Valproic Acid-Induced Anxiety and Depression Behaviors are Ameliorated in p39 Cdk5 Activator-Deficient Mice

Neurochemical Research - Valproic acid (VPA) is a drug used for the treatment of epilepsy, seizures, migraines, and bipolar disorders. Cyclin-dependent kinase 5 (Cdk5) is a Ser/Thr kinase activated...     

Morphogenetic roles of perlecan in the tooth enamel organ: an analysis of overexpression using transgenic mice

Perlecan, a heparan sulfate proteoglycan, is enriched in the intercellular space of the enamel organ. To understand the role of perlecan in tooth morphogenesis, we used a keratin 5 promoter to generate transgenic (Tg) mice that over-express perlecan in epithelial cells, and examined their tooth germs at tissue and cellular levels. Immunohistochemistry showed that perlecan was more strongly expressed in the enamel organ cells of Tg mice than in wild-type mice. Histopathology showed wider intercellular spaces in the stellate reticulum of the Tg molars and loss of cellular polarity in the enamel organ, especially in its cervical region. Hertwig's epithelial root sheath (HERS) cells in Tg mice were irregularly aligned due to excessive deposits of perlecan along the inner, as well as on the outer sides of the HERS. Tg molars had dull-ended crowns and outward-curved tooth roots and their enamel was poorly crystallized, resulting in pronounced attrition of molar cusp areas. In Tg mice, expression of integrin β1 mRNA was remarkably higher at E18, while expression of bFGF, TGF-β1, DSPP and Shh was more elevated at P1. The overexpression of perlecan in the enamel organ resulted in irregular morphology of teeth, suggesting that the expression of perlecan regulates growth factor signaling in a stage-dependent manner during each step of the interaction between ameloblast-lineage cells and mesenchymal cells.     

The utility of indels in population genetics: the Tpi intron for host race genealogy of Acrocercops transecta (Insecta: Lepidoptera)

We investigated the utility of indel data for genealogical and population genetic analyses using the Tpi intron of the leaf mining moth Acrocercops transecta (Insecta: Lepidoptera). Genealogical analyses revealed that indel data were less homoplasious than DNA sequence data and that indel data contained a sufficient signal to provide a high resolution tree that was highly congruent with the tree estimated from DNA sequences. Although some conflicts were identified in the distributions of multi-residue indels, such conflicts were especially useful for the unambiguous detection of recombinations. For the first time, we adopted a Bayesian clustering method for indel characters to infer genetic structure of the moth. We concluded that indel characters have the potential to be a powerful tool in the analysis of population genetics and population structure as well as in the detection of gene flow.     

The first crystal structure of hyperthermostable NAD-dependent glutamate dehydrogenase from Pyrobaculum islandicum

The extremely thermostable NAD-dependent glutamate dehydrogenase (NAD-GluDH) from Pyrobaculum islandicum, a member of the Crenarchaeota, was crystallized, and its 3D structure has been determined by X-ray diffraction methods. The homohexameric structure of Pb. islandicum glutamate dehydrogenase (Pis-GluDH) was solved and refined at a resolution of 2.9A with a crystallographic R-factor of 19.9% (Rfree 26.0%). The structure indicates that each subunit consists of two domains separated by a deep cleft containing an active site. The secondary structural elements and catalytically important residues of the enzyme were highly conserved among the NAD(P)-dependent GluDHs from other sources. A structural comparison of Pis-GluDH with other NAD(P)-dependent GluDHs suggests that a significant difference in the alpha8-loop-alpha9 region of this enzyme is associated with its coenzyme specificity. From the analysis of the 3D structure, hydrophobic interactions between intersubunits were found to be important features for the enzyme oligomerization. It has been reported that Pis-GluDH is highly thermostable, like the GluDH of the hyperthermophilic archaeum Pyrococcus furiosus, and the increase in the intersubunit ion pair networks is responsible for the extreme thermostability of the Pc. furiosus enzyme. However, the number of intersubunit ion pairs in the Pis-GluDH molecules is much smaller than those of the Pc. furiosus GluDH. The number of hydrophobic interactions at the intersubunit interfaces were increased and responsible for the extremely high thermostability. This indicates that the major molecular strategy for high thermostability of the GluDHs may be different for each hyperthermophile.     

Control of body size by SMA-5, a homolog of MAP kinase BMK1/ERK5, in C. elegans

We have analyzed the sma-5(n678) mutant in C. elegans to elucidate mechanisms controlling body size. The sma-5 mutant is very small, grows slowly and its intestinal granules look abnormal. We found a 15 kb deletion in the mutant that includes a 226 bp deletion of the 3' end of the W06B3.2-coding sequence. Based on this result, rescue experiments, RNAi experiments and a newly isolated deletion mutant of W06B3.2, we conclude that W06B3.2 is the sma-5 gene. The sma-5 mutant has much smaller intestine, body wall muscles and hypodermis than those of the wild type. However, the number of intestinal cells or body wall muscle cells is not changed, indicating that the sma-5 mutant has much smaller cells. In relation to the smaller cell size, the amount of total protein is drastically decreased; however, the DNA content of the intestinal nuclei is unchanged in the sma-5 mutant. The sma-5 gene is expressed in intestine, excretory cell and hypodermis, and encodes homologs of a mammalian MAP kinase BMK1/ERK5/MAPK7, which was reported to control cell cycle and cell proliferation. Expression of the sma-5 gene in hypodermis is important for body size control, and it can function both organ-autonomously and non-autonomously. We propose that the sma-5 gene functions in a MAP kinase pathway to regulate body size mainly through control of cell growth.     

Design, synthesis, and biological activity of non-basic compounds as factor Xa inhibitors: SAR study of S1 and aryl binding sites

Compound 7 was identified as the active metabolite of 6 by HPLC and mass spectral analysis. Modification of lead compound 7 by transformation of its N-oxide 6-6 biaryl ring system and fused aromatics produced a series of non-basic fXa inhibitors with excellent potency in anti-fXa and anticoagulant assays. The optimized compounds 73b and 75b showed sub to one digit micromolar anticoagulant activity (PTCT2). Particularly, anti-fXa activity was detected in plasma of rats orally administered with 1mg/kg of compound 75b.