Search NASA⌕ Search

SEARCH · Search NASA

Results for “sphingolipids”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

3 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Differences in glycogen, lipids, and enzymes in livers from rats flown on Cosmos 2044

Livers from rats flown aboard Cosmos 2044 were analyzed for protein, carbohydrate (glycogen), and lipids as well as the activities of a number of key enzymes involved in metabolism of these compounds and xenobiotics. The major differences between the flight group and the synchronous control were elevations in microsomal protein, liver glycogen content, tyrosine aminotransferase, and tryptophan oxygenase and reductions in sphingolipids and the rate-limiting enzyme of heme biosynthesis delta-aminolevulinic acid synthase. These results provide further evidence that spaceflight has pronounced and diverse effects on liver function; however, some of the results with samples from Cosmos 2044 differed notably from those from previous spaceflights. This may be due to conditions of spaceflight and/or the postflight recovery period for Cosmos 2044.

Merrill, Alfred H., Jr.↗
NASA NTRS1992

A partial phylogenetic analysis of the "flavobacter-bacteroides" phylum: basis for taxonomic restructuring

On the basis of small subunit rRNA sequence analyses five major subgroups within the flavobacteria-bacteroides phylum have been defined. These are tentatively designated the cytophaga subgroup (comprising largely Cytophaga species), the flavobacter subgroup (comprising the true flavobacteria and the polyphyletic genus Weeksella), the bacteroides subgroup (comprising the bacteroides and certain cytophaga-like bacteria), the sphingobacter subgroup (which contains the known sphingolipid-producing members of the phylum), and the saprospira subgroup (comprising particular species of Flexibacter, Flavobacterium, Haliscomenobacter, and, of course, the genus Saprospira). These groupings are given not only by evolutionary distance analysis, but can be defined and distinguished on the basis of a simple small subunit rRNA signatures.

NASA Discipline Exobiology↗
NASA NTRS2017

Spaceflight Activates Autophagy Programs and the Proteasome in Mouse Liver

Increased oxidative stress is an unavoidable consequence of exposure to the space environment. Our previous studies showed that mice exposed to space for 13.5 days had decreased glutathione levels, suggesting impairments in oxidative defense. Here we performed unbiased, unsupervised and integrated multi-'omic analysis of metabolomic and transcriptomic datasets from mice flown aboard the Space Shuttle Atlantis. Enrichment analyses of metabolite and gene sets showed significant changes in osmolyte concentrations and pathways related to glycerophospholipid and sphingolipid metabolism, likely consequences of relative dehydration of the spaceflight mice. However, we also found increased enrichment of aminoacyl-tRNA biosynthesis and purine metabolic pathways, concomitant with enrichment of genes associated with autophagy and the ubiquitin-proteasome. When taken together with a down-regulation in NRF2-mediated signaling, our analyses suggest that decreased hepatic oxidative defense may lead to aberrant tRNA post-translational processing, induction of degradation programs and senescence-associated mitochondrial dysfunction in response to the spaceflight environment..

Autophagy↗