Synthesis and preliminary biological evaluation of truncated zoanthenol analogues

Zoanthamines are a family of marine alkaloids that have complex heptacyclic structures and are reported to be interleukin-6 modulators. While the structure of zoanthamines, especially the ABC-ring portion, is similar to that of steroids, the CDEFG-ring portion, composed of aminoacetal and lactone core, is a unique structural element. In this report, we designed and synthesized ABC-ring 6 and CDEFG-ring 7, which are truncated analogues of the northern and southern hemispheres of zoanthenol 5, respectively, and which incorporate all of the functionality of each hemisphere. A preliminary SAR study suggested that the hydrochloride of the CEFG-ring portion is an active pharmacophore for suppressing the growth of interleukin-6-dependent MH60 cells.     

Public perception of the cultural value of Satoyama landscape types in Japan

Using the public survey “The Top 100 Japanese Rural Landscapes” conducted by Asahi Shimbun Newspaper Company in 2008, this study attempted to analyze public perception of rural landscapes and their cultural value. A total of 3,024 nominated sites were given coordinates and combined with land use and topographic datasets using a GIS, and classified into several landscape types using cluster analysis. Keywords that appeared frequently in the nominations were extracted using a text-mining tool and used to interpret the cultural value of each type. As a result, the nominated sites were divided into six types. The majority of nominated sites were classified as Forest Type (forest 88%) and associated with the keywords traditional rural lifestyle, and sites to visit. Mixed Type (forest 50%, paddy field 20%, and other agricultural fields 10%) were associated with biodiversity and conservation activities, and Paddy Field Type (paddy field 60%) was significantly associated with Furusato (Home). Urban and Suburban Type sites (built-up land 50%) were concentrated in the Kanto Region and nominated mainly by local citizens for their nature activities. There was also the Other Agricultural Type, which made up 10% each of the nominations, and the Coastal Type, which was mostly nominated by ocean-related organizations and rarely nominated by the general public. Additionally, the concept of biodiversity seemed to be difficult for the public to understand. The results indicated that future studies should consider public perception of the variety of Satoyama landscapes and how it should be incorporated into future Satoyama management strategy.     

Effects of living at two ambient temperatures on 24-h blood pressure and neuroendocrine function among obese and non-obese humans: a pilot study

The effects of environmental temperature on blood pressure and hormones in obese subjects in Japan were compared in two seasons: summer vs winter. Five obese (BMI, 32?±?5 kg/m²) and five non-obese (BMI, 23 ±3 kg/m²) men participated in this experiment at latitude 35°10′ N and longitude 136°57.9′ E. The average environmental temperature was 29?±?1 °C in summer and 3?±?1 °C in winter. Blood samples were analyzed for leptin, ghrelin, catecholamines, thyroid stimulating hormone (TSH), free thyroxine (fT₄), free triiodothyronine (fT₃), total cholesterol, triglycerides, insulin and glucose. Blood pressure was measured over the course of 24 h in summer and winter. A Japanese version of the Profile of Mood States (POMS) questionnaire was also administered each season. Systolic and diastolic blood pressures in obese men were significantly higher in winter (lower environmental temperatures) than in summer (higher environmental temperatures). Noradrenaline and dopamine concentrations were also significantly higher at lower environmental temperatures in obese subjects, but ghrelin, TSH, fT₃, fT₄, insulin and glucose were not significantly different in summer and winter between obese and non-obese subjects. Leptin, total cholesterol and triglyceride concentrations were significantly higher in winter in obese than non-obese men. Results from the POMS questionnaire showed a significant rise in Confusion at lower environmental temperatures (winter) in obese subjects. In this pilot study, increased blood pressure may have been due to increased secretion of noradrenaline in obese men in winter, and the results suggest that blood pressure control in obese men is particularly important in winter.     

Measurement of resistant starch content in cooked rice and analysis of gelatinization and retrogradation characteristics

Digestion-resistant starch (RS) has many physiologic functions. The RS content is measured by enzymatically degrading flour samples according to the method of the Association of Official Analytical Chemists. Experiments have been performed with wheat, corn, and other grains, but there are no data for cooked rice grains in the form ingested by humans. Thus, we investigated a method to measure RS that is suitable for cooked rice grains using rice cultivars that are reported to differentially increase postprandial blood glucose in humans. Using a method for cooking individual rice grains and optimized enzyme reaction conditions, we established an RS measurement method. We also found that the amylopectin crystal condition affects the RS content measured using our method.     

Parkinson's disease-associated mutations in α-synuclein and UCH-L1 inhibit the unconventional secretion of UCH-L1

Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) is an intracellular protein abundantly expressed in neurons, and a mutation in UCH-L1 has been identified in familial Parkinson’s disease. UCH-L1 has been detected in human cerebrospinal fluid, raising the possibility that UCH-L1 is secreted from neurons. In the present study, we showed that a portion of UCH-L1 is secreted from cultured cells. The secretion of D30K UCH-L1, which lacks ubiquitin binding activity, was decreased compared with that of wild-type UCH-L1, while the secretion of C90S UCH-L1, which lacks hydrolase activity, was not. Treatment with Brefeldin A, an inhibitor of vesicle transport from the endoplasmic reticulum to the Golgi, did not block the secretion of UCH-L1, indicating that UCH-L1 is secreted by an unconventional pathway. The UCH-L1 sequence from Leu-32 to Leu-39 is similar to the unconventional secretory signal sequence of engrailed 2, and substitution of the leucines within this region (L32S/L32A/L34S/L34A/L39S/L39A) reduced the secretion of UCH-L1. We found that the Parkinson’s disease-associated mutation I93M in UCH-L1 decreased the secretion of I93M UCH-L1. In addition, Parkinson’s disease-linked α-synuclein mutants reduced the secretion of endogenous UCH-L1. Our results indicate that the hydrolase activity is not necessary for the unconventional secretion of UCH-L1, and suggest that the ubiquitin binding activity and the sequence between Leu-32 and Leu-39 are involved in the secretion. Moreover, the secretion of UCH-L1 could be involved in the pathology of Parkinson’s disease.     

Silkworm apolipophorin protein inhibits Staphylococcus aureus virulence

Silkworm hemolymph inhibits hemolysin production by Staphylococcus aureus. We purified a factor in the silkworm hemolymph responsible for this inhibitory activity. The final fraction with the greatest specific activity contained 220- and 74-kDa proteins. Determination of the N-terminal amino acid sequence revealed that the 220- and 74-kDa proteins were apolipophorin I and apolipophorin II, respectively, indicating that the factor was apolipophorin (ApoLp). The purified ApoLp fraction showed decreased expression of S. aureus hla encoding α-hemolysin, hlb encoding β-hemolysin, saeRS, and RNAIII, which activate the expression of these hemolysin genes. Injection of an anti-ApoLp antibody into the hemolymph increased the sensitivity of silkworms to the lethal effect of S. aureus. Hog gastric mucin, a mammalian homologue of ApoLp, decreased the expression of S. aureus hla and hlb. These findings suggest that ApoLp in the silkworm hemolymph inhibits S. aureus virulence and contributes to defense against S. aureus infection and that its activity is conserved in mammalian mucin.     

Visualization of Sialidase Activity in Mammalian Tissues and Cancer Detection with a Novel Fluorescent Sialidase Substrate

Sialidase removes sialic acid from sialoglycoconjugates and plays crucial roles in many physiological and pathological processes. Various human cancers express an abnormally high level of the plasma membrane-associated sialidase isoform.Visualization of sialidase activity in living mammalian tissues would be useful not only for understanding sialidase functions but also for cancer diagnosis. However, since enzyme activity of mammalian sialidase is remarkably weak compared with that of bacterial and viral sialidases, it has been difficult to detect sialidase activity in mammalian tissues. We synthesized a novel benzothiazolylphenol-based sialic acid derivative (BTP-Neu5Ac) as a fluorescent sialidase substrate. BTP-Neu5Ac can visualize sialidase activities sensitively and selectively in acute rat brain slices. Cancer cells implanted orthotopically in mouse colons and human colon cancers (stages T3-T4) were also clearly detected with BTP-Neu5Ac. The results suggest that BTP-Neu5Ac is useful for histochemical imaging of sialidase activities.     

Requirement of the SH4 and tyrosine-kinase domains but not the kinase activity of Lyn for its biosynthetic targeting to caveolin-positive Golgi membranes

Background

The Src-family non-receptor-type tyrosine kinase Lyn, which is often associated with chemotherapeutic resistance in cancer, localizes not only to the plasma membrane but also Golgi membranes. Recently, we showed that Lyn, which is synthesized in the cytosol, is transported from the Golgi to the plasma membrane along the secretory pathway. However, it is still unclear how Golgi targeting of newly synthesized Lyn is regulated.

Methods

Subcellular localization of Lyn and its mutants was determined by confocal microscopy.

Results

We show that the kinase domain, but not the SH3 and SH2 domains, of Lyn is required for the targeting of Lyn to the Golgi, whereas the N-terminal lipids of the Lyn SH4 domain are not sufficient for its Golgi targeting. Although intact Lyn, which colocalizes with caveolin-positive Golgi membranes, can traffic toward the plasma membrane, kinase domain-deleted Lyn is immobilized on caveolin-negative Golgi membranes.

General significance

Besides the SH4 domain, the Lyn kinase domain is important for targeting of newly synthesized Lyn to the Golgi, especially caveolin-positive transport membranes. Our results provide a novel role of the Lyn catalytic domain in the Golgi targeting of newly synthesized Lyn in a manner independent of its kinase activity.