Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.5 (neuropathy target esterase)
 1,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eosinophils derived from HL-60 cells share many of the abnormalities of granule histochemistry and morphology frequently seen in eosinophils of patients with certain malignancies, especially those seen in acute myelomonocytic leukemia with abnormal eosinophils (FAB class M4eo). In order to understand the pathogenesis of these abnormalities, four enzymes, characteristic of the eosinophil, were studied in HL-60 promyelocytic leukemia cells at various stages of eosinophilic differentiation. Using biochemical and ultrahistochemical techniques, the following differences from normal eosinophil development were demonstrated. First, both myeloperoxidase and eosinophil peroxidase coexisted in the population of maturing HL-60 eosinophils. Second, the granules formed from the condensation of material in vacuoles which were derived from dilated segments of the endoplasmic reticulum; the role of the Golgi apparatus in processing of peroxidase appeared minimal. Third, low levels of lysophospholipase and arylsulfatase were present in the cells compared to normal eosinophils. Finally, crystallizations resembling precursor structures of Auer rods appeared in the granules of about 5% of the cells. These findings suggest that several disorders of the control of protein synthesis and processing exist in HL-60 eosinophils which may be responsible for the abnormal granule morphology and histochemistry.
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PMID:Synthesis of eosinophil-associated enzymes in HL-60 promyelocytic leukemia cells. 301 41

HL-60 promyelocytic leukemia cells differentiated to eosinophils and eosinophilic precursors when cultured under mildly alkaline conditions (pH 7.6-7.8) for 7 d without refeeding. New cytoplasmic granules appeared blue in the least mature cells and red in the most mature cells when stained with Wright-Giemsa. The granules also stained with Luxol-fast-blue, a characteristic of eosinophil granules. Furthermore, most cells contained the eosinophil major basic protein (MBP); the Charcot-Leyden Crystal (CLC) protein (lysophospholipase), eosinophil peroxidase, acid phosphatase, and arylsulfatase were also detected in a portion of these cells. The eosinophil major basic protein was found in a high proportion of undifferentiated cells, and thus may be constituitively produced. By examining finely banded chromosomes, translocation break points were demonstrated at q22 on one chromosome 16 and at q23 on the other homologue; abnormalities in this region of the long arm of 16 are a characteristic finding in the recently described syndrome of acute myelomonocytic leukemia (AMMoL) with abnormal bone marrow eosinophils. In common with the bone marrow eosinophils in these patients, the HL-60 eosinophil granules contained chloroacetate esterase and periodic-acid Schiff (PAS) reactive material; crystalloid inclusions were rare. Therefore, the HL-60 cell line appears to be an in vitro model for eosinophilopoiesis and may be specially suited for the study of the abnormal eosinophils seen in certain malignant conditions.
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PMID:Eosinophilic differentiation of the human promyelocytic leukemia cell line, HL-60. 658 34

The Charcot-Leyden crystal (CLC) protein is a lysophospholipase expressed exclusively by eosinophils and basophils. During eosinophilic differentiation of eosinophil-committed cell lines, CLC steady state mRNA levels increase significantly. This increased expression is transcriptionally regulated during butyrate induction of an eosinophilic subline (C15) of the promyelocytic leukemia cell line HL-60, as shown by nuclear run-on assays. The transcriptional start site of the CLC gene was identified 43 bp upstream of the 5' end of the longest available cDNA sequence. The gene encoding CLC protein was cloned from a chromosome 19-specific library and a fragment overlapping the transcriptional start site was isolated and sequenced. Plasmid constructs (in the pXP2 luciferase expression vector) containing 411 and 292 bp of genomic sequence upstream of the CLC transcriptional start site directed reporter gene expression in transient transfections of HL-60-C15 cells, as well as other myeloid (U937) and nonmyeloid (HeLa and RPMI 8402) cell lines. However, the differential expression of the two CLC promoter constructs in these cell lines suggests that the -292 to -411 bp region of the promoter may confer some specificity for expression in the eosinophil lineage. The CLC promoter sequence contains two consensus GATA binding sites, a purine-rich sequence that presents potential binding sites for PU.1, a member of the ets family of genes, as well as sequences described in other myeloid-specific promoters. This is the first demonstration of a functional eosinophil promoter that could serve as a model for identifying DNA elements and trans-activating factors that regulate gene expression during the commitment and differentiation of the eosinophil lineage.
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PMID:Human eosinophil Charcot-Leyden crystal protein: cloning and characterization of a lysophospholipase gene promoter. 840 Feb 37