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141.
142.
Macrophage foam cell is the predominant cell type in atherosclerotic lesions. Removal of excess cholesterol from macrophages thus offers effective protection against atherosclerosis. Here we report that a protein kinase A (PKA)-anchoring inhibitor, st-Ht31, induces robust cholesterol/phospholipid efflux, and ATP-binding cassette transporter A1 (ABCA1) greatly facilitates this process. Remarkably, we found that st-Ht31 completely reverses foam cell formation, and this process is ABCA1-dependent. The reversal is also accompanied by the restoration of well modulated inflammatory response to LPS. There is no detectable toxicity associated with st-Ht31, even when cells export up to 20% cellular cholesterol per hour. Using FRET-based PKA biosensors in live cells, we provide evidence that st-Ht31 drives cholesterol efflux by elevating PKA activity specifically in the cytoplasm. Furthermore, ABCA1 facilitates st-Ht31 uptake. This allows st-Ht31 to effectively remove cholesterol from ABCA1-expressing cells. We speculate that de-anchoring of PKA offers a novel therapeutic strategy to remove excess cholesterol from lipid-laden lesion macrophages. 相似文献
143.
Hein I Klinger S Dooms M Flekna G Stessl B Leclercq A Hill C Allerberger F Wagner M 《Applied and environmental microbiology》2011,77(6):2169-2173
Listeria monocytogenes strains (n = 117) were screened for the presence of stress survival islet 1 (SSI-1). SSI-1(+) strains (32.5%) belonged mainly to serotypes 1/2c, 3b, and 3c. All sequence type 121 (ST-121) strains included (n = 7) possessed homologues to Listeria innocua genes lin0464 and lin0465 instead of SSI-1. 相似文献
144.
The aim of the present study was to test for the efficacy of a slow release GnRH-agonist implant (4.7 mg deslorelin, Suprelorin®) in the male cat. Ten toms were implanted sc in the neck. Changes in testosterone (T) secretion, testicular size, body weight and behaviour (mounting, mating, urine marking) were monitored. T concentrations were significantly decreased (P < 0.0001) to basal levels (< 0.1 ng/mL) in 5 of 10 cats after 4 weeks and in all but one tom after 11 weeks (T < 0.1 ng/mL). In this respective tom only partial downregulation with T-values from 0.2 to 0.1 ng/mL was achieved until week 27. In weeks 28 and 32, T concentrations were below 0.1 ng/mL. Compared to pretreatment values, testicular volume was significantly decreased by about 60% in week 12 and about 73% after 36 weeks (P < 0.001). Penile spines disappeared 9.4 ± 1.0 weeks after treatment. Food intake was significantly increased during treatment period (P < 0.001). In all tomcats libido, mating behaviour and urine marking were significantly reduced (P < 0.0001) after an initial stimulation. In one tom, mating an oestrous queen on day 20 after implant administration resulted in pregnancy. Mating of another tom that had T-values between 0.1 and < 0.1 ng/mL since day 24 in week 8 revealed the presence of spermatozoa; however, this mating did not result in pregnancy.Subcutaneous implant administration was well tolerated by all tomcats without sedation or anaesthesia and no treatment related negative effects were observed.These results demonstrate the clinical efficacy of the 4.7 mg deslorelin implants (Suprelorin®) in the tom inducing all castration related effects. 相似文献
145.
Guillouet M Gueret G Rannou F Giroux-Metges MA Gioux M Arvieux CC Pennec JP 《American journal of physiology. Cell physiology》2011,301(5):C1057-C1063
146.
Rannou F Pennec JP Morel J Guéret G Leschiera R Droguet M Gioux M Giroux-Metges MA 《Journal of applied physiology (Bethesda, Md. : 1985)》2011,111(2):495-507
Muscle immobilization leads to modification in its fast/slow contractile phenotype. Since the properties of voltage-gated sodium channels (Na(v)) are different between "fast" and "slow" muscles, we studied the effects of immobilization on the contractile properties and the Na(v) of rat peroneus longus (PL). The distal tendon of PL was cut and fixed to the adjacent bone at neutral muscle length. After 4 or 8 wk of immobilization, the contractile and the Na(v) properties were studied and compared with muscles from control animals (Student's t-test). After 4 wk of immobilization, PL showed a faster phenotype with a rightward shift of the force-frequency curve and a decrease in both the Burke's index of fatigability and the tetanus-to-twitch ratio. These parameters showed opposite changes between 4 and 8 wk of immobilization. The maximal sodium current in 4-wk immobilized fibers was higher compared with that of control fibers (11.5 ± 1.2 vs. 7.8 ± 0.8 nA, P = 0.008), with partial recovery to the control values in 8-wk immobilized fibers (8.6 ± 0.7 nA, P = 0.48). In the presence of tetrodotoxin, the maximal residual sodium current decreased continuously throughout immobilization. Using the Western blot analysis, Na(v)1.4 expression showed a transient increase in 4-wk muscle, whereas Na(v)1.5 expression decreased during immobilization. Our results indicate that a muscle immobilized at optimal functional length with the preservation of neural inputs exhibits a transient fast phenotype conversion. Na(v)1.4 expression and current are related to the contractile phenotype variation. 相似文献
147.
Mathurin K Gallant MA Germain P Allard-Chamard H Brisson J Iorio-Morin C de Brum Fernandes A Caron MG Laporte SA Parent JL 《The Journal of biological chemistry》2011,286(4):2696-2706
L-type prostaglandin synthase (L-PGDS) produces PGD(2), a lipid mediator involved in neuromodulation and inflammation. Here, we show that L-PGDS and arrestin-3 (Arr3) interact directly and can be co-immunoprecipitated endogenously from MG-63 osteoblasts. Perinuclear L-PGDS/Arr3 co-localization is observed in PGD(2)-producing MG-63 cells and is induced by the addition of the L-PGDS substrate or co-expression of COX-2 in HEK293 cells. Inhibition of L-PGDS activity in MG-63 cells triggers redistribution of Arr3 and L-PGDS to the cytoplasm. Perinuclear localization of L-PGDS is detected in wild-type mouse embryonic fibroblasts (MEFs) but is more diffused in MEFs-arr-2(-/-)-arr-3(-/-). Arrestin-3 promotes PGD(2) production by L-PGDS in vitro. IL-1β-induced PGD(2) production is significantly lower in MEFs-arr-2(-/-)-arr-3(-/-) than in wild-type MEFs but can be rescued by expressing Arr2 or Arr3. A peptide corresponding to amino acids 86-100 of arrestin-3 derived from its L-PGDS binding domain stimulates L-PGDS-mediated PGD(2) production in vitro and in MG-63 cells. We report the first characterization of an interactor/modulator of a PGD(2) synthase and the identification of a new function for arrestin, which may open new opportunities for improving therapies for the treatment of inflammatory diseases. 相似文献
148.
During the Circumpolar Flaw Lead System Study (CFL, 2007–2008), large aggregations of polar cod were detected in winter in
the Amundsen Gulf (Western Canadian Arctic) using the EK60 echosounder of the CCGS Amundsen research icebreaker. Biomass estimated over 10 months reached a maximum of 0.732 kg m−2 in February. Aggregations were encountered only in the presence of an ice cover from December to April. The vertical extent
of the aggregations was dictated by temperature and zooplankton prey distribution. In winter, polar cod generally occupied
the relatively warm deep Atlantic Layer (>0°C), but a fraction of the densest aggregations occasionally followed zooplankton
prey up into the cold Pacific Halocline (−1.6 to 0°C). The diel vertical migration of polar cod was precisely synchronized
with the seasonally increasing photoperiod. Throughout winter, polar cod aggregations migrated to progressively deeper regions
(from 220 to 550 m bottom depths) in response to increasing light intensity, presumably to avoid predation by visual predators
such as the ringed seal. Comparing Amundsen Gulf and Franklin Bay indicates that the entrapment of polar cod in embayments
during winter is an important mechanism to provide marine mammal predators with dense concentrations of their main prey within
their diving range. 相似文献
149.
Maxime T. A. Alexandre Kathi Gundermann Andrew A. Pascal Rienk van Grondelle Claudia Büchel Bruno Robert 《Photosynthesis research》2014,119(3):273-281
In this study, we demonstrate the selective in vivo detection of diadinoxanthin (DD) and diatoxanthin (DT) in intact Cyclotella cells using resonance Raman spectroscopy. In these cells, we were able to assess both the content of DD and DT carotenoids relative to chlorophyll and their conformation. In addition, the sensitivity and selectivity of the technique allow us to discriminate between different pools of DD on a structural basis, and to follow their fate as a function of the illumination conditions. We report that the additional DD observed when cells are grown in high-light conditions adopts a more twisted conformation than the lower levels of DD present when the cells are grown in low-light (LL) conditions. Thus, we conclude that this pool of DD is more tightly bound to a protein-binding site, which must differ from the one occupied by the DD present in LL conditions. 相似文献
150.
Maxime Guéguinou Aurélie Chantôme Gaëlle Fromont Philippe Bougnoux Christophe Vandier Marie Potier-Cartereau 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2014
Potassium channels belong to the largest and the most diverse super-families of ion channels. Among them, Ca2 +-activated K+ channels (KCa) comprise many members. Based on their single channel conductance they are divided into three subfamilies: big conductance (BKCa), intermediate conductance (IKCa) and small conductance (SKCa; SK1, SK2 and SK3). Ca2 + channels are divided into two main families, voltage gated/voltage dependent Ca2 + channels and non-voltage gated/voltage independent Ca2 + channels. Based on their electrophysiological and pharmacological properties and on the tissue where there are expressed, voltage gated Ca2 + channels (Cav) are divided into 5 families: T-type, L-type, N-type, P/Q-type and R-type Ca2 +. Non-voltage gated Ca2 + channels comprise the TRP (TRPC, TRPV, TRPM, TRPA, TRPP, TRPML and TRPN) and Orai (Orai1 to Orai3) families and their partners STIM (STIM1 to STIM2). A depolarization is needed to activate voltage-gated Ca2 + channels while non-voltage gated Ca2 + channels are activated by Ca2 + depletion of the endoplasmic reticulum stores (SOCs) or by receptors (ROCs). These two Ca2 + channel families also control constitutive Ca2 + entries. For reducing the energy consumption and for the fine regulation of Ca2 +, KCa and Ca2 + channels appear associated as complexes in excitable and non-excitable cells. Interestingly, there is now evidence that KCa–Ca2 + channel complexes are also found in cancer cells and contribute to cancer-associated functions such as cell proliferation, cell migration and the capacity to develop metastases. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau. 相似文献