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1.
Int J Mol Sci ; 25(7)2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38612866

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is highly malignant, with a 5-year survival rate of less than 10%. Furthermore, the acquisition of anticancer drug resistance makes PDAC treatment difficult. We established MIA-GEM cells, a PDAC cell line resistant to gemcitabine (GEM), a first-line anticancer drug, using the human PDAC cell line-MIA-PaCa-2. Microtubule-associated serine/threonine kinase-4 (MAST4) expression was increased in MIA-GEM cells compared with the parent cell line. Through inhibitor screening, dysregulated AKT signaling was identified in MIA-GEM cells with overexpression of AKT3. MAST4 knockdown effectively suppressed AKT3 overexpression, and both MAST4 and AKT3 translocation into the nucleus, phosphorylating forkhead box O3a (FOXO3) in MIA-GEM cells. Modulating FOXO3 target gene expression in these cells inhibited apoptosis while promoting stemness and proliferation. Notably, nuclear MAST4 demonstrated higher expression in GEM-resistant PDAC cases compared with that in the GEM-sensitive cases. Elevated MAST4 expression correlated with a poorer prognosis in PDAC. Consequently, nuclear MAST4 emerges as a potential marker for GEM resistance and poor prognosis, representing a novel therapeutic target for PDAC.


Assuntos
Antineoplásicos , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Resistencia a Medicamentos Antineoplásicos/genética , Microtúbulos , Gencitabina , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Proteína Forkhead Box O3/genética , Proteínas Proto-Oncogênicas c-akt , Proteínas Associadas aos Microtúbulos , Proteínas Serina-Treonina Quinases
2.
Int J Mol Sci ; 25(5)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38474261

RESUMO

Patients with cancer die from cardiac dysfunction second only to the disease itself. Cardiotoxicity caused by anticancer drugs has been emphasized as a possible cause; however, the details remain unclear. To investigate this mechanism, we treated rat cardiomyoblast H9c2 cells with sunitinib, lapatinib, 5-fluorouracil, and cisplatin to examine their effects. All anticancer drugs increased ROS, lipid peroxide, and iron (II) levels in the mitochondria and decreased glutathione peroxidase-4 levels and the GSH/GSSG ratio. Against this background, mitochondrial iron (II) accumulates through the unregulated expression of haem oxygenase-1 and ferrochelatase. Anticancer-drug-induced cell death was suppressed by N-acetylcysteine, deferoxamine, and ferrostatin, indicating ferroptosis. Anticancer drug treatment impairs mitochondrial DNA and inhibits oxidative phosphorylation in H9c2 cells. Similar results were observed in the hearts of cancer-free rats treated with anticancer drugs in vitro. In contrast, treatment with pterostilbene inhibited the induction of ferroptosis and rescued the energy restriction induced by anticancer drugs both in vitro and in vivo. These findings suggest that induction of ferroptosis and inhibition of oxidative phosphorylation are mechanisms by which anticancer drugs cause myocardial damage. As pterostilbene ameliorates these mechanisms, it is expected to have significant clinical applications.


Assuntos
Antineoplásicos , Ferroptose , Humanos , Ratos , Animais , Fosforilação Oxidativa , Antineoplásicos/farmacologia , Morte Celular , Ferro/metabolismo
3.
Int J Mol Sci ; 25(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38473857

RESUMO

Anticancer agents are playing an increasing role in the treatment of gastric cancer (GC); however, novel anticancer agents have not been fully developed. Therefore, it is important to investigate compounds that improve sensitivity to the existing anticancer drugs. We have reported that pterostilbene (PTE), a plant stilbene, enhances the antitumor effect of low doses of sunitinib in gastric cancer cells accumulating mitochondrial iron (II) (mtFe) at low doses. In this study, we investigated the relationship between the mtFe deposition and the synergistic effect of PTE and different anticancer drugs. For this study, we used 5-fluorouracil (5FU), cisplatin (CPPD), and lapatinib (LAP), which are frequently used in the treatment of GC, and doxorubicin (DOX), which is known to deposit mtFe. A combination of low-dose PTE and these drugs suppressed the expression of PDZ domain-containing 8 (PDZD8) and increased mtFe accumulation and mitochondrial H2O2. Consequently, reactive oxygen species-associated hypoxia inducible factor-1α activation induced endoplasmic reticulum stress and led to apoptosis, but not ferroptosis. In contrast, 5FU and CDDP did not show the same changes as those observed with PTE and DOX or LAP, and there was no synergistic effect with PTE. These results indicate that the combination of PTE with iron-accumulating anticancer drugs exhibits a strong synergistic effect. These findings would help in developing novel therapeutic strategies for GC. However, further clinical investigations are required.


Assuntos
Antineoplásicos , Estilbenos , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Peróxido de Hidrogênio/metabolismo , Antineoplásicos/farmacologia , Fluoruracila/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Apoptose , Mitocôndrias/metabolismo , Estilbenos/farmacologia , Estresse do Retículo Endoplasmático , Linhagem Celular Tumoral , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
5.
Int J Mol Sci ; 24(22)2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38003554

RESUMO

N-methyl-glycine (sarcosine) is known to promote metastatic potential in some cancers; however, its effects on bladder cancer are unclear. T24 cells derived from invasive cancer highly expressed GNMT, and S-adenosyl methionine (SAM) treatment increased sarcosine production, promoting proliferation, invasion, anti-apoptotic survival, sphere formation, and drug resistance. In contrast, RT4 cells derived from non-invasive cancers expressed low GNMT, and SAM treatment did not produce sarcosine and did not promote malignant phenotypes. In T24 cells, the expression of miR-873-5p, which suppresses GNMT expression, was suppressed, and the expression of ERVK13-1, which sponges miR-873-5p, was increased. The growth of subcutaneous tumors, lung metastasis, and intratumoral GNMT expression in SAM-treated nude mice was suppressed in T24 cells with ERVK13-1 knockdown but promoted in RT4 cells treated with miR-873-5p inhibitor. An increase in mouse urinary sarcosine levels was observed to correlate with tumor weight. Immunostaining of 86 human bladder cancer cases showed that GNMT expression was higher in cases with muscle invasion and metastasis. Additionally, urinary sarcosine concentrations increased in cases of muscle invasion. Notably, urinary sarcosine concentration may serve as a marker for muscle invasion in bladder cancer; however, further investigation is necessitated.


Assuntos
MicroRNAs , Neoplasias da Bexiga Urinária , Humanos , Animais , Camundongos , Sarcosina/farmacologia , Camundongos Nus , S-Adenosilmetionina/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Neoplasias da Bexiga Urinária/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Movimento Celular
6.
Int J Mol Sci ; 24(8)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37108667

RESUMO

Although gemcitabine (GEM) is widely used in chemotherapy for pancreatic ductal adenocarcinoma (PDA), drug resistance restricts its clinical effectiveness. To examine the mechanism of GEM resistance, we established two GEM-resistant cell lines from human PDA cells by continuous treatment with GEM and CoCl2-induced chemical hypoxia. One resistant cell line possessed reduced energy production and decreased mitochondrial reactive oxygen species levels, while the other resistant cell line possessed increased stemness. In both cell lines, ethidium bromide-stained mitochondrial DNA levels decreased, suggesting mitochondrial DNA damage. Inhibition of hypoxia-inducible factor-1α in both cell lines did not restore the GEM sensitivity. In contrast, treatment of both cell types with lauric acid (LAA), a medium-chain fatty acid, restored GEM sensitivity. These results suggest that decreased energy production, decreased mitochondrial reactive oxygen species levels, and increased stemness associated with mitochondrial damage caused by GEM lead to GEM resistance, and that hypoxia may promote this process. Furthermore, forced activation of oxidative phosphorylation by LAA could be a tool to overcome GEM resistance. Clinical verification of the effectiveness of LAA in GEM resistance is necessary in the future.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Gencitabina , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Espécies Reativas de Oxigênio , Linhagem Celular Tumoral , Carcinoma Ductal Pancreático/patologia , Neoplasias Pancreáticas/metabolismo , DNA Mitocondrial/uso terapêutico , Apoptose , Neoplasias Pancreáticas
7.
Int J Mol Sci ; 24(7)2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-37047157

RESUMO

5-aminolevulinic acid (ALA) is used for tumor-targeting phototherapy because it is converted to protoporphyrin IX (PPIX) upon excitation and induces phototoxicity. However, the effect of ALA on malignant cells under unexcited conditions is unclear. This information is essential when administering ALA systemically. We used sarcoma cell lines that usually arise deep in the body and are rarely exposed to light to examine the effects of ALA treatment under light (daylight lamp irradiation) and dark (dark room) conditions. ALA-treated human SW872 liposarcoma cells and human MG63 osteosarcoma cells cultured under light exhibited growth suppression and increased oxidative stress, while cells cultured in the dark showed no change. However, sphere-forming ability increased in the dark, and the expression of stem-cell-related genes was induced in dark, but not light, conditions. ALA administration increased heme oxygenase 1 (HO-1) expression in both cell types; when carbon monoxide (CO), a metabolite of HO-1, was administered to sarcoma cells via carbon-monoxide-releasing molecule 2 (CORM2), it enhanced sphere-forming ability. We also compared the concentration of biliverdin (BVD) (a co-product of HO-1 activity alongside CO) with sphere-forming ability when HO-1 activity was inhibited using ZnPPIX in the dark. Both cell types showed a peak in sphere-forming ability at 60-80 µM BVD. Furthermore, a cell death inhibitor assay revealed that the HO-1-induced suppression of sphere formation was rescued by apoptosis or ferroptosis inhibitors. These findings suggest that in the absence of excitation, ALA promotes HO-1 expression and enhances the stemness of sarcoma cells, although excessive HO-1 upregulation induces apoptosis and ferroptosis. Our data indicate that systemic ALA administration induces both enhanced stemness and cell death in malignant cells located in dark environments deep in the body and highlight the need to pay attention to drug delivery and ALA concentrations during phototherapy.


Assuntos
Ácido Aminolevulínico , Sarcoma , Humanos , Linhagem Celular , Ácido Aminolevulínico/farmacologia , Ácido Aminolevulínico/uso terapêutico , Apoptose , Morte Celular , Sarcoma/tratamento farmacológico , Heme Oxigenase-1/metabolismo , Protoporfirinas/farmacologia
8.
Int J Mol Sci ; 24(7)2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37047563

RESUMO

Berberine (BBR) is a plant alkaloid that has various biological activities. The effects of BBR on gastrointestinal cancer (GIC) have also been investigated and anti-tumor effects such as induction of cell death have been reported. However, the mechanism of BBR-induced cell death has not been fully elucidated. To this end, we investigated the effects of BBR using three GIC cell lines. Our analyses revealed that BBR inhibited cell proliferation, invasion, sphere formation, and anticancer drug resistance in all of the cell lines. BBR also induced an increase in mitochondrial superoxide, lipid peroxide and Fe2+ levels, decreased mitochondrial membrane potential and respiration, decreased glutathione peroxidase 4 expression and glutathione and induced Parkin/PINK1-associated mitophagy. BBR, as well as rotenone, inhibited mitochondrial complex I and enhanced complex II, which were associated with autophagy, reactive oxidative species production, and cell death. Inhibition of complex II by malonate abrogated these changes. BBR-induced cell death was partially rescued by ferrostatin-1, deferoxamine, Z-VAD-FMK, and ATG5 knockdown. Furthermore, oral administration of BBR significantly reduced tumor weight and ascites in a syngeneic mouse peritoneal metastasis model using CT26 GIC cells. These findings suggest that BBR induced a combined type of cell death via complex I inhibition and autophagy. The marked anti-tumor and anti-stemness effects are expected to be useful as a new cell death-inducing agent for the treatment of GIC.


Assuntos
Berberina , Camundongos , Animais , Berberina/farmacologia , Berberina/uso terapêutico , Morte Celular , Linhagem Celular , Autofagia , Mitofagia , Apoptose
9.
Int J Mol Sci ; 24(6)2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36982569

RESUMO

Claudin-4 (CLDN4) is a key component of tight junctions (TJs) in epithelial cells. CLDN4 is overexpressed in many epithelial malignancies and correlates with cancer progression. Changes in CLDN4 expression have been associated with epigenetic factors (such as hypomethylation of promoter DNA), inflammation associated with infection and cytokines, and growth factor signaling. CLDN4 helps to maintain the tumor microenvironment by forming TJs and acts as a barrier to the entry of anticancer drugs into tumors. Decreased expression of CLDN4 is a potential marker of epithelial-mesenchymal transition (EMT), and decreased epithelial differentiation due to reduced CLDN4 activity is involved in EMT induction. Non-TJ CLDN4 also activates integrin beta 1 and YAP to promote proliferation, EMT, and stemness. These roles in cancer have led to investigations of molecular therapies targeting CLDN4 using anti-CLDN4 extracellular domain antibodies, gene knockdown, clostridium perfringens enterotoxin (CPE), and C-terminus domain of CPE (C-CPE), which have demonstrated the experimental efficacy of this approach. CLDN4 is strongly involved in promoting malignant phenotypes in many epithelial cancers and is regarded as a promising molecular therapeutic target.


Assuntos
Antineoplásicos , Neoplasias , Claudina-4/genética , Claudina-4/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antineoplásicos/metabolismo , Junções Íntimas/metabolismo , Células Epiteliais/metabolismo , Transdução de Sinais , Claudina-3/genética , Enterotoxinas/farmacologia , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo
10.
Cancer Sci ; 113(8): 2904-2915, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35570394

RESUMO

High mobility group box-1 (HMGB1) is known to be a chemotactic factor for mesenchymal stem/stromal cells (MSCs), but the effect of post-translational modification on its function is not clear. In this study, we hypothesized that differences in the oxidation state of HMGB1 would lead to differences in the function of MSCs in cancer. In human colorectal cancer, MSCs infiltrating into the stroma were correlated with liver metastasis and serum HMGB1. In animal models, oxidized HMGB1 mobilized three-fold fewer MSCs to subcutaneous tumors compared with reduced HMGB1. Reduced HMGB1 inhibited the proliferation of mouse bone marrow MSCs (BM-MSCs) and induced differentiation into osteoblasts and vascular pericytes, whereas oxidized HMGB1 promoted proliferation and increased stemness, and no differentiation was observed. When BM-MSCs pretreated with oxidized HMGB1 were co-cultured with syngeneic cancer cells, cell proliferation and stemness of cancer cells were increased, and tumorigenesis and drug resistance were promoted. In contrast, co-culture with reduced HMGB1-pretreated BM-MSCs did not enhance stemness. In an animal orthotopic transplantation colorectal cancer model, oxidized HMGB1, but not reduced HMGB1, promoted liver metastasis with intratumoral MSC chemotaxis. Therefore, oxidized HMGB1 reprograms MSCs and promotes cancer malignancy. The oxidized HMGB1-MSC axis may be an important target for cancer therapy.


Assuntos
Neoplasias Colorretais , Proteína HMGB1 , Neoplasias Hepáticas , Células-Tronco Mesenquimais , Animais , Células da Medula Óssea , Diferenciação Celular , Proliferação de Células , Neoplasias Colorretais/patologia , Proteína HMGB1/metabolismo , Humanos , Neoplasias Hepáticas/secundário , Camundongos
11.
Int J Mol Sci ; 23(1)2021 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-35008652

RESUMO

Cancer dormancy is a state characterized by the quiescence of disseminated cancer cells, and tumor recurrence occurs when such cells re-proliferate after a long incubation period. These cancer cells tend to be treatment resistant and one of the barriers to successful therapeutic intervention. We have previously reported that long-term treatment of cancer cells with linoleic acid (LA) induces a dormancy-like phenotype. However, the mechanism underpinning this effect has not yet been clarified. Here, we investigate the mechanism of LA-induced quiescence in cancer cells. We first confirmed that long-term treatment of the mouse colorectal cancer cell line CT26 with LA induced quiescence. When these cells were inoculated subcutaneously into a syngeneic mouse and fed with an LA diet, the inoculated cancer cells maintained the quiescent state and exhibited markers of dormancy. LA-treated CT26 cells showed reduced oxidative phosphorylation, glycolysis, and energy production as well as reduced expression of the regulatory factors Pgc1α and MycC. MicroRNA expression profiling revealed that LA induced an upregulation in miR-494. The expression of Pgc1α and MycC were both induced by an miR-494 mimic, and the LA-induced decrease in gene expression was abrogated by an miR-494 inhibitor. The expression of miR-494 was enhanced by the mitochondrial oxidative stress produced by LA. In a syngeneic mouse subcutaneous tumor model, growth suppression by an LA diet and growth delay by LA pretreatment + LA diet were found to have similar effects as administration of an miR-494 mimic. In contrast, the effects of LA were abrogated by an miR-494 inhibitor. Analysis of human colorectal cancer tissue revealed that miR-494 was present at low levels in non-metastatic cases and cases with simultaneous liver metastases but was expressed at high levels in cases with delayed liver metastases, which also exhibited reduced expression of PGC1α and MYCC. These results suggest that miR-494 is involved in cancer dormancy induced by high levels of LA intake and that this microRNA may be valuable in targeting dormant cancer cells.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Ácido Linoleico/farmacologia , MicroRNAs/genética , Regulação para Cima/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Glicólise/efeitos dos fármacos , Glicólise/genética , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/genética , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética , Regulação para Cima/genética
12.
Toxicol In Vitro ; 60: 173-179, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31163224

RESUMO

In order to examine effects of general anesthetics on hippocampal synaptic transmission in the absence and presence of amygdala circuitry activation, we have developed a unique amygdala-hippocampal slice preparation in which projections between amygdala and hippocampal CA1 are conserved. Stimulating electrodes were placed in radiatum stratum (Rad) to stimulate CA1, and in amygdala-hippocampal area (AH) to simulate amygdala inputs to hippocampus. Two sets of extracellular recording microelectrodes were positioned in cell bodies and dendrites of CA1 to record population spikes (PSs) and excitatory post-synaptic potentials (EPSPs), respectively. Intravenous anesthetics did not elicit consistent effects on PS and EPSP following a test stimulus on Rad. A pre-pulse of AH in addition to a test-pulse on Rad produced significant reduction of PS amplitude without a change in EPSP. Pre-treatment with tetanus-pulse on AH reversed the anesthetic-induced reduction of PS. The results suggest that inhibitory actions of general anesthetics in CA1 can be modified by activation of amygdala, suggesting that preoperative anxiety and fear could modify anesthetic actions. The modification was more prominent in the presence of intravenous anesthetics than with volatile agents.


Assuntos
Tonsila do Cerebelo/efeitos dos fármacos , Anestésicos Gerais/toxicidade , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Tonsila do Cerebelo/fisiologia , Animais , Hipocampo/fisiologia , Técnicas In Vitro , Masculino , Neurônios/fisiologia , Ratos Wistar
13.
Masui ; 65(3): 275-80, 2016 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-27097508

RESUMO

BACKGROUND: Recent study has shown that postoperative acute kidney injury (AKI) increases postoperative mortality and complications, but correlation between perioperative factors in cardiac surgery and AKI still remains to be explored. The present retrospective study was performed to evaluate the predictors of postoperative AKI in patients undergoing off-pump coronary artery bypass surgery (OPCAB). METHODS: We studied 233 patients undergoing OPCAB at Toyama University Hospital between January 2009 and March 2013. Logistic regression analyses were used to determine whether perioperative factors were associated with postoperative AKI. RESULTS: Postoperative AKI occurred in 39% of the patients. There were statistically significant associations between postoperative AKI and perioperative factors including BMI (multivariable odds ratio, 1.83; 95% Ci, 1.14 to 3.88), hypertension (multivariable odds ratio, 1.80; 95% CI, 1.01 to 3.23), intraoperative urine output (multivariable odds ratio, 1.85; 95% CI, 1.02 to 3.39) and postoperative anemia (multivariable odds ratio, 2.24; 95% CI, 1.24 to 4.12). CONCLUSIONS: In this study, we found that preoperative BMI, hypertension, intraoperative urine output and postoperative anemia might be predictors of postoperative AKI in OPCAB surgery patients.


Assuntos
Injúria Renal Aguda/etiologia , Ponte de Artéria Coronária sem Circulação Extracorpórea/efeitos adversos , Complicações Pós-Operatórias , Idoso , Feminino , Humanos , Masculino , Período Pós-Operatório , Estudos Retrospectivos
14.
Cell Mol Neurobiol ; 33(5): 707-14, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23584686

RESUMO

Immunohistochemistry for two nociceptive transducers, the transient receptor potential cation channel subfamily V members 1 (TRPV1) and 2 (TRPV2), was performed on the pharynx and its adjacent regions. TRPV1-immunoreactivity (IR) was detected in nerve fibers beneath and within the epithelium and/or taste bud-like structure. In the pharynx, these nerve fibers were abundant in the naso-oral part and at the border region of naso-oral and laryngeal parts. They were also numerous on the laryngeal side of the epiglottis and in the soft palate. TRPV2-IR was expressed by dendritic cells in the pharynx and epiglottis, as well as in the root of the tongue and soft palate. These cells were located in the epithelium and lamina propria. TRPV2-immunoreactive (IR) dendritic cells were numerous in the naso-oral part of the pharynx, epiglottis, and tongue. Abundance of TRPV2-IR dendritic processes usually obscured the presence of TRPV2-IR nerve fibers in these portions. However, some TRPV2-IR nerve fibers could be observed in the epithelium of the soft palate. Retrograde tracing method also revealed that sensory neurons which innervate the pharynx or soft palate were abundant in the jugular-petrosal ganglion complex and relatively rare in the nodose ganglion. In the jugular-petrosal ganglion complex, TRPV1- and TRPV2-IR were expressed by one-third of pharyngeal and soft palate neurons. TRPV2-IR was also detected in 11.5 % pharyngeal and 30.9 % soft palate neurons in the complex. Coexpression of TRPV1 and CGRP was frequent among pharyngeal and soft palate neurons. The present study suggests that TRPV1- and TRPV2-IR jugular-petrosal neurons may be associated with the regulation of the swallowing reflex.


Assuntos
Faringe/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Epitélio/metabolismo , Masculino , Mucosa/citologia , Mucosa/metabolismo , Palato Mole/citologia , Palato Mole/inervação , Palato Mole/metabolismo , Faringe/citologia , Faringe/inervação , Ratos , Ratos Wistar , Células Receptoras Sensoriais/citologia , Células Receptoras Sensoriais/metabolismo
15.
Toxicol In Vitro ; 26(6): 872-7, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22579809

RESUMO

Mechanisms by which age modifies general anesthetic requirements remain uncertain. In order to examine the age-related modification of general anesthetics in the central nervous system, we have studied the effects of thiopental and sevoflurane on hippocampal synaptic transmission in young and elderly rats. Field potentials of area CA1 were electrically elicited in hippocampal slices from young (4-month) and elderly (2-year) male Wistat rats. The effects of sevoflurane on both excitatory and inhibitory synaptic transmission were similar in the young and elderly preparations. In contrast, thiopental produced a greater effect on inhibitory synaptic transmission in young than elderly hippocampi, whereas the actions on excitatory synaptic transmission were negligible in both preparations. Corresponding experiments revealed (a) that the duration of recurrent inhibition was more prolonged by thiopental in young compared to elderly animals and (b) that thiopental enhanced the γ-amino-butyric acid (GABA) release from pre-synaptic terminals in an age-dependent manner. The thiopental actions on GABA discharge from pre-synaptic terminals appear to be responsible for the observed difference between young and elderly animals. The age-dependent reduction in neurotransmitter stores in pre-synaptic terminals may explain the age-related alterations in general anesthetic actions.


Assuntos
Anestésicos Gerais/farmacologia , Hipocampo/efeitos dos fármacos , Éteres Metílicos/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Tiopental/farmacologia , Fatores Etários , Animais , Hipocampo/fisiologia , Técnicas In Vitro , Masculino , Ratos , Ratos Wistar , Sevoflurano , Ácido gama-Aminobutírico/fisiologia
16.
Ann Anat ; 194(4): 321-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22197496

RESUMO

Peptide 19 (PEP 19) is a 7.6 kDa polypeptide which can bind to calmodulin and inhibit calcium-calmodulin signaling. In this study, PEP 19-immunoreactivity (ir) was examined in the rat trigeminal sensory nuclei. Numerous PEP 19-immunoreactive (ir) neurons were detected in the medullary dorsal horn (MDH) and rostral parts of the trigeminal sensory nuclei (subnuclei interpolaris and oralis, and nucleus principalis). The mean numbers ± S.D. per section of PEP 19-ir neurons were 104.2 ± 30.4 in the MDH, 137.8 ± 39.5 in the subnucleus interpolaris, 129.2 ± 46.9 in the subnucleus oralis and 157.2 ± 34.1 in the nucleus principalis. In the MDH, small to medium-sized PEP 19-ir neurons were abundant within superficial laminae. PEP 19-ir neurons with various cell body sizes were also distributed in the rostral parts of the trigeminal sensory nuclei. A double immunofluorescence analysis also demonstrated that many PEP 19-ir neurons co-expressed parvalbumin (PV)-ir in the MDH (9.0%), subnucleus oralis (7.7%) and nucleus principalis (19.7%). In the subnucleus interpolaris, such neurons were relatively rare (1.7%). PEP 19-ir neurons were mostly devoid of calbindin D-28k. In addition, a retrograde tracing method revealed that a substantial number of PEP 19-ir neurons projected to the thalamus. PV-ir was common in thalamus-projecting PEP 19-ir neurons. These findings suggest that PEP 19-ir neurons in the MDH may have a function in modulation of nociceptive and thermo-receptive signaling. It is also likely that PEP 19-ir neurons in rostral parts of the trigeminal sensory nuclei are related to transduction of mechano-receptive information from facial regions to the thalamus.


Assuntos
Peptídeos/metabolismo , Células do Corno Posterior/metabolismo , Núcleos do Trigêmeo/metabolismo , Animais , Masculino , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
17.
Masui ; 60(5): 574-81, 2011 May.
Artigo em Japonês | MEDLINE | ID: mdl-21626861

RESUMO

Although general anesthetics were first used more than 160 years ago, their mechanisms have remained mysterious. During the past decade, significant progress in our understanding of general anesthetic action at the cellular and network system levels has been made. Our recent work demonstrates (a) that intravenous anesthetics, but not volatile agents, enhance the discharge of GABA from presynaptic terminals, (b) that intravenous anesthetics produce frequency-dependent modification (FDM) of anesthesia, and (c) that FDM is responsible for the unsuccessful immobilization or hypnosis during intravenous anesthesia. In addition, we review the development of hypothesis for anesthetic action, non-specific versus specific action, cutoff phenomenon in n-alcohols, and anesthesiological approach to consciousness.


Assuntos
Anestesia Geral , Anestésicos Gerais/farmacologia , Fenômenos Eletrofisiológicos/efeitos dos fármacos , Álcoois/farmacologia , Animais , Canais de Cálcio/fisiologia , Estado de Consciência/efeitos dos fármacos , Estado de Consciência/fisiologia , Coração/efeitos dos fármacos , Humanos , Lipídeos de Membrana , Ligação Proteica , Ratos , Receptores de GABA-A/fisiologia , Solubilidade
18.
Anesth Analg ; 110(6): 1607-13, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20435940

RESUMO

BACKGROUND: In clinical anesthesia, robust surgical stress occasionally causes unintended light anesthesia during operation. To test the hypothesis that neural input condition could modify actions of general anesthetics as a result of presynaptic alteration in the central nervous system, we investigated the mechanisms by which the stimulus frequency modifies synaptic transmission of the rat hippocampus in the presence of general anesthetics. METHODS: Field population spikes (PSs) of CA1 pyramidal neurons were elicited using orthodromic stimulation of Schaffer collateral-commissural fibers (test-pulse). A second stimulating electrode was placed in the region of the alveus hippocampi to activate recurrent inhibition of area CA1 (pre-pulse). The pre-pulses were applied as train stimuli (100-200 Hz) to activate release and then deplete the neurotransmitter (gamma-aminobutyric acid [GABA]) at presynaptic terminals of inhibitory interneurons. RESULTS: After the activation of inhibitory interneurons with pre-pulses, both IV (thiopental and pentobarbital) and volatile (sevoflurane and isoflurane) anesthetics attenuated the PS amplitudes elicited with test-pulses (test-PS). The IV anesthetics, but not the volatile drugs, produced stimulus frequency- and use-dependent recurrent inhibition of test-PSs. Neither a GABA type A agonist nor a GABA uptake inhibitor produced frequency-dependent modification. The pre-pulse train protocol revealed that IV anesthetics, but not volatile drugs, can enhance GABA release from presynaptic terminals. CONCLUSIONS: IV anesthetics, but not volatile drugs, enhance the discharge of a readily releasable pool of GABA vesicles from presynaptic terminals. Depletion of an active pool of GABA after high-frequency stimuli would produce frequency- and use-dependent recurrent inhibition in the presence of IV anesthetics. The stimulus frequency-dependent modification of synaptic transmission might be responsible for the unsuccessful immobilization or hypnosis during general anesthesia after IV anesthetic administration.


Assuntos
Anestésicos Gerais/farmacologia , Região CA1 Hipocampal/efeitos dos fármacos , Receptores Pré-Sinápticos/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Animais , Axônios/fisiologia , Região CA1 Hipocampal/anatomia & histologia , Região CA1 Hipocampal/fisiologia , Sistema Nervoso Central/efeitos dos fármacos , Relação Dose-Resposta a Droga , Estimulação Elétrica , Eletrofisiologia , Agonistas de Receptores de GABA-A , Isoflurano/farmacologia , Masculino , Éteres Metílicos/farmacologia , Neurotransmissores/metabolismo , Inibidores da Captação de Neurotransmissores/farmacologia , Células Piramidais/fisiologia , Ratos , Ratos Wistar , Receptores Pré-Sinápticos/metabolismo , Sevoflurano , Tiopental/farmacologia , Ácido gama-Aminobutírico/metabolismo
20.
Masui ; 57(4): 447-9, 2008 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-18416201

RESUMO

Stiff-person syndrome is a rare disease characterized by muscle rigidity and painful spasms in the axial and limb muscles. The authors reported here a case of an axilally lymphadenectomy in a 46-year-old woman with stiff-person syndrome. With train of four ratio (TOFR) monitoring at the ulnar nerve, general anesthesia was induced and maintained with fentanyl, vecuronium and propofol with target controlled infusion. A TOFR, BIS monitor and invasive arterial pressure monitoring were employed. During the operation, there was no muscle rigidity and spasm. Ten minutes after the operation, she was fully awake and train of four ratio recovered to 95%, and extubated uneventfully. We chose propofol, because of previous reports about prolonged hypotonicity by interaction of baclofen and isoflurane. Preoperative good symptom control, choice of total intravenous anesthesia (TIVA), and application of the electrical nerve stimulator prevented postoperative hypotonia and resulted in safe anesthetic management.


Assuntos
Anestesia Intravenosa , Rigidez Muscular Espasmódica , Axila , Estimulação Elétrica , Feminino , Humanos , Excisão de Linfonodo , Linfonodos/cirurgia , Pessoa de Meia-Idade , Monitorização Intraoperatória , Hipotonia Muscular/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , Propofol
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