KDT501, a Derivative from Hops,Normalizes Glucose Metabolism and Body Weight in Rodent Models of Diabetes

Aims/Hypothesis

We developed KDT501, a novel substituted 1,3-cyclopentadione chemically derived from hop extracts, and evaluated it in various in vitro and in vivo models of diabetes and insulin sensitivity.

Methods

KDT501 was evaluated for anti-inflammatory effects in monocyte/macrophage cells; agonistic activity for peroxisome proliferator-activated receptors (PPAR); lipogenesis and gene expression profile in human subcutaneous adipocytes. Body composition, glucose, insulin sensitivity, and lipids were assessed in diet-induced obesity (DIO) mice and Zucker Diabetic Fatty (ZDF) rats after oral administration.

Results

KDT501 mediated lipogenesis in 3T3L1 and human subcutaneous adipocytes; however, the gene expression profile of KDT501 differed from that of the full PPARγ agonist rosiglitazone, suggesting that KDT501 has pleiotropic biological activities. In addition, KDT501 showed only modest, partial PPARγ agonist activity and exhibited anti-inflammatory effects in monocytes/macrophages that were not observed with rosiglitazone. In a DIO mouse model, oral administration of KDT501 significantly reduced fed blood glucose, glucose/insulin AUC following an oral glucose bolus, and body fat. In ZDF rats, oral administration of KDT501 significantly reduced fed glucose, fasting plasma glucose, and glucose AUC after an oral glucose bolus. Significant, dose-dependent reductions of plasma hemoglobin A1c, weight gain, total cholesterol, and triglycerides were also observed in animals receiving KDT501.

Conclusion

These results indicate that KDT501 produces a unique anti-diabetic profile that is distinct in its spectrum of pharmacological effects and biological mechanism from both metformin and pioglitazone. KDT501 may thus constitute a novel therapeutic agent for the treatment of Type 2 diabetes and associated conditions.     

CD8α Dendritic Cells Drive Establishment of HSV-1 Latency

It is generally accepted that CD8 T cells play the key role to maintain HSV-1 latency in trigeminal ganglia of ocularly infected mice. Yet, comparably little is known about the role of innate immunity in establishment of viral latency. In the current study, we investigated whether CD8α DCs impact HSV-1 latency by examining latency in the trigeminal ganglia (TG) of wild-type (WT) C57BL/6 versus CD8α^−/− (lack functional CD8 T cells and CD8α⁺ DCs), CD8β^−/− (have functional CD8α⁺ T cells and CD8α⁺ DCs), and β2m^−/− (lack functional CD8 T cells but have CD8α⁺ DCs) mice as well as BXH2 (have functional CD8 T cells but lack CD8α⁺ DCs) versus WT C3H (have functional CD8α T cells and CD8α⁺ DCs) mice. We also determined whether the phenotype of CD8α^−/− and BXH2 mice could be restored to that of WT mice by adoptive transfer of WT CD8⁺ T cells or bone marrow (BM) derived CD8α⁺ DCs. Our results clearly demonstrate that CD8α DCs, rather than CD8 T cells, are responsible for enhanced viral latency and recurrences.     

Increased yield of high purity recombinant human interferon-gamma utilizing reversed phase column chromatography

Increasing therapeutic applications for recombinant human interferon-gamma (rhIFN-gamma), an antiviral proinflammatory cytokine, has broadened interest in optimizing methods for its production and purification. We describe a reversed phase chromatography (RPC) procedure using Source-30 matrix in the purification of rhIFN-gamma from Escherichia coli that results in a higher yield than previously reported. The purified rhIFN-gamma monomer from the RPC column is refolded in Tris buffer. Optimal refolding occurs at protein concentrations between 50 and 100 microg/ml. This method yields greater than 90% of the dimer form with a yield of 40 mg/g cell mass. Greater than 99% purity is achieved with further purification over a Superdex G-75 column to obtain specific activities of from 2 x 10(7) to 4 x 10(7)IU/mg protein as determined via cytopathic antiviral assay. The improved yield of rhIFN-gamma in a simple chromatographic purification procedure promises to enhance the development and therapeutic application of this biologically potent molecule.     

Energetics of wet-suit diving in Japanese male breath-hold divers

The present study was undertaken to investigate energy balance in professional male breath-hold divers in Tsushima Island, Japan. In 4 divers, rectal (Tre) and mean skin (Tsk) temperatures and rate of O2 consumption (VO2) were measured during diving work in summer (27 degrees C water) and winter (14 degrees C water). Thermal insulation and energy costs of diving work were estimated. In summer, comparisons were made of subjects clad either in wet suits (protected) or in swimming trunks (unprotected), and in winter, they wore wet suits. The average Tre in unprotected divers decreased to 36.4 +/- 0.2 degrees C at the end of 1-h diving work, but in protected divers it decreased to 37.2 +/- 0.3 degrees C in 2 h in summer and to 36.9 +/- 0.1 degree C in 1.5 h in winter. The average Tsk of unprotected divers decreased to 28.0 +/- 0.6 degrees C in summer and that of protected divers decreased to 32.9 +/- 0.5 degrees C in summer and 28.0 +/- 0.3 degrees C in winter. Average VO2 increased 190% (from 370 ml/min before diving to 1,070 ml/min) in unprotected divers in summer, but in protected divers it rose 120% (from 360 to 780 ml/min) in summer and 110% (from 330 to 690 ml/min) in winter. Overall thermal insulation (tissue and wet suit) calculated for protected divers was 0.065 +/- 0.006 degree C X kcal-1 X m-2 X h-1 in summer and 0.135 +/- 0.019 degree C X kcal-1 X m-2 X h-1 in winter.(ABSTRACT TRUNCATED AT 250 WORDS)     

Human auditory brain stem response during induced hyperthermia

A continuous monitoring of auditory brain stem response (ABR) and esophageal (Tes) and rectal temperatures (Tre) were recorded in male undergraduate subjects to investigate a relationship between the interpeak latencies (IPLs) and core temperature. The average change of Tes (36.8-39.5 degrees C) was achieved by immersing the subjects in a temperature-controlled water bath (30-42 degrees C). The IPLs became shorter with the rise in body temperature and were correlated with both Tes and Tre. The average slopes for IPL(I-III) and IPL(I-V) were significantly higher than those for IPL(III-V). The present study of humans indicated that changes of IPL(I-III) and IPL(I-V) were 0.11 and 0.16 ms, respectively, per 1 degree C change in core temperature during induced hyperthermia.     

Regulation of uterine 5 alpha-reductase type 1 in mice.

A null mutation in the murine gene encoding steroid 5 alpha-reductase type 1 (5 alpha R1) leads to failure of normal parturition at term. This observation, together with the finding that mRNA levels of uterine 5 alpha R1 increase significantly at term in normal pregnant animals, indicates that 5 alpha R1 plays an important role in murine parturition. The current studies were conducted to elucidate the regulation of 5 alpha R1 in uterine tissues of nonpregnant and pregnant animals. Nonpregnant, ovariectomized ICR mice were treated with vehicle (control), 17 beta-estradiol (E(2)), progesterone (P(4) ), or E(2)+P(4) for 3 days. Thereafter, uterine tissues were obtained for histology, quantification of 5 alpha R1 specific activity, and Northern blot analysis of 5 alpha R1 mRNA expression. The 5 alpha R1 enzyme activity was significantly increased in animals treated with E(2)+P(4). However, activity was much less in uterine tissues from E(2)+P(4)-treated animals than in uterine tissues from pregnant animals near term. To evaluate further the regulation of 5 alpha R1 during gestation, mice underwent unilateral tubal ligation before timed matings. The 5 alpha R1 activity increased eightfold in uterine tissues from the fetal horn from Gestational Days 12 to 18. This temporal pattern in 5 alpha R1 activity paralleled marked increases in uterine diameter. Taken together, these studies indicate that expression of 5 alpha R1 is regulated by E(2)+P(4) in uterine tissues. Whereas E(2) alone is insufficient to induce enzyme activity, E(2) may be required to increase P(4) receptors and, thereby, mediate the effects of P(4) on 5 alpha R1 gene expression. Further increases in enzyme activity during late gestation are mediated by fetal occupancy, possibly through stretch-induced increases in endometrial growth. Thus, like other genes involved in parturition, expression of 5 alpha R1 is regulated by both hormonal and fetal-derived signaling pathways.     

Rapid classification of partial waxy wheats using PCR-based markers.

Mutations in the three homeologous waxy loci Wx-A1, Wx-B1, and Wx-D1 of a waxy wheat line have previously been characterized at the molecular level. Using combinations of these mutations, six types of partial waxy wheat plus wild type and waxy wheat (types 1-8) can be produced. Here, we describe primer sets for all three loci that can be used under a single set of conditions, allowing 32 lines to be characterized as types 1-8 in a single PCR run using a 96-well plate. Using multiplex PCR, mutations at the Wx-B1 and Wx-D1 loci can be identified in a single PCR, reducing the number of reactions necessary to identify and select the desired partial waxy wheat line. A single multiplex PCR can be used to detect all three mutations when products are analyzed using capillary electrophoresis on a microchip device. The PCR conditions and primers are effective with a number of cultivars from other countries, indicating that the mutations found at the Wx-A1 and Wx-B1 loci of these cultivars likely have the same origins as the mutations in the corresponding loci of the waxy wheat line used in this study. The PCR selection method described here is an easy and effective alternative to the commonly used SDS-PAGE methods for identification of null alleles.     

Vertical distribution in and isolation of bacteria from Lake Vanda: an Antarctic lake

Vertical distribution of bacteria in Lake Vanda, an Antarctic meromictic lake, was examined by the acridine orange epifluorescence direct count method. Total bacteria were 10⁴–10⁵ cells · ml^–1 in the water at 55 m depth and above, and increased drastically to 10⁷ cells · ml^–1 in the bottom water. Filamentous or long rodshaped bacteria occurred at a high frequency in the upper layers, but in the bottom layers most bacteria were coccoidal or short rods. Mean bacterial cell volume in water of between 10 m and 60 m deep was fairly large compared with common bacterial populations in seawater and lake water. Aerobic heterotrophic bacteria were recovered from the water of a depth of 30 m and above, and were assumed to belong to Caulobacter. Viable heterotrophic bacteria were not recovered from the high salinity deep water by media prepared with the same deep water. Phototrophic purple non-sulphur bacteria were isolated by enrichment cultures from water at 55 m depth.     

Sevoflurane-induced structural changes in a four-alpha-helix bundle protein

The mechanisms whereby volatile general anesthetics reversibly alter protein function in the central nervous system remain obscure. Using three different spectroscopic approaches, evidence is presented that binding of the modern general anesthetic sevoflurane to the hydrophobic core of a model four-alpha-helix bundle protein results in structural changes. Aromatic residues in the hydrophobic core reorient into new environments upon anesthetic binding, and the protein as a whole becomes less dynamic and exhibits structural tightening. Comparable structural changes in the predicted in vivo protein targets, such as the gamma-aminobutyric acid type A receptor and the N-methyl-D-aspartate receptor, may underlie some, or all, of the behavioral effects of these widely used clinical agents.     

Effects of castor oil on lipid metabolism in rats

Weanling rats were given diets contained castor oil (CAO-diet), coconut oil (CO-diet), or high-oleic safflower oil (HO-diet) each 10% (wt). No growth retardations were observed on the CAO-diets. The CAO-diet group showed significantly lower serum cholesterol and hepatic triacylglycerols than the HO-diet group. Ricinoleic acid was found at an extremely low level in perirenal adipose tissue.