Proteogenomic Reprogramming to a Functional Human Totipotent Stem Cell State via a PARP-DUX4 Regulatory Axis.

PARP1 (ARTD1) and Tankyrases (TNKS1/TNKS2; PARP5a/5b) are poly-ADP-ribose polymerases (PARPs) with catalytic and non-catalytic functions that regulate both the genome and proteome during zygotic genome activation (ZGA), totipotent, and pluripotent embryonic stages. Here, we show that primed, conventional human pluripotent stem cells (hPSC) cultured continuously under non-specific TNKS1/TNKS2/PARP1-inhibited chemical naive reversion conditions underwent epigenetic reprogramming to clonal blastomere-like stem cells. TIRN stem cells concurrently expressed hundreds of gene targets of the ZGA-priming pioneer factor DUX4, as well as a panoply of four-cell (4C)-specific (e.g., TPRXL, HOX clusters), eight-cell (8C)-specific (e.g., DUXA, GSC, GATA6), primitive endoderm-specific (e.g., GATA4, SOX17), trophectoderm-specific (e.g., CDX2, TFAP2C), and naive epiblast-specific (e.g., DNMT3L, NANOG, POU5F1(OCT4)) factors; all in a hybrid, combinatorial single-cell manner. Mapping of proteomic and single-cell expressions of TIRN cells against human preimplantation embryo references identified them as relatively homogenous 4C-8C stage populations. Injection of TIRN cells into murine 8C-16C-staged embryos resulted in efficient totipotent-like single cell contributions of human cells to both extra-embryonic (trophectoderm, placenta) and embryonic (neural, fetal liver, hematopoietic) lineages in human-murine blastocyst and fetal chimeras. Pairing of proteome with ubiquitinome analyses of TIRN cells revealed a global shutdown of ADP-ribosylation, and a perturbed TNKS/PARP1 equilibrium which not only impacted the protein levels of hundreds of TNKS/PARP1 substrates via a rewiring of the ubiquitin-proteosome system (UPS), but also de-repressed expression of hundreds of developmental genes associated with PARP1 suppression. ChIP-Seq analysis of core NANOG-SOX2-OCT4 (NSO) pluripotency factors in TIRN cells identified reprogrammed DUX4-accessible distal and cis-regulatory enhancer regions that were co-bound by PARP1 (NSOP). These NSOP enhancer regions possessed co-binding motifs for hundreds of the same ZGA-associated, embryonic, and extraembryonic lineage-specifying pioneer factors (e.g., HOX, FOX, GATA, SOX, TBX, CDX families) that were concurrently co-expressed in TIRN cells; suggesting that PARP1 and DUX4 cooperate with NSO pluripotency core factors to regulate the epigenetic plasticity of a human totipotency program. These findings provide the first demonstration that global, proteome-wide perturbations of post-translational modifications (i.e., ADP-ribosylation, ubiquitination) can regulate epigenetic reprogramming during human embryogenesis. Totipotent TIRN stem cells will provide a valuable cell culture model for studying the proteogenomic regulation of lineage specification from human blastomere stages and may facilitate the efficient generation of human organs in interspecies chimeras.

TCF4 Mutations Disrupt Synaptic Function Through Dysregulation of RIMBP2 in Patient-Derived Cortical Neurons.

BACKGROUND: Genetic variation in the TCF4 (transcription factor 4) gene is associated with risk for a variety of developmental and psychiatric conditions, which includes a syndromic form of autism spectrum disorder called Pitt-Hopkins syndrome (PTHS). TCF4 encodes an activity-dependent transcription factor that is highly expressed during cortical development and in animal models has been shown to regulate various aspects of neuronal development and function. However, our understanding of how disease-causing mutations in TCF4 confer pathophysiology in a human context is lacking. METHODS: To model PTHS, we differentiated human cortical neurons from human induced pluripotent stem cells that were derived from patients with PTHS and neurotypical individuals. To identify pathophysiology and disease mechanisms, we assayed cortical neurons with whole-cell electrophysiology, Ca2+ imaging, multielectrode arrays, immunocytochemistry, and RNA sequencing. RESULTS: Cortical neurons derived from patients with TCF4 mutations showed deficits in spontaneous synaptic transmission, network excitability, and homeostatic plasticity. Transcriptomic analysis indicated that these phenotypes resulted in part from altered expression of genes involved in presynaptic neurotransmission and identified the presynaptic binding protein RIMBP2 as the most differentially expressed gene in PTHS neurons. Remarkably, TCF4-dependent deficits in spontaneous synaptic transmission and network excitability were rescued by increasing RIMBP2 expression in presynaptic neurons. CONCLUSIONS: Taken together, these results identify TCF4 as a critical transcriptional regulator of human synaptic development and plasticity and specifically identifies dysregulation of presynaptic function as an early pathophysiology in PTHS.

TCF4 mutations disrupt synaptic function through dysregulation of RIMBP2 in patient-derived cortical neurons.

Genetic variation in the transcription factor 4 ( TCF4) gene is associated with risk for a variety of developmental and psychiatric conditions, which includes a syndromic form of ASD called Pitt Hopkins Syndrome (PTHS). TCF4 encodes an activity-dependent transcription factor that is highly expressed during cortical development and in animal models is shown to regulate various aspects of neuronal development and function. However, our understanding of how disease-causing mutations in TCF4 confer pathophysiology in a human context is lacking. Here we show that cortical neurons derived from patients with TCF4 mutations have deficits in spontaneous synaptic transmission, network excitability and homeostatic plasticity. Transcriptomic analysis indicates these phenotypes result from altered expression of genes involved in presynaptic neurotransmission and identifies the presynaptic binding protein, RIMBP2 as the most differentially expressed gene in PTHS neurons. Remarkably, TCF4-dependent deficits in spontaneous synaptic transmission and network excitability were rescued by increasing RIMBP2 expression in presynaptic neurons. Together, these results identify TCF4 as a critical transcriptional regulator of human synaptic development and plasticity and specifically identifies dysregulation of presynaptic function as an early pathophysiology in PTHS.

Electrophysiological measures from human iPSC-derived neurons are associated with schizophrenia clinical status and predict individual cognitive performance.

Neurons derived from human induced pluripotent stem cells (hiPSCs) have been used to model basic cellular aspects of neuropsychiatric disorders, but the relationship between the emergent phenotypes and the clinical characteristics of donor individuals has been unclear. We analyzed RNA expression and indices of cellular function in hiPSC-derived neural progenitors and cortical neurons generated from 13 individuals with high polygenic risk scores (PRSs) for schizophrenia (SCZ) and a clinical diagnosis of SCZ, along with 15 neurotypical individuals with low PRS. We identified electrophysiological measures in the patient-derived neurons that implicated altered Na+ channel function, action potential interspike interval, and gamma-aminobutyric acid-ergic neurotransmission. Importantly, electrophysiological measures predicted cardinal clinical and cognitive features found in these SCZ patients. The identification of basic neuronal physiological properties related to core clinical characteristics of illness is a potentially critical step in generating leads for novel therapeutics.

A prospective study of filgrastim pharmacokinetics in morbidly obese patients compared with non-obese controls.

INTRODUCTION: Filgrastim is a human granulocyte colony-stimulating factor (G-CSF). There are limited data on dosing filgrastim in obesity. The objective of this study was to compare filgrastim pharmacokinetic parameters for morbidly obese and non-obese patients after a single subcutaneous dose of filgrastim dosed per actual body weight. METHODS: This prospective, matched-pair study (NCT01719432) included patients ≥18 years of age, receiving filgrastim at 5 µg/kg with a weight >190% of their ideal body weight (IBW) for "morbidly obese" patients or within 80%-124% of IBW for matched-control patients. The control group was prospectively matched for age (within 10 years), degree of neutropenia, and gender. Filgrastim doses were not rounded to vial size, to allow more accurate assessment of exposure. Blood samples were collected at 0 (prior to dose), 2, 4, 6, 8, 12, and 24 h after the first subcutaneous administration of filgrastim. RESULTS: A total of 30 patients were enrolled in this prospective pharmacokinetic study, with 15 patients assigned to each arm. Non-compartmental analysis showed that the systemic clearance (Cl) was 0.111 ± 0.041 ml/min in the morbidly obese group versus 0.124 ± 0.045 ml/min in the non-obese group (p = 0.44). Additionally, the mean area under the curve (AUC0-24h ) was 49.3 ± 13.9 ng/ml × min in the morbidly obese group versus 46.3 ± 16.8 ng/mL x min in the non-obese group (p = 0.6). No differences were seen in maximum concentrations (Cmax ) between the two groups (morbidly obese: 48.1 ± 14.7 ng/ml vs. non-obese: 49.2 ± 20.7 ng/ml (p = 0.87)). The morbidly obese group had a numerically higher, but not statistically significant, increase in time to maximum concentration (Tmax ) compared to the non-obese group (544 ± 145 min vs 436 ± 156 min (p = 0.06), respectively). CONCLUSION: Calculating subcutaneous filgrastim doses using actual body weight appears to produce similar systemic exposure in morbidly obese and non-obese patients with severe neutropenia.

Research: How Medical Device Instructions for Use Engage Users.

Instructions for use (IFUs) often are used as risk control measures for medical devices with the potential to expose users or others to use-related hazards and hazardous situations that are not entirely mitigated by device design. In the authors' extensive experience observing representative users interact with medical devices in simulated-use studies, individuals' engagement with medical device IFUs varies widely. This variance raises questions regarding how various user groups use IFUs and the factors that make an IFU stronger or weaker for its intended users, uses, and use environments. An online survey was conducted to examine (1) first-time use of medical device IFUs, (2) how first-time use strategies vary across typical user groups for medical devices (e.g., patients, lay caregivers, and healthcare professionals), and (3) which design elements promote initial engagement with IFUs. The results showed that IFUs are used in a variety of ways, including as preparation before use, as guides during use, and as troubleshooting resources during use, as well as that IFUs are not used at all. Overall, the user groups tested responded similarly across all of the survey questions. Bullet point organization, figures, and logical flow were reported to be the most engaging design elements. Small font size and poor organization and flow were reported to be the least engaging design elements. IFU designers can use various usability testing methods to assess their assumptions regarding how a product's users will use the IFU and to make the IFU more engaging.

Vascular progenitors generated from tankyrase inhibitor-regulated naïve diabetic human iPSC potentiate efficient revascularization of ischemic retina.

Here, we report that the functionality of vascular progenitors (VP) generated from normal and disease-primed conventional human induced pluripotent stem cells (hiPSC) can be significantly improved by reversion to a tankyrase inhibitor-regulated human naïve epiblast-like pluripotent state. Naïve diabetic vascular progenitors (N-DVP) differentiated from patient-specific naïve diabetic hiPSC (N-DhiPSC) possessed higher vascular functionality, maintained greater genomic stability, harbored decreased lineage-primed gene expression, and were more efficient in migrating to and re-vascularizing the deep neural layers of the ischemic retina than isogenic diabetic vascular progenitors (DVP). These findings suggest that reprogramming to a stable naïve human pluripotent stem cell state may effectively erase dysfunctional epigenetic donor cell memory or disease-associated aberrations in patient-specific hiPSC. More broadly, tankyrase inhibitor-regulated naïve hiPSC (N-hiPSC) represent a class of human stem cells with high epigenetic plasticity, improved multi-lineage functionality, and potentially high impact for regenerative medicine.

Risk assessment for antenatal depression among women who have undergone female genital mutilation or cutting: Are we missing the mark?

BACKGROUND: Although prohibited by specific legislation in Australia, patterns of global migration underscore the importance for local clinicians to recognise and manage potential complications associated with female genital mutilation/cutting (FGM/C). The incidence of antenatal depression in Australia is 10% and may be higher among those with a history of FGM/C (RANZCOG 2 statement: Perinatal Anxiety and Depression, 2012). The phenomenon of cultural embedding could represent a protective factor against an increase in mental health problems among these women. AIM: To determine whether women who have undergone FGM/C are at greater risk of depression in the antenatal period as defined by the Edinburgh Postnatal Depression Scale (EPDS). MATERIALS AND METHODS: A multicentre retrospective case-control study was performed. Participants who had delivered at either of two hospitals, had migrated from FGM/C-prevalent countries and who had undergone FGM/C were assessed and compared with the control group, case-matched by language and religion. RESULTS: Eighty-nine cases were included with an equal number of matched controls. No significant difference in the EPDS score was demonstrated when analysed as a continuous variable (P = 0.41) or as a categorical variable with a cut-off score of 12 (P = 0.12). There was no difference in the number of women who identified as having thoughts of self-harm between the two groups. CONCLUSION: There was no identified increase in the risk of antenatal depression among women who have undergone FGM/C from high-prevalence countries. Consideration must be given to the utility of the EPDS in this population, as well as factors such as cultural embedding.

Chemical Reversion of Conventional Human Pluripotent Stem Cells to a Naïve-like State with Improved Multilineage Differentiation Potency.

Naïve human pluripotent stem cells (N-hPSC) with improved functionality may have a wide impact in regenerative medicine. The goal of this protocol is to efficiently revert lineage-primed, conventional human pluripotent stem cells (hPSC) maintained on either feeder-free or feeder-dependent conditions to a naïve-like pluripotency with improved functionality. This chemical naïve reversion method employs the classical leukemia inhibitory factor (LIF), GSK3ß, and MEK/ERK inhibition cocktail (LIF-2i), supplemented with only a tankyrase inhibitor XAV939 (LIF-3i). LIF-3i reverts conventional hPSC to a stable pluripotent state adopting biochemical, transcriptional, and epigenetic features of the human pre-implantation epiblast. This LIF-3i method requires minimal cell culture manipulation and is highly reproducible in a broad repertoire of human embryonic stem cell (hESC) and transgene-free human induced pluripotent stem cell (hiPSC) lines. The LIF-3i method does not require a re-priming step prior to the differentiation; N-hPSC can be differentiated directly with extremely high efficiencies and maintain karyotypic and epigenomic stabilities (including at imprinted loci). To increase the universality of the method, conventional hPSC are first cultured in the LIF-3i cocktail supplemented with two additional small molecules that potentiate protein kinase A (forskolin) and sonic hedgehog (sHH) (purmorphamine) signaling (LIF-5i). This brief LIF-5i adaptation step significantly enhances the initial clonal expansion of conventional hPSC and permits them to be subsequently naïve-reverted with LIF-3i alone in bulk quantities, thus obviating the need for picking/subcloning rare N-hPSC colonies later. LIF-5i-stabilized hPSCs are subsequently maintained in LIF-3i alone without the need of anti-apoptotic molecules. Most importantly, LIF-3i reversion markedly improves the functional pluripotency of a broad repertoire of conventional hPSC by decreasing their lineage-primed gene expression and erasing the interline variability of directed differentiation commonly observed amongst independent hPSC lines. Representative characterizations of LIF-3i-reverted N-hPSC are provided, and experimental strategies for functional comparisons of isogenic hPSC in lineage-primed vs. naïve-like states are outlined.

Who is and isn't having babies with Down syndrome in western Sydney: a ten year hospital cohort study.

BACKGROUND: Screening for Down syndrome (DS) is a key component of antenatal care, recommended to be universally offered to women irrespective of age or background. Despite this, the diagnosis of DS is often not made until the neonatal period. AIMS: To retrospectively describe and compare the differences in populations with an antenatal diagnosis (AD) and neonatal diagnosis (ND) of DS and to explore why an antenatal diagnosis was not made. MATERIALS AND METHODS: The cohorts were women cared for at Westmead Hospital whose pregnancy received a diagnosis of DS between 2006 and 2015. The demographic variables of the AD and ND cohorts were examined and reasons why an antenatal diagnosis was not made in the ND cohort were analysed. RESULTS: There were 127 diagnoses of DS in the 10-year period, of which 41% were in the ND cohort (n = 52) and 59% in the AD (n = 75). Declaring a religious affiliation rather than Nil Religion was significantly more common in the ND cohort (88.5%) and especially the ND sub-cohort who declined DS screening/testing (95.8%) than the AD cohort (72%, P < 0.05). Women who were not offered screening were significantly younger (P < 0.001) than those who were, with 69% and 20% being ≤30 years, respectively. CONCLUSIONS: The proportion of DS pregnancies diagnosed in the antenatal period in western Sydney could be increased by ensuring younger women are not falsely reassured that DS screening is unnecessary for them. While religious affiliation may be a factor when women decline screening, ensuring appropriate counselling remains important.

The influence of T cell cross-reactivity on HCV-peptide specific human T cell response.

Detection of hepatitis C virus (HCV)-specific T cell response after exposure to hepatitis C in anti-HCV-positive or anti-HCV-negative patients has been associated with an ability to successfully control the infection. However, cross-reactivity between common human pathogens and HCV sequences has been demonstrated. The aim of this study was to investigate the impact of T cell cross-reactivity on HCV-specific T cell responses and their detection in HCV infected and non-infected subjects. The magnitude, function, and cross-reactivity of HCV peptide reactive T cells were studied in non-HCV-infected newborns and adults using a broad array of HCV peptides (601 peptides) spanning the entire HCV sequence. Comparisons were made with responses present in recovered and in chronically HCV-infected patients. HCV peptide reactive T cells are detectable in adults irrespective of previous HCV exposure and cross-reactivity between HCV peptides, and sequences of common pathogens, such as human herpes virus 1, can be demonstrated. Furthermore, the comprehensive magnitude of HCV-peptide reactive T cells present in chronically HCV-infected patients is similar and in some cases even lower than that of HCV-peptide reactive T cell response found in HCV-negative adults. In conclusion, the presence of oligo-specific HCV-peptide reactive T cells in humans does not always reflect a demonstration of previous HCV contact, whereas cross-reactivity with other common pathogens can potentially influence the HCV-specific T cell profile. The conspicuous deficit of HCV-peptide-specific T cells found in chronically HCV-infected patients confirms the profound collapse of virus-specific T cell response caused by HCV persistence.