Effects of gold sodium thiomalate and tenidap sodium (CP‐66,248–2) on a model of macrophage differentiation using HL‐60 cells

McGuire Veterans Administration Medical Center, The Medical College of Virginia, Virginia Commonwealth University, Richmond, and Pfizer Central Research, Groton, Connecticut.
Arthritis & Rheumatology (Impact Factor: 7.76). 01/1990; 33(1):29 - 36. DOI: 10.1002/art.1780330104


We studied the effects of gold sodium thiomalate (GST) and a new antirheumatic drug, tenidap sodium ([Z]-5-chloro-2,3-dihydro-3-[hydroxy-2-thienylmethylene]-2-oxo-1H-indole-1-carboxamide, sodium salt), previously known as CP-66,248–2, in a model system of macrophage differentiation using a myelomonocytic cell line. HL-60 cells can be stimulated by vitamin D3 to differentiate along a monocytic pathway. Monocytic HL-60 cells express CD14 (Leu-M3), a macrophage surface marker, and develop the capacity to produce the second complement component (C2) in response to stimulation with cytokines such as γ-interferon. The effects of GST and tenidap sodium were compared with the effects of dexamethasone and a variety of nonsteroidal antiinflammatory drugs in this model system. We found that GST inhibited the capacity of HL-60 cells to produce C2 but did not inhibit the expression of CD14. Tenidap sodium inhibited C2 production as well as CD14 expression, and it partially reversed the decrease in 3H-thymidine incorporation by HL-60 cells, which accompanies monocytic differentiation. At concentrations that inhibited C2 production by HL-60 cells, tenidap sodium did not inhibit C2 production by monocytes. Neither dexamethasone nor the other nonsteroidal antiinflammatory drugs tested possessed these activities. Thus, both GST and tenidap inhibit markers of monocytic differentiation in HL-60 cells, and this activity may relate to their antirheumatic activities.

5 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: The reactions of methane with the gold complexes [Au(OH)]−, [Au(OCH3)4]−, [Au(O(CO)2O2]− and [Au(O2CH)2]+, [AuI(acac)], [AuIII(acac)2]+ (acac-acetylacetonato) were studied using the DFT/PBE method with the SBK basis set. High activation barriers were obtained for the electrophilic substitution in [Au(OH)]−, [Au(OCH3)4]−, [Au(O(CO)2O)2]-and [AuIII(acac)2]+ complexes, which excludes the possibility that these reactions might proceed under mild conditions. The reactions of the [Au(HCO2)2]+ and [AuI(acac)] complexes with methane have rather low energy barriers and proceed through the formation of an intermediate complex. The alternative mechanism of methane oxidation with a gold complex in the presence of oxygen is simulated.
    Baillière s Clinical Rheumatology 01/1991; 4(3):491-534. DOI:10.1016/S0950-3579(05)80005-6
  • [Show abstract] [Hide abstract]
    ABSTRACT: We studied the effect of tenidap sodium, a new antiinflammatory/antirheumatic drug (120 mg/day for 7 days), on eicosanoid production and neutrophil degranulation in patients with rheumatoid arthritis. Endogenous prostaglandin E2 levels and ex vivo production of leukotriene B4 (LTB4) were measured in synovial fluid samples obtained at baseline and 1 week later. We measured peripheral blood polymorphonuclear cell (PMN) degranulation following surface-bound IgG stimulation, a possible 5-lipoxygenase product–mediated event, by determining lactoferrin and elastase release into the culture fluid. We found decreased levels of endogenous prostaglandin E2 as measured by radioimmunoassay, and decreased ex vivo production of LTB4 by PMN as measured by high performance liquid chromatography, in synovial fluid samples from patients who took tenidap. Release of the granule proteins lactoferrin and elastase was decreased in PMN obtained from patients receiving tenidap, as well as in the PMN incubated in vitro with tenidap. Improvement in clinical measures paralleled the biochemical changes. The unique 5-lipoxygenase inhibitory property of tenidap, as measured by LTB4 production and degranulation, suggests that it may have clinical activity which differentiates it from nonsteroidal antiinflammatory drugs.
    Arthritis & Rheumatology 02/1991; 34(2):204 - 210. DOI:10.1002/art.1780340212 · 7.76 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have shown that the gold compounds, gold sodium thiomalate (GST) and auranofin (AUR), which are effective in the treatment of rheumatoid arthritis, inhibit functional activities of a variety of cells, but the biochemical basis of their effect is unknown. In the current studies, human T cell proliferation and interleukin 2 production by Jurkat cells were inhibited by GST or AUR at pharmacologically relevant concentrations. Because it has been documented that protein kinase C (PKC) is involved in T cell activation, the capacity of gold compounds to inhibit PKC partially purified from Jurkat cells was assayed in vitro. GST was found to inhibit PKC in a dose-dependent manner, but AUR caused no significant inhibition of PKC at pharmacologically relevant concentrations. The inhibitory effect of GST on PKC was abolished by 2-mercaptoethanol. To investigate the effect of GST on the regulation of PKC in vivo, the levels of PKC activity in Jurkat cells were examined. Cytosolic PKC activity decreased slowly in a concentration- and time-dependent manner as a result of incubation of Jurkat cells with GST. To ascertain whether GST inhibited PKC translocation and down-regulation, PKC activities associated with the membrane and cystosolic fractions were evaluated after phorbol myristate acetate (PMA) stimulation of GST incubated Jurkat cells. Translocation of PKC was markedly inhibited by pretreatment of Jurkat cells with GST for 3 d, but the capacity of PMA to down-regulate PKC activity in Jurkat cells was not altered by GST preincubation. The functional impact of GST-mediated downregulation of PKC in Jurkat cells was examined by analyzing PMA-stimulated phosphorylation of CD3. Although GST preincubated Jurkat cells exhibited an increased density of CD3, PMA-stimulated phosphorylation of the gamma chain of CD3 was markedly inhibited. Specificity for the inhibitory effect of GST on PKC was suggested by the finding that GST did not alter the mitogen-induced increases in inositol trisphosphate levels in Jurkat cells. Finally, the mechanism of the GST-induced inhibition of PKC was examined in detail, using purified PKC subspecies from rat brain. GST inhibited type II PKC more effectively than type III PKC, and also inhibited the enzymatic activity of the isolated catalytic fragment of PKC. The inhibitory effect of GST on PKC activity could not be explained by competition with phospholipid or nonspecific interference with the substrate. These data suggest that the immunomodulatory effects of GST may result from its capacity to inhibit PKC activity.
    Journal of Clinical Investigation 07/1992; 89(6):1839-48. DOI:10.1172/JCI115788 · 13.22 Impact Factor
Show more