Abstract
Objective. The aim of this study was to examine the structural characterization of erythroid and megakaryocytic cell differentiation in Friend erythroleukemic cells using spectral imaging and electron microscopy. Materials and Methods. Two variants of Friend erythroleukemia cells were treated with hex-amethylene bisacetamide (HMBA) to induce differentiation: 1) MEL, which exhibit the normal phenotype and are susceptible to differentiation; and 2) the resistant R1 cells. The cells were analyzed by spectral imaging along with transmission and scanning electron microscopy. The expression of cell cycle regulatory proteins was analyzed by Western blotting. Results. Spectral imaging of HMBA-treated MEL and R1 cells stained by May-Grünwald-Giemsa and subjected to spectral similarity mapping revealed five morphologic cell types: proerythroblast-like cells, normoblast-like cells, reticulocyte-like cells, megakaryocytes, and apoptotic cells. In MEL cells, both megakaryocytic differentiation characterized by nuclear lobes and erythroid differentiation characterized by accumulation of hemoglobin were detected; R1 cells were not committed to terminal differentiation. HMBA-induced cell cycle arrest at G1 affected the expression of regulatory proteins in a similar manner in both types of cells. Expression of cyclin-dependent kinase 4 decreased and expression of p21WAF1 increased. The level of the underphosphorylated form of phosphorylated retinoblastoma protein increased, inducing a decrease in the level of c-myc. In addition, we detected a decrease in the expression of the anti-apoptotic regulator, Bcl-2, and an increased expression of the pro-apoptotic regulator, Bax. Conclusions. Spectral imaging provides new insight for the morphologic characterization of erythroid and megakaryocytic cell differentiation as well as apoptosis. Image analysis was well correlated to cell cycle arrest and the expression of regulatory proteins.
| Original language | English |
|---|---|
| Pages (from-to) | 563-571 |
| Number of pages | 9 |
| Journal | Experimental Hematology |
| Volume | 29 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2001 |
Bibliographical note
Funding Information:This study was supported by a grant from Applied Spectral Imaging, Migdal HaEmek, Israel to Z.M. We gratefully thank Ms. Judith Hanania for help in editing the manuscript and for technical assistance in TEM experiments. We gratefully acknowledge the technical assistance of Mr. Jacob Langsam in SEM experiments.
Funding
This study was supported by a grant from Applied Spectral Imaging, Migdal HaEmek, Israel to Z.M. We gratefully thank Ms. Judith Hanania for help in editing the manuscript and for technical assistance in TEM experiments. We gratefully acknowledge the technical assistance of Mr. Jacob Langsam in SEM experiments.
| Funders | Funder number |
|---|---|
| Applied Spectral Imaging | |
| Migdal HaEmek |
