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Various Tissues (various + tissue)
Selected AbstractsThe birth and postnatal development of purinergic signallingACTA PHYSIOLOGICA, Issue 2 2010G. Burnstock Abstract The purinergic signalling system is one of the most ancient and arguably the most widespread intercellular signalling system in living tissues. In this review we present a detailed account of the early developments and current status of purinergic signalling. We summarize the current knowledge on purinoceptors, their distribution and role in signal transduction in various tissues in physiological and pathophysiological conditions. [source] Sef is synexpressed with FGFs during chick embryogenesis and its expression is differentially regulated by FGFs in the developing limbDEVELOPMENTAL DYNAMICS, Issue 2 2005Haggar Harduf Abstract The signaling pathways leading to growth and patterning of various organs are tightly controlled during the development of any organism. These control mechanisms usually involve the utilization of feedback- and pathway-specific antagonists where the pathway induces the expression of its own antagonist. Sef is a feedback antagonist of fibroblast growth factor (FGF) signaling, which has been identified recently in zebrafish and mammals. Here, we report the isolation of chicken Sef (cSef) and demonstrate the conserved nature of the regulatory relationship with FGF signaling. In chick embryos, Sef is expressed in a pattern that coincides with many known sites of FGF signaling. In the developing limb, cSef is expressed in the mesoderm underlying the apical ectodermal ridge (AER) in the region known as the progress zone. cSef message first appeared after limb budding and AER formation. Expression was intense at stages of rapid limb outgrowth, and gradually decreased to almost undetectable levels when differentiation was clearly apparent. Gain- and loss-of-function experiments showed that FGFs differentially regulate the expression of cSef in various tissues. Thus, removal of the AER down-regulated cSef expression, and FGF2 but not FGF4 or FGF8 beads substituted for the AER in maintaining cSef expression. At sites where cSef is not normally expressed, FGF4 and FGF2, but not FGF8 beads, induced cSef expression. Our results demonstrate the complexity of cSef regulation by FGFs and point to FGF2 as a prime candidate in regulating cSef expression during normal limb development. The spatiotemporal pattern of cSef expression during limb development suggests a role for cSef in regulating limb outgrowth but not limb initiation. Developmental Dynamics 233:301,312, 2005. © 2005 Wiley-Liss, Inc. [source] Acetyl-CoA carboxylases 1 and 2 show distinct expression patterns in rats and humans and alterations in obesity and diabetesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2009Sebastian Kreuz Abstract Background Acetyl-CoA carboxylases (ACC) 1 and 2 are central enzymes in lipid metabolism. To further investigate their relevance for the development of obesity and type 2 diabetes, expression of both ACC isoforms was analyzed in obese fa/fa Zucker fatty and Zucker diabetic fatty rats at different ages in comparison to Zucker lean controls. Methods ACC1 and ACC2 transcript levels were measured by quantitative real-time polymerase chain reaction in metabolically relevant tissues of Zucker fatty, Zucker diabetic fatty and Zucker lean control animals. Quantitative real-time polymerase chain reaction was also applied to measure ACC tissue distribution in human tissues. For confirmation on a protein level, quantitative mass spectrometry was used. Results Disease-related transcriptional changes of both ACC isoforms were observed in various tissues of Zucker fatty and Zucker diabetic fatty rats including liver, pancreas and muscle. Changes were most prominent in oxidative tissues of diabetic rats, where ACC2 was significantly increased and ACC1 was reduced compared with Zucker lean control animals. A comparison of the overall tissue distribution of both ACC isoforms in humans and rats surprisingly revealed strong differences. While in rats ACC1 was mainly expressed in lipogenic and ACC2 in oxidative tissues, ACC2 was predominant in oxidative and lipogenic tissues in humans. Conclusion Our data support a potential role for both ACC isoforms in the development of obesity and diabetes in rats. However, the finding of fundamental species differences in ACC1 and ACC2 tissue expression might be indicative for different functions of both isoforms in humans and rats and raises the question to which degree these models are predictive for the physiology and pathophysiology of lipid metabolism in humans. Copyright © 2009 John Wiley & Sons, Ltd. [source] Adrenomedullin and diabetes mellitusDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2001Eva Ruzicska Abstract Adrenomedullin (AM) is a novel 52 amino acid peptide hormone, originally isolated from human pheochromocytoma. AM acts as a local autocrine and/or paracrine vasoactive hormone and has vasodilator and blood pressure lowering properties. AM as a vasodilative molecule protects the vascular wall but its exact role is still uncertain. AM is considered to play an important endocrine role in various tissues in maintaining electrolyte and fluid homeostasis. Its plasma concentration in healthy conditions is low. In hypertension, chronic renal failure and congestive heart failure its plasma concentration increases in a parallel manner with the severity of the disease. It is assumed that this peptide plays an important role in physiological and pathological conditions compensating the effects of vasoconstrictive molecules. Investigations have proven that in diabetic angiopathies the levels and production of vasoconstrictive factors and AM are increased, while other relaxing substances such as nitric oxide (NO) are decreased. It is still uncertain whether the increased release of AM is a compensatory mechanism or a coincidental event. Although the precise role of AM in the pathogenesis of diabetic complications is still to be elucidated, the altered concentration of AM in diabetes could indicate a certain interaction between AM induction and vascular function. Hence, the induction of vascular AM can be a new target of therapeutic approach to diabetic complications. Copyright © 2001 John Wiley & Sons, Ltd. [source] Mechanism of DNA damage by cadmium and interplay of antioxidant enzymes and agentsENVIRONMENTAL TOXICOLOGY, Issue 2 2007Veera L. D. Badisa Abstract Cadmium is an environmental toxicant, which causes cancer in different organs. It was found that it damages DNA in the various tissues and cultured cell lines. To investigate the mechanism of DNA damage, we have studied the effect of cadmium-induced DNA damage in plasmid pBR322 DNA, and the possible ameliorative effects of antioxidative agents under in vitro conditions. It was observed that cadmium alone did not cause DNA damage. However, it caused DNA damage in the presence of hydrogen peroxide, in a dose dependent manner, because of production of hydroxyl radicals. Findings from this study show the conversion of covalently closed circular double-stranded pBR 322 DNA to the open circular and linear forms of DNA when treated with 10 ,M cadmium and various concentrations of H2O2. The conversion was due to nicking in DNA strands. The observed rate of DNA strand breakage was dependent on H2O2 concentration, temperature, and time. Metallothionein I failed to prevent cadmium-induced DNA nicking in the presence of H2O2. Of the two antioxidant enzymes (catalase and superoxide dismutase) studied, only catalase conferred significant (50,60%) protection. EDTA and DMSO exhibited protection similar to catalase, while mannitol showed only about 20% protection against DNA damage. Ethyl alcohol failed to ameliorate cadmium-induced DNA strands break. From this study, it is plausible to infer that cadmium in the presence of hydrogen peroxide causes DNA damage probably by the formation of hydroxyl ions. These results may indicate that cadmium in vivo could play a major role in the DNA damage induced by oxidative stress. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 144,151, 2007. [source] Competitive binding comparison of endocrine-disrupting compounds to recombinant androgen receptor from fathead minnow, rainbow trout, and humanENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2007Vickie S. Wilson Abstract Typically, in vitro hazard assessments for the identification of endocrine-disrupting compounds (EDCs), including those outlined in the Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC) Tier 1 Screening protocols, utilize mammalian receptors. Evidence, however, exists that fish sex steroid hormone receptors differ from mammalian receptors both structurally and in their binding affinities for some steroids and environmental chemicals. Most of the binding studies to date have been conducted using cytosolic preparations from various tissues. In the present study, we compare competitive binding of a set of compounds to full-length recombinant rainbow trout androgen receptor , (rtAR), fathead minnow androgen receptor (fhAR), and human androgen receptor (hAR), each expressed in COS cells. Saturation binding and subsequent Scatchard analysis using [3H]R1881, a high-affinity synthetic androgen, revealed an equilibrium dissociation constant (Kd) of 0.11 nM for the rtAR, 1.8 nM for the fhAR, and 0.84 nM for the hAR. Compounds, including endogenous and synthetic steroids, known mammalian antiandrogens, and environmental compounds, were tested for competitive binding to each of the three receptors. Overall, agreement existed across receptors as to binding versus nonbinding for all compounds tested in this study. Minor differences, however, were found in the relative order of binding of the compounds to the individual receptors. Studies such as these will facilitate the identification of EDCs that may differentially affect specific species and aid in the development and support of future risk assessment protocols. [source] Relationship between soil copper content and copper content of selected crop plants in central ChileENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2001Ricardo Badilla-Ohlbaum Abstract A survey of copper levels in agricultural soils of central Chile revealed two soil clusters,one with a mean copper level of 162 mg/kg and one with a mean copper level of 751 mg/kg of soil. Samples of soils from both soil clusters were characterized on the basis of physicochemical characteristics, and copper extractability was compared by saturation and CaCl2 extraction as well as an acid-leaching procedure (TCLP). We also measured the copper content of various tissues of tomato (Lycopersicon esculentum) and onion (Allium cepa) crops growing on these soils. Other than copper levels, soils from the two clusters were quite similar, with slightly greater levels of molybdenum and cadmium in the high-copper soils. Within each cluster, extracted copper levels and total soil copper levels were not correlated. However, the three extraction procedures solubilized significantly more copper from the high-Cu soils. Mineralogical characterization of the soil particles and depth profiles of soil metal levels in a subsample of sites suggested that highly insoluble copper ore and mining wastes might account for the high copper levels. Neither total nor extractable copper levels allowed statistical prediction of the levels of copper in plant tissue. The edible tissues of both crops had the same mean copper content, regardless of the copper soil level. However, copper contents of stems and leaves were significantly higher for plants growing on the high-Cu soils. These results show that in these soils, high copper levels are associated with very insoluble copper species and thus low bioavailability of copper to crop plants. [source] Association of ABCB1 genetic variants 3435C>T and 2677G>T to ABCB1 mRNA and protein expression in brain tissue from refractory epilepsy patientsEPILEPSIA, Issue 9 2008Igor Mosyagin Summary Purpose: There is evidence from studies in rodents that P-glycoprotein (P-gp) overexpression is implicated in the causation of refractory epilepsy. Genetic variants in the human ABCB1 (MDR1) gene were shown to affect the expression levels of the transporter in various tissues and to be associated with refractory epilepsy. However, the effect of the genetic variants on the P-gp level in epileptogenic brain tissue is poorly investigated. In the present study, we examined the impact of putatively functional polymorphisms 3435C>T and 2677G>T in the ABCB1 gene on the ABCB1 mRNA expression and P-gp content in human brain tissue from epileptogenic foci of the patients with refractory epilepsy. Methods: Fresh brain tissue specimens were obtained from therapy-refractory epilepsy patients during neurosurgery of the epileptogenic focus. We determined the ABCB1 mRNA expression in 23 samples using 5, exonuclease-based real-time polymerase chain reaction (PCR) as well as the P-gp content in 32 samples determined by immunohistochemistry, genotyping was performed by PCR/restriction fragment length polymorphism (RFLP). Results: There was lack of association of 3435C>T and 2677G>T as well as diplotype configurations on ABCB1 mRNA expression and P-gp content in epileptogenic brain tissues. Conclusions: We cannot exclude an association of ABCB1 variants on P-gp function, but our results suggest that brain ABCB1 mRNA and protein expression is not substantially influenced by major ABCB1 genetic variants thus explaining in part results from case-control studies obtaining lack of association of ABCB1 polymorphisms to the risk of refractory epilepsy. [source] The canonical Wnt signaling pathway plays an important role in lymphopoiesis and hematopoiesisEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2008Frank Abstract The evolutionarily conserved canonical Wnt-,-catenin-T cell factor (TCF)/lymphocyte enhancer binding factor (LEF) signaling pathway regulates key checkpoints in the development of various tissues. Therefore, it is not surprising that a large body of gain-of-function and loss-of-function studies implicate Wnt-,-catenin signaling in lymphopoiesis and hematopoiesis. In contrast, recent papers have reported that Mx-Cre-mediated conditional deletion of ,-catenin and/or its homolog ,-catenin (plakoglobin) did not impair hematopoiesis or lymphopoiesis. However, these studies also report that TCF reporter activity remains active in ,-catenin- and ,-catenin-deficient hematopoietic stem cells and all cells derived from these precursors, indicating that the canonical Wnt signaling pathway was not abrogated. Therefore, these studies in fact show that the canonical Wnt signaling pathway is important in hematopoiesis and lymphopoiesis, even though the molecular basis for the induction of the reporter activity is currently unknown. In this perspective, we provide a broad background to the field with a discussion of the available data and create a framework within which the available and future studies may be evaluated. [source] Requirement of the tumour suppressor APC for the clustering of PSD-95 and AMPA receptors in hippocampal neuronsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2007Atsushi Shimomura Abstract Mutations in the adenomatous polyposis coli (APC) gene are associated with familial adenomatous polyposis and sporadic colorectal tumours. The APC gene is expressed ubiquitously in various tissues, especially throughout the large intestine and central nervous system (CNS). In the CNS, the expression of the APC protein is highest during embryonic and early postnatal development. APC associates through its C-terminal region with postsynaptic density (PSD)-95, a neuronal protein that participates in synapse development. Here, we examined the involvement of APC in synaptogenesis. In cultured hippocampal neurons, both overexpression of a dominant-negative construct that disrupts the APC,PSD-95 interaction and knockdown of APC expression using small interfering RNA (siRNA) inhibited the clustering of PSD-95 and a glutamate receptor subunit, and reduced alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionate (AMPA)-induced activity of AMPA receptors; however, the clustering of an N -methyl- d -aspartate (NMDA) receptor subunit was unaffected. These results are suggestive of APC involvement in the development of glutamatergic synapses. [source] Osteopontin and the skin: multiple emerging roles in cutaneous biology and pathologyEXPERIMENTAL DERMATOLOGY, Issue 9 2009Franziska Buback Abstract:, Osteopontin (OPN) is a glycoprotein expressed by various tissues and cells. The existence of variant forms of OPN as a secreted (sOPN) and intracellular (iOPN) protein and its modification through post-translational modification and proteolytic cleavage explain its broad range of functions. There is increasing knowledge which receptors OPN isoforms can bind to and which signaling pathways are activated to mediate different OPN functions. sOPN interacts with integrins and CD44, mediates cell adhesion, migration and tumor invasion, and has T helper 1 (Th1) cytokine functions and anti-apoptotic effects. iOPN has been described to regulate macrophage migration and interferon-, secretion in plasmacytoid dendritic cells. Both sOPN and iOPN, through complex functions for different dendritic cell subsets, participate in the regulation of Th cell lineages, among them Th17 cells. For skin disease, OPN from immune cells and tumor cells is of pathophysiological relevance. OPN is secreted in autoimmune diseases such as lupus erythematosus, and influences inflammation of immediate and delayed type allergies and granuloma formation. We describe that OPN is overexpressed in psoriasis and propose a model to study OPN function in psoriatic inflammation. Through cytokine functions, OPN supports immune responses against Mycobacteria and viruses such as herpes simplex virus. OPN is also implicated in skin tumor progression. Overexpression of OPN influences invasion and metastasis of melanoma and squamous cell carcinoma cells, and OPN expression in melanoma is a possible prognostic marker. As OPN protein preparations and anti-OPN antibodies may be available in the near future, in-depth knowledge of OPN functions may open new therapeutic approaches for skin diseases. [source] The 21st century renaissance of the basophil?EXPERIMENTAL DERMATOLOGY, Issue 11 2006Current insights into its role in allergic responses, innate immunity Abstract:, Basophils and mast cells express all the three subchains of the high-affinity immunoglobulin E (IgE) receptor Fc,RI and contain preformed histamine in the cytoplasmic granules. However, it is increasingly clear that these cells play distinct roles in allergic inflammatory disease. Despite their presence throughout much of the animal kingdom, the physiological function of basophils remains obscure. As rodent mast cells are more numerous than basophils, and generate an assortment of inflammatory cytokines, basophils have often been regarded as minor players in allergic inflammation. In humans, however, basophils are the prime early producers of interleukin (IL)-4 and IL-13, T helper (Th)2-type cytokines crucial for initiating and maintaining allergic responses. Basophils also express CD40 ligand which, in combination with IL-4 and IL-13, facilitates IgE class switching in B cells. They are the main cellular source for early IL-4 production, which is vital for the development of Th2 responses. The localization of basophils in various tissues affected by allergic inflammation has now been clearly demonstrated by using specific staining techniques and the new research is shedding light on their selective recruitment to the tissues. Finally, recent studies have shown that basophil activation is not restricted to antigen-specific IgE crosslinking, but can be caused in non-sensitized individuals by a growing list of parasitic antigens, lectins and viral superantigens, binding to non-specific IgE antibodies. This, together with novel IgE-independent routes of activation, imparts important new insights into the potential role of basophils in both adaptive and innate immunity. [source] Antioxidant and anti-inflammatory activities of melanocortin peptidesEXPERIMENTAL DERMATOLOGY, Issue 9 2004J. W. Haycock ,-Melanocyte-stimulating hormone (,-MSH) has previously been identified as a potent anti-inflammatory agent in various tissues including the skin. It operates by binding to the melanocortin-1 receptor (MC-1R) which results in the elevation of cyclic AMP. ,-MSH opposes the action of several proinflammatory cytokines including tumour necrosis factor-, (TNF-,). We have shown that ,-MSH can inhibit TNF-,-stimulated activation of nuclear factor-,B (NF-,B) in human cultured melanocytes, melanoma cells, keratinocytes, fibroblasts, Schwann cells and olfactory ensheathing cells. It also inhibits TNF-,-stimulated upregulation of intercellular adhesion molecule-1 (ICAM-1) in many of these cells and can inhibit peroxide-stimulated activation of glutathione peroxidase, suggesting an antioxidant role. ,-MSH is also able to stimulate intracellular calcium release in keratinocytes and fibroblasts (which do not readily show detectible cyclic AMP elevation) but only in the presence of PIA (an adenosine agonist). The carboxyl terminal tripeptides KPV/KP-D-V are reported to be the minimal sequences necessary to convey anti-inflammatory potential, but evidence on how they act is not fully known. Stable transfection of Chinese hamster ovary cells with MC-1R suggests that the KPV peptides operate by this receptor, at least by elevating intracellular calcium. Elevation of cyclic AMP by these tripeptides has not been detected in any cell type studied; however, calcium elevation can inhibit TNF-,-stimulated NF-,B activity (as for cyclic AMP). In conclusion, the MSH peptides convey anti-inflammatory and antioxidant activity in many cell types in skin and nerve, by counteracting proinflammatory cytokine signalling. The KPV peptides appear to act functionally via the MC-1R and can also elevate intracellular calcium. [source] Myocyte enhancer factor 2 (MEF2) is a key modulator of the expression of the prothoracicotropic hormone gene in the silkworm, Bombyx moriFEBS JOURNAL, Issue 15 2005Kunihiro Shiomi Prothoracicotropic hormone (PTTH) plays a central role in controlling molting, metamorphosis, and diapause termination in insects by stimulating the prothoracic glands to synthesize and release the molting hormone, ecdysone. Using Autographa californica nucleopolyhedrovirus (AcNPV)-mediated transient gene transfer into the central nervous sytem (CNS) of the silkworm, Bombyx mori, we identified two cis -regulatory elements that participate in the decision and the enhancement of PTTH gene expression in PTTH-producing neurosecretory cells (PTPCs). The cis -element mediating the enhancement of PTTH gene expression binds the transcription factor Bombyx myocyte enhancer factor 2 (BmMEF2). The BmMEF2 gene was expressed in various tissues including the CNS. In brain, the BmMEF2 gene was expressed at elevated levels in two types of lateral neurosecretory cells, namely PTPCs and corazonin-like immunoreactive lateral neurosecretory cells. Overexpression of BmMEF2 cDNA caused an increase in the transcription of PTTH. Therefore, BmMEF2 appears to be particularly important in the brain where it is responsible for the differentiation of lateral neurosecretory cells, including the enhancement of PTTH gene expression. This is the first report to identify a target gene of MEF2 in the invertebrate nervous system. [source] Cloning and expression of murine enzymes involved in the salvage pathway of GDP- l -fucoseFEBS JOURNAL, Issue 1 2004GDP- l -fucose pyrophosphorylase, l -fucokinase In the salvage pathway of GDP- l -fucose, free cytosolic fucose is phosphorylated by l -fucokinase to form l -fucose-1-phosphate, which is then further converted to GDP- l -fucose in the reaction catalyzed by GDP- l -fucose pyrophosphorylase. We report here the cloning and expression of murine l -fucokinase and GDP- l -fucose pyrophosphorylase. Murine l -fucokinase is expressed as two transcripts of 3057 and 3270 base pairs, encoding proteins of 1019 and 1090 amino acids with predicted molecular masses of 111 kDa and 120 kDa respectively. Only the longer splice variant of l -fucokinase was enzymatically active when expressed in COS-7 cells. Murine GDP- l -fucose pyrophosphorylase has an open reading frame of 1773 base pairs encoding a protein of 591 amino acids with a predicted molecular mass of 65.5 kDa. GDP- l -fucose, the reaction product of GDP- l -pyrophosphorylase, was identified by HPLC and MALDI-TOF MS analysis. The tissue distribution of murine l -fucokinase and GDP- l -fucose pyrophosphorylase was investigated by quantitative real time PCR, which revealed high expression of l -fucokinase and GDP- l -fucose pyrophosphorylase in various tissues. The wide expression of both enzymes can also be observed from the large amount of data collected from a number of expressed sequence tag libraries, which indicate that not only the de novo pathway alone, but also the salvage pathway, could have a significant role in the synthesis of GDP- l -fucose in the cytosol. [source] Regulated expression and dynamic changes in subnuclear localization of mammalian Rad18 under normal and genotoxic conditionsGENES TO CELLS, Issue 8 2005Sadaharu Masuyama Rad18 plays a crucial role in postreplication repair in both lower eukaryotes and higher eukaryotes. However, regulation of the Rad18 expression in higher eukaryotes is largely unknown. We found that the RAD18 transcript is expressed ubiquitously in various tissues and very highly in the testis in mammals. Although human RAD18 (hRAD18) transcription levels fluctuate during the cell cycle, being maximal in the late S and minimal in the early G1, the protein levels remain constant throughout the cell cycle. Following UV-irradiation, hRAD18 transcription levels decrease significantly, but Rad18 protein levels change little. The protein levels are maintained at least in part by enhanced translation rates. hRad18 localizes in the nucleus in two forms: a diffused form and a condensed form forming nuclear dots. These nuclear dots disperse rapidly in the nucleoplasm after treatments with various genotoxic agents, resulting in an enhancement of the intranuclear Rad18 concentration of the diffused form. No de novo protein synthesis is required for this process. These results suggest that in higher eukaryotes, the maintenance and dynamic translocation of Rad18 protein is important for postreplication repair. [source] Expression and distribution of ZO-3, a tight junction MAGUK protein, in mouse tissuesGENES TO CELLS, Issue 11 2003Akihito Inoko Background:, Three related MAGUK proteins, ZO-1, ZO-2 and ZO-3, are concentrated at the cytoplasmic surface of tight junctions. However, in contrast to ZO-1/ZO-2, our knowledge of the expression and distribution of ZO-3 is still fragmentary, partly due to a lack of antibodies that specifically distinguish ZO-3 from ZO-1 and ZO-2. Results:, We generated one pAb and one mAb that specifically recognized ZO-3 on Western blotting. The immunofluorescence signals obtained with these antibodies completely disappeared from ZO-1/ZO-2-positive tight junctions in the liver of ZO-3-deficient mice, indicating that the antibodies can be used to localize ZO-3 in various tissues by immunofluorescence microscopy. Immunofluorescence microscopy with these antibodies revealed that ZO-3 was concentrated at tight junctions in various types of epithelium, but not in endothelium or at cadherin-based cell-cell adhesion sites (spot adherens junctions of fibroblasts and intercalated discs of cardiac muscle cells), where ZO-1 and ZO-2 are concentrated. Conclusions:, We conclude that ZO-3 is expressed in a more epithelium-specific manner than ZO-1 and ZO-2. These observations provide for a better understanding of the functions of tight junction-associated MAGUKs. [source] Generation of a mouse with conditionally activated signaling through the BMP receptor, ALK2,GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 4 2006Tomokazu Fukuda Abstract BMP signaling plays pleiotropic roles in various tissues. Transgenic mouse lines that overexpress BMP signaling in a tissue-specific manner would be beneficial; however, production of each tissue-specific transgenic mouse line is labor-intensive. Here, using a Cre-loxP system, we generated a conditionally overexpressing mouse line for BMP signaling through the type I receptor ALK2 (alternatively known as AVCRI, ActRI, or ActRIA). By mating this line with Cre-expression mouse lines, Cre-mediated recombination removes an intervening floxed lacZ expression cassette and thereby permits the expression of a constitutively active form of Alk2 (caAlk2) driven by a ubiquitous promoter, CAG. Tissue specificity of Cre recombination was monitored by a bicistronically expressed EGFP following Alk2 cDNA. Increased BMP signaling was confirmed by ectopic phosphorylation of SMAD1/5/8 in the areas where Cre recombination had occurred. The conditional overexpression system described here provides versatility in investigating gene functions in a tissue-specific manner without having to generate independent tissue-specific transgenic lines. genesis 44:159,167, 2006. Published 2006 Wiley-Liss, Inc. [source] Changes of telomere length with agingGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2010Kaiyo Takubo We reviewed our methodology and results of telomere measurements, with reference to telomere length and aging. Human tissues always showed telomere shortening with age, except for the brain and myocardium. Yearly rates of telomere length reduction in various tissues were mostly within the range 20,60 bp, and thus compatible with that expected from only one round of mitosis. It was suggested that when telomeres were found to be longer in any specific organ in a given individual, then the other organs in that individual would also have longer telomeres. Using the quantitative fluorescence in situ hybridization (Q-FISH) method for telomere measurement, we were able to measure the telomere lengths of various cell types within tissues. Here we summarize the results obtained for various cell types in the stomach, tongue and breast. Our Q-FISH method using our original software program "Tissue Telo" is excellent for measuring telomere lengths using tissue sections and PNA probes. Geriatr Gerontol Int 2010; 10 (Suppl. 1): S197,S206. [source] Regulation of epithelial cell cytokine responses by the ,3,1 integrinIMMUNOLOGY, Issue 2 2003Farah D. Lubin Summary Epithelial cells (EC) from various tissues can produce important cytokines and chemokines when stimulated by proinflammatory cytokines. These EC also receive signals from cell surface integrins, like the ,3,1 integrin, which is important in cell migration and wound healing of epithelial monolayers. However, little is known of the effect of integrin signals on cytokine responses by EC. Colonic Caco-2 cells treated with an anti-,3 integrin antibody prior to stimulation with the proinflammatory cytokine interleukin (IL)-1 yielded suppressed levels of mRNA and secreted IL-6, IL-8 and monocyte chemoattractant protein-1 as compared to cells treated with normal mouse immunoglobulin G. Lung A549 cells also showed a similar suppression of cytokine secretion. Likewise, treatment of the Caco-2 cells with the same antibody suppressed tumour necrosis factor-,-stimulated IL-6 secretion. Fab fragments of the anti-,3 integrin antibody did not induce the suppressive effect but did block the suppressive effect of the whole antibody suggesting that the effect of the antibody required cross-linking of the integrins. Finally, culture of the Caco-2 cells on laminin type 5 (the major ligand for this integrin) yielded depressed levels of IL-1-induced IL-6 secretion as compared to cells on laminin type 1. These data are the first indication that the ,3,1 integrin may cause a suppression of cytokine responses by EC which may be important in regulating the capacity of EC to respond during inflammation or wound healing. [source] Human tissue distribution of paraoxonases 1 and 2 mRNAIUBMB LIFE, Issue 6 2010Bharti Mackness Abstract We have studied the distribution of mRNA for paraoxonases (PON) 1 and 2 in 24 human tissues using Gene Expression Panels. PON1 mRNA was restricted to adult kidney, liver, and colon as well as fetal liver, whereas PON2 mRNA was more widely distributed in adult human brain, heart, kidney, spleen, liver, colon, lung, small intestine, muscle, stomach, testis, placenta, salivary, thyroid and adrenal glands, pancreas, skin, and bone marrow, as well as fetal brain and liver. PON2 mRNA was not found in ovary, uterus, or plasma leukocytes using the panels. However, using real time PCR, we found PON2 mRNA expression in human plasma leukocytes. There were differences between the tissue distribution of mRNAs found in this study and the immunohistochemical localization of the PON1 and PON2 proteins reported previously. In particular, PON1 protein is much more widely distributed than its mRNA, possibly indicating the delivery of PON1 to various tissues by HDL. In addition, differences between PON2 mRNA and protein distributions could be due to missence mutations in the PON2 gene, causing nontranslation of mRNA to protein in some tissues. © 2010 IUBMB IUBMB Life, 62(6): 484,486, 2010 [source] Two C-Terminal Variants of NBC4, a New Member of the Sodium Bicarbonate Cotransporter Family: Cloning, Characterization, and LocalizationIUBMB LIFE, Issue 1 2000Alexander Pushkin Abstract We report the cloning, characterization, and chromosomal assignment of a new member of the sodium bicarbonate cotransporter (NBC) family, NBC4. The NBC4 gene was mapped to chromosome 2p13 and is a new candidate gene for Alstrom syndrome. Two variants of the transporter have been isolated from human testis and heart, which differ in their C termini. NBC4a encodes a 1137-residue polypeptide and is widely expressed in various tissues, including liver, testis, and spleen. NBC4b is identical to NBC4a except that it has a 16-nucleotide insert, creating a C-terminal frame shift. NBC4b encodes a 1074-residue polypeptide and is highly expressed in heart. Amino acids 1-1046 are common to both NBC4 variants. NBC4a has two protein-interacting domains that are lacking in NBC4b: a proline-rich sequence, PPPSVIKIP (amino acids 1102-1110), and a consensus PDZ-interacting domain, SYSL (1134-1137). NBC4b lacks the stretch of charged residues present in the C terminus of NBC4a and other members of the NBC family.Unlike other members of the NBC family, both NBC4a and NBC4b have a unique glycine-rich region (amino acids 440- 469). In comparison with other members of the bicarbonate transport superfamily, NBC4a and NBC4b are most similar structurally to the electrogenic sodium bicarbonate cotransporters (NBC1). [source] Nitric Oxide: The "Second Messenger" of InsulinIUBMB LIFE, Issue 5 2000Nighat N. Kahn Abstract Incubation of various tissues, including heart, liver, kidney, muscle, and intestine from mice and erythrocytes or their membrane fractions from humans, with physiologic concentration of insulin resulted in the activation of a membrane-bound nitric oxide synthase (NOS). Activation of NOS and synthesis of NO were stimulated by the binding of insulin to specific receptors on the cell surface. A Lineweaver-Burk plot of the enzymatic activity demonstrated that the stimulation of NOS by insulin was related to the decrease in the Km for L-arginine, the substrate for NOS, with a simultaneous increase of Vmax. Addition of NG-nitro-L-arginine methyl ester (LNAME), a competitive inhibitor of NOS, to the reaction mixture completely inhibited the hormone-stimulated NO synthesis in all tissues. Furthermore, NO had an insulin-like effect in stimulating glucose transport and glucose oxidation in muscle, a major site for insulin action. Addition of NAME to the reaction mixture completely blocked the stimulatory effect of insulin by inhibiting both NO production and glucose metabolism, without affecting the hormone-stimulated tyrosine or phosphatidylinositol 3-kinases of the membrane preparation. Injection of NO in alloxan-induced diabetic mice mimicked the effect of insulin in the control of hyperglycemia (i.e., lowered the glucose content in plasma). However, injection of NAME before the administration of insulin to diabetic-induced and nondiabetic mice inhibited not only the insulin-stimulated increase of NO in plasma but also the glucose-lowering effect of insulin. [source] Milk consumption: aggravating factor of acne and promoter of chronic diseases of Western societiesJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 4 2009Bodo Melnik Summary Consumption of cow's milk and cow's milk protein result in changes of the hormonal axis of insulin, growth hormone and insulin-like growth factor-1(IGF-1) in humans. Milk consumption raises IGF-1 serum levels in the perinatal period, adolescence and adulthood. During puberty with the physiological onset of increased secretion of growth hormone, IGF-1 serum levels increase and are further enhanced by milk consumption. IGF-1 is a potent mitogen; after binding to its receptor in various tissues, it induces cell proliferation and inhibits apoptosis. Keratinocytes and sebocytes, as well as the androgen-synthesizing adrenals and gonads, are stimulated by IGF-1. The epidemic incidence of adolescent acne in Western milk-consuming societies can be explained by the increased insulin- and IGF-1-stimulation of sebaceous glands mediated by milk consumption. Acne can be regarded as a model for chronic Western diseases with pathologically increased IGF-1-stimulation. Many other organs, such as the thymus, bones, all glands, and vascular smooth muscle cells as well as neurons are subject to this abnormally increased hormonal stimulation. The milk-induced change of the IGF-1-axis most likely contributes to the development of fetal macrosomia, induction of atopy, accelerated linear growth, atherosclerosis, carcinogenesis and neurodegenerative diseases. Observations of molecular biology are supported by epidemiologic data and unmask milk consumption as a promoter of chronic diseases of Western societies. [source] Influence of subacute treatment of some plant growth regulators on serum marker enzymes and erythrocyte and tissue antioxidant defense and lipid peroxidation in ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 4 2006Ismail Celik Abstract This study aims to investigate the effects of the plant growth regulators (PGRs) (2,3,5-triiodobenzoic acid (TIBA), Naphthaleneacetic acid (NAA), and 2,4-dichlorofenoxyacetic acid (2,4-D)) on serum marker enzymes (aspartate aminotransferase (AST), alanin aminotransferase (ALT), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH)), antioxidant defense systems (reduced glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), glutathione-S-transferase (GST), and catalase (CAT)), and lipid peroxidation content (malondialdehyde = MDA) in various tissues of rats. 50 and 100 ppm of PGRs as drinking water were administered orally to rats (Sprague,Dawley albino) ad libitum for 25 days continuously. The PGRs treatment caused different effects on the serum marker enzymes, antioxidant defense systems, and the MDA content in experimented rats compared to controls. Results showed that TIBA caused a significant decrease in serum AST activity with both the dosage whereas serum CPK was significantly increased with 100 ppm dosage of TIBA. Meanwhile, serum AST, CPK, and LDH activities were significantly increased with both dosage of NAA and 2,4-D. The lipid peroxidation end-product MDA significantly increased in the all tissues treated with both dosages of PGRs without any change in the brain and erythrocyte of rats treated with both the dosages of 2,4-D. The GSH depletion in the kidney and brain tissues of rats treated with both dosages of PGRs was found to be significant. Furthermore, the GSH depletion in the erythrocyte of rats treated with both dosages of PGRs except 50 ppm dosage of 2,4-D was significant too. Also, the GSH level in the liver was significantly depleted with 50 ppm of 2,4-D and NAA, whereas the GSH depletion in the same tissue did not significantly change with the treatment. The activity of antioxidant enzymes was also seriously affected by PGRs; SOD significantly decreased in the liver, heart, kidney, and brain of rats treated with both dosages of NAA, whereas the SOD activity in the erythrocytes, liver, and heart was either significantly decreased or not changed with two doses of 2,4-D and TIBA. Although the CAT activity significantly increased in the erythrocyte and brain of rats treated with both doses of PGRs, it was not changed in the liver, heart, and kidney. Meanwhile, the ancillary enzyme GR activity significantly increased in the brain, heart, and liver but decreased in the erythrocyte and kidney of rats treated with both doses of PGRs. The drug-metabolizing enzyme GST activity significantly increased in the heart and kidney but decreased in the brain and erythrocytes of rats treated with both dosages of PGRs. As a conclusion, the results indicate that PGRs might affect antioxidant potential enzymes, the activity of hepatic damage enzymes, and lipid peroxidation dose independently. Also, the rats resisted to oxidative stress via antioxidant mechanism but the antioxidant mechanism could not prevent the increases in lipid peroxidation in rat's tissues. These data, along with the determined changes, suggest that PGRs produced substantial systemic organ toxicity in the erythrocyte, liver, brain, heart, and kidney during the period of a 25-day subacute exposure. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:174,182, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20134 [source] Effects of benzo[a]pyrene on tissue activities of metabolizing enzymes and antioxidant system in normal and protein-malnourished ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 2 2003Osama A. Badary Abstract The effects of benzo[a]pyrene (B[a]P) on some drug-metabolizing and antioxidant systems in liver, lung, and stomach were investigated in normal and protein malnutrition (PM) rats. PM significantly inhibited tissue glutathione (GSH) content and increased hepatic lipid peroxidation. Cytochrome P450 isoform CYP1A1 was significantly increased in various tissues (42,73%). Also, lung glutathione S-transferase (GST) activity was significantly decreased (19%) in PM rats. On the other hand, B[a]P significantly induced tissue GSH of control and PM rats. Also, hepatic lipid peroxidation were significantly increased in control rats treated with B[a]P. Superoxide dismutase (SOD) activity was decreased by B[a]P treatment in PM rat stomach. B[a]P significantly induced both quinone reductase (QR) (in all tissues) and hepatic GST of control and PM rats. GST activity in PM rat liver was significantly higher than that of control rat liver after B[a]P treatment. Also, B[a]P induced hepatic CYP1A1 by 32-fold and 27-fold (P , 0.05) in control and PM rats, respectively. Stomach and hepatic UDP-glucuronosyltransferase activities were significantly decreased (34%) and increased (74%), respectively by B[a]P in PM rats. The results suggest that PM status has a modifying effect on the response of some antioxidant and metabolizing systems to a well-known carcinogen risk. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:86,91, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10064 [source] Neural crest-derived stem cells display a wide variety of characteristicsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 6 2009Narihito Nagoshi Abstract A recent burst of findings has shown that neural crest-derived stem cells (NCSCs) can be found in diverse mammalian tissues. In addition to their identification in tissues that are known to be derived from the neural crest, recent studies have revealed NCSCs in tissues that are not specifically derived from the neural crest, such as bone marrow. NCSCs can express a wide range of characteristics, and which properties are expressed mainly depends on their tissue sources and the ontogenic stage of the animal. The identification of NCSCs in various tissues opens an entirely new avenue of approach to developing autologous cell replacement therapies for use in regenerative medicine. In this review, we discuss the origin, migration, and lineage potential of NCSCs from various mammalian tissue sources. J. Cell. Biochem. 107: 1046,1052, 2009. © 2009 Wiley-Liss, Inc. [source] Rho exchange factor ECT2 is induced by growth factors and regulates cytokinesis through the N-terminal cell cycle regulator-related domains,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2003Shin'ichi Saito Abstract The ECT2 protooncogene plays a critical role in cytokinesis, and its C-terminal half encodes a Dbl homology-pleckstrin homology module, which catalyzes guanine nucleotide exchange on the Rho family of small GTPases. The N-terminal half of ECT2 (ECT2-N) contains domains related to the cell cycle regulator/checkpoint control proteins including human XRCC1, budding yeast CLB6, and fission yeast Cut5. The Cut5-related domain consists of two BRCT repeats, which are widespread to repair/checkpoint control proteins. ECT2 is ubiquitously expressed in various tissues and cell lines, but elevated levels of ECT2 expression were found in various tumor cell lines and rapidly developing tissues in mouse embryos. Consistent with these findings, induction of ECT2 expression was observed upon stimulation by serum or various growth factors. In contrast to other oncogenes whose expression is induced early in G1, ECT2 expression was induced later, coinciding with the initiation of DNA synthesis. To test the role of the cell cycle regulator/checkpoint control protein-related domains of ECT2 in cytokinesis, we expressed various ECT2 derivatives in U2OS cells, and analyzed their DNA content by flow cytometry. Expression of the N-terminal half of ECT2, which lacks the catalytic domain, generated cells with more than 4N DNA content, suggesting that cytokinesis was inhibited in these cells. Interestingly, ECT2-N lacking the nuclear localization signals inhibited cytokinesis more strongly than the derivatives containing these signals. Mutational analyses revealed that the XRCC1, CLB6, and BRCT domains in ECT2-N are all essential for the cytokinesis inhibition by ECT2-N. These results suggest that the XRCC1, CLB6, and BRCT domains of ECT2 play a critical role in regulating cytokinesis. Published 2003 Wiley-Liss, Inc. [source] Differential expression of human Polycomb group proteins in various tissues and cell typesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue S36 2001Marco J. Gunster Abstract Polycomb group proteins are involved in the maintenance of cellular identity. As multimeric complexes they repress cell type-specific sets of target genes. One model predicts that the composition of Polycomb group complexes determines the specificity for their target genes. To study this hypothesis, we analyzed the expression of Polycomb group genes in various human tissues using Northern blotting and immunohistochemistry. We found that Polycomb group expression varies greatly among tissues and even among specific cell types within a particular tissue. Variations in mRNA expression ranged from expression of all analyzed Polycomb group genes in the heart and testis to no detectable Polycomb group expression at all in bone marrow. Furthermore, each Polycomb group gene was expressed in a different number of tissues. RING1 was expressed in practically all tissues, while HPH1 was expressed in only a few tissues. Also within one tissue the level of Polycomb group expression varied greatly. Cell type-specific Polycomb group expression patterns were observed in thyroid, pancreas, and kidney. Finally, in various developmental stages of fetal kidney, different Polycomb group expression patterns were observed. We conclude that Polycomb group expression can vary depending on the tissue, cell type, and development stage. Polycomb group complexes can only be composed of the Polycomb group proteins that are expressed. This implies that with cell type-specific Polycomb group expression patterns, cell type-specific Polycomb group complexes exist. The fact that there are cell type-specific Polycomb group targets and cell type-specific Polycomb group complexes fits well with the hypothesis that the composition of Polycomb group complexes may determine their target specificity. J. Cell. Biochem. Suppl. 36: 129,143, 2001. © 2001 Wiley-Liss, Inc. [source] Na+/Mg2+ exchange is functionally coupled to the insulin receptor,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2004Ana Ferreira Regulation of cellular Mg2+ levels by insulin has been shown in various tissues. However, the mechanisms for hormonal regulation of cellular Mg2+ have not been well described. We studied the effect of insulin on Na+/Mg2+ exchange in normal human cells, measuring Na+/Mg2+ exchange activity as net total Mg2+ efflux driven by an inward Na+ gradient in Mg2+ -loaded red blood cells (RBCs). Na+/Mg2+ exchange was increased significantly by the addition of 2.4 nmol/L of insulin to the flux medium (from 0.60,±,0.06 mmol/L cell,×,h to 0.75,±,0.08 mmol/L cell,×,h [P,=,0.0098, n,=,44]). A dose-response curve for the effects of insulin on the exchanger activity gave an estimated EC50 for insulin of 0.95,±,0.31 nmol/L and a Vmax of 0.86,±,0.12 mmol/L cell,×,h (n,=,7). Kinetics of the Na+/Mg2+ exchange were characterized by measuring its activity as a function of Mg2+ and Na+ concentrations. The K0.5 for cellular Mg2+ was not affected by incubation with insulin. However, the K0.5 for extracellular Na+ decreased from 69.9,±,6.3 to 40.3,±,8.4 mol/L (n,=,5, P,=,0.03) in the presence of insulin. We also studied the effect of wortmannin (WT), a PI 3-kinase inhibitor, on activity of the exchanger. WT significantly blocked the insulin-stimulated Na+/Mg2+ activity (n,=,6, P,=,0.048), with an IC50 of 0.5 nmol/L. LY294002, another PI 3-kinase inhibitor, likewise blocked the insulin-stimulated activity of the exchanger. Therefore, insulin regulates cellular Mg2+ metabolism in part via an increase in the affinity for Na+ of the Na+/Mg2+ exchange and PI 3-kinase activation, suggesting another role for the PI 3-kinase pathway in insulin-mediated cellular events. © 2003 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||