Monodelphis domestica Induced Pluripotent Stem Cells Reveal Metatherian Pluripotency Architecture

Marsupials have been a powerful comparative model to understand mammalian biology. However, because of the unique characteristics of their embryology, marsupial pluripotency architecture remains to be fully understood, and nobody has succeeded in developing embryonic stem cells (ESCs) from any marsupial species. We have developed an integration-free iPSC reprogramming method and established validated iPSCs from two inbred strains of a marsupial, Monodelphis domestica. The monoiPSCs showed a significant (6181 DE-genes) and highly uniform (r2 [95% CI] = 0.973 ± 0.007) resetting of the cellular transcriptome and were similar to eutherian ESCs and iPSCs in their overall transcriptomic profiles. However, monoiPSCs showed unique regulatory architecture of the core pluripotency transcription factors and were more like marsupial epiblasts. Our results suggest that POU5F1 and the splice-variant-specific expression of POU5F3 synergistically regulate the opossum pluripotency gene network. It is plausible that POU5F1, POU5F3 splice variant XM_016427856.1, and SOX2 form a self-regulatory network. NANOG expression, however, was specific to monoiPSCs and epiblasts. Furthermore, POU5F1 was highly expressed in trophectoderm cells, whereas all other pluripotency transcription factors were significantly downregulated, suggesting that the regulatory architecture of core pluripotency genes of marsupials may be distinct from that of eutherians

Short-range charge-order in RRNiO3_{3} perovskites (RR=Pr,Nd,Eu) probed by X-ray absorption spectroscopy

The short-range organization around Ni atoms in orthorhombic $R$NiO$_{3}$ ($R$=Pr,Nd,Eu) perovskites has been studied over a wide temperature range by Ni K-edge x-ray absorption spectroscopy. Our results demonstrate that two different Ni sites, with different average Ni-O bond lengths, coexist in those orthorhombic compounds and that important modifications in the Ni nearest neighbors environment take place across the metal-insulator transition. We report evidences for the existence of short-range charge-order in the insulating state, as found in the monoclinic compounds. Moreover, our results suggest that the two different Ni sites coexists even in the metallic state. The coexistence of two different Ni sites, independently on the $R$ ion, provides a common ground to describe these compounds and shed new light in the understanding of the phonon-assisted conduction mechanism and unusual antiferromagnetism present in all $R$NiO$_{3}$ compounds.Comment: 4 pages, 3 figures, accepted PRB - Brief Report Dec.200

An Exploratory Study of Methicillin-Resistant Staphylococcus aureus and SCCmec Elements Obtained from a Community Setting Along the Texas Border with Mexico

An exploratory study of methicillin-resistant Staphylococcus aureus (MRSA) and SCCmec elements in bacteria along the Mexican border of south Texas was performed. Between September and December of 2008, 375 swabs of anterior nares were self-collected by students attending the University of Texas-Pan American (UTPA) and cultured for MRSA. Fifty seven bacterial isolates were kept for further analysis that included suspected MRSA and other SCCmec-containing bacteria. Isolates were examined for the presence of nuc, mecA, lukS-PV, and spa genes using PCR. SCCmec and spa typing were also performed. Seven S. aureus isolates were found of which six were classified as MRSA. SCCmec typing showed five of the six MRSA strains to be type IV, while one MRSA strain, and most of the non-S. aureus strains, were untypeable, producing results that were indicative of mixed SCCmec types. Five of the six MRSA strains contained known spa types (two of which corresponded to USA300 and one to USA600), while one strain had a novel spa type. Only one isolate, a USA300 MRSA, was positive for lukS-PV. Easy access by the Texas border community to antibiotics in Mexico without a prescription, and the strong partition in SCCmec types between MRSA and non-S. aureus bacteria suggest that this border region of Texas may be uniquely suited for the study of emerging SCCmec types, their horizontal transfer, and perhaps other aspects of antibiotic resistance in bacteria

Neurocellular ER Stress Response in Alzheimer\u27s Disease and Related Dementias (ADRD) Risk

Background: Alzheimer’s Disease (AD) pathology, characterized by neurodegeneration, amyloid-β (Aβ) plaques, and intracellular tangles of hyperphosphorylated Tau, starts in the entorhinal cortex and then spreads to the hippocampus and cerebral cortex. The presence of AD pathology in the hippocampus is strongly correlated with cognitive decline. The hippocampus is also one of the major sites of adult neurogenesis in the brain and accumulating evidence now suggests that adult hippocampal neurogenesis (AHN) that occurs throughout life (albeit declining with age) is essential for cellular homeostasis and hippocampus-dependent cognitive functions, and is severely impaired in ADRD patients. However, the causation of impaired AHN in ADRD patients and its contribution to ADRD-related cognitive decline remains poorly understood. Studies of postmortem AD brain showed elevated levels of endoplasmic reticulum (ER) stress. While the accumulation of Aβ and intracellular neurofibrillary tangles may primarily contribute to ER stress by disruption of Ca2+ and protein homeostasis and the resulting unfolded protein response (UPR) potentially alters AHN by mechanisms yet to be fully understood. Methods: To study the ER stress-associated neurocellular response and its effects on neurocellular homeostasis and neurogenesis, we performed ER stress challenge using Thapsigargin (TG), a specific inhibitor of sarco/endoplasmic reticulum Ca2+ ATPase (SERCA), on induced pluripotent stem cell (iPSC) derived neural stem cells (NSCs) of two individuals of our Mexican American Family Study (MAFS). We have previously shown that our iPSC-derived NSCs are transcriptionally akin to dorsal neuroepithelium that give rise to the majority of the central nervous system and are a relevant cell type to study developmental and adult neurogenesis. Both pre- and post-ER stress-challenged NSCs were multi-dimensionally phenotyped by quantitative high-content screening and genome-wide mRNA sequencing (mRNAseq) analysis. Results: The high-content phenotypic analysis of the pre- and post-ER stress-challenged NSCs shows evidence of upregulated UPR, a decline in NSC proliferation, an increase in apoptosis, and cellular oxidative stress in post-ER stress-challenged NSCs. A total of 2,300 genes were significantly (moderated t statistics FDR corrected p-value ≤ 0.05 and Fold Change absolute ≥ 2.0) differentially expressed (DE) between pre- and post-ER stress-challenged NSCs. The DE genes showed significant enrichment in protein export, DNA replication, protein processing in ER, cell cycle, and apoptosis KEGG pathways. All three UPR-associated (PERK, ATF6, and IRE1) pathways were significantly upregulated. Due to the short G1 phase, activated NSCs rely on higher expression of CDT1 and CDC6 licensing factors and MCM complex for timely DNA duplication during the cell cycle, ER stress-induced activation of UPR down-regulated CDT1 licensing factor and MCM complex genes in ER stress-challenged NSCs and induced G1 phase cell cycle arrest. The ER stress-challenged NSCs also showed activation of CHOP-mediated apoptosis and down-regulation of neurotransmitter homeostasis and synaptic plasticity-associated genes. Conclusions: Overall our results suggest that ER stress-associated attenuation of NSC self-renewal, increased apoptosis, and dysregulated neurotransmitter homeostasi

Non-alcoholic fatty liver disease and hepatocellular carcinoma risk associated gene expression phenotypes in Hispanics

Background: Non-alcoholic fatty liver disease (NAFLD) is a state of metabolic dysregulation characterized by excessive lipid accumulation into the hepatocytes (hepatic steatosis). It is a major determinant of risk for hepatocellular carcinoma (HCC). Hispanics in south Texas exhibit one of the highest incidences of NAFLD and HCC in the United States. Methods: We used an induced pluripotent stem cell (iPSC) based hepatocyte (HEP) model to identify high lipid stress induced transcriptomic changes in HEPs to better understand hepatic steatosis associated HCC risk. Well-characterized, iPSC differentiated functional HEPs generated from six participants in our San Antonio Mexican American family study were challenged with high lipid conditions in in-vitro culture. The lipid challenged and vehicle treated HEPs were then analyzed for cellular lipid accumulation, fibrosis, and genome wide gene expression by mRNA-sequencing. Results: Quantitative measures of cellular neutral lipids and fibrosis marker (COL1A1) were significantly increased in lipid challenged HEPs. These measures also showed a high correlation (r2 ≥70%) with individual’s in-vivo liver fat. Genome wide differential gene expression analysis identified 78 genes that were significantly differentially expressed (DE) between lipid challenged and vehicle treated HEPs. Functional annotation analysis showed significant enrichment of DE genes in liver hyperplasia/hyperproliferation functions (27 genes; p-value 2.0x10-2 to 9.2x10-2), and included several genes (PDRG1, PLIN2, CFHR3, ANXA2P3, HBA1, HBA2, HBB) whose altered expression was shown to be associated with HCC risk. Conclusions: We have identified several genes associated with risk for HCC for which expression was significantly dysregulated by a high lipid stress challenge in HEPs

Inhibition of neddylation represses lipopolysaccharide-induced proinflammatory cytokine production in macrophage cells

Background: Lipopolysaccharides (LPSs) up-regulate proinflammatory cytokines in macrophages, partly through a NF-κB-dependent process. Results: Blocking neddylation, which helps regulate NF-κB, represses LPS-induced up-regulation of proinflammatory cytokines. Conclusion: Neddylation plays a role in the up-regulation of NF-κB-regulated proinflammatory cytokines produced by macrophages in response to LPS. Significance: Inhibition of neddylation represents a novel and effective method for the prevention of LPS-induced proinflammatory cytokines

Statistical validation of Aeolus L2A particle backscatter coefficient retrievals over ACTRIS/EARLINET stations on the Iberian Peninsula

The Global Observing System (GOS) has encountered some limitations due to a lack of worldwide real-time wind measurements. In this context, the European Space Agency (ESA) has developed the Aeolus satellite mission, based on the ALADIN (Atmospheric Laser Doppler Instrument) Doppler wind lidar; this mission aims to obtain near-real-time wind retrievals at the global scale. As spin-off products, the instrument retrieves aerosol optical properties such as particle backscatter and extinction coefficients. In this work, a validation of Aeolus reprocessed (baseline 10) co-polar backscatter coefficients ( part Aeolus) is presented through an intercomparison with analogous ground-based measurements taken at the ACTRIS (Aerosols, Clouds and Trace gases Research InfraStructure Network)/EARLINET (European Aerosol Research Lidar Network) stations of Granada (Spain), Évora (Portugal) and Barcelona (Spain) over the period from July 2019 until October 2020. Case studies are first presented, followed by a statistical analysis. The stations are located in a hot spot between Africa and the rest of Europe, which guarantees a variety of aerosol types, from mineral dust layers to continental/anthropogenic aerosol, and allows us to test Aeolus performance under different scenarios. The so called Aeolus-like profiles ( part Aeolus like;355) are obtained from total particle backscatter coefficient and linear particle depolarization ratio ( part linear) profiles at 355 and 532 nm measured from the surface, through a thorough bibliographic review of dual-polarization measurements for relevant aerosol types. Finally, the study proposes a relation for the spectral conversion of part linear, which is implemented in the Aeolus-like profile calculation. The statistical results show the ability of the satellite to detect and characterize significant aerosol layers under cloud-free conditions, along with the surface effect on the lowermost measurements, which causes the satellite to largely overestimate copolar backscatter coefficients. Finally, the Aeolus standard correct algorithm middle bin (SCAmb) shows a better agreement with ground-based measurements than the standard correct algorithm (SCA), which tends to retrieve negative and meaningless coefficients in the clear troposphere. The implementation of Aeolus quality flags entails a vast reduction in the number of measurements available for comparison, which affects the statistical significance of the results

Advance in the conceptual design of the European DEMO magnet system

The European DEMO, i.e. the demonstration fusion power plant designed in the framework of the Roadmap to Fusion Electricity by the EUROfusion Consortium, is approaching the end of the pre-conceptual design phase, to be accomplished with a Gate Review in 2020, in which all DEMO subsystems will be reviewed by panels of independent experts. The latest 2018 DEMO baseline has major and minor radius of 9.1 m and 2.9 m, plasma current 17.9 MA, toroidal field on the plasma axis 5.2 T, and the peak field in the toroidal-field (TF) conductor 12.0 T. The 900 ton heavy TF coil is prepared in four lowerature-superconductor (LTS) variants, some of them differing slightly, other significantly, from the ITER TF coil design. Two variants of the CS coils are investigated - a purely LTS one resembling the ITER CS, and a hybrid coil, in which the innermost layers made of HTS allow the designers either to increase the magnetic flux, and thus the duration of the fusion pulse, or to reduce the outer radius of the CS coil. An issue presently investigated by mechanical analyzes is the fatigue load. Two variants of the poloidal field coils are being investigated. The magnet and conductor design studies are accompanied by the experimental tests on both LTS and HTS prototype samples, covering a broad range of DC and AC tests. Testing of quench behavior of the 15 kA HTS cables, with size and layout relevant for the fusion magnets and cooled by forced flow helium, is in preparation.</p

Activating Transcription Factor 4 Modulates TGFβ-Induced Aggressiveness in Triple-Negative Breast Cancer via SMAD2/3/4 and mTORC2 Signaling

Purpose: On the basis of the identified stress-independent cellular functions of activating transcription factor 4 (ATF4), we reported enhanced ATF4 levels in MCF10A cells treated with TGFβ1. ATF4 is overexpressed in patients with triple-negative breast cancer (TNBC), but its impact on patient survival and the underlying mechanisms remain unknown. We aimed to determine ATF4 effects on patients with breast cancer survival and TNBC aggressiveness, and the relationships between TGFβ and ATF4. Defining the signaling pathways may help us identify a cell signaling-tailored gene signature.Experimental Design: Patient survival data were determined by Kaplan-Meier analysis. Relationship between TGFβ and ATF4, their effects on aggressiveness (tumor proliferation, metastasis, and stemness), and the underlying pathways were analyzed in three TNBC cell lines and in vivo using patient-derived xenografts (PDX).Results: ATF4 overexpression correlated with TNBC patient survival decrease and a SMAD-dependent crosstalk between ATF4 and TGFβ was identified. ATF4 expression inhibition reduced migration, invasiveness, mammosphere-forming efficiency, proliferation, epithelial-mesenchymal transition, and antiapoptotic and stemness marker levels. In PDX models, ATF4 silencing decreased metastases, tumor growth, and relapse after chemotherapy. ATF4 was shown to be active downstream of SMAD2/3/4 and mTORC2, regulating TGFβ/SMAD and mTOR/RAC1-RHOA pathways independently of stress. We defined an eight-gene signature with prognostic potential, altered in 45% of 2,509 patients with breast cancer.Conclusions: ATF4 may represent a valuable prognostic biomarker and therapeutic target in patients with TNBC, and we identified a cell signaling pathway-based gene signature that may contribute to the development of combinatorial targeted therapies for breast cancer