1
|
Yang T, Xiao T, Sun Q, Wang K. The current agonists and positive allosteric modulators of α7 nAChR for CNS indications in clinical trials. Acta Pharm Sin B 2017; 7:611-22. [PMID: 29159020 DOI: 10.1016/j.apsb.2017.09.001] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 08/02/2017] [Accepted: 08/25/2017] [Indexed: 01/06/2023] Open
Abstract
The alpha-7 nicotinic acetylcholine receptor (α7 nAChR), consisting of homomeric α7 subunits, is a ligand-gated Ca2+-permeable ion channel implicated in cognition and neuropsychiatric disorders. Enhancement of α7 nAChR function is considered to be a potential therapeutic strategy aiming at ameliorating cognitive deficits of neuropsychiatric disorders such as Alzheimer's disease (AD) and schizophrenia. Currently, a number of α7 nAChR modulators have been reported and several of them have advanced into clinical trials. In this brief review, we outline recent progress made in understanding the role of the α7 nAChR in multiple neuropsychiatric disorders and the pharmacological effects of α7 nAChR modulators used in clinical trials.
Collapse
Key Words
- 5-CSRTT, five-choice serial reaction time task
- 5-HT, serotonin
- ACh, acetylcholine
- AD, Alzheimer's disease
- ADHD, attention deficit hyperactivity disorder
- Acetylcholine
- Alpha7
- Alzheimer's disease
- Aβ, amyloid-β peptide
- CNS, central nervous system
- DMTS, delayed matching-to-sample
- ECD, extracellular domain
- GABA, γ-aminobutyric acid
- Ion channel
- MLA, methyllycaconitine
- NOR, novel object recognition
- PAMs, positive allosteric modulators
- PCP, neonatal phencyclidine
- PD, Parkinson's disease
- PPI, prepulse inhibition
- Positive allosteric modulators
- SAR, structure–activity relationship
- Schizophrenia
- TMD, transmembrane domains
- nAChR
- nAChR, nicotinic acetylcholine receptor
- α-Btx, α-bungarotoxin
Collapse
|
2
|
Wanngren J, Lara P, Ojemalm K, Maioli S, Moradi N, Chen L, Tjernberg LO, Lundkvist J, Nilsson I, Karlström H. Changed membrane integration and catalytic site conformation are two mechanisms behind the increased Aβ42/Aβ40 ratio by presenilin 1 familial Alzheimer-linked mutations. FEBS Open Bio 2014; 4:393-406. [PMID: 24918054 PMCID: PMC4050182 DOI: 10.1016/j.fob.2014.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [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: 04/11/2014] [Revised: 04/16/2014] [Accepted: 04/17/2014] [Indexed: 01/11/2023] Open
Abstract
Familial Alzheimer disease (FAD) mutations affect presenilin membrane integration. The transmembrane domains around the catalytic site are vulnerable to changes. All FAD mutations cause changes in the active site of the γ-secretase complex. The FAD mutants lead to a complex processing pattern of the amyloid precursor protein.
The enzyme complex γ-secretase generates amyloid β-peptide (Aβ), a 37–43-residue peptide associated with Alzheimer disease (AD). Mutations in presenilin 1 (PS1), the catalytical subunit of γ-secretase, result in familial AD (FAD). A unifying theme among FAD mutations is an alteration in the ratio Aβ species produced (the Aβ42/Aβ40 ratio), but the molecular mechanisms responsible remain elusive. In this report we have studied the impact of several different PS1 FAD mutations on the integration of selected PS1 transmembrane domains and on PS1 active site conformation, and whether any effects translate to a particular amyloid precursor protein (APP) processing phenotype. Most mutations studied caused an increase in the Aβ42/Aβ40 ratio, but via different mechanisms. The mutations that caused a particular large increase in the Aβ42/Aβ40 ratio did also display an impaired APP intracellular domain (AICD) formation and a lower total Aβ production. Interestingly, seven mutations close to the catalytic site caused a severely impaired integration of proximal transmembrane/hydrophobic sequences into the membrane. This structural defect did not correlate to a particular APP processing phenotype. Six selected FAD mutations, all of which exhibited different APP processing profiles and impact on PS1 transmembrane domain integration, were found to display an altered active site conformation. Combined, our data suggest that FAD mutations affect the PS1 structure and active site differently, resulting in several complex APP processing phenotypes, where the most aggressive mutations in terms of increased Aβ42/Aβ40 ratio are associated with a decrease in total γ-secretase activity.
Collapse
Key Words
- AD, Alzheimer disease
- AICD, amyloid precursor protein intracellular domain
- APP, amyloid precursor protein
- Alzheimer disease
- Amyloid β-peptide
- Aβ, amyloid-β peptide
- BD8, blastocyst-derived embryonic stem cells
- Bis-Tris, 2-(bis(2-hydroxyethyl)amino)-2-(hydroxymethyl)propane-1,3-diol
- CHAPSO, 3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonic acid
- CRM, column-washed dog pancreas rough microsomes
- CTF, C-terminal fragment
- ER, endoplasmic reticulum
- Endo H, endoglycosidase H
- FAD, familial AD
- FLIM/FRET, Fluorescence Lifetime Imaging/ Fluorescence Resonance Energy Transfer
- GCB, γ-secretase inhibitor coupled to biotin
- GVP, Gal4VP16
- Lep, leader peptidase
- MGD, minimal glycosylation distance
- MSD, Meso Scale Discovery
- Membrane integration
- NTF, N-terminal fragment
- PS, presenilin
- Protein structure
- RM, rough microsomes
- TMD, transmembrane domains
- WT, wild type
- γ-Secretase
Collapse
Affiliation(s)
- Johanna Wanngren
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Patricia Lara
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Karin Ojemalm
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Silvia Maioli
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Nasim Moradi
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Lu Chen
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Lars O Tjernberg
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | | | - IngMarie Nilsson
- Department of Biochemistry & Biophysics, Stockholm University, Stockholm, Sweden
| | - Helena Karlström
- Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
3
|
Abe TK, Taniguchi M. Identification of myo-inositol hexakisphosphate (IP6) as a β-secretase 1 (BACE1) inhibitory molecule in rice grain extract and digest. FEBS Open Bio 2014; 4:162-7. [PMID: 24649396 DOI: 10.1016/j.fob.2014.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Revised: 01/24/2014] [Accepted: 01/25/2014] [Indexed: 11/29/2022] Open
Abstract
Rice grain extract and digest inhibited BACE1 activity in vitro. Rice digest inhibited amyloid-β peptide (Aβ) production in cultured neuroblastoma cells. Rice extract and digest contained IP6 and IP4. IP6 but not IP3, IP4 or IP5 inhibited BACE1 activity in vitro. IP6 inhibited production of Aβ and β-CTF in cultured neuroblastoma cells.
Alzheimer’s disease (AD) is widely considered to be caused by amyloid-β peptide (Aβ) accumulation in the brain. Aβ is excised from amyloid-β precursor protein through sequential cleavage by β-secretase 1 (BACE1) and γ-secretase. Thus, BACE1 inhibition could prevent Aβ accumulation. Here, we identified myo-inositol hexakisphosphate (IP6) as a BACE1 inhibitory molecule in rice grain extract and digest. The rice digest and IP6 significantly inhibited Aβ production in neuroblastoma cells without cytotoxicity. These results suggested that rice components, including IP6, may be promising starting materials for the development of potent and safe drugs and/or food to prevent AD.
Collapse
|