Proteomic Analysis of Mouse Brain Subjected to Spaceflight.

There is evidence that spaceflight poses acute and late risks to the central nervous system. To explore possible mechanisms, the proteomic changes following spaceflight in mouse brain were characterized. Space Shuttle Atlantis (STS-135) was launched from the Kennedy Space Center (KSC) on a 13-day mission. Within 3⁻5 h after landing, brain tissue was collected to evaluate protein expression profiles using quantitative proteomic analysis. Our results showed that there were 26 proteins that were significantly altered after spaceflight in the gray and/or white matter. While there was no overlap between the white and gray matter in terms of individual proteins, there was overlap in terms of function, synaptic plasticity, vesical activity, protein/organelle transport, and metabolism. Our data demonstrate that exposure to the spaceflight environment induces significant changes in protein expression related to neuronal structure and metabolic function. This might lead to a significant impact on brain structural and functional integrity that could affect the outcome of space missions.

Synthesis of and structural studies on repeating sequences of abductin.

Little data exist on the structure and function of compressible elastomeric proteins such as abductin. An understanding of the underlying structural features of these proteins may lead to the development of a new class of highly tailored "compressible" hydrogels. To that effect, in this work, the structure of abductin was investigated by means of studies on several synthetic peptides corresponding to the most frequent sequences of abductin. In particular, the 10 amino acid abductin peptide sequence FGGMGGGNAG, tandem repeated in the protein, and two related 25 and 40 amino acid polypeptides were synthesized. These peptides were studied with regard to secondary structure, self-assembly, and polymer morphology. The results obtained with these peptides allow us to propose a preliminary structure-elasticity relationship for abductin not dissimilar from that currently accepted for elastin.A possible mechanism of elasticity relating abductin to elastin.

Abnormalities of serum antielastin antibodies in connective tissue diseases.

BACKGROUND: Antibodies (Abs) to alpha-elastin (elastin breakdown product) and tropoelastin (elastin precursor) are found in the serum of all human subjects and correlate with their respective serum peptide levels; however, peptide levels vary with age and some disease states. This study was undertaken to determine if serum elastin Abs, peptides, and elastin metabolism were altered in autoimmune diseases by detecting a changing ratio of serum anti-alpha:tropoelastin Ab levels. METHODS: Serum from patients with a variety of connective tissue diseases, including 28 with systemic lupus erythematosus (SLE), 24 with scleroderma, 18 with rheumatoid arthritis (RA), 10 with polymyositis, and 39 with vasculitis, was compared with serum from 19 age-matched healthy subjects for levels of antitropoelastin and anti-alpha-elastin Abs. RESULTS: We found an increase in IgG anti-alpha-elastin and a decrease in antitropoelastin Abs in the sera of patients with scleroderma (p < .02 and .00005) and SLE (p < .006 and .011). There was also a marked increase in anti-alpha-elastin Abs in patients with polyarteritis nodosa (p < .0005) and decreases in antitropoelastin Abs in patients with RA (p < .05), polymyositis (p < .01), and a variety of other vasculidities (p < .0003). CONCLUSIONS: Abnormal variations in elastin metabolism may be detected in several connective tissue diseases by measuring ratios of alpha- and tropoelastin IgG Abs as markers of elastin degradation and synthesis.