Levels Of Muscarinic Receptors Research Articles

Changes in levels of the zinc transporter SLC39A12 in Brodmann's area 44: Effects of sex, suicide, CNS pH and schizophrenia

Disturbed CNS zinc homeostasis is suggested as part of the pathophysiology of schizophrenia. Our data, from multiple studies, suggests levels of cortical RNA for the solute carrier family 39 member 12 (SLC39A12), a putative zinc transporter, is higher in people with schizophrenia and is more perturbed in a sub-group of people with the disorder that can be separated because they have very low levels of muscarinic M1 receptors (MRDS). In this study qPCR was used to measure levels of two RNA splice variants of SLC39A12 (a and b) in Brodmann's area (BA) 44 from new cohorts of controls and people with schizophrenia. For the first time, in our study cohort as a whole, we report levels of both splice variants of SLC39A12 are lower in females compared to males and there are correlations between levels of SLC39A12 a and b and CNS pH. Levels of both splice variants were also lower in people with schizophrenia who were suicide completers compared to those who were not. Accounting for these factors, we showed levels of SLC39A12 a and b were higher in BA 44 in schizophrenia compared to controls. In further analyses, with and without our previous data on SLC39A12 a and b, we confirmed changes in levels of SLC39A12 RNAs were more profound in MRDS. In conclusion, our study argues there are higher levels of SLC39A12 a and b in BA 44 in schizophrenia which could be contributing to the breakdown in CNS zinc homeostasis suggested as part of the pathophysiology of schizophrenia, particularly in those with MRDS.

Lower levels of soluble β-amyloid precursor protein, but not β-amyloid, in the frontal cortex in schizophrenia

We identified a sub-group (25%) of people with schizophrenia (muscarinic receptor deficit schizophrenia (MRDS)) that are characterised because of markedly lower levels of cortical muscarinic M1 receptors (CHRM1) compared to most people with the disorder (non-MRDS). Notably, bioinformatic analyses of our cortical gene expression data shows a disturbance in the homeostasis of a biochemical pathway that regulates levels of CHRM1. A step in this pathway is the processing of β-amyloid precursor protein (APP) and therefore we postulated there would be altered levels of APP in the frontal cortex from people with MRDS. Here we measure levels of CHRM1 using [3H]pirenzepine binding, soluble APP (sAPP) using Western blotting and amyloid beta peptides (Aβ1–40 and Aβ1–42) using ELISA in the frontal cortex (Brodmann's area 6: BA 6; MRDS = 14, non-MRDS = 14, controls = 14). We confirmed the MRDS cohort in this study had the expected low levels of [3H]pirenzepine binding. In addition, we showed that people with schizophrenia, independent of their sub-group status, had lower levels of sAPP compared to controls but did not have altered levels of Aβ1–40 or Aβ1–42. In conclusion, whilst changes in sAPP are not restricted to MRDS our data could indicate a role of APP, which is important in axonal and synaptic pruning, in the molecular pathology of the syndrome of schizophrenia.

Lower levels of cortical [3H]pirenzepine binding to postmortem tissue defines a sub-group of older people with schizophrenia with less severe cognitive deficits

Multiple lines of evidence argue for lower levels of cortical muscarinic M1 receptors (CHRM1) in people with schizophrenia which is possibly due to a sub-group within the disorder who have a marked loss of CHRM1 (muscarinic receptor deficit sub-group (MRDS)). In this study we sought to determine if the lower levels of CHRM1 was apparent in older people with schizophrenia and whether the loss of CHRM1 was associated with symptom severity by measuring levels of cortical [3H]pirenzepine binding to CHRM1 from 56 people with schizophrenia and 43 controls. Compared to controls (173±6.3 fmol / mg protein), there were lower levels of cortical [3H]pirenzepine binding in the people with schizophrenia (mean±SEM: 153±6.0 fmol / mg protein; p=0.02; Cohen's d=- 0.46). [3H]pirenzepine binding in the people with schizophrenia, but not controls, was not normally distributed and best fitted a two-population solution. The nadir of binding separating the two groups of people with schizophrenia was 121 fmol / mg protein and levels of [3H]pirenzepine binding below this value had a 90.7% specificity for the disorder. Compared to controls, the score from the Clinical Dementia Rating Scale (CDR) did not differ significantly in MRDS but were significantly higher in the sub-group with normal radioligand binding. Positive and Negative Syndrome Scale scores did not differ between the two sub-groups with schizophrenia. Our current study replicates and earlier finding showing a MRDS within schizophrenia and, for the first time, suggest this sub-group have less severe cognitive deficits others with schizophrenia.

An M1/sigma‐1 receptor agonist prevents cognitive deficits, reduces amyloid plaques and neuroinflammation in a transgenic rat model of Alzheimer’s amyloid pathology.

AbstractBackgroundAcetylcholinesterase inhibitors represent four out of six drugs for treating Alzheimer’s disease (AD), with time‐limited efficacy likely due to the progressive loss of cholinergic neurons. The selective allosteric M1 muscarinic and sigma‐1 receptor agonist Anavex 3‐71 (aka AF710B) [1] takes advantage of the fact that acetylcholine postsynaptic M1 muscarinic brain receptor levels remain unchanged in AD. Previously, Anavex 3‐71 treatment attenuated AD hallmarks in McGill‐R‐Thy1‐APP transgenic rats when administered at advanced stages of the AD‐like pathology [2]. However, preventive strategies instead of late treatment should be more effective in AD. Therefore, we tested whether Anavex 3‐71 administration during early amyloid pathology stages could prevent cognitive impairment, plaque deposition and neuroinflammation.MethodPre‐plaque, seven‐month‐old McGill‐R‐Thy1‐APP rats were subjected to daily oral administration of Anavex 3‐71 (10 µg/kg) for seven months. After one month of drug interruption (wash‐out), we performed Novel Object Recognition (NOR), Morris Water Maze (MWM) and Social Preference (SP) behavioural tests. Subsequently, brains were extracted, fixed and analyzed by histochemistry and immunohistochemistry.ResultMcGill‐APP rats had deficits in discriminating the novel object in the NOR and locating the hidden platform in the MWM compared to wild‐type littermates. Anavex 3‐71 restored the abilities of McGill‐APP rats in the NOR task to wild‐type levels and partially rescued the deficits in the MWM. In the SP task, Anavex 3‐71‐treated McGill‐APP rats exhibited diminished deficits in SP interaction time with a “stranger rat”. Treatment significantly reduced the number of mature Thioflavin‐S positive plaques in the subiculum compared to vehicle‐treated McGill‐APP rats and diminished the number of diffuse plaques in the cortex and hippocampus. Furthermore, Anavex 3‐71 treatment significantly reduced microglia and astrocyte recruitment towards CA1 hippocampal Aβ‐burdened neurons compared to untreated McGill‐APP rats.ConclusionThe long‐lasting effect of Anavex 3‐71 in preventing cognitive decline of McGill‐R‐Thy1‐APP rats, even after a wash‐out period would suggest some preventative, disease‐modifying, properties of the compound over the AD‐like amyloid pathology. This is supported by the attenuation of extracellular Aβ deposition and reduced glial cell recruitment towards hippocampal neurons. [1] Fisher et al., 2016; Neurodegenerative Diseases. https://doi.org/10.1159/000440864 [2] Hall et al., 2018; Alzheimer’s & Dementia. https://doi.org/10.1016/j.jalz.2017.11.009

Continuous administration of mirabegron has advantages in inhibition of central sensitization compared with short-term treatment cessation in a mouse model of overactive bladder.

There is no clear pathophysiologic evidence determining how long overactive bladder (OAB) medication should be continued. We, therefore, investigated the effect of mirabegron using cessation (CES) or continuation (CON) treatment in an OAB animal model. Female C57BL/6 mice were divided into four groups (N = 8 each): Sham, OAB, CES, and CON groups. The OAB-like condition was induced by three times weekly intravesical instillations of KCl mixture with hyaluronidase. After the last intravesical instillation for inducing OAB, mirabegron (2 mg/kg/day) was administered in CES and CON groups for 10 and 20 days, respectively. Final experiments were carried out on 20 days from the last intravesical instillation in all groups. After cystometry, mRNA levels of bladder muscarinic, β-adrenergic, and P2X purinergic receptors were measured to investigate bladder efferent and afferent activity. In addition, mRNA levels of CCL2 and CCR2 in L6-S1 dorsal root ganglia (DRG) were measured to assess afferent sensitization. Immunofluorescent staining of CX3CR1, GFAP, and CCR2 in the L6 spinal cord was also conducted to investigate glial activation and central sensitization. OAB mice showed bladder overactivity evidenced by decreased intercontraction interval (3.56 ± 0.51vs. 5.76 ± 0.95 min in sham mice), increased non-voiding contractions (0.39 ± 0.11vs. 0.13 ± 0.07/min in sham mice), and inefficient voiding (72.1 ± 8.6% vs. 87.1 ± 9.5% in sham mice). Increased M2, M3, β2, β3, P2X2 , P2X3 , P2X4 , and P2X7 levels in the bladder and increased CCL2 and CCR2 in DRG indicate bladder efferent and afferent hyperexcitability. In addition, CX3CR1, GFAP, and CCR2 in the L6 spinal cord were upregulated in OAB mice. However, theCON group exhibited reduced β2, β3, P2X2 , P2X3 , P2X4 , and P2X7 levels in the bladder, reduced CCL2 and CCR2 in DRG, which are markers of afferent hyperexcitability, and reduced immunoreactivities of CX3CR1, GFAP, and CCR2 in the L6 spinal cord, which are markers of the central sensitization. Moreover, theCON group showed better improvements in nonvoiding contractions (0.16 ± 0.09vs. 0.44 ± 0.17/min) and voiding efficiency (93.9 ± 7.4% vs. 76.5 ± 13.1%) and reductions in bladder β3 receptors and CCL2 of L6-S1 DRG, and immunoreactivities of CX3CR1 and GFAP in the L6 spinal cord compared to theCES group. Continuous mirabegron treatment seems to prevent central sensitization and, thus, might be desirable for long-term disease control of OAB.

MP49-15 OVERACTIVE BLADDER MEDICATION; HOW LONG SHOULD IT BE CONTINUED? - MIRABEGRON INTERFERES WITH CENTRAL SENSITIZATION IN A MOUSE MODEL OF OVERACTIVE BLADDER

You have accessJournal of UrologyCME1 May 2022MP49-15 OVERACTIVE BLADDER MEDICATION; HOW LONG SHOULD IT BE CONTINUED? - MIRABEGRON INTERFERES WITH CENTRAL SENSITIZATION IN A MOUSE MODEL OF OVERACTIVE BLADDER Joonbeom Kwon, Eun-Ju Lee, Hye-Ri Park, Hyun-Jung Cho, Ji-Ae Jang, Donghwi Park, and Naoki Yoshimura Joonbeom KwonJoonbeom Kwon More articles by this author , Eun-Ju LeeEun-Ju Lee More articles by this author , Hye-Ri ParkHye-Ri Park More articles by this author , Hyun-Jung ChoHyun-Jung Cho More articles by this author , Ji-Ae JangJi-Ae Jang More articles by this author , Donghwi ParkDonghwi Park More articles by this author , and Naoki YoshimuraNaoki Yoshimura More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002624.15AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The etiology of overactive bladder (OAB) is multifactorial, and bladder afferent hyperexcitability has been proposed to be one of the contributing factors. In addition, chronic afferent hyperexcitability may induce neural remodeling in the central nervous system (CNS). However, there has been no clear pathophysiologic evidence determining how long OAB treatments should be continued. We, therefore, investigated the CNS effect of mirabegron using an OAB animal model and compared the therapeutic effect between treatment cessation (CES) and continuation (CON) groups. METHODS: Female C57BL/6 mice were divided into 4 groups (N=8 in each): Sham, OAB, CES, and CON groups. OAB was induced by 3-times weekly intravesical instillations of KCl and hyaluronidase. Mirabegron (2mg/kg) was administered for 10 and 20 days in CES and CON groups, respectively. Cystometry was performed, and mRNA levels of bladder muscarinic, β-adrenergic, and P2X purinergic receptors were measured. CCL2 and CCR2 in L6-S1 dorsal root ganglia (DRG), as afferent markers, and CX3CR1, GFAP, and CCR2 in the L6 spinal cord, as markers of glial activation and central sensitization, were also evaluated by RT-PCR and immunohistology. RESULTS: OAB mice showed bladder overactivity and inefficient voiding (Fig 1-a) with increased M2, M3, P2X2, P2X3, P2X4, and P2X7 levels in the bladder and increased CCL2 and CCR2 in DRG, indicating afferent hyperexcitability (Fig 1-b). CX3CR1, GFAP, and CCR2 in the L6 spinal cord were upregulated in the OAB group (Fig 1-c). However, CON mice exhibited improvements of all these parameters of afferent hyperexcitability and central sensitization. Also, CON mice showed better voiding efficiency and reduced CNS changes compared with CES mice. CONCLUSIONS: Central sensitization may be an important pathophysiological mechanism of OAB. Continuous treatment of OAB with mirabegron seems to prevent the process of central sensitization via improvement of CNS neural remodeling. Therefore, continuous OAB medication may be desirable for long-term disease control. Source of Funding: Astellas Pharma. Co.Ltd. (ISR005728) © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e859 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joonbeom Kwon More articles by this author Eun-Ju Lee More articles by this author Hye-Ri Park More articles by this author Hyun-Jung Cho More articles by this author Ji-Ae Jang More articles by this author Donghwi Park More articles by this author Naoki Yoshimura More articles by this author Expand All Advertisement PDF DownloadLoading ...

Muscarinic receptor binding activity in rat tissues by vibegron and prediction of its receptor occupancy levels in the human bladder.

To examine the effects of vibegron, a selective β3 -adrenoceptor agonist, used to treat overactive bladder, on muscarinic receptors in the rat bladder, and to predict the occupancy levels of muscarinic receptors by vibegron in the bladders of humans orally administered a clinical dose. Muscarinic receptors in the rat bladder and other tissues were examined by a radioligand binding assay using [N-methyl-3 H]scopolamine chloride. The occupancy levels of muscarinic receptors by vibegron in bladders of humans after its oral administration were predicted from the estimation of unbound concentrations in human plasma and urine in the literature. Vibegron (0.1-100μmol/L) inhibited specific [N-methyl-3 H]scopolamine chloride binding in the bladder and other tissues of rats in a concentration-dependent manner. The 50% inhibitory concentration value of vibegron in the bladder was approximately twofold higher than that in the heart, and approximately 315- and 3.5-fold lower than those in the submaxillary gland and brain, respectively. Therefore, the binding affinity of vibegron for muscarinic receptors was higher in the heart and bladder than in the submaxillary gland and brain. By using the rat bladder receptor binding affinity, occupancy levels of muscarinic receptors in the human bladder were predicted to be 51-91% until 24h after its oral administration at 50mg of vibegron. This is the first study to suggest that vibegron binds to muscarinic receptors in the rat bladder and other tissues, with a potentially higher affinity for the M2 subtype than the M1 and M3 subtypes. These results might be clinically relevant for pharmacotherapy with vibegron for overactive bladder.

Changes in cortical gene expression in the muscarinic M1 receptor knockout mouse: potential relevance to schizophrenia, Alzheimer\u2019s disease and cognition

Postmortem and neuroimaging studies show low levels of cortical muscarinic M1 receptors (CHRM1) in patients with schizophrenia which is significant because CHRM signalling has been shown to change levels of gene expression and cortical gene expression is altered in schizophrenia. We decided to identify CHRM1-mediated changes in cortical gene expression by measuring levels of RNA in the cortex of the Chrm1−/− mouse (n = 10), where there would be no signalling by that receptor, and in wild type mouse (n = 10) using the Affymetrix Mouse Exon 1.0 ST Array. We detected RNA for 15,501 annotated genes and noncoding RNA of which 1,467 RNAs were higher and 229 RNAs lower in the cortex of the Chrm1−/− mouse. Pathways and proteins affected by the changes in cortical gene expression in the Chrm1−/− are linked to the molecular pathology of schizophrenia. Our human cortical gene expression data showed 47 genes had altered expression in Chrm1−/− mouse and the frontal pole from patients with schizophrenia with the change in expression of 44 genes being in opposite directions. In addition, genes with altered levels of expression in the Chrm1−/− mouse have been shown to affect amyloid precursor protein processing which is associated with the pathophysiology of Alzheimer’s disease, and 69 genes with altered expression in the Chrm1−/− mouse are risk genes associated with human cognitive ability. Our findings argue CHRM1-mediated changes in gene expression are relevant to the pathophysiologies of schizophrenia and Alzheimer’s disease and the maintenance of cognitive ability in humans.

Acute Lung Injury in Cholinergic-Deficient Mice Supports Anti-Inflammatory Role of α7 Nicotinic Acetylcholine Receptor.

(1) Background: The lung cholinergic pathway is important for controlling pulmonary inflammation in acute lung injury, a condition that is characterized by a sudden onset and intense inflammation. This study investigated changes in the expression levels of nicotinic and muscarinic acetylcholine receptors (nAChR and mAChR) in the lung during acute lung injury. (2) Methods: acute lung injury (ALI) was induced in wild-type and cholinergic-deficient (VAChT-KDHOM) mice using intratracheal lipopolysaccharide (LPS) instillation with or without concurrent treatment with nicotinic ligands. Bronchoalveolar lavage fluid was collected to evaluate markers of inflammation, and then the lung was removed and processed for isolation of membrane fraction and determination of acetylcholine receptors level using radioligand binding assays. (3) Results: LPS-induced increase in lung inflammatory markers (e.g., neutrophils and IL-1β) was significantly higher in VAChT-KDHOM than wild-type mice. In contrast, LPS treatment resulted in a significant increase in lung’s α7 nicotinic receptor level in wild-type, but not in VAChT-KDHOM mice. However, treatment with PNU 282987, a selective α7 nicotinic receptor agonist, restored VAChT-KDHOM mice’s ability to increase α7 nicotinic receptor levels in response to LPS-induced acute lung injury and reduced lung inflammation. LPS also increased muscarinic receptors level in VAChT-KDHOM mice, and PNU 282987 treatment reduced this response. (4) Conclusions: Our data indicate that the anti-inflammatory effects of the lung cholinergic system involve an increase in the level of α7 nicotinic receptors. Pharmacological agents that increase the expression or the function of lung α7 nicotinic receptors have potential clinical uses for treating acute lung injury.

Single exercise stress reduces central neurotrophins levels and adenosine A1 and A2 receptors expression, but does not revert opioid-induced hyperalgesia in rats.

This study assessed the effects of an acute stress model upon the long-term hyperalgesia induced by repeated morphine administration in neonatal rats. We also evaluated neurotrophins and cytokines levels; expressions of adenosine and acetylcholine receptors, and acetylcholinesterase enzyme at the spinal cord. Male Wistar rats were subjected to morphine or saline administration from P8 to P14. Thermal hyperalgesia and mechanical hyperesthesia were assessed using the hot plate (HP) and von Frey (vF) tests, respectively, at postnatal day P30 and P60. After baseline measurements, rats were subjected to a single exercise session, as an acute stress model, at P30 or P60. We measured the levels of BDNF and NGF, interleukin-6, and IL-10 in the cerebral cortex and the brainstem; and the expression levels of adenosine and muscarinic receptors, as well as acetylcholinesterase (AChE) enzyme at the spinal cord. A stress exercise session was not able to revert the morphine-induced hyperalgesia. The morphine and exercise association in rats induced a decrease in the neurotrophins brainstem levels, and A1 , A2A , A2B receptors expression in the spinal cord, and an increase in the IL-6 cortical levels. The exercise reduced M2 receptors expression in the spinal cord of naive rats, while morphine prevented this effect. Single session of exercise does not revert hyperalgesia induced by morphine in rats; however, morphine plus exercise modulate neurotrophins, IL-6 central levels, and expression of adenosine receptors.

Muscarinic cholinergic receptors in minor salivary gland tissues of patients with oral lichen planus: A case-control study.

Oral lichen planus (OLP) is a common, chronic immunological and inflammatory condition. Many of the OLP patients complain of xerostomia. The M3 muscarinic cholinergic receptors (MR3) are the main receptors in the salivary glands responsible for water secretion into the saliva. This study aimed to assess the level of M3 muscarinic cholinergic receptors in minor salivary glands of OLP patients. This case-control cross-sectional study evaluated 40 OLP patients and 22 controls. All participants completed two questionnaires (xerostomia and xerostomia inventory). Stimulated and unstimulated saliva samples were collected. The saliva flow rate was calculated by dividing the saliva volume (in milliliters) by time (in minutes). Six minor salivary glands were also surgically removed from the lower lip of patients and controls, and weighed using a digital scale with 10-4 g accuracy. They were then frozen at -80°C, and the level of M3 receptors of the glands was determined using the ELISA kit. The unstimulated and stimulated saliva flow rate was significantly lower in OLP patients. The xerostomia inventory score was significantly higher in the OLP group. The level of M3 muscarinic receptors in minor salivary glands of OLP patients was significantly higher than that in controls. It may be concluded that the reduction in saliva flow significantly increases the number of M3 receptors in an attempt to compensate for this shortage and prevent xerostomia (compensatory upregulation).

Higher levels of α7 nicotinic receptors, but not choline acetyltransferase, in the dorsolateral prefrontal cortex from a sub-group of patients with schizophrenia

It has been suggested the study of sub-groups within the syndrome of schizophrenia will assist in elucidating the complex pathophysiology of the syndrome. Hence, we have studied a number of cholinergic markers in the cortex from a sub-group of subjects with schizophrenia that have a marked decrease in levels of muscarinic M1 receptors (MRDS). The displacement of [3H]NMS by cortical extracts was used to measure tissue anticholinergic load, [125I]α bungarotoxin binding was used to measure levels of the α7 nicotinic receptor (CHRNA7) and western blotting was used to measure levels of choline acetyltransferase (ChAT) 68 and 82 as well as synaptosome nerve-associated protein 25 (SNAP25). In comparing schizophrenia, MRDS and non-MRDS to controls, there were no differences in levels of ChAT 68 or 82, SNAP 25 or cholinergic load in BA 9. However, levels of CHRNA7 were higher in BA 9, but not BA 6 or 44, from subjects with MRDS. These data argue that there is no change in cholinergic innovation (measured using ChAT), presynaptic neurons (measured using SNAP25) or cholinergic load in schizophrenia, MRDS or non-MRDS. However, increased levels of CHRNA7 may be contributing to a breakdown in cholinergic homeostasis in BA 9, but not BA 6 or 44, in subjects with MRDS.

M1 muscarinic acetylcholine receptor dysfunction in moderate Alzheimer's disease pathology.

Aggregation of amyloid beta and loss of cholinergic innervation in the brain are predominant components of Alzheimer’s disease pathology and likely underlie cognitive impairment. Acetylcholinesterase inhibitors are one of the few treatment options for Alzheimer’s disease, where levels of available acetylcholine are enhanced to counteract the cholinergic loss. However, these inhibitors show limited clinical efficacy. One potential explanation for this is a concomitant dysregulation of cholinergic receptors themselves as a consequence of the amyloid beta pathology. We tested this hypothesis by examining levels of M1 muscarinic acetylcholine receptors in the temporal cortex from seven Alzheimer’s disease and seven non-disease age-matched control brain tissue samples (control: 85 ± 2.63 years old, moderate Alzheimer’s disease: 84 ± 2.32 years old, P-value = 0.721; eight female and six male patients). The samples were categorized into two groups: ‘control’ (Consortium to Establish a Registry for Alzheimer’s Disease diagnosis of ‘No Alzheimer’s disease’, and Braak staging pathology of I–II) and ‘moderate Alzheimer’s disease’ (Consortium to Establish a Registry for Alzheimer’s Disease diagnosis of ‘possible/probable Alzheimer’s disease’, and Braak staging pathology of IV). We find that in comparison to age-matched controls, there is a loss of M1 muscarinic acetylcholine receptors in moderate Alzheimer’s disease tissue (control: 2.17 ± 0.27 arbitrary units, n = 7, Mod-AD: 0.83 ± 0.16 arbitrary units, n = 7, two-tailed t-test, t = 4.248, P = 0.00113). Using a functional rat cortical brain slice model, we find that postsynaptic muscarinic acetylcholine receptor function is dysregulated by aberrant amyloid beta-mediated activation of metabotropic glutamate receptor 5. Crucially, blocking metabotropic glutamate receptor 5 restores muscarinic acetylcholine receptor function and object recognition memory in 5XFAD transgenic mice. This indicates that the amyloid beta-mediated activation of metabotropic glutamate receptor 5 negatively regulates muscarinic acetylcholine receptor and illustrates the importance of muscarinic acetylcholine receptors as a potential disease-modifying target in the moderate pathological stages of Alzheimer’s disease.

Relationship between impaired parasympathetic vasodilation and hyposalivation in parotid glands associated with type 2 diabetes mellitus.

We examined the relationship between hemodynamics in the three major salivary glands and salivary secretion in urethane-anesthetized and sympathectomized type 2 diabetic and nondiabetic rats via laser speckle imaging and by collecting the saliva. Lingual nerve stimulation elicited rapid increases in glandular blood flow and induced salivary secretion from the three glands in both diabetic and nondiabetic rats. In the parotid gland, the magnitude of blood flow increase and salivary secretion was significantly lower in the diabetic rats when compared with the nondiabetic rats; however, this was not observed in the other glands. Although the intravenous administration of acetylcholine increased blood flow in the parotid gland in a dose-dependent manner, the response was significantly lower in the diabetic rats when compared with the nondiabetic rats. Similarly, mRNA expression levels of M1 and M3 muscarinic acetylcholine receptors in the parotid gland were relatively lower in the diabetic rats compared with the nondiabetic rats. Our results indicate that type 2 diabetes impairs parasympathetic vasodilation and salivary secretion in the parotid gland and suggest that disturbances in the cholinergic vasodilator pathway may contribute to the underlying mechanisms involved in the disruption of parasympathetic nerve-mediated glandular vasodilation.

Contribution of cholinergic system and Nrf2/HO-1 signaling to the anti-amnesic action of 7-fluoro-1,3-diphenylisoquinoline-1-amine in mice

The isoquinoline 7-fluoro-1,3-diphenylisoquinoline-1-amine (FDPI) has been studied due to its multitarget properties, such as modulation of GABAergic and glutamatergic systems, antioxidant, and anti-inflammatory. This study investigated the contribution of oxidative stress, nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase (HO-1) signaling, and the cholinergic system to the anti-amnesic action of FDPI in mice. Adult male Swiss mice received FDPI for 5 days (5–25 mg/kg, i.g.); the animals received scopolamine (1 mg/kg, i.p) from day 3–5. The vehicle-control group was carried out. Afterward, mice performed object recognition tests (ORTs). Scopolamine induced amnesia and cholinergic dysfunction by increasing the acetylcholinesterase (AChE) activity and content, decreasing the muscarinic M1 receptor levels in the prefrontal cortex and hippocampus of mice. This study reveals that scopolamine altered oxidative stress parameters differently in the prefrontal cortex and hippocampus of mice. Whereas the prefrontal cortex was susceptible to oxidative stress, none of the parameters evaluated was altered in the hippocampus of scopolamine-treated mice. FDPI at doses of 10 and 25 mg/kg had an anti-amnesic effect in the ORT tests. FDPI 10 mg/kg reversed the increase in the AChE activity and content, oxidative stress parameters, and modulated Nrf2/HO-1 signaling in the prefrontal cortex of scopolamine-exposed mice. Pearson's correlation analyses reinforced the contribution of the prefrontal cortical cholinergic system, oxidative stress as well as Nrf2/HO-1 signaling in the anti-amnesic effect of FDPI. Considering FDPI effects on the hippocampus, it was effective against the cholinergic dysfunction, AChE activity and content, and M1 receptor levels, which collectively could contribute to its anti-amnesic effect.

Low levels of muscarinic M1 receptor-positive neurons in cortical layers III and V in Brodmann areas 9 and 17 from individuals with schizophrenia.

Results of neuroimaging and postmortem studies suggest that people with schizophrenia may have lower levels of muscarinic M1 receptors (CHRM1) in the cortex, but not in the hippocampus or thalamus. Here, we use a novel immunohistochemical approach to better understand the likely cause of these low receptor levels. We determined the distribution and number of CHRM1-positive (CHRM1+) neurons in the cortex, medial dorsal nucleus of the thalamus and regions of the hippocampus from controls (n = 12, 12 and 5, respectively) and people with schizophrenia (n = 24, 24 and 13, respectively). Compared with controls, levels of CHRM1+ neurons in people with schizophrenia were lower on pyramidal cells in layer III of Brodmann areas 9 (-44%) and 17 (-45%), and in layer V in Brodmann areas 9 (-45%) and 17 (-62%). We found no significant differences in the number of CHRM1+ neurons in the medial dorsal nucleus of the thalamus or in the hippocampus. Although diagnostic cohort sizes were typical for this type of study, they were relatively small. As well, people with schizophrenia were treated with antipsychotic drugs before death. The loss of CHRM1+ pyramidal cells in the cortex of people with schizophrenia may underpin derangements in the cholinergic regulation of GABAergic activity in cortical layer III and in cortical/subcortical communication via pyramidal cells in layer V.

MP58-15 M2 AND M3 MUSCARINIC RECEPTOR EXPRESSION IN BLADDER TUMOR

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology II1 Apr 2018MP58-15 M2 AND M3 MUSCARINIC RECEPTOR EXPRESSION IN BLADDER TUMOR Mehmet Kazim Asutay, Banu Aydin, Hasan Toper, Deniz Filinte, Hülya Cabadak, and Ilker Tinay Mehmet Kazim AsutayMehmet Kazim Asutay More articles by this author , Banu AydinBanu Aydin More articles by this author , Hasan ToperHasan Toper More articles by this author , Deniz FilinteDeniz Filinte More articles by this author , Hülya CabadakHülya Cabadak More articles by this author , and Ilker TinayIlker Tinay More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.1847AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Bladder cancer is one of the most common urogenital cancers of Western society. Transitional cell carcinoma is a heterogeneous cancer type, which costitudes 90% of all bladder cancers. Urothelial cells are continuously in relation with several signal molecules and neurotransmitters. One of these, muscarinic acetyl choline receptors, are expressed on both urothelial cells and detrusor muscle and play a great role in human bladder physiology. Specifically M2 and M3 type receptors are the most common receptors of bladder. M2 receptors are specially found on umbrella cells on the mucosa layer of bladder and almost up to three times more frequent than M3 receptors. Some of the recent studies show the importance and role of muscarinic receptors on some types of disease. In this study muscarinic receptor expression, namely M2 and M3 subtypes of muscarinic receptors were analyzed on bladder tumor samples. METHODS In order to have a strong evidence of M2 and M3 subtypes in bladder tumors, the samples were analyzed both with Western blot technique and with immunohistochemistry. Bladder tumor samples, which are collected by transurethral resection of the bladder, are homogenized, centrifuged and preserved at -80?C. Protein component was analyzed via Lowry method. p< 0.05 data were accepted as statistically significant. The samples also were analyzed by pathologists with immunohistochemistry technique for M2 and M3 muscarinic receptor expression. RESULTS Data of 45 patients were analyzed. Statistical analyses show that patients with pathological T2 stage and with progressed disease during follow-up have greater M2 receptor value which is statistically significant. There was no relation between M3 muscarinic receptor level and tumor grade/stage or progression rate. These results were not dependent by patient age or lower urinary tract symptoms. Progression rate was found higher in patients with higher M2 muscarinic receptor levels on bladder tissue samples. CONCLUSIONS M2 and M3 muscarinic receptors not only play a great role on bladder functions but also also may be important for bladder cancer pathophysiology though, their role in the development of blader cancer has not been defined yet. This current trial may indicate M2 receptors to be a potential treatment target for bladder cancer. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e778 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Mehmet Kazim Asutay More articles by this author Banu Aydin More articles by this author Hasan Toper More articles by this author Deniz Filinte More articles by this author Hülya Cabadak More articles by this author Ilker Tinay More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

43.2 MUSCARINIC M1 RECEPTORS: INVOLVEMENT IN THE PATHOPHYSIOLOGY AND TREATMENT OF SCHIZOPHRENIA

BackgroundEvidence from postmortem CNS studies and a neuroimaging study suggest that, compared to controls, there are low levels of muscarinic receptors in a number of CNS regions from subjects with schizophrenia. Current data suggests the muscarinic M1 receptor is lower in the cortex of subjects with schizophrenia but other muscarinic receptors may be decreased in sub-cortical regions such as the striatum and hippocampus. In addition, it has been reported that ~25% of subjects with schizophrenia can be divided into a distinct sub-group because they have a marked decrease in cortical muscarinic M1 receptors (muscarinic receptor deficit schizophrenia (MRDS)). These findings have become of clinical significance because proof of principal data shows that treating subjects with schizophrenia with drugs that activate the muscarinic M1 receptor is effective in lessening the symptoms associated with the disorder.MethodsPublished and unpublished data will be reviewed to challenge the hypothesis that drugs that activate the muscarinic M1 receptor will be useful in treating schizophrenia.ResultsA proof of clinical trial has shown that treating subjects with treatment resistant schizophrenia with the muscarinic M1 and 4 receptor agonist, xanomeline, improves positive and negative symptoms as well as cognitive deficits. Moreover, it has more recently been reported that giving xanomeline on a transdermal patch with a peripheral muscarinic receptor antagonist can lessen the unwanted side effects of the drug to that of placebo. Relevant to these data is the finding that there is a sub-group of subjects with MRDS as the absence of cortical muscarinic M1 receptors in these receptors may make these subjects resistant to treatment with muscarinic M1 receptor agonists. However, novel studies using postmortem CNS from subjects with MRDS and non-MRDS has shown that whilst subjects with MRDS will likely be resistant to muscarinic M1 receptor orthosteric agonists (oxotremorine-M) they will, at least partially, respond to muscarinic M1 receptor allosteric agonists (AC-42) or positive allosteric modulators (BQCA).DiscussionMuscarinic receptor agonism appears to be a promising new treatment for schizophrenia. However, some subjects with MRDS may only respond to activation of the allosteric site on the muscarinic M1 receptor. Evidence from a neuroimaging study suggests subjects with MRDS can be identified whilst living. Hence, establishing the muscarinic receptor status of subjects involved in trials of muscarinic M1 receptor agonists may help in explaining varying levels of treatment responsiveness in subjects with schizophrenia. These conclusions, being directed by data from studies using postmortem CNS, reflect the need for drug discovery and delivery to be based on a growing understanding of the pathophysiology(ies) of schizophrenia.

Age-related changes in function and gene expression of the male and female mouse bladder

We investigated age-related changes in in vivo and in vitro functions and gene expression of the bladder of male and female mice. Mature and aged (12 and 27–30 month old) C57BL/6 mice of both sexes were used. Frequency volume, conscious free-moving cystometry and detrusor contractile and relaxant properties in in vitro organ bath were evaluated. mRNA expression level of muscarinic, purinergic, and β-adrenergic receptors and gene expression changes by cDNA microarray analysis of the bladder were determined. Cystometry demonstrated storage and voiding dysfunctions with ageing in both sexes. Detrusor strips from aged mice showed weaker contractile responses particularly in the cholinergic component and weaker relaxant responses to isoproterenol. These age-related impairments were generally severer in males. mRNA expression of bladder tissue was decreased for M3 muscarinic receptors in aged males and β2-adrenoceptors in aged females. cDNA microarray analysis results, albeit substantial sex difference, indicated “cell-to-cell signaling and interaction” as the most common feature of age-related gene expression. In summary, aged mice demonstrated voiding and storage dysfunctions resembling to detrusor hyperactivity with impaired contractility (DHIC), which were more pronounced in males. Genomic changes associated with aging may contribute to the age-related bladder functional deterioration in mice.

Influence of exposure to nicotine during pregnancy on the learning and memory for adult offspring.

We aimed to investigate the indirect influence of exposure to nicotine during pregnancy on the learning and memory of adult offspring mice. Thirty pregnant C57 mice were randomly divided into either the control group (CON) or the nicotine group (NIC), with 15 mice each. The CON group was given access to drug-free water, and the NIC group was given 60 g/ml nicotine in drinking water. Sixteen adult mice were randomly selected from the 8 litters for Morris water maze test. The level of products of related factors in the hippocampus of mice in the NIC and the CON groups were compared using the 1H-MRS method. The escape latency time that the adult offspring mice in the NIC group took in the place navigation test was significantly longer than that of the CON group. In addition, the NIC group took longer time to arrive at the plate than the CON group (P<0.05). mRNA and protein levels of NR1 in the hippocampus of the NIC group was significantly higher than that in the CON group (P<0.05).α7nACh mRNA in the hippocampus of the NIC group was not significantly different from that of the CON group (P>0.05), while the expression levels of α7nACh protein in the hippocampus of the NIC group was significantly lower than that in the CON group (P<0.05). Detection of protein level of muscarinic receptors in the hippocampus of adult offspring mice in the NIC group showed that when compared to the CON group, the expression levels of M1, M3, M5 of the NIC group was not significantly different from that of the CON group (P>0.05). Therefore, exposure to nicotine during pregnancy can cause damage to the learning ability of adult offspring mice but do not significantly influence their working memory.