Key Words: cardiomyogenesis Ⅲ human mesenchymal stem cell Ⅲ immunologic tolerance Ⅲ myocardial infarction Ⅲ cell-based therapy A lthough embryonic stem cells 1 and induced pluripotent stem (iPS) cells 2 can be differentiated into cells of various organs, including cardiomyocytes, there are many underlining problems to overcome before clinical applications can be used, eg, tumorigenicity. 3 Autografts of iPS cells may not cause immunologic rejection; ironically, however, possible neoplasm formation would cause a serious problem because the neoplasm would not be rejected by the withdrawal of immunosuppressive agents. On the other hand, mesenchymal stem cells (MSCs) have recently been used for clinical application, and their safety and feasibility in cardiac stem cell-based therapy have been demonstrated. 4 Thus, MSCs are a more important cellular source for stem cell-based therapy from a practical point of view.The efficacy of human bone marrow-derived MSCs (BMMSCs) was still limited, 5 however, because of low efficiency for cardiomyogenic transdifferentiation. 6 We previously reported that non-marrow-derived mesenchymal cells had higher cardiomyogenic transdifferentiation efficiency, eg, menstrual blood-derived mesenchymal cells (MMCs), 7 umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), 8 and placental chorionic plate-derived mesenchymal cells (PCPCs). 9 These cells are thought to be used by an allograft; therefore, problems of immunologic rejection arise. However, an allograft may be superior to an autograft in several ways. Taking into account the background condition of the patient (eg, metabolic disease or age), Original received July 16, 2009; revision received April 14, 2010; accepted April 22, 2010 16 reported significant recovery of cardiac function by the rat amnion-derived cell transplantation in rat myocardial infarction (MI) model, however, they failed to show clear evidence of cardiomyogenic differentiation in vivo. Therefore, in the present study, we attempted to show: (1) the powerful cardiomyogenic transdifferentiation potential of our isolated hAMCs, and the beneficial effect of transplantation of hAMCs on cardiac function in vivo; (2) the induction of immunologic tolerance so that hAMCs can be a powerful allograftable stem cell source without either the administration of immunosuppressive agents or matching of MHC typing; (3) the mechanism of induction of tolerance; and (4) the close relationship between the cardiomyogenic transdifferentiation of mesenchymal cells and the process of immunologic tolerance. MethodsAn expanded Methods section is available in the Online Data Supplement at http://circres.ahajournals.org. Isolation and Culture of Human Amniotic Membrane-Derived Mesenchymal CellsHuman amniotic membrane was collected, with informed consent from individual patients, after delivery of a male neonate. The study was approved by the ethics committee of Keio University School of Medicine. The precise methods for culture have been described previously. 9,17 Detail is shown in...

Gibberellin A 1 (GA1), 3-epi-GAl, GA17, GA19, GA2o, and GA77 were identified by Kovats retention indices and full-scan mass spectra from gas chromatography-mass spectrometry analysis of a purified extract of mature seeds of photoblastic lettuce (Lactuca sativa L. cv. Grand Rapids). Non-13-hydroxylated GAs such as GA 4 and GA 9 were not detected even by highly sensitive radioimmunoassay. These results show that the major biosyn-

The efficacy of transplantation of default human marrowderived mesenchymal stem cells (MSCs) was modest. In this study, our challenge was to improve the efficacy of MSC transplantation in vivo by pretreatment of MSCs with pioglitazone. MSCs were cultured with or without medium containing 1 lM of pioglitazone before cardiomyogenic induction. After cardiomyogenic induction in vitro, cardiomyogenic transdifferentiation efficiency (CTE) was calculated by immunocytochemistry using anti-cardiac troponin-I antibody. For the in vivo experiments, myocardial infarction (MI) at the anterior left ventricle was made in nude rats. Two weeks after MI, MSCs pretreated with pioglitazone (p-BM; n 5 30) or without pioglitazone (BM; n 5 17) were injected, and then survived for 2 weeks. We compared left ventricular function by echocardiogram and immunohistochemistry to observe cardiomyogenic transdifferentiation in vivo. Pretreatment with pioglitazone significantly increased the CTE in vitro (1.9% 6 0.2% n 5 47 vs. 39.5% 6 4.7% n 5 13, p < .05). Transplantation of pioglitazone pretreated MSCs significantly improved change in left ventricular % fractional shortening (BM; 24.8% 6 2.1%, vs. p-BM; 5.2% 6 1.5%). Immunohistochemistry revealed significant improvement of cardiomyogenic transdifferentiation in p-BM in vivo (BM; 0% 6 0% n 5 5, vs. p-BM; 0.077% 6 0.041% n 5 5). Transplantation of pioglitazonepretreated MSCs significantly improved cardiac function and can be a promising cardiac stem cell source to expect cardiomyogenesis.

We have encountered a paternity case where exclusion of the putative father was only observed in the ABO blood group (mother, B; child, A1; putative father, O), among the many polymorphic markers tested, including DNA fingerprints and microsatellite markers. Cloning a part of the ABO gene, PCR-amplified from the trio's genomes, followed by sequencing the cloned fragments, showed that one allele of the child had a hybrid nature, comprising exon 6 of the B allele and exon 7 of the O1 allele. Based on the evidence that exon 7 is crucial for the sugar-nucleotide specificity of A1 and B transferases and that the O1 allele is only specified by the 261G deletion in exon 6 of the consensus sequence of the A1 allele, we concluded that the hybrid allele encodes a transferase with A1 specificity, resulting, presumably, from de novo recombination between the B and O1 alleles of the mother during meiosis. Screening of random populations demonstrated the occurrence of four other hybrid alleles. Sequencing of intron VI from the five hybrid alleles showed that the junctions of the hybrid alleles were located within intron VI, the intron VI-exon 7 boundaries, or exon 7. Recombinational events seem to be partly involved in the genesis of sequence diversities of the ABO gene.