Summary: To further investigate the mechanisms of action of icariin (ICA), we assessed the effects of ICA on the in vitro formation of cGMP and cAMP in isolated rabbit corpus cavernosum. Isolated segments of rabbit...Summary: To further investigate the mechanisms of action of icariin (ICA), we assessed the effects of ICA on the in vitro formation of cGMP and cAMP in isolated rabbit corpus cavernosum. Isolated segments of rabbit corpus cavernosum were exposed to increasing concentrations of ICA and the dose-dependent accumulation of cGMP and cAMP was determined in the tissues samples by means of ^125I radioimmunoassay. Responses of the isolated tissues preparations to ICA were compared with those obtained with the reference compounds sildenafil (Sild). Furthermore, the effects of ICA on the mRNA expression of specific cGMP-binding phosphodiesterase type Ⅴ (PDE5) in rat penis were also observed. After incubation with ICA for 6 h or 14 h respectively, the levels of PDE5 mRNA were examined by reverse transcriptase polymerase chain reaction (RT-PCR). The results showed that ICA increased cGMP concentrations directly (P〈0.05), but there was no significant effect on cAMP concentrations (P〉0.05). In the presence of sodium nitroprusside (SNP), a stimulatory agent of cGMP, both ICA and Sild increased cGMP concentrations with increasing dose (P〈0.01). Their EC50 was 4.62 (ICA) and 0.42 (Sild) μmol/L respectively. Under the same condition, ICA and Sild unaltered cAMP level significantly (P〉0.05). There were PDE5A 1 and PDE5A2 mRNA expressions in rat cor- pus cavernosum with PDE5A2 being the dominant isoform. ICA could obviously inhibit these two isoforms mRNA expression in rat penis, and decrease PDE5A1 more pronouncedly (P〈 0.01). The present study indicated that the aphrodisiac mechanisms of icariin involved the NO-cGMP signal transduction pathway, with increasing cGMP levels in the corpus cavernosum smooth muscle. The inhibitory effect of icariin on PDE5 mRNA expression, especially on PDE5A1, might account for its molecular mechanisms for its long-term activity.展开更多
A numerical approach is an effective means of solving boundary value problems(BVPs).This study focuses on physical problems with general partial differential equations(PDEs).It investigates the solution approach throu...A numerical approach is an effective means of solving boundary value problems(BVPs).This study focuses on physical problems with general partial differential equations(PDEs).It investigates the solution approach through the standard forms of the PDE module in COMSOL.Two typical mechanics problems are exemplified:The deflection of a thin plate,which can be addressed with the dedicated finite element module,and the stress of a pure bending beamthat cannot be tackled.The procedure for the two problems regarding the three standard forms required by the PDE module is detailed.The results were in good agreement with the literature,indicating that the PDE module provides a promising means to solve complex PDEs,especially for those a dedicated finite element module has yet to be developed.展开更多
This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering a...This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering and science.An approximate solution of the system is sought in the formof the finite series over the Müntz polynomials.By using the collocation procedure in the time interval,one gets the linear algebraic system for the coefficient of the expansion which can be easily solved numerically by a standard procedure.This technique also serves as the basis for solving the time-fractional partial differential equations(PDEs).The modified radial basis functions are used for spatial approximation of the solution.The collocation in the solution domain transforms the equation into a system of fractional ordinary differential equations similar to the one mentioned above.Several examples have verified the performance of the proposed novel technique with high accuracy and efficiency.展开更多
Phosphodiesterase (PDE) exist various forms for the different structure and property, which is one of key components of light receptors in retinal rod cells. In this paper, cloning the DNA of T-subunits Phosphodiest...Phosphodiesterase (PDE) exist various forms for the different structure and property, which is one of key components of light receptors in retinal rod cells. In this paper, cloning the DNA of T-subunits Phosphodiesterase (γ-PDE6) from cDNA library, constructing the corresponding recombinant plasmid, and purification of the protein after initial expression was studied.展开更多
A Hinf Ⅰ locus of the porcine subunit C of succinate dehydrogenase complex (SDHC) gene and a Msp Ⅰ locus of theporcine rod cGMP-phosphodiesterase γ-subunit (PDE6G) gene had been reported before, but the association...A Hinf Ⅰ locus of the porcine subunit C of succinate dehydrogenase complex (SDHC) gene and a Msp Ⅰ locus of theporcine rod cGMP-phosphodiesterase γ-subunit (PDE6G) gene had been reported before, but the association analysisbetween the different genotypes and the traits had not been done. 300 Large White × Meishan F2 pigs were used asexperimental materials to performe the PCR-RFLP analysis and association analysis for the two loci, results revealed thatthe polymorphism of the porcine subunit C of succinate dehydrogenase complex (SDHC) gene was significantly associatedwith the traits which included the carcass length, the estimated lean meat percentage, the estimated backfat thickness atlast rib, the estimated backfat thickness at last 3-4th rib, the fat meat weight, the fat meat percentage, the lean meat weight,the lean meat percentage, the ratio of lean meat to fat meat, the leaf fat weight, the backfat thickness at shoulder, thebackfat thickness at thorax-Waist, the backfat thickness at 6-7th thorax and the average daily gain. Seven other traits, themeat color value (Biceps femoris, BF), the meat marbling (Biceps femoris, BF), the water moisture (Longissimus dorsi, LD),the bone weight, the bone percentage, the loin eye width and the loin eye area, were found to be significantly correlatedwith the polymorphism of the porcine rod cGMP-phosphodiesterase γ-subunit (PDE6G) gene. Based on these results, itis necessary to apply the two genes as candidate genes to marker assistant selection (MAS) in pig breeding.展开更多
PDE is a supeffamily of enzymes that break down the important second messengers cyclic AMP (cAMP) PDE4 is the most important fami- and cyclic GMP (cGMP). There are 11 PDE families ( PDEI-11 ) ; among them, ly i...PDE is a supeffamily of enzymes that break down the important second messengers cyclic AMP (cAMP) PDE4 is the most important fami- and cyclic GMP (cGMP). There are 11 PDE families ( PDEI-11 ) ; among them, ly in the control of intracellular cAMP signaling. It has been established that PDE4 is an essential player in the me- diation of AD and alcoholism. Chronic alcohol consumption can cause alcohol-related dementia and 50% - 75% of detoxified alcoholics have memory or cognition impairment. The lecture will focus on the unique role of PDE4 and its isoforms (PDE4A-D) in mediating AD and alcoholism and the cellular mechanisms involved. Specifically, using mice deficient in PDE4A, PDE4B, or PDE4D, and their wild type (WT) controls, it was found that PDE4Adeficiencydecreased alcohol intake and preference and reversed Abeta42-induced memory deficits. In con- trast, deficiency of PDE4B only mimicked the ability of PDE4A-deficiency to reduce alcohol consumption, while deficiency of PDE4D only reversed Abeta42-induced memory deficits. In addition, levels of cAMP and phospho- CREB (pCREB) were increased in the hippocampus of mice deficient in PDE4A or PDE4D, which also produced reversal of Abeta42-induced decreases in pCREB. These datasuggest that PDE4 isoforms have different roles in me-diating alcohol-drinking behavior and memoryin Alzheimer' s disease, which are mediated by cAMP/CREB signa- ling. The results indicate PDE4A as a potential new target for alcohol-related dementia, although studies with ani- mal models of alcohol-related dementia are needed to clarify this.展开更多
Backround: Erectile dysfunction (ED) is the inability of male reproductive organs within sexual intercourse caused by neurogenic and hormonal disorders. There are some causes of ED such as hypertension, stress, neurol...Backround: Erectile dysfunction (ED) is the inability of male reproductive organs within sexual intercourse caused by neurogenic and hormonal disorders. There are some causes of ED such as hypertension, stress, neurological disorders, stroke, diabetes, atherosclerosis, lifestyle, alcohol, smoking, and age-related hormonal decline can cause infertility. The natural treatment of sexual dysfunction through aphrodisiac activity of the plant is to increase sexual hormones, spermatogenesis activity and through PDE5 inhibitors such as sildenafil, verdenafil, and tadalafil which can inhibit the hydrolysis of second messenger cGMP of penis smooth muscle cells. Primer Design for amplification of several PDE5 gene nucleotide sequences obtained from NCBI gen banks and tested directly through explosions at NCBI and also using MEGA 6, primer 3 plus, and fast PCR software. The natural treatment of sexual dysfunction through aphrodisiac activity from plants to increase sexual hormone, spermatogenesis activity and inhibitor PDE5 such as sildenafil, vardenafil, and tadalafil can inhibit hydrolysis second messenger of cells cGMP smooth penis muscles. Method: Primer design stages for several sequences are data supply, multiple sequence alignment, sequence trimming, primer design (fastPCR input), in silico PCR analysis, and primer evaluation (Primer Test, OligoCalc and BLAST). Results: Primer of PDE5 that is choosen is with reverse sequence 5-TGCATTGACCATGTCTCTCGTT-3, forward 5-CGCCGATCTGGGCTGAACTA-3 able to amplify template DNA at temperature 67.2°C, 65.8°C, 63.7°C, however, the DNA band fragment looks not very clear, while it is more clearly seen at Tm temperature 61.2°C, 59.1°C, 57.8°C and 57°C. Conclusion: PDE5 primers can be amplified well at temperature 61.2°C, 59.1°C, 57.8°C and 57°C. PDE5 primer succeeded in amplifying DNA with a product length of 402 bp.展开更多
Classical inhibitors of PDE4 lack subtype selectivity due to exact amino acid sequence conservation of the catalytic site,and consequently,development of these drugs has stalled due to dose-limiting side effects of na...Classical inhibitors of PDE4 lack subtype selectivity due to exact amino acid sequence conservation of the catalytic site,and consequently,development of these drugs has stalled due to dose-limiting side effects of nausea and emesis.While use of subtype-selective inhibitors(i.e.,for PDE4A,B,or D)could overcome this issue,conservation of the catalytic region,to which classical inhibitors bind,limits this approach.The present study examined the effects of BPN14770,an allosteric inhibitor of PDE4D,which binds to a primate-specific,N-terminal region,conferring greater than 260-fold selectivity for PDE4D.BPN14770 was 100-fold more potent for improving memory and cognition in humanized PDE4D(hPDE4D)mice,which expressed the primate-specific binding sequence,compared to wild-type mice;meanwhile,it exhibited low potency in a mouse surrogate model for emesis.The behavioral and matching neurochemical data presented established a relationship between PDE4D target engagement and effects on cognition for BPN14770.Furthermore,BPN14770 reversed memory and cognitive deficits induced byβ-amyloid peptide 1-42(Aβ42)in Morris water maze,Y maze and novel object recognition tests in the humanized PDE4D mice.The morphological analyses suggested that the number of dendrites and the dendritic length in the CA1 of hippocampus were significantly increased after the Aβ42-treated hPDE4D mice were administered of BPN14770 for two weeks.The neurochemical and molecular biological assays suggested that neuroplasticity-related proteins and neurotrophic factor BDNF in the hippocampus of hPDE4D mice were significantly increased after the hPDE4D mice were treated with BPN14770.These findings suggest clinical potential for PDE4D selective inhibitors in disorders with cognitive deficits such as Alzheimer’s disease,which affects approximately 20 million people worldwide and nearly 5 million people in the United States.展开更多
The aim of this review study is to elucidate the effects that phosphodiesterase 5 (PDE5) inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger ...The aim of this review study is to elucidate the effects that phosphodiesterase 5 (PDE5) inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase (AC) system and the cGMP/guanylate cyclase (GC) system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide (NO) leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil's actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the improvement of the outcome of assisted reproductive technology (ART) programs. In the future PDE5 inhibitors might serve as adjunct therapeutical agents for the alleviation of male infertility.展开更多
Parkinson disease(PD) is a chronic neurodegenerative disorder caused by progressive dopaminergic neuronal death in the substantia nigra pars compacta within the midbrain.There still is no cure,effective treatments for...Parkinson disease(PD) is a chronic neurodegenerative disorder caused by progressive dopaminergic neuronal death in the substantia nigra pars compacta within the midbrain.There still is no cure,effective treatments for PD,available therapies are only capable of offering temporary and symptomatic relief to the patients.There are certain patents that claim phosphodiesterase(PDE) inhibitors as possible anti-PD drugs,PDE4 is a promising target for the treatment of PD and the underlying mechanism has not yet been well elucidated.PDE4 is an enzyme that specifically hydrolyzes intracellular cyclic adenosine monophosphate(cAMP)throughout the body,including the brain.Most of the available PDE4 inhibitors exert unpleasant and serious side effects,such as emesis and nausea,which hinder its clinical application.Therefore,more efforts are needed before PDE4 inhibitors with high therapeutic indices are available for treatment of PD.FCPR16 is a novel PDE4 inhibitor with little emetic potential,which exhibits excellent enzyme inhibition activity(IC50=90 nmol·L^(-1)).METHODS SH-SY5 Y cell was induced with 1-methyl-4-phenylpyridinium(MPP+)to mimic PD cell injury in vitro,and CCK-8 assay was used to investigate the viability effects of different concentration of FCPR16(3.1-50 μmol·L^(-1)) on MPP+-injured SH-SY5 Y cells.Detection of apoptosis was performed by flow cytometry.The level of ntracellular reactive oxygen species was detected with the fluorescent probe DCFH-DA,and the mitochondrial membrane potential of cells in different experimental groups was detected with the JC-1 fluorescent probe.AO staining and Lysotracker Red staining were used to detect the intracellular antophagy changes.The expression of apoptosis related proteins,autophagy and other related signal molecules were demonstrated by Western blotting.Different cellular signaling pathway inhibitors were used to invesitigate the specific cellular mechanisms of FCPR16 protecting MPP+-induced cell injury.RESULTS FCPR16(12.5-50 μmol·L^(-1)) dose-dependently reduced MPP+-induced decline of cell viability,accompanied by reductions in nuclear condensation and lactate dehydrogenase release.The level of cleaved caspase 3 and the ratio of Bax/Bcl-2 were also decreased after treatment with FCPR16 in MPP+-treated cells.Furthermore,FCPR16(25 μmol·L^(-1)) significantly suppressed the accumulation of reactive oxygen species(ROS),prevented the decline of mitochondrial membrane potential(Δψm) and attenuated the expression of malonaldehyde level.Further studies disclosed that FCPR16 enhanced the levels of cA MP and the exchange protein directly activated by cA MP(Epac) in SHSY5 Y cel s.Western blotting analysis revealed that FCPR16 increased the phosphorylation of c AMP response element-binding protein(CREB) and protein kinase B(Akt)down-regulated by MPP+in SHSY5 Y cells.Moreover,the inhibitory effects of FCPR16 on the production of ROS and Δψm loss could be blocked by PKA inhibitor H-89 and Akt inhibitor KRX-0401.CONCLUSION The novel PDE4 inhibitor FCPR16 can protect against damaging pathways including oxidative stress,mitochondrial dysfunction and apoptosis in SH-SY5 Y cells.FCPR16 preventes MPP+-induced neurotoxicity through activation of cAMP/PKA/CREB and Epac/Akt signaling pathways.These may lead to develop mechanism based therapeutics and improved pharmacotherapy for PD.It is reasonable to assume that FCPR16 is a potential candidate for the prevention and treatment of PD.展开更多
Luteolin is an active ingredient found early from Fofium perillae and Flos Ionicerae, and has a specific inhibition on phosphodiesterase 4 (PDE4) activity in vitro. Researches show luteolin has pharmacological effec...Luteolin is an active ingredient found early from Fofium perillae and Flos Ionicerae, and has a specific inhibition on phosphodiesterase 4 (PDE4) activity in vitro. Researches show luteolin has pharmacological effects of anti-inflammation, anti-anaphylaxis, antitumor, antioxidant, protection of nervous system and so on, and has mainly been used for the treatment of respiratory inflammatory diseases, cancer and cardiovascular disease in clinic. PDE4, specific to hydrolyze cyclic AMP (cAMP), is considered to be a new anti-inflammatory target due to the decisive role on cAMP signal in inflammatory cells such as neutrophils. In order to explore the anti-inflammatory mechanism, we further studied the effects of luteolin on the activity and expression of PDE4, the expression of lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 (MAC-l) in neutrophils, and the adhesion of neutrophils and endothelial cells. The results showed that luteolin had a dose-dependent inhibition on both bare PDE4 activity and PDE4 in cultured neutrophils, and had an obviously promotive effect on gene expressions of PDE4A, 4B and 4D in later period. Luteolin had a significant inhibitory effect on neutrophils adhesion and LFA-1 expression in early stage, and had no obvious effect on MAC-1 expression. Therefore, luteolin can inhibit LFA-1 expression of neutrophils, then inhibit the adhesion of neutrophils and endothelial cells, and the mechanism is at least related with the inhibition of PDE4 activity.展开更多
Our previous studies showed that the anti-inflammatory effects of Paeonia lactiflora roots extract may be mediated, at least in part, through its gallic acid content, and this effect may be regulated in part by an inh...Our previous studies showed that the anti-inflammatory effects of Paeonia lactiflora roots extract may be mediated, at least in part, through its gallic acid content, and this effect may be regulated in part by an inhibition on c AMP-phosphodiesterase(PDE). To explore the anti-inflammatory effect and mechanism, the influence of gallic acid on neutrophils PDE4 activity and expression, TNF-α and IL-6 content and rat arthritis model were further studied. PDE4 activity and gene express were calculated respectively by substrate c AMP change examined with HPLC and real-time RT-PCR. The concentration of IL-6 and TNF-α in supernatant were assayed by ELISA method. Model of rat arthritis was caused by complete Freund's adjuvant. Results showed that gallic acid had a dose-dependent restraint on PDE4 activity of neutrophils in vitro, promoted significantly PDE4 A expression(P〈0.01), and had no influence on the expressions of PDE4 B and 4D. However, PDE4 C expression was not detected. Gallic acid could promote IL-6 release(P〈0.05), and inhibit TNF-α release of neutrophils(P〈0.05). The experiment in vivo showed that gallic acid had obvious restraint on local inflammation of animal model(P〈0.05). Therefore, the anti-inflammatory effect of gallic acid may be mediated in part through an inhibition on PDE4 activity and further an increase of IL-6 and a decrease of TNF-α of neutrophils, and this effect seemed to have no relationship with PDE4 expression.展开更多
The importance of nitric oxide(NO) in vascular physiology is irrefutable;it stimulates the intracellular production of cyclic guanosine monophosphate(cGMP),initiating vascular smooth muscle relaxation.This biochemical...The importance of nitric oxide(NO) in vascular physiology is irrefutable;it stimulates the intracellular production of cyclic guanosine monophosphate(cGMP),initiating vascular smooth muscle relaxation.This biochemical process increases the diameter of small arteries,regulating blood flow distribution between arterioles and the microvasculature.The kidney is no exception,since NO predominantly dilates the glomerular afferent arterioles.It is now evident that the vascular production of cGMP can be augmented by inhibitors of phosphodiesterase type 5(PDE 5),the enzyme which breakdowns this cyclic nucleotide.This has clinical relevance,since diabetic nephropathy(DN) a major microvascular complication of diabetes mellitus and the most common cause of end-stage renal disease,increases intraglomerular capillary pressure,leading to glomerular hypertension.PDE 5 inhibitors may have,therefore,the potential to reduce glomerular hypertension.This review describes the use of PDE 5 inhibitors to improve the metabolic,haemodynamic and inflammatory pathways/responses,all of which are dysfunctional in DN.展开更多
The purpose of this study was to determine the incidence rate of prostate cancer among men with erectile dysfunction (ED) treated with phosphodiesterase type 5 inhibitors (PDE-5i) over a 7-year period vs. men with...The purpose of this study was to determine the incidence rate of prostate cancer among men with erectile dysfunction (ED) treated with phosphodiesterase type 5 inhibitors (PDE-5i) over a 7-year period vs. men with ED of the same age and with similar risk factors who were not treated with PDE-5i. In a retrospective review of electronic medical records and billing databases between the years 2000 and 2006, men with ED between the ages of 50 and 69 years and no history of prostate cancer prior to 2000 were identified. These individuals were divided into two groups: 2362 men who had treatment with PDE-5i, and 2612 men who did not have treatment. Demographic data in each group were compared. During the study period, 97 (4.1%) men with ED treated with PDE-5i were diagnosed with prostate cancer compared with 258 (9.9%) men with ED in the non-treated group (P〈00001). A higher percentage of African Americans were treated with PDE-5i vs. those who were not (10.5% vs. 7.1%; P〈O.O001). The PDE-5i group had lower documented diagnosis of elevated prostate-specific antigen (10.0% vs. 13.1%; P=-0.0008) and higher percentage of benign prostatic hyperplasia (38.4% vs. 35.1%; P=0.0149). Men with ED treated with PDE-5i tended to have less chance (adjusted odds ratio: 0.4; 95% confidence intervals: 0.3-0.5; P〈0.0001) of having prostate cancer. Our data suggest that men with ED treated with PDE-5i tended to have less of a chance of beine diaenosed with orostate cancer. Further research is warranted.展开更多
文摘Summary: To further investigate the mechanisms of action of icariin (ICA), we assessed the effects of ICA on the in vitro formation of cGMP and cAMP in isolated rabbit corpus cavernosum. Isolated segments of rabbit corpus cavernosum were exposed to increasing concentrations of ICA and the dose-dependent accumulation of cGMP and cAMP was determined in the tissues samples by means of ^125I radioimmunoassay. Responses of the isolated tissues preparations to ICA were compared with those obtained with the reference compounds sildenafil (Sild). Furthermore, the effects of ICA on the mRNA expression of specific cGMP-binding phosphodiesterase type Ⅴ (PDE5) in rat penis were also observed. After incubation with ICA for 6 h or 14 h respectively, the levels of PDE5 mRNA were examined by reverse transcriptase polymerase chain reaction (RT-PCR). The results showed that ICA increased cGMP concentrations directly (P〈0.05), but there was no significant effect on cAMP concentrations (P〉0.05). In the presence of sodium nitroprusside (SNP), a stimulatory agent of cGMP, both ICA and Sild increased cGMP concentrations with increasing dose (P〈0.01). Their EC50 was 4.62 (ICA) and 0.42 (Sild) μmol/L respectively. Under the same condition, ICA and Sild unaltered cAMP level significantly (P〉0.05). There were PDE5A 1 and PDE5A2 mRNA expressions in rat cor- pus cavernosum with PDE5A2 being the dominant isoform. ICA could obviously inhibit these two isoforms mRNA expression in rat penis, and decrease PDE5A1 more pronouncedly (P〈 0.01). The present study indicated that the aphrodisiac mechanisms of icariin involved the NO-cGMP signal transduction pathway, with increasing cGMP levels in the corpus cavernosum smooth muscle. The inhibitory effect of icariin on PDE5 mRNA expression, especially on PDE5A1, might account for its molecular mechanisms for its long-term activity.
基金supported by the National Natural Science Foundations of China(Grant Nos.12372073 and U20B2013)the Natural Science Basic Research Program of Shaanxi(Program No.2023-JC-QN-0030).
文摘A numerical approach is an effective means of solving boundary value problems(BVPs).This study focuses on physical problems with general partial differential equations(PDEs).It investigates the solution approach through the standard forms of the PDE module in COMSOL.Two typical mechanics problems are exemplified:The deflection of a thin plate,which can be addressed with the dedicated finite element module,and the stress of a pure bending beamthat cannot be tackled.The procedure for the two problems regarding the three standard forms required by the PDE module is detailed.The results were in good agreement with the literature,indicating that the PDE module provides a promising means to solve complex PDEs,especially for those a dedicated finite element module has yet to be developed.
基金funded by the National Key Research and Development Program of China(No.2021YFB2600704)the National Natural Science Foundation of China(No.52171272)the Significant Science and Technology Project of the Ministry of Water Resources of China(No.SKS-2022112).
文摘This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering and science.An approximate solution of the system is sought in the formof the finite series over the Müntz polynomials.By using the collocation procedure in the time interval,one gets the linear algebraic system for the coefficient of the expansion which can be easily solved numerically by a standard procedure.This technique also serves as the basis for solving the time-fractional partial differential equations(PDEs).The modified radial basis functions are used for spatial approximation of the solution.The collocation in the solution domain transforms the equation into a system of fractional ordinary differential equations similar to the one mentioned above.Several examples have verified the performance of the proposed novel technique with high accuracy and efficiency.
文摘Phosphodiesterase (PDE) exist various forms for the different structure and property, which is one of key components of light receptors in retinal rod cells. In this paper, cloning the DNA of T-subunits Phosphodiesterase (γ-PDE6) from cDNA library, constructing the corresponding recombinant plasmid, and purification of the protein after initial expression was studied.
文摘A Hinf Ⅰ locus of the porcine subunit C of succinate dehydrogenase complex (SDHC) gene and a Msp Ⅰ locus of theporcine rod cGMP-phosphodiesterase γ-subunit (PDE6G) gene had been reported before, but the association analysisbetween the different genotypes and the traits had not been done. 300 Large White × Meishan F2 pigs were used asexperimental materials to performe the PCR-RFLP analysis and association analysis for the two loci, results revealed thatthe polymorphism of the porcine subunit C of succinate dehydrogenase complex (SDHC) gene was significantly associatedwith the traits which included the carcass length, the estimated lean meat percentage, the estimated backfat thickness atlast rib, the estimated backfat thickness at last 3-4th rib, the fat meat weight, the fat meat percentage, the lean meat weight,the lean meat percentage, the ratio of lean meat to fat meat, the leaf fat weight, the backfat thickness at shoulder, thebackfat thickness at thorax-Waist, the backfat thickness at 6-7th thorax and the average daily gain. Seven other traits, themeat color value (Biceps femoris, BF), the meat marbling (Biceps femoris, BF), the water moisture (Longissimus dorsi, LD),the bone weight, the bone percentage, the loin eye width and the loin eye area, were found to be significantly correlatedwith the polymorphism of the porcine rod cGMP-phosphodiesterase γ-subunit (PDE6G) gene. Based on these results, itis necessary to apply the two genes as candidate genes to marker assistant selection (MAS) in pig breeding.
文摘PDE is a supeffamily of enzymes that break down the important second messengers cyclic AMP (cAMP) PDE4 is the most important fami- and cyclic GMP (cGMP). There are 11 PDE families ( PDEI-11 ) ; among them, ly in the control of intracellular cAMP signaling. It has been established that PDE4 is an essential player in the me- diation of AD and alcoholism. Chronic alcohol consumption can cause alcohol-related dementia and 50% - 75% of detoxified alcoholics have memory or cognition impairment. The lecture will focus on the unique role of PDE4 and its isoforms (PDE4A-D) in mediating AD and alcoholism and the cellular mechanisms involved. Specifically, using mice deficient in PDE4A, PDE4B, or PDE4D, and their wild type (WT) controls, it was found that PDE4Adeficiencydecreased alcohol intake and preference and reversed Abeta42-induced memory deficits. In con- trast, deficiency of PDE4B only mimicked the ability of PDE4A-deficiency to reduce alcohol consumption, while deficiency of PDE4D only reversed Abeta42-induced memory deficits. In addition, levels of cAMP and phospho- CREB (pCREB) were increased in the hippocampus of mice deficient in PDE4A or PDE4D, which also produced reversal of Abeta42-induced decreases in pCREB. These datasuggest that PDE4 isoforms have different roles in me-diating alcohol-drinking behavior and memoryin Alzheimer' s disease, which are mediated by cAMP/CREB signa- ling. The results indicate PDE4A as a potential new target for alcohol-related dementia, although studies with ani- mal models of alcohol-related dementia are needed to clarify this.
文摘Backround: Erectile dysfunction (ED) is the inability of male reproductive organs within sexual intercourse caused by neurogenic and hormonal disorders. There are some causes of ED such as hypertension, stress, neurological disorders, stroke, diabetes, atherosclerosis, lifestyle, alcohol, smoking, and age-related hormonal decline can cause infertility. The natural treatment of sexual dysfunction through aphrodisiac activity of the plant is to increase sexual hormones, spermatogenesis activity and through PDE5 inhibitors such as sildenafil, verdenafil, and tadalafil which can inhibit the hydrolysis of second messenger cGMP of penis smooth muscle cells. Primer Design for amplification of several PDE5 gene nucleotide sequences obtained from NCBI gen banks and tested directly through explosions at NCBI and also using MEGA 6, primer 3 plus, and fast PCR software. The natural treatment of sexual dysfunction through aphrodisiac activity from plants to increase sexual hormone, spermatogenesis activity and inhibitor PDE5 such as sildenafil, vardenafil, and tadalafil can inhibit hydrolysis second messenger of cells cGMP smooth penis muscles. Method: Primer design stages for several sequences are data supply, multiple sequence alignment, sequence trimming, primer design (fastPCR input), in silico PCR analysis, and primer evaluation (Primer Test, OligoCalc and BLAST). Results: Primer of PDE5 that is choosen is with reverse sequence 5-TGCATTGACCATGTCTCTCGTT-3, forward 5-CGCCGATCTGGGCTGAACTA-3 able to amplify template DNA at temperature 67.2°C, 65.8°C, 63.7°C, however, the DNA band fragment looks not very clear, while it is more clearly seen at Tm temperature 61.2°C, 59.1°C, 57.8°C and 57°C. Conclusion: PDE5 primers can be amplified well at temperature 61.2°C, 59.1°C, 57.8°C and 57°C. PDE5 primer succeeded in amplifying DNA with a product length of 402 bp.
文摘Classical inhibitors of PDE4 lack subtype selectivity due to exact amino acid sequence conservation of the catalytic site,and consequently,development of these drugs has stalled due to dose-limiting side effects of nausea and emesis.While use of subtype-selective inhibitors(i.e.,for PDE4A,B,or D)could overcome this issue,conservation of the catalytic region,to which classical inhibitors bind,limits this approach.The present study examined the effects of BPN14770,an allosteric inhibitor of PDE4D,which binds to a primate-specific,N-terminal region,conferring greater than 260-fold selectivity for PDE4D.BPN14770 was 100-fold more potent for improving memory and cognition in humanized PDE4D(hPDE4D)mice,which expressed the primate-specific binding sequence,compared to wild-type mice;meanwhile,it exhibited low potency in a mouse surrogate model for emesis.The behavioral and matching neurochemical data presented established a relationship between PDE4D target engagement and effects on cognition for BPN14770.Furthermore,BPN14770 reversed memory and cognitive deficits induced byβ-amyloid peptide 1-42(Aβ42)in Morris water maze,Y maze and novel object recognition tests in the humanized PDE4D mice.The morphological analyses suggested that the number of dendrites and the dendritic length in the CA1 of hippocampus were significantly increased after the Aβ42-treated hPDE4D mice were administered of BPN14770 for two weeks.The neurochemical and molecular biological assays suggested that neuroplasticity-related proteins and neurotrophic factor BDNF in the hippocampus of hPDE4D mice were significantly increased after the hPDE4D mice were treated with BPN14770.These findings suggest clinical potential for PDE4D selective inhibitors in disorders with cognitive deficits such as Alzheimer’s disease,which affects approximately 20 million people worldwide and nearly 5 million people in the United States.
文摘The aim of this review study is to elucidate the effects that phosphodiesterase 5 (PDE5) inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase (AC) system and the cGMP/guanylate cyclase (GC) system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide (NO) leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil's actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the improvement of the outcome of assisted reproductive technology (ART) programs. In the future PDE5 inhibitors might serve as adjunct therapeutical agents for the alleviation of male infertility.
基金NationalNatural Science Foundation of China (81773698)Funding from Guangzhou Science and Technology Department (2015B020211007,201604020112).
文摘Parkinson disease(PD) is a chronic neurodegenerative disorder caused by progressive dopaminergic neuronal death in the substantia nigra pars compacta within the midbrain.There still is no cure,effective treatments for PD,available therapies are only capable of offering temporary and symptomatic relief to the patients.There are certain patents that claim phosphodiesterase(PDE) inhibitors as possible anti-PD drugs,PDE4 is a promising target for the treatment of PD and the underlying mechanism has not yet been well elucidated.PDE4 is an enzyme that specifically hydrolyzes intracellular cyclic adenosine monophosphate(cAMP)throughout the body,including the brain.Most of the available PDE4 inhibitors exert unpleasant and serious side effects,such as emesis and nausea,which hinder its clinical application.Therefore,more efforts are needed before PDE4 inhibitors with high therapeutic indices are available for treatment of PD.FCPR16 is a novel PDE4 inhibitor with little emetic potential,which exhibits excellent enzyme inhibition activity(IC50=90 nmol·L^(-1)).METHODS SH-SY5 Y cell was induced with 1-methyl-4-phenylpyridinium(MPP+)to mimic PD cell injury in vitro,and CCK-8 assay was used to investigate the viability effects of different concentration of FCPR16(3.1-50 μmol·L^(-1)) on MPP+-injured SH-SY5 Y cells.Detection of apoptosis was performed by flow cytometry.The level of ntracellular reactive oxygen species was detected with the fluorescent probe DCFH-DA,and the mitochondrial membrane potential of cells in different experimental groups was detected with the JC-1 fluorescent probe.AO staining and Lysotracker Red staining were used to detect the intracellular antophagy changes.The expression of apoptosis related proteins,autophagy and other related signal molecules were demonstrated by Western blotting.Different cellular signaling pathway inhibitors were used to invesitigate the specific cellular mechanisms of FCPR16 protecting MPP+-induced cell injury.RESULTS FCPR16(12.5-50 μmol·L^(-1)) dose-dependently reduced MPP+-induced decline of cell viability,accompanied by reductions in nuclear condensation and lactate dehydrogenase release.The level of cleaved caspase 3 and the ratio of Bax/Bcl-2 were also decreased after treatment with FCPR16 in MPP+-treated cells.Furthermore,FCPR16(25 μmol·L^(-1)) significantly suppressed the accumulation of reactive oxygen species(ROS),prevented the decline of mitochondrial membrane potential(Δψm) and attenuated the expression of malonaldehyde level.Further studies disclosed that FCPR16 enhanced the levels of cA MP and the exchange protein directly activated by cA MP(Epac) in SHSY5 Y cel s.Western blotting analysis revealed that FCPR16 increased the phosphorylation of c AMP response element-binding protein(CREB) and protein kinase B(Akt)down-regulated by MPP+in SHSY5 Y cells.Moreover,the inhibitory effects of FCPR16 on the production of ROS and Δψm loss could be blocked by PKA inhibitor H-89 and Akt inhibitor KRX-0401.CONCLUSION The novel PDE4 inhibitor FCPR16 can protect against damaging pathways including oxidative stress,mitochondrial dysfunction and apoptosis in SH-SY5 Y cells.FCPR16 preventes MPP+-induced neurotoxicity through activation of cAMP/PKA/CREB and Epac/Akt signaling pathways.These may lead to develop mechanism based therapeutics and improved pharmacotherapy for PD.It is reasonable to assume that FCPR16 is a potential candidate for the prevention and treatment of PD.
基金financial support of the Beijing Natural Science Foundation, China (6112007)the National Natural Science Foundation of China (31101851)+1 种基金the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality, China (PHR201107134)the Comprehensive Reforming Project to promote talents training of Beijing University of Agriculture, China (BNRC&GG201404)
文摘Luteolin is an active ingredient found early from Fofium perillae and Flos Ionicerae, and has a specific inhibition on phosphodiesterase 4 (PDE4) activity in vitro. Researches show luteolin has pharmacological effects of anti-inflammation, anti-anaphylaxis, antitumor, antioxidant, protection of nervous system and so on, and has mainly been used for the treatment of respiratory inflammatory diseases, cancer and cardiovascular disease in clinic. PDE4, specific to hydrolyze cyclic AMP (cAMP), is considered to be a new anti-inflammatory target due to the decisive role on cAMP signal in inflammatory cells such as neutrophils. In order to explore the anti-inflammatory mechanism, we further studied the effects of luteolin on the activity and expression of PDE4, the expression of lymphocyte function-associated antigen-1 (LFA-1) and macrophage-1 (MAC-l) in neutrophils, and the adhesion of neutrophils and endothelial cells. The results showed that luteolin had a dose-dependent inhibition on both bare PDE4 activity and PDE4 in cultured neutrophils, and had an obviously promotive effect on gene expressions of PDE4A, 4B and 4D in later period. Luteolin had a significant inhibitory effect on neutrophils adhesion and LFA-1 expression in early stage, and had no obvious effect on MAC-1 expression. Therefore, luteolin can inhibit LFA-1 expression of neutrophils, then inhibit the adhesion of neutrophils and endothelial cells, and the mechanism is at least related with the inhibition of PDE4 activity.
基金financial support of the Beijing Natural Science Foundation of China (6112007)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality,China (PHR201107134)2012 Scientific Research Quality Raising Funds of Beijing University of Agriculture,China (PXM2012_014207_000010/ PXM2012_014207_000013)
文摘Our previous studies showed that the anti-inflammatory effects of Paeonia lactiflora roots extract may be mediated, at least in part, through its gallic acid content, and this effect may be regulated in part by an inhibition on c AMP-phosphodiesterase(PDE). To explore the anti-inflammatory effect and mechanism, the influence of gallic acid on neutrophils PDE4 activity and expression, TNF-α and IL-6 content and rat arthritis model were further studied. PDE4 activity and gene express were calculated respectively by substrate c AMP change examined with HPLC and real-time RT-PCR. The concentration of IL-6 and TNF-α in supernatant were assayed by ELISA method. Model of rat arthritis was caused by complete Freund's adjuvant. Results showed that gallic acid had a dose-dependent restraint on PDE4 activity of neutrophils in vitro, promoted significantly PDE4 A expression(P〈0.01), and had no influence on the expressions of PDE4 B and 4D. However, PDE4 C expression was not detected. Gallic acid could promote IL-6 release(P〈0.05), and inhibit TNF-α release of neutrophils(P〈0.05). The experiment in vivo showed that gallic acid had obvious restraint on local inflammation of animal model(P〈0.05). Therefore, the anti-inflammatory effect of gallic acid may be mediated in part through an inhibition on PDE4 activity and further an increase of IL-6 and a decrease of TNF-α of neutrophils, and this effect seemed to have no relationship with PDE4 expression.
文摘The importance of nitric oxide(NO) in vascular physiology is irrefutable;it stimulates the intracellular production of cyclic guanosine monophosphate(cGMP),initiating vascular smooth muscle relaxation.This biochemical process increases the diameter of small arteries,regulating blood flow distribution between arterioles and the microvasculature.The kidney is no exception,since NO predominantly dilates the glomerular afferent arterioles.It is now evident that the vascular production of cGMP can be augmented by inhibitors of phosphodiesterase type 5(PDE 5),the enzyme which breakdowns this cyclic nucleotide.This has clinical relevance,since diabetic nephropathy(DN) a major microvascular complication of diabetes mellitus and the most common cause of end-stage renal disease,increases intraglomerular capillary pressure,leading to glomerular hypertension.PDE 5 inhibitors may have,therefore,the potential to reduce glomerular hypertension.This review describes the use of PDE 5 inhibitors to improve the metabolic,haemodynamic and inflammatory pathways/responses,all of which are dysfunctional in DN.
文摘The purpose of this study was to determine the incidence rate of prostate cancer among men with erectile dysfunction (ED) treated with phosphodiesterase type 5 inhibitors (PDE-5i) over a 7-year period vs. men with ED of the same age and with similar risk factors who were not treated with PDE-5i. In a retrospective review of electronic medical records and billing databases between the years 2000 and 2006, men with ED between the ages of 50 and 69 years and no history of prostate cancer prior to 2000 were identified. These individuals were divided into two groups: 2362 men who had treatment with PDE-5i, and 2612 men who did not have treatment. Demographic data in each group were compared. During the study period, 97 (4.1%) men with ED treated with PDE-5i were diagnosed with prostate cancer compared with 258 (9.9%) men with ED in the non-treated group (P〈00001). A higher percentage of African Americans were treated with PDE-5i vs. those who were not (10.5% vs. 7.1%; P〈O.O001). The PDE-5i group had lower documented diagnosis of elevated prostate-specific antigen (10.0% vs. 13.1%; P=-0.0008) and higher percentage of benign prostatic hyperplasia (38.4% vs. 35.1%; P=0.0149). Men with ED treated with PDE-5i tended to have less chance (adjusted odds ratio: 0.4; 95% confidence intervals: 0.3-0.5; P〈0.0001) of having prostate cancer. Our data suggest that men with ED treated with PDE-5i tended to have less of a chance of beine diaenosed with orostate cancer. Further research is warranted.