SARS-CoV-2 infection causes dopaminergic neuron senescence

COVID-19 patients commonly present with signs of central nervous system and/or peripheral nervous system dysfunction. Here, we show that midbrain dopamine (DA) neurons derived from human pluripotent stem cells (hPSCs) are selectively susceptible and permissive to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. SARS-CoV-2 infection of DA neurons triggers an inflammatory and cellular senescence response. High-throughput screening in hPSC-derived DA neurons identified several FDA-approved drugs that can rescue the cellular senescence phenotype by preventing SARS-CoV-2 infection. We also identified the inflammatory and cellular senescence signature and low levels of SARS-CoV-2 transcripts in human substantia nigra tissue of COVID-19 patients. Furthermore, we observed reduced numbers of neuromelanin+ and tyrosine-hydroxylase (TH)+ DA neurons and fibers in a cohort of severe COVID-19 patients. Our findings demonstrate that hPSC-derived DA neurons are susceptible to SARS-CoV-2, identify candidate neuroprotective drugs for COVID-19 patients, and suggest the need for careful, long-term monitoring of neurological problems in COVID-19 patients.</p

SARS-CoV-2 infection causes dopaminergic neuron senescence

COVID-19 patients commonly present with signs of central nervous system and/or peripheral nervous system dysfunction. Here, we show that midbrain dopamine (DA) neurons derived from human pluripotent stem cells (hPSCs) are selectively susceptible and permissive to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. SARS-CoV-2 infection of DA neurons triggers an inflammatory and cellular senescence response. High-throughput screening in hPSC-derived DA neurons identified several FDA-approved drugs that can rescue the cellular senescence phenotype by preventing SARS-CoV-2 infection. We also identified the inflammatory and cellular senescence signature and low levels of SARS-CoV-2 transcripts in human substantia nigra tissue of COVID-19 patients. Furthermore, we observed reduced numbers of neuromelanin+ and tyrosine-hydroxylase (TH)+ DA neurons and fibers in a cohort of severe COVID-19 patients. Our findings demonstrate that hPSC-derived DA neurons are susceptible to SARS-CoV-2, identify candidate neuroprotective drugs for COVID-19 patients, and suggest the need for careful, long-term monitoring of neurological problems in COVID-19 patients.</p

Derivation and characterization of a UCP1 reporter human ES cell line

Interest in human brown fat as a novel therapeutic target to tackle the growing obesity and diabetes epidemic has increased dramatically in recent years. While much insight into brown fat biology has been gained from murine cell lines and models, few resources are available to study human brown fat in vitro, which makes the need for new ways to derive and study human brown adipocytes imperative. Human ES cell based reporter systems present an excellent tool to identify, mark, and purify cell populations of choice. In this study, we detail the derivation and characterization of a novel human ES UCP1 reporter cell line that marks UCP1 positive adipocytes in vitro. We targeted a mCherry reporter to the UCP1 stop codon via CRISPR-Cas9 based gene targeting. The brown adipocytes derived from reporter cells express UCP1, display high mitochondrial content, multi-locular lipid morphology, and exhibit functional properties such as lipolysis. The mCherry positive cells purified after cell sorting show elevated expression of brown fat marker genes and a high similarity to isolated human brown fat via RNA-seq analysis. Finally, we demonstrate the utility of this reporter to real time monitor UCP1 expression upon stimulation. This reporter cell line thus presents new opportunities to study human brown fat biology by enabling future work to understand early human brown fat development, perform disease modeling, and facilitate drug screening

Pre- and peri-implantation Zika virus infection impairs fetal development by targeting trophectoderm cells

Zika virus (ZIKV) infection results in an increased risk of spontaneous abortion and poor intrauterine growth although the underlying mechanisms remain undetermined. Little is known about the impact of ZIKV infection during the earliest stages of pregnancy, at pre- and peri-implantation, because most current ZIKV pregnancy studies have focused on post-implantation stages. Here, we demonstrate that trophectoderm cells of pre-implantation human and mouse embryos can be infected with ZIKV, and propagate virus causing neural progenitor cell death. These findings are corroborated by the dose-dependent nature of ZIKV susceptibility of hESC-derived trophectoderm cells. Single blastocyst RNA-seq reveals key transcriptional changes upon ZIKV infection, including nervous system development, prior to commitment to the neural lineage. The pregnancy rate of mice is >50% lower in pre-implantation infection than infection at E4.5, demonstrating that pre-implantation ZIKV infection leads to miscarriage. Cumulatively, these data elucidate a previously unappreciated association of pre- and peri-implantation ZIKV infection and microcephal

Evaluation of the Sensitivity of Metabolic Profiling by Rapid Evaporative Ionization Mass Spectrometry:Toward More Radical Oral Cavity Cancer Resections

Radical resection for patients with oral cavity cancer remains challenging. Rapid evaporative ionization mass spectrometry (REIMS) of electrosurgical vapors has been reported for real-time classification of normal and tumor tissues for numerous surgical applications. However, the infiltrative pattern of invasion of oral squamous cell carcinomas (OSCC) challenges the ability of REIMS to detect low amounts of tumor cells. We evaluate REIMS sensitivity to determine the minimal amount of detected tumors cells during oral cavity cancer surgery. A total of 11 OSCC patients were included in this study. The tissue classification based on 185 REIMS ex vivo metabolic profiles from five patients was compared to histopathology classification using multivariate analysis and leave-one-patient-out cross-validation. Vapors were analyzed in vivo by REIMS during four glossectomies. Complementary desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) was employed to map tissue heterogeneity on six oral cavity sections to support REIMS findings. REIMS sensitivity was assessed with a new cell-based assay consisting of mixtures of cell lines (tumor, myoblasts, keratinocytes). Our results depict REIMS classified tumor and soft tissues with 96.8% accuracy. In vivo REIMS generated intense mass spectrometric signals. REIMS detected 10% of tumor cells mixed with 90% myoblasts with 83% sensitivity and 82% specificity. DESI-MSI underlined distinct metabolic profiles of nerve features and a metabolic shift phosphatidylethanolamine PE(O-16:1/18:2))/cholesterol sulfate common to both mucosal maturation and OSCC differentiation. In conclusion, the assessment of tissue heterogeneity with DESI-MSI and REIMS sensitivity with cell mixtures characterized sensitive metabolic profiles toward in vivo tissue recognition during oral cavity cancer surgeries

Isogenic human trophectoderm cells demonstrate the role of NDUFA4 and associated variants in ZIKV infection

Summary: Population-based genome-wide association studies (GWAS) normally require a large sample size, which can be labor intensive and costly. Recently, we reported a human induced pluripotent stem cell (hiPSC) array-based GWAS method, identifying NDUFA4 as a host factor for Zika virus (ZIKV) infection. In this study, we extended our analysis to trophectoderm cells, which constitute one of the major routes of mother-to-fetus transmission of ZIKV during pregnancy. We differentiated hiPSCs from various donors into trophectoderm cells. We then infected cells carrying loss of function mutations in NDUFA4, harboring risk versus non-risk alleles of SNPs (rs917172 and rs12386620) or having deletions in the NDUFA4 cis-regulatory region with ZIKV. We found that loss/reduction of NDUFA4 suppressed ZIKV infection in trophectoderm cells. This study validated our published hiPSC array-based system as a useful platform for GWAS and confirmed the role of NDUFA4 as a susceptibility locus for ZIKV in disease-relevant trophectoderm cells