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Zhang S, Yan ML, Yang L, An XB, Zhao HM, Xia SN, Jin Z, Huang SY, Qu Y, Ai J. MicroRNA-153 impairs hippocampal synaptic vesicle trafficking via downregulation of synapsin I in rats following chronic cerebral hypoperfusion. Exp Neurol 2020; 332:113389. [PMID: 32580014 DOI: 10.1016/j.expneurol.2020.113389] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 05/02/2020] [Accepted: 06/18/2020] [Indexed: 02/07/2023]
Abstract
Chronic cerebral hypoperfusion (CCH) promotes the development of Alzheimer's pathology. However, whether and how CCH impairs the synaptic vesicle trafficking is still unclear. In the present study, we found that the hippocampal glutamatergic vesicle trafficking was impaired as indicated by a significant shortened delayed response enhancement (DRE) phase in CA3-CA1 circuit and decreased synapsin I in CCH rats suffering from bilateral common carotid artery occlusion (2VO). Further study showed an upregulated miR-153 in the hippocampus of 2VO rats. In vitro, overexpression of miR-153 downregulated synapsin I by binding the 3'UTRs of SYN1 mRNAs, which was prevented by its antisense AMO-153 and miRNA-masking antisense oligodeoxynucleotides (SYN1-ODN). In vivo, the upregulation of miR-153 elicited similar reduced DRE phase and synapsin I deficiency as CCH. Furthermore, miR-153 knockdown rescued the downregulated synapsin I and shortened DRE phase in 2VO rats. Our results demonstrate that CCH impairs hippocampal glutamatergic vesicle trafficking by upregulating miR-153, which suppresses the expression of synapsin I at the post-transcriptional level. These results will provide important references for drug research and treatment of vascular dementia.
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Affiliation(s)
- Shuai Zhang
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Mei-Ling Yan
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Lin Yang
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Xiao-Bin An
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Hong-Mei Zhao
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Sheng-Nan Xia
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Zhuo Jin
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Si-Yu Huang
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Yang Qu
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China
| | - Jing Ai
- Department of Pharmacology (The State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), College of Pharmacy of Harbin Medical University, Harbin, Heilongjiang Province 150086, China.
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Synapsin II and Rab3a cooperate in the regulation of epileptic and synaptic activity in the CA1 region of the hippocampus. J Neurosci 2014; 33:18319-30. [PMID: 24227741 DOI: 10.1523/jneurosci.5293-12.2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Some forms of idiopathic epilepsy in animals and humans are associated with deficiency of synapsin, a phosphoprotein that reversibly associates with synaptic vesicles. We have previously shown that the epileptic phenotype seen in synapsin II knock-out mice (SynII(-)) can be rescued by the genetic deletion of the Rab3a protein. Here we have examined the cellular basis for this rescue using whole-cell recordings from CA1 hippocampal pyramidal cells in brain slices. We find that SynII(-) neurons have increased spontaneous activity and a reduced threshold for the induction of epileptiform activity by 4-aminopyridine (4-AP). Using selective recordings of glutamatergic and GABAergic activity we show that in wild-type neurons low concentrations of 4-AP facilitate glutamatergic and GABAergic transmission in a balanced way, whereas in SynII(-) neurons this balance is shifted toward excitation. This imbalance reflects a deficit in inhibitory synaptic transmission that appears to be secondary to reduced Ca(2+) sensitivity in SynII(-) neurons. This suggestion is supported by our finding that synaptic and epileptiform activity at SynII(-) and wild-type synapses is similar when GABAergic transmission is blocked. Deletion of Rab3a results in glutamatergic synapses that have a compromised responsiveness to either low 4-AP concentrations or elevated extracellular Ca(2+). These changes mitigate the overexcitable phenotype observed in SynII(-) neurons. Thus, Rab3a deletion appears to restore the excitatory/inhibitory imbalance observed in SynII(-) hippocampal slices indirectly, not by correcting the deficit in GABAergic synaptic transmission but rather by impairing excitatory glutamatergic synaptic transmission.
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Ruggiero A, Wright J, Ferguson SM, Lewis M, Emerson K, Iwamoto H, Ivy MT, Holmstrand EC, Ennis EA, Weaver CD, Blakely RD. Nonoisotopic assay for the presynaptic choline transporter reveals capacity for allosteric modulation of choline uptake. ACS Chem Neurosci 2012; 3:767-81. [PMID: 23077721 PMCID: PMC3474274 DOI: 10.1021/cn3000718] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Accepted: 07/09/2012] [Indexed: 11/29/2022] Open
Abstract
Current therapies to enhance CNS cholinergic function rely primarily on extracellular acetylcholinesterase (AChE) inhibition, a pharmacotherapeutic strategy that produces dose-limiting side effects. The Na(+)-dependent, high-affinity choline transporter (CHT) is an unexplored target for cholinergic medication development. Although functional at the plasma membrane, CHT at steady-state is localized to synaptic vesicles such that vesicular fusion can support a biosynthetic response to neuronal excitation. To identify allosteric potentiators of CHT activity, we mapped endocytic sequences in the C-terminus of human CHT, identifying transporter mutants that exhibit significantly increased transport function. A stable HEK-293 cell line was generated from one of these mutants (CHT LV-AA) and used to establish a high-throughput screen (HTS) compatible assay based on the electrogenic nature of the transporter. We established that the addition of choline to these cells, at concentrations appropriate for high-affinity choline transport at presynaptic terminals, generates a hemicholinium-3 (HC-3)-sensitive, membrane depolarization that can be used for the screening of CHT inhibitors and activators. Using this assay, we discovered that staurosporine increased CHT LV-AA choline uptake activity, an effect mediated by a decrease in choline K(M) with no change in V(max). As staurosporine did not change surface levels of CHT, nor inhibit HC-3 binding, we propose that its action is directly or indirectly allosteric in nature. Surprisingly, staurosporine reduced choline-induced membrane depolarization, suggesting that increased substrate coupling to ion gradients, arising at the expense of nonstoichiometric ion flow, accompanies a shift of CHT to a higher-affinity state. Our findings provide a new approach for the identification of CHT modulators that is compatible with high-throughput screening approaches and presents a novel model by which small molecules can enhance substrate flux through enhanced gradient coupling.
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Affiliation(s)
- Alicia
M. Ruggiero
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
| | - Jane Wright
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
| | - Shawn M. Ferguson
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
| | - Michelle Lewis
- Vanderbilt Institute
of Chemical
Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6304, United States
| | - Katie
S. Emerson
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
| | - Hideki Iwamoto
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
| | - Michael T. Ivy
- Department of Biological Sciences, Tennessee State University, Nashville, Tennessee 37209-1561,
United States
| | - Ericka C. Holmstrand
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
| | - Elizabeth. A. Ennis
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
| | - C. David Weaver
- Vanderbilt Institute
of Chemical
Biology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-6304, United States
- Department
of Pharmacology, Vanderbilt University School of Medicine, Nashville,
Tennessee 37232-6600, United States
| | - Randy D. Blakely
- Center for Molecular
Neuroscience,
Department of Pharmacology, Vanderbilt University School
of Medicine, Nashville, Tennessee 37232-8548, United
States
- Department of Psychiatry, Vanderbilt
University School of Medicine, Nashville,
Tennessee 37232-8548, United States
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Bogen IL, Jensen V, Hvalby Ø, Walaas SI. Glutamatergic neurotransmission in the synapsin I and II double knock-out mouse. Semin Cell Dev Biol 2011; 22:400-7. [DOI: 10.1016/j.semcdb.2011.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 07/13/2011] [Indexed: 01/19/2023]
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