Large nucleoli have generally been believed to be present in less differentiated and proliferating cells including the malignant ones. Such nucleoli have also been considered to be active in the biosynthetic process and major cell developmental activities. In contrast, after cytostatic treatment, apoptotic leukaemic progenitors still containing nuclei did not exhibit substantial reduction of the nucleolar size but displayed decreased nucleolar biosynthetic activity. The present study was undertaken to provide more information on the large nucleoli in spontaneously occurring apoptotic leukaemic progenitors without further differentiation. Leukaemic progenitors of established cell lineages originating from leukaemic patients represented a very convenient model for such study. Some of them exhibit morphological signs of the spontaneously occurring apoptotic process. Since such signs are expressed by nuclear and cytoplasmic morphological variability, the present study dealt with spontaneously occurring apoptotic progenitors with preserved nuclei characterized by heavy chromatin condensation and occasional fragmentation. Based of nucleolar body and nuclear maximal diameter measurements it seems to be clear that the nucleolar size in these cells was not substantially reduced, contrary to that of the nucleus. However, large nucleolar bodies in spontaneously occurring apoptotic cells were characterized by markedly reduced biosynthetic activity, as expressed by the decreased number of nucleolar transcription markers such as nucleolar fibrillar centres. In conclusion, large nucleoli may be present not only in proliferating, but also in spontaneously occurring apoptotic cells.
The present study was undertaken to provide more information on the differentiation and maturation of human granulocytes using computer-assisted image RNA densitometry at single-cell level. The bone marrow of patients suffering from chronic phase of chronic myeloid leukemia represents a very convenient model for such measurements because of the satisfactory number of early stages, as well as advanced stages, of the granulocytic cell lineage represented by neutrophils. In contrast to the erythroid cell lineage, similar nucleolar and cytoplasmic RNA density-concentration values were found only in early granulocytic progenitors such as myeloblasts and promyelocytes. In advanced stages of the granulocytic development starting with myelocytes, these cells were characterized by a larger decrease in the cytoplasmic RNA concentration in comparison with that of the nucleoli. Thus, the nucleolar to cytoplasmic RNA concentration ratio in these cells was above 1. On the other hand, it should be pointed out that late differentiation stages of granulocytes, starting with myelocytes, possessed nucleolar bodies (nucleoli without surrounding perinucleolar chromatin) of a markedly reduced size.
- MeSH
- biopsie MeSH
- buněčná diferenciace MeSH
- buněčné jadérko ultrastruktura MeSH
- buněčný rodokmen MeSH
- chronická nemoc MeSH
- cytoplazma metabolismus ultrastruktura MeSH
- denzitometrie MeSH
- lidé MeSH
- myeloidní leukemie krev metabolismus patologie MeSH
- počítačové zpracování obrazu MeSH
- prekurzorové buňky granulocytů metabolismus ultrastruktura MeSH
- RNA analýza MeSH
- velikost částic MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVES: MicroRNAs (miRNAs) play key roles in a wide variety of normal and pathological cellular processes. A number of studies identified hematopoietic-specific miRNAs that are necessary for correct function of blood cells. Out of our microarray data, we chose 13 miRNAs that showed differential expression in peripheral blood cells (miR-15b, miR-16, miR-24, miR-30c, miR-106b, miR-142-3p, miR-142-5p, miR-150, miR-155, miR-181, miR-223, miR-342, and miR-451) and examined their expression in separated hematopoietic cell lineages. METHODS: Using quantitative real-time polymerase chain reaction, we measured relative expression of the miRNAs in fractions of reticulocytes, platelets, granulocytes, monocytes, B- and T-lymphocytes as well as in several hematopoietic cell lines. RESULTS: We observed that miR-16 and miR-142-3p were highly expressed in all native cell lineages, miR-451 reached the maximal expression in reticulocytes, miR-223 in platelets, granulocytes and monocytes, and miR-150 in B- and T-lymphocytes. Hierarchical clustering analysis grouped the lineage samples according to their origin based on the expression of these miRNAs. To validate discrimination power of the miRNAs, we quantified expression of the 13 miRNAs in several immortalized cell lines. Although the cell lines showed miRNA expression patterns considerably different from those of native cell lineages, clustering analysis distinguished between myeloid, lymphoid and non-hematopoietic cells. CONCLUSIONS: In conclusion, the study reports the expression levels of 13 miRNAs in particular blood cell lineages as well as immortalized cell lines. We demonstrate that the expression profiles of these miRNAs may be used for discrimination of the hematopoietic cell lineages.
- MeSH
- buněčná diferenciace fyziologie MeSH
- buňky K562 MeSH
- financování organizované MeSH
- HeLa buňky MeSH
- leukocyty cytologie metabolismus MeSH
- lidé MeSH
- lymfoidní progenitorové buňky cytologie metabolismus MeSH
- mikro RNA biosyntéza MeSH
- prekurzorové buňky granulocytů cytologie metabolismus MeSH
- regulace genové exprese fyziologie MeSH
- retikulocyty cytologie metabolismus MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů metody MeSH
- stanovení celkové genové exprese metody MeSH
- trombocyty cytologie metabolismus MeSH
- Check Tag
- lidé MeSH
