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1.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(8): 1184-1191, 2020 Aug 30.
Artigo em Chinês | MEDLINE | ID: mdl-32895175

RESUMO

OBJECTIVE: To construct a HIV-1 gp120 transgenic mouse model (gp120+) with α7 nicotinic acetylcholine receptor (α7nAChR) gene knockout. METHODS: The α7nAChR gene knockout mice (α7R-/-) were crossed with HIV-1gp120 transgenic mice (gp120+) to generate F1 generation mice. We selected the F1 mice with the genotype of α7R+/-/gp120+ to mate to obtain the F2 mice. The genotypes of the F3 mice were identified by PCR, and the protein expressions in the double transgenic animal model was analyzed by immunohistochemistry. BV2 cells were treated with gp120 protein and α7nAChR inhibitor, and the expressions of IL-1ß and TNF-α were detected using ELISA. RESULTS: The results of PCR showed the bands of the expected size in F3 mice. Two F3 mice with successful double gene editing (α7R-/-/gp120+) were obtained, and immunohistochemistry showed that the brain tissue of the mice did not express α7 nAChR but with high gp120 protein expression. In the in vitro cell experiment, treatment with gp120 promoted the secretion of IL-1ß and TNF-α in BV2 cells, while inhibition of α7nAChR significantly decreased the expression of IL-1ß and TNF-α (P < 0.001). CONCLUSIONS: By mating gp120 Tg mice with α7R-/- mice, we obtained gp120 transgenic mice with α7nAChR gene deletion, which serve as a new animal model for exploring the role of α7nAChR in gp120-induced neurotoxicity.


Assuntos
Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Modelos Animais de Doenças , Glicoproteínas , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Fator de Necrose Tumoral alfa
2.
Mol Pharmacol ; 98(2): 168-180, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32474444

RESUMO

The two major nicotinic acetylcholine receptors (nAChRs) in the brain are the α4ß2 and α7 subtypes. A "methyl scan" of the pyrrolidinium ring was used to detect differences in nicotine's interactions with these two receptors. Each methylnicotine was investigated using voltage-clamp and radioligand binding techniques. Methylation at each ring carbon elicited unique changes in nicotine's receptor interactions. Replacing the 1'-N-methyl with an ethyl group or adding a second 1'-N-methyl group significantly reduced interaction with α4ß2 but not α7 receptors. The 2'-methylation uniquely enhanced binding and agonist potency at α7 receptors. Although 3'- and 5'-trans-methylations were much better tolerated by α7 receptors than α4ß2 receptors, 4'-methylation decreased potency and efficacy at α7 receptors much more than at α4ß2 receptors. Whereas cis-5'-methylnicotine lacked agonist activity and displayed a low affinity at both receptors, trans-5'-methylnicotine retained considerable α7 receptor activity. Differences between the two 5'-methylated analogs of the potent pyridyl oxymethylene-bridged nicotine analog A84543 were consistent with what was found for the 5'-methylnicotines. Computer docking of the methylnicotines to the Lymnaea acetylcholine binding protein crystal structure containing two persistent waters predicted most of the changes in receptor affinity that were observed with methylation, particularly the lower affinities of the cis-methylnicotines. The much smaller effects of 1'-, 3'-, and 5'-methylations and the greater effects of 2'- and 4'-methylations on nicotine α7 nAChR interaction might be exploited for the design of new drugs based on the nicotine scaffold. SIGNIFICANCE STATEMENT: Using a comprehensive "methyl scan" approach, we show that the orthosteric binding sites for acetylcholine and nicotine in the two major brain nicotinic acetylcholine receptors interact differently with the pyrrolidinium ring of nicotine, and we suggest reasons for the higher affinity of nicotine for the heteromeric receptor. Potential sites for nicotine structure modification were identified that may be useful in the design of new drugs targeting these receptors.


Assuntos
Nicotina/análogos & derivados , Piridinas/síntese química , Receptores Nicotínicos/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Sítios de Ligação , Masculino , Metilação , Simulação de Acoplamento Molecular , Estrutura Molecular , Nicotina/química , Piridinas/química , Piridinas/farmacologia , Ratos , Relação Estrutura-Atividade , Xenopus laevis
3.
Psychopharmacology (Berl) ; 237(6): 1723-1735, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32162104

RESUMO

RATIONALE: Working memory deficits are present in schizophrenia (SZ) but remain insufficiently resolved by medications. Similar cognitive dysfunctions can be produced acutely in animals by elevating brain levels of kynurenic acid (KYNA). KYNA's effects may reflect interference with the function of both the α7 nicotinic acetylcholine receptor (α7nAChR) and the glycineB site of the NMDA receptor. OBJECTIVES: The aim of the present study was to examine, using pharmacological tools, the respective roles of these two receptor sites on performance in a delayed non-match-to-position working memory (WM) task (DNMTP). METHODS: DNMTP consisted of 120 trials/session (5, 10, and 15 s delays). Rats received two doses (25 or 100 mg/kg, i.p.) of L-kynurenine (KYN; bioprecursor of KYNA) or L-4-chlorokynurenine (4-Cl-KYN; bioprecursor of the selective glycineB site antagonist 7-Cl-kynurenic acid). Attenuation of KYN- or 4-Cl-KYN-induced deficits was assessed by co-administration of galantamine (GAL, 3 mg/kg) or PAM-2 (1 mg/kg), two positive modulators of α7nAChR function. Reversal of 4-Cl-KYN-induced deficits was examined using D-cycloserine (DCS; 30 mg/kg), a partial agonist at the glycineB site. RESULTS: Both KYN and 4-Cl-KYN administration produced dose-related deficits in DNMTP accuracy that were more severe at the longer delays. In KYN-treated rats, these deficits were reversed to control levels by GAL or PAM-2 but not by DCS. In contrast, DCS eliminated performance deficits in 4-Cl-KYN-treated animals. CONCLUSIONS: These experiments reveal that both α7nAChR and NMDAR activity are necessary for normal WM accuracy. They provide substantive new support for the therapeutic potential of positive modulators at these two receptor sites in SZ and other major brain diseases.


Assuntos
Encéfalo/metabolismo , Memória de Curto Prazo/fisiologia , Desempenho Psicomotor/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Analgésicos/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Ácido Cinurênico/farmacologia , Cinurenina/farmacologia , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Nicotina/farmacologia , Desempenho Psicomotor/efeitos dos fármacos , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/agonistas , Receptor Nicotínico de Acetilcolina alfa7/agonistas
4.
Gene ; 744: 144616, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32222531

RESUMO

AIM: The purpose of this study was to investigate the possible effects of Myrtus communis subsp. communis (MC) on cognitive impairment in ovariectomized diabetic rats. MATERIAL AND METHOD: Female Sprague-Dawley rats were divided into 5 groups consisting of 15 rats each; Control (C), Diabetes (D), Ovariectomy and diabetes (OVX + D), Ovariectomy, diabetes and donepezil (OVX + D + Don), Ovariectomy, diabetes and Myrtus communis subsp. communis (OVX + D + MC). Blood glucose measurements were made at the beginning and end of the experiments. The animals underwent the novel object recognition test (NORT) and their performance was evaluated. In hippocampal tissues; amyloid beta (Aß) and neprilysin levels, acetylcholinesterase (AChE), and choline acetyltransferase (ChAT) activities, polysialylated neural cell adhesion molecule (PSA-NCAM), α7 subunit of neuronal nicotinic acetylcholine receptor (α7-nAChR) and brain derived neurotrophic factor (BDNF) gene expressions were examined. RESULTS: Animals with ovariectomy and diabetes showed increased levels of blood glucose, AChE activity and Aß levels, and decreased neprilysin levels, ChAT activity, α7-nAChR, PSA-NCAM and BDNF gene expressions in parallel with a decrease in NORT performance score. On the other hand, in the MC-treated OVX + D group, there was a significant decrease observed in blood glucose levels and AChE activities while there was improvement in NORT performances and an increase in hippocampal ChAT activity, neprilysin levels, α7-nAChR, PSA-NCAM and BDNF expressions. CONCLUSION: These results suggest that MC extract could improve cognitive and neuronal functions with its anticholinesterase and antihyperglycemic properties.


Assuntos
Cognição/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Myrtus , Fitoterapia , Acetilcolinesterase/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Glicemia/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Colina O-Acetiltransferase/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/psicologia , Feminino , Hipocampo/metabolismo , Neprilisina/metabolismo , Molécula L1 de Adesão de Célula Nervosa/genética , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Ovariectomia , Extratos Vegetais/uso terapêutico , Ratos Sprague-Dawley , Ácidos Siálicos/genética , Ácidos Siálicos/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
5.
J Med Chem ; 63(6): 2974-2985, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32101438

RESUMO

The affinity of α-conotoxins, a class of nicotinic acetylcholine receptor (nAChR) peptide inhibitors, can be enhanced by dendrimerization. It has been hypothesized that this improvement arose from simultaneous binding of the α-conotoxins to several spatially adjacent sites. We here engineered several α-conotoxin dimers using a linker length compatible between neighboring binding sites on the same receptor. Remarkably, the dimer of α-conotoxin PeIA compared to the monomer displayed an increase in potency by 11-fold (IC50 = 1.9 nM) for the human α9α10 nAChR. The dimerization of α-conotoxin RgIA# resulted in a dual inhibitor that targets both α9α10 and α7 nAChR subtypes with an IC50 = ∼50 nM. The RgIA# dimer is therapeutically interesting because it is the first dual inhibitor that potently and selectively inhibits these two nAChR subtypes, which are both involved in the etiology of several cancers. We propose that the dimerization of α-conotoxins is a simpler and efficient alternative strategy to dendrimers for enhancing the activity of α-conotoxins.


Assuntos
Conotoxinas/metabolismo , Antagonistas Nicotínicos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Receptores Nicotínicos/metabolismo , Humanos , Modelos Moleculares , Antagonistas Nicotínicos/química , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/antagonistas & inibidores , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
6.
Microvasc Res ; 129: 103975, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31926201

RESUMO

Microvascular injury is a common pathological process in ischemia-reperfusion injury. Endothelial progenitor cells (EPCs) are vital cells for angiogenesis and endothelial repair. These cells can home to injury sites and secrete angiogenic growth factors. α7nAChRs are pivotal in cholinergic angiogenesis, which is associated with endothelial cells and EPCs. Our study was designed to determine whether activating α7nAChRs enhances the function of EPCs and to explore the underlying mechanism. EPCs were derived from the bone marrow of male Sprague-Dawley rats and treated with an α7nAChR agonist (PNU282987), an α7nAChR antagonist (MLA) and a JAK2 antagonist (AG490). We then assayed the angiogenic abilities of the EPCs, including proliferation ability, adhesion ability, migration ability and in vitro tube formation ability. The levels of total JAK2 (t-JAK2), phosphorylated JAK2 (p-JAK2), total STAT3 (t-STAT3) and phosphorylated STAT3 (p-STAT3) were estimated by western blot analysis. PNU282987 treatment facilitated the angiogenic abilities of EPCs compared with the control regimen. The western blot data suggested that PNU282987 increased the levels of p-JAK2 and p-STAT3. However, the differences in t-JAK2 levels and t-STAT3 levels between the agonist-treated group and the control group were not significant. Moreover, treating EPCs with AG490 reduced STAT3 phosphorylation and attenuated the PNU282987-induced enhancement of EPCs. We demonstrated that activating α7nAChRs can enhance EPC functions partially through the JAK2/STAT3 signaling pathway. This study reveals that α7nAChRs are potential therapeutic targets for angiogenesis and that the JAK2/STAT3 pathway plays a vital role in the associated therapeutic mechanism.


Assuntos
Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Células Progenitoras Endoteliais/efeitos dos fármacos , Janus Quinase 2/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Agonistas Nicotínicos/farmacologia , Fator de Transcrição STAT3/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Animais , Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Progenitoras Endoteliais/metabolismo , Masculino , Fosforilação , Ratos Sprague-Dawley , Transdução de Sinais , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
7.
Life Sci ; 244: 117332, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31962133

RESUMO

AIMS: It has been demonstrated that reduced expression of alpha7 nicotinic acetylcholine receptor (α7nAChR) led to reduced chemotherapeutic drugs resistance in various cancer cells. However, whether small interfering RNA (siRNA) mediated knockdown of α7nAChR can reduce sorafenib (SOR) resistance in HCC cells remains to be determined. MATERIALS AND METHODS: The effects of α7nAChR-siRNA in combination with SOR treatment was analyzed in human (HepG2) and mouse (Hepa 1-6) HCC cell lines. The MTT, DAPI staining and flow cytometry assays were applied to measure the cell viability, apoptosis and cell cycle progression of the cells. Also, the changes in the mRNA and protein levels of the α7nAChR were measured by quantitative real-time PCR and western blot analysis, respectively. KEY FINDINGS: The results revealed that SOR increased both mRNA and protein levels of α7nAChR in HCC cells. Treatment with α7nAChR-siRNA abolished these effects. Also, SOR treatment in combination with α7nAChR-siRNA significantly sensitizes HCC cells to SOR cytotoxicity. This combination therapy significantly induced HCC cells apoptosis compared to SOR alone. SIGNIFICANCE: These experimental results indicate that knockdown of α7nAChR by siRNA increased the SOR antitumor activity of HCC cells and suggests that this additive combination is a promising drug candidate for HCC therapy.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe/farmacologia , Receptor Nicotínico de Acetilcolina alfa7/genética , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Camundongos , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
8.
Life Sci ; 243: 117301, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31953160

RESUMO

AIM: Pancreatic stellate cells (PSCs) are the main functional cells leading to pancreatic fibrosis. Nicotine is widely considered as an independent risk factor of pancreatic fibrosis, but the mechanism is still unclear. Our study was aimed to explore the effects of nicotine on human pancreatic stellate cells (hPSCs) and involved pathways. MATERIALS AND METHODS: Primary human PSCs were cultured and treated with nicotine (0.1 µM and 1 µM). The proliferation, apoptosis, α-SMA expression, extracellular matrix metabolism and autophagy of hPSCs were detected by CCK-8 assay, flow cytometry, real-time PCR and Western blotting analysis. The α7nAChR-mediated JAK2/STAT3 signaling pathway was also examined, and an α7nAChR antagonist α-bungarotoxin (α-BTX) was used to perform inhibition experiments. KEY FINDINGS: The proliferation, α-SMA expression and autophagy of hPSCs were significantly promoted by 1 µM nicotine. Meanwhile, the apoptosis of hPSCs was significantly reduced. The extracellular matrix metabolism of hPSCs was also regulated by nicotine. Moreover, the α7nAChR-mediated JAK2/STAT3 signaling pathway was activated by nicotine, this pathway and effects of nicotine can be blocked by α-BTX. SIGNIFICANCE: Our finding suggests that nicotine can promote activation of human pancreatic stellate cells (hPSCs) through inducing autophagy via α7nAChR-mediated JAK2/STAT3 signaling pathway, providing a new insight into the mechanisms by which nicotine affects pancreatic fibrosis.


Assuntos
Autofagia/efeitos dos fármacos , Janus Quinase 2/metabolismo , Nicotina/farmacologia , Células Estreladas do Pâncreas/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Actinas/metabolismo , Células Cultivadas , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/metabolismo , Humanos , Células Estreladas do Pâncreas/metabolismo
9.
J Surg Res ; 246: 6-18, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31541709

RESUMO

BACKGROUND: Remote ischemic postconditioning (RIPost) has been shown to reduce the ischemia-reperfusion injury of the heart and brain. However, the protection mechanisms have not yet been fully elucidated. We have observed that RIPost could alleviate the brain injury after cardiac arrest (CA). The aim of this study was to explore whether α7 nicotinic acetylcholine receptor (α7nAChR) mediates the neuroprotection of RIPost in a rat model of asphyxial CA. MATERIALS AND METHODS: Asphyxial CA model was induced by occlusion of the tracheal tube for 8 min and resuscitated later. RIPost produced by three cycles of 15-min occlusion and 15-min release of the right hind limb by a tourniquet was performed respectively at the moment and the third hour after restoration of spontaneous circulation. The α7nAChR agonist PHA-543613 and the antagonist methyllycaconitine (MLA) were used to investigate the role of α7nAChR in mediating neuroprotective effects. RESULTS: Results showed that α7nAChR was decreased in hippocampus and cortex after resuscitation, whereas RIPost could attenuate the reduction. The use of PHA-543613 provided neuroprotective effects against cerebral injury after CA. Furthermore, RIPost decreased the levels of neuron-specific enolase, inflammatory mediators, the number of apoptotic cells, and phosphorylation of nuclear factor-κB while increased the phosphorylation of signal transducer and activator of transcription-3. However, the above effects of RIPost were attenuated by α7nAChR antagonist methyllycaconitine. CONCLUSIONS: Neuroprotection of RIPost was related with the activation of α7nAChR, which could suppress nuclear factor-κB and activate signal transducer and activator of transcription-3 in a rat asphyxial CA model.


Assuntos
Parada Cardíaca/terapia , Hipóxia Encefálica/terapia , Pós-Condicionamento Isquêmico , Neuroproteção/fisiologia , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Aconitina/análogos & derivados , Aconitina/farmacologia , Animais , Asfixia/complicações , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Modelos Animais de Doenças , Parada Cardíaca/etiologia , Hipocampo/irrigação sanguínea , Hipocampo/patologia , Humanos , Hipóxia Encefálica/etiologia , Hipóxia Encefálica/patologia , Masculino , NF-kappa B/metabolismo , Neuroproteção/efeitos dos fármacos , Quinuclidinas/farmacologia , Ratos , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Resultado do Tratamento , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Receptor Nicotínico de Acetilcolina alfa7/antagonistas & inibidores
10.
J Thorac Cardiovasc Surg ; 159(3): 813-824.e1, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31030961

RESUMO

OBJECTIVES: Delayed paraplegia developed postoperatively after thoracoabdominal aneurysm surgery is primarily associated with spinal cord ischemia/reperfusion injury. Our previous study suggested that spinal cord stimulation postconditioning protected the spinal cord from ischemia/reperfusion injury through microglia inhibition. In this study, we further investigated whether α7 nicotinic acetylcholine receptors were involved in the neuroprotective mechanism of spinal cord stimulation. METHODS: Rabbits were randomly assigned to sham, control, 2 Hz, α-bungarotoxin, and 2 Hz-α-bungarotoxin groups (n = 24/group). Transient spinal cord ischemia was performed on all rabbits except rabbits in the sham group. Rabbits in the control group received no further intervention, rabbits in the 2 Hz group were given 2 Hz spinal cord stimulation, rabbits in the α-bungarotoxin group received prescribed intrathecal α-bungarotoxin (α-bungarotoxin, a specific α7 nicotinic acetylcholine receptor antagonist) injections, and rabbits in the 2 Hz-α-bungarotoxin group received both α-bungarotoxin injections and 2 Hz spinal cord stimulation. Hind-limb neurologic function was assessed, and spinal cord histologic examination, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, and microglia staining were performed at 8 hours, 1 day, 3 days, and 7 days of reperfusion. RESULTS: Rabbits in the 2 Hz group had significantly better neurologic functions, more α-motor neurons, and lower terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive neuron rates and microglia area/anterior horn area ratios (microglia area ratios) than the control group. The neurologic functions of the α-bungarotoxin group were significantly worse than those of the control group, whereas other results were not significantly different from the control group. The results of the 2 Hz-α-bungarotoxin group were insignificant to the control group except for the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive neuron rates, which were significantly lower than in the control group. CONCLUSIONS: The neuroprotective effects of spinal cord stimulation postconditioning against spinal cord ischemia/reperfusion injury were partially mediated by activating α7 nicotinic acetylcholine receptors.


Assuntos
Microglia/metabolismo , Músculo Esquelético/inervação , Paraplegia/prevenção & controle , Traumatismo por Reperfusão/prevenção & controle , Isquemia do Cordão Espinal/prevenção & controle , Estimulação da Medula Espinal , Medula Espinal/irrigação sanguínea , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Apoptose , Modelos Animais de Doenças , Membro Posterior , Masculino , Microglia/patologia , Paraplegia/metabolismo , Paraplegia/patologia , Paraplegia/fisiopatologia , Coelhos , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Isquemia do Cordão Espinal/metabolismo , Isquemia do Cordão Espinal/patologia , Isquemia do Cordão Espinal/fisiopatologia , Fatores de Tempo
11.
Am J Physiol Regul Integr Comp Physiol ; 318(1): R135-R147, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31596111

RESUMO

Sepsis induces organ dysfunction due to overexpression of the inflammatory host response, resulting in cardiopulmonary and autonomic dysfunction, thus increasing the associated morbidity and mortality. Wharton's jelly-derived mesenchymal stem cells (WJ-MSCs) express genes and secrete factors with anti-inflammatory properties, neurological and immunological protection, as well as improve survival in experimental sepsis. The cholinergic anti-inflammatory pathway (CAP) is mediated by α7-nicotinic acetylcholine receptors (α7nAChRs), which play an important role in the control of systemic inflammation. We hypothesized that WJ-MSCs attenuate sepsis-induced organ injury in the presence of an activated CAP pathway. To confirm our hypothesis, we evaluated the effects of WJ-MSCs as a treatment for cardiopulmonary injury and on neuroimmunomodulation. Male Wistar rats were randomly divided into four groups: control (sham-operated); cecal ligation and puncture (CLP) alone; CLP+WJ-MSCs (1 × 106 cells, at 6 h post-CLP); and CLP+methyllycaconitine (MLA)+WJ-MSCs (5 mg/kg body wt, at 5.5 h post-CLP, and 1 × 106 cells, at 6 h post-CLP, respectively). All experiments, including the assessment of echocardiographic parameters and heart rate variability, were performed 24 h after CLP. WJ-MSC treatment attenuated diastolic dysfunction and restored baroreflex sensitivity. WJ-MSCs also increased cardiac sympathetic and cardiovagal activity. WJ-MSCs reduced leukocyte infiltration and proinflammatory cytokines, effects that were abolished by administration of a selective α7nAChR antagonist (MLA). In addition, WJ-MSC treatment also diminished apoptosis in the lungs and spleen. In cardiac and splenic tissue, WJ-MSCs downregulated α7nAChR expression, as well as reduced the phospho-STAT3-to-total STAT3 ratio in the spleen. WJ-MSCs appear to protect against sepsis-induced organ injury by reducing systemic inflammation, at least in part, via a mechanism that is dependent on an activated CAP.


Assuntos
Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/fisiologia , Neuroimunomodulação , Sepse/terapia , Geleia de Wharton/citologia , Animais , Citocinas , Humanos , Masculino , Miocárdio/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Baço/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
12.
Toxicol Lett ; 318: 12-21, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31622651

RESUMO

Maternal smoking during pregnancy and lactation is associated with increased fat mass in the offspring, but the mechanism by which this occurs is not fully understood. Our study focused on the relationships among maternal nicotine exposure, adipose angiogenesis and adipose tissue function in female offspring. Pregnant rats were randomly assigned to nicotine or control groups. Microvascular density, lipid metabolism and α7nAChR-Egr1-FGF2 signaling pathway genes/proteins were tested in 4-, 12- and 26-week female offspring. In vitro, nicotine concentration- and time-response experiments were conducted in 3T3-L1. Lipid metabolism and α7nAChR-Egr1-FGF2 signaling pathway genes/proteins were tested. The conditioned media of differentiated 3T3-L1 treated with nicotine were used to observe tube formation in human umbilical vein endothelial cells (HUVECs). Nicotine-exposed females presented higher adipose microvascular density. The gene expression of α7nAChR, Egr1 and FGF2 was significantly increased in gonadal white adipose tissue (gWAT) and inguinal subcutaneous WAT (igSWAT) of nicotine-exposed females at 4 weeks of age. The protein expression of α7nAChR, Egr1 and FGF2 was increased in gWAT and igSWAT of nicotine-exposed females at 4 weeks of age, and increased in gWAT at 26 weeks. In vitro, nicotine increased the expression of lipid metabolism and α7nAChR-Egr1-FGF2 signaling pathway genes/proteins in a concentration- and time-dependent manner. In the tube formation experiment, adipocytes affected by nicotine promoted HUVEC angiogenesis. Therefore, maternal nicotine exposure promoted the early angiogenesis of adipose tissue via the α7nAChR-Egr1-FGF2 signaling pathway, and this angiogenesis mechanism was associated with increased adipogenesis in adipose tissue of female offspring.


Assuntos
Adipócitos/efeitos dos fármacos , Tecido Adiposo Branco/irrigação sanguínea , Neovascularização Fisiológica/efeitos dos fármacos , Nicotina/toxicidade , Agonistas Nicotínicos/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Células 3T3-L1 , Adipócitos/metabolismo , Animais , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Feminino , Fator 2 de Crescimento de Fibroblastos/genética , Fator 2 de Crescimento de Fibroblastos/metabolismo , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Exposição Materna , Camundongos , Gravidez , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/genética , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
13.
Phytochemistry ; 170: 112187, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31865001

RESUMO

Nicotinic acetylcholine receptor (nAChR) subtype-selective pharmacological profiles of tobacco alkaloids are essential for understanding the physiological effects of tobacco products. In this study, automated electrophysiology was used to functionally characterize the effects of distinct groups of tobacco alkaloids on human α4ß2 and α7 nAChRs. We found that, in tobacco alkaloids, pyridine as a hydrogen bond acceptor and a basic nitrogen atom at a distance of 4-7 Šare pharmacophoric elements necessary for molecular recognition by α4ß2 and α7 nAChRs with various degrees of selectivity, potency, and efficacy. While four alkaloids-nicotine, nornicotine, anabasine and R-anatabine-potently activated α4ß2, they were also weak agonists of α7 nAChRs. Nicotine was the most potent agonist of α4ß2, while anabasine elicited the highest activation of α7. None of the tobacco alkaloids enhanced nAChR activity elicited by the endogenous ligand acetylcholine; therefore, none was considered to be a positive allosteric modulator (PAM) of either α4ß2 or α7 nAChRs. In contrast, we identified tobacco alkaloids, such as the tryptophan metabolite 6-hydroxykynurenic acid, that decreased the activity of both α4ß2 and α7 nAChRs. Our study identified a class of alkaloids with positive and negative effects against human α4ß2 and α7 nAChRs. It also revealed human α4ß2 to be the principal receptor for sensing the most abundant alkaloids in tobacco leaves.


Assuntos
Alcaloides/farmacologia , Produtos Biológicos/farmacologia , Compostos Fitoquímicos/farmacologia , Receptores Nicotínicos/metabolismo , Tabaco/química , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Alcaloides/química , Alcaloides/isolamento & purificação , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Relação Dose-Resposta a Droga , Humanos , Ligantes , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Relação Estrutura-Atividade , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
14.
Behav Pharmacol ; 30(8): 730-737, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31625977

RESUMO

Chronic inflammation plays an important role in the mechanisms underpinning the development of anesthesia-induced cognitive dysfunction. However, less is known about how anesthesia causes inflammation. One possibility is that the inflammation is related to alteration of the activity of the alpha 7 nicotinic acetylcholine receptor cholinergic anti-inflammatory pathway. This study analyzed the effect of sevoflurane administration on the cognitive function by using a novel object recognition test and Y-maze test, and on acetylcholinesterase activity and expression in hippocampal tissue by using an acetylcholinesterase assay kit and quantitative real-time PCR. This study also evaluated the effect of alpha 7 nicotinic acetylcholine receptor agonist PNU-282987 and antagonist methyllycaconitine on cognitive function and the level of hippocampal tumor necrosis factor-α in aged rats exposed to sevoflurane anesthesia. We found that 3% sevoflurane significantly impaired cognitive function and increased acetylcholinesterase activity by upregulating its expression in hippocampal tissue. Sevoflurane-induced impairment of cognitive function was significantly rescued by PNU-282987 but aggravated by methyllycaconitine. In addition to impairment of cognitive function, sevoflurane also significantly increased tumor necrosis factor-α level in plasma and hippocampal tissue. Similarly, this sevoflurane-induced change of tumor necrosis factor-α level in rats was antagonized by PNU-282987 but amplified by methyllycaconitine. In conclusion, our data show that the development of inflammation in sevoflurane-induced cognitive decline is associated with the downregulation of alpha 7 nicotinic acetylcholine receptor cholinergic anti-inflammatory pathway in aged rats.


Assuntos
Inflamação/fisiopatologia , Neuroimunomodulação/efeitos dos fármacos , Sevoflurano/farmacologia , Acetilcolinesterase/metabolismo , Anestésicos Inalatórios/farmacologia , Animais , Benzamidas/metabolismo , Encéfalo/efeitos dos fármacos , Compostos Bicíclicos com Pontes/metabolismo , Cognição/fisiologia , Disfunção Cognitiva/metabolismo , Hipocampo/efeitos dos fármacos , Inflamação/imunologia , Masculino , Éteres Metílicos/farmacologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
15.
Pharmacol Rep ; 71(6): 1168-1176, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31655281

RESUMO

BACKGROUND: Previous studies have shown that α7 nicotinic acetylcholine receptor (nAChR) has a critical role in the regulation of pain sensitivity and neuroinflammation. However, pharmacological effects of α7 nAChR activation in the hippocampus on neuroinflammatory mechanisms associated with allodynia and hyperalgesia remain unknown. We have determined the effects of 3a,4,5,9b-tetrahydro-4-(1-naphthalenyl)-3H-cyclopentan[c]quinoline-8-sulfonamide (TQS), an α7 nAChR positive allosteric modulator, on lipopolysaccharide (LPS)-induced allodynia and hyperalgesia in mice. We also evaluated the effects of TQS on immunoreactivity of microglial marker ionized-calcium binding adaptor molecule 1 (Iba-1), phospho-nuclear factor-κB (p-NF-κB p65), tumor necrosis factor-alpha (TNF-α), and norepinephrine (NE) level. METHODS: Mice were treated with (0.25, 1 or 4 mg/kg, ip) followed by LPS (1 mg/kg, ip) administration. Allodynia and hyperalgesia were determined using von Frey filaments and hot plate respectively. Immunoreactivity of Iba-1, p-NF-κB p65, and TNF-α, were measured in the hippocampus using immunofluorescence assay. Hippocampal NE level was evaluated using high performance liquid chromatography. RESULTS: LPS administration resulted in allodynia and hyperalgesia in mice after six h. Systemic administration of TQS prevented LPS-induced allodynia and hyperalgesia. TQS pretreatment significantly decreased the immunoreactivity of Iba-1, p-NF-κB, and TNF-α in CA1 and DG regions of the hippocampus. In addition, TQS reversed LPS-induced NE reduction in the hippocampus. CONCLUSIONS: Taken together, our results suggest that TQS prevented LPS-induced allodynia and hyperalgesia, upregulation of TNF-α expression and NE level reduction involving microglial α7 nAChR in part in the hippocampus. Therefore, these findings highlight the important effects of α7 nAChR allosteric modulator against symptoms of inflammatory pain.


Assuntos
Regulação Alostérica/efeitos dos fármacos , Hipocampo/metabolismo , Hiperalgesia/metabolismo , Lipopolissacarídeos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Hipocampo/efeitos dos fármacos , Inflamação/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Microglia/metabolismo , NF-kappa B/metabolismo , Naftalenos/farmacologia , Dor/metabolismo , Quinolinas/farmacologia , Sulfonamidas/farmacologia
16.
BMC Cancer ; 19(1): 976, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640627

RESUMO

BACKGROUND: Nicotinic acetylcholine receptors (nAChRs) have been reported to be overexpressed in malignancies in humans and is associated with tumorigenesis and cell migration. In previous studies of gastric cancer, alpha7 nicotinic acetylcholine receptor (α7-nAChR) overexpression leads to epithelial-mesenchymal transition (EMT) and promotes the migration of gastric cancer cells. Recombinant avirulent LaSota strain of Newcastle disease virus (NDV) expressing the rabies virus glycoprotein (rL-RVG) may promote apoptosis of gastric cancer cells and reduces the migration of lung cancer metastasis. However, whether rL-RVG inhibits migration of gastric cancer cells and what the underlying functional mechanism is remains unknown. METHODS: The gastric cancer cell lines BGC and SGC were randomly divided into 3 groups: rL-RVG, NDV and Phosphate Buffered Solution (PBS) control groups. Furthermore,we adopted ACB and MLA,α7nAChR-siRNA for the overexpression and silencing of α7-nAChR.Corynoxenine was used for inhibiting the MEK-ERK pathway. Western blot, Immunofluoresce,cell proliferation assays,cell migration analyses through wound-healing assays and Transwell assays were used to explore the underlying mechanisms. A mouse xenograft model was used to investigate the effects of rL-RVG,NDV on tumor growth. RESULTS: In this study, our findings demonstrate that rL-RVG suppressed the migration of gastric cancer cells and reduced EMT via α7-nAChR in vitro. Furthermore rL-RVG decreased the phosphorylation levels of the MEK/ERK signaling pathway such as down-regulating the expression of P-MEK and P-ERK. Additionally, rL-RVG also reduced the expression level of mesenchymal markers N-cadherin and Vimentin and enhanced the expression of the epithelial marker E-cadherin. Lastly, rL-RVG inhibited nicotinic acetylcholine receptors (nAChRs) to suppress cell migration and epithelial to mesenchymal transition (EMT) in gastric cell. We also found that rL-RVG suppresses the growth of gastric cancer subcutaneous tumor cells in vivo. CONCLUSION: rL-RVG inhibits α7-nAChR-MEK/ERK-EMT to suppress migration of gastric cancer cells.


Assuntos
Movimento Celular , Transição Epitelial-Mesenquimal , Sistema de Sinalização das MAP Quinases , Vírus da Doença de Newcastle/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Apoptose , Linhagem Celular Tumoral , Descoberta de Drogas/métodos , Inativação Gênica , Glicoproteínas/metabolismo , Xenoenxertos , Humanos , Camundongos , Camundongos Nus , Vírus da Doença de Newcastle/genética , RNA Interferente Pequeno/genética , Vírus da Raiva/química , Neoplasias Gástricas/tratamento farmacológico , Proteínas Virais/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/genética
17.
Cell Physiol Biochem ; 53(4): 701-712, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31592599

RESUMO

BACKGROUND/AIMS: Cholinergic signalling mediated by the activation of muscarinic and nicotinic receptors has been described in the literature as a classic and important signalling pathway in the regulation of the inflammatory response. Recent research has investigated the role of acetylcholine, the physiological agonist of these receptors, in the control of energy homeostasis at the central level. Studies have shown that mice that do not express acetylcholine in brain regions regulating energy homeostasis present with excessive weight gain and hyperphagia. However, it has not yet been well-described in the literature which cholinergic receptor subunits are involved in this response; moreover, the signalling pathways responsible for the observed effects are not fully delineated. The hypothalamus is the regulating centre of energy homeostasis, and the α7 subunit of the nicotinic acetylcholine receptor (α7nAChR) is highly expressed in this region. When active, α7nAChR recruits proteins such as JAK2/STAT3 to mediate its signalling; the same intracellular components are required by leptin, an anorexigenic hormone. The aim of the present study was to evaluate the role of the hypothalamic α7nAChR in the control of energy homeostasis. METHODS: The work was performed on Swiss male mice. Initially, using immunofluorescent staining on brain sections, the presence of α7nAChR in hypothalamic cells regulating energy homeostasis was evaluated. Animals were submitted to stereotaxis in the lateral ventricle and intracerebroventricular stimulation (ICV) was used for the administration of an agonist (PNU) or antagonist (α-bungarotoxin) of α7nAChR. Metabolic parameters were evaluated and the expression of neuropeptides was evaluated in the hypothalamus by real-time PCR and western blot. The expression of hypothalamic neuropeptides was evaluated in mice treated with siRNA or inhibitors of JAK2/STAT3 (AG490 and STATTIC) proteins. We also evaluated food intake in α7nAChR knockout animals (α7KO). Additionally, in mouse hypothalamic cell culture (the mypHoA-POMC/GFP lineage), we evaluated the expression of neuropeptides and pSTAT3 after stimulation with PNU. RESULTS: Our results indicate co-localisation of α7nAChR with α-MSH, AgRP and NPY in hypothalamic cells. Pharmacological activation of α7nAChR reduced food intake and increased hypothalamic POMC expression and decreased NPY and AgRP mRNA levels and the protein content of pAMPK. Inhibition of α7nAChR with an antagonist increased the mRNA content of NPY and AgRP. Inhibition of α7nAChR with siRNA led to the suppression of POMC expression and an increase in AgRP mRNA levels. α7KO mice showed no changes in food intake. Inhibition of proteins involved in the JAK2/STAT3 signalling pathway reversed the effects observed after PNU stimulation. POMC-GFP cells, when treated with PNU, showed increased POMC expression and nuclear translocation of pSTAT3. CONCLUSION: Thus, selective activation of α7nAChR is able to modulate important markers of the response to food intake, suggesting that α7nAChR activation can suppress the expression of orexigenic markers and favour the expression of anorexics using the intracellular JAK2/STAT3 machinery.


Assuntos
Proteína Relacionada com Agouti/metabolismo , Janus Quinase 2/metabolismo , Pró-Opiomelanocortina/metabolismo , Fator de Transcrição STAT3/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Proteína Relacionada com Agouti/genética , Animais , Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Bungarotoxinas/farmacologia , Linhagem Celular , Ingestão de Alimentos/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Janus Quinase 2/antagonistas & inibidores , Janus Quinase 2/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Pró-Opiomelanocortina/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Transdução de Sinais/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Receptor Nicotínico de Acetilcolina alfa7/antagonistas & inibidores , Receptor Nicotínico de Acetilcolina alfa7/genética
18.
PLoS One ; 14(10): e0223180, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31581202

RESUMO

Cognitive impairments are a common consequence of traumatic brain injury (TBI). The hippocampus is a subcortical structure that plays a key role in the formation of declarative memories and is highly vulnerable to TBI. The α7 nicotinic acetylcholine receptor (nAChR) is highly expressed in the hippocampus and reduced expression and function of this receptor are linked with cognitive impairments in Alzheimer's disease and schizophrenia. Positive allosteric modulation of α7 nAChRs with AVL-3288 enhances receptor currents and improves cognitive functioning in naïve animals and healthy human subjects. Therefore, we hypothesized that targeting the α7 nAChR with the positive allosteric modulator AVL-3288 would enhance cognitive functioning in the chronic recovery period of TBI. To test this hypothesis, adult male Sprague Dawley rats received moderate parasagittal fluid-percussion brain injury or sham surgery. At 3 months after recovery, animals were treated with vehicle or AVL-3288 at 30 min prior to cue and contextual fear conditioning and the water maze task. Treatment of TBI animals with AVL-3288 rescued learning and memory deficits in water maze retention and working memory. AVL-3288 treatment also improved cue and contextual fear memory when tested at 24 hr and 1 month after training, when TBI animals were treated acutely just during fear conditioning at 3 months post-TBI. Hippocampal atrophy but not cortical atrophy was reduced with AVL-3288 treatment in the chronic recovery phase of TBI. AVL-3288 application to acute hippocampal slices from animals at 3 months after TBI rescued basal synaptic transmission deficits and long-term potentiation (LTP) in area CA1. Our results demonstrate that AVL-3288 improves hippocampal synaptic plasticity, and learning and memory performance after TBI in the chronic recovery period. Enhancing cholinergic transmission through positive allosteric modulation of the α7 nAChR may be a novel therapeutic to improve cognition after TBI.


Assuntos
Lesões Encefálicas Traumáticas/complicações , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Regulação Alostérica/efeitos dos fármacos , Anilidas/sangue , Anilidas/farmacocinética , Anilidas/farmacologia , Anilidas/uso terapêutico , Animais , Atrofia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Doença Crônica , Transtornos Cognitivos/fisiopatologia , Condicionamento Clássico , Medo , Isoxazóis/sangue , Isoxazóis/farmacocinética , Isoxazóis/farmacologia , Isoxazóis/uso terapêutico , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto , Memória de Curto Prazo , Ratos Sprague-Dawley , Transmissão Sináptica/efeitos dos fármacos
19.
Medicina (Kaunas) ; 55(10)2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31547185

RESUMO

Background and Objectives: The knowledge that the cholinergic neurons from pedunculopontine nucleus (PPN) are vulnerable to the degeneration in early stages of the Parkinson disease progression has opened new perspectives to the development of experimental model focused in pontine lesions that could increase the risk of nigral degeneration. In this context it is known that PPN lesioned rats exhibit early changes in the gene expression of proteins responsible for dopaminergic homeostasis. At the same time, it is known that nicotinic cholinergic receptors (nAChRs) mediate the excitatory influence of pontine-nigral projection. However, the effect of PPN injury on the expression of transcription factors that modulate dopaminergic neurotransmission in the adult brain as well as the α7 nAChRs gene expression has not been studied. The main objective of the present work was the study of the effects of the unilateral neurotoxic lesion of PPN in nuclear receptor-related factor 1 (Nurr1), paired-like homeodomain transcription factor 3 (Pitx3), and α7 nAChRs mRNA expression in nigral tissue. Materials and Methods: The molecular biology studies were performed by means of RT-PCR. The following experimental groups were organized: Non-treated rats, N-methyl-D-aspartate (NMDA)-lesioned rats, and Sham operated rats. Experimental subjects were sacrificed 24 h, 48 h and seven days after PPN lesion. Results: Nurr1 mRNA expression, showed a significant increase both 24 h (p < 0.001) and 48 h (p < 0.01) after PPN injury. Pitx3 mRNA expression evidenced a significant increase 24 h (p < 0.001) followed by a significant decrease 48 h and seven days after PPN lesion (p < 0.01). Finally, the α7 nAChRs nigral mRNA expression remained significantly diminished 24 h, 48 h (p < 0.001), and 7 days (p < 0.01) after PPN neurotoxic injury. Conclusion: Taking together these modifications could represent early warning signals and could be the preamble to nigral neurodegeneration events.


Assuntos
Neurônios Dopaminérgicos/metabolismo , Proteínas de Homeodomínio/metabolismo , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Doença de Parkinson/metabolismo , Núcleo Tegmental Pedunculopontino/metabolismo , RNA Mensageiro/metabolismo , Substância Negra/metabolismo , Fatores de Transcrição/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Modelos Animais de Doenças , Proteínas de Homeodomínio/genética , Masculino , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Doença de Parkinson/patologia , Núcleo Tegmental Pedunculopontino/patologia , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética , Receptor Nicotínico de Acetilcolina alfa7/genética
20.
Int J Mol Sci ; 20(18)2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31533319

RESUMO

Induced by a bacterial infection, an immune/inflammatory challenge is a potent negative regulator of the reproduction process in females. The reduction of the synthesis of pro-inflammatory cytokine is considered as an effective strategy in the treatment of inflammatory induced neuroendocrine disorders. Therefore, the effect of direct administration of acetylcholinesterase inhibitor-neostigmine-into the third ventricle of the brain on the gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) secretions under basal and immune stress conditions was evaluated in this study. In the study, 24 adult, 2-years-old Blackhead ewes during the follicular phase of their estrous cycle were used. Immune stress was induced by the intravenous injection of LPS Escherichia coli in a dose of 400 ng/kg. Animals received an intracerebroventricular injection of neostigmine (1 mg/animal) 0.5 h before LPS/saline treatment. It was shown that central administration of neostigmine might prevent the inflammatory-dependent decrease of GnRH/LH secretion in ewes and it had a stimulatory effect on LH release. This central action of neostigmine is connected with its inhibitory action on local pro-inflammatory cytokines, such as interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)α synthesis in the hypothalamus, which indicates the importance of this mediator in the inhibition of GnRH secretion during acute inflammation.


Assuntos
Inibidores da Colinesterase/administração & dosagem , Endotoxinas/efeitos adversos , Ciclo Estral/efeitos dos fármacos , Ciclo Estral/metabolismo , Hormônio Liberador de Gonadotropina/biossíntese , Hormônio Luteinizante/biossíntese , Neostigmina/administração & dosagem , Fase Folicular/efeitos dos fármacos , Fase Folicular/metabolismo , Hidrocortisona/biossíntese , Hipotálamo/metabolismo , Lipopolissacarídeos/efeitos adversos , Receptor Nicotínico de Acetilcolina alfa7/metabolismo
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