Mechanism of the Notch signaling pathway in enhancing the efficacy of chemotherapy drugs in osteosarcoma / 中南大学学报(医学版)

Osteosarcoma is the most common malignant tumors of bone. Since 1970s, researchers had used chemotherapy drugs to treat osteosarcoma. However, multidrug resistance is a major adverse reaction that affects the efficacy of chemotherapy drugs, leading to the reduced survival rate of osteosarcoma patients. The Notch signaling pathway plays an important role in osteosarcoma proliferation, which affects tumor resistance by reducing intracellular drug accumulation, regulating epithelial-mesenchymal transition, dysregulating microRNA, disrupting the expression of apoptosis genes, and regulating tumor stem cells.

La vía de señalización Notch en el origen de algunas malformaciones congénitas / The Notch Signaling Pathway at the Origin of Some Congenital Malformations

La vía de señalización Notch desempeña un papel clave para regular el destino celular, crecimiento, proliferación y la muerte celular programada durante el desarrollo de organismos eucariotas. Esta vía está relacionada con una enorme diversidad de procesos del desarrollo y su disfunción está implicada en el origen de muchas malformaciones congénitas. Se realizó una revisión bibliográfica con el objetivo de actualizar la información sobre la vía de señalización Notch y su relación con el origen de diferentes malformaciones congénitas sensibles a la deficiencia materna de ácido fólico y otros micronutrientes. La literatura médica publicada en idiomas español e inglés se recopiló a través de buscadores como PubMed, Medline, Scielo, Lilacs y la biblioteca Cochrane en enero de 2018 usando palabras clave apropiadas. El conocimiento de esta vía de señalización podría ayudar a comprender mejor algunos aspectos de la morfogénesis, ya que, al actuar como un controlador maestro del destino celular, la proliferación, diferenciación y muerte celular programada, ofrece puntos específicos y susceptibles de intervención que posibilitan la prevención de determinadas malformaciones congénitas en el hombre(AU)

Notch signaling pathway plays a key role to regulate cell grow, fates, proliferation and programmed cell death in development of eukaryotic organisms. This pathway is related with an enormous diversity of developmental processes and its dysfunction is implicated in the origin of many congenital malformations. A review was performed to provide updated information on Notch signaling pathway involved in the origin of some congenital malformations related with maternal deficiency of folic acid and other micronutrients. Published medical literature in Spanish and English languages was retrieved from PubMed, Medline, Scielo, Lilacs and the Cochrane Library in January 2018, using appropriate key words. Knowledge about this signaling pathway could help to better understand some topics of morphogenesis, since by acting as a master controller of cell fate, proliferation, differentiation and programmed cell death, it offers susceptible and specific points which make possible to prevent some human congenital malformations(AU)

The balance between GMD and OFUT1 regulates Notch signaling pathway activity by modulating Notch stability

The Notch signaling pathway plays an important role in development and physiology. In Drosophila, Notch is activated by its Delta or Serrate ligands, depending in part on the sugar modifications present in its extracellular domain. O-fucosyltransferase-1 (OFUT1) performs the first glycosylation step in this process, O-fucosylating various EGF repeats at the Notch extracellular domain. Besides its O-fucosyltransferase activity, OFUT1 also behaves as a chaperone during Notch synthesis and is able to down regulate Notch by enhancing its endocytosis and degradation. We have reevaluated the roles that O-fucosylation and the synthesis of GDP-fucose play in the regulation of Notch protein stability. Using mutants and the UAS/Gal4 system, we modified in developing tissues the amount of GDP-mannose-deshydratase (GMD), the first enzyme in the synthesis of GDP-fucose. Our results show that GMD activity, and likely the levels of GDP-fucose and O-fucosylation, are essential to stabilize the Notch protein. Notch degradation observed under low GMD expression is absolutely dependent on OFUT1 and this is also observed in Notch Abruptex mutants, which have mutations in some potential O-fucosylated EGF domains. We propose that the GDP-fucose/OFUT1 balance determines the ability of OFUT1 to endocytose and degrade Notch in a manner that is independent of the residues affected by Abruptex mutations in Notch EGF domains.

Brain Tumor Stem Cells as Therapeutic Targets in Models of Glioma

At this time, brain tumor stem cells remain a controversial hypothesis while malignant brain tumors continue to present a dire prognosis of severe morbidity and mortality. Yet, brain tumor stem cells may represent an essential cellular target for glioma therapy as they are postulated to be the tumorigenic cells responsible for recurrence. Targeting oncogenic pathways that are essential to the survival and growth of brain tumor stem cells represents a promising area for developing therapeutics. However, due to the multiple oncogenic pathways involved in glioma, it is necessary to determine which pathways are the essential targets for therapy. Furthermore, research still needs to comprehend the morphogenic processes of cell populations involved in tumor formation. Here, we review research and discuss perspectives on models of glioma in order to delineate the current issues in defining brain tumor stem cells as therapeutic targets in models of glioma.

CADASIL: comunicación de una familiauruguaya con definición clínica, imagenológica, anatomopatológica y genética molecular / Clinical, imagenology, anatomopathological and molecular genetics results for the diagnosis of CADASIL in a Uruguayan family

Introducción: el síndrome CADASIL (Cerebral Dominant Arteriopathy with Subcortical Infarcts and Leukoencephlopathy) es una microangiopatía no amiloidea, no ateromatosa que se transmite en forma autosómica dominante y cuyas principales manifestaciones clínicasocurren a nivel cerebral. Su diagnóstico requiere criterios clínicos, imagenológicos y genéticos moleculares.Material y método: se estudiaron anatomopatológicamente mediante biopsia de piel y músculo y estudio genético molecular a tres integrantes de una familia con diagnóstico de CADASIL.Resultados: los exámenes clínicos, paraclínicos, neurológicos y ultraestructural de biopsia de piel mostraron resultados consistentes con CADASIL. La secuenciación de exones 2,3,4,5,8,11,20,23 del gene NOTCH3 detectó una mutación en forma heterocigota en el exón 5 no descripta en la literatura.Conclusiones: destacamos la importancia del diagnóstico precoz de esta enfermedad y la definición molecular que permite el asesoramiento genético a todos los integrantes de lafamilia y, eventualmente, el diagnóstico prenatal.

Introduction: CADASIL syndrome (Cerebral Dominant Arteriopathy with Subcortical Infarcts and Leukoencephlopathy),the most common form of hereditary stroke disorder is a nonamyloid, non-atheromatous microangiopathy. Main clinical features are found in the brain. The disease may be diagnosed by clinical findings, images and geneticmolecular criteria.Methods: an anatomopathological analysis through a skin and muscle biopsy and molecular study was performed on three members of the same family diagnosed with CADASIL.Results: clinical, paraclinical, neurological and ultrastructuralskin biopsy study's findings were consistent with CADASIL. NOTCH3 sequence exonal analysis(2,3,4,5,8,11,20,23) suggested heterocigotic mutations in exon 5, not previously described in literature.Conclusions: we stress the importance of early diagnosis of this disease and the molecular definition that enablesgenetic counselling to all members of the family and, potentially, prenatal diagnosis of the disease.

Introdução: a síndrome CADASIL (Cerebral Dominant Arteriopathy with Subcortical Infarcts and Leukoencephlopathy)é uma microangiopatia não amiloidea, não ateromatosa que se transmite de maneira autossômica dominantecujas principais manifestações clinicas são observadas no cérebro. Para seu diagnóstico é necessário realizarprovas clínicas, imagenológicas e de genética molecular.Material e método: foram realizados exames de anatomia patológica e de genética molecular em biopsias depele e músculo a três integrantes de uma família com diagnóstico de CADASIL.Resultados: os exames clínicos, paraclínicos, neurológicos e ultra-estrutural da biopsia de pele mostraram resultados consistentes com CADASIL. A seqüenciação dos exons 2,3,4,5,8,11,20,23 do gene NOTCH3 detectou uma mutação em forma heterozigótica no exon 5 não descritana literatura.Conclusões: destacamos a importância do diagnóstico precoce desta doença e a definição molecular que permite o assessoramento genético a todos os integrantes da família e, eventualmente, o diagnóstico pré-natal.

Microarray for Genes Associated with Signal Transduction in Diabetic OLETF Keratocytes

PURPOSE: The purpose of this study was to identify differences in signal transduction gene expression between normal and diabetic keratocytes stimulated with interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha). METHODS: Normal and diabetic keratocytes were primarily cultured and treated with 20 ng/ml IL-1alpha and TNF-alpha for 6 h. cDNA was hybridized to an oligonucleotide microarray. Genes identified by the microarray were further evaluated by real-time PCR. RESULTS: Diabetic keratocytes over-expressed components of the MAPK and Notch pathways, and under-expressed components of the insulin, calcium, and TGF-beta pathways. Cytokine treated diabetic keratocytes differentially expressed components of the TGF-beta and MAPK pathways. After IL-1alpha and TNF-alpha treatment, nine genes were under-expressed, falling in the insulin, TGF-beta, and Toll-like receptor pathways. Real-time PCR showed a significant decrease in the IL-6 and TGF-beta2 genes and a significant increase in the Ppm1a gene. CONCLUSIONS: There were some differences in gene expression between normal and diabetic keratocytes related to signal transduction pathways, such as the insulin, MAPK, calcium, and TGF-beta pathways. In addition, IL-1alpha and TNF-alpha stimulating the insulin, TGF-beta, and Toll-like receptor signaling pathways may have different effects in diabetic keratocytes.

Temporal expression of Notch in preterm rat lungs exposed to hyperoxia / 华中科技大学学报（医学）（英德文版）

To explore the mechanism of Notch in hyperoxia-induced preterm rat lung injury, 2-days-old preterm SD rats were randomized into control and hyperoxia group (FiO2 > or = 0.85). On day 1, 7, 14 and 21, 8 rat pups of each time point were used to assess histopathological changes of lung with HE staining and to evaluate the expression of Notch1 and Notch3 with immunohistochemistry. Notch1, Notch3, Aquaprin5 (AQP5) and surfactant protein C (SP-C) mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). The results showed that the lung injury in the hyperoxia group was characterized by retarded lung alveolization and differentiation of alveolar epithelial type II cells (AEC II). Positive staining of Notch1 in hyperoxia group was weaker than controls at every time point (except for day 7), while positive staining of Notch3 was much stronger (P < 0.05, P < 0.01). Notch1, Notch3 mRNA level showed similar change as protein level. AQP5, SP-C mRNA decreased significantly as compared with that of the controls (P < 0.01). We are led to conclude that hyperoxia results in abnormal expression of Notch, which is likely to contribute to the pathogenesis of lung injury through regulating proliferation and transdifferentiation of alveolar epithelial cells.

Relationship between Notch receptors and hyperoxia-induced lung injury in newborn rats / 华中科技大学学报（医学）（英德文版）

To investigate role of Notch1 - 3 in hyperoxia-induced lung injury in newborn rat exposed to 85% O2, SD rat litters born on the 22th day were randomly divided into two groups: room air group and hyperoxia group. The animals were sacrificed 1, 4, 7, 10, 14 and 21 days after continued exposure to oxygen (n = 40, oxygen > 0.85) or room air (n = 40). 6 rats each group were used to assess lung histological changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from frozen lung tissues. Notch mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that 7, 14 and 21 days after O2 exposure, hyperoxia group showed lung injury characterized by pulmonary edema, hemorrhage and lung development arrest. Positive staining for Notch1, Notch 2 in hyperoxia group was much lower than those in room air group at all time points (P 0.05). Immunostained cells were typically airways epithelia, alveolar epithelial and inflammatory cells, and fibroblasts in hyperoxia group (P < 0.01). Notch mRNA levels showed similar change as protein level (P < 0.01). It is concluded that the prolonged exposure to 85% O2 resulted in abnormal expression of Notch receptors, which might contribute to the pathogenesis of hyperoxia-induced lung injury in newborn rats. The decreased inhibition of Notch1 might be one of the protective reaction and major mechanisms for proliferation/differentiation of type II alveolar epithelial cells. The up-regulation of Notch3 activity might result in the lung development arrest of the newborn rats.