Molecular mechanisms of synergy of corneal muscarinic and nicotinic acetylcholine receptors in upregulation of E-cadherin expression.

Corneal epithelial erosion is one of the most common problems in clinical ophthalmology. Despite significant progress in understanding how the cornea heals, clinically available pharmacological therapies that can promote repair and prevent visual complications remain limited. We have recently demonstrated that the acetylcholine (ACh) axis of corneal epithelium plays an important role in regulation and coordination of distinct activities of corneal epithelial cells (CEC) mediating re-epithelialization, but mechanisms remained unclear.

The acetylcholine signaling network of corneal epithelium and its role in regulation of random and directional migration of corneal epithelial cells.

Purpose: Because cholinergic drugs are used in ophthalmology and cholinergic stimulation has been shown to facilitate epithelialization of mucocutaneous wounds, we performed a systematic analysis of components of the cholinergic network of human and murine corneal epithelial cells (CECs) and determined the role of autocrine and paracrine acetylcholine (ACh) in regulation of CEC motility.

Methods: We investigated the expression of ACh receptors at the mRNA and protein levels in human immortalized CECs, localization of cholinergic molecules in normal and wounded murine cornea, and the effects of cholinergic drugs on CEC directional and random migration in vitro, intercellular adhesion, and expression of integrin αV and E-cadherin.

Results: We demonstrated that corneal epithelium expresses the ACh-synthesizing enzyme choline acetyltransferase, the ACh-degrading enzyme acetylcholinesterase, two muscarinic ACh receptors (mAChRs), M3 and M4, and several nicotinic ACh receptors (nAChRs), including both α7- and α9-made homomeric nAChRs and predominantly the α3β2±α5 subtype of heteromeric nAChRs.

Targeting histone deacetylase in lung cancer for early diagnosis: (18)F-FAHA PET/CT imaging of NNK-treated A/J mice model.

Elevated levels of histone deacetylases (HDACs) have been indicated in the development of some cancers. HDAC has been imaged using (18)F-FAHA and may serve as a marker to study epigenetics. We report evaluation of (18)F-FAHA as a probe in the early diagnosis of lung cancer using (18)F-FAHA PET/CT studies of A/J mice treated with NNK.

Anti-inflammatory effects of the nicotinergic peptides SLURP-1 and SLURP-2 on human intestinal epithelial cells and immunocytes.

A search for novel and more efficient therapeutic modalities of inflammatory bowel disease (IBD) is one of the most important tasks of contemporary medicine. The anti-inflammatory action of nicotine in IBD might be therapeutic, but its toxicity due to off-target and nonreceptor effects limited its use and prompted a search for nontoxic nicotinergic drugs. We tested the hypothesis that SLURP-1 and -2--the physiological nicotinergic substances produced by the human intestinal epithelial cells (IEC) and immunocytes--can mimic the anti-inflammatory effects of nicotine.

Is Grover's disease an autoimmune dermatosis?

Grover's disease (GD) is a transient or persistent, monomorphous, papulovesicular, asymptomatic or pruritic eruption classified as non-familial acantholytic disorder. Contribution of autoimmune mechanisms to GD pathogenesis remains controversial. The purpose of this study was to investigate antibody-mediated autoimmunity in 11 patients with GD, 4 of which were positive for IgA and/or IgG antikeratinocyte antibodies by indirect immunofluorescence.

The tobacco carcinogen nitrosamine induces a differential gene expression response in tumour susceptible A/J and resistant C3H mouse lungs.

The nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), an important carcinogen found in tobacco products, causes lung cancer in genetically susceptible animals. In addition to mutations of the K-Ras gene, NNK has non-mutagenic effects that include alterations in gene expression and immunomodulation in the lung. Here we report the identification of two gene sets associated with NNK-induced pulmonary tumourigenesis.

Muscle sarcomas and alopecia in A/J mice chronically treated with nicotine.

Aims: To evaluate the pathobiologic effects of long-term treatment with nicotine of A/J mice susceptible to tobacco-induced lung carcinogenesis.

Main Methods: Experimental group of mice received subcutaneous injections of the LD(50) dose of (-)nicotine hydrogen tartrate of 3 mg/kg/day, 5 days per week for 24 months, and control group received the vehicle phosphate-buffered saline.

Key Findings: Nicotine treated mice, 78.

Cytokine-induced alterations of α7 nicotinic receptor in colonic CD4 T cells mediate dichotomous response to nicotine in murine models of Th1/Th17- versus Th2-mediated colitis.

Ulcerative colitis (UC) and Crohn's disease (CD) are two forms of chronic inflammatory bowel disease. CD4 T cells play a central role in the pathogenesis of both diseases. Smoking affects both UC and CD but with opposite effects, ameliorating UC and worsening CD.

Upregulation of nuclear factor-kappaB expression by SLURP-1 is mediated by alpha7-nicotinic acetylcholine receptor and involves both ionic events and activation of protein kinases.

SLURP-1 (secreted mammalian Ly-6/urokinase plasminogen activator receptor-related protein-1) is a novel auto/paracrine cholinergic peptide that can bind to α(7)-nicotinic acetylcholine receptor (nAChR), a high Ca(2+)-permeable ion channel coupled to regulation of nuclear factor-κB (NF-κB) expression. Elucidation of intracellular signaling events elicited by SLURP-1 is crucial for understanding the molecular mechanism of functioning of this novel hormone-like peptide that alters vital cell functions and can protect from tumorigenic transformation. In this study, we sought to dissect out the role of α(7)-nAChR in mediating the biologic effects of recombinant SLURP-1 on the immortalized line of human oral keratinocytes Het-1A.

Coupling of ionic events to protein kinase signaling cascades upon activation of alpha7 nicotinic receptor: cooperative regulation of alpha2-integrin expression and Rho kinase activity.

Defining the signaling mechanisms and effector proteins mediating phenotypic and mechanical plasticity of keratinocytes (KCs) during wound epithelialization is one of the major goals in epithelial cell biology. The acetylcholine (ACh)-gated ion channels, or nicotinic ACh receptors (nAChRs), mediate the nicotinergic signaling that controls crawling locomotion of KCs. To elucidate relative contributions of the ionic and protein kinase-mediated events elicited due to activation of alpha7 nAChRs, we quantitated expression of alpha2-integrin gene at the mRNA and protein levels and also measured Rho kinase activity in KCs stimulated with the alpha7 agonist AR-R17779 while blocking the Na+ or Ca2+ entry and/or inhibiting signaling kinases.

Superhigh-sensitivity photothermal monitoring of individual cell response to antitumor drug.

We describe and explore the capability of a photothermal (PT) assay with modified schematics for highly sensitive detection of individual cell response to antitumor drug impact in vitro. Specifically, we used the nonlinear differential PT test to measure distinctive changes of specific PT parameters after exposure of KB3 carcinoma cells to the antitumor drug vinblastine in the broad concentration range of 10(-10) to 300 nM. Verification of the PT assay was performed by comparison with multidrug-resistant cells and comparison with conventional assays evaluating cell viability, cytochrome c release, apoptosis induction, and cell size.