Rectifying Attenuated Store-Operated Calcium Entry as a Therapeutic Approach for Alzheimer’s Disease

2021 ◽  
Vol 17 (12) ◽  
pp. 1072-1087
Author(s):  
Alexis S. Huang ◽  
Benjamin C.K. Tong ◽  
Aston J. Wu ◽  
Xiaotong Chen ◽  
Sravan G. Sreenivasmurthy ◽  
...  

: Alzheimer’s disease (AD) is the most common neurodegenerative disorder. Although the pathological hallmarks of AD have been identified, the derived therapies cannot effectively slow down or stop disease progression; hence, it is likely that other pathogenic mechanisms are involved in AD pathogenesis. Intracellular calcium (Ca2+) dyshomeostasis has been consistently observed in AD patients and numerous AD models and may emerge prior to the development of amyloid plaques and neurofibrillary tangles. Thus, intracellular Ca2+ disruptions are believed to play an important role in AD development and could serve as promising therapeutic intervention targets. : One of the disrupted intracellular Ca2+ signaling pathways manifested in AD is attenuated storeoperated Ca2+ entry (SOCE). SOCE is an extracellular Ca2+ entry mechanism mainly triggered by intracellular Ca2+ store depletion. Maintaining normal SOCE function not only provides a means for the cell to replenish ER Ca2+ stores but also serves as a cellular signal that maintains normal neuronal functions, including excitability, neurogenesis, neurotransmission, synaptic plasticity, and gene expression. However, normal SOCE function is diminished in AD, resulting in disrupted neuronal spine stability and synaptic plasticity and the promotion of amyloidogenesis. Mounting evidence suggests that rectifying diminished SOCE in neurons may intervene with the progression of AD. In this review, the mechanisms of SOCE disruption and the associated pathogenic impacts on AD will be discussed. We will also highlight the potential therapeutic targets or approaches that may help ameliorate SOCE deficits for AD treatment.

2021 ◽  
pp. 1-16
Author(s):  
Wei Wei ◽  
Yinghua Liu ◽  
Chunling Dai ◽  
Narjes Baazaoui ◽  
Yunn-Chyn Tung ◽  
...  

Background: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by impairments in synaptic plasticity and cognitive performance. Cognitive dysfunction and loss of neuronal plasticity are known to begin decades before the clinical diagnosis of the disease. The important influence of congenital genetic mutations on the early development of AD provides a novel opportunity to initiate treatment during early development to prevent the Alzheimer-like behavior and synaptic dysfunction. Objective: To explore strategies for early intervention to prevent Alzheimer’s disease. Methods: In the present study, we investigated the effect of treatment during early development with a ciliary neurotrophic factor (CNTF) derived peptidergic compound, P021 (Ac-DGGLAG-NH2) on cognitive function and synaptic plasticity in 3xTg-AD transgenic mouse model of AD. 3xTg-AD and genetic background-matched wild type female mice were treated from birth to postnatal day 120 with P021 in diet or as a control with vehicle diet, and cognitive function and molecular markers of neuroplasticity were evaluated. Results: P021 treatment during early development prevented cognitive impairment and increased expressions of pCREB and BDNF that activated downstream various signaling cascades such as PLC/PKC, MEK/ERK and PI3K/Akt, and ameliorated synaptic protein deficit in 4-month-old 3xTg-AD mice. Conclusion: These findings indicate that treatment with the neurotrophic peptide mimetic such as P021 during early development can be an effective therapeutic strategy to rescue synaptic deficit and cognitive impairment in familial AD and related tauopathies.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Tan Sook Ling ◽  
Shanthini Chandrasegaran ◽  
Low Zhi Xuan ◽  
Tong Li Suan ◽  
Elaine Elaine ◽  
...  

Alzheimer’s disease is a neurodegenerative disorder that is caused by the accumulation of beta-amyloid plaques in the brain. Currently, there is no definitive cure available to treat Alzheimer’s disease. The available medication in the market has the ability to only slow down its progression. However, nanotechnology has shown its superiority that can be applied for medical usage and it has a great potential in the therapy of Alzheimer’s disease, specifically in the disease diagnosis and providing an alternative approach to treat Alzheimer’s disease. This is done by increasing the efficiency of drug delivery by penetrating and overcoming the blood-brain barrier. Having said that, there are limitations that need to be further investigated and researched in order to minimize the adverse effects and potential toxicity and to improve drug bioavailability. The recent advances in the treatment of Alzheimer’s disease using nanotechnology include the regeneration of stem cells, nanomedicine, and neuroprotection. In this review, we will discuss the advancement of nanotechnology which helps in the diagnosis and treatment of neurodegenerative disorders such as Alzheimer’s disease as well as its challenges.


2020 ◽  
Vol 78 (4) ◽  
pp. 1345-1361
Author(s):  
Akriti Srivastava ◽  
Brati Das ◽  
Annie Y. Yao ◽  
Riqiang Yan

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the presence of neuritic plaques and neurofibrillary tangles. The impaired synaptic plasticity and dendritic loss at the synaptic level is an early event associated with the AD pathogenesis. The abnormal accumulation of soluble oligomeric amyloid-β (Aβ), the major toxic component in amyloid plaques, is viewed to trigger synaptic dysfunctions through binding to several presynaptic and postsynaptic partners and thus to disrupt synaptic transmission. Over time, the abnormalities in neural transmission will result in cognitive deficits, which are commonly manifested as memory loss in AD patients. Synaptic plasticity is regulated through glutamate transmission, which is mediated by various glutamate receptors. Here we review recent progresses in the study of metabotropic glutamate receptors (mGluRs) in AD cognition. We will discuss the role of mGluRs in synaptic plasticity and their modulation as a possible strategy for AD cognitive improvement.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Donna M. Wilcock

Alzheimer's disease (AD) is a complex, neurodegenerative disorder characterized by the presence of amyloid plaques and neurofibrillary tangles in the brain. Glial cells, particularly microglial cells, react to the presence of the amyloid plaques and neurofibrillary tangles producing an inflammatory response. While once considered immunologically privileged due to the blood-brain barrier, it is now understood that the glial cells of the brain are capable of complex inflammatory responses. This paper will discuss the published literature regarding the diverse roles of neuroinflammation in the modulation of AD pathologies. These data will then be related to the well-characterized macrophage phenotypes. The conclusion is that the glial cells of the brain are capable of a host of macrophage responses, termed M1, M2a, M2b, and M2c. The relationship between these states and AD pathologies remains relatively understudied, yet published data using various inflammatory stimuli provides some insight. It appears that an M1-type response lowers amyloid load but exacerbates neurofibrillary tangle pathology. In contrast, M2a is accompanied by elevated amyloid load and appears to ameliorate, somewhat, neurofibrillary pathology. Overall, it is clear that more focused, cause-effect studies need to be performed to better establish how each inflammatory state can modulate the pathologies of AD.


2021 ◽  
Vol 22 (13) ◽  
pp. 6841
Author(s):  
Jaydeep Roy ◽  
Ka Chun Tsui ◽  
Jonah Ng ◽  
Man-Lung Fung ◽  
Lee Wei Lim

Alzheimer’s disease is a neurodegenerative disorder associated with age, and is characterized by pathological markers such as amyloid-beta plaques and neurofibrillary tangles. Symptoms of AD include cognitive impairments, anxiety and depression. It has also been shown that individuals with AD have impaired neurotransmission, which may result from the accumulation of amyloid plaques and neurofibrillary tangles. Preclinical studies showed that melatonin, a monoaminergic neurotransmitter released from the pineal gland, is able to ameliorate AD pathologies and restore cognitive impairments. Theoretically, inhibition of the pathological progression of AD by melatonin treatment should also restore the impaired neurotransmission. This review aims to explore the impact of AD on neurotransmission, and whether and how melatonin can enhance neurotransmission via improving AD pathology.


2021 ◽  
Vol 27 ◽  
Author(s):  
Md. Sohanur Rahman ◽  
Md. Sahab Uddin ◽  
Md. Ataur Rahman ◽  
Md. Samsuzzaman ◽  
Tapan Behl ◽  
...  

: Monoamine oxidases (MAOs) are a family of flavin adenine dinucleotide-dependent enzymes that exert a crucial role in the metabolism of neurotransmitters of the central nervous system. The impaired function of MAOs is associated with copious brain diseases. The alteration of monoamine metabolism is a characteristics feature of aging. MAO plays a crucial role in the pathogenesis of Alzheimer’s disease (AD) – a progressive neurodegenerative disorder associated with an excessive accumulation of amyloid-beta (Aβ) peptide and neurofibrillary tangles (NFTs). Activated MAO has played a critical role in the development of amyloid plaques from Aβ, as well as the formation of the NFTs. In the brain, MAO mediated metabolism of monoamines is the foremost source of reactive oxygen species formation. The elevated level of MAO-B expression in astroglia has been reported in the AD brains adjacent to amyloid plaques. Increased MAO-B activity in the cortical and hippocampal regions is associated with AD. This review describes the pathogenic mechanism of MAOs in aging as well as the development and propagation of Alzheimer’s pathology.


Author(s):  
Md. Sahab Uddin ◽  
Md. Tanvir Kabir ◽  
Abdullah Al Mamun ◽  
Tapan Behl ◽  
Rasha A. Mansouri ◽  
...  

: Alzheimer's disease (AD) is a chronic neurodegenerative disorder that is marked by cognitive dysfunctions and existence of neuropathological hallmarks such as amyloid plaques, and neurofibrillary tangles. It has been observed that a persistent immune response in the brain has appeared as another neuropathological hallmark in AD. The persistent activation of the microglia, the brain’s resident macrophages, and other immune cells has been shown to aggravate both tau and amyloid pathology and may consider as a connection in the AD pathogenesis. However, the basic mechanisms that link immune responses in the pathogenesis of AD are unclear until now since the process of neuroinflammation can have either a harmful or favorable effect on AD, according to the phase of the disease. Numerous researches recommend that nutritional fruits, as well as vegetables, possess neurodefensive properties against the detrimental effects of neuroinflammation and aging. Moreover, these effects are controlled by diverse phytochemical compounds that are found in plants and demonstrate anti-inflammatory, neuroprotective as well as other beneficial actions. In this review, we focus on the link of neuroinflammation in AD as well as highlight the probable mechanisms of alkaloidal phytochemicals to combat neuroinflammatory aspect of AD.


2020 ◽  
Vol 35 ◽  
pp. 153331752095304
Author(s):  
Mark Maskery ◽  
Elizabeth Mary Goulding ◽  
Simon Gengler ◽  
Josefine Ulrikke Melchiorsen ◽  
Mette Marie Rosenkilde ◽  
...  

Alzheimer’s disease (AD) is a neurodegenerative disorder for which there is no cure. Here, we test a dual GLP-1/GIP receptor agonist (DA4-JC) that has a cell penetrating sequence added to enhance blood-brain barrier penetration. We show in a receptor activity study that DA4-JC has balanced activity on both GLP-1 and GIP receptors but not on GLP-2 or Glucagon receptors. A dose-response study in the APP/PS1 mouse model of AD showed both a dose-dependent drug effect on the inflammation response and the reduction of amyloid plaques in the brain. When comparing DA4-JC with the GLP-1 analogue liraglutide at equal doses of 10nmol/kg bw ip. once-daily for 8 weeks, DA4-JC was more effective in reversing memory loss, enhancing synaptic plasticity (LTP) in the hippocampus, reducing amyloid plaques and lowering pro-inflammatory cytokine levels in the brain. The results suggest that DA4-JC may be a novel treatment for AD.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Mudan Cai ◽  
Jun-Hwan Lee ◽  
Eun Jin Yang

Abstract Background Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive loss of cognitive abilities and memory leading to dementia. Electroacupuncture (EA) is a complementary alternative medicine approach, applying an electrical current to acupuncture points. In clinical and animal studies, EA causes cognitive improvements in AD and vascular dementia. However, EA-induced changes in cognition and microglia-mediated amyloid β (Aβ) degradation have not been determined yet in AD animals. Therefore, this study investigated the EA-induced molecular mechanisms causing cognitive improvement and anti-inflammatory activity in five familial mutation (5XFAD) mice, an animal model of AD. Methods 5XFAD mice were bilaterally treated with EA at the Taegye (KI3) acupoints three times per week for 2 weeks. To evaluate the effects of EA treatment on cognitive functions, novel object recognition and Y-maze tests were performed with non-Tg, 5XFAD (Tg), and EA-treated 5XFAD (Tg + KI3) mice. To examine the molecular mechanisms underlying EA effects, western blots, immunohistochemistry, and micro-positron emission tomography scans were performed. Furthermore, we studied synapse ultrastructures with transmission electron microscopy and used electrophysiology to investigate EA effects on synaptic plasticity in 5XFAD mice. Results EA treatment significantly improved working memory and synaptic plasticity, alleviated neuroinflammation, and reduced ultrastructural degradation of synapses via upregulation of synaptophysin and postsynaptic density-95 protein in 5XFAD mice. Furthermore, microglia-mediated Aβ deposition was reduced after EA treatment and coincided with a reduction in amyloid precursor protein. Conclusions Our findings demonstrate that EA treatment ameliorates cognitive impairment via inhibition of synaptic degeneration and neuroinflammation in a mouse model of AD.


2021 ◽  
Vol 72 (2) ◽  
pp. 5-10
Author(s):  
Violeta Jovanović ◽  
Jelica Despotović ◽  
Mario Balo ◽  
Ivan Zaletel ◽  
Sanja Despotović ◽  
...  

Introduction: Alzheimer's disease is the most common neurodegenerative disorder, characterized by the formation of amyloid plaques and the neurofibrillary tangles in the brain of an ill person, leading to neuronal damage and loss. Activation of astrocytes and astrogliosis occurs along with this process. Due to ethical limitations in working with human tissue, numerous transgenic animal models have been developed to study the pathogenesis of these processes. Early Ab deposition is observed in the cortex and the hippocampus. Aim: This study aimed to determine the difference in the presence of GFAP positive cells in the hippocampus between transgenic 5xFAD mice aged 36 weeks and their corresponding controls. Material and Methods: The 5xFAD mice model of Alzheimer's disease was used, characterized by early formation of amyloid plaques but without the presence of neurofibrillar tangles. Transgenic and control animals were sacrificed at 36 weeks of age. The visualization of GFAP-positive cells in the hippocampus of their brains was done by using immunohistochemistry and antibody for glial fibrillary acidic protein - GFAP, the major marker of astrocytes. Quantification of immuno-reactivity was done by using the Icy software system. Results: There was a statistically significant difference in the expression of GFAP in the dentate gyrus and the granular zone of the hippocampus between the transgenic and control group at 36 weeks of age, while the significant change in the CA1-3 regions was not observed between investigated groups. Conclusion: Obtained results confirm the involvement of astrogliosis in the pathophysiology of Alzheimer's disease and indicate an earlier occurrence of astrogliosis in the dentate gyrus and granular zone, in relation to other regions of the hippocampus, in the 36-week-old 5xFAD mice.


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