Background: 5-HT4receptors in cortex and hippocampus area are considered as a possible target for modulation of cognitive functions in Alzheimer’s disease (AD). A systems pharmacology approach was adopted to evaluate...Background: 5-HT4receptors in cortex and hippocampus area are considered as a possible target for modulation of cognitive functions in Alzheimer’s disease (AD). A systems pharmacology approach was adopted to evaluate the potential of the 5-HT4 modulation in providing beneficialeffects on cognition in AD. Methods: A serotonergic synaptic cleft model was developed by integrating serotonin firing, release, synaptic half-life, drug/tracer properties (affinity and agonism) as inputs and5-HT4 activity as output. The serotonergic model was calibrated using bothinvivo data on free 5-HT levels in preclinical models and human imaging data. The model was further expanded to other neurontransmitter systems and incorporated into a computer-based cortical network model which implemented the physiology of 12 different membrane CNS targets. A biophysically realistic, multi-compartment model of 80 pyramidal cells and 40 interneurons was further calibrated usingdata reported for working memory tasks in healthyhumans and schizophrenia patients. Model output was the duration of the network firing activity in response to an external stimulus. Alzheimer’s disease (AD) pathology, in particular synapse and neuronal cell loss in addition to cholinergic deficits, was calibrated to align with the natural clinical disease progression. The model was used to provide insights into the effect of 5-HT4 activation on working memory and to prospectively simulate the response of PF- 04995274, a 5-HT4partial agonist, in a scopolamine-reversal trial in healthy human subjects. Results: The model output suggested a beneficial effect of 5-HT4 agonism on working memory. The model also projected no effect or an exacerbation of scopolamine impairment for low in- trinsic activity 5-HT4agonists, which was supported by the subsequent human trial outcome. The clinical prediction of the disease model strongly suggests that 5-HT4 agonists with high intrinsic activity may have a beneficial effect on cognition in AD patients.展开更多
Objective:Clinical and laboratory studies have demonstrated that prelimbic(PrL)and serotonin-4(5-HT4)receptors may have the key role in regulating anxiety.However,the pathophysiology of anxiety in Parkinson’s disease...Objective:Clinical and laboratory studies have demonstrated that prelimbic(PrL)and serotonin-4(5-HT4)receptors may have the key role in regulating anxiety.However,the pathophysiology of anxiety in Parkinson’s disease(PD)remains obscure.In this research,the effects of PrL 5-HT4 receptors on anti-anxiety behaviors in hemiparkinsonian rats were investigated.Methods:PD model rats were used as the research subjects,starting with behavioral changes,from the point of view of electrophysiology,the regulatory effect of PrL 5-HT4 receptors on PD-related anxiety and the possible mechanism were explored.Results:Anxiety-like behaviors were induced via MFB lesion in rats.Intra-PrL injection of 5-HT4 receptors agonist RS67333 induced anti-anxiety effects in both sham and PD group.In the sham group,PrL administration of 5-HT4 receptors antagonist SB204070 produce anti-anxiety effects,but in the PD group,the expression of anxiety-like behavior was increased.Compared to the sham group,the effective dose of the behavioral effects of the two drugs in the PD group was obviously higher.Electrophysiological data suggested that PrL administration of RS67333(SB204070)increased(decreased)the firing activities ofγ-aminobutyric acid(GABA)neurons in both groups.Compared with rats in sham group,lesioned rats had a shorter duration of the excitation(inhibition)effects on firing activities of GABA neurons.Conclusion:PrL 5-HT4 receptors regulate anxiety behaviors in PD rats,and its mechanism may be related to the down-regulation of expression or function of PrL 5-HT4 receptors in PD.展开更多
The human endogenous retroviruses type W family envelope(HERV-W env)gene is located on chromosome 7q21-22.Our previous studies show that HERV-W env is elevated in schizophrenia and HERV-W env can increase cal-cium inf...The human endogenous retroviruses type W family envelope(HERV-W env)gene is located on chromosome 7q21-22.Our previous studies show that HERV-W env is elevated in schizophrenia and HERV-W env can increase cal-cium influx.Additionally,the 5-HTergie system and particularly 5-hydroxytryptamine(5-HT)receptors play a prominent role in the pathogenesis and treatment of schizophrenia.5-hydroxytryptamine receptor 4(5-HT4R)agonist can block calcium channels.However,the underlying relationship between HERV-W env and 5-HT4R in the etiology of schizophrenia has not been revealed.Here,we used enzyme-linked immunosorbent assay to detect the concentration of HERV-W env and 5-HT4R in the plasma of patients with schizophrenia and we found that there were decreased levels of 5-HT4R and a negative correlation between 5-HT4R and HERV-W env in schizophrenia.Overexpression of HERV-W env decreased the transcription and protein levels of 5-HT4R but increased small conductance Ca^(2+)-activated K^(+)type 2 channels(SK2)expression levels.Further studies revealed that HERV-w env could interact with 5-HT4R.Additionally,luciferase assay showed that an essential region(-364 to-176 from the transcription start site)in the SK2 promoter was required for HERV-W env-induced SK2 expression.Importantly,5-HT4R participated in the regulation of SK2 expression and promoter activity.Electrophysiological recordings suggested that HERV-Wenv could increase SK2 channel currents and the increase of SK2 currents was inhibited by 5-HT4R.In condusion,HERV-W env could activate SK2 channels via decreased 5-HT4R,which might exhibit a novel mechanism for HERV-Wenv to influence neuronal activity in schizophrenia.展开更多
文摘Background: 5-HT4receptors in cortex and hippocampus area are considered as a possible target for modulation of cognitive functions in Alzheimer’s disease (AD). A systems pharmacology approach was adopted to evaluate the potential of the 5-HT4 modulation in providing beneficialeffects on cognition in AD. Methods: A serotonergic synaptic cleft model was developed by integrating serotonin firing, release, synaptic half-life, drug/tracer properties (affinity and agonism) as inputs and5-HT4 activity as output. The serotonergic model was calibrated using bothinvivo data on free 5-HT levels in preclinical models and human imaging data. The model was further expanded to other neurontransmitter systems and incorporated into a computer-based cortical network model which implemented the physiology of 12 different membrane CNS targets. A biophysically realistic, multi-compartment model of 80 pyramidal cells and 40 interneurons was further calibrated usingdata reported for working memory tasks in healthyhumans and schizophrenia patients. Model output was the duration of the network firing activity in response to an external stimulus. Alzheimer’s disease (AD) pathology, in particular synapse and neuronal cell loss in addition to cholinergic deficits, was calibrated to align with the natural clinical disease progression. The model was used to provide insights into the effect of 5-HT4 activation on working memory and to prospectively simulate the response of PF- 04995274, a 5-HT4partial agonist, in a scopolamine-reversal trial in healthy human subjects. Results: The model output suggested a beneficial effect of 5-HT4 agonism on working memory. The model also projected no effect or an exacerbation of scopolamine impairment for low in- trinsic activity 5-HT4agonists, which was supported by the subsequent human trial outcome. The clinical prediction of the disease model strongly suggests that 5-HT4 agonists with high intrinsic activity may have a beneficial effect on cognition in AD patients.
基金Key Research and Development Program of Shaanxi Province(2021SF-288)Natural Science Basic Research Program of Shaanxi Province(2020JQ-950,2022JM-570)+1 种基金Health Research Program of Shaanxi Province(2022D002)Incubation Fund of Shaanxi Provincial People’s Hospital(2018YXQ-07)。
文摘Objective:Clinical and laboratory studies have demonstrated that prelimbic(PrL)and serotonin-4(5-HT4)receptors may have the key role in regulating anxiety.However,the pathophysiology of anxiety in Parkinson’s disease(PD)remains obscure.In this research,the effects of PrL 5-HT4 receptors on anti-anxiety behaviors in hemiparkinsonian rats were investigated.Methods:PD model rats were used as the research subjects,starting with behavioral changes,from the point of view of electrophysiology,the regulatory effect of PrL 5-HT4 receptors on PD-related anxiety and the possible mechanism were explored.Results:Anxiety-like behaviors were induced via MFB lesion in rats.Intra-PrL injection of 5-HT4 receptors agonist RS67333 induced anti-anxiety effects in both sham and PD group.In the sham group,PrL administration of 5-HT4 receptors antagonist SB204070 produce anti-anxiety effects,but in the PD group,the expression of anxiety-like behavior was increased.Compared to the sham group,the effective dose of the behavioral effects of the two drugs in the PD group was obviously higher.Electrophysiological data suggested that PrL administration of RS67333(SB204070)increased(decreased)the firing activities ofγ-aminobutyric acid(GABA)neurons in both groups.Compared with rats in sham group,lesioned rats had a shorter duration of the excitation(inhibition)effects on firing activities of GABA neurons.Conclusion:PrL 5-HT4 receptors regulate anxiety behaviors in PD rats,and its mechanism may be related to the down-regulation of expression or function of PrL 5-HT4 receptors in PD.
基金supported by the National Natural Science Foundation of China(Nos.81971943,81772196,31470264,81271820,30870789,and 30300117)the Stanley Foundation from the Stanley Medical Research Institute(SMRI),United States(No.06R-1366)We acknowledge the Medicine Research Center for Structural Biology of Wuhan University for providing the confocal microscopy(Leica-LCS-SP8-STED).
文摘The human endogenous retroviruses type W family envelope(HERV-W env)gene is located on chromosome 7q21-22.Our previous studies show that HERV-W env is elevated in schizophrenia and HERV-W env can increase cal-cium influx.Additionally,the 5-HTergie system and particularly 5-hydroxytryptamine(5-HT)receptors play a prominent role in the pathogenesis and treatment of schizophrenia.5-hydroxytryptamine receptor 4(5-HT4R)agonist can block calcium channels.However,the underlying relationship between HERV-W env and 5-HT4R in the etiology of schizophrenia has not been revealed.Here,we used enzyme-linked immunosorbent assay to detect the concentration of HERV-W env and 5-HT4R in the plasma of patients with schizophrenia and we found that there were decreased levels of 5-HT4R and a negative correlation between 5-HT4R and HERV-W env in schizophrenia.Overexpression of HERV-W env decreased the transcription and protein levels of 5-HT4R but increased small conductance Ca^(2+)-activated K^(+)type 2 channels(SK2)expression levels.Further studies revealed that HERV-w env could interact with 5-HT4R.Additionally,luciferase assay showed that an essential region(-364 to-176 from the transcription start site)in the SK2 promoter was required for HERV-W env-induced SK2 expression.Importantly,5-HT4R participated in the regulation of SK2 expression and promoter activity.Electrophysiological recordings suggested that HERV-Wenv could increase SK2 channel currents and the increase of SK2 currents was inhibited by 5-HT4R.In condusion,HERV-W env could activate SK2 channels via decreased 5-HT4R,which might exhibit a novel mechanism for HERV-Wenv to influence neuronal activity in schizophrenia.
