And Metalloproteinase With Thrombospondin Motifs Research Articles

Glycoproteomic Analysis of the Aortic Extracellular Matrix in Marfan Patients.

Marfan syndrome (MFS) is caused by mutations in FBN1 (fibrillin-1), an extracellular matrix (ECM) component, which is modified post-translationally by glycosylation. This study aimed to characterize the glycoproteome of the aortic ECM from patients with MFS and relate it to aortopathy. Approach and Results: ECM extracts of aneurysmal ascending aortic tissue from patients with and without MFS were enriched for glycopeptides. Direct N-glycopeptide analysis by mass spectrometry identified 141 glycoforms from 47 glycosites within 35 glycoproteins in the human aortic ECM. Notably, MFAP4 (microfibril-associated glycoprotein 4) showed increased and more diverse N-glycosylation in patients with MFS compared with control patients. MFAP4 mRNA levels were markedly higher in MFS aortic tissue. MFAP4 protein levels were also increased at the predilection (convexity) site for ascending aorta aneurysm in bicuspid aortic valve patients, preceding aortic dilatation. In human aortic smooth muscle cells, MFAP4 mRNA expression was induced by TGF (transforming growth factor)-β1 whereas siRNA knockdown of MFAP4 decreased FBN1 but increased elastin expression. These ECM changes were accompanied by differential gene expression and protein abundance of proteases from ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family and their proteoglycan substrates, respectively. Finally, high plasma MFAP4 concentrations in patients with MFS were associated with a lower thoracic descending aorta distensibility and greater incidence of type B aortic dissection during 68 months follow-up. Our glycoproteomics analysis revealed that MFAP4 glycosylation is enhanced, as well as its expression during the advanced, aneurysmal stages of MFS compared with control aneurysms from patients without MFS.

Age-related Macular Degeneration: Current Knowledge of Zinc Metalloproteinases Involvement.

Advanced age-related macular degeneration (AMD) is the leading cause of blindness in the elderly with limited therapeutic options. The disease is characterized by photoreceptor loss in the macula and reduced Retinal Pigment Epithelium (RPE) function, associated with matrix degradation, cell proliferation, neovascularization and inflammation. Matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) play a critical role in the physiology of extracellular matrix (ECM) turnover and, in turn, in ECM pathologies, such as AMD. A balance between the activities of MMPs and Tissue Inhibitors of Metalloproteinase (TIMPs) is crucial for the integrity of the ECM components; indeed, a dysregulation in the ratio of these factors produces profound changes in the ECM, including thickening and deposit formation, which eventually might lead to AMD development. This article reviews the relevance and impact of zinc metalloproteinases on the development of AMD and their roles as biomarkers and/or therapeutic targets. We illustrate some studies on several inhibitors of MMPs currently used to dissect physiological properties of MMPs. Moreover, all molecules or technologies used to control MMP and ADAM activity in AMD are analyzed. This study underlines the changes in the activity of MMPs expressed by RPE cells, highlights the functions of already used MMP inhibitors and consequently suggests their application as therapeutic agents for the treatment of AMD.

Validation of the Diagnostic and Prognostic Values of ADAMTS5 and FSTL1 in Osteoarthritis Rat Model.

Osteoarthritis (OA) is a global public health problem and a leading cause of morbidity and disability. Due to lack of sensitive and specific tools for early OA diagnosis and predicting prognosis, the availability of new reliable and sensitive biomarkers is a widely appreciated need to identify patients at risk for incident disease or disease progression. Accordingly, our study was conducted to validate the usefulness of disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) and follistatin-like protein 1 (FSTL1) to achieve this goal. Fifty-four male Wistar rats were randomized into 3 groups; 24 rats were subjected to medial meniscal tear (MMT) surgery on the right knee joint (OA group), 24 rats were subjected to sham surgery (sham group), and 6 healthy rats (negative control group). Six animals from each group were sacrificed every 2 weeks. At each time point, the right knee joint of each animal was visualized radiologically, a blood sample was collected, and cartilage tissues were isolated for histopathological and western blot analysis. We found that the expression levels of ADAMTS5 and FSTL1 significantly increased with OA progression, especially at weeks 4, 6, and 8 after surgery. Notably, the serum levels of ADAMTS5 and FSTL1 showed significant positive correlations with each other and with the studied inflammatory markers. Our findings suggest that ADAMTS5 and FSTL1 can serve as important and informative serological markers of disease activity in OA. However, further research is needed to validate their use for improving the diagnosis and prognosis of OA in humans.

Nobiletin Inhibits IL-1β-Induced Inflammation in Chondrocytes via Suppression of NF-κB Signaling and Attenuates Osteoarthritis in Mice.

Osteoarthritis (OA), a common degenerative joint disease, is principally characterized by inflammation and destruction of cartilage. Nobiletin, an extract of the peel of citrus fruits, is known to have anti-inflammatory properties. However, the mechanisms by which nobiletin plays a protective role in osteoarthritis (OA) are not completely understood. In the present study, we investigated the anti-inflammatory effects of nobiletin in the progression of OA in both in vitro and in vivo experiments. Mouse chondrocytes were pretreated with nobiletin (0, 10, 20, 40 μM) for 24 h and then incubated with IL-1β (10 ng/ml, 24 h) in vitro. The generation of PGE2 and NO was evaluated by the Griess reaction and ELISAs. The protein expression of inducible nitric oxide synthase, matrix metalloproteinase-3, matrix metalloproteinase-13, A disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS5), cyclooxygenase-2, collagen II, and aggrecan was analyzed by Western blotting. Immunofluorescence and Western blot analysis were used to detect nuclear factor-κB (NF-κB) signaling molecules. Induction of proinflammatory and catabolic mediators by IL-1β stimulation of mouse chondrocytes could be partially blocked by treatment with nobiletin or ammonium pyrrolidine dithiocarbamate (an NF-κB inhibitor). Furthermore, our results indicated that nobiletin exhibited a therapeutic effect through active inhibition of the NF-κB signaling pathway. In a mouse model of OA, injection of nobiletin (20 mg/kg) every 2 days for 8 weeks after surgery inhibited cartilage destruction and synovitis. Taken together, our findings suggest that nobiletin may be a potential therapeutic agent for the treatment of OA.

Hypoxia causes important changes of extracellular matrix biomarkers and ADAMTS proteinases in the adriamycin-induced renal fibrosis model.

Renal fibrosis is a common cause of renal dysfunction with chronic kidney diseases. This process is characterized by excessive production of extracellular matrix (ECM) or inhibition of ECM degradation. A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) proteinases, which are widely presented in mammals, have very critical roles in ECM remodelling. We aimed to study the role of ADAMTS proteinases and some of the ECM markers in the pathogenesis of renal fibrosis and to investigate the effects of hypoxia on these biomarkers. In addition to the control group, Adriamycin (ADR) treated rats were divided into four groups as ADR, sham and two hypoxia groups. Renal nephropathy was assessed biochemical assays, pathological and immunohistochemical staining methods. The expression of ADAMTSs and mRNA were determined using Western blotting and real-time PCR, respectively. Renal dysfuntion and tissue damage in favour of ECM accumulation and renal fibrosis were observed in the ADR group. This was approved by remarkable changes in the expression of ADAMTS such as increased ADAMTS-1, -12 and -15. In addition, it was found that hypoxia and duration of hypoxia enhanced markers of tubulointerstitial fibrosis in the rat kidney tissues. Also, expression differences especially in ADAMTS-1, -6 and -15 were observed in the hypoxia groups. The variable and different expression patterns of ADAMTS proteinases in the ADR-induced renal fibrosis suggest that ADAMTS family members are involved in the development and progression of fibrosis. The expression changes of ADAMTS proteinases in kidney and association with hypoxia have potential clues to contribute to the early diagnosis and treatment options of renal fibrosis.

Activation of G-protein-coupled bile acid receptor Gpbar1 (TGR5) inhibits degradation of type II collagen and aggrecan in human chondrocytes

Abnormal loss of components of the extracellular matrix (ECM) including type II collagen and aggrecan caused by proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) is an important pathophysiological characteristic of osteoarthritis (OA). G-protein-coupled bile acid receptor, Gpbar1 (TGR5), is an important member of the bile acid receptor subclass of G Protein-Coupled Receptors (GPCRs). Little information regarding the effects of TGR5 in the pathological development of OA has been reported before. In the current study, we showed that TGR5 is expressed in human primary chondrocytes and human chondrosarcoma SW1353 cells. Interestingly, expression of TGR5 was reduced in response to TNF-α treatment in SW1353 cells. Our results indicate that activation of TGR5 using its specific agonist INT-777 reduced TNF-α-induced degradation of the articular ECM, including type II collagen and aggrecan, by inhibiting expression of matrix metalloproteinase-3 (MMP-3), MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs- 4 (ADAMTS-4) and ADAMTS-5. We also found that INT-777 treatment inhibited phosphorylation of p38 and activation of the IκB kinase/inhibitory κBα/nuclear factor- κB (IKK/IκBα/NF-κB) signaling pathway. Notably, knockdown of TGR5 abolished the protective effects of INT-777 against ECM degradation, suggesting the involvement of TGR5. Our findings implicate that TGR5 might be considered as a potential therapeutic target for the treatment of OA.

Electroacupuncture down-regulates expression of ADAMTS-4 of intervertebral disc in rats with lumbar intervertebral disc degeneration

To observe the effect of electroacupuncture (EA) stimulation on the levels of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) protein in the lumbar intervertebral disc tissue and serum in prolapsed lumbar intervertebral disc degeneration (PLIDD) rats, so as to explore its mechanism underlying improvement of intervertebral disc degeneration (IDD). A total of 48 Sprague-Dawley rats were divided into sham operation (n＝12), model (n＝18) and EA (n＝18) groups. The PLIDD model was established by puncturing the lumbar discs (L4-L5, L5-L6) with a gauge-22 syringe needle. After modeling, EA stimulation was applied to "Pangguangshu"(BL28), "Zusanli"(ST36) and "Zhijian"for 20 min, 6 times per week for 4 weeks. The lumbar intervertebral disc tissue and blood samples were collected at the 4th, 6th and 8th week after modeling, respectively. The expression of ADAMTS-4 in the lumbar intervertebral disc tissue was detected by immunohistochemistry and Western blot (WB), separately. The content of ADAMTS-4 in the serum was detected by ELISA. Both immunohistochemical stain and WB showed that the expression levels of lumbar ADAMTS-4 at the 4th, 6th and 8th week were significantly up-regulated in the model group relevant to the sham operation group (P<0.01). Following EA treatment, the expression levels of ADAMTS-4 on day 14 and 28 were notably lower in the EA group than in the model group (P<0.05). The serum ADAMTS-4 contents were significantly increased in the model group than in the sham operation group at the 3 time-points (P<0.05, P<0.01), and considerably decreased in the EA group than in the model group on day 28 after EA intervention(P<0.05)．. EA can down-regulate the ADAMTS-4 expression of lumbar intervertebral disc tissue in PLIDD rats, which may contribute to its effect in relieving lumbar intervertebral disc degeneration.

The Role of Tissue Inhibitors of Metalloproteinases in Organ Development and Regulation of ADAMTS Family Metalloproteinases in Caenorhabditis elegans.

Remodeling of the extracellular matrix supports tissue and organ development, by regulating cellular morphology and tissue integrity. However, proper extracellular matrix remodeling requires spatiotemporal regulation of extracellular metalloproteinase activity. Members of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) family, including MIG-17 and GON-1, are evolutionarily conserved, secreted, zinc-requiring metalloproteinases. Although these proteases are required for extracellular matrix remodeling during gonadogenesis in Caenorhabditis elegans, their in vivo regulatory mechanisms remain to be delineated. Therefore, we focused on the C. elegans tissue inhibitors of metalloproteinases (TIMPs), TIMP-1 and CRI-2 Analysis of the transcription and translation products for GFP/Venus fusions, with TIMP-1 or CRI-2, indicated that these inhibitors were secreted and localized to the basement membrane of gonads and the plasma membrane of germ cells. A timp-1 deletion mutant exhibited gonadal growth defects and sterility, and the phenotypes of this mutant were fully rescued by a TIMP-1::Venus construct, but not by a TIMP-1(C21S)::Venus mutant construct, in which the inhibitor coding sequence had been mutated. Moreover, genetic data suggested that TIMP-1 negatively regulates proteolysis of the α1 chain of type IV collagen. We also found that the loss-of-function observed for the mutants timp-1 and cri-2 involves a partial suppression of gonadal defects found for the mutants mig-17/ADAMTS and gon-1/ADAMTS, and that this suppression was canceled upon overexpression of gon-1 or mig-17, respectively. Based on these results, we propose that both TIMP-1 and CRI-2 act as inhibitors of MIG-17 and GON-1 ADAMTSs to regulate gonad development in a noncell-autonomous manner.

Pro-atherogenic proteoglycanase ADAMTS-1 is down-regulated by lauric acid through PI3K and JNK signaling pathways in THP-1 derived macrophages.

The prevalence of atherosclerosis has increased significantly in the recent years due to sedentary lifestyle and high-fat diet. However, the association between saturated fat intake and the increased risk for atherosclerotic cardiovascular diseases remains heavily debated. Lauric acid belongs to the saturated fatty acid group and its unique medium chain fatty acid properties are proven to be beneficial to humans in many ways. Thus, the aim of this project is to investigate the effect of lauric acid on the expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) genes-ADAMTS-1, ADAMTS-4, and ADAMTS-5-in macrophages. These genes encode for proteases that participate in the extracellular matrix remodeling and they play important roles in the vulnerability of atherosclerotic plaque. Here, we show that the treatment of 20µM of lauric acid successfully reduced both transcriptional and translational expressions of these genes in THP-1 differentiated macrophages after 24-h incubation. Further cell signaling experiments using a panel of kinase inhibitors and phosphorylated antibodies proved that lauric acid down-regulated ADAMTS-1 by reducing the activation of PI3K and JNK at Tyr458 and Tyr185, respectively. Finally, JNK1 siRNA knockdown assay confirmed that ADAMTS-1 was regulated through JNK pathway, and lauric acid interfered with this pathway to down-regulate ADAMTS-1 expression. Although preliminary, this present study indicates that lauric acid has the potential to stabilize atherosclerotic plaque and may prevent thrombosis by interfering with the ADAMTS-1 expression through PI3K/JNK pathways.

Expression and Activity of TRPA1 and TRPV1 in the Intervertebral Disc: Association with Inflammation and Matrix Remodeling.

Transient receptor potential (TRP) channels have emerged as potential sensors and transducers of inflammatory pain. The aims of this study were to investigate (1) the expression of TRP channels in intervertebral disc (IVD) cells in normal and inflammatory conditions and (2) the function of Transient receptor potential ankyrin 1 (TRPA1) and Transient receptor potential vanilloid 1 (TRPV1) in IVD inflammation and matrix homeostasis. RT-qPCR was used to analyze human fetal, healthy, and degenerated IVD tissues for the gene expression of TRPA1 and TRPV1. The primary IVD cell cultures were stimulated with either interleukin-1 beta (IL-1β) or tumor necrosis factor alpha (TNF-α) alone or in combination with TRPA1/V1 agonist allyl isothiocyanate (AITC, 3 and 10 µM), followed by analysis of calcium flux and the expression of inflammation mediators (RT-qPCR/ELISA) and matrix constituents (RT-qPCR). The matrix structure and composition in caudal motion segments from TRPA1 and TRPV1 wild-type (WT) and knock-out (KO) mice was visualized by FAST staining. Gene expression of other TRP channels (A1, C1, C3, C6, V1, V2, V4, V6, M2, M7, M8) was also tested in cytokine-treated cells. TRPA1 was expressed in fetal IVD cells, 20% of degenerated IVDs, but not in healthy mature IVDs. TRPA1 expression was not detectable in untreated cells and it increased upon cytokine treatment, while TRPV1 was expressed and concomitantly reduced. In inflamed IVD cells, 10 µM AITC activated calcium flux, induced gene expression of IL-8, and reduced disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) and collagen 1A1, possibly via upregulated TRPA1. TRPA1 KO in mice was associated with signs of degeneration in the nucleus pulposus and the vertebral growth plate, whereas TRPV1 KO did not show profound changes. Cytokine treatment also affected the gene expression of TRPV2 (increase), TRPV4 (increase), and TRPC6 (decrease). TRPA1 might be expressed in developing IVD, downregulated during its maturation, and upregulated again in degenerative disc disease, participating in matrix homeostasis. However, follow-up studies with larger sample sizes are needed to fully elucidate the role of TRPA1 and other TRP channels in degenerative disc disease.

Tenascin-C promotes the repair of cartilage defects in mice

BackgroundThe effects of tenascin-C (TNC) on cartilage repair were examined in cartilage defect model mice. An in vitro study was also performed to determine the mechanism of cartilage repair with TNC. MethodsFull-thickness osteochondral defects were filled with TNC (group A: 100 μg/ml, group B: 10 μg/ml, group C: empty). Mice were sacrificed at 1, 2, 3, and 6 weeks postoperatively. Cartilage repair was histologically evaluated using the modified WAKITANI score. Chondrocytes were isolated and cultured, and they were treated with TNC. The expressions of various mRNAs including TNC, inflammatory cytokines, and anabolic and catabolic factors for cartilage were compared by real-time polymerase chain reaction. ResultsThe defects in group A were covered with hyaline-like cartilage after 3 weeks. Average modified WAKITANI scores were significantly better in group A than in groups B and C at 3 and 6 weeks. TNC upregulated the expressions of endogenous TNC, inflammatory cytokines, and anabolic and catabolic factors for cartilage. TNC downregulated the expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5. ConclusionsIntra-articular injection of full-length TNC repaired cartilage in murine models of full-thickness osteochondral defects. TNC upregulated the expression of ADAMTS4, but downregulated the expression of ADAMTS5 that contributed to cartilage degradation.

Lixisenatide attenuates advanced glycation end products (AGEs)-induced degradation of extracellular matrix in human primary chondrocytes

Osteoarthritis (OA) poses a growing threat to the health of the global population. Accumulation of advanced glycation end-products (AGEs) has been shown to upregulate expression of degradative enzymes such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) in chondrocytes, which leads to excessive degradation of type II collagen and aggrecan in the articular extracellular matrix (ECM). In the present study we investigated the effects of the GLP-1 agonist lixisenatide, a widely used type II diabetes medication, on AGEs-induced decreased mitochondrial membrane potential (MMP), degradation of ECM, oxidative stress, expression of cytokines including interleukin (IL)-1β and IL-6, and activation of nuclear factor kappa B (NF-κB). Our findings indicate that lixisenatide significantly ameliorated the deleterious effects of AGEs in a dose-dependent manner. Thus, lixisenatide has potential as a safe and effective treatment for OA and other AGEs-induced inflammatory diseases.

Peimine suppresses interleukin‑1β‑induced inflammation via MAPK downregulation in chondrocytes.

Osteoarthritis (OA) is the most common type of degenerative joint disease and secreted inflammatory molecules serve a pivotal role in it. Peimine has been reported to have anti‑inflammatory activity. In order to investigate the potential therapeutic role of Peimine in OA, mouse articular chondrocytes were treated with IL‑1β and different doses of Peimine in vitro. The data revealed that Peimine not only suppressed IL‑1β‑induced production of nitric oxide (NO) and prostaglandin E2, but also reduced the protein levels of inducible NO synthase (iNOS) and cyclooxygenase‑2 (COX‑2). In addition, Peimine inhibited the IL‑1β‑induced mRNA expression of matrix metalloproteinase (MMP)‑1, MMP‑3, MMP‑9, MMP‑13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)‑4 and ADAMTS‑5. Furthermore, Peimine inhibited IL‑1β‑induced activation of the mitogen‑activated protein kinase (MAPK) pathway. The protective effect of Peimine on IL‑1β‑treated chondrocytes was attenuated following activation of the MAPK pathway, as demonstrated by the increased expression levels of MMP‑3, MMP‑13, ADAMTS‑5, iNOS and COX‑2 compared with the Peimine group. The in vivo data suggested that Peimine limited the development of OA in the mouse model. In general, the data indicate that Peimine suppresses IL‑1β‑induced inflammation in mouse chondrocytes by inhibiting the MAPK pathway, suggesting a promising therapeutic role for Peimine in the treatment of OA.

Salmon calcitonin exerts better preventive effects than celecoxib on lumbar facet joint degeneration and long-term tactile allodynia in rats.

To evaluate and compare the effects of salmon calcitonin (sCT) and celecoxib (CLX) on cartilage, subchondral bone and tactile allodynia in a rat model of lumbar facet joint (FJ) osteoarthritis (OA). Forty 3-month-old male Sprague-Dawley rats were randomly divided into four groups: 30 received surgical collagenase (type II) injections in the right L3-L6 facet joints followed by 8 weeks of treatment with normal saline, CLX or sCT, and the other 10 received sham surgery. Tactile allodynia, changes of cartilage and subchondral bone of the L4-L5 FJs, and serum biomarkers were analyzed for all rats. Both sCT and CLX ameliorated cartilage lesions, significantly increased aggrecan expression and decreased caspase-3 expression. sCT also decreased the expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4). According to the micro-computed tomography (micro-CT) analysis, sCT significantly improved microarchitecture parameters of subchondral bone and micro-CT score; and inhibited articular process hypertrophy. CLX showed better antihyperalgesic effects than sCT on days 3 and 7 postoperatively despite no statistical differences, whereas sCT possessed better analgesic effects than CLX on days 42 and 56. Besides, the sCT treatment reduced the elevated cartilage oligomeric matrix protein (COMP) concentration in rats injected with collagenase (type II). Both sCT and CLX exerted preventive effects on FJ OA caused by collagenase (type II), but sCT showed more protective effects, particularly on maintaining cartilage metabolism, restraining the deterioration of the subchondral bone microarchitecture and tactile allodynia, and reducing serum COMP concentrations.

Effects of AURKA-mediated degradation of SOD2 on mitochondrial dysfunction and cartilage homeostasis in osteoarthritis.

This study aimed to investigate the mechanism of the ubiquitinase Aurora kinase A (AURKA) in the occurrence of osteoarthritis (OA) by mediating mitochondrial stress. Bioinformatic predictions revealed 2247 differentially expressed genes (DEGs) in the normal and OA tissues. According to the UbiNet database, 39 DEGs that code for ubiquitination enzymes was screened. AURKA was highly expressed in OA tissues and cells. AURKA interference inhibited the elevation of matrix metalloproteinase-13 (MMP-13). (MMP13), sex determining region Y-box 9 (Sox9), and a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS5) expression and the reduction of collagen type IIα (Col2a1) and Aggrecan expression in interleukin-1 β (IL-1β) induced chondrocytes. The animal experiments proved that depleting AURKA could repress the occurrence of OA. Superoxide dismutase 2 (SOD2) was determined to be AURKA ubiquitination substrate via AURKA expression and bioinformatic prediction experiments. SOD2 expression was lower in OA tissues, but higher in normal joint tissues. AURKA interference activates SOD2. Meanwhile, the IP results confirmed that AURKA could bind to SOD2 and degrade it through K48 ubiquitination. Modification and overexpression of AURKA reduce SOD2 levels. AURKA interference can reverse the reactive oxygen species elevation caused by SOD2 overexpression or lysine-48 (K48) mutation, respectively, leading to mitochondrial dysfunction. Furthermore, AURKA silencing suppressed the occurrence of OA induced by mitochondrial activation. These findings suggest that ubiquitination of AURKA lowers SOD2 expression and affects mitochondrial dysfunction to repress the occurrence of OA. The results of the current study reveal that AURKA ubiquitination influences mitochondrial dysfunction and suppresses the occurrence of OA via degradation of SOD2. These data reveal novel potential targets for OA treatment.

Associations between second-trimester amniotic fluid levels of ADAMTS4, ADAMTS5, IL-6, and TNF-α and spontaneous preterm delivery in singleton pregnancies.

Background We investigated the roles of inflammatory cytokines and the A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family in the etiopathogenesis of spontaneous preterm delivery by comparing the ADAMTS4, ADAMTS5, interleukin (IL)-6, and tumor necrosis factor-α (TNF-α) levels in second-trimester amniotic fluid between pregnant women with preterm birth and term controls. Methods All pregnant women who underwent second-trimester amniocentesis for genetic analysis between January 1, 2016, and January 1, 2018, were enrolled in this study. From this cohort, 22 patients who subsequently experienced spontaneous preterm delivery before 34 weeks of pregnancy formed the study group, and 22 age- and body mass index (BMI)-matched patients without preterm birth constituted the control group. Results No significant differences were observed between the preterm birth and control groups in terms of age, BMI, obstetric history of preterm delivery, gestational age at amniocentesis, or indication for amniocentesis. The mean amniotic fluid levels of ADAMTS4 and ADAMTS5 were significantly increased in the preterm birth group compared to the control group (248.3±22.6 and 182.4±19.8 pg/mL, P=0.012; and 198.6±21.6 and 159.1±21.7 pg/mL, P=0.035, respectively). Significantly increased IL-6 and TNF-α levels were also detected in the amniotic fluid of women who experienced spontaneous preterm delivery, relative to controls (142.1±16.2 and 95.8±16.4 pg/mL, P<0.001; and 139.4±12.5 and 89.6±11.2 pg/mL, P<0.001, respectively). Conclusion The results of this study imply that increased mid-trimester amniotic fluid levels of ADAMTS4, ADAMTS5, IL-6, and TNF-α play an important role in the pathophysiology of spontaneous preterm delivery.

An ADAMTS Sol narae is required for cell survival in Drosophila

Cell survival is essential for all living organisms to cope against multiple environmental insults. Intercellular signaling between dying and surviving cells plays an important role to ensure compensatory proliferation, preventing tissue loss after environmental stresses. Here, we show that Sol narae (Sona), a Disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) in Drosophila is required for cell survival. sona exhibited a positive genetic interaction with Death-associated inhibitor of apoptosis 1 (Diap1), and a negative genetic interaction with reaper (rpr). Transcription patterns of sona, Diap1, and rpr genes in the pouch region of wing discs were coordinately changed after irradiation. Interestingly, there was a negative correlation in the expression levels of Sona and DIAP1, and both cell types, one with high Sona level and the other with high Diap1 level, were resistant to irradiation-induced cell death. The sona-expressing cells rarely entered into cell cycle themselves but promoted the nearby cells to proliferate in irradiation conditions. We found that these sona-expressing cells are able to upregulate Cyclin D (Cyc D) and increase tissue size. Furthermore, transient Sona overexpression increased survival rate and promoted development of flies in irradiation conditions. We propose that the two types of radiation-resistant cells, one with high Sona level and the other with high Diap1 level, communicate with dying cells and between each other for cell survival and proliferation in response to irradiation.

ADAMTS-9 in Mouse Cartilage Has Aggrecanase Activity That Is Distinct from ADAMTS-4 and ADAMTS-5.

A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4 and ADAMTS-5 are the principal aggrecanases in mice and humans; however, mice lacking the catalytic domain of both enzymes (TS-4/5∆cat) have no skeletal phenotype, suggesting there is an alternative aggrecanase for modulating normal growth and development in these mice. We previously identified aggrecanase activity that (a) cleaved at E↓G rather than E↓A bonds in the aggrecan core protein, and (b) was upregulated by retinoic acid but not IL-1α. The present study aimed to identify the alternative aggrecanase. Femoral head cartilage explants from TS-4/5∆cat mice were stimulated with IL-1α or retinoic acid and total RNA was analysed by microarray. In addition to ADAMTS-5 and matrix metalloproteinase (MMP)-13, which are not candidates for the novel aggrecanase, the microarray analyses identified MMP-11, calpain-5 and ADAMTS-9 as candidate aggrecanases upregulated by retinoic acid. When calpain-5 and MMP-11 failed to meet subsequent criteria, ADAMTS-9 emerged as the most likely candidate for the novel aggrecanase. Immunohistochemistry revealed ADAMTS-9 expression throughout the mouse growth plate and strong expression, particularly in the proliferative zone of the TS-4/5-∆cat mice. In conclusion, ADAMTS-9 has a novel specificity for aggrecan, cleaving primarily at E↓G rather than E↓A bonds in mouse cartilage. ADAMTS-9 might have more important roles in normal skeletal development compared with ADAMTS-4 and ADAMTS-5, which have key roles in joint pathology.

Does butein affect adipogenesis?

ABSTRACT Butein is a plant flavonoid chalcone, with presumed anti-adipogenic properties. It was reported to impair preadipocyte differentiation, limit adipose tissue (AT) development and enhance white AT browning in rodents. In this study, we investigated the hypothesis that these effects of butein may occur via reduction of ADAMTS5 (A Disintegrin And Metalloproteinase with ThromboSpondin motifs 5) expression. Murine 3T3-L1 or 3T3-F442A preadipocytes were differentiated into mature adipocytes in the presence of butein or vehicle. At regular time intervals RNA was collected for gene expression studies. Male hemizygous mice for Tg(Ucp1-luc2,-tdTomato)1Kajim (ThermoMouse) were exposed to butein or vehicle, after which ATs were analyzed for Adamts5 and uncoupling protein-1 (Ucp-1) mRNA level changes. During preadipocyte differentiation, butein (25 – 50 mM) did not affect Adamts5 or Ucp-1 expression. Oil Red O analysis and monitoring of differentiation markers failed to demonstrate effects of butein on the differentiation extent. Furthermore, butein administration to the ThermoMouse (10 or 20 mg/kg, 4 days) or to the C57BL6/Rj mice (20 mg/kg, 4 weeks) did not enhance Adamts5 or Ucp-1 expression. Thus, we could not demonstrate marked effects of butein on the preadipocyte differentiation extent or AT development and browning, nor on Adamts5 or Ucp-1 gene expression during these processes.

LncRNA MALAT1/MiR-145 Adjusts IL-1β-Induced Chondrocytes Viability and Cartilage Matrix Degradation by Regulating ADAMTS5 in Human Osteoarthritis.

PurposeAccumulating evidence suggests that microRNA-145 (miR-145) plays an important role in osteoarthritis (OA), which is a chronic progressive joint disease. Long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) promotes metastasis in cancers and functions as a sponge for miR-145. However, the role of MALAT1/miR-145 in OA pathogenesis has not yet been elucidated.Materials and MethodsThe expression of MALAT1 and miR-145 was examined by quantitative real-time PCR; the interaction between miR-145, MALAT1 and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5 was verified by luciferase reporter assay. Correlations among MALAT1, miR-145, and ADAMTS5 were analyzed by Spearman rank analysis. Chondrocytes viability and cartilage extracellular matrix (ECM) degradation were investigated with cell viability assay and Western blotting analyzing expression of ADAMTS5, collagen type 2 alpha 1 (COL2A1), aggrecan (ACAN), and cartilage oligomeric matrix protein (COMP).ResultsMALAT1 was upregulated, and miR-145 was downregulated in OA samples and IL-1β-induced chondrocytes. Mechanically, miR-145 could directly bind to MALAT1 and ADAMTS5. Moreover, miR-145 expression was negatively correlated with MALAT1 and ADAMTS5 expression in OA patients, whereas MALAT1 and ADAMTS5 expression was positively correlated. Functionally, overexpression of MALAT1 inhibited chondrocyte viability and promoted cartilage ECM degradation in IL-1β-induced chondrocytes. In support thereof, MALAT1 silencing and miR-145 upregulation exerted the opposite effect in IL-1β-induced chondrocytes. Moreover, the effect of MALAT1 was counteracted by miR-145 upregulation, and ADAMTS5 restoration could abate miR-145 effects.ConclusionAn MALAT1/miR-145 axis contributes to ECM degradation in IL-1β-induced chondrocytes through targeting ADAMTS5, suggesting that MALAT1/miR-145/ADAMTS5 signaling may underlie human OA pathogenesis.