Decreased high-density lipoprotein cholesterol level is an independent correlate of circulating tumor necrosis factor-alpha in a general population

Exercise: Just What the Doctor Ordered, But Why? Elucidating Mechanisms for Women's Increased High-Density Lipoprotein Benefit From Exercise and for the Health ABC Study

High-density lipoprotein (HDL) is protective against cardiovascular disease. Exercise can increase HDL concentration, and some evidence suggests that this effect occurs more strongly in women than in men. Both HDL and exercise are associated with inflammation. We hypothesized a sex-by-exercise interaction on HDL level, whereby women would benefit from exercise more strongly than men, and tumor necrosis factor alpha and serum soluble tumor necrosis factor receptor-2 would mediate this relationship. This study included 2,957 older adult participants (1,520 women; 41% Black, 59% White; 73.6-years-old) from the Health, Aging, and Body Composition study. Regression models revealed a positive exercise-HDL relationship in women only (sex-by-exercise interaction: β = 0.09, p = .013; exercise on HDL in women: β = 0.07, p = .015), mediated by TNFα (axb = 0.15; CI: 0.01, 0.30), suggesting that exercise may increase HDL levels in women through reduced inflammation. Given that vascular risk contributes to Alzheimer's disease risk, findings have implications for sex differences in AD risk factors.

Alkamides from Tropaeolum tuberosum inhibit inflammatory response induced by TNF-α and NF-κB

ETHNO-PHARMACOLOGICAL RELEVANCE

Tropaeolum tuberosum, commonly known as "Mashua", is one of the plants most frequently used by Andean (Peruvian-Bolivian) people as food and medicine. It is used as a remedy against a wide range of diseases, especially those related with inflammation.

OBJECTIVES

This study aims to identify compounds active against inflammatory related conditions.

MATERIALS AND METHODS

A bioassay-guided isolation of anti-inflammatory compounds from black and purple tubers of T. tuberosum was performed measuring TNF-α and NF-κB production in THP-1 monocytic cells.

RESULTS

The bioassay-guided isolation led to one active compound from purple T. tuberosum, N-oleoyldopamine (1), and another active compound from black T. tuberosum, N-(2-Hydroxyethyl)-7Z,10Z,13Z,16Z-docosatetraenamide (2). Both compounds displayed anti-TNF-α activity with IC₅₀ values of 3.12 ± 0.19 μM and 1.56 ± 0.15 μM, respectively. Also, both compounds suppressed NF-κB with IC₅₀ of 3.54 ± 0.02 μM and 1.77 ± 0.07 μM, respectively.

CONCLUSIONS

We identified bioactive compounds from purple and black Tropaeolum tuberosum responsible for their anti-inflammatory activity: N-oleoyldopamine (1) and N-(2-Hydroxyethyl)-7Z,10Z,13Z,16Z-docosatetraenamide (2). This is the first report which isolates these compounds from T. tuberosum and describes their anti-inflammatory activities.

The inflammatory effects of TNF-α and complement component 3 on coagulation

Tissue necrosis factor-α (TNF-α) and complement component 3 (C3) are two well-known pro-inflammatory molecules. When TNF-α is upregulated, it contributes to changes in coagulation and causes C3 induction. They both interact with receptors on platelets and erythrocytes (RBCs). Here, we look at the individual effects of C3 and TNF-α, by adding low levels of the molecules to whole blood and platelet poor plasma. We used thromboelastography, wide-field microscopy and scanning electron microscopy to study blood clot formation, as well as structural changes to RBCs and platelets. Clot formation was significantly different from the naïve sample for both the molecules. Furthermore, TNF-α exposure to whole blood resulted in platelet clumping and activation and we noted spontaneous plasma protein dense matted deposits. C3 exposure did not cause platelet aggregation, and only slight pseudopodia formation was noted. Therefore, although C3 presence has an important function to cause TNF-α release, it does not necessarily by itself cause platelet activation or RBC damage at these low concentrations. We conclude by suggesting that our laboratory results can be translated into clinical practice by incorporating C3 and TNF-α measurements into broad spectrum analysis assays, like multiplex technology, as a step closer to a patient-orientated, precision medicine approach.

High-density lipoprotein-cholesterol levels and risk of cancer in HIV-infected subjects: Data from the ICONA Foundation Cohort

Investigation of the relationship between high-density lipoprotein-cholesterol (HDL-c) and the risk of developing cancer in a prospective cohort of human immunodeficiency virus (HIV)-infected patients.The Italian Cohort of Antiretroviral-naïve Patients Foundation Cohort is an Italian multicenter observational study recruiting HIV-positive patients while still antiretroviral treatment-naïve, regardless of the reason since 1997.Patients with at least 1 HDL-c value per year since enrollment and one such value before antiretroviral treatment initiation were included. HDL-c values were categorized as either low (<39 mg/dL in males or <49 mg/dL in females) or normal. Cancer diagnoses were classified as AIDS-defining malignancies (ADMs) or non-AIDS-defining malignancies (NADMs). Kaplan-Meier curves and Cox proportional-hazards regression models were used.Among 4897 patients (13,440 person-years of follow-up [PYFU]), 104 diagnoses of cancer were observed (56 ADMs, 48 NADMs) for an overall incidence rate of 7.7 (95% confidence interval [CI] 6.3-9.2) per 1000 PYFU.Low HDL-c values at enrollment were associated with higher risk both of cancer (crude hazard ratio [HR] 1.72, 95% CI 1.16-2.56, P = 0.007) and of NADM (crude HR 2.50, 95% CI 1.35-4.76, P = 0.003). Multivariate analysis showed that the risk of cancer diagnosis was higher in patients with low HDL-c values (adjusted HR [AHR] 1.87, 95% CI 1.18-2.95, P = 0.007) in older patients, those patients more recently enrolled, and in those with low current cluster of differentiation 4+ levels, and/or high current HIV-ribonucleic acid.The multivariate model confirmed an association between HDL-c (AHR 2.61, 95% CI 1.40-4.89, P = 0.003) and risk of NADM.Low HDL-c is an independent predictor of cancer in HIV-1-infected subjects.

Shared genetic variants between serum levels of high-density lipoprotein cholesterol and wheezing in a cohort of children from Cyprus

Background

In a cohort of children in Cyprus, we recently reported low levels of high density lipoprotein cholesterol (HDL-C) to be associated with asthma. We examined whether genetic polymorphisms that were previously linked individually to asthma, obesity, or HDL-C are associated with both asthma and HDL-C levels in the Cyprus cohort.

Methods

We assessed genotypes frequencies in current-wheezers (n = 190) and non-asthmatic controls (n = 671) and HDL-C levels across several genotypes. Binary logistic regression models were used to assess the effect of genotypes on wheezing risk and examined whether this effect is carried out through changes of HDL–C.

Results

Of the 16 polymorphisms tested, two polymorphisms TNFa rs3093664 and PRKCA rs9892651 presented significant differences in genotype distribution among current-wheezers and controls. Higher HDL-C levels were noted in carriers of genotype GG of polymorphism TNFa rs3093664 that was protective for wheezing Vs AG and AA genotypes (65.3 Vs 51.8 and 53.3 mg/dl, p-value < 0.001 and p-value for trend = 0.028). In polymorphism PRKCA rs9892651, HDL-C levels were lower in carriers of CC and TC genotypes that were more frequent in current-wheezers Vs TT genotype (52.2 and 52.7 Vs 55.2 mg/dl, p-value = 0.042 and p-value for trend = 0.02). The association of TNFa rs3093664 with wheezing is partly mediated by its effect on HDL-C whereas association of PRKCA rs9892651 with wheezing appeared to be independent of HDL-C.

Conclusions

We found evidence that two SNPs located in different genetic loci, are associated with both wheezing and HDL-C levels, although more studies in other populations are needed to confirm our results.

Electronic supplementary material

The online version of this article (doi:10.1186/s13052-016-0276-1) contains supplementary material, which is available to authorized users.

Inhibition of cholesteryl ester transfer protein by anacetrapib does not impair the anti-inflammatory properties of high density lipoprotein

Cholesteryl ester transfer protein (CETP) is a target of therapeutic intervention for coronary heart disease. Anacetrapib, a potent inhibitor of CETP, has been shown to reduce LDL-cholesterol by 40% and increase HDL-cholesterol by 140% in patients, and is currently being evaluated in a phase III cardiovascular outcomes trial. HDL is known to possess anti-inflammatory properties, however with such large increases in HDL-cholesterol, it is unclear whether CETP inhibition perturbs HDL functionality such as anti-inflammatory effects on endothelial cells. The purpose of the present study was to determine whether CETP inhibition by anacetrapib affects the anti-inflammatory properties of HDL. HDL was isolated from either hamsters treated with vehicle or anacetrapib for 2weeks, or from normal human subjects treated either placebo, 20mg, or 150mg anacetrapib daily for 2weeks. Anacetrapib treatment increased plasma HDL cholesterol levels by 65% and between 48 and 82% in hamsters and humans, respectively. Pre-incubation of human aortic endothelial cells with HDL isolated from both control and anacetrapib treated hamsters suppressed TNFα induced expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin. Similar results were obtained with human HDL samples pre and post treatment with placebo or anacetrapib. Further, HDL inhibited TNFα-induced MCP-1 secretion, monocyte adhesion and NF-κB activation in endothelial cells, and the inhibition was similar between control and anacetrapib treated groups. These studies demonstrate that anacetrapib treatment does not impair the ability of HDL to suppress an inflammatory response in endothelial cells.

Factors associated with inflammation markers, a cross-sectional analysis

Epidemiological studies have reported associations between circulating inflammation markers and risk of chronic diseases. It is of interest to examine whether risk factors for these diseases are associated with inflammation. We conducted a cross-sectional analysis to evaluate whether reproductive and lifestyle factors and circulating vitamin D were associated with inflammation markers, including C-reactive protein, cytokines (IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p40, IL-12p70, IL-13, TNFα), and cytokine modulators (IL-1RA, sIL-1RII, sIL-2Ra, sIL-4R, sIL-6R, sTNF-R1/R2), among 616 healthy women. We confirmed associations of several inflammation markers with age and BMI. We also observed significantly higher levels of certain inflammation markers in postmenopausal vs. premenopausal women (TNFα, sIL-1RII, sIL-2Ra), with increasing parity (IL-12p40), and with higher circulating 25(OH) vitamin D (IL-13) and lower levels among current users of non-steroidal anti-inflammatory drugs (NSAIDs) (IL-1β, IL-2, IL-10, IL-12p70, and IL-12p40), current smokers (IL-4, IL-13, IL-12p40), and women with a family history of breast or ovarian cancer (IL-4, IL-10, IL-13). Our findings suggest that risk factors for chronic diseases (age, BMI, menopausal status, parity, NSAID use, family history of breast and ovarian cancer, and smoking) are associated with inflammation markers in healthy women.

Emerging therapeutic strategies to enhance HDL function

Epidemiologic studies indicate a strong inverse correlation between plasma levels of high-density lipoproteins (HDL) and cardiovascular disease (CVD). The most relevant cardioprotective mechanism mediated by HDL is thought to be reverse cholesterol transport (RCT). New insights in HDL biology and RCT have allowed the development of promising agents aimed to increase HDL function and promote atherosclerosis regression. In this regard, apo-AI analogs and CETP inhibitors dalcetrapib and anacetrapib have aroused a great interest and opened new expectations in the treatment of CVD.