We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repet...We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.展开更多
14-3-3 is a highly conserved acidic protein family, composed of seven isoforms in mammals. 14-3-3 protein caninteract with over 200 target proteins by phosphoserine-dependent and phosphoserine-independent manners. Lit...14-3-3 is a highly conserved acidic protein family, composed of seven isoforms in mammals. 14-3-3 protein caninteract with over 200 target proteins by phosphoserine-dependent and phosphoserine-independent manners. Little isknown about the consequences of these interactions, and thus are the subjects of ongoing studies. 14-3-3 controls cellcycle, cell growth, differentiation, survival, apoptosis, migration and spreading. Recent studies have revealed newmechanisms and new functions of 14-3-3, giving us more insights on this fascinating and complex family of proteins.Of all the seven isoforms, 14-3-3σ seems to be directly involved in human cancer. 14-3-3σ itself is subject to regulationby p53 upon DNA damage and by epigenetic deregulation. Gene silencing of 14-3-3σ by CpG methylation has beenfound in many human cancer types. This suggests that therapy-targeting 14-3-3σ may be beneficial for future cancertreatment.展开更多
Seven different, but highly conserved 14-3-3 proteins are involved in diverse signaling pathways in human cells. It isunclear how the 14-3-3σ isoform, a transcriptional target of p53, exerts its inhibitory effect on ...Seven different, but highly conserved 14-3-3 proteins are involved in diverse signaling pathways in human cells. It isunclear how the 14-3-3σ isoform, a transcriptional target of p53, exerts its inhibitory effect on the cell cycle in thepresence of other 14-3-3 isoforms, which are constitutively expressed at high levels. In order to identify structuraldifferences between the 14-3-3 isoforms, we solved the crystal structure of the human 14-3-3σ protein at a resolutionof 2.8 ? and compared it to the known structures of 14-3-3ζ and 14-3-3τ. The global architecture of the 14-3-3σ foldis similar to the previously determined structures of 14-3-3ζ and 14-3-3τ: two 14-3-3σ molecules form a cup-shapeddimer. Significant differences between these 14-3-3 isoforms were detected adjacent to the amphipathic groove, whichmediates the binding to phosphorylated consensus motifs in 14-3-3-ligands. Another specificity determining region islocalized between amino-acids 203 to 215. These differences presumably select for the interaction with specific ligands,which may explain the different biological functions of the respective 14-3-3 isoforms. Furthermore, the two 14-3-3σmolecules forming a dimer differ by the spatial position of the ninth helix, which is shifted to the inside of the ligandinteraction surface, thus indicating adaptability of this part of the molecule. In addition, 5 non-conserved residues arelocated at the interface between two 14-3-3σ proteins forming a dimer and represent candidate determinants of homo-and hetero-dimerization specificity. The structural differences among the 14-3-3 isoforms described here presumablycontribute to isoform-specific interactions and functions.展开更多
基金supported by the Haihe Laboratory of Cell Ecosystem Innovation Fund,No.22HHXBSS00047(to PL)the National Natural Science Foundation of China,Nos.82072166(to PL),82071394(to XG)+4 种基金Science and Technology Planning Project of Tianjin,No.20YFZCSY00030(to PL)Science and Technology Project of Tianjin Municipal Health Commission,No.TJWJ2021QN005(to XG)Tianjin Key Medical Discipline(Specialty)Construction Project,No.TJYXZDXK-006ATianjin Municipal Education Commission Scientific Research Program Project,No.2020KJ164(to JZ)China Postdoctoral Science Foundation,No.2022M712392(to ZY).
文摘We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.
文摘【目的】构建家蝇Musca domestica酵母双杂交cDNA文库,筛选MD14-3-3互作蛋白。【方法】以家蝇为研究对象,经mRNA纯化、cDNA初级文库构建、重组pGADT7-DEST构建次级文库,构建酵母双杂交筛选系统,构建pGBKT7-MD14-3-3质粒作为诱饵筛选与MD14-3-3相互作用的蛋白,并进行回转验证。【结果】成功构建文库容量为1.6×10^(7) CFU,重组率为100%的家蝇酵母双杂交cDNA文库。酵母双杂交筛选获得2个靶蛋白,回转试验表明mucin-like protein HKR1与抗菌肽ctenidin-1为MD14-3-3的互作蛋白。【结论】从成功构建的家蝇酵母双杂交cDNA文库中筛选出MD14-3-3蛋白的2个互作蛋白,为进一步探究家蝇免疫应答机制奠定了基础。
文摘14-3-3 is a highly conserved acidic protein family, composed of seven isoforms in mammals. 14-3-3 protein caninteract with over 200 target proteins by phosphoserine-dependent and phosphoserine-independent manners. Little isknown about the consequences of these interactions, and thus are the subjects of ongoing studies. 14-3-3 controls cellcycle, cell growth, differentiation, survival, apoptosis, migration and spreading. Recent studies have revealed newmechanisms and new functions of 14-3-3, giving us more insights on this fascinating and complex family of proteins.Of all the seven isoforms, 14-3-3σ seems to be directly involved in human cancer. 14-3-3σ itself is subject to regulationby p53 upon DNA damage and by epigenetic deregulation. Gene silencing of 14-3-3σ by CpG methylation has beenfound in many human cancer types. This suggests that therapy-targeting 14-3-3σ may be beneficial for future cancertreatment.
文摘Seven different, but highly conserved 14-3-3 proteins are involved in diverse signaling pathways in human cells. It isunclear how the 14-3-3σ isoform, a transcriptional target of p53, exerts its inhibitory effect on the cell cycle in thepresence of other 14-3-3 isoforms, which are constitutively expressed at high levels. In order to identify structuraldifferences between the 14-3-3 isoforms, we solved the crystal structure of the human 14-3-3σ protein at a resolutionof 2.8 ? and compared it to the known structures of 14-3-3ζ and 14-3-3τ. The global architecture of the 14-3-3σ foldis similar to the previously determined structures of 14-3-3ζ and 14-3-3τ: two 14-3-3σ molecules form a cup-shapeddimer. Significant differences between these 14-3-3 isoforms were detected adjacent to the amphipathic groove, whichmediates the binding to phosphorylated consensus motifs in 14-3-3-ligands. Another specificity determining region islocalized between amino-acids 203 to 215. These differences presumably select for the interaction with specific ligands,which may explain the different biological functions of the respective 14-3-3 isoforms. Furthermore, the two 14-3-3σmolecules forming a dimer differ by the spatial position of the ninth helix, which is shifted to the inside of the ligandinteraction surface, thus indicating adaptability of this part of the molecule. In addition, 5 non-conserved residues arelocated at the interface between two 14-3-3σ proteins forming a dimer and represent candidate determinants of homo-and hetero-dimerization specificity. The structural differences among the 14-3-3 isoforms described here presumablycontribute to isoform-specific interactions and functions.
