Increase in serum triglyceride was associated with coronary plaque vulnerability in a patient with rheumatoid arthritis.

Rates of morbidity and mortality from cardiovascular disease are high in patients with rheumatoid arthritis (RA); however, the mechanisms and biomarkers that reflect coronary plaque vulnerability have not yet been established. We present a case of acute coronary syndrome (ACS) presumably caused by exacerbation of chronic inflammation of RA, in which an abrupt increase in serum triglyceride was seen on the day of onset of ACS but not during effort angina. This case suggests that RA patients with an abrupt increase in triglyceride need intensive care including anti-platelet and statin therapy for the prevention of coronary plaque rupture. .

Androgen receptor promotes sex-independent angiogenesis in response to ischemia and is required for activation of vascular endothelial growth factor receptor signaling.

BACKGROUND: Hypoandrogenemia is associated with an increased risk of ischemic diseases. Because actions of androgens are exerted through androgen receptor (AR) activation, we studied hind-limb ischemia in AR knockout mice to elucidate the role of AR in response to ischemia. METHODS AND RESULTS: Both male and female AR knockout mice exhibited impaired blood flow recovery, more cellular apoptosis, and a higher incidence of autoamputation after ischemia. In ex vivo and in vivo angiogenesis studies, AR-deficient vascular endothelial cells showed reduced angiogenic capability. In ischemic limbs of AR knockout mice, reductions in the phosphorylation of the Akt protein kinase and endothelial nitric oxide synthase were observed despite a robust increase in hypoxia-inducible factor 1α and vascular endothelial cell growth factor (VEGF) gene expression. In in vitro studies, siRNA-mediated ablation of AR in vascular endothelial cells blunted VEGF-stimulated phosphorylation of Akt and endothelial nitric oxide synthase. Immunoprecipitation experiments documented an association between AR and kinase insert domain protein receptor that promoted the recruitment of downstream signaling components. CONCLUSIONS: These results document a physiological role of AR in sex-independent angiogenic potency and provide evidence of novel cross-talk between the androgen/AR signaling and VEGF/kinase insert domain protein receptor signaling pathways.

Activation of peroxisome proliferator-activated receptor α in megakaryocytes reduces platelet-derived growth factor-BB in platelets.

AIM: Platelet-derived growth factor (PDGF)-BB plays a crucial role in atherosclerosis and vascular remodeling by promoting the migration and proliferation of vascular smooth muscle cells. The objective of this study was to clarify the pleiotropic effect of peroxisome proliferator-activated receptor α (PPARα) activators on PDGF-BB expression in megakaryocytes and platelets. METHODS AND RESULTS: The expression of PPARα in a human erythroleukemia (HEL) cells was clearly detected by reverse transcriptase-PCR and immunofluorescence microscopy. The expression level of PPARα in HEL cells was unchanged regardless of differentiation into megakaryocytic cells by treatment with phorbol 12-myristate 13 acetate (TPA). The TPA-induced expression of PDGF-B mRNA and PDGF-BB protein levels in culture media was significantly decreased by treatment with PPARα activators, Wy14643 and fenofibric acid, in a dose-dependent manner. PDGF-BB expression induced by inflammatory cytokines, including interleukin-1ß or interleukin-6, was also significantly suppressed by treatment with PPARα activators. Immunohistochemistry of human bone marrow showed the expression of PPARα in both the nucleus and cytoplasm of megakaryocytes. In addition, PDGF-BB levels in platelets were significantly decreased from 1,800±870 to 1,470±840 pg/10(5) platelets (mean±SD, p<0.05) by treatment with 300 mg fenofibrate once daily for 4 weeks in 13 patients with dyslipidemia. CONCLUSIONS: Activation of PPARα in megakaryocytes reduces PDGF-BB expression in platelets. PPARα activators may exert vasculo-protective action through suppression of PDGF-BB production in a megakaryocyte/platelet pathway.

High plasma aldosterone concentration is a novel risk factor of cognitive impairment in patients with hypertension.

Cognitive impairment leading to dementia is associated with high prevalence of hypertension, decreased quality of life and poor prognosis. Aldosterone is known as a risk factor for cardiovascular and cerebrovascular diseases. In addition, mineral corticoid receptors are abundantly expressed in the hippocampus, which plays a pivotal role in cognitive function; however, it has not been determined whether plasma aldosterone level is associated with cognitive impairment in patients with hypertension. We enrolled 68 patients with essential hypertension and assessed their cardiovascular risk factors, including blood pressure, hyperlipidemia, diabetes mellitus, obesity, smoking, history of cerebral infarction, renal function, parameters of inflammation, oxidative stress and nitric oxide bioavailability, a parameter of cerebral blood flow and carotid plaque by ultrasound examination, plasma renin activity and plasma aldosterone concentration (PAC). The mini-mental state examination (MMSE) was used to evaluate cognitive function. The relevance of cardiovascular risk factors and MMSE score was statistically evaluated. Multiple regression analysis showed that age (P < 0.01), PAC (P < 0.01) and history of cerebral infarction (P < 0.05) were inversely and independently associated with MMSE score. Mineral corticoid receptor antagonists, including spironolactone and eplerenone, increased MMSE score in seven patients with hypertension, but not in the controls. In conclusion, increased PAC is associated with impaired cognitive function and mineral corticoid receptor blockade may protect against not only cardiovascular mortality, but also cognitive impairment in patients with hypertension.

Ezetimibe ameliorates metabolic disorders and microalbuminuria in patients with hypercholesterolemia.

AIM: Ezetimibe, an inhibitor of Niemann-Pick C1-like 1 protein, has been shown to reduce the intestinal absorption of cholesterol. We investigated whether it also has beneficial effects on metabolic disorder and/or renal insufficiency in patients with hypercholesterolemia. METHODS: Ezetimibe was administered to 38 Japanese patients with hypercholesterolemia to obtain appropriate low-density lipoprotein cholesterol (LDL-chol) levels. Age- and sex-matched patients with hypercholesterolemia (n=38) were the controls. We evaluated the effects of ezetimibe before and 4 to 8 weeks after ezetimibe treatment. RESULTS: Ezetimibe significantly decreased LDL-chol levels and metabolic syndrome-related factors, including body weight, waist circumference, blood pressure; homeostasis model assessment insulin resistance (HOMA-IR), and urinary albumin excretion, were significantly reduced. In addition, it decreased the level of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor (TNF)-alpha, the urinary excretion of 8-hydroxy-2'-deoxyguanosine, a parameter of oxidative stress, and increased the urinary excretion of nitrate and nitrite (NOx). In the controls we observed no such changes. Excepting the decrease in the serum TNF-alpha level, the effects of ezetimibe were not correlated with decreased LDL-chol levels. CONCLUSION: Ezetimibe ameliorated the status of metabolic syndrome and microalbuminuria, reduced inflammation and oxidative stress, and increased nitric oxide bioavailability in a LDL-chol reduction-dependent and -independent manner.