Biological Intelligence of Rare Earth Elements in Animal Cells

Recent progress in bioinorganic chemistry studies of rare earth elements (REE) in animal cells was outlined, and the definition of REE′s biological intelligence as well as their mechanism were also explained. The migration of REE from weathering rocks to the environment is accelerated by various anthropogenic activities, which can eventually result in the entrance of REE into animal and human bodies via food chain. REE can be found in body tissues such as brain, blood, muscle as well as bone. Based on their geochemical properties, REE in low dose show their unique biological intelligence by intervening in the process of signal transduction and its regulation, arteriosclerosis and blood clotting prevention, anticancer, and the promotion of cellular defense enzymes′ activities, nucleic acid metabolism enzymes as well as ATPases, etc. The meaning of REE′s biological intelligence refers to physicochemical properties-based capability to choose the targets (e.g., biometals) in biomolecules for the chelation or replacement of REE, and change the structures and functions of biomolecules, and consequently impact or control the biological functions or behaviors in living organisms. The regulation of various cellular processes caused by REE is mainly via antagonism or replacement of essential target biometals like calcium or via chelation of organic molecules, thereby embodying the unparalleled biological intelligence of REE. Additionally, the dosage effect of REE was also discussed from the angles of yin-yang dichotomy, bioavailability, entropy and evolution. In order to make full use of REE′s biological intelligence in the application for medicine, more detailed studies concerning dosage effect of REE and REE bioaccumulation in organisms should be conducted in future research.

Selenium Regulation of Selenium-dependent Glutathione Peroxidases in Animals and Transfected CHO Cells

Glutathione peroxidase (GPX1) was the first identified selenium-dependent enzyme, and this enzyme has been most useful as a biochemical indicator of selenium (Se) status and the parameter of choice for determining Se requirements. We have continued to study Se regulation of GPX1 to better understand the underlying mechanism and to gain insight into how cells themselves regulate nutrient status. In progressive Se deficiency in rats, GPX1 activity,protein and mRNA all decrease in a dramatic, coordinated and exponential fashion such that Se-deficient GPX1 mRNA levels are 6-15% of Sexadequate levels. mRNA levels for other Sedependent proteins are far less decreased in the same animals. The mRNA levels for a second Se-dependent peroxidase, phospholipid hydroperoxide glutathione peroxidase (GPX4 ), are little affected by Se deficiency, demonstrating that Se regulation of GPX1 is unique. Se regulation of GPX1 activity in growing male and female rats shows that the Se requirernent is 100 ng/g diet, based on liver GPX1 activity; use of GPX1 mRNA as the parameter indicates that the Se requirement is nearer to 50 ng Se/g diet in both male and female rats. This approach will readily detect an altered dietary Se requirement, as shown by the incremental increases in dietary Se requirement by 150, 100 or 50 ng Se/g diet in Seudeficient rat pups repleted with Se for 3, 7 or 14 d, respectively. Studies with CHO cells stably transfected with recombinant GPX1 also show that overexpression of GPX1 does not alter the minimum level of media Se necessary for Se-adequate levels of GPX1 activity or mRNA. We hypothesize that classical GPX1 has an integral biological role in the mechanism used by cells to regulate Se status,making GPX1 an especially useful and effective parameter for determining Se requirements in animals

Effects of Samarium Chloride on Porcine Thyroid Cells in Vitro

To study the effects of various concentrations of SmCl3 on the morphology and functions of porcine thyroid cells in vitro, the methods of the electron microscope and radioimmunoassay were used. The investigation showed that when the thyroid cells were cultured in the presence of 0.001 and 0.01 mmol/L SmCl3, the measured levels of tetraiodothyronine (T4) were much higher than those in control cells and iodine uptake by thyroid cells increased, and the cells appeared to be active functional morphology under the electron microscope. When the thyroid cells were cultured in the presence of 0.1 mmol/L SmCl3, the levels of T4 and iodine uptake by cells decreased as compared with those in control cells, and the morphological changes of the cells presented an inactive functional state. From the evidences mentioned above, it demonstrates that very low concentrations (0.001 and 0.01 mmol/L) of SmCl3 promote synthesis and secretion of thyroid hormone, whereas a higher concentration (0.1 mmol/L of SmCl3) inhibits the synthesis and secretion of thyroid hormone.

STUDY ON INFLAMMATORY CELLS IN BALF OF SMOKE-INDUCED CHRONIC BRONCHITIS RAT MODEL

Objective To establish a smoke-induced chronic bronchitis rat model and evaluate the patho-logical change semi-quantitatively, and study the characteristics of the inflammatory cells in the bronchoalveolar lav-age fluid (BALF) in various stages. Methods Chronic bronchitis sequential rat model was established by passively inhaling smoke mixture. Experiments were performed in 30 young male Sprague-Dawley rats, which comprised 5 groups in random, i.e.,4 chronic bronchitis model groups and 1 control group. After stained with hematoxylin and eosin, the specimens were studied by semi-quantitative method to evaluate the morphologic changes in various stages. Meanwhile, the inflammatory cells of the BALF and the activity of myeloperoxidase (MPO) of lung tissue were analysed. Results During the process of the chronic bronchitis, the pathologic score was increasing as time went on, and the typical morphologic changes of chronic bronchitis emerged in the group 7 weeks. The total number of inflammatory cells in BALF was increasing as time went on, correlated with the pathologic scores (P <0.01). And the percentage of lymphocyte increased as well as positively correlated with pathologic scores (P < 0. 05) , whereas that of macrophage decreased and negatively correlated with pathologic scores (P <0. 05). The MPO lever of lung tissue was correlated with the pathologic scores (P < 0. 01). But the percentage of the neutrophil in the BALF was just in a high level during the first week, then it maintained relatively lower. Conclusion Smoke-induced chronic bronchitis is a slowly progressive inflammation process. The model we established is convenient and simple for the longitudinal study on the inflammatory process of chronic bronchitis and the therapy in the early stage. The semi-quantitative evaluation for the pathological change is with much more value. During the inflammatory sequential process of early stage of chronic bronchitis, the cellular characteristics are similar to that of the common chronic inflammation.

Intracellular detection of cytokine expression with four-color flow cytometry in pregnant NOD/SCID mice

The aim of this study was to evaluate the relationship between the embryo resorption rate （RR） and the status of local immunity at the feto-maternal interface in pregnant NOD/SCID mice. RR was calculated in NOD/SCID x NOD/SCID mice and compared with non-immunodeficiency BALB/c × BALB/c mice on day 13.5 of gestation. Intraeellular detection of cytokine expression was performed with four-color flow cytometry to identify the functional subsets of lymphocytes in NOD/SCID mice before being bred or during pregnancy. No statistically supported difference in RRs was observed between NOD/SCID × NOD/SCID and control BALB/c × BALB/c mice. Accordingly, although multiple immunodeficits were confirmed in NOD/SCID mice, the percentages of several functional cell subsets were spontaneously altered during pregnancy, and this may be correlated with the roughly normal pregnancy outcomes observed in these mice. The spontaneous alteration of cell percentages at the feto-maternal interfaee in NOD/SCID mice may be of benefit to the pregnancy outcomes.

Two-photon imaging of lymphoma cells targeted by gold nanoparticles

Gold nanoparticles （NPs） have highly efficient multi-photon-induced luminescence. In this paper, we record the two-photon images of gold NPs, lymphoma cell line Karpas 299, and Karpas 299 incubated with 30-nm-diameter gold NPs and ACT-1 antibody conjugates （Au30-ACT-1 conjugates） by using a multi-photon microscopy system. Due to the specific conjugation of ACT-1 antibody and cell membrane receptor CD25, gold NPs are only bound to the surface of cell membrane of Karpas 299. The luminescence intensity of gold NPs is higher than that of cells at 750-nm laser excitation. By comparing the images of Karpas 299 cells incubated with and without gold NPs, it is found that by means of gold NPs, we can get clear cell images with lower excitation power. Their excellent optical and chemical properties make gold NPs an attractive contrast agent for cellular imaging.

A new exploration on the creation of grafted breast cancer model for MA891 cells in TA2 mice

Animal experimental systems are particularly useful for the study of human breast cancer. An ideal model shoulcl be easy to use, closely mimicking human physiopathology and has a stable tumor morbidity. The cell line MA891 was established from a spontaneous TA2 mouse mammary carcinoma by Cancer Institute of Chinese Academy of Medical Sciences. 3 Some researches indicated that MA891 had a very low immunogenecity and maintained a high metastatic potential in vivo. So it has been used as a better grafted mouse tumor model for studying cancer physiopathology and metastasis in human for years. However, about the biological characteristic and the histopathologic feature of this model there has been a lack of investigations.