Targeting Glycogen Synthase Kinase 3 Beta Regulates CD47 Expression After Myocardial Infarction in Rats via the NF-κB Signaling Pathway.
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ABSTRACT:
SUBMITTER: Xu LN
PROVIDER: S-EPMC8327268 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The molecular pathways that regulate the extent of ischemic injury and post-myocardial infarction (MI) remodeling are not well understood. We recently demonstrated that glycogen synthase kinase-3? (GSK-3?) is critical to the heart's response to pressure overload. However, the role, if any, of GSK-3? in regulating ischemic injury and its consequences is not known.MI was induced in wild-type (WT) versus GSK-3?((-/-)) (KO) littermates by left anterior descending coronary artery ligation. Pre-MI, WT, and KO hearts had comparable chamber dimensions and ventricular function, but as early as 1 week post-MI, KO mice had significantly more left ventricular dilatation and dysfunction than WT mice. KO mice also had increased mortality during the first 10 days post-MI (43% versus 22%; P=0.04), and postmortem examination confirmed cardiac rupture as the cause of most of the deaths. In the mice that survived the first 10 days, left ventricular dilatation and dysfunction remained worse in the KO mice throughout the study (8 weeks). Hypertrophy, fibrosis, and heart failure were all increased in the KO mice. Given the early deaths due to rupture and the significant reduction in left ventricular function evident as early as 1 week post-MI, we examined infarct size following a 48-hour coronary artery ligation and found it to be increased in the KO mice. This was accompanied by increased apoptosis in the border zone of the MI. This increased susceptibility to ischemic injury-induced apoptosis was also seen in cardiomyocytes isolated from the KO mice that were exposed to hypoxia. Finally, Bax translocation to the mitochondria and cytochrome C release into the cytosol were increased in the KO mice.GSK-3? confers resistance to ischemic injury, at least in part, via limiting apoptosis. Loss of GSK-3? promotes ischemic injury, increases risk of cardiac rupture, accentuates post-MI remodeling and left ventricular dysfunction, and increases the progression to heart failure. These findings are in striking contrast to multiple previous reports in which deletion or inhibition of GSK-3? is protective.
| S-EPMC4365497 | biostudies-literature
Project description:Previous studies have provided evidence for the regulatory effect of P2X7 receptor (P2X7R) on cardiovascular activities. Our study focused on exploring the function and fundamental mechanism of microglial P2X7R in controlling sympathoexcitatory response using rats with acute myocardial infarction (AMI). Coronary artery ligation was used in rats to cause AMI. And before that, rats were administrated with P2X7R siRNA that targeted P2X7R mRNA into paraventricular nucleus (PVN) or BBG (Brilliant Blue G, a P2X7 receptor antagonist). Increased expression levels of P2X7R and adenosine triphosphate (ATP) were observed in the hypothalamic PVN of AMI rats. Moreover, the knockdown of P2X7R expression by P2X7-siRNA or suppression of P2X7 receptor by BBG attenuated the elevation of both vasopressin and oxytocin levels in the PVNs of AMI rats. There was also a decrease in renal sympathetic nerve activity (RSNA) by P2X7-siRNA and BBG. Besides, inflammation was alleviated by P2X7-siRNA and BBG through suppressing pro-inflammatory cytokines IL-1β and IL-6 in PVN of AMI rats. Furthermore, blockade of P2X7R moderated the process of cardiac remodeling. This was achieved due to the regulatory effect of P2X7R on sympathoexcitatory response by influencing NF-κB and mitogen-activated protein kinase (MAPK) signaling. These findings suggest that P2X7R can act as a new regulator of sympathoexcitatory response via NF-κB and MAPK signaling pathways in AMI rats.
| S-EPMC5714779 | biostudies-literature
Project description:Numerous studies have proposed that glycogen synthase kinase (GSK)-3beta is a central regulator of the hypertrophic response of cardiomyocytes. However, all of this work has relied on overexpression of GSK-3beta, expression of constitutively active mutants, or small molecule inhibitors with documented off-target effects. Genetic loss of function approaches have not been used in the adult mouse because germ-line deletion of GSK-3beta is embryonic-lethal.This study was designed to define the role played by GSK-3beta in pressure overload (PO)-induced hypertrophy and remodeling following myocardial infarction (MI).We used a mouse model that allows inducible, cardiomyocyte-specific deletion of GSK-3beta in the adult knockout. Surprisingly, we find that knockout mice exposed to PO induced by thoracic aortic constriction exhibit a normal hypertrophic response. Thus, in contrast to virtually all prior published studies, GSK-3beta appears to play at most a minor role in the hypertrophic response to PO stress. However, GSK-3beta does regulate post-MI remodeling because the GSK-3beta knockouts had less left ventricular dilatation and better-preserved left ventricular function at up to 8 weeks post-MI despite demonstrating significantly more hypertrophy in the remote myocardium. Deletion of GSK-3beta also led to increased cardiomyocyte proliferation following PO and MI.Deletion of GSK-3beta protects against post-MI remodeling and promotes stress-induced cardiomyocyte proliferation in the adult heart. These studies suggest that inhibition of GSK-3beta could be a strategy to both prevent remodeling and to promote cardiac regeneration in pathological states.
| S-EPMC2895414 | biostudies-literature
Project description:A key feature of acute myocardial infarction (AMI) is an alteration in cardiac architecture. Signaling events that result in the inhibition of glycogen synthase kinase-3 (GSK-3)? represent an adaptive response that might limit the extent of adverse remodeling in the aftermath of AMI. Here, we report that an allosteric inhibitor of GSK-3?, 4-benzyl-2-(naphthalene-1-yl)-1,2,4-thiadiazolidine-3,5-dione (NP12), lessens the magnitude of adverse myocardial remodeling and promotes angiogenesis. Male and female mice 8-10 weeks old were grouped (six animals in each group) into sham surgery (sham group), left anterior descending (LAD) ligation of the coronary artery followed by intramyocardial PBS injections (control group), and LAD ligation followed by NP12 administration (NP12 group). After 7 and 14 days, the extents of fibrosis and integrity of blood vessels were determined. Intramyocardial administration of NP12 increased phosphorylation of GSK-3?, reduced fibrosis, and restored diastolic function in the mice that had experienced an AMI. Morphometric analyses revealed increased CD31+ and Ki67+ vascular structures and decreased apoptosis in these mice. NP12 administration mediated proliferation of reparative cells in the AMI hearts. In a time-course analysis, Wnt3a and NP12 stabilized ?-catenin and increased expression of both Nanog and VEGFR2. Moreover, NP12 increased the expression of ?-catenin and Nanog in myocardium from AMI mice. Finally, loss- and gain-of-function experiments indicated that the NP12-mediated benefit is, in part, Nanog-specific. These findings indicate that NP12 reduces fibrosis, reestablishes coronary blood flow, and improves ventricular function following an AMI. We conclude that NP12 might be useful for limiting ventricular remodeling after an AMI.
| S-EPMC5733612 | biostudies-literature
Project description:In this study, we aim to investigate the role of tanshinone IIA in myocardial infarction (MI), especially in left ventricular remodelling (VR) and the underlying mechanism involving the TLR4/MyD88/NF-κB signalling pathway. Sprague-Dawley (SD) rats (n = 96) were selected, and 12 of them underwent sham surgery. The remaining 84 rats were subjected to MI modelling. HE and MT staining were carried out to estimate infract size, histopathological changes and fibrosis degree. Macrophage infiltration and cardiomyocyte apoptosis were evaluated by immunohistochemistry and TUNEL staining. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting were used to determine the expression levels of TLR4, MyD88 and NF-κB. Serum levels of IL-2, IL-6, IL-8, TNF-a, procollagen I Cpropeptide (PICP), and procollagen III N-propeptide (PIIINP) were measured using enzyme-linked immunosorbent assay (ELISA). The heart weight/body weight, mean arterial pressure (MAP), left ventricular end-systolic pressure (LVESP), +dP/dt and -dP/dt increased while the ventricular function and the left ventricular end-diastole pressure (LVEDP) decreased in MI rats. Compared with the rats undergoing sham surgery, MI rats showed larger infarct size, severer fibrosis, higher expression levels of TLR4, NF-κB-P65, MyD88, IL-2, IL-6, IL-8, TNF-a, PICP and PIIINP as well as enhanced macrophage infiltration, cardiomyocyte apoptosis. After treatment with tanshinone IIA combined with LPS for 4 weeks, the rats showed better condition than those treated with only LPS. These results indicate that tanshinone IIA attenuates MI and prevents left VR. Importantly, inhibition of TLR4/MyD88/NF-κB signalling pathway is a key step in this process.
| S-EPMC5980158 | biostudies-literature
Project description:Background The neonatal heart maintains its entire regeneration capacity within days after birth. Using quantitative phosphoproteomics technology, we identified that SGK3 (serine/threonine-protein kinase 3) in the neonatal heart is highly expressed and activated after myocardial infarction. This study aimed to uncover the function and related mechanisms of SGK3 on cardiomyocyte proliferation and cardiac repair after apical resection or ischemia/reperfusion injury. Methods and Results The effect of SGK3 on proliferation and oxygen glucose deprivation/reoxygenation- induced apoptosis in isolated cardiomyocytes was evaluated using cardiomyocyte-specific SGK3 overexpression or knockdown adenovirus5 vector. In vivo, gain- and loss-of-function experiments using cardiomyocyte-specific adeno-associated virus 9 were performed to determine the effect of SGK3 in cardiomyocyte proliferation and cardiac repair after apical resection or ischemia/reperfusion injury. In vitro, overexpression of SGK3 enhanced, whereas knockdown of SGK3 decreased, the cardiomyocyte proliferation ratio. In vivo, inhibiting the expression of SGK3 shortened the time window of cardiac regeneration after apical resection in neonatal mice, and overexpression of SGK3 significantly promoted myocardial repair and cardiac function recovery after ischemia/reperfusion injury in adult mice. Mechanistically, SGK3 promoted cardiomyocyte regeneration and myocardial repair after cardiac injury by inhibiting GSK-3β (glycogen synthase kinase-3β) activity and upregulating β-catenin expression. SGK3 also upregulated the expression of cell cycle promoting genes G1/S-specific cyclin-D1, c-myc (cellular-myelocytomatosis viral oncogene), and cdc20 (cell division cycle 20), but downregulated the expression of cell cycle negative regulators cyclin kinase inhibitor P 21 and cyclin kinase inhibitor P 27. Conclusions Our study reveals a key role of SGK3 on cardiac repair after apical resection or ischemia/reperfusion injury, which may reopen a novel therapeutic option for myocardial infarction.
| S-EPMC8751936 | biostudies-literature
Project description:Glycogen synthase kinase-3? (GSK-3?), a serine/threonine protein kinase, may function as a tumor suppressor or an oncogene, depending on the tumor type. We sought to determine the biological function of GSK-3? in osteosarcoma, a rare pediatric cancer for which the identification of new therapeutic targets is urgent.We used cell viability assays, colony formation assays, and apoptosis assays to analyze the effects of altered GSK-3? expression in U2OS, MG63, SAOS2, U2OS/MTX300, and ZOS osteosarcoma cell lines. Nude mice (n = 5-8 mice per group) were injected with U2OS/MTX300, and ZOS cells to assess the role of GSK-3? in osteosarcoma growth in vivo and to evaluate the effects of inhibitors and/or anticancer drugs on tumor growth. We used an antibody array, polymerase chain reaction, western blotting, and a luciferase reporter assay to establish the effect of GSK-3? inhibition on the nuclear factor-?B (NF-?B) pathway. Immunochemistry was performed on primary tumor specimens from osteosarcoma patients (n = 74) to determine the relationship of GSK-3? activity with overall survival.Osteosarcoma cells with low levels of inactive p-Ser9-GSK-3? formed colonies in vitro and tumors in vivo more readily than cells with higher levels and cells in which GSK-3? had been silenced formed fewer colonies and smaller tumors than parental cells. Silencing or pharmacological inhibition of GSK-3? resulted in apoptosis of osteosarcoma cells. Inhibition of GSK-3? resulted in inhibition of the NF-?B pathway and reduction of NF-?B-mediated transcription. Combination treatments with GSK-3? inhibitors, NF-?B inhibitors, and chemotherapy drugs increased the effectiveness of chemotherapy drugs in vitro and in vivo. Patients whose osteosarcoma specimens had hyperactive GSK-3?, and nuclear NF-?B had a shorter median overall survival time (49.2 months) compared with patients whose tumors had inactive GSK-3? and NF-?B (109.2 months).GSK-3? activity may promote osteosarcoma tumor growth, and therapeutic targeting of the GSK-3? and/or NF-?B pathways may be an effective way to enhance the therapeutic activity of anticancer drugs against osteosarcoma.
| S-EPMC3352834 | biostudies-literature
Project description:Glucocorticoids (GCs) bind to the glucocorticoid receptor (GR) to regulate diverse biological functions from cell growth to apoptosis. Drugs that mimic their action are the most commonly prescribed therapeutic agents in the world and are currently used for the treatment of many diseases including asthma, autoimmune disorders, and some cancers. However, the mechanisms by which one hormone, via one receptor, modulates such diverse biological functions remain unclear. We hypothesized that epigenetic alteration to the GR may contribute to its signaling diversity, and here we demonstrate that Glycogen Synthase Kinase-3-beta phosphorylates GR on Serine 404 in a glucocorticoid-dependent manner. U-2 OS cells expressing a mutant GR that is incapable of Ser404 phosphorylation have enhanced global transcriptional responses, stronger NF-kappaB transrepression, and enhanced cell death in response to dexamethasone. Conversely, presence of Ser404 phosphorylation on the GR inhibits glucocorticoid-dependent NF-kappaB transrepression and cell death of these osteoblasts. Collectively, our results describe a novel convergence point of the GSK-3-beta pathway with the GR resulting in altered glucocorticoid regulated signaling. Our results also provide a mechanism by which the phosphorylation status of Ser404 in GR can dictate how cells will ultimately respond to GCs. Keywords: Glucocorticoid Receptor; GSK-3-beta; NF-kappaB Transrepression; Phosphorylation
2008-11-24 | GSE11205 | GEO
Project description:AimsTo resolve the controversy as to whether periostin plays a role in myocardial regeneration after myocardial infarction (MI), we created a neonatal mouse model of MI to investigate the influence of periostin ablation on myocardial regeneration and clarify the underlying mechanisms.Methods and resultsNeonatal periostin-knockout mice and their wildtype littermates were subjected to MI or sham surgery. In the wildtype mice after MI, fibrosis was detectable at 3 days and fibrotic tissue was completely replaced by regenerated myocardium at 21 days. In contrast, in the knockout mice, significant fibrosis in the infarcted area was present at even 3 weeks after MI. Levels of phosphorylated-histone 3 and aurora B in the myocardium, detected by immunofluorescence and western blotting, were significantly lower in knockout than in wildtype mice at 7 days after MI. Similarly, angiogenesis was decreased in the knockout mice after MI. Expression of both the endothelial marker CD-31 and ?-smooth muscle actin was markedly lower in the knockout than in wildtype mice at 7 days after MI. The knockout MI group had elevated levels of glycogen synthase kinase (GSK) 3? and decreased phosphatidylinositol 3-kinase (PI3K), phosphorylated serine/threonine protein kinase B (p-Akt), and cyclin D1, compared with the wildtype MI group. Similar effects were observed in experiments using cultured cardiomyocytes from neonatal wildtype or periostin knockout mice. Administration of SB216763, a GSK3? inhibitor, to knockout neonatal mice decreased myocardial fibrosis and increased angiogenesis in the infarcted area after MI.ConclusionAblation of periostin suppresses post-infarction myocardial regeneration by inhibiting the PI3K/GSK3?/cyclin D1 signalling pathway, indicating that periostin is essential for myocardial regeneration.
| S-EPMC5412017 | biostudies-literature
Project description:OBJECTIVES:Glycogen synthase kinase 3? (GSK-3?) inhibition has been reported to increase microvascular density and improve myocardial blood flow in a porcine model of chronic myocardial ischemia and metabolic syndrome. Inhibition of GSK-3? can also be cardioprotective by modulating fibrosis signaling and mitochondrial-induced apoptosis. We hypothesized GSK-3? inhibition would have a beneficial effect on myocardial fibrosis and oxidative stress in a porcine model of chronic myocardial ischemia and metabolic syndrome. METHODS:Pigs were fed a high fat diet for 4 weeks followed by placement of an ameroid constrictor to the left circumflex coronary artery. Three weeks later animals received either no drug or a GSK-3? inhibitor. The diets and placebo/GSK-3? inhibition were continued for an additional 5 weeks, the pigs were then euthanized, and the myocardial tissue was harvested. Collagen expression was analyzed via Picrosirius staining. Oxidative stress was analyzed via Oxyblot analysis. Protein expression was analyzed via Western blot. RESULTS:GSK-3? inhibition was associated with decreased collagen expression and oxidative stress in the ischemic and nonischemic myocardial tissue compared with control. There was a decrease in profibrotic proteins transforming growth factor-?, p-SMAD2/3, and matrix metalloproteinase-9, and in proapoptotic and oxidative stress proteins, apoptosis inducing factor, the cleaved caspase 3/caspase 3 protein ratio and phosphorylated myeloid cell leukemia sequence-1 in the GSK-3? inhibited group compared with the control. CONCLUSIONS:In the setting of metabolic syndrome and chronic myocardial ischemia, inhibition of GSK-3? decreases collagen formation and oxidative stress in myocardial tissue. GSK-3? inhibition might be having this beneficial effect by downregulating transforming growth factor-?/SMAD2/3 signaling and decreasing mitochondrial induced cellular stress.
| S-EPMC5960424 | biostudies-literature