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

Familial hypercholesterolaemia and COVID-19: A two-hit scenario for endothelial dysfunction amenable to treatment

Patients with familial hypercholesterolemia (FH) are likely at increased risk for COVID-19 complications in the acute phase of the infection, and for a long time thereafter. Because in FH patients the level of low density lipoprotein cholesterol (LDL-C) is elevated from birth and it correlates with the degree of systemic endothelial dysfunction, both heterozygous FH (HeFH) patients and, in particular, homozygous FH (HoFH) patients have a dysfunctional endothelium prone to further damage by the direct viral attack and the hyper-inflammatory reaction typical of severe COVID-19. Evidence to date shows the benefit of statin use in patients with COVID-19. In FH patients, the focus should therefore be on the effective lowering of LDL-C levels, the root cause of the expected excess vulnerability to COVID-19 infection in these patients. Moreover, the ongoing use of statins and other lipid-lowering therapies should be encouraged during the COVID pandemic to mitigate the risk of cardiovascular complications from COVID-19. For the reduction of the excess risk in FH patients with COVID-19, we advocate stringent adherence to the guideline determined LDL-C levels for FH patients, or maybe even to lower levels. Unfortunately, epidemiologic data are lacking on the severity of COVID-19 infections, as well as the number of acute cardiac events that have occurred in FH subjects during the COVID-19 pandemic. Such data need to be urgently gathered to learn how much the risk for, and the severity of COVID-19 in FH are increased.

Protective Effects of Gynostemma pentaphyllum (var. Ginpent) against Lipopolysaccharide-Induced Inflammation and Motor Alteration in Mice

Gynostemma pentaphyllum (var. Ginpent) (GP) is a variety of Cucurbit with anti-inflammatory and antioxidant effects in patients. In this manuscript, the main components present in the dry extract of GP have been identified using Ultra High Performance Liquid Chromatography quadrupole-time-of-flight mass spectrometry (UHPLC/Q-TOF-MS). In addition, the anti-inflammatory action of GP was evaluated in animal models with acute peripheral inflammation and motor alteration induced by lipopolysaccharide. The results showed that GP dry extract is rich in secondary metabolites with potential antioxidant and anti-inflammatory properties. We found that the treatment with GP induced a recovery of motor function measured with the rotarod test and pole test, and a reduction in inflammatory cytokines such as interleukin-1β and interleukin-6 measured with the ELISA test. The data collected in this study on the effects of GP in in vivo models may help integrate the therapeutic strategies of inflammatory-based disorders.

Elevated Circulating Th2 Cells in Women With Asthma and Psychological Morbidity: A New Asthma Endotype?

PURPOSE

Psychological stress shifts the immune system toward the production of T-helper (Th)-2-mediated cytokines and eosinophilia, increases the risks for both asthma and depression, and can precipitate asthma exacerbations. Th2-mediated inflammation is a characteristic of allergic asthma. We have shown that the levels of CD4⁺ Th2 cells in the peripheral blood of patients with asthma are associated with severity and/or control of the disease. To improve our understanding of the interactions between stress and asthma symptoms, we evaluated the effects of psychological comorbidity on Th2-mediated inflammation in patients with asthma.

METHODS

Sixty-six asthmatic patients were recruited from the University of Alberta Asthma Clinic after they gave informed consent. Stress-related effects on asthma and psychological morbidity were assessed using the Asthma Control Questionnaire, completed by the patients at recruitment. Venous blood was collected at recruitment and Th2-mediated immunity evaluated by flow cytometry, quantitative real-time reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay.

FINDINGS

Patients with stress-triggered asthma (n = 12) had higher percentage of CD4⁺ T cells (P = 0.006) and Th2 cells (CD4⁺CRTh2⁺ T cells; P = 0.002) in peripheral blood compared to patients with asthma who did not experience stress-related worsening of disease (n = 54). The same was true when we analyzed patients with any form of psychological comorbidity (n = 19) compared to those without psychological comorbidities (n = 47). These differences were evident among women, but not among men. Women with psychological comorbidity also required higher doses of inhaled and oral corticosteroids compared to those without psychological comorbidity.

IMPLICATIONS

Asthma involving psychological morbidity associates with an elevated level of circulating Th2 cells and increased corticosteroid usage, and may be more prevalent in women. Larger-scale prospective studies are required for assessing whether these women constitute a new endotype of Th2-high asthma responsive to treatments aimed to improve psychological comorbidities.

The differential statin effect on cytokine production of monocytes or macrophages is mediated by differential geranylgeranylation-dependent Rac1 activation

Monocytes and macrophages contribute to pathogenesis of various inflammatory diseases, including auto-inflammatory diseases, cancer, sepsis, or atherosclerosis. They do so by production of cytokines, the central regulators of inflammation. Isoprenylation of small G-proteins is involved in regulation of production of some cytokines. Statins possibly affect isoprenylation-dependent cytokine production of monocytes and macrophages differentially. Thus, we compared statin-dependent cytokine production of lipopolysaccharide (LPS)-stimulated freshly isolated human monocytes and macrophages derived from monocytes by overnight differentiation. Stimulated monocytes readily produced tumor necrosis factor-α, interleukin-6, and interleukin-1β. Statins did not alter cytokine production of LPS-stimulated monocytes. In contrast, monocyte-derived macrophages prepared in the absence of statin lost the capacity to produce cytokines, whereas macrophages prepared in the presence of statin still produced cytokines. The cells expressed indistinguishable nuclear factor-kB activity, suggesting involvement of separate, statin-dependent regulation pathways. The presence of statin was necessary during the differentiation phase of the macrophages, indicating that retainment-of-function rather than costimulation was involved. Reconstitution with mevalonic acid, farnesyl pyrophosphate, or geranylgeranyl pyrophosphate blocked the retainment effect, whereas reconstitution of cholesterol synthesis by squalene did not. Inhibition of geranylgeranylation by GGTI-298, but not inhibition of farnesylation or cholesterol synthesis, mimicked the retainment effect of the statin. Inhibition of Rac1 activation by the Rac1/TIAM1-inhibitor NSC23766 or by Rac1-siRNA (small interfering RNA) blocked the retainment effect. Consistent with this finding, macrophages differentiated in the presence of statin expressed enhanced Rac1-GTP-levels. In line with the above hypothesis that monocytes and macrophages are differentially regulated by statins, the CD14/CD16-, merTK-, CX₃CR1-, or CD163-expression (M2-macrophage-related) correlated inversely to the cytokine production. Thus, monocytes and macrophages display differential Rac1-geranylgeranylation-dependent functional capacities, that is, statins sway monocytes and macrophages differentially.

Inflammatory cytokines shape a changing DNA methylome in monocytes mirroring disease activity in rheumatoid arthritis

Objective

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that mainly targets joints. Monocytes and macrophages are critical in RA pathogenesis and contribute to inflammatory lesions. These extremely plastic cells respond to extracellular signals which cause epigenomic changes that define their pathogenic phenotype. Here, we interrogated how DNA methylation alterations in RA monocytes are determined by extracellular signals.

Methods

High-throughput DNA methylation analyses of patients with RA and controls and in vitro cytokine stimulation were used to investigate the underlying mechanisms behind DNA methylation alterations in RA as well as their relationship with clinical parameters, including RA disease activity.

Results

The DNA methylomes of peripheral blood monocytes displayed significant changes and increased variability in patients with RA with respect to healthy controls. Changes in the monocyte methylome correlate with DAS28, in which high-activity patients are divergent from healthy controls in contrast to remission patients whose methylome is virtually identical to healthy controls. Indeed, the notion of a changing monocyte methylome is supported after comparing the profiles of same individuals at different stages of activity. We show how these changes are mediated by an increase in disease activity-associated cytokines, such as tumour necrosis factor alpha and interferons, as they recapitulate the DNA methylation changes observed in patients in vitro.

Conclusion

We demonstrate a direct link between RA disease activity and the monocyte methylome through the action of inflammation-associated cytokines. Finally, we have obtained a DNA methylation-based mathematical formula that predicts inflammation-mediated disease activity for RA and other chronic immune-mediated inflammatory diseases.

An ex vivo ruminal ovine model to study the immediate immune response in the context of bacterial lipopolysaccharide

We have set up an ex vivo ovine ruminal model, which can mimic the multicellular process to explore the early steps in Salmonella typhimurium lipopolysaccharide (LPS) stimulation using RNA-seq technology. Ovine ruminal explants were collected for histological and transcriptional analysis and supernatants collected to quantitate lactate dehydrogenase (LDH) enzymes. A total of 8 and 523 genes were significantly over-expressed between LPS-treated and control tissues at 6 and 12 h, respectively. However, six and seven hundred and thirteen genes were substantially repressed between the aforementioned tissues, correspondingly. Key genes up-regulated in response to the addition of LPS were tumor necrosis factor (TNF), interlukin (IL)-1 beta(b), IL-6, IL-8, IL-17B, IL-19, MMP-1, MMP-3, and integrin alpha 2 (ITGA8, 9). This study shows for the first time that galectin-1 is up-regulated in an ex vivo ruminal segment model exposed to bacterial lipopolysaccharide following 6 h of incubation. The ruminal segment model has been shown to be a suitable tool to study the bacterial lipopolysaccharide effects on the ovine ruminal tissues prior to in vivo assessment.

Lack of interaction of lopinavir solid drug nanoparticles with cells of the immune system

AIM

We previously demonstrated that solid drug nanoparticles (SDNs) lopinavir (LPV) dispersed into aqueous media display favorable pharmacokinetics.

METHODS

The impact of LPV SDNs on the function and phenotype of primary human T cells and macrophages (primary sites of HIV replication) was investigated.

RESULTS

LPV significantly increased IL-1β (ninefold higher than untreated cells; p = 0.045) and TNF-α (sixfold higher than untreated cells; p = 0.018) secretion from monocyte-derived macrophages, whereas LPV SDNs did not elicit these responses at comparable drug concentrations. LPV SDNs were demonstrated to be immunologically inert to human T cells and monocyte-derived macrophages.

CONCLUSION

The LPV SDN was demonstrated to exhibit comparable, or favorable behavior compared with an LPV aqueous solution in the employed biocompatibility assessments.

Synergistic Interaction Between Phage Therapy and Antibiotics Clears Pseudomonas Aeruginosa Infection in Endocarditis and Reduces Virulence

Background.

Increasing antibiotic resistance warrants therapeutic alternatives. Here we investigated the efficacy of bacteriophage-therapy (phage) alone or combined with antibiotics against experimental endocarditis (EE) due to Pseudomonas aeruginosa, an archetype of difficult-to-treat infection.

Methods.

In vitro fibrin clots and rats with aortic EE were treated with an antipseudomonas phage cocktail alone or combined with ciprofloxacin. Phage pharmacology, therapeutic efficacy, and resistance were determined.

Results.

In vitro, single-dose phage therapy killed 7 log colony-forming units (CFUs)/g of fibrin clots in 6 hours. Phage-resistant mutants regrew after 24 hours but were prevented by combination with ciprofloxacin (2.5 × minimum inhibitory concentration). In vivo, single-dose phage therapy killed 2.5 log CFUs/g of vegetations in 6 hours (P < .001 vs untreated controls) and was comparable with ciprofloxacin monotherapy. Moreover, phage/ciprofloxacin combinations were highly synergistic, killing >6 log CFUs/g of vegetations in 6 hours and successfully treating 64% (n = 7/11) of rats. Phage-resistant mutants emerged in vitro but not in vivo, most likely because resistant mutations affected bacterial surface determinants important for infectivity (eg, the pilT and galU genes involved in pilus motility and LPS formation).

Conclusions.

Single-dose phage therapy was active against P. aeruginosa EE and highly synergistic with ciprofloxacin. Phage-resistant mutants had impaired infectivity. Phage-therapy alone or combined with antibiotics merits further clinical consideration.

Obesity-associated cancer risk: the role of intestinal microbiota in the etiology of the host proinflammatory state

Obesity increases the risks of many cancers. One important mechanism behind this association is the obesity-associated proinflammatory state. Although the composition of the intestinal microbiome undoubtedly can contribute to the proinflammatory state, perhaps the most important aspect of host-microbiome interactions is host exposure to components of intestinal bacteria that stimulate inflammatory reactions. Systemic exposures to intestinal bacteria can be modulated by dietary factors through altering both the composition of the intestinal microbiota and the absorption of bacterial products from the intestinal lumen. In particular, high-fat and high-energy diets have been shown to facilitate absorption of bacterial lipopolysaccharide (LPS) from intestinal bacteria. Biomarkers of bacterial exposures that have been measured in blood include LPS-binding protein, sCD14, fatty acids characteristic of intestinal bacteria, and immunoglobulins specific for bacterial LPS and flagellin. The optimal strategies to reduce these proinflammatory exposures, whether by altering diet composition, avoiding a positive energy balance, or reducing adipose stores, likely differ in each individual. Biomarkers that assess systemic bacterial exposures therefore should be useful to (1) optimize and personalize preventive approaches for individuals and groups with specific characteristics and to (2) gain insight into the possible mechanisms involved with different preventive approaches.

Major involvement of bacterial components in rheumatoid arthritis and its accompanying oxidative stress, systemic inflammation and hypercoagulability

We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of "coherence," that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.

The Expression of CD14(+)CD16(+) Monocyte Subpopulation in Coronary Heart Disease Patients with Blood Stasis Syndrome

Blood stasis syndrome (BSS), a comprehensive pathological state, is one of the traditional Chinese medicine syndromes of coronary heart disease (CHD). In our previous study, we investigated that Fc γ RIIIA (also called CD14(+)CD16(+) monocyte subpopulation) is one of the differentially expressed genes related to CHD patients and its possible role in the atherosclerotic formation and plaque rupture. However, whether or not the deregulation of CD14(+)CD16(+) monocyte subpopulation expression is implicated in the pathogenesis of CHD patients with BSS has not yet been elucidated. In this study, we found that there was no significant difference between CHD patients with BSS and non-BSS in CD14(+)CD16(+) monocyte subpopulation at gene level. Moreover, the protein level of CD14(+)CD16(+) monocyte subpopulation in CHD patients with BSS was increased significantly when compared to the CHD patients with non-BSS. Additionally, the level of inflammatory cytokines downstream of CD14(+)CD16(+) monocyte subpopulation such as TNF- α and IL-1 in sera was much higher in CHD patients with BSS than that in CHD patients with non-BSS. Taken together, these results indicated that CD14(+)CD16(+) monocyte subpopulation was implicated in the pathogenesis of CHD patients with BSS, which may be one of the bases of the essence of BSS investigation.

Melatonin suppresses proinflammatory mediators in lipopolysaccharide-stimulated CRL1999 cells via targeting MAPK, NF-κB, c/EBPβ, and p300 signaling

Melatonin is an indoleamine secreted by the pineal gland as well as a plant-derived product that exerts potential anti-inflammatory properties, but the mechanisms of action remain unclear. Here, we investigated the roles of melatonin in regulation of proinflammatory mediators and identified the underlying mechanisms in human vascular smooth muscle (VSM) cell line CRL1999 stimulated by lipopolysaccharide (LPS). We found that treatment with melatonin significantly inhibited the production and expression of TNF-α and interleukin (IL)-1β, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase, prostaglandin E(2) (PGE2), and nitric oxide (NO) in a dose-dependent manner. Moreover, we also found that the suppression of proinflammatory mediators by melatonin was mediated through inhibition of MAPK, NF-κB, c/EBPβ, and p300 signaling in LPS-stimulated CRL1999 cells. Treatment with melatonin markedly inhibited phosphorylation of ERK1/2, JNK, p38 MAPK, IκB-α, and c/EBPβ, blocked binding of NF-κB and c/EBPβ to promoters, and suppressed p300 histone acetyltransferase (HAT) activity and p300 HAT-mediated NF-κB acetylation. Transfection with an ERK-, IκB-, or c/EBPβ-specific siRNA or pretreatment with an ERK-, p38 MAPK-, or p300-selective inhibitor considerably abrogated the melatonin-mediated inhibition of proinflammatory mediators. Conversely, exogenous overexpression of a constitutively active p300, but not its HAT mutant, effectively reversed the melatonin-mediated inhibitions. Collectively, these results indicate that melatonin suppresses proinflammatory mediators by simultaneously targeting the multiple signaling such as ERK/p38 MAPK, c/EBPβ, NF-κB, and p300, in LPS-stimulated VSM cell line CRL1999, and suggest that melatonin is a potential candidate compound for the treatment of proinflammatory disorders.

Early statin use is associated with increased risk of infection after stroke

BACKGROUND

Infection after stroke is common and likely detrimental. Given the potent immunomodulatory properties of statins, we hypothesized that early statin use might increase the risk of infection in the immediate post stroke period.

METHODS

In a study cohort of 112 patients with ischemic stroke, we assessed the impact of early statin use on the risk of post stroke infection.

RESULTS

After controlling for stroke severity and patient age, the odds ratio (OR) and 95% confidence interval (CI) for infection in the first 15 days after stroke among patients on a statin by day 3 after stroke was 7.21 (95% CI 1.40-37.98; P = .018). When controlling for univariate predictors of infection, the OR associated for infection associated with statin use actually increased, but was no longer significant (8.49 [95% CI 0.92-77.98]; P = .059). In addition, early statin use was associated with an increase in plasma interleukin-1 receptor antagonist (IL-1ra); IL-1ra was significantly higher in early statin users than in nonstatin users by day 7 after stroke.

CONCLUSIONS

Our data suggest that early statin use appears to be associated with and increased risk of post stroke infection. This risk may, in part, be related to increases in plasma IL-1ra. If these findings are replicated in larger studies, they could have important implications for the timing of statin therapy after stroke.

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.

Sensitivity of mice to lipopolysaccharide is increased by a high saturated fat and cholesterol diet

Background

It was hypothesized that a pro-atherogenic, high saturated fat and cholesterol diet (HCD) would increase the inflammatory response to E. coli endotoxin (LPS) and increase its concentration in plasma after administration to mice.

Methods

C57Bl/6 mice were fed a HCD or a control diet (CD) for 4 weeks, and then treated with saline, 0.5, 1 or 2 mg LPS/kg, ip. Liver injury (alanine:2-oxoglutarate aminotransferase and aspartate aminotransferase, collagen staining), circulating cytokines (tumor necrosis factor-α, interleukin-6 and interferon-γ), factors that can bind LPS (serum amyloid A, apolipoprotein A1, LPS binding protein, and CD14), and plasma levels of LPS were measured. The hepatic response was assessed by measuring vascular cell adhesion molecule (VCAM)-1, inducible nitric oxide synthase (iNOS) and signal transducer and activator of transcription-1 proteins, and VCAM-1 and iNOS mRNAs. Hepatic mRNA encoding the LPS receptor, Toll like receptor 4, was also determined.

Results

Two mg LPS/kg killed 100% of mice fed HCD within 5 d, while no mice fed CD died. All mice treated with 0 to 1 mg LPS/kg survived 24 h. HCD increased plasma alanine:2-oxoglutarate aminotransferase and aspartate aminotransferase, and the enzymes were increased more by LPS in HCD than CD mice. Induction of plasma tumor necrosis factor-α, interleukin-6, and interferon-γ by LPS was greater with HCD than CD. Hepatic VCAM-1 and iNOS protein and mRNA were induced by LPS more in mice fed HCD than CD. Tyrosine phosphorylation of signal transducer and activator of transcription-1 caused by LPS was prolonged in HCD compared with CD mice. Despite the hepatic effects of HCD, diet had no effect on the LPS plasma concentration-time profile. HCD alone did not affect circulating levels of plasma apolipoprotein A1 or LPS binding protein. However, plasma concentrations of serum amyloid A and CD14, and hepatic toll-like receptor-4 mRNA were increased in mice fed HCD.

Conclusion

HCD increased the sensitivity of mice to LPS without affecting its plasma level. Although increased serum amyloid A and CD14 in the circulation may inhibit LPS actions, their overexpression, along with hepatic toll-like receptor-4 or other factors, may contribute to the heightened sensitivity to LPS.