An Optimized Method to Produce Human-Induced Pluripotent Stem Cell-Derived Limbal Stem Cells Easily Adaptable for Clinical Use.

In adults, the limbal stem cells (LSC) reside in the limbal region of the eye, at the junction of the cornea and the sclera where they renew the outer epithelial layer of the cornea assuring transparency. LSC deficiencies (LSCD) due to disease or injury account for one of the major causes of blindness. Among current treatments for LSCD, cornea transparency can be restored by providing new LSC to the damaged eye and induced pluripotent stem cells (iPSC) holds great promise as a new advanced cell source.

NLRP3 inflammasome mediates astroglial dysregulation of innate and adaptive immune responses in schizophrenia.

Mounting evidence indicates the involvement of neuroinflammation in the development of schizophrenia (SCZ), but the potential role of astroglia in this phenomenon remains poorly understood. We assessed the molecular and functional consequences of inflammasome activation using induced pluripotent stem cell (iPSC)-derived astrocytes generated from SCZ patients and healthy controls (CTRL). Screening protein levels in astrocytes at baseline identified lower expression of the NLRP3-ASC complex in SCZ, but increased Caspase-1 activity upon specific NLRP3 stimulation compared to CTRL.

Elevated levels of peripheral and central nervous system immune markers reflect innate immune dysregulation in autism spectrum disorder.

Background: Evidence suggests dysregulated immune functions in the pathophysiology of Autism spectrum disorder (ASD), although specific immune mechanisms are yet to be identified.

Methods: We assessed circulating levels of 25 immune/neuroinflammatory markers in a large ASD sample (n = 151) and matched controls (n = 72) using linear models. In addition, we performed global brain transcriptomics analyses of relevant immune-related genes.

Bipolar patients display stoichiometric imbalance of gene expression in post-mortem brain samples.

Bipolar disorder is a severe neuro-psychiatric condition where genome-wide association and sequencing studies have pointed to dysregulated gene expression as likely to be causal. We observed strong correlation in expression between GWAS-associated genes and hypothesised that healthy function depends on balance in the relative expression levels of the associated genes and that patients display stoichiometric imbalance. We developed a method for quantifying stoichiometric imbalance and used this to predict each sample's diagnosis probability in four cortical brain RNAseq datasets.

Proteomic Analysis of Human iPSC-Derived Neural Stem Cells and Motor Neurons Identifies Proteasome Structural Alterations.

Background: Proteins targeted by the ubiquitin proteasome system (UPS) are identified for degradation by the proteasome, which has been implicated in the development of neurodegenerative diseases. Major histocompatibility complex (MHC) molecules present peptides broken down by the proteasome and are involved in neuronal plasticity, regulating the synapse number and axon regeneration in the central or peripheral nervous system during development and in brain diseases. The mechanisms governing these effects are mostly unknown, but evidence from different compartments of the cerebral cortex indicates the presence of immune-like MHC receptors in the central nervous system.

Longitudinal Transcriptomic Analysis of Human Cortical Spheroids Identifies Axonal Dysregulation in the Prenatal Brain as a Mediator of Genetic Risk for Schizophrenia.

Background: Schizophrenia (SCZ) has a known neurodevelopmental etiology, but limited access to human prenatal brain tissue hampers the investigation of basic disease mechanisms in early brain development. Here, we elucidate the molecular mechanisms contributing to SCZ risk in a disease-relevant model of the prenatal human brain.

Methods: We generated induced pluripotent stem cell-derived organoids, termed human cortical spheroids (hCSs), from a large, genetically stratified sample of 14 SCZ cases and 14 age- and sex-matched controls.

Transcriptional and functional effects of lithium in bipolar disorder iPSC-derived cortical spheroids.

Lithium (Li) is recommended for long-term treatment of bipolar disorder (BD). However, its mechanism of action is still poorly understood. Induced pluripotent stem cell (iPSC)-derived brain organoids have emerged as a powerful tool for modeling BD-related disease mechanisms.

Systemic Cell Adhesion Molecules in Severe Mental Illness: Potential Role of Intercellular CAM-1 in Linking Peripheral and Neuroinflammation.

Background: Cell adhesion molecules (CAMs) orchestrate leukocyte trafficking and could link peripheral and neuroinflammation in patients with severe mental illness (SMI), by promoting inflammatory and immune-mediated responses and mediating signals across blood-brain barrier. We hypothesized that CAMs would be dysregulated in SMI and evaluated plasma levels of different vascular and neural CAMs. Dysregulated CAMs in plasma were further evaluated in vivo in leukocytes and brain tissue and in vitro in induced pluripotent stem cells.

A human iPSC-astroglia neurodevelopmental model reveals divergent transcriptomic patterns in schizophrenia.

While neurodevelopmental abnormalities have been associated with schizophrenia (SCZ), the role of astroglia in disease pathophysiology remains poorly understood. In the present study, we used a human induced pluripotent stem cell (iPSC)-derived astrocyte model to investigate the temporal patterns of astroglia differentiation during developmental stages critical for SCZ using RNA sequencing. The model generated astrocyte-specific gene expression patterns during differentiation that corresponded well to astroglia-specific expression signatures of in vivo cortical fetal development.

Lithium increases mitochondrial respiration in iPSC-derived neural precursor cells from lithium responders.

Lithium (Li), valproate (VPA) and lamotrigine (LTG) are commonly used to treat bipolar disorder (BD). While their clinical efficacy is well established, the mechanisms of action at the molecular level are still incompletely understood. Here we investigated the molecular effects of Li, LTG and VPA treatment in induced pluripotent stem cell (iPSC)-derived neural precursor cells (NPCs) generated from 3 healthy controls (CTRL), 3 affective disorder Li responsive patients (Li-R) and 3 Li non-treated patients (Li-N) after 6 h and 1 week of exposure.

A synthetic mRNA cell reprogramming method using CYCLIN D1 promotes DNA repair, generating improved genetically stable human induced pluripotent stem cells.

A key challenge for clinical application of induced pluripotent stem cells (iPSC) to accurately model and treat human pathologies depends on developing a method to generate genetically stable cells to reduce long-term risks of cell transplant therapy. Here, we hypothesized that CYCLIN D1 repairs DNA by highly efficient homologous recombination (HR) during reprogramming to iPSC that reduces genetic instability and threat of neoplastic growth. We adopted a synthetic mRNA transfection method using clinically compatible conditions with CYCLIN D1 plus base factors (OCT3/4, SOX2, KLF4, LIN28) and compared with methods that use C-MYC.

Using iPSC Models to Understand the Role of Estrogen in Neuron-Glia Interactions in Schizophrenia and Bipolar Disorder.

Schizophrenia (SCZ) and bipolar disorder (BIP) are severe mental disorders with a considerable disease burden worldwide due to early age of onset, chronicity, and lack of efficient treatments or prevention strategies. Whilst our current knowledge is that SCZ and BIP are highly heritable and share common pathophysiological mechanisms associated with cellular signaling, neurotransmission, energy metabolism, and neuroinflammation, the development of novel therapies has been hampered by the unavailability of appropriate models to identify novel targetable pathomechanisms. Recent data suggest that neuron-glia interactions are disturbed in SCZ and BIP, and are modulated by estrogen (E2).

Plant hormones increase efficiency of reprogramming mouse somatic cells to induced pluripotent stem cells and reduce tumorigenicity.

Reprogramming of somatic cells into induced pluripotent stem (iPS) cells by defined pluripotency and self-renewal factors has taken stem cell technology to the forefront of regenerative medicine. However, a number of challenges remain in the field including efficient protocols and the threat of cancer. Reprogramming of plant somatic cells to plant embryonic stem cells using a combination of two plant hormones was discovered in 1957 and has been a routine university laboratory practical for over 30 years.