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Translational Neuroscience 2015To investigate the effect of brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase (Trk) on potassium chloride cotransporter 2 (KCC2) in rats following...
PURPOSE
To investigate the effect of brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase (Trk) on potassium chloride cotransporter 2 (KCC2) in rats following nicotine withdrawal and the roles played by BDNF/Trk/KCC2 pathway in nicotine withdrawal-induced hyperalgesia.
METHODS
Seventy-eight rats were randomly assigned to five groups: control group (n = 12) without any treatment, normal saline group (NS group, n = 12) and nicotine withdrawal group (NW group, n = 30) receiving a subcutaneous injection of saline or nicotine for 7 days, respectively. The NW + dimethyl sulfoxide (DMSO) (n = 12) and NW+ Trk antagonist K252a groups (n = 12) received an intrathecal injection of DMSO (10 μl) and K252a (10 μg/10 μl) for 3 days after nicotine withdrawal, respectively. Nicotine withdrawal was precipitated by subcutaneous injection of nonselective and noncompetitive antagonist of nicotinic acetylcholine receptors mecamylamine. Pain was tested using thermal withdrawal latency (TWL). A Western blot was used to examine the expression of BDNF and KCC2.
RESULTS
The TWL was significantly decreased in NW group relative to control and NS groups ( < 0.01). Compared with the NW group, the NW+K252a group manifested a significantly higher latency ( < 0.01). The BDNF expression was increased and KCC2 was decreased in NW group compared with the control group ( < 0.01). K252a reduced KCC2 downregulation.
CONCLUSION
BDNF/Trk signaling may contribute to nicotine withdrawal-induced hyperalgesia via downregulation of KCC2.
PubMed: 28123805
DOI: 10.1515/tnsci-2015-0022 -
Archives of Toxicology Jun 2021Neonicotinoid pesticides, originally developed to target the insect nervous system, have been reported to interact with human receptors and to activate rodent neurons.... (Comparative Study)
Comparative Study
Neonicotinoid pesticides, originally developed to target the insect nervous system, have been reported to interact with human receptors and to activate rodent neurons. Therefore, we evaluated in how far these compounds may trigger signaling in human neurons, and thus, affect the human adult or developing nervous system. We used SH-SY5Y neuroblastoma cells as established model of nicotinic acetylcholine receptor (nAChR) signaling. In parallel, we profiled dopaminergic neurons, generated from LUHMES neuronal precursor cells, as novel system to study nAChR activation in human post-mitotic neurons. Changes of the free intracellular Ca concentration ([Ca]) were used as readout, and key findings were confirmed by patch clamp recordings. Nicotine triggered typical neuronal signaling responses that were blocked by antagonists, such as tubocurarine and mecamylamine. Pharmacological approaches suggested a functional expression of α7 and non-α7 nAChRs on LUHMES cells. In this novel test system, the neonicotinoids acetamiprid, imidacloprid, clothianidin and thiacloprid, but not thiamethoxam and dinotefuran, triggered [Ca] signaling at 10-100 µM. Strong synergy of the active neonicotinoids (at low micromolar concentrations) with the α7 nAChR-positive allosteric modulator PNU-120596 was observed in LUHMES and SH-SY5Y cells, and specific antagonists fully inhibited such signaling. To provide a third line of evidence for neonicotinoid signaling via nAChR, we studied cross-desensitization: pretreatment of LUHMES and SH-SY5Y cells with active neonicotinoids (at 1-10 µM) blunted the signaling response of nicotine. The pesticides (at 3-30 µM) also blunted the response to the non-α7 agonist ABT 594 in LUHMES cells. These data show that human neuronal cells are functionally affected by low micromolar concentrations of several neonicotinoids. An effect of such signals on nervous system development is a toxicological concern.
Topics: Calcium; Cell Line; Cell Line, Tumor; Dopaminergic Neurons; Dose-Response Relationship, Drug; Humans; Neonicotinoids; Neuroblastoma; Patch-Clamp Techniques; Pesticides; Receptors, Nicotinic; Signal Transduction
PubMed: 33778899
DOI: 10.1007/s00204-021-03031-1 -
Bioscience Reports Dec 2022M2 macrophages have been reported to be important in the progression of coronary artery disease (CAD). Thus, the present study aims at exploring the diagnostic value of...
BACKGROUND
M2 macrophages have been reported to be important in the progression of coronary artery disease (CAD). Thus, the present study aims at exploring the diagnostic value of M2 macrophage-associated genes in CAD.
METHODS
Transcriptome profile of CAD and control samples were downloaded from Gene Expression Omnibus database. The proportion of immune cells was analyzed using cell type identification by estimating relative subsets of RNA transcripts. Weighted Gene Co-expression Network Analysis (WGCNA) was carried out to screen the relevant module associated with M2 macrophages. Differential CAD and control samples of expressed genes (DEGs) were identified by the limma R package. Functional enrichment analysis by means of the clusterProfiler R package. Least absolute shrinkage and selection operator (LASSO) and random forest (RF) algorithms were carried out to select signature genes. Receiver operating curves (ROC) were plotted to evaluate the diagnostic value of selected signature genes. The expressions of potential diagnostic markers were validated by RT-qPCR. The ceRNA network of diagnostic biomarkers was constructed via miRwalk and Starbase database. CMap database was used to screen candidate drugs in the treatment of CAD by targeting diagnostic biomarkers.
RESULTS
A total of 166 M2 macrophage-associated genes were identified by WGCNA. By intersecting those genes with 879 DEGs, 53 M2 macrophage-associated DEGs were obtained in the present study. By LASSO, RF, and ROC analyses, C1orf105, CCL22, CRYGB, FRK, GAP43, REG1P, CALB1, and PTPN21 were identified as potential diagnostic biomarkers. RT-qPCR showed the consistent expression patterns of diagnostic biomarkers between GEO dataset and clinical samples. Perhexiline, alimemazine and mecamylamine were found to be potential drugs in the treatment of CAD.
CONCLUSION
We identified eight M2 macrophage-associated diagnostic biomarkers and candidate drugs for the CAD treatment.
Topics: Humans; Coronary Artery Disease; Gene Regulatory Networks; Gene Expression Profiling; Transcriptome; Macrophages; Biomarkers
PubMed: 36222281
DOI: 10.1042/BSR20221394 -
Addiction Biology May 2021Alcohol use disorder is a chronic, relapsing brain disorder causing substantial morbidity and mortality. Cholinergic interneurons (CIN) within the nucleus accumbens...
Alcohol use disorder is a chronic, relapsing brain disorder causing substantial morbidity and mortality. Cholinergic interneurons (CIN) within the nucleus accumbens (nAc) have been suggested to exert a regulatory impact on dopamine (DA) neurotransmission locally, and defects in CIN have been implied in several psychiatric disorders. The aim of this study was to investigate the role of CIN in regulation of basal extracellular levels of DA and in modulation of nAc DA release following ethanol administration locally within the nAc of male Wistar rats. Using reversed in vivo microdialysis, the acetylcholinesterase inhibitor physostigmine was administered locally in the nAc followed by addition of either the muscarinic acetylcholine (ACh) receptor antagonist scopolamine or the nicotinic ACh receptor antagonist mecamylamine. Further, ethanol was locally perfused in the nAc following pretreatment with scopolamine and/or mecamylamine. Lastly, ethanol was administered locally into the nAc of animals with accumbal CIN-ablation induced by anticholine acetyl transferase-saporin. Physostigmine increased accumbal DA levels via activation of muscarinic ACh receptors. Neither scopolamine and/or mecamylamine nor CIN-ablation altered basal DA levels, suggesting that extracellular DA levels are not tonically controlled by ACh in the nAc. In contrast, ethanol-induced DA elevation was prevented following coadministration of scopolamine and mecamylamine and blunted in CIN-ablated animals, suggesting involvement of CIN-ACh in ethanol-mediated DA signaling. The data presented in this study suggest that basal extracellular levels of DA within the nAc are not sustained by ACh, whereas accumbal CIN-ACh is involved in mediating ethanol-induced DA release.
Topics: Acetylcholine; Animals; Cholinergic Antagonists; Dopamine; Ethanol; Male; Mecamylamine; Microdialysis; Nicotinic Antagonists; Nucleus Accumbens; Rats; Rats, Wistar; Scopolamine; Ventral Tegmental Area
PubMed: 32789970
DOI: 10.1111/adb.12959 -
Developmental Biology Dec 2022We recently described calcium signaling in the appendicularian tunicate Oikopleura dioica during pre-gastrulation stages, and showed that regularly occurring calcium...
We recently described calcium signaling in the appendicularian tunicate Oikopleura dioica during pre-gastrulation stages, and showed that regularly occurring calcium waves progress throughout the embryo in a characteristic spatiotemporal pattern from an initiation site in muscle lineage blastomeres. Here, we have extended our observations to the period spanning from gastrulation to post-hatching stages. We find that repetitive Ca2+ waves persist throughout this developmental window, albeit with a gradual increase in frequency. The initiation site of the waves shifts from muscle cells at gastrulation and early tailbud stages, to the central nervous system at late tailbud and post-hatching stages, indicating a transition from muscle-driven to neurally driven events as tail movements emerge. At these later stages, both the voltage gated Na+ channel blocker tetrodotoxin (TTX) and the T-type Ca2+ channel blocker and nAChR antagonist mecamylamine eliminate tail movements. At late post-hatching stages, mecamylamine blocks Ca2+ signals in the muscles but not the central nervous system. Post-gastrulation Ca2+ signals also arise in epithelial cells, first in a haphazard pattern in scattered cells during tailbud stages, evolving after hatching into repetitive rostrocaudal waves with a different frequency than the nervous system-to-muscle waves, and insensitive to mecamylamine. The desynchronization of Ca2+ waves arising in different parts of the body indicates a shift from whole-body to tissue/organ-specific Ca2+ signaling dynamics as organogenesis occurs, with neurally driven Ca2+ signaling dominating at the later stages when behavior emerges.
Topics: Animals; Gastrulation; Urochordata; Calcium Signaling; Calcium; Mecamylamine
PubMed: 36162551
DOI: 10.1016/j.ydbio.2022.09.004 -
PloS One 2018Nicotine evokes chorda tympani (CT) taste nerve responses and an aversive behavior in Trpm5 knockout (KO) mice. The agonists and antagonists of nicotinic acetylcholine...
Nicotine evokes chorda tympani (CT) taste nerve responses and an aversive behavior in Trpm5 knockout (KO) mice. The agonists and antagonists of nicotinic acetylcholine receptors (nAChRs) modulate neural and behavioral responses to nicotine in wildtype (WT) mice, Trpm5 KO mice and rats. This indicates that nicotine evokes bitter taste by activating a Trpm5-dependent pathway and a Trpm5-independent but nAChR-dependent pathway. Rat CT responses to ethanol are also partially inhibited by nAChR blockers, mecamylamine and dihydro-β-erythroidine. This indicates that a component of the bitter taste of ethanol is also nAChR-dependent. However, at present the expression and localization of nAChR subunits has not been investigated in detail in taste receptor cells (TRCs). To this end, in situ hybridization, immunohistochemistry and q-RT-PCR techniques were utilized to localize nAChR subunits in fungiform and circumvallate TRCs in WT mice, Trpm5-GFP transgenic mice, nAChR KO mice, and rats. The expression of mRNAs for α7, β2 and β4 nAChR subunits was observed in a subset of rat and WT mouse circumvallate and fungiform TRCs. Specific α3, α4, α7, β2, and β4 antibodies localized to a subset of WT mouse circumvallate and fungiform TRCs. In Trpm5-GFP mice α3, α4, α7, and β4 antibody binding was observed in a subset of Trpm5-positive circumvallate TRCs. Giving nicotine (100 μg/ml) in drinking water to WT mice for 3 weeks differentially increased the expression of α3, α4, α5, α6, α7, β2 and β4 mRNAs in circumvallate TRCs to varying degrees. Giving ethanol (5%) in drinking water to WT mice induced an increase in the expression of α5 and β4 mRNAs in circumvallate TRCs with a significant decrease in the expression of α3, α6 and β2 mRNAs. We conclude that nAChR subunits are expressed in Trpm5-positive TRCs and their expression levels are differentially altered by chronic oral exposure to nicotine and ethanol.
Topics: Animals; In Situ Hybridization; Mice; Mice, Inbred C57BL; Mice, Transgenic; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Receptors, Nicotinic; TRPM Cation Channels; Taste Buds
PubMed: 29293602
DOI: 10.1371/journal.pone.0190465 -
Nicotine & Tobacco Research : Official... Nov 2021Smoking and the use of other nicotine-containing products is rewarding in humans. The self-administration of nicotine is also rewarding in male rats. However, it is...
INTRODUCTION
Smoking and the use of other nicotine-containing products is rewarding in humans. The self-administration of nicotine is also rewarding in male rats. However, it is unknown if there are sex differences in the reward-enhancing effects of nicotine self-administration and if the rewarding effects of nicotine change over time.
METHODS
Rats were prepared with catheters and intracranial self-stimulation (ICSS) electrodes to investigate the effects of nicotine and saline self-administration on reward function. A decrease in thresholds in the ICSS procedure reflects an enhancement of reward function. The ICSS parameters were determined before and after the self-administration sessions from days 1 to 10, and after the self-administration sessions from days 11 to 15.
RESULTS
During the first 10 days, there was no sex difference in nicotine intake, but during the last 5 days, the females took more nicotine than the males. During the first 10 days, nicotine self-administration did not lower the brain reward thresholds but decreased the response latencies. During the last 5 days, nicotine lowered the reward thresholds and decreased the response latencies. An analysis with the 5-day averages (days 1-5, 6-10, and 11-15) showed that the reward enhancing and stimulatory effects of nicotine increased over time. There were no sex differences in the reward-enhancing and stimulatory effects of nicotine. The nicotinic receptor antagonist mecamylamine diminished the reward-enhancing and stimulatory effects of nicotine.
CONCLUSION
These findings indicate that the rewarding effects of nicotine self-administration increase over time, and there are no sex differences in the reward-enhancing effects of nicotine self-administration in rats.
IMPLICATIONS
This study investigated the rewarding effect of nicotine and saline self-administration in male and female rats. The self-administration of nicotine, but not saline, enhanced brain reward function and had stimulatory effects. The rewarding effects of nicotine increased over time in the males and the females. Despite that the females had a higher level of nicotine intake than the males, the reward-enhancing effects of nicotine self-administration were the same. These findings suggest that in new tobacco and e-cigarette users, nicotine's rewarding effects might increase quickly, and a higher level of nicotine use in females might not translate into greater rewarding effects.
Topics: Animals; Electronic Nicotine Delivery Systems; Female; Male; Nicotine; Rats; Rats, Wistar; Reward; Self Stimulation
PubMed: 33987656
DOI: 10.1093/ntr/ntab097 -
Drug and Alcohol Dependence Mar 2017Although both men and women use e-cigarettes, most preclinical nicotine research has focused on its effects in male rodents following injection. The goals of the present...
BACKGROUND
Although both men and women use e-cigarettes, most preclinical nicotine research has focused on its effects in male rodents following injection. The goals of the present study were to develop an effective e-cigarette nicotine delivery system, to compare results to those obtained after subcutaneous (s.c.) injection, and to examine sex differences in the model.
METHODS
Hypothermia and locomotor suppression were assessed following aerosol exposure or s.c. injection with nicotine in female and male mice. Subsequently, plasma and brain concentrations of nicotine and cotinine were measured.
RESULTS
Passive exposure to nicotine aerosol produced concentration-dependent and mecamylamine reversible hypothermic and locomotor suppressant effects in female and male mice, as did s.c. nicotine injection. In plasma and brain, nicotine and cotinine concentrations showed dose/concentration-dependent increases in both sexes following each route of administration. Sex differences in nicotine-induced hypothermia were dependent upon route of administration, with females showing greater hypothermia following aerosol exposure and males showing greater hypothermia following injection. In contrast, when they occurred, sex differences in nicotine and cotinine levels in brain and plasma consistently showed greater concentrations in females than males, regardless of route of administration.
DISCUSSION
In summary, the e-cigarette exposure device described herein was used successfully to deliver pharmacologically active doses of nicotine to female and male mice. Further, plasma nicotine concentrations following exposure were similar to those after s.c. injection with nicotine and within the range observed in human smokers. Future research on vaped products can be strengthened by inclusion of translationally relevant routes of administration.
Topics: Aerosols; Animals; Brain; Cotinine; Dose-Response Relationship, Drug; Drug Delivery Systems; Electronic Nicotine Delivery Systems; Female; Injections, Subcutaneous; Male; Mecamylamine; Mice; Mice, Inbred ICR; Motor Activity; Nicotine; Nicotinic Agonists; Nicotinic Antagonists; Sex Characteristics
PubMed: 28157590
DOI: 10.1016/j.drugalcdep.2016.12.004 -
Mediators of Inflammation 2020Breast cancer results from a complex interplay of genetics and environment that alters immune and inflammatory systems to promote tumorigenesis. Obesity and cigarette...
Breast cancer results from a complex interplay of genetics and environment that alters immune and inflammatory systems to promote tumorigenesis. Obesity and cigarette smoking are well-known risk factors associated breast cancer development. Nicotine known to decrease inflammatory signals also modulates immune responses that favor breast cancer development. However, the mechanisms by which nicotine and obesity contribute to breast cancer remain poorly understood. In this study, we examined potential mechanisms by which nicotine (NIC) and high-fat diet (HFD) promote growth of HCC70 and HCC1806 xenografts from African American (AA) triple negative (TN) breast cancer cells. Immunodeficient mice fed on HFD and treated with NIC generated larger HCC70 and HCC1806 tumors when compared to NIC or HFD alone. Increased xenograft growth in the presence of NIC and HFD was accompanied by higher levels of tissue-resident macrophage markers and anti-inflammatory cytokines including IL4, IL13, and IL10. We further validated the involvement of these players by and experiments. We found a proinflammatory milieu with increased expression of IL6 and IL12 in xenografts with HFD. In addition, nicotine or nicotine plus HFD increased a subset of mammary cancer stem cells (MCSCs) and key adipose browning markers CD137 and TMEM26. Interestingly, there was upregulation of stress-induced pp38 MAPK and pERK1/2 in xenografts exposed to HFD alone or nicotine plus HFD. Scratch-wound assay showed marked reduction in proliferation/migration of nicotine and palmitate-treated breast cancer cells with mecamylamine (MEC), a nicotine acetylcholine receptor (nAchR) antagonist. Furthermore, xenograft development in immune-deficient mice, fed HFD plus nicotine, was reduced upon cotreatment with MEC and SB 203580, a pp38MAPK inhibitor. Our study demonstrates the presence of nicotine and HFD in facilitating an anti-inflammatory tumor microenvironment that influences breast tumor growth. This study also shows potential efficacy of combination therapy in obese breast cancer patients who smoke.
Topics: Animal Feed; Animals; Anti-Inflammatory Agents; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Diet, High-Fat; Female; Humans; Imidazoles; Inflammasomes; Inflammation; Mammary Neoplasms, Animal; Mecamylamine; Mice; Neoplasm Transplantation; Neoplastic Stem Cells; Nicotine; Oxidative Stress; Pyridines; Up-Regulation; p38 Mitogen-Activated Protein Kinases
PubMed: 33414685
DOI: 10.1155/2020/5239419 -
Genes, Brain, and Behavior Apr 2023Nicotine is the reinforcing ingredient in tobacco. Following chronic exposure, sudden cessation of nicotine use produces negative symptoms of withdrawal that contribute...
Nicotine is the reinforcing ingredient in tobacco. Following chronic exposure, sudden cessation of nicotine use produces negative symptoms of withdrawal that contribute to dependence. The molecular mechanisms underlying nicotine withdrawal behaviors, however, are poorly understood. Using recombinant inbred mice, chronic nicotine was delivered by minipump and withdrawal induced using mecamylamine. Somatic signs of withdrawal, and anxiety-like behavior using elevated plus maze, were then assessed. Interval mapping was used to identify associations between genetic variation and withdrawal behaviors, and with basal gene expression. Differential gene expression following nicotine exposure and withdrawal was also assessed in progenitor mice using microarrays. Quantitative trait loci mapping identified chromosome intervals with significant genetic associations to somatic signs of withdrawal or withdrawal-induced anxiety-like behavior. Using bioinformatics, and association with basal gene expression in nucleus accumbens, we implicated Rb1, Bnip3l, Pnma2, Itm2b, and Kif13b as candidate genes for somatic signs of withdrawal, and Galr1, which showed trans-regulation from a region of chromosome 14 that was associated with somatic signs of withdrawal. Candidate genes within the chromosome 9 region associated with anxiety-like withdrawal behavior included Dixdc1, Ncam1, and Sorl1. Bioinformatics identified six genes that were also significantly associated with nicotine or alcohol traits in recent human genome-wide association studies. Withdrawal-associated somatic signs and anxiety-like behavior had strong non-overlapping genetic associations, respectively, with regions of chromosome 14 and chromosome 9. Genetic, behavioral and gene expression correlations, and bioinformatics analysis identified several candidate genes that may represent novel molecular targets for modulating nicotine withdrawal symptoms.
Topics: Mice; Animals; Humans; Nicotine; Mice, Inbred DBA; Genome-Wide Association Study; Mice, Inbred C57BL; Substance Withdrawal Syndrome; LDL-Receptor Related Proteins; Membrane Transport Proteins; Kinesins; Intracellular Signaling Peptides and Proteins; Membrane Proteins
PubMed: 36781202
DOI: 10.1111/gbb.12844