Chemical chaperones reduce ER stress and restore glucose homeostasis in a mouse model of type 2 diabetes

Endoplasmic reticulum (ER) stress is a key link between obesity, insulin resistance, and type 2 diabetes. Here, we provide evidence that this mechanistic link can be exploited for therapeutic purposes with orally active chemical chaperones. 4-Phenyl butyric acid and taurine-conjugated ursodeoxycholic acid alleviated ER stress in cells and whole animals. Treatment of obese and diabetic mice with these compounds resulted in normalization of hyperglycemia, restoration of systemic insulin sensitivity, resolution of fatty liver disease, and enhancement of insulin action in liver, muscle, and adipose tissues. Our results demonstrate that chemical chaperones enhance the adaptive capacity of the ER and act as potent antidiabetic modalities with potential application in the treatment of type 2 diabetes.     

Changes in surface water table depth and soil physical properties after harvest and establishment of loblolly pine (Pinus taeda L.) in Atlantic coastal plain wetlands of South Carolina

The surface water table is an important factor determining soil chemical, physical and biological processes, and thus affects the functions of forested wetlands. The objective of this study was to assess surface water table dynamics from timber harvesting through early forest plantation establishment in a coastal plain wetland area located in the southeastern United States. Simulated harvesting patterns included two replicates of clear-cutting when soils were dry (dry-weather harvest), three replicates of clear-cutting when soils were wet (wet-weather harvest), and one replicate of uncut control in three 20 ha wetland loblolly pine (Pinus taeda L.) forests of ages 20, 23 and 25 years. After harvesting, two site preparation levels (non-bed and bed; bedding is a tillage process of preparing a series of parallel ridges) were randomly assigned to both dry-weather and wet-weather harvested plots, while an additional level (mole-plow+bed) was assigned only to the wet-weather harvested plots. The harvest treatments were designed to create a broad gradient of surface soil disturbance, while the site preparation treatments were done to encompass a range of site drainage and aeration conditions. Areal changes in soil bulk density, macro- and total porosities, and saturated hydraulic conductivity following harvesting were quantified. The depths of water table were recorded at monthly intervals on a 20 m×20 m grid across the 15 clear-cut and three uncut control plots (a total of 1409 PVC slotted wells) over 6 years (1992–1998), subdivided into five periods: pre-harvest, post-harvest, site preparation, and first year and second year after forest plantation establishment. The results showed that compared to the uncut control, the surface water table depth during a 1-year post-harvest period rose 14 cm for the dry-weather harvested site and 21 cm for the wet-weather harvested site. The difference in the water table rise between the two harvest treatments was small during the dormant season (<2 cm) but large during the growing season (>10 cm). These results indicate the large influence of tree removal on the surface hydrology in forested wetlands and the strong impact of wet-weather harvesting on transpiring ground vegetation due to a larger surface area of soil disturbance. Bedding initially lowered water tables on both dry-weather and wet-weather harvested sites. However, this effect decreased rapidly during the first 2 years after forest plantation establishment. Among all treatments, the dry-weather harvested sites without bedding presented the fastest recovery of water table depth to that of the non-harvested references, suggesting that bedding may have been a further disturbance with respect to wetland surface hydrology.     

Effect of ingested concentrate and components of sake on epidermal permeability barrier disruption by UVB irradiation

Daily topical applications of the concentrate of sake (CS) have been shown to reduce epidermal barrier disruption in murine skin caused by ultraviolet B (UVB) radiation, while one of the components of sake, ethyl alpha-D-glucoside (alpha-EG), also reduces barrier disruption. We confirmed the effect of oral ingestion of various doses of CS on epidermal barrier disruption caused by UVB irradiation in hairless mice. Then, to identify the effective components, we quantitatively analyzed alpha-EG, organic acids, and glycerol, the main components of CS, and examined the effect of various concentration of each on barrier disruption. alpha-EG and organic acids showed comparable results to CS itself, and transepidermal water loss levels in murine skin were significantly decreased as compared with the control. Furthermore, an investigation of the dose dependency of these agents was performed and the results showed the significant effectiveness of alpha-EG. In addition, red wine concentrate (WC) and beer concentrate (BC) were examined in order to confirm the unique effects of CS. Similar effects were not found with WC and BC.     

Effect of light intensity on diurnal differences in the supply of cell wall components to the innermost surface of developing S<Subscript>2</Subscript> layers of tracheids in <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>

We investigated the effect of light intensity on diurnal differences in secondary wall formation of tracheids. Saplings of Cryptomeria japonica were grown in growth chambers with light intensity cycles set for 12-h high light: 12-h low light by combining two of four light intensity levels: 1.5, 2.8, 4.3, and 10.0 klx. Volumetric changes of differentiating cells were monitored by measuring the tangential strain on the inner bark surface, and the innermost surface of developing secondary walls of differentiating tracheids during the high-light and low-light periods was observed by field-emission scanning electron microscopy. Changes in the aspects of the innermost surface of developing secondary walls and the tangential strain corresponded to changes in the light intensity level. Cellulose microfibrils were clearly observed when the light intensity was high (10.0 or 4.3 klx) and the volume of differentiating cells was low, while abundant amorphous material was observed when the light intensity was lowest (1.5 klx) and the cells were turgid, regardless of the light intensity cycle. These results suggest that the diurnal periodicity in the supply of cell wall components to developing secondary walls is associated with changes in light intensity during the photoperiodic cycle.     

Changes in morphological phenotypes and essential oil components in lavandin (Lavandula × intermedia Emeric ex Loisel.) transformed with wild-type strains of Agrobacterium rhizogenes

Hairy roots were induced from leaf-derived calli of lavandin (Lavandula × intermedia Emeric ex Loisel.) by infection with wild-type strains of Agrobacterium rhizogenes, A-5 (MAFF 02-10265) and A-13 (MAFF 02-10266). A-5-inoculated calli formed hairy roots more efficiently than A-13 ones. The transgenic shoots could be obtained from hairy root segments mediated by each Agrobacterium strain. However, different plant growth regulators were required for efficient adventitious shoot formation in each strain. In A-5, the most efficient adventitious shoot formation rate of 23.8% was observed in a medium with 4.4 × 10⁻⁶ M of 6-benzylaminopurine. On the other hand, a significantly higher rate of 13.2% was detected in a medium with 4.0 × 10⁻⁷ M of N-(2-chloro-4-pyridyl)-N′-phenylurea in A-13. Most of the regenerated plants showed dwarfism with closed internodes and extensive lateral branching, which were typical characteristics of ‘hairy root syndrome’. On the other hand, only nine of the 45 regenerated plants formed flower buds in early June, a delay of about one month compared with nontransgenic regenerated plants. The floral stalks and spikes of these plants were very short, resulting in a compacted form. Many regenerants showed a significantly lower productivity of essential oil than nontransgenic regenerants. Moreover, the relative percentage of the linalyl-cation-derived compounds, linalool and linalyl acetate, decreased in most of the regenerated plants. Compact plants with the ability of flower bud formation are assumed to be valuable not only for lavandin breeding, but also for clarifying the interaction between rol genes expression and essential oil production.     

Imatinib elicited a favorable response in a dog with a mast cell tumor carrying a c-kit c.1523A>T mutation via suppression of constitutive KIT activation

Target therapy using the tyrosine kinase inhibitor imatinib is one of the new therapeutic approaches for canine mast cell tumors (MCTs). In the present report, we demonstrate a clinical response to imatinib in a dog with MCT carrying a c-kit c.1523A>T mutation. Moreover, the effect of this mutation on the phosphorylation status of KIT and the inhibitory potency of imatinib on the phosphorylation of the mutant KIT were examined in vitro. A dog with a MCT tumor mass on the right forelimb sole with lymph node metastasis and mastocytemia was treated with imatinib. The MCT mass markedly shrank and mastocytemia became undetectable with 2 weeks of treatment. The lymph node enlarged by metastasis became normal in size with 5 weeks of treatment. From the sequencing analysis of c-kit in tumor cells, a substitution mutation c.1523A>T that alters the amino acid composition (p.Asn508Ile) within the extracellular domain of KIT was identified. The mutant KIT expressed on 293 cells showed ligand-independent phosphorylation and imatinib suppressed this phosphorylation in a dose-dependent manner. From these findings, imatinib was considered to elicit a clinical response in a canine case of MCT via inhibition of the constitutively activated KIT caused by a c-kit c.1523A>T mutation.     

Differentiation of uterine natural killer cells in pregnant SCID (scid/scid) mice

To determine whether functional T- and B-cells can affect differentiation and/or proliferation of uterine natural killer (uNK) cells, their numbers in SCID mice (genotype, C.B.-17/Icr-scid/scid) were compared with those of control mice (genotype, C.B.-17/Icr-+/+) on days 8, 12 and 16 of pregnancy. Using biotinylated-Dolichos biflorus agglutinin (DBA) lectin staining, uNK cells can be readily classified into 4 subtypes, I to IV, from immature to mature types. The number of uNK cells was significantly lower in the decidua basalis of SCID mice than in that of control mice on day 8 of pregnancy. Particularly, the number of uNK cells of immature subtype II was significantly lower in SCID mice than in the control mice. By day 12, however, the uNK cell number in the SCID mice reached the same level as that of the control mice. It is likely that uNK cell differentiation in SCID mice was delayed during the early placentation period due to a lack of functional T and B cells.