Evaluation of 3D Human Intestinal Organoids as a Platform for EV-A71 Antiviral Drug Discovery.

Enteroviruses are a leading cause of upper respiratory tract, gastrointestinal, and neurological infections. Management of enterovirus-related diseases has been hindered by the lack of specific antiviral treatment. The pre-clinical and clinical development of such antivirals has been challenging, calling for novel model systems and strategies to identify suitable pre-clinical candidates.

Identification of regulators of the myofibroblast phenotype of primary dermal fibroblasts from early diffuse systemic sclerosis patients.

Systemic sclerosis (SSc or scleroderma) is an auto-immune disease characterized by skin fibrosis. While primary cells from patients are considered as a unique resource to better understand human disease biology, the effect of in vitro culture on these cells and their evaluation as a platform to identify disease regulators remain poorly characterized. The goal of our studies was to provide insights into the utility of SSc dermal fibroblast primary cells for therapeutic target discovery.

Antisense Long Non-Coding RNAs Are Deregulated in Skin Tissue of Patients with Systemic Sclerosis.

Systemic sclerosis is an autoimmune disease characterized by fibrosis of skin and multiple organs of which the pathogenesis is poorly understood. We studied differentially expressed coding and non-coding genes in relation to systemic sclerosis pathogenesis with a specific focus on antisense non-coding RNAs. Skin biopsy-derived RNAs from 14 early systemic sclerosis patients and six healthy individuals were sequenced with ion-torrent and analyzed using DEseq2.

PET-CT imaging with [(18)F]-gefitinib to measure Abcb1a/1b (P-gp) and Abcg2 (Bcrp1) mediated drug-drug interactions at the murine blood-brain barrier.

Introduction: The efflux transporters P-glycoprotein (P-gp, ABCB1) and breast cancer resistance protein (BCRP, ABCG2) are expressed at the blood-brain barrier (BBB), and can limit the access of a wide range of drugs to the brain. In this study we developed a PET-CT imaging method for non-invasive, quantitative analysis of the effect of ABCB1 and ABCG2 on brain penetration of the anti-cancer drug gefitinib, and demonstrated the applicability of this method for identification and quantification of potential modulators of ABCB1 and ABCB2 using the dual inhibitor elacridar.

Methods: In vitro cellular accumulation studies with [(14)C]-gefitinib were conducted in LLC-PK1, MDCKII, and the corresponding ABCB1/Abcb1a and ABCG2/Abcg2 overexpressing cell lines.

Elevation of cartilage AGEs does not accelerate initiation of canine experimental osteoarthritis upon mild surgical damage.

Osteoarthritis is a highly prevalent disease, age being the main risk factor. The age-related accumulation of advanced-glycation-endproducts (AGEs) adversely affects the mechanical and biochemical properties of cartilage. The hypothesis that accumulation of cartilage AGEs in combination with surgically induced damage predisposes to the development of osteoarthritis was tested in vivo in a canine model.

Infrapatellar fat pad of patients with end-stage osteoarthritis inhibits catabolic mediators in cartilage.

Objective: Adipose tissue is known to release inflammatory cytokines and growth factors. In this exploratory study, the authors examined whether the infrapatellar fat pad (IPFP) closely located to cartilage in the knee joint can affect cartilage metabolism. In addition, the authors analysed whether the macrophage types present in IPFP could explain the effect on cartilage.

Automated synthesis of [18F]gefitinib on a modular system.

In recent years, [(18)F]gefitinib PET has successfully been employed for a number of applications ranging from oncology to in vivo studies of drug transporter proteins. We here report a reliable, automated procedure for routine synthesis of this radiotracer on an Eckert and Ziegler modular system. The 3-step radiosynthesis followed by preparative HPLC-purification provided [(18)F]gefitinib in 17.

Integration of efficacy, pharmacokinetic and safety assessment of interleukin-1 receptor antagonist in a preclinical model of arthritis.

Pharmacokinetic properties and safety profile of a drug are likely influenced by the disease state of a patient. In this study, we investigated the influence of arthritic processes on pharmacokinetics and immunotoxicity of interleukin-1 receptor antagonist (Anakinra) in the rat adjuvant arthritis model. Anakinra dose-dependently suppressed joint inflammation and degradation as demonstrated by reduced clinical arthritis score, paw thickness, synovial infiltration and bone degradation.

Soluble biomarkers of cartilage and bone metabolism in early proof of concept trials in psoriatic arthritis: effects of adalimumab versus placebo.

Background: There is growing interest in soluble biomarkers that could be used on the group level for screening purposes in small proof of principle studies during early drug development. We investigated early changes in serum levels of several candidate biomarkers involved in cartilage and bone metabolism following the initiation of adalimumab as a prototypic active treatment in psoriatic arthritis (PsA) compared to placebo.

Materials And Methods: Twenty-four PsA patients were randomized to receive either adalimumab 40 mg s.

Comprehensive LC-MS E lipidomic analysis using a shotgun approach and its application to biomarker detection and identification in osteoarthritis patients.

A fast and robust method for lipid profiling utilizing liquid chromatography coupled with mass spectrometry has been demonstrated and validated for the analysis of human plasma. This method allowed quantification and identification of lipids in human plasma using parallel alternating low energy and high energy collision spectral acquisition modes. A total of 275 [corrected] lipids were identified and quantified (as relative concentrations) in both positive and negative ion electrospray ionization mode.

Similarities and discrepancies in subchondral bone structure in two differently induced canine models of osteoarthritis.

In osteoarthritis (OA), cartilage degradation is accompanied by subchondral bone changes. The pathogenesis and physiology of bone changes in OA are still unclear. The changes in subchondral bone architecture and cartilage damage were compared in differently induced experimental models of OA.

Feasibility of electrodialysis as a fast and selective sample preparation method for the profiling of low-abundant peptides in biofluids.

Considerable interest exists in endogenous peptides as potential biomarkers, since they act as signaling molecules and are formed by degradation of proteins. A crucial step in the profiling of these peptides is the sample preparation, which aims to enrich the low-abundant peptides, while removing interfering matrix compounds. In a feasibility study we examined the suitability of electrodialysis (ED) for this purpose.

Association between weight or body mass index and hand osteoarthritis: a systematic review.

Objective: To investigate the association between weight or body mass index (BMI) and the development of hand osteoarthritis.

Methods: Systematic review of observational studies. Medical databases were searched up to April 2008.

Does loading influence the severity of cartilage degeneration in the canine Groove-model of OA?

Many animal models are used to study osteoarthritis (OA). In these models the role of joint loading in the development of OA is not fully understood. We studied the effect of loading on the development of OA in the canine Groove-model.

TGFbeta affects collagen cross-linking independent of chondrocyte phenotype but strongly depending on physical environment.

Transforming growth factor beta (TGFbeta) is often used in cartilage tissue engineering to increase matrix formation by cells with various phenotypes. However, adverse effects of TGFbeta, such as extensive crosslinking in cultured fibroblasts, have also been reported. Our goal was to study effects of TGFbeta on collagen cross-linking and evaluating the role of cellular phenotype and physical environment.

Inhibition of glycosaminoglycan incorporation influences collagen network formation during cartilage matrix production.

To understand cartilage degenerative diseases and improve repair procedures, we investigate the influence of glycosaminoglycans (GAGs) on cartilage matrix biochemistry and functionality. Bovine articular chondrocytes were cultured in alginate beads with(out) para-nitrophenyl-beta-d-xyloside (PNPX) to inhibit GAG incorporation into newly formed proteoglycans. As expected, GAG deposition in alginate beads decreased with increasing PNPX concentration.

Biochemical markers of bone turnover and their association with bone marrow lesions.

Introduction: Our objective was to determine whether markers of bone resorption and formation could serve as markers for the presence of bone marrow lesions (BMLs).

Methods: We conducted an analysis of data from the Boston Osteoarthritis of the Knee Study (BOKS). Knee magnetic resonance images were scored for BMLs using a semiquantitative grading scheme.

The canine bilateral groove model of osteoarthritis.

In studies aimed at local treatment of experimental osteoarthritis (OA) it is optimal to have an internal (untreated) OA control. Such an approach excludes interanimal variation, and allows paired statistical evaluation of treatment efficacy. For this purpose, we developed and characterized a bilateral version of the canine Groove model.

Collagen turnover in normal and degenerate human intervertebral discs as determined by the racemization of aspartic acid.

Knowledge of rates of protein turnover is important for a quantitative understanding of tissue synthesis and catabolism. In this work, we have used the racemization of aspartic acid as a marker for the turnover of collagen obtained from healthy and pathological human intervertebral disc matrices. We measured the ratio of the d- and l-isomers in collagen extracted from these tissues as a function of age between 16 and 77 years.

Cartilage markers and their association with cartilage loss on magnetic resonance imaging in knee osteoarthritis: the Boston Osteoarthritis Knee Study.

We used data from a longitudinal observation study to determine whether markers of cartilage turnover could serve as predictors of cartilage loss on magnetic resonance imaging (MRI). We conducted a study of data from the Boston Osteoarthritis of the Knee Study (BOKS), a completed natural history study of knee osteoarthritis (OA). All subjects in the study met American College of Rheumatology criteria for knee OA.

Profiling of endogenous peptides in human synovial fluid by NanoLC-MS: method validation and peptide identification.

Synovial fluid potentially contains markers for early diagnosis and disease progression in degenerative joint diseases such as osteoarthritis. Here, a method is described for profiling endogenous peptides in human synovial fluid, using ultrafiltration, solid-phase extraction, nanoscale liquid chromatography, and high-resolution mass spectrometry. Synovial fluid is characterized by its high viscosity, caused by the presence of the lubricant hyaluronic acid.

Achilles tendinosis: changes in biochemical composition and collagen turnover rate.

Background: Understanding biochemical and structural changes of the extracellular matrix in Achilles tendinosis might be important for developing mechanism-based therapies.

Hypothesis: In Achilles tendinosis, changes occur in biochemical composition and collagen turnover rate.

Study Design: Descriptive laboratory study.

Exposure of human cartilage tissue to low concentrations of blood for a short period of time leads to prolonged cartilage damage: an in vitro study.

Objective: Joint bleeding, or hemarthrosis, leads in time to severe joint damage. This study was carried out to test the in vitro thresholds of exposure time and concentration that lead to irreversible joint damage, to add to the discussion on the usefulness of aspiration of the joint after a hemorrhage.

Methods: Explants of healthy human articular cartilage tissue were cultured in the presence or absence of 50% (volume/volume) blood for 1, 2, 3, or 4 days or in the presence of 0%, 5%, 10%, 20%, 30%, or 50% (v/v) blood for 4 days, followed by a 12-day period of recovery after withdrawal of blood.

Transition of healthy to diseased synovial tissue in rheumatoid arthritis is associated with gain of mesenchymal/fibrotic characteristics.

The healthy synovial lining layer consists of a single cell layer that regulates the transport between the joint cavity and the surrounding tissue. It has been suggested that abnormalities such as somatic mutations in the p53 tumor-suppressor gene contribute to synovial hyperplasia and invasion in rheumatoid arthritis (RA). In this study, expression of epithelial markers on healthy and diseased synovial lining tissue was examined.

Corticosteroids reduce the tensile strength of isolated collagen fascicles.

Background: Overuse tendon injuries are frequent. Corticosteroid injections are commonly used as treatment, although their direct effects on the material properties of the tendon are poorly understood.

Purpose: To examine the influence of corticosteroids on the tensile strength of isolated collagen fascicles.