Circ_0104652 Promotes the Proliferation and Migration of ox-LDL-Stimulated Vascular Smooth Muscle Cells via Stabilizing ADAMTS7 and HMGB1.

BACKGROUND: Atherosclerosis (AS) stands as the primary contributor to cardiovascular disease, a pervasive global health concern. Extensive research has underscored the pivotal role of circular RNAs (circRNAs) in cardiovascular disease development. However, the specific functions of numerous circRNAs in AS remain poorly understood. METHODS: Quantitative real-time PCR analysis revealed a significant upregulation of circ_0104652 in oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs). Loss-of-function experiments were subsequently employed to assess the impact of circ_0104652 on ox-LDL-induced VSMCs. RESULTS: Silencing circ_0104652 was found to impede the proliferation and migration while promoting the apoptosis of ox-LDL-stimulated VSMCs. Mechanistic assays unveiled that circ_0104652 stabilized ADAM metallopeptidase with thrombospondin type 1 motif 7 (ADAMTS7) and high mobility group box 1 (HMGB1) by recruiting eukaryotic translation initiation factor 4A3 (EIF4A3) protein. Rescue assays further confirmed that circ_0104652 exerted its influence on ox-LDL-induced VSMC proliferation through modulation of ADAMTS7 and HMGB1. CONCLUSIONS: This study elucidates the role of the circ_0104652/EIF4A3/ADAMTS7/HMGB1 axis in ox-LDL-stimulated VSMCs, providing valuable insights into the intricate mechanisms involved.

Diagnostic value of serum COMP and ADAMTS7 for intervertebral disc degeneration.

OBJECTIVE: Intervertebral disc degeneration (IVDD) is a major cause of morbidity and disability. Our study aimed to investigate the potential of cartilage oligomeric matrix protein (COMP) and ADAMTS7 (A disintegrin and metalloproteinases with thrombospondin motifs 7) as biomarkers for IVDD together with their functional relationship. METHODS: IVD tissues and peripheral blood samples were collected from IVDD rabbit models over 1-4 weeks. Tissues and blood samples were also collected from clinical patients those were stratified into four equal groups according to Pfirrmann IVDD grading (I-V) with baseline data collected for each participant. COMP and ADAMTS7 expression were analyzed and biomarker characteristics were assessed using linear regression and receiver operating curve (ROC) analyses. RESULTS: COMP and ADAMTS7 expression increased in tissues and serum during IVDD progression. Serum COMP (sCOMP) and serum ADAMTS7 (sADAMTS7) levels increased in a time-dependent manner following IVD damage in the rabbit model while significant positive correlations were detected between sCOMP and sADAMTS7 and Pfirrmann grade in human subjects. ROC analysis showed that combining sCOMP and sADAMTS7 assay results produced an improved diagnostic measure for IVDD compared to individual sCOMP or sADAMTS7 tests. In vitro assays conducted on human cell isolates revealed that COMP prevented extracellular matrix degradation and antagonized ADAMTS7 expression although this protective role was uncoupled under microenvironmental conditions mimicking IVDD. CONCLUSIONS: Increases in circulating COMP and ADAMTS7 correlate with IVDD progression and may play regulatory roles. Assays for sCOMP and/or sADAMTS7 levels can discriminate between healthy subjects and IVDD patients, warranting further clinical assessment.

The Association of ADAMTS7 Gene Polymorphisms with the Risk of Coronary Artery Disease Occurrence and Cardiovascular Survival in the Polish Population: A Case-Control and a Prospective Cohort Study.

The aim of this study was to investigate whether the polymorphisms of the ADAMTS7 gene affect the risk of occurrence and mortality due to CAD. The study group included 231 patients diagnosed with CAD and 240 control blood donors. The genotyping of specified polymorphisms, i.e., rs1994016, rs3825807, and rs7173743, was performed using the TaqMan-PCR. We found that the C allele carriers of the rs1994016 and A allele carriers of the rs3825807 polymorphisms increased the risk of CAD, respectively: OR = 1.72, p = 0.036; OR = 1.64, p = 0.04. Moreover, we studied the biological interactions of specified variants, i.e., rs3825807, rs1994016, and rs7173743, and previously approved risk factors of CAD. We demonstrated here that selected polymorphisms of ADAMTS7 increased the risk of CAD altogether with abnormalities of total cholesterol and LDL concentrations in serum. Although survival analyses did not reveal statistical significance, we observed a trend for the AA genotype of the rs3825807 ADAMTS7, which may predispose to death due to CAD in a 5-year follow-up. In conclusion, the ADAMTS7 polymorphisms investigated in this study may increase the risk of occurrence and/or death due to CAD in the Polish population.

ADAMTS7: a Novel Therapeutic Target in Atherosclerosis.

PURPOSE OF REVIEW: Genome-wide association studies have repeatedly linked the metalloproteinase ADAMTS7 to coronary artery disease. Here we aim to highlight recent findings surrounding the human genetics of ADAMTS7, novel mouse models that investigate ADAMTS7 function, and potential substrates of ADAMTS7 cleavage. RECENT FINDINGS: Recent genome-wide association studies in coronary artery disease have replicated the GWAS signal for ADAMTS7 and shown that the signal holds true even across different ethnic groups. However, the direction of effect in humans remains unclear. A recent novel mouse model revealed that the proatherogenicity of ADAMTS7 is derived from its catalytic functions, while at the translational level, vaccinating mice against ADAMTS7 reduced atherosclerosis. Finally, in vitro proteomics approaches have identified extracellular matrix proteins as candidate substrates that may be causal for the proatherogenicity of ADAMTS7. ADAMTS7 represents an enticing target for therapeutic intervention. The recent studies highlighted here have replicated prior findings, confirming the genetic link between ADAMTS7 and atherosclerosis, while providing further evidence in mice that ADAMTS7 is a targetable proatherogenic enzyme.

Evaluation of subclinical atherosclerosis in obese patients with three noninvasive methods: Arterial stiffness, carotid intima-media thickness, and biomarkers of endothelial dysfunction.

Objective: In this study, we aimed to evaluate subclinical atherosclerosis in patients with obesity who had cardiovascular disease risk indicators such as arterial stiffness, which is evaluated using pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and biomarkers of endothelial dysfunction such as endocan, ADAMTS97, and ADAMTS9. Subjects and methods: Sixty obese subjects, including 23 subjects with body mass index (BMI) ≥ 40, 37 subjects with BMI ≥ 30 but < 40, and 60 age-and sex-matched control subjects, were included in our study. Serum endocan, ADAMTS97, and ADAMTS9 levels as well as PWV and CIMT measurements of the subjects in the obese and control groups were performed. Results: In the obesity group, PWV levels were significantly higher than they were in the control group and endocan levels were significantly lower than they were in the control group. When we compared the obese group with BMI ≥ 40 and the control group, the BMI ≥ 40 group had significantly higher PWV and CIMT levels than the control group had, whereas endocan, ADAMTS7, and ADAMTS9 levels were similar to those of the control group. When we compared the obese group with BMI ≥ 30 < 40 to the control group, endocan levels were lower in the group with BMI ≥30 < 40, and PWV and CIMT levels were similar to the control group. Conclusion: We found that arterial stiffness and CIMT increased in obese patients with BMI ≥ 40 and that increased arterial stiffness was associated with age, systolic blood pressure, and HBA1C. In addition, we found that the endocan levels were lower in obese patients than they were in nonobese control individuals.

The rs3825807 Polymorphism of ADAMTS7 as a Potential Genetic Marker for Myocardial Infarction in Slovenian Subjects with Type 2 Diabetes Mellitus.

BACKGROUND: A disintegrin and metalloprotease with thrombospondin motif 7 (ADAMTS-7) was reported to play a role in the migration of vascular smooth muscle cells and neointimal formation. The object of the study was to investigate the association between the rs3825807 polymorphism of ADAMTS7 and myocardial infarction among patients with type 2 diabetes mellitus in a Slovenian cohort. METHODS: 1590 Slovenian patients with type 2 diabetes mellitus were enrolled in this retrospective cross-sectional case-control study. In total, 463 had a history of recent myocardial infarction, and 1127 of the subjects in the control group had no clinical signs of coronary artery disease. Genetic analysis of an rs3825807 polymorphism of ADAMTS7 was performed with logistic regression. RESULTS: Patients with the AA genotype had a higher prevalence of myocardial infarction than those in the control group in recessive [odds ratio (OR) 1.647; confidence interval (CI) 1.120-2.407; p = 0.011] and co-dominant (OR 2.153; CI 1.215-3.968; p = 0.011) genetic models. CONCLUSION: We found a statistically significant association between rs3825807 and myocardial infarction in a cohort of Slovenian patients with type 2 diabetes mellitus. We report that the AA genotype might be a genetic risk factor for myocardial infarction.

ADAMTS-7 deficiency attenuates thoracic aortic aneurysm and dissection in mice.

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening cardiovascular disease with severe extracellular matrix (ECM) remodeling that lacks efficient early stage diagnosis and nonsurgical therapy. A disintegrin and metalloproteinase with thrombospondin motif 7 (ADAMTS-7) is recognized as a novel locus for human coronary artery atherosclerosis. Previous work by us and others showed that ADAMTS-7 promoted atherosclerosis, postinjury neointima formation, and vascular calcification. However, whether ADAMTS-7 is involved in TAAD pathogenesis is unknown. We aimed to explore the alterations in ADAMTS-7 expression in human and mouse TAAD, and investigate the role of ADAMTS-7 in TAAD formation. A case-control study of TAAD patients (N = 86) and healthy participants (N = 88) was performed. The plasma ADAMTS-7 levels were markedly increased in TAAD patients within 24 h and peaked in 7 days. A TAAD mouse model was induced with 0.5% ß-aminopropionitrile (BAPN) in drinking water. ELISA analysis of mouse plasma, Western blotting, and immunohistochemical staining of aorta showed an increase in ADAMTS-7 in the early stage of TAAD. Moreover, ADAMTS-7-deficient mice exhibited significantly attenuated TAAD formation and TAAD rupture-related mortality in both male and female mice, which was accompanied by reduced artery dilation and inhibited elastin degradation. ADAMTS-7 deficiency caused repressed inflammatory response and complement system activation during TAAD formation. An increase in plasma ADAMTS-7 is a novel biomarker for human TAAD. ADAMTS-7 deficiency attenuates BAPN-induced murine TAAD. ADAMTS-7 is a potential novel target for TAAD diagnosis and therapy. KEY MESSAGES: A case-control study revealed increased plasma ADAMTS-7 is a risk factor for TAAD. ADAMTS-7 was elevated in plasma and aorta at early stage of mouse TAAD. ADAMTS-7 knockout attenuated mouse TAAD formation and mortality in both sexes.

New Markers for Cardiovascular Disease in Psoriatic Patients: Preliminary Study on Monocyte Phenotype, ADAMTS7, and mTOR Activity.

Psoriasis is a skin disease with occasional involvement of non-cutaneous territories. Beyond the usual, cardiovascular events are more frequent in these patients and correlate only partially with disease activity, suggesting the presence of other unknown factors. We selected ten psoriatic patients without treatment in the last year and matched them for age and gender with eleven healthy subjects. Ficoll-extracted mononuclear cells were analyzed with flow cytometry for monocyte surface phenotype markers, intracellular NFκB/inflammasome-dependent interleukins, and chemotaxis receptor CXCR3. Using ELISA, patient serum was evaluated for ADAMTS7 and CXCL10. Inflammatory M1 monocytes showed higher levels of IL-1ß and IL-6 in psoriatic patients. M2 monocytes also showed higher levels of intracellular inflammatory cytokines. Nevertheless, IL-6 values were higher compared to other monocytes and IL-1ß. The mTORC activation markers ADAMTS7 and S6Rp were higher in psoriatic patients than in healthy controls. In psoriatic patients, serum levels of ADAMTS7 were elevated, and M2 monocytes showed a distinct inflammatory response with higher relative levels of NFκB-dependent IL-6 and less activity of the CXCR3-CXCL10 chemotactic pathway. These data suggest pathways with potential markers for prediction and early detection of cardiovascular risk in psoriatic patients.

Peptide Vaccine Against ADAMTS-7 Ameliorates Atherosclerosis and Postinjury Neointima Hyperplasia.

BACKGROUND: The metalloprotease ADAMTS-7 (a disintegrin and metalloproteinase with thrombospondin type 1 motif 7) is a novel locus associated with human coronary atherosclerosis. ADAMTS-7 deletion protects against atherosclerosis and vascular restenosis in rodents. METHODS: We designed 3 potential vaccines consisting of distinct B cell epitopic peptides derived from ADAMTS-7 and conjugated with the carrier protein KLH (keyhole limpet hemocyanin) as well as aluminum hydroxide as an adjuvant. Arterial ligation or wire injury was used to induce neointima in mice, whereas ApoE-/- and LDLR-/- (LDLR [low-density lipoprotein receptor]) mice fed a high-fat diet were applied to assess atherosclerosis. In addition, coronary stent implantation was performed on vaccine-immunized Bama miniature pigs, followed by optical coherence tomography to evaluate coronary intimal hyperplasia. RESULTS: A vaccine, ATS7vac, was screened out from 3 candidates to effectively inhibit intimal thickening in murine carotid artery ligation models after vaccination. As well, immunization with ATS7vac alleviated neointima formation in murine wire injury models and mitigated atherosclerotic lesions in both hyperlipidemic ApoE-/- and LDLR-/- mice without lowering lipid levels. Preclinically, ATS7vac markedly impeded intimal hyperplasia in swine stented coronary arteries, but without significant immune-related organ injuries. Mechanistically, ATS7vac vaccination produced specific antibodies against ADAMTS-7, which markedly repressed ADAMTS-7-mediated COMP (cartilage oligomeric matrix protein) and TSP-1 (thrombospondin-1) degradation and subsequently inhibited vascular smooth muscle cell migration but promoted re-endothelialization. CONCLUSIONS: ATS7vac is a novel atherosclerosis vaccine that also alleviates in-stent restenosis. The application of ATS7vac would be a complementary therapeutic avenue to the current lipid-lowering strategy for atherosclerotic disease.

miR-654-5p Suppresses Migration and Proliferation of Vascular Smooth Muscle Cells by Targeting ADAMTS-7.

Coronary artery disease (CAD) is the first leading cause of death worldwide. Therefore, novel therapeutic strategies need to be explored. Numerous publications reported that microRNA-654-5p (miR-654-5p) had anti-cancer activities in various cancers, and it was proven to modulate cell migration, invasion, and proliferation, which played critical roles in CAD. However, its role in CAD is unknown. Thus, we aimed to evaluate the role of miR-654-5p in vascular smooth muscle cells (VSMCs) involved in CAD. A total of 25 CAD patients and 19 healthy individuals were enrolled to evaluate their circulating miR-654-5p levels. miR-654-5p mimic or inhibitor were transfected into human VSMCs to assess their role on cell migration and proliferation. Target genes of miR-654-5p were predicted using TargetScan 7.2 and confirmed by the dual-luciferase reporter assay. miR-654-5p was significantly downregulated in the plasma of CAD patients and tumor necrosis factor-a/platelet-derived growth factor (PDGF)-BB-stimulated VSMCs. miR-654-5p mimic inhibited the proliferation and migration of VSMCs, which could be promoted by miR-654-5p inhibitor. A disintegrin and metalloproteinase with thrombospondin motifs-7 (ADAMTS-7) was identified as the direct target of miR-654-5p, whose expression could be induced by miR-654-5p inhibitor and decreased by its mimic. In addition, ADAMTS-7 overexpression blocked the inhibitory effect of miR-654-5p on the migration and proliferation of VSMCs. In summary, miR-654-5p inhibits the migration and proliferation of VSMCs by directly targeting ADAMTS-7, and miR-654-5p might serve as a novel therapeutic target for the treatment of CAD.

Evaluation of subclinical atherosclerosis in obese patients with three noninvasive methods: Arterial stiffness, carotid intima-media thickness, and biomarkers of endothelial dysfunction

ABSTRACT Objective: In this study, we aimed to evaluate subclinical atherosclerosis in patients with obesity who had cardiovascular disease risk indicators such as arterial stiffness, which is evaluated using pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and biomarkers of endothelial dysfunction such as endocan, ADAMTS97, and ADAMTS9. Subjects and methods: Sixty obese subjects, including 23 subjects with body mass index (BMI) ≥ 40, 37 subjects with BMI ≥ 30 but < 40, and 60 age-and sex-matched control subjects, were included in our study. Serum endocan, ADAMTS97, and ADAMTS9 levels as well as PWV and CIMT measurements of the subjects in the obese and control groups were performed. Results: In the obesity group, PWV levels were significantly higher than they were in the control group and endocan levels were significantly lower than they were in the control group. When we compared the obese group with BMI ≥ 40 and the control group, the BMI ≥ 40 group had significantly higher PWV and CIMT levels than the control group had, whereas endocan, ADAMTS7, and ADAMTS9 levels were similar to those of the control group. When we compared the obese group with BMI ≥ 30 < 40 to the control group, endocan levels were lower in the group with BMI ≥ 30 < 40, and PWV and CIMT levels were similar to the control group. Conclusions: We found that arterial stiffness and CIMT increased in obese patients with BMI ≥ 40 and that increased arterial stiffness was associated with age, systolic blood pressure, and HBA1C. In addition, we found that the endocan levels were lower in obese patients than they were in nonobese control individuals.

ADAMTS7 Attenuates House Dust Mite-Induced Airway Inflammation and Th2 Immune Responses.

PURPOSE: ADAMTS7 is a secreted metalloproteinase enzyme and proteoglycan associated with the early progression of coronary artery disease. However, there is limited information regarding the role of ADAMTS7 in lung adaptive immunity and inflammation. Thus, we sought to assess whether ADAMTS7 expression in the lung modulates house dust mite (HDM)-induced airway inflammation and Th2 immune response. METHODS: The role of ADAMTS7 in HDM-induced airway disease was assessed in ADAMTS7-deficient (ADAMTS7-/-) mice and compared with the wild-type control mice by flow cytometry, ELISA, and histopathology. Furthermore, the antigen priming capability of dendritic cells (DC) was determined ex vivo by employing coculture with CD4+ OT-II cells. RESULTS: ADAMTS7-/- mice develop an augmented eosinophilic airway inflammation, mucous cell metaplasia, and increased Th2 immune response to inhaled HDM. In addition, allergen uptake by lung DC and migration to draining mediastinal lymph node were significantly increased in ADAMTS7-/- mice, which shows an enhanced capacity to mount allergen-specific T-cell proliferation and effector Th2 cytokine productions. We propose that the mechanism by which ADAMTS7 negatively regulates DC function involves attenuated antigen uptake and presentation capabilities, which reduces allergic sensitization and Th2 immune responses in the lung. CONCLUSION: In aggregate, we provide compelling evidence that ADAMTS7 plays a pivotal role in allergic airway disease and Th2 immunity and would be an attractive target for asthma.

TAILS Identifies Candidate Substrates and Biomarkers of ADAMTS7, a Therapeutic Protease Target in Coronary Artery Disease.

Loss-of-function mutations in the secreted enzyme ADAMTS7 (a disintegrin and metalloproteinase with thrombospondin motifs 7) are associated with protection for coronary artery disease. ADAMTS7 catalytic inhibition has been proposed as a therapeutic strategy for treating coronary artery disease; however, the lack of an endogenous substrate has hindered the development of activity-based biomarkers. To identify ADAMTS7 extracellular substrates and their cleavage sites relevant to vascular disease, we used TAILS (terminal amine isotopic labeling of substrates), a method for identifying protease-generated neo-N termini. We compared the secreted proteome of vascular smooth muscle and endothelial cells expressing either full-length mouse ADAMTS7 WT, catalytic mutant ADAMTS7 E373Q, or a control luciferase adenovirus. Significantly enriched N-terminal cleavage sites in ADAMTS7 WT samples were compared to the negative control conditions and filtered for stringency, resulting in catalogs of high confidence candidate ADAMTS7 cleavage sites from our three independent TAILS experiments. Within the overlap of these discovery sets, we identified 24 unique cleavage sites from 16 protein substrates, including cleavage sites in EFEMP1 (EGF-containing fibulin-like extracellular matrix protein 1/Fibulin-3). The ADAMTS7 TAILS preference for EFEMP1 cleavage at the amino acids 123.124 over the adjacent 124.125 site was validated using both endogenous EFEMP1 and purified EFEMP1 in a binary in vitro cleavage assay. Collectively, our TAILS discovery experiments have uncovered hundreds of potential substrates and cleavage sites to explore disease-related biological substrates and facilitate activity-based ADAMTS7 biomarker development.

Development of a fluorogenic ADAMTS-7 substrate.

The extracellular protease ADAMTS-7 has been identified as a potential therapeutic target in atherosclerosis and associated diseases such as coronary artery disease (CAD). However, ADAMTS-7 inhibitors have not been reported so far. Screening of inhibitors has been hindered by the lack of a suitable peptide substrate and, consequently, a convenient activity assay. Here we describe the first fluorescence resonance energy transfer (FRET) substrate for ADAMTS-7, ATS7FP7. ATS7FP7 was used to measure inhibition constants for the endogenous ADAMTS-7 inhibitor, TIMP-4, as well as two hydroxamate-based zinc chelating inhibitors. These inhibition constants match well with IC50 values obtained with our SDS-PAGE assay that uses the N-terminal fragment of latent TGF-ß-binding protein 4 (LTBP4S-A) as a substrate. Our novel fluorogenic substrate ATS7FP7 is suitable for high throughput screening of ADAMTS-7 inhibitors, thus accelerating translational studies aiming at inhibition of ADAMTS-7 as a novel treatment for cardiovascular diseases such as atherosclerosis and CAD.

Investigating ADAMTS7 and ADAMTS12 levels in prediabetic and Type 2 diabetic patients.

Background: This study aims to investigate the role of ADAMTS7 and ADAMTS12 on atherosclerosis and inflammation in prediabetic and diabetic patients. Patients & methods: Serum ADAMTS7 and ADAMTS12 levels were compared with the atherosclerotic and inflammatory markers in diabetic (n = 65, female 30.9%, mean age = 53 years), prediabetic (n = 55, female 36.6%, mean age = 49 years) and control groups (n = 55, females 32.5%, mean age = 49 years). Serum ADAMTS levels were determined by a human enzyme-liked immunoassay. Results: In terms of ADAMTS7, there was no significant difference between diabetic, prediabetic and control groups (50.93, 44.34, 59.07, respectively; p > 0.05). ADAMTS12 is lower in diabetics (p < 0.05), whereas it is similar in prediabetics and controls (14.53, 20.76, 25.05, respectively; p > 0.05). ADAMTS7 and ADAMTS12 levels did not differ in diabetic nephropathy, retinopathy and neuropathy (p > 0.05). Conclusion: While ADAMTS12 was significantly lower in diabetics and prediabetics, ADAMTS7 and ADAMTS12 were not related to diabetic complications (nephropathy, retinopathy and neuropathy).

Association of polymorphisms in ADAMTS-7 gene with the susceptibility to coronary artery disease - a systematic review and meta-analysis.

OBJECTIVE: To systematically review literature evidence to discover the association of ADAMTS7 (A Disintegrin And Metalloproteinase with Thrombospondin-like motifs 7) polymorphisms and the risk of developing CAD (coronary artery disease). DATA SOURCES: A related literature search in online databases, including EMBASE, PubMed, and Web of Science was undertaken. The period covered was from 2007 to September 10, 2019. RESULTS: Of 256 citations retrieved, nine relevant studies were selected for detailed evaluation. Five SNPs (rs3825807, rs1994016, rs4380028, rs79265682, and rs28455815) in ADAMTS7 gene were identified among included studies. There were 51,851 cases and 89,998 controls included in four studies for SNP rs3825807, 13,403 cases and 11,381 controls included in two studies for SNP rs1994016, 37,838 cases and 38,245 controls included in two studies for SNP rs4380028, 3,133 cases and 5,423 controls included in one study for SNP rs79265682, 103,494 cases and 198,684 controls included in one study for SNP rs28455815. We found most consistent evidence for an association with CAD on coronary angiogram with ADAMTS7 SNP rs3825807 risk allele A in contrast to control G allele, followed by rs4380028 (C vs. T allele), and rs1994016 (C vs. T allele). CONCLUSIONS: ADAMTS7 polymorphism is likely an important risk factor for development of CAD. Our data also suggest that the ADAMTS7 polymorphism may be a risk factor for CAD progression in patients who already have pathology in their coronary arteries. REVIEW METHODS: We included all studies in English language that reported correlation between the ADAMTS7 polymorphism and CAD in human cases.

Hypomethylation of DNA promoter upregulates ADAMTS7 and contributes to HTR-8/SVneo and JEG-3 cells abnormalities in pre-eclampsia.

INTRODUCTION: Accumulating evidences have suggested a crucial role of epigenetics in the initiation and progression of pre-eclampsia (PE). Here, we studied the expression of the metalloproteinase ADAMTS7 and the methylation level of its promoter in PE placentas and investigated ADAMTS7 role in the pathogenesis of PE. METHODS: We first explored ADAMTS7 expression in PE and normal placentas by reverse transcription quantitative PCR (RT-qPCR), western blot, and immunohistochemistry. Methylation specific PCR (MSP) and bisulfite sequencing PCR (BSP) were performed to evaluate the methylation status of ADAMTS7 promoter. Treatment with 5'-Aza was used to induce demethylation and thereby to explore the direct relationship between promoter methylation and ADAMTS7 expression. CCK8 assay, colony formation assay, and trans-well assay were conducted to assess the viability, migration, and invasion of HTR-8/SVneo and JEG-3 cells. RESULTS: Our results showed that ADAMTS7 expression was upregulated in PE placentas. Methylation analysis revealed a hypomethylated status of ADAMTS7 promoter regions in PE placenta tissues. Besides, demethylation induced by 5'-Aza directly restored ADAMTS7 expression in trophoblast cells. Finally, overexpression of ADAMTS7 inhibited viability, migration, and invasion of HTR-8/SVneo and JEG-3 cells, while silence of ADAMTS7 by RNA interference reciprocally facilitated cell viability, migration and invasion in vitro. DISCUSSION: Upregulation of ADAMTS7 by promoter hypomethylation in placenta might contribute to the etiology of PE via suppressing cell functions of trophoblasts.

ADATMS-7 regulates the focal adhesion kinase signaling and promotes invasiveness of trophoblasts in early pregnancy.

INTRODUCTION: ADAMTS-7, a member of the disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family, was recently identified to be associated with cell migration and invasion. However, its function on trophoblasts remains unknown. In this study, we are aimed to investigate the role of ADAMTS-7 on trophoblasts in human first trimester gestation. METHODS: The expression of ADAMTS-7 in trophoblasts and HTR8/SVneo cells is examined by immunohistochemistry and quantitative real-time PCR. BrdU incorporation and Annexin V/PI staining are utilized to measure the effect of ADAMTS-7 on the proliferation and apoptosis of HTR8/SVneo cells, respectively. In addition, we detect the role of ADAMTS-7 on the invasion ability of HTR8/SVneo cells using matrigel invasion assays. The activation of focal adhesion kinase (FAK) and integrinß1 induced by ADAMTS-7 were determined by Western blot. RESULTS: ADAMTS-7 and its substrate cartilage oligomeric matrix protein (COMP) were expressed in both primary human trophoblasts and human trophoblast cell lines. TGF-ß1 induced a continuous and significant decrease of ADAMTS-7. Inversely, IL-1ß up-regulated the ADAMTS-7 level in a dosage dependent manner. In addition, knockdown of ADAMTS-7 inhibited the growth and invasion of HTR8/SVneo cells. To the contrary, ADAMTS-7 overexpression promoted the growth and invasion of HTR8/SVneo cells. ADAMTS-7 knockdown led to a decreased level of FAK Tyr-397 phosphorylation. DISCUSSION: Our results suggest that ADAMTS-7 may regulate trophoblasts invasion through focal adhesion kinase (FAK) signaling.

Effect of a coronary-heart-disease-associated variant of ADAMTS7 on endothelial cell angiogenesis.

BACKGROUND AND AIMS: Recent studies have unveiled an association between ADAMTS7 gene variation and coronary artery disease (CAD) caused by atherosclerosis. We investigated if the ADAMTS7 Serine214-to-Proline substitution arising from a CAD-associated variant affected angiogenesis, since neovascularization plays an important role in atherosclerosis. METHODS AND RESULTS: ADAMTS7 knockdown in vascular endothelial cells (ECs) attenuated their angiogenesis potential, whereas augmented ADAMTS7-Ser214 expression had the opposite effect, leading to increased ECs migratory and tube formation ability. Proteomics analysis showed an increase in thrombospondin-1, a reported angiogenesis inhibitor, in culture media conditioned by ECs with ADAMTS7 knockdown and a decrease of thrombospondin-1 in media conditioned by ECs with ADAMTS7-Ser214 overexpression. Cleavage assay indicated that ADAMTS7 possessed thrombospondin-1 degrading activity, which was reduced by the Ser214-to-Pro substitution. The pro-angiogenic effect of ADAMTS7-Ser214 diminished in the presence of a thrombospondin-1 blocking antibody. CONCLUSIONS: The ADAMTS7 Ser217-to-Pro substitution as a result of ADAMTS7 polymorphism affects thrombospondin-1 degradation, thereby promoting atherogenesis through increased EC migration and tube formation.

ADAMTS7: Recombinant Protein Expression and Purification.

ADAMTS7 is a secreted protease that is predominantly expressed in tissues of the cardiovascular system and tendon. Although recent evidence suggests that it may play a role in the etiology of coronary artery disease, its physiological function and substrates are unknown. The enzyme undergoes extensive posttranslational modifications, including chondroitin sulfate attachment, N and O-linked glycosylation, and a two-step activation process. For the benefit of scientists who study the function of ADAMTS7 and its role in disease, this chapter provides an introduction to the chemical and functional properties of the various ADAMTS7 domains, as well as a protocol for the recombinant expression and purification of ADAMTS7.