Alzheimer's disease(AD) patients in China have been surging, and the resultant medical burden and care demand have a huge impact on the development of individuals, families, and the society. The active component compound of Epimedii Folium, Astragali Radix, and Puerariae Lobatae Radix(YHG) can regulate the expression of iron metabolism-related proteins to inhibit brain iron overload and relieve hypofunction of central nervous system in AD patients. Hepcidin is an important target regulating iron metabolism. This study investigated the effect of YHG on the expression of a disintegrin and metalloprotease-17(ADAM17), a key enzyme in the hydrolysis of β amyloid precursor protein(APP) in HT22 cells, by mediating hepcidin. To be specific, HT22 cells were cultured in vitro, followed by liposome-mediated siRNA transfection to silence the expression of hepcidin. Real-time PCR and Western blot were performed to examine the silencing result and the effect of YHG on hepcidin in AD cell model. HT22 cells were randomized into 7 groups: control group, Aβ25-35 induction(Aβ) group, hepcidin-siRNA(siRNA) group, Aβ25-35 + hepcidin-siRNA(Aβ + siRNA) group, Aβ25-35+YHG(Aβ+YHG) group, hepcidin-siRNA+YHG(siRNA+YHG) group, Aβ25-35+hepcidin-siRNA+YHG(Aβ+siRNA+YHG) group. The expression of ADAM17 mRNA in cells was detected by real-time PCR, and the expression of ADAM17 protein by immunofluorescence and Western blot. Immunofluorescence showed that the ADAM17 protein expression was lower in the Aβ group, siRNA group, and Aβ+siRNA group than in the control group(P<0.05) and the expression was lower in the Aβ+siRNA group(P<0.05) and higher in the Aβ+YHG group(P<0.05) than in the Aβ group. Moreover, the ADAM17 protein expression was lower in the Aβ+siRNA group(P<0.05) and higher in the siRNA+YHG group(P< 0.05) than in the siRNA group. The expression was higher in the Aβ+siRNA+YHG group than in the Aβ+siRNA group(P<0.05). The results of Western blot and real-time PCR were consistent with those of immunofluorescence. The experiment showed that YHG induced hepcidin to up-regulate the expression of ADAM17 in AD cell model and promote the activation of non-starch metabolic pathways, which might be the internal mechanism of YHG in preventing and treating AD.
ADAM17 Protein ; Alzheimer Disease/genetics* ; Amyloid beta-Peptides ; Drugs, Chinese Herbal/pharmacology* ; Hepcidins/genetics* ; Humans ; Pueraria

OBJECTIVE: To explore the association between expression of ADAM17 and cetuximad resistance in human colorectal cancer SW480 cells. METHODS: The expression of ADAM17 was detected using Western blotting in different human colorectal cancer cell lines, and the cells highly expressing ADAM17 were selected as the target cells. SW480 cells were transfected with ADAM17-siRNA 1 and ADAM17-siRNA 2 and the changes in the expression of ADAM17 protein were detected using Western blotting. SW480 cells were exposed to cetuximad for 24 h and the cell apoptosis was analyzed using flow cytometry. Transwell assay was used to examine the migration ability of SW480 cells with different expression levels of ADAM17; Western blotting was used to analyze the changes in the expressions of AKT signaling pathway-related proteins in the treated cells. RESULTS: The baseline expressions of ADAM17 were significantly higher in SW480 cells than in the other human colorectal cancer cell lines tested ( < 0.05). Both ADAM17-siRNA 1 and 2 effectively reduced the expression of ADAM17 protein in SW480 cells. Knockdown of ADAM17 with siRNA 1 significantly increased the sensitivity of SW480 cells to tocetuximad ( < 0.05), obviously inhibited the cell proliferation, migration and invasion, and significantly reduced the expressions of p-EGFR and p-AKT in the cells ( < 0.001). CONCLUSIONS ADAM17 knockdown obviously inhibits EGFR-AKT signaling pathway and increases the sensitivity of SW480 cells to tocetuximad.
ADAM17 Protein ; genetics ; metabolism ; Antineoplastic Agents, Immunological ; pharmacology ; Apoptosis ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Cetuximab ; pharmacology ; Colorectal Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; Drug Resistance, Neoplasm ; genetics ; ErbB Receptors ; metabolism ; Gene Knockdown Techniques ; Humans ; Neoplasm Invasiveness ; Oncogene Protein v-akt ; metabolism ; RNA, Small Interfering ; Signal Transduction ; Transfection ; methods

Glycoprotein (GP) Ibα ectodomain shedding has important implications for thrombosis and hemostasis. A disintegrin and metalloproteinase 17 (ADAM17) was identified to play an essential role in agonist induced GPIbα shedding. The relationship of GPIbα shedding and ADAM17 in the acute stage of atherosclerotic ischemic stroke (AIS) patients has not been thoroughly studied. A total of 306 patients and 230 controls matched for age, sex, race, history of hypertension and diabetes mellitus were enrolled in the study. GPIbα, ADAM17, glycocalicin were detected by flow cytometry, Western blotting, and enzyme-linked immunosorbent assay (ELISA) respectively. Compared with the control group, the expression of GPIbα in patients with acute ischemic stroke was significantly lower (P=0.000, P<0.01). Plasma glycocalicin and ADAM17 in AIS group were higher than those in control group (P=0.699, P=0.000). Pearson's analysis showed glycocalicin bore no correlation with GPIbα in AIS patients (r=0.095, P>0.05). GPIbα and National Institute of Health Stroke Scale (NIHSS) had negative correlation (r=-0.514, P<0.01). Our findings indicate that ADAM17 may be a risk factor for ischemic stroke in Chinese and the expression of GPIbα can serve as a measure for stroke severity.
ADAM Proteins ; blood ; ADAM17 Protein ; Biomarkers ; blood ; Blood Platelets ; metabolism ; Brain Ischemia ; blood ; diagnosis ; China ; Female ; Humans ; Intracranial Arteriosclerosis ; blood ; diagnosis ; Male ; Middle Aged ; Platelet Glycoprotein GPIb-IX Complex ; metabolism ; Reproducibility of Results ; Sensitivity and Specificity ; Severity of Illness Index ; Stroke ; blood ; diagnosis

OBJECTIVETo investigate the expression of A disintegrin and metalloproteinase 17 (ADAM17) mRNA and ADAM17 protein in esophageal squamous cell carcinoma (ESCC), and to evaluate their correlation with clinicopathological features and prognosis.

METHODSThe expression of ADAM17 mRNA in 50 ESCC and 50 normal esophageal tissues was detected by RT-PCR. The expression of ADAM17 protein in 80 ESCC and 80 normal esophageal tissues was detected with immunohistochemioal staining (SP). Log rank test and Cox proportional hazards analysis were used to analyze the prognosis of ESCC.

RESULTSThe expression of ADAM17 mRNA in 50 ESCC and 50 normal esophageal tissues was 0.937 ± 0.241 and 0.225 ± 0.077, respectively. The positive expression rates of ADAM17 protein in 80 ESCC and 80 normal esophageal tissues was 66.2% and 6.2%, respectively. The expressions of ADAM17 mRNA and ADAM17 protein in the ESCC were significantly higher than those in normal esophageal tissues (P < 0.01). The expressions of ADAM17 mRNA and protein were positively correlated with lymph node metastasis and TNM staging (P < 0.05). There were no correlations between the expressions of ADAM17 mRNA and protein and sex, age and histological grade (P > 0.05) . The expression of ADAM17 protein was positively correlated with EGFR protein (P < 0.01). The lymph node metastasis, TNM staging and the expression of ADAM17 and EGFR protein were independent prognostic factors.

CONCLUSIONSADAM17 mRNA and protein are highly expressed in ESCC than in normal esophageal tissues and may play an important role in the development, invasion and metastasis of ESCC. They may be used as prognostic factors of ESCC.

ADAM Proteins ; genetics ; metabolism ; ADAM17 Protein ; Aged ; Biomarkers, Tumor ; metabolism ; Carcinoma, Squamous Cell ; metabolism ; pathology ; surgery ; Esophageal Neoplasms ; metabolism ; pathology ; surgery ; Female ; Follow-Up Studies ; Humans ; Kaplan-Meier Estimate ; Lymphatic Metastasis ; Male ; Middle Aged ; Neoplasm Staging ; Proportional Hazards Models ; RNA, Messenger ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Survival Rate

Ebosin is a novel exopolysaccharide produced by Streptomyces sp.139 with remarkable activity against rheumatic arthritis in vivo. In this paper, we reported effects of Ebosin on the inflammatory cytokines including interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFalpha) in THP-1 cells. With the special fluorogenic peptide as substrates, the enzymatic activities of interleukin-1beta converting enzyme (ICE) and TNFalpha-converting enzyme (TACE) were inhibited by Ebosin separately. Using the real-time reverse transcription polymerase chain reaction (real-time PCR), the mRNA synthesis of the three cytokines were identified decline separately by Ebosin. The secretion quantum of three cytokines in THP-1 cells with Ebosin was lower than that of normal THP-1 cells determined by ELISA assay and Western blotting. All of these results showed that Ebosin has remarkably suppressed synthesis of the three cytokines in THP-1 cells through different pathways. The primary study of Ebosin on anti-inflammation mechanism was promoted developing the new drugs treating rheumatic arthritis.
ADAM Proteins ; metabolism ; ADAM17 Protein ; Anti-Inflammatory Agents ; pharmacology ; Caspase 1 ; metabolism ; Cell Line, Tumor ; Humans ; Interleukin-1beta ; genetics ; metabolism ; Interleukin-6 ; genetics ; metabolism ; Leukemia, Monocytic, Acute ; metabolism ; pathology ; Polysaccharides, Bacterial ; biosynthesis ; pharmacology ; RNA, Messenger ; metabolism ; Streptomyces ; metabolism ; Tumor Necrosis Factor-alpha ; genetics ; metabolism

OBJECTIVETo study the effect of siRNA targeting ADAM17 (ADAM17-siRNA) on the proliferation of prostate cancer PC-3 cells.

METHODSAfter transfecting PC-3 cells with ADAM17-siRNA 1 and ADAM17-siRNA 2, we detected the expressions of ADAM17 mRNA and protein by RT- PCR and Western blotting, respectively. We measured the changes in the proliferation and DNA synthesis of PC-3 cells by MTT and bromodeoxyuridine (BrdU) incorporation assay, examined the cell cycle profile by flow cytometry, and determined the expressions of the genes associated with PC-3 cell proliferation by Western blotting.

RESULTSBoth ADAM17-siRNA 1 and 2 effectively reduced the expressions of ADAM17 mRNA and protein in the PC-3 cells. Knockdown of ADAM17 with the two siRNAs significantly inhibited cell proliferation as compared with the control group (0.43 +/- 0.57 and 0.44 +/- 0.64 vs 0.80 +/- 0.51, P < 0.05) and down-regulated DNA synthesis (0.48 +/- 0.43 and 0.54 +/- 0.59 vs 0.79 +/- 0.72, P < 0.05). The cell cycle profile showed that the cell population of the G1 phase was markedly higher in both the ADAM17-siRNA groups than in the control ([61.83 +/- 2.41]% and [59.78 +/- 1.92]% vs [41.38 +/- 1.53]%, P < 0.05), but that of the S phase remarkably lower in the former two than in the latter ([23.64 +/- 2.56]% and [25.24 +/- 1.86]% vs [33.51 +/- 1.47]%, P < 0.05), with a concomitant decrease in the expression of the cell cycle protein cyclin D1 and increase in the cyclin-dependent kinase inhibitor p21.

CONCLUSIONADAM17-siRNA can effectively inhibit the proliferation of PC-3 cells by up-regulating cyclin D1 and down-regulating p21 protein, and ADAM17 has a potential value in the gene therapy of prostate cancer.

ADAM Proteins ; genetics ; metabolism ; ADAM17 Protein ; Cell Line, Tumor ; Cell Proliferation ; Cyclin D1 ; metabolism ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Down-Regulation ; Humans ; Male ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; RNA Interference ; RNA, Messenger ; genetics ; RNA, Small Interfering ; genetics ; Signal Transduction ; Transfection

OBJECTIVETo investigate the main proteinases responsible for CD16b shedding under different stimulators.

METHODSHEK293 cell line stably expressing CD16b was constructed by lentivirus system. The cell line was then overexpressed with a disintegrin and metalloproteinase 10 (ADAM10) or ADAM17, suppressed with short hairpin RNA of ADAM10 or ADAM17, and reconstituted with ADAM10 or ADAM17, respectively. After each treatment, the cell line was stimulated with ionomycin or phorbol 12-myristate- 13-acetate (PMA) for 12 hours. The soluble CD16b released from cell membrane was detected by immunoprecipition and immunoblot. Quantitation was then implemented to compare the amount of soluble CD16b in cell supernatant after stimulation.

RESULTSHEK293 cell line stably expressing CD16b was successfully established. When CD16b expressing cell line was overexpressed with ADAM10, shedding of CD16b was increased after stimulation with ionomycin but not PMA; when the cell line overexpressed with ADAM17, shedding of CD16b was increased after stimulation with PMA but not ionomycin. Similarly, when ADAM10 was suppressed by short hairpin RNA, CD16b shedding was decreased after stimulation with ionomycin; when ADAM17 was suppressed by short hairpin RNA, CD16b shedding was decreased after stimulation with PMA. The shedding of CD16b was increased again when CD16b expressing cell line was reconstituted with ADAM10 and stimulated by ionomycin or reconstituted with ADAM17 and stimulated by PMA.

CONCLUSIONSBoth ADAM10 and ADAM17 could shed CD16b, but they possess differed preferences. ADAM10 is the main sheddase under stimulation of ionomycin, while ADAM17 is the main sheddase under stimulation of PMA.

ADAM Proteins ; genetics ; metabolism ; physiology ; ADAM10 Protein ; ADAM17 Protein ; Amyloid Precursor Protein Secretases ; genetics ; metabolism ; physiology ; Calcium Ionophores ; pharmacology ; Carcinogens ; pharmacology ; Cells, Cultured ; Drug Evaluation, Preclinical ; GPI-Linked Proteins ; metabolism ; Gene Knockdown Techniques ; HEK293 Cells ; Humans ; Ionomycin ; pharmacology ; Membrane Proteins ; genetics ; metabolism ; physiology ; Protein Processing, Post-Translational ; drug effects ; Protein Transport ; drug effects ; Proteolysis ; drug effects ; Receptors, IgG ; metabolism ; Tetradecanoylphorbol Acetate ; pharmacology ; Transfection

The sigma-1 receptor is a molecular chaperone protein highly enriched in the brain. Recent studies linked it to many diseases, such as drug addition, Alzheimer's disease, stroke, depression, and even cancer. Sigma-1 receptor is enriched in lipid rafts, which are membrane microdomains essential in signaling processes. One of those signaling processes is ADAM17- and ADAM10-dependent ectodomain shedding. By using an alkaline phosphatase tagged substrate reporter system, we have shown that ADAM10-dependent BTC shedding was very sensitive to both membrane lipid component change and sigma-1 receptor agonist DHEAS treatment while ADAM17-dependent HB-EGF shedding was not; and overexpression of sigma-1 receptor diminished ADAM17- and ADAM10-dependent shedding. Our results indicate that sigma-1 receptor plays an important role in modifying the function of transmembrane proteases.
ADAM Proteins ; metabolism ; ADAM10 Protein ; ADAM17 Protein ; Amyloid Precursor Protein Secretases ; metabolism ; Animals ; Betacellulin ; COS Cells ; Cercopithecus aethiops ; Gene Expression ; HEK293 Cells ; Heparin-binding EGF-like Growth Factor ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Membrane Microdomains ; metabolism ; Membrane Proteins ; metabolism ; Receptors, sigma ; agonists ; metabolism

ADAM Proteins ; genetics ; ADAM17 Protein ; Animals ; Gene Library ; Genetic Vectors ; Male ; Mice ; Two-Hybrid System Techniques

ADAM Proteins ; genetics ; ADAM17 Protein ; Adrenergic beta-Antagonists ; therapeutic use ; Animals ; Male ; Metoprolol ; therapeutic use ; Myocardial Infarction ; drug therapy ; physiopathology ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; genetics ; Ventricular Function, Left ; drug effects ; Ventricular Remodeling ; drug effects