Gene expression profiles following intracoronary injection of mesenchymal stromal cells using a porcine model of chronic myocardial infarction.

BACKGROUND AIMS: We evaluated the therapeutic potential of injection of in vitro differentiated bone marrow mesenchymal stromal cells (MSC) using a swine model. METHODS AND RESULTS: Myocardial infarction was induced by coronary occlusion. Three groups (n = 5 each) were analyzed: one group received an injection of 17.8 ± 9.3 × 10(6) 5-azacytidine-treated allogeneic MSC 1 month after infarction; a placebo group received an injection of medium; and controls were kept untreated. After 4 weeks, heart samples were taken from three infarcted areas, interventricular septa, ventricles and atria. Gene expression profiles of genes related to contractility (Serca2a), fibrosis (Col1a1), cardiomyogenesis (Mef2c, Gata4 and Nkx2.5) and mobilization of stem cells (Sdf1, Cxcr4 and c-kit) were compared by quantitative real-time PCR (qRT-PCR). Gene expression profiles varied in different heart areas. Thus Serca2a expression was reduced in infarcted groups in all heart regions except for the left ventricles, where Col1a1 was overexpressed. The expression of genes related to cardiomyogenesis decreased in the infarcted zones and left atria compared with healthy hearts. Interestingly, increased expression of Cxcr4 was detected in infarcted regions of MSC-treated pigs compared with the placebo group. CONCLUSIONS: Infarction induced changes in expression of genes involved in various biologic processes. Genes involved in cardiomyogenesis were downregulated in the left atrium. The intracoronary injection of MSC resulted in localized changes in the expression of Cxcr4.

Lack of cross-species transmission of porcine endogenous retrovirus in pig-to-baboon xenotransplantation with sustained depletion of anti-alphagal antibodies.

BACKGROUND: Nonhuman primates are potential permissive animals for studying the risk of in vivo infection with porcine endogenous retrovirus (PERV). Anti-alphaGal natural antibodies are considered one of the barriers for preventing PERV infection, and it has been postulated that reduction of these antibodies could increase the risk of this infection. The aim of this study was to investigate the role of GAS 914, which depletes anti-alphaGal antibodies, in the potential in vivo transfer of PERV after pig-to-baboon organ xenotransplantation. METHODS: Twenty-seven baboons underwent xenotransplantation with hDAF or hMCP/hDAF transgenic pig organs, including heterotopic heart (n = 14) and kidney (n = 13) transplants. All of them received GAS 914 along with different immunosuppression protocols. PERV sequences were investigated by reverse-transcriptase polymerase chain reaction and by polymerase chain reaction assays in samples obtained at autopsy. The presence of PERV-specific antibodies and/or pig xenomicrochimerism was also evaluated. RESULTS: PERV RNA was not detected in any baboon plasma sample. In addition, all plasma samples were negative for PERV antibodies. However, PERV DNA sequences were detected in peripheral blood mononuclear cells from 6 of 14 (43%) animals investigated. Porcine mitochondrial DNA was also found in all of these positive samples and in six of the eight (75%) samples with negative PERV DNA, indicating that the detection of PERV sequences was attributable to xenochimerism. PERV-positive cells as a result of xenochimerism were also found in eight of nine (89%) spleen and lymph node tissue samples tested. CONCLUSIONS: Sustained depletion of anti-alphaGal antibodies does not augment the risk of PERV infection in pig-to-baboon organ transplantation.