Proteoglycan synthesis in human erythroleukaemia (HEL) cells

Abstract

Synthesis of sulphated proteoglycans was compared in human erythroleukaemia (HEL) cells grown under control conditions and under stimulation by dimethyl sulphoxide (DMSO) and phorbol 12-myristate 13-acetate (PMA). Synthesis of [35S]sulphate-labelled proteoglycans by DMSO-treated cells was decreased by about 35% relative to controls, but synthesis of proteoglycans by PMA-treated cells increased 3-4-fold. Control and DMSO-treated cells secreted 65% of the newly synthesized proteoglycans, but PMA-treated cells secreted more than 90%. Sepharose CL-6B chromatography and SDS/PAGE suggested the presence of several proteoglycans in the cells and culture medium. The PMA-treated cells synthesized a low-Mr proteoglycan (Kav. 0.3( that was not present in controls and DMSO-treated cultures. The proteoglycans of the cells and medium from control, DMSO-treated and PMA-treated cultures could be separated into three fractions by octyl-Sepharose chromatography. The proteoglycans were resistant to trypsin but were degraded by Pronase and papain to fragments similar in size to the NaOH/NaBH4-generated glycosaminoglycans. The average chain length of the glycosaminoglycans (Kav. 0.20 on Sepharose CL-6B for controls) was decreased by DMSO (Kav. 0.25) and by PMA (Kav. 0.30-0.38). Chondroitin ABC lyase digestion of the proteoglycans from the medium of the control cultures produced two core proteins at Mr 31,000 and 36,000. The DMSO medium proteoglycans had only the 31,000-Mr core protein, and the PMA culture medium proteoglycans had core proteins of Mr 27,000, 31,000 and 36,000. Changes in synthesis of proteoglycans induced by DMSO or PMA may have relevance for the maturation of haematopoietic cells.

Serglycin Constitutively Secreted by Myeloma Plasma Cells Is a Potent Inhibitor of Bone Mineralization in Vitro

“…Serglycin is secreted constitutively by various cell types including three hematopoietic tumor cell lines, which were found to secrete 55-70% of their serglycin amounts under control conditions and to totally release serglycin when stimulated by phorbol myristate acetate (7,8). Serglycin is suggested to be an important molecule for the packaging of biologically active molecules such as proteases, cytokines, and growth factors.…”

“…It is packaged into secretory granules or vesicles in platelets, mast cells, neutrophils and other leukocytes and is secreted upon activation (3). In other cell types such as lymphocytes and hematopoietic tumor cells (7)(8)(9)(10)(11), endothelial cells (4), and uterine decidua (12) it is constitutively secreted along with granule proteins. Serglycin may contain chondroitin sulfate (CS) or heparin chains.…”

“…Serglycin may contain chondroitin sulfate (CS) or heparin chains. In most blood cells serglycin bears CS chains, with the exception of connective tissue mast cells, where heparin chains are attached to the core protein (3,4,7,8,13,14).…”

DNase I Hypersensitivity Patterns of the Serglycin Proteoglycan Gene in Resting and Phorbol 12-Myristate 13-Acetate-stimulated Human Erythroleukemia (HEL), CHRF 288-11, and HL-60 Cells Compared with Neutrophils and Human Umbilical Vein Endothelial Cells

“…The serglycin proteoglycan is synthesized by normal hematopoietic cells, including megakaryocytes (6,7), granulocytes (eosinophils, basophils, and neutrophils), macrophages, lymphocytes, and mast cells (3, 4, 8 -10). It is also synthesized by a large number of hematopoietic tumor cells (11)(12)(13)(14), human umbilical vein endothelial cells (HUVEC) (15), and uterine decidua in mid-stage pregnant mice (16). Serglycin is likely to be important in packaging of proteins in secretory granules and in granule assembly and secretion.…”

Metastatic Calcinosis Circumscripta Treated with an Oral Charcoal Absorbent in a Dog.

“…The occurrence of this disease has been reported in connection with the administration of a commercially available medroxy-progesterone acetate and the use of a polydioxanone suture with percutaneous penetration of calcium chloride [5,7,17]. Dystrophic calcinosis occurs following tissue damage.…”