The mechanistic target of rapamycin(m TOR) is a serine/threonine kinase that plays a pivotal role in cellular growth, proliferation, survival, and metabolism. In the central nervous system(CNS), the mTOR pathway regul...The mechanistic target of rapamycin(m TOR) is a serine/threonine kinase that plays a pivotal role in cellular growth, proliferation, survival, and metabolism. In the central nervous system(CNS), the mTOR pathway regulates diverse aspects of neural development and function. Genetic mutations within the m TOR pathway lead to severe neurodevelopmental disorders, collectively known as “mTORopathies”(Crino, 2020). Dysfunctions of m TOR, including both its hyperactivation and hypoactivation, have also been implicated in a wide spectrum of other neurodevelopmental and neurodegenerative conditions, highlighting its importance in CNS health.展开更多
Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apopt...Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apoptosis in glaucoma.Modulation of Kir4.1 expression in Müller cells may therefore be a potential strategy for attenuating retinal ganglion cell damage in glaucoma.In this study,we identified seven predicted phosphorylation sites in Kir4.1 and constructed lentiviral expression systems expressing Kir4.1 mutated at each site to prevent phosphorylation.Following this,we treated Müller glial cells in vitro and in vivo with the m Glu R I agonist DHPG to induce Kir4.1 or Kir4.1 Tyr^(9)Asp overexpression.We found that both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited activation of Müller glial cells.Subsequently,we established a rat model of chronic ocular hypertension by injecting microbeads into the anterior chamber and overexpressed Kir4.1 or Kir4.1 Tyr^(9)Asp in the eye,and observed similar results in Müller cells in vivo as those seen in vitro.Both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited Müller cell activation,regulated the balance of Bax/Bcl-2,and reduced the m RNA and protein levels of pro-inflammatory factors,including interleukin-1βand tumor necrosis factor-α.Furthermore,we investigated the regulatory effects of Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression on the release of pro-inflammatory factors in a co-culture system of Müller glial cells and microglia.In this co-culture system,we observed elevated adenosine triphosphate concentrations in activated Müller cells,increased levels of translocator protein(a marker of microglial activation),and elevated interleukin-1βm RNA and protein levels in microglia induced by activated Müller cells.These changes could be reversed by Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression in Müller cells.Kir4.1 overexpression,but not Kir4.1 Tyr^(9)Asp overexpression,reduced the number of proliferative and migratory microglia induced by activated Müller cells.Collectively,these results suggest that the tyrosine residue at position nine in Kir4.1 may serve as a functional modulation site in the retina in an experimental model of glaucoma.Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression attenuated Müller cell activation,reduced ATP/P2X receptor–mediated interactions between glial cells,inhibited microglial activation,and decreased the synthesis and release of pro-inflammatory factors,consequently ameliorating retinal ganglion cell apoptosis in glaucoma.展开更多
Rising temperatures and increased droughts caused by climate change significantly reduce crop yields.Halophytes with different photosynthetic metabolism types have specific mechanisms for resistance to climatic factor...Rising temperatures and increased droughts caused by climate change significantly reduce crop yields.Halophytes with different photosynthetic metabolism types have specific mechanisms for resistance to climatic factors.This study analyzed the morphophysiological,biochemical,and molecular-genetic mechanisms of tolerance and adaptation in halophytes,promising candidates for the restoration of salt affected lands in arid and semi-arid areas.Experiments under drought(D)and elevated temperature(eT),as well as their combined action(eT+D),were performed on Atriplex verrucifera M.Bied.(C_(3)plant)and Climacoptera crassa(M.Bieb.)Botsch.(C_(4)-NAD-ME plant)with different types of photosynthesis.The activity of photosystem I(PSI)and the efficiency of photosystem II(PSII)were measured,along with the expression of genes involved in the light(psaA,psaB,psbA,CAB,Fd1,PGR5,and ndhH)and dark(rbcL,Ppc2,and PPDK)reactions of photosynthesis.The content of key carboxylating enzymes ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco)and phosphoenolpyruvate carboxylase(PEPC),as well as the photorespiration enzyme glycine decarboxylase(GDC),were assessed.Plant growth and water-salt balance parameters,and activity of enzymes in the malate dehydrogenase(MDH)system nicotinamide adenine dinucleotide(phosphate)(NAD(P))-MDH and NAD(P)-malic enzyme(ME)were also examined.A multivariate analysis of the experimental results revealed that A.verrucifera and C.crassa were both resistant to the effects of these climatic stressors.The tolerance mechanisms of both species were significantly influenced by a high level of photosynthetic plasticity.Nevertheless,differences were observed in the protective mechanisms underlying tolerance.In the C_(3)species,dissipative processes associated with non-photochemical quenching(NPQ)of PSII and MDH system enzymes(malate valves)were activated,particularly under osmotic stress.The negative effects in the C_(3)plants were caused by the combined action of eT+D,which was compensated by an increased expression of rbcL,psaA,CAB,and especially PGR5,i.e.,genes encoding Rubisco large subunit and PSI components:apoproteins A,chlorophyll a/b-associated protein(CAB)of light-harvesting complex,and proton gradient regulation 5(PGR5)protein of the main pathway of cyclic electron transport(CET)around PSI.In C_(4)species,the protective MDH complex was expressed to a lesser extent,but activation of the C_(4)carbon-concentrating mechanism(CCM)and upregulation of PGR5 expression were observed,particularly under the individual action of the factors.Under the combined stress of eT+D,C.crassa exhibited a synergistic effect,where the increase in NPQ level and NAD-ME activity,as well as decrease in NADP-ME activity was less pronounced compared with the effect of singular factors.Comparative physiological,biochemical,and molecular analyses of how C_(3)and C_(4)species response to individual and combined climatic factors provide new insights into sustainable plant adaptation strategies in the face of global climate change.Considering the high nutritional value of these two fodder species,a technological approach could be developed to improve the productivity of salt affected lands.展开更多
基金supported by grants from Simons Foundation (SFARI 479754),CIHR (PJT-180565)the Scottish Rite Charitable Foundation of Canada (to YL)funding from the Canada Research Chairs program。
文摘The mechanistic target of rapamycin(m TOR) is a serine/threonine kinase that plays a pivotal role in cellular growth, proliferation, survival, and metabolism. In the central nervous system(CNS), the mTOR pathway regulates diverse aspects of neural development and function. Genetic mutations within the m TOR pathway lead to severe neurodevelopmental disorders, collectively known as “mTORopathies”(Crino, 2020). Dysfunctions of m TOR, including both its hyperactivation and hypoactivation, have also been implicated in a wide spectrum of other neurodevelopmental and neurodegenerative conditions, highlighting its importance in CNS health.
基金supported by the National Natural Science Foundation of China,Nos.32271043(to ZW)and 82171047(to YM)the both Science and Technology Major Project of Shanghai,No.2018SHZDZX01 and ZJLabShanghai Center for Brain Science and Brain-Inspired Technology(to ZW)。
文摘Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apoptosis in glaucoma.Modulation of Kir4.1 expression in Müller cells may therefore be a potential strategy for attenuating retinal ganglion cell damage in glaucoma.In this study,we identified seven predicted phosphorylation sites in Kir4.1 and constructed lentiviral expression systems expressing Kir4.1 mutated at each site to prevent phosphorylation.Following this,we treated Müller glial cells in vitro and in vivo with the m Glu R I agonist DHPG to induce Kir4.1 or Kir4.1 Tyr^(9)Asp overexpression.We found that both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited activation of Müller glial cells.Subsequently,we established a rat model of chronic ocular hypertension by injecting microbeads into the anterior chamber and overexpressed Kir4.1 or Kir4.1 Tyr^(9)Asp in the eye,and observed similar results in Müller cells in vivo as those seen in vitro.Both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited Müller cell activation,regulated the balance of Bax/Bcl-2,and reduced the m RNA and protein levels of pro-inflammatory factors,including interleukin-1βand tumor necrosis factor-α.Furthermore,we investigated the regulatory effects of Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression on the release of pro-inflammatory factors in a co-culture system of Müller glial cells and microglia.In this co-culture system,we observed elevated adenosine triphosphate concentrations in activated Müller cells,increased levels of translocator protein(a marker of microglial activation),and elevated interleukin-1βm RNA and protein levels in microglia induced by activated Müller cells.These changes could be reversed by Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression in Müller cells.Kir4.1 overexpression,but not Kir4.1 Tyr^(9)Asp overexpression,reduced the number of proliferative and migratory microglia induced by activated Müller cells.Collectively,these results suggest that the tyrosine residue at position nine in Kir4.1 may serve as a functional modulation site in the retina in an experimental model of glaucoma.Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression attenuated Müller cell activation,reduced ATP/P2X receptor–mediated interactions between glial cells,inhibited microglial activation,and decreased the synthesis and release of pro-inflammatory factors,consequently ameliorating retinal ganglion cell apoptosis in glaucoma.
基金supported by the state assignment of Ministry of Science and Higher Education of the Russian Federation(122042700044-6)the Science and Technology Research Partnership for Sustainable Development(SATREPS)project(JPMJSA2001).
文摘Rising temperatures and increased droughts caused by climate change significantly reduce crop yields.Halophytes with different photosynthetic metabolism types have specific mechanisms for resistance to climatic factors.This study analyzed the morphophysiological,biochemical,and molecular-genetic mechanisms of tolerance and adaptation in halophytes,promising candidates for the restoration of salt affected lands in arid and semi-arid areas.Experiments under drought(D)and elevated temperature(eT),as well as their combined action(eT+D),were performed on Atriplex verrucifera M.Bied.(C_(3)plant)and Climacoptera crassa(M.Bieb.)Botsch.(C_(4)-NAD-ME plant)with different types of photosynthesis.The activity of photosystem I(PSI)and the efficiency of photosystem II(PSII)were measured,along with the expression of genes involved in the light(psaA,psaB,psbA,CAB,Fd1,PGR5,and ndhH)and dark(rbcL,Ppc2,and PPDK)reactions of photosynthesis.The content of key carboxylating enzymes ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco)and phosphoenolpyruvate carboxylase(PEPC),as well as the photorespiration enzyme glycine decarboxylase(GDC),were assessed.Plant growth and water-salt balance parameters,and activity of enzymes in the malate dehydrogenase(MDH)system nicotinamide adenine dinucleotide(phosphate)(NAD(P))-MDH and NAD(P)-malic enzyme(ME)were also examined.A multivariate analysis of the experimental results revealed that A.verrucifera and C.crassa were both resistant to the effects of these climatic stressors.The tolerance mechanisms of both species were significantly influenced by a high level of photosynthetic plasticity.Nevertheless,differences were observed in the protective mechanisms underlying tolerance.In the C_(3)species,dissipative processes associated with non-photochemical quenching(NPQ)of PSII and MDH system enzymes(malate valves)were activated,particularly under osmotic stress.The negative effects in the C_(3)plants were caused by the combined action of eT+D,which was compensated by an increased expression of rbcL,psaA,CAB,and especially PGR5,i.e.,genes encoding Rubisco large subunit and PSI components:apoproteins A,chlorophyll a/b-associated protein(CAB)of light-harvesting complex,and proton gradient regulation 5(PGR5)protein of the main pathway of cyclic electron transport(CET)around PSI.In C_(4)species,the protective MDH complex was expressed to a lesser extent,but activation of the C_(4)carbon-concentrating mechanism(CCM)and upregulation of PGR5 expression were observed,particularly under the individual action of the factors.Under the combined stress of eT+D,C.crassa exhibited a synergistic effect,where the increase in NPQ level and NAD-ME activity,as well as decrease in NADP-ME activity was less pronounced compared with the effect of singular factors.Comparative physiological,biochemical,and molecular analyses of how C_(3)and C_(4)species response to individual and combined climatic factors provide new insights into sustainable plant adaptation strategies in the face of global climate change.Considering the high nutritional value of these two fodder species,a technological approach could be developed to improve the productivity of salt affected lands.
