29 research outputs found
Therapeutic Effect of C-Phycocyanin Extracted from Blue Green Algae in a Rat Model of Acute Lung Injury Induced by Lipopolysaccharide
C-Phycocyanin (CPC), extracted from blue green algae, is a dietary nutritional supplement due to its several beneficial pharmacological effects. This study was conducted to evaluate whether CPC protects against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in rats. Rats were challenged with LPS (5âmg/kg body weight) intratracheally to induce ALI. After 3âh LPS instillation, rats were administrated with CPC (50âmg/kg body weight, i.p.) for another 3âh. Our results showed that posttreatment with CPC significantly inhibited LPS-induced elevation of protein concentration, nitrite/nitrate level, release of proinflammatory cytokines, the number of total polymorphonuclear cells in bronchoalveolar lavage fluid, and lung edema evidenced by decrease of lung wet/dry weight ratio accompanied by a remarkable improvement of lung histopathological alterations. Furthermore, CPC significantly attenuated LPS-induced myeloperoxidase activity, O2â formation, expression of inducible nitric oxide synthase, and cyclooxygenase-2 as well as nuclear factor-kappa B (NF-ÎșB) activation in lungs. Additionally, CPC significantly downregulated proapoptotic proteins such as caspase-3 and Bax, but upregulated antiapoptotic proteins such as Bcl-2 and Bcl-XL in lungs exposed to LPS. These findings indicate that CPC could be potentially useful for treatment of LPS-related ALI by inhibiting inflammatory responses and apoptosis in lung tissues
\u3ci\u3eUncle Tomâs Cabin\u3c/i\u3e in \u3ci\u3eThe National Era\u3c/i\u3e: Commentary on Chapter 1 and 2
In the first chapter of Uncle Tomâs Cabin, Stowe warns her readers that the âindulgenceâ of slave owners and the âaffectionate loyaltyâ of the slaves themselves towards their masters have misled some observers to believe the âpoetic legendâ of slavery as a benevolent âpatriarchal institution.â She does not deny the genuineness of these emotions, but she warns that âthe shadow of a Lawâ makes a mockery of the human relationships that develop between masters and slaves: âSo long as the law considers all these human beings, with beating hearts and living affections, only as so many things belonging to a masterâso long as the failure, or misfortune, or imprudence, or death, of the kindest owner, may cause them any day to exchange a life of kind protection and indulgence for one of hopeless misery and toil, so long it is impossible to make anything beautiful or desirable in the best regulated administration of slavery.â We begin the novel, then, in what seems to be the model benevolent Shelby plantation in Kentucky, not the cruel Legree plantation in Louisiana, where the novel ends. Nevertheless, the âshadow of the law,â in the form of Mr. Shelbyâs obligation to pay his debts, endangers the residents of the Shelby plantation.
Stowe derived her portrait of slavery primarily from reading, not from direct experience and observation in the slave states of the South. She describes Eliza Harris as ânot a fancy sketch, but taken from a remembrance, as we saw her years ago in Kentuckyââthat is, during Stoweâs one brief trip South of the Mason-Dixon line during her years living in Cincinnati. Some white Southerners attacked Stowe for this lack of direct knowledge of the South and slavery. However, as historian William R. Taylor observed fifty years ago, what troubled them the most about Uncle Tomâs Cabin was not that she attacked their point of view, but that she understood it too well. As Taylor explains, beginning in the 1830s white Southerners invented the legend of âplantation paternalism,â âthe image of sunshine and happiness around the plantation home,â to âjustif[y] their peculiar institution to themselves and to others.â[1] Stowe only â[took] the Southerner at his wordâ: she did ânotâŠdeny the Southern defense of slavery butâŠsuggested that it was inadequate, even if its claims were allowed.â Stowe set out to show, Taylor explains, that âkindness, generosity and affection provided no assurance against cruelty and brutalityâ and that âa slave could love his master and mistress and still wish to be free.â[2
Pan-cancer analysis of whole genomes
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe
The Protective Effect of Alpha-Lipoic Acid in Lipopolysaccharide-Induced Acute Lung Injury Is Mediated by Heme Oxygenase-1
Alpha-lipoic acid (ALA), occurring naturally in human food, is known to possess antioxidative and anti-inflammatory activities. Induction of heme oxygenase-1 (HO-1) has been reported to exhibit a therapeutic effect in several inflammatory diseases. The aim of study was to test the hypothesis that the protection of ALA against lipopolysaccharide-(LPS-) induced acute lung injury (ALI) is mediated by HO-1. Pre- or posttreatment with ALA significantly inhibited LPS-induced histological alterations of ALI, lung tissue edema, and production of proinflammatory cytokine, cytokine inducible neutrophil chemoattractant-3, and nitrite/nitrate in bronchoalveolar lavage fluid. In addition, the inflammatory responses including elevation of superoxide formation, myeloperoxidase activity, polymorphonuclear neutrophils infiltration, nitrotyrosine, inducible nitric oxide synthase expression and nuclear factor-kappa B (NF-ÎșB) activation in lung tissues of LPS-instilled rats were also markedly reduced by ALA. Interestingly, treatment with ALA significantly increased nuclear factor-erythroid 2-related factor 2 (Nrf2) activation and HO-1 expression in lungs of ALI. However, blocking HO-1 activity by tin protoporphyrin IX (SnPP), an HO-1 inhibitor, markedly abolished these beneficial effects of ALA in LPS-induced ALI. These results suggest that the protection mechanism of ALA may be through HO-1 induction and in turn suppressing NF-ÎșB-mediated inflammatory responses
Oligo-Fucoidan Improves Diabetes-Induced Renal Fibrosis via Activation of Sirt-1, GLP-1R, and Nrf2/HO-1: An In Vitro and In Vivo Study
Fucoidan extracted from brown algae has multiple beneficial functions. In this study, we investigated the effects of low-molecular-weight fucoidan (oligo-FO) on renal fibrosis under in vitro and in vivo diabetic conditions, and its molecular mechanisms. Advanced glycation product (AGE)-stimulated rat renal proximal tubular epithelial cells (NRK-52E) and diabetic mice induced by high-fat diet and intraperitoneal injection of streptozotocin and nicotinamide were used. Oligo-FO treatment significantly inhibited anti-high mobility group box 1 (HMGB1)/RAGE/ anti-nuclear factor-kappa B (NF-κB)/transforming growth factor-β1 (TGF-β1)/TGF-β1R/Smad 2/3/fibronectin signaling pathway and HIF-1α activation in AGE-stimulated NRK-52E cells. Conversely, the expression and activity of Sirt-1; the levels of ubiquitin-specific peptidase 22 (USP22), p-AMPK, glucagon-like peptide-1 receptor (GLP-1R), and heme oxygenase-1 (HO-1); and Nrf2 activation were remarkably increased by oligo-FO in AGE-stimulated cells. However, the above effects of oligo-FO were greatly diminished by inhibiting Sirt-1, HO-1, or GLP-1R activity. Similar changes of these pro-fibrotic genes in the kidney and a marked attenuation of renal injury and dysfunction were observed in oligo-FO-treated diabetic mice. These findings indicated that the inhibitory effects of the oligo-FO on diabetes-evoked renal fibrosis are mediated by suppressing TGF-β1-activated pro-fibrogenic processes via Sirt-1, HO-1, and GLP-1R dependence. Collectively, fucoidan-containing foods or supplements may be potential agents for ameliorating renal diseases due to excessive fibrosis
Magnolol Ameliorates Ligature-Induced Periodontitis in Rats and Osteoclastogenesis: In Vivo and In Vitro Study
Periodontal disease characterized by alveolar bone resorption and bacterial pathogen-evoked inflammatory response has been believed to have an important impact on human oral health. The aim of this study was to evaluate whether magnolol, a main constituent of Magnolia officinalis, could inhibit the pathological features in ligature-induced periodontitis in rats and osteoclastogenesis. The sterile, 3â0 (diameter; 0.2âmm) black braided silk thread, was placed around the cervix of the upper second molars bilaterally and knotted medially to induce periodontitis. The morphological changes around the ligated molars and alveolar bone were examined by micro-CT. The distances between the amelocemental junction and the alveolar crest of the upper second molars bilaterally were measured to evaluate the alveolar bone loss. Administration of magnolol (100âmg/kg, p.o.) significantly inhibited alveolar bone resorption, the number of osteoclasts on bony surface, and protein expression of receptor activator of nuclear factor-ÎșB ligand (RANKL), a key mediator promoting osteoclast differentiation, in ligated rats. Moreover, the ligature-induced neutrophil infiltration, expression of inducible nitric oxide synthase, cyclooxygenase-2, matrix metalloproteinase (MMP)-1 and MMP-9, superoxide formation, and nuclear factor-ÎșB activation in inflamed gingival tissues were all attenuated by magnolol. In the in vitro study, magnolol also inhibited the growth of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans that are key pathogens initiating periodontal disease. Furthermore, magnolol dose dependently reduced RANKL-induced osteoclast differentiation from RAW264.7 macrophages, tartrate-resistant acid phosphatase (TRAP) activity of differentiated cells accompanied by a significant attenuation of resorption pit area caused by osteoclasts. Collectively, we demonstrated for the first time that magnolol significantly ameliorates the alveolar bone loss in ligature-induced experimental periodontitis by suppressing periodontopathic microorganism accumulation, NF-ÎșB-mediated inflammatory mediator synthesis, RANKL formation, and osteoclastogenesis. These activities support that magnolol is a potential agent to treat periodontal disease
Fucoidan Prevents RANKL-Stimulated Osteoclastogenesis and LPS-Induced Inflammatory Bone Loss via Regulation of Akt/GSK3ÎČ/PTEN/NFATc1 Signaling Pathway and Calcineurin Activity
Excessive osteoclast differentiation and/or function plays a pivotal role in the pathogenesis of bone diseases such as osteoporosis and rheumatoid arthritis. Here, we examined whether fucoidan, a sulfated polysaccharide present in brown algae, attenuates receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclastogenesis in vitro and lipopolysaccharide (LPS)-induced bone resorption in vivo, and investigated the molecular mechanisms involved. Our results indicated that fucoidan significantly inhibited osteoclast differentiation in RANKL-stimulated macrophages and the bone resorbing activity of osteoclasts. The effects of fucoidan may be mediated by regulation of Akt/GSK3β/PTEN signaling and suppression of the increase in intracellular Ca2+ level and calcineurin activity, thereby inhibiting the translocation of nuclear factor-activated T cells c1 (NFATc1) into the nucleus. However, fucoidan-mediated NFATc1 inactivation was greatly reversed by kenpaullone, a GSK3β inhibitor. In addition, using microcomputer tomography (micro-CT) scanning and bone histomorphometry, we found that fucoidan treatment markedly prevented LPS-induced bone erosion in mice. Collectively, we demonstrated that fucoidan was capable of inhibiting osteoclast differentiation and inflammatory bone loss, which may be modulated by regulation of Akt/GSK3β/PTEN/NFATc1 and Ca2+/calcineurin signaling cascades. These findings suggest that fucoidan may be a potential agent for the treatment of osteoclast-related bone diseases
Low Molecular Weight Fucoidan Inhibits Tumor Angiogenesis through Downregulation of HIF-1/VEGF Signaling under Hypoxia
Activation of hypoxia-induced hypoxia-inducible factors-1 (HIF-1) plays a critical role in promoting tumor angiogenesis, growth and metastasis. Low molecular weight fucoidan (LMWF) is prepared from brown algae, and exhibits anticancer activity. However, whether LMWF attenuates hypoxia-induced angiogenesis in bladder cancer cells and the molecular mechanisms involved remain unclear. This is the first study to demonstrate that LMWF can inhibit hypoxia-stimulated H2O2 formation, HIF-1 accumulation and transcriptional activity vascular endothelial growth factor (VEGF) secretion, and the migration and invasion in hypoxic human bladder cancer cells (T24) cells. LMWF also downregulated hypoxia-activated phosphorylation of PI3K/AKT/mTOR/p70S6K/4EBP-1 signaling in T24 cells. Blocking PI3K/AKT or mTOR activity strongly diminished hypoxia-induced HIF-1α expression and VEGF secretion in T24 cells, supporting the involvement of PI3K/AKT/mTOR in the induction of HIF-1α and VEGF. Additionally, LMWF significantly attenuated angiogenesis in vitro and in vivo evidenced by reduction of tube formation of hypoxic human umbilical vascular endothelial cells and blood capillary generation in the tumor. Similarly, administration of LMWF also inhibited the HIF-1α and VEGF expression in vivo, accompanied by a reduction of tumor growth. In summary, under hypoxia conditions, the antiangiogenic activity of LMWF in bladder cancer may be associated with suppressing HIF-1/VEGF-regulated signaling pathway
Mechanisms of Nifedipine-Downregulated CD40L/sCD40L Signaling in Collagen Stimulated Human Platelets
<div><p>The platelet-derived soluble CD40L (sCD40L) release plays a critical role in the development of atherosclerosis. Nifedipine, a dihydropyridine-based L-type calcium channel blocker (CCB), has been reported to have an anti-atherosclerotic effect beyond its blood pressure-lowering effect, but the molecular mechanisms remain unclear. The present study was designed to investigate whether nifedipine affects sCD40L release from collagen-stimulated human platelets and to determine the potential role of peroxisome proliferator-activated receptor-ÎČ/-Îł (PPAR-ÎČ/-Îł). We found that treatment with nifedipine significantly inhibited the platelet surface CD40L expression and sCD40L release in response to collagen, while the inhibition was markedly reversed by blocking PPAR-ÎČ/-Îł activity with specific antagonist such as GSK0660 and GW9662. Meanwhile, nifedipine also enhanced nitric oxide (NO) and cyclic GMP formation in a PPAR-ÎČ/-Îł-dependent manner. When the NO/cyclic GMP pathway was suppressed, nifedipine-mediated inhibition of sCD40L release was abolished significantly. Collagen-induced phosphorylation of p38MAPK, ERK1/2 and HSP27, matrix metalloproteinase-2 (MMP-2) expression/activity and reactive oxygen species (ROS) formation were significantly inhibited by nifedipine, whereas these alterations were all attenuated by co-treatment with PPAR-ÎČ/-Îł antagonists. Collectively, these results demonstrate that PPAR-ÎČ/-Îł-dependent pathways contribute to nifedipine-mediated downregulation of CD40L/sCD40L signaling in activated platelets through regulation of NO/ p38MAPK/ERK1/2/HSP27/MMP-2 signalings and provide a novel mechanism regarding the anti-atherosclerotic effect of nifedipine.</p></div