Fibronectin fibers are highly tensed in healthy organs in contrast to tumors and virus-infected lymph nodes.

The extracellular matrix (ECM) acts as reservoir for a plethora of growth factors and cytokines some of which are hypothesized to be regulated by ECM fiber tension. Yet, ECM fiber tension has never been mapped in healthy versus diseased organs. Using our recently developed tension nanoprobe derived from the bacterial adhesin FnBPA5, which preferentially binds to structurally relaxed fibronectin fibers, we discovered here that fibronectin fibers are kept under high tension in selected healthy mouse organs. In contrast, tumor tissues and virus-infected lymph nodes exhibited a significantly higher content of relaxed or proteolytically cleaved fibronectin fibers. This demonstrates for the first time that the tension of ECM fibers is significantly reduced upon pathological tissue transformations. This has wide implications, as the active stretching of fibronectin fibers adjusts critical cellular niche parameters and thereby tunes the reciprocal cell-ECM crosstalk. Mapping the tensional state of fibronectin fibers opens novel and unexpected diagnostic opportunities.

Switching from sitagliptin to liraglutide to manage patients with type 2 diabetes in the UK: A long-term cost-effectiveness analysis.

AIMS: The recent LIRA-SWITCH trial showed that switching from sitagliptin 100 mg to liraglutide 1.8 mg led to statistically significant and clinically relevant improvements in glycated haemoglobin (HbA1C) and body mass index (BMI). Based on these findings, the aim of the present study was to assess the long-term cost-effectiveness of switching from sitagliptin to liraglutide in patients with type 2 diabetes in the UK. MATERIALS AND METHODS: The IQVIA CORE Diabetes Model Version 8.5+ was used to project costs and clinical outcomes over patients' lifetimes. Baseline cohort characteristics and treatment effects were derived from the LIRA-SWITCH trial. Future costs and clinical benefits were discounted at 3.5% annually. Costs were accounted in pounds sterling (GBP) and expressed in 2016 values. One-way and probabilistic sensitivity analyses were performed. RESULTS: Model projections showed improved quality-adjusted life expectancy for patients with poorly controlled HbA1c upon switching from sitagliptin to liraglutide, compared with continuing sitagliptin treatment (9.18 vs 9.02 quality-adjusted life years [QALYs]). Treatment switching was associated with increased overall costs (GBP 24737 vs GBP 22362). Higher pharmacy costs were partially offset by reduced diabetes-related complication costs in patients who switched to liraglutide. Switching to liraglutide was associated with an incremental cost-effectiveness ratio of GBP 15423 per QALY gained vs continuing with sitagliptin treatment. CONCLUSIONS: Switching from sitagliptin 100 mg to liraglutide 1.8 mg in patients with poor glycaemic control was projected to improve clinical outcomes and is likely to be considered cost-effective in the UK setting and, therefore, a good use of limited NHS resources.

Novel peptide probes to assess the tensional state of fibronectin fibers in cancer.

Transformations of extracellular matrix (ECM) accompany pathological tissue changes, yet how cell-ECM crosstalk drives these processes remains unknown as adequate tools to probe forces or mechanical strains in tissues are lacking. Here, we introduce a new nanoprobe to assess the mechanical strain of fibronectin (Fn) fibers in tissue, based on the bacterial Fn-binding peptide FnBPA5. FnBPA5 exhibits nM binding affinity to relaxed, but not stretched Fn fibers and is shown to exhibit strain-sensitive ECM binding in cell culture in a comparison with an established Fn-FRET probe. Staining of tumor tissue cryosections shows large regions of relaxed Fn fibers and injection of radiolabeled 111In-FnBPA5 in a prostate cancer mouse model reveals specific accumulation of 111In-FnBPA5 in tumor with prolonged retention compared to other organs. The herein presented approach enables to investigate how Fn fiber strain at the tissue level impacts cell signaling and pathological progression in different diseases.

Sulfated hyaluronan alters fibronectin matrix assembly and promotes osteogenic differentiation of human bone marrow stromal cells.

Extracellular matrix (ECM) composition and structural integrity is one of many factors that influence cellular differentiation. Fibronectin (FN) which is in many tissues the most abundant ECM protein forms a unique fibrillary network. FN homes several binding sites for sulfated glycosaminoglycans (sGAG), such as heparin (Hep), which was previously shown to influence FN conformation and protein binding. Synthetically sulfated hyaluronan derivatives (sHA) can serve as model molecules with a well characterized sulfation pattern to study sGAG-FN interaction. Here is shown that the low-sulfated sHA (sHA1) interacts with FN and influences fibril assembly. The interaction of FN fibrils with sHA1 and Hep, but not with non-sulfated HA was visualized by immunofluorescent co-staining. FRET analysis of FN confirmed the presence of more extended fibrils in human bone marrow stromal cells (hBMSC)-derived ECM in response to sHA1 and Hep. Although both sHA1 and Hep affected FN conformation, exclusively sHA1 increased FN protein level and led to thinner fibrils. Further, only sHA1 had a pro-osteogenic effect and enhanced the activity of tissue non-specific alkaline phosphatase. We hypothesize that the sHA1-triggered change in FN assembly influences the entire ECM network and could be the underlying mechanism for the pro-osteogenic effect of sHA1 on hBMSC.