Markers Of Myocardial Injury Research Articles

Quercetin inhibits necroptosis in cardiomyocytes after ischemia-reperfusion via DNA-PKcs-SIRT5-orchestrated mitochondrial quality control.

We investigated the mechanism by which quercetin preserves mitochondrial quality control (MQC) in cardiomyocytes subjected to ischemia-reperfusion stress. An enzyme-linked immunosorbent assay was employed in the in vivo experiments to assess myocardial injury markers, measure the transcript levels of SIRT5/DNAPK-cs/MLKL during various time intervals of ischemia-reperfusion, and observe structural changes in cardiomyocytes using transmission electron microscopy. In in vitro investigations, adenovirus transfection was employed to establish a gene-modified model of DNA-PKcs, and primary cardiomyocytes were obtained from a mouse model with modified SIRT5 gene. Reverse transcription polymerase chain reaction, laser confocal microscopy, immunofluorescence localization, JC-1 fluorescence assay, Seahorse energy analysis, and various other assays were applied to corroborate the regulatory influence of quercetin on the MQC network in cardiomyocytes after ischemia-reperfusion. In vitro experiments demonstrated that ischemia-reperfusion injury caused changes in the structure of the myocardium. It was seen that quercetin had a beneficial effect on the myocardial tissue, providing protection. As the ischemia-reperfusion process continued, the levels of DNA-PKcs/SIRT5/MLKL transcripts were also found to change. In vitro investigations revealed that quercetin mitigated cardiomyocyte injury caused by mitochondrial oxidative stress through DNA-PKcs, and regulated mitophagy and mitochondrial kinetics to sustain optimal mitochondrial energy metabolism levels. Quercetin, through SIRT5 desuccinylation, modulated the stability of DNA-PKcs, and together they regulated the "mitophagy-unfolded protein response." This preserved the integrity of mitochondrial membrane and genome, mitochondrial dynamics, and mitochondrial energy metabolism. Quercetin may operate synergistically to oversee the regulation of mitophagy and the unfolded protein response through DNA-PKcs-SIRT5 interaction.

Characteristics and changes of cardiac injury with age in children of Duchenne muscular dystrophy: a prospective cohort study

Objective: To explore the characteristics and changes of cardiac injury with age in Duchenne muscular dystrophy (DMD) and its clinical significance. Methods: A prospective cohort study was conducted. The 215 patients diagnosed with DMD in West China Second Hospital from January 2019 to November 2022 and aged from 6 to 18 years were enrolled. Their clinical data, myocardial injury markers, routine electrocardiogram, cardiac magnetic resonance (CMR) and echocardiography were collected. The patients were divided into five age groups: 6-<8, 8-<10, 10-<12, 12-<14 and 14-18 years of age, and matched with healthy boys respectively. Independent sample t test or Mann-Whitney U test was used to compare the clinical data and CMR indexes between DMD patients and controls in all age subgroups, and to compare the value of left ventricular ejection fraction (LVEF) measured by echocardiography and CMR in each subgroup of DMD patitents. Pearson correlation analysis or Spearman correlation analysis was used to explore the relation between the CMR indexes and age in DMD patients. Results: A total of 215 patients with DMD (all male) and 122 healthy boys were included in the study. There were 75 DMD patients and 23 controls in 6-<8 years of age group, 77 DMD and 28 controls in 8-<10 years of age group, 39 DMD and 23 controls in 10-<12 years of age group, 10 DMD and 31 controls in the 12-<14 years of age group, and 14 DMD and 17 controls in 14-18 years of age group. In the DMD patients, the older the age, the lower the levels of creatine kinase (CK) and creatine kinase isoenzyme (CK-MB). In the 6-<8 years of age group, the CK level was 10 760 (7 800, 15 757) U/L, while in the group of 14-18 years of age, it was 2 369 (1 480, 6 944) U/L. As for CK-MB, it was (189±17) μg/L in the 6-<8 years of age group and (62±16) μg/L in the 14-18 years of age group. Cardiac troponin I remained unchanged in <12 years of age groups, but significantly increased in 12-<14 years of age group, reaching the highest value of 0.112 (0.006, 0.085) μg/L. In the DMD patients, the older the age, the higher the proportion of abnormal electrocardiogram (ECG). In the 6-<8 years of age group, the proportion is 29.3% (22/75), while in the 14-18 years of age group, it was 10/14. Correlation analysis showed that the left ventricular end-diastolic volume index was positively related with age (r=0.18, P=0.015), and the left ventricular stroke volume index and cardiac output index were negatively related with age (r=-0.34 and -0.31, respectively, both P<0.001). In the DMD patients, the older the age, the lower LVEF, with the LVEF decreasing to (49.3±3.1)% in the 14-18 years of age group. The LVEF of DMD cases was significantly lower than that of controls in the age subgroups of 8-<10, 10-<12, 12-<14 and 14-18 years of age groups ((57.9±5.2) % vs. (63.6±0.8)%, 60.7% (55.9%, 61.9%) vs. 63.7% (60.2%, 66.0%), 57.1% (51.8%, 63.4%) vs. 62.1 % (59.5%, 64.5)%, (49.3±3.1) % vs. (61.6±1.3)%, respectively; all P<0.01). In the DMD patients, the older the age, the higher the proportion of positive late gadolinium enhancement (LGE). In the 6-<8 years of age group, it was 22% (11/51), in the 12-<14 years of age group, it was 13/14, and in the 14-18 years of age group, all DMD showed positive LGE. The value of LVEF of DMD cases measured by echocardiography was significantly higher than that measured by CMR in 6-<8 years of age group and 8-<10 years of age group (63.2% (60.1%, 66.4%) vs. 59.1 % (55.4%, 62.9%), and (62.8±5.2) % vs. (57.9±5.2)%, all P<0.001). Conclusion: DMD patients develop cardiac injury in the early stage of the disease, and the incidence of cardiac damage gradually increases with both age and the progression of disease.

Biomedical Applications of Wavelet Transform Algorithm on Deep Learning Ultrasonic Image Optimization as a Prognosis Model for Acute Myocarditis

We aimed to investigate the biomedical methods of wavelet transform algorithm on ultrasonic image denoising algorithm and the risk factors for the adverse prognostic events of patients with myocarditis and analyse its correlation with free triiodothyronine (FT3) level. A retrospective study was performed to include 68 patients diagnosed with acute myocarditis (AM). The included patients were enrolled into adverse event (AE) group (n = 7) and non-adverse event (NAE) group (n = 61). The clinical data, laboratory examination indicators, echocardiographic parameters, and thyroid functions between the patients in the two groups at admission were compared. Besides, wavelet transform (WT) algorithm was employed to process ultrasonic images containing noises. Univariate and multivariate analysis were performed using Logistic regression model. It was demonstrated that peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) (35.279, 0.847) of wavelet transform algorithm were higher than those of denoising convolutional neural network (DnCNN) algorithm (30.673, 0.582) and Red-Net algorithm (28.489, 0.638). In the AE group, the QRS interval was longer ([102 (93, 135) ms] versus [86 (79, 102) ms]), the proportion of prolonged QRS period was higher (28.57%, 9.83%), and the creatine kinase isoenzyme, a marker of myocardial injury, was higher [32.87 (13.64, 78.62) U/L] versus 12.02 (9.89, 27.65) U/L], and the level of FT3 was lower [1.87 (1.23, 2.36) pg/mL versus 2.83 (1.83, 3.45) pg/mL] compared to the NAE group. The left ventricular ejection fraction (LVEF) in the adverse event group was lower than that in the non-adverse event group [45.78 (36.18, 54.32) % versus 63.72 (54.82, 64.68)]. Multivariate Logistic regression analysis showed that the risk factors for adverse events in patients with acute myocarditis included QRS interval &gt; 120 ms (OR = 1.021), creatine kinase isoenzyme &gt; 24 U/L (OR = 1.024), FT3 (OR = 0.067), and LVEF &lt; 50% (OR = 0.973). This work confirmed that the wavelet transform algorithm can optimize the image quality of echocardiography, improve the clarity, and provide a feasible idea for improving the prognosis of patients with acute myocarditis.

Endothelial dysfunction and disease severity in COVID-19: Insights from circulating Tang cell counts as a potential biomarker

Background and aimEndothelial dysfunction is a common risk factor of severe COVID-19. Angiogenic T cells (Tang cells) play a critical role in repairing endothelial injury; however, their changes and potential roles in COVID-19 remain unclear. We aimed to assess Tang cell counts in patients with COVID-19 and evaluate their association with disease severity and prognosis. MethodsCirculating Tang cell populations in patients with COVID-19 and healthy controls were quantified using flow cytometry. Demographic and routine laboratory data were recorded. ResultsThe Tang cell count decreased significantly with increasing disease severity and were lowest in fatal cases. Additionally, the Tang cell count was significantly decreased in patients with comorbid cardiovascular disease or hypertension. Tang cell counts were negatively correlated with inflammatory markers, kidney and myocardial injury markers, coagulation dysfunction indicators, and viral load and positively correlated with oxidative stress markers, nutritional markers, and lymphocytes. Receiver operating characteristic curves confirmed that Tang cell count could serve as a potential biomarker for predicting disease severity and patient mortality. ConclusionsCirculating Tang cell count is significantly reduced in patients with COVID-19 and is correlated with disease severity and prognosis. The Tang cell count is an important potential biomarker for COVID-19 clinical management. Additionally, these findings provide insight into the pathological features of COVID-19 endothelial injury and provide new directions for treatment.

Evidence map of clinical research on Chinese patent medicines for post-acute myocardial infarction heart failure

An evidence map was established to comprehensively sort out the clinical research in the treatment of post-acute myocardial infarction heart failure(P-AMI-HF) with Chinese patent medicines, so as to reveal the distribution of evidence in this field. CNKI, Wanfang, VIP, SinoMed, PubMed, Cochrane Library, and EMbase were searched for the randomized controlled trial(RCT), systematic reviews/Meta-analysis, and guidelines/consensus in this field. The evidence was analyzed and displayed in the form of a combination of text, charts, bubble charts, and bar charts, and the quality of RCT, systematic reviews/Meta-analysis, and guidelines/consensus were evaluated by RoB 1.0, AMSTAR2, and AGREE Ⅱ, respectively. A total of 163 RCTs, 4 systematic reviews/Meta-analysis, 1 network Meta-analysis, 2 observational studies, and 5 guidelines/consensus were included. In recent years, the total number of publications in this field has shown an upward trend. There were a variety of Chinese patent medicines in the treatment of P-AMI-HF, among which Shenfu Injection received the most attention. The clinical RCT and systematic reviews/Meta-analysis generally had poor quality, and the RCT mostly had a small size, a single center, and a short cycle. The outcome indicators mainly included cardiac function indicators, myocardial injury markers, total response rate, hemodynamic indicators, and safety indicators, while the characteristic efficacy indicators of TCM received insufficient attention. The development processes of some guidelines/consensus lack standardization, which compromised their authority and rationality. Chinese patent medicines have advantages in the treatment of P-AMI-HF, while there are also problems, which remain to be solved by more high-quality evidence. That is, more large-sample and multi-center clinical studies should be carried out in the future, and the formulation process of relevant systematic reviews/Meta-analysis and guideline/consensus should be standardized and the quality of evidence should be improved. In this way, the effectiveness and safety of Chinese patent medicines in the treatment of P-AMI-HF can be explored.

Fibroblast growth factor 23 during septic shock and myocardial injury in ICU patients

ObjectiveFibroblast growth factor 23 (FGF23) has been recognized as an important biomarker of cardiovascular disease and is closely related to inflammation over the past decade. This study aimed to assess the relationship between FGF23 and myocardial injury in patients with sepsis. MethodsWe sequentially measured serum FGF23, Klotho, biomarkers of inflammation (CRP, IL-6 and WBC), myocardial injury (cTnI and N-terminal B-type natriuretic peptide) and sepsis (procalcitonin) at peak of intercurrent septic shock and after complete resolution or before death in a series of 29 patients with septic shock. 29 healthy adults without infections were used as controls. ResultsThere was a difference in serum FGF23 level between patients with septic shock and healthy adults (p < 0.0001), and the peak level of FGF23 in septic shock in the survivor group was higher than that after complete remission (p < 0.0001). No statistical difference was found in the level of FGF23 before and after treatment in the death group (p = 0.0947). At the peak of septic shock, FGF23 was significantly correlated with inflammatory markers, CRP (r = 0.8063, p < 0.0001), PCT (r = 0.6091, p = 0.0005) and WBC (r = 0.8312, p < 0.0001), while the correlation with IL-6 was not statistically significant (r = 0.0098, p = 0.9598). At the same time, it was found that FGF23 was significantly correlated with myocardial injury markers, cTNI (r = 0.8475, p < 0.0001) and NTproBNP (r = 0.8505, p < 0.0001). Nevertheless, FGF23 and klotho are not correlated (r = 0.2609, p = 0.1717). ConclusionIn conclusion, in patients with septic shock and myocardial injury, the exacerbation of inflammation in the septic process was accompanied by a abnormal increase of circulating FGF23 level. FGF23 also subsided after the improvement of inflammation, and the opposite was true for patients who did not survive. The up-regulation of FGF23 may be involved in the response of patients to septic shocks, and it is also speculated that FGF23 is involved in the myocardial injury of septic shock.

Chaihu Sanshen Capsules protect rats from myocardial ischemia reperfusion injury via PKCβⅡ/NOX2/ROS signaling pathway

This study aims to explore the pathogenesis of myocardial ischaemia reperfusion injury(MIRI) based on oxidative stress-mediated programmed cell death and the mechanism and targets of Chaihu Sanshen Capsules in treating MIRI via the protein kinase Cβ(PKCβⅡ)/NADPH oxidase 2(NOX2)/reactive oxygen species(ROS) signaling pathway. The rat model of MIRI was established by the ligation of the left anterior descending branch. Rats were randomized into 6 groups: sham group, model group, clinically equivalent-, high-dose Chaihu Sanshen Capsules groups, N-acetylcysteine group, and CGP53353 group. After drug administration for 7 consecutive days, the area of myocardial infarction in each group was measured. The pathological morphology of the myocardial tissue was observed by hematoxylin-eosin(HE) staining. The apoptosis in the myocardial tissue was observed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling(TUNEL). Enzyme-linked immunosorbent assay(ELISA) was employed to measure the le-vels of indicators of myocardial injury and oxidative stress. The level of ROS was detected by flow cytometry. The protein and mRNA levels of the related proteins in the myocardial tissue were determined by Western blot and real-time quantitative PCR(RT-qPCR), respectively. Compared with the sham group, the model group showed obvious myocardial infarction, myocardial structural disorders, interstitial edema and hemorrhage, presence of a large number of vacuoles, elevated levels of myocardial injury markers, myocardial apoptosis, ROS, and malondialdehyde(MDA), lowered superoxide dismutase(SOD) level, and up-regulated protein and mRNA le-vels of PKCβⅡ, NOX2, cysteinyl aspartate specific proteinase-3(caspase-3), and acyl-CoA synthetase long-chain family member 4(ACSL4) in the myocardial tissue. Compared with the model group, Chaihu Sanshen Capsules reduced the area of myocardial infarction, alleviated the pathological changes in the myocardial tissue, lowered the levels of myocardial injury and oxidative stress indicators and apoptosis, and down-regulated the mRNA and protein levels of PKCβⅡ, NOX2, caspase-3, and ACSL4 in the myocardial tissue. Chaihu Sanshen Capsules can inhibit oxidative stress and programmed cell death(apoptosis, ferroptosis) by regulating the PKCβⅡ/NOX2/ROS signaling pathway, thus mitigating myocardial ischemia reperfusion injury.

Irisin protects against cardiac injury by inhibiting NLRP3 inflammasome-mediated pyroptosis during remodeling after infarction

This study aimed to explore the cardioprotective mechanism of irisin in the context of cardiac injury. Utilizing a myocardial infarction (MI) mouse model, we investigated the therapeutic potential of recombinant human irisin (rhIrisin) administered for 28 days post-infarction. The efficacy of irisin treatment was evaluated through echocardiographic assessment of cardiac function and serum analysis of myocardial injury markers. Our research provided novel insights into the impacts of irisin on the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome activation and pyroptosis, assessed both in vivo in MI mice and in vitro in hypoxia/reoxygenation-treated H9C2 cells. Remarkably, irisin treatment significantly reduced levels of lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and troponin I, indicating reduced myocardial injury. Echocardiography highlighted substantial improvements in left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and dimensions (LVIDd and LVIDs) in irisin-treated mice, underscoring enhanced cardiac function. Moreover, irisin was shown to significantly suppress the mRNA and protein expressions of key components involved in NLRP3 inflammasome pathway (NLRP3, ASC, caspase-1 (p20), and interleukin-18 (IL-18)) both in MI-induced mice and hypoxia/reoxygenation-treated cells. This study firstly reveals that the cardioprotective effect of irisin is mediated through the attenuation of NLRP3 inflammasome activation and pyroptosis, positioning irisin as a promising therapeutic agent for cardiac injury.

The first experience of the combined use of nitric oxide and molecular hydrogen for cardiac surgery in high-risk patients

The purpose of the study was to evaluate the effectiveness of myocardial protection with a combined supply of nitric oxide (NO) (40 ppm) and hydrogen (1.2 ppm) into the gas-air mixture delivery line of the cardiopulmonary bypass (CPB) machine during the entire period of CPB.Methods. The study included patients (n = 91) who had cardiac surgery under cardiopulmonary bypass and pharmacological cold cardioplegia. Patients were randomized into 3 groups. The Group 1 (n = 30) was control. Groups 2 (n = 28) and 3 (n = 33) received an isolated supply of NO (40 ppm) and a combined supply of NO (40 ppm) and hydrogen (1.2 ppm) into the extracorporeal IR circuit, respectively. During the postoperative period, clinical and functional indicators were studied (dynamics of myocardial contractile function according to ultrasound data); duration of artificial pulmonary ventilation (ALV); stay in the intensive care unit; hospital stay; mortality; level of marker of myocardial injury – troponin I (cTnI). Myocardial injury index (MII) was calculated to assess the degree of injury.Results. It was found that the level of cTnI in the postoperative period increased statistically significantly in all groups but was statistically significantly lower in Groups 2 and 3 compared to Group 1 at the end of the surgery and 12 and 24 hours after the surgery. Also, level of cTnI was statistically significantly lower in Group 3 at all stages of the study compared to Group 1 and after 12, 24 and 48 hours compared to Group 2. Statistically significantly lower MII values were revealed at all stages of the postoperative period in Group 3 compared with Groups 1 and 2. Changes in indicators of myocardial contractile function suggest an earlier and more complete recovery in Groups 2 and 3 (the changes were statistically significantly higher than that in Group 1). In Groups 2 and 3, the incidence of acute heart failure was statistically significantly lower (p = 0.046) compared to Group 1, according to Fisher’s exact test. There were no statistically significant differences in the incidence of acute respiratory and multiple organ failure in Groups 2 and 3 compared to Group 1. Also, patients of Groups 2 and 3 did not experience any complications in the early postoperative period. In Group 3, there was a statistically significant decrease in the duration of mechanical ventilation and stay in the intensive care unit after surgery compared to Group 2.Conclusion. Isolated supply of NO into the IR circuit has an additional cardioprotective effect, which is confirmed by statistically lower levels of troponin I and smaller changes in the indicators of myocardial contractile function during the postoperative period compared to standard technology. A more pronounced protective effect on the myocardium was shown with the combined supply of NO and molecular hydrogen to the IR circuit as seen by statistically lower levels of troponin I and MII in the postoperative period compared with the isolated supply of NO.

Levels of Circulating Ketone Bodies in Patients Undergoing Cardiac Surgery on Cardiopulmonary Bypass.

Ketone bodies (KBs) are energy-efficient substrates utilized by the heart depending on its metabolic demand and substrate availability. Levels of circulating KBs have been shown to be elevated in acute and chronic cardiovascular disease and are associated with severity of disease in patients with heart failure and functional outcome after myocardial infarction. To investigate whether this pattern similarly applies to patients undergoing cardiac surgery involving cardiopulmonary bypass (CPB), we analysed prospectively collected pre- and postoperative blood samples from 192 cardiac surgery patients and compared levels and perioperative changes in total KBs with Troponin T as a marker of myocardial cell injury. We explored the association of patient characteristics and comorbidities for each of the two biomarkers separately and comparatively. Median levels of KBs decreased significantly over the perioperative period and inversely correlated with changes observed for Troponin T. Associations of patient characteristics with ketone body perioperative course showed notable differences compared to Troponin T, possibly highlighting factors acting as a "driver" for the change in the respective biomarker. We found an inverse correlation between perioperative change in ketone body levels and changes in troponin, indicating a marked decrease in ketone body concentrations in patients exhibiting greater myocardial cell injury. Further investigations aimed at better understanding the role of KBs on perioperative changes are warranted.

ATP5me alleviates high glucose-induced myocardial cell injury

BackgroundGestational diabetes mellitus (GDM) is associated with adverse myocardial remodeling and impaired cardiac function of fetus. Nevertheless, specific molecular mechanisms underlying type 1 GDM-induced fetal myocardial injury remain unknown. Therefore, this study proposes to identify possible molecular mechanisms using RNA-seq. MethodsA rat type 1 GDM model was developed using streptozotocin (STZ) (25 and 50 mg/kg), and weight and glucose tolerance of maternal and offspring were evaluated. Changes in markers of myocardial injury and oxidative stress identified by ELISA and biochemical kits in offspring hearts. Identification of differentially expressed mRNAs (DE-mRNAs) associated with myocardial injury in type 1 GDM offspring using RNA-seq. Proliferation, apoptosis, and oxidative stress were assessed in high glucose-induced H9C2 cells after exogenously modulating ATP Synthase Membrane Subunit E (ATP5me). ResultsMaternal weight, glucose and glucose tolerance, and fetal weight and heart weight were reduced in the type 1 GDM model, especially in 50 mg/kg STZ-induced. Increased of creatine kinase-MB (CK-MB), cardiac troponin T (cTnT), hypersensitive C-reactive protein (hs-CRP), reactive oxygen species (ROS) and malondialdehyde (MDA) and decreased of superoxide dismutase (SOD) were observed in type 1 GDM offspring hearts. type 1 GDM offspring hearts exhibited disorganized cardiomyocytes with enlarged gaps, broken myocardial fibers, erythrocyte accumulation and inflammatory infiltration. RNA-seq identified 462 DE-mRNAs in type 1 GDM offspring hearts, which mainly regulate immunity, redox reactions, and cellular communication. Atp5me was under-expressed in type 1 GDM offspring hearts, and high glucose decreased Atp5me expression in H9C2 cells. Overexpressing Atp5me alleviated high glucose-induced decrease in proliferation, mitochondrial membrane potential, BCL2 and SOD, and increase in apoptosis, MDA, ROS, c-Caspase-3, and BAX in H9C2 cells. ConclusionThis study first demonstrated that ATP5me attenuated type 1 GDM-induced fetal myocardial injury. This provides a possible molecular mechanism for the treatment of type 1 GDM-induced fetal myocardial injury.

Hydromorphone hydrochloride preconditioning combined with postconditioning attenuates myocardial ischemia/reperfusion injury in rats by improving mitochondrial function and activating the PI3K/Akt signaling pathway.

Thrombolytic therapy or percutaneous coronary intervention for myocardial infarction often cause myocardial ischemia/reperfusion injury (MIRI) and poor prognosis of patients. This study aimed to explore the protective effect and potential mechanism of hydromorphone hydrochloride (HH) on MIRI. Fifty Sprague-Dawley male rats were randomly divided into Sham group, I/R group, HH-pre group, HH-post group, and HH-pre + post group. Except Sham group, MIRI models were established by ligating and relaxing the left anterior descending coronary artery, followed by tail vein injection of HH (0.3 μmol/L) 10 min before ligation (HH-pre group), 10 min after reperfusion (HH-post group), and twice at the above two time points (HH-pre + post group). After intervention, the cardiac function of rats was evaluated by echocardiography, and the levels of myocardial injury markers, oxidative stress indicators, and mitochondrial function indicators were detected. Next, the myocardial infarction area was evaluated by 2,3,5-triphenyltetrazolium chloride staining, mitochondrial biogenesis, and phosphoinositide 3 kinase (PI3K)/protein kinase B (Akt) signaling pathway by western blot. Compared with the I/R group, HH intervention improved cardiac function, decreased myocardial infarction area, reduced serum myocardial injury markers, alleviated oxidative stress, improved mitochondrial function, up-regulated mitochondrial biogenesis, and activated PI3K/Akt signaling pathway. Moreover, the HH-pre + post group was superior to the HH-pre and HH-post groups in the above aspects. Collectively, HH had protective effect on MIRI rats, and HH preconditioning combined with postconditioning showed optimal efficacy. Such efficacy may be achieved by promoting mitochondrial biogenesis to improve mitochondrial function and reduce oxidative stress, and activating the PI3K/Akt signaling pathway.

Rhein alleviates myocardial ischemic injury by inhibiting mitochondrial division, activating mitochondrial autophagy and suppressing myocardial cell apoptosis through the Drp1/Pink1/Parkin pathway.

Rhein, which has antioxidant and anti-inflammatory response properties, is a beneficial treatment for different pathologies. However, the mechanism by which rhein protects against myocardial ischemic injury is poorly understood. To establish an acute myocardial infarction (AMI) rat model, we performed left anterior descending (LAD) ligation. Sprague‒Dawley rats were randomly divided into four groups: sham, AMI, AMI + rhein (AMI + R), and AMI + mitochondrial fission inhibitor (AMI + M). The extent of myocardial injury was evaluated by TTC staining, serum myocardial injury markers, and HE and Masson staining. Cardiac mitochondria ultrastructure was visualized by transmission electron microscopy. TUNEL assay and flow cytometry analysis were used to estimate cell apoptosis. Protein expression levels were measured by Western blotting. In vitro, the efficacy of rhein was assessed in H9c2 cells under hypoxic condition. Our results revealed that rats with AMI exhibited increased infarct size and indicators of myocardial damage, along with activation of Drp1-dependent mitochondrial fission, decreased mitophagy and increased apoptosis rates. However, pretreatment with rhein significantly reversed these effects and demonstrated similar efficacy to Mdivi-1. Furthermore, rhein pretreatment protected against myocardial ischemic injury by inhibiting mitochondrial fission, as evidenced by decreased Drp1 expression. It also enhanced mitophagy, as indicated by increased expression of Beclin1, Pink1 and Parkin, an increased LC3-II/LC3-I ratio and increased formation of autolysosomes. Additionally, rhein pretreatment mitigated apoptosis in AMI. These results were also confirmed in vitro in H9c2 cells. Our results demonstrate that rhein pretreatment exerts cardioprotective effects against myocardial ischemic injury via the Drp1/Pink1/Parkin pathway.

Betulinic acid reduces inflammation in rats with sepsis‐induced myocardial dysfunction by inhibiting TLR4/MyD88/NF‐κB signaling pathway

AbstractIn this study, we aimed to investigate the effect and underlying mechanism of betulinic acid (BA) on myocardial dysfunction in septic rats. Twenty‐four male Sprague–Dawley rats were randomly allocated into four groups (n = 6 rats/group): the sham operation (Control) group, the cecal ligation and puncture (CLP) group, the BA 10 mg/kg group, and the BA 50 mg/kg group. The septic rat model was induced through cecal ligation and puncture in the CLP and BA groups, except for the Control group. Then, cardiac function parameters were assessed using echocardiography, myocardial injury markers were quantified via biochemical assays, and myocardial histopathological injuries were observed through H&amp;E staining. Inflammatory factors in the serum were measured using ELISA assays, immunohistochemistry and qRT‐PCR were performed to determine macrophage numbers and the expression of iNOS, CD86, Arg‐1, and Mrc1 in myocardial tissue. The protein expression levels of TLR4, Myd88, and NF‐κB in myocardial tissue were assessed through western blot analysis. The results showed that BA significantly improved cardiac function, reduced myocardial injury, and attenuated inflammation in CLP rats. Specifically, BA decreased LVEDD and LVESD while increasing LVEF and LVFS. Furthermore, BA upregulated the levels of BNP, cTnT, CK‐MB, LDH, IL‐6, IL‐1β, and TNF‐α in CLP rat serum. Additionally, BA reduced macrophage infiltration, inhibited M1/M2 gene expression, and downregulated TLR4, Myd88 and NF‐κB protein expression in CLP rats myocardial tissues. In conclusion, BA can inhibit myocardial inflammation and prevent sepsis‐induced myocardial dysfunction by inhibiting TLR4/MyD88/NF‐κB signaling, thereby promoting M2 macrophage polarization in myocardial tissues.

Geomagnetic activity affects animal myocardial ischemia/reperfusion injury: an experimental-simulated study

Numerous studies have shown that geomagnetic activity (GMA) contributes to the development and escalation of cardiovascular disease (CVD), as well as increased morbidity and mortality. However, the underlying molecular mechanisms and approaches for understanding GMA remain unclear. This study aimed to investigate the impact of GMA on oxidative stress and inflammatory responses. Myocardial ischemia/reperfusion injury (MI/RI) rat models were created under various geomagnetic field conditions. The range of cardiac function, markers of myocardial injury, inflammatory factors, and the TLR4/NF-κB signaling pathway were measured after the 24-h period. The findings showed that weak GMA significantly improved cardiac function in the MI/RI rat model and reduced the size of myocardial infarction and creatine kinase (CK) and lactic dehydrogenase (LDH) levels. Additionally, weak GMA enhanced superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) content. Furthermore, weak GMA significantly reduced the levels of the myocardial inflammatory cytokines interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). Conversely, the effects observed under severe GMA conditions were opposite to those observed under weak GMA. Western blot and qPCR analysis demonstrated that weak GMA led to a significant downregulation of TLR4, TRAF6, NF-κB, TNF-α, and MCP-1 in the MI/RI rat models. In contrast to weak GMA, severe GMA increased TLR4, TRAF6, NF-κB, and TNF-α expression. This study suggested that weak GMA had a limiting effect on MI/RI rat models, whereas severe GMA exacerbated injury in MI/RI rats. These effects were associated with oxidative stress and inflammatory responses and might potentially involve the TLR4/NF-κB signaling pathway.

Correlation between high-sensitivity cardiac troponin I, lactate levels, and clinical outcomes in on-pump coronary artery bypass grafting

Background: On-pump coronary artery bypass graft (CABG) causes myocardial damage and hypoperfusion. However, it is unknown how varied timings of combining serum high-sensitivity cardiac troponin I (hs-cTnI) and lactate levels in on-pump CABG surgery would affect clinical outcomes. Objectives: This study aims to evaluate serum hs-cTnI and lactate levels and their influence on postoperative clinical outcomes in patients with on-pump CABG. Materials and methods: Eleven coronary artery disease (CAD) patients were included for on-pump CABG surgery. The biomarkers were collected at four stages of onpump CABG: before sternotomy (T0, pre-cardiopulmonary bypass (pre-CPB)), 5 minutes before aortic cross-clamp of CPB (T1, preaortic cross-clamp), after aortic cross-clamp (T2, postaortic cross-clamp), and 24 hrs post-surgery in an intensive care unit (T3, ICU at 24 hrs). Results: Correlation analysis revealed that during the study period, average hs-cTnI is positively associated with lactate levels (r=0.775, p=0.005). However, 24 hours after surgery, lactate levels return more quickly than hs-cTnI levels. The average hs-cTnI and lactate levels were positively correlated with CPB time and aortic clamp time. Regarding clinical outcomes, average hs-cTnI, and lactate levels were positively associated with a length of ICU stay (r=0.717 and 0.612, p=0.013 and 0.045, respectively). However, only the lactate levels were associated with ventilator support time (r=0.674, p=0.023). Conclusion: We demonstrated that hs-cTnI and lactate levels are important markers of myocardial injury in association with hypoperfusion during on-pump CABG, and it could be used to monitor the postoperative outcome.

Mechanisms by which silencing long-stranded noncoding RNA KCNQ1OT1 alleviates myocardial ischemia/reperfusion injury (MI/RI)-induced cardiac injury via miR-377-3p/HMOX1

BackgroundThe key complication of myocardial infarction therapy is myocardial ischemia/reperfusion injury (MI/RI), and there is no effective treatment. The present study elucidates the mechanism of action of lncRNA KCNQ1OT1 in alleviating MI/RI and provides new perspectives and therapeutic targets for cardiac injury-related diseases.MethodsAn ischemia/reperfusion (I/R) injury model of human adult cardiac myocytes (HACMs) was constructed, and the expression of KCNQ1OT1 and miR-377-3p was determined by RT‒qPCR. The levels of related proteins were detected by western blot analysis. Cell proliferation was detected by a CCK-8 assay, and cell apoptosis and ROS content were determined by flow cytometry. SOD and MDA expression as well as Fe2+ changes were detected by related analysis kits. The target binding relationships between lncRNA KCNQ1OT1 and miR-377-3p as well as between miR-377-3p and heme oxygenase 1 (HMOX1) were verified by a dual-luciferase reporter gene assay.ResultsMyocardial ischemia‒reperfusion caused oxidative stress in HACMs, resulting in elevated ROS levels, increased Fe2+ levels, decreased cell viability, and increased LDH release (a marker of myocardial injury), and apoptosis. KCNQ1OT1 and HMOX1 were upregulated in I/R-induced myocardial injury, but the level of miR-377-3p was decreased. A dual-luciferase reporter gene assay indicated that lncRNA KCNQ1OT1 targets miR-377-3p and that miR-377-3p targets HMOX1. Inhibition of HMOX1 alleviated miR-377-3p downregulation-induced myocardial injury. Furthermore, lncRNA KCNQ1OT1 promoted the level of HMOX1 by binding to miR-377-3p and aggravated myocardial injury.ConclusionLncRNA KCNQ1OT1 aggravates ischemia‒reperfusion-induced cardiac injury via miR-377-3P/HMOX1.

Colchicine ameliorates myocardial injury induced by coronary microembolization through suppressing pyroptosis via the AMPK/SIRT1/NLRP3 signaling pathway

BackgroundCoronary microembolization(CME)is a common complication in acute coronary syndrome and percutaneous coronary intervention, which is closely related to poor prognosis. Pyroptosis, as an inflammatory programmed cell death, has been found to be associated with CME-induced myocardial injury. Colchicine (COL) has potential benefits in coronary artery disease due to its anti-inflammatory effect. However, the role of colchicine in pyroptosis-related CME-induced cardiomyocyte injury is unclear. This study was carried out to explore the effects and mechanisms of colchicine on myocardial pyroptosis induced by CME.MethodsThe CME animal model was constructed by injecting microspheres into the left ventricle with Sprague-Dawley rats, and colchicine (0.3 mg/kg) pretreatment seven days before and on the day of modeling or compound C(CC)co-treatment was given half an hour before modeling. The study was divided into 4 groups: Sham group, CME group, CME + COL group, and CME + COL + CC group (10 rats for each group). Cardiac function, serum myocardial injury markers, myocardial histopathology, and pyroptosis-related indicators were used to evaluate the effects of colchicine.ResultsColchicine pretreatment improved cardiac dysfunction and reduced myocardial injury induced by CME. The main manifestations were the improvement of left ventricular systolic function, the decrease of microinfarction area, and the decrease of mRNA and protein indexes related to pyroptosis. Mechanistically, colchicine increased the phosphorylation level of adenosine monophosphate-activated protein kinase (AMPK), promoted the expression of silent information regulation T1 (SIRT1), and inhibited the expression of NOD-like receptor pyrin containing 3 (NLRP3) to reduce myocardial pyroptosis. However, after CC co-treatment with COL, the effect of colchicine was partially reversed.ConclusionColchicine improves CME-induced cardiac dysfunction and myocardial injury by inhibiting cardiomyocyte pyroptosis through the AMPK/SIRT1/NLRP3 signaling pathway.

A network pharmacology approach to decipher the mechanism of total flavonoids from Dracocephalum Moldavica L. in the treatment of cardiovascular diseases

Aim of the studyCardiovascular disease (CVD) seriously endangers human health and is characterized by high mortality and disability. The effectiveness of Dracocephalum moldavica L. in the treatment of CVD has been proven by clinical practice. However, the mechanism by which DML can treat CVD has not been systematically determined.Materials and methodsThe active compounds in DML were screened by literature mining and pharmacokinetic analysis. Cytoscape software was used to construct the target-disease interaction network of DML in the treatment of CVD. Gene ontology and signalling pathway enrichment analyses were performed. The key target pathway network of DML compounds was constructed and verified by pharmacological experiments in vitro. A hydrogen glucose deprivation/reoxygenation model was established in H9c2 cells using hypoxia and glucose deprivation for 9 h combined with reoxygenation for 2 h. The model simulated myocardial ischaemic reperfusion injury to investigate the effects of total flavonoids of Cymbidium on cell viability, myocardial injury markers, oxidative stress levels, and reactive oxygen radical levels. Western blot analysis was used to examine NOX-4, Bcl-2/Bax, and PGC-1α protein expression.ResultsTwenty-seven active components were screened, and 59 potential drug targets for the treatment of CVD were obtained. Through the compound-target interaction network and the target-disease interaction network, the key targets and key signalling pathways, such as NOX-4, Bcl-2/Bax and PGC-1α, were obtained. TFDM significantly decreased LDH and MDA levels and the production of ROS and increased SOD activity levels in the context of OGD/R injury. Further studies indicated that NOX-4 and Bax protein levels and the p-P38 MAPK/P38 MAPK andp-Erk1/2/Erk1/2 ratios were suppressed by TFDM. The protein expression of Bcl-2 and PGC-1α was increased by TFDM.ConclusionsOur results showed that DML had multicomponent, multitarget and multichannel characteristics in the treatment of CVD. The mechanism may be associated with the following signalling pathways: 1) the NOX-4/ROS/p38 MAPK signalling pathway, which inhibits inflammation and reactive oxygen species (ROS) production, and 2) the Bcl-2/Bax and AMPK/SIRT1/PGC-1α signalling pathways, which inhibit apoptosis.

Effect of intraoperative dexmedetomidine on heart-type fatty acid binding protein, CK-MB, and cardiac troponin I levels, and postoperative delirium in patients with heart valve replacement.

This retrospective study aimed to evaluate the impact of intraoperative dexmedetomidine on myocardial injury markers (heart-type fatty acid binding protein [H-FABP], creatine kinase-mb [CK-MB], and cardiac troponin I [cTnI]) and postoperative delirium in patients undergoing heart valve replacement. Clinical data from 160 cardiac patients who underwent heart valve replacement with cardiopulmonary bypass (CPB) between January 2019 and January 2024 were analyzed. Patients were divided into an observation group (n = 82) receiving dexmedetomidine and a control group (n = 78) without dexmedetomidine. After propensity score matching, both groups comprised 53 patients each. Outcome measures included myocardial injury markers, postoperative delirium incidence, and perioperative parameters. The observation group showed shorter postoperative recovery durations, reduced intraoperative sufentanil requirements, and lower myocardial injury markers 1 day postoperatively (all P < 0.001). No significant differences were found in midazolam dosages (all P > 0.05), while propofol and sufentanil dosages were lower in the observation group (both P < 0.001). The incidence of postoperative delirium was significantly lower in the observation group (P = 0.014), with cardioversion time and propofol dosage identified as delirium risk factors. Dexmedetomidine use during heart valve replacement surgery was associated with improved postoperative outcome, including reduced myocardial injury and lower postoperative delirium incidence. These findings suggest a potential role for dexmedetomidine in enhancing patient recovery, although further research is needed to explain its impact on postoperative delirium.