Association of resistin with impaired membrane fluidity of red blood cells in hypertensive and normotensive men: an electron paramagnetic resonance study

Assessment of Red Blood Cell Aggregation in Preeclampsia by Microfluidic Image Flow Analysis-Impact of Oxidative Stress on Disease Severity

Preeclampsia (PE) is a hypertensive disease characterized by proteinuria, endothelial dysfunction, and placental hypoxia. Reduced placental blood flow causes changes in red blood cell (RBC) rheological characteristics. Herein, we used microfluidics techniques and new image flow analysis to evaluate RBC aggregation in preeclamptic and normotensive pregnant women. The results demonstrate that RBC aggregation depends on the disease severity and was higher in patients with preterm birth and low birth weight. The RBC aggregation indices (EAI) at low shear rates were higher for non-severe (0.107 ± 0.01) and severe PE (0.149 ± 0.05) versus controls (0.085 ± 0.01; p < 0.05). The significantly more undispersed RBC aggregates were found at high shear rates for non-severe (18.1 ± 5.5) and severe PE (25.7 ± 5.8) versus controls (14.4 ± 4.1; p < 0.05). The model experiment with in-vitro-induced oxidative stress in RBCs demonstrated that the elevated aggregation in PE RBCs can be partially due to the effect of oxidation. The results revealed that RBCs from PE patients become significantly more adhesive, forming large, branched aggregates at a low shear rate. Significantly more undispersed RBC aggregates at high shear rates indicate the formation of stable RBC clusters, drastically more pronounced in patients with severe PE. Our findings demonstrate that altered RBC aggregation contributes to preeclampsia severity.

The effects of adsorbed benzo(a)pyrene on dynamic behavior of polystyrene nanoplastics through phospholipid membrane: A molecular simulation study

Nanoplastics (NPs) are mainly generated from the decomposition of plastic waste and industrial production, which have attracted much attention due to the potential risk for humans. The ability of NPs to penetrate different biological barriers has been proved, but the understanding of molecular details is very limited, especially for organic pollutant-NP combinations. Here, we investigated the uptake process of polystyrene NPs (PSNPs) combined with benzo(a)pyrene (BAP) molecules by dipalmitoylphosphatidylcholine (DPPC) bilayers by molecular dynamics (MD) simulations. The results showed that the PSNPs can adsorb and accumulate BAP molecules in water phase and then carried BAP molecules to enter DPPC bilayers. At the same time, the adsorbed BAP promoted the penetration of PSNPs into DPPC bilayers effectively by hydrophobic effect. The process of BAP-PSNP combinations penetrating into DPPC bilayers can be summarized into four steps including adhesion on the DPPC bilayer surface, uptake by the DPPC bilayer, BAP molecules detached from the PSNPs, and the PSNPs depolymerized in the bilayer interior. Furthermore, the amount of adsorbed BAP on PSNPs affected the properties of DPPC bilayers directly, especially the fluidity of DPPC bilayers that determine the physiologic function. Obviously, the combined effect of PSNPs and BAP enhanced the cytotoxicity. This work not only presented a vivid transmembrane process of BAP-PSNP combinations and revealed the nature of the effects of adsorbed benzo(a)pyrene on the dynamic behavior of polystyrene nanoplastics through phospholipid membrane, but also provide some necessary information of the potential damage for organic pollutant-nanoplastic combinations on human health at a molecular level.

Association between dietary fat quality indices with anthropometric measurements in children and adolescents

Background

The association between anthropometric measures and dietary fat quality indices is unclear in pediatric age groups. The present study aimed to assess the association between dietary lipophilic index (LI) and thrombogenic index (TI) as dietary fat quality indices with anthropometric measurements in children and adolescents.

Method

This nationwide cross-sectional study was conducted on 4323 students aged 6-18 years that were selected by multistage cluster sampling from 31 provinces of Iran. Dietary intake was collected using a validated food frequency questionnaire and dietary LI and TI were calculated by formula. Data on anthropometric measures were collected by standard protocols.

Results

The multivariate regression analysis revealed that TI and LI had inverse association with neck circumference Z-score (β = 0.11, p = 0.013 and β = 0.12 p = 0.006, respectively). There was a positive correlation between LI with height Z-score (β = 0.12, 95% CI: 0.01, p = 0.009). However, there was no significant association between LI and TI with other anthropometric indices (P > 0.05).

Conclusion

The quality of dietary fats was associated with some anthropometric indices. Further large-scale studies are required to highlight the importance of dietary fat quality indices in relation to cardio-metabolic risk factors in pediatric age groups. Reducing intake of saturated fatty acids, increasing consumption of monounsaturated fatty acids and a balanced intake of omega-3 and omega-6 to reduce the risk of cardiovascular diseases risk factors are recommended.

Molecular dynamics exploring of atmosphere components interacting with lung surfactant phospholipid bilayers

Sulfur dioxide (SO₂), nitrogen oxide (NO₂) and ozone (O₃) in the atmosphere are significantly correlated with various respiratory and cardiovascular diseases. High doses of each of these gases or a mixture can change the physical and chemical properties of the lung membrane, thus leading to an increased pulmonary vascular permeability and structural failure of the alveolar cell membrane. In the present study, detailed molecular dynamic (MD) modeling was applied to investigate the effects of SO₂, NO₂, O₃ and mixtures of these gases on the dipalmitoyl phosphatidylcholine (DPPC) phospholipid bilayer. The results showed that several key physical properties, including the mass density, lipid ordering parameter, lipid diffusion, and electrostatic potential of the cell membrane, have been changed by the binding of different compounds. This resulted in significant variations and more disorder in the DPPC bilayer. The multiple analyses of membrane properties proved the toxicity of NO₂, O₃, and SO₂ to the DPPC bilayer, providing a theoretical basis for the experimental phenomenon that SO₂, NO₂ and O₃ can cause lung cell apoptosis. For the single systems, the damage to DPPC bilayer caused by O₃ was more serious than NO₂ and SO₂. More importantly, the MD simulations using the mixtures of SO₂, NO₂, and O₃ showed a much greater decline of membrane fluidity and the aggravation of membrane damage than the single systems, indicating a synergistic effect when NO₂, SO₂, and O₃ coexisted in the atmosphere, which could lead to much more severe damage and greater toxicities to the lung.

Higher Lipophilic Index Indicates Higher Risk of Coronary Heart Disease in Postmenopausal Women

Fatty acids (FAs) are essential components of cell membranes and play an integral role in membrane fluidity. The lipophilic index [LI, defined as the sum of the products between FA levels and melting points (°C), divided by the total amount of FA: [Formula: see text]] is thought to reflect membrane and lipoprotein fluidity and may be associated with the risk of coronary heart disease (CHD). Therefore, we examined the associations of dietary and plasma phospholipid (PL) LI with CHD risk among postmenopausal women. We determined dietary LI for the cohort with completed baseline food frequency questionnaires and free of prevalent cardiovascular diseases in the Women's Health Initiative (WHI) observational study (N = 85,563). We additionally determined plasma PL LI in a matched case-control study (N = 2428) nested within the WHI observational cohort study. Cox proportional hazard regression and multivariable conditional logistic regression were used to calculate HRs/ORs for CHD risk between quartiles of LI after adjusting for potential sources of confounding and selection bias. Higher dietary LI in the cohort study and plasma PL LI in the case-control study were significantly associated with increased risk of CHD: HR = 1.18 (95% CI 1.07-1.31, P for trend <0.01) and OR = 1.76 (95% CI 1.33-2.33, P for trend <0.01) comparing extreme quartiles and adjusting for potential confounders. These associations still persisted after adjusting for the polyunsaturated to saturated fat ratio. Our study indicated that higher LI based on either dietary or plasma measurements, representing higher FA lipophilicity, was associated with elevated risk of CHD among postmenopausal women.