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91.
Chen X Kokkotou EG Mustafa N Bhaskar KR Sougioultzis S O'Brien M Pothoulakis C Kelly CP 《The Journal of biological chemistry》2006,281(34):24449-24454
Saccharomyces boulardii (Sb), a probiotic yeast, protects against intestinal injury and inflammation caused by a wide variety of enteric pathogens, including Clostridium difficile. Given the broad range of protective effects of Sb in multiple gastrointestinal disorders, we hypothesize that Sb modulates host signaling pathways involved in intestinal inflammatory responses. In this study, we found that Sb culture supernatant (SbS) inhibits interleukin-8 production induced by C. difficile toxin A or IL-1beta in human colonocyte NCM460 cells in a dose-dependent fashion. Furthermore, SbS inhibited IL-1beta and toxin A induced Erk1/2 and JNK/SAPK but not p38 activation in NCM460 cells. To test whether this inhibition also occurs in vivo, we used a previously established mouse ileal loop model. On its own, SbS had no significant effect on basal fluid secretion or intestinal histology. However, Erk1/2 activation was significantly inhibited by SbS in toxin A exposed mouse ileal mucosa. In control loops, toxin A increased fluid secretion (2.2-fold), histological score (3.3-fold), and levels of the chemokine KC (4.5-fold). SbS pretreatment completely normalized toxin A mediated fluid secretion (p < 0.01), and histopathologic changes (p < 0.01) and substantially inhibited toxin A-associated KC increases (p < 0.001). In summary, the probiotic yeast S. boulardii inhibits C. difficile toxin A-associated enteritis by blocking the activation of Erk1/2 MAP kinases. This study indicates a new mechanism whereby Sb protects against intestinal inflammation and supports the hypothesis that Sb modulates host inflammatory signaling pathways to exert its beneficial effects. 相似文献
92.
Jennifer E. Adair Vandy Stober Mack Sobhany Lisheng Zhuo John D. Roberts Masahiko Negishi Koji Kimata Stavros Garantziotis 《The Journal of biological chemistry》2009,284(25):16922-16930
Pulmonary epithelial injury is central to the pathogenesis of many lung diseases, such as asthma, pulmonary fibrosis, and the acute respiratory distress syndrome. Regulated epithelial repair is crucial for lung homeostasis and prevents scar formation and inflammation that accompany dysregulated healing. The extracellular matrix (ECM) plays an important role in epithelial repair after injury. Vitronectin is a major ECM component that promotes epithelial repair. However, the factors that modify cell-vitronectin interactions after injury and help promote epithelial repair are not well studied. Inter-α-trypsin inhibitor (IaI) is an abundant serum protein. IaI heavy chains contain von Willebrand A domains that can bind the arginine-glycine-aspartate domain of vitronectin. We therefore hypothesized that IaI can bind vitronectin and promote vitronectin-induced epithelial repair after injury. We show that IaI binds vitronectin at the arginine-glycine-aspartate site, thereby promoting epithelial adhesion and migration in vitro. Furthermore, we show that IaI-deficient mice have a dysregulated response to epithelial injury in vivo, consisting of decreased proliferation and epithelial metaplasia. We conclude that IaI interacts not only with hyaluronan, as previously reported, but also other ECM components like vitronectin and is an important regulator of cellular repair after injury.Epithelial injury is a crucial component in the pathogenesis of many lung diseases. Bronchial epithelial injury occurs chronically in asthmatic patients (1, 2). Furthermore, alveolar and bronchiolar epithelial injury are early triggers in idiopathic pulmonary fibrosis (3) and in lung transplant rejection (4), respectively. In acute respiratory distress syndrome, diffuse alveolar epithelial injury initiates the inflammatory and fibrotic response that leads to lung dysfunction (5). It is now believed that a dysregulated response to epithelial injury ultimately causes fibroproliferation, scar formation, and respiratory failure in acute as well as chronic lung injury (3). It is therefore important to understand the epithelial repair process after pulmonary epithelial injury, if we are to develop causal treatments for these diseases.The mechanisms governing epithelial repair are incompletely understood. Epithelial repair encompasses cell proliferation, migration, and differentiation. All of these processes require cell interactions with the extracellular matrix (ECM).2 ECM components like tenascin C, fibronectin, and vitronectin promote epithelial regeneration through integrin binding. Vitronectin (Vn) is a pluripotent 75-kDa plasma and ECM glycoprotein that regulates a number of biological processes such as coagulation, complement activation, and wound healing. Vn promotes cell adhesion and migration via binding primarily to integrins αvβ1, αvβ3, αvβ5, and αvβ6. After cell binding, Vn can protect bronchial epithelial cells from apoptosis (6) by inducing Akt phosphorylation and preventing caspase and Fas-associated with death domain (FADD) activation (7). Vn also binds to non-integrin cell receptors such as urokinase-type plasminogen activator receptor to promote changes in cell morphology, migration, and signal transduction (8). Consequently, Vn deficiency impairs bronchial (6) and alveolar (9) epithelial repair.Cell-Vn interactions are modulated by other extracellular factors. For example, plasminogen activator inhibitor 1 (PAI-1) is bound to circulating Vn and forms multimers with Vn upon extravasation to the extracellular space (10), thus possibly activating Vn into an adhesive form (11). Furthermore, Vn possesses several domains that can function as possible ligands, such as a somatomedin B domain, an arginine-glycine-aspartate (RGD) domain, and a heparin-binding domain. However, the extent to which other serum or ECM factors may interact with Vn and influence cell-Vn interactions is unclear.In this report, we investigated possible interactions between Vn and the serum and ECM protein inter-α-trypsin inhibitor. Inter-α-trypsin inhibitor (IaI) is a complex protein found in relatively high concentrations in mammalian plasma. It is made up of a light chain (called bikunin for its two Kunitz domains), which confers the protease inhibitory activity, as well as two heavy chains (12). The precise functions of the heavy chains are unknown. Heavy chains contain a von Willebrand Type A (vWA) domain, and they have been shown to bind to hyaluronan and thereby stabilize the extracellular matrix. However, vWA domains are fairly promiscuous and can bind to a large array of proteins, including RGD domains. Furthermore, IaI is expressed by epithelial cells under stress conditions and is incorporated into de novo ECM structures produced by stressed epithelia (13). We therefore hypothesized that IaI may interact with Vn and thus promote epithelial survival after injury. 相似文献
93.
Giovanna Zimatore Alessandro Giuliani Stavros Hatzopoulos Alessandro Martini Alfredo Colosimo 《Journal of applied physiology》2003,95(6):2299-2305
A study of click-evoked otoacoustic emissions (CEOAEs) elicited at stimulation intensities from 35 to >80 dB was carried out by recurrence quantification analysis on signals from both normal and hearing-impaired subjects. In normal subjects, a clear scaling of determinism with increasing stimulation intensity was observed in the click intensity range from 41 to 59 dB. Outside that range and, in particular, above its upper end, subject-dependent features appeared in the form of different maximal levels of determinism. A comparative analysis of responses from hearing-impaired subjects with conductive hearing losses and sensorineural hearing losses suggested that the principal contributor to this behavior is the middle ear and allowed us to discriminate the two pathologies solely on the basis of CEOAEs. These observations are consistent with a simple phenomenological model of the auditory periphery in which different functional modules are sequentially recruited at increasing stimulus intensities, with a consequent rise in CEOAE coherence. 相似文献
94.
Virginia Morera-Pujol Paulo Catry Maria Magalhães Clara Péron José Manuel Reyes-González José Pedro Granadeiro Teresa Militão Maria P. Dias Daniel Oro Giacomo Dell'Omo Martina Müller Vitor H. Paiva Benjamin Metzger Verónica Neves Joan Navarro Georgios Karris Stavros Xirouchakis Jacopo G. Cecere Antonio Zamora-López Manuela G. Forero Ridha Ouni Mohamed Salah Romdhane Fernanda De Felipe Zuzana Zajková Marta Cruz-Flores David Grémillet Jacob González-Solís Raül Ramos 《Diversity & distributions》2023,29(1):19-38
95.
Stavros Fridas Anthony Trakatellis Evdokia Karagouni Eleni Dotsika Christos Himonas Pio Conti 《Molecular and cellular biochemistry》1994,136(1):59-63
4-Deoxypyridoxine (4-DPD) is a potent antagonist of Vitamin B6 coenzyme which inhibits IL-1, lymphocyte proliferation and has demonstrated that tollerance to skin grafts can be induced by administering splenic cells to pyridoxine-deficient mice. Chronic inflammation induced by dorsal injections of 200 l of a 140 saturated crystal solution of potassium permanganate (KMnO4) in mice treated or untreated with 4-DPD (400 g/dose), has been investigated. After 7 days all mice developed a subcutaneous granulomatous tissue indicative of a chronic inflammatory response, at the site of injection. KMnO4-treated mice injected intraperitoneally with 4-DPD (400 g/dose) on 5 consecutive days (the first at the same time of induction of the granuloma) show a significant decrease in size and weight of granuloma when compared to mice not treated with 4-DPD (Controls). In addition, in all mice treated with 4-DPD there was a strong inhibition of TNF in serum (P<0.01) and in supernatant fluids (P<0.05) from minced granuloma, while IL-6 was inhibited in the supernatant fluids (P<0.05) of minced granulomas but was not detected in the serum of treated and untreated mice. In this study we show for the first time the antiinflammatory effect of 4-DPD on chronic inflammation and the inhibitory effect of TNF and IL-6 generation in supernatant fluids from minced granulomas. 相似文献
96.
Secondary production of benthic invertebrates was estimated for Delaware Bay and coastal Delaware. Production and turnover ratios were highest in Delaware Bay (P = 46,572 mg AFDW m−2 yr−1, P:B = 6,O) and progressively lower at two coastal stations (P = 7,501 to 30,124 mg AFDW m−2 yr−1, P:B = 2.3 to 5.3, and P = 4,485 to 4,492mg AFDW m−2 yr−1, P:B =2.3 to 4.8). Production was inversely related to sediment particle size. Production in Delaware Bay was relatively evenly distributed between deposit feeding polychaetes and suspension feeding molluscs with a definite shift in production dominance to suspension feeding molluscs at the coastal stations. Moreover, crustaceans and echinoderms played a larger role in production at the coastal stations than in Delaware Bay. Concerns about the health of soft-bottom communities in Delaware Bay expressed earlier were not supported here. Finally, it was concluded that P and P: B from the Delaware Bay area were very similar to those obtained from other areas in the North Atlantic which agrees with estimates for other estuaries in the northern hemisphere. 相似文献
97.
98.
Stratakis CA 《Hormone research》2000,54(5-6):334-343
Peutz-Jeghers syndrome (PJS, #175200) and Carney complex (CNC, OMIM#160980) are the two most common multiple neoplasia syndromes associated with lentiginosis. Both disorders are inherited in an autosomal dominant manner and they have recently been elucidated at the molecular level. PJS and CNC share manifestations with Cowden syndrome (or Cowden disease) (CS, OMIM#158350) and Bannayan-Riley-Ruvalcaba syndrome (BRR, OMIM#153480). The endocrine tumors of CS and PJS, which could classify these disorders as variant types of multiple endocrine neoplasias (MENs), are not present in most CS and BRR patients, but lentigines are shared by PJS, CNC and BRR. The serine-threonine kinase STK11 (or LKB1), located on 19p13, is mutated in more than half of all PJS kindreds. The R1alpha subunit of c-AMP-dependent protein kinase A, located on 17q22-24, is mutated in 40% of CNC kindreds. The protein phosphatase PTEN is mutated in most cases of CS and in almost 50% of BRR kindreds, despite significant clinical heterogeneity in these syndromes. The molecular elucidation of the lentiginoses and their related syndromes identifies new pathways of growth control and cellular regulation that are important for endocrine signaling, tumorigenesis, cutaneous function and embryonic development. 相似文献
99.
An in vitro model system was developed to study structure-function relationships and the development of structural and mechanical anisotropy in collagenous tissues. Fibroblast-populated collagen gels were constrained either biaxially or uniaxially. Gel remodeling, biaxial mechanical properties, and collagen orientation were determined after 72 h of culture. Collagen gels contracted spontaneously in the unconstrained direction, uniaxial mechanical constraints produced structural anisotropy, and this structural anisotropy was associated with mechanical anisotropy. Cardiac and tendon fibroblasts were compared to test the hypothesis that tendon fibroblasts should generate greater anisotropy in vitro. However, no differences were seen in either structure or mechanics of collagen gels populated with these two cell types, or between fibroblast populated gels and acellular gels. This study demonstrates our ability to control and measure the development of structural and mechanical anisotropy due to imposed mechanical constraints in a fibroblast-populated collagen gel model system. While imposed constraints were required for the development of anisotropy in this system, active remodeling of the gel by fibroblasts was not. This model system will provide a basis for investigating structure-function relationships in engineered constructs and for studying mechanisms underlying the development of anisotropy in collagenous tissues. 相似文献
100.
Timothy Sakellaridis Stavros Mathioulakis Christos Antiochos 《International Seminars in Surgical Oncology : ISSO》2005,2(1):19