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










Base de dados
Intervalo de ano de publicação
1.
Exp Ther Med ; 28(2): 327, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38979018

RESUMO

Extra-adrenal myelolipoma (EAM) is a rare benign tumor composed of mature adipose and hematopoietic tissues. Its etiology remains to be elucidated and there are few case reports describing the clinical features and treatment of EAMs in the central nervous system. The present study presented our experience and practice in the clinical management of a case of EAM in the right frontal region. A 56-year-old woman was found to have a space-occupying right frontal lesion on computed tomography (CT) of the head. Unenhanced magnetic resonance imaging (MRI) showed a lesion of ~1.5x1.2 cm. Enhanced whole abdominal CT showed a right presacral mass, 2.0 cm in diameter, with clear margins. The postoperative histopathological findings showed mainly mature adipose tissue mixed with extramedullary hematopoietic components. This confirmed the diagnosis of a (bone) marrow lipoma. Myelolipoma of the central nervous system is extremely rare. to the best of the authors' knowledge, only two cases of intracranial myelolipoma have been reported, and the present study introduced the first case in a Chinese patient reported in English. However, when CT shows high density and MRI shows mixed density in the tumor area even without enhancement, the possibility of myelolipoma should be considered in the differential diagnosis.

2.
Nat Commun ; 15(1): 5256, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898040

RESUMO

Archaea possess characteristic membrane-spanning lipids that are thought to contribute to the adaptation to extreme environments. However, the biosynthesis of these lipids is poorly understood. Here, we identify a radical S-adenosyl-L-methionine (SAM) enzyme that synthesizes glycerol monoalkyl glycerol tetraethers (GMGTs). The enzyme, which we name GMGT synthase (Gms), catalyzes the formation of a C(sp3)-C(sp3) linkage between the two isoprenoid chains of glycerol dialkyl glycerol tetraethers (GDGTs). This conclusion is supported by heterologous expression of gene gms from a GMGT-producing species in a methanogen, as well as demonstration of in vitro activity using purified Gms enzyme. Additionally, we show that genes encoding putative Gms homologs are present in obligate anaerobic archaea and in metagenomes obtained from oxygen-deficient environments, and appear to be absent in metagenomes from oxic settings.


Assuntos
Archaea , Oxigênio , S-Adenosilmetionina , S-Adenosilmetionina/metabolismo , Archaea/genética , Archaea/metabolismo , Archaea/enzimologia , Oxigênio/metabolismo , Anaerobiose , Proteínas Arqueais/metabolismo , Proteínas Arqueais/genética , Glicerol/metabolismo , Metagenoma , Filogenia
3.
Neuro Endocrinol Lett ; 44(6): 410-417, 2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37776558

RESUMO

BACKGROUND: Cranionasal communicating tumors often originate from the extra-axial intracranial tissue, nasal cavity, and sinuses, and mostly invade the anterior skull base, leading to communication between the cranial and nasal cavities. Cranionasal communicating tumors are clinically rare and thus have been rarely reported in the literature. OBJECTIVE: To investigate the clinical outcomes of combined transcranial and endoscopic transnasal approaches in the surgical management of cranionasal communicating tumors. METHODS: We retrospectively analyzed patients with cranionasal communicating tumors treated at the Department of Neurosurgery, Jinhua Hospital, affiliated with Zhejiang University, from July 2017 to March 2020. All patients were surgically treated using combined transcranial and endoscopic transnasal approaches or the cranionasal dual approach, and skull base reconstruction was performed simultaneously. The postoperative gross tumor resection rate, perioperative complications, and postoperative efficacy were evaluated. RESULTS: Eleven patients with 14-37 months of follow-up were included. Eight patients underwent total resection, two patients underwent subtotal resection, and one patient was treated with partial resection. Postoperative pathological diagnoses revealed four olfactory neuroblastomas, three atypical meningiomas, two recurrent papilloma malignancies, one recurrent invasive pituitary tumor, and one recurrent invasive pituitary adenocarcinoma. Among the 11 patients, severe cerebral edema was observed postoperatively in one patient, and decompression craniectomy was performed. Intracranial infection was observed in two patients, including one with transient cerebrospinal fluid leakage, which was cured after symptomatic treatment. Moreover, postoperative ocular dysmotility and worse olfactory sensation were observed in one and two patients, respectively. The mean follow-up time of the 11 patients was (24.4 ± 5.7) months. The one-year survival rate of the patients was 100%; 10 patients (90.9%) had a favorable outcome (Glasgow Outcome Scale score of 4-5), and only one patient (9.1%) had a Glasgow Outcome Scale score of 3. Furthermore, during the last follow-up, tumor recurrence occurred in two patients (18.2%). CONCLUSION: Surgical treatment of cranionasal communicating tumors using the cranionasal dual approach and simultaneous skull base reconstruction improves the gross tumor resection rate with fewer postoperative complications and good short-term efficacy.


Assuntos
Adenocarcinoma , Neoplasias Nasais , Neoplasias da Base do Crânio , Humanos , Estudos Retrospectivos , Recidiva Local de Neoplasia , Endoscopia , Base do Crânio/patologia , Base do Crânio/cirurgia , Neoplasias da Base do Crânio/cirurgia , Neoplasias Nasais/cirurgia , Resultado do Tratamento
4.
Environ Microbiol ; 25(2): 575-587, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36495168

RESUMO

Glycerol dibiphytanyl glycerol tetraethers (GDGTs) are unique archaeal membrane-spanning lipids with 0-8 cyclopentane rings on the biphytanyl chains. The cyclization pattern of GDGTs is affected by many environmental factors, such as temperature and pH, but the underlying molecular mechanism remains elusive. Here, we find that the expression regulation of GDGT ring synthase genes grsA and grsB in thermophilic archaeon Sulfolobus acidocaldarius is temperature- and pH-dependent. Moreover, the presence of functional GrsA protein, or more likely its products cyclic GDGTs rather than the accumulation of GrsA protein itself, is required to induce grsB expression, resulting in temporal regulation of grsA and grsB expression. Our findings establish a molecular model of GDGT cyclization regulated by environment factors in a thermophilic ecosystem, which could be also relevant to that in mesophilic marine archaea. Our study will help better understand the biological basis for GDGT-based paleoclimate proxies. Archaea inhabit a wide range of terrestrial and marine environments. In response to environment fluctuations, archaea modulate their unique membrane GDGTs lipid composition with different strategies, in particular GDGTs cyclization significantly alters membrane permeability. However, the regulation details of archaeal GDGTs cyclization in response to different environmental factor changes remain unknown. We demonstrated, for the first time, thermophilic archaea orchestrate the temporal expression of GDGT ring synthases, leading to delicate control of GDGTs cyclization to respond environmental temperature and acidity stress. Our study provides insight into the regulation of archaea membrane plasticity, and the survival strategy of archaea in fluctuating environments.


Assuntos
Archaea , Ecossistema , Archaea/metabolismo , Temperatura , Glicerol/metabolismo , Lipídeos de Membrana/metabolismo
5.
Dis Markers ; 2022: 4764028, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35928926

RESUMO

Objective: To study the effect of circ_0000512 (circRPPH1_025) on the tumorigensis and development of glioblastoma and its molecular mechanism. Methods: The expression levels of circ_0000512 in normal astrocytes (NHA) and human glioblastoma cell lines (U87, U251, and A172) and the expression levels of circ_0000512 and linear RNA RPPH1 in U87 cells after RNase R treatment were detected by qRT-PCR. The effects of circ_0000512 knockdown or overexpression on the proliferation, migration, invasion, and epithelial-mesenchymal transition of U87 cells were detected by CCK-8 assay, cell colony formation assay, transwell invasion assay, wound healing assay, and western blot. Results: The expression of circ_0000512 was upregulated in glioblastoma cells, and the overexpression of circ_0000512 was beneficial to the proliferation, migration, invasion, and epithelial-mesenchymal transition of U87 cells, while knockdown of circ_0000512 showed the opposite results. Conclusion: circ_0000512 can be used as a potential target for early diagnosis and targeted therapy of glioblastoma multiforme.


Assuntos
Neoplasias Encefálicas , Glioblastoma , MicroRNAs , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , MicroRNAs/genética , RNA Circular/genética
6.
Nat Commun ; 13(1): 1545, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35318330

RESUMO

Glycerol dibiphytanyl glycerol tetraethers (GDGTs) are archaeal monolayer membrane lipids that can provide a competitive advantage in extreme environments. Here, we identify a radical SAM protein, tetraether synthase (Tes), that participates in the synthesis of GDGTs. Attempts to generate a tes-deleted mutant in Sulfolobus acidocaldarius were unsuccessful, suggesting that the gene is essential in this organism. Heterologous expression of tes homologues leads to production of GDGT and structurally related lipids in the methanogen Methanococcus maripaludis (which otherwise does not synthesize GDGTs and lacks a tes homolog, but produces a putative GDGT precursor, archaeol). Tes homologues are encoded in the genomes of many archaea, as well as in some bacteria, in which they might be involved in the synthesis of bacterial branched glycerol dialkyl glycerol tetraethers.


Assuntos
Archaea , Sulfolobus acidocaldarius , Archaea/genética , Archaea/metabolismo , Bactérias/metabolismo , Glicerol/metabolismo , Lipídeos de Membrana/metabolismo , Sulfolobus acidocaldarius/genética , Sulfolobus acidocaldarius/metabolismo
7.
J Nanosci Nanotechnol ; 21(10): 5235-5240, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33875112

RESUMO

In Situ transformed carbon fibers/Al2O3 ceramic matrix nanocomposites with Cao-MgO-SiO2 sintering agent were prepared by hot-pressed sintering technology in vacuum. In the sintering process, pre-oxidized polyacrylonitrile fibers (below named as pre-oxidized PAN fibers) were used as the precursors of In Situ transformed carbon fibers. The micro/nanostructure of composites and interface between In Situ transformed carbon fibers and matrix were investigated, as well as the properties of composites. The results showed that the composites could be sintered well at a relatively low temperature of 1650 °C. During the sintering, the precursors, pre-oxidized PAN fibers, were In Situ transformed into carbon fibers, and the In Situ transformed carbon fibers had the graphitelike structure along the fiber axial direction. The carbon atoms arrangement in the surface layer of the fiber was more orderly than the core. A typical diffraction peak of carbon fiber at 26°, which corresponded to the (002) crystal plane, was observed, and the inter-planar spacing was approximately 0.34 nm. The CaO-MgO-SiO2 sintering agent formed MgAl2O4 and CaAl2Si2O8 phases in the interface between In Situ transformed carbon fibers and matrix, therefore improving the interface bonding, and thereby modifying the mechanical properties of the composites.

8.
Talanta ; 206: 120177, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514882

RESUMO

Two highly selective OFF-ON isomer fluorescent probes (1 and 2) for homo-/cysteine were designed and synthesized. The pyrene modified tetraphenylethylene derivative with AIE was used as luminescent group while maleimide was used as recognition group. These two isomer probes were found to be nearly nonfluorescent when treated with GSH. However, upon interaction with Cys or Hcy, the fluorescence was enhanced by 2000 folds in a wide pH range from 3 to 10. Experimental results and DFT calculation have demonstrated that the fluorescence OFF-ON switch of such thiol probes is resulted from the termination of the PET (photo-induced electron transfer) effect through the Michael addition reaction of maleimide unit and thiols. In addition, probe 1 and 2 exhibit excellent selectivity and sensitivity towards Cys, Hcy over GSH and other amino acids, which was confirmed by mass MS. We suggested that Michael addition reaction of these probes with GSH was prevented because of the stereo-hindrance effect. Furthermore, these two isomer probes were successfully used for imaging biothiols in living H1299 lung cancer cells.


Assuntos
Cisteína/análise , Corantes Fluorescentes/química , Glutationa/química , Homocisteína/análise , Linhagem Celular Tumoral , Cisteína/química , Teoria da Densidade Funcional , Fluorescência , Corantes Fluorescentes/síntese química , Homocisteína/química , Humanos , Maleimidas/síntese química , Maleimidas/química , Microscopia de Fluorescência/métodos , Modelos Químicos , Estilbenos/síntese química , Estilbenos/química
9.
Fish Shellfish Immunol ; 69: 211-217, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28860073

RESUMO

miR-92a, a well-documented oncogene, was previously found to be differentially expressed in diseased sea cucumber Apostichopus japonicus by high-throughput sequencing. In this study, we identified Aj14-3-3ζ as a novel target of miR-92a in this species and investigated their regulatory roles in vivo. The negative expression profiles between miR-92a and Aj14-3-3ζ protein were detected in both LPS-exposed primary coelomocytes and Vibrio splendidus-challenged sea cucumbers. Over-expression of miR-92a by injection of miR-92a agomir significantly depressed the mRNA and protein expression of Aj14-3-3ζ and promoted coelomocytes apoptosis with 5.04-fold increase in vivo, which was consistent with those from siRNA-mediated Aj14-3-3ζ knockdown assay. In contrast, miR-92a antagomir significantly elevated the mRNA and protein expression of Aj14-3-3ζ and decreased coelomocytes apoptosis. Taken together, our result confirmed that miR-92a is involved in apoptotic signaling pathway regulation perhaps via targeting Aj14-3-3ζ in sea cucumbers, which will enhance our understanding of miR-92a regulatory roles in sea cucumber pathogenesis.


Assuntos
Proteínas 14-3-3/genética , Apoptose/genética , Regulação da Expressão Gênica , Imunidade Inata , MicroRNAs/genética , Stichopus/genética , Stichopus/imunologia , Animais , Transdução de Sinais , Transcriptoma
10.
Fish Shellfish Immunol ; 69: 26-34, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28797638

RESUMO

Tumor necrosis factor (TNF)-α-induced protein 8 (TNFAIP8) family is a newly identified protein with vital roles in maintaining immune homeostasis. In the current study, we first cloned and characterized a TNFAIP8 gene from the invertebrate sea cucumber Apostichopus japonicus. The gene was designated as AjTNFAIP8. The full-length cDNA of AjTNFAIP8 was 1455 bp long and encoded a matured protein of 201 amino acid residues. Structural analysis indicated that AjTNFAIP8 had a death effector domain (DED)-like domain and composed of six α-helices. Multiple sequence alignment and phylogenetic analysis supported that AjTNFAIP8 is a new member of the TNFAIP8 family. Analysis of basal transcription in five tissues revealed the constitutive expression of AjTNFAIP8 in the detected tissues with highest expression in the respiratory tree and minimum expression in the tentacle. Vibrio splendidus infection and LPS stimulation could significantly downregulate the mRNA expression of AjTNFAIP8. More importantly, the transcription of pro-inflammatory molecule NOS and its production of NO content were significantly increased after AjTNFAIP8 silencing, with the suppression of agmatinase transcript and arginase activity. These results clearly indicated that AjTNFAIP8 is an essential negative regulator in innate immunity. Basic information for further exploration of the functional mechanisms of TNFAIP8 family in other marine invertebrate is provided.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Arginina/metabolismo , Imunidade Inata/genética , Stichopus/genética , Stichopus/metabolismo , Sequência de Aminoácidos , Animais , Proteínas Reguladoras de Apoptose/química , Sequência de Bases , Filogenia , Alinhamento de Sequência , Stichopus/imunologia
11.
Dev Comp Immunol ; 76: 65-76, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28549733

RESUMO

Cytochrome c plays crucial roles in apoptosis and the immune response. We previously demonstrated that cathepsin B from Apostichopus japonicus (AjCTSB) induces coelomocyte apoptosis. However, the mechanistic explanation and the regulation of this process have not been investigated. In the present study, we identified three cytochrome c cDNAs from A. japonicus (designated Ajcytc1, Ajcytc-1, and Ajcytc-2) using expressed sequence tag- (EST) and RACE-based approaches. The deduced amino acid sequences of the three cytochrome isoforms contained conserved CXXCH motifs, which are involved in binding heme and maintaining proteolytic activity. Time course expression analysis in vitro and in vivo revealed that the three cytochrome isoforms were induced upon pathogen challenge and LPS exposure. More importantly, AjCTSB knockdown by siRNA dramatically increased mitochondrial membrane potential (ΔΨm) in a time-dependent manner based on JC-1 fluorescent probe staining. AjCTSB knockdown also resulted in decreased expression of these three cytochromes 24 h after siAjCTSB transfection. Functional analysis using isoform-specific siRNAs revealed that Ajcytc-1, but not Ajcytc1 or Ajcytc-2, is involved in coelomocyte apoptosis. Moreover, the transcript level of Ajcaspase-3, an apoptosis executioner, was also consistently down-regulated upon silencing of Ajcytc-1 but not Ajcytc1 or Ajcytc-2. Collectively, these results indicate that Ajcytc1, Ajcytc-1, and Ajcytc-2 play distinct roles in mediating the immune response to bacteria according to AjCTSB expression. Moreover, Ajcytc-1 could be released upon dissipation of the ΔΨm, which could further trigger coelomocyte apoptosis through the activation of Ajcaspase-3.


Assuntos
Apoptose/genética , Catepsina B/genética , Citocromos c/genética , Stichopus/genética , Sequência de Aminoácidos , Animais , Bactérias/imunologia , Sequência de Bases , Clonagem Molecular/métodos , Citocromos c/imunologia , DNA Complementar/genética , Filogenia , Isoformas de Proteínas/genética , Isoformas de Proteínas/imunologia , RNA Interferente Pequeno/genética
12.
Dev Comp Immunol ; 67: 86-96, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27832949

RESUMO

MicroRNAs (miRNAs) have emerged as key regulators in the host immune response and play a pivotal role in host-pathogen interactions by suppressing the transcriptional and post-transcriptional expression of target genes. miR-137, a well-documented tumor repressor, was previously found by high-throughput sequencing to be differentially expressed in diseased specimens of the sea cucumber Apostichopus japonicus. In this study, we identified 14-3-3ζ protein (Aj14-3-3ζ) as a novel target of miR-137 using isobaric tags for relative and absolute quantification (iTRAQ) and transcriptome screening. Expression analysis indicated that consistently depressed expression profiles of miR-137 and Aj14-3-3ζ were detected in both LPS-exposed primary coelomocytes and Vibrio splendidus-challenged sea cucumbers, suggesting a positive regulatory interaction. Consistently, miR-137 overexpression or inhibition in vitro and in vivo showed no effect on Aj14-3-3ζ mRNA levels, but the concentration of Aj14-3-3ζ protein was induced or repressed, respectively. Moreover, siRNA-mediated Aj14-3-3ζ knockdown in vivo decreased both mRNA and protein expression levels of Aj14-3-3ζ and significantly promoted coelomocyte apoptosis as assessed by flow cytometry, consistent with miR-137 inhibition. Overall, these results enhance our understanding of miR-137 regulatory roles in sea cucumber pathogenesis.


Assuntos
Proteínas 14-3-3/metabolismo , Apoptose , MicroRNAs/genética , Fagócitos/imunologia , Pepinos-do-Mar/imunologia , Vibrioses/imunologia , Vibrio/imunologia , Proteínas 14-3-3/genética , Animais , Células Cultivadas , Interações Hospedeiro-Patógeno , Imunidade Inata/genética , Lipopolissacarídeos/imunologia , Proteômica , RNA Interferente Pequeno/genética
13.
Fish Shellfish Immunol ; 60: 447-457, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27847342

RESUMO

Cathepsin B (CTSB), a member of lysosomal cysteine protease, is involved in multiple levels of physiological and biological processes, and also plays crucial roles in host immune defense against pathogen infection in vertebrates. However, the function of CTSB within the innate immune system of invertebrates, particularly in marine echinoderms, has been poorly documented. In this study, the immune function of CTSB in Apostichopus japonicus (designated as AjCTSB), a commercially important and disease vulnerable aquaculture specie, was investigated by integrated molecular and protein approaches. A 2153 bp cDNA representing the full-length of AjCTSB was cloned via overlapping ESTs and RACE fragments. AjCTSB contained an open reading frame of 999 bp encoding a secreted protein of 332 amino acid residues with a predicted molecular mass of 36.8 kDa. The deduced amino acid of AjCTSB shared a typical activity center containing three conserved amino acid residues (Cys108, His277 and Asn297). Phylogenetic tree analysis also supported that AjCTSB was a new member of CTSB family with clustering firstly with invertebrate CTSBs. Quantitative real time PCR analysis revealed that AjCTSB was ubiquitously expressed in all examined tissues with the highest levels in intestine. The Vibrio splendidus challenged sea cucumber and LPS-exposed coelomocytes could both significantly boost the expression of AjCTSB. Moreover, the purified recombinant AjCTSB exhibited dose-dependent CTSB activities at the concentration ranged from 0 to 0.24 µg µL-1. Further functional analysis indicated that coelomocytes apoptosis was significantly inhibited by 0.16-fold in vivo and the apoptosis execution Ajcaspase 3 was extremely reduced in Apostichopus japonicus coelomocytes treated with specific AjCTSB siRNA. Collectively, all these results suggested that AjCTSB was an important immune factor and might be served as apoptosis enhancers in pathogen challenged sea cucumber.


Assuntos
Catepsina B/genética , Catepsina B/metabolismo , Regulação da Expressão Gênica , Imunidade Inata , Stichopus/genética , Stichopus/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Catepsina B/química , Catepsina B/imunologia , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Lipopolissacarídeos/farmacologia , Filogenia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Stichopus/microbiologia , Vibrio/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...