Blocking NHE Channels Reduces the Ability of In Vitro Capacitated Mammalian Sperm to Respond to Progesterone Stimulus

Few data exist about the presence and physiological role of Na+/H+ exchangers (NHEs) in the plasma membrane of mammalian sperm. In addition, the involvement of these channels in the ability of sperm to undergo capacitation and acrosomal reaction has not been investigated in any mammalian species. In the present study, we addressed whether these channels are implicated in these two sperm events using the pig as a model. We also confirmed the presence of NHE1 channels in the plasma membrane of ejaculated sperm by immunofluorescence and immunoblotting. The function of NHE channels during in vitro capacitation was analyzed by incubating sperm samples in capacitating medium for 300 min in the absence or presence of a specific blocker (DMA; 5-(N,N-dimethyl)-amiloride) at different concentrations (1, 5, and 10 µM); acrosome exocytosis was triggered by adding progesterone after 240 min of incubation. Sperm motility and kinematics, integrity of plasma and acrosome membranes, membrane lipid disorder, intracellular calcium and reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP) were evaluated after 0, 60, 120, 180, 240, 250, 270, and 300 min of incubation. NHE1 localized in the connecting and terminal pieces of the flagellum and in the equatorial region of the sperm head and was found to have a molecular weight of 75 kDa. During the first 240 min of incubation, i.e., before the addition of progesterone, blocked and control samples did not differ significantly in any of the parameters analyzed. However, from 250 min of incubation, samples treated with DMA showed significant alterations in total motility and the amplitude of lateral head displacement (ALH), acrosomal integrity, membrane lipid disorder, and MMP. In conclusion, while NHE channels are not involved in the sperm ability to undergo capacitation, they could be essential for triggering acrosome exocytosis and hypermotility after progesterone stimulus.

Current Aspect of Bisphenol A Toxicology and Its Health Effects

Bisphenol A (BPA) is a synthetic and dangerous chemical that is released extensively into the environment. BPA is utilized to synthesize polycarbonate plastics for an assortment of basic items such as electronic gadgets, housewares and apparatuses, water pipes, food packaging and containers. Because of the widespread use of BPA products, people are easily exposed to BPA from using these products in their daily life, especially BPA-contaminated food. BPA intake is found in Oceania, Asia, Europe, and North America in both children and adults. Ingestion is a significant route of BPA exposure. The mechanisms of BPA toxicity involve oxidative stress production, genetic and epigenetic dysregulation, nuclear receptor dysfunction, insulin resistance, and adipose tissue inflammation. Exposure to BPA has many health effects, which include altered neurogenesis and reproductive toxicity. Recently, BPA has also been associated with non-communicable diseases, including cardiovascular disease, cancer, lipid disorder, and diabetes. Toxicological data could provide insights that might be useful for promoting awareness to BPA toxicity and preventing BPA-associated diseases. Herein, this review aims to summarize the current knowledge on the toxicological profiles and health effects of BPA, with emphasis on the mechanisms of its toxicity. HIGHLIGHTS Human exposure to BPA is a major public health concern owing to toxicity Contaminated seafood and food containers are important sources of BPA exposure BPA toxicity involves the endocrine, neuronal, cardiovascular, and reproductive systems Mechanisms of BPA toxicity has been linked to nuclear receptor, genetic and epigenetic, oxidative stress, and brain receptors Pregnant women and children are especially vulnerable to BPA exposure GRAPHICAL ABSTRACT

Parkinson Disease Protein 7 (PARK7) Is Related to the Ability of Mammalian Sperm to Undergo In Vitro Capacitation

Parkinson disease protein 7 (PARK7) is a multifunctional protein known to be involved in the regulation of sperm motility, mitochondrial function, and oxidative stress response in mammalian sperm. While ROS generation is needed to activate the downstream signaling pathways required for sperm to undergo capacitation, oxidative stress has detrimental effects for sperm cells and a precise balance between ROS levels and antioxidant activity is needed. Considering the putative antioxidant role of PARK7, the present work sought to determine whether this protein is related to the sperm ability to withstand in vitro capacitation. To this end, and using the pig as a model, semen samples were incubated in capacitation medium for 300 min; the acrosomal exocytosis was triggered by the addition of progesterone after 240 min of incubation. At each relevant time point (0, 120, 240, 250, and 300 min), sperm motility, acrosome and plasma membrane integrity, membrane lipid disorder, mitochondrial membrane potential, intracellular calcium and ROS were evaluated. In addition, localization and protein levels of PARK7 were also assessed through immunofluorescence and immunoblotting. Based on the relative content of PARK7, two groups of samples were set. As early as 120 min of incubation, sperm samples with larger PARK7 content showed higher percentages of viable and acrosome-intact sperm, lipid disorder and superoxide levels, and lower intracellular calcium levels when compared to sperm samples with lower PARK7. These data suggest that PARK7 could play a role in preventing sperm from undergoing premature capacitation, maintaining sperm viability and providing a better ability to keep ROS homeostasis, which is needed to elicit sperm capacitation. Further studies are required to elucidate the antioxidant properties of PARK7 during in vitro capacitation and acrosomal exocytosis of mammalian sperm, and the relationship between PARK7 and sperm motility.

Health Profile of Precarious Migrants Attending the Médecins Du Monde’s Health and Social Care Centres in France: a Cross-Sectional Study

Objective: The present study aimed to compare the precarious migrants’ health problems managed in Médecins du Monde’s health and social care centres (CASO) with those of patients attending general practice in France.Methods: We compared the most frequent health problems managed in the 19 CASO in metropolitan France with those of a national sample of usual general practice consultations, after standardisation for age and sex.Results: Precarious migrants had fewer health problems managed per consultation than other patients (mean: 1.31 vs. 2.16), and these corresponded less frequently to chronic conditions (21.3% vs. 46.8%). The overrepresented health problems among CASO consultations were mainly headache (1.11% vs. 0.45%), viral hepatitis (1.05% vs. 0.20%), type 1 diabetes (1.01% vs. 0.50%) and teeth/gum disease (1.01% vs. 0.23%). Their underrepresented health problems were mainly lipid disorder (0.39% vs. 8.20%), depressive disorder (1.36% vs. 5.28%) and hypothyroidism (0.50% vs. 3.08%). Prevention issues were nominal in precarious migrants (0.16%).Conclusion: Both chronic somatic and mental conditions of precarious migrants are presumably underdiagnosed. Their screening should be improved in primary care.

The G2A Receptor Deficiency Aggravates Atherosclerosis in Rats by Regulating Macrophages and Lipid Metabolism

The orphan G protein-coupled receptor G2A has been linked to atherosclerosis development. However, available data from mouse models are controversial. Rat G2A receptor bears more similarities with its human homolog. We proposed that the atherosclerosis model established from Ldlr–/– rat, which has been reported to share more similar phenotypes with the human disease, may help to further understand this lipid receptor. G2A deletion was found markedly aggravated in the lipid disorder in the rat model, which has not been reported in mouse studies. Examination of aortas revealed exacerbated atherosclerotic plaques in G2A deficient rats, together with increased oxidative stress and macrophage accumulation. In addition, consistently promoted migration and apoptosis were noticed in G2A deficient macrophages, even in macrophages from G2A single knockout rats. Further analysis found significantly declined phosphorylation of PI3 kinase (PI3K) and AKT, together with reduced downstream genes Bcl2 and Bcl-xl, suggesting possible involvement of PI3K/AKT pathway in G2A regulation to macrophage apoptosis. These data indicate that G2A modulates atherosclerosis by regulating lipid metabolism and macrophage migration and apoptosis. Our study provides a new understanding of the role of G2A in atherosclerosis, supporting it as a potential therapeutic target.

CircRNAs have the potential to aid in the diagnosis and treatment of lipid diseases

CircRNAs have the potential to aid in the diagnosis and treatment of lipid diseases, and further study and development is needed in the future. Further advancements, for example, are required in disease-oriented critical circRNA screening technology, which can analyze differentially expressed circRNAs in different tissues and screen out the key circRNAs, providing valuable biomarkers for diagnosis or targets to treat lipid disorder diseases. We need to figure out how to modulate circRNA expression upstream, such as biogenesis and decay, or how to directly upregulate or downregulate certain circRNA expression, setting the framework for clinical intervention in certain critical circRNA in the etiology of certain lipid disorders illness. Understanding the principles governing circRNAsponging mciroRNAs is critical because it will aid in the development of new nucleic acid treatments for lipid diseases.Engineered circRNA with bulged miRNA binding sites effectively sponged the miRNA132/212 family and attenuated myocardial hypertrophy with a low dosage requirement, extended half-lives, high efficiency, and stability when compared to the antagomir, suggesting that it has exciting potential as a novel therapeutic tool. These studies will pave the way for circRNAs to be employed as diagnostic biomarkers or therapeutic targets for lipid diseases in the clinic.

Exercise improves lipid metabolism disorders induced by high-fat diet in a SESN2/JNK- independent manner

SESN2 and JNK are emerging powerful stress-inducible proteins in regulating lipid metabolism. The aim of this study was to determine the underlying mechanism of SESN2/JNK signaling in exercise improving lipid disorder induced by high-fat diet (HFD). Our data showed that HFD and SESN2 knockout resulted in abnormalities including elevated body weight, increased fat mass, serum total cholesterol (TC), lipid biosynthesis related proteins, and a concomitant increase of pJNK-Thr183/Tyr185. The above changes were reversed by exercise training. SESN2 silencing or JNK inhibition in palmitate-treated C2C12 further confirmed that SESN2 and JNK play a vital role in lipid biosynthesis. Rescue experiment further demonstrated that SESN2 reduced lipid biosynthesis through inhibition of JNK. SESN2/JNK signaling axis regulates lipid biosynthesis in both animal and cell models with abnormalities of lipid metabolism induced by HFD or palmitate treatment. This study provided evidence that exercise ameliorated lipid metabolic disorder induced by HFD feeding or by SESN2 knockout. SESN2 may improve lipid metabolism through inhibition JNK expression in skeletal muscle cells, providing a molecular mechanism that may represent an attractive target for the treatment of lipid disorder. Novelty: ● Exercise improved lipid disorder induced by HFD feeding and SESN2 knockout. ● SESN2 and JNK play a vital role in lipid biosynthesis in vivo and in vitro. ● SESN2 suppressed JNK to improve lipid metabolism in skeletal muscle cells.

Sitosterolemia: Twenty Years of Discovery of the Function of ABCG5ABCG8

Sitosterolemia is a lipid disorder characterized by the accumulation of dietary xenosterols in plasma and tissues caused by mutations in either ABCG5 or ABCG8. ABCG5 ABCG8 encodes a pair of ABC half transporters that form a heterodimer (G5G8), which then traffics to the surface of hepatocytes and enterocytes and promotes the secretion of cholesterol and xenosterols into the bile and the intestinal lumen. We review the literature from the initial description of the disease, the discovery of its genetic basis, current therapy, and what has been learned from animal, cellular, and molecular investigations of the transporter in the twenty years since its discovery. The genomic era has revealed that there are far more carriers of loss of function mutations and likely pathogenic variants of ABCG5 ABCG8 than previously thought. The impact of these variants on G5G8 structure and activity are largely unknown. We propose a classification system for ABCG5 ABCG8 mutants based on previously published systems for diseases caused by defects in ABC transporters. This system establishes a framework for the comprehensive analysis of disease-associated variants and their impact on G5G8 structure–function.

HVCN1 but Not Potassium Channels Are Related to Mammalian Sperm Cryotolerance

Little data exist about the physiological role of ion channels during the freeze–thaw process in mammalian sperm. Herein, we determined the relevance of potassium channels, including SLO1, and of voltage-gated proton channels (HVCN1) during mammalian sperm cryopreservation, using the pig as a model and through the addition of specific blockers (TEA: tetraethyl ammonium chloride, PAX: paxilline or 2-GBI: 2-guanidino benzimidazole) to the cryoprotective media at either 15 °C or 5 °C. Sperm quality of the control and blocked samples was performed at 30- and 240-min post-thaw, by assessing sperm motility and kinematics, plasma and acrosome membrane integrity, membrane lipid disorder, intracellular calcium levels, mitochondrial membrane potential, and intracellular O2−⁻ and H2O2 levels. General blockade of K+ channels by TEA and specific blockade of SLO1 channels by PAX did not result in alterations in sperm quality after thawing as compared to control samples. In contrast, HVCN1-blocking with 2-GBI led to a significant decrease in post-thaw sperm quality as compared to the control, despite intracellular O2−⁻ and H2O2 levels in 2-GBI blocked samples being lower than in the control and in TEA- and PAX-blocked samples. We can thus conclude that HVCN1 channels are related to mammalian sperm cryotolerance and have an essential role during cryopreservation. In contrast, potassium channels do not seem to play such an instrumental role.

Barriers, facilitators, and solutions to familial hypercholesterolemia treatment

Background Familial hypercholesterolemia (FH) is an inherited lipid disorder that confers high risk for premature cardiovascular disease but remains undertreated. Causes are multifactorial and multilevel, ranging from underprescribing (at the clinician-level) to medication nonadherence (at the patient-level). We evaluated patient and clinician stakeholder barriers and facilitators for treatment of FH to explore possible solutions to the problem. Methods and results Semi-structured interviews and focus groups guided by the Practical, Robust, Implementation and Sustainability Model (PRISM), were conducted with 33 patients and 17 clinician stakeholders across three healthcare systems. A total of14 patients and 9 clinician stakeholders participated in on-site focus groups and the remainder were individual interviews. Transcripts were coded using an iterative process to create a static codebook. We characterized patient and clinician stakeholder barriers into three categories: medical care-, medication-, and life-related. Feasibility of brainstormed solutions varied and was not always representative of the needs of all stakeholders. Patients suggested a need for childhood screening for FH and doctors being persistent about the importance of treating FH, creation of a patient peer group, data transparency, advocacy, and policy changes that would enable patients to receive better treatment. Clinician stakeholders suggested the need for clinical champions. Both groups of stakeholders discussed the need for education about FH. Conclusions Proposed solutions to improve treatment of FH proffered by participants in this study included resources for both patients and clinician stakeholders that clarify cardiovascular disease risks from FH, develop programs to screen for and identify FH at younger ages, and foster open conversations between patients and clinicians about treatment.