BioProject

Human bone marrow is a complex, diversified and well-organized hematopoietic network changing composition with age. More...

Human bone marrow is a complex, diversified and well-organized hematopoietic network changing composition with age. The purpose of this study was to analyze variations in relative precursor B cell abundance in bone marrow with age by means of global gene expression profiling. RNA was isolated from composite bone marrow from 25 healthy children, adolescents and adults age 2 months to 28 years. As reference transcript for precursor B cells we used recombination activating gene RAG1 exploring the data for other transcripts showing the same profile as RAG1 with age. We identified 54 genes with correlated expression profiles to RAG1 (r ≥ 0.9, p = 0), characterized by high expression at 3 - 20 months followed by a fast decline to lower signal levels maintained until early adulthood. Immunophenotyping from a similar healthy age-matched cohort (n = 37) showed a comparable decrease of precursor B cells. Of the 54 genes 15 were characteristically B cell associated representing cell surface molecules (CD19, CD72, CD79A, CD79B, CD180, IGL@, IGLL1, VPREB1, VPREB3), a signal transduction molecule (BLNK) and transcription factors (DNTT, EBF1, PAX5, POU2AF1, RAG2). Of the remaining transcripts some may represent novel B cell transcripts or genes involved in control of B cells. Bone marrow was obtained from healthy children eligible for elective minor surgery and voluntary health care workers. The bone marrow samples (2.5ml) were immediately after aspiration transferred to PAXgene tubes for mRNA stabilization before RNA extraction and hybridization on Affymetrix microarrays. To that end, the study presents a picture of the total marrow activity with minimal manipulation that would otherwise influence gene expression results. Overall design: We used microarrays to determine age-related changes in precursor B cell transcripts in bone marrow from 25 healthy children and adults and searched for other transcripts showing the same expression profile with age. Less...