2,3,7,8‑Tetrachlorodibenzo‑p‑dioxin suppresses the growth of human liver cancer HepG2 cells in vitro: Involvement of cell signaling factors.

The aryl hydrocarbon receptor (AHR) is transcriptionally active in the form of a heterodimer with the AHR nuclear translocator, which then binds to the xenobiotic responsive element. AHR was originally discovered via its ligand, the polychlorinated hydrocarbon, 2,3,7,8‑tetrachlorodibenzo‑p‑dioxin (TCDD). In this study, we investigated whether TCDD regulates the growth of human liver cancer HepG2 cells in vitro. TCDD (0.1‑100 nM) was found to exert suppressive effects on the colony formation and proliferation of HepG2 cells, and stimulatory effects on the death of HepG2 cells when the cells reached subconfluence. The effects of TCDD on the HepG2 cells were abolished by culture with CH223191, an inhibitor of AHR signaling. The effects of TCDD were dependent on the concentration of serum, which contains various signaling factors. The effects of TCDD were not potentiated by culture with tumor necrosis factor‑α, which activates the signaling of nuclear factor‑κB (NF‑κB). The results of western blot analysis revealed that TCDD increased the protein levels of p53, Rb, p21, and regucalcin, which are suppressors of the growth of tumor cells. Moreover, TCDD enhanced the NF‑κB p65, β‑catenin, signal transducer and activator of transcription 3 (STAT3), Ras and Akt levels. Thus, the findings of this study indicate that TCDD may suppress liver cancer cell growth through various signaling pathways, mediated by AHR and its‑related co‑factors. Of note, the effects of TCDD were found to be potentiated by gemcitabine, which induces nuclear DNA damage in cancer cells, suggesting that their combined use may have potential as a suppressor of tumor cell growth

Role of carotenoid β-cryptoxanthin in bone homeostasis

Bone homeostasis is maintained through a balance between osteoblastic bone formation and osteoclastic bone resorption. Aging induces bone loss due to decreased osteoblastic bone formation and increased osteoclastic bone resorption. Osteoporosis with its accompanying decrease in bone mass is widely recognized as a major public health problem. Nutritional factors may play a role in the prevention of bone loss with aging. Among various carotenoids (carotene and xanthophylls including beta (β)-cryptoxanthin, lutein, lycopene, β-carotene, astaxanthin, and rutin), β-cryptoxanthin, which is abundant in Satsuma mandarin orange (Citrus unshiu MARC.), has been found to have a stimulatory effect on bone calcification in vitro. β-cryptoxanthin has stimulatory effects on osteoblastic bone formation and inhibitory effects on osteoclastic bone resorption in vitro, thereby increasing bone mass. β-cryptoxanthin has an effect on the gene expression of various proteins that are related osteoblastic bone formation and osteoclastic bone resororption in vitro. The intake of β-cryptoxanthin may have a preventive effect on bone loss in animal models for osteoporosis and in healthy human or postmenopausal women. Epidemiological studies suggest a potential role of β-cryptoxanthin as a sustainable nutritional approach to improving bone health of human subjects. β-Cryptoxanthin may be an osteogenic factor in preventing osteoporosis in human subjects

Inhibitory effect of calcium-binding protein regucalcin on Ca2+-activated DNA fragmentation in rat liver nuclei

AbstractIncubation of isolated rat liver nuclei with ATP, NAD+, and micromolar Ca2+ concentrations of various metal ions resulted in extensive DNA hydrolysis. Half-maximal activity occurred with 1.0 μM Ca2+ added, and saturation of the process was observed with 10 μM Ca2+, The Ca2+ (10 μM)-activated DNA fragmentation was inhibited by the presence of Ca2+-binding protein regucalcin isolated from rat liver cytosol. The inhibitory effect of regucalcin was complete at 0.5 μM. At 25μM Ca2+ added, such an effect of regucalcin (1.0μM) was not seen, Regucalcin also inhibited Ca2+-activated DNA fragmentation in the presence or calmodulin (10 and 20 μg). The results show that regucalcin can inhibit the Ca2+-activated DNA fragmentation due to binding the metal, suggesting a role in regulation of liver nuclear functions

Ki-energy (Life-energy) Stimulates Osteoblastic Cells and Inhibits the Formation of Osteoclast-like Cells in Bone Cell Culture Models

Some practitioners of the Nishino Breathing Method (NBM) were found to have a higher bone density than the average values of age- and gender-matched non-practitioners. Using bone cell culture models, we investigated a possible mechanism behind this observation. For the study of bone mineralization, we performed the following two experiments using cultured osteoblastic MC3T3-E1 cells: (i) Kozo Nishino, a Japanese Ki expert, sent Ki-energy to the cells once for 5 or 10 min after they were seeded in culture dishes in the presence of 10% fetal bovine serum (FBS). They were incubated for 72 h and the cells were counted. The number in the dish with 10-min Ki-exposure was significantly greater than that in the control (P < 0.01 with n = 8). We performed a reverse transcription-polymerase chain reaction (RT–PCR) study using these cells, but the mRNA expressions did not change significantly. (ii) After cells were incubated for 72 h without Ki-exposure (in the presence of FBS), they were further cultured for 48 h (in the absence of FBS) to promote differentiation. At the beginning of the second culture stage, Ki was applied once for 10 min. After 48 h, RT–PCR was performed. The mRNA expressions which are related to bone mineralization, such as Runx2, α1(I) collagen, alkaline phosphatase and osteocalcin, increased significantly (P < 0.05 and n = 4 for all). For the bone resorption study, we used mouse marrow cultures, which can form osteoclast-like cells in the presence of (1–34) parathyroid hormone (PTH), and stimulate resorption. We exposed these cells to Ki-energy twice for the duration of 5 or 10 min on day 0 and day 4. On day 7, the cells were counted. The number of osteoclast-like cells in dishes with Ki exposure was significantly smaller than those in control dishes (P < 0.05 with n = 5). The difference between 5-min exposure and 10-min exposure was not statistically significant. All of our data suggest that the Ki-effect on osteoporosis should be further explored

Growth Inhibition of Cultured Human Liver Carcinoma Cells by Ki-energy (Life-energy): Scientific Evidence for Ki-effects on Cancer Cells

‘Ki-energy’ (life-energy) is believed to increase the immune activity of its practitioners. It has also been shown to cause neuropsychological effects. We undertook this study to obtain objective and scientific evidence as to whether or not a ‘Ki-effect’ could inhibit the growth of cultured cancer cells. Cultured human liver carcinoma cells, HepG2, were used. A Japanese Ki-expert held his fingers toward the cells in culture dishes for 5 or 10 min. After culturing for 24 h, we measured cell numbers, protein concentration per cell, certain mRNA expressions and the synthesis of regucalcin. The results were compared with those for control cells (non-treated cells). We found that the number of cells in the Ki-exposed groups were less than those in the controls by 30.3 and 40.6% with 5 and 10 min Ki-exposure, respectively. The protein content per cell in the Ki-exposed groups (5 and 10 min) was higher than that in the control groups by 38.8 and 62.9%, respectively. These results were statistically significant. Using RT–PCR, we found that the mRNA expression for c-myc, a tumor stimulator gene, was decreased, while that for regucalcin, which suppresses DNA synthesis, was increased. Our molecular biological studies and mathematical model analysis demonstrated that Ki-energy inhibited cancer cell division. The data also indicate that the Ki-effects involve some form of infrared radiation from the human body. This study suggests the possibility that Ki-energy may be beneficial for cancer patients because it suppresses cancer cell growth, and at the same time, it stimulates immune functions of the patients

A Chandrasekhar Mass Progenitor for the Type Ia Supernova Remnant 3C 397 from The Enhanced Abundances of Nickel and Manganese

Despite decades of intense efforts, many fundamental aspects of Type Ia supernova (SNe Ia) remain elusive. One of the major open questions is whether the mass of the exploding white dwarf (WD) is close to the Chandrasekhar limit. Here we report the detection of strong K-shell emission from stable Fe-peak elements in the Suzaku X-ray spectrum of the Type Ia supernova remnant (SNR) 3C 397. The high Ni/Fe and Mn/Fe mass ratios (0.11-0.24 and 0.018-0.033, respectively) in the hot plasma component that dominates the K-shell emission lines indicate a degree of neutronization in the SN ejecta which can only be achieved by electron captures in the dense cores of exploding WDs with a near-Chandrasekhar mass. This suggests a single-degenerate origin for 3C 397, since Chandrasekhar mass progenitors are expected naturally if the WD accretes mass slowly from a companion. Together with other results supporting the double-degenerate scenario, our work adds to the mounting evidence that both progenitor channels make a significant contribution to the SN Ia rate in star-forming galaxies.Comment: Accepted by ApJL; 6 pages with 4 figures and 1 tabl

Royal Jelly Prevents Osteoporosis in Rats: Beneficial Effects in Ovariectomy Model and in Bone Tissue Culture Model

Royal jelly (RJ) has been used worldwide for many years as medical products, health foods and cosmetics. Since RJ contains testosterone and has steroid hormone-type activities, we hypothesized that it may have beneficial effects on osteoporosis. We used both an ovariectomized rat model and a tissue culture model. Rats were divided into eight groups as follows: sham-operated (Sham), ovariectomized (OVX), OVX given 0.5% (w/w) raw RJ, OVX given 2.0% (w/w) RJ, OVX given 0.5% (w/w) protease-treated RJ (pRJ), OVX given 2.0% (w/w) pRJ, OVX given 17β-estradiol and OVX given its vehicle, respectively. The Ovariectomy decreased tibial bone mineral density (BMD) by 24%. Administration of 17β-estradiol to OVX rats recovered the tibial BMD decrease by 100%. Administration of 2.0% (w/w) RJ and 0.5–2.0% (w/w) pRJ to OVX rats recovered it by 85% or more. These results indicate that both RJ and pRJ are almost as effective as 17β-estradiol in preventing the development of bone loss induced by ovariectomy in rats. In tissue culture models, both RJ and pRJ increased calcium contents in femoral-diaphyseal and femoral-metaphyseal tissue cultures obtained from normal male rats. However, in a mouse marrow culture model, they neither inhibited the parathyroid hormone (PTH)-induced calcium loss nor affected the formation of osteoclast-like cells induced by PTH in mouse marrow culture system. Therefore, our results suggest that both RJ and pRJ may prevent osteoporosis by enhancing intestinal calcium absorption, but not by directly antagonizing the action of PTH

Discriminating the Progenitor Type of Supernova Remnants with Iron K-Shell Emission

Supernova remnants (SNRs) retain crucial information about both their parent explosion and circumstellar material left behind by their progenitor. However, the complexity of the interaction between supernova ejecta and ambient medium often blurs this information, and it is not uncommon for the basic progenitor type (Ia or core-collapse) of well-studied remnants to remain uncertain. Here we present a powerful new observational diagnostic to discriminate between progenitor types and constrain the ambient medium density of SNRs solely using Fe K-shell X-ray emission. We analyze all extant Suzaku observations of SNRs and detect Fe K alpha emission from 23 young or middle-aged remnants, including five first detections (IC 443, G292.0+1.8, G337.2-0.7, N49, and N63A). The Fe K alpha centroids clearly separate progenitor types, with the Fe-rich ejecta in Type Ia remnants being significantly less ionized than in core-collapse SNRs. Within each progenitor group, the Fe K alpha luminosity and centroid are well correlated, with more luminous objects having more highly ionized Fe. Our results indicate that there is a strong connection between explosion type and ambient medium density, and suggest that Type Ia supernova progenitors do not substantially modify their surroundings at radii of up to several parsecs. We also detect a K-shell radiative recombination continuum of Fe in W49B and IC 443, implying a strong circumstellar interaction in the early evolutionary phases of these core-collapse remnants.Comment: Accepted by ApJL; 5 pages with just 1 table and 1 figur

High hydrostatic pressure induces slow contraction in mouse cardiomyocytes

Cardiomyocytes are contractile cells that regulate heart contraction. Ca2+ flux via Ca2+ channels activates actomyosin interactions, leading to cardiomyocyte contraction, which is modulated by physical factors (e.g., stretch, shear stress, and hydrostatic pressure). We evaluated the mechanism triggering slow contractions using a high-pressure microscope to characterize changes in cell morphology and intracellular Ca2+ concentration ([Ca2+]i) in mouse cardiomyocytes exposed to high hydrostatic pressures. We found that cardiomyocytes contracted slowly without an acute transient increase in [Ca2+]i, while a myosin ATPase inhibitor interrupted pressure-induced slow contractions. Furthermore, transmission electron microscopy showed that, although the sarcomere length was shortened upon the application of 20 MPa, this pressure did not collapse cellular structures such as the sarcolemma and sarcomeres. Our results suggest that pressure-induced slow contractions in cardiomyocytes are driven by the activation of actomyosin interactions without an acute transient increase in [Ca2+]i