scholarly journals Glycine, the smallest amino acid, confers neuroprotection against d-galactose-induced neurodegeneration and memory impairment by regulating c-Jun N-terminal kinase in the mouse brain

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Rahat Ullah ◽  
Myeung Hoon Jo ◽  
Muhammad Riaz ◽  
Sayed Ibrar Alam ◽  
Kamran Saeed ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Amino Acid ◽  
Protein Expression ◽  
Mouse Brain ◽  
Memory Impairment ◽  
Specific Inhibitor ◽  
Synaptic Dysfunction ◽  
Ht22 Cells

Abstract Background Glycine is the smallest nonessential amino acid and has previously unrecognized neurotherapeutic effects. In this study, we examined the mechanism underlying the neuroprotective effect of glycine (Gly) against neuroapoptosis, neuroinflammation, synaptic dysfunction, and memory impairment resulting from d-galactose-induced elevation of reactive oxygen species (ROS) during the onset of neurodegeneration in the brains of C57BL/6N mice. Methods After in vivo administration of d-galactose (d-gal; 100 mg/kg/day; intraperitoneally (i/p); for 60 days) alone or in combination with glycine (1 g/kg/day in saline solution; subcutaneously; for 60 days), all of the mice were sacrificed for further biochemical (ROS/lipid peroxidation (LPO) assay, Western blotting, and immunohistochemistry) after behavioral analyses. An in vitro study, in which mouse hippocampal neuronal HT22 cells were treated with or without a JNK-specific inhibitor (SP600125), and molecular docking analysis were used to confirm the underlying molecular mechanism and explore the related signaling pathway prior to molecular and histological analyses. Results Our findings indicated that glycine (an amino acid) inhibited d-gal-induced oxidative stress and significantly upregulated the expression and immunoreactivity of antioxidant proteins (Nrf2 and HO-1) that had been suppressed in the mouse brain. Both the in vitro and in vivo results indicated that d-gal induced oxidative stress-mediated neurodegeneration primarily by upregulating phospho-c-Jun N-terminal kinase (p-JNK) levels. However, d-gal + Gly cotreatment reversed the neurotoxic effects of d-gal by downregulating p-JNK levels, which had been elevated by d-gal. We also found that Gly reversed d-gal-induced neuroapoptosis by significantly reducing the protein expression levels of proapoptotic markers (Bax, cytochrome c, cleaved caspase-3, and cleaved PARP-1) and increasing the protein expression level of the antiapoptotic protein Bcl-2. Both the molecular docking approach and the in vitro study (in which the neuronal HT22 cells were treated with or without a p-JNK-specific inhibitor (SP600125)) further verified our in vivo findings that Gly bound to the p-JNK protein and inhibited its function and the JNK-mediated apoptotic pathway in the mouse brain and HT22 cells. Moreover, the addition of Gly alleviated d-gal-mediated neuroinflammation by inhibiting gliosis via attenuation of astrocytosis (GFAP) and microgliosis (Iba-1) in addition to reducing the protein expression levels of various inflammatory cytokines (IL-1βeta and TNFα). Finally, the addition of Gly reversed d-gal-induced synaptic dysfunction by upregulating the expression of memory-related presynaptic protein markers (synaptophysin (SYP), syntaxin (Syn), and a postsynaptic density protein (PSD95)) and markedly improved behavioral measures of cognitive deficits in d-gal-treated mice. Conclusion Our findings demonstrate that Gly-mediated deactivation of the JNK signaling pathway underlies the neuroprotective effect of Gly, which reverses d-gal-induced oxidative stress, apoptotic neurodegeneration, neuroinflammation, synaptic dysfunction, and memory impairment. Therefore, we suggest that Gly (an amino acid) is a safe and promising neurotherapeutic candidate that might be used for age-related neurodegenerative diseases.

scholarly journals STAT3 inhibitor mitigates cerebral amyloid angiopathy and parenchymal amyloid plaques while improving cognitive functions and brain networks

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jogender Mehla ◽  
Itender Singh ◽  
Deepti Diwan ◽  
James W. Nelson ◽  
Molly Lawrence ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Human Brain ◽  
Cognitive Functions ◽  
Specific Inhibitor ◽  
Amyloid Angiopathy ◽  
In Vitro Experiments ◽  
Aβ Peptides ◽  
Cerebral Amyloid

AbstractPrevious reports indicate a potential role for signal transducer and activator of transcription 3 (STAT3) in amyloid-β (Aβ) processing and neuritic plaque pathogenesis. In the present study, the impact of STAT3 inhibition on cognition, cerebrovascular function, amyloid pathology, oxidative stress, and neuroinflammation was studied using in vitro and in vivo models of Alzheimer’s disease (AD)-related pathology. For in vitro experiments, human brain vascular smooth muscle cells (HBVSMC) and human brain microvascular endothelial cells (HBMEC) were used, and these cultured cells were exposed to Aβ peptides followed by measurement of activated forms of STAT3 expression and reactive oxygen species (ROS) generation. Further, 6 months old 5XFAD/APOE4 (5XE4) mice and age-matched negative littermates were used for in vivo experiments. These mice were treated with STAT3 specific inhibitor, LLL-12 for 2 months followed by neurobehavioral and histopathological assessment. In vitro experiments showed exposure of cerebrovascular cells to Aβ peptides upregulated activated forms of STAT3 and produced STAT3-mediated vascular oxidative stress. 5XE4 mice treated with the STAT3-specific inhibitor (LLL-12) improved cognitive functions and functional connectivity and augmented cerebral blood flow. These functional improvements were associated with a reduction in neuritic plaques, cerebral amyloid angiopathy (CAA), oxidative stress, and neuroinflammation. Reduction in amyloid precursor protein (APP) processing and attenuation of oxidative modification of lipoprotein receptor related protein-1 (LRP-1) were identified as potential underlying mechanisms. These results demonstrate the broad impact of STAT3 on cognitive functions, parenchymal and vascular amyloid pathology and highlight the therapeutic potential of STAT3 specific inhibition for treatment of AD and CAA.

scholarly journals Inhibition of Oxidative Neurotoxicity and Scopolamine-Induced Memory Impairment by γ-Mangostin: In Vitro and In Vivo Evidence

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Youngmun Lee ◽  
Sunyoung Kim ◽  
Yeonsoo Oh ◽  
Young-Mi Kim ◽  
Young-Won Chin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Memory Impairment ◽  
Neuronal Damage ◽  
Biological Activities ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ros Generation ◽  
Garcinia Mangostana

Among a series of xanthones identified from mangosteen, the fruit of Garcinia mangostana L. (Guttifereae), α- and γ-mangostins are known to be major constituents exhibiting diverse biological activities. However, the effects of γ-mangostin on oxidative neurotoxicity and impaired memory are yet to be elucidated. In the present study, the protective effect of γ-mangostin on oxidative stress-induced neuronal cell death and its underlying action mechanism(s) were investigated and compared to that of α-mangostin using primary cultured rat cortical cells. In addition, the effect of orally administered γ-mangostin on scopolamine-induced memory impairment was evaluated in mice. We found that γ-mangostin exhibited prominent protection against H2O2- or xanthine/xanthine oxidase-induced oxidative neuronal death and inhibited reactive oxygen species (ROS) generation triggered by these oxidative insults. In contrast, α-mangostin had no effects on the oxidative neuronal damage or associated ROS production. We also found that γ-mangostin, not α-mangostin, significantly inhibited H2O2-induced DNA fragmentation and activation of caspases 3 and 9, demonstrating its antiapoptotic action. In addition, only γ-mangostin was found to effectively inhibit lipid peroxidation and DPPH radical formation, while both mangostins inhibited β-secretase activity. Furthermore, we observed that the oral administration of γ-mangostin at dosages of 10 and 30 mg/kg markedly improved scopolamine-induced memory impairment in mice. Collectively, these results provide both in vitro and in vivo evidences for the neuroprotective and memory enhancing effects of γ-mangostin. Multiple mechanisms underlying this neuroprotective action were suggested in this study. Based on our findings, γ-mangostin could serve as a potentially preferable candidate over α-mangostin in combatting oxidative stress-associated neurodegenerative diseases including Alzheimer’s disease.

scholarly journals Ionising Radiation Immediately Impairs Synaptic Plasticity-Associated Cytoskeletal Signalling Pathways in HT22 Cells and in Mouse Brain: An In Vitro/In Vivo Comparison Study

PLoS ONE ◽  
2014 ◽  
Vol 9 (10) ◽  
pp. e110464 ◽  
Author(s):  
Stefan J. Kempf ◽  
Sonja Buratovic ◽  
Christine von Toerne ◽  
Simone Moertl ◽  
Bo Stenerlöw ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Mouse Brain ◽  
Ionising Radiation ◽  
Signalling Pathways ◽  
Comparison Study ◽  
Ht22 Cells

scholarly journals Cytochrome c oxidase III as a mechanism for apoptosis in heart failure following myocardial infarction

2009 ◽  
Vol 297 (4) ◽  
pp. C928-C934 ◽  
Author(s):  
Changgong Wu ◽  
Lin Yan ◽  
Christophe Depre ◽  
Sunil K. Dhar ◽  
You-Tang Shen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Infarction ◽  
Heart Failure ◽  
Cytochrome C ◽  
Protein Expression ◽  
Cell Viability ◽  
Cytochrome C Oxidase ◽  
Mitochondrial Gene

Cytochrome c oxidase (COX) is composed of 13 subunits, of which COX I, II, and III are encoded by a mitochondrial gene. COX I and II function as the main catalytic components, but the function of COX III is unclear. Because myocardial ischemia affects mitochondrial oxidative metabolism, we hypothesized that COX activity and expression would be affected during postischemic cardiomyopathy. This hypothesis was tested in a monkey model following myocardial infarction (MI) and subsequent pacing-induced heart failure (HF). In this model, COX I protein expression was decreased threefold after MI and fourfold after HF ( P < 0.05 vs. sham), whereas COX II expression remained unchanged. COX III protein expression increased 5-fold after MI and further increased 10-fold after HF compared with sham ( P < 0.05 vs. sham). The physiological impact of COX III regulation was examined in vitro. Overexpression of COX III in mitochondria of HL-1 cells resulted in an 80% decrease in COX I, 60% decrease in global COX activity, 60% decrease in cell viability, and threefold increase in apoptosis ( P < 0.05). Oxidative stress induced by H2O2 significantly ( P < 0.05) increased COX III expression. H2O2 decreased cell viability by 47 ± 3% upon overexpression of COX III, but only by 12 ± 5% in control conditions ( P < 0.05). We conclude that ischemic stress in vivo and oxidative stress in vitro lead to upregulation of COX III, followed by downregulation of COX I expression, impaired COX oxidative activity, and increased apoptosis. Therefore, upregulation of COX III may contribute to the increased susceptibility to apoptosis following MI and subsequent HF.

scholarly journals Contribution of CFTR to Alveolar Fluid Clearance by Lipoxin A4via PI3K/Akt Pathway in LPS-Induced Acute Lung Injury

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Yi Yang ◽  
Yang Cheng ◽  
Qing-Quan Lian ◽  
Li Yang ◽  
Wei Qi ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Protein Expression ◽  
Specific Inhibitor ◽  
Akt Pathway ◽  
Alveolar Type ◽  
Alveolar Fluid Clearance ◽  
Cftr Protein

The lipoxins are the first proresolution mediators to be recognized and described as the endogenous “braking signals” for inflammation. We evaluated the anti-inflammatory and proresolution bioactions of lipoxin A4in our lipopolysaccharide (LPS-)induced lung injury model. We demonstrated that lipoxin A4significantly improved histology of rat lungs and inhibited IL-6 and TNF-αin LPS-induced lung injury. In addition, lipoxin A4increased alveolar fluid clearance (AFC) and the effect of lipoxin A4on AFC was abolished byCFTRinh-172(a specific inhibitor of CFTR). Moreover, lipoxin A4could increase cystic fibrosis transmembrane conductance regulator (CFTR) protein expressionin vitroandin vivo. In rat primary alveolar type II (ATII) cells, LPS decreased CFTR protein expression via activation of PI3K/Akt, and lipoxin A4suppressed LPS-stimulated phosphorylation of Akt. These results showed that lipoxin A4enhanced CFTR protein expression and increased AFC via PI3K/Akt pathway. Thus, lipoxin A4may provide a potential therapeutic approach for acute lung injury.

scholarly journals In vitro and in vivo tenocyte-protective effectiveness of dehydroepiandrosterone against high glucose-induced oxidative stress

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shintaro Mukohara ◽  
Yutaka Mifune ◽  
Atsuyuki Inui ◽  
Hanako Nishimoto ◽  
Takashi Kurosawa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Matrix Metalloproteinase ◽  
Protein Expression ◽  
Achilles Tendon ◽  
Mrna Expression ◽  
High Glucose ◽  
Control Group ◽  
Type I

Abstract Background Dehydroepiandrosterone (DHEA), an adrenal steroid, has a protective role against diabetes. This study aimed to investigate the in vitro and in vivo protective effects of DHEA against high glucose-induced oxidative stress in tenocytes and tendons. Methods Tenocytes from normal Sprague-Dawley rats were cultured in low-glucose (LG) or high-glucose (HG) medium with or without DHEA. The experimental groups were: control group (LG without DHEA), LG with DHEA, HG without DHEA, and HG with DHEA. Reactive oxygen species (ROS) production, apoptosis, and messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, and interleukin-6 (IL-6) were determined. Further, diabetic rats were divided into a control group and a DHEA-injected group (DHEA group). NOX1 and NOX4 protein expression and mRNA expression of NOX1, NOX4, IL-6, matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-2, and type I and III collagens in the Achilles tendon were determined. Results In rat tenocytes, DHEA decreased the expression of NOX1 and IL-6, ROS accumulation, and apoptotic cells. In the diabetic rat Achilles tendon, NOX1 protein expression and mRNA expression of NOX1, IL-6, MMP-2, TIMP-2, and type III collagen were significantly lower while type I collagen expression was significantly higher in the DHEA group than in the control group. Conclusions DHEA showed antioxidant and anti-inflammatory effects both in vitro and in vivo. Moreover, DHEA improved tendon matrix synthesis and turnover, which are affected by hyperglycemic conditions. DHEA is a potential preventive drug for diabetic tendinopathy.

scholarly journals (Pro)renin receptor involves in myocardial fibrosis and oxidative stress in diabetic cardiomyopathy via the PRR–YAP pathway

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shiran Yu ◽  
Xuefei Dong ◽  
Min Yang ◽  
Qingtao Yu ◽  
Jie Xiong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Myocardial Fibrosis ◽  
Cardiac Fibroblasts ◽  
Animal Experiments ◽  
Specific Inhibitor ◽  
Neonatal Rat ◽  
Rnai Silencing ◽  
The Impact

Abstract(Pro)renin receptor (PRR) and Yes-associated protein (YAP) play an important role in cardiovascular diseases. However, the role of PRR–YAP pathway in the pathogenesis of DCM is also not clear. We hypothesized that PRR–YAP pathway may promote pathological injuries in DCM by triggering redox. Wistar rats and neonatal rat cardiac fibroblasts were respectively used in vivo and in vitro studies. In order to observe the effects of PRR mediated YAP pathway on the pathogenesis of DCM, animal experiments were divided into 3 parts, including the evaluation the effects of PRR overexpression, PRR RNAi silencing and YAP RNAi silencing. Recombinant-adenoviruses-carried-PRR-gene (Ad-PRR), Ad-PRR-shRNA and lentivirus-carried-YAP-shRNA were constructed and the effects of PRR mediated YAP on the pathogenesis of DCM were evaluated. YAP specific inhibitor Verteporfin was also administrated in cardiac fibroblasts to explore the impact of PRR–YAP pathway on oxidative stress and myocardial fibrosis. The results displayed that PRR overexpression could enhance YAP expression but PRR RNAi silencing down-regulated its expression. Moreover, PRR overexpression could exacerbate oxidative stress and myocardial fibrosis in DCM, and these pathological changes could be rescued by YAP blockade. We concluded that PRR–YAP pathway plays a key role in the pathogenesis of DCM.

scholarly journals Role of SIRT1 in Hepatic Encephalopathy: In Vivo and In Vitro Studies Focusing on the NLRP3 Inflammasome

2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Fangzhou Jiao ◽  
Yao Wang ◽  
Qian Chen ◽  
Pan Cao ◽  
Chunxia Shi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hepatic Encephalopathy ◽  
Nlrp3 Inflammasome ◽  
Microglial Activation ◽  
Male Rats ◽  
Therapeutic Effects ◽  
Ht22 Cells ◽  
Brain Oxidative Stress

Hepatic encephalopathy (HE) is a neuropsychiatric disorder resulting from acute or chronic liver failure. This study is aimed at investigating the therapeutic effects and mechanisms of SIRT1 in thioacetamide- (TAA-) induced rat HE models. A selective activator (CAY10602) and inhibitor (EX527) of SIRT1 were used in this study. All male rats were separated into control, TAA, CAY10602+TAA, and EX527+TAA groups. Histological damage, liver function, serum ammonia, behavioral changes, and brain oxidative stress were measured in each group. Western blotting was used to measure SIRT1, NLRP3, ASC, and IL-1β protein expression. The results showed that CAY10602 alleviated liver injury, improved neurological decline, reduced microglial activation and brain oxidative stress, and improved the survival rates of HE rats. Moreover, CAY10602 inhibited activation of the NLRP3 inflammasome in microglia of the brain cortex in HE rats. Next, cell experiments confirmed that CAY10602 inhibited activation of the NLRP3 inflammasome in BV2 microglial cells. However, inhibition of SIRT1 by EX527 or lentivirus could enhance activation of the NLRP3 inflammasome in this process. Finally, CAY10602 reduced the neurotoxicity induced by high levels of ammonia in HT22 cells. Taken together, CAY10602 alleviates TAA-induced HE by suppressing microglial activation and the NLRP3 inflammasome and reducing the neurotoxicity of NH4Cl in HT22 cells. A pharmacologic activator of SIRT1 may be a promising approach for the treatment of HE.

scholarly journals In Vitro and in Vivo Tenocyte-protective Effectiveness of Dehydroepiandrosterone Against High Glucose-induced Oxidative Stress

2021 ◽  
Author(s):  
Shintaro Mukohara ◽  
Yutaka Mifune ◽  
Atsuyuki Inui ◽  
Hanako Nishimoto ◽  
Takashi Kurosawa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Matrix Metalloproteinase ◽  
Protein Expression ◽  
Achilles Tendon ◽  
Mrna Expression ◽  
High Glucose ◽  
Control Group ◽  
Type I

Abstract BackgroundDehydroepiandrosterone (DHEA), an adrenal steroid, has a protective role against diabetes. The aim of this study was to investigate the in vitro and in vivo protective effects of DHEA against high glucose-induced oxidative stress in tenocytes and tendons. Methods In an in vitro study, tenocytes from normal Sprague-Dawley rats were cultured in low-glucose (LG) or high-glucose (HG) medium with or without DHEA. The experimental groups were: control group (LG without DHEA), LG with DHEA, HG without DHEA, and HG with DHEA. Reactive oxygen species (ROS) production, apoptosis, and messenger RNA (mRNA) expression of NADPH oxidase (NOX) 1 and 4, and interleukin-6 (IL-6) were determined. In the in vivo study, diabetic rats were divided into a control group and a DHEA-injected group (DHEA group). NOX1 and NOX4 protein expression and mRNA expression of NOX1, NOX4, IL-6, matrix metalloproteinase (MMP)-2, tissue inhibitors of matrix metalloproteinase (TIMP)-2, and type I and III collagens in the Achilles tendon were determined. Results In rat tenocytes, DHEA decreased the expression of NOX1 and IL-6, ROS accumulation, and apoptotic cells. In the diabetic rat Achilles tendon, NOX1 protein expression and mRNA expression of NOX1, IL-6, MMP-2, TIMP-2, and type III collagen were significantly lower, while type I collagen expression was significantly lower in the DHEA group.Conclusions DHEA showed antioxidant and anti-inflammatory effects both in vitro and in vivo. Moreover, DHEA improved tendon matrix synthesis and turnover which are affected by hyperglycemic conditions. DHEA could be a preventive drug for the diabetic tendinopathy.

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