Synthesis of a double-stranded spiroborate helicate bearing stilbene units and its photoresponsive behaviour

HPC resources of CINES and of IDRIS under the allocations 2013-[x2013080649] made by GENCI (Grand Equipement National de Calcul Intensif)International audienceA novel spiroborate-based double-stranded helicate bearing photoresponsive cis-stilbene units in the middle (cis-3) was successfully synthesised from the corresponding cis-stilbene-bound tetraphenol strand in the presence of NaBH4, whereas the tetraphenol strands with a trans-stilbene or trans-azobenzene unit did not form such a double-stranded helicate. The 1H NMR and NOESY experiments revealed that cis-3 adopted contracted (cis-3C) and extended (cis-3E) forms under equilibrium in CD3CN at 25 °C. The contracted cis-3C that accommodated a Na+ ion in the center showed an almost reversible extension and contraction motion by removal and addition of a Na+ ion. The cis-to-trans photoisomerisation of the extended cis-3E with UV light (295 nm) further induced an extension of the helicate, producing a mixture of cis,trans-3E and trans-3E helicates at the photostationary state. However, trans-to-cis photoisomerisation of the trans-mixtures using UV light (360 nm) was irreversible in this system and produced the photooxidated aldehyde species (trans-4), resulting from the photo-cleavage of the trans-stilbene moieties of the trans-3E

Differentiation of human embryonic stem cells and human induced pluripotent stem cells into steroid-producing cells.

Although there have been reports of the differentiation of mesenchymal stem cells and mouse embryonic stem (ES) cells into steroid-producing cells, the differentiation of human ES/induced pluripotent stem (iPS) cells into steroid-producing cells has not been reported. The purpose of our present study was to establish a method for inducing differentiation of human ES/iPS cells into steroid-producing cells. The first approach we tried was embryoid body formation and further culture on adherent plates. The resultant differentiated cells expressed mRNA encoding the steroidogenic enzymes steroidogenic acute regulatory protein, 3β-hydroxysteroid dehydrogenase, cytochrome P450-containing enzyme (CYP)-11A1, CYP17A1, and CYP19, and secreted progesterone was detected in the cell medium. However, expression of human chorionic gonadotropin was also detected, suggesting the differentiated cells were trophoblast like. We next tried a multistep approach. As a first step, human ES/iPS cells were induced to differentiate into the mesodermal lineage. After 7 d of differentiation induced by 6-bromoindirubin-3'-oxime (a glycogen synthase kinase-3β inhibitor), the human ES/iPS cells had differentiated into fetal liver kinase-1- and platelet derived growth factor receptor-α-expressing mesodermal lineage cells. As a second step, plasmid DNA encoding steroidogenic factor-1, a master regulator of steroidogenesis, was introduced into these mesodermal cells. The forced expression of steroidogenic factor-1 and subsequent addition of 8-bromoadenosine 3',5'-cyclic monophosphate induced the mesodermal cells to differentiate into the steroidogenic cell lineage, and expression of CYP21A2 and CYP11B1, in addition to steroidogenic acute regulatory protein, 3β-hydroxysteroid dehydrogenase, CYP11A1, and CYP17A1, was detected. Moreover, secreted cortisol was detected in the medium, but human chorionic gonadotropin was not. These findings indicate that the steroid-producing cells obtained through the described multistep method are not trophoblast like; instead, they exhibit characteristics of adrenal cortical cells

Transplantation of vascular cells derived from human embryonic stem cells contributes to vascular regeneration after stroke in mice

<p>Abstract</p> <p>Background</p> <p>We previously demonstrated that vascular endothelial growth factor receptor type 2 (VEGF-R2)-positive cells induced from mouse embryonic stem (ES) cells can differentiate into both endothelial cells (ECs) and mural cells (MCs) and these vascular cells construct blood vessel structures in vitro. Recently, we have also established a method for the large-scale expansion of ECs and MCs derived from human ES cells. We examined the potential of vascular cells derived from human ES cells to contribute to vascular regeneration and to provide therapeutic benefit for the ischemic brain.</p> <p>Methods</p> <p>Phosphate buffered saline, human peripheral blood mononuclear cells (hMNCs), ECs-, MCs-, or the mixture of ECs and MCs derived from human ES cells were intra-arterially transplanted into mice after transient middle cerebral artery occlusion (MCAo).</p> <p>Results</p> <p>Transplanted ECs were successfully incorporated into host capillaries and MCs were distributed in the areas surrounding endothelial tubes. The cerebral blood flow and the vascular density in the ischemic striatum on day 28 after MCAo had significantly improved in ECs-, MCs- and ECs+MCs-transplanted mice compared to that of mice injected with saline or transplanted with hMNCs. Moreover, compared to saline-injected or hMNC-transplanted mice, significant reduction of the infarct volume and of apoptosis as well as acceleration of neurological recovery were observed on day 28 after MCAo in the cell mixture-transplanted mice.</p> <p>Conclusion</p> <p>Transplantation of ECs and MCs derived from undifferentiated human ES cells have a potential to contribute to therapeutic vascular regeneration and consequently reduction of infarct area after stroke.</p

Augmentation of Neovascularizaiton in Hindlimb Ischemia by Combined Transplantation of Human Embryonic Stem Cells-Derived Endothelial and Mural Cells

BACKGROUND: We demonstrated that mouse embryonic stem (ES) cells-derived vascular endothelial growth factor receptor-2 (VEGF-R2) positive cells could differentiate into both endothelial cells (EC) and mural cells (MC), and termed them as vascular progenitor cells (VPC). Recently, we have established a method to expand monkey and human ES cells-derived VPC with the proper differentiation stage in a large quantity. Here we investigated the therapeutic potential of human VPC-derived EC and MC for vascular regeneration. METHODS AND RESULTS: After the expansion of human VPC-derived vascular cells, we transplanted these cells to nude mice with hindlimb ischemia. The blood flow recovery and capillary density in ischemic hindlimbs were significantly improved in human VPC-derived EC-transplanted mice, compared to human peripheral and umbilical cord blood-derived endothelial progenitor cells (pEPC and uEPC) transplanted mice. The combined transplantation of human VPC-derived EC and MC synergistically improved blood flow of ischemic hindlimbs remarkably, compared to the single cell transplantations. Transplanted VPC-derived vascular cells were effectively incorporated into host circulating vessels as EC and MC to maintain long-term vascular integrity. CONCLUSIONS: Our findings suggest that the combined transplantation of human ES cells-derived EC and MC can be used as a new promising strategy for therapeutic vascular regeneration in patients with tissue ischemia

ヒトiPS細胞からの血管細胞分化誘導、単離同定に関する研究

京都大学0048新制・課程博士博士(医学)甲第15022号医博第3398号新制||医||978(附属図書館)27483京都大学大学院医学研究科内科系専攻(主査)教授 木村 剛, 教授 中辻 憲夫, 教授 開 祐司学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDA

Critical micelle concentration and partition coefficient of mixed micelles: Analysis of ternary systems based on Markov chain model and simple mixture model

Hypothesis: When two or more surfactants are mixed, the mixed system exhibits improved performance compared with a single surfactant system in solution. The Markov chain model can analyze the critical micelle concentration (CMC) of mixed micelles, yielding results similar to those of a simple mixture model, which is typically referred to as the “regular solution theory.” In this study, two hypotheses were tested: (1) the Markov chain model for ternary systems can be simplified by approximating the association constant of surfactants i and j as Kij = Kji and (2) the quasi-simple ternary mixture model, that is, an analogous simple mixture model of the Markov chain model, helps interpret the interaction parameter of the simple mixture model that can describe the partition coefficient of the binary mixed micelle. Experiments: Equations were derived for (1) the Markov chain model for ternary systems by assuming Kij = Kji and (2) the interaction parameter of the simple mixture model that can describe the partition coefficient of the binary mixed micelle. Findings: The models were compared with the experiment data, and the derived equations described the experimental data of the CMC and partition coefficient well

Temperature-Dependent Left- and Right-Twisted Conformational Changes in 1:1 Host-Guest Systems: Theoretical Modeling and Chiroptical Simulations

An efficient strategy for applying to chiral materials is to design and synthesize host molecules with left- and right-twisted conformations and to control their twisted conformations. For this, a quantitative analysis is required to describe the chiroptical inversion, chiral transfer, and chiral recognition in the host-guest systems, which is generally performed using circular dichroism (CD) and/or proton nuclear magnetic resonance (1H-NMR) spectroscopies. However, the mass-balance model that considers the left- and right-twisted conformations has not yet been established so far. In this study, we derived novel equations based on the mass-balance model for the 1:1 host-guest systems. Then, we further applied them to analyze the 1:1 host-guest systems for the achiral calixarene-based capsule molecule, achiral dimeric zinc porphyrin tweezer molecule, and chiral pillar[5]arene with the chiral and/or achiral guest molecules by using the data obtained from the CD titration, variant temperature CD (VT-CD), and 1H-NMR experiments. The thermodynamic parameters (ΔH and ΔS), equilibrium constants (K), and molar CD (Δε) in the 1:1 host-guest systems could be successfully determined by the theoretical analyses using the derived equations