RESUMEN
Investigation of acetaminophen (APAP)-induced liver damage recently indicated the significance of phagocytic NADPH oxidase (NOX)-derived reactive oxygen species (ROS) and ferroptosis in the liver. Here, we focused on phagocytosis by iron-containing erythrocyte-devouring splenic macrophages and explored upstream factors of known APAP hepatotoxic mechanisms in vivo. Splenectomy did not alter hepatic cytochrome P450 (CYP) 2E1 activity or hepatic glutathione (GSH) content. APAP injection into splenectomized mice almost completely suppressed increases in plasma alanine aminotransferase levels and centrilobular hepatic necrosis showing the spleen to be a critical tissue in APAP-induced liver damage. Hepatic GSH was recovered to approximately 50 % content at 8 h. In non-splenectomized mice, liver damage was dramatically suppressed by a sensitive redox probe (DCFH-DA), macrophage-depleting clodronate (CL), and a NOX2 inhibitor. APAP treatment resulted in markedly stronger fluorescence intensity from DCFH-DA due to excessive ROS around splenic macrophages, which was lost upon co-treatment with a CYP inhibitor and CL. Deformed erythrocytes disappeared in mice co-treated with DCFH-DA, CL, the NOX2 inhibitor, and the CYP inhibitor. Simultaneously, these four compounds significantly improved APAP-depleted GSH levels. The CYP inhibitor also prevented the formation of APAP-cell adducts in the blood and spleen. In the spleen, CL co-treatment markedly reduced the number of adducts. Splenic ferrous iron levels were significantly elevated by APAP. Therefore, we demonstrated that splenic macrophages devoured APAP metabolite-erythrocyte adducts and subsequently splenic macrophage-related ROS caused sustained hepatic GSH depletion and excessive erythrocyte deformation around 7 h. Our data indicate in vivo upstream factors of known APAP hepatotoxic mechanisms.
Asunto(s)
Acetaminofén , Enfermedad Hepática Inducida por Sustancias y Drogas , Eritrocitos , Glutatión , Hígado , Macrófagos , Especies Reactivas de Oxígeno , Bazo , Animales , Acetaminofén/toxicidad , Especies Reactivas de Oxígeno/metabolismo , Glutatión/metabolismo , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Ratones , Bazo/efectos de los fármacos , Bazo/metabolismo , Bazo/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Eritrocitos/metabolismo , Eritrocitos/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Ratones Endogámicos C57BL , Esplenectomía , Fagocitosis/efectos de los fármacos , NADPH Oxidasa 2/metabolismo , Ácido Clodrónico/farmacologíaRESUMEN
The RNA-binding protein HuD/ELAVL4 is essential for neuronal development and synaptic plasticity by governing various post-transcriptional processes of target mRNAs, including stability, translation, and localization. We previously showed that the linker region and poly(A)-binding domain of HuD play a pivotal role in promoting translation and inducing neurite outgrowth. In addition, we found that HuD interacts exclusively with the active form of Akt1, through the linker region. Although this interaction is essential for neurite outgrowth, HuD is not a substrate for Akt1, raising questions about the dynamics between HuD-mediated translational stimulation and its association with active Akt1. Here, we demonstrate that active Akt1 interacts with the cap-binding complex via HuD. We identify key amino acids in linker region of HuD responsible for Akt1 interaction, leading to the generation of two point-mutated HuD variants: one that is incapable of binding to Akt1 and another that can interact with Akt1 regardless of its phosphorylation status. In vitro translation assays using these mutants reveal that HuD-mediated translation stimulation is independent of its binding to Akt1. In addition, it is evident that the interaction between HuD and active Akt1 is essential for HuD-induced neurite outgrowth, whereas a HuD mutant capable of binding to any form of Akt1 leads to aberrant neurite development. Collectively, our results revisit the understanding of the HuD-Akt1 interaction in translation and suggest that this interaction contributes to HuD-mediated neurite outgrowth via a unique molecular mechanism distinct from translation regulation.
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Proteína 4 Similar a ELAV , Neuronas , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteína 4 Similar a ELAV/metabolismo , Proteína 4 Similar a ELAV/genética , Humanos , Animales , Neuronas/metabolismo , Neuronas/citología , Diferenciación Celular , Células HEK293 , Unión Proteica , Fosforilación , Ratones , Neurogénesis , Ratas , Neuritas/metabolismoRESUMEN
Translation initiation is the rate-limiting step of protein synthesis and is the main target of translation regulation. RNA-binding proteins (RBPs) are key mediators of the spatiotemporal control of translation and are critical for cell proliferation, development, and differentiation. We have previously shown that HuD, one of the neuronal RBPs, enhances cap-dependent translation through the direct interaction with eukaryotic initiation factor 4A (eIF4A) and poly(A) tail using a HeLa-derived in vitro translation system. We have also found that translation stimulation of HuD is essential for HuD-induced neurite outgrowth in PC12 cells. However, it remains unclear how HuD is involved in the regulation of translation initiation. Here, we report that HuD binds to eukaryotic initiation factor 3 (eIF3) via the eIF3b subunit, which belongs to the functional core of mammalian eIF3. eIF3 plays an essential role in recruiting the 40S ribosomal subunit onto mRNA in translation initiation. We hypothesize that the interaction between HuD and eIF3 stabilizes the translation initiation complex and increases translation efficiency. We also showed that the linker region of HuD is required for the interaction with eIF3b. Moreover, we found that eIF3b-binding region of HuD is conserved in all Hu proteins (HuB, HuC, HuD, and HuR). These data might also help to explain how Hu proteins stimulate translation in a cap- and poly(A)-dependent way.
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Factor 3 de Iniciación Eucariótica , Factores Eucarióticos de Iniciación , Animales , Humanos , Ratas , Factor 3 de Iniciación Eucariótica/genética , Factor 3 de Iniciación Eucariótica/metabolismo , Factores Eucarióticos de Iniciación/metabolismo , Neuronas/metabolismo , Factor 3 Procariótico de Iniciación/genética , Factor 3 Procariótico de Iniciación/metabolismo , Unión Proteica , Biosíntesis de Proteínas , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Células HeLaRESUMEN
[This corrects the article DOI: 10.3389/fgene.2019.00332.].
RESUMEN
Eukaryotic gene expression can be spatiotemporally tuned at the post-transcriptional level by cis-regulatory elements in mRNA sequences. An important example is the AU-rich element (ARE), which induces mRNA destabilization in a variety of biological contexts in mammals and can also mediate translational control. Regulation is mediated by trans-acting factors that recognize the ARE, such as Tristetraprolin (TTP) and BRF1/ZFP36L1. Although both proteins can destabilize their target mRNAs through the recruitment of the CCR4-NOT deadenylation complex, TTP also directly regulates translation. Whether ZFP36L1 can directly repress translation remains unknown. Here, we used an in vitro translation system derived from mammalian cell lines to address this key mechanistic issue in ARE regulation by ZFP36L1. Functional assays with mutant proteins reveal that ZFP36L1 can repress translation via AU-Rich elements independent of deadenylation. ZFP36L1-mediated translation repression requires interaction between ZFP36L1 and CNOT1, suggesting that it might use a repression mechanism similar to either TPP or miRISC. However, several lines of evidence suggest that the similarity ends there. Unlike, TTP, it does not efficiently interact with either 4E-HP or GIGYF2, suggesting it does not repress translation by recruiting these proteins to the mRNA cap. Moreover, ZFP36L1 could not repress ECMV-IRES driven translation and was resistant to pharmacological eIF4A inhibitor silvestrol, suggesting fundamental differences with miRISC repression via eIF4A. Collectively, our results reveal that ZFP36L1 represses translation directly and suggest that it does so via a novel mechanism distinct from other translational regulators that interact with the CCR4-NOT deadenylase complex.
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Factor 1 de Respuesta al Butirato/metabolismo , Regulación de la Expresión Génica , Biosíntesis de Proteínas , Factores de Transcripción/metabolismo , Elementos Ricos en Adenilato y Uridilato , Células HEK293 , Humanos , Unión ProteicaRESUMEN
RNA-binding proteins (RBPs) are key regulators of posttranscriptional gene expression and control many important biological processes including cell proliferation, development, and differentiation. RBPs bind specific motifs in their target mRNAs and regulate mRNA fate at many steps. The AU-rich element (ARE) is one of the major cis-regulatory elements in the 3' untranslated region (UTR) of labile mRNAs. Many of these encode factors requiring very tight regulation, such as inflammatory cytokines and growth factors. Disruption in the control of these factors' expression can cause autoimmune diseases, developmental disorders, or cancers. Therefore, these mRNAs are strictly regulated by various RBPs, particularly ARE-binding proteins (ARE-BPs). To regulate mRNA metabolism, ARE-BPs bind target mRNAs and affect some factors on mRNAs directly, or recruit effectors, such as mRNA decay machinery and protein kinases to target mRNAs. Importantly, some ARE-BPs have stabilizing roles, whereas others are destabilizing, and ARE-BPs appear to compete with each other when binding to target mRNAs. The function of specific ARE-BPs is modulated by posttranslational modifications (PTMs) including methylation and phosphorylation, thereby providing a means for cellular signaling pathways to regulate stability of specific target mRNAs. In this review, we summarize recent studies which have revealed detailed molecular mechanisms of ARE-BP-mediated regulation of gene expression and also report on the importance of ARE-BP function in specific physiological contexts and how this relates to disease. We also propose an mRNP regulatory network based on competition between stabilizing ARE-BPs and destabilizing ARE-BPs.
RESUMEN
Many viruses strongly prefer to infect certain cell types, a phenomenon known as "tropism." Understanding tropism's molecular basis is important for the design of vaccines and antiviral therapy. A common mechanism involves viral protein interactions with cell-specific surface receptors, but intracellular mechanisms involving translation have also been described. In this report, we focus on Hepatitis A Virus (HAV) tissue tropism from the standpoint of the translational machinery. HAV genomic RNA, like other positive stranded RNA viruses, is devoid of a cap structure and its translation is driven by highly structured RNA sequences termed internal ribosome entry site (IRES) in the 5' untranslated region (UTR). Unlike most viral IRESs, HAV IRES-mediated translation requires eIF4E and the 3' end of HAV RNA is polyadenylated. However, the molecular mechanism of HAV IRES-mediated translation initiation remains poorly understood. We analyzed HAV-IRES-mediated translation in a cell-free system derived from either non-hepatic cells (HeLa) or hepatoma cells (Huh-7) that enables investigation of the contribution of the cap and the poly(A) tail. This revealed that HAV IRES-mediated translation activity in hepatoma cell extracts is higher as compared to extracts derived from a non-hepatic line. Our data suggest that HAV IRES-mediated translation is upregulated by a hepatic cell-specific activator in a poly(A) tail-independent manner.
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We examined the effect of repeated cold (RC) stress on cyclophosphamide (CPA)-induced cystitis/bladder pain in mice, in relation to macrophage activity. CPA, given i.p. at 400 mg/kg, caused bladder pain symptoms accompanying cystitis in both unstressed and RC-stressed mice, which were prevented by the macrophage inhibitor minocycline. A low dose, that is, 200 mg/kg, of CPA still produced bladder pain symptoms in unstressed but not RC-stressed mice. Lipopolysaccharide-induced cytokine production in peritoneal macrophages from RC-stressed mice was less than that from unstressed mice. Thus, RC stress appears to reduce CPA-induced bladder pain in mice, which may be associated with the decreased macrophage activity.
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Frío , Ciclofosfamida/efectos adversos , Cistitis/inducido químicamente , Cistitis/inmunología , Activación de Macrófagos/efectos de los fármacos , Dolor/inducido químicamente , Estrés Fisiológico , Vejiga Urinaria/efectos de los fármacos , Animales , Citocinas/metabolismo , Lipopolisacáridos/farmacología , Macrófagos/metabolismo , Masculino , Ratones , Minociclina/farmacología , Dolor/inmunología , Vejiga Urinaria/inmunologíaRESUMEN
Lipopolysaccharide (LPS) induces hyperthermia accompanied by various other systemic inflammatory symptoms. The rodents exposed to repeated cold (RC) stress according to a specific schedule are useful as experimental models for autonomic imbalance or fibromyalgia. It is now proven that RC-stressed mice exhibit tolerance to LPS, we examined thermal responses to LPS challenge in RC-stressed mice by monitoring core temperature using the telemetry system. Systemic administration of LPS caused bimodal hyperthermic responses in RC-stressed and unstressed mice. The magnitude of the LPS-induced hyperthermia was greater in RC-stressed mice than in unstressed mice. The RC stress-induced enhancement of hyperthermic responses to LPS was abolished by pretreatment with diclofenac, which is a cyclooxygenase (COX) inhibitor. LPS did not significantly increase COX-2 protein levels in the lung or hypothalamus of RC-stressed or unstressed mice. RC stress did not alter baseline serum corticosterone levels or their increases in response to LPS challenge. These results suggest that RC stress enhances the susceptibility of mice to LPS challenge, leading to greater prostanoid-dependent hyperthermia, which might contribute to tolerance to LPS in RC-stressed mice.
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Ritmo Circadiano/fisiología , Frío/efectos adversos , Lipopolisacáridos/toxicidad , Estrés Psicológico/metabolismo , Estrés Psicológico/psicología , Animales , Temperatura Corporal/fisiología , Corticosterona/sangre , Ciclooxigenasa 2/biosíntesis , Masculino , RatonesRESUMEN
The rodents exposed to repeated cold stress according to a specific schedule, known as specific alternation of rhythm in temperature (SART), exhibit autonomic imbalance, and is now used as an experimental model of fibromyalgia. To explore the susceptibility of SART-stressed animals to novel acute stress, we tested whether exposure of mice to SART stress for 1 week alters the extent of acute restraint stress-induced hyperthermia. Mice were subjected to 7-d SART stress sessions; i.e., the mice were alternately exposed to 24 and 4°C at 1-h intervals during the daytime (09:00-16:00) and kept at 4°C overnight (16:00-09:00). SART-stressed and unstressed mice were exposed to acute restraint stress for 20-60 min, during which rectal temperature was monitored. Serum corticosterone levels were measured before and after 60-min exposure to restraint stress. SART stress itself did not alter the body temperature or serum corticosterone levels in mice. Acute restraint stress increased the body temperature and serum corticosterone levels, both responses being greater in SART-stressed mice than unstressed mice. The enhanced hyperthermic responses to acute restraint stress in SART-stressed mice were significantly attenuated by SR59230A, a ß3 adrenoceptor antagonist, but unaffected by diazepam, an anxiolytic, mifepristone, a glucocorticoid receptor antagonist, or indomethacin, a cyclooxygenase inhibitor. These results suggest that SART stress enhances the susceptibility of mice to acute restraint stress, characterized by increased hyperthermia and corticosterone secretion, and that the increased hyperthermic responses to acute stress might involve accelerated activation of sympathetic ß3 adrenoceptors, known to regulate non-shivering thermogenesis in the brown adipose tissue.
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Frío , Fiebre , Restricción Física , Estrés Fisiológico , Estrés Psicológico , Tejido Adiposo Pardo , Antagonistas de Receptores Adrenérgicos beta 3 , Animales , Ansiolíticos/farmacología , Corticosterona/sangre , Diazepam/farmacología , Fiebre/sangre , Fiebre/tratamiento farmacológico , Fiebre/metabolismo , Masculino , Ratones , Mifepristona/farmacología , Propanolaminas/farmacología , Receptores de Glucocorticoides/antagonistas & inhibidores , Estrés Psicológico/sangre , Estrés Psicológico/tratamiento farmacológico , Estrés Psicológico/metabolismo , Proteína Desacopladora 1/metabolismoRESUMEN
It was reported that cilostazol (CLZ) suppressed disruption of the microvasculature in ischemic areas. In this study, we have designed novel injection formulations containing CLZ nanoparticles using 0.5% methylcellulose, 0.2% docusate sodium salt, and mill methods (CLZnano dispersion; particle size 81 ± 59 nm, mean ± S.D.), and investigated their toxicity and usefulness in a cerebral ischemia/reperfusion-induced injury model (MCAO/reperfusion mice). The pharmacokinetics of injections of CLZnano dispersions is similar to that of CLZ solutions prepared with 2-hydroxypropyl-ß-cyclodextrin, and no changes in the rate of hemolysis of rabbit red blood cells, a model of cell injury, were observed with CLZnano dispersions. In addition, the intravenous injection of 0.6 mg/kg CLZnano dispersions does not affect the blood pressure and blood flow, and the 0.6 mg/kg CLZnano dispersions ameliorate neurological deficits and ischemic stroke in MCAO/reperfusion mice. It is possible that the CLZnano dispersions will provide effective therapy for ischemic stroke patients, and that injection preparations of lipophilic drugs containing drug nanoparticles expand their therapeutic usage.
Asunto(s)
Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Nanopartículas/administración & dosificación , Fármacos Neuroprotectores/administración & dosificación , Daño por Reperfusión/tratamiento farmacológico , Tetrazoles/administración & dosificación , Administración Intravenosa , Animales , Presión Sanguínea , Encéfalo/irrigación sanguínea , Encéfalo/efectos de los fármacos , Encéfalo/patología , Cilostazol , Masculino , Ratones Endogámicos ICR , Fármacos Neuroprotectores/farmacocinética , Conejos , Ratas Wistar , Tetrazoles/farmacocinéticaRESUMEN
OBJECTIVES: The objective of this study was to address the beneficial effects of Cistanche tubulosa extract on improving the low intestinal permeability of echinacoside (ECH) and acteoside (ACT). METHODS: Absorption of ECH and ACT in C. tubulosa extract was characterized using human intestinal Caco-2 cell monolayers with intact compounds. Glucose transporter-dependent absorption of ECH and ACT was confirmed by an in-situ intestinal perfusion technique. KEY FINDINGS: The apparent permeability (Papp ) was not significantly different between intact ECH and intact ACT. In the presence of phloridzin, the Pap p of the ECH and ACT at a high dose was reduced to 20% of the respective non-treatment, but was not altered by phloretin and verapamil. C. tubulosa extract at low and high doses enhanced the Papp of ECH and ACT (both by threefold), resulting in their large participation in sodium-dependent glucose transporter-independent absorption. At a low concentration, concomitant ECH and ACT levels in portal blood were significantly suppressed by phloridzin. CONCLUSION: The dietary and medicinal C. tubulosa extract enhancing the intestinal absorption of ECH and ACT may serve to better manage human health, although the involvement of phloridzin-sensitive transport should be reduced.
Asunto(s)
Cistanche/química , Glucósidos/farmacocinética , Glicósidos/farmacocinética , Fenoles/farmacocinética , Extractos Vegetales/farmacología , Animales , Células CACO-2 , Relación Dosis-Respuesta a Droga , Glucósidos/administración & dosificación , Glicósidos/administración & dosificación , Humanos , Absorción Intestinal/efectos de los fármacos , Masculino , Fenoles/administración & dosificación , Floretina/farmacología , Florizina/administración & dosificación , Florizina/farmacología , Extractos Vegetales/administración & dosificación , Ratas , Ratas Wistar , Proteínas de Transporte de Sodio-Glucosa/metabolismo , Verapamilo/farmacologíaRESUMEN
Hypercalcemia is often observed in postmenopausal women as well as in patients with primary hyperparathyroidism or malignant tumors. In this study, we investigated the relationship between calcium ion (Ca(2+)) levels in lacrimal fluid and the rate of corneal wound healing in hypercalcemia using ovariectomized (OVX) rat debrided corneal epithelium. We also determined the effects of Ca(2+) levels on cell adhesion, proliferation and viability in a human cornea epithelial cell line (HCE-T). The calcium content in bones of OVX rats decreased after ovariectomy. Moreover, the Ca(2+) content in the blood of OVX rats was increased 1 month after ovariectomy, and decreased. The Ca(2+) content in the lacrimal fluid of OVX rats was also increased after ovariectomy, and then decreased similarly as in blood. Corneal wound healing in OVX rats was delayed in comparison with Sham rats (control rats), and a close relationship was observed between the Ca(2+) levels in lacrimal fluid and the rate of corneal wound healing in Sham and OVX rats (y=-0.7863x+8.785, R=0.78, n=25). In addition, an enhancement in Ca(2+) levels caused a decrease in the viability in HCE-T cells. It is possible that enhanced Ca(2+) levels in lacrimal fluid may cause a decrease in the viability of corneal epithelial cells, resulting in a delay in corneal wound healing. These findings provide significant information that can be used to design further studies aimed at reducing corneal damage of patients with hypercalcemia.
Asunto(s)
Calcio/metabolismo , Epitelio Corneal/lesiones , Hipercalcemia/metabolismo , Lágrimas/metabolismo , Cicatrización de Heridas/fisiología , Animales , Calcio/sangre , Adhesión Celular , Línea Celular , Proliferación Celular , Supervivencia Celular , Epitelio Corneal/metabolismo , Femenino , Fémur/metabolismo , Humanos , Ovariectomía , Ratas WistarRESUMEN
OBJECTIVES: 2-Arylpropionic acid (profen) drugs are associated with severe hepatotoxicity; however, risk factors are still poorly understood. Acyl-coenzyme A (acyl-CoA) thioesters of profen drugs play a more important role in the covalent binding to rat hepatocyte proteins than the respective acyl-glucuronides. Therefore, we examined whether acyl-glucuronides, acyl-CoA thioesters and oxidative metabolites of profen drugs stereoselectively participated in liver damage. METHODS: Cytotoxicity was determined by measuring lactate dehydrogenase (LDH) leakage from three-dimensional cultured rat hepatocytes. KEY FINDINGS: LDH leakage was not induced by R-2-phenylpropionic acid and R-ibuprofen greatly forming acyl-CoA thioesters. S-Naproxen metabolized mainly by Uridine 5'-diphosphate (UDP)-glucuronosyl-transferase did not enhance LDH leakage. However, flurbiprofen (FLP) induced LDH leakage. A selective cytochrome P450 (CYP) 2C11 inhibitor suppressed 40-50% of the R-FLP and S-FLP-induced cytotoxicity. Borneol non-stereoselectively accelerated the FLP-induced cytotoxicity. The R-FLP-induced cytotoxicity decreased intracellular adenosine triphosphate (ATP) levels to 50% of untreated hepatocytes. An inhibitor of mitochondrial permeability transition pore, cyclosporin A (Cys A), rescued ATP levels and LDH leakage back to control levels. CONCLUSION: The reactive acyl-CoA thioesters and acyl-glucuronides were not associated with liver damage, denying one of the leading hypotheses. CYP metabolism of FLP non-stereoselectively participated in Cys A-sensitive cytotoxicity, suggesting mitochondrial injury.
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Ciclosporina/farmacología , Sistema Enzimático del Citocromo P-450/metabolismo , Flurbiprofeno/toxicidad , Hepatocitos/efectos de los fármacos , Adenosina Trifosfato/farmacología , Animales , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Hepatocitos/metabolismo , Ibuprofeno/toxicidad , L-Lactato Deshidrogenasa/metabolismo , Masculino , Mitocondrias/patología , Naproxeno/toxicidad , Fenilpropionatos/toxicidad , Ratas , Ratas Wistar , EstereoisomerismoRESUMEN
Oxaliplatin is a key drug commonly used in colorectal cancer treatment. Despite high clinical efficacy, its therapeutic application is limited by common, dose-limiting occurrence of neuropathy. As usual symptomatic neuropathy treatments fail to improve the patients' condition, there is an urgent need to advance our understanding of the pathogenesis of neuropathy to propose effective therapy and ensure adequate pain management. Oxaliplatin-induced neuropathy was recently reported to be associated with protein kinase C (PKC) activation. It is unclear, however, whether PKC inhibition can prevent neuropathy. In our current studies, we found that a PKC inhibitor, tamoxifen, inhibited oxaliplatin-induced neuropathy via the PKC/extracellular signal-regulated kinase (ERK)/c-Fos pathway in lumbar spinal cords (lumbar segments 4-6). Additionally, tamoxifen was shown to act in synergy with oxaliplatin to inhibit growth in tumor cells-implanted mice. Moreover, mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, PD0325901, suppressed oxaliplatin-induced neuropathy and enhanced oxaliplatin efficacy. Our results indicate that oxaliplatin-induced neuropathy is associated with PKC/ERK/c-Fos pathway in lumbar spinal cord. Additionally, we demonstrate that disruption of this pathway by PKC and MEK inhibitors suppresses oxaliplatin-induced neuropathy, thereby suggesting that PKC and MEK inhibitors may be therapeutically useful in preventing oxaliplatin-induced neuropathy and could aid in combination antitumor pharmacotherapy.
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Neoplasias Colorrectales/tratamiento farmacológico , Hiperalgesia/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Compuestos Organoplatinos/administración & dosificación , Inhibidores de Proteínas Quinasas/administración & dosificación , Médula Espinal/efectos de los fármacos , Animales , Benzamidas/administración & dosificación , Benzamidas/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Difenilamina/administración & dosificación , Difenilamina/análogos & derivados , Difenilamina/farmacología , Modelos Animales de Enfermedad , Sinergismo Farmacológico , Hiperalgesia/inducido químicamente , Hiperalgesia/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Compuestos Organoplatinos/efectos adversos , Oxaliplatino , Inhibidores de Proteínas Quinasas/farmacología , Médula Espinal/patología , Tamoxifeno/administración & dosificación , Tamoxifeno/farmacologíaRESUMEN
Hiccups are often observed in patients treated with cisplatin(CDDP)-based chemotherapy. It has been reported that gender and specific dosages of CDDP and antiemetic drugs(e.g., dexamethasone and 5-HT3 receptor antagonist)using standard therapy are major risk factors in the onset of hiccups. Recently, aprepitant has been added to the antiemetic therapy in CDDP-based chemotherapy. However, it is not known how the onset of hiccups takes place in antiemetic therapy including aprepitant according to the guideline. In this study, we used cluster analysis to classify 229 patients treated with CDDP-based chemotherapy, to investigate the effect of antiemetic therapy on the onset of hiccups and chemotherapy-induced nausea and vomiting(CINV). Our analysis indicated that aprepitant was not a major risk factor for the onset of hiccups in the high CDDP dose group(≥70 mg/m(2)). However, an effect of antiemesis was confirmed in the standard therapy with aprepitant. In conclusion, we suggest that aprepitant is effective for CINV, without causing the onset of hiccups in patients treated with high-dose CDDP-based chemotherapy.
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Antieméticos/uso terapéutico , Antineoplásicos/efectos adversos , Cisplatino/efectos adversos , Dexametasona/uso terapéutico , Hipo/tratamiento farmacológico , Antagonistas del Receptor de Serotonina 5-HT3/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Cisplatino/uso terapéutico , Análisis por Conglomerados , Femenino , Hipo/inducido químicamente , Hipo/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Receptores de Serotonina 5-HT3/metabolismo , Factores de RiesgoRESUMEN
Previous work from this laboratory has shown that the serotonin (5-HT) induced response is significantly augmented in differentiated NG108-15 (NG) cells treated with dibutyryl cAMP (Bt(2)cAMP) due to qualitative and quantitative changes in the expression of the 5-HT(3) receptor as demonstrated by specific [(3)H] LY-278584 (a selective 5HT(3) receptor antagonist) binding. In this study, we investigated whether there is any change in the relative expression of the 5-HT(3A) and 5-HT(3B) subunits in NG cells differentiated following Bt(2)cAMP treatment cells. The major findings of this study were that the relative amount of 5-HT(3B) subunit mRNA in Bt(2)cAMP-treated NG cells 5 days following Bt(2)cAMP-treatment was greater than that in the untreated cells. In contrast, the relative expression of the 5-HT(3B) subunit protein in the Bt(2)cAMP-treated NG cells was much less than in the untreated cells, but the relative expression of the 5-HT(3A) subunit in the Bt(2)cAMP-treated NG cells was similar to the untreated cells. Therefore, no relationship between mRNA and protein expression for 5-HT(3A) and 5-HT(3B) subunits in Bt(2)cAMP treated and untreated NG cells were observed. It was also found that fluorescent intensity for the 5-HT(3B) subunit in the cell body of the Bt(2)cAMP treated and untreated NG cells gradually decreased from the day 1-5 after Bt(2)cAMP treatment. However, in specific areas such as the varicosity and nerve endings of the Bt(2)cAMP treated cells, staining intensity for the 5-HT(3B) subunits was stronger than in the untreated cells at the all time points, peaking at day 5 post-treatment. These results suggest that the augmented response induced by 5-HT acting via 5-HT(3) receptors in differentiated NG cells may be due to changes in the relative amount of the 5-HT(3B) subunit, particularly the ratio and distribution of the 5-HT(3A) to (3B) subunits.
Asunto(s)
Receptores de Serotonina 5-HT3/biosíntesis , Animales , Bucladesina/farmacología , Diferenciación Celular , Indazoles , Ratones , Subunidades de Proteína/biosíntesis , ARN Mensajero/metabolismo , Ratas , TropanosRESUMEN
BACKGROUND: Specific alternation of rhythm in temperature (SART)-stressed rats, an animal model of autonomic imbalance, exhibit low blood pressure and tachycardia during consciousness and under anesthesia. In addition, these rats easily develop orthostatic hypotension (OH) as a response to postural manipulation. Hence, we studied the influence of the adrenalin α1-receptor agonist phenylephrine on stress-induced OH in SART-stressed rats and unstressed rats. METHODS: Male Wistar rats weighing 250-300 g were used. Rats were fixed in the supine position under urethane anesthesia. Blood pressure was directly measured from the left common carotid artery and ECG was recorded simultaneously. RESULTS: The maximum decrease in blood pressure and the area under the blood pressure-time curve were both large, while the %reflex was small in the SART-stressed rats compared with unstressed rats. In the SART-stressed rats, prolonged intravenous administration of phenylephrine reduced OH at a dose that barely affected unstressed rats. CONCLUSION: The results suggested that sympathetic dysfunction is a factor underlying SART stress-induced OH.
RESUMEN
Stress is closely associated with the manifestation and progress of irritable bowel syndrome (IBS). For the purpose of establishing experimentally the relationship between IBS and stress, the transportation capacity of the small intestine in specific alternation of rhythm in temperature (SART)-stressed animals was studied using charcoal transportation method. The charcoal suspension was administered orally into the stomach of fasting mice. Mice were sacrificed after a certain time and %charcoal transit (%CT) of the small intestine was measured. The %CTs in SART-stressed mice were greater than those in unstressed or continuously cold-stressed mice. This increase in %CT remained for 1 week after discontinuation of SART stress loading. Cholinergic blockers decreased %CTs in SART-stressed mice. Increases in %CT by a cholinesterase inhibitor were less in SART-stressed mice than in unstressed mice. Increases of %CT in SART-stressed mice were suppressed by Neurotropine. These results suggested that the parasympathetic hypertonicity, not just cold, played a role in the increases in the transportation capacity in SART-stressed mice and that these animals can be a useful tool for elucidation of the mechanism of IBS.
Asunto(s)
Antagonistas Colinérgicos/farmacología , Frío/efectos adversos , Síndrome del Colon Irritable/fisiopatología , Estrés Fisiológico/efectos de los fármacos , Estrés Fisiológico/fisiología , Animales , Tránsito Gastrointestinal/efectos de los fármacos , Tránsito Gastrointestinal/fisiología , Síndrome del Colon Irritable/tratamiento farmacológico , Masculino , RatonesRESUMEN
We have reported previously that the concentration of intracellular Ca2+ evoked by serotonin (5-HT) was significantly augmented in differentiated NG108-15 (NG) cells treated with dibutyryl cAMP and the enhanced response occurred via 5-HT3 receptors. We investigated changes in the characteristics for specific binding of [(3)H]LY-278584 (a specific antagonist of the 5-HT3 receptor) on membranes from differentiated NG cells. The results indicated that the K(d) and B(max) values for the specific binding to differentiated NG cells were significantly smaller and larger, respectively, than those for undifferentiated NG cells. The binding was significantly inhibited by 10 nM tropisetron, a specific 5-HT3-receptor antagonist, but not by any other types of 5-HT-receptor antagonists. These results suggested that the enhanced response by 5-HT in differentiated NG cells was due to both qualitative and quantitative changes in the 5-HT3 receptor.