Treatment with LPS plus INF-γ induces the expression and function of muscarinic acetylcholine receptors, modulating NIH3T3 cell proliferation: participation of NOS and COX

Paraprobiotics strains accelerate wound repair by stimulating re-epithelialization of NIH-3T3 cells, decreasing inflammatory response and oxidative stress

The present study aimed to evaluate the potential and specificity of the inflammatory and antioxidant response of Microbe-Associated Molecular Patterns (MAMPs) in NIH-3T3 fibroblast cells, as well as in the healing process of skin wounds. Cells (NIH-3T3) were cultivated in supplemented specific medium. NIH-3T3 cells were treated with MAMPs (Bifidobacterium lactis or Lactobacillus casei or Lactobacillus gasseri or Lactobacillus paracasei or Streptococcus thermophilus), at two concentrations and insulted with LPS or H₂O₂. Cell viability, myeloperoxidase activity, nitrite/nitrate, oxidative damage and inflammatory parameters were measured. In addition, scratch assay was performed. Significant scratch closure was observed after 24 h and 48 h, and the effect of 0.1 g/mL MAMPs on wound healing was found to be highly statistically significant. In the viability cellular assay, Lactobacillus showed better response in 0.1 g/mL dose, whereas B. lactis and S. thermophilus showed better response in 0.01 g/mL dose. There was reduction in IL-6 and IL-1β levels in all treatments insulted with LPS. MAMP's showed preventive efficacy in reducing the effects caused by LPS. The MAMP's action in decreasing the production of ROS, inflammatory activity and increasing cell viability, besides significant cell proliferation during wound healing processes suggests remodeling mechanisms and new possibilities for wound healing.

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.

Uterine Inflammation Changes the Expression of Cholinergic Neurotransmitters and Decreases the Population of AChE-Positive, Uterus-Innervating Neurons in the Paracervical Ganglion of Sexually Mature Gilts

Simple Summary

Endometritis, both with non-infectious and infectious backgrounds, is one of the most prevalent pathological states among domestic animals. In animals, it generates severe economic problems, including lowered reproductive indices and rising medical treatment costs, and in women, it might lead to severe fertility impairment. In order to determine how the autonomic nervous system responds to such a pathological state, an experimental group of pigs were treated with Escherichia coli injection into the uterine horns, and several ganglions responsible for innervation of this organ were examined, including the paracervical ganglion located on both sides of the broad ligament of the uterus. The results clearly showed a strong impact of the inflammation on the chemical coding of neurons, some even synthesizing neurotransmitters de novo such as the GAL-expressing perikarya. Additionally, applied injections decreased the number of parasympathetic, acetylcholinesterase-expressing neurons implying the importance of the cholinergic population to keep the inflammation under control. The obtained data serve as a basis for the future implementation of modern treatment and enhancements in animal breeding.

Abstract

The focus of this study was based on examining the impact of endometritis on the chemical coding of the paracervical ganglion (PCG) perikaryal populations supplying pig uterus. Four weeks after the injection of Fast Blue retrograde tracer into uterine horns, either the Escherichia coli (E. coli) suspension or saline solution was applied to both horns. Laparotomy treatment was performed for the control group. Uterine cervices containing PCG were extracted on the eighth day after previous treatments. Subsequent macroscopic and histopathologic examinations acknowledged the severe form of acute endometritis in the E. coli-treated gilts, whereas double-labeling immunofluorescence procedures allowed changes to be analyzed in the PCG perikaryal populations coded with vesicular acetylcholine transporter (VAChT) and/or somatostatin (SOM), vasoactive intestinal polypeptide (VIP), a neuronal isoform of nitric oxide synthase (nNOS), galanin (GAL). The acetylcholinesterase (AChE) detection method was used to check for the presence and changes in the expression of this enzyme and further confirm the presence of cholinergic perikarya in PCG. Treatment with E. coli resulted in an increase in VAChT+/VIP+, VAChT+/VIP−, VAChT+/SOM+, VAChT+/SOM−, VAChT+/GAL− and VAChT+/nNOS− PCG uterine perikarya. An additional increase was noted in the non-cholinergic VIP-, SOM- and nNOS-immunopositive populations, as well as a decrease in the number of cholinergic nNOS-positive perikarya. Moreover, the population of cholinergic GAL-expressing perikarya that appeared in the E. coli-injected gilts and E. coli injections lowered the number of AChE-positive perikarya. The neurochemical characteristics of the cholinergic uterine perikarya of the PCG were altered and influenced by the pathological state (inflammation of the uterus). These results may indicate the additional influence of such a state on the functioning of this organ.

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-KD^HOM) 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-KD^HOM 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-KD^HOM mice. However, treatment with PNU 282987, a selective α7 nicotinic receptor agonist, restored VAChT-KD^HOM 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-KD^HOM 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.

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.

Neuroimmune Pathophysiology in Asthma

Asthma is a chronic inflammation of lower airway disease, characterized by bronchial hyperresponsiveness. Type I hypersensitivity underlies all atopic diseases including allergic asthma. However, the role of neurotransmitters (NT) and neuropeptides (NP) in this disease has been less explored in comparison with inflammatory mechanisms. Indeed, the airway epithelium contains pulmonary neuroendocrine cells filled with neurotransmitters (serotonin and GABA) and neuropeptides (substance P[SP], neurokinin A [NKA], vasoactive intestinal peptide [VIP], Calcitonin-gene related peptide [CGRP], and orphanins-[N/OFQ]), which are released after allergen exposure. Likewise, the autonomic airway fibers produce acetylcholine (ACh) and the neuropeptide Y(NPY). These NT/NP differ in their effects; SP, NKA, and serotonin exert pro-inflammatory effects, whereas VIP, N/OFQ, and GABA show anti-inflammatory activity. However, CGPR and ACh have dual effects. For example, the ACh-M3 axis induces goblet cell metaplasia, extracellular matrix deposition, and bronchoconstriction; the CGRP-RAMP1 axis enhances Th2 and Th9 responses; and the SP-NK1R axis promotes the synthesis of chemokines in eosinophils, mast cells, and neutrophils. In contrast, the ACh-α7nAChR axis in ILC2 diminishes the synthesis of TNF-α, IL-1, and IL-6, attenuating lung inflammation whereas, VIP-VPAC1, N/OFQ-NOP axes cause bronchodilation and anti-inflammatory effects. Some NT/NP as 5-HT and NKA could be used as biomarkers to monitor asthma patients. In fact, the asthma treatment based on inhaled corticosteroids and anticholinergics blocks M3 and TRPV1 receptors. Moreover, the administration of experimental agents such as NK1R/NK2R antagonists and exogenous VIP decrease inflammatory mediators, suggesting that regulating the effects of NT/NP represents a potential novel approach for the treatment of asthma.

Escherichia Coli -induced Inflammation Changes the Expression of Acetylcholine Receptors (M2R, M3R, and α-7 nAChR) in the Pig Uterus

Introduction

The influence of inflammation on the patterns of muscarinic 2 and 3 receptor subtypes (M2R and M3R), and α-7 nicotinic acetylcholine receptor (α-7 nAChR) expression in the porcine uterus was investigated.

Material and Methods

On day three of the oestrous cycle of gilts aged 7-8 months with body weight 90-120 kg, either an E. coli suspension (E. coli group, n = 5) or saline (Sal group, n = 5) was administered into the uterine horns via laparotomy or only laparotomy was performed on control swine (Ctrl group, n = 5). After eight days, and the onset of severe acute endometritis in the E. coli group, the uterine mRNA and protein receptor expression levels were determined using real-time RT-PCR and Western blotting, respectively, with receptor localisation by immunofluorescence.

Results

The studied receptors were in the luminal epithelium, glands, blood vessels, and myometrial muscle cells of all gilts. The M2R mRNA level was lower in the inflamed endometrium compared to the Ctrl and Sal groups. Also in this tissue, the expression of M3R mRNA and protein was lower than in the Ctrl and Sal groups. The M3R protein level in the bacterially challenged myometrium was found to be increased compared to unadministered groups. In the endometrium of the E. coli group, the α-7 nAChR protein level was lower than in the Sal group, and in the myometrium it was reduced in relation to both the other groups. P values were ≤ 0.05 in all cases.

Conclusion

Inflammation causes alterations in the M2R, M3R, and α-7 nAChR expression in the pig uterus, suggesting their significance in the course and repercussions of uterine inflammation.

An In Vivo Pharmacological Screen Identifies Cholinergic Signaling as a Therapeutic Target in Glial-Based Nervous System Disease

The role that glia play in neurological disease is poorly understood but increasingly acknowledged to be critical in a diverse group of disorders. Here we use a simple genetic model of Alexander disease, a progressive and severe human degenerative nervous system disease caused by a primary astroglial abnormality, to perform an in vivo screen of 1987 compounds, including many FDA-approved drugs and natural products. We identify four compounds capable of dose-dependent inhibition of nervous system toxicity. Focusing on one of these hits, glycopyrrolate, we confirm the role for muscarinic cholinergic signaling in pathogenesis using additional pharmacologic reagents and genetic approaches. We further demonstrate that muscarinic cholinergic signaling works through downstream Gαq to control oxidative stress and death of neurons and glia. Importantly, we document increased muscarinic cholinergic receptor expression in Alexander disease model mice and in postmortem brain tissue from Alexander disease patients, and that blocking muscarinic receptors in Alexander disease model mice reduces oxidative stress, emphasizing the translational significance of our findings. We have therefore identified glial muscarinic signaling as a potential therapeutic target in Alexander disease, and possibly in other gliopathic disorders as well.

SIGNIFICANCE STATEMENT

Despite the urgent need for better treatments for neurological diseases, drug development for these devastating disorders has been challenging. The effectiveness of traditional large-scale in vitro screens may be limited by the lack of the appropriate molecular, cellular, and structural environment. Using a simple Drosophila model of Alexander disease, we performed a moderate throughput chemical screen of FDA-approved drugs and natural compounds, and found that reducing muscarinic cholinergic signaling ameliorated clinical symptoms and oxidative stress in Alexander disease model flies and mice. Our work demonstrates that small animal models are valuable screening tools for therapeutic compound identification in complex human diseases and that existing drugs can be a valuable resource for drug discovery given their known pharmacological and safety profiles.