Research progress on vesicle-associated membrane protein 8 / 中国生物制品学杂志

@#Membrane fusion is essential for all life activities of eukaryotes and the fusion process requires the interaction of different vesicular transporters,which are highly conserved in eukaryotes,to coordinate specifically and facilitate the fusion of different biofilms. Vesicle associated membrane protein 8(VAMP8)mainly locates in vesicular as well as lysosomal membranes,and plays a vital role in the fusion of many different biofilms. This paper focused on the molecular structure,transcriptional regulation,post-translational modification and biological function of VAMP8 as well as the research progress on its correlation with human diseases,so as to provide new ideas for the treatment of related diseases and the development of effective therapeutics targeting VAMP8.

Identification of new human mesenchymal stem cell biomarker by aptamers / Identificação de novos biomarcadores de células tronco mesenquimais de origem humana por meio de aptâmeros

Stem cells are undifferentiated cells that can be distinguished from others by their ability to self-renew and to differentiate into new specific cell types. Mesenchymal stem cells (MSC) are adult stem cells that can be obtained from different sources, such as adipose tissue, bone marrow, dental pulp, and umbilical cord. They can either replicate, originating new identical cells, or differentiate into cells of mesodermal origin and from other germ layers. MSC have been studied as new tools for regenerative therapy. Although encouraging results have been demonstrated, MSC-based therapies still face a great barrier: the difficulty of isolating these cells from heterogeneous environments. MSC are currently characterized by immunolabelling through a set of multiple surface membrane markers, including CD29, CD73, CD90 and CD105, which are also expressed by other cell types. Hence, the present work aimed to identify new specific biomarkers for the characterization of human MSC using DNA aptamers produced by the SELEX (Systematic Evolution of Ligands by EXponential Enrichment) technique. Our results showed that MSC from different origins bound to DNA candidate aptamers, that is, DNA or RNA oligonucleotides selected from random libraries that bind specifically to biological targets. Aptamer-bound MSC could be isolated by fluorescenceactivated cell sorting (FACS) procedures, enhancing the induction of differentiation into specific phenotypes (chondrocytes, osteocytes and adipocytes) when compared to the whole MSC population. Flow cytometry analyses revealed that candidate aptamers bound to 50% of the MSC population from dental pulp and did not present significant binding rates to human fibroblasts or lymphocytes, both used as negative control. Moreover, immunofluorescence images and confocal analyses revealed staining of MSC by aptamers localized in the surfacemembrane of these cells. The results also showed internal staining of human monocytes by our investigated aptamers. A non-specific control aptamer (CNTR APT) obtained from the random pool was then utilized to compare the specificity of the aptamers bound to the analyzed non-apoptotic cells, showing no staining for MSC. However, 40% of the monocytes bound to the CNTR APT. Normalized data based on the cells bound to candidate aptamers compared to those bound to the CNTR APT, revealed a 10 to 16-fold higher binding rate for MSC against 2-fold for monocytes. Despite its low specificity, monocyte-aptamer binding occurs probably due to the expression of shared markers with MSC, since monocytes are derived from hematopoietic stem cells and are important for the immune system ability to internalize/phagocyte external molecules. Given that, we performed a pull-down assay followed by mass spectrometry analysis to detect which MSC-specific protein or other target epitope not coexpressed by monocytes or the CNTR APT would bind to the candidate aptamer. Distinguishing between MSC and monocyte epitopes is important, as both cells are involved in immunomodulatory effects after MSC transplantations. ADAM17 was found to be a target of the APT10, emerging as a possible biomarker of MSC, since its involvement in the inhibition of the TGF signaling cascade, which is responsible for the differentiation of MSC. Thus, MSC with a higher stemness profile should overexpress the protein ADAM17, which presents a catalytic site with affinity to APT10. Another target of Apt 10 is VAMP3, belonging to a transmembrane protein complex that is involved in endocytosis and exocytosis processes during immune and inflammatory responses. Overall, proteins identified as targets of APT10 may be cell surface MSC biomarkers, with importance for MSC-based cell and immune therapies

Células tronco são células indiferenciadas que podem ser distinguidas de outros tipos celulares por meio da habilidade de se auto renovarem e de se diferenciarem em novos tipos celulares. Células tronco mesenquimais (MSC) são células tronco adultas encontradas em diferentes tecidos como tecido adiposo, polpa de dente e cordão umbilical. Estas células podem se autodividir em células idênticas ou se diferenciarem em células de origem mesodermal. Estas células têm sido estudadas em novas aplicações que envolvem terapia regenerativas. Embora resultados encorajadores tenham sido demonstrados, terapias que utilizam MSC ainda encontram uma grande barreira: a dificuldade no isolamento destas células a partir de um ambiente heterogêneo. MSC são caracterizadas por populações positivas em ensaios de imunomarcação para os epítopos membranares CD29, CD73, CD90 e CD105, presentes também em outros tipos celulares. Assim, o presente trabalho tem o objetivo de identificar novos biomarcadores de MSC de origem humana, utilizando aptâmeros de DNA produzidos pela técnica SELEX (Systematic Evolution of Ligands by EXponential Enrichment) como ferramenta. Nossos resultados mostraram que MSC de diferentes origens ligam-se a aptâmeros (oligonucleotídeos de DNA ou RNA que atuam como ligantes específicos de alvos moleculares) de DNA candidatos que atuam no isolamento de MSC por meio da técnica FACS de separação celular, promovendo uma maior indução de diferenciação em células específicas (condrócitos, osteócitos e adipócitos) comparada com a população total de MSC. Análises de citometria de fluxo mostraram que os aptâmeros candidatos se ligam a 50% das MSC de polpa de dente e não apresentam taxa de ligação significante para fibroblastos e linfócitos de origem humana - utilizados como controles negativo. Além domais, imagens de imunofluorescência e confocal mostraram ligação na superfície da membrana de MSC e a marcação interna de monócitos a estes aptâmeros. Portanto, um aptâmero controle (CNTR APT) foi utilizado para comparar a especificidade dos aptâmeros ligados a células viáveis, mostrando a não ligação deste aptâmero a MSC. Porém, 40% da população de monócitos ligou-se ao CNTR APT. Uma normalização baseada na comparação entre as taxas de ligação entre células ligadas com aptâmeros candidatos e o aptâmero controle gerou uma taxa de especificidade entre 10-16 vezes maior para MSC contra 2,5 vezes para os monócitos. Deste modo, embora os resultados tenham mostrado uma taxa de ligação entre monócitos e aptâmeros, as MSC ligadas aos aptâmeros candidatos possuem uma maior taxa de especificidade devido a uma maior presença de antígenos que são expressos em ambas as células. Um ensaio de Pull Down seguido de espectrometria de massas foi utilizado para a identificação de biomarcadores que se ligariam aos aptâmeros candidatos, e que não seriam co-expressos por monócitos e por antígenos ligados ao aptâmero controle. Deste modo, a proteína ADAM17 foi identificada nas amostras de APT10 ligadas às MSC. Tal proteína está relacionada à inibição de uma cascata de sinalização da família de proteínas TGF, responsável pela diferenciação de MSC. Assim, MSC com maior potencial tronco deveriam expressar ADAM17 em maior quantidade. Tal proteína apresenta um sítio catalítico que demonstra interagir com o APT10, de acordo com predição Docking entre proteína e DNA. Foi identificada também, a proteína VAMP3, que pertence a um complexo proteico transmembranar responsável pelos processos de endocitose e exocitose, e que podem ter um papel importante na liberação de citocinas e outras moléculas relacionadas às respostas imune e inflamatórias. Deste modo, o APT10 identificou proteínas importantes que devem estar relacionas com a melhora de imunoterapias que utilizam MSC

Gene variants and serum levels of synaptic vesicle and presynaptic plasma membrane proteins in alcohol dependence and their relationship with impulsivity and temperament

ABSTRACT Background: Exocytosis-related gene variants have been suggested to be associated with externalizing behaviors. Objective: This study aimed to examine VAMP2 26 bp Ins/Del, synaptotagmin XI (Syt11) rs3820594 and 33-bp promoter, Syntaxin 1A (Syn-1A) rs1569061 and SNAP-25 rs1051312 and rs3746544 polymorphisms, their serum levels and their relationship with impulsivity, temperament in individuals with alcohol dependence (AD) and healthy controls (HC). Methods: The study included 107 individuals with AD and 104 HCs. Single-nucleotide polymorphisms (SNPs) were studied with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and serum levels with ELISA. Michigan Alcohol Screening Test (MAST), Barratt Impulsiveness Scale-11 (BIS-11) and Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire (TEMPS-A) were applied. Results: Syn-1A rs1569061 C allele polymorphism was significantly higher in AD group. Syn-1A rs1569061 C allele was associated with 1.5 times increased risk of AD. All serum levels were significantly higher in the HC group. There was a relationship between Syn-1A rs1569061 polymorphism and BIS-11 motor impulsiveness in the AD group; Syt11 rs3820594 polymorphism and BIS-11 total, TEMPS-A depressive, hyperthymia in the HC group. Discussion: In our study, gene variants and serum levels of synaptic vesicle and presynaptic plasma membrane proteins were related to AD, impulsivity and temperament.

Significance of Vesicle-Associated Membrane Protein 8 Expression in Predicting Survival in Breast Cancer / 한국유방암학회지

PURPOSE: Vesicle-associated membrane protein 8 (VAMP8) is a soluble N-ethylmaleimide-sensitive factor receptor protein that participates in autophagy by directly regulating autophagosome membrane fusion and has been reported to be involved in tumor progression. Nevertheless, the expression and prognostic value of VAMP8 in breast cancer (BC) remain unknown. This study aimed to evaluate the clinical significance and biological function of VAMP8 in BC. METHODS: A total of 112 BC samples and 30 normal mammary gland samples were collected. The expression of VAMP8 was assessed in both BC tissues and normal mammary gland tissues via a two-step immunohistochemical detection method. RESULTS: The expression of VAMP8 in BC tissues was significantly higher than that in normal breast tissues. Furthermore, increased VAMP8 expression was significantly correlated with tumor size (p=0.007), lymph node metastasis (p=0.024) and recurrence (p=0.001). Patients with high VAMP8 expression had significantly lower cumulative recurrence-free survival and overall survival (p < 0.001 for both) than patients with low VAMP8 expression. In multivariate logistic regression and Cox regression analyses, lymph node metastasis and VAMP8 expression were independent prognostic factors for BC. CONCLUSION: VAMP8 is significantly upregulated in human BC tissues and can thus be a practical and potentially effective surrogate marker for survival in BC patients.

Association of VAMP-2 and Syntaxin 1A Genes with Adult Attention Deficit Hyperactivity Disorder

OBJECTIVE: The etiology of attention deficit hyperactivity disorder (ADHD) has not been entirely clarified yet. Structural and metabolic differences at the prefrontal striatal cerebellary system and the interaction of gene and environment are the main factors that thought to play roles in the etiology. Genetic investigations are performed especially about the dopamine pathways and receptors. In this study; it was aimed to investigate the association of the synaptobrevin-2 (VAMP-2) gene Ins/Del polymorphism and syntaxin 1A gene intron 7 polymorphism, which take place in encoding presynaptic protein, with adult ADHD. METHODS: One hundred thirty-nine patients, having ADHD aging between 18 and 60 years and 106 healthy people as controls were included into the study. DNA samples were extracted from whole blood and genetic analysis were performed. RESULTS: A significant difference was determined between ADHD and VAMP-2 Ins/Del polymorphism and syntaxin 1A intron 7 polymorphism according to the control group. These polymorphisms were found not to be associated with subtypes of ADHD. CONCLUSION: It is supposed that synaptic protein genes together with dopaminergic genes might have roles in the etiology of ADHD.

Evaluación del tratamiento con VAMP más radioterapia a campos involucrados, en pacientes pediátricos mexicanos con estadio temprano de linfoma de Hodgkin / Evaluation of treatment with VAMP plus involved-field radiation in Mexican pediatric patients with early-stage Hodgkin lymphoma

Introducción. Objetivo: evaluar la supervivencia y toxicidad de pacientes con diagnóstico de linfoma de Hodgkin en etapa favorable tratados con quimioterapia con VAMP (vinblastina, doxorrubicina, metotrexate, prednisona) y bajas dosis de radioterapia a campos comprometidos. Métodos. Se incluyeron pacientes con etapas favorables tratados con 4 ciclos de VAMP (vinblastina 6 mg/m²sc, doxorrubicina 25 mg/m²sc, metotrexate 20 mg/m²sc y prednisona 40 mg/m²sc). Administrándose en los días 1 y 15; más radioterapia a campos comprometidos (21.6 Gy). La supervivencia se determinó por curvas de Kaplan-Meier y se ajustaron con la prueba de Cox. Resultados. Se incluyeron 17 pacientes, con media de edad de 7 años. Dos pacientes recayeron, uno a los 4 y otro a los 16 meses. La supervivencia global fue de 94.12%, con seguimiento de 66 meses (intervalo de confianza de 95% [IC95%]). La supervivencia libre de evento fue de 88.24% con seguimiento de 63 meses (IC 95%). Conclusiones. El uso de este esquema de quimioterapia y radioterapia (21.6 Gy) a campos comprometidos, tuvo una supervivencia global mayor. La toxicidad a mediano plazo por radioterapia fue elevada, por lo que se debe considerar la disminución de la dosis a 15 Gy para pacientes con respuesta completa.

Introduction. Purpose: To evaluate outcome and assess toxicity of patients with early-stage Hodgkin lymphoma treated with VAMP and low-dose involved-field radiation. Methods. Patients with clinical favorable stages Hodgkin lymphoma were treated with 4 cycles of VAMP (vinblastine 6 mg/m²sc, doxorrubicyn 25 mg/m²sc, methotrexate 20 mg/ m²sc, and prednisone 40 mg/m²sc) administrated on day 1 and day 15. And 21.6 Gy involvedfied radiation. The over-all survival was estimated using Kaplan-Meier and Cox methods. Results. 17 patients were included, the median age was 7 years. Two patients present progressive disease at 4 and 16 months respectively. The overall survival were 94.12% with follow-up of 66 months (IC 95%), the event-free survival were 88.24% with follow up of 63 months (IC 95%). Conclusions. The combined modality therapy with chemotherapy and involved-field radiation (21.6 Gy) shows a better overall survival. The radiation toxicity was elevated, for that reason we must try to reduce the dose of radiotherapy at 15 Gy in patients with complete response to treatment.

Alteration of Immunoreactivity for SNARE Proteins in the Rat Hippocampus after Middle Cerebral Artery Occlusion

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) proteins, composed of two presynaptic membrane proteins [synaptosomal-associated protein of 25 kDa (SNAP-25) and syntaxin] and a presynaptic vesicular protein [vesicle-associated membrane protein (VAMP) ], serve as a core of exocytotic fusion machinery, which can be affected by ischemia. Synaptic protein in core region, striatum and cortex has been shown to alter after focal ischemia, however, little is known in hippocampus. Hippocampus is remote from ischemic core, but it is one of the most vulnerable regions. Using immunohistochemistry, the present study was undertaken to investigate the alteration of expression of SNAP-25, syntaxin, and VAMP in the hippocampus of rats which were subjected to middle cerebral artery occlusion (MCAO) for 2h and allowed to reperfuse. At 2 weeks of reperfusion, the SNAP-25 and syntaxin immunoreactivity was increased in the stratum oriens of the CA1 and the stratum lucidum of the CA3 in the ipsilateral hippocampus. However, VAMP immunoreactivity didn't show significant change. These results demonstrate that the level of the presynatpic plasma membrane proteins (SNAP-25 and syntaxin) in the rat hippocampus is more sensitively affected by focal ischemia than that of the synaptic vesicle protein (VAMP).