ALBERT

Description: 〈p〉Complex genetic mechanisms are thought to underlie many human diseases, yet experimental proof of this model has been elusive. Here, we show that a human cardiac anomaly can be caused by a combination of rare, inherited heterozygous mutations. Whole-exome sequencing of a nuclear family revealed that three offspring with childhood-onset cardiomyopathy had inherited three missense single-nucleotide variants in the 〈i〉MKL2〈/i〉, 〈i〉MYH7〈/i〉, and 〈i〉NKX2-5〈/i〉 genes. The 〈i〉MYH7〈/i〉 and 〈i〉MKL2〈/i〉 variants were inherited from the affected, asymptomatic father and the rare 〈i〉NKX2-5〈/i〉 variant (minor allele frequency, 0.0012) from the unaffected mother. We used CRISPR-Cas9 to generate mice encoding the orthologous variants and found that compound heterozygosity for all three variants recapitulated the human disease phenotype. Analysis of murine hearts and human induced pluripotent stem cell–derived cardiomyocytes provided histologic and molecular evidence for the 〈i〉NKX2-5〈/i〉 variant’s contribution as a genetic modifier.〈/p〉

Description: Replacement of precious noble metal catalysts with low-cost, non-noble heterogeneous catalysts for chemoselective reduction and reductive coupling of nitro compounds holds tremendous promise for the clean synthesis of nitrogen-containing chemicals. We report a robust cobalt–nitrogen/carbon (Co–N x /C-800-AT) catalyst for the reduction and reductive coupling of nitro compounds into amines and their derivates. The Co–N x /C-800-AT catalyst was prepared by the pyrolysis of cobalt phthalocyanine–silica colloid composites and the subsequent removal of silica template and cobalt nanoparticles. The Co–N x /C-800-AT catalyst showed extremely high activity, chemoselectivity, and stability toward the reduction of nitro compounds with H 2 , affording full conversion and 〉97% selectivity in water after 1.5 hours at 110°C and under a H 2 pressure of 3.5 bar for all cases. The hydrogenation of nitrobenzene over the Co–N x /C-800-AT catalyst can even be smoothly performed under very mild conditions (40°C and a H 2 pressure of 1 bar) with an aniline yield of 98.7%. Moreover, the Co–N x /C-800-AT catalyst has high activity toward the transfer hydrogenation of nitrobenzene into aniline and the reductive coupling of nitrobenzene into other derivates with high yields. These processes were carried out in an environmentally friendly manner without base and ligands.

Description: Despite stem cell transplant and new therapies, nearly all patients with AL and MM die of disease or complications of treatment. Novel approaches that selectively kill clonal plasma cells are needed. CD32B, the inhibitory Fcγ receptor IIB, is a member of the Fc receptor (FcR) family on chromosome 1q. B-cells and some monocytes and dendritic cell subtypes express cell-surface CD32B, which has a cytoplasmic inhibitory motif important in regulating immune responses. Unlike the CD32B2 isoform on myeloid cells, CD32B1 on B-cells is not internalized, making it a suitable target for monoclonal antibody (MAb) therapy (Blood 2006Jun6 Epub). CD32B has not previously been found on AL and MM plasma cells. We used purified CD138+ marrow and blood cells from AL, MM and plasma cell leukemia (PCL) patients, and 5 human MM cell lines, to evaluate CD32B gene and cell-surface expression with gene expression profiles (GEP) (Affymetrix U133 PLUS 2.0), RT-PCR for CD32B1 and B2, and flow-cytometry with the 2B6 MAb for CD32B. In AL, GEP showed that CD32B expression was significantly higher than other FcR genes (p98% of all AL plasma cells. In MM, public GEP data (http://lambertlab.uams) showed that CD32B expression was significantly higher than other FcR genes while RT-PCR showed CD32B1 message in CD138+ MM and PCL specimens but not in the RPMI 8226 cell line. Cytogenetic analysis then showed that 8226 cells lack t(4;14) but have 4 copies of 1q, implicating segmental uniparental tetrasomy of a mutant allele in the lack of CD32B message. Flow cytometry showed median 96% CD32B expression on CD138+ marrow cells from patients with normal or hyperdiploid cytogenetics, but significantly lower expression (median 69%, p=0.01) in patients with unfavorable cytogenetics (del 13, t(4;14)). CD32B expression was lower still on PCL specimens (median 10%) and nil on MM cell lines. We then investigated the GEP of sorted CD138+/CD32B+ and CD32B− fractions from MM patients. In CD138+/CD32B+ cells, CD45C and CXCR4 were overexpressed. In CD138+/CD32B− cells, genes on chromosome 1q were overexpressed, including those for cancer testis antigens and others possibly associated with biologic aggressivity (Cancer Cell2006;9:313). Notably, the CD32B-specific MAb 2B6 directs human mononuclear cell cytotoxicity against CD32B+ cell lines, reduces tumor growth and improves tumor-free survival in a mouse xenograft model. Moreover, an Fc-engineered humanized variant of 2B6 elicits ADCC-mediated specific cytotoxicity against a low-level CD32B+ MM cell line in vitro. In sum, these data show that CD32B is important in AL and MM; that CD32B on AL and the majority of MM plasma cells provides a target for MAb therapy; and that, given the results in MM, PCL and MM cell lines, CD32B expression is inversely related to biologic aggressivity. Genetic instability of chromosome 1q may provide a direct basis for this relationship thereby mechanistically linking CD32B expression in MM to prognosis. These data support further evaluation of CD32B and clinical studies of anti-CD32B MAb therapy in AL and MM.