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31.
Uric Acid Amplifies Aβ Amyloid Effects Involved in the Cognitive Dysfunction/Dementia: Evidences From an Experimental Model In Vitro 下载免费PDF全文
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33.
Enhancing macroautophagy protects against ischemia/reperfusion injury in cardiac myocytes 总被引:8,自引:0,他引:8
Cardiac myocytes undergo programmed cell death as a result of ischemia/reperfusion (I/R). One feature of I/R injury is the increased presence of autophagosomes. However, to date it is not known whether macroautophagy functions as a protective pathway, contributes to programmed cell death, or is an irrelevant event during cardiac I/R injury. We employed simulated I/R of cardiac HL-1 cells as an in vitro model of I/R injury to the heart. To assess macroautophagy, we quantified autophagosome generation and degradation (autophagic flux), as determined by steady-state levels of autophagosomes in relation to lysosomal inhibitor-mediated accumulation of autophagosomes. We found that I/R impaired both formation and downstream lysosomal degradation of autophagosomes. Overexpression of Beclin1 enhanced autophagic flux following I/R and significantly reduced activation of pro-apoptotic Bax, whereas RNA interference knockdown of Beclin1 increased Bax activation. Bcl-2 and Bcl-x(L) were protective against I/R injury, and expression of a Beclin1 Bcl-2/-x(L) binding domain mutant resulted in decreased autophagic flux and did not protect against I/R injury. Overexpression of Atg5, a component of the autophagosomal machinery downstream of Beclin1, did not affect cellular injury, whereas expression of a dominant negative mutant of Atg5 increased cellular injury. These results demonstrate that autophagic flux is impaired at the level of both induction and degradation and that enhancing autophagy constitutes a powerful and previously uncharacterized protective mechanism against I/R injury to the heart cell. 相似文献
34.
Dihydroflavonol 4-reductase (DFR, EC 1.1.1.219) catalyzes the reduction of dihydroflavonols to leucoanthocyanins, a key "late" step in the biosynthesis of anthocyanins. In this study we showed that a strong reduction in DFR expression occurs in the non-red orange cultivar (Navel and Ovale) compared to that of the red orange (Tarocco) suggesting that the enzyme could be involved in the lack of production of anthocyanins. Therefore, we isolated and compared the cDNAs, the genomic clones, as well as the promoter regions of blood and blond orange dfrs. Our data revealed that the cDNA sequences of pigmented and non-pigmented orange DFRs were 100% homologous and contained a 1017 bp open reading frame which encodes a protein of 338 amino acid residues, corresponding to a molecular mass of 38010.76 Da, with a theoretical pI of 5.96. Moreover, we found that there were no significant differences in non-coding regions (introns and 5' upstream region) of dfr sequences. Southern blot analysis of genomic DNA indicated that dfr was present as a single copy gene in both cultivars. From these findings the low expression level of blond orange dfr, which might play a role in the phenotypic change from blood to blond orange, is thought to be the result of a likely mutation in a regulatory gene controlling the expression of dfr. In addition, here we reported the successful expression of orange DFR cDNAs leading to an active DFR enzyme which converts dihydroquercetin to leucoanthocyanidin, thus confirming the involvement of the isolated genes in the biosynthesis of anthocyanins. Moreover, as far as we know, this is the first report concerning the in vitro expression of DFR from fruit flesh whose biochemical properties might be very different from those of other plant organ DFRs. 相似文献
35.
Penolazzi L Lambertini E Tavanti E Torreggiani E Vesce F Gambari R Piva R 《Cell biology international》2008,32(2):320-325
We have used cytokine protein array to analyze the secretion of cytokines from an osteoblastic clone derived from human umbilical cord blood mesenchymal stem cells (MSCs) cultured in an osteogenic differentiation medium. The analysis demonstrated the unexpected ability of osteoblast committed cells and their early progenitors to produce significant amounts of a range of soluble immune mediators without in vitro exposure to clinically relevant bacterial pathogens. The cells were expanded and their osteogenic potential analyzed over 45 days of culture was revealed by the expression of osteoblast-specific markers (alkaline phosphatase and Runx2), and by matrix mineralization. Over this culture period, the cells secreted particularly high levels of IL-8, MCP-1 and VEGF, but did not express IL-2, IL-7, IL-17, eotaxin, G-CSF and IFN-gamma. These findings should encourage the use of human umbilical cord blood as a potential stem cells source for bone regeneration. 相似文献
36.
Eduardo A. Nillni Theodore C. Friedman Roberta B. Todd †Nigel P. Birch Y. Peng Loh Ivor M. D. Jackson 《Journal of neurochemistry》1995,65(6):2462-2472
Abstract: Pro-thyrotropin-releasing hormone (proTRH) is the precursor to thyrotropin-releasing hormone (TRH; pGlu-His-Pro-NH2), the hypothalamic releasing factor that stimulates synthesis and release of thyrotropin from the pituitary gland. Five copies of the TRH progenitor sequence (Gln-His-Pro-Gly) and seven cryptic peptides are formed following posttranslational proteolytic cleavage of the 26-kDa rat proTRH precursor. The endopeptidase(s) responsible for the physiological conversion of proTRH to the TRH progenitor form is currently unknown. We examined the in vitro processing of [3H]leucine-labeled or unlabeled proTRH by partially purified recombinant PC1. Recombinant PC1 processed the 26-kDa TRH precursor by initially cleaving the prohormone after the basic amino acid at either position 153 or 159. Based on the use of our well-established antibodies, we propose that the initial cleavage gave rise to the formation of a 15-kDa N-terminal peptide (preproTRH25–152 or preproTRH25–158) and a 10-kDa C-terminal peptide (preproTRH154–255 or preproTRH160–255). Some initial cleavage occurred after amino acid 108 to generate a 16.5-kDa C-terminal peptide. The 15-kDa N-terminal intermediate was further processed to a 6-kDa peptide (preproTRH25–76 or preproTRH25–82) and a 3.8-kDa peptide (preproTRH83–108), whereas the 10-kDa C-terminal intermediate was processed to a 5.4-kDa peptide (preproTRH206–255). The optimal pH for these cleavages was 5.5. ZnCl2, EDTA, EGTA, and the omission of Ca2+ inhibited the formation of pYE27 (preproTRH25–50), one of the proTRH N-terminal products, by 48, 82, 72, and 45%, respectively. This study provides evidence, for the first time, that recombinant PC 1 enzyme can process proTRH to its predicted peptide intermediates. 相似文献
37.
Annalisa Cossu Anna Maria Posadino Roberta Giordo Costanza Emanueli Anna Maria Sanguinetti Amalia Piscopo Marco Poiana Giampiero Capobianco Antonio Piga Gianfranco Pintus 《PloS one》2012,7(11)
The cardiovascular benefits associated with diets rich in fruit and vegetables are thought to be due to phytochemicals contained in fresh plant material. However, whether processed plant foods provide the same benefits as unprocessed ones is an open question. Melanoidins from heat-processed apricots were isolated and their presence confirmed by colorimetric analysis and browning index. Oxidative injury of endothelial cells (ECs) is the key step for the onset and progression of cardiovascular diseases (CVD), therefore the potential protective effect of apricot melanoidins on hydrogen peroxide-induced oxidative mitochondrial damage and cell death was explored in human ECs. The redox state of cytoplasmic and mitochondrial compartments was detected by using the redox-sensitive, fluorescent protein (roGFP), while the mitochondrial membrane potential (MMP) was assessed with the fluorescent dye, JC-1. ECs exposure to hydrogen peroxide, dose-dependently induced mitochondrial and cytoplasmic oxidation. Additionally detected hydrogen peroxide-induced phenomena were MMP dissipation and ECs death. Pretreatment of ECs with apricot melanoidins, significantly counteracted and ultimately abolished hydrogen peroxide-induced intracellular oxidation, mitochondrial depolarization and cell death. In this regard, our current results clearly indicate that melanoidins derived from heat-processed apricots, protect human ECs against oxidative stress. 相似文献
38.
Ogaki Mayara B. Coelho Lívia C. Vieira Rosemary Neto Arthur A. Zani Carlos L. Alves Tânia M. A. Junior Policarpo A. S. Murta Silvane M. F. Barbosa Emerson C. Oliveira Jaquelline G. Ceravolo Isabela P. Pereira Patrícia O. Cota Betania B. Viana Roberta O. Alves Viviane S. Rosa Luiz H. 《Extremophiles : life under extreme conditions》2020,24(2):227-238
Extremophiles - We accessed the culturable mycobiota present in marine sediments at different depths in Antarctica Ocean. Acremonium fusidioides, Penicillium allii-sativi, Penicillium chrysogenum,... 相似文献
39.
Jian-Jun Jia Roni M Lahr Michael T Solgaard Bruno J Moraes Roberta Pointet An-Dao Yang Giovanna Celucci Tyson E Graber Huy-Dung Hoang Marius
R Niklaus Izabella A Pena Anne K Hollensen Ewan M Smith Malik Chaker-Margot Leonie Anton Christopher Dajadian Mark Livingstone Jaclyn Hearnden Xu-Dong Wang Yonghao Yu Timm Maier Christian K Damgaard Andrea J Berman Tommy Alain Bruno D Fonseca 《Nucleic acids research》2021,49(6):3461
40.
Roberta Bonfiglioli Patrizia Mussoni Francesca Graziosi Monica Calabrese Andrea Farioli Francesco Marinelli Francesco S. Violante 《Journal of electromyography and kinesiology》2013,23(1):252-259
To test whether the influence of manual activity should be considered when interpreting the results of nerve conduction study (NCS) of the upper limbs performed during work shifts, we evaluated the short-term effect of 90-min repetitive manual work on NCS parameters. Twenty-eight healthy volunteers underwent NCS of the dominant limb at the end of an interview (T0), after a 30-min rest in sitting position (T1) and after performing a standardized 90-min manual task (T2). The task was designed to simulate typical assembly and packing activities. No significant differences were observed for skin temperature (Ts) and NCS parameters between T0 and T1. Significantly (p < 0.001) higher Ts mean values were found at T2 as compared to the previous tests for both females and males. The regression analysis showed an association between temperature variation and nerve conduction velocity values for the median and ulnar nerve at T2 as compared to T1. In females, a reduction of the mean sensory nerve action potential (SNAP) amplitude at T2 was recorded, whereas an opposite trend was observed among males. Manual work is able to influence hand Ts and to modify NCS parameters. SNAP amplitudes changes suggest gender differences in peripheral nerve characteristics that deserve further investigation. 相似文献