1
|
Dahleh MMM, Mello CF, Ferreira J, Rubin MA, Prigol M, Guerra GP. CaMKIIα mediates spermidine-induced memory enhancement in rats: A potential involvement of PKA/CREB pathway. Pharmacol Biochem Behav 2024; 240:173774. [PMID: 38648866 DOI: 10.1016/j.pbb.2024.173774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/17/2024] [Accepted: 04/17/2024] [Indexed: 04/25/2024]
Abstract
Memory consolidation is associated with the regulation of protein kinases, which impact synaptic functions and promote synaptogenesis. The administration of spermidine (SPD) has been shown to modulate major protein kinases associated with memory improvement, including the Ca2+-dependent protein kinase (PKC) and cAMP-dependent protein kinase (PKA), key players in the cAMP response element-binding protein (CREB) activation. Nevertheless, the initial mechanism underlying SPD-mediated memory consolidation remains unknown, as we hypothesize a potential involvement of the memory consolidation precursor, Ca2+/calmodulin-dependent protein kinase II-α (CaMKIIα), in this process. Based on this, our study aimed to investigate potential interactions among PKC, PKA, and CREB activation, mediated by CaMKIIα activation, in order to elucidate the SPD memory consolidation pathway. Our findings suggest that the post-training administration of the CaMKII inhibitor, KN-62 (0.25 nmol, intrahippocampal), prevented the memory enhancement induced by SPD (0.2 nmol, intrahippocampal) in the inhibitory avoidance task. Through western immunoblotting, we observed that phosphorylation of CaMKIIα in the hippocampus was facilitated 15 min after intrahippocampal SPD administration, resulting in the activation of PKA and CREB, 180 min after infusion, suggesting a possible sequential mechanism, since SPD with KN-62 infusion leads to a downregulation in CaMKIIα/PKA/CREB pathway. However, KN-62 does not alter the memory-facilitating effect of SPD on PKC, possibly demonstrating a parallel cascade in memory acquisition via PKA, without modulating CAMKIIα. These results suggest that memory enhancement induced by SPD administration involves crosstalk between CaMKIIα and PKA/CREB, with no PKC interaction.
Collapse
Affiliation(s)
- Mustafa Munir Mustafa Dahleh
- Laboratório de Avaliações Farmacológicas e Toxicológicas Aplicadas às Moléculas Bioativas - LaftamBio, Universidade Federal do Pampa - Campus Itaqui, 97650-000, Itaqui, RS, Brazil
| | - Carlos Fernando Mello
- Departamento de Fisiologia e Farmacologia, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil
| | - Juliano Ferreira
- Departamento de Farmacologia, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Maribel Antonello Rubin
- Programa de Pós Graduação em Ciências Biológicas: Bioquímica Toxicológica, Departamento de Bioquímica e Biologia Molecular, Centro de Ciências Naturais e Exatas, Laboratório de Neuropsicofarmacologia Universidade Federal de Santa Maria, Santa Maria, Brazil
| | - Marina Prigol
- Laboratório de Avaliações Farmacológicas e Toxicológicas Aplicadas às Moléculas Bioativas - LaftamBio, Universidade Federal do Pampa - Campus Itaqui, 97650-000, Itaqui, RS, Brazil
| | - Gustavo Petri Guerra
- Laboratório de Avaliações Farmacológicas e Toxicológicas Aplicadas às Moléculas Bioativas - LaftamBio, Universidade Federal do Pampa - Campus Itaqui, 97650-000, Itaqui, RS, Brazil.
| |
Collapse
|
2
|
Bohley M, Leroux JC. Gastrointestinal Permeation Enhancers Beyond Sodium Caprate and SNAC - What is Coming Next? ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2400843. [PMID: 38884149 DOI: 10.1002/advs.202400843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/13/2024] [Indexed: 06/18/2024]
Abstract
Oral peptide delivery is trending again. Among the possible reasons are the recent approvals of two oral peptide formulations, which represent a huge stride in the field. For the first time, gastrointestinal (GI) permeation enhancers (PEs) are leveraged to overcome the main limitation of oral peptide delivery-low permeability through the intestinal epithelium. Despite some success, the application of current PEs, such as salcaprozate sodium (SNAC), sodium caprylate (C8), and sodium caprate (C10), is generally resulting in relatively low oral bioavailabilities (BAs)-even for carefully selected therapeutics. With several hundred peptide-based drugs presently in the pipeline, there is a huge unmet need for more effective PEs. Aiming to provide useful insights for the development of novel PEs, this review summarizes the biological hurdles to oral peptide delivery with special emphasis on the epithelial barrier. It describes the concepts and action modes of PEs and mentions possible new targets. It further states the benchmark that is set by current PEs, while critically assessing and evaluating emerging PEs regarding translatability, safety, and efficacy. Additionally, examples of novel PEs under preclinical and clinical evaluation and future directions are discussed.
Collapse
Affiliation(s)
- Marilena Bohley
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, 8093, Switzerland
| | - Jean-Christophe Leroux
- Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, 8093, Switzerland
| |
Collapse
|
3
|
Ramirez-Velez I, Belardi B. Storming the gate: New approaches for targeting the dynamic tight junction for improved drug delivery. Adv Drug Deliv Rev 2023; 199:114905. [PMID: 37271282 PMCID: PMC10999255 DOI: 10.1016/j.addr.2023.114905] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/20/2023] [Accepted: 05/29/2023] [Indexed: 06/06/2023]
Abstract
As biologics used in the clinic outpace the number of new small molecule drugs, an important challenge for their efficacy and widespread use has emerged, namely tissue penetrance. Macromolecular drugs - bulky, high-molecular weight, hydrophilic agents - exhibit low permeability across biological barriers. Epithelial and endothelial layers, for example within the gastrointestinal tract or at the blood-brain barrier, present the most significant obstacle to drug transport. Within epithelium, two subcellular structures are responsible for limiting absorption: cell membranes and intercellular tight junctions. Previously considered impenetrable to macromolecular drugs, tight junctions control paracellular flux and dictate drug transport between cells. Recent work, however, has shown tight junctions to be dynamic, anisotropic structures that can be targeted for delivery. This review aims to summarize new approaches for targeting tight junctions, both directly and indirectly, and to highlight how manipulation of tight junction interactions may help usher in a new era of precision drug delivery.
Collapse
Affiliation(s)
- Isabela Ramirez-Velez
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, United States
| | - Brian Belardi
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX 78712, United States.
| |
Collapse
|
4
|
Mäki-Marttunen T, Blackwell KT, Akkouh I, Shadrin A, Valstad M, Elvsåshagen T, Linne ML, Djurovic S, Einevoll GT, Andreassen OA. Genetic mechanisms for impaired synaptic plasticity in schizophrenia revealed by computational modelling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.14.544920. [PMID: 37398070 PMCID: PMC10312778 DOI: 10.1101/2023.06.14.544920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Schizophrenia phenotypes are suggestive of impaired cortical plasticity in the disease, but the mechanisms of these deficits are unknown. Genomic association studies have implicated a large number of genes that regulate neuromodulation and plasticity, indicating that the plasticity deficits have a genetic origin. Here, we used biochemically detailed computational modelling of post-synaptic plasticity to investigate how schizophrenia-associated genes regulate long-term potentiation (LTP) and depression (LTD). We combined our model with data from post-mortem mRNA expression studies (CommonMind gene-expression datasets) to assess the consequences of altered expression of plasticity-regulating genes for the amplitude of LTP and LTD. Our results show that the expression alterations observed post mortem, especially those in anterior cingulate cortex, lead to impaired PKA-pathway-mediated LTP in synapses containing GluR1 receptors. We validated these findings using a genotyped EEG dataset where polygenic risk scores for synaptic and ion channel-encoding genes as well as modulation of visual evoked potentials (VEP) were determined for 286 healthy controls. Our results provide a possible genetic mechanism for plasticity impairments in schizophrenia, which can lead to improved understanding and, ultimately, treatment of the disorder.
Collapse
Affiliation(s)
- Tuomo Mäki-Marttunen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Kim T Blackwell
- The Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA, USA
| | - Ibrahim Akkouh
- Norwegian Centre for Mental Disorders Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Alexey Shadrin
- Norwegian Centre for Mental Disorders Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
- K.G. Jebsen Centre for Neurodevelopmental disorders, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Mathias Valstad
- Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Norway
| | - Tobjørn Elvsåshagen
- Norwegian Centre for Mental Disorders Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
- Department of Neurology, Oslo University Hospital, Norway
| | - Marja-Leena Linne
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Srdjan Djurovic
- Norwegian Centre for Mental Disorders Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
- K.G. Jebsen Centre for Neurodevelopmental disorders, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Gaute T Einevoll
- Department of Physics, Norwegian University of Life Sciences, Ås, Norway
- Department of Physics, University of Oslo, Oslo, Norway
| | - Ole A Andreassen
- Norwegian Centre for Mental Disorders Research (NORMENT), Division of Mental Health and Addiction, Oslo University Hospital, Oslo, Norway
- Norwegian Centre for Mental Disorders Research (NORMENT), Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| |
Collapse
|
5
|
Chang C, Yang Y, Zhou L, Baiyin B, Liu Z, Guo L, Ma F, Wang J, Chai Y, Shi C, Zhang W. Candidate Genes and Gene Networks Change with Age in Japanese Black Cattle by Blood Transcriptome Analysis. Genes (Basel) 2023; 14:504. [PMID: 36833431 PMCID: PMC9956108 DOI: 10.3390/genes14020504] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Age is an important physiological factor that affects the metabolism and immune function of beef cattle. While there have been many studies using the blood transcriptome to study the effects of age on gene expression, few have been reported on beef cattle. To this end, we used the blood transcriptomes of Japanese black cattle at different ages as the study subjects and screened 1055, 345, and 1058 differential expressed genes (DEGs) in the calf vs. adult, adult vs. old, and calf vs. old comparison groups, respectively. The weighted co-expression network consisted of 1731 genes. Finally, blue, brown, and yellow age-specific modules were obtained, in which genes were enriched in signaling pathways related to growth and development and immune metabolic dysfunction, respectively. Protein-protein interaction (PPI) analysis showed gene interactions in each specific module, and 20 of the highest connectivity genes were chosen as potential hub genes. Finally, we identified 495, 244, and 1007 genes by exon-wide selection signature (EWSS) analysis of different comparison groups. Combining the results of hub genes, we found that VWF, PARVB, PRKCA, and TGFB1I1 could be used as candidate genes for growth and development stages of beef cattle. CORO2B and SDK1 could be used as candidate marker genes associated with aging. In conclusion, by comparing the blood transcriptome of calves, adult cattle, and old cattle, the candidate genes related to immunity and metabolism affected by age were identified, and the gene co-expression network of different age stages was constructed. It provides a data basis for exploring the growth, development, and aging of beef cattle.
Collapse
Affiliation(s)
- Chencheng Chang
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Yanda Yang
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Le Zhou
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Batu Baiyin
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Zaixia Liu
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Lili Guo
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Fengying Ma
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Jie Wang
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Yuan Chai
- College of Agronomy Animal Husbandry and Bioengineering, Xing’an Vocational and Technical College, Ulanhot 137400, China
| | - Caixia Shi
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
| | - Wenguang Zhang
- College of Animal Science, Inner Mongolia Agricultural University, Hohhot 010018, China
- College of Life Science, Inner Mongolia Agricultural University, Hohhot 010018, China
- Inner Mongolia Engineering Research Center of Genomic Big Data for Agriculture, Hohhot 010018, China
| |
Collapse
|
6
|
Brunner J, Schvartz D, Gouiller A, Hainard A, Borchard G. Impact of peptide permeation enhancer on tight junctions opening cellular mechanisms. Biochem Biophys Rep 2022; 32:101375. [PMID: 36324528 PMCID: PMC9618981 DOI: 10.1016/j.bbrep.2022.101375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 10/03/2022] [Accepted: 10/24/2022] [Indexed: 11/09/2022] Open
Abstract
The myristoylated pentapeptide, L-R5, contains an amino acid sequence of the zeta inhibitory peptide (ZIP) portion (pseudosubstrate) of protein kinase C zeta (PKC ζ). As PKC ζ is involved in the modulation of epithelial tight junctions (TJs) through the phosphorylation of TJ proteins, L-R5 was suggested to interact with the enzyme resulting in the enhancement of paracellular permeability. This study shows that L-R5 does not bind to the enzyme but interacts directly with TJ proteins. We show here that the binding of PKC ζ to occludin and its successive phosphorylation is prevented by L-R5, which leads to TJ disruption and enhanced epithelial permeability. Although L-R5 did not show any in vitro cytotoxicity, a proteomics study revealed that L-R5 interferes with other regulatory pathways, e.g., apoptosis and immune response. We suggest that structural modification of the peptide may increase the specificity TJ protein-peptide interaction. Microscale thermophoresis (MST) showed robust results for protein bindings. The competitivity of L-R5 peptide for the binding of occludin-PKC zeta was shown. Tight junctions proteins expression was decreased due to L-R5 peptide. Multiple other mechanisms can be explored to use L-R5 for other therapies.
Collapse
Affiliation(s)
- Joël Brunner
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Domitille Schvartz
- Proteomics Core Facility, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Aurélie Gouiller
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland
| | - Alexandre Hainard
- Proteomics Core Facility, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Gerrit Borchard
- School of Pharmaceutical Sciences, University of Geneva, Geneva, Switzerland,Corresponding author.
| |
Collapse
|
7
|
Liu J. Involvement of PKMζ in Stress Response and Depression. Front Cell Neurosci 2022; 16:907767. [PMID: 35669107 PMCID: PMC9163780 DOI: 10.3389/fncel.2022.907767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
The stress system in the brain plays a pivotal role in keeping humans and animals from harmful stimuli. However, excessive stress will cause maladaptive changes to the stress system and lead to depression. Despite the high prevalence of depression, the treatment remains limited. PKMζ, an atypical PKC isoform, has been demonstrated to play a crucial role in maintaining long-term potentiation and memory. Recent evidence shows that PKMζ is also involved in stress response and depressive-like behavior. In particular, it was demonstrated that stress that resulted in depressive-like behavior could decrease the expression of PKMζ in the prefrontal cortex, which could be reversed by antidepressants. Importantly, modulation of PKMζ expression could regulate depressive-like behaviors and the actions of antidepressants. These data suggested that PKMζ could be a molecular target for developing novel antidepressants. Here, I review the advance on the role of PKMζ in mediating stress response and its involvement in the development of depression.
Collapse
Affiliation(s)
- Jianfeng Liu
- Department of Pharmacology, School of Pharmacy, Nantong University, Nantong, China
| |
Collapse
|
8
|
Zou D, Li Q, Pan W, Chen P, Sun M, Bao X. A novel non‑selective atypical PKC agonist could protect neuronal cell line from Aβ‑oligomer induced toxicity by suppressing Aβ generation. Mol Med Rep 2022; 25:153. [PMID: 35244193 PMCID: PMC8941380 DOI: 10.3892/mmr.2022.12669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/15/2022] [Indexed: 12/04/2022] Open
Abstract
Atypical protein kinase C (aPKCs) serve key functions in embryonic development by regulating apical-basal polarity. Previous studies have shed light on their roles during adulthood, especially in the development of Alzheimer's disease (AD). Although the crystal structure of PKCι has been resolved, an agonist of aPKCs remains to be discovered. In the present study, by using the Discovery Studio program and LibDock methodology, a small molecule library (K66-X4436 KINA Set) of compounds were screened for potential binding to PKCι. Subsequently, the computational docking results were validated using affinity selection-mass spectrometry, before in vitro kinase activity was used to determine the function of the hit compounds. A cell-based model assay that can mimic the pathology of AD was then established and used to assess the function of these hit compounds. As a result, the aPKC agonist Z640 was identified, which could bind to PKCι in silico, in vitro and in this cell-based model. Z640 was further confirmed as a non-selective aPKC agonist that can activate the kinase activity of both PKCι and PKCζ. In the cell-based assay, Z640 was found to protect neuronal cell lines from amyloid-β (Aβ) oligomer-induced cell death by reducing reactive oxygen species production and restore mitochondrial function. In addition, Z640 could reduce Aβ40 generation in a dose-dependent manner and shift amyloid precursor protein processing towards the non-amyloid pathway. To conclude, the present study is the first, to the best of the authors' knowledge to identify an aPKC agonist by combining computer-assisted drug discovery and cell-based assays. The present study also revealed that aPKC agonists have therapeutic potential for the treatment of AD.
Collapse
Affiliation(s)
- Dongmei Zou
- School of Pharmacy, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Qian Li
- Department of Biology, College of Staten Island, Staten Island, NY 10314, USA
| | - Wenyang Pan
- School of Pharmacy, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Peng Chen
- School of Pharmacy, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Miao Sun
- School of Pharmacy, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Xiaofeng Bao
- School of Pharmacy, Nantong University, Nantong, Jiangsu 226001, P.R. China
| |
Collapse
|
9
|
Activators and Inhibitors of Protein Kinase C (PKC): Their Applications in Clinical Trials. Pharmaceutics 2021; 13:pharmaceutics13111748. [PMID: 34834162 PMCID: PMC8621927 DOI: 10.3390/pharmaceutics13111748] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 02/05/2023] Open
Abstract
Protein kinase C (PKC), a family of phospholipid-dependent serine/threonine kinase, is classed into three subfamilies based on their structural and activation characteristics: conventional or classic PKC isozymes (cPKCs; α, βI, βII, and γ), novel or non-classic PKC isozymes (nPKCs; δ, ε, η, and θ), and atypical PKC isozymes (aPKCs; ζ, ι, and λ). PKC inhibitors and activators are used to understand PKC-mediated intracellular signaling pathways and for the diagnosis and treatment of various PKC-associated diseases, such as cancers, neurological diseases, cardiovascular diseases, and infections. Many clinical trials of PKC inhibitors in cancers showed no significant clinical benefits, meaning that there is a limitation to design a cancer therapeutic strategy targeting PKC alone. This review will focus on the activators and inhibitors of PKC and their applications in clinical trials.
Collapse
|
10
|
Bouvet M, Dubois-Deruy E, Turkieh A, Mulder P, Peugnet V, Chwastyniak M, Beseme O, Dechaumes A, Amouyel P, Richard V, Lamblin N, Pinet F. Desmin aggrephagy in rat and human ischemic heart failure through PKCζ and GSK3β as upstream signaling pathways. Cell Death Discov 2021; 7:153. [PMID: 34226534 PMCID: PMC8257599 DOI: 10.1038/s41420-021-00549-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/29/2021] [Accepted: 06/01/2021] [Indexed: 12/21/2022] Open
Abstract
Post-translational modifications of cardiac proteins could participate to left contractile dysfunction resulting in heart failure. Using a rat model of ischemic heart failure, we showed an accumulation of phosphorylated desmin leading to toxic aggregates in cardiomyocytes, but the cellular mechanisms are unknown. The same rat model was used to decipher the kinases involved in desmin phosphorylation and the proteolytic systems present in rat and human failing hearts. We used primary cultures of neonate rat cardiomyocytes for testing specific inhibitors of kinases and for characterizing the autophagic processes able to clear desmin aggregates. We found a significant increase of active PKCζ, no modulation of ubitiquitin-proteasome system, a defect in macroautophagy, and an activation of chaperone-mediated autophagy in heart failure rats. We validated in vitro that PKCζ inhibition induced a significant decrease of GSK3β and of soluble desmin. In vitro activation of ubiquitination of proteins and of chaperone-mediated autophagy is able to decrease soluble and insoluble forms of desmin in cardiomyocytes. These data demonstrate a novel signaling pathway implicating activation of PKCζ in desmin phosphorylation associated with a defect of proteolytic systems in ischemic heart failure, leading to desmin aggrephagy. Our in vitro data demonstrated that ubiquitination of proteins and chaperone-mediated autophagy are required for eliminating desmin aggregates with the contribution of its chaperone protein, α-crystallin Β-chain. Modulation of the kinases involved under pathological conditions may help preserving desmin intermediate filaments structure and thus protect the structural integrity of contractile apparatus of cardiomyocytes by limiting desmin aggregates formation.
Collapse
Affiliation(s)
- Marion Bouvet
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Emilie Dubois-Deruy
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Annie Turkieh
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Paul Mulder
- Normandie Univ, UNIROUEN, Inserm U1096, FHU-REMOD-VHF, 76000, Rouen, France
| | - Victoriane Peugnet
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Maggy Chwastyniak
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Olivia Beseme
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Arthur Dechaumes
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Philippe Amouyel
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Vincent Richard
- Normandie Univ, UNIROUEN, Inserm U1096, FHU-REMOD-VHF, 76000, Rouen, France
| | - Nicolas Lamblin
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France
| | - Florence Pinet
- INSERM, Univ. Lille, CHU Lille, Institut Pasteur de Lille, U1167 - RID-AGE - Facteurs de risque et déterminants moléculaires des maladies liées au vieillissement, F-59000, Lille, France.
| |
Collapse
|
11
|
Bernabo M, Haubrich J, Gamache K, Nader K. Memory Destabilization and Reconsolidation Dynamically Regulate the PKMζ Maintenance Mechanism. J Neurosci 2021; 41:4880-4888. [PMID: 33888608 PMCID: PMC8260165 DOI: 10.1523/jneurosci.2093-20.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 11/21/2022] Open
Abstract
Useful memory must balance between stability and malleability. This puts effective memory storage at odds with plasticity processes, such as reconsolidation. What becomes of memory maintenance processes during synaptic plasticity is unknown. Here we examined the fate of the memory maintenance protein PKMζ during memory destabilization and reconsolidation in male rats. We found that NMDAR activation and proteasome activity induced a transient reduction in PKMζ protein following retrieval. During reconsolidation, new PKMζ was synthesized to re-store the memory. Failure to synthesize new PKMζ during reconsolidation impaired memory but uninterrupted PKMζ translation was not necessary for maintenance itself. Finally, NMDAR activation was necessary to render memories vulnerable to the amnesic effect of PKMζ-antisense. These findings outline a transient disruption and renewal of the PKMζ memory maintenance mechanism during plasticity. We argue that dynamic changes in PKMζ protein levels can serve as an exemplary model of the molecular changes underlying memory destabilization and reconsolidation.SIGNIFICANCE STATEMENT Maintenance of long-term memory relies on the persistent activity of PKMζ. However, after retrieval, memories can become transiently destabilized and must be reconsolidated within a few hours to persist. During this period of plasticity, what happens to maintenance processes, such as those involving PKMζ, is unknown. Here we describe dynamic changes to PKMζ expression during both destabilization and reconsolidation of auditory fear memory in the amygdala. We show that destabilization induces a NMDAR- and proteasome-dependent loss of synaptic PKMζ and that reconsolidation requires synthesis of new PKMζ. This work provides clear evidence that memory destabilization disrupts ongoing synaptic maintenance processes which are restored during reconsolidation.
Collapse
Affiliation(s)
- Matteo Bernabo
- Integrated Program in Neuroscience, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Josue Haubrich
- Department of Psychology, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Karine Gamache
- Department of Psychology, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Karim Nader
- Department of Psychology, McGill University, Montreal, Quebec H3A 1B1, Canada
| |
Collapse
|
12
|
Brunner J, Ragupathy S, Borchard G. Target specific tight junction modulators. Adv Drug Deliv Rev 2021; 171:266-288. [PMID: 33617902 DOI: 10.1016/j.addr.2021.02.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 02/07/2023]
Abstract
Intercellular tight junctions represent a formidable barrier against paracellular drug absorption at epithelia (e.g., nasal, intestinal) and the endothelium (e.g., blood-brain barrier). In order to enhance paracellular transport of drugs and increase their bioavailability and organ deposition, active excipients modulating tight junctions have been applied. First-generation of permeation enhancers (PEs) acted by unspecific interactions, while recently developed PEs address specific physiological mechanisms. Such target specific tight junction modulators (TJMs) have the advantage of a defined specific mechanism of action. To date, merely a few of these novel active excipients has entered into clinical trials, as their lack in safety and efficiency in vivo often impedes their commercialisation. A stronger focus on the development of such active excipients would result in an economic and therapeutic improvement of current and future drugs.
Collapse
Affiliation(s)
- Joël Brunner
- Section of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1211 Geneva, Switzerland
| | - Sakthikumar Ragupathy
- Section of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1211 Geneva, Switzerland
| | - Gerrit Borchard
- Section of Pharmaceutical Sciences, Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1211 Geneva, Switzerland.
| |
Collapse
|
13
|
Patel H, Zamani R. The role of PKMζ in the maintenance of long-term memory: a review. Rev Neurosci 2021; 32:481-494. [PMID: 33550786 DOI: 10.1515/revneuro-2020-0105] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/27/2020] [Indexed: 11/15/2022]
Abstract
Long-term memories are thought to be stored in neurones and synapses that undergo physical changes, such as long-term potentiation (LTP), and these changes can be maintained for long periods of time. A candidate enzyme for the maintenance of LTP is protein kinase M zeta (PKMζ), a constitutively active protein kinase C isoform that is elevated during LTP and long-term memory maintenance. This paper reviews the evidence and controversies surrounding the role of PKMζ in the maintenance of long-term memory. PKMζ maintains synaptic potentiation by preventing AMPA receptor endocytosis and promoting stabilisation of dendritic spine growth. Inhibition of PKMζ, with zeta-inhibitory peptide (ZIP), can reverse LTP and impair established long-term memories. However, a deficit of memory retrieval cannot be ruled out. Furthermore, ZIP, and in high enough doses the control peptide scrambled ZIP, was recently shown to be neurotoxic, which may explain some of the effects of ZIP on memory impairment. PKMζ knockout mice show normal learning and memory. However, this is likely due to compensation by protein-kinase C iota/lambda (PKCι/λ), which is normally responsible for induction of LTP. It is not clear how, or if, this compensatory mechanism is activated under normal conditions. Future research should utilise inducible PKMζ knockdown in adult rodents to investigate whether PKMζ maintains memory in specific parts of the brain, or if it represents a global memory maintenance molecule. These insights may inform future therapeutic targets for disorders of memory loss.
Collapse
Affiliation(s)
- Hamish Patel
- University of Exeter Medical School, Exeter, EX1 2LU, UK
| | - Reza Zamani
- University of Exeter Medical School, Exeter, EX1 2LU, UK
| |
Collapse
|
14
|
Lee-Rivera I, López E, Alvarez-Arce A, López-Colomé AM. The PKC-ζ pseudosubstrate peptide induces glutamate release from retinal pigment epithelium cells through kinase- independent activation of Best1. Life Sci 2020; 265:118860. [PMID: 33301813 DOI: 10.1016/j.lfs.2020.118860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/19/2020] [Accepted: 12/01/2020] [Indexed: 10/22/2022]
Abstract
AIMS The retinal pigment epithelium (RPE) is a highly specialized cell monolayer, that plays a key role in the maintenance of photoreceptor function and the blood-retina barrier (BRB). In this study, we found that a myristoylated pseudosubstrate of PKC-ζ (PKCζ PS), considered as a PKC-ζ inhibitor, plays a distinct role in RPE. MAIN METHODS We demonstrated that PKCζ PS stimulates the release of Glutamate (Glu) using in vitro3H-Glutamate release experiments. By western blot, kinase assays, and Fluoresence Ca+2 Concentration Measurements, we determined the cellular mechanisms involved in such release. KEY FINDINGS Surprisingly, PKCζ PS has no effect on either phosphorylation of T560, essential for catalytic activity, nor it has an effect on kinase activity. It induces the dose-dependent release of Glu by increasing intracellular Ca+2 levels. Interestingly, this release was not observed upon stimulation by other non-competitive PKC-ζ inhibitors. We here demonstrated that the PKCζ PS stimulates the release of Glutamate from RPE by activating the Ca2+-dependent Cl channel Bestrophin 1 (Best1). SIGNIFICANCE These results question PKCζ PS specificity as an inhibitor of this enzyme. Furthermore, the present results underline the relevance of clarifying the molecular mechanisms involved in glutamate release from the retina under conditions derived from excitotoxic stimuli.
Collapse
Affiliation(s)
- Irene Lee-Rivera
- Department of Molecular Neuropathology, Instituto de Fisiología Celular, UNAM, Apartado Postal 70-253, Ciudad Universitaria, México City, CdMx, Mexico
| | - Edith López
- Department of Molecular Neuropathology, Instituto de Fisiología Celular, UNAM, Apartado Postal 70-253, Ciudad Universitaria, México City, CdMx, Mexico
| | - Alejandro Alvarez-Arce
- Department of Molecular Neuropathology, Instituto de Fisiología Celular, UNAM, Apartado Postal 70-253, Ciudad Universitaria, México City, CdMx, Mexico
| | - Ana María López-Colomé
- Department of Molecular Neuropathology, Instituto de Fisiología Celular, UNAM, Apartado Postal 70-253, Ciudad Universitaria, México City, CdMx, Mexico.
| |
Collapse
|
15
|
Nakagawasai O, Lin JR, Odaira T, Takahashi K, Nemoto W, Moriguchi S, Yabuki Y, Kobayakawa Y, Fukunaga K, Nakada M, Tan-No K. Scabronine G Methyl Ester Improves Memory-Related Behavior and Enhances Hippocampal Cell Proliferation and Long-Term Potentiation via the BDNF-CREB Pathway in Olfactory Bulbectomized Mice. Front Pharmacol 2020; 11:583291. [PMID: 33281604 PMCID: PMC7689418 DOI: 10.3389/fphar.2020.583291] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/30/2020] [Indexed: 11/30/2022] Open
Abstract
A previous study reported that scabronine G methyl ester (SG-ME) potentially enhances the in vitro secretion of neurotrophic factors such as nerve growth factor via the protein kinase C (PKC)-ζ pathway. However, it remains unknown whether SG-ME can improve cognitive dysfunctions in olfactory bulbectomized (OBX) mice. To address this question, we evaluated SG-ME-treated and untreated OBX mice in a passive avoidance test. We also investigated potential effects of SG-ME on several parameters: cell proliferation and cAMP response element-binding protein (CREB) phosphorylation in the hippocampal dentate gyrus by immunohistochemistry, brain-derived neurotrophic factor (BDNF) levels in the hippocampus by Western blotting, p-CREB levels in the hippocampus by MapAnalyzer, and long-term potentiation (LTP) by electrophysiology. On the 14th day after surgery OBX mice showed altered passive avoidance and decreases in both cell proliferation and long-term potentiation in the hippocampus, while these changes were reversed by SG-ME (20 μg/mouse) 24 h after the treatment. The improvement in memory deficits was prevented when SG-ME was co-administeredwith either zeta inhibitory peptide (PKC-ζ inhibitor), anti-BDNF antibody, ANA-12 (TrkB antagonist), U0126 (MEK inhibitor), H-89 (PKA inhibitor), LY294002 (PI3K inhibitor) or KN-93 (CaMKII inhibitor). We found that SG-ME enhanced brain-derived neurotrophic factor and p-CREB levels in the hippocampus while p-CREB was localized in neurons, but not in astrocytes nor microglial cells. These findings revealed the potential of SG-ME in improving memory impairments by enhancing cell proliferation and LTP via activation of the BDNF/CREB signaling pathway in neurons.
Collapse
Affiliation(s)
- Osamu Nakagawasai
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Jia-Rong Lin
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Takayo Odaira
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Kohei Takahashi
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Sendai, Japan.,Department of Pharmacology, School of Pharmacy, International University of Health and Welfare, Ohtawara, Japan
| | - Wataru Nemoto
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Shigeki Moriguchi
- Research Center for Pharmaceutical Development, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.,Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Yasushi Yabuki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.,Department of Genomic Neurology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto, Japan
| | - Yu Kobayakawa
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering, Waseda University, Tokyo, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Masahisa Nakada
- Department of Chemistry and Biochemistry, Faculty of Science and Engineering, Waseda University, Tokyo, Japan
| | - Koichi Tan-No
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| |
Collapse
|
16
|
p53 destabilizing protein skews asymmetric division and enhances NOTCH activation to direct self-renewal of TICs. Nat Commun 2020; 11:3084. [PMID: 32555153 PMCID: PMC7299990 DOI: 10.1038/s41467-020-16616-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Accepted: 04/28/2020] [Indexed: 01/11/2023] Open
Abstract
Tumor-initiating stem-like cells (TICs) are defective in maintaining asymmetric cell division and responsible for tumor recurrence. Cell-fate-determinant molecule NUMB-interacting protein (TBC1D15) is overexpressed and contributes to p53 degradation in TICs. Here we identify TBC1D15-mediated oncogenic mechanisms and tested the tumorigenic roles of TBC1D15 in vivo. We examined hepatocellular carcinoma (HCC) development in alcohol Western diet-fed hepatitis C virus NS5A Tg mice with hepatocyte-specific TBC1D15 deficiency or expression of non-phosphorylatable NUMB mutations. Liver-specific TBC1D15 deficiency or non-p-NUMB expression reduced TIC numbers and HCC development. TBC1D15–NuMA1 association impaired asymmetric division machinery by hijacking NuMA from LGN binding, thereby favoring TIC self-renewal. TBC1D15–NOTCH1 interaction activated and stabilized NOTCH1 which upregulated transcription of NANOG essential for TIC expansion. TBC1D15 activated three novel oncogenic pathways to promote self-renewal, p53 loss, and Nanog transcription in TICs. Thus, this central regulator could serve as a potential therapeutic target for treatment of HCC. Normal stem cells are maintained by asymmetric cell division, but this process is dysregulated in tumour initiating stem-like cells (TICs). Here, the authors show that TBC1D15 impairs the asymmetric division machinery and activates NOTCH pathway for TIC self-renewal and expansion to promote liver tumorigenesis.
Collapse
|
17
|
Reversing Cocaine-Induced Plasticity with Zeta Inhibitory Peptide. J Neurosci 2019; 39:7801-7809. [PMID: 31409665 DOI: 10.1523/jneurosci.1367-19.2019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/18/2019] [Accepted: 08/07/2019] [Indexed: 11/21/2022] Open
Abstract
Cocaine-induced plasticity persists during abstinence and is thought to underlie cue-evoked craving. Reversing this plasticity could provide an opportunity for therapeutic intervention. Converging evidence suggest that zeta inhibitory peptide (ZIP) eliminates memories for experience-dependent behaviors, including conditioned drug associations. However, the effect of ZIP on reward seeking and drug-induced plasticity is unknown. The current study examined the effect of ZIP administration in the nucleus accumbens on reinstatement (RI) of cocaine seeking, a rodent model of relapse. We demonstrate that intra-accumbal ZIP administration blocks cocaine-primed RI in rats when administered 24 h or 1 week before testing. These effects of ZIP on drug seeking are specific, as we did not see any effect of ZIP on RI of sucrose seeking. ZIP is a synthetic compound designed to inhibit the atypical PKC, PKMζ, a protein implicated in learning and memory. However, recent evidence from PKMζ-knock-out (KO) mice suggests that ZIP may function through alternative mechanisms. In support of this, we found that ZIP was able to block cue-induced RI in PKMζ-KO mice. One possible mechanism underlying addictive phenotypes is the ability of cocaine to block further plasticity. We hypothesized that ZIP may be working to reverse this anaplasticity. Although ZIP has no effect on accumbal LTD in slices from naive or yoked saline mice, it is able to restore both NMDA-dependent and mGluR5-dependent LTD in animals after cocaine self-administration and withdrawal. These findings demonstrate that intra-accumbal ZIP persistently reverses cocaine-induced behavioral and synaptic plasticity in male and female rodents.SIGNIFICANCE STATEMENT Zeta-inhibitory peptide (ZIP) has been shown to disrupt memory maintenance for experience-dependent behaviors. We examined the effect of ZIP infused into the nucleus accumbens on the reinstatement (RI) of cocaine seeking. We found that intra-accumbal ZIP blocked RI of cocaine seeking 24 h and 1 week later. This effect was specific to RI of cocaine seeking as ZIP did not disrupt RI of food seeking. In conjunction with these behavioral studies we examined the ability of ZIP to reverse cocaine-induced deficits in LTD. We found that ZIP was able to rescue two forms of LTD in cocaine-experienced mice. These studies demonstrate that ZIP is able to reverse cocaine-induced behavioral and synaptic plasticity in a persistent manner.
Collapse
|
18
|
Spinocerebellar ataxia type 14 caused by a nonsense mutation in the PRKCG gene. Mol Cell Neurosci 2019; 98:46-53. [PMID: 31158466 DOI: 10.1016/j.mcn.2019.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/25/2019] [Accepted: 05/30/2019] [Indexed: 12/15/2022] Open
Abstract
Spinocerebellar ataxia type 14 (SCA14) is an autosomal dominant neurodegenerative disorder characterized by cerebellar ataxia with myoclonus, dystonia, spasticity, and rigidity. Although missense mutations and a deletion mutation have been found in the protein kinase C gamma (PRKCG) gene encoding protein kinase C γ (PKCγ) in SCA14 families, a nonsense mutation has not been reported. The patho-mechanisms underlying SCA14 remain poorly understood. However, gain-of-function mechanisms and loss-of-function mechanisms, but not dominant negative mechanisms, were reported the patho-mechanism of SCA14. We identified the c.226C>T mutation of PRKCG, which caused the p.R76X in PKCγ by whole-exome sequencing in patients presenting cerebellar atrophy with cognitive and hearing impairment. To investigate the patho-mechanism of our case, we studied aggregation formation, cell death, and PKC inhibitory effect by confocal microscopy, western blotting with cleaved caspase 3, and pSer PKC motif antibodies, respectively. PKCγ(R76X)-GFP have aggregations the same as wild-type (WT) PKCγ-GFP. The PKCγ(R76X)-GFP inhibited PKC phosphorylation activity more than GFP alone. It also induced more apoptosis in COS7 and SH-SY5Y cells compared to WT-PKCγ-GFP and GFP. We first reported SCA14 patients with p.R76X in PKCγ who have cerebellar atrophy with cognitive and hearing impairment. Our results suggest that a dominant negative mechanism due to truncated peptides produced by p.R76X may be at least partially responsible for the cerebellar atrophy.
Collapse
|
19
|
Odaira T, Nakagawasai O, Takahashi K, Nemoto W, Sakuma W, Lin JR, Tan-No K. Mechanisms underpinning AMP-activated protein kinase-related effects on behavior and hippocampal neurogenesis in an animal model of depression. Neuropharmacology 2019; 150:121-133. [PMID: 30914305 DOI: 10.1016/j.neuropharm.2019.03.026] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 03/01/2019] [Accepted: 03/19/2019] [Indexed: 01/04/2023]
Abstract
Adenosine monophosphate-activated protein kinase (AMPK) is critical for whole-body energy metabolism regulation. Recent studies have suggested that physical exercise ameliorates depressive-like behaviors via AMPK activation; however, the underlying mechanism is unclear. Here, we examined the effects and underlying mechanisms of AMPK activation on depressive-like behavior in olfactory bulbectomized (OBX) mice. We treated OBX mice with the AMPK activator, 5-aminoimidazole-4-carboxamide-1-β-d-ribonucleotide (AICAR) on the 7th or 14th day after bilateral bulbectomy and evaluated depressive-like behavior using the tail-suspension test (TST) and forced swimming test (FST) on the 21st day. The expression of phosphorylated AMPK, protein kinase C ζ (PKCζ), nuclear factor-kappa B (NF-κB), brain-derived neurotrophic factor (BDNF), and cAMP response element-binding protein (CREB) in the hippocampus was assessed by western blotting. Hippocampal neurogenesis and localization of AMPK and phosphorylated NF-κB were examined by immunohistochemistry. Chronic AICAR treatment suppressed the prolonged immobility of OBX mice in the TST and FST, and increased the levels of phosphorylated AMPK, PKCζ, NF-κB, CREB, and BDNF. Hippocampal neurogenesis in OBX mice was promoted by chronic AICAR treatment. Co-administration of AICAR with the PKCζ inhibitor or the neurotrophic tyrosine kinase receptor type 2 (TrkB) antagonist, ANA-12, inhibited these effects. Phosphorylated AMPK was detected in mature and immature hippocampal neurons and microglia, while phosphorylated NF-κB was detected only in neurons in AICAR-treated OBX mice. These data indicate that AMPK activation produces anti-depressant effects, which are mediated by elevated hippocampal neurogenesis potentially via PKCζ/NF-κB/BDNF/TrkB/CREB signaling in neurons.
Collapse
Affiliation(s)
- Takayo Odaira
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Osamu Nakagawasai
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
| | - Kohei Takahashi
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Wataru Nemoto
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Wakana Sakuma
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Jia-Rong Lin
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Koichi Tan-No
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| |
Collapse
|
20
|
Geribaldi-Doldán N, Gómez-Oliva R, Domínguez-García S, Nunez-Abades P, Castro C. Protein Kinase C: Targets to Regenerate Brain Injuries? Front Cell Dev Biol 2019; 7:39. [PMID: 30949480 PMCID: PMC6435489 DOI: 10.3389/fcell.2019.00039] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/04/2019] [Indexed: 12/28/2022] Open
Abstract
Acute or chronic injury to the central nervous system (CNS), causes neuronal death and irreversible cognitive deficits or sensory-motor alteration. Despite the capacity of the adult CNS to generate new neurons from neural stem cells (NSC), neuronal replacement following an injury is a restricted process, which does not naturally result in functional regeneration. Therefore, potentiating endogenous neurogenesis is one of the strategies that are currently being under study to regenerate damaged brain tissue. The insignificant neurogenesis that occurs in CNS injuries is a consequence of the gliogenic/non-neurogenic environment that inflammatory signaling molecules create within the injured area. The modification of the extracellular signals to generate a neurogenic environment would facilitate neuronal replacement. However, in order to generate this environment, it is necessary to unearth which molecules promote or impair neurogenesis to introduce the first and/or eliminate the latter. Specific isozymes of the protein kinase C (PKC) family differentially contribute to generate a gliogenic or neurogenic environment in injuries by regulating the ADAM17 mediated release of growth factor receptor ligands. Recent reports describe several non-tumorigenic diterpenes isolated from plants of the Euphorbia genus, which specifically modulate the activity of PKC isozymes promoting neurogenesis. Diterpenes with 12-deoxyphorbol or lathyrane skeleton, increase NPC proliferation in neurogenic niches in the adult mouse brain in a PKCβ dependent manner exerting their effects on transit amplifying cells, whereas PKC inhibition in injuries promotes neurogenesis. Thus, compounds that balance PKC activity in injuries might be of use in the development of new drugs and therapeutic strategies to regenerate brain injuries.
Collapse
Affiliation(s)
- Noelia Geribaldi-Doldán
- Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Cádiz, Spain.,Instituto de Investigación e Innovación Biomedica de Cádiz (INIBICA), Cádiz, Spain
| | - Ricardo Gómez-Oliva
- Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Cádiz, Spain.,Instituto de Investigación e Innovación Biomedica de Cádiz (INIBICA), Cádiz, Spain
| | - Samuel Domínguez-García
- Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Cádiz, Spain.,Instituto de Investigación e Innovación Biomedica de Cádiz (INIBICA), Cádiz, Spain
| | - Pedro Nunez-Abades
- Instituto de Investigación e Innovación Biomedica de Cádiz (INIBICA), Cádiz, Spain.,Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain
| | - Carmen Castro
- Área de Fisiología, Facultad de Medicina, Universidad de Cádiz, Cádiz, Spain.,Instituto de Investigación e Innovación Biomedica de Cádiz (INIBICA), Cádiz, Spain
| |
Collapse
|
21
|
aPKC controls endothelial growth by modulating c-Myc via FoxO1 DNA-binding ability. Nat Commun 2018; 9:5357. [PMID: 30559384 PMCID: PMC6297234 DOI: 10.1038/s41467-018-07739-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 11/15/2018] [Indexed: 02/07/2023] Open
Abstract
Strict regulation of proliferation is vital for development, whereas unregulated cell proliferation is a fundamental characteristic of cancer. The polarity protein atypical protein kinase C lambda/iota (aPKCλ) is associated with cell proliferation through unknown mechanisms. In endothelial cells, suppression of aPKCλ impairs proliferation despite hyperactivated mitogenic signaling. Here we show that aPKCλ phosphorylates the DNA binding domain of forkhead box O1 (FoxO1) transcription factor, a gatekeeper of endothelial growth. Although mitogenic signaling excludes FoxO1 from the nucleus, consequently increasing c-Myc abundance and proliferation, aPKCλ controls c-Myc expression via FoxO1/miR-34c signaling without affecting its localization. We find this pathway is strongly activated in the malignant vascular sarcoma, angiosarcoma, and aPKC inhibition reduces c-Myc expression and proliferation of angiosarcoma cells. Moreover, FoxO1 phosphorylation at Ser218 and aPKC expression correlates with poor patient prognosis. Our findings may provide a potential therapeutic strategy for treatment of malignant cancers, like angiosarcoma. The cell polarity regulator aPKC is associated with cell proliferation but the precise mechanism are unknown. Here, the authors find that aPKC lambda phosphorylates the FoxO1 transcription factor, a gatekeeper of endothelial growth, during both angiogenesis and angiosarcomas.
Collapse
|
22
|
Liu Z, Khalil RA. Evolving mechanisms of vascular smooth muscle contraction highlight key targets in vascular disease. Biochem Pharmacol 2018; 153:91-122. [PMID: 29452094 PMCID: PMC5959760 DOI: 10.1016/j.bcp.2018.02.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 02/12/2018] [Indexed: 12/11/2022]
Abstract
Vascular smooth muscle (VSM) plays an important role in the regulation of vascular function. Identifying the mechanisms of VSM contraction has been a major research goal in order to determine the causes of vascular dysfunction and exaggerated vasoconstriction in vascular disease. Major discoveries over several decades have helped to better understand the mechanisms of VSM contraction. Ca2+ has been established as a major regulator of VSM contraction, and its sources, cytosolic levels, homeostatic mechanisms and subcellular distribution have been defined. Biochemical studies have also suggested that stimulation of Gq protein-coupled membrane receptors activates phospholipase C and promotes the hydrolysis of membrane phospholipids into inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). IP3 stimulates initial Ca2+ release from the sarcoplasmic reticulum, and is buttressed by Ca2+ influx through voltage-dependent, receptor-operated, transient receptor potential and store-operated channels. In order to prevent large increases in cytosolic Ca2+ concentration ([Ca2+]c), Ca2+ removal mechanisms promote Ca2+ extrusion via the plasmalemmal Ca2+ pump and Na+/Ca2+ exchanger, and Ca2+ uptake by the sarcoplasmic reticulum and mitochondria, and the coordinated activities of these Ca2+ handling mechanisms help to create subplasmalemmal Ca2+ domains. Threshold increases in [Ca2+]c form a Ca2+-calmodulin complex, which activates myosin light chain (MLC) kinase, and causes MLC phosphorylation, actin-myosin interaction, and VSM contraction. Dissociations in the relationships between [Ca2+]c, MLC phosphorylation, and force have suggested additional Ca2+ sensitization mechanisms. DAG activates protein kinase C (PKC) isoforms, which directly or indirectly via mitogen-activated protein kinase phosphorylate the actin-binding proteins calponin and caldesmon and thereby enhance the myofilaments force sensitivity to Ca2+. PKC-mediated phosphorylation of PKC-potentiated phosphatase inhibitor protein-17 (CPI-17), and RhoA-mediated activation of Rho-kinase (ROCK) inhibit MLC phosphatase and in turn increase MLC phosphorylation and VSM contraction. Abnormalities in the Ca2+ handling mechanisms and PKC and ROCK activity have been associated with vascular dysfunction in multiple vascular disorders. Modulators of [Ca2+]c, PKC and ROCK activity could be useful in mitigating the increased vasoconstriction associated with vascular disease.
Collapse
Affiliation(s)
- Zhongwei Liu
- Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA 02115, USA
| | - Raouf A Khalil
- Vascular Surgery Research Laboratories, Division of Vascular and Endovascular Surgery, Brigham and Women's Hospital, and Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
23
|
Drummond ML, Li M, Tarapore E, Nguyen TTL, Barouni BJ, Cruz S, Tan KC, Oro AE, Atwood SX. Actin polymerization controls cilia-mediated signaling. J Cell Biol 2018; 217:3255-3266. [PMID: 29945904 PMCID: PMC6122990 DOI: 10.1083/jcb.201703196] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 03/29/2018] [Accepted: 05/31/2018] [Indexed: 01/20/2023] Open
Abstract
Actin polymerization is important to generate primary cilia. Drummond et al. show that upstream actin regulators are necessary for this process by controlling aPKC and Src kinase activity to promote Hedgehog signaling and restrict primary cilia. Primary cilia are polarized organelles that allow detection of extracellular signals such as Hedgehog (Hh). How the cytoskeleton supporting the cilium generates and maintains a structure that finely tunes cellular response remains unclear. Here, we find that regulation of actin polymerization controls primary cilia and Hh signaling. Disrupting actin polymerization, or knockdown of N-WASp/Arp3, increases ciliation frequency, axoneme length, and Hh signaling. Cdc42, a potent actin regulator, recruits both atypical protein pinase C iota/lambda (aPKC) and Missing-in-Metastasis (MIM) to the basal body to maintain actin polymerization and restrict axoneme length. Transcriptome analysis implicates the Src pathway as a major aPKC effector. aPKC promotes whereas MIM antagonizes Src activity to maintain proper levels of primary cilia, actin polymerization, and Hh signaling. Hh pathway activation requires Smoothened-, Gli-, and Gli1-specific activation by aPKC. Surprisingly, longer axonemes can amplify Hh signaling, except when aPKC is disrupted, reinforcing the importance of the Cdc42–aPKC–Gli axis in actin-dependent regulation of primary cilia signaling.
Collapse
Affiliation(s)
- Michael L Drummond
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Mischa Li
- Department of Dermatology, Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA
| | - Eric Tarapore
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Tuyen T L Nguyen
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Baina J Barouni
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Shaun Cruz
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Kevin C Tan
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA
| | - Anthony E Oro
- Department of Dermatology, Program in Epithelial Biology, Stanford University School of Medicine, Stanford, CA
| | - Scott X Atwood
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA .,Department of Dermatology, University of California, Irvine, Irvine, CA.,Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA
| |
Collapse
|
24
|
Dorfman MD, Krull JE, Scarlett JM, Guyenet SJ, Sajan MP, Damian V, Nguyen HT, Leitges M, Morton GJ, Farese RV, Schwartz MW, Thaler JP. Deletion of Protein Kinase C λ in POMC Neurons Predisposes to Diet-Induced Obesity. Diabetes 2017; 66:920-934. [PMID: 28073831 PMCID: PMC5360303 DOI: 10.2337/db16-0482] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 01/02/2017] [Indexed: 12/16/2022]
Abstract
Effectors of the phosphoinositide 3-kinase (PI3K) signal transduction pathway contribute to the hypothalamic regulation of energy and glucose homeostasis in divergent ways. Here we show that central nervous system (CNS) action of the PI3K signaling intermediate atypical protein kinase C (aPKC) constrains food intake, weight gain, and glucose intolerance in both rats and mice. Pharmacological inhibition of CNS aPKC activity acutely increases food intake and worsens glucose tolerance in chow-fed rodents and causes excess weight gain during high-fat diet (HFD) feeding. Similarly, selective deletion of the aPKC isoform Pkc-λ in proopiomelanocortin (POMC) neurons disrupts leptin action, reduces melanocortin content in the paraventricular nucleus, and markedly increases susceptibility to obesity, glucose intolerance, and insulin resistance specifically in HFD-fed male mice. These data implicate aPKC as a novel regulator of energy and glucose homeostasis downstream of the leptin-PI3K pathway in POMC neurons.
Collapse
Affiliation(s)
- Mauricio D Dorfman
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Jordan E Krull
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Jarrad M Scarlett
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Stephan J Guyenet
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Mini P Sajan
- Department of Internal Medicine, University of South Florida College of Medicine, Tampa, FL
- Research & Internal Medicine Services, James A. Haley VA Medical Center, Tampa, FL
| | - Vincent Damian
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Hong T Nguyen
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Michael Leitges
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | - Gregory J Morton
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Robert V Farese
- Department of Internal Medicine, University of South Florida College of Medicine, Tampa, FL
- Research & Internal Medicine Services, James A. Haley VA Medical Center, Tampa, FL
| | - Michael W Schwartz
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| | - Joshua P Thaler
- UW Diabetes Institute and Department of Medicine, University of Washington, Seattle, WA
| |
Collapse
|
25
|
Luo J, Busillo JM, Stumm R, Benovic JL. G Protein-Coupled Receptor Kinase 3 and Protein Kinase C Phosphorylate the Distal C-Terminal Tail of the Chemokine Receptor CXCR4 and Mediate Recruitment of β-Arrestin. Mol Pharmacol 2017; 91:554-566. [PMID: 28331048 DOI: 10.1124/mol.116.106468] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 03/17/2017] [Indexed: 01/27/2023] Open
Abstract
Phosphorylation of G protein-coupled receptors (GPCRs) is a key event for cell signaling and regulation of receptor function. Previously, using tandem mass spectrometry, we identified two phosphorylation sites at the distal C-terminal tail of the chemokine receptor CXCR4, but were unable to determine which specific residues were phosphorylated. Here, we demonstrate that serines (Ser) 346 and/or 347 (Ser-346/7) of CXCR4 are phosphorylated upon stimulation with the agonist CXCL12 as well as a CXCR4 pepducin, ATI-2341. ATI-2341, a Gαiβγ heterotrimer-biased CXCR4 agonist, induced more robust phosphorylation of Ser-346/7 compared with CXCL12. Knockdown of G protein-coupled receptor kinase (GRK) 2, GRK3, or GRK6 reduced CXCL12-induced phosphorylation of Ser-346/7 with GRK3 knockdown having the strongest effect, while inhibition of the conventional protein kinase C (PKC) isoforms, particularly PKCα, reduced phosphorylation of Ser-346/7 induced by either CXCL12 or ATI-2341. The loss of GRK3- or PKC-mediated phosphorylation of Ser-346/7 impaired the recruitment of β-arrestin to CXCR4. We also found that a pseudo-substrate peptide inhibitor for PKCζ effectively inhibited CXCR4 phosphorylation and signaling, most likely by functioning as a nonspecific CXCR4 antagonist. Together, these studies demonstrate the role Ser-346/7 plays in arrestin recruitment and initiation of receptor desensitization and provide insight into the dysregulation of CXCR4 observed in patients with various forms of WHIM syndrome.
Collapse
Affiliation(s)
- Jiansong Luo
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania (J.L., J.M.B., J.L.B.); and Institute of Pharmacology and Toxicology, University Hospital, Friedrich-Schiller University, Jena, Germany (R.S.)
| | - John M Busillo
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania (J.L., J.M.B., J.L.B.); and Institute of Pharmacology and Toxicology, University Hospital, Friedrich-Schiller University, Jena, Germany (R.S.)
| | - Ralf Stumm
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania (J.L., J.M.B., J.L.B.); and Institute of Pharmacology and Toxicology, University Hospital, Friedrich-Schiller University, Jena, Germany (R.S.)
| | - Jeffrey L Benovic
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania (J.L., J.M.B., J.L.B.); and Institute of Pharmacology and Toxicology, University Hospital, Friedrich-Schiller University, Jena, Germany (R.S.)
| |
Collapse
|
26
|
Ringvold HC, Khalil RA. Protein Kinase C as Regulator of Vascular Smooth Muscle Function and Potential Target in Vascular Disorders. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 78:203-301. [PMID: 28212798 PMCID: PMC5319769 DOI: 10.1016/bs.apha.2016.06.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Vascular smooth muscle (VSM) plays an important role in maintaining vascular tone. In addition to Ca2+-dependent myosin light chain (MLC) phosphorylation, protein kinase C (PKC) is a major regulator of VSM function. PKC is a family of conventional Ca2+-dependent α, β, and γ, novel Ca2+-independent δ, ɛ, θ, and η, and atypical ξ, and ι/λ isoforms. Inactive PKC is mainly cytosolic, and upon activation it undergoes phosphorylation, maturation, and translocation to the surface membrane, the nucleus, endoplasmic reticulum, and other cell organelles; a process facilitated by scaffold proteins such as RACKs. Activated PKC phosphorylates different substrates including ion channels, pumps, and nuclear proteins. PKC also phosphorylates CPI-17 leading to inhibition of MLC phosphatase, increased MLC phosphorylation, and enhanced VSM contraction. PKC could also initiate a cascade of protein kinases leading to phosphorylation of the actin-binding proteins calponin and caldesmon, increased actin-myosin interaction, and VSM contraction. Increased PKC activity has been associated with vascular disorders including ischemia-reperfusion injury, coronary artery disease, hypertension, and diabetic vasculopathy. PKC inhibitors could test the role of PKC in different systems and could reduce PKC hyperactivity in vascular disorders. First-generation PKC inhibitors such as staurosporine and chelerythrine are not very specific. Isoform-specific PKC inhibitors such as ruboxistaurin have been tested in clinical trials. Target delivery of PKC pseudosubstrate inhibitory peptides and PKC siRNA may be useful in localized vascular disease. Further studies of PKC and its role in VSM should help design isoform-specific PKC modulators that are experimentally potent and clinically safe to target PKC in vascular disease.
Collapse
Affiliation(s)
- H C Ringvold
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - R A Khalil
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States.
| |
Collapse
|
27
|
Barcomb K, Hell JW, Benke TA, Bayer KU. The CaMKII/GluN2B Protein Interaction Maintains Synaptic Strength. J Biol Chem 2016; 291:16082-9. [PMID: 27246855 DOI: 10.1074/jbc.m116.734822] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Indexed: 11/06/2022] Open
Abstract
Learning, memory, and cognition are thought to require normal long-term potentiation (LTP) of synaptic strength, which in turn requires binding of the Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) to the NMDA-type glutamate receptor (NMDAR) subunit GluN2B. For LTP induction, many additional required players are known. Here we tested the hypothesis that CaMKII/GluN2B binding also mediates the more elusive maintenance of synaptic strength. Intriguingly, the CaMKII inhibitor tatCN21 reduces synaptic strength only at high concentrations necessary for CaMKII/NMDAR disruption (20 μm) but not at lower concentrations sufficient for kinase inhibition (5 μm). However, increased concentration also causes unrelated effects. Thus, to distinguish between correlation and causality, we used a pharmacogenetic approach. In a mouse with a mutant NMDAR GluN2B subunit that is CaMKII binding-incompetent, any tatCN21 effects that are specific to the CaMKII/GluN2B interaction should be abolished, and any remaining tatCN21 effects have to be nonspecific (i.e. mediated by other targets). The results showed that the persistent reduction of synaptic strength by transient application of 20 μm tatCN21 had a nonspecific presynaptic component (on fiber volley amplitude) that was unrelated to the CaMKII/GluN2B interaction or CaMKII activity. However, the remaining component of the persistent tatCN21 effect was almost completely abolished in the GluN2B mutant mouse. These results highlight the requirement for stringent pharmacogenetic approaches to separate specific on-target effects from nonspecific off-target effects. Importantly, they also demonstrate that the CaMKII/GluN2B interaction is required not only for normal LTP induction but also for the maintenance of synaptic strength.
Collapse
Affiliation(s)
| | - Johannes W Hell
- the Department of Pharmacology, School of Medicine, University of California, Davis, California 95616
| | - Tim A Benke
- Pediatrics, Section of Neurology, School of Medicine, University of Colorado Denver, Aurora, Colorado 80045 and
| | | |
Collapse
|
28
|
Chen C, Meng SQ, Xue YX, Han Y, Sun CY, Deng JH, Chen N, Bao YP, Zhang FL, Cao LL, Zhu WG, Shi J, Song WH, Lu L. Epigenetic modification of PKMζ rescues aging-related cognitive impairment. Sci Rep 2016; 6:22096. [PMID: 26926225 PMCID: PMC4772003 DOI: 10.1038/srep22096] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/05/2016] [Indexed: 12/18/2022] Open
Abstract
Cognition is impacted by aging. However, the mechanisms that underlie aging-associated cognitive impairment are unclear. Here we showed that cognitive decline in aged rats was associated with changes in DNA methylation of protein kinase Mζ (PKMζ) in the prelimbic cortex (PrL). PKMζ is a crucial molecule involved in the maintenance of long-term memory. Using different behavioral models, we confirmed that aged rats exhibited cognitive impairment in memory retention test 24 h after training, and overexpression of PKMζ in the PrL rescued cognitive impairment in aged rats. After fear conditioning, the protein levels of PKMζ and the membrane expression of GluR2 increased in the PrL in young and adult rats but not in aged rats, and the levels of methylated PKMζ DNA in the PrL decreased in all age groups, whereas the levels of unmethylated PKMζ DNA increased only in young and adult rats. We also found that environmentally enriched housing reversed the hypermethylation of PKMζ and restored cognitive performance in aged rats. Inactivation of PKMζ prevented the potentiating effects of environmental enrichment on memory retention in aged rats. These results indicated that PKMζ might be a potential target for the treatment of aging-related cognitive impairment, suggesting a potential therapeutic avenue.
Collapse
Affiliation(s)
- Chen Chen
- Institute of Mental Health, Peking University Sixth Hospital, and Key Laboratory of Mental Health, Beijing 100191, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Shi-Qiu Meng
- Institute of Mental Health, Peking University Sixth Hospital, and Key Laboratory of Mental Health, Beijing 100191, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Yan-Xue Xue
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Ying Han
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Cheng-Yu Sun
- Institute of Mental Health, Peking University Sixth Hospital, and Key Laboratory of Mental Health, Beijing 100191, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Jia-Hui Deng
- Institute of Mental Health, Peking University Sixth Hospital, and Key Laboratory of Mental Health, Beijing 100191, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Na Chen
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Yan-Ping Bao
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Fei-Long Zhang
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Lin-Lin Cao
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Wei-Guo Zhu
- Department of Biochemistry and Molecular Biology, Peking University Health Science Center, Beijing 100191, China
| | - Jie Shi
- National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China
| | - Wei-Hong Song
- Brain Research Centre, Departments of Medicine and Psychiatry, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Lin Lu
- Institute of Mental Health, Peking University Sixth Hospital, and Key Laboratory of Mental Health, Beijing 100191, China.,National Institute on Drug Dependence and Beijing Key Laboratory of Drug Dependence Research, Peking University, Beijing 100191, China.,Peking-Tsinghua Center for Life Sciences and PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing 100871, China
| |
Collapse
|