The microtubule preprophase bands （PPBs） participate in the sequence of events to position cell plates in most plants. However, the mechanism of PPB formation remains to be clarified. In the present study, the organ...The microtubule preprophase bands （PPBs） participate in the sequence of events to position cell plates in most plants. However, the mechanism of PPB formation remains to be clarified. In the present study, the organization of PPBs in Arabidopsis suspension cultured cells was investigated by confocal laser scanning microscopy combined with pharmacological treatments of reagents specific for the cytoskeleton elements. Double staining of F-actin and microtubules （MTs） showed that actin filaments were arranged randomly and no colocalization with cortical MTs was observed in the interphase cells. However, cortical actin filaments showed colocalization with MTs during the formation of PPBs. A broad actin band formed with the broad MT band in the initiation of PPB and narrowed down together with the MT band to form the PPB. Nevertheless, broad MT bands were formed but failed to narrow down in cells treated with the F-actin disruptor latrunculin A. In contrast, in the presence of the F-actin stabilizer phalloidin, PPB formation did not exhibit any abnormality. Therefore, the integrity, but not the dynamics, of the actin cytoskeleton is necessary for the formation of normal PPBs. Treatment with 2, 3-butanedine monoxime, a myosin inhibitor, also resulted in the formation of broad MT bands, indicating that actomyosin may be involved in the rearrangement of MTs to form the PPBs. Double staining of MTs and myosin revealed that myosin concentrated on the PPB region during PPB formation. It is suggested that the actin cytoskeleton at the PPB site may serve as a rack to transport cortical MTs by using myosin when the broad MT band narrows down to form the PPB.展开更多
Catalytic hydrogenation of diacetyl monoxime to tetramethylpyrazine, by the homogeneous catalysts generated in situ from some transition metal chlorides with triphenylphosphine in ethanol under H-2 pressure of 0.6 sim...Catalytic hydrogenation of diacetyl monoxime to tetramethylpyrazine, by the homogeneous catalysts generated in situ from some transition metal chlorides with triphenylphosphine in ethanol under H-2 pressure of 0.6 similar to 4.6 MPa at 100 similar to 150 degrees C, has been studied. The optimum H-2 partial pressure was observed at about 1.3 MPa. The maximum conversion of diacetyl monoxime and yield of tetramethylpyrazine were 97% and 90%, respectively.展开更多
Alzheimer's disease(AD)is an irreversible neurodegenerative disorder,which is pathologically characterized by the deposits of β-amyloid(Aβ),and plays an important role in neuronal death.Indirubin-30-monoxime(I3M...Alzheimer's disease(AD)is an irreversible neurodegenerative disorder,which is pathologically characterized by the deposits of β-amyloid(Aβ),and plays an important role in neuronal death.Indirubin-30-monoxime(I3M)showed neuroprotective effects against Aβ-induced neuronal apoptosis.However,the use of I3M in AD treatment is limited due to its low bioavailability.Herein,PLGA-PEG nanoparticles were synthesized for I3M loading.I3M could release sustainedly sustain release from the I3M-loaded PLGA-PEG nanoparticles(PLGA-PEG-I3M NPs)without obvious burst release.What's more,the PLGA-PEG-I3M NPs could significantly promote the uptake of I3M by PC12 cells through nanoparticle-mediated transport,and improve the efficacy of I3M on the inhibition of Aβfibrillization and oligomerization as well as the neuroprotective activity of I3M on Aβoligomers-induced neuronal death.Thus,the PLGA-PEG-I3M NPs may be a promising platform for AD therapy.展开更多
Background Multidrug resistance （MDR） is a main reason for paclitaxel （TAX） treatment failure. Indirubin-3＇-monoxime （IRO） and Matrine are traditional Chinese medicines, which may reverse the resistance of tumo...Background Multidrug resistance （MDR） is a main reason for paclitaxel （TAX） treatment failure. Indirubin-3＇-monoxime （IRO） and Matrine are traditional Chinese medicines, which may reverse the resistance of tumor cells to some chemotherapy drugs, but the relationship between paclitaxel resistance and Matrine is still unclear. The aim of this study was to explore the potential molecular mechanism of IRO and Matrine in reversal of TAX resistance. Methods In this study, MTT assay was used to measure the non-cytotoxic dosage of IRO and Matrine on NCI-H520/TAX25 cells and determine the reversal extent of TAX resistance under non-toxic doses. In addition, RT-PCR and Western blotting were used to evaluate the mRNA expression and the protein level of survivin, Oct-4, and Sox-2 in NCI-H520fTAX25 ceils using semi-quantitative methods. Results There was no obvious inhibition on sensitive cell strains and drug-resistant strains, when the final concentration was at lest 4 IJmol/L for IRO and 100 IJmol/L for Matrine. So 4 tJmol/L of IRO and 100 pmol/L of Matrine were considered as the reversal dosage. When 4 IJmol/L of IRO or 100 pmol/L of Matrine were used together with TAX, the sensitivity to TAX increased evidently in NCI-H520/TAX2 cells; the reversal rate of IRO and Matrine was about 1.92 （43.56/22.6 nmol/L） and 1.74 （43.56/25.0 nmol/L）, respectively. The mRNA expression and the protein ievel of survivin, Oct-4, and Sox-2 in NCI-H520/TAX25 decreased significantly （P 〈0.05） after addition of IRO or Matrine in TAX treatment, compared to that of TAX treatment alone. Conclusion The decrease in both mRNA expression and protein level of survivin, Oct-4, and Sox-2 might be the molecular mechanism, by which IRO and Matrine mediate the reversal of TAX resistance.展开更多
基金Supported by the State Key Basic Research and Development Plan of China （2006CB100101） and the National Natural Science Foundation of China （30421002, 30370707 and 30100091 ）.
文摘The microtubule preprophase bands （PPBs） participate in the sequence of events to position cell plates in most plants. However, the mechanism of PPB formation remains to be clarified. In the present study, the organization of PPBs in Arabidopsis suspension cultured cells was investigated by confocal laser scanning microscopy combined with pharmacological treatments of reagents specific for the cytoskeleton elements. Double staining of F-actin and microtubules （MTs） showed that actin filaments were arranged randomly and no colocalization with cortical MTs was observed in the interphase cells. However, cortical actin filaments showed colocalization with MTs during the formation of PPBs. A broad actin band formed with the broad MT band in the initiation of PPB and narrowed down together with the MT band to form the PPB. Nevertheless, broad MT bands were formed but failed to narrow down in cells treated with the F-actin disruptor latrunculin A. In contrast, in the presence of the F-actin stabilizer phalloidin, PPB formation did not exhibit any abnormality. Therefore, the integrity, but not the dynamics, of the actin cytoskeleton is necessary for the formation of normal PPBs. Treatment with 2, 3-butanedine monoxime, a myosin inhibitor, also resulted in the formation of broad MT bands, indicating that actomyosin may be involved in the rearrangement of MTs to form the PPBs. Double staining of MTs and myosin revealed that myosin concentrated on the PPB region during PPB formation. It is suggested that the actin cytoskeleton at the PPB site may serve as a rack to transport cortical MTs by using myosin when the broad MT band narrows down to form the PPB.
文摘Catalytic hydrogenation of diacetyl monoxime to tetramethylpyrazine, by the homogeneous catalysts generated in situ from some transition metal chlorides with triphenylphosphine in ethanol under H-2 pressure of 0.6 similar to 4.6 MPa at 100 similar to 150 degrees C, has been studied. The optimum H-2 partial pressure was observed at about 1.3 MPa. The maximum conversion of diacetyl monoxime and yield of tetramethylpyrazine were 97% and 90%, respectively.
基金Thanks for the funding by National Natural Science Foundation of China(Grant No.81870853)Natural Science Foundation of Zhejiang Province(Grant No.LY21H090002)+6 种基金Natural Science Foundation of Ningbo(Grant No.2018A610313)Natural Science Foundation of Guangdong(Grant No.2019A1515011750,2021A1515010720)Major program of Ningbo Science and Technology Innovation 2025(Grant No.2019B1006)Ningbo municipal innovation team of life science and health(Grant No.2015C110026)Basic scientific research operating expenses of provincial universities(Grant No.SJLY2021002)Science and Technology Innovation Commission of Shenzhen(Grant No.ZDSYS20200811142600003,JCYJ20180507183036060,JCYJ20190806161409092,JCYJ20210324103012033,JCYJ20180228162928828)LiDakSum Marine Biopharmaceutical Development Fund,the K.C.Wong Magna Fund in Ningbo University and the Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province.
文摘Alzheimer's disease(AD)is an irreversible neurodegenerative disorder,which is pathologically characterized by the deposits of β-amyloid(Aβ),and plays an important role in neuronal death.Indirubin-30-monoxime(I3M)showed neuroprotective effects against Aβ-induced neuronal apoptosis.However,the use of I3M in AD treatment is limited due to its low bioavailability.Herein,PLGA-PEG nanoparticles were synthesized for I3M loading.I3M could release sustainedly sustain release from the I3M-loaded PLGA-PEG nanoparticles(PLGA-PEG-I3M NPs)without obvious burst release.What's more,the PLGA-PEG-I3M NPs could significantly promote the uptake of I3M by PC12 cells through nanoparticle-mediated transport,and improve the efficacy of I3M on the inhibition of Aβfibrillization and oligomerization as well as the neuroprotective activity of I3M on Aβoligomers-induced neuronal death.Thus,the PLGA-PEG-I3M NPs may be a promising platform for AD therapy.
文摘Background Multidrug resistance （MDR） is a main reason for paclitaxel （TAX） treatment failure. Indirubin-3＇-monoxime （IRO） and Matrine are traditional Chinese medicines, which may reverse the resistance of tumor cells to some chemotherapy drugs, but the relationship between paclitaxel resistance and Matrine is still unclear. The aim of this study was to explore the potential molecular mechanism of IRO and Matrine in reversal of TAX resistance. Methods In this study, MTT assay was used to measure the non-cytotoxic dosage of IRO and Matrine on NCI-H520/TAX25 cells and determine the reversal extent of TAX resistance under non-toxic doses. In addition, RT-PCR and Western blotting were used to evaluate the mRNA expression and the protein level of survivin, Oct-4, and Sox-2 in NCI-H520fTAX25 ceils using semi-quantitative methods. Results There was no obvious inhibition on sensitive cell strains and drug-resistant strains, when the final concentration was at lest 4 IJmol/L for IRO and 100 IJmol/L for Matrine. So 4 tJmol/L of IRO and 100 pmol/L of Matrine were considered as the reversal dosage. When 4 IJmol/L of IRO or 100 pmol/L of Matrine were used together with TAX, the sensitivity to TAX increased evidently in NCI-H520/TAX2 cells; the reversal rate of IRO and Matrine was about 1.92 （43.56/22.6 nmol/L） and 1.74 （43.56/25.0 nmol/L）, respectively. The mRNA expression and the protein ievel of survivin, Oct-4, and Sox-2 in NCI-H520/TAX25 decreased significantly （P 〈0.05） after addition of IRO or Matrine in TAX treatment, compared to that of TAX treatment alone. Conclusion The decrease in both mRNA expression and protein level of survivin, Oct-4, and Sox-2 might be the molecular mechanism, by which IRO and Matrine mediate the reversal of TAX resistance.
