Soft rot is a destructive disease that inflicts significant losses on agricultural production and the economy post-harvest.Biocontrol strategies based on antagonistic microorganisms have a broad application prospect t...Soft rot is a destructive disease that inflicts significant losses on agricultural production and the economy post-harvest.Biocontrol strategies based on antagonistic microorganisms have a broad application prospect to fight against plant pathogens.This study utilized fluorescence-activated droplet sorting(FADS)technology as an alternative to traditional plate culture methods to isolate microorganisms with antagonistic activity against the soft rot pathogen Erwinia carotovora Ecc15.Initially,the culture performance of the FADS platform was evaluated by analyzing bacterial diversity in droplet culture samples and agar plate culture samples,our data showed that droplet culture exhibited higher species richness and diversity than plate culture,and more than 95%of the operational taxonomic units(OTUs)in the droplet samples belonged to the rare biosphere.Additionally,we developed a green fluorescent protein(GFP)-Ecc15-based FADS screening system,which achieved an enrichment ratio of up to 148.Using this system,we successfully screened 32 antagonistic bacteria from rhizosphere soil sample of healthy konjac plants,and some may be novel microbial resources,including the genera Lelliottia,Buttiauxella and Leclercia.Notably,strain D-62 exhibited the strongest antibacterial ability against Ecc15,with an inhibition zone diameter of(20.86±1.56)mm.In vivo experiments conducted on the corms of Amorphophallus konjac demonstrated that strain D-62 could effectively reduce the infection ability of Ecc15 to the corms,indicating that strain D-62 has the potential to be developed as a biocontrol agent.Our findings suggested that the FADS screening system showed a screening efficiency approximately 3×10^(3)times higher than plate screening system,while significantly reducing costs of infrastructure,labor and consumables,it provides theoretical guidance for the screening of other plant pathogen biocontrol bacteria.展开更多
Mesenchymal stem cells （MSCs） are a promising tool in regenerative medicine due to their capacity to differentiate into multiple lineages. In addition to MSCs isolated from bone marrow （BMSCs）, adult MSCs are isol...Mesenchymal stem cells （MSCs） are a promising tool in regenerative medicine due to their capacity to differentiate into multiple lineages. In addition to MSCs isolated from bone marrow （BMSCs）, adult MSCs are isolated from craniofacial tissues including dental pulp tissues （DPs） using various stem cell surface markers. However, there has been a lack of consensus on a set of surface makers that are reproducibly effective at isolating putative multipotent dental mesenchymal stem cel^s （~M^Cs）. II1 ~his stucly, we used clif^et（~nt combinations of surface markers （CD51/CD140a, CD271, and STRO-1/CD146） to isolate homogeneous populations of DMSCs from heterogeneous dental pulp cells （DPCs） obtained from DP and compared their capacity to undergo multilineage differentiation. Fluorescence-activated cell sorting revealed that 27.3% of DPCs were CD51＋/CD140a＋, 10.6% were CD271＋, and 0.3% were STRO-1＋/CD146＋. Under odontogenic conditions, all three subsets of isolated DMSCs exhibited differentiation capacity into odontogenic lineages. Among these isolated subsets of DMSCs, CD271＋ DMSCs demonstrated the greatest odontogenic potential. While all three combinations of surface markers in this study successfully isolated DMSCs from DPCs, the single CD271 marker presents the most effective stem cell surface marker for identification of DMSCs with high odontogenic potential. Isolated CD271＋ DMSCs could potentially be utilized for future clinical applications in dentistry and regenerative medicine.展开更多
BACKGROUND： Previous studies have demonstrated that brain-derived neurotrophic factor （BDNF） promotes neural differentiation. However, the mechanisms involved in cell cycle-related protein regulation, which highly ...BACKGROUND： Previous studies have demonstrated that brain-derived neurotrophic factor （BDNF） promotes neural differentiation. However, the mechanisms involved in cell cycle-related protein regulation, which highly correlates to neural proliferation and apoptosis, remain poorly understood. OBJECTIVE： To investigate the effects of various concentrations of BDNF on cycle-related protein mRNA expression in induce-differentiated SH-SY5Y cells in vitro prior to and following G2 phase, and to analyze the neuroprotective effects of BDNF. DESIGN, TIME AND SETTING： A comparison, observational study, based on cell biology, was performed at the Department of Biochemistry, Medical College of Tongji University, from March 2005 to October 2006. MATERIALS： SH-SY5Y cells were provided by Shanghai Institute of Cytology, Chinese Academy of Science; BDNF by Alomone Labs, Israel; all-trans retinoic acid （ATRA） by Sigma-Aldrich, USA. METHODS： SH-SY5Y cells were randomly divided into three groups： blank control [cells were treated in Insulin-Transferrin-Selenium （ITS） solution for 7 days], ATRA （cells were treated with ITS solution containing 10 μmol/L ATRA for 7 days）, and BDNF （cells were treated identical to the ATRA group for 5 days, and then respectively treated in ITS solution containing 1, 10, and 100 μg/L BDNF for 2 days）. The experiment was repeated three times for each group. MAIN OUTCOME MEASURES： mRNA expression levels of cyclin A1, B1, B2, cyclin-dependent kinase 1, and 5 were detected using quantitative real-time RT-PCR; percentage of cells in G1, S, and G2 phases were detected using fluorescence-activated cell sorting. RESULTS： mRNA expression levels of cyclin A1 in the high-dose BDNF group was significantly less than the ATRA group （P 〈 0.05）.mRNA expression levels of cyclin B1 was significantly less in the different BDNF concentration groups compared with the control and ATRA groups （P 〈 0.05 or P 〈 0.01）. mRNA expression levels of cyclin B2 and cyclin-dependent kinase 1 were significantly decreased in the high-dose BDNF group （P 〈 0.05 or P 〈 0.01）. Cyclin-dependent kinase 5 mRNA expression was significantly greater in the low-dose and moderate-dose BDNF groups compared with the ATRA group （P 〈 0.05）. The percentage of cells in G1 phase was significantly greater in the different BDNF concentration groups compared with the ATRA and control groups （P 〈 0.01）. Moreover, the percentage of cells in S phase was significantly less in the three BDNF groups compared with the ATRA group （P 〈 0.01）. However, the percentage of cells in S phase was significantly less in the low-dose and high-dose BDNF groups compared with the control group （P 〈 0.01）. CONCLUSION： BDNF enhanced the percentage of cells in G1 phase, but did not alter mRNA expression of cell cycle-related proteins prior to or following G2 phase. These results suggested that BDNF was not a risk factor for inducing apoptosis.展开更多
基金supported by the Guizhou Province High-level Innovative Talent Project(Qiankehe Platform Talent-GCC[2022]027-1)the National Key Research and Development Program of China(2019YFA0904800).
文摘Soft rot is a destructive disease that inflicts significant losses on agricultural production and the economy post-harvest.Biocontrol strategies based on antagonistic microorganisms have a broad application prospect to fight against plant pathogens.This study utilized fluorescence-activated droplet sorting(FADS)technology as an alternative to traditional plate culture methods to isolate microorganisms with antagonistic activity against the soft rot pathogen Erwinia carotovora Ecc15.Initially,the culture performance of the FADS platform was evaluated by analyzing bacterial diversity in droplet culture samples and agar plate culture samples,our data showed that droplet culture exhibited higher species richness and diversity than plate culture,and more than 95%of the operational taxonomic units(OTUs)in the droplet samples belonged to the rare biosphere.Additionally,we developed a green fluorescent protein(GFP)-Ecc15-based FADS screening system,which achieved an enrichment ratio of up to 148.Using this system,we successfully screened 32 antagonistic bacteria from rhizosphere soil sample of healthy konjac plants,and some may be novel microbial resources,including the genera Lelliottia,Buttiauxella and Leclercia.Notably,strain D-62 exhibited the strongest antibacterial ability against Ecc15,with an inhibition zone diameter of(20.86±1.56)mm.In vivo experiments conducted on the corms of Amorphophallus konjac demonstrated that strain D-62 could effectively reduce the infection ability of Ecc15 to the corms,indicating that strain D-62 has the potential to be developed as a biocontrol agent.Our findings suggested that the FADS screening system showed a screening efficiency approximately 3×10^(3)times higher than plate screening system,while significantly reducing costs of infrastructure,labor and consumables,it provides theoretical guidance for the screening of other plant pathogen biocontrol bacteria.
基金supported by National Institute of Dental and Craniofacial Research grant T90DE022734
文摘Mesenchymal stem cells （MSCs） are a promising tool in regenerative medicine due to their capacity to differentiate into multiple lineages. In addition to MSCs isolated from bone marrow （BMSCs）, adult MSCs are isolated from craniofacial tissues including dental pulp tissues （DPs） using various stem cell surface markers. However, there has been a lack of consensus on a set of surface makers that are reproducibly effective at isolating putative multipotent dental mesenchymal stem cel^s （~M^Cs）. II1 ~his stucly, we used clif^et（~nt combinations of surface markers （CD51/CD140a, CD271, and STRO-1/CD146） to isolate homogeneous populations of DMSCs from heterogeneous dental pulp cells （DPCs） obtained from DP and compared their capacity to undergo multilineage differentiation. Fluorescence-activated cell sorting revealed that 27.3% of DPCs were CD51＋/CD140a＋, 10.6% were CD271＋, and 0.3% were STRO-1＋/CD146＋. Under odontogenic conditions, all three subsets of isolated DMSCs exhibited differentiation capacity into odontogenic lineages. Among these isolated subsets of DMSCs, CD271＋ DMSCs demonstrated the greatest odontogenic potential. While all three combinations of surface markers in this study successfully isolated DMSCs from DPCs, the single CD271 marker presents the most effective stem cell surface marker for identification of DMSCs with high odontogenic potential. Isolated CD271＋ DMSCs could potentially be utilized for future clinical applications in dentistry and regenerative medicine.
文摘BACKGROUND： Previous studies have demonstrated that brain-derived neurotrophic factor （BDNF） promotes neural differentiation. However, the mechanisms involved in cell cycle-related protein regulation, which highly correlates to neural proliferation and apoptosis, remain poorly understood. OBJECTIVE： To investigate the effects of various concentrations of BDNF on cycle-related protein mRNA expression in induce-differentiated SH-SY5Y cells in vitro prior to and following G2 phase, and to analyze the neuroprotective effects of BDNF. DESIGN, TIME AND SETTING： A comparison, observational study, based on cell biology, was performed at the Department of Biochemistry, Medical College of Tongji University, from March 2005 to October 2006. MATERIALS： SH-SY5Y cells were provided by Shanghai Institute of Cytology, Chinese Academy of Science; BDNF by Alomone Labs, Israel; all-trans retinoic acid （ATRA） by Sigma-Aldrich, USA. METHODS： SH-SY5Y cells were randomly divided into three groups： blank control [cells were treated in Insulin-Transferrin-Selenium （ITS） solution for 7 days], ATRA （cells were treated with ITS solution containing 10 μmol/L ATRA for 7 days）, and BDNF （cells were treated identical to the ATRA group for 5 days, and then respectively treated in ITS solution containing 1, 10, and 100 μg/L BDNF for 2 days）. The experiment was repeated three times for each group. MAIN OUTCOME MEASURES： mRNA expression levels of cyclin A1, B1, B2, cyclin-dependent kinase 1, and 5 were detected using quantitative real-time RT-PCR; percentage of cells in G1, S, and G2 phases were detected using fluorescence-activated cell sorting. RESULTS： mRNA expression levels of cyclin A1 in the high-dose BDNF group was significantly less than the ATRA group （P 〈 0.05）.mRNA expression levels of cyclin B1 was significantly less in the different BDNF concentration groups compared with the control and ATRA groups （P 〈 0.05 or P 〈 0.01）. mRNA expression levels of cyclin B2 and cyclin-dependent kinase 1 were significantly decreased in the high-dose BDNF group （P 〈 0.05 or P 〈 0.01）. Cyclin-dependent kinase 5 mRNA expression was significantly greater in the low-dose and moderate-dose BDNF groups compared with the ATRA group （P 〈 0.05）. The percentage of cells in G1 phase was significantly greater in the different BDNF concentration groups compared with the ATRA and control groups （P 〈 0.01）. Moreover, the percentage of cells in S phase was significantly less in the three BDNF groups compared with the ATRA group （P 〈 0.01）. However, the percentage of cells in S phase was significantly less in the low-dose and high-dose BDNF groups compared with the control group （P 〈 0.01）. CONCLUSION： BDNF enhanced the percentage of cells in G1 phase, but did not alter mRNA expression of cell cycle-related proteins prior to or following G2 phase. These results suggested that BDNF was not a risk factor for inducing apoptosis.
