Fundacion Ciencia and Vida

Santiago, Chile

Fundacion Ciencia and Vida

Santiago, Chile
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Prado C.,Fundacion Ciencia and Vida | Prado C.,Andrés Bello University | Bernales S.,Fundacion Ciencia and Vida | Pacheco R.,Fundacion Ciencia and Vida | Pacheco R.,San Sebastián University
Endocrine, Metabolic and Immune Disorders - Drug Targets | Year: 2013

CD4+ T-cells are central players orchestrating antigen-specific immunity and tolerance. Importantly, dendritic cells (DCs) are responsible for priming T-cells and for promoting their differentiation from naïve T-cells into appropriate functional cells. Because of their fundamental roles in controlling immunity, activation and differentiation of DCs and CD4+ T-cells require tight regulatory mechanisms. Several studies have shown that dopamine, not only mediates interactions into the nervous system, but it can also contribute to the modulation of immunity. Here, we review the emerging role of this neurotransmitter as a regulator of DCs and CD4+ T-cells physiology and its consequent involvement, in the regulation of immune response. We specially focus the analysis in the role of dopamine receptor D5 expressed on DCs and CD4+ T-cells in the modulation of immunity. We also discuss how alterations in the dopamine-mediated regulation of immunity could contribute to the onset and development of immune-related disorders. © 2013 Bentham Science Publishers.


Steele J.W.,Mount Sinai School of Medicine | Steele J.W.,Rockefeller University | Ju S.,Brandeis University | Lachenmayer M.L.,Mount Sinai School of Medicine | And 26 more authors.
Molecular Psychiatry | Year: 2013

Latrepirdine (Dimebon; dimebolin) is a neuroactive compound that was associated with enhanced cognition, neuroprotection and neurogenesis in laboratory animals, and has entered phase II clinical trials for both Alzheimer's disease and Huntington's disease (HD). Based on recent indications that latrepirdine protects cells against cytotoxicity associated with expression of aggregatable neurodegeneration-related proteins, including Aβ42 and γ-synuclein, we sought to determine whether latrepirdine offers protection to Saccharomyces cerevisiae. We utilized separate and parallel expression in yeast of several neurodegeneration-related proteins, including α-synuclein (α-syn), the amyotrophic lateral sclerosis-associated genes TDP43 and FUS, and the HD-associated protein huntingtin with a 103 copy-polyglutamine expansion (HTT gene; htt-103Q). Latrepirdine effects on α-syn clearance and toxicity were also measured following treatment of SH-SY5Y cells or chronic treatment of wild-type mice. Latrepirdine only protected yeast against the cytotoxicity associated with α-syn, and this appeared to occur via induction of autophagy. We further report that latrepirdine stimulated the degradation of α-syn in differentiated SH-SY5Y neurons, and in mouse brain following chronic administration, in parallel with elevation of the levels of markers of autophagic activity. Ongoing experiments will determine the utility of latrepirdine to abrogate α-syn accumulation in transgenic mouse models of α-syn neuropathology. We propose that latrepirdine may represent a novel scaffold for discovery of robust pro-autophagic/anti-neurodegeneration compounds, which might yield clinical benefit for synucleinopathies including Parkinson's disease, Lewy body dementia, rapid eye movement (REM) sleep disorder and/or multiple system atrophy, following optimization of its pro-autophagic and pro-neurogenic activities. © 2013 Macmillan Publishers Limited.


Cochrane D.R.,Aurora University | Bernales S.,Medivation Inc. | Jacobsen B.M.,Aurora University | Cittelly D.M.,Aurora University | And 16 more authors.
Breast Cancer Research | Year: 2014

Introduction: The androgen receptor (AR) is widely expressed in breast cancers and has been proposed as a therapeutic target in estrogen receptor alpha (ER) negative breast cancers that retain AR. However, controversy exists regarding the role of AR, particularly in ER + tumors. Enzalutamide, an AR inhibitor that impairs nuclear localization of AR, was used to elucidate the role of AR in preclinical models of ER positive and negative breast cancer.Methods: We examined nuclear AR to ER protein ratios in primary breast cancers in relation to response to endocrine therapy. The effects of AR inhibition with enzalutamide were examined in vitro and in preclinical models of ER positive and negative breast cancer that express AR.Results: In a cohort of 192 women with ER + breast cancers, a high ratio of AR:ER (≥2.0) indicated an over four fold increased risk for failure while on tamoxifen (HR = 4.43). The AR:ER ratio had an independent effect on risk for failure above ER % staining alone. AR:ER ratio is also an independent predictor of disease-free survival (HR = 4.04, 95% CI: 1.68, 9.69; p = 0.002) and disease specific survival (HR = 2.75, 95% CI: 1.11, 6.86; p = 0.03). Both enzalutamide and bicalutamide inhibited 5-alpha-dihydrotestosterone (DHT)-mediated proliferation of breast cancer lines in vitro; however, enzalutamide uniquely inhibited estradiol (E2)-mediated proliferation of ER+/AR + breast cancer cells. In MCF7 xenografts (ER+/AR+) enzalutamide inhibited E2-driven tumor growth as effectively as tamoxifen by decreasing proliferation. Enzalutamide also inhibited DHT- driven tumor growth in both ER positive (MCF7) and negative (MDA-MB-453) xenografts, but did so by increasing apoptosis.Conclusions: AR to ER ratio may influence breast cancer response to traditional endocrine therapy. Enzalutamide elicits different effects on E2-mediated breast cancer cell proliferation than bicalutamide. This preclinical study supports the initiation of clinical studies evaluating enzalutamide for treatment of AR+ tumors regardless of ER status, since it blocks both androgen- and estrogen- mediated tumor growth. © 2014 Cochrane et al.; licensee BioMed Central Ltd.


Guerrero J.,Fundacion Ciencia and Vida | Alfaro I.E.,Fundacion Ciencia and Vida | Gomez F.,Fundacion Ciencia and Vida | Protter A.A.,Medivation Inc. | And 2 more authors.
Prostate | Year: 2013

BACKGROUND Enzalutamide (formerly MDV3100 and available commercially as Xtandi®), a novel androgen receptor (AR) signaling inhibitor, blocks the growth of castration-resistant prostate cancer (CRPC) in cellular model systems and was shown in a clinical study to increase survival in patients with metastatic CRPC. Enzalutamide inhibits multiple steps of AR signaling: binding of androgens to AR, AR nuclear translocation, and association of AR with DNA. Here, we investigate the effects of enzalutamide on AR signaling, AR-dependent gene expression and cell apoptosis. METHODS The expression of AR target gene prostate-specific antigen (PSA) was measured in LnCaP and C4-2 cells. AR nuclear translocation was assessed in HEK-293 cells stably transfected with AR-yellow fluorescent protein. The in vivo effects of enzalutamide were determined in a mouse xenograft model of CRPC. Differential gene expression in LNCaP cells was measured using Affymetrix human genome microarray technology. RESULTS We found that unlike bicalutamide, enzalutamide lacked AR agonistic activity at effective doses and did not induce PSA expression or AR nuclear translocation. Additionally, it is more effective than bicalutamide at inhibiting agonist-induced AR nuclear translocation. Enzalutamide induced the regression of tumor volume in a CRPC xenograft model and apoptosis in AR-over-expressing prostate cancer cells. Finally, gene expression profiling in LNCaP cells indicated that enzalutamide opposes agonist-induced changes in genes involved in processes such as cell adhesion, angiogenesis, and apoptosis. CONCLUSIONS These results indicate that enzalutamide efficiently inhibits AR signaling, and we suggest that its lack of AR agonist activity may be important for these effects. Copyright © 2013 Wiley Periodicals, Inc.


Rivera C.,Fundacion Ciencia and Vida | Gurard-Levin Z.A.,University Pierre and Marie Curie | Gurard-Levin Z.A.,French National Center for Scientific Research | Gurard-Levin Z.A.,Equipe Labellisee Ligue contre le Cancer | And 4 more authors.
Biochimica et Biophysica Acta - Gene Regulatory Mechanisms | Year: 2014

In eukaryotic organisms, the replication of the DNA sequence and its organization into chromatin are critical to maintain genome integrity. Chromatin components, such as histone variants and histone post-translational modifications, along with the higher-order chromatin structure, impact several DNA metabolic processes, including replication, transcription, and repair. In this review we focus on lysine methylation and the relationships between this histone mark and chromatin replication. We first describe studies implicating lysine methylation in regulating early steps in the replication process. We then discuss chromatin reassembly following replication fork passage, where the incorporation of a combination of newly synthesized histones and parental histones can impact the inheritance of lysine methylation marks on the daughter strands. Finally, we elaborate on how the inheritance of lysine methylation can impact maintenance of the chromatin landscape, using heterochromatin as a model chromatin domain, and we discuss the potential mechanisms involved in this process. This article is part of a Special Issue entitled: Methylation: A Multifaceted Modification - looking at transcription and beyond. © 2014 Elsevier B.V.


Gupta S.,Karolinska Institutet | Gupta S.,Swedish Institute for Communicable Disease Control | Braun M.,Karolinska University Hospital | Tischler N.D.,Fundacion Ciencia and Vida | And 9 more authors.
PLoS Pathogens | Year: 2013

Hantaviruses cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardio-pulmonary syndrome (HCPS; also called hantavirus pulmonary syndrome (HPS)), both human diseases with high case-fatality rates. Endothelial cells are the main targets for hantaviruses. An intriguing observation in patients with HFRS and HCPS is that on one hand the virus infection leads to strong activation of CD8 T cells and NK cells, on the other hand no obvious destruction of infected endothelial cells is observed. Here, we provide an explanation for this dichotomy by showing that hantavirus-infected endothelial cells are protected from cytotoxic lymphocyte-mediated induction of apoptosis. When dissecting potential mechanisms behind this phenomenon, we discovered that the hantavirus nucleocapsid protein inhibits the enzymatic activity of both granzyme B and caspase 3. This provides a tentative explanation for the hantavirus-mediated block of cytotoxic granule-mediated apoptosis-induction, and hence the protection of infected cells from cytotoxic lymphocytes. These findings may explain why infected endothelial cells in hantavirus-infected patients are not destroyed by the strong cytotoxic lymphocyte response. © 2013 Gupta et al.


Shmaryahu A.,Fundacion Ciencia and Vida | Carrasco M.,Fundacion Ciencia and Vida | Valenzuela P.D.T.,Fundacion Ciencia and Vida
Journal of Microbiology | Year: 2014

Recent studies have examined gene transfer from bacteria to humans that would result in vertical inheritance. Bacterial DNA appears to integrate into the human somatic genome through an RNA intermediate, and such integrations are detected more frequently in tumors than normal samples and in RNA than DNA samples. Also, vertebrate viruses encode products that interfere with the RNA silencing machinery, suggesting that RNA silencing may indeed be important for antiviral responses in vertebrates. RNA silencing in response to virus infection could be due to microRNAs encoded by either the virus or the host. We hypothesized that bacterial expression of RNA molecules with secondary structures is potentially able to generate miRNA molecules that can interact with the human host mRNA during bacterial infection. To test this hypothesis, we developed a pipelinebased bioinformatics approach to identify putative micro-RNAs derived from bacterial RNAs that may have the potential to regulate gene expression of the human host cell. Our results suggest that 68 bacterial RNAs predicted from 37 different bacterial genomes have predicted secondary structures potentially able to generate putative microRNAs that may interact with messenger RNAs of genes involved in 47 different human diseases. As an example, we examined the effect of transfecting three putative microRNAs into human embryonic kidney 293 (HEK293) cells. The results show that the bacterially derived microRNA sequence can significantly regulate the expression of the respective target human gene. We suggest that the study of these predicted microRNAs may yield important clues as to how the human host cell processes involved in human diseases like cancer, diabetes, rheumatoid arthritis, and others may respond to a particular bacterial environment. © 2014 The Microbiological Society of Korea and Springer-Verlag Berlin Heidelberg.


Baltierra F.,Fundacion Ciencia and Vida | Castillo M.,Andrés Bello University | Gamboa M.C.,Andrés Bello University | Rothhammer M.,Fundacion Ciencia and Vida | And 2 more authors.
Biochemical and Biophysical Research Communications | Year: 2013

Environmental stress factors such as salt, drought and heat are known to affect plant productivity. However, high salinity is spreading throughout the world, currently affecting more than 45 millionha. One of the mechanisms that allow plants to withstand salt stress consists on vacuolar sequestration of Na+, through a Na+/H+ antiporter. We isolated a new vacuolar Na+/H+ antiporter from Eucalyptus globulus from a cDNA library. The cDNA had a 1626bp open reading frame encoding a predicted protein of 542 amino acids with a deduced molecular weight of 59.1KDa. Phylogenetic and bioinformatic analyses indicated that EgNHX1 localized in the vacuole. To assess its role in Na+ exchange, we performed complementation studies using the Na+ sensitive yeast mutant strain Δnhx1. The results showed that EgNHX1 partially restored the salt sensitive phenotype of the yeast Δnhx1 strain. However, its overexpression in transgenic Arabidopsis confers tolerance in the presence of increasing NaCl concentrations while the wild type plants exhibited growth retardation. Expression profiles of Eucalyptus seedlings subjected to salt, drought, heat and ABA treatment were established. The results revealed that Egnhx1 was induced significantly only by drought. Together, these results suggest that the product of Egnhx1 from E. globulus is a functional vacuolar Na+/H+ antiporter. © 2012 Elsevier Inc.

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