Gene Expression Of Extracellular Matrix Proteins Research Articles

Crenigacestat blocking notch pathway reduces liver fibrosis in the surrounding ecosystem of intrahepatic CCA viaTGF-β inhibition

BackgroundIntrahepatic cholangiocarcinoma (iCCA) is a highly malignant tumor characterized by an intensive desmoplastic reaction due to the exaggerated presence of the extracellular (ECM) matrix components. Liver fibroblasts close to the tumor, activated by transforming growth factor (TGF)-β1 and expressing high levels of α-smooth muscle actin (α-SMA), become cancer-associated fibroblasts (CAFs). CAFs are deputed to produce and secrete ECM components and crosstalk with cancer cells favoring tumor progression and resistance to therapy. Overexpression of Notch signaling is implicated in CCA development and growth. The study aimed to determine the effectiveness of the Notch inhibitor, Crenigacestat, on the surrounding microenvironment of iCCA.MethodsWe investigated Crenigacestat’s effectiveness in a PDX model of iCCA and human primary culture of CAFs isolated from patients with iCCA.ResultsIn silico analysis of transcriptomic profiling from PDX iCCA tissues treated with Crenigacestat highlighted “liver fibrosis” as one of the most modulated pathways. In the iCCA PDX model, Crenigacestat treatment significantly (p < 0.001) reduced peritumoral liver fibrosis. Similar results were obtained in a hydrodynamic model of iCCA. Bioinformatic prediction of the upstream regulators related to liver fibrosis in the iCCA PDX treated with Crenigacestat revealed the involvement of the TGF-β1 pathway as a master regulator gene showing a robust connection between TGF-β1 and Notch pathways. Consistently, drug treatment significantly (p < 0.05) reduced TGF-β1 mRNA and protein levels in tumoral tissue. In PDX tissues, Crenigacestat remarkably inhibited TGF-β signaling and extracellular matrix protein gene expression and reduced α-SMA expression. Furthermore, Crenigacestat synergistically increased Gemcitabine effectiveness in the iCCA PDX model. In 31 iCCA patients, TGF-β1 and α-SMA were upregulated in the tumoral compared with peritumoral tissues. In freshly isolated CAFs from patients with iCCA, Crenigacestat significantly (p < 0.001) inhibited Notch signaling, TGF-β1 secretion, and Smad-2 activation. Consequently, Crenigacestat also inactivated CAFs reducing (p < 0.001) α-SMA expression. Finally, CAFs treated with Crenigacestat produced less (p < 005) ECM components such as fibronectin, collagen 1A1, and collagen 1A2.ConclusionsNotch signaling inhibition reduces the peritumoral desmoplastic reaction in iCCA, blocking the TGF-β1 canonical pathway.

Asthmatic Eosinophils Alter the Gene Expression of Extracellular Matrix Proteins in Airway Smooth Muscle Cells and Pulmonary Fibroblasts.

The impaired production of extracellular matrix (ECM) proteins by airway smooth muscle cells (ASMC) and pulmonary fibroblasts (PF) is a part of airway remodeling in asthma. This process might be influenced by eosinophils that migrate to the airway and abundantly secrete various cytokines, including TGF-β. We aimed to investigate the effect of asthmatic eosinophils on the gene expression of ECM proteins in ASMC and PF. A total of 34 study subjects were recruited: 14 with allergic asthma (AA), 9 with severe non-allergic eosinophilic asthma (SNEA), and 11 healthy subjects (HS). All AA patients underwent bronchial allergen challenge with D. pteronyssinus. The peripheral blood eosinophils were isolated using high-density centrifugation and magnetic separation. The individual cell cultures were made using hTERT ASMC and MRC-5 cell lines and the subjects’ eosinophils. The gene expression of ECM and the TGF-β signaling pathway was analyzed using qRT-PCR. We found that asthmatic eosinophils significantly promoted collagen I, fibronectin, versican, tenascin C, decorin, vitronectin, periostin, vimentin, MMP-9, ADAM33, TIMP-1, and TIMP-2 gene expression in ASMC and collagen I, collagen III, fibronectin, elastin, decorin, MMP-2, and TIMP-2 gene expression in PF compared with the HS eosinophil effect. The asthmatic eosinophils significantly increased the gene expression of several canonical and non-canonical TGF-β signaling pathway components in ASMC and PF compared with the HS eosinophil effect. The allergen-activated AA and SNEA eosinophils had a greater effect on these changes. In conclusion, asthmatic eosinophils, especially SNEA and allergen-activated eosinophils, imbalanced the gene expression of ECM proteins and their degradation-regulating proteins. These changes were associated with increased gene expression of TGF-β signaling pathway molecules in ASMC and PF.

Fructose Metabolism and Regulation of Extracellular Matrix Protein Gene Expression in Activated Macrophages

Abstract Objectives Recently fructose has been linked to the development of Nonalcoholic Fatty Liver Disease (NAFLD), but the mechanisms behind the progression remain to be elucidated. Kupffer cells have been identified as regulators of hepatic inflammation and extracellular matrix (ECM) proteins. Activated macrophages are known to express tissue inhibitor of metalloproteinase (TIMP1), which inhibits matrix metalloproteinase 9 (MMP9) activity of reconstructing ECM which leads to fibrosis. In humans and mouse models, TIMP1 expression is positively correlated with the progression of NAFLD. Based on these findings, we hypothesize that fructose regulates TIMP1 gene expression in activated proinflammatory macrophages. Methods Using an in vitro model of J774 macrophages and primary Kupffer cells, cells were treated to induce an M1 phenotype in the presence of glucose or fructose. Cells were harvested for RNA and RT-PCR was conducted to measure ECM gene expression. Isolated Kupffer cells were collected from C57BL/6J mice fed a high fat diet (HFD) supplemented with 30% fructose or 30% glucose and analyzed for ECM expression. To examine fructose uptake and intra- and extracellular metabolites, mass spectrophotometry and nuclear magnetic resonance was conducted. Results Timp1 gene expression was significantly increased in J77.4 cells treated with fructose compared to glucose. Surprisingly, fructose treatment decreased Mmp9 gene expression. Likewise, fructose treatment increased TIMP1 protein expression in isolated Kupffer cells. In vivo, isolated hepatic macrophages from mice fed HF and high fructose diet had elevated Timp1 gene expression compared to mice fed high glucose diet. Extracellular levels of lactate decreased by 1.5-fold in fructose treated J77.4 cells compared to glucose. Metabolites involved in the TCA cycle and mitochondrial function were decreased when treated with fructose compared to glucose in non-activated macrophages. However, fructose treatment increased intracellular methanol and acetate levels in M1 macrophages compared to glucose. Conclusions Our data suggest that fructose upregulates Timp1 expression and possibly decreases mitochondrial function while increasing acetate and methanol production, identifying new mechanisms by which fructose drives the progression of NAFLD. Funding Sources Kenan Institute North Carolina University.

Noni Juice and Hydrolyzed Fish Collagen Supplement Improves Skin Elasticity

Morinda citrifolia, more commonly known as noni, is a tropical tree with fruit that has a wide variety of traditional uses and biological effects. It had been used for the maintenance of skin health by Pacific Islanders and has been found to promote collagen deposition in vivo. Oral ingestion of hydrolyzed collagen has also been shown to improve skin quality. A 21-day human intervention study was conducted to evaluate a dietary supplement containing a combination of noni fruit juice and hydrolyzed marine collagen, as well as other ingredients, on skin viscoelastic properties in healthy Japanese adults. Daily ingestion of the supplement significantly improved net elasticity and biological elasticity measurements of the cheek. This also accompanied a trend for lowered skin autofluorescence, a measurement of skin glycation. The results indicate that the combination of noni fruit juice and hydrolyzed collagen improved skin biomechanical properties through enhanced collagen and elastin deposition in the skin, reduced skin glycation and improved skin hydration, possibly from increased hyaluronic acid concentration. Noni fruit juice also effectively scavenged cumene hydroperoxide in vitro. The positive effects on skin quality are likely due, in part, to the antioxidant and antiglycative properties of the supplement, as well as its ability to induce fibroblast proliferation and influence extracellular matrix protein gene expression.

PLLA scaffolds produced by thermally induced phase separation (TIPS) allow human chondrocyte growth and extracellular matrix formation dependent on pore size

Damage of hyaline cartilage species such as nasoseptal or joint cartilage requires proper reconstruction, which remains challenging due to the low intrinsic repair capacity of this tissue. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair.The aim of this work was to assess the viability, attachment, morphology, extracellular matrix (ECM) production of human articular and nasoseptal chondrocytes cultured in vitro in porous poly(l-lactic) (PLLA) scaffolds of two selected pore sizes (100 and 200μm).The PLLA scaffolds with 100 and 200μm pore sizes were prepared via ternary thermally induced phase separation (TIPS) technique and analyzed using scanning electron microscopy (SEM). Articular and nasoseptal chondrocytes were seeded on the scaffold and cultures maintained for 7 and 14days. Live/dead staining, (immuno-)histology and gene expression analysis of type II, type I collagen, aggrecan and SOX9 were performed to assess scaffold cytocompatibility and chondrocyte phenotype.The majority of both chondrocyte types survived on both scaffolds for the whole culture period. Hematoxylin-eosin (HE), alcian blue (visualizing glycosaminoglycans) stainings, immunoreactivity and gene expression of ECM proteins and cartilage marker (type II, I collagen, aggrecan, SOX9) of the chondrocyte scaffold constructs indicated that the smaller pore dimensions promoted the differentiation of the chondrocytes compared with the larger pore size.The present work revealed that the scaffold pore size is an important factor influencing chondrocyte differentiation and indicated that the scaffolds with 100μm pores serve as a cytocompatible basis for further future modifications.

23‐Hydroxytormentic acid protects human dermal fibroblasts by attenuating UVA‐induced oxidative stress

Ultraviolet A (UVA), one of the major components of sunlight, can penetrate the dermal layer of the skin and generate reactive oxygen species (ROS). It causes alterations in the dermal connective tissue and gene expression, inflammation, photoaging, and DNA damage. Therefore, the harmful effects of UVA and strategies to reduce it have been consistently investigated. 23-Hydroxytormentic acid (23-HTA) has been demonstrated to improve drug-induced nephrotoxicity and exhibit several free radical scavenging effects with other molecules. Therefore, the aim of this study was to investigate the anti-inflammatory effects and extracellular matrix (ECM) reconstructive activity of 23-HTA in UVA-irradiated normal human dermal fibroblasts (NHDFs). The antioxidant capacity of 23-HTA was determined by examining its scavenging activities against hydrogen peroxide, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid), and diphenylpicrylhydrazyl in vitro. Its effect on cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tertazolium bromide, and 2,7-dichlorofluorescin diacetate was used to investigate intracellular ROS scavenging activity. The mRNA levels of antioxidant enzymes and pro-inflammatory cytokines were detected using quantitative real-time polymerase chain reaction. A senescence-associated β-galactosidase (SA-β-gal) staining kit was used to assess senescent cells. 23-HTA showed antioxidant capacity mediated by ROS scavenging and regulation of antioxidant-related gene expression. Further, the SA-β-gal analysis and mRNA expression of matrix metalloproteinases and type I procollagen suggested that 23-HTA regulates the gene expression of ECM proteins and cellular senescence under UVA-irradiated conditions. In conclusion, 23-HTA protects against and attenuates UVA-induced oxidative stress in NHDFs likely via the nuclear factor erythroid-derived 2-like 2 signaling pathway.

Suppression of Eosinophil Integrins Prevents Remodeling of Airway Smooth Muscle in Asthma.

Background: Airway smooth muscle (ASM) remodeling is an important component of the structural changes to airways seen in asthma. Eosinophils are the prominent inflammatory cells in asthma, and there is some evidence that they contribute to ASM remodeling via released mediators and direct contact through integrin–ligand interactions. Eosinophils express several types of outer membrane integrin, which are responsible for cell–cell and cell–extracellular matrix interactions. In our previous study we demonstrated that asthmatic eosinophils show increased adhesion to ASM cells and it may be important factor contributing to ASM remodeling in asthma. According to these findings, in the present study we investigated the effects of suppression of eosinophil integrin on eosinophil-induced ASM remodeling in asthma.Materials and Methods: Individual combined cell cultures of immortalized human ASM cells and eosinophils from peripheral blood of 22 asthmatic patients and 17 healthy controls were prepared. Eosinophil adhesion was evaluated using eosinophil peroxidase activity assay. Genes expression levels in ASM cells and eosinophils were measured using quantitative real-time PCR. ASM cell proliferation was measured using alamarBlue® solution. Eosinophil integrins were blocked by incubating with Arg-Gly-Asp-Ser peptide.Results: Eosinophils from the asthma group showed increased outer membrane α4β1 and αMβ2 integrin expression, increased adhesion to ASM cells, and overexpression of TGF-β1 compared with eosinophils from the healthy control group. Blockade of eosinophil RGD-binding integrins by Arg-Gly-Asp-Ser peptide significantly reduced adhesion of eosinophils to ASM cells in both groups. Integrin-blocking decreased the effects of eosinophils on TGF-β1, WNT-5a, and extracellular matrix protein gene expression in ASM cells and ASM cell proliferation in both groups. These effects were more pronounced in the asthma group compared with the control group.Conclusion: Suppression of eosinophil-ASM interaction via RGD-binding integrins attenuates eosinophil-induced ASM remodeling in asthma.Trial Registration: ClinicalTrials.gov Identifier: NCT02648074.

Physical and biological effects of gellan gum on decreasing postoperative adhesion in a rat model

An antiadhesion membrane made from gellan gum was fabricated and characterized. A 12-µm-thick membrane of gellan gum was prepared and reacted with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide to obtain a cross-linked membrane (G/A70) with 87% gel content and a tensile strength of 46.5 MPa. In vivo, the G/A70 membrane had 90% less tissue adhesion. Inflammation-related and extracellular matrix protein gene expression in a rat model of abdominal surgery was found by real-time quantitative reverse transcription polymerase chain reaction analysis. On day 3, after surgery, the gene expression of ceruloplasmin and type V collagen in the G/A70-treated group was 1.9 and 0.3 times that of the control group, respectively. The G/A70 membrane elicited mild inflammation but suppressed type V collagen synthesis and reduced the occurrence of tissue adhesion. These findings provide insights into the properties of gellan gum antiadhesion membranes and help to overcome problems involving tissue adhesions in surgical procedures.

Abstract 4244: The role of hypoxia on the tumor-stromal interaction in pancreatic ductal adenocarcinoma

Abstract INTRODUCTION: Pancreatic cancer is characterized by extraordinary fibrosis and pancreatic stellate cells (PSCs) are the major player in synthesizing extracellular matrix (ECM) upon activation. The interaction/communication between PSCs and pancreatic ductal adenocarcinoma (PDAC) cells is essential for inducing stroma/ECM production, pancreatic cancer progression and general therapy resistance. Compared to traditional 2D cell culture, cells in a three-dimensional context demonstrate different behavior and functions as reflected by building up a microenvironment that more closely mimics the one observed in the native tissue. This feature is especially critical for testing drug efficiency as cellular response to drugs is profoundly affected by environmental cues. AIMS &amp; METHODS: Our aim was to build up a more reliable and predictive drug screening system. To this end we set up and compared 2D and 3D cell cultures containing either human PSC and PDAC cells alone or in combination. RESULTS: Among PDAC cells, panc-1 cells are the most commonly used which are also able to form spheres in vitro. We generated mono-spheres from panc-1 cells and compared them to conventional 2D culture. The efficiency of different drugs on viability of cells in panc-1 sphere resulted to be much lower than on viability in 2D cultures. Cells in 3D compared to the 2D culture show higher gene expression for ECM proteins as collagen and fibronectin, for growth factors as PDGF and VEGF, as well as for protein like Cox2, Glut1. We co-cultured panc-1 and PSCs, allowing them to interact and form hetero-spheres in which PSCs localized in the cortical area and were identified e.g. by expression of asma, a marker for PSCs activation. These avascular mini-tumors were further characterized at different levels. CONCLUSION: 3D cultures are more resistant to chemotherapy compared to their 2D counterpart offering a more predictive platform for drug screening before proceeding to more expensive in vivo models and clinical trials. The avascular mini-tumors can be considered as an alternative in vitro cell model for studying pancreatic cancer development and fibrosis from a more complete perspective. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4244. doi:1538-7445.AM2012-4244

Stem Cell-Derived Extracellular Matrix Enables Survival and Multilineage Differentiation within Superporous Hydrogels

Hydrophilic poly(ethylene glycol) diacrylate (PEGDA) hydrogel surfaces resist protein adsorption and are generally thought to be unsuitable for anchorage-dependent cells to adhere. Intriguingly, our previous findings revealed that PEGDA superporous hydrogel scaffolds (SPHs) allow anchorage of bone marrow derived human mesenchymal stem cells (hMSCs) and support their long-term survival. Therefore, we hypothesized that the physicochemical characteristics of the scaffold impart properties that could foster cellular responses. We examined if hMSCs alter their microenvironment to allow cell attachment by synthesizing their own extracellular matrix (ECM) proteins. Immunofluorescence staining revealed extensive expression of collagen type I, collagen type IV, laminin, and fibronectin within hMSC-seeded SPHs by the end of the third week. Whether cultured in serum-free or serum-supplemented medium, hMSC ECM protein gene expression patterns exhibited no substantial changes. The presence of serum proteins is required for initial anchorage of hMSCs within the SPHs but not for the hMSC survival after 24 h. In contrast to 2D expansion on tissue culture plastic (TCP), hMSCs cultured within SPHs proliferate similarly in the presence or absence of serum. To test whether hMSCs retain their undifferentiated state within the SPHs, cell-seeded constructs were cultured for 3 weeks in stem cell maintenance medium and the expression of hMSC-specific cell surface markers were evaluated by flow cytometry. CD105, CD90, CD73, and CD44 were present to a similar extent in the SPH and in 2D monolayer culture. We further demonstrated multilineage potential of hMSCs grown in the PEGDA SPHs, whereby differentiation into osteoblasts, chondrocytes, and adipocytes could be induced. The present study demonstrates the potential of hMSCs to alter the "blank" PEGDA environment to a milieu conducive to cell growth and multilineage differentiation by secreting adhesive ECM proteins within the porous network of the SPH scaffolds.

Fibrosis: is it a coactivator disease?

Fibrosis is an abnormal fibroblast-activation-associated pathological manifestation in injured organs where excessive non-physiological synthesis and accumulation of extracellular matrix (ECM) proteins by activated/differentiated fibroblasts disrupts tissue homeostasis. Like other eukaryotic genes, expression of ECM protein genes not only depends on its gene sequences in the regulatory region but also influenced by non-genetic factors called epigenetic regulators including acetyltransferases, deacetylases, methyltransferases and microRNAs. The acetyltransferase p300 (ATp300), a transcriptional coactivator, is a major player in the epigenetic regulation of genes whose products are involved in cellular growth, proliferation, apoptosis and essential for embryonic development. ATp300 acetylates specific lysine residues in histones and transcription factors (KAT) and as a transcriptional coactivator it forms a bridge between upstream regulatory element binding protein complex and basal transcriptional machinery. Abnormal coactivator activity-associated diseases are known as coactivator diseases. Abnormalities in ATp300 activities in adults are associated with numerous diseases. Here, we review the significant roles of ATp300 in epigenetic regulation of collagen synthesis and deposition in extracellular spaces, matrix remodeling and tissue fibrogenesis. The present day understanding on the distinct role of acetyltransferases, deacetylases, and deacetylase inhibitors on epigenetic regulation of matrix remodeling and fibrosis has also been discussed.

Fibrosis is it a coactivator disease

Fibrosis is an abnormal fibroblast-activation-associated pathological manifestation in injured organs where excessive non-physiological synthesis and accumulation of extracellular matrix (ECM) proteins by activated/differentiated fibroblasts disrupts tissue homeostasis. Like other eukaryotic genes, expression of ECM protein genes not only depends on its gene sequences in the regulatory region but also influenced by non-genetic factors called epigenetic regulators including acetyltransferases, deacetylases, methyltransferases and microRNAs. The acetyltransferase p300 (ATp300), a transcriptional coactivator, is a major player in the epigenetic regulation of genes whose products are involved in cellular growth, proliferation, apoptosis and essential for embryonic development. ATp300 acetylates specific lysine residues in histones and transcription factors (KAT) and as a transcriptional coactivator it forms a bridge between upstream regulatory element binding protein complex and basal transcriptional machinery. Abnormal coactivator activity-associated diseases are known as coactivator diseases. Abnormalities in ATp300 activities in adults are associated with numerous diseases. Here, we review the significant roles of ATp300 in epigenetic regulation of collagen synthesis and deposition in extracellular spaces, matrix remodeling and tissue fibrogenesis. The present day understanding on the distinct role of acetyltransferases, deacetylases, and deacetylase inhibitors on epigenetic regulation of matrix remodeling and fibrosis has also been discussed.

The effect of duration on the simultaneous color contrast

Damage of hyaline cartilage species such as nasoseptal or joint cartilage requires proper reconstruction, which remains challenging due to the low intrinsic repair capacity of this tissue. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair.The aim of this work was to assess the viability, attachment, morphology, extracellular matrix (ECM) production of human articular and nasoseptal chondrocytes cultured in vitro in porous poly(l-lactic) (PLLA) scaffolds of two selected pore sizes (100 and 200 μm).The PLLA scaffolds with 100 and 200 μm pore sizes were prepared via ternary thermally induced phase separation (TIPS) technique and analyzed using scanning electron microscopy (SEM). Articular and nasoseptal chondrocytes were seeded on the scaffold and cultures maintained for 7 and 14 days. Live/dead staining, (immuno-)histology and gene expression analysis of type II, type I collagen, aggrecan and SOX9 were performed to assess scaffold cytocompatibility and chondrocyte phenotype.The majority of both chondrocyte types survived on both scaffolds for the whole culture period. Hematoxylin-eosin (HE), alcian blue (visualizing glycosaminoglycans) stainings, immunoreactivity and gene expression of ECM proteins and cartilage marker (type II, I collagen, aggrecan, SOX9) of the chondrocyte scaffold constructs indicated that the smaller pore dimensions promoted the differentiation of the chondrocytes compared with the larger pore size.The present work revealed that the scaffold pore size is an important factor influencing chondrocyte differentiation and indicated that the scaffolds with 100 μm pores serve as a cytocompatible basis for further future modifications.

Effects of a Repeated Bout of Eccentric Exercise on Skeletal Muscle Function and Gene Expression

Eccentric exercise (ECC) results in muscle damage indicated by reduced muscle function (soreness and strength loss). There is an adaptation to the damage such that the response to a second bout of ECC is reduced compared with the first bout. The underlying mechanisms that assist in the skeletal muscle remodeling process are largely unknown. The extracellular matrix (EM) protein tenascin-C (TNC) has been related to cardiac muscle remodeling in animals and muscle soreness in humans. PURPOSE: To examine whether gene expression of EM proteins are altered by a repeated bout of exercise. METHODS: 12 healthy subjects were randomized into the study, 8 (4 men/4 women) completed the two bouts of eccentric exercise (ECC) consisting of 15 descents of 10 flights of stairs and 4 (2 men/2 women) performed no exercise (CON). The 2 exercise bouts (ECC1 and ECC2) were separated by 2 wks. Skeletal muscle biopsies (MB) were taken from the vastus lateralis. The first biopsy (MB1, baseline) was taken 1wk before ECC1, the second (MB2) at 24 h post-ECC1, and the third (MB3) at 24 h post-ECC2. The CON subjects had three MB at the same time points. Samples were processed for qRT-PCR analysis for the following genes INTGB1, INTGA7, TNC, COL3, COL4, MMP9, MMP2, TIMP2, LAMA2. Samples were normalized to a housekeeping gene (B2M) and to then to their respective baseline sample (MB1). RESULTS: There was less soreness after ECC2 compared to ECC1. The major finding was that TNC was profoundly elevated after ECC1 (60.3 fold-change ±19.9; p<.05) and ECC2 (26.9 fold±12.5; p<.05). Control group values were 1.4 and 2.22 fold-change, respectively. INTGB3 was elevated after ECC1 and ECC2 (1.46±0.23 and 1.75±0.20 fold-change, p<.05), and there was a decrease from ECC1 to ECC2 (p<.05). Control group values were 0.59±0.19 and 0.96±0.14, respectively. No other genes changed significantly. CONCLUSION: Eccentric exercise profoundly elevated TNC, but there was no significant repeated about effect. There was a significant increase in INTGB1, a protein that connects the extracellular matrix and acts as a mechanotransducer for muscle. Overall, the extracellular matrix genes (except INTGB1) do not appear to be related to the repeated bout effect, but the increase in INTGB1 gene expression suggests some role for the ECM in the adaptation process that occurs with a repeated bout.

Rhinovirus infection induces expression of airway remodelling factors in vitro and in vivo

A hallmark of asthma is airway remodelling, which includes increased deposition of extracellular matrix (ECM) protein. Viral infections may promote the development of asthma and are the most common causes of asthma exacerbations. We evaluated whether rhinovirus (RV) infection induces airway remodelling, as assessed by ECM deposition. Primary human bronchial epithelial cells and lung parenchymal fibroblasts were infected with RV-2 or RV-16, or treated with RV-16 RNA, imiquimod (Toll-like receptor (TLR) 7/8 agonist) or polyinosinic : polycytidylic acid (poly I : C) (activator of TLR 3, retinoic-acid-inducible protein I and melanoma-differentiated-associated gene 5). Changes in ECM proteins and their transcription were measured by ELISA and quantitative real-time PCR. In addition, gene expression for ECM proteins was assessed in a mouse model of RV infection. RV infection increased deposition of the ECM protein, perlecan, by human bronchial epithelial cells, and collagen V and matrix-bound vascular endothelial growth factor were increased in both human bronchial epithelial cell and fibroblast cultures. Purified RV-16 RNA, poly I : C and imiquimod induced similar increases in ECM deposition to those observed with RV-infected fibroblasts. However, only poly I : C induced ECM deposition by bronchial epithelial cells, suggesting that RV-induced ECM deposition is mediated through TLR. Furthermore, gene expression for fibronectin and collagen I was increased in lung homogenates of mice infected with RV-1b. RV infection and TLR ligands promote ECM deposition in isolated cell systems and RV induces ECM gene expression in vivo, thus demonstrating that RV has the potential to contribute to remodelling of the airways through induction of ECM deposition.

Cardiac Inflammation Contributes to Changes in the Extracellular Matrix in Patients With Heart Failure and Normal Ejection Fraction

The pathophysiology of heart failure with normal ejection fraction (HFNEF) is still under discussion. Here we report the influence of cardiac inflammation on extracellular matrix (ECM) remodeling in patients with HFNEF. We investigated left ventricular systolic and diastolic function in 20 patients with HFNEF and 8 control patients by conductance catheter methods and echocardiography. Endomyocardial biopsy samples were also obtained, and ECM proteins as well as cardiac inflammatory cells were investigated. Primary human cardiac fibroblasts were outgrown from the endomyocardial biopsy samples to investigate the gene expression of ECM proteins after stimulation with transforming growth factor-β. Diastolic dysfunction was present in the HFNEF patients compared with the control patients. In endomyocardial biopsy samples from HFNEF patients, we found an accumulation of cardiac collagen, which was accompanied by a decrease in the major collagenase system (matrix metalloproteinase-1) in the heart. Moreover, a subset of inflammatory cells, which expressed the profibrotic growth factor transforming growth factor-β, could be documented in the HFNEF patients. Stimulation of primary human cardiac fibroblasts from HFNEF patients with transforming growth factor-β resulted in transdifferentiation of fibroblasts to myofibroblasts, which produced more collagen and decreased the amount of matrix metalloproteinase-1, the major collagenase in the human heart. A positive correlation between cardiac collagen, as well as the amount of inflammatory cells, and diastolic dysfunction was evident and suggests a direct influence of inflammation on fibrosis triggering diastolic dysfunction. Cardiac inflammation contributes to diastolic dysfunction in HFNEF by triggering the accumulation of ECM.

Extracellular matrix expression of human tenocytes in three‐dimensional air–liquid and PLGA cultures compared with tendon tissue: Implications for tendon tissue engineering

Tenocyte transplantation may prove to be an approach to support healing of tendon defects. Cell-cell and cell-matrix contacts within three-dimensional (3D) cultures may prevent tenocyte dedifferentiation observed in monolayer (2D) culture. The present study compares both neotissue formation and tenocyte extracellular matrix (ECM) expression in 2D and 3D cultures directly with that of native tendon, in order to determine optimal conditions for tendon tissue engineering. Primary human tenocytes were embedded in poly[lactic-co-glycolic-acid] (PLGA)-scaffolds and high-density cultures. Neotissue formation was examined by hematoxyline-eosine (H&E) and immunofluorescence staining. Gene expression of ECM proteins and vascular endothelial growth factor (VEGF) was compared at days 0 (2D), 14, and 28 in 3D cultures and tendon. Histomorphology of 3D culture showed tendon-like tissue as tenocyte cell nuclei became more elongated and ECM accumulated. Type I collagen gene expression was higher in 2D culture than in tendon and decreased in 4-week-old 3D cultures, whereas type III collagen was only elevated in high-density culture compared with tendon. Decorin and COMP were reduced in 2D and increased in 3D culture almost to ex vivo level. These results suggest that the 3D high-density or biodegradable scaffolds cultures encourage the differentiation of expanded monolayer tenocytes in vitro to tendon-like tissue.

Catalase overexpression attenuates angiotensinogen expression and apoptosis in diabetic mice

Increased generation of reactive oxygen species (ROS) leads to oxidative stress in diabetes. Catalase is a highly conserved heme-containing protein that reduces hydrogen peroxide to water and oxygen and is an important factor decreasing cellular injury owing to oxidative stress. Hyperglycemic conditions increase oxidative stress and angiotensinogen gene expression. Angiotensinogen conversion to angiotensin II leads to a furtherance in oxidative stress through increased generation of reactive oxygen species. In this study, we utilized mice transgenically overexpressing rat catalase in a kidney-specific manner to determine the impact on ROS, angiotensinogen and apoptotic gene expression in proximal tubule cells of diabetic animals. Proximal tubules isolated from wild-type and transgenic animals without or with streptozotocin-induced diabetes were incubated in low glucose media in the absence or presence of angiotensin II or in a high-glucose media. Our results show that the overexpression of catalase prevents the stimulation of ROS and angiotensinogen mRNA in tubules owing to elevated glucose or angiotensin II in vitro. Additionally, overexpression of catalase attenuated ROS generation, angiotensinogen and proapoptotic gene expression and apoptosis in the kidneys of diabetic mice in vivo. Our studies point to an important role of ROS in the pathophysiology of diabetic nephropathy.

Effects of streptozotocin-induced diabetes and physical training on gene expression of extracellular matrix proteins in mouse skeletal muscle

Diabetes induces changes in the structure and function of the extracellular matrix (ECM) in many tissues. We investigated the effects of diabetes, physical training, and their combination on the gene expression of ECM proteins in skeletal muscle. Mice were divided to control (C), training (T), streptozotocin-induced diabetic (D), and diabetic training (DT) groups. Training groups (T, DT) performed 1, 3, or 5 wk of endurance training on a treadmill. Gene expression of calf muscles was analyzed using microarray and quantitative PCR. Training group samples were collected 24 h after the last training session. Diabetes affected the gene expression of several collagens (types I, III, IV, V, VI, and XV), some noncollagenous glycoproteins, and proteoglycans (e.g., elastin, thrombospondin-1, laminin-2, decorin). Reduced gene expression of collagens in diabetic skeletal muscle was partially attenuated as a result of physical training. In diabetes, mRNA expression of the basement membrane (BM) collagens decreased and that of noncollagenous glycoproteins increased. This may change the structure of the BM in a less collagenous direction and affect its properties.

Human Bone Derived Cell (HBDC) Behaviour of Sol-Gel Derived Carbonate Hydroxyapatite Coatings on Titanium Alloy Substrates

Poor cell adhesion to orthopaedic and dental implants results in implant failure. Establishing and maintaining mature bone at the bone/device interface is critical to the long-term success of the prostheses. Considerable effort has been devoted to alter the surface characteristics of these biomaterials in order to improve the initial interlocking of device and skeleton in the noncemented joint prosthesis. Previously we demonstrated that surface chemistry modification of bioceramics induced osteogenesis. In the present work, we investigate the effect of surface chemistry modification of titanium alloy (Ti-6Al-4V) with alkoxide-derived carbonate hydroxyapatite (CHAp) using sol-gel coating methods on human bone derived cell (HBDC)behaviour. Western blotting demonstrated that sol gel coating of Ti-6Al-4V with CHAp upregulated the expression of key signalling protein Shc isoforms (p46, p52, p66) and phosphorylated Erk1/2. CHAp-modification of Ti-6Al-4V is associated with signal transduction pathways involving the key signalling protein Shc and ERK1/2 which may lead to enhanced gene expression of extracellular matrix proteins at the skeletal tissue/device interface.