ALBERT

Description: MicroRNAs (miRs) have emerged as key biological effectors in human health and disease. These small noncoding RNAs are incorporated into Argonaute (Ago) proteins, where they direct post-transcriptional gene silencing via base-pairing with target transcripts. Although miRs have become intriguing biological entities and attractive therapeutic targets, the translational impacts of miR research remain limited by a paucity of empirical miR targeting data, particularly in human primary tissues. Here, to improve our understanding of the diverse roles miRs play in cardiovascular function and disease, we applied high-throughput methods to globally profile miR:target interactions in human heart tissues. We deciphered Ago2:RNA interactions using crosslinking immunoprecipitation coupled with high-throughput sequencing (HITS-CLIP) to generate the first transcriptome-wide map of miR targeting events in human myocardium, detecting 4000 cardiac Ago2 binding sites across 〉2200 target transcripts. Our initial exploration of this interactome revealed an abundance of miR target sites in gene coding regions, including several sites pointing to new miR-29 functions in regulating cardiomyocyte calcium, growth and metabolism. Also, we uncovered several clinically-relevant interactions involving common genetic variants that alter miR targeting events in cardiomyopathy-associated genes. Overall, these data provide a critical resource for bolstering translational miR research in heart, and likely beyond.

Description: Forty successful marrow grafts have been carried out since April 1972 for the treatment of severe refractory aplastic anemia or acute leukemia. All patients were HL-A identical and nonreactive in mixed leukocyte culture tests with the marrow donor. Nineteen of the patients developed moderately severe to severe graft-versus-host disease (GVHD) and were treated with rabbit or goat antihuman antithymocyte globulin (ATG). Under ATG therapy, 12 of the 19 showed complete resolution of GVHD, five showed improvement of most organ systems involved, and two showed no change except for improvement in skin lesions. Six of the 19 became long-term survivors. Five of the six are alive between 276 and 629 days after grafting, and one died on day 346 with chronic respiratory failure. Of the remaining 13 patients, 11 died with interstitial pneumonitis of predominantly viral etiology, and two died with fungal and bacterial infections. In conclusion, the present study demonstrates the relative effectiveness of ATG in reversing human GVHD. Death with interstitial pneumonitis was the single most serious impediment to successful treatment of GVHD by ATG.

Description: Twenty-four patients with severe aplastic anemia, 14 due to unknown cause, four associated with hepatitis, four drug or chemical related, one with paroxysmal nocturnal hemoglobinuria, and one possibly associated with a Fanconi syndrome did not show spontaneous recovery after 2-24 mo of conventional therapy. Eleven were infected and nine were refractory to random platelet transfusions at the time of admission. All received marrow grafts from HL-A identical siblings. Eighteen were conditioned for grafting by cyclophosphamide (CY), 50 mg/kg on each of 4 successive days, and 6 by 1000 rad total body irradiation (TBI). All received intermittent methotrexate (MTX) therapy within the first 100 days postgrafting to modify graftversus-host disease (GvHD). One patient died on the day of grafting of congestive heart failure possibly related to CY cardiac toxicity. One died on day 6 with septicemia. One died on day 24 without engraftment. Twenty-one patients showed prompt hemopoietic engraftment indicated by rising blood counts, return of marrow cellularity, and in most instances confirmed by blood genetic markers. Four rejected the graft and died on days 33, 41, 51, and 67. Four died between days 45 and 85 with GvHD. One died of cytomegalovirus infection on day 91. One with chronic active hepatitis died on day 427 of unknown causes. Eleven are alive with grafts and without GvHD more than 141, 144, 163, 186, 189, 255, 344, 472, 641, 746, and 823 days after grafting, and ten have returned to normal activity. These results show that normal stem cells will repopulate the marrow in patients with aplastic anemia and demonstrate that long-term stable chimerism is possible in man. They suggest that marrow grafting in patients with complete marrow failure and an HL-A matched sibling should be undertaken before major infections and refractoriness to blood transfusions complicate their course.