2D versus 3D human induced pluripotent stem cell-derived cultures for neurodegenerative disease modelling

Neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS), affect millions of people every year and so far, there are no therapeutic cures available. Even though animal and histological models have been of great aid in understanding disease mechanisms and identifying possible therapeutic strategies, in order to find disease-modifying solutions there is still a critical need for systems that can provide more predictive and physiologically relevant results. One possible avenue is the development of patient-derived models, e.g. by reprogramming patient somatic cells into human induced pluripotent stem cells (hiPSCs), which can then be differentiated into any cell type for modelling. These systems contain key genetic information from the donors, and therefore have enormous potential as tools in the investigation of pathological mechanisms underlying disease phenotype, and progression, as well as in drug testing platforms. hiPSCs have been widely cultured in 2D systems, but in order to mimic human brain complexity, 3D models have been proposed as a more advanced alternative. This review will focus on the use of patient-derived hiPSCs to model AD, PD, HD and ALS. In brief, we will cover the available stem cells, types of 2D and 3D culture systems, existing models for neurodegenerative diseases, obstacles to model these diseases in vitro, and current perspectives in the field

Medical students’ creative projects on a third year pediatrics clerkship: a qualitative analysis of patient-centeredness and emotional connection

BACKGROUND: Increasingly, medical educators are incorporating reflective writing and original creative work into educational practices with the goals of stimulating student self-awareness, appreciation of multiple perspectives, and comfort with ambiguity and uncertainty. This study investigated students’ creative projects to assess the extent to which they adopted a patient/relationship-centered, emotionally connected position toward patients and families. METHODS: Over a 10 year period, students on a required third year pediatrics clerkship individually or in groups completed either a reflection or an education project using a creative medium. 520 projects (representing 595 students, 74.7 % of total eligible students) were qualitatively analyzed according to various thematic and emotion-based dimensions. RESULTS: The majority of projects were personal narrative essays and poetry. The largest number of project themes related to the importance of patient/relationship-centered medicine with patients. The next largest number of projects focused on health education of parents, patients, or classmates. In telling their stories, students were more likely to use a personal voice representing either their or the patient’s perspective than an objective, impersonal one. In terms of emotional tone, projects were more likely to be serious than humorous. The largest number of students’ emotions expressed an empathic tone. Students identified a large number and wide range of both negative and positive feelings in themselves and their patients. The majority of student emotions were positive, while the majority of patient and family emotions were negative. CONCLUSIONS: Students’ preference for patient-centered, relational themes, as well as their tendency to favor the first voice, empathic tone, and willingness to express a range of positive and negative emotions in presenting their projects, suggests that they valued emotional connection with patients and families during the pediatrics clerkship experience

Stem cell modeling of mitochondrial parkinsonism reveals key functions of OPA1

Objective Defective mitochondrial function due to OPA1 mutations causes primarily optic atrophy and less commonly neurodegenerative syndromes. The pathomechanism by which OPA1 mutations trigger diffuse loss of neurons in some but not all patients is unknown. Here we used a tractable iPSC-based model to capture the biology of OPA1 haploinsufficiency in cases presenting with classic eye disease versus syndromic parkinsonism. Methods iPSC were generated from two patients with OPA1 haploinsufficiency and two controls and differentiated into dopaminergic neurons. Metabolic profile was determined by extracellular flux analysis, respiratory complex levels using immunoblotting and complex I activity by a colorimetric assay. Mitochondria were examined by transmission electron microscopy. Mitochondrial DNA copy number and deletions were assayed using long range PCR. Mitochondrial membrane potential was measured by TMRM uptake and mitochondrial fragmentation was assessed by confocal microscopy. Exome sequencing was used to screen for pathogenic variants. Results OPA1 haploinsufficient iPSC differentiated into dopaminergic neurons and exhibited marked reduction in OPA1 protein levels. Loss of OPA1 caused a late defect in oxidative phosphorylation, reduced complex I levels and activity without a significant change in the ultrastructure of mitochondria. Loss of neurons in culture recapitulated dopaminergic degeneration in syndromic disease and correlated with mitochondrial fragmentation. Interpretation OPA1 levels maintain oxidative phosphorylation in iPSCderived neurons at least in part by regulating the stability of Complex I. Severity of OPA1 disease associates primarily with the extent of OPA1- mediated fusion, suggesting that activation of this mechanism or identification of its genetic modifiers may have therapeutic or prognostic value.</p