Rafts, cholesterol- and sphingolipid-rich membrane microdomains, have been shown to play an important role in immune cell activation. More recently rafts were implicated in the signal transduction by members of the TNF receptor (TNFR) family. In this study, we provide evidences that the raft microdomain has a crucial role in RANK (receptor activator of NF-kappaB) signaling. We found that the majority of the ectopically expressed RANK and substantial portion of endogenous TRAF2 and TRAF6 were detected in the low-density raft fractions. In addition, TRAF6 association with rafts was increased by RANKL stimulation. The disruption of rafts blocked the TRAF6 translocation by RANK ligand and impeded the interaction between RANK and TRAF6. Our observations demonstrate that proper RANK signaling requires the function of raft membrane microdomains.
Carrier Proteins/metabolism ; Glycoproteins/*metabolism ; Human ; Membrane Glycoproteins/metabolism ; Membrane Microdomains/*metabolism ; Protein Transport/physiology ; Proteins/*metabolism ; Receptors, Cytoplasmic and Nuclear/*metabolism

Acute-Phase Proteins ; physiology ; Carrier Proteins ; physiology ; Humans ; Membrane Glycoproteins ; physiology ; Receptors, Cell Surface ; physiology ; Receptors, Immunologic ; physiology ; Receptors, Scavenger ; Sepsis ; metabolism ; physiopathology ; Signal Transduction ; Toll-Like Receptors

OBJECTIVETo investigate the distribution, changes and a possible role for retinal dopamine transporter (DAT) in experimental myopia in chickens.

METHODSTwo-day-old chickens were divided into four groups. Chicken eyes were fitted with lenses of -10D,-20D and translucent goggles unilaterally. Normal eyes were used as controls. After 3 wk, all chickens were given an intramuscular injection of (125)I-beta-CIT 2beta-carbomethoxy-3beta-(4-iodophenyl)tropane and sacrificed two hours post injection. Retinal pigment epithelium (RPE) and the neural retina were obtained together or RPE was dissected out from the neural retina. Radioactive DAT from each specimen was assayed by gamma-counter.

RESULTSRetinal DAT was detected in RPE specimens rather than in the neural retina in all eyes. Radioactive DAT in myopic eyes was higher, compared with control eyes.

CONCLUSIONSRetinal DAT is mainly located in the RPE and may be involved in the formation of lens induced myopia (LIM) and form deprivation myopia (FDM). These methods may provide a new approach for further studying the role of the dopamine system in experimental myopia.

Animals ; Chickens ; Dopamine Plasma Membrane Transport Proteins ; Eye ; growth & development ; Membrane Glycoproteins ; Membrane Transport Proteins ; analysis ; physiology ; Myopia ; metabolism ; Nerve Tissue Proteins ; Retina ; chemistry

Cysteine-rich secretory protein-1 (CRISP-1) is a glycoprotein secreted by the epididymal epithelium. It is a member of a large family of proteins characterized by two conserved domains and a set of 16 conserved cysteine residues. In mammals, CRISP-1 inhibits sperm-egg fusion and can suppress sperm capacitation. The molecular mechanism of action of the mammalian CRISP proteins remains unknown, but certain non-mammalian CRISP proteins can block ion channels. In the rat, CRISP-1 comprises two forms referred to as Proteins D and E. Recent work in our laboratory demonstrates that the D form of CRISP-1 associates transiently with the sperm surface, whereas the E form binds tightly. When the spermatozoa are washed, the E form of CRISP-1 persists on the sperm surface after all D form has dissociated. Cross-linking studies demonstrate different protein-protein interaction patterns for D and E, although no binding partners for either protein have yet been identified. Mass spectrometric analyses revealed a potential post-translational modification on the E form that is not present on the D form. This is the only discernable difference between Proteins D and E, and presumably is responsible for the difference in behavior of these two forms of rat CRISP-1. These studies demonstrate that the more abundant D form interacts with spermatozoa transiently, possibly with a specific receptor on the sperm surface, consistent with a capacitation-suppressing function during sperm transit and storage in the epididymis, and also confirm a tightly bound population of the E form that could act in the female reproductive tract.
Amino Acid Sequence ; Animals ; Conserved Sequence ; Humans ; Male ; Mammals ; Membrane Glycoproteins ; genetics ; metabolism ; Molecular Sequence Data ; Rats ; Spermatozoa ; physiology

Apoptosis is responsible for the loss of thyrocytes in autoimmune thyroiditis. Recent investigations into the pathogenesis of apoptosis have revealed that the important roles of suicide molecules expression on both thyrocytes and cytotoxic T-lymphocytes. To study the mechanism of thyrocyte loss in various forms of thyroiditis, we evaluated in situ expression patterns of CD40, Fas, and Fas-L on thyrocytes and infiltrating inflammatory cells by immunohistochemical staining of thyroid samples obtained from 49 patients (Graves' disease, n=10 : Hashimoto's thyroiditis, n=14; nonspecific lymphocytic thyroiditis, n=11; subacute granulomatous thyroiditis, n=11; normal, n=3). The role of cytotoxic T-lymphocytes was also evaluated by analyzing the expression of granzyme B along with their phenotypic characteristics. CD40 was not expressed on thyrocytes of normal controls while they showed a diffuse expression of Fas and a scattered focal expression of Fas-L. The plump thyrocytes proximal to the inflammatory infiltrates showed more intense expressions of these three molecules in various forms of thyroiditis and a close correlation was found between CD40 and Fas-L expression on thyrocytes. Unlike Fas, which was expressed on infiltrating lymphocytes in all groups, Fas-L was not expressed on infiltrating lymphocytes, except those in subacute granulomatous thyroiditis. Granzyme B expressing activated cytotoxic T-lymphocytes occupied a negligible proportion of CD8+ T-lymphocytes in various forms of thyroiditis, and no difference was found in terms of their proportions according to the type of thyroiditis. These results show the acquisition of CD40, Fas and Fas-L molecules on thyrocytes proximal to inflammatory cell aggregates and the negligible expression of granzyme B and Fas-L on the infiltrating lymphocytes, and suggest that Fas and Fas-L mediated apoptosis of thyrocytes (fratricide) may be more important than T cell-mediated cytotoxicity in various forms of thyroiditis.
Antigens, CD40/*metabolism ; Antigens, CD95/metabolism ; Apoptosis/*physiology ; Graves' Disease/*metabolism/pathology ; Human ; Membrane Glycoproteins/metabolism ; Reference Values ; Thyroiditis, Autoimmune/*metabolism/pathology

Platelet glycoprotein VI (GPVI) is a major receptor for collagen on the platelet surface. It mediates the initial platelet contact with collagen, generates intracellular signals, increases the affinity of integrin receptor, and causes platelet aggregation and thrombosis. Suppression of GPVI function can significantly inhibit collagen-induced platelet adhesion, aggregation and thrombosis, so GPVI has become a novel target for antiplatelet therapy. Within the last few years, major advances have been made in understanding platelet-collagen interactions. In this paper, the advances of study on GPVI, including composition of GPVI, functions of GPVI, factors related with functions of GPVI, GPVI and clinic were summarized.
Humans ; Platelet Adhesiveness ; physiology ; Platelet Aggregation ; physiology ; Platelet Glycoprotein GPIIb-IIIa Complex ; metabolism ; physiology ; Platelet Glycoprotein GPIb-IX Complex ; metabolism ; physiology ; Platelet Membrane Glycoproteins ; chemistry ; metabolism ; physiology ; Protein Binding ; physiology

Animals ; Drosophila Proteins ; Humans ; Lipopolysaccharides ; pharmacology ; Membrane Glycoproteins ; metabolism ; physiology ; Receptors, Cell Surface ; metabolism ; physiology ; Signal Transduction ; Toll-Like Receptor 4 ; Toll-Like Receptors

OBJECTIVETo study the significance of Fas and Fas-L expression in adenocarcinoma of uterine cervix.

METHODSBoth carcinoma tissue and their surrounding tissues from 36 patients with adenocarcinoma of uterine cervix, previously untreated either by radiation or chemotherapy, were studied for the expression of Fas and Fas-L by immunohistochemical stain with DNA apoptosis fragment detected by TUNEL.

RESULTSThe TUNEL labeling index was negatively correlated with differentiation of adenocarcinoma of cervix. Compared to highly differentiated and moderately differentiated tumor, the TUNEL labeling index was reduced obviously in poorly differentiated adenocarcinoma (P < 0.01). Fas expression was detected in 31 cases (86%) while there were only 3 weakly stained in the normal endocervical glands around the carcinoma. The 5 unstained carcinomas were 3 highly differentiated and 2 moderately differentiated. The positively stained Fas was associated with differentiation; the stronger the stain, the less differentiation there was. The Fas-L expression was detected in all adenocarcinomas while there was only 1 weakly stained in the normal ones. No significant difference was found in the expression of Fas-L in carcinomas with different degrees of differentiation. No correlation was observed between Fas and Fas-L expression.

CONCLUSIONSThe Fas expression is positively correlated with the different degrees of differentiation and Fas-L expression may be associated with the escape from of immunal surveillance.

Adenocarcinoma ; diagnosis ; metabolism ; Apoptosis ; physiology ; Biomarkers, Tumor ; biosynthesis ; Cell Differentiation ; physiology ; Fas Ligand Protein ; Female ; Humans ; Immunohistochemistry ; Membrane Glycoproteins ; biosynthesis ; Uterine Cervical Neoplasms ; diagnosis ; metabolism ; fas Receptor ; biosynthesis

OBJECTIVETo explore the molecular mechanism of the differences in biofilm formation abilities of Candida albicans isolated from the respiratory tract.

METHODSThe biofilms formed by Candida albicans isolates from the respiratory tract and the standard strain ATCC90028 were examined for bacterial proliferation using XTT reduction assay. The mRNA expression of CPH1, EFG1, ALS3 and HWP1 in the isolates were measured with fluorescent quantitative RT-PCR.

RESULTSXTT reduction assay demonstrated a strong ability of biofilm formation in 8 clinical isolates, and a relatively low biofilm formation ability in 7 clinical isolates and ATCC90028 strain. The strong and weak biofilm formers showed significant differences in ALS3 and HWP1 mRNA expressions (P<0.05) but not in EFG1 or CPH1 mRNA expressions (P>0.05).

CONCLUSIONThe clinical isolates from the respiratory tract have different biofilm formation abilities under regulation by genes other than the transcription factors CPH1 and EFG1.

Biofilms ; Candida albicans ; classification ; genetics ; physiology ; DNA-Binding Proteins ; metabolism ; Exons ; Fungal Proteins ; metabolism ; Humans ; Membrane Glycoproteins ; metabolism ; Phenotype ; Respiratory System ; microbiology ; Transcription Factors ; metabolism

Cytokines ; physiology ; Fas Ligand Protein ; Fatty Liver ; etiology ; metabolism ; Humans ; Ion Channels ; Lipid Peroxidation ; Membrane Glycoproteins ; physiology ; Membrane Transport Proteins ; Mitochondria ; metabolism ; Mitochondrial Proteins ; Proteins ; physiology ; Reactive Oxygen Species ; Uncoupling Protein 2