OBJECTIVE Diabetic patients have elevated blood levels of interleukin-6 (IL-6), which is known to increase inflammation and the development of vascular disease and atherosclerosis. This study examined the hypothesis that ketosis increases the circulating levels of IL-6 in type 1 diabetic patients as well as the secretion of IL-6 in vitro in a cell culture model using U937 monocytes. RESEARCH ...

Several recent studies have suggested a role for 1,25-dihydroxyvitamin D3 (calcitriol) in myeloid differentiation. We have examined the effects of calcitriol on the U937 monoblast cell line and found that calcitriol, at near physiologic concentrations, is a potent inhibitor of U937 growth. Moreover, calcitriol induces differentiation to a monocyte-macrophage phenotype marked by enhanced alpha-n...

To analyze the activity of the CDllc promoter during myeloid differentiation without the limitations of transient expression systems, we have stably transfected the myeloid U937 cell line with the pCDllC36l-Luc plasmid, in which the expression of the firefly luciferase cDNA is driven by the CDllc promoter region -361/+43, previously shown to confer myeloid specificity to reporter genes. The sta...

In this study, we investigated the functional role of Akt and c-jun-NH(2)-kinase (JNK) signaling cascades in apigenin-induced apoptosis in U937 human leukemia cells and anti-leukemic activity of apigenin in vivo. Apigenin induced apoptosis by inactivation of Akt with a concomitant activation of JNK, Mcl-1 and Bcl-2 downregulation, cytochrome c release from mitochondria, and activation of caspas...

Oxazaphosphorines belong to a group of alkylating agents. Mafosfamide cyclohexylamine salt (D-17272), 4-hydro-peroxy-cyclophosphamide (D-18864) and glufosfamide (D-19575, beta-D-glucose-isophosphoramide mustard) are new generation oxazaphosphorines. The objective of the present study was to compare the cytotoxic action of these oxazaphosphorine compounds against human histiocytic lymphoma U937 ...

The rates of internalization and uncoating of 32P-labelled human immunodeficiency virus (HIV) in the human T lymphoid cell line CEM are consonant with a receptor-mediated endocytosis mechanism of entry. This interpretation was affirmed by electron microscopic observation of virions within endosomes. Virus binding and infectivity were inhibited to the same extent by pretreatment with OKT4A antib...

The immunomodulatory hormone 1.25-dihydroxyvitamin D3 (1,25-(OH)2D3) has been shown to suppress T-cell proliferation and interleukin-2 synthesis as well as 6-cell immunoglobulin synthesis, while stimulating many macrophage functions. We have previously shown increased synthesis of interleukin-1f3 in lipopolysaccharide (LPS)-stimulated U937 cells after pretreatment with 10 nmol/L 1,25-(0H)2D~. W...

Evodiamine is one of the major bioactive compounds that have been isolated and purified from the fruit of Evodiae fructus. Evodiamine exhibits antitumor activities against the human tumor cells, including multidrug-resistant tumor cells. However, the molecular mechanism involved in cell death induced by evodiamine treatment remains poorly understood. In the present study, we showed that evodiam...

Copper (Cu) deficiency suppresses macrophage activities in animals and humans. Our previous studies indicated that the induction of Cu deficiency in differentiated U937 monocytic cells impairs respiratory burst and bactericidal activities and lipopolysaccharide-mediated secretion of inflammatory mediators. The current investigation examined the roles of Cu in the monocytic differentiation proce...

Plant polyphenols have been shown to enhance the differentiation of acute myeloid leukemia (AML) cells induced by the hormonal form of vitamin D(3) (1α,25-dihydroxyvitamin D(3); 1,25D). However, how these agents modulate 1,25D effects in different subtypes of AML cells remains poorly understood. Here, we show that both carnosic acid (CA) and silibinin (SIL) synergistically enhancd 1,25D-induced...