A Disintegrin And Metalloproteinase 17 Expression Research Articles

NACC1 accelerates the progression of AML by regulating the ADAM9/PI3K/AKT axis.

Nucleus accumbens-associated protein 1 (NACC1) regulates various types of biological processes. It is a transcription factor associated with cancer. NACC1 is overexpressed in many human malignancies and can regulate the progression, metastasis, and drug resistance of cancer cells. However, its precise role in acute myeloid leukemia (AML) remains unknown. This study aimed to unravel the basic mechanism of NACC1 in AML. Our findings demonstrated that NACC1 is immensely expressed in AML cells. Lentiviral vector-mediated knockdown of NACC1 inhibited the PI3K/AKT signaling pathway. Simultaneously, NACC1 knockdown promoted apoptosis, suppressed the proliferative capacity of AML cells, and resulted in cell cycle arrest during the G0/G1 phase. Additionally, A disintegrin and metalloproteinase 9 (ADAM9) was markedly expressed in AML cells. NACC1 regulated ADAM9 expression. ADAM9 expression was also downregulated after NACC1 knockdown. Concurrently, ADAM9 knockdown affected the activity of AML cells by decelerating the growth rate, promoting apoptosis, and blocking cell cycle progression. In addition, the AKT activator SC79 restored the inhibited cell proliferation after NACC1 knockdown and ADAM9 knockdown. In conclusion, our study suggested that the NACC1/ADAM9/PI3K/AKT axis is crucial for sustaining the survival of AML cells, indicating that NACC1 may be a viable target for treating AML.

NRF2 activation by 6-MSITC increases the generation of neuroprotective, soluble α amyloid precursor protein by inducing the metalloprotease gene ADAM17

Better knowledge of the molecular actors governing sequential amyloid precursor protein (APP) proteolysis is crucial to endorse novel therapies aimed to delay Alzheimer's disease (AD) progression. ADAM17 (A Disintegrin and Metalloproteinase 17) is a type-I transmembrane protease involved in the non-amyloidogenic processing of APP that contributes to the maintenance of synaptic functions. In this work, we analyzed the 5′-flanking region and first intron of ADAM17 gene employing an in silico analysis. This strategy evidenced two regions which concentrate the binding sites of diverse transcription factor-families, including members of the b-ZIP small MAF, NRF2 and BACH1 proteins. Then, we found that the natural isothiocyanate 6-MSITC (6 methylsulfinyl hexyl isothiocyanate) increased both mRNA and protein levels of ADAM17 in an NRF2-dependent manner. In line, SH-SY5Y neurons released higher levels of the soluble APPα peptide as a result of ADAM17 activation. Overall, our study identifies inducible expression of ADAM17, and consequently protease activity, by NRF2.

Chronic intermittent hypoxia facilitates the development of angiotensin II-induced abdominal aortic aneurysm in male mice.

Obstructive sleep apnea (OSA), characterized by episodes of intermittent hypoxia (IH), is highly prevalent in patients with abdominal aortic aneurysm (AAA). However, whether IH serves as an independent risk factor for AAA development remains to be investigated. Here, we determined the effects of chronic (6 mo) IH on angiotensin (Ang II)-induced AAA development in C57BL/6J male mice and investigated the underlying mechanisms of IH in cultured vascular smooth muscle cells (SMCs). IH increased the susceptibility of mice to develop AAA in response to Ang II infusion by facilitating the augmentation of the abdominal aorta's diameter as assessed by transabdominal ultrasound imaging. Importantly, IH with Ang II augmented aortic elastin degradation and the expression of matrix metalloproteinases (MMPs), mainly MMP8, MMP12, and a disintegrin and metalloproteinase-17 (ADAM17) as measured by histology and immunohistochemistry. Mechanistically, IH increased the activities of MMP2, MMP8, MMP9, MMP12, and ADAM17, while reducing the expression of the MMP regulator reversion-inducing cysteine-rich protein with Kazal motifs (RECK) in cultured SMCs. Aortic samples from human AAA were associated with decreased RECK and increased expression of ADAM17 and MMPs. These data suggest that IH facilitates AAA development when additional stressors are superimposed and that this occurs in association with an increased presence of aortic MMPs and ADAM17, potentially due to IH-induced modulation of RECK expression. These findings support a plausible synergistic link between OSA and AAA and provide a better understanding of the molecular mechanisms underlying the pathogenesis of AAA.NEW & NOTEWORTHY IH facilitates Ang II-induced abdominal aortic diameter expansion and AAA development in C57BL/6J male mice. IH upregulates the expression of specific MMPs such as MMP8, MMP12, and ADAM17. IH directly suppresses RECK expression and increases MMPs activity in SMCs. Human AAA tissues exhibit a downregulation of RECK and an upregulation of ADAM17 and MMPs.

Coagulation factor XI regulates endothelial cell permeability and barrier function in vitro and in vivo

AbstractLoss of endothelial barrier function contributes to the pathophysiology of many inflammatory diseases. Coagulation factor XI (FXI) plays a regulatory role in inflammation. Although activation of FXI increases vascular permeability in vivo, the mechanism by which FXI or its activated form FXIa disrupts endothelial barrier function is unknown. We investigated the role of FXIa in human umbilical vein endothelial cell (HUVEC) or human aortic endothelial cell (HAEC) permeability. The expression patterns of vascular endothelial (VE)-cadherin and other proteins of interest were examined by western blot or immunofluorescence. Endothelial cell permeability was analyzed by Transwell assay. We demonstrate that FXIa increases endothelial cell permeability by inducing cleavage of the VE-cadherin extracellular domain, releasing a soluble fragment. The activation of a disintegrin and metalloproteinase 10 (ADAM10) mediates the FXIa-dependent cleavage of VE-cadherin, because adding an ADAM10 inhibitor prevented the cleavage of VE-cadherin induced by FXIa. The binding of FXIa with plasminogen activator inhibitor 1 and very low–density lipoprotein receptor on HUVEC or HAEC surfaces activates vascular endothelial growth receptor factor 2 (VEGFR2). The activation of VEGFR2 triggers the mitogen-activated protein kinase (MAPK) signaling pathway and promotes the expression of active ADAM10 on the cell surface. In a pilot experiment using an established baboon model of sepsis, the inhibition of FXI activation significantly decreased the levels of soluble VE-cadherin to preserve barrier function. This study reveals a novel pathway by which FXIa regulates vascular permeability. The effect of FXIa on barrier function may be another way by which FXIa contributes to the development of inflammatory diseases.

Alpha-lipoic acid alleviates cognitive deficits in transgenic APP23/PS45 mice through a mitophagy-mediated increase in ADAM10 α-secretase cleavage of APP

BackgroundAlpha-lipoic acid (ALA) has a neuroprotective effect on neurodegenerative diseases. In the clinic, ALA can improve cognitive impairments in patients with Alzheimer’s disease (AD) and other dementias. Animal studies have confirmed the anti-amyloidosis effect of ALA, but its underlying mechanism remains unclear. In particular, the role of ALA in amyloid-β precursor protein (APP) metabolism has not been fully elucidated.ObjectiveTo investigate whether ALA can reduce the amyloidogenic effect of APP in a transgenic mouse model of AD, and to study the mechanism underlying this effect.MethodsALA was infused into 2-month-old APP23/PS45 transgenic mice for 4 consecutive months and their cognitive function and AD-like pathology were then evaluated. An ALA drug concentration gradient was applied to 20E2 cells in vitro to evaluate its effect on the expression of APP proteolytic enzymes and metabolites. The mechanism by which ALA affects APP processing was studied using GI254023X, an inhibitor of A Disintegrin and Metalloproteinase 10 (ADAM10), as well as the mitochondrial toxic drug carbonyl cyanide m-chlorophenylhydrazone (CCCP).ResultsAdministration of ALA ameliorated amyloid plaque neuropathology in the brain tissue of APP23/PS45 mice and reduced learning and memory impairment. ALA also increased the expression of ADAM10 in 20E2 cells and the non-amyloidogenic processing of APP to produce the 83 amino acid C-terminal fragment (C83). In addition to activating autophagy, ALA also significantly promoted mitophagy. BNIP3L-knockdown reduced the mat/pro ratio of ADAM10. By using CCCP, ALA was found to regulate BNIP3L-mediated mitophagy, thereby promoting the α-cleavage of APP.ConclusionsThe enhanced α-secretase cleavage of APP by ADAM10 is the primary mechanism through which ALA ameliorates the cognitive deficits in APP23/PS45 transgenic mice. BNIP3L-mediated mitophagy contributes to the anti-amyloid properties of ALA by facilitating the maturation of ADAM10. This study provides novel experimental evidence for the treatment of AD with ALA.Graphical abstract

α5-nAChR/ADAM10 signaling mediates nicotine-related cutaneous melanoma progression via STAT3 activation.

Skin cutaneous melanoma (SKCM) is the skin malignancy with the highest mortality rate, and its morbidity rate is on the rise worldwide. Smoking is an independent marker of poor prognosis in melanoma. The α5-nicotinic acetylcholine receptor (α5-nAChR), one of the receptors for nicotine, is involved in the proliferation, migration and invasion of SKCM cells. Nicotine has been reported to promote the expression of a disintegrin and metalloproteinase 10 (ADAM10), which is the key gene involved in melanoma progression. Here, we explored the link between α5-nAChR and ADAM10 in nicotine-associated cutaneous melanoma. α5-nAChR expression was correlated with ADAM10 expression and lower survival in SKCM. α5-nAChR mediated nicotine-induced ADAM10 expression via STAT3. The α5-nAChR/ADAM10 signaling axis was involved in the stemness and migration of SKCM cells. Furthermore, α5-nAChR expression was associated with ADAM10 expression, EMT marker expression and stemness marker expression in nicotine-related mice homograft tissues. These results suggest the role of the α5-nAChR/ADAM10 signaling pathway in nicotine-induced melanoma progression.

The protease ADAM17 at the crossroads of disease: revisiting its significance in inflammation, cancer, and beyond.

The protease A Disintegrin And Metalloproteinase 17 (ADAM17) plays a central role in the pathophysiology of several diseases. ADAM17 is involved in the cleavage and shedding of at least 80 known membrane-tethered proteins, which subsequently modulate several intracellular signaling pathways, and therefore alter cell behavior. Dysregulated expression and/or activation of ADAM17 has been linked to a wide range of autoimmune and inflammatory diseases, cancer, and cardiovascular disease. In this review, we provide an overview of the current state of knowledge from preclinical models and clinical data on the diverse pathophysiological roles of ADAM17, and discuss the mechanisms underlying ADAM17-mediated protein shedding and the potential therapeutic implications of targeting ADAM17 in these diseases.

ADAM17 targeting by human cytomegalovirus remodels the cell surface proteome to simultaneously regulate multiple immune pathways

Human cytomegalovirus (HCMV) is a major human pathogen whose life-long persistence is enabled by its remarkable capacity to systematically subvert host immune defenses. In exploring the finding that HCMV infection up-regulates tumor necrosis factor receptor 2 (TNFR2), a ligand for the pro-inflammatory antiviral cytokine TNFα, we found that the underlying mechanism was due to targeting of the protease, A Disintegrin And Metalloproteinase 17 (ADAM17). ADAM17 is the prototype 'sheddase', a family of proteases that cleaves other membrane-bound proteins to release biologically active ectodomains into the supernatant. HCMV impaired ADAM17 surface expression through the action of two virally-encoded proteins in its UL/b' region, UL148 and UL148D. Proteomic plasma membrane profiling of cells infected with an HCMV double-deletion mutant for UL148 and UL148D with restored ADAM17 expression, combined with ADAM17 functional blockade, showed that HCMV stabilized the surface expression of 114 proteins (P < 0.05) in an ADAM17-dependent fashion. These included reported substrates of ADAM17 with established immunological functions such as TNFR2 and jagged1, but also numerous unreported host and viral targets, such as nectin1, UL8, and UL144. Regulation of TNFα-induced cytokine responses and NK inhibition during HCMV infection were dependent on this impairment of ADAM17. We therefore identify a viral immunoregulatory mechanism in which targeting a single sheddase enables broad regulation of multiple critical surface receptors, revealing a paradigm for viral-encoded immunomodulation.

Apicidin attenuates memory deficits by reducing the Aβ load in APP/PS1 mice.

Amyloid beta (Aβ) is an important pathological feature of Alzheimer's disease (AD). A disintegrin and metalloproteinase 10 (ADAM10) can reduce the production of toxic Aβ by activating the nonamyloidogenic pathway of amyloid precursor protein (APP). We previously found that apicidin, which is a histone deacetylase (HDAC) inhibitor, can promote the expression of ADAM10 and reduce the production of Aβ in vitro. This study was designed to determine the potential of apicidin treatment to reverse learning and memory impairments in an AD mouse model and the possible correlation of these effects with ADAM10. Nine-month-old APP/PS1 mice and C57 mice received intraperitoneal injections of apicidin or vehicle for 2months. At 11 months of age, we evaluated the memory performance of mice with Morris water maze (MWM) and context fear conditioning tests. The Aβ levels were assessed in mouse brain using the immunohistochemical method and ELISA. The expression of corresponding protein involved in proteolytic processing of APP and the phosphorylation of tau were assessed by Western blotting. Apicidin reversed the deficits of spatial reference memory and contextual fear memory, attenuated the formation of Aβ-enriched plaques, and decreased the levels of soluble and insoluble Aβ40/42 in APP/PS1 mice. Moreover, apicidin significantly increased the expression of ADAM10, improved the level of sAPPα, and reduced the production of sAPPβ, but did not affect the levels of phosphorylated tau in APP/PS1 mice. Apicidin significantly improves the AD symptoms of APP/PS1 mice by regulating the expression of ADAM10, which may contribute to decreasing the levels of Aβ rather than decreasing the phosphorylation of tau.

Blockade of the protease ADAM17 ameliorates experimental pancreatitis

Acute and chronic pancreatitis, the latter associated with fibrosis, are multifactorial inflammatory disorders and leading causes of gastrointestinal disease-related hospitalization. Despite the global health burden of pancreatitis, currently, there are no effective therapeutic agents. In this regard, the protease A Disintegrin And Metalloproteinase 17 (ADAM17) mediates inflammatory responses through shedding of bioactive inflammatory cytokines and mediators, including tumor necrosis factor α (TNFα) and the soluble interleukin (IL)-6 receptor (sIL-6R), the latter of which drives proinflammatory IL-6 trans-signaling. However, the role of ADAM17 in pancreatitis is unclear. To address this, Adam17ex/ex mice-which are homozygous for the hypomorphic Adam17ex allele resulting in marked reduction in ADAM17 expression-and their wild-type (WT) littermates were exposed to the cerulein-induced acute pancreatitis model, and acute (1-wk) and chronic (20-wk) pancreatitis models induced by the cigarette smoke carcinogen nicotine-derived nitrosamine ketone (NNK). Our data reveal that ADAM17 expression was up-regulated in pancreatic tissues of animal models of pancreatitis. Moreover, the genetic (Adam17ex/ex mice) and therapeutic (ADAM17 prodomain inhibitor [A17pro]) targeting of ADAM17 ameliorated experimental pancreatitis, which was associated with a reduction in the IL-6 trans-signaling/STAT3 axis. This led to reduced inflammatory cell infiltration, including T cells and neutrophils, as well as necrosis and fibrosis in the pancreas. Furthermore, up-regulation of the ADAM17/IL-6 trans-signaling/STAT3 axis was a feature of pancreatitis patients. Collectively, our findings indicate that the ADAM17 protease plays a pivotal role in the pathogenesis of pancreatitis, which could pave the way for devising novel therapeutic options to be deployed against this disease.

IL-17A Promotes Epithelial ADAM9 Expression in Cigarette Smoke-Related COPD.

BackgroundIt has been reported that a disintegrin and metalloproteinase 9 (ADAM9) is involved in the pathogenesis of cigarette smoke (CS)-associated chronic obstructive pulmonary disease (COPD). But how CS exposure leads to upregulation of ADAM9 remains unknown.MethodsPatients who underwent lobectomy for a solitary pulmonary nodule were enrolled and divided into three groups: non-smokers with normal lung function, smokers without COPD and smoker patients with COPD. Immunoreactivity of interleukin (IL)-17A and ADAM9 in small airways and alveolar walls was measured by immunohistochemistry. Wild-type and Il17a−/− C57BL/6 mice were exposed to CS for six months, and ADAM9 expression in the airway epithelia was measured by immunoreactivity. In addition, the protein and mRNA expression levels of IL-17A and ADAM9 were assessed in CS extract (CSE) and/or IL-17A-treated human bronchial epithelial (HBE) cells.ResultsThe immunoreactivity of ADAM9 was increased in the airway epithelia and alveolar walls of patients with COPD compared to that of the controls. The expression of IL-17A was also upregulated in airway epithelial cells of patients with COPD and correlated positively with the level of ADAM9. The results from the animal model showed that Il17a−/− mice were protected from emphysema induced by CS exposure, together with a reduced level of ADAM9 expression in the airway epithelia, suggesting a possible link between ADAM9 and IL-17A. Consistently, our in vitro cell model showed that CSE stimulated the expression of ADAM9 and IL-17A in HBE cells in a dose- and time-dependent manner. Recombinant IL-17A induced ADAM9 upregulation in HBE cells and had a synergistic effect with CSE, whereas blocking IL-17A inhibited CSE-induced ADAM9 expression. Further analysis revealed that IL-17A induced c-Jun N-terminal kinase (JNK) phosphorylation, thereby increasing ADAM9 expression.ConclusionOur results revealed a novel role of IL-17A in CS-related COPD, where IL-17A contributes to ADAM9 expression by activating JNK signaling.

ADAM17 cleaves the insulin receptor ectodomain on endothelial cells and causes vascular insulin resistance.

Inflammation and vascular insulin resistance are hallmarks of type 2 diabetes (T2D). However, several potential mechanisms causing abnormal endothelial insulin signaling in T2D need further investigation. Evidence indicates that the activity of ADAM17 (a disintegrin and metalloproteinase-17) and the presence of insulin receptor (IR) in plasma are increased in subjects with T2D. Accordingly, we hypothesized that in T2D, increased ADAM17 activity sheds the IR ectodomain from endothelial cells and impairs insulin-induced vasodilation. We used small visceral arteries isolated from a cross-sectional study of subjects with and without T2D undergoing bariatric surgery, human cultured endothelial cells, and recombinant proteins to test our hypothesis. Here, we demonstrate that arteries from subjects with T2D had increased ADAM17 expression, reduced presence of tissue inhibitor of metalloproteinase-3 (TIMP3), decreased extracellular IRα, and impaired insulin-induced vasodilation versus those from subjects without T2D. In vitro, active ADAM17 cleaved the ectodomain of the IRβ subunit. Endothelial cells with ADAM17 overexpression or exposed to the protein kinase-C activator, PMA, had increased ADAM17 activity, decreased IRα presence on the cell surface, and increased IR shedding. Moreover, pharmacological inhibition of ADAM17 with TAPI-0 rescued PMA-induced IR shedding and insulin-signaling impairments in endothelial cells and insulin-stimulated vasodilation in human arteries. In aggregate, our findings suggest that ADAM17-mediated shedding of IR from the endothelial surface impairs insulin-mediated vasodilation. Thus, we propose that inhibition of ADAM17 sheddase activity should be considered a strategy to restore vascular insulin sensitivity in T2D.NEW & NOTEWORTHY To our knowledge, this is the first study to investigate the involvement of ADAM17 in causing impaired insulin-induced vasodilation in T2D. We provide evidence that ADAM17 activity is increased in the vasculature of patients with T2D and support the notion that ADAM17-mediated shedding of endothelial IRα ectodomains is a novel mechanism causing vascular insulin resistance. Our results highlight that targeting ADAM17 activity may be a potential therapeutic strategy to correct vascular insulin resistance in T2D.

Circ_0088194 Regulates Proliferation, Migration, Apoptosis, and Inflammation by miR-30a-3p/ADAM10 Axis in Rheumatoid Arthritis Fibroblastic Synovial Cells.

Dysregulation of circular RNAs (circRNAs) has been observed in multiple diseases including rheumatoid arthritis (RA), and we investigated the role of the circ_0088194/microRNA (miR)-30a-3p/a disintegrin and metalloproteinase 10 (ADAM10) axis in RA. Circ_0088194, miR-30a-3p, and ADAM10 contents in RA tissues and RA-fibroblast-like synoviocytes (RA-FLSs) were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR) and western blot. Cell proliferation, migration, apoptosis, and inflammatory factor secretion of RA-FLSs were detected using 5-ethynyl-2'-deoxyuridine (EdU), wound healing assay, flow cytometry, and enzyme-linked immunosorbent assay (ELISA). Targeting relationship between miR-30a-3p and circ_0088194 or ADAM10 was validated by luciferase reporter system, RNA immunoprecipitation (RIP), and RNA pull-down assays. Circ_0088194 and ADAM10 levels were increased, while miR-30a-3p was decreased in RA tissues and RA-FLSs. Circ_0088194 knockdown suppressed the growth, migration, and inflammation of RA-FLSs, while the upregulation of circ_0088194 showed opposite effects. Circ_0088194 directly targeted miR-30a-3p, ADAM10 was a target of miR-30a-3p, and circ_0088194 regulated the expression of ADAM10 by sponging miR-30a-3p. MiR-30a-3p inhibition restored the inhibition effects of circ_0088194 knockdown or RA-FLSs. Moreover, miR-30a-3p re-expression repressed growth, migration, and inflammatory response in RA-FLSs, which were reversed by ADAM10 overexpression. Circ_0088194 acted on miR-30a-3p/ADAM10 axis to promote the proliferation, migration, and inflammatory response, and inhibit apoptosis in RA-FLSs.

Altered expression of a disintegrin and metalloproteinase 10 in peripheral blood mononuclear cells in type 2 diabetes mellitus patients with the acute coronary syndrome: a pilot study.

Advanced glycation end products (AGEs) are responsible for the complications in type 2 diabetes mellitus (T2DM) patients by acting via its receptor (RAGE). The soluble form of RAGE (sRAGE) prevents the harmful effects of AGE-RAGE signalling. The sRAGE is produced either by alternate splicing (esRAGE) or proteolytic RAGE cleavage by a disintegrin and metalloproteinase 10 (ADAM10). Hence, the study aimed to compare the expression of ADAM10 in peripheral blood mononuclear cell (PBMC), serum sRAGE and esRAGE levels in T2DM patients with and without acute coronary syndrome (ACS). Forty-five T2DM patients with ACS and 45 age, gender and duration of DM-matched T2DM patients without ACS were recruited. Serum sRAGE and esRAGE levels were measured by enzyme-linked immunosorbent assay. The expression of ADAM10 in PBMC was determined by quantitative reverse transcription-polymerase chain reaction. The expression of ADAM10 in PBMC and serum sRAGE levels were significantly lower in T2DM patients with ACS than in T2DM patients without ACS (p < 0.001). Serum sRAGE levels and expression of ADAM10 in PBMC were positively correlated with each other and negatively correlated with markers of cardiac injury and glycaemic status (p < 0.05). Simple logistic regression showed that the models containing the expression of ADAM10 and serum sRAGE level could predict the ACS risk among T2DM patients. ROC analysis showed that both might be used for ACS diagnosis in T2DM patients. Reduced expression of ADAM10 in PBMC might be responsible for lower serum sRAGE levels, predisposing T2DM patients to high ACS risk.

Circ_0005714/miR-223-3p/ADAM9 regulatory axis affects proliferation, migration, invasion, and angiopoiesis in trophoblast cells

Background Circular RNAs (circRNAs) have critical roles in various types of diseases, including preeclampsia (PE). Circ_0005714 function in PE was explored in this study. Methods Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed for level analysis of circ_0005714, micoRNA-223-3p (miR-223-3p), and a disintegrin and metalloproteinase 9 (ADAM9). Cell Counting Kit-8 (CCK-8) and colony formation assays were used for cell viability and colony formation detection. Cell proliferation was determined by EdU assay. The determination of migration and invasion was conducted by wound healing assay and transwell assay. Tube formation assay was applied to assess angiopoiesis. Target binding analysis was performed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Western blot was used for protein examination. Results Circ_0005714 was highly expressed in PE placenta tissues. The expression promotion of circ_0005714 reduced proliferation, migration, invasion, and angiopoiesis in trophoblast cells. Furthermore, circ_0005714 acted as a molecular sponge for miR-223-3p and the effects of circ_0005714 on trophoblast cells were achieved by sponging miR-223-3p. Moreover, miR-223-3p could target ADAM9 and knockdown of ADAM9 reversed cell progression inhibition induced by miR-223-3p inhibitor. In addition, circ_0005714 upregulated the ADAM9 expression and inactivated the Wnt/β-catenin pathway through targeting miR-223-3p. Conclusions All results manifested that circ_0005714 retarded the progression of PE by mediating the miR-223-3p/ADAM9 signal network.

HCMV UL148 and UL148D regulate multiple immune pathways by impairing expression of ADAM17

Human cytomegalovirus (HCMV) is one of the most widespread, highly successful herpesviruses, establishing a life-long viral infection in humans. HCMV has been described as a paradigm of immune evasion able to manipulate many immune functions in the host. Here, we describe a novel, post-translational mechanism in which HCMV downregulates a disintegrin and metalloproteinase 17 (ADAM17), a ‘sheddase’ that cleaves and releases over 80 membrane-anchored cytokines, cell adhesion molecules and other receptors. A screen of HCMV deletion mutants identified UL148 and UL148D as the HCMV genes responsible for ADAM17 downregulation, working synergistically to alter ADAM17 levels in infected cells. We demonstrate that UL148/UL148D interfere with ADAM17 maturation, resulting in expression of only the intracellular immature precursor, and absence of mature ADAM17 on the surface of wildtype HCMV-infected cells. The consequences of ADAM17 downregulation by HCMV were analysed using proteomics and validated using biochemical and flow cytometric techniques, revealing impact on multiple cell surface and secreted host proteins. This included stabilisation of surface TNF Receptor 2, as well as Vasorin and Jagged1, which have recognised roles in Treg development. Other known ADAM17 targets were not stabilised, suggesting specific control by HCMV. Vaccinia virus, another paradigm of immune evasion, also impaired surface ADAM17 expression, suggesting that manipulation of ADAM17 may represent a novel immunoregulatory hub targeted by large DNA viruses.

Downregulation of sperm-associated antigen 5 inhibits melanoma progression by regulating forkhead box protein M1/A disintegrin and metalloproteinase 17/NOTCH1 signaling

ABSTRACT Sperm-associated antigen 5 (SPAG5) has been identified as a driver in several type of cancers. In this study, we aimed to reveal the role of SPAG5 in melanoma and clarify whether FOXM1 (forkhead box protein M1) /ADAM17 (A disintegrin and metalloproteinase 17) /NOTCH1 signaling was involved. The expression of SPAG5 in malignant melanoma (MM) tissues and matched normal tissues was detected using qRT-PCR, immunohistochemistry and Western blotting. Cell viability was tested using CCK-8 (Cell Count Kit-8), colony formation and EdU staining. Cell migration and epithelial to mesenchymal transition (EMT) were measured using transwell chambers and immunofluorescent staining. Cell cycle distribution and tumorigenesis were assessed by flow cytometry and in vivo tumor-bearing experiments, respectively. The results demonstrated that the expression of SPAG5 was increased in MM tissues and cells. Downregulation of SPAG5 inhibited cell viability, migration, invasion and EMT, and induced a G1-phase arrest. In addition, downregulation of SPAG5 decreased the expression of FOXM1, thereafter inhibiting the expression of ADAM17, NOTCH1 and HES1. Furthermore, deletion of SPAG5 expression decreased the tumorigenesis of MM A375 cells. In conclusion, this study demonstrated that SPAG5 was overexpressed in MM. Downregulation of SPAG5 repressed MM cell growth and EMT, which might be induced by inactivation of the FOXM1/ADAM17/NOTCH1 signaling.

Reduced sRAGE Production and ADAM10 Gene Expression in Peripheral Blood Samples of Diabetic Nephropathy Patients

Introduction: Excessive signalling via the Receptor for Advanced Glycation End products (RAGE) is implicated in inflammatory renal damage in Diabetic Nephropathy (DN). RAGE signaling is modulated by its soluble form (sRAGE) that arises due to ectodomain cleavage catalysed by A Disintegrin and Metalloproteinase 10 (ADAM10). The sRAGE functions as a decoy and competes with RAGE for binding to the cognate ligand. Aim: The aim of this study was to evaluate sRAGE and ADAM10 gene levels in peripheral blood samples of Diabetic Nephropathy patients. Materials and Methods: The present observational study was conducted in the Department of General Medicine, RL Jalappa Hospital and Research Centre, Kolar, Karnataka, India, between January 2019 to April 2020. Study comprised of three groups: group 1 of 30 DN patients; group 2 of 28 Type II Diabetis Mellitus (T2DM) patients without microvascular complications and group 3 comprised of 30 healthy volunteers. Blood samples obtained from the study participants were cultured for 24 hours along with insulin treatment or a suitable control. sRAGE levels were measured in the conditioned media by Enzyme Linked Immunosorbent Assay (ELISA) technique. Expression of the ADAM10 gene was measured in the cell pellet by using the quantitative real-time Polymerase Chain Reaction (PCR) technique. Results: A total of 88 subjects were included in the study, with 30 patients in group 1 (DN, mean age 55.34±7.76 years), 28 patients in group 2 (T2DM, mean age: 55.07±7.7 years) and 30 subjects in group 3 (healthy individuals, mean age: 55±8.05 years). sRAGE levels were significantly lower in nephropathy patients when compared to healthy volunteers (p=2.5×10-9). Likewise, ADAM10 expression levels were also significantly lower in nephropathy patients when compared to healthy volunteers (p=1.3×10-4). Insulin treatment led to significantly higher sRAGE production in healthy volunteers as compared to T2DM patients (p-value 3.3×10-11). Insulin treatment leads to significant upregulation of the ADAM10 gene expression in healthy volunteers as compared to DN and T2DM. Conclusion: Abnormal RAGE signaling in DN may arise due to diminished sRAGE production as a consequence of reduced ADAM10 expression.

Interactions of renin-angiotensin system and COVID-19: the importance of daily rhythms in ACE2, ADAM17 and TMPRSS2 expression.

Angiotensin-converting enzyme 2 (ACE2) was identified as a molecule that mediates the cellular entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Several membrane molecules of the host cell must cooperate in this process. While ACE2 serves in a membrane receptor-mediating interaction with the surface spike (S) glycoprotein of SARS-CoV-2 located on the virus envelope, enzyme A disintegrin and metalloproteinase 17 (ADAM17) regulates ACE2 availability on the membrane and transmembrane protease serine 2 (TMPRSS2) facilitates virus-cell membrane fusion. Interestingly, ACE2, ADAM17 and TMPRSS2 show a daily rhythm of expression in at least some mammalian tissue. The circadian system can also modulate COVID-19 progression via circadian control of the immune system (direct, as well as melatonin-mediated) and blood coagulation. Virus/ACE2 interaction causes ACE2 internalization into the cell, which is associated with suppressed activity of ACE2. As a major role of ACE2 is to form vasodilatory angiotensin 1-7 from angiotensin II (Ang II), suppressed ACE2 levels in the lung can contribute to secondary COVID-19 complications caused by up-regulated, pro-inflammatory vasoconstrictor Ang II. This is supported by the positive association of hypertension and negative COVID-19 prognosis although this relationship is dependent on numerous comorbidities. Hypertension treatment with inhibitors of renin-angiotensin system does not negatively influence prognosis of COVID-19 patients. It seems that tissue susceptibility to SARS-CoV-2 shows negative correlation to ACE2 expression. However, in lungs of infected patient, a high ACE2 expression is associated with better outcome, compared to low ACE2 expression. Manipulation of soluble ACE2 levels is a promising COVID-19 therapeutic strategy.

Shikonin suppresses colon cancer cell growth and exerts synergistic effects by regulating ADAM17 and the IL‑6/STAT3 signaling pathway.

Signal transducer and activator of transcription 3 (STAT3) activation is associated with drug resistance induced by anti-epidermal growth factor receptor (anti-EGFR) therapy in the treatment of colon cancer. Thus, the combined inhibition of EGFR and STAT3 may prove beneficial for this type of cancer. STAT3 has been proven to play a critical role in colon cancer initiation and progression, and is considered the primary downstream effector driven by interleukin-6 (IL-6). A disintegrin and metalloproteinase 17 (ADAM17), documented as an oncogene, catalyzes the cleavage of both EGF and IL-6R, inducing EGFR signaling and enabling IL-6 trans-signaling to activate STAT3 in a wide range of cell types to promote inflammation and cancer development. As a natural product, shikonin (SKN) has been found to function as an antitumor agent; however, its role in the regulation of ADAM17 and IL-6/STAT3 signaling in colon cancer cells remains unknown. In the present study, it was found that SKN inhibited colon cancer cell growth, suppressed both constitutive and IL-6-induced STAT3 phosphorylation, and downregulated the expression of ADAM17. ADAM17 expression was not altered in response to STAT3 knockdown, while IL-6-induced STAT3 activation did not induce ADAM17 transcripts. Furthermore, it was demonstrated that SKN did not affect the expression of key proteins involved in the maturation and degradation of ADAM17. SKN decreased ADAM17 expression possibly through reactive oxygen species (ROS)-mediated translational inhibition, as evidenced by the increased ADAM17 mRNA and phosphorylation levels of eukaryotic initiation factor 2α (eIF2α). The expression of ADAM17 and p-eIF2α was reversed by N-acetylcysteine (NAC, a ROS scavenger). Taken together, these results indicate that the concurrent inhibition of ADAM17 and IL-6/STAT3 signaling by SKN may synergistically contribute to the suppression of colon cancer cell growth.