The supply of red blood cells (RBCs) is not sufficient in many developing countries or in developed countries for patients who need chronic transfusion from best-matched donors. Ex vivo expansion and maturation of human erythroid precursor cells (erythroblasts) could represent a potential solution. Proliferating erythroblasts can be expanded from human umbilical cord blood mononuclear cells (CB MNCs) ex vivo for 10^6-10^7 fold (in ~50 days) before undergoing senescence. Here, we report that ectopic expression of three to four genetic factors that have been used for iPS cell derivation enables CB-derived erythroblasts to undergo extended ex vivo expansion (10^51 fold in ~9 months) in a defined suspension culture condition without change of cell identity or function. These vastly expanding erythroblasts maintain homogeneously immature erythroblast phenotypes, a normal diploid karyotype and dependence on specific combination of cytokines and hormone for survival and proliferation throughout the continuous expansion period. When switched to a culture condition for terminal maturation, these immortalized erythroblasts gradually exit cell cycle, decrease cell size, accumulate hemoglobin, condense nuclei and eventually give rise to enucleated hemoglobin-containing erythrocytes. Our result may ultimately lead to the development of unlimited sources of cultured RBCs for optimally-matched or personalized transfusion medicine.
Extensive ex vivo expansion of functional human erythroid precursors established from umbilical cord blood cells by defined factors.
Specimen part
View SamplesFOXO1 is highly expressed in normal B cells and in most types of non-Hodgkinl lymphoma. In Hodgkin and Reed-Sternberg cells of classical Hodgkin lymphoma(cHL) expression of FOXO1 is low or absent. We overexpressed constitutively active mutant of FOXO1 fused in frame with estrogen receptor ligand-binding domain (FOXO1(3A)ER), which can be activated by 4-Hydroxytamoxifen (4-OHT), in cHL cell lines KM-H2 and L428. Activation of the FOXO1 with 4-OHT resulted in inhibition of proliferation and apoptosis. Using gene-expression array we found that FOXO1 activates transcription of known and potential tumor suppressor genes: CDKN1B, PMAIP1, BCL2L11, TNFSF10, FBXO32, CBLB). Of note, FOXO1 repressed transcription of several cytokines and cytokine receptors, which are known tobe involved in pathogenesis of cHL (e.g. CCL5, CXCR5, TNFRSF8). Taken togather our data indicate important role of FOXO1 repression in pathogenesis of cHL.
FOXO1 repression contributes to block of plasma cell differentiation in classical Hodgkin lymphoma.
Specimen part, Cell line, Treatment
View SamplesRationale: Damage to airway epithelium is followed by deposition of extracellular matrix (ECM) and migration of adjacent epithelial cells. We have shown that epithelial cells from asthmatic children fail to heal a wound in vitro. Objectives: To determine whether dysregulated ECM production by the epithelium plays a role in aberrant repair in asthma. Methods: Airway epithelial cells (AEC) from children with asthma (n=36), healthy atopic (n=23) and healthy non-atopic controls (n=53) were investigated by microarray, gene expression and silencing, transcript regulation analysis and ability to close mechanical wounds. Results: Wound repair of AEC from healthy and atopic children were not significantly different and were both faster than AEC from asthmatics. Microarray analysis revealed differential expression of multiple gene sets associated with repair and remodeling in asthmatic AEC. Fibronectin (FN) was the only ECM component whose expression was significantly lower in asthmatic AEC. Expression differences were verified by qPCR and ELISA, and reduced FN expression persisted in asthmatic cells over passage. Silencing of FN expression in non-asthmatic AEC inhibited wound repair, while addition of FN to asthmatic AEC restored reparative capacity. Asthmatic AEC failed to synthesize FN in response to wounding or cytokine/growth factor stimulation. Exposure to 5, 2deoxyazacytidine had no effect on FN expression and subsequent analysis of the FN promoter did not show evidence of DNA methylation. Conclusions: These data show that the reduced capacity of asthmatic epithelial cells to secrete FN is an important contributor to the dysregulated AEC repair observed in these cells.
Decreased fibronectin production significantly contributes to dysregulated repair of asthmatic epithelium.
Specimen part
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