Immune recognition of excessive neurotoxins by microglia is a trigger for the onset of neuroinflammation in the brain,leading to neurodegeneration in Alzheimer’s disease(AD).Blocking active recognition of microglia w...Immune recognition of excessive neurotoxins by microglia is a trigger for the onset of neuroinflammation in the brain,leading to neurodegeneration in Alzheimer’s disease(AD).Blocking active recognition of microglia while removing neurotoxins holds promise for fundamentally alleviating neurotoxin-induced immune responses,but is very challenging.Herein,an engineered macrophage-biomimetic versatile nanoantidote(OT-Lipo@M)is developed for inflammation-targeted therapy against AD by neurotoxin neutralization and immune recognition suppression.Coating macrophage membranes can not only endow OT-Lipo@M with anti-phagocytic and inflammation-tropism capabilities to target inflammatory lesions in AD brain,but also efficiently reduce neurotoxin levels to prevent them from activating microglia.The loaded oxytocin(OT)can be slowly released to downregulate the expression of immune recognition site Toll-like receptor 4(TLR4)on microglia,inhibiting TLR4-mediated pro-inflammatory signalling cascade.Benefiting from this two-pronged immunosuppressive strategy,OT-Lipo@M exhibits outstanding therapeutic effects on ameliorating cognitive deficits,inhibiting neuronal apoptosis,and enhancing synaptic plasticity in AD mice,accompanied by the delayed hippocampal atrophy and brain microstructural disruption by in vivo 9.4T MR imaging.This work provides new insights into potential AD therapeutics targeting microglia-mediated neuroinflammation at the source.展开更多
Background Trichophyton rubrum （T. rubrum） represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested tha...Background Trichophyton rubrum （T. rubrum） represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested that it may result from the failure of epithelial cells to recognize T. rubrum effectively and initiate effective immune responses. The C-type lectin receptors （CLR） and toll-like receptors （TLR） are the two major pattern recognition receptors （PRRs） that recognize fungal components. Therefore, the purpose of the study was to analyze the expression of those PRRs and the cytokines in HaCaT cells stimulated with heat-inactivated T. rubrum conidia and hyphae, respectively. Methods HaCaT cells were unstimulated or stimulated with heat-inactivated T. rubrum conidia and hyphae （l×106 and 1.5×105 colony-forming unit （CFU） in 2 ml medium, respectively） for 6, 12 and 24 hours. The mRNA expression of PRRs involved in recognizing fungal pathogen-associated molecular patterns （PAMPs） and signaling molecules were measured by quantitative reverse transcription polymerase chain reaction （RT-PCR）. Meanwhile, surface toll-like receptor （TLR） 2, TLR4 and Dectin-1 were analyzed by fluorescence-activated cell sorter （FACS） 24 hours after treatment. The cytokines were detected in cell culture supernatants of HaCaT cells in 12 and 24 hours after treatment. Results HaCaT cells constitutively expressed mRNA of membrane-bound TLR1,2, 4 and 6, Dectinl and DC-SIGN, but not Dectin-2 or Mincle. Heat-killed T. rubrum did not significantly upregulate gene transcriptions of the PRRs of HaCaT cells. Heat-inactivated T. rubrum conidia significantly reduced the surface expression of TLR2 and Dectin-1, and suppressed the secretions of interferon-inducible protein-10 （IP-10） and monocyte chemotactic protein-1 （MCP-1） of HaCaT cells, while heat-killed T. rubrum hyphae significantly induced the secretions of IP-10 and MCP-I. Conclusion The cell-wall antigens of T. rubrum fail to activate transcriptional expression of PRRs and induce a lower immune response of HaCaT cells by limited cytokines secretion.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.81871431,82171905 and 81801828)the Tianjin Natural Science Foundation(Grant No.21JCQNJC01570 and 22JCYBJC01340)+2 种基金Tianjin Key Medical Discipline(Specialty)Construction Project(TJYXZDXK-001A)Tianjin Municipal Education Research Project(20140115)Fund for Distinguished Young Scholars of Tianjin Medical University General Hospital(22ZYYJQ03).
文摘Immune recognition of excessive neurotoxins by microglia is a trigger for the onset of neuroinflammation in the brain,leading to neurodegeneration in Alzheimer’s disease(AD).Blocking active recognition of microglia while removing neurotoxins holds promise for fundamentally alleviating neurotoxin-induced immune responses,but is very challenging.Herein,an engineered macrophage-biomimetic versatile nanoantidote(OT-Lipo@M)is developed for inflammation-targeted therapy against AD by neurotoxin neutralization and immune recognition suppression.Coating macrophage membranes can not only endow OT-Lipo@M with anti-phagocytic and inflammation-tropism capabilities to target inflammatory lesions in AD brain,but also efficiently reduce neurotoxin levels to prevent them from activating microglia.The loaded oxytocin(OT)can be slowly released to downregulate the expression of immune recognition site Toll-like receptor 4(TLR4)on microglia,inhibiting TLR4-mediated pro-inflammatory signalling cascade.Benefiting from this two-pronged immunosuppressive strategy,OT-Lipo@M exhibits outstanding therapeutic effects on ameliorating cognitive deficits,inhibiting neuronal apoptosis,and enhancing synaptic plasticity in AD mice,accompanied by the delayed hippocampal atrophy and brain microstructural disruption by in vivo 9.4T MR imaging.This work provides new insights into potential AD therapeutics targeting microglia-mediated neuroinflammation at the source.
基金This Work was supported by the grants from theFundamental Research Funds for the Central Universities （No. 10ykpy04） and the National Natural Science Foundation of China （No. 30600028）.
文摘Background Trichophyton rubrum （T. rubrum） represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested that it may result from the failure of epithelial cells to recognize T. rubrum effectively and initiate effective immune responses. The C-type lectin receptors （CLR） and toll-like receptors （TLR） are the two major pattern recognition receptors （PRRs） that recognize fungal components. Therefore, the purpose of the study was to analyze the expression of those PRRs and the cytokines in HaCaT cells stimulated with heat-inactivated T. rubrum conidia and hyphae, respectively. Methods HaCaT cells were unstimulated or stimulated with heat-inactivated T. rubrum conidia and hyphae （l×106 and 1.5×105 colony-forming unit （CFU） in 2 ml medium, respectively） for 6, 12 and 24 hours. The mRNA expression of PRRs involved in recognizing fungal pathogen-associated molecular patterns （PAMPs） and signaling molecules were measured by quantitative reverse transcription polymerase chain reaction （RT-PCR）. Meanwhile, surface toll-like receptor （TLR） 2, TLR4 and Dectin-1 were analyzed by fluorescence-activated cell sorter （FACS） 24 hours after treatment. The cytokines were detected in cell culture supernatants of HaCaT cells in 12 and 24 hours after treatment. Results HaCaT cells constitutively expressed mRNA of membrane-bound TLR1,2, 4 and 6, Dectinl and DC-SIGN, but not Dectin-2 or Mincle. Heat-killed T. rubrum did not significantly upregulate gene transcriptions of the PRRs of HaCaT cells. Heat-inactivated T. rubrum conidia significantly reduced the surface expression of TLR2 and Dectin-1, and suppressed the secretions of interferon-inducible protein-10 （IP-10） and monocyte chemotactic protein-1 （MCP-1） of HaCaT cells, while heat-killed T. rubrum hyphae significantly induced the secretions of IP-10 and MCP-I. Conclusion The cell-wall antigens of T. rubrum fail to activate transcriptional expression of PRRs and induce a lower immune response of HaCaT cells by limited cytokines secretion.
