Postnatal shifts in ischemic tolerance and cell survival signaling in murine myocardium

2013 ◽  
Vol 305 (10) ◽  
pp. R1171-R1181 ◽  
Author(s):  
Norman Y. Liaw ◽  
Louise See Hoe ◽  
Freya L. Sheeran ◽  
Jason N. Peart ◽  
John P. Headrick ◽  
...  
Keyword(s):  
Cell Survival ◽  
Connexin 43 ◽  
Glycogen Synthase ◽  
Ischemia Reperfusion ◽  
Hypoxia Inducible Factor ◽  
High Expression ◽  
Hsp27 Phosphorylation ◽  
Myocardial Stress ◽  
Survival Signaling ◽  
Gsk 3Β

The immature heart is known to be resistant to ischemia-reperfusion (I/R) injury; however, key proteins engaged in phospho-dependent signaling pathways crucial to cell survival are not yet defined. Our goal was to determine the postnatal changes in myocardial tolerance to I/R, including baseline expression of key proteins governing I/R tolerance and their phosphorylation during I/R. Hearts from male C57Bl/6 mice (neonates, 2, 4, 8, and 12 wk of age, n = 6/group) were assayed for survival signaling/effectors [Akt, p38MAPK, glycogen synthase kinase-3β (GSK-3β), heat shock protein 27 (HSP27), connexin-43, hypoxia-inducible factor-1α (HIF-1α), and caveolin-3] and regulators of apoptosis (Bax and Bcl-2) and autophagy (LC3B, Parkin, and Beclin1). The effect of I/R on ventricular function was measured in isolated perfused hearts from immature (4 wk) and adult (12 wk) mice. The neonatal myocardium exhibits a large pool of inactive Akt; high phospho-activation of p38MAPK, HSP27 and connexin-43; phospho-inhibition of GSK-3β; and high expression of caveolin-3, HIF-1α, LC3B, Beclin1, Bax, and Bcl-2. Immature hearts sustained less dysfunction and infarction following I/R than adults. Emergence of I/R intolerance in adult vs. immature hearts was associated with complex proteomic changes: decreased expression of Akt, Bax, and Bcl-2; increased GSK-3β, connexin-43, HIF-1α, LC3B, and Bax:Bcl-2; enhanced postischemic HIF-1α, caveolin-3, Bax, and Bcl-2; and greater postischemic GSK-3β and HSP27 phosphorylation. Neonatal myocardial stress resistance reflects high expression of prosurvival and autophagy proteins and apoptotic regulators. Notably, there is high phosphorylation of GSK-3β, p38MAPK, and HSP27 and low phosphorylation of Akt (high Akt “reserve”). Subsequent maturation-related reductions in I/R tolerance are associated with reductions in Akt, Bcl-2, LC3B, and Beclin1, despite increased expression and reduced phospho-inhibition of GSK-3β.

Abstract 340: Heat Shock Proteins HSP90 and HSP70 Mediate Opioid- and GSK3β-induced Cardioprotection

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Sarah K Jimenez ◽  
Bryce A Small ◽  
Anna K Hsu ◽  
Garrett J Gross ◽  
Eric R Gross
Keyword(s):  
Heat Shock ◽  
Heat Shock Proteins ◽  
Infarct Size ◽  
Glycogen Synthase ◽  
Ischemia Reperfusion ◽  
Myocardial Salvage ◽  
Sequence Motif ◽  
Protein Partners ◽  
Gsk 3Β ◽  
Shock Proteins

Previously, opioids were established to reduce myocardial injury in an ischemic preconditioning (IPC)-like manner, involving a central and downstream role of glycogen synthase kinase-3 beta (GSK-3β) inhibition. However, the mechanism of GSK-3β inhibition mediating cardioprotection and the protein partners involved has not been fully elucidated. Hence, we used a non-biased sequence scan of the proteome to determine potential GSK-3β protein partners and tested whether two candidate proteins, heat shock proteins (HSP) 70 and 90, are involved in the mechanism of opioid-induced cardioprotection. A non-biased BLAST search was performed for putative GSK-3β target substrates, based upon the sequence motif S/T-X-X-X-S/T. Approximately 700 proteins were identified to have this moiety, including many of the HSP protein class, including HSP70 and HSP90. To determine whether HSP70 or HSP90 are indeed important in opioid-induced cardioprotection, rats were subjected to an in vivo myocardial ischemia-reperfusion protocol consisting of 30 minutes of ischemia and 2 hours of reperfusion of the left anterior descending coronary artery followed by infarct size assessment. Either morphine (0.3mg/kg) or inhibition of GSK-3β using SB216763 (0.6mg/kg), reduced infarct size compared to control (42.21±1*% and 41.09±2*%, respectively versus control 60.38±1.2, *P<0.01). Inhibition of HSP70 using desoxysperguanalin (DSG), or HSP90 using radicicol (RAD), abrogated morphine-induced protection (56.09±2 and 58.64±1, respectively). Either DSG or RAD partially inhibited protection in the presence of GSK-3β (47.28±1.071 and 49.88±3.09). Our results suggest that morphine-induced cardioprotection occurs by a HSP70 and HSP90- dependent mechanism, with this HSP machinery partially required for GSK3β-inhibition-induced cardioprotection. Further understanding of this mechanism is important, considering many agents targeting HSP are currently in development as novel cancer treatments, which may have detrimental effects on the myocardial salvage mediated by opioids or by GSK3β-inhibition.

scholarly journals Glycogen Synthase Kinase 3 Phosphorylates Hypoxia-Inducible Factor 1α and Mediates Its Destabilization in a VHL-Independent Manner

2007 ◽  
Vol 27 (9) ◽  
pp. 3253-3265 ◽  
Author(s):  
Daniela Flügel ◽  
Agnes Görlach ◽  
Carine Michiels ◽  
Thomas Kietzmann
Keyword(s):  
Protein Kinase ◽  
Metabolic Diseases ◽  
Glycogen Synthase ◽  
Protein Kinase B ◽  
Hypoxia Inducible Factor ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Independent Manner ◽  
Von Hippel Lindau ◽  
Gsk 3Β

ABSTRACT Hypoxia-inducible transcription factor 1α (HIF-1α) is a key player in the response to hypoxia. Additionally, HIF-1α responds to growth factors and hormones which can act via protein kinase B (Akt). However, HIF-1α is not a direct substrate for this kinase. Therefore, we investigated whether the protein kinase B target glycogen synthase kinase 3 (GSK-3) may have an impact on HIF-1α. We found that the inhibition or depletion of GSK-3 induced HIF-1α whereas the overexpression of GSK-3β reduced HIF-1α. These effects were mediated via three amino acid residues in the oxygen-dependent degradation domain of HIF-1α. In addition, mutation analyses and experiments with von Hippel-Lindau (VHL)-defective cells indicated that GSK-3 mediates HIF-1α degradation in a VHL-independent manner. In line with these observations, the inhibition of the proteasome reversed the GSK-3 effects, indicating that GSK-3 may target HIF-1α to the proteasome by phosphorylation. Thus, the direct regulation of HIF-1α stability by GSK-3 may influence physiological processes or pathophysiological situations such as metabolic diseases or tumors.

Cardioprotection of the aged rat heart by GSK-3β inhibitor is attenuated: age-related changes in mitochondrial permeability transition pore modulation

2011 ◽  
Vol 300 (3) ◽  
pp. H922-H930 ◽  
Author(s):  
Jiang Zhu ◽  
Mario J. Rebecchi ◽  
Peter S. A. Glass ◽  
Peter R. Brink ◽  
Lixin Liu
Keyword(s):  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Glycogen Synthase ◽  
Ischemia Reperfusion ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Male Rats ◽  
Mitochondrial Permeability ◽  
Mptp Opening ◽  
Gsk 3Β

It is well established that inhibition of glycogen synthase kinase (GSK)-3β in the young adult myocardium protects against ischemia-reperfusion (I/R) injury through inhibition of mitochondrial permeability transition pore (mPTP) opening. Here, we investigated age-associated differences in the ability of GSK-3β inhibitor [SB-216763 (SB)] to protect the heart and to modulate mPTP opening during I/R injury. Fischer 344 male rats were assigned from their respective young or old age groups. Animals were subjected to 30 min ischemia following 120 min reperfusion to determine myocardial infarction (MI) size in vivo. Ischemic tissues were collected 10 min after reperfusion for nicotinamide adenine dinucleotide (NAD+) measurements and immunoblotting. In parallel experiments, ventricular myocytes isolated from young or old rats were exposed to oxidative stress through generation of reactive oxygen species (ROS), and mPTP opening times were measured by using confocal microscopy. Our results showed that SB decreased MI in young SB-treated rats compared with young untreated I/R animals, whereas SB failed to significantly affect MI in the old animals. SB also significantly increased GSK-3β phosphorylation in young rats, but phosphorylation levels were already highly elevated in old control groups. There were no significant differences observed between SB-treated and untreated old animals. NAD+levels were better maintained in young SB-treated animals compared with the young untreated group during I/R, but this relative improvement was not observed in old animals. SB also significantly prolonged the time to mPTP opening induced by ROS in young cardiomyocytes, but not in aged cardiomyocytes. These results demonstrate that this GSK-3β inhibitor fails to protect the aged myocardium in response to I/R injury or prevent mPTP opening following a rise in ROS and suggest that healthy aging alters mPTP regulation by GSK-3β.

A Review of Humoral Factors in Remote Preconditioning of the Heart

2019 ◽  
Vol 24 (5) ◽  
pp. 403-421 ◽  
Author(s):  
Sergey Y. Tsibulnikov ◽  
Leonid N. Maslov ◽  
Alexander S. Gorbunov ◽  
Nikita S. Voronkov ◽  
Alla A. Boshchenko ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Connexin 43 ◽  
Glycogen Synthase ◽  
Ischemia Reperfusion ◽  
Interleukin 10 ◽  
Convincing Evidence ◽  
Humoral Factors ◽  
Hydrophobic Peptides ◽  
Wide Range ◽  
In Series

A humoral mechanism of cardioprotection by remote ischemic preconditioning (RIP) has been clearly demonstrated in various models of ischemia–reperfusion including upper and lower extremities, liver, and the mesenteric and renal arteries. A wide range of humoral factors for RIP have been proposed including hydrophobic peptides, opioid peptides, adenosine, prostanoids, endovanilloids, endocannabinoids, calcitonin gene-related peptide, leukotrienes, noradrenaline, adrenomedullin, erythropoietin, apolipoprotein, A-I glucagon-like peptide-1, interleukin 10, stromal cell-derived factor 1, and microRNAs. Virtually, all of the components of ischemic preconditioning’s signaling pathway such as nitric oxide synthase, protein kinase C, redox signaling, PI3-kinase/Akt, glycogen synthase kinase β, ERK1/2, mitoKATPchannels, Connexin 43, and STAT were all found to play a role. The signaling pattern also depends on which remote vascular bed was subjected to ischemia and on the time between applying the rip and myocardial ischemia occurs. Because there is convincing evidence for many seemingly diverse humoral components in RIP, the most likely explanation is that the overall mechanism is complex like that seen in ischemic preconditioning where multiple components are both in series and in parallel and interact with each other. Inhibition of any single component in the right circumstance may block the resulting protective effect, and selectively activating that component may trigger the protection. Identifying the humoral factors responsible for RIP might be useful in developing drugs that confer RIP’s protection in a more comfortable and reliable manner.

scholarly journals Oleanolic Acid Alleviates Cerebral Ischemia/Reperfusion Injury via Regulation of the GSK-3β/HO-1 Signaling Pathway

2021 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Kaili Lin ◽  
Zhang Zhang ◽  
Zhu Zhang ◽  
Peili Zhu ◽  
Xiaoli Jiang ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Signaling Pathway ◽  
Oleanolic Acid ◽  
Ischemia Reperfusion Injury ◽  
Glycogen Synthase ◽  
Ischemia Reperfusion ◽  
Heme Oxygenase 1 ◽  
Therapeutic Effects ◽  
Gsk 3Β

Oleanolic acid (OA), a bioactive ingredient of Panax ginseng, exhibits neuroprotective pharmacological effects. However, the protective role of OA in cerebral ischemia and involved mechanisms remain unclear. This study attempted to explore the therapeutic effects of OA both in vitro and in vivo. OA attenuated cytotoxicity and overproduction of intracellular reactive oxygen species (ROS) by regulation of glycogen synthase kinase-3β (GSK-3β)/heme oxygenase-1 (HO-1) signal in oxygen-glucose deprivation/reoxygenation (OGD/R)-exposed SH-SY5Y cells. Additionally, OA administration significantly reduced the area of cerebral infarction and the neurological scores in the rat models of cerebral ischemia with middle cerebral artery occlusion (MCAO). The OA administration group showed a higher percentage of Nissl+ and NeuN+ cells, along with lower TUNEL+ ratios in the infarct area of MCAO rats. Moreover, OA administration reduced ROS production while it suppressed the GSK-3β activation and upregulated the HO-1 expression in infarcted tissue. Our results illustrated that OA significantly counteracted cerebral ischemia-mediated injury through antioxidant effects induced by the regulation of the GSK-3β/HO-1 signaling pathway, implicating OA as a promising neuroprotective drug for the therapy of ischemic stroke.

scholarly journals IGF-1 Signalling Regulates Mitochondria Dynamics and Turnover through a Conserved GSK-3β–Nrf2–BNIP3 Pathway

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 147 ◽  
Author(s):  
Sarah Riis ◽  
Joss B. Murray ◽  
Rosemary O’Connor
Keyword(s):  
Mitochondrial Biogenesis ◽  
Glycogen Synthase ◽  
Mitochondrial Dynamics ◽  
Hypoxia Inducible Factor ◽  
Protective Role ◽  
Null Mouse ◽  
Related Factor ◽  
Mitochondrial Stress ◽  
Cellular Capacity ◽  
Gsk 3Β

The Insulin-like Growth Factor I (IGF-1) signalling pathway is essential for cell growth and facilitates tumourogenic processes. We recently reported that IGF-1 induces a transcriptional programme for mitochondrial biogenesis, while also inducing expression of the mitophagy receptor BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), suggesting that IGF-1 has a key mitochondria-protective role in cancer cells. Here, we investigated this further and delineated the signaling pathway for BNIP3 induction. We established that IGF-1 induced BNIP3 expression through a known AKT serine/threonine kinase 1 (AKT)-mediated inhibitory phosphorylation on Glycogen Synthase Kinase-3β (GSK-3β), leading to activation of Nuclear Factor Erythroid 2-related Factor 2 (NFE2L2/Nrf2) and acting through the downstream transcriptional regulators Nuclear Respiratory Factor-1 (NRF1) and Hypoxia-inducible Factor 1 subunit α (HIF-1α). Suppression of IGF-1 signaling, Nrf2 or BNIP3 caused the accumulation of elongated mitochondria and altered the mitochondrial dynamics. IGF-1R null Mouse Embryonic Fibroblasts (MEFs) were impaired in the BNIP3 expression and in the capacity to mount a cell survival response in response to serum deprivation or mitochondrial stress. IGF-1 signalling enhanced the cellular capacity to induce autophagosomal turnover in response to activation of either general autophagy or mitophagy. Overall, we conclude that IGF-1 mediated a mitochondria-protective signal that was coordinated through the cytoprotective transcription factor Nrf2. This pathway coupled mitochondrial biogenesis with BNIP3 induction, and increased the cellular capacity for autophagosome turnover, whilst enhancing survival under conditions of metabolic or mitochondrial stress.

scholarly journals Perioperative Dexmedetomidine attenuates brain ischemia reperfusion injury possibly via up-regulation of astrocyte Connexin 43

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaoyang Zheng ◽  
Xiaoying Cai ◽  
Fang Ye ◽  
Ying Li ◽  
Qin Wang ◽  
...  
Keyword(s):  
Brain Ischemia ◽  
Connexin 43 ◽  
Ischemia Reperfusion ◽  
Arterial Occlusion ◽  
Brain Lesions ◽  
Neurological Injury ◽  
Inflammatory Factors ◽  
Tnf Α ◽  
Gsk 3Β ◽  
Cerebral Arterial Occlusion

Abstract Background Astrocyte Connexin 43 (Cx43) is essential for the trophic and protective support of neurons during brain ischemia reperfusion (I/R) injury. It is believed that dexmedetomidine participates in Cx43-mediated effects. However, its mechanisms remained unclear. This study aims to address the relationship and regulation among them. Methods Adult male Sprague-Dawley rats were allocated to the 90-min right middle cerebral arterial occlusion with or without dexmedetomidine pretreatment (5 μg/kg). Neurological functions were evaluated and brain lesions, as well as inflammatory factors (IL-1β, IL-6, TNF-α), were assessed. Ischemic penumbral cortex was harvested to determine the expression of astrocyte Cx43. Primary astrocytes were cultured to evaluate the effect of dexmedetomidine on Cx43 after oxygen-glucose deprivation. Results Dexmedetomidine pretreatment attenuated neurological injury, brain lesions and expression of inflammatory factors (IL-1β, IL-6, TNF-α) after brain ischemia (P < 0.05). Astrocyte Cx43 was down-regulated by brain I/R injury, both in vivo and in vitro, which were reversed by dexmedetomidine (P < 0.05). This effect was mediated by the phosphorylation of Akt and GSK-3β. Further studies with LY294002 (PI3K inhibitor) or SB216763 (GSK-3β inhibitor) confirmed the effect of dexmedetomidine on astrocyte Cx43. Conclusions Perioperative dexmedetomidine administration attenuates neurological injury after brain I/R injury, possibly through up-regulation of astrocyte Cx43. Activation of PI3K-Akt-GSK-3β pathway might contribute to this protective effect.

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