Preclinical Drug Testing in Scalable 3D Engineered Muscle Tissues.

Accurately modeling healthy and disease conditions in vitro is vital for the development of new treatment strategies and therapeutics. For cardiac and skeletal muscle diseases, contractile force and kinetics constitute key metrics for assessing muscle function. New and improved methods for generating engineered muscle tissues (EMTs) from induced pluripotent stem cells have made in vitro disease modeling more reliable for contractile tissues; however, reproducibly fabricating tissues from suspended cell cultures and measuring their contractility is challenging.

Knock-Down of HDAC2 in Human Induced Pluripotent Stem Cell Derived Neurons Improves Neuronal Mitochondrial Dynamics, Neuronal Maturation and Reduces Amyloid Beta Peptides.

Histone deacetylase 2 (HDAC2) is a major HDAC protein in the adult brain and has been shown to regulate many neuronal genes. The aberrant expression of HDAC2 and subsequent dysregulation of neuronal gene expression is implicated in neurodegeneration and brain aging. Human induced pluripotent stem cell-derived neurons (hiPSC-Ns) are widely used models for studying neurodegenerative disease mechanisms, but the role of HDAC2 in hiPSC-N differentiation and maturation has not been explored.

Advances and Current Challenges Associated with the Use of Human Induced Pluripotent Stem Cells in Modeling Neurodegenerative Disease.

One of the most profound advances in the last decade of biomedical research has been the development of human induced pluripotent stem cell (hiPSC) models for identification of disease mechanisms and drug discovery. Human iPSC technology has the capacity to revolutionize healthcare and the realization of personalized medicine, but differentiated tissues derived from stem cells come with major criticisms compared to native tissue, including variability in genetic backgrounds, a lack of functional maturity, and differences in epigenetic profiles. It is widely believed that increasing complexity will lead to improved clinical relevance, so methods are being developed that go from a single cell type to various levels of 2-D coculturing and 3-D organoids.

Physiological Aβ Concentrations Produce a More Biomimetic Representation of the Alzheimer's Disease Phenotype in iPSC Derived Human Neurons.

Alzheimer's disease (AD) is characterized by slow, progressive neurodegeneration leading to severe neurological impairment, but current drug development efforts are limited by the lack of robust, human-based disease models. Amyloid-β (Aβ) is known to play an integral role in AD progression as it has been shown to interfere with neurological function. However, studies into AD pathology commonly apply Aβ to neurons for short durations at nonphysiological concentrations to induce an exaggerated dysfunctional phenotype.

Leptomeninges-Derived Induced Pluripotent Stem Cells and Directly Converted Neurons From Autopsy Cases With Varying Neuropathologic Backgrounds.

Patient-specific stem cell technology from skin and other biopsy sources has transformed in vitro models of neurodegenerative disease, permitting interrogation of the effects of complex human genetics on neurotoxicity. However, the neuropathologic changes that underlie cognitive and behavioral phenotypes can only be determined at autopsy. To better correlate the biology of derived neurons with age-related and neurodegenerative changes, we generated leptomeningeal cell lines from well-characterized research subjects that have undergone comprehensive postmortem neuropathologic examinations.

Morphological and functional characterization of human induced pluripotent stem cell-derived neurons (iCell Neurons) in defined culture systems.

Pre-clinical testing of drug candidates in animal models is expensive, time-consuming, and often fails to predict drug effects in humans. Industry and academia alike are working to build human-based in vitro test beds and advanced high throughput screening systems to improve the translation of preclinical results to human drug trials. Human neurons derived from induced pluripotent stems cells (hiPSCs) are readily available for use within these test-beds and high throughput screens, but there remains a need to robustly evaluate cellular behavior prior to their incorporation in such systems.

Microphysiological systems and low-cost microfluidic platform with analytics.

A multiorgan, functional, human in vitro assay system or 'Body-on-a-Chip' would be of tremendous benefit to the drug discovery and toxicology industries, as well as providing a more biologically accurate model for the study of disease as well as applied and basic biological research. Here, we describe the advances our team has made towards this goal, as well as the most pertinent issues facing further development of these systems. Description is given of individual organ models with appropriate cellular functionality, and our efforts to produce human iterations of each using primary and stem cell sources for eventual incorporation into this system.

Growth of Serratia liquefaciens under 7 mbar, 0°C, and CO2-enriched anoxic atmospheres.

Twenty-six strains of 22 bacterial species were tested for growth on trypticase soy agar (TSA) or sea-salt agar (SSA) under hypobaric, psychrophilic, and anoxic conditions applied singly or in combination. As each factor was added to multi-parameter assays, the interactive stresses decreased the numbers of strains capable of growth and, in general, reduced the vigor of the strains observed to grow. Only Serratia liquefaciens strain ATCC 27592 exhibited growth at 7 mbar, 0°C, and CO2-enriched anoxic atmospheres.

Effects of simulated Mars conditions on the survival and growth of Escherichia coli and Serratia liquefaciens.

Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions.