Role and mechanism of miR-871-3p/Megf8 in regulating formaldehyde-induced cardiomyocyte inflammation and congenital heart disease.

OBJECTIVE AND DESIGN: We aimed to investigate the molecular mechanism underlying formaldehyde (FA)-induced congenital heart disease (CHD) using in vitro and in vivo models. MATERIALS AND SUBJECTS: Neonatal rat heart tissues and H9C2 cells were used for in vitro studies, while FA-exposed new-born rats were used for in vivo studies. TREATMENT: H9C2 cells were exposed to FA concentrations of 0, 50, 100 and 150 µM/mL for 24 h. METHODS: Whole transcriptome gene sequencing identified differentially expressed miRNAs in neonatal rat heart tissues, while Real-time quantitative PCR (RT-qPCR) assessed miR-871-3p and Megf8 expression. RNA pull-down and dual-luciferase reporter assays determined miR-871-3p and Megf8 relationships. Inflammatory cytokine expression was assessed by western blotting. A FA-induced CHD model was used to validate miR-871-3p regulatory effects in vivo. RESULTS: We identified 89 differentially expressed miRNAs, with 28 up-regulated and 61 down-regulated (fold change ≥ 2.0, P < 0.05). Inflammation (interleukin) and signalling pathways were found to control FA-induced cardiac dysplasia. miR-871-3p was upregulated in FA-exposed heart tissues, modulated inflammation, and directly targeted Megf8. In vivo experiments showed miR-871-3p knockdown inhibited FA-induced inflammation and CHD. CONCLUSION: We demonstrated miR-871-3p's role in FA-induced CHD by targeting Megf8, providing potential targets for CHD intervention and improved diagnosis and treatment strategies.

Phlorizin, a novel caloric restriction mimetic, stimulates hypoxia and protects cardiomyocytes through activating autophagy via modulating the Hif-1α/Bnip3 axis in sepsis-induced myocardial dysfunction.

BACKGROUND: Sepsis is a systemic inflammatory syndrome that can lead to multiple organ dysfunction and life-threatening complications. Sepsis-induced myocardial dysfunction (SIMD) has been confirmed to be present in half of patients with septic shock, increasing their mortality rate to 70-90%. The pathogenesis of SIMD is complex, and no specific clinical treatment has yet been developed. Caloric restriction mimetics (CRM), compounds that simulate the biochemical and functional properties of CR, can improve cardiovascular injury by activating autophagy. This study investigated the effect of a new type of CRM which can induce hypoxia, the SGLT nonspecific inhibitor phlorizin on SIMD. MATERIALS AND METHODS: In vivo, phlorizin was administered at 1 mg/kg/day intragastrically for 28 days. In vitro, AC16 was treated with 120 µM phlorizin for 48 h. Echocardiography was used to assess cardiac function. Myocardial injury markers were detected in serum and cell supernatant. Western blotting was employed to detect changed proteins associated with apoptosis and autophagy. Immunofluorescence, immunohistochemistry, co-immunoprecipitation, molecular docking, and other methods were also used to illustrate cellular changes. RESULTS: In vivo, phlorizin significantly improved the survival rate and cardiac function after sepsis injury, reduced markers of myocardial injury, inhibited myocardial apoptosis and oxidative stress, and promoted autophagy. In vitro, phlorizin alleviated the apoptosis of AC16, as well as inhibited oxidative stress and apoptotic enzyme activity. Phlorizin acts on autophagy at multiple sites through low energy (activation of AMPK) and hypoxia (release of Beclin-1 by Hif-1α/Bnip3 axis), promoting the formation and degradation of autophagosomes. CONCLUSION: We indicated for the first time that phlorizin could inhibit glucose uptake via GLUT-1 and conforms to the metabolic characteristics of CRM, it can induce the hypoxic transcriptional paradigm. In addition, it inhibits apoptosis and improves SIMD by promoting autophagy generation and unobstructing autophagy flux. Moreover, it affects autophagy by releasing Beclin-1 through the Hif-1α/Bnip3 axis.

Development, Histological, and Ultrastructural Evaluation of Sheep Hyperimmune Serum Therapy for COVID-19 / Desarrollo, Evaluación Histológica y Ultraestructural de la Terapia con Suero Hiperinmune de Oveja para COVID-19

SUMMARY: In response to the threat posed by new variants of SARS-CoV-2 and the urgent need for effective treatments in the absence of vaccines, the aim of this study was to develop a rapid and cost-effective hyperimmune serum (HS) derived from sheep and assess its efficacy. The utilization of a halal-certified, easily maintained in certain geographic regions, easy-to-handle animal such as sheep could provide a viable alternative to the expensive option of horses. Sheep were immunized with a whole inactivated SARS-CoV- 2 antigen to produce HS, which was evaluated for neutralizing potency using the PRNT50 assay. K18-hACE2 transgenic mice (n=35) were divided into three groups: control, SARS-CoV-2 exposure through inhalation, and SARS-CoV-2 exposed mice treated with HS. HS efficacy was assessed through serum proinflammatory cytokine levels, qRT-PCR analysis, histopathological examination of lungs and hearts, and transmission electron microscopy. Purified HS exhibited significant neutralizing activity (1/24,576). The SARS-CoV-2+HS group showed lower levels of TNF-α, IL-10, and IL-6 (P<0.01) and relatively lower levels of MCP-1 compared to the SARS-CoV-2 group. HS prevented death, reduced viral RNA levels in the lungs and hearts, protected against severe interstitial pneumonia, preserved lung tissue integrity, and prevented myocyte damage, while the SARS-CoV-2 group exhibited viral presence in the lungs. This study successfully developed a sheep-derived HS against the entire SARS-CoV-2 virus, resulting in a significant reduction in infection severity, inflammation, and systemic cytokine production. The findings hold promise for treating severe COVID-19 cases, including emerging viral variants, and immunocompromised patients.

En respuesta a la amenaza que suponen las nuevas variantes del SARS-CoV-2 y la urgente necesidad de tratamientos eficaces en ausencia de vacunas, el objetivo de este estudio fue desarrollar un suero hiperinmune (HS) rápido y rentable derivado de ovejas. y evaluar su eficacia. La utilización de un animal con certificación halal, de fácil mantenimiento en determinadas regiones geográficas y de fácil manejo, como las ovejas, podría proporcionar una alternativa viable a la costosa opción de los caballos. Las ovejas fueron inmunizadas con un antígeno de SARS-CoV-2 completamente inactivado para producir HS, cuya potencia neutralizante se evaluó mediante el ensayo PRNT50. Los ratones transgénicos K18-hACE2 (n = 35) se dividieron en tres grupos: control, exposición al SARS-CoV-2 mediante inhalación y ratones expuestos al SARS-CoV-2 tratados con HS. La eficacia de HS se evaluó mediante niveles de citoquinas proinflamatorias en suero, análisis qRT-PCR, examen histopatológico de pulmones y corazones y microscopía electrónica de transmisión. El HS purificado exhibió una actividad neutralizante significativa (1/24,576). El grupo SARS-CoV-2+HS mostró niveles más bajos de TNF-α, IL-10 e IL-6 (P<0,01) y niveles relativamente más bajos de MCP-1 en comparación con el grupo SARS-CoV-2. HS evitó la muerte, redujo los niveles de ARN viral en los pulmones y el corazón, protegió contra la neumonía intersticial grave, preservó la integridad del tejido pulmonar y evitó el daño de los miocitos, mientras que el grupo SARS-CoV-2 exhibió presencia viral en los pulmones. Este estudio desarrolló con éxito un HS derivado de ovejas contra todo el virus SARS-CoV-2, lo que resultó en una reducción significativa de la gravedad de la infección, la inflamación y la producción sistémica de citocinas. Los hallazgos son prometedores para el tratamiento de casos graves de COVID- 19, incluidas las variantes virales emergentes y los pacientes inmunocomprometidos.

Erythropoietin-mediated cardioprotection in hearts subjected to ischemia reperfusion.

Several studies provide evidence that erythropoietin (EPO) could play an important role in the recovery of the heart subjected to ischemia-reperfusion. In this regard, it has been suggested that EPO could be involved in protein kinase B (Akt) activation as a cell survival protein. The aim of the present study was to investigate the effects of EPO on the Akt/glycogen synthase kinase 3 beta (GSK-3ß) pathway in the presence or absence of wortmannin (W, Akt inhibitor) and its relationship with mitochondrial morphology and function preservation in ischemic-reperfused rat hearts. EPO improved the functional recovery of the heart subjected to ischemia-reperfusion, reduced the release of CK and the infarct size, and promoted preservation of the mitochondrial structure. Moreover, it reduced tissue lactate content and preserved glycogen in order to prevent ischemia. The results showed greater Akt activation, accompanied by preservation of swelling and mitochondrial calcium retention capacity, as well as an increase in ATP synthesis capacity. These results were accompanied by an inhibition of GSK-3ß, suggesting regulation of Akt on the opening of the mitochondrial permeability transition pore. All these beneficial effects exerted by acute treatment with EPO were prevented by W. The present study provided novel evidence that EPO not only enhances intrinsic activation of Akt during myocardial ischemia-reperfusion but also promotes GSK-3ß inhibition, contributing to mitochondrial structure and function preservation.

Interleukin-37 has A Promising Cardioprotective Effect on Isoproterenol-Induced Myocardial Infarction / La Interleucina-37 tiene un Efecto Cardioprotector Prometedor sobre el Infarto de Miocardio Inducido por Isoproterenol

SUMMARY: The main cause of mortality and disability globally is myocardial infarction (MI). Isoproterenol (ISO), a β-adrenoceptor agonist, has been used to induce rat myocardial necrosis. Whereas interleukin-37 (IL-37) has anti-inflammatory and cytoprotective properties. The study aimed to investigate the potential protective effects of IL-37 administration on cardiac architecture, oxidative stress, and inflammatory markers during ISO-induced MI in rats. Three groups of adult male rats were used in this study, the normal control group (n=8), ISO-induced MI group (n=8) that received isoproterenol hydrochloride (ISO) (100 mg/kg/day, SC, for the first 2 consecutive days), and IL-37-treated group (ISO+IL-37) (n=8) that received recombinant human IL-37 (40 µg/kg /day, intraperitoneally, for 2 weeks during and after ISO injections. Heart rate (HR.) and ECG changes were monitored. Some oxidative stress markers such as superoxide dismutase (SOD), nitric oxide (NOx), malondialdehyde (MDA), and glutathione (GSH) tissue levels in the tissue homogenate were assayed. Interleukin- 6 (IL-6), tumor necrosis factor- α (TNF-α), caspase-8, P53, and C- reactive protein (CRP) were among the inflammatory markers examined. In addition, serum levels of creatinine kinase (CK-MB) and lactate dehydrogenase (LDH) were analyzed to evaluate the myocardial injury. For histological analysis, tissues were sectioned, fixed in paraffin, and stained with hematoxylin and eosin (H&E), Masson Trichrome and, immunohistochemical against NF-kB, TNF-α, and Caspase-9. IL-37 improved ECG changes, cardiac enzyme markers, and some inflammatory markers of oxidative stress in ISO-induced MI. It also improved the histopathological and immunohistochemical changes in MI. In conclusion: IL-37 might be a promising therapeutic modality in myocardial infarction.

La principal causa de mortalidad y discapacidad a nivel mundial es el infarto de miocardio (IM). El isoproterenol (ISO), un agonista de los receptores adrenérgicos β, se ha utilizado para inducir necrosis miocárdica en ratas. Mientras que la interleucina-37 (IL-37) tiene propiedades antiinflamatorias y citoprotectoras. El estudio tuvo como objetivo investigar los posibles efectos protectores de la administración de IL-37 en la arquitectura cardíaca, el estrés oxidativo y los marcadores inflamatorios durante el infarto de miocardio inducido por ISO en ratas. En este estudio se utilizaron tres grupos de ratas macho adultas, el grupo control normal (n=8), el grupo con IM inducido por ISO (n=8) que recibió clorhidrato de isoproterenol (ISO) (100 mg/kg/día, SC, durante los primeros 2 días consecutivos) y el grupo tratado con IL-37 (ISO+IL- 37) (n=8) que recibió IL-37 humana recombinante (40 µg/kg/día, por vía intraperitoneal, durante 2 semanas durante y después de las inyecciones de ISO. Se monitorearon la frecuencia cardíaca (FC) y los cambios en el ECG. Se analizaron algunos marcadores de estrés oxidativo como la superóxido dismutasa (SOD), el óxido nítrico (NOx), el malondialdehído (MDA) y los niveles tisulares de glutatión (GSH) en el homogeneizado de tejido. La interleucina-6 (IL-6), el factor de necrosis tumoral-α (TNF-α), la caspasa-8, la P53 y la proteína C reactiva (CRP) se encontraban entre los marcadores inflamatorios examinados. Se analizaron los niveles de creatinoquinasa (CK-MB) y lactato deshidrogenasa (LDH) para evaluar la lesión miocárdica; para el análisis histológico se seccionaron los tejidos, se fijaron en parafina y se tiñeron con hematoxilina y eosina (H&E), Tricromo de Masson e inmunohistoquímica contra NF-kB, TNF-α y Caspasa-9. IL-37 mejoró los cambios de ECG, los marcadores de enzimas cardíacas y algunos marcadores inflamatorios de estrés oxidativo en el IM inducido por ISO. Además mejoró los cambios histopatológicos e inmunohistoquímicos en MI. En conclusión: la IL-37 podría ser una modalidad terapéutica prometedora en el infarto de miocardio.

Morphological and Functional Analysis of Cardiac Ameliorations in Elderly Rats Supplemented with a Magnolol Extract Complex / Análisis Morfológico y Funcional de las Mejoras Cardíacas en Ratas Ancianas Suplementadas con un Complejo de Extracto de Magnolol

SUMMARY: Magnolia bark extract supplementation has an anti-oxidative role in mammalians. However, its role in physiological aged-associated heart insufficiency is not known yet. Therefore, we investigated the effects of a magnolia bark complex, including magnolol and honokiol components (MAHOC), in elderly rat hearts (24-month-old aged group). One group of aged rats was supplemented with MAHOC (400 mg/kg/d, for 12 weeks) besides the standard rat diet while the second group of elderly rats and adult rats (to 6-month- old adult-group) were only fed with the standard rat diet. The morphological analysis using light microscopy has shown marked myofibrillar losses, densely localized fibroblasts, vacuolizations, infiltrated cell accumulations, and collagen fibers in the myocardium of the elderly rats compared to the adults. We also detected a markedly increased amount of degenerated cardiomyocytes including the euchromatic nucleus. The MAHOC supplementation of the elderly rats provided marked ameliorations in these abnormal morphological changes in the heart tissue. Furthermore, electrophysiological analysis of electrocardiograms (ECGs) in the supplemented group showed significant attenuations in the prolonged durations of P-waves, QRS-complexes, QT-intervals, and low heart rates compared to the unsupplemented elderly group. The biochemical analysis also showed significant attenuations in the activity of arylesterase and total antioxidant status in the myocardium of the supplemented group. We further determined significant attenuations in the activity of a mitochondrial enzyme succinate dehydrogenase, known as a source of reactive oxygen species (ROS), and the decreased level of ATP/ADP in the heart homogenates of the supplemented group. Moreover, under in vitro conditions by using an aging-mimicked cardiac cell line induced by D-galactose, we demonstrated that MAHOC treatment could provide prevention of depolarization in mitochondria membrane potential and high-level ROS production. Overall, our data presented significant myocardial ameliorations in physiological aging-associated morphological alterations parallel to the function and biochemical attenuations with MAHOC supplementation, at most, through recoveries in mitochondria.

La suplementación con extracto de corteza de magnolia tiene un papel antioxidante en los mamíferos, sin embargo, su rol en la insuficiencia cardíaca asociada al envejecimiento fisiológico aún no se conoce. Por lo anterior, investigamos los efectos de un complejo de corteza de magnolia, incluidos los componentes magnolol y honokiol (MAHOC), en corazones de ratas seniles (grupo de edad de 24 meses). La alimentación de grupo de ratas seniles se complementó con MAHOC (400 mg/kg/d, durante 12 semanas) además de la dieta estándar, mientras que el segundo grupo de ratas seniles y ratas adultas (hasta el grupo de adultos de 6 meses) solo recibió la dieta estándar para ratas. El análisis morfológico mediante microscopía óptica ha mostrado marcadas pérdidas miofibrilares, fibroblastos densamente localizados, vacuolizaciones, acumulaciones de células infiltradas y fibras de colágeno en el miocardio de las ratas seniles en comparación con las adultas. También detectamos una cantidad notablemente mayor de cardiomiocitos degradados, incluido el núcleo eucromático. La suplementación con MAHOC de las ratas seniles proporcionó mejoras marcadas en estos cambios morfológicos anormales en el tejido cardiaco. Por otra parte, el análisis de los electrocardiogramas (ECG) en el grupo suplementado mostró atenuaciones significativas en las duraciones prolongadas de las ondas P, los complejos QRS, los intervalos QT y las frecuencias cardíacas bajas, en comparación con el grupo de ratas seniles sin suplementación alimenticia. El análisis bioquímico también mostró atenuaciones significativas en la actividad de la arilesterasa y el estado antioxidante total en el miocardio del grupo suplementado. Determinamos además atenuaciones significativas en la actividad de la enzima mitocondrial succinato deshidrogenasa, conocida como fuente de especies reactivas de oxígeno (ROS), y la disminución del nivel de ATP/ADP en los homogeneizados de corazón del grupo suplementado. Además, en condiciones in vitro mediante el uso de una línea de células cardíacas, imitando el envejecimiento inducido por D- galactosa, demostramos que el tratamiento con MAHOC podría prevenir la despolarización en el potencial de membrana de las mitocondrias y la producción de ROS de alto nivel. En general, nuestros datos presentaron mejoras miocárdicas significativas en alteraciones morfológicas asociadas con el envejecimiento fisiológico paralelas a la función y atenuaciones bioquímicas con la suplementación con MAHOC, como máximo, a través de recuperaciones en las mitocondrias.

Role of selenoprotein M knockdown in the melatonin antagonism of nickel-induced apoptosis and endoplasmic reticulum stress in mouse heart. / 硒蛋白Mæ•²é™¤åœ¨è¤ªé»‘ç´ æ‹®æŠ—é•è¯±å¯¼çš„å°é¼ å¿ƒè„ç»†èƒžå‡‹äº¡å’Œå† è´¨ç½‘åº”æ¿€ä¸­çš„ä½œç”¨.

The aim of this study was to investigate the role of selenoprotein M (SelM) in endoplasmic reticulum stress and apoptosis in nickel-exposed mouse hearts and to explore the detoxifying effects of melatonin. At 21 d after intraperitoneal injection of nickel chloride (NiCl2) and/or melatonin into male wild-type (WT) and SelM knockout (KO) C57BL/6J mice, NiCl2 was found to induce changes in the microstructure and ultrastructure of the hearts of both WT and SelM KO mice, which were caused by oxidative stress, endoplasmic reticulum stress, and apoptosis, as evidenced by decreases in malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) activity. Changes in the messenger RNA (mRNA) and protein expression of genes related to endoplasmic reticulum stress (activating transcription factor 4 (ATF4), inositol-requiring protein 1 (IRE1), c-Jun N-terminal kinase (JNK), and C/EBP homologous protein (CHOP)) and apoptosis (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase-3, Caspase-9, and Caspase-12) were also observed. Notably, the observed damage was worse in SelM KO mice. Furthermore, melatonin alleviated the heart injury caused by NiCl2 in WT mice but could not exert a good protective effect in the heart of SelM KO mice. Overall, the findings suggested that the antioxidant capacity of SelM, as well as its modulation of endoplasmic reticulum stress and apoptosis, plays important roles in nickel-induced heart injury.

γ-Linolenic acid in maternal milk drives cardiac metabolic maturation.

Birth presents a metabolic challenge to cardiomyocytes as they reshape fuel preference from glucose to fatty acids for postnatal energy production1,2. This adaptation is triggered in part by post-partum environmental changes3, but the molecules orchestrating cardiomyocyte maturation remain unknown. Here we show that this transition is coordinated by maternally supplied γ-linolenic acid (GLA), an 18:3 omega-6 fatty acid enriched in the maternal milk. GLA binds and activates retinoid X receptors4 (RXRs), ligand-regulated transcription factors that are expressed in cardiomyocytes from embryonic stages. Multifaceted genome-wide analysis revealed that the lack of RXR in embryonic cardiomyocytes caused an aberrant chromatin landscape that prevented the induction of an RXR-dependent gene expression signature controlling mitochondrial fatty acid homeostasis. The ensuing defective metabolic transition featured blunted mitochondrial lipid-derived energy production and enhanced glucose consumption, leading to perinatal cardiac dysfunction and death. Finally, GLA supplementation induced RXR-dependent expression of the mitochondrial fatty acid homeostasis signature in cardiomyocytes, both in vitro and in vivo. Thus, our study identifies the GLA-RXR axis as a key transcriptional regulatory mechanism underlying the maternal control of perinatal cardiac metabolism.

Characterization of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD)-induced cardiotoxicity in larval zebrafish (Danio rerio).

N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) is a type of p-phenylenediamine (PPD), which is widely used in the manufacture of rubber tires owing to its excellent antiozonant properties. In this study, the developmental cardiotoxicity of 6PPD was evaluated in zebrafish larvae, and the LC50 was approximately 737 µg/L for the larvae at 96 h post fertilization (hpf). In the 6PPD treatment of 100 µg/L, the accumulation concentrations of 6PPD were up to 2658 ng/g in zebrafish larvae, and 6PPD induced significant oxidative stress and cell apoptosis in the early developmental stages of zebrafish. Transcriptome analysis showed that 6PPD exposure could potentially cause cardiotoxicity in larval zebrafish by affecting the transcription of the genes related to the calcium signal pathway and cardiac muscle contraction. The genes related to calcium signaling pathway (slc8a2b, cacna1ab, cacna1da, and pln) were verified by qRT-PCR, which were significantly downregulated in larval zebrafish after exposing to 100 µg/L of 6PPD. Simultaneously, the mRNA levels of the genes related to cardiac functions (myl7, sox9, bmp10, and myh71) also respond accordingly. H&E staining and heart morphology investigation indicated that cardiac malformation occurred in zebrafish larvae exposed to 100 µg/L of 6PPD. Furthermore, the phenotypic observation of transgenic Tg (myl7: EGFP) zebrafish also confirmed that 100 µg/L of 6PPD exposure could change the distance of atria and ventricles of the heart and inhibit some key genes (cacnb3a, ATP2a1l, ryr1b) related to cardiac function in larval zebrafish. These results revealed the toxic effects of 6PPD on the cardiac system of zebrafish larvae.

Comparison of the effects of gemigliptin versus glimepiride on cardiac function in patients with type 2 diabetes uncontrolled with metformin: The gemi-heart study.

AIM: To investigate the effects of gemigliptin on cardiac function and compare the effects of gemigliptin and glimepiride in patients with type 2 diabetes (T2D). MATERIALS AND METHODS: Sixty T2D patients being treated with metformin were assigned to a gemigliptin group (50 mg daily) or a glimepiride group (2 mg daily) for 24 weeks. The preadjudicated extension period was up to 52 weeks. Glucose metabolism variables and cardiac biomarkers were measured. Echocardiography was used to evaluate cardiac functions. RESULTS: The HbA1c levels decreased significantly from 8.1% ± 0.6% to 6.8% ± 0.6% in the gemigliptin group and from 8.1% ± 0.6% to 7.0% ± 0.7% in the glimepiride group, without a between-group difference. Gemigliptin reduced insulin resistance, high sensitivity C-reactive protein and low-density lipoprotein cholesterol levels, and blood pressure, and increased adiponectin level compared with glimepiride therapy. Gemigliptin induced favourable changes in body composition. Left ventricular end-diastolic volume decreased in the gemigliptin group but increased in the glimepiride group, with a borderline between-group difference. Cardiac biomarkers did not change significantly in either group. At 52 weeks, the HbA1c levels in both groups increased slightly; 7.3% ± 0.8% in the gemigliptin group versus 7.7% ± 1.3% in the glimepiride group, without a between-group difference. CONCLUSIONS: Gemigliptin had a comparable glucose-lowering efficacy without deleterious effects on cardiac functions or on biomarkers reflective of myocardial injury or heart failure during the 24-week observation period. However, larger, longer-term studies are needed to confirm these findings.

Effects of T3 Administration on Ex Vivo Rat Hearts Subjected to Normothermic Perfusion: Therapeutic Implications in Donor Heart Preservation and Repair.

The present study investigated the effects of triiodothyronine (T3) administration in ex vivo model of rat heart normothermic perfusion. T3 is cardioprotective and has the potential to repair the injured myocardium. Isolated hearts were subjected to normothermic perfusion (NP) with Krebs-Henseleit for 4 h with vehicle (NP) or 60 nM T3 in the perfusate (NP + T3). Left ventricular end diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), perfusion pressure (PP) and percentage of change of these parameters from the baseline values were measured. Activation of stress induced kinase signaling was assessed in tissue samples. Baseline parameters were similar between groups. LVEDP was increased from the baseline by 13% (70) for NP + T3 vs. 139% (160) for NP group, p = 0.048. LVDP was reduced by 18.2% (5) for NP + T3 vs. 25.3% (19) for NP group, p = 0.01. PP was increased by 41% (19) for NP + T3 vs.91% (56) for NP group, p = 0.024. T3 increased activation of pro-survival Akt by 1.85 fold (p = 0.047) and AMPK by 2.25 fold (p = 0.01) and reduced activation of pro-apoptotic p38 MAPK by 3fold (p = 0.04) and p54 JNK by 4.0 fold (p = 0.04). Administration of T3 in normothermic perfusion had favorable effects on cardiac function and perfusion pressure and switched death to pro-survival kinase signaling.

Role of selenoprotein M knockdown in the melatonin antagonism of nickel-induced apoptosis and endoplasmic reticulum stress in mouse heart / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The aim of this study was to investigate the role of selenoprotein M (SelM) in endoplasmic reticulum stress and apoptosis in nickel-exposed mouse hearts and to explore the detoxifying effects of melatonin. At 21 d after intraperitoneal injection of nickel chloride (NiCl2) and/or melatonin into male wild-type (WT) and SelM knockout (KO) C57BL/6J mice, NiCl2 was found to induce changes in the microstructure and ultrastructure of the hearts of both WT and SelM KO mice, which were caused by oxidative stress, endoplasmic reticulum stress, and apoptosis, as evidenced by decreases in malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) activity. Changes in the messenger RNA (mRNA) and protein expression of genes related to endoplasmic reticulum stress (activating transcription factor 4 (ATF4), inositol-requiring protein 1 (IRE1), c-Jun N-terminal kinase (JNK), and C/EBP homologous protein (CHOP)) and apoptosis (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase-3, Caspase-9, and Caspase-12) were also observed. Notably, the observed damage was worse in SelM KO mice. Furthermore, melatonin alleviated the heart injury caused by NiCl2 in WT mice but could not exert a good protective effect in the heart of SelM KO mice. Overall, the findings suggested that the antioxidant capacity of SelM, as well as its modulation of endoplasmic reticulum stress and apoptosis, plays important roles in nickel-induced heart injury.

Transcriptional responses of fluxapyroxad-induced dysfunctional heart in zebrafish (Danio rerio) embryos.

Fluxapyroxad (FLU) is a succinate dehydrogenase inhibitor (SDHI) fungicide used in controlling crop diseases. Potential toxicity to aquatic organisms is not known. We exposed zebrafish to 1, 2, and 4 µM FLU for 3 days. The embryonic zebrafish showed developmental cardiac defects, including heart malformation, pericardial edema, and heart rate reduction. Compared with the controls, cardiac-specific transcription factors (nkx2.5, myh7, myl7, and myh6) exhibited dysregulated expression patterns after FLU treatment. We next used transcriptome and qRT-PCR analyses to explore the molecular mechanism of FLU cardiotoxicity. The transcriptome analysis and interaction network showed that the downregulated genes were enriched in calcium signaling pathways, adrenergic signaling in cardiomyocytes, and cardiac muscle contraction. FLU exposure repressed the cardio-related calcium signaling pathway, associated with apoptosis in the heart and other manifestations of cardiotoxicity. Thus, the findings provide valuable evidence that FLU exposure causes disruption of cardiac development in zebrafish embryos. Our findings will help to promote a better understanding of the toxicity mechanisms of FLU and act as a reference to explore the rational use and safety of FLU in agriculture.

Dipeptidyl Peptidase-4 Inhibitor Sitagliptin Exhibits Antioxidant Mechanism for Abrogation of Cyclophosphamide-Induced Cardiac Damage and Oxidative Hepatorenal Toxicity in Rats.

Cyclophosphamide (CYP) is a potent DNA-interactive anticancer drug; however, its clinical drawbacks are chiefly associated with induction of oxidative multi-organ toxicity. Sitagliptin (STG) is an antidiabetic dipeptidyl peptidase-4 inhibitor drug with antioxidant efficacy. Herein, we have explored whether STG could abrogate the CYP-induced oxidative stress-mediated cardiac and hepatorenal toxicities in male rats. Sitagliptin (20 mg/kg, o.p) was administered to rats for 5 consecutive days against organ toxicities induced by CYP (200 mg/kg, i.p) on day 5 only. CYP induced marked injuries in the liver, kidney and heart underscored by prominent increases in serum activities of ALT, AST, LDH, creatine kinase and levels of urea, uric acid and creatinine, while albumin level significantly decreased compared to normal control rats. Further, CYP considerably reduced the activities of SOD, CAT, GPx, and levels of GSH, whereas MDA level increased significantly in comparison to control rats. These biochemical alterations were confirmed by multiple histopathological lesions in the tissues. Interestingly, the STG pretreatment abrogated the biochemical and histopathological changes induced by CYP. These results provide first evidence that repurposing STG may protect the liver, kidney and heart from the oxidative deterioration associated with CYP chemotherapy.

Comparación de resultados entre soluciones con y sin formol como medios de fijación y conservación en corazones de Gallus gallus domesticus / Comparison of results between solutions with and without formaldehyde as means of fixation and conservation in Gallus gallus domesticus hearts

RESUMEN: La solución de formol es utilizada en las Escuelas de medicina como medio de fijación y conservación de cadáveres para el estudio de la Anatomía, a la que están expuestos estudiantes, técnicos y personal docente; es alergénica e irritante a las mucosas, y reconocida carcinogénica en humanos por International Agency for Research on Cancer (2006). El objetivo del presente estudio fue comparar resultados cuantitativos y cualitativos entre corazones de Gallus gallus domesticus, luego de aplicarles soluciones con y sin formol. Se formaron dos grupos al azar, a uno se le aplicó solución de formol al 10 %, y al otro solución libre de formol. Se realizaron medidas antropométricas, organolépticas, y de fotografía (Pretest, durante y Postest). Se elaboró base datos en Microsoft Excel (2019), y su procesamiento en SPSS Statistics 2017 Versión 25. Para variables cuantitativas se aplicó la prueba de Shapiro-Wilk, y t-Student pareada. Para variables cualitativas el test Alfa de Cronbach, Chi cuadrado (X2) y los correspondientes coeficientes de asociación (D de Somers y Tau b de Kendal). Los resultados obtenidos de las variables peso, largo, y altura presentaron diferencia estadística significativa (p-valor <0,05), siendo diferente para el ancho y grosor de la pared del ventrículo izquierdo. Las variables color y consistencia presentaron diferencias significativa (p-valor <0,05). El olor irritante a las mucosas estuvo presente durante todo el estudio con la solución con formol. A la inspección, ninguno de los dos grupos presento colonización - descomposición. Se concluye que, los órganos en experimentación que se les aplicó solución libre de formol, presentaron mejores resultados con respecto a los que se les aplico formol al 10 %.

SUMMARY: The formaldehyde solution is used in medical schools as a means of fixing and preserving corpses for the study of Anatomy, to which students, technicians and teaching personnel are exposed; it is allergenic and irritant to the mucosa, and recognized as a human carcinogen by the International Agency for Research on Cancer (2006). The objective of the present study was to compare quantitative and qualitative results between Gallus gallus domesticus hearts, after applying solutions with and without formaldehyde. Two groups were formed at random, to one a 10 % formaldehyde solution was applied, and to the other formaldehyde- free solution. Anthropometric, organoleptic, and photographic measurements were carried out (Pretest, during and Posttest). A database was prepared in Microsoft Excel (2019), and its processing in SPSS Statistics 2017 Version 25. For quantitative variables, the Shapiro-Wilk test and t-Student paired were applied. For qualitative variables the Cronbach's Alpha test, Chi square (X2) and the corresponding association coefficients (Somers D and Kendal's Tau b). The results obtained from the variables weight, length, and height presented a statistically significant difference (p-value <0.05), being different for the width and thickness of the left ventricular wall. The variables color and consistency showed significant differences (p-value <0.05). The irritating smell to the mucous membranes was present throughout the study with the formaldehyde solution. Upon inspection, neither group showed colonization - decomposition. It is concluded that the organs in experimentation that were applied formaldehyde-free solution presented better results compared to those that were applied 10 % formaldehyde.

Berberine exerts protective effects on cardiac senescence by regulating the Klotho/SIRT1 signaling pathway.

Berberine (BBR), an isoquinoline alkaloid, exerts protective effects on various cardiac injuries, and also extends the lifespan of individuals. However, the cardioprotective effect of BBR on cardiac senescence remains unknown. This study investigated the effects of BBR on cardiac senescence and its underlying mechanism. Senescent H9c2 cells induced by doxorubicin (DOX) and naturally aged rats were used to evaluate the protective effects of BBR on cardiac senescence. The results showed that BBR protected H9c2 cells against DOX-induced senescence. Exogenous Klotho (KL) exerts similar effects to those of BBR. BBR significantly increased in protein expression of KL, while transfection with KL-specific siRNA (siKL) inhibited the protective effect of BBR against senescence. Both BBR and exogenous KL decreased the levels of reactive oxygen species, inhibited apoptosis, and alleviated mitochondrial dysfunction in these cells; and transfection with siKL attenuated these effects of BBR. In naturally aged rats, BBR indeed protected the animals from cardiac aging, at least partially, through lowering the levels of cardiac hypertrophy markers, and increased the expression of KL in cardiac tissue. Additionally, BBR markedly reversed downregulation of sirtuin1 (SIRTI) in the aged heart. In vitro experiments revealed that BBR and exogenous KL also increased the expression of SIRT1, whereas siKL limited this effect of BBR in senescent H9c2 cell. In summary, BBR upregulated KL expression and prevented heart from cardiac senescence through anti-oxidative and anti-apoptotic effects, as well as alleviation of mitochondrial dysfunction. These effects may be mediated via regulation of the Klotho/SIRT1 signaling pathway.