scholarly journals Equilibrative nucleoside transporter 1 inhibition rescues energy dysfunction and pathology in a model of tauopathy

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Ching-Pang Chang ◽  
Ya-Gin Chang ◽  
Pei-Yun Chuang ◽  
Thi Ngoc Anh Nguyen ◽  
Kuo-Chen Wu ◽  
...  

AbstractTau pathology is instrumental in the gradual loss of neuronal functions and cognitive decline in tauopathies, including Alzheimer’s disease (AD). Earlier reports showed that adenosine metabolism is abnormal in the brain of AD patients while consequences remained ill-defined. Herein, we aimed at investigating whether manipulation of adenosine tone would impact Tau pathology, associated molecular alterations and subsequent neurodegeneration. We demonstrated that treatment with an inhibitor (J4) of equilibrative nucleoside transporter 1 (ENT1) exerted beneficial effects in a mouse model of Tauopathy. Treatment with J4 not only reduced Tau hyperphosphorylation but also rescued memory deficits, mitochondrial dysfunction, synaptic loss, and abnormal expression of immune-related gene signatures. These beneficial effects were particularly ascribed to the ability of J4 to suppress the overactivation of AMPK (an energy reduction sensor), suggesting that normalization of energy dysfunction mitigates neuronal dysfunctions in Tauopathy. Collectively, these data highlight that targeting adenosine metabolism is a novel strategy for tauopathies.

2020 ◽  
Author(s):  
Ching-Pang Chang ◽  
Ya-Gin Chang ◽  
Pei-Yun Chuang ◽  
Thi Ngoc Anh Nguyen ◽  
Fang-Yi Chou ◽  
...  

AbstractTau hyperphosphorylation favors the formation of neurofibrillary tangles and triggers the gradual loss of neuronal functions in tauopathies, including Alzheimer’s disease. Herein, we demonstrated that chronic treatment with an inhibitor (J4) of equilibrative nucleoside transporter 1 (ENT1), which plays a critical role in controlling adenosine homeostasis and purine metabolism in the brain, exerted beneficial effects in a mouse model of tauopathy (Thy-Tau22, Tau22). Chronic treatment with J4 improved spatial memory deficits, mitochondrial dysfunction, synaptic plasticity impairment, and gliosis. Immunofluorescence assays showed that J4 not only reduced Tau hyperphosphorylation but also normalized the reduction in mitochondrial mass and suppressed the abnormal activation of AMP-activated protein kinase (AMPK), a pathogenic feature that is also observed in the brains of patients with tauopathies. Given that AMPK is an important energy sensor, our findings suggest that energy dysfunction is associated with tauopathy and that J4 may exert its protective effect by improving energy homeostasis. Bulk RNA-seq analysis revealed that J4 also mitigated immune signature associated with Tau pathology including C1q upregulation and A1 astrocyte markers. Collectively, our findings suggest that identifying strategies for normalizing energy and neuroimmune dysfunctions in tauopathies through adenosinergic signaling modulation may pave the way for the development of treatments for Alzheimer’s disease.


2021 ◽  
Author(s):  
Weidong Fei ◽  
Yunchun Zhao ◽  
Xiaodong Wu ◽  
Dongli Sun ◽  
Yao Yao ◽  
...  

Abstract The gestational trophoblastic tumor seriously endangers child productive needs and the health of women in childbearing age. Nanodrug-based therapy mediated by transporters provides novel strategy for the treatment of trophoblastic tumors. Focus on the overexpressed human equilibrative nucleoside transporter 1 (ENT1) on the membrane of choriocarcinoma cells (JEG-3), the cytarabine (Cy, a substrate of ENT1) grafted liposome (Cy-Lipo) was introduced for targeted delivery of methotrexate (Cy-Lipo@MTX) for choriocarcinoma therapy in this study. The ENT1 has high affinity for Cy-Lipo and can mediate the endocytosis of the designed nanovehicles into JEG-3 cells. The ENT1 protein maintains its transporting function through circulation and regeneration during endocytosis. Therefore, Cy-Lipo-based formulations achieved high tumor accumulation and retention in pharmacokinetic and distribution studies. More importantly, the designed Cy-lipid conjugation exhibited a synergistic therapeutic effect on choriocarcinoma. Finally, Cy-Lipo@MTX exerts an extremely powerful anti-choriocarcinoma effect with fewer side effects. This study suggests that the overexpressed ENT1 on choriocarcinoma cells holds a great potential to be a high-efficiency target for the rational design of active targeting nanotherapeutics.


ISRN Oncology ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Shuji Komori ◽  
Shinji Osada ◽  
Kazuhiro Yoshida

5-fluorouracil (5-FU) is widely used in chemotherapy for gastric and colorectal cancer, but gemcitabine (GEM), and not 5-FU, is approved as a standard drug for use in pancreatic cancer. Interindividual variation in the enzyme activity of the GEM metabolic pathway can affect the extent of GEM metabolism and the efficacy of GEM chemotherapy. Human equilibrative nucleoside transporter 1 (hENT1) is recognized as a major transporter of GEM into cells. In addition, a factor that activates hENT1 is the inhibition of thymidylate synthase (TS), one of the 5-FU metabolic enzymes; TS inhibition mediates depleting intracellular nucleotide pools, resulting in the activation of the salvage pathway mediated through hENT1. In this paper, the role of 5-FU in GEM-based chemotherapy for pancreatic cancer is discussed with special emphasis on enzymes involved in the 5-FU and GEM metabolic pathways and in the correlation between GEM responsiveness and the expression of 5-FU and GEM metabolic enzymes.


2019 ◽  
Vol 25 (23) ◽  
pp. 2555-2568 ◽  
Author(s):  
Rajeev Taliyan ◽  
Sarathlal K. Chandran ◽  
Violina Kakoty

Neurodegenerative disorders are the most devastating disorder of the nervous system. The pathological basis of neurodegeneration is linked with dysfunctional protein trafficking, mitochondrial stress, environmental factors and aging. With the identification of insulin and insulin receptors in some parts of the brain, it has become evident that certain metabolic conditions associated with insulin dysfunction like Type 2 diabetes mellitus (T2DM), dyslipidemia, obesity etc., are also known to contribute to neurodegeneration mainly Alzheimer’s Disease (AD). Recently, a member of the fibroblast growth factor (FGF) superfamily, FGF21 has proved tremendous efficacy in diseases like diabetes mellitus, obesity and insulin resistance (IR). Increased levels of FGF21 have been reported to exert multiple beneficial effects in metabolic syndrome. FGF21 receptors are present in certain areas of the brain involved in learning and memory. However, despite extensive research, its function as a neuroprotectant in AD remains elusive. FGF21 is a circulating endocrine hormone which is mainly secreted by the liver primarily in fasting conditions. FGF21 exerts its effects after binding to FGFR1 and co-receptor, β-klotho (KLB). It is involved in regulating energy via glucose and lipid metabolism. It is believed that aberrant FGF21 signalling might account for various anomalies like neurodegeneration, cancer, metabolic dysfunction etc. Hence, this review will majorly focus on FGF21 role as a neuroprotectant and potential metabolic regulator. Moreover, we will also review its potential as an emerging candidate for combating metabolic stress induced neurodegenerative abnormalities.


2019 ◽  
Vol 19 (3) ◽  
pp. 316-325
Author(s):  
Mahdi Goudarzvand ◽  
Yaser Panahi ◽  
Reza Yazdani ◽  
Hosein Miladi ◽  
Saeed Tahmasebi ◽  
...  

Objective: Experimental autoimmune encephalomyelitis (EAE) is a widely used model for multiple sclerosis. The present study has been designed to compare the efficiencies of oral and intraperitoneal (IP) administration of D-aspartate (D-Asp) on the onset and severity of EAE, the production of neurosteroids, and the expression of neurosteroid receptors and inflammatory mediators in the brain of EAE mice. Methods: In this study, EAE was induced in C57BL/6 mice treated with D-Asp orally (D-Asp-Oral) or by IP injection (D-Asp-IP). On the 20th day, brains (cerebrums) and cerebellums of mice were evaluated by histological analyses. The brains of mice were analyzed for: 1) Neurosteroid (Progesterone, Testosterone, 17β-estradiol) concentrations; 2) gene expressions of cytokines and neurosteroid receptors by reverse transcription polymerase chain reaction, and 3) quantitative determination of D-Asp using liquid chromatography-tandem mass spectrometry. Further, some inflammatory cytokines and matrix metalloproteinase-2 (MMP-2) were identified in the mouse serum using enzyme-linked immunosorbent assay kits. Results: Our findings demonstrated that after D-Asp was administered, it was taken up and accumulated within the brain. Further, IP injection of D-Asp had more beneficial effects on EAE severity than oral gavage. The concentration of the testosterone and 17β-estradiol in D-Asp-IP group was significantly higher than that of the control group. There were no significant differences in the gene expression of cytokine and neurosteroid receptors between control, D-Asp-IP, and D-Asp-Oral groups. However, IP treatment with D-Asp significantly reduced C-C motif chemokine ligand 2 and MMP-2 serum levels compared to control mice. Conclusion: IP injection of D-Asp had more beneficial effects on EAE severity, neurosteroid induction and reduction of inflammatory mediators than oral gavage.


2020 ◽  
Vol 10 (4) ◽  
pp. 355-363
Author(s):  
Mohaddese Mahboubi ◽  
Leila Mohammad Taghizadeh Kashani

Background: In Iranian Traditional Medicine, Boswellia serrata oleo-gum resins were used for the treatment of "Nisyan". "Nisyan" was equivalent to a reduction of memory or forgetfulness. Objective: This review evaluates the traditional believes of B. serrata and memory and its effectiveness on memory loss. Methods: We extracted all traditional and modern information on B. serrata oleo-gum resin preparations and memory from scientific accessible resources (Google Scholar, PubMed, Springer, Science direct, Wiley), non-accessible resources and traditional books. Results: In traditional manuscripts, "Nisyan" is equal to memory loss in modern medicine and was believed to happen as the result of pouring the waste materials into the brain. Traditional practitioners treated "Nisyan" by inhibition of waste production in the brain or cleaning the brain from waste materials. They recommended using the plants with warming effects on the brain. It was believed that B. serrata had beneficial effects on memory functions and its memory enhancing effects have been the subject of pharmacological and clinical trial studies. Conclusion: Despite some documents on the effectiveness of B. serrata oleo-gum-resin on memory functions, there is gap between these investigations, especially in pregnant and nursing mothers. More investigations with large clinical trials are required to complete flaw in order to improve the therapeutic applications of B. serrata on memory functions.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Conor McQuaid ◽  
Molly Brady ◽  
Rashid Deane

Abstract Background SARS-CoV-2, a coronavirus (CoV), is known to cause acute respiratory distress syndrome, and a number of non-respiratory complications, particularly in older male patients with prior health conditions, such as obesity, diabetes and hypertension. These prior health conditions are associated with vascular dysfunction, and the CoV disease 2019 (COVID-19) complications include multiorgan failure and neurological problems. While the main route of entry into the body is inhalation, this virus has been found in many tissues, including the choroid plexus and meningeal vessels, and in neurons and CSF. Main body We reviewed SARS-CoV-2/COVID-19, ACE2 distribution and beneficial effects, the CNS vascular barriers, possible mechanisms by which the virus enters the brain, outlined prior health conditions (obesity, hypertension and diabetes), neurological COVID-19 manifestation and the aging cerebrovascualture. The overall aim is to provide the general reader with a breadth of information on this type of virus and the wide distribution of its main receptor so as to better understand the significance of neurological complications, uniqueness of the brain, and the pre-existing medical conditions that affect brain. The main issue is that there is no sound evidence for large flux of SARS-CoV-2 into brain, at present, compared to its invasion of the inhalation pathways. Conclusions While SARS-CoV-2 is detected in brains from severely infected patients, it is unclear on how it gets there. There is no sound evidence of SARS-CoV-2 flux into brain to significantly contribute to the overall outcomes once the respiratory system is invaded by the virus. The consensus, based on the normal route of infection and presence of SARS-CoV-2 in severely infected patients, is that the olfactory mucosa is a possible route into brain. Studies are needed to demonstrate flux of SARS-CoV-2 into brain, and its replication in the parenchyma to demonstrate neuroinvasion. It is possible that the neurological manifestations of COVID-19 are a consequence of mainly cardio-respiratory distress and multiorgan failure. Understanding potential SARS-CoV-2 neuroinvasion pathways could help to better define the non-respiratory neurological manifestation of COVID-19.


2021 ◽  
Vol 11 (15) ◽  
pp. 7120
Author(s):  
Mirko Pesce ◽  
Irene La Fratta ◽  
Teresa Paolucci ◽  
Alfredo Grilli ◽  
Antonia Patruno ◽  
...  

The beneficial effects of exercise on the brain are well known. In general, exercise offers an effective way to improve cognitive function in all ages, particularly in the elderly, who are considered the most vulnerable to neurodegenerative disorders. In this regard, myokines, hormones secreted by muscle in response to exercise, have recently gained attention as beneficial mediators. Irisin is a novel exercise-induced myokine, that modulates several bodily processes, such as glucose homeostasis, and reduces systemic inflammation. Irisin is cleaved from fibronectin type III domain containing 5 (FNDC5), a transmembrane precursor protein expressed in muscle under the control of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). The FNDC5/irisin system is also expressed in the hippocampus, where it stimulates the expression of the neurotrophin brain-derived neurotrophic factor in this area that is associated with learning and memory. In this review, we aimed to discuss the role of irisin as a key mediator of the beneficial effects of exercise on synaptic plasticity and memory in the elderly, suggesting its roles within the main promoters of the beneficial effects of exercise on the brain.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan Kou ◽  
Chunmei Lan ◽  
Yingying Zhang ◽  
Qianqian Wang ◽  
Feng Zhou ◽  
...  

AbstractIntranasal oxytocin exerts wide-ranging effects on socioemotional behavior and is proposed as a potential therapeutic intervention in psychiatric disorders. However, following intranasal administration, oxytocin could penetrate directly into the brain or influence its activity via increased peripheral concentrations crossing the blood–brain barrier or influencing vagal projections. In the current randomized, placebo-controlled, pharmaco-imaging clinical trial we investigated effects of 24IU oral (lingual) oxytocin spray, restricting it to peripherally mediated blood-borne and vagal effects, on responses to face emotions in 80 male subjects and compared them with 138 subjects treated intranasally with 24IU. Oral, but not intranasal oxytocin administration increased both arousal ratings for faces and associated brain reward responses, the latter being partially mediated by blood concentration changes. Furthermore, while oral oxytocin increased amygdala and arousal responses to face emotions, after intranasal administration they were decreased. Thus, oxytocin can produce markedly contrasting motivational effects in relation to socioemotional cues when it influences brain function via different routes. These findings have important implications for future therapeutic use since administering oxytocin orally may be both easier and have potentially stronger beneficial effects by enhancing responses to emotional cues and increasing their associated reward.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. Horvath ◽  
G. Kis ◽  
G. Kekesi ◽  
A. Büki ◽  
L. G. Adlan ◽  
...  

AbstractThe low efficacy of antipsychotic drugs (e.g., clozapine) for negative symptoms and cognitive impairment has led to the introduction of adjuvant therapies. Because previous data suggest the procognitive potential of the antidiabetic drug metformin, this study aimed to assess the effects of chronic clozapine and metformin oral administration (alone and in combination) on locomotor and exploratory activities and cognitive function in a reward-based test in control and a schizophrenia-like animal model (Wisket rats). As impaired dopamine D1 receptor (D1R) function might play a role in the cognitive dysfunctions observed in patients with schizophrenia, the second goal of this study was to determine the brain-region-specific D1R-mediated signaling, ligand binding, and mRNA expression. None of the treatments affected the behavior of the control animals significantly; however, the combination treatment enhanced D1R binding and activation in the cerebral cortex. The Wisket rats exhibited impaired motivation, attention, and cognitive function, as well as a lower level of cortical D1R binding, signaling, and gene expression. Clozapine caused further deterioration of the behavioral parameters, without a significant effect on the D1R system. Metformin blunted the clozapine-induced impairments, and, similarly to that observed in the control animals, increased the functional activity of D1R. This study highlights the beneficial effects of metformin (at the behavioral and cellular levels) in blunting clozapine-induced adverse effects.


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