Changes in ultraweak photon emission and heart rate variability of epinephrine-injected rats

Ultraweak photons which are spontaneously emitted from a living body may be applicable as a non-invasive tool to characterize the physiological state of the living body. We investigated changes in the intensity of ultraweak photon emission, body temperature and the cardiovascular autonomic activity induced by epinephrine injection to rats. A high dose of epinephrine can make changes to the cardiovascular autonomic activity or body temperature. Photon emission of the dorsal part, rectal temperature and heart rate variability (HRV) were measured from eight Sprague-Dawley rats. The intensities of photon emissions for saline injections, which were used as a control, decreased from 13042+/-71 counts/min at the start of measurements to 8709+/-915 counts/min at 1 h after the injections. In the case with epinephrine injections, the intensity of photon emission reduced slowly from 13361+/-354 counts/min to 11040+/-433 counts/min. Rectal temperature increased in both saline- and epinephrine-injected rats, but one hour after the injections the temperature in the epinephrine case was slightly higher than that in the saline case. The standard deviation of the QRS wave complex interval (RR interval) increased from 1 to 4 (p<0.05) and the spectral ratio of the low frequency component to the high frequency component in the HRV data LF (0.19 approximately 0.74 Hz) / HF (0.78 approximately 2.50 Hz) decreased from 0.81 to 0.26 (p<0.05) in the case of epinephrine injection while no change was found in the case of saline injection. Thus, ultraweak photon emission was closely related to the cardiovascular autonomic activity.     

Genomic segments cloning and analysis of Cotesia plutellae polydnavirus using plasmid capture system

Cotesia plutellae polydnaviruses (CpBV) has a segmented genome consisting of multiple circular double stranded DNAs. Recently, we have developed an easy, simple, and convenient system based on Tn7 transposition in order to clone genomic segments of CpBV in Escherichia coli cell and designated plasmid capture system (PCS). The PCS donor-S transferred a pUC19 origin of replication and an ampicillin resistance marker into CpBV genomic DNA by in vitro transposition. Through PCS system, we were able to clone 53 genomic clones ranging from 0.1 to 25.5 kb and further they were classified into 29 segments by their sizes and restriction endonuclease patterns. Among them, a complete nucleotide sequence of CpBV-S28 segment was determined and 10 putative genes were predicted from this segment. Interestingly, 9 of 10 putative ORFs had high level of similarities with catalytic domain of protein tyrosine phosphatase. Also, ORF2807 showed similarity with EP1-like proteins of C. congregata polydnavirus.     

Annexin A2-S100A10 heterotetramer, a novel substrate of thioredoxin

The binding of plasminogen activators and plasminogen to the cell surface results in the rapid generation of the serine protease plasmin. Plasmin is further degraded by an autoproteolytic reaction, resulting in the release of an angiostatin, A61 (Lys78-Lys468). Previously, we demonstrated that the annexin A2-S100A10 heterotetramer (AIIt) stimulates the release of A61 from plasmin by promoting the autoproteolytic cleavage of the Lys468-Gly469 bond and reduction of the plasmin Cys462-Cys541 disulfide (Kwon, M., Caplan, J. F., Filipenko, N. R., Choi, K. S., Fitzpatrick, S. L., Zhang, L., and Waisman, D. M. (2002) J. Biol. Chem. 277, 10903-10911). Mechanistically, it was unclear if AIIt promoted a conformational change in plasmin, resulting in contortion of the plasmin disulfide, or directly reduced the plasmin disulfide. In the present study, we show that AIIt thiols are oxidized during the reduction of plasmin disulfides, establishing that AIIt directly participates in the reduction reaction. Incubation of HT1080 cells with plasminogen resulted in the rapid loss of thiol-specific labeling of AIIt by 3-(N-maleimidopropionyl)biocytin. The plasminogen-dependent oxidation of AIIt could be attenuated by thioredoxin. Thioredoxin reductase catalyzed the transfer of electrons from NADPH to the oxidized thioredoxin, thus completing the flow of electrons from NADPH to AIIt. Therefore, we identify AIIt as a substrate of the thioredoxin system and propose a new model for the role of AIIt in the redox-dependent processing of plasminogen and generation of an angiostatin at the cell surface.     

Investigation of cell cycle arrest effects of actinomycin D at G1 phase using proteomic methods in B104-1-1 cells

Actinomycin D was previously reported as an inhibitor of Shc/Grb2 interaction in B104-1-1 cells. Actinomycin D arrested the cell cycle at the G1 phase at 1nM, which is about 10 times lower than the inhibition of Shc/Grb2 interactions in B104-1-1 cells. To evaluate other mechanisms of actinomycin D affected suppression of tumors and cell growth, except inhibition of Shc/Grb2 interactions, we examined the proteomic expression profile by proteomic technology. We found up-regulation of MEKK3 and down-regulation of Hsp70 expression from proteomic analysis, which is a very interesting observation because MEKK3 is strongly related with G1 arrest of cell cycle and Hsp70 is also involved in cell cycle regulation. These results indicate that the anti-tumor effects of actinomycin D is due to synergic effects of various proteins regulated by the compound including inhibition of the Shc/Grb2 interaction and other signaling pathways in the cytoplasm. Here we provide a mechanism-based explanation for growth inhibition by actinomycin D using proteomic technology. Thus, this approach may be a potentially useful method to reveal new mechanisms of active compounds or drugs with unknown cellular function.