Gastro-oesophageal reflux, eosinophilic airway inflammation and chronic cough

Background and objective: Patients with eosinophilic airway inflammation (EAI) often show a therapeutic response to corticosteroids. Non‐invasive methods of diagnosing EAI are potentially useful in guiding therapy, particularly in conditions such as chronic cough, for which corticosteroids may not be the first‐line treatment. Methods: The value of exhaled nitric oxide (ENO) in the diagnosis of EAI was prospectively investigated in a cohort of 116 patients with chronic cough of varying aetiology. An optimum cut‐off value was derived for differentiating between EAI and non‐EAI causes of chronic cough. As the diagnosis was gastro‐oesophageal reflux in 70 patients (60.3% of the total), the possible relationship between ENO and EAI in the presence or absence of reflux was subsequently investigated. Results: The optimum value of ENO for differentiating EAI (32% of patients) from non‐EAI causes of cough was 33 parts per billion (sensitivity 60.5%, specificity 84.6%). In the subgroup of patients with reflux, ENO was highly specific for the diagnosis of EAI (sensitivity 66%, specificity 100%). Conversely, in the patients without reflux, ENO did not discriminate between cough due to EAI or other causes (sensitivity 100%, specificity 28.9%). Conclusions: These results suggest that the presence or absence of reflux should be taken into consideration when interpreting ENO measurements in the diagnosis of chronic cough associated with EAI.     

Effect of Mediterranean diet on the expression of pro-atherogenic genes in a population at high cardiovascular risk

Experimental and epidemiological studies have demonstrated the beneficial effects of the traditional Mediterranean diet (TMD) on the incidence and progression of atherosclerosis. Several genes play a major role in determining atherosclerosis susceptibility. We compared the short-term effects of two TMD diets versus a control diet on the expression of pro-atherogenic genes. One TMD diet was supplemented with virgin olive oil (VOO) (TMD + VOO) and the other with nuts (TMD + nuts). Gene expression was analyzed in monocytes from 49 asymptomatic high cardiovascular-risk participants (23 men, 26 women), aged 55–80 years. Monocytes were isolated from blood before and 3 months after dietary intervention. We analyzed the expression of genes involved in inflammation [cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and monocyte chemoattractant protein (MCP-1)], genes involved in foam cell formation [low-density lipoprotein receptor-related protein (LRP1), LDL receptor and CD36], and genes involved in thrombosis [tissue factor (TF) and tissue factor pathway inhibitor (TFPI)]. We found that TMD + VOO intervention prevented an increase in COX-2 and LRP1, and reduced MCP-1 expression compared to TMD + nuts or control diet interventions. TMD + nuts specifically increased the expression of CD36 and TFPI compared to TMD + VOO and control diet intervention.Our findings showed that the Mediterranean diet influences expression of key genes involved in vascular inflammation, foam cell formation and thrombosis. Dietary intervention can thus actively modulate the expression of pro-atherothrombotic genes even in a high-risk population.     

Hypoxia exacerbates Ca(2+)-handling disturbances induced by very low density lipoproteins (VLDL) in neonatal rat cardiomyocytes

It is known that myocardium suffers serious alterations under ischemic conditions such as lipid overloading and electrophysiological alterations. However, it is unknown whether intracellular lipid accumulation and calcium dysfunction share common pathophysiological mechanisms under ischemia. The aims of this study were 1) to analyze the effect of normal and high doses of very low density lipoproteins (VLDL) on lipid content and calcium handling; 2) to investigate whether hypoxia modulates the effect of high VLDL doses; and 3) to identify potentially underlying mechanisms in cardiomyocytes. For this purpose, neonatal rat ventricular myocytes cultures were prepared from hearts of 3-4-day-old rats. High doses of VLDL that induced cholesteryl ester (CE) and triglyceride (TG) accumulation strongly reduced sarco(endo)plasmic reticulum Ca ATPase-2 (SERCA-2) expression, calcium transient amplitude and sarcoplasmic reticulum (SR) calcium loading. Interestingly, hypoxia, by upregulating VLDL-receptor expression (4.5-fold at 16h) increased CE (1.5-fold) and TG (3-fold) cardiomyocyte content and exacerbated the negative effect of VLDL on SERCA-2 expression. Functionally, the hypoxic exacerbation of VLDL-mediated SERCA-2 downregulation was translated into a stronger decrease in calcium transient amplitude and SR calcium loading in myocytes exposed simultaneously to hypoxia and high VLDL. In conclusion, high VLDL doses alter calcium handling in cardiomyocytes and SERCA-2 play a pivotal role in the hypoxic exacerbation of VLDL-mediated effects on cardiac calcium handling. Potentiation of VLDL's effects under hypoxia is explained, at least in part, by hypoxic upregulation of the expression of VLDL-receptor.     

Sterol regulatory element binding proteins downregulate LDL receptor-related protein (LRP1) expression and LRP1-mediated aggregated LDL uptake by human macrophages

OBJECTIVE: In the extracellular intima, extracellular matrix proteoglycans favor LDL retention and aggregation (agLDL). In contrast to native LDL (nLDL), agLDL induces high intracellular cholesteryl ester (CE) accumulation in macrophages. It has been suggested that LDL receptor-related protein (LRP1) is involved in agLDL binding and internalization by macrophages. The aim of this work was to analyze whether sterol regulatory element binding proteins (SREBPs) modulate LRP1 expression and LRP1-mediated agLDL uptake by human monocyte-derived macrophages (HMDM). METHODS AND RESULTS: The treatment of HMDM with small anti-LRP1 interfering RNA (siRNA-LRP1) led to the specific inhibition of LRP1 mRNA expression and also to the inhibition of LRP1 protein expression in these cells. In siRNA-LRP1-treated HMDM, CE accumulation from agLDL uptake (84.66+/-5 microg CE/mg protein) was reduced by 95.76+/-5.22%. This suggests that LRP1 plays a pivotal role in agLDL uptake by HMDM. N-acetyl-leucyl-leucyl-norleucinal (ALLN), an inhibitor of SREBP catabolism, maintained high levels of active SREBP-2 and SREBP-1 even in the presence of nLDL and agLDL. Therefore, ALLN induced LDL receptor (LDLR) upregulation. Concomitantly, a strong downregulation of LRP1 mRNA and LRP1 protein was observed in ALLN-treated macrophages. By decreasing LRP1 expression levels, ALLN reduced CE accumulation from agLDL at all tested concentrations. CONCLUSIONS: These results suggest that high levels of active SREBPs downregulate LRP1 expression and intracellular CE accumulation in HMDM.     

Low-density lipoprotein receptor-related protein 1 is associated with proliferation and invasiveness in Her-2/neu and triple-negative breast carcinomas

Low-density lipoprotein receptor-related protein 1, a member of the low-density lipoprotein cholesterol receptor family, has been implicated in the progression of certain tumors; but it remains unclear whether it plays a role in infiltrating ductal breast carcinomas. We studied a series of 81 ductal breast tumors to determine the correlation of low-density lipoprotein receptor-related protein 1 overexpression with clinicopathologic and immunohistochemical characteristics associated with prognosis. Low-density lipoprotein receptor-related protein 1 overexpression was identified in 14% (11/81) of tumors and was correlated with a high nuclear grade (P = .043), high mitotic index (P = .006), and Ki-67 greater than 20% (P = .047). Furthermore, low-density lipoprotein receptor-related protein 1 expression was associated with aggressive carcinomas (triple-negative tumors [21%, 7/33] and Her-2/neu tumors [17%, 4/24]) but not with hormone-dependent carcinomas (0%, 0/24) (P = .040). There was no correlation between low-density lipoprotein receptor-related protein 1 expression and survival, but a trend was found between low-density lipoprotein receptor-related protein 1 overexpression and tumor recurrence. Low-density lipoprotein receptor-related protein 1 overexpression was related to proliferation and invasiveness in Her-2/neu and triple-negative breast carcinoma. Moreover, patients with low-density lipoprotein receptor-related protein 1-positive tumors had higher cholesterol levels (62.5%, 5/8) than those with low-density lipoprotein receptor-related protein 1-negative tumors (40%, 19/47). Nevertheless, the correlation between low-density lipoprotein receptor-related protein 1 and hypercholesterolemia was not statistically significant; but cholesterol levels were higher in patients with triple-negative breast carcinoma (60%, 15/25) and Her-2/neu carcinomas (40%, 6/15) than in luminal-A carcinomas (20%, 3/15) (P = .046). These findings suggest a relationship between hypercholesterolemia and aggressiveness of ductal breast carcinomas.     

Circulating endothelial cells in patients with heart failure and left ventricular dysfunction

Introduction and Aims: Acute and chronic heart failure may manifest different degrees of endothelial damage and angiogenesis. Circulating endothelial cells (CEC) have been identified as marker of vascular damage. The aim of our study was to evaluate the evolution of the CEC at different stages of patients with heart failure. We also investigated a potential correlation between CEC and markers of vascular damage and angiogenesis. Methods: We studied 32 heart failure patients at hospital admission (acute phase) and at revision after 3 months (stable phase) and 32 controls. Circulating markers of endothelial damage (CEC; von Willebrand factor, vWF and soluble E-selectin, sEsel) and angiogenesis (vascular endothelial growth factor, VEGF and thrombospondin-1) were quantified. Results: Levels of CEC, vWF, sEsel and VEGF are significantly higher in heart failure patients than in controls. Levels of CEC (36.9 ± 15.3 vs. 21.5 ± 10.0 cells/ml; p< 0.001), vWF (325 ± 101 vs. 231 ± 82%; p< 0.001) and VEGF (26.3 ± 15.2 vs. 21.9 ± 11.9 ng/ml; p< 0.001) are significantly higher in the acute phase than in the stable phase of heart failure. CEC levels correlate with vWF and VEGF. Results show than 100% of patients in acute phase and 37.5% in stable phase have levels of CEC higher than the 99th percentile of the distribution of controls (16 cells/ml). Therefore, increases in CEC represent a relative risk of 9.5 for heart failure patients suffering from acute phase. Conclusions: CEC, in addition to being elevated in heart failure, correlate with vWF levels, providing further support for CEC as markers of endothelial damage. Levels of CEC are associated with the acute phase of heart failure and could be used as a marker of the worsening in heart failure.