Probucol treatment is associated with an ABCA1-independent mechanism of cholesterol efflux to lipid poor apolipoproteins from foam cell macrophages

Objective Probucol is a cholesterol-lowering agent whose ability to prevent atherosclerosis is currently under study. Herein, we investigate the putative mechanism of probucol by observation of changes in cellular cholesterol efflux and lipid droplet morphology in macrophages. Results The inhibitory activity of probucol was assessed in non-foam or foam cell macrophages expressing ABCA1 generated by treatment with fetal calf serum (FCS) alone or in combination with acetylated LDL, respectively. Probucol inhibited cholesterol efflux to apolipoprotein A-I (apoA-I) by 31.5±0.1% in THP-1 non-foam cells and by 18.5±0.2% in foam cells. In probucol-treated non-foam THP-1 cells, nascent high-density lipoprotein (nHDL) particles with a diameter < 7 nm were generated, while in probucol-treated THP-1 foam cells nHDL particles of > 7 nm in diameter containing cholesterol were produced. Foam cells also displayed a significant accumulation of free cholesterol at the plasma membrane, as measured by percent cholestenone formed. Intracellularly, there was a significant decrease in lipid droplet number and an increase in size in probucol-treated THP-1 foam cells when compared to non-treated cells. Conclusions We report for the first time that probucol is unable to completely inhibit cholesterol efflux in foam cells to the same extent as in non-foam cells. Indeed, functional nHDL is released from foam cells in the presence of probucol. This difference in inhibitory effect could potentially be explained by changes in the plasma membrane pool as well as intracellular cholesterol storage independently of ABCA1

Phthalates and Bisphenol A: presence in blood serum and follicular fluid of italian women undergoing assisted reproduction techniques

Background: folliculogenesis is a strictly regulated process that may be affected by endocrine disrupting chemicals (EDCs) through sometimes not so clear molecular mechanisms. Methods: we conducted a multicentric observational study involving six fertility centers across Italy, prospectively recruiting 122 women attending a fertility treatment. Recruited women had age ≤42 years, and normal ovarian reserve. Blood and follicular fluid samples were taken for EDCs measurement using liquid chromatography tandem mass spectrometry and each woman completed an epidemiological questionnaire. Results: The main EDCs found were monobutyl phthalate (MBP) (median blood: 8.96 ng/mL, follicular fluid 6.43 ng/mL), monoethylhexyl phthalate (MEHP) (median blood: 9.16 ng/mL, follicular fluid 7.68 ng/mL) and bisphenol A (BPA) (median blood: 1.89 ng/mL, follicular fluid 1.86 ng/mL). We found that serum MBP concentration was significantly associated with the considered area (p < 0.001, adj. mean: 7.61 ng/mL, 14.40 ng/mL, 13.56 ng/mL; Area 1: Milan–Turin, Area 2: Rome–Naples; Area 3: Catania–Bari, respectively) but negatively with home plastic food packaging (p = 0.004). Follicular MBP was associated with irregular cycles (p = 0.019). No association was detected between EDCs and eating habits and other clinical and epidemiological features. Conclusions: This study represents the first Italian biomonitoring of plastic EDCs in follicular fluid, laying the basis for future prospective evaluation on oocyte quality before assisted reproduction techniques (ART

Comparative proximity biotinylation implicates the small GTPase RAB18 in sterol mobilization and biosynthesis

Loss of functional RAB18 causes the autosomal recessive condition Warburg Micro syndrome. To better understand this disease, we used proximity biotinylation to generate an inventory of potential RAB18 effectors. A restricted set of 28 RAB18-interactions were dependent on the binary RAB3GAP1-RAB3GAP2 RAB18-guanine nucleotide exchange factor (GEF) complex. 12 of these 28 interactions are supported by prior reports and we have directly validated novel interactions with SEC22A, TMCO4 and INPP5B. Consistent with a role for RAB18 in regulating membrane contact sites (MCSs), interactors included groups of microtubule/membrane-remodelling proteins, membrane-tethering and docking proteins, and lipid-modifying/transporting proteins. Two of the putative interactors, EBP and OSBPL2/ORP2, have sterol substrates. EBP is a Δ8-Δ7 sterol isomerase and ORP2 is a lipid transport protein. This prompted us to investigate a role for RAB18 in cholesterol biosynthesis. We find that the cholesterol precursor and EBP-product lathosterol accumulates in both RAB18-null HeLa cells and RAB3GAP1-null fibroblasts derived from an affected individual. Further, de novo cholesterol biosynthesis is impaired in cells in which RAB18 is absent or dysregulated, or in which ORP2 expression is disrupted. Our data demonstrate that GEF-dependent Rab-interactions are highly amenable to interrogation by proximity biotinylation and may suggest that Micro syndrome is a cholesterol biosynthesis disorder

MODELS FOR PRESSURE CONTROL OF AUTOMATED DRY CLUTCHES: TEMPERATURE INFLUENCE ON FRICTIONAL AND ELASTIC BEHAVIOUR

Automated Manual Transmissions (AMTs) systems are generally constituted by a dry or wet clutch assembly and a multi-speed gearbox, both equipped with electro-mechanical or electro-hydraulic actuators, which are driven by a control unit, the transmission control unit (TCU). In this transmission type the quality of the vehicle propulsion as perceived by the driver is largely dependent on the quality of the control strategies. This paper aims at investigating the influence of the temperature on the engagement performance of an actively closed dry clutch

Different Effects of Human Umbilical Cord Mesenchymal Stem Cells on Glioblastoma Stem Cells by Direct Cell Interaction or Via Released Soluble Factors

Glioblastoma (GBM), the most common primary brain tumor in adults, is an aggressive, fast-growing and highly vascularized tumor, characterized by extensive invasiveness and local recurrence. In GBM and other malignancies, cancer stem cells (CSCs) are believed to drive invasive tumor growth and recurrence, being responsible for radio- and chemo-therapy resistance. Mesenchymal stem cells (MSCs) are multipotent progenitors that exhibit tropism for tumor microenvironment mediated by cytokines, chemokines and growth factors. Initial studies proposed that MSCs might exert inhibitory effects on tumor development, although, to date, contrasting evidence has been provided. Different studies reported either MSC anti-tumor activity or their support to tumor growth. Here, we examined the effects of umbilical cord (UC)-MSCs on in vitro GBM-derived CSC growth, by direct cell-to-cell interaction or indirect modulation, via the release of soluble factors. We demonstrate that UC-MSCs and CSCs exhibit reciprocal tropism when co-cultured as 3D spheroids and their direct cell interaction reduces the proliferation of both cell types. Contrasting effects were obtained by UC-MSC released factors: CSCs, cultured in the presence of conditioned medium (CM) collected from UC-MSCs, increased proliferation rate through transient ERK1/2 and Akt phosphorylation/activation. Analysis of the profile of the cytokines released by UC-MSCs in the CM revealed a strong production of molecules involved in inflammation, angiogenesis, cell migration and proliferation, such as IL-8, GRO, ENA-78 and IL-6. Since CXC chemokine receptor 2 (CXCR2), a receptor shared by several of these ligands, is expressed in GBM CSCs, we evaluated its involvement in CSC proliferation induced by UC-MSC-CM. Using the CXCR2 antagonist SB225002, we observed a partial but statistically significant inhibition of CSC proliferation and migration induced by the UC-MSC-released cytokines. Conversely, CXCR2 blockade did not reduce the reciprocal tropism between CSCs and UC-MSCs grown as spheroids. In conclusion, we show that direct (cell-to-cell contact) or indirect (via the release of soluble factors) interactions between GBM CSCs and UC-MSCs in co-culture produce divergent effects on cell growth, invasion and migration, with the former mainly causing an inhibitory response and the latter a stimulatory one, involving a paracrine activation of CXCR2

Clinical and laboratory key performance indicators in IVF: A consensus between the Italian Society of Fertility and Sterility and Reproductive Medicine (SIFES-MR) and the Italian Society of Embryology, Reproduction and Research (SIERR)

Purpose: Infertility is increasing worldwide, and many couples seek IVF. Clinical management and laboratory work are fundamental in the IVF journey. Therefore, the definition of reliable key performance indicators (KPIs) based on clinical and laboratory parameters, is essential for internal quality control (IQC). Laboratory performance indicators have been identified and a first attempt to also determine clinical ones has been recently published. However, more detailed indicators are required. Methods: An Italian group of experts in Reproductive Medicine from both public and private clinics on behalf of SIFES-MR and SIERR was established to define IVF indicators to monitor clinical performance. Results: The working group built a consensus on a list of KPIs, performance indicators (PIs) and recommendation indicators (RIs). When deemed necessary, the reference population was stratified by woman age, response to ovarian stimulation and adoption of preimplantation genetic testing for aneuploidies (PGT-A). Each indicator was scored with a value from 1 to 5 and a weighted average formula - considering all the suggested parameters-was defined. This formula generates a center performance score, indicating low, average, good, or excellent performance. Conclusion: This study is intended to provide KPIs, PIs and RIs that encompass several essential aspects of a modern IVF clinic, including quality control and constant monitoring of clinical and embryological features. These indicators could be used to assess the quality of each center with the aim of improving efficacy and efficiency in IVF