Rescue allocation and recipient oriented extended allocation in kidney transplantation-influence of the EUROTRANSPLANT allocation system on recipient selection and graft survival for initially nonaccepted organs.

Nonaccepted kidneys grafts enter the rescue allocation (RA) process to avoid discards. In December 2013, recipient oriented extended allocation (REAL) was introduced to improve transparency. The aim of this study was to evaluate the influence of REAL on recipients' selection and graft function compared to the formerly existing RA as well as to identify factors that influence graft outcome. Therefore, a multicenter study of 10 transplant centers in the same region in Germany was performed. All transplantations after RA or REAL from December 1, 2012, until December 31, 2014, with a follow-up time until December 31, 2015 were analyzed. 113 of 941 kidney transplantations were performed after RA or REAL (12%). With REAL, the number of refusals before transplantation had increased (12 ± 7.1 vs. 8.6 ± 8.6, P = 0.036), and cold ischemia time has decreased (13.6 ± 3.6 vs. 17.2 ± 4.8 h, P = 0.019). Recipients after REAL needed significantly more allocation points compared to RA to receive a kidney. One-year graft survival was comparable. If kidneys from the same donor were transplanted to two recipients at one center, the greater the difference in recipient age, the greater the difference in serum creatinine after 12 months (-0.019 mg/dl per year, P = 0.011) was, that is older recipients showed lower creatinine. REAL influences selection of the recipients compared to the former RA era for successful organ receipt. Graft function is comparable and seems to be influenced by recipient age.

Inhibition of Notch Signaling Ameliorates Acute Kidney Failure and Downregulates Platelet-Derived Growth Factor Receptor ß in the Mouse Model.

Ischemic acute kidney injury (AKI) is associated with high morbidity and frequent complications. Repeated episodes of AKI may lead to end-stage renal failure. The pathobiology of regeneration in AKI is not well understood and there is no effective clinical therapy that improves regeneration. The Notch signaling pathway plays an essential role in kidney development and has been implicated in tissue repair in the adult kidney. Here, we found that kidneys after experimental AKI in mice showed increased expression of Notch receptors, specifically Notch1-3, of the Notch ligands Jagged-1 (Jag1), Jag2 and Delta-like-4 (Dll4) and of the Notch target genes Hes1, Hey2, HeyL, Sox9 and platelet-derived growth factor receptor ß (Pdgfrb). Treatment of ischemic mice with the x03B3;-secretase inhibitor DBZ blocked Notch signaling and specifically downregulated the expression of Notch3 and the Notch target genes Hes1, Hey2, HeyL and Pdgfrb. After DBZ treatment, the mice developed less interstitial edema and displayed altered interstitial inflammation patterns. Furthermore, serum urea and creatinine levels were significantly decreased from 6 h onwards when compared to control mice treated with DMSO only. Our data are consistent with an amelioration of the severity of kidney injury by blocking Notch activation following AKI, and suggest an involvement of Notch-regulated Pdgfrb in AKI pathogenesis.

Erythropoietin-enhanced endothelial progenitor cell recruitment in peripheral blood and renal vessels during experimental acute kidney injury in rats.

Beneficial effects of erythropoietin (EPO) have been reported in acute kidney injury (AKI) when administered prior to induction of AKI. We studied the effects of EPO administration on renal function shortly after ischemic AKI. For this purpose, rats were subjected to renal ischemia for 30 min and EPO was administered at a concentration of 500 U/kg either i.v. as a single shot directly after ischemia or with an additional i.p. dose until 3 days after surgery. The results were compared with AKI rats without EPO application and a sham-operated group. Renal function was assessed by measurement of serum biochemical markers, histological grading, and using an isolated perfused kidney (IPK) model. Furthermore, we performed flow cytometry to analyze the concentration of endothelial progenitor cells (EPCs) in the peripheral blood and renal vessels. Following EPO application, there was only a statistically non-significant tendency of serum creatinine and urea to improve, particularly after daily EPO application. Renal vascular resistance and the renal perfusion rate were not significantly altered. In the histological analysis, acute tubular necrosis was only marginally ameliorated following EPO administration. In summary, we could not demonstrate a significant improvement in renal function when EPO was applied after AKI. Interestingly, however, EPO treatment resulted in a highly significant increase in CD133- and CD34-positive EPC both in the peripheral blood and renal vessels.

Gluteal and abdominal subcutaneous adipose tissue depots as stroma cell source: gluteal cells display increased adipogenic and osteogenic differentiation potentials.

Human adipose-derived stroma cells (ADSCs) have successfully been employed in explorative therapeutic studies. Current evidence suggests that ADSCs are unevenly distributed in subcutaneous adipose tissue; therefore, the anatomical origin of ADSCs may influence clinical outcomes. This study was designed to investigate proliferation and differentiation capacities of ADSCs from the gluteal and abdominal depot of 8 females. All had normal BMI (22.01 ± 0.39 kg/m(2) ) and waist circumference (81.13 ± 2.33 cm). Examination by physicians and analysis of 31 laboratory parameters did not reveal possibly confounding medical disorders. Gluteal and abdominal adipose tissue was sampled by en bloc resection on day 7 (±1) after the last menses. Histological examination did not reveal significant depot-specific differences. As assessed by BrdU assay, proliferation of cells from both depots was similar after 24 h and analysis of 15 cell surface markers by flow cytometry identified the isolated cells as ADSCs, again without depot-specific differences. ADSCs from both depots differentiated poorly to chondroblasts. Gluteal ADSCs displayed significantly higher adipogenic differentiation potential than abdominal cells. Osteogenic differentiation was most pronounced in gluteal cells, whereas differentiation of abdominal ADSCs was severely impaired. Our data demonstrate a depot-specific difference in ADSC differentiation potential with abdominal cells failing to meet the criteria of multipotent ADSCs. This finding should be taken into account in future explorations of ADSC-derived therapeutic strategies.

Generation of induced pluripotent stem cells (iPSCs) from human foreskin fibroblasts.

The human iPS cell line VUZUZLi001-A (hVH-1) was generated from human foreskin fibroblasts to be used as a control line. Reprogramming was performed by retroviral transduction of reprogramming factors OCT4, SOX2, KLF4 and c-MYC. Resource table.

Accelerated and safe expansion of human mesenchymal stromal cells in animal serum-free medium for transplantation and regenerative medicine.

Human bone marrow mesenchymal stromal cells (hMSC) are currently investigated for a variety of therapeutic applications. However, most expansion protocols still use fetal calf serum (FCS) as growth factor supplement which is a potential source of undesired xenogeneic pathogens. We established an expansion protocol for hMSC based on the use of GMP-produced basic medium LP02 supplemented with 5% of platelet lysate (PL) obtained from human thrombocyte concentrates. Compared to FCS-supplemented culture conditions, we found a significant increase in both colony forming unit-fibroblast (CFU-F) as well as cumulative cell numbers after expansion. This accelerated growth is optimized by pooling of at least 10 thrombocyte concentrates. A minimal requirement is the use of 5% of PL with an optimal platelet concentration of 1.5 x 10(9)/ml, and centrifugation of thawed lysate at high speed. Cells expanded by this protocol meet all criteria for mesenchymal stromal cells (MSCs), e.g. plastic adherence, spindle-shaped morphology, surface marker expression, lack of hematopoietic markers, and differentiation capability into three mesenchymal lineages. MSC at passage 6 were cytogenetically normal and retained their immune-privileged potential by suppressing allogeneic reaction of T-cells. Additionally, gene expression profiles show increased mRNA levels of genes involved in cell cycle and DNA replication and downregulation of developmental and differentiation genes, supporting the observation of increased MSC-expansion in PL-supplemented medium. In summary, we have established a GMP-compatible protocol for safe and accelerated expansion of hMSC to be used in cell and tissue therapy.