Morphological Changes In Myocardium Research Articles

Alterations of Myocardial Mitochondrial Morphology and Function in a Canine Model of Premature Ventricular Contractions-Induced Cardiomyopathy.

Changes in myocardial mitochondrial morphology and function in premature ventricular contractions (PVCs)-induced cardiomyopathy (PVCCM) remain poorly studied. Here, we investigated the effects of PVCs with different coupling intervals (CIs) on myocardial mitochondrial remodelling in a canine model of PVCCM. Twenty-one beagles underwent pacemaker implantation and were randomised into the sham (n = 7), short-coupled PVCs (SCP, n = 7), and long-coupled PVCs (LCP, n = 7) groups. Right ventricular (RV) apical bigeminy was produced for 12-week to induce PVCCM in the SCP (CI, 250 ms) and LCP (CI, 350 ms) groups. Echocardiography was performed at baseline and biweekly thereafter to evaluate cardiac function. Masson's trichrome staining measured ventricular interstitial fibrosis. The ultrastructural morphology of the myocardial mitochondria was analysed using transmission electron microscopy. Mitochondrial Ca2+ concentration, reactive oxygen species (ROS) levels, adenosine triphosphate (ATP) content, membrane potential, and electron transport chain (ETC) complex activity were measured to assess myocardial mitochondrial function. Twelve-week-PVCs led to left ventricular (LV) enlargement with systolic dysfunction, disrupted mitochondrial morphology, increased mitochondrial Ca2+ concentration and ROS levels, decreased mitochondrial ATP content and membrane potential, and impaired ETC complex activity in both the SCP and LCP groups (all p < 0.01 vs the sham group). Ventricular fibrosis was observed only in canines with LCP. Worse cardiac function and more pronounced abnormalities in mitochondrial morphology and function were observed in the LCP group than to the SCP group (all p < 0.05). We demonstrated myocardial mitochondrial abnormalities in dogs with PVCCM, characterised by abnormal mitochondrial morphology, mitochondrial Ca2+ overload, oxidative stress, and impaired mitochondrial energy metabolism. Compared to SCP, long-term LCP exposure resulted in more severe mitochondrial remodelling and cardiac dysfunction in dogs.

Elevated levels of alcohol dehydrogenase aggravate ethanol-evoked cardiac remodeling and contractile anomalies through FKBP5-yap-mediated regulation of ferroptosis and ER stress

Alcohol intake provokes severe organ injuries including alcoholic cardiomyopathy with hallmarks of cardiac remodeling and contractile defects. This study examined the toxicity of facilitated ethanol metabolism in alcoholism-evoked changes in myocardial morphology and contractile function, insulin signaling and various cell death domains using cardiac-selective overexpression of alcohol dehydrogenase (ADH). WT and ADH mice were offered an alcohol liquid diet for 12 weeks prior to assessment of cardiac geometry, function, ER stress, apoptosis and ferroptosis. Alcohol intake provoked pronounced glucose intolerance, cardiac remodeling and contractile anomalies with apoptosis, ER stress, and ferroptosis, the effects were accentuated by ADH with the exception of global glucose intolerance. Hearts from alcohol ingesting mice displayed dampened insulin-stimulated phosphorylation of insulin receptor (tyr1146) and IRS-1 (tyrosine) along with elevated IRS-1 serine phosphorylation, the effect was augmented by ADH. Alcohol challenge dampened phosphorylation of Akt and GSK-3β, and increased phosphorylation of c-Jun and JNK, the effects were accentuated by ADH. Alcohol challenge promoted ER stress, FK506 binding protein 5 (FKBP5), YAP, apoptosis and ferroptosis, the effects were exaggerated by ADH. Using a short-term ethanol challenge model (3 g/kg, i.p., twice in three days), we found that inhibition of FKBP5-YAP signaling or facilitated ethanol detoxification by Alda-1 alleviated ethanol cardiotoxicity. In vitro study revealed that the ethanol metabolite acetaldehyde evoked cardiac contractile anomalies, lipid peroxidation, and apoptosis, the effects of which were mitigated by Alda-1, inhibition of ER stress, FKBP5 and YAP. These data suggest that facilitated ethanol metabolism via ADH exacerbates alcohol-evoked myocardial remodeling, functional defects, and insulin insensitivity possibly through a FKBP5-YAP-associated regulation of ER stress and ferroptosis.

Pharmacological inhibition of the cysteine protease cathepsin C improves graft function after heart transplantation in rats

BackgroundHeart transplantation (HTX) is the standard treatment for end-stage heart failure. However, reperfusion following an ischemic period can contribute to myocardial injury. Neutrophil infiltration, along with the subsequent release of tissue-degrading neutrophil elastase (NE)-related serine proteases and oxygen-derived radicals, is associated with adverse graft outcomes. The inhibition of cathepsin C (CatC) has been shown to block NE-related protease activation. We hypothesized that the CatC inhibitor BI-9740 improves graft function after HTX.MethodsIn a rat model of HTX, the recipient Lewis rats were orally administered with either a placebo (n = 12) or BI-9740 (n = 11, 20 mg/kg) once daily for 12 days. Donor hearts from untreated Lewis rats were explanted, preserved in a cardioplegic solution, and subsequently heterotopically implanted. In vivo left-ventricular (LV) graft function was assessed after 1 h of reperfusion. The proteolytic activity of neutrophil serine proteases was determined in bone marrow lysates from BI-9740-treated and control rats. Additionally, myocardial morphological changes were examined, and heart samples underwent immunohistochemistry and western blot analysis.ResultsThe NE-related proteolytic activity in bone marrow cell lysates was markedly decreased in the BI-9740-treated rats compared to those of the placebo group. Histopathological lesions, elevated CatC and myeloperoxidase-positive cell infiltration, and nitrotyrosine immunoreactivity with an increased number of poly(ADP-ribose) polymerase (PARP)-1-positive cells were lowered in the hearts of animals treated with BI-9740 compared to placebo groups. Regarding the functional parameters of the implanted graft, improvements were observed in both systolic function (LV systolic pressure 110 ± 6 vs 74 ± 6 mmHg; dP/dtmax 2782 ± 149 vs 2076 ± 167 mmHg/s, LV developed pressure, at an intraventricular volume of 200 µl, p < 0.05) and diastolic function in the hearts of BI-9740 treated animals compared with those receiving the only placebo. Furthermore, the administration of BI-9740 resulted in a shorter graft re-beating time compared to the placebo group. However, this study did not provide evidence of DNA fragmentation, the generation of both superoxide anions and hydrogen peroxide, correlating with the absence of protein alterations related to apoptosis, as evidenced by western blot in grafts after HTX.ConclusionsWe provided experimental evidence that pharmacological inhibition of CatC improves graft function following HTX in rats.

Clinical and morphological myocardial changes in patients with post-COVID-19 syndrome

Aim. To characterize the clinical manifestations and myocardial morphological changes in patients with cardiovascular complications of post-Covid syndrome.Material and methods. A total of 38 patients (Group I) with cardiac symptoms in the post-COVID-19 period underwent endomyocardial biopsy (EMB). Patients from group I were divided into 2 subgroups depending on the presence of morphologically verified myocarditis. For morphological comparison, group II was formed (41 patients without COVID-19 and with EMB performed before 2019). Group II was also divided into two subgroups with and without morphologically verified myocarditis. In addition to the analysis of clinical and paraclinical data, a histological and immunohistochemical study of myocardial tissue was carried out with anti-CD3, CD68, CD16, HLA-DR, MHC1, C1q, enterovirus VP1, SARS-CoV-2 spike protein, ACE2, Ang1, von Willebrand factor, VEGF antibodies, as well as a PCR of myocardial tissue after reverse transcription. Additionally, an immunofluorescent study of myocardial tissue was performed using antibody cocktails to SARS-CoV-2/ CD16 spike protein, SARS-CoV-2/CD68 spike protein, CD80/CD163. Statistical processing was performed using the NumPy, SciPy, Pandas and Matplotlib libraries in the Python programming language.Results. Among patients in group I, 65% had morphologically verified lymphocytic myocarditis (subgroup 1, n=29). Other 35% of patients had no signs of myocardial inflammation (subgroup 2, n=9). The comparison group (group II) included 33 patients with myocarditis (80%) and 8 patients (20%) without it. There was a pronounced expression of CD68+ macrophages in the myocardial tissue in patients with postCOVID-19 syndrome in comparison with group II, both with morphological criteria for myocarditis (p=0,014) and without it (p=0,007), mainly due to M2 macrophages. More pronounced expression of CD68+ macrophages was observed when EMB was performed at earlier stages. If SARS-CoV-2 spike protein was detected in group I on the endothelium and inflammatory infiltrate by the immunohistochemistry, PCR of myocardial tissue for SARS-CoV-2 (n=5) was performed, which did not reveal SARS-CoV-2 particles in any of the analyzed samples.Conclusion. Cardiac symptoms of post-COVID-19 syndrome are caused by myocardial remodeling, including in patients without morphologically verified myocarditis. The direct involvement of SARS-CoV-2 in the development of myocarditis in the post-acute period of COVID-19 has not been proven.

Empagliflozin improves cardiac function in rats with chronic heart failure.

The objective of this study is to examine the effect of empagliflozin on cardiac function in rats with chronic heart failure and the possible mechanism. Forty 6-week-old male SD rats were randomly divided into the control group, empagliflozin treatment group, and sham-operated group. SD rats in the control group and empagliflozin treatment group were subjected to ligation of the anterior descending coronary artery to induce an acute myocardial infarction model. SD rats in the sham-operated group were only subjected to threading of the anterior descending branch of the coronary artery without ligation. On the second day after surgery, the control group and sham operation group were given physiological saline by gavage, while the empagliflozin treatment group was given empagliflozin (30mg/kg/day) by gavage. Sixteen weeks later, cardiac function, intracellular reactive oxygen species (ROS) levels, mitochondrial membrane potential (MMP), serum brain natriuretic peptide, hypersensitive C-reactive protein (hs-CRP), iNOS expression levels, and myocardial morphological changes were observed. Compared with that in the control group, heart function in the empagliflozin-treated group was significantly improved, MMP was increased, intracellular ROS levels were decreased, and NT-proBNP and hs-CRP were significantly reduced, and HE staining showed that the cell oedema was less than that in the control group, tissue arrangement was more orderly, and iNOS expression was inhibited. Empagliflozin can improve cardiac function in rats with chronic heart failure, and the mechanism may involve inhibiting inflammation, reducing myocardial oxidative stress, and improving myocardial fibrosis.

Cardiac magnetic relaxometry versus ejection fraction in anthracycline-related cardiac changes: a systematic review and meta-analysis

PurposeThe purpose of this meta-analysis is to compare the magnitude of the changes in left ventricular ejection fraction (LVEF) and cardiac magnetic resonance (CMR) relaxometry techniques soon after the completion...

Morphological changes in myocardium of Wistar rat caused by hyperthermia

ObjectivesAim of our study was to examine whether the intensity of myocardial changes in Wistar rats exposed to hyperthermia was related to the temperature and to classify the degree and type of cardiomyocyte damage. MethodsThe study was conducted on 40 adult Wistar rats that were methodologically divided into groups, depending on water temperature exposure of 37 °C (n = 8), 41 °C (n = 16), and 44 °C (n = 16). Depending on the length of the water temperature exposure time of 41 °C and 44 °C, rats were divided into antemortem (water temperature exposure 20 min) and postmortem groups (water temperature exposure to death). Myocardial sample for pathohistological analysis was taken after the death of the animal. Microscopic examination with semiquantitative analysis of myocardial changes was performed. ResultsPathohistological analysis determined the normal myocardial structure of control group (animals exposed to water temperature of 37 °C, with mild, degenerative changes in cardiomyocytes nonspecific for hypertemia in rats exposed to water temperatures of 41 °C and 44 °C. Type of myocardial changes in rats in groups exposed to water temperatures of 41 °C and 44 °C was classified as minimal and multifocal degenerative changes (45.25 %; 51.6 %, respectively), which was significantly more pronounced compared to the myocardial control group (p < 0.0005). ConclusionThe dynamics of the development of morphological changes in cardiomyocytes did not show high significance, which is attributed to the short manifestation time, and does not make it impossible to visualize changes at the subcellular level in tissuestained by hematoxylin-eosin method.

Effects of the interaction of Notch and TLR4 pathways on inflammation and heart function in septic heart.

We investigated the role of the interaction between the Notch and Toll-like receptor 4 (TLR4) pathways in septic myocardial injury. The sepsis model was induced in rats with lipopolysaccharide (LPS). Rats were divided into control, LPS, LPS + TAK242 ((6R)-6-[N-(2-chloro-4-fluorophenyl)sulfamoyl]cyclohex-1-ene-1-carboxylate) and LPS + DAPT (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-s-phenylglycinetbutylester) groups. Heart function was evaluated with a Cardiac Doppler ultrasound. Myocardial morphological changes were detected by hematoxylin-eosin staining (H&E). Apoptosis was assessed by a TUNEL assay. The mRNA and protein levels were detected with real-time PCR, Western blot, and immunohistochemistry analysis. We found that heart function in the LPS + TAK242 group was significantly improved, but not in the LPS + DAPT group. LPS + TAK242 had a lower level of degeneration and necrosis of cardiomyocytes and inflammatory cell infiltration, as well as lower apoptosis and caspase-3 expression than the LPS group. Compared with the LPS group, the inflammatory cell infiltration was reduced in the LPS + DAPT group, while the degeneration and necrosis of cardiomyocytes were not obviously improved. Additionally, the expression levels of tumor necrosis factor-α and Interleukin-6, the protein contents of Notch intracellular domain and Hes1, and the P65 nuclear factor kappa-B (NF-κB) to P-P65 NF-κB ratio in LPS + TAK242 group and LPS + DAPT group were significantly lower than those in LPS group. Conclusively, the interaction between TLR4 and Notch signaling pathways enhances the inflammatory response in the septic heart by activating NF-κB. Blocking the TLR4 pathway with TAK242 can improve heart dysfunction and myocardial damage in sepsis, while blocking the Notch pathway with DAPT cannot effectively prevent heart dysfunction and myocardial damage in sepsis.

Delivery of astragalus polysaccharide by ultrasound microbubbles attenuate doxorubicin-induced cardiomyopathy in rodent animals

ABSTRACT The aim of this study was to investigate the cardioprotective effects and probable mechanism of ultrasound-targeted microbubble destruction (UTMD) combined with astragalus polysaccharide (APS) on diabetic cardiomyopathy (DCM) model rats. The DCM rats with diabetes and cardiomyopathy were induced via chronic treatment of doxorubicin and then randomly divided into the (1) DCM model group; (2) APS microbubble group; (3) UTMDgroup; and (4) APS microbubbles combined with UTMD group. After 4-week intervention, the fasting blood glucose levels, body weight, %HbA1c level and glucose tolerance of DCM rats received combination therapy were significantly improved as compared with those of UTMD or saline-treated ones. Moreover, the heart/body weight ratio, and myocardial contractility were all improved after receiving combination therapy groups compared with others. In addition, significantly upregulated activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) as well as significantly downregulated malondialdehyde (MDA) levels were all observed in the ones received combined treatment compared to others. Furthermore, the lipid accumulation and the expression levels of inflammatory factors were all significantly down-regulated in those ones received combination therapy compared with others (all P < 0.05). Further pathological analysis demonstrated that combination therapy effectively ameliorated fibrosis and myocardial morphological changes of DCM rats via activating the upregulation of AMPK and PPAR-γ signaling pathway, and inhibiting NF-κB activity in myocardial tissues of DCM rats. In conclusion, APS microbubbles combined with UTMD effectively protect the myocardial injury of DCM rats via activating AMPK signaling pathway to alleviate inflammation response, fibrosis and oxidative stress in myocardial tissues.

Protective effect of glucagon-like peptide-1 mediated by ultrasound microbubbles on myocardial injury in rats with diabetic cardiomyopathy

ABSTRACT Current study was performed to investigate the therapeutic effects of UTMD combined with Semaglutide, a GLP-1 R agonist, on DCM in GK rats. After 6-week intervention, all rats were examined by conventional echocardiography, and the indicators of papillary muscle horizontal wall were measured. At the end of experiment, the DCM rats were sacrificed, and then blood samples were taken to detect blood lipids and the activities of oxidative stress-related factors in myocardial tissues. Moreover, the myocardial tissues were also taken to observe histomorphological changes and myocardial fibrosis via H&E and Masson staining, respectively. Furthermore, the mRNA and protein levels of PPAR-γ and NF-κB in myocardial tissues were detected. As a result, the glycometabolism and the cardiac functions of DCM rats received combination therapy of GLP-1 R agonist and UTMD were improved. Significantly increased SOD and GSH-Px as well as significantly decreased MDA levels were also observed in rats of combined group compared with others. In addition, both mRNA and protein levels of PPAR-γ and NF-κB were significantly lower than those of the model control ones and Semaglutide microbubbles alone (all P < 0.001). Further pathological histology analysis demonstrated that combination therapy effectively ameliorated fibrosis and myocardial morphological changes of DCM rats. In summary, UTMD combined with Semaglutide can effectively protect cardiac function in rats with DCM by significantly alleviating myocardial fibrosis and oxidative stress. Abbreviations Ultrasound-targeted microbubble destruction, UTMD; glucagon-like peptide-1 receptor, GLP-1R; diabetic cardiomyopathy, DCM; Goto-Kakizaki, GK; velocity vector imaging, VVI; left ventricular end-diastolic diameter LVIDd; left ventricular end-systolic diameter, LvIDs; left ventricular end-diastolic pressure, LVEDP; fractional shortening, LVFs; left ventricular ejection fraction, LVEF; mean peak radial velocity, Vs; radial strain, Sr; radial strain rate, SRr; superoxide dismutase, SOD; malondialdehyde, MDA; glutathione peroxidase, GSH-Px; peroxisome proliferator-activated receptor-γ, PPAR-γ; nuclear transcription factor κB, NF-κB; insulin resistance, IR; total cholesterol, TC; total triglycerides, TG; creatine kinase, CK; lactate dehydrogenase, LDH; cardiac troponin I, cTnI; collagen volume fraction, CVF; Hematoxylin eosin, H&E.

Lupeol Alleviates Myocardial Ischemia-Reperfusion Injury in Rats by Regulating NF-[Formula: see text]B and Nrf2 Pathways.

Cardiovascular disease is a global health problem. Previous studies revealed that it involves acute myocardial infarction and ischemia-reperfusion (I/R) injury. The mechanism of myocardial I/R injury is complex. But recognizing its mechanisms will bring important clinical significance. Lupeol is widely found in Chinese medicinal herbs and has been shown to have a variety of bio-activities. However, the pharmacological action of lupeol in the progress of myocardial ischemia-reperfusion injury (MIRI) is unclear. This study used a rat myocardial I/R model and the morphological changes in myocardium were determined by 2,3,5-triphenyltetrazolium chloride (TTC) staining. The expression levels of IL-10, IL-1[Formula: see text], TNF-[Formula: see text], and IL-6 were assessed by quantitative real-time PCR (qRT-PCR) and ELISA. The expression levels of MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) level and inflammatory cytokines were quantified using ELISA. The cellular apoptotic rate was determined by TUNEL staining. The findings showed that lupeol significantly decreased myocardial infarction after I/R and ameliorated I/R-induced myocardial inflammation, apoptosis, and oxidative stress. Furthermore, our results suggested that lupeol protected against MIRI-induced myocardial infarction through modulation of NF-[Formula: see text]B and Nrf2 signaling pathways. In summary, this study first clarified the cardioprotective effects of lupeol against I/R-induced myocardial infarction in rats, which could be due to its anti-oxidant, anti-inflammatory, and anti-apoptotic activities. Our study also highlighted a mechanism of NF-[Formula: see text]B and Nrf2 signaling, through which lupeol could be a promising agent in protecting against I/R-induced myocardial infarction.

Teratogenic effect of alcohol on the myocardium of laboratory animals at the stages of prenatal ontogenesis (literature review)

Background. To date, close attention is paid to the problems of formation and development of the myocardium in general and in particular its structural components. This phenomenon is associated with an increase in cardiovascular malformations in both adults and infants. These defects can be caused by genetic factors, as well as various teratogenic substances. One such substance is alcohol. Despite the risks, many women still drink alcohol during pregnancy. The main problem is that almost half of pregnancies are unplanned, so a woman may continue to consume alcohol for several weeks before learning about her condition. Especially in young women, fertilization can occur in a state of intoxication. In addition, under the influence of ethanol, cardiac function may be impaired in the absence of structural abnormalities. Chronic alcohol intoxication causes changes in the myocardium at all levels of its structural organization. First of all, teratogenic changes caused by the action of ethanol affect the development of cardiomyocytes in the process of embryogenesis, which contributes to the underdevelopment of the structure or function of heart cells. Although the effect of maternal alcohol consumption on the fetus has been studied for decades, there are still conflicting conclusions about the severity of myocardial morphological changes depending on the time, frequency and duration of alcohol consumption. Objective: to conduct a retrospective analysis of literature sources devoted to the study of adverse effects on the fetus caused by alcohol. Methods. The paper conducted a retrospective analysis of literature references and formed an understanding of the changes in the structure of the myocardium caused by teratogenic effects of alcohol. Results and conclusion. Analysis of literature sources showed a high level of adverse effects observed in offspring born to alcoholic mothers. Detrimental effects of alcohol cause changes in the myocardium at all levels of structural organization, including its ultrastructure. It was studied that prenatal exposure to ethanol induces significant changes in relative heart weight, left ventricular wall thickness and cardiomyocyte size. Exposure to high concentrations of alcohol in experimental animals during gestation can lead to congenital heart defects, such as atrial, ventricular, and septal defects. The main manifestation of the prenatal effect of alcohol after birth is the fetal alcohol syndrome, which combines various degrees of deviation in the development of the child.

Exercise-Induced Cardiac Fatigue in Soldiers Assessed by Echocardiography.

Background: Echocardiographic signs of exercise-induced cardiac fatigue (EICF) have been described after strenuous endurance exercise. Nevertheless, few data are available on the effects of repeated strenuous exercise, especially when associated with other constraints as sleep deprivation or mental stress which occur during military selection boot camps. Furthermore, we aimed to study the influence of experience and training level on potential EICF signs.Methods: Two groups of trained soldiers were included, elite soldiers from the French Navy Special Forces (elite; n = 20) and non-elite officer cadets from a French military academy (non-elite; n = 38). All underwent echocardiography before and immediately after exposure to several days of uninterrupted intense exercise during their selection boot camps. Changes in myocardial morphology and function of the 4 cardiac chambers were assessed.Results: Exercise-induced decrease in right and left atrial and ventricular functions were demonstrated with 2D-strain parameters in both groups. Indeed, both atrial reservoir strain, RV and LV longitudinal strain and LV global constructive work were altered. Increase in LV mechanical dispersion assessed by 2D-strain and alteration of conventional parameters of diastolic function (increase in E/e' and decrease in e') were solely observed in the non-elite group. Conventional parameters of LV and RV systolic function (LVEF, RVFAC, TAPSE, s mitral, and tricuspid waves) were not modified.Conclusions: Alterations of myocardial functions are observed in soldiers after uninterrupted prolonged intense exercise performed during selection boot camps. These alterations occur both in elite and non-elite soldiers. 2D-strain is more sensitive to detect EICF than conventional echocardiographic parameters.

Myocardial morphological changes and pulmonary vein catheter ablation efficacy in patients with atrial fibrillation

Aim. To study the association between morphological changes and comorbidities and atrial fibrillation (AF) catheter ablation efficacy, and to evaluate morphological predictors of AF recurrence in patients with durable pulmonary vein isolation (PVI) after catheter intervention.Material and methods. Fifty-four patients with paroxysmal/persistent AF without severe structural heart disease were enrolled in this study who underwent primary pulmonary vein cryoballoon ablation (CBA) with simultaneous implantation of an electrocardiogram loop recorder (Medtronic Reveal XT) and interatrial/interventricular septum biopsy. The follow-up duration was 12 months with scheduled 3, 6 and 12 month visits. Patients with recurrent AF were referred for redo procedure, where the PVI durability was assessed. The follow-up duration after the second procedure was also 12 months. The patients were divided into two groups: patients without recurrent AF and patients with recurrent AF after two catheter interventions.Results. In interventricular septum biopsy samples we found the morphological criteria of myocarditis in 70% of the patients (n=34). Individual morphological changes were detected in all patients. The most common types were cardiomyocyte hypertrophy — 98,1% (n= 52), overcrossing of cardiomyocytes — 77,4% (n=41) and lymphohistiocytic infiltration of the interstitium by more than 14 cells — 75,5% (n=40). Patients with persistent AF were significantly more likely to have endothelial cell swelling (55% vs 45%, p=0,022). Interstitial tissue edema was the only morphological parameter significantly associated with AF recurrence (p=0,03).Conclusion. In patients with AF and no structural heart disease who underwent drug-resistant AF cryoballoon ablation, morphological changes in the myocardium of the atria and ventricles are detected in 100% of cases. The predominant biopsy diagnosis is myocarditis. Morphological signs of the inflammatory process activity, as interstitial tissue edema are associated with the high incidence of non-venous AF. Further preoperative evaluation is needed to identify patients with non-venous atrial fibrillation, which will increase the effectiveness of interventional approach.

FAM134B-mediated endoplasmic reticulum autophagy protects against sepsis myocardial injury in mice.

Reticulophagy regulator 1 (RETEG1, also known as FAM134B) plays a crucial role in endoplasmic reticulum autophagy. We aimed to explore the effect of FAM134B-mediated endoplasmic reticulum autophagy in sepsis myocardial injury in mice. Sepsis myocardial injury mice were established via cecal ligation and puncture procedures. The expression of FAM134B and LC3-II/I was determined using immunohistochemistry. Myocardial tissue morphological changes and apoptosis were examined using hematoxylin and eosin (H&E) staining and TUNEL analysis. The effects of FAM134B knockdown or overexpression on mice with sepsis myocardial injury were also studied. The levels of TNF-α, IL-6, IL-8, and IL-10 were evaluated using enzyme-linked immunosorbent assay (ELISA). Autophagy- and apoptosis-related protein expression was detected using western blotting. The effect of FAM134B on Lipopolysaccharide (LPS) -induced cardiomyocytes was also studied. The expression of FAM134B and LC3-II/I increased in sepsis mice and lipopolysaccharide (LPS)-treated cardiomyocytes. 3-Methyladenine (3-MA) significantly inhibited FAM134B and LC3-II/I expression and promoted myocardial injury, inflammation response, and cardiomyocyte apoptosis. The overexpression of FAM134B could minimize myocardial injury, inflammation, and apoptosis, whereas FAM134B knockdown showed opposite effects. FAM134B-mediated endoplasmic reticulum autophagy had a protective effect on sepsis myocardial injury in mice by reducing inflammation and tissue apoptosis, which may provide new insights for sepsis myocardial injury therapies.

Chinese medicine GeGen-DanShen extract protects from myocardial ischemic injury through promoting angiogenesis via up-regulation of VEGF/VEGFR2 signaling pathway

Headings ethnopharmacological relevanceCoronary heart disease (CHD) usually refers to myocardial ischemia or myocardial necrosis caused by coronary artery stenosis. GeGen and DanShen (GD) are popular Chinese herbs for the treatment of angina pectoris and myocardial infarction (MI). This sentence needs to be a separate paragraph.Aim of the study: This study was to investigate the role of GD extract in promoting ischemic myocardial angiogenesis, and to explore its signaling mechanism, so as to provide a more reliable scientific basis for the clinical treatment of ischemic cardiovascular disease. Materials and methodsGD extract was initially analyzed by HPLC-Q-TOF MS. In vitro, migration assay and tube formation assay were subsequently used to detect the angiogenesis activity of GD extract in human umbilical vein endothelial cells (HUVECs). Following the in vitro study, an MI rat model was established by ligating the left anterior descending coronary artery (LAD), immediately followed by a 4-week daily GD extract treatment by intragastric administration. After the animal sacrifice, hematoxylin-eosin (HE) staining was conducted to observe the pathological changes of the infarct margin. Besides, the MI area was measured by 2,3,5-triphenyltetrazoliumchloride (TTC) staining. The microvascular density (MVD) was also quantified through CD31 immunohistochemistry. Moreover, the levels of VEGF, TXB2 and 6-keto-PGF1α in serum were detected by enzyme-linked immunosorbent assay. The expression of VEGFR2 and ERK were detected by immunohistochemistry as well. ResultsIn vitro study, GD extract was found to induce significant angiogenesis in HUVECs. In vivo, smaller infarct size was found in treatment groups than that of the model group, and the protein expression of VEGFR2 as well as ERK in the marginal zone of MI in treatment groups were significantly increased. The morphological changes of myocardium were observed with a significant growth in the number of new blood vessels. Regarding the effect of GD extract, the serum levels of CK, LDH and TXB2 were consequently reduced, whereas the levels of VEGF, 6-keto-PGF1α were significantly increased. ConclusionsBased on the findings of this study, GD extract had a protective effect against MI in rats. The possible mechanism is to promote angiogenesis by regulating the VEGF/VEGFR2 signaling pathway after MI occurrence.

Mechanism of stress heart damage in the animals of different sensitivity to hypoxia

Hypoxia and resistance to it is the main in today data sitiuayion in the world.The aim of the study was to determine level of myocardium damage and corresponding of it with cytokines level in high- and low-resistance to hypoxic hypoxia rats (HR, LR) in different models of immobilization stress.Material and methods of investigation. The experiments were performed on 144 outbred HR and LR aged 5.5-6 months, dividing into 3 groups – control and 2 with different model of immobilizing stress. It was determined morphological changes of myocardium and concentration of interleukins 1beta, 2, 4, 6, 10 (IL-1beta, IL-2, IL-4, IL-6, IL-10), tumor necrosis factor alpha (TNF-alpha) in the blood serum.Results. The morphological investigation showed the bigger damage effect in LR animal, than in HR rats. Damage effects were higher in males, than in females. The stress repeating every 72 hours (stress 2) had higher damage in myocardium, than stress repeating every 24 hours (stress 1). We corresponds the results with cytokines level. High congenital resistance to hypoxia is associated with an increased content of anti-inflammatory cytokines (in males IL-4, in females IL-10). Intact males, compared with females, have a higher production of pro-inflammatory cytokines (IL-6, TNF-alpha).At stress1 inHR males, compared with HR females, were lower contents of IL-10, higher level of IL-1beta, IL-4, IL-6, TNF-alpha. At stress1 inLR males, compared with LR females, were lower contends of IL-10, IL-2. The morphological changes were more in males, that’s why higher level of anti-inflammatory cytokines IL-10 really has protection in HR and LR females’ animals. At stress2 inHR male, compared with HR female, were lower contents of IL-1beta and IL-10, higher IL-2 and IL-6. At stress2 inLR males, compared with LR females, were higher level of IL-10, IL-6, lower contents of IL-2, IL-4. The morphological changes were more in males, that’s why pro-inflammatory cytokines IL-6 really take place in damage of myocardium in males with different resistance animals.Conclusion. High congenital resistance to hypoxia is associated with smaller destroying of the myocardium layer in immobilizing stress, which correspond with increased content of anti-inflammatory cytokines IL-4 and, IL-10. Higher damage of myocardium in immobilizing stress correspond with higher production of pro-inflammatory cytokines (IL-6, TNF-alpha).

Dexmedetomidine pretreatment protects the heart against apoptosis in ischemia/reperfusion injury in diabetic rats by activating PI3K/Akt signaling in vivo and in vitro

Dexmedetomidine (DEX) exerts cardioprotection against ischemia/reperfusion injury. However, the precise mechanisms underlying this cardioprotective effect in diabetic rats are still not fully understood. The aim of the present study was to investigate the cardioprotective mechanism of DEX pretreatment on myocardial ischemia/reperfusion (I/R) injury in diabetic rats. A total of 25 streptozotocin-induced diabetic rats were equally randomized into five groups: i) Sham, ii) DEX (100 μg/kg); iii) myocardial I/R; iv) myocardial I/R+DEX (10 μg/kg); and v) myocardial I/R+DEX (100 μg/kg) groups. Primary cardiomyocytes were cultured in DEX for 1 h, and then oxygen and glucose deprivation (OGD)/R for 36 h. These results showed that pretreatment with DEX significantly decreased the I/R-induced size of the myocardial infarction, structural damage, morphological changes and apoptosis in myocardial cells, as well as levels of creatinine kinase, malondialdehyde and cardiac troponin I, and increased the I/R-induced superoxide dismutase activity in vivo and in vitro. Furthermore, immunohistochemical staining and western blot analysis revealed that DEX pretreatment significantly increased the I/R-induced expression levels of B-cell lymphoma 2 (Bcl-2), phosphorylated phosphoinositide 3-kinase (pPI3K) and pAkt, and significantly decreased those of pBcl-2 associated agonist of cell death, Bcl-2-associated X protein and cleaved caspase 3 in vivo and in vitro. In addition, all of these cardioprotective effects of DEX were reversed by yohimbine and LY294002 pretreatment. These results suggested that DEX pretreatment may activate the PI3K/Akt signaling pathway in an α2 adrenoceptor-dependent manner. DEX pretreatment may exert cardioprotective effects against myocardial ischemia/reperfusion injury in diabetic rats through the I/R-induced inhibition of cell apoptosis by activating the PI3K/Akt signaling pathway.

Semaglutide attenuates excessive exercise-induced myocardial injury through inhibiting oxidative stress and inflammation in rats

AimsTo investigate the protective effects and mechanism of semaglutide on exercise-induced myocardial injury. Main methodsEffects of semaglutide on lipopolysaccharide (LPS)-induced oxidative stress injuries and inflammatory response were assessed in H9c2 cell via MTT assay and Western blot. Quiet control group, over training group and three doses of semaglutide treated overtraining groups were subjected to the swimming training with increasing load for consecutive 10 weeks. Immediately after the last training, the body weight, myocardial morphological changes, injury markers and inflammatory response related proteins of the model rats were analyzed. Key findingsSemaglutide at three concentrations in LPS treated H9c2 cells significantly increased the survival rate and inhibited the apoptosis of cardiomyocytes. Moreover, semaglutide activated AMPK pathway, improve autophagy and inhibited reactive oxygen species production in LPS treated H9C2 cells. In vivo results further revealed that chronic treatment of semaglutide induced significant increase in myocardial injury markers. The pathological histology analysis results showed that semaglutide ameliorated myocardial morphological changes, reduced area of lipid accumulation and significantly decreased the expression levels of NF-κB, TNF-α and IL-1β. SignificanceSemaglutide exert the protective effects on exercise-induced cardiomyopathy by activating AMPK pathway, increasing autophagy, reducing the production of ROS and inflammation-related proteins.

Xiao-Qing-Long-Tang Maintains Cardiac Function during Heart Failure with Reduced Ejection Fraction in Salt-Sensitive Rats by Regulating the Imbalance of Cardiac Sympathetic Innervation.

Objective The anatomical and functional imbalances of sympathetic nerves are associated with cardiovascular disease progression. Xiao-Qing-Long-Tang (XQLT), an ancient Chinese herbal formula, has been used to treat cardiovascular diseases in eastern Asia for thousands of years. We determined the effect of XQLT in maintaining cardiac function during heart failure with reduced ejection fraction (HFrEF) with respect to its neurobiological effects in salt-sensitive rats. Methods Dahl salt-sensitive (DS) rats were fed a high-salt diet to establish an HFrEF model and were divided into model (DS, administered normal saline) and XQL groups (administrated XQLT) randomly, with SS-13BN rats being used as the control. The bodyweight and blood pressure of rats were observed regularly. Electrocardiogram, echocardiography, and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) were determined to assess cardiac function. The sympathetic tune and myocardial morphological changes were evaluated. Western blot and qRT-PCR were used to assay the expression of the nerve growth factor (NGF) and leukemia inhibitory factor (LIF). Tyrosine hydroxylase (TH), choline acetyltransferase (CHAT), and growth-associated protein 43 (GAP43) were assayed to confirm sympathetic remodeling. The micromorphological changes in cardiac sympathetic nerve endings were observed by transmission electron microscopy. Results Four weeks after XQLT treatment, cardiac function and bodyweight were higher and blood pressure was lower than that of the DS group. Myocardial noradrenaline (NA) increased, while the plasma NA level decreased significantly. The morphology demonstrated that XQLT significantly alleviated myocardial damage. XQLT decreased the expression of LIF, increased the expression of NGF, enhanced the TH+/GAP43+ and TH+/CHAT + positive nerve fiber density, and improved the TH and GAP43 protein expression, but had no effect on CHAT. Moreover, XQLT improved the micromorphology of sympathetic nerve endings in the myocardium. Conclusion XQLT maintains cardiac function during HFrEF in salt-sensitive rats, in part, by regulating the imbalance of cardiac sympathetic innervation.