Serotonin transporter polymorphisms affect human blood glucose control

We measured the effect of nutritional intervention on clinical data, including fasting blood glucose (FBG), and their association with polymorphisms of the serotonin transporter-linked polymorphic region (5-HTTLPR) which might affect adherence. Enrolled in the intervention program were 264 Japanese women not on medication for diabetes, hypercholesterolemia or hypertension. The 5-HTTLPR allele (S and L) frequencies among the subjects differed markedly from those of Caucasians: SS (n = 183), LS (n = 69), and LL (n = 12). The decrease in FBG (DeltaFBG) from the beginning to the end of the program (11 weeks; short-term study), and DeltaFBG from the beginning to a follow-up check performed between 2002 and 2004 (average of 23 years later; long-term study) was calculated. The SS homozygotes of 5-HTTLPR showed larger DeltaFBG (P = 0.01 and P < 0.0001 in the short- and long-term studies, respectively) than DeltaFBG with other genotypes.     

Conformational change of bovine serum albumin by heat treatment

The thermal denaturation of bovine serum albumin (BSA) was studied at pH 2.8 and 7.0 in the range of 2–65°C. The relative proportions of -helix, -structure, and disordered structure in the protein conformation were determined as a function of temperature, by the curve-fitting method of circular dichroism spectra. With the rise of temperature at pH 7.0, the proportion of -helix decreased above 30°C and those of -structure and disordered structure increased in the same temperature range. The structural change was reversible in the temperature range below 45°C. However, the structural change was partially reversible upon cooling to room temperature subsequent to heating at 65°C. On the other hand, the structural change of BSA at pH 2.3 was completely reversible in the temperature range of 2–65°C, probably because the interactions between domains and between subdomains might disappear due to the acid expansion. The secondary structure of disulfide bridges-cleaved BSA remained unchanged during the heat treatment up to 65°C at pH 2.8 and 7.0.     

The retinol-retinoic acid metabolic pathway is impaired in the lumbar spine of a rat model of congenital kyphoscoliosis

Although congenital scoliosis is defined as a genetic disease characterized by a congenital and abnormal curvature of the spinal vertebrae, our knowledge of the genetic underpinnings of the disease is insufficient. We herein show that the downregulation of the retinol-retinoic acid metabolism pathway is involved in the pathogenesis of congenital scoliosis. By analyzing DNA microarray data, we found that the expression levels of genes associated with the retinol metabolism pathway were decreased in the lumbar spine of Ishibashi rats (IS), a rat model of congenital kyphoscoliosis. The expression of Adh1 and Aldh1a2 (alcohol dehydrogenase), two enzymes that convert retinol to retinoic acid in this pathway, were decreased at both the gene and protein levels. Rarα, a receptor of retinoic acid and bone morphogenetic protein 2, which play a central role in bone formation and are located downstream of this pathway, were also downregulated. Interestingly, the serum retinol levels of IS rats were higher than those of wild-type control rats. These results indicate that the adequate conversion from retinol to retinoic acid is extremely important in the regulation of normal bone formation and it may also be a key factor for understanding the pathogenesis of congenital scoliosis.     

Stanniocalcin 1 acts as a paracrine regulator of growth plate chondrogenesis

During embryogenesis, the expression of mammalian stanniocalcin (STC1) in the appendicular skeleton suggests its involvement in the regulation of longitudinal bone growth. Such a role is further supported by the presence of dwarfism in mice overexpressing STC1. Yet, the STC 1 inhibitory effect on growth may be related to both postnatal metabolic abnormalities and prenatal defective bone formation. In our study, we used an organ culture system to evaluate the effects of STC on growth plate chondrogenesis, which is the primary determinant of longitudinal bone growth. Fetal rat metatarsal bones were cultured in the presence of recombinant human STC (rhSTC). After 3 days, rhSTC suppressed metatarsal growth, growth plate chondrocyte proliferation and hypertrophy/differentiation, and extracellular matrix synthesis. In addition, rhSTC increased the number of apoptotic chondrocytes in the growth plate. In cultured chondrocytes, rhSTC increased phosphate uptake, reduced chondrocyte proliferation and matrix synthesis, and induced apoptosis. All these effects were reversed by culturing chondrocytes with rhSTC and phosphonoformic acid, an inhibitor of phosphate transport. The rhSTC-mediated inhibition of metatarsal growth and growth plate chondrocyte proliferation and hypertrophy/differentiation was abolished by culturing metatarsals with rhSTC and phosphonoformic acid. Taken together, our findings indicate that STC1 inhibits longitudinal bone growth directly at the growth plate. Such growth inhibition, likely mediated by an increased chondrocyte phosphate uptake, results from suppressed chondrocyte proliferation, hypertrophy/differentiation, and matrix synthesis and by increased apoptosis. Last, the expression of both STC1 and its binding site in the growth plate would support an autocrine/paracrine role for this growth factor in the regulation of growth plate chondrogenesis.     

Structural basis for budding by the ESCRT-III factor CHMP3

The vacuolar protein sorting machinery regulates multivesicular body biogenesis and is selectively recruited by enveloped viruses to support budding. Here we report the crystal structure of the human ESCRT-III protein CHMP3 at 2.8 A resolution. The core structure of CHMP3 folds into a flat helical arrangement that assembles into a lattice, mainly via two different dimerization modes, and unilaterally exposes a highly basic surface. The C terminus, the target for Vps4-induced ESCRT disassembly, extends from the opposite side of the membrane targeting region. Mutations within the basic and dimerization regions hinder bilayer interaction in vivo and reverse the dominant-negative effect of a truncated CHMP3 fusion protein on HIV-1 budding. Thus, the final steps in the budding process may include CHMP protein polymerization and lattice formation on membranes by employing different bilayer-recognizing surfaces, a function shared by all CHMP family members.     

Functional expression of thiocyanate hydrolase is promoted by its activator protein, P15K

Thiocyanate hydrolase (SCNase) is a cobalt-containing enzyme with a post-translationally modified cysteine ligand, gammaCys131-SO(2)H. When the SCNase alpha, beta and gamma subunits were expressed in Escherichia coli, the subunits assembled to form a hetero-dodecamer, (alphabetagamma)(4), like native SCNase but exhibited no catalytic activity. Metal analysis indicated that SCNase was expressed as an apo-form irrespective of the presence of cobalt in the medium. On the contrary, SCNase co-expressed with P15K, encoded just downstream of SCNase genes, in cobalt-enriched medium under the optimized condition (SCNase((+P15K))) possessed 0.86 Co atom/alphabetagamma trimer and exhibited 78% of the activity of native SCNase. SCNase((+P15K)) showed a UV-Vis absorption peak characteristic of the SCNase cobalt center. About 70% of SCNase((+P15K)) had the gammaCys131-SO(2)H modification. These results indicate that SCNase((+P15K)) is the active holo-SCNase. P15K is likely to promote the functional expression of SCNase probably by assisting the incorporation of cobalt ion.     

Effects of the culture density of mouse zygotes on the development in vitro and in vivo

Different numbers of CD-1 mouse zygotes(1, 5, 10, 20, 40 and 60) were cultured in 10 mul M16 medium, in M16 medium+EDTA, in M16 dedium+SOD+thioredoxin, and in CZB medium, respectively. When the zygotes, regardless of the number, were cultured with M16, no blastocysts could be obtained. The suitable ratio of embryos to 1 mul of M16 medium+EDTA or M16 medium+SOD+thioredoxin was 1:1 or 2:1. Medium volume from 1 to 10 mul did not affect blastocyst development when the embryo density was 1:1. However, blastocysts obtained from zygotes cultured singly had fewer cell numbers and showed inferior development to live fetuses after transfer to recipients. When CZB medium was used, suitable embryo density was not clear. The ratio of embryos to volume of culture medium was shown to be an important factor for in vitro culture of mouse zygotes.