scholarly journals The Anti-Diabetic Drug Metformin Rescues Aberrant Mitochondrial Activity and Restrains Oxidative Stress in a Female Mouse Model of Rett Syndrome

2020 ◽  
Vol 9 (6) ◽  
pp. 1669 ◽  
Author(s):  
Ilaria Zuliani ◽  
Chiara Urbinati ◽  
Daniela Valenti ◽  
Maria Cristina Quattrini ◽  
Vanessa Medici ◽  
...  

Metformin is the first-line therapy for diabetes, even in children, and a promising attractive candidate for drug repurposing. Mitochondria are emerging as crucial targets of metformin action both in the periphery and in the brain. The present study evaluated whether treatment with metformin may rescue brain mitochondrial alterations and contrast the increased oxidative stress in a validated mouse model of Rett syndrome (RTT), a rare neurologic disorder of monogenic origin characterized by severe behavioral and physiological symptoms. No cure for RTT is available. In fully symptomatic RTT mice (12 months old MeCP2-308 heterozygous female mice), systemic treatment with metformin (100 mg/kg ip for 10 days) normalized the reduced mitochondrial ATP production and ATP levels in the whole-brain, reduced brain oxidative damage, and rescued the increased production of reactive oxidizing species in blood. A 10-day long treatment with metformin also boosted pathways related to mitochondrial biogenesis and antioxidant defense in the brain of metformin-treated RTT mice. This treatment regimen did not improve general health status and motor dysfunction in RTT mice at an advanced stage of the disease. Present results provide evidence that systemic treatment with metformin may represent a novel, repurposable therapeutic strategy for RTT.

Antioxidants ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 16 ◽  
Author(s):  
Flávia Póvoa da Costa ◽  
Bruna Puty ◽  
Lygia S. Nogueira ◽  
Geovanni Pereira Mitre ◽  
Sávio Monteiro dos Santos ◽  
...  

Piceatannol is a resveratrol metabolite that is considered a potent antioxidant and cytoprotector because of its high capacity to chelate/sequester reactive oxygen species. In pathogenesis of periodontal diseases, the imbalance of reactive oxygen species is closely related to the disorder in the cells and may cause changes in cellular metabolism and mitochondrial activity, which is implicated in oxidative stress status or even in cell death. In this way, this study aimed to evaluate piceatannol as cytoprotector in culture of human periodontal ligament fibroblasts through in vitro analyses of cell viability and oxidative stress parameters after oxidative stress induced as an injury simulator. Fibroblasts were seeded and divided into the following study groups: control, vehicle, control piceatannol, H2O2 exposure, and H2O2 exposure combined with the maintenance in piceatannol ranging from 0.1 to 20 μM. The parameters analyzed following exposure were cell viability by trypan blue exclusion test, general metabolism status by the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method, mitochondrial activity through the ATP production, total antioxidant capacity, and reduced gluthatione. Piceatannol was shown to be cytoprotective due the maintenance of cell viability between 1 and 10 μM even in the presence of H2O2. In a concentration of 0.1 μM piceatannol decreased significantly cell viability but increased cellular metabolism and antioxidant capacity of the fibroblasts. On the other hand, the fibroblasts treated with piceatannol at 1 μM presented low metabolism and antioxidant capacity. However, piceatannol did not protect cells from mitochondrial damage as measured by ATP production. In summary, piceatannol is a potent antioxidant in low concentrations with cytoprotective capacity, but it does not prevent all damage caused by hydrogen peroxide.


Biomedicines ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 380 ◽  
Author(s):  
Riaz Ahmad ◽  
Amjad Khan ◽  
Hyeon Jin Lee ◽  
Inayat Ur Rehman ◽  
Ibrahim Khan ◽  
...  

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that represents 60–70% of all dementia cases. AD is characterized by the formation and accumulation of amyloid-beta (Aβ) plaques, neurofibrillary tangles, and neuronal cell loss. Further accumulation of Aβ in the brain induces oxidative stress, neuroinflammation, and synaptic and memory dysfunction. In this study, we investigated the antioxidant and neuroprotective effects of the natural triterpenoid lupeol in the Aβ1–42 mouse model of AD. An Intracerebroventricular injection (i.c.v.) of Aβ (3 µL/5 min/mouse) into the brain of a mouse increased the reactive oxygen species (ROS) levels, neuroinflammation, and memory and cognitive dysfunction. The oral administration of lupeol at a dose of 50 mg/kg for two weeks significantly decreased the oxidative stress, neuroinflammation, and memory impairments. Lupeol decreased the oxidative stress via the activation of nuclear factor erythroid 2-related factor-2 (Nrf-2) and heme oxygenase-1 (HO-1) in the brain of adult mice. Moreover, lupeol treatment prevented neuroinflammation by suppressing activated glial cells and inflammatory mediators. Additionally, lupeol treatment significantly decreased the accumulation of Aβ and beta-secretase-1 (BACE-1) expression and enhanced the memory and cognitive function in the Aβ-mouse model of AD. To the best of our knowledge, this is the first study to investigate the anti-oxidative and neuroprotective effects of lupeol against Aβ1–42-induced neurotoxicity. Our findings suggest that lupeol could serve as a novel, promising, and accessible neuroprotective agent against progressive neurodegenerative diseases such as AD.


2017 ◽  
Vol 34 ◽  
pp. 329-339 ◽  
Author(s):  
Ana C. Moreira ◽  
Ana M. Silva ◽  
Ana F. Branco ◽  
Inês Baldeiras ◽  
Gonçalo C. Pereira ◽  
...  

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1257
Author(s):  
Maria Assunta Potenza ◽  
Luca Sgarra ◽  
Vanessa Desantis ◽  
Carmela Nacci ◽  
Monica Montagnani

A growing number of clinical and epidemiological studies support the hypothesis of a tight correlation between type 2 diabetes mellitus (T2DM) and the development risk of Alzheimer’s disease (AD). Indeed, the proposed definition of Alzheimer’s disease as type 3 diabetes (T3D) underlines the key role played by deranged insulin signaling to accumulation of aggregated amyloid beta (Aβ) peptides in the senile plaques of the brain. Metabolic disturbances such as hyperglycemia, peripheral hyperinsulinemia, dysregulated lipid metabolism, and chronic inflammation associated with T2DM are responsible for an inefficient transport of insulin to the brain, producing a neuronal insulin resistance that triggers an enhanced production and deposition of Aβ and concomitantly contributes to impairment in the micro-tubule-associated protein Tau, leading to neural degeneration and cognitive decline. Furthermore, the reduced antioxidant capacity observed in T2DM patients, together with the impairment of cerebral glucose metabolism and the decreased performance of mitochondrial activity, suggests the existence of a relationship between oxidative damage, mitochondrial impairment, and cognitive dysfunction that could further reinforce the common pathophysiology of T2DM and AD. In this review, we discuss the molecular mechanisms by which insulin-signaling dysregulation in T2DM can contribute to the pathogenesis and progression of AD, deepening the analysis of complex mechanisms involved in reactive oxygen species (ROS) production under oxidative stress and their possible influence in AD and T2DM. In addition, the role of current therapies as tools for prevention or treatment of damage induced by oxidative stress in T2DM and AD will be debated.


2014 ◽  
Vol 28 (S1) ◽  
Author(s):  
Selvaraju Subash ◽  
Musthafa Essa ◽  
Gilles Guillemin ◽  
Samir Al‐Adawi ◽  
Abdullah Al‐Asmi ◽  
...  

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Benjamin Rakela ◽  
Paul Brehm ◽  
Gail Mandel

Studies linking mutations in Methyl CpG Binding Protein 2 (MeCP2) to physiological defects in the neurological disease, Rett syndrome, have focused largely upon neuronal dysfunction despite MeCP2 ubiquitous expression. Here we explore roles for astrocytes in neuronal network function using cortical slice recordings. We find that astrocyte stimulation in wild-type mice increases excitatory synaptic activity that is absent in male mice lacking MeCP2 globally. To determine the cellular basis of the defect, we exploit a female mouse model for Rett syndrome that expresses wild-type MeCP2-GFP in a mosaic distribution throughout the brain, allowing us to test all combinations of wild-type and mutant cells. We find that the defect is dependent upon MeCP2 expression status in the astrocytes and not in the neurons. Our findings highlight a new role for astrocytes in regulation of excitatory synaptic signaling and in the neurological defects associated with Rett syndrome.


1998 ◽  
Vol 254 (2) ◽  
pp. 109-112 ◽  
Author(s):  
Yasuhisa Fujibayashi ◽  
Shoko Yamamoto ◽  
Atsuo Waki ◽  
Junji Konishi ◽  
Yoshiharu Yonekura

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3942
Author(s):  
Ji Hyun Kim ◽  
Hui Wen Meng ◽  
Mei Tong He ◽  
Ji Myung Choi ◽  
Dongjun Lee ◽  
...  

In the present study, we investigated the cognitive improvement effects and its mechanisms of krill oil (KO) in Aβ25–35-induced Alzheimer’s disease (AD) mouse model. The Aβ25–35-injected AD mouse showed memory and cognitive impairment in the behavior tests. However, the administration of KO improved novel object recognition ability and passive avoidance ability compared with Aβ25–35-injected control mice in behavior tests. In addition, KO-administered mice showed shorter latency to find the hidden platform in a Morris water maze test, indicating that KO improved learning and memory abilities. To evaluate the cognitive improvement mechanisms of KO, we measured the oxidative stress-related biomarkers and apoptosis-related protein expressions in the brain. The administration of KO inhibited oxidative stress-related biomarkers such as reactive oxygen species, malondialdehyde, and nitric oxide compared with AD control mice induced by Aβ25–35. In addition, KO-administered mice showed down-regulation of Bax/Bcl-2 ratio in the brain. Therefore, this study indicated that KO-administered mice improved cognitive function against Aβ25–35 by attenuations of neuronal oxidative stress and neuronal apoptosis. It suggests that KO might be a potential agent for prevention and treatment of AD.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lauren N. Miterko ◽  
Tao Lin ◽  
Joy Zhou ◽  
Meike E. van der Heijden ◽  
Jaclyn Beckinghausen ◽  
...  

AbstractDeep brain stimulation (DBS) relieves motor dysfunction in Parkinson’s disease, and other movement disorders. Here, we demonstrate the potential benefits of DBS in a model of ataxia by targeting the cerebellum, a major motor center in the brain. We use the Car8 mouse model of hereditary ataxia to test the potential of using cerebellar nuclei DBS plus physical activity to restore movement. While low-frequency cerebellar DBS alone improves Car8 mobility and muscle function, adding skilled exercise to the treatment regimen additionally rescues limb coordination and stepping. Importantly, the gains persist in the absence of further stimulation. Because DBS promotes the most dramatic improvements in mice with early-stage ataxia, we postulated that cerebellar circuit function affects stimulation efficacy. Indeed, genetically eliminating Purkinje cell neurotransmission blocked the ability of DBS to reduce ataxia. These findings may be valuable in devising future DBS strategies.


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