Sirtuin 2 Exerts Regulatory Functions on Radiation-Induced Myocardial Fibrosis in Mice by Mediating H3K27 Acetylation of Galectin-3 Promoter.

Background: Sirtuin 2 (SIRT2) and galectin-3 have been shown to protect the heart against fibrosis. However, their impacts on radiation-induced myocardial fibrosis (RIMF) remain to be elucidated. To deepen this understanding, the current study sought to explore the effects of SIRT2 and galectin-3 on RIMF and the underlying mechanisms. Methods: Galectin-3 knockout mice were obtained, and a radiation-induced heart damage (RIHD) mouse model was induced by local radiation exposure to the heart. Lentivirus transfection was then performed, and heart function, fibrosis of heart tissues, and levels of SIRT2, galectin-3, and fibrosis-related markers collagen type-I/-III and matrix metalloproteinase (MMP)2/MMP9 were respectively assessed by echocardiography, hematoxylin-eosin and Masson staining, reverse transcription-quantitative polymerase chain reaction, Western blot, and immunofluorescence staining. Additionally, Western blot and chromatin immunoprecipitation were used to test H3K27 acetylation levels and the binding of H3K27ac to galectin-3, respectively. Results: After radiation exposure, heart tissues from the galectin-3 knockout mice had a smaller fibrotic area compared to normal mice, with reduced expression levels of collagen type-I/-III and MMP2/MMP9. SIRT2 was down-regulated and galectin-3 was up-regulated after RIHD treatment. The histone deacetylase inhibitor sirtinol promoted galectin-3 expression and H3K27 acetylation in a time-dependent manner, and increased H3K27ac enrichment in the galectin-3 promoter. Overexpression of SIRT2 down-regulated H3K27ac, collagen type-I/-III, and MMP2/MMP9 expression levels, and reduced the fibrotic area in mouse heart tissues. However, these effects were reversed by the additional overexpression of galectin-3. Conclusions: SIRT2 facilitates deacetylation of H3K27 to inhibit galectin-3 transcription, thus ameliorating RIMF in mice.

Analysis of risk factors for postoperative acute cerebral infarction in patients with type B aortic dissection.

OBJECTIVE: To study risk factors of postoperative acute cerebral infarction (PACI) in patients with type B aortic dissection (TB-AD). METHODS: The data of 36 patients with TB-AD and PACI undergoing endovascular aortic repair (EVAR) from Mar 2018 and Mar 2021 were collected as the PACI group retrospectively. The data of 114 TB-AD patients without PACI were collected as the control group retrospectively. The medical history, surgery-related indicators, general data, imaging data and laboratory test results (D-dimer (D-D), preoperative serum creatinine and preoperative white blood cell count) were compared. Then, logistic regression was applied to analyze risk factors for PACI in TB-AD patients. RESULTS: The surgery time, blood loss and hospital stay of patients in the PACI group were determined to be obviously higher/longer when comparing to those in the control group. Aortic arch radius of curvature and length of proximal anchoring zone showed no significant difference between the two groups. Pearson correlation analysis indicated that D-D level after surgery was positively related to white blood cell count and serum creatinine level in TB-AD patients. Binary logistic regression analysis showed that operation time, emergency surgery, preoperative D-D and preoperative serum creatinine level were independent risk factors for PACI after EVAR in the patients with TB-AD (P < 0.05). CONCLUSION: There are many independent risk factors for PACI after EVAR in patients with TB-AD, and preoperative D-D level and serum creatinine level should be given attention.

MiR-30a-5p Promotes Vein Graft Restenosis by Inhibiting Cell Autophagy through Targeting ATG5.

OBJECTIVE: The aim of the study was to investigate the role of miR-30a-5p in restenosis of rats following vein grafting and the underlying mechanism. METHODS: Vein graft rat models were established and perfused with miR-30a-5p antagomir and si-ATG5 to probe the regulation of miR-30a-5p/ATG5 on intimal hyperplasia. Human saphenous vein smooth muscle cells (HSVSMCs) were obtained from the great saphenous veins of patients undergoing coronary artery bypass grafting and subjected to assays for autophagy, proliferation, and migration after gain and loss of function of miR-30a-5p and/or ATG5. The binding of miR-30a-5p and ATG5 was confirmed by RIP and dual-luciferase reporter assays. RESULTS: MiR-30a-5p expression gradually increased, ATG5 expression gradually decreased, and the intima was increasingly thickened during restenosis of grafted veins. Knockdown of miR-30a-5p in rats repressed the restenosis of vein grafts, while a deficiency of ATG5 reversed the effect of miR-30a-5p inhibition. Upregulation of miR-30a-5p enhanced the proliferation and migration of HSVSMCs and inhibited the autophagy, while downregulation of miR-30a-5p or overexpression of ATG5 showed opposite effects. ATG5 is a target gene of miR-30a-5p. CONCLUSION: MiR-30a-5p exacerbates vein graft restenosis by repressing ATG5 expression and inhibiting autophagy.

The potential function of SP1 and CPPED1 in restenosis after percutaneous coronary intervention.

OBJECTIVES: Impacts of molecular pathways have been discussed recently on restenosis after percutaneous coronary intervention (PCI). Hence, this study aimed to explore the impact of calcineurin-like phosphoesterase domain containing 1 (CPPED1) and specificity protein 1 (SP1) on restenosis after PCI. METHODS: A carotid balloon injury rat model was established, followed by western blot analysis of SP1 and CPPED1 expression in carotid artery (CA) tissues. After SP1 and CPPED1 were overexpressed, the neointimal hyperplasia and luminal stenosis were assessed. In addition, EPC underwent hypoxia/reoxygenation (H/R) treatment to construct an endothelial injury cell model. Then, cell proliferation, apoptosis, intracellular reactive oxygen species (ROS), and Ca2+ concentration were detected with cell counting kit-8 (CCK-8), flow cytometry, Chloromethyl-2'7'-dichlorofluorescein diacetate (CM-H2DCFDA) penetrant, and Fluo-4 AM staining, respectively. The binding relationship between SP1 and CPPED1 was verified by dual-luciferase reporter and chromatin immunoprecipitation (ChIP) assays. RESULTS: SP1 and CPPED1 were lowly expressed in the model rats with carotid balloon injury. Mechanistically, SP1 bound to the promoter region of CPPED1 to activate CPPED1 expression. Overexpressing SP1 or CPPED1 lowered neointimal formation and restenosis rate, thus promoting the recovery of carotid balloon injury in rats. Meanwhile, SP1 and CPPED1 upregulation reduced ROS levels, Ca2+ concentration, and apoptosis of EPCs, accompanied by accelerated EPC viability. CONCLUSIONS: SP1 or CPPED1 overexpression reduced neointimal formation and restenosis rate in carotid balloon injury.

Salmonella pathogenicity island 1 knockdown confers protection against myocardial fibrosis and inflammation in uremic cardiomyopathy via down-regulation of S100 Calcium Binding Protein A8/A9 transcription.

BACKGROUND/AIM: Uremic cardiomyopathy (UCM) is a characteristic cardiac pathology that is commonly found in patients with chronic kidney disease. This study dissected the mechanism of SPI1 in myocardial fibrosis and inflammation induced by UCM through S100A8/A9. METHODS: An UCM rat model was established, followed by qRT-PCR and western blot analyses of SPI1 and S100A8/A9 expression in myocardial tissues. After alterations of SPI1 and S100A8/A9 expression in UCM rats, the blood specimens were harvested from the cardiac apex of rats. The levels of creatine phosphokinase-MB (CK-MB), blood creatinine, blood urea nitrogen (BUN), and inflammatory cytokines (interleukin [IL]-6, IL-1ß, and tumor necrosis factor-α [TNF-α]) were examined in the collected blood. Collagen fibrosis was assessed by Masson staining. The expression of fibrosis markers [transforming growth factor (TGF)-ß1, α-smooth muscle actin (SMA), Collagen 4a1, and Fibronectin], IL-6, IL-1ß, and TNF-α was measured in myocardial tissues. Chromatin immunoprecipitation and dual-luciferase reporter gene assays were conducted to test the binding relationship between SPI1 and S100A8/A9. RESULTS: S100A8/A9 and SPI1 were highly expressed in the myocardial tissues of UCM rats. Mechanistically, SPI1 bound to the promoter of S100A8/A9 to facilitate S100A8/A9 transcription. S100A8/A9 or SPI1 knockdown reduced myocardial fibrosis and inflammation and the levels of CK-MB, blood creatinine, and BUN, as well as the expression of TGF-ß1, α-SMA, Collagen 4a1, Fibronectin, IL-6, TNF-α, and IL-1ß in UCM rats. CONCLUSION: SPI1 knockdown diminished S100A8/A9 transcription, thus suppressing myocardial fibrosis and inflammation caused by UCM.

Vinpocetine and coenzyme Q10 combination alleviates cognitive impairment caused by ionizing radiation by improving mitophagy.

OBJECTIVE: This research was designed to ascertain the effect and mechanism of vinpocetine (VIN) and coenzyme Q10 (CoQ10) combination on cognitive impairment induced by ionizing radiation (IR). METHODS: Cognitive impairment in mice was induced by 9-Gy IR, and they were intraperitoneally injected with VIN, CoQ10, or VIN + CoQ10. Then novel object recognition and Morris water maze tests were used to detect cognitive function. The number of hippocampal neurons and BrdU+Dcx+ cells was observed by Nissl and immunofluorescence staining. Mitochondrial respiratory complex I, adenosine triphosphate (ATP), and mitochondrial membrane potential (MMP) were evaluated, as well as oxidative stress injury. Mitophagy in hippocampal neurons was evaluated by observing the ultrastructure of hippocampal neurons and assessing the expression of mitophagy-related proteins. RESULTS: IR reduced novel object discrimination index, the time for platform crossing, and the time spent in platform quadrant, in addition to neuron loss, downregulated levels of mitochondrial respiratory complex I, ATP, and MMP, aggravated oxidative stress injury, increased expression of LC3 II/I, Beclin1, PINK1, and parkin, and decreased P62 expression. VIN or CoQ10 treatment mitigated cognitive dysfunction, neurons loss, mitochondrial damage, and oxidative stress injury, and enhanced mitophagy in hippocampal neurons. VIN and CoQ10 combination further protected against IR-induced cognitive dysfunction than VIN or CoQ10 alone. CONCLUSION: VIN combined with CoQ10 improved neuron damage, promoted mitophagy, and ameliorated cognitive impairment in IR mice.

Circ-SKA3 Enhances Doxorubicin Toxicity in AC16 Cells Through miR-1303/TLR4 Axis.

Doxorubicin (DOX) is a widely used anticancer drug, but its cardiotoxicity largely limits its clinical utilization. Circular RNA spindle and kinetochore-associated protein 3 (circ-SKA3) were found to be differentially expressed in heart failure patients. In this study, we investigated the role and mechanism of circ-SKA3 in DOX-induced cardiotoxicity.The quantitative real-time polymerase chain reaction and western blot assays were applied to measure the expression of circ-SKA3, microRNA (miR) -1303, and toll-like receptor 4 (TLR4). The viability and apoptosis of AC16 cells were analyzed using cell counting kit-8, flow cytometry, and western blot assays. The interaction between miR-1303 and circ-SKA3 or TLR4 was verified using dual-luciferase reporter and RNA immunoprecipitation assays. Exosomes were collected from culture media by the use of commercial kits and then qualified by transmission electron microscopy.The expression of circ-SKA3 and TLR4 was increased, whereas miR-1303 expression was decreased in DOX-treated AC16 cells. DOX treatment promoted cell apoptosis and inhibited cell viability in AC16 cells in vitro, which was partially reversed by circ-SKA3 knockdown, TLR4 silencing, or miR-1303 overexpression. Mechanistically, circ-SKA3 served as a sponge for miR-1303 to upregulate TLR4, which was confirmed to be a target of miR-1303. Additionally, circ-SKA3 contributed to DOX-induced cardiotoxicity through the miR-1303/TLR4 axis. Further studies suggested that circ-SKA3 was overexpressed in exosomes extracted from DOX-mediated AC16 cells, which could be internalized by surrounding untreated AC16 cells.Circ-SKA3 enhanced DOX-induced toxicity in AC16 cells through the miR-1303/TLR4 axis. Extracellular circ-SKA3 was packaged into exosomes, and exosomal circ-SKA3 could function as a mediator in intercellular communication between AC16 cells.

CircJARID2 Regulates Hypoxia-Induced Injury in H9c2 Cells by Affecting miR-9-5p-Mediated BNIP3.

ABSTRACT: Myocardial infarction (MI) is a common cardiovascular disease, and many circular RNAs (circRNAs) have been found to participate in the pathological process. This study was to research circRNA jumonji and AT-rich interaction domain containing 2 (circJARID2) in MI. MI cell model was established by hypoxia treatment in H9c2 cells. CircJARID2 and microRNA-9-5p (miR-9-5p) levels were examined using real-time polymerase chain reaction. Cell viability detection was performed by Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (Edu) assays. Cell apoptosis was evaluated by flow cytometry and caspase-3 activity assay. Apoptotic markers and B-cell lymphoma-2 (Bcl-2) interacting protein 3 (BNIP3) were quantified by western blot. Inflammatory cytokines were determined via enzyme-linked immunosorbent assay. The genic interaction was analyzed through dual-luciferase reporter and RNA immunoprecipitation assays. Hypoxia induced the upregulation of circJARID2 expression in H9c2 cells. The hypoxia-induced cell viability inhibition, apoptosis promotion, and inflammatory response were all counterbalanced by knockdown of circJARID2. CircJARID2 interacted with miR-9-5p, and its function in regulating the hypoxia-induced cell injury was also dependent on targeting miR-9-5p. BNIP3 acted as a target gene of miR-9-5p, and circJARID2 had positive effect on BNIP3 expression by binding to miR-9-5p. MiR-9-5p played a protective role for H9c2 cells against the hypoxia-induced injury via targeting BNIP3. CircJARID2 overexpression contributed to the hypoxia-induced H9c2 cell injury by sponging miR-9-5p to upregulate BNIP3 expression, showing a novel molecular network of MI pathomechanism.

Inhibition of miR-322-5p Protects Cardiac Myoblast Cells Against Hypoxia-Induced Apoptosis and Injury Through Regulating CIAPIN1.

ABSTRACT: Hypoxia leads to insufficient supply of blood and nutrients, which is major incentive for cardiomyocyte injury and apoptosis. Previous studies reported the regulation effects of microRNAs (miRNAs) in myocardial infarction, whereas function and molecular mechanisms of miR-322-5p were still unclear. Therefore, our study focused on the biological role of miR-322-5p in hypoxia-induced cardiac myoblast cells apoptosis and injury. The expression levels of miR-322-5p and cytokine-induced apoptosis inhibitor 1 (CIAPIN1) were measured by real-time quantitative polymerase chain reaction in cardiac myoblast cells. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazol-3-ium bromide (MTT), lactic dehydrogenase, and flow cytometry assays were performed to examine proliferation, injury, and apoptosis of cardiac myoblast cells, respectively. The protein expression levels were evaluated with western blot assay. The relationship between miR-322-5p and CIAPIN1 was confirmed by dual-luciferase reporter analysis. We found that miR-322-5p level was increased in cardiac myoblast cells exposed to hypoxia. In addition, miR-322-5p silencing could weaken injury and apoptosis in cardiac myoblast cells induced by hypoxia; meanwhile, inhibition of miR-322-5p activation of phosphatidylinositol-3 kinases (PI3K)/protein kinase B (AKT) signal pathway. Besides, CIAPIN1 was a target mRNA of miR-322-5p based on bioinformatics prediction. CIAPIN1 knockdown reversed the effects of miR-322-5p silencing on hypoxic cardiac myoblast cells. Suppression of miR-322-5p protected cardiac myoblast cells against hypoxia-induced injury and apoptosis through regulation of CIAPIN1 expression and PI3K/AKT signal pathway.

Targeting NOX 4 by petunidin improves anoxia/reoxygenation-induced myocardium injury.

Oxidative stress is the key factor of myocardial ischemia-reperfusion injury (MIRI). Anthocyanins are considered to be effective anti-oxidants. In this study, we observed the anti-MIRI effect of petunidin, one member of anthocyanins, and further explored its mechanism. In present study, anoxia/reoxygenation (A/R) models were replicated on Langendorff-perfused heart and neonatal rat primary cardiomyocytes by A/R treatment. The hemodynamic parameters of isolated hearts were monitored. The levels of oxidative stress and apoptosis in isolated heart and neonatal rat primary cardiomyocytes were evaluated. The expression levels of NADPH oxidase 2 (NOX 2), NOX 4, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax) and cytochrome c were detected by Western Blot. The results showed that petunidin could significantly improve isolated heart function, reduce oxidative stress, inhibit cardiomyocyte apoptosis, up-regulate Bcl-2 protein expression, down-regulate NOX4 and Bax expression, and reduce the level of cytoplasmic cytochrome c after A/R. However, it has no significant effect on NOX 2 protein expression, suggesting that NOX 4 may be the molecular target of petunidin. In vitro, petunidin had shown a consistent effect with that in isolated hearts. It also showed a significant inhibitory effect on reactive oxygen species (ROS) generation. However, the protective effects of petunidin on A/R injury were attenuated by over-expression of NOX 4 in neonatal rat primary cardiomyocytes. These data suggested that the protective effects of petunidin on MIRI may be achieved through targeting NOX 4, thus inhibiting the production of ROS, reducing oxidative stress, and regulating the Bcl-2 pathway to prevent cardiomyocytes apoptosis.

LINC-PINT alleviates lung cancer progression via sponging miR-543 and inducing PTEN.

Long intergenic nonprotein coding RNA p53-induced transcript (LINC-PINT) has been reported to participate in various cancers. Here, we investigated the effects of LINC-PINT on lung cancer progression. Firstly, in our study, we implied that LINC-PINT was obviously decreased in NSCLC. Thereafter, in A549 and H1299 cells, LINC-PINT was upregulated via transfecting LV-LINC-PINT. As exhibited, LINC-PINT repressed cell proliferation and cell colony formation of A549 and H1299 cells. Subsequently, flow cytometry evidenced that A549 and H1299 cell apoptosis was obviously triggered and the cell cycle was arrested in G1 phase. Then, migration and transwell invasion experiments were carried out to detect the cell migration and invasion capacity. We found A549 and H1299 cell migration and invasion capacity were restrained by the upregulation of LINC-PINT. Meanwhile, we predicted that miR-543 could function as the target of LINC-PINT and the association was verified. Moreover, we exhibited that miR-543 was remarkably increased in lung cancer, which could be regulated by LINC-PINT negatively. Furthermore, PTEN could act as the downstream target of miR-543 and upregulation of miR-543 repressed PTEN, which was reversed by LV-PINT in A549 and H1299 cells. Finally, xenografts were utilized to confirm the function of LINC-PINT on lung cancer. All these findings concluded that LINC-PINT exerted crucial biological roles in NSCLC through sponging miR-543 and inducing PTEN.

PTPN2 negatively regulates macrophage inflammation in atherosclerosis.

Atherosclerosis is the main cause of cardiovascular disease. Systemic inflammation is one important characteristic in atherosclerosis. Pro-inflammatory macrophages can secrete inflammatory factors and promote the inflammation of atherosclerosis. It has a great value for the treatment of atherosclerosis by inhibiting the release of inflammatory factors in macrophages. However, the detailed mechanism of this process is still unclear. In this study, we constructed an APOE-/- mice model of atherosclerosis to research the molecular mechanism of atherosclerosis. Protein tyrosine phosphatase non-receptor type 2 (PTPN2), an anti-inflammatory gene, was dramatically decreased in inflammatory mice. Deletion of PTPN2 could significantly induce monocytes toward M1 phenotype of macrophages, enhance the secretion of IL-12 and IL-1, and promote cell proliferation, invasion and metastasis. Mechanism research showed that PTPN2-mediated p65/p38/STAT3 de-phosphorylation could block the process of macrophage inflammation. In vivo experiments showed that PTPN2 may effectively inhibit the inflammatory response during atherosclerosis. In conclusion, we uncovered the negative role of PTPN2 in the occurrence of atherosclerosis, and this study provides a new potential target for atherosclerosis treatment.

The true colors of autophagy in doxorubicin-induced cardiotoxicity.

Patients with cancer receiving doxorubicin-based chemotherapy often have to stop taking the drug due to its cardiotoxicity and therefore lose out on the beneficial effects of its potent antitumor activity. Doxorubicin has been demonstrated to damage cardiomyocytes via various mechanisms, including accumulation of reactive oxygen species (ROS), DNA damage and autophagy dysfunction. The present review focuses on autophagy, describing the general process of autophagy and the controversy surrounding its role in doxorubicin-induced cardiotoxicity. In addition, the associations between autophagy and apoptosis, ROS, DNA damage and inflammatory processes are discussed. In the future, it will be useful to further elucidate the process of autophagy and reveal its association with various pathological processes to develop effective strategies of preventing doxorubicin-induced cardiotoxicity.

Iron-load exacerbates the severity of atherosclerosis via inducing inflammation and enhancing the glycolysis in macrophages.

Atherosclerosis is still the major cause of morbidity and mortality all over the world. Recently, it has been reported increased levels of tissue iron increase the risk of atherosclerosis. However, the detailed mechanism of iron-induced atherosclerosis progression is barely known. Here, we used apoE-deficient mice models to investigate the effects of low iron diet (<0 mg iron carbonyl/kg), high iron diet (25,000 mg iron carbonyl/kg) on atherosclerosis in vivo. As exhibited, we observed that CD68 was significant enriched by high iron diet in apoE-deficient mice. In addition, transforming growth factor ß, tumor necrosis factor α, interleukin 6 (IL-6), IL-23, IL-10, and IL-1ß levels were also greatly induced by high iron diet. Then, we found that the iron load promoted the inflammation response in macrophages. Moreover, macrophage polarization is a process by which macrophage can express various functional programs in activating macrophages. Here, we observed that iron-load macrophages were polarized toward a proinflammatory macrophage phenotype. The polarization of M1 macrophage was promoted by ferric ammonium citrate (FAC) in bone marrow derived macrophages (BMDMs). Furthermore, ECAR and cellular OCR in BMDM with or without FAC was examined. As shown, BMDM indicated with 50 µM FAC showed a significant increase in basic state and maximal ECAR in contrast to the control group. However, there was no significant difference in OCR. This indicated that the glycolysis was involved in the polarization of M1 macrophage triggered by iron-load. In conclusion, we indicated that the iron load exacerbates the progression of atherosclerosis via inducing inflammation and enhancing glycolysis in macrophages.

Novel triadius-like N4 specie of iron nitride compounds under high pressure.

Various nitrogen species in nitrides are fascinating since they often appear with these nitride as superconductors, hard materials, and high-energy density. As a typical complex, though iron nitride has been intensively studied, nitrogen species in the iron-nitrogen (Fe-N) compounds only have been confined to single atom (N) or molecule nitrogen (N2). Using a structure search method based on the CALYPSO methodology, unexpectedly, we here revealed two new stable high pressure (HP) states at 1:2 and 1:4 compositions with striking nitrogen species. The results show that the proposed FeN2 stabilizes by a break up of molecule N2 into a novel planar N4 unit (P63/mcm, >228 GPa) while FeN4 stabilizes by a infinite 1D linear nitrogen chains N∞ (P-1, >50 GPa; Cmmm, >250 GPa). In the intriguing N4 specie of P63/mcm-FeN2, we find that it possesses three equal N = N covalent bonds and forms a perfect triadius-like configuration being never reported before. This uniqueness gives rise to a set of remarkable properties for the crystal phase: it is identified to have a good mechanical property and a potential for phonon-mediated superconductivity with a Tc of 4-8 K. This discovery puts the Fe-N system into a new class of desirable materials combining advanced mechanical properties and superconductivity.