Expression of low density lipoprotein receptor gene in human placenta during pregnancy

Mammalian cells require cholesterol as a structural component of plasma membranes. It is also required for placental steroid synthesis. De novo synthesis of cholesterol is limited in human placenta and cholesterol is obtained mainly from plasma low density lipoprotein (LDL). Cholesterol delivery from LDL is mediated by receptor-mediated uptake and the receptor amount is the most important factor for cellular delivery. Thus, the regulation of receptor synthesis is important for placental development and function. Since the regulation of LDL receptor gene expression has not been studied in human placenta, LDL receptor mRNA was measured in placentae of 5-40 weeks of gestation by hybridization of RNA with 32P-labeled cDNA for human LDL receptor. Two mRNA species for LDL receptor were demonstrated by Northern blot analysis. The longer mRNA [5.3 kilobases (kb)] was much more abundant than the shorter mRNA (3.7 kb). The amount of 5.3 kb mRNA was highest early in gestation and decreased during pregnancy. However, the amount of 3.7 kb mRNA did not change appreciably during gestation. Dot blot analysis of 26 placental mRNAs obtained from various stages of gestation revealed a negative correlation between LDL receptor mRNA and gestation (r = -0.76, P less than 0.001). Considering the rapid growth of the trophoblast during gestation, especially in the first and the second trimester, increased expression of the LDL receptor gene and subsequent translation are expected for efficient cholesterol uptake to provide a sufficient substrate for cell growth. Possible mechanisms for the appearance of two mRNA species for LDL receptor are also discussed.     

Optimization of a medium for the production of 1,2-epoxytetradecane by Nocardia corallina B-276

Summary A medium for the production of 1,2-epoxytetradecane from 1-tetradecene by Nocardia corallina B-276 was optimized. The activity of cells producing 1,2-epoxytetradecane increased when cell growth was suppressed by limiting nitrogen or potassium ion in the medium. Mg²⁺ was found to be essential for the production of 1,2-epoxide. Cell mass was increased, without reducing production of 1,2-epoxide, by increasing the concentration of yeast extract and limiting the concentration of potassium ion. The concentration of 1,2-epoxytetradecane reached 80 g/l in 6 days after optimization and the yield of 1,2-epoxytetradecane was 65 mol% based on consumed 1-tetradecene. Long chain 1,2-epoxyalkanes containing 13–17 carbon atoms also were produced under these conditions.     

Biological control of arrowhead scale,Unaspis yanonensis,by parasitic wasps introduced from the People's Republic of China

In 1980, the authors went to the People's Republic of China in search of the natural enemies of the arrowhead scale,Unaspis yanonensis Kuwana, and succeeded in collecting 2 species of parasitic wasps of this pest namelyPhyscus fulvus Compere & Annecke andAphytis yanonensis DeBach & Rosen. The development, reproduction and longevity ofAphytis yanonensis were studied under constant temperature conditions. The number of generations a year was estimated to be from 10 to 12. Reproduction ofPhyscus fulvus is arrhenotokous, and development from egg to adult required 25 days at 25°C and 33 days at 20°C. The number of generations was estimated at 4 to 5 a year. Both parasites were released in several citrus groves in the Shizuoka Prefecture, of central Japan during June and July, 1981. They successfuly hibernated and each stage of development was found from March to December, 1982. They are considered to be potentially highly effective against the arrowhead scale. We have succeeded in establishing bothAphytis yanonensis andPhyscus fulvus in several districts in the Shizuoka Prefecture.

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Résumé Les auteurs se rendirent en 1980 en République Populaire de Chine pour entreprendre une recherche sur les ennemis naturels deUnaspis yanonensis Kuwana et découvrirent 2 espèces d'hyménoptères parasites de la cochenille. Les ennemis naturels introduits furentPhyscus fulvus Compere & Annecke etAphytis yanonensis DeBach & Rosen. La croissance, la reproduction et la longévité deA. yanonensis furent étudiées à température constante. Le nombre de générations annuelles a été estimé entre 10 et 12. La reproduction deP. fulvus est de type arrhénotoque et la durée du développement de l'œuf à l'adulte, nécessite 25 jours à 25°C et 33 jours à 20°C. Le nombre de générations annuelles a été estimé à 4 ou 5. Les 2 parasites ont été libérés dans plusieurs plantations d'agrumes de la préfecture de Shizuoka, région centrale du Japon pendant les 2 mois de juin et juillet 1981 et ont hiverné avec succès. Chaque stade de développement a été observé de mars à décembre 1982. Ces parasites sont considérés comme des ennemis naturels hautement efficaces de la cochenille. Nous avons introduit avec succèsAphytis yanonensis etPhyscus fulvus en provenance de Chine dans diverses régions de la préfecture de Shizuoka, partie centrale du Japon.

     

Immunocytochemical localization of cathepsins B,H, and L in the rat gastro-duodenal mucosa

Summary Cathepsins B, H, and L are representative cysteine proteinases in lysosomes of a large variety of cells. Previous immunochemical studies indicated the presence of these enzymes also in the gastrointestinal wall. Using specific antisera, the cellular and subcellular distribution of cathepsins B, H, and L in rat gastric (oxyntic and pyloric part) and duodenal mucosa was investigated by light and electron microscopical immunocytochemistry. The subtypes of cathepsins were distributed differently in the cellular constituents of the epithelia: Cathepsin B was localized to lysosomes of all cells except goblet cells. Cathepsin H was found predominantly in gastric parietal cells (lysosomes) and in secretion granules of pyloric gastrin and duodenal cholecystokinin cells. Cathepsin L immunoreactivities were weak and restricted to a minority of cells (gastric mucous cells, enterocytes). Interstitial cells of the lamina propria immunoreactive for cathepsins H and L were identified as macrophages. The present findings suggest a dual function of cathepsins in the gastro-duodenal mucosa. They (1) cleave enzymatically proteins and peptides ingested in lysosomes, and (2) they may be involved in the processing of biologically active peptides (enteric hormones) from their precursor proteins.     

Circulating Levels of Fatty Acid-Binding Protein Family and Metabolic Phenotype in the General Population

Objective

Fatty acid-binding proteins (FABPs) are a family of 14-15-kDa proteins, and some FABPs have been to be used as biomarkers of tissue injury by leak from cells. However, recent studies have shown that FABPs can be secreted from cells into circulation. Here we examined determinants and roles of circulating FABPs in a general population.

Methods

From the database of the Tanno-Sobetsu Study, a study with a population-based cohort design, data in 2011 for 296 subjects on no medication were retrieved, and FABP1∼5 in their serum samples were assayed.

Results

Level of FABP4, but not the other isoforms, showed a gender difference, being higher in females than in males. Levels of all FABPs were negatively correlated with estimated glomerular filtration rate (eGFR), but a distinct pattern of correlation with other clinical parameters was observed for each FABP isoform; significant correlates were alanine aminotransferase (ALT), blood pressure (BP), and brain natriuretic peptide (BNP) for FABP1, none besides eGFR for FABP2, age, BP, and BNP for FABP3, age, waist circumference (WC), BP, BNP, lipid variables, high-sensitivity C-reactive protein (hsCRP), and HOMA-R for FABP4, and age, WC, BP, ALT, BNP, and HOMA-R for FABP5. FABP4 is the most strongly related to metabolic markers among FABPs. In a multivariate regression analysis, FABP4 level was an independent predictor of HOMA-R after adjustment of age, gender, WC, BP, HDL cholesterol, and hsCRP.

Conclusions

Each FABP isoform level showed a distinct pattern of correlation with clinical parameters, although levels of all FABPs were negatively determined by renal function. Circulating FABP4 appears to be a useful biomarker for detecting pre-clinical stage of metabolic syndrome, especially insulin resistance, in the general population.     

Adipogenetic effects of retrofractamide A derivatives in 3T3-L1 cells

In a previous study, retrofractamide A from the fruit of Piper chaba was shown to promote adipogenesis in 3T3-L1 cells. In the present study, retrofractamide A and its derivatives were synthesized, and their adipogenetic effects in 3T3-L1 cells were examined. Among the tested compounds, an amide composed of 9-(3′,4′-methylenedioxyphenyl)-nona-2E,4E,8E-trienoic acid and an n-butyl or n-pentyl amine showed strongest activity. Moreover, the amide with the n-pentyl amine moiety significantly increased the uptake of 2-deoxyglucose into the cells, and also increased the mRNA levels of adiponectin, peroxisome proliferator-activated receptor γ2 (PPARγ2), glucose transporter 4 (GLUT4), fatty acid-binding protein (aP2), and CCAAT/enhancer-binding protein (C/EBP) α and β in a similar manner as the PPARγ agonist troglitazone, although it had less agonistic activity against PPARγ.     

Sodium‐powered stators of the bacterial flagellar motor can generate torque in the presence of phenamil with mutations near the peptidoglycan‐binding region

The bacterial flagellar motor powers the rotation that propels the swimming bacteria. Rotational torque is generated by harnessing the flow of ions through ion channels known as stators which couple the energy from the ion gradient across the inner membrane to rotation of the rotor. Here, we used error‐prone PCR to introduce single point mutations into the sodium‐powered Vibrio alginolyticus/Escherichia coli chimeric stator PotB and selected for motors that exhibited motility in the presence of the sodium‐channel inhibitor phenamil. We found single mutations that enable motility under phenamil occurred at two sites: (i) the transmembrane domain of PotB, corresponding to the TM region of the PomB stator from V. alginolyticus and (ii) near the peptidoglycan binding region that corresponds to the C‐terminal region of the MotB stator from E. coli. Single cell rotation assays confirmed that individual flagellar motors could rotate in up to 100 µM phenamil. Using phylogenetic logistic regression, we found correlation between natural residue variation and ion source at positions corresponding to PotB F22Y, but not at other sites. Our results demonstrate that it is not only the pore region of the stator that moderates motility in the presence of ion‐channel blockers.