Mutant KLF1 in Adult Anemic Nan Mice Leads to Profound Transcriptome Changes and Disordered Erythropoiesis
SCIENTIFIC REPORTS
Authors: Nebor, Danitza; Graber, Joel H.; Ciciotte, Steven L.; Robledo, Raymond F.; Papoin, Julien; Hartman, Emily; Gillinder, Kevin R.; Perkins, Andrew C.; Bieker, James J.; Blanc, Lionel; Peters, Luanne L.
Abstract
Anemic Nan mice carry a mutation (E339D) in the second zinc finger of erythroid transcription factor KLF1. Nan-KLF1 fails to bind a subset of normal KLF1 targets and ectopically binds a large set of genes not normally engaged by KLF1, resulting in a corrupted fetal liver transcriptome. Here, we performed RNAseq using flow cytometric-sorted spleen erythroid precursors from adult Nan and WT littermates rendered anemic by phlebotomy to identify global transcriptome changes specific to the Nan Klf1 mutation as opposed to anemia generally. Mutant Nan-KLF1 leads to extensive and progressive transcriptome corruption in adult spleen erythroid precursors such that stress erythropoiesis is severely compromised. Terminal erythroid differentiation is defective in the bone marrow as well. Principle component analysis reveals two major patterns of differential gene expression predicting that defects in basic cellular processes including translation, cell cycle, and DNA repair could contribute to disordered erythropoiesis and anemia in Nan. Significant erythroid precursor stage specific changes were identified in some of these processes in Nan. Remarkably, however, despite expression changes in large numbers of associated genes, most basic cellular processes were intact in Nan indicating that developing red cells display significant physiological resiliency and establish new homeostatic set points in vivo.
Molecular and biochemical study of glutaric aciduria type 1 in 49 Russian families: nine novel mutations in the GCDH gene
METABOLIC BRAIN DISEASE
Authors: Kurkina, Marina V.; Mihaylova, Svetlana V.; Baydakova, Galina V.; Saifullina, Elena V.; Korostelev, Sergey A.; Pyankov, Denis V.; Kanivets, Ilya V.; Yunin, Maksim A.; Pechatnikova, Natalya L.; Zakharova, Ekaterina Y.
Abstract
Glutaric aciduria type 1 (GA1, deficiency of glutaryl CoA dehydrogenase, glutaric acidemia type 1) (ICD-10 code: E72.3; MIM 231670) is an autosomal recessive disease caused by mutations in the gene encoding the enzyme glutaryl CoA dehydrogenase (GCDH). Herein, we present the biochemical and molecular genetic characteristics of 51 patients diagnosed with GA1 from 49 unrelated families in Russia. We identified a total of 21 variants, 9 of which were novel: c.127 + 1G > T, c.471_473delCGA, c.161 T > C (p.Leu54Pro), c.531C > A (p.Phe177Leu), c.647C > T (p.Ser216Leu), c.705G > A (p.Gly235Asp), c.898 G > A (p.Gly300Ser), c.1205G > C (p.Arg402Pro), c.1178G > A (p.Gly393Glu). The most commonly detected missense variants were c.1204C > T (p.Arg402Trp) and c.1262C > T (p.Ala421Val), which were identified in 56.38% and 11.7% of mutated alleles. A heterozygous microdeletion of the short arm (p) of chromosome 19 from position 12,994,984-13,003,217 (8233 b.p.) and from position 12,991,506-13,003,217 (11,711 b.p.) were detected in two patients. Genes located in the area of imbalance were KLF1, DNASE2, and GCDH. Patients presented typical GA1 biochemical changes in the biological fluids, except one patient with the homozygous mutation p.Val400Met. No correlation was found between the GCDH genotype and glutaric acid (GA) concentration in the cohort of our patients.