We evaluated the genotypes of the serotonin transporter gene （5-HTT） in patients with premature ejaculation （PE） to determine the role of genetic factors in the etiopathogenesis of PE and possibly to identify the ...We evaluated the genotypes of the serotonin transporter gene （5-HTT） in patients with premature ejaculation （PE） to determine the role of genetic factors in the etiopathogenesis of PE and possibly to identify the patient subgroups. A total of 70 PE patients and 70 controls were included in this study. All men were heterosexual, had no other disorders and were either married or in a stable relationship. PE was defined as ejaculation that occurred within 1 min of vaginal intromission. Genomic DNA from patients and controls was analyzed using polymerase chain reaction, and allelic variations of the promoter region of the serotonin transporter gene （5-HTTLPR） were determined. The 5-HTTLPR （serotonin transporter promoter gene） genotypes in PE patients vs. controls were distributed as follows： L/L 16% vs. 17%, L/S 30% vs. 53% and S/S 54% vs. 28%. We examined the haplotype analysis for three polymorphisms of the 5-HTTLPR gene： LL, LS and SS. The appropriateness of the allele frequencies in the 5-HTTLPR gene was analyzed by the Hardy-Weinberg equilibrium using the Z-test. The short （S） allele of the 5-HTTLPR gene was significantly more frequent in PE patients than in controls （P 〈 0.05）. We suggest that the 5-HTTLPR gene plays a role in the pathophysiology of all primary PE cases. Further studies are needed to evaluate the relationship between 5-HTTLPR gene polymorphism and patient subgroup （such as primary and secondary PE） responses to selective serotonin reuptake inhibitors as well as ethnic differences.展开更多
Aim To characterize the SSRIs sensitivity in C57 and DBA mouse strain and identify the protein struc- tural determinants that contribute to the SSRIs sensitivity. Methods Multiple behavioral assays were conducted to c...Aim To characterize the SSRIs sensitivity in C57 and DBA mouse strain and identify the protein struc- tural determinants that contribute to the SSRIs sensitivity. Methods Multiple behavioral assays were conducted to characterize the SSRIs sensitivity in C57 and DBA mouse strain . We performed in vitro binding and uptake assays to assess the pharmacological properties differences of the SSRIs in C57 and DBA mouse strain. Results The ma- jor difference between the 5-HT transport kinetics of the SERTs was found in their maximal transport capacity rather than the transporter＇ s apparent affinity for 5-HT in two mouse strains. C57 mice displayed a significant loss in cita- lopram sensitivity. DBA mice displayed a significant loss in fluoxetine sensitivity. Paroxetine and YL-0919 displayed the same sensitivity in tow mouse strain. Conclusion Results suggest that the two mouse strain have different re- sponses activity to the treatment of SSRIs. The Kd values for 5-HT transporter binding were significantly different a- mong the five compounds of SSRIs we studied in C57 and DBA mouse strain as well as reuptake assays.展开更多
The human serotonin transporter(SERT)terminates neurotransmission by removing serotonin from the synaptic cleft,which is an essential process that plays an important role in depression.In addition to natural substrate...The human serotonin transporter(SERT)terminates neurotransmission by removing serotonin from the synaptic cleft,which is an essential process that plays an important role in depression.In addition to natural substrate serotonin,SERT is also the target of the abused drug cocaine and,clinically used antidepressants,escitalopram,and paroxetine.To date,few studies have attempted to investigate the unbinding mechanism underlying the orthosteric and allosteric modulation of SERT.In this article,the conserved property of the orthosteric and allosteric sites(S1 and S2)of SERT was revealed by combining the high resolutions of x-ray crystal structures and molecular dynamics(MD)simulations.The residues Tyr95 and Ser438 located within the S1 site,and Arg104 located within the S2 site in SERT illustrate conserved interactions(hydrogen bonds and hydrophobic interactions),as responses to selective serotonin reuptake inhibitors.Van der Waals interactions were keys to designing effective drugs inhibiting SERT and further,electrostatic interactions highlighted escitalopram as a potent antidepressant.We found that cocaine,escitalopram,and paroxetine,whether the S1 site or the S2 site,were more competitive.According to this potential of mean force(PMF)simulations,the new insights reveal the principles of competitive inhibitors that lengths of trails from central SERT to an opening were~18A for serotonin and~22 A for the above-mentioned three drugs.Furthermore,the distance between the natural substrate serotonin and cocaine(or escitalopram)at the allosteric site was~3A.Thus,it can be inferred that the potent antidepressants tended to bind at deeper positions of the S1 or the S2 site of SERT in comparison to the substrate.Continuing exploring the processes of unbinding four ligands against the two target pockets of SERT,this study observed a broad pathway in which serotonin,cocaine,escitalopram(at the S1 site),and paroxetine all were pulled out to an opening between MT1b and MT6a,which may be helpful to understand the dissociation mechanism of antidepressants.展开更多
Objective:To investigate the role of serotonin reuptake transporter(SERT)and P2X3 receptor of dorsal root ganglion(DRG)in regulating visceral hypersensitivity of rats with irritable bowel syndrome(IBS)by electroacupun...Objective:To investigate the role of serotonin reuptake transporter(SERT)and P2X3 receptor of dorsal root ganglion(DRG)in regulating visceral hypersensitivity of rats with irritable bowel syndrome(IBS)by electroacupuncture(EA).Methods:Male Sprague-Dawley and SERT^(-/-)rats were subjected to preparing IBS visceral hypersensitivity models with 2,4,6-trinitrobenzene sulfonic acid(TNBS)enema.Three weeks post-modeling,interventions including EA,intrathecal injection,and EA plus intrathecal injection were applied,respectively.Hematoxylin-eosin staining and abdominal withdrawal reflex(AWR)score were used to confirm the successful establishment of the IBS model.AWR score,whole-cell patch clamp technique,and Western blotting assay were used to evaluate the changes in visceral pain sensitivity,electrophysiological properties of DRG neurons,and the expression of DRG P2X3 receptor and SERT in IBS rats.Results:Compared to the model group,the AWR score in the EA group decreased significantly(P<0.05),the resting membrane potential(P<0.05)and the number of action potentials(P<0.05)of DRG neurons reduced,and the baseline intensity increased(P<0.05);additionally,the expression of P2X3 receptor in DRG decreased(P<0.01),and the SERT expression increased(P<0.05).Compared to the P2X3 receptor agonist group,the SERT protein expression in DRG was higher in the EA group.In SERT^(-/-)rats,the P2X3 receptor expression in DRG increased in the EA group compared to the model group(P<0.01).Conclusion:EA modulates the electrophysiological characteristics of intestinal primary sensory neurons by regulating the expression of SERT and P2X3 receptor in DRG of IBS rats.This modulation may contribute to the mechanism by which EA alleviates peripheral sensitization of visceral pain in IBS rats.展开更多
文摘We evaluated the genotypes of the serotonin transporter gene （5-HTT） in patients with premature ejaculation （PE） to determine the role of genetic factors in the etiopathogenesis of PE and possibly to identify the patient subgroups. A total of 70 PE patients and 70 controls were included in this study. All men were heterosexual, had no other disorders and were either married or in a stable relationship. PE was defined as ejaculation that occurred within 1 min of vaginal intromission. Genomic DNA from patients and controls was analyzed using polymerase chain reaction, and allelic variations of the promoter region of the serotonin transporter gene （5-HTTLPR） were determined. The 5-HTTLPR （serotonin transporter promoter gene） genotypes in PE patients vs. controls were distributed as follows： L/L 16% vs. 17%, L/S 30% vs. 53% and S/S 54% vs. 28%. We examined the haplotype analysis for three polymorphisms of the 5-HTTLPR gene： LL, LS and SS. The appropriateness of the allele frequencies in the 5-HTTLPR gene was analyzed by the Hardy-Weinberg equilibrium using the Z-test. The short （S） allele of the 5-HTTLPR gene was significantly more frequent in PE patients than in controls （P 〈 0.05）. We suggest that the 5-HTTLPR gene plays a role in the pathophysiology of all primary PE cases. Further studies are needed to evaluate the relationship between 5-HTTLPR gene polymorphism and patient subgroup （such as primary and secondary PE） responses to selective serotonin reuptake inhibitors as well as ethnic differences.
文摘Aim To characterize the SSRIs sensitivity in C57 and DBA mouse strain and identify the protein struc- tural determinants that contribute to the SSRIs sensitivity. Methods Multiple behavioral assays were conducted to characterize the SSRIs sensitivity in C57 and DBA mouse strain . We performed in vitro binding and uptake assays to assess the pharmacological properties differences of the SSRIs in C57 and DBA mouse strain. Results The ma- jor difference between the 5-HT transport kinetics of the SERTs was found in their maximal transport capacity rather than the transporter＇ s apparent affinity for 5-HT in two mouse strains. C57 mice displayed a significant loss in cita- lopram sensitivity. DBA mice displayed a significant loss in fluoxetine sensitivity. Paroxetine and YL-0919 displayed the same sensitivity in tow mouse strain. Conclusion Results suggest that the two mouse strain have different re- sponses activity to the treatment of SSRIs. The Kd values for 5-HT transporter binding were significantly different a- mong the five compounds of SSRIs we studied in C57 and DBA mouse strain as well as reuptake assays.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11904036 and 12175081)Fundamental Research Funds for the Central Universities(Grant No.CCNU22QNOO4)。
文摘The human serotonin transporter(SERT)terminates neurotransmission by removing serotonin from the synaptic cleft,which is an essential process that plays an important role in depression.In addition to natural substrate serotonin,SERT is also the target of the abused drug cocaine and,clinically used antidepressants,escitalopram,and paroxetine.To date,few studies have attempted to investigate the unbinding mechanism underlying the orthosteric and allosteric modulation of SERT.In this article,the conserved property of the orthosteric and allosteric sites(S1 and S2)of SERT was revealed by combining the high resolutions of x-ray crystal structures and molecular dynamics(MD)simulations.The residues Tyr95 and Ser438 located within the S1 site,and Arg104 located within the S2 site in SERT illustrate conserved interactions(hydrogen bonds and hydrophobic interactions),as responses to selective serotonin reuptake inhibitors.Van der Waals interactions were keys to designing effective drugs inhibiting SERT and further,electrostatic interactions highlighted escitalopram as a potent antidepressant.We found that cocaine,escitalopram,and paroxetine,whether the S1 site or the S2 site,were more competitive.According to this potential of mean force(PMF)simulations,the new insights reveal the principles of competitive inhibitors that lengths of trails from central SERT to an opening were~18A for serotonin and~22 A for the above-mentioned three drugs.Furthermore,the distance between the natural substrate serotonin and cocaine(or escitalopram)at the allosteric site was~3A.Thus,it can be inferred that the potent antidepressants tended to bind at deeper positions of the S1 or the S2 site of SERT in comparison to the substrate.Continuing exploring the processes of unbinding four ligands against the two target pockets of SERT,this study observed a broad pathway in which serotonin,cocaine,escitalopram(at the S1 site),and paroxetine all were pulled out to an opening between MT1b and MT6a,which may be helpful to understand the dissociation mechanism of antidepressants.
文摘Objective:To investigate the role of serotonin reuptake transporter(SERT)and P2X3 receptor of dorsal root ganglion(DRG)in regulating visceral hypersensitivity of rats with irritable bowel syndrome(IBS)by electroacupuncture(EA).Methods:Male Sprague-Dawley and SERT^(-/-)rats were subjected to preparing IBS visceral hypersensitivity models with 2,4,6-trinitrobenzene sulfonic acid(TNBS)enema.Three weeks post-modeling,interventions including EA,intrathecal injection,and EA plus intrathecal injection were applied,respectively.Hematoxylin-eosin staining and abdominal withdrawal reflex(AWR)score were used to confirm the successful establishment of the IBS model.AWR score,whole-cell patch clamp technique,and Western blotting assay were used to evaluate the changes in visceral pain sensitivity,electrophysiological properties of DRG neurons,and the expression of DRG P2X3 receptor and SERT in IBS rats.Results:Compared to the model group,the AWR score in the EA group decreased significantly(P<0.05),the resting membrane potential(P<0.05)and the number of action potentials(P<0.05)of DRG neurons reduced,and the baseline intensity increased(P<0.05);additionally,the expression of P2X3 receptor in DRG decreased(P<0.01),and the SERT expression increased(P<0.05).Compared to the P2X3 receptor agonist group,the SERT protein expression in DRG was higher in the EA group.In SERT^(-/-)rats,the P2X3 receptor expression in DRG increased in the EA group compared to the model group(P<0.01).Conclusion:EA modulates the electrophysiological characteristics of intestinal primary sensory neurons by regulating the expression of SERT and P2X3 receptor in DRG of IBS rats.This modulation may contribute to the mechanism by which EA alleviates peripheral sensitization of visceral pain in IBS rats.
