Maximakinin reversed H2O2 induced oxidative damage in rat cardiac H9c2 cells through AMPK/Akt and AMPK/ERK1/2 signaling pathways.

Maximakinin (MK), a homolog of bradykinin (BK), is extracted from skin venom of the Chinese toad Bombina maxima. Although MK has a good antihypertensive effect, its effect on myocardial cells is unclear. This study investigates the protective effect of MK on hydrogen peroxide (H2O2)-induced oxidative damage in rat cardiac H9c2 cells and explores its mechanism of action. A 3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyl Tetrazolium Bromide (MTT) assay was selected to detect the effect of MK on H9c2 cell viability, while flow cytometry was used to investigate the influence of MK and H2O2 on intracellular reactive oxygen species (ROS) levels. Protein expression changes were detected by western blot. In addition, specific protein inhibitors were applied to confirm the induction of ROS-related signaling pathways by MK. MTT assay results show that MK significantly reversed H2O2-induced cell growth inhibition. Flow cytometry Dichlorodihydrofluorescein diacetate (DCFH-DA) staining shows that MK significantly reversed H2O2-induced increases in intracellular ROS production in H9c2 cells. Moreover, the addition of specific protein inhibitors suggests that MK reverses H2O2-induced oxidative damage by activating AMP-activated protein kinase (AMPK)/protein kinase B (Akt) and AMPK/extracellular-regulated kinase 1/2 (ERK1/2) pathways. Finally, an inhibitor of bradykinin B2 receptors (B2Rs), HOE-140, was applied to investigate potential targets of MK in H9c2 cells. HOE-140 significantly blocked induction of AMPK/Akt and AMPK/ERK1/2 pathways by MK, suggesting a potentially important role for B2Rs in MK reversing H2O2-induced oxidative damage. Above all, MK protects against oxidative damage by inhibiting H2O2-induced ROS production in H9c2 cells. The protective mechanism of MK may be achieved by activation of B2Rs to activate downstream AMPK/Akt and AMPK/ERK1/2 pathways.

High-Throughput Sequencing to Investigate the Expression and Potential Role of Differentially Expressed microRNAs in Myocardial Cells after Ischemia-Reperfusion Injury.

BACKGROUND: microRNAs (miRNAs) are closely associated with the pathogenesis of various diseases, but the relationship between miRNAs and myocardial ischemia-reperfusion (I/R) injury remains unclear. Therefore, we aimed to explore the role and function of miRNAs and identify target genes regulating I/R. METHODS: We established a hypoxia/reoxygenation (H/R) model to detect differentially expressed miRNAs using high-throughput sequencing in rat myocardial cells. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were used to analyze the potential functions and signaling pathways of target genes. RESULTS: We identified 113 differentially expressed miRNAs, comprising 76 and 37 upregulated and downregulated genes, respectively. Database predictions suggested that miR-200a-3p may act through the ferroptosis pathway, and we assessed the expression of miR-200a-3p, iron ions, and ferroptosis markers. The expression of miR-200a-3p significantly increased in the H/R group, along with increased production of reactive oxygen species (ROS) and iron ions. When the expression of miR-200a-3p was inhibited, iron ions and ROS levels decreased significantly. Western blotting showed that transferrin receptor (TFRC) and Acyl-coA synthetase long-chain family member 4 (ACSL4) levels were decreased and Glutathione peroxidase 4 (GPX4) expression was increased. CONCLUSIONS: These findings offer a novel perspective on I/R regulation, and the specific mechanisms underlying the actions of miR-200a-3p merit further investigation.

Cardiospecific Troponins as Laboratory Biomarkers of Myocardial Cell Injury in Hypertension: A Mini-Review.

To date, it is well known that a significant number of diseases of cardiovascular genesis (coronary heart disease, myocardial infarction, cardiomyopathy, Takotsubo syndrome, heart failure, etc.) and extra-cardiac genesis (renal failure, chronic obstructive pulmonary disease, sepsis, diabetes mellitus, etc.) cause injury to contractile cells of the heart muscle (myocardial cells). The most sensitive and specific criteria for proving myocardial cell injury are cardiospecific troponins (CSTns) - CSTnI and CSTnT. According to the current clinical recommendations of the European, American, and Russian Cardiological Communities, CSTnI and CSTnT are the main biomarkers for early diagnosis of myocardial infarction. Hypertension is one of the most dangerous and common risk factors for the development of cardiovascular pathologies and is associated with a high risk of dangerous cardiovascular complications. Therefore, there is an urgent need to search for new biomarkers for the timely assessment of the prognosis of patients with hypertension. This mini-review aims to substantiate the possibilities of using the cardiomarkers (CSTnI and CSTnT) to assess the prognosis of patients suffering from hypertension and to discuss potential mechanisms that cause injury to myocardial cells and increase serum levels of CSTnI and CSTnT. This is a narrative mini-review, which was prepared using the following databases: Pubmed/Medline, PubMed Central, Embase, Scopus, and Web of Science. The following keywords were used in the literature search: "myocardial cells", "injury", "damage", and "hypertension" in combination with the terms "mechanisms of injury" "predictive significance", "cardiac troponins", or "cardiospecific troponins".

Quantitative Proteomics Reveals Manganese Alleviates Heat Stress of Broiler Myocardial Cells via Regulating Nucleic Acid Metabolism.

Heat stress threatens severely cardiac function by caused myocardial injury in poultry. Our previous study has showed that manganese (Mn) has a beneficial effect on heat-stress resistance of broiler. Therefore, we tried to confirm the alleviation mechanism through proteomic analysis after heat stress exposure to primary broiler myocardial cells pretreated with Mn. The experiment was divided into four groups: CON group (37 °C, cells without any treatment), HS group (43 °C, cells treatment with heat stress for 4 h), HS+MnCl2 group (cells treated with 20 µM MnCl2 before heat stress), and HS+Mn-AA group (cells treated with 20 µM Mn compound amino acid complex before heat stress). Proteome analysis using DIA identified 300 differentially expressed proteins (DEPs) between CON group and HS group; 93 and 121 DEPs were identified in inorganic manganese treatment group and organic manganese treatment group, respectively; in addition, there were 53 DEPs identified between inorganic and organic manganese group. Gene Ontology (GO) analysis showed that DEPs were mainly involved in binding, catalytic activity, response to stimulus, and metabolic process. DEPs of manganese pretreatment involved in a variety of biological regulatory pathways, and significantly influenced protein processing and repair in endoplasmic reticulum, apoptosis, and DNA replication and repair. These all seem to imply that manganese may help to resist cell damage induced by heat stress by regulating key node proteins. These findings contribute to a better understanding of the effects of manganese on overall protein changes during heat-stress and the possible mechanisms, as well as how to better use manganese to protect heart function in high temperature.

Mechanism of Ferroptosis in Myocardial Cells and Protective Effect of Traditional Chinese Medicine / 中国实验方剂学杂志

Ferroptosis is a new type of programmed cell death， characterized by iron overload and lipid peroxidation. Cardiovascular disease （CVD） is an ischemic or hemorrhagic disease of the heart caused by various factors， mainly including myocardial infarction， heart failure， etc. Ferroptosis is involved in the process of myocardial cell damage and plays a driving role in the progression of various CVDs. Its main mechanisms include the destruction of iron homeostasis， the production of reactive oxygen species， the disorder of the antioxidant system， mitochondrial membrane damage， endoplasmic reticulum stress， tumor suppressor gene p53， transcription factor Nrf2 pathway， etc. Myocardial injury is one of the causes of death in many patients with heart disease. Monomers or compounds of traditional Chinese medicine have shown good effects in the treatment of myocardial cell injury caused by ferroptosis， including baicalin protecting cardiac microvascular endothelial cells of myocardial ischemia-reperfusion （I/R） rats through intracellular phosphatidylinositol kinase/phosphokinase B/endothelial nitric oxide synthase （PI3K/Akt/eNOS） pathway， Aralia elata saponin inhibiting myocardial cell ferroptosis through glucocorticoid receptor/p53/solute carrier family 7 members 11 （NR3C1/p53/SLC7A11） pathway， Xinyang tablets improving oxidative stress by regulating phosphorylated serine/threonine protein kinase/stress-activated protein kinase/p53 （MLK3/JNK/p53） signaling pathway. It is of great significance to explore the mechanism of ferroptosis and the protective effect of related traditional Chinese medicine after myocardial cell injury. This article reviews the mechanism of ferroptosis and its relationship with myocardial cells， as well as traditional Chinese medicine monomers and formulas for treating CVDs through the ferroptosis pathway. The article focuses on the pathways and effects of traditional Chinese medicine treatment， so as to provide a reference for the treatment of CVDs with traditional Chinese medicine.

Toxic effects of bisphenol S on mice heart and human umbilical cord endothelial cells.

Bisphenol S (BPS) exerts toxic effects on hippocampal HT22 cells, endocrine secretion, and reproductive capacity. However, whether BPS exerts toxic effects on the heart requires further investigation. Therefore, we investigated the effects of BPS on mouse heart tissues and predicted possible underlying molecular mechanisms of action. Our study showed that BPS induced apoptosis, increased oxidative stress response. Using electron microscopy, we found that BPS disrupted sarcomere arrangement in myocardial cells and caused reduction in the number of plasmalemmal vesicles in endothelial cells in the mouse heart tissues. Also, BPS increased expression levels of P-NF-κB in mouse heart tissues. Furthermore, we found that BPS induced reactive oxygen species (ROS) generation, NF-κB activation, promoted apoptosis, elevated expression of BAX and Caspase 3, and decreased expression of Bcl-2 in H9c2 cells and HUVECs. However, after the addition of n-acetylcysteine or pyrrolidinedithiocarbamate, ROS generation, NF-κB activation, apoptosis, and expression of BAX and Caspase 3 were reduced, whereas expression of Bcl-2 was elevated. Our results demonstrated that BPS induced apoptosis of myocardial and endothelial cells through oxidative stress by activation of NF-κB signaling pathway.

Fullerene [60] encapsulated water-soluble supramolecular cage for prevention of oxidative stress-induced myocardial injury.

A water-soluble cube-like supramolecular cage was constructed by an engagement of six molecules through a hydrophobic effect in the water. The obtained cage could perfectly encapsulate one fullerene C60 molecule inside of the cavity and significantly improve the water-solubility of the C60 without changing the original structure. The water-soluble complex was further applied to reduce the reactive oxygen species (R.O.S.) in cardiomyocytes (FMC84) through Akt/Nrf2/HO-1 pathway. Furthermore, in the mouse model of myocardial ischemia-reperfusion injury, the application of C60 was found to be effective in reducing myocardial injury and improving cardiac function. It also reduced the levels of R.O.S. in myocardial tissue, inhibited myocardial apoptosis, and mitigated myocardial inflammatory responses. The present study provides a new guideline for constructing water-soluble C60 and verifies the important role of C60 in preventing oxidative stress-related cardiovascular disease injury.

[Effect of Wenyang Zhenshuai Granules on autophagy and apoptosis of myocardial cells in septic rats via regulating miR-132-3p/UCP2 expression].

This study aimed to investigate the effect of Wenyang Zhenshuai Granules(WYZSG) on autophagy and apoptosis of myocardial cells in rats with sepsis via regulating the expression of microRNA-132-3p(miR-132-3p)/uncoupling protein 2(UCP2). Sixty SD rats were randomly divided into modeling group(n=50) and sham operation group(n=10). The sepsis rat model was constructed by cecal ligation and perforation in the modeling group. The successfully modeled rats were randomly divided into WYZSG low-, medium-and high-dose groups, model group and positive control group. Rats in the sham operation group underwent opening and cecum division but without perforation and ligation. Hematoxylin-eosin(HE) staining was used to observe the pathological changes of rat myocardial tissue. Myocardial cell apoptosis was detected by TdT-mediated dUTP nick end labeling(TUNEL) assay. Real-time quantitative polymerase chain reaction(RT-qPCR) was performed to detect the expression of miR-132-3p and the mRNA expressions of UCP2, microtubule-associated protein light chain 3(LC3-Ⅱ/LC3-Ⅰ), Beclin-1 and caspase-3 in rat myocardial tissue. The protein expressions of UCP2, LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 in myocardial tissue were detected by Western blot. Dual luciferase reporter assay was used to verify the regulatory relationship between miR-132-3p and UCP2. The myocardial fibers of sepsis model rats were disordered, and there were obvious inflammatory cell infiltration as well as myocardial cell edema and necrosis. With the increase of the WYZSG dose, the histopathological changes of myocardium were improved to varying degrees. Compared with the conditions in the sham operation group, the survival rate and left ventricular ejection fraction(LVEF) of rats in the model group, positive control group and WYZSG low-, medium-and high-dose groups were decreased, and the myocardial injury score and apoptosis rate were increased. Compared with the model group, the positive control group and WYZSG low-, medium-and high-dose groups had elevated survival rate and LVEF, and lowered myocardial injury score and apoptosis rate. The expression of miR-132-3p and the mRNA and protein expressions of UCP2 in myocardial tissue in the model group, positive control group and WYZSG low-, medium-and high-dose groups were lower, while the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 were higher than those in the sham operation group. Compared with model group, the positive control group and the WYZSG low-, medium-and high-dose groups had an up-regulation in the expression of miR-132-3p and the mRNA and protein expressions of UCP2, while a down-regulation in the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3. WYZSG inhibited excessive autophagy and apoptosis of myocardial cells in septic rats and improved myocardial injury, possibly by regulating the expression of miR-132-3p/UCP2.

Klotho protects against aged myocardial cells by attenuating ferroptosis.

Klotho (KL) is a renal protein with aging-suppression properties that mediates its regulatory effect during cardiac fibroblast aging. However, to determine whether KL can protect aged myocardial cells by attenuating ferroptosis, this study aimed to investigate the protective effect of KL on aged cells and to explore its potential mechanism. Cell injury of H9C2 cells was induced with D-galactose (D-gal) and treated with KL in vitro. This study demonstrated that D-gal induces aging in H9C2 cells. D-gal treatment increased ß-GAL(ß-galactosidase) activity, decreased cell viability, enhanced oxidative stress, reduced mitochondrial cristae, and decreased the expression of solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase-4 (GPx4), and P53, which are primary regulators of ferroptosis. The results showed that KL can eliminate D-gal-induced aging in H9C2 cells, likely due to its ability to increase the expression of the ferroptosis-associated proteins SLC7A11 and GPx4. Moreover, pifithrin-α, a P53-specific inhibitor, enhanced the expression of SLC7A11 and GPx4. These results suggest that KL may be involved in D-gal-induced H9C2 cellular aging during ferroptosis, mainly through the P53/SLC7A11/GPx4 signaling pathway.

A quantitative proteomic analyses of primary myocardial cell injury induced by heat stress in chicken embryo.

In this study, the model of heat stress was constructed in primary chick embryonic myocardial cells at 42 °C for 4 h. Proteome analysis using DIA identified 245 differentially expressed proteins (DEPs) (Q-value <0.05, fold change >1.5), of which 63 proteins were up-regulated and 182 proteins were down-regulated. Many were related to metabolism, oxidative stress, oxidative phosphorylation and apoptosis. Gene Ontology (GO) analysis showed that many DEPs under heat stress were involved in regulating metabolites and energy, cellular respiration, catalytic activity and stimulation. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEPs were enriched in metabolic pathways, oxidative phosphorylation, citrate cycle (TCA cycle), cardiac muscle contraction, and carbon metabolism. The results could help understanding of the effect of heat stress on myocardial cells and even the heart and possible action mechanism at the protein level.

Plantamajoside alleviates hypoxia-reoxygenation injury through integrin-linked kinase/c-Src/Akt and the mitochondrial apoptosis signaling pathways in H9c2 myocardial cells.

Myocardial ischemia-reperfusion injury(MIRI) is one of the common complications after myocardial infarction surgery, Oxidative stress is among the main mechanisms of myocardial ischemia-reperfusion injury. Plantamajoside (PMS), the main effective ingredient in the genus Plantain, has been reported to possess an antioxidation, anti-inflammatory and anti-apoptosis role. However, whether PMS can attenuate myocardial ischemia-reperfusion injury is not yet known. Herein, we explored the effects of PMS on hypoxia-reoxygenation (H/R) injury in H9c2 cardiomyocytes and the underling molecular mechanisms of the treatment. Network pharmacological analysis screened the top 31 key genes in the treatment of MIRI disease treated with PMS, and the result of molecular docking further illustrated the roles that the PMS play in the treatment of MIRI through its interference with integrin-linked kinase (ILK) target protein. PMS was not cytotoxic in the concentration range of 5-40 µM and increased cell survival after H/R injury in a concentration-dependent manner without affecting proliferation or growth. PMS significantly reduced the levels of lactate dehydrogenase, malonic dialdehyde, reactive oxygen species and cell apoptosis, and increased soperoxide dismutase activity compared with those of the H/R injury group. PMS promoted the protein and mRNA expression of ILK and Bcl-2, the protein expression of p-Akt, and reduced the protein and mRNA expression of Bax, Caspase-3, and Cytochrome c, the protein expression of p-c-Src. PMS has protective effects against H/R injury in H9c2 cells, and its protective mechanism may be related to reactive oxygen species clearance, activation of the ILK/c-Src/Akt pathway and inhibition of the mitochondrial apoptosis.

Hsp90 protected chicken primary myocardial cells from heat-stress injury by inhibiting oxidative stress and calcium overload in mitochondria.

Severe heat stress can cause human and animal heart failure and sudden death, which is an important issue of public health worldwide. Our previous studies in animals showed that myocardial cells injury was critical in the above process, and Hsp90 induction has a definite anti-myocardial injury effect, especially through aspirin (ASA). But the mechanism has not been fully clarified. In this study, an in vitro heat stress model of chicken primary myocardial cells (CPMCs) most sensitive to heat stress was used to explore the cell injuries and corresponding molecular resistance mechanism. We found that heat stress resulted in serious oxidation stress and calcium overload in mitochondria, which destroyed the mitochondrial structure and function and then triggered the cell death mechanism of CPMCs. Hsp90 was proven to be a central regulator for resisting heat-stress injury in CPMCs mitochondria using its inhibitor and inducer (geldanamycin and ASA), respectively. The mechanism involved that Hsp90 could activate Akt and PKM2 signals to promote Bcl-2 translocation into mitochondria and its phosphorylation, thereby preventing ROS production and subsequent cell apoptosis. In addition, Hsp90 inhibited mitochondrial calcium overload to overcome MPTP opening and MMP suppression through the inhibitory effect of Raf-1-ERK activation on the CREB-IP3R pathway. This study is the first to reveal a pivotal reason for heat-stressed damage in chicken myocardial cells at subcellular level and identify an effective regulator, Hsp90, and its protective mechanisms responsible for maintaining mitochondrial homeostasis.

Effect of Wenyang Zhenshuai Granules on autophagy and apoptosis of myocardial cells in septic rats via regulating miR-132-3p/UCP2 expression / 中国中药杂志

This study aimed to investigate the effect of Wenyang Zhenshuai Granules(WYZSG) on autophagy and apoptosis of myocardial cells in rats with sepsis via regulating the expression of microRNA-132-3p(miR-132-3p)/uncoupling protein 2(UCP2). Sixty SD rats were randomly divided into modeling group(n=50) and sham operation group(n=10). The sepsis rat model was constructed by cecal ligation and perforation in the modeling group. The successfully modeled rats were randomly divided into WYZSG low-, medium-and high-dose groups, model group and positive control group. Rats in the sham operation group underwent opening and cecum division but without perforation and ligation. Hematoxylin-eosin(HE) staining was used to observe the pathological changes of rat myocardial tissue. Myocardial cell apoptosis was detected by TdT-mediated dUTP nick end labeling(TUNEL) assay. Real-time quantitative polymerase chain reaction(RT-qPCR) was performed to detect the expression of miR-132-3p and the mRNA expressions of UCP2, microtubule-associated protein light chain 3(LC3-Ⅱ/LC3-Ⅰ), Beclin-1 and caspase-3 in rat myocardial tissue. The protein expressions of UCP2, LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 in myocardial tissue were detected by Western blot. Dual luciferase reporter assay was used to verify the regulatory relationship between miR-132-3p and UCP2. The myocardial fibers of sepsis model rats were disordered, and there were obvious inflammatory cell infiltration as well as myocardial cell edema and necrosis. With the increase of the WYZSG dose, the histopathological changes of myocardium were improved to varying degrees. Compared with the conditions in the sham operation group, the survival rate and left ventricular ejection fraction(LVEF) of rats in the model group, positive control group and WYZSG low-, medium-and high-dose groups were decreased, and the myocardial injury score and apoptosis rate were increased. Compared with the model group, the positive control group and WYZSG low-, medium-and high-dose groups had elevated survival rate and LVEF, and lowered myocardial injury score and apoptosis rate. The expression of miR-132-3p and the mRNA and protein expressions of UCP2 in myocardial tissue in the model group, positive control group and WYZSG low-, medium-and high-dose groups were lower, while the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3 were higher than those in the sham operation group. Compared with model group, the positive control group and the WYZSG low-, medium-and high-dose groups had an up-regulation in the expression of miR-132-3p and the mRNA and protein expressions of UCP2, while a down-regulation in the mRNA and protein expressions of LC3-Ⅱ/LC3-Ⅰ, Beclin-1 and caspase-3. WYZSG inhibited excessive autophagy and apoptosis of myocardial cells in septic rats and improved myocardial injury, possibly by regulating the expression of miR-132-3p/UCP2.

[Effect and mechanism of Poria cocos polysaccharides on myocardial cell apoptosis in rats with myocardial ischemia-reperfusion injury by regulating Rho-ROCK signaling pathway].

This study aimed to investigate the effect and underlying mechanism of Poria cocos polysaccharides(PCP) on myocardial cell apoptosis in the rat model of myocardial ischemia-reperfusion injury(MI/RI). Male SPF-grade SD rats were randomly divided into a sham group(saline), a model group(saline), low-and high-dose PCP groups(100 and 200 mg·kg~(-1)), and a fasudil group(10 mg·kg~(-1)), with 16 rats in each group. Except for the sham group, the other four groups underwent left anterior descending coronary artery ligation for 30 min followed by reperfusion for 2 h to establish the MI/RI model. The myocardial infarct area was assessed by TTC staining. Histological changes were observed through HE staining. Myocardial cell apoptosis was evaluated using TUNEL staining. Serum lactate dehydrogenase(LDH), creatine kinase MB(CK-MB), interleukin-1ß(IL-1ß) and IL-18 levels, myocardial superoxide dismutase(SOD) activity and malondialdehyde(MDA) levels were detected by ELISA. Protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2 associated X protein(Bax), cleaved caspase-3, Ras homolog gene A(RhoA), myosin phosphatase target subunit 1(MYPT-1), phosphorylated MYPT-1(p-MYPT-1), and Rho-associated coiled-coil forming kinase 1(ROCK 1) were measured by Western blot. Pathological staining of myocardial tissue revealed that in the model group, there was focal necrosis of myocardial tissue, myocardial cell swelling, unclear boundaries, and neutrophil infiltration. These pathological changes were alleviated in the low-and high-dose PCP groups and the fasudil group. Compared with the model group, the low-and high-dose PCP groups and the fasudil group showed significantly reduced myocardial infarct area and myocardial cell apoptosis rate. Compared with the sham group, the model group exhibited elevated serum LDH, CK-MB, IL-1ß and IL-18 levels, increased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and decreased myocardial SOD levels and Bcl-2 protein expression. Compared with the model group, the PCP groups and the fasudil group showed lowered serum LDH, CK-MB, IL-1ß and IL-18 levels, decreased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and increased myocardial SOD levels and Bcl-2 protein expression. PCP exhibited a certain preventive effect on myocardial tissue pathological damage and myocardial cell apoptosis in MI/RI rats, possibly related to the inhibition of the Rho-ROCK signaling pathway activation, thereby reducing oxidative stress and inflammatory responses.

Effect and mechanism of Poria cocos polysaccharides on myocardial cell apoptosis in rats with myocardial ischemia-reperfusion injury by regulating Rho-ROCK signaling pathway / 中国中药杂志

This study aimed to investigate the effect and underlying mechanism of Poria cocos polysaccharides(PCP) on myocardial cell apoptosis in the rat model of myocardial ischemia-reperfusion injury(MI/RI). Male SPF-grade SD rats were randomly divided into a sham group(saline), a model group(saline), low-and high-dose PCP groups(100 and 200 mg·kg~(-1)), and a fasudil group(10 mg·kg~(-1)), with 16 rats in each group. Except for the sham group, the other four groups underwent left anterior descending coronary artery ligation for 30 min followed by reperfusion for 2 h to establish the MI/RI model. The myocardial infarct area was assessed by TTC staining. Histological changes were observed through HE staining. Myocardial cell apoptosis was evaluated using TUNEL staining. Serum lactate dehydrogenase(LDH), creatine kinase MB(CK-MB), interleukin-1β(IL-1β) and IL-18 levels, myocardial superoxide dismutase(SOD) activity and malondialdehyde(MDA) levels were detected by ELISA. Protein expression of B-cell lymphoma 2(Bcl-2), Bcl-2 associated X protein(Bax), cleaved caspase-3, Ras homolog gene A(RhoA), myosin phosphatase target subunit 1(MYPT-1), phosphorylated MYPT-1(p-MYPT-1), and Rho-associated coiled-coil forming kinase 1(ROCK 1) were measured by Western blot. Pathological staining of myocardial tissue revealed that in the model group, there was focal necrosis of myocardial tissue, myocardial cell swelling, unclear boundaries, and neutrophil infiltration. These pathological changes were alleviated in the low-and high-dose PCP groups and the fasudil group. Compared with the model group, the low-and high-dose PCP groups and the fasudil group showed significantly reduced myocardial infarct area and myocardial cell apoptosis rate. Compared with the sham group, the model group exhibited elevated serum LDH, CK-MB, IL-1β and IL-18 levels, increased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and decreased myocardial SOD levels and Bcl-2 protein expression. Compared with the model group, the PCP groups and the fasudil group showed lowered serum LDH, CK-MB, IL-1β and IL-18 levels, decreased MDA levels, relative protein expression of Bax, cleaved caspase-3, RhoA, ROCK1 and p-MYPT-1, and increased myocardial SOD levels and Bcl-2 protein expression. PCP exhibited a certain preventive effect on myocardial tissue pathological damage and myocardial cell apoptosis in MI/RI rats, possibly related to the inhibition of the Rho-ROCK signaling pathway activation, thereby reducing oxidative stress and inflammatory responses.

Hypertension as One of the Main Non-Myocardial Infarction-Related Causes of Increased Cardiospecific Troponins: From Mechanisms to Significance in Current Medical Practice.

It is well known that many pathological conditions of both cardiovascular diseases (CVDs) (coronary heart disease, myocardial infarction, arrhythmias, myocarditis, cardiomyopathy, etc.) and non-cardiac (sepsis, anemia, kidney diseases, diabetes mellitus, etc.) origin in the course of their development cause injury to contractile cardiac muscle cells - myocardial cells (MCs). One of the most sensitive and specific criteria for detecting MC injury are cardiospecific troponins (CTs), which are regulatory protein molecules that are released into the blood serum from MC upon their death or injury. Current methods for determining CTs are called high-sensitive ones, and their main advantage is a very low minimum detectable concentration (limit of detection) (average 1 - 10 ng/L or less), which allows early detection of minor MC injury at the earliest stages of CVDs, and therefore they can change the understanding of disease development mechanisms and open up new diagnostic possibilities. One of the most common and dangerous early diseases of the cardiovascular system is hypertension (HT). The novelty of this article lies in the discussion of a new diagnostic direction - predicting the risk of developing CVDs and their dangerous complications in patients with HT by determining the concentration of CTs. In addition, pathophysiological mechanisms underlying MC injury and the release of CTs into the bloodstream and the elimination of CTs into the urine are proposed. This information will contribute to additional fundamental and clinical research to verify the new diagnostic possibility of using CTs in clinical practice (for the management of patients with HT).

Protective Effect of Ginsenosides Rg1 on Ischemic Injury of Cardiomyocytes After Acute Myocardial Infarction.

Acute myocardial infarction (AMI) leads to anoxia and ischemia of cardiomyocytes, followed by apoptosis. This study investigated the protective effect of ginsenoside Rg1 (Rg1) on myocardial ischemia injury in rats with AMI. Rats were randomly divided into five groups: group A (blank control group), group B (hypoxia/reoxygenation group), group C (hypoxia/reoxygenation + 10 mg/L Rg1), group D (hypoxia/reoxygenation + 20 mg/L Rg1) and group E (hypoxia/reoxygenation + 40 mg/L Rg1). The survival rate, apoptosis rate, expression of cyclin-dependent kinase 4 (CDK4), fibroblast growth factor 9 (FGF9), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), microvessel density and myocardial infarction area of rats in each group were compared. The expressions of CDK4 and FGF9, the contents of SOD and GSH-Px in groups C, D and E injected with Rg1 were significantly promoted compared to group B without Rg1 injection (P < 0.05). The survival rate of myocardial cells was significantly increased while the apoptosis rate was significantly decreased in group C, D, E compared to group B (P < 0.05). On the 3rd, 7th and 10th day following Rg1 treatment, the infarct area of E group was significantly decreased in three groups C, D, E, and the microvessel density of infarct area was significantly increased compared with group B (P < 0.05). So, Rg1 can improve the survival rate of myocardial cells, reduce the apoptosis rate and the area of myocardial infarction, and increase the microvessel density of infarct area, thus playing a protective role in ischemic myocardial cells of AMI rats.

FUN14 Domain Containing 1 (FUNDC1): A Promising Mitophagy Receptor Regulating Mitochondrial Homeostasis in Cardiovascular Diseases.

Mitochondria, the intracellular organelles for cellular aerobic respiration and energy production, play an important role in the regulation of cell metabolism and cell fate. Mitophagy, a selective form of autophagy, maintains dynamic homeostasis of cells through targeting long-lived or defective mitochondria for timely clearance and recycling. Dysfunction in mitophagy is involved in the molecular mechanism responsible for the onset and development of human diseases. FUN14 domain containing 1 (FUNDC1) is a mitochondrial receptor located in the outer mitochondria membrane (OMM) to govern mitophagy process. Emerging evidence has demonstrated that levels and phosphorylation states of FUNDC1 are closely related to the occurrence, progression and prognosis of cardiovascular diseases, indicating a novel role for this mitophagy receptor in the regulation of mitochondrial homeostasis in cardiovascular system. Here we review mitophagy mediated by FUNDC1 in mitochondria and its role in various forms of cardiovascular diseases.

Porcine Circovirus type 2 infected myocardial tissue transcriptome signature.

The goal of this study was to compare the global gene expression profile in cardiac tissues of pig infected with porcine circovirus 2 (PCV2) to that of healthy cells. Since PCV2 infection causes severe cardiovascular lesions, the myocardial tissue model was chosen for this study. In High-throughput transcriptome analysis, DESeq2 and CLC genomics workbench analyses revealed a total of 196 significantly differentially expressed genes (DEGs) (p-value < 0.05). Furthermore, 194 transcripts were upregulated, while only two were downregulated (HSPA6 and DNAJA1), with fold changes ranging from 16.293 to -10.002. Among the KEGG canonical pathways targeted by the DEGs in the functional analysis, adrenergic signalling in cardiomyocytes, Cardiac Muscle Contraction, Hypertrophic Cardiomyopathy (HCM), and Dilated Cardiomyopathy (DCM) tends to be enriched. The differentially expressed highly connected (DEHC) biomarker genes in pathogenicity of PCV2 infection, such as LDB3, MYOZ2, CASQ2, TNNT2, MLC2V, MYBPC3, ACTC1, TCAP, TNNI3, TRDN, CSRP3, MYL3, RYR2, LMOD2, MYH7, etc., were identified using protein-protein interaction (PPI) network analysis. The study might provide detailed information on the dysregulated genes and biological pathways in infected myocardial tissues that may be essential for PCV2-related heart pathology.

Alleviation of Myocardial Inflammation in Diabetic Rats by Flavonoid Extract of Helichrysum Arenarium and Its Effect on Damaged Myocardial Cells Induced by High Glucose.

Objective: To investigate the effects of helichrysum arenarium flavonoid extract on high glucose damaged cardiomyocytes and the alleviation of myocardial inflammation in diabetic rats. Methods: The study was divided into two parts, the first part was a cellular experiment in which a high-glucose cardiomyocyte injury model (H9C2) was established using a high-glucose culture medium, divided into low (group N1, 6.25 µg/mL), medium (group N2, 12.5 µg/mL), high dose group (group N3, 25 µg/mL) of helichrysum arenarium intervention and a model control group. The levels of enzyme activities [creatine kinase (CK) and lactate dehydrogenase (LDH)] in each group of H9c2 cells were measured by Enzyme-linked immunosorbent assay (ELISA), the expression levels of apoptotic proteins (Bax and Bcl-2) by western blot (WB), and the expression levels of inflammatory factors [tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6)] by RT-qPCR. The second part is animal experiments, after establishing the diabetic rat model, we used helichrysum arenarium flavonoid extract to intervene SD rats, divided into helichrysum arenarium intervention low (group S1, 250 mg/kg), medium (group S2, 500 mg/kg), high dose group (group S3, 1 g/kg), SD rat model group. Hematoxylin-eosin (HE) staining was used to observe myocardial tissue lesions, and Real Time Quantitative PCR (RT-qPCR) method was used to detect inflammatory (TNF-α, IL-1ß, and IL-6) infiltration in myocardial tissue. Results: Cellular experiments: The activity levels of enzymes such as CK and LDH and the levels of inflammatory factors such as TNF-α, IL-1ß, and IL-6 in damaged cardiac myocytes were significantly decreased after helichrysum arenarium intervention; the expression levels of Bax protein were significantly down-regulated and the expression levels of Bcl-2 protein expression were significantly up-regulated. Animal experiment: HE staining showed that the model group had widened intercellular spaces, interstitial edema and obvious inflammatory cell infiltration in cardiac muscle tissue. After the intervention of helichrysum arenarium, the collagen fibers of rat myocardial cells were significantly reduced and cell degeneration was alleviated. Animal experiment: HE staining showed that the model group had widened intercellular spaces, interstitial edema and obvious inflammatory cell infiltration in cardiac muscle tissue. After the intervention of helichrysum arenarium, the collagen fibers of rat myocardial cells were significantly reduced and cell degeneration was alleviated; the levels of TNF-α, IL-1ß, IL-6 and other inflammatory factors in myocardial tissues were significantly decreased. Conclusion: The helichrysum arenarium flavonoid extract can reduce the degree of damage of H9C2 cells induced by high glucose and decrease the cellular inflammatory response, and its mechanism of action may be achieved by regulating the apoptotic factors Bax and Bcl-2. In addition, the extract of helichrysum arenarium can reduce the histopathological damage of myocardium in diabetic rats, decrease the inflammatory response in the tissue, and achieve the effect of myocardial protection.