[Show abstract][Hide abstract] ABSTRACT: Immunologic derangements in rheumatoid arthritis (RA) patients likely contribute to premature atherosclerotic cardiovascular disease (CVD). Traditional CVD risk factors do not reliably identify at-risk RA patients, probably because disease-associated mechanisms are not taken into account. The purpose of this study was to determine whether plasma from subjects with RA exhibits atheroma-promoting properties leading to disruption of cholesterol homeostasis in human monocytes/macrophages. Twenty-one healthy controls (HC) and 22 RA patients were enrolled in an IRB approved study at Winthrop University Hospital. Naïve THP-1 macrophages were exposed to plasma from each HC and RA patient. Following incubation, RNA and protein were isolated. QRT-PCR and Western blotting techniques were then used to measure expression of proteins responsible for cholesterol efflux (ATP binding cassette transporter (ABC)A1, ABCG1, 27-hydroxylase) and cholesterol uptake (CD36, ScR-A1, lectin oxidized low density lipoprotein receptor (LOX)-1, CXCL16). To confirm the pro-atherogenic effects of RA plasma on macrophages, foam cell formation was quantified. Results showed that RA plasma downregulates cholesterol efflux proteins and upregulates scavenger receptors CD36, LOX1 and CXCL16. These pro-atherogenic changes in gene expression in the presence of RA plasma are associated with augmented lipid accumulation and foam cell formation by THP-1 macrophages. RA plasma induces macrophage cholesterol overload. Demonstration of disrupted cholesterol homeostasis mediated by RA plasma provides further evidence of the involvement of the immune system in atherogenesis. Our data suggest that chronic exposure to RA plasma adversely affects the capacity of monocytes/macrophages in the arterial wall to metabolize cholesterol and maintain lipid homeostasis, thereby contributing to the development of premature atherosclerosis.
Full-text · Article · Sep 2013 · Experimental Biology and Medicine
[Show abstract][Hide abstract] ABSTRACT: Atherosclerotic cardiovascular disease (ASCVD) contributes to morbidity and mortality in systemic lupus erythematosus (SLE). Immunologic derangements may disrupt cholesterol balance in vessel wall monocytes/macrophages and endothelium. We determined whether lupus plasma impacts expression of cholesterol 27-hydroxylase, an anti-atherogenic cholesterol-degrading enzyme that promotes cellular cholesterol efflux, in THP-1 human monocytes and primary human aortic endothelial cells (HAEC). THP-1 monocytes and HAEC were incubated in medium containing SLE patient plasma or apparently healthy control human plasma (CHP). SLE plasma decreased 27-hydroxylase message in THP-1 monocytes by 47 +/- 8% (p < 0.008) and in HAEC by 51 +/- 5.5% (n = 5, p < 0.001). THP-1 macrophages were incubated in 25% lupus plasma or CHP and cholesterol-loaded (50 microg ml(-1) acetylated low density lipoprotein). Lupus plasma more than doubled macrophage foam cell transformation (74 +/- 3% vs. 35 +/- 3% for CHP, n = 3, p < 0.001). Impaired cholesterol homeostasis in SLE provides further evidence of immune involvement in atherogenesis. Strategies to inhibit or reverse arterial cholesterol accumulation may benefit SLE patients.
No preview · Article · Jun 2009 · Rheumatology International
[Show abstract][Hide abstract] ABSTRACT: We present the first reported case of a patient with dermatomyositis found to have primary gastric melanoma. The possibility of primary gastric melanoma occurring before, concurrently or after the onset of dermatomyositis is the subject of this case report.
No preview · Article · Oct 2008 · The American Journal of the Medical Sciences
[Show abstract][Hide abstract] ABSTRACT: Human neutrophils express both activating and inhibitory Fcgamma receptors (FcgammaR), and their relative expression determines the inflammatory response to immune complexes. Tumor necrosis factor alpha (TNFalpha) up-regulates the expression of stimulatory FcgammaRIIa on neutrophils in vitro, and amplifies immune complex-induced activation of neutrophils in vivo. This study was undertaken to determine whether TNFalpha blockade in patients with rheumatoid arthritis (RA) alters the balance of activating FcgammaR and inhibitory FcgammaR and thereby decreases inflammation.
We used fluorescence-activated cell sorting and Western blotting to examine FcgammaR expression on neutrophils in 24 patients with RA, preceding their first infusion of infliximab and immediately prior to >or=3 subsequent infusions.
In 13 of 24 patients (54.2%), there was a decrease in the expression of the predominant activating FcgammaR, FcgammaRIIa, after treatment with infliximab, an effect that persisted over >or=3 months of treatment. Although prior to initiation of infliximab therapy the inhibitory FcgammaR, FcgammaRIIb, was undetectable in neutrophils from 23 of 24 patients with RA, FcgammaRIIb protein was detected by Western blotting in 9 patients (37.5%) at the time of the third infliximab infusion. The induction of inhibitory FcgammaRIIb was always associated with decreased levels of FcgammaRIIa, and improvement following infliximab therapy, measured using the Health Assessment Questionnaire, was significantly associated with down-regulation of FcgammaRIIa.
Our findings indicate that TNFalpha inhibition may reduce inflammation in patients with RA by restoring the balance of activating and inhibitory FcgammaR and thereby raising the threshold for immune complex-mediated activation of neutrophils.
Full-text · Article · Feb 2008 · Arthritis & Rheumatology
[Show abstract][Hide abstract] ABSTRACT: Activation of neutrophils by the interaction of immune complexes with Fc gamma receptors (FcgammaR) is amplified in tumor necrosis factor-alpha (TNFalpha)-primed cells, whereas interleukin-10 (IL-10) has been reported to suppress cytokine-mediated neutrophil activation. We examined whether the expression and function of FcgammaR in human neutrophils is modulated by TNFalpha and IL-10 in vitro, and whether FcgammaRIIa expression is altered following treatment with the TNFalpha inhibitor infliximab in rheumatoid arthritis (RA) patients in vivo. TNFalpha treatment induced upregulation of expression and function of the major activating Fc receptor, FcgammaRIIa, in neutrophils from healthy donors. Unexpectedly, treatment with IL-10 led to gain of FcgammaRIIa function in TNFalpha-primed neutrophils. In neutrophils from RA patients initiating infliximab therapy and followed longitudinally through consecutive treatments, FcgammaRIIa protein decreased during the course of TNFalpha blockade, indicating that FcgammaRIIa is a target of TNFalpha modulation in human neutrophils in vivo.
No preview · Article · Nov 2005 · Clinical Immunology