Developmental changes in soluble proteins during the early development of Dictyostelium discoideum

Changes in the pattern of soluble proteins that accumulatedat the growth phase, interphase and late-aggregation phase ofthe cellular slime mold Dictyostelium discoideum were studiedby two-dimensional polyacrylamide gel electrophoresis. Amongthe 300 proteins detected during the early development, themost soluble do not change during the growth and aggregationphases, but about 90 proteins show changes in their relativeintensities on staining. During the transition from growth tothe interphase, the predominant changes were the disappearanceof 16 spots, the decrease in 30 spots, the appearance of 13new spots, and the increase in 14 spots. In contrast, from theinterphase to the late-aggregation phase, there were remarkableprogressive increases in 13 spots, an overall increase in 6spots, a decrease in 16 spots, the appearance of 8 new spotsand the disappearance of 4 spots. (Received July 13, 1979; )     

Photosynthetic regeneration of ATP using a strain of thermophilic blue-green algae

Photosynthetic ATP accumulation was shown in the presence of exogenous ADP plus orthophosphate on illumination to the intact cells of a strain of thermophilic blue-green algae isolated from Matsue hot springs, Mastigocladus sp. Kinetic studies of various effectors on the ATP accumulation proved that the ATP synthesis depends mainly on the cyclic photophosphorylation system around photosystem I (PS-I) in the algal cells. The temperature and pH optima for the accumulation were found at 45 degrees C and pH 7.5. Maximum yield was obtained with light intensity higher than 15 mW/cm(2). Borate ion exerted pronounced enhancement on the ATP synthesis. With a continuous reactor at a flow rate of 1 ml/hr at 45 degrees C and pH 7.5, efficient photoconversion of ADP (2mM, at substrate reservoir) to ATP (1mM, at product outlet) has been maintained for a period of 2.5 days, though the efficiency has decreased in a further 2-day period to the level of 0.5mM ATP/9.5 h of residence time.     

Limulus anti-LPS factor: An anticoagulant which inhibits the endotoxin-mediated activation of Limulus coagulation system

Exposure of $\text{Limulus}$ amebocytes to bacterial endotoxins (lipopolysaccharides, LPS) results in the activation of the coagulation system, which consists of several protein components. During the separation of these components, a potent anticoagulant, named tentatively anti-LPS factor, which inhibits the endotoxin-mediated coagulation reaction, was found in both amebocytes from the hemolymphs of $\text{Tachypleus}\text{tridentatus}$ and $\text{Limulus}\text{polyphemus}$. The principle purified partially from $\text{Tachypleus}$ amebocyte lysate had a molecular weight less than 10,000, as judged with the ordinary gelfiltration experiment. It inhibited specifically the activation of factor B, which has recently been characterized to be a coagulation factor highly sensitive to LPS, but it did not inhibit the activities of the active factor B and the active clotting enzyme separated from the lysate. The inhibitory activity of anti-LPS factor disappeared almost completely by the treatments with pronase-P and subtilisin, suggesting its polypeptide-like substance, but it resisted to a boiling treatment. A possible site of the anticoagulant action on the $\text{Limulus}$ coagulation system was discussed.     

Dynamic sweating response of man to infrared irradiation in various spectral regions

In an attempt to detect differences in the thermal effect of infrared irradiation of different wavelengths, transient sweating response to infrared irradiation in various spectral regions was examined. In Series 1, the ventral or dorsal surface of the nude subject was irradiated repetitively for a period of 4 min (2 min on, 2 min off) by each of three kinds of infrared heaters with main emissivity in near-infrared (NIR; 0.7–2.8 m), intermediate-infrared (MIR; 1.5–5.8 m), and far-infrared (FIR; 2.8–25 m) regions. The sweating response on a non-irradiated area tended to be the greatest with MIR, while the magnitude of the sweating response on the irradiated area showed no consistent differences among various wavelengths. The results infer that MIR stimulated cutaneous thomoreceptors most effectively, while its direct effect on local sweat gland activity was minimal. In Series 2, the effects of 9–12 min irradiations in more restricted ranges of wavelength were compared by the combination of the three kinds of heaters with filters (translucent to wavelength ranges of 1.3–2.7, 2.7–3.5, 3.6–8.0 m, respectively). The sweating response on a remote area was predominantly greater with the range of 2.7–3.5 m than with the other wavelength ranges, while the local effect on sweating was minimal with this range. The results of Series 2 reinforce those of Series 1, indicating that the degree of stimulation of cutaneous thermoreceptors and of direct thermal effect on sweat gland activity differ with spectral regions incident on the skin, thus affecting local and remote effects on the sweating response.     

Earthworm (Pheretima communissima and Pheretima hilgendorfi) hemoglobins: giant assemblies and subunits

The molecular architecture of hemoglobins and their subunits of the earthworms Pheretima communissima and Pheretima hilgendorfi was investigated. In both species, their s0.20,w of 60.8 S and D020,w of 1.80 . 10(-7) cm2 . s-1 corresponded to a molecular weight of 3.07 . 10(6). From electron microscopic observations, the overall structure of the hemoglobins was shown to be two superimposed hexagonal discs, each composed of six-membered constituents. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of both hemoglobins revealed the presence of five species of subunits with molecular weights of 13,000-14,000 (subunit 1), 27,000-28,000 (subunit 2), 30,000-31,000 (subunit 3), 33,000-34,000 (subunit 4) and approx. 52,000 (subunit 5), respectively, and the molar ratio of these subunits 1:2, 3, 4:5 was 2:3:3. If we consider this set of the subunits 1 to 5 as one unit, the molecular weight of this unit should be 2.7-2.8 . 10(5). This one unit, therefore, should be considered to represent one-twelfth the whole molecule with molecular weight of 3.07 . 10(6).     

Microorganism Capable of Decomposing N-Acetylglucosaminyl Ribitol Teichoic Acid of Staphylococcus aureus

Enzyme(s) capable of decomposing N-acetylglucosaminyl ribitol teichoic acid prepared from the cell wall of Staphylococcus aureus FDA 209 P was obtained from the culture supernatant of a gram-negative, rod-shaped, spore-forming soil bacterium. Properties of the bacterium were very similar to those of Bacillus circulans.     

Apoptosis inhibitor of macrophage (AIM) expression in alveolar macrophages in COPD

Background

Marked accumulation of alveolar macrophages (AM) conferred by apoptosis resistance has been implicated in pathogenesis of chronic obstructive pulmonary disease (COPD). Apoptosis inhibitor of macrophage (AIM), has been shown to be produced by mature tissue macrophages and AIM demonstrates anti-apoptotic property against multiple apoptosis-inducing stimuli. Accordingly, we attempt to determine if AIM is expressed in AM and whether AIM is involved in the regulation of apoptosis in the setting of cigarette smoke extract (CSE) exposure.

Methods

Immunohistochemical evaluations of AIM were performed. Immunostaining was assessed by counting total and positively staining AM numbers in each case (n = 5 in control, n = 5 in non-COPD smoker, n = 5 in COPD). AM were isolated from bronchoalveolar lavage fluid (BALF). The changes of AIM expression levels in response to CSE exposure in AM were evaluated. Knock-down of anti-apoptotic Bcl-xL was mediated by siRNA transfection. U937 monocyte-macrophage cell line was used to explore the anti-apoptotic properties of AIM.

Results

The numbers of AM and AIM-positive AM were significantly increased in COPD lungs. AIM expression was demonstrated at both mRNA and protein levels in isolated AM, which was enhanced in response to CSE exposure. AIM significantly increased Bcl-xL expression levels in AM and Bcl-xL was involved in a part of anti-apoptotic mechanisms of AIM in U937 cells in the setting of CSE exposure.

Conclusions

These results suggest that AIM expression in association with cigarette smoking may be involved in accumulation of AM in COPD.     

Cyclin D1 overexpression perturbs DNA replication and induces replication-associated DNA double-strand breaks in acquired radioresistant cells

Fractionated radiotherapy (RT) is widely used in cancer treatment, because it preserves normal tissues. However, repopulation of radioresistant tumors during fractionated RT limits the efficacy of RT. We recently demonstrated that a moderate level of long-term fractionated radiation confers acquired radioresistance to tumor cells, which is caused by DNA-PK/AKT/GSK3β-mediated cyclin D1 overexpression. The resulting cyclin D1 overexpression leads to forced progression of the cell cycle to S-phase, concomitant with induction of DNA double-strand breaks (DSBs). In this study, we investigated the molecular mechanisms underlying cyclin D1 overexpression-induced DSBs during DNA replication in acquired radioresistant cells. DNA fiber data demonstrated that replication forks progressed slowly in acquired radioresistant cells compared with corresponding parental cells in HepG2 and HeLa cell lines. Slowly progressing replication forks were also observed in HepG2 and HeLa cells that overexpressed a nondegradable cyclin D1 mutant. We also found that knockdown of Mus81endonuclease, which is responsible for resolving aberrant replication forks, suppressed DSB formation in acquired radioresistant cells. Consequently, Mus81 created DSBs to remove aberrant replication forks in response to replication perturbation triggered by cyclin D1 overexpression. After treating cells with a specific inhibitor for DNA-PK or ATM, apoptosis rates increased in acquired radioresistant cells but not in parental cells by inhibiting the DNA damage response to cyclin D1-mediated DSBs. This suggested that these inhibitors might eradicate acquired radioresistant cells and improve fractionated RT outcomes.