Interleukin-6 and cardiovascular diseases

Inflammatory cytokines are important for both cardiovascular scientists and practicing clinicians. Interleukin-6 (IL-6) has been emphasized by reports of elevated circulating as well as intracardiac IL-6 levels in patients with congestive heart failure (CHF). IL-6 may contribute to the progression of myocardial damage and dysfunction in chronic heart failure syndrome resulting from different causes. As the cause of CHF in cardiomyopathy, myocarditis, allograft rejection, and left ventricular assist device (LVADs) conditions, circulating IL-6 levels are associated with the severity of left ventricular dysfunction, and are also strong predictors of subsequent clinical outcomes. Continuous and excessive production of IL-6 promotes myocardial injury by breaking down both cytokine networks and viral clearance under viral myocarditis. Although IL-6 is likely important in the process of viral antigen presentation, early activation of immune responses and attenuation of viral replication also appear to be significant in an animal model of viral myocarditis. IL-6 can cause cardiac hypertrophy through the IL-6 signal transducing receptor component, glycoprotein 130. There are several interesting cases of cardiac myxoma complicated with mediastinal lymphadenopathy or left ventricular hypertrophy. Increased expression of IL-6 is observed in the myocardium of all donor hearts showing marked dysfunction. Myocardial IL-6 concentrations are also significantly higher in LVAD candidates compared with advanced heart failure patients. Although the IL-6 family plays a central role in the pathophysiology of cardiovascular diseases, it remains to be determined whether the IL-6 family is beneficial or detrimental. Future study will be needed to resolve this question.  

Effects of probucol and pravastatin on common carotid atherosclerosis in patients with asymptomatic hypercholesterolemia. Fukuoka Atherosclerosis Trial (FAST)

OBJECTIVES: This study investigated the effect of reducing serum lipids on carotid artery intima-media thickness (IMT) in asymptomatic patients with hypercholesterolemia from Fukuoka, Japan. BACKGROUND: Carotid atherosclerosis is a strong, independent predictor of morbidity and mortality in patients with coronary heart disease (CHD). METHODS: A total of 246 asymptomatic hypercholesterolemic patients (mean age 66 years) were randomized to receive either probucol (500 mg/day, n = 82) or pravastatin (10 mg/day, n = 83) or to enter a control group (diet alone, n = 81); they were followed for two years. The change in IMT in the common carotid artery was the primary end point measure, and the incidence of major cardiovascular events was the secondary measure. RESULTS: Over the two-year period, serum low-density lipoprotein (LDL) cholesterol was significantly reduced in the pravastatin group (36%), the probucol group (29%) and the control group (12%) (p < 0.0001, p < 0.0001 and p < 0.05, respectively). After two years, the probucol and pravastatin groups showed a significant reduction in IMT (-13.9% and -13.9% and p < 0.01 and p < 0.01, respectively), but there was significant IMT thickening (23.2%; p < 0.05) in the control group. Probucol reduced the rate of IMT increase, independently of its reduction of LDL or high-density lipoprotein cholesterol. Moreover, there was a significantly lower incidence of cardiac events in the probucol group (2.4%) than in the control group (13.6%) (p = 0.0136). CONCLUSIONS: Probucol reduced cholesterol levels and stabilized plaque, leading to a lower incidence of cardiac events in these hypercholesterolemic patients.  

Circulating interleukin-6 and interleukin-6 receptors in patients with acute and recent myocardial infarction

Interleukin-6 (IL-6), a proinflammatory cytokine, plays a key role in the pathogenesis of coronary artery disease (CAD). We investigated circulating IL-6 and its receptors in patients with CAD. We evaluated 39 Japanese patients with CAD (30 males and 9 females aged 36-79 years), measuring their plasma levels of IL-6 and IL-6 receptors alpha and beta (IL-6R alpha, IL-6R beta). Circulating levels of IL-6, IL-6R alpha and IL-6R beta were measured by an enzyme-linked immunosorbent assay. Blood was sampled immediately after admission and again after 1, 2, 3, 6 and 9 h, then every 12 h for 5 days. Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) were measured on day 3 after symptom onset. Plasma levels of IL-6 and IL-6Rs were significantly increased in 28 patients with acute myocardial infarction (AMI) compared with 15 normal controls. However, neither IL-6 nor IL-6Rs showed an increase in 6 patients with angina pectoris. We observed two peaks for circulating IL-6 in AMI, the first of which showed a significant correlation with ANP as well as BNP. These results may help to explain why the amount of IL-6 produced is closely related to the severity of myocardial dysfunction in patients with CAD.  

Reversible posterior leukoencephalopathy syndrome: a misnomer reviewed

Reversible posterior leukoencephalopathy is a syndrome of headache, seizures and visual loss, often associated with an abrupt increase in blood pressure. Prompt diagnosis and therapy with antihypertensives, anticonvulsants, removal of any offending medication and treatment of associated disorders is essential since early treatment might prevent progression to irreversible brain damage. We present six illustrative cases presenting to Christchurch Hospital and review the condition. All were hypertensive, two were receiving immunosuppressant therapy after transplantation and one chemotherapy. Only three made a full recovery. The term reversible posterior leukoencephalopathy is a misnomer as the condition is not always reversible, is not necessarily confined to the posterior regions of the brain and can affect both white and grey matter. Magnetic resonance imaging findings of increased T2 and fluid attenuated inversion recovery signal predominantly involving the posterior regions of the cerebral hemispheres should alert the clinician to the possibility of this diagnosis.  

反复肺炎支原体肺部感染大鼠肺组织中碱性成纤维细胞生长 …

目的 探讨反复肺炎支原体肺部感染大鼠肺组织中碱性成纤维细胞生长因子（ｂＦＧＦ）ｍＲＮＡ表达的变化。方法将８只大鼠于２４周内反复９次经超声雾化吸入肺炎支原体以复制其慢性肺部感染模型，另以４只为对照，随后用ｂＦＧＦｃＤＮＡ核酸探针行核酸分子原位杂交及定量图像分析，观察肺组织ｂＦＧＦｍＲＮＡ表达的变化。结果 （１）感染组动物（４只）支气管肺泡灌洗液肺炎支原体－聚合酶链反应（ＰＣＲ）检测均为阳性，而对照组  

Inhibition of cell invasion and morphological change by troglitazone in human pancreatic cancer cells

Background We have recently demonstrated that peroxisome proliferator activated receptor (PPAR) activation by its selective ligand, troglitazone, potently inhibited cell proliferation in human pancreatic cancer cells. The present study was performed to clarify the role of PPAR in cell invasion/motility in human pancreatic cancer cells.Methods Cell invasive activity was assessed by an in vitro invasion assay, using a Transwell chamber, and by a wound-healing assay, in the human pancreatic cancer cell lines, PK-1 and PK-9. Cell morphology and actin structure were evaluated by phase-contrast and fluorescence microscopy.Results PPAR activation by troglitazone inhibited cell invasion and cell migration in PK-1 and PK-9 cells. We also examined the effect of troglitazone on cell morphology and actin structure because of its effect on cell motility. The size of PK-1 and PK-9 cells that had been incubated with troglitazone became smaller, and the in shape changed from flat to spindle, followed by round. The troglitazone-induced cell rounding was reversible by replacement with troglitazone-free medium. Rhodamine-phalloidin staining revealed a decreased number of actin filaments in PK-1 cells treated with troglitazone. In cells treated with mycalolide B, an actin depolymerizing agent, troglitazone failed to induce cell rounding.Conclusions These results suggest that PPAR activation by troglitazone inhibited cell motility and changed cell morphology through modulating actin organization.  

Association of mannose binding lectin (MBL) gene polymorphism and serum MBL concentration with characteristics and progression of systemic lupus erythematosus

OBJECTIVE: To determine whether occurrence, characteristics, and progression of systemic lupus erythematosus (SLE) are associated with polymorphism of the mannose binding lectin (MBL) gene and with serum MBL concentration. METHODS: Codon 54 MBL gene polymorphism of 147 patients with SLE and 160 healthy controls was determined by polymerase chain reaction-restriction fragment length polymorphism. Serum concentration of MBL was measured by enzyme immunoassay. Fluctuations of serum MBL were analysed with respect to disease characteristics and activity. RESULTS: Frequency of homozygosity for codon 54 minority allele was 6% (9/147) in patients with SLE, and significantly higher than in controls (p = 0.0294, Fisher's exact test). MBL polymorphism in patients with SLE was not significantly associated with disease characteristics or immunological phenotypes. Patients homozygous for the B allele tended to have a higher risk of infection during treatment. Levels of C3 and CH(50) were slightly, but significantly, associated with serum MBL concentration in patients with SLE homozygous for the majority allele. During the course of SLE, serum MBL concentration increased in 6/14 patients, and decreased in 7 after initiation of immunosuppressive treatment. CONCLUSIONS: MBL gene polymorphism influences susceptibility to SLE, but has no direct effect on disease characteristics. Serum MBL levels fluctuate during the course of SLE in individual patients. MBL genotyping may be useful in assessing the risk of infection during treatment of SLE.  

Hepatitis C Virus Core Protein Modulates Fatty Acid Metabolism and Thereby Causes Lipid Accumulation in the Liver

We studied the roles of hepatitis C virus (HCV) core protein in hepatic steatosis and changes in hepatic lipid metabolism. HCV core protein expression plasmid was transfected in HepG2 . Triacylglyceride (TG) and mRNA level associated with lipid metabolism were measured. Male C57BL/6 mice were infected with HCV core recombinant adenovirus and used for lipids and mRNA studies. In HCV core protein-expressing cells, peroxisome proliferator-activated receptor (PPAR)α, multidrug resistance protein (MDR) 3, and microsomal triglyceride transfer protein (MTP) were down-regulated 48 hr after transfection. In HCV core protein-expressing mice, hepatic TG content and hepatic thiobarbituric acid-reactive substances increased. PPARα, MDR2, acyl-CoA oxidase (AOX), and carnitine palmitoyl transferase-1 (CPT-1) were down-regulated. HCV core protein down-regulated lipid metabolism-associated gene expression, Mdr2, CPT, and AOX, accompanied by down-regulation of PPARα. There findings may contribute to the understanding of HCV-related steatosis, induction of reactive oxygen species, and carcinogenesis.  

Recent insights into digestive motility in functional dyspepsia

Functional gastrointestinal disorders, such as functional dyspepsia (FD) and irritable bowel syndrome, are common pathologies of the gut. FD is a clinical syndrome defined as chronic or recurrent pain or discomfort of unknown origin in the upper abdomen. The pathophysiological mechanisms responsible for FD have not been fully elucidated, but new ideas regarding its pathophysiology and the significance of the pathophysiology with respect to the symptom pattern of FD have emerged. In particular, there is growing interest in alterations in gastric motility, such as accommodation to a meal or gastric emptying, and visceral sensation in FD. The mechanisms underlying impaired gastroduodenal motor function are unclear, but possible factors include abnormal neurohormonal function, autonomic dysfunction, visceral hypersensitivity to acid or mechanical distention, Helicobacter pylori infection, acute gastrointestinal infection, psychosocial comorbidity, and stress. Although the optimum treatment for FD is not yet clearly established, acid-suppressive drugs, prokinetic agents, eradication of H. pylori, and antidepressants have been widely used in the management of patients with FD. The therapeutic efficacy of prokinetics such as itopride hydrochloride and mosapride citrate in the treatment of FD is supported by the results of relatively large and well-controlled studies. In addition, recent research has yielded new therapeutic agents and modalities for dysmotility in FD, including agonists/antagonists of various sensorimotor receptors, activation of the nitrergic pathway, kampo medicine, acupuncture, and gastric electric stimulation. This review discusses recent research on the pathophysiology of and treatment options for FD, with special attention given to digestive dysmotility.