Real-time detection and continuous monitoring of ER stress in vitro and in vivo by ES-TRAP: evidence for systemic, transient ER stress during endotoxemia

Activity of secreted alkaline phosphatase (SEAP) produced by transfected cells is rapidly down-regulated by endoplasmic reticulum (ER) stress independent of transcriptional regulation. This phenomenon was observed in a wide range of cell types triggered by various ER stress inducers. The magnitude of the decrease in SEAP was proportional to the extent of ER stress and inversely correlated with the induction of endogenous ER stress markers grp78 and grp94. In contrast to SEAP, activity of secreted luciferase was less susceptible to ER stress. The decrease in SEAP activity by ER stress was caused by abnormal post-translational modification, accelerated degradation and reduced secretion of SEAP protein. In transgenic mice constitutively producing SEAP, systemic induction of ER stress led to reduction in serum SEAP. In these mice, administration with lipopolysaccharide caused rapid, transient decrease in serum SEAP activity, and it was correlated with up-regulation of grp78 in several organs including the spleen, lung, kidney, liver and heart. These results elucidated for the first time a possible involvement of transient, systemic ER stress in endotoxemia and provided evidence for usefulness of ER stress responsive alkaline phosphatase for real-time monitoring of ER stress in vitro and in vivo

Temporal changes in coda Q-1 and b value due to the static stress change associated with the 1995 Hyogo-ken Nanbu earthquake

The seismicity in the Tamba region, northeast of the Hyogo-ken Nanbu earthquake in Japan (January 17, 1995; M(JMA) 7.2), increased significantly following this earthquake. This increase suggests that the static stress change due to a large earthquake causes a change in the crustal condition of dynamics. In order to reveal the changes quantitatively, we investigate the temporal variation in coda Q-1 and b value in the Tamba region. We analyze the waveform data of many shallow microearthquakes (M 1.5-3.0) in the region recorded in a period from 1987 to 1996. Coda Q-1 is estimated in 10 frequency bands in a range of 1.5-24 Hz based on the single isotropic scattering model. At frequencies between 1.5 and 4.0 Hz the temporal variation in coda Q-1 shows significant correlation with the occurrence of the Hyogo-ken Nanbu earthquake; coda Q-1 increases after the event. A variation in b value whose sign is opposite to that of coda Q-1 is recognized. The fracture dimensions of microearthquakes that contribute to the variation in b value are estimated to be 400 m. This scale length is consistent with the characteristic scale length of scatter, 300-600 m, which contributes effectively to a temporal variation in coda Q-1. The crustal activity in the Tamba region is possibly controlled by the heterogeneity with dominant scale of 102 m. The stress sensitivity of the coda Q-1 change is estimated to be 10 (MPa)-1. This value is an order of magnitude larger than the stress sensitivity of seismic velocity reported before

Direct, Continuous Monitoring of Air Pollution by Transgenic Sensor Mice Responsive to Halogenated and Polycyclic Aromatic Hydrocarbons

BACKGROUND: The aryl hydrocarbon receptor (AhR, also called the dioxin receptor) plays crucial roles in toxicologic responses of animals to environmental pollutants, especially to halogenated and polycyclic aromatic hydrocarbons. To achieve direct, continuous risk assessment of air pollution using biological systems, we generated transgenic sensor mice that produce secreted alkaline phosphatase (SEAP) under the control of AhR. METHODS: To characterize responses of the mice to AhR agonists, sensor mice were orally administered 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3-methylcholanthrene (3MC), benzo[a]pyrene (B[a]P), or β-naphthoflavone (BNF), and serum levels of SEAP were evaluated. To monitor air pollution caused by cigarette smoke, we placed the mice each day in an experimental smoking room, and evaluated activity of serum SEAP for up to 4 days. Activation of AhR in individual organs was also examined by reverse transcription–polymerase chain reaction (RT-PCR) analysis of SEAP. RESULTS: In response to oral exposure to TCDD, sensor mice exhibited dramatic and sustained activation of AhR. The mice also responded sensitively to 3MC, B[a]P, and BNF. Activation of AhR was dose dependent, and the liver was identified as the main responding organ. After exposure to the smoking environment, sensor mice consistently exhibited transient, reversible activation of AhR. RT-PCR analysis of SEAP revealed that activation of AhR occurred predominantly in the lung. CONCLUSION: We are the first laboratory to demonstrate successfully direct, comprehensive monitoring of air pollution using genetically engineered mammals. The established system would be useful for real risk assessment of halogenated and polycyclic aromatic hydrocarbons in the air, especially in smoking environments. KEY WORDS: aromatic hydrocarbon, aryl hydrocarbon receptor (AhR), cigarette smoke, dioxinresponsive element (DRE), secreted alkaline phosphatase (SEAP), transgenic mouse. Enviro

Estimation of annual layer thickness from stratigraphical analysis of Dome Fuji deep ice core

Dating of ice cores is of important but is difficult for an ice core where there is low snow accumulation, and also for the deep part because seasonal chemical and isotopic signals are not easily preserved due to vapor migration after snow deposition and molecular diffusion in the deep part of ice sheet. In this paper, an attempt to reveal annual layer thickness is conducted on the basis of precise number density measurement of air bubbles and air hydrates. The annual layer thickness from air bubbles and hydrates agrees well with a calculated value within 10-15% at all depths of the 2500 m deep core. The obtained thickness in the interglacial period according to Eemian period in the Greenland ice core was half of the calculated value

Transcriptional suppression of nephrin in podocytes by macrophages: Roles of inflammatory cytokines and involvement of the PI3K/Akt pathway

AbstractExpression of nephrin, a crucial component of the glomerular slit diaphragm, is downregulated in patients with proteinuric glomerular diseases. Using conditionally immortalized reporter podocytes, we found that bystander macrophages as well as macrophage-derived cytokines IL-1β and TNF-α markedly suppressed activity of the nephrin gene promoter in podocytes. The cytokine-initiated repression was reversible, observed on both basal and inducible expression, independent of Wilms’ tumor suppressor WT1, and caused in part via activation of the phosphatidylinositol-3-kinase/Akt pathway. These results indicated a novel mechanism by which activated macrophages participate in the induction of proteinuria in glomerular diseases

Novel potential of tunicamycin as an activator of the aryl hydrocarbon receptor – dioxin responsive element signaling pathway

AbstractTunicamycin is a well-known inhibitor of protein glycosylation and used as an inducer of endoplasmic reticulum (ER) stress. We found that tunicamycin induced expression of cytochrome P450 1A1 in a dose-dependent manner. Like dioxin, the transcriptional induction was associated with dose-dependent activation of the dioxin responsive element (DRE). This effect was independent of inhibition of protein glycosylation or induction of ER stress. Pharmacological and genetic inhibition of the aryl hydrocarbon receptor (AhR) significantly attenuated activation of DRE by tunicamycin. These results elucidated the novel potential of tunicamycin as an activator of the AhR – DRE signaling pathway