A Disintegrin And Metalloprotease 10 Expression Research Articles

Silencing ADAM10 inhibits the in vitro and in vivo growth of hepatocellular carcinoma cancer cells.

A disintegrin and metalloprotease 10 (ADAM10) is a transmembrane protein associated with metastasis in a number of types of cancer. Little is known, however, regarding the role of ADAM10 in hepatocellular carcinoma (HCC). The aim of the present study was to evaluate whether downregulation of ADAM10 effects HCC cell proliferation, cell cycle, cell migration and cell invasion. A recombinant small hairpin RNA expression vector carrying ADAM10 was constructed and then transfected into the HepG2 human HCC cell line. In vitro cell proliferation, cell cycle, cell migration and cell invasion, and in vivo tumor growth were determined following the downregulation of ADAM10 by RNA interference. The results revealed that downregulation of ADAM10 expression in HepG2 tumor cells using the RNA silencing approach significantly suppressed cell proliferation, cell migration and cell invasion in vitro, and tumor growth in vivo. Furthermore, ADAM10 silencing was able to significantly reduce constitutive phosphorylation of phosphoinositide 3-kinase (PI3K) and Akt, which implies that ADAM10 is, at least partially, involved in the activation of the PI3K/Akt signaling pathway. These results suggest that ADAM10 is important in regulating the proliferation and metastasis of HCC. Thus, ADAM10 is a promising therapeutic target for the prevention of tumor metastases in HCC.

ADAM10 regulates proliferation, invasion, and chemoresistance of bladder cancer cells

A disintegrin and metalloprotease 10 (ADAM10) is upregulated in several cancers and associates with malignant cancer progression. However, its expression pattern in bladder cancer remains unexplored. In the present study, we examined ADAM10 expression in 105 bladder cancer specimens using immunohistochemistry. We found ADAM10 overexpression in 51 of 105 (48.5 %) bladder cancer specimens. ADAM10 overexpression associated with advanced tumor stage (p = 0.001) and tumor grade (p = 0.018). To explore its biological functions in bladder cancer cells, small interfering RNA (siRNA) knockdown was performed in 5,637 and T24 cell lines. Cell Counting Kit-8 (CCK8) assay and Matrigel invasion assay showed that ADAM10 depletion decreased cell proliferation, migration, and invasion. In addition, ADAM10 knockdown increased the level of cisplatin-induced apoptosis. In conclusion, ADAM10 is overexpressed in bladder cancer and regulates malignant cell growth and invasion, which makes it a candidate therapeutic target.

Tumor necrosis factor-α-induced a disintegrin and metalloprotease 10 increases apoptosis resistance in prostate cancer cells

In developed countries, prostate cancer (PCa) is the second most frequently diagnosed type of cancer and the third most common cause of cancer-related mortality in males. Compared with western countries, the morbidity rate of PCa in China is markedly lower, however, it is rising annually. The etiology of PCa is unclear, therefore, to investigate how a disintegrin and metalloprotease 10 (ADAM10) functions in PCa, ADAM10 mRNA and protein levels induced by tumor necrosis factor (TNF)-α were identified using polymerase chain reaction and flow cytometry, respectively. To investigate the mechanism of ADAM10 activity in PCa, specific inhibitors were used, and DNA transfection and RNA interference technology were employed to identify the interaction between ADAM10 and the Fas ligand (L). The results indicated that TNF-α induced ADAM10 expression in a time- and dose-dependent manner through the p38 mitogen-activated protein kinase/necrosis factor-κB signaling pathway. ADAM10 hydrolyzed FasL and contributed to apoptosis resistance of the tumor cells. These observations indicate a promising therapeutic modality for the treatment of apoptosis-resistant PCa, by targeting ADAM10 sheddase activity.

MicroRNA-144 Is Regulated by Activator Protein-1 (AP-1) and Decreases Expression of Alzheimer Disease-related A Disintegrin and Metalloprotease 10 (ADAM10)

MicroRNA (miR) dysregulation is found in Alzheimer disease (AD). A disintegrin and metalloprotease 10 (ADAM10) prevents generation of amyloid β (Aβ) and decrease AD pathology. miR-144 suppresses ADAM10 expression and is up-regulated by activator protein-1. miR-144 is a negative regulator of ADAM10 and may be involved in AD pathogenesis. The first work to demonstrate the function of miRNA-144 and its regulation in the pathogenesis of AD. Amyloid β-peptide (Aβ) accumulating in the brain of Alzheimer disease (AD) patients is believed to be the main pathophysiologcal cause of the disease. Proteolytic processing of the amyloid precursor protein by α-secretase ADAM10 (a disintegrin and metalloprotease 10) protects the brain from the production of the Aβ. Meanwhile, dysregulation or aberrant expression of microRNAs (miRNAs) has been widely documented in AD patients. In this study, we demonstrated that overexpression of miR-144, which was previously reported to be increased in elderly primate brains and AD patients, significantly decreased activity of the luciferase reporter containing the ADAM10 3'-untranslated region (3'-UTR) and suppressed the ADAM10 protein level, whereas the miR-144 inhibitor led to an increase of the luciferase activity. The negative regulation caused by miR-144 was strictly dependent on the binding of the miRNA to its recognition element in the ADAM10 3'-UTR. Moreover, we also showed that activator protein-1 regulates the transcription of miR-144 and the up-regulation of miR-144 at least partially induces the suppression of the ADAM10 protein in the presence of Aβ. In addition, we found that miR-451, a miRNA processed from a single gene locus with miR-144, is also involved in the regulation of ADAM10 expression. Taken together, our data therefore demonstrate miR-144/451 is a negative regulator of the ADAM10 protein and suggest a mechanistic role for miR-144/451 in AD pathogenesis.

A Disintegrin and Metalloprotease 10 in neuronal maturation and gliogenesis during cortex development.

The multiple-layer structure of the cerebral cortex is important for its functions. Such a structure is generated based on the proliferation and differentiation of neural stem/progenitor cells. Notch functions as a molecular switch for neural stem/progenitor cell fate during cortex development but the mechanism remains unclear. Biochemical and cellular studies showed that Notch receptor activation induces several proteases to release the Notch intracellular domain (NICD). A Disintegrin and Metalloprotease 10 (ADAM10) might be a physiological rate-limiting S2 enzyme for Notch activation. Nestin-driven conditional ADAM10 knockout in mouse cortex showed that ADAM10 is critical for maintenance of the neural stem cell population during early embryonic cortex development. However, the expression pattern and function of ADAM10 during later cerebral cortex development remains poorly understood. We performed in situ hybridization for ADAM10 mRNA and immunofluorescent analysis to determine the expression of ADAM10 and NICD in mouse cortex from embryonic day 9 (E14.5) to postnatal day 1 (P1). ADAM10 and NICD were highly co-localized in the cortex of E16.5 to P1 mice. Comparisons of expression patterns of ADAM10 with Nestin (neural stem cell marker), Tuj1 (mature neuron marker), and S100β (glia marker) showed that ADAM10 expression highly matched that of S100β and partially matched that of Tuj1 at later embryonic to early postnatal cortex developmental stages. Such expression patterns indicated that ADAM10-Notch signaling might have a critical function in neuronal maturation and gliogenesis during cortex development.

The TspanC8 Subgroup of Tetraspanins Interacts with A Disintegrin and Metalloprotease 10 (ADAM10) and Regulates Its Maturation and Cell Surface Expression

A disintegrin and metalloprotease 10 (ADAM10) is a ubiquitous transmembrane metalloprotease that cleaves the extracellular regions from over 40 different transmembrane target proteins, including Notch and amyloid precursor protein. ADAM10 is essential for embryonic development and is also important in inflammation, cancer, and Alzheimer disease. However, ADAM10 regulation remains poorly understood. ADAM10 is compartmentalized into membrane microdomains formed by tetraspanins, which are a superfamily of 33 transmembrane proteins in humans that regulate clustering and trafficking of certain other transmembrane "partner" proteins. This is achieved by specific tetraspanin-partner interactions, but it is not clear which tetraspanins specifically interact with ADAM10. The aims of this study were to identify which tetraspanins interact with ADAM10 and how they regulate this metalloprotease. Co-immunoprecipitation identified specific ADAM10 interactions with Tspan5, Tspan10, Tspan14, Tspan15, Tspan17, and Tspan33/Penumbra. These are members of the largely unstudied TspanC8 subgroup of tetraspanins, all six of which promoted ADAM10 maturation. Different cell types express distinct repertoires of TspanC8 tetraspanins. Human umbilical vein endothelial cells express relatively high levels of Tspan14, the knockdown of which reduced ADAM10 surface expression and activity. Mouse erythrocytes express predominantly Tspan33, and ADAM10 expression was substantially reduced in the absence of this tetraspanin. In contrast, ADAM10 expression was normal on Tspan33-deficient mouse platelets in which Tspan14 is the major TspanC8 tetraspanin. These results define TspanC8 tetraspanins as essential regulators of ADAM10 maturation and trafficking to the cell surface. This finding has therapeutic implications because focusing on specific TspanC8-ADAM10 complexes may allow cell type- and/or substrate-specific ADAM10 targeting.

Self-Control of HGF Regulation on Human Trophoblast Cell Invasion via Enhancing c-Met Receptor Shedding by ADAM10 and ADAM17

Hepatocyte growth factor (HGF)/c-Met signaling has been implicated in mammalian placental development. Integral c-Met can be released from endothelial cell membrane by proteolysis to form a soluble, truncated protein [soluble Met (sMet)], which is biochemically able to bind HGF and may disrupt HGF/c-Met signaling. By far, production of sMet in human placenta has not been reported, and the shedding mechanism remains unclear. In this study, production of sMet in healthy pregnant placenta and preeclamptic ones was compared, and the role of sMet on trophoblast cell invasion as well as the regulation of c-Met shedding by HGF were investigated in an immortal trophoblast cell line, B6Tert-1. Placenta productions of sMet, pro- and active forms of a disintegrin and metalloprotease 10 (ADAM10) and ADAM17 in preeclamptic patients were significantly higher than those in normal pregnant women. In B6Tert-1 cells, the HGF-induced promotion on cell invasion and activation of MAPK and AKT could be extensively blocked by sMet. ADAM10 and ADAM17, but not ADAM12, were explored to be sheddases of c-Met. HGF down-regulated c-Met receptor expression, whereas it up-regulated pro- and active/mature forms of ADAM10 and ADAM17 expression, which resulted in enhanced sMet production. Stimulation of H(2)O(2) caused an increase in active ADAM10, pro-ADAM17, and active ADAM17 levels and thus excessive c-Met shedding. HGF could negatively self-control its regulatory effect on trophoblast cell invasion via enhancing proteolysis of its receptor. Unbalancing of HGF self-control by oxidative stress may lead to impeding placentation in relevance to preeclampsia.

A Functional Role for ADAM10 in Human Immunodeficiency Virus Type-1 Replication

BackgroundGene trap insertional mutagenesis was used as a high-throughput approach to discover cellular genes participating in viral infection by screening libraries of cells selected for survival from lytic infection with a variety of viruses. Cells harboring a disrupted ADAM10 (A Disintegrin and Metalloprotease 10) allele survived reovirus infection, and subsequently ADAM10 was shown by RNA interference to be important for replication of HIV-1.ResultsSilencing ADAM10 expression with small interfering RNA (siRNA) 48 hours before infection significantly inhibited HIV-1 replication in primary human monocyte-derived macrophages and in CD4+ cell lines. In agreement, ADAM10 over-expression significantly increased HIV-1 replication. ADAM10 down-regulation did not inhibit viral reverse transcription, indicating that viral entry and uncoating are also independent of ADAM10 expression. Integration of HIV-1 cDNA was reduced in ADAM10 down-regulated cells; however, concomitant 2-LTR circle formation was not detected, suggesting that HIV-1 does not enter the nucleus. Further, ADAM10 silencing inhibited downstream reporter gene expression and viral protein translation. Interestingly, we found that while the metalloprotease domain of ADAM10 is not required for HIV-1 replication, ADAM15 and γ-secretase (which proteolytically release the extracellular and intracellular domains of ADAM10 from the plasma membrane, respectively) do support productive infection.ConclusionsWe propose that ADAM10 facilitates replication at the level of nuclear trafficking. Collectively, our data support a model whereby ADAM10 is cleaved by ADAM15 and γ-secretase and that the ADAM10 intracellular domain directly facilitates HIV-1 nuclear trafficking. Thus, ADAM10 represents a novel cellular target class for development of antiretroviral drugs.

Role of a disintegrin and metalloprotease 10 in Staphylococcus aureus α-hemolysin–mediated cellular injury

Staphylococcus aureus alpha-hemolysin (Hla), a potent cytotoxin, plays an important role in the pathogenesis of staphylococcal diseases, including those caused by methicillin-resistant epidemic strains. Hla is secreted as a water-soluble monomer that undergoes a series of conformational changes to generate a heptameric, beta-barrel structure in host membranes. Structural maturation of Hla depends on its interaction with a previously unknown proteinaceous receptor in the context of the cell membrane. It is reported here that a disintegrin and metalloprotease 10 (ADAM10) interacts with Hla and is required to initiate the sequence of events whereby the toxin is transformed into a cytolytic pore. Hla binding to the eukaryotic cell requires ADAM10 expression. Further, ADAM10 is required for Hla-mediated cytotoxicity, most notably when the toxin is present at low concentrations. These data thus implicate ADAM10 as the probable high-affinity toxin receptor. Upon Hla binding, ADAM10 relocalizes to caveolin 1-enriched lipid rafts that serve as a platform for the clustering of signaling molecules. It is demonstrated that the Hla-ADAM10 complex initiates intracellular signaling events that culminate in the disruption of focal adhesions.

Expression of the Anti-amyloidogenic Secretase ADAM10 Is Suppressed by Its 5′-Untranslated Region

Proteolytic processing of the amyloid precursor protein by alpha-secretase prevents formation of the amyloid beta-peptide (Abeta), which is the main constituent of amyloid plaques in brains of Alzheimer disease (AD) patients. alpha-Secretase activity is decreased in AD, and overexpression of the alpha-secretase ADAM10 (a disintegrin and metalloprotease 10) in an AD animal model prevents amyloid pathology. ADAM10 has a 444-nucleotide-long, very GC-rich 5'-untranslated region (5'-UTR) with two upstream open reading frames. Because similar properties of 5'-UTRs are found in transcripts of many genes, which are regulated by translational control mechanisms, we asked whether ADAM10 expression is translationally controlled by its 5'-UTR. We demonstrate that the 5'-UTR of ADAM10 represses the rate of ADAM10 translation. In the absence of the 5'-UTR, we observed a significant increase of ADAM10 protein levels in HEK293 cells, whereas mRNA levels were not changed. Moreover, the 5'-UTR of ADAM10 inhibits translation of a luciferase reporter in an in vitro transcription/translation assay. Successive deletion of the first half of the ADAM10 5'-UTR revealed a striking increase in ADAM10 protein expression in HEK293 cells, suggesting that this part of the 5'-UTR contains inhibitory elements for translation. Moreover, we detect an enhanced alpha-secretase activity and consequently reduced Abeta levels in the conditioned medium of HEK293 cells expressing both amyloid precursor protein and a 5'-UTR-ADAM10 deletion construct lacking the first half of the 5'-UTR. Thus, we provide evidence that the 5'-UTR of ADAM10 may have an important role for post-transcriptional regulation of ADAM10 expression and consequently Abeta production.