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Liu Q, Telezhkin V, Jiang W, Gu Y, Wang Y, Hong W, Tian W, Yarova P, Zhang G, Lee SMY, Zhang P, Zhao M, Allen ND, Hirsch E, Penninger J, Song B. Electric field stimulation boosts neuronal differentiation of neural stem cells for spinal cord injury treatment via PI3K/Akt/GSK-3β/β-catenin activation. Cell Biosci 2023; 13:4. [PMID: 36624495 PMCID: PMC9830810 DOI: 10.1186/s13578-023-00954-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/03/2023] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Neural stem cells (NSCs) are considered as candidates for cell replacement therapy in many neurological disorders. However, the propensity for their differentiation to proceed more glial rather than neuronal phenotypes in pathological conditions limits positive outcomes of reparative transplantation. Exogenous physical stimulation to favor the neuronal differentiation of NSCs without extra chemical side effect could alleviate the problem, providing a safe and highly efficient cell therapy to accelerate neurological recovery following neuronal injuries. RESULTS With 7-day physiological electric field (EF) stimulation at 100 mV/mm, we recorded the boosted neuronal differentiation of NSCs, comparing to the non-EF treated cells with 2.3-fold higher MAP2 positive cell ratio, 1.6-fold longer neuronal process and 2.4-fold higher cells ratio with neuronal spontaneous action potential. While with the classical medium induction, the neuronal spontaneous potential may only achieve after 21-day induction. Deficiency of either PI3Kγ or β-catenin abolished the above improvement, demonstrating the requirement of the PI3K/Akt/GSK-3β/β-catenin cascade activation in the physiological EF stimulation boosted neuronal differentiation of NSCs. When transplanted into the spinal cord injury (SCI) modelled mice, these EF pre-stimulated NSCs were recorded to develop twofold higher proportion of neurons, comparing to the non-EF treated NSCs. Along with the boosted neuronal differentiation following transplantation, we also recorded the improved neurogenesis in the impacted spinal cord and the significantly benefitted hind limp motor function repair of the SCI mice. CONCLUSIONS In conclusion, we demonstrated physiological EF stimulation as an efficient method to boost the neuronal differentiation of NSCs via the PI3K/Akt/GSK-3β/β-catenin activation. Pre-treatment with the EF stimulation induction before NSCs transplantation would notably improve the therapeutic outcome for neurogenesis and neurofunction recovery of SCI.
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Affiliation(s)
- Qian Liu
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China. .,School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, CF14 4XY, UK.
| | - Vsevolod Telezhkin
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,School of Dental Sciences, Farmington Place, Newcastle University, Newcastle Upon Tyne, NE2 4BW, UK
| | - Wenkai Jiang
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, CF14 4XY, UK.,State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases, School of Stomatology, Fourth Military Medical University, Xi'an, 710032, China
| | - Yu Gu
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, CF14 4XY, UK
| | - Yan Wang
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Wei Hong
- The Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institution, Shenzhen, China
| | - Weiming Tian
- Bio-X Centre, School of Life Science and Technology, Harbin Institute of Technology, Harbin, 150080, China
| | - Polina Yarova
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.,School of Dental Sciences, Farmington Place, Newcastle University, Newcastle Upon Tyne, NE2 4BW, UK
| | - Gaofeng Zhang
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, CF14 4XY, UK
| | - Simon Ming-Yuen Lee
- State Key Laboratory of Quality Research in Chinese Medicine and, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Peng Zhang
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Min Zhao
- Department of Ophthalmology and Vision Science, University of California at Davis, Sacramento, CA, 95616, USA
| | - Nicholas D Allen
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK
| | - Emilio Hirsch
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Josef Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences, VBC - Vienna BioCenter, Vienna, Austria.,Department of Medical Genetics, Life Sciences Institute, University of British Columbia, Vancouver, Canada
| | - Bing Song
- Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China. .,School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, CF14 4XY, UK.
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Liu Y, Deng M, Wang Y, Wang H, Li C, Wu H. Identification of differentially expressed genes and biological pathways in para-carcinoma tissues of HCC with different metastatic potentials. Oncol Lett 2020; 19:3799-3814. [PMID: 32382332 PMCID: PMC7202278 DOI: 10.3892/ol.2020.11493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 01/30/2020] [Indexed: 12/02/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a malignant tumor with extensive metastasis. Changes in the tumor microenvironment provide favorable conditions for tumor metastasis. However, the role of changes to the tumor microenvironment in HCC metastasis is yet to be elucidated. The Gene Expression Omnibus expression profile GSE5093 consists of 20 noncancerous tissues surrounding HCC tissues, including 9 metastasis-inclined microenvironment samples with detectable metastases and 11 metastasis-averse microenvironment samples without detectable metastases. The present study assessed 35 HCC samples to verify the results of chip analysis. In total, 712 upregulated and 459 downregulated genes were identified, with 1,033 nodes, 7,589 edges and 10 hub genes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the differentially expressed genes were significantly enriched in ‘cell-cell adhesion’, ‘cell proliferation’ and ‘protein binding’. The top 10 hub genes were identified via a protein-protein interaction analysis. The 3 most significant modules were identified from the protein-protein network. Moreover, an association between hub genes and patient prognosis was identified. In conclusion, these candidate genes and pathways may help elucidate the mechanisms underlying HCC metastasis and identify more options for targeted therapy.
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Affiliation(s)
- Yan Liu
- Department of Gastroenterology, The Chengdu Fifth People's Hospital, Chengdu, Sichuan 611130, P.R. China
| | - Mingming Deng
- Department of Gastroenterology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Yimeng Wang
- Department of Gastroenterology, The Chengdu Fifth People's Hospital, Chengdu, Sichuan 611130, P.R. China
| | - Huiqin Wang
- Department of Gastroenterology, The Chengdu Fifth People's Hospital, Chengdu, Sichuan 611130, P.R. China
| | - Changping Li
- Department of Gastroenterology, The Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Hao Wu
- Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
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Abstract
Objective: Omentin is a recently identified novel adipocytokine mainly expressed in the epicardial adipose tissue. Although it has favorable effects on cardiovascular disease, the impact of omentin on the hearts is still an understudied issue. The aim of the present study was to investigate the possible effects of omentin on isolated rat heart. Methods: Using the Langendorff method, 28 adult male Sprague–Dawley rat hearts were isolated and perfused with modified Krebs–Henseleit solution (mK–Hs). Concentrations of 100, 200, and 400 ng/mL omentin were given to the hearts for 30 min. The control group (n=7) was perfused with mK–Hs alone. Gene expressions in the left ventricle tissue were determined by real-time polymerase chain reaction. Left ventricular cyclic adenosine monophosphate and cyclic guanosine monophosphate (cGMP) concentrations were determined by using enzyme-linked immunosorbent assay. Results: All concentrations of omentin significantly decreased left ventricular developed pressure and maximal rate of pressure development that are the indexes of cardiac contractility. At the same time, omentin decreased both phosphoinositide 3-kinase γ (PI3Kγ) and sarcolemmal L-type Ca2+ channel (CaV1.2) mRNA levels. Moreover, this peptide at concentrations of 200 and 400 ng/mL increased endothelial nitric oxide synthase (eNOS) mRNA. Furthermore, concentrations of 200 and 400 ng/mL omentin increased the amount of cGMP. Conclusion: We conclude that acute omentin treatment decreases cardiac contractility. Elevated eNOS mRNA and cGMP levels with reduced CaV1.2 mRNA are likely to lead to negative inotropy.
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Abstract
The phosphoinositide 3-kinase (PI3K) family includes eight distinct catalytic subunits and seven regulatory subunits. Only two PI3Ks are directly regulated downstream from G protein-coupled receptors (GPCRs): the class I enzymes PI3Kβ and PI3Kγ. Both enzymes produce phosphatidylinositol 3,4,5-trisposphate in vivo and are regulated by both heterotrimeric G proteins and small GTPases from the Ras or Rho families. However, PI3Kβ is also regulated by direct interactions with receptor tyrosine kinases (RTKs) and their tyrosine phosphorylated substrates, and similar to the class II and III PI3Ks, it binds activated Rab5. The unusually complex regulation of PI3Kβ by small and trimeric G proteins and RTKs leads to a rich landscape of signaling responses at the cellular and organismic levels. This review focuses first on the regulation of PI3Kβ activity in vitro and in cells, and then summarizes the biology of PI3Kβ signaling in distinct tissues and in human disease.
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Affiliation(s)
- Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
- Correspondence: Anne R. Bresnick, PhD, or Jonathan M. Backer, MD, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461. E-mail: or
| | - Jonathan M Backer
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York
- Correspondence: Anne R. Bresnick, PhD, or Jonathan M. Backer, MD, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461. E-mail: or
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Perrotta M, Lembo G, Carnevale D. The Multifaceted Roles of PI3Kγ in Hypertension, Vascular Biology, and Inflammation. Int J Mol Sci 2016; 17:E1858. [PMID: 27834808 DOI: 10.3390/ijms17111858] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 10/22/2016] [Accepted: 11/03/2016] [Indexed: 12/12/2022] Open
Abstract
PI3Kγ is a multifaceted protein, crucially involved in cardiovascular and immune systems. Several studies described the biological and physiological functions of this enzyme in the regulation of cardiovascular system, while others stressed its role in the modulation of immunity. Although PI3Kγ has been historically investigated for its role in leukocytes, the last decade of research also dedicated efforts to explore its functions in the cardiovascular system. In this review, we report an overview recapitulating how PI3Kγ signaling participates in the regulation of vascular functions involved in blood pressure regulation. Moreover, we also summarize the main functions of PI3Kγ in immune responses that could be potentially important in the interaction with the cardiovascular system. Considering that vascular and immune mechanisms are increasingly emerging as intertwining players in hypertension, PI3Kγ could be an intriguing pathway acting on both sides. The availability of specific inhibitors introduces a perspective of further translational research and clinical approaches that could be exploited in hypertension.
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Trenkwalder T, Deindl E, Bongiovanni D, Lee S, Schunkert H, Kupatt C, Hinkel R. Thymosin-β4-mediated therapeutic neovascularization: role of the PI3K/AKT pathway. Expert Opin Biol Ther 2015; 15 Suppl 1:S175-85. [PMID: 25652683 DOI: 10.1517/14712598.2015.1011122] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES Thymosin β4 (Tβ4) is known to have pro-angogenic abilities in vitro and in vivo, and its cardioprotective effect is PI3/AKT-dependent. Tβ4-induced vessel formation requires transcriptional activation via the MRTF/SRF pathway. However, the relevance of PI3/AKT signaling for Tβ4-induced angiogenesis remains unclear. Here, we analyzed the PI3K/AKT cascade after Tβ4 transduction in models of chronic hindlimb ischemia. METHODS Tube formation assays of endothelial cells transfected with Tβ4 ± AKT-dn or PI3Kα/Rho inhibition were performed. In mice, rAAV.Tβ4 was injected (intramuscular [i.m.]) 14 days before femoral artery ligation. In addition, either rAAV.AKT-dn was co-applied or Rho/PI3K/AKT pathways were inhibited. Capillary density and hindlimb perfusion were obtained. In rabbits, chronic ischemia was induced by femoral artery excision and subsequent i.m. injection of rAAV.Tβ4 ± rAAV.AKT-dn. Analyses of capillary density, collateral formation and perfusion were performed. RESULTS Tβ4-induced ring formation was blunted by inhibiting the Rho-kinase (ROCK) or the PI3K/AKT pathway. In vivo, Tβ4 transduction induced angiogenesis and perfusion, an effect abrogated by inhibition of Rho-signaling, or PI3Kα/AKT. In the rabbit model, inhibition of AKT in the lower limb not only abolished angiogenesis but also collateral formation. CONCLUSION Tβ4 requires PI3Kα/AKT pathway signaling for induction of therapeutic neovascularization in ischemic limb disease.
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Affiliation(s)
- Teresa Trenkwalder
- Deutsches Herzzentrum München, Technische Universität , Munich , Germany
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Chen S, Wu S, Li W, Chen X, Dong X, Tan G, Zhang H, Hong Z, Zhu Z, Chai Y. Investigation of the therapeutic effectiveness of active components in Sini decoction by a comprehensive GC/LC-MS based metabolomics and network pharmacology approaches. Mol Biosyst 2014; 10:3310-21. [PMID: 25315049 DOI: 10.1039/c4mb00048j] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
As a classical formula, Sini decoction (SND) has been fully proved to be clinically effective in treating doxorubicin (DOX)-induced cardiomyopathy. Current chemomics and pharmacology proved that the total alkaloids (TA), total gingerols (TG), total flavones and total saponins (TFS) are the major active ingredients of Aconitum carmichaelii, Zingiber officinale and Glycyrrhiza uralensis in SND respectively. Our animal experiments in this study demonstrated that the above active ingredients (TAGFS) were more effective than formulas formed by any one or two of the three individual components and nearly the same as SND. However, very little is known about the action mechanisms of TAGFS. Thus, this study aimed to use for the first time the combination of GC/LC-MS based metabolomics and network pharmacology for solving this problem. By metabolomics, it was found that TAGFS worked by regulating six primary pathways. Then, network pharmacology was applied to search for specific targets. 17 potential cardiovascular related targets were found through molecular docking, 11 of which were identified by references, which demonstrated the therapeutic effectiveness of TAGFS using network pharmacology. Among these targets, four targets, including phosphoinositide 3-kinase gamma, insulin receptor, ornithine aminotransferase and glucokinase, were involved in the TAGFS regulated pathways. Moreover, phosphoinositide 3-kinase gamma, insulin receptor and glucokinase were proved to be targets of active components in SND. In addition, our data indicated TA as the principal ingredient in the SND formula, whereas TG and TFS served as adjuvant ingredients. We therefore suggest that dissecting the mode of action of clinically effective formulae with the combination use of metabolomics and network pharmacology may be a good strategy.
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Affiliation(s)
- Si Chen
- School of Pharmacy, Second Military Medical University, 325 Guohe Road, Shanghai, 200433, China.
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Hsieh DJY, Huang CY, Pai P, Wang SGP, Tsai YL, Li CN, Kuo WW, Huang CY. Prolactin protects cardiomyocytes against intermittent hypoxia-induced cell damage by the modulation of signaling pathways related to cardiac hypertrophy and proliferation. Int J Cardiol 2014; 181:255-66. [PMID: 25531577 DOI: 10.1016/j.ijcard.2014.11.154] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/18/2014] [Accepted: 11/22/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES Prolactin (PRL) is a multifunctional hormone that influences multiple physiological processes. It has been shown to have a protective effect on the cardiovascular system; however, the mechanisms of this effect are poorly understood. The purpose of the study was to elucidate the role of PRL in intermittent hypoxia (IH)-induced apoptosis in the cardiovascular system. METHOD AND RESULTS We established a hyperprolactinemic rat model by implanting two anterior pituitary (AP) glands into the renal capsule of male Sprague-Dawley rats. The rats were kept under normoxic conditions for 4weeks after implantation in order to reach the expression plateau of PRL in the plasma, and then treated with IH for 7 or 14days. Their hearts were then removed for histological and protein expression analyses. Cerebral cortex (CX)-grafted control rats challenged with IH displayed unique phenotypes such as a thicker heart wall, an abnormal myocardial architecture and an increased interstitial space of the left ventricle. They exhibited reduced expressions of p-JAK2, p-STAT5, cell cycle-dependent proteins (cyclin D1, cyclin E and cyclin A), IGF-IRα, PI3Kα, p-AKT and p-ERK1/2 in cardiomyocytes at 7days. CONCLUSIONS Our comprehensive analysis suggested that high plasma PRL can protect rat cardiomyocytes against IH through (1) the p-JAK2 and p-STAT5 pathways for transient cell proliferation, (2) the PI3Kα/AKT and MAPK survival pathways through IGF-I, and (3) the downregulation of IGF-II and ERK5, which inhibit cell hypertrophy.
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Affiliation(s)
- Dennis Jine-Yuan Hsieh
- School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan; Clinical Laboratory, Chung Shan Medical University Hospital, Taichung 402, Taiwan
| | - Chih-Yang Huang
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan
| | - Peiying Pai
- Division of Cardiology, China Medical University Hospital, Taichung, Taiwan
| | - Shyi-Gang P Wang
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan; Department of Physiology, National Yang-Ming University, Taipei, Taiwan
| | - Ying-Lan Tsai
- Athletic Training and Health Department, National Taiwan Sport University, Taoyuan 333, Taiwan
| | - Chia-Ning Li
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan
| | - Wei-Wen Kuo
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - Chih-Yang Huang
- Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan; Graduate Institute of Chinese Medical Science, China Medical University, Taichung, Taiwan; Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan.
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Batchu SN, Chaudhary KR, El-Sikhry H, Yang W, Light PE, Oudit GY, Seubert JM. Role of PI3Kα and sarcolemmal ATP-sensitive potassium channels in epoxyeicosatrienoic acid mediated cardioprotection. J Mol Cell Cardiol 2012; 53:43-52. [PMID: 22561102 DOI: 10.1016/j.yjmcc.2012.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 04/09/2012] [Accepted: 04/16/2012] [Indexed: 10/28/2022]
Abstract
AIMS Epoxyeicosatrienoic acids (EETs) are cytochrome P450 epoxygenase metabolites of arachidonic acid that have known cardioprotective properties. While the mechanism(s) remains unknown, evidence suggests that phosphoinositide 3-kinase (PI3K) and sarcolemmal ATP-sensitive potassium channels (pmK(ATP)) are important. However the role of specific PI3K isoforms and corresponding intracellular mechanisms remains unknown. METHODS AND RESULTS To study this, mice hearts were perfused in Langendorff mode for 40 min of baseline and subjected to 20 or 30 min of global no-flow ischemia followed by 40 min of reperfusion. C57BL6 mice perfused with 11,12-EET (1 μM) had improved postischemic recovery, whereas co-perfusion with PI3Kα inhibitor, PI-103 (0.1 μM), abolished the EET-mediated effect. In contrast, blocking of PI3Kβ or PI3Kγ isoforms failed to inhibit EET-mediated cardioprotection. In addition to the improved post-ischemic recovery, increased levels of p-Akt, decreased calcineurin activity and decreased translocation of proapoptotic protein BAD to mitochondria were noted in EET-treated hearts. Perfusion of 11,12-EET to Kir6.2 deficient mice (pmK(ATP)) failed to improve postischemic recovery, decrease calcineurin activity and translocation of proapoptotic protein BAD, however increased levels of p-Akt were still observed. Patch-clamp experiments demonstrated that 11,12-EET could not activate pmK(ATP) currents in myocytes pre-treated with PI-103. Mechanistic studies in H9c2 cells demonstrate that 11,12-EET limits anoxia-reoxygenation triggered Ca(2+) accumulation and maintains mitochondrial ΔΨm compared to controls. Both PI-103 and glibenclamide (10 μM, pmK(ATP) inhibitor) abolished EET cytoprotection. CONCLUSION Together our data suggest that EET-mediated cardioprotection involves activation of PI3Kα, upstream of pmK(ATP), which prevents Ca(2+) overload and maintains mitochondrial function.
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Affiliation(s)
- Sri N Batchu
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
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Alvin Z, Laurence GG, Coleman BR, Zhao A, Hajj-Moussa M, Haddad GE. Regulation of L-type inward calcium channel activity by captopril and angiotensin II via the phosphatidyl inositol 3-kinase pathway in cardiomyocytes from volume-overload hypertrophied rat hearts. Can J Physiol Pharmacol 2012; 89:206-15. [PMID: 21423294 DOI: 10.1139/y11-011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Heart failure can be caused by pro-hypertrophic humoral factors such as angiotensin II (Ang II), which regulates protein kinase activities. The intermingled responses of these kinases lead to the early compensated cardiac hypertrophy, but later to the uncompensated phase of heart failure. We have shown that although beneficial, cardiac hypertrophy is associated with modifications in ion channels that are mainly mediated through mitogen-activated protein (MAP) kinase and phosphatidylinositol 3-kinase (PI3K) activation. This study evaluates the control of L-type Ca(2+) current (I(Ca,L)) by the Ang II/PI3K pathway in hypertrophied ventricular myocytes from volume-overload rats using the perforated patch-clamp technique. To assess activation of the I(Ca,L) in cardiomyocytes, voltages of 350 ms in 10 mV increments from a holding potential of -85 mV were applied to cardiocytes, with a pre-pulse to -45 mV for 300 ms. Volume overload-induced hypertrophy reduces I(Ca,L), whereas addition of Ang II alleviates the hypertrophic-induced decrease in a PI3K-dependent manner. Acute administration of Ang II (10(-6) mol/L) to normal adult cardiomyocytes had no effect; however, captopril reduced their basal I(Ca,L). In parallel, captopril regressed the hypertrophy and inverted the Ang II effect on I(Ca,L) seemingly through a PI3K upstream effector. Thus, it seems that regression of cardiac hypertrophy by captopril improved I(Ca,L) partly through PI3K.
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Affiliation(s)
- Zikiar Alvin
- Department of Physiology and Biophysics, College of Medicine, Howard University, WA 20059, USA
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Li T, Kilic A, Wei X, Wu C, Schwartzbauer G, Yankey GK, DeFilippi C, Bond M, Wu ZJ, Griffith BP. Regional imbalanced activation of the calcineurin/BAD apoptotic pathway and the PI3K/Akt survival pathway after myocardial infarction. Int J Cardiol 2013; 166:158-65. [PMID: 22088220 DOI: 10.1016/j.ijcard.2011.10.107] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 09/23/2011] [Accepted: 10/18/2011] [Indexed: 01/17/2023]
Abstract
BACKGROUND The underlying molecular mechanisms of the remodeling after myocardial infarction (MI) remain unclear. The purpose of this study was to investigate the role of a survival pathway (PI3K/Akt) and an apoptosis pathway (calcineurin/BAD) in the remodeling after MI in a large animal model. METHODS Ten Dorset hybrid sheep underwent 25% MI in the left ventricle (LV, n=10). Five sheep were used as sham control. The regional strain was calculated from sonomicrometry. Apoptosis and the activation of the PI3K/Akt and calcineurin/BAD pathways were evaluated in the non-ischemic adjacent zone and the remote zone relative to infarct by immunoblotting, immunoprecipitation, and immunofluorescence staining. RESULTS Dilation and dysfunction of LV were present at 12 weeks after MI. The regional strain in the adjacent zone was significantly higher than in the remote zone at 12 weeks (36.6 ± 4.0% vs 9.5 ± 3.6%, p<0.05). Apoptosis was more severe in the adjacent zone than in the remote zone. The PI3K/Akt and calcineurin/BAD pathways were activated in the adjacent zone. Dephosphorylation and translocation of BAD were evident in the adjacent zone. Regional correlation between the strain and the expression of calcineurin/BAD indicated that the activation was strain-related (R(2)=0.46, 0.48, 0.39 for calcineurin, BAD, mitochondrial BAD, respectively, p<0.05). CONCLUSIONS The PI3K/Akt survival and calcineurin/BAD apoptotic pathways were concomitantly activated in the non-ischemic adjacent zone after MI. The calcineurin/BAD pathway is strain related and its imbalanced activation may be one of the causes of progressive remodeling after MI.
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Abstract
Glitazones (thiazolidinediones) are drugs used for diabetes mellitus type 2. By binding to peroxisome proliferator-activated receptor γ (PPARγ) they modulate transcription of genes of carbohydrate and lipid metabolism. Through PPARγ stimulation, however, glitazones also affect other genes, encompassing inflammation, cell growth and differentiation, angiogenesis, which broads their therapeutic potential. The gene expression profile induced by each glitazone shows peculiarities, which may affect its benefit/risk balance; indeed, troglitazone and rosiglitazone have been associated with liver failure and coronary disease, respectively; whether or not these severe adverse effects are solely related to PPARγ remains yet unclear, since glitazones exert also PPARγ-independent effects. Glitazone chemistry serves as scaffold for synthesizing new compounds with PPARγ-independent pharmacological properties and we report here a preliminary observation of inhibition of vasoconstriction by troglitazone in isolated vessels, an effect that appears fast, reversible, and PPARγ-independent. Pleiotropic effects of glitazones need specific attention in terms of drug safety, but also provide basis for drug development and novel experimental therapeutics.
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Affiliation(s)
- Salvatore Salomone
- Department of Clinical and Molecular Biomedicine, Catania University Catania, Italy
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Braz JC, Gill RM, Corbly AK, Jones BD, Jin N, Vlahos CJ, Wu Q, Shen W. Selective activation of PI3Kalpha/Akt/GSK-3beta signalling and cardiac compensatory hypertrophy during recovery from heart failure. Eur J Heart Fail 2010; 11:739-48. [PMID: 19633101 DOI: 10.1093/eurjhf/hfp094] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
AIMS Activation of phosphoinositide-3 kinase (PI3K) is essential for cell growth, relating to adaptive and maladaptive cardiac hypertrophy. This longitudinal canine study was designed to investigate the role of PI3Kalpha and PI3Kgamma in cardiac remodelling during congestive heart failure (CHF) and cardiac recovery (CR). METHODS AND RESULTS All dogs were surgically instrumented. Congestive heart failure was induced by cardiac pacing for 3-4 weeks and CR was allowed by terminating pacing for 5-6 weeks after induction of HF. Control dogs had sham surgery, but did not undergo pacing. Left ventricular (LV) contractile function was depressed in CHF and restored to 80-90% of the normal level in CR, with a 25% increase in LV weight. The expression of PI3Kgamma was increased four-fold in CHF, but returned to control levels in CR. In contrast, the expression of PI3Kalpha in CHF was not different from that in controls, but increased three-fold in CR and was accompanied by increases in phosphorylation of Akt (five-fold), GSK-3beta (five-fold), beta-catenin (three-fold), mTOR (two-fold), and P70S6K (two-fold). CONCLUSION Our results indicate that PI3K isoforms are regulated differently during the course of CHF/CR and that the selective activation of PI3Kalpha, through Akt, GSK-3beta, and mTOR signalling pathways, may be involved in the development of cardiac compensatory hypertrophy and functional restoration.
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Affiliation(s)
- Julian C Braz
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
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Martin EL, Souza DG, Fagundes CT, Amaral FA, Assenzio B, Puntorieri V, Del Sorbo L, Fanelli V, Bosco M, Delsedime L, Pinho JF, Lemos VS, Souto FO, Alves-Filho JC, Cunha FQ, Slutsky AS, Ruckle T, Hirsch E, Teixeira MM, Ranieri VM. Phosphoinositide-3 Kinase γ Activity Contributes to Sepsis and Organ Damage by Altering Neutrophil Recruitment. Am J Respir Crit Care Med 2010; 182:762-73. [DOI: 10.1164/rccm.201001-0088oc] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Recently, it has been reported that some members of the PI3K family might have a "double identity"; in other words, PI3K have been found to act not only as classical kinases, but also as scaffolding proteins. Until now, the use of knockout mice has been considered sufficient to model the effects of PI3K inhibition and to predict the outcome of anti-PI3K pharmacological treatments by observing the resulting phenotypes. These studies supported the view that PI3K may represent promising pharmacological targets for cancer and inflammation. However, in selected cases, different experimental strategies of gene targeting of the same locus have resulted in distinct phenotypes. This demonstrates that "knocking-out" a gene is not necessarily equivalent to "knocking-in" an inactivating point mutation (Vanhaesebroeck et al. in Cell 118:274-276, 2004). Specifically, knockout and kinase-dead models have led to the discovery that PI3Kγ and β may act independently of their kinase activity, likely as adaptor proteins.
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Affiliation(s)
- Carlotta Costa
- Molecular Biotechnology Center, University of Torino, Torino, Italy
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16
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Abstract
Mortality in children with sepsis is most often related to diminished cardiac output with cardiovascular collapse, resulting in impaired oxygen delivery and, ultimately, end-organ failure. Although cardiovascular "collapse" is commonly observed in individuals with septic shock, the hemodynamic causes of this differ greatly. In children, intrinsic myocardial dysfunction is most commonly present, whereas the systemic vascular resistance is typically high. This pattern is distinct from adults with sepsis where the principal hemodynamic profile shows elevated cardiac output, but substantially reduced systemic vascular resistance. Various studies support the concept that myocardial dysfunction, as occurs in pediatric septic patients, is due to intrinsic abnormalities in cardiomyocyte function and is not related to hypoperfusion as a result of low systemic vascular resistance. Importantly, when examined more closely, data from adults with septic shock also reveal that intrinsic myocardial dysfunction may play a larger role than previously appreciated. As a result, cardiovascular support, especially in pediatric sepsis, requires a treatment strategy directed at the underlying mechanism(s) responsible for this dysfunction. Thus, it is imperative to gain a better understanding of the myocardial derangements that occur during sepsis to identify targets that will ultimately influence the management of children with septic shock and favorably alter the associated mortality. We hypothesize that key signaling pathways that control myocardial calcium flux, regulated to key kinases and phosphatases, influence myocyte contractility in sepsis. Thus, we review the data relevant to the sepsis-induced intracellular alterations in calcium flux in the cardiomyocyte, with an emphasis on changes in the phosphorylation state of the contractile proteins regulated by the balance between kinases and phosphatases. We believe that therapies modulating the activity of these key proteins may provide an improvement in calcium handling and myocardial contractility and alter the clinical outcomes in sepsis.
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Ruan H, Li J, Ren S, Gao J, Li G, Kim R, Wu H, Wang Y. Inducible and cardiac specific PTEN inactivation protects ischemia/reperfusion injury. J Mol Cell Cardiol 2008; 46:193-200. [PMID: 19038262 DOI: 10.1016/j.yjmcc.2008.10.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 10/03/2008] [Accepted: 10/22/2008] [Indexed: 10/21/2022]
Abstract
PTEN is a dual lipid and protein phosphatase that antagonizes PI3K as well as other signaling pathways and regulates cellular survival and growth. However, its potential role in cardiac ischemia/reperfusion injury remains unknown. We established a transgenic mouse model with inducible and cardiac specific deletion of Pten gene (Pten(CKO)) in adult heart via tamoxifen dependent Cre-loxP mediated DNA recombination. 3 weeks after tamoxifen induced PTEN inactivation, elevated PI3K activity was observed in the Pten(CKO) hearts as determined from downstream AKT signaling. No significant differences in cardiac function as well as chamber size were observed between Pten(CKO) and Control animals based on echocardiography. In response to 30 min ischemia followed by 120 min reperfusion in Langendorff preparations, Pten(CKO) hearts developed significantly better function recovery than Control animals. At 60 min post reperfusion, the recovery of LVDP reached 77.9% of pre-ischemia basal in Pten(CKO) hearts vs 44.2% of Control (p<0.01). Consistent with the observed functional improvement, TTC staining revealed a significant reduction in infarct size in Pten(CKO) hearts compared with Control (24.2% vs 39.7%, p<0.05). Pten(CKO) hearts had significantly fewer apoptosis positive cardiomyocytes after I/R injury as identified by TUNEL staining. Furthermore, ERK activity and BCL-2 expression were not affected at basal but became significantly higher after ischemia/reperfusion in Pten(CKO) hearts. These data indicate that PTEN may play a role in ischemia/reperfusion injury by inhibiting anti-apoptotic survival signals. Inhibiting PTEN may serve as a potential approach to exert cardiac protection against ischemia reperfusion injury.
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Affiliation(s)
- Hongmei Ruan
- Department of Anesthesiology, University of California, Los Angeles, Los Angeles, CA 90095-1735, USA.
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Xu J, Li C, Yin XH, Zhang GY. Additive neuroprotection of GABA A and GABA B receptor agonists in cerebral ischemic injury via PI-3K/Akt pathway inhibiting the ASK1-JNK cascade. Neuropharmacology 2008; 54:1029-40. [PMID: 18410948 DOI: 10.1016/j.neuropharm.2008.01.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 11/20/2007] [Accepted: 01/28/2008] [Indexed: 02/04/2023]
Abstract
Co-activation of GABA A and GABA B receptors results in neuroprotection during in vitro ischemia. However, it is unclear whether this mode of action is responsible for its neuroprotective effects in animal models of ischemia in vivo, and the precise mechanisms are also unknown. This study compared the neuroprotective efficacies of muscimol, a GABA A receptor agonist, and a GABA B receptor agonist baclofen in rat brain ischemia. The additive neuroprotection could be obtained in the hippocampal CA1 pyramidal cells prominently when muscimol and baclofen were co-applied. In particular, our study showed that co-activation of GABA A and GABA B receptors could strongly increase Akt activation and inhibit ASK1 activation by phosphorylation of serine 83 of ASK1. PI-3K inhibitor LY294002 reversed the increasing Akt activation and ASK1 (S83) phosphorylation. Moreover, MKK4/MKK7-JNK signaling activation was inhibited during ischemia/reperfusion (I/R) by co-treatment of muscimol with baclofen. JNK substrate, Bcl-2 and c-jun phosphorylation were also attenuated. Our results indicated that co-activation of GABA A receptor and GABA B receptor exerted neuroprotective effect via PI-3K/Akt pathway, which could inhibit the ASK1-c-Jun N-terminal protein kinase (JNK) cascade.
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Affiliation(s)
- Jing Xu
- Research Center for Biochemistry and Molecular Biology, The Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical College, Jiangsu 221002, PR China
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19
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Yano N, Ianus V, Zhao TC, Tseng A, Padbury JF, Tseng YT. A novel signaling pathway for β-adrenergic receptor-mediated activation of phosphoinositide 3-kinase in H9c2 cardiomyocytes. Am J Physiol Heart Circ Physiol 2007; 293:H385-93. [PMID: 17369456 DOI: 10.1152/ajpheart.01318.2006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Stimulation of cardiac β-adrenergic receptors (β-AR) activates both the Gs- and Gi-coupled signaling cascades, including the phosphoinositide 3 kinase (PI3K) pathway, that have important physiological implications. Multiple isoforms of PI3K exist in the heart. The goals of this study were to examine the intracellular signaling pathways linking β-AR to PI3K and to identify the PI3K isoform mediating this transactivation in a cardiac context. Acute β-AR stimulation with isoproterenol resulted in increased tyrosine kinase-associated PI3K activity and phosphorylation of Akt and p70S6K in H9c2 cardiomyocytes. Cotreatment with ICI-118,551, but not CGP-20712, abolished the increase in PI3K activity, suggesting a β2-AR-mediated event. PI3K activation was also abrogated by cotreatment with pertussis toxin, 4-amino-5-(4-chlorophenyl)-7-( t-butyl)pyrazolol[3,4-d]pyrimidine (PP2, a selective Src-family tyrosine kinases inhibitor), or AG-1296 [selective platelet-derived growth factor receptor (PDGFR) inhibitor] but not with an inhibitor for protein kinase A, protein kinase C, Ras, adenylyl cyclase, epidermal growth factor receptor, or insulin-like growth factor-1 receptor. β-AR stimulation induced an increase in tyrosine phosphorylation of PDGFR, which was abolished by inhibition of Src either by PP2 or small interfering RNA. Moreover, H9c2 cardiomyocytes stably transfected with a vector expressing a Gβγ sequestrant peptide derived from the COOH-terminus of β-AR kinase-1 failed to activate PI3K after β-AR stimulation, suggesting Gβγ is required for the transactivation. Furthermore, acute β-AR stimulation in vivo resulted in increases in PDGFR-associated PI3K and PI3Kα isoform activities but not the activities of other isoforms (PI3Kβ, -δ, -γ) in adult mouse heart. Taken together, these data provide in vitro and in vivo evidence for a novel mechanism of β-AR-mediated transactivation of cardiac PI3Kα via sequential involvement of Gαi/Gβγ, Src, and PDGFR.
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Affiliation(s)
- Naohiro Yano
- Department of Pediatrics, Women and Infants Hospital of Rhode Island, Brown Medical School, 101 Dudley Street, Providence, RI 02905, USA
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Zhang QG, Han D, Xu J, Lv Q, Wang R, Yin XH, Xu TL, Zhang GY. Ischemic preconditioning negatively regulates plenty of SH3s-mixed lineage kinase 3-Rac1 complex and c-Jun N-terminal kinase 3 signaling via activation of Akt. Neuroscience 2006; 143:431-44. [PMID: 16973299 DOI: 10.1016/j.neuroscience.2006.07.049] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2006] [Revised: 07/24/2006] [Accepted: 07/26/2006] [Indexed: 01/22/2023]
Abstract
Activation of Akt/protein kinase B has been recently reported to play an important role in ischemic tolerance. We here demonstrate that the decreased protein expression and phosphorylation of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) underlie the increased Akt-Ser-473 phosphorylation in the hippocampal CA1 subfield in ischemic preconditioning (IPC). Co-immunoprecipitation analysis reveals that Akt physically interacts with Rac1, a small Rho family GTPase required for mixed lineage kinase 3 (MLK3) autophosphorylation, and both this interaction and Rac1-Ser-71 phosphorylation induced by Akt are promoted in preconditioned rats. In addition, we show that Akt activation results in the disassembly of the plenty of SH3s (POSH)-MLK3-Rac1 signaling complex and down-regulation of the activation of MLK3/c-Jun N-terminal kinase (JNK) pathway. Akt activation results in decreased serine phosphorylation of 14-3-3, a cytoplasmic anchor of Bax, and prevents ischemia-induced mitochondrial translocation of Bax, release of cytochrome c, and activation of caspase-3. The expression of Fas ligand is also decreased in the CA1 region. Akt activation protects against apoptotic neuronal death as shown in TUNEL staining following IPC. Intracerebral infusion of LY294002 before IPC reverses the increase in Akt phosphorylation and the decrease in JNK signaling activation, as well as the neuroprotective action of IPC. Our results suggest that activation of pro-apoptotic MLK3/JNK3 cascade can be suppressed through activating anti-apoptotic phosphoinositide 3-kinase/Akt pathway induced by a sublethal ischemic insult, which provides a functional link between Akt and the JNK family of stress-activated kinases in ischemic tolerance.
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Affiliation(s)
- Q-G Zhang
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, Jiangsu 221002, China
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Abstract
Phosphatidylinositol 3-kinases (PI3Ks) evolved from a single enzyme that regulates vesicle trafficking in unicellular eukaryotes into a family of enzymes that regulate cellular metabolism and growth in multicellular organisms. In this review, we examine how the PI3K pathway has evolved to control these fundamental processes, and how this pathway is in turn regulated by intricate feedback and crosstalk mechanisms. In light of the recent advances in our understanding of the function of PI3Ks in the pathogenesis of diabetes and cancer, we discuss the exciting therapeutic opportunities for targeting this pathway to treat these diseases.
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Affiliation(s)
- Jeffrey A Engelman
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Zhang QG, Wang XT, Han D, Yin XH, Zhang GY, Xu TL. Akt inhibits MLK3/JNK3 signaling by inactivating Rac1: a protective mechanism against ischemic brain injury. J Neurochem 2006; 98:1886-98. [PMID: 16831194 DOI: 10.1111/j.1471-4159.2006.04020.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The overall goal of this study was to determine the molecular basis by which mixed-lineage kinase 3 (MLK3) kinase and its signaling pathways are negatively regulated by the pro-survival Akt pathway in cerebral ischemia. We demonstrated that tyrosine phosphorylation of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) underlies the increased Akt-Ser473 phosphorylation by orthovanadate. Co-immunoprecipitation analysis revealed that endogenous Akt physically interacts with Rac1 in the hippocampal CA1 region, and this interaction is promoted on tyrosine phosphatase inhibition. The elevated Akt activation can deactivate MLK3 by phosphorylation at the Ser71 residue of Rac1, a small Rho family of guanidine triphosphatases required for MLK3 autophosphorylation. Subsequently, inhibition of c-Jun N-terminal kinase 3 (JNK3) results in decreased serine phosphorylation of 14-3-3, a cytoplasmic anchor of Bax, and prevents ischemia-induced mitochondrial translocation of Bax, release of cytochrome c and activation of caspase 3. At the same time, the expression of Fas-ligand decreases in the CA1 region after inhibition of c-Jun activation. The neuroprotective effect of Akt activation is significant in the CA1 region after global cerebral ischemia. Our results suggest that the activation of the pro-apoptotic MLK3/JNK3 cascade induced by ischemic stress can be suppressed through activation of the anti-apoptotic phosphatidylinositol 3-kinase/Akt pathway, which provides a direct link between Akt and the family of stress-activated kinases.
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Affiliation(s)
- Quan-Guang Zhang
- Department of Neurobiology and Biophysics, University of Science and Technology of China, Hefei, Anhui, China
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Cauwels A, Janssen B, Buys E, Sips P, Brouckaert P. Anaphylactic shock depends on PI3K and eNOS-derived NO. J Clin Invest 2006; 116:2244-51. [PMID: 16886062 PMCID: PMC1523420 DOI: 10.1172/jci25426] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2005] [Accepted: 05/02/2006] [Indexed: 11/17/2022] Open
Abstract
Anaphylactic shock is a sudden, life-threatening allergic reaction associated with severe hypotension. Platelet-activating factor (PAF) is implicated in the cardiovascular dysfunctions occurring in various shock syndromes, including anaphylaxis. Excessive production of the vasodilator NO causes inflammatory hypotension and shock, and it is generally accepted that transcriptionally regulated inducible iNOS is responsible for this. Nevertheless, the contribution of NO to PAF-induced shock or anaphylactic shock is still ambiguous. We studied PAF and anaphylactic shock in conscious mice. Surprisingly, hyperacute PAF shock depended entirely on NO, produced not by inducible iNOS, but by constitutive eNOS, rapidly activated via the PI3K pathway. Soluble guanylate cyclase (sGC) is generally regarded as the principal vasorelaxing mediator of NO. Nevertheless, although methylene blue partially prevented PAF shock, neither 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ) nor sGCalpha1 deficiency did. Also, in 2 different models of active systemic anaphylaxis, inhibition of NOS, PI3K, or Akt or eNOS deficiency provided complete protection. In contrast to the unsubstantiated paradigm that only excessive iNOS-derived NO underlies cardiovascular collapse in shock, our data strongly support the unexpected concept that eNOS-derived NO is the principal vasodilator in anaphylactic shock and define eNOS and/or PI3K or Akt as new potential targets for treating anaphylaxis.
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Affiliation(s)
- Anje Cauwels
- Molecular Pathophysiology and Experimental Therapy Unit, Department for Molecular Biomedical Research, Ghent University, Belgium, and Cardiovascular Research Center, Massachusetts General Hospital, Charlestown, USA.
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Samuelsson AM, Bollano E, Mobini R, Larsson BM, Omerovic E, Fu M, Waagstein F, Holmäng A. Hyperinsulinemia: effect on cardiac mass/function, angiotensin II receptor expression, and insulin signaling pathways. Am J Physiol Heart Circ Physiol 2006; 291:H787-96. [PMID: 16565309 DOI: 10.1152/ajpheart.00974.2005] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
To investigate the association between hyperinsulinemia and cardiac hypertrophy, we treated rats with insulin for 7 wk and assessed effects on myocardial growth, vascularization, and fibrosis in relation to the expression of angiotensin II receptors (AT-R). We also characterized insulin signaling pathways believed to promote myocyte growth and interact with proliferative responses mediated by G protein-coupled receptors, and we assessed myocardial insulin receptor substrate-1 (IRS-1) and p110 alpha catalytic and p85 regulatory subunits of phospatidylinositol 3 kinase (PI3K), Akt, MEK, ERK1/2, and S6 kinase-1 (S6K1). Left ventricular (LV) geometry and performance were evaluated echocardiographically. Insulin decreased AT1a-R mRNA expression but increased protein levels and increased AT2-R mRNA and protein levels and phosphorylation of IRS-1 (Ser374/Tyr989), MEK1/2 (Ser218/Ser222), ERK1/2 (Thr202/Tyr204), S6K1 (Thr421/Ser424/Thr389), Akt (Thr308/Thr308), and PI3K p110 alpha but not of p85 (Tyr508). Insulin increased LV mass and relative wall thickness and reduced stroke volume and cardiac output. Histochemical examination demonstrated myocyte hypertrophy and increases in interstitial fibrosis. Metoprolol plus insulin prevented the increase in relative wall thickness, decreased fibrosis, increased LV mass, and improved function seen with insulin alone. Thus our data demonstrate that chronic hyperinsulinemia decreases AT1a-to-AT2 ratio and increases MEK-ERK1/2 and S6K1 pathway activity related to hypertrophy. These changes might be crucial for increased cardiovascular growth and fibrosis and signs of impaired LV function.
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Affiliation(s)
- Anne-Maj Samuelsson
- Cardiovascular Institute, The Wallenberg Laboratory, Sahlgrenska Univ. Hospital, Göteborg University, S-413 45 Göteborg, Sweden.
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Luo J, McMullen JR, Sobkiw CL, Zhang L, Dorfman AL, Sherwood MC, Logsdon MN, Horner JW, DePinho RA, Izumo S, Cantley LC. Class IA phosphoinositide 3-kinase regulates heart size and physiological cardiac hypertrophy. Mol Cell Biol 2005; 25:9491-502. [PMID: 16227599 PMCID: PMC1265829 DOI: 10.1128/mcb.25.21.9491-9502.2005] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Class I(A) phosphoinositide 3-kinases (PI3Ks) are activated by growth factor receptors, and they regulate, among other processes, cell growth and organ size. Studies using transgenic mice overexpressing constitutively active and dominant negative forms of the p110alpha catalytic subunit of class I(A) PI3K have implicated the role of this enzyme in regulating heart size and physiological cardiac hypertrophy. To further understand the role of class I(A) PI3K in controlling heart growth and to circumvent potential complications from the overexpression of dominant negative and constitutively active proteins, we generated mice with muscle-specific deletion of the p85alpha regulatory subunit and germ line deletion of the p85beta regulatory subunit of class I(A) PI3K. Here we show that mice with cardiac deletion of both p85 subunits exhibit attenuated Akt signaling in the heart, reduced heart size, and altered cardiac gene expression. Furthermore, exercise-induced cardiac hypertrophy is also attenuated in the p85 knockout hearts. Despite such defects in postnatal developmental growth and physiological hypertrophy, the p85 knockout hearts exhibit normal contractility and myocardial histology. Our results therefore provide strong genetic evidence that class I(A) PI3Ks are critical regulators for the developmental growth and physiological hypertrophy of the heart.
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Affiliation(s)
- Ji Luo
- Division of Systems Biology, Harvard Medical School, Beth Israel Deaconess Medical Center, 77 Avenue Louis Pasteur, 10th Floor, Boston, MA 02115, USA
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