Treatments with tamoxifen and an antiestradiol antibody have beneficial effects on experimental SLE via cytokine modulation

Emerging minimal-change nephrotic syndrome in a patient with chronic mesangial proliferative lupus nephritis

A 41-year-old Japanese woman with a 25-year history of systemic lupus erythematosus was admitted because of abrupt onset of nephrotic syndrome and acute renal failure. Renal biopsy specimen showed only mild mesangial proliferative glomerulonephritis associated with mesangial deposition of immunoglobulins/complements. No significant immune deposits were found in the glomerular capillary walls, but mild foot process effacement was observed on electron microscopy. Further, two-month corticosteroid therapy improved her massive proteinuria and renal dysfunction, indicating that this patient showed minimal-change nephropathy superimposed on mesangial proliferative lupus nephritis.

Interactions of prednisolone and other immunosuppressants used in dual treatment of systemic lupus erythematosus in lymphocyte proliferation assays

Systemic lupus erythematosus is an autoimmune disease primarily affecting women. Currently, systemic lupus erythematosus therapy is suboptimal due to adverse effects of immunosuppressants, particularly corticosteroids. This study determines the single effects of prednisolone, dehydroepiandrosterone, bromocriptine, tamoxifen, mycophenolic acid, 2-chloro-2'-deoxyadenosine, azathioprine, and chloroquine on lectin-stimulated proliferation of human T lymphocytes, as well as determining whether there are interactions in the joint effects of prednisolone and these agents. The T lymphocytes from the whole blood of 10 middle-aged women were stimulated by phytohemagglutinin and cultured with varying drug concentrations. The Hill function was used to evaluate single-drug response data. Isobolograms were constructed to qualitatively analyze interactions. Parametric analysis based on competitive and noncompetitive interaction models was further applied to quantify the joint interactions and predict steroid-sparing potential. The surface interaction parameter (psi) estimated from parametric analysis was in concordance with isobolographic inspection for all interactions studied. All interactions favored the noncompetitive model. Results suggest that dehydroepiandrosterone is additive in its effect with prednisolone, whereas tamoxifen interacts synergistically, both providing steroid-sparing effects. Novel immuno-suppressants such as mycophenolic acid may still provide added pharmacologic benefit during therapy despite a slight antagonistic interaction with prednisolone. These studies help rationalize actual or potential use of other drugs with prednisolone in the treatment of systemic lupus erythematosus.

Sex hormones and systemic lupus erythematosus

Lupus is one disease in which sex hormones and gender are quite important. Studies of autoimmune diseases like lupus have made the hormone connection more important and increased our overall understanding of the sexual dimorphism of the immune system. It is clear that some fundamental biologic mechanism is at work here and that only knowledge of the molecular mechanisms behind the action of the hormones can help us to understand the gender preference in this illness. Hormones may be potent regulators of cytokine levels and, consequently, disease activity.

Apoptosis and tumorigenesis in human cholangiocarcinoma cells. Involvement of Fas/APO-1 (CD95) and calmodulin

We have previously demonstrated that tamoxifen inhibits the growth of human cholangiocarcinoma cells in culture and inhibits tumor growth when cells are injected into nude mice. However, the mechanism of action of tamoxifen remains unknown. Here we demonstrate that tamoxifen and trifluoperazine, both potent calmodulin antagonists, induce apoptosis in vitro, probably acting via the Fas system, in human cholangiocarcinoma cells. Human cholangiocarcinoma cell lines heterogeneously express Fas antigen on their surface. Fas-negative and Fas-positive surface-expressing cells were isolated, cloned, and cultured. Fas antibody, tamoxifen, and trifluoperazine induced dose-dependent apoptosis only in Fas-positive cells; Fas-negative cells were unaffected. Furthermore, apoptosis induced by tamoxifen in Fas-positive cells was blocked by an inhibitory Fas antibody. Tamoxifen was not acting through an anti-estrogenic mechanism, because neither Fas-negative nor Fas-positive cells expressed estrogen receptors and the pure anti-estrogen compound, ICI 182780, did not induce apoptosis in either cell line. Fas-negative cells, but not Fas-positive cells, were able to produce tumors when subcutaneously injected into nude mice. These findings suggest Fas may be a candidate oncogene involved in the pathogenesis of cholangiocarcinoma. Furthermore, the similarity between the pro-apoptotic effects of tamoxifen and trifluoperazine support an underlying molecular mechanism for Fas-mediated apoptosis that involves calmodulin.