BackgroundThe role of histocompatibility and immune recognition in stem cell transplant therapy has been controversial, with many reports arguing that undifferentiated stem cells are protected from immune recognition due to the absence of major histocompatibility complex (MHC) markers. This argument is even more persuasive in transplantation into the central nervous system (CNS) where the graft rejection response is minimal.Methodology/Principal FindingsIn this study, we evaluate graft survival and neuron production in perfectly matched vs. strongly mismatched neural stem cells transplanted into the hippocampus in mice. Although allogeneic cells survive, we observe that MHC-mismatch decreases surviving cell numbers and strongly inhibits the differentiation and retention of graft-derived as well as endogenously produced new neurons. Immune suppression with cyclosporine-A did not improve outcome but non-steroidal anti-inflammatory drugs, indomethacin or rosiglitazone, were able to restore allogeneic neuron production, integration and retention to the level of syngeneic grafts.Conclusions/SignificanceThese results suggest an important but unsuspected role for innate, rather than adaptive, immunity in the survival and function of MHC-mismatched cellular grafts in the CNS.
Background-Cell transplantation for myocardial repair is limited by early cell death. Gene therapy with human Bcl-2 (hBcl-2) has been shown to attenuate apoptosis in the experimental setting. Therefore, we studied the potential benefit of hBcl-2 transgene expression on the survival of cardiomyoblast grafts in ischemic rat hearts. Methods and Results-H9c2 rat cardiomyoblasts were genetically modified to express both firefly luciferase and green fluorescent protein (mH9c2). The cells were then transduced with adenovirus carrying hBcl-2 (AdCMVhBcl-2/mH9c2). Lewis rats underwent ligation of the left anterior descending artery (LAD) to induce a sizable left ventricular (LV) infarct. Hearts were explanted and the infarcted region was restored using collagen matrix (CM) seeded with 1ϫ10 6 mH9c2 cells (nϭ9) or AdCMVhBcl-2/mH9c2 cells (nϭ9). Control animals received CM alone (nϭ6) or no infarct (nϭ6). Restored hearts were transplanted into the abdomen of syngeneic recipients in a "working heart" model. Cell survival was evaluated using optical bioluminescence imaging on days 1, 5, 8, 14, and 28 after surgery. The left heart function was assessed 4 weeks postoperatively using echocardiography and magnetic resonance imaging. During 4 weeks after surgery, the optical imaging signal for the AdCMVhBCL2/mH9c2 group was significantly (PϽ0.05) higher than that of the mH9c2-control group. Both grafts led to better fractional shortening (AdCMVhBcl-2/mH9c2: 0.
Female pigs are commonly utilized as an animal model for biomedical research and require urethral catheterization. Sixteen pigs were anaesthetized for research purposes and required the placement of a urethral catheter. Post-mortem examination of the vaginas revealed the urethral opening to be consistently halfway from the mucocutaneous junction of the vulva to the cervix. A shallow diverticulum was also observed on the ventral floor of the urethral opening. To optimize conditions for success the pig should be carefully positioned supine, a vaginal speculum and light source should be used, the pig should be adequately anaesthetized, and the anatomy of the vagina should be reviewed.
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