Maintenance of mitochondrial integrity in midbrain dopaminergic neurons governed by a conserved developmental transcription factor.

Progressive degeneration of dopaminergic (DA) neurons in the substantia nigra is a hallmark of Parkinson's disease (PD). Dysregulation of developmental transcription factors is implicated in dopaminergic neurodegeneration, but the underlying molecular mechanisms remain largely unknown. Drosophila Fer2 is a prime example of a developmental transcription factor required for the birth and maintenance of midbrain DA neurons. Using an approach combining ChIP-seq, RNA-seq, and genetic epistasis experiments with PD-linked genes, here we demonstrate that Fer2 controls a transcriptional network to maintain mitochondrial structure and function, and thus confers dopaminergic neuroprotection against genetic and oxidative insults. We further show that conditional ablation of Nato3, a mouse homolog of Fer2, in differentiated DA neurons causes mitochondrial abnormalities and locomotor impairments in aged mice. Our results reveal the essential and conserved role of Fer2 homologs in the mitochondrial maintenance of midbrain DA neurons, opening new perspectives for modeling and treating PD.

Application of Airy beam light sheet microscopy to examine early neurodevelopmental structures in 3D hiPSC-derived human cortical spheroids.

BACKGROUND: The inability to observe relevant biological processes in vivo significantly restricts human neurodevelopmental research. Advances in appropriate in vitro model systems, including patient-specific human brain organoids and human cortical spheroids (hCSs), offer a pragmatic solution to this issue. In particular, hCSs are an accessible method for generating homogenous organoids of dorsal telencephalic fate, which recapitulate key aspects of human corticogenesis, including the formation of neural rosettes-in vitro correlates of the neural tube. These neurogenic niches give rise to neural progenitors that subsequently differentiate into neurons. Studies differentiating induced pluripotent stem cells (hiPSCs) in 2D have linked atypical formation of neural rosettes with neurodevelopmental disorders such as autism spectrum conditions. Thus far, however, conventional methods of tissue preparation in this field limit the ability to image these structures in three-dimensions within intact hCS or other 3D preparations. To overcome this limitation, we have sought to optimise a methodological approach to process hCSs to maximise the utility of a novel Airy-beam light sheet microscope (ALSM) to acquire high resolution volumetric images of internal structures within hCS representative of early developmental time points. RESULTS: Conventional approaches to imaging hCS by confocal microscopy were limited in their ability to image effectively into intact spheroids. Conversely, volumetric acquisition by ALSM offered superior imaging through intact, non-clarified, in vitro tissues, in both speed and resolution when compared to conventional confocal imaging systems. Furthermore, optimised immunohistochemistry and optical clearing of hCSs afforded improved imaging at depth. This permitted visualization of the morphology of the inner lumen of neural rosettes. CONCLUSION: We present an optimized methodology that takes advantage of an ALSM system that can rapidly image intact 3D brain organoids at high resolution while retaining a large field of view. This imaging modality can be applied to both non-cleared and cleared in vitro human brain spheroids derived from hiPSCs for precise examination of their internal 3D structures. This process represents a rapid, highly efficient method to examine and quantify in 3D the formation of key structures required for the coordination of neurodevelopmental processes in both health and disease states. We posit that this approach would facilitate investigation of human neurodevelopmental processes in vitro.

Atypical Neurogenesis in Induced Pluripotent Stem Cells From Autistic Individuals.

BACKGROUND: Autism is a heterogeneous collection of disorders with a complex molecular underpinning. Evidence from postmortem brain studies have indicated that early prenatal development may be altered in autism. Induced pluripotent stem cells (iPSCs) generated from individuals with autism with macrocephaly also indicate prenatal development as a critical period for this condition. But little is known about early altered cellular events during prenatal stages in autism. METHODS: iPSCs were generated from 9 unrelated individuals with autism without macrocephaly and with heterogeneous genetic backgrounds, and 6 typically developing control individuals. iPSCs were differentiated toward either cortical or midbrain fates. Gene expression and high throughput cellular phenotyping was used to characterize iPSCs at different stages of differentiation. RESULTS: A subset of autism-iPSC cortical neurons were RNA-sequenced to reveal autism-specific signatures similar to postmortem brain studies, indicating a potential common biological mechanism. Autism-iPSCs differentiated toward a cortical fate displayed impairments in the ability to self-form into neural rosettes. In addition, autism-iPSCs demonstrated significant differences in rate of cell type assignment of cortical precursors and dorsal and ventral forebrain precursors. These cellular phenotypes occurred in the absence of alterations in cell proliferation during cortical differentiation, differing from previous studies. Acquisition of cell fate during midbrain differentiation was not different between control- and autism-iPSCs. CONCLUSIONS: Taken together, our data indicate that autism-iPSCs diverge from control-iPSCs at a cellular level during early stage of neurodevelopment. This suggests that unique developmental differences associated with autism may be established at early prenatal stages.

Regional analysis of age-related local bone loss in the spine of a healthy population using 3D voxel-based modeling.

Local variations in bone loss may be of great importance to individually predict osteoporotic fractures but are neglected by current densitometry techniques. The purpose of this study was to evaluate regional variations of normal bone loss at the spine among different age groups using voxel-based morphometry. Non-contrast MDCT scans of 16 patients under the age of 40 (mean age 26years) without spinal pathology were identified as a reference cohort, where each thoracolumbar vertebra was assessed individually. For comparison, 38 patients >40years were grouped by decades in 4 cohorts of 10 patients each, except the youngest, including 8 patients only. All spines were automatically detected, segmented and non-rigidly registered for spatially normalized vertebral bodies. Afterwards, statistical and T-score mapping was performed to highlight local density differences in comparison to the reference cohort. The calculated statistical maps of significantly affected density regions (ADR) started to highlight small local changes of volumetric bone mineral density (vBMD) distribution within the vertebra of L5 (ADR: 7.9%) in the fifties cohort. Regions near the endplates were most affected. The effect dramatically increased in the sixties cohort, where bone loss was most prominent from T12 to L2. In the seventies cohort, around 50% of voxels in T10 to L5 showed significantly decreased vBMD. In conclusion, ADR and local T-score maps of the spine showed age-related local variations in a healthy population, corresponding to known areas of fracture origination and increased fracture incidence. It thus might provide a powerful tool in diagnosis of osteoporosis.

In-home psychosocial skills training for patients with schizophrenia.

OBJECTIVE: The purpose of this study was to test an intervention that adapted the University of California, Los Angeles (UCLA) social and independent living skills program for application in the patient's home and in an outpatient setting in Spain. METHODS: An intervention group of 32 patients with schizophrenia was selected for comparison with a matched control group of patients who were undergoing conventional outpatient treatment for schizophrenia during six-month treatment periods. The Positive and Negative Syndrome Scale (PANSS) scoring system was used to compare the two groups, with a pretest-posttest design. RESULTS: Analysis of variance indicated a significant phase-by-treatment interaction effect of the intervention on PANSS scores. CONCLUSIONS: The results of this study suggest that a combination of outpatient follow-up care and in-home care centered on psychosocial skills training is more effective than conventional treatment in improving general symptoms among individuals with schizophrenia.