Breast cancer:Muscarinic receptors as new targets for tumor therapy

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.

Effect of Daicong solution on hippocampal muscarinic receptors 1 and 3 gene expression in a rat model of Alzheimer’s disease

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.

M_(4) muscarinic receptors regulates dopamine/DARPP-32 signaling and glutamate transmis⁃sion to balance dopaminergic D1 function in mouse dorsal striatum

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.

Stimulatory activity of anti-peptide antibodies against the second extracellular loop of human M_2 muscarinic receptors

Obejctive To study the activity of anti peptide antibodies against the second extracellular loop of human M 2 muscarinic receptors on cAMP production and inward calcium currents (I Ca ) in guinea pig ventricular myocytes A comparison was also made with those of a muscarinic receptor agonist Methods cAMP content was determined by radioimmunoassay and the I Ca in guinea pig single ventricular cells were recorded by the whole cell patch clamp technique Results Both the muscarinic receptor agonist, carbachol (Carb 10?μmol/L), and anti peptide antibodies (Abs 100?nmol/L) could decrease basal cAMP levels (by 46 9%±4 2% and 60 2%±4 6%, respectively) and basal I Ca Both Carb (10?μmol/L) and Abs (100?nmol/L) could also inhibit the isoprenaline induced (Iso 0 8?μmol/L) increases in cAMP production (from 108 2±7 0 to 88 4±7 2? pmol/mg·protein/min for Carb and 88 6±5 1? pmol/mg· protein/min for Abs, respectively) and the increases in I Ca The muscarinic receptor antagonist atropine (Atr) was able to prevent these effects of Carb and Abs Conclusions Anti peptide antibodies against an epitope located in the second extracellular loop of human M 2 muscarinic receptors, similar to muscarinic receptor agonist, could decrease the basal I Ca and β receptor agonist stimulated increase of I Ca by decreasing the basal and β receptor agonist stimulated increase of cAMP production, and therefore could have an effect on their target receptor These results further suggest that autoimmunity may participate in the pathogenesis of human cardiomyopathy and the second extracellular loop of human M 2 muscarinic receptor could be the main immunodominant region.

Effects of gamma-aminobutyric acid receptors on muscarinic receptor-mediated free calcium ion levels in the facial nucleus following facial nerve injury

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.

Anisodine hydrobromide alleviates oxidative stress caused by hypoxia/reoxygenation in human cerebral microvascular endothelial cells predominantly via inhibition of muscarinic acetylcholine receptor 4

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.

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.

Insights into the structural biology of G-protein coupled receptors impacts drug design for central nervous system neurodegenerative processes

In the last few years, there have been important new insights into the structural biology of G-protein coupled receptors. It is now known that allosteric binding sites are involved in the affinity and selec- tivity of ligands for G-protein coupled receptors, and that signaling by these receptors involves both G-protein dependent and independent pathways. The present review outlines the physiological and pharmacological implications of this perspective for the design of new drugs to treat disorders of the central nervous system. Specifically, new possibilities are explored in relation to allosteric and or- thosteric binding sites on dopamine receptors for the treatment of Parkinson＇s disease, and on muscarinic receptors for Alzheimer＇s disease. Future research can seek to identify ligands that can bind to more than one site on the same receptor, or simultaneously bind to two receptors and form a dimer. For example, the design of bivalent drugs that can reach homo/hetero-dimers of D2 dopa- mine receptor holds promise as a relevant therapeutic strategy for Parkinson＇s disease. Regarding the treatment of Alzheimer＇s disease, the design of dualsteric ligands for mono-oligomeric mus- carinic receptors could increase therapeutic effectiveness by generating potent compounds that could activate more than one signaling pathway.

AduoLa Fuzhenglin Down-regulates Microwave-induced Expression of β_1-adrenergic Receptor and Muscarinic Type 2 Acetylcholine Receptor in Myocardial Cells of Rats

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.

Muscarinic receptor-mediated calcium changes in a rat model of facial nerve nucleus injury

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.

M3 Muscarinic Acetylcholine Receptor Antagonist Darifenacin Protects against Pulmonary Fibrosis through ERK/NF-κB/miR-21 Pathway

Idiopathic pulmonary fibrosis is an untreatable lethal lung disease, which is related to the aberrant proliferation of fibroblasts. M3 muscarinic acetylcholine receptor (M3-mAChR) activation exerts proliferative effect on various kinds of cells. However, whether M3-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 M3-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. M3-mAChR antagonist darifenacin attenuates bleomycin-induced pulmonary fibrosis in rats, which may relate to the ERK/NF-κB/miRNA-21 signaling pathway.

Muscarinic Acetylcholine Receptor Subtype Expression in Type Vestibular Hair Cells of Guinea Pigs

Recent studies have demonstrated that five subtypes （M1-M5） of muscarinic acetylcholine receptor （mAChR） are expressed in the vestibular periphery. However, the exact cellular location of the mAChRs is not clear. In this study, we investigated whether there is the expression of M1-M5 muscarinic receptor mRNA in isolated type Ⅱ vestibular hair cells of guinea pig by using single-cell RT-PCR. In vestibular end-organ, cDNA of the expected size was obtained by RT-PCR. Moreover, mRNA was identified by RT-PCR from individually isolated type Ⅱ vestibular hair cells （single-cell RT-PCR）. Sequence analysis confirmed that the products were M1-M5 mAChR. These results dem-onstrated that M1-M5 mAChR was expressed in the typeⅡvestibular hair cells of the guinea pig, which lends further support for the role of M1-M5 mAChR as a mediator of efferent cholinergic signalling pathway in vestibular hair cells.

Multiple roles for cholinergic signaling in pancreatic diseases

Cholinergic nerves are widely distributed throughout the human body and participate in various physiological activities,including sensory,motor,and visceral activities,through cholinergic signaling.Cholinergic signaling plays an important role in pancreatic exocrine secretion.A large number of studies have found that cholinergic signaling overstimulates pancreatic acinar cells through muscarinic receptors,participates in the onset of pancreatic diseases such as acute pancreatitis and chronic pancreatitis,and can also inhibit the progression of pancreatic cancer.However,cholinergic signaling plays a role in reducing pain and inflammation through nicotinic receptors,but enhances the proliferation and invasion of pancreatic tumor cells.This review focuses on the progression of cholinergic signaling and pancreatic diseases in recent years and reveals the role of cholinergic signaling in pancreatic diseases.

Cardiac autonomic nerve distribution and arrhythmia

OBJECTIVE： To analyze the distribution characteristics of cardiac autonomic nerves and to explore the correlation between cardiac autonomic nerve distribution and arrhythmia. DATA RETRIEVAL： A computer-based retrieval was performed for papers examining the distribution of cardiac autonomic nerves, using “heart, autonomic nerve, sympathetic nerve, vagus nerve, nerve distribution, rhythm and atrial fibrillation” as the key words. SELECTION CRITERIA： A total of 165 studies examining the distribution of cardiac autonomic nerve were screened, and 46 of them were eventually included. MAIN OUTCOME MEASURES： The distribution and characteristics of cardiac autonomic nerves were observed, and immunohistochemical staining was applied to determine the levels of tyrosine hydroxylase and acetylcholine transferase （main markers of cardiac autonomic nerve distribution）. In addition, the correlation between cardiac autonomic nerve distribution and cardiac arrhythmia was investigated. RESULTS： Cardiac autonomic nerves were reported to exhibit a disordered distribution in different sites, mainly at the surface of the cardiac atrium and pulmonary vein, forming a ganglia plexus. The distribution of the pulmonary vein autonomic nerve was prominent at the proximal end rather than the distal end, at the upper left rather than the lower right, at the epicardial membrane rather than the endocardial membrane, at the left atrium rather than the right atrium, and at the posterior wall rather than the anterior wall. The main markers used for cardiac autonomic nerves were tyrosine hydroxylase and acetylcholine transferase. Protein gene product 9.5 was used to label the immunoreactive nerve distribution, and the distribution density of autonomic nerves was determined using a computer-aided morphometric analysis system. CONCLUSION： The uneven distribution of the cardiac autonomic nerves is the leading cause of the occurrence of arrhythmia, and the cardiac autonomic nerves play an important role in the occurrence, maintenance, and symptoms of arrhythmia.

Evaluation of the gastrointestinal anti-motility effect of Anacardium occidentale stem bark extract:A mechanistic study of antidiarrheal activity

Diarrhea is a prevalent gastrointestinal problem associated with fatal implications.It is a huge public health concern that requires better alternatives to current drugs.This study investigated the mechanisms involved in the antidiarrheal activity of Anacardium occidentale(Ao) stem bark extract,a plant commonly used in the management of diarrhea in Nigeria.Methanolic stem bark extract of the plant was partitioned into three fractions:hexane fraction,ethyl acetate fraction(Ao EF) and methanol fraction.In vitro studies on the effect of these fractions on guinea pig ileum(GPI) strips,as well as the modulatory effect of Ao EF on standard agonists-and antagonists-induced GPI contraction and relaxation,revealed Ao EF as the most active fraction.In vivo studies to assess the effect of Ao EF on the dopaminergic,muscarinic,and serotonergic pathways were carried out using gastric emptying(GE) and gastrointestinal transit(GT) as experimental end points.Ao EF was subjected to GC-MS analysis,while the identified compounds were docked with the muscarinic acetylcholine receptor M3(CHRM3) using Autodock Vina.Results indicated that Ao EF inhibited GE and GT via inhibition of CHRM3.In addition,GC-MS analysis revealed the presence of 24 compounds in Ao EF,while docking indicated that octadecanoic acid 2-(2-hydroxylethoxy)ethyl ester exhibited the highest binding affinity to CHRM3.This study indicated that the antidiarrheal activity of Ao is through its antimotility effect via the inhibition of the muscarinic pathway.And since none of the identified compounds exhibited higher binding affinity to CHRM3 relative to loperamide,the antimotility activity of these phytoconstituents may be via synergism.

Resolution and Crystal Structure of 9α-(3-Azabicyclo[3,3,1]nonanyl)- 2′-cyclopentyl-2′-hydroxyl-2′-thienylacetate

The crystal structure of 9α-（3-azabicyclo[3,3,1]nonanyl）-2′-cyclopentyl-2′-hydro- xyl-2′-thienylacetate （C16H27NO3S, Mr = 349.48） has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic, space group P212121 with a = 14.937（3）, b = 8.1673（16）, c = 15.423（3） ,A, V = 1881.5（6） ,A^3, Z = 4, Dc =1.234 g/cm^3, μ = 0.188 mm^-1, F（000） = 752, the final R = 0.0468 and wR = 0.1251. The bicyclo[3,3,1]nonane ring system adopts the most favored twin-chair conformation. The crystal structure shows the existence of intramolecular O-H…O hydrogen bonds by which a one-dimensional chain structure is formed.

Beauty of the beast: anticholinergic tropane alkaloids in therapeutics

Tropane alkaloids(TAs)are among the most valued chemical compounds known since pre-historic times.Poisonous plants from Solanaceae family(Hyoscyamus niger,Datura,Atropa belladonna,Scopolia lurida,Mandragora officinarum,Duboisia)and Erythroxylaceae(Erythroxylum coca)are rich sources of tropane alkaloids.These compounds possess the anticholinergic properties as they could block the neurotransmitter acetylcholine action in the central and peripheral nervous system by binding at either muscarinic and/or nicotinic receptors.Hence,they are of great clinical impor-tance and are used as antiemetics,anesthetics,antispasmodics,bronchodilator and mydriatics.They also serve as the lead compounds to generate more effective drugs.Due to the important pharmacological action they are listed in the WHO list of essential medicines and are available in market with FDA approval.However,being anticholinergic in action,TA medication are under the suspicion of causing dementia and cognitive decline like other medications with anticholinergic action,interestingly which is incorrect.There are published reviews on chemistry,biosynthesis,phar-macology,safety concerns,biotechnological aspects of TAs but the detailed information on anticholinergic mecha-nism of action,clinical pharmacology,FDA approval and anticholinergic burden is lacking.Hence the present review tries to fill this lacuna by critically summarizing and discussing the above mentioned aspects.

Muscarinic acetylcholine receptor M1 mediates prostate cancer cell migration and invasion through hedgehog signaling

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.

Serum IgA against type 3 muscarinic acetylcholine receptor is a novel marker in diagnosis of Sjoegren＇s syndrome

Background Antibodies against type 3 muscarinic acetylcholine receptor （M3R） are involved in the pathogenesis of Sj6gren＇s syndrome （SS）, but the clinical value of them in SS patients has been controversial. The aims of this study were to： （1） establish an improved enzyme-linked immunosorbent assay （ELISA） to detect IgA antibodies against M3R; （2） evaluate the value of IgA antibodies against the second extracellular loop of M3R205-220 （c2M3RP） in diagnosis of SS. Methods To increase the ELISA sensitivity, c2M3RP was coupled to bovine serum albumin （BSA） by the glutaraldehyde method and a 96-well microplate was treated by ultraviolet rays before coated. Concentrations of anti-c2M3RP, anti-SSA, and anti-SSB were measured in the sera of 240 individuals： 91 patients with primary SS and 149 controls （16 secondary SS, 27 systemic lupus erythematosus, 40 rheumatoid arthritis and 66 healthy controls）. Diagnostic properties of anti-c2M3RP were determined by receiver-operating characteristic curve analysis. Results The prevalence of serum IgA anti-c2M3RP antibodies in patients with pSS （46%, 42/91） was significantly higher than that in patients with systemic lupus erythematosus （19%, 5/27）, in rheumatoid arthritis （15%, 6/40） and in healthy controls （5%, 3/66）. However, there was no significant difference between the two $S groups （P=-0.727）. The diagnostic performance of IgA anti-M3RP antibodies was similar to anti-SSA assay, but had 22% higher sensitivity than anti-SSB. By analyzing of IgA anti-c2M3RP antibodies, combination of anti-SSA and anti-SSB resulted in increased sensitivity, whereas their specificity was not significantly changed. Conclusions The improved anti-c2M3RP ELISA is a novel, sensitive, and specific serological test for the diagnosis of SS. The combined application of anti-c2M3RP, anti-SSA and anti-SSB tests can improve the laboratory diagnosis of SS. The IgA anti-c2M3RP antibodies may serve as a novel diagnostic marker for SS.

Muscarinic receptor signaling and colon cancer progression

Due to the lack of effective treatments,advanced colorectal cancer(CRC)remains a leading cause of cancer death in the United States.Emerging evidence supports the observation that muscarinic receptor(MR)signaling plays a critical role in growth and progression of CRC.MR activation by acetylcholine and bile acids results in transactivation of epidermal growth factor receptors(EGFR)and post-EGFR signal transduction that enhances cell proliferation,migration,and invasion.Here,the authors review recent progress in understanding the molecular mechanisms underlying MR-mediated CRC progression and its therapeutic implications.