Differences in decorin and biglycan expression in patients with gastric ulcer healing

Tissue extracellular matrix hydrogels as alternatives to Matrigel for culturing gastrointestinal organoids

Matrigel, a mouse tumor extracellular matrix protein mixture, is an indispensable component of most organoid tissue culture. However, it has limited the utility of organoids for drug development and regenerative medicine due to its tumor-derived origin, batch-to-batch variation, high cost, and safety issues. Here, we demonstrate that gastrointestinal tissue-derived extracellular matrix hydrogels are suitable substitutes for Matrigel in gastrointestinal organoid culture. We found that the development and function of gastric or intestinal organoids grown in tissue extracellular matrix hydrogels are comparable or often superior to those in Matrigel. In addition, gastrointestinal extracellular matrix hydrogels enabled long-term subculture and transplantation of organoids by providing gastrointestinal tissue-mimetic microenvironments. Tissue-specific and age-related extracellular matrix profiles that affect organoid development were also elucidated through proteomic analysis. Together, our results suggest that extracellular matrix hydrogels derived from decellularized gastrointestinal tissues are effective alternatives to the current gold standard, Matrigel, and produce organoids suitable for gastrointestinal disease modeling, drug development, and tissue regeneration.

Oncosuppressive roles of decorin through regulation of multiple receptors and diverse signaling pathways

Decorin is a stromal-derived prototype member of the small leucine-rich proteoglycan gene family. In addition to its functions as a regulator of collagen fibrillogenesis and TGF-β activity soluble decorin acts as a pan-receptor tyrosine kinase (RTK) inhibitor. Decorin binds to various RTKs including EGFR HER2 HGFR/Met VEGFR2 TLR and IGFR. Although the molecular mechanism for the action of decorin on these receptors is not entirely elucidated overall decorin evokes transient activation of these receptors with suppression of downstream signaling cascades culminating in growth inhibition followed by their physical downregulation via caveosomal internalization and degradation. In the case of Met decorin leads to decreased β-catenin signaling pathway and growth suppression. As most of these RTKs are responsible for providing a growth advantage to cancer cells the result of decorin treatment is oncosuppression. Another decorin-driven mechanism to restrict cancer growth and dissemination is by impeding angiogenesis via vascular endothelial growth factor receptor 2 (VEGFR2) and the concurrent activation of protracted endothelial cell autophagy. In this review we will dissect the multiple roles of decorin in cancer biology and its potential use as a next-generation protein-based adjuvant therapy to combat cancer.

The Charming World of the Extracellular Matrix: A Dynamic and Protective Network of the Intestinal Wall

The intestinal extracellular matrix (ECM) represents a complex network of proteins that not only forms a support structure for resident cells but also interacts closely with them by modulating their phenotypes and functions. More than 300 molecules have been identified, each of them with unique biochemical properties and exclusive biological functions. ECM components not only provide a scaffold for the tissue but also afford tensile strength and limit overstretch of the organ. The ECM holds water, ensures suitable hydration of the tissue, and participates in a selective barrier to the external environment. ECM-to-cells interaction is crucial for morphogenesis and cell differentiation, proliferation, and apoptosis. The ECM is a dynamic and multifunctional structure. The ECM is constantly renewed and remodeled by coordinated action among ECM-producing cells, degrading enzymes, and their specific inhibitors. During this process, several growth factors are released in the ECM, and they, in turn, modulate the deposition of new ECM. In this review, we describe the main components and functions of intestinal ECM and we discuss their role in maintaining the structure and function of the intestinal barrier. Achieving complete knowledge of the ECM world is an important goal to understand the mechanisms leading to the onset and the progression of several intestinal diseases related to alterations in ECM remodeling.

The intestinal tissue homeostasis - the role of extracellular matrix remodeling in inflammatory bowel disease

Introduction: Extracellular matrix (ECM) remodeling of the intestinal tissue is important in inflammatory bowel disease (IBD) due to the extensive mucosal remodeling. There are still gaps in our knowledge as to how ECM remodeling is related to intestinal epithelium homeostasis and healing of the intestinal mucosa.Areas covered: The aim of this review is to highlight the importance of the ECM in relation to the pathogenesis of IBD, while addressing basement membrane and interstitial matrix remodeling, and the processes of wound healing of the intestinal tissue in IBD.Expert opinion: In IBD, basement membrane remodeling may reflect the integrity of the intestinal epithelial-cell homeostasis. The interstitial matrix remodeling is associated with deep inflammation such as the transmural inflammation as seen in fistulas and intestinal fibrosis leading to fibrostenotic strictures, in patients with CD. The interplay between wound healing processes and ECM remodeling also affects the tissue homeostasis in IBD. The interstitial matrix, produced by fibroblasts, holds a very different biology as compared to the epithelial basement membrane in IBD. In combination with integration of wound healing, quantifying the interplay between damage and repair to these sub compartments may provide essential information in IBD patient profiling, mucosal healing and disease management.

Down-regulation of decorin, a transforming growth factor-beta modulator, is associated with scarless fetal wound healing

PURPOSE

Transforming growth factor beta (TGF-beta) bioactivity has been implicated as a potential regulator of the transition from scarless healing to scar formation in fetal wounds. Decorin is an extracellular matrix proteoglycan that regulates TGF-beta bioactivity and assists in collagen fibrillogenesis. To determine its role in scarless repair, the authors examined decorin expression in fetal fibroblasts, skin, and wounds.

METHODS

A single, full-thickness, 2-mm open wound was created on the dorsal surface of fetal rats at 16.5 days (E16) and 18.5 days (E18) gestational age (term, 21.5 days [E21]). Wounds were harvested at 24 and 72 hours (n = 12 wounds per time-point). Nonwounded fetal skin at E17, E19, and E21 was harvested for analysis of decorin expression during skin development and as controls for wounds. In addition, fetal (E14, E18) and adult dermal fibroblasts were cultured for in vitro analysis. Reduced-cycle, specific primer, reverse transcriptase polymerase chain reaction was performed to quantitate decorin expression.

RESULTS

Decorin expression increased rapidly with increasing gestational age in both fetal fibroblasts and skin. Expression was increased 22-fold in E18 fibroblasts (P <.002) and 300-fold in adult fibroblasts (P <.001) compared with E14 fibroblasts. In skin, expression increased 74% (P <.01) during the fetal wound healing transition period between E17 and E19. However, in E16 wounds (scarless), decorin expression decreased 59% (P <.006) at 24 hours and 45% (P <.02) at 72 hours. Decorin expression did not change in E18 (scar) wounds at 24 and 72 hours (P >.05).

CONCLUSIONS

Early gestation fetal fibroblasts and fetal skin express decorin at lower levels than late gestation fetal and adult fibroblasts and skin. Decorin expression is down-regulated in scarless (E16) compared with scar (E18) wounds. Thus, increased decorin expression is associated with both skin development and scar formation. Conversely, decreased decorin expression is associated with scarless repair.

Lumican and decorin are differentially expressed in human breast carcinoma

Previous studies have shown that lumican is expressed and increased in the stroma of breast tumours. Lumican expression has now been examined relative to other members of the small leucine-rich proteoglycan gene family in normal and neoplastic breast tissues, to begin to determine its role in breast tumour progression. Western blot study showed that lumican protein is highly abundant relative to decorin, while biglycan and fibromodulin are only detected occasionally in breast tissues (n=15 cases). Further analysis of lumican and decorin expression performed in matched normal and tumour tissues by in situ hybridization showed that both mRNAs were expressed by similar fibroblast-like cells adjacent to epithelium. However, lumican mRNA expression was significantly increased in tumours (n=34, p<0.0001), while decorin mRNA was decreased (p=0.0002) in neoplastic relative to adjacent normal stroma. This was accompanied by a significant increase in lumican protein (n=12, p=0.0122), but not decorin. Further evidence of altered lumican expression in breast cancer was manifested by discordance between lumican mRNA and protein localization in some regions of tumours but not in adjacent morphologically normal tissues. It is concluded that lumican is the most abundant of these proteoglycans in breast tumours and that lumican and decorin are inversely regulated in association with breast tumourigenesis.