Background: The most common subtype of chronic vulvar pain is provoked vestibulodynia. The entry of the vagina is the site of acute and recurrent pain in this highly prevalent and debilitating condition, which is char...Background: The most common subtype of chronic vulvar pain is provoked vestibulodynia. The entry of the vagina is the site of acute and recurrent pain in this highly prevalent and debilitating condition, which is characterized by pressure application or attempted vaginal penetration. The aim of this study was to determine the effectiveness of topical spermidine in patients with vestibulodynia. Methods: Topical gels containing spermidine in hyaluronate complexes Ubi1 and Ubi2 endowed with differentiated release ratio and viscosity were applied at 3 doses/week during 4-weeks, then at 2 doses/week during the next 4-weeks in two groups of patients. Pain relief was measured by visual analogic score (VAS) and dyspareunia score expressed as percent improvement from baseline to posttreatment. Results: Group 1 treated with Ubi1 provided improvement in pain (46%) and dyspareunia (27%). However, the treatment in Group 2 resulted in a superior amelioration: VAS of pain (76%) and dyspareunia (50%) as Ubi2 gel provided higher dose and viscosity along with improved local application. Conclusions: Our results demonstrated that preparation 2 resulted in greater reduction in symptoms as compared to preparation 1 as measured by the VAS and Marinoff scale. These early, yet outstanding clinical outcomes in vestibulodynia through to the stimulation of tissue mechanosensor and their relevant downstream effects are reviewed hereafter.展开更多
The peppers which were treated at ice-temperature for 6 hours and 1 mmol/L spermidine for 10 min, followed by cold storage (4℃ ± 1℃) respectively were investigated. The results indicated that the chilling injur...The peppers which were treated at ice-temperature for 6 hours and 1 mmol/L spermidine for 10 min, followed by cold storage (4℃ ± 1℃) respectively were investigated. The results indicated that the chilling injury was delayed and reduced by ice-temperature and spermidine treatments. Comparing with control group, ice-temperature and spermidine exerted significant effects on reduction of ascorbic acid (Vc) and chlororphyll contents, relatively high activity of superoxide dismutase (SOD), accumulation of malondialdehyde (MDA) as well as the increase of cell membrane penetrability. The results indicated that the spermidine and ice-temperature induced the activity of antioxidant enzyme SOD and maintained higher defence-related compound Vc as well as lower levels of membrane lipid peroxidation, which may be associated with chilling injury alleviation. There was a difference between ice-temperature treatment and spermidine treatment after 30 days. The results suggested that spermidine was more effective in reducing chilling sensitivity and prolonging storage of peppers.展开更多
In order to study how exogenous hormones in C.lanceolata(gymnosperm)regulate somatic embryogenesis,we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found th...In order to study how exogenous hormones in C.lanceolata(gymnosperm)regulate somatic embryogenesis,we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found that an increase in endogenous concentrations of IAA and ABA may be correlated to more efficient somatic embryogenesis.By applying exogenous spermidine,we found that exogenous hormones may affect somatic embryogenesis efficiency through affecting the endogenous phytohormone content.Based on these results,further studies can be conducted whereby the concentration of exogenous hormones or the levels of endogenous phytohormones by molecular methods are regulated to promote somatic embryogenesis.Our research may benefit the long-term economic output of the forestry industry and lays the foundation to studying the molecular mechanism that controls somatic embryogenesis efficiency.展开更多
A monoclonal antibody was first prepared by fusion of mouse myeloma cells (SP2/0-Ag-14) with spleen cells isolated from male BALB/ c mice immunized with spermidine-bovine serum albumin conjugate (SPD- BSA). The hybrid...A monoclonal antibody was first prepared by fusion of mouse myeloma cells (SP2/0-Ag-14) with spleen cells isolated from male BALB/ c mice immunized with spermidine-bovine serum albumin conjugate (SPD- BSA). The hybridoma cell line producing antibody specific for spermidine was cultured in vitro and after i. p. into mice, the ascitic fluid gave suitably high dilution titres (1: 106) by enzyme immunoassay. This monoclonal antibody is of IgG1 class and the bimolecular compleex with molecular weight of 52KD and 27 KD. The monoclonal antibody was clearly specific to spermidine comparing with spermine or putriscine. Monclonal antibody may prove to be useful in the rapid diagnosis and evaluation of patients with cancer.展开更多
AIM:To test the growth-promoting activity of the polyamine spermidine bound to various polymeric compounds in supramolecular complexes.METHODS:A thiazolyl blue cell viability assay was used to determine the growth-pro...AIM:To test the growth-promoting activity of the polyamine spermidine bound to various polymeric compounds in supramolecular complexes.METHODS:A thiazolyl blue cell viability assay was used to determine the growth-promoting potency of spermidine-supramolecular complexes in a human skin fibroblast cell line exposed to spermidine and different spermidine-supramolecular complexes that were obtained by combining spermidine and polyanionic polymers or cyclodextrin.Reconstituted human vaginal epithelium was exposed to a specific spermidinesupramolecular complex,i.e.,spermidine-hyaluronan(HA)50,and cell proliferation was determined by Ki-67immunohistochemical detection.Transepithelial electrical resistance and histological analysis were also performed on reconstituted human vaginal epithelium to assess tissue integrity.RESULTS:The effect of spermidine and spermidinesupramolecular complexes was first tested in skin fi-broblasts.Spermidine displayed a reverse dose-related mode of activity with mmol/L growth inhibition,whereas 30%stimulation over basal levels was detected at mol/L and nmol/L levels.Novel spermidine-supramolecular complexes that formed between spermidine and polyanionic polymers,such as HA,alginate,and polymaleate,were then tested at variable spermidine concentrations and a fixed polymer level(0.1%w/v).Spermidine-supramolecular complexes stimulated the cell growth rate throughout the entire concentration range with maximal potency(up to 80%)at sub-mol/L levels.Similar results were obtained with spermidine-(-cyclodextrin),another type of spermidine-supramolecular complex.Moreover,the increased expression of Ki-67 in the reconstituted human vaginal epithelium exposed to spermidine-HA 50 showed that the mode of action behind the spermidine-supramolecular complexes was increased cell proliferation.Functional and morphological assessments of reconstituted human vaginal epithelium integrity did not show significant alterations after exposure to spermidine-HA,thus supporting its safety.CONCLUSION:Spermidine found in spermidine-supramolecular complexes displayed potentiated regenerative effects.Safety data on reconstituted human vaginal epithelium suggested that assessing spermidinesupramolecular complex efficacy in atrophic disorders is justified.展开更多
Exogenous application of spermidine(Spd) has been reported to modulate physiological processes and alleviate salt-induced damage to growth and productivity of several plants including rice. Employing a proteomic appro...Exogenous application of spermidine(Spd) has been reported to modulate physiological processes and alleviate salt-induced damage to growth and productivity of several plants including rice. Employing a proteomic approach, we aimed at identifying rice leaf and grain proteins differentially expressing under salt stress, and in response to Spd prior to Na Cl treatment. A total of 9 and 20 differentially expressed protein spots were identified in the leaves of salt-tolerant(Pokkali) and saltsensitive(KDML105) rice cultivars, respectively. Differential proteins common to both cultivars included a photosynthetic light reaction protein(oxygen-evolving complex protein 1), enzymes of Calvin cycle and glycolysis(fructose-bisphosphate aldolase and triose-phosphate isomerase), malate dehydrogenase, superoxide dismutase and a hypothetical protein(Os I_18213). Most proteins were present at higher intensities in Pokkali leaves. The photosynthetic oxygen-evolving enhancer protein 2 was detected only in Pokkali and was up-regulated by salt-stress and further enhanced by Spd treatment. All three spots identified as superoxide dismutase in KDML105 were up-regulated by Na Cl but down-regulated when treated with Spd prior to Na Cl, indicating that Spd acted directly as antioxidants. Important differential stress proteins detected in mature grains of both rice cultivars were late embryogenesis abundant proteins with protective roles and an antioxidant protein, 1-Cys-peroxiredoxin. Higher salt tolerance of Pokkali partly resulted from higher intensities and more responsiveness of the proteins relating to photosynthesis light reactions, energy metabolism, antioxidant enzymes in the leaves, and stress proteins with protective roles in the grains.展开更多
Two wheat cultivars(Triticum aestivum L.) were used to evaluate the effects of post-anthesis severe water deficit(SD) on starch content and granule size distribution and their relations with ethylene and spermidine(Sp...Two wheat cultivars(Triticum aestivum L.) were used to evaluate the effects of post-anthesis severe water deficit(SD) on starch content and granule size distribution and their relations with ethylene and spermidine(Spd). Comparison to the well-watered(WW) treatment, SD led to lower Spd and higher 1-aminocylopropane-1-carboxylic acid(ACC) concentrations and ethylene evolution rate(EER) in grains at the critical stage of forming starch granules. Application of Spd or aminoethoxyvinylglycine(AVG) significantly reduced ACC concentration and EER and increased Spd concentration, while ethephon or methylglyoxal-bis(MGBG) had an opposite impact. The volume and surface area distribution of starch granules showed a bimodal curve, while the number distribution exhibited a unimodal curve. SD caused a marked drop in grain weight, grain number and starch content, also led to a significant reduction in the proportion(both by volume and by surface area) of B-type starch granules(<10 μm), with an increase in those of A-type starch granules(>10 μm). Application of Spd or AVG increased the proportion(both by volume and by surface area) of B- type starch granules under SD. Correlation analysis suggested that ethylene and Spd showed an antagonism relation in the f ormation of B-type granules. These results suggested that it would be good for the formation of B-type starch granules to have the physiological traits of higher Spd and lower ACC concentrations and ethylene emission under SD.展开更多
In vitro investigation on the condensation of DNA induced by naturally occurring polyamines can provide useful insights into the packaging state of DNA in vivo , which is closely related to the mechanism of the self r...In vitro investigation on the condensation of DNA induced by naturally occurring polyamines can provide useful insights into the packaging state of DNA in vivo , which is closely related to the mechanism of the self regulation or self switching of the gene expression. The present paper reports the high resolution AFM observations of the condensates of spermidine DNA complexes. It was found that the spermidine can directly condense the DNA into toroidal structures. The formation of this special structure is greatly influenced by the dynamic factors such as the concentrations and the reaction time. Close examination revealed that the toroids were constructed by many particles stacked and squeezed together. Our observations indicate that the dynamic process of the toroid formation may be a spiral wound process of the globular subunits.展开更多
Idiopathic pulmonary fibrosis(IPF) is a progressive, fatal lung disease with poor survival. The advances made in deciphering IPF have led to the approval of different anti-fibrotic molecules, such as pirfenidone and n...Idiopathic pulmonary fibrosis(IPF) is a progressive, fatal lung disease with poor survival. The advances made in deciphering IPF have led to the approval of different anti-fibrotic molecules, such as pirfenidone and nintedanib. An increasing number of studies with particles(liposomes, nanoparticles, microspheres, nanopolymersomes and nanoliposomes) modified with different functional groups have demonstrated improvement in lung targeted drug delivery. In the present study, we prepared, characterized, and evaluated spermidine(SPD) modified poly-lactic-co-glycolide nanoparticles(SPD-AKF-PLGA/NPs) as carriers for fluorofenidone(AKF) in order to improve the anti-fibrotic efficacy of this drug in lung. SPD-AKF-PLGA/NPs were prepared and functionalized by modified solvent evaporation method with spermidine(SPD), poly-lactic-co-glycolide-polyethylene glycol(PEG-PLGA) groups. The size of SPD-AKF-PLGA/NPs was 172.5±4.3 nm. The AKF release from nanoparticles was shown to be fit Higuchi model. The A549 cellular uptake of the SPD-Cou-6-NPs group was found to be almost 2-fold higher than that of the Cou-6-NPs group. Free SPD and DFMO were pre-incubated in A549 cells to further prove that the uptake of SPD-Cou-6-PLGA/NPs via PTS. As a result, the uptake of SPD-Cou-6-PLGA/NPs significantly decreased with the increase of SPD concentrations in incubation. At the higher SPD concentrations in 50 and 500 μM, the uptake of SPD-Cou-6-PLGA/NPs reduced 0.34 and 0.49-fold than that without SPD pretreatment. After pretreatment with DFMO for 36 h, the cellular uptake of SPD-Cou-6-NPs reached 1.26-fold compared to untreated DFMO group. In biodistribution study, the drug targeting index of SPD-AKF-PLGA/NPs in lung was 3.62 and 4.66-fold than that of AKF-PLGA/NPs and AKF solution, respectively. It was suggested that the SPD-AKF-PLGA/NPs could accumulate effectively in the lung. The lung histopathology changes and collagen deposition were observed by HE staining and Masson staining in efficacy study. In SPD-AKF-PLGA/NPs group, the damage was further improved compared to that of the AKFPLGA/NPs group and AKF solution group. The results indicated that SPD-AKF-PLGA/NPs could be effective nanocarriers for antipulmonary fibrosis therapy.展开更多
The effects of foliar spraying with spermidine (Spd), ranging in concentration from 0.25 to 0.50mmol/L, on the antioxidant system under Cd2+ stress (range 0.1- 0.2 mmol/L Cd2+) in Typha latifolia L.grown hydroponicall...The effects of foliar spraying with spermidine (Spd), ranging in concentration from 0.25 to 0.50mmol/L, on the antioxidant system under Cd2+ stress (range 0.1- 0.2 mmol/L Cd2+) in Typha latifolia L.grown hydroponically were investigated in order to offer a referenced evidence for an understanding of the mechanism by which polyamines (PAs) relieve the damage to plants by heavy metal and improve the phytoremediation efficiency of heavy metal-contaminated water. The results showed that Cd2+ stress inhydrogen peroxide (H2O2) and malondialdehyde (MDA) contents in both leaves and caudices. With theexception of superoxide dismutase (SOD) activity in the leaves, an increase in the activities of catalase (CAT), guaiacol peroxidase (GPX), and glutathione reductase (GR) was observed in both leaves and caudices,SOD activity was increased in caudices, and ascorbate peroxidase (APX) activity was increased in leaves following Cd2+ treatment. The reduced glutathione (GSH) content in both leaves and caudices and the reductive ascorbate content in leaves was obviously increased, which were prompted by the application of exogenous Spd. Spraying with Spd increased the activity of GR and APX in both leaves and caudices,whereas the activity of SOD, CAT, and GPX was increased only in caudices following spraying with Spd.with Spd. The decrease in MDA was more obvious following the application of 0.25 than 0.50 mmol/L Spd.It is supposed that exogenous Spd elevated the tolerance of T. latifolia under Cd2+ stress primarily by increasing GR activity and the GSH level.展开更多
With atomic force microscopy (AFM) we systematically studied the DNA condensations on mica surfaces induced by multivalent cation spermidine. The pattern of the DNA condensates is a flat single layer, with a core in t...With atomic force microscopy (AFM) we systematically studied the DNA condensations on mica surfaces induced by multivalent cation spermidine. The pattern of the DNA condensates is a flat single layer, with a core in the centre and DNA wrapping around it at high density. We assume this to be a two-dimensional condensation of free coiled DNA onto negatively charged mica surfaces by the multivalent cation. The DNA molecules condense on mica surfaces via a pathway different from the formation of toroids, rods or globules in bulk solutions. We give an explanation to why toroid structures are difficult to be observed by AFM, and further discuss the relationship between DNA condensations in solutions and on mica surfaces. The present work will be helpful for understanding the behaviors of DNA on charged surfaces, which might be significantly different from that in solutions.展开更多
文摘Background: The most common subtype of chronic vulvar pain is provoked vestibulodynia. The entry of the vagina is the site of acute and recurrent pain in this highly prevalent and debilitating condition, which is characterized by pressure application or attempted vaginal penetration. The aim of this study was to determine the effectiveness of topical spermidine in patients with vestibulodynia. Methods: Topical gels containing spermidine in hyaluronate complexes Ubi1 and Ubi2 endowed with differentiated release ratio and viscosity were applied at 3 doses/week during 4-weeks, then at 2 doses/week during the next 4-weeks in two groups of patients. Pain relief was measured by visual analogic score (VAS) and dyspareunia score expressed as percent improvement from baseline to posttreatment. Results: Group 1 treated with Ubi1 provided improvement in pain (46%) and dyspareunia (27%). However, the treatment in Group 2 resulted in a superior amelioration: VAS of pain (76%) and dyspareunia (50%) as Ubi2 gel provided higher dose and viscosity along with improved local application. Conclusions: Our results demonstrated that preparation 2 resulted in greater reduction in symptoms as compared to preparation 1 as measured by the VAS and Marinoff scale. These early, yet outstanding clinical outcomes in vestibulodynia through to the stimulation of tissue mechanosensor and their relevant downstream effects are reviewed hereafter.
文摘The peppers which were treated at ice-temperature for 6 hours and 1 mmol/L spermidine for 10 min, followed by cold storage (4℃ ± 1℃) respectively were investigated. The results indicated that the chilling injury was delayed and reduced by ice-temperature and spermidine treatments. Comparing with control group, ice-temperature and spermidine exerted significant effects on reduction of ascorbic acid (Vc) and chlororphyll contents, relatively high activity of superoxide dismutase (SOD), accumulation of malondialdehyde (MDA) as well as the increase of cell membrane penetrability. The results indicated that the spermidine and ice-temperature induced the activity of antioxidant enzyme SOD and maintained higher defence-related compound Vc as well as lower levels of membrane lipid peroxidation, which may be associated with chilling injury alleviation. There was a difference between ice-temperature treatment and spermidine treatment after 30 days. The results suggested that spermidine was more effective in reducing chilling sensitivity and prolonging storage of peppers.
基金This research was supported by Foundation of Jiangsu forestry bureau(LYKJ[2017]42)Key research and development plan of Jiangsu Province(BE2017376)+2 种基金the Nature Science Foundation of China(31770715)the Qinglan project of Jiangsu province,Priority Academic Program Development of Jiangsu Higher Education Institutions,Natural Science Foundation of Jiangsu Province(BK20181176)the Joint Fund of the Natural Science Foundation of China and the Karst Science Research Center of Guizhou Province(Grant No.U1812401).
文摘In order to study how exogenous hormones in C.lanceolata(gymnosperm)regulate somatic embryogenesis,we measured the endogenous phytohormones of two genotypes with different somatic embryogenesis efficiency and found that an increase in endogenous concentrations of IAA and ABA may be correlated to more efficient somatic embryogenesis.By applying exogenous spermidine,we found that exogenous hormones may affect somatic embryogenesis efficiency through affecting the endogenous phytohormone content.Based on these results,further studies can be conducted whereby the concentration of exogenous hormones or the levels of endogenous phytohormones by molecular methods are regulated to promote somatic embryogenesis.Our research may benefit the long-term economic output of the forestry industry and lays the foundation to studying the molecular mechanism that controls somatic embryogenesis efficiency.
文摘A monoclonal antibody was first prepared by fusion of mouse myeloma cells (SP2/0-Ag-14) with spleen cells isolated from male BALB/ c mice immunized with spermidine-bovine serum albumin conjugate (SPD- BSA). The hybridoma cell line producing antibody specific for spermidine was cultured in vitro and after i. p. into mice, the ascitic fluid gave suitably high dilution titres (1: 106) by enzyme immunoassay. This monoclonal antibody is of IgG1 class and the bimolecular compleex with molecular weight of 52KD and 27 KD. The monoclonal antibody was clearly specific to spermidine comparing with spermine or putriscine. Monclonal antibody may prove to be useful in the rapid diagnosis and evaluation of patients with cancer.
基金Supported by Grants from the Italian Ministry of Education
文摘AIM:To test the growth-promoting activity of the polyamine spermidine bound to various polymeric compounds in supramolecular complexes.METHODS:A thiazolyl blue cell viability assay was used to determine the growth-promoting potency of spermidine-supramolecular complexes in a human skin fibroblast cell line exposed to spermidine and different spermidine-supramolecular complexes that were obtained by combining spermidine and polyanionic polymers or cyclodextrin.Reconstituted human vaginal epithelium was exposed to a specific spermidinesupramolecular complex,i.e.,spermidine-hyaluronan(HA)50,and cell proliferation was determined by Ki-67immunohistochemical detection.Transepithelial electrical resistance and histological analysis were also performed on reconstituted human vaginal epithelium to assess tissue integrity.RESULTS:The effect of spermidine and spermidinesupramolecular complexes was first tested in skin fi-broblasts.Spermidine displayed a reverse dose-related mode of activity with mmol/L growth inhibition,whereas 30%stimulation over basal levels was detected at mol/L and nmol/L levels.Novel spermidine-supramolecular complexes that formed between spermidine and polyanionic polymers,such as HA,alginate,and polymaleate,were then tested at variable spermidine concentrations and a fixed polymer level(0.1%w/v).Spermidine-supramolecular complexes stimulated the cell growth rate throughout the entire concentration range with maximal potency(up to 80%)at sub-mol/L levels.Similar results were obtained with spermidine-(-cyclodextrin),another type of spermidine-supramolecular complex.Moreover,the increased expression of Ki-67 in the reconstituted human vaginal epithelium exposed to spermidine-HA 50 showed that the mode of action behind the spermidine-supramolecular complexes was increased cell proliferation.Functional and morphological assessments of reconstituted human vaginal epithelium integrity did not show significant alterations after exposure to spermidine-HA,thus supporting its safety.CONCLUSION:Spermidine found in spermidine-supramolecular complexes displayed potentiated regenerative effects.Safety data on reconstituted human vaginal epithelium suggested that assessing spermidinesupramolecular complex efficacy in atrophic disorders is justified.
基金financially supported by Khon Kaen University Research Fund awarded to Salt-Tolerant Rice Research Group
文摘Exogenous application of spermidine(Spd) has been reported to modulate physiological processes and alleviate salt-induced damage to growth and productivity of several plants including rice. Employing a proteomic approach, we aimed at identifying rice leaf and grain proteins differentially expressing under salt stress, and in response to Spd prior to Na Cl treatment. A total of 9 and 20 differentially expressed protein spots were identified in the leaves of salt-tolerant(Pokkali) and saltsensitive(KDML105) rice cultivars, respectively. Differential proteins common to both cultivars included a photosynthetic light reaction protein(oxygen-evolving complex protein 1), enzymes of Calvin cycle and glycolysis(fructose-bisphosphate aldolase and triose-phosphate isomerase), malate dehydrogenase, superoxide dismutase and a hypothetical protein(Os I_18213). Most proteins were present at higher intensities in Pokkali leaves. The photosynthetic oxygen-evolving enhancer protein 2 was detected only in Pokkali and was up-regulated by salt-stress and further enhanced by Spd treatment. All three spots identified as superoxide dismutase in KDML105 were up-regulated by Na Cl but down-regulated when treated with Spd prior to Na Cl, indicating that Spd acted directly as antioxidants. Important differential stress proteins detected in mature grains of both rice cultivars were late embryogenesis abundant proteins with protective roles and an antioxidant protein, 1-Cys-peroxiredoxin. Higher salt tolerance of Pokkali partly resulted from higher intensities and more responsiveness of the proteins relating to photosynthesis light reactions, energy metabolism, antioxidant enzymes in the leaves, and stress proteins with protective roles in the grains.
基金the National Natural Science Foundation of China(31271661,30871477)the National Basic Research Program of China(2009CB118602)+1 种基金the Special Fund for Agro-Scientific Research in the Public Interest of China(201203100)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2012BAD04B05)
文摘Two wheat cultivars(Triticum aestivum L.) were used to evaluate the effects of post-anthesis severe water deficit(SD) on starch content and granule size distribution and their relations with ethylene and spermidine(Spd). Comparison to the well-watered(WW) treatment, SD led to lower Spd and higher 1-aminocylopropane-1-carboxylic acid(ACC) concentrations and ethylene evolution rate(EER) in grains at the critical stage of forming starch granules. Application of Spd or aminoethoxyvinylglycine(AVG) significantly reduced ACC concentration and EER and increased Spd concentration, while ethephon or methylglyoxal-bis(MGBG) had an opposite impact. The volume and surface area distribution of starch granules showed a bimodal curve, while the number distribution exhibited a unimodal curve. SD caused a marked drop in grain weight, grain number and starch content, also led to a significant reduction in the proportion(both by volume and by surface area) of B-type starch granules(<10 μm), with an increase in those of A-type starch granules(>10 μm). Application of Spd or AVG increased the proportion(both by volume and by surface area) of B- type starch granules under SD. Correlation analysis suggested that ethylene and Spd showed an antagonism relation in the f ormation of B-type granules. These results suggested that it would be good for the formation of B-type starch granules to have the physiological traits of higher Spd and lower ACC concentrations and ethylene emission under SD.
文摘In vitro investigation on the condensation of DNA induced by naturally occurring polyamines can provide useful insights into the packaging state of DNA in vivo , which is closely related to the mechanism of the self regulation or self switching of the gene expression. The present paper reports the high resolution AFM observations of the condensates of spermidine DNA complexes. It was found that the spermidine can directly condense the DNA into toroidal structures. The formation of this special structure is greatly influenced by the dynamic factors such as the concentrations and the reaction time. Close examination revealed that the toroids were constructed by many particles stacked and squeezed together. Our observations indicate that the dynamic process of the toroid formation may be a spiral wound process of the globular subunits.
文摘Idiopathic pulmonary fibrosis(IPF) is a progressive, fatal lung disease with poor survival. The advances made in deciphering IPF have led to the approval of different anti-fibrotic molecules, such as pirfenidone and nintedanib. An increasing number of studies with particles(liposomes, nanoparticles, microspheres, nanopolymersomes and nanoliposomes) modified with different functional groups have demonstrated improvement in lung targeted drug delivery. In the present study, we prepared, characterized, and evaluated spermidine(SPD) modified poly-lactic-co-glycolide nanoparticles(SPD-AKF-PLGA/NPs) as carriers for fluorofenidone(AKF) in order to improve the anti-fibrotic efficacy of this drug in lung. SPD-AKF-PLGA/NPs were prepared and functionalized by modified solvent evaporation method with spermidine(SPD), poly-lactic-co-glycolide-polyethylene glycol(PEG-PLGA) groups. The size of SPD-AKF-PLGA/NPs was 172.5±4.3 nm. The AKF release from nanoparticles was shown to be fit Higuchi model. The A549 cellular uptake of the SPD-Cou-6-NPs group was found to be almost 2-fold higher than that of the Cou-6-NPs group. Free SPD and DFMO were pre-incubated in A549 cells to further prove that the uptake of SPD-Cou-6-PLGA/NPs via PTS. As a result, the uptake of SPD-Cou-6-PLGA/NPs significantly decreased with the increase of SPD concentrations in incubation. At the higher SPD concentrations in 50 and 500 μM, the uptake of SPD-Cou-6-PLGA/NPs reduced 0.34 and 0.49-fold than that without SPD pretreatment. After pretreatment with DFMO for 36 h, the cellular uptake of SPD-Cou-6-NPs reached 1.26-fold compared to untreated DFMO group. In biodistribution study, the drug targeting index of SPD-AKF-PLGA/NPs in lung was 3.62 and 4.66-fold than that of AKF-PLGA/NPs and AKF solution, respectively. It was suggested that the SPD-AKF-PLGA/NPs could accumulate effectively in the lung. The lung histopathology changes and collagen deposition were observed by HE staining and Masson staining in efficacy study. In SPD-AKF-PLGA/NPs group, the damage was further improved compared to that of the AKFPLGA/NPs group and AKF solution group. The results indicated that SPD-AKF-PLGA/NPs could be effective nanocarriers for antipulmonary fibrosis therapy.
文摘The effects of foliar spraying with spermidine (Spd), ranging in concentration from 0.25 to 0.50mmol/L, on the antioxidant system under Cd2+ stress (range 0.1- 0.2 mmol/L Cd2+) in Typha latifolia L.grown hydroponically were investigated in order to offer a referenced evidence for an understanding of the mechanism by which polyamines (PAs) relieve the damage to plants by heavy metal and improve the phytoremediation efficiency of heavy metal-contaminated water. The results showed that Cd2+ stress inhydrogen peroxide (H2O2) and malondialdehyde (MDA) contents in both leaves and caudices. With theexception of superoxide dismutase (SOD) activity in the leaves, an increase in the activities of catalase (CAT), guaiacol peroxidase (GPX), and glutathione reductase (GR) was observed in both leaves and caudices,SOD activity was increased in caudices, and ascorbate peroxidase (APX) activity was increased in leaves following Cd2+ treatment. The reduced glutathione (GSH) content in both leaves and caudices and the reductive ascorbate content in leaves was obviously increased, which were prompted by the application of exogenous Spd. Spraying with Spd increased the activity of GR and APX in both leaves and caudices,whereas the activity of SOD, CAT, and GPX was increased only in caudices following spraying with Spd.with Spd. The decrease in MDA was more obvious following the application of 0.25 than 0.50 mmol/L Spd.It is supposed that exogenous Spd elevated the tolerance of T. latifolia under Cd2+ stress primarily by increasing GR activity and the GSH level.
基金Supported by the National Natural Science Foundation of China(30571119)the Sichuan Science and Technology Foundation(04ZQ026-036 and 05JY029-017)+1 种基金the Education Ministry Doctoral Foundation of China (20040610015)the Chengdu Science and Technology Foundation (05HJSW117)
文摘类脂化合物上的外长的亚精胺(Spd ) 的效果每氧化，相对质膜渗透，相片系统 II (PSII ) 基因表示和 PSII，在强调水的小麦幼苗的光化学的活动被调查。在相对含水量(RWC ) 的减少，迟内容，和 PSII 的 2,6-dichlorophenol in-dophenol (DCIP ) 光致还原，和在强调水的叶子的质膜和 malonyldialdehyde (MDA ) 的电解质漏的增加被 Spd 预告的处理减轻。而且，西方、北的污点分析证明那在 PSII 主要蛋白质 D1， D2 和 LHCII 和相应 genespsbA， psbD 和出租汽车的抄本减少被 Spd 预告的处理也在水应力下面减轻。这些结果建议外长的 Spd 的申请在 thetranscriptional 水平和翻译水平保护 PSII 免于水应力，并且允许 PSII 在水应力期间保留更高的活动水平。在光合的仪器的 Spd 的保护的角色也被讨论。
基金Supported by the National Natural Science Foundation of China (Grant Nos. 10834014, 10674173)National Basic Research Program of China (Grant No. 2009CB930704)
文摘With atomic force microscopy (AFM) we systematically studied the DNA condensations on mica surfaces induced by multivalent cation spermidine. The pattern of the DNA condensates is a flat single layer, with a core in the centre and DNA wrapping around it at high density. We assume this to be a two-dimensional condensation of free coiled DNA onto negatively charged mica surfaces by the multivalent cation. The DNA molecules condense on mica surfaces via a pathway different from the formation of toroids, rods or globules in bulk solutions. We give an explanation to why toroid structures are difficult to be observed by AFM, and further discuss the relationship between DNA condensations in solutions and on mica surfaces. The present work will be helpful for understanding the behaviors of DNA on charged surfaces, which might be significantly different from that in solutions.
