Bi-allelic NRXN1α deletion in microglia derived from iPSC of an autistic patient increases interleukin-6 production and impairs supporting function on neuronal networking.

Autism spectrum disorder (ASD) is a set of heterogeneous neurodevelopmental conditions, with a highly diverse genetic hereditary component, including altered neuronal circuits, that has an impact on communication skills and behaviours of the affected individuals. Beside the recognised role of neuronal alterations, perturbations of microglia and the associated neuroinflammatory processes have emerged as credible contributors to aetiology and physiopathology of ASD. Mutations in NRXN1, a member of the neurexin family of cell-surface receptors that bind neuroligin, have been associated to ASD. NRXN1 is known to be expressed by neurons where it facilitates synaptic contacts, but it has also been identified in glial cells including microglia. Asserting the impact of ASD-related genes on neuronal versus microglia functions has been challenging. Here, we present an ASD subject-derived induced pluripotent stem cells (iPSC)-based in vitro system to characterise the effects of the ASD-associated NRXN1 gene deletion on neurons and microglia, as well as on the ability of microglia to support neuronal circuit formation and function. Using this approach, we demonstrated that NRXN1 deletion, impacting on the expression of the alpha isoform (NRXN1α), in microglia leads to microglial alterations and release of IL6, a pro-inflammatory interleukin associated with ASD. Moreover, microglia bearing the NRXN1α-deletion, lost the ability to support the formation of functional neuronal networks. The use of recombinant IL6 protein on control microglia-neuron co-cultures or neutralizing antibody to IL6 on their NRXN1α-deficient counterparts, supported a direct contribution of IL6 to the observed neuronal phenotype. Altogether, our data suggest that, in addition to neurons, microglia are also negatively affected by NRXN1α-deletion, and this significantly contributes to the observed neuronal circuit aberrations.

High-throughput neural stem cell-based drug screening identifies S6K1 inhibition as a selective vulnerability in sonic hedgehog-medulloblastoma.

BACKGROUND: Medulloblastoma (MB) is one of the most common malignant brain tumors in children. Current treatments have increased overall survival but can lead to devastating side effects and late complications in survivors, emphasizing the need for new, improved targeted therapies that specifically eliminate tumor cells while sparing the normally developing brain. METHODS: Here, we used a sonic hedgehog (SHH)-MB model based on a patient-derived neuroepithelial stem cell system for an unbiased high-throughput screen with a library of 172 compounds with known targets. Compounds were evaluated in both healthy neural stem cells (NSCs) and tumor cells derived from the same patient. Based on the difference of cell viability and drug sensitivity score between normal cells and tumor cells, hit compounds were selected and further validated in vitro and in vivo. RESULTS: We identified PF4708671 (S6K1 inhibitor) as a potential agent that selectively targets SHH-driven MB tumor cells while sparing NSCs and differentiated neurons. Subsequent validation studies confirmed that PF4708671 inhibited the growth of SHH-MB tumor cells both in vitro and in vivo, and that knockdown of S6K1 resulted in reduced tumor formation. CONCLUSIONS: Overall, our results suggest that inhibition of S6K1 specifically affects tumor growth, whereas it has less effect on non-tumor cells. Our data also show that the NES cell platform can be used to identify potentially effective new therapies and targets for SHH-MB.

Registered nurses' experiences of caring for patients with hypoactive delirium after cardiac surgery - A qualitative study.

OBJECTIVES: Delirium is a common post-cardiac surgery complication that presents as acute changes in mental abilities with confused thinking and a lack of awareness of the surroundings. Delirium symptoms present in hyperactive- and hypoactive forms. Hypoactive delirium is often overlooked. Although nursing interventions are important in preventing and treating hypoactive delirium, studies focusing on nurses' experiences of hypoactive delirium are scarce. This study describes registered nurses' experiences of caring for patients with hypoactive delirium after cardiac surgery. RESEARCH METHODOLOGY/DESIGN: This was a qualitative descriptive study with an inductive approach. Data was collected through focus group interviews with 12 registered nurses with experience in caring for cardiac surgery patients with hypoactive delirium. The study complied with the Consolidated Criteria for Reporting Qualitative Research. SETTING: A cardiac surgery department at a Swedish University Hospital. FINDINGS: The analysis resulted in one main category; "Navigating the complexities of care when caring for patients with hypoactive delirium" and three sub-categories: "Challenges, "Nursing interventions" and "Promoting a team approach". CONCLUSION: Delirium assessment and nursing interventions are perceived as essential yet demanding. when caring for patients with hypoactive delirium. Nursing interventions like maintaining the circadian rhythm and offering emotional support need to be prioritised by the nurses, in line with the autonomy of the registered nurse's profession. Moreover, the team around the patient is crucial for detecting and treating hypoactive delirium, and it is important to involve other professionals as well as the patient's relatives. Future research is needed to develop assessment instruments that more accurately capture hypoactive delirium in the postoperative setting. IMPLICATIONS FOR CLINICAL PRACTICE: Despite the use of screening tools, nurses still experience challenges in detecting the symptoms of hypoactive delirium, indicating a need for more clinically effective screening tools for hypoactive delirium. Nursing interventions are emphasised in the care of patients with hypoactive delirium.

Pre-clinical evaluation of clinically relevant iPS cell derived neuroepithelial stem cells as an off-the-shelf cell therapy for spinal cord injury.

Preclinical transplantations using human neuroepithelial stem (NES) cells in spinal cord injury models have exhibited promising results and demonstrated cell integration and functional improvement in transplanted animals. Previous studies have relied on the generation of research grade cell lines in continuous culture. Using fresh cells presents logistic hurdles for clinical transition regarding time and resources for maintaining high quality standards. In this study, we generated a good manufacturing practice (GMP) compliant human iPS cell line in GMP clean rooms alongside a research grade iPS cell line which was produced using standardized protocols with GMP compliant chemicals. These two iPS cell lines were differentiated into human NES cells, from which six batches of cell therapy doses were produced. The doses were cryopreserved, thawed on demand and grafted in a rat spinal cord injury model. Our findings demonstrate that NES cells can be directly grafted post-thaw with high cell viability, maintaining their cell identity and differentiation capacity. This opens the possibility of manufacturing off-the-shelf cell therapy products. Moreover, our manufacturing process yields stable cell doses with minimal batch-to-batch variability, characterized by consistent expression of identity markers as well as similar viability of cells across the two iPS cell lines. These cryopreserved cell doses exhibit sustained viability, functionality, and quality for at least 2 years. Our results provide proof of concept that cryopreserved NES cells present a viable alternative to transplanting freshly cultured cells in future cell therapies and exemplify a platform from which cell formulation can be optimized and facilitate the transition to clinical trials.

On-Chip Neural Induction Boosts Neural Stem Cell Commitment: Toward a Pipeline for iPSC-Based Therapies.

The clinical translation of induced pluripotent stem cells (iPSCs) holds great potential for personalized therapeutics. However, one of the main obstacles is that the current workflow to generate iPSCs is expensive, time-consuming, and requires standardization. A simplified and cost-effective microfluidic approach is presented for reprogramming fibroblasts into iPSCs and their subsequent differentiation into neural stem cells (NSCs). This method exploits microphysiological technology, providing a 100-fold reduction in reagents for reprogramming and a ninefold reduction in number of input cells. The iPSCs generated from microfluidic reprogramming of fibroblasts show upregulation of pluripotency markers and downregulation of fibroblast markers, on par with those reprogrammed in standard well-conditions. The NSCs differentiated in microfluidic chips show upregulation of neuroectodermal markers (ZIC1, PAX6, SOX1), highlighting their propensity for nervous system development. Cells obtained on conventional well plates and microfluidic chips are compared for reprogramming and neural induction by bulk RNA sequencing. Pathway enrichment analysis of NSCs from chip showed neural stem cell development enrichment and boosted commitment to neural stem cell lineage in initial phases of neural induction, attributed to a confined environment in a microfluidic chip. This method provides a cost-effective pipeline to reprogram and differentiate iPSCs for therapeutics compliant with current good manufacturing practices.

Self-reported preoperative depressive symptoms and survival after cardiac surgery.

OBJECTIVES: Depression has been associated with increased cardiovascular morbidity and mortality. This study aimed to determine whether self-reported preoperative depressive symptoms were associated with worse long-term survival in patients undergoing cardiac surgery. METHODS: This population-based, observational cohort study included patients who had undergone cardiac surgery at Karolinska University Hospital between 2013 and 2016. Self-reported data about depressive symptoms were collected using the Patient Health Questionnaire (PHQ-9) and other patient data were collected from the institutional surgical database and medical charts. Depression was defined as a PHQ-9 score ≥10. Weighted flexible parametric survival models were used to estimate the association between self-reported preoperative depressive symptoms and all-cause mortality and to quantify absolute survival differences. RESULTS: Of the 1120 study patients, 162 (14.5%) had depressive symptoms before cardiac surgery. During a mean follow-up of 7.2 years (maximum, 9.2 years), there were 36 deaths in 1129 person-years (PYs) in the depressed group, compared to 160 deaths in 6889 PYs in the non-depressed group. In the adjusted analysis, self-reported depressive symptoms were associated with worse long-term survival (hazard ratio 1.66; 95% confidence interval 1.09-2.54) compared with no reported depressive symptoms. The absolute survival differences (% and 95% confidence interval) between the non-depressed and the depressed patients were -1.9 (-3.9 to 0.19), -5.7 (-11 to -0.01) and -9.7 (-19 to -0.4) after 1, 5 and 8 years, respectively. CONCLUSIONS: Self-reported preoperative depressive symptoms were associated with worse long-term survival following cardiac surgery and should be regarded as important as other classical risk factors.

Unraveling the brain's response to COVID-19: How SARS-CoV-2 afflicts dopaminergic neurons.

COVID-19 patients often display dysfunctions of the nervous system, indicating an effect of SARS-CoV-2 on neural cells. Yang et al. now show that human stem-cell-derived dopaminergic neurons are susceptible to SARS-CoV-2, triggering inflammation and senescence. The study further identifies three FDA-approved drugs capable of reversing these cellular phenotypes.

Deficiency of the Heterogeneous Nuclear Ribonucleoprotein U locus leads to delayed hindbrain neurogenesis.

Genetic variants affecting Heterogeneous Nuclear Ribonucleoprotein U (HNRNPU) have been identified in several neurodevelopmental disorders (NDDs). HNRNPU is widely expressed in the human brain and shows the highest postnatal expression in the cerebellum. Recent studies have investigated the role of HNRNPU in cerebral cortical development, but the effects of HNRNPU deficiency on cerebellar development remain unknown. Here, we describe the molecular and cellular outcomes of HNRNPU locus deficiency during in vitro neural differentiation of patient-derived and isogenic neuroepithelial stem cells with a hindbrain profile. We demonstrate that HNRNPU deficiency leads to chromatin remodeling of A/B compartments, and transcriptional rewiring, partly by impacting exon inclusion during mRNA processing. Genomic regions affected by the chromatin restructuring and host genes of exon usage differences show a strong enrichment for genes implicated in epilepsies, intellectual disability, and autism. Lastly, we show that at the cellular level HNRNPU downregulation leads to an increased fraction of neural progenitors in the maturing neuronal population. We conclude that the HNRNPU locus is involved in delayed commitment of neural progenitors to differentiate in cell types with hindbrain profile.

Suffering in silence - Cardiac surgery patients recalling hypoactive delirium a qualitative descriptive study.

OBJECTIVES: Postoperative delirium affects up to 50% of patients undergoing cardiac surgery. Delirium phenotypes are commonly divided into hyperactive and hypoactive, with hypoactive symptoms (reduced motor activity and withdrawal) often being overlooked due to their discreet character. Although the consequences of hypoactive delirium are severe, studies focusing on patients' experiences of hypoactive delirium are scarce. The aim of the study was to describe cardiac surgery patients' experiences of hypoactive delirium. RESEARCH METHODOLOGY/DESIGN: We used qualitative descriptive semi-structured interviews with an inductive, latent approach. Twelve patients with hypoactive symptoms of delirium after cardiac surgery were purposefully selected. Interview data were analysed by qualitative content analysis. FINDINGS: Two themes based on eight sub-themes emerged. "Dream or reality in parallel worlds" included disturbing experiences of existing in parallel realities with cognitive effects, residual nightmares, and illusions that occasionally persisted after hospital discharge. "Managing the state of hypoactive delirium" included experiences of intellectually dealing with hypoactive delirium with assumptions of causes and cures, and through interactions like communicating with others. CONCLUSION: Participants experienced hypoactive delirium as extensive and long-lasting with perceptions of existing in parallel realities. The findings emphasize the need for healthcare professionals to have expertise in hypoactive delirium and its fluctuating course, as the delirium of many patients may be undetected and undiagnosed. Improving the use of screening tools for clinical practice is essential for the detection of hypoactive delirium, and a person-centred approach is needed to properly care for this group of patients. IMPLICATIONS FOR CLINICAL PRACTICE: The challenges in the recognition of hypoactive delirium need to be emphasized because the syndrome is still overlooked. The use of screening tools in clinical practice is essential. A person-centred approach supports relationships between delirious patients and healthcare professionals.

Screening autism-associated environmental factors in differentiating human neural progenitors with fractional factorial design-based transcriptomics.

Research continues to identify genetic variation, environmental exposures, and their mixtures underlying different diseases and conditions. There is a need for screening methods to understand the molecular outcomes of such factors. Here, we investigate a highly efficient and multiplexable, fractional factorial experimental design (FFED) to study six environmental factors (lead, valproic acid, bisphenol A, ethanol, fluoxetine hydrochloride and zinc deficiency) and four human induced pluripotent stem cell line derived differentiating human neural progenitors. We showcase the FFED coupled with RNA-sequencing to identify the effects of low-grade exposures to these environmental factors and analyse the results in the context of autism spectrum disorder (ASD). We performed this after 5-day exposures on differentiating human neural progenitors accompanied by a layered analytical approach and detected several convergent and divergent, gene and pathway level responses. We revealed significant upregulation of pathways related to synaptic function and lipid metabolism following lead and fluoxetine exposure, respectively. Moreover, fluoxetine exposure elevated several fatty acids when validated using mass spectrometry-based metabolomics. Our study demonstrates that the FFED can be used for multiplexed transcriptomic analyses to detect relevant pathway-level changes in human neural development caused by low-grade environmental risk factors. Future studies will require multiple cell lines with different genetic backgrounds for characterising the effects of environmental exposures in ASD.

Age-related pathological impairments in directly reprogrammed dopaminergic neurons derived from patients with idiopathic Parkinson's disease.

We have developed an efficient approach to generate functional induced dopaminergic (DA) neurons from adult human dermal fibroblasts. When performing DA neuronal conversion of patient fibroblasts with idiopathic Parkinson's disease (PD), we could specifically detect disease-relevant pathology in these cells. We show that the patient-derived neurons maintain age-related properties of the donor and exhibit lower basal chaperone-mediated autophagy compared with healthy donors. Furthermore, stress-induced autophagy resulted in an age-dependent accumulation of macroautophagic structures. Finally, we show that these impairments in patient-derived DA neurons leads to an accumulation of phosphorylated alpha-synuclein, the classical hallmark of PD pathology. This pathological phenotype is absent in neurons generated from induced pluripotent stem cells from the same patients. Taken together, our results show that direct neural reprogramming can be used for obtaining patient-derived DA neurons, which uniquely function as a cellular model to study age-related pathology relevant to idiopathic PD.

Multi-Omic Investigations of a 17-19 Translocation Links MINK1 Disruption to Autism, Epilepsy and Osteoporosis.

Balanced structural variants, such as reciprocal translocations, are sometimes hard to detect with sequencing, especially when the breakpoints are located in repetitive or insufficiently mapped regions of the genome. In such cases, long-range information is required to resolve the rearrangement, identify disrupted genes and, in symptomatic carriers, pinpoint the disease-causing mechanisms. Here, we report an individual with autism, epilepsy and osteoporosis and a de novo balanced reciprocal translocation: t(17;19) (p13;p11). The genomic DNA was analyzed by short-, linked- and long-read genome sequencing, as well as optical mapping. Transcriptional consequences were assessed by transcriptome sequencing of patient-specific neuroepithelial stem cells derived from induced pluripotent stem cells (iPSC). The translocation breakpoints were only detected by long-read sequencing, the first on 17p13, located between exon 1 and exon 2 of MINK1 (Misshapen-like kinase 1), and the second in the chromosome 19 centromere. Functional validation in induced neural cells showed that MINK1 expression was reduced by >50% in the patient's cells compared to healthy control cells. Furthermore, pathway analysis revealed an enrichment of changed neural pathways in the patient's cells. Altogether, our multi-omics experiments highlight MINK1 as a candidate monogenic disease gene and show the advantages of long-read genome sequencing in capturing centromeric translocations.

Multi-omics analysis reveals multiple mechanisms causing Prader-Willi like syndrome in a family with a X;15 translocation.

Prader-Willi syndrome (PWS; MIM# 176270) is a neurodevelopmental disorder caused by the loss of expression of paternally imprinted genes within the PWS region located on 15q11.2. It is usually caused by either maternal uniparental disomy of chromosome 15 (UPD15) or 15q11.2 recurrent deletion(s). Here, we report a healthy carrier of a balanced X;15 translocation and her two daughters, both with the karyotype 45,X,der(X)t(X;15)(p22;q11.2),-15. Both daughters display symptoms consistent with haploinsufficiency of the SHOX gene and PWS. We explored the architecture of the derivative chromosomes and investigated effects on gene expression in patient-derived neural cells. First, a multiplex ligation-dependent probe amplification methylation assay was used to determine the methylation status of the PWS-region revealing maternal UPD15 in daughter 2, explaining her clinical symptoms. Next, short read whole genome sequencing and 10X genomics linked read sequencing was used to pinpoint the exact breakpoints of the translocation. Finally, we performed transcriptome sequencing on neuroepithelial stem cells from the mother and from daughter 1 and observed biallelic expression of genes in the PWS region (including SNRPN) in daughter 1. In summary, our multi-omics analysis highlights two different PWS mechanisms in one family and provide an example of how structural variation can affect imprinting through long-range interactions.

Depression is associated with delirium after cardiac surgery-a population-based cohort study.

OBJECTIVES: Depression is common in patients with cardiac disease, and preoperative depression is associated with worse outcomes after cardiac surgery. Depression is also correlated with postoperative delirium (POD) after major surgery. However, the association between preoperative depression and POD after cardiac surgery is sparsely studied. The aim of this study was to investigate depression as a predictor for POD in cardiac surgery patients. METHODS: This population-based cohort study included 1133 cardiac surgery patients in Stockholm 2013-2016. Depression was defined by the Patient Health Questionnaire-9, and POD was evaluated by assessing medical records for symptoms of POD according to Diagnostic and Statistical Manual of Mental Disorders criteria. The association between depression and POD was determined through multivariable logistic regression analysis. RESULTS: A total of 162 (14%) individuals reported depressive symptoms preoperatively. The incidence of POD was 26% and highest among elderly patients. Among patients with depression, 34% developed POD. In the group of non-depressed patients, 24% developed POD. The overall adjusted odds of delirium were 2.19 times higher in individuals with depressive symptoms compared to controls (95% confidence interval 1.43-3.34). The onset of delirium was most common on Days 0-2 after surgery. CONCLUSIONS: This unique population-based study in patients undergoing cardiac surgery shows that preoperative depression is associated with POD in a large proportion of treated patients. The findings support the need for improved preoperative screening for depression, especially in younger patients, and enhanced clinical surveillance in the early postoperative period for all patients.

Glyphosate-based herbicide induces long-lasting impairment in neuronal and glial differentiation.

Glyphosate-based herbicides (GBH) are among the most sold pesticides in the world. There are several formulations based on the active ingredient glyphosate (GLY) used along with other chemicals to improve the absorption and penetration in plants. The final composition of commercial GBH may modify GLY toxicological profile, potentially enhancing its neurotoxic properties. The developing nervous system is particularly susceptible to insults occurring during the early phases of development, and exposure to chemicals in this period may lead to persistent impairments on neurogenesis and differentiation. The aim of this study was to evaluate the long-lasting effects of a sub-cytotoxic concentration, 2.5 parts per million of GBH and GLY, on the differentiation of human neuroepithelial stem cells (NES) derived from induced pluripotent stem cells (iPSC). We treated NES cells with each compound and evaluated the effects on key cellular processes, such as proliferation and differentiation in daughter cells never directly exposed to the toxicants. We found that GBH induced a more immature neuronal profile associated to increased PAX6, NESTIN and DCX expression, and a shift in the differentiation process toward glial cell fate at the expense of mature neurons, as shown by an increase in the glial markers GFAP, GLT1, GLAST and a decrease in MAP2. Such alterations were associated to dysregulation of key genes critically involved in neurogenesis, including PAX6, HES1, HES5, and DDK1. Altogether, the data indicate that subtoxic concentrations of GBH, but not of GLY, induce long-lasting impairments on the differentiation potential of NES cells.

Multiple therapeutic effects of human neural stem cells derived from induced pluripotent stem cells in a rat model of post-traumatic syringomyelia.

BACKGROUND: Post-traumatic syringomyelia (PTS) affects patients with chronic spinal cord injury (SCI) and is characterized by progressive deterioration of neurological symptoms. To improve surgical treatment, we studied the therapeutic effects of neuroepithelial-like stem cells (NESCs) derived from induced pluripotent stem cells (iPSCs) in a rat model of PTS. To facilitate clinical translation, we studied NESCs derived from Good Manufacturing Practice (GMP)-compliant iPSCs. METHODS: Human GMP-compliant iPSCs were used to derive NESCs. Cryo-preserved NESCs were used off-the-shelf for intraspinal implantation to PTS rats 1 or 10 weeks post-injury, and rats were sacrificed 10 weeks later. In vivo cyst volumes were measured with micro-MRI. Phenotypes of differentiated NESCs and host responses were analyzed by immunohistochemistry. FINDINGS: Off-the-shelf NESCs transplanted to PTS rats 10 weeks post-injury reduced cyst volume. The grafted NESCs differentiated mainly into glial cells. Importantly, NESCs also stimulated tissue repair. They reduced the density of glial scars and neurite-inhibiting chondroitin sulfate proteoglycan 4 (CSPG4), stimulated host oligodendrocyte precursor cells to migrate and proliferate, reduced active microglia/macrophages, and promoted axonal regrowth after subacute as well as chronic transplantation. INTERPRETATION: Significant neural repair promoted by NESCs demonstrated that human NESCs could be used as a complement to standard surgery in PTS. We envisage that future PTS patients transplanted with NESCs will benefit both from eliminating the symptoms of PTS, as well as a long-term improvement of the neurological symptoms of SCI. FUNDING: This work was supported by Vinnova (2016-04134), Karolinska Institutet StratRegen, and the Chinese Scholarship Council.

Crosstalk between astrocytes and microglia results in increased degradation of α-synuclein and amyloid-ß aggregates.

BACKGROUND: Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by brain accumulation of aggregated amyloid-beta (Aß) and alpha-synuclein (αSYN), respectively. In order to develop effective therapies, it is crucial to understand how the Aß/αSYN aggregates can be cleared. Compelling data indicate that neuroinflammatory cells, including astrocytes and microglia, play a central role in the pathogenesis of AD and PD. However, how the interplay between the two cell types affects their clearing capacity and consequently the disease progression remains unclear. METHODS: The aim of the present study was to investigate in which way glial crosstalk influences αSYN and Aß pathology, focusing on accumulation and degradation. For this purpose, human-induced pluripotent cell (hiPSC)-derived astrocytes and microglia were exposed to sonicated fibrils of αSYN or Aß and analyzed over time. The capacity of the two cell types to clear extracellular and intracellular protein aggregates when either cultured separately or in co-culture was studied using immunocytochemistry and ELISA. Moreover, the capacity of cells to interact with and process protein aggregates was tracked using time-lapse microscopy and a customized "close-culture" chamber, in which the apical surfaces of astrocyte and microglia monocultures were separated by a <1 mm space. RESULTS: Our data show that intracellular deposits of αSYN and Aß are significantly reduced in co-cultures of astrocytes and microglia, compared to monocultures of either cell type. Analysis of conditioned medium and imaging data from the "close-culture" chamber experiments indicate that astrocytes secrete a high proportion of their internalized protein aggregates, while microglia do not. Moreover, co-cultured astrocytes and microglia are in constant contact with each other via tunneling nanotubes and other membrane structures. Notably, our live cell imaging data demonstrate that microglia, when attached to the cell membrane of an astrocyte, can attract and clear intracellular protein deposits from the astrocyte. CONCLUSIONS: Taken together, our data demonstrate the importance of astrocyte and microglia interactions in Aß/αSYN clearance, highlighting the relevance of glial cellular crosstalk in the progression of AD- and PD-related brain pathology.

Protocol for the derivation, culturing, and differentiation of human iPS-cell-derived neuroepithelial stem cells to study neural differentiation in vitro.

Here, we present a revised protocol to derive neuroepithelial stem (NES) cells from human induced pluripotent stem cells. NES cells can be further differentiated into a culture of neurons (90%) and glia (10%). We describe how to derive and maintain NES cells in culture and how to differentiate them. In addition, we show the potential use of NES cells to study the role of reactive oxygen species in neuronal differentiation and a guideline for NES cell transfection. For complete details on the use and execution of this protocol, please refer to Calvo-Garrido et al. (2019); Falk et al. (2012).

Depression as a predictor of postoperative delirium after cardiac surgery: a systematic review and meta-analysis.

OBJECTIVES: Depression is common in patients with cardiac disease. The importance of preoperative depression for development of postoperative delirium (POD) following cardiac surgery is not well known. The aim is to provide a summary estimate of depression as a predictor of POD following cardiac surgery. METHODS: Systematic search of MEDLINE, EMBASE, Cochrane Library, Web of Science Core Collection and Psycinfo (Ovid) was performed from inception to October 2019, including cohort studies reporting odds ratios (ORs) and 95% confidence intervals (CIs) for POD following cardiac surgery in patients with preoperative depression compared to patients without depression. ORs and 95% CIs for POD were calculated using random-effects meta-analyses. Subgroup and sensitivity analyses were performed. RESULTS: Seven studies were included with a combined study population of 2066 patients. The pooled prevalence of POD in the combined study population was 26% and preoperative depression was present in ∼9% of the total study population. All studies showed a positive association between preoperative depression and POD; and in 5 studies, the association was statistically significant. Patients with depression had a pooled OR of 2.31 (95% CI 1.37-3.90) for POD. CONCLUSIONS: This systematic review and meta-analysis confirm the findings that the previous association between preoperative depression and increased risk for developing POD reported for other patient groups is found also in cardiac surgery. Depression screening prior to cardiac surgery may be effective in identifying patients at higher risk for POD.

Transplantation of Human Neural Precursor Cells Reverses Syrinx Growth in a Rat Model of Post-Traumatic Syringomyelia.

Posttraumatic syringomyelia (PTS) is a serious condition of progressive expansion of spinal cord cysts, affecting patients with spinal cord injury years after injury. To evaluate neural cell therapy to prevent cyst expansion and potentially replace lost neurons, we developed a rat model of PTS. We combined contusive trauma with subarachnoid injections of blood, causing tethering of the spinal cord to the surrounding vertebrae, resulting in chronically expanding cysts. The cysts were usually located rostral to the injury, extracanalicular, lined by astrocytes. T2*-weighted magnetic resonance imaging (MRI) showed hyperintense fluid-filled cysts but also hypointense signals from debris and iron-laden macrophages/microglia. Two types of human neural stem/progenitor cells-fetal neural precursor cells (hNPCs) and neuroepithelial-like stem cells (hNESCs) derived from induced pluripotent stem cells-were transplanted to PTS cysts. Cells transplanted into cysts 10 weeks after injury survived at least 10 weeks, migrated into the surrounding parenchyma, but did not differentiate during this period. The cysts were partially obliterated by the cells, and cyst walls often merged with thin layers of cells in between. Cyst volume measurements with MRI showed that the volumes continued to expand in sham-transplanted rats by 102%, while the cyst expansion was effectively prevented by hNPCs and hNESCs transplantation, reducing the cyst volumes by 18.8% and 46.8%, respectively. The volume reductions far exceeded the volume of the added human cells. Thus, in an animal model closely mimicking the clinical situation, we provide proof-of-principle that transplantation of human neural stem/progenitor cells can be used as treatment for PTS.