Microbiology of human spaceflight: microbial responses to mechanical forces that impact health and habitat sustainability.

SUMMARYUnderstanding the dynamic adaptive plasticity of microorganisms has been advanced by studying their responses to extreme environments. Spaceflight research platforms provide a unique opportunity to study microbial characteristics in new extreme adaptational modes, including sustained exposure to reduced forces of gravity and associated low fluid shear force conditions. Under these conditions, unexpected microbial responses occur, including alterations in virulence, antibiotic and stress resistance, biofilm formation, metabolism, motility, and gene expression, which are not observed using conventional experimental approaches.

Aging and putative frailty biomarkers are altered by spaceflight.

Human space exploration poses inherent risks to astronauts' health, leading to molecular changes that can significantly impact their well-being. These alterations encompass genomic instability, mitochondrial dysfunction, increased inflammation, homeostatic dysregulation, and various epigenomic changes. Remarkably, these changes bear similarities to those observed during the aging process on Earth.

The interplay between lncRNAs, RNA-binding proteins and viral genome during SARS-CoV-2 infection reveals strong connections with regulatory events involved in RNA metabolism and immune response.

Viral infections are complex processes based on an intricate network of molecular interactions. The infectious agent hijacks components of the cellular machinery for its profit, circumventing the natural defense mechanisms triggered by the infected cell. The successful completion of the replicative viral cycle within a cell depends on the function of viral components versus the cellular defenses.

Measuring Spatial and Temporal Oxygen Flux Near Plant Tissues Using a Self-Referencing Optrode.

Self-referencing optrodic microsensing is a noninvasive method for measuring oxygen transport into/from tissues. The sensing mechanism is based on fluorescence quenching by molecular oxygen at the tip of a fiber-optic probe, and facilitates microscale spatial mapping and continuous monitoring at 100-350 mHz sampling frequency. Over the last decade, this technique has been applied for plant tissues, including roots, seeds, leaves, and flowers in both liquid and air.

An assessment of US microbiome research.

Genome-enabled technologies have supported a dramatic increase in our ability to study microbial communities in environments and hosts. Taking stock of previously funded microbiome research can help to identify common themes, under-represented areas and research priorities to consider moving forward. To assess the status of US microbiome research, a team of government scientists conducted an analysis of federally funded microbiome research.

Sodium channel Nax is a regulator in epithelial sodium homeostasis.

The mechanisms by which the epidermis responds to disturbances in barrier function and restores homeostasis are unknown. With a perturbation of the epidermal barrier, water is lost, resulting in an increase in extracellular sodium concentration. We demonstrate that the sodium channel Nax functions as a sodium sensor.

Hydration status regulates sodium flux and inflammatory pathways through epithelial sodium channel (ENaC) in the skin.

Although it is known that the inflammatory response that results from disruption of epithelial barrier function after injury results in excessive scarring, the upstream signals remain unknown. It has also been observed that epithelial disruption results in reduced hydration status and that the use of occlusive dressings that prevent water loss from wounds decreases scar formation. We hypothesized that hydration status changes sodium homeostasis and induces sodium flux in keratinocytes, which result in activation of pathways responsible for keratinocyte-fibroblast signaling and ultimately lead to activation of fibroblasts.

Glutathione-gated potassium efflux as a mechanism of active biofilm detachment.

Biofilm detachment often has detrimental effects such as pipe obstruction and infection, yet the detachment mechanisms underlying dispersal remain largely unknown. In this study, a stress response mechanism known as glutathione-gated potassium efflux (GGKE) was evaluated as an active detachment mechanism in the dispersal of Pseudomonas aeruginosa biofilms. N-ethylmaleimide (NEM) was used to activate potassium efflux proteins (Kef) associated with the GGKE pathway.

Comparative study of non-invasive methods for assessing Daphnia magna embryo toxicity.

Embryos, unlike adults, are typically sessile, which allows for an increase in the available metrics that can be used to assess chemical toxicity. We investigate Daphnia magna development rate and oxygen consumption as toxicity metrics and compare them to arrested embryo development using four different techniques with potassium cyanide (KCN) as a common toxicant. The EC50 (95 % CI) for arrested development was 2,535 (1,747-3,677) μg/L KCN.

Single-stranded DNA functionalized single-walled carbon nanotubes for microbiosensors via layer-by-layer electrostatic self-assembly.

In this letter, the facial noncovalent adsorption of single-stranded DNA (ssDNA) provided single-walled carbon nanotubes (SWNTs) with biofunctionality while their superior properties were retained. In this case, we innovatively demonstrated the feasibility of employing the negative surface charge of ssDNA-SWNTs to realize layer-by-layer electrostatic self-assembly. On the basis of such a sandwichlike structure, an applicable glucose microbiosensor with direct electrochemistry and high performance was fabricated.

Mouse and human islets survive and function after coating by biosilicification.

Inorganic materials have properties that can be advantageous in bioencapsulation for cell transplantation. Our aim was to engineer a hybrid inorganic/soft tissue construct by inducing pancreatic islets to grow an inorganic shell. We created pancreatic islets surrounded by porous silica, which has potential application in the immunoprotection of islets in transplantation therapies for type 1 diabetes.

Altered glucose metabolism in Harvey-ras transformed MCF10A cells.

Metabolic reprogramming that alters the utilization of glucose including the "Warburg effect" is critical in the development of a tumorigenic phenotype. However, the effects of the Harvey-ras (H-ras) oncogene on cellular energy metabolism during mammary carcinogenesis are not known. The purpose of this study was to determine the effect of H-ras transformation on glucose metabolism using the untransformed MCF10A and H-ras oncogene transfected (MCF10A-ras) human breast epithelial cells, a model for early breast cancer progression.

Silver nanoparticle-specific mitotoxicity in Daphnia magna.

Silver nanoparticles (Ag NPs) are gaining popularity as bactericidal agents in commercial products; however, the mechanisms of toxicity (MOT) of Ag NPs to other organisms are not fully understood. It is the goal of this research to determine differences in MOT induced by ionic Ag(+) and Ag NPs in Daphnia magna, by incorporating a battery of traditional and novel methods. Daphnia embryos were exposed to sublethal concentrations of AgNO3 and Ag NPs (130-650 ng/L), with uptake of the latter confirmed by confocal reflectance microscopy.

Multi-analyte biochip (MAB) based on all-solid-state ion-selective electrodes (ASSISE) for physiological research.

Lab-on-a-chip (LOC) applications in environmental, biomedical, agricultural, biological, and spaceflight research require an ion-selective electrode (ISE) that can withstand prolonged storage in complex biological media (1-4). An all-solid-state ion-selective-electrode (ASSISE) is especially attractive for the aforementioned applications. The electrode should have the following favorable characteristics: easy construction, low maintenance, and (potential for) miniaturization, allowing for batch processing.

1,25-dihydroxyvitamin D regulation of glucose metabolism in Harvey-ras transformed MCF10A human breast epithelial cells.

This study was designed to investigate the impact of 1,25-dihydroxyvitamin D (1,25(OH)2D) on glucose metabolism during early cancer progression. Untransformed and ras-oncogene transfected (ras) MCF10A human breast epithelial cells were employed to model early breast cancer progression. 1,25(OH)2D modified the response of the ras cells to glucose restriction, suggesting 1,25(OH)2D may reduce the ras cell glucose addiction noted in cancer cells.

RNA-seq analysis identifies potential modulators of gravity response in spores of Ceratopteris (Parkeriaceae): evidence for modulation by calcium pumps and apyrase activity.

Premise Of The Study: Gravity regulates the magnitude and direction of a trans-cell calcium current in germinating spores of Ceratopteris richardii. Blocking this current with nifedipine blocks the spore's downward polarity alignment, a polarization that is fixed by gravity ∼10 h after light induces the spores to germinate. RNA-seq analysis at 10 h was used to identify genes potentially important for the gravity response.

Non-invasive flux measurements using microsensors: theory, limitations, and systems.

Knowledge of the fluxes of ions and neutral molecules across the outer membrane or boundary of living tissues and cells is an important strand of applied molecular biology. Such fluxes can be measured non-invasively with good resolution in time and space. Two systems (MIFE™ and SIET) have been developed and have become widely used to implement this technique, and they are commercially available.

Nanomaterial based self-referencing microbiosensors for cell and tissue physiology research.

Physiological studies require sensitive tools to directly quantify transport kinetics in the cell/tissue spatial domain under physiological conditions. Although biosensors are capable of measuring concentration, their applications in physiological studies are limited due to the relatively low sensitivity, excessive drift/noise, and inability to quantify analyte transport. Nanomaterials significantly improve the electrochemical transduction of microelectrodes, and make the construction of highly sensitive microbiosensors possible.

An aqueous media based approach for the preparation of a biosensor platform composed of graphene oxide and Pt-black.

The combination of Pt nanoparticles and graphene was more effective in enhancing biosensing than either nanomaterial alone according to previous reports. Based on the structural similarities between water soluble graphene oxide (GrO(x)) and graphene, we report the fabrication of an aqueous media based GrO(x)/Pt-black nanocomposite for biosensing enhancement. In this approach GrO(x) acted as a nanoscale molecular template for the electrodeposition of Pt-black, an amorphously nanopatterned isoform of platinum metal.

Abnormal mitochondrial function impairs calcium influx in diabetic mouse pancreatic beta cells.

Background: Abnormal insulin secretion of pancreatic beta cells is now regarded as the more primary defect than the insulin function in the etiology of type 2 diabetes. Previous studies found impaired mitochondrial function and impaired Ca(2+) influx in beta cells in diabetic patients and animal models, suggesting a role for these processes in proper insulin secretion. The aim of this study was to investigate the detailed relationship of mitochondrial function, Ca(2+) influx, and defective insulin secretion.

Mechanical stretch induced calcium efflux from bone matrix stimulates osteoblasts.

The mechanisms by which bone cells sense critically loaded regions of bone are still a matter of ongoing debate. Animal models to investigate response to microdamage involve post mortem immunohistological analysis and do not allow real-time monitoring of cellular response during the emergence of the damage in bone. Most in vitro mechanical stimulation studies are conducted on non-bone substrates, neglecting the damage-related alterations in the pericellular niche and their potential effects on bone cells.

Microbiosensors based on DNA modified single-walled carbon nanotube and Pt black nanocomposites.

Glucose and ATP biosensors have important applications in diagnostics and research. Biosensors based on conventional materials suffer from low sensitivity and low spatial resolution. Our previous work has shown that combining single-walled carbon nanotubes (SWCNTs) with Pt nanoparticles can significantly enhance the performance of electrochemical biosensors.

A comparative study of enzyme immobilization strategies for multi-walled carbon nanotube glucose biosensors.

This work addresses the comparison of different strategies for improving biosensor performance using nanomaterials. Glucose biosensors based on commonly applied enzyme immobilization approaches, including sol-gel encapsulation approaches and glutaraldehyde cross-linking strategies, were studied in the presence and absence of multi-walled carbon nanotubes (MWNTs). Although direct comparison of design parameters such as linear range and sensitivity is intuitive, this comparison alone is not an accurate indicator of biosensor efficacy, due to the wide range of electrodes and nanomaterials available for use in current biosensor designs.

Non-invasive tools for measuring metabolism and biophysical analyte transport: self-referencing physiological sensing.

Biophysical phenomena related to cellular biochemistry and transport are spatially and temporally dynamic, and are directly involved in the regulation of physiology at the sub-cellular to tissue spatial scale. Real time monitoring of transmembrane transport provides information about the physiology and viability of cells, tissues, and organisms. Combining information learned from real time transport studies with genomics and proteomics allows us to better understand the functional and mechanistic aspects of cellular and sub-cellular systems.