LPS-induced cytokine production and expression of LPS-receptors by peripheral blood mononuclear cells of patients with familial hypercholesterolemia and the effect of HMG-CoA reductase inhibitors

Immune signaling as a node of interaction between systems that sex-specifically develop during puberty and adolescence

Adolescence is pivotal for neural and behavioral development across species. During this period, maturation occurs in several biological systems, the most well-recognized being activation of the hypothalamic-pituitary-gonadal axis marking pubertal onset. Increasing comparative studies of sex differences have enriched our understanding of systems integration during neurodevelopment. In recent years, immune signaling has emerged as a key node of interaction between a variety of biological signaling processes. Herein, we review the age- and sex-specific changes that occur in neural, hypothalamic-pituitary, and microbiome systems during adolescence. We then describe how immune signaling interacts with these systems, and review recent preclinical evidence indicating that immune signaling may play a central role in integrating changes in their typical and atypical development during adolescence. Finally, we discuss the translational relevance of these preclinical studies to human health and wellness.

Statins and Bempedoic Acid: Different Actions of Cholesterol Inhibitors on Macrophage Activation

Statins represent the most prescribed class of drugs for the treatment of hypercholesterolemia. Effects that go beyond lipid-lowering actions have been suggested to contribute to their beneficial pharmacological properties. Whether and how statins act on macrophages has been a matter of debate. In the present study, we aimed at characterizing the impact of statins on macrophage polarization and comparing these to the effects of bempedoic acid, a recently registered drug for the treatment of hypercholesterolemia, which has been suggested to have a similar beneficial profile but fewer side effects. Treatment of primary murine macrophages with two different statins, i.e., simvastatin and cerivastatin, impaired phagocytotic activity and, concurrently, enhanced pro-inflammatory responses upon short-term lipopolysaccharide challenge, as characterized by an induction of tumor necrosis factor (TNF), interleukin (IL) 1β, and IL6. In contrast, no differences were observed under long-term inflammatory (M1) or anti-inflammatory (M2) conditions, and neither inducible NO synthase (iNOS) expression nor nitric oxide production was altered. Statin treatment led to extracellular-signal regulated kinase (ERK) activation, and the pro-inflammatory statin effects were abolished by ERK inhibition. Bempedoic acid only had a negligible impact on macrophage responses when compared with statins. Taken together, our data point toward an immunomodulatory effect of statins on macrophage polarization, which is absent upon bempedoic acid treatment.

The Effects of Statins on Neurotransmission and Their Neuroprotective Role in Neurological and Psychiatric Disorders

Statins are among the most widely used drug classes in the world. Apart from their basic mechanism of action, which is lowering cholesterol levels, many pleiotropic effects have been described so far, such as anti-inflammatory and antiatherosclerotic effects. A growing number of scientific reports have proven that these drugs have a beneficial effect on the functioning of the nervous system. The first reports proving that lipid-lowering therapy can influence the development of neurological and psychiatric diseases appeared in the 1990s. Despite numerous studies about the mechanisms by which statins may affect the functioning of the central nervous system (CNS), there are still no clear data explaining this effect. Most studies have focused on the metabolic effects of this group of drugs, however authors have also described the pleiotropic effects of statins, pointing to their probable impact on the neurotransmitter system and neuroprotective effects. The aim of this paper was to review the literature describing the impacts of statins on dopamine, serotonin, acetylcholine, and glutamate neurotransmission, as well as their neuroprotective role. This paper focuses on the mechanisms by which statins affect neurotransmission, as well as on their impacts on neurological and psychiatric diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), vascular dementia (VD), stroke, and depression. The pleiotropic effects of statin usage could potentially open floodgates for research in these treatment domains, catching the attention of researchers and clinicians across the globe.

High-Throughput Screening for CEBPD-Modulating Compounds in THP-1-Derived Reporter Macrophages Identifies Anti-Inflammatory HDAC and BET Inhibitors

This study aimed to identify alternative anti-inflammatory compounds that modulate the activity of a relevant transcription factor, CCAAT/enhancer binding protein delta (C/EBPδ). C/EBPδ is a master regulator of inflammatory responses in macrophages (Mϕ) and is mainly regulated at the level of CEBPD gene transcription initiation. To screen for CEBPD-modulating compounds, we generated a THP-1-derived reporter cell line stably expressing secreted alkaline phosphatase (SEAP) under control of the defined CEBPD promoter (CEBPD::SEAP). A high-throughput screening of LOPAC^®1280 and ENZO^®774 libraries on LPS- and IFN-γ-activated THP-1 reporter Mϕ identified four epigenetically active hits: two bromodomain and extraterminal domain (BET) inhibitors, I-BET151 and Ro 11-1464, as well as two histone deacetylase (HDAC) inhibitors, SAHA and TSA. All four hits markedly and reproducibly upregulated SEAP secretion and CEBPD::SEAP mRNA expression, confirming screening assay reliability. Whereas BET inhibitors also upregulated the mRNA expression of the endogenous CEBPD, HDAC inhibitors completely abolished it. All hits displayed anti-inflammatory activity through the suppression of IL-6 and CCL2 gene expression. However, I-BET151 and HDAC inhibitors simultaneously upregulated the mRNA expression of pro-inflammatory IL-1ß. The modulation of CEBPD gene expression shown in this study contributes to our understanding of inflammatory responses in Mϕ and may offer an approach to therapy for inflammation-driven disorders.

Anti-inflammatory Action of Statins in Cardiovascular Disease: the Role of Inflammasome and Toll-Like Receptor Pathways

Atherosclerosis is one type of cardiovascular disease (CVD) in which activation of the NLRP3 inflammasome and toll-like receptor (TLR) pathways is implicated. One of the most effective treatments for atherosclerosis is the use of statin medications. Recent studies have indicated that statins, in addition to their lipid-lowering effects, exert inhibitory and/or stimulatory effects on the NLRP3 inflammasome and TLRs. Some of the statins lead to activation of the inflammasome and subsequently cause secretion of IL-1β and IL-18. Thus, these actions may further aggravate the disease. On the other hand, some statins cause inhibition of the inflammasome or TLRs and along with lipid-lowering, help to improve the disease by reducing inflammation. In this article, we discuss these contradictory studies and the mechanisms of action of statins on the NLRP3 inflammasome and TLR pathways. The dose-dependent effects of statins on the NLRP3 complex are related to their chemistry, pharmacokinetic properties, and danger signals. Lipophilic statins have more pleiotropic effects on the NLRP3 complex in comparison to hydrophilic statins. Statins can suppress TLR4/MyD88/NF-ĸB signaling and cause an immune response shift to an anti-inflammatory response. Furthermore, statins inhibit the NF-ĸB pathway by decreasing the expression of TLRs 2 and 4. Statins are cost-effective drugs, which should have a continued future in the treatment of atherosclerosis due to both their immune-modulating and lipid-lowering effects.

Probiotic consumption during puberty mitigates LPS-induced immune responses and protects against stress-induced depression- and anxiety-like behaviors in adulthood in a sex-specific manner

Puberty/adolescence is a significant period of development and a time with a high emergence of psychiatric disorders. During this period, there is increased neuroplasticity and heightened vulnerability to stress and inflammation. The gut microbiome regulates stress and inflammatory responses and can alter brain chemistry and behaviour. However, the role of the gut microbiota during pubertal development remains largely uninvestigated. The current study examined gut manipulation with probiotics during puberty in CD1 mice on lipopolysaccharide (LPS)-induced immune responses and enduring effects on anxiety- and depression-like behaviours and stress-reactivity in adulthood. Probiotics reduced LPS-induced sickness behaviour at 12 h in females and at 48 h following LPS treatment in males. Probiotics also reduced LPS-induced changes in body weight at 48 h post-treatment in females. Probiotic treatment also prevented LPS-induced increases in pro- and anti-inflammatory peripheral cytokines at 8 h following LPS treatment, reduced central cytokine mRNA expression in the hypothalamus, hippocampus and PFC, and prevented LPS-induced changes to in the gut microbiota. A single exposure to LPS during puberty resulted in enduring depression-like behaviour in female mice, and anxiety-like behaviour in male mice in adulthood. However, pubertal exposure to probiotics prevented enduring LPS-induced depression-like behaviour in females and anxiety-like behaviors in males. Moreover, probiotics altered toll-like receptor-4 activity in the paraventricular nucleus of the hypothalamus (PVN) in males in response to a novel stressor in adulthood. Our results suggest that the gut microbiome plays an important role in pubertal neurodevelopment. These findings indicate that exposure to probiotics during puberty mitigates inflammation and decreases stress-induced vulnerabilities to emotional behaviours later in life, in a sex-specific manner.

Simvastatin Suppresses Interleukin Iβ Release in Human Peripheral Blood Mononuclear Cells Stimulated With Cholesterol Crystals

Statins are mainstream therapy in the treatment and prevention of cardiovascular disease through inhibitory effects on cholesterol synthesis. However, statins' beneficial effects in cardiovascular disease may also be attributable to their role as anti-inflammatory mediators. Here, we investigated the effects of simvastatin treatment on expression levels of interleukin (IL) 1β in both patient with hyperlipidemia and healthy human peripheral blood mononuclear cells (PBMCs) using cholesterol crystals (CC), a cardiovascular pathogenic stimulus for activation of the NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome. Cholesterol crystal-induced NLRP3 inflammasome activation was used to trigger maturation and release of IL-1β in PBMCs. Specifically, isolated PBMCs from patients with hyperlipidemia at baseline and following 8 weeks of in vivo treatment with simvastatin (10-20 mg) daily were stimulated with lipopolysaccharide (LPS; 100 ng/mL) for 3 hours to induce proIL-Iβ expression followed by CC (2 mg/mL) stimulation for further 18 hours to activate the NLRP3 inflammasome complex to induce maturation/activation of IL-1β. Peripheral blood mononuclear cells were also isolated from healthy donors and stimulated in vitro with simvastatin (50, 25, 5, and 2 µmol/L) prior to stimulation with LPS and CC as described above. The effects of simvastatin treatment on levels of IL-1β expression were determined by enzyme-linked immunosorbent assay and western blot. Both in vitro and in vivo treatments with simvastatin led to a significant reduction in the levels of expression of IL-1β in response to stimulation with CC. Simvastatin inhibits the expression and activation of IL-1β induced by CC in PBMCs, which may contribute to its protective role in patients with cardiovascular disease.

Inflammatory activation of human cardiac fibroblasts leads to altered calcium signaling, decreased connexin 43 expression and increased glutamate secretion

Cardiac fibroblasts, which are abundant in heart tissue, are involved not only in extracellular matrix homeostasis and repair, but also in cardiac remodeling after a myocardial infarction that, in turn, can lead to loss of cardiac function and heart failure. Ca²⁺ signaling is functionally important in many cell types, but the roles of fibroblast signaling and inflammation in the pathogenesis of heart disease are unclear. Here, we tested the hypothesis that inflammatory activation affects cardiac fibroblasts, both in terms of Ca²⁺ signaling and their capacity for intercellular communication through the gap junction channel protein connexin 43 (Cx43). We examined Ca²⁺ responses induced by known modulators of cardiac function such as glutamate, ATP and 5-hydroxytryptamine (5-HT) in human cardiac fibroblasts, under normal and inflammatory conditions. We showed that activation of human cardiac fibroblasts by lipopolysaccharide (LPS) for 24 h altered Ca²⁺ signaling, increased TLR4 and decreased Cx43 expression. In the fibroblasts, LPS treatment increased glutamate-evoked and decreased 5-HT-evoked Ca²⁺ signals. LPS activation also induced increased secretion of glutamate and proinflammatory cytokines from these cells. In summary, we propose that inflammatory stimuli can affect intracellular Ca²⁺ release, Cx43 expression, glutamate release and cytokine secretion in human cardiac fibroblasts. Inflammatory conditions may, therefore, impair intercellular network communication between fibroblasts and cardiomyocytes potentially contributing to cardiac dysfunction.

Innate immune cell activation and epigenetic remodeling in symptomatic and asymptomatic atherosclerosis in humans in vivo

BACKGROUND AND AIMS

We have recently reported that monocytes can undergo functional and transcriptional reprogramming towards a long-term pro-inflammatory phenotype after brief in vitro exposure to atherogenic stimuli such as oxidized LDL. This process is termed 'trained immunity', and is mediated by epigenetic remodeling and a metabolic switch towards increased aerobic glycolysis. We hypothesize that trained immunity contributes to atherogenesis. Therefore, we investigated the inflammatory phenotype and epigenetic remodeling of monocytes from patients with and without established atherosclerosis.

METHODS

Monocytes were isolated from 20 patients with severe symptomatic coronary atherosclerosis (total plaque score >4 on coronary computed tomography angiography) and 17 patients with asymptomatic carotid atherosclerosis and matched controls for both groups. Ex vivo stimulation, RNA analysis and chromatin immunoprecipitation were performed.

RESULTS

Monocytes from patients with symptomatic atherosclerosis have a higher production of pro-inflammatory cytokines upon LPS stimulation than healthy controls (TNFα 499 ± 102 vs. 267 ± 45 pg/ml, p = 0.01). This was associated with lower histone 3 lysine 4 trimethylation (H3K4me3) (19% vs. 33%, p = 0.002), and lower H3K27me3 (0.005% vs. 0.8%, p < 0.0001) on the TNFα promoter. Furthermore, relative mRNA expression of the glycolytic rate limiting enzymes hexokinase 2 and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 was higher in patients (0.7 ± 0.2 vs. 0.3 ± 0.1 resp. 1.7 ± 0.2 vs. 1.0 ± 0.1, p = 0.007 resp. 0.003) compared to control individuals. Interestingly, this pro-inflammatory phenotype was only present in patients with symptomatic atherosclerosis, and not in patients with asymptomatic carotid atherosclerosis.

CONCLUSIONS

Circulating monocytes of patients with symptomatic, but not asymptomatic, atherosclerosis have a pro-inflammatory phenotype and increased expression of glycolytic enzymes, associated with epigenetic remodeling at the level of histone methylation.

Macrophage CD14 expression in human carotid plaques is associated with complicated lesions, correlates with thrombosis, and is reduced by angiotensin receptor blocker treatment

CD14 is a predictor of inflammation and associated with atherosclerosis. We analyzed 118 carotid plaques from patients with symptomatic carotid artery stenosis for expression of the macrophage markers CD14, CD68 and the angiotensin II type 1 receptor (AT1-R). CD14 staining was significantly increased in thrombotic carotid plaques. AT1-R staining was found in macrophage-rich areas, and AT1-R mRNA was detected in plaque macrophages isolated with anti-CD14 immunobeads. In patients treated with an angiotensin receptor blocker, expression of CD14 and CD68 in carotid plaque and serum levels of inflammatory markers were lower than in untreated patients. In vitro, expression of CD14 in human monocyte-derived macrophages was increased by exposure to lipopolysaccharide and decreased by exposure to an angiotensin receptor blocker. Thus, inhibition of the innate immune responsive lipopolysaccharide receptor CD14 in macrophages, rather than AT1-R inhibition, may help explain the anti-inflammatory effects of angiotensin receptor blockade.

Circulating levels of monocyte chemoattractant protein-1 and interleukin-7 in women who have undergone bilateral salpingo-oophorectomy

PURPOSE

The aim of the study reported here was to determine the effect of surgical menopause by bilateral salpingo-oophorectomy (BSO) on circulating levels of cytokines and chemokines related to the pathogenesis of atherosclerosis.

PATIENTS AND METHODS

A total of 110 women were recruited for this study from the outpatient clinic of our facility. We divided the women into three groups: 1) women with a regular menstrual cycle, 2) women in whom less than 5 years had passed since their BSO, and 3) women in whom 5 years or more had passed since their BSO. Concentrations of nine cytokines and chemokines in serum were measured.

RESULTS

The serum monocyte chemoattractant protein-1 (MCP-1) level in women in whom less than 5 years had passed since their BSO was significantly higher than in women with a regular menstrual cycle (P<0.05). There were significant differences in serum interleukin (IL)-7 among the three groups (P=0.035). MCP-1 showed a significant positive correlation (r=0.320, P=0.008) with follicle-stimulating hormone in women with a regular menstrual cycle and in women in whom less than 5 years had passed since their BSO.

CONCLUSION

A hypoestrogenic state due to BSO induced changes in MCP-1 and IL-7 levels. MCP-1 level showed a significant increase in the early period after BSO, while IL-7 level showed a significant decrease in the late period after BSO.

Role of nitric oxide and CCAAT/enhancer-binding protein transcription factor in statin-dependent induction of heme oxygenase-1 in mouse macrophages

The effect of statins on heme oxygenase-1 (HO-1) was compared in 2 murine cell lines, RAW 264.7 and J774A.1 cell lines, and in primary peritoneal macrophages of BALB/c or C57BL/6 mice. The role of endogenous nitric oxide and the type of transcription factors involved were explored. Simvastatin and fluvastatin induced HO-1. Pretreatment of cells with l-NMMA or 1400 W, two different nitric oxide synthase inhibitors, partially blocked statin-dependent induction of HO-1 in RAW 264.7 and J774A.1 but not in primary peritoneal macrophages. Induction of HO-1 by statins was dependent on p-38 MAP kinase activation in all types of macrophages. In RAW 264.7 cells, both statins increased the activity of reporter genes linked to the proximal 1.3 kbp promoter of HO-1 (EC50 of 1.4±0.3 µM for simvastatin and 0.6±0.03 µM for fluvastatin). This effect was significantly blocked by 1400 W (80±5.2% inhibition, p<0.02) and mevalonate, the direct metabolite of HMGCoA reductase. Gel retardation experiments implicated C/EBPβ, AP-1 but not USF, for both RAW 264.7 and primary peritoneal macrophages of C57BL/6 mice. Collectively we showed a differential role of endogenous nitric oxide between macrophage cell lines and primary macrophages and an effect of statins in the protection against inflammation by increasing HO-1 expression.

From ApoA1 upregulation to BET family bromodomain inhibition: discovery of I-BET151

The discovery, synthesis and biological evaluation of a novel series of 7-isoxazoloquinolines is described. Several analogs are shown to increase ApoA1 expression within the nanomolar range in the human hepatic cell line HepG2.

Vascular effects of glycoprotein130 ligands--part II: biomarkers and therapeutic targets

Glycoprotein130 (gp130) ligands are defined by the use of the common receptor subunit gp130 and comprise interleukin (IL)-6, oncostatin M (OSM), IL-11, leukemia inhibitory factor (LIF), cardiotrophin-1 (CT-1), cardiotrophin-like cytokine (CLC), ciliary neurotrophic factor (CNTF), IL-27 and neuropoietin (NP). In part I of this review we addressed the pathophysiological functions of gp130 ligands with respect to the vascular wall. In part II of this review on the vascular effects of gp130 ligands we will discuss data about possible use of these molecules as biomarkers to predict development or progression of cardiovascular diseases. Furthermore, the possibility to modulate circulating levels of gp130 ligands or their tissue expression by specific antibodies, soluble gp130 protein, renin-angiotensin-aldosterone system (RASS) inhibitors, statins, agonists of peroxisome proliferator-activated receptors (PPAR), hormone replacement therapy, nonsteroidal anti-inflammatory drugs (NSAID) or lifestyle modulating strategies are presented. Recent knowledge about the application of recombinant cytokines from the gp130 cytokine family as therapeutic agents in obesity or atherosclerosis is also summarized. Thus the purpose of this review is to cover a possible usefulness of gp130 ligands as biomarkers and targets for therapy in cardiovascular pathologies.

Anti-inflammatory effect of fluvastatin on IL-8 production induced by Pseudomonas aeruginosa and Aspergillus fumigatus antigens in cystic fibrosis

BACKGROUND

Early in life, patients with cystic fibrosis (CF) are infected with microorganisms including bacteria and fungi, particularly Pseudomonas aeruginosa and Aspergillus fumigatus. Since recent research has identified the anti-inflammatory properties of statins (besides their lipid-lowering effects), we investigated the effect of fluvastatin on the production of the potent neutrophil chemoattractant chemokine, IL-8, in whole blood from CF patients, stimulated by Pseudomonas aeruginosa (LPS) and Aspergillus fumigatus (AFA) antigens.

RESULTS

Whole blood from adult patients with CF and from healthy volunteers was collected at the Rennes University Hospital (France). Blood was pretreated for 1 h with fluvastatin (0-300 µM) and incubated for 24 h with LPS (10 µg/mL) and/or AFA (diluted 1/200). IL-8 protein levels, quantified by ELISA, were increased in a concentration-dependent manner when cells were stimulated by LPS or AFA. Fluvastatin strongly decreased the levels of IL-8, in a concentration-dependent manner, in whole blood from CF patients. However, its inhibitory effect was decreased or absent in whole blood from healthy subjects. Furthermore, the inhibition induced by fluvastatin in CF whole blood was reversed in the presence of intermediates within the cholesterol biosynthesis pathway, mevalonate, farnesyl pyprophosphate or geranylgeranyl pyrophosphate that activate small GTPases by isoprenylation.

CONCLUSIONS

For the first time, the inhibitory effects of fluvastatin on CF systemic inflammation may reveal the important therapeutic potential of statins in pathological conditions associated with the over-production of pro-inflammatory cytokines and chemokines as observed during the manifestation of CF. The anti-inflammatory effect could be related to the modulation of the prenylation of signalling proteins.

Short-term treatment with high-dose atorvastatin reduces LDL cholesterol but shows no anti-inflammatory effects in normolipidemic subjects with normal CRP levels

The benefit in reducing cardiovascular risk with statins has been attributed both to cholesterol lowering and pleiotropic effects. These pleiotropic effects are thought to include attenuation of the inflammatory response due to reduced prenylation of proteins in the inflammatory cascade. We conducted studies in normolipidemic subjects to determine if treatment with high-dose (80 mg) atorvastatin could reduce circulating levels of inflammatory markers. We also determined whether high-dose atorvastatin affected the inflammatory response of monocytes stimulated with lipopolysaccharide (LPS) ex vivo. We found that treatment with atorvastatin rapidly and significantly reduced plasma low-density lipoprotein (LDL) cholesterol levels in subjects treated for 2 weeks. However, statin treatment had no discernible effect on plasma levels of the inflammatory markers high-sensitivity C-reactive protein (hsCRP), tumor necrosis factor (TNF)-alpha, or interleukin (IL-6) and no effect on the cytokine response of monocytes following ex vivo stimulation with LPS. High-dose atorvastatin treatment of normolipidemic subjects with normal C-reactive protein levels has no effect on the inflammatory response assessed by monocyte stimulation with LPS ex vivo despite significant reductions in LDL cholesterol levels.

Influenza morbidity and mortality in elderly patients receiving statins: a cohort study

BACKGROUND

Statins possess immunomodulatory properties and have been proposed for reducing morbidity during an influenza pandemic. We sought to evaluate the effect of statins on hospitalizations and deaths related to seasonal influenza outbreaks.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a population-based cohort study over 10 influenza seasons (1996 to 2006) using linked administrative databases in Ontario, Canada. We identified all adults older than 65 years who had received an influenza vaccination prior to the start of influenza season and distinguished those also prescribed statins (23%) from those not also prescribed statins (77%). Propensity-based matching, which accounted for each individual's likelihood of receiving a statin, yielded a final cohort of 2,240,638 patients, exactly half of whom received statins. Statins were associated with small protective effects against pneumonia hospitalization (odds ratio [OR] 0.92; 95% CI 0.89-0.95), 30-day pneumonia mortality (0.84; 95% CI 0.77-0.91), and all-cause mortality (0.87; 95% CI 0.84-0.89). These protective effects attenuated substantially after multivariate adjustment and when we excluded multiple observations for each individual, declined over time, differed across propensity score quintiles and risk groups, and were unchanged during post-influenza season periods. The main limitations of this study were the observational study design, the non-specific outcomes, and the lack of information on medications while hospitalized.

CONCLUSIONS/SIGNIFICANCE

Statin use is associated with a statistically significant but minimal protective effect against influenza morbidity that can easily be attributed to residual confounding. Public health officials and clinicians should focus on other measures to reduce morbidity and mortality from the next influenza pandemic.

Statins inhibit toll-like receptor 4-mediated lipopolysaccharide signaling and cytokine expression

OBJECTIVE

Toll-like receptor 4 (TLR4) is the main receptor for Lipopolysaccharide (LPS). Two relatively common variants of the TLR4 gene are present, resulting in changes from aspartic acid (D) to glycine (G) at residue 299 and from threonine (T) to isoleucine (I) at residue 399, respectively. It has been shown that statins have a greater effect on lowering risk of cardiovascular events in individuals carrying the 299G allele than in those not carrying this allele. We investigated possible mechanisms underlying this synergy of statin treatment and TLR4 genotype.

METHODS AND RESULTS

In cells expressing the 299D-399T TLR4, LPS activated the transcription factor NFkappaB and increased the expression of interleukin-6 and tumor necrosis factor-alpha, and these effects were reduced by pretreatment of the cells with pravastatin or simvastatin. LPS-induced NFkappaB activation and interleukin-6 and tumor necrosis factor-alpha expression were substantially reduced in cell expressing the 299G-399T or 299D-399I variant, and undetectable in cells expressing the 299G-399I TLR4. The 3-hydroxy-3-methylglutaryl coenzyme A pathway inhibitors, Y27632 and GGTI-286, exhibited a similar effect to statins, suggesting that the inhibitory effect of statins was mediated by the 3-hydroxy-3-methylglutaryl coenzyme A pathway.

CONCLUSION

The results of this study indicate that the TLR4 variations and statins have an additive inhibitory effect on TLR4-mediated inflammatory response, providing a potential explanation for the finding that the beneficial effect of statins on cardiovascular risk is dependent on TLR4 genotype.

Impact of previous statin and angiotensin II receptor blocker use on mortality in patients hospitalized with sepsis

STUDY OBJECTIVE

To examine the effect of previous outpatient use of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) and/or angiotensin II receptor blockers (ARBs) on 30-day mortality in patients hospitalized with sepsis.

DESIGN

Retrospective national cohort study.

DATA SOURCE

Department of Veterans Affairs (VA) national patient care and pharmacy databases.

PATIENTS

A total of 3018 patients who were hospitalized with sepsis in fiscal year 2000, had at least 1 year of previous VA outpatient care, and had at least one active and filled VA prescription within 90 days of admission.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was 30-day mortality. The primary analysis was a multilevel model with hospital as a random effect and control variables that included comorbid conditions, demographics, and other drugs. Among the 3018 patients hospitalized with sepsis, mean age was 74.4 years, 2975 (98.6%) were male, and 811 (26.9%) died within 30 days of admission. Regarding prescription drug use, 480 patients (15.9%) were taking statins and 107 (3.5%) were taking ARBs. After adjusting for potential confounders, statin use (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.36-0.64) and ARB use (OR 0.42, 95% CI 0.24-0.76) were significantly associated with decreased 30-day mortality.

CONCLUSIONS

Use of statins and/or ARBs before admission was associated with decreased mortality in patients hospitalized with sepsis. Further research is needed to determine if these drugs might be started on admission for those with sepsis.

Simvastatin stimulates macrophage interleukin-1β secretion through an isoprenylation-dependent mechanism

Statin treatment inhibits oxidized lipoprotein-induced intracellular lipid accumulation (foam cell formation) and reduces plasma levels of inflammatory markers such as interleukin-1beta (IL-1beta). The aim of the present study was to determine if simvastatin affected lipid accumulation in macrophages incubated with aggregated low density lipoproteins (AgLDL) and whether simvastatin had a direct effect on cytokine secretion from macrophages. Simvastatin treatment did not inhibit AgLDL-induced macrophage lipid accumulation, but significantly increased the secretion of IL-1beta and IL-8 from macrophages, whilst inhibiting the secretion of tumor necrosis factor-alpha (TNF-alpha) and having no significant effect on IL-6 secretion. Increased macrophage lipid content did not block statin-induced IL-1beta and IL-8 secretion. Simvastatin-stimulated IL-1beta secretion from macrophages was inhibited by isoprenoids. We therefore hypothesized that simvastatin stimulated IL-1beta secretion by affecting isoprenylation-dependent signaling pathways. Another possible mechanism for affecting such signaling is to impair isoprenoid transfer protein activity with specific inhibitors such as GGTI-297 and FTInhI. This treatment resulted in strong stimulation of IL-1beta secretion that was further enhanced when exogenous IL-1beta was present at the beginning of treatment. These data suggest an isoprenylation-dependent negative-feedback loop for macrophage IL-1beta secretion that is inhibited by statin treatment.

Changes in serum cytokine concentrations during the menopausal transition

OBJECTIVE

The purpose of the present study was to clarify the changes in serum concentrations of 17 cytokines in healthy women during the menopausal transition by using a multiplexed cytokine assay and to clarify the associations of these cytokines with serum estradiol concentration.

METHODS

Sixteen premenopausal, 54 perimenopausal and 52 postmenopausal women were enrolled in this study. Seventeen cytokines in serum samples were measured simultaneously using a Bio-Plex human cytokine 17-Plex assay.

RESULTS

Serum IL-6 concentration showed a weak positive correlation with age (r=0.196, p<0.05). Postmenopausal women for whom less than 5 years had passed since menopause showed significant (p<0.05) increase in serum concentrations of IL-2, GM-CSF and G-CSF, while serum IL-4 concentration was significantly (p<0.05) increased in postmenopausal women for whom more than 5 years had passed since menopause. Serum estradiol concentration showed a significant negative correlation with serum IL-6 concentration and weak negative correlations with serum concentrations of IL-2, IL-8 and GM-CSF.

CONCLUSION

We were able to simultaneously measure the levels of 17 cytokines using a highly sensitive cytokine assay, and we found that the changes in serum cytokine concentrations during the menopausal transition differed. We also found that serum IL-6 concentration during the menopausal transition was negatively correlated with serum estradiol concentration.

LPS-Induced Release of IL-1β, IL-1Ra, IL-6, and TNF-αin Whole Blood from Patients with Familial Hypercholesterolemia: No Effect of Cholesterol-Lowering Treatment

Proinflammatory cytokines, such as interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor-alpha (TNF-alpha), are suggested to have an important role in the process of atherosclerosis. Patients with heterozygous familial hypercholesterolemia (FH) have a marked elevation in the plasma level of low-density lipoproteins (LDL), and they show early development of atherosclerosis. The aim of the present study was to test with a whole blood culture system if hyperlipoproteinemia is associated with increased cytokine production capacity in these patients and if treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors influences this production capacity of blood cells, at both the protein and mRNA levels. The capacity of blood cells in a whole blood culture to produce IL-1beta, IL-6, TNF-alpha, IL-12, IL-18, and IL-1 receptor antagonist (IL-1Ra) in response to lipopolysaccharide (LPS) appeared to be similar for heterozygous FH patients and healthy volunteers. Furthermore, the capacity to produce IL-1beta, IL-6, and TNF-alpha in response to LPS was not modified by cholesterol synthesis inhibitors at the level of mRNA expression or at the level of release. On the other hand, the release of IL-1Ra was significantly increased after treatment with HMG-CoA reductase inhibitors, although only at the protein level. This suggests a possible beneficial anti-inflammatory role for this therapy.

Monocyte Release of Tumor Necrosis Factor-α and Interleukin-1β in Primary Type IIa and IIb Dyslipidemic Patients Treated With Statins or Fibrates

Both 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) as well as peroxisome proliferator-activated receptor (PPAR)alpha activators (fibrates) proved to be effective in the primary and secondary prevention of cardiovascular diseases. The benefits of hypolipemic therapy in cardiovascular diseases cannot be explained only by the lipid-lowering potential of these agents. The aim of this study was to clarify the effect of hypolipemic agents on proinflammatory cytokine release from human monocytes in relationship with their action on plasma levels of sensitive systemic marker of low-grade vascular inflammation. Plasma lipid and high-sensitivity C-reactive protein (hsCRP) levels, and the release of tumor necrosis factor-alpha (TNFalpha) and interleukin-1beta from monocytes were assessed at baseline and 30 and 90 days following randomization of IIa dyslipidemic patients into fluvastatin or simvastatin groups and randomization of type IIb dyslipidemic patients to the micronized form of either ciprofibrate or fenofibrate. Lipopolysaccharide-stimulated monocytes from dyslipidemic patients released significantly more TNFalpha (types IIa and IIb dyslipidemias) and interleukin-1beta (type IIa dyslipidemia) in comparison with monocytes in 59 age-, sex-, and weight-matched control subjects. Their baseline hsCRP levels were also higher. Both statins and fibrates reduced the release of TNFalpha and interleukin-1beta, and lowered plasma hsCRP levels. The effects of hypolipemic agents on cytokine release and plasma hsCRP were unrelated to their lipid-lowering action. Our results have demonstrated that type IIa and IIb dyslipidemic patients exhibit the abnormal pattern of TNFalpha and interleukin-1beta production by activated monocytes. Both HMG-CoA reductase inhibitors and PPARalpha activators normalize monocytic secretion of these cytokines, and this action may partially contribute to the systemic antiinflammatory effect of hypolipemic agents. The statin- and fibrate-induced suppression of proinflammatory cytokine release from monocytes seems to play a role in their beneficial effect on the incidence of cardiovascular events.

The effect of prior statin use on 30-day mortality for patients hospitalized with community-acquired pneumonia

Background

Recent studies suggest that HMG-CoA reductase inhibitors ("statins") may have beneficial effects for patients at risk for some types of infections. We examined the effect of prior outpatient use of statins on mortality for patients hospitalized with community-acquired pneumonia.

Methods

A retrospective cohort study conducted at two tertiary teaching hospitals. Eligible subjects were admitted with a diagnosis of, had a chest x-ray consistent with, and had a discharge ICD-9 diagnosis of pneumonia. Subjects were excluded if they were "comfort measures only" or transferred from another acute care hospital. Subjects were considered to be on a medication if they were taking it at the time of presentation.

Results

Data was abstracted on 787 subjects at the two hospitals. Mortality was 9.2% at 30-days and 13.6% at 90-days. At presentation 52% of subjects were low risk, 34% were moderate risk, and 14% were high risk based on the pneumonia severity index. In the multivariable regression analysis, after adjusting for potential confounders including a propensity score, the use of statins at presentation (odds ratio 0.36, 95% confidence interval 0.14–0.92) was associated with decreased 30-day mortality.

Discussion

Prior outpatient statin use was associated with decreased mortality in patients hospitalized with community-acquired pneumonia despite their use being associated with comorbid illnesses likely to contribute to increased mortality. Confirmatory studies are needed, as well as research to determine the mechanism(s) of this protective effect.

Circulating monocytes in patients with acute coronary syndromes lack sufficient interleukin-10 production after lipopolysaccharide stimulation

Acute coronary syndromes (ACS) are associated with inflammation resulting from monocyte activation. We sought for differences in the production of pro- and anti-inflammatory cytokines by monocytes from patients with ACS. C-reactive protein (CRP) and neopterin were measured in 22 patients with acute coronary syndromes, 50 patients with stable vascular disease and 22 healthy controls. Production of tumour necrosis factor (TNF)-alpha and interleukin (IL)-10 was determined after, respectively, 6 and 24 h of incubation of full blood with lipopolysaccharide (LPS). Levels of CRP [median, interquartile range (IQR)][1.5 mg/l (0.8-4.5) ACS patient versus 2.1 (0.9-3.6) stable disease versus 0.4 (0.3-1.2) healthy controls] (P < 0.001) and neopterin [7.4 nmol/l (6.0-8.7) ACS patient versus 7.1(6.0-8.9) stable disease versus 6.4 (5.6-7.3) healthy controls] (P = 0.07) were higher in both the patient groups. IL-10 production after LPS stimulation was greatly reduced in patients with acute coronary syndromes (16 175 pg/ml, 7559-28 470 pg/ml) as opposed to patients with stable disease (28 379 pg/ml, 12 601-73 968 pg/ml) and healthy controls (63 830 pg/ml, 22 040-168 000 pg/ml) (P = 0.003). TNF-alpha production was not signi fi cantly different between the groups [7313 pg/ml (4740-12 615) ACS patient versus 11 002 (5913-14 190) stable disease versus 8229 (5225-11 364) healthy controls] (P = 0.24). Circulating monocytes in unstable coronary syndromes produce equal amounts of TNF-alpha but less IL-10 after stimulation with LPS in vitro as compared with healthy controls. We hypothesize that, in acute coronary syndromes, the production proinflammatory cytokines is not counterbalanced by anti-inflammatory cytokines such as IL-10.

Reduction of serum C-reactive protein by statin therapy may reflect decreased isoprenylation of Rac-1, a mediator of the IL-6 signal transduction pathway

Recent studies demonstrate that statin therapy decreases plasma levels of C-reactive protein (CRP), a potent risk factor for thrombotic vascular events. CRP is an acute phase reactant, and most circulating CRP is synthesized by hepatocytes in response to IL-6. Since statins do not appear to have a consistent impact on serum levels of IL-6, their impact on plasma CRP very likely reflects down-regulation of hepatocyte responsiveness to this cytokine. The ability of IL-6 to promote transcription of CRP is mediated, in large part, by activation of the transcription factor STAT3; this activation requires both a tyrosine phosphorylation (mediated by the IL-6 receptor complex) and a serine phosphorylation (Ser-727), the origin of which has been more obscure. There is new evidence that, when hepatocytes are exposed to IL-6, the consequent serine phosphorylation of STATS is mediated by a signal transduction pathway in which the G-protein Rac-1 plays an obligate role. Inasmuch as the proper function of Rac-1 is contingent on isoprenylation that anchors it to the plasma membrane, it is reasonable to hypothesize that statin therapy interferes with IL-6 signaling in hepatocytes by suppressing the isoprenylation of Rac-1; a decrease in the transcription of CRP would be a likely consequence of this effect. Whether or not a reduction in elevated CRP is directly beneficial to vascular health, statins can exert direct effects on vascular endothelial function that should help prevent vascular inflammation and thrombosis, and thus should be of particular benefit to subjects - such as those with high CRP levels - who are at high risk for vascular events.

Lovastatin inhibits bone marrow-derived dendritic cell maturation and upregulates proinflammatory cytokine production

Statins are a group of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors which are most effective as lipid lowering agents, and are currently extensively used clinically. Recently, it was also shown that statins affect the immune response. We investigated the effects of lovastatin on the maturation and functional changes of bone marrow-derived dendritic cells (BM-DC). Lovastatin inhibited MHC class II and CD40 expression on DC in a dose-dependent manner, but had lesser effects on CD16, CD80, CD86, and CD11b expression. Nuclear extracts of lovastatin treated DC had decreased NF-kappaB DNA binding activity. Although antigen capture capacity of DC was not affected by lovastatin, the T-cell stimulatory activity of DC was inhibited. Lovastatin up-regulated DC pro-inflammatory cytokine production induced by LPS as measured by intracellular cytokine staining, ELISA and cDNA microarrays. Mevalonate, added in vitro, prevented these effects. These results indicate that lovastatin may inhibit BM-DC maturation and up-regulate cytokine production through a mevalonate dependent pathway, and may cause adverse effects on either innate or adaptive immunity.

Native LDL potentiate TNF alpha and IL-8 production by human mononuclear cells

Native LDL (nLDL) increases expression of adhesion molecules on endothelial cells through induction of Ca(2+) mobilization. Ca(2+) mobilization is also involved in the induction of proinflammatory cytokines, important mediators involved in atherogenesis. The aim of the study was to evaluate the capacity of nLDL to affect spontaneous and lipopolysaccharide (LPS)-stimulated cytokine production. Preincubation of human peripheral blood mononuclear cells (PBMC) with nLDL for 24 h did not influence spontaneous production of tumor necrosis factor alpha (TNF alpha) or interleukin-8 (IL-8), but significantly potentiated LPS-induced production of these cytokines. nLDL preincubation of PBMC did not increase the expression of the LPS receptors Toll-like receptor-4, CD14, or CD11c/CD18. Potentiation of cytokine production by nLDL was mediated through induction of Ca(2+) mobilization, because: a) nLDL induced a sustained pattern of repetitive Ca(2+) transients in human PBMC; b) the Ca(2+) chelator fura 2-acetoxymethyl ester, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, an intracellular Ca(2+) chelator, inhibited the potentiating effect of nLDL on LPS-induced cytokine synthesis; c) induction of Ca(2+) mobilization by thapsigargin potentiated LPS-induced cytokine production. nLDL are able to potentiate LPS-induced production of cytokines by human PBMC, and this effect is probably mediated through induction of Ca(2+) mobilization. This may represent an important pathogenetic mechanism in atherogenesis induced by hyperlipoproteinemia.

Postmenopausal changes in serum cytokine levels and hormone replacement therapy

OBJECTIVE

Our purpose was to investigate the effect of hormone replacement therapy on the postmenopausal changes in serum cytokine levels.

STUDY DESIGN

Fifteen cytokines were measured by an enzyme-linked immunosorbent assay in 97 untreated and hormone replacement-treated women. Thirteen women were examined before and during hormone replacement therapy.

RESULTS

Serum concentrations of macrophage colony-stimulating factor were significantly (P < .05) lower during the early postmenopausal period (< or = 10 years) than the values in premenopause and the elevated levels in the late postmenopausal period (< or = 30 years). A significant increase in tumor necrosis factor alpha and a decline in transforming growth factor beta1 were found in late postmenopausal women. Serum levels of macrophage colony-stimulating factor in women receiving hormone replacement therapy were significantly higher than those in untreated postmenopausal women. Furthermore, hormone replacement therapy induced a significant (P < .01) increase in serum levels of macrophage colony-stimulating factor, whereas serum levels of other cytokines were not affected.

CONCLUSION

It is well documented that macrophage colony-stimulating factor lowers serum cholesterol concentrations and prevents atherosclerosis. Inducing the production of macrophage colony-stimulating factor is a possible additional mechanism of hormone replacement therapy in mediating the antiatherogenic effect.

Stimulation of inflammatory responses in vitro and in vivo by lipophilic HMG-CoA reductase inhibitors

The enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase catalyses the rate limiting step in cholesterol biosynthesis and is markedly inhibited by the statin family of drugs. The effect of statins on lipid lowering is clearly defined, but the ability of the drugs to directly regulate inflammatory functions has not been well explored. In this report, we show that there are differences among the statins in their capacity to induce proinflammatory responses both in human monocytes in vitro, and in leukocytes in mice in vivo. Treatment of human monocytes with lipophilic statins alone stimulated the production of MCP-1, IL-8, TNF-alpha and IL-1 beta and markedly sensitized the cells to subsequent challenge with inflammatory agents. Lipophilic statins also increased the production of reactive oxygen species in monocytes. In contrast, pretreatment of cells with the hydrophilic pravastatin did not induce these heightened inflammatory responses. Furthermore, treatment of mice with lipophilic statins caused a markedly higher influx of leukocytes into the inflamed peritoneal cavity following challenge with thioglycollate. Overall, these results demonstrate that the lipophilic statins influence a regulatory pathway in monocytes that controls cytokine production and that the statins induce different pro-inflammatory responses both in vitro and in vivo.

Hydroxymethylglutaryl coenzyme A reductase inhibitors modify the inflammatory response of human macrophages and endothelial cells infected with Chlamydia pneumoniae

BACKGROUND

In patients with atherosclerosis, hepatic hydroxymethylglutaryl coenzyme A reductase (CSE) inhibitors may reduce the activation of inflammation. Because Chlamydia pneumoniae infection has been linked to coronary artery disease through the induction of plaque inflammation, we investigated whether cerivastatin affects the infection rate of human macrophages and endothelial cells (ECs) and their proinflammatory activation after chlamydial infection.

METHODS AND RESULTS

Macrophages were collected from the alveolar compartment of 6 volunteers and 10 patients with chronic bronchitis. ECs were obtained from 10 umbilical cords. The C. pneumoniae strain CWL was incubated with macrophages or ECs in the presence and absence of the CSE inhibitor cerivastatin. The infection rate was determined by immunofluorescence microscopy. The release of monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), and tumor necrosis factor (TNF)-alpha was quantified by ELISA. The release of oxygen radicals was determined by ferricytochrome assay. Infection rates were tendentially lower after the preincubation of macrophages with CSE inhibitors (17.2% versus 9. 3% and 18.2% versus 10.4%, respectively; P=NS). The secretion of MCP-1, IL-8, and TNF-alpha by infected macrophages from volunteers increased. Coincubation with cerivastatin resulted in significantly lower MCP-1 and IL-8 production, whereas the release of TNF-alpha remained unaffected. Similar effects regarding chemokine release were observed in ECs.

CONCLUSIONS

CSE inhibitors modify the inflammatory response of human immune cells to C. pneumoniae. This finding could be relevant for the therapeutic potential of CSE statins in patients with atherosclerosis and C. pneumoniae infection.

Hyperlipoproteinemia affects cytokine production in whole blood samples ex vivo. The influence of lipid-lowering therapy

Low-density lipoprotein (LDL)-receptor deficient mice, thus hypercholesterolemic, combine protection against infection with an ex vivo two- to threefold higher pro-inflammatory cytokine production in macrophages. A pro-inflammatory cytokine profile ex-vivo is also associated with survival of gram-negative sepsis in man. We hypothesized that high lipoprotein levels would be associated with a pro-inflammatory cytokine production and could explain the resistance to fatal infection. We treated 10 patients with familial hypercholesterolemia (FH) with HMG-CoA reductase inhibitors, and 13 patients with endogenous hypertriglyceridemia (HTG) with fibrates. Blood samples were stimulated ex vivo with lipopolysaccharide (LPS), to assess the cytokine production capacity. FH patients had significantly lower tumor necrosis factor-alpha (TNF-alpha) production, compared to normolipidemic controls (P=0. 001). Lipid lowering treatment in FH patients did not affect TNF-alpha production. HTG patients showed significantly higher TNF-alpha production at baseline than matched normolipidemic controls (P<0.001), while lowering of serum triglycerides in these patients resulted in a significant decrease in TNF-alpha production (P=0.019). The IL-10 production was not affected. These data refute our hypothesis that high LDL-cholesterol levels are associated with a pro-inflammatory cytokine production capacity. In contrast, the study suggests that very-low-density lipoprotein (VLDL) in hypertriglyceridemic patients augments TNF-alpha production.

Low-density lipoprotein-independent effects of statins

Statins have pleiotropic properties that complement their cholesterol-lowering effects. These properties may partly account for their established benefit in the prevention of coronary artery disease beyond the reduction of LDL-cholesterol levels. The most widely recognized properties are reviewed here. They include: (i) nitric oxide-mediated improvement of endothelial dysfunction and upregulation of endothelin-1 expression; (ii) antioxidant effects; (iii) anti-inflammatory properties; (iv) inhibition of cell proliferation with anticarcinogenic actions in animals; (v) stabilization of atherosclerotic plaques; (vi) anticoagulant effects; and (vii) inhibition of graft rejection after heart and kidney transplantation. As advances are made in our knowledge, new properties are steadily being uncovered. Pleiotropic effects are currently being given consideration when instituting combination therapy for patients at high cardiovascular risk. Some pleiotropic effects are negative, and may account for occasional untoward drug interactions. For many of these new properties, the clinical relevance has not been established. The challenge for the future will be to design and carry out appropriate clinical trials to establish their relative importance in the prevention of coronary artery disease.

Lipopolysaccharide-activated macrophages stimulate the synthesis of collagen type I and C-fibronectin in cultured pancreatic stellate cells

We have recently identified and characterized pancreatic stellate cells (PSC) in rats and humans (Gastroenterology 1998, 15:421-435). PSC are suggested to represent the main cellular source of extracellular matrix in chronic pancreatitis. Now we describe a paracrine stimulatory loop between human macrophages and PSC (rat and human) that results in an increased extracellular matrix synthesis. Native and transiently acidified supernatants of cultured macrophages were added to cultured PSC in the presence of 0.1% fetal calf serum. Native supernatants of lipopolysaccharide-activated macrophages stimulated the synthesis of collagen type I 1.38 +/- 0.09-fold of control and c-fibronectin 1.89 +/- 0.18-fold of control. Transiently acidified supernatants stimulated collagen type I and c-fibronectin 2.10 +/- 0.2-fold and 2.80 +/- 0.05-fold of control, respectively. Northern blot demonstrated an increased expression of the collagen-I-(alpha-1)-mRNA and fibronectin-mRNA in PSC 10 hours after addition of the acidified macrophage supernatants. Cell proliferation measured by bromodeoxyuridine incorporation was not influenced by the macrophage supernatants. Unstimulated macrophages released 1.97 pg TGFbeta1/microgram of DNA over 24 hours and lipopolysaccharide-activated macrophages released 6.61pg TGFbeta1/microgram of DNA over 24 hours. These data together with the results that, in particular, transiently acidified macrophage supernatants increased matrix synthesis, identify TGFbeta as the responsible mediator. In conclusion, our data demonstrate a paracrine stimulation of matrix synthesis of pancreatic stellate cells via TGFbeta1 released by activated macrophages. We suggest that macrophages might play a pivotal role in the development of pancreas fibrosis.

LPS-induced cytokine production and expression of beta2-integrins and CD14 by peripheral blood mononuclear cells of patients with homozygous familial hypercholesterolemia

It has been suggested that proinflammatory cytokines such as tumor necrosis factor-alpha (TNF) and interleukin-1beta (IL-1), as well as adhesion molecules such as beta2-integrins and CD14, play a role in the pathogenesis of atherosclerosis. Familial hypercholesterolemia (FH) is an autosomal disease in which defective or absent LDL receptors are the cause for extreme LDL concentrations and early development of atherosclerosis. We studied lipopolysaccharide-induced cytokine production and the expression of adhesion molecules by mononuclear cells of three homozygous FH patients and compared them with first-degree relatives and healthy controls. There was a tendency towards increased cytokine production by cells of FH patients, whereas the expression of adhesion molecules was not modified compared to controls. In addition, LDL-apheresis inhibited IL-1 and TNF production and the expression of CD11a, CD11b, CD11c and CD14 by the mononuclear cells of FH patients and this may be an additional beneficial effect of LDL-apheresis apart of decreasing LDL concentrations.