MicroRNA profiling of the murine hematopoietic system.
BACKGROUND
MicroRNAs (miRNAs) are a class of recently discovered noncoding RNA genes that post-transcriptionally regulate gene expression. It is becoming clear that miRNAs play an important role in the regulation of gene expression during development. However, in mammals, expression data are principally based on whole tissue analysis and are still very incomplete.


RESULTS
We used oligonucleotide arrays to analyze miRNA expression in the murine hematopoietic system. Complementary oligonucleotides capable of hybridizing to 181 miRNAs were immobilized on a membrane and probed with radiolabeled RNA derived from low molecular weight fractions of total RNA from several different hematopoietic and neuronal cells. This method allowed us to analyze cell type-specific patterns of miRNA expression and to identify miRNAs that might be important for cell lineage specification and/or cell effector functions.


CONCLUSIONS
This is the first report of systematic miRNA gene profiling in cells of the hematopoietic system. As expected, miRNA expression patterns were very different between hematopoietic and non-hematopoietic cells, with further subtle differences observed within the hematopoietic group. Interestingly, the most pronounced similarities were observed among fully differentiated effector cells (Th1 and Th2 lymphocytes and mast cells) and precursors at comparable stages of differentiation (double negative thymocytes and pro-B cells), suggesting that in addition to regulating the process of commitment to particular cellular lineages, miRNAs might have an important general role in the mechanism of cell differentiation and maintenance of cell identity.
Monticelli
Silvia
S
Department of Pathology, Harvard Medical School, and CBR Institute for Biomedical Research, Boston, MA 02115, USA. monticel@cbr.med.harvard.edu
Ansel
K Mark
KM
Xiao
Changchun
C
Socci
Nicholas D
ND
Krichevsky
Anna M
AM
Thai
To-Ha
TH
Rajewsky
Nikolaus
N
Marks
Debora S
DS
Sander
Chris
C
Rajewsky
Klaus
K
Rao
Anjana
A
Kosik
Kenneth S
KS
D000818:Animals; D015152:Blotting, Northern; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006413:Hematopoietic System / Q000378:metabolism*; D051379:Mice; D035683:MicroRNAs / Q000032:analysis* / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015203:Reproducibility of Results; D012107:Research Design
D035683:MicroRNAs; D012333:RNA, Messenger