Sperm dysfunction is the single most common cause of infertility, yet what is remarkable is that, there is no drug a man can take or add to his spermatozoa in vitroto improve fertility. One reason for the lack of prog...Sperm dysfunction is the single most common cause of infertility, yet what is remarkable is that, there is no drug a man can take or add to his spermatozoa in vitroto improve fertility. One reason for the lack of progress in this area is that our understanding of the cellular and molecular workings of the mature spermatazoon is limited. However, over the last few years there has been considerable progress in our knowledge base and in addressing new methods to diagnose sperm dysfunction. We review the current state of the field and provide insights for further development. We conclude that: (i) there is little to be gained from more studies identifying/categorizing various populations of men using a basic semen assessment, where an effort is required in making sure the analysis is performed in an appropriate high quality way; (ii) technological development is likely to bring the reality of sperm function testing closer to implementation into the clinical pathways. In doing this, these assays must be robust, cheap (or more appropriately termed cost effective), easy to use and clinically useful; and (iii) clinical necessity, e.g., the need to identify the highest quality spermatozoon for injection is driving basic research forward. This is an exciting time to be an andrologist and, likely, a fruitful one.展开更多
Aremarkable advance in sperm physiology has recently been published in Nature. Two groups using patch damping techniques on human sperm have solved a mystery about the sperm cell that has puzzled both andrologists and...Aremarkable advance in sperm physiology has recently been published in Nature. Two groups using patch damping techniques on human sperm have solved a mystery about the sperm cell that has puzzled both andrologists and those involved in non-genomic cellular signalling for over 20 years. In these papers, Lishko1 and Strunker2 independently demonstrate that the universal characteristic effect of progesterone on sperm--a rapid influx of calcium--is via a sperm-specific channel CatSper.展开更多
Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO prod...Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO production and heme oxygenase (HO) activity, an important CO synthetic enzyme, are first reported to increase in response to ABA treatment, which could result in stomatal closure. Inter- estingly, ABA-induced stomatal closure in V. faba guard cells is partially blocked when the synthetic CO inhibitor ZnPP, or the CO/NO scavenger Hb is added. Furthermore, we show that, exogenously applied CO donor, hematin, and CO aqueous solution not only result in the enhancement of CO release, but also time-dependently induce stomatal closure, and the latter is mimicked by the application of an NO donor SNP. The above-mentioned stomatal closure effects are differentially reversed by the addition of tungstate, a potent inhibitor of NO synthetic enzyme nitrate reductase (NR), the specific NO scavenger cPTIO, ZnPP, or Hb. During treatment for 4 h, SNP, 0.01% CO aqueous solution or hematin significantly triggers NO synthesis, whereas cPTIO, or tungstate approximately fully inhibits NO fluorescence. Ad- ditionally, application of the GC inhibitor ODQ blocks CO-induced stomatal closure. This inhibition could be reversed when 8-Br-cGMP is added. Thus, the above results suggest that CO produced by HO is involved in ABA-induced stomatal closure, and NO and cGMP may function as downstream interme- diates in the CO signaling responsible for stomatal closure.展开更多
Recently In animals, endogenous carbon monoxide (CO), like nitric oxlde, was implicated as another Important physiological messenger or bioactive molecule. However, little information is known about the physlologlca...Recently In animals, endogenous carbon monoxide (CO), like nitric oxlde, was implicated as another Important physiological messenger or bioactive molecule. However, little information is known about the physlologlcal roles of CO in the whole plant. In the present study, we report that different concentrations of the 130 donor hematin (0.1, 1.0 and 10.0 μmol/L) alleviated wheat (Tilticum aestivum L. Yangmai 158) seed germination Inhlbltlon caused by 250 mmol/L NaCI stress In a dose-dependent manner. These responses were also proved by the addltion of different gaseous CO aqueous solutions from 0.1% to 100.0% of saturation. Among these treatments, the effect of 1.0 μmol/L hematin and 1.0% saturation of CO aqueous solution were the most obvlous. Furthermore, compared with non-hematin treatment, the degradation of storage reserves In wheat seeds was also accelerated. Time-course analyses showed that application of hematln dose-dependently Increased the activities of superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase activities, thus decreasing the lipid peroxidation In germinating wheat seed subjected to salt stress. Meanwhile, the responses of hematin were specific for CO because the addition of the CO scavenger hemoglobln (0.2 g/L) blocked the various actions of 1.0 μmol/L hematin. Taken together, the results of the present study demonstrate that CO, at a low concentration, is able to attenuate the seed germlnation Inhibition produced by salinity stress and counteract the lipid peroxidation in germinating wheat seeds.展开更多
Carbon monoxide (CO), an odorless, tasteless and colorless gas, has recently proved to be an important bioactive or signal molecule in mammalian cells, with its effects mediated mainly by nitric oxide (NO). In the...Carbon monoxide (CO), an odorless, tasteless and colorless gas, has recently proved to be an important bioactive or signal molecule in mammalian cells, with its effects mediated mainly by nitric oxide (NO). In the present report, we show that exogenous CO induces lateral root (LR) formation, an NO-dependent process. Administration of the CO donor hematin to rapeseed (Brassica napus L. Yangyou 6) seedlings for 3 days, dose-dependently promoted the total length and number of LRs. These responses were also seen following the application of gaseous CO aqueous solutions of different saturated concentrations. Furthermore, the actions of CO on seedlings were fully reversed when the CO scavenger hemoglobin (Hb) or the CO-specific synthetic inhibitor zinc protoporphyrin-IX(ZnPPIX) were added. Interestingly, depletion of endogenous NO using its specific scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO) or the nitric oxide synthase (NOS) inhibitor N^G-nitro-L-arginine methyl ester (L-NAME), led to the complete abolition of LR development, illustrating an important role for endogenous NO in the action of CO on LR formation. However, the induction of LR development by 200 μmol/L sodium nitroprusside (SNP), an NO donor, was not affected by the presence or absence of ZnPPIX. Furthermore, using an anatomical approach combined with laser scanning confocal microscopy with the NO-specific fluorophore 4,5-diaminofluorescein diacetate, we observed that both hematin and SNP increased NO release compared with control samples and that the NO signal was mainly distributed in the LR primordia (LRP), especially after 36 h treatment. The LRP were found to have similar morphology in control, SNP- and hematin-treated seedlings. Similarly, the enhancement of the NO signal by CO at 36 h was differentially quenched by the addition of cPTIO, L-NAME, ZnPPIX and Hb. In contrast, the induction of NO caused by SNP was not affected by the application of ZnPPIX. Therefore, we further deduced that CO induces LR formation probably mediated by the NO/NOS pathway and NO may act downstream of CO signaling, which has also been shown to occur in animals.展开更多
OBJECTIVE: To investigate the antioxidant activities as well as phytochemical constituents of Antidesma thwaitesianum Mull. Arg. leaf extracts. METHODS: The leaves of A. thwaitesianum were extracted using three diff...OBJECTIVE: To investigate the antioxidant activities as well as phytochemical constituents of Antidesma thwaitesianum Mull. Arg. leaf extracts. METHODS: The leaves of A. thwaitesianum were extracted using three different methods: blending with distilled water, maceration with ethanol and decoction. The chemical antioxidant activity of the plant leaf extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) radical and 2,2'-azinobis(3- ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS*) radical scavenging assays, as well as the ferric reducing antioxidant power assay. Cellular antioxidant activity was determined by superoxide and nitric oxide scavenging assays. The cytotoxicity of the leaf extracts in RAW 264.7 and differentiated HL-60 cells was tested in parallel using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays, respectively. The total phenolic and flavonoid contents were also assessed by spectrophotometric analysis Phytochemical constituents of the most potent extract were investigated by liquid chromatography with an electrospray ionization quadrupole time-of-flight mass spectrometer (LC-ESI-QTOF-MS/MS). RESULTS: The ethanolic (ME) and decoction (LW) extracts of dried leaves had the highest chemical scavenging activity against DPPH and ABTS+ free radicals with half maximal effective concentration (EC50) values ranging from 3.54 to 6.44 μg/mL. ME and LW exerted moderate ferric reducing activity, with ferric reducing antioxidant power values of 847.41 and 941.26 mg Fe2+/g extract, respectively. Similarly, ME showed potent cellular scavenging activity against superoxide and nitric oxide radicals with EC50 values of 58.12 and 71.90 μg/mL, respectively. However, LW exhibited only strong nitric oxide scavenging activity with an EC50 value of 91.20 μg/mL. The cell viability of RAW 264.7 and HL-60 cells was greater than 70% in all tested concentrations of both extracts, thus confirming the absence of their cytotoxicity. ME and LW contained high total phenolic contents of 231.14 and 274.42 mg gallic acid equivalents per gram, respectively, as well as high total flavonoid contents of 18.82 and 22.17 mg quercetin equivalents per gram, respectively. LC-ESI-QTOF- MS/MS analysis revealed the presence of 52 structurally characterized compounds in ME, 43 of whichwere tentatively identified. Hydroxycinnamic acids such as caffeic acid and its derivatives were the predominant phenolic compounds. CONCLUSION: This is the first report describing potent chemical and cellular antioxidant effects of the ethanolic leaf extract of A. thwaitesianum. The extract contained high total phenolic and flavonoid contents LC-ESI-QTOF-MS/MS analysis further revealed an abundance of caffeic acid derivatives and flavonoids. These data support its potential use as dietary supplements in oxidative stress prevention.展开更多
A bacterium strain Y3,capable of efficiently degrading pendimethalin,was isolated from activated sludge and identified as Bacillus subtilis according to its phenotypic features and 16 S rRNA phylogenetic analysis.This...A bacterium strain Y3,capable of efficiently degrading pendimethalin,was isolated from activated sludge and identified as Bacillus subtilis according to its phenotypic features and 16 S rRNA phylogenetic analysis.This strain could grow on pendimethalin as a sole carbon source and degrade 99.5%of 100 mg/L pendimethalin within 2.5 days in batch liquid culture,demonstrating a greater efficiency than any other reported strains.Three metabolic products,6-aminopendimethalin,5-amino-2-methyl-3-nitroso-4-(pentan-3-ylamino) benzoic acid,and 8-amino-2-ethyl-5-(hydroxymethyl)-1,2-dihydroquinoxaline-6-carboxylic acid,were identified by HPLC-MS/MS,and a new microbial degradation pathway was proposed.A nitroreductase catalyzing nitroreduction of pendimethalin to 6-aminopendimethalin was detected in the cell lysate of strain Y3.The cofactor was nicotinamide adenine dinucleotide phosphate(NADPH) or more preferably nicotinamide adenine dinucleotide(NADH).The optimal temperature and pH for the nitroreductase were 30℃ and 7.5,respectively.Hg^(2+),Ni^(2+),Pb^(2+),Co^(2+),Mn^(2+) Cu^(2+),Ag~+,and EDTA severely inhibited the nitroreductase activity,whereas Fe^(2+),Mg^(2+),and Ca^(2+) enhanced it.This study provides an efficient pendimethalin-degrading microorganism and broadens the knowledge of the microbial degradation pathway of pendimethalin.展开更多
文摘Sperm dysfunction is the single most common cause of infertility, yet what is remarkable is that, there is no drug a man can take or add to his spermatozoa in vitroto improve fertility. One reason for the lack of progress in this area is that our understanding of the cellular and molecular workings of the mature spermatazoon is limited. However, over the last few years there has been considerable progress in our knowledge base and in addressing new methods to diagnose sperm dysfunction. We review the current state of the field and provide insights for further development. We conclude that: (i) there is little to be gained from more studies identifying/categorizing various populations of men using a basic semen assessment, where an effort is required in making sure the analysis is performed in an appropriate high quality way; (ii) technological development is likely to bring the reality of sperm function testing closer to implementation into the clinical pathways. In doing this, these assays must be robust, cheap (or more appropriately termed cost effective), easy to use and clinically useful; and (iii) clinical necessity, e.g., the need to identify the highest quality spermatozoon for injection is driving basic research forward. This is an exciting time to be an andrologist and, likely, a fruitful one.
文摘Aremarkable advance in sperm physiology has recently been published in Nature. Two groups using patch damping techniques on human sperm have solved a mystery about the sperm cell that has puzzled both andrologists and those involved in non-genomic cellular signalling for over 20 years. In these papers, Lishko1 and Strunker2 independently demonstrate that the universal characteristic effect of progesterone on sperm--a rapid influx of calcium--is via a sperm-specific channel CatSper.
基金Supported by the National Natural Science Foundation of China (Grant No. 30671248)"Blue Project" of Jiangsu Province and the Student Research Train-ing (SRT) Project of Nanjing Agricultural University (Grant No. 0506A11)
文摘Carbon monoxide (CO) has recently proven to be an important bioactive or signaling molecule in mammalian cells. Its effects are mainly mediated by nitric oxide (NO) and cyclic GMP (cGMP). In Vicia faba leaves, CO production and heme oxygenase (HO) activity, an important CO synthetic enzyme, are first reported to increase in response to ABA treatment, which could result in stomatal closure. Inter- estingly, ABA-induced stomatal closure in V. faba guard cells is partially blocked when the synthetic CO inhibitor ZnPP, or the CO/NO scavenger Hb is added. Furthermore, we show that, exogenously applied CO donor, hematin, and CO aqueous solution not only result in the enhancement of CO release, but also time-dependently induce stomatal closure, and the latter is mimicked by the application of an NO donor SNP. The above-mentioned stomatal closure effects are differentially reversed by the addition of tungstate, a potent inhibitor of NO synthetic enzyme nitrate reductase (NR), the specific NO scavenger cPTIO, ZnPP, or Hb. During treatment for 4 h, SNP, 0.01% CO aqueous solution or hematin significantly triggers NO synthesis, whereas cPTIO, or tungstate approximately fully inhibits NO fluorescence. Ad- ditionally, application of the GC inhibitor ODQ blocks CO-induced stomatal closure. This inhibition could be reversed when 8-Br-cGMP is added. Thus, the above results suggest that CO produced by HO is involved in ABA-induced stomatal closure, and NO and cGMP may function as downstream interme- diates in the CO signaling responsible for stomatal closure.
基金Supported by the National Natural Science Foundation of China (3047104Y), the Grant to Innovative Young Scholars of Jiangsu Province in China (BK2004417), and by Student Research Training (SRT) Project (0506B03 end 0409B08) of Nanjing Agricultural University.
文摘Recently In animals, endogenous carbon monoxide (CO), like nitric oxlde, was implicated as another Important physiological messenger or bioactive molecule. However, little information is known about the physlologlcal roles of CO in the whole plant. In the present study, we report that different concentrations of the 130 donor hematin (0.1, 1.0 and 10.0 μmol/L) alleviated wheat (Tilticum aestivum L. Yangmai 158) seed germination Inhlbltlon caused by 250 mmol/L NaCI stress In a dose-dependent manner. These responses were also proved by the addltion of different gaseous CO aqueous solutions from 0.1% to 100.0% of saturation. Among these treatments, the effect of 1.0 μmol/L hematin and 1.0% saturation of CO aqueous solution were the most obvlous. Furthermore, compared with non-hematin treatment, the degradation of storage reserves In wheat seeds was also accelerated. Time-course analyses showed that application of hematln dose-dependently Increased the activities of superoxide dismutase, catalase, ascorbate peroxidase, and guaiacol peroxidase activities, thus decreasing the lipid peroxidation In germinating wheat seed subjected to salt stress. Meanwhile, the responses of hematin were specific for CO because the addition of the CO scavenger hemoglobln (0.2 g/L) blocked the various actions of 1.0 μmol/L hematin. Taken together, the results of the present study demonstrate that CO, at a low concentration, is able to attenuate the seed germlnation Inhibition produced by salinity stress and counteract the lipid peroxidation in germinating wheat seeds.
文摘Carbon monoxide (CO), an odorless, tasteless and colorless gas, has recently proved to be an important bioactive or signal molecule in mammalian cells, with its effects mediated mainly by nitric oxide (NO). In the present report, we show that exogenous CO induces lateral root (LR) formation, an NO-dependent process. Administration of the CO donor hematin to rapeseed (Brassica napus L. Yangyou 6) seedlings for 3 days, dose-dependently promoted the total length and number of LRs. These responses were also seen following the application of gaseous CO aqueous solutions of different saturated concentrations. Furthermore, the actions of CO on seedlings were fully reversed when the CO scavenger hemoglobin (Hb) or the CO-specific synthetic inhibitor zinc protoporphyrin-IX(ZnPPIX) were added. Interestingly, depletion of endogenous NO using its specific scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO) or the nitric oxide synthase (NOS) inhibitor N^G-nitro-L-arginine methyl ester (L-NAME), led to the complete abolition of LR development, illustrating an important role for endogenous NO in the action of CO on LR formation. However, the induction of LR development by 200 μmol/L sodium nitroprusside (SNP), an NO donor, was not affected by the presence or absence of ZnPPIX. Furthermore, using an anatomical approach combined with laser scanning confocal microscopy with the NO-specific fluorophore 4,5-diaminofluorescein diacetate, we observed that both hematin and SNP increased NO release compared with control samples and that the NO signal was mainly distributed in the LR primordia (LRP), especially after 36 h treatment. The LRP were found to have similar morphology in control, SNP- and hematin-treated seedlings. Similarly, the enhancement of the NO signal by CO at 36 h was differentially quenched by the addition of cPTIO, L-NAME, ZnPPIX and Hb. In contrast, the induction of NO caused by SNP was not affected by the application of ZnPPIX. Therefore, we further deduced that CO induces LR formation probably mediated by the NO/NOS pathway and NO may act downstream of CO signaling, which has also been shown to occur in animals.
基金supported by the National Research University Project of Thailand Office of Higher Education Commission,Faculty of Medicine,Thammasat University
文摘OBJECTIVE: To investigate the antioxidant activities as well as phytochemical constituents of Antidesma thwaitesianum Mull. Arg. leaf extracts. METHODS: The leaves of A. thwaitesianum were extracted using three different methods: blending with distilled water, maceration with ethanol and decoction. The chemical antioxidant activity of the plant leaf extracts was evaluated using 2,2-diphenyl-1-picryhydrazyl (DPPH) radical and 2,2'-azinobis(3- ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS*) radical scavenging assays, as well as the ferric reducing antioxidant power assay. Cellular antioxidant activity was determined by superoxide and nitric oxide scavenging assays. The cytotoxicity of the leaf extracts in RAW 264.7 and differentiated HL-60 cells was tested in parallel using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assays, respectively. The total phenolic and flavonoid contents were also assessed by spectrophotometric analysis Phytochemical constituents of the most potent extract were investigated by liquid chromatography with an electrospray ionization quadrupole time-of-flight mass spectrometer (LC-ESI-QTOF-MS/MS). RESULTS: The ethanolic (ME) and decoction (LW) extracts of dried leaves had the highest chemical scavenging activity against DPPH and ABTS+ free radicals with half maximal effective concentration (EC50) values ranging from 3.54 to 6.44 μg/mL. ME and LW exerted moderate ferric reducing activity, with ferric reducing antioxidant power values of 847.41 and 941.26 mg Fe2+/g extract, respectively. Similarly, ME showed potent cellular scavenging activity against superoxide and nitric oxide radicals with EC50 values of 58.12 and 71.90 μg/mL, respectively. However, LW exhibited only strong nitric oxide scavenging activity with an EC50 value of 91.20 μg/mL. The cell viability of RAW 264.7 and HL-60 cells was greater than 70% in all tested concentrations of both extracts, thus confirming the absence of their cytotoxicity. ME and LW contained high total phenolic contents of 231.14 and 274.42 mg gallic acid equivalents per gram, respectively, as well as high total flavonoid contents of 18.82 and 22.17 mg quercetin equivalents per gram, respectively. LC-ESI-QTOF- MS/MS analysis revealed the presence of 52 structurally characterized compounds in ME, 43 of whichwere tentatively identified. Hydroxycinnamic acids such as caffeic acid and its derivatives were the predominant phenolic compounds. CONCLUSION: This is the first report describing potent chemical and cellular antioxidant effects of the ethanolic leaf extract of A. thwaitesianum. The extract contained high total phenolic and flavonoid contents LC-ESI-QTOF-MS/MS analysis further revealed an abundance of caffeic acid derivatives and flavonoids. These data support its potential use as dietary supplements in oxidative stress prevention.
基金supported by the National Science and Technology Support Plan(No.2012BAD15B03)the China Postdoctoral Science Foundation(Nos.2014M561660 and 2013T60546)the Jiangsu Postdoctoral Science Foundation(No.1301114C)
文摘A bacterium strain Y3,capable of efficiently degrading pendimethalin,was isolated from activated sludge and identified as Bacillus subtilis according to its phenotypic features and 16 S rRNA phylogenetic analysis.This strain could grow on pendimethalin as a sole carbon source and degrade 99.5%of 100 mg/L pendimethalin within 2.5 days in batch liquid culture,demonstrating a greater efficiency than any other reported strains.Three metabolic products,6-aminopendimethalin,5-amino-2-methyl-3-nitroso-4-(pentan-3-ylamino) benzoic acid,and 8-amino-2-ethyl-5-(hydroxymethyl)-1,2-dihydroquinoxaline-6-carboxylic acid,were identified by HPLC-MS/MS,and a new microbial degradation pathway was proposed.A nitroreductase catalyzing nitroreduction of pendimethalin to 6-aminopendimethalin was detected in the cell lysate of strain Y3.The cofactor was nicotinamide adenine dinucleotide phosphate(NADPH) or more preferably nicotinamide adenine dinucleotide(NADH).The optimal temperature and pH for the nitroreductase were 30℃ and 7.5,respectively.Hg^(2+),Ni^(2+),Pb^(2+),Co^(2+),Mn^(2+) Cu^(2+),Ag~+,and EDTA severely inhibited the nitroreductase activity,whereas Fe^(2+),Mg^(2+),and Ca^(2+) enhanced it.This study provides an efficient pendimethalin-degrading microorganism and broadens the knowledge of the microbial degradation pathway of pendimethalin.