Mesenchymal stem cells have been shown to mediate immunomodulatory effects. They have been used in patients with steroid-refractory acute GVHD (aGVHD), but their relevance as a therapeutic agent targeting aGVHD has still to be defined. In this case series, we report 13 patients with steroid-refractory aGVHD who received BM-derived MSC expanded in platelet lysatecontaining medium from unrelated HLA disparate donors. MSC were characterized by their morphological, phenotypical and functional properties. All tested preparations suppressed the proliferation of in vitro activated CD4 þ T cells. MSC were transfused at a median dosage of 0.9 Â 10 6 /kg (range 0.6-1.1). The median number of MSC applications was 2 (range 1-5). Only two patients (15%) responded and did not require any further escalation of immunosuppressive therapy. Eleven patients received additional salvage immunosuppressive therapy concomitant to further MSC transfusions, and after 28 days, five of them (45%) showed a response. Four patients (31%) are alive after a median follow-up of 257 days, including one patient who initially responded to MSC treatment. In our patient cohort, response to MSC transfusion was lower than in the series reported earlier. However, our experience supports the potential efficacy of MSC in the treatment of steroid-refractory aGVHD.

Mesenchymal stromal cells (MSCs) derived from various sources have great potential for use in cell-based therapies. Since the proportion of primary MSCs contained in bone marrow or adipose tissue is low, plastic adherence and in vitro expansion are necessary to expand MSCs prior to clinical application. Human platelet-rich plasma has been introduced as an alternative serum source but functional differences have so far not been described. Here we cultured MSCs derived from human bone marrow in medium supplemented with either 10% fetal calf serum (FCS) or 5% and 10% platelet-rich plasma (PRP) until the first or second passage. Parameters under investigation were cell yield, clonogenicity, phenotype as well as migratory and differentiation potential. In addition, the secretion of SDF-1α and the induced migration of CD34(+) haematopoietic stem cells (HSCs) were investigated with regard to the different serum source. The use of PRP resulted in a significantly higher expansion rate and yield at passages 0 and 1. In addition, the level of secreted SDF-1α was significantly increased in the supernatant of MSCs cultured with FCS instead of human PRP. Consistent with this, the migration capacity of MSCs cultured with 10% FCS as well as their capability to induce the migration of CD34(+) haematopoietic progenitors in a transwell assay was higher. Our results demonstrate that human PRP can be seen as an alternative serum source to FCS for MSC cultivation. However, the requirements of the specific clinical application must be carefully considered before the respective serum source is selected.

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Preeclampsia is associated with an increased cardiovascular morbidity of mother and offspring, thus contributing to a substantial burden in women and children’s health. It has been proven that endothelial progenitor cell (EPC) numbers and functional characteristics are impaired in cardiovascular disease and preeclampsia, although causative factors for the latter have remained elusive. MicroRNA (miRNA) modifications are a potential mechanism through which exposure to an altered environment translates into the development of chronic disease. In this study, we examined whether development of preeclampsia corresponds to alterations of miRNAs in maternal- and cord-blood-derived EPC. To test this end, we analyzed maternal and neonatal miRNAs via RNA sequencing from endothelial cells of preeclamptic and healthy controls in different cell culture passages. We were able to demonstrate differentially represented miRNAs in all groups. Hsa-miR-1270 showed significantly different levels in cord blood EPC from preeclampsia versus control and was negatively correlated with mRNA levels of its predicted targets ANGPTL7 and TFRC. Transfection with an hsa-miR-1270 inhibitor decreased the tube formation capacity and chemotactic motility but did not change proliferation in vitro. Target predictions and gene set enrichment analyses identified alternative splicing as a significantly enriched pathway for hsa-miR-1270. The top miRNAs in three other groups were predicted to target transcriptional and developmental pathways. Here, we showed for the first time significantly different levels of miRNAs and differently represented mRNA levels of predicted target genes in EPC derived from preeclampsia. Understanding the effects of preeclampsia on the epigenetic mechanisms of EPC will be crucial and may provide initial insights for further evaluation of the benefits of therapies targeting this cell population.