Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Lab Invest ; 101(6): 745-759, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33495575

RESUMO

Multiple genome-wide association studies (GWAS) have linked Forkhead Box F1 (FOXF1) to Barrett's esophagus (BE). Understanding whether FOXF1 is involved in initiation of Barrett's metaplasia could allow FOXF1 to be used for risk stratification and for therapy. Two-dimensional cell cultures and three-dimensional organoid cultures and well-annotated human biopsies were used to determine the role of FOXF1 in BE pathogenesis. Multiple established esophageal squamous and BE cell lines were tested in gain- and loss-of-function studies. Initiation of a BE-like metaplastic change was evaluated by measuring characteristic cytokeratins and global gene expression profiling and by culturing organoids. Epithelial-mesenchymal transition (EMT) was evaluated by immunostaining for E-cadherin, vimentin and Snail, and by cell motility assay. Columnar esophageal epithelium of BE patients exhibited higher expression of FOXF1 compared to normal squamous esophageal epithelium of GERD patients (P < 0.001). Acidic bile salts induced nuclear FOXF1 in esophageal squamous cells. FOXF1 overexpression in normal esophageal squamous cells: (a) increased columnar cytokeratins and decreased squamous cytokeratins, (b) converted squamous organoids to glandular organoids, and (c) switched global gene profiles to resemble that of human BE epithelium (P = 2.1685e - 06 for upregulated genes and P = 8.3378e - 09 for downregulated genes). FOXF1 inhibition in BE cell lines led to loss of BE differentiation markers, CK7, and mucin 2. Also, FOXF1 induced EMT and promoted cell motility in normal esophageal squamous epithelial cells. FOXF1-induced genes mapped to pathways such as Cancer, Cellular Assembly and Organization, DNA Replication, Recombination, and Repair. In conclusion, FOXF1 promotes a BE-like columnar phenotype and cell motility in esophageal squamous epithelial cells, which may have a critical role in BE development. FOXF1 should be studied further as a biomarker for BE and as a target for BE treatment.


Assuntos
Esôfago de Barrett/etiologia , Transição Epitelial-Mesenquimal , Fatores de Transcrição Forkhead/metabolismo , Idoso , Esôfago de Barrett/metabolismo , Linhagem Celular Tumoral , Células Epiteliais/metabolismo , Esôfago/citologia , Esôfago/metabolismo , Humanos , Pessoa de Meia-Idade
2.
J Cancer ; 11(7): 1927-1939, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32194804

RESUMO

Background: Ovarian cancer (OC), the most lethal gynecologic malignancy, is highly resistant to current treatment strategies. High-grade serous epithelial ovarian cancer (HGSOC) cells with increased somatic mutations and genomic instability and the resulting heterogeneous mutant phenotypes are highly resistant to therapy. Plant-derived natural products, including Amla (Emblica officinalis) extract (AE), have demonstrated potent anti-neoplastic properties. Recently we demonstrated that AE inhibits cell growth and the expression of angiogenic factors in OVCAR3 and SKOV3 OC cells in vitro as well as in xenografts in vivo. The goal of this study was to determine the anti-proliferative, anti-angiogenic and anti-metastatic effects of AE on carboplatinum- and taxol-resistant HGSOC cells carrying p53, BRCA1/2 mutations. Methods: Anti-proliferative and anti-metastatic effects of AE on recently characterized carboplatinum- and taxol-resistant HGSOC cells (TOV3041G, OV866(2), OV4453 and, OV4485) was determined using the MTT, migration, invasion and spheroid assays in vitro. To understand the mechanism of AE-induced changes in angiogenesis-related hypoxia-inducible factor 1α (HIF-1α) and insulin growth factor receptor 1 (IGF1R), and EMT-associated SNAIL1 and E-cadherin proteins were studied using immunostaining and Western blotting. In vivo effects of AE were determined using mouse xenograft tumor model of OC developed by subcutaneous injection of OV4485 cells that carry mutant p53 and BRCA1, most aggressive and resistant among HGSOC cell lines used in this study. Tumor growth was measured using morphometry. Immunostaining and Western blotting were used to determine changes in Ki67 (proliferation marker), CD31 (angiogenesis marker) as well as changes in HIF-1α, IGF1R, SNAIL1 and E-cadherin proteins. Results: AE significantly attenuated migration and invasiveness properties of all tested HGSOC cell phenotypes (P≤0.001), significantly reduced the expression of HIF-1α, IGF1R, and SNAIL1 and increased the expression of E-cadherin in all tested HGSOC cell lines (P=<0.05). Oral administration of AE for 4 weeks caused a significant regression of mouse xenograft tumor (>60%) that derived from OV4855 cells and decreased the expression of endothelial cell antigen-CD31, HIF-1α, IGF1R and SNAIL1 and increased the expression of E-cadherin in tumor tissues. Conclusions: AE sensitizes platinum- and taxol-resistant heterogenous HGSOC cells carrying mutations in p53, BRCA1/2 genes, and attenuates their malignant characteristics through targeting key signaling mechanisms of angiogenesis and metastasis. AE is a potential adjunct therapeutic agent for treating resistant, mutant, heterogenous OC.

3.
Oncotarget ; 7(21): 31484-500, 2016 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-27129171

RESUMO

Ovarian cancer (OC) is highly resistant to current treatment strategies based on a combination of surgery, chemotherapy and radiation therapy. We have recently demonstrated the anti-neoplastic effect of Amla extract (Emblica officinalis, AE) on OC cells in vitro and in vivo. We hypothesized that AE attenuates growth of OC through microRNA (miR)-regulated mechanism(s). The inhibitory effect of AE on proliferation, migration and invasiveness (P≤0.001) of SKOV3 cells and >90% attenuation of tumor growth in a xenograft mouse model suggested multiple targets. RT-qPCR analysis of microRNAs associated with OC showed a >2,000-fold increase in the expression of miR-375 in AE-treated SKOV3 cells that was blocked by an exogenous miR-375 inhibitor (P≤0.001). AE also decreased the gene and protein expression of IGF1R, a target of miR-375 (P≤0.001), and SNAIL1 (P≤0.002), an EMT-associated transcription factor that represses E-cadherin expression (P≤0.003). AE increased E-cadherin expression (P≤0.001). Treatment of SKOV3 cells with AE resulted in increased miR-375 in exosomes in the medium (P≤0.01). Finally, AE significantly decreased the expression of IGF1R and SNAIL1 proteins during attenuation of SKOV3-derived xenograft tumor. Together, these results show that AE modulates cancer cells and the tumor microenvironment via activation of miR-375 and by targeting IGF1R and SNAIL1 in OC cells.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , MicroRNAs/genética , Neoplasias Ovarianas/genética , Phyllanthus emblica/química , Extratos Vegetais/farmacologia , Receptores de Somatomedina/genética , Antígenos CD , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Exossomos/genética , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Receptor IGF Tipo 1 , Receptores de Somatomedina/metabolismo , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/genética , Regulação para Cima/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
4.
PLoS One ; 8(8): e72748, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24133573

RESUMO

Patients with ovarian cancer (OC) may be treated with surgery, chemotherapy and/or radiation therapy, although none of these strategies are very effective. Several plant-based natural products/dietary supplements, including extracts from Emblicaofficinalis (Amla), have demonstrated potent anti-neoplastic properties. In this study we determined that Amla extract (AE) has anti-proliferative effects on OC cells under both in vitro and in vivo conditions. We also determined the anti-proliferative effects one of the components of AE, quercetin, on OC cells under in vitro conditions. AE did not induce apoptotic cell death, but did significantly increase the expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. Quercetin also increased the expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. AE also significantly reduced the expression of several angiogenic genes, including hypoxia-inducible factor 1α (HIF-1α) in OVCAR3 cells. AE acted synergistically with cisplatin to reduce cell proliferation and increase expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. AE also had anti-proliferative effects and induced the expression of the autophagic proteins beclin1 and LC3B-II in mouse xenograft tumors. Additionally, AE reduced endothelial cell antigen - CD31 positive blood vessels and HIF-1α expression in mouse xenograft tumors. Together, these studies indicate that AE inhibits OC cell growth both in vitro and in vivo possibly via inhibition of angiogenesis and activation of autophagy in OC. Thus AE may prove useful as an alternative or adjunct therapeutic approach in helping to fight OC.


Assuntos
Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Neovascularização Patológica/tratamento farmacológico , Neoplasias Ovarianas/patologia , Phyllanthus emblica/química , Extratos Vegetais/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico , Animais , Antineoplásicos/uso terapêutico , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteína Beclina-1 , Proliferação de Células/efeitos dos fármacos , Cisplatino/farmacologia , Sinergismo Farmacológico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Neovascularização Patológica/genética , Neoplasias Ovarianas/irrigação sanguínea , Neoplasias Ovarianas/genética , Extratos Vegetais/uso terapêutico
5.
Fertil Steril ; 95(1): 291.e15-8, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20579642

RESUMO

OBJECTIVE: To determine the role of the aromatase inhibitor letrozole in the treatment of recurrent ovarian endometrioma cases. DESIGN: Nonrandomized proof of concept study. SETTINGS: Outpatient tertiary-care center. PATIENT(S): Five premenopausal patients with documented ovarian endometriomas and chronic pelvic pain, all of whom were previously treated with surgery and medicine with unsatisfactory results. INTERVENTION(S): Ovarian endometriomas were diagnosed by biopsy after laparoscopic ovarian cystectomy and subsequently treated with hormones. After a 6-month washout of endometriosis hormone therapies, women took letrozole (2.5 mg), one tablet of 0.15 mg of desogestrel, and 0.03 mg of ethinyl estradiol, calcium (1,200 mg), and vitamin D3 (800 IU) daily for 6 months. MAIN OUTCOME MEASURE(S): Size of endometriomas (monitored by ultrasound), assessment of pelvic pain (by visual analog scale), and bone density (DEXA scan). RESULT(S): Disappearance of ovarian endometrioma and reduction in pelvic pain in all cases at the end of 6 months. The size of ovarian endometriomas was reduced after 3 months. Pain scores decreased only after 1 month of treatment and continued decreasing in each treatment month. Overall, no significant change in bone density was detected. CONCLUSION(S): Letrozole given with combined pills achieved complete regression of recurrent endometriotic cysts and pain relief in all cases.


Assuntos
Inibidores da Aromatase/uso terapêutico , Endometriose/tratamento farmacológico , Nitrilas/uso terapêutico , Triazóis/uso terapêutico , Adulto , Feminino , Humanos , Letrozol , Indução de Remissão
6.
J Appl Physiol (1985) ; 109(5): 1318-27, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20829501

RESUMO

Sleep is dependent upon prior brain activities, e.g., after prolonged wakefulness sleep rebound occurs. These effects are mediated, in part, by humoral sleep regulatory substances such as cytokines. However, the property of wakefulness activity that initiates production and release of such substances and thereby provides a signal for indexing prior waking activity is unknown. We propose that extracellular ATP, released during neuro- and gliotransmission and acting via purine type 2 (P2) receptors, is such a signal. ATP induces cytokine release from glia. Cytokines in turn affect sleep. We show here that a P2 receptor agonist, 2'(3')-O-(4-benzoylbenzoyl)adenosine 5'-triphosphate (BzATP), increased non-rapid eye movement sleep (NREMS) and electroencephalographic (EEG) delta power while two different P2 receptor antagonists, acting by different inhibitory mechanisms, reduced spontaneous NREMS in rats. Rat P2X7 receptor protein varied in the somatosensory cortex with time of day, and P2X7 mRNA was altered by interleukin-1 treatment, by sleep deprivation, and with time of day in the hypothalamus and somatosensory cortex. Mice lacking functional P2X7 receptors had attenuated NREMS and EEG delta power responses to sleep deprivation but not to interleukin-1 treatment compared with wild-type mice. Data are consistent with the hypothesis that extracellular ATP, released as a consequence of cell activity and acting via P2 receptors to release cytokines and other sleep regulatory substances, provides a mechanism by which the brain could monitor prior activity and translate it into sleep.


Assuntos
Trifosfato de Adenosina/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Transdução de Sinais , Sono , Córtex Somatossensorial/metabolismo , Animais , Ondas Encefálicas , Ritmo Circadiano , Eletroencefalografia , Eletromiografia , Humanos , Interleucina-1/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Agonistas do Receptor Purinérgico P2/administração & dosagem , Antagonistas do Receptor Purinérgico P2/administração & dosagem , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Purinérgicos P2X7/efeitos dos fármacos , Receptores Purinérgicos P2X7/genética , Proteínas Recombinantes/administração & dosagem , Transdução de Sinais/efeitos dos fármacos , Sono/efeitos dos fármacos , Privação do Sono/metabolismo , Privação do Sono/fisiopatologia , Córtex Somatossensorial/efeitos dos fármacos , Córtex Somatossensorial/fisiopatologia
7.
Brain Res ; 1337: 32-40, 2010 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-20398636

RESUMO

Sensory input to different cortical areas differentially varies across the light-dark cycle and likely is responsible, in part, for activity-dependent changes in time-of-day differences in protein expression such as Fos. In this study we investigate time-of-day differences between dark (just before light onset) and light (just before dark onset) for the number of immunoreactive (IR) neurons that stained for tumor necrosis factor alpha (TNFalpha), interleukin-1 beta (IL1 beta), nerve growth factor (NGF), the neuronal nuclear protein (NeuN) and Fos in the rat somatosensory cortex (Sctx) and visual cortex (Vctx). Additionally, astrocyte IL1 beta-IR in the Sctx and Vctx was determined. TNFalpha and IL1 beta, as well as the immediate early gene protein Fos, were higher at the end of the dark phase (2300 h) compared to values obtained at the end of the light phase (1100 h) in the Sctx and Vctx. IL1 beta-IR in Sctx and Vctx astrocytes was higher at 2300 h than that observed at 1100 h. . In contrast, the number of NGF-IR neurons was higher in the Vctx than in the Sctx but did not differ in time. However, the density of the NGF-IR neurons in layer V was greater at 2300 h in the Sctx than at 1100 h. NeuN-IR was higher at 2300 h in the Sctx but was lower at this time in the Vctx compared to 1100 h. These data demonstrate that expressions of the molecules examined are dependent on activity, the sleep-wake cycle and brain location. These factors interact to modulate time-of-day expression.


Assuntos
Ritmo Circadiano/fisiologia , Córtex Somatossensorial/fisiologia , Córtex Visual/fisiologia , Animais , Astrócitos/metabolismo , Contagem de Células , Escuridão , Imuno-Histoquímica , Interleucina-1beta/metabolismo , Luz , Masculino , Fator de Crescimento Neural/metabolismo , Neurônios/metabolismo , Estimulação Física , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Sprague-Dawley , Córtex Somatossensorial/citologia , Fator de Necrose Tumoral alfa/metabolismo , Vibrissas/fisiologia , Córtex Visual/citologia
8.
Am J Perinatol ; 27(6): 507-12, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20175041

RESUMO

We evaluated the maternal and perinatal complications of cesarean delivery performed in the second stage compared with the first stage of labor in nulliparous women. We performed a hospital-based cohort study in a teaching institution in Kolkata, West Bengal, India. The primary maternal outcomes measured included intraoperative surgical complications, duration of surgery, need for blood transfusion, wound infection, transfer to intensive care unit, and length of hospital stay. The neonatal outcomes included 5-minute Apgar score 3 or less, need for endotracheal intubation, admission to neonatal intensive care unit, fetal injury, septicemia, neonatal seizures, and neonatal death. There were 1702 cesarean deliveries performed in the first stage and 124 cases in the second stage. Cesarean deliveries performed in the second stage were associated with longer operation time and increased need for blood transfusion, rates of wound infection, intraoperative complications, and need for transfer to intensive care unit. Neonatal complications included significantly low Apgar score at 5 minutes, increased neonatal death, admission to neonatal intensive care unit, increased need for intubation, septicemia, neonatal seizures, and fetal injury (all having P < 0.05). Cesarean deliveries performed in the second stage of labor were associated with higher rates of maternal and neonatal complications.


Assuntos
Índice de Apgar , Traumatismos do Nascimento/epidemiologia , Cesárea/efeitos adversos , Complicações do Trabalho de Parto/epidemiologia , Adulto , Feminino , Humanos , Índia , Primeira Fase do Trabalho de Parto , Segunda Fase do Trabalho de Parto , Gravidez , Resultado do Tratamento
9.
Brain Res ; 1226: 89-98, 2008 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-18620339

RESUMO

Hypothalamic and cortical mRNA levels for cytokines such as interleukin-1beta (IL1beta), tumor necrosis factor alpha (TNFalpha), nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) are impacted by systemic treatments of IL1beta and TNFalpha. To investigate the time course of the effects of IL1beta and TNFalpha on hypothalamic and cortical cytokine gene expression, we measured mRNA levels for IL1beta, TNFalpha, interleukin-6 (IL-6), interleukin-10 (IL-10), IL1 receptor 1, BDNF, NGF, and glutamate decarboxylase-67 in vitro using hypothalamic and cortical primary cultures. IL1beta and TNFalpha mRNA levels increased significantly in a dose-dependent fashion after exposure to either IL1beta or TNFalpha. IL1beta increased IL1beta mRNA in both the hypothalamic and cortical cultures after 2-6 h while TNFalpha mRNA increased significantly within 30 min and continued to rise up to 2-6 h. Most of the other mRNAs showed significant changes independent of dose in vitro. In vivo, intracerebroventricular (icv) injection of IL1beta or TNFalpha also significantly increased IL1beta, TNFalpha and IL6 mRNA levels in the hypothalamus and cortex. IL1beta icv, but not TNFalpha, increased NGF mRNA levels in both these areas. Results support the hypothesis that centrally active doses of IL1beta and TNFalpha enhance their own mRNA levels as well as affect mRNA levels for other neuronal growth factors.


Assuntos
Citocinas/genética , Interleucina-1alfa/farmacologia , Neurônios/efeitos dos fármacos , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Análise de Variância , Animais , Células Cultivadas , Córtex Cerebral/citologia , Embrião de Mamíferos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hipotálamo/citologia , Masculino , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
10.
Brain Res ; 1156: 125-32, 2007 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-17531209

RESUMO

Tumor necrosis factor alpha (TNFalpha) is a pleiotropic cytokine with several CNS physiological and pathophysiological actions including sleep, memory, thermal and appetite regulation. Short interfering RNAs (siRNA) targeting TNFalpha were incubated with cortical cell cultures and microinjected into the primary somatosensory cortex (SSctx) of rats. The TNFalpha siRNA treatment specifically reduced TNFalpha mRNA by 45% in vitro without affecting interleukin-6 or gluR1-4 mRNA levels. In vivo the TNFalpha siRNAalpha reduced TNFalpha mRNA, interleukin-6 mRNA and gluR1 mRNA levels compared to treatment with a scrambled control siRNA. After in vivo microinjection, the density of TNFalpha-immunoreactive cells in layer V of the SSctx was also reduced. Electroencephalogram (EEG) delta wave power was decreased on days 2 and 3 on the side of the brain that received the TNFalpha siRNA microinjection relative to the side receiving the control siRNA. These findings support the hypothesis that TNFalpha siRNA attenuates TNFalpha mRNA and TNFalpha protein in the rat cortex and that those reductions reduce cortical EEG delta power. Results also are consistent with the notion that TNFalpha is involved in CNS physiology including sleep regulation.


Assuntos
Encéfalo/fisiologia , Ritmo Delta , RNA Interferente Pequeno/genética , Córtex Somatossensorial/fisiologia , Fator de Necrose Tumoral alfa/genética , Animais , Lateralidade Funcional , Imuno-Histoquímica , Interleucina-6/genética , Microinjeções , RNA Mensageiro/genética , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Necrose Tumoral alfa/administração & dosagem , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
11.
Brain Res ; 1053(1-2): 54-61, 2005 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-16040010

RESUMO

Tumor necrosis factor-alpha (TNFalpha) affects several CNS functions such as regulation of sleep, body temperature, and feeding during pathology. There is also evidence for TNFalpha involvement in physiological sleep regulation, e.g., TNFalpha induces sleep and brain levels of TNFalpha increase during prolonged wakefulness. The immediate cause of enhanced TNFalpha production in brain is unknown. We investigated whether glutamate could signal TNFalpha production because glutamate is a neurotransmitter associated with cell activation and wakefulness. We used primary cultures of fetal rat hypothalamic cells to examine the expression and release of TNFalpha. Immunostaining for neuron specific enolase revealed that the cultures were 50-60% neuronal and 40-50% non-neuronal cells. TNFalpha was detected in both the media and cells under basal conditions. Stimulation of the cells with 1 mM glutamate for 2 h produced an increase in media content of TNFalpha, whereas cell content was elevated at earlier time points. Using trypan blue exclusion and MTT assays, there was no evidence of cell toxicity with this stimulation protocol. Immunocytochemical staining revealed that TNFalpha was expressed by approximately 25% of the neurons and approximately 75% of the glial cell in the culture. Stimulation of the cultures with glutamate did not increase the percentage of cells expressing TNFalpha. We conclude that TNFalpha is constitutively expressed and released by healthy cultures of hypothalamic cells and that activation of the cells with a non-toxic challenge of glutamate increases TNFalpha production. These findings support the hypothesis that TNFalpha can participate in normal physiological regulation of sleep and feeding.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Ácido Glutâmico/farmacologia , Hipotálamo/citologia , Neurônios/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo , Análise de Variância , Animais , Contagem de Células/métodos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Ensaio de Imunoadsorção Enzimática/métodos , Hipotálamo/efeitos dos fármacos , Imuno-Histoquímica/métodos , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neurônios/metabolismo , Fosfopiruvato Hidratase/metabolismo , Ratos , Fatores de Tempo
12.
Brain Res ; 981(1-2): 133-42, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-12885434

RESUMO

Acute behavioral effects of tumor necrosis factor alpha (TNFalpha) have been previously reported, however the cellular basis for these actions are unknown. To address this issue we examined the effects of TNFalpha on AMPA- and depolarization-induced changes in cytosolic Ca(2+) in cultured hippocampal neurons. Single cell Ca(2+) levels were determined with the fluorescent calcium indicator fura-2. TNFalpha caused an up-regulation of AMPA (10 microM)- and depolarization (55 mM KCl)-induced Ca(2+) responses. This effect occurred within a window of concentrations (1 and 10 ng/ml but not 0.1 or 100 ng/ml) and times (3 and 6 h but not 1 and 24 h). The effect was dependent upon protein synthesis (blocked by cycloheximide) and was prevented by the soluble TNF receptor and by a soluble TNF receptor fragment. Treatment with the soluble TNF receptor fragment also caused a decrease in the basal response. The TNFalpha treatment protocols did not appear to produce any toxicity to the neurons. Results are consistent with the hypothesis that TNFalpha regulates proteins known to be involved in neuronal communication (AMPA receptors) and cell regulation (voltage-dependent calcium channels) in a relatively rapid period of time (a few hours). These actions may be related to the behavioral effects produced by TNFalpha that occur within this time frame.


Assuntos
Cálcio/metabolismo , Fármacos Atuantes sobre Aminoácidos Excitatórios/farmacologia , Hipocampo/citologia , Neurônios/efeitos dos fármacos , Cloreto de Potássio/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico/farmacologia , 6-Ciano-7-nitroquinoxalina-2,3-diona/farmacologia , Agatoxinas , Animais , Animais Recém-Nascidos , Bloqueadores dos Canais de Cálcio/farmacologia , Células Cultivadas , Cicloeximida/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Antagonistas de Aminoácidos Excitatórios/farmacologia , Fura-2/metabolismo , Camundongos , Neurônios/metabolismo , Fragmentos de Peptídeos/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , Ratos , Receptores do Fator de Necrose Tumoral/metabolismo , Venenos de Aranha/farmacologia , ômega-Conotoxina GVIA/farmacologia
13.
Alcohol Clin Exp Res ; 26(9): 1420-9, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12351938

RESUMO

BACKGROUND: Alcohol drinking is known to cause hyperprolactinemia in both humans and laboratory animals. The mechanism by which alcoholism causes hyperprolactinemia is not known. This study investigated whether increased pituitary production of prolactin, which leads to alcohol-induced hyperprolactinemia, results from an increase in cell number and/or cell production of prolactin in the pituitary. METHODS: The effects of ethanol on lactotropes were determined in vivo using female rats as an animal model and in vitro using primary cultures of mixed rat anterior pituitary cells and enriched lactotropes. In vivo experiments involved administration of ethanol for 2 and 4 weeks using a liquid diet containing 8.7% ethanol (v/v), which provides 37% of the calories in cyclic, ovariectomized, and estradiol-17beta-treated ovariectomized Fischer-344 rats. The control group was pair-fed an isocaloric diet minus the ethanol or fed a normal diet ad libitum. These animals were used to determine ethanol's effects on plasma prolactin levels, pituitary wet weights, pituitary total protein levels, and the number of mitotic lactotropes. In vitro studies determined ethanol's effects in the presence and absence of estradiol on prolactin release and lactotropic cell proliferation. Prolactin levels in plasma and media samples were measured using radioimmunoassay. Mitotic lactotropes were determined using bromodeoxyuridine incorporation assay. RESULTS: Ethanol treatment increased in a time-dependent manner the plasma levels of prolactin in cyclic, ovariectomized, and estradiol-treated ovariectomized rats. Ethanol treatment also increased pituitary wet weight and/or pituitary total protein levels and DNA synthesis in lactotropes. Determination of ethanol's action on lactotropic cell proliferation and hormone secretion in vitro using primary cultures of mixed pituitary cells revealed that ethanol stimulated both basal and estradiol-induced prolactin secretion and lactotropic cell proliferation. When ethanol's actions were studied in isolated lactotropes, ethanol alone or in combination with estradiol stimulated prolactin secretion but failed to increase lactotropic cell proliferation. CONCLUSIONS: These results suggest that ethanol causes hyperprolactinemia by elevating prolactin release from lactotropes and by increasing the number of lactotropes in the anterior pituitary gland. The mitotic action of ethanol requires cell-cell communication between lactotropes and other pituitary cells. Furthermore, ethanol's mode of action on prolactin release and lactotrope growth is similar to that observed for estradiol.


Assuntos
Etanol/farmacologia , Hiperprolactinemia/induzido quimicamente , Adeno-Hipófise/efeitos dos fármacos , Prolactina/metabolismo , Animais , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Etanol/toxicidade , Feminino , Hiperprolactinemia/metabolismo , Ovariectomia , Adeno-Hipófise/citologia , Adeno-Hipófise/metabolismo , Prolactina/biossíntese , Ratos , Ratos Endogâmicos F344
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA