String Junction from Non-Commutative Super Yang-Mills Theory

We construct a 1/4 BPS soliton solution in N=4 non-commutative super Yang-Mills theory to the first order in the non-commutativity parameter \theta_{ij}. We then solve the non-commutative eigenvalue equations for the scalar fields. The Callan-Maldacena interpretation of the eigenvalues precisely reproduces the expected string junction picture: the string junction is tilted against the D3-branes with angle \theta_{ij}.Comment: 19 pages, 6 figures, LaTeX, v3: minor change

Brane Configuration from Monopole Solution in Non-Commutative Super Yang-Mills Theory

We study the structure of the monopole configuration in U(2) non-commutative super Yang-Mills theory. Our analysis consists of two steps: solving the BPS equation and then the eigenvalue equation in the non-commutative space. Calculation to the first non-trivial order in the non-commutativity parameter theta shows that the monopole exhibits a certain non-locality. This structure is precisely the one expected from the recent predictions by the brane-configuration technique.Comment: 12 pages, LaTeX, 2 eps figures, v2: gauge invariance problem clarified, v3: final version to be published in JHE

Conformal Symmetry in Matrix Model beyond the Eikonal Approximation

Recently, it was shown by Jevicki, Kazama and Yoneya (JKY) that the Super-Yang-Mills theories (SYM) in $D\leq 4$ can reproduce the conformal symmetry of the near-horizon geometry of the D-brane solutions. However, the eikonal approximation they used is not sufficient for analyzing the conformal symmetry in SYM. We carry out the 1-loop calculation beyond the eikonal approximation for D=1 SYM (i.e., Matrix model) to confirm the claim of JKY.Comment: 12 pages, LaTeX, no figures, minor correction

Boundary and Midpoint Behaviors of Lump Solutions in Vacuum String Field Theory

We discuss various issues concerning the behaviors near the boundary (\sigma=0,\pi) and the midpoint (\sigma=\pi/2) of the open string coordinate X(\sigma) and its conjugate momentum P(\sigma)=-i\delta/\delta X(\sigma) acting on the matter projectors of vacuum string field theory. Our original interest is in the dynamical change of the boundary conditions of the open string coordinate from the Neumann one in the translationally invariant backgrounds to the Dirichlet one in the D-brane backgrounds. We find that the Dirichlet boundary condition is realized on a lump solution only partially and only when its parameter takes a special value. On the other hand, the string midpoint has a mysterious property: it obeys the Neumann (Dirichlet) condition in the translationally invariant (lump) background.Comment: 23 pages, no figures, LaTeX2e, a reference adde

BNIP3 Plays Crucial Roles in the Differentiation and Maintenance of Epidermal Keratinocytes

Transcriptome analysis of the epidermis of Hes1−/− mouse revealed the direct relationship between Hes1 (hairy and enhancer of split-1) and BNIP3 (BCL2 and adenovirus E1B 19-kDa-interacting protein 3), a potent inducer of autophagy. Keratinocyte differentiation is going along with activation of lysosomal enzymes and organelle clearance, expecting the contribution of autophagy in this process. We found that BNIP3 was expressed in the suprabasal layer of the epidermis, where autophagosome formation is normally observed. Forced expression of BNIP3 in human primary epidermal keratinocytes (HPEKs) resulted in autophagy induction and keratinocyte differentiation, whereas knockdown of BNIP3 had the opposite effect. Intriguingly, addition of an autophagy inhibitor significantly suppressed the BNIP3-stimulated differentiation of keratinocytes, suggesting that BNIP3 plays a crucial role in keratinocyte differentiation by inducing autophagy. Furthermore, the number of dead cells increased in the human epidermal equivalent of BNIP3 knockdown keratinocytes, which suggests that BNIP3 is important for maintenance of skin epidermis. Interestingly, although UVB irradiation stimulated BNIP3 expression and cleavage of caspase3, suppression of UVB-induced BNIP3 expression led to further increase in cleaved caspase3 levels. This suggests that BNIP3 has a protective effect against UVB-induced apoptosis in keratinocytes. Overall, our data provide valuable insights into the role of BNIP3 in the differentiation and maintenance of epidermal keratinocytes

Differentiation of Human Adipose-Derived Mesenchymal Stromal/Stem Cells into Insulin-Producing Cells with A Single Tet-Off Lentiviral Vector System

Objective: Human adipose-derived mesenchymal stromal/stem cells (hASC) constitute an attractive source of stemcells for cell-based therapies in regenerative medicine and tissue engineering as they are easy to acquire fromlipoaspirate, expansion, and genetic modification ex vivo. The combination of Pdx-1, MafA, and NeuroD1 has beenindicated to possess the ability to reprogram various types of cells into insulin-producing cells. The aim of this study is toinvestigate whether MafA and NeuroD1 would cooperate with Pdx-1 in the differentiation of hASC into insulin-producingcells.Materials and Methods:In this experimental study, we generated polycistronic expression vectors expressing Pdx1and MafA/NeuroD1 with a reporter from a human EF-1α promoter using 2A peptides in a single tet-off lentiviral vectorsystem. Briefly, hASC were transduced with the lentiviral vectors and allowed to differentiate into insulin-producing cellsin vitro and in vivo. Thereafter, RNA expression, dithizone staining, and immunofluorescent analysis were conducted.Results: Cleaved transcriptional factors from a single tet-off lentiviral vector were functionally equivalent to their nativeproteins and strictly regulated by doxycycline (Dox). Insulin gene expression in hASC transduced with Pdx1, Pdx1/MafA, and Pdx1/NeuroD1 in differentiation medium were successfully increased by 1.89 ± 0.39, 4.81 ± 0.98, 5.51 ±0.63, respectively, compared to venus-transduced, control hASC. These cells could form dithizone-positive cell clustersin vitro and were found to express insulin in vivo.Conclusion: Using our single tet-off lentiviral vector system, Pdx-1 and MafA/NeuroD1 could be simultaneouslyexpressed in the absence of Dox. Further, this system allowed the differentiation of hASC into insulin-producing cells