This minireview explores the role of acetylcholine and muscarinic receptors in the pathophysiology of schizophrenia and summarizes the latest data on xanomeline/trospium chloride,a novel antipsychotic approved by the ...This minireview explores the role of acetylcholine and muscarinic receptors in the pathophysiology of schizophrenia and summarizes the latest data on xanomeline/trospium chloride,a novel antipsychotic approved by the United States Food and Drug Administration in September 2024.Evidence suggests that cholinergic dysfunction,particularly an imbalance in the expression of the M1 and M4 muscarinic receptors,may contribute to the pathophysiology and symptoms of schizophrenia.Xanomeline/trospium chloride combines xanomeline,an M1 and M4 receptor agonist,with trospium chloride,a non-selective peripheral muscarinic receptor antagonist that reduces peripheral cholinergic side effects.Clinical trials have demonstrated significant reductions in the positive and negative symptoms of schizophrenia,with improvements in Positive and Negati-ve Syndrome Scale scores observed as early as two weeks.A post-hoc analysis of one trial revealed cognitive improvements in patients with baseline cognitive impairment.This medication was generally well-tolerated,with mild-to-moderate gastrointestinal symptoms being the most common adverse events.While these results are promising,further research is needed to better understand its effectiveness and safety in real-world clinical practice,and to define its optimal role in managing this complex psychiatric disorder.展开更多
Objective To investigate the effect of M5 muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it＇s effect on the FosB expression in the nucleus accumbens （NAc） and the hippocam...Objective To investigate the effect of M5 muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it＇s effect on the FosB expression in the nucleus accumbens （NAc） and the hippocampus in the heroin sensitized rats. Methods Locomotor activity was measured every 10 min for 1 h after subcutaneous injection of heroin. FosB expression was assayed by immunohistochemistry, and the antisense oligonucleotides （AS-ONs） targeting M5 muscarinic receptor was transferred with the lipofectin. Results Microinjection of AS-ONs targeting M5 muscarinic receptor in the ventral tegmental area （VTA） blocked the expression of behavioral sensitization induced by heroin priming in rats. Meanwhile, the expression of FosB-positive neurons in either the NAc or the dentate gyrus （DG） of the hippocam- pus increased in heroin-induced locomotor sensitized rats. The enhancement of FosB-positive neurons in the NAc or DG could be inhibited by microinjection of M5 muscarinic receptor AS-ONs into the VTA before the heroin-induced locomotor sensitization was performed. In contrast, microinjection of M5 muscarinic receptor sense oligonucleotide （S-ONs） into the VTA did not block the expression of behavioral sensitization or the expression of FosB in the NAc or DG in the heroin sensitized rats. Conclusion Blocking M5 muscarinic receptor in the VTA inhibits the expression of heroin-induced locomotor sensitization, which is associated with the regulation of FosB expression in the NAc and hippocampus neurons. M5 muscarinic receptor may be a useful pharmacological target for the treatment of heroin addiction.展开更多
In order to compare the potential selectivity of R-（-）-DM-phencynonate hydrochloride with its racemate （±）-DM- phencynonate hydrochloride on acetylcholine muscarinic receptor subtypes, the five human acetylch...In order to compare the potential selectivity of R-（-）-DM-phencynonate hydrochloride with its racemate （±）-DM- phencynonate hydrochloride on acetylcholine muscarinic receptor subtypes, the five human acetylcholine muscarinic receptor subtypes （M1- M5） （CHO-hml-5R） were cloned and expressed in Chinese hamster ovary （CHO-K1） cell line. The specific mRNAs of the five acetylcholine muscarinic receptor subtypes were detected by the reverse transcription-polymerase chain reaction （RT-PCR） method, demonstrating the definite expression of muscarinic receptor subtype genes （CHO-hml-5R）. The affinity and saturability of different muscarinic receptor subtypes to [^3H] N-methylscopolamine （[^3H]-NMS） were obtained by radioligand binding assay. Equilibrium binding assay revealed that the maximum binding capacity of [^3H]-NMS （Bmax value） to CHO-hml-5R were 40.22±3.23, 24.53±4.11, 29.65±2.65, 25.41±2.46, 32.78±4.81 pmol/mg·protein, respectively. Kd values of [^3H]-NMS to muscarinic receptors M1 to M5 were 0.97±0.22, 1.16±0.14, 0.99±0.06, 0.56±0.08, 1.12±0.06 nM, respectively. R-（-）-DM- phencynonate hydrochloride was found to block the M4 receptor with a much higher potency （pD2 = 7.48） than those displayed on M1 （pD2 = 6.20）, M2 （pD2 = 5.99）, M3 （pD2 = 5.99） and M5 （pD2 = 6.70） subtypes. However, for （±）-DM-phencynonate hydrochloride, no significant subtype receptor selectivity was found. Both （±）-DM- and R-（-）-DM-phencynonate hydrochloride showed allosteric effects on muscarinic receptors, the Hill coefficient （nH） of five receptor subtypes was less than 1, respectively. The results revealed that R-（-）-DM-phencynonate hydrochloride showed selectivity torwards M4 subtype, and there were allosteric effects for both R-（-）-DM-phencynonate hydrochloride and （±）-DM-phencynonate hydrochloride on muscarinic receptors.展开更多
The degeneration of cholinergic neurons and cholinergic hypofunction are pathologies associated with Alzheimer＇s disease （AD）. Muscarinic acetylcholine receptors （mAChRs） mediate acetylcholine-induced neurotransm...The degeneration of cholinergic neurons and cholinergic hypofunction are pathologies associated with Alzheimer＇s disease （AD）. Muscarinic acetylcholine receptors （mAChRs） mediate acetylcholine-induced neurotransmission and five mAChR subtypes （M1-M5） have been identified. Among them, M1 mAChR is widely expressed in the central nervous system and has been implicated in many physiological and pathological brain functions. In addition, M1 mAChR is postulated to be an important therapeutic target for AD and several other neurodegenerative diseases. In this article, we review recent progress in understanding the functional involvement of M1 mAChR in AD pathology and in developing M1 mAChR agonists forAD treatment.展开更多
The autonomic nervous system contributes to prostate cancer proliferation and metastasis. However, the exact molecular mechanism remains unclear. In this study, muscarinic acetylcholine receptor M1 （CHRM1） expressio...The autonomic nervous system contributes to prostate cancer proliferation and metastasis. However, the exact molecular mechanism remains unclear. In this study, muscarinic acetylcholine receptor M1 （CHRM1） expression was measured via immunohistochemical analysis in human prostate cancer tissue array slides. PC-3, LNCaP, and A549 cells were treated with pirenzepine or carbachol, and the cell migration and invasion abilities were evaluated. Western blotting and quantitative real-time PCR were performed to measure GLI family zinc finger 1 （GLI1）, patched 1 （PTCH1）, and sonic hedgehog （SHH） expression levels. High expression of CHRM1 was found in early-stage human prostate cancer tissues. In addition, the selective CHRM1 antagonist pirenzepine inhibited PC-3, LNCaP, and A549 cell migration and invasion, but the agonist carbachol promoted the migration and invasion of these three cell lines. Muscarinic signaling can be relayed by hedgehog signaling. These data show that CHRM1 is involved in the regulation of prostate cancer migration and invasion through the hed^eho~ si^nalin~ ~athwav.展开更多
This paper is aimed to study the effect of ADL on expression of ~z-AR and Mz-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect t...This paper is aimed to study the effect of ADL on expression of ~z-AR and Mz-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect the expression of ~I-AR and Mz-AchR in myocardial cells at 7 and 14 d after microwave exposure. The results show that the expression level was higher in microwave exposure group and 0.75 g/（kg.d） ADL group than in sham operation group and significantly lower in 1.5 and 3.0 g/（kg.d） ADL groups than in microwave group. So we have a conclusion that the expression of I^z-AR and Mz-AchR is down-regulated in myocardial cells of rats exposed to microwave radiation. ADL can protect rats against microwave-induced heart tissue injury.展开更多
Objective:To evaluate pharmacological mimetic action of herbal extract Desmodium gangeticum (DC) roots on ischemia reperfusion injury.Methods:With the help of Langendroff perfusion technique,ischemic post condition(PO...Objective:To evaluate pharmacological mimetic action of herbal extract Desmodium gangeticum (DC) roots on ischemia reperfusion injury.Methods:With the help of Langendroff perfusion technique,ischemic post condition(POC) mimetic action of DG methanol root extract was evaluated and compared by using standard drugs that acts as muscarinic receptor agonist and antagonist,namely acetylcholine(Ach) and atropine(Atr) respectively in an isolated rat heart. Results:The physiological parameters like left ventricular developed pressure,end diastolic pressure and working index of isolated rat heart showed significant recovery in DG root extract administrated rat heart,similar to the recovery by POC.Kymogram results showed muscarinic receptor agonist like action for DG methanol root extract,confirmed in rat heart by muscarnic receptor agonist(acetylcholine) and anatoginst(atropine).Administration of DC root extract prior to reperfusion showed better antioxidant status in myocardial tissue homogenate and mitochondrial,complemented by the levels of cardiac specific marker proteins in myocardial tissue and perfusate.Even though DG methanol root extract mimics its action similar to that of Ach,the myocardial protection mediated by the extract was superior to Ach,due to the presence of antioxidants in the crude extract.Conclusions:DG methanol root extract provides myocardial protection towards IRI by stimulating muscarinic receptors.展开更多
AIM： To investigate the effects of green flickering light on refractive development and expression of muscarinic acetylcholine receptor（mAChR） M1 in the eyes of guinea pigs.METHODS： Thirty guinea pigs（15-20 days ...AIM： To investigate the effects of green flickering light on refractive development and expression of muscarinic acetylcholine receptor（mAChR） M1 in the eyes of guinea pigs.METHODS： Thirty guinea pigs（15-20 days old） were randomly divided into three groups（n=10/group）. Animals in group I were raised in a completely closed carton with green flickering light illumination. Those in group II were kept in the open top closed carton under normal natural light. Guinea pigs were raised in a sight-widen cage under normal natural light in group III. The refractive status and axial length were measured before and after 8 weeks＇ illumination. Moreover, total RNA extracted from retinal, choroidal, and scleral tissues were determined by real-time reverse transcription polymerase chain reaction（RT-PCR）. The expressions of the receptor M1 were also explored in the retina, choroid, and sclera using immunohistochemistry.RESULTS： There was a remarkable reduction in refractive error and increase in axial length after 8-weeks＇ green flickering light stimulation（P〈0.001）. The expression of M1 receptor mRNA in sclera and retina in myopia group were remarkably lower than that in group II and III（P〈0.01）. Significant reduced expression of M1 receptor stimulated by green flickering light in retina and sclera tissues were also observed（P〈0.05）. However, there was no M1 receptor expression in choroid in 3 groups.CONCLUSION： Myopia can be induced by 8 weeks＇ green flickering light exposure in the animal model. M1 receptor may be involved causally or protectively in myopia development.展开更多
Besides the mainstay of α-blockers and 5α-reductase inhibitors,other forms of medical therapy complete the armamentarium in the treatment of lower urinary tract symptoms(LUTS)in men.These treatments can target speci...Besides the mainstay of α-blockers and 5α-reductase inhibitors,other forms of medical therapy complete the armamentarium in the treatment of lower urinary tract symptoms(LUTS)in men.These treatments can target specific symptoms as well as associated symptoms that would affect the quality of life of the patients.Many patients are bothered by storage symptoms,more so than the voiding symptoms.Antimuscarinics are efficacious and safe,provided the patients do not have high post void residual urine.Many patients with LUTS also have erectile dysfunction,and phosphodiesterase type Ⅴ inhibitors are effective in relieving both LUTS as well as erectile dysfunction for such patients.Phytotherapy provides a popular and safe treatment for LUTS,however,the efficacy of the treatment has not been proven in well conducted prospective randomized controlled studies.展开更多
The muscarinic receptor modulates intracellular free calcium ion levels in the facial nerve nucleus via different channels. In the present study, muscarinic receptor-mediated free calcium ions levels were detected by ...The muscarinic receptor modulates intracellular free calcium ion levels in the facial nerve nucleus via different channels. In the present study, muscarinic receptor-mediated free calcium ions levels were detected by confocal laser microscopy in the facial nerve nucleus following facial nerve injury in rats. There was no significant difference in muscarinic receptor expression at the affected facial nerve nucleus compared with expression prior to injury, but muscarinic receptor-mediated free calcium ion levels increased in the affected side following facial nerve injury （P 〈 0.01）. At day 30 after facial nerve injury, 50 pmol/L muscarinic-mediated free calcium ion levels were significantly inhibited at the affected facial nerve nucleus in calcium-free artificial cerebrospinal fluid, and the change range was 82% of artificial cerebrospinal fluid （P 〈 0.05）. These results suggest that increased free calcium ion concentrations are achieved by intracellular calcium ion release, and that the transmembrane flow of calcium ions is also involved in this process.展开更多
Idiopathic pulmonary fibrosis is an untreatable lethal lung disease, which is related to the aberrant proliferation of fibroblasts. M<sub>3</sub> muscarinic acetylcholine receptor (M<sub>3</sub>...Idiopathic pulmonary fibrosis is an untreatable lethal lung disease, which is related to the aberrant proliferation of fibroblasts. M<sub>3</sub> muscarinic acetylcholine receptor (M<sub>3</sub>-mAChR) activation exerts proliferative effect on various kinds of cells. However, whether M<sub>3</sub>-mAChR inhibition has a protective effect on pulmonary fibrosis remains unexplored. A rat model of pulmonary fibrosis was established by intratracheal instillation of bleomycin. Darifenacin was used to block M<sub>3</sub>-mAChR. Histological changes were observed using Masson’s Trichrome and hematoxylin and eosin (HE) staining. Hydroxyproline was measured by Hydroxyproline detection kit. Transforming growth factor β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay (ELISA). In vitro, pulmonary fibroblasts were isolated from lungs of neonatal rat. After treatment, the cell viability, Hydroxyproline level was measured by MTT and Hydroxyproline detection kit respectively. The expression level of extracellular signal-regulated kinase (ERK), nuclear factor kappa-B (N-NF-κB), and microRNA-21 (miR-21) was detected by western blot or quantitative real-time PCR (qRT-PCR). Darifenacin relieved the fibrotic effects provoked by bleomycin. The expression level of hydroxyproline, TGF-β1 and TNF-α level was all downregulated after darifenacin treatment. In lung fibroblasts, darifenacin decreased cell viability and hydroxyproline level induced by bleomycin. Besides, phosphorylation-ERK and nuclear N-NF-κB protein level was downregulated, as well as miR-21 level. M<sub>3</sub>-mAChR antagonist darifenacin attenuates bleomycin-induced pulmonary fibrosis in rats, which may relate to the ERK/NF-κB/miRNA-21 signaling pathway.展开更多
A technique for studying in vivo the production rate and turnover rate constant of mouse brain M-receptors was established. A single injection of 25 mg / kg of Benzilylcholine Mustard to living mice resulted in 90 % i...A technique for studying in vivo the production rate and turnover rate constant of mouse brain M-receptors was established. A single injection of 25 mg / kg of Benzilylcholine Mustard to living mice resulted in 90 % irreversible block of brain M-receptors. The time course of the receptor density was then monitored by 3H-QNB binding assay and the production rate and turnover rate constant were calculated from the time course curve with a computer program. It was found that in normal mice the turnover rate constant was about 0.035 h-1 (half-life was about 20 h) and the production rate was 30-42 fmol / (h ·mg protein). Parallel experiments revealed a significant slow down of the turnover of brain M-receptors in hypothyroid mice (turnover rate constant was 0.0257±0.0012 h-1 in hypothyroid vs. 0.0356±0.0021 h-1 in normal) while the production rate was not changed significantly. The results suggest that thyroid hormones have a regulatory action on the turnover of brain M-receptors and the elevation of brain M-receptor density together with slow down of the turnover of brain M- receptors is probably one of the important mechanisms relevant to the brain dysfunction in hypothyroidism.展开更多
Amino-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thiol 1 were condensed with 2-bromo-1- (substituted phenyl)ethanone to give pyridinyltriazolothiadiazines 2a^c, which were quaternarized with methyl iodide and oxidized wit...Amino-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thiol 1 were condensed with 2-bromo-1- (substituted phenyl)ethanone to give pyridinyltriazolothiadiazines 2a^c, which were quaternarized with methyl iodide and oxidized with 30 % hydrogen peroxide to afford the corresponding methyl pyridinium salts 3a^c and pyridine-1-oxides 4a^c, respectively. The reduction of compounds 3 and 4 with NaBH4 in methanol produced the target compounds 1-methyl-1, 2, 5, 6-tetrahydropyridin-3- yl)-6-aryl-s-triazolothiadiazines 5a^c and 3-(1-hydroxyl-1, 2, 5, 6-tetrahydropyridin -3-yl)-6-aryl- s-triazolothiadiazines 6a^c, respectively. The endothelium vascular relaxing activity of the target compounds was screened.展开更多
Objective:To investigate the pharmacological potential of Argemone mexicana in treating constipation and emesis by using in vitro and in vivo models.Methods:The spasmogenic and spasmolytic effects were evaluated on is...Objective:To investigate the pharmacological potential of Argemone mexicana in treating constipation and emesis by using in vitro and in vivo models.Methods:The spasmogenic and spasmolytic effects were evaluated on isolated rabbit jejunum fragments loaded in a tissue organ bath.The response was recorded with an isotonic transducer attached with Power Lab Data Acquisition System.The laxative and antiemetic activities were assessed in BALB-c mice and poultry chicks challenged with carbamylcholine and copper sulphate stimulated emesis,respectively.Results:The total phenolic and total flavonoids contents of the extract were(267.75±5.77)mg GAE/g and(73.86±6.01)mg QE/g,respectively.Argemone mexicana extract exerted spasmogenic effect on isolated rabbit jejunum segments with an EC_(50)value of 0.016 mg/m L,which was blocked by atropine(0.3μM).Argemone mexicana extract exerted spasmolytic effect in atropine treated jejunum fragments with an EC_(50)value of 2.185 mg/mL.Furthermore,Argemone mexicana extract relaxed potassium(80 mM)-induced contractions(EC_(50):9.07 mg/mL),similar to a standard drug verapamil.The calcium channel blocker activity was confirmed by a rightward shift of concentration-response curve of calcium in the presence of Argemone mexicana extract(1-5 mg/mL)and verapamil(0.1-1μM).In addition,the extract increased the distance travelled by a charcoal in the gastrointestinal tract and exhibited antiemetic effect on copper sulphate induced emesis in chicks.Conclusions:Argemone mexicana shows cholinergic agonist and calcium channel blocker activities,as well as antiemetic effect.It may be used as a potential agent for treating gastrointestinal disorders.展开更多
Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have...Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.展开更多
BACKGROUND： It has been previously shown that the muscarinic （M） receptor is involved in brain arousal and selective attention, mood, and motor coordination. OBJECTIVE： To explore the effects of various intragastr...BACKGROUND： It has been previously shown that the muscarinic （M） receptor is involved in brain arousal and selective attention, mood, and motor coordination. OBJECTIVE： To explore the effects of various intragastric Daicong doses on hippocampal MI and M3 receptor gene expression in a rat model of Alzheimer＇s disease. DESIGN, TIME AND SETTING： A randomized cellular and molecular biology experiment, conducted at the Molecular Immunology Laboratory in Shandong between October 2006 and April 2007. MATERIALS： Fifty 22-month old Sprague Dawley rats, weighing 250-300 g were used for this experiment. Kainic acid was used to lesion the nucleus basalis to establish a rat model of Alzheimer＇s disease. The components of Daicong solution were as follows： ginseng, rehmannia dride rhizome, anemarrhena, and radix astragali. The solution was provided by the Affiliated Hospital to Weifang Medical College, according to preparation techniques of extracting liquid for traditional Chinese medicine （1 g crude drug/mL solution）. Kainic acid was provided by Professor Xiuyan Li at Weifang Medical College. METHODS： The rats were randomly divided into 5 groups, 10 rats in each group. Four groups were used for model establishment, and the fifth group served as a normal control group. Three of the model groups were intragastrically administered 5, 10, and 20 g/kg/d Daicong solution, and an additional model group and normal control group received normal saline （10 mL/kg/d）. Drugs were administered over a time period of one month. MAIN OUTCOME MEASURES： Four days after model establishment, Morris water maze was used to measure learning and memory capabilities. RT-PCR was used to detect the effect of Daicong solution on mRNA expression of M1 and M3 receptor in the hippocampus of all groups. RESULTS： Fifty rats were included in the final analysis, without any loss. M1 and M3 receptor mRNA expression was decreased in the model group, compared to the normal control group （P 〈 0.05）. Upon Daicong administration （10 g/kg/d and 20 g/kg/d）, M1 and M3 receptor mRNA expression significantly increased in the hippocampus, compared to the model group （P 〈 0.05）. M1 and M3 mRNA expression was greatest in the 10 g/kg/d group. CONCLUSION： A 10 g/kg/d solution of Daicong can improve M1 and M3 receptor mRNA expression in the hippocampus of a rat model of Alzheimer＇s disease.展开更多
Background:Anisodine hydrobromide(AT3),an anti-cholinergic agent,could be delivered to the brain across the blood-brain barrier and has been used clinically for the treatment of cerebral ischemia/reperfusion injury.En...Background:Anisodine hydrobromide(AT3),an anti-cholinergic agent,could be delivered to the brain across the blood-brain barrier and has been used clinically for the treatment of cerebral ischemia/reperfusion injury.Endothelial dysfunction can be caused by hypoxia/reoxygenation(H/R)via oxidative stress and metabolic alterations.The present study investigated whether AT3 regulates the production of nitric oxide(NO)and reactive oxygen species(ROS),and the HIF-1αpathway via regulation of muscarinic acetylcholine receptors(mAChRs)in brain microvascular endothelial cells after H/R exposure.Methods:Under H/R conditions,hCMEC/D3 cerebral microvascular endothelial cells were treated with AT3.Specific inhibitors of M2-and M4-mAChRs were used to explore the mechanism by which AT3 influences oxidative stress in endothelial cells.Then,mAChRs expression was detected by western blotting and NO production was detected by Greiss reaction.The intracellular ROS level was measured using DCFH-DA probes.The expression of hypoxia-inducible transcription factor 1α(HIF-1α)was also detected.Results:While H/R induced the expression of M2-and M4-mAChRs,AT3 suppressed the H/R-upregulated M2-and M4-mAChRs.H/R also induced the production of NO,ROS,and apoptosis.AT3 and M4-mAChR inhibitors inhibited the H/R-induced production of NO and ROS and apoptosis.HIF-1αwas induced by H/R,but was suppressed by AT3.Conclusion:Thus,the in vitro evidence shows that AT3 protects against H/R injury in cerebral microvascular endothelial cells via inhibition of HIF-1α,NO and ROS,predominantly through the downregulation of M4-mAChR.The findings offer novel understandings regarding AT3-mediated attenuation of endothelial cell apoptosis and cerebral ischemia/reperfusion injury.展开更多
OBJECTIVE Abnormal striatal dopaminergic and glutamatergic neurotransmis⁃sion is central to the pathophysiology of schizo⁃phrenia.In this study,we investigated the roles of M4 receptor interplay with D1 signaling in s...OBJECTIVE Abnormal striatal dopaminergic and glutamatergic neurotransmis⁃sion is central to the pathophysiology of schizo⁃phrenia.In this study,we investigated the roles of M4 receptor interplay with D1 signaling in stria⁃tal neurotransmission that affect glutamatergic transmission to control the etiology of neuropsy⁃chiatric disorders.METHODS To study dorsal striatum(DS)region-specific neuronal and behav⁃ioral responses modulated by M4 receptors,we used clustered regularly interspaced short palin⁃dromic repeats-associated protein 9 technology to generate mice lacking M4 in the dorsal stria⁃tum(DS-M4-KD).The M4 positive allosteric modu⁃lator,VU0467154,were used to study the phar⁃macologically profiles with M4 receptor stimula⁃tion in WT mice.Oxotremorine M(Oxo-M),a no subtype-selective muscarinic agonist,was used to show that mAchRs activation,in order to dissect the particular function of M4,in DS-M4-KD mice.Open filed test and forced swim test were used to assess the change of psychiatric-like behav⁃iors.Western blotting and immunohistochemistry were used to detect protein levels of phosphory⁃lation site of dopamine-and cAMP-regulated phosphoprotein of 32 ku(DARPP-32).Whole-cell patch-clamp recording was used to assess M4-mediated cholinergic inhibition of glutamater⁃gic synaptic input transmission.RESULTS West⁃ern blotting and immunohistochemistry assay showed VU0467154(5 mg·kg-1,ip)promoted phosphorylation of DARPP-32 at Thr75,and atten⁃uated D1-dependent phosphorylation of DARPP-32 at Thr34 within the mouse DS.Consistently,the Oxo-M(4μg,icv)also increased DARPP-32 phosphorylation at site Thr75 to reversed phos⁃phorylation at site Thr34 in WT mice,but not in DS-M4-KD mice.In parallel with altered DARPP-32 responses,VU0467154 or Oxo-M evoked a psychological stress response and reversed D1-induced hyperlocomotion in mice in open field test and force swim tests.However,Oxo-M sup⁃pression of D1-depengdeng behavioral respons⁃es was impaired in DS-M4-KD mice.Whole-cell patch recording showed that VU0467154 or Oxo-M mediated endogenous cholinergic inhibition of miniature excitatory postsynaptic currents through M4 receptors,which in turn suppressed D1-depen⁃dent glutamatergic synaptic transmission in the DS.CONCLUSION This study provides evidence for the role of M4 receptors in regulation of dopa⁃mine/DARPP-32 signaling and glutamate respons⁃es in the DS,and therefore modulation of psychi⁃atric behaviors associated with D1 signaling.This results indicate the mechanisms of treatments targeting M4 in psychiatric disorders.展开更多
The development of breast cancer is a complex process that involves the participation of different factors.Several authors have demonstrated the overexpression of muscarinic acetylcholine receptors(mAChRs)in different...The development of breast cancer is a complex process that involves the participation of different factors.Several authors have demonstrated the overexpression of muscarinic acetylcholine receptors(mAChRs)in different tumor tissues and their role in the modulation of tumor biology,positioning them as therapeutic targets in cancer.The conventional treatment for breast cancer involves surgery,radiotherapy,and/or chemotherapy.The latter presents disadvantages such as limited specificity,the appearance of resistance to treatment and other side effects.To prevent these side effects,several schedules of drug administration,like metronomic therapy,have been developed.Metronomic therapy is a type of chemotherapy in which one or more drugs are administered at low concentrations repetitively.Recently,two chemotherapeutic agents usually used to treat breast cancer have been considered able to activate mAChRs.The combination of low concentrations of these chemotherapeutic agents with muscarinic agonists could be a useful option to be applied in breast cancer treatment,since this combination not only reduces tumor cell survival without affecting normal cells,but also decreases pathological neo-angiogenesis,the expression of drug extrusion proteins and the cancer stem cell fraction.In this review,we focus on the previous evidences that have positioned mAChRs as relevant therapeutic targets in breast cancer and analyze the effects of administering muscarinic agonists in combination with conventional chemotherapeutic agents in a metronomic schedule.展开更多
文摘This minireview explores the role of acetylcholine and muscarinic receptors in the pathophysiology of schizophrenia and summarizes the latest data on xanomeline/trospium chloride,a novel antipsychotic approved by the United States Food and Drug Administration in September 2024.Evidence suggests that cholinergic dysfunction,particularly an imbalance in the expression of the M1 and M4 muscarinic receptors,may contribute to the pathophysiology and symptoms of schizophrenia.Xanomeline/trospium chloride combines xanomeline,an M1 and M4 receptor agonist,with trospium chloride,a non-selective peripheral muscarinic receptor antagonist that reduces peripheral cholinergic side effects.Clinical trials have demonstrated significant reductions in the positive and negative symptoms of schizophrenia,with improvements in Positive and Negati-ve Syndrome Scale scores observed as early as two weeks.A post-hoc analysis of one trial revealed cognitive improvements in patients with baseline cognitive impairment.This medication was generally well-tolerated,with mild-to-moderate gastrointestinal symptoms being the most common adverse events.While these results are promising,further research is needed to better understand its effectiveness and safety in real-world clinical practice,and to define its optimal role in managing this complex psychiatric disorder.
基金This work was supported by the National Nature Science Foundation of China （No.30470554）the National Basic Research Development Program of China（No.2003CB515404）.
文摘Objective To investigate the effect of M5 muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it＇s effect on the FosB expression in the nucleus accumbens （NAc） and the hippocampus in the heroin sensitized rats. Methods Locomotor activity was measured every 10 min for 1 h after subcutaneous injection of heroin. FosB expression was assayed by immunohistochemistry, and the antisense oligonucleotides （AS-ONs） targeting M5 muscarinic receptor was transferred with the lipofectin. Results Microinjection of AS-ONs targeting M5 muscarinic receptor in the ventral tegmental area （VTA） blocked the expression of behavioral sensitization induced by heroin priming in rats. Meanwhile, the expression of FosB-positive neurons in either the NAc or the dentate gyrus （DG） of the hippocam- pus increased in heroin-induced locomotor sensitized rats. The enhancement of FosB-positive neurons in the NAc or DG could be inhibited by microinjection of M5 muscarinic receptor AS-ONs into the VTA before the heroin-induced locomotor sensitization was performed. In contrast, microinjection of M5 muscarinic receptor sense oligonucleotide （S-ONs） into the VTA did not block the expression of behavioral sensitization or the expression of FosB in the NAc or DG in the heroin sensitized rats. Conclusion Blocking M5 muscarinic receptor in the VTA inhibits the expression of heroin-induced locomotor sensitization, which is associated with the regulation of FosB expression in the NAc and hippocampus neurons. M5 muscarinic receptor may be a useful pharmacological target for the treatment of heroin addiction.
基金National Natural Science Foundation of China (Grant No. 30672445)
文摘In order to compare the potential selectivity of R-（-）-DM-phencynonate hydrochloride with its racemate （±）-DM- phencynonate hydrochloride on acetylcholine muscarinic receptor subtypes, the five human acetylcholine muscarinic receptor subtypes （M1- M5） （CHO-hml-5R） were cloned and expressed in Chinese hamster ovary （CHO-K1） cell line. The specific mRNAs of the five acetylcholine muscarinic receptor subtypes were detected by the reverse transcription-polymerase chain reaction （RT-PCR） method, demonstrating the definite expression of muscarinic receptor subtype genes （CHO-hml-5R）. The affinity and saturability of different muscarinic receptor subtypes to [^3H] N-methylscopolamine （[^3H]-NMS） were obtained by radioligand binding assay. Equilibrium binding assay revealed that the maximum binding capacity of [^3H]-NMS （Bmax value） to CHO-hml-5R were 40.22±3.23, 24.53±4.11, 29.65±2.65, 25.41±2.46, 32.78±4.81 pmol/mg·protein, respectively. Kd values of [^3H]-NMS to muscarinic receptors M1 to M5 were 0.97±0.22, 1.16±0.14, 0.99±0.06, 0.56±0.08, 1.12±0.06 nM, respectively. R-（-）-DM- phencynonate hydrochloride was found to block the M4 receptor with a much higher potency （pD2 = 7.48） than those displayed on M1 （pD2 = 6.20）, M2 （pD2 = 5.99）, M3 （pD2 = 5.99） and M5 （pD2 = 6.70） subtypes. However, for （±）-DM-phencynonate hydrochloride, no significant subtype receptor selectivity was found. Both （±）-DM- and R-（-）-DM-phencynonate hydrochloride showed allosteric effects on muscarinic receptors, the Hill coefficient （nH） of five receptor subtypes was less than 1, respectively. The results revealed that R-（-）-DM-phencynonate hydrochloride showed selectivity torwards M4 subtype, and there were allosteric effects for both R-（-）-DM-phencynonate hydrochloride and （±）-DM-phencynonate hydrochloride on muscarinic receptors.
基金supported by grants from the National Institutes of Health,USA(R01AG038710,R01AG021173,R01AG044420 and R01NS046673)the Alzheimer’s Association,the National Natural Science Foundation of China(91332112,81225008 and 81161120496)+1 种基金Fundamental Research Funds for the Central Universities of Chinathe Fok Ying Tung Education Foundation
文摘The degeneration of cholinergic neurons and cholinergic hypofunction are pathologies associated with Alzheimer＇s disease （AD）. Muscarinic acetylcholine receptors （mAChRs） mediate acetylcholine-induced neurotransmission and five mAChR subtypes （M1-M5） have been identified. Among them, M1 mAChR is widely expressed in the central nervous system and has been implicated in many physiological and pathological brain functions. In addition, M1 mAChR is postulated to be an important therapeutic target for AD and several other neurodegenerative diseases. In this article, we review recent progress in understanding the functional involvement of M1 mAChR in AD pathology and in developing M1 mAChR agonists forAD treatment.
基金Tnis workwas supportedby the Natural Science Foundation of Chongqing （CSTC, 2009BA5081）.
文摘The autonomic nervous system contributes to prostate cancer proliferation and metastasis. However, the exact molecular mechanism remains unclear. In this study, muscarinic acetylcholine receptor M1 （CHRM1） expression was measured via immunohistochemical analysis in human prostate cancer tissue array slides. PC-3, LNCaP, and A549 cells were treated with pirenzepine or carbachol, and the cell migration and invasion abilities were evaluated. Western blotting and quantitative real-time PCR were performed to measure GLI family zinc finger 1 （GLI1）, patched 1 （PTCH1）, and sonic hedgehog （SHH） expression levels. High expression of CHRM1 was found in early-stage human prostate cancer tissues. In addition, the selective CHRM1 antagonist pirenzepine inhibited PC-3, LNCaP, and A549 cell migration and invasion, but the agonist carbachol promoted the migration and invasion of these three cell lines. Muscarinic signaling can be relayed by hedgehog signaling. These data show that CHRM1 is involved in the regulation of prostate cancer migration and invasion through the hed^eho~ si^nalin~ ~athwav.
文摘This paper is aimed to study the effect of ADL on expression of ~z-AR and Mz-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect the expression of ~I-AR and Mz-AchR in myocardial cells at 7 and 14 d after microwave exposure. The results show that the expression level was higher in microwave exposure group and 0.75 g/（kg.d） ADL group than in sham operation group and significantly lower in 1.5 and 3.0 g/（kg.d） ADL groups than in microwave group. So we have a conclusion that the expression of I^z-AR and Mz-AchR is down-regulated in myocardial cells of rats exposed to microwave radiation. ADL can protect rats against microwave-induced heart tissue injury.
文摘Objective:To evaluate pharmacological mimetic action of herbal extract Desmodium gangeticum (DC) roots on ischemia reperfusion injury.Methods:With the help of Langendroff perfusion technique,ischemic post condition(POC) mimetic action of DG methanol root extract was evaluated and compared by using standard drugs that acts as muscarinic receptor agonist and antagonist,namely acetylcholine(Ach) and atropine(Atr) respectively in an isolated rat heart. Results:The physiological parameters like left ventricular developed pressure,end diastolic pressure and working index of isolated rat heart showed significant recovery in DG root extract administrated rat heart,similar to the recovery by POC.Kymogram results showed muscarinic receptor agonist like action for DG methanol root extract,confirmed in rat heart by muscarnic receptor agonist(acetylcholine) and anatoginst(atropine).Administration of DC root extract prior to reperfusion showed better antioxidant status in myocardial tissue homogenate and mitochondrial,complemented by the levels of cardiac specific marker proteins in myocardial tissue and perfusate.Even though DG methanol root extract mimics its action similar to that of Ach,the myocardial protection mediated by the extract was superior to Ach,due to the presence of antioxidants in the crude extract.Conclusions:DG methanol root extract provides myocardial protection towards IRI by stimulating muscarinic receptors.
基金Supported by Qilu Hospital of Shandong University (No.201805049)
文摘AIM： To investigate the effects of green flickering light on refractive development and expression of muscarinic acetylcholine receptor（mAChR） M1 in the eyes of guinea pigs.METHODS： Thirty guinea pigs（15-20 days old） were randomly divided into three groups（n=10/group）. Animals in group I were raised in a completely closed carton with green flickering light illumination. Those in group II were kept in the open top closed carton under normal natural light. Guinea pigs were raised in a sight-widen cage under normal natural light in group III. The refractive status and axial length were measured before and after 8 weeks＇ illumination. Moreover, total RNA extracted from retinal, choroidal, and scleral tissues were determined by real-time reverse transcription polymerase chain reaction（RT-PCR）. The expressions of the receptor M1 were also explored in the retina, choroid, and sclera using immunohistochemistry.RESULTS： There was a remarkable reduction in refractive error and increase in axial length after 8-weeks＇ green flickering light stimulation（P〈0.001）. The expression of M1 receptor mRNA in sclera and retina in myopia group were remarkably lower than that in group II and III（P〈0.01）. Significant reduced expression of M1 receptor stimulated by green flickering light in retina and sclera tissues were also observed（P〈0.05）. However, there was no M1 receptor expression in choroid in 3 groups.CONCLUSION： Myopia can be induced by 8 weeks＇ green flickering light exposure in the animal model. M1 receptor may be involved causally or protectively in myopia development.
文摘Besides the mainstay of α-blockers and 5α-reductase inhibitors,other forms of medical therapy complete the armamentarium in the treatment of lower urinary tract symptoms(LUTS)in men.These treatments can target specific symptoms as well as associated symptoms that would affect the quality of life of the patients.Many patients are bothered by storage symptoms,more so than the voiding symptoms.Antimuscarinics are efficacious and safe,provided the patients do not have high post void residual urine.Many patients with LUTS also have erectile dysfunction,and phosphodiesterase type Ⅴ inhibitors are effective in relieving both LUTS as well as erectile dysfunction for such patients.Phytotherapy provides a popular and safe treatment for LUTS,however,the efficacy of the treatment has not been proven in well conducted prospective randomized controlled studies.
基金Youth Scientific Research Foundation of Qingdao University (2007)
文摘The muscarinic receptor modulates intracellular free calcium ion levels in the facial nerve nucleus via different channels. In the present study, muscarinic receptor-mediated free calcium ions levels were detected by confocal laser microscopy in the facial nerve nucleus following facial nerve injury in rats. There was no significant difference in muscarinic receptor expression at the affected facial nerve nucleus compared with expression prior to injury, but muscarinic receptor-mediated free calcium ion levels increased in the affected side following facial nerve injury （P 〈 0.01）. At day 30 after facial nerve injury, 50 pmol/L muscarinic-mediated free calcium ion levels were significantly inhibited at the affected facial nerve nucleus in calcium-free artificial cerebrospinal fluid, and the change range was 82% of artificial cerebrospinal fluid （P 〈 0.05）. These results suggest that increased free calcium ion concentrations are achieved by intracellular calcium ion release, and that the transmembrane flow of calcium ions is also involved in this process.
文摘Idiopathic pulmonary fibrosis is an untreatable lethal lung disease, which is related to the aberrant proliferation of fibroblasts. M<sub>3</sub> muscarinic acetylcholine receptor (M<sub>3</sub>-mAChR) activation exerts proliferative effect on various kinds of cells. However, whether M<sub>3</sub>-mAChR inhibition has a protective effect on pulmonary fibrosis remains unexplored. A rat model of pulmonary fibrosis was established by intratracheal instillation of bleomycin. Darifenacin was used to block M<sub>3</sub>-mAChR. Histological changes were observed using Masson’s Trichrome and hematoxylin and eosin (HE) staining. Hydroxyproline was measured by Hydroxyproline detection kit. Transforming growth factor β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay (ELISA). In vitro, pulmonary fibroblasts were isolated from lungs of neonatal rat. After treatment, the cell viability, Hydroxyproline level was measured by MTT and Hydroxyproline detection kit respectively. The expression level of extracellular signal-regulated kinase (ERK), nuclear factor kappa-B (N-NF-κB), and microRNA-21 (miR-21) was detected by western blot or quantitative real-time PCR (qRT-PCR). Darifenacin relieved the fibrotic effects provoked by bleomycin. The expression level of hydroxyproline, TGF-β1 and TNF-α level was all downregulated after darifenacin treatment. In lung fibroblasts, darifenacin decreased cell viability and hydroxyproline level induced by bleomycin. Besides, phosphorylation-ERK and nuclear N-NF-κB protein level was downregulated, as well as miR-21 level. M<sub>3</sub>-mAChR antagonist darifenacin attenuates bleomycin-induced pulmonary fibrosis in rats, which may relate to the ERK/NF-κB/miRNA-21 signaling pathway.
文摘A technique for studying in vivo the production rate and turnover rate constant of mouse brain M-receptors was established. A single injection of 25 mg / kg of Benzilylcholine Mustard to living mice resulted in 90 % irreversible block of brain M-receptors. The time course of the receptor density was then monitored by 3H-QNB binding assay and the production rate and turnover rate constant were calculated from the time course curve with a computer program. It was found that in normal mice the turnover rate constant was about 0.035 h-1 (half-life was about 20 h) and the production rate was 30-42 fmol / (h ·mg protein). Parallel experiments revealed a significant slow down of the turnover of brain M-receptors in hypothyroid mice (turnover rate constant was 0.0257±0.0012 h-1 in hypothyroid vs. 0.0356±0.0021 h-1 in normal) while the production rate was not changed significantly. The results suggest that thyroid hormones have a regulatory action on the turnover of brain M-receptors and the elevation of brain M-receptor density together with slow down of the turnover of brain M- receptors is probably one of the important mechanisms relevant to the brain dysfunction in hypothyroidism.
基金supported by the State Basic Research and Development Project(No.G1998051112)the Science Foundation of Henan University(XK02041)
文摘Amino-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thiol 1 were condensed with 2-bromo-1- (substituted phenyl)ethanone to give pyridinyltriazolothiadiazines 2a^c, which were quaternarized with methyl iodide and oxidized with 30 % hydrogen peroxide to afford the corresponding methyl pyridinium salts 3a^c and pyridine-1-oxides 4a^c, respectively. The reduction of compounds 3 and 4 with NaBH4 in methanol produced the target compounds 1-methyl-1, 2, 5, 6-tetrahydropyridin-3- yl)-6-aryl-s-triazolothiadiazines 5a^c and 3-(1-hydroxyl-1, 2, 5, 6-tetrahydropyridin -3-yl)-6-aryl- s-triazolothiadiazines 6a^c, respectively. The endothelium vascular relaxing activity of the target compounds was screened.
文摘Objective:To investigate the pharmacological potential of Argemone mexicana in treating constipation and emesis by using in vitro and in vivo models.Methods:The spasmogenic and spasmolytic effects were evaluated on isolated rabbit jejunum fragments loaded in a tissue organ bath.The response was recorded with an isotonic transducer attached with Power Lab Data Acquisition System.The laxative and antiemetic activities were assessed in BALB-c mice and poultry chicks challenged with carbamylcholine and copper sulphate stimulated emesis,respectively.Results:The total phenolic and total flavonoids contents of the extract were(267.75±5.77)mg GAE/g and(73.86±6.01)mg QE/g,respectively.Argemone mexicana extract exerted spasmogenic effect on isolated rabbit jejunum segments with an EC_(50)value of 0.016 mg/m L,which was blocked by atropine(0.3μM).Argemone mexicana extract exerted spasmolytic effect in atropine treated jejunum fragments with an EC_(50)value of 2.185 mg/mL.Furthermore,Argemone mexicana extract relaxed potassium(80 mM)-induced contractions(EC_(50):9.07 mg/mL),similar to a standard drug verapamil.The calcium channel blocker activity was confirmed by a rightward shift of concentration-response curve of calcium in the presence of Argemone mexicana extract(1-5 mg/mL)and verapamil(0.1-1μM).In addition,the extract increased the distance travelled by a charcoal in the gastrointestinal tract and exhibited antiemetic effect on copper sulphate induced emesis in chicks.Conclusions:Argemone mexicana shows cholinergic agonist and calcium channel blocker activities,as well as antiemetic effect.It may be used as a potential agent for treating gastrointestinal disorders.
基金the Youth Research Foundation of Qingdao University, No. 2007
文摘Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.
基金the grant from Shandong Administration Bureau of Traditional Chinese Medicine, No.2001-2-75
文摘BACKGROUND： It has been previously shown that the muscarinic （M） receptor is involved in brain arousal and selective attention, mood, and motor coordination. OBJECTIVE： To explore the effects of various intragastric Daicong doses on hippocampal MI and M3 receptor gene expression in a rat model of Alzheimer＇s disease. DESIGN, TIME AND SETTING： A randomized cellular and molecular biology experiment, conducted at the Molecular Immunology Laboratory in Shandong between October 2006 and April 2007. MATERIALS： Fifty 22-month old Sprague Dawley rats, weighing 250-300 g were used for this experiment. Kainic acid was used to lesion the nucleus basalis to establish a rat model of Alzheimer＇s disease. The components of Daicong solution were as follows： ginseng, rehmannia dride rhizome, anemarrhena, and radix astragali. The solution was provided by the Affiliated Hospital to Weifang Medical College, according to preparation techniques of extracting liquid for traditional Chinese medicine （1 g crude drug/mL solution）. Kainic acid was provided by Professor Xiuyan Li at Weifang Medical College. METHODS： The rats were randomly divided into 5 groups, 10 rats in each group. Four groups were used for model establishment, and the fifth group served as a normal control group. Three of the model groups were intragastrically administered 5, 10, and 20 g/kg/d Daicong solution, and an additional model group and normal control group received normal saline （10 mL/kg/d）. Drugs were administered over a time period of one month. MAIN OUTCOME MEASURES： Four days after model establishment, Morris water maze was used to measure learning and memory capabilities. RT-PCR was used to detect the effect of Daicong solution on mRNA expression of M1 and M3 receptor in the hippocampus of all groups. RESULTS： Fifty rats were included in the final analysis, without any loss. M1 and M3 receptor mRNA expression was decreased in the model group, compared to the normal control group （P 〈 0.05）. Upon Daicong administration （10 g/kg/d and 20 g/kg/d）, M1 and M3 receptor mRNA expression significantly increased in the hippocampus, compared to the model group （P 〈 0.05）. M1 and M3 mRNA expression was greatest in the 10 g/kg/d group. CONCLUSION： A 10 g/kg/d solution of Daicong can improve M1 and M3 receptor mRNA expression in the hippocampus of a rat model of Alzheimer＇s disease.
基金funding from the National Natural Science Foundation of China(12272246)the Key Research and Development Projects of Sichuan Province(2023YFS0075).
文摘Background:Anisodine hydrobromide(AT3),an anti-cholinergic agent,could be delivered to the brain across the blood-brain barrier and has been used clinically for the treatment of cerebral ischemia/reperfusion injury.Endothelial dysfunction can be caused by hypoxia/reoxygenation(H/R)via oxidative stress and metabolic alterations.The present study investigated whether AT3 regulates the production of nitric oxide(NO)and reactive oxygen species(ROS),and the HIF-1αpathway via regulation of muscarinic acetylcholine receptors(mAChRs)in brain microvascular endothelial cells after H/R exposure.Methods:Under H/R conditions,hCMEC/D3 cerebral microvascular endothelial cells were treated with AT3.Specific inhibitors of M2-and M4-mAChRs were used to explore the mechanism by which AT3 influences oxidative stress in endothelial cells.Then,mAChRs expression was detected by western blotting and NO production was detected by Greiss reaction.The intracellular ROS level was measured using DCFH-DA probes.The expression of hypoxia-inducible transcription factor 1α(HIF-1α)was also detected.Results:While H/R induced the expression of M2-and M4-mAChRs,AT3 suppressed the H/R-upregulated M2-and M4-mAChRs.H/R also induced the production of NO,ROS,and apoptosis.AT3 and M4-mAChR inhibitors inhibited the H/R-induced production of NO and ROS and apoptosis.HIF-1αwas induced by H/R,but was suppressed by AT3.Conclusion:Thus,the in vitro evidence shows that AT3 protects against H/R injury in cerebral microvascular endothelial cells via inhibition of HIF-1α,NO and ROS,predominantly through the downregulation of M4-mAChR.The findings offer novel understandings regarding AT3-mediated attenuation of endothelial cell apoptosis and cerebral ischemia/reperfusion injury.
文摘OBJECTIVE Abnormal striatal dopaminergic and glutamatergic neurotransmis⁃sion is central to the pathophysiology of schizo⁃phrenia.In this study,we investigated the roles of M4 receptor interplay with D1 signaling in stria⁃tal neurotransmission that affect glutamatergic transmission to control the etiology of neuropsy⁃chiatric disorders.METHODS To study dorsal striatum(DS)region-specific neuronal and behav⁃ioral responses modulated by M4 receptors,we used clustered regularly interspaced short palin⁃dromic repeats-associated protein 9 technology to generate mice lacking M4 in the dorsal stria⁃tum(DS-M4-KD).The M4 positive allosteric modu⁃lator,VU0467154,were used to study the phar⁃macologically profiles with M4 receptor stimula⁃tion in WT mice.Oxotremorine M(Oxo-M),a no subtype-selective muscarinic agonist,was used to show that mAchRs activation,in order to dissect the particular function of M4,in DS-M4-KD mice.Open filed test and forced swim test were used to assess the change of psychiatric-like behav⁃iors.Western blotting and immunohistochemistry were used to detect protein levels of phosphory⁃lation site of dopamine-and cAMP-regulated phosphoprotein of 32 ku(DARPP-32).Whole-cell patch-clamp recording was used to assess M4-mediated cholinergic inhibition of glutamater⁃gic synaptic input transmission.RESULTS West⁃ern blotting and immunohistochemistry assay showed VU0467154(5 mg·kg-1,ip)promoted phosphorylation of DARPP-32 at Thr75,and atten⁃uated D1-dependent phosphorylation of DARPP-32 at Thr34 within the mouse DS.Consistently,the Oxo-M(4μg,icv)also increased DARPP-32 phosphorylation at site Thr75 to reversed phos⁃phorylation at site Thr34 in WT mice,but not in DS-M4-KD mice.In parallel with altered DARPP-32 responses,VU0467154 or Oxo-M evoked a psychological stress response and reversed D1-induced hyperlocomotion in mice in open field test and force swim tests.However,Oxo-M sup⁃pression of D1-depengdeng behavioral respons⁃es was impaired in DS-M4-KD mice.Whole-cell patch recording showed that VU0467154 or Oxo-M mediated endogenous cholinergic inhibition of miniature excitatory postsynaptic currents through M4 receptors,which in turn suppressed D1-depen⁃dent glutamatergic synaptic transmission in the DS.CONCLUSION This study provides evidence for the role of M4 receptors in regulation of dopa⁃mine/DARPP-32 signaling and glutamate respons⁃es in the DS,and therefore modulation of psychi⁃atric behaviors associated with D1 signaling.This results indicate the mechanisms of treatments targeting M4 in psychiatric disorders.
文摘The development of breast cancer is a complex process that involves the participation of different factors.Several authors have demonstrated the overexpression of muscarinic acetylcholine receptors(mAChRs)in different tumor tissues and their role in the modulation of tumor biology,positioning them as therapeutic targets in cancer.The conventional treatment for breast cancer involves surgery,radiotherapy,and/or chemotherapy.The latter presents disadvantages such as limited specificity,the appearance of resistance to treatment and other side effects.To prevent these side effects,several schedules of drug administration,like metronomic therapy,have been developed.Metronomic therapy is a type of chemotherapy in which one or more drugs are administered at low concentrations repetitively.Recently,two chemotherapeutic agents usually used to treat breast cancer have been considered able to activate mAChRs.The combination of low concentrations of these chemotherapeutic agents with muscarinic agonists could be a useful option to be applied in breast cancer treatment,since this combination not only reduces tumor cell survival without affecting normal cells,but also decreases pathological neo-angiogenesis,the expression of drug extrusion proteins and the cancer stem cell fraction.In this review,we focus on the previous evidences that have positioned mAChRs as relevant therapeutic targets in breast cancer and analyze the effects of administering muscarinic agonists in combination with conventional chemotherapeutic agents in a metronomic schedule.
