A Phylogroup of the Siberian Chipmunk from Korea (Tamias sibiricus barberi) Revealed from the Mitochondrial DNA Cytochrome b Gene

In the full sequences of the mtDNA cytochrome b gene, 26 haplotypes (Tamias sibiricus barberi) from six localities of central and southern Korea were distinct from 21 haplotypes (Tamias sibiricus orientalis) from five localities of northeast China and Vladivostok, Russia. The average Tamura–Nei nucleotide distance between the subspecies (11.40%) and maximum infrasubspecific distances (3.74% and 4.72%) support the subspecies classification of T. s. barberi based on morphometric comparison. The 26 haplotypes of T. s. barberi were also distinct from 2 haplotypes of T. s. orientalis and Tamias sibiricus jacutensis from far-east Russia (average distance, 11.86%). Thus T. s. barberi constitutes a “phylogroup” (average nucleotide distance > 10%); analyses with nuclear genes of northeast Asian specimens, including North Korean ones, are necessary to clarify its taxonomic status. Furthermore, 49 haplotypes of T. sibiricus from eastern Asia differed from 19 haplotypes of another 18 Tamias spp. from America (weighted-average distance, 18.58%). T. sibiricus is, therefore, distinct enough to be recognized as a subgenus, Eutamias.     

Syndecan-2 Functions as a Docking Receptor for Pro-matrix Metalloproteinase-7 in Human Colon Cancer Cells

Although elevated syndecan-2 expression is known to be crucial for the tumorigenic activity in colon carcinoma cells, how syndecan-2 regulates colon cancer is unclear. In human colon adenocarcinoma tissue samples, we found that both mRNA and protein expression of syndecan-2 were increased, compared with the neighboring normal epithelium, suggesting that syndecan-2 plays functional roles in human colon cancer cells. Consistent with this notion, syndecan-2-overexpressing HT-29 colon adenocarcinoma cells showed enhanced migration/invasion, anchorage-independent growth, and primary tumor formation in nude mice, paralleling their morphological changes into highly tumorigenic cells. In addition, our experiments revealed that syndecan-2 enhanced both expression and secretion of matrix metalloproteinase-7 (MMP-7), directly interacted with pro-MMP-7, and potentiated the enzymatic activity of pro-MMP-7 by activating its processing into the active MMP-7. Collectively, these data strongly suggest that syndecan-2 functions as a docking receptor for pro-MMP-7 in colon cancer cells.     

Caffeic acid phenethyl ester accumulates β-catenin through GSK-3β and participates in proliferation through mTOR in C2C12 cells

AimThe aim of this study is to characterize the roles of caffeic acid phenethyl ester (CAPE) in the skeletal muscle cells.Main methodsWe performed immunoblotting assay using various phosphorylation specific antibodies.Key findingsWe found that CAPE induces rapid and transient phosphorylation of glycogen synthase kinase (GSK)-3β in a phosphoinositide 3-kinase (PI3K)-dependent manner. CAPE also decreases phosphorylation of β-catenin, ultimately leading to β-catenin accumulation. In addition, we demonstrated that CAPE activated the mammalian target of rapamycin (mTOR)-p70 S6 ribosomal kinase (S6K) and also stimulated extracellular signal-regulated kinase (ERK). The inhibition of mTOR blocked CAPE-induced ERK phosphorylation.SignificanceOur results suggest that CAPE may act through β-catenin accumulation via stimulation of GSK-3β and may also participate in cellular proliferation through the mTOR–ERK pathway.     

Differential expression of cell surface proteins in human bone marrow mesenchymal stem cells cultured with or without basic fibroblast growth factor containing medium

Mesenchymal stem cells (MSCs) are multipotent cells, which have the capability to differentiate into various mesenchymal tissues such as bone, cartilage, fat, tendon, muscle, and marrow stroma. However, they lose the capability of multi‐lineage differentiation after several passages. It is known that basic fibroblast growth factor (bFGF) increases growth rate, differentiation potential, and morphological changes of MSCs in vitro. In this report, we have used 2‐DE coupled to MS to identify differentially expressed proteins at the cell membrane level in MSCs growing in bFGF containing medium. The cell surface proteins isolated by the biotin–avidin affinity column were separated by 2‐DE in triplicate experiments. A total of 15 differentially expressed proteins were identified by quadrupole‐time of flight tandem MS. Nine of the proteins were upregulated and six proteins were downregulated in the MSCs cultured with bFGF containing medium. The expression level of three actin‐related proteins, F‐actin‐capping protein subunit alpha‐1, actin‐related protein 2/3 complex subunit 2, and myosin regulatory light chain 2, was confirmed by Western blot analysis. The results indicate that the expression levels of F‐actin‐capping protein subunit alpha‐1, actin‐related protein 2/3 complex subunit 2, and myosin regulatory light chain 2 are important in bFGF‐induced morphological change of MSCs.     

Calpain inhibitory flavonoids isolated from Orostachys japonicus

The n-butanol (n-BuOH) fraction of Orostachys japonicus A. Berger (Crassulaceae) significantly inhibited calpain activity. Through the activity-guided isolation from the n-BuOH fraction, herbacetin 8-O-alpha-D-ribopyranoside (1), kaempferol (2), quercetin (3), afzelin (4), astragalin (5), isoquercetin (6) and quercitrin (7) were obtained. Their structures were determined by spectroscopic techniques. Among them, compound 3 and 5 had significant calpain inhibitory activities.