Impaired cortical oxygenation is related to mood disturbance resulting from three nights of sleep restriction

Sleep and Biological Rhythms - Chronic sleep restriction adversely effects cognitive performance and mood, resulting in accidents and economic loss. We examined the effects of three nights of sleep...     

In Vitro Binding of Wheat-Germ Proteins to the 5'-Upstream Region of the rolC Gene of Ri Plasmid

In vitro binding of nuclear proteins from wheat germ to the5'-upstream region of the rolC gene of Ri plasmid was investigated.The specific DNA sequences interacting with proteins were detectedby DNase I footprinting. (Received October 8, 1990; Accepted November 30, 1990)     

Adipolin/C1qdc2/CTRP12 protein functions as an adipokine that improves glucose metabolism

Obesity is a major risk factor for the development of insulin resistance and type 2 diabetes. Adipose tissue secretes various bioactive molecules, referred to as adipokines, whose dysregulation can mediate changes in glucose homeostasis and inflammatory responses. Here, we identify C1qdc2/CTRP12 as an insulin-sensitizing adipokine that is abundantly expressed by fat tissues and designate this adipokine as adipolin (adipose-derived insulin-sensitizing factor). Adipolin expression in adipose tissue and plasma was reduced in rodent models of obesity. Adipolin expression was also decreased in cultured 3T3-L1 adipocytes by treatment with inducers of endoplasmic reticulum stress and inflammation. Systemic administration of adipolin ameliorated glucose intolerance and insulin resistance in diet-induced obese mice. Adipolin administration also reduced macrophage accumulation and proinflammatory gene expression in the adipose tissue of obese mice. Conditioned medium from adipolin-expressing cells diminished the expression of proinflammatory cytokines in response to stimulation with LPS or TNFα in cultured macrophages. These data suggest that adipolin functions as an anti-inflammatory adipokine that exerts beneficial actions on glucose metabolism. Therefore, adipolin represents a new target molecule for the treatment of insulin resistance and diabetes.     

Microsomal glutathione S-transferase 1 in the retinal pigment epithelium: protection against oxidative stress and a potential role in aging

High oxygen tension, exposure to light, and the biochemical events of vision generate significant oxidative stress in the retina and the retinal pigment epithelium (RPE). Understanding the mechanisms and basis of susceptibility to progressive retinal diseases involving oxidative damage such as age-related macular degeneration (AMD) remains a major challenge. Here microsomal glutathione S-transferase (MGST1) is shown to be a dominant, highly expressed enzyme in bovine and mouse RPE microsomes that displays significant reduction activity toward synthetic peroxides, oxidized RPE lipids, and oxidized retinoids. This enzymatic reduction activity (GPx) can be partially neutralized with a monoclonal anti-MGST1 antibody developed in this study. MGST1-transfected HEK293 cells exhibited greater viability (70 +/- 4% survival) compared with untransfected control cells (46 +/- 4% survival) when challenged with 20 microM H(2)O(2), and greater viability of MGST1-transfected cells following challenge with oxidized docosahexaenoic acid was also observed. Cultured ARPE19 cells transfected with silencing MGST1 siRNAs exhibited lower expression of MGST1 (12% and 26% of the controls) and significantly lower GPx activity (44 +/- 13%) and, thus, were more susceptible to oxidative damage. Immunoblotting revealed that the in vivo expression of MGST1 in mouse RPE decreases 3-4-fold with age, to trace levels in 18-month-old mice. GPx activity in the RPE was also found to be reduced in 12-month-old mice to approximately 67%. These results support an important protective function for MGST1 against oxidative insult in the RPE that decreases with age and suggest that this enzyme may play a role in the development of age-related diseases such as AMD.     

Al(3+) interaction sites of calmodulin and the Al(3+) effect on target binding of calmodulin

The interaction between calmodulin (CaM) and Al(3+) was studied by spectroscopic methods. Heteronuclear two-dimensional NMR data indicated that peaks related to the both lobes and middle of the central helix of CaM are largely affected by Al(3+). But chemical shift perturbation suggested that overall conformation of Ca(2+)-loaded CaM is not changed by Al(3+) binding. It is thought that Al(3+) interaction to the middle of the central helix is a key for the property of CaM's target recognition. If the structure and/or flexibility of the central helix are/is changed by Al(3+), target affinity to CaM must be influenced by Al(3+). Thus, we performed surface plasmon resonance experiments to observe the effect of Al(3+) on the target recognition by CaM. The data clearly indicated that target affinity to CaM is reduced by addition of Al(3+). All the results presented here support a hypothesis that Al(3+) may affect on the Ca(2+) signaling pathway in cells.     

Modeling population dynamics of a tea pest with temperature-dependent development: predicting emergence timing and potential damage

The tea leaf roller, Caloptilia theivora Walsingham (Lepidoptera: Gracillariinae), is one of the serious pests of tea plants in Japan. To understand the mechanism of seasonal occurrence of this insect pest, we developed a population dynamics model that explicitly incorporates the temperature-dependent development of the pest. The model predictions were compared with observed captures in pheromone traps at the experimental site of the Kagoshima Tea Experiment Research Station in Japan. The results showed that the emergence timing of the insect pest observed in the field was determined primarily by temperature. The relationship between the timing of adult emergence and the leaf damage level was also studied using a logistic regression model. The infestation level decreased as the interval between the adult peak emergence date and the date of tea plucking increased, implying that asynchrony between plant phenology and emergence of the insect pest is a critical factor reducing damage level. We examined how the damage level changes according to global warming. Increased temperature made the timing of insect appearance forward and enhance asynchrony of plant–pest phenology. Therefore, reduction of damage level by the insect pest is expected under global warming.     

Precursor structure of egg proteins in the coral Galaxea fascicularis

In the egg of the reef coral Galaxea fascicularis, four proteins (named GfEP-1 to -4) are stored in high abundance. In the present study, a cDNA containing a full-length open reading frame for GfEP-1 was cloned, and the translated protein sequence was compared to the N-terminal sequences of GfEP-2, -3, and -4. GfEP-1 and -2 were shown to be generated by processing of a precursor of 1439 amino acids, and GfEP-3 turned out to be a partial fragment of GfEP-2. The precursor protein contained regions which exhibited similarities to vitellogenins (Vgs) in bilaterian animals (oviparous vertebrates and invertebrates including nematodes, arthropods, and molluscs). This study reports the first cloning and characterization of a full-length cDNA encoding a Vg in a non-bilaterian animal, and argues that the emergence of Vg as a precursor of egg yolk proteins predated the divergence of the cnidarian and bilaterian lineages.     

Reassignment of a rare sense codon to a non-canonical amino acid in Escherichia coli

The immutability of the genetic code has been challenged with the successful reassignment of the UAG stop codon to non-natural amino acids in Escherichia coli. In the present study, we demonstrated the in vivo reassignment of the AGG sense codon from arginine to l-homoarginine. As the first step, we engineered a novel variant of the archaeal pyrrolysyl-tRNA synthetase (PylRS) able to recognize l-homoarginine and l-N⁶-(1-iminoethyl)lysine (l-NIL). When this PylRS variant or HarRS was expressed in E. coli, together with the AGG-reading tRNA^Pyl_CCU molecule, these arginine analogs were efficiently incorporated into proteins in response to AGG. Next, some or all of the AGG codons in the essential genes were eliminated by their synonymous replacements with other arginine codons, whereas the majority of the AGG codons remained in the genome. The bacterial host''s ability to translate AGG into arginine was then restricted in a temperature-dependent manner. The temperature sensitivity caused by this restriction was rescued by the translation of AGG to l-homoarginine or l-NIL. The assignment of AGG to l-homoarginine in the cells was confirmed by mass spectrometric analyses. The results showed the feasibility of breaking the degeneracy of sense codons to enhance the amino-acid diversity in the genetic code.     

Establishment and characterization of a novel ovarian clear cell carcinoma cell line,TU-OC-2, with loss of ARID1A expression

A new cell line of human ovarian clear cell carcinoma (CCC), TU-OC-2, was established and characterized. The cells were polygonal in shape, grew in monolayers without contact inhibition and were arranged in islands like pieces of a jigsaw puzzle. The chromosome numbers ranged from 41 to 96. A low rate of proliferation was observed and the doubling time was 37.5 h. The IC₅₀ values of cisplatin, 7-ethyl-10-hydroxycamptothecin (SN38), which is an active metabolite of camptothecin, and paclitaxel were 7.7 μM, 17.7 nM and 301 nM, respectively. The drug sensitivity assay indicated that TU-OC-2 was sensitive to SN38, but resistant to cisplatin and paclitaxel. Mutational analysis revealed that TU-OC-2 cells have no mutations of PIK3CA in exons 9 and 20 and of TP53 in exons 4–9. We observed the loss of ARID1A protein expression in TU-OC-2 cells by western blot analysis and in the original tumor tissue by immunohistochemistry. This cell line may be useful for studying the chemoresistant mechanisms of CCC and exploring novel therapeutic targets such as the ARID1A-related signaling pathway.