Rheb (Ras Homologue Enriched in Brain)-dependent Mammalian Target of Rapamycin Complex 1 (mTORC1) Activation Becomes Indispensable for Cardiac Hypertrophic Growth after Early Postnatal Period

Cardiomyocytes proliferate during fetal life but lose their ability to proliferate soon after birth and further increases in cardiac mass are achieved through an increase in cell size or hypertrophy. Mammalian target of rapamycin complex 1 (mTORC1) is critical for cell growth and proliferation. Rheb (Ras homologue enriched in brain) is one of the most important upstream regulators of mTORC1. Here, we attempted to clarify the role of Rheb in the heart using cardiac-specific Rheb-deficient mice (Rheb^−/−). Rheb^−/− mice died from postnatal day 8 to 10. The heart-to-body weight ratio, an index of cardiomyocyte hypertrophy, in Rheb^−/− was lower than that in the control (Rheb^+/+) at postnatal day 8. The cell surface area of cardiomyocytes isolated from the mouse hearts increased from postnatal days 5 to 8 in Rheb^+/+ mice but not in Rheb^−/− mice. Ultrastructural analysis indicated that sarcomere maturation was impaired in Rheb^−/− hearts during the neonatal period. Rheb^−/− hearts exhibited no difference in the phosphorylation level of S6 or 4E-BP1, downstream of mTORC1 at postnatal day 3 but showed attenuation at postnatal day 5 or 8 compared with the control. Polysome analysis revealed that the mRNA translation activity decreased in Rheb^−/− hearts at postnatal day 8. Furthermore, ablation of eukaryotic initiation factor 4E-binding protein 1 in Rheb^−/− mice improved mRNA translation, cardiac hypertrophic growth, sarcomere maturation, and survival. Thus, Rheb-dependent mTORC1 activation becomes essential for cardiomyocyte hypertrophic growth after early postnatal period.     

Generation of robust vascular networks from cardiovascular blast populations derived from human induced pluripotent stem cells in vivo and ex vivo organ culture system

Vascular network formation is a key therapeutic event in regenerative medicine because it is essential for mitigating or ameliorating ischemic conditions implicated in various diseases and repair of tissues and organs. In this study, we induced human induced pluripotent stem cells (hiPSCs) to differentiate into heterogeneous cell populations which have abilities to form vascular vessel-like structures by recapitulating the embryonic process of vasculogenesis in vitro. These cell populations, named cardiovascular blast populations (CBPs) in this report, primarily consisted of CD31⁺ and CD90⁺ cells.     

Tail-extension following the termination codon is critical for release of the nascent chain from membrane-bound ribosomes in a reticulocyte lysate cell-free system

Nascent chain release from membrane-bound ribosomes by the termination codon was investigated using a cell-free translation system from rabbit supplemented with rough microsomal membrane vesicles. Chain release was extremely slow when mRNA ended with only the termination codon. Tail extension after the termination codon enhanced the release of the nascent chain. Release reached plateau levels with tail extension of 10 bases. This requirement was observed with all termination codons: TAA, TGA and TAG. Rapid release was also achieved by puromycin even in the absence of the extension. Efficient translation termination cannot be achieved in the presence of only a termination codon on the mRNA. Tail extension might be required for correct positioning of the termination codon in the ribosome and/or efficient recognition by release factors.     

A new Early Cretaceous eutherian mammal from the Sasayama Group,Hyogo, Japan

We here describe a new Early Cretaceous (early Albian) eutherian mammal, Sasayamamylos kawaii gen. et sp. nov., from the ‘Lower Formation’ of the Sasayama Group, Hyogo Prefecture, Japan. Sasayamamylos kawaii is characterized by a robust dentary, a distinct angle on the ventral margin of the dentary at the posterior end of the mandibular symphysis, a lower dental formula of 3–4 : 1 : 4 : 3, a robust lower canine, a non-molariform lower ultimate premolar, and a secondarily reduced entoconid on the molars. To date, S. kawaii is the earliest known eutherian mammal possessing only four premolars, which demonstrates that the reduction in the premolar count in eutherians started in the late Early Cretaceous. The occurrence of S. kawaii implies that the relatively rapid diversification of eutherians in the mid-Cretaceous had already started by the early Albian.     

Aroma Components of Baelfruit (Aegle marmelos CORREA)

The attractive and characteristically sweet aroma components of baelfruit—a tropical fruit— were investigated. The aroma concentrates possessing the sweet floral and somewhat terpene-like aroma were obtained from both the pulp and peel of fresh baelfruits by means of lyophilization and ether extraction, being analyzed mainly by GC-MS, A total of 39 components were identified. Among these components, terpene alcohols and β-βonone were considered to contribute to the aroma of baelfruit. At optimum ripeness, the fruit with excellent flavor contained a large quantity of an isomeric compound of 3,7-dimethyl-1,5,7-octatrien-3-ol. This compound couldn’t be found in unripe fruit, and seems to be ?mportant in making the baelfruit flavor attractive.     

Flavor Constituents of Pouchong Tea and a Comparison of the Aroma Pattern with Jasmine Tea

The aroma constituents of the highest quality pouchong tea were characterized by GC–MS. Forty-eight components, including five newly identified compounds were characterized. GC peak area percentages of the main components in pouchong tea were compared with those of jasmine tea to differentiate compounds contributing to the aroma characteristics of pouchong tea with superior floral elegant flavor. Nerolidol, jasmine lactone, methyl jasmonate, indole, benzyl cyanide and linalool oxides were found in much higher concentration in pouchong tea than in jasmine tea. These compounds seemed to contribute to the aroma characteristics of the highest quality pouchong tea.     

Effect of Additional Protein or Methionine and Threonine on Tyrosine Catabolism in Rats Fed Diets High in Tyrosine

The supplementation of additional protein or methionine and threonine to a high tyrosinc-low protein diet has previously been shown to prevent the tyrosine toxicity. To elucidate the mechanism, studies were performed on the effect of these supplements on the capacity to oxidize excessive tyrosine. Male weanling rats were ad libitum fed a 10% casein diet containing 5% tyrosine with and without extra casein or methionine plus threonine for 7 days, then animals were injected intraperitoneally with l-tyrosine-U-¹⁴C and the oxidation rate to ¹⁴CO₂ determined in vivo at an interval of several hours throughout a 24-hour period. The addition of extra casein or methionine and threonine to the high tyrosine diet enhanced the ability of tyrosine oxidation, and decreased the radioactivities of the TCA-soluble fractions in plasma, liver and muscle. A high level of free tyrosine in blood and tissues was also lowered by the addition of these supplements. The diurnal chenges in free tyrosine concentration of various tissues were observed. The data suggest that the beneficial effect of extra casein or methionine and threonine supplementation on tyrosine toxicity is due to an increased rate of tyrosine catabolism which results in lower tyrosine concentrations in body fluids which overcomes tyrosine toxicity.     

Some Physicochemical Properties of Invertase of Candida utilis

This study examined the microbial transformation of carbazole (CZ) by an isolated bacterium that can use CZ as a sole carbon and nitrogen source. The strain identified as Pseudomonas stutzeri produced a large amount of anthranilic acid (AA) from CZ in the medium containing a nonionic surfactant. In dialysis culture using ion-exchange resin, 7.9 g/liter (58mm) of AA was accumulated from 15g/liter (90mm) of CZ and the molar yield of AA reached about 64%.     

Identification of GA3 in Neurospora crassa and Its Changes during Conidial Germination and Mycelial Growth

GA₃ was identified as a major GA in Neurospora crassa by gas chromatography/selected ion monitoring (GC/SIM) and its content was measured at various stages (0~96 hr after inoculation) of conidial germination and mycelial growth. The GA₃ content in the fungus was 190ng/g dry weight at the initial stage and then decreased rapidly; that per liter culture decreased soon after the inoculation, and then increased to 17.6 ng 96 hr after inoculation. The GA₃ concentration in the culture medium was around 10^?11 m throughout the 96-hr incubation. The physiological role of endogenous GA in Neurospora crassa is also discussed.