The Therapeutic Effects of Adipose-Derived Stem Cells and Recombinant Peptide Pieces on Mouse Model of DSS Colitis.

Cell therapies using adipose-derived stem cells (ADSCs) have been used to treat inflammatory bowel disease (IBD) in human and dog. We previously reported the CellSaic technique, which uses a recombinant scaffold to enhance the efficacy of cell therapy. To examine whether this technique can be applied to cell therapy for colitis, we evaluated the efficacy of CellSaic in colitis mouse models. Colitis mouse models were developed by administering dextran sulfate sodium (DSS) to C57BL/6 mice for 7 days. Then CellSaic comprising human/canine ADSCs (1.2 × 106 cells) or human/canine ADSCs only (1.2 × 106 cells) were administered to the mice. The body weights were measured, and the colon length measurements and histological evaluations were conducted at 7 days after administration. After in vitro culture of human ADSC (hADSC) CellSaic and hADSC spheroids in medium containing TNFα, the levels of the anti-inflammatory protein TSG-6 in each supernatant were measured. Furthermore, we conducted tumorigenicity and general toxicity tests of canine ADSC (cADSC) CellSaic in NOG mice for 8 weeks. In the colitis mouse models, the ADSC CellSaic group presented recovery of body weight and colon length compared with the ADSC-only group. Histological analysis showed that ADSC CellSaic decreased the number of inflammatory cells and repaired ulceration. In vitro, hADSC CellSaic secreted 3.1-fold more TSG-6 than the hADSCs. In addition, tumorigenicity and general toxicity of cADSC CellSaic were not observed. This study suggests that human and canine ADSC CellSaic has a therapeutic effect of colitis in human and dogs.

Introduction to a new cell transplantation platform via recombinant peptide petaloid pieces and its application to islet transplantation with mesenchymal stem cells.

Cell death cluster in transplanted cells remains a critical obstacle for regeneration strategies. This study describes a novel platform for cell transplantation (CellSaic) consisting of human mesenchymal stem cells (hMSCs) and petaloid pieces of recombinant peptide (RCP), which can prevent cell death by arranging the cells in a mosaic. When hMSC CellSaics were subcutaneously implanted into NOD/SCID mice, hMSC CellSaics prevented cell death and accelerated angiogenesis in the graft, compared to the findings obtained on solely implanting cell spheroids. Additionally, we examined the application of CellSaic for subcutaneous cotransplantation of 200 rat islets with 2 × 10(5) hMSCs into diabetic mice. As the results of blood glucose levels at 1 m, the islet-only group was 398 ± 30 mg/dl and the islets with hMSCs group were 180 ± 65 mg/dl. On the other hand, the islets with hMSCs CellSaic group showed 129 ± 15 mg/dl and significantly improved glucose tolerance (P < 0.05). Additionally, we showed that the surface texture of the RCP petaloid pieces played an important role in graft survival and angiogenesis. It is anticipated that CellSaic will be used as a new platform for cell transplantation and tissue regeneration.

Identification of mutation points in Cupriavidus necator NCIMB 11599 and genetic reconstitution of glucose-utilization ability in wild strain H16 for polyhydroxyalkanoate production.

Although the facultative chemolithoautotrophic Cupriavidus necator (formerly Ralstonia eutropha) wild strain H16 is potentially useful as a host for metabolic engineering aimed at polyhydroxyalkanoate production, this organism is deficient in assimilating glucose, a major sugar in non-edible cellulosic resources. Growth properties of C. necator H16 harboring heterologous glf (encoding glucose-facilitated diffusion transporter) and glk (encoding glucokinase) from Zymomonas mobilis strongly suggested that the lack of glucose-utilization ability of C. necator H16 was caused by deficiency of both glucose-uptake and phosphorylation abilities. Next examination focused on previously unknown mutation points in a glucose-utilizing mutant of C. necator NCIMB 11599. Direct sequencing of a region of genes for putative N-acetylglucosamine-specific phosphoenolpyruvate-dependent phosphotransferase system and its upstream region identified a missense mutation in nagE corresponding to Gly265Arg in the EIIC-EIIB component, and a nonsense mutation in nagR encoding a putative GntR-type transcriptional regulator. Further analyses demonstrated that the glucose-utilization ability of C. necator NCIMB 11599 is attributed to extended sugar specificity of the mutated NagE and derepression of nagFE expression by inactivation of NagR. The mutation in nagE and disruption of nagR were then introduced onto chromosome 1 of wild strain H16 by homologous recombination. The resulting engineered strain C. necator nagE_G265R∆nagR exhibited comparable growth and poly(3-hydroxybutyrate) accumulation on glucose to those of the wild strain on fructose, demonstrating successful reconstitution of functional glucose-uptake and phosphorylation system. This recombinant strain is expected to be useful in further engineering for efficient production of PHAs from inexpensive biomass resources.