RESUMO
BACKGROUND: The Subaxial Cervical Spine Injury Classification System (SLICS) is a commonly used algorithm for diagnosing and managing subaxial cervical spine trauma. A SLIC score 4 suggests either surgery or non-surgically treatment depending on the surgeon's experience and patient's conditions. OBJECTIVE: Prognosis and treatment results were analyzed in patients with SLIC score 4. METHODS: The patients with SLIC score 4 were retrospectively reviewed from 2012 to 2019. Forty-one patients were included and divided into two groups: non-surgically treated and surgically treated. Demographic data and radiographs were analyzed. Statistical analysis was performed to determine the difference between the two clinical groups. RESULTS: Twenty-two patients were non-surgically treated, and nineteen patients were surgically treated. There was no neurological deterioration in both groups. However, there was no statistically significant difference in the last follow-up AISA and Nurick grade (p> 0.05). There was no significant difference in the number of patients who showed improvement when comparing the initial and the last follow-up neurological status (p> 0.05). CONCLUSION: Regardless of the treatment method, the spinal cord injury patients with SLICS point 4 showed a relatively good prognosis. Patients with SLIC score 4 could be treated non-surgically or surgically based on the surgeon's experience and factors associated with the patient's acute health status and chronic comorbidities.
Assuntos
Lesões do Pescoço , Traumatismos da Medula Espinal , Traumatismos da Coluna Vertebral , Cirurgiões , Humanos , Estudos Retrospectivos , Traumatismos da Coluna Vertebral/diagnóstico por imagem , Traumatismos da Coluna Vertebral/cirurgia , Vértebras Cervicais/cirurgia , Traumatismos da Medula Espinal/complicaçõesRESUMO
In-water cleaning (IWC) involves the removal of biofilms and foulants from the hull of a ship using brush or water jet. During IWC, several factors associated with the harmful chemical contaminants release to the marine environment, which can create "hotspots" of chemical contamination in coastal areas. To elucidate the potential toxic effects of IWC discharge, we investigated developmental toxicity in embryonic flounder, which are sensitive life stage to chemical exposure. Zinc and copper were the dominant metals, while zinc pyrithione was the most abundant biocide associated with IWC discharge in two remotely operated IWC. Discharge from IWC carried by both remotely operated vehicles (ROVs) produced developmental malformations including pericardial edema, spinal curvature, and tail-fin defects. In an analyses of differential gene expression profiles (fold-change of genes with a cutoff < 0.05) as assessed by high-throughput RNA sequencing, genes associated with muscle development were commonly and significantly changed. The gene ontology (GO) of embryos exposed to IWC discharge from ROV A activities highly enriched muscle and heart development, while cell signaling and transport were evident in embryos exposed to IWC discharge of ROV B. We analyzed the gene network by significant GO terms. In the network, TTN, MYOM1, CASP3, and CDH2 genes appeared to be key regulators of the toxic effects on muscle development. In embryos exposed to ROV B discharge, HSPG2, VEGFA, and TNF genes related to the nervous system pathway were affected. These results shed light on the potential impacts of muscle and nervous system development in non-target coastal organisms exposed to contaminants found in IWC discharge.
Assuntos
Procedimentos Cirúrgicos Robóticos , Poluentes Químicos da Água , Animais , Água/química , Peixes , Metais/farmacologia , Biofilmes , Poluentes Químicos da Água/análise , Embrião não MamíferoRESUMO
This study evaluates the toxic effects of dietary Cd and mitigative effects of AsA supplementation by measuring the growth performance, bioaccumulation, hematological parameters, plasma components, and antioxidant responses of Starry flounder (Platichthys stellatus). Platichthys stellatus (mean weight, 69.5 ± 1.4 g; mean length, 18.2 ± 0.21 cm) was fed with dietary cadmium-ascorbic acid (Cd-AsA) composed of C0A0, C0A500, C0A1000, C40A0, C40A500, C40A1000, C80A0, C80A500, and C80A1000 mg of Cd-AsA per kg diet for four weeks. Our results showed that Cd accumulation significantly increased in proportion to the Cd concentration, where the highest levels were observed in the intestine, followed by the kidney, liver, and gills. Dietary AsA significantly mitigated the Cd accumulation in all tissues, and the reduction in Cd accumulation was proportional to the increase in AsA concentration. Dietary Cd has adverse effects on growth performance (body weight gain, specific growth rate, feed conversion ratio, and hepatosomatic index) and can alter the hematological parameters (red blood cell count, hematocrit, and hemoglobin), plasma components (glucose, total protein, glutamic oxaloacetic transaminase, and glutamic pyruvic transaminase), and antioxidant responses (superoxide dismutase, catalase, glutathione S-transferase, and glutathione). Dietary AsA restored the decreased growth performance parameters and the altered hematological parameters, plasma components, and antioxidant responses caused by the dietary Cd exposure. The results of this study showed that dietary Cd is toxic to P. stellatus, while dietary AsA is effective in mitigating the toxic effects of Cd.
RESUMO
We report analysis of phosphatase activity and inhibition on droplet-based microfluidic chips. Phosphatases are such attractive potential drug targets because abnormal phosphatase activity has been implicated in a variety of diseases including cancer, neurological disorders, diabetes, osteoporosis, and obesity. So far, several methods for assessing phosphatase activity have been reported. However, they require a large sample volume and additional chemical modifications such as fluorescent dye conjugation and nanomaterial conjugation, and are not cost-effective. In this study, we used an artificial phosphatase substrate 3-O-methylfluorescein phosphate as a fluorescent reporter and dual specificity phosphatase 22. Using these materials, the phosphatase assay was performed from approximately 340.4 picoliter (pL) droplets generated at a frequency of ~40 hertz (Hz) in a droplet-based microfluidic chip. To evaluate the suitability of droplet-based platform for screening phosphatase inhibitors, a dose-response inhibition study was performed with ethyl-3,4-dephostatin and the half-maximal inhibitory concentration (IC50) was calculated as 5.79 ± 1.09 µM. The droplet-based results were compared to microplate-based experiments, which showed agreement. The droplet-based phosphatase assay proposed here is simple, reproducible, and generates enormous data sets within the limited sample and reagent volumes.
Assuntos
Técnicas Analíticas Microfluídicas , Microfluídica , Bioensaio/métodos , Fosfatases de Especificidade Dupla , Inibidores Enzimáticos , Corantes Fluorescentes , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/métodosRESUMO
OBJECTIVE: Anterior approach cervical surgery is widely used for accessing C3 lesions. When operating with an anterior approach, the surgical field is obstructed by mandible. Neck extension is popular method to secure better surgical field but risk devastating neurological damage. To overcome this limited surgical field without neck extension, we adopted nasotracheal intubation and evaluated its efficiency. METHODS: We retrospectively analyzed 16 patients who underwent anterior cervical discectomy or corpectomy of C3 lesions via nasotracheal intubation. We enrolled an additional 29 patients who underwent anterior cervical discectomy or corpectomy of C3 lesions via orotracheal intubation as a control group. All patients had been diagnosed with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament. We measured the mandibular-cervical angle, which is the angle between the lower mandibular line and anterior vertebral line. RESULTS: The mandibular-cervical angle was increased by 7.3 with nasotracheal intubation compared to orotracheal intubation. CONCLUSIONS: Nasotracheal intubation is an effective surgical option for securing the surgical field without neck extension in anterior cervical surgery including C3 lesions.
RESUMO
OBJECTIVE: Osteoporosis is one of the most common causes of vertebral compression fractures (VCFs). Teriparatide, a recombinant human parathyroid hormone, is the first anabolic agent for the treatment of osteoporosis. The aim of this study was to determine whether 3 months of teriparatide could be effective for patients with osteoporotic VCF at the thoracolumbar spine. METHODS: We reviewed 25 patients with thoracolumbar osteoporotic compression fractures between July 2012 and October 2016 who could be followed up for more than 1 year. Patients were divided into 2 groups depending on the use of teriparatide: 14 patients received teriparatide through subcutaneous injection (group I) and 11 patients did not receive teriparatide (group II). Demographic data, bone mineral density, hospitalization period, changes in the visual analogue scale (VAS) score, body mass index, and medical history such as smoking, alcohol, diabetes, and steroid usage were reviewed. Radiographs were also reviewed to evaluate vertebral body compression percentages and kyphotic angles. RESULTS: Overall changes of VAS score between injury and follow-up were statistically improved in both groups at 2 to 3 weeks post-injury. However, difference in VAS improvement at a specific time between the 2 groups was not statistically significant. Overall kyphotic angle and compression percentage between injury and follow-up time were increased in group II than those in group I, although the difference between the 2 groups was not statistically significant. CONCLUSION: Three-month of teriparatide did not show protective effects on progression of fractured vertebral body collapse or kyphotic changes in patients with osteoporosis.
RESUMO
Quercetin, a polyphenol, belongs to a class of flavonoids that exerts anti-inflammatory effects. Interleukin (IL)-18 is a member of the IL-1 family cytokine that regulates immune responses and is implicated in various inflammatory skin diseases. Absent in melanoma 2 (AIM2) is a cytosolic double-stranded (ds) DNA sensor that recognizes the dsDNA of a microbial or host origin. Binding of dsDNA to AIM2 simulates caspase-1-dependent inflammasome activity, which leads to the production of IL-1ß and IL-18. Increased levels of AIM2 have been observed in patients with inflammatory skin diseases. In the current study, we investigated the issue of whether or how Quercetin attenuates poly (dA:dT), a synthetic analog of microbial dsDNA, -induced IL-18 secretion in IFN-γ-primed human keratinocytes. Treatment with 5 and 10⯵M of Quercetin inhibited the poly (dA:dT)-induced secretion of IL-18 after IFN-γ priming and before poly (dA:dT)-induced AIM2 activation. In addition, treatment with Quercetin at 10⯵M, significantly inhibited the phosphorylation of JAK2 and STAT1, and the nuclear translocation of phosphorylated STAT1 in poly (dA:dT)-treated and IFN-γ-primed keratinocytes. These results suggest that treatment with Quercetin inhibits the poly (dA:dT)-induced secretion of IL-18 via down-regulation of the expressions of AIM2 and pro-caspase-1 by inhibiting the JAK2/STAT1 pathway in IFN-γ-primed keratinocytes.
Assuntos
Caspase 1/metabolismo , Proteínas de Ligação a DNA/metabolismo , Interleucina-18/biossíntese , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Quercetina/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Caspase 1/genética , Linhagem Celular , Células Cultivadas , Proteínas de Ligação a DNA/genética , Regulação para Baixo/efeitos dos fármacos , Humanos , Interferon gama/metabolismo , Interferon gama/farmacologia , Janus Quinase 2/metabolismo , Queratinócitos/imunologia , Poli dA-dT/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT1/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), have been widely used to control marine fouling. Here, we show that organotin stimulation reduces the hormone levels in the plasma of two economically important aquaculture fish. Blood plasma samples were collected from juvenile red seabream and black rockfish exposed to environmentally realistic concentrations of TBT and TPT for 14â¯days. The levels of two plasma biomarkers, namely the yolk protein precursor vitellogenin (VTG) and the sex steroid 17ß-estradiol (E2), were measured to determine the endocrine disrupting potential of the organotin compounds. Both organotin compounds were dose-dependently accumulated in the blood of two fish. Exposure to waterborne TBT and TBT significantly decreased the plasma VTG levels in both the juvenile fish in a dose-dependent manner. In contrast, the treatment with E2, a well-known VTG inducer, significantly increased the plasma VTG levels in both the fish. In addition, the mRNA levels of vtg were also downregulated in the liver tissues of both the fish at 100 and/or 1000â¯ngâ¯L-1 of TBT or TPT exposure. The plasma E2 titers were significantly suppressed at 100 and/or 1000â¯ngâ¯L-1 of TBT or TPT exposure for 14â¯days compared to their titer in the control. Since estrogen directly regulates vtg gene expression and VTG synthesis, our results reveal the endocrine disrupting potential of organotin compounds, and subsequently the endocrine modulation at early stage of fish can trigger further fluctuations in sexual differentiation, maturation, sex ration or egg production. In addition, the results demonstrate their effects on non-target organisms, particularly on animals reared in aquaculture and fisheries.
Assuntos
Disruptores Endócrinos/toxicidade , Estradiol/sangue , Compostos Orgânicos de Estanho/toxicidade , Percas/sangue , Dourada/sangue , Vitelogeninas/sangue , Poluentes Químicos da Água/toxicidade , Animais , Aquicultura , Biomarcadores/sangue , Antagonistas de Estrogênios/química , Antagonistas de Estrogênios/toxicidade , Feminino , Proteínas de Peixes/agonistas , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/sangue , Proteínas de Peixes/genética , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Hormese/efeitos dos fármacos , Masculino , Concentração Osmolar , Percas/crescimento & desenvolvimento , Reprodutibilidade dos Testes , República da Coreia , Dourada/crescimento & desenvolvimento , Especificidade da Espécie , Compostos de Trialquitina/toxicidade , Vitelogeninas/agonistas , Vitelogeninas/antagonistas & inibidores , Vitelogeninas/genéticaRESUMO
17ß-estradiol (E2), a key participant on the initiation of the LH surge, exerts both positive and negative feedback on GnRH neurons. We sought to investigate potential interactions between estrogen receptors alpha (ERα) and beta (ERß) and gonadotropin releasing hormone receptor (GnRH-R) in GT1-7 cells. Radioligand binding studies demonstrated a significant decrease in saturation E2 binding in cells treated with GnRH agonist. Conversely, there was a significant reduction in GnRH binding in GT1-7 cells treated with E2. In BRET(1) experiments, ERα-ERα dimerization was suppressed in GT1-7 cells treated with GnRH agonist (p < 0.05). There was no evidence of direct interaction between ERs and GnRH-R. This study provides the first evidence of reduced ERα homodimerization by GnRH agonist. Collectively, these findings demonstrate significant cross-talk between membrane-initiated GnRH and E2 signaling in GT1-7 cells.
Assuntos
Estradiol/metabolismo , Receptor alfa de Estrogênio/química , Receptor beta de Estrogênio/química , Hormônio Liberador de Gonadotropina/agonistas , Neurônios/efeitos dos fármacos , Transdução de Sinais , Sítios de Ligação , Técnicas de Transferência de Energia por Ressonância de Bioluminescência , Linhagem Celular , Estradiol/química , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Células HEK293 , Humanos , Neurônios/citologia , Multimerização Proteica/efeitos dos fármacos , Ensaio RadioliganteRESUMO
We determined the toxicity of the water accommodated hydrocarbon fraction (WAF), two chemically enhanced WAFs (CEWAFs; CEWAF-C, Crude oil+Corexit 9500 and CEWAF-H, Crude oil+Hiclean) of crude oil and two dispersants (Corexit 9500 and Hiclean) to the rock pool copepod Tigriopus japonicus. In the acute toxicity test, Corexit 9500 was the most toxic of all the chemicals studied. The nauplius stage of T. japonicus was more susceptible to the toxic chemicals studied than the adult female. The toxicity data using the nauplius stage was then considered as baseline to determine the spiking concentration of chemicals for chronic toxicity tests on the copepod. As the endpoints in the chronic toxicity test, survival, sex ratio, developmental time and fecundity of the copepod were used. All chemicals used in this study resulted in increased toxicity in the F1 generation. The lowest-observed-adverse-effect (LOAE) concentrations of WAF, CEWAF-H, CEWAF-C, Hiclean and Corexit 9500 were observed to be 50%, 10%, 0.1%, 1% and 1%, respectively. The results in present study imply that copepods in marine may be negatively influenced by spilled oil and dispersant.
Assuntos
Copépodes/efeitos dos fármacos , Petróleo/análise , Poluentes Químicos da Água/toxicidade , Animais , Cromatografia Gasosa , Copépodes/crescimento & desenvolvimento , Dose Letal Mediana , Lipídeos/química , Lipídeos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Razão de Masculinidade , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Poluentes Químicos da Água/químicaRESUMO
Methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (salsolinol), an endogenous neurotoxin, is known to perform a role in the pathogenesis of Parkinson's disease (PD). In this study, we evaluated oxidative modification of cytochrome c occurring after incubation with salsolinol. When cytochrome c was incubated with salsolinol, protein aggregation increased in a dosedependent manner. The formation of carbonyl compounds and the release of iron were obtained in salsolinol- treated cytochrome c. Salsolinol also led to the release of iron from cytochrome c. Reactive oxygen species (ROS) scavengers and iron specific chelator inhibited the salsolinol-mediated cytochrome c modification and carbonyl compound formation. It is suggested that oxidative damage of cytochrome c by salsolinol might induce the increase of iron content in cells, subsequently leading to the deleterious condition which was observed. This mechanism may, in part, provide an explanation for the deterioration of organs under neurodegenerative disorders such as PD.
Assuntos
Citocromos c/metabolismo , Isoquinolinas/toxicidade , Neurotoxinas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Cobre/química , Dano ao DNA/efeitos dos fármacos , Ferro/química , Carbonilação Proteica/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Tapia syndrome is a rare entity characterized by unilateral paralysis of the tongue and vocal cord caused by X(th) and XII(th) cranial nerve lesions. However, there has been no report of Tapia syndrome immediately following spine surgery. A 47-year-old man underwent posterior decompressive laminectomy for cervical stenosis. The surgery took about 117 minutes and it was uneventful. Postoperatively he developed hoarseness of voice during speech, with deviation of tongue protrusion. On laryngoscopic examination, paralysis of the left side of the tongue and the soft palate was found and complete palsy of the left vocal cord was noted. After excluding surgical cause and craniocervical lesion, a clinical diagnosis of Tapia syndrome was made. Here we report a rare case of Tapia syndrome developed after posterior approach for cervical spine surgery and discuss the possible mechanisms of this uncommon syndrome.
RESUMO
So far, there have been few previous reports of tuberculous spondylitis occurring after percutaneous vertebroplasty. We report an unusual case of tuberculous spondylitis diagnosed after percutaneous vertebroplasty in a patient who had a history of pulmonary tuberculosis for the first time. A 58-year-old woman, who had a history of complete recovery from pulmonary tuberculosis six years previously, was hospitalized due to severe back pain after a fall. Radiological studies revealed a fresh compression fracture at the T12 thoracic vertebra. The back pain improved dramatically, and the patient was discharged two days after the vertebroplasty. However, cold sweats and a low grade fever with severe back pain developed four weeks after the procedure. Magnetic resonance imaging revealed a severe kyphosis and the T11-T12 disc space had collapsed with heterogeneous signal intensity. The results of the culture of the biopsy specimens were negative, and did not lead to identification of the causative micro-organism. However, the polymerase chain reaction for Mycobacterium tuberculosis was positive. Treatment for tuberculous spondylitis was started and she underwent posterior fusion and instrumentation from T9-L2 after the markers for infection returned to normal. After surgical intervention, the pain improved and the kyphotic deformity was corrected.
RESUMO
PURPOSE: Combined chemoradiotherapy is standard management for locally advanced non-small cell lung cancer (LA-NSCLC), but standard treatment for elderly patients with LA-NSCLC has not been confirmed yet. We evaluated the feasibility and efficacy of concurrent chemoradiotherapy (CCRT) for elderly patients with LA-NSCLC. MATERIALS AND METHODS: Among patients older than 65 years with LA-NSCLC, 36 patients, who underwent CCRT were retrospectively analyzed. Chemotherapy was administered 3-5 times with 4 weeks interval during radiotherapy. Thoracic radiotherapy was delivered to the primary mass and regional lymph nodes. Total dose of 54-59.4 Gy (median, 59.4 Gy) in daily 1.8 Gy fractions and 5 fractions per week. RESULTS: Regarding the response to treatment, complete response, partial response, and no response were shown in 16.7%, 66.7%, and 13.9%, respectively. The 1- and 2-year overall survival (OS) rates were 58.2% and 31.2%, respectively, and the median survival was 15 months. The 1- and 2-year progression-free survivals (PFS) were 41.2% and 19.5%, respectively, and the median PFS was 10 months. Regarding to the toxicity developed after CCRT, pneumonitis and esophagitis with grade 3 or higher were observed in 13.9% (5 patients) and 11.1% (4 patients), respectively. Treatment-related death was not observed. CONCLUSION: The treatment-related toxicity as esophagitis and pneumonitis were noticeably lower when was compared with the previously reported results, and the survival rate was higher than radiotherapy alone. The results indicate that CCRT is an effective in terms of survival and treatment related toxicity for elderly patients over 65 years old with LA-NSCLC.
RESUMO
To assess the effects of crude oil and dispersant on marine planktonic ecosystems, analyses were performed in 1000-L mesocosm over a period of nine days. Triplicate experiments were conducted for two different treatments, namely, addition of crude oil alone and oil plus dispersant. In the mesocosm with oil plus dispersant, high concentrations of total petroleum hydrocarbon (TPH) were soon found in the bottom layer. In addition, most planktonic communities responded drastically to the presence of dispersant acting to disperse TPH: total bacterial abundances increased for the first two days and then decreased rapidly for the remainder of the experiment. The abundance of heterotrophic flagellates increased rapidly in association with the increase in bacterial cells. The abundance of phytoplankton and zooplankton communities decreased clearly within two days. Time-delayed relationship also revealed that the TPH concentration had a significant negative relationship with phyto- and zooplankton communities within two days. However, most planktonic communities were affected less adversely in the mesocosms treated with crude oil alone than in those treated with both crude oil and dispersant. The present results demonstrate that the planktonic ecosystem was damaged more severely by the introduction of dispersant than by the harmful effects of crude oil itself. Therefore, caution should be taken when considering the direct application of dispersant in natural environments, even though it has the advantage of rapidly removing crude oil.
Assuntos
Biologia Marinha , Petróleo/toxicidade , Plâncton/efeitos dos fármacosRESUMO
Methylglyoxal (MG) was identified as an intermediate in non-enzymatic glycation and increased levels were reported in patients with diabetes. In this study, we evaluated the effects of MG on the modification of ferritin. When ferritin was incubated with MG, covalent crosslinking of the protein increased in a time- and MG dose-dependent manner. Reactive oxygen species (ROS) scavengers, N-acetyl-(L)-cysteine and thiourea suppressed the MG-mediated ferritin modification. The formation of dityrosine was observed in MG-mediated ferritin aggregates and ROS scavengers inhibited the formation of dityrosine. During the reaction between ferritin and MG, the generation of ROS was increased as a function of incubation time. These results suggest that ROS may play a role in the modification of ferritin by MG. The reaction between ferritin and MG led to the release of iron ions from the protein. Ferritin exposure to MG resulted in a loss of arginine, histidine and lysine residues. It was assumed that oxidative damage to ferritin caused by MG may induce an increase in the iron content in cells, which is deleterious to cells. This mechanism, in part, may provide an explanation or the deterioration of organs under diabetic conditions.
Assuntos
Ferritinas/metabolismo , Aldeído Pirúvico/farmacologia , Relação Dose-Resposta a Droga , Sequestradores de Radicais Livres/metabolismo , Oxirredução/efeitos dos fármacos , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo , Tirosina/análogos & derivados , Tirosina/biossínteseRESUMO
The protein association of estrogen receptor α ERα with DNA-bound SP1 and C/EBPß is essential for the 17ß-estradiol (E2)-induced activation of human prolactin receptor (hPRLR) gene transcription. Protein-protein interaction and complex formation at the hPIII promoter of hPRLR was investigated. The basic region and leucine zipper (bZIP) of C/EBPß, zinc finger (ZF) motifs of SP1, and the DNA binding domain of ERα were identified as regions responsible for the interactions between transfactors. The E2-induced interaction was confirmed by bioluminescence resonance energy transfer (BRET) assays of live cells. The combination of BRET/bimolecular luminescence complementation assay revealed that ERα exists as a constitutive homodimer, and E2 induced a change(s) in ERα homodimer conformation favorable for its association with C/EBPß and SP1. Chromatin immunoprecipitation and small interfering RNA knockdown of members of the complex in breast cancer cells demonstrated the endogenous recruitment of components of the complex onto the hPIII promoter of the hPRLR gene. SP1 is the preferred transfactor for the recruitment of ERα to the complex that facilitates the C/EBPß association. The E2/ERα-induced hPRLR transcription was demonstrated in ERα-negative breast cancer cells. This study indicates that the enhanced complex formation of ERα dimer with SP1 and C/EBPß by E2 has an essential role in the transcriptional activation of the hPRLR gene.
Assuntos
Complexos Multiproteicos/biossíntese , Receptores da Prolactina/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica , Sítios de Ligação , Neoplasias da Mama/patologia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Linhagem Celular Tumoral , Estradiol/metabolismo , Estradiol/farmacologia , Feminino , Humanos , Regiões Promotoras Genéticas , Multimerização Proteica , Fator de Transcrição Sp1/metabolismo , Ativação TranscricionalRESUMO
Excess free iron generates oxidative stress that may contribute to the pathogenesis of various causes of neurodegenerative diseases. In this study, we assessed the modification of ferritin induced by H(2)O(2). When ferritin was incubated with H(2)O(2), the degradation of ferritin L-chain increased with the H(2)O(2) concentration whereas ferritin H-chain was remained. Free radical scavengers, azide, thiourea, and N-acetyl-(L)-cysteine suppressed the H(2)O(2)-mediated ferritin modification. The iron specific chelator, deferoxamine, effectively prevented H(2)O(2)-mediated ferritin degradation in modified ferritin. The release of iron ions from ferritin was increased in H(2)O(2) concentration-dependent manner. The present results suggest that free radicals may play a role in the modification and iron releasing of ferritin by H(2)O(2). It is assumed that oxidative damage of ferritin by H(2)O(2) may induce the increase of iron content in cells and subsequently lead to the deleterious condition.
Assuntos
Ferritinas/metabolismo , Peróxido de Hidrogênio/metabolismo , Oxidantes/metabolismo , Animais , Ferritinas/química , Sequestradores de Radicais Livres/metabolismo , Radicais Livres/metabolismo , Cavalos , Ferro/metabolismo , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Vitamin C (VC) is an important antioxidant and enzyme co-factor that works by stimulating the immune system and protecting against infections. It is well known that melanoma cells are more susceptible to VC than any other tumor cells. However, the role of VC in the treatment of colon cancer has not been studied. Cisplatin (CDDP) is a DNA damaging agent and is widely used for treating cancer, while the role of p53 in CDDP-induced cell death has been stressed. Using cell growth assays, morphological methods, Western blotting, flow cytometry, and DNA fragmentation analysis, we measured the expression of p53 level involved in the effect of VC on CDDP-induced apoptosis of HCT116, a human colon cancer cell line. CDDP plus VC treatment resulted in significantly increased apoptosis along with upregulation of p53 compared to untreated cells and/or CDDP-treated cells. These results suggest that VC enhanced CDDP sensitivity and apoptosis via upregulation of p53.
Assuntos
Apoptose/efeitos dos fármacos , Ácido Ascórbico/farmacologia , Linhagem Celular Tumoral/efeitos dos fármacos , Cisplatino/farmacologia , Genes p53/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Animais , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral/fisiologia , Fragmentação do DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Proteína Supressora de Tumor p53/genética , Regulação para Cima/efeitos dos fármacosRESUMO
The LHR has an essential role in sexual development and reproductive function, and its transcription is subjected to several modes of regulation. In this study, we investigated PC4 coactivator function in the control of LHR transcription. Knockdown of PC4 by siRNA inhibited the LHR basal promoter activity and trichostatin A (TSA)-induced gene transcriptional activation and expression in MCF-7 cells. While overexpression of PC4 alone had no effect on the LHR gene, it significantly enhanced Sp1- but not Sp3-mediated LHR transcriptional activity. PC4 directly interacts with Sp1 at the LHR promoter, and this interaction is negatively regulated by PC4 phosphorylation. The coactivator domain (22-91 aa) of PC4 and DNA binding domain of Sp1 are essential for PC4/Sp1 interaction. ChIP assay revealed significant occupancy of PC4 at the LHR promoter that increased upon TSA treatment. Disruption of PC4 expression significantly reduced TSA-induced recruitment of TFIIB and RNAP II, at the promoter. PC4 functions are beyond TSA-induced phosphatase release, PI3K-mediated Sp1 phosphorylation, and HDAC1/2/mSin3A co-repressor release indicating its role as linker coactivator of Sp1 and the transcriptional machinery. These findings demonstrated a critical aspect of LHR modulation whereby PC4 acts as a coactivator of Sp1 to contribute to the human of LHR transcription.