Selected Grantee Publications
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- 64 results found
- Cardiovascular
- Stem Cells/Regenerative Medicine
Generation of SIV-Resistant T Cells and Macrophages from Nonhuman Primate Induced Pluripotent Stem Cells with Edited CCR5 Locus
D’Souza et al., Stem Cell Reports. 2022.
https://www.doi.org/10.1016/j.stemcr.2022.03.003
Genetically modified T cells have shown promise as a potential therapy for HIV. A renewable source of T cells from induced pluripotent stem cells (iPSCs) could help to further research progress in this area. The researchers used Mauritian cynomolgus macaques to generate simian immunodeficiency virus (SIV)–resistant T cells and macrophages from iPSCs. These engineered cells demonstrated impaired capacity for differentiation into CD4+CD8+ T cells. T cells and macrophages from the edited iPSCs did not support SIV replication. These findings could be applied to the development of new HIV therapies. Supported by ORIP (R24OD021322, P51OD011106) and NHLBI.
A Novel Wireless ECG System for Prolonged Monitoring of Multiple Zebrafish for Heart Disease and Drug Screening Studies
Le et al., Biosensors and Bioelectronics. 2022.
https://pubmed.ncbi.nlm.nih.gov/34801796/
Zebrafish and their mutant lines have been extensively used in cardiovascular studies. In the current study, the novel system Zebra II is presented for prolonged electrocardiogram (ECG) acquisition and analysis for multiple zebrafish within controllable working environments. The Zebra II is composed of a perfusion system, apparatuses, sensors, and an in-house electronic system. First, the Zebra II is validated in comparison with a benchmark system, namely iWORX, through various experiments. The validation displayed comparable results in terms of data quality and ECG changes in response to drug treatment. The effects of anesthetic drugs and temperature variation on zebrafish ECG were subsequently investigated in experiments that need real-time data assessment. The Zebra II's capability of continuous anesthetic administration enabled prolonged ECG acquisition up to 1 h compared to that of 5 min in existing systems. The novel cloud-based automated analysis with data obtained from four fish further provided a useful solution for combinatorial experiments and helped save significant time and effort. The system showed robust ECG acquisition and analytics for various applications, including arrhythmia in sodium-induced sinus arrest, temperature-induced heart rate variation, and drug-induced arrhythmia in Tg(SCN5A-D1275N) mutant and wildtype fish. The multiple channel acquisition also enabled the implementation of randomized controlled trials on zebrafish models. The developed ECG system holds promise and solves current drawbacks in order to greatly accelerate drug screening applications and other cardiovascular studies using zebrafish. Supported by ORIP (R44OD024874) and NHLBI.
HDAC Inhibitor Titration of Transcription and Axolotl Tail Regeneration
Voss et al., Frontiers in Cell and Development Biology. 2021.
https://pubmed.ncbi.nlm.nih.gov/35036404/
New patterns of gene expression are enacted and regulated during tissue regeneration. Romidepsin, an FDA-approved HDAC inhibitor, potently blocks axolotl embryo tail regeneration by altering initial transcriptional responses to injury. Regeneration inhibitory concentrations of romidepsin increased and decreased the expression of key genes. Single-nuclei RNA sequencing at 6 HPA illustrated that key genes were altered by romidepsin in the same direction across multiple cell types. These results implicate HDAC activity as a transcriptional mechanism that operates across cell types to regulate the alternative expression of genes that associate with regenerative success versus failure outcomes. Supported by ORIP (P40OD019794, R24OD010435, R24OD021479), NICHD, and NIGMS.
Negative Inotropic Mechanisms of β-cardiotoxin in Cardiomyocytes by Depression of Myofilament ATPase Activity without Activation of the Classical β-Adrenergic Pathway
Lertwanakarn et al., Scientific Reports. 2021.
https://www.nature.com/articles/s41598-021-00282-x
Beta-cardiotoxin (β-CTX) from the king cobra venom (Ophiophagus hannah) was previously proposed as a novel β-adrenergic blocker. However, the involvement of β-adrenergic signaling by this compound has never been elucidated. The objectives of this study were to investigate the underlying mechanisms of β-CTX as a β-blocker and its association with the β-adrenergic pathway. Healthy Sprague Dawley rats were used for cardiomyocytes isolation. In summary, the negative inotropic mechanism of β-CTX was discovered. β-CTX exhibits an atypical β-blocker mechanism. These properties of β-CTX may benefit in developing a novel agent aid to treat hypertrophic cardiomyopathy. Supported by ORIP (P40OD010960) and NHLBI.
Integrated Spatial Multiomics Reveals Fibroblast Fate During Tissue Repair
Foster et al., PNAS. 2021.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8521719/
The function of regenerative medicine in wound healing remains elusive, partially because of how fibroblasts program and respond to injury remains unclear. Investigators presented a multimodal -omics platform for the comprehensive study of cell populations in complex tissue, which allowed characterization of cells involved in wound healing across time and space. Through integrated analysis of single cell chromatin landscapes and gene expression states, coupled with spatial transcriptomic profiling, fibroblast epigenomes were imputed with temporospatial resolution. This allowed revelation of potential mechanisms controlling fibroblast fate during migration, proliferation, and differentiation following skin injury, and reexamination of the canonical phases of wound healing. Supported by ORIP (S10OD018220) and others.
Limited Expansion of Human Hepatocytes in FAH/RAG2-Deficient Swine
Nelson et al., Tissue Engineering – Part A. 2021.
https://pubmed.ncbi.nlm.nih.gov/34309416/
The mammalian liver's regenerative ability has led researchers to engineer animals as incubators for expansion of human hepatocytes. Nelson et al. engineered immunodeficient swine to support expansion of human hepatocytes and identify barriers to their clinical application. Immunodeficient swine were engineered by knockout of the recombinase-activating gene 2 (RAG2) and fumarylacetoacetate hydrolase (FAH). Immature human hepatocytes (ihHCs) were injected into fetal swine by intrauterine cell transplantation (IUCT) at day 40 of gestation. They identified the mechanism of the eventual graft rejection by the intact NK cell population. They confirmed the presence of residual adaptive immunity in this model of immunodeficiency. Supported by ORIP (U42OD011140).
MIC-Drop: A Platform for Large-scale In Vivo CRISPR Screens
Parvez et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/34413171/
CRISPR screens in animals are challenging because generating, validating, and keeping track of large numbers of mutant animals is prohibitive. These authors introduce Multiplexed Intermixed CRISPR Droplets (MIC-Drop), a platform combining droplet microfluidics, single-needle en masse CRISPR ribonucleoprotein injections, and DNA barcoding to enable large-scale functional genetic screens in zebrafish. In one application, they showed that MIC-Drop could identify small-molecule targets. Furthermore, in a MIC-Drop screen of 188 poorly characterized genes, they discovered several genes important for cardiac development and function. With the potential to scale to thousands of genes, MIC-Drop enables genome-scale reverse genetic screens in model organisms. Supported by ORIP (R24OD017870), NIGMS, and NHLBI.
A Noncoding RNA Modulator Potentiates Phenylalanine Metabolism in Mice
Li et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/34353949/
The role of long noncoding RNAs (lncRNAs) in phenylketonuria (PKU), an inherited disorder causing build-up of an amino acid causing brain problems, is unknown. Investigators demonstrated that the mouse lncRNA Pair and human lncRNA HULC associate with phenylalanine hydroxylase (PAH). Pair-knockout mice exhibited phenotypes that faithfully models human PKU, such as excessive blood phenylalanine (Phe), growth retardation, and progressive neurological symptoms. HULC depletion led to reduced PAH enzymatic activities in human induced pluripotent stem cell-differentiated hepatocytes (i.e., that have the capacity to self-renew by dividing). To develop a strategy for restoring liver lncRNAs, these investigators designed lncRNA mimics that exhibit liver enrichment. Treatment with these mimics reduced excessive Phe in Pair -/- and PAH R408W/R408W mice and improved the Phe tolerance of these mice. Supported by ORIP (S10OD012304) and others.
Effects of Early Daily Alcohol Exposure on Placental Function and Fetal Growth in a Rhesus Macaque Model
Lo et al., American Journal of Obstetrics and Gynecology. 2021.
https://www.sciencedirect.com/science/article/pii/S0002937821008309?via%3Dihub=
In a rhesus macaque model for chronic prenatal alcohol exposure, daily consumption during early pregnancy significantly diminished placental perfusion at mid to late gestation and significantly decreased the oxygen supply to the fetal vasculature throughout pregnancy. These findings were associated with the presence of microscopic placental infarctions. Although placental adaptations may compensate for early environmental perturbations to fetal growth, placental blood flow and oxygenation were reduced, consistent with the evidence of placental ischemic injury that persisted throughout pregnancy. Supported by ORIP (P51OD011092), NICHD, and NIAAA.
Deep Learning-Based Framework for Cardiac Function Assessment in Embryonic Zebrafish from Heart Beating Videos
Naderi et al., Computers in Biology and Medicine. 2021.
https://www.sciencedirect.com/science/article/pii/S0010482521003590
Zebrafish is a powerful model system for a host of biological investigations, cardiovascular studies, and genetic screening. However, the current methods for quantifying and monitoring zebrafish cardiac functions involve tedious manual work and inconsistent estimations. Naderi et al. developed a Zebrafish Automatic Cardiovascular Assessment Framework (ZACAF) based on a U-net deep learning model for automated assessment of cardiovascular indices, such as ejection fraction (EF) and fractional shortening (FS) from microscopic videos of wildtype and cardiomyopathy mutant zebrafish embryos. The framework could be widely applicable with any laboratory resources, and the automatic feature holds promise to enable efficient, consistent, and reliable processing and analysis capacity. Supported by ORIP (R44OD024874)