Amyloid-β Inhibits PDGFβ Receptor Activation and Prevents PDGF-BBInduced Neuroprotection

2018 ◽  
Vol 15 (7) ◽  
pp. 618-627 ◽  
Author(s):  
Hui Liu ◽  
Golam T. Saffi ◽  
Maryam S. Vasefi ◽  
Youngjik Choi ◽  
Jeff S. Kruk ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Hippocampal Neurons ◽  
Neuronal Damage ◽  
Neuroblastoma Cell ◽  
Amyloid Β ◽  
Receptor Activation ◽  
Cell Number ◽  
Physical Interaction ◽  
Protective Effects

Background: PDGFβ receptors and their ligand, PDGF-BB, are upregulated in vivo after neuronal insults such as ischemia. When applied exogenously, PDGF-BB is neuroprotective against excitotoxicity and HIV proteins. Objective: Given this growth factor's neuroprotective ability, we sought to determine if PDGF-BB would be neuroprotective against amyloid-β (1-42), one of the pathological agents associated with Alzheimer's disease (AD). Methods and Results: In both primary hippocampal neurons and the human-derived neuroblastoma cell line, SH-SY5Y, amyloid-β treatment for 24 h decreased surviving cell number in a concentrationdependent manner. Pretreatment with PDGF-BB failed to provide any neuroprotection against amyloid-β in primary neurons and only very limited protective effects in SH-SY5Y cells. In addition to its neuroprotective action, PDGF promotes cell growth and division in several systems, and the application of PDGFBB alone to serum-starved SH-SY5Y cells resulted in an increase in cell number. Amyloid-β attenuated the mitogenic effects of PDGF-BB, inhibited PDGF-BB-induced PDGFβ receptor phosphorylation, and attenuated the ability of PDGF-BB to protect neurons against NMDA-induced excitotoxicity. Despite the ability of amyloid-β to inhibit PDGFβ receptor activation, immunoprecipitation experiments failed to detect a physical interaction between amyloid-β and PDGF-BB or the PDGFβ receptor. However, G protein-coupled receptor transactivation of the PDGFβ receptor (an exclusively intracellular signaling pathway) remained unaffected by the presence of amyloid-β. Conclusions: As the PDGF system is upregulated upon neuronal damage, the ability of amyloid-β to inhibit this endogenous neuroprotective system should be further investigated in the context of AD pathophysiology.

scholarly journals Coagulation Factor XII protects neurons from apoptosis by triggering a crosstalk between HGFR/c-Met and EGFR/ErbB1 signaling pathways

2020 ◽  
Author(s):  
Eugénie Garnier ◽  
Damien Levard ◽  
Carine Ali ◽  
Yannick Hommet ◽  
Tiziana Crepaldi ◽  
...  
Keyword(s):  
Growth Factor ◽  
Egf Receptor ◽  
Neuronal Cell ◽  
Coagulation Factor ◽  
Receptor Activation ◽  
Target Cells ◽  
Cultured Neurons ◽  
Factor Xii ◽  
Protective Effects

Abstract Background Factor XII (FXII) is a serine protease that participates in the intrinsic coagulation pathway. Several studies have shown that plasmatic FXII exert a deleterious role in cerebral ischemia and traumatic brain injury by promoting thrombo-inflammation. Nevertheless, the direct impact of FXII on neuronal cell fate remains unknown.Methods We investigated whether FXII influenced neuronal death induced in vivo by stereotaxic injection of N-methyl-D-Aspartate (NMDA) and in vitro by serum deprivation of cultured neurons.Results We found that FXII reduced brain lesions induced in vivo and protected cultured neurons from apoptosis through a growth factor-like effect. This mechanism was triggered by direct interaction with epidermal growth factor (EGF) receptor, activation of this receptor and engagement of anti-apoptotic intracellular pathways. Interestingly, the “proteolytically” active and two-chain form of FXII, αFXIIa, exerted additional protective effects by converting the pro-form of hepatocyte growth factor (HGF) into its mature form, which in turn activated HGF receptor (HGFR/c-Met) pathway. Lastly, the use of non-proteolytic FXII (αFXIIa-PPACK) unveiled an alternative EGFR and HGFR co-activation pathway, through co-receptor transphosphorylation. Conclusion This study describes novel mechanisms of action of FXII and discloses neurons as target cells for the protective effects of single and double-chain forms of FXII.

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 Slitrk2 controls excitatory synapse development via PDZ-mediated protein interactions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kyung Ah Han ◽  
Jinhu Kim ◽  
Hyeonho Kim ◽  
Dongwook Kim ◽  
Dongseok Lim ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Intracellular Signaling ◽  
Hippocampal Neurons ◽  
Pdz Domain ◽  
Protein Tyrosine Phosphatases ◽  
Excitatory Synapse ◽  
Receptor Protein ◽  
Binding Motif ◽  
Synapse Development

AbstractMembers of the Slitrk (Slit- and Trk-like protein) family of synaptic cell-adhesion molecules control excitatory and inhibitory synapse development through isoform-dependent extracellular interactions with leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs). However, how Slitrks participate in activation of intracellular signaling pathways in postsynaptic neurons remains largely unknown. Here we report that, among the six members of the Slitrk family, only Slitrk2 directly interacts with the PDZ domain-containing excitatory scaffolds, PSD-95 and Shank3. The interaction of Slitrk2 with PDZ proteins is mediated by the cytoplasmic COOH-terminal PDZ domain-binding motif (Ile-Ser-Glu-Leu), which is not found in other Slitrks. Mapping analyses further revealed that a single PDZ domain of Shank3 is responsible for binding to Slitrk2. Slitrk2 forms in vivo complexes with membrane-associated guanylate kinase (MAGUK) family proteins in addition to PSD-95 and Shank3. Intriguingly, in addition to its role in synaptic targeting in cultured hippocampal neurons, the PDZ domain-binding motif of Slitrk2 is required for Slitrk2 promotion of excitatory synapse formation, transmission, and spine development in the CA1 hippocampal region. Collectively, our data suggest a new molecular mechanism for conferring isoform-specific regulatory actions of the Slitrk family in orchestrating intracellular signal transduction pathways in postsynaptic neurons.

Effect of bFGF on neuronal damage induced by sequential treatment of amyloid β and excitatory amino acid in vitro and in vivo

2012 ◽  
Vol 695 (1-3) ◽  
pp. 76-82 ◽  
Author(s):  
Takafumi Noshita ◽  
Norihito Murayama ◽  
Tetsushi Oka ◽  
Ryoko Ogino ◽  
Shizuo Nakamura ◽  
...  
Keyword(s):  
Amino Acid ◽  
Excitatory Amino Acid ◽  
Neuronal Damage ◽  
Amyloid Β ◽  
Sequential Treatment

scholarly journals Protective Effects of Scolopendra Water Extract on Trimethyltin-Induced Hippocampal Neurodegeneration and Seizures in Mice

2019 ◽  
Vol 9 (12) ◽  
pp. 369
Author(s):  
Yun-Soo Seo ◽  
Mary Jasmin Ang ◽  
Byeong Cheol Moon ◽  
Hyo Seon Kim ◽  
Goya Choi ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Primary Cultures ◽  
Water Extract ◽  
Model Systems ◽  
Inflammatory Factor ◽  
Dependent Manner ◽  
Protective Effects ◽  
Cell Degeneration

Trimethyltin (TMT) is an organotin compound with potent neurotoxic action characterized by neuronal degeneration in the hippocampus. This study evaluated the protective effects of a Scolopendra water extract (SWE) against TMT intoxication in hippocampal neurons, using both in vitro and in vivo model systems. Specifically, we examined the actions of SWE on TMT- (5 mM) induced cytotoxicity in primary cultures of mouse hippocampal neurons (7 days in vitro) and the effects of SWE on hippocampal degeneration in adult TMT- (2.6 mg/kg, intraperitoneal) treated C57BL/6 mice. We found that SWE pretreatment (0–100 μg/mL) significantly reduced TMT-induced cytotoxicity in cultured hippocampal neurons in a dose-dependent manner, as determined by lactate dehydrogenase and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assays. Additionally, this study showed that perioral administration of SWE (5 mg/kg), from −6 to 0 days before TMT injection, significantly attenuated hippocampal cell degeneration and seizures in adult mice. Furthermore, quantitative analysis of Iba-1 (Allograft inflammatory factor 1)- and GFAP (Glial fibrillary acidic protein)-immunostained cells revealed a significant reduction in the levels of Iba-1- and GFAP-positive cell bodies in the dentate gyrus (DG) of mice treated with SWE prior to TMT injection. These data indicated that SWE pretreatment significantly protected the hippocampus against the massive activation of microglia and astrocytes elicited by TMT. In addition, our data showed that the SWE-induced reduction of immune cell activation was linked to a significant reduction in cell death and a significant improvement in TMT-induced seizure behavior. Thus, we conclude that SWE ameliorated the detrimental effects of TMT toxicity on hippocampal neurons, both in vivo and in vitro. Altogether, our findings hint at a promising pharmacotherapeutic use of SWE in hippocampal degeneration and dysfunction.

scholarly journals DHEA Attenuates Microglial Activation via Induction of JMJD3 in Experimental Subarachnoid Haemorrhage

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Tao Tao ◽  
Guang-Jie Liu ◽  
Xuan Shi ◽  
Yan Zhou ◽  
Yue Lu ◽  
...  
Keyword(s):  
Subarachnoid Haemorrhage ◽  
Microglial Activation ◽  
Neuronal Damage ◽  
Neuroprotective Effect ◽  
Early Brain Injury ◽  
Protective Effects ◽  
In Vivo Models ◽  
The Brain

Abstract Background Microglia are resident immune cells in the central nervous system and central to the innate immune system. Excessive activation of microglia after subarachnoid haemorrhage (SAH) contributes greatly to early brain injury, which is responsible for poor outcomes. Dehydroepiandrosterone (DHEA), a steroid hormone enriched in the brain, has recently been found to regulate microglial activation. The purpose of this study was to address the role of DHEA in SAH. Methods We used in vivo models of endovascular perforation and in vitro models of haemoglobin exposure to illustrate the effects of DHEA on microglia in SAH. Results In experimental SAH mice, exogenous DHEA administration increased DHEA levels in the brain and modulated microglial activation. Ameliorated neuronal damage and improved neurological outcomes were also observed in the SAH mice pretreated with DHEA, suggesting neuronal protective effects of DHEA. In cultured microglia, DHEA elevated the mRNA and protein levels of Jumonji d3 (JMJD3, histone 3 demethylase) after haemoglobin exposure, downregulated the H3K27me3 level, and inhibited the transcription of proinflammatory genes. The devastating proinflammatory microglia-mediated effects on primary neurons were also attenuated by DHEA; however, specific inhibition of JMJD3 abolished the protective effects of DHEA. We next verified that DHEA-induced JMJD3 expression, at least in part, through the tropomyosin-related kinase A (TrkA)/Akt signalling pathway. Conclusions DHEA has a neuroprotective effect after SAH. Moreover, DHEA increases microglial JMJD3 expression to regulate proinflammatory/anti-inflammatory microglial activation after haemoglobin exposure, thereby suppressing inflammation.

scholarly journals Pathogenic substantiation of application of erythropoietin modified forms and peptide analogues as cytotprotectors

2020 ◽  
Vol 2 (1) ◽  
pp. 70-81
Author(s):  
Igor Ivanov ◽  
Aleksandr Nikiforov ◽  
Nikolai Vengerovich ◽  
Vladimir V. Perelygin ◽  
Ylia Proshina
Keyword(s):  
Side Effects ◽  
Protective Effect ◽  
Intracellular Signaling ◽  
Active Regions ◽  
Erythropoietin Receptor ◽  
Short Chain ◽  
Protective Effects ◽  
Modified Forms ◽  
Peptide Analogues

Provides a review of the evidence from experimental and clinical studies on the blood-forming and non-blood-forming tissue protective effects of erythropoietin. Information on its side effects (stimulation of tumor growth, autoimmune reactions, arterial hypertension, etc.), limiting the clinical use as a cytoprotector, is summarized. Well-known modifications of the erythropoietin molecule with a tissue protective effect are considered, in particular, desialylated (asialoEPO), carboxylated (CEPO) and glutaraldehyde (GEPO) cytokine analogues. The results of biomedical studies describing the tissue protective effects of these compounds, as well as possible mechanisms of their receptor action, are presented. The article discusses the main short-chain erythropoietin mimetics that reproduce individual active regions of cytokine amino acid sequence and contain from 11 to 25 amino acids: Helix B, ARA290, Eportis, Epopeptide-ab, MK-X, Epobis, NL100. The biochemical mechanisms of cytoprotective action of erythropoietin and its derivatives are considered, including binding to the heterodimeric receptor of non-blood-forming tissues and activation of intracellular signaling molecules possessing properties of apopotosis inhibitors. It was noted that the tissue protective effect of erythropoietin in vivo is observed in hemostimulating doses and is accompanied by side effects. At the same time, the use of modified forms of erythropoietin and its short-chain peptide analogues, which have a high affinity for the isoform of the erythropoietin receptor of non-blood-forming tissues and do not have hematopoietic properties, allows avoiding the development of side effects and reducing effective doses by 10-20 times.

scholarly journals Neuropharmacological Effects of Quercetin: A Literature-Based Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Md. Shahazul Islam ◽  
Cristina Quispe ◽  
Rajib Hossain ◽  
Muhammad Torequl Islam ◽  
Ahmed Al-Harrasi ◽  
...  
Keyword(s):  
Neurodegenerative Diseases ◽  
Neuroprotective Effect ◽  
Animal Experiments ◽  
Amyloid Β ◽  
Neuronal Injury ◽  
Amyloid Β Peptide ◽  
Protective Effects ◽  
Neuroprotective Effects

Quercetin (QUR) is a natural bioactive flavonoid that has been lately very studied for its beneficial properties in many pathologies. Its neuroprotective effects have been demonstrated in many in vitro studies, as well as in vivo animal experiments and human trials. QUR protects the organism against neurotoxic chemicals and also can prevent the evolution and development of neuronal injury and neurodegeneration. The present work aimed to summarize the literature about the neuroprotective effect of QUR using known database sources. Besides, this review focuses on the assessment of the potential utilization of QUR as a complementary or alternative medicine for preventing and treating neurodegenerative diseases. An up-to-date search was conducted in PubMed, Science Direct and Google Scholar for published work dealing with the neuroprotective effects of QUR against neurotoxic chemicals or in neuronal injury, and in the treatment of neurodegenerative diseases. Findings suggest that QUR possess neuropharmacological protective effects in neurodegenerative brain disorders such as Alzheimer’s disease, Amyloid β peptide, Parkinson’s disease, Huntington's disease, multiple sclerosis, and amyotrophic lateral sclerosis. In summary, this review emphasizes the neuroprotective effects of QUR and its advantages in being used in complementary medicine for the prevention and treatment o of different neurodegenerative diseases.

Targeting CCR1 for the Treatment of Osteolytic Bone Disease in Multiple Myeloma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2503-2503
Author(s):  
Sonia Vallet ◽  
Noopur Raje ◽  
MariaTeresa Fulciniti ◽  
Kenji Ishitsuka ◽  
Teru Hideshima ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Proliferation ◽  
Clinical Trials ◽  
Bone Disease ◽  
Cell Number ◽  
In Vivo Studies ◽  
Protective Effects ◽  
Osteolytic Bone Disease

Abstract Osteolytic bone disease (OBD) is a frequent complication of multiple myeloma (MM), affecting 70 to 80% of the patients. OBD is characterized by imbalanced bone remodeling, due to decreased osteoblast (OB) number and increased osteoclast (OC) formation and activity. MM cells secrete osteoclastogenic factors, such as receptor activator of nuclear factor kappa B ligand (RANKL) and CCL3. In turn, OC support MM cell proliferation and survival, thus promoting a positive feedback that exacerbates bone resorption. Chemokines modulate osteoclastogenesis and promote MM cell proliferation, in particular CCL3 and its receptor CCR1 play an important role in mediating OBD in MM. MLN3897 (Millennium Pharmaceuticals, Cambridge) is a novel small molecule specific antagonist of human CCR1 (IC50 0.8 nM). It has a favorable toxicity profile in healthy volunteers and is currently undergoing phase II clinical trials in rheumatoid arthritis and multiple sclerosis. Here we evaluate the effects of MLN3897 on OC function and activity, as well as OC-MM cell interactions. Our in vitro data demonstrates a dual mechanism of action for MLN3897: it inhibits osteoclastogenesis and also overcomes the protective effects conferred by OC on MM cells. Our data further shows inhibition of OC formation and function by 40 and 70%, respectively, following MLN3897 treatment. This is mediated via inhibition of the fusion process and is accompanied by downregulation of pERK and c-fos signaling. To analyze its effect on MM cells, we verified CCR1 and CCR5 expression levels on MM1.S (15% and 3.6%) and OPM1 (3.8 and 0.7%). Our data show that OC secrete high levels of CCL3 which triggers MM cell migration; and that MLN3897 abrogates these effects by inhibiting the PI3K/Akt pathway. Moreover, MLN3897 overcomes the proliferative advantage conferred by OC on MM cells, as demonstrated in INA6, MM1.S and MM patient derived primary cells. OC induced MM cell proliferation is mediated by adhesion and cytokine secretion, and MLN3897 abrogates both MM cell-to-OC adhesion and interleukin-6 (IL6) secretion by OC in a co-culture system, thereby resulting in decreased MM cell survival and proliferation. To confirm these in vitro results, in vivo studies in a SCID-hu mouse model are underway. Implanted SCID-Hu INA-6 bearing mice are treated with twice daily oral MLN3897 for 3 weeks. The evaluation of osteolytic lesions and OC, OB and endothelial cell number; and tumor burden will be presented. Our in vitro results therefore show novel biologic sequelae of CCL3 and its inhibition on both osteoclastogenesis and MM cell growth. Our in vivo experiments will further validate the role of CCR1 in a human BM microenvironment-MM model, providing the framework for clinical trials of MLN3897 for the treatment of OBD in MM.

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