scholarly journals Dendrobium alkaloids decrease Aβ by regulating α- and β-secretases in hippocampal neurons of SD rats

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7627 ◽  
Author(s):  
Juan Huang ◽  
Nanqu Huang ◽  
Minghui Zhang ◽  
Jing Nie ◽  
Yunyan Xu ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cell Viability ◽  
Learning And Memory ◽  
Hippocampal Neurons ◽  
Memory Function ◽  
Amyloid Β ◽  
Aging Effects ◽  
Potential Health ◽  
Sd Rats

Background Alzheimer’s disease (AD) is the primary cause of dementia in the elderly. The imbalance between production and clearance of amyloid β (Aβ) is a very early, often initiating factor in AD. Dendrobium nobile Lindl. alkaloids (DNLA) extracted from a Chinese medicinal herb, which have been shown to have anti-aging effects, protected against neuronal impairment in vivo and in vitro. Moreover, we confirmed that DNLA can improve learning and memory function in elderly normal mice, indicating that DNLA has potential health benefits. However, the underlying mechanism is unclear. Therefore, we further explored the effect of DNLA on neurons, which is closely related to learning and memory, based on Aβ. Methods We exposed cultured hippocampal neurons to DNLA to investigate the effect of DNLA on Aβ in vitro. Cell viability was evaluated by MTT assays. Proteins were analyzed by Western blot analysis. Results The cell viability of hippocampal neurons was not changed significantly after treatment with DNLA. But DNLA reduced the protein expression of amyloid precursor protein (APP), disintegrin and metalloprotease 10 (ADAM10), β-site APP cleaving enzyme 1 (BACE1) and Aβ1–42 of hippocampal neurons in rats and increased the protein expression of ADAM17. Conclusions DNLA decreases Aβ by regulating α- and β-secretase in hippocampal neurons of SD rats.

Astrocytic Expression of the Immunoreceptor CD300f Protects Hippocampal Neurons from Amyloid-β Oligomer Toxicity In Vitro

2017 ◽  
Vol 14 (7) ◽  
Author(s):  
Thiago Zaqueu Lima ◽  
Luis Roberto Sardinha ◽  
Joan Sayos ◽  
Luiz Eugenio Mello ◽  
Hugo Peluffo
Keyword(s):  
Hippocampal Neurons ◽  
Amyloid Β ◽  
Toxicity In Vitro

scholarly journals Low-Level Light in Combination with Metabolic Modulators for Effective Therapy of Injured Brain

2015 ◽  
Vol 35 (9) ◽  
pp. 1435-1444 ◽  
Author(s):  
Tingting Dong ◽  
Qi Zhang ◽  
Michael R Hamblin ◽  
Mei X Wu
Keyword(s):  
Learning And Memory ◽  
Memory Function ◽  
Light Illumination ◽  
Low Level ◽  
Metabolic Substrates ◽  
Secondary Damage ◽  
Injured Brain ◽  
Combinational Treatment

Vascular damage occurs frequently at the injured brain causing hypoxia and is associated with poor outcomes in the clinics. We found high levels of glycolysis, reduced adenosine triphosphate generation, and increased formation of reactive oxygen species and apoptosis in neurons under hypoxia. Strikingly, these adverse events were reversed significantly by noninvasive exposure of injured brain to low-level light (LLL). Low-level light illumination sustained the mitochondrial membrane potential, constrained cytochrome c leakage in hypoxic cells, and protected them from apoptosis, underscoring a unique property of LLL. The effect of LLL was further bolstered by combination with metabolic substrates such as pyruvate or lactate both in vivo and in vitro. The combinational treatment retained memory and learning activities of injured mice to a normal level, whereas other treatment displayed partial or severe deficiency in these cognitive functions. In accordance with well-protected learning and memory function, the hippocampal region primarily responsible for learning and memory was completely protected by combination treatment, in marked contrast to the severe loss of hippocampal tissue because of secondary damage in control mice. These data clearly suggest that energy metabolic modulators can additively or synergistically enhance the therapeutic effect of LLL in energy-producing insufficient tissue–like injured brain.

MiR-30a-5p Downregulation Induces Neuronal Autophagy by Activating AMPK After 2856MHz Microwave Radiation

2021 ◽  
Author(s):  
Yanhui Hao ◽  
Wenchao Li ◽  
Hui Wang ◽  
Jing Zhang ◽  
Haoyu Wang ◽  
...  
Keyword(s):  
Microwave Radiation ◽  
Hippocampal Neurons ◽  
Target Genes ◽  
Neuronal Damage ◽  
Luciferase Reporter ◽  
Potential Health ◽  
Downstream Target ◽  
Neuronal Autophagy

Abstract Background With the development of science and technology, microwaves are being widely used. More and more attention has been paid to the potential health hazards of microwave exposure. The regulation of miR-30a-5p (miR-30a) on autophagy is involved in the pathophysiological process of many diseases. Our previous study found that 30 mW/cm2 microwave radiation could reduce miR-30a expression and activate neuronal autophagy in rat hippocampus. However, the roles played by miR-30a in microwave-induced neuronal autophagy and related mechanisms remain largely unexplored. Results In the present study, we established neuronal damage models by exposing rat hippocampal neurons and rat adrenal pheochromocytoma (PC12) cell-derived neuron-like cells to 30 mW/cm2 microwave, which resulted in miR-30a downregulation and autophagy activation in vivo and in vitro. Bioinformatics analysis was conducted, and Beclin1, Prkaa2, Irs1, Pik3r2, Rras2, Ddit4, Gabarapl2 and autophagy-related gene 12 (Atg12) were identified as potential downstream target genes of miR-30a involved in regulating autophagy. Based on our previous findings that microwave radiation can cause a neuronal energy metabolism disorder, Prkaa2, encoding adenosine 5’-monophosphate-activated protein kinase α2 (AMPKα2, an important catalytic subunit of energy sensor AMPK), was selected for further analysis. Dual-luciferase reporter assay results showed that Prkaa2 is a downstream target gene of miR-30a. Microwave radiation increased the expression and phosphorylation (Thr172) of AMPKα both in vivo and in vitro. Moreover, the transduction of cells with miR-30a mimics suppressed AMPKα2 expression, inhibited AMPKα (Thr172) phosphorylation and reduced autophagy flux in neuron-like cells. Importantly, miR-30a mimics abolished microwave-activated autophagy and inhibited microwave-induced AMPKα (Thr172) phosphorylation. Conclusions AMPKα2 was a newly founded downstream gene of miR-30a involved in autophagy regulation, and miR-30a downregulation after microwave radiation could promote neuronal autophagy by increasing AMPKα2 expression and activating AMPK signaling.

scholarly journals The Role of Astragaloside IV against Cerebral Ischemia/Reperfusion Injury: Suppression of Apoptosis via Promotion of P62-LC3-Autophagy

Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1838 ◽  
Author(s):  
Yi Zhang ◽  
Ying Zhang ◽  
Xiao-fei Jin ◽  
Xiao-hong Zhou ◽  
Xian-hui Dong ◽  
...  
Keyword(s):  
Cell Viability ◽  
Ischemia Reperfusion Injury ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Sprague Dawley ◽  
Astragaloside Iv ◽  
Ht22 Cells ◽  
Sd Rats ◽  
Neurological Score

Background: Ischemia/reperfusion (I/R) caused by ischemic stroke treatments leads to brain injury, and autophagy plays a role in the pathology. Astragaloside IV is a potential neuroprotectant, but its underlying mechanism on cerebral I/R injury needs to be explored. The objective of this study is to investigate the neuroprotective mechanism of Astragaloside IV against cerebral I/R injury. Methods: Middle cerebral artery occlusion method (MCAO) and oxygen and glucose deprivation/reoxygenation (OGD/R) method were used to simulate cerebral I/R injury in Sprague-Dawley (SD) rats and HT22 cells, respectively. The neurological score, 2,3,5-Triphe-nyltetrazolium chloride (TTC) staining, and transmission electron microscope were used to detect cerebral damage in SD rats. Cell viability and cytotoxicity assay were tested in vitro. Fluorescent staining and flow cytometry were applied to detect the level of apoptosis. Western blotting was conducted to examine the expression of proteins associated with autophagy. Results: This study found that Astragaloside IV could decrease the neurological score, reduce the infarct volume in the brain, and alleviate cerebral I/R injury in MCAO rats. Astragaloside IV promoted cell viability and balanced Bcl-2 and Bax expression in vitro, reduced the rate of apoptosis, decreased the expression of P62, and increased the expression of LC3II/LC3I in HT22 cells after OGD/R. Conclusions: These data suggested that Astragaloside IV plays a neuroprotective role by down-regulating apoptosis by promoting the degree of autophagy.

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 Ameliorative effects of olibanum essential oil on learning and memory in Aβ1-42-induced Alzheimer’s disease mouse model

2020 ◽  
Vol 19 (8) ◽  
pp. 1643-1651
Author(s):  
Zhenzhen Zhang ◽  
Wenhua Chen ◽  
Jie Luan ◽  
Dagui Chen ◽  
Lina Liu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Essential Oil ◽  
Learning And Memory ◽  
Hippocampal Neurons ◽  
Amyloid Β ◽  
Amyloid Plaques ◽  
Morris Water Maze Test ◽  
Amyloid Β Peptide ◽  
Brain Tissues

Purpose: To study the effect of olibanum essential oil (OEO) on learning and memory in Alzheimer’s disease (AD) mouse.Methods: Mice were administered the 42-amino acid form of amyloid β-peptide (Aβ1-42) to induce AD and then treated with OEO at 150, 300, and 600 mg/kg, p.o. for two weeks. Following treatment, the AD mice were assessed by step-down test (SDT), dark avoidance test (DAT), and Morris water maze test (MWM). Blood and brain tissues were collected for biochemical assessments. Gas chromatographymass spectroscopy was used to analyze the main constituents of OEO.Results: The main constituents of OEO were limonene, α-pinene, and 4-terpineol. Treatment with OEO prolonged t latency in SDT and DAT, but decreased error times. Escape latency decreased and crossing times were rose in the MWM following OEO treatment (p < 0.5). Treatment with OEO also enhanced the acetylcholine levels and decreased the acetylcholinesterase levels in serum and brain tissue (p < 0.5). Additionally, OEO reduced amyloid plaques in the hippocampus and protected hippocampal neurons from damage. Furthermore, OEO decreased c-fos expression in  hippocampus tissues from AD mice (p < 0.5).Conclusion: OEO has significant ameliorative effect AD-induced deterioration in learning and memory in AD mouse induced by Aβ1-42. The mechanisms of these effects are related to increased acetylcholine contents, reduction of amyloid plaques, protection of hippocampal neurons, and downregulation of c-fos in brain tissues. The results justify the need for further investigation of candidate drugs derived from OEO for the  management of AD. Keywords: Olibanum, Essential oil, Learning, Memory, AD

scholarly journals In vitro anti-cholinesterase activity and in vivo screening of Coccoloba uvifera, Mimusops elengi and Syzygium aqueum extracts on learning and memory function of chronic cerebral hypoperfusion rat

2021 ◽  
Vol 4 (2) ◽  
pp. 1-13
Author(s):  
Kesevan Rajah Kumaran ◽  
Habibah Abdul Wahab ◽  
Zurina Hassan
Keyword(s):  
Learning And Memory ◽  
Plant Extracts ◽  
Cholinesterase Activity ◽  
Memory Function ◽  
Chronic Cerebral Hypoperfusion ◽  
Cerebral Hypoperfusion ◽  
Ageing Population ◽  
Mimusops Elengi

Vascular dementia (VaD), is one of the most common types of dementia in the ageing population, initiated by chronic cerebral hypoperfusion (CCH). At present, effective therapeutic approaches to cure VaD are still missing. Cholinergic system dysfunction in the central nervous system (CNS) has been recognised as one of the main reasons for learning and memory impairment in VaD patients. Therefore, medications that restore the level of acetylcholine (ACh) neurotransmitter by inhibiting cholinesterase activity were proposed as a potential candidate to treat VaD patients. Permanent occlusion of bilateral common carotid arteries (POBCCA) surgery method was performed to develop CCH model in rats. The present study evaluated the anti-cholinesterase activity of three Malaysian plant methanol leaf extracts in vitro and further validated its cognitive-enhancing effects in vivo using POBCCA rats. The selected plant extracts were Coccoloba uvifera (stems), Mimusops elengi (leaves) and Syzygium aqueum (leaves). The in vitro anti-cholinesterase activities of these plants were determined using Ellman's method. The effects of selected plant extracts (100 and 200 mg/kg, p.o.) on learning and memory functions were evaluated using a series of behavioural tests. All the selected plant extracts exhibited good anti-acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in vitro, with IC50 ranging from 3.67 to 16.04 and 5.6 to 13.95 µg/mL, respectively. Extracts of S. aqueum (200 mg/kg) improve both short- and long-term recognition memories, whereas M. elengi and S. aqueum (200 mg/kg) extracts improve spatial learning. None of the extracts impaired motor and exploratory functions in POBCCA rats. In conclusion, methanol extracts of C. uvifera, M. elengi and S. aqueum showed good anti-cholinesterase activity in vitro. However, only M. elengi and S. aqueum improve learning and memory function in POBCCA rats.

scholarly journals 1,800 MHz Radiofrequency Electromagnetic Irradiation Impairs Neurite Outgrowth With a Decrease in Rap1-GTP in Primary Mouse Hippocampal Neurons and Neuro2a Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Yanqi Li ◽  
Ping Deng ◽  
Chunhai Chen ◽  
Qinlong Ma ◽  
Huifeng Pi ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cell Viability ◽  
Brain Development ◽  
Neurite Outgrowth ◽  
Hippocampal Neurons ◽  
Neurite Length ◽  
Primary Mouse ◽  
Primary Hippocampal Neurons ◽  
Neuro2a Cells

Background: With the global popularity of communication devices such as mobile phones, there are increasing concerns regarding the effect of radiofrequency electromagnetic radiation (RF-EMR) on the brain, one of the most important organs sensitive to RF-EMR exposure at 1,800 MHz. However, the effects of RF-EMR exposure on neuronal cells are unclear. Neurite outgrowth plays a critical role in brain development, therefore, determining the effects of 1,800 MHz RF-EMR exposure on neurite outgrowth is important for exploring its effects on brain development.Objectives: We aimed to investigate the effects of 1,800 MHz RF-EMR exposure for 48 h on neurite outgrowth in neuronal cells and to explore the associated role of the Rap1 signaling pathway.Material and Methods: Primary hippocampal neurons from C57BL/6 mice and Neuro2a cells were exposed to 1,800 MHz RF-EMR at a specific absorption rate (SAR) value of 4 W/kg for 48 h. CCK-8 assays were used to determine the cell viability after 24, 48, and 72 h of irradiation. Neurite outgrowth of primary hippocampal neurons (DIV 2) and Neuro2a cells was observed with a 20 × optical microscope and recognized by ImageJ software. Rap1a and Rap1b gene expressions were detected by real-time quantitative PCR. Rap1, Rap1a, Rap1b, Rap1GAP, and p-MEK1/2 protein expressions were detected by western blot. Rap1-GTP expression was detected by immunoprecipitation. The role of Rap1-GTP was assessed by transfecting a constitutively active mutant plasmid (Rap1-Gly_Val-GFP) into Neuro2a cells.Results: Exposure to 1,800 MHz RF-EMR for 24, 48, and 72 h at 4 W/kg did not influence cell viability. The neurite length, primary and secondary neurite numbers, and branch points of primary mouse hippocampal neurons were significantly impaired by 48-h RF-EMR exposure. The neurite-bearing cell percentage and neurite length of Neuro2a cells were also inhibited by 48-h RF-EMR exposure. Rap1 activity was inhibited by 48-h RF-EMR with no detectable alteration in either gene or protein expression of Rap1. The protein expression of Rap1GAP increased after 48-h RF-EMR exposure, while the expression of p-MEK1/2 protein decreased. Overexpression of constitutively active Rap1 reversed the decrease in Rap1-GTP and the neurite outgrowth impairment in Neuro2a cells induced by 1,800 MHz RF-EMR exposure for 48 h.Conclusion: Rap1 activity and related signaling pathways are involved in the disturbance of neurite outgrowth induced by 48-h 1,800 MHz RF-EMR exposure. The effects of RF-EMR exposure on neuronal development in infants and children deserve greater focus.

scholarly journals CD82 Aggravates Sevoflurane - Induced Neurotoxicity by Regulating TRPM7 in Developing Neurons

2020 ◽  
Keyword(s):  
Protein Expression ◽  
Cell Viability ◽  
Cell Apoptosis ◽  
Hippocampal Neurons ◽  
Transient Receptor Potential ◽  
Time Dependent ◽  
Dependent Manner ◽  
Over Expression ◽  
Transient Receptor Potential Melastatin ◽  
Developing Neurons

Background: Sevoflurane, a commonly used anesthetic in neonatal, could induce neurotoxicity in newborn animals. CD82 was found to be involved in age-related cognitive impairment. However, the role of CD82 in sevoflurane-induced neurotoxicity remains elusive. Methods: Hippocampal neurons were isolated from neonatal rats (postnatal day 1 or 2), and then exposed to 1.8 % sevoflurane for 6, 12, 24 or 48 hours. Neurons were pre-transfected with siRNA targeting CD82 (siCD82) or co-transfected with siTRPM7 (transient receptor potential melastatin 7) and pcDNA 3.1-CD82, and then exposed with sevoflurane (1.8%, 12 hours). Cell viability of the neurons was analyzed with MTT assay, and cell apoptosis was determined by flow cytometry. Protein expression was analyzed by western blot. Results: Sevoflurane exposure decreased cell viability of the developing hippocampal neurons in a time-dependent manner. Protein expressions of CD82 and TRPM7 were increased in neurons post sevoflurane exposure in a time-dependent manner. Pre-transfection of siCD82 attenuated sevoflurane-induced decrease in cell viability and increase in cell apoptosis in the neurons. Moreover, knockdown of CD82 reversed the promoting effects of sevoflurane on protein expression of cleaved TRPM7 and cleaved caspase-3. Over-expression of CD82 aggravated sevoflurane-induced decrease in cell viability and increase in cell apoptosis in neurons, while knockdown of TRPM7 counteracted with the effects of CD82 over-expression on sevoflurane-induced developing neurons. Conclusion: Sevoflurane exposure increased the expression of CD82 and TRPM7 in developing hippocampal neurons, decreased cell viability and promoted the cell apoptosis. Knockdown of CD82 partially ameliorated sevoflurane-induced neurotoxicity by down-regulation of cleaved TRPM7 in the developing neurons.

scholarly journals LncRNA AC008972.1 as a Novel Therapeutic Target for Prostate Cancer

2021 ◽  
Author(s):  
Jia Liu ◽  
Qijin Wu ◽  
Ruiyu Song ◽  
Wen Miao ◽  
Yuting Ma ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Protein Expression ◽  
Cell Viability ◽  
Therapeutic Target ◽  
Xenograft Model ◽  
Migration And Invasion ◽  
Down Regulation ◽  
Mouse Xenograft Model ◽  
Novel Therapeutic

Abstract Background: Prostate cancer is the leading cause of disease and death in men. Long non-coding RNAs (lncRNAs), microRNA (miRNAs) and mRNAs networks mediate prostate cancer progression. Here, we aim to investigate functions of lncRNA AC008972.1/miR-143-3p/thousand-and-one-amino acid 2 kinase (TAOK2) in prostate cancer. Methods: The expression levels of lncRNA AC008972.1, miR-143-3p and TAOK2 are detected in prostate cancer tissues and cell lines by RT-qPCR. PC3 and LNCaP cells are used to establish lncRNA AC008972.1-knockdown, miR-143-3p-overexpressing, and TAOK2-down-regulated cells. Cell viability is examined by MTT and cell proliferation is detected by clone formation assay. Cell migration and invasion are tested by wound scratch assay and transwell chamber assay. The rate of apoptosis was analyzed by flow cytometry. The protein expression is detected by western blot assay. The target is validated by RNA binding protein immunoprecipitation (RIP) assay and dual luciferase activity assay. A mouse xenograft model was conducted to investigate the oncogenic effect of lncRNA AC008972.1 on prostate cancer. Results: High expression of lncRNA AC008972.1 was associated with low overall survival in prostate cancer. Down-regulation of lncRNA AC008972.1 delayed prostate cancer process by inhibiting cell viability, proliferation, migration and invasion, as well as altering protein expression，whereas cell apoptosis was markedly promoted. LncRNA AC008972.1 negatively regulated miR-143-3p expression and miR-143-3p overexpression promoted prostate cancer process in vitro. TAOK2 expression was decreased by miR-143-3p through the complementary targeting of TAOK2 mRNA. Down-regulation of lncRNA AC008972.1 mitigated prostate cancer process in vitro based on miR-143-3p/TAOK2 node. Furthmore, the data of xenograft model experiment showed that inhibition of lncRNA AC008972.1 suppressed tumor growth in vivo. Conclusions: Collectively, knockdown of lncRNA AC008972.1 inhibits prostate cancer cell growth based on down-regulation of TAOK2 induced by miR-143-3p. Here, we identify that lncRNA AC008972.1 exerts essential roles in the progression of prostate cancer and serves as a novel therapeutic target for prostate cancer.

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