BACKGROUND Ferroptosis can induce low retention and engraftment after mesenchymal stem cell(MSC)delivery,which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension(PAH)ther...BACKGROUND Ferroptosis can induce low retention and engraftment after mesenchymal stem cell(MSC)delivery,which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension(PAH)therapy.Interestingly,the cystathionineγ-lyase(CSE)/hydrogen sulfide(H_(2)S)pathway may contribute to mediating ferroptosis.However,the influence of the CSE/H_(2)S pathway on ferroptosis in human umbilical cord MSCs(HUCMSCs)remains unclear.AIM To clarify whether the effect of HUCMSCs on vascular remodelling in PAH mice is affected by CSE/H_(2)S pathway-mediated ferroptosis,and to investigate the functions of the CSE/H_(2)S pathway in ferroptosis in HUCMSCs and the underlying mechanisms.METHODS Erastin and ferrostatin-1(Fer-1)were used to induce and inhibit ferroptosis,respectively.HUCMSCs were transfected with a vector to overexpress or inhibit expression of CSE.A PAH mouse model was established using 4-wk-old male BALB/c nude mice under hypoxic conditions,and pulmonary pressure and vascular remodelling were measured.The survival of HUCMSCs after delivery was observed by in vivo bioluminescence imaging.Cell viability,iron accumulation,reactive oxygen species production,cystine uptake,and lipid peroxidation in HUCMSCs were tested.Ferroptosis-related proteins and S-sulfhydrated Kelchlike ECH-associating protein 1(Keap1)were detected by western blot analysis.RESULTS In vivo,CSE overexpression improved cell survival after erastin-treated HUCMSC delivery in mice with hypoxiainduced PAH.In vitro,CSE overexpression improved H_(2)S production and ferroptosis-related indexes,such as cell viability,iron level,reactive oxygen species production,cystine uptake,lipid peroxidation,mitochondrial membrane density,and ferroptosis-related protein expression,in erastin-treated HUCMSCs.In contrast,in vivo,CSE inhibition decreased cell survival after Fer-1-treated HUCMSC delivery and aggravated vascular remodelling in PAH mice.In vitro,CSE inhibition decreased H_(2)S levels and restored ferroptosis in Fer-1-treated HUCMSCs.Interestingly,upregulation of the CSE/H_(2)S pathway induced Keap1 S-sulfhydration,which contributed to the inhibition of ferroptosis.CONCLUSION Regulation of the CSE/H_(2)S pathway in HUCMSCs contributes to the inhibition of ferroptosis and improves the suppressive effect on vascular remodelling in mice with hypoxia-induced PAH.Moreover,the protective effect of the CSE/H_(2)S pathway against ferroptosis in HUCMSCs is mediated via S-sulfhydrated Keap1/nuclear factor erythroid 2-related factor 2 signalling.The present study may provide a novel therapeutic avenue for improving the protective capacity of transplanted MSCs in PAH.展开更多
Hydrogen is a promising energy carrier that is expected to play a crucial role in helping Canada achieve its net-zero target by 2050.However,reducing the ambiguity in regulatory frameworks is essential to incentivize ...Hydrogen is a promising energy carrier that is expected to play a crucial role in helping Canada achieve its net-zero target by 2050.However,reducing the ambiguity in regulatory frameworks is essential to incentivize and facilitate international trade in hydrogen.To this end,regulators must agree on quantification methodologies that consider life cycle boundaries,process descriptions,co-product allocation,conversion constants,and certification units.Several studies have highlighted the importance of life cycle assessment(LCA)as a standardized,relevant method for estimating the carbon footprint associated with hydrogen production and evaluating its environmental sustainability.As such,LCAbased certification schemes could help create a transparent hydrogen market.The aim of this study is to validate the proposed harmonized LCA-based methodology for quantifying hydrogen production’s carbon intensity.This methodology follows a consistent scope and life cycle inventory(LCI)development criteria,alongside a rigorous data quality assessment.The well-to-gate carbon intensities of six hydrogen production pathways are compared,which range from 0.26 to 10.07 kg CO_(2)e per kg of hydrogen(kg CO_(2)e/kg H_(2)),against the hydrogen carbon intensity thresholds established by the Canadian Clean Hydrogen Investment Tax Credit(CHITC).For example,the biomass gasification with carbon capture(CC)pathway demonstrates the lowest carbon intensity,while thermochemical pathways,such as steam methane reforming of natural gas without CC,poses challenges to meeting the maximum CHTIC threshold of 4 kg CO_(2)e/kg H_(2).展开更多
Given the clean and inexhaustible solar energy from solar light,photocatalytic ammonia synthesis is extremely appealing.However,high electron-hole recombination rates and insufficient active sites severely limited N2 ...Given the clean and inexhaustible solar energy from solar light,photocatalytic ammonia synthesis is extremely appealing.However,high electron-hole recombination rates and insufficient active sites severely limited N2 photoreaction reduction.Herein,we designed and fabricated FeCu alloy nanoparticles anchored on carbon nitride nanosheets with excellent photocatalyt ic ammonia synthesis performance.As a coupler between Fe and carbon nitride,Cu promotes the separation of photogenerated charge carriers in carbon nitride under solar light irradiation,and renters the semiconductor a forceful electron donor for the Fe active sites.The accumulated electrons at Fe sites furtherly facilitated the adsorption and activation of the molecular nitrogen.Besides,the uniform dispersed FeCu alloy nanoparticles were on carbon nitride nanosheets enhanced the stability of photocataly tic nitrogen reduction reaction,making the artificial photocataly tic ammonia synthesis more sustainable for application.This work highlights that a direct electron transfer channel can be used to regulate the photochemical nitrogen fixation network.展开更多
As an efficient and sustainable alternative to traditional thermocatalytic hydrogenation in both petrochemical and fine chemical processes,electrochemical hydrogenation powered by renewable energy has attracted consid...As an efficient and sustainable alternative to traditional thermocatalytic hydrogenation in both petrochemical and fine chemical processes,electrochemical hydrogenation powered by renewable energy has attracted considerable attention[1].Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)offers an appealing route for CO_(2)resource utilization to produce high value-added chemicals or fuels.展开更多
Multiple enzymes involved in hydrogen metabolism have been detected in photosynthetic bacterium Rhodospirillum rubrum un-der various growth conditions.To investigate hydrogen metabolic pathways and the contribution of...Multiple enzymes involved in hydrogen metabolism have been detected in photosynthetic bacterium Rhodospirillum rubrum un-der various growth conditions.To investigate hydrogen metabolic pathways and the contribution of each pathway to hydrogen photoproduction in R.rubrum under the artificial illumination condition,three mutants were constructed,including nifHanfDG double mutant lacking both Fe-nitrogenase and Mo-nitrogenase,anfDG mutant lacking Fe-nitrogenase and nifHhupL double mu-tant(uptake hydrogenase deficient mutant).Comparison of the hydrogen production of these 3 mutants with R.rubrum wild type and the uptake hydrogenase deficient mutant showed that there was a third pathway involved in hydrogen production besides Mo-nitrogenase and Fe-nitrogenase,which mainly contributed to hydrogen evolution.Only a small portion of hydrogen was gen-erated by the third pathway.The hydrogen produced by Mo-nitrogenase,Fe-nitrogenase and the third pathway was about 93.5%,4.9%and 1.5%,respectively,while the hydrogen consumed by uptake hydrogenase was about 13.3%.The investigation of the formate-linked hydrogenase activity indicated that the third pathway for hydrogen production was not mediated by the for-mate-linked hydrogenase,but probably by some unknown enzyme.展开更多
基金the Natural Science Foundation of Shandong Province of China,No.ZR2021QH179 and ZR2020MH014.
文摘BACKGROUND Ferroptosis can induce low retention and engraftment after mesenchymal stem cell(MSC)delivery,which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension(PAH)therapy.Interestingly,the cystathionineγ-lyase(CSE)/hydrogen sulfide(H_(2)S)pathway may contribute to mediating ferroptosis.However,the influence of the CSE/H_(2)S pathway on ferroptosis in human umbilical cord MSCs(HUCMSCs)remains unclear.AIM To clarify whether the effect of HUCMSCs on vascular remodelling in PAH mice is affected by CSE/H_(2)S pathway-mediated ferroptosis,and to investigate the functions of the CSE/H_(2)S pathway in ferroptosis in HUCMSCs and the underlying mechanisms.METHODS Erastin and ferrostatin-1(Fer-1)were used to induce and inhibit ferroptosis,respectively.HUCMSCs were transfected with a vector to overexpress or inhibit expression of CSE.A PAH mouse model was established using 4-wk-old male BALB/c nude mice under hypoxic conditions,and pulmonary pressure and vascular remodelling were measured.The survival of HUCMSCs after delivery was observed by in vivo bioluminescence imaging.Cell viability,iron accumulation,reactive oxygen species production,cystine uptake,and lipid peroxidation in HUCMSCs were tested.Ferroptosis-related proteins and S-sulfhydrated Kelchlike ECH-associating protein 1(Keap1)were detected by western blot analysis.RESULTS In vivo,CSE overexpression improved cell survival after erastin-treated HUCMSC delivery in mice with hypoxiainduced PAH.In vitro,CSE overexpression improved H_(2)S production and ferroptosis-related indexes,such as cell viability,iron level,reactive oxygen species production,cystine uptake,lipid peroxidation,mitochondrial membrane density,and ferroptosis-related protein expression,in erastin-treated HUCMSCs.In contrast,in vivo,CSE inhibition decreased cell survival after Fer-1-treated HUCMSC delivery and aggravated vascular remodelling in PAH mice.In vitro,CSE inhibition decreased H_(2)S levels and restored ferroptosis in Fer-1-treated HUCMSCs.Interestingly,upregulation of the CSE/H_(2)S pathway induced Keap1 S-sulfhydration,which contributed to the inhibition of ferroptosis.CONCLUSION Regulation of the CSE/H_(2)S pathway in HUCMSCs contributes to the inhibition of ferroptosis and improves the suppressive effect on vascular remodelling in mice with hypoxia-induced PAH.Moreover,the protective effect of the CSE/H_(2)S pathway against ferroptosis in HUCMSCs is mediated via S-sulfhydrated Keap1/nuclear factor erythroid 2-related factor 2 signalling.The present study may provide a novel therapeutic avenue for improving the protective capacity of transplanted MSCs in PAH.
基金supported by the Office of Energy Research and Development(OERD)of Natural Resources Canada(project number NRC-22-315)the Advanced Clean Energy(ACE)program of the National Research Council of Canada.
文摘Hydrogen is a promising energy carrier that is expected to play a crucial role in helping Canada achieve its net-zero target by 2050.However,reducing the ambiguity in regulatory frameworks is essential to incentivize and facilitate international trade in hydrogen.To this end,regulators must agree on quantification methodologies that consider life cycle boundaries,process descriptions,co-product allocation,conversion constants,and certification units.Several studies have highlighted the importance of life cycle assessment(LCA)as a standardized,relevant method for estimating the carbon footprint associated with hydrogen production and evaluating its environmental sustainability.As such,LCAbased certification schemes could help create a transparent hydrogen market.The aim of this study is to validate the proposed harmonized LCA-based methodology for quantifying hydrogen production’s carbon intensity.This methodology follows a consistent scope and life cycle inventory(LCI)development criteria,alongside a rigorous data quality assessment.The well-to-gate carbon intensities of six hydrogen production pathways are compared,which range from 0.26 to 10.07 kg CO_(2)e per kg of hydrogen(kg CO_(2)e/kg H_(2)),against the hydrogen carbon intensity thresholds established by the Canadian Clean Hydrogen Investment Tax Credit(CHITC).For example,the biomass gasification with carbon capture(CC)pathway demonstrates the lowest carbon intensity,while thermochemical pathways,such as steam methane reforming of natural gas without CC,poses challenges to meeting the maximum CHTIC threshold of 4 kg CO_(2)e/kg H_(2).
基金financially supported by the National Natural Science Foundation of China(Nos.52002361 and 22109120)the Science and Technology Research Project of Jiangxi Provincial Education Department(Nos.GJJ2201045 and GJJ2201007)+2 种基金Zhejiang Provincial Natural Science Foundation of China(No.LQ21B030002)the Key Project for Science and Technology Cooperation of Jiangxi Province(No.20212BDH80005)the Project of the Science and Technology of Jingdezhen City(No.20202GYZD013-16)。
文摘Given the clean and inexhaustible solar energy from solar light,photocatalytic ammonia synthesis is extremely appealing.However,high electron-hole recombination rates and insufficient active sites severely limited N2 photoreaction reduction.Herein,we designed and fabricated FeCu alloy nanoparticles anchored on carbon nitride nanosheets with excellent photocatalyt ic ammonia synthesis performance.As a coupler between Fe and carbon nitride,Cu promotes the separation of photogenerated charge carriers in carbon nitride under solar light irradiation,and renters the semiconductor a forceful electron donor for the Fe active sites.The accumulated electrons at Fe sites furtherly facilitated the adsorption and activation of the molecular nitrogen.Besides,the uniform dispersed FeCu alloy nanoparticles were on carbon nitride nanosheets enhanced the stability of photocataly tic nitrogen reduction reaction,making the artificial photocataly tic ammonia synthesis more sustainable for application.This work highlights that a direct electron transfer channel can be used to regulate the photochemical nitrogen fixation network.
基金supported by the National Natural Science Foundation of China(No.92477134)Provincial Natural Science Foundation of Shandong(No.ZR2023ME014).
文摘As an efficient and sustainable alternative to traditional thermocatalytic hydrogenation in both petrochemical and fine chemical processes,electrochemical hydrogenation powered by renewable energy has attracted considerable attention[1].Electrocatalytic CO_(2)reduction reaction(CO_(2)RR)offers an appealing route for CO_(2)resource utilization to produce high value-added chemicals or fuels.
基金supported by the National High Technology Research and Development Program of China(Grant No 2006AA05z108)
文摘Multiple enzymes involved in hydrogen metabolism have been detected in photosynthetic bacterium Rhodospirillum rubrum un-der various growth conditions.To investigate hydrogen metabolic pathways and the contribution of each pathway to hydrogen photoproduction in R.rubrum under the artificial illumination condition,three mutants were constructed,including nifHanfDG double mutant lacking both Fe-nitrogenase and Mo-nitrogenase,anfDG mutant lacking Fe-nitrogenase and nifHhupL double mu-tant(uptake hydrogenase deficient mutant).Comparison of the hydrogen production of these 3 mutants with R.rubrum wild type and the uptake hydrogenase deficient mutant showed that there was a third pathway involved in hydrogen production besides Mo-nitrogenase and Fe-nitrogenase,which mainly contributed to hydrogen evolution.Only a small portion of hydrogen was gen-erated by the third pathway.The hydrogen produced by Mo-nitrogenase,Fe-nitrogenase and the third pathway was about 93.5%,4.9%and 1.5%,respectively,while the hydrogen consumed by uptake hydrogenase was about 13.3%.The investigation of the formate-linked hydrogenase activity indicated that the third pathway for hydrogen production was not mediated by the for-mate-linked hydrogenase,but probably by some unknown enzyme.
