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Abstract: Embryonic stem cells (ESCs) and embryonal carcinoma cells (ECCs) possess the remarkable property of self-renewal and differentiation potency. They are model preparations for investigating the underlying mechanisms of “stemness”. microRNAs are recently discovered small noncoding RNAs with a broad spectrum of functions, especially in control of development. Here, we show that miR-302b indirectly regulates expression of the pluripotent stem cell marker Oct4, and it directly regulates expression of Cyclin D2 protein, a developmental regulator during gastrulation. Using loss-of function and gain-of function approaches, we demonstrate that functional miR-302b is necessary to maintain stem cell self-renewal and inhibit neuronal differentiation of human ECCs. During retinoic acid-induced neuronal differentiation, Cyclin D2 protein but not mRNA expression is strongly increased, concurrent with the down-regulation of miR-302b and Oct4. Our results suggest that miR-302b plays an important role in maintaining the pluripotency of ECCs and probably ESCs, by post-transcriptional regulation of Cyclin D2 expression. [Copyright &y& Elsevier]

Highlights: [•] 3D collagen hydrogel provides effective culture environments for umbilical cord blood (UCB) derived cells [•] Hydrogel matrix stimulates UCB-derived cells to express neurotrophic factors [•] Neurotrophic factor release affects neurite outgrowth of neural precursor cells [•] Stem cell culture with 3D matrix is effective for neural regenerative therapy [ABSTRACT FROM AUTHOR]

Abstract: Angiogenin is one of the most potent angiogenesis-inducing proteins. Angiostatin is one of the most potent angiogenesis inhibitors, and it contains the first four kringle domains of plasminogen (K1–4). Recombinant human plasminogen kringle 1–3 (rK1–3) was expressed in Escherichia coli and purified to homogeneity. The binding of t-4-aminomethylcyclohexanecarboxylic acid with the purified kringle 1–3 was determined by changes in intrinsic fluorescence. rK1–3 exhibits comparable ligand-binding properties as native human plasminogen kringle 1–3. The purified rK1–3 inhibits neovascularization in the chick embryo chorioallantoic membrane (CAM) assay. Interaction of angiogenin with rK1–3 was examined by immunological binding assay and surface plasmon resonance kinetic analysis, and the equilibrium dissociation constants for the complex, K d, are 0.89 and 0.18μM, respectively. rK1–3 inhibits angiogenin-induced angiogenesis in the chick embryo CAM in a concentration-dependent manner. These results indicate that rK1–3 directly binds to angiogenin and thus rK1–3 inhibits the angiogenic activity of angiogenin. [Copyright &y& Elsevier]

Iridovirus is a causative agent of epizootics among cultured rock bream (Oplegnathus fasciatus) in Korea. Here, we report the complete genomic sequence of rock bream iridovirus (RBIV). The genome of RBIV was 112 080 bp long and contained at least 118 putative open reading frames (ORFs), and its genome organization was similar to that of infectious spleen and kidney necrosis virus (ISKNV). Of the RBIV''s 118 ORFs, 85 ORFs showed 60–99% amino acid identity to those of ISKNV. Phylogenetic analysis of major capsid protein (MCP), DNA repair protein RAD2, and DNA polymerase type-B family indicated that RBIV is closely related to red sea bream iridovirus (RSIV), Grouper sleepy disease iridovirus (GSDIV), Dwarf gourami iridovirus (DGIV), and ISKNV. The genome sequence provides useful information concerning the evolution and divergence of iridoviruses in cultured fish. [Copyright &y& Elsevier]

Propionic acidemia (PA) is an autosomal recessive inborn error in the catabolism of methionine, isoleucine, threonine, and valine, odd-numbered chain length fatty acids and cholesterol. Clinical symptoms are very heterogeneous and present as a severe neonatal-onset or a late-onset form. It is caused by a deficiency of propionyl-CoA carboxylase (PCC, EC 6.4.1.3), a biotin-dependent enzyme that catalyzes the carboxylation of propionyl-CoA to d-methylmalonyl-CoA. PCC is a heteropolymeric enzyme composed of α- and β-subunits. A greater heterogeneity is observed in the PCCA gene, while for the PCCB gene, a limited number of mutations is responsible for the majority of the alleles characterized in both Caucasian and Oriental populations. We identified eight Korean patients with PA by organic acid analysis confirmed in five patients by the PCC enzyme assay in the lymphoblasts. Two neonatal-onset patients showed undetectable PCC activities while three cases with residual enzyme activities had relatively late manifestations. In the molecular analysis, we identified five novel mutations, Y439C, 1527del3, 1357insT, IVS12–8T → A, and 31del10, and one known mutation, T428I in PCCB gene. Alleleic frequency of T428I in Korean patients with PA was 56.3% in this study. Two neonatal-onset patients with null enzyme activities were homozygotes with 1527del3 and T428I, respectively. This finding implies that T428I and 1527del3 mutation could be responsible for their severe clinical courses and null enzyme activities. The mRNA of PCCB gene in T428I and 1527del3 homozygotes were normal but in Western blot analysis, the βPCC-subunit was only absent in 1527del3 homozygote patient suggesting different molecular pathology. [Copyright &y& Elsevier]