scholarly journals Testicular membrane lipid damage by complex mixture of leachate from municipal battery recycling site as indication of idiopathic male infertility in rat

2013 ◽  
Vol 6 (4) ◽  
pp. 192-197 ◽  
Author(s):  
Jacob K. Akintunde ◽  
Ganiyu Oboh ◽  
Akintunde A. Akindahunsi
Keyword(s):  
Male Infertility ◽  
Lipid Membrane ◽  
Complex Mixture ◽  
Membrane Lipid ◽  
Metal Exposure ◽  
Dependent Manner ◽  
Mixed Metal ◽  
Lipid Damage ◽  
Battery Recycling

ABSTRACT Leachate from a municipal battery recycling site is a potent source of mixed-metal released into the environment. The present study investigated the degree at which mixed-metal exposure to the municipal auto-battery leachate (MABL) and to the Elewi Odo municipal auto-battery recycling site leachate (EOMABRL) affected the lipid membrane of the testes in in vitro experiment. The results showed elevated level of mixed-metals over the permissible levels in drinking water, as recommended by regulatory authorities. In the leachate samples, the levels of malondialdehyde (MDA), a biomarker of lipid damage, was significantly (p<0.05) increased in rat testes in a dose-dependent manner. MDA induced by the municipal auto-battery leachate (MABL) was significantly (p<0.05) higher than the leachate from Elewi Odo municipal auto-battery recycling site (EOMABRL). The testicular lipid membrane capacity was compromised following treatment with leachate from the municipal battery recycling site, implicating mixed-metal exposure as the causative agent of testicular damage and male infertility.

scholarly journals Phosphoserine acidic cluster motifs in the cytoplasmic domains of transmembrane proteins bind distinct basic regions on the μ subunits of clathrin adaptor protein complexes

2018 ◽  
Author(s):  
Rajendra Singh ◽  
Charlotte Stoneham ◽  
Christopher Lim ◽  
Xiaofei Jia ◽  
Javier Guenaga ◽  
...  
Keyword(s):  
Protein Trafficking ◽  
Transmembrane Proteins ◽  
Adaptor Protein ◽  
Cellular Protein ◽  
Membrane Lipid ◽  
Dependent Manner ◽  
Cytoplasmic Domains ◽  
Clathrin Adaptor ◽  
Hiv 1

AbstractProtein trafficking in the endosomal system involves the recognition of specific signals within the cytoplasmic domains (CDs) of transmembrane proteins by clathrin adaptors. One such signal is the phosphoserine acidic cluster (PSAC), the prototype of which is in the endoprotease Furin. How PSACs are recognized by clathrin adaptors has been controversial. We reported previously that HIV-1 Vpu, which modulates cellular immunoreceptors, contains a PSAC that binds to the µ subunits of clathrin adaptor protein (AP) complexes. Here, we show that the CD of Furin binds the µ subunits of AP-1 and AP-2 in a phosphorylation-dependent manner. Moreover, we identify a PSAC in a cytoplasmic loop of the cellular transmembrane Serinc3, an inhibitor of the infectivity of retroviruses. The two serines within the PSAC of Serinc3 are phosphorylated by casein kinase II and mediate interaction with the µ subunits in vitro. The sites of these serines vary among mammals in a manner consistent with host-pathogen conflict, yet the Serinc3-PSAC seems dispensible for anti-HIV activity and for counteraction by HIV-1 Nef. The CDs of Vpu, Furin, and the PSAC-containing loop of Serinc3 each bind the μ subunit of AP-2 (µ2) with similar affinities, but they appear to utilize different basic regions on µ2. The Serinc3 loop requires a region previously reported to bind the acidic plasma membrane lipid phosphatidylinositol-4,5-bisphosphate. These data suggest that the PSACs within different proteins recognize different basic regions on the µ surface, providing the potential to inhibit the activity of viral proteins without necessarily affecting cellular protein trafficking.

Antioxidants from stem bark of Kigelia africana inhibits free radicals and membrane lipid damage in rat testes in vitro

2016 ◽  
Vol 5 (2) ◽  
pp. 63 ◽  
Author(s):  
Jacob Akintunde ◽  
Daniel Akintunde ◽  
Emmanuel Irondi ◽  
Kehinde Babaita ◽  
Ramat Labaika ◽  
...  
Keyword(s):  
Free Radicals ◽  
Stem Bark ◽  
Membrane Lipid ◽  
Lipid Damage

scholarly journals The flavonoids, quercetin and isorhamnetin 3-O-acylglucosides diminish neutrophil oxidative metabolism and lipid peroxidation.

2001 ◽  
Vol 48 (1) ◽  
pp. 183-189 ◽  
Author(s):  
M Zielińska ◽  
A Kostrzewa ◽  
E Ignatowicz ◽  
J Budzianowski
Keyword(s):  
Lipid Peroxidation ◽  
Oxidative Metabolism ◽  
Hypochlorous Acid ◽  
Thiobarbituric Acid ◽  
Membrane Lipid ◽  
Polymorphonuclear Neutrophils ◽  
Inhibitory Influence ◽  
Dependent Manner ◽  
In Vitro Production

Two natural flavonoids, quercetin and isorhamnetin 3-O-acylglucosides, were examined for their inhibitory influence on the in vitro production and release of reactive oxygen species in polymorphonuclear neutrophils (PMNs). The generation of superoxide radical, hydrogen peroxide and hypochlorous acid were measured by, respectively, cytochrome c reduction, dichlorofluorescin oxidation and taurine chlorination. Membrane lipid oxidation was studied by the thiobarbituric acid method in mouse spleen microsomes. The addition of flavonoids at the concentration range 1-100 microM inhibited PMNs oxidative metabolism and lipid peroxidation in a dose-dependent manner. The results suggest that these flavonoids suppress the oxidative burst of PMNs and protect membranes against lipid peroxidation.

scholarly journals Association of prohormone convertase 3 with membrane lipid rafts

2001 ◽  
Vol 27 (1) ◽  
pp. 107-116 ◽  
Author(s):  
M Blazquez ◽  
K Docherty ◽  
KI Shennan
Keyword(s):  
Lipid Rafts ◽  
Dominant Role ◽  
Membrane Lipid ◽  
Terminal Region ◽  
Membrane Microdomains ◽  
Membrane Association ◽  
Prohormone Convertase ◽  
Dependent Manner ◽  
Pro Region

Prohormone convertase 3 (PC3) is a neuroendocrine-specific member of the subtilisin-kexin family, involved in the intracellular processing and maturation of prohormones and proneuropeptides. PC3 is synthesised as a proprotein that undergoes two different cleavages resulting in the mature PC3 and the enzymatically active PC3DeltaC. In vitro translated proPC3 and proPC3DeltaC bind to trans-Golgi network (TGN)/granule-enriched membranes from the AtT20 neuroendocrine cell line in a pH-dependent manner suggesting both a dominant role for the pro-region in membrane association and that the C-terminal region is not essential. However, while PC3 bound to membranes the majority of PC3DeltaC did not, suggesting that either the pro-region or the C-terminal region of PC3 is required for membrane association. Removal of peripheral membrane proteins did not affect the binding properties of any of the in vitro translated proteins. Chromaffin granule membranes (CGMs) were used to study the binding characteristics of endogenous PC3 and its active C-terminal truncated counterpart (PC3DeltaC). Incubation of CGMs with Triton X-100 did not completely solubilise either of these forms of PC3. Moreover, both PC3 and PC3DeltaC remained associated with detergent-resistant membrane microdomains, termed lipid rafts, purified from CGMs. The data raise the possibility that PC3 and PC3DeltaC are sorted to the regulated secretory pathway via their association with membrane lipid rafts.

scholarly journals PI(4,5)P2forms dynamic cortical structures and directs actin distribution and cell polarity in C. elegans embryos

2017 ◽  
Author(s):  
Melina J. Scholze ◽  
Kévin S. Barbieux ◽  
Alessandro De Simone ◽  
Mathilde Boumasmoud ◽  
Camille C. N. Süess ◽  
...  
Keyword(s):  
Cell Polarity ◽  
Lipid Membrane ◽  
Asymmetric Division ◽  
Membrane Lipid ◽  
Dependent Manner ◽  
Actin Organization ◽  
C Elegans ◽  
Plasma Membrane Lipid ◽  
Dynamic Structures ◽  
The One

AbstractAsymmetric division is crucial for embryonic development and stem cell lineages. In the one-cellC. elegansembryo, a contractile cortical actomyosin network contributes to anterior-posterior (A-P) polarity and asymmetric division by segregating PAR proteins to discrete cortical domains. Here, we discovered that the plasma membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2) forms dynamic structures inC. eleganszygotes, distributing in a polarized and PAR-dependent manner along the A-P axis. PIP2cortical structures overlap with F-actin and coincide with the actin regulators RHO-1, CDC-42 and ECT-2. Particle image velocimetry analysis revealed that PIP2and F-actin cortical movements are coupled, with PIP2structures moving slightly ahead. Importantly, we established that PIP2cortical structures form in an actin-dependent manner and, conversely, that decreasing or increasing the level of PIP2results in severe F-actin disorganization, revealing the interdependence between these components. Furthermore, we uncovered that PIP2regulates the sizing of PAR cortical domains. Overall, our work establishes for the first time that a lipid membrane component, PIP2, is a critical modulator of actin organization and cell polarity inC. elegansembryos.Summary statementPI(4,5)P2is distributed in dynamic cortical structures and regulates asymmetric division by controlling actin organization and cell polarity in the one-cellC. elegansembryo.

scholarly journals Remodelling of primary human CD4+ T cell plasma membrane order by n-3 PUFA

2017 ◽  
Vol 119 (2) ◽  
pp. 163-175 ◽  
Author(s):  
Yang-Yi Fan ◽  
Natividad R. Fuentes ◽  
Tim Y. Hou ◽  
Rola Barhoumi ◽  
Xian C. Li ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
T Cell ◽  
Cell Membrane ◽  
Membrane Lipid ◽  
Dependent Manner ◽  
Cell Plasma Membrane ◽  
Membrane Order ◽  
Cell Plasma ◽  
T Cell Membrane

AbstractCell membrane fatty acids influence fundamental properties of the plasma membrane, including membrane fluidity, protein functionality, and lipid raft signalling. Evidence suggests that dietary n-3 PUFA may target the plasma membrane of immune cells by altering plasma membrane lipid dynamics, thereby regulating the attenuation of immune cell activation and suppression of inflammation. As lipid-based immunotherapy might be a promising new clinical strategy for the treatment of inflammatory disorders, we conducted in vitro and in vivo experiments to examine the effects of n-3 PUFA on CD4+ T cell membrane order, mitochondrial bioenergetics and lymphoproliferation. n-3 PUFA were incorporated into human primary CD4+ T cells phospholipids in vitro in a dose-dependent manner, resulting in a reduction in whole cell membrane order, oxidative phosphorylation and proliferation. At higher doses, n-3 PUFA induced unique phase separation in T cell-derived giant plasma membrane vesicles. Similarly, in a short-term human pilot study, supplementation of fish oil (4 g n-3 PUFA/d) for 6 weeks in healthy subjects significantly elevated EPA (20 : 5n-3) levels in CD4+ T cell membrane phospholipids, and reduced membrane lipid order. These results demonstrate that the dynamic reshaping of human CD4+ T cell plasma membrane organisation by n-3 PUFA may modulate down-stream clonal expansion.

Chlorobutanol, a Preservative of Desmopressin, Inhibits Human Platelet Aggregation and Release In Vitro

1990 ◽  
Vol 64 (03) ◽  
pp. 473-477 ◽  
Author(s):  
Shih-Luen Chen ◽  
Wu-Chang Yang ◽  
Tung-Po Huang ◽  
Shiang Wann ◽  
Che-ming Teng
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Atp Release ◽  
Free Calcium ◽  
Dependent Manner ◽  
Antiplatelet Effect ◽  
Human Platelet Aggregation ◽  
Acid Pathway ◽  
Arachidonic Acid Pathway

SummaryTherapeutic preparations of desmopressin for parenteral use contain the preservative chlorobutanol (5 mg/ml). We show here that chlorobutanol is a potent inhibitor of platelet aggregation and release. It exhibited a significant inhibitory activity toward several aggregation inducers in a concentration- and time-dependent manner. Thromboxane B2 formation, ATP release, and elevation of cytosolic free calcium caused by collagen, ADP, epinephrine, arachidonic acid and thrombin respectively were markedly inhibited by chlorobutanol. Chlorobutanol had no effect on elastase- treated platelets and its antiplatelet effect could be reversed. It is concluded that the antiplatelet effect of chlorobutanol is mainly due to its inhibition on the arachidonic acid pathway but it is unlikely to have a nonspecitic toxic effect. This antiplatelet effect of chlorobutanol suggests that desmopressin, when administered for improving hemostasis, should not contain chlorobutanol as a preservative.

Inhibition of Platelet Aggregation by Ethanol in Vitro Shows Specificity for Aggregating Agent Used and Is Influenced by Platelet Lipid Composition

1982 ◽  
Vol 48 (01) ◽  
pp. 049-053 ◽  
Author(s):  
C G Fenn ◽  
J M Littleton
Keyword(s):  
Platelet Aggregation ◽  
Lipid Composition ◽  
Saturated Fatty Acids ◽  
Calcium Ionophore ◽  
Cholesterol Content ◽  
Membrane Lipid ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Increased Sensitivity

SummaryEthanol at physiologically tolerable concentrations inhibited platelet aggregation in vitro in a relatively specific way, which may be influenced by platelet membrane lipid composition. Aggregation to collagen, calcium ionophore A23187 and thrombin (low doses) were often markedly inhibited by ethanol, adrenaline and ADP responses were little affected, and aggregation to exogenous arachidonic acid was actually potentiated by ethanol. Aggregation to collagen, thrombin and A23187 was inhibited more by ethanol in platelets enriched with saturated fatty acids than in those enriched with unsaturated fats. Platelets enriched with cholesterol showed increased sensitivity to ADP, arachidonate and adrenaline but this increase in cholesterol content did not appear to influence the inhibition by ethanol of platelet responses. The results suggest that ethanol may inhibit aggregation by an effect on membrane fluidity and/or calcium mobilization resulting in decreased activity of a membrane-bound phospholipase.

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki
Keyword(s):  
Carbon Monoxide ◽  
Hydroxysteroid Dehydrogenase ◽  
Dependent Manner ◽  
In Vitro Production ◽  
Mitochondrial Preparation ◽  
Final Reaction ◽  
Vitro Production ◽  
Dose Dependent ◽  
Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

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