Peroxisome Proliferator-Activated Receptor γ Induces the Expression of Tissue Factor Pathway Inhibitor-1 (TFPI-1) in Human Macrophages.

Tissue factor (TF) is the initiator of the blood coagulation cascade after interaction with the activated factor VII (FVIIa). Moreover, the TF/FVIIa complex also activates intracellular signalling pathways leading to the production of inflammatory cytokines. The TF/FVIIa complex is inhibited by the tissue factor pathway inhibitor-1 (TFPI-1). Peroxisome proliferator-activated receptor gamma (PPARγ) is a transcription factor that, together with PPARα and PPARß/δ, controls macrophage functions. However, whether PPARγ activation modulates the expression of TFP1-1 in human macrophages is not known. Here we report that PPARγ activation increases the expression of TFPI-1 in human macrophages in vitro as well as in vivo in circulating peripheral blood mononuclear cells. The induction of TFPI-1 expression by PPARγ ligands, an effect shared by the activation of PPARα and PPARß/δ, occurs also in proinflammatory M1 and in anti-inflammatory M2 polarized macrophages. As a functional consequence, treatment with PPARγ ligands significantly reduces the inflammatory response induced by FVIIa, as measured by variations in the IL-8, MMP-2, and MCP-1 expression. These data identify a novel role for PPARγ in the control of TF the pathway.

The neuron-derived orphan receptor 1 (NOR1) is induced upon human alternative macrophage polarization and stimulates the expression of markers of the M2 phenotype.

BACKGROUND: Atherosclerosis is an inflammatory disease in which macrophages play a crucial role. Macrophages are present in different phenotypes, with at the extremes of the spectrum the classical M1 pro-inflammatory and the alternative M2 anti-inflammatory macrophages. The neuron-derived orphan receptor 1 (NOR1), together with Nur77 and Nurr1, are members of the NR4A orphan nuclear receptor family, expressed in human atherosclerotic lesion macrophages. However, the role of NOR1 in human macrophages has not been studied yet. OBJECTIVES: To determine the expression and the functions of NOR1 in human alternative macrophages. METHODS AND RESULTS: In vitro IL-4 polarization of primary monocytes into alternative M2 macrophages enhances NOR1 expression in human but not in mouse macrophages. Moreover, NOR1 expression is most abundant in CD68+MR+ alternative macrophage-enriched areas of human atherosclerotic plaques in vivo. Silencing NOR1 in human alternative macrophages decreases the expression of several M2 markers such as the Mannose Receptor (MR), Interleukin-1 Receptor antagonist (IL-1Ra), CD200 Receptor (CD200R), coagulation factor XIII A1 polypeptide (F13A1), Interleukin 10 (IL-10) and the Peroxisome Proliferator-Activated Receptor (PPAR)γ. Bioinformatical analysis identified F13A1, IL-1Ra, IL-10 and the Matrix Metalloproteinase-9 (MMP9) as potential target genes of NOR1 in human alternative macrophages. Moreover, expression and enzymatic activity of MMP9 are induced by silencing and repressed by NOR1 overexpression in M2 macrophages. CONCLUSIONS: These data identify NOR1 as a transcription factor induced during alternative differentiation of human macrophages and demonstrate that NOR1 modifies the alternative macrophage phenotype.

The coronary artery disease-associated gene C6ORF105 is expressed in human macrophages under the transcriptional control of PPARγ.

Coronary artery disease (CAD) is a major cause of morbidity and mortality. Mutations in C6ORF105, associated with decreased gene expression, positively correlate with the risk of CAD in Chinese populations. Moreover, the C6ORF105-encoded protein may play a role in coagulation. Here, we report that C6ORF105 gene expression is lower in circulating mononuclear cells from obese diabetic than lean subjects. Moreover, C6ORF105 is expressed in human macrophages and atherosclerotic lesions, where its expression positively correlates with expression of the transcription factor Peroxisome Proliferator-Activated Receptor (PPAR)γ. Activation of PPARγ increases, in a PPARγ-dependent manner, the expression of C6ORF105 in human macrophages and atherosclerotic lesions.

Enhanced VDUP-1 gene expression by PPARgamma agonist induces apoptosis in human macrophage.

The fate and phenotype of lesion macrophages is regulated by cellular oxidative stress. Thioredoxin-1 (Trx-1) plays a major role in the regulation of cellular redox balance, with resultant effects on gene expression and cellular responses including cell growth and death. Trx-1 activity is inhibited by interaction with vitamin D-upregulated protein-1 (VDUP-1). Peroxisome proliferator-activated receptor gamma (PPARgamma) is expressed by human monocyte-derived macrophages (HMDM) and PPARgamma agonism has been reported to decrease expression of inflammatory genes and to promote apoptosis of these cells. To determine whether VDUP-1 may be involved in regulating the effects of PPARgamma agonists in macrophages, we investigated the effect of a synthetic PPARgamma agonist (GW929) on the expression of VDUP-1 in HMDM. GW929 concentration-dependently increased HMDM expression of VDUP-1 (mRNA and protein). Transfection of different fragments of the VDUP-1 promoter as well as gel shift analysis revealed the presence of functional PPARgamma response elements (PPRE) in the promoter. Under conditions in which PPAR agonism altered levels of VDUP-1, caspase-3 activity, and macrophage apoptosis were also elevated. The results suggest that PPARgamma activation stimulates apoptosis in human macrophages by altering the cellular redox balance via regulation of VDUP-1.

REDD2 gene is upregulated by modified LDL or hypoxia and mediates human macrophage cell death.

OBJECTIVE: Cholesterol accumulation in macrophages is known to alter macrophage biology. In this article we studied the impact of macrophage cholesterol loading on gene expression and identified a novel gene implicated in cell death. METHODS AND RESULTS: The regulated in development and DNA damage response 2 (REDD2) gene was strongly upregulated as THP-1 macrophages are converted to foam cells. These results were confirmed by Northern blot of RNA from human monocyte-derived macrophages (HMDM) treated with oxidized LDL (oxLDL). Human REDD2 shares 86% amino acid sequence identity with murine RTP801-like protein, which is 33% identical to RTP801, a hypoxia-inducible factor 1-responsive gene involved in apoptosis. Treatment of HMDM with desferrioxamine, a molecule that mimics the effect of hypoxia, increased expression of REDD2 in a concentration-dependent fashion. Transfection of U-937 and HMEC cells with a REDD2 expression vector increased the sensitivity of the cells for oxLDL-induced cytotoxicity, by inducing a shift from apoptosis toward necrosis. In contrast, suppression of mRNA expression using siRNA approach resulted in increased resistance to oxLDL treatment. CONCLUSIONS: We showed that stimulation of REDD2 expression in macrophages increases oxLDL-induced cell death, suggesting that REDD2 gene might play an important role in arterial pathology.

Thioredoxin reductase 1 is upregulated in atherosclerotic plaques: specific induction of the promoter in human macrophages by oxidized low-density lipoproteins.

Uptake of modified low-density lipoproteins (LDLs) by macrophages in the arterial wall is an important event in atherogenesis. Indeed, oxidatively modified LDLs (oxLDLs) are known to affect various cellular processes by modulating oxidation-sensitive signaling pathways. Here we found that the ubiquitous 55 kDa selenoprotein thioredoxin reductase 1 (TrxR1), which is a key enzyme for cellular redox control and antioxidant defense, was upregulated in human atherosclerotic plaques and expressed in foam cells. Using reverse transcription polymerase chain reaction analysis, we also found that oxLDLs, but not native LDLs (nLDLs), dose-dependently increased TrxR1 mRNA in human monocyte-derived macrophages (HMDMs). This stimulating effect was specific for oxLDLs, as pro-inflammatory factors, such as lipopolysaccharides (LPSs), interleukin-1beta (IL-1beta), interleukin-6 (Il-6), and tumor necrosis factor alpha (TNFalpha), under the same conditions, failed to induce TrxR1 mRNA levels to the same extent. Moreover, phorbol ester-differentiated THP-1 cells or HMDMs transiently transfected with TrxR1 promoter fragments linked to a luciferase reporter gene allowed identification of a defined promoter region as specifically responding to the phospholipid component of oxLDLs (p <.05 vs. phospholipid component of nLDLs). Gel mobility shift analyses identified a short 40-nucleotide stretch of the promoter carrying AP-1 and HoxA5 consensus motifs that responded with an altered shift pattern in THP-1 cells treated with oxLDLs, however, without evident involvement of either the Fos, Jun, Nrf2 or HoxA5 transcription factors.

[Pneumonia in elder institutionalized patients:derivation and/or prognostic classification criterion]. / Neumoní en el anciano institucionalizado: criterios de derivación y/o clasificación pronóstica.

OBJECTIVE: To know the clinical features of nursing home residents with pneumonia comparing with patients with Community-acquired pneumonia and identify the main prognostic index of mortality. MATERIAL AND METHODS: Longitudinal prospective study including all the elderly patients hospitalized in Cantoblanco Hospital of Madrid during the year 2001 for pneumonia and classified according to the Fine prognosis index and the SEPAR criteria. RESULTS: Of the 78 patients with pneumonia, 27 came from Residence, with an average of age of 86.85(+/- 6.43) years old, opposite to 83.11 (+/- 5.87) years in patients with Community acquired pneumonia ( p<0.05). Of all of them, 33,3% belonged to class IV and 66.7% to class V of Fine. Of all the variables studied, only the age (p= 0.03) and the hypoxemia (p= 0.03) were statistical significant. CONCLUSIONS: Nursing home residents with pneumonia are older and have more prevalence of morbi-mortality than those with Community acquired pneumonia. In our study, the age and the hypoxemia were the two independent prognosis factors associate to more mortality.

Neumonía en el anciano institucionalizado: criterios de derivación y/o clasificación pronóstica / Pneumonia in elder institutionalized patients: derivation and/or prognostic classification criterion

Objetivo: Conocer el perfil clínico de los pacientes con neumonía procedentes de Residencia comparándolo con los de neumonía adquirida en la comunidad (NAC) no institucionalizados e identificar los principales índices pronósticos de mortalidad. Material y métodos: Estudio prospectivo longitudinal de todos los ancianos ingresados en el Hospital de Cantoblanco de Madrid durante el año 2001 diagnosticados de neumonía y clasificados según el índice pronóstico de Fine y los criterios de la SEPAR. Resultados: De los 78 pacientes con neumonía, 27 procedían de Residencia, con una edad media de 86,85 (ñ 6,43) años, frente a 83,11 (ñ 5,87) años en los procedentes de domicilio (p<0,05). De ellos, el 33,3 por ciento pertenecían a la clase IV y el 66,7 por ciento a la clase V de Fine. De todas las variables estudiadas, sólo la edad (p= 0,03) y la hipoxemia (p= 0,01) fueron estadísticamente significativas. Conclusiones: Los pacientes con neumonía procedentes de Residencia tienen mayor edad y mayor prevalencia de morbi-mortalidad que los procedentes de su domicilio. En nuestro estudio, la edad y la hipoxemia son los dos factores pronósticos independientes asociados a mayor mortalidad (AU)

Systemic tissue inhibitor of metalloproteinase-1 gene delivery reduces neointimal hyperplasia in balloon-injured rat carotid artery.

Metalloproteinases (MMP)-2 and MMP-9 play a role in smooth muscle cell (SMC) migration from the media to the intima following arterial injury. Intravenous administration of adenovirus encoding tissue inhibitor of metalloproteinase-1 (TIMP-1) into balloon-injured rat arteries (3 x 10(11) viral particles/rat; n=7) resulted in a transient expression of TIMP-1 and a significant inhibition of neointima thickening within 16 days ( approximately 40% vs. control; P=0.012). Three days after injury, the number of intimal SMCs was decreased by approximately 98% in TIMP-1-treated rats. However, no alteration was seen in intimal SMC proliferation after 13 days of injury. Therefore, our results show that systemic gene transfer of TIMP-1 is a promising approach in early restenosis treatment.

Apolipoprotein AII enrichment of HDL enhances their affinity for class B type I scavenger receptor but inhibits specific cholesteryl ester uptake.

Apolipoproteins of high density lipoprotein (HDL) and especially apolipoprotein (apo)AI and apoAII have been demonstrated as binding directly to the class B type I scavenger receptor (SR-BI), the HDL receptor that mediates selective cholesteryl ester uptake. However, the functional relevance of the binding capacity of each apolipoprotein is still unknown. The human adrenal cell line, NCI-H295R, spontaneously expresses a high level of SR-BI, the major apoAI binding protein in these cells. As previously described for murine SR-BI, free apoAI, palmitoyl-oleoyl-phosphatidylcholine (POPC)-AI, and HDL are good ligands for human SR-BI. In vitro displacement of apoAI by apoAII in HDLs or in Lp AI purified from HDL by immunoaffinity enhances their ability to compete with POPC-AI to bind to SR-BI and also enhances their direct binding capacity. The next step was to determine whether the higher affinity of apoAII for SR-BI correlated with the specific uptake of cholesteryl esters from these HDLs. Free apoAII and, to a lesser extent, free apoAI that were added to the cell medium during uptake experiments inhibited the specific uptake of [(3)H]cholesteryl esters from HDL, indicating that binding sites on cells were the same as cholesteryl ester uptake sites. In direct experiments, the uptake of [(3)H]cholesteryl esters from apoAII-enriched HDL was highly reduced compared with the uptake from native HDL. These results demonstrate that in the human adrenal cell line expressing SR-BI as the major HDL binding protein, efficient apoAII binding has an inhibitory effect on the delivery of cholesteryl esters to cells.

Cell culture conditions determine apolipoprotein CIII secretion and regulation by fibrates in human hepatoma HepG2 cells.

Fibrates are widely used drugs which lower triglycerides and increase HDL concentrations in serum. Recent findings from our laboratory have shown that fibrates repress apolipoprotein (apo) CIII gene expression, an effect that explains partially the triglyceride-lowering activity of these drugs. The goal of the present study was to compare the effect of various fibrates on apo CIII gene expression in the human hepatoblastoma cell line HepG2. First, we demonstrate that the level of apo CIII secretion by HepG2 cells is controlled by serum factors whereas apo CIII mRNA levels are not and even increase under conditions when apo CIII secretion dramatically decreases. Twelve different fetal calf serum batches were tested during this study and apo CIII secretion in cell medium could only be detected with three of them. The effect of serum on apolipoprotein secretion was more pronounced for apo CIII whereas other apolipoproteins (apo E, apo B, apo AII and apo AI) were affected to a lesser extent. Under serum conditions allowing apo CIII secretion, treatment with the peroxisome-proliferator activated receptor (PPAR)alpha activators fenofibrate, gemfibrozil and Wy-14643 result in a marked lowering of apo CIII secretion and gene expression, this effect being most pronounced with Wy-14643. Comparison of the activity of a PPARgamma-specific ligand, the antidiabetic thiazolidinedione, BRL-49653 and a PPARalpha ligand Wy-14643 showed a marked decrease of apo CIII secretion and gene expression after activation of PPARalpha but not PPARgamma. In conclusion, fibrates down-regulate apo CIII gene expression in human HepG2 cells, most likely via PPARalpha but not via PPARgamma. However, these effects are only observed in HepG2 cells cultured under appropriate conditions.

[Comparative hemodynamic effects of sevoflurane and halothane at tele-expiratory concentration in intubation of infants]. / Effets hémodynamiques comparatifs du sévoflurane et de l'halothane à la concentration télé-expiratoire d'intubation chez le nourrisson.

OBJECTIVE: To compare the cardiovascular changes at the end-tidal concentrations of sevoflurane versus halothane required for tracheal intubation in infants (intubation MAC). STUDY DESIGN: Prospective randomized study. PATIENTS: Thirty-two infants, ASA physical status 1 or 2, scheduled for elective surgery, randomized to receive either halothane or sevoflurane for anaesthetic induction by inhalation. METHODS: Cardiovascular and echocardiographic data were recorded in both groups at baseline, and at the end-tidal concentrations needed for intubation. RESULTS: Intubation MAC was significantly less with sevoflurane than with halothane in infants. Sevoflurane did not change heart rate (HR) and cardiac index (CI) compared to values when awake. Sevoflurane significantly decreased blood pressure, systemic vascular resistance (SVR) and shortening fraction (SF). Myocardial contractility assessed by stress-velocity index (SVI) and stress-shortening index (SSI) decreased significantly at the intubation MAC, but did not fall into the abnormal range. Halothane caused a greater decrease in HR, SF, SSI, and CI than sevoflurane. CONCLUSIONS: Sevoflurane decreases cardiac output less than halothane in infants at the intubation MAC, due to a lower end-tidal concentration at intubation MAC and to less effects on haemodynamic variables.

Comparative hemodynamic depression of sevoflurane versus halothane in infants: an echocardiographic study.

BACKGROUND: The cardiovascular side effects of volatile anesthetics are one of the chief causes of postoperative complications in children, and infants seem to be at the greatest risk for this. This study compared cardiovascular changes at equipotent concentrations of sevoflurane and halothane in infants. METHODS: Thirty infants classified as American Society of Anesthesiologists physical status I or II who required elective surgery were randomized to receive either halothane or sevoflurane for inhalation induction. Cardiovascular and echocardiographic data were recorded in both groups at baseline and at end-tidal concentrations of 1 and 1.5 minimum alveolar concentration (MAC). RESULTS: Sevoflurane did not alter heart rate or cardiac index at all concentrations compared with awake values. Sevoflurane significantly decreased blood pressure and systemic vascular resistance compared with awake values at all concentrations. Shortening fraction and rate-corrected velocity of circumferential fiber shortening decreased at 1.5 but not at 1 MAC. Myocardial contractility assessed by stress-velocity index and stress-shortening index decreased significantly at all concentrations, but did not fall into the abnormal range at any concentration. Halothane caused a greater decrease in heart rate, shortening fraction, stress-shortening index, velocity of circumferential fiber shortening, stress-velocity index, and cardiac index at all concentrations than did sevoflurane. CONCLUSION: Sevoflurane causes a lesser decrease in cardiac output than does halothane in infants.

Modulation of lipoprotein B binding to the LDL receptor by exogenous lipids and apolipoproteins CI, CII, CIII, and E.

We have recently shown that apo B-containing lipoproteins isolated by immunoaffinity chromatography bind to the LDL receptor with an affinity dependent on their apo E or apo CIII content. However, these lipoproteins--LpB:E, LpB:CIII, and LpB:CIII:E--isolated from whole plasma have variable lipid and apolipoprotein contents, and it is difficult to consider each parameter separately, particularly because an increase in the apo CIII content is always associated with an increase in the content of other C apolipoproteins. Therefore, we used affinity-purified LpB free of other apolipoproteins. Lipid content of LpB was increased by incubation with a lipid emulsion, and this triglyceride-enriched LpB was named TG-LpB. Free apo CI, apo CII, apo CIII, and apo E were added to LpB and TG-LpB and their associations to the lipoprotein were assessed by gel filtration, nondenaturing electrophoresis, and immunoblotting. Molar ratios of 6 (apo E), 30 (apo CII), 20 (apo CIII), and 30 (apo CI) for 1 apo B were obtained. The association of apo CII to LpB and TG-LpB induced modifications to the LpB structure and a redistribution of lipids and apolipoproteins on the lipoprotein particles. The binding of these LpBs and TG-LpBs with and without added apo CI, CII, CIII, and E was tested at 4 degrees C on the LDL receptors of HeLa cells. The increased content of lipids reduced TG-LpB binding to the LDL receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

[Intraspinal epidermoid cysts and lumbar punctures]. / Kystes épidermoïdes intrarachidiens et ponctions lombaires.

The authors describe a case of intra-spinal epidermoid cyst and recall the scarcity of the symptoms of such tumors and their slow evolution and emphasize the very likely part taken by spinal punctures in the genesis of a number of them.