Cigarette smoke and non-neuronal cholinergic system in the airway epithelium of COPD patients

Acetylcholine (ACh), synthesized by Choline Acetyl-Transferase (ChAT), exerts its physiological effects via mAChRM3 in epithelial cells. We hypothesized that cigarette smoke affects ChAT, ACh, and mAChRM3 expression in the airways from COPD patients promoting airway disease. ChAT, ACh, and mAChRM3 were assessed: "ex vivo" in the epithelium from central and distal airways of COPD patients, Healthy Smoker (S) and Healthy Subjects (C), and "in vitro" in bronchial epithelial cells stimulated with cigarette smoke extract (CSE). In central airways, mAChRM3, ChAT, and ACh immunoreactivity was significantly higher in the epithelium from S and COPD than in C subjects. mAChRM3, ChAT, and ACh score of immunoreactivity was high in the metaplastia area of COPD patients. mAChRM3/ChAT and ACh/ChAT co-localization of immunoreactivity was observed in the bronchial epithelium from COPD. In vitro, CSE stimulation significantly increased mAChRM3, ChAT, and ACh expression and mAChRM3/ChAT and ACh/ChAT co-localization in 16HBE and NHBE, and increased 16HBE proliferation. Cigarette smoke modifies the levels of mAChMR3, ChAT expression, and ACh production in bronchial epithelial cells from COPD patients. Non-neuronal components of cholinergic system may have a role in the mechanism of bronchial epithelial cell proliferation, promoting alteration of normal tissue, and of related pulmonary functions.

Muscarinic-3-receptor positive allosteric modulator ASP8302 in patients with underactive bladder. A randomized controlled trial

AIM

The aim of this study is to evaluate safety and efficacy of ASP8302, a novel positive allosteric modulator for the muscarinic M3 receptor (M3-PAM), in patients with underactive bladder (UAB).

METHODS

A randomized, double-blind, placebo-controlled multicenter study was performed in adult male/female subjects with UAB, defined as incomplete bladder emptying (postvoid residual volume [PVR] > 100 ml) without significant bladder outlet obstruction and/or overactive bladder. Subjects were randomized (1:1) to receive 4-week oral once-daily administration of 100 mg ASP8302 or matching placebo. Primary endpoint was a change from baseline in PVR measured by catheterization after standardized bladder filling (PVR_C2 ). Other endpoints included PVR and bladder voiding efficiency (BVE) measured in various ways, uroflowmetry, bladder diary, and questionnaires. Pressure-flow studies were performed in a subgroup.

RESULTS

One hundred and thirty-five patients were randomized (ASP8302 group: 65 patients, placebo group: 70 patients). The median change in PVR_C2 was -40.0 ml (ASP8302) versus -35.0 ml (placebo) and the difference between groups was -5.0 ml (p = 0.960). In males, functional and symptomatic outcomes improved, for example, maximum urine flow rate (Q_max ) and detrusor pressure at Q_max (P_det.Qmax ) increased (mean difference in change ASP8302 vs. placebo: 3.8 ml/s, p = 0.031 and 12.7 cm H₂ O, p = 0.034, respectively). Urinary incontinence episodes/24 h decreased in males with preexisting incontinence (mean difference: -0.35; p = 0.028). The incidence of adverse events was similar between study groups (ASP8302: 33.3%, placebo: 31.4%). In the included subjects, both baseline urine flow and bladder voiding pressure was low. Compared with PVR, simultaneous BVE measurements were more consistent between various methods (spontaneous vs. standardized bladder filling, catheterization vs. ultrasound [US]).

CONCLUSIONS

ASP8302 was safe and well tolerated in patients with UAB identified by nonurodynamic clinical criteria, but it did not show efficacy in the primary endpoint. However, in males it showed improvement of symptoms and functional parameters. BVE (using US) is a more optimal outcome measure than PVR in UAB.

Muscarinic Agonist Ameliorates Insulin Secretion in Wfs1-Deficient Mice

OBJECTIVES

Similar to patients with Wolfram syndrome and to heterozygous Wolframin1 (Wfs1) mutation carriers, Wfs1-deficient mice exhibit impaired glucose tolerance and lower plasma insulin levels. Muscarinic receptor 3 agonists have previously been shown to potentiate glucose-stimulated insulin secretion. Therefore, the aim of this study was to investigate insulin-secretion dynamics in Wfs1-deficient mice and evaluate carbachol, muscarinic agonist and the ability to ameliorate the insulin secretion deficits caused by the Wfs1 mutation.

METHODS

Wild-type Wfs1 heterozygous and Wfs1 mutant mice were used. Blood glucose was measured after glucose and carbachol administration. Insulin secretion was measured from serum using ELISA.

RESULTS

Glucose administration causes hyperglycemia in Wfs1-deficient mice due to decreased insulin secretion. This deficit is abolished by administration of the muscarinic agonist carbachol.

CONCLUSIONS

Activation of the muscarinic pathway to potentiate insulin secretion may present a target to manage diabetes resulting from Wfs1 deficiency.