ALDH1A2 (RALDH2) genetic variation in human congenital heart disease

Abstract\ud \ud \ud \ud Background\ud \ud Signaling by the vitamin A-derived morphogen retinoic acid (RA) is required at multiple steps of cardiac development. Since conversion of retinaldehyde to RA by retinaldehyde dehydrogenase type II (ALDH1A2, a.k.a RALDH2) is critical for cardiac development, we screened patients with congenital heart disease (CHDs) for genetic variation at the ALDH1A2 locus.\ud \ud \ud \ud Methods\ud \ud One-hundred and thirty-three CHD patients were screened for genetic variation at the ALDH1A2 locus through bi-directional sequencing. In addition, six SNPs (rs2704188, rs1441815, rs3784259, rs1530293, rs1899430) at the same locus were studied using a TDT-based association approach in 101 CHD trios. Observed mutations were modeled through molecular mechanics (MM) simulations using the AMBER 9 package, Sander and Pmemd programs. Sequence conservation of observed mutations was evaluated through phylogenetic tree construction from ungapped alignments containing ALDH8 s, ALDH1Ls, ALDH1 s and ALDH2 s. Trees were generated by the Neighbor Joining method. Variations potentially affecting splicing mechanisms were cloned and functional assays were designed to test splicing alterations using the pSPL3 splicing assay.\ud \ud \ud \ud Results\ud \ud We describe in Tetralogy of Fallot (TOF) the mutations Ala151Ser and Ile157Thr that change non-polar to polar residues at exon 4. Exon 4 encodes part of the highly-conserved tetramerization domain, a structural motif required for ALDH oligomerization. Molecular mechanics simulation studies of the two mutations indicate that they hinder tetramerization. We determined that the SNP rs16939660, previously associated with spina bifida and observed in patients with TOF, does not affect splicing. Moreover, association studies performed with classical models and with the transmission disequilibrium test (TDT) design using single marker genotype, or haplotype information do not show differences between cases and controls.\ud \ud \ud \ud Conclusion\ud \ud In summary, our screen indicates that ALDH1A2 genetic variation is present in TOF patients, suggesting a possible causal role for this gene in rare cases of human CHD, but does not support the hypothesis that variation at the ALDH1A2 locus is a significant modifier of the risk for CHD in humans.Work supported by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 01/000090; 00/030722; 01/142381; 02/113402; 03/099982; 04/116068; 04/157044 and Conselho Nacional de Desenvolvimento Científico e Tecnológico 481872/20078. We would like to thank the careful work and thoughtful suggestions of the two reviewers responsible for the reviewing editorial process.Work supported by grants from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 01/00009-0; 00/03072-2; 01/14238-1; 02/11340-2; 03/09998-2; 04/11606-8; 04/15704-4 and Conselho Nacional de Desenvolvimento Científico e Tecnológico 481872/2007-8. We would like to thank the careful work and thoughtful suggestions of the two reviewers responsible for the reviewing editorial process

Recipient-derived hepatocytes in sex-mismatched liver allografts after liver transplantation: Early versus late transplant biopsies

PubMed ID: 15591954Background. The presence of microchimerism in transplanted tissues is well defined; however, the timeframe of appearance and disappearance of engraftment in liver allograft is unknown. The aims of this study were to analyze for the presence of "recipient-derived cells" in sex-mismatched individuals after liver transplantation, comparing the frequency of "recipient-derived cell repopulation" in early versus late transplant biopsies and to evaluate the relationship between "recipient-derived cell repopulation" and the severity of graft injury. Methods. Paraffin-embedded liver biopsy samples of 18 recipients were reviewed. Sixteen of them were obtained from recipients with sex-mismatched donors. The remaining two were obtained from recipients with sex-matched donors and were used as controls. Immunohistochemistry and fluorescence in situ hybridization double-labeling method were performed on pretreated slides using anti-human hepatocyte antibody to identify hepatocytes, a mouse anti-human cytokeratin-7 to identify ductal epithelial cells, and using CEPX/Y DNA probes for visualizing X and Y chromosomes. The double-labeled slides were examined systematically using an image analyzer system. Results. The mean time from transplantation to biopsy was 8.1 months. Eleven of the 16 samples obtained from recipients with sex-mismatched grafts demonstrated "recipient-derived hepatocyte repopulation," comprising a mean of 2.1% of the hepatocytes. In the control biopsies, none of the cells demonstrated different nuclear signals from the donor's sex origin. The presence and proportion of "recipient-derived hepatocyte repopulation" rate were significantly higher in early transplant biopsies than in late transplant biopsies (P<0.05). Conclusion. Some hepatocytes of sex-mismatched liver grafts were replaced by "recipient-derived cells" during injury. Such repopulation is more common in the early liver-graft biopsies. The severity of acute cellular rejection appears to have no effect on the rate of recipient-derived repopulation

The efficacy of interferon-mu induction treatment with or without ribavirin in chronic hepatitis C: Interim analysis

WOS: 00016851470281

Erythrocyte-depleted allogeneic human umbilical cord blood transplantation

Cord blood is a recently recognized source of hematopoietic stem cells. It can be employed successfully to reconstitute hematopoiesis following allogeneic transplantation. One current drawback of cord blood as a treatment has been a risk of transfusion reactions attributable to ABO blood group mismatch. Removal of red cells from the cord blood has led to reduction of the stem cells by 30-50%. In this paper we report red cell depletion by a method that employs 3% gelatin to effectively sediment the erythrocytes and selectively deplete red cells but permits 94% recovery of nucleated cells and enrichment of colony-forming cells by granulocyte-macrophage colony-forming units, erythrocyte burst-forming units, and granulocyte-macrophage-megakaryocyte colony-forming units in the cord blood preparation. This technique has been employed in our study to remove red cells from the cord blood of a male infant delivered by cesarean section, which has permitted treatment of a female sibling suffering from leukemia. The recipient was 8 years old and weighted 36.7/kg. Complete HLA identity between the two siblings was established. A cord blood cell transplant of cryopreserved and later thawed cells (4 x 10(7) nucleated cells per kilogram) was administered to the patient after intensive myeloablative chemotherapy. The patient exhibited a prompt hematologic recovery (absolute neutrophil count > 500 by day 31, 100% male cells in bone marrow and peripheral blood by day 25) and has experienced a 13-month disease-free survival to date