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141.
Aydin S Dag E Ozkan Y Arslan O Koc G Bek S Kirbas S Kasikci T Abasli D Gokcil Z Odabasi Z Catak Z 《Peptides》2011,32(6):1276-1280
A relationship between hormones and seizures has been reported in animals and humans. Therefore, the purpose of this study was to investigate the association between serum levels of prolactin, nesfatin-1 and ghrelin measured different times after a seizure or non-epileptic event and compared with controls. The study included a total of 70 subjects, and of whom 18 patients had secondary generalized epilepsy (SGE), 16 patients had primary generalized epilepsy (PGE), 16 patients exhibited paroxysmal event (psychogenic) and 20 healthy males were control subjects. The first sample was taken within 5 min of a seizure, with further samples taken after 1, 24, and 48 h so long as the patient did not exhibit further clinically observable seizures; blood samples were taken once from control subjects. Prolactin was measured immediately using TOSOH Bioscience hormone assays. Nesfatin-1 and ghrelin peptides were measured using a commercial immunoassay kit. Patients suffering from focal epilepsy with secondary generalization and primary generalized epilepsy presented with significantly higher levels of serum prolactin and nesfatin-1 and lower ghrelin levels 5 min, 1 and 24 h after a seizure than patients presenting with paroxysmal events (psychogenic) and control subjects; the data were similar but not statistically significant after 48 h. The present study suggests that increased serum prolactin and nesfatin-1 concentrations, decreased ghrelin concentrations could be used as markers to identify patients that have suffered a recent epileptic seizure or other paroxysmal event (psychogenic). 相似文献
142.
The ameliorative role of 28-homobrassinolide under chilling stress in various growth, photosynthesis, enzymes and biochemical
parameters of cucumber (Cucumis sativus L.) were investigated. Cucumber seedlings were sprayed with 0 (control), 10−8, or 10−6 M of 28-homobrassinolide at the 30-day stage. 48 h after treatment plants were exposed for 18 h to chilling temperature (10/8°C,
5/3°C). The most evident effect of chilling stress was the marked reduction in plant growth, chlorophyll (Chl) content, and
net photosynthetic rate, efficiency of photosystem II and activities of nitrate reductase and carbonic anhydrase. Moreover,
the activities of antioxidant enzymes; catalase (E.C. 1.11.1.6), peroxidase (E.C.1.11.1.7), superoxide dismutase (E.C. 1.15.1.1)
along with the proline content in leaves of the cucumber seedlings increased in proportion to chilling temperature. The stressed
seedlings of cucumber pretreated with 28-homobrassinolide maintained a higher value of antioxidant enzymes and proline content
over the control suggesting the protective mechanism against the ill-effect caused by chilling stress might be operative through
an improved antioxidant system. Furthermore, the protective role of 28-homobrassinolide was reflected in improved growth,
water relations, photosynthesis and maximum quantum yield of photosystem II both in the presence and absence of chilling stress. 相似文献
143.
Khavandgar Z Poirier C Clarke CJ Li J Wang N McKee MD Hannun YA Murshed M 《The Journal of cell biology》2011,194(2):277-289
A deletion mutation called fro (fragilitas ossium) in the murine Smpd3 (sphingomyelin phosphodiesterase 3) gene leads to a severe skeletal dysplasia. Smpd3 encodes a neutral sphingomyelinase (nSMase2), which cleaves sphingomyelin to generate bioactive lipid metabolites. We examined endochondral ossification in embryonic day 15.5 fro/fro mouse embryos and observed impaired apoptosis of hypertrophic chondrocytes and severely undermineralized cortical bones in the developing skeleton. In a recent study, it was suggested that nSMase2 activity in the brain regulates skeletal development through endocrine factors. However, we detected Smpd3 expression in both embryonic and postnatal skeletal tissues in wild-type mice. To investigate whether nSMase2 plays a cell-autonomous role in these tissues, we examined the in vitro mineralization properties of fro/fro osteoblast cultures. fro/fro cultures mineralized less than the control osteoblast cultures. We next generated fro/fro;Col1a1-Smpd3 mice, in which osteoblast-specific expression of Smpd3 corrected the bone abnormalities observed in fro/fro embryos without affecting the cartilage phenotype. Our data suggest tissue-specific roles for nSMase2 in skeletal tissues. 相似文献
144.
Hou Q Jin J Zhou H Novgorodov SA Bielawska A Szulc ZM Hannun YA Obeid LM Hsu YT 《Journal of lipid research》2011,52(2):278-288
C(6)-pyridinium (D-erythro-2-N-[6'-(1'-pyridinium)-hexanoyl]sphingosine bromide [LCL29]) is a cationic mitochondrion-targeting ceramide analog that promotes mitochondrial permeabilization and cancer cell death. In this study, we compared the biological effects of that compound with those of D-erythro-C(6)-ceramide, its non-mitochondrion-targeting analog. In MCF7 cells it was found that C(6)-pyridinium ceramide preferentially promoted autophagosome formation and retarded cell growth more extensively than its uncharged analog. This preferential inhibition of cell growth was also observed in breast epithelial cells and other breast cancer cells. In addition, this compound could promote Bax translocation to mitochondria. This redistribution of Bax in MCF7 cells could be blocked by the pan-caspase inhibitor zVAD-fmk but via a Bid-independent signaling pathway. Moreover, C(6)-pyridinium ceramide-induced translocation of Bax to mitochondria led to mitochondrial permeabilization and cell death. Overall, we show that mitochondrial targeting of C(6)-pyridinium ceramide significantly enhances cellular response to this compound. 相似文献
145.
Jenkins RW Idkowiak-Baldys J Simbari F Canals D Roddy P Riner CD Clarke CJ Hannun YA 《The Journal of biological chemistry》2011,286(5):3777-3788
Acid sphingomyelinase (aSMase) catalyzes the hydrolysis of sphingomyelin (SM) to form the bioactive lipid ceramide (Cer). Notably, aSMase exists in two forms: a zinc (Zn(2+))-independent lysosomal aSMase (L-SMase) and a Zn(2+)-dependent secreted aSMase (S-SMase) that arise from alternative trafficking of a single protein precursor. Despite extensive investigation into the maturation and trafficking of aSMase, the exact identity of mature L-SMase has remained unclear. Here, we describe a novel mechanism of aSMase maturation involving C-terminal proteolytic processing within, or in close proximity to, endolysosomes. Using two different C-terminal-tagged constructs of aSMase (V5, DsRed), we demonstrate that aSMase is processed from a 75-kDa, Zn(2+)-activated proenzyme to a mature 65 kDa, Zn(2+)-independent L-SMase. L-SMase is recognized by a polyclonal Ab to aSMase, but not by anti-V5 or anti-DsRed antibodies, suggesting that the C-terminal tag is lost during maturation. Furthermore, indirect immunofluorescence staining demonstrated that mature L-SMase colocalized with the lysosomal marker LAMP1, whereas V5-aSMase localized to the Golgi secretory pathway. Moreover, V5-aSMase possessed Zn(2+)-dependent activity suggesting it may represent the common protein precursor of S-SMase and L-SMase. Importantly, the 65-kDa L-SMase, but not V5-aSMase, was sensitive to the lysosomotropic inhibitor desipramine, co-fractionated with lysosomes, and migrated at the same M(r) as partially purified human aSMase. Finally, three aSMase mutants containing C-terminal Niemann-Pick mutations (R600H, R600P, ΔR608) exhibited defective proteolytic maturation. Taken together, these results demonstrate that mature L-SMase arises from C-terminal proteolytic processing of pro-aSMase and suggest that impaired C-terminal proteolysis may lead to severe defects in L-SMase function. 相似文献
146.
Wu BX Clarke CJ Matmati N Montefusco D Bartke N Hannun YA 《The Journal of biological chemistry》2011,286(25):22362-22371
Sphingolipids such as ceramide are recognized as vital regulators of many biological processes. Neutral sphingomyelinase 2 (nSMase2) is one of the key enzymes regulating ceramide production. It was previously shown that the enzymatic activity of nSMase2 was dependent on anionic phospholipids (APLs). In this study, the structural requirements for APL-selective binding of nSMase2 were determined and characterized. Using lipid-protein overlay assays, nSMase2 interacted specifically and directly with several APLs, including phosphatidylserine and phosphatidic acid. Lipid-protein binding studies of deletion mutants identified two discrete APL binding domains in the N terminus of nSMase2. Further, mutagenesis experiments pinpointed the core sequences and major cationic amino acids in the domains that are necessary for the cooperative activation of nSMase2 by APLs. The first domain included the first amino-terminal hydrophobic segment and Arg-33, which were essential for nSMase2 to interact with APLs. The second binding domain was comprised of the second hydrophobic segment and Arg-92 and Arg-93. Moreover, mutation of one or both domains decreased APL binding and APL-dependent catalytic activity of nSMase2. Further, mutation of both domains in nSMase2 reduced its plasma membrane localization. Finally, these binding domains are also important for the capability of nSMase2 to rescue the defects of yeast lacking the nSMase homologue, ISC1. In conclusion, these data have identified the APL binding domains of nSMase2 for the first time. The analysis of interactions between nSMase2 and APLs will contribute to our understanding of signaling pathways mediated by sphingolipid metabolites. 相似文献
147.
Belarbi el H Contreras Gómez A Chisti Y García Camacho F Molina Grima E 《Biotechnology advances》2003,21(7):585-598
Marine sponges are potential sources of many unique metabolites, including cytotoxic and anticancer compounds. Natural sponge populations are insufficient or inaccessible for producing commercial quantities of metabolites of interest. This review focuses on methods of producing sponge biomass to overcome supply limitations. Production techniques discussed include aquaculture in the sea, the controlled environments of aquariums, and culture of sponge cells and primmorphs. Cultivation in the sea and aquariums are currently the only practicable and relatively inexpensive methods of producing significant quantities of sponge biomass. In the future, metabolite production from cultured sponge cells and primmorphs may become feasible. Obtaining a consistent biomass yield in aquariums requires attention to many factors that are discussed in this work. 相似文献
148.
149.
Hydrogen peroxide (H2O2) in minute quantity serves as a signalling molecule. However, the role of H2O2 in combination with brassinosteroids (stress regulators) in plants under toxic levels of copper, is poorly understood. With an aim to explore and elaborate their role in plants subjected to abiotic stress, the surface sterilized seeds of mung bean (Vigna radiata) were sown in earthen pots filled with soil and manure enriched with different levels of Cu2+ (50 or 100 mg kg?1 of soil) and allowed to grow under natural environmental conditions. At 15 and 20 days stage, the plants were sprayed with H2O2 (2.5 mM) and/or 28-homobrassinolide (HBL, 10?5 mM), respectively. At 45 days stage, the analysis of the plants revealed that the presence of copper in the soil caused a significant decrease in growth characteristics, activity of carbonic anhydrase and nitrate reductase, relative water content, chlorophyll content and the rate of photosynthesis whereas, the activity of antioxidant enzymes (catalase, peroxidase and superoxide dismutase) and the proline accumulation in leaves increased in Cu stressed plants. However, the exogenously applied HBL and/or H2O2, in the absence of Cu-stress strongly favoured the growth, photosynthetic parameters and also improved the activity of antioxidant enzymes and the proline content. Furthermore, the combined application of HBL and H2O2 to the foliage of the stressed plants neutralized the toxic impact of all copper regimes. Therefore, we are of the opinion that these chemicals somehow maintained the homeostasis of the metal in the plants that exhibit healthy growth. 相似文献
150.
Richard Whitlock Jeff S. Healey Stuart J. Connolly Julie Wang Matthew R. Danter Jack V. Tu Richard Novick Stephen Fremes Kevin Teoh Vikas Khera Salim Yusuf 《CMAJ》2014,186(12):905-911