Maternal serum lipid levels, oxidative stress and antioxidant activity in pre-eclampsia patients from Southwest India

Atrial Natriuretic Peptide Inhibited ABCA1/G1-dependent Cholesterol Efflux Related to Low HDL-C in Hypertensive Pregnant Patients

Objective: It has been reported that atrial natriuretic peptide (ANP) regulates lipid metabolism by stimulating adipocyte browning, lipolysis, and lipid oxidation, and by impacting the secretion of adipokines. In our previous study, we found that the plasma ANP concentration of hypertensive disorders of pregnancy (HDP) was significantly increased in comparison to that of normotensive pregnancy patients. Thus, this study’s objective was to investigate the lipid profile in patients with HDP and determine the effects of ANP on the cholesterol efflux in THP-1 macrophages.

Methods: A total of 265 HDP patients and 178 normotensive women as the control group were recruited. Clinical demographic characteristics and laboratory profile data were collected. Plasma total triglycerides (TGs), total cholesterol (TC), low-density cholesterol (LDL-C), and high-density cholesterol (HDL-C) were compared between the two groups. THP-1 monocytes were incubated with different concentrations of ANP. ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) mRNA and protein were evaluated. ABCA1- and ABCG1-mediated cholesterol efflux to apolipoprotein A-Ⅰ (apoA-Ⅰ) and HDL, respectively, were measured by green fluorescent labeled NBD cholesterol. Natriuretic peptide receptor A (NPR-A) siRNA and specific agonists of the peroxisome proliferator–activated receptor-γ (PPAR-γ) and liver X receptor α (LXRα) were studied to investigate the mechanism involved.

Results: Plasma TG, TC, LDL-C, and LDL-C/HDL-C were significantly increased, and HDL-C was significantly decreased in the HDP group in comparison to the control (all p < 0.001). ANP inhibited the expression of ABCA1 and ABCG1 at both the mRNA and protein levels in a dose-dependent manner. The functions of ABCA1- and ABCG1-mediated cholesterol efflux to apoA-I and HDL were significantly decreased. NPR-A siRNA further confirmed that ANP binding to its receptor inhibited ABCA1/G1 expression through the PPAR-γ/LXRα pathway.

Conclusions: ABCA1/G1 was inhibited by the stimulation of ANP when combined with NPR-A through the PPAR-γ/LXRα pathway in THP-1 macrophages. The ABCA1/G1-mediated cholesterol efflux was also impaired by the stimulation of ANP. This may provide a new explanation for the decreased level of HDL-C in HDP patients.

Seminal protein levels assessed with dipstick test correlate with sperm recovery after cryopreservation

The process of freezing/thawing causes structural and functional damage to sperm samples, which can be mitigated by seminal plasma proteins. This study investigated the proposition that seminal protein measurements using a urinary dipstick prior to freezing could help predict the post-thaw recovery of live spermatozoa. This was a prospective study including 149 men undergoing semen analysis due to male and/or female infertility. The seminal samples were analysed according to World Health Organisation standards and protein concentrations were measured using a commercially available urinary dipstick following quantitative validation. The median live sperm recovery rates were 79%, 81% and 94%, respectively, in samples with protein concentrations of ≤1.0 g/L (+/++), 3.0 g/L (+++) and ≥20.0 g/L (++++) measured in fresh specimen dipstick analysis (p < 0.05) indicating that the probability of recovering at least 50% of frozen spermatozoa increased progressively with higher protein concentrations in the fresh sample (chi-square for linear association = 7.17. p = 0.007). In conclusion, fresh seminal protein concentration levels assessed with a dipstick test correlate with the proportion of live spermatozoa recovered from cryopreserved samples. This simple, low-cost test may add prognostic information to baseline semen analysis prior to sperm banking.

Oxidative stress in pregnancy complicated by preeclampsia

Preeclampsia is a multisystemic disorder of pregnancy that causes perinatal morbidity and mortality. Studies published in the last decade have contributed to a better understanding of physiopathogenesis through key mechanisms involved, such as altered immune response, endothelial dysfunction, oxidative stress and systemic inflammatory response, as well as genetic susceptibility. Oxidative stress (OS) plays an important role in the development of preeclampsia, since it alters placental remodeling and placental vascular endothelial dysfunction, resulting in an ischemia/reperfusion injury with an increase in xanthine oxidase activity that produces high levels of reactive oxygen species (ROS). ROS can be generated through many pathways within cells, mitochondria, endoplasmic reticulum (ER) and enzymes such as NADPH oxidase are the most important sources, causing widespread and indiscriminate damage to cells and tissues, which leads to an intravascular inflammatory response and maternal systemic endothelial dysfunction characteristic of this prenatal syndrome. Therefore, the following review aims to identify the main risk factors and the role of OS as a pathophysiological mechanism in the development of preeclampsia.