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Taylor JL, Martin-Aragon Baudel M, Nieves-Cintron M, Navedo MF. Vascular Function and Ion Channels in Alzheimer's Disease. Microcirculation 2024:e12881. [PMID: 39190776 DOI: 10.1111/micc.12881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024]
Abstract
This review paper explores the critical role of vascular ion channels in the regulation of cerebral artery function and examines the impact of Alzheimer's disease (AD) on these processes. Vascular ion channels are fundamental in controlling vascular tone, blood flow, and endothelial function in cerebral arteries. Dysfunction of these channels can lead to impaired cerebral autoregulation, contributing to cerebrovascular pathologies. AD, characterized by the accumulation of amyloid beta (Aβ) plaques and neurofibrillary tangles, has been increasingly linked to vascular abnormalities, including altered vascular ion channel activity. Here, we briefly review the role of vascular ion channels in cerebral blood flow control and neurovascular coupling. We then examine the vascular defects in AD, the current understanding of how AD pathology affects vascular ion channel function, and how these changes may lead to compromised cerebral blood flow and neurodegenerative processes. Finally, we provide future perspectives and conclusions. Understanding this topic is important as ion channels may be potential therapeutic targets for improving cerebrovascular health and mitigating AD progression.
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Affiliation(s)
- Jade L Taylor
- Department of Pharmacology, University of California Davis, Davis, California, USA
| | | | | | - Manuel F Navedo
- Department of Pharmacology, University of California Davis, Davis, California, USA
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2
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Liu R, Collier JM, Abdul-Rahman NH, Capuk O, Zhang Z, Begum G. Dysregulation of Ion Channels and Transporters and Blood-Brain Barrier Dysfunction in Alzheimer's Disease and Vascular Dementia. Aging Dis 2024; 15:1748-1770. [PMID: 38300642 PMCID: PMC11272208 DOI: 10.14336/ad.2023.1201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/01/2023] [Indexed: 02/02/2024] Open
Abstract
The blood-brain barrier (BBB) plays a critical role in maintaining ion and fluid homeostasis, essential for brain metabolism and neuronal function. Regulation of nutrient, water, and ion transport across the BBB is tightly controlled by specialized ion transporters and channels located within its unique cellular components. These dynamic transport processes not only influence the BBB's structure but also impact vital signaling mechanisms, essential for its optimal function. Disruption in ion, pH, and fluid balance at the BBB is associated with brain pathology and has been implicated in various neurological conditions, including stroke, epilepsy, trauma, and neurodegenerative diseases such as Alzheimer's disease (AD). However, knowledge gaps exist regarding the impact of ion transport dysregulation on BBB function in neurodegenerative dementias. Several factors contribute to this gap: the complex nature of these conditions, historical research focus on neuronal mechanisms and technical challenges in studying the ion transport mechanisms in in vivo models and the lack of efficient in vitro BBB dementia models. This review provides an overview of current research on the roles of ion transporters and channels at the BBB and poses specific research questions: 1) How are the expression and activity of key ion transporters altered in AD and vascular dementia (VaD); 2) Do these changes contribute to BBB dysfunction and disease progression; and 3) Can restoring ion transport function mitigate BBB dysfunction and improve clinical outcomes. Addressing these gaps will provide a greater insight into the vascular pathology of neurodegenerative disorders.
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Affiliation(s)
- Ruijia Liu
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Jenelle M Collier
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
| | | | - Okan Capuk
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Zhongling Zhang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
| | - Gulnaz Begum
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
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Cao Y, Xu W, Liu Q. Alterations of the blood-brain barrier during aging. J Cereb Blood Flow Metab 2024; 44:881-895. [PMID: 38513138 PMCID: PMC11318406 DOI: 10.1177/0271678x241240843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 02/19/2024] [Accepted: 02/28/2024] [Indexed: 03/23/2024]
Abstract
The blood-brain barrier (BBB) is a complex and dynamic interface that regulates the exchange of molecules and cells between the blood and the central nervous system. It undergoes structural and functional changes during aging, which may compromise its integrity and contribute to the pathogenesis of neurodegenerative diseases. In recent years, advances in microscopy and high-throughput bioinformatics have allowed a more in-depth investigation of the aging mechanisms of BBB. This review summarizes age-related alterations of the BBB structure and function from six perspectives: endothelial cells, astrocytes, pericytes, basement membrane, microglia and perivascular macrophages, and fibroblasts, ranging from the molecular level to the human multi-system level. These basic components are essential for the proper functioning of the BBB. Recent imaging methods of BBB were also reviewed. Elucidation of age-associated BBB changes may offer insights into BBB homeostasis and may provide effective therapeutic strategies to protect it during aging.
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Affiliation(s)
- Yufan Cao
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Weihai Xu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qing Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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da Silva JF, Polk FD, Martin PE, Thai SH, Savu A, Gonzales M, Kath AM, Gee MT, Pires PW. Sex-specific mechanisms of cerebral microvascular BK Ca dysfunction in a mouse model of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.06.543962. [PMID: 37333104 PMCID: PMC10274786 DOI: 10.1101/2023.06.06.543962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
BACKGROUND Cerebral microvascular dysfunction and nitro-oxidative stress are present in patients with Alzheimer's disease (AD) and may contribute to disease progression and severity. Large conductance Ca 2+ -activated K + channels (BK Ca ) play an essential role in vasodilatory responses and maintenance of myogenic tone in resistance arteries. BK Ca impairment can lead to microvascular dysfunction and hemodynamic deficits in the brain. We hypothesized that reduced BK Ca function in cerebral arteries mediates microvascular and neurovascular responses in the 5x-FAD model of AD. METHODS BK Ca activity in the cerebral microcirculation was assessed by patch clamp electrophysiology and pressure myography, in situ Ca 2+ sparks by spinning disk confocal microscopy, hemodynamics by laser speckle contrast imaging. Molecular and biochemical analyses were conducted by affinity-purification assays, qPCR, Western blots and immunofluorescence. RESULTS We observed that pial arteries from 5-6 months-old male and female 5x-FAD mice exhibited a hyper-contractile phenotype than wild-type (WT) littermates, which was linked to lower vascular BK Ca activity and reduced open probability. In males, BK Ca dysfunction is likely a consequence of an observed lower expression of the pore-forming subunit BKα and blunted frequency of Ca 2+ sparks, which are required for BK Ca activity. However, in females, impaired BK Ca function is, in part, a consequence of reversible nitro-oxidative changes in the BK α subunit, which reduces its open probability and regulation of vascular tone. We further show that BK Ca function is involved in neurovascular coupling in mice, and its dysfunction is linked to neurovascular dysfunction in the model. CONCLUSION These data highlight the central role played by BK Ca in cerebral microvascular and neurovascular regulation, as well as sex-dependent mechanisms underlying its dysfunction in a mouse model of AD.
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Van NTH, Kim WK, Nam JH. Challenges in the Therapeutic Targeting of KCa Channels: From Basic Physiology to Clinical Applications. Int J Mol Sci 2024; 25:2965. [PMID: 38474212 PMCID: PMC10932353 DOI: 10.3390/ijms25052965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/23/2024] [Accepted: 01/25/2024] [Indexed: 03/14/2024] Open
Abstract
Calcium-activated potassium (KCa) channels are ubiquitously expressed throughout the body and are able to regulate membrane potential and intracellular calcium concentrations, thereby playing key roles in cellular physiology and signal transmission. Consequently, it is unsurprising that KCa channels have been implicated in various diseases, making them potential targets for pharmaceutical interventions. Over the past two decades, numerous studies have been conducted to develop KCa channel-targeting drugs, including those for disorders of the central and peripheral nervous, cardiovascular, and urinary systems and for cancer. In this review, we synthesize recent findings regarding the structure and activating mechanisms of KCa channels. We also discuss the role of KCa channel modulators in therapeutic medicine. Finally, we identify the major reasons behind the delay in bringing these modulators to the pharmaceutical market and propose new strategies to promote their application.
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Affiliation(s)
- Nhung Thi Hong Van
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea;
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
| | - Woo Kyung Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
- Department of Internal Medicine, Graduate School of Medicine, Dongguk University, Goyang 10326, Republic of Korea
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea;
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Republic of Korea
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Vinci M, Vitello GA, Greco D, Treccarichi S, Ragalmuto A, Musumeci A, Fallea A, Federico C, Calì F, Saccone S, Elia M. Next Generation Sequencing and Electromyography Reveal the Involvement of the P2RX6 Gene in Myopathy. Curr Issues Mol Biol 2024; 46:1150-1163. [PMID: 38392191 PMCID: PMC10887510 DOI: 10.3390/cimb46020073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 01/18/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024] Open
Abstract
Ion channelopathies result from impaired ion channel protein function, due to mutations affecting ion transport across cell membranes. Over 40 diseases, including neuropathy, pain, migraine, epilepsy, and ataxia, are associated with ion channelopathies, impacting electrically excitable tissues and significantly affecting skeletal muscle. Gene mutations affecting transmembrane ionic flow are strongly linked to skeletal muscle disorders, particularly myopathies, disrupting muscle excitability and contraction. Electromyography (EMG) analysis performed on a patient who complained of weakness and fatigue revealed the presence of primary muscular damage, suggesting an early-stage myopathy. Whole exome sequencing (WES) did not detect potentially causative variants in known myopathy-associated genes but revealed a novel homozygous deletion of the P2RX6 gene likely disrupting protein function. The P2RX6 gene, predominantly expressed in skeletal muscle, is an ATP-gated ion channel receptor belonging to the purinergic receptors (P2RX) family. In addition, STRING pathways suggested a correlation with more proteins having a plausible role in myopathy. No previous studies have reported the implication of this gene in myopathy. Further studies are needed on patients with a defective ion channel pathway, and the use of in vitro functional assays in suppressing P2RX6 gene expression will be required to validate its functional role.
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Affiliation(s)
| | | | | | | | | | | | | | - Concetta Federico
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy
| | | | - Salvatore Saccone
- Department of Biological, Geological and Environmental Sciences, University of Catania, Via Androne 81, 95124 Catania, Italy
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Ye YC, Chai SF, Li XR, Wu MN, Cai HY, Wang ZJ. Intermittent fasting and Alzheimer's disease-Targeting ketone bodies as a potential strategy for brain energy rescue. Metab Brain Dis 2024; 39:129-146. [PMID: 37823968 DOI: 10.1007/s11011-023-01288-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 09/01/2023] [Indexed: 10/13/2023]
Abstract
Alzheimer's disease (AD) lacks effective clinical treatments. As the disease progresses, the cerebral glucose hypometabolism that appears in the preclinical phase of AD gradually worsens, leading to increasingly severe brain energy disorders. This review analyzes the brain energy deficit in AD and its etiology, brain energy rescue strategies based on ketone intervention, the effects and mechanisms of IF, the differences in efficacy between IF and ketogenic diet and the duality of IF. The evidence suggests that brain energy deficits lead to the development and progression of AD pathology. IF, which improves brain energy impairments by promoting ketone metabolism, thus has good therapeutic potential for AD.
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Affiliation(s)
- Yu- Cai Ye
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Shi-Fan Chai
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Xin-Ru Li
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Mei-Na Wu
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Hong-Yan Cai
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Zhao-Jun Wang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China.
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Barber KR, Vizcarra VS, Zilch A, Majuta L, Diezel CC, Culver OP, Hughes BW, Taniguchi M, Streicher JM, Vanderah TW, Riegel AC. The Role of Ryanodine Receptor 2 in Drug-Associated Learning. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.03.560743. [PMID: 37873212 PMCID: PMC10592901 DOI: 10.1101/2023.10.03.560743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Type-2 ryanodine receptor (RyR2) ion channels facilitate the release of Ca 2+ from stores and serve an important function in neuroplasticity. The role for RyR2 in hippocampal-dependent learning and memory is well established and chronic hyperphosphorylation of RyR2 (RyR2P) is associated with pathological calcium leakage and cognitive disorders, including Alzheimer's disease. By comparison, little is known about the role of RyR2 in the ventral medial prefrontal cortex (vmPFC) circuitry important for working memory, decision making, and reward seeking. Here, we evaluated the basal expression and localization of RyR2 and RyR2P in the vmPFC. Next, we employed an operant model of sucrose, cocaine, or morphine self-administration (SA) followed by a (reward-free) recall test, to reengage vmPFC neurons and reactivate reward-seeking and re-evaluated the expression and localization of RyR2 and RyR2P in vmPFC. Under basal conditions, RyR2 was expressed in pyramidal cells but not regularly detected in PV/SST interneurons. On the contrary, RyR2P was rarely observed in PFC somata and was restricted to a different subcompartment of the same neuron - the apical dendrites of layer-5 pyramidal cells. Chronic SA of drug (cocaine or morphine) and nondrug (sucrose) rewards produced comparable increases in RyR2 protein expression. However, recalling either drug reward impaired the usual localization of RyR2P in dendrites and markedly increased its expression in somata immunoreactive for Fos, a marker of highly activated neurons. These effects could not be explained by chronic stress or drug withdrawal and instead appeared to require a recall experience associated with prior drug SA. In addition to showing the differential distribution of RyR2/RyR2P and affirming the general role of vmPFC in reward learning, this study provides information on the propensity of addictive drugs to redistribute RyR2P ion channels in a neuronal population engaged in drug-seeking. Hence, focusing on the early impact of addictive drugs on RyR2 function may serve as a promising approach to finding a treatment for substance use disorders.
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Fang X, Border JJ, Rivers PL, Zhang H, Williams JM, Fan F, Roman RJ. Amyloid beta accumulation in TgF344-AD rats is associated with reduced cerebral capillary endothelial Kir2.1 expression and neurovascular uncoupling. GeroScience 2023; 45:2909-2926. [PMID: 37326915 PMCID: PMC10643802 DOI: 10.1007/s11357-023-00841-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 05/25/2023] [Indexed: 06/17/2023] Open
Abstract
Alzheimer's disease (AD) exerts a tremendous socio-economic burden worldwide. Although reduced cerebral blood flow is an early and persistent symptom that precedes the loss of cognitive function in AD, the underlying molecular and cellular mechanisms remain unclear. The present study investigated whether capillary endothelial inward rectifier potassium 2 (Kir2.1) expression is reduced in TgF344-AD (AD) rats and contributes to neurovascular uncoupling and cognitive deficits in AD. Three- to fourteen-month-old AD rats expressing mutant human APP and PS1 and age-matched wild-type (WT) F344 rats were studied. AD rats exhibited higher amyloid beta (Aβ) expression in the brain as early as 3 months of age and amyloid plaques by 4 months of age. Functional hyperemic responses induced by whisker stimulation were impaired at 4 months of age, which were exacerbated in 6-month- and 14-month-old AD rats. The expression of Kir2.1 protein was significantly lower in the brains of 6-month-old AD versus WT rats, and Kir2.1 coverage was lower in the cerebral microvasculature of AD than in WT rats. Aβ1-42 reduced the Kir2.1 expression in cultured capillary endothelial cells. Cerebral parenchymal arterioles with attached capillaries exhibited a reduced vasodilator in response to 10 mM K+ applied to capillaries, and constricted less following administration of a Kir2.1 channel blocker, compared to WT vessels. These results indicate that capillary endothelial Kir2.1 expression is reduced and contributes to impaired functional hyperemia in AD rats at early ages, perhaps secondary to elevated Aβ expression.
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Affiliation(s)
- Xing Fang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Jane J Border
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Patrice L Rivers
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Huawei Zhang
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Jan Michael Williams
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA
| | - Fan Fan
- Department of Physiology, Medical College of Georgia, Augusta University, 1462 Laney Walker Blvd, Augusta, GA, 30912, USA.
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
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Taylor JL, Walsh KR, Mosneag IE, Danby TGE, Luka N, Chanda B, Schiessl I, Dunne RA, Hill-Eubanks D, Hennig GW, Allan SM, Nelson MT, Greenstein AS, Pritchard HAT. Uncoupling of Ca 2+ sparks from BK channels in cerebral arteries underlies hypoperfusion in hypertension-induced vascular dementia. Proc Natl Acad Sci U S A 2023; 120:e2307513120. [PMID: 37549299 PMCID: PMC10433456 DOI: 10.1073/pnas.2307513120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/14/2023] [Indexed: 08/09/2023] Open
Abstract
The deficit in cerebral blood flow (CBF) seen in patients with hypertension-induced vascular dementia is increasingly viewed as a therapeutic target for disease-modifying therapy. Progress is limited, however, due to uncertainty surrounding the mechanisms through which elevated blood pressure reduces CBF. To investigate this, we used the BPH/2 mouse, a polygenic model of hypertension. At 8 mo of age, hypertensive mice exhibited reduced CBF and cognitive impairment, mimicking the human presentation of vascular dementia. Small cerebral resistance arteries that run across the surface of the brain (pial arteries) showed enhanced pressure-induced constriction due to diminished activity of large-conductance Ca2+-activated K+ (BK) channels-key vasodilatory ion channels of cerebral vascular smooth muscle cells. Activation of BK channels by transient intracellular Ca2+ signals from the sarcoplasmic reticulum (SR), termed Ca2+ sparks, leads to hyperpolarization and vasodilation. Combining patch-clamp electrophysiology, high-speed confocal imaging, and proximity ligation assays, we demonstrated that this vasodilatory mechanism is uncoupled in hypertensive mice, an effect attributable to physical separation of the plasma membrane from the SR rather than altered properties of BK channels or Ca2+ sparks, which remained intact. This pathogenic mechanism is responsible for the observed increase in constriction and can now be targeted as a possible avenue for restoring healthy CBF in vascular dementia.
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Affiliation(s)
- Jade L. Taylor
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Katy R. Walsh
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Ioana-Emilia Mosneag
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Thea G. E. Danby
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Nadim Luka
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Bishal Chanda
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Ingo Schiessl
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Ross A. Dunne
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
| | - David Hill-Eubanks
- Department of Pharmacology, Larner College of Medicine, University of Vermont, Burlington, VT05405
| | - Grant W. Hennig
- Department of Pharmacology, Larner College of Medicine, University of Vermont, Burlington, VT05405
| | - Stuart M. Allan
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Division of Neuroscience, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, ManchesterM13 9PL, United Kingdom
| | - Mark T. Nelson
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Department of Pharmacology, Larner College of Medicine, University of Vermont, Burlington, VT05405
| | - Adam S. Greenstein
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
- Manchester University Teaching Hospitals National Health Service Foundation Trust, ManchesterM13 9PL, United Kingdom
| | - Harry A. T. Pritchard
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, ManchesterM13 9PL, United Kingdom
- Geoffrey Jefferson Brain Research Centre, The Manchester Academic Health Science Centre, Northern Care Alliance National Health Service Foundation Trust, University of Manchester, ManchesterM13 9PL, United Kingdom
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Ghosh S, Ali R, Verma S. Aβ-oligomers: A potential therapeutic target for Alzheimer's disease. Int J Biol Macromol 2023; 239:124231. [PMID: 36996958 DOI: 10.1016/j.ijbiomac.2023.124231] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/22/2023] [Accepted: 03/25/2023] [Indexed: 03/30/2023]
Abstract
The cascade of amyloid formation relates to multiple complex events at the molecular level. Previous research has established amyloid plaque deposition as the leading cause of Alzheimer's disease (AD) pathogenesis, detected mainly in aged population. The primary components of the plaques are two alloforms of amyloid-beta (Aβ), Aβ1-42 and Aβ1-40 peptides. Recent studies have provided considerable evidence contrary to the previous claim indicating that amyloid-beta oligomers (AβOs) as the main culprit responsible for AD-associated neurotoxicity and pathogenesis. In this review, we have discussed the primary features of AβOs, such as assembly formation, the kinetics of oligomer formation, interactions with various membranes/membrane receptors, the origin of toxicity, and oligomer-specific detection methods. Recently, the discovery of rationally designed antibodies has opened a gateway for using synthesized peptides as a grafting component in the complementarity determining region (CDR) of antibodies. Thus, the Aβ sequence motif or the complementary peptide sequence in the opposite strand of the β-sheet (extracted from the Protein Data Bank: PDB) helps design oligomer-specific inhibitors. The microscopic event responsible for oligomer formation can be targeted, and thus prevention of the overall macroscopic behaviour of the aggregation or the associated toxicity can be achieved. We have carefully reviewed the oligomer formation kinetics and associated parameters. Besides, we have depicted a thorough understanding of how the synthesized peptide inhibitors can impede the early aggregates (oligomers), mature fibrils, monomers, or a mixture of the species. The oligomer-specific inhibitors (peptides or peptide fragments) lack in-depth chemical kinetics and optimization control-based screening. In the present review, we have proposed a hypothesis for effectively screening oligomer-specific inhibitors using the chemical kinetics (determining the kinetic parameters) and optimization control strategy (cost-dependent analysis). Further, it may be possible to implement the structure-kinetic-activity-relationship (SKAR) strategy instead of structure-activity-relationship (SAR) to improve the inhibitor's activity. The controlled optimization of the kinetic parameters and dose usage will be beneficial for narrowing the search window for the inhibitors.
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Hakim MA, Behringer EJ. K IR channel regulation of electrical conduction along cerebrovascular endothelium: Enhanced modulation during Alzheimer's disease. Microcirculation 2023; 30:e12797. [PMID: 36577656 PMCID: PMC9885900 DOI: 10.1111/micc.12797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/22/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Endothelial cell (EC) coupling occurs through gap junctions and underlies cerebral blood flow regulation governed by inward-rectifying K+ (KIR ) channels. This study addressed effects of KIR channel activity on EC coupling before and during Alzheimer's disease (AD). METHODS Intact EC tubes (width: ~90-100 μm; length: ~0.5 mm) were freshly isolated from posterior cerebral arteries of young Pre-AD (1-3 months) and aged AD (13-18 months) male and female 3xTg-AD mice. Dual intracellular microelectrodes applied simultaneous current injections (±0.5-3 nA) and membrane potential (Vm ) recordings in ECs at distance ~400 μm. Elevated extracellular potassium ([K+ ]E ; 8-15 mmol/L; reference, 5 mmol/L) activated KIR channels. RESULTS Conducted Vm (∆Vm ) responses ranged from ~-30 to 30 mV in response to -3 to +3 nA (linear regression, R2 ≥ .99) while lacking rectification for charge polarity or axial direction of spread. Conduction slope decreased ~10%-20% during 15 mmol/L [K+ ]E in Pre-AD males and AD females. 15 mmol/L [K+ ]E decreased conduction by ~10%-20% at lower ∆Vm thresholds in AD animals (~±20 mV) versus Pre-AD (~±25 mV). AD increased conducted hyperpolarization by ~10%-15% during 8-12 mmol/L [K+ ]E . CONCLUSIONS Brain endothelial KIR channel activity modulates bidirectional spread of vasoreactive signals with enhanced regulation of EC coupling during AD pathology.
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Affiliation(s)
- Md A. Hakim
- Basic Sciences, Loma Linda University, Loma Linda, CA 92350, USA
| | - Erik J. Behringer
- Basic Sciences, Loma Linda University, Loma Linda, CA 92350, USA,Corresponding Author: Erik J. Behringer, Ph.D., Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, , tel: (909) 651-5334, fax: (909) 558-0119
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Modulation of L-type calcium channels in Alzheimer's disease: A potential therapeutic target. Comput Struct Biotechnol J 2022; 21:11-20. [PMID: 36514335 PMCID: PMC9719069 DOI: 10.1016/j.csbj.2022.11.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 11/28/2022] Open
Abstract
Calcium plays a fundamental role in various signaling pathways and cellular processes in the human organism. In the nervous system, voltage-gated calcium channels such as L-type calcium channels (LTCCs) are critical elements in mediating neurotransmitter release, synaptic integration and plasticity. Dysfunction of LTCCs has been implicated in both aging and Alzheimer's Disease (AD), constituting a key component of calcium hypothesis of AD. As such, LTCCs are a promising drug target in AD. However, due to their structural and functional complexity, the mechanisms by which LTCCs contribute to AD are still unclear. In this review, we briefly summarize the structure, function, and modulation of LTCCs that are the backbone for understanding pathological processes involving LTCCs. We suggest targeting molecular pathways up-regulating LTCCs in AD may be a more promising approach, given the diverse physiological functions of LTCCs and the ineffectiveness of LTCC blockers in clinical studies.
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Key Words
- AC, adenylyl cyclase
- AD, Alzheimer’s Disease
- AHP, afterhyperpolarization
- AR, adrenoceptor
- Aging
- Alzheimer’s disease
- Aβ, β-amyloid
- BIN1, bridging integrator 1
- BTZs, benzothiazepines
- CDF, calcium-dependent facilitation
- CDI, calcium-dependent inactivation
- CaMKII, calmodulin-dependent protein kinase II
- DHP, dihydropyridine
- L-type calcium channel
- LTCC, L-type calcium channels
- LTD, long-term depression
- LTP, long-term potentiation
- NFT, neurofibrillary tangles
- NMDAR, N-methyl-D-aspartate receptor
- PAA, phenylalkylamines
- PKA, protein kinase A
- PKC, protein kinase C
- PKG, protein kinase G
- SFK, Src family kinase
- Tau
- VSD, voltage sensing domain
- β-Amyloid
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Wilson C, McCarron JG, Lee MD. William Bayliss and the enduring fascination of myogenic tone. J Physiol 2022; 600:4043-4044. [PMID: 35848099 DOI: 10.1113/jp282890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 07/14/2022] [Indexed: 11/08/2022] Open
Affiliation(s)
- Calum Wilson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - John G McCarron
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Matthew D Lee
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
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