Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “assays”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Biological Data for Deep Space Mission Support

Increased biomedical risks and challenges associated with deep space missions (cis-Lunar, Mars transit, Mars surface) require new knowledge discovery and development of novel ecosystem and biomedical support capabilities. This paradigm shift supporting distant and long-duration missions requires biological data to be findable, accessible, interoperable, reusable (FAIR), and maximally open-access (i.e., there is a data governance continuum from closed to mediated to embargoed to open). The NASA “Open Science Data Repositories” (OSDR) aims to meet scientific, technical, and operational spaceflight needs, and offers the ability to upload, download, search, share, analyze, and visualize data across physiological, behavioral, ‘omics, and environmental monitoring telemetry datasets. OSDR includes NASA GeneLab, NASA Ames Life Sciences Data Archive (ALSDA), and NASA Biological Institutional Scientific Collection (NBISC). In the past year, ALSDA has undergone a transformation in its data collection, curation, and architecture methods. Standardizing non-genomic (phenotypic) datasets was, and will continue to be, a challenge because of their diverse nature (e.g., molecular, cellular, tissue, whole organism behavior; micro-computed tomography, intraocular pressure, fluorescence microscopy, western blot, ultrasonography; tabular, images, video). This year ALSDA, alongside GeneLab, introduced the Biological Data Management Environment (BDME) with the purpose to accept submission of data from space relevant experiments including spaceflight, radiation, simulated gravity, gravitropism, isolation and confinement, hostile closed environments and/or distance from Earth. In addition to bringing together omics, phenotypic, physiological, bioimaging, and behavioral data into one repository. By integrating with GeneLab a multi-project submission portal aims to reduce the burden on PIs submitting data and enabling the discovery of both omics and phenotypic data. The purpose of ALSDA is to collect, curate, and make all non-human space-relevant biological data maximally findable, accessible, interoperable, and reusable (FAIR). These scope of ALSDA data collected and submitted by PIs include study design metadata, subject metadata, assay metadata (parameters), raw and processed assay data, assay imagery/video, and subject-experienced mission data telemetry (radiation, temperature, humidity, acoustics, vibrations, etc.). In 2021, a community of researchers rallied to form the ALSDA Analysis Working Group (AWG) and provided scientific consensus on dataset sample and assay metadata. The community and excitement around the ALSDA/OSDR system has already led to several data reuse studies, demonstrating value using machine learning (ML), knowledge graphs, and meta-analysis approaches.

space biology↗
NASA NTRSDate not supplied

Biological Data for Deep Space Mission Support

Increased biomedical risks and challenges associated with deep space missions (cis-Lunar, Mars transit, Mars surface) require new knowledge discovery and development of novel ecosystem and biomedical support capabilities. This paradigm shift supporting distant and long-duration missions requires biological data to be findable, accessible, interoperable, reusable (FAIR), and maximally open-access (i.e., there is a data governance continuum from closed to mediated to embargoed to open). The NASA “Open Science Data Repositories” (OSDR) aims to meet scientific, technical, and operational spaceflight needs, and offers the ability to upload, download, search, share, analyze, and visualize data across physiological, behavioral, ‘omics, and environmental monitoring telemetry datasets. OSDR includes NASA GeneLab, NASA Ames Life Sciences Data Archive (ALSDA), and NASA Biological Institutional Scientific Collection (NBISC). In the past year, ALSDA has undergone a transformation in its data collection, curation, and architecture methods. Standardizing non-genomic (phenotypic) datasets was, and will continue to be, a challenge because of their diverse nature (e.g., molecular, cellular, tissue, whole organism, behavior; micro-computed tomography, intraocular pressure, fluorescence microscopy, western blot, ultrasonography; tabular, images, video). This year ALSDA, alongside GeneLab, introduced the Biological Data Management Environment (BDME) with the purpose to accept submission of data from space relevant experiments including spaceflight, radiation, simulated gravity, gravitropism, isolation and confinement, hostile closed environments and/or distance from Earth. In addition to bringing together omics, phenotypic, physiological, bioimaging, and behavioral data into one repository. By integrating with GeneLab a multi-project submission portal aims to reduce the burden on PIs submitting data and enabling the discovery of both omics and phenotypic data. The purpose of ALSDA is to collect, curate, and make all non-human space-relevant biological data maximally findable, accessible, interoperable, and reusable (FAIR). These scope of ALSDA data collected and submitted by PIs include study design metadata, subject metadata, assay metadata (parameters), raw and processed assay data, assay imagery/video, and subject-experienced mission data telemetry (radiation, temperature, humidity, acoustics, vibrations, etc.). In 2021, a community of researchers rallied to form the ALSDA Analysis Working Group (AWG) and provided scientific consensus on dataset sample and assay metadata. The community and excitement around the ALSDA/OSDR system has already led to several data reuse studies, demonstrating value using machine learning (ML), knowledge graphs, and meta-analysis approaches.

space biology↗
NASA NTRSDate not supplied

Enabling Model Organism and Commercial Astronaut Data Access Through the NASA Open Science Data Repository

NASA’s Open Science Data Repository (OSDR) brings together omics data from NASA’s GeneLab project and non-omics data, including physiological, phenotypic, imaging, and behavioral data from NASA’s Ames Life Sciences Data Archive (ALSDA) collected from decades of space biology research, providing open and FAIR (findable, accessible, interoperable, and reusable) access of these precious data to scientists world-wide. This rich source of meticulously curated metadata and data from spaceflight and analog studies has been mined by the scientific community resulting in dozens of high impact scientific publications that reveals a complex network of molecular and physiological effects of spaceflight across living systems, from microbes to plants, to mammals. Understanding how these effects translate to the human condition is critical as we move deeper into the era of commercial space travel. However, the integration of data, specifically omics data, from astronauts is particularly challenging due to their sensitive nature. OSDR has risen to this challenge by developing a mechanism to control access to identifiable levels of omics data, such as raw sequence data, while enabling public access to processed, unidentifiable, data and associated metadata that will allow the scientific community to interrogate human astronaut data alongside data from model organisms to begin answering these critical questions. The 2021 SpaceX Inspiration4 (I4) mission collected a comprehensive atlas of biological measurements from four civilian astronauts, providing a wealth of data to characterize the effects of spaceflight on the human body. These data include both non-omics and omics assays such as direct RNA sequencing (RNA-seq), single nuclei ATAC-seq and RNA-seq, metagenomics, proteomics, and comprehensive metabolic and cytokine panels, all of which have been integrated into the OSDR system across no less than 9 studies. Each study has been carefully curated using community-backed OSDR standards for sample and assay level metadata ensuring these data are findable and accessible. In addition to hosting both raw and processed data from the principal investigator team for each assay type, the GeneLab team plans to re-process the I4 omics data using GeneLab’s standard processing pipelines. The GeneLab processed data outputs will allow for comparisons across studies on OSDR and enable visualization of these data through the OSDR data visualization platform thereby enabling data reusability and interoperability. Here we describe the robust privacy and security protocols implemented by OSDR to safeguard sensitive health data from astronauts while facilitating metadata and processed data sharing for research purposes. We further provide a road map for navigating the vast amount of data provided for each I4 study on the OSDR, including experimental design, associated experiments, payloads, and missions, data generation and analysis protocols, and associated scientific articles. Additionally, we illustrate how to interrogate the standardized metadata provided in the sample and assay tables as well as various means to download and access the data including programmatically through the GeneLab Open API (GLOpenAPI). The open access of datasets in NASA’s OSDR provides a unique opportunity for the scientific community, as well as citizen scientists and students, to continue using OSDR resources to further unlock profound insights into the consequences of space travel on the human body. Through implementation of security measures to protect sensitive human data, the OSDR seeks to strengthen the science exchange between the Biological and Physical Sciences Program and the Human Research Program, per recommendation 4-1 of the 2023-2032 Decadal Survey, and encourage further sharing and dissemination of astronaut data to provide the scientific community with the resources needed to lay the groundwork for developing targeted mitigation strategies to help withstand the rigors of long-duration spaceflight.

Amanda Marie Saravia-butler↗
NASA NTRSDate not supplied

Enabling Model Organism and Commercial Astronaut Data Access Through the NASA Open Science Data Repository

NASA’s Open Science Data Repository (OSDR) brings together omics data from NASA’s GeneLab project and non-omics data, including physiological, phenotypic, imaging, and behavioral data from NASA’s Ames Life Sciences Data Archive (ALSDA) collected from decades of space biology research, providing open and FAIR (findable, accessible, interoperable, and reusable) access of these precious data to scientists world-wide. This rich source of meticulously curated metadata and data from spaceflight and analog studies has been mined by the scientific community resulting in dozens of high impact scientific publications that reveals a complex network of molecular and physiological effects of spaceflight across living systems, from microbes to plants, to mammals. Understanding how these effects translate to the human condition is critical as we move deeper into the era of commercial space travel. However, the integration of data, specifically omics data, from astronauts is particularly challenging due to their sensitive nature. OSDR has risen to this challenge by developing a mechanism to control access to identifiable levels of omics data, such as raw sequence data, while enabling public access to processed, unidentifiable, data and associated metadata that will allow the scientific community to interrogate human astronaut data alongside data from model organisms to begin answering these critical questions. The 2021 SpaceX Inspiration4 (I4) mission collected a comprehensive atlas of biological measurements from four civilian astronauts, providing a wealth of data to characterize the effects of spaceflight on the human body. These data include both non-omics and omics assays such as direct RNA sequencing (RNA-seq), single nuclei ATAC-seq and RNA-seq, metagenomics, proteomics, and comprehensive metabolic and cytokine panels, all of which have been integrated into the OSDR system across no less than 9 studies. Each study has been carefully curated using community-backed OSDR standards for sample and assay level metadata ensuring these data are findable and accessible. In addition to hosting both raw and processed data from the principal investigator team for each assay type, the GeneLab team plans to re-process the I4 omics data using GeneLab’s standard processing pipelines. The GeneLab processed data outputs will allow for comparisons across studies on OSDR and enable visualization of these data through the OSDR data visualization platform thereby enabling data reusability and interoperability. Here we describe the robust privacy and security protocols implemented by OSDR to safeguard sensitive health data from astronauts while facilitating metadata and processed data sharing for research purposes. We further provide a road map for navigating the vast amount of data provided for each I4 study on the OSDR, including experimental design, associated experiments, payloads, and missions, data generation and analysis protocols, and associated scientific articles. Additionally, we illustrate how to interrogate the standardized metadata provided in the sample and assay tables as well as instructions for how to download and access the data. The I4 datasets described here re present the first ever comprehensive collection of commercial astronaut data.

Amanda M Saravia-Butler↗
DOE OSTI2023

Small molecule inhibitors for treatment of alpha viruses

An in vitro assay was designed to measure the activity of the alphavirus non-structural protein 2 (nsP2), which is the viral protease and is required for viral replication. By taking advantage of fluorescence-resonance energy transfer between two proteins, a protease cleavage assay was generated. This was utilized for high-throughput screening of 40,000 small molecules. Inhibitors were validated using cell-based assays to measure alphavirus infection and cytotoxicity. Certain compounds were then characterized for anti-viral efficacy in various cell lines in numerous assays. Compounds were tested against Chikungunya virus, Venezuelan Equine Encephalitis virus, Rift Valley Fever virus, and Zika virus. Three compounds (compounds I, II, and III) showed pan-alphavirus anti-viral efficacy at concentrations that did not result in cell toxicity. An additional compound, structure IV, showed broad spectrum inhibition of all viruses tested. Pharmaceutical preparations and methods of treatment including these compounds are provided herein.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

In-field alpha spectrometry system for uranium enrichment verification of uranium hexafluoride

A portable In-Field Alpha Spectrometry (IFAS) system was developed to support on-site uranium enrichment determination for samples taken at facilities working with gaseous UF 6 . It consists of a modified commercial alpha spectrometer, a vacuum pump, a laptop computer, and associated connectors and cables. The IFAS uses specially designed Single-Use Destructive Assay (SUDA) samplers to capture gaseous UF 6 and convert and store it as UO 2 F 2 in a thin-film zeolite. To examine the quantitative performance of the IFAS system a large number of replicate SUDA samples was acquired for natural uranium (NU, 0.72 wt%, 23 samples), low enriched uranium 1 (LEU1, 2.33 wt% 235 U, 10 samples), and low enriched uranium 2 (LEU2, 4.62 wt% 235 U, 10 samples). The standard deviation (SD) values for uranium enrichment determination with the IFAS for NU, LEU1, and LEU2, in 20-hour assays, were 0.037 wt% 235 U, 0.063 wt% 235 U, and 0.072 wt% 235 U, respectively. In addition, a separate analysis suggests that comparable SD values can be achieved in less time, approximately 8-10 hours. For context, these SD values are well below the International Atomic Energy Agency’s International Target Values for the determination of uranium enrichment in non-destructive assay measurements.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Screening method for Enzyme-based liquefaction of corn stover pellets at high solids

Liquefaction of high solid loadings of unpretreated corn stover pellets has been demonstrated with rheology of the resulting slurries enabling mixing and movement within biorefinery bioreactors. However, some forms of pelleted stover do not readily liquefy, so it is important to screen out lots of unsuitable pellets before processing is initiated. This work reports a laboratory assay that rapidly assesses whether pellets have the potential for enzyme-based liquefaction at high solids loadings. Twenty-eight pelleted corn stover (harvested at the same time and location) were analyzed using 20 mL enzyme solutions (3 FPU cellulase/ g biomass) at 30 % w/v solids loading. Imaging together with measurement of reducing sugars were performed over 24-hours. Further, some samples formed concentrated slurries of 300 mg/mL (dry basis) in the small-scale assay, which was later confirmed in an agitated bioreactor. Also, the laboratory assay showed potential for optimizing enzyme formulations that could be employed for slurry formation.

Laboratory assay↗
DOE OSTI2021

Analytical characterization of laser induced plasmas towards uranium isotopic analysis in gaseous uranium hexafluoride

To perform direct enrichment assay on gaseous uranium hexafluoride (UF 6 ) with laser induced breakdown spectroscopy (LIBS), the dominant spectral-line features, evolution of the signal and background of the U II 424.437 nm line, and its Stark width and shift, were studied as a function of UF 6 gas pressure and pulse energy of a nanosecond Nd:YAG laser. In this work, vapor pressure of UF 6 was found to be the most important parameter for LIBS analysis of gaseous UF 6 . Spectral congestion with numerous U lines of high excitation potential was observed and signal-to-background ratio (SBR) was low for measurements with 80 Torr UF 6 . Only when both UF 6 vapor pressure and laser pulse energy were low, for example, less than 20 Torr pressure and 30 mJ pulse energy, the resultant LIBS spectra from gaseous UF 6 resembled those obtained from solid U samples. The experimental data also suggest that U and F atoms recombine back to UF 6 after the laser pulse. The U emission was found to decay fast with a persistent background signal, degrading SBR with delay time. Systematic positive biases were found for UF 6 enrichment assays performed with the 235 U– 238 U line pair at 424.412–424.437 nm, which was confirmed to be caused by self-absorption. Even with optimization of experimental parameters and incorporation of a self-absorption term into the spectral-fitting algorithm, to reduce and compensate for self-absorption, self-absorption is still a main factor limiting accurate UF 6 enrichment assay. The use of another spectral window which contains no resonance lines is a prospective solution for the self-absorption issue.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2026

High-Sensitivity DNA Aptasensors for Detecting Salivary Biomarker S100A7 in Heart Failure

Early detection of heart failure (HF) is vital for improving patient outcomes, lowering hospital readmission rates, and enabling prompt treatment. We present the first high-affinity DNA aptamer for the salivary HF biomarker S100A7 and its application in highly sensitive, noninvasive diagnostic tests. Iterative truncation of the initial 82-nt aptamer (17–82) produced a 43-nt core (17–43) with a binding affinity of 27 nM, which was further enhanced to 5.5 nM through dimerization. Biochemical and mutational studies confirmed that 17–43 adopts a G-quadruplex structure, which is essential for S100A7 recognition and resistance to enzymatic degradation in human saliva. Incorporating 17–43 into sandwich aptamer-ELISA and hybrid aptamer–antibody ELISA assays allowed detection of recombinant S100A7 in human saliva with limits of detection (LOD) of 7.4 ng mL–1 (0.6 nM) and 29 pg/mL (2.2 pM), respectively-outperforming commercial immunoassays in both sensitivity and dynamic range. The hybrid assay maintained its full performance after 2.5 months of room temperature storage. Additionally, a biolayer interferometry (BLI) sensor with 17–43 quantified S100A7 in patient saliva (n = 3), achieving a LOD of 3.2 ng mL–1 (0.3 nM) with a total assay time of less than 20 min. The aptamer’s stability, high specificity, and versatility across biosensing platforms establish it as a promising tool for noninvasive heart failure diagnostics, laying the groundwork for portable aptamer-based biosensors for multiplexed monitoring of HF biomarkers.

DNA aptamer↗
DOE OSTI2024

Nanobodies as potential tools for microbiological testing of live biotherapeutic products

Nanobodies are highly specific binding domains derived from naturally occurring single chain camelid antibodies. Live biotherapeutic products (LBPs) are biological products containing preparations of live organisms, such as Lactobacillus, that are intended for use as drugs, i.e. to address a specific disease or condition. Demonstrating potency of multi-strain LBPs can be challenging. The approach investigated here is to use strain-specific nanobody reagents in LBP potency assays. Llamas were immunized with radiation-killed Lactobacillus jensenii or L. crispatus whole cell preparations. A nanobody phage-display library was constructed and panned against bacterial preparations to identify nanobodies specific for each species. Nanobody-encoding DNA sequences were subcloned and the nanobodies were expressed, purified, and characterized. Colony immunoblots and flow cytometry showed that binding by Lj75 and Lj94 nanobodies were limited to a subset of L. jensenii strains while binding by Lc38 and Lc58 nanobodies were limited to L. crispatus strains. Mass spectrometry was used to demonstrate that Lj75 specifically bound a peptidase of L. jensenii, and that Lc58 bound an S-layer protein of L. crispatus. The utility of fluorescent nanobodies in evaluating multi-strain LBP potency assays was assessed by evaluating a L. crispatus and L. jensenii mixture by fluorescence microscopy, flow cytometry, and colony immunoblots. Our results showed that the fluorescent nanobody labelling enabled differentiation and quantitation of the strains in mixture by these methods. Development of these nanobody reagents represents a potential advance in LBP testing, informing the advancement of future LBP potency assays and, thereby, facilitation of clinical investigation of LBPs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

New NDA Methods for Thorium Fuel Cycle Safeguards (Mid-Project Report)

This project is developing new Non-Destructive Assay (NDA) safeguards techniques for emergent thorium fuel cycles based on Neutron Resonance Transmission Analysis (NRTA), which can assay 233 U and 235 U when they are present together in a sample with potentially high gamma-ray backgrounds from fission products and 232 U. Existing passive techniques face large challenges for this task so new active interrogation methods are needed. This effort is also exploring how gamma-ray signatures can complement NRTA for enhanced assayed performance. This project leverages an NRTA system being developed at PNNL in collaboration with MIT, which uses a commercially available deuterium-tritium neutron generator at short standoff (~2 m). We aim to assess the feasibility and performance of these new NDA techniques for the range of relevant samples in thorium fuel cycles. Key advancements described in this mid-project report include NRTA system design for thorium safeguards measurements, characterization of 233 U oxide powder at PNNL, a survey of detector technologies suitable for NRTA in high gamma background environments, successful preliminary demonstration of a quantitative isotopic estimation algorithm, and first NRTA measurements of a thorium sample.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

LncRNA ZFAS1 promotes invasion of medullary thyroid carcinoma by enhancing EPAS1 expression via miR‐214‐3p/UCHL1 axis

Abstract lncRNA ZFAS1 was identified to facilitate thyroid cancer, but its role in medullary thyroid carcinoma (MTC) remains unknown. This study aimed to unravel the potential function of this lncRNA in MTC by investigating the involvement of the lncRNA ZFAS1 in a ceRNA network that regulates MTC invasion. Proliferation, invasion, and migration of cells were evaluated using EdU staining and Transwell assays. Immunoprecipitation (IP) assays, dual‐fluorescence reporter, and RNA IP assays were employed to examine the binding interaction among genes. Nude mice were used to explore the role of lncRNA ZFAS1 in MTC in vivo. ZFAS1 and EPAS1 were upregulated in MTC. Silencing ZFAS1 inhibited MTC cell proliferation and invasion under hypoxic conditions, which reduced EPAS1 protein levels. UCHL1 knockdown increased EPAS1 ubiquitination. ZFAS1 positively regulated UCHL1 expression by binding to miR‐214‐3p. Finally, silencing ZFAS1 significantly repressed tumor formation and metastasis in MTC. LncRNA ZFAS1 promotes invasion of MTC by upregulating EPAS1 expression via the miR‐214‐3p/UCHL1 axis.

Chen, Wenjing↗
DOE OSTI2022

Development and validation of a quantitative proton NMR method for the analysis of pregnenolone

Pregnenolone (PREG) is an endogenous steroid frequently sold as an over-the-counter dietary supplement touted to promote neurological and immunological health. While the PREG dietary supplement is added to the diet for health benefits, there are no FDA approved PREG drugs. However, compounded PREG drug products are available to U.S. patients. The FDA works with state regulatory authorities on the oversight of compounding activities, including developing 503A and 503B lists of bulk substances that compounders are permitted to use. PREG is one of the substances publicly nominated to be included on the 503B list. Compounded hormone therapies such as those using PREG are of interest given the lack of standardization in compounded drug products which may increase the possibility of underdosing, overdosing, or contamination. However, no USP monograph currently exists to evaluate the quality of PREG drug substance or product. To address knowledge gaps and assist in quality control, a simple and rapid quantitative proton nuclear magnetic resonance spectroscopy (qNMR) method for the identification and assay of PREG in different types of PREG products was developed and validated. PREG samples were characterized using 1D 1 H and 2D 1 H– 13 C HSQC NMR spectra. The qNMR assay method (taking approximately 10 min per NMR spectrum) was validated for precision, accuracy, specificity, robustness and linearity per ICH Q2(R1) guidance. The method was validated in a range from 0.032 to 3.2 mg/mL. As a proof of concept, seven PREG bulk substance samples, three tablet and two capsule PREG dietary supplements were assessed by the qNMR analytical procedure. NMR data from all tested samples met the expected criteria for identification and assay. The results demonstrate the potential of qNMR for the quality assessment of different types of PREG samples.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Cross-reactive immunogenicity of group A streptococcal vaccines designed using a recurrent neural network to identify conserved M protein linear epitopes

The M protein of group A streptococci (Strep A) is a major virulence determinant and protective antigen. The N-terminal sequence of the protein defines the more than 200 M types of Strep A and also contains epitopes that elicit opsonic antibodies, some of which cross-react with heterologous M types. Current efforts to develop broadly protective M protein-based vaccines are directed at identifying potential cross-protective epitopes located in the N-terminal regions of cluster-related M proteins for use as vaccine antigens. In this study, we have used a comprehensive approach using the recurrent neural network ABCpred and IEDB epitope conservancy analysis tools to predict 16 residue linear B-cell epitopes from 117 clinically relevant M types of Strep A (~88% of global Strep A infections). Furthermore, to examine the immunogenicity of these epitope-based vaccines, nine peptides that together shared ≥60% sequence identity with 37 heterologous M proteins were incorporated into two recombinant hybrid protein vaccines, in which the epitopes were repeated 2 or 3 times, respectively. The combined immune responses of immunized rabbits showed that the vaccines elicited significant levels of antibodies against all nine vaccine epitopes present in homologous N-terminal 1–50 amino acid synthetic M peptides, as well as cross-reactive antibodies against 16 of 37 heterologous M peptides predicted to contain similar epitopes. The epitope-specificity of the cross-reactive antibodies was confirmed by ELISA inhibition assays and functional opsonic activity was assayed in HL-60-based bactericidal assays. The results provide important information for the future design of broadly protective M protein-based Strep A vaccines.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Exosomes secreted from mesenchymal stem cells mediate the regeneration of endothelial cells treated with rapamycin by delivering pro-angiogenic microRNAs

Highlights: • MSC-derived exosomes play an important role in promoting endothelial regeneration treated with rapamycin in vitro. • A distinct class of exosomal miRNAs is identified to be tightly related to endothelial regeneration. • The therapeutic effects of MSC-exosomes may be ascribed to the delivery of pro-angiogenic miRNAs to endothelial cells. • MSC-exosomes may serve as a cell-free therapy for clinical treatment of delayed endothelial healing after DES implantation. Delayed endothelial healing after drug eluting stent (DES) implantation is a critical clinical problem in treatment of coronary artery diseases. Exosomes exhibit proangiogenic potential in a variety of ischemic diseases. However, the association of exosomes with endothelial regeneration after DES implantation has been rarely reported. In this study, we aimed to investigate the therapeutic effects of mesenchymal stem cell (MSC)-derived exosomes on endothelial cells treated with rapamycin and explore the potential mechanisms of MSC-derived exosomes in promoting endothelial regeneration. Exosomes were isolated from MSCs by ultracentrifugation and identified by transmission electron microscopy, nanoparticle tracking analysis, and Western blot assay. The in vitro effects of MSC-derived exosomes on the proliferation and migration of endothelial cells treated with rapamycin were evaluated by integrated experiment, cell counting kit-8, scratch, tube formation, and transwell assays. And the apoptosis of rapamycin-induced endothelial cells loaded with MSC-derived exosomes was detected using TUNEL and Annexin-V FITC and PI double-staining assays. The microRNA (miRNA) cargo of MSC-derived exosomes was identified by high-throughput RNA sequencing. Pro-angiogenic miRNAs and key pathways were further characterized. Our results indicated that MSC-derived exosomes could be ingested into umbilical vein endothelial cells (HUVECs) and significantly enhanced cell proliferation rate, migratory and tube-forming capabilities in vitro. MSC-derived exosomes also inhibited the apoptosis of HUVECs induced by rapamycin. A distinct class of exosomal miRNAs was further identified, including six miRNAs tightly related to neovasculogenesis. Silencing the expression of exosomal miRNA-21–5p and let-7c-5p attenuated the pro-proliferative and pro-migratory capacity of MSC-derived exosomes. Moreover, functional enrichment analysis indicated that metabolic pathways might contribute to reendothelialization. This study highlights a proregenerative effect of MSC-derived exosomes in vitro, which may be partly explained by the delivery of pro-angiogenic miRNAs to endothelial cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

High expression of Notch2 drives tongue squamous cell carcinoma carcinogenesis

Tongue squamous cell carcinoma (TSCC) is one of the most common cancers in the oral cavity. Notch signaling is frequently dysregulated in cancer. However, the role of Notch2 in TSCC is not well understood. The aim of this study was to investigate the effect of abnormal expression of Notch2 in TSCC. The expression of Notch2 was tested in 47 pairs of tissues from tongue cancer and normal samples by using immunohistochemical staining. Tongue cancer cells were transfected with siRNA or plasmid. The proliferation of the cells was tested by the CCK8 assay and colony formation assay. Subcutaneous tumor model was established to observe tumor growth. Transwell assay was used to detect the changes of cell migration and invasion ability. A humanized anti-Notch2 antibody was used to TSCC cells. We found that Notch2 was upregulated in tongue carcinoma tissues. Knocking down the expression of Notch2 by siRNA in the TSCC cell lines decreased proliferation ability both in vitro and in vivo. In addition, migration and invasion abilities were inhibited by knockdown of Notch2 in the TSCC cells. However, overexpression of Notch2 increased tongue cancer cell proliferation, invasion and migration. The humanized anti-Notch2 antibody inhibited TSCC cell growth. The results indicated that Notch2 is an oncogene in tongue squamous cell carcinoma and may become the target of a new approach for treating TSCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

LncRNA LINC00680 promotes lung adenocarcinoma growth via binding to GATA6 and canceling GATA6-mediated suppression of SOX12 expression

Lung adenocarcinoma (LUAD) is a major subtype of non-small-cell lung cancers (NSCLC). LINC00680 has been characterized as a novel oncogenic lncRNA in LUAD, but its regulatory mechanisms remain largely unclear. This study aimed to explore the subcellular localization of LINC00680 in LUAD and its regulation on the transcriptional process. LUAD cell lines (A549, H1650, and H1299) were used for in vitro and in vivo studies. Results showed LINC00680 depletion resulted in G0/G1 phase arrest of LUAD cells and reduced CDK4 and cyclin D1 expression in H1650 and H1299 cells. LINC00680 overexpression promoted A549 cell proliferation and increased CDK4 and cyclin D1 expression. RNA-fluorescence in situ hybridization (FISH) assay showed that LINC00680 has both cytoplasmic and nuclear distribution in LUAD cells. RNA pulldown and western blotting assays confirmed a physical interaction between LINC00680 and GATA6. In LUAD cells, GATA6 overexpression only slightly suppressed SOX12 transcription. ChIP-qPCR and dual-luciferase assay showed that GATA6 only weakly bound to the SOX12 promoter and decreased its activity. However, when LINC00680 was depleted, these transcriptional suppressive effects were significantly enhanced. These findings suggested that LINC00680 forms a complex with GATA6 and weakens its transcriptional suppressive effect on SOX12 expression. In the nude mice model, LINC00680 overexpression partly abrogated the growth-suppressive effects of GATA6 on A549 derived tumors. In summary, this study revealed a novel LINC00680-GATA6-SOX12 axis in promoting LUAD cell cycle progression and proliferation. Future studies should be conducted for a better understanding of the complex networking of LINC00680 in LUAD.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

ZEB1 induces non-small cell lung cancer development by targeting microRNA-320a to increase the expression of RAD51AP1

Lung cancer is the most prevalent cancer worldwide, with its mortality rate reported to be in millions annually; one of the two subtypes is non-small cell lung cancer (NSCLC). In this study, we investigated the interactions and expressions of zinc finger E-box binding homeobox 1 (ZEB1), microRNA-320a (miR-320a) and RAD51-associated protein 1 (RAD51AP1) in NSCLC tissues to determine the roles of ZEB1 in regulation of miR-320a and RAD51AP1 in the development and metastasis of NSCLC. First, the expression levels of miR-320a and ZEB1 were quantified in NSCLC tissues and cells. Transfection assay was conducted to identify the effects of miR-320a on the progression of NSCLC cells. The interaction of miR-320a with ZEB1 and RAD51AP1 was predicted and verified using dual-luciferase reporter gene assay and chromatin immunoprecipitation assay. Finally, subcutaneous xenograft tumors of 6-week mice and metastatic model tumors of 8-week mice were established to further explore the in vivo effect of miR-320a/ZEB1/RAD51AP1 on NSCLC. The findings revealed a lower expression of miR-320a in NSCLC tissues and cells, while this result was reversed regarding ZEB1 expression. ZEB1 suppressed miR-320a expression and upregulation of miR-320a resulted in the reduction of proliferation, invasion and metastasis rate of NSCLC cells, and promoted NSCLC cell apoptosis. ZEB1 promoted the expression of RAD51AP1 via inhibition of miR-320a, promoting tumor growth in vivo. ZEB1 transcriptionally inhibited the expression of miR-320a and upregulated the expression of RAD51AP1, thereby promoting metastasis in NSCLC.

60 APPLIED LIFE SCIENCES↗