ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370482

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

Extracellular matrix molecules help regulate many aspects of neural development, including survival, migration, axon growth, and synapse formation by neurons. These same molecules have been shown to modulate regeneration of neurons after injuries. They also regulate the development and differentiation of other neural cells, such as astroglia and Schwann cells. Significant progress has been made recently in characterizing both ECM constituents and their receptors in the nervous system. Extracellular matrix molecules promote cell adhesion, activate intracellular signaling pathways, and modulate the activities of several growth factors and proteins. Our current understanding of the extracellular matrix, its receptors, and its functions in the nervous system are discussed.—Venstrom, K. A., Reichardt, L. F. Role of extracellular matrix molecules and their receptors in the nervous system.FASEB J. 7:996‐1003; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370483

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

The human organism survives the constant attack by bacteria and other pathogens thanks to the surveillance function of the neutrophil leukocytes. At sites of infection, several messenger molecules are generated that attract neutrophils from the blood and direct their migration toward the microbes, a process termed chemotaxis. Neutrophils sense chemotactic agonists through a group of closely related, GTP‐binding protein‐coupled receptors. Several of these have been recently cloned and shown to belong to the superfamily of rhodopsin‐like, seven‐transmembrane‐domain receptors. At the site of infection, the neutrophils engulf and kill the invading microbes. This critical function depends on the production of superoxide and related radicals by a tightly regulated, membrane‐bound NADPH oxidase that is activated by chemotactic agonists and other inflammatory stimuli. The characteristics of the receptors as well as new insights into the mechanism of activation of the superoxide‐forming oxidase as presented at a recent FASEB meeting symposium are reviewed.—Baggiolini, M., Boulay, F., Badwey, J. A., Curnutte, J. T. Activation of neutrophil leukocytes: chemoattractant receptors and respiratory burst.FASEB J. 7:1004‐1010; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8396540

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

In this review the phenomenon of anti‐bacterial activity of phagocytes and its relationship to the general system of signal transduction in eukaryotic cells is examined. Data are reviewed that support the hypothesis that interference in transduction of regulatory signals during microbial invasion could be caused by specific bacterial products and lead to an inadequate bactericidal response, and hence multiplication of the bacteria in a host. In this connection, information concerning virulence factors of the facultative intracellular parasiteLegionellais discussed.—Belyi, Y. F. intracellular parasitism ofLegionellaand signaling in eukaryotic cells.FASEB J. 7:1011‐1015; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370469

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

Significant advances have been made in the characterization of luciferases and otherlux‐specific proteins as well as theluxgenes from a number of different species of marine and terrestrial luminescent bacteria. A commonluxgene organization (luxCDAB..E) modulated by the presence of specific genes involved in regulation and flavin binding and metabolism (luxF‐I,L,R,Y) has been found with the luciferase genes (luxAB) flanked by the genes involved in synthesis of its fatty aldehyde substrate (luxCDE). For many species, light intensity per cell is highly dependent on cellular growth resulting in a spectacular autoinduction of luminescence at high cell density. Consequently, the bacterialluxsystem is of particular interest as it can serve as an excellent model for more general signal transduction systems involved in developmental processes, intercellular communication, and even symbioses. Identification of theluxautoinducers and regulatory proteins ofVibrio harveyiandVibrio fischerihas provided the biochemical and genetic basis for dissection of the luminescent system. Isolation of theluxgenes and the ability to transfer these genes into prokaryotic and eukaryotic organisms have greatly expanded the scope and potential uses of bacterial bioluminescence as a safe, rapid, and sensitive sensor for a wide variety of compounds and metabolic processes.—Meighen, E. A. Bacterial bioluminescence: organization, regulation, and application of theluxgenes.FASEB J. 7:1016‐1022; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370470

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

Heparan sulfate is a regulatory polysaccharide. It modulates specific growth factor‐receptor interactions, accelerates the formation of specific proteinase‐proteinase inhibitor complexes, and mediates interactions of the cell surface with several enzymes and structural proteins. It abounds on the surfaces of embryonic cells, respecting or outlining morphogenetic rather than histological boundaries. This cell surface‐associated heparan sulfate is implanted on specific integral membrane proteins, which together constitute two novel molecular families. The first family includes four syndecan‐like integral membrane proteoglycans (SLIPS), with core proteins that span the membrane and shared sequence motifs in highly conserved cytoplasmic domains. The second is made up by two or more glypican‐related integral membrane proteoglycans (GRIPS) that are linked to the cell surface via glycosyl phosphatidylinositol. These proteoglycans show differential expression and turnover patterns, prevailing in distinct cell types, membrane domains, and endocytotic machineries, and are subject to strict developmental controls. This suggests that each of these cell surface proteoglycans functions in a specific context, and that these functions pertain to the transduction of signals that emanate from the continuous interplay between matrix components, growth factors, and proteinases. Caution: beware of loose GRIPS and SLIPS on unsteady cell surfaces.—David, G. Integral membrane heparan sulfate proteoglycans.FASEB J. 7:1023‐1030; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370471

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

Endothelial cells are the primary physical barrier between blood and tissue in microvessels. The other capillary and post‐capillary venule wall cell is the pericyte. The literature on the biology of endothelium is appreciable but less is known about pericytes. Pericytes are morphologically, biochemically, and physiologically heterogeneous. Some of pericyte functional characteristics observed in vivo and in vitro are that they: regulate endothelial proliferation and differentiation; contract in manners that either exacerbate or stem endothelial cell functional inflammatory leakage; function as a progenitor cell; synthesize and secrete a wide variety of vasoactive autoregulating agonists; synthesize and release structural constituents of the basement membrane and extracellular matrix. Pericytes are also involved in specific microvascular diseases. This review focuses principally on nonmesangial pericytes and specific activities such as the posttranslational, short‐term responses that affect microvascular perfusion and permeability, and on pericyte‐endothelial cell interaction.—Shepro, D., Morel, N. M. L. Pericyte physiology.FASEB J. 7:1031‐1038; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370472

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

Long‐chain carnitine acyltransferases are a family of enzymes found in mitochondria, peroxisomes, and endoplasmic reticulum that catalyze the exchange of carnitine for coenzyme A in the fatty acyl‐CoA. Conversion of the fatty acyl‐CoA to fatty acylcarnitine renders the fatty acid more permeable to the various cellular membranes. The mitochondrial carnitine palmitoyltransferases are considered important in the regulation of mitochondrial β‐oxidation of long‐chain fatty acids, However, palmitoylcarnitine produced by peroxisomal carnitine octanoyltransferase or by microsomal carnitine palmitoyltransferase is not different from that produced by the mitochondrial enzyme. Therefore, for there to be control of fatty acid oxidation by the long‐chain carnitine acyltransferases, there would have to be some mechanism to coordinately regulate these varied enzymes. The first system of regulation involves inhibition by malonyl‐CoA, an intermediate in the synthesis of fatty acids. Malonyl‐CoA inhibits long‐chain carnitine acyltransferase activity by all three enzymes at similar concentrations in the physiological range. In addition, the mitochondrial and peroxisomal enzymes are known to be regulated at the level of mRNA transcription by a number of shared factors. Although the microsomal enzyme is less well studied, there does, indeed, appear to be a pattern of coordinate regulation for this system.—Brady, P. L., Ramsay, R. R., Brady, L. J. Regulation of the long‐chain carnitine acyltransferases,FASEB J. 7:1039‐1044; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370473

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

Recent evidence indicates that cell death through apoptosis may be an important mechanism to prevent tumor development. Therefore, agents that inhibit apoptosis may function as tumor promotors. The purpose of this study was to determine the effects of nicotine on the process of apoptosis. The results demonstrate that nicotine inhibits apoptosis induced by diverse stimuli including tumor necrosis factor (TNF), UV light, chemotherapeutic drugs, and calcium ionophore. This phenomenon was observed in normal and transformed cells derived from a variety of species and tissues, including tumor cell types related to tobacco use. The major nicotine metabolite, cotinine, also inhibited apoptosis, whereas N‐nitrosodiethylamine, a carcinogen found in tobacco, was without effect. Therefore, nicotine‐mediated inhibition of apoptosis may contribute to the pathogenesis of tobacco‐related cancer as well as decrease the efficacy of cancer therapies.—Wright, S. C., Zhong, J., Zheng, H., Larrick, J. W. Nicotine inhibition of apoptosis suggests a role in tumor production,FASEB J.7: 1045‐1051; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370474

出版商:Wiley    

年代:1993

数据来源: WILEY

摘要:

Data collected over a period of 4 years show that melatonin (two daily i.v. injections of 0.1 mg/kg body wt. given at 16:00 h) was able to enhance antibody‐dependent cellular cytotoxicity (ADCC) in summer, but not in winter. Dose‐response curves carried out in January, May, July, and October suggest that the seasonal effects reported are related to differences in the sensitivity of mice to melatonin during the course of the year. These results show seasonal variations in the immune modulatory action of melatonin.—Giordano, M., Vermeulen, M., Palermo, M. S. Seasonal variations in antibody‐dependent cellular cytotoxicity regulation of melatonin.FASEB J. 7:1052‐1054; 1993.

ISSN:0892-6638    

DOI:10.1096/fasebj.7.11.8370475

出版商:Wiley    

年代:1993

数据来源: WILEY