And Metalloproteinase With Thrombospondin Motifs Research Articles

ADAMTS12, a new candidate gene for pediatric stroke.

We recently reported a family-based genome wide association study (GWAS) for pediatric stroke pointing our attention to two significantly associated genes of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) gene family ADAMTS2 (rs469568, p = 8x10-6) and ADAMTS12 (rs1364044, p = 2.9x10-6). To further investigate these candidate genes, we applied a targeted resequencing approach on 48 discordant sib-pairs for pediatric stroke followed by genotyping of the detected non-synonymous variants in the full cohort of 270 offspring trios and subsequent fine mapping analysis. We identified eight non-synonymous SNPs in ADAMTS2 and six in ADAMTS12 potentially influencing the respective protein function. These variants were genotyped within a cohort of 270 affected offspring trios, association analysis revealed the ADAMTS12 variant rs77581578 to be significantly under-transmitted (p = 6.26x10-3) to pediatric stroke patients. The finding was validated in a pediatric venous thromboembolism (VTE) cohort of 189 affected trios. Subsequent haplotype analysis of ADAMTS12 detected a significantly associated haplotype comprising the originally identified GWAS variant. Several ADAMTS genes such as ADAMTS13 are involved in thromboembolic disease process. Here, we provide further evidence for ADAMTS12 to likely play a role in pediatric stroke. Further functional studies are warranted to assess the functional role of ADAMTS12 in the pathogenesis of stroke.

Regulation of the inflammatory cycle by a controllable release hydrogel for eliminating postoperative inflammation after discectomy

Surgery is the final choice for most patients with intervertebral disc degeneration (IDD). Operation-caused trauma will cause inflammation in the intervertebral disc. Serious inflammation will cause tissue defects and induce tissue degeneration, IDD recurrence and the occurrence of other diseases. Therefore, we proposed a scheme to treat recurrence after discectomy by inhibiting inflammation with an aspirin (ASP)-loaded hydrogel to restore the mechanical stability of the spine and relieve local inflammation. ASP-liposomes (ASP-Lips) were incorporated into a photocrosslinkable gelatin-methacryloyl (GelMA) via mixing. This material can effectively alleviate inflammation by inhibiting the release of high mobility group box 1 (HMGB1) from the nucleus to the cytoplasm. We further assessed the expression of inflammatory cytokines, such as interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α), and degeneration-related factors, such as type II collagen (COL-2), Aggrecan, matrix metallopeptidases-3 (MMP-3), MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) and ADAMTS-5 in rat nucleus pulpous cells. The level of IDD was analyzed through H&E, safranin-O staining and immunohistochemistry in rabbit samples. In vitro, we found that ASP-Lip@GelMA treatment significantly decreased inflammatory cytokines, MMP-3 and -13, and ADAMTS-4 and -5 and up-regulated COL-2 and Aggrecan via the inhibited release of HMGB-1 from the nucleus. In vivo, ASP-Lip@GelMA can effectively inhibit inflammation of local tissue after disc surgery and fill local tissue defects. This composite hydrogel system is a promising way to treat the recurrence of IDD after surgery without persistent complications.

ADAMTS7 degrades Comp to fuel BMP2-dependent osteogenic differentiation and ameliorate oncogenic potential in osteosarcomas.

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents, with a high metastatic potential. Despite dramatic changes in OS treatments over the past decades, their efficiency still remains limited, with severe complications and adverse side effects. Key mechanisms underlining tumorigenesis, metastasis and chemotherapy resistance are currently lacking, in turn hindering any progress with respect to developing effective and safe therapeutic strategies against OS. Recently, ADAMTS7, a member of the disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family, was shown to be involved in osteogenic differentiation-related pathological processes. ADAMTS7 promotes vascular calcification via disturbing the balance between osteogenic bone morphogenetic protein (BMP)2 (regulating osteogenic differentiation and bone formation during development) and its natural inhibitor cartilage oligomeric matrix protein (Comp). Hence, in the present study, we aimed to investigate the role of ADAMTS7 in the pathological process of OS. We first revealed that ADAMTS7 was decreased in OS tissues. Lower expression of ADAMTS7 was correlated with poor histological differentiation and an advanced clinical stage of OS. Through loss- and gain-function analysis, we further revealed that ADAMTS7 attenuated cell proliferation, migration and invasion, at the same time as promoting the expression of osteogenic differentiation markers in two OS cell lines: MG63 and SAOS2. Moreover, Comp was responsible for the effects of ADAMTS7 on OS pathogenesis by reinforcing cell osteogenic differentiation mediated by BMP2 invitro. In conclusion, ADAMTS7-mediated degradation of Comp may provide a potential therapeutic target for the treatment of OS.

Cinnamic Aldehyde Inhibits Lipopolysaccharide-Induced Chondrocyte Inflammation and Reduces Cartilage Degeneration by Blocking the Nuclear Factor-Kappa B Signaling Pathway.

Osteoarthritis (OA), as one of the top 10 causes of physical disability, is characterized by inflammation of the synovial membrane and progressive destruction of the articular cartilage. Cinnamic aldehyde (CA), an α,β-unsaturated aldehyde extracted from the traditional Chinese herbal medicine cinnamon (Cinnamomum verum J.Presl), has been reported to have anti-inflammatory, antioxidant, and anticancer properties. However, the anti-inflammatory effect of CA on OA remains unclear. The purpose of the present study was to investigate the effects of CA on inflammation, and cartilage degeneration in OA. A CCK-8 assay was performed to assess the potential toxicity of CA on cultured human OA chondrocytes. Following treatment with lipopolysaccharide (LPS) and CA, the expression of proinflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-alfa (TNF-α), was evaluated using quantitative real-time polymerase chain reaction (RT-qPCR) analysis, enzyme-linked immunosorbent assay, and Western blotting (WB). The production of matrix metalloproteinase-13 (MMP-13) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5) was also examined using RT-qPCR and WB. Furthermore, to investigate the potential anti-inflammatory mechanism of CA, biomarkers of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway (p65, IKB-α) were detected using WB. The results demonstrated that CA significantly inhibited the expressions of IL-1β, IL-6, TNF-α, MMP-13, and ADAMTS-5 in LPS-induced OA chondrocytes. CA dramatically suppressed LPS-stimulated NF-κB activation. Collectively, these results suggest that CA treatment may effectively prevent OA.

Involvement of Integrin-Activating Peptides Derived from Tenascin-C in Cancer Aggression and New Anticancer Strategy Using the Fibronectin-Derived Integrin-Inactivating Peptide.

Matricellular proteins, which exist in association with the extracellular matrix (ECM) and ECM protein molecules, harbor functional sites within their molecular structures. These functional sites are released through proteolytic cleavage by inflammatory proteinases, such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS), and the peptides containing these functional sites have unique biological activities that are often not detected in the parent molecules. We previously showed that tenascin-C (TNC) and plasma fibronectin (pFN), examples of matricellular proteins, have cryptic bioactive sites that have opposite effects on cell adhesion to the ECM. A peptide containing the bioactive site of TNC, termed TNIIIA2, which is highly released at sites of inflammation and in the tumor microenvironment (TME), has the ability to potently and persistently activate β1-integrins. In the opposite manner, the peptide FNIII14 containing the bioactive site of pFN has the ability to inactivate β1-integrins. This review highlights that peptide TNIIIA2 can act as a procancer factor and peptide FNIII14 can act as an anticancer agent, based on the regulation on β1-integrin activation. Notably, the detrimental effects of TNIIIA2 can be inhibited by FNIII14. These findings open the possibility for new therapeutic strategies based on the inactivation of β1-integrin by FNIII14.

Sodium butyrate protects against oxidative stress in human nucleus pulposus cells via elevating PPARγ-regulated Klotho expression

We investigated the involvement of klotho in the inhibition of oxidative stress by sodium butyrate (NaB) in human nucleus pulposus cells (NPCs). NPCs were pretreated with different concentrations of NaB for 2 h before stimulation with tert-butyl hydroperoxide (TBHP). NaB alleviated TBHP-induced oxidative injury in the NPCs, as evident by the reduced accumulation of mitochondrial superoxide, intracellular reactive oxygen species, and malondialdehyde, and increased activities of superoxide dismutase and glutathione peroxidase. Flow cytometry and western blotting showed that TBHP-induced apoptosis of NPCs was inhibited by NaB. NaB also reduced the TBHP-induced release of proteases that degrade the extracellular matrix, including matrix metalloproteinases 3 and 13, and ADAMTS-4 (a disintegrin and metalloproteinase with thrombospondin motifs 4). Intriguingly, NaB significantly reversed TBHP-induced klotho suppression. However, the protective effects of NaB on NPCs were abolished by klotho-specific small interfering RNA (siRNA). TBHP stimulation had no obvious effects on total or nuclear expression of peroxisome proliferator-activated receptor γ (PPARγ), but significantly reduced PPARγ acetylation and transcriptional activity, which were restored by NaB. TBHP stimulation also promoted the nuclear translocation of histone deacetylase 3 (HDAC3) and enhanced the association between HDAC3 and PPARγ in the nucleus, but this interaction was substantially disrupted by NaB. siRNA-induced HDAC3 knockdown significantly increased PPARγ acetylation and transactivation, reversing the TBHP-induced suppression of klotho. Therefore, NaB alleviates TBHP-induced oxidative stress in human NPCs by elevating PPARγ-regulated klotho expression. HDAC3 may be a critical HDAC subtype that mediates the regulation of PPARγ activity by NaB under oxidative stress.

Aggrecanase-selective tissue inhibitor of metalloproteinase-3 (TIMP3) protects articular cartilage in a surgical mouse model of osteoarthritis

A key feature of osteoarthritis is the gradual loss of articular cartilage and bone deformation, resulting in the impairment of joint function. The primary cause of cartilage destruction is considered to be the presence of elevated proteases, such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs). However, clinically tested global MMP inhibitors have low efficacy that may be due to their lack of selectivity. We previously demonstrated in vitro that a variant of tissue inhibitor of metalloproteinase-3 ([-1A]TIMP3) inhibits ADAMTSs but not MMPs. In this study, we tested whether the selectivity of [-1A]TIMP3 is beneficial compared with that of the wild-type TIMP3 in preventing or delaying the onset of the degenerative effects in a mouse model of osteoarthritis. We generated transgenic mice that overexpressed TIMP3 or [-1A]TIMP3 driven by a chondrocyte-specific type II collagen promoter. TIMP3 transgenic mice showed compromised bone integrity as opposed to [-1A]TIMP3 mice. After surgically induced joint instability, TIMP3 overexpression proved to be less protective in cartilage destruction than [-1A]TIMP3 at late stages of OA. The selective inhibition of ADAMTSs provides the possibility of modifying TIMP3 to specifically target a class of cartilage-degrading proteinases and to minimize adverse effects on bone and possibly other tissues.

Melatonin-triggered post-transcriptional and post-translational modifications of ADAMTS1 coordinately retard tumorigenesis and metastasis of renal cell carcinoma.

A disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) family are widely implicated in tissue remodeling events manifested in cancer development. ADAMTS1, the most fully characterized ADAMTS, plays conflicting roles in different cancer types; however, the role of ADAMTS1 in renal cell carcinoma (RCC) remains unclear. Herein, we found that ADAMTS1 is highly expressed in RCC tissues compared to normal renal tissues, and its expression was correlated with an advanced stage and a poor prognosis of RCC patients. In vitro, we observed higher expression of ADAMTS1 in metastatic (m)RCC cells compared to primary cells, and manipulation of ADAMTS1 expression affected cell invasion and clonogenicity. Results from protease array showed that ADAMTS1 is modulated by melatonin through mechanisms independent of the MT1 receptor in mRCC cells, and overexpression of ADAMTS1 relieved the invasion/clonogenicity and growth/metastasis inhibition imposed by melatonin treatment in vitro and in an orthotopic xenograft model. The human microRNA (miR) OneArray showed that miR-181d and miR-let-7f were induced by melatonin and, respectively, targeted the 3'-UTR and non-3'-UTR of ADAMTS1 to suppress its expression and mRCC invasive ability. Clinically, RCC patients with high levels of miR-181d or miR-let-7f and a low level of ADAMTS1 had the most favorable prognoses. In addition, ubiquitin/proteasome-mediated degradation of ADAMTS1 can also be triggered by melatonin. Together, our study indicates that ADAMTS1 may be a useful biomarker for predicting RCC progression. The novel convergence between melatonin and ADAMTS1 post-transcriptional and post-translational regulation provides new insights into the role of melatonin-induced molecular regulation in suppressing RCC progression.

Vitamin D3 protects articular cartilage by inhibiting the Wnt/β-catenin signaling pathway.

Low expression levels of 25-hydroxyvitamin D (vitamin D3) in the blood have been reported to be associated with the progression of osteoarthritis; however, the mechanisms by which this occurs remain unclear. The present study aimed to determine the effects of vitamin D3 on chondrocytes. MTT assays were used to determine whether vitamin D3 affects chondrocytes viability. Primary chondrocytes were treated with control culture medium, vitamin D3, tumor necrosis factor (TNF)-α, TNF-α + PNU-74654 [Wingless-related integration site (Wnt)/β-catenin signaling pathway inhibitor] or TNF-α + vitamin D3. Reverse transcription-quantitative PCR and western blotting were utilized to measure the gene and protein expression of collagen II, aggrecan, matrix metalloproteinase (MMP)-3 and MMP-13, A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4, ADAMTS-5, Wnt-3a and nuclear β-catenin. The results demonstrated that TNF-α reduced the expression levels of aggrecan and collagen II, and increased the expression levels of MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5. Furthermore, vitamin D3 and PNU-74654 were observed to partially attenuate the effects induced by TNF-α. Moreover, similar findings were reported following co-treatment with vitamin D3 and TNF-α. Western blotting data revealed that TNF-α increased Wnt-3a and β-catenin protein levels in chondrocytes, while Vitamin D3 and PNU-74654 decreased the expression levels of Wnt-3a and nuclear β-catenin. In conclusion, the findings of the present study provided evidence to suggest that vitamin D3 may prevent articular cartilage degeneration and osteoarthritic disease progression by inhibiting the expression levels of MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 through suppressing the Wnt/β-catenin signaling pathway. These results suggested that vitamin D3 may be of therapeutic value for the prevention and treatment of osteoarthritis.

FRI0411 SAFETY, TOLERABILITY, PHARMACOKINETICS AND PHARMACODYNAMICS IN HEALTHY MALE JAPANESE SUBJECTS OF THE ADAMTS-5 INHIBITOR S201086/GLPG1972, A POTENTIAL NEW TREATMENT IN OA

Background:The disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5) is a key enzyme in OA (Verma P,et al.J Cell Biochem 2011;112:3507-14). In preclinical models of OA, S201086, a potent and selective ADAMTS-5 inhibitor, protects from cartilage degradation (Clement-Lacroix,et al.Osteoarthritis Cartilage 2017;25:S58). Therefore, S201086 is co-developed by Servier and Galapagos (GLPG1972) as a potential new treatment in OA.Objectives:This phase I study was to assess and compare the safety, tolerability, pharmacokinetics and pharmacodynamics of S201086 in healthy male Japanese and Caucasian subjects.Methods:Six ascending single doses of S201086 (50 to 1500 mg) were administered orally as tablets in fasting conditions in 6 groups of 8 Japanese subjects (aged 20-45 years) and 3 ascending multiple doses (300, 600 or 1050 mg/day for 14 days) were administered orally as tablets in fed conditions in 3 groups of 8 Japanese subjects. Additionally, 2 cohorts of 8 Caucasian subjects received either a single oral dose of 300 mg or repeated oral dose of 300 mg once daily for 14 days. In each group, 6 subjects received S201086 and 2 placebo. Plasma was collected at several time points for the quantification of S201086 by LC-MS/MS. Plasma pharmacokinetic parameters were calculated via non-compartmental analysis using Phoenix® WinNonlin® software. Pharmacodynamics was assessed by measurement of the aggrecan ARGS neoepitope levels in serum by ELISA.Results:No serious adverse drug reactions were observed after administration of single and multiple ascending doses of S201086 in either Japanese or Caucasian subjects. Most adverse events were of mild to moderate intensity and were resolved by the end of the study. Following single administration to Japanese subjects, Cmax and AUC increased proportionally with doses from 50 to 600 mg and slightly less than dose-proportionally from 600 to 1500 mg, consistent with what was previously observed in the first in-human study in healthy Caucasian subjects (van der Aar E,et al.Osteoarthritis Cartilage 2018;26:S310). In Japanese subjects, after 14-days administration, a limited 1.2- to 1.4-fold accumulation was observed on both Cmax and AUC at Day14 as compared to Day1, and the steady-state exposure increased dose-proportionally within the 300-1050 mg dose range. Taking the inter-subject variability into account, no difference was observed in Cmax and AUC between Caucasian and Japanese subjects after single administrations of 300 mg and repeated administrations of 300 mg once daily for 14 days. The serum ARGS neoepitope levels decreased between baseline and last day of treatment for S201086-treated subjects but not for subjects receiving placebo. This decrease was similar for the 3 tested doses in Japanese subjects and was significant as compared to the placebo-treated subjects.Table.Comparison of ARGS concentration relative change from baseline to last day of treatment according to dose in Japanese participantsS 201086 300 mg (N = 6)S 201086 600 mg (N = 6)S 201086 1050 mg (N = 6)Placebo (N = 6)Descriptive Statistics(D14 pre-dose – Baseline) / Baselinen6646Mean ± SD-42.67 ± 8.81-53.70 ± 6.50-54.11 ± 5.2013.35 ± 16.53Statistical analysisE (SE)56.01 (6.156)67.04 (6.156)67.45 (6.883)95% CI43.08; 68.9554.11; 79.9752.99; 81.91p-value< 0.0001< 0.0001< 0.0001Conclusion:S201086 was shown to be safe and well-tolerated in Japanese and Caucasian healthy male subjects with a suitable PK profile and a significant decrease of the ARGS neoepitope, indicating target engagement. A global Phase 2 study to evaluate the efficacy of S201086 in patients with knee OA is ongoing (NCT03595618).Disclosure of Interests:Agnès Lalande Employee of: Institut de Recherches Internationales Servier, Nadya KUZNIATSOVA-MOUCHETTE Employee of: Institut de Recherches Internationales Servier, Florian CHASSEREAU Employee of: Institut de Recherches Internationales Servier, Julia GERONIMI Employee of: Institut de Recherches Internationales Servier, Katy Bernard Employee of: Institut de Recherches Internationales Servier, Staffan Larsson: None declared, André Struglics: None declared, Stefan Lohmander: None declared, Maria Pueyo Employee of: Institut de Recherches Internationales Servier

Metalloproteinases and Their Inhibitors: Potential for the Development of New Therapeutics.

The metalloproteinase (MP) family of zinc-dependent proteases, including matrix metalloproteinases (MMPs), a disintegrin and metalloproteases (ADAMs), and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTSs) plays a crucial role in the extracellular matrix (ECM) remodeling and degradation activities. A wide range of substrates of the MP family includes ECM components, chemokines, cell receptors, and growth factors. Metalloproteinases activities are tightly regulated by proteolytic activation and inhibition via their natural inhibitors, tissue inhibitors of metalloproteinases (TIMPs), and the imbalance of the activation and inhibition is responsible in progression or inhibition of several diseases, e.g., cancer, neurological disorders, and cardiovascular diseases. We provide an overview of the structure, function, and the multifaceted role of MMPs, ADAMs, and TIMPs in several diseases via their cellular functions such as proteolysis of other cell signaling factors, degradation and remodeling of the ECM, and other essential protease-independent interactions in the ECM. The significance of MP inhibitors targeting specific MMP or ADAMs with high selectivity is also discussed. Recent advances and techniques used in developing novel MP inhibitors and MP responsive drug delivery tools are also reviewed.

NF-ĸβ upregulates ADAMTS5 expression by direct binding after TNF-α treatment in OUMS-27 chondrosarcoma cell line.

Inflammation caused-aggrecan degradation is a critical event in the pathogenesis of osteoarthritis (OA). The aggrecanases like a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) are assumed to be key players in the aggrecan destruction. To develop the comprehensive therapy method for OA, it is essential to elucidate the activation mechanism of ADAMTS5 gene after stimulation of inflammatory cytokines like tumor necrosis factor-α (TNF-α). The cell lines of human chondrosarcoma (OUMS-27) and embryonic kidney (HEK293T) were incubated with tumor necrosis factor-α (TNF-α) for certain time periods, and the expression level of ADAMTS5 was measured in both mRNA and protein levels. Tissue-specific ADAMTS5 activation was founded to be induced after TNF-α treatment. Then, the constructs for the promoter region of ADAMTS5 were prepared and luciferase assay was conducted to understand the involvement mechanism of nuclear factor-kappa beta (NF-ĸβ) in ADAMTS5 activation. It was demonstrated that NF-ĸβ induces the ADAMTS5 expression level by directly binding the promoter region of ADAMTS5. Although the TNF-α blocker is used for OA treatment, the development of a more comprehensive treatment strategy is an urgent need. Our experimental data contributes in terms of selecting NF-ĸβ as a target molecule. Up to date, NF-ĸβ has been proven to involve in the ADAMTS5 up-regulation after several pro-inflammatory cytokines stimulation. In conclusion, our findings make important contributions to the knowledge about the roles of NF-ĸβ in ADAMTS5 activation under inflammatory conditions. So, NF-ĸβ could be considered to be a potential target for OA treatment.

Aggrecan Turnover in Women with Rheumatoid Arthritis Treated with TNF-α Inhibitors.

This study was performed to evaluate the effects of 15-month anti-tumor necrosis factor α (anti-TNF-α) therapy on the aggrecan turnover of female rheumatoid arthritis (RA) patients. Serum was obtained from healthy subjects and female RA patients treated with TNF-α inhibitors (TNFαI) in combination with methotrexate. We measured serum levels of aggrecan chondroitin sulfate 846 epitope (CS846), aggrecan fragments (AGC), disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) and 5 (ADAMTS-5), as well as their natural inhibitor, known as tissue inhibitor of matrix metalloproteinase-3 (TIMP-3), using immunoassay methods. Serum levels of CS846, AGC, ADAMTS-4, ADAMTS-5 and TIMP-3 were higher in female patients with RA before the treatment in comparison to healthy subjects. Ratio of ADAMTS-5 to TIMP-3 was significantly higher in RA women than in controls, whereas ADAMTS-4/TIMP-3 ratio did not differ from that in controls. During the anti-TNF-α therapy, the serum levels of 846 epitope increased, whereas levels of AGC decreased in female RA patients. Furthermore, 15 months of treatment with TNFαI downregulated serum levels of both ADAMTS, without any effect on TIMP-3 levels. These changes were accompanied by significantly reduced ratios of ADAMTS to TIMP-3. According to our results, anti-TNF-α therapy has a beneficial impact on aggrecan remodeling during RA.

ADAMTS-5 degraded cartilage increases tissue turnover in synovial membrane explants and stimulation is inhibited by the anti ADAMTS-5 nanobody, M6495

Purpose: Toll-like receptors are important for activating the innate immune system in response to foreign substances. In addition, it has been proposed that cartilage fragments in the joint may act TLR ligands in the joint, effectively driving inflammation and pain in osteoarthritis. The breakdown of cartilage is mediated by key enzymes: ADAMTS-5 (a disintegrin and metalloproteinase with thrombospondin motifs 5) and MMPs (matrix metalloproteinases). The aim of this study was to investigate the effect of ADAMTS-5 degraded cartilage fragments on tissue turnover in a synovial membrane explant model (SME).

How does GDP‐fucose get into the Endoplasmic Reticulum for O‐fucosylation of EGF Repeats and TSRs?

Fucose is a common monosaccharide found in glycan chains of all mammalian cells. Fucose is transferred from GDP‐fucose to glycoproteins by fucosyltransferases, resulting in terminal fucosylation of N‐linked glycans or mucin‐type O‐glycans, or direct modification of serine or threonine residues by Protein O‐fucosyltransferases (POFUT) 1 or 2. Defects in fucosylation can lead to developmental disorders or cancer. In particular, POFUT1 adds O‐fucose to Epidermal Growth Factor‐like (EGF) repeats of Notch receptors, while POFUT2 adds O‐fucose to Thrombospondin type 1 Repeats (TSRs) found in multiple cell‐surface and secreted proteins, including the A Disintegrin And Metalloproteinase with ThromboSpondin motifs (ADAMTS) family of extracellular proteases. Elimination of Pofut1 or Pofut2 results in early embryonic lethality in mice, indicating these two fucosylation pathways play essential roles in mouse development. Both POFUT1 and POFUT2 are located in the endoplasmic reticulum (ER), while fucosyltransferases involved in terminal fucosyaltion are localized in the trans‐Golgi. GDP‐fucose is synthesized in the cytoplasm either through a de novo or salvage pathway, and the GDP‐fucose is then transported into the lumen of the ER or Golgi for use by the fucosyltransferases. Currently two GDP‐fucose transporters, SLC35C1 and SLC35C2, have been identified, both of which are localized to the Golgi. It is unknown how GDP‐fucose is transported into the ER where Notch receptors and ADAMTS proteins are fucosylated. In order to uncover where the GDP‐fucose for POFUT1 and POFUT2 comes from, we have generated CRISPR‐Cas9 mutant cell lines in which fucosylation is impaired in two ways: 1. Inactivating GDP‐fucose biosynthetic enzymes from the salvage or de novo pathways; 2. Inactivating the GDP‐fucose transporters. HEK293T cells have proven to be an excellent model for fucosylation studies. All the fucose biosynthesis genes are normally expressed, and impaired fucosylation can be expected in knockout mutant cell lines. Using CRISPR‐Cas9 technology, the following genes have been knocked out: GMDS and TSTA3 of the de novo pathway, FUK and GFPP of the salvage pathway, and the GDP‐fucose transporters SLC35C1 and SLC35C2. O‐Fucosylation of EGF repeats and TSRs and terminal fucosylation of N‐linked glycans is being analyzed using Mass Spectrometry and lectin binding. Notch function is also being evaluated. These results should reveal whether a preferred biosynthetic pathway or transporter for different forms of fucosylation exists.Support or Funding InformationSupported by NIH grant GM061126.

Urolithin a attenuates IL-1\u03b2-induced inflammatory responses and cartilage degradation via inhibiting the MAPK/NF-\u03baB signaling pathways in rat articular chondrocytes

BackgroundOsteoarthritis (OA) is characterized by inflammation and extracellular matrix (ECM) degradation and is one of the most common chronic degenerative joint diseases that causes pain and disability in adults. Urolithin A (UA) has been widely reported for its anti-inflammatory properties in several chronic diseases. However, the effects of UA on OA remain unclear. The aim of the current study was to investigate the anti-inflammatory effects and mechanism of UA in interleukin-1β (IL-1β)-induced chondrocytes.ResultsNo marked UA cytotoxicity was noted, and UA protected cartilage from damage following IL-1β stimulation in micromasses. Moreover, UA promoted the expression of anabolic factors including Sox-9, Collagen II, and Aggrecan while inhibiting the expression of catabolic factors such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4) in rat chondrocytes. Protective effects of UA were also observed in ex vivo organ culture of articular cartilage. Mechanistically, IL-1β significantly activated and upregulated the expression of p-ERK 1/2, p-JNK, p-P38, and p-P65, while UA protected chondrocytes against IL-1β-induced injury by activating the mitogen-activated kinase (MAPK)/nuclear factor-κB (NF-κB) signaling pathways.ConclusionOur results provide the evidence that UA could attenuate IL-1β-induced cell injury in chondrocytes via its anti-inflammatory action. UA may be a promising therapeutic agent in the treatment of OA.

Genomic Landscape and Mutational Spectrum of ADAMTS Family Genes in Mendelian Disorders Based on Gene Evidence Review for Variant Interpretation

ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) are a family of multidomain extracellular protease enzymes with 19 members. A growing number of ADAMTS family gene variants have been identified in patients with various hereditary diseases. To understand the genomic landscape and mutational spectrum of ADAMTS family genes, we evaluated all reported variants in the ClinVar database and Human Gene Mutation Database (HGMD), as well as recent literature on Mendelian hereditary disorders associated with ADAMTS family genes. Among 1089 variants in 14 genes reported in public databases, 307 variants previously suggested for pathogenicity in Mendelian diseases were comprehensively re-evaluated using the American College of Medical Genetics and Genomics (ACMG) 2015 guideline. A total of eight autosomal recessive genes were annotated as being strongly associated with specific Mendelian diseases, including two recently discovered genes (ADAMTS9 and ADAMTS19) for their causality in congenital diseases (nephronophthisis-related ciliopathy and nonsyndromic heart valve disease, respectively). Clinical symptoms and affected organs were extremely heterogeneous among hereditary diseases caused by ADAMTS family genes, indicating phenotypic heterogeneity despite their structural and functional similarity. ADAMTS6 was suggested as presenting undiscovered pathogenic mutations responsible for novel Mendelian disorders. Our study is the first to highlight the genomic landscape of ADAMTS family genes, providing an appropriate genetic approach for clinical use.

The CRD of Frizzled 7 exhibits chondroprotective effects in osteoarthritis via inhibition of the canonical Wnt3a/β-catenin signaling pathway

Osteoarthritis (OA) is a chronic inflammatory joint disease without effective drugs. Frizzled 7 (FzD7) binds its ligand Wnt3a through an extracellular cysteine-rich domain (CRD) to transduce the canonical Wnt/β-catenin signaling pathway, which has been strongly implicated in OA pathogenesis. Effects of recombinant protein of FzD7 CRD on Wnt/β-catenin signaling and chondral destruction was evaluated in this study. Firstly, increased protein levels of FzD7, Wnt3a and β-catenin were detected in human OA cartilage implying that the canonical Wnt/β-catenin signaling mediated by Wnt3a and FzD7 executes an essential role in OA. Then we showed that FzD7 CRD antagonized the Wnt3a/β-catenin signaling pathway in a dose-dependent manner by binding Wnt3a. In addition, FzD7 CRD increased the expression of glycosaminoglycans (GAGs), Collagen II, aggrecan and reduced the expression of matrix metalloproteinase (MMP)-1, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5) in Wnt3a-stimulated human chondrocytes. Furthermore, a single intra-articular injection of the FzD7 CRD was efficacious in destabilization of the medial meniscus (DMM) mouse OA model, significantly improving Osteoarthritis Research Society International (OARSI) histology scores compared to mice treated with PBS. The results indicate that the FzD7 CRD exhibits chondroprotective effects by binding Wnt3a to suppress the Wnt3a/β-catenin signaling. Targeting the FzD7 CRD may be a novel therapy for the treatment of OA.

Proteolysis and cartilage development are activated in the synovium after surgical induction of post traumatic osteoarthritis.

Anterior cruciate ligament (ACL) transection surgery in the minipig induces post-traumatic osteoarthritis (PTOA) in a pattern similar to that seen in human patients after ACL injury. Prior studies have reported the presence of cartilage matrix-degrading proteases, such as Matrix metalloproteinase-1 (MMP-1) and A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), in the synovial fluid of injured or arthritic joints; however, the tissue origin of these proteases is unknown. The objective of this study was to identify transcriptional processes activated in the synovium after surgical induction of PTOA with ACL transection, and to determine if processes associated with proteolysis were enriched in the synovium after ACL transection. Unilateral ACL transection was performed in adolescent Yucatan minipigs and synovium samples were collected at 1, 5, 9, and 14 days post-injury. Transcriptome-wide gene expression levels were determined using bulk RNA-Sequencing in the surgical animals and control animals with healthy knees. The greatest number of transcripts with significant changes was observed 1 day after injury. These changes were primarily associated with cellular proliferation, consistent with measurements of increased cellularity of the synovium at the two-week time point. At five to 14 days, the expression of transcripts relating to proteolysis and cartilage development was significantly enriched. While protease inhibitor-encoding transcripts (TIMP2, TIMP3) represented the largest fraction of protease-associated transcripts in the uninjured synovium, protease-encoding transcripts (including MMP1, MMP2, ADAMTS4) predominated after surgery. Cartilage development-associated transcripts that are typically not expressed by synovial cells, such as ACAN and COMP, were enriched in the synovium following ACL-transection. The upregulation in both catabolic processes (proteolysis) and anabolic processes (cartilage development) suggests that the synovium plays a complex, balancing role in the early response to PTOA induction.

Scutellarin Attenuates the IL-1β-Induced Inflammation in Mouse Chondrocytes and Prevents Osteoarthritic Progression.

Osteoarthritis (OA) is a chronic degenerative disease wherein the articular cartilage exhibits inflammation and degradation. Scutellarin (SCU) is a flavonoid glycoside with a range of pharmacological activities, as shown in previous studies demonstrating its anti-inflammatory activity. How SCU impacts the progression of OA, however, has not been explored to date. Herein, we assessed the impact of SCU on murine chondrocytes in an OA model system. In in vitro assays, we measured chondrocyte expression of key OA-associated factors such as matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) via qRT-PCR and Western blotting, the expression of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E2 (PGE2) were detected by qRT-PCR. Our results showed that the downregulation of MMP-13, ADAMTS-5, COX-2, and iNOS expression by SCU and the overproduction of IL-6, TNF-α, and PGE2 induced by IL-1β were all inhibited by SCU in a concentration-dependent manner. Moreover, SCU was able to reverse aggrecan and collagen II degradation and nuclear factor-κB (NF-κB) and nuclear factor erythroid-derived 2-like 2 (Nrf2) signaling pathway activation both in vivo and in vitro. We further used a destabilization of the medial meniscus (DMM) murine model of OA to explore the therapeutic benefits of SCU in vivo. Together, our findings suggest SCU to be a potentially valuable therapeutic agent useful for treating OA.