Improving the quality of image generation in art with top-k training and cyclic generative methods.

The creation of artistic images through the use of Artificial Intelligence is an area that has been gaining interest in recent years. In particular, the ability of Neural Networks to separate and subsequently recombine the style of different images, generating a new artistic image with the desired style, has been a source of study and attraction for the academic and industrial community. This work addresses the challenge of generating artistic images that are framed in the style of pictorial Impressionism and, specifically, that imitate the style of one of its greatest exponents, the painter Claude Monet. After having analysed several theoretical approaches, the Cycle Generative Adversarial Networks are chosen as base model. From this point, a new training methodology which has not been applied to cyclical systems so far, the top-k approach, is implemented. The proposed system is characterised by using in each iteration of the training those k images that, in the previous iteration, have been able to better imitate the artist's style. To evaluate the performance of the proposed methods, the results obtained with both methodologies, basic and top-k, have been analysed from both a quantitative and qualitative perspective. Both evaluation methods demonstrate that the proposed top-k approach recreates the author's style in a more successful manner and, at the same time, also demonstrate the ability of Artificial Intelligence to generate something as creative as impressionist paintings.

Study of the Bcl-2 Interactome by BiFC Reveals Differences in the Activation Mechanism of Bax and Bak.

Evasion of apoptosis is one of the hallmarks of cancer cells. Proteins of the Bcl-2 family are key regulators of the intrinsic pathway of apoptosis, and alterations in some of these proteins are frequently found in cancer cells. Permeabilization of the outer mitochondrial membrane, regulated by pro- and antiapoptotic members of the Bcl-2 family of proteins, is essential for the release of apoptogenic factors leading to caspase activation, cell dismantlement, and death. Mitochondrial permeabilization depends on the formation of oligomers of the effector proteins Bax and Bak after an activation event mediated by BH3-only proteins and regulated by antiapoptotic members of the Bcl-2 family. In the present work, we have studied interactions between different members of the Bcl-2 family in living cells via the BiFC technique. Despite the limitations of this technique, present data suggest that native proteins of the Bcl-2 family acting inside living cells establish a complex network of interactions, which would fit nicely into "mixed" models recently proposed by others. Furthermore, our results point to differences in the regulation of Bax and Bak activation by proteins of the antiapoptotic and BH3-only subfamilies. We have also applied the BiFC technique to explore the different molecular models proposed for Bax and Bak oligomerization. Bax and Bak's mutants lacking the BH3 domain were still able to associate and give BiFC signals, suggesting the existence of alternative surfaces of interaction between two Bax or Bak molecules. These results agree with the widely accepted symmetric model for the dimerization of these proteins and also suggest that other regions, different from the α6 helix, could be involved in the oligomerization of BH3-in groove dimers.

Multiresistant Candida Endophthalmitis Treated with Intravitreal Caspofungin: A Case Report.

BACKGROUND: Candida endophthalmitis is a severe complication of candidemia. Currently, the recommended treatment of fungal endophthalmitis is a combination of intravitreal and systemic antifungal drugs, and in some cases vitrectomy is also required. Intravitreal therapies that are commonly used are amphotericin B and voriconazole, although recently the use of intravitreal caspofungin has been described in a few case reports. However, clinical experience with intravitreal caspofungin is still limited. CASE PRESENTATION: We report a case of bilateral candida tropicalis endophthalmitis, initially managed with repeated 100 µg/0.1 ml caspofungin intravitreal injections and posteriorly treated with pars plana vitrectomy in both eyes. CONCLUSIONS: Intravitreal caspofungin could be a safe intravitreal alternative to habitual antimycotic drugs in cases with resistant candida endophthalmitis.Abbreviations: Intensive Care Unit (ICU); Best-Corrected Visual Acuity (BCVA).

La importancia de la trazabilidad metrológica en la medicina diagnóstica / The importance of metrological traceability in diagnostic medicine

A los laboratorios clínicos alrededor del mundo se les exige constantemente entregar resultados cada vez más precisos y exactos, entendiendo la exactitud a la luz de los conceptos modernos, en donde se ha migrado a la teoría de la incertidumbre, que es en términos generales, una expresión numérica del grado de inexactitud o duda del resultado, asociada a la gran relevancia que ha cobrado la trazabilidad y su papel en la comparabilidad de los resultados con respecto a un material de referencia. La trazabilidad permite entonces, relacionar el resultado con referencias establecidas, dando la posibilidad de comparar los resultados en diferentes momentos y lugares, e incluso con distintos procedimientos de medición

Clinical laboratories around the world are constantly required to deliver increasingly precise and accurate results, understanding accuracy in the light of modern concepts, where it has migrated to the theory of uncertainty, which is in general terms, a numerical expression of the degree of inaccuracy or doubt of the result, associated with the great relevance that traceability has gained and its role in the comparability of results with respect to a reference material. Traceability allows then, to relate the result with established references, giving the possibility to compare results at different times and places, and even with different measurement procedures

Pasado, presente y futuro en el estudio de los nódulos tiroideos: papel de la citología y las pruebas moleculares / Past, present and future in the study of thyroid nodules: role of cytology and molecular tests

Los nódulos tiroideos siempre han sido considerados problemas comunes en la práctica clínica, y con el fin de estudiarlos se han buscado diferentes técnicas de aproximación y diagnóstico a lo largo de los años [1,2]. Esto ha contribuido al aumento en su incidencia, ya que a mayor número de estudios de imágenes realizados, aumenta la probabilidad de encontrarlos, puesto que tan solo el 50% son detectados por palpación al examen físico [3]. Es importante mencionar que a pesar de que solo el 5% de los nódulos tiroideos finalmente presentan un diagnóstico maligno y requieren manejo quirúrgico, hace algunos años se llevaban a cabo exámenes médicos diagnósticos y manejos quirúrgicos invasivos y exhaustivos que no eran prácticos, necesarios ni costo efectivos [4]. Fue solo hasta hace aproximadamente 40 años que se empezó a difundir el uso de la técnica diagnóstica desarrollada en 1950 por Söderstrom, Einhorn, Franzèn y Zajicek en el Hospital Radiumhelmet, de Estocolmo, Suecia, y considerada actualmente como la prueba de elección para la evaluación de nódulos tiroideos: la aspiración con aguja fina (ACAF), la cual se describe segura, precisa y rentable

Evaluación de nódulos tiroideos con interpretación citológica rápida en el sitio (ROSE) / Evaluation of thyroid nodules with Rapid On-Site Evaluation (ROSE)

La aspiración con aguja fina (ACAF) es una técnica ampliamente utilizada por su alta seguridad y fácil uso. Sin embargo, al usarse en conjunto con la evaluación rápida de la muestra en el sitio de la toma (ROSE, del inglés, Rapid On- Site Evaluation), disminuyen los tiempos necesarios para la evaluación y el diagnóstico, mejora la calidad de la muestra, disminuye el número de punciones por procedimiento y limita la necesidad de repetir la prueba, lo que hace que el uso combinado de ambas técnicas sea de gran utilidad y cada vez más solicitado en los servicios de imágenes diagnósticas y patología. ROSE, además, permite una clasificación adecuada del material recolectado para cultivos, estudios de citometría de flujo y pruebas moleculares. Particularmente, en los pacientes con nódulos tiroideos, la realización de ROSE durante el procedimiento de evaluación ecográfica y punción, puede garantizar que la muestra extraída sea suficiente y adecuada para el diagnóstico, y, así mismo, permite evaluar la necesidad de estudios complementarios de manera inmediata, brindando un diagnóstico rápido y preciso, disminuyendo los costos relacionados con la repetición del procedimiento y la morbilidad asociada a complicaciones por punciones múltiples

Fine needle aspiration (FNA) is a widely used technique due to its high safety and ease of use. However, when used in combination with Rapid On-Site Evaluation (ROSE), there is a reduction in the time required for evaluation and diagnosis, as well as an improvement in the sample quality, a reduction in the number of needle passes and the need to repeat the test, which makes the combined use of both techniques very useful and increasingly requested in the diagnostic imaging and pathology services. ROSE also allows a proper classification of the collected material for cultures, flow cytometry studies and molecular tests. Particularly in patients with thyroid nodules, the performance of ROSE during the ultrasound evaluation and biopsy procedure can guarantee that the sample extracted is sufficient and adequate for the diagnosis, and, likewise, an immediate evaluation for the need for complementary studies can be achieved, providing a fast and accurate diagnosis, reducing the costs related to repeating the procedure, and the morbidity associated with complications from multiple biopsies

Laboratorio molecular en virus del papiloma humano (VPH) y cáncer / Molecular laboratory in human papillomavirus (HPV) and cancer

No hace muchos años la aproximación hacia las neoplasias malignas en seres humanos tenía un enfoque diagnóstico principalmente basado en los hallazgos morfológicos, y aunque teníamos conocimiento de la oncogénesis por virus desde hace casi medio siglo, este conocimiento no se había logrado integrar al diagnóstico, prevención y manejo oncológico [1]. En la década de los cincuenta, el entendimiento de la historia natural del cáncer de cuello uterino, con tiempos largos de evolución, permitió la implementación de protocolos de tamización, que hasta hace menos de una década, estaban basados en citologías cervicovaginales seriadas y regulares [2,3], sin mucho protagonismo en los algoritmos diagnósticos de la detección de variantes de alto riesgo del virus del papiloma humano (VPHAR) [4]. A pesar de que las pruebas moleculares se encuentran aprobadas para uso clínico desde aproximadamente el año 2001 [5], solo hasta el 2014 en países como Estados Unidos, se incorporó la detección de genotipos de VPH-AR como prueba de tamización principal, que determina la necesidad de estudios adicionales para la detección temprana del cáncer cervicouterino

Virus del papiloma humano (VPH) y cáncer / Human papillomavirus (HPV) and cancer

Cada año, más de medio millón de mujeres en el mundo son diagnosticadas con cáncer cervical, usualmente asociado a la infección por virus del papiloma humano (VPH) de alto riesgo. Aunque la mayoría de las infecciones por VPH se resuelven dentro de un término menor de 2 años, algunos tipos virales, en particular el VPH16, pueden persistir por décadas y originar diferentes tipos de cáncer, siendo el cervical el más común. La historia natural de la infección por VPH de alto riesgo y el periodo prolongado en que ocurre su progresión, permite la prevención de la enfermedad. La infección por VPH de alto riesgo que evoluciona a cáncer incluye varios procesos como la integración del genoma viral, la división celular incontrolada, y la participación de cambios celulares y epigenéticos. La prueba de citología convencional que se viene practicando para la tamización hace más de 50 años continúa teniendo vigencia, especialmente en países de ingresos bajos y medios, pero está siendo reemplazada por otros métodos como las pruebas moleculares que detectan directamente la presencia del virus, con mayor efectividad como prueba de tamización. En 2014, el Ministerio de Salud y Protección Social de Colombia desarrolló una guía de práctica clínica para la detección y manejo de lesiones premalignas de cuello uterino, en la cual se recomienda la prueba de ADN-VPH para la tamización inicial en las mujeres mayores de 30 años. Hasta el momento se han encontrado resultados positivos con la implementación de la prueba, no obstante, se requieren estudios adicionales que confirmen estos hallazgos, dada su importancia en el control de la morbilidad y mortalidad asociadas a la infección

Each year, more than half a million women in the world are diagnosed with cervical cancer, usually associated with high-risk human papillomavirus (HPV) infection. Although most HPV infections resolve within 2 years, some viral types, particularly HPV16, can persist for decades and cause different types of cancer, being the cervical type the most common. The natural history of high-risk HPV infection and the prolonged period in which its progression occurs, allows for the prevention of the disease. High-risk HPV infection that progresses to cancer includes several processes such as viral genome integration, uncontrolled cell division, and the participation of cellular and epigenetic changes. The conventional Pap smear test that has been practiced as a screening method for more than 50 years continues to be used, especially in low- and middle-income countries, but it is being replaced by other methods such as molecular tests that directly detect the presence of the virus, with greater effectiveness as a screening test. In 2014, the Ministry of Health and Social Protection of Colombia developed a clinical practice guide for the detection and management of premalignant cervical lesions, in which the DNA-HPV test is recommended for initial screening in women over 30 years. So far, positive results have been found with the implementation of the test, however, additional studies are required to confirm these findings given its importance in controlling the morbidity and mortality associated with the infection

Detección y genotipificación del virus del papiloma humano de alto riesgo mediante PCR multiplex en tiempo real (RT-PCR VPH AR) / High risk human papillomavirus detection and genotyping by multiplex real time PCR (RT-PCR HR HPV)

Utilidad clínica de la prueba La relación causal entre el desarrollo de cáncer de cérvix y la infección con genotipos de alto riesgo (AR) del virus del papiloma humano (VPH), ha llevado al desarrollo de estrategias para su detección y caracterización genotípica, como una medida de prevención de este tipo de cáncer. Dado que la presencia del VPH no puede ser determinada mediante los hallazgos clínicos de la paciente, como tampoco en los hallazgos morfológicos en la citología ni en la detección de anticuerpos específicos contra el VPH (pruebas serológicas), su detección y genotipificación recaen en el uso de pruebas moleculares, las cuales en su mayoría están dirigidas a la detección del ADN de los genotipos de alto riesgo, usando la técnica de reacción en cadena de la polimerasa (PCR) convencional y en tiempo real (RT-PCR) [1]. La técnica de PCR permite la amplificación de regiones específicas del ADN del VPH en los genes L1, E6 y E7, los cuales, por sus variaciones en la secuencia, permiten la genotipificación del virus [2,3]. Las pruebas de detección de ADN y/o genotipificación del VPH son consideradas herramientas de tamización en cáncer de cérvix, que detectan la infección causada por VPH. Su aplicación está enfocada en la clasificación de anormalidades citológicas, monitoreo de infecciones persistentes, seguimiento postratamiento de lesiones intraepiteliales de alto grado y vigilancia epidemiológica en salud pública [4-6]. La utilización de la citología y las pruebas de detección de ADN del VPH, aumenta la sensibilidad de la tamización para la detección de cáncer de cérvix y reduce de manera significativa el riesgo de sufrir lesiones cervicales premalignas por un periodo de 5 años [2,7]

Mitochondrial AIF loss causes metabolic reprogramming, caspase-independent cell death blockade, embryonic lethality, and perinatal hydrocephalus.

OBJECTIVES: Apoptosis-Inducing Factor (AIF) is a protein involved in mitochondrial electron transport chain assembly/stability and programmed cell death. The relevant role of this protein is underlined because mutations altering mitochondrial AIF properties result in acute pediatric mitochondriopathies and tumor metastasis. By generating an original AIF-deficient mouse strain, this study attempted to analyze, in a single paradigm, the cellular and developmental metabolic consequences of AIF loss and the subsequent oxidative phosphorylation (OXPHOS) dysfunction. METHODS: We developed a novel AIF-deficient mouse strain and assessed, using molecular and cell biology approaches, the cellular, embryonic, and adult mice phenotypic alterations. Additionally, we conducted ex vivo assays with primary and immortalized AIF knockout mouse embryonic fibroblasts (MEFs) to establish the cell death characteristics and the metabolic adaptive responses provoked by the mitochondrial electron transport chain (ETC) breakdown. RESULTS: AIF deficiency destabilized mitochondrial ETC and provoked supercomplex disorganization, mitochondrial transmembrane potential loss, and high generation of mitochondrial reactive oxygen species (ROS). AIF-/Y MEFs counterbalanced these OXPHOS alterations by mitochondrial network reorganization and a metabolic reprogramming toward anaerobic glycolysis illustrated by the AMPK phosphorylation at Thr172, the overexpression of the glucose transporter GLUT-4, the subsequent enhancement of glucose uptake, and the anaerobic lactate generation. A late phenotype was characterized by the activation of P53/P21-mediated senescence. Notably, approximately 2% of AIF-/Y MEFs diminished both mitochondrial mass and ROS levels and spontaneously proliferated. These cycling AIF-/Y MEFs were resistant to caspase-independent cell death inducers. The AIF-deficient mouse strain was embryonic lethal between E11.5 and E13.5 with energy loss, proliferation arrest, and increased apoptotic levels. Contrary to AIF-/Y MEFs, the AIF KO embryos were unable to reprogram their metabolism toward anaerobic glycolysis. Heterozygous AIF+/- females displayed progressive bone marrow, thymus, and spleen cellular loss. In addition, approximately 10% of AIF+/- females developed perinatal hydrocephaly characterized by brain development impairment, meningeal fibrosis, and medullar hemorrhages; those mice died 5 weeks after birth. AIF+/- with hydrocephaly exhibited loss of ciliated epithelium in the ependymal layer. This phenotype was triggered by the ROS excess. Accordingly, it was possible to diminish the occurrence of hydrocephalus AIF+/- females by supplying dams and newborns with an antioxidant in drinking water. CONCLUSIONS: In a single knockout model and at 3 different levels (cell, embryo, and adult mice) we demonstrated that by controlling the mitochondrial OXPHOS/metabolism, AIF is a key factor regulating cell differentiation and fate. Additionally, by providing new insights into the pathological consequences of mitochondrial OXPHOS dysfunction, our new findings pave the way for novel pharmacological strategies.

Comparison of four pharmacological strategies aimed to prevent the lung inflammation and paraquat-induced alveolar damage.

OBJECTIVE: The aim of this study was to compare in vivo effect of five pharmacological options on inflammation and pulmonary fibrosis induced by paraquat. METHODS: 54 Wistar SPF rats were used. After 2 h post-intoxication with paraquat ion, groups of 9 animals were randomly assigned to (1) cyclophosphamide plus dexamethasone (2) low molecular weight heparin (3) unfractionated heparin (4) vitamin C every 24 h, (5) atorvastatin or (6) placebo with intraperitoneal saline. Lung inflammation, alveolar injury, hepatocyte damage, hepatic regeneration, acute tubular necrosis and kidney congestion were evaluated. RESULTS: In the control group 100% of animals presented moderate and severe lung inflammation, while in the groups with atorvastatin and intratracheal heparin this proportion was lower (55.5%; CI 26.6-81.3%) (p = 0.025). A lower degree of moderate or severe hepatic regeneration was evident in the treatment groups with atorvastatin (p = 0.009). In this study was demonstrated that statins and heparin might have a protective effect in the paraquat-induced destructive phase. More evidence is needed to evaluated of dose-response effects of these drugs before to study in clinical trials.

Application of Europium-Doped Very Small Iron Oxide Nanoparticles to Visualize Neuroinflammation with MRI and Fluorescence Microscopy.

Our recent studies demonstrated that electrostatically stabilized very small superparamagnetic iron oxide particles (VSOPs) are promising MRI probes for detecting various pathological aspects of autoimmunity in the central nervous system (CNS). However, investigation of the precise tissue and cellular distribution of VSOP has been technically limited due to the need to use iron detection methods for VSOP visualization. Therefore, we assessed here the utility of europium (Eu)-doped VSOP as an MRI tool for in vivo investigations in the animal model experimental autoimmune encephalomyelitis (EAE), and as a tool to investigate histopathological processes in the CNS using fluorescence microscopy. We demonstrated that Eu-VSOP display the same properties as VSOP in terms of revealing inflammation-mediated changes by binding to brain endothelium in vitro, and in terms of visualizing brain lesions in EAE in vivo. MRI examinations with Eu-VSOP confirm that at peak disease particles accumulated inside the choroid plexus, and in cerebellar and meningeal lesions. Importantly, Eu-VSOP-based MRI showed for the first time in a longitudinal setup that particles were absent from the choroid plexus in mice during remission of EAE, but accumulated again during subsequent relapse. Within the choroid plexus, Eu-VSOP were associated both with monocytes/macrophages present in the plexus stroma, and associated with epithelial cells. Using Eu-VSOP, we demonstrated for the first time the involvement of the choroid plexus in relapses. Thus, Eu-VSOP have the potential to reveal various aspects of choroid plexus involvement in neuroinflammation, including monocyte recruitment from the blood and alterations of the choroid plexus epithelium.

MR Elastography-Based Assessment of Matrix Remodeling at Lesion Sites Associated With Clinical Severity in a Model of Multiple Sclerosis.

Magnetic resonance imaging (MRI) with gadolinium based contrast agents (GBCA) is routinely used in the clinic to visualize lesions in multiple sclerosis (MS). Although GBCA reveal endothelial permeability, they fail to expose other aspects of lesion formation such as the magnitude of inflammation or tissue changes occurring at sites of blood-brain barrier (BBB) disruption. Moreover, evidence pointing to potential side effects of GBCA has been increasing. Thus, there is an urgent need to develop GBCA-independent imaging tools to monitor pathology in MS. Using MR-elastography (MRE), we previously demonstrated in both MS and the animal model experimental autoimmune encephalomyelitis (EAE) that inflammation was associated with a reduction of brain stiffness. Now, using the relapsing-remitting EAE model, we show that the cerebellum-a region with predominant inflammation in this model-is especially prone to loss of stiffness. We also demonstrate that, contrary to GBCA-MRI, reduction of brain stiffness correlates with clinical disability and is associated with enhanced expression of the extracellular matrix protein fibronectin (FN). Further, we show that FN is largely expressed by activated astrocytes at acute lesions, and reflects the magnitude of tissue remodeling at sites of BBB breakdown. Therefore, MRE could emerge as a safe tool suitable to monitor disease activity in MS.

Predictors of vision impairment in Multiple Sclerosis.

Visual impairment significantly alters the quality of life of people with Multiple Sclerosis (MS). The objective of this study was to identify predictors (independent variables) of visual outcomes, and to define their relationship with neurological disability and retinal atrophy when assessed by optical coherence tomography (OCT). We performed a cross-sectional analysis of 119 consecutive patients with MS, assessing vision using high contrast visual acuity (LogMar), 2.5% and 1.25% low contrast visual acuity (Sloan charts), and color vision (Hardy-Rand-Rittler plates). Quality of vision is a patient reported outcome based on an individual's unique perception of his or her vision and was assessed with the Visual Functioning Questionnaire-25 (VFQ-25) with the 10 neuro-ophthalmologic items. MS disability was assessed using the expanded disability status scale (EDSS), the MS functional composite (MSFC) and the brief repetitive battery-neuropsychology (BRB-N). Retinal atrophy was assessed using spectral domain OCT, measuring the thickness of the peripapillar retinal nerve fiber layer (pRNFL) and the volume of the ganglion cell plus inner plexiform layer (GCIPL). The vision of patients with MS was impaired, particularly in eyes with prior optic neuritis. Retinal atrophy (pRNFL and GCIPL) was closely associated with impaired low contrast vision and color vision, whereas the volume of the GCIPL showed a trend (p = 0.092) to be associated with quality of vision. Multiple regression analysis revealed that EDSS was an explanatory variable for high contrast vision after stepwise analysis, GCIPL volume for low contrast vision, and GCIPL volume and EDSS for color vision. The explanatory variables for quality of vision were high contrast vision and color vision. In summary, quality of vision in MS depends on the impairment of high contrast visual acuity and color vision due to the disease.

AIF loss deregulates hematopoiesis and reveals different adaptive metabolic responses in bone marrow cells and thymocytes.

Mitochondrial metabolism is a tightly regulated process that plays a central role throughout the lifespan of hematopoietic cells. Herein, we analyze the consequences of the mitochondrial oxidative phosphorylation (OXPHOS)/metabolism disorder associated with the cell-specific hematopoietic ablation of apoptosis-inducing factor (AIF). AIF-null (AIF-/Y ) mice developed pancytopenia that was associated with hypocellular bone marrow (BM) and thymus atrophy. Although myeloid cells were relatively spared, the B-cell and erythroid lineages were altered with increased frequencies of precursor B cells, pro-erythroblasts I, and basophilic erythroblasts II. T-cell populations were dramatically reduced with a thymopoiesis blockade at a double negative (DN) immature state, with DN1 accumulation and delayed DN2/DN3 and DN3/DN4 transitions. In BM cells, the OXPHOS/metabolism dysfunction provoked by the loss of AIF was counterbalanced by the augmentation of the mitochondrial biogenesis and a shift towards anaerobic glycolysis. Nevertheless, in a caspase-independent process, the resulting excess of reactive oxygen species compromised the viability of the hematopoietic stem cells (HSC) and progenitors. This led to the progressive exhaustion of the HSC pool, a reduced capacity of the BM progenitors to differentiate into colonies in methylcellulose assays, and the absence of cell-autonomous HSC repopulating potential in vivo. In contrast to BM cells, AIF-/Y thymocytes compensated for the OXPHOS breakdown by enhancing fatty acid ß-oxidation. By over-expressing CPT1, ACADL and PDK4, three key enzymes facilitating fatty acid ß-oxidation (e.g., palmitic acid assimilation), the AIF-/Y thymocytes retrieved the ATP levels of the AIF +/Y cells. As a consequence, it was possible to significantly reestablish AIF-/Y thymopoiesis in vivo by feeding the animals with a high-fat diet complemented with an antioxidant. Overall, our data reveal that the mitochondrial signals regulated by AIF are critical to hematopoietic decision-making. Emerging as a link between mitochondrial metabolism and hematopoietic cell fate, AIF-mediated OXPHOS regulation represents a target for the development of new immunomodulatory therapeutics.

Discovery of Enhancers of the Secretion of Leukemia Inhibitory Factor for the Treatment of Multiple Sclerosis.

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease that involves activation of T cells, microglia, and astrocytes. There is a clear unmet medical need for MS, as current therapies reduce the relapse rate, but are unable to prevent the neurological deterioration. Leukemia inhibitory factor (LIF) is a proinflammatory cytokine that can also positively modulate the immune response, by inducing the inhibition of myelin-reactive TH17 differentiation, and by promoting oligodendrocyte-mediated myelination. The aim of this project was to find central nervous system (CNS)-permeable and orally available small molecules that upregulate production of endogenous LIF. We describe here the development of a phenotypic assay and screening of 1.7 million compounds to identify LIF enhancers using U87 MG cells. Five chemically tractable series of compounds and a few singletons were selected for further progression. Some of them were also active in a different LIF-expressing cell line and in primary rat astrocytes. Although further studies would be required to deconvolute the targets involved in LIF induction and to confirm activity of hits in more disease-relevant assays, our results have demonstrated the potential of the phenotypic approach to identify specific and chemically tractable small molecules that trigger the production of LIF in relevant cell lines.

Bcl-2 family of proteins as drug targets for cancer chemotherapy: the long way of BH3 mimetics from bench to bedside.

Bcl-2 proteins are key determinants in the life-death balance. In recent years, proteins in this family have been identified as drug targets in the design of new anti-tumor therapies. Advances in the knowledge of the mechanism of action of anti-apoptotic and pro-apoptotic members of the Bcl-2 family have enabled the development of the so-called 'BH3 mimetics'. These compounds act by inhibiting anti-apoptotic proteins of the family, imitating the function of the BH3-only subset of pro-apoptotic members. Combinations of BH3-mimetics with anti-tumor drugs are being evaluated in both preclinical models and clinical trials. Recent advances in these approaches will be reviewed.

CD47 agonist peptides induce programmed cell death in refractory chronic lymphocytic leukemia B cells via PLCγ1 activation: evidence from mice and humans.

BACKGROUND: Chronic lymphocytic leukemia (CLL), the most common adulthood leukemia, is characterized by the accumulation of abnormal CD5+ B lymphocytes, which results in a progressive failure of the immune system. Despite intense research efforts, drug resistance remains a major cause of treatment failure in CLL, particularly in patients with dysfunctional TP53. The objective of our work was to identify potential approaches that might overcome CLL drug refractoriness by examining the pro-apoptotic potential of targeting the cell surface receptor CD47 with serum-stable agonist peptides. METHODS AND FINDINGS: In peripheral blood samples collected from 80 patients with CLL with positive and adverse prognostic features, we performed in vitro genetic and molecular analyses that demonstrate that the targeting of CD47 with peptides derived from the C-terminal domain of thrombospondin-1 efficiently kills the malignant CLL B cells, including those from high-risk individuals with a dysfunctional TP53 gene, while sparing the normal T and B lymphocytes from the CLL patients. Further studies reveal that the differential response of normal B lymphocytes, collected from 20 healthy donors, and leukemic B cells to CD47 peptide targeting results from the sustained activation in CLL B cells of phospholipase C gamma-1 (PLCγ1), a protein that is significantly over-expressed in CLL. Once phosphorylated at tyrosine 783, PLCγ1 enables a Ca2+-mediated, caspase-independent programmed cell death (PCD) pathway that is not down-modulated by the lymphocyte microenvironment. Accordingly, down-regulation of PLCγ1 or pharmacological inhibition of PLCγ1 phosphorylation abolishes CD47-mediated killing. Additionally, in a CLL-xenograft model developed in NOD/scid gamma mice, we demonstrate that the injection of CD47 agonist peptides reduces tumor burden without inducing anemia or toxicity in blood, liver, or kidney. The limitations of our study are mainly linked to the affinity of the peptides targeting CD47, which might be improved to reach the standard requirements in drug development, and the lack of a CLL animal model that fully mimics the human disease. CONCLUSIONS: Our work provides substantial progress in (i) the development of serum-stable CD47 agonist peptides that are highly effective at inducing PCD in CLL, (ii) the understanding of the molecular events regulating a novel PCD pathway that overcomes CLL apoptotic avoidance, (iii) the identification of PLCγ1 as an over-expressed protein in CLL B cells, and (iv) the description of a novel peptide-based strategy against CLL.