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Clathrin-nanoparticles deliver BDNF to hippocampus and enhance neurogenesis, synaptogenesis and cognition in HIV/neuroAIDS mouse model. Commun Biol 2022; 5:236. [PMID: 35301411 PMCID: PMC8931075 DOI: 10.1038/s42003-022-03177-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 02/17/2022] [Indexed: 01/02/2023] Open
Abstract
Brain derived neurotrophic factor (BDNF) promotes the growth, differentiation, maintenance and survival of neurons. These attributes make BDNF a potentially powerful therapeutic agent. However, its charge, instability in blood, and poor blood brain barrier (BBB) penetrability have impeded its development. Here, we show that engineered clathrin triskelia (CT) conjugated to BDNF (BDNF-CT) and delivered intranasally increased hippocampal BDNF concentrations 400-fold above that achieved previously with intranasal BDNF alone. We also show that BDNF-CT targeted Tropomyosin receptor kinase B (TrkB) and increased TrkB expression and downstream signaling in iTat mouse brains. Mice were induced to conditionally express neurotoxic HIV Transactivator-of-Transcription (Tat) protein that decreases BDNF. Down-regulation of BDNF is correlated with increased severity of HIV/neuroAIDS. BDNF-CT enhanced neurorestorative effects in the hippocampus including newborn cell proliferation and survival, granule cell neurogenesis, synaptogenesis and increased dendritic integrity. BDNF-CT exerted cognitive-enhancing effects by reducing Tat-induced learning and memory deficits. These results show that CT bionanoparticles efficiently deliver BDNF to the brain, making them potentially powerful tools in regenerative medicine.
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Lee HW, Ahmad M, Weldrick JJ, Wang HW, Burgon PG, Leenen FHH. Effects of exercise training and TrkB blockade on cardiac function and BDNF-TrkB signaling postmyocardial infarction in rats. Am J Physiol Heart Circ Physiol 2018; 315:H1821-H1834. [PMID: 30311496 DOI: 10.1152/ajpheart.00245.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Exercise training is beneficial for preserving cardiac function postmyocardial infarction (post-MI), but the underlying mechanisms are not well understood. We investigated one possible mechanism, brain-derived neurotrophic factor (BDNF)-tropomyosin-related kinase B (TrkB) signaling, with the TrkB blocker ANA-12 (0.5 mg·kg-1·day-1). Male Wistar rats underwent sham surgery or ligation of the left descending coronary artery. The surviving MI rats were allocated as follows: sedentary MI rats treated with vehicle, exercise-trained MI rats treated with vehicle, and exercise-trained MI rats treated with ANA-12. Exercise training was done 5 days/wk for 4 wk on a motor-driven treadmill. At the end, left ventricular (LV) function was evaluated by echocardiography and a Millar catheter. Mature BDNF and downstream effectors of BDNF-TrkB signaling, Ca2+/calmodulin-dependent protein kinase II (CaMKII), Akt, and AMP-activated protein kinase (AMPK), were assessed in the noninfarct area of the LV by Western blot analysis. Exercise training increased stroke volume and cardiac index and attenuated the decrease in ejection fraction (EF) and increase in LV end-diastolic pressure post-MI. ANA-12 blocked the improvement of EF and attenuated the increases in stroke volume and cardiac index but did not affect LV end-diastolic pressure. Exercise training post-MI prevented decreases in mature BDNF, phosphorylated (p-)CaMKII, p-Akt, and p-AMPKα expression. These effects were all blocked by ANA-12 except for p-AMPKα. In conclusion, the exercise-induced improvement of EF is mediated by the BDNF-TrkB axis and the downstream effectors CaMKII and Akt. BDNF-TrkB signaling appears to contribute to the improvement in systolic function by exercise training. NEW & NOTEWORTHY Exercise training improves ejection fraction and left ventricular end-diastolic pressure (LVEDP) and increases stroke volume and cardiac index in rats postmyocardial infarction (post-MI). The improvement of EF but not LVEDP is mediated by activation of the brain-derived neurotrophic factor (BDNF)-tropomyosin-related kinase B (TrkB) axis and downstream effectors Ca2+/calmodulin-dependent protein kinase II (CaMKII) and Akt. This suggests that activation of BDNF-TrkB signaling and CaMKII and Akt is a promising target to attenuate progressive cardiac dysfunction post-MI.
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Affiliation(s)
- Heow Won Lee
- Brain and Heart Research Group, University of Ottawa Heart Institute , Ottawa, ON , Canada
| | - Monir Ahmad
- Brain and Heart Research Group, University of Ottawa Heart Institute , Ottawa, ON , Canada
| | - Jonathan J Weldrick
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa , Ottawa, ON , Canada
| | - Hong-Wei Wang
- Brain and Heart Research Group, University of Ottawa Heart Institute , Ottawa, ON , Canada
| | - Patrick G Burgon
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa , Ottawa, ON , Canada
| | - Frans H H Leenen
- Brain and Heart Research Group, University of Ottawa Heart Institute , Ottawa, ON , Canada
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ASIC1a mediates the drug resistance of human hepatocellular carcinoma via the Ca 2+/PI3-kinase/AKT signaling pathway. J Transl Med 2017; 97:53-69. [PMID: 27918554 PMCID: PMC5220138 DOI: 10.1038/labinvest.2016.127] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/20/2016] [Accepted: 10/28/2016] [Indexed: 01/12/2023] Open
Abstract
Chemotherapy is the main treatment method of patients with advanced liver cancer. However, drug resistance is a serious problem in the treatment of hepatocellular carcinoma (HCC). Acid sensing ion channel 1a (ASIC1a) is a H+-gated cation channel; it mediates tumor cell migration and invasion, which suggests that it is involved in the development of malignant tumors. Therefore, we studied the relationship between ASIC1a and drug resistance in human hepatocellular carcinoma. In our study, we found that ASIC1a is highly expressed in human HCC tissue, and that its levels were significantly increased in resistant HCC cells Bel7402/FU and HepG2/ADM. Inhibiting the activity of ASIC1a enhances the chemosensitivity of Bel7402/FU and HepG2/ADM cells. The overexpression of ASIC1a contributed to drug resistance in Bel7402 and HepG2 cells, whereas knockdown of ASIC1a overcame drug resistance in Bel7402/FU and HepG2/ADM cells. We further demonstrated that ASIC1a mediated calcium influx, which resulted in the activation of PI3K/AKT signaling and increased drug resistance. These data suggest that ASIC1a/Ca2+/PI3K/AKT signaling represents a novel pathway that regulates drug resistance, thus offering a potential target for chemotherapy of HCC.
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Gutierrez-Merino C, Marques-da-Silva D, Fortalezas S, K. Samhan-Arias A. The critical role of lipid rafts nanodomains in the cross-talk between calcium and reactive oxygen and nitrogen species in cerebellar granule neurons apoptosis by extracellular potassium deprivation. AIMS MOLECULAR SCIENCE 2016. [DOI: 10.3934/molsci.2016.1.12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Satheesh NJ, Büsselberg D. The role of intracellular calcium for the development and treatment of neuroblastoma. Cancers (Basel) 2015; 7:823-48. [PMID: 26010602 PMCID: PMC4491686 DOI: 10.3390/cancers7020811] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Accepted: 05/05/2015] [Indexed: 12/16/2022] Open
Abstract
Neuroblastoma is the second most common paediatric cancer. It developsfrom undifferentiated simpatico-adrenal lineage cells and is mostly sporadic; however, theaetiology behind the development of neuroblastoma is still not fully understood. Intracellularcalcium ([Ca2+]i) is a secondary messenger which regulates numerous cellular processesand, therefore, its concentration is tightly regulated. This review focuses on the role of[Ca2+]i in differentiation, apoptosis and proliferation in neuroblastoma. It describes themechanisms by which [Ca2+]i is regulated and how it modulates intracellular pathways.Furthermore, the importance of [Ca2+]i for the function of anti-cancer drugs is illuminatedin this review as [Ca2+]i could be a target to improve the outcome of anti-cancer treatmentin neuroblastoma. Overall, modulations of [Ca2+]i could be a key target to induce apoptosisin cancer cells leading to a more efficient and effective treatment of neuroblastoma.
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Affiliation(s)
- Noothan Jyothi Satheesh
- Weill Cornell Medical College in Qatar, Qatar Foundation-Education City, POB 24144, Doha, Qatar.
| | - Dietrich Büsselberg
- Weill Cornell Medical College in Qatar, Qatar Foundation-Education City, POB 24144, Doha, Qatar.
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Secondo A, Esposito A, Sirabella R, Boscia F, Pannaccione A, Molinaro P, Cantile M, Ciccone R, Sisalli MJ, Scorziello A, Di Renzo G, Annunziato L. Involvement of the Na+/Ca2+ exchanger isoform 1 (NCX1) in neuronal growth factor (NGF)-induced neuronal differentiation through Ca2+-dependent Akt phosphorylation. J Biol Chem 2014; 290:1319-31. [PMID: 25416782 DOI: 10.1074/jbc.m114.555516] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
NGF induces neuronal differentiation by modulating [Ca(2+)]i. However, the role of the three isoforms of the main Ca(2+)-extruding system, the Na(+)/Ca(2+) exchanger (NCX), in NGF-induced differentiation remains unexplored. We investigated whether NCX1, NCX2, and NCX3 isoforms could play a relevant role in neuronal differentiation through the modulation of [Ca(2+)]i and the Akt pathway. NGF caused progressive neurite elongation; a significant increase of the well known marker of growth cones, GAP-43; and an enhancement of endoplasmic reticulum (ER) Ca(2+) content and of Akt phosphorylation through an early activation of ERK1/2. Interestingly, during NGF-induced differentiation, the NCX1 protein level increased, NCX3 decreased, and NCX2 remained unaffected. At the same time, NCX total activity increased. Moreover, NCX1 colocalized and coimmunoprecipitated with GAP-43, and NCX1 silencing prevented NGF-induced effects on GAP-43 expression, Akt phosphorylation, and neurite outgrowth. On the other hand, the overexpression of its neuronal splicing isoform, NCX1.4, even in the absence of NGF, induced an increase in Akt phosphorylation and GAP-43 protein expression. Interestingly, tetrodotoxin-sensitive Na(+) currents and 1,3-benzenedicarboxylic acid, 4,4'-[1,4,10-trioxa-7,13-diazacyclopentadecane-7,13-diylbis(5-methoxy-6,12-benzofurandiyl)]bis-, tetrakis[(acetyloxy)methyl] ester-detected [Na(+)]i significantly increased in cells overexpressing NCX1.4 as well as ER Ca(2+) content. This latter effect was prevented by tetrodotoxin. Furthermore, either the [Ca(2+)]i chelator(1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid) (BAPTA-AM) or the PI3K inhibitor LY 294002 prevented Akt phosphorylation and GAP-43 protein expression rise in NCX1.4 overexpressing cells. Moreover, in primary cortical neurons, NCX1 silencing prevented Akt phosphorylation, GAP-43 and MAP2 overexpression, and neurite elongation. Collectively, these data show that NCX1 participates in neuronal differentiation through the modulation of ER Ca(2+) content and PI3K signaling.
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Affiliation(s)
- Agnese Secondo
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Alba Esposito
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Rossana Sirabella
- the Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) SDN, Naples 80143, Italy
| | - Francesca Boscia
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Anna Pannaccione
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Pasquale Molinaro
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Maria Cantile
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Roselia Ciccone
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Maria Josè Sisalli
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Antonella Scorziello
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Gianfranco Di Renzo
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and
| | - Lucio Annunziato
- From the Department of Neuroscience and Reproductive and Odontostomatological Sciences, School of Medicine, "Federico II" University of Naples, Via Sergio Pansini 5, Naples 80131, Italy and the Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) SDN, Naples 80143, Italy
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Li Y, Yan X, Liu J, Li L, Hu X, Sun H, Tian J. Pulsed electromagnetic field enhances brain-derived neurotrophic factor expression through L-type voltage-gated calcium channel- and Erk-dependent signaling pathways in neonatal rat dorsal root ganglion neurons. Neurochem Int 2014; 75:96-104. [PMID: 24937769 DOI: 10.1016/j.neuint.2014.06.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 05/18/2014] [Accepted: 06/07/2014] [Indexed: 11/30/2022]
Abstract
Although pulsed electromagnetic field (PEMF) exposure has been reported to promote neuronal differentiation, the mechanism is still unclear. Here, we aimed to examine the effects of PEMF exposure on brain-derived neurotrophic factor (Bdnf) mRNA expression and the correlation between the intracellular free calcium concentration ([Ca(2+)]i) and Bdnf mRNA expression in cultured dorsal root ganglion neurons (DRGNs). Exposure to 50Hz and 1mT PEMF for 2h increased the level of [Ca(2+)]i and Bdnf mRNA expression, which was found to be mediated by increased [Ca(2+)]i from Ca(2+) influx through L-type voltage-gated calcium channels (VGCCs). However, calcium mobilization was not involved in the increased [Ca(2+)]i and BDNF expression, indicating that calcium influx was one of the key factors responding to PEMF exposure. Moreover, PD098059, an extracellular signal-regulated kinase (Erk) inhibitor, strongly inhibited PEMF-dependant Erk1/2 activation and BDNF expression, indicating that Erk activation is required for PEMF-induced upregulation of BDNF expression. These findings indicated that PEMF exposure increased BDNF expression in DRGNs by activating Ca(2+)- and Erk-dependent signaling pathways.
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Affiliation(s)
- Yuan Li
- Second Clinical Medical College, Southern Medical University, Guangzhou 510280, PR China
| | - Xiaodong Yan
- Department of Orthopaedics, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, PR China
| | - Juanfang Liu
- Department of Clinical Aerospace Medicine, Fourth Military Medical University, Xi'an 710032, PR China
| | - Ling Li
- Department of Geriatrics, Shaanxi Provincial TCM Hospital, Xi'an 710032, PR China
| | - Xinghua Hu
- Department of Endocrinology, Shaanxi Provincial TCM Hospital, Xi'an 710032, PR China
| | - Honghui Sun
- Department of Orthopaedics, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, PR China.
| | - Jing Tian
- Second Clinical Medical College, Southern Medical University, Guangzhou 510280, PR China.
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Xie W, Song YJ, Li D, Pan LP, Wu QJ, Tian X. The suppression of epileptiform discharges in cultured hippocampal neurons is regulated via alterations in full-length tropomyosin-related kinase type B receptors signalling activity. Eur J Neurosci 2014; 40:2564-75. [PMID: 24830751 DOI: 10.1111/ejn.12620] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Revised: 04/01/2014] [Accepted: 04/11/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Wei Xie
- School of Biomedical Engineering; Tianjin Medical University; Tianjin China
| | - Yi-Jun Song
- Department of Neurology; Tianjin Medical University General Hospital & Key Laboratory of Neurotrauma; Variation and Regeneration; Ministry of Education and Tianjin Municipal Government; Tianjin China
| | - Dai Li
- Senior Officials Inpatient Ward; Tianjin Medical University General Hospital and Tianjin Neurological Institute; Tianjin China
| | - Li-Ping Pan
- Department of Neurology; Tianjin Medical University General Hospital & Key Laboratory of Neurotrauma; Variation and Regeneration; Ministry of Education and Tianjin Municipal Government; Tianjin China
| | - Qiu-Jing Wu
- Department of Neurology; Tianjin Medical University General Hospital & Key Laboratory of Neurotrauma; Variation and Regeneration; Ministry of Education and Tianjin Municipal Government; Tianjin China
| | - Xin Tian
- School of Biomedical Engineering; Tianjin Medical University; Tianjin China
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Protein phosphatase 2A dephosphorylates SNAP-25 through two distinct mechanisms in mouse brain synaptosomes. Neurosci Res 2013; 75:184-9. [DOI: 10.1016/j.neures.2013.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 01/07/2013] [Accepted: 01/07/2013] [Indexed: 01/03/2023]
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Rusciano M, Maione A, Illario M. Sisters Acts: Converging Signaling Between CaMKII and CaMKIV, Two Members of the Same Family. Transl Med UniSa 2012; 4:66-72. [PMID: 23905065 PMCID: PMC3728794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Calcium (Ca(2+)) is a universal second messenger that regulates a number of diverse cellular processes including cell proliferation, development, motility, secretion, learning and memory1, 2. A variety of stimuli, such as hormones, growth factors, cytokines, and neurotransmitters induce changes in the intracellular levels of Ca(2+). The most ubiquitous and abundant protein that serves as a receptor to sense changes in Ca(2+) concentrations is Calmodulin (CaM), thus mediating the role as second messenger of this ion. The Ca(2+)/CaM complex initiates a plethora of signaling cascades that culminate in alteration of cell functions. Among the many Ca(2+)/CaM binding proteins, the multifunctional protein kinases CaMKII and CaMKIV play pivotal roles in the cell.
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Hidano S, Kitamura D, Kumar L, Geha RS, Goitsuka R. SLP-76 is required for high-affinity IgE receptor- and IL-3 receptor-mediated activation of basophils. Int Immunol 2012; 24:719-27. [PMID: 22875843 DOI: 10.1093/intimm/dxs072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Basophils have been reported to play a critical role in allergic inflammation by secreting IL-4 in response to IL-3 or high-affinity IgE receptor (FcεRI)-cross-linking. However, the signaling pathways downstream of FcεRI and the IL-3 receptor in basophils have yet to be determined. In the present study, we used mice deficient in SLP-76 (Src homology 2 domain-containing leukocyte phosphoprotein of 76kDa) to demonstrate critical functions of this adaptor molecule in transducing FcεRI- and IL-3 receptor-mediated signals that induce basophil activation. Although SLP-76 was dispensable for in vivo differentiation, as well as IL-3-induced in vitro proliferation of basophils, IL-4 production induced by both stimuli was completely ablated by SLP-76 deficiency. Biochemical analyses revealed that IL-3-induced phosphorylation of phospholipase C (PLC) γ2 and Akt, but not STAT5, was severely reduced in SLP-76-deficient basophils, whereas FcεRI cross-linking phosphorylation of PLCγ2, but not Akt, was abrogated by SLP-76 deficiency, suggesting important differences in the requirement of SLP-76 for Akt activation between FcεRI- and IL-3 receptor-mediated signaling pathways in basophils. Because IL-3-induced IL-4 production was sensitive to calcineurin inhibitors and an intracellular calcium chelator, in addition to PI3K inhibitors, SLP-76 appears to regulate FcεRI- and IL-3 receptor-induced IL-4 production via mediating PLCγ2 activation in basophils. Taken together, these findings indicate that SLP-76 is an essential signaling component for basophil activation downstream of both FcεRI and the IL-3 receptor.
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Affiliation(s)
- Shinya Hidano
- Division of Development and Aging, Research Institute for Biological Sciences, 2669 Yamazaki, Noda, Chiba 278-0022, Japan
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Dorsey SG, Lovering RM, Renn CL, Leitch CC, Liu X, Tallon LJ, Sadzewicz LD, Pratap A, Ott S, Sengamalay N, Jones KM, Barrick C, Fulgenzi G, Becker J, Voelker K, Talmadge R, Harvey BK, Wyatt RM, Vernon-Pitts E, Zhang C, Shokat K, Fraser-Liggett C, Balice-Gordon RJ, Tessarollo L, Ward CW. Genetic deletion of trkB.T1 increases neuromuscular function. Am J Physiol Cell Physiol 2011; 302:C141-53. [PMID: 21865582 DOI: 10.1152/ajpcell.00469.2010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Neurotrophin-dependent activation of the tyrosine kinase receptor trkB.FL modulates neuromuscular synapse maintenance and function; however, it is unclear what role the alternative splice variant, truncated trkB (trkB.T1), may have in the peripheral neuromuscular axis. We examined this question in trkB.T1 null mice and demonstrate that in vivo neuromuscular performance and nerve-evoked muscle tension are significantly increased. In vitro assays indicated that the gain-in-function in trkB.T1(-/-) animals resulted specifically from an increased muscle contractility, and increased electrically evoked calcium release. In the trkB.T1 null muscle, we identified an increase in Akt activation in resting muscle as well as a significant increase in trkB.FL and Akt activation in response to contractile activity. On the basis of these findings, we conclude that the trkB signaling pathway might represent a novel target for intervention across diseases characterized by deficits in neuromuscular function.
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Affiliation(s)
- Susan G Dorsey
- University of Maryland Baltimore School of Nursing, Baltimore, Maryland 21201, USA.
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Wenjin W, Wenchao L, Hao Z, Feng L, Yan W, Wodong S, Xianqun F, Wenlong D. Electrical Stimulation Promotes BDNF Expression in Spinal Cord Neurons Through Ca2+- and Erk-Dependent Signaling Pathways. Cell Mol Neurobiol 2011; 31:459-67. [DOI: 10.1007/s10571-010-9639-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Accepted: 12/09/2010] [Indexed: 01/23/2023]
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Mannoury la Cour C, Salles MJ, Pasteau V, Millan MJ. Signaling Pathways Leading to Phosphorylation of Akt and GSK-3β by Activation of Cloned Human and Rat Cerebral D2 and D3 Receptors. Mol Pharmacol 2010; 79:91-105. [DOI: 10.1124/mol.110.065409] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Zhou X, Lin DS, Zheng F, Sutton MA, Wang H. Intracellular calcium and calmodulin link brain-derived neurotrophic factor to p70S6 kinase phosphorylation and dendritic protein synthesis. J Neurosci Res 2010; 88:1420-32. [PMID: 20029971 DOI: 10.1002/jnr.22321] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The mammalian target of rapamycin (mTOR)/p70S6 kinase (S6K) pathway plays an important role in brain-derived neurotrophic factor (BDNF)-mediated protein synthesis and neuroplasticity. Although many aspects of neuronal function are regulated by intracellular calcium ([Ca(2+)](i)) and calmodulin (CaM), their functions in BDNF-induced phosphorylation of p70S6K and protein synthesis are largely unknown. Here, we report that BDNF, via TrkB-dependent activation of mTOR, induces sustained phosphorylation of p70S6K at Thr389 and Thr421/Ser424. BDNF-induced phosphorylation at Thr389 was dependent on PI3 kinase but independent of ERK-MAPK. The previously identified MAPK phosphorylation site at Thr421/Ser424 required both PI3K and MAPK in BDNF-stimulated neurons. Furthermore, we found that the reduction in [Ca(2+)](i), but not extracellular calcium, blocked the BDNF-induced phosphorylation of p70S6K at both sites. Inhibition of CaM by W13 also blocked p70S6K phosphorylation. In correlation, W13 inhibited BDNF-induced local dendritic protein synthesis. Interestingly, sustained elevation of [Ca(2+)](i) by membrane depolarization antagonized the BDNF-induced p70S6K phosphorylation. Finally, the BDNF-induced p70S6K phosphorylation did not require the increase of calcium level through either extracellular influx or PLC-mediated intracellular calcium release. Collectively, these results indicate that the basal level of intracellular calcium gates BDNF-induced activation of p70S6K and protein synthesis through CaM. (c) 2009 Wiley-Liss, Inc.
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Affiliation(s)
- Xianju Zhou
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
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Zhou X, Moon C, Zheng F, Luo Y, Soellner D, Nuñez JL, Wang H. N-methyl-D-aspartate-stimulated ERK1/2 signaling and the transcriptional up-regulation of plasticity-related genes are developmentally regulated following in vitro neuronal maturation. J Neurosci Res 2010; 87:2632-44. [PMID: 19396876 DOI: 10.1002/jnr.22103] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The general features of neuroplasticity are developmentally regulated. Although it has been hypothesized that the loss of plasticity in mature neurons may be due to synaptic saturation and functional reduction of N-methyl-D-aspartate receptors (NMDAR), the molecular mechanisms remain largely unknown. We examined the effects of NMDAR activation and KCl-mediated membrane depolarization on ERK1/2 signaling following in vitro maturation of cultured cortical neurons. Although NMDA stimulated a robust increase in intracellular calcium at both DIV (day in vitro) 3 and 14, the activation of ERK1/2 and cAMP responsive element-binding protein (CREB) was impaired at DIV 14. Specifically, the phosphorylation of ERK1/2 was stimulated by both NMDA and KCl at DIV 3. However, at DIV 14, NMDA- but not KCl-stimulated ERK1/2 and CREB phosphorylation was significantly diminished. Consistently, the NMDA-induced transcription of ERK/CREB-regulated genes Bdnf exon 4, Arc, and zif268 was significantly attenuated at DIV 14. Moreover, in comparison with 3 DIV neurons, the phosphorylated-ERK1/2 in 14 DIV neurons displayed a tremendous increase following maturation and was more susceptible to dephosphorylation. Blocking calcium channels by nifedipine or NMDAR by APV caused a more dramatic ERK dephosphorylation in 14 DIV neurons. We further demonstrate that the loss of plasticity-related signaling is unrelated to NMDA-induced cell death of the 14 DIV neurons. Taken together, these results suggest that the attenuation of certain aspects of neuroplasticity following maturation may be due to the reduction of NMDAR-mediated gene transcription and a saturation of ERK1/2 activity.
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Affiliation(s)
- Xianju Zhou
- Department of Physiology, Michigan State University, East Lansing, Michigan 48824, USA
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18
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Hsu YY, Liu CM, Tsai HH, Jong YJ, Chen IJ, Lo YC. KMUP-1 attenuates serum deprivation-induced neurotoxicity in SH-SY5Y cells: roles of PKG, PI3K/Akt and Bcl-2/Bax pathways. Toxicology 2009; 268:46-54. [PMID: 19962417 DOI: 10.1016/j.tox.2009.11.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 11/04/2009] [Accepted: 11/27/2009] [Indexed: 11/19/2022]
Abstract
Aging populations with neurodegenerative disorders will gradually become a greater problem for society. Serum deprivation-induced cell death is recognized as one of the standard models for the study of neurotoxicity. Increasing evidence indicates that cGMP/PKG pathway may play a rescue role in serum deprivation-induced toxicity. The aim of this study was to investigate protective effects of KMUP-1, an enhancer of cGMP/PKG signaling on serum deprivation-induced neurotoxicity in SH-SY5Y neuroblastoma cells. Under normal serum condition, KMUP-1 enhanced protein expression of nNOS, PKG and sGCalpha1, increased intracellular cyclic GMP level, and attenuated PDE5 expression. KMUP-1 also increased expression of BDNF and Bcl-2, but it did not affect Bax expression. The phosphorylation of Akt and CREB induced by KMUP-1 was inhibited by tyrosine kinase (TrK) inhibitor K252a and phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, respectively. Under serum deprivation condition, flow cytometric analysis using Annexin V showed KMUP-1 increased cell viability, but lacked protective effects in the presence of nitric oxide synthase inhibitor l-NAME, PKG inhibitor Rp-8-pCPT-cGMPS or LY294002. KMUP-1 not only enhanced expression of nNOS, sGCalpha1, PKG, p-CREB, p-Akt and Bcl-2, but also attenuated Bax expression in serum deprivation-treated cultures. In conclusion, cGMP/PKG, PI3K/Akt/CREB and Bcl-2/Bax signals play critical roles in the neuroprotective effects of KMUP-1 on serum deprivation-induced toxicity.
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Affiliation(s)
- Ya-Yun Hsu
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
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19
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BDNF-mediated cerebellar granule cell development is impaired in mice null for CaMKK2 or CaMKIV. J Neurosci 2009; 29:8901-13. [PMID: 19605628 DOI: 10.1523/jneurosci.0040-09.2009] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The Ca(2+)/calmodulin-activated kinases CaMKK2 and CaMKIV are highly expressed in the brain where they play important roles in activating intracellular responses to elevated Ca(2+). To address the biological functions of Ca(2+) signaling via these kinases during brain development, we have examined cerebellar development in mice null for CaMKK2 or CaMKIV. Here, we demonstrate that CaMKK2/CaMKIV-dependent phosphorylation of cAMP response element-binding protein (CREB) correlates with Bdnf transcription, which is required for normal development of cerebellar granule cell neurons. We show in vivo and in vitro that the absence of either CaMKK2 or CaMKIV disrupts the ability of developing cerebellar granule cells in the external granule cell layer to cease proliferation and begin migration to the internal granule cell layer. Furthermore, loss of CaMKK2 or CaMKIV results in decreased CREB phosphorylation (pCREB), Bdnf exon I and IV-containing mRNAs, and brain-derived neurotrophic factor (BDNF) protein in cerebellar granule cell neurons. Reexpression of CaMKK2 or CaMKIV in granule cells that lack CaMKK2 or CaMKIV, respectively, restores pCREB and BDNF to wild-type levels and addition of BDNF rescues granule cell migration in vitro. These results reveal a previously undefined role for a CaMKK2/CaMKIV cascade involved in cerebellar granule cell development and show specifically that Ca(2+)-dependent regulation of BDNF through CaMKK2/CaMKIV is required for this process.
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20
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NMDA-mediated and self-induced bdnf exon IV transcriptions are differentially regulated in cultured cortical neurons. Neurochem Int 2009; 54:385-92. [DOI: 10.1016/j.neuint.2009.01.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Zheng F, Luo Y, Wang H. Regulation of brain-derived neurotrophic factor-mediated transcription of the immediate early gene Arc by intracellular calcium and calmodulin. J Neurosci Res 2009; 87:380-92. [PMID: 18798281 DOI: 10.1002/jnr.21863] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The induction of the immediate early gene Arc is strongly implicated in synaptic plasticity. Although the role of ERK has been demonstrated, the regulation of Arc expression is largely unknown. In this study, we investigated the major signaling pathways underlying brain-derived neurotrophic factor (BDNF)-mediated Arc transcription in cultured cortical neurons. The BDNF-stimulated Arc transcription was regulated solely by the Ras-Raf-MAPK signaling through ERK, but not by phosphoinositide 3-kinase (PI3K) and PLC-gamma activities. Although it was demonstrated that BDNF might promote calcium entry through calcium channels and NMDA receptors, chelating extracellular calcium with EGTA failed to block Arc transcription. In contrast, chelating intracellular calcium ([Ca(2+)](i)) by BAPTA-AM abolished BDNF-mediated Arc up-regulation. Surprisingly, BAPTA-AM did not block ERK activation, indicating that [Ca(2+)](i) and Ras-Raf-MAPK are not coupled, and the activation of ERK alone is not sufficient to up-regulate Arc transcription. Moreover, we found that inhibition of calmodulin (CaM) by W13 blocked both Arc transcription and ERK activation, revealing a Ca(2+)-independent function of CaM. These data suggested novel functions of [Ca(2+)](i) and CaM in BDNF signaling. Comparison of the Arc transcription profiles between Ca(2+)-stimulated and BDNF-stimulated neurons demonstrated that the regulatory mechanisms were distinctively tailored to the complex features of neuronal activity. Specifically, PI3K and CaM-dependent protein kinase (CaMK) activity were required for Ca(2+)-stimulated Arc transcription through regulating ERK signaling. Such cross-talks between PI3K, CaMK, and ERK was absent in BDNF-stimulated neurons.
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Affiliation(s)
- Fei Zheng
- Department of Biochemistry, Michigan State University, East Lansing, Michigan, USA
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22
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Jain P, Bhalla US. Signaling logic of activity-triggered dendritic protein synthesis: an mTOR gate but not a feedback switch. PLoS Comput Biol 2009; 5:e1000287. [PMID: 19242559 PMCID: PMC2647780 DOI: 10.1371/journal.pcbi.1000287] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Accepted: 01/05/2009] [Indexed: 12/23/2022] Open
Abstract
Changes in synaptic efficacy are believed to form the cellular basis for memory. Protein synthesis in dendrites is needed to consolidate long-term synaptic changes. Many signals converge to regulate dendritic protein synthesis, including synaptic and cellular activity, and growth factors. The coordination of these multiple inputs is especially intriguing because the synthetic and control pathways themselves are among the synthesized proteins. We have modeled this system to study its molecular logic and to understand how runaway feedback is avoided. We show that growth factors such as brain-derived neurotrophic factor (BDNF) gate activity-triggered protein synthesis via mammalian target of rapamycin (mTOR). We also show that bistability is unlikely to arise from the major protein synthesis pathways in our model, even though these include several positive feedback loops. We propose that these gating and stability properties may serve to suppress runaway activation of the pathway, while preserving the key role of responsiveness to multiple sources of input. Memory formation involves the controlled production of new proteins close to the site of input stimuli on nerve cells. Strong inputs, in combination with growth factors, stimulate the synthesis of several kinds of synaptic proteins. These new proteins are believed to participate in remodeling the contacts between cells. This gives rise to a potentially unstable situation of a self-modifying cellular machine, because the new proteins rebuild their own inputs and their own production machinery. We have analyzed these interactions by modeling multiple inputs and the process of self-modifying feedback. We find that runaway modifications are prevented in two ways: first, a molecule called mTOR acts as a gate to suppress synthesis except under very tightly regulated conditions. Second, the feedback processes operate in a range where it is very unlikely that they can give rise to runaway buildup. Thus, the system avoids instability even though it is capable of modifying itself in response to many kinds of inputs.
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Affiliation(s)
- Pragati Jain
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Upinder S. Bhalla
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
- * E-mail:
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