Matrix metalloproteinases in intestinal fibrosis.

Intestinal fibrosis is a common complication in patients with inflammatory bowel disease [IBD], in particular Crohn's disease [CD]. Unfortunately, at present intestinal fibrosis is not yet preventable, and cannot be treated by interventions other than surgical removal. Intestinal fibrosis is characterized by excessive accumulation of extracellular matrix [ECM], which is caused by activated fibroblasts and smooth muscle cells.

Verteporfin ameliorates fibrotic aspects of Dupuytren's disease nodular fibroblasts irrespective the activation state of the cells.

Dupuytren's disease is a chronic, progressive fibroproliferative condition of the hand fascia which results in digital contraction. So far, treatments do not directly interfere with the (myo)fibroblasts that are responsible for the formation of the collagen-rich cords and its contraction. Here we investigated whether verteporfin (VP) is able to inhibit the activation and subsequent differentiation of DD nodular fibroblasts into myofibroblasts.

Macromolecular Crowding as a Tool to Screen Anti-fibrotic Drugs: The Scar-in-a-Jar System Revisited.

An unsolved therapeutic problem in fibrosis is the overproduction of collagen. In order to screen the effect of anti-fibrotic drugs on collagen deposition, the Scar-in-a-Jar approach has been introduced about a decade ago. With macromolecular crowding a rapid deposition of collagen is seen, resulting in a substantial decrease in culture time, but the system has never been tested in an adequate way.

Intestinal stenosis in Crohn's disease shows a generalized upregulation of genes involved in collagen metabolism and recognition that could serve as novel anti-fibrotic drug targets.

Background And Aims: Crohn's disease (CD) can be complicated by intestinal fibrosis. Pharmacological therapies against intestinal fibrosis are not available. The aim of this study was to determine whether pathways involved in collagen metabolism are upregulated in intestinal fibrosis, and to discuss which drugs might be suitable to inhibit excessive extracellular matrix formation targeting these pathways.

KRAB-Induced Heterochromatin Effectively Silences Gene Expression in Somatic Cells and is Resilient to TGFβ1 Activation.

Epigenetic editing, an emerging technique used for the modulation of gene expression in mammalian cells, is a promising strategy to correct disease-related gene expression. Although epigenetic reprogramming results in sustained transcriptional modulation in several in vivo models, further studies are needed to develop this approach into a straightforward technology for effective and specific interventions. Important goals of current research efforts are understanding the context-dependency of successful epigenetic editing and finding the most effective epigenetic effector(s) for specific tasks.

Predictive Value of Precision-Cut Kidney Slices as an Ex Vivo Screening Platform for Therapeutics in Human Renal Fibrosis.

Animal models are a valuable tool in preclinical research. However, limited predictivity of human biological responses in the conventional models has stimulated the search for reliable preclinical tools that show translational robustness. Here, we used precision-cut kidney slices (PCKS) as a model of renal fibrosis and investigated its predictive capacity for screening the effects of anti-fibrotics.

Inhibition of tyrosine kinase receptor signaling attenuates fibrogenesis in an ex vivo model of human renal fibrosis.

Poor translation from animal studies to human clinical trials is one of the main hurdles in the development of new drugs. Here, we used precision-cut kidney slices (PCKS) as a translational model to study renal fibrosis and to investigate whether inhibition of tyrosine kinase receptors, with the selective inhibitor nintedanib, can halt fibrosis in murine and human PCKS. We used renal tissue of murine and human origins to obtain PCKS.

Exploring organ-specific features of fibrogenesis using murine precision-cut tissue slices.

Fibrosis is the hallmark of pathologic tissue remodelling in most chronic diseases. Despite advances in our understanding of the mechanisms of fibrosis, it remains uncured. Fibrogenic processes share conserved core cellular and molecular pathways across organs.

Glimpses into the molecular pathogenesis of Peyronie's disease.

Peyronie's disease (PD) is a fibroproliferative disease of the penis. Since little is known about the molecular pathogenesis of PD, we compared the biochemical make-up of PD plaques with normal tunica albuginea to clarify pathological processes in the scarred tissue. Protein and mRNA levels were measured in plaques and in unaffected pieces of the tunica albuginea.

Collagen cross-linking mediated by lysyl hydroxylase 2: an enzymatic battlefield to combat fibrosis.

The hallmark of fibrosis is an excessive accumulation of collagen, ultimately leading to organ failure. It has become evident that the deposited collagen also exhibits qualitative modifications. A marked modification is the increased cross-linking, leading to a stabilization of the collagen network and limiting fibrosis reversibility.

Verteporfin as a Medical Treatment in Peyronie's Disease.

Introduction: In Europe and the United States, verteporfin (Visudyne; VP) is registered and used in treating macular degeneration. Research showed that VP decreased expression of fibrotic genes in fibroblasts collected from nodules of patients suffering from Dupuytren's disease, plausibly by de-activating transcription in the Yes Activated Protein (YAP) pathway.

Aim: To analyze the effect of VP on myofibroblasts cultured from Peyronie's disease (PD) plaques.

αII-spectrin and βII-spectrin do not affect TGFβ1-induced myofibroblast differentiation.

Mechanosensing of fibroblasts plays a key role in the development of fibrosis. So far, no effective treatments are available to treat this devastating disorder. Spectrins regulate cell morphology and are potential mechanosensors in a variety of non-erythroid cells, but little is known about the role of spectrins in fibroblasts.

Ascorbic acid promotes a TGF1-induced myofibroblast phenotype switch.

l-Ascorbic acid (AA), generally known as vitamin C, is a crucial cofactor for a variety of enzymes, including prolyl-3-hydroxylase (P3H), prolyl-4-hydroxylase (P4H), and lysyl hydroxylase (LH)-mediated collagen maturation. Here, we investigated whether AA has additional functions in the regulation of the myofibroblast phenotype, besides its function in collagen biosynthesis. We found that AA positively influences TGF1-induced expression of , , and Moreover, we demonstrated that AA promotes SMA stress fiber formation as well as the synthesis and deposition of collagens type I and IV Additionally, AA amplified the contractile phenotype of the myofibroblasts, as seen by increased contraction of a 3D collagen lattice.

Molecular insights into prolyl and lysyl hydroxylation of fibrillar collagens in health and disease.

Collagen is a macromolecule that has versatile roles in physiology, ranging from structural support to mediating cell signaling. Formation of mature collagen fibrils out of procollagen α-chains requires a variety of enzymes and chaperones in a complex process spanning both intracellular and extracellular post-translational modifications. These processes include modifications of amino acids, folding of procollagen α-chains into a triple-helical configuration and subsequent stabilization, facilitation of transportation out of the cell, cleavage of propeptides, aggregation, cross-link formation, and finally the formation of mature fibrils.

FACTORS ASSOCIATED WITH PENTOSIDINE ACCUMULATION IN THE HUMAN VITREOUS.

Purpose: To explore factors associated with pentosidine accumulation in the human vitreous.

Methods: Vitreous samples were obtained during trans pars plana vitrectomy for macular hole or rhegmatogenous retinal detachment. Patient characteristics included age, gender, and diabetes mellitus.

Matrix and cell phenotype differences in Dupuytren's disease.

Background: Dupuytren's disease is a fibroproliferative disease of the hand and fingers, which usually manifests as two different phenotypes within the same patient. The disease first causes a nodule in the palm of the hand, while later, a cord develops, causing contracture of the fingers.

Results: We set out to characterize the two phenotypes by comparing matched cord and nodule tissue from ten Dupuytren's patients.

Disentangling mechanisms involved in collagen pyridinoline cross-linking: The immunophilin FKBP65 is critical for dimerization of lysyl hydroxylase 2.

Collagens are subjected to extensive posttranslational modifications, such as lysine hydroxylation. Bruck syndrome (BS) is a connective tissue disorder characterized at the molecular level by a loss of telopeptide lysine hydroxylation, resulting in reduced collagen pyridinoline cross-linking. BS results from mutations in the genes coding for lysyl hydroxylase (LH) 2 or peptidyl-prolyl cis-trans isomerase (PPIase) FKBP65.

Ultrastructural aspects of foreign body giant cells generated on different substrates.

Implantation of biomaterials into the body, e.g. for tissue engineering purposes, induces a material-dependent inflammatory response called the foreign body reaction (FBR).

3,4-Dihydroxy-L-Phenylalanine as a Novel Covalent Linker of Extracellular Matrix Proteins to Polyacrylamide Hydrogels with a Tunable Stiffness.

Cells acquire mechanical information from their surrounding and convert this into biochemical activity. The concept and mechanism behind this cellular mechanosensing and mechanotransduction are often studied by means of two-dimensional hydrogels. Polyacrylamide hydrogels (PAAMs) offer chemical, mechanical, and optical advantages but due to their inert surface do not allow protein and cell adherence.

Further evidence of the involvement of the Wnt signaling pathway in Dupuytren's disease.

Genetic background plays an important role in the development of Dupuytren's disease. A genome-wide association study (GWAS) showed that nine loci are associated with the disease, six of which contain genes that are involved in Wnt signaling (WNT2, WNT4, WNT7B, RSPO2, SFRP4, SULF1). To obtain insight in the role of these genes, we performed expression studies on affected and unaffected patient's tissues.

Wnt pathway in Dupuytren disease: connecting profibrotic signals.

A role of Wnt signaling in Dupuytren disease, a fibroproliferative disease of the hand and fingers, has not been fully elucidated. We examined a large set of Wnt pathway components and signaling targets and found significant dysregulation of 41 Wnt-related genes in tissue from the Dupuytren nodules compared with patient-matched control tissue. A large proportion of genes coding for Wnt proteins themselves was downregulated.

YAP1 Is a Driver of Myofibroblast Differentiation in Normal and Diseased Fibroblasts.

Dupuytren disease is a fibrotic disorder characterized by contraction of myofibroblast-rich cords and nodules in the hands. The Hippo member Yes-associated protein 1 (YAP1) is activated by tissue stiffness and the profibrotic transforming growth factor-β1, but its role in cell fibrogenesis is yet unclear. We hypothesized that YAP1 regulates the differentiation of dermal fibroblasts into highly contractile myofibroblasts and that YAP1 governs the maintenance of a myofibroblast phenotype in primary Dupuytren cells.