AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice w...AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice werefed normal chow and high fat(HF) diets for 12 wk. The body weight was assessed once weekly. After 12 wk, the liver and serum samples were extracted. The liver tissue expression levels of RIP3, microsomal triglyceride transfer protein, protein disulfide isomerase, apolipoprotein-B, X-box binding protein-1, sterol regulatory element-binding protein-1c, fatty acid synthase, cluster of differentiation-36, diglyceride acyltransferase, peroxisome proliferator-activated receptor alpha, tumor necrosis factor-alpha(TNF-α), and interleukin-6 were assessed. Oleic acid treated primary hepatocytes from WT and RIP3 KO mice were stained with Nile red. The expression of inflammatory cytokines, including chemokine(C-X-C motif) ligand(CXCL) 1, CXCL2, and TNF-α, in monocytes was evaluated.RESULTS RIP3 KO HF diet fed mice showed a significant gain in body weight, and liver weight, liver to body weight ratio, and liver triglycerides were increased in HF diet fed RIP3 KO mice compared to HF diet fed WT mice. RIP3 KO primary hepatocytes also had increased intracellular fat droplets compared to WT primary hepatocytes after oleic acid treatment. RIP3 overexpression decreased hepatic fat content. Quantitative real-time polymerase chain reaction analysis showed that the expression of very-low-density lipoproteins secretion markers(microsomal triglyceride transfer protein, protein disulfide isomerase, and apolipoprotein-B) was significantly suppressed in RIP3 KO mice. The overall NAFLD Activity Score was the same between WT and RIP3 KO mice; however, RIP3 KO mice had increased fatty change and decreased lobular inflammation compared to WT mice. Inflammatory signals(CXCL1/2, TNF-α, and interleukin-6) increased after lipopolysaccharide and pancaspase inhibitor(necroptotic condition) treatment in monocytes. Neutrophil chemokines(CXCL1, and CXCL2) were decreased, and TNF-α was increased after RIP3 inhibitor treatment in monocytes.CONCLUSION RIP3 deletion exacerbates steatosis, and partially inhibits inflammation in the HF diet induced NAFLD model.展开更多
OBJECTIVE To explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the under⁃lying mechanisms.METHODS A rat model of ischemic stroke was established by middle cerebral artery occlusion(MCAO)...OBJECTIVE To explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the under⁃lying mechanisms.METHODS A rat model of ischemic stroke was established by middle cerebral artery occlusion(MCAO).Administration of ligustroflavone(10,30,60 mg·kg-1,ig)15 min before ischemia,after which neurological deficit score and infarct volume were detected by longa score and TTC stain.The cell viability and necrosis rate of hypoxia-cultured PC12 cells(O2/N2/CO2,1:94:5,8 h)were evaluated by MTS and LDH release rate.Flow cytometry further verified the mortality rate of PC12 cells.Necroptosis-associated proteins(RIPK1,RIPK3 and MLKL/p-MLKL)were detected by Western blotting.The interaction between RIPK3 and RIPK1 or MLKL were confirmed by immunoprecipitation.Operating Environ⁃ment(MOE)program demonstrated the possible combination of ligustroflavone with RIPK1,RIPK3 and MLKL.RESULTS Ischemic injury(increase in neurological deficit score and infarct volume)and upregulation of necroptosis-associated proteins were showed in rat MCAO model.Administration of ligustroflavone(30 mg·kg^-1,ig)evidently improved neurological func⁃tion,reduced infarct volume,and decreased the levels of necroptosis-associated proteins except the RIPK1.Consistently,hypoxia-cultured PC12 cells caused cellular injury(LDH release and necroposis)concomitant with up-regulation of necroptosis-associated proteins,and these phenomena were blocked in the presence of ligustroflavone(25μmol·L^-1)except the elevated RIPK1 levels.Using the Molecular Operating Environment(MOE)program,we identified RIPK1,RIPK3,and MLKL as potential targets of ligustroflavone.Further studies showed that the interaction between RIPK3 and RIPK1 or MLKL was significantly enhanced,which was blocked in the presence of ligustroflavone.CONCLUSION Ligus⁃troflavone protects rat brain from ischemic injury,and its beneficial effect is related to the prevention of necroptosis through a mechanism involving targeting RIPK1,RIPK3,and/or MLKL.展开更多
Mixed lineage leukemia(MLL)is an aggressive and refractory blood cancer that predominantly occurs in pediatric patients and is often associated with poor prognosis and dismal outcomes.Thus far,no effective target ther...Mixed lineage leukemia(MLL)is an aggressive and refractory blood cancer that predominantly occurs in pediatric patients and is often associated with poor prognosis and dismal outcomes.Thus far,no effective target therapy for the treatment of MLL leukemia is available.MLL leukemia is caused by the rearrangement of MLL genes at 11q23,which generates various MLL chimeric proteins that promote leukemogenesis through transcriptional misregulation of MLL target genes.Biochemical studies on MLL chimeras have identified that the most common partners exist in the superelongation complex(SEC)and DOT1L complex,which activate or sustain MLL target gene expression through processive transcription elongation.The results of these studies indicate a transcription-related mechanism for MLL leukemogenesis and maintenance.In this study,we first review the history of MLL leukemia and its related clinical features.Then,we discuss the biological functions of MLL and MLL chimeras,significant cooperating events,and transcriptional addiction mechanisms in MLL leukemia with an emphasis on potential and rational therapy development.Collectively,we believe that targeting the transcriptional addiction mediated by SEC and the DOT1L complex will provide new avenues for target therapies in MLL leukemia and serve as a novel paradigm for targeting transcriptional addiction in other cancers.展开更多
目的构建呼吸道合胞病毒(RSV)感染气液相界面(ALI)培养的人支气管上皮细胞(hBEC)模型,为深入研究呼吸道病毒致病机制提供更接近体内环境的细胞模型;通过分析RSV感染对高迁移率族蛋白1(HMGB1)和磷酸化混合系列蛋白激酶样结构域(pMLKL)表...目的构建呼吸道合胞病毒(RSV)感染气液相界面(ALI)培养的人支气管上皮细胞(hBEC)模型,为深入研究呼吸道病毒致病机制提供更接近体内环境的细胞模型;通过分析RSV感染对高迁移率族蛋白1(HMGB1)和磷酸化混合系列蛋白激酶样结构域(pMLKL)表达的影响,探讨RSV感染损伤支气管上皮的致病机制。方法将hBEC接种到Transwell膜上,进行液体浸没式培养,细胞汇合度达100%后转ALI培养,倒置显微镜观察细胞生长状态。细胞分化成熟后按照以下分组分别感染RSV病毒:6 h对照组,6 h感染复数(MOI)1.0组,6 h MOI 3.0组,24 h对照组,24 h MOI 1.0组,24 h MOI 3.0组。每组3个复孔。通过免疫荧光染色确认RSV感染效果和RSV感染对细胞核蛋白HMGB1和pMLKL表达的影响。结果经细胞扩展期液体浸没式培养4~10 d后,细胞汇合度达100%。转ALI培养约4周后,细胞条索状分布越来越清晰,且分泌肉眼可见的黏液,形成黏液层,将Transwell膜石蜡包埋切片,得到典型的假复层上皮HE染色结果。经抗RSV抗体免疫荧光染色确认,MOI为3.0感染24 h RSV病毒成功感染细胞;抗HMGB1和抗pMLKL免疫荧光双染色结果显示,该感染条件下,细胞核内出现粉色荧光[为蓝色4',6-二脒基-2-苯基吲哚(DAPI)和红色HMGB1荧光Merge结果],证实RSV感染后出现HMGB1核表达;而RSV感染前后均未见pMLKL表达。结论通过在Transwell膜上液体浸没式扩展培养和ALI分化培养,可获得分化良好的hBEC,且能较长时间维持其形态及功能,可为呼吸道病毒感染及其他常见呼吸道疾病研究提供更接近体内环境的细胞模型。在MOI 3.024 h条件下,RSV成功感染该细胞模型,并引起损伤相关分子蛋白HMGB1核表达。展开更多
基金Supported by National Research Foundation of Korea(NRF)funded by the South Korean Government,No.NRF-2017M3A9C8028794
文摘AIM To validate the effects of receptor interacting protein kinase-3(RIP3) deletion in non-alcoholic fatty liver disease(NAFLD) and to clarify the mechanism of action.METHODS Wild-type(WT) and RIP3 knockout(KO) mice werefed normal chow and high fat(HF) diets for 12 wk. The body weight was assessed once weekly. After 12 wk, the liver and serum samples were extracted. The liver tissue expression levels of RIP3, microsomal triglyceride transfer protein, protein disulfide isomerase, apolipoprotein-B, X-box binding protein-1, sterol regulatory element-binding protein-1c, fatty acid synthase, cluster of differentiation-36, diglyceride acyltransferase, peroxisome proliferator-activated receptor alpha, tumor necrosis factor-alpha(TNF-α), and interleukin-6 were assessed. Oleic acid treated primary hepatocytes from WT and RIP3 KO mice were stained with Nile red. The expression of inflammatory cytokines, including chemokine(C-X-C motif) ligand(CXCL) 1, CXCL2, and TNF-α, in monocytes was evaluated.RESULTS RIP3 KO HF diet fed mice showed a significant gain in body weight, and liver weight, liver to body weight ratio, and liver triglycerides were increased in HF diet fed RIP3 KO mice compared to HF diet fed WT mice. RIP3 KO primary hepatocytes also had increased intracellular fat droplets compared to WT primary hepatocytes after oleic acid treatment. RIP3 overexpression decreased hepatic fat content. Quantitative real-time polymerase chain reaction analysis showed that the expression of very-low-density lipoproteins secretion markers(microsomal triglyceride transfer protein, protein disulfide isomerase, and apolipoprotein-B) was significantly suppressed in RIP3 KO mice. The overall NAFLD Activity Score was the same between WT and RIP3 KO mice; however, RIP3 KO mice had increased fatty change and decreased lobular inflammation compared to WT mice. Inflammatory signals(CXCL1/2, TNF-α, and interleukin-6) increased after lipopolysaccharide and pancaspase inhibitor(necroptotic condition) treatment in monocytes. Neutrophil chemokines(CXCL1, and CXCL2) were decreased, and TNF-α was increased after RIP3 inhibitor treatment in monocytes.CONCLUSION RIP3 deletion exacerbates steatosis, and partially inhibits inflammation in the HF diet induced NAFLD model.
基金National Natural Science Foundation of China(8157343081872873)Hunan Provincial Natural Science Foundation of China(2015JJ2156)
文摘OBJECTIVE To explore the effect of ligustroflavone on ischemic brain injury in stroke rat and the under⁃lying mechanisms.METHODS A rat model of ischemic stroke was established by middle cerebral artery occlusion(MCAO).Administration of ligustroflavone(10,30,60 mg·kg-1,ig)15 min before ischemia,after which neurological deficit score and infarct volume were detected by longa score and TTC stain.The cell viability and necrosis rate of hypoxia-cultured PC12 cells(O2/N2/CO2,1:94:5,8 h)were evaluated by MTS and LDH release rate.Flow cytometry further verified the mortality rate of PC12 cells.Necroptosis-associated proteins(RIPK1,RIPK3 and MLKL/p-MLKL)were detected by Western blotting.The interaction between RIPK3 and RIPK1 or MLKL were confirmed by immunoprecipitation.Operating Environ⁃ment(MOE)program demonstrated the possible combination of ligustroflavone with RIPK1,RIPK3 and MLKL.RESULTS Ischemic injury(increase in neurological deficit score and infarct volume)and upregulation of necroptosis-associated proteins were showed in rat MCAO model.Administration of ligustroflavone(30 mg·kg^-1,ig)evidently improved neurological func⁃tion,reduced infarct volume,and decreased the levels of necroptosis-associated proteins except the RIPK1.Consistently,hypoxia-cultured PC12 cells caused cellular injury(LDH release and necroposis)concomitant with up-regulation of necroptosis-associated proteins,and these phenomena were blocked in the presence of ligustroflavone(25μmol·L^-1)except the elevated RIPK1 levels.Using the Molecular Operating Environment(MOE)program,we identified RIPK1,RIPK3,and MLKL as potential targets of ligustroflavone.Further studies showed that the interaction between RIPK3 and RIPK1 or MLKL was significantly enhanced,which was blocked in the presence of ligustroflavone.CONCLUSION Ligus⁃troflavone protects rat brain from ischemic injury,and its beneficial effect is related to the prevention of necroptosis through a mechanism involving targeting RIPK1,RIPK3,and/or MLKL.
基金supported by grant from the“Thousand Young Talent Program”awarded to K.L.
文摘Mixed lineage leukemia(MLL)is an aggressive and refractory blood cancer that predominantly occurs in pediatric patients and is often associated with poor prognosis and dismal outcomes.Thus far,no effective target therapy for the treatment of MLL leukemia is available.MLL leukemia is caused by the rearrangement of MLL genes at 11q23,which generates various MLL chimeric proteins that promote leukemogenesis through transcriptional misregulation of MLL target genes.Biochemical studies on MLL chimeras have identified that the most common partners exist in the superelongation complex(SEC)and DOT1L complex,which activate or sustain MLL target gene expression through processive transcription elongation.The results of these studies indicate a transcription-related mechanism for MLL leukemogenesis and maintenance.In this study,we first review the history of MLL leukemia and its related clinical features.Then,we discuss the biological functions of MLL and MLL chimeras,significant cooperating events,and transcriptional addiction mechanisms in MLL leukemia with an emphasis on potential and rational therapy development.Collectively,we believe that targeting the transcriptional addiction mediated by SEC and the DOT1L complex will provide new avenues for target therapies in MLL leukemia and serve as a novel paradigm for targeting transcriptional addiction in other cancers.
文摘目的构建呼吸道合胞病毒(RSV)感染气液相界面(ALI)培养的人支气管上皮细胞(hBEC)模型,为深入研究呼吸道病毒致病机制提供更接近体内环境的细胞模型;通过分析RSV感染对高迁移率族蛋白1(HMGB1)和磷酸化混合系列蛋白激酶样结构域(pMLKL)表达的影响,探讨RSV感染损伤支气管上皮的致病机制。方法将hBEC接种到Transwell膜上,进行液体浸没式培养,细胞汇合度达100%后转ALI培养,倒置显微镜观察细胞生长状态。细胞分化成熟后按照以下分组分别感染RSV病毒:6 h对照组,6 h感染复数(MOI)1.0组,6 h MOI 3.0组,24 h对照组,24 h MOI 1.0组,24 h MOI 3.0组。每组3个复孔。通过免疫荧光染色确认RSV感染效果和RSV感染对细胞核蛋白HMGB1和pMLKL表达的影响。结果经细胞扩展期液体浸没式培养4~10 d后,细胞汇合度达100%。转ALI培养约4周后,细胞条索状分布越来越清晰,且分泌肉眼可见的黏液,形成黏液层,将Transwell膜石蜡包埋切片,得到典型的假复层上皮HE染色结果。经抗RSV抗体免疫荧光染色确认,MOI为3.0感染24 h RSV病毒成功感染细胞;抗HMGB1和抗pMLKL免疫荧光双染色结果显示,该感染条件下,细胞核内出现粉色荧光[为蓝色4',6-二脒基-2-苯基吲哚(DAPI)和红色HMGB1荧光Merge结果],证实RSV感染后出现HMGB1核表达;而RSV感染前后均未见pMLKL表达。结论通过在Transwell膜上液体浸没式扩展培养和ALI分化培养,可获得分化良好的hBEC,且能较长时间维持其形态及功能,可为呼吸道病毒感染及其他常见呼吸道疾病研究提供更接近体内环境的细胞模型。在MOI 3.024 h条件下,RSV成功感染该细胞模型,并引起损伤相关分子蛋白HMGB1核表达。
文摘坏死性凋亡(Necroptosis)在炎症性、免疫性和神经退行性等疾病的发病机制中起着重要作用,参与了慢性肾脏病(CKD)的发生发展,但其明确的分子机制还没有被完全阐明。热休克蛋白90 (HSP90)作为一种重要的分子伴侣,底物蛋白种类繁多,广泛参与诸多生命活动,在维持细胞内蛋白质稳态方面起到关键的调节作用。随着研究的深入,研究者发现坏死性凋亡途径中的核心组成部分受体相互作用蛋白1 (RIP1)、受体相互作用蛋白3(RIP3)和混合谱系激酶结构域样蛋白(MLKL)均受到热休克蛋白90的调控。而天然产物Kongensin A (KA)是一种热休克蛋白90抑制剂,热休克蛋白90受到抑制后进而阻断了坏死性凋亡途径。进一步研究坏死性凋亡途径及其对慢性肾脏病的影响,必将为慢性肾脏病的防治提供新的靶点。
