• Home
  • NASA
  • Space Biosciences Division
  • Ruth K. Globus
Ruth K. Globus

Ruth K. Globus
NASA · Space Biosciences Division

About

102
Publications
21,934
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
5,395
Citations
Citations since 2016
21 Research Items
2117 Citations
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400

Publications

Publications (102)
Article
Full-text available
As human space exploration advances to establish a permanent presence beyond the Low Earth Orbit (LEO) with NASA’s Artemis mission, researchers are striving to understand and address the health challenges of living and working in the spaceflight environment. Exposure to ionizing radiation, microgravity, isolation and other spaceflight hazards pose...
Article
Full-text available
Spaceflight causes cardiovascular changes due to microgravity-induced redistribution of body fluids and musculoskeletal unloading. Cardiac deconditioning and atrophy on Earth are associated with altered Trp53 and oxidative stress-related pathways, but the effects of spaceflight on cardiac changes at the molecular level are less understood. We teste...
Article
Full-text available
Isolation on Earth can alter physiology and signaling of organs systems, including the central nervous system. Although not in complete solitude, astronauts operate in an isolated environment during spaceflight. In this study, we determined the effects of isolation and simulated microgravity solely or combined, on the inflammatory cytokine milieu o...
Article
Full-text available
Long duration spaceflight poses potential health risks to astronauts during flight and re-adaptation after return to Earth. There is an emerging need for NASA to provide successful and reliable therapeutics for long duration missions when capability for medical intervention will be limited. Clinically relevant, human placenta-derived therapeutic st...
Article
Full-text available
A comprehensive understanding of spaceflight factors involved in immune dysfunction and the evaluation of biomarkers to assess in-flight astronaut health are essential goals for NASA. An elevated neutrophil-to-lymphocyte ratio (NLR) is a potential biomarker candidate, as leukocyte differentials are altered during spaceflight. In the reduced gravity...
Article
Full-text available
Accumulation of oxidative damage from excess reactive oxygen species (ROS) may contribute to skeletal aging and mediate adverse responses to physiological challenges. Wildtype (WT) and transgenic mice (male, 16 weeks of age) with human catalase targeted to the mitochondria (mCAT) were analyzed for skeletal responses to the remodeling stimuli of com...
Article
Full-text available
Spaceflight is a unique environment that includes at least two factors which can negatively impact skeletal health: microgravity and ionizing radiation. We have previously shown that a diet supplemented with dried plum powder (DP) prevented radiation-induced bone loss in mice. In this study, we investigated the capacity of the DP diet to prevent bo...
Article
Full-text available
Animal models are useful for exploring the health consequences of prolonged spaceflight. Capabilities were developed to perform experiments in low earth orbit with on-board sample recovery, thereby avoiding complications caused by return to Earth. For NASA’s Rodent Research-1 mission, female mice (ten 32 wk C57BL/6NTac; ten 16 wk C57BL/6J) were lau...
Article
Full-text available
A round-trip human mission to Mars is anticipated to last roughly three years. Spaceflight conditions are known to cause loss of bone mineral density (BMD) in astronauts, increasing bone fracture risk. There is an urgent need to understand BMD progression as a function of spaceflight time to minimize associated health implications and ensure missio...
Article
Full-text available
The hindlimb unloading (HU) model has been used extensively to simulate the cephalad fluid shift and musculoskeletal disuse observed in spaceflight with its application expanding to study immune, cardiovascular and central nervous system responses, among others. Most HU studies are performed with singly housed animals, although social isolation als...
Article
Full-text available
Spaceflight entails exposure to numerous environmental challenges with the potential to contribute to both musculoskeletal and vascular dysfunction. The purpose of this review is to describe current understanding of microgravity and radiation impacts on the mammalian skeleton and associated vasculature at the level of the whole organism. Recent exp...
Article
Full-text available
Space radiation may pose a risk to skeletal health during subsequent aging. Irradiation acutely stimulates bone remodeling in mice, although the long-term influence of space radiation on bone-forming potential (osteoblastogenesis) and possible adaptive mechanisms are not well understood. We hypothesized that ionizing radiation impairs osteoblastoge...
Article
Full-text available
Background: Even with recent scientific advancements, challenges posed by limited resources and capabilities at the time of sample dissection continue to limit the collection of high quality tissues from experiments that can be conducted only infrequently and at high cost, such as in space. The resources and time it takes to harvest tissues post-e...
Data
Supplemental File for Data Availability. Data sets for this study are fully available without restriction. (PDF)
Article
Full-text available
As multiple spacefaring nations contemplate extended manned missions to Mars and the Moon, health risks could be elevated as travel goes beyond the Earth's protective magnetosphere into the more intense deep space radiation environment. The primary purpose of this study was to determine whether mortality rates due to cardiovascular disease (CVD), c...
Article
Full-text available
Bone loss caused by ionizing radiation is a potential health concern for radiotherapy patients, radiation workers and astronauts. In animal studies, exposure to ionizing radiation increases oxidative damage in skeletal tissues, and results in an imbalance in bone remodeling initiated by increased bone-resorbing osteoclasts. Therefore, we evaluated...
Article
Full-text available
Weightlessness during spaceflight leads to functional changes in resistance arteries and loss of cancellous bone, which may be potentiated by radiation exposure. The purpose of this study was to assess the effects of hindlimb unloading (HU) and total-body irradiation (TBI) on the vasomotor responses of skeletal muscle arteries. Male C57BL/6 mice we...
Article
Full-text available
The rodent hindlimb unloading (HU) model was developed in the 1980's to make it possible to study possible mechanisms, responses and treatments for the adverse consequences of spaceflight. Decades before development of the HU model, weightlessness was predicted to yield deficits in the principal tissues responsible for structure and movement on Ear...
Article
Full-text available
Current knowledge of stem cell characteristics, maintenance and renewal, evolution with age, location in 'niches', and radiosensitivity to acute and protracted exposures is reviewed regarding haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. The identity of the target cells for carcinogenesis continues to point t...
Article
Full-text available
Spaceflight has profound effects on vascular function as a result of weightlessness that may be further compounded by radiation exposure. The purpose of the present study was to assess the individual and combined effects of hindlimb unloading (HU) and radiation (Rad) on vasodilator responses in the skeletal muscle vasculature. Adult male C57BL/6J m...
Article
Full-text available
Mechanical unloading in microgravity is thought to induce tissue degeneration by various mechanisms, including inhibition of regenerative stem cell differentiation. To address this hypothesis, we investigated the effects of microgravity on early lineage commitment of mouse embryonic stem cells (mESCs) using the embryoid body (EB) model of tissue di...
Article
During spaceflight, astronauts will be exposed to a complex mixture of ionizing radiation that poses a risk to their health. Exposure of rodents to ionizing radiation on Earth causes bone loss and increases osteoclasts in cancellous tissue, but also may cause persistent damage to stem cells and osteoprogenitors. We hypothesized that ionizing radiat...
Article
Full-text available
Exposure to ionizing radiation can cause rapid mineral loss and increase bone-resorbing osteoclasts within metabolically active, cancellous bone tissue leading to structural deficits. To better understand mechanisms involved in rapid, radiation-induced bone loss, we determined the influence of total body irradiation on expression of select cytokine...
Article
Current knowledge of stem cell characteristics, maintenance and renewal, evolution with age, location in ‘niches’, and radiosensitivity to acute and protracted exposures is reviewed regarding haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. The identity of the target cells for carcinogenesis continues to point t...
Article
Full-text available
Despite considerable progress in identifying health risks to crewmembers related to exposure to galactic/cosmic rays (GCR) and solar particle events (SPE) during space travel, its long-term effects on the pulmonary system are unknown. We used a murine risk projection model to investigate the impact of exposure to space-relevant radiation (SR) on th...
Article
Full-text available
Mechanical loading of mammalian tissues is a potent promoter of tissue growth and regeneration, whilst unloading in microgravity can cause reduced tissue regeneration, possibly through effects on stem cell tissue progenitors. To test the specific hypothesis that mechanical unloading alters differentiation of bone marrow mesenchymal and hematopoieti...
Article
Full-text available
Fracture healing in animal models has been shown to be altered in both ground based analogs of spaceflight and in those exposed to actual spaceflight. The molecular mechanisms behind altered fracture healing as a result of chronic exposure to microgravity remain to be elucidated. This study investigates temporal gene expression of multiple factors...
Article
Full-text available
The Mark III Rodent Habitat Workshop was held at NASA Ames Research Center on March 21-22, 2013 to prepare top-level science requirements for developing a habitat to support studies of mammalian reproduction and development on the International Space Station (ISS). This timely workshop assembled a diverse team with expertise in reproductive and dev...
Article
Full-text available
Bone is a dynamically remodeled tissue that requires gravity-mediated mechanical stimulation for maintenance of mineral content and structure. Homeostasis in bone occurs through a balance in the activities and signaling of osteoclasts, osteoblasts, and osteocytes, as well as proliferation and differentiation of their stem cell progenitors. Microgra...
Chapter
Full-text available
The redox environment impacts normal stem cell niches throughout the body. Hematopoietic, muscle, and neural stem cell compartments respond to changes in reactive oxygen (ROS) and nitrogen (RNS) species by triggering signaling networks that impact cellular proliferation, survival, and differentiation. Work from many labs including our own has found...
Article
Full-text available
Osteoporosis can profoundly affect the aged as a consequence of progressive bone loss; high-dose ionizing radiation can cause similar changes, although less is known about lower doses (≤100 cGy). We hypothesized that exposure to relatively low doses of gamma radiation accelerates structural changes characteristic of skeletal aging. Mice (C57BL/6J-1...
Article
To determine the chronic effects of heavy ion irradiation, an antibody based proteomic microarray technology was applied to monitor alterations in the serum proteome, six months after whole body irradiation of adult male C57Bl/6 mice with 0.5 Gray of (56)Fe. Out of 507 proteins, irradiation reduced expression of 25 proteins and enhanced expression...
Conference Paper
The mechanism of bone degradation in response to aging has been the focus of many osteoporosis studies. However, there are other factors that contribute to bone degradation, including radiation. People exposed to abnormally high levels of radiation, including astronauts and cancer patients undergoing radiation therapy, have an increased risk of ost...
Article
Full-text available
Spaceflight causes a negative calcium balance and loss of skeletal mass selectively in those bones that are normally loaded on earth. This bone loss can be quite severe in some individuals, posing a potential risk for astronauts in space, during initial recovery on earth, and with subsequent aging. Over the past 25 years, substantive advances in gr...
Article
Astronauts are exposed to both musculoskeletal disuse and heavy ion radiation in space. Disuse alters the magnitude and direction of forces placed upon the skeleton causing bone remodeling, while energy deposited by ionizing radiation causes free radical formation and can lead to DNA strand breaks and oxidative damage to tissues. Radiation and disu...
Article
Space travel and prolonged bed rest cause bone loss due to musculoskeletal disuse. In space, radiation fields may also have detrimental consequences because charged particles traversing the tissues of the body can elicit a wide range of cytotoxic and genotoxic lesions. The effects of heavy-ion radiation exposure in combination with musculoskeletal...
Article
Full-text available
Exposure of astronauts in space to radiation during weightlessness may contribute to subsequent bone loss. Gamma irradiation of postpubertal mice rapidly increases the number of bone-resorbing osteoclasts and causes bone loss in cancellous tissue; similar changes occur in skeletal diseases associated with oxidative stress. Therefore, we hypothesize...
Article
Unweighting the hindlimbs of a rat by tail suspension leads to a decrease in bone in the unweighted hindlimbs, but not in the normally weighted forelimbs. We evaluated whether increments in dietary calcium could prevent this. Growing rats were fed diets ranging in calcium content from 0.1% to 2.4%. After the rats were suspended for two weeks, we fo...
Article
Ionizing radiation can cause substantial tissue degeneration, which may threaten the long-term health of astronauts and radiotherapy patients. To determine whether a single dose of radiation acutely compromises structural integrity in the postpubertal skeleton, 18-week-old male mice were exposed to (137)Cs gamma radiation (1 or 2 Gy). The structure...
Article
The mammalian skeleton adjusts bone structure and strength in response to changes in mechanical loading, however the molecular and cellular mechanisms governing this process in vivo are unknown. Terminally differentiated osteoblasts, the osteocytes, are presumptive mechanosensory cells for bone, and cell culture studies demonstrate that beta1 integ...
Conference Paper
Full-text available
I. Abstract Since 1994, the NASA Ames Research Center has hosted an annual space settlement design contest for 6-12th grade students. Thousands of students and hundreds of teachers from around the world have involved themselves in space settlement, including environmental and life support systems, some devoting months of intense effort. Prize winne...
Article
The adaptation of the skeleton to changes in mechanical loading depends on the ability of bone cells first to detect then to convert diverse mechanical forces into chemical signals that regulate cell behavior, a process known as mechanotransduction. A network of interactions between the extracellular matrix, integrin receptors that span the cell me...
Article
Astronauts are exposed to radiation during space travel under conditions of dramatically reduced weightbearing activity. However, we know little about how gravity-dependent loading affects tissue sensitivity to radiation. We hypothesize gravity-dependent loading and irradiation share common molecular signaling pathways in bone cell progenitors that...
Article
Purpose of review: Unloading models provide opportunities to understand the skeletal physiology of space flight and to address basic science questions regarding skeletal adaptation to reduced mechanical stimuli. This review highlights data from the past year on skeletal disuse from clinical studies (space flight and ground-based models) and animal...
Article
Cells respond to a wide range of mechanical stimuli such as fluid shear and strain, although the contribution of gravity to cell structure and function is not understood. We hypothesized that bone-forming osteoblasts are sensitive to increased mechanical loading by hypergravity. A centrifuge suitable for cell culture was developed and validated, an...
Article
Full-text available
The study was designed to determine whether beta1-integrin plays a role in mediating the acute skeletal response to mechanical unloading. Transgenic (TG) mice were generated to express a dominant negative form of beta1-integrin under the control of the osteocalcin promoter, which targets expression of the transgene to mature osteoblasts. At 63 days...
Article
Full-text available
The hindlimb unloading rodent model is used extensively to study the response of many physiological systems to certain aspects of space flight, as well as to disuse and recovery from disuse for Earth benefits. This chapter describes the evolution of hindlimb unloading, and is divided into three sections. The first section examines the characteristi...
Article
Skeletal modeling entails the deposition of large amounts of extracellular matrix (ECM) to form structures tailored to withstand increasing mechanical loads during rapid growth. Specific ECM molecules bind to integrin receptors on the cell surface, thereby triggering a cascade of signaling events that affect critical cell functions. To evaluate the...
Article
Life on Earth has evolved under the continuous influence of gravity (1-g). As humans explore and develop space, however, we must learn to adapt to an environment with little or no gravity. Studies indicate that lack of weightbearing for vertebrates occurring with immobilization, paralysis, or in a microgravity environment may cause muscle and bone...