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Fahmideh F, Marchesi N, Campagnoli LIM, Landini L, Caramella C, Barbieri A, Govoni S, Pascale A. Effect of troxerutin in counteracting hyperglycemia-induced VEGF upregulation in endothelial cells: a new option to target early stages of diabetic retinopathy? Front Pharmacol 2022; 13:951833. [PMID: 36046820 PMCID: PMC9420903 DOI: 10.3389/fphar.2022.951833] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/25/2022] [Indexed: 12/21/2022] Open
Abstract
Diabetic retinopathy (DR), one of the most common complications of diabetes mellitus, is characterized by degeneration of retinal neurons and neoangiogenesis. Until today, the pharmacological approaches for DR are limited and focused on counteracting the end-stage of this neurodegenerative disease, therefore efforts should be carried out to discover novel pharmacological targets useful to prevent DR development. Hyperglycemia is a major risk factor for endothelial dysfunction and vascular complication, which subsequently may trigger neurodegeneration. We previously demonstrated that, in the rat retina, hyperglycemia activates a new molecular cascade implicating, up-stream, protein kinase C βII (PKC βII), which in turn leads to a higher expression of vascular endothelial growth factor (VEGF), via the mRNA-binding Hu-antigen R (HuR) protein. VEGF is a pivotal mediator of neovascularization and a well-known vasopermeability factor. Blocking the increase of VEGF via modulation of this cascade can thus represent a new pharmacological option to prevent DR progression. To this aim, proper in vitro models are crucial for drug discovery, as they allow to better identify promising effective molecules. Considering that endothelial cells are key elements in DR and that hyperglycemia triggers the PKCβII/HuR/VEGF pathway, we set up two distinct in vitro models applying two different stimuli. Namely, human umbilical vein endothelial cells were exposed to phorbol 12-myristate 13-acetate, which mimics diacylglycerol whose synthesis is triggered by diabetic hyperglycemia, while human retinal endothelial cells were treated with high glucose for different times. After selecting the optimal experimental conditions able to determine an increased VEGF production, in search of molecules useful to prevent DR development, we investigated the capability of troxerutin, an antioxidant flavonoid, to counteract not only the rise of VEGF but also the activation of the PKCβII/HuR cascade in both in vitro models. The results show the capability of troxerutin to hinder the hyperglycemia-induced increase in VEGF in both models through PKCβII/HuR pathway modulation. Further, these data confirm the key engagement of this cascade as an early event triggered by hyperglycemia to promote VEGF expression. Finally, the present findings also suggest the potential use of troxerutin as a preventive treatment during the early phases of DR.
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Affiliation(s)
- F. Fahmideh
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - N. Marchesi
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
- *Correspondence: N. Marchesi, ; A. Pascale,
| | - L. I. M. Campagnoli
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - L. Landini
- Bausch & Lomb—Iom S.p.A, Vimodrone (Milan), Italy
| | - C. Caramella
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - A. Barbieri
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - S. Govoni
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - A. Pascale
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
- *Correspondence: N. Marchesi, ; A. Pascale,
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Chaib M, Sipe LM, Yarbro JR, Bohm MS, Counts BR, Tanveer U, Pingili AK, Daria D, Marion TN, Carson JA, Thomas PG, Makowski L. PKC agonism restricts innate immune suppression, promotes antigen cross-presentation and synergizes with agonistic CD40 antibody therapy to activate CD8 + T cells in breast cancer. Cancer Lett 2022; 531:98-108. [PMID: 35074498 PMCID: PMC9867936 DOI: 10.1016/j.canlet.2022.01.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/01/2022] [Accepted: 01/13/2022] [Indexed: 01/26/2023]
Abstract
Myeloid-derived suppressor cells (MDSCs) are an immature innate cell population that expands in pathological conditions such as cancer and suppresses T cells via production of immunosuppressive factors. Conversely, efficient cytotoxic T cell priming is dependent on the ability of antigen-presenting cells (APCs) to cross-present tumor antigens to CD8+ T cells, a process that requires a specific subtype of dendritic cells (DCs) called conventional DC1 (cDC1) which are often dysfunctional in cancer. One way to activate cDC1 is ligation of CD40 which is abundantly expressed by myeloid cells and its agonism leads to myeloid cell activation. Thus, targeting MDSCs while simultaneously expanding cross-presenting DCs represents a promising strategy that, when combined with agonistic CD40, may result in long-lasting protective immunity. In this study, we investigated the effect of PKC agonists PEP005 and prostratin on MDSC expansion, differentiation, and recruitment to the tumor microenvironment. Our findings demonstrate that PKC agonists decreased MDSC expansion from hematopoietic progenitors and induced M-MDSC differentiation to an APC-like phenotype that expresses cDC1-related markers via activation of the p38 mitogen-activated protein kinase (MAPK) pathway. Simultaneously, PKC agonists favored cDC1 expansion at the expense of cDC2 and plasmacytoid DCs (pDC). Functionally, PKC agonists blunted MDSC suppressive activity and enhanced MDSC cross-priming capacity both in vitro and in vivo. Finally, combination of PKC agonism with agonistic CD40 mAb resulted in a marked reduction in tumor growth with a significant increase in intratumoral activated CD8+ T cells and tissue-resident memory CD8+ T cells in a syngeneic breast cancer mouse model. In sum, this work proposes a novel promising strategy to simultaneously target MDSCs and promote APC function that may have highly impactful clinical relevance in cancer patients.
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Affiliation(s)
- Mehdi Chaib
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Laura M. Sipe
- Department of Medicine, Division of Hematology and Oncology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Johnathan R. Yarbro
- Department of Medicine, Division of Hematology and Oncology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Margaret S. Bohm
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Brittany R. Counts
- Division of Regenerative and Rehabilitation Sciences, College of Health Professions, UTHSC Memphis, USA
| | - Ubaid Tanveer
- Department of Medicine, Division of Hematology and Oncology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Ajeeth K. Pingili
- Department of Medicine, Division of Hematology and Oncology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Deidre Daria
- Office of Vice Chancellor for Research, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Tony N. Marion
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA,Office of Vice Chancellor for Research, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - James A. Carson
- Division of Regenerative and Rehabilitation Sciences, College of Health Professions, UTHSC Memphis, USA,UTHSC Center for Cancer Research, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Paul G. Thomas
- Department of Microbiology, Immunology, and Biochemistry, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA,Department of Immunology, St. Jude Children’s Research Hospital, Memphis, TN, 38105, USA,UTHSC Center for Cancer Research, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Liza Makowski
- Department of Pharmaceutical Sciences, College of Pharmacy, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA,Department of Medicine, Division of Hematology and Oncology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA,Department of Microbiology, Immunology, and Biochemistry, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA,UTHSC Center for Cancer Research, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, 38163, USA,Corresponding author. Cancer Research Building Room 322, UTHSC Center for Cancer Research, University of Tennessee Health Science Center, 19 South Manassas, Memphis, TN, 38163, USA. (L. Makowski)
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3
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Bucolo C, Barbieri A, Viganò I, Marchesi N, Bandello F, Drago F, Govoni S, Zerbini G, Pascale A. Short-and Long-Term Expression of Vegf: A Temporal Regulation of a Key Factor in Diabetic Retinopathy. Front Pharmacol 2021; 12:707909. [PMID: 34489701 PMCID: PMC8418071 DOI: 10.3389/fphar.2021.707909] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
To investigate the role of vascular endothelial growth factor (VEGF) at different phases of diabetic retinopathy (DR), we assessed the retinal protein expression of VEGF-A164 (corresponding to the VEGF165 isoform present in humans, which is the predominant member implicated in vascular hyperpermeability and proliferation), HIF-1α and PKCβ/HuR pathway in Ins2Akita (diabetic) mice at different ages. We used C57BL6J mice (WT) at different ages as control. Retina status, in terms of tissue morphology and neovascularization, was monitored in vivo at different time points by optical coherence tomography (OCT) and fluorescein angiography (FA), respectively. The results showed that VEGF-A164 protein expression increased along time to become significantly elevated (p < 0.05) at 9 and 46 weeks of age compared to WT mice. The HIF-1α protein level was significantly (p < 0.05) increased at 9 weeks of age, while PKCβII and HuR protein levels were increased at 46 weeks of age compared to WT mice. The thickness of retinal nerve fiber layer as measured by OCT was decreased in Ins2Akita mice at 9 and 46 weeks of age, while no difference in the retinal vasculature were observed by FA. The present findings show that the retina of the diabetic Ins2Akita mice, as expected for mice, does not develop proliferative retinopathy even after 46 weeks. However, diabetic Ins2Akita mice recapitulate the same evolution of patients with DR in terms of both retinal neurodegeneration and pro-angiogenic shift, this latter indicated by the progressive protein expression of the pro-angiogenic isoform VEGF-A164, which can be sustained by the PKCβII/HuR pathway acting at post-transcriptional level. In agreement with this last concept, this rise in VEGF-A164 protein is not paralleled by an increment of the corresponding transcript. Nevertheless, the observed increase in HIF-1α at 9 weeks indicates that this transcription factor may favor, in the early phase of the disease, the transcription of other isoforms, possibly neuroprotective, in the attempt to counteract the neurodegenerative effects of VEGF-A164. The time-dependent VEGF-A164 expression in the retina of diabetic Ins2Akita mice suggests that pharmacological intervention in DR might be chosen, among other reasons, on the basis of the specific stages of the pathology in order to pursue the best clinical outcome.
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Affiliation(s)
- Claudio Bucolo
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Annalisa Barbieri
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Ilaria Viganò
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Nicoletta Marchesi
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Francesco Bandello
- Department of Ophthalmology, IRCCS Ospedale San Raffaele, Vita-Salute University, Milan, Italy
| | - Filippo Drago
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy.,Center for Research in Ocular Pharmacology-CERFO, University of Catania, Catania, Italy
| | - Stefano Govoni
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
| | - Gianpaolo Zerbini
- Complications of Diabetes Unit, Diabetes Research Institute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Alessia Pascale
- Department of Drug Sciences, Pharmacology Section, University of Pavia, Pavia, Italy
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Wang Y, Gao N, Feng Y, Cai M, Li Y, Xu X, Zhang H, Yao D. Protein kinase C theta (Prkcq) affects nerve degeneration and regeneration through the c-fos and c-jun pathways in injured rat sciatic nerves. Exp Neurol 2021; 346:113843. [PMID: 34418453 DOI: 10.1016/j.expneurol.2021.113843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 07/23/2021] [Accepted: 08/15/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Previous finding using DNA microarray and bioinformatics analysis, we have reported some key factors which regulated gene expression and signaling pathways in injured sciatic nerve during Wallerian Degeneration (WD). This research is focused on protein kinase C theta (Prkcq) participates in the regulation of the WD process. METHODS In this study, we explored the molecular mechanism by which Prkcq in Schwann cells (SCs) affects nerve degeneration and regeneration in vivo and in vitro after rat sciatic nerve injury. RESULTS Study of the cross-sectional model showed that Prkcq expression decreased significantly during sciatic nerve repair. Functional analysis showed that upregulation and downregulation of Prkcq could affect the proliferation, migration and apoptosis of Schwann cells and lead to the expression of related factors through the activation of the β-catenin, c-fos, and p-c-jun/c-jun pathways. CONCLUSION The study provides insights into the role of Prkcq in early WD during peripheral nerve degeneration and/or regeneration.
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Affiliation(s)
- Yi Wang
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Nannan Gao
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Yumei Feng
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Min Cai
- Medical School of Nantong University, Nantong, Jiangsu 226001, PR China.
| | - Yuting Li
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Xi Xu
- Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, PR China
| | - Huanhuan Zhang
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China
| | - Dengbing Yao
- School of Life Sciences, Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226019, PR China.
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5
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Schmitz-Peiffer C. Deconstructing the Role of PKC Epsilon in Glucose Homeostasis. Trends Endocrinol Metab 2020; 31:344-356. [PMID: 32305097 DOI: 10.1016/j.tem.2020.01.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/22/2020] [Accepted: 01/24/2020] [Indexed: 02/06/2023]
Abstract
The failure of insulin to suppress glucose production by the liver is a key aspect of the insulin resistance seen in type 2 diabetes. Lipid-activated protein kinase C epsilon has long been identified as an important mediator of diet-induced glucose intolerance and hepatic insulin resistance and the current view emphasizes a mechanism involving phosphorylation of the insulin receptor by the kinase to inhibit downstream insulin action. However, the significance of this direct effect in the liver has now been challenged by tissue-specific deletion of PKCε, which demonstrated a more prominent role for the kinase in adipose tissue to promote glucose intolerance. New insights regarding the role of PKCε therefore contribute to the understanding of indirect effects on hepatic glucose metabolism.
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Affiliation(s)
- Carsten Schmitz-Peiffer
- Garvan Institute of Medical Research, Darlinghurst Sydney, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia.
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6
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Lipopeptide PAM3CYS4 Synergizes N-Formyl-Met-Leu-Phe (fMLP)-Induced Calcium Transients in Mouse Neutrophils. Shock 2019; 50:493-499. [PMID: 29176405 DOI: 10.1097/shk.0000000000001062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
N-Formyl-Met-Leu-Phe (fMLP), a mimic of N-formyl oligopeptides that are released from bacteria, is a potent leukocyte chemotactic factor. It induces intracellular calcium ([Ca]i) transient that is important for various neutrophil biological functions, e.g., adhesion, ROS, and cytokine productions. Toll-like receptors (TLRs), an essential part of host innate immunity, regulate neutrophil activities, but their role in [Ca]i signaling is less clear. In the present study, we examined the effect of several TLR ligands, including Pam3Cys4 (TLR1/2), lipopolysaccharide (LPS, TLR4), and lipoteichoic acid (LTA, TLR2/6), on calcium signaling and on the fMLP-induced [Ca]i transients in mouse neutrophils loaded with Fura-2/AM. We found that unlike fMLP, the three TLR ligands tested did not elicit any detectable Ca flux. However, Pam3Cys4, but not LPS or LTA, markedly synergized the fMLP-induced [Ca]i transients, and had no effect on the host component keratinocyte-derived cytokine (KC)- or C5a-induced calcium flux. The effect of Pam3Cys4 on the fMLP-induced [Ca]i transients is by enhancing extracellular Ca influx, not intracellular Ca release. Surprisingly, deletion of TLR2 or MyD88 in neutrophils had no impact on the Pam3Cys4's effect, suggesting a TLR2-MyD88-independent mechanism. Finally, using the pan PKC activator and inhibitor, we demonstrated that PKC negatively regulated fMLP-induced [Ca]i transients and that inhibition of PKC did not prohibit Pam3Cys4's synergistic effect on the fMLP-induced calcium influx. In conclusion, the present study identified a novel synergistic effect of Pam3Cys4 on fMLP-induced [Ca]i transients, a process important for many neutrophil biological functions.
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7
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Kouhpeikar H, Butler AE, Bamian F, Barreto GE, Majeed M, Sahebkar A. Curcumin as a therapeutic agent in leukemia. J Cell Physiol 2019; 234:12404-12414. [PMID: 30609023 DOI: 10.1002/jcp.28072] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 12/18/2018] [Indexed: 12/28/2022]
Abstract
Leukemia comprises a group of hematological malignancies responsible for 8% of all cancers and is the most common cancer in children. Despite significant improvements in leukemia treatment, the efficacy of conventional chemotherapeutic agents is low and the disease carries a poor prognosis with frequent relapses and high mortality. Curcumin is a yellow polyphenol compound with diverse pharmacological actions including anticancer, antioxidant, antidiabetic, anti-inflammatory, immunomodulatory, hepatoprotective, lipid-regulating, antidepressant, and antiarthritic. Many cellular and experimental studies have reported the benefits of curcumin in treating leukemia. Curcumin's anticancer effects are exerted via various mechanisms. Here, we review the effects of curcumin on various types of leukemia whilst considering its mechanisms of action.
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Affiliation(s)
- Hamideh Kouhpeikar
- Department of Hematology and Blood Bank, Cancer Molecular Pathology Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Iran
| | - Alexandra E Butler
- Diabetes Research Center, Qatar Biomedical Research Institute, Doha, Qatar
| | - Faeze Bamian
- Department of Hematology and Blood Bank, Cancer Molecular Pathology Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Iran
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | | | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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8
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Novel Small-Molecule Inhibitors of Protein Kinase C Epsilon Reduce Ethanol Consumption in Mice. Biol Psychiatry 2018; 84:193-201. [PMID: 29198469 PMCID: PMC5984071 DOI: 10.1016/j.biopsych.2017.10.017] [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] [Received: 12/01/2016] [Revised: 09/22/2017] [Accepted: 10/16/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Despite the high cost and widespread prevalence of alcohol use disorders, treatment options are limited, underscoring the need for new, effective medications. Previous results using protein kinase C epsilon (PKCε) knockout mice, RNA interference against PKCε, and peptide inhibitors of PKCε predict that small-molecule inhibitors of PKCε should reduce alcohol consumption in humans. METHODS We designed a new class of PKCε inhibitors based on the Rho-associated protein kinase (ROCK) inhibitor Y-27632. In vitro kinase and binding assays were used to identify the most potent compounds. Their effects on ethanol-stimulated synaptic transmission; ethanol, sucrose, and quinine consumption; ethanol-induced loss of righting; and ethanol clearance were studied in mice. RESULTS We identified two compounds that inhibited PKCε with Ki <20 nM, showed selectivity for PKCε over other kinases, crossed the blood-brain barrier, achieved effective concentrations in mouse brain, prevented ethanol-stimulated gamma-aminobutyric acid release in the central amygdala, and reduced ethanol consumption when administered intraperitoneally at 40 mg/kg in wild-type but not in Prkce-/- mice. One compound also reduced sucrose and saccharin consumption, while the other was selective for ethanol. Both transiently impaired locomotion through an off-target effect that did not interfere with their ability to reduce ethanol intake. One compound prolonged recovery from ethanol-induced loss of righting but this was also due to an off-target effect since it was present in Prkce-/- mice. Neither altered ethanol clearance. CONCLUSIONS These results identify lead compounds for development of PKCε inhibitors that reduce alcohol consumption.
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9
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Protein kinase C mechanisms that contribute to cardiac remodelling. Clin Sci (Lond) 2017; 130:1499-510. [PMID: 27433023 DOI: 10.1042/cs20160036] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/18/2016] [Indexed: 12/12/2022]
Abstract
Protein phosphorylation is a highly-regulated and reversible process that is precisely controlled by the actions of protein kinases and protein phosphatases. Factors that tip the balance of protein phosphorylation lead to changes in a wide range of cellular responses, including cell proliferation, differentiation and survival. The protein kinase C (PKC) family of serine/threonine kinases sits at nodal points in many signal transduction pathways; PKC enzymes have been the focus of considerable attention since they contribute to both normal physiological responses as well as maladaptive pathological responses that drive a wide range of clinical disorders. This review provides a background on the mechanisms that regulate individual PKC isoenzymes followed by a discussion of recent insights into their role in the pathogenesis of diseases such as cancer. We then provide an overview on the role of individual PKC isoenzymes in the regulation of cardiac contractility and pathophysiological growth responses, with a focus on the PKC-dependent mechanisms that regulate pump function and/or contribute to the pathogenesis of heart failure.
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10
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PKC in Regenerative Therapy: New Insights for Old Targets. Pharmaceuticals (Basel) 2017; 10:ph10020046. [PMID: 28524095 PMCID: PMC5490403 DOI: 10.3390/ph10020046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/12/2017] [Accepted: 05/16/2017] [Indexed: 01/22/2023] Open
Abstract
Effective therapies for chronic or non-healing wounds are still lacking. These tissue insults often result in severe clinical complications (i.e., infections and/or amputation) and sometimes lead to patient death. Accordingly, several research groups have focused their efforts in finding innovative and powerful therapeutic strategies to overcome these issues. On the basis of these considerations, the comprehension of the molecular cascades behind these pathological conditions could allow the identification of molecules against chronic wounds. In this context, the regulation of the Protein Kinase C (PKC) cascade has gained relevance in the prevention and/or reparation of tissue damages. This class of phosphorylating enzymes has already been considered for different physiological and pathological pathways and modulation of such enzymes may be useful in reparative processes. Herein, the recent developments in this field will be disclosed, highlighting the pivotal role of PKC α and δ in regenerative medicine. Moreover, an overview of well-established PKC ligands, acting via the modulation of these isoenzymes, will be deeply investigated. This study is aimed at re-evaluating widely known PKC modulators, currently utilized for treating other diseases, as fruitful molecules in wound-healing.
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11
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Newton AC, Brognard J. Reversing the Paradigm: Protein Kinase C as a Tumor Suppressor. Trends Pharmacol Sci 2017; 38:438-447. [PMID: 28283201 PMCID: PMC5403564 DOI: 10.1016/j.tips.2017.02.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/02/2017] [Accepted: 02/03/2017] [Indexed: 12/20/2022]
Abstract
The discovery in the 1980s that protein kinase C (PKC) is a receptor for the tumor-promoting phorbol esters fueled the dogma that PKC is an oncoprotein. Yet 30+ years of clinical trials for cancer using PKC inhibitors not only failed, but in some instances worsened patient outcome. The recent analysis of cancer-associated mutations, from diverse cancers and throughout the PKC family, revealed that PKC isozymes are generally inactivated in cancer, supporting a tumor suppressive function. In keeping with a bona fide tumor suppressive role, germline causal loss-of-function (LOF) mutations in one isozyme have recently been identified in lymphoproliferative disorders. Thus, strategies in cancer treatment should focus on restoring rather than inhibiting PKC.
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Affiliation(s)
- Alexandra C Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093-0721, USA.
| | - John Brognard
- Laboratory of Cell and Developmental Signaling, National Cancer Institute at Frederick, Frederick, MD 21702, USA; Cancer Research UK Manchester Institute, Manchester, UK.
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12
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Callender J, Newton A. Conventional protein kinase C in the brain: 40 years later. Neuronal Signal 2017; 1:NS20160005. [PMID: 32714576 PMCID: PMC7373245 DOI: 10.1042/ns20160005] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/02/2017] [Accepted: 03/07/2017] [Indexed: 12/16/2022] Open
Abstract
Protein kinase C (PKC) is a family of enzymes whose members transduce a large variety of cellular signals instigated by the receptor-mediated hydrolysis of membrane phospholipids. While PKC has been widely implicated in the pathology of diseases affecting all areas of physiology including cancer, diabetes, and heart disease-it was discovered, and initially characterized, in the brain. PKC plays a key role in controlling the balance between cell survival and cell death. Its loss of function is generally associated with cancer, whereas its enhanced activity is associated with neurodegeneration. This review presents an overview of signaling by diacylglycerol (DG)-dependent PKC isozymes in the brain, and focuses on the role of the Ca2+-sensitive conventional PKC isozymes in neurodegeneration.
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Affiliation(s)
- Julia A. Callender
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093-0721, U.S.A
- Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, CA 92093-0721, U.S.A
| | - Alexandra C. Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093-0721, U.S.A
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Pany S, You Y, Das J. Curcumin Inhibits Protein Kinase Cα Activity by Binding to Its C1 Domain. Biochemistry 2016; 55:6327-6336. [PMID: 27776404 DOI: 10.1021/acs.biochem.6b00932] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Curcumin is a polyphenolic nutraceutical that acts on multiple biological targets, including protein kinase C (PKC). PKC is a family of serine/threonine kinases central to intracellular signal transduction. We have recently shown that curcumin selectively inhibits PKCα, but not PKCε, in CHO-K1 cells [Pany, S. (2016) Biochemistry 55, 2135-2143]. To understand which domain(s) of PKCα is responsible for curcumin binding and inhibitory activity, we made several domain-swapped mutants in which the C1 (combination of C1A and C1B) and C2 domains are swapped between PKCα and PKCε. Phorbol ester-induced membrane translocation studies using confocal microscopy and immunoblotting revealed that curcumin inhibited phorbol ester-induced membrane translocation of PKCε mutants, in which the εC1 domain was replaced with αC1, but not the PKCα mutant in which αC1 was replaced with the εC1 domain, suggesting that αC1 is a determinant for curcumin's inhibitory effect. In addition, curcumin inhibited membrane translocation of PKCε mutants, in which the εC1A and εC1B domains were replaced with the αC1A and αC1B domains, respectively, indicating the role of both αC1A and αC1B domains in curcumin's inhibitory effects. Phorbol 13-acetate inhibited the binding of curcumin to αC1A and αC1B with IC50 values of 6.27 and 4.47 μM, respectively. Molecular docking and molecular dynamics studies also supported the higher affinity of curcumin for αC1B than for αC1A. The C2 domain-swapped mutants were inactive in phorbol ester-induced membrane translocation. These results indicate that curcumin binds to the C1 domain of PKCα and highlight the importance of this domain in achieving PKC isoform selectivity.
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Affiliation(s)
- Satyabrata Pany
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
| | - Youngki You
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
| | - Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
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14
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Capuani B, Pacifici F, Pastore D, Palmirotta R, Donadel G, Arriga R, Bellia A, Di Daniele N, Rogliani P, Abete P, Sbraccia P, Guadagni F, Lauro D, Della-Morte D. The role of epsilon PKC in acute and chronic diseases: Possible pharmacological implications of its modulators. Pharmacol Res 2016; 111:659-667. [DOI: 10.1016/j.phrs.2016.07.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 07/22/2016] [Indexed: 02/06/2023]
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15
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Pany S, Majhi A, Das J. Selective Modulation of Protein Kinase C α over Protein Kinase C ε by Curcumin and Its Derivatives in CHO-K1 Cells. Biochemistry 2016; 55:2135-43. [PMID: 26983836 DOI: 10.1021/acs.biochem.6b00057] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Members of the protein kinase C (PKC) family of serine/threonine kinases regulate various cellular functions, including cell growth, differentiation, metabolism, and apoptosis. Modulation of isoform-selective activity of PKC by curcumin (1), the active constituent of Curcuma L., is poorly understood, and the literature data are inconsistent and obscure. The effect of curcumin (1) and its analogues, 4-[(2Z,6E)-3-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-5-oxohepta-2,6-dien-1-yl]-2-methoxyphenyl oleate (2), (9Z,12Z)-4-[(2Z,6E)-3-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-5-oxohepta-2,6-dien-1-yl]-2-methoxyphenyl octadeca-9,12-dienoate (3), (9Z,12Z,15Z)-4-[(2Z,6E)-3-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-5-oxohepta-2,6-dien-1-yl]-2-methoxyphenyl octadeca-9,12,15-trienoate (4), and (1E,6E)-1-[4-(hexadecyloxy)-3-methoxyphenyl]-7-(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione (5), and didemethylcurcumin (6) on the membrane translocation of PKCα, a conventional PKC, and PKCε, a novel PKC, has been studied in CHO-K1 cells, in which these PKC isoforms are endogenously expressed. Translocation of PKC from the cytosol to the membrane was measured using immunoblotting and confocal microscopy. 1 and 6 inhibited the TPA-induced membrane translocation of PKCα but not of PKCε. Modification of the hydroxyl group of curcumin with a long aliphatic chain containing unsaturated double bonds in 2-4 completely abolished this inhibition property. Instead, 2-4 showed significant translocation of PKCα but not of PKCε to the membrane. No membrane translocation was observed with 1, 6, or the analogue 5 having a saturated long chain for either PKCα or PKCε. 1 and 6 inhibited TPA-induced activation of ERK1/2, and 2-4 activated it. ERK1/2 is the downstream readout of PKC. These results show that the hydroxyl group of curcumin is important for PKC activity and the curcumin template can be useful in developing isoform specific PKC modulators for regulating a particular disease state.
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Affiliation(s)
- Satyabrata Pany
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
| | - Anjoy Majhi
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
| | - Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston , Houston, Texas 77204, United States
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16
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Thangsunan P, Tateing S, Hannongbua S, Suree N. Structural insights into the interactions of phorbol ester and bryostatin complexed with protein kinase C: a comparative molecular dynamics simulation study. J Biomol Struct Dyn 2015; 34:1561-75. [PMID: 26292580 DOI: 10.1080/07391102.2015.1084479] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Protein kinase C (PKC) isozymes are important regulatory enzymes that have been implicated in many diseases, including cancer, Alzheimer's disease, and in the eradication of HIV/AIDS. Given their potential clinical ramifications, PKC modulators, e.g. phorbol esters and bryostatin, are also of great interest in the drug development. However, structural details on the binding between PKC and its modulators, especially bryostatin - the highly potent and non-tumor promoting activator for PKCs, are still lacking. Here, we report the first comparative molecular dynamics study aimed at gaining structural insight into the mechanisms by which the PKC delta cys2 activator domain is used in its binding to phorbol ester and bryostatin-1. As anticipated in the phorbol ester binding, hydrogen bonds are formed through the backbone atoms of Thr242, Leu251, and Gly253 of PKC. However, the opposition of H-bond formation between Thr242 and Gly253 may cause the phorbol ester complex to become less stable when compared with the bryostatin binding. For the PKC delta-bryostatin complex, hydrogen bonds are formed between the Gly253 backbone carbonyl and the C30 carbomethoxy substituent of the ligand. Additionally, the indole Nε1 of the highly homologous Trp252 also forms an H-bond to the C20 ester group on bryostatin. Backbone fluctuations also suggest that this latter H-bond formation may abrogate the transient interaction between Trp252 and His269, thus dampening the fluctuations observed on the nearby Zn(2+)-coordinating residues. This new dynamic fluctuation dampening model can potentially benefit future design of new PKC modulators.
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Affiliation(s)
- Patcharapong Thangsunan
- a Graduate Program in Biotechnology , The Graduate School, Chiang Mai University , 239 Huay Kaew Rd, Suthep, Muang, Chiang Mai 50200 , Thailand.,b Faculty of Science, Department of Chemistry, Division of Biochemistry and Biochemical Technology , Chiang Mai University , 239 Huay Kaew Rd, Suthep, Muang, Chiang Mai 50200 , Thailand
| | - Suriya Tateing
- a Graduate Program in Biotechnology , The Graduate School, Chiang Mai University , 239 Huay Kaew Rd, Suthep, Muang, Chiang Mai 50200 , Thailand.,b Faculty of Science, Department of Chemistry, Division of Biochemistry and Biochemical Technology , Chiang Mai University , 239 Huay Kaew Rd, Suthep, Muang, Chiang Mai 50200 , Thailand
| | - Supa Hannongbua
- c Faculty of Science, Department of Chemistry , Kasetsart University , Bangkok 10900 , Thailand
| | - Nuttee Suree
- b Faculty of Science, Department of Chemistry, Division of Biochemistry and Biochemical Technology , Chiang Mai University , 239 Huay Kaew Rd, Suthep, Muang, Chiang Mai 50200 , Thailand
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17
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Borah R, Mamidi N, Panda S, Gorai S, Pathak SK, Manna D. Elucidating the interaction of γ-hydroxymethyl-γ-butyrolactone substituents with model membranes and protein kinase C-C1 domains. MOLECULAR BIOSYSTEMS 2015; 11:1389-99. [PMID: 25820877 DOI: 10.1039/c5mb00100e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The protein kinase C (PKC) family of proteins is an attractive drug target. Dysregulation of PKC-dependent signalling pathways is related to several human diseases like cancer, immunological and other diseases. We approached the problem of altering PKC activities by developing C1 domain-based PKC ligands. In this report γ-hydroxymethyl-γ-butyrolactone (HGL) substituents were investigated in an effort to develop small molecule-based PKC regulators with higher specificity for C1 domain than the endogenous diacylglycerols (DAGs). Extensive analysis of membrane-ligands interaction measurements revealed that the membrane-active compounds strongly interact with the lipid bilayers and the hydrophilic parts of compounds localize at the bilayer/water interface. The pharmacophores like hydroxymethyl, carbonyl groups and acyl-chain length of the compounds are crucial for their interaction with the C1 domain proteins. The potent compounds showed more than 17-fold stronger binding affinity for the C1 domains than DAG under similar experimental conditions. Nonradioactive kinase assay confirmed that these potent compounds have similar or better PKC dependent phosphorylation capabilities than DAG under similar experimental conditions. Hence, our findings reveal that these HGL analogues represent an attractive group of structurally simple C1 domain ligands that can be further structurally altered to improve their potencies.
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Affiliation(s)
- Rituparna Borah
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India.
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18
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Loy BA, Lesser AB, Staveness D, Billingsley KL, Cegelski L, Wender PA. Toward a biorelevant structure of protein kinase C bound modulators: design, synthesis, and evaluation of labeled bryostatin analogues for analysis with rotational echo double resonance NMR spectroscopy. J Am Chem Soc 2015; 137:3678-85. [PMID: 25710634 DOI: 10.1021/jacs.5b00886] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein kinase C (PKC) modulators are currently of great importance in preclinical and clinical studies directed at cancer, immunotherapy, HIV eradication, and Alzheimer's disease. However, the bound conformation of PKC modulators in a membrane environment is not known. Rotational echo double resonance (REDOR) NMR spectroscopy could uniquely address this challenge. However, REDOR NMR requires strategically labeled, high affinity ligands to determine interlabel distances from which the conformation of the bound ligand in the PKC-ligand complex could be identified. Here we report the first computer-guided design and syntheses of three bryostatin analogues strategically labeled for REDOR NMR analysis. Extensive computer analyses of energetically accessible analogue conformations suggested preferred labeling sites for the identification of the PKC-bound conformers. Significantly, three labeled analogues were synthesized, and, as required for REDOR analysis, all proved highly potent with PKC affinities (∼1 nM) on par with bryostatin. These potent and strategically labeled bryostatin analogues are new structural leads and provide the necessary starting point for projected efforts to determine the PKC-bound conformation of such analogues in a membrane environment, as needed to design new PKC modulators and understand PKC-ligand-membrane structure and dynamics.
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Affiliation(s)
- Brian A Loy
- †Department of Chemistry and ‡Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Adam B Lesser
- †Department of Chemistry and ‡Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Daryl Staveness
- †Department of Chemistry and ‡Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Kelvin L Billingsley
- †Department of Chemistry and ‡Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Lynette Cegelski
- †Department of Chemistry and ‡Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Paul A Wender
- †Department of Chemistry and ‡Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
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19
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Rossi D, Talman V, Gennäs GBA, Marra A, Picconi P, Nasti R, Serra M, Ann J, Amadio M, Pascale A, Tuominen RK, Yli-Kauhaluoma J, Lee J, Collina S. Beyond the affinity for protein kinase C: exploring 2-phenyl-3-hydroxypropyl pivalate analogues as C1 domain-targeting ligands. MEDCHEMCOMM 2015. [DOI: 10.1039/c4md00564c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over the past fifteen years, we reported the design and synthesis of different series of compounds targeting the C1 domain of protein kinase C (PKC) that were based on various templates.
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C1 domain-targeted isophthalates as protein kinase C modulators: structure-based design, structure–activity relationships and biological activities. Biochem Soc Trans 2014; 42:1543-9. [DOI: 10.1042/bst20140181] [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]
Abstract
Protein kinase C (PKC) is a serine/threonine kinase belonging to the AGC family. PKC isoenzymes are activated by phospholipid-derived second messengers, transmit their signal by phosphorylating specific substrates and play a pivotal role in the regulation of various cell functions, including metabolism, growth, differentiation and apoptosis. Therefore they represent an interesting molecular target for the treatment of several diseases, such as cancer and Alzheimer's disease. Adopting a structure-based approach on the crystal structure of the PKCδ C1B domain, our team has developed isophthalic acid derivatives that are able to modify PKC functions by binding to the C1 domain of the enzyme. Bis[3-(trifluoromethyl)benzyl] 5-(hydroxymethyl)isophthalate (HMI-1a3) and bis(1-ethylpentyl) 5-(hydroxymethyl)isophthalate (HMI-1b11) were selected from a set of compounds for further studies due to their high affinity for the C1 domains of PKCα and PKCδ. HMI-1a3 showed marked antiproliferative activity in HeLa cells whereas HMI-1b11 induced differentiation and supported neurite growth in SH-SY5Y cells. Our aim in the future is to improve the selectivity and potency of isophthalate derivatives, to clarify their mechanism of action in the cellular environment and to assess their efficacy in cell-based and in vivo disease models. HMI-1a3 has already been selected for a further project and redesigned to function as a probe immobilized on an affinity chromatography column. It will be used to identify cellular target proteins from cell lysates, providing new insights into the mechanism of action of HMI-1a3.
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21
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Talukdar D, Panda S, Borah R, Manna D. Membrane Interaction and Protein Kinase C-C1 Domain Binding Properties of 4-Hydroxy-3-(hydroxymethyl) Phenyl Ester Analogues. J Phys Chem B 2014; 118:7541-7553. [PMID: 24936745 DOI: 10.1021/jp5044305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein kinase C (PKC)-C1 domain targeted regulator development is considered as a potential therapeutic strategy for the treatment of cancer and immunological and other diseases. Efforts are underway to synthesize small molecules to achieve higher specificity for the C1-domain than the natural activator, diacylglycerols (DAGs). In this regard, we conveniently synthesized 4-hydroxy-3-(hydroxymethyl) phenyl ester analogues and measured in vitro C1-domain binding properties. We also investigated different physicochemical properties of the synthesized molecules, including aggregation behavior in aqueous solution and interaction with lipid bilayers, and others with an aim for better understanding of their C1-domain binding properties. The results showed that the membrane-active compounds aggregate in aqueous solution at a reasonably lower concentration and strongly interact with the lipid bilayer. The hydrophilic part of the compounds localize at the bilayer/water interface and accessible for C1-domain binding. Biophysical studies revealed that the hydroxyl, hydroxymethyl, and carbonyl groups and acyl chain length are important for their interaction with the C1-domain. The potent compound showed more than 10-fold stronger binding affinity for the C1-domains than DAG under similar experimental conditions. Therefore, our findings reveal that these ester analogues represent an attractive group of C1-domain ligands that can be further structurally modified to improve their binding and activity.
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Affiliation(s)
- Dipjyoti Talukdar
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
| | - Subhankar Panda
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
| | - Rituparna Borah
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
| | - Debasis Manna
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
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22
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Targeted activation of conventional and novel protein kinases C through differential translocation patterns. Mol Cell Biol 2014; 34:2370-81. [PMID: 24732802 DOI: 10.1128/mcb.00040-14] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Activation of the two ubiquitous families of protein kinases, protein kinase A (PKA) and protein kinase C (PKC), is thought to be independently coupled to stimulation of Gαs and Gαq, respectively. Live-cell confocal imaging of protein kinase C fluorescent protein fusion constructs revealed that simultaneous activation of Gαs and Gαq resulted in a differential translocation of the conventional PKCα to the plasma membrane while the novel PKCδ was recruited to the membrane of the endoplasmic reticulum (ER). We demonstrate that the PKCδ translocation was driven by a novel Gαs-cyclic AMP-EPAC-RAP-PLCε pathway resulting in specific diacylglycerol production at the membrane of the ER. Membrane-specific phosphorylation sensors revealed that directed translocation resulted in phosphorylation activity confined to the target membrane. Specific stimulation of PKCδ caused phosphorylation of the inositol-1,4,5-trisphosphate receptor and dampening of global Ca(2+) signaling revealed by graded flash photolysis of caged inositol-1,4,5-trisphosphate. Our data demonstrate a novel signaling pathway enabling differential decoding of incoming stimuli into PKC isoform-specific membrane targeting, significantly enhancing the versatility of cyclic AMP signaling, thus demonstrating the possible interconnection between the PKA and PKC pathways traditionally treated independently. We thus provide novel and elementary understanding and insights into intracellular signaling events.
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23
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Corticosteroids modulate the expression of the PKC-anchoring protein RACK-1 and cytokine release in THP-1 cells. Pharmacol Res 2014; 81:10-6. [PMID: 24462857 DOI: 10.1016/j.phrs.2014.01.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/01/2014] [Accepted: 01/11/2014] [Indexed: 12/20/2022]
Abstract
We demonstrated that cortisol reduces the expression of RACK-1 (Receptor for Activated C Kinase-1), a protein required for immune cell activation. The aim of this study was to evaluate whether and to what extent other clinically relevant corticosteroids may modulate RACK-1 expression. We used the human promyelocytic cell line THP-1 to investigate the effects of cortisol, prednisone, prednisolone, budesonide, betamethasone and methylprednisolone on RACK-1 expression and cytokine production. As anticipated, all corticosteroids inhibited at non-cytotoxic concentrations in a dose and time related manner LPS-induced TNF-α and IL-8 release, with budesonide, betamethasone and methylprednisolone being the most active followed by prednisolone, cortisol and prednisone. To a similar extent, all corticosteroids also reduced RACK-1 mRNA expression and RACK-1 protein levels as assessed by Real Time PCR and Western blot, respectively. Prednisone was the least potent compound while betamethasone and methylprednisolone where the most active. A good correlation was observed between RACK-1 mRNA or protein levels and cytokine release (Pearson r=0.7376, p=0.0471 for RACK-1 mRNA and TNF-α release, and Pearson r=0.8108, p=0.0252 for RACK-1 protein and IL-8 release). Mifepristone, a potent glucocorticoid receptor (GR) antagonist, completely prevented the effect of cortisol, demonstrating that RACK-1 downregulation is via GR. Furthermore, to by-pass the defective PKC activation due to the decrease in RACK-1, we used a RACK-1 pseudosubstrate, that directly activates PKC-beta. RACK-1 pseudosubstrate was able to restore LPS-induced cytokine production affected by cortisol, supporting the role of RACK-1 in the anti-inflammatory effect of corticosteroids. These results confirm the involvement of RACK-1 in immune cell activation and identify this protein as a novel transcriptional target of corticosteroid-induced anti-inflammatory effects.
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Mamidi N, Panda S, Borah R, Manna D. Synthesis and protein kinase C (PKC)-C1 domain binding properties of diacyltetrol based anionic lipids. MOL. BIOSYST. 2014; 10:3002-13. [DOI: 10.1039/c4mb00382a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Protein kinase C-C1 domain binding specificity of the anionic hybrid lipids.
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Affiliation(s)
- Narsimha Mamidi
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Assam 781039, India
| | - Subhankar Panda
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Assam 781039, India
| | - Rituparna Borah
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Assam 781039, India
| | - Debasis Manna
- Department of Chemistry
- Indian Institute of Technology Guwahati
- Assam 781039, India
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25
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Borah R, Talukdar D, Gorai S, Bain D, Manna D. Bilayer interaction and protein kinase C-C1 domain binding studies of kojic acid esters. RSC Adv 2014. [DOI: 10.1039/c4ra02352h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synthesis of kojic acid ester analogues and their lipid bilayer interaction and PKC-C1 domain binding properties have been demonstrated in this present work.
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Affiliation(s)
- Rituparna Borah
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
| | - Dipjyoti Talukdar
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
| | - Sukhamoy Gorai
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
| | - Dipankar Bain
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
| | - Debasis Manna
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
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26
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Mamidi N, Gorai S, Ravi B, Manna D. Physicochemical characterization of diacyltetrol-based lipids consisting of both diacylglycerol and phospholipid headgroups. RSC Adv 2014. [DOI: 10.1039/c4ra02495h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Synthesis and physicochemical properties of a family of diacyltetrol-based hybrid lipids, containing both diacylglycerol and anionic lipid headgroups within the same moiety, have been reported for the first time.
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Affiliation(s)
- Narsimha Mamidi
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
| | - Sukhamoy Gorai
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
| | - Bolledu Ravi
- Department of Chemical Engineering
- Indian Institute of Technology Guwahati
- , India
| | - Debasis Manna
- Department of Chemistry
- Indian Institute of Technology Guwahati
- , India
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27
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Soetikno V, Arozal W, Louisa M, Setiabudy R. New insight into the molecular drug target of diabetic nephropathy. Int J Endocrinol 2014; 2014:968681. [PMID: 24648839 PMCID: PMC3932220 DOI: 10.1155/2014/968681] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/29/2013] [Accepted: 12/23/2013] [Indexed: 01/07/2023] Open
Abstract
Diabetic nephropathy (DN) lowered quality of life and shortened life expectancy amongst those affected. Evidence indicates interaction between advanced glycation end products (AGEs), activated protein kinase C (PKC) and angiotensin II exacerbate the progression of DN. Inhibitors of angiotensin-converting enzyme (ACEIs), renin angiotensin aldosterone system (RAAS), AGEs, and PKC have been tested for slowing down the progression of DN. The exact molecular drug targets that lead to the amelioration of renal injury in DN are not well understood. This review summarizes the potential therapeutic targets, based on putative mechanism in the progression of the disease.
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Affiliation(s)
- Vivian Soetikno
- Department of Pharmacology and Therapeutic, Faculty of Medicine, University of Indonesia, Salemba Raya 6, Jakarta 10430, Indonesia
- *Vivian Soetikno:
| | - Wawaimuli Arozal
- Department of Pharmacology and Therapeutic, Faculty of Medicine, University of Indonesia, Salemba Raya 6, Jakarta 10430, Indonesia
| | - Melva Louisa
- Department of Pharmacology and Therapeutic, Faculty of Medicine, University of Indonesia, Salemba Raya 6, Jakarta 10430, Indonesia
| | - Rianto Setiabudy
- Department of Pharmacology and Therapeutic, Faculty of Medicine, University of Indonesia, Salemba Raya 6, Jakarta 10430, Indonesia
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28
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Talman V, Amadio M, Osera C, Sorvari S, Boije Af Gennäs G, Yli-Kauhaluoma J, Rossi D, Govoni S, Collina S, Ekokoski E, Tuominen RK, Pascale A. The C1 domain-targeted isophthalate derivative HMI-1b11 promotes neurite outgrowth and GAP-43 expression through PKCα activation in SH-SY5Y cells. Pharmacol Res 2013; 73:44-54. [PMID: 23643828 DOI: 10.1016/j.phrs.2013.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 04/22/2013] [Accepted: 04/23/2013] [Indexed: 11/28/2022]
Abstract
Protein kinase C (PKC) is a family of serine/threonine phosphotransferases ubiquitously expressed and involved in multiple cellular functions, such as proliferation, apoptosis and differentiation. The C1 domain of PKC represents an attractive drug target, especially for developing PKC activators. Dialkyl 5-(hydroxymethyl)isophthalates are a novel group of synthetic C1 domain ligands that exhibit antiproliferative effect in HeLa cervical carcinoma cells. Here we selected two isophthalates, HMI-1a3 and HMI-1b11, and characterized their effects in the human neuroblastoma cell line SH-SY5Y. Both of the active isophthalates exhibited significant antiproliferative and differentiation-inducing effects. Since HMI-1b11 did not impair cell survival even at the highest concentration tested (20μM), and supported neurite growth and differentiation of SH-SY5Y cells, we focused on studying its downstream signaling cascades and effects on gene expression. Consistently, genome-wide gene expression microarray and gene set enrichment analysis indicated that HMI-1b11 (10μM) induced changes in genes mainly related to cell differentiation. In particular, further studies revealed that HMI-1b11 exposure induced up-regulation of GAP-43, a marker for neurite sprouting and neuronal differentiation. These effects were induced by a 7-min HMI-1b11 treatment and specifically depended on PKCα activation, since pretreatment with the selective inhibitor Gö6976 abolished the up-regulation of GAP-43 protein observed at 12h. In parallel, we found that a 7-min exposure to HMI-1b11 induced PKCα accumulation to the cytoskeleton, an effect that was again prevented by pretreatment with Gö6976. Despite similar binding affinities to PKC, the isophthalates had different effects on PKC-dependent ERK1/2 signaling: HMI-1a3-induced ERK1/2 phosphorylation was transient, while HMI-1b11 induced a rapid but prolonged ERK1/2 phosphorylation. Overall our data are in accordance with previous studies showing that activation of the PKCα and ERK1/2 pathways participate in regulating neuronal differentiation. Furthermore, since PKC has been classified as one of the cognitive kinases, and activation of PKC is considered a potential therapeutic strategy for the treatment of cognitive disorders, our findings suggest that HMI-1b11 represents a promising lead compound in research aimed to prevent or counteract memory impairment.
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Affiliation(s)
- Virpi Talman
- Division of Pharmacology and Toxicology, Faculty of Pharmacy, University of Helsinki, FI-00014 Helsinki, Finland.
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PKC activation by resveratrol derivatives with unsaturated aliphatic chain. PLoS One 2012; 7:e52888. [PMID: 23285216 PMCID: PMC3528653 DOI: 10.1371/journal.pone.0052888] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 11/22/2012] [Indexed: 01/04/2023] Open
Abstract
Resveratrol (1) is a naturally occurring phytoalexin that affects a variety of human disease models, including cardio- and neuroprotection, immune regulation, and cancer chemoprevention. One of the possible mechanisms by which resveratrol affects these disease states is by affecting the cellular signaling network involving protein kinase C (PKC). PKC is the family of serine/threonine kinases, whose activity is inhibited by resveratrol. To develop PKC isotype selective molecules on the resveratrol scaffold, several analogs (2–5) of resveratrol with a long aliphatic chain varying with number of unsaturated doubled bonds have been synthesized, their cytotoxic effects on CHO-K1 cells are measured and their effects on the membrane translocation properties of PKCα and PKCε have been determined. The analogs showed less cytotoxic effects on CHO-K1 cells. Analog 4 with three unsaturated double bonds in its aliphatic chain activated PKCα, but not PKCε. Analog 4 also activated ERK1/2, the downstream proteins in the PKC signaling pathway. Resveratrol analogs 2–5, however, did not show any inhibition of the phorbol ester-induced membrane translocation for either PKCα or PKCε. Molecular docking of 4 into the activator binding site of PKCα revealed that the resveratrol moiety formed hydrogen bonds with the activator binding residues and the aliphatic chain capped the activator binding loops making its surface hydrophobic to facilitate its interaction with the plasma membrane. The present study shows that subtle changes in the resveratrol structure can have profound impact on the translocation properties of PKCs. Therefore, resveratrol scaffold can be used to develop PKC selective modulators for regulating associated disease states.
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Mamidi N, Borah R, Sinha N, Jana C, Manna D. Effects of Ortho Substituent Groups of Protocatechualdehyde Derivatives on Binding to the C1 Domain of Novel Protein Kinase C. J Phys Chem B 2012; 116:10684-92. [DOI: 10.1021/jp304787j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Narsimha Mamidi
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Rituparna Borah
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Narayan Sinha
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Chandramohan Jana
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Debasis Manna
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
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Role of protein kinase C in the activation of store-operated Ca2+ entry in airway smooth muscle cells. ACTA ACUST UNITED AC 2012; 32:303-310. [DOI: 10.1007/s11596-012-0053-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Indexed: 12/20/2022]
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Mamidi N, Gorai S, Sahoo J, Manna D. Alkyl cinnamates as regulator for the C1 domain of protein kinase C isoforms. Chem Phys Lipids 2012; 165:320-30. [DOI: 10.1016/j.chemphyslip.2012.02.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 02/22/2012] [Accepted: 02/24/2012] [Indexed: 12/11/2022]
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Mamidi N, Gorai S, Mukherjee R, Manna D. Development of diacyltetrol lipids as activators for the C1 domain of protein kinase C. MOLECULAR BIOSYSTEMS 2012; 8:1275-85. [PMID: 22301880 DOI: 10.1039/c2mb05452c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The protein kinase C (PKC) family of serine/threonine kinases is an attractive drug target for the treatment of cancer and other diseases. Diacylglycerol (DAG), phorbol esters and others act as ligands for the C1 domain of PKC isoforms. Inspection of the crystal structure of the PKCδ C1b subdomain in complex with phorbol-13-O-acetate shows that one carbonyl group and two hydroxyl groups play pivotal roles in recognition of the C1 domain. To understand the importance of two hydroxyl groups of phorbol esters in PKC binding and to develop effective PKC activators, we synthesized DAG like diacyltetrols (DATs) and studied binding affinities with C1b subdomains of PKCδ and PKCθ. DATs, with the stereochemistry of natural DAGs at the sn-2 position, were synthesized from (+)-diethyl L-tartrate in four to seven steps as single isomers. The calculated EC(50) values for the short and long chain DATs varied in the range of 3-6 μM. Furthermore, the fluorescence anisotropy values of the proteins were increased in the presence of DATs in a similar manner to that of DAGs. Molecular docking of DATs (1b-4b) with PKCδ C1b showed that the DATs form hydrogen bonds with the polar residues and backbone of the protein, at the same binding site, as that of DAG and phorbol esters. Our findings reveal that DATs represent an attractive group of C1 domain ligands that can be used as research tools or further structurally modified for potential drug development.
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Affiliation(s)
- Narsimha Mamidi
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
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Affiliation(s)
- Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, USA
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Gupta SC, Prasad S, Kim JH, Patchva S, Webb LJ, Priyadarsini IK, Aggarwal BB. Multitargeting by curcumin as revealed by molecular interaction studies. Nat Prod Rep 2011; 28:1937-55. [PMID: 21979811 DOI: 10.1039/c1np00051a] [Citation(s) in RCA: 410] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Curcumin (diferuloylmethane), the active ingredient in turmeric (Curcuma longa), is a highly pleiotropic molecule with anti-inflammatory, anti-oxidant, chemopreventive, chemosensitization, and radiosensitization activities. The pleiotropic activities attributed to curcumin come from its complex molecular structure and chemistry, as well as its ability to influence multiple signaling molecules. Curcumin has been shown to bind by multiple forces directly to numerous signaling molecules, such as inflammatory molecules, cell survival proteins, protein kinases, protein reductases, histone acetyltransferase, histone deacetylase, glyoxalase I, xanthine oxidase, proteasome, HIV1 integrase, HIV1 protease, sarco (endo) plasmic reticulum Ca(2+) ATPase, DNA methyltransferases 1, FtsZ protofilaments, carrier proteins, and metal ions. Curcumin can also bind directly to DNA and RNA. Owing to its β-diketone moiety, curcumin undergoes keto-enol tautomerism that has been reported as a favorable state for direct binding. The functional groups on curcumin found suitable for interaction with other macromolecules include the α, β-unsaturated β-diketone moiety, carbonyl and enolic groups of the β-diketone moiety, methoxy and phenolic hydroxyl groups, and the phenyl rings. Various biophysical tools have been used to monitor direct interaction of curcumin with other proteins, including absorption, fluorescence, Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy, surface plasmon resonance, competitive ligand binding, Forster type fluorescence resonance energy transfer (FRET), radiolabeling, site-directed mutagenesis, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), immunoprecipitation, phage display biopanning, electron microscopy, 1-anilino-8-naphthalene-sulfonate (ANS) displacement, and co-localization. Molecular docking, the most commonly employed computational tool for calculating binding affinities and predicting binding sites, has also been used to further characterize curcumin's binding sites. Furthermore, the ability of curcumin to bind directly to carrier proteins improves its solubility and bioavailability. In this review, we focus on how curcumin directly targets signaling molecules, as well as the different forces that bind the curcumin-protein complex and how this interaction affects the biological properties of proteins. We will also discuss various analogues of curcumin designed to bind selective targets with increased affinity.
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Affiliation(s)
- Subash C Gupta
- Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, 77030, USA
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Das J, Pany S, Panchal S, Majhi A, Rahman GM. Binding of isoxazole and pyrazole derivatives of curcumin with the activator binding domain of novel protein kinase C. Bioorg Med Chem 2011; 19:6196-202. [PMID: 21975067 DOI: 10.1016/j.bmc.2011.09.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 09/08/2011] [Indexed: 11/26/2022]
Abstract
The protein kinase C (PKC) family of serine/threonine kinases is an attractive drug target because of its involvement in the regulation of various cellular functions, including cell growth, differentiation, metabolism, and apoptosis. The endogenous PKC activator diacylglycerol contains two long carbon chains, which are attached to the glycerol moiety via ester linkage. Natural product curcumin (1), the active constituent of Curcuma L., contains two carbonyl and two hydroxyl groups. It modulates PKC activity and binds to the activator binding site (Majhi et al., Bioorg. Med. Chem.2010, 18, 1591). To investigate the role of the carbonyl and hydroxyl groups of curcumin in PKC binding and to develop curcumin derivatives as effective PKC modulators, we synthesized several isoxazole and pyrazole derivatives of curcumin (2-6), characterized their absorption and fluorescence properties, and studied their interaction with the activator-binding second cysteine-rich C1B subdomain of PKCδ, PKCε and PKCθ. The EC(50)s of the curcumin derivatives for protein fluorescence quenching varied in the range of 3-25 μM. All the derivatives showed higher binding with the PKCθC1B compared with PKCδC1B and PKCεC1B. Fluorescence emission maxima of 2-5 were blue shifted in the presence of the C1B domains, confirming their binding to the protein. Molecular docking revealed that hydroxyl, carbonyl and pyrazole ring of curcumin (1), pyrazole (2), and isoxazole (4) derivatives form hydrogen bonds with the protein residues. The present result shows that isoxazole and pyrazole derivatives bind to the activator binding site of novel PKCs and both carbonyl and hydroxy groups of curcumin play roles in the binding process, depending on the nature of curcumin derivative and the PKC isotype used.
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Affiliation(s)
- Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States.
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Das J, Pany S, Majhi A. Chemical modifications of resveratrol for improved protein kinase C alpha activity. Bioorg Med Chem 2011; 19:5321-33. [PMID: 21880495 DOI: 10.1016/j.bmc.2011.08.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/28/2011] [Accepted: 08/03/2011] [Indexed: 12/20/2022]
Abstract
Resveratrol (1) is a naturally occurring phytoalexin that affects a variety of human disease models, including cardio- and neuroprotection, immune regulation, and cancer chemoprevention. One of the possible mechanisms by which resveratrol affects these disease states is by affecting the cellular signaling network involving protein kinase C alpha (PKCα). PKCα is a member of the family of serine/threonine kinases, whose activity is inhibited by resveratrol. To study the structure-activity relationship, several monoalkoxy, dialkoxy and hydroxy analogs of resveratrol have been synthesized, tested for their cytotoxic effects on HEK293 cells, measured their effects on the membrane translocation properties of PKCα in the presence and absence of the PKC activator TPA, and studied their binding with the activator binding domain of PKCα. The analogs showed less cytotoxic effects on HEK293 cells and caused higher membrane translocation (activation) than that of resveratrol. Among all the analogs, 3, 16 and 25 showed significantly higher activation than resveratrol. Resveratrol analogs, however, inhibited phorbol ester-induced membrane translocation, and the inhibition was less than that of resveratrol. Binding studies using steady state fluorescence spectroscopy indicated that resveratrol and the analogs bind to the second cysteine-rich domain of PKCα. The molecular docking studies indicated that resveratrol and the analogs interact with the protein by forming hydrogen bonds through its hydroxyl groups. These results signify that molecules developed on a resveratrol scaffold can attenuate PKCα activity and this strategy can be used to regulate various disease states involving PKCα.
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Affiliation(s)
- Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, United States.
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Semsri S, Krig SR, Kotelawala L, Sweeney CA, Anuchapreeda S. Inhibitory mechanism of pure curcumin on Wilms' tumor 1 (WT1) gene expression through the PKCα signaling pathway in leukemic K562 cells. FEBS Lett 2011; 585:2235-42. [PMID: 21658388 DOI: 10.1016/j.febslet.2011.05.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 03/29/2011] [Accepted: 05/16/2011] [Indexed: 11/19/2022]
Abstract
The aim of this study was to investigate the inhibitory mechanism of pure curcumin on WT1 expression in leukemic K562 cells. Pure curcumin suppressed WT1 expression, independent of effects on protein degradation or WT1 mRNA stability. Chromatin immunoprecipitation and reporter gene assays indicate that pure curcumin treatment attenuates WT1 auto-regulation. Interestingly, PKCα inhibition mimicks the repressive effects of pure curcumin in K562 cells. Conversely, myristoylated PKCα over-expression increased WT1 expression and reversed the inhibitory effect of pure curcumin. Our study indicates that pure curcumin attenuates WT1 auto-regulatory function through inhibition of PKCα signaling in K562 cells.
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Affiliation(s)
- Suwanna Semsri
- Division of Clinical Microscopy, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
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Sheremet YA, Yemets AI, Vissenberg K, Verbelen JP, Blume YB. Effects of inhibitors of serine/threonine protein kinases on Arabidopsis thaliana root morphology and microtubule organization in its cells. ACTA ACUST UNITED AC 2010. [DOI: 10.1134/s1990519x10040139] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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40
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Abstract
Nestled at the tip of a branch of the kinome, protein kinase C (PKC) family members are poised to transduce signals emanating from the cell surface. Cell membranes provide the platform for PKC function, supporting the maturation of PKC through phosphorylation, its allosteric activation by binding specific lipids, and, ultimately, promoting the downregulation of the enzyme. These regulatory mechanisms precisely control the level of signaling-competent PKC in the cell. Disruption of this regulation results in pathophysiological states, most notably cancer, where PKC levels are often grossly altered. This review introduces the PKC family and then focuses on recent advances in understanding the cellular regulation of its diacylglycerol-regulated members.
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Affiliation(s)
- Alexandra C Newton
- Dept. of Pharmacology, Univ. of California at San Diego, La Jolla, 92093, USA.
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Majhi A, Rahman GM, Panchal S, Das J. Binding of curcumin and its long chain derivatives to the activator binding domain of novel protein kinase C. Bioorg Med Chem 2010; 18:1591-8. [PMID: 20100661 PMCID: PMC2843403 DOI: 10.1016/j.bmc.2009.12.075] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Revised: 12/24/2009] [Accepted: 12/31/2009] [Indexed: 01/08/2023]
Abstract
Protein kinase C (PKC) is a family of serine/threonine kinases that play a central role in cellular signal transduction. The second messenger diacylglycerol having two long carbon chains acts as the endogenous ligand for the PKCs. Polyphenol curcumin, the active constituent of Curcuma longa is an anti-cancer agent and modulates PKC activity. To develop curcumin derivatives as effective PKC activators, we synthesized several long chain derivatives of curcumin, characterized their absorption and fluorescence properties and studied their interaction with the activator binding second cysteine-rich C1B subdomain of PKCdelta, PKCepsilon and PKCtheta. Curcumin (1) and its C16 long chain analog (4) quenched the intrinsic fluorescence of PKCdeltaC1B, PKCepsilonC1B and PKCthetaC1B in a manner similar to that of PKC activator 12-O-tetradecanoylphorbol 13-acetate (TPA). The EC(50)s of the curcumin derivatives for fluorescence quenching varied in the range of 4-11 microM, whereas, EC(50)s for TPA varied in the range of 3-6 microM. Fluorescence emission maxima of 1 and 4 were blue shifted and the fluorescence anisotropy values were increased in the presence of the C1B domains in a manner similar to that shown by the fluorescent analog of TPA, sapintoxin-D, confirming that they were bound to the proteins. Molecular docking of 1 and 4 with novel PKC C1B revealed that both the molecules form hydrogen bonds with the protein residues. The present result shows that curcumin and its long chain derivatives bind to the C1B subdomain of novel PKCs and can be further modified structurally to improve its binding and activity.
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Affiliation(s)
- Anjoy Majhi
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204
| | - Ghazi M. Rahman
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204
| | - Shyam Panchal
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204
| | - Joydip Das
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204
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Nitti M, Furfaro AL, Cevasco C, Traverso N, Marinari UM, Pronzato MA, Domenicotti C. PKC delta and NADPH oxidase in retinoic acid-induced neuroblastoma cell differentiation. Cell Signal 2010; 22:828-35. [PMID: 20074641 DOI: 10.1016/j.cellsig.2010.01.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 12/10/2009] [Accepted: 01/05/2010] [Indexed: 01/24/2023]
Abstract
The role of reactive oxygen species (ROS) in the regulation of signal transduction processes has been well established in many cell types and recently the fine tuning of redox signalling in neurons received increasing attention. With regard to this, the involvement of NADPH oxidase (NOX) in neuronal pathophysiology has been proposed but deserves more investigation. In the present study, we used SH-SY5Y neuroblastoma cells to analyse the role of NADPH oxidase in retinoic acid (RA)-induced differentiation, pointing out the involvement of protein kinase C (PKC) delta in the activation of NOX. Retinoic acid induces neuronal differentiation as revealed by the increased expression of MAP2, the decreased cell doubling rate, and the gain in neuronal morphological features and these events are accompanied by the increased expression level of PKC delta and p67(phox), one of the components of NADPH oxidase. Using DPI to inhibit NOX activity we show that retinoic acid acts through this enzyme to induce morphological changes linked to the differentiation. Moreover, using rottlerin to inhibit PKC delta or transfection experiments to overexpress it, we show that retinoic acid acts through this enzyme to induce MAP2 expression and to increase p67(phox) membrane translocation leading to NADPH oxidase activation. These findings identify the activation of PKC delta and NADPH oxidase as crucial steps in RA-induced neuroblastoma cell differentiation.
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Affiliation(s)
- Mariapaola Nitti
- Department of Experimental Medicine, University of Genoa, Italy.
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Boije af Gennäs G, Talman V, Aitio O, Ekokoski E, Finel M, Tuominen RK, Yli-Kauhaluoma J. Design, synthesis, and biological activity of isophthalic acid derivatives targeted to the C1 domain of protein kinase C. J Med Chem 2009; 52:3969-81. [PMID: 19438240 DOI: 10.1021/jm900229p] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein kinase C (PKC) is a widely studied molecular target for the treatment of cancer and other diseases. We have approached the issue of modifying PKC function by targeting the C1 domain in the regulatory region of the enzyme. Using the X-ray crystal structure of the PKC delta C1b domain, we have discovered conveniently synthesizable derivatives of dialkyl 5-(hydroxymethyl)isophthalate that can act as potential C1 domain ligands. Structure-activity studies confirmed that the important functional groups predicted by modeling were indispensable for binding to the C1 domain and that the modifications of these groups diminished binding. The most promising compounds were able to displace radiolabeled phorbol ester ([(3)H]PDBu) from PKC alpha and delta at K(i) values in the range of 200-900 nM. Furthermore, the active isophthalate derivatives could modify PKC activation in living cells either by inducing PKC-dependent ERK phosphorylation or by inhibiting phorbol-induced ERK phosphorylation. In conclusion, we report here, for the first time, that derivatives of isophthalic acid represent an attractive novel group of C1 domain ligands that can be used as research tools or further modified for potential drug development.
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Affiliation(s)
- Gustav Boije af Gennäs
- Division of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Helsinki, FI-00014 Helsinki, Finland
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Coutinho I, Pereira G, Simões MF, Côrte-Real M, Gonçalves J, Saraiva L. Selective activation of protein kinase C-delta and -epsilon by 6,11,12,14-tetrahydroxy-abieta-5,8,11,13-tetraene-7-one (coleon U). Biochem Pharmacol 2009; 78:449-59. [PMID: 19413996 DOI: 10.1016/j.bcp.2009.04.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 04/26/2009] [Accepted: 04/27/2009] [Indexed: 10/20/2022]
Abstract
6,11,12,14-tetrahydroxy-abieta-5,8,11,13-tetraene-7-one (coleon U) is a diterpene compound isolated from Plectranthus grandidentatus with an antiproliferative effect on several human cancer cell lines. Herein, we studied the modulatory activity of coleon U on individual isoforms of the three protein kinase C (PKC) subfamilies, classical (cPKC-alpha and -betaI), novel (nPKC-delta and -epsilon) and atypical (aPKC-zeta), using a yeast PKC assay. The results showed that, whereas the PKC activator phorbol-12-myristate-13-acetate (PMA) activated every PKC tested except aPKC, coleon U had no effect on aPKC and cPKCs. Besides, the effect of coleon U on nPKCs was higher than that of PMA. This revealed that coleon U was a potent and selective activator of nPKCs. The isoform-selectivity of coleon U for nPKC-delta and -epsilon was confirmed using an in vitro PKC assay. Most importantly, while PMA activated nPKCs inducing an isoform translocation from the cytosol to the plasma membrane and a G2/M cell cycle arrest, coleon U induced nPKCs translocation to the nucleus and a metacaspase- and mitochondrial-dependent apoptosis. This work therefore reconstitutes in yeast distinct subcellular translocations of a PKC isoform and the subsequent distinct cellular responses reported for mammalian cells. Together, our study identifies a new isoform-selective PKC activator with promising pharmacological applications. Indeed, since coleon U has no effect on cPKCs and aPKC, recognised as anti-apoptotic proteins, and selectively induces an apoptotic pathway dependent on nPKC-delta and -epsilon activation, it represents a promising compound for evaluation as an anti-cancer drug.
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Affiliation(s)
- I Coutinho
- Laboratório de Microbiologia, REQUIMTE/CEQUP, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 164, 4050-047 Porto, Portugal
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45
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Purification and characterization of a new Ca2+-dependent protein kinase C in mussel (Mytilus galloprovincialis Lmk.) mantle. Mol Cell Biochem 2009; 327:47-52. [DOI: 10.1007/s11010-009-0041-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 01/28/2009] [Indexed: 01/19/2023]
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46
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Affiliation(s)
- Alexandra C Newton
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92130-0721, USA.
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47
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Lanni C, Lenzken SC, Pascale A, Del Vecchio I, Racchi M, Pistoia F, Govoni S. Cognition enhancers between treating and doping the mind. Pharmacol Res 2008; 57:196-213. [DOI: 10.1016/j.phrs.2008.02.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 02/07/2008] [Accepted: 02/08/2008] [Indexed: 11/25/2022]
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Selvatici R, Falzarano S, Franceschetti L, Mollica A, Guerrini R, Siniscalchi A, Spisani S. Study of synthetic peptides derived from the PKI55 protein, a protein kinase C modulator, in human neutrophils stimulated by the methyl ester derivative of the hydrophobic N-formyl tripeptide for-Met-Leu-Phe-OH. FEBS J 2008; 275:449-57. [PMID: 18167144 DOI: 10.1111/j.1742-4658.2007.06212.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Elucidation of the involvement of protein kinase C subtypes in several diseases is an important challenge for the future development of new drug targets. We previously identified the PKI55 protein, which acts as a protein kinase C modulator, establishing a feedback loop of inhibition. The PKI55 protein is able to penetrate the cell membrane of activated human T-lymphocytes and to inhibit the activity of alpha, beta(1) and beta(2) protein kinase C isoforms. The present study aimed to identify the minimal amino acid sequence of PKI55 that is able to inhibit the enzyme activity of protein kinase C. Peptides derived from both C- and N-terminal sequences were synthesized and initially assayed in rat brain protein kinase C to identify which part of the entire protein maintained the in vitro effects described for PKI55, and then the active peptides were tested on the isoforms alpha, beta(1), beta(2), gamma, delta, epsilon and zeta to identify their specific inhibition properties. Specific protein kinase C isoforms have been associated with the activation of specific signal transduction pathways involved in inflammatory responses. Thus, the potential therapeutic role of the selected peptides has been studied in polymorphonuclear leukocytes activated by the methyl ester derivative of the hydrophobic N-formyl tripeptide for-Met-Leu-Phe-OH to evaluate their ability to modulate chemotaxis, superoxide anion production and lysozyme release. These studies have shown that only chemotactic function is significantly inhibited by these peptides, whereas superoxide anion production and lysozyme release remain unaffected. Western blotting experiments also demonstrated a selective reduction in the levels of the protein kinase C beta(1) isoform, which was previously demonstrated to be associated with the polymorphonuclear leukocyte chemotactic response.
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Affiliation(s)
- Rita Selvatici
- Dipartimento di Medicina Sperimentale e Diagnostica, Sezione Genetica Medica, Università degli Studi di Ferrara, Italy.
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Walker JW. Protein scaffolds, lipid domains and substrate recognition in protein kinase C function: implications for rational drug design. Handb Exp Pharmacol 2008:185-203. [PMID: 18491053 DOI: 10.1007/978-3-540-72843-6_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Protein kinase C (PKC) represents a family of lipid-regulated protein kinases with ubiquitous expression throughout the animal kingdom. High fidelity in PKC phosphorylation of intended target substrates is crucial for normal cell and tissue function. Therefore, it is likely that multiple interdependent factors contribute to determining substrate specificity in vivo, including divalent cation binding, substrate recognition motifs, local lipid heterogeneity and protein scaffolds. This review provides an overview of targeting mechanisms for the three subclasses of PKC isoforms, conventional, novel and atypical, with an emphasis on how they bind to substrates, lipids/lipid microdomains and multifunctional protein scaffolds. The diversity of interactions between PKC isoforms and their immediate environment is extensive, suggesting that systems biology approaches including proteomics and network modeling may be important strategies for rational drug design in the future.
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Affiliation(s)
- J W Walker
- Department of Physiology, Director of Human Proteomics Program, University of Wisconsin, Madison, WI 53706, USA.
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Amadio M, Scapagnini G, Lupo G, Drago F, Govoni S, Pascale A. PKCbetaII/HuR/VEGF: A new molecular cascade in retinal pericytes for the regulation of VEGF gene expression. Pharmacol Res 2007; 57:60-6. [PMID: 18206386 DOI: 10.1016/j.phrs.2007.11.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 11/26/2007] [Accepted: 11/28/2007] [Indexed: 11/18/2022]
Abstract
Vascular endothelial growth factor (VEGF)-induced new vessels formation is a key event in diabetic retinopathy, a severe progressive multistage pathology. Literature data indicate that protein kinase C (PKC) is involved in the control of VEGF expression, but, so far, no data are available on the molecular pathway underlying this process. Within this context, we suggest the existence of a new molecular cascade, operating in retinal bovine pericytes and involving PKCbetaII, the mRNA-stabilizing protein HuR, and VEGF. In particular we show that PKCbetaII activation is responsible, through the RNA-binding protein HuR, for the increase of VEGF protein content and its release in the medium. The specificity of the PKCbetaII involvement is confirmed by experiments performed with the LY379196 compound, a selective PKCbetaII inhibitor. Following acute high-glucose insult this pathway seems still functioning, suggesting that a brief exposure to glucose does not compromise this molecular cascade in pericytes. A better understanding on this new pathway could open novel opportunities for the development of innovative pharmacological therapies useful in pathologies where VEGF plays a key role such as in diabetic retinopathy.
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Affiliation(s)
- Marialaura Amadio
- Department of Experimental and Applied Pharmacology, Via Taramelli 14, 27100 Pavia, Italy.
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