The involvement of reactive oxygen species (ROS) and p38 mitogen-activated protein (MAP) kinase in TRAIL/Apo2L-induced apoptosis

To determine the apoptotic signaling pathway which tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) induced, we investigated the contribution of reactive oxygen species (ROS), p38 mitogen-activated protein (MAP) kinase and caspases in human adenocarcinoma HeLa cells. Here we show that upon TRAIL/Apo2L exposure there was pronounced ROS accumulation and activation of p38 MAP kinase, and that activation of caspases and apoptosis followed. Pretreatment with antioxidants such as glutathione or estrogen attenuated TRAIL/Apo2L-induced apoptosis through a reduction of ROS generation and diminished p38 MAP kinase and caspase activation. The p38 MAP kinase inhibitor SB203580 prevented apoptosis through a blockage of caspase activation, although ROS generation was not attenuated. Furthermore, the pan-caspase inhibitor Z-Val-Ala-DL-Asp-fluoromethyl ketone fully prevented apoptosis, while neither ROS accumulation nor p38 MAP kinase activation were affected. Therefore, our results suggest that TRAIL/Apo2L-induced apoptosis is mediated by ROS-activated p38 MAP kinase followed by caspase activation in HeLa cells.     

Estrogen receptor stereochemistry: ligand binding and hormonal responsiveness

Estrogen stimulation of the uterus produces a spectrum of biochemical responses that are customarily linked together. This report is an overview of a series of studies by our laboratory investigating the role of different ligand structures in eliciting hormonal responses. Diethylstilbestrol (DES) and certain structural analogs, indenestrol A (IA), indenestrol B (IB), and pseudo-DES, were used as probes to segregate various genomic responses previously considered interrelated, most notably the events of specific protein synthesis and DNA synthesis. These compounds have weak uterotrophic activity; however, they interact with high affinity specifically with mouse uterine estrogen receptors (ERs). All of them produce stoichiometrically similar amounts of ER complex in the nucleus. Indenestrol A and IB possess a single chiral carbon atom and exist as a mixture of enantiomers (ENTs). Competitive binding assays of pure ENTs and cytosolic ERs demonstrated a stereochemical chiral preference for the IA isomer but not IB. This preference was also evident from nuclear ER occupancy experiments. Biologic activity of the IA ENTs also demonstrated differences as seen by receptor binding. Ornithine decarboxylase (ODC) activity was stimulated 600% by DES and partially by IA (rac). All of the ODC activity produced by IA (rac) was due to the IA(C3)-S ENT. Uterine DNA synthesis was measured after treatment with the IA compounds. Indenestrol A (rac) increased DNA synthesis to 40% of the level seen with DES. The weak ENTs showed no activity and the active ENTs were weaker than the IA racemic. These compounds should be useful probes for studying the individual responses involved in estrogen-induced uterine growth.(ABSTRACT TRUNCATED AT 250 WORDS)     

Annual Variation of Soil Respiration and Precipitation in a Temperate Forest (<Emphasis Type="Italic">Quercus serrata</Emphasis> and <Emphasis Type="Italic">Carpinus laxiflora</Emphasis>) Under East Asian Monsoon Climate

The consequence of changing pattern of precipitation on soil CO₂ emission is poorly understood in montane forest ecosystems under monsoon climate in Asia. In this paper, the results of 3-year field measurements are reported on the annual soil respiration (R _s) from a temperate deciduous broad-leaved forest (Quercus serrata and Carpinus laxiflora) in Korea, and its interannual variations are examined associated with changing precipitation. Based on biweekly chamber measurements from 2001 to 2004, the annual soil CO₂ emission averaged to be 7.8 t C ha⁻¹ with an annual variability of ∼20%. The soil temperature explained 22–97% of seasonal variations of R _s each year whereas the water-filled porosity (WFP) and precipitation pattern had a major effect on the observed interannual variation. The optimum values of WFP during the main growing season depended not only on the amount but also on the intensity and frequency of precipitation. These results indicate that the changes in catchment hydrology can significantly alter the carbon sink/source strength of forest ecosystems in monsoon Asia.     

Change in Self-Reported Health Status among Immigrants in the United States: Associations with Measures of Acculturation

Although acculturation may have positive effects for immigrants, including better socioeconomic profiles and increased occupational opportunities, their health profiles deteriorate with longer duration in the U.S. Prior research indicates that increasing acculturation is associated with some poorer health outcomes among immigrants in the U.S. However, most of these studies have used length of stay or English language proficiency as proxies for acculturation, and have mainly examined self-reported “current” health outcomes. This study advances knowledge on associations between acculturation and health among immigrants by explicitly examining self-reported “change” in health since immigration, in relation to acculturation-related variables. We use data from the New Immigrant Survey (NIS; 2003-2004), a cross-sectional study of legal immigrants to the U.S. In addition to testing more conventionally examined proxies of acculturation (length of stay and English proficiency), we also examine English language use and self-reported change in diet. Multivariable logistic regression analyses on 5,982 participants generally supported previous literature indicating a deleterious impact of acculturation, with increasing duration of stay and greater self-reported change in diet being associated with a poorer change in health since moving to the U.S. Although English language proficiency and use were associated with greater odds of reporting a worse change in health when examined individually, they were non-significant in multivariable models including all acculturation measures. Findings from this study suggest that when taking into account multiple measures of acculturation, language may not necessarily indicate unhealthy assimilation and dietary change may be a pathway leading to declines in immigrant health. Increasing duration in the U.S. may also reflect the adoption of unhealthy behaviors, as well as greater exposure to harmful sources of psychosocial stress including racial and anti-immigrant discrimination. Our study suggests that multiple indicators of acculturation may be useful in examining the effect of acculturation on changes in health among immigrants.     

Growth hormone-releasing peptide-biotin conjugate stimulates myocytes differentiation through insulin-like growth factor-1 and collagen type I

Based on the potential beneficial effects of growth hormone releasing peptide (GHRP)-6 on muscle functions, a newly synthesized GHRP-6-biotin conjugate was tested on cultured myoblast cells. Increased expression of myogenic marker proteins was observed in GHRP-6-biotin conjugate-treated cells. Additionally, increased expression levels of insulin-like growth factor-1 and collagen type I were observed. Furthermore, GHRP-6-biotin conjugate-treated cells showed increased metabolic activity, as indicated by increased concentrations of energy metabolites, such as ATP and lactate, and increased enzymatic activity of lactate dehydrogenase and creatine kinase. Finally, binding protein analysis suggested few candidate proteins, including desmin, actin, and zinc finger protein 691 as potential targets for GHRP6-biotin conjugate action. These results suggest that the newly synthesized GHRP-6-biotin conjugate has myogenic stimulating activity through, at least in part, by stimulating collagen type I synthesis and several key proteins. Practical applications of the GHRP-6-biotin conjugate could include improving muscle condition. [BMB Reports 2015; 48(9): 501-506]     

Multiple estrogen binding sites in the uterus: stereochemistry of receptor and non-receptor binding of diethylstilbestrol and its metabolites

Indenestrol A (IA), an oxidative metabolite of the synthetic estrogen diethylstilbestrol (DES), has high binding affinity for estrogen receptor in mouse uterine cytosol but possesses weak biological activity. Racemic mixture of optically active [3H]indenestrol A (IA-Rac) was separated and purified into individual enantiomers on a semi-preparative scale by HPLC with a Chiralpak OP(+) column. The structure-activity relationship was investigated among the [3H]IA enantiomers (IA-R and IA-S) and [3H]DES through direct saturation binding assays using mouse uterine cytosol. Specific binding curves and Scatchard plots were obtained for each [3H]ligand; DES, IA-Rac, IA-R and IA-S. IA-S enantiomer (Kd = 0.67) binds to the estrogen receptor with the same affinity as DES (Kd = 0.71) and four times higher affinity than IA-R (Kd = 2.56). The number of binding sites for IA-S is approximately the same as estradiol, DES and IA-Rac while IA-R binds far fewer sites than the other ligands. Saturation binding assays indicated that [3H]DES and [3H]IA enantiomers exhibited a higher level of non-specific binding to the cytosol receptor compared to estradiol which has a low level of non-specific binding. These binding studies led to the detection of an additional binding component for the stilbestrol compounds in estrogen target tissue cytosol preparations. Sucrose density gradient separation assays under low salt conditions showed that both [3H]DES and [3H]IA compounds bound to the 8S form of the receptor, the same as E2. But, in addition both DES and IA bound to another binding component in 4S region. The binding to the 4S component were partially displaced by the addition of excess unlabeled E2 and DES. Further characterization of the 4S component is described.     

Euryhelmis squamula (Digenea: Heterophyidae) Recovered from Korean Raccoon Dog,Nyctereutes procyonoides koreensis,in Korea

In this study, we intended to describe an unrecorded species of heterophyid trematode recovered from the small intestine of a Korean raccoon dog, Nyctereutes procyonoides koreensis, in Korea. A total of 13 small flukes were collected from a deceased Korean raccoon dog which was found in Chuncheon-si, Gangwon-do, Korea in May 2017. The trematode body were covered with many small spines, rectangular, broader than long, 807–1,103 μm long and 1,270–1,550 μm wide. Oral sucker in the anterior end slightly smaller than acetabulum. Pharynx muscular and well developed. Esophagus relatively long and sigmoid. Acetabulum small and located at median in anterior 2/5 portion. Ceca bifurcated at the anterior of genital pore and acetabulum and terminated at testis level. Testes larger, deeply lobed and located at the near of posterior end of body. Ovary small, triangular and located at the slight left of median and the anterior of left testis. Vitelline follicles dendritic and extend from the middle level of esophagus to the posterior portion of body. Eggs embryonated, operculated, small and 33–35×15–16 μm in size. Based on the morphological characteristics, the small heterophyid flukes recovered from the small intestines of Korean raccoon dog, N. procyonoides koreensis, were identified as Euryhelmis squamula (Digenea: Heterophyidae). Accordingly, this species of heterophyid flukes is to be a new trematode fauna in Korea by this study.