Fisetin suppresses atherosclerosis by inhibiting ferroptosis-related oxidative stress in apolipoprotein E knockout mice.

INTRODUCTION: Fisetin has been demonstrated to inhibit the occurrence of atherosclerosis, however, the mechanism of fisetin suppressing atherosclerosis remains elusive. METHODS: The function of fisetin in the inhibition of atherosclerosis was evaluated by hematoxylin and eosin and Oil Red O staining in ApoE-/- mice. Molecular biomarkers of atherosclerosis progression were detected by Western blot and qPCR. Moreover, the inhibition of atherosclerosis on oxidative stress and ferroptosis was evaluated by immunofluorescence staining, qPCR and Western blot assays. RESULTS: The obtained results showed that serum lipid was attenuated and consequentially the formation of atherosclerosis was also suppressed by fisetin in ApoE-/- mice. Exploration of the mechanism revealed that molecular biomarkers of atherosclerosis were decreased under fisetin treatment. The level of reactive oxygen species and malondialdehyde declined, while the activity of superoxide dismutases and glutathione peroxidase was increased under the fisetin treatment. Additionally, the suppressor of ferroptosis, glutathione peroxidase 4 protein, was elevated. The ferritin was decreased in the aortic tissues treated with fisetin. CONCLUSIONS: In summary, fisetin attenuated the formation of atherosclerosis through the inhibition of oxidative stress and ferroptosis in the aortic tissues of ApoE-/- mice.

Downregulating miRNA-199a-5p exacerbates fluorouracil-induced cardiotoxicity by activating the ATF6 signaling pathway.

BACKGROUND: Fluorouracil (5-FU) might produce serious cardiac toxic reactions. miRNA-199a-5p is a miRNA primarily expressed in myocardial cells and has a protective effect on vascular endothelium. Under hypoxia stress, the expression level of miRNA-199a-5p was significantly downregulated and is closely related to cardiovascular events such as coronary heart disease, heart failure, and hypertension. We explored whether 5-FU activates the endoplasmic reticulum stress ATF6 pathway by regulating the expression of miRNA-199a-5p in cardiac toxicity. METHODS: This project established a model of primary cardiomyocytes derived from neonatal rats and treated them with 5-FU in vitro. The expression of miRNA-199a-5p and its regulation were explored in vitro and in vivo. RESULTS: 5-FU decreases the expression of miRNA-199a-5p in cardiomyocytes, activates the endoplasmic reticulum stress ATF6 pathway, and increases the expression of GRP78 and ATF6, affecting the function of cardiomyocytes, and induces cardiac toxicity. The rescue assay further confirmed that miRNA-199a-5p supplementation can reduce the cardiotoxicity caused by 5-FU, and its protective effect on cardiomyocytes depends on the downregulation of the endoplasmic reticulum ATF6 signaling pathway. CONCLUSIONS: 5-FU can down-regulate expression of miRNA-199a-5p, then activate the endoplasmic reticulum stress ATF6 pathway, increase the expression of GRP78 and ATF6, affect the function of cardiomyocytes, and induce cardiac toxicity.

Metformin alleviates bevacizumab-induced vascular endothelial injury in mice through growth differentiation factor 15 upregulation.

Objectives: Bevacizumab is a commonly used anticancer drug in clinical practice, but it often leads to adverse reactions such as vascular endothelial damage, hypertension, arterial and venous thrombosis, and bleeding. This study investigated the protective effects of metformin against bevacizumab-induced vascular injury in a mouse model and examined the possible involvement of GDF15/PI3K/AKT/FOXO/PPARγ signaling in the effects. Materials and Methods: C57 male mice were purchased. To investigate metformin, the mice were assigned to the saline, bevacizumab (15 mg every 3 days), metformin (1200 mg/day), and bevacizumab+metformin groups. To investigate GDF15, the mice were assigned to the siNC+bevacizumab, siNC+bevacizumab+metformin, siGDF15+bevacizumab, and siGDF15+bevacizumab+metformin groups. Histological staining was used to evaluate vascular injury. Flow cytometry was used to evaluate apoptosis. ELISA was used to measure plasma endothelial injury markers and proinflammatory cytokines. qRT-PCR and western blot were used to determine the expression of GDF15 and PI3K/AKT/FOXO/PPARγ in aortic tissues. Results: Metformin alleviated bevacizumab-induced abdominal aortic injury, endothelial cell apoptosis, and systemic inflammation in mice (all P<0.05). Metformin up-regulated GDF15 expression and PI3K/AKT/FOXO/PPARγ signaling in the abdominal aorta of mice treated with bevacizumab (all P<0.05). siGDF15 abolished the vascular protective and anti-inflammatory effects of metformin (all P<0.05). siGDF15 suppressed PI3K/AKT/FOXO/PPARγ signaling in the abdominal aorta of mice treated with bevacizumab (all P<0.05). Conclusion: Metformin attenuates bevacizumab-induced vascular endothelial injury, apoptosis, and systemic inflammation by activating GDF15/PI3K/AKT/FOXO/PPARγ signaling.

Monocyte/High-Density Lipoprotein Ratio Is Associated with Atrial High-Rate Episodes within One Year Detected by Cardiac Implantable Electronic Devices.

OBJECTIVE: To investigate the risk factors for predicting atrial high-rate episodes (AHREs) detected by cardiac implantable electronic devices (CIEDs). METHODS: A total of 140 patients with CIED in our hospital from June 2013 to June 2018 were included and were followed up to observe whether they had AHREs. AHRE are defined as atrial rate ≥ 175 times/minute, lasting > 5 minutes, and reviewed by an experienced electrophysiologist with unclear clinical diagnosis. The patients fasted for 12 hours after implantation, and blood samples were collected for biochemical, lipid, and whole blood count detection. Follow-up was regular after discharge to record follow-up data of each patient and conduct statistical analysis. RESULTS: One hundred and forty patients were implanted with dual-chamber pacemakers, their median age was 70 years old, 44.29% were male, 27 patients had AHRE within one year, and AHRE incidence rate was 19.29%. The microcytic to hypochromic (M/H) ratio was calculated for all AHRE patients and compared with the patients without AHRE; the M/H value of AHRE patients was significantly higher. Throughout the entire follow-up period, a total of 44 patients developed AHRE; when adjusted by multivariate analysis, only M/H ratio ≥ 4.5 vs. < 4.5 had statistical significance, and the adjusted hazard ratio value was 4.313 (1.675-11.105). CONCLUSION: As an indicator, M/H ratio may play an important role in the occurrence and development of atrial fibrillation and can be used as a predictor of AHRE in patients with CIED.

The relationship between insulin resistance, serum alkaline phosphatase, and left ventricular dysfunction following myocardial infarction.

The occurrence of heart failure following acute myocardial infarction (AMI) significantly increases the risk of post-infarction mortality. Alkaline phosphatase (AP) is considered to be an independent predictor of cardiovascular disease (CVD) and adverse outcomes. Furthermore, in recent years, alkaline phosphatase has been associated with insulin resistance (IR). Our aim was to investigate the correlation between IR substitutes (triglyceride-glucose (TyG) index, triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio), AP, and LV dysfunction in patients admitted after AMI. The retrospective study included 810 patients who underwent coronary angiography for myocardial infarction at the First Hospital of Hebei Medical University from August 2018 to December 2021. Patients were categorized into three groups based on their serum AP levels. Clinical characteristics at admission, cardiac echocardiography findings, coronary angiography results, and biochemical markers such as serum AP levels and triglycerides (TG) were recorded during hospitalization. Left ventricular ejection fraction (LVEF) was assessed using cardiac echocardiography conducted from the time of admission until the coronary angiography procedure. A total of 774 patients with AMI were included in this study. The TyG index is significantly correlated with the TG/HDL-C ratio. (R = 0.739, P < 0.001). Binary logistic regression analysis revealed that elevated serum AP (OR 2.598, 95% CI 1.331-5.071, P = 0.005), presence of the left anterior descending (LAD) artery as the infarct-related artery (IRA) (OR 2.452, 95% CI 1.352-4.449, P = 0.003), and triglyceride (TG) levels (OR 0.652, 95% CI 0.429-0.992, P = 0.046) were protective risk factor for an admission LVEF < 40% following AMI. The serum alkaline phosphatase and LAD as IRA are independent risk factors for severe reduction in LVEF during hospitalization for AMI. Conversely, triglyceride are independent protective factor for severe reduction in LVEF during AMI hospitalization.

Toxic Effects of Copper Fungicides on the Development and Behavior of Zebrafish in Early-Life Stages.

Copper-based fungicides have been used to control various plant diseases for more than one hundred years and play very important roles in agriculture. Accumulation of copper in freshwater and environment pose severe threats to human health and the environment. The current study evaluated the developmental and behavioral toxicity of PEG@Cu NCs (copper nanoclusters), Kocide® 3000 (copper hydroxide), and Cu(CH3COO)2 (copper acetate) to zebrafish in early-life stages. The developmental toxicity was evaluated according to the parameters of mortality, hatching rate, autonomous movement and heartbeat of embryos, and body length of larvae. The 9 dpf (days postfertilization)-LC50 (50% lethal concentration) of embryonic mortality was 0.077, 0.174 or 0.088 mg/L, and the 9 dpf-EC50 (effective concentration of 50% embryos hatching) of hatching rate was 0.079 mg/L, 0.21 mg/L and 0.092 mg/L when the embryos were exposed to PEG@Cu NCs, Kocide® 3000 or Cu(CH3COO)2, respectively. Kocide® 3000 and Cu(CH3COO)2 obviously decreased the spontaneous movements, while PEG@Cu NCs had no adverse effects on that of embryos. The reduced heartbeat can return to normal after exposure to PEG@Cu NCs for 96 h, while it cannot recover from Kocide® 3000. In addition, Kocide® 3000 (≥0.2 mg/L), PEG@Cu NCs and Cu(CH3COO)2 with 0.05 mg/L or higher concentration exhibited obvious behavioral toxicity to zebrafish larvae according to the parameters of movement distance, average velocity, absolute sinuosity, absolute turn angle and absolute angular velocity.

Probing the communication patterns of different chondrocyte subtypes in osteoarthritis at the single cell level using pattern recognition and manifold learning.

The patterns of communication among different chondrocyte subtypes in human cartilage degeneration and regeneration help us understand the microenvironment of osteoarthritis and optimize cell-targeted therapies. Here, a single-cell transcriptome dataset of chondrocytes is used to explore the synergistic and communicative patterns of different chondrocyte subtypes. We collected 1600 chondrocytes from 10 patients with osteoarthritis and analyzed the active communication patterns for the first time based on network analysis and pattern recognition at the single-cell level. Manifold learning and quantitative contrasts were performed to analyze conserved and specific communication pathways. We found that ProCs (Proliferative chondrocytes), ECs (Effector chondrocytes), preHTCs (Prehypertrophic chondrocytes), HTCs (Hypertrophic chondrocytes), and FCs (Fibrocartilage chondrocytes) are more active in incoming and outgoing signaling patterns, which is consistent with studies on their close functional cooperation. Among them, preHTCs play multiple roles in chondrocyte communication, and ProCs and preHTCs have many overlapping pathways. These two subtypes are the most active among all chondrocyte subtypes. Interestingly, ECs and FCs are a pair of "mutually exclusive" subtypes, of which ECs are predominant in incoming patterns and FCs in outgoing patterns. The active signaling pathways of ECs and FCs largely do not overlap. COLLAGEN and LAMININ are the main pivotal pathways, which means they are very important in the repair and expansion of joint homeostasis. Notably, only preHTCs assume multiple roles (including sender, receiver, mediator, and influencer) and are involved in multiple communication pathways. We have examined their communication patterns from the perspective of cellular interactions, revealed the relationships among different chondrocyte subtypes, and, in particular, identified a number of active subtypes and pathways that are important for targeted therapy in the osteoarthritic microenvironment. Our findings provide a new research paradigm and new insights into understanding chondrocyte activity patterns in the osteoarthritic microenvironment.

Single-cell communication patterns and their intracellular information flow in synovial fibroblastic osteoarthritis and rheumatoid arthritis.

BACKGROUND: Synovial fibroblasts are critical for maintaining homeostasis in major autoimmune diseases involving joint inflammation, including osteoarthritis and rheumatoid arthritis. However, little is known about the interactions among different cell subtypes and the specific sets of signaling pathways and activities that they trigger. METHODS: Using social network analysis, pattern recognition, and manifold learning approaches, we identified patterns of single-cell communication in OA (osteoarthritis) and RA (rheumatoid arthritis). RESULTS: Our results suggest that OA and RA have distinct cellular communication patterns and signaling pathways. The LAMININ (Laminin) and COLLAGEN (Collagen) pathways predominate in osteoarthritis, while the EGF (Epidermal growth factor), NT (Neurotrophin) and CDH5 (Cadherin 5) pathways predominate in rheumatoid arthritis, with a central role for THY1 (Thy-1 cell surface antigen) +CDH11 (Cadherin 11) + cells. The OA opens the PDGF (Platelet-derived growth factors) pathway (driver of bone angiogenesis), the RA opens the EGF pathway (bone formation) and the SEMA3 (Semaphorin 3A) pathway (involved in immune regulation). Interestingly, we found that OA no longer has cell types involved in the MHC complex (Major histocompatibility complex) and their activity, whereas the MHC complex functions primarily in RA in the presentation of inflammatory antigens, and that the complement system in OA has the potential to displace the function of the MHC complex. The specific signaling patterns of THY1+CDH11+ cells and their secreted ligand receptors are more conducive to cell migration and lay the foundation for promoting osteoclastogenesis. This subpopulation may also be involved in the accumulation of lymphocytes, affecting the recruitment of immune cells. Members of the collagen family (COL1A1 (Collagen Type I Alpha 1 Chain), COL6A2 (Collagen Type VI Alpha 2 Chain) and COL6A1 (Collagen Type VI Alpha 1 Chain)) and transforming growth factor (TGFB3) maintain the extracellular matrix in osteoarthritis and mediate cell migration and adhesion in rheumatoid arthritis, including the PTN (Pleiotrophin) / THBS1 (Thrombospondin 1) interaction. CONCLUSION: Increased understanding of the interaction networks between synovial fibroblast subtypes, particularly the shared and unique cellular communication features between osteoarthritis and rheumatoid arthritis and their hub cells, should help inform the design of therapeutic agents for inflammatory joint disease.

Potential diagnostic biomarkers: 6 cuproptosis- and ferroptosis-related genes linking immune infiltration in acute myocardial infarction.

The current diagnostic biomarkers of acute myocardial infarction (AMI), troponins, lack specificity and exist as false positives in other non-cardiac diseases. Previous studies revealed that cuproptosis, ferroptosis, and immune infiltration are all involved in the development of AMI. We hypothesize that combining the analysis of cuproptosis, ferroptosis, and immune infiltration in AMI will help identify more precise diagnostic biomarkers. The results showed that a total of 19 cuproptosis- and ferroptosis-related genes (CFRGs) were differentially expressed between the healthy and AMI groups. Functional enrichment analysis showed that the differential CFRGs were mostly enriched in biological processes related to oxidative stress and the inflammatory response. The immune infiltration status analyzed by ssGSEA found elevated levels of macrophages, neutrophils, and CCR in AMI. Then, we screened 6 immune-related CFRGs (CXCL2, DDIT3, DUSP1, CDKN1A, TLR4, STAT3) to construct a nomogram for predicting AMI and validated it in the GSE109048 dataset. Moreover, we also identified 5 pivotal miRNAs and 10 candidate drugs that target the 6 feature genes. Finally, RT-qPCR analysis verified that all 6 feature genes were upregulated in both animals and patients. In conclusion, our study reveals the significance of immune-related CFRGs in AMI and provides new insights for AMI diagnosis and treatment.

Glyphosate-based herbicide (GBH) challenged thermoregulation in lizards (Eremias argus), compensatory warming could mitigate this effect.

Chemical pollution and global warming are two major threats to reptiles, and these two factors can interact with each other. Glyphosate have attracted worldwide attention due to their ubiquitous occurrence, yet their impact on reptiles remains unknown. We designed a crossover experiment with different external GBH exposures (control/GBH) x different environmental temperatures (current climate treatment/warmer climate treatment) over 60 days to simulate environmental exposure in the Mongolian Racerunner lizard (Eremias argus). Preferred body temperature and active body temperature data were collected to calculate the accuracy of thermoregulation, while liver detoxification metabolic enzymes, oxidative stress system function, and the non-targeted metabolome of the brain tissue were assessed. Warmer-treated lizards adjusted their physiological levels and behavioral strategies in response to increased ambient temperatures and maintained body temperature homeostasis at moderate thermal perturbations. GBH-treated lizards suffered from oxidative damage to the brain tissue and abnormal histidine metabolism, thus their thermoregulatory accuracy reduced. Interestingly, at elevated ambient temperatures, GBH treatment did not affect on their thermoregulatory, possibly through several temperature-dependent detoxification mechanisms. Importantly, this data suggested that the subtle toxicological effects of GBH may threaten increasingly thermoregulation behavior of E. argus with species-wide repercussions, as climate change and exposure time extension.

The histone deacetylase inhibitor SAHA exerts a protective effect against myocardial ischemia/reperfusion injury by inhibiting sodium-calcium exchanger.

Calcium overload performs a crucial function in the pathogenesis of myocardial ischemia-reperfusion (I/R) damage, which contributes to mitochondrial impairment and apoptosis of cardiomyocytes. Suberoylanilide hydroxamic acid (SAHA), a small molecule histone deacetylases inhibitor with modulatory capacity on Na+-Ca2+ exchanger (NCX), is proven to have protective potential towards cardiac remodeling and injury, but the mechanism remains unclear. Hence, Hence, our present research explored the modulation of NCX-Ca2+-CaMKII by SAHA in myocardial I/R damage. Our outcomes indicate that in vitro hypoxia and reoxygenation models of myocardial cells, SAHA treatment inhibited the increase in expression of NCX1, intracellular Ca2+ concentration, expression of CaMKII and self-phosphorylated CaMKII, and cell apoptosis. In addition, SAHA treatment improved myocardial cell mitochondrial swelling inhibited mitochondrial membrane potential diminution and the openness of the mitochondrial permeability transition pore, and protected against mitochondrial dysfunction following I/R injury. In vivo, SAHA treatment alleviated the decrease in FS% and EF%, the increase in the myocardial infarct area, and myocardial enzyme levels caused by I/R injury, while also reducing myocardial cell apoptosis, and inhibiting mitochondrial fission and mitochondrial membrane rupture. These results indicated that SAHA treatment alleviated myocardial cell apoptosis as well as mitochondrial dysfunction resulting from myocardial I/R impairment, and contributed to myocardial function recovery by inhibiting the NCX-Ca2+-CaMKII pathway. These findings offered additional theoretical support to explore the mechanism of SAHA as a therapeutic agent in cardiac I/R damage and develop new treatment strategies.

The Action and Mechanism of Trehalose on GATA4 Autophagy Degradation and Ventricular Remodeling.

OBJECTIVE: To probe the effect of trehalose on myocardial hypertrophy and its specific molecular mechanism. METHODS: C57BL/6J male mice were divided into four subgroups: Sham operation subgroup (Sham), negative sham subgroup (Sham+Trehalose), transverse aortic constriction (TAC), and trehalose treatment subgroup (TAC+Trehalose). Immediately after the TAC operation, trehalose at a dose of 10 mg/kg was given daily via gavage. After four weeks, changes in cardiac function were evaluated using ultrasound to measure EF (ejection fraction), FS (fractional shortening), IVRT (isovolumic relaxation time), MPI (myocardial performance index), Tau (isovolumic relaxation time constant), LVESP (left ventricular end-systolic pressure), and EDPVR (end-diastolic pressure-volume relationship). The profiles of autophagy-associated proteins (p62, LC3II/I, and Beclin-1) and GATA4 protein in mice myocardial tissues were assessed by Western blotting (WB). Myocardial cells were classified from TAC mice into five groups: Control, Trehalose, Phenylephrine (PE), PE+Trehalose, and PE+Trehalose+autophagy inhibitor chloroquine groups. In the PE group, cardiomyocytes were treated with 50 µmol/L PE. Then, the cells were treated with trehalose (100 µmol/L), trehalose (100 µmol/L)+autophagy (20 µmol/L) for 24 hours respectively. The Control group was treated with the same amount of normal saline. Flow cytometry was utilized to detect myocardial cell apoptosis in each subgroup. The alterations in apoptosis and autophagy-correlated proteins (p62, LC3II/I, and Beclin-1) were assessed by WB. Additionally, the level of GATA4 protein upstream of autophagy was estimated. Furthermore, the expression levels of pro-apoptotic proteins Bad, BAX, Cleaved-caspase-3, and anti-apoptotic protein Bcl-2 were examined by WB. RESULTS: The TAC operation significantly augmented myocardial hypertrophy, heart weight-to-body weight ratio, and myocardial cell apoptosis in mice (p < 0.05). Trehalose significantly improved cardiac hypertrophy, cardiomyocyte apoptosis, and cardiac function decline in mice. Additionally, it also significantly enhanced autophagy in mouse cardiac tissues (p < 0.05). At the cellular level, trehalose significantly decreased PE-elicited apoptosis and promoted the protein expressions of Beclin-1 and LC3 II/I in cardiomyocytes while significantly dampening the profiles of p62 and GATA4 in cells. The effect of trehalose and chloroquine treatment was significantly greater than that of the trehalose group. CONCLUSIONS: Trehalose significantly abates myocardial hypertrophy and pressure overload-induced cardiomyocyte apoptosis in mice. The cardioprotective effect of trehalose on enhanced autophagy is attributed, at least in part, to the promotion of autophagic degradation of GATA4.

Compound Kushen injection attenuates angiotensin II­mediated heart failure by inhibiting the PI3K/Akt pathway.

Compound Kushen injection (CKI) is a type of traditional Chinese medicine that has previously been studied for the treatment of various types of cancer. Previous studies have reported that CKI regulates cell apoptosis by downregulating the PI3K/Akt pathway. The present study aimed to determine whether CKI alleviates heart failure (HF) by attenuating cardiomyocyte apoptosis via the inhibition of the PI3K/Akt pathway. Angiotensin II (Ang II) was used to elicit HF, and osmotic minipumps with either Ang II (2 µg/kg/day) or phosphate­buffered saline (PBS; 200 µl) were subcutaneously implanted into 6­week­old male C57BL/6 mice for 3 weeks. In addition, PBS or CKI (25 mg/kg/day) were subcutaneously infused once a day for 3 weeks. Echocardiography was used to examine hemodynamics. The myocardial injury biomarkers, cardiac troponin I and N­terminal (NT)­pro hormone B­type natriuretic peptide, were assessed using enzyme­linked immunosorbent assay. Transmission electron microscopy was used to determine the morphology of the myocardium. The rate of apoptosis was detected using TUNEL staining and flow cytometry (FCM), and the expression levels of apoptosis­related proteins were measured using western blot (WB) analysis. Moreover, H9C2 cells were treated with CKI (2 mg/ml) or LY294002 (an inhibitor of the PI3K/Akt pathway; 25 µmol/l) in combination with Ang II (1 µmol/l) for 48 h. Cell Counting Kit­8 assay, FCM and WB analysis were performed in the H9C2 cells to examine cell viability, cell cycle distribution and representative signaling proteins. It was found that CKI promoted healthy cardiac function, reduced myocardial structural damage and reduced the rate of cardiomyocyte apoptosis. CKI markedly attenuated the expression of apoptosis­related proteins in the PI3K/Akt pathway. The results of the in vitro experiments indicated that CKI promoted cardiomyocyte proliferation and inhibited apoptosis, similar to LY294002. On the whole, the present study demonstrates that CKI reduces cardiomyocyte apoptosis, promotes healthy cardiac function and attenuates Ang II­mediated HF. These ameliorative effects may be associated with the inhibition of the PI3K/Akt pathway.

Electrophysiological evaluation of an anticancer drug gemcitabine on cardiotoxicity revealing down-regulation and modification of the activation gating properties in the human rapid delayed rectifier potassium channel.

Gemcitabine is an antineoplastic drug commonly used in the treatment of several types of cancers including pancreatic cancer and non-small cell lung cancer. Although gemcitabine-induced cardiotoxicity is widely recognized, the exact mechanism of cardiac dysfunction causing arrhythmias remains unclear. The objective of this study was to electrophysiologically evaluate the proarrhythmic cardiotoxicity of gemcitabine focusing on the human rapid delayed rectifier potassium channel, hERG channel. In heterologous hERG expressing HEK293 cells (hERG-HEK cells), hERG channel current (IhERG) was reduced by gemcitabine when applied for 24 h but not immediately after the application. Gemcitabine modified the activation gating properties of the hERG channel toward the hyperpolarization direction, while inactivation, deactivation or reactivation gating properties were unaffected by gemcitabine. When gemcitabine was applied to hERG-HEK cells in combined with tunicamycin, an inhibitor of N-acetylglucosamine phosphotransferase, gemcitabine was unable to reduce IhERG or shift the activation properties toward the hyperpolarization direction. While a mannosidase I inhibitor kifunensine alone reduced IhERG and the reduction was even larger in combined with gemcitabine, kifunensine was without effect on IhERG when hERG-HEK cells were pretreated with gemcitabine for 24 h. In addition, gemcitabine down-regulated fluorescence intensity for hERG potassium channel protein in rat neonatal cardiomyocyte, although hERG mRNA was unchanged. Our results suggest the possible mechanism of arrhythmias caused by gemcitabine revealing a down-regulation of IhERG through the post-translational glycosylation disruption possibly at the early phase of hERG channel glycosylation in the endoplasmic reticulum that alters the electrical excitability of cells.

Impact of various periods of perfusion-pause and reperfusion on the severity of myocardial injury in the langenodorff model.

BACKGROUND: To explore impact of various periods of ischemia and reperfusion on the severity of myocardial injury. METHODS: Langendorff model of isolated cardiac perfusion system was established in 56 rat hearts. They were randomly assigned into four groups with four different ischemia (perfusion-pause) time and reperfusion time. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and creatine kinase-MB (CK-MB) were measured and the size of myocardial infarction was assessed by 2,3,5-triphenyltetrazolium chloride (TTC) staining. RESULTS: The levels of AST, ALT, LDH, and CK-MB in the heart tissues and perfusate were lowest in the group I (shortest time of perfusion-pause and reperfusion) followed by the groups II, III, and IV (longest time of perfusion-pause and reperfusion) (p < 0.05). The myocardial infarction size was smallest in the group I (6.63 ± 0.47) followed by group II (15.12 ± 1.03), group III (20.32 ± 2.18), and group IV (32.29 ± 5.42) (p < 0.05). Two-way ANOVA analysis revealed that period of perfusion-pause and reperfusion independently and significantly affected the levels of AST and ALT in both heart tissues and perfusate (p < 0.001). The interaction of pausing period and reperfusion significantly affected the level of AST (p = 0.046) and CK-MB (p = 0.001) in the perfusate. In addition, perfusion-pause period significantly affected levels of LDH and CK-MB only in the perfusate (p < 0.001). Neither perfusate nor heart tissue LDH level was significantly affected by the interaction of perfusion-pause and reperfusion period (p > 0.05). CONCLUSION: The severity of myocardial injury in the Langendorff model was affected by the period of perfusion-pause and reperfusion. The longer period of perfusion-pause followed by the longer the period of reperfusion, the severe myocardial injury was found.

Monocyte/High-Density Lipoprotein Ratio Is Associated with Atrial High-Rate Episodes within One Year Detected by Cardiac Implantable Electronic Devices

ABSTRACT Objective: To investigate the risk factors for predicting atrial high-rate episodes (AHREs) detected by cardiac implantable electronic devices (CIEDs). Methods: A total of 140 patients with CIED in our hospital from June 2013 to June 2018 were included and were followed up to observe whether they had AHREs. AHRE are defined as atrial rate ≥ 175 times/minute, lasting > 5 minutes, and reviewed by an experienced electrophysiologist with unclear clinical diagnosis. The patients fasted for 12 hours after implantation, and blood samples were collected for biochemical, lipid, and whole blood count detection. Follow-up was regular after discharge to record follow-up data of each patient and conduct statistical analysis. Results: One hundred and forty patients were implanted with dual-chamber pacemakers, their median age was 70 years old, 44.29% were male, 27 patients had AHRE within one year, and AHRE incidence rate was 19.29%. The microcytic to hypochromic (M/H) ratio was calculated for all AHRE patients and compared with the patients without AHRE; the M/H value of AHRE patients was significantly higher. Throughout the entire follow-up period, a total of 44 patients developed AHRE; when adjusted by multivariate analysis, only M/H ratio ≥ 4.5 vs. < 4.5 had statistical significance, and the adjusted hazard ratio value was 4.313 (1.675-11.105). Conclusion: As an indicator, M/H ratio may play an important role in the occurrence and development of atrial fibrillation and can be used as a predictor of AHRE in patients with CIED.

The Predictive Value of Epicardial Fat Tissue Volume in the Occurrence and Development of Atrial Fibrillation: A Systematic Review and Meta-Analysis.

Background: Atrial fibrillation (AF) is one of the most common arrhythmias in clinical practice. Although fat is currently considered to be a risk factor for AF and a pathogenic link between epicardial fat tissue (EFT) and AF has been speculated, there are currently few clinical studies and literature data domestically or abroad. Objective: This study conducted a meta-analysis of observational case series studies to verify the relationship between atrial fibrillation and EFT and to strengthen the predictive value of EFT in the occurrence, development, and postablative recurrence of AF. Methods: We conducted a systematic search of the literature in electronic databases until December 2021 and supplemented this through manual searches of individual studies, reviewed articles, and reference lists in conference proceedings. This study conducted a meta-analysis to compare the differences between different populations, such as healthy participants and AF patients, healthy subjects and AF subtype cases, and paroxysmal and persistent AF with AF recurrence and without AF recurrence after ablation. Results: Following the retrieval of 828 articles, only 22 articles were selected as research results. Accordingly, the meta-analysis results show that the volume of EFT in AF is greater than that in healthy subjects (MD = 39.34 ml, 95% CI = 27.11, 51.58); persistent AF is greater than paroxysmal AF (MD = 14.37 ml, 95% CI = 7.46, 21.27); and recurrence after ablation is greater than without recurrence (MD = 14.37 ml, 95% CI = 7.46, 21.27). Conclusion: The results of this study further confirm the connection between EFT and AF and that EFT has a certain predictive value for the occurrence and development of AF.

Efficacy and safety of hybutimibe in combination with atorvastatin for treatment of hypercholesteremia among patients with atherosclerotic cardiovascular disease risk equivalent: A multicenter, randomized, double-blinded phase III study.

Background: To evaluate the safety and efficacy of hybutimibe plus atorvastatin for lipid control in hypercholesterolemia patients with atherosclerotic cardiovascular disease risk equivalent. Methods: In this double-blind phase III study, we 1:1 randomly assigned 255 hypercholesterolemia patients with atherosclerotic cardiovascular disease to receive hybutimibe plus atorvastatin or placebo plus atorvastatin. The primary endpoint was the rate of change of plasma low-density lipoprotein-cholesterol (LDL-C) level at 12 weeks from baseline. The secondary endpoints were plasma total cholesterol (TC), triglyceride (TG), high-density lipoprotein-cholesterol (HDL-C), non-HDL-C, apoprotein (Apo) B, and 2-, 4-, 8-, and 12-week Apo A1 levels change rate and rates of change of plasma LDL-C levels at 2, 4, and 8 weeks from baseline. Results: From April 2016 to January 2018, 128 in the hybutimibe plus atorvastatin group and 125 in the atorvastatin group were included in modified intention-to-treat (mITT) analysis. After 12 weeks of treatment, LDL-C level changed from 2.61 mmol/L (±0.30) at baseline to 2.18 mmol/L (±0.45) in the hybutimibe plus atorvastatin group and from 2.58 (±0.31) mmol/L to 2.40 (± 0.46) mmol/L in the atorvastatin group (P < 0.0001), in mITT. The change rate in the hybutimibe plus atorvastatin group was significantly higher than that in the atorvastatin group (P < 0.0001); the estimated mean rates of change were -16.39 (95% confidence interval: -19.04, -13.74) and -6.75 (-9.48, -4.02), respectively. Consistently, in per-protocol set (PPS) analysis, the rate of change of LDL-C in the hybutimibe plus atorvastatin group was significantly higher than that in atorvastatin group. Significant decreases in the change rates of non-HDL-C, TC, and Apo B at 2, 4, 8, and 12 weeks (all P < 0.05) were observed for hybutimibe plus atorvastatin, while the differences were not significant for HDL-C, TG, and Apo-A1 (all P > 0.05). During the study period, no additional side effects were reported. Conclusions: Hybutimibe combined with atorvastatin resulted in significant improvements in LDL-C, non-HDL-C, TC, and Apo B compared with atorvastatin alone. The safety and tolerability were also acceptable, although additional benefits of hybutimibe plus atorvastatin were not observed compared with atorvastatin alone in HDL-C, TG, and Apo-A1.

miR-99a-5p: A Potential New Therapy for Atherosclerosis by Targeting mTOR and Then Inhibiting NLRP3 Inflammasome Activation and Promoting Macrophage Autophagy.

Objective: MicroRNAs have been revealed to be involved in the development of atherosclerosis. The present study is aimed at exploring the potential of miR-99a-5p as a therapy for atherosclerosis. We suspected that miR-99a-5p might inhibit NLRP3 inflammasome activation and promote macrophage autophagy via constraining mTOR, therefore, alleviating atherosclerosis. Methods: The cell viability in ox-LDL-induced THP-1 macrophages was assessed by CCK-8 assay. Bioinformatic analysis was used to predict the target genes of miR-99a-5p. The binding between miR-99a-5p and mTOR was confirmed by luciferase reporter assay. In vivo, a high-fat-diet-induced atherosclerosis model was established in apolipoprotein E knockout mice. Hematoxylin-eosin, oil red O, and Sirius red staining were performed for the determination of atherosclerotic lesions. MTOR and associated protein levels were detected by Western blot analysis. Results: miR-99a-5p inhibited NLRP3 inflammasome activation and promoted macrophage autophagy by targeting mTOR. Enforced miR-99a-5p significantly reduced the levels of inflammasome complex and inflammatory cytokines. Furthermore, miR-99a-5p overexpression inhibited the expression of mTOR, whereas mTOR overexpression reversed the trend of the above behaviors. In vivo, the specific overexpression of miR-99a-5p significantly reduced atherosclerotic lesions, accompanied by a significant downregulation of autophagy marker CD68 protein expression. Conclusion: We demonstrated for the first time that miR-99a-5p may be considered a therapy for atherosclerosis. The present study has revealed that miR-99a-5p might inhibit NLRP3 inflammasome activation and promote macrophage autophagy by targeting mTOR, therefore, alleviating atherosclerosis.