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Over the past decade, significant progress has been made in the direct C-H acylation of naphthalenes, occurring at the α or ß-positions to yield valuable ketones through Friedel-Crafts acylation or transition-metal-catalysed carbonylative coupling reactions. Nevertheless, highly regioselective acylation of naphthalenes remains a formidable challenge. Herein, we developed a nickel-catalysed reductive ring-opening reaction of 7-oxabenzonorbornadienes with acyl chlorides as the electrophilic coupling partner, providing a new method for the exclusive preparation of ß-acyl naphthalenes.
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Parkinson's disease (PD) is a ubiquitous brain cell degeneration disease and presents a significant therapeutic challenge. By injecting 6-hydroxydopamine (6-OHDA) into the left medial forebrain bundle, rats were made to exhibit PD-like symptoms and treated by intranasal administration of a low-dose (2 × 105) or high-dose (1 × 106) human neural stem cells (hNSCs). Apomorphine-induced rotation test, stepping test, and open field test were implemented to evaluate the motor behavior and high-performance liquid chromatography was carried out to detect dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin, and 5-hydroxyindole-3-acetic acid in the striatum of rats. Animals injected with 6-OHDA showed significant motor function deficits and damaged dopaminergic system compared to the control group, which can be restored by hNSCs treatment. Treatment with hNSCs significantly increased the tyrosine hydroxylase-immunoreactive cell count in the substantia nigra of PD animals. Moreover, the levels of neurotransmitters exhibited a significant decline in the striatum tissue of animals injected with 6-OHDA when compared to that of the control group. However, transplantation of hNSCs significantly elevated the concentration of DA and DOPAC in the injured side of the striatum. Our study offered experimental evidence to support prospects of hNSCs for clinical application as a cell-based therapy for PD.
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OBJECTIVE: To determine the maximum tolerated dose (MTD) of paclitaxel combined with a fixed dose of cisplatin (75 mg/m2) delivered via hyperthermic intraperitoneal chemotherapy (HIPEC) to patients with ovarian cancer. METHODS: This multicenter Phase I trial employed a Bayesian Optimal Interval (BOIN) design. The MTD was determined to have a target dose-limiting toxicity (DLT) rate of 25%. The starting dose was 175 mg/m2. The Data and Safety Monitoring Board made decisions regarding dose escalation or de-escalation in increments of 25 mg/m2 for subsequent patient cohorts, up to a maximum sample size of 30 or 12 patients treated at a given dose. RESULTS: Twenty-one patients participated in this study. Among the three evaluable patients who received 150 mg/m2 paclitaxel, no DLTs were observed. Among the 12 evaluable patients who received 175 mg/m2 paclitaxel, two reported DLTs: one had grade 4 neutropenia and one had grade 4 anemia, neutropenia, and leukopenia. Four of the six evaluable patients who received 200 mg/m2 paclitaxel reported DLTs: one patient had grade 4 diarrhea, one had grade 3 kidney injury, and two had grade 4 anemia. The isotonic estimate of the DLT rate in the 175 mg/m2 dose group was 0.17 (95% confidence interval, 0.02-0.42), and this dose was selected as the MTD. CONCLUSION: Paclitaxel, when combined with a fixed dose of cisplatin (75 mg/m2), can be safely administered intraperitoneally at a dose of 175 mg/m2 in patients with ovarian cancer who received HIPEC (43 °C, 90 min) following cytoreductive surgery.
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Anemia , Neutropenia , Neoplasias Ovarianas , Humanos , Feminino , Cisplatino , Paclitaxel , Quimioterapia Intraperitoneal Hipertérmica , Dose Máxima Tolerável , Teorema de Bayes , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ovarianas/terapia , Neutropenia/induzido quimicamente , Anemia/etiologia , Relação Dose-Resposta a DrogaRESUMO
We describe three cases of overlapping Epstein-Barr virus (EBV) Encephalitis and Autoimmune Glial Fibrillary Acidic Protein Astrocytopathy (GFAP-A). The three cases all presented with initial symptoms of fever, headache, coma, and posture tremor of the upper limbs, then followed by limb weakness and dysuria. All of the three cases were on ventilators. Case 1 and 2 improved dramatically after intravenous methylprednisoloneand immunoglobulin treatment. However, case 3 presented dyspneic, and died from gastrointestinal hemorrhage. The GFAP-A triggered by EBV intracranial infection could initially masquerade as EBV encephalitis only, and the detection of GFAP antibody is essential for differentiation.
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Astrócitos , Doenças Autoimunes do Sistema Nervoso , Encefalite , Infecções por Vírus Epstein-Barr , Proteína Glial Fibrilar Ácida , Humanos , Anticorpos , Astrócitos/imunologia , Astrócitos/metabolismo , Autoanticorpos , Encefalite/complicações , Encefalite/imunologia , Encefalite/terapia , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/terapia , Proteína Glial Fibrilar Ácida/genética , Proteína Glial Fibrilar Ácida/imunologia , Herpesvirus Humano 4 , Imunoglobulinas Intravenosas , Metilprednisolona/uso terapêutico , Glucocorticoides/uso terapêutico , Doenças Autoimunes do Sistema Nervoso/complicações , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Doenças Autoimunes do Sistema Nervoso/terapia , Diagnóstico DiferencialRESUMO
Inflammation is one of the pathogenic processes in Parkinson's disease (PD). Dopamine receptor agonist pramipexole (PPX) is extensively used for PD treatment in clinics. A number of studies show that PPX exerts neuroprotection on dopaminergic (DA) neurons, but the molecular mechanisms underlying the protective effects of PPX on DA neurons are not fully elucidated. In the present study, we investigated whether PPX modulated PD-related neuroinflammation and underlying mechanisms. PD model was established in mice by bilateral striatum injection of lipopolyssaccharide (LPS). The mice were administered PPX (0.5 mg·kg-1·d-1, i.p.) 3 days before LPS injection, and for 3 or 21 days after surgery, respectively, for biochemical and histological analyses. We showed that PPX administration significantly alleviated the loss of DA neurons, and suppressed the astrocyte activation and levels of proinflammatory cytokine IL-1ß in the substantia nigra of LPS-injected mice. Furthermore, PPX administration significantly decreased the expression of NLRP3 inflammasome-associated proteins, i.e., cleaved forms of caspase-1, IL-1ß, and apoptosis-associated speck-like protein containing a caspase recruit domain (ASC) in the striatum. These results were validated in LPS+ATP-stimulated primary mouse astrocytes in vitro. Remarkably, we showed that PPX (100-400 µM) dose-dependently enhanced the autophagy activity in the astrocytes evidenced by the elevations in LC3-II and BECN1 protein expression, as well as the increase of GFP-LC3 puncta formation. The opposite effects of PPX on astrocytic NLRP3 inflammasome and autophagy were eliminated by Drd3 depletion. Moreover, we demonstrated that both pretreatment of astrocytes with autophagy inhibitor chloroquine (40 µM) in vitro and astrocyte-specific Atg5 knockdown in vivo blocked PPX-caused inhibition on NLRP3 inflammasome and protection against DA neuron damage. Altogether, this study demonstrates an anti-neuroinflammatory activity of PPX via a Drd3-dependent enhancement of autophagy activity in astrocytes, and reveals a new mechanism for the beneficial effect of PPX in PD therapy.
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Doença de Parkinson , Camundongos , Animais , Pramipexol/uso terapêutico , Pramipexol/metabolismo , Pramipexol/farmacologia , Doença de Parkinson/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Inflamassomos/metabolismo , Astrócitos/metabolismo , Lipopolissacarídeos/farmacologia , Autofagia , Camundongos Endogâmicos C57BLRESUMO
TRPM (transient receptor potential melastatin) 7, a member of the TRPM subfamily, is a nonselective cation channel located on the cell membrane that regulates mammalian cell intracellular Mg2+ balance. TRPM7 is widely expressed in vivo and is characterized by a unique domain structure comprised of cation channel and protein kinase. TRPM7 primarily controls the cellular influx of Mg2+ and Ca2+. As such TRPM7 plays an important role in the physiological processes of cell proliferation, adhesion, migration, and differentiation, as well as phenotypic transformation. Changes in TRPM7 expression and activity are directly related to diseases such as tissue fibrosis, vascular injury, as well as the occurrence and development of tumors. The structure and function of TRPM7 has been previously described, but regulation of TRPM7 has been limited to Mg2+ and laboratory pharmacological compounds. Hence, in this review, we summarized the endogenous and exogenous regulation of TRPM7, clarified its internal regulatory mechanisms and molecular signaling pathways, and emphasized the regulation of TRPM7 activity as an important target for disease treatment.
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Neoplasias , Canais de Cátion TRPM , Animais , Proliferação de Células , Mamíferos/metabolismo , Neoplasias/patologia , Proteínas Quinases/metabolismo , Transdução de Sinais/fisiologia , Canais de Cátion TRPM/metabolismoRESUMO
Induced pluripotent stem cells (iPSCs) offer an unprecedented opportunity to mimic human diseases of related cell types, but it is unclear whether they can successfully mimic age-related diseases such as Parkinson's disease (PD). We generated iPSCs lines from three patients with familial PD associated with the G2019S mutation in the LRRK2 gene and one age-matched healthy individual (control). During long-term culture, dopaminergic (DA) neurons differentiated from iPSCs of G2019S LRRK2 PD patients exhibited morphological changes, including a reduced number of neurites and neurite arborization, which were not evident in DA neurons differentiated from control iPSCs. To mimic PD pathology in vitro, we used 1-methyl-4-phenylpyridium (MPP+) to damage DA neurons and found that DA neurons differentiated from patients with G2019S LRRK2 mutation significantly reduced the survival rate and increased apoptosis compared with the controls. We also found that the mRNA level of inflammatory factors [interleukin (IL)-1ß, tumor necrosis factor-α, cyclooxygenase-2, IL-6, and inducible NO synthase] with G2019S LRRK2 mutation were higher than control group after exposure to MPP+. Our study provides an in vitro model based on iPSCs that captures the patients' genetic complexity and investigates the pathogenesis of familial PD cases in a disease-associated cell type.
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Microglial activation and neuroinflammation induced by amyloid ß (Aß) play pivotal roles in Alzheimer's disease (AD) pathogenesis. Astragaloside IV (AS-IV) is one of the major active compounds of the traditional Chinese medicine Astmgali Radix. It has been reported that AS-IV could protect against Aß-induced neuroinflammation and cognitive impairment, but the underlying mechanisms need to be further clarified. In this study, the therapeutic effects of AS-IV were investigated in an oligomeric Aß (oAß) induced AD mice model. The effects of AS-IV on microglial activation, neuronal damage and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase expression were further studied. Different doses of AS-IV were administered intragastrically once a day after intracerebroventricularly oAß injection. Results of behavioral experiments including novel object recognition (NOR) test and Morris water maze (MWM) test revealed that AS-IV administration could significantly ameliorate oAß-induced cognitive impairment in a dose dependent manner. Enzyme linked immunosorbent assay (ELISA) results showed that increased levels of reactive oxygen species (ROS), tumor necrosis factor α (TNF-α), interleukin-1ß (IL-1ß) and IL-6 in hippocampal tissues induced by oAß injection were remarkably inhibited after AS-IV treatment. OAß induced microglial activation and neuronal damage was significantly suppressed in AS-IV-treated mice brain, observed in immunohistochemistry results. Furthermore, oAß upregulated protein expression of NADPH oxidase subunits gp91phox, p47phox, p22phox and p67phox were remarkably reduced by AS-IV in Western blotting assay. These results revealed that AS-IV could ameliorate oAß-induced cognitive impairment, neuroinflammation and neuronal damage, which were possibly mediated by inhibition of microglial activation and down-regulation of NADPH oxidase protein expression. Our findings provide new insights of AS-IV for the treatment of neuroinflammation related diseases such as AD.
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Doença de Alzheimer , Astrágalo/química , Disfunção Cognitiva , Microglia/efeitos dos fármacos , NADPH Oxidases/metabolismo , Doenças Neuroinflamatórias , Saponinas/farmacologia , Triterpenos/farmacologia , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/efeitos adversos , Animais , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto , Camundongos Endogâmicos ICR , NADP , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/metabolismo , Neurônios , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Fitoterapia , Espécies Reativas de Oxigênio/metabolismo , Saponinas/uso terapêutico , Triterpenos/uso terapêuticoRESUMO
Substantia nigra (SN) hyperechogenicity is present in most Parkinson's disease (PD) cases but is occasionally absent in some. To date, age, gender, disease severity, and other factors have been reported to be associated with SN hyperechogenicity in PD. Previous studies have discovered that excess iron deposition in the SN underlies its hyperechogenicity in PD, which may also indicate the involvement of genes associated with iron metabolism in hyperechogenicity. The objective of our study is to explore the potential associations between variants in iron metabolism-associated genes and SN echogenicity in Han Chinese PD. Demographic profiles, clinical data, SN echogenicity and genotypes were obtained from 221 Han Chinese PD individuals with a sufficient bone window. Serum ferritin levels were quantified in 92 of these individuals by immunochemical assay. We then compared factors between PD individuals with SN hyperechogenicity and those with SN hypoechogenicity to identify factors that predispose to SN hyperechogenicity. Of our 221 participants, 122 (55.2%) displayed SN hyperechogenicity, and 99 (44.8%) displayed SN hypoechogenicity. Gender and serum ferritin levels were found to be associated with SN hyperechogenicity. In total, 14 genes were included in the sequencing part. After data processing, 34 common single nucleotide polymorphisms were included in our further analyses. In our data, we also found a significantly higher frequency of PANK2 rs3737084 (genotype: OR = 2.07, P = 0.013; allele: OR = 2.51, P = 0.002) in the SN hyperechogenic group and a higher frequency of PLA2G6 rs731821 (genotype: OR = 0.45, P = 0.016; allele: OR = 0.44, P = 0.011) in the SN hypoechogenic group. However, neither of the two variants was found to be correlated with serum ferritin. This study demonstrated that genetic factors, serum ferritin level, and gender may explain the interindividual variability in SN echogenicity in PD. This is an explorative study, and further replication is warranted in larger samples and different populations.
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Ferritinas/sangue , Ferro/metabolismo , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/genética , Substância Negra/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico , Polimorfismo de Nucleotídeo Único/genética , Fatores SexuaisRESUMO
BACKGROUND: Parkinson's disease (PD) is one of the neurodegeneration diseases characterized by the gradual loss of dopaminergic (DA) neurons in the substantia nigra region of the brain. Substantial evidence indicates that at the cellular level mitochondrial dysfunction is a key factor leading to pathological features such as neuronal death and accumulation of misfolded α-synuclein aggregations. Autologous transplantation of healthy purified mitochondria has shown to attenuate phenotypes in vitro and in vivo models of PD. However, there are significant technical difficulties in obtaining large amounts of purified mitochondria with normal function. In addition, the half-life of mitochondria varies between days to a few weeks. Thus, identifying a continuous source of healthy mitochondria via intercellular mitochondrial transfer is an attractive option for therapeutic purposes. In this study, we asked whether iPSCs derived astrocytes can serve as a donor to provide functional mitochondria and rescue injured DA neurons after rotenone exposure in an in vitro model of PD. METHODS: We generated DA neurons and astrocytes from human iPSCs and hESCs. We established an astroglial-neuronal co-culture system to investigate the intercellular mitochondrial transfer, as well as the neuroprotective effect of mitochondrial transfer. We employed immunocytochemistry and FACS analysis to track mitochondria. RESULTS: We showed evidence that iPSCs-derived astrocytes or astrocytic conditioned media (ACM) can rescue DA neurons degeneration via intercellular mitochondrial transfer in a rotenone induced in vitro PD model. Specifically, we showed that iPSCs-derived astrocytes from health spontaneously release functional mitochondria into the media. Mito-Tracker Green tagged astrocytic mitochondria were detected in the ACM and were shown to be internalized by the injured neurons via a phospho-p38 depended pathway. Transferred mitochondria were able to significantly reverse DA neurodegeneration and axonal pruning following exposure to rotenone. When rotenone injured neurons were cultured in presence of ACM depleted of mitochondria (by ultrafiltration), the neuroprotective effects were abolished. CONCLUSIONS: Our studies provide the proof of principle that iPSCs-derived astrocytes can act as mitochondria donor to the injured DA neurons and attenuate pathology. Using iPSCs derived astrocytes as a donor can provide a novel strategy that can be further developed for cellular therapy for PD.
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Astrócitos/fisiologia , Neurônios Dopaminérgicos/fisiologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Inseticidas/toxicidade , Mitocôndrias/fisiologia , Rotenona/toxicidade , Astrócitos/efeitos dos fármacos , Sobrevivência Celular , Técnicas de Cocultura , Neurônios Dopaminérgicos/efeitos dos fármacos , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/fisiologia , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacosRESUMO
The number of Parkinson's disease (PD) patients increases with aging, which brings heavy burden to families and society. The emergence of patient-derived induced pluripotent stem cells (iPSCs) has brought hope to the current situation of lacking new breakthroughs in diagnosis and treatment of PD. In this article, we reviewed and analyzed the current researches related to PD patient-derived iPSCs, in order to provide solid theoretical basis for future study of PD. In 2008, successful iPSCs derived from PD patients were reported. The current iPSCs research in PD mostly focused on the establishment of specific iPSCs models of PD patients carrying susceptible genes. The main source of PD patient-derived iPSCs is skin fibroblasts and the mainstream reprogramming methodology is the mature "four-factor" method, which introduces four totipotent correlation factors Oct4, Sox2, Klf4 and c-Myc into somatic cells. The main sources of iPSCs are patients with non-pedigrees and there have been no studies involving both PD patients and unaffected carriers within the same family. Most of the existing studies of PD patient-derived iPSCs started with the induction method for obtaining dopaminergic neurons in the first instance, but therapeutic applications are being increased. Although it is not the ultimate panacea, and there are still some unsolved problems (e.g., whether the mutated genes should be corrected or not), a better understanding of iPSCs may be a good gift for both PD patients and doctors due to their advantages in diagnosis and treatment of PD.
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BACKGROUND AND PURPOSE: Telangiectatic osteosarcoma (TOS), a rare variant of osteosarcoma, may be easily misdiagnosed as aneurysmal bone cyst (ABC). The aims of this study were to investigate the diagnostic and prognostic factors of TOS by reviewing our experience with TOS and to develop a diagnostic model that may distinguish TOS from ABC. MATERIALS AND METHODS: We identified 51 cases of TOS treated at the First Affiliated Hospital of Sun Yat-Sen University from March 2001 to January 2016 and reviewed their records, imaging information and pathological studies. A diagnostic model was developed to differentiate TOS and ABC by Bayes discriminant analysis and was evaluated. The log-rank test was used to analyze the prognostic factors of TOS and to compare the outcome differences between TOS and other high-grade osteosarcoma subtypes. RESULTS: The multi-disciplinary diagnostic method employed that combined clinical, imaging, and pathological studies enhanced the diagnostic accuracy. Age 18 years or younger and pathologic fracture were more common among the TOS patients than among the ABC patients (P = .004 and .005, respectively). The average white blood cell (WBC), platelet, lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) values of the TOS patients were higher than those of the ABC patients (P = .002, .003, .007, and .007, respectively). Our diagnostic model, including the aforementioned factors, accurately predicted 62% and 78% of the TOS patients in the training and validation sets, respectively. The 5-year estimates of event-free survival and overall survival of the TOS patients were 52.5 ± 9.4% and 54.9 ± 8.8%, respectively, which were similar to those of patients with other osteosarcoma subtypes (P = .950 and .615, respectively). Tumor volume and the LDH level were predictive prognostic factors (P = .040 and .044) but not the presence of pathologic fracture or misdiagnosis (P = .424 and .632, all respectively). CONCLUSIONS: The multi-disciplinary diagnostic method and diagnostic model based on predictive factors, i.e., age, the presence of pathologic fracture, and platelet, LDH, ALP and WBC levels, aided the differentiation of TOS and ABC. Smaller tumors and normal LDH levels were associated with better outcomes.
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Alcoholic liver disease (ALD) is a global liver disease which characterized by liver inflammation, fatty liver, alcoholic hepatitis, or liver cirrhosis. Alcohol abuse is one of the main reasons for liver disease. Alcoholic fatty liver (AFL) disease is the early stage of ALD and associated with the excessive lipids accumulation in hepatocytes as well as oxidative stress. MicroRNA-203 (miR-203) is known to suppress the proliferation and metastasis of hepatocellular carcinoma, but the role in the progression of alcoholic liver disease is not clear and is warranted for further investigation. In the present study, we have found the expression of miR-203 is down-regulated in Gao-Binge alcoholic mice model and ethanol-induced AML-12 cell lines in vitro. Furthermore, over-expression of miR-203 decrease the lipids accumulation in liver and ethanol-induced AML-12 cells. Mechanistically, we identified that Lipin1 is a key regulator of hepatic lipid metabolism, and acts as a downstream target for miR-203. In summary, our results suggested that over-expression of miR-203 inhibited the liver lipids accumulation and the progression of AFL by targeting Lipin1.
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Bombyx mori is an economic insect of the Lepidoptera. Its posterior silk gland (PSG) is an important organ for fibroin synthesis. In order to study the occurrence of apoptosis in PSG and the role of PI3K/Akt signaling pathway during spinning period, changes in morphology of silk gland, expressions of fibroin components Fib-H, Fib-L and P25 and Akt, TOR2, P70S6K and S6 in PI3K/Akt pathway, expressions of apoptosis related genes caspase-3, caspase-9 and activity of caspase-3 were explored. The results showed that the morphology of silk gland dramatically degenerated; transcription of Fib-H, Fib-L, and P25 gradually declined with time; and Fib-L protein level reduced by 0.6-fold at 72 h. Moreover, the transcription levels of Akt, TOR2, P70S6K, and S6 also decreased by 0.3-, 0.8-, 0.7-, and 0.1-fold, respectively, indicating that the downregulation of PI3K/Akt signaling pathway could lead to reduction in fibroin synthesis. In addition, the transcription levels of caspase-3 and caspase-9 increased by 1.3- and 3.6-fold, respectively, and the enzyme activity of caspase-3 grew at a maximum of 1.6-fold. The results showed the occurrence of apoptosis in PSG during spinning period. In conclusion, the present study indicated that both the decline in fibroin components and the increase in apoptosis-related genes were regulated by PI3K/Akt signaling pathway during spinning period, which shed new light on the functions of PI3K/Akt signaling pathway.
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Apoptose/fisiologia , Bombyx/metabolismo , Animais , Bombyx/crescimento & desenvolvimento , Caspase 3/genética , Caspase 3/metabolismo , Caspase 9/genética , Caspase 9/metabolismo , Fibroínas/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Larva/crescimento & desenvolvimento , Larva/metabolismo , Metamorfose Biológica , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Seda/biossínteseRESUMO
Serum response factor (SRF), a transcription factor highly expressed in neurons, is involved in neuronal survival and the pathogenesis of some neurodegenerative disorders. The ablation of SRF renders the midbrain dopaminergic (DA) neurons vulnerable to 1-methyl 4-phenyl 1,2,3,6-tetrahydropyridine-induced neurotoxicity, however, the underlying mechanisms remain poorly understood. Here, we report decreased SRF levels in the substantia nigra (SN) of rotenone-treated rats that was associated with the loss of tyrosine hydroxylase (TH)-positive neurons. SRF expression was also reduced in rotenone-treated PC12 cells in vitro. In addition, Srf knockdown augmented rotenone-induced toxicity in PC12 cells. In contrast, overexpression of Srf attenuated the cells' sensitivity to rotenone and alleviated rotenone-induced α-synuclein accumulation. The protective effect of SRF was abolished when the expression of autophagy-related proteins Beclin 1 and Atg5 was suppressed. These results suggested that SRF may promote DA neuron survival by regulating autophagy, and thus serves as a critical molecule in PD progression.
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Autofagia/fisiologia , Proteína Beclina-1/metabolismo , Neurônios Dopaminérgicos/metabolismo , Transtornos Parkinsonianos/metabolismo , Substância Negra/metabolismo , Fatores de Transcrição/metabolismo , Animais , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Proteína Beclina-1/genética , Sobrevivência Celular/fisiologia , Neurônios Dopaminérgicos/patologia , Masculino , Células PC12 , Transtornos Parkinsonianos/patologia , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Rotenona , Substância Negra/patologia , Tirosina 3-Mono-Oxigenase/metabolismo , alfa-Sinucleína/metabolismoRESUMO
Esophageal squamous cell carcinoma (ESCC) is among the most common malignancies, with a low 5-year overall survival rate. In previous studies, we and others have found that 9p21.3 was the most frequently deleted region in ESCC. The MTAP gene, which is located close to CDKN2A/B in 9p21.3, encodes methylthioadenosine phosphorylase. This enzyme plays an important role during the process of adenosine transfer. In the present study, we found that MTAP is deleted at the genomic level in 19.1% (64/341) of primary ESCC tumors, and decreased mRNA and protein expression were present in 31.1% (28/90) and 33.3% (6/18) of ESCCs, respectively. Further statistical analysis showed a positive correlation between deletion and decreased mRNA expression of MTAP in the ESCC tissues tested (coefficient: 0.826; P=1.17×10-23). Knockdown of MTAP expression using small interfering RNA-mediated silencing promoted the invasion and migration of ESCC cells. Also, overexpression of MATP using pcDNA3.1-MTAP plasmid decreased the cell invasion and migration. At the molecular level, MTAP knockdown downregulated E-cadherin and p-GSK3ß but upregulated Slug expression. Our results indicated that MTAP deletion results in the decreased expression in ESCCs and that it plays a role in promoting the mobility and inducing the epithelial-to-mesenchymal transition of ESCC cells via the GSK3ß/Slug/E-cadherin axis. The data suggest that MTAP might function as a tumor suppressor gene in ESCC.
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Current drug therapy fails to reduce lung destruction of chronic obstructive pulmonary disease (COPD). AMP-activated protein kinase (AMPK) has emerged as an important integrator of signals that control energy balance and lipid metabolism. However, there are no studies regarding the role of AMPK in reducing inflammatory responses and cellular senescence during the development of emphysema. Therefore, we hypothesize that AMPK reduces inflammatroy responses, senescence, and lung injury. To test this hypothesis, human bronchial epithelial cells (BEAS-2B) and small airway epithelial cells (SAECs) were treated with cigarette smoke extract (CSE) in the presence of a specific AMPK activator (AICAR, 1 mM) and inhibitor (Compound C, 5 µM). Elastase injection was performed to induce mouse emphysema, and these mice were treated with a specific AMPK activator metformin as well as Compound C. AICAR reduced, whereas Compound C increased CSE-induced increase in IL-8 and IL-6 release and expression of genes involved in cellular senescence. Knockdown of AMPKα1/α2 increased expression of pro-senescent genes (e.g., p16, p21, and p66shc) in BEAS-2B cells. Prophylactic administration of an AMPK activator metformin (50 and 250 mg/kg) reduced while Compound C (4 and 20 mg/kg) aggravated elastase-induced airspace enlargement, inflammatory responses and cellular senescence in mice. This is in agreement with therapeutic effect of metformin (50 mg/kg) on airspace enlargement. Furthermore, metformin prophylactically protected against but Compound C further reduced mitochondrial proteins SOD2 and SIRT3 in emphysematous lungs. In conclusion, AMPK reduces abnormal inflammatory responses and cellular senescence, which implicates as a potential therapeutic target for COPD/emphysema.
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Proteínas Quinases Ativadas por AMP/metabolismo , Senescência Celular , Inflamação/imunologia , Pulmão/metabolismo , Doença Pulmonar Obstrutiva Crônica/imunologia , Enfisema Pulmonar/imunologia , Mucosa Respiratória/metabolismo , Proteínas Quinases Ativadas por AMP/antagonistas & inibidores , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Linhagem Celular , Metabolismo Energético , Feminino , Humanos , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Elastase Pancreática/metabolismo , Pirazóis/farmacologia , Pirimidinas/farmacologia , Ribonucleotídeos/farmacologia , Fumar/efeitos adversosRESUMO
Tumor necrosis factor-α (TNF) is increasingly implicated as a critical pro-inflammatory cytokine involved in chronic inflammation and neurodegeneration of Parkinson's disease (PD). However, the cellular and molecular events that lead to dopaminergic neuron degeneration are not fully understood. In this study, we demonstrated that microglia-released and recombinant TNF disrupted α-synuclein (α-SYN) degradation and caused its accumulation in PC12 cells and midbrain neurons. At subtoxic doses, recombinant TNF was found to increase the number of LC3 puncta dots and LC3II protein level, associated with the increases of P62 protein level. Inhibition of lysosomal degradation with Bafilomycin A1 pretreatment abrogated the TNF-induced elevation in LC3II protein level whereas autophagy inhibitor 3-methyladenine did not affect it. Moreover, TNF led to a marked increase in the number of yellow LC3 dots with a marginal elevation in red-only dots in RFP-GFP-tandem fluorescent LC3 (tf-LC3) transfected PC12 cells, implying the impairment in autophagic flux. Furthermore, TNF treatment reduced lysosomal acidification, as LysoTracker Red fluorescence and LysoSensor fluorescence shift from blue to yellow was markedly decreased in TNF-treated PC12 cells. Co-treatment with mammalian target of rapamycin kinase complex 1 (mTORC1) inhibitor PP242, which activated transcription factor EB (TFEB) signaling and lysosome biogenesis, partially rescued the accumulation of α-SYN in PC12 cells and midbrain neurons. Taken together, our results demonstrated that at subtoxic levels, TNF was able to impair autophagic flux and result in α-SYN accumulation by compromising lysosomal acidification in dopaminergic cells. This may represent a novel mechanism for TNF-induced dopaminergic neuron degeneration in PD.
Assuntos
Autofagia/fisiologia , Neurônios Dopaminérgicos/metabolismo , Lisossomos/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , alfa-Sinucleína/metabolismo , Animais , Autofagia/efeitos dos fármacos , Sobrevivência Celular , Células Cultivadas , Neurônios Dopaminérgicos/efeitos dos fármacos , Embrião de Mamíferos , Feminino , Concentração de Íons de Hidrogênio , Indóis/farmacologia , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Proteína 1 de Membrana Associada ao Lisossomo/metabolismo , Lisossomos/efeitos dos fármacos , Mesencéfalo/citologia , Células PC12 , Gravidez , Purinas/farmacologia , Ratos , Ratos Sprague-Dawley , Sincalida/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , alfa-Sinucleína/genéticaRESUMO
OBJECTIVES: To explore the roles of CD14 and TLR4 in severe hepatitis B induced by endotoxin. METHODS: The levels of mCD14 on PBMCs from 30 cases of severe hepatitis B, 20 cases of chronic hepatitis B and 20 cases of healthy controls were detected by flow cytometry. The expressions of CD14 mRNA and TLR4 mRNA in PBMCs from these patients were also detected by RT-PCR. Meanwhile, the concentration of plasma endotoxin was detected by limulus amebocyte lysate test and the levels of TNF alpha, IL-1, IL-6 in serum were detected by ELISA. RESULTS: The levels of mCD14 on PBMCs in severe hepatitis B, chronic hepatitis B and control were 74.2+/-12.3, 63.6+/-11.8 and 60.3+/-7.2 respectively. There was a significant difference among severe hepatitis B,chronic hepatitis B and healthy controls (both of P less than 0.01). The expressions of CD14 mRNA and TLR4 mRNA (2.92+/-0.67 and 1.86+/-0.45) were also upregulated, compared with that in chronic hepatitis B patients (1.34+/-0.51, 0.93+/-0.18) and healthy group (0.92+/-0.58, 0.73+/-0.16) (P less than 0.01). Similarly, the concentration of plasma endotoxin was much higher in severe hepatitis B (1.87+/-1.61) than that in chronic hepatitis B patients (0.11+/-0.11) and that in healthy group (0.03+/-0.03) (P less than 0.01). As a result, the inflammation cytokines, such as TNF alpha, IL-1 and IL-6 (19.78+/-9.21, 0.96+/-0.16, 68.34+/-48.30) also increased significantly in severe hepatitis B, which were remarkably higher than those in chronic hepatitis B patients (7.26+/-6.52, 0.19+/-0.02 and 19.28+/-4.65) and healthy group (4.15+/-4.06, 0.15+/-0.01 and 12.01+/-3.88) (P less than 0.01). Furthermore, correlation analysis showed there was positive correlation among the level of mCD14, the expression of CD14 mRNA/TLR4 mRNA, the concentration of endotoxin and the levels of inflammation cytokines in severe hepatitis B (r1 = 0.865, r2 = 0.415, r3 = 0.524, all of P less than 0.05). CONCLUSION: Endotoxin is an important factor in the aggravation of hepatitis B. Meanwhile, mCD14, CD14 mRNA and TLR4 mRNA are remarkably upregulated during the endotoxin stimulation. The inflammation cytokines (TNF alpha, IL-1 and IL-6) are also elevated, which may finally result in the aggravation of the hepatitis B. Therefore, CD14, TLR4 and inflammation cytokines play important roles in pathogenesis of severe hepatitis B induced by endotoxin.