Downregulation Of Decorin Research Articles

Decreased differentiation capacity and altered expression of extracellular matrix components in irradiation-mediated senescent human breast adipose-derived stem cells.

Radiotherapy is widely used for the treatment of breast cancer. However, we have shown that ionizing radiation can provoke premature senescence in breast stromal cells. In particular, breast stromal fibroblasts can become senescent after irradiation both in vitro and in vivo and they express an inflammatory phenotype and an altered profile of extracellular matrix components, thus facilitating tumor progression. Adipose-derived stem cells (ASCs) represent another major component of the breast tissue stroma. They are multipotent cells and due to their ability to differentiate in multiple cell lineages they play an important role in tissue maintenance and repair in normal and pathologic conditions. Here, we investigated the characteristics of human breast ASCs that became senescent prematurely after their exposure to ionizing radiation. We found decreased expression levels of the specific mesenchymal cell surface markers CD105, CD73, CD44, and CD90. In parallel, we demonstrated a significantly reduced expression of transcription factors regulating osteogenic (i.e., RUNX2), adipogenic (i.e., PPARγ), and chondrogenic (i.e., SOX9) differentiation; this was followed by an analogous reduction in their differentiation capacity. Furthermore, they overexpress inflammatory markers, that is, IL-6, IL-8, and ICAM-1, and a catabolic phenotype, marked by the reduction of collagen type I and the increase of MMP-1 and MMP-13 expression. Finally, we detected changes in proteoglycan expression, for example, the upregulation of syndecan 1 and syndecan 4 and the downregulation of decorin. Notably, all these alterations, when observed in the breast stroma, represent poor prognostic factors for tumor development. In conclusion, we showed that ionizing radiation-mediated prematurely senescent human breast ASCs have a decreased differentiation potential and express specific changes adding to the formation of a permissive environment for tumor growth.

Down-Regulation of the Proteoglycan Decorin Fills in the Tumor-Promoting Phenotype of Ionizing Radiation-Induced Senescent Human Breast Stromal Fibroblasts

Simple SummaryIonizing radiation (a typical remedy for breast cancer) results in the premature senescence of the adjacent to the neoplastic cells stromal fibroblasts. Here, we showed that these senescent fibroblasts are characterized by the down-regulation of the small leucine-rich proteoglycan decorin, a poor prognostic factor for the progression of the disease. Decorin down-regulation is mediated by secreted growth factors in an autocrine and paracrine (due to the interaction with breast cancer cells) manner, with bFGF and VEGF being the key players of this regulation in young and senescent breast stromal fibroblasts. Autophagy activation increases decorin mRNA levels, indicating that impaired autophagy is implicated in the reduction in decorin in this cell model. Decorin down-regulation acts additively to the already tumor-promoting phenotype of ionizing radiation-induced prematurely senescent human stromal fibroblasts, confirming that stromal senescence is a side-effect of radiotherapy that should be taken into account in the design of anticancer treatments.Down-regulation of the small leucine-rich proteoglycan decorin in the stroma is considered a poor prognostic factor for breast cancer progression. Ionizing radiation, an established treatment for breast cancer, provokes the premature senescence of the adjacent to the tumor stromal fibroblasts. Here, we showed that senescent human breast stromal fibroblasts are characterized by the down-regulation of decorin at the mRNA and protein level, as well as by its decreased deposition in the pericellular extracellular matrix in vitro. Senescence-associated decorin down-regulation is a long-lasting process rather than an immediate response to γ-irradiation. Growth factors were demonstrated to participate in an autocrine manner in decorin down-regulation, with bFGF and VEGF being the critical mediators of the phenomenon. Autophagy inhibition by chloroquine reduced decorin mRNA levels, while autophagy activation using the mTOR inhibitor rapamycin enhanced decorin transcription. Interestingly, the secretome from a series of both untreated and irradiated human breast cancer cell lines with different molecular profiles inhibited decorin expression in young and senescent stromal fibroblasts, which was annulled by SU5402, a bFGF and VEGF inhibitor. The novel phenotypic trait of senescent human breast stromal fibroblasts revealed here is added to their already described cancer-promoting role via the formation of a tumor-permissive environment.

Decorin Secreted by Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Induces Macrophage Polarization via CD44 to Repair Hyperoxic Lung Injury.

Bronchopulmonary dysplasia (BPD), caused by hyperoxia in newborns and infants, results in lung damage and abnormal pulmonary function. However, the current treatments for BPD are steroidal and pharmacological therapies, which cause neurodevelopmental impairment. Treatment with umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) is an efficient alternative approach. To prevent pulmonary inflammation in BPD, this study investigated the hypothesis that a key regulator was secreted by MSCs to polarize inflammatory macrophages into anti-inflammatory macrophages at inflammation sites. Lipopolysaccharide-induced macrophages co-cultured with MSCs secreted low levels of the inflammatory cytokines, IL-8 and IL-6, but high levels of the anti-inflammatory cytokine, IL-10. Silencing decorin in MSCs suppressed the expression of CD44, which mediates anti-inflammatory activity in macrophages. The effects of MSCs were examined in a rat model of hyperoxic lung damage. Macrophage polarization differed depending on the levels of decorin secreted by MSCs. Moreover, intratracheal injection of decorin-silenced MSCs or MSCs secreting low levels of decorin confirmed impaired alveolarization of damaged lung tissues by down-regulation of decorin. In tissues, a decrease in the anti-inflammatory macrophage marker, CD163, was observed via CD44. Thus, we identified decorin as a key paracrine factor, inducing macrophage polarization via CD44, a master immunoregulator in mesenchymal stem cells.

Expression and localization of the small proteoglycans decorin and biglycan in articular cartilage of Kashin-Beck disease and rats induced by T-2 toxin and selenium deficiency.

Kashin-Beck disease (KBD) is an endemic degenerative osteoarthropathy of uncertain etiology. Our study sought to identify a correlation between small proteoglycans decorin and biglycan expression and Kashin-Beck Disease. Immunohistochemistry was used to assess the decorin and biglycan levels in cartilage specimens from both child KBD patients, and rats fed with T-2 toxin under a selenium-deficient condition. Real-time PCR and Western blot were used to assess mRNA and protein levels of decorin and biglycan in rat cartilages, as well as in C28/I2 chondrocytes stimulated by T-2 toxin and selenium in vitro. The result showed that decorin was reduced in all zones of KBD articular cartilage, while the expression of biglycan was prominently increased in KBD cartilage samples. Increased expression of biglycan and reduced expression of decorin were observed at mRNA and protein levels in the cartilage of rats fed with T-2 toxin and selenium- deficiency plus T-2 toxin diet, when compared with the normal diet group. Moreover, In vitro stimulation of C28/I2 cells with T-2 toxin resulted in an upregulation of biglycan and downregulation of decorin, T-2 toxin induction of biglycan and decorin levels were partly rescued by selenium supplement. This study highlights the focal nature of the degenerative changes that occur in KBD cartilage and may suggest that the altered expression pattern of decorin and biglycan have an important role in the onset and pathogenesis of KBD.

Is assisted reproductive technology associated with findings of placenta in monochorionic-diamniotic twins?

Alteration of expression of various genes including extracellular matrix components, have been suggested to play major role in the placental pathologies after somatic cloning in mammals. The objectives of the present study were to analyze pattern of expression (mRNA and protein) of the small leucine-rich proteoglycan, Decorin in association with Type I Collagen and Fibronectin in bovine placental tissues from normal and clone pregnancies.Genotyping and allelic expression of Decorin were determined by Sanger sequencing. The expression patterns of Decorin, Type I collagen and Fibronectin 1 were analyzed by quantitative RT-qPCR and combined in situ hybydization (ISH) and immunohistochemistry (IHC) in endometrial and placental tissues from D18 to term from artificially inseminated and somatic cloning pregnancies.The expression levels of DCN increased in the AI endometrial stroma and chorionic mesenchyme during implantation and declined during placentome growth until term. Combined ISH and IHC revealed an unexpected discrepancy mRNA and protein tissue distribution. Moreover, Decorin was maintained in the placentome tissues from SCNT pregnancies while both mRNA and protein were absent in AI derived placenta.In bovine, the pattern of expression of Decorin exhibits significant changes during placental formation. Downregulation of Decorin is associated with proliferation, remodeling and vascularization of placental tissues. These observations reinforces the putative role of Decorin in these processes.These observations suggest that Decorin is involved in placental growth and that dysregulation of its expression is associated with placental abnormalities in SCNT derived pregnancy.

Spatial and temporal changes of Decorin, Type I collagen and Fibronectin expression in normal and clone bovine placenta

IntroductionAlteration of expression of various genes including extracellular matrix components, have been suggested to play major role in the placental pathologies after somatic cloning in mammals. The objectives of the present study were to analyze pattern of expression (mRNA and protein) of the small leucine-rich proteoglycan, Decorin in association with Type I Collagen and Fibronectin in bovine placental tissues from normal and clone pregnancies. MethodsGenotyping and allelic expression of Decorin were determined by Sanger sequencing. The expression patterns of Decorin, Type I collagen and Fibronectin 1 were analyzed by quantitative RT-qPCR and combined in situ hybydization (ISH) and immunohistochemistry (IHC) in endometrial and placental tissues from D18 to term from artificially inseminated and somatic cloning pregnancies. ResultsThe expression levels of DCN increased in the AI endometrial stroma and chorionic mesenchyme during implantation and declined during placentome growth until term. Combined ISH and IHC revealed an unexpected discrepancy mRNA and protein tissue distribution. Moreover, Decorin was maintained in the placentome tissues from SCNT pregnancies while both mRNA and protein were absent in AI derived placenta. DiscussionIn bovine, the pattern of expression of Decorin exhibits significant changes during placental formation. Downregulation of Decorin is associated with proliferation, remodeling and vascularization of placental tissues. These observations reinforces the putative role of Decorin in these processes. ConclusionsThese observations suggest that Decorin is involved in placental growth and that dysregulation of its expression is associated with placental abnormalities in SCNT derived pregnancy.

Human decorin regulates proliferation and migration of human lung cancer A549 cells

Background Decorin is a small leucine-rich proteoglycan and it plays an important role in regulation of cell growth and migration in various tumor cell lines. Decorin was found down-regulated in non-small cell lung cancer tissue and may be involved in regulation of lung cancer development. Methods In this study, lentivirus-mediated RNA interference and over expression were employed to change the expression levels of decorin in lung cancer A549 cells. We tested the cell cycle of A549 cells and the expression of transforming growth factor (TGF)-β1, cyclin D1, epidermal growth factor receptor (EGFR), P53, and P21. Results We found that up-regulation of decorin could inhibit proliferation, block cell cycle at G1 and decrease invasive activity of A549 cells. Moreover, we also show that up-regulation of decorin induced significant decreases of TGF-β1, cyclin D1 expression, phosphorylation of EGFR, and increases of P53 and P21 expression. Opposite results were observed in A549 cells with down-regulation of decorin. Conclusion Our results suggest that decorin is a key regulator involved in proliferation and migration of A549 cells.

Decorin-mediated inhibition of cholangiocarcinoma cell growth and migration and promotion of apoptosis are associated with E-cadherin in vitro

Emerging evidences have shown that decorin expression is significantly reduced in many cancer tissues and cancer cells. However, its biological role and clinical significance in cholangiocarcinoma development and progression are unknown. In this study, immunohistochemistry was conducted to investigate the expression of decorin in cholangiocarcinomas. The results showed that decorin levels markedly decreased in 44 cholangiocarcinoma tissues compared to 40 adjacent normal tissues. The analysis between decorin expression and clinicopathological characteristics in cholangiocarcinoma patients showed that patients with low levels of decorin expression had a relatively poor prognosis. Moreover, recombinant human decorin treatment and overexpression of decorin in cholangiocarcinoma cells could inhibit cell proliferation, migration, and invasion and promote apoptosis. Furthermore, the E-cadherin expression significantly increased after decorin overexpression or use of recombinant human decorin in cholangiocarcinoma cells. Our findings indicated that downregulation of decorin may be identified as a poor prognostic biomarker in cholangiocarcinomas. Also, decorin-mediated inhibition of cholangiocarcinoma cell growth, migration, and invasion and promotion of cell apoptosis might be through regulation of the expression of E-cadherin in vitro.

Extracellular matrix changes in melanoma promote tumor cell migration

In melanoma, invasion through the extracellular matrix (ECM) is a harbinger of dissemination and mortality. We find that changes in ECM composition of invasive human melanoma specimens resemble changes found during skin wound healing. Most highly upregulated in invasive melanoma was Tenascin C (TN‐C). Simultaneously, the matrix proteoglycans decorin and lumican were downregulated and the level of collagen I was decreased as the dermal matrix became ‘less mature’. The cellular origin of these matrix changes are not fully settled; still the melanoma cell lines, derived from tumors of different stages, express varied increased levels of TN‐C and fibronectin and decreased levels of collagen I compared to normal human melanocytes. Cells expressing higher amounts of TN‐C migrate faster in wound healing assays; on TN‐C pre‐coated surfaces both melanoma cells and normal melanocytes increase migration. Our group previously showed that the EGF‐like repeats of TN‐C are able to bind the EGFR with μM affinity and preferentially activate the motogenic signaling cascades. This upregulation of EGFR‐activating TN‐C is concomitant with downregulation of decorin and lumican, which have been reported to dampen EGFR signaling. Therefore, we hypothesize that the increased levels of TN‐C in melanomas promote tumor cell migration and invasion heralding dissemination through enhanced EGFR signaling.Funding: Internal (AW).

Downregulation of Decorin and Transforming Growth Factor-β1 by Decorin Gene Suppression in Tendinocytes

Scars formed after tendonitis result in altered tissue mechanical properties after injury. The interaction of collagen molecules with decorin affects collagen fibrogenesis, and scar tissue is fragile as a consequence of a large amount of decorin in the scar. We hypothesized that scar formation could be prevented by controlling decorin expression in tendinocytes. As a preliminary experiment, we treated tendinocytes with decorin antisense oligodeoxynucleotides (ODNs). Tendinocytes were isolated from Achilles tendons of New Zealand white rabbits and treated with ODN. When tendinocytes were transfected with decorin sense ODN, there was no alteration, whereas decorin antisense ODN-treated tendinocytes showed suppression of transforming growth factor (TGF)-β1 production. Decorin and TGF-β1-production of tendinocytes is regulated by decorin gene suppression. The results showed that the antisense approach is an attractive therapeutic strategy not only for preventing decorin deposition in scar tissue, which decreases collagen fibril diameter, but also for controlling TGF-β1 production, which leads to organ fibrosis.

Regional assessment of articular cartilage gene expression and small proteoglycan metabolism in an animal model of osteoarthritis

Osteoarthritis (OA), the commonest form of arthritis and a major cause of morbidity, is characterized by progressive degeneration of the articular cartilage. Along with increased production and activation of degradative enzymes, altered synthesis of cartilage matrix molecules and growth factors by resident chondrocytes is believed to play a central role in this pathological process. We used an ovine meniscectomy model of OA to evaluate changes in chondrocyte expression of types I, II and III collagen; aggrecan; the small leucine-rich proteoglycans (SLRPs) biglycan, decorin, lumican and fibromodulin; transforming growth factor-β; and connective tissue growth factor. Changes were evaluated separately in the medial and lateral tibial plateaux, and were confirmed for selected molecules using immunohistochemistry and Western blotting. Significant changes in mRNA levels were confined to the lateral compartment, where active cartilage degeneration was observed. In this region there was significant upregulation in expession of types I, II and III collagen, aggrecan, biglycan and lumican, concomitant with downregulation of decorin and connective tissue growth factor. The increases in type I and III collagen mRNA were accompanied by increased immunostaining for these proteins in cartilage. The upregulated lumican expression in degenerative cartilage was associated with increased lumican core protein deficient in keratan sulphate side-chains. Furthermore, there was evidence of significant fragmentation of SLRPs in both normal and arthritic tissue, with specific catabolites of biglycan and fibromodulin identified only in the cartilage from meniscectomized joints. This study highlights the focal nature of the degenerative changes that occur in OA cartilage and suggests that altered synthesis and proteolysis of SLRPs may play an important role in cartilage destruction in arthritis.

Expression of transcription factors and matrix genes in response to serum stimulus in vascular smooth muscle cells

During atherogenesis vascular smooth muscle cells are converted from a contractile into a synthetic phenotype characterized by enhanced matrix production. The transcription factors Gax and GATA-6 are considered negative, and Oct-1 positive regulators of the synthetic phenotype. Since the phenotype transition can be induced by culturing the cells with serum, we followed the expression of Gax, GATA-6 and Oct-1, integrins and matrix genes in quiescent porcine vascular smooth muscle cells after serum application. Comparisons were made between enzymatically released primary smooth muscle cells and cells grown out from explants of the medial layer of porcine aorta. The serum-mediated down-regulation of Gax was more intense than that of GATA-6, and stronger in explant-derived than in primary cells. Serum was without influence on the expression of Oct-1. Changes in the expression of the transcription factors preceded the induction of integrin alpha2 and the down-regulation of decorin, while mRNAs for laminin beta1 and osteopontin rose immediately after serum stimulation. Primary cells reacted more rapidly than explant cells with respect to changes in laminin isoforms. Studies with a Gax-expressing adenovirus indicated that among all the gene products tested only the expression of integrin alpha2 responded to Gax induction. Thus, our data show that i) Gax should be considered a transcription factor being directly responsible for only few aspects of the phenotypic conversion of smooth muscle cells and that ii) explant cells may represent a subpopulation of smooth muscle cells, which differ from the total population of smooth muscle cells, as obtained in primary culture, in their response to serum stimuli.

Altered Expression of Connective Tissue Genes in Postnatal Chondroinduced Human Dermal Fibroblasts

In a novel model for postnatal chondroinduction, normal human dermal fibroblasts (hDFs) cultured with demineralized bone powder (DBP) express chondrocyte features after 7 days. Representational difference analysis (RDA) prior to overt chondroblastogenesis (3 days) revealed altered expression of connective tissue genes (collagens, collagen receptors, and post-translational enzymes). Northern or RT-PCR analysis at 3, 7, 14, or 21 d showed different expression patterns for those genes. COL3A1 was transiently upregulated, whereas upregulation of COL11A1, integrin f -11, lysyl oxidase, and lysyl hydroxylase 2 mRNAs persisted for 7 days. Downregulation of decorin was sustained for 21 d. The expression of the post-translational enzymes induced by DBP was unique when compared with human skin and human articular chondrocytes. Thus, the data suggest an "induced chondroblast" stage with a unique connective tissue gene expression profile that may result in a matrix supportive of chondrogenesis by postnatal cells.

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

Purpose: Transforming growth factor beta (TGF-β) 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-β 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. J Pediatr Surg 36:1666-1671. Copyright © 2001 by W.B. Saunders Company.

Different galactosaminoglycan composition of small proteoglycans from osteosarcoma cells.

The expression of the core proteins and the co-polymeric structure of the glycosaminoglycan chains of three different small proteoglycans (biglycan, decorin, proteoglycan-100) have been examined in the human osteosarcoma cell line MG-63. The three proteoglycans, which are carrying either one or two chondroitin/dermatan sulphate chains, were synthesized in a similar molar ratio, as determined by [35S]methionine as well as by [35S]sulphate incorporation. After sulphate ester formation, they were secreted into the culture medium with similar kinetics. Immune staining with monospecific antibodies revealed that at least biglycan and proteoglycan-100 were present in all individual cells. However, in contrast to these similarities, the glycosaminoglycan moiety of proteoglycan-100 was composed exclusively of chondroitin 4- and 6-sulphate repeating units, whereas biglycan and decorin contained hybrid polymers of chondroitin and dermatan sulphate with approximately 90% 4-sulphated disaccharide repeating units. Treatment with transforming growth factor-beta resulted in a marked down-regulation of proteoglycan-100 synthesis without significant alteration of its glycosaminoglycan structure. Up-regulation of biglycan and moderate down-regulation of decorin were accompanied by a small decrease in the conversion of chondroitin to dermatan sulphate disaccharide units in both cases. The specific stimulation of the biosynthesis of proteoglycan-100 by tumour necrosis factor-alpha was without consequence for its glycosaminoglycan composition. Treatment with tumour necrosis factor-alpha had no influence on the synthesis and glycosaminoglycan structure of biglycan and decorin. These findings support the proposal of the importance of the core protein for the determination of the extent of glycosaminoglycan modification.