15 results on '"Hariharan, Saminathan"'
Search Results
2. Fyn Kinase-Mediated PKCδ Y311 Phosphorylation Induces Dopaminergic Degeneration in Cell Culture and Animal Models: Implications for the Identification of a New Pharmacological Target for Parkinson’s Disease
- Author
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Hariharan Saminathan, Anamitra Ghosh, Danhui Zhang, Chunjuan Song, Huajun Jin, Vellareddy Anantharam, Arthi Kanthasamy, and Anumantha G. Kanthasamy
- Subjects
Fyn ,PKCδ ,neurodegeneration ,phosphorylation ,kinase ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Oxidative stress, neuroinflammation and apoptosis are some of the key etiological factors responsible for dopamin(DA)ergic degeneration during Parkinson’s disease (PD), yet the downstream molecular mechanisms underlying neurodegeneration are largely unknown. Recently, a genome-wide association study revealed the FYN gene to be associated with PD, suggesting that Fyn kinase could be a pharmacological target for PD. In this study, we report that Fyn-mediated PKCδ tyrosine (Y311) phosphorylation is a key event preceding its proteolytic activation in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinsonism. MPP+/MPTP induced Fyn kinase activation in N27 DAergic neuronal cells and the mouse substantia nigra. PKCδ-Y311 phosphorylation by activated Fyn initiates the apoptotic caspase-signaling cascade during DAergic degeneration. Pharmacological attenuation of Fyn activity protected DAergic neurons from MPP+-induced degeneration in primary mesencephalic neuronal cultures. We further employed Fyn wild-type and Fyn knockout (KO) mice to confirm whether Fyn is a valid pharmacological target of DAergic neurodegeneration. Primary mesencephalic neurons from Fyn KO mice were greatly protected from MPP+-induced DAergic cell death, neurite loss and DA reuptake loss. Furthermore, Fyn KO mice were significantly protected from MPTP-induced PKCδ-Y311 phosphorylation, behavioral deficits and nigral DAergic degeneration. This study thus unveils a mechanism by which Fyn regulates PKCδ′s pro-apoptotic function and DAergic degeneration. Pharmacological inhibitors directed at Fyn activation could prove to be a novel therapeutic target in the delay or halting of selective DAergic degeneration during PD.
- Published
- 2021
- Full Text
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3. Discovery and Optimization of Biaryl Alkyl Ethers as a Novel Class of Highly Selective, CNS-Penetrable, and Orally Active Adaptor Protein-2-Associated Kinase 1 (AAK1) Inhibitors for the Potential Treatment of Neuropathic Pain
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Guanglin Luo, Ling Chen, Walter A. Kostich, Brian Hamman, Jason Allen, Amy Easton, Clotilde Bourin, Michael Gulianello, Jonathan Lippy, Susheel Nara, Sreenivasulu Naidu Pattipati, Kumaran Dandapani, Manoj Dokania, Pradeep Vattikundala, Vivek Sharma, Saravanan Elavazhagan, Manoj Kumar Verma, Manish Lal Das, Santosh Wagh, Anand Balakrishnan, Benjamin M. Johnson, Kenneth S. Santone, George Thalody, Rex Denton, Hariharan Saminathan, Vinay K. Holenarsipur, Anoop Kumar, Abhijith Rao, Siva Prasad Putlur, Sarat Kumar Sarvasiddhi, Ganesh Shankar, Justin V. Louis, Manjunath Ramarao, Charles M. Conway, Yu-Wen Li, Rick Pieschl, Yuan Tian, Yang Hong, Linda Bristow, Charles F. Albright, Joanne J. Bronson, John E. Macor, and Carolyn D. Dzierba
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Mice ,Structure-Activity Relationship ,Spinal Cord ,Anesthetics, General ,Drug Discovery ,Animals ,Neuralgia ,Molecular Medicine ,Protein Kinase Inhibitors ,Ethers ,Rats - Abstract
Recent mouse knockout studies identified adapter protein-2-associated kinase 1 (AAK1) as a viable target for treating neuropathic pain. BMS-986176/LX-9211 (
- Published
- 2022
4. Discovery of (S)-1-((2′,6-Bis(difluoromethyl)-[2,4′-bipyridin]-5-yl)oxy)-2,4-dimethylpentan-2-amine (BMS-986176/LX-9211): A Highly Selective, CNS Penetrable, and Orally Active Adaptor Protein-2 Associated Kinase 1 Inhibitor in Clinical Trials for the Treatment of Neuropathic Pain
- Author
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Guanglin Luo, Ling Chen, Walter A. Kostich, Brian Hamman, Jason Allen, Amy Easton, Clotilde Bourin, Michael Gulianello, Jonathan Lippy, Susheel Nara, Tarun Kumar Maishal, Kamalraj Thiyagarajan, Prasadrao Jalagam, Sreenivasulu Naidu Pattipati, Kumaran Dandapani, Manoj Dokania, Pradeep Vattikundala, Vivek Sharma, Saravanan Elavazhagan, Manoj Kumar Verma, Manish Lal Das, Santosh Wagh, Anand Balakrishnan, Benjamin M. Johnson, Kenneth S. Santone, George Thalody, Rex Denton, Hariharan Saminathan, Vinay K. Holenarsipur, Anoop Kumar, Abhijith Rao, Siva Prasad Putlur, Sarat Kumar Sarvasiddhi, Ganesh Shankar, Justin V. Louis, Manjunath Ramarao, Charles M. Conway, Yu-Wen Li, Rick Pieschl, Yuan Tian, Yang Hong, Jonathan Ditta, Arvind Mathur, Jianqing Li, Daniel Smith, Joseph Pawluczyk, Dawn Sun, Shiuhang Yip, Dauh-Rurng Wu, Muthalagu Vetrichelvan, Anuradha Gupta, Alan Wilson, Suma Gopinathan, Suman Wason, Linda Bristow, Charles F. Albright, Joanne J. Bronson, John E. Macor, and Carolyn D. Dzierba
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Drug Discovery ,Molecular Medicine - Published
- 2022
5. Pharmacological inhibition of PTEN rescues dopaminergic neurons by attenuating apoptotic and neuroinflammatory signalling events
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Aishwarya Mary Johnson, Sara Jose, Abdul Rasheed Palakkot, Farheen Badrealam Khan, Jaleel Kizhakkayil, Shamma Ali Abdulla AlNaqbi, Mark GH Scott, Mohammed Akhli Ayoub, Richard Gordon, and Hariharan Saminathan
- Abstract
Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by a selective degeneration of dopaminergic neurons in the ventral mid-brain of humans called substantia nigra. This results in an irreversible and debilitating motor dysfunction. Though both genetic and idiopathic factors are implicated in the disease etiology, idiopathic PD comprise the majority of clinical cases and is caused due to environmental toxicants and oxidative stress. Activation of Fyn kinase has been implicated to be an early signalling event that primes both neuroinflammatory and neurodegenerative events associated with dopaminergic cell death. Fyn kinase is activated by dephosphorylation at the negatively regulating tyrosine site by tyrosine phosphatases. However, the tyrosine phosphatase that dephosphorylates and activates Fyn kinase is unidentified. One of the tyrosine phosphatases - PTEN (Phosphatase and Tensin homolog deleted on chromosome 10) a lipid and protein tyrosine phosphatase pathological roles in causing Parkinson’s disease has been previously studied in experimental models. We sought to study if PTEN would be the upstream regulator of Fyn activation in PD models. Our findings demonstrate for the first time that PTEN is a very early stress-sensor in response to oxidative stress and neurodegenerative toxicants in in vitro models of PD. Pharmacological inhibition of PTEN attenuates Fyn kinase and rescues dopaminergic neurons from neurotoxicants induced cytotoxicity. Our findings also identify PTEN’s additional and novel roles in contributing to mitochondrial dysfunction and neuroinflammatory pathways, both of which contribute to neurodegenerative processes. Taken together, we have identified PTEN as a disease course altering pharmacological target that may be further validated for the development of novel therapeutic strategies.
- Published
- 2022
6. Discovery of (
- Author
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Guanglin, Luo, Ling, Chen, Walter A, Kostich, Brian, Hamman, Jason, Allen, Amy, Easton, Clotilde, Bourin, Michael, Gulianello, Jonathan, Lippy, Susheel, Nara, Tarun Kumar, Maishal, Kamalraj, Thiyagarajan, Prasadrao, Jalagam, Sreenivasulu Naidu, Pattipati, Kumaran, Dandapani, Manoj, Dokania, Pradeep, Vattikundala, Vivek, Sharma, Saravanan, Elavazhagan, Manoj Kumar, Verma, Manish Lal, Das, Santosh, Wagh, Anand, Balakrishnan, Benjamin M, Johnson, Kenneth S, Santone, George, Thalody, Rex, Denton, Hariharan, Saminathan, Vinay K, Holenarsipur, Anoop, Kumar, Abhijith, Rao, Siva Prasad, Putlur, Sarat Kumar, Sarvasiddhi, Ganesh, Shankar, Justin V, Louis, Manjunath, Ramarao, Charles M, Conway, Yu-Wen, Li, Rick, Pieschl, Yuan, Tian, Yang, Hong, Jonathan, Ditta, Arvind, Mathur, Jianqing, Li, Daniel, Smith, Joseph, Pawluczyk, Dawn, Sun, Shiuhang, Yip, Dauh-Rurng, Wu, Muthalagu, Vetrichelvan, Anuradha, Gupta, Alan, Wilson, Suma, Gopinathan, Suman, Wason, Linda, Bristow, Charles F, Albright, Joanne J, Bronson, John E, Macor, and Carolyn D, Dzierba
- Subjects
Mice ,Spinal Cord ,Animals ,Brain ,Neuralgia ,Amines ,Protein Kinase Inhibitors ,Rats - Abstract
Recent mouse knockout studies identified adapter protein-2 associated kinase 1 (AAK1) as a viable target for treating neuropathic pain. Potent small-molecule inhibitors of AAK1 have been identified and show efficacy in various rodent pain models. (
- Published
- 2022
7. Environmental neurotoxicants and inflammasome activation in Parkinson's disease - A focus on the gut-brain axis
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Hariharan Saminathan, Richard D. Gordon, Zhen-Yi Andy Ou, and Aishwarya Mary Johnson
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Parkinson's disease ,biology ,business.industry ,Inflammasomes ,Gut–brain axis ,Inflammasome ,Cell Biology ,Disease ,Neuropathology ,Gut flora ,medicine.disease ,biology.organism_classification ,Biochemistry ,Immune system ,Synuclein ,medicine ,business ,Neuroscience ,medicine.drug - Abstract
Inflammasomes are multi-protein complexes expressed in immune cells that function as intracellular sensors of environmental, metabolic and cellular stress. Inflammasome activation in the brain, has been shown to drive neuropathology and disease progression by multiple mechanisms, making it one of the most attractive therapeutic targets for disease modification in Parkinson's Disease (PD). Extensive inflammasome activation is evident in the brains of people with PD at the sites of dopaminergic degeneration and synuclein aggregation. While substantial progress has been made on validating inflammasome activation as a therapeutic target for PD, the mechanisms by which inflammasome activation is triggered and sustained over the disease course remain poorly understood. A growing body of evidence point to environmental and occupational chemical exposures as possible triggers of inflammasome activation in PD. The involvement of the gastrointestinal system and gut microbiota in PD pathophysiology is beginning to be elucidated, especially the profound link between gut dysbiosis and immune activation. While large cohort studies confirmed specific changes in the gut microbiota in PD patients compared to age-matched healthy controls, recent research suggest that synuclein pathology could be initiated in the gastrointestinal tract. In this review, we present a summarized perspective on current understanding on inflammasome activation and the gut-brain-axis link during PD pathophysiology. We discuss multiple environmental toxicants that are implicated as the etiological agents in causing idiopathic PD and their mechanistic underpinnings during neuroinflammatory events. We additionally present future directions that needs to address the research questions related to the gut-microbiome-brain mechanisms in PD.
- Published
- 2021
8. Fyn kinase regulates misfolded α-synuclein uptake and NLRP3 inflammasome activation in microglia
- Author
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Huajun Jin, Hariharan Saminathan, Shivani Ghaisas, Manikandan Samidurai, Nikhil Panicker, Valina L. Dawson, Dharmin Rokad, Tae In Kam, Anumantha G. Kanthasamy, Monica R. Langley, Adhithiya Charli, Dilshan S. Harischandra, Arthi Kanthasamy, Olga Pletnikova, Matthew Neal, Souvarish Sarkar, Ted M. Dawson, and Vellareddy Anantharam
- Subjects
CD36 Antigens ,0301 basic medicine ,Protein Folding ,Inflammasomes ,CD36 ,Interleukin-1beta ,Priming (immunology) ,Proto-Oncogene Proteins c-fyn ,0302 clinical medicine ,Immunology and Allergy ,Gliosis ,Research Articles ,integumentary system ,Microglia ,biology ,Chemistry ,NF-kappa B ,Parkinson Disease ,Inflammasome ,Dependovirus ,Mitochondria ,3. Good health ,Cell biology ,Protein Kinase C-delta ,medicine.anatomical_structure ,alpha-Synuclein ,medicine.drug ,Immunology ,Models, Biological ,Article ,Protein Aggregates ,03 medical and health sciences ,Enzyme activator ,FYN ,NLR Family, Pyrin Domain-Containing 3 Protein ,medicine ,Animals ,Humans ,Scavenger receptor ,Neuroinflammation ,nervous system diseases ,Enzyme Activation ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,nervous system ,biology.protein ,Reactive Oxygen Species ,030217 neurology & neurosurgery - Abstract
Fyn kinase mediates aggregated α-synuclein (αSyn) uptake as well as αSyn-mediated proinflammatory signaling in microglia, leading to NLRP3 inflammasome activation and neuroinflammation in Parkinson’s disease., Persistent microglia-mediated neuroinflammation is a major pathophysiological contributor to the progression of Parkinson’s disease (PD), but the cell-signaling mechanisms governing chronic neuroinflammation are not well understood. Here, we show that Fyn kinase, in conjunction with the class B scavenger receptor CD36, regulates the microglial uptake of aggregated human α-synuclein (αSyn), which is the major component of PD-associated Lewy bodies. αSyn can effectively mediate LPS-independent priming and activation of the microglial NLRP3 inflammasome. Fyn kinase regulates both of these processes; it mediates PKCδ-dependent NF-κB–p65 nuclear translocation, leading to inflammasome priming, and facilitates αSyn import into microglia, contributing to the generation of mitochondrial reactive oxygen species and consequently to inflammasome activation. In vivo experiments using A53T and viral-αSyn overexpression mouse models as well as human PD neuropathological results further confirm the role of Fyn in NLRP3 inflammasome activation. Collectively, our study identifies a novel Fyn-mediated signaling mechanism that amplifies neuroinflammation in PD.
- Published
- 2019
9. Fyn Kinase-Mediated PKCδ Y311 Phosphorylation Induces Dopaminergic Degeneration in Cell Culture and Animal Models: Implications for the Identification of a New Pharmacological Target for Parkinson's Disease
- Author
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Anamitra Ghosh, Chunjuan Song, Huajun Jin, Hariharan Saminathan, Arthi Kanthasamy, Danhui Zhang, Vellareddy Anantharam, and Anumantha G. Kanthasamy
- Subjects
Programmed cell death ,endocrine system ,Neurite ,kinase ,Substantia nigra ,RM1-950 ,environment and public health ,chemistry.chemical_compound ,FYN ,Fyn ,medicine ,Pharmacology (medical) ,Neuroinflammation ,Original Research ,Pharmacology ,PKCδ ,Chemistry ,phosphorylation ,MPTP ,Neurodegeneration ,neurodegeneration ,hemic and immune systems ,medicine.disease ,Cell biology ,enzymes and coenzymes (carbohydrates) ,embryonic structures ,Phosphorylation ,Therapeutics. Pharmacology - Abstract
Oxidative stress, neuroinflammation and apoptosis are some of the key etiological factors responsible for dopamin(DA)ergic degeneration during Parkinson’s disease (PD), yet the downstream molecular mechanisms underlying neurodegeneration are largely unknown. Recently, a genome-wide association study revealed the FYN gene to be associated with PD, suggesting that Fyn kinase could be a pharmacological target for PD. In this study, we report that Fyn-mediated PKCδ tyrosine (Y311) phosphorylation is a key event preceding its proteolytic activation in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of Parkinsonism. MPP+/MPTP induced Fyn kinase activation in N27 DAergic neuronal cells and the mouse substantia nigra. PKCδ-Y311 phosphorylation by activated Fyn initiates the apoptotic caspase-signaling cascade during DAergic degeneration. Pharmacological attenuation of Fyn activity protected DAergic neurons from MPP+-induced degeneration in primary mesencephalic neuronal cultures. We further employed Fyn wild-type and Fyn knockout (KO) mice to confirm whether Fyn is a valid pharmacological target of DAergic neurodegeneration. Primary mesencephalic neurons from Fyn KO mice were greatly protected from MPP+-induced DAergic cell death, neurite loss and DA reuptake loss. Furthermore, Fyn KO mice were significantly protected from MPTP-induced PKCδ-Y311 phosphorylation, behavioral deficits and nigral DAergic degeneration. This study thus unveils a mechanism by which Fyn regulates PKCδ′s pro-apoptotic function and DAergic degeneration. Pharmacological inhibitors directed at Fyn activation could prove to be a novel therapeutic target in the delay or halting of selective DAergic degeneration during PD.
- Published
- 2020
10. Fyn kinase mediates pro-inflammatory response in a mouse model of endotoxemia: Relevance to translational research
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Vellareddy Anantharam, Anumantha G. Kanthasamy, Nikhil Panicker, Arthi Kanthasamy, Hariharan Saminathan, Jesse M. Hostetter, Adhithiya Charli, Jie Luo, Huajun Jin, and Richard D. Gordon
- Subjects
0301 basic medicine ,Lipopolysaccharides ,Male ,medicine.medical_specialty ,Mice, 129 Strain ,Lipopolysaccharide ,Anti-Inflammatory Agents ,Dasatinib ,Nitric Oxide Synthase Type II ,Apoptosis ,Systemic inflammation ,Proto-Oncogene Proteins c-fyn ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,FYN ,Internal medicine ,medicine ,Splenocyte ,Animals ,Src family kinase ,Protein Kinase Inhibitors ,Pharmacology ,Mice, Knockout ,biology ,Behavior, Animal ,Chemistry ,Endotoxemia ,Nitric oxide synthase ,Mice, Inbred C57BL ,Disease Models, Animal ,030104 developmental biology ,Endocrinology ,Liver ,biology.protein ,Cytokines ,Tumor necrosis factor alpha ,medicine.symptom ,Inflammation Mediators ,030217 neurology & neurosurgery ,Locomotion ,Spleen - Abstract
Systemic inflammation resulting from the release of pro-inflammatory cytokines and the chronic activation of the innate immune system remains a major cause of morbidity and mortality in the United States. After having demonstrated that Fyn, a Src family kinase, regulates microglial neuroinflammatory responses in cell culture and animal models of Parkinson's disease, we investigate here its role in modulating systemic inflammation using an endotoxic mouse model. Fyn knockout (KO) and their wild-type (WT) littermate mice were injected once intraperitoneally with either saline or 5 mg/kg lipopolysaccharide (LPS) and were killed 48 h later. LPS-induced mortality, endotoxic symptoms and hypothermia were significantly attenuated in Fyn KO, but not WT, mice. LPS reduced survival in Fyn WT mice to 49% compared to 84% in Fyn KO mice. Fyn KO mice were also protected from LPS-induced deficits in horizontal and vertical locomotor activities, total distance traveled and stereotypic movements. Surface body temperatures recorded at 24 h and 48 h post-LPS dropped significantly in Fyn WT, but not in KO, mice. Importantly, endotoxemia-associated changes to levels of the serum pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), splenocyte apoptosis and inducible nitric oxide synthase (iNOS) production in hepatocytes were also significantly attenuated in Fyn KO mice. Likewise, pharmacologically inhibiting Fyn with 10 mg/kg dasatinib (oral) significantly attenuated LPS-induced increases in plasma TNF-α and IL-6 protein levels and hepatic pro-IL-1β messenger ribonucleic acids (mRNAs). Collectively, these results indicate that genetic knockdown or pharmacological inhibition of Fyn dampens systemic inflammation, demonstrating for the first time that Fyn kinase plays a critical role in mediating the endotoxic inflammatory response.
- Published
- 2020
11. Fyn Kinase Regulates Microglial Neuroinflammatory Responses in Cell Culture and Animal Models of Parkinson's Disease
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Anumantha G. Kanthasamy, Jie Luo, Souvarish Sarkar, Nikhil Panicker, Vivek Lawana, Dilshan S. Harischandra, Hariharan Saminathan, Kavin Kanthasamy, Huajun Jin, Vellareddy Anantharam, Matthew Neal, Richard D. Gordon, and Arthi Kanthasamy
- Subjects
Lipopolysaccharides ,Tyrosine 3-Monooxygenase ,Biology ,Cell Fractionation ,Nitric Oxide ,Proto-Oncogene Proteins c-fyn ,environment and public health ,Proinflammatory cytokine ,Mice ,FYN ,medicine ,Animals ,Phosphorylation ,Kinase activity ,Oxidopamine ,Cells, Cultured ,Neuroinflammation ,Mice, Knockout ,Microglia ,Tumor Necrosis Factor-alpha ,General Neuroscience ,hemic and immune systems ,Parkinson Disease ,Articles ,Mice, Inbred C57BL ,enzymes and coenzymes (carbohydrates) ,Disease Models, Animal ,Protein Kinase C-delta ,medicine.anatomical_structure ,Mitogen-activated protein kinase ,embryonic structures ,biology.protein ,Cancer research ,Cytokines ,Encephalitis ,Tyrosine ,biological phenomena, cell phenomena, and immunity ,Tyrosine kinase - Abstract
Sustained neuroinflammation mediated by resident microglia is recognized as a key pathophysiological contributor to many neurodegenerative diseases, including Parkinson's disease (PD), but the key molecular signaling events regulating persistent microglial activation have yet to be clearly defined. In the present study, we examined the role of Fyn, a non-receptor tyrosine kinase, in microglial activation and neuroinflammatory mechanisms in cell culture and animal models of PD. The well-characterized inflammogens LPS and TNFα rapidly activated Fyn kinase in microglia. Immunocytochemical studies revealed that activated Fyn preferentially localized to the microglial plasma membrane periphery and the nucleus. Furthermore, activated Fyn phosphorylated PKCδ at tyrosine residue 311, contributing to an inflammogen-induced increase in its kinase activity. Notably, the Fyn-PKCδ signaling axis further activated the LPS- and TNFα-induced MAP kinase phosphorylation and activation of the NFκB pathway, implying that Fyn is a major upstream regulator of proinflammatory signaling. Functional studies in microglia isolated from wild-type (Fyn+/+) and Fyn knock-out (Fyn−/−) mice revealed that Fyn is required for proinflammatory responses, including cytokine release as well as iNOS activation. Interestingly, a prolonged inflammatory insult induced Fyn transcript and protein expression, indicating that Fyn is upregulated during chronic inflammatory conditions. Importantly, in vivo studies using MPTP, LPS, or 6-OHDA models revealed a greater attenuation of neuroinflammatory responses in Fyn−/− and PKCδ −/− mice compared with wild-type mice. Collectively, our data demonstrate that Fyn is a major upstream signaling mediator of microglial neuroinflammatory processes in PD. SIGNIFICANCE STATEMENT Parkinson's disease (PD) is a complex multifactorial disease characterized by the progressive loss of midbrain dopamine neurons. Sustained microglia-mediated neuroinflammation has been recognized as a major pathophysiological contributor to chronic degenerative processes in PD; however, the key molecular signaling mechanisms underlying microglial activation are not entirely clear. Herein, we identified a novel role for the non-receptor tyrosine kinase Fyn in regulating neuroinflammatory responses in microglia. Our data clearly suggest that the Fyn-PKCδ signaling axis acts as a major upstream signaling mediator of the sustained neuroinflammatory processes in cell culture and animal models of PD. Our finding has important clinical significance to PD because it identifies Fyn as a potential translational target for intervention of progressive neurodegenerative processes in PD.
- Published
- 2015
12. The Peptidyl-prolyl Isomerase Pin1 Up-regulation and Proapoptotic Function in Dopaminergic Neurons
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Vellareddy Anantharam, Hariharan Saminathan, Anumantha G. Kanthasamy, Arthi Kanthasamy, Gautam Sondarva, Anamitra Ghosh, Huajun Jin, Ziqing Qian, Dilshan S. Harischandra, and Ajay Rana
- Subjects
Peptidylprolyl isomerase ,MPTP ,1-Methyl-4-phenylpyridinium ,Dopaminergic ,Substantia nigra ,Cell Biology ,Biology ,Biochemistry ,Neuroprotection ,Cell biology ,chemistry.chemical_compound ,nervous system ,chemistry ,Dopamine ,PIN1 ,medicine ,Molecular Biology ,medicine.drug - Abstract
Parkinson disease (PD) is a chronic neurodegenerative disease characterized by a slow and progressive degeneration of dopaminergic neurons in substantia nigra. The pathophysiological mechanisms underlying PD remain unclear. Pin1, a major peptidyl-prolyl isomerase, has recently been associated with certain diseases. Notably, Ryo et al. (Ryo, A., Togo, T., Nakai, T., Hirai, A., Nishi, M., Yamaguchi, A., Suzuki, K., Hirayasu, Y., Kobayashi, H., Perrem, K., Liou, Y. C., and Aoki, I. (2006) J. Biol. Chem. 281, 4117–4125) implicated Pin1 in PD pathology. Therefore, we sought to systematically characterize the role of Pin1 in PD using cell culture and animal models. To our surprise we observed a dramatic up-regulation of Pin1 mRNA and protein levels in dopaminergic MN9D neuronal cells treated with the parkinsonian toxicant 1-methyl-4-phenylpyridinium (MPP+) as well as in the substantia nigra of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model. Notably, a marked expression of Pin1 was also observed in the substantia nigra of human PD brains along with a high co-localization of Pin1 within dopaminergic neurons. In functional studies, siRNA-mediated knockdown of Pin1 almost completely prevented MPP+-induced caspase-3 activation and DNA fragmentation, indicating that Pin1 plays a proapoptotic role. Interestingly, multiple pharmacological Pin1 inhibitors, including juglone, attenuated MPP+-induced Pin1 up-regulation, α-synuclein aggregation, caspase-3 activation, and cell death. Furthermore, juglone treatment in the MPTP mouse model of PD suppressed Pin1 levels and improved locomotor deficits, dopamine depletion, and nigral dopaminergic neuronal loss. Collectively, our findings demonstrate for the first time that Pin1 is up-regulated in PD and has a pathophysiological role in the nigrostriatal dopaminergic system and suggest that modulation of Pin1 levels may be a useful translational therapeutic strategy in PD. Background: Pin1 regulates several signaling proteins by isomerizing the cis/trans conformation of the Ser(P)-Pro peptide bond. Results: Pin1 is up-regulated in dopaminergic neurons in cell culture, animal models, and human PD brains. Pin1 inhibition protects dopaminergic neurons in PD models. Conclusion: Pin1 up-regulation plays a proapoptotic function in PD. Significance: Pin1 inhibition may be a viable translational strategy in PD.
- Published
- 2013
13. Fyn kinase regulates microglial neuroinflammatory responses in cell culture and animal models of Parkinson’s disease (1055.7)
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Hariharan Saminathan, Vellareddy Anantram, Kavin Kanthasamy, Nikhil Panicker, Anumantha G. Kanthasamy, Huajun Jin, and Arthi Kanthasamy
- Subjects
Chemokine ,Parkinson's disease ,Microglia ,Biology ,medicine.disease ,Biochemistry ,Proinflammatory cytokine ,Cell biology ,FYN ,medicine.anatomical_structure ,Immunology ,Genetics ,medicine ,biology.protein ,Phosphorylation ,Molecular Biology ,Tyrosine kinase ,Neuroinflammation ,Biotechnology - Abstract
Sustained neuroinflammation is recognized as a key pathophysiological contributor to many neurodegenerative diseases, including Parkinson’s disease (PD). Resident brain microglia mediate chronic neuroinflammation through the production of proinflammatory cytokines and chemokines. Identifying the key molecular signaling events perpetuating microglial activation could unravel novel mechanisms underlying glial-neuronal interactions that contribute to persistent inflammation and progressive neurodegeneration in PD. In the present study, we examined the role that Fyn, a non-receptor tyrosine kinase, plays in microglial activation in cell culture and animal models of PD. First, we show that the known inflammogen LPS (lipopolysaccharide) rapidly activated Fyn kinase, as measured by Fyn-Y416 phosphorylation and Fyn kinase assays in the BV2 microglial cell line as well as in primary microglia. Notably, immunocytochemical studies revealed that activated Fyn is preferentially localized to the microglial membrane per...
- Published
- 2014
14. Protein kinase D1 (PKD1) activation mediates a compensatory protective response during early stages of oxidative stress-induced neuronal degeneration
- Author
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Hariharan Saminathan, Arunkumar Asaithambi, Arthi Kanthasamy, Vellareddy Anantharam, and Anumantha G. Kanthasamy
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Programmed cell death ,Clinical Neurology ,Oxidative phosphorylation ,Biology ,lcsh:Geriatrics ,medicine.disease_cause ,urologic and male genital diseases ,Neuroprotection ,lcsh:RC346-429 ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,medicine ,Molecular Biology ,lcsh:Neurology. Diseases of the nervous system ,030304 developmental biology ,0303 health sciences ,Kinase ,female genital diseases and pregnancy complications ,Cell biology ,lcsh:RC952-954.6 ,Phosphorylation ,Neurology (clinical) ,Protein kinase D1 ,Signal transduction ,Neuroscience ,030217 neurology & neurosurgery ,Oxidative stress ,Research Article - Abstract
Background Oxidative stress is a key pathophysiological mechanism contributing to degenerative processes in many neurodegenerative diseases and therefore, unraveling molecular mechanisms underlying various stages of oxidative neuronal damage is critical to better understanding the diseases and developing new treatment modalities. We previously showed that protein kinase C delta (PKCδ) proteolytic activation during the late stages of oxidative stress is a key proapoptotic signaling mechanism that contributes to oxidative damage in Parkinson's disease (PD) models. The time course studies revealed that PKCδ activation precedes apoptotic cell death and that cells resisted early insults of oxidative damage, suggesting that some intrinsic compensatory response protects neurons from early oxidative insult. Therefore, the purpose of the present study was to characterize protective signaling pathways in dopaminergic neurons during early stages of oxidative stress. Results Herein, we identify that protein kinase D1 (PKD1) functions as a key anti-apoptotic kinase to protect neuronal cells against early stages of oxidative stress. Exposure of dopaminergic neuronal cells to H2O2 or 6-OHDA induced PKD1 activation loop (PKD1S744/748) phosphorylation long before induction of neuronal cell death. Blockade of PKCδ cleavage, PKCδ knockdown or overexpression of a cleavage-resistant PKCδ mutant effectively attenuated PKD1 activation, indicating that PKCδ proteolytic activation regulates PKD1 phosphorylation. Furthermore, the PKCδ catalytic fragment, but not the regulatory fragment, increased PKD1 activation, confirming PKCδ activity modulates PKD1 activation. We also identified that phosphorylation of S916 at the C-terminal is a preceding event required for PKD1 activation loop phosphorylation. Importantly, negative modulation of PKD1 by the RNAi knockdown or overexpression of PKD1S916A phospho-defective mutants augmented oxidative stress-induced apoptosis, while positive modulation of PKD1 by the overexpression of full length PKD1 or constitutively active PKD1 plasmids attenuated oxidative stress-induced apoptosis, suggesting an anti-apoptotic role for PKD1 during oxidative neuronal injury. Conclusion Collectively, our results demonstrate that PKCδ-dependent activation of PKD1 represents a novel intrinsic protective response in counteracting early stage oxidative damage in neuronal cells. Our results suggest that positive modulation of the PKD1-mediated compensatory protective mechanism against oxidative damage in dopaminergic neurons may provide novel neuroprotective strategies for treatment of PD.
- Published
- 2011
15. Environmental neurotoxic pesticide dieldrin activates a non receptor tyrosine kinase to promote PKCδ-mediated dopaminergic apoptosis in a dopaminergic neuronal cell model
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Hariharan Saminathan, Arunkumar Asaithambi, Vellareddy Anantharam, Anumantha G. Kanthasamy, and Arthi Kanthasamy
- Subjects
Dopamine ,Apoptosis ,Biology ,Mitogen-activated protein kinase kinase ,Toxicology ,Hazardous Substances ,Article ,MAP2K7 ,FYN ,TYK2 Kinase ,Animals ,ASK1 ,Pesticides ,Protein kinase A ,Dieldrin ,MAP kinase kinase kinase ,Cell Death ,General Neuroscience ,Dopaminergic Neurons ,Cyclin-dependent kinase 2 ,Rats ,Enzyme Activation ,Protein Kinase C-delta ,biology.protein ,Cancer research - Abstract
Oxidative stress and apoptosis are two key pathophysiological mechanisms underlying dopaminergic degeneration in Parkinson's disease (PD). Recently, we identified that proteolytic activation of protein kinase C-delta (PKCδ), a member of the novel PKC family, contributes to oxidative stress-induced dopaminergic degeneration and that phosphorylation of tyrosine residue 311 (tyr311) on PKCδ is a key event preceding the PKCδ proteolytic activation during oxidative damage. Herein, we report that a non-receptor tyrosine kinase Fyn is significantly expressed in a dopaminergic neuronal N27 cell model. Exposure of N27 cells to the dopaminergic toxicant dieldrin (60 μM) rapidly activated Fyn kinase, PKCδ-tyr311 phosphorylation and proteolytic cleavage. Fyn kinase activation precedes the caspase-3-mediated proteolytic activation of PKCδ. Pre-treatment with p60-tyrosine-specific kinase inhibitor (TSKI) almost completely attenuated dieldrin-induced phosphorylation of PKCδ-tyr311 and its proteolytic activation. Additionally, TSKI almost completely blocked dieldrin-induced apoptotic cell death. To further confirm Fyn's role in the pro-apoptotic function of PKCδ, we adopted the RNAi approach. siRNA-mediated knockdown of Fyn kinase also effectively attenuated dieldrin-induced phosphorylation of PKCδ-tyr311, caspase-3-mediated PKCδ proteolytic cleavage, and DNA fragmentation, suggesting that Fyn kinase regulates the pro-apoptotic function of PKCδ. Collectively, these results demonstrate for the first time that Fyn kinase is a pro-apoptotic kinase that regulates upstream signaling of the PKCδ-mediated apoptotic cell death pathway in neurotoxicity models of pesticide exposure.
- Published
- 2011
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