In vitro modeling of dysfunctional glial cells in neurodegenerative diseases using human pluripotent stem cells

Most neurodegenerative diseases are characterized by a complex and mostly still unresolved pathology. This fact, together with the lack of reliable models, have precluded the development of effective therapies counteracting the disease progression. In the past few years, several studies have evidenced that lack of proper functionality of glial cells (astrocytes, microglia and oligodendrocytes) has a key role in the pathology of several neurodegenerative conditions including Alzheimer´s disease, amyotrophic lateral sclerosis and multiple sclerosis among others. However, this glial dysfunction is poorly modelled by available animal models, and we hypothesize that patientderived cells can serve as a better platform where to study this glial dysfunction. In this sense, human pluripotent stem cells (hPSCs) has revolutionized the field allowing the generation of disease-relevant neural cell types that can be used for disease modelling, drug screening and, possibly, cell transplantation purposes. In the case of the generation of oligodendrocytes (OLs) from hPSCs, we have developed a fast and robust protocol to generate surface antigen O4-positive (O4+) and myelin basic protein-positive OLs from hPSCs in only 22 days, including from patients with multiple sclerosis or amyotrophic lateral sclerosis. The generated cells resemble primary human OLs at the transcriptome level and can myelinate neurons in vivo. Using in vitro OLneuron co-cultures, effective myelination of neurons can also be demonstrated. This platform is being translated as well to the generation of the other glial cell types, allowing the derivation of patient-specific glial cells where to model disease-specific dysfunction. This methodology can be used for elucidating pathogenic pathways associated with neurodegeneration and to identify therapeutic targets susceptible of drug modulation, contributing to the development of novel and effective drugs for these devastating disorders.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Supported by PI18/01557 (to AG) and P18/1556 (to JV) grants from ISCiii of Spain co-financed by FEDER funds from European Union, and PI-0276-2018 grant (to JAGL) from Consejeria de Salud of Junta de Andalucia. JAGL held a postdoctoral contract from the I Research Plan Propio of the University of Malaga. CV and KE were supported by IWT-SBO-150031-iPSCAF and the Thierry Lathran Foundation grant – ALS-OL, and KN by FWO1166518

Propylthioiracil induced ANCA-associated vasculitis in a 14 year-old girl

Background: Antineutrophil cytoplasmic antibodies (ANCAs) are the serologic hallmark of ANCA-associated primary small-vessel vasculitides (AAVs), but these antibodies have also been described in other autoimmune diseases such as inflammatory bowel diseases. Furthermore, different drugs are linked to the induction of ANCA, including propylthiouracil (PTU). However progression into clinical overt vasculitis is less common. Case-diagnosis/treatment: We describe the case of a young girl with Graves' disease presenting with fatigue, fever, episcleritis and arthritis. The unexpected double myeloperoxidase/proteinase 3-ANCA positivity triggered a multidisciplinary diagnostic work-up and resulted in the diagnosis of a clinically overt PTU-induced AAV. After PTU-withdrawal and treatment with high-dose corticosteroids, a favorable clinical and biochemical evolution was obtained. Conclusions: The use of PTU in the management of hyperthyroidism is not considered first-line treatment in Europe and is even less commonly used in children. Nevertheless, pediatricians should be aware of the possibility of PTU-induced AAV, especially in the presence of multiple ANCA reactivities. Therefore, the use of this drug should be weighed carefully in children

Characterisation and classification of oligometastatic disease : a European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus recommendation

Oligometastatic disease has been proposed as an intermediate state between localised and systemically metastasised disease. In the absence of randomised phase 3 trials, early clinical studies show improved survival when radical local therapy is added to standard systemic therapy for oligometastatic disease. However, since no biomarker for the identification of patients with true oligometastatic disease is clinically available, the diagnosis of oligometastatic disease is based solely on imaging findings. A small number of metastases on imaging could represent different clinical scenarios, which are associated with different prognoses and might require different treatment strategies. 20 international experts including 19 members of the European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer OligoCare project developed a comprehensive system for characterisation and classification of oligometastatic disease. We first did a systematic review of the literature to identify inclusion and exclusion criteria of prospective interventional oligometastatic disease clinical trials. Next, we used a Delphi consensus process to select a total of 17 oligometastatic disease characterisation factors that should be assessed in all patients treated with radical local therapy for oligometastatic disease, both within and outside of clinical trials. Using a second round of the Delphi method, we established a decision tree for oligometastatic disease classification together with a nomenclature. We agreed oligometastatic disease as the overall umbrella term. A history of polymetastatic disease before diagnosis of oligometastatic disease was used as the criterion to differentiate between induced oligometastatic disease (previous history of polymetastatic disease) and genuine oligometastatic disease (no history of polymetastatic disease). We further subclassified genuine oligometastatic disease into repeat oligometastatic disease (previous history of oligometastatic disease) and de-novo oligometastatic disease (first time diagnosis of oligometastatic disease). In de-novo oligometastatic disease, we differentiated between synchronous and metachronous oligometastatic disease. We did a final subclassification into oligorecurrence, oligoprogression, and oligopersistence, considering whether oligometastatic disease is diagnosed during a treatment-free interval or during active systemic therapy and whether or not an oligometastatic lesion is progressing on current imaging. This oligometastatic disease classification and nomenclature needs to be prospectively evaluated by the OligoCare study

The human somatostatin receptor type 2 as an imaging and suicide reporter gene for pluripotent stem cell-derived therapy of myocardial infarction

Rationale: Pluripotent stem cells (PSCs) are being investigated as a cell source for regenerative medicine since they provide an infinitive pool of cells that are able to differentiate towards every cell type of the body. One possible therapeutic application involves the use of these cells to treat myocardial infarction (MI), a condition where billions of cardiomyocytes (CMs) are lost. Although several protocols have been developed to differentiate PSCs towards CMs, none of these provide a completely pure population, thereby still posing a risk for neoplastic teratoma formation. Therefore, we developed a strategy to (i) monitor cell behavior noninvasively via site-specific integration of firefly luciferase (Fluc) and the human positron emission tomography (PET) imaging reporter genes, sodium iodide symporter (hNIS) and somatostatin receptor type 2 (hSSTr2), and (ii) perform hSSTr2-mediated suicide gene therapy via the clinically used radiopharmacon 177Lu-DOTATATE. Methods: Human embryonic stem cells (ESCs) were gene-edited via zinc finger nucleases to express Fluc and either hNIS or hSSTr2 in the safe harbor locus, adeno-associated virus integration site 1. Firstly, these cells were exposed to 4.8 MBq 177Lu-DOTATATE in vitro and cell survival was monitored via bioluminescence imaging (BLI). Afterwards, hNIS+ and hSSTr2+ ESCs were transplanted subcutaneously and teratomas were allowed to form. At day 59, baseline 124I and 68Ga-DOTATATE PET and BLI scans were performed. The day after, animals received either saline or 55 MBq 177Lu-DOTATATE. Weekly BLI scans were performed, accompanied by 124I and 68Ga-DOTATATE PET scans at days 87 and 88, respectively. Finally, hSSTr2+ ESCs were differentiated towards CMs and transplanted intramyocardially in the border zone of an infarct that was induced by left anterior descending coronary artery ligation. After transplantation, the animals were monitored via BLI and PET, while global cardiac function was evaluated using cardiac magnetic resonance imaging. Results: Teratoma growth of both hNIS+ and hSSTr2+ ESCs could be followed noninvasively over time by both PET and BLI. After 177Lu-DOTATATE administration, successful cell killing of the hSSTr2+ ESCs was achieved both in vitro and in vivo, indicated by reductions in total tracer lesion uptake, BLI signal and teratoma volume. As undifferentiated hSSTr2+ ESCs are not therapeutically relevant, they were differentiated towards CMs and injected in immune-deficient mice with a MI. Long-term cell survival could be monitored without uncontrolled cell proliferation. However, no improvement in the left ventricular ejection fraction was observed.Conclusion: We developed isogenic hSSTr2-expressing ESCs that allow noninvasive cell monitoring in the context of PSC-derived regenerative therapy. Furthermore, we are the first to use the hSSTr2 not only as an imaging reporter gene, but also as a suicide mechanism for radionuclide therapy in the setting of PSC-derived cell treatment

The SEURAT-1 Approach towards Animal Free Human Safety Assessment

SEURAT-1 is a European public-private research consortium that is working towards animal-free testing of chemical compounds and the highest level of consumer protection. A research strategy was formulated based on the guiding principle to adopt a toxicological mode-of-action framework to describe how any substance may adversely affect human health. The proof of the initiative will be in demonstrating the applicability of the concepts on which SEURAT-1 is built on three levels: (i) Theoretical prototypes for adverse outcome pathways are formulated based on knowledge already available in the scientific literature on investigating the toxicological modes-of-action leading to adverse outcomes (addressing mainly liver toxicity); (ii) adverse outcome pathway descriptions are used as a guide for the formulation of case studies to further elucidate the theoretical model and to develop integrated testing strategies for the prediction of certain toxicological effects (i.e., those related to the adverse outcome pathway descriptions); (iii) further case studies target the application of knowledge gained within SEURAT-1 in the context of safety assessment. The ultimate goal would be to perform ab initio predictions based on a complete understanding of toxicological mechanisms. In the near-term, it is more realistic that data from innovative testing methods will support read-across arguments. Both scenarios are addressed with case studies for improved safety assessment. A conceptual framework for a rational integrated assessment strategy emerged from designing the case studies and is discussed in the context of international developments focusing on alternative approaches for evaluating chemicals using the new 21st century tools for toxicity testing

Plasticity and cardiovascular applications of multipotent adult progenitor cells

Cardiovascular disease is the leading cause of death worldwide, which has encouraged the search for new therapies that enable the treatment of patients in palliative and curative ways. In the past decade, the potential benefit of transplantation of cells that are able to substitute for the injured tissue has been studied with several cell populations, such as stem cells. Some of these cell populations, such as myoblasts and bone marrow cells, are already being used in clinical trials. The laboratory of CM Verfaillie has studied primitive progenitors, termed multipotent adult progenitor cells, which can be isolated from adult bone marrow. These cells can differentiate in vitro at the single-cell level into functional cells that belong to the three germ layers and contribute to most, if not all, somatic cell types after blastocyst injection. This remarkably broad differentiation potential makes this particular cell population a candidate for transplantation in tissues in need of regeneration. Here, we focus on the regenerative capacity of multipotent adult progenitor cells in several ischemic mouse models, such as acute and chronic myocardial infarction and limb ischemia