Contribution of rat embryonic stem cells to xenogeneic chimeras in blastocyst or 8‐cell embryo injection and aggregation

The ultimate goal of regenerative medicine is the transplantation of a target organ generated by the patient's own cells. Recently, a method of organ generation using pluripotent stem cells (PSCs) and blastocyst complementation was reported. This approach is based on chimeric animal generation using an early embryo and PSCs, and the contribution of PSCs to the target organ is key to the method's success. However, the contribution rate of PSCs in target organs generated by different chimeric animal generation methods remains unknown. In this study, we used 8‐cell embryo aggregation, 8‐cell embryo injection, and blastocyst injection to generate interspecies chimeric mice using rat embryonic stem (ES) cells and then investigated the differences in the contribution rate of the rat ES cells. The rate of chimeric mouse generation was the highest using blastocyst injection, followed in order by 8‐cell embryo injection and 8‐cell embryo aggregation. However, the contribution rate of rat ES cells was the highest in chimeric neonates generated by 8‐cell embryo injection, and the difference was statistically significant in the liver. Live functionality was confirmed by analyzing the expression of rat hepatocyte‐derived drug‐metabolizing enzyme. Collectively, these findings indicate that the 8‐cell embryo injection method is the most suitable for generation of PSC‐derived organs via chimeric animal generation, particularly for the liver.     

No Evidence for Particular Association Between HLA-Haploidentical Hematopoietic Stem Cell Transplantation and Psychological Distress

BackgroundThe psychological distress experienced by patients scheduled for hematopoietic stem cell transplantation (HSCT) is of clinical concern. However, distress experienced by patients scheduled for HLA-haploidentical HSCT vs that of patients scheduled for other types of matched HSCT is unknown. We conducted a retrospective study to clarify whether the type of HSCT influences the appearance of psychological distress in patients anticipating HSCT.MethodsOne hundred fifty-seven patients who had undergone any of 4 types of HSCT at Tokyo Metropolitan Komagome Hospital between October 2013 and September 2016 and had completed the Profile of Mood States (POMS) questionnaire within 2 weeks before the procedure were included. We computed T-scores for the tension-anxiety (TA) and depression (D) subscales, took scores ≥ 60 to represent mood disturbance of clinical concern, and examined scores and other clinical variables in relation to each procedure.ResultsTwenty-two (14.0%) patients had a POMS-TA score ≥ 60, and 26 (16.6%) had a POMS-D score ≥ 60. The numbers of POMS-TA and POMS-D scores ≥ 60 did not differ significantly with respect to age, sex, leukemia type, number of previous transplants, disease status, comorbidity index, or transplant type. A multivariate logistic regression analysis confirmed the absence of an influence of the type of HSCT on the incidence of POMS-TA or POMS-D scores ≥60.ConclusionAttention should be paid to the matter of psychological distress in patients with leukemia who will be treated by HSCT, even HLA-haploidentical HSCT. Such patients need psychological support, especially during the waiting period immediately prior to the transplantation procedure.