Oxytocin is widely believed to be present and structurally identical in all placental mammals. Here, we report that multiple species of New World monkeys possess a novel form of oxytocin, [P8] oxytocin. This mutation arises from a substitution of a leucine to a proline in amino acid position 8. Further analysis of this mutation in Saimiri sciureus (squirrel monkey) indicates that [P8] oxytocin is transcribed and translated properly. This mutation is specific to oxytocin, as the peptide sequence for arginine vasopressin, a structurally related nonapeptide, is unaltered. These findings dispel the notion that all placental mammals possess a ‘universal’ oxytocin sequence, and highlight the need for research on the functional significance of this novel nonapeptide in New World monkeys.
The pruritic skin disease scabies is caused by the burrowing of the itch mite Sarcoptes scabiei (De Geer). It is difficult to diagnose this disease because its symptoms often resemble those of other skin diseases. No reliable blood or molecular diagnostic test is available. The aim of this project was to begin to characterize the scabies proteome to identify scabies mite proteins, including those that may be useful in the development of a diagnostic test or vaccine. Various scabies mite extracts were separated by two-dimensional electrophoresis, and 844 Coomassie Blue-stained protein spots were excised, subjected to trypsin digestion, and analyzed by Matrix Assisted Laser Desorption/Ionization Time-Of-Flight/Time-Of-Flight (MALDI-TOF/TOF) mass spectrometry (MS). Tryptic fragment sequences determined by MS were searched against the recently completed S. scabiei annotated genome, leading to the identification of >150 proteins. Only 10 proteins hit to previously identified scabies proteins including actin, tropomyosin, and several ABC transporters. Thirteen proteins had homology to dust mite allergens (members of groups 8, 10, 13, 17, 20, 25, and 28). Most other sequences showed some homology to proteins in other mites and ticks including homologs of calmodulin, calreticulin, lipocalin, and glutathione-Stransferase. These data will now allow the identification of the proteins to which scabies patients produce antibodies, including those that may be good candidates for inclusion in a diagnostic test and vaccine.
Pro-vasopressin and pro-oxytocin are prohormones processed in the neurointermediate lobe pituitary to form the biologically active peptide hormones, arginine vasopressin (AVP) and oxytocin. Neurointermediate lobe pituitaries from normal (+/+), heterozygous (+/−), PC2-Null (−/−), PC1/3-Null and oxytocin-Null mice were analyzed by SELDI-TOF mass spectroscopy for the peptide hormone products, AVP, oxytocin and neurophysin I and II. Molecular ion species with masses characteristic of oxytocin, AVP, neurophysin I and II, i.e. 1009·41, 1084·5, 9677 and 9679 daltons respectively, were identified in all but the oxytocin-Null mice by comparison with synthetic standards or by C-terminal sequence analysis. Other ion species were found specifically in PC2-Null, heterozygote or normal mice. The results indicate that, in mice, both PC1/3 or PC2 enzyme activity are capable, but not required to correctly process pro-vasopressin or pro-oxytocin to their constituent active peptide hormones.
Background: Leukemic cell differentiation is blocked in vivo but can be reversed in vitro. Results: A new signaling sequence involving specific kinases and phospholipases along the path to cell differentiation. Conclusion: PLD shortens the differentiation time of cells becoming mature neutrophils. Significance: Achieving a shortened time is highly beneficial for the induction therapy of acute myelocytic leukemia patients.
Interleukin-2 (IL-2) is a multi-faceted cytokine, known for promoting proliferation, survival, and cell death depending on the cell type and state. For example, IL-2 facilitates cell death only in activated T cells when antigen and IL-2 are abundant. The availability of IL-2 clearly impacts this process. Our laboratory recently demonstrated that IL-2 is retained in blood vessels by heparan sulfate, and that biologically active IL-2 is released from vessel tissue by heparanase. We now demonstrate that heparanase digestion also releases a dimeric form of IL-2 that is highly cytotoxic to cells expressing the IL-2 receptor. These cells include “traditional” IL-2 receptor-bearing cells such as lymphocytes, as well as those less well known for IL-2 receptor expression, such as epithelial and smooth muscle cells. The morphologic changes and rapid cell death induced by dimeric IL-2 imply that cell death is mediated by disruption of membrane permeability and subsequent necrosis. These findings suggest that IL-2 has a direct and unexpectedly broad influence on cellular homeostatic mechanisms in both immune and non-immune systems.
The broad-spectrum apoptosis (caspase) inhibitor, Q-VD-OPh, has been shown to have no side effects and is effective at a much lower concentration than other FMK-type caspase inhibitors. However, an appropriate negative control to use with this inhibitor has not been available. In this study, we developed and analyzed a new compound, based on the Q-VD-OPh backbone, which acts as a cognate negative control. To create the negative control, we substituted a glutamate residue for the aspartate residue to create Q-VE-OPh, thereby retaining the identical charge and molecular properties with only the addition of an extra -CH2 group. The purity and quality were assessed by ion trap mass spectrometry and verified by nuclear magnetic resonance. We determined the effectiveness of Q-VE-OPh, in comparison to Q-VD-OPh, to prevent DNA fragmentation in human Jurkat T leukemia cells that were induced to undergo apoptosis. DNA fragmentation was analyzed by agarose gel electrophoresis for the presence of DNA laddering, the hallmark indicator of apoptosis. Our results indicate that apoptosis was potently inhibited by Q-VD-OPh. In stark contrast, Q-VE-OPh did not inhibit apoptosis at a similar dose but required at least 20 times greater concentration than Q-VD-OPh to have any inhibitory effect. Western blot analysis showed that Q-VE-OPh was similarly less effective at inhibiting the activation of the extrinsic (caspase 8) and intrinsic (caspase 9) initiator caspases. Cell proliferation and viability studies further demonstrate that Q-VE-OPh is non-toxic, even at high concentration. Our data indicate that the specificity, effectiveness, and absence of toxicity of Q-VE-OPh provides the appropriate and superior negative control for in vitro and in vivo studies when analyzing the effects of o-phenoxy caspase inhibitors.
Organophosphates (OP) cause CNS hyperstimulation resulting in seizures, convulsions and brain damage. Sarin is a toxic nerve agent used in Syria, the Gulf War and in terrorist attacks in Japan. Exposure to sarin is associated with presence of dead neurons, activation of astrocytes, microglia and NI. Since, cell death and NI are found in sarin exposed animals, we evaluated the efficacy of Q‐VD‐OPh, a pan spectrum caspase inhibitor that prevents cell death and has anti‐inflammatory properties. Currently, treatment for sarin exposures is effective only if administered within 30‐40 minutes of exposure. In this study, adult female C57BL/6 mice were subjected to an injection of 1.5 mg/kg CBDP before a 0.04mg/kg injection of sarin followed by 20 mg/kg injection of Q‐VD‐OPh 30 minutes later. Mice were sacrificed at two and fourteen day time points followed by BioPlex (Bio Rad) cytokine analysis of amygdala, hippocampus and piriform cortex. At two days, there was a significant increase (p<0.05) in IL‐2, IL‐10, IL‐1b, MIP‐1b and MCP‐1in sarin exposed mice, and a significant decrease in the same when injected with Q‐VD‐ OPh. Q‐VE‐OPh did not appear to have an effect. The data strongly suggests that Q‐VD‐OPh provides anti‐inflammatory properties in mice exposed to sarin. This project was supported by a grant from the NIH R21NS072103‐03. Dr. Cool and Dr. Brown have an equity interest in Apoptrol, LLC (Vice President and President, respectively) which supplied the Q‐VD‐OPh and Q‐VE‐OPh for the study. Grant Funding Source: NIH R21NS072103‐03
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