Quinoxalin-2(1H)-ones are unique nitrogen-containing organic compounds with wide applications in the agrochemical,pharmaceutical,and chemical industries as well as in material science.During the last decades,visible-l...Quinoxalin-2(1H)-ones are unique nitrogen-containing organic compounds with wide applications in the agrochemical,pharmaceutical,and chemical industries as well as in material science.During the last decades,visible-light-promoted photoredox catalysis has emerged as a versatile platform for constructing quinoxalin-2(1H)-one scaffolds under exceptionally mild conditions.In this review,we provide an overview of recent advances in photocatalytic direct C(3)–H functionalization of quinoxaline-2(1H)-ones,including the construction of C(3)–C bonds and C(3)–R_(F)/C/O/N/Cl/S/D bonds,as well as the related reaction mechanisms.We aim to enhance the methods for the reaction of quinoxalin-2(1H)-ones at the C-3 position,which have extensive applications in organic synthesis and medicinal chemistry.展开更多
Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive as...Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive astrocytes,inhibits NSC proliferation by suppressing protein aggregate clearance through the deubiquitinating enzyme ubiquitin carboxy-terminal hydrolase L1(UCHL1)-proteasome system post-SCI.However,the potential molecular mechanism by which C3a modulates NSC activation via this pathway remains unclear.Here,we revealed that C3a/C3a receptor(C3aR)signaling activated NF-κB p65,which in turn inhibited Nrf2 activity and UCHL1 expression,resulting in diminished proteasome activity and the accumulation of protein aggregates,and ultimately impaired NSC activation.Both knockdown of NF-κB p65 and Nrf2 upregulation restored UCHL1 expression and proteasome activity in vitro,promoting NSC activation by enhancing protein aggregate clearance.Mechanistically,we found that NF-κB p65 regulated Nrf2 activity through a dual mechanism:(1)promoting Keap1-dependent ubiquitination and proteasome degradation of Nrf2;(2)inhibiting protein kinase C-mediated Nrf2 phosphorylation and nuclear translocation.Using the dual-luciferase reporter assay and chromatin immunoprecipitation(ChIP)analysis,we further identified UCHL1 as a direct transcriptional target of Nrf2.Importantly,in vivo experiments using SCI mice confirmed that either C3aR blockade,NF-κB p65 knockdown,or Nrf2 overexpression could rescue SCI-induced UCHL1 downregulation.Together,this study uncovers the C3a-NF-κB p65-Nrf2-UCHL1-proteasome axis as a critical regulator of NSC activation after SCI.This may provide novel molecular targets and intervention strategies for SCI repair.展开更多
目的:通过对C3H10T1/2细胞分化为成熟棕色脂肪细胞的培养、诱导分化及鉴定,深入探讨棕色脂肪细胞的生物学特性,为人类棕色脂肪细胞的相关研究提供实验参考与理论依据。方法:C3H10T1/2细胞经细胞接种、培养及诱导分化处理,利用光学显微...目的:通过对C3H10T1/2细胞分化为成熟棕色脂肪细胞的培养、诱导分化及鉴定,深入探讨棕色脂肪细胞的生物学特性,为人类棕色脂肪细胞的相关研究提供实验参考与理论依据。方法:C3H10T1/2细胞经细胞接种、培养及诱导分化处理,利用光学显微镜观察细胞形态变化,并通过油红O染色、免疫荧光法、线粒体探针法以及线粒体电镜技术对分化细胞进行鉴定分析。结果:未分化的C3H10T1/2细胞形态多样,具有突触伸展特征;分化后的细胞逐渐变为圆形或椭圆形,形成环形脂滴;未分化组细胞形态无明显变化。油红O染色显示,未分化组细胞基本无染色,而分化组中约90%的细胞红染,脂滴分布于细胞核周围,吸光度值显著升高(P<0.05)。分化组解偶联蛋白1(uncoupling protein 1,UCP1)、过氧化物酶体增殖激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)辅激活因子1α(PPARγco-activator-1α,PGC-1α)、PPARγ和转录因子PRDM16的相对荧光强度和蛋白表达量显著高于未分化组(P<0.05),且线粒体活性增强。结论:本研究成功诱导C3H10T1/2细胞分化为成熟棕色脂肪细胞,结合细胞形态观察、关键蛋白表达检测及线粒体功能分析进行综合评估,证实了细胞的有效分化及成熟棕色脂肪细胞的功能特性。展开更多
Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_...Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.展开更多
Objective:Aloin,the main active component in Aloe vera(L.)Burm.f.,has shown promising anti-tumor effects.This study investigated the impact of aloin in lung squamous cell carcinoma(LUSC)and explored its functional mec...Objective:Aloin,the main active component in Aloe vera(L.)Burm.f.,has shown promising anti-tumor effects.This study investigated the impact of aloin in lung squamous cell carcinoma(LUSC)and explored its functional mechanism.Methods:We analyzed the viability,migration,invasion,proliferation,and apoptosis of two LUSC cell lines after treatment with aloin.Target molecules of aloin and downstream target transcripts of nuclear receptor subfamily 3 group C member 2(NR3C2)were predicted by bioinformatics.The biological functions of NR3C2 and metallothionein 1M(MT1M)in the malignant properties of LUSC cells were determined.A co-culture system of LUSC cells with monocyte-derived macrophages was constructed.Mouse xenograft tumor models were generated to analyze the functions of aloin and NR3C2 in the tumorigenic activity of LUSC cells and macrophage polarization in vivo.Results:Aloin suppressed malignant properties of LUSC cells in vitro.However,these effects were negated by the silencing of NR3C2.NR3C2 was found to activate MT1M transcription by binding to its promoter.Additional upregulation of MT1M suppressed the malignant behavior of LUSC cells augmented by NR3C2 silencing.Analysis of the M1 and M2 markers/cytokines in the macrophages or the culture supernatant revealed that aloin treatment or MT1M overexpression in LUSC cells enhanced M1 polarization while suppressing M2 polarization of macrophages,whereas NR3C2 silencing led to reverse trends.Consistent findings were reproduced in vivo.Conclusion:This study demonstrated that aloin activates the NR3C2/MT1M axis to suppress the malignant behavior of LUSC cells and M2 macrophage polarization.Please cite this article as:Chen YN,Lu JY,Gao CF,Fang ZR,Zhou Y.Aloin blocks the malignant behavior of lung squamous cell carcinoma cells and M2 macrophage polarization by modulating the NR3C2/MT1M axis.展开更多
A novel synthesis of C2-spiroindoline derivatives based on the cascade reaction of 2-aryl-3H-indoles with cyclo- propanols is presented. The formation of product involves Rh(III)-catalyzed aryl C(sp2)—H bond alkylati...A novel synthesis of C2-spiroindoline derivatives based on the cascade reaction of 2-aryl-3H-indoles with cyclo- propanols is presented. The formation of product involves Rh(III)-catalyzed aryl C(sp2)—H bond alkylation of 2-aryl- 3H-indole, which is followed by intramolecular spiroannulation. In this tandem process, cyclopropanol acts as not only an alkylating agent but also a masked nucleophile to take part in the construction of the spirocyclic scaffold. Meanwhile, air acts as an economical and sustainable oxidant to promote the regeneration of the active catalyst. By using this method, hybrid compounds containing the central scaffolds of some clinical drugs were prepared effectively. In general, this newly developed method has advantages such as easily obtainable substrates, concise synthetic procedure, excellent atom-economy, good compatibility with diverse functional groups and ready scalability.展开更多
基金support from the National Natural Science Foundation of China(No.22101267)the China Postdoctoral Science Foundation(Nos.2021M692905 and 2024T170832)+2 种基金Natural Science Foundation of Henan Province,China(No.242300421123)Scientific Research Project of Hubei Provincial Education Department,China(No.Q20233104)Hubei Provincial Natural Science Foundation,China(No.2024AFB946).
文摘Quinoxalin-2(1H)-ones are unique nitrogen-containing organic compounds with wide applications in the agrochemical,pharmaceutical,and chemical industries as well as in material science.During the last decades,visible-light-promoted photoredox catalysis has emerged as a versatile platform for constructing quinoxalin-2(1H)-one scaffolds under exceptionally mild conditions.In this review,we provide an overview of recent advances in photocatalytic direct C(3)–H functionalization of quinoxaline-2(1H)-ones,including the construction of C(3)–C bonds and C(3)–R_(F)/C/O/N/Cl/S/D bonds,as well as the related reaction mechanisms.We aim to enhance the methods for the reaction of quinoxalin-2(1H)-ones at the C-3 position,which have extensive applications in organic synthesis and medicinal chemistry.
基金supported by the National Natural Science Foundation of China(82071362 and 82270669)Key Project of the Regional Joint Fund of Guangdong Province(2023B1515120077)+3 种基金Basic Research Program of Shenzhen Science and Technology Innovation Commission(JCYJ20210324123001003 and JCYJ20220530144801003)Shenzhen Key Laboratory of Bone Tissue Repair and Translational Research(ZDSYS20230626091402006)the Innovation and Entrepreneurship Training Program for College Students,Sun Yat-sen University(20242150)the Leading Innovation and Entrepreneurship Team Program of Zhejiang Province,China(2023R01005).
文摘Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive astrocytes,inhibits NSC proliferation by suppressing protein aggregate clearance through the deubiquitinating enzyme ubiquitin carboxy-terminal hydrolase L1(UCHL1)-proteasome system post-SCI.However,the potential molecular mechanism by which C3a modulates NSC activation via this pathway remains unclear.Here,we revealed that C3a/C3a receptor(C3aR)signaling activated NF-κB p65,which in turn inhibited Nrf2 activity and UCHL1 expression,resulting in diminished proteasome activity and the accumulation of protein aggregates,and ultimately impaired NSC activation.Both knockdown of NF-κB p65 and Nrf2 upregulation restored UCHL1 expression and proteasome activity in vitro,promoting NSC activation by enhancing protein aggregate clearance.Mechanistically,we found that NF-κB p65 regulated Nrf2 activity through a dual mechanism:(1)promoting Keap1-dependent ubiquitination and proteasome degradation of Nrf2;(2)inhibiting protein kinase C-mediated Nrf2 phosphorylation and nuclear translocation.Using the dual-luciferase reporter assay and chromatin immunoprecipitation(ChIP)analysis,we further identified UCHL1 as a direct transcriptional target of Nrf2.Importantly,in vivo experiments using SCI mice confirmed that either C3aR blockade,NF-κB p65 knockdown,or Nrf2 overexpression could rescue SCI-induced UCHL1 downregulation.Together,this study uncovers the C3a-NF-κB p65-Nrf2-UCHL1-proteasome axis as a critical regulator of NSC activation after SCI.This may provide novel molecular targets and intervention strategies for SCI repair.
文摘目的:通过对C3H10T1/2细胞分化为成熟棕色脂肪细胞的培养、诱导分化及鉴定,深入探讨棕色脂肪细胞的生物学特性,为人类棕色脂肪细胞的相关研究提供实验参考与理论依据。方法:C3H10T1/2细胞经细胞接种、培养及诱导分化处理,利用光学显微镜观察细胞形态变化,并通过油红O染色、免疫荧光法、线粒体探针法以及线粒体电镜技术对分化细胞进行鉴定分析。结果:未分化的C3H10T1/2细胞形态多样,具有突触伸展特征;分化后的细胞逐渐变为圆形或椭圆形,形成环形脂滴;未分化组细胞形态无明显变化。油红O染色显示,未分化组细胞基本无染色,而分化组中约90%的细胞红染,脂滴分布于细胞核周围,吸光度值显著升高(P<0.05)。分化组解偶联蛋白1(uncoupling protein 1,UCP1)、过氧化物酶体增殖激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)辅激活因子1α(PPARγco-activator-1α,PGC-1α)、PPARγ和转录因子PRDM16的相对荧光强度和蛋白表达量显著高于未分化组(P<0.05),且线粒体活性增强。结论:本研究成功诱导C3H10T1/2细胞分化为成熟棕色脂肪细胞,结合细胞形态观察、关键蛋白表达检测及线粒体功能分析进行综合评估,证实了细胞的有效分化及成熟棕色脂肪细胞的功能特性。
文摘Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.
基金Financial support was provided by the Research Start-up Funding of Changzhou University(No.ZMF19020381)。
文摘Objective:Aloin,the main active component in Aloe vera(L.)Burm.f.,has shown promising anti-tumor effects.This study investigated the impact of aloin in lung squamous cell carcinoma(LUSC)and explored its functional mechanism.Methods:We analyzed the viability,migration,invasion,proliferation,and apoptosis of two LUSC cell lines after treatment with aloin.Target molecules of aloin and downstream target transcripts of nuclear receptor subfamily 3 group C member 2(NR3C2)were predicted by bioinformatics.The biological functions of NR3C2 and metallothionein 1M(MT1M)in the malignant properties of LUSC cells were determined.A co-culture system of LUSC cells with monocyte-derived macrophages was constructed.Mouse xenograft tumor models were generated to analyze the functions of aloin and NR3C2 in the tumorigenic activity of LUSC cells and macrophage polarization in vivo.Results:Aloin suppressed malignant properties of LUSC cells in vitro.However,these effects were negated by the silencing of NR3C2.NR3C2 was found to activate MT1M transcription by binding to its promoter.Additional upregulation of MT1M suppressed the malignant behavior of LUSC cells augmented by NR3C2 silencing.Analysis of the M1 and M2 markers/cytokines in the macrophages or the culture supernatant revealed that aloin treatment or MT1M overexpression in LUSC cells enhanced M1 polarization while suppressing M2 polarization of macrophages,whereas NR3C2 silencing led to reverse trends.Consistent findings were reproduced in vivo.Conclusion:This study demonstrated that aloin activates the NR3C2/MT1M axis to suppress the malignant behavior of LUSC cells and M2 macrophage polarization.Please cite this article as:Chen YN,Lu JY,Gao CF,Fang ZR,Zhou Y.Aloin blocks the malignant behavior of lung squamous cell carcinoma cells and M2 macrophage polarization by modulating the NR3C2/MT1M axis.
文摘A novel synthesis of C2-spiroindoline derivatives based on the cascade reaction of 2-aryl-3H-indoles with cyclo- propanols is presented. The formation of product involves Rh(III)-catalyzed aryl C(sp2)—H bond alkylation of 2-aryl- 3H-indole, which is followed by intramolecular spiroannulation. In this tandem process, cyclopropanol acts as not only an alkylating agent but also a masked nucleophile to take part in the construction of the spirocyclic scaffold. Meanwhile, air acts as an economical and sustainable oxidant to promote the regeneration of the active catalyst. By using this method, hybrid compounds containing the central scaffolds of some clinical drugs were prepared effectively. In general, this newly developed method has advantages such as easily obtainable substrates, concise synthetic procedure, excellent atom-economy, good compatibility with diverse functional groups and ready scalability.
