*Septins, a conserved family of GTP-binding proteins with a conserved role in cytokinesis, are present in eukaryotes ranging from yeast to mammals. Septins are also highly expressed in neurons, which are post-mitotic cells. Septin6 (SEPT6) forms SEPT2/6/7 complexes in vivo. In this study, we produced a very specific SEPT6 antibody. Immunocytochemisty (ICC) of dissociated hippocampal cultures revealed that SEPT6 was highly expressed in neurons. Developmentally, the expression of SEPT6 was very low until stage 3 (axonal outgrowth). Significant expression of SEPT6 began at stage 4 (outgrowth of dendrites). At this stage, SEPT6 clusters were positioned at the branch points of developing dendrites. In maturing and mature neurons (stage 5), SEPT6 clusters were positioned at the base of filopodia and spines, and pre-synaptic boutons. Detergent extraction experiments also indicated that SEPT6 is not a post-synaptic density (PSD) protein. Throughout morphologic development of neurons, SEPT6 always formed tiny rings (external diameter, ~0.5 µm), which appear to be clusters at low magnification. When a Sept6 RNAi vector was introduced at the early developmental stage (DIV 2), a significant reduction in dendritic length and branch number was evident. Taken together, our results indicate that SEPT6 begins to be expressed at the stage of dendritic outgrowth and regulates the cytoarchitecture.

The synthesis of bio‐based monomers and polymers from renewable feedstock, such as plant biomass, is desirable because of the depletion of fossil fuel resources and the reliance of thermosetting epoxy resin on non‐renewable petrochemical monomers. Despite the excellent polymeric properties of bisphenol‐based epoxy resins, these negatively impact human health. Herein, the synthesis of self‐curable epoxy polymers from the bio‐based material isoeugenol by forming α‐hydroxyl esters is reported. The epoxides are named AB (single epoxide and ester groups) and A2B2 (double epoxide and ester groups), based on the number of active ester and epoxide groups. The materials derived from the bio‐based material, AB and A2B2, were initiated with and without the catalyst N,N′‐dimethylaminopyridine (DMAP) and curing agent diaminodiphenylmethane. Without the catalyst, AB and A2B2 self‐polymerized at 247 and 210°C, respectively. Notably, the polymerization temperatures for AB and A2B2 decreased after the addition of DMAP. The self‐cured epoxy resin without the catalyst showed the highest thermal stability and glass transition temperature (Tg = 156°C). Degradation and recovery studies suggested forward that 51% of the material could be recovered and 94% of the polymer could be degraded from the self‐cured A2B2 in 25 wt% NaOH solution.

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In this study, we investigated the effect of Rhei Rhizoma (RR; 大黃) water extract on gene expression in a hypoxia model of cultured rat hippocampal neurons. RR water extract (2.5 μg/ml) was added to the culture media on day 10 in vitro (DIV10), and a hypoxic shock (2% O2/5% CO2 , 37 o C, 3 h) was given on DIV13. After maintaining the cultures in normoxia for 24 hr, total RNA was isolated and used for microarray analysis. The MA-plot indicated that most genes were up-or downregulated within 2-fold. There were more downregulated genes (725 ea) than upregulated ones (472 ea) when larger than Global M value 0.2 (i.e., ＞15% increase) or smaller than Global M value -0.2 (i.e., ＞15% decrease) were considered. Antiapoptosis genes such as Tegt (2.4-fold), Nfkb1 (2.4-fold) Veg (1.8-fold), Ngfr (1.6-fold) were upregulated, while pro-apoptosis genes such as Bad (-64%), Cstb (-66%) were downregulated. Genes for combating environmental stress (stress response genes) such as Defb3 (2.7-fold), Cygb (2.2-fold), Ahsg (2.18-fold), Alox5 (2-fold) were upregulated. Genes for cell proliferation (cell cycle-related genes) such as Erbb2 (1.84-fold), Mapk12 gene (1.8-fold) was upregulated. Therefore, RR water extracts upregulate many pro-survival genes while downregulating many pro-death genes. It is interpreted that these genes, in combination with other regulated genes, can promote neuronal survival in a stress such as hypoxia. [40,46]. Effects of RR on lowering serum cholesterol are attributed to rhein, which are transformed from anthranoids sennoside A and B by bacterial enzymes in large intestine [55]. Rhaponticin in the rhizome of RR has extensive anti-allergic and anti-thrombotic properties [46]. RR extracts decreased serum creatinine levels in diabetic patients with neuropathy and retinopathy [18].Studies on the nervous system are relatively scarce. It has been reported that RR improves memory ability. By comparing the effects of the Compound Tong Jiang Oral Liquid with Da Huang added (TJ) and Qi Yin Oral Liquid (QY) without Da Huang on senile persons' memory ability, Tian et al. [55] discovered that TJ improves senile persons' memory ability, in addition to shortened interval and duration of defecation. However, effects of RR on the nervous system are not studied at the cellular level. Previously, our laboratory reported that RR suppresses production of reactive oxygen species (ROS) and loss of mitochondrial membrane potential (MMP) in a hypoxia model of rat hippocampal neurons in culture [34]. Here, we report results of a microarray analysis on the expression of genes in hypoxia. Materials and MethodsPreparation of water-extracts of RR Rhei Rhizoma (RR; 大黃) was selected according to the Korean Pharmacopoeia and obtained from Dongguk University Oriental Hospital (Gyeongju, Korea). Distilled water was added to the RR powder and it was agitated for 4 hr at room temperature (RT) followed by overnight at 4 o C. After centrifugation (15,000 rpm, 15 min, RT), the supernatant was filter-sterilized (pore size 0.2 μm) and stored at -20 ...

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