INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2023
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IF 8.2
Shuang Xiao,Peng Zhang,Guowen Zhang,Wenwen Li,Haowen Lin,Xing Hu
The activation of toll-like receptor 4 (TLR4) signaling is crucial for initiating and coordinating the immune response against infections, and is proved as a vital target for inflammatory diseases. Herein, TLR4 with sufficient amount and functional activity was generated by heterologous expression and used to investigate the mechanism of apigenin (Api)/chrysin (Chr) inhibition of TLR4 activation. The results demonstrated that Api/Chr exhibited a strong fluorescence quenching effect through a static quenching and a high binding affinity ( K a > 10 5 L·mol −1 ) with TLR4, indicating the potential of Api/Chr as a TLR4 inhibitor. Additionally, the binding of Api/Chr induced a loose and unstable conformation of TLR4 with evidence like the decreased hydrophobicity of the tryptophan microenvironment, decreased α-helix content and increased free sulfhydryl content, resulting in reduced stability of the TLR4. The computer simulations revealed that Api/Chr occupied the myeloid differentiation factor 2 (MD-2) binding region, preventing MD-2 from binding to TLR4. Furthermore, the accuracy of the binding site between Api/Chr and TLR4 was confirmed through genetic mutations . Overall, the mechanism by which Api/Chr inhibited TLR4 activation was elucidated at the macroscopic and molecular levels, providing the worthful information concerning the future therapeutic application of Api/Chr as a natural TLR4 inhibitor.
研究领域:
免疫学
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药理学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
Journal of Toxicologic Pathology
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2022
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IF 1.25
Wen-Ling Mou,Shi-Ru Chen,Zhen-Ting Wu,Li-Hua Hu,Ji-Ye Zhang,Hong-Jie Chang,Hang Zhou,Ying Liu
Liver fibrosis results from liver inflammation and progresses to liver cirrhosis or liver cancer. It is known that nonalcoholic liver disease is mediated by the Toll-like receptor 4 (TLR4)/myeloid differentiation factor-2 (MD-2)–tumor necrosis factor-alpha (TNF-α) signaling pathway. This study aimed to investigate whether alcoholic liver disease is also mediated by this pathway. To this end, we first established rat models of liver fibrosis by administering alcohol. Next, the rats were injected with anti-TLR4 and anti-MD-2 antibodies. Real Time Quantitative PCR (RT-qPCR) and Western blotting were used to detect the activation of the TLR4/MD-2–TNF-α signaling pathway and hepatic stellate cells (HSCs). Moreover, the expression of molecules related to liver fibrosis was estimated. The morphology of rat liver tissue was observed through hematoxylin–eosin staining and Masson staining. For in vitro studies, Kupffer cells (KCs) isolated from the liver were transfected with si-TLR4 and si-MD-2 and co-cultured with HSCs to determine the activity of HSCs. It was found that alcohol treatment activated the TLR4/MD-2–TNF-α signaling pathway and upregulated the molecules associated with liver fibrosis. However, inhibition of TLR4 and MD-2 partially reversed this trend. Notably, in vitro studies indicated that knockdown of TLR4 and MD-2 in KCs partially inhibited LPS-induced activation of KCs and HSCs. Overall, this study showed that alcohol induces liver fibrosis via the LPS-TLR4/MD-2–TNF-α signaling pathway.
研究领域:
分子生物学
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免疫学
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病理学
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药理学
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DOI
PubMed
高影响因子
MOLECULES
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2021
·Vol. 26
·期 18
·5698
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IF 4.412
Sennan Qiao,Hansi Zhang,Fei Sun,Zhenyan Jiang
Artemisinin (also known as Qinghaosu), an active component of the Qinghao extract, is widely used as antimalarial drug. Previous studies reveal that artemisinin and its derivatives also have effective anti-inflammatory and immunomodulatory properties, but the direct molecular target remains unknown. Recently, several reports mentioned that myeloid differentiation factor 2 (MD-2, also known as lymphocyte antigen 96) may be the endogenous target of artemisinin in the inhibition of lipopolysaccharide signaling. However, the exact interaction between artemisinin and MD-2 is still not fully understood. Here, experimental and computational methods were employed to elucidate the relationship between the artemisinin and its inhibition mechanism. Experimental results showed that artemether exhibit higher anti-inflammatory activity performance than artemisinin and artesunate. Molecular docking results showed that artemisinin, artesunate, and artemether had similar binding poses, and all complexes remained stable throughout the whole molecular dynamics simulations, whereas the binding of artemisinin and its derivatives to MD-2 decreased the TLR4(Toll-Like Receptor 4)/MD-2 stability. Moreover, artemether exhibited lower binding energy as compared to artemisinin and artesunate, which is in good agreement with the experimental results. Leu61, Leu78, and Ile117 are indeed key residues that contribute to the binding free energy. Binding free energy analysis further confirmed that hydrophobic interactions were critical to maintain the binding mode of artemisinin and its derivatives with MD-2.Keywords:molecular dynamics simulation;myeloid differentiation factor 2;artemisinin;anti-inflammatory;binding free energy
研究领域:
药理学
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免疫学
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分子生物学
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计算化学
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产品关联
DOI
PubMed
高影响因子
iScience
·
2024
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IF 4.6
Chenming Zou,Ruihua Cai,Yunbing Li,Yu Xue,Guoguang Zhang,Gulimiran Alitongbieke,Yutian Pan,Sanguo Zhang
Recently, increasing evidence has shown the association between liver abnormal inflammation and cognition impairment, yet their age-related pathogenesis remains obscure. Here, our study provides a potential mechanistic link between liver macrophage excessive activation and neuroinflammation in aging progression. In aged and LPS-injected C57BL/6J mice, systemic administration of β-chitosan ameliorates hepatic macrophage-driven inflammation and reduces peripheral accumulations of TNF-α and IL-1β. Downregulation of circulatory pro-inflammatory cytokines then decreases vascular VCAM1 expression and neuroinflammation in the hippocampus, leading to cognitive improvement in aged/LPS-stimulated mice. Interestingly, β-chitosan treatment also exhibits the beneficial effects on the behavioral recovery of aged/LPS-stimulated zebrafish and Caenorhabditis elegans . In our cell culture and molecular docking experiments, we found that β-chitosan prefers shielding the MD-2 pocket, thus blocking the activation of TLR4-MD-2 complex to suppress NF-κB signaling pathway activation. Together, our findings highlight the extensive therapeutic potential of β-chitosan in reversing aged-related/LPS-induced cognitive impairment via the liver-brain axis.
研究领域:
免疫学
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神经科学
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老年学
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药理学
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产品关联
DOI
PubMed
高影响因子
Food Science and Human Wellness
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2023
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IF 7
Hui Zou,Tingting Ben,Ping Wu,Geoffrey I.N. Waterhouse,Yilun Chen
This novel study identifies the effective anti-inflammatory phenolic compounds in dandelion and provides mechanistic insights into their interactions with receptor proteins (toll‐like receptor 4, TLR4; co‐receptor myeloid differentiation protein-2, MD-2) using UHPLC-ESI-MS/MS, lipopolysaccharide (LPS)-stimulated THP-1 cell line, fluorescence quenching and anisotropy, molecular docking (single ligand and multi-ligand docking) and molecular dynamics simulation. A 50 % aqueous methanol extract had a greater anti-inflammatory effect and higher chicoric acid content, compared with the 100 % water and 100 % methanol extracts. Chicoric acid, chlorogenic acid, methylophiopogonone A, caffeic acid, gallic acid monohydrate and 4'- O -demethylbroussonin A had relatively high binding energies and contents in all extracts. Chicoric acid competed with chlorogenic acid, 4'- O -demethylbroussonin A and quercetin for MD-2. Among dandelion’s phenolics, chicoric acid most effectively hindered TLR4-MD-2 complex formation, with a quenching constant of 0.62 × 10 6 L/mol for MD-2 or TLR4 at 320 K, and binding energies of –6.87 and –5.97 kcal/mol, respectively, for MD-2 and TLR4.
研究领域:
药理学
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生物化学
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分子生物学
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分析化学
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免疫学
✓ 已验证
DOI
高影响因子
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