OsNRT1.1a is a low-affinity nitrate(NO_3^-) transporter gene. In this study, another mRNA splicing product, OsNRT1.1b,putatively encoding a protein with six transmembrane domains, was identified based on the rice ge...OsNRT1.1a is a low-affinity nitrate(NO_3^-) transporter gene. In this study, another mRNA splicing product, OsNRT1.1b,putatively encoding a protein with six transmembrane domains, was identified based on the rice genomic database and bioinformatics analysis. OsNRT1.1a/OsNRT1.1b expression in Xenopus oocytes showed OsNRT1.1a-expressing oocytes accumulated ^(15)N levels to about half as compared to OsNRT1.1bexpressing oocytes. The electrophysiological recording of OsNRT1.1b-expressing oocytes treated with 0.25 mM NO_3^- confirmed ^(15)N accumulation data. More functional assays were performed to examine the function of OsNRT1.1b in rice. The expression of both OsNRT1.1a and OsNRT1.1b was abundant in roots and downregulated by nitrogen(N) deficiency. The shoot biomass of transgenic rice plants with OsNRT1.1a or OsNRT1.1b overexpression increased under various N supplies under hydroponic conditions compared to wild-type(WT). The OsNRT1.1a overexpression lines showed increased plant N accumulation compared to the WT in 1.25 mM NH_4NO_3 and 2.5 mM NO_3^- or NH_4~+ treatments, but not in 0.125 mM NH_4NO_3.However, OsNRT1.1b overexpression lines increased total N accumulation in all N treatments, including 0.125 m M NH_4NO_3,suggesting that under low N condition, OsNRT1.1b would accumulate more N in plants and improve rice growth, but also that OsNRT1.1a had no such function in rice plants.展开更多
Inflammation plays an important role in the development of acute lung injury(ALI).Severe pulmonary inflammation can cause acute respiratory distress syndrome(ARDS)or even death.Expression of proinflammatory interleuki...Inflammation plays an important role in the development of acute lung injury(ALI).Severe pulmonary inflammation can cause acute respiratory distress syndrome(ARDS)or even death.Expression of proinflammatory interleukin-1β(IL-1β)and inducible nitric oxide synthase(iNOS)in the process of pulmonary inflammation will further exacerbate the severity of ALI.The purpose of this study was to explore the effect of Palrnatine(Pa)on lipopolysaccharide(LPS)-induced mouse ALI and its underlying mechanism.Pa,a natural product,has a wide range of pharmacological activities with the potential to protect against lung injury.Western blotting and quantitative real-time polymerase chain reaction(qRT-PCR)assays were performed to detect the expression and translation of inflammatory genes and proteins in vitro and in vivo.Immunoprecipitation was used to detect the degree of P65 translocation into the nucleus.We also used molecular modeling to further clarify the mechanism of action.The results showed that Pa pretreatment could significantly inhibit the expression and secretion of the inflammatory cytokine IL-1β,and significantly reduce the protein level of the proinflammatory protease iNOS,in both in vivo and in vitro models induced by LPS.Further mechanism studies showed that Pa could significantly inhibit the activation of the protein kinase B(Akt)/nuclear factor-κB(NF-κB)signaling pathway in the LPS-induced ALI mode and in LPS-induced RAW264.7 cells.Through molecular dynamics simulation,we observed that Pa was bound to the catalytic pocket of Akt and effectively inhibited the biological activity of Akt.These results indicated that Pa significantly relieves LPS-induced ALI by activating the Akt/NF-κB signaling pathway.展开更多
Based on the Weather Research and Forecasting model and the Models-3 community multi-scale air quality model(WRF-CMAQ),this study analyzes the impacts of meteorological conditions and changes in air pollutant emission...Based on the Weather Research and Forecasting model and the Models-3 community multi-scale air quality model(WRF-CMAQ),this study analyzes the impacts of meteorological conditions and changes in air pollutant emissions on the heavy air pollution episode occurred over North China around the 2020 Spring Festival(January to Februray 2020).Regional reductions in air pollutant emissions required to eliminate the PM2.5 heavy pollution episode are also quantified.Our results found that meteorological conditions for the Beijing-Tianjin-Hebei and surrounding"2+26"cities are the worst during the heavy pollution episode around the 2020 Spring Festival as compared with two other typical heavy pollution episodes that occurred after 2015.However,because of the substantial reductions in air pollutant emissions in the"2+26"cities in recent years,and the32%extra reduction in emissions during January to February 2020 compared with the baseline emission levels of the autumn and winter of 2019 to 2020,the maximum PM2.5 level during this heavy pollution episode around the 2020 Spring Festival was much lower than that in the other two typical episodes.Yet,these emission reductions are still not enough to eliminate regional heavy pollution episodes.Compared with the actual emission levels during January to February 2020,a 20%extra reduction in air pollutant emissions in the"2+26"cities(or a 45%extra reduction compared with baseline emission levels of the autumn and winter of 2019 to 2020)could help to generally eliminate regionwide severe pollution episodes,and avoid heavy pollution episodes that last three or more consecutive days in Beijing;a 40%extra reduction in emissions(or a 60%extra reduction compared with baseline emission levels of the autumn and winter of 2019 to 2020)could help to generally eliminate regionwide and continuous heavy pollution episodes.Our analysis finds that during the clean period after the heavy pollution episode around the 2020 Spring Festival,the regionwide heavy pollution episode would only occur with at least a 10-fold increase in air pollutant emissions.展开更多
基金supported by the National Natural Science Foundation of China (31172013, 31372122 and 31401938)
文摘OsNRT1.1a is a low-affinity nitrate(NO_3^-) transporter gene. In this study, another mRNA splicing product, OsNRT1.1b,putatively encoding a protein with six transmembrane domains, was identified based on the rice genomic database and bioinformatics analysis. OsNRT1.1a/OsNRT1.1b expression in Xenopus oocytes showed OsNRT1.1a-expressing oocytes accumulated ^(15)N levels to about half as compared to OsNRT1.1bexpressing oocytes. The electrophysiological recording of OsNRT1.1b-expressing oocytes treated with 0.25 mM NO_3^- confirmed ^(15)N accumulation data. More functional assays were performed to examine the function of OsNRT1.1b in rice. The expression of both OsNRT1.1a and OsNRT1.1b was abundant in roots and downregulated by nitrogen(N) deficiency. The shoot biomass of transgenic rice plants with OsNRT1.1a or OsNRT1.1b overexpression increased under various N supplies under hydroponic conditions compared to wild-type(WT). The OsNRT1.1a overexpression lines showed increased plant N accumulation compared to the WT in 1.25 mM NH_4NO_3 and 2.5 mM NO_3^- or NH_4~+ treatments, but not in 0.125 mM NH_4NO_3.However, OsNRT1.1b overexpression lines increased total N accumulation in all N treatments, including 0.125 m M NH_4NO_3,suggesting that under low N condition, OsNRT1.1b would accumulate more N in plants and improve rice growth, but also that OsNRT1.1a had no such function in rice plants.
基金the National Natural Science Foundation of China(Nos.31672509 and 31873004)the Jilin Scientific and Technological Development Program(Nos.20190103021JH and 20200201111JC)the Jilin University(JLU)Science and Technology Innovative Research Team(No.2017TD-30),China。
文摘Inflammation plays an important role in the development of acute lung injury(ALI).Severe pulmonary inflammation can cause acute respiratory distress syndrome(ARDS)or even death.Expression of proinflammatory interleukin-1β(IL-1β)and inducible nitric oxide synthase(iNOS)in the process of pulmonary inflammation will further exacerbate the severity of ALI.The purpose of this study was to explore the effect of Palrnatine(Pa)on lipopolysaccharide(LPS)-induced mouse ALI and its underlying mechanism.Pa,a natural product,has a wide range of pharmacological activities with the potential to protect against lung injury.Western blotting and quantitative real-time polymerase chain reaction(qRT-PCR)assays were performed to detect the expression and translation of inflammatory genes and proteins in vitro and in vivo.Immunoprecipitation was used to detect the degree of P65 translocation into the nucleus.We also used molecular modeling to further clarify the mechanism of action.The results showed that Pa pretreatment could significantly inhibit the expression and secretion of the inflammatory cytokine IL-1β,and significantly reduce the protein level of the proinflammatory protease iNOS,in both in vivo and in vitro models induced by LPS.Further mechanism studies showed that Pa could significantly inhibit the activation of the protein kinase B(Akt)/nuclear factor-κB(NF-κB)signaling pathway in the LPS-induced ALI mode and in LPS-induced RAW264.7 cells.Through molecular dynamics simulation,we observed that Pa was bound to the catalytic pocket of Akt and effectively inhibited the biological activity of Akt.These results indicated that Pa significantly relieves LPS-induced ALI by activating the Akt/NF-κB signaling pathway.
基金supported by the National Key Research and Development Program(Grant Nos.2016YFC0207502,2016YFC0208805)the National Research Program for Key Issues in Air Pollution Control(Grant No.DQGG0302)。
文摘Based on the Weather Research and Forecasting model and the Models-3 community multi-scale air quality model(WRF-CMAQ),this study analyzes the impacts of meteorological conditions and changes in air pollutant emissions on the heavy air pollution episode occurred over North China around the 2020 Spring Festival(January to Februray 2020).Regional reductions in air pollutant emissions required to eliminate the PM2.5 heavy pollution episode are also quantified.Our results found that meteorological conditions for the Beijing-Tianjin-Hebei and surrounding"2+26"cities are the worst during the heavy pollution episode around the 2020 Spring Festival as compared with two other typical heavy pollution episodes that occurred after 2015.However,because of the substantial reductions in air pollutant emissions in the"2+26"cities in recent years,and the32%extra reduction in emissions during January to February 2020 compared with the baseline emission levels of the autumn and winter of 2019 to 2020,the maximum PM2.5 level during this heavy pollution episode around the 2020 Spring Festival was much lower than that in the other two typical episodes.Yet,these emission reductions are still not enough to eliminate regional heavy pollution episodes.Compared with the actual emission levels during January to February 2020,a 20%extra reduction in air pollutant emissions in the"2+26"cities(or a 45%extra reduction compared with baseline emission levels of the autumn and winter of 2019 to 2020)could help to generally eliminate regionwide severe pollution episodes,and avoid heavy pollution episodes that last three or more consecutive days in Beijing;a 40%extra reduction in emissions(or a 60%extra reduction compared with baseline emission levels of the autumn and winter of 2019 to 2020)could help to generally eliminate regionwide and continuous heavy pollution episodes.Our analysis finds that during the clean period after the heavy pollution episode around the 2020 Spring Festival,the regionwide heavy pollution episode would only occur with at least a 10-fold increase in air pollutant emissions.