BACKGROUND

Perimyocarditis due to inflammation of the pericardium and myocardium results in myocellular damage. Myocarditis, or myocardial inflammation, occurs after cardiac injury. Gallbladder edema, in the absence of cholecystitis, may occur in numerous conditions including cardiac inflammation.

A 28-year-old previously healthy female presented with chest pain, orthopnea, exertional dyspnea and a history of fever. She also reported intermittent right upper quadrant pain. Physical exam revealed a pericardial friction rub. Electrocardiogram (ECG) showed sinus rhythm with nonspecific ST-T changes; troponin I was elevated. Echocardiography demonstrated segmental wall motion abnormalities, pericardial thickening and preserved systolic function. Initially managed as acute coronary syndrome, she was later diagnosed with perimyocarditis. On the second hospital day, she developed recurrence of right upper quadrant abdominal pain. Abdominal ultrasound revealed gallbladder edema with pericholecystic fluid, but no stones. Liver enzymes were elevated. Acalculous cholecystitis was considered and cholecystostomy offered instead due to aspirin therapy. However, repeat imaging showed resolution of cardiac and gallbladder findings, and surgery was deferred. Cardiac MRI postdischarge was unremarkable.

Perimyocarditis may present with gallbladder edema mimicking acalculous cholecystitis, potentially leading to unnecessary surgical intervention. This case emphasizes the importance of considering cardiac etiologies in atypical abdominal presentations.

OBJECTIVES: To investigate the mechanism through which N-acetylneuraminic acid (Neu5Ac) exacerbates hypoxia/reoxygenation (H/R) injury in rat cardiomyocytes (H9C2 cells). METHODS: H9C2 cells were cultured in hypoxia and glucose deprivation for 8 h followed by reoxygenation for different durations to determine the optimal reoxygenation time. Under the optimal H/R protocol, the cells were treated with 0, 5, 10, 20, 30, 40, 50, and 60 mmol/L Neu5Ac during reoxygenation to explore the optimal drug concentration. The cells were then subjected to H/R injury followed by treatment with Neu5Ac, Fer-1 (a ferroptosis inhibitor), or both. The changes in SOD activity, intracellular Fe²⁺ and lipid ROS levels in the cells were evaluated, and the cellular expressions of Nrf2, GPX4, HO-1, FSP1, and xCT proteins were detected using Western blotting. RESULTS: Following hypoxia and glucose deprivation for 8 h, the cells with reoxygenation for 6 h, as compared with other time lengths of reoxygenation except for 9 h, showed the lowest expression levels of Nrf2, GPX4, HO-1, and FSP1 proteins (P<0.001). Neu5Ac treatment of dose-dependently decreased the viability of the cells with H/R injury with an IC₅₀ of 30.07 mmol/L. Reoxygenation for 3 h with normal glucose supplementation and a Neu5Ac concentration of 30 mmol/L were selected as the optimal conditions in the subsequent experiments. The results showed that Neu5Ac could significantly increase SOD activity, Fe²⁺ and lipid ROS levels and reduce Nrf2, GPX4, HO-1, and FSP1 protein expressions in H9C2 cells with H/R injury, but its effects were significantly attenuated by treatment with Fer-1. CONCLUSIONS Neu5Ac exacerbates ferroptosis of myocardial cells with H/R injury by inhibiting the Nrf2 axis to promote the production of ROS and lipid ROS.
Ferroptosis/drug effects* ; Myocytes, Cardiac/cytology* ; Animals ; NF-E2-Related Factor 2/metabolism* ; Rats ; N-Acetylneuraminic Acid/pharmacology* ; Cell Hypoxia ; Reactive Oxygen Species/metabolism* ; Cell Line ; Myocardial Reperfusion Injury/metabolism*

OBJECTIVES: To explore the mechanism that mediate the therapeutic effect of quercetin on heart failure. METHODS: We searched the TCMSP and Swiss ADME databases for the therapeutic targets of quercetin and retrieved heart failure targets from the Genecards and OMIM databases. The intersecting targets were analyzed with GO and KEGG pathway analysis using DAVID database, and the key genes were identified via PPI analysis. Molecular docking between the core targets and quercetin was performed using PyMOL and AutoDock Tools. In a heart failure model established in H9C2 cardiomyocytes by treatment with isoproterenol, the effect of quercetin on the expressions of the MAPK signaling pathway was tested. RESULTS: A total of 60 intersecting targets were identified. Enrichment analysis revealed that quercetin may inhibit heart failure through the MAPK signaling pathway. The core genes, including AMPK3 and BCL-2, were identified as potential key regulators in quercetin-mediated improvement of heart failure. Cellular experiments demonstrated that quercetin significantly reduced isoproterenol-induced apoptosis of cardiomyocytes in a dose-dependent manner and obviously decreased the Bax/Bcl-2 ratio and the expression levels of caspase-3, ERK and p38 in the cells. CONCLUSIONS Quercetin improves heart failure possibly by inhibiting cardiomyocyte apoptosis through the MAPK signaling pathway.
Quercetin/pharmacology* ; Myocytes, Cardiac/drug effects* ; Heart Failure/metabolism* ; Apoptosis/drug effects* ; MAP Kinase Signaling System/drug effects* ; Rats ; Animals ; Isoproterenol

OBJECTIVES: To investigate the effects of quercetin on cuproptosis and L-type calcium currents in the myocardium of diabetic rats. METHODS: Forty SD rats were randomized into control group and diabetic model groups. The rat models of diabetes mellitus (DM) induced by high-fat and high-sugar diet combined with streptozotocin (STZ) injection were further divided into DM model group, quercetin treatment group, and empagliflozin treatment group (n=10). Blood glucose and body weight were measured every other week, and cardiac function of the rats was evaluated using echocardiography. HE staining, Sirius red staining, and wheat germ agglutinin (WGA) analysis were used to observe the changes in myocardial histomorphology, and serum copper levels and myocardial FDX1 expression were detected. In cultured rat cardiomyocyte H9c2 cells with high-glucose exposure, the effects of quercetin and elesclomol, alone or in combination, on intracellular CK-MB and LDH levels and FDX1 expression were assessed, and the changes in L-type calcium currents were analyzed using patch-clamp technique. RESULTS: The diabetic rats exhibited elevated blood glucose, reduced body weight, impaired left ventricular function, increased serum copper levels and myocardial FDX1 expression, decreased L-type calcium currents, and prolonged action potential duration. Quercetin and empagliflozin treatment significantly lowered blood glucose, improved body weight, and restored cardiac function of the diabetic rats, and compared with empagliflozin, quercetin more effectively reduced serum copper levels, downregulated FDX1 expression, and enhanced myocardial L-type calcium currents in diabetic rats. In H9c2 cells, high glucose exposure significantly increased myocardial expressions of FDX1, CK-MB and LDH, which were effectively lowered by quercetin treatment; Elesclomol further elevated FDX1, CK-MB and LDH levels in the exposed cells, and these changes were not significantly affected by the application of quercetin. CONCLUSIONS Quercetin ameliorates myocardial injury in diabetic rats possibly by suppressing myocardial cuproptosis signaling and restoring L-type calcium channel activity.
Animals ; Quercetin/pharmacology* ; Calcium Channels, L-Type/metabolism* ; Diabetes Mellitus, Experimental/metabolism* ; Rats, Sprague-Dawley ; Rats ; Myocytes, Cardiac/drug effects* ; Myocardium/pathology* ; Male

OBJECTIVES: To explore the mechanism of Circ-MYOCD back-splicing and its regulatory role in myocardial hypertrophy. METHODS: Sanger sequencing and RNase R assays were performed to verify the circularity and stability of Circ-MYOCD, whose subcellular distribution was determined by nuclear-cytoplasmic fractionation. Bioinformatics analysis and mass spectrometry from pull-down assays were conducted to predict the RNA-binding proteins (RBPs) interacting with Circ-MYOCD. In rat cardiomyocytes H9C2 cells, the effects of HNRNPH1 and HNRNPL knockdown and overexpression on Circ-MYOCD back-splicing were evaluated. In a H9C2 cell model of angiotensin II (Ang II)-induced myocardial hypertrophy, the expression of HNRNPH1 was detected, the effects of HNRNPH1 knockdown and overexpression on progression of myocardial hypertrophy were assessed, and the regulatory effect of HNRNPH1 on Circ-MYOCD back-splicing was analyzed. RESULTS: Sanger sequencing confirmed that the junction primers could amplify the correct Circ-MYOCD sequence. RNase R and nuclear-cytoplasmic fractionation assays showed that Circ-MYOCD was stable and predominantly localized in the cytoplasm. Bioinformatics analysis and mass spectrometry from the Circ-MYOCD pull-down assay identified HNRNPH1 and HNRNPL as the RBPs interacting with Circ-MYOCD. In H9C2 cells, HNRNPH1 knockdown significantly enhanced while its overexpression inhibited Circ-MYOCD back-splicing; HNRNPH1 overexpression obviously increased the expressions of myocardial hypertrophy markers ANP and BNP, while its knockdown produced the opposite effect. In Ang II-induced H9C2 cells, which exhibited a significant increase of HNRNPH1 expression and increased expressions of ANP and BNP, HNRNPH1 knockdown obviously increased Circ-MYOCD expression, decreased MYOCD expression and lowered both ANP and BNP expressions. CONCLUSIONS HNRNPH1 regulates Circ-MYOCD back-splicing to influence the progression of myocardial hypertrophy.
Animals ; Rats ; RNA, Circular/genetics* ; Cardiomegaly/metabolism* ; Myocytes, Cardiac/metabolism* ; Heterogeneous-Nuclear Ribonucleoprotein Group F-H/metabolism* ; Cell Line ; RNA Splicing ; Angiotensin II ; RNA-Binding Proteins

OBJECTIVES: To investigate the effect of cardiomyocytes-derived exosomes on lipopolysaccharide (LPS)-induced cardiomyocyte injury and its mechanism. METHODS: Exosomes isolated from rat cardiomyocytes with or without LPS treatment were co-cultured with rat lymphocytes. The lymphocytes with or without exosome treatment were co-cultured with LPS-induced rat cardiomyocytes for 48 h. Cardiomyocyte apoptosis was detected using flow cytometry, and the expressions of apoptosis marker proteins and the PI3K/AKT pathway proteins were detected using Western blotting. The effects of human recombinant IL-38 protein on apoptosis and protein expressions in LPS-induced cardiomyocytes were examined. RESULTS: Compared with normal cardiomyocyte-derived exosomes, the exosomes from LPS-induced cardiomyocytes significantly enhanced proliferation and increased mRNA and protein expression levels of IL-38 in rat lymphocytes. Bioinformatics analysis suggested that miR-1275 in the exosome played a key role in LPS-induced cardiomyocyte injury, and in dual luciferase reporter gene assay, miR-1275 mimics significantly increased luciferase activity of WT-IL-38. Co-culture with lymphocytes treated with exosomes from LPS-induced cardiomyocytes significantly inhibited apoptosis of LPS-induced cardiomyocytes. Treatment with recombinant IL-38 also effectively lowered apoptosis rate of LPS-induced cardiomyocytes, reduced cellular expression of Bax protein, and increased the protein expression levels of Bcl-2, p-PI3K and p-AKT. CONCLUSIONS miR-1275 in exosomes derived from LPS-induced cardiomyocytes mediates IL-38 up-regulation expression in lymphocytes to activate the PI3K/AKT pathway and inhibit LPS-induced cardiomyocyte apoptosis.
Apoptosis/drug effects* ; MicroRNAs/metabolism* ; Myocytes, Cardiac/metabolism* ; Animals ; Lipopolysaccharides ; Rats ; Exosomes/metabolism* ; Up-Regulation ; Interleukins/metabolism* ; Lymphocytes/cytology* ; Cells, Cultured ; Signal Transduction ; Coculture Techniques ; Phosphatidylinositol 3-Kinases/metabolism* ; Rats, Sprague-Dawley ; Humans ; Proto-Oncogene Proteins c-akt/metabolism*

OBJECTIVES: To verify whether hesperetin (Hes) alleviates doxorubicin (DOX)-induced cardiotoxicity by reducing inflammation via regulating the AMPK/NLRP3 pathway. METHODS: C57/bl6 mice and H9c2 cells treated with DOX to mimic cardiotoxicity were randomly divided into Sham (or control) group, DOX group, DOX+Hes group, DOX+Hes+compound C (CC, an AMPK inhibitor) group. Cardiac function and myocardial pathologies of the mice were evaluated, and the changes in H9c2 cell morphology and viability were assessed. Lactate dehydrogenase (LDH) activity in mouse myocardial tissues and H9c2 cells was measured using ELISA, and H9c2 cell apoptosis was detected with TUNEL staining. In both H9c2 cells and the myocardial tissues of the mice, cellular expression levels of TNF-α, IL-6 and IL-1β mRNAs and cleaved caspase-3, Bcl2, Bax, IL-1β, IL-18, p-AMPK, AMPK, p-mTOR, mTOR, NLRP3, ASC and caspase-1 proteins were detected using RT-PCR and Western blotting. RESULTS: DOX treatment caused cell swelling, decreased cell viability and increased LDH activity in H9c2 cells, resulting also in significantly increased cell apoptosis and cleaved caspase-3 expression and decreased Bcl2/Bax ratio. The DOX-treated mice showed obvious myocardial fiber swelling and inflammatory infiltration, decreased cardiac function and significantly increased myocardial LDH activity. In H9c2 cells, DOX treatment significantly increased the mRNA expressions of TNF-α, IL-6 and IL-1β and protein expressions of IL-1β and IL-18, lowered the expressions of p-AMPK and p-mTOR, and increased the expressions of NLRP3, ASC and caspase-1. Hes treatment obviously reduced these toxic effects of DOX in H9c2 cells, but its protective effects were blocked by application of compound C. CONCLUSIONS Hes reduces DOX-induced cardiotoxicity by inhibiting inflammation via regulating the AMPK/NLRP3 pathway.
Animals ; Doxorubicin/toxicity* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Mice, Inbred C57BL ; Mice ; Signal Transduction/drug effects* ; Cardiotoxicity ; AMP-Activated Protein Kinases/metabolism* ; Apoptosis/drug effects* ; Cell Line ; Myocytes, Cardiac/drug effects* ; Rats

OBJECTIVES: To explore the mechanism of cinnamic acid (CA) for improving doxorubicin-induced myocardial injury (DIC) in mice. METHODS: Network pharmacology analysis was used to obtain the key targets of CA and DIC. Male C57BL/6J mice were randomized into Sham, DOX, CA (25, 50 and 100 mg/kg)+DOX, and CA+Ferrostatin-1+DOX groups, and their myocardial function and pathology were examined by echocardiography and HE staining. Serum levels of CK-MB, LDH, MDA, IL-6, TNF‑α and myocardial ROS level were detected, and the expression levels of TLR4 and ferroptosis pathway proteins in myocardial tissue were detected by Western blotting. Cultured murine cardiomyocytes (HL-1 cells) with or without transfection with a small interfering RNA targeting TLR4 (si-TLR4) were treated with DOX or Erastin, and the cellular ROS content was measured by DCFH-DA staining; the expression level of GPX4 was detected using immunofluorescence staining. RESULTS: Network pharmacology analysis suggested that CA may improve DIC through TLR4 signaling. DOX treatment caused obvious myocardial injury in mice, which showed significantly increased serum levels of CK-MB, LDH, MDA, IL-6, TNF-α and myocardial ROS level with decreased myocardial levels of SLC7A11 and GPX4 proteins and increased levels of TLR4 and PTGS2 proteins. All these changes in the mouse models were significantly alleviated by treatment with CA, and the mice receiving CA or ferrostatin-1 treatment exhibited increased myocardial expressions of SLC7A11 and GPX4 proteins and lowered expressions of TLR4 and PTGS2 proteins. In cultured HL-1 cells, treatment with DOX and Erastin both obviously increased intracellular ROS level and decreased cellular GPX4 expression level, and these changes were strongly attenuated by TLR4 interference. CONCLUSIONS CA, as a potent herbal monomer, can effectively alleviate DIC in mice by inhibiting TLR4-mediated ferroptosis.
Animals ; Ferroptosis/drug effects* ; Toll-Like Receptor 4/metabolism* ; Myocytes, Cardiac/metabolism* ; Mice, Inbred C57BL ; Mice ; Male ; Doxorubicin/adverse effects* ; Cinnamates/pharmacology* ; Signal Transduction ; Reactive Oxygen Species/metabolism*

OBJECTIVES: To investigate the molecular mechanism by which salvianolic acid B (Sal-B) modulates mitochondrial functional homeostasis and alleviates myocardial ischemia-reperfusion (I/R) injury in mice. METHODS: Mouse cardiomyocyte HL-1 cells were pretreated with 5 μmol/L Sal-B with or without sh-Sirt1 transfection before exposure to hypoxia-reoxygenation (HR), and the changes in ATP production, mitochondrial superoxide activity, substrate oxidation level were evaluated. In the animal experiment, 36 C57BL/6J mice were randomized into 3 groups (n=12) for sham operation or ligation of the left anterior coronary artery to induce myocardial I/R injury with or without intravenous injection of Sal-B+I/R (50 mg/kg). In the rescue experiment, 60 adult C57BL/6J mice were randomized into 5 groups (n=12): sham-operated group, myocardial I/R group, Sal-B+I/R group, I/R+Sal-B+Sirt1fl/fl group, and I/R+Sal-B+cKO-Sirt1 group. Myocardial injury was evaluated with HE staining, and cardiac function was assessed by measurement of the ejection fraction and fractional shortening using echocardiography. RESULTS: In HL-1 cells with HR injury, Sal-B pretreatment significantly increased cellular ATP production, reduced mitochondrial superoxide anion levels, and enhanced oxygen consumption level. In the mouse models of myocardial I/R injury, Sal-B pretreatment markedly ameliorated I/R-induced structural disarray of the cardiac myocytes and improved cardiac ejection. Cycloheximide chase with Western blotting and ubiquitination assays after Sirt1-IP showed that Sal-B significantly inhibited Sirt1 degradation in HL-1 cells. Sirt1 knock-down reversed Sal-B-induced increases in ATP production, reduction in superoxide, and elevation of OCR in HL-1 cells. Cardiomyocyte-specific Sirt1 knockout obviously reversed Sal-B-mediated improvement in cardiac ejection function and myocardial structure damage in mice with myocardial I/R injury. CONCLUSIONS Sal-B promotes mitochondrial functional homeostasis in cardiomyocytes with HR injury and improves cardiac function in mice after myocardial I/R by inhibiting Sirt1 protein degradation.
Animals ; Sirtuin 1/metabolism* ; Myocardial Reperfusion Injury/physiopathology* ; Mice, Inbred C57BL ; Mice ; Myocytes, Cardiac/drug effects* ; Benzofurans/pharmacology* ; Homeostasis/drug effects* ; Male ; Mitochondria/drug effects* ; Depsides

METHODS: Cardiac organoids derived from the self-assembled human induced pluripotent stem cells were constructed by regulating the Wnt signaling pathway. Flow cytometry was used to detect the proportion of cardiomyocytes in the cardiac organoids, and RT-qPCR was employed to detect the mRNA expressions. Immunofluorescence staining was used to detect the protein expressions of TNNT2, CD31, and vimentin. The beating amplitude of the cardiac organoids was determined with calcium transient. In vitro myocardial injury models and ischemia-reperfusion models were established, and the cell injuries were examined using Masson staining. TUNEL staining and calcium transient detection were used to evaluate the adverse effects of doxorubicin and trastuzumab in the cardiac organoids. RESULTS: The cardiac organoids began to beat on the 8th day of culture and consisted of 32.4% cardiomyocytes with high expressions of the myocardial markers TNNT2, NKX2.5, RYR2 and KCNJ2. No significant differences in morphological size, beating frequency, proportion of cardiomyocytes, or myocardial contractility were observed in the cardiac organoids differentiated from different batches. These cardiac organoids could be maintained in in vitro culture conditions for at least 50 days. Captopril treatment could obviously alleviate liquid nitrogen-induced myocardial injury in the cardiac organoids. Hypoxia/reoxygenation induced ischemia-reperfusion injury and promoted myocardial fibrosis and apoptosis in the cardiac organoids. Treatment with doxorubicin for 24 h resulted in significantly increased cell death and reduced beating frequency and cell viability in the cardiac organoids in a dose-dependent manner. Trastuzumab significantly impaired the contractile and calcium handling abilities of the cardiac organoids. CONCLUSIONS Cardiac organoids derived from human induced pluripotent stem cells have been successfully constructed and can be used for cardiac disease modeling and drug evaluation.
Humans ; Induced Pluripotent Stem Cells/cytology* ; Organoids/cytology* ; Myocytes, Cardiac/cytology* ; Cell Differentiation ; Heart Diseases