ADAM10 Expression Research Articles

ShRNAs targeting mouse Adam10 diminish cell response to proinflammatory stimuli independently of Adam10 silencing.

ABSTRACTRNA interference is one of the common methods of studying protein functions. In recent years critical reports have emerged indicating that off-target effects may have a much greater impact on RNAi-based analysis than previously assumed. We studied the influence of Adam10 and Adam17 silencing on MC38CEA cell response to proinflammatory stimuli. Eight lentiviral vector-encoded shRNAs that reduced ADAM10 expression, including two that are specific towards ADAM17, caused inhibition of cytokine-induced Nos2 expression presumably via off-target effects. ADAM10 silencing was not responsible for this effect because: (i) CRISPR/Cas9 knockdown of ADAM10 did not affect Nos2 levels; (ii) ADAM10 inhibitor increased rather than decreased Nos2 expression; (iii) overexpression of ADAM10 in the cells with shRNA-silenced Adam10 did not reverse the effect induced by shRNA; (iv) shRNA targeting ADAM10 resulted in decrease of Nos2 expression even in ADAM10-deficient cells. The studied shRNAs influenced transcription of Nos2 rather than stability of Nos2 mRNA. They also affected stimulation of Ccl2 and Ccl7 expression. Additionally, we used vectors with doxycycline-inducible expression of chosen shRNAs and observed reduced activation of NF-κB and, to a lesser extent, AP-1 transcription factors. We discuss the requirements of strict controls and verification of results with complementary methods for reliable conclusions of shRNA-based experiments.

Effects of exogenous progesterone on the expression of mineral regulatory molecules by ovine endometrium and placentomes†.

This study aimed to determine whether the acceleration of conceptus development induced by the administration of exogenous progesterone (P4) during the preimplantation period of pregnancy alters calcium, phosphate, and vitamin D signaling at the maternal-conceptus interface. Suffolk ewes (n = 48) were mated to fertile rams and received daily intramuscular injections of either corn oil (CO) vehicle or 25mg of progesterone in CO (P4) for the first 8days of pregnancy and hysterectomized on either Day 9 (CO, n = 5; P4, n = 6), 12 (CO, n = 9; P4, n = 4) or 125 (CO, n = 14; P4, n = 10) of gestation. The expression of S100A12 (P < 0.05) and fibroblast growth factor receptor (FGFR2) (P < 0.01) messenger RNAs (mRNAs) was lower in endometria from P4-treated ewes on Day 12. The expression of ADAM10 (P < 0.05) mRNA was greater in endometria from P4-treated ewes on Day 125. The expression of ADAM10 (P < 0.01), FGFR2 (P < 0.05), solute carrier (SLC)20A1 (P < 0.05), TRPV5 (P < 0.05), and TRPV6 (P < 0.01) mRNAs was greater, but KL mRNA expression was lower (P < 0.05) in placentomes from P4-treated ewes at Day 125. There was lower endometrial and greater placentomal expression of mRNAs involved in mineral metabolism and transport in twin compared to singleton pregnancies. Further, the expression of mRNAs involved in mineral metabolism and transport was greater in P4-treated twin placentomes. KL, FGF23, vitamin D receptor (VDR), S100A9, S100A12, S100G, and CYP27B1 proteins were immunolocalized in endometria and placentomes. Exogenous P4 in early pregnancy altered the expression of regulators of calcium, phosphate, and vitamin D on Day 125 of pregnancy indicating a novel effect of P4 on mineral transport at the maternal-conceptus interface.

MICA/B-targeted antibody promotes NK cell–driven tumor immunity in patients with intrahepatic cholangiocarcinoma

ABSTRACT The major histocompatibility complex-class I chain related proteins A and B (MICA/B) is upregulated because of cellular stress and MICA/B shedding by cancer cells causes escape from NKG2D recognition favoring the emergence of cancers. Cholangiocarcinoma (CCA) is a relatively rare, though increasingly prevalent, primary liver cancer characterized by a late clinical presentation and a dismal prognosis. We explored the NKG2D-MICA/B axis in NK cells from 41 patients with intrahepatic cholangiocarcinoma (iCCA). The MICA/B-specific 7C6 mAb was used for ex vivo antibody-dependent cytotoxicity (ADCC) experiments using circulating, non tumor liver- and tumor-infiltrating NK cells against the HuCCT-1 cell line and patient-derived primary iCCA cells as targets. MICA/B were more expressed in iCCA than in non-tumoral tissue, MICA transcription being higher in moderately-differentiated compared with poorly-differentiated cancer. Serum MICA was elevated in iCCA patients in line with higher expression of ADAM10 and ADAM17 that are responsible for proteolytic release of MICA/B from tumor. Addition of 7C6 significantly boosted peripheral, liver- and tumor-infiltrating-NK cell degranulation and IFNγ production toward MICA/B-expressing established cell lines and autologous iCCA patient target cells. Our data show that anti-MICA/B drives NK cell anti-tumor activity, and provide preclinical evidence in support of 7C6 as a potential immunotherapeutic tool for iCCA.

The role of S100B/RAGE-enhanced ADAM17 activation in endothelial glycocalyx shedding after traumatic brain injury

BackgroundTraumatic brain injury (TBI) remains one of the main causes for disability and death worldwide. While the primary mechanical injury cannot be avoided, the prevention of secondary injury is the focus of TBI research. Present study aimed to elucidate the effects and mechanisms of S100B and its receptor RAGE on mediating secondary injury after TBI.MethodsThis study established TBI animal model by fluid percussion injury in rats, cell model by stretch-injured in astrocytes, and endothelial injury model with conditioned medium stimulation. Pharmacological intervention was applied to interfere the activities of S100B/RAGE/ADAM17 signaling pathway, respectively. The expressions or contents of S100B, RAGE, syndecan-1 and ADAM17 in brain and serum, as well as in cultured cells and medium, were detected by western blot. The distribution of relative molecules was observed with immunofluorescence.ResultsWe found that TBI could activate the release of S100B, mostly from astrocytes, and S100B and RAGE could mutually regulate their expression and activation. Most importantly, present study revealed an obvious increase of syndecan-1 in rat serum or in endothelial cultured medium after injury, and a significant decrease in tissue and in cultured endothelial cells, indicating TBI-induced shedding of endothelial glycocalyx. The data further proved that the activation of S100B/RAGE signaling could promote the shedding of endothelial glycocalyx by enhancing the expression, translocation and activity of ADAM17, an important sheddase, in endothelial cells. The damage of endothelial glycocalyx consequently aggravated blood brain barrier (BBB) dysfunction and systemic vascular hyper-permeability, overall resulting in secondary brain and lung injury.ConclusionsTBI triggers the activation of S100B/RAGE signal pathway. The regulation S100B/RAGE on ADAM17 expression, translocation and activation further promotes the shedding of endothelial glycocalyx, aggravates the dysfunction of BBB, and increases the vascular permeability, leading to secondary brain and lung injury. Present study may open a new corridor for the more in-depth understanding of the molecular processes responsible for cerebral and systemic vascular barrier impairment and secondary injury after TBI.

Effect of circ-SFMBT2 on the biological behavior of non-small cell lung cancer cells by targeting the miR-7-5p/ADAM10 axis

To explore the effect of circ-SFMBT2 on the biological behavior of non-small cell lung cancer (NSCLC) cells and its regulatory role on the miR-7-5p/ADAM10 axis. qRT-PCR and Western blotting were used to determine the expression of circ-SFMBT2, miR-7-5p, and ADAM10 in NSCLC tissues and adjacent tissues. Pearson analysis was used to analyze the correlation between circ-SFMBT2 and miR-7-5p, and between miR-7-5p and ADAM10. In vitro cultured human bronchial epithelial-like cells (HBE) and lung cancer cell lines H1650, H460, A549, H1299. CCK-8 and EdU methods were used to assess the ability of cell proliferation. Plate experiment was used to detect the clone formation ability. Flow cytometry was used to detect the apoptosis rate. Transwell experiment was used to detect cell invasion ability. Dual luciferase reporter experiment detects the targeting relationship between circ-SFMBT2 and miR-7-5p, and between miR-7-5p and ADAM10. Transplanted tumor experiment in nude mice assessed the effect of knocking down circ-SFMBT2 on the growth of transplanted tumor. Immunohistochemical experiments were performed to detect the positive rates of ADAM10 and Ki67 proteins in transplanted tumor tissues. The expression levels of circ-SFMBT2 and ADAM10 were increased in NSCLC tissues and cell lines, while decreased the expression of miR-7-5p. circ-SFMBT2 was negatively correlated with miR-7-5p, while miR-7-5p was negatively correlated with ADAM10. Silencing the overexpression of circ-SFMBT2 and miR-7-5p could inhibit cell proliferation, clone formation and invasion, and also promote apoptosis. circ-SFMBT2 could target miR-7-5p, and ADAM10 was the target gene of miR-7-5p. The combined effect of silencing circ-SFMBT2 and inhibition of miR-7-5p, as well as miR-7-5p overexpression and ADAM10 overexpression could promote cell proliferation, clone formation and invasion, and also suppress cell apoptosis. Silencing circ-SFMBT2 could inhibit the growth of transplanted tumors. Silencing circ-SFMBT2 can suppress the proliferation, clone formation, invasion ability and induce apoptosis of NSCLC cells by regulating the miR-7-5p/ADAM10 axis.

A positive allosteric modulator for the muscarinic receptor (M1 mAChR) improves pathology and cognitive deficits in female APPswe/PSEN1ΔE9 mice.

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive decline, and women account for 60% of diagnosed cases. β-Amyloid (Aβ) oligomers are considered the principal neurotoxic species in AD brains. The M1 muscarinic ACh receptor (M1 mAChR) plays a key role in memory and learning. M1 mAChR agonists show pro-cognitive activity but cause many adverse off-target effects. A new orally bioavailable M1 mAChR positive allosteric modulator (PAM), VU0486846, is devoid of direct agonist activity or adverse effects but was not tested for disease-modifying efficacy in female AD mice. Nine-month-old female APPswe/PSEN1ΔE9 (APPswe) and wildtype mice were treated with VU0486846 in drinking water (10 mg·kg-1 ·day-1 ) for 4 or 8 weeks. Cognitive function of mice was assessed after treatment, and brains were harvested for biochemical and immunohistochemical assessment. VU0486846 improved cognitive function of APPswe mice when tested in novel object recognition and Morris water maze. This was paralleled by a significant reduction in Aβ oligomers and plaques and neuronal loss in the hippocampus. VU0486846 reduced Aβ oligomer production in APPswe mice by increasing M1 mAChR expression and shifting the processing of amyloid precursor protein from amyloidogenic cleavage to non-amyloidogenic cleavage. Specifically, VU0486846 reduced the expression of β-secretase 1 (BACE1), whereas it enhanced the expression of the α-secretase ADAM10 in APPswe hippocampus. Using M1 mAChR PAMs can be a viable disease-modifying approach that should be exploited clinically to slow AD in women.

High Glucose Impairs Expression and Activation of MerTK in ARPE-19 Cells.

MerTK (Mer Tyrosine Kinase) is a cell surface receptor that regulates phagocytosis of photoreceptor outer segments (POS) in retinal pigment epithelial (RPE) cells. POS phagocytosis is impaired in several pathologies, including diabetes. In this study, we investigate whether hyperglycemic conditions may affect MerTK expression and activation in ARPE-19 cells, a retinal pigment epithelial cellular model. ARPE-19 cells were cultured in standard (CTR) or high-glucose (HG) medium for 24 h. Then, we analyzed: mRNA levels and protein expression of MerTK and ADAM9, a protease that cleaves the extracellular region of MerTK; the amount of cleaved Mer (sMer); and the ability of GAS6, a MerTK ligand, to induce MerTK phosphorylation. Since HG reduces miR-126 levels, and ADAM9 is a target of miR-126, ARPE-19 cells were transfected with miR-126 inhibitor or mimic; then, we evaluated ADAM9 expression, sMer, and POS phagocytosis. We found that HG reduced expression and activation of MerTK. Contextually, HG increased expression of ADAM9 and the amount of sMer. Overexpression of miR-126 reduced levels of sMer and improved phagocytosis in ARPE-19 cells cultured with HG. In this study, we demonstrate that HG compromises MerTK expression and activation in ARPE-19 cells. Our results suggest that HG up-regulates ADAM9 expression, leading to increased shedding of MerTK. The consequent rise in sMer coupled to reduced expression of MerTK impairs binding and internalization of POS in ARPE-19 cells.

MiR-557 downregulation lowered cell proliferation and malignancy in glioblastoma by targeting ADAM17

&#x0D; &#x0D; &#x0D; &#x0D; Purpose: To examine the role of miR-557 in the pathogenesis and development of glioblastoma (GBM) and its potential regulatory mechanism.&#x0D; Methods: Dysregulation of miR-557 in GBM cells was determined using quantitative (real-time) PCR (qPCR). Cell proliferative ability, migratory activity and invasive ability were measured using the MTT colorimetric assay, wound healing assay and Transwell chambers assay. The direct target mRNA of miR-557 was predicted, and further validated using TargetScan and luciferase assay, respectively.&#x0D; Results: Compared with human astrocytes (HAs), the downregulation of miR-557 was observed in human GBM cell lines. In U-251MG and A172 cells that overexpressed miR-557 mimics, the level of proliferation was significantly reduced, the wound width was larger, and the number of invaded cells wan decreased than that of NC mimics. Predictive results from TargetScan and results of luciferase assay demonstrated that miR-557 directly targets the 3’-untranslated region (3’-UTR) of ADAM17. In A172 cells and U-251MG cells, the upregulation E-cadherin (E-cad) and the downregulation of N- cadherin (N-cad) and vimentin (Vim) were caused by miR-557 mimics as compared with NC mimics. Expression of ADAM17, NICD, HES1, and EGFR was downregulated by miR-557 mimics and upregulated by miR-557 inhibitors in A172 cells and U-251MG cells.&#x0D; Conclusion: Downregulation of miR-557 accelerates GBM cell growth and malignancy by directly targeting ADAM17 3’-UTR, providing a prognostic and potential therapeutic factor for new drug discovery in GBM.&#x0D; &#x0D; &#x0D; &#x0D;

Expression of ADAM12 in Gastric Cancer and its Relation to Tumor Cell Behavior and Prognosis.

A disintegrin and metalloprotease (ADAM) 12 expression has been found up-regulated in various cancer types. The aim of the study was to evaluate whether ADAM12 affects oncogenic behavior of gastric cancer (GC) cells and investigate its prognostic value. The effect of ADAM12 on tumor cell behavior was examined using the small interfering RNA and pcDNA6-myc vector in human GC cell lines. Expression of ADAM12 in GC tissues was confirmed by immunohistochemistry. Apoptosis and proliferation were determined by a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and immunohistochemical staining for Ki-67. ADAM12 overexpression enhanced tumor cell migration and invasion in AGS and SNU638 cells. Down-regulation of caspase-3 and PARP activity due to ADAM12 overexpression enhanced tumor cell proliferation and inhibited apoptosis. The expression of Snail and Vimentin increased and that of E-cadherin decreased following ADAM12 overexpression. In contrast, ADAM12 knockdown reversed these effects. ADAM12 overexpression increased the phosphorylation of Akt and GSK-3β. The mean Ki-67 labeling index value of ADAM12-positive tumors was significantly higher compared to that of ADAM12-negative tumors. ADAM12 expression was associated with age, tumor size, cancer stage, depth of invasion, lymph node metastasis, and poor survival. ADAM12 enhances tumor progression by increasing cell mobility, enhancing cell proliferation, and inhibiting apoptosis in GC cells. Also, ADAM12 is associated with adverse clinicopathological features and poor survival. It may be used as a molecular marker for the prediction of clinical outcomes of patients with GC.

MiR-140-3p enhances the sensitivity of LUAD cells to antitumor agents by targeting the ADAM10/Notch pathway.

Background: The Notch pathway, which is related to the drug-resistance of lung adenocarcinoma (LUAD) type of non-small cell lung cancer (NSCLC) cells, is activated by cleavage of Notch proteins mediated by ADAMs, ADAM10 or ADAM17. Methods: In the present study, our results demonstrated that of these two ADAMs, the expression of ADAM10 in clinical samples of the LUAD type of NSCLC was much higher than that of ADAM17, while miR-140-3p - an miRNA that could target ADAM10 - was identified by an online tool: miRDB (miRNA database). The detail function and mechanism of miR-140-3p in regulating the sensitivity of NSCLC cells to antitumor drugs was systematically explored in vitro and in vivo. Results: In A549, a typical NSCLC LUAD cell line, miR-140-3p decreased ADAM10 expression and repressed activation of the Notch pathway by repressing cleavage of Notch proteins. The expression of miR-140-3p was negatively related to ADAM10 in clinical specimens. Nucleocytoplasmic separation/subfraction assays showed that miR-140-3p was able to inhibit the cleavage of Notch protein, and led to the accumulation of Notch intracellular domains (NICD) in the nucleus. Overexpression of miR-140-3p enhanced the sensitivity of A549 cells to antitumor agents by targeting the 3'UTR region of ADAM10 mRNA in both cultured cells and in vivo models. Conclusion: ADAM10 plays a major role in LUAD, and miR-140-3p acts on ADAM10 and inhibits its expression and the cleavage of Notch protein, leading to the inhibition the activity of the Notch pathway, and ultimately upregulating LUAD cell sensitivity to anti- tumor drugs.

Decreased Expression of ADAM10 on Monocytes is Associated with Chronic Allograft Dysfunction in Kidney Transplant Recipients

Decreased Expression of ADAM10 on Monocytes is Associated with Chronic Allograft Dysfunction in Kidney Transplant Recipients

Circ_0001665 Contributes to the Occurrence of Vestibular Schwannoma via Targeting miR-302a-3p/Adam9/EGFR Signaling Pathway

Vestibular schwannoma (VS) is a benign, slow-growing neoplasm, which is an important cause of sensorineural hearing loss. Circular RNAs (circRNAs) have been widely reported to be dysregulated and participate in multiple biological processes of human diseases. However, roles of most circRNAs still remain explored. In the present study, the main aim was to uncover the impacts of circ_0001665, a cricRNA derived from ADAM metallopeptidase domain 9 (Adam9), on the biological behaviors of VS cells. Firstly, RT-qPCR was done to analyze circ_0001665 expression in VS cells and it was suggested that circ_001665 was distinctly up-regulated in rat VS cells. Supported by western blot analysis, circ_0001665 inhibition was validated to impede the proliferation while inducing the apoptosis of VS cells via functional assays. Additionally, results of mechanism assays demonstrated that circ_0001665 could function as a sponge of microRNA-302a-3p (miR-302a-3p) to enhance Adam9 expression and to activate EGFR signaling pathway in VS cells. Eventually, it was indicated in rescue assays that circ_0001665 expedited proliferation and restrained apoptosis of VS cells via modulation on miR-302a-3p/Adam9. Collectively, our study identified a novel perspective for exploration into molecular mechanisms in VS.

Expression of Immune Checkpoints in Malignant Tumors: Therapy Targets and Biomarkers for the Gastric Cancer Prognosis.

To increase the effectiveness of anticancer therapy based on immune checkpoint (IC) inhibition, some ICs are being investigated in addition to those used in clinic. We reviewed data on the relationship between PD-L1, B7-H3, B7-H4, IDO1, Galectin-3 and -9, CEACAM1, CD155, Siglec-15 and ADAM17 expression with cancer development in complex with the results of clinical trials on their inhibition. Increased expression of the most studied ICs—PD-L1, B7-H3, and B7-H4—is associated with poor survival; their inhibition is clinically significant. Expression of IDO1, CD155, and ADAM17 is also associated with poor survival, including gastric cancer (GC). The available data indicate that CD155 and ADAM17 are promising targets for immune therapy. However, the clinical trials of anti-IDO1 antibodies have been unsatisfactory. Expression of Galectin-3 and -9, CEACAM1 and Siglec-15 demonstrates a contradictory relationship with patient survival. The lack of satisfactory results of these IC inhibitor clinical trials additionally indicates the complex nature of their functioning. In conclusion, in many cases it is important to analyze the expression of other participants of the immune response besides target IC. The PD-L1, B7-H3, B7-H4, IDO1 and ADAM17 may be considered as candidates for prognosis markers for GC patient survival.

Simvastatin mitigates streptozotocin-induced type 1 diabetes in mice through downregulation of ADAM10 and ADAM17

BackgroundT cell mediates immune response in type 1 diabetes mellitus (T1DM) through its trafficking into pancreatic islets. The role of A Disintigrin And Metalloproteinase 10 (ADAM10) and 17 (ADAM17) in pancreatic T-cells recruitment into the pancreatic islets during T1DM is not known. AimExplore the role of ADAM10 and ADAM17 in the processing of CXCL16 in T1DM and possible protective effect of simvastatin (SIM) in streptozotocin (STZ)-induced T1DM. Main methodsBalb/c mice were classified into 4 groups, 10 each. Control group received buffer while SIM group received 50 mg/kg, i.p daily for 12 days starting from day 4 of the experiment. Diabetic group; received STZ (55 mg/kg, i.p.) for 5 consecutive days starting from day 1 of the experiment. SIM + STZ group; received SIM (50 mg/kg, i.p.) daily for 12 days and STZ (55 mg/kg, i.p.) for 5 consecutive days. Biochemical, inflammatory and apoptotic markers as well as expression of CXCL16, ADAM10, NF-κB and pancreatic T-cells expression were analyzed. Key findingsSignificant increase in biochemical, inflammatory, apoptotic parameters, expression of ADAM10, ADAM17, CXCL16, NF-κB, and infiltrated T-cells to the pancreatic islets were found in STZ group. SIM treatment in the presence of STZ improved biochemical and inflammatory parameters as well as it reduced the expression of CXCL16, ADAM10, ADAM17, NF-κΒ, T-cells migration and apoptosis in the pancreatic islets. SignificanceSIM mitigated pancreatic β-cell death induced by STZ through down regulation of ADAM10, ADAM17and CXCL16. Therefore, ADAM10/ADAM17 and CXCL16 may serve as novel therapeutic targets for T1DM.

Inflammatory activation of surface molecule shedding by upregulation of the pseudoprotease iRhom2 in colon epithelial cells

The metalloproteinase ADAM17 contributes to inflammatory and proliferative responses by shedding of cell-surface molecules. By this ADAM17 is implicated in inflammation, regeneration, and permeability regulation of epithelial cells in the colon. ADAM17 maturation and surface expression requires the adapter proteins iRhom1 or iRhom2. Here we report that expression of iRhom2 but not iRhom1 is upregulated in intestinal tissue of mice with acute colitis. Our analysis of public databases indicates elevated iRhom2 expression in mucosal tissue and epithelial cells from patients with inflammatory bowel disease (IBD). Consistently, expression of iRhom2 but not iRhom1 is upregulated in colon or intestinal epithelial cell lines after co-stimulation with tumor necrosis factor (TNF) and interferon gamma (IFNgamma). This upregulation can be reduced by inhibition of Janus kinases or transcription factors NF-kappaB or AP-1. Upregulation of iRhom2 can be mimicked by iRhom2 overexpression and is associated with enhanced maturation and surface expression of ADAM17 which then results in increased cleavage of transforming growth factor (TGF) alpha and junctional adhesion molecule (JAM)-A. Finally, the induction of these responses is suppressed by inhibition of iRhom2 transcription. Thus, inflammatory induction of iRhom2 may contribute to upregulated ADAM17-dependent mediator and adhesion molecule release in IBD. The development of iRhom2-dependent inhibitors may allow selective targeting of inflammatory ADAM17 activities.

The −172 A-to-G variation in ADAM17 gene promoter region affects EGR1/ADAM17 pathway and confers susceptibility to septic mortality with sepsis-3.0 criteria

BackgroundA disintegrin and metalloproteinase 17 (ADAM17) is a proteolytic cleaving protein with a crucial function in the inflammatory responses, especially sepsis. But the clear role of ADAM17 in sepsis and the underlying mechanism remained unknown. In this study, we aim to determine the clinical association of ADAM17 −172A > G (rs12692386) promoter polymorphism with sepsis and to further explore the effect and mechanism of the early growth response 1 (EGR1)/ADAM17 pathway in inflammatory process during sepsis. MethodsA total of 477 sepsis patients and 750 controls were enrolled in this study to determine the association of ADAM17 −172A > G polymorphism with sepsis. The transcription factor binding to the promoter region of ADAM17 gene was predicted by bioinformatics analysis and verified by Chromatin Immunoprecipitation (ChIP) and luciferase assays. Quantitative real-time PCR and Western blot were performed to detect EGR1 and ADAM17 expression. Cytokine production was detected by enzyme-linked immunosorbent assay. The effect of EGR1/ADAM17 pathway on sepsis-induced inflammatory responses was evaluated in EGR1-silenced cells and endotoxemia mouse model. ResultsThe frequencies of non-survivors among the sepsis patients with the −172AG/GG genotypes and G allele were distinctly higher than those among patients with the AA genotype (53.9% vs. 39.7%, OR = 1.779, 95% CI = 1.119–2.829, P = 0.0142) and A allele (30.9% vs. 22.2%, OR = 1.570, 95% CI = 1.095–2.251, P = 0.0136). The Kaplan-Meier survival analysis indicated that the 28-day survival in septic patients with −172AG/GG genotypes of this functional ADAM17 promoter polymorphism was much worse than in the AA genotype carriers (log-rank = 5.358, P = 0.021). The results of in vitro lipopolysaccharide-stimulated and luciferase assays indicated that the −172 A-to-G variation could functionally upregulate promoter activity and transcription of ADAM17 gene via enhancing the binding affinity of its promoter region with the EGR1. The ChIP assay identified the direct interaction. Further studies demonstrated that inhibition of EGR1 significantly decreased ADAM17 expression and the pro-inflammatory cytokine secretion in vitro, and improved the survival and inflammatory response of sepsis mouse model. ConclusionsThese results provided evidence that the ADAM17 −172A > G polymorphism functionally promoted ADAM17 expression and enhanced sepsis-induced inflammatory responses via the EGR1/ADAM17 pathway, which ultimately conferred susceptibility to sepsis mortality and poor prognosis.

Vitamin D3 Prevents the Deleterious Effects of Testicular Torsion on Testis by Targeting miRNA-145 and ADAM17: In Silico and In Vivo Study.

Testicular torsion (TT) is the most common urological emergency in children and young adults that can lead to infertility in many cases. The ischemia-reperfusion (IR) injury due to TT has been implicated in the pathogenesis of testicular damage. The main pathological mechanisms of contralateral injury after ipsilateral TT are not fully understood. In the presented study, we investigated the molecular and microscopic basis of ipsilateral and contralateral testicular injury following ipsilateral testicular torsion detorsion (T/D) and explored the possible protective role of vitamin D3. The biochemical analysis indicated that IR injury following T/D significantly decreased the activity of testicular glutathione peroxidase (GPx) enzyme, level of serum testosterone, serum inhibin B, and expression of testicular miRNA145, while increased the activity of testicular myeloperoxidase (MPO) enzyme, level of testicular malondialdehyde (MDA), level of serum antisperm-antibody (AsAb), and expression of ADAM-17. The histological and semen analysis revealed that torsion of the testis caused damages on different tissues in testis. Interestingly, administration of vitamin D3 prior to the IR injury reversed the deterioration effect of IR injury on the testicular tissues as indicated by biochemical and histological analysis which revealed normal appearance of the seminiferous tubules with an apparent decrease in collagen fiber deposition in both ipsilateral and contralateral testes. Our results revealed that the protective effect of vitamin D3 treatment could be attributed to target miRNA145 and ADAM17 protein. To further investigate these findings, we performed a detailed molecular modelling study in order to explore the binding affinity of vitamin D3 toward ADAM17 protein. Our results revealed that vitamin D3 has the ability to bind to the active site of ADAM17 protein via a set of hydrophobic and hydrophilic interactions with high docking score. In conclusion, this study highlights the protective pharmacological application of vitamin D3 to ameliorate the damages of testicular T/D on the testicular tissues via targeting miRNA145 and ADAM17 protein.

Aluminum inhibits non-amyloid pathways via retinoic acid receptor

BackgroundAluminium neurotoxicity has been widely confirmed and mainly manifests as cognitive impairment. Al3+ can inhibit the expression of ADAM10, a key enzyme of the nonamyloid pathway, but its mechanism of toxicity has not been fully elucidated. Studies have shown that RARs can regulate ADAM10 expression. MethodsWe explored whether Al3+ affects the expression of ADAM10 through RARs, thereby affecting the nonamyloid pathway. ResultsAl3+ reduced the expressions of RARα, RARβ and ADAM10. The expression levels of the RARα, RARβ and ADAM10 proteins were upregulated in the RA group compared with the control group. In the RA + 200 μmol Al(mal)3 group, the downregulation of RARα, RARβ and ADAM10 was weaker than that of the 200 μmol Al(mal)3 group, which indicated that RA participated in and upregulated the expression of ADAM10 through RARα and RARβ. ConclusionAl3+ inhibits ADAM10 expression through RARα and RARβ and results in a decrease in the nonamyloid pathway.

Abstract 13466: In Experimental Pad miR29a Modulates Perfusion Recovery and ADAM12 Expression Through Direct Interaction With ADAM12 mRNA

Peripheral artery disease (PAD) is caused by atherosclerotic occlusion of vessels outside the heart and most commonly affects vessels of the lower extremities. Angiogenesis is a part of the post ischemic adaption involved in restoring blood flow in PAD. Previously, in a murine hind limb ischemia (HLI) model of PAD, we identified ADAM12 as a key genetic modifier of post-ischemic perfusion recovery. However, less is known about ADAM12 regulation in ischemia. MiRNAs are a class of small, non-coding, single-stranded RNAs that regulate gene expression primarily through transcriptional repression of mRNA. We showed miR29a modulates ADAM12 expression in the setting of type 1 DM and ischemia. However, how miR29a modulates ADAM12 was not known. Moreover, the physiological effects of miR29a modulation in a non-diabetic setting was not known. Here, we demonstrate that AAV-mediated ectopic overexpression of miR29a in ischemic mouse hind limbs impairs post ischemic perfusion recovery and angiogenesis. We further demonstrate that miR29a regulates ADAM12 through direct interaction with ADAM12 mRNA. Treatment of ischemic mouse hind limbs with AAV9 particles containing miR29a (pAV-miR29a) increased miR29a expression (pAV-control vs pAV-miR29a: 3.22 ± 0.36, vs 1.0 ± 0.09, p&lt;0.05, n=5-6,) and decreased ADAM12 mRNA expression (1.0 ± 0.31 vs 0.30 ± 0.08, p&lt;0.05, n=7-10) resulting in decreased angiogenesis (1.0 ± 0.07 vs 0.66 ± 0.04, p&lt;0.05, n=5), and impairment perfusion (week 3 post HLI perfusion, 101.9±5.55 vs 66.13±12.39, p&lt;0.05, n=5-6,).AGO2 miRNA/RNA-immunoprecipitation studies showed levels of miR29a and ADAM12 mRNA in the complex decreased in samples treated with antagomiR29a (4, 40, 400nM) in a dose dependent manner (miR29a: 0.87, 0.68, 0.44, and ADAM12: 0.89, 0.78, 0.67, fold) but was unchanged by control antagomir (miR29a: 0.84, 0.84, 0.87, fold, and ADAM12: 1.11, 1.12, 1.10, fold). Taken together the data shows miR29a suppresses ADAM12 expression by directly binding to its mRNA resulting in impaired angiogenesis and poor perfusion. Hence, elevated levels of miR29a as seen in diabetes likely contributes to vascular pathology and lowering miR29a could be a therapeutic target.

Regulation of osteoarthritis development by ADAM17/Tace in articular cartilage.

A disintegrin and metalloproteinase 17 (Adam17), also known as TNFα-converting enzyme (Tace), is a membrane-anchored protein involved in shedding of TNF, IL-6 receptor, ligands of epidermal growth factor receptor (EGFR), and Notch receptor. This study aimed to examine the role of Adam17 in adult articular cartilage and osteoarthritis (OA) pathophysiology. Adam17 expression was examined in mouse knee joints during OA development. We analyzed OA development in tamoxifen-inducible chondrocyte-specific Adam17 knockout mice of a resection of the medial meniscus and medial collateral ligament (medial) model, destabilization of the medial meniscus (DMM) model, and aging model. We analyzed downstream pathways by in vitro experiments, and further performed intra-articular administration of an Adam17 inhibitor TAPI-0 for surgically induced mouse OA. Adam17 expression in mouse articular cartilage was increased by OA progression. In all models, Adam17 knockout mice showed ameliorated progression of articular cartilage degradation. Adam17 knockout decreased matrix metallopeptidase 13 (Mmp13) expression in both in vivo and in vitro experiments, whereas Adam17 activation by phorbol-12-myristate-13-acetate (PMA) increased Mmp13 and decreased aggrecan in mouse primary chondrocytes. Adam17 activation enhanced release of soluble TNF and transforming growth factor alpha, a representative EGF ligand, from mouse primary chondrocytes, while it did not change release of soluble IL-6 receptor or nuclear translocation of Notch1 intercellular domain. Intra-articular administration of the Adam17 inhibitor ameliorated OA progression. This study demonstrates regulation of OA development by Adam17, involvement of EGFR and TNF pathways, and the possibility of Adam17 as a therapeutic target for OA.