Space Biosciences Division

In the Space Biosciences Division at NASA's Ames Research Center, we perform the biological research and technology development necessary to tackle the challenges of living in the extreme environments of space and to enable NASA's long-term human exploration mission. This brochure provides a broad overview for our research and development capabilities, several case study examples, and finally real-world applications and collaborative partnerships

Poziotinib Inhibits HER2-Mutant-Driven Therapeutic Resistance and Multiorgan Metastasis in Breast Cancer

UNLABELLED: The pan-HER tyrosine kinase inhibitor (TKI) neratinib is therapeutically active against metastatic breast cancers harboring activating HER2 mutations, but responses are variable and often not durable. Here we demonstrate that recurrent HER2 mutations have differential effects on endocrine therapy responsiveness, metastasis, and pan-HER TKI therapeutic sensitivity. The prevalence and prognostic significance may also depend on whether the HER2 mutant has arisen in the context of lobular versus ductal histology. The most highly recurrent HER2 mutant, L755S, was particularly resistant to neratinib but sensitive to the pan-HER TKI poziotinib, alone or in combination with fulvestrant. Poziotinib reduced tumor growth, diminished multiorgan metastasis, and inhibited mTOR activation more effectively than neratinib. Similar therapeutic effects of poziotinib were observed in both an engineered HER2L755S MCF7 model and a patient-derived xenograft harboring a HER2G778_P780dup mutation. Overall, these findings support the need for clinical evaluation of poziotinib for the treatment of HER2-mutant metastatic breast cancer. SIGNIFICANCE: Evaluation of the functional impact of HER2 mutations on therapy-induced resistance and metastasis identifies robust antitumor activity of poziotinib and supports the clinical evaluation of poziotinib in ER+ HER2 mutant breast cancer

Sustained aviremia despite anti-retroviral therapy non-adherence in male children after in utero HIV transmission

After sporadic reports of post-treatment control of HIV in children who initiated combination anti-retroviral therapy (cART) early, we prospectively studied 284 very-early-cART-treated children from KwaZulu-Natal, South Africa, after vertical HIV transmission to assess control of viremia. Eighty-four percent of the children achieved aviremia on cART, but aviremia persisting to 36 or more months was observed in only 32%. We observed that male infants have lower baseline plasma viral loads (P = 0.01). Unexpectedly, a subset (n = 5) of males maintained aviremia despite unscheduled complete discontinuation of cART lasting 3–10 months (n = 4) or intermittent cART adherence during 17-month loss to follow-up (n = 1). We further observed, in vertically transmitted viruses, a negative correlation between type I interferon (IFN-I) resistance and viral replication capacity (VRC) (P < 0.0001) that was markedly stronger for males than for females (r = −0.51 versus r = −0.07 for IFN-α). Although viruses transmitted to male fetuses were more IFN-I sensitive and of higher VRC than those transmitted to females in the full cohort (P < 0.0001 and P = 0.0003, respectively), the viruses transmitted to the five males maintaining cART-free aviremia had significantly lower replication capacity (P < 0.0001). These data suggest that viremic control can occur in some infants with in utero–acquired HIV infection after early cART initiation and may be associated with innate immune sex differences

Population health and regional variations of disease burden in Japan, 1990–2015:a systematic subnational analysis for the Global Burden of Disease Study 2015

BackgroundJapan has entered the era of super-ageing and advanced health transition, which is increasingly putting pressure on the sustainability of its health system. The level and pace of this health transition might vary across regions within Japan and concern is growing about increasing regional variations in disease burden. The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 (GBD 2015) provides a comprehensive, comparable framework. We used data from GBD 2015 with the aim to quantify the burden of disease and injuries, and to attribute risk factors in Japan at a subnational, prefecture-level.MethodsWe used data from GBD 2015 for 315 causes and 79 risk factors of death, disease, and injury incidence and prevalence to measure the burden of diseases and injuries in Japan and in the 47 Japanese prefectures from 1990 to 2015. We extracted data from GBD 2015 to assess mortality, causes of death, years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life-years (DALYs), life expectancy, and healthy life expectancy (HALE) in Japan and its 47 prefectures. We split extracted data by prefecture and applied GBD methods to generate estimates of burden, and attributable burden due to known risk factors. We examined the prefecture-level relationships of common health system inputs (eg, health expenditure and workforces) to the GBD outputs in 2015 to address underlying determinants of regional health variations.FindingsLife expectancy at birth in Japan increased by 4·2 years from 79·0 years (95% uncertainty interval [UI] 79·0 to 79·0) to 83·2 years (83·1 to 83·2) between 1990 and 2015. However, the gaps between prefectures with the lowest and highest life expectancies and HALE have widened, from 2·5 to 3·1 years and from 2·3 to 2·7 years, respectively, from 1990 to 2015. Although overall age-standardised death rates decreased by 29·0% (28·7 to 29·3) from 1990 to 2015, the rates of mortality decline in this period substantially varied across the prefectures, ranging from -32·4% (-34·8 to -30·0) to -22·0% (-20·4 to -20·1). During the same time period, the rate of age-standardised DALYs was reduced overall by 19·8% (17·9 to 22·0). The reduction in rates of age-standardised YLDs was very small by 3·5% (2·6 to 4·3). The pace of reduction in mortality and DALYs in many leading causes has largely levelled off since 2005. Known risk factors accounted for 34·5% (32·4 to 36·9) of DALYs; the two leading behavioural risk factors were unhealthy diets and tobacco smoking in 2015. The common health system inputs were not associated with age-standardised death and DALY rates in 2015.InterpretationJapan has been successful overall in reducing mortality and disability from most major diseases. However, progress has slowed down and health variations between prefectures is growing. In view of the limited association between the prefecture-level health system inputs and health outcomes, the potential sources of regional variations, including subnational health system performance, urgently need assessment.FundingBill &amp; Melinda Gates Foundation, Japan Ministry of Education, Science, Sports and Culture, Japan Ministry of Health, Labour and Welfare, AXA CR Fixed Income Fund and AXA Research Fund

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Para-Hydroxycinnamic Acid Mitigates Senescence and Inflammaging in Human Skin Models

Para-hydroxycinnamic acid (pHCA) is one of the most abundant naturally occurring hydroxycinnamic acids, a class of chemistries known for their antioxidant properties. In this study, we evaluated the impact of pHCA on different parameters of skin aging in in vitro skin models after H2O2 and UV exposure. These parameters include keratinocyte senescence and differentiation, inflammation, and energy metabolism, as well as the underlying molecular mechanisms. Here we demonstrate that pHCA prevents oxidative stress-induced premature senescence of human primary keratinocytes in both 2D and 3D skin models, while improving clonogenicity in 2D. As aging is linked to inflammation, referred to as inflammaging, we analyzed the release of IL-6, IL-8, and PGE2, known to be associated with senescence. All of them were downregulated by pHCA in both normal and oxidative stress conditions. Mechanistically, DNA damage induced by oxidative stress is prevented by pHCA, while pHCA also exerts a positive effect on the mitochondrial and glycolytic functions under stress. Altogether, these results highlight the protective effects of pHCA against inflammaging, and importantly, help to elucidate its potential mechanisms of action

Broad Surveys of DNA Viral Diversity Obtained through Viral Metagenomics of Mosquitoes

Viruses are the most abundant and diverse genetic entities on Earth; however, broad surveys of viral diversity are hindered by the lack of a universal assay for viruses and the inability to sample a sufficient number of individual hosts. This study utilized vector-enabled metagenomics (VEM) to provide a snapshot of the diversity of DNA viruses present in three mosquito samples from San Diego, California. The majority of the sequences were novel, suggesting that the viral community in mosquitoes, as well as the animal and plant hosts they feed on, is highly diverse and largely uncharacterized. Each mosquito sample contained a distinct viral community. The mosquito viromes contained sequences related to a broad range of animal, plant, insect and bacterial viruses. Animal viruses identified included anelloviruses, circoviruses, herpesviruses, poxviruses, and papillomaviruses, which mosquitoes may have obtained from vertebrate hosts during blood feeding. Notably, sequences related to human papillomaviruses were identified in one of the mosquito samples. Sequences similar to plant viruses were identified in all mosquito viromes, which were potentially acquired through feeding on plant nectar. Numerous bacteriophages and insect viruses were also detected, including a novel densovirus likely infecting Culex erythrothorax. Through sampling insect vectors, VEM enables broad survey of viral diversity and has significantly increased our knowledge of the DNA viruses present in mosquitoes

Aldosterone does not require angiotensin II to activate NCC through a WNK4–SPAK–dependent pathway

We and others have recently shown that angiotensin II can activate the sodium chloride cotransporter (NCC) through a WNK4–SPAK-dependent pathway. Because WNK4 was previously shown to be a negative regulator of NCC, it has been postulated that angiotensin II converts WNK4 to a positive regulator. Here, we ask whether aldosterone requires angiotensin II to activate NCC and if their effects are additive. To do so, we infused vehicle or aldosterone in adrenalectomized rats that also received the angiotensin receptor blocker losartan. In the presence of losartan, aldosterone was still capable of increasing total and phosphorylated NCC twofold to threefold. The kinases WNK4 and SPAK also increased with aldosterone and losartan. A dose-dependent relationship between aldosterone and NCC, SPAK, and WNK4 was identified, suggesting that these are aldosterone-sensitive proteins. As more functional evidence of increased NCC activity, we showed that rats receiving aldosterone and losartan had a significantly greater natriuretic response to hydrochlorothiazide than rats receiving losartan only. To study whether angiotensin II could have an additive effect, rats receiving aldosterone with losartan were compared with rats receiving aldosterone only. Rats receiving aldosterone only retained more sodium and had twofold to fourfold increase in phosphorylated NCC. Together, our results demonstrate that aldosterone does not require angiotensin II to activate NCC and that WNK4 appears to act as a positive regulator in this pathway. The additive effect of angiotensin II may favor electroneutral sodium reabsorption during hypovolemia and may contribute to hypertension in diseases with an activated renin–angiotensin–aldosterone system