scholarly journals Deciphering the Potential Neuroprotective Effects of Luteolin against Aβ1–42-Induced Alzheimer’s Disease

2021 ◽  
Vol 22 (17) ◽  
pp. 9583
Author(s):  
Sareer Ahmad ◽  
Myeung Hoon Jo ◽  
Muhammad Ikram ◽  
Amjad Khan ◽  
Myeong Ok Kim
Keyword(s):  
Amyloid Beta ◽  
Apoptotic Cell ◽  
Protective Effects ◽  
Neuroprotective Effects ◽  
Tnf Α ◽  
Synaptic Markers ◽  
Mitogen Activated Protein ◽  
Mice Brain ◽  
Ad Mouse Model ◽  
Necrosis Factor

The current study was undertaken to unveil the protective effects of Luteolin, a natural flavonoid, against amyloid-beta (Aβ1–42)-induced neuroinflammation, amyloidogenesis, and synaptic dysfunction in mice. For the development of an AD mouse model, amyloid-beta (Aβ1–42, 5 µL/5 min/mouse) oligomers were injected intracerebroventricularly (i.c.v.) into mice’s brain by using a stereotaxic frame. After that, the mice were treated with Luteolin for two weeks at a dose of 80 mg/kg/day. To monitor the biochemical changes, we conducted western blotting and immunofluorescence analysis. According to our findings, the infusion of amyloid-beta activated c-Jun N-terminal kinases (p-JNK), p38 mitogen-activated protein kinases, glial fibrillary acidic protein (GFAP), and ionized calcium adaptor molecule 1 (Iba-1) in the cortex and hippocampus of the experimental mice; these changes were significantly inhibited in Aβ1–42 + Luteolin-treated mice. Likewise, we also checked the expression of inflammatory markers, such as p-nuclear factor-kB p65 (p-NF-kB p65 (Ser536), tissue necrosis factor (TNF-α), and Interleukin1-β (IL-1β), in Aβ1–42-injected mice brain, which was attenuated in Aβ1–42 + Luteolin-treated mice brains. Further, we investigated the expression of pro- and anti-apoptotic cell death markers such as Bax, Bcl-2, Caspase-3, and Cox-2, which was significantly reduced in Aβ1–42 + Lut-treated mice brains compared to the brains of the Aβ-injected group. The results also indicated that with the administration of Aβ1–42, the expression levels of β-site amyloid precursor protein cleaving enzyme (BACE-1) and amyloid-beta (Aβ1–42) were significantly enhanced, while they were reduced in Aβ1–42 + Luteolin-treated mice. We also checked the expression of synaptic markers such as PSD-95 and SNAP-25, which was significantly enhanced in Aβ1–42 + Lut-treated mice. To unveil the underlying factors responsible for the protective effects of Luteolin against AD, we used a specific JNK inhibitor, which suggested that Luteolin reduced Aβ-associated neuroinflammation and neurodegeneration via inhibition of JNK. Collectively, our results indicate that Luteolin could serve as a novel therapeutic agent against AD-like pathological changes in mice.

scholarly journals Kaempferol Attenuates LPS-Induced Striatum Injury in Mice Involving Anti-Neuroinflammation, Maintaining BBB Integrity, and Down-Regulating the HMGB1/TLR4 Pathway

2019 ◽  
Vol 20 (3) ◽  
pp. 491 ◽  
Author(s):  
Ying-Lin Yang ◽  
Xiao Cheng ◽  
Wei-Han Li ◽  
Man Liu ◽  
Yue-Hua Wang ◽  
...  
Keyword(s):  
Protective Effects ◽  
Neuroprotective Effects ◽  
Chemotactic Protein ◽  
Tnf Α ◽  
Factor Α ◽  
Cell Adhesion Molecule 1 ◽  
Neuron Injury ◽  
Intercellular Cell Adhesion Molecule ◽  
Necrosis Factor ◽  
Pro Inflammatory Cytokines

Neuroinflammation has been demonstrated to be linked with Parkinson’s disease (PD), Alzheimer’s disease, and cerebral ischemia. Our previous investigation had identified that kaempferol (KAE) exerted protective effects on cortex neuron injured by LPS. In this study, the effects and possible mechanism of KAE on striatal dopaminergic neurons induced by LPS in mice were further investigated. The results showed that KAE improved striatal neuron injury, and increased the levels of tyrosine hydroxylase (TH) and postsynaptic density protein 95 (PSD95) in the striatum of mice. In addition, KAE inhibited the production of pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), reduced the level of monocyte chemotactic protein-1 (MCP-1), intercellular cell adhesion molecule-1 (ICAM-1), and cyclooxygenase-2 (COX-2) in the striatum tissues. Furthermore, KAE protected blood-brain barrier (BBB) integrity and suppressed the activation of the HMGB1/TLR4 inflammatory pathway induced by LPS in striatum tissues of mice. In conclusion, these results suggest that KAE may have neuroprotective effects against striatum injury that is induced by LPS and the possible mechanisms are involved in anti-neuroinflammation, maintaining BBB integrity, and down-regulating the HMGB1/TLR4 pathway.

scholarly journals Icariin Prevents Amyloid Beta-Induced Apoptosis via the PI3K/Akt Pathway in PC-12 Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dongdong Zhang ◽  
Zhe Wang ◽  
Chenxia Sheng ◽  
Weijun Peng ◽  
Shan Hui ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Pc12 Cells ◽  
Amyloid Beta ◽  
Chinese Herb ◽  
Protective Effects ◽  
Amyloid Beta Protein ◽  
Neuroprotective Effects ◽  
Pi3k Inhibitor Ly294002 ◽  
Induced Apoptosis

Icariin is a prenylated flavonol glycoside derived from the Chinese herbEpimedium sagittatumthat exerts a variety of pharmacological activities and shows promise in the treatment and prevention of Alzheimer’s disease. In this study, we investigated the neuroprotective effects of icariin against amyloid beta protein fragment 25–35 (Aβ25–35) induced neurotoxicity in cultured rat pheochromocytoma PC12 cells and explored potential underlying mechanisms. Our results showed that icariin dose-dependently increased cell viability and decreasedAβ25–35-induced apoptosis, as assessed by MTT assay and Annexin V/propidium iodide staining, respectively. Results of western blot analysis revealed that the selective phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 suppressed icariin-induced Akt phosphorylation, suggesting that the protective effects of icariin are associated with activation of the PI3K/Akt signaling pathway. LY294002 also blocked the icariin-induced downregulation of proapoptotic factors Bax and caspase-3 and upregulation of antiapoptotic factor Bcl-2 inAβ25–35-treated PC12 cells. These findings provide further evidence for the clinical efficacy of icariin in the treatment of Alzheimer’s disease.

scholarly journals MON-721 Crude Protein of Pyropia Yezoensis Protects Against Tumor Necrosis Factor-á-Induced Myotube Atrophy by Regulating the Mitogen-Activated Protein Kinase and Nuclear Factor-Kappab Signaling Pathways in C2C12 Myotubes

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Min-Kyeong Lee ◽  
Nam Taek-Jeong ◽  
Youn Hee Choi
Keyword(s):  
Muscle Atrophy ◽  
Crude Protein ◽  
Tumor Necrosis ◽  
Mitogen Activated Protein Kinase ◽  
C2c12 Myotubes ◽  
Nuclear Factor Kappab ◽  
Nuclear Factor ◽  
Tnf Α ◽  
Mitogen Activated Protein ◽  
Necrosis Factor

Abstract Proinflammatory cytokines induce ubiquitin-proteasome-dependent proteolysis by activating intracellular factors in skeletal muscle, leading to muscle atrophy. Therefore, we investigated the protective effect of Pyropia yezoensis crude protein (PYCP) on tumor necrosis factor (TNF)-α-induced muscle atrophy in vitro. Mouse skeletal muscle C2C12 myotubes were treated for 48 h with TNF-α (20 ng/mL) in the presence or absence of PYCP (25, 50, and 100 μg/mL). PYCP at concentrations up to 100 μg/mL did not affect cell viability. Exposure to TNF-α for 48 h significantly decreased the diameter of myotubes, which was increased by treatment with 25, 50, and 100 μg/mL PYCP. PYCP inhibited TNF-α-induced intracellular reactive oxygen species accumulation in C2C12 myotubes. In addition, PYCP significantly reduced the levels of phosphorylated p38 and JNK. Moreover, by inhibiting the degradation of inhibitor of kappaB-α, PYCP significantly suppressed the TNF-α-induced increased transcriptional activity and nuclear translocation of nuclear factor-kappaB (NF-κB). Furthermore, PYCP inhibited E3-ubiquitin ligases in TNF-α-treated C2C12 myotubes. In conclusion, PYCP ameliorated TNF-α-induced muscle atrophy by inhibiting the mitogen-activated protein kinase-mediated NF-κB pathway, indicating that it has therapeutic potential for related disorders.

scholarly journals MMP-2 Plays an Important Role During the Early Acute Developmental Phase of Oligofructose-Induced Equine Laminitis

2015 ◽  
Vol 59 (1) ◽  
pp. 149-153 ◽  
Author(s):  
Xinran Li ◽  
Renli Jiang ◽  
Guanying Wang ◽  
Yue Li ◽  
Xiaojing Fan ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Plasma Concentrations ◽  
Clinical Signs ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Matrix Metalloproteinase 2 ◽  
Developmental Phase ◽  
Tnf Α ◽  
Mitogen Activated Protein ◽  
Factor Α ◽  
Necrosis Factor

Abstract The study was conducted on 24 Mongolian horses, with oligofructose-induced equine laminitis (10 g/kg b.w.). The objective of the study was to investigate the relationships among matrix metalloproteinase 2 (MMP-2), P38 mitogen-activated protein kinases (P38 MAPK), tissue inhibitor of metalloproteinase 2 (TIMP-2), lipopolysaccharides (LPS), and tumour necrosis factor-α (TNF-α) during acute developmental phase of laminitis, and to determine whether there are any characteristic tendencies. Moreover, plasma concentrations of LPS and TNF-α were measured in order to determine the time of leukocytes’ activation. Eleven of the 12 horses showed clinical signs of laminitis. The contents of MMP-2 and P38 MAPK increased significantly from 8 h to 64 h, and the content of TIMP-2 decreased significantly at the same time. Plasma LPS concentrations increased significantly between 8 h and 20 h and reached a peak of 0.024 ± 0.009 EU/mL (equivalent to 3.04 ± 1.19 pg/mL) at 12 h. TNF-α concentration increased between 20 h and 36 h. This data indicates that MMP-2 plays an important role during the early acute developmental phase of oligofructose-induced equine laminitis.

scholarly journals Nfa34810 Facilitates Nocardia farcinica Invasion of Host Cells and Stimulates Tumor Necrosis Factor Alpha Secretion through Activation of the NF-κB and Mitogen-Activated Protein Kinase Pathways via Toll-Like Receptor 4

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Xingzhao Ji ◽  
Xiujuan Zhang ◽  
Heqiao Li ◽  
Lina Sun ◽  
Xuexin Hou ◽  
...  
Keyword(s):  
Tumor Necrosis ◽  
Host Cells ◽  
Mitogen Activated Protein Kinase ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Mitogen Activated Protein ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT The mechanism underlying the pathogenesis of Nocardia is not fully known. The Nfa34810 protein of Nocardia farcinica has been predicted to be a virulence factor. However, relatively little is known regarding the interaction of Nfa34810 with host cells, specifically invasion and innate immune activation. In this study, we aimed to determine the role of recombinant Nfa34810 during infection. We demonstrated that Nfa34810 is an immunodominant protein located in the cell wall. Nfa34810 protein was able to facilitate the uptake and internalization of latex beads coated with Nfa34810 protein into HeLa cells. Furthermore, the deletion of the nfa34810 gene in N. farcinica attenuated the ability of the bacteria to infect both HeLa and A549 cells. Moreover, stimulation with Nfa34810 triggered macrophages to produce tumor necrosis factor alpha (TNF-α), and it also activated mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) signaling pathways by inducing the phosphorylation of ERK1/2, p38, JNK, p65, and AKT in macrophages. Specific inhibitors of ERK1/2, JNK, and NF-κB significantly reduced the expression of TNF-α, which demonstrated that Nfa34810-mediated TNF-α production was dependent upon the activation of these kinases. We further found that neutralizing antibodies against Toll-like receptor 4 (TLR4) significantly inhibited TNF-α secretion. Taken together, our results indicated that Nfa34810 is a virulence factor of N. farcinica and plays an important role during infection. Nfa34810-induced production of TNF-α in macrophages also involves ERK, JNK, and NF-κB via the TLR4 pathway.

scholarly journals PKCϵ is involved in JNK activation that mediates LPS-induced TNF-α, which induces apoptosis in macrophages

2003 ◽  
Vol 285 (5) ◽  
pp. C1235-C1245 ◽  
Author(s):  
Mònica Comalada ◽  
Jordi Xaus ◽  
Annabel F. Valledor ◽  
Carlos López-López ◽  
Daniel J. Pennington ◽  
...  
Keyword(s):  
Cell Model ◽  
Primary Cultures ◽  
Signaling Mechanism ◽  
Major Function ◽  
Tnf Α ◽  
Mitogen Activated Protein ◽  
Induced Apoptosis ◽  
Factor Α ◽  
Jnk Activation ◽  
Necrosis Factor

Lipopolysaccharide (LPS) is a powerful stimulator of macrophages and induces apoptosis in these cells. Using primary cultures of bone marrow-derived macrophages, we found that the autocrine production of tumor necrosis factor-α (TNF-α) has a major function in LPS-induced apoptosis. LPS activates PKC and regulates the different mitogen-activated protein kinases (MAPK). We aimed to determine its involvement either in the secretion of TNF-α or in the induction of apoptosis. Using specific inhibitors and mice with the gene for PKCϵ disrupted, we found that LPS-induced TNF-α-dependent apoptosis is mostly mediated by PKCϵ, which is not directly involved in the signaling mechanism of apoptosis but rather in the process of TNF-α secretion. In our cell model, all three MAPKs were involved in the regulation of TNF-α secretion, but at different levels. JNK mainly regulates TNF-α transcription and apoptosis, whereas ERK and p38 contribute to the regulation of TNF-α production, probably through posttranscriptional mechanisms. Only JNK activity is mediated by PKCϵ in response to LPS and so plays a major role in TNF-α secretion and LPS-induced apoptosis. We demonstrated in macrophages that LPS involving PKCϵ regulates JNK activity and produces TNF-α, which induces apoptosis.

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