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Baudry M, Wang Y, Bi X, Luo YL, Wang Z, Kamal Z, Shirokov A, Sullivan E, Lagasca D, Khalil H, Lee G, Fosnaugh K, Bey P, Medi S, Coulter G. Identification and neuroprotective properties of NA-184, a calpain-2 inhibitor. Pharmacol Res Perspect 2024; 12:e1181. [PMID: 38429943 PMCID: PMC10907882 DOI: 10.1002/prp2.1181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/02/2024] [Accepted: 02/09/2024] [Indexed: 03/03/2024] Open
Abstract
Our laboratory has shown that calpain-2 activation in the brain following acute injury is directly related to neuronal damage and the long-term functional consequences of the injury, while calpain-1 activation is generally neuroprotective and calpain-1 deletion exacerbates neuronal injury. We have also shown that a relatively selective calpain-2 inhibitor, referred to as C2I, enhanced long-term potentiation and learning and memory, and provided neuroprotection in the controlled cortical impact (CCI) model of traumatic brain injury (TBI) in mice. Using molecular dynamic simulation and Site Identification by Ligand Competitive Saturation (SILCS) software, we generated about 130 analogs of C2I and tested them in a number of in vitro and in vivo assays. These led to the identification of two interesting compounds, NA-112 and NA-184. Further analyses indicated that NA-184, (S)-2-(3-benzylureido)-N-((R,S)-1-((3-chloro-2-methoxybenzyl)amino)-1,2-dioxopentan-3-yl)-4-methylpentanamide, selectively and dose-dependent inhibited calpain-2 activity without evident inhibition of calpain-1 at the tested concentrations in mouse brain tissues and human cell lines. Like NA-112, NA-184 inhibited TBI-induced calpain-2 activation and cell death in mice and rats, both male and females. Pharmacokinetic and pharmacodynamic analyses indicated that NA-184 exhibited properties, including stability in plasma and liver and blood-brain barrier permeability, that make it a good clinical candidate for the treatment of TBI.
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Affiliation(s)
- Michel Baudry
- Western University of Health SciencesPomonaCaliforniaUSA
- NeurAegis, IncIrvineCaliforniaUSA
| | - Yubin Wang
- Western University of Health SciencesPomonaCaliforniaUSA
| | - Xiaoning Bi
- Western University of Health SciencesPomonaCaliforniaUSA
| | - Yun Lyna Luo
- Western University of Health SciencesPomonaCaliforniaUSA
| | - Zhijun Wang
- Department of Clinical Pharmacy Practice, School of Pharmacy and Pharmaceutical SciencesUniversity of CaliforniaIrvineCaliforniaUSA
| | | | | | | | | | | | - Gary Lee
- Nanosyn, IncSanta ClaraCaliforniaUSA
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Baudry M, Bi X. Revisiting the calpain hypothesis of learning and memory 40 years later. Front Mol Neurosci 2024; 17:1337850. [PMID: 38361744 PMCID: PMC10867166 DOI: 10.3389/fnmol.2024.1337850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024] Open
Abstract
In 1984, Gary Lynch and Michel Baudry published in Science a novel biochemical hypothesis for learning and memory, in which they postulated that the calcium-dependent protease, calpain, played a critical role in regulating synaptic properties and the distribution of glutamate receptors, thereby participating in memory formation in hippocampus. Over the following 40 years, much work has been done to refine this hypothesis and to provide convincing arguments supporting what was viewed at the time as a simplistic view of synaptic biochemistry. We have now demonstrated that the two major calpain isoforms in the brain, calpain-1 and calpain-2, execute opposite functions in both synaptic plasticity/learning and memory and in neuroprotection/neurodegeneration. Thus, calpain-1 activation is required for triggering long-term potentiation (LTP) of synaptic transmission and learning of episodic memory, while calpain-2 activation limits the magnitude of LTP and the extent of learning. On the other hand, calpain-1 is neuroprotective while calpain-2 is neurodegenerative, and its prolonged activation following various types of brain insults leads to neurodegeneration. The signaling pathways responsible for these functions have been identified and involve local protein synthesis, cytoskeletal regulation, and regulation of glutamate receptors. Human families with mutations in calpain-1 have been reported to have impairment in motor and cognitive functions. Selective calpain-2 inhibitors have been synthesized and clinical studies to test their potential use to treat disorders associated with acute neuronal damage, such as traumatic brain injury, are being planned. This review will illustrate the long and difficult journey to validate a bold hypothesis.
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Affiliation(s)
- Michel Baudry
- Western University of Health Sciences, Pomona, CA, United States
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3
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Su W, Liu Y, Lam A, Hao X, Baudry M, Bi X. Contextual fear memory impairment in Angelman syndrome model mice is associated with altered transcriptional responses. Sci Rep 2023; 13:18647. [PMID: 37903805 PMCID: PMC10616231 DOI: 10.1038/s41598-023-45769-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 10/24/2023] [Indexed: 11/01/2023] Open
Abstract
Angelman syndrome (AS) is a rare neurogenetic disorder caused by UBE3A deficiency and characterized by severe developmental delay, cognitive impairment, and motor dysfunction. In the present study, we performed RNA-seq on hippocampal samples from both wildtype (WT) and AS male mice, with or without contextual fear memory recall. There were 281 recall-associated differentially expressed genes (DEGs) in WT mice and 268 DEGs in AS mice, with 129 shared by the two genotypes. Gene ontology analysis showed that extracellular matrix and stimulation-induced response genes were prominently enriched in recall-associated DEGs in WT mice, while nuclear acid metabolism and tissue development genes were highly enriched in those from AS mice. Further analyses showed that the 129 shared DEGs belonged to nuclear acid metabolism and tissue development genes. Unique recall DEGs in WT mice were enriched in biological processes critical for synaptic plasticity and learning and memory, including the extracellular matrix network clustered around fibronectin 1 and collagens. In contrast, AS-specific DEGs were not enriched in any known pathways. These results suggest that memory recall in AS mice, while altering the transcriptome, fails to recruit memory-associated transcriptional programs, which could be responsible for the memory impairment in AS mice.
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Affiliation(s)
- Wenyue Su
- College of Dental Medicine, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Yan Liu
- College of Dental Medicine, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Aileen Lam
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 701 E. 2nd St., Pomona, CA, 91766-1854, USA
| | - Xiaoning Hao
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 701 E. 2nd St., Pomona, CA, 91766-1854, USA
| | - Michel Baudry
- College of Dental Medicine, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, 701 E. 2nd St., Pomona, CA, 91766-1854, USA.
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Baudry M, Luo YL, Bi X. Calpain-2 Inhibitors as Therapy for Traumatic Brain Injury. Neurotherapeutics 2023; 20:1592-1602. [PMID: 37474874 PMCID: PMC10684478 DOI: 10.1007/s13311-023-01407-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/30/2023] [Indexed: 07/22/2023] Open
Abstract
While calpains have long been implicated in neurodegeneration, no calpain inhibitor has been developed for the treatment of neurodegeneration. This is partly due to the lack of understanding of the specific functions of most of the 15 members of the calpain family. Work from our laboratory over the last 5-10 years has revealed that calpain-1 and calpain-2, two of the major calpain isoforms in the brain, play opposite roles in both synaptic plasticity/learning and memory and neuroprotection/neurodegeneration. Thus, calpain-1 activation is required for triggering certain forms of synaptic plasticity and for learning some types of information and is neuroprotective. In contrast, calpain-2 activation limits the extent of synaptic plasticity and of learning and is neurodegenerative. These results have been validated with the use of calpain-1 knock-out mice and mice with a selective calpain-2 deletion in excitatory neurons of the forebrain. Through a medicinal chemistry campaign, we have identified a number of selective calpain-2 inhibitors and shown that these inhibitors do facilitate learning of certain tasks and are neuroprotective in a number of animal models of acute neurodegeneration. One of these inhibitors, NA-184, is currently being developed for the treatment of traumatic brain injury, and clinical trials are being planned.
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Affiliation(s)
- Michel Baudry
- CDM, Western University of Health Sciences, 309 E. 2nd St, Pomona, CA, 91766, USA.
| | - Yun Lyna Luo
- CoP, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Xiaoning Bi
- COMP, Western University of Health Sciences, Pomona, CA, 91766, USA
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Hao X, Sun J, Zhong L, Baudry M, Bi X. UBE3A deficiency-induced autophagy is associated with activation of AMPK-ULK1 and p53 pathways. Exp Neurol 2023; 363:114358. [PMID: 36849003 PMCID: PMC10073344 DOI: 10.1016/j.expneurol.2023.114358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 02/03/2023] [Accepted: 02/22/2023] [Indexed: 02/27/2023]
Abstract
Angelman Syndrome (AS) is a neurodevelopmental disorder caused by deficiency of the maternally expressed UBE3A gene. The UBE3A proteins functions both as an E3 ligase in the ubiquitin-proteasome system (UPS), and as a transcriptional co-activator for steroid hormone receptors. Here we investigated the effects of UBE3A deficiency on autophagy in the cerebellum of AS mice and in COS1 cells. Numbers and size of LC3- and LAMP2-immunopositive puncta were increased in cerebellar Purkinje cells of AS mice, as compared to wildtype mice. Western blot analysis showed an increase in the conversion of LC3I to LC3II in AS mice, as expected from increased autophagy. Levels of active AMPK and of one of its substrates, ULK1, a factor involved in autophagy initiation, were also increased. Colocalization of LC3 with LAMP2 was increased and p62 levels were decreased, indicating an increase in autophagy flux. UBE3A deficiency was also associated with reduced levels of phosphorylated p53 in the cytosol and increased levels in nuclei, which favors autophagy induction. UBE3A siRNA knockdown in COS-1 cells resulted in increased size and intensity of LC3-immunopositive puncta and increased the LC3 II/I ratio, as compared to control siRNA-treated cells, confirming the results found in the cerebellum of AS mice. These results indicate that UBE3A deficiency enhances autophagic activity through activation of the AMPK-ULK1 pathway and alterations in p53.
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Affiliation(s)
- Xiaoning Hao
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Li Zhong
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Michel Baudry
- College of Dental Medicine, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA.
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Baudry M. Meet the Editorial Board Member. Curr Neuropharmacol 2022. [DOI: 10.2174/1570159x2006220421103431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Michel Baudry
- University Professor
Western University of Health Sciences
309 E. 2nd St
Pomona, CA 91766
USA
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Sun J, Liu Y, Hao X, Lin W, Su W, Chiang E, Baudry M, Bi X. LAMTOR1 inhibition of TRPML1‐dependent lysosomal calcium release regulates dendritic lysosome trafficking and hippocampal neuronal function. EMBO J 2022; 41:e108119. [PMID: 35099830 PMCID: PMC8886530 DOI: 10.15252/embj.2021108119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 12/12/2021] [Accepted: 12/21/2021] [Indexed: 02/05/2023] Open
Abstract
Lysosomes function not only as degradatory compartments but also as dynamic intracellular calcium ion stores. The transient receptor potential mucolipin 1 (TRPML1) channel mediates lysosomal Ca2+ release, thereby participating in multiple cellular functions. The pentameric Ragulator complex, which plays a critical role in the activation of mTORC1, is also involved in lysosomal trafficking and is anchored to lysosomes through its LAMTOR1 subunit. Here, we report that the Ragulator restricts lysosomal trafficking in dendrites of hippocampal neurons via LAMTOR1‐mediated tonic inhibition of TRPML1 activity, independently of mTORC1. LAMTOR1 directly interacts with TRPML1 through its N‐terminal domain. Eliminating this inhibition in hippocampal neurons by LAMTOR1 deletion or by disrupting LAMTOR1‐TRPML1 binding increases TRPML1‐mediated Ca2+ release and facilitates dendritic lysosomal trafficking powered by dynein. LAMTOR1 deletion in the hippocampal CA1 region of adult mice results in alterations in synaptic plasticity, and in impaired object‐recognition memory and contextual fear conditioning, due to TRPML1 activation. Mechanistically, changes in synaptic plasticity are associated with increased GluA1 dephosphorylation by calcineurin and lysosomal degradation. Thus, LAMTOR1‐mediated inhibition of TRPML1 is critical for regulating dendritic lysosomal motility, synaptic plasticity, and learning.
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Affiliation(s)
- Jiandong Sun
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona CA USA
| | - Yan Liu
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Xiaoning Hao
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona CA USA
| | - Weiju Lin
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Wenyue Su
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Emerald Chiang
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences Western University of Health Sciences Pomona CA USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona CA USA
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Wang Y, Brazdzionis J, Dong F, Patchana T, Ghanchi H, Podkovik S, Wiginton JG, Marino M, Duong J, Wacker M, Miulli DE, Neeki M, Bi X, Baudry M. P13BP, a Calpain-2-Mediated Breakdown Product of PTPN13, Is a Novel Blood Biomarker for Traumatic Brain Injury. J Neurotrauma 2021; 38:3077-3085. [PMID: 34498916 DOI: 10.1089/neu.2021.0229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Biomarkers play an increasing role in medicinal biology. They are used for diagnosis, management, drug target identification, drug responses, and disease prognosis. We have discovered that calpain-1 and calpain-2 play opposite functions in neurodegeneration, with calpain-1 activation being neuroprotective, while prolonged calpain-2 activation is neurodegenerative. This notion has been validated in several mouse models of acute neuronal injury, in particular in mouse models of traumatic brain injury (TBI) and repeated concussions. We have identified a selective substrate of calpain-2, the tyrosine phosphatase, PTPN13, which is cleaved in brain after TBI. One of the fragments generated by calpain-2, referred to as P13BP, is also found in the blood after TBI both in mice and humans. In humans, P13BP blood levels are significantly correlated with the severity of TBI, as measured by Glasgow Coma Scale scores and loss of consciousness. The results indicate that P13BP represents a novel blood biomarker for TBI.
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Affiliation(s)
- Yubin Wang
- Western University of Health Sciences, Pomona Valley, California, USA
| | - James Brazdzionis
- Riverside University Health System Medical Center, Moreno Valley, California, USA
| | - Fanglong Dong
- Western University of Health Sciences, Pomona Valley, California, USA
| | - Tye Patchana
- Riverside University Health System Medical Center, Moreno Valley, California, USA
| | - Hammad Ghanchi
- Riverside University Health System Medical Center, Moreno Valley, California, USA
| | - Stacey Podkovik
- Riverside University Health System Medical Center, Moreno Valley, California, USA
| | - James G Wiginton
- Riverside University Health System Medical Center, Moreno Valley, California, USA
| | - Maxwell Marino
- Riverside University Health System Medical Center, Moreno Valley, California, USA
| | - Jason Duong
- Arrowhead Regional Medical Center, Colton, California, USA
| | | | - Dan E Miulli
- Arrowhead Regional Medical Center, Colton, California, USA
| | - Michael Neeki
- Arrowhead Regional Medical Center, Colton, California, USA
| | - Xiaoning Bi
- Western University of Health Sciences, Pomona Valley, California, USA
| | - Michel Baudry
- Western University of Health Sciences, Pomona Valley, California, USA
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Abstract
While calpains have been implicated in neurogenesis for a long time, there is still little information regarding the specific contributions of various isoforms in this process. We took advantage of the availability of mutant mice with complete deletion of calpain-1 to analyze its contribution to neurogenesis. We first used the incorporation of BrdU in newly-generated cells in the subgranular zone of the dentate gyrus to determine the role of calpain-1 deletion in neuronal proliferation. Our results showed that the lack of calpain-1 decreased the rate of cell proliferation in adult hippocampus. As previously shown, it also decreased the long-term survival of newly-generated neurons. We also used data from previously reported RNA and miRNA sequencing analyses to identify differentially expressed genes in brain of calpain-1 knock-out mice related to cell division, cell migration, cell proliferation and cell survival. A number of differentially expressed genes were identified, which could play a significant role in the changes in neurogenesis in calpain-1 knock out mice. The results provide new information regarding the role of calpain-1 in neurogenesis and have implications for better understanding the pathologies associated with calpain-1 mutations in humans.
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Affiliation(s)
- Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Wenyue Su
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Jeffrey Seinfeld
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
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Affiliation(s)
- Michel Baudry
- University Professor Western University of Health Sciences 309 E. 2nd St Pomona, CA 91766,United States
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Su W, Bi X, Wang Y, Baudry M. Changes in neurodegeneration-related miRNAs in brains from CAPN1 -/- mice. BBA Adv 2021; 1. [PMID: 34286311 PMCID: PMC8289118 DOI: 10.1016/j.bbadva.2021.100004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Calpain-1 knock-out (KO) mice exhibit enhanced susceptibility to neurodegeneration due to the lack of the neuroprotective function of calpain-1. Dicer has been shown to play a fundamental role in the biogenesis of most miRNAs. Here, we identified 45 differentially expressed miRNAs (DE miRNAs) in the brain of calpain-1 KO mice, as compared to wild-type mice. In particular, among all the DE miRNAs, 7 neurodegeneration-related miRNAs were found to be down-regulated in calpain-1 KO mice. We also found that Dicer is cleaved by calpain-1 in mouse brain, which generates an active fragment of Dicer with RNAse III activity and increases miRNA formation. Levels of active Dicer were reduced in brain homogenates from calpain-1 KO mice and incubation with calpain-1 and calcium restored Dicer activity and miRNA expression. Our results indicate that calpain-1 deletion results in decreased levels of active Dicer and changes in neurodegenerative-related miRNAs. These findings could account for some of the pathological changes found in brain of various mammals, including humans, with calpain-1 mutations or down-regulation.
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Affiliation(s)
- Wenyue Su
- Graduate College of Biomedical Sciences, United States
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Yubin Wang
- Graduate College of Biomedical Sciences, United States
| | - Michel Baudry
- Graduate College of Biomedical Sciences, United States
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Wang Y, Liu Y, Bi X, Baudry M. Calpain-1 and Calpain-2 in the Brain: New Evidence for a Critical Role of Calpain-2 in Neuronal Death. Cells 2020; 9:cells9122698. [PMID: 33339205 PMCID: PMC7765587 DOI: 10.3390/cells9122698] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/08/2020] [Accepted: 12/14/2020] [Indexed: 01/24/2023] Open
Abstract
Calpains are a family of soluble calcium-dependent proteases that are involved in multiple regulatory pathways. Our laboratory has focused on the understanding of the functions of two ubiquitous calpain isoforms, calpain-1 and calpain-2, in the brain. Results obtained over the last 30 years led to the remarkable conclusion that these two calpain isoforms exhibit opposite functions in the brain. Calpain-1 activation is required for certain forms of synaptic plasticity and corresponding types of learning and memory, while calpain-2 activation limits the extent of plasticity and learning. Calpain-1 is neuroprotective both during postnatal development and in adulthood, while calpain-2 is neurodegenerative. Several key protein targets participating in these opposite functions have been identified and linked to known pathways involved in synaptic plasticity and neuroprotection/neurodegeneration. We have proposed the hypothesis that the existence of different PDZ (PSD-95, DLG and ZO-1) binding domains in the C-terminal of calpain-1 and calpain-2 is responsible for their association with different signaling pathways and thereby their different functions. Results with calpain-2 knock-out mice or with mice treated with a selective calpain-2 inhibitor indicate that calpain-2 is a potential therapeutic target in various forms of neurodegeneration, including traumatic brain injury and repeated concussions.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (Y.W.); (Y.L.)
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (Y.W.); (Y.L.)
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA;
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA; (Y.W.); (Y.L.)
- Correspondence: ; Tel.: +1-909-469-8271
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Sun J, Liu Y, Baudry M, Bi X. SK2 channel regulation of neuronal excitability, synaptic transmission, and brain rhythmic activity in health and diseases. Biochim Biophys Acta Mol Cell Res 2020; 1867:118834. [PMID: 32860835 PMCID: PMC7541745 DOI: 10.1016/j.bbamcr.2020.118834] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 08/13/2020] [Accepted: 08/19/2020] [Indexed: 11/20/2022]
Abstract
Small conductance calcium-activated potassium channels (SKs) are solely activated by intracellular Ca2+ and their activation leads to potassium efflux, thereby repolarizing/hyperpolarizing membrane potential. Thus, these channels play a critical role in synaptic transmission, and consequently in information transmission along the neuronal circuits expressing them. SKs are widely but not homogeneously distributed in the central nervous system (CNS). Activation of SKs requires submicromolar cytoplasmic Ca2+ concentrations, which are reached following either Ca2+ release from intracellular Ca2+ stores or influx through Ca2+ permeable membrane channels. Both Ca2+ sensitivity and synaptic levels of SKs are regulated by protein kinases and phosphatases, and degradation pathways. SKs in turn control the activity of multiple Ca2+ channels. They are therefore critically involved in coordinating diverse Ca2+ signaling pathways and controlling Ca2+ signal amplitude and duration. This review highlights recent advances in our understanding of the regulation of SK2 channels and of their roles in normal brain functions, including synaptic plasticity, learning and memory, and rhythmic activities. It will also discuss how alterations in their expression and regulation might contribute to various brain disorders such as Angelman Syndrome, Alzheimer's disease and Parkinson's disease.
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Affiliation(s)
- Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Yan Liu
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Michel Baudry
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States of America; Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States of America.
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Wang Y, Liu Y, Yahya E, Quach D, Bi X, Baudry M. Calpain-2 activation in mouse hippocampus plays a critical role in seizure-induced neuropathology. Neurobiol Dis 2020; 147:105149. [PMID: 33132163 DOI: 10.1016/j.nbd.2020.105149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 10/23/2022] Open
Abstract
Calpain has been proposed to play a critical role in the development of epilepsy. Here we used conditional calpain-2 knock-out (C2CKO) mice in a C57/Bl6 background and a selective calpain-2 inhibitor to analyze the role of calpain-2 in epilepsy. Neurodegeneration was evident in various hippocampal subfields, in particular in mossy cells in the hilus of the dentate gyrus (DG) in C57/Bl6 mice 7 days after kainic acid (KA)-induced seizures. Calpain-2 activation was still observed in mossy cells 7 days after seizures. Calpain activation, astroglial and microglial activation, neurodegeneration, and cognitive impairment were absent in C2CKO mice and in C57/Bl6 mice treated with a selective calpain-2 inhibitor for 7 days after seizure initiation. Levels of the potassium chloride cotransporter 2 (KCC2) were decreased in mossy cells 7 days after seizures and this decrease was prevented by calpain-2 deletion or selective inhibition. Our results indicate that prolonged calpain-2 activation plays a critical role in neuropathology following seizures. A selective calpain-2 inhibitor could represent a therapeutic treatment for seizure-induced neuropathology.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Emad Yahya
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Diana Quach
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA.
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15
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Wang Y, Liu Y, Nham A, Sherbaf A, Quach D, Yahya E, Ranburger D, Bi X, Baudry M. Calpain-2 as a therapeutic target in repeated concussion-induced neuropathy and behavioral impairment. Sci Adv 2020; 6:6/27/eaba5547. [PMID: 32937436 PMCID: PMC7458466 DOI: 10.1126/sciadv.aba5547] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/19/2020] [Indexed: 06/11/2023]
Abstract
Repeated concussion represents a serious health problem as it can result in various brain pathologies, ranging from minor focal tissue injury to severe chronic traumatic encephalopathy. The calcium-dependent protease, calpain, participates in the development of neurodegeneration following concussion, but there is no information regarding the relative contribution of calpain-1 and calpain-2, the major calpain isoforms in the brain. We used a mouse model of repeated concussions, which reproduces most of the behavioral and neuropathological features of the human condition, to address this issue. Deletion of calpain-2 or treatment with a selective calpain-2 inhibitor for 2 weeks prevented most of these neuropathological features. Changes in TAR DNA binding protein 43 (TDP-43) subcellular localization similar to those found in human amyotrophic lateral sclerosis and frontotemporal dementia were also prevented by deletion of calpain-2 or treatment with calpain-2 inhibitor. Our results indicate that a selective calpain-2 inhibitor represents a therapeutic approach for concussion.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Amy Nham
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Arash Sherbaf
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Diana Quach
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Emad Yahya
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Davis Ranburger
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA.
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Su W, Zhou Q, Wang Y, Chishti A, Li QQ, Dayal S, Shiehzadegan S, Cheng A, Moore C, Bi X, Baudry M. Deletion of the Capn1 Gene Results in Alterations in Signaling Pathways Related to Alzheimer's Disease, Protein Quality Control and Synaptic Plasticity in Mouse Brain. Front Genet 2020; 11:334. [PMID: 32328086 PMCID: PMC7161415 DOI: 10.3389/fgene.2020.00334] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 03/20/2020] [Indexed: 12/24/2022] Open
Abstract
Calpains represent a family of calcium-dependent proteases participating in a multitude of functions under physiological or pathological conditions. Calpain-1 is one of the most studied members of the family, is ubiquitously distributed in organs and tissues, and has been shown to be involved in synaptic plasticity and neuroprotection in mammalian brain. Calpain-1 deletion results in a number of phenotypic alterations. While some of these alterations can be explained by the acute functions of calpain-1, the present study was directed at studying alterations in gene expression that could also account for these phenotypic modifications. RNA-seq analysis identified 354 differentially expressed genes (DEGs) in brain of calpain-1 knock-out mice, as compared to their wild-type strain. Most DEGs were classified in 10 KEGG pathways, with the highest representations in Protein Processing in Endoplasmic Reticulum, MAP kinase and Alzheimer's disease pathways. Most DEGs were down-regulated and validation of a number of these genes indicated a corresponding decreased expression of their encoded proteins. The results indicate that calpain-1 is involved in the regulation of a significant number of genes affecting multiple brain functions. They also indicate that mutations in calpain-1 are likely to be involved in a number of brain disorders.
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Affiliation(s)
- Wenyue Su
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Qian Zhou
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
| | - Athar Chishti
- Sackler School of Biomedical Sciences, Tufts University, Boston, MA, United States
| | - Qingshun Q. Li
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Sujay Dayal
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
| | - Shayan Shiehzadegan
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
| | - Ariel Cheng
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
| | - Clare Moore
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, United States
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States
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Abstract
Cognitive psychologists have often discussed the idea that when Proust used in his books the concept of involuntary memories, which could be retrieved by an odor or a taste, he was in fact predating the notion of modern episodic memory. Since the publication of his famous "In Search of Lost Time", considerable progress has been made on our understanding of various types of memory and of the mechanisms involved in different brain circuits and synapses responsible for their long-term storage. This review will focus on the role of hippocampus in episodic memory, including its role in encoding time and various elements of episodes, in particular olfactory information. Our conclusion is that Proust did indeed predict the existence of episodic memory, although he did not realize that, in addition to remembering things past, memory is also used to predict the future.
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Affiliation(s)
- Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States.
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18
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Abstract
While the calpain system has now been discovered for over 50 years, there is still a paucity of information regard-ing the organization and functions of the signaling pathways regulated by these proteases, although calpains play critical roles in many cell functions. Moreover, calpain overactivation has been shown to be involved in numerous diseases. Among the 15 calpain isoforms identified, calpain-1 (aka µ-calpain) and calpain-2 (aka m-calpain) are ubiquitously distributed in most tissues and organs, including the brain. We have recently proposed that calpain-1 and calpain-2 play opposite functions in the brain, with calpain-1 activation being required for triggering synaptic plasticity and neuroprotection (Dr. Jekill), and calpain-2 limiting the extent of plasticity and being neurodegenerative (Mr. Hyde). Calpain-mediated cleavage has been ob-served in cytoskeleton proteins, membrane-associated proteins, receptors/channels, scaffolding/anchoring proteins, and pro-tein kinases and phosphatases. This review will focus on the signaling pathways related to local protein synthesis, cytoskele-ton regulation and neuronal survival/death regulated by calpain-1 and calpain-2, in an attempt to explain the origin of the op-posite functions of these 2 calpain isoforms. This will be followed by a discussion of the potential therapeutic applications of selective regulators of these 2 calpain isoforms.
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Affiliation(s)
- Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States
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19
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Affiliation(s)
- Jiandong Sun
- Western University of Health Sciences, Pomona, CA, USA
| | - Michel Baudry
- Western University of Health Sciences, Pomona, CA, USA
| | - Xiaoning Bi
- Western University of Health Sciences, Pomona, CA, USA
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20
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Wang Y, Baudry M. Acute Cerebellar Slice Preparation Using a Tissue Chopper. Bio Protoc 2019; 9:e3187. [PMID: 33654989 DOI: 10.21769/bioprotoc.3187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/31/2019] [Accepted: 02/15/2019] [Indexed: 11/02/2022] Open
Abstract
Acute cerebellar slices are widely used among neuroscientists to study the properties of excitatory and inhibitory synaptic transmission as well as intracellular signaling pathways involved in their regulation in cerebellum. The cerebellar cortex presents a well-organized circuitry, and several neuronal pathways can be stimulated and recorded reliably in acute cerebellar slices. A widely used acute cerebellar slice preparation technique was adapted from Edwards' thin slice preparation method published in 1989 ( Edwards et al., 1989 ). Most of the acute cerebellar slice preparation techniques use a vibrating microtome for slicing freshly dissected cerebellum from various animal species. Here we introduce a simpler method, which uses a tissue chopper to quickly prepare acute sagittal cerebellar slices from rodents. Cerebellum is dissected from the whole brain and sliced with a tissue chopper into 200-400 µm thick slices. Slices are allowed to recover in oxygenated aCSF at 37 °C for 1-2 h. Slices can then be used for electrophysiology or other types of experimentation. This method can be used to prepare cerebellar slices from mouse or rat aged from postnatal day 7 to 2 years. The preparation is faster and easier than other methods and provides a more versatile diversity of applications.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
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21
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Heysieattalab S, Lee KH, Liu Y, Wang Y, Foy MR, Bi X, Baudry M. Impaired cerebellar plasticity and eye-blink conditioning in calpain-1 knock-out mice. Neurobiol Learn Mem 2019; 170:106995. [PMID: 30735788 DOI: 10.1016/j.nlm.2019.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/14/2019] [Accepted: 02/02/2019] [Indexed: 11/28/2022]
Abstract
Calpain-1 and calpain-2 are involved in the regulation of several signaling pathways and neuronal functions in the brain. Our recent studies indicate that calpain-1 is required for hippocampal synaptic plasticity, including long-term depression (LTD) and long-term potentiation (LTP) in field CA1. However, little is known regarding the contributions of calpain-1 to cerebellar synaptic plasticity. Low frequency stimulation (LFS, 5 Hz, 5 min)-induced LTP at parallel fibers to Purkinje cell synapses was markedly impaired in cerebellar slices from calpain-1 knock-out (KO) mice. Application of a selective calpain-2 inhibitor enhanced LFS-induced LTP in both wild-type (WT) and calpain-1 KO mice. Three protocols were used to induce LTD at these synapses: LFS (1 Hz, 15 min), perfusion with high potassium and glutamate (K-Glu) or dihydroxyphenylglycine (DHPG), a mGluR1 agonist. All three forms of LTD were impaired in calpain-1 KO mice. DHPG application stimulated calpain-1 but not calpain-2 in cerebellar slices, and DHPG-induced LTD impairment was reversed by application of a protein phosphatase 2A (PP2A) inhibitor, okadaic acid. As in hippocampus, BDNF induced calpain-1 activation and PH domain and Leucine-rich repeat Protein Phosphatase 1/suprachiasmatic nucleus oscillatory protein (PHLPP1/SCOP) degradation followed by extracellular signal-regulated kinase (ERK) activation, as well as calpain-2 activation leading to degradation of phosphatase and tensin homolog deleted on chromosome ten (PTEN) in cerebellar slices. The role of calpain-1 in associative learning was evaluated in the delay eyeblink conditioning (EBC). Calpain-1 KO mice exhibited significant learning impairment in EBC during the first 2 days of acquisition training. However, after 5 days of training, the percentage of conditioned responses (CRs) between calpain-1 KO and WT mice was identical. Both calpain-1 KO and WT mice exhibited typical extinction patterns. Our results indicate that calpain-1 plays critical roles in multiple forms of synaptic plasticity and associative learning in both hippocampus and cerebellum.
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Affiliation(s)
- Soomaayeh Heysieattalab
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States; Division of Cognitive Neuroscience, University of Tabriz, Tabriz, Iran
| | - Ka-Hung Lee
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Michael R Foy
- Department of Psychology, Loyola Marymount University, Los Angeles, CA 90045, United States
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, United States
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, United States.
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Sun J, Liu Y, Jia Y, Hao X, Lin WJ, Tran J, Lynch G, Baudry M, Bi X. UBE3A-mediated p18/LAMTOR1 ubiquitination and degradation regulate mTORC1 activity and synaptic plasticity. eLife 2018; 7:37993. [PMID: 30020076 PMCID: PMC6063731 DOI: 10.7554/elife.37993] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/17/2018] [Indexed: 01/04/2023] Open
Abstract
Accumulating evidence indicates that the lysosomal Ragulator complex is essential for full activation of the mechanistic target of rapamycin complex 1 (mTORC1). Abnormal mTORC1 activation has been implicated in several developmental neurological disorders, including Angelman syndrome (AS), which is caused by maternal deficiency of the ubiquitin E3 ligase UBE3A. Here we report that Ube3a regulates mTORC1 signaling by targeting p18, a subunit of the Ragulator. Ube3a ubiquinates p18, resulting in its proteasomal degradation, and Ube3a deficiency in the hippocampus of AS mice induces increased lysosomal localization of p18 and other members of the Ragulator-Rag complex, and increased mTORC1 activity. p18 knockdown in hippocampal CA1 neurons of AS mice reduces elevated mTORC1 activity and improves dendritic spine maturation, long-term potentiation (LTP), as well as learning performance. Our results indicate that Ube3a-mediated regulation of p18 and subsequent mTORC1 signaling is critical for typical synaptic plasticity, dendritic spine development, and learning and memory.
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Affiliation(s)
- Jiandong Sun
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, United States
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, United States
| | - Yousheng Jia
- Department of Psychiatry, University of California, Irvine, United States
| | - Xiaoning Hao
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, United States
| | - Wei Ju Lin
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, United States
| | - Jennifer Tran
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, United States
| | - Gary Lynch
- Department of Psychiatry, University of California, Irvine, United States
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, United States
| | - Xiaoning Bi
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, United States
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23
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Abstract
INTRODUCTION Calpains represent a family of neutral, calcium-dependent proteases, which modify the function of their target proteins by partial truncation. These proteases have been implicated in numerous cell functions, including cell division, proliferation, migration, and death. In the CNS, where calpain-1 and calpain-2 are the main calpain isoforms, their activation has been linked to synaptic plasticity as well as to neurodegeneration. This review will focus on the role of calpain-2 in acute neuronal injury and discuss the possibility of developing selective calpain-2 inhibitors for therapeutic purposes. Areas covered: This review covers the literature showing how calpain-2 is implicated in neuronal death in a number of pathological conditions. The possibility of developing new selective calpain-2 inhibitors for treating these conditions is discussed. Expert opinion: As evidence accumulates that calpain-2 activation participates in acute neuronal injury, there is interest in developing therapeutic approaches using selective calpain-2 inhibitors. Recent data indicate the potential use of such inhibitors in various pathologies associated with acute neuronal death. The possibility of extending the use of such inhibitors to more chronic forms of neurodegeneration is discussed.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, COMP Western University of Health Sciences 309 E. 2 St., Pomona, CA 91766
| | - Xiaoning Bi
- Department of Basic Science, COMP Western University of Health Sciences 309 E. 2 St., Pomona, CA 91766
| | - Michel Baudry
- Graduate College of Biomedical Sciences, COMP Western University of Health Sciences 309 E. 2 St., Pomona, CA 91766
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24
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Wang Y, Liu Y, Lopez D, Lee M, Dayal S, Hurtado A, Bi X, Baudry M. Protection against TBI-Induced Neuronal Death with Post-Treatment with a Selective Calpain-2 Inhibitor in Mice. J Neurotrauma 2018; 35:105-117. [PMID: 28594313 PMCID: PMC5757088 DOI: 10.1089/neu.2017.5024] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Traumatic Brain Injury (TBI) is a major cause of death and disability worldwide. The calcium-dependent protease, calpain, has been shown to be involved in TBI-induced neuronal death. However, whereas various calpain inhibitors have been tested in several animal models of TBI, there has not been any clinical trial testing the efficacy of calpain inhibitors in human TBI. One important reason for this could be the lack of knowledge regarding the differential functions of the two major calpain isoforms in the brain, calpain-1 and calpain-2. In this study, we used the controlled cortical impact (CCI) model in mice to test the roles of calpain-1 and calpain-2 in TBI-induced neuronal death. Immunohistochemistry (IHC) with calpain activity markers performed at different time-points after CCI in wild-type and calpain-1 knock-out (KO) mice showed that calpain-1 was activated early in cortical areas surrounding the impact, within 0-8 h after CCI, whereas calpain-2 activation was delayed and was predominant during 8-72 h after CCI. Calpain-1 KO enhanced cell death, whereas calpain-2 activity correlated with the extent of cell death, suggesting that calpain-1 activation suppresses and calpain-2 activation promotes cell death following TBI. Systemic injection(s) of a calpain-2 selective inhibitor, NA101, at 1 h or 4 h after CCI significantly reduced calpain-2 activity and cell death around the impact site, reduced the lesion volume, and promoted motor and learning function recovery after TBI. Our data indicate that calpain-1 activity is neuroprotective and calpain-2 activity is neurodegenerative after TBI, and that a selective calpain-2 inhibitor can reduce TBI-induced cell death.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California
| | - Dulce Lopez
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California
| | - Moses Lee
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California
| | | | - Alexander Hurtado
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California
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25
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Chatterjee P, Botello-Smith WM, Zhang H, Qian L, Alsamarah A, Kent D, Lacroix JJ, Baudry M, Luo Y. Can Relative Binding Free Energy Predict Selectivity of Reversible Covalent Inhibitors? J Am Chem Soc 2017; 139:17945-17952. [PMID: 29124934 PMCID: PMC5729052 DOI: 10.1021/jacs.7b08938] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Reversible covalent inhibitors have many clinical advantages over noncovalent or irreversible covalent drugs. However, apart from selecting a warhead, substantial efforts in design and synthesis are needed to optimize noncovalent interactions to improve target-selective binding. Computational prediction of binding affinity for reversible covalent inhibitors presents a unique challenge since the binding process consists of multiple steps, which are not necessarily independent of each other. In this study, we lay out the relation between relative binding free energy and the overall reversible covalent binding affinity using a two-state binding model. To prove the concept, we employed free energy perturbation (FEP) coupled with λ-exchange molecular dynamics method to calculate the binding free energy of a series of α-ketoamide analogues relative to a common warhead scaffold, in both noncovalent and covalent binding states, and for two highly homologous proteases, calpain-1 and calpain-2. We conclude that covalent binding state alone, in general, can be used to predict reversible covalent binding selectivity. However, exceptions may exist. Therefore, we also discuss the conditions under which the noncovalent binding step is no longer negligible and propose to combine the relative FEP calculations with a single QM/MM calculation of warhead to predict the binding affinity and binding kinetics. Our FEP calculations also revealed that covalent and noncovalent binding states of an inhibitor do not necessarily exhibit the same selectivity. Thus, investigating both binding states, as well as the kinetics will provide extremely useful information for optimizing reversible covalent inhibitors.
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Affiliation(s)
- Payal Chatterjee
- College of Pharmacy, Western University of Health Sciences , Pomona, California 91766, United States
| | - Wesley M Botello-Smith
- College of Pharmacy, Western University of Health Sciences , Pomona, California 91766, United States
| | - Han Zhang
- College of Pharmacy, Western University of Health Sciences , Pomona, California 91766, United States
| | - Li Qian
- College of Pharmacy, Western University of Health Sciences , Pomona, California 91766, United States
| | - Abdelaziz Alsamarah
- College of Pharmacy, Western University of Health Sciences , Pomona, California 91766, United States
| | - David Kent
- College of Pharmacy, Western University of Health Sciences , Pomona, California 91766, United States
| | - Jerome J Lacroix
- Graduate College of Biomedical Sciences, Western University of Health Sciences , Pomona, California 91766, United States
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences , Pomona, California 91766, United States
| | - Yun Luo
- College of Pharmacy, Western University of Health Sciences , Pomona, California 91766, United States
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26
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Wang Y, Hall RA, Lee M, Kamgar-Parsi A, Bi X, Baudry M. The tyrosine phosphatase PTPN13/FAP-1 links calpain-2, TBI and tau tyrosine phosphorylation. Sci Rep 2017; 7:11771. [PMID: 28924170 PMCID: PMC5603515 DOI: 10.1038/s41598-017-12236-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 09/06/2017] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) increases the risk of Alzheimer's disease (AD). Calpain activation and tau hyperphosphorylation have been implicated in both TBI and AD. However, the link between calpain and tau phosphorylation has not been fully identified. We recently discovered that the two major calpain isoforms in the brain, calpain-1 and calpain-2, play opposite functions in synaptic plasticity and neuronal survival/death, which may be related to their different C-terminal PDZ binding motifs. Here, we identify the tyrosine phosphatase PTPN13 as a key PDZ binding partner of calpain-2. PTPN13 is cleaved by calpain-2, which inactivates its phosphatase activity and generates stable breakdown products (P13BPs). We also found that PTPN13 dephosphorylates and inhibits c-Abl. Following TBI, calpain-2 activation cleaved PTPN13, activated c-Abl and triggered tau tyrosine phosphorylation. The activation of this pathway was responsible for the accumulation of tau oligomers after TBI, as post-TBI injection of a calpain-2 selective inhibitor inhibited c-Abl activation and tau oligomer accumulation. Thus, the calpain-2-PTPN13-c-Abl pathway provides a direct link between calpain-2 activation and abnormal tau aggregation, which may promote tangle formation and accelerate the development of AD pathology after repeated concussions or TBI. This study suggests that P13BPs could be potential biomarkers to diagnose mTBI or AD.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Randy A Hall
- Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Moses Lee
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Andysheh Kamgar-Parsi
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, 91766, USA.
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Keller A, Ambert N, Legendre A, Bedez M, Bouteiller JM, Bischoff S, Baudry M, Moussaoui S. Impact of synaptic localization and subunit composition of ionotropic glutamate receptors on synaptic function: modeling and simulation studies. IEEE/ACM Trans Comput Biol Bioinform 2017; 14:892-904. [PMID: 27164603 DOI: 10.1109/tcbb.2016.2561932] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ionotropic NMDA and AMPA glutamate receptors (iGluRs) play important roles in synaptic function under physiological and pathological conditions. iGluRs sub-synaptic localization and subunit composition are dynamically regulated by activity-dependent insertion and internalization. However, understanding the impact on synaptic transmission of changes in composition and localization of iGluRs is difficult to address experimentally. To address this question, we developed a detailed computational model of glutamatergic synapses, including spine and dendritic compartments, elementary models of subtypes of NMDA and AMPA receptors, glial glutamate transporters, intracellular calcium and a calcium-dependent signaling cascade underlying the development of long-term potentiation (LTP). These synapses were distributed on a neuron model and numerical simulations were performed to assess the impact of changes in composition and localization (synaptic vs extrasynaptic) of iGluRs on synaptic transmission and plasticity following various patterns of presynaptic stimulation. In addition, the effects of various pharmacological compounds targeting NMDARs or AMPARs were determined. Our results showed that changes in NMDAR localization have a greater impact on synaptic plasticity than changes in AMPARs. Moreover, the results suggest that modulators of AMPA and NMDA receptors have differential effects on restoring synaptic plasticity under different experimental situations mimicking various human diseases.
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28
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Zhu G, Briz V, Seinfeld J, Liu Y, Bi X, Baudry M. Calpain-1 deletion impairs mGluR-dependent LTD and fear memory extinction. Sci Rep 2017; 7:42788. [PMID: 28202907 PMCID: PMC5311935 DOI: 10.1038/srep42788] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 01/17/2017] [Indexed: 01/02/2023] Open
Abstract
Recent studies indicate that calpain-1 is required for the induction of long-term potentiation (LTP) elicited by theta-burst stimulation in field CA1 of hippocampus. Here we determined the contribution of calpain-1 in another type of synaptic plasticity, the long-term depression (LTD) elicited by activation of type-I metabotropic glutamate receptors (mGluR-LTD). mGluR-LTD was associated with calpain-1 activation following T-type calcium channel opening, and resulted in the truncation of a regulatory subunit of PP2A, B56α. This signaling pathway was required for both the early and late phase of Arc translation during mGluR-LTD, through a mechanism involving mTOR and ribosomal protein S6 activation. In contrast, in hippocampal slices from calpain-1 knock-out (KO) mice, application of the mGluR agonist, DHPG, did not result in B56α truncation, increased Arc synthesis and reduced levels of membrane GluA1-containing AMPA receptors. Consistently, mGluR-LTD was impaired in calpain-1 KO mice, and the impairment could be rescued by phosphatase inhibitors, which also restored Arc translation in response to DHPG. Furthermore, calpain-1 KO mice exhibited impairment in fear memory extinction to tone presentation. These results indicate that calpain-1 plays a critical role in mGluR-LTD and is involved in many forms of synaptic plasticity and learning and memory.
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Affiliation(s)
- Guoqi Zhu
- Graduate College of Biomedical Sciences, Pomona, CA 91766, USA
- Key Laboratory of Xin’an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei 230038, China
| | - Victor Briz
- Graduate College of Biomedical Sciences, Pomona, CA 91766, USA
- VIB Center for the Biology of Disease, KU Leuven, 3000 Leuven, Belgium
| | - Jeff Seinfeld
- Graduate College of Biomedical Sciences, Pomona, CA 91766, USA
| | - Yan Liu
- Graduate College of Biomedical Sciences, Pomona, CA 91766, USA
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona, CA 91766, CA 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific Western University of Health Sciences Pomona, CA 91766, CA 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Pomona, CA 91766, USA
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Liu Y, Sun J, Wang Y, Lopez D, Tran J, Bi X, Baudry M. Deleting both PHLPP1 and CANP1 rescues impairments in long-term potentiation and learning in both single knockout mice. ACTA ACUST UNITED AC 2016; 23:399-404. [PMID: 27421891 PMCID: PMC4947237 DOI: 10.1101/lm.042721.116] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 05/18/2016] [Indexed: 11/25/2022]
Abstract
Calpain-1 (CANP1) has been shown to play a critical role in synaptic plasticity and learning and memory, as its deletion in mice results in impairment in theta-burst stimulation- (TBS) induced LTP and various forms of learning and memory. Likewise, PHLPP1 (aka SCOP) has also been found to participate in learning and memory, as PHLPP1 overexpression impairs hippocampus-dependent learning. We previously showed that TBS-induced LTP was associated with calpain-1 mediated truncation of PHLPP1.To better understand the roles of these 2 genes in synaptic plasticity and learning and memory, we generated a double knockout (DKO) mouse by crossing the parent strains. Surprisingly, DKO mice exhibit normal TBS-induced LTP, and the learning impairments in fear conditioning and novel object or novel location recognition were absent in the DKO mice. Moreover, TBS-induced ERK activation in field CA1 of hippocampal slices, which is impaired in both single deletion mice, was restored in the DKO mice. These results further strengthen the roles of both CANP1 and PHLPP1 in synaptic plasticity and learning and memory, and illustrate the complexities of the interactions between multiple pathways participating in synaptic plasticity.
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Affiliation(s)
- Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California 91766, USA
| | - Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California 91766, USA
| | - Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California 91766, USA
| | - Dulce Lopez
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California 91766, USA
| | - Jennifer Tran
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California 91766, USA College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, California 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, California 91766, USA
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Wang Y, Hersheson J, Lopez D, Hammer M, Liu Y, Lee KH, Pinto V, Seinfeld J, Wiethoff S, Sun J, Amouri R, Hentati F, Baudry N, Tran J, Singleton AB, Coutelier M, Brice A, Stevanin G, Durr A, Bi X, Houlden H, Baudry M. Defects in the CAPN1 Gene Result in Alterations in Cerebellar Development and Cerebellar Ataxia in Mice and Humans. Cell Rep 2016; 16:79-91. [PMID: 27320912 DOI: 10.1016/j.celrep.2016.05.044] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 04/14/2016] [Accepted: 05/10/2016] [Indexed: 11/16/2022] Open
Abstract
A CAPN1 missense mutation in Parson Russell Terrier dogs is associated with spinocerebellar ataxia. We now report that homozygous or heterozygous CAPN1-null mutations in humans result in cerebellar ataxia and limb spasticity in four independent pedigrees. Calpain-1 knockout (KO) mice also exhibit a mild form of ataxia due to abnormal cerebellar development, including enhanced neuronal apoptosis, decreased number of cerebellar granule cells, and altered synaptic transmission. Enhanced apoptosis is due to absence of calpain-1-mediated cleavage of PH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1), which results in inhibition of the Akt pro-survival pathway in developing granule cells. Injection of neonatal mice with the indirect Akt activator, bisperoxovanadium, or crossing calpain-1 KO mice with PHLPP1 KO mice prevented increased postnatal cerebellar granule cell apoptosis and restored granule cell density and motor coordination in adult mice. Thus, mutations in CAPN1 are an additional cause of ataxia in mammals, including humans.
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Affiliation(s)
- Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Joshua Hersheson
- The National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Dulce Lopez
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Monia Hammer
- Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis 1007, Tunisia; Laboratory of Neurogenetics, National Institutes of Health, Bethesda 20892, MD, USA
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Ka-Hung Lee
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Vanessa Pinto
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Jeff Seinfeld
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Sarah Wiethoff
- The National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK; Center for Neurology and Hertie Institute for Clinical Brain Research, Eberhard-Karls-University, 72076 Tübingen, Germany
| | - Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Rim Amouri
- Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis 1007, Tunisia
| | - Faycal Hentati
- Department of Molecular Neurobiology and Neuropathology, National Institute of Neurology, La Rabta, Tunis 1007, Tunisia
| | - Neema Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Jennifer Tran
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Andrew B Singleton
- Laboratory of Neurogenetics, National Institutes of Health, Bethesda 20892, MD, USA
| | - Marie Coutelier
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, Université Pierre et Marie Curie Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, 75013 Paris, France; Laboratory of Human Molecular Genetics, de Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium; Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres (PSL) Research University, 75013 Paris, France
| | - Alexis Brice
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, Université Pierre et Marie Curie Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, 75013 Paris, France; Centre de Référence de Neurogénétique, Hôpital de la Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Giovanni Stevanin
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, Université Pierre et Marie Curie Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, 75013 Paris, France; Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres (PSL) Research University, 75013 Paris, France; Centre de Référence de Neurogénétique, Hôpital de la Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Alexandra Durr
- INSERM U 1127, CNRS UMR 7225, Sorbonne Universités, Université Pierre et Marie Curie Paris 06 UMRS 1127, Institut du Cerveau et de la Moelle épinière, 75013 Paris, France; Centre de Référence de Neurogénétique, Hôpital de la Pitié-Salpêtrière, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Henry Houlden
- The National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA.
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Abstract
Although calpain was proposed to participate in synaptic plasticity and learning and memory more than 30 years ago, the mechanisms underlying its activation and the roles of different substrates have remained elusive. Recent findings have provided evidence that the two major calpain isoforms in the brain, calpain-1 and calpain-2, play opposite functions in synaptic plasticity. In particular, while calpain-1 activation is the initial trigger for certain forms of synaptic plasticity, that is, long-term potentiation, calpain-2 activation restricts the extent of plasticity. Moreover, while calpain-1 rapidly cleaves regulatory and cytoskeletal proteins, calpain-2-mediated stimulation of local protein synthesis reestablishes protein homeostasis. These findings have important implications for our understanding of learning and memory and disorders associated with impairment in these processes.
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Affiliation(s)
- Victor Briz
- 1 KU Leuven, Center for Human Genetics and Leuven Institute for Neuroscience and Disease, Leuven, Belgium
- 2 VIB Center for the Biology of Disease, Leuven, Belgium
| | - Michel Baudry
- 3 Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
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Sun J, Liu Y, Tran J, O'Neal P, Baudry M, Bi X. mTORC1-S6K1 inhibition or mTORC2 activation improves hippocampal synaptic plasticity and learning in Angelman syndrome mice. Cell Mol Life Sci 2016; 73:4303-4314. [PMID: 27173058 DOI: 10.1007/s00018-016-2269-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 04/27/2016] [Accepted: 05/06/2016] [Indexed: 02/07/2023]
Abstract
Emerging evidence is implicating abnormal activation of the mechanistic target of rapamycin (mTOR) pathway in several monogenetic neuropsychiatric disorders, including Angelman syndrome (AS), which is caused by deficiency in maternally inherited UBE3A. Using an AS mouse model, we show that semi-chronic rapamycin treatment improves long-term potentiation (LTP) and actin polymerization in hippocampal slices, spine morphology, and fear-conditioning learning. Activity of mTORC1 and of its downstream substrate, S6K1, was increased in hippocampus of AS mice. However, mTORC2 activity, as reflected by PKCα levels, was decreased. Both increased mTORC1 and decreased mTORC2 activities were reversed by semi-chronic rapamycin treatment. Acute treatment of hippocampal slices from AS mice with rapamycin or an S6K1 inhibitor, PF4708671, improved LTP, restored actin polymerization, and normalized mTORC1 and mTORC2 activity. These treatments also reduced Arc levels in AS mice. Treatment with Torin 1, an inhibitor of both mTORC1 and mTORC2, partially rescued LTP and actin polymerization in hippocampal slices from AS mice, while partially impairing them in wild-type (WT) mice. Torin 1 decreased mTORC1 and increased mTORC2 activity in slices from AS mice but inhibited both mTORC1 and mTORC2 in WT mice. Finally, an mTORC2 activator, A-443654, increased hippocampal LTP in AS mice and actin polymerization in both WT and AS mice. Collectively, these results indicate that events set in motion by increased mTORC1 and decreased mTORC2 activities, including increased Arc translation and impaired actin remodeling, are crucial in AS pathogenesis. Therefore, selectively targeting these two master kinase complexes may provide new therapeutic approaches for AS treatment.
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Affiliation(s)
- Jiandong Sun
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766, USA
| | - Jennifer Tran
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA
| | - Patrick O'Neal
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766, USA
| | - Xiaoning Bi
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA, 91766-1854, USA.
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Greget R, Dadak S, Barbier L, Lauga F, Linossier-Pierre S, Pernot F, Legendre A, Ambert N, Bouteiller JM, Dorandeu F, Bischoff S, Baudry M, Fagni L, Moussaoui S. Modeling and simulation of organophosphate-induced neurotoxicity: Prediction and validation by experimental studies. Neurotoxicology 2016; 54:140-152. [PMID: 27108687 DOI: 10.1016/j.neuro.2016.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/07/2016] [Accepted: 04/19/2016] [Indexed: 02/07/2023]
Abstract
Exposure to organophosphorus (OP) compounds, either pesticides or chemical warfare agents, represents a major health problem. As potent irreversible inhibitors of cholinesterase, OP may induce seizures, as in status epilepticus, and occasionally brain lesions. Although these compounds are extremely toxic agents, the search for novel antidotes remains extremely limited. In silico modeling constitutes a useful tool to identify pharmacological targets and to develop efficient therapeutic strategies. In the present work, we developed a new in silico simulator in order to predict the neurotoxicity of irreversible inhibitors of acetyl- and/or butyrylcholinesterase (ChE) as well as the potential neuroprotection provided by antagonists of cholinergic muscarinic and glutamate N-methyl-d-aspartate (NMDA) receptors. The simulator reproduced firing of CA1 hippocampal neurons triggered by exposure to paraoxon (POX), as found in patch-clamp recordings in in vitro mouse hippocampal slices. In the case of POX intoxication, it predicted a preventing action of the muscarinic receptor antagonist atropine sulfate, as well as a synergistic action with the non-competitive NMDA receptor antagonist memantine. These in silico predictions relative to beneficial effects of atropine sulfate combined with memantine were recapitulated experimentally in an in vivo model of POX in adult male Swiss mice using electroencephalic (EEG) recordings. Thus, our simulator is a new powerful tool to identify protective therapeutic strategies against OP central effects, by screening various combinations of muscarinic and NMDA receptor antagonists.
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Affiliation(s)
| | - Selma Dadak
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, INSERM, U1191, Université de Montpellier, Montpellier F-34094, France
| | - Laure Barbier
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | - Fabien Lauga
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | - Sandra Linossier-Pierre
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France
| | | | | | | | | | - Frédéric Dorandeu
- Institut de Recherche Biomédicale des Armées (IRBA), Département de Toxicologie et Risques Chimiques, Brétigny sur Orge, France; Ecole du Val-de-Grâce, Paris, France
| | | | | | - Laurent Fagni
- Institut de Génomique Fonctionnelle, CNRS, UMR-5203, INSERM, U1191, Université de Montpellier, Montpellier F-34094, France
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Liu Y, Wang Y, Zhu G, Sun J, Bi X, Baudry M. A calpain-2 selective inhibitor enhances learning & memory by prolonging ERK activation. Neuropharmacology 2016; 105:471-477. [PMID: 26907807 DOI: 10.1016/j.neuropharm.2016.02.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/18/2016] [Accepted: 02/15/2016] [Indexed: 02/04/2023]
Abstract
While calpain-1 activation is required for LTP induction by theta burst stimulation (TBS), calpain-2 activation limits its magnitude during the consolidation period. A selective calpain-2 inhibitor applied either before or shortly after TBS enhanced the degree of potentiation. In the present study, we tested whether the selective calpain-2 inhibitor, Z-Leu-Abu-CONH-CH2-C6H3 (3, 5-(OMe)2 (C2I), could enhance learning and memory in wild-type (WT) and calpain-1 knock-out (C1KO) mice. We first showed that C2I could reestablish TBS-LTP in hippocampal slices from C1KO mice, and this effect was blocked by PD98059, an inhibitor of ERK. TBS resulted in PTEN degradation in hippocampal slices from both WT and C1KO mice, and C2I treatment blocked this effect in both mouse genotypes. Systemic injection of C2I 30 min before training in the fear-conditioning paradigm resulted in a biphasic dose-response curve, with low doses enhancing and high doses inhibiting freezing behavior. The difference between the doses needed to enhance and inhibit learning matches the difference in concentrations producing inhibition of calpain-2 and calpain-1. A low dose of C2I also restored normal learning in a novel object recognition task in C1KO mice. Levels of SCOP, a ERK phosphatase known to be cleaved by calpain-1, were decreased in dorsal hippocampus early but not late following training in WT mice; C2I treatment did not affect the early decrease in SCOP levels but prevented its recovery at the later time-point and prolonged ERK activation. The results indicate that calpain-2 activation limits the extent of learning, an effect possibly due to temporal limitation of ERK activation, as a result of SCOP synthesis induced by calpain-2-mediated PTEN degradation.
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Affiliation(s)
- Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Yubin Wang
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Guoqi Zhu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Jiandong Sun
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA.
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Abstract
INTRODUCTION Angelman syndrome (AS) is a neurodevelopmental disorder caused by deficiency of maternally inherited UBE3A, an ubiquitin E3 ligase. Despite recent progress in understanding the mechanism underlying UBE3A imprinting, there is no effective treatment. Further investigation of the roles played by UBE3A in the central nervous system (CNS) is needed for developing effective therapies. AREA COVERED This review covers the literature related to genetic classifications of AS, recent discoveries regarding the regulation of UBE3A imprinting, alterations in cell signaling in various brain regions and potential therapeutic approaches. Since a large proportion of AS patients exhibit comorbid autism spectrum disorder (ASD), potential common molecular bases are discussed. EXPERT OPINION Advances in understanding UBE3A imprinting provide a unique opportunity to induce paternal UBE3A expression, thus targeting the syndrome at its 'root.' However, such efforts have yielded less-than-expected rescue effects in AS mouse models, raising the concern that activation of paternal UBE3A after a critical period cannot correct all the CNS defects that developed in a UBE3A-deficient environment. On the other hand, targeting abnormal downstream cell signaling pathways has provided promising rescue effects in preclinical research. Thus, combined reinstatement of paternal UBE3A expression with targeting abnormal signaling pathways should provide better therapeutic effects.
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Affiliation(s)
- Xiaoning Bi
- a Department of Basic Medical Sciences, COMP , Western University of Health Sciences , Pomona , CA , USA
| | - Jiandong Sun
- a Department of Basic Medical Sciences, COMP , Western University of Health Sciences , Pomona , CA , USA
| | - Angela X Ji
- a Department of Basic Medical Sciences, COMP , Western University of Health Sciences , Pomona , CA , USA
| | - Michel Baudry
- b Graduate College of Biomedical Sciences , Western University of Health Sciences , Pomona , CA , USA
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Allam SL, Bouteiller JMC, Hu EY, Ambert N, Greget R, Bischoff S, Baudry M, Berger TW. Synaptic Efficacy as a Function of Ionotropic Receptor Distribution: A Computational Study. PLoS One 2015; 10:e0140333. [PMID: 26480028 PMCID: PMC4610697 DOI: 10.1371/journal.pone.0140333] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 09/24/2015] [Indexed: 11/22/2022] Open
Abstract
Glutamatergic synapses are the most prevalent functional elements of information processing in the brain. Changes in pre-synaptic activity and in the function of various post-synaptic elements contribute to generate a large variety of synaptic responses. Previous studies have explored postsynaptic factors responsible for regulating synaptic strength variations, but have given far less importance to synaptic geometry, and more specifically to the subcellular distribution of ionotropic receptors. We analyzed the functional effects resulting from changing the subsynaptic localization of ionotropic receptors by using a hippocampal synaptic computational framework. The present study was performed using the EONS (Elementary Objects of the Nervous System) synaptic modeling platform, which was specifically developed to explore the roles of subsynaptic elements as well as their interactions, and that of synaptic geometry. More specifically, we determined the effects of changing the localization of ionotropic receptors relative to the presynaptic glutamate release site, on synaptic efficacy and its variations following single pulse and paired-pulse stimulation protocols. The results indicate that changes in synaptic geometry do have consequences on synaptic efficacy and its dynamics.
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Affiliation(s)
- Sushmita L. Allam
- Center for Neural Engineering, Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
| | - Jean-Marie C. Bouteiller
- Center for Neural Engineering, Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
- Rhenovia Pharma, Mulhouse, France
- * E-mail:
| | - Eric Y. Hu
- Center for Neural Engineering, Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
| | | | | | | | - Michel Baudry
- Rhenovia Pharma, Mulhouse, France
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, United States of America
| | - Theodore W. Berger
- Center for Neural Engineering, Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States of America
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Briz V, Liu Y, Zhu G, Bi X, Baudry M. A novel form of synaptic plasticity in field CA3 of hippocampus requires GPER1 activation and BDNF release. J Exp Med 2015. [DOI: 10.1084/jem.21211oia92] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Baudry M. Meet Our Editorial Board Member:. Curr Neuropharmacol 2015. [DOI: 10.2174/1570159x1305151013194644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Briz V, Liu Y, Zhu G, Bi X, Baudry M. A novel form of synaptic plasticity in field CA3 of hippocampus requires GPER1 activation and BDNF release. J Cell Biol 2015; 210:1225-37. [PMID: 26391661 PMCID: PMC4586750 DOI: 10.1083/jcb.201504092] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/19/2015] [Indexed: 01/11/2023] Open
Abstract
Estrogen gates metabotropic glutamate receptor–dependent long-term depression at mossy fiber–CA3 synapses through a mechanism involving GPER1-mediated BDNF release, mTOR-dependent protein synthesis, and proteasome activity. Estrogen is an important modulator of hippocampal synaptic plasticity and memory consolidation through its rapid action on membrane-associated receptors. Here, we found that both estradiol and the G-protein–coupled estrogen receptor 1 (GPER1) specific agonist G1 rapidly induce brain-derived neurotrophic factor (BDNF) release, leading to transient stimulation of activity-regulated cytoskeleton-associated (Arc) protein translation and GluA1-containing AMPA receptor internalization in field CA3 of hippocampus. We also show that type-I metabotropic glutamate receptor (mGluR) activation does not induce Arc translation nor long-term depression (LTD) at the mossy fiber pathway, as opposed to its effects in CA1, and it only triggers LTD after GPER1 stimulation. Furthermore, this form of mGluR-dependent LTD is associated with ubiquitination and proteasome-mediated degradation of GluA1, and is prevented by proteasome inhibition. Overall, our study identifies a novel mechanism by which estrogen and BDNF regulate hippocampal synaptic plasticity in the adult brain.
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Affiliation(s)
- Victor Briz
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766 VIB Center for the Biology of Disease, Katholieke Universiteit Leuven, 3000 Leuven, Belgium
| | - Yan Liu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766 College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766
| | - Guoqi Zhu
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766 Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Traditional Chinese Medicine, Hefei 230038, China
| | - Xiaoning Bi
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766
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Hu EY, Bouteiller JMC, Song D, Baudry M, Berger TW. Volterra representation enables modeling of complex synaptic nonlinear dynamics in large-scale simulations. Front Comput Neurosci 2015; 9:112. [PMID: 26441622 PMCID: PMC4585022 DOI: 10.3389/fncom.2015.00112] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/25/2015] [Indexed: 12/01/2022] Open
Abstract
Chemical synapses are comprised of a wide collection of intricate signaling pathways involving complex dynamics. These mechanisms are often reduced to simple spikes or exponential representations in order to enable computer simulations at higher spatial levels of complexity. However, these representations cannot capture important nonlinear dynamics found in synaptic transmission. Here, we propose an input-output (IO) synapse model capable of generating complex nonlinear dynamics while maintaining low computational complexity. This IO synapse model is an extension of a detailed mechanistic glutamatergic synapse model capable of capturing the input-output relationships of the mechanistic model using the Volterra functional power series. We demonstrate that the IO synapse model is able to successfully track the nonlinear dynamics of the synapse up to the third order with high accuracy. We also evaluate the accuracy of the IO synapse model at different input frequencies and compared its performance with that of kinetic models in compartmental neuron models. Our results demonstrate that the IO synapse model is capable of efficiently replicating complex nonlinear dynamics that were represented in the original mechanistic model and provide a method to replicate complex and diverse synaptic transmission within neuron network simulations.
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Affiliation(s)
- Eric Y Hu
- Department of Biomedical Engineering, University of Southern California Los Angeles, CA, USA
| | - Jean-Marie C Bouteiller
- Department of Biomedical Engineering, University of Southern California Los Angeles, CA, USA
| | - Dong Song
- Department of Biomedical Engineering, University of Southern California Los Angeles, CA, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences Pomona, CA, USA
| | - Theodore W Berger
- Department of Biomedical Engineering, University of Southern California Los Angeles, CA, USA
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Sun J, Zhu G, Liu Y, Standley S, Ji A, Tunuguntla R, Wang Y, Claus C, Luo Y, Baudry M, Bi X. UBE3A Regulates Synaptic Plasticity and Learning and Memory by Controlling SK2 Channel Endocytosis. Cell Rep 2015; 12:449-61. [PMID: 26166566 DOI: 10.1016/j.celrep.2015.06.023] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 04/30/2015] [Accepted: 06/07/2015] [Indexed: 11/17/2022] Open
Abstract
Gated solely by activity-induced changes in intracellular calcium, small-conductance potassium channels (SKs) are critical for a variety of functions in the CNS, from learning and memory to rhythmic activity and sleep. While there is a wealth of information on SK2 gating, kinetics, and Ca(2+) sensitivity, little is known regarding the regulation of SK2 subcellular localization. We report here that synaptic SK2 levels are regulated by the E3 ubiquitin ligase UBE3A, whose deficiency results in Angelman syndrome and overexpression in increased risk of autistic spectrum disorder. UBE3A directly ubiquitinates SK2 in the C-terminal domain, which facilitates endocytosis. In UBE3A-deficient mice, increased postsynaptic SK2 levels result in decreased NMDA receptor activation, thereby impairing hippocampal long-term synaptic plasticity. Impairments in both synaptic plasticity and fear conditioning memory in UBE3A-deficient mice are significantly ameliorated by blocking SK2. These results elucidate a mechanism by which UBE3A directly influences cognitive function.
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Affiliation(s)
- Jiandong Sun
- Western University of Health Sciences, Pomona, CA 91766, USA
| | - Guoqi Zhu
- Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Traditional Chinese Medicine, Hefei 230038, China
| | - Yan Liu
- Western University of Health Sciences, Pomona, CA 91766, USA
| | - Steve Standley
- Western University of Health Sciences, Pomona, CA 91766, USA
| | - Angela Ji
- Western University of Health Sciences, Pomona, CA 91766, USA
| | | | - Yubin Wang
- Western University of Health Sciences, Pomona, CA 91766, USA
| | - Chad Claus
- Western University of Health Sciences, Pomona, CA 91766, USA
| | - Yun Luo
- Western University of Health Sciences, Pomona, CA 91766, USA
| | - Michel Baudry
- Western University of Health Sciences, Pomona, CA 91766, USA
| | - Xiaoning Bi
- Western University of Health Sciences, Pomona, CA 91766, USA.
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Liao G, Wang Z, Lee E, Moreno S, Abuelnasr O, Baudry M, Bi X. Enhanced expression of matrix metalloproteinase-12 contributes to Npc1 deficiency-induced axonal degeneration. Exp Neurol 2015; 269:67-74. [PMID: 25864931 DOI: 10.1016/j.expneurol.2015.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 01/08/2015] [Accepted: 04/02/2015] [Indexed: 11/28/2022]
Abstract
Niemann-Pick type C (NPC) disease is a genetic disorder associated with intracellular cholesterol accumulation in the brain and other organs, and neurodegeneration is generally believed to be the fatal cause of the disease. In view of the emerging role of matrix metalloproteinase-12 (MMP-12) in neuronal injury, we investigated its expression and potential roles in axonal degeneration in Npc1-/- mouse brain. Microarray and quantitative real-time reversed transcription PCR analysis indicated a marked increase in MMP-12 mRNA levels in cerebellum of 3 week-old Npc1-/- mice, as compared to wild-type littermates. Western blots showed that the ratio of mature MMP-12 over pro-MMP-12 was significantly increased in cerebellum of Npc1-/-, as compared to wild-type mice. Immunohistochemical studies confirmed that MMP-12 expression was increased, especially in the cell bodies of Purkinje neurons in Npc1-/- mice. Neuritic growth was significantly reduced by Npc1 siRNA knockdown in nerve growth factor-differentiated PC-12 cells, and this effect was completely reversed by treatment with an MMP-12 specific inhibitor. Furthermore, in vivo experiments showed that chronic treatment with the MMP-12 inhibitor ameliorated Npc1 deficiency-induced axonal pathology in the striatum. Our results indicate that abnormal neuronal expression of MMP-12 may contribute to axonal degeneration in NPC disease, thus providing a potential novel target for treatment.
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Affiliation(s)
- Guanghong Liao
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA 91766, USA
| | - Zhuangjun Wang
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA 91766, USA
| | - Erik Lee
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA 91766, USA
| | - Stephanie Moreno
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA 91766, USA
| | - Omar Abuelnasr
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA 91766, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, 701 E. Second Street, Pomona, CA 91766, USA
| | - Xiaoning Bi
- Department of Basic Medical Sciences, COMP, Western University of Health Sciences, 701 E. Second Street, Pomona, CA 91766, USA.
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Lopez D, Pinto V, Wang Y, Liu Y, Seinfeld J, Bi X, Baudry M. Calpain‐1 Knockout in Mice Causes Degeneration of Cerebellar Granule Cells and Ataxia. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.727.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Dulce Lopez
- Graduate College of Biomedical Sciences Western University of Health SciencesPomonaCAUnited States
| | - Vanessa Pinto
- Graduate College of Biomedical Sciences Western University of Health SciencesPomonaCAUnited States
| | - Yubin Wang
- Graduate College of Biomedical Sciences Western University of Health SciencesPomonaCAUnited States
| | - Yan Liu
- Graduate College of Biomedical Sciences Western University of Health SciencesPomonaCAUnited States
| | - Jeffrey Seinfeld
- Graduate College of Biomedical Sciences Western University of Health SciencesPomonaCAUnited States
| | - Xiaoning Bi
- Graduate College of Biomedical Sciences Western University of Health SciencesPomonaCAUnited States
| | - Michel Baudry
- Graduate College of Biomedical Sciences Western University of Health SciencesPomonaCAUnited States
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Briz V, Baudry M. Estrogen Regulates Protein Synthesis and Actin Polymerization in Hippocampal Neurons through Different Molecular Mechanisms. Front Endocrinol (Lausanne) 2014; 5:22. [PMID: 24611062 PMCID: PMC3933789 DOI: 10.3389/fendo.2014.00022] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 02/13/2014] [Indexed: 12/21/2022] Open
Abstract
Estrogen rapidly modulates hippocampal synaptic plasticity by activating selective membrane-associated receptors. Reorganization of the actin cytoskeleton and stimulation of mammalian target of rapamycin (mTOR)-mediated protein synthesis are two major events required for the consolidation of hippocampal long-term potentiation and memory. Estradiol regulates synaptic plasticity by interacting with both processes, but the underlying molecular mechanisms are not yet fully understood. Here, we used acute rat hippocampal slices to analyze the mechanisms underlying rapid changes in mTOR activity and actin polymerization elicited by estradiol. Estradiol-induced mTOR phosphorylation was preceded by rapid and transient activation of both extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) and by phosphatase and tensin homolog (PTEN) degradation. These effects were prevented by calpain and ERK inhibitors. Estradiol-induced mTOR stimulation did not require activation of classical estrogen receptors (ER), as specific ERα and ERβ agonists (PPT and DPN, respectively) failed to mimic this effect, and ER antagonists could not block it. Estradiol rapidly activated both RhoA and p21-activated kinase (PAK). Furthermore, a specific inhibitor of RhoA kinase (ROCK), H1152, and a potent and specific PAK inhibitor, PF-3758309, blocked estradiol-induced cofilin phosphorylation and actin polymerization. ER antagonists also blocked these effects of estrogen. Consistently, both PPT and DPN stimulated PAK and cofilin phosphorylation as well as actin polymerization. Finally, the effects of estradiol on actin polymerization were insensitive to protein synthesis inhibitors, but its stimulation of mTOR activity was impaired by latrunculin A, a drug that disrupts actin filaments. Taken together, our results indicate that estradiol regulates local protein synthesis and cytoskeletal reorganization via different molecular mechanisms and signaling pathways.
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Affiliation(s)
- Victor Briz
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
| | - Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA, USA
- *Correspondence: Michel Baudry, Graduate College of Biomedical Sciences, Western University of Health Sciences, NSC, Room 102C, 309 E. 2nd Street, Pomona, CA 91766-1854, USA e-mail:
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Bouteiller JMC, Allam SL, Ambert N, Greget R, Hu E, Bischoff S, Baudry M, Berger TW. Influence of ionotropic receptors localization on glutamatergic synaptic response to paired-pulse stimulation protocol. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2013:1037-40. [PMID: 24109868 DOI: 10.1109/embc.2013.6609681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Paired-pulse protocol is a stimulation pattern that is often used to characterize short-term changes in synaptic potency. Responses to such protocol often yield varying results, going from a depressing response to a facilitated one following the second pulse. Similarly, experimental results have shown that synaptic structures are dynamic and receptors move along the postsynaptic membrane. The present study provides insights on the impact of glutamatergic receptors localization with respect to the neurotransmitters release site on the postsynaptic currents measured; it also proposes an explanation on the diversity of responses observed experimentally. The platform we used is the EONS/RHENOMS modeling platform widely described in the literature, which encompasses a multitude of highly detailed subsynaptic elements to most faithfully replicate synaptic function.
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Allam SL, Bouteiller JMC, Hu E, Greget R, Ambert N, Bischoff S, Baudry M, Berger TW. Influence of ionotropic receptor location on their dynamics at glutamatergic synapses. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2012:1374-7. [PMID: 23366155 DOI: 10.1109/embc.2012.6346194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In this paper we study the effects of the location of ionotropic receptors, especially AMPA and NMDA receptors, on their function at excitatory glutamatergic synapses. As few computational models only allow to evaluate the influence of receptor location on state transition and receptor dynamics, we present an elaborate computational model of a glutamatergic synapse that takes into account detailed parametric models of ionotropic receptors along with glutamate diffusion within the synaptic cleft. Our simulation results underscore the importance of the wide spread distribution of AMPA receptors which is required to avoid massive desensitization of these receptors following a single glutamate release event while NMDA receptor location is potentially optimal relative to the glutamate release site thus, emphasizing the contribution of location dependent effects of the two major ionotropic receptors to synaptic efficacy.
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Affiliation(s)
- Sushmita L Allam
- Department of Biomedical Engineering, University of Southern California, 1042 Downey Way, DRB Building, Los Angeles, CA 90089-111, USA.
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Baudry M, Bi X, Aguirre C. Progesterone-estrogen interactions in synaptic plasticity and neuroprotection. Neuroscience 2013; 239:280-94. [PMID: 23142339 PMCID: PMC3628409 DOI: 10.1016/j.neuroscience.2012.10.051] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 10/23/2012] [Accepted: 10/26/2012] [Indexed: 01/01/2023]
Abstract
17ß-Estradiol and progesterone exert a number of physiological effects throughout the brain due to interactions with several types of receptors belonging to the traditional family of intracellular hormonal receptors as well as to membrane-bound receptors. In particular, both hormones elicit rapid modifications of neuronal excitability that have been postulated to underlie their effects on synaptic plasticity and learning and memory. Likewise, both hormones have been shown to be neuroprotective under certain conditions, possibly due to the activation of pro-survival pathways and the inhibition of pro-apoptotic cascades. Because of the similarities in their cellular effects, there have been a number of questions raised by numerous observations that progesterone inhibits the effects of estrogen. In this manuscript, we first review the interactions between 17ß-estradiol (E2) and progesterone (P4) in synaptic plasticity, and conclude that, while E2 exerts a clear and important role in long-term potentiation of synaptic transmission in hippocampal neurons, the role of P4 is much less clear, and could be accounted by the direct or indirect regulation of GABAA receptors. We then discuss the neuroprotective roles of both hormones, in particular against excitotoxicity. In this case, the neuroprotective effects of these hormones are very similar to those of the neurotrophic factor BDNF. Interestingly, P4 antagonizes the effects of E2, possibly through the regulation of estrogen receptors or of proteins associated with the receptors or interactions with signaling pathways activated by E2. Overall, this review emphasizes the existence of common molecules and pathways that participate in the regulation of both synaptic plasticity and neurodegeneration.
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Affiliation(s)
- M Baudry
- GCBS and COMP, Western University of Health Sciences, Pomona, CA, USA.
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Baudry M, Bi X. Learning and memory: an emergent property of cell motility. Neurobiol Learn Mem 2013; 104:64-72. [PMID: 23707799 DOI: 10.1016/j.nlm.2013.04.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 04/29/2013] [Accepted: 04/30/2013] [Indexed: 01/24/2023]
Abstract
In this review, we develop the argument that the molecular/cellular mechanisms underlying learning and memory are an adaptation of the mechanisms used by all cells to regulate cell motility. Neuronal plasticity and more specifically synaptic plasticity are widely recognized as the processes by which information is stored in neuronal networks engaged during the acquisition of information. Evidence accumulated over the last 25 years regarding the molecular events underlying synaptic plasticity at excitatory synapses has shown the remarkable convergence between those events and those taking place in cells undergoing migration in response to extracellular signals. We further develop the thesis that the calcium-dependent protease, calpain, which we postulated over 25 years ago to play a critical role in learning and memory, plays a central role in the regulation of both cell motility and synaptic plasticity. The findings discussed in this review illustrate the general principle that fundamental cell biological processes are used for a wide range of functions at the level of organisms.
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Affiliation(s)
- Michel Baudry
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA.
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Abstract
INTRODUCTION Calpains represent a family of neutral, calcium-dependent proteases, which modify the function of their target proteins by partial truncation. These proteases have been implicated in numerous cell functions, including cell division, proliferation, migration, and death. In the CNS, where µ-calpain and m-calpain are the main calpain isoforms, their activation has been linked to synaptic plasticity as well as to neurodegeneration. This review will focus on the role of calpains in synaptic plasticity and discuss the possibility of developing methods to manipulate calpain activity for therapeutic purposes. AREAS COVERED This review covers the literature showing how calpains are implicated in synaptic plasticity and in a number of conditions associated with learning impairment. The possibility of developing new drugs targeting these enzymes for treating these conditions is discussed. EXPERT OPINION As evidence accumulates that calpain activation participates in neurodegeneration and cancer, there is interest in developing therapeutic approaches using direct or indirect calpain inhibition. In particular, a peptide derived from the calpain truncation site of mGluR1α was shown to decrease neurodegeneration following neonatal hypoxia/ischemia. More selective approaches need to be developed to target calpain or some of its substrates for therapeutic indications associated with deregulation of synaptic plasticity.
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Affiliation(s)
- Michel Baudry
- Western University of Health Sciences, Graduate College of Biomedical Sciences, Basic Medical Sciences, COMP , 309 E 2nd St, Pomona, CA 91766, USA.
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