RESUMO
CD95 ligand (CD95L) is expressed by immune cells and triggers apoptotic death. Metalloprotease-cleaved CD95L (cl-CD95L) is released into the bloodstream but does not trigger apoptotic signaling. Hence, the pathophysiological role of cl-CD95L remains unclear. We observed that skin-derived endothelial cells from systemic lupus erythematosus (SLE) patients expressed CD95L and that after cleavage, cl-CD95L promoted T helper 17 (Th17) lymphocyte transmigration across the endothelial barrier at the expense of T regulatory cells. T cell migration relied on a direct interaction between the CD95 domain called calcium-inducing domain (CID) and the Src homology 3 domain of phospholipase Cγ1. Th17 cells stimulated with cl-CD95L produced sphingosine-1-phosphate (S1P), which promoted endothelial transmigration by activating the S1P receptor 3. We generated a cell-penetrating CID peptide that prevented Th17 cell transmigration and alleviated clinical symptoms in lupus mice. Therefore, neutralizing the CD95 non-apoptotic signaling pathway could be an attractive therapeutic approach for SLE treatment.
Assuntos
Sinalização do Cálcio , Inflamação/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Fosfolipase C gama/metabolismo , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Receptor fas/metabolismo , Animais , Células Cultivadas , Modelos Animais de Doenças , Feminino , Humanos , Interferon gama/metabolismo , Interleucina-17/metabolismo , Lisofosfolipídeos/metabolismo , Camundongos , Camundongos Endogâmicos MRL lpr , Fragmentos de Peptídeos/administração & dosagem , Fragmentos de Peptídeos/genética , Fosfolipase C gama/genética , Domínios e Motivos de Interação entre Proteínas/genética , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Transcriptoma , Migração Transendotelial e Transepitelial , Receptor fas/genéticaRESUMO
Melanoma is a highly aggressive cancer endowed with a unique capacity of rapidly metastasizing, which is fundamentally driven by aberrant cell motility behaviors. Discovering "migrastatics" targets, specifically controlling invasion and dissemination of melanoma cells during metastasis, is therefore of primary importance. Here, we uncover the prominent expression of the plasma membrane TRPV2 calcium channel as a distinctive feature of melanoma tumors, directly related to melanoma metastatic dissemination. In vitro as well as in vivo, TRPV2 activity is sufficient to confer both migratory and invasive potentials, while conversely TRPV2 silencing in highly metastatic melanoma cells prevents aggressive behavior. In invasive melanoma cells, TRPV2 channel localizes at the leading edge, in dynamic nascent adhesions, and regulates calcium-mediated activation of calpain and the ensuing cleavage of the adhesive protein talin, along with F-actin organization. In human melanoma tissues, TRPV2 overexpression correlates with advanced malignancy and poor prognosis, evoking a biomarker potential. Hence, by regulating adhesion and motility, the mechanosensitive TRPV2 channel controls melanoma cell invasiveness, highlighting a new therapeutic option for migrastatics in the treatment of metastatic melanoma.
Assuntos
Melanoma , Neoplasias Cutâneas , Humanos , Canais de Cálcio/genética , Canais de Cálcio/metabolismo , Melanoma/genética , Membrana Celular/metabolismo , Neoplasias Cutâneas/genética , Canais de Cátion TRPV/genética , Movimento Celular/genética , Invasividade Neoplásica/patologia , Cálcio/metabolismoRESUMO
PURPOSE: This study sought to evaluate the biomechanical properties of the interface between the rotator cuff and the semicircular humeral ligament or rotator cable (RCa) using histological and biomechanical techniques. METHODS: Out of 13 eligible cadaver specimens, 5 cadaver shoulders with an intact rotator cuff were included, 8 were excluded due to an injured rotator cuff. The histological study enables us to describe the capsule-tendon interface between the infraspinatus tendon (IST) or supraspinatus tendon (SST) and RCa, and to detect loose connective tissue layers to determine their precise location and measure their length along the interface. The biomechanical study sought to characterize and compare the mechanical strength of the IST-RCa versus SST-RCa interfaces. RESULTS: The average thickness of the RCa was 1.44 ± 0.20 mm. The histological study revealed a loose connective tissue layer at the IST-RCa interface, a finding not observed at the SST-RCa interface. The biomechanical study showed that the rigidity of the SST-RCa interface (72.10-2 N/mm) was 4.5 times higher than for the IST-RCa interface (16.10-2 N/mm) and the average maximum forces reached were 19.0 N and 10.6 N for the SST-RCa and IST- RCa interfaces, respectively. CONCLUSION: The IST-RCa interface consists of a loose connective tissue layer contrary to the SST-RCa interface. In parallel, two different groups in terms of the mechanical response were identified: the IST-RCa interface group had less rigidity and ruptured more quickly than the SST-RCa interface, therefore emerging as the most vulnerable interface and explaining a potential extension of rotator cuff tears.
RESUMO
Raman spectroscopy is an imaging technique that has been applied to assess molecular compositions of living cells to characterize cell types and states. However, owing to the diverse molecular species in cells and challenges of assigning peaks to specific molecules, it has not been clear how to interpret cellular Raman spectra. Here, we provide firm evidence that cellular Raman spectra (RS) and transcriptomic profiles of glioblastoma can be computationally connected and thus interpreted. We find that the dimensions of high-dimensional RS and transcriptomes can be reduced and connected linearly through a shared low-dimensional subspace. Accordingly, we were able to predict global gene expression profiles by applying the calculated transformation matrix to Raman spectra and vice versa. From these analyses, we extract a minimal gene expression signature associated with specific RS profiles and predictive of disease outcome.
Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Glioblastoma/genética , Glioblastoma/patologia , Análise Espectral Raman/métodos , Transcriptoma/genética , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Following the discovery of (R)-roscovitine's beneficial effects in three polycystic kidney disease (PKD) mouse models, cyclin-dependent kinases (CDKs) inhibitors have been investigated as potential treatments. We have used various affinity chromatography approaches to identify the molecular targets of roscovitine and its more potent analog (S)-CR8 in human and murine polycystic kidneys. These methods revealed casein kinases 1 (CK1) as additional targets of the two drugs. CK1ε expression at the mRNA and protein levels is enhanced in polycystic kidneys of 11 different PKD mouse models as well as in human polycystic kidneys. A shift in the pattern of CK1α isoforms is observed in all PKD mouse models. Furthermore, the catalytic activities of both CK1ε and CK1α are increased in mouse polycystic kidneys. Inhibition of CK1ε and CK1α may thus contribute to the long-lasting attenuating effects of roscovitine and (S)-CR8 on cyst development. CDKs and CK1s may constitute a dual therapeutic target to develop kinase inhibitory PKD drug candidates.
Assuntos
Caseína Quinase 1 épsilon/antagonistas & inibidores , Caseína Quinase Ialfa/antagonistas & inibidores , Rim/efeitos dos fármacos , Doenças Renais Policísticas/prevenção & controle , Inibidores de Proteínas Quinases/farmacologia , Purinas/farmacologia , Piridinas/farmacologia , Roscovitina/farmacologia , Animais , Caseína Quinase 1 épsilon/genética , Caseína Quinase 1 épsilon/metabolismo , Caseína Quinase Ialfa/genética , Caseína Quinase Ialfa/metabolismo , Catálise , Cromatografia de Afinidade/métodos , Modelos Animais de Doenças , Humanos , Rim/enzimologia , Rim/patologia , Camundongos Transgênicos , Doenças Renais Policísticas/enzimologia , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/patologia , Ligação Proteica , Inibidores de Proteínas Quinases/metabolismo , Purinas/metabolismo , Piridinas/metabolismo , Roscovitina/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Chronic obstructive pulmonary disease (COPD) is an incurable and progressive disease. Emphysema is the principal manifestation of COPD, and the main cause of this condition is cigarette smoke (CS). Natural products have shown antioxidant and anti-inflammatory properties that can prevent acute lung inflammation and emphysema, but there are few reports in the literature regarding therapeutic approaches to emphysema. We hypothesized that supplementation with natural extracts would repair lung damage in emphysema caused by CS exposure. Mice were exposed to 60days of CS and then treated or not with three different natural extracts (mate tea, grape and propolis) orally for additional 60days. Histological analysis revealed significant improvements in lung histoarchitecture, with recovery of alveolar spaces in all groups treated with natural extracts. Propolis was also able to recovery alveolar septa and elastic fibers. Propolis also increased MMP-2 and decreased MMP-12 expression, favoring the process of tissue repair. Additionally, propolis recruited leukocytes, including macrophages, without ROS release. These findings led us to investigate the profile of these macrophages, and we showed that propolis could promote macrophage alternative activation, thus increasing the number of arginase-positive cells and IL-10 levels and favoring an anti-inflammatory microenvironment. We further investigated the participation of Nrf2 in lung repair, but no Nrf2 translocation to the nucleus was observed in lung cells. Proteins and enzymes related to Nrf2 were not altered, other than NQO1, which seemed to be activated by propolis in a Nrf2-independent manner. Finally, propolis downregulated IGF1 expression. In conclusion, propolis promoted lung repair in a mouse emphysema model via macrophage polarization from M1 to M2 in parallel to the downregulation of IGF1 expression in a Nrf2-independent manner.
Assuntos
Anti-Inflamatórios/farmacologia , Macrófagos/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/metabolismo , Própole/farmacologia , Enfisema Pulmonar/tratamento farmacológico , Fumar/tratamento farmacológico , Animais , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Enfisema Pulmonar/metabolismo , Enfisema Pulmonar/patologia , Fumar/metabolismoRESUMO
Metastatic lymph node 51 (MLN51, also known as CASC3) is a core component of the exon junction complex (EJC), which is loaded onto spliced mRNAs and plays an essential role in determining their fate. Unlike the three other EJC core components [eIF4AIII, Magoh and Y14 (also known as RBM8A)], MLN51 is mainly located in the cytoplasm, where it plays a key role in the assembly of stress granules. In this study, we further investigated the cytoplasmic role of MLN51. We show that MLN51 is a new component of processing bodies (P-bodies). When overexpressed, MLN51 localizes in novel small cytoplasmic foci. These contain RNA, show directed movements and are distinct from stress granules and P-bodies. The appearance of these foci correlates with the process of P-body disassembly. A similar reduction in P-body count is also observed in human HER2-positive (HER2(+)) breast cancer cells overexpressing MLN51. This suggests that P-body disassembly and subsequent mRNA deregulation might correlate with cancer progression.
Assuntos
Neoplasias da Mama/metabolismo , Grânulos Citoplasmáticos/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Neoplasias da Mama/genética , Citoplasma/metabolismo , Grânulos Citoplasmáticos/genética , Fator de Iniciação 4A em Eucariotos/genética , Fator de Iniciação 4A em Eucariotos/metabolismo , Células HeLa , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is associated with a poor prognosis related to early recurrence especially in the remnant liver after surgery. ICC exhibits a dense desmoplastic stroma which plays a pivotal role in ICC aggressiveness. Thus, analyzing gene deregulation in the stroma of ICC may help to identify new prognosis biomarkers and promising therapeutic targets. The aim of this study was to evaluate the clinical relevance of the matrix-remodeling enzyme lysyl oxidase-like 2 (LOXL2) expression in ICC. MATERIAL AND METHODS: LOXL2 messenger RNA levels were evaluated in microdissected tumoral stroma (TS) and in nontumoral fibrous tissue by gene expression profiling (testing set, n = 10) obtained from gene expression omnibus database and by quantitative real time polymerase chain reaction (validating set, n = 6). LOXL2 protein levels were evaluated by immunohistochemistry on a tissue microarray containing 80 independent patients. The relationship between LOXL2 expression and survival was assessed by univariate and multivariate analyses. RESULTS: LOXL2 messenger RNA levels were increased in TS, both in the testing and the validating sets (P < 0.01). These results were confirmed at a protein level, with a significantly higher LOXL2 immunostaining in TS (P < 0.01). Univariate analysis revealed that LOXL2 expression was correlated with a poor overall survival and disease-free survival (P < 0.01). Importantly, high expression of LOXL2 was an independent prognostic factor of worst overall survival (hazard ratio = 5.29, confidence interval [CI] 95% = 1.71-16.3, P < 0.01) and disease-free survival (hazard ratio = 5.55, CI 95% = 2.14-14.37, P < 0.01). CONCLUSIONS: Our study provides additional arguments for a role of extracellular matrix remodeling in ICC aggressiveness and identifies LOXL2 as a new prognostic marker and a promising therapeutic target in ICC.
Assuntos
Aminoácido Oxirredutases/metabolismo , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos , Biomarcadores Tumorais/metabolismo , Colangiocarcinoma/cirurgia , Hepatectomia , Adulto , Idoso , Idoso de 80 Anos ou mais , Aminoácido Oxirredutases/genética , Neoplasias dos Ductos Biliares/genética , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/mortalidade , Ductos Biliares Intra-Hepáticos/metabolismo , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Colangiocarcinoma/genética , Colangiocarcinoma/metabolismo , Colangiocarcinoma/mortalidade , Feminino , Seguimentos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Análise de Sobrevida , Análise Serial de TecidosRESUMO
Non-alcoholic fatty liver disease is associated with obesity, diabetes, and metabolic syndrome. The detection of systemic metabolic changes associated with alterations in the liver status during non-alcoholic fatty liver disease could improve patient follow-up. The aim of the present study was to evaluate the potential of mid-infrared fibre evanescent wave spectroscopy as a minimum-invasive method for evaluating the liver status during non-alcoholic fatty liver disease. Seventy-five mice were subjected to a control, high-fat or high-fat-high carbohydrate diets. We analysed the serum biochemical parameters and mRNA levels of hepatic genes by quantitative RT-PCR. Steatosis was quantified by image analysis. The mid-infrared spectra were acquired from serum, and then analysed to develop a predictive model of the steatosis level. Animals subjected to enriched diets were obese. Hepatic steatosis was found in all animals. The relationship between the spectroscopy-predicted and observed levels of steatosis, expressed as percentages of the liver biopsy area, was not linear. A transition around 10% steatosis was observed, leading us to consider two distinct predictive models (<10% and >10%) based on two different sets of discriminative spectral variables. The model performance was evaluated using random cross-validation (10%). The hypothesis that additional metabolic changes occur beyond this transition was supported by the fact that it was associated with increased serum ALT levels, and Col1α1 chain mRNA levels. Our data suggest that mid-infrared spectroscopy combined with statistical analysis allows identifying serum mid-infrared signatures that reflect the liver status during non-alcoholic fatty liver disease.
Assuntos
Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/sangue , Espectrofotometria Infravermelho , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo , ObesidadeRESUMO
UNLABELLED: Intrahepatic cholangiocarcinoma (ICC) is the second most common type of primary cancer in the liver. ICC is an aggressive cancer with poor prognosis and limited therapeutic strategies. The identification of new drug targets and prognostic biomarkers is an important clinical challenge for ICC. The presence of an abundant stroma is a histological hallmark of ICC. Given the well-established role of the stromal compartment in the progression of cancer diseases, we hypothesized that relevant biomarkers could be identified by analyzing the stroma of ICC. By combining laser capture microdissection and gene expression profiling, we demonstrate that ICC stromal cells exhibit dramatic genomic changes. We identified a signature of 1,073 nonredundant genes that significantly discriminate the tumor stroma from nontumor fibrous tissue. Functional analysis of differentially expressed genes demonstrated that up-regulated genes in the stroma of ICC were related to cell cycle, extracellular matrix, and transforming growth factor beta (TGFß) pathways. Tissue microarray analysis using an independent cohort of 40 ICC patients validated at a protein level the increased expression of collagen 4A1/COL4A1, laminin gamma 2/LAMC2, osteopontin/SPP1, KIAA0101, and TGFß2 genes in the stroma of ICC. Statistical analysis of clinical and pathological features demonstrated that the expression of osteopontin, TGFß2, and laminin in the stroma of ICC was significantly correlated with overall patient survival. More important, multivariate analysis demonstrated that the stromal expression of osteopontin was an independent prognostic marker for overall and disease-free survival. CONCLUSION: The study identifies clinically relevant genomic alterations in the stroma of ICC, including candidate biomarkers for prognosis, supporting the idea that tumor stroma is an important factor for ICC onset and progression.
Assuntos
Colangiocarcinoma/química , Neoplasias Hepáticas/química , Osteopontina/genética , Células Estromais/metabolismo , Idoso , Neoplasias dos Ductos Biliares , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/mortalidade , Colangiocarcinoma/patologia , Feminino , Perfilação da Expressão Gênica , Humanos , Laminina/genética , Microdissecção e Captura a Laser , Fígado/citologia , Fígado/patologia , Neoplasias Hepáticas/mortalidade , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Fator de Crescimento Transformador beta/genética , Regulação para CimaRESUMO
Merkel cell carcinoma is believed to be derived from Merkel cells after infection by Merkel cell polyomavirus (MCPyV) and other poorly understood events. Transcriptional profiling using cDNA microarrays was performed on cells from MCPy-negative and MCPy-positive Merkel cell carcinomas and isolated normal Merkel cells. This microarray revealed numerous significantly upregulated genes and some downregulated genes. The extensive list of genes that were identified in these experiments provides a large body of potentially valuable information of Merkel cell carcinoma carcinogenesis and could represent a source of potential targets for cancer therapy.
Assuntos
Carcinoma de Célula de Merkel/genética , Células de Merkel/metabolismo , Neoplasias Cutâneas/genética , Carcinoma de Célula de Merkel/virologia , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Poliomavírus das Células de Merkel/isolamento & purificação , Análise de Sequência com Séries de Oligonucleotídeos , Infecções por Polyomavirus/genética , Infecções por Polyomavirus/virologia , Neoplasias Cutâneas/virologia , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/virologiaRESUMO
Adenosine triphosphate (ATP) has been described as a danger signal activating the NOD-like receptor-family protein 3 (NLRP3)-inflammasome leading to the pro-inflammatory cytokine, interleukin (IL)-1ß, release in the lung. The NLRP3-inflammasome pathway has been previously described to be involved in experimental collagen deposition and the development of pulmonary fibrosis. The aim of the present study was to investigate the role of the NLRP3 inflammasome pathway and P2X7 purinergic receptor in the activation of human macrophages in vitro by ATP. We showed that adenosine 5'-[γ-thio]triphosphate tetralithium salt (ATPγS) and 2',3'-O-(4-benzoylbenzoyl) adenosine 5'-triphosphate (BzATP), two stable analogs of ATP, are able to potentiate the release of IL-1ß from human monocyte-derived macrophages induced by low concentration of lipopolysaccharide (LPS). However, in the same conditions no increase in IL-1α and IL-6 was observed. Immunochemistry has shown that human macrophages natively express NLRP3 and purinergic P2X7 receptors (P2X7 R). NLRP3 and IL-1ß mRNA expression were induced from LPS-primed macrophages, but also after 5-h treatment of BzATP as analysed by reverse transcription quantitative polymerase chain reaction. However, other inflammasome pathways (NLRP1, NLRP2, NLRC4, NLRP6 and AIM2) and P2X7 R were not induced by BzATP. We observed that P2X7 R antagonists, A-438079 and A-740003, were able to reduce the release of IL-1ß, but not of IL-1α and IL-6 from macrophages stimulated by ATPγS or BzATP. The present results showed the involvement of the P2X7 R-NLRP3 inflammasome pathway in the secretion of IL-1ß from ATP-stimulated human macrophages, and suggest that P2X7 R were not involved in IL-1α and IL-6 release. This study also points out that repression of the P2X7 R represents a novel potential therapeutic approach to control fibrosis in lung injury.
Assuntos
Trifosfato de Adenosina/análogos & derivados , Citocinas/metabolismo , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Macrófagos/efeitos dos fármacos , Receptores Purinérgicos P2X7/metabolismo , Trifosfato de Adenosina/farmacologia , Células Cultivadas , Citocinas/genética , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Macrófagos/metabolismo , Antagonistas do Receptor Purinérgico P2X/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Purinérgicos P2X7/genéticaRESUMO
BACKGROUND: A unique feature of fish is that new muscle fibres continue to be produced throughout much of the life cycle; a process termed muscle hyperplasia. In trout, this process begins in the late embryo stage and occurs in both a discrete, continuous layer at the surface of the primary myotome (stratified hyperplasia) and between existing muscle fibres throughout the myotome (mosaic hyperplasia). In post-larval stages, muscle hyperplasia is only of the mosaic type and persists until 40% of the maximum body length is reached. To characterise the genetic basis of myotube neoformation in trout, we combined laser capture microdissection and microarray analysis to compare the transcriptome of hyperplastic regions of the late embryo myotome with that of adult myotomal muscle, which displays only limited hyperplasia. RESULTS: Gene expression was analysed using Agilent trout oligo microarrays. Our analysis identified more than 6800 transcripts that were significantly up-regulated in the superficial hyperplastic zones of the late embryonic myotome compared to adult myotomal muscle. In addition to Pax3, Pax7 and the fundamental myogenic basic helix-loop-helix regulators, we identified a large set of up-regulated transcriptional factors, including Myc paralogs, members of Hes family and many homeobox-containing transcriptional regulators. Other cell-autonomous regulators overexpressed in hyperplastic zones included a large set of cell surface proteins belonging to the Ig superfamily. Among the secreted molecules found to be overexpressed in hyperplastic areas, we noted growth factors as well as signalling molecules. A novel finding in our study is that many genes that regulate planar cell polarity (PCP) were overexpressed in superficial hyperplastic zones, suggesting that the PCP pathway is involved in the oriented elongation of the neofibres. CONCLUSION: The results obtained in this study provide a valuable resource for further analysis of novel genes potentially involved in hyperplastic muscle growth in fish. Ultimately, this study could yield insights into particular genes, pathways or cellular processes that may stimulate muscle regeneration in other vertebrates.
Assuntos
Desenvolvimento Embrionário/genética , Hiperplasia/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Truta , Animais , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Hiperplasia/patologia , Microdissecção e Captura a Laser , Músculo Esquelético/citologia , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/metabolismo , Truta/genética , Truta/crescimento & desenvolvimentoRESUMO
Although carbon tetrachloride (CCl(4))-induced acute and chronic hepatotoxicity have been extensively studied, little is known about the very early in vivo effects of this organic solvent on oxidative stress and mitochondrial function. In this study, mice were treated with CCl(4) (1.5 ml/kg ie 2.38 g/kg) and parameters related to liver damage, lipid peroxidation, stress/defense and mitochondria were studied 3 h later. Some CCl(4)-intoxicated mice were also pretreated with the cytochrome P450 2E1 inhibitor diethyldithiocarbamate or the antioxidants Trolox C and dehydroepiandrosterone. CCl(4) induced a moderate elevation of aminotransferases, swelling of centrilobular hepatocytes, lipid peroxidation, reduction of cytochrome P4502E1 mRNA levels and a massive increase in mRNA expression of heme oxygenase-1 and heat shock protein 70. Moreover, CCl(4) intoxication induced a severe decrease of mitochondrial respiratory chain complex IV activity, mitochondrial DNA depletion and damage as well as ultrastructural alterations. Whereas DDTC totally or partially prevented all these hepatic toxic events, both antioxidants protected only against liver lipid peroxidation and mitochondrial damage. Taken together, our results suggest that lipid peroxidation is primarily implicated in CCl(4)-induced early mitochondrial injury. However, lipid peroxidation-independent mechanisms seem to be involved in CCl(4)-induced early hepatocyte swelling and changes in expression of stress/defense-related genes. Antioxidant therapy may not be an efficient strategy to block early liver damage after CCl(4) intoxication.
Assuntos
Intoxicação por Tetracloreto de Carbono/metabolismo , Hepatócitos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Animais , Antioxidantes/farmacologia , Tetracloreto de Carbono , Cromanos/farmacologia , Inibidores do Citocromo P-450 CYP2E1 , Desidroepiandrosterona/farmacologia , Ditiocarb/farmacologia , Masculino , Camundongos , Mitocôndrias Hepáticas/efeitos dos fármacosRESUMO
Gene expression profiling has recently emerged as a promising approach to identify early target genes and discriminate genotoxic carcinogens from non-genotoxic carcinogens and non-carcinogens. However, early gene changes induced by genotoxic compounds in human liver remain largely unknown. Primary human hepatocytes and differentiated HepaRG cells were exposed to aflatoxin B1 (AFB1) that induces DNA damage following enzyme-mediated bioactivation. Gene expression profile changes induced by a 24h exposure of these hepatocyte models to 0.05 and 0.25µM AFB1 were analyzed by using oligonucleotide pangenomic microarrays. The main altered signaling pathway was the p53 pathway and related functions such as cell cycle, apoptosis and DNA repair. Direct involvement of the p53 protein in response to AFB1 was verified by using siRNA directed against p53. Among the 83 well-annotated genes commonly modulated in two pools of three human hepatocyte populations and HepaRG cells, several genes were identified as altered by AFB1 for the first time. In addition, a subset of 10 AFB1-altered genes, selected upon basis of their function or tumor suppressor role, was tested in four human hepatocyte populations and in response to other chemicals. Although they exhibited large variable inter-donor fold-changes, several of these genes, particularly FHIT, BCAS3 and SMYD3, were found to be altered by various direct and other indirect genotoxic compounds and unaffected by non-genotoxic compounds. Overall, this comprehensive analysis of early gene expression changes induced by AFB1 in human hepatocytes identified a gene subset that included several genes representing potential biomarkers of genotoxic compounds.
Assuntos
Aflatoxina B1/toxicidade , Dano ao DNA/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Mutagênicos/toxicidade , Aflatoxina B1/administração & dosagem , Ciclo Celular/efeitos dos fármacos , Células Cultivadas , Reparo do DNA/efeitos dos fármacos , Relação Dose-Resposta a Droga , Perfilação da Expressão Gênica , Hepatócitos/patologia , Humanos , Mutagênicos/administração & dosagem , Análise de Sequência com Séries de Oligonucleotídeos , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismoRESUMO
Our objectives were to better characterize the colorectal function of patients with Spina Bifida (SB). Patients with SB and healthy volunteers (HVs) completed prospectively a standardized questionnaire, clinical evaluation, rectal barostat, colonoscopy with biopsies and faecal collection. The data from 36 adults with SB (age: 38.8 [34.1-47.2]) were compared with those of 16 HVs (age: 39.0 [31.0-46.5]). Compared to HVs, rectal compliance was lower in patients with SB (p = 0.01), whereas rectal tone was higher (p = 0.0015). Ex vivo paracellular permeability was increased in patients with SB (p = 0.0008) and inversely correlated with rectal compliance (r = - 0.563, p = 0.002). The expression of key tight junction proteins and inflammatory markers was comparable between SB and HVs, except for an increase in Claudin-1 immunoreactivity (p = 0.04) in SB compared to HVs. TGFß1 and GDNF mRNAs were expressed at higher levels in patients with SB (p = 0.02 and p = 0.008). The levels of acetate, propionate and butyrate in faecal samples were reduced (p = 0.04, p = 0.01, and p = 0.02, respectively). Our findings provide evidence that anorectal and epithelial functions are altered in patients with SB. The alterations in these key functions might represent new therapeutic targets, in particular using microbiota-derived approaches.Clinical Trials: NCT02440984 and NCT03054415.
Assuntos
Besouros , Disrafismo Espinal , Adulto , Animais , Colo , Colonoscopia , Humanos , Reto , Inquéritos e QuestionáriosRESUMO
This study reports on the characterization of B cells of germinal center (GC)-like structures infiltrating the salivary glands (SGs) of patients with Sjögren's syndrome. Eight two-color combinations were devised to characterize the phenotype of these B cells in 11 SG specimens selected from biopsies obtained from 40 Sjögren's syndrome patients and three normal tonsils. The 9G4 mAb, which recognizes V4.34-encoded autoAbs, enabled us to identify autoreactive B cells. Quantitative RT-PCR was used to determine the level of mRNAs for activation-induced cytidine deaminase (AICDA), repressors and transcription factors. CD20(+)IgD(-)CD38(+)CD21(+)CD24(-) B cells, similar to those identified in tonsil GCs, were seen in the SGs of four patients and, and since they expressed AICDA, they were termed "real GCs". CD20(+)IgD(+)CD38(-)CD21(+)CD24(+) B cells, seen in aggregates from the remaining seven samples, were characteristically type 2 transitional B cells and marginal zone-type B cells. They lacked AICDA mRNAs and were termed "aggregates". Real GCs from SGs contained mRNAs for Pax-5 and Bcl-6, like tonsil GC cells, whereas aggregates contained mRNAs for Notch-2, Blimp-1, IRF-4, and BR3, similar to marginal zone B cells. Further experimental data in support of this dichotomy included the restriction of CXCR5 expression to real GC cells, while sphingosine 1-phosphate receptor 1 was expressed only in aggregates. In contrast, both types of B cell clusters expressed the idiotype recognized by the 9G4 mAb. Our data indicate that, in SGs, a minority of B cell clusters represent genuine GC cells, while the majority manifest features of being type 2 transitional B cells and marginal zone cells. Interestingly, both types of B cell aggregates include autoreactive B cells.
Assuntos
Autoanticorpos/metabolismo , Subpopulações de Linfócitos B/imunologia , Subpopulações de Linfócitos B/patologia , Centro Germinativo/imunologia , Centro Germinativo/patologia , Glândulas Salivares/imunologia , Síndrome de Sjogren/imunologia , Síndrome de Sjogren/patologia , Adolescente , Adulto , Idoso , Autoanticorpos/biossíntese , Subpopulações de Linfócitos B/metabolismo , Criança , Pré-Escolar , Citidina Desaminase/biossíntese , Citidina Desaminase/genética , Feminino , Centro Germinativo/metabolismo , Humanos , Imunofenotipagem , Pessoa de Meia-Idade , Tonsila Palatina/citologia , Tonsila Palatina/imunologia , Tonsila Palatina/metabolismo , Glândulas Salivares/metabolismo , Glândulas Salivares/patologia , Síndrome de Sjogren/metabolismoRESUMO
OBJECTIVE: Purposes of this work were i) to develop an in silico model of tumor response to radiotherapy, ii) to perform an exhaustive sensitivity analysis in order to iii) propose a simplified version and iv) to predict biochemical recurrence with both the comprehensive and the reduced model. METHODS: A multiscale computational model of tumor response to radiotherapy was developed. It integrated the following radiobiological mechanisms: oxygenation, including hypoxic death; division of tumor cells; VEGF diffusion driving angiogenesis; division of healthy cells and oxygen-dependent response to irradiation, considering, cycle arrest and mitotic catastrophe. A thorough sensitivity analysis using the Morris screening method was performed on 21 prostate computational tissues. Tumor control probability (TCP) curves of the comprehensive model and 15 reduced versions were compared. Logistic regression was performed to predict biochemical recurrence after radiotherapy on 76 localized prostate cancer patients using an output of the comprehensive and the reduced models. RESULTS: No significant difference was found between the TCP curves of the comprehensive and a simplified version which only considered oxygenation, division of tumor cells and their response to irradiation. Biochemical recurrence predictions using the comprehensive and the reduced models improved those made from pre-treatment imaging parameters (AUC = 0.81 ± 0.02 and 0.82 ± 0.02 vs. 0.75 ± 0.03, respectively). CONCLUSION: A reduced model of tumor response to radiotherapy able to predict biochemical recurrence in prostate cancer was obtained. SIGNIFICANCE: This reduced model may be used in the future to optimize personalized fractionation schedules.
Assuntos
Neoplasias da Próstata , Simulação por Computador , Humanos , Masculino , Neoplasias da Próstata/radioterapiaRESUMO
Aerosol lung gene therapy using non-viral delivery systems represents a credible therapeutic strategy for chronic respiratory diseases, such as cystic fibrosis (CF). Progress in CF clinical setting using the lipidic formulation GL67A has demonstrated the relevance of such a strategy while emphasizing the need for more potent gene transfer agents. In recent years, many novel non-viral gene delivery vehicles were proposed as potential alternatives to GL67 cationic lipid. However, they were usually evaluated using procedures difficult or even impossible to implement in clinical practice. In this study, a clinically-relevant administration protocol via aerosol in murine lungs was used to conduct a comparative study with GL67A. Diverse lipidic compounds were used to prepare a series of formulations inspired by the composition of GL67A. While some of these formulations were ineffective at transfecting murine lungs, others demonstrated modest-to-very-efficient activities and a series of structure-activity relationships were unveiled. Lipidic aminoglycoside derivative-based formulations were found to be at least as efficient as GL67A following aerosol delivery of a luciferase-encoding plasmid DNA. A single aerosol treatment with one such formulation was found to mediate long-term lung transgene expression, exceeding half the animal's lifetime. This study clearly supports the potential of aminoglycoside-based cationic lipids as potent GL67-alternative scaffolds for further enhanced aerosol non-viral lung gene therapy for diseases such as CF.
RESUMO
Sciadonic acid (Scia) is a Δ5-olefinic fatty acid that is particularly abundant in edible pine seeds and that exhibits an unusual polymethylene-interrupted structure. Earlier studies suggested that Scia inhibited the in vitro expression and activity of the Stearoyl-CoA Desaturase 1 (SCD1), the hepatic Δ9-desaturase involved in the formation of mono-unsaturated fatty acids. To confirm this hypothesis, rats were given 10% Scia in diets balanced out with n-6 and n-3 fatty acids. In those animals receiving the Scia supplement, monoene synthesis in the liver was reduced, which was partly attributed to the inhibition of SCD1 expression. As a consequence, the presence of Scia induced a 50% decrease in triglycerides in blood plasma due to a reduced level of VLDL-secreted triglycerides from the liver. In non-fasting conditions, results showed that Scia-induced inhibition of SCD1 led to a decrease in the proportions of 16:1n-7 and 18:1n-7 in the liver without impacting on the level of 18:1n-9, suggesting that only triglycerides with neosynthesized monoenes are marked out for release. In conclusion, this in vivo study confirms that Scia highly inhibits SCD1 expression and activity. The work was performed on normo-triglyceride rats over six weeks, suggesting promising effects on hyper-triglyceridemic models.