Progenitor cells of the human erythroid and granulocytic cell lineages are characterized by the presence of several nucleoli. One of these nucleoli is larger and possesses more fibrillar centres than others. Such nucleolus is apparently dominant in respect of both size and main nucleolar function such as nucleolar-ribosomal RNA transcription. Such nucleolus is also visible in specimens using conventional visualization procedures, in contrast to smaller nucleoli. In the terminal differentiation nucleated stages of the erythroid and granulocytic development, dominant nucleoli apparently disappeared, since these cells mostly contained very small nucleoli of a similar size with one fibrillar centre. Thus, the easily visible dominant nucleoli appear to be useful markers of the progenitor cell state, such as proliferation, and differentiation potential.
- MeSH
- buněčná diferenciace MeSH
- buněčné dělení MeSH
- buněčné jadérko fyziologie ultrastruktura MeSH
- buněčné jádro ultrastruktura MeSH
- buněčný rodokmen MeSH
- erytroidní prekurzorové buňky ultrastruktura MeSH
- granulocyty ultrastruktura MeSH
- lidé MeSH
- prekurzorové buňky granulocytů ultrastruktura MeSH
- RNA ribozomální metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The knowledge on the heterochromatin condensation state (HChCS) in central nuclear “gene rich” regions is limited although the heterochromatin reflects the gene silencing. Therefore, the HChCS in these regions was studied in proliferating granulocytic progenitors and terminally differentiated (mature) neutrophilic granulocytes. The HChCS was measured using computer assisted image optical densitometry at the single cell level. The bone marrow smears of patients with chronic myeloid leukemia represented a convenient model because of the increased number of progenitor and mature cells for density measurements. In addition, the heterochromatin density of central nuclear regions was also measured in myeloblasts of the K 562 cell lineage originated from the patient with that disease. The HChCS in central nuclear regions of both granulocytic progenitors and mature granulocytes was heterogeneous. The maximal and minimal density values were about 9-10 per cent above and below mean values in both myeloblasts and mature granulocytes. The heavy condensed heterochromatin of central nuclear region might reflect the location of silent genes during the whole granulocytic development. In contrary, the less condensed heterochromatin structures in central nuclear regions of granulocytic progenitors and mature granulocytes might just represent foci with the potential for the gene activation regardless of the differentiation and maturation stage. The HChCS in central nuclear regions was larger in small nuclear segments of mature granulocytes than in large nuclei of their progenitors. The HChCS was also increased in apoptotic K 562 myeloblasts with the decreased nuclear diameter. Such phenomena opened an “old - new” question on mutual relationship between the reduced nuclear size and the HChCS.
- MeSH
- biomedicínský výzkum MeSH
- chronická myeloidní leukemie krev MeSH
- denzitometrie * metody přístrojové vybavení využití MeSH
- granulocyty * patologie ultrastruktura MeSH
- heterochromatin * genetika ultrastruktura MeSH
- kostní dřeň MeSH
- kultivační techniky metody využití MeSH
- lidé MeSH
- mikrofotografie využití MeSH
- neutrofily patologie ultrastruktura MeSH
- prekurzorové buňky granulocytů ultrastruktura MeSH
- statistika jako téma MeSH
- struktury buněčného jádra ultrastruktura MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Early leukemic granulocytic and plasmacytic precursors were studied in vitro and in vivo to provide an information on the intranucleolar distribution of AgNORs (silver stained nucleolus organizer regions). In most of these cells AgNORs appeared as clusters of silver stained particles distributed in the whole nucleolar body. On the other hand, in some leukemic early granulocytic precursors, i.e., in myeloblasts and promyelocytes enlarged AgNORs were translocated in the nucleolar peripheral part. In addition, the number of translocated AgNORs at the nucleolar periphery was significantly smaller. Such translocation of a reduced number of AgNORs was easily produced by experimental aging, i.e., starving of cultured leukemic early granulocytic precursors (HL-60 and K562 cells) in vitro and seems to be reversible. Similar translocation of a reduced number of AgNORs was also produced by aging of leukemic plasmacytic precursors. Thus, the translocation of the reduced number of AgNORs to the nucleolar periphery in some blastic leukemic hematopoietic cells might be an useful marker of their aging at the single cell level. However, more studies in this direction are required in the future.
- MeSH
- barvení stříbrem MeSH
- buněčné jadérko metabolismus MeSH
- buněčný cyklus fyziologie MeSH
- buňky K562 MeSH
- buňky kostní dřeně metabolismus MeSH
- DNA nádorová metabolismus MeSH
- financování organizované MeSH
- granulocyty metabolismus ultrastruktura MeSH
- HL-60 buňky MeSH
- leukemie metabolismus MeSH
- lidé MeSH
- organizátor jadérka metabolismus MeSH
- plazmatické buňky metabolismus ultrastruktura MeSH
- RNA nádorová metabolismus MeSH
- stárnutí buněk fyziologie MeSH
- transport proteinů MeSH
- Check Tag
- lidé MeSH
- MeSH
- buněčné jadérko ultrastruktura MeSH
- finanční podpora výzkumu jako téma MeSH
- granulocyty ultrastruktura MeSH
- kostní dřeň cytologie MeSH
- lidé MeSH
- myelodysplastické syndromy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- buněčné dělení fyziologie MeSH
- buněčné jadérko * MeSH
- buňky kostní dřeně * fyziologie MeSH
- chronická myeloidní leukemie * patologie MeSH
- granulocyty * ultrastruktura MeSH
- hematopoéza * fyziologie MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- dopisy MeSH
- klinické zkoušky kontrolované MeSH
- klinické zkoušky MeSH
- práce podpořená grantem MeSH
