorized into three groups: 24 in the control group, 21 in the face-to-face group, and 35 in the remote group. Assessment parameters included psychiatric symptoms, social skills, family function and self-stigma. RESULTS: A total of 68 participants completed the program. The findings indicated significant differences (p < .05) between the control group and intervention group, particularly in the Positive and Negative Syndrome Scale (PANSS) and the Personal and Social Performance Scale (PSP). CONCLUSIONS: The rehabilitation program, tailored for patients in the early phase of the schizophrenia spectrum, demonstrates both effectiveness and feasibility in enhancing clinical symptoms and social functions. Notably, interventions conducted via video proved to be equally effective as those administered face-to-face.

Improved mitochondrial function in the hearts of sarcolipin-deficient dystrophin and utrophin double-knockout mice.

Duchenne muscular dystrophy (DMD) is a progressive muscle-wasting disease associated with cardiomyopathy. DMD cardiomyopathy is characterized by abnormal intracellular Ca2+ homeostasis and mitochondrial dysfunction. We used dystrophin and utrophin double-knockout (mdx:utrn-/-) mice in a sarcolipin (SLN) heterozygous-knockout (sln+/-) background to examine the effect of SLN reduction on mitochondrial function in the dystrophic myocardium. Germline reduction of SLN expression in mdx:utrn-/- mice improved cardiac sarco/endoplasmic reticulum (SR) Ca2+ cycling, reduced cardiac fibrosis, and improved cardiac function. At the cellular level, reducing SLN expression prevented mitochondrial Ca2+ overload, reduced mitochondrial membrane potential loss, and improved mitochondrial function. Transmission electron microscopy of myocardial tissues and proteomic analysis of mitochondria-associated membranes showed that reducing SLN expression improved mitochondrial structure and SR-mitochondria interactions in dystrophic cardiomyocytes. These findings indicate that SLN upregulation plays a substantial role in the pathogenesis of cardiomyopathy and that reducing SLN expression has clinical implications in the treatment of DMD cardiomyopathy.

Ultrasound manifestations and clinical analysis of 50 cases of heterotopic pregnancy.

OBJECTIVE: To investigate the value of ultrasonography in the diagnosis of heterotopic pregnancy and the follow-up. METHODS: A retrospective analysis of 50 cases of clinically diagnosed heterotopic pregnancy in our hospital was performed, the clinical characteristics and ultrasonographic manifestations of the patients were summarized, the reasons for initial ultrasound missed diagnosis and misdiagnosis were analyzed, and the pregnancy outcomes were followed up. RESULTS: Among the 50 cases, the initial ultrasound diagnoses of intrauterine pregnancy were all gestational sac type, 32 cases of ectopic pregnancy were located in the fallopian tube, and 10 cases were located in the uterine horn, 1 case at cervix, and 1 case at caesarean section scar. Forty-one cases were consistent with surgery and/or pathology, representing initial ultrasound diagnosis coincidence rate of about 82%. Six cases were missed in the initial ultrasound examination (12%), and three cases were misdiagnosed (6%). The maximum diameter of the intrauterine gestational sac was 9-48 mm, the average was about 24.90 ± 9.56 mm, the maximum diameter of the ectopic pregnancy gestational sac or mass was 11-63 mm, and the average was about 31.45 ± 13.82 mm (p < 0.05). Intrauterine pregnancy outcomes were followed up, 45 patients with complete data and 5 patients were lost to follow-up. The follow-up rate was about 90%. CONCLUSION: Combining the patient's medical history and clinical characteristics can reduce missed diagnosis and misdiagnosis of heterotopic pregnancy. Ultrasonography has important value in the assessment of intrauterine pregnancy growth and development, and the integrity of maternal uterus.

Predicting intraoperative hemorrhage during curettage treatment of cesarean scar pregnancy using free-breathing GRASP DCE-MRI.

OBJECTIVE: To explore the feasibility of the golden-angle radial sparse parallel (GRASP) dynamic magnetic resonance imaging (MRI) technique in predicting the intraoperative bleeding risk of scar pregnancy. METHODS: A total of 49 patients with cesarean scar pregnancy (CSP) who underwent curettage and GRASP-MRI imaging were retrospectively selected between January 2021 and July 2022. The pharmacokinetic parameters, including Wash-in, Wash-out, time to peck (TTP), initial area under the curve (iAUC), the transfer rate constant (Ktrans), constant flow rate (Kep), and volume of extracellular space (Ve), were calculated. The amount of intraoperative bleeding was recorded by a gynecologist who performed surgery, after which patients were divided into non-hemorrhage (blood loss ≤ 200 mL) and hemorrhage (blood loss > 200 mL) groups. The measured pharmacokinetic parameters were statistically compared using the t-test or Mann-Whitney U test with a significant level set to be p < 0.05. The receiver operating characteristic (ROC) curve was constructed, and the area under the curve (AUC) was calculated to evaluate each parameter's capability in intraoperative hemorrhage subgroup classification. RESULTS: Twenty patients had intraoperative hemorrhage (blood loss > 200 mL) during curettage. The hemorrhage group had larger Wash-in, iAUC, Ktrans, Ve, and shorter TTP than the non-hemorrhage group (all P > 0.05). Wash-in had the highest AUC value (0.90), while Ktrans had the lowest value (0.67). Wash-out and Kep were not significantly different between the two groups. CONCLUSION: GRASP DCE-MRI has the potential to forecast intraoperative hemorrhage during curettage treatment of CSP, with Wash-in exhibiting the highest predictive performance. This data holds promise for advancing personalized treatment. However, further study is required to compare its effectiveness with other risk factors identified through anatomical MRI and ultrasound.

Associations between ALDOB polymorphisms and intrahepatic cholestasis of pregnancy susceptibility in the Chinese Han population.

OBJECTIVES: To research the associations between fructose-bisphosphate aldolase B (ALDOB) gene polymorphisms and intrahepatic cholestasis of pregnancy (ICP) risk. MATERIAL AND METHODS: Whole-genome sequencing (WGS) was performed to detect ALDOB polymorphisms. Five web-available tools were employed to predict the effect of the site variant on the protein. Protein structure comparisons between the reference and ALDOB-modified samples were performed by SWISS-MODEL and Chimera 1.14rc, respectively. RESULTS: We identified 28 genetic variants in the ALDOB gene. When the cut-off value of minor allele frequency (MAF) of loci was 0.001 in four databases, five missense variants, including rs747604233, rs759204107, rs758242037, rs371526091 and rs77718928, were reserved for subsequent analysis. These variants were absent from the 1029 control individuals. The influence of all five variants on protein function was predicted to be damaging by the abovementioned five prediction software programs. Bioinformatics analysis demonstrated that these five missense variants were highly conserved among vertebrates. Compared to the wild-type protein structure, all five mutated protein structures showed a slight change in the chemical bond lengths of the enzyme activity domains. The combined clinical data indicate that the variant group had a significantly older age (p = 0.038), a higher level of indirect bilirubin (IDBIL, p = 0.033), and lower counts of white blood cells (WBCs, p = 7.38E-05) and platelets (PLTs, p = 0.018) than the wild-type group. CONCLUSIONS: This is the first study to examine the associations between ALDOB polymorphisms and ICP disease in 249 Chinese patients with ICP. Our present study expands the understanding of the pathogenesis of ICP.

Carbon nitride quantum dots-modified cobalt phosphate for enhanced photocatalytic H2 evolution.

In the present work, carbon nitride quantum dots (CNQDs)-modified cobalt phosphate (CoPi) composites CNQDs/CoPi-x (x = 1, 2, 3) were prepared at room temperature and characterized by FTIR, XRD, UV-Vis DRS, EIS, SEM, TEM/HR-TEM, XPS, and N2 gas adsorption. The morphologies and surface areas of CNQDs/CoPi-x have no remarkable change after modification of CNQDs, compared with pure CoPi. The obtained CNQDs/CoPi-x shows enhanced activity and stability of photocatalytic H2 evolution compared to pure CoPi using Eosin Y (EY) as a sensitizer and triethanolamine as an electron donor. The CNQDs/CoPi-2 possesses the highest hydrogen evolution rate, 234.5 µmol h-1 g-1 , upon visible light, which outshines that of CoPi by 2.4 times. It was believed that the enhanced photocatalytic performances of the CNQDs/CoPi-2 could result from the boosted electron transfer from radical EY·- to CNQDs/CoPi-2 by the employment of CNQDs; in addition, the visible-light activity of CNQDs contributes to hydrogen evolution. The mechanism of photocatalytic hydrogen production was discussed. This study may contribute toward the development of production of "green hydrogen" using solar.

Triple-Bioinspired Shape Memory Microcavities with Strong and Switchable Adhesion.

Smart adhesives with switchable adhesion have attracted considerable attention for their potential applications in sensors, soft grippers, and robots. In particular, surfaces with controlled adhesion to both solids and liquids have received more attention, because of their wider range of applications. However, surfaces that exhibit controllable adhesion to both solids and liquids often cannot provide sufficient adhesion strength for strong solid adhesion. To overcome this limitation, this study developed a triple-bioinspired shape memory smart adhesive, drawing inspiration from the adhesion structures found in octopus suckers, lotus leaves, and creepers. Our adhesive design incorporates microcavities formed by a shape memory polymer (SMP), which can transition between rubbery and glassy states in response to temperature changes. By leveraging the shape memory effect and the rubber-glass (R-G) phase transition of the SMP, the adhesion of the surface to smooth solids, rough solids, and water droplets could be switched by adjusting the temperature and applied force. Notably, the adhesives designed herein exhibited high adhesion strength (up to 420 kPa) on solids, facilitated by the shape interlocking effect and the negative pressure generated within the microcavities. Furthermore, the programmable transport of solids and liquids can be achieved by utilizing this switchable adhesion. This approach expands the possibilities for designing smart adhesives and holds potential for various applications in different fields.

Coexistence of All-Order Topological States in a Three-Dimensional Phononic Topological Crystalline Insulator.

Classical-wave topological materials lacking intrinsic half-integer spins are less robust while more tunable. Here, we explore a single 3-dimensional phononic topological crystalline insulator that simultaneously exhibits a whole family of first-order quadratic surface, second-order hinge, and third-order corner states within the same bandgap. Such a topological crystalline insulator hosting all-order phases originates from the different topological nature when hierarchically projected onto different facets and lower dimensions, thus free from trivial cladding crystals. Our work offers an ideal platform for either robust wave propagation or localization in on-demand dimensions and may facilitate dimension division multiplexing technology.

Ser14 phosphorylation of Bcl-xL mediates compensatory cardiac hypertrophy in male mice.

The anti-apoptotic function of Bcl-xL in the heart during ischemia/reperfusion is diminished by K-Ras-Mst1-mediated phosphorylation of Ser14, which allows dissociation of Bcl-xL from Bax and promotes cardiomyocyte death. Here we show that Ser14 phosphorylation of Bcl-xL is also promoted by hemodynamic stress in the heart, through the H-Ras-ERK pathway. Bcl-xL Ser14 phosphorylation-resistant knock-in male mice develop less cardiac hypertrophy and exhibit contractile dysfunction and increased mortality during acute pressure overload. Bcl-xL Ser14 phosphorylation enhances the Ca2+ transient by blocking the inhibitory interaction between Bcl-xL and IP3Rs, thereby promoting Ca2+ release and activation of the calcineurin-NFAT pathway, a Ca2+-dependent mechanism that promotes cardiac hypertrophy. These results suggest that phosphorylation of Bcl-xL at Ser14 in response to acute pressure overload plays an essential role in mediating compensatory hypertrophy by inducing the release of Bcl-xL from IP3Rs, alleviating the negative constraint of Bcl-xL upon the IP3R-NFAT pathway.

The growth and developmental of the myodural bridge and its associated structures in the human fetus.

Myodural bridge (MDB) is a dense connective tissue between suboccipital muscle and dura mater. However, there are few reports on the development and maturation of the human MDB. This study aims to explore the developmental relationship between suboccipital muscle and MDB. 30 head and neck specimens from human fetuses (F) ranging from the 12th to 41st week (W) were made into histological sections. The F12W sections showed evidence that the dura mater dominated by fibroblasts, attached to the posterior atlanto-axial membrane (PAAM) which completely sealed the atlanto-axial space. In the F13W stage, myofibrils of the suboccipital muscle fibers increased significantly in number. At the F14W stage, a gap was observed at the caudal end of the PAAM. Numerous myodural bridge-like structures were observed blending into the dura mater through the gap. At the F19W stage, muscle cells mature. Starting at the F21W stage, the MDB were observed as fibroblasts that cross the atlanto-axial interspace and attach to the dura mater. Therefore, the traction generated by the suboccipital muscles seems to promote the maturity of MDB. This study will provide new morphological knowledge to support future research on the function of the human MDB and regulating the development mechanism of MDB.

Diagnostic value of Kaiser score combined with breast vascular assessment from breast MRI for the characterization of breast lesions.

Objectives: The Kaiser scoring system for breast magnetic resonance imaging is a clinical decision-making tool for diagnosing breast lesions. However, the Kaiser score (KS) did not include the evaluation of breast vascularity. Therefore, this study aimed to use KS combined with breast vascular assessment, defined as KS*, and investigate the effectiveness of KS* in differentiating benign from malignant breast lesions. Methods: This retrospective study included 223 patients with suspicious breast lesions and pathologically verified results. The histopathological diagnostic criteria were according to the fifth edition of the WHO classification of breast tumors. The KS* was obtained after a joint evaluation combining the original KS and breast vasculature assessment. The receiver operating characteristic (ROC) curve was used for comparing differences in the diagnostic performance between KS* and KS, and the area under the receiver operating characteristic (AUC) was compared. Results: There were 119 (53.4%) benign and 104 (46.6%) malignant lesions in total. The overall sensitivity, specificity, and accuracy of increased ipsilateral breast vascularity were 69.2%, 76.5%, and 73.1%, respectively. The overall sensitivity, specificity, and accuracy of AVS were 82.7%, 76.5%, and 79.4%, respectively. For all lesions included the AUC of KS* was greater than that of KS (0.877 vs. 0.858, P = 0.016). The largest difference in AUC was observed in the non-mass subgroup (0.793 vs. 0.725, P = 0.029). Conclusion: Ipsilaterally increased breast vascularity and a positive AVS sign were significantly associated with malignancy. KS combined with breast vascular assessment can effectively improve the diagnostic ability of KS for breast lesions, especially for non-mass lesions.

Impact of the bromination of carbazole-based D-π-A organic dyes on their optical and electrochemical properties and visible-light-driven hydrogen evolution.

Brominated dyes, 2C-n (n = 1-5), 3C-4 and 4C-4, were prepared through bromination of three carbazole-based D-π-A dyes, 2C, 3C and 4C with N-bromosuccinimide (NBS). The detailed structures of the brominated dyes were confirmed by 1H NMR spectroscopy and mass spectrometry (MS). The introduction of the Br atom on the 1,8-positon of carbazole moieties led to blueshifted UV-vis and photoluminescence (PL) spectra, increased initial oxidation potentials and enlarged dihedral angles, indicating bromination enhanced non-planarity of the dye molecules. In the hydrogen production experiments, with the increase of the Br content in brominated dyes, the photocatalytic activity increased continuously (except 2C-1). The dye-sensitized Pt/TiO2, 2C-4@T, 3C-4@T and 4C-4@T, exhibited high hydrogen production efficiencies of 655.4, 877.9 and 905.6 µmol h-1 g-1, respectively, which were 4-6-fold higher than those of 2C@T, 3C@T and 4C@T. The enhanced performance of photocatalytic hydrogen evolution was attributed to decreased dye aggregation resulting from the highly non-planar molecular structures of the brominated dyes.

MRI-based scoring model to predict massive hemorrhage during dilatation and curettage in patients with cesarean scar pregnancy.

OBJECTIVE: To construct a scoring model based on MRI signs to predict massive hemorrhage during dilatation and curettage in cesarean scar pregnancy (CSP) patients. MATERIALS AND METHODS: The MRIs of CSP patients admitted to a tertiary referral hospital between February 2020 and July 2022 were retrospectively reviewed. The included patients were randomly assigned to the training and validation cohorts. The univariate and multivariate logistic regression analyses were adopted to identify the independent risk factors for massive hemorrhage (the amount of bleeding ≥ 200 ml) during the dilatation and curettage. A scoring model predicting intraoperative massive hemorrhage was established where each positive independent risk factor was assigned 1 point, and the predictive power of this model was evaluated both in the training and validation cohorts via the receiver operating characteristic curve. RESULTS: A total of 187 CSP patients were enrolled, who were divided into the training cohort (31 in 131 patients had massive hemorrhage) and validation cohort (10 in 56 patients had massive hemorrhage). The independent risk factors for intraoperative massive hemorrhage included cesarean section diverticulum area (OR = 6.957, 95% CI 1.993-21.887; P = 0.001), uterine scar thickness (OR = 5.113, 95% CI 2.086-23.829; P = 0.025) and gestational sac diameter (OR = 3.853, 95% CI 1.103-13.530; P = 0.025). A scoring model with a total point of 3 was developed and the CSP patients were divided into low-risk (Total points < 2) and high-risk groups (Total points ≥ 2) for intraoperative massive hemorrhage accordingly. This model possessed high prediction performance both in the training cohort (area under the curve [AUC] = 0.896, 95% CI 0.830-0.942) and validation cohort (AUC = 0.915, 95% CI 0.785-1.000). CONCLUSION: We first constructed a MRI-based scoring model for predicting intraoperative massive hemorrhage in CSP patients, which could help the decision-making of the patients' therapy strategies. Low-risk patients can be cured by D&C alone to reduce the financial burden, while high-risk patients require more adequate preoperative preparation or consideration of changing surgical approaches to reduce bleeding risk.

Remodeled connexin 43 hemichannels alter cardiac excitability and promote arrhythmias.

Connexin-43 (Cx43) is the most abundant protein forming gap junction channels (GJCs) in cardiac ventricles. In multiple cardiac pathologies, including hypertrophy and heart failure, Cx43 is found remodeled at the lateral side of the intercalated discs of ventricular cardiomyocytes. Remodeling of Cx43 has been long linked to spontaneous ventricular arrhythmia, yet the mechanisms by which arrhythmias develop are still debated. Using a model of dystrophic cardiomyopathy, we previously showed that remodeled Cx43 function as aberrant hemichannels (non-forming GJCs) that alter cardiomyocyte excitability and, consequently, promote arrhythmias. Here, we aim to evaluate if opening of remodeled Cx43 can serve as a general mechanism to alter cardiac excitability independent of cellular dysfunction associated with a particular cardiomyopathy. To address this issue, we used a genetically modified Cx43 knock-in mouse (S3A) that promotes cardiac remodeling of Cx43 protein without apparent cardiac dysfunction. Importantly, when S3A mice were subjected to cardiac stress using the ß-adrenergic agonist isoproterenol (Iso), they displayed acute and severe arrhythmias, which were not observed in WT mice. Pretreatment of S3A mice with the Cx43 hemichannel blocker, Gap19, prevented Iso-induced abnormal electrocardiographic behavior. At the cellular level, when compared with WT, Iso-treated S3A cardiomyocytes showed increased membrane permeability, greater plasma membrane depolarization, and Ca2+ overload, which likely caused prolonged action potentials, delayed after depolarizations, and triggered activity. All these cellular dysfunctions were also prevented by Cx43 hemichannel blockers. Our results support the notion that opening of remodeled Cx43 hemichannels, regardless of the type of cardiomyopathy, is sufficient to mediate cardiac-stress-induced arrhythmogenicity.

Deficiency of mitochondrial calcium uniporter abrogates iron overload-induced cardiac dysfunction by reducing ferroptosis.

Iron overload associated cardiac dysfunction remains a significant clinical challenge whose underlying mechanism(s) have yet to be defined. We aim to evaluate the involvement of the mitochondrial Ca2+ uniporter (MCU) in cardiac dysfunction and determine its role in the occurrence of ferroptosis. Iron overload was established in control (MCUfl/fl) and conditional MCU knockout (MCUfl/fl-MCM) mice. LV function was reduced by chronic iron loading in MCUfl/fl mice, but not in MCUfl/fl-MCM mice. The level of mitochondrial iron and reactive oxygen species were increased and mitochondrial membrane potential and spare respiratory capacity (SRC) were reduced in MCUfl/fl cardiomyocytes, but not in MCUfl/fl-MCM cardiomyocytes. After iron loading, lipid oxidation levels were increased in MCUfl/fl, but not in MCUfl/fl-MCM hearts. Ferrostatin-1, a selective ferroptosis inhibitor, reduced lipid peroxidation and maintained LV function in vivo after chronic iron treatment in MCUfl/fl hearts. Isolated cardiomyocytes from MCUfl/fl mice demonstrated ferroptosis after acute iron treatment. Moreover, Ca2+ transient amplitude and cell contractility were both significantly reduced in isolated cardiomyocytes from chronically Fe treated MCUfl/fl hearts. However, ferroptosis was not induced in cardiomyocytes from MCUfl/fl-MCM hearts nor was there a reduction in Ca2+ transient amplitude or cardiomyocyte contractility. We conclude that mitochondrial iron uptake is dependent on MCU, which plays an essential role in causing mitochondrial dysfunction and ferroptosis under iron overload conditions in the heart. Cardiac-specific deficiency of MCU prevents the development of ferroptosis and iron overload-induced cardiac dysfunction.