Simulated microgravity triggers a membrane adaptation to stress in E. coli REL606.

Investigating the evolution of Escherichia coli in microgravity offers valuable insights into microbial adaptation to extreme environments. Here the effects of simulated microgravity (SµG) on gene expression and genome evolution of E. coli REL606, a strain evolved terrestrially for 35 years, is explored.

Future of the Search for Life: Workshop Report.

The 2-week, virtual Future of the Search for Life science and engineering workshop brought together more than 100 scientists, engineers, and technologists in March and April 2022 to provide their expert opinion on the interconnections between life-detection science and technology. Participants identified the advances in measurement and sampling technologies they believed to be necessary to perform searches for life elsewhere in our Solar System, 20 years or more in the future. Among suggested measurements for these searches, those pertaining to three potential indicators of life termed "dynamic disequilibrium," "catalysis," and "informational polymers" were identified as particularly promising avenues for further exploration.

EcAMSat spaceflight measurements of the role of σ in antibiotic resistance of stationary phase Escherichia coli in microgravity.

We report the results of the EcAMSat (Escherichia coli Antimicrobial Satellite) autonomous space flight experiment, investigating the role of σ in the development of antibiotic resistance in uropathogenic E. coli (UPEC) in microgravity (µ-g). The presence of σ, encoded by the rpoS gene, has been shown to increase antibiotic resistance in Earth gravity, but it was unknown if this effect occurs in µ-g.

Payload hardware and experimental protocol development to enable future testing of the effect of space microgravity on the resistance to gentamicin of uropathogenic Escherichia coli and its σ-deficient mutant.

Human immune response is compromised and bacteria can become more antibiotic resistant in space microgravity (MG). We report that under low-shear modeled microgravity (LSMMG), stationary-phase uropathogenic Escherichia coli (UPEC) become more resistant to gentamicin (Gm), and that this increase is dependent on the presence of σ (a transcription regulator encoded by the rpoS gene). UPEC causes urinary tract infections (UTIs), reported to afflict astronauts; Gm is a standard treatment, so these findings could impact astronaut health.

Microgravity validation of a novel system for RNA isolation and multiplex quantitative real time PCR analysis of gene expression on the International Space Station.

The International Space Station (ISS) National Laboratory is dedicated to studying the effects of space on life and physical systems, and to developing new science and technologies for space exploration. A key aspect of achieving these goals is to operate the ISS National Lab more like an Earth-based laboratory, conducting complex end-to-end experimentation, not limited to simple microgravity exposure. Towards that end NASA developed a novel suite of molecular biology laboratory tools, reagents, and methods, named WetLab-2, uniquely designed to operate in microgravity, and to process biological samples for real-time gene expression analysis on-orbit.

Effect of spaceflight on Pseudomonas aeruginosa final cell density is modulated by nutrient and oxygen availability.

Background: Abundant populations of bacteria have been observed on Mir and the International Space Station. While some experiments have shown that bacteria cultured during spaceflight exhibit a range of potentially troublesome characteristics, including increases in growth, antibiotic resistance and virulence, other studies have shown minimal differences when cells were cultured during spaceflight or on Earth. Although the final cell density of bacteria grown during spaceflight has been reported for several species, we are not yet able to predict how different microorganisms will respond to the microgravity environment.

Spaceflight promotes biofilm formation by Pseudomonas aeruginosa.

Understanding the effects of spaceflight on microbial communities is crucial for the success of long-term, manned space missions. Surface-associated bacterial communities, known as biofilms, were abundant on the Mir space station and continue to be a challenge on the International Space Station. The health and safety hazards linked to the development of biofilms are of particular concern due to the suppression of immune function observed during spaceflight.

The O/OREOS mission: first science data from the Space Environment Survivability of Living Organisms (SESLO) payload.

We report the first telemetered spaceflight science results from the orbiting Space Environment Survivability of Living Organisms (SESLO) experiment, executed by one of the two 10 cm cube-format payloads aboard the 5.5 kg Organism/Organic Exposure to Orbital Stresses (O/OREOS) free-flying nanosatellite. The O/OREOS spacecraft was launched successfully to a 72° inclination, 650 km Earth orbit on 19 November 2010.

Media ion composition controls regulatory and virulence response of Salmonella in spaceflight.

The spaceflight environment is relevant to conditions encountered by pathogens during the course of infection and induces novel changes in microbial pathogenesis not observed using conventional methods. It is unclear how microbial cells sense spaceflight-associated changes to their growth environment and orchestrate corresponding changes in molecular and physiological phenotypes relevant to the infection process. Here we report that spaceflight-induced increases in Salmonella virulence are regulated by media ion composition, and that phosphate ion is sufficient to alter related pathogenesis responses in a spaceflight analogue model.

Interactions between CCAAT enhancer binding protein delta and estrogen receptor alpha control insulin-like growth factor I (igf1) and estrogen receptor-dependent gene expression in osteoblasts.

Although ambient levels of estradiol and synthesis of the osteoblast growth factor IGF-I are inversely related in vivo, estradiol has little or no direct effect on igf1 gene expression in rat osteoblasts in vitro. Rather, estradiol suppresses the effect of hormones that enhance igf1 expression through protein kinase A dependent activation of CCAAT enhancer binding protein (C/EBP) transcription factors. We show here that inhibition of C/EBP activity by estradiol relates to the level of estrogen receptor alpha (ERalpha) expression, and that a complex between hormone-activated ERalpha and C/EBPdelta inhibits transcription by each factor.

Transcriptional and post-transcriptional regulation of transforming growth factor beta type II receptor expression in osteoblasts.

Variations in transforming growth factor beta (TGF-beta) activity depend on the expression of specific receptors in normal as well as transformed cells. For example, in addition to mutations in TGF-beta type II receptor (TbetaRII) that abrogate normal TGF-beta function, its expression decreases during the transition from replication to extracellular matrix production, or in response to other growth regulators in bone. Therefore, to understand how TbetaRII expression is controlled, we cloned the rat TbetaRII gene promoter and defined basic aspects of its structure and activity.