PURPOSE: Evidence exists that dysregulation of apoptosis is involved in the pathogenesis of cancer development. Fas- associated death domain (FADD) protein, an adaptor protein of death receptors, is a critical regulatory component of the extrinsic cell- death pathway that exerts its pro-apoptotic effect upon binding with death receptors. Expression of the FADD protein has not been reported in stomach cancer. The aim of this study was to explore the expression status of the FADD protein in stomach cancers. MATERIALS AND METHODS: In the current study, we analyzed the expression of the FADD protein in 60 advanced stomach cancer by using immunohistochemistry and a tissue microarray approach. RESULTS: Immunopositivity (defined as > or =30%) was observed for the FADD protein in 23 (38%) of the 60 cancers. Normal gastric mucosal cells showed expression of the FADD protein. CONCLUSION: Taken together, these results indicate that decreased expression of the FADD protein is a frequent event in stomach cancers and suggest that to avoid apoptosis, stomach cancer cells in vivo may need loss of FADD expression, which might contribute to tumor development.
Apoptosis ; Fas-Associated Death Domain Protein* ; Immunohistochemistry ; Receptors, Death Domain ; Stomach Neoplasms* ; Stomach*

In this research, we studied the formation of Drosophila melanogaster FADD (Fas-associated death domain-containing protein) amyloid fiber and its influence on signal transduction in IMD (Immune deficiency) signaling pathway to better understand the regulation mechanism of Drosophila innate immune signaling pathway, which will provide reference for the immune regulation in other species. First, we purified dFADD protein expressed in Escherichia coli and performed Sulfur flavin T binding and transmission electron microscopy to identify the dFADD amyloid fibers formed in vitro. Then we investigated the formation of dFADD polymers in S2 cells using SDD-AGE and confocal microscope. We also constructed dFADD mutants to find out which domain is essential to fiber formation and its effect on IMD signal transduction. Our results revealed that dFADD could be polymerized to form amyloid fiber polymers in vitro and inside the cells. Formation of fibers relies on DED (Death-effector domain) domain of dFADD, since DED domain-deleted mutant existed as a monomer. Dual luciferase reporter assay showed that intact DED domain was required for the induction of downstream antimicrobial peptides, indicating that fiber formation was the key to IMD signal transduction. Our study revealed the role of dFADD in mediating the cascade between IMD and Dredd in the IMD signaling pathway by forming amyloid fibers, suggesting an evolutionarily conserved regulatory mechanism of innate immune signaling pathway.
Animals ; Drosophila Proteins ; biosynthesis ; immunology ; Drosophila melanogaster ; immunology ; Fas-Associated Death Domain Protein ; biosynthesis ; immunology ; Immunity, Innate ; immunology ; Signal Transduction

OBJECTIVETo investigate the changes in the expressions of Fas-associated death domain protein (FADD) and cellular-FLICE inhibitory protein (c-FLIP) in the articular cartilage of patients with Kashin-Beck disease (KBD) and the role of these proteins in the pathogenesis of KBD.

METHODSThe cartilage samples were collected from patients with established diagnosis of KBD and osteoarthritis and from healthy control subjects undergoing amputation due to traffic accidents. The expressions of Fas-associated death domain protein (FADD) and cellular-FLICE inhibitory protein (c-FLIP) in the cartilage were detected by immunohistochemistry, and the positive chondrocytes were counted in different layers of the articular cartilage under microscope.

RESULTSThe positivity rates of FADD in the middle layer of articular cartilage from patients with KBD [(28.68∓2.19)%] and osteoarthritis [(35.40∓2.34)%] were significantly higher than that in normal cartilage [(10.51∓5.02)%, F=16.245, P=0.000], but the rates in the upper and deeper layers were comparable among the 3 groups (P=0.206-0.761). In KBD cartilage, FADD expression was the highest in the middle layer [(28.68∓5.38)%] followed by the deeper layer [(17.94∓8.38)%]. Compared with the healthy controls, KBD and osteoarthritis patients showed significantly higher FLIP expression in the upper layer of the cartilage (F=5.929, P=0.018) but similar expressions in middle and deeper layers.

CONCLUSIONSKBD patients have significant increased FADD expression in the middle layer but decreased FLIP expression in the upper layer of the cartilage, suggesting that the death receptor pathway and its regulators play important roles in the pathogenesis of KBD.

CASP8 and FADD-Like Apoptosis Regulating Protein ; metabolism ; Cartilage, Articular ; metabolism ; pathology ; Case-Control Studies ; Fas-Associated Death Domain Protein ; metabolism ; Humans ; Immunohistochemistry ; Kashin-Beck Disease ; metabolism ; pathology

OBJECTIVETo investigate the role of Fas pathway in H(2)O(2)-induced apoptosis of L02 human hepatocytes and the effect of schisandrin B on Fas pathway.

METHODSReal-time quantitative PCR was used to detect the expressions of FAS, fas associated death domain protein (FADD) and caspase-8 mRNA in L02 cells exposed to H(2)O(2). Flow cytometry was employed to assess the cell apoptosis. ELISA, Western blotting and spectrophotometric assay were performed to determine the expressions of FAS protein, FADD protein and caspase-8 activity.

RESULTSWithin the dose range of 5-15 mol/L, schisandrin B dose-dependently inhibited FAS and FADD expressions and caspase-8 activation.

CONCLUSIONSchisandrin B can partially inhibit H(2)O(2)-induced L02 cell apoptosis possibly by affecting the FAS-FADD-caspase-8 pathway.

Apoptosis ; drug effects ; Caspase 8 ; metabolism ; Cell Line ; Cyclooctanes ; pharmacology ; Fas-Associated Death Domain Protein ; metabolism ; Flow Cytometry ; Hepatocytes ; drug effects ; metabolism ; Humans ; Hydrogen Peroxide ; adverse effects ; Lignans ; pharmacology ; Polycyclic Compounds ; pharmacology ; Signal Transduction ; fas Receptor ; metabolism

OBJECTIVETo investigate the mRNA expressions of the TNF adapter proteins, including TNF receptor-associated death domain protein (TRADD), Fas-associated death domain protein (FADD), receptor-interacting protein 1 (RIP-1) and TNF receptor-associated factor-2 (TRAF-2) in peripheral blood mononuclear cells (PBMCs) of lupus nephritis (LN) patients of various TCM asthenia syndromes. Methods Fifty-one inpatients with LN were differentiated according to TCM syndrome differentiation, 13 cases of yin-deficiency with inner heat syndrome (A); 26 cases of both qi-yin deficiency syndrome (B), 12 cases of Pi-Shen yang-deficiency syndrome (C). Peripheral venous blood samples from the 51 LN patients and 17 healthy subjects were collected to separate PBMCs. The mRNA expressions of TNF adapter molecules (TRADD, FADD, RIP-1 and TRAF-2), as well as Caspase-3 and interleukin-1beta (IL-1beta) were analyzed by quantitative real-time PCR and the differences among them were compared.

RESULTS(1) As compared with the healthy subjects, expression of TRADD mRNA in patients of syndrome A, B and C was lowered to 0.54, 0.32, and 0.38-fold, respectively (P < 0.05, P < 0.01), showing insignificant difference among the three syndromes; (2) FADD mRNA lowered to 0.79, 0.62, and 0.72-fold respectively, only with significance shown in syndrome B (P < 0.05); (3) RIP-1 mRNA lowered to 0.79, 0.50, and 0.60-fold respectively with significance shown in syndrome B and C (P < 0.01, P < 0.05), and insignificant difference was shown among the three syndromes; (4) TRAF-2 lowered to 0.70, 0.52, and 0.50-fold respectively (P < 0.01, P < 0.01, P = 0.07), significance shown in syndrome B and C (P < 0.01), but with insignificant difference among the three; (5) Caspase-3 elevated in all patients of the three syndromes (all P < 0.01); (6) IL-1beta in syndrome A was apparently lower ed to the normal range and also lower than that in the other two syndromes (both P < 0.05).

CONCLUSIONSExpressions of TRADD, FADD, RIP-1 and TRAF-2 mRNA decreased in all the patients of various TCM asthenia syndromes, the decrement in patients of syndrome B and C was lesser than that in syndrome A. These abnormal low expressions of signal proteins might be the substantial bases for asthenia syndromes of LN patients, and the apoptotic signal mediated by them may involve in the formation of asthenia syndrome in LN.

Adaptor Proteins, Signal Transducing ; genetics ; metabolism ; Adolescent ; Adult ; Case-Control Studies ; Child ; Fas-Associated Death Domain Protein ; genetics ; metabolism ; Female ; Humans ; Leukocytes, Mononuclear ; metabolism ; Lupus Nephritis ; blood ; Male ; Medicine, Chinese Traditional ; Middle Aged ; RNA, Messenger ; genetics ; metabolism ; Receptor-Interacting Protein Serine-Threonine Kinases ; genetics ; metabolism ; TNF Receptor-Associated Death Domain Protein ; genetics ; metabolism ; TNF Receptor-Associated Factor 2 ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; blood ; metabolism ; Yang Deficiency ; blood ; Yin Deficiency ; blood ; Young Adult

Fas-associated death domain (FADD) is a signal connection protein in Fas/FasL apoptotic path which might play a key role on apoptosis by transferring apoptotic signal. To reveal the intracellular signal transduction molecules involved in the procedure of follicular development in bovine ovary, we cloned FADD gene in bovine ovary tissue with RT-PCR, deleted the termination codon in its cDNA and directionally cloned the amplified FADD gene into eukaryotic expression vector pAcGFP-N1 including AcGFP, successfully constructed the fusion protein recombinant plasmid. After identifying by restrictive enzyme Bgl II/EcoR I and sequencing, transfected pAcGFP-bFADD into CHO-K1 cell mediated by Lipofectamine 2000, observed the expression of AcGFP and detected the transcription and expression of FADD by RT-PCR and Western blotting. The results showed that the cattle FADD was successfully cloned, the pAcGFP-bFADD fusion protein recombinant plasmid was successfully constructed by introducing Bgl II, EcoR I cloning site at two ends of FADD open reading frame and inserting a Kozak sequence before start codon. AcGFP expression was detected as early as 24 h after transfection. The percentage of AcGFP positive cells reached about 65% after 24 h. A 654 bp transcription was amplified by RT-PCR, and 51.4 kD target protein was detected by Western blotting. Construction of pAcGFP-bFADD recombinant plasmid should be helpful for further understanding the mechanism of regulation of FADD on bovine oocytes formation and development.
Animals ; Base Sequence ; CHO Cells ; Cattle ; Cloning, Molecular ; Cricetinae ; Cricetulus ; DNA, Complementary ; genetics ; Fas-Associated Death Domain Protein ; biosynthesis ; genetics ; Female ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Molecular Sequence Data ; Oocytes ; cytology ; Open Reading Frames ; Ovary ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Transfection

We have recently reported that Ginsenoside Rh2 (G-Rh2) induces the activation of two initiator caspases, caspase-8 and caspase-9 in human cancer cells. However, the molecular mechanism of its death-inducing function remains unclear. Here we show that G-Rh2 stimulated the activation of both caspase-8 and caspase-9 simultaneously in HeLa cells. Under G-Rh2 treatment, membrane death receptors Fas and TNFR1 are remarkably upregulated. However, the induced expression of Fas but not TNFR1 was contributed to the apoptosis process. Moreover, significant increases in Fas expression and caspase-8 activity temporally coincided with an increase in p53 expression in p53-non-mutated HeLa and SK-HEP-1 cells upon G-Rh2 treatment. In contrast, Fas expression and caspase-8 activity remained constant with G-Rh2 treatment in p53-mutated SW480 and PC-3 cells. In addition, siRNA-mediated knockdown of p53 diminished G-Rh2-induced Fas expression and caspase-8 activation. These results indicated that G-Rh2-triggered extrinsic apoptosis relies on p53-mediated Fas over-expression. In the intrinsic apoptotic pathway, G-Rh2 induced strong and immediate translocation of cytosolic BAK and BAX to the mitochondria, mitochondrial cytochrome c release, and subsequent caspase-9 activation both in HeLa and in SW480 cells. p53-mediated Fas expression and subsequent downstream caspase-8 activation as well as p53-independent caspase-9 activation all contribute to the activation of the downstream effector caspase-3/-7, leading to tumor cell death. Taken together, we suggest that G-Rh2 induces cancer cell apoptosis in a multi-path manner and is therefore a promising candidate for anti-tumor drug development.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cytochromes c ; metabolism ; Enzyme Activation ; drug effects ; Ginsenosides ; chemistry ; pharmacology ; HeLa Cells ; Humans ; Inhibitory Concentration 50 ; Mitochondria ; drug effects ; metabolism ; Protein Transport ; drug effects ; Receptors, Death Domain ; metabolism ; Receptors, Tumor Necrosis Factor, Type I ; metabolism ; Signal Transduction ; drug effects ; Tumor Suppressor Protein p53 ; metabolism ; Up-Regulation ; drug effects ; bcl-2 Homologous Antagonist-Killer Protein ; metabolism ; bcl-2-Associated X Protein ; metabolism ; fas Receptor ; metabolism