p27 kip1 haplo-insufficiency improves cardiac function in early-stages of myocardial infarction by protecting myocardium and increasing angiogenesis by promoting IKK activation

The Efficacy and Safety of Bisoprolol in the Treatment of Myocardial Infarction with Cardiac Insufficiency

Background

Bisoprolol is commonly used to treat moderate or severe chronic stable heart failure, coronary heart disease, and hypertension. This study is aimed at analyzing the efficacy of bisoprolol in the treatment of myocardial infarction with cardiac insufficiency and its effect on cardiac function, Hcy, and CRP through meta-analysis.

Methods

A total of 120 patients with myocardial infarction and cardiac insufficiency from February 2020 to February 2021 were selected and randomly divided into two groups (control and the observation, n = 60) according to the random number table method. The control group was given conventional treatment. The observation group was given bisoprolol on the basis of control group. The clinical efficacy, systolic blood pressure, diastolic blood pressure, heart rate, cardiac function indexes, homocysteine (Hcy), and C-reactive protein (CRP) levels were compared between the two groups before and after treatment through data analysis. Adverse reactions were observed during treatment.

Results

Compared with the control group, the total effective rate of the observation group was significantly increased (p < 0.05). After treatment, the levels of heart rate, left ventricular end-diastolic volume (LVEDV), and left ventricular end-systolic volume (LVESV) and serum Hcy and CRP levels in the observation group were significantly lower than those in the control group (p < 0.05). Meanwhile, left ventricular ejection fraction (LVEF) level in the observation group after treatment was higher than that of the control group (p < 0.05).

Conclusion

Bisoprolol combined with conventional treatment can reduce serum Hcy and CRP levels in patients with myocardial infarction and cardiac insufficiency and improve cardiac function. Moreover, there are no obvious adverse reactions during the treatment.

P27 Protects Neurons from Ischemic Damage by Suppressing Oxidative Stress and Increasing Autophagy in the Hippocampus

p27^Kip1 (p27), a well-known cell regulator, is involved in the regulation of cell death and survival. In the present study, we observed the effects of p27 against oxidative stress induced by H₂O₂ in HT22 cells and transient ischemia in gerbils. Tat (trans-acting activator of transcription) peptide and p27 fusion proteins were prepared to facilitate delivery into cells and across the blood-brain barrier. The tat-p27 fusion protein, rather than its control protein Control-p27, was delivered intracellularly in a concentration and incubation time-dependent manner and showed its activity in HT22 cells. The localization of the delivered Tat-p27 protein was also confirmted in the HT22 cells and hippocampus in gerbils. In addition, the optimal concentration (5 μM) of Tat-p27 was determined to protect neurons from cell death induced by 1 mM H₂O₂. Treatment with 5 μM Tat-p27 significantly ameliorated H₂O₂-induced DNA fragmentation and the formation of reactive oxygen species (ROS) in HT22 cells. Tat-p27 significantly mitigated the increase in locomotor activity a day after ischemia and neuronal damage in the hippocampal CA1 region. It also reduced the ischemia-induced membrane phospholipids and ROS formation. In addition, Tat-p27 significantly increased microtubule-associated protein 1A/1B light chain 3A/3B expression and ameliorated the H₂O₂ or ischemia-induced increases of p62 and decreases of beclin-1 in the HT22 cells and hippocampus. These results suggest that Tat-p27 protects neurons from oxidative or ischemic damage by reducing ROS-induced damage and by facilitating the formation of autophagosomes in hippocampal cells.

p27kip1 haploinsufficiency preserves myocardial function in the early stages of myocardial infarction via Atg5‑mediated autophagy flux restoration

Myocardial infarction (MI) is a leading cause of mortality in adults worldwide. Over the last two decades, gene therapy has been a hot topic in cardiology, and there has been a focus on cell cycle inhibitors and their protective effects on the myocardium post-MI. In our previous study, the haploinsufficiency of p27^kip1 (p27) was demonstrated to improve cardiac function in mice post-MI by promoting angiogenesis and myocardium protection through the secretion of growth factors. Autophagy is an adaptive response of cells to environmental changes, such as nutrient deprivation, ischemia and hypoxia. The appropriate regulation of autophagy may improve myocardial function by preventing apoptosis of cardiomyocytes. In this study, we used immunoassays, transmission electron microscopy and cardiac ultrasound to confirm that p27 haploinsufficiency prevents myocardial apoptosis by restoring autophagy protein 5-mediated autophagy flux in the early stages of MI. The present study provides a novel method for studying MI or ischemic heart disease therapy.

Treatment of Critical Limb Ischemia by pIRES/VEGF165/HGF Administration

BACKGROUND

Prognosis of peripheral artery disease (PAD), especially critical limb ischemia (CLI), is very poor despite the development of endovascular therapy and bypass surgery. Many patients result in having leg amputation. We decided to investigate the safety and efficacy of plasmid of internal ribosome entry site/vascular endothelial growth factor (VEGF) 165/hepatocyte growth factor (HGF) gene therapy (GT) in patients suffered from CLI.

METHODS

Administration of plasmid of internal ribosome entry site/VEGF165/HGF was performed in 12 limbs of 12 patients with rest pain and ischemic ulcers due to CLI. Plasmid was injected into the muscles of the ischemic limbs. The levels of VEGF in serum and the ankle-brachial index (ABI) were measured before and after treatment.

RESULTS

Mean (±SD) plasma levels of VEGF increased nonsignificantly from 258 ± 81 pg/L to 489 ± 96 pg/L (P > 0.05) 2 weeks after therapy, and the ABI improved significantly from 0.27 ± 0.20 to 0.50 ± 0.22 (P < 0.001) 3 months after therapy. Ischemic ulcers healed in 9 limbs. Amputation was performed in 3 patients because of advanced necrosis and wound infection. However, the level of amputations was lowered below knee in these cases. Complications were limited to transient leg edema in 3 patients and fever in 2 patients.

CONCLUSIONS

Intramuscular administration of plasmid of internal ribosome entry site/VEGF165/HGF is safe, feasible, and effective for patients with critical leg ischemia.

Loss of p27kip1 suppresses the myocardial senescence caused by estrogen deficiency

Estrogen deficiency accelerates the aging process and increases the risk of developing cardiovascular disease (CVD). Apoptosis is one of the important mechanisms of aging. p27^kip1 is a cyclin-dependent kinase inhibitor that can regulate cell cycle, apoptosis, and cell motility. p27^kip1 overexpression can inhibit cell cycle and increase apoptosis so it has been considered as a marker of aging. In the present study, bilateral ovariectomy (OVX) was performed as a model for menopause in wild-type (WT) and p27^kip1 knockout (KO) mice to assess the effects of p27^kip1 loss in myocardial aging caused by estrogen deficiency. We found that myocardial fibrosis and heart weight/body weight ratio of mice in the OVX group and p27^kip1 KO group were significantly increased. Echocardiography showed that the left ventricular diameter and volume of the WT OVX group increased significantly and the cardiac function decreased. However, there was no significant difference in the results of echocardiography between the two p27^kip1 KO groups. The aging and apoptosis indexes in OVX group were increased significantly, However, the indexes in p27^kip1 KO mice were decreased. The expression of antioxidant indexes in OVX group was decreased significantly and p27^kip1 KO can improve the antioxidant ability. These results provided that estrogen deficiency increased oxidative stress and apoptosis, accelerated aging of heart. p27^kip1 KO can partly delay the aging and apoptosis of heart through upregulated antioxidant enzymes.

Naloxone attenuates ischemic brain injury in rats through suppressing the NIK/IKKα/NF-κB and neuronal apoptotic pathways

Although naloxone has been documented to exert neuroprotection in animal model of cerebral ischemia, the mechanism is not well understood. In this present study we investigated whether naloxone affected the mitochondrial apoptotic pathway in ischemic brain injury of rats. SD rats were subjected to a permanent middle cerebral artery occlusion surgery, and received naloxone (0.5, 1, 2 mg/kg, i.v.) immediately after ischemia. Neurological deficits were evaluated 24 h after ischemia using the McGraw Stroke Index, and then the rats were killed, and the brains were collected for further analyses. We show that naloxone treatment dose-dependently decreased the infarction volume and morphological injury, improved motor behavioral function, and markedly curtailed brain edema. Furthermore, naloxone administration significantly inhibited the nuclear translocation of NF-κB p65 and decreased the levels of nuclear NF-κB p65 in the ischemic penumbra. Naloxone administration also dose-dependently increased the NF-κB inhibitory protein (IκBα) levels and attenuated phosphorylated NIK and IKKα levels in the ischemic penumbra. In addition, naloxone administration dose-dependently increased Bcl-2 levels, decreased Bax levels, stabilized the mitochondrial transmembrane potential, and inhibited cytochrome c release and caspase 3 and caspase 9 activation. These results indicate that the neuroprotective effects of naloxone against ischemic brain injury involve the inhibition of NF-κB activation via the suppression of the NIK/IKKα/IκBα pathway and the obstruction of the mitochondrial apoptotic pathway in neurons.

Hypoxia-Inducible Factor 1 alpha (HIF-1α)/Vascular Endothelial Growth Factor (VEGF) Pathway Participates in Angiogenesis of Myocardial Infarction in Muscone-Treated Mice: Preliminary Study

BACKGROUND Angiogenesis plays a crucial role in myocardial infarction (MI) treatment by ameliorating myocardial remodeling, thus improving cardiac function and preventing heart failure. Muscone has been reported to have beneficial effects on cardiac remodeling in MI mice. However, the effects of muscone on angiogenesis in MI mice and its underlying mechanisms remain unknown. MATERIAL AND METHODS Mice were randomly divided into sham, MI, and MI+muscone groups. The MI mouse model was established by ligating the left anterior descending coronary artery. Mice in the sham group received the same procedure except for ligation. Mice were administered muscone or an equivalent volume of saline for 4 consecutive weeks. Cardiac function was evaluated by echocardiograph after MI for 2 and 4 weeks. Four weeks later, all mice were sacrificed and Masson's trichrome staining was used to assess myocardial fibrosis. Isolectin B4 staining was applied to evaluate the angiogenesis in mouse hearts. Immunohistochemistry, Western blot analysis, and quantitative real-time polymerase chain reaction (qPCR) were performed to analyze expression levels of HIF-1a and its downstream genes. RESULTS Compared with the MI group, muscone treatment significantly improved cardiac function and reduced myocardial fibrosis. Moreover, muscone enhanced angiogenesis in the peri-infarct region and p-VEGFR2 expression in the vascular endothelial cells. Western blot analysis and qPCR showed that muscone upregulated expression levels of HIF-1a and VEGFA. CONCLUSIONS Muscone improved cardiac function in MI mice through augmented angiogenesis. The potential mechanism of muscone treatment in regulating angiogenesis of MI mice was upregulating expression levels of HIF-1α and VEGFA.

Mesenchymal stem cells attenuate doxorubicin‑induced cellular senescence through the VEGF/Notch/TGF‑β signaling pathway in H9c2 cardiomyocytes

The clinical use of doxorubicin (Dox) is limited by its cardiotoxicity. The fundamental changes it induces include interstitial myocardial fibrosis and the appearance of senescent cardiomyocytes. Mesenchymal stem cell (MSC)‑based therapies have also been reported to modulate cellular senescence, and have been used effectively to treat age‑related cardiovascular diseases. In the present study, the Transwell system was used to coculture H9c2 cells with MSCs, and their proliferation and viability were assessed. The expression of senescence‑related genes p53 and p16, and telomere length were measured using reverse transcription‑quantitative polymerase chain reaction analysis, and the Jagged‑1/Notch‑1 signaling pathway was detected using western blot analysis. The results revealed that Dox induced the senescence of H9c2 cells, characterized by a low proliferation rate, poor viability, reduced telomere length and impaired telomerase activity, and by marked increases in the expression of p53 and p16. By contrast, when cocultured with MSCs in the presence of Dox, H9c2 cell proliferation and viability increased, whereas the expression levels of p53 and p16 decreased, and telomere length and telomerase activity increased. The mechanism underlying the antisenescence function of MSCs was clarified, which involved the vascular endothelial growth factor (VEGF)/Jagged‑1/Notch‑1/transforming growth factor‑β1 (TGF‑β1) signaling pathway. It was confirmed that inhibiting VEGF, or silencing Jagged‑1 or Notch‑1 with small interfering RNA, or using recombinant TGF‑β1 eliminated the antisenescence effects of MSCs on the Dox‑treated H9c2 cells. The results revealed that MSCs rescued H9c2 cells from Dox‑induced senescence through the release of VEGF, which activated the Jagged‑1/Notch‑1 signaling pathway, leading to the inhibition of TGF‑β1 release. Therefore, treatment with MSCs may have important therapeutic implications on the attenuation of cardiotoxicity in patients with cancer treated with Dox.

Knockdown of long non-coding RNA MEG3 protects H9c2 cells from hypoxia-induced injury by targeting microRNA-183

Acute myocardial infarction (AMI) occurs when blood supply to the heart is diminished (ischemia) for long time, and ischemia is primarily caused due to hypoxia. This study evaluated the effects of long non-coding RNA maternally expressed gene 3 (MEG3) on hypoxic rat cardiomyocyte-drived H9c2 cells. Hypoxic injury was confirmed by alterations of cell viability, migration, invasion, apoptosis, and hypoxia-inducible factor 1α (HIF-1α) expression. MEG3 level in hypoxic cells and effects of its knockdown on hypoxic cells were assessed. The interactions between MEG3 and miR-183 as well as miR-183 and p27 were investigated. In addition, the effects of aberrantly expressed MEG3, miR-183, and p27 on hypoxic cells along with the activation of PI3K/AKT/FOXO3a signaling pathway were all assessed. Results showed that hypoxia induced decreases of cell viability, migration and invasion, and increases of apoptosis and expressions of HIF-1α and MEG3. Knockdown of MEG3 decreased hypoxia-induced injury in H9c2 cells. Knockdown of MEG3 also increased miR-183 expression, which was identified as a target of MEG3. The effects of MEG3 knockdown on the hypoxic cells were reversed by miR-183 silence. p27 was identified as a target gene of miR-183, and its expression negatively regulated by miR-183. The mechanistic studies revealed that knockdown of p27 decreased hypoxia-induced H9c2 cell injury by activating PI3K/AKT/FOXO3a signal pathways. These findings suggest that knockdown of MEG3 alleviates hypoxia-induced H9c2 cell injury by miR-183-mediated suppression of p27 through activation of PI3K/AKT/FOXO3a signaling pathway.

Signaling Pathways in Cardiac Myocyte Apoptosis

Cardiovascular diseases, the number 1 cause of death worldwide, are frequently associated with apoptotic death of cardiac myocytes. Since cardiomyocyte apoptosis is a highly regulated process, pharmacological intervention of apoptosis pathways may represent a promising therapeutic strategy for a number of cardiovascular diseases and disorders including myocardial infarction, ischemia/reperfusion injury, chemotherapy cardiotoxicity, and end-stage heart failure. Despite rapid growth of our knowledge in apoptosis signaling pathways, a clinically applicable treatment targeting this cellular process is currently unavailable. To help identify potential innovative directions for future research, it is necessary to have a full understanding of the apoptotic pathways currently known to be functional in cardiac myocytes. Here, we summarize recent progress in the regulation of cardiomyocyte apoptosis by multiple signaling molecules and pathways, with a focus on the involvement of these pathways in the pathogenesis of heart disease. In addition, we provide an update regarding bench to bedside translation of this knowledge and discuss unanswered questions that need further investigation.

Ad-HGF improves the cardiac remodeling of rat following myocardial infarction by upregulating autophagy and necroptosis and inhibiting apoptosis

Cell death in MI is the most critical determinant of subsequent left ventricular remodeling and heart failure. Besides apoptosis, autophagy and necroptosis have been recently found to be another two regulated cell death styles. HGF has been reported to have a protective role in MI, but its impact on the three death styles remains unclear. Thus, our study was performed to investigate the distribution of autophagy, apoptosis and necroptosis in cardiac tissues after MI and explore the role and mechanism of Ad-HGF on cardiac remodeling by regulating the three death styles. We firstly showed the distribution of autophagy, apoptosis and necroptosis differs in temporal and spatial context after MI using immunofluorescence. Notably, Ad-HGF treatment improves the cardiac remodeling of SD rats following MI by preserving the heart function, reducing the scar size and aggresomes. Further mechanism study reveals Ad-HGF promotes autophagy and necroptosis and inhibits apoptosis in vivo and in vitro. Co-immunoprecipitation assays showed Ad-HGF treatment significantly decreased the binding of Bcl-2 to Beclin1 but enhanced Bcl-2 binding to Bax in H9c2 cells under hypoxia. Moreover, HGF-induced sequestration of Bax by Bcl-2 allows Bax to become inactive, thereby inhibiting apoptosis. In addition, Ad-HGF markedly increased the formation of Beclin1-Vps34-Atg14L complex, which accounted for promoting autophagy. Both the western blot and activity assay showed Ad-HGF significantly decreased the caspase 8 protein and activity levels, which obligated the cell to undergo necroptosis under hypoxia and block apoptosis. Thus, our findings offer new evidence and strategies for the treatment of MI and post-MI cardiac remodeling.

Puerarin inhibits cardiac fibrosis via monocyte chemoattractant protein (MCP)-1 and the transforming growth factor-β1 (TGF-β1) pathway in myocardial infarction mice

Transforming growth factor-β1 (TGF-β1) and inflammation play important roles in the cardiac fibrosis development associated with myocardial infarction (MI). Puerarin is wildly used for treatment of diabetes, cardiovascular disease and cerebrovascular disease in China, and recently some studies have shown its anti-cardiac fibrotic effect on myocardial hypertrophy. The purpose of our study was to determine whether puerarin has an anti-cardiac fibrotic effect after MI and find the potential mechanism. A mouse model of MI was established by standard LAD coronary artery ligation, and cardiac fibrosis was confirmed by Masson's staining and the expression of collagen I, III and α-SMA. The expression level of F4/80 (macrophage/monocyte marker in mouse), monocyte chemoattractant protein (MCP)-1 and TGF-β1 in cardiac tissue treated with or without puerarin was evaluated by immunohistochemistry analysis, enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction (qPCR). The downstream protein phospho-Smad (small mother against decapentaplegic) 2/3 was evaluated by westernblot. The results displayed that puerarin could inhibit the recruitment and activation of monocytes/macrophages, decrease the expression of TGF-β1 in the cardiac tissues, and consequently significantly attenuated cardiac fibrosis after MI. Our results also displayed a strong positive correlation between MCP-1 and TGF-β1 expression in MI. Thus, this study revealed the mechanism by which prevented cardiac fibrosis after MI through a decrease in MCP-1 expression and an inhibition TGF-β1 pathway, and indicated puerarin could be a potential agent in attenuating MI-induced cardiac fibrosis.

Puerarin improves cardiac function through regulation of energy metabolism in Streptozotocin-Nicotinamide induced diabetic mice after myocardial infarction

It is well recognized that the incidence of heart failure and the risk of death is high in diabetic patients after myocardial infarction (MI). Accumulating evidence showed that puerarin (PUE) has protecting function on both cardiovascular disease and diabetes. The aim of this study is to explore whether puerarin could improve cardiac function in diabetic mice after MI and the underlying mechanism. The left anterior of Streptozotocin (STZ)-Nicotinamide (NA) induced diabetic mice were ligated permanently except for the Shame group. Then the operated mice were randomly treated with PUE or saline. Cardiac function was evaluated by echocardiograph before and at 1, 2, 4 weeks after MI. GLUT4/CD36/p-Akt/PPAR α of the heart was examined after treatment for 4 weeks. The results indicated that PUE significantly increased survival rate, improved cardiac function compared with MI group. Moreover, PUE increased expression and translocation of GLUT4 while attenuated expression and translocation of CD36. Western blot analysis showed that PUE enhanced phosphorylation of Akt and decreased PPAR α. This study demonstrated that PUE improved cardiac function after MI in diabetic mice through regulation of energy metabolism, the possible mechanism responsible for the effect of PUE was increasing the expression and translocation of GLUT4 while attenuating the expression and translocation of CD36.