Fibronectin Gene Expression Research Articles

Macrophage behavior and interplay with gingival fibroblasts cultured on six commercially available titanium, zirconium, and titanium-zirconium dental implants.

The host-material interface has been a crucial relationship dictating the successful integration of biomaterials, including dental implants. The aim of the present study was to first investigate how macrophages behaved on various dental implant surfaces and thereafter to investigate their effect on soft tissue cells. Macrophage adhesion, proliferation, and polarization towards either an M1 or M2 phenotype were investigated on six implant surfaces fabricated from pure titanium (Ti), pure zirconium (ZLA), and a titanium-zirconium (Ti-Zi) alloy of various surface topographies/chemistries. Thereafter, conditioned media (CM) collected from macrophages seeded on these various implant surfaces was cultured with murine gingival fibroblasts and investigated for their ability to promote collagen synthesis. Macrophages attached and proliferated in similar levels on all implant surfaces; however, the modSLA hydrophilic surfaces tended to decrease the pro-inflammatory response by lowering the gene expression of TNF-alpha, IL-1, and IL-6 and promoting tissue resolution through the expression of an M2-macrophage cytokine IL-10. Thereafter, CM from macrophages were seeded with gingival fibroblasts on each implant surface. In general, CM from macrophages significantly promoted gingival fibroblast cell attachment on all implant surfaces at either 4 or 8h and, most notably, significantly promoted fibronectin and TGF-beta gene expression on both Ti and Ti-Zi hydrophilic surfaces. The present study found that implant surface topography and chemistry substantially impacted macrophage behavior. Most notably, modifications via hydrophilicity to both the pure Ti and Ti-Zi were shown to favor the secretion of macrophage pro-resolution markers and favored subsequent gingival fibroblast cell behavior when cultured with CM, whereas surface composition (Ti vs ZLA vs Ti-Zi) had little effect on macrophage polarization or gingival fibroblast behavior. This finding suggests that surface hydrophilicity would improve the soft tissue integration of dental implants, irrespective of material composition.

Abstract 4456: Increased NTF2 levels in melanoma cell lines affect nuclear size and cancer cell characteristics

Abstract Xenopus studies have implicated two nuclear transport factors in the regulation of nuclear size: NTF2 and importin α. Importin α, a positive regulator of nuclear size, has been suggested as a biomarker in breast cancer and non-small cell lung carcinoma. We have focused our studies on NTF2. In different staged melanoma cell lines and tissue samples, we observed an inverse correlation between NTF2 levels and nuclear size. Compared to cancer cells, normal melanocytes exhibited the smallest nuclei and highest NTF2 levels. Based on transient transfection experiments in HeLa cells, MRC5 cells, and different melanoma cell lines, we found that increasing NTF2 expression levels reduces nuclear size. The largest effect was observed in WM3211 melanoma cells in which NTF2 expression reduced nuclear cross-sectional area by 40%. We next generated a stably transfected NTF2-inducible version of the metastatic melanoma cell line WM983B. By altering the doxycycline concentration, we can titrate the level of NTF2 protein, and we found that 20 ng/ml of doxycycline increases NTF2 levels by 5-fold and decreases the nuclear cross-sectional area by about 10%. Doxycycline-treated cells exhibited 3-fold higher rates of apoptosis and a 40% reduction in the rate of cell migration in a wound-healing assay. In vivo experiments were performed on RAG2 and NSG mice where NTF2-inducible cells were injected intravenously in order to examine metastatic potential. The number of lung metastases was reduced by 7-fold in doxycycline-treated mice compared to those that were not treated, suggesting that NTF2 overexpression suppresses metastatic potential. We are now testing the hypothesis that altering nuclear size by NTF2 expression leads to chromatin remodeling and altered gene expression. We performed RNAseq on doxycycline-treated and non-treated cells. Differentially expressed genes include those involved in cell migration (e.g. PRKX, LAMA5, ADAMTS15, ANK3, CERS6) and cell survival (e.g. RAMP1, WNK3, BMP5, TP63). Performing DNA FISH will show if the nuclear positioning of these genes is changed when nuclear size is reduced. We are now planning to test a combination therapy in mice in which we reduce nuclear size and treat with the well-established melanoma drug vemurafenib. Most melanoma patients with BRAF mutations show a good response to this drug, however relapse often occurs with drug-resistant melanoma cells expressing high levels of the cancer stem cell markers JARID1B, CD271, and fibronectin. According to our RNAseq data, cells expressing higher levels of NTF2 show reduced gene expression of JARID1B and fibronectin. Thus increasing NTF2 expression in drug-resistant tumors may improve prognosis and survival time. Citation Format: Lidija D. Vukovic, Bradley A. Stohr, Dan L. Levy. Increased NTF2 levels in melanoma cell lines affect nuclear size and cancer cell characteristics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4456.

NADPH Oxidase Nox5 Aggravates Renal Injury in Akita Mouse Model of Diabetic Nephropathy

Background: Renal reactive oxygen species (ROS) play an important role in mediating kidney injury in diabetes. Increasing evidence suggests that the pro-oxidant enzyme, Nox5 plays a significant role in human diabetic nephropathy (DN). Nox5 is present in humans and rabbits but not in mice or rats. Thus, there is a paucity of information about Nox5 in conventional animal models of DN. We examined the role of Nox5 in the insulin deficient diabetic Akita mice model using human inducible transgenic mice that express Nox5 selectively in endothelial cells (VEcad+Nox5+) or in mesangial cells (SM22+Nox5+). We also examined the endogenous expression of Nox5 in a high fat fed rabbit model of kidney disease. Methods: At week 10 mice were culled and kidneys were removed for the assessment of structural damage as well as gene and protein expression of markers of inflammation, fibrosis and oxidative stress. Protein expression of Nox5 and its localization in glomerular cells (endothelial and mesangial cells) were examined in transgenic mice by immunostaining. We also examined expression of pro-fibrotic gene in high fat fed rabbits by next generation sequencing (NGS) and RT-PCR and renal injury by histochemistry. Results: Expression of Nox5 was confirmed in glomerular endothelial and mesangial cells of transgenic mice. Diabetes induced increase in glomerulosclerosis, gene and protein expression of fibronectin and MCP-1 as well as nitrotyrosine were further increase in both diabetic Nox5 transgenic mice. Moreover, increased expression of Nox5 in high fat fed rabbits vs. normal diet fed rabbits was associated with increased expression of fibronectin, CTGF, collagen IV and VCAM-1 as well as increased mesangial expansion in the kidney. Conclusions: These findings in both transgenic mice model (endothelial and mesangial cells) suggest that Nox5 plays a significant role in mediating renal injury in diabetes. Disclosure J.C. Jha: None. A. Dai: None. M.E. Cooper: Advisory Panel; Self; AbbVie Inc.. Research Support; Self; Boehringer Ingelheim GmbH. Advisory Panel; Self; Boehringer Ingelheim Pharmaceuticals, Inc.. Speaker's Bureau; Self; Eli Lilly and Company. Advisory Panel; Self; Merck Sharp & Dohme Corp., AstraZeneca. Research Support; Self; Novo Nordisk A/S. Advisory Panel; Self; Novartis AG. R.M. Touyz: None. C. Kennedy: Research Support; Self; Prometic Life Sciences Inc.. K. Jandeleit-Dahm: None.

PBI-4050 Improves Metabolic Regulation and Diabetic Nephropathy through Reduction of ER Stress, Pro-Inflammatory/Fibrotic Markers, Galectin-3 Expression, and Inflammatory Cell Infiltration in ob/ob Mouse Model

Background: PBI-4050 displays anti-inflammatory/fibrotic properties with metabolic regulation. PBI-4050 has been shown to reduce glycated hemoglobin levels, and different biomarkers related to kidney and heart injury in a phase II open label clinical trial in patients suffering from type 2 diabetes with metabolic syndrome. PBI-4050 has also completed with success an open label phase II clinical trial in patients with idiopathic pulmonary fibrosis (IPF) and in patients with Alström Syndrome. The aim of this study was to investigate the effect of PBI-4050 on diabetic nephropathy in leptin deficient ob/ob mice, a model of type 2 diabetes and metabolic syndrome. Methods: ob/ob mice were treated with vehicle or PBI-4050 (200 mg/kg, oral once a day) from day 1 to 105. OGTT, triglycerides, adiponectin and serum insulin levels, as well as inflammatory cell infiltration and pro-inflammatory/fibrotic gene expression and histology of kidney and white adipose tissue (WAT) were examined. Results: PBI-4050 improved glucose metabolism, reduced serum triglycerides and insulin levels, and increased serum adiponectin levels. In kidneys, PBI-4050 reduced ER stress (p-PERK, ATF-6, CHOP and p-IRE1). Furthermore, PBI-4050 reduced α-SMA, fibronectin and CTGF gene expression. Pro-inflammatory/remodeling markers expression (MRC-1, MCP-1 and MMP-2) were also reduced with PBI-4050 treatment. Moreover, histological analysis revealed that PBI-4050 reduced collagen deposition in glomeruli. Specific immunostaining also showed that PBI-4050 significantly reduced galectin-3 expression in kidney and WAT. Finally, PBI-4050 reduced the expression levels of inflammatory cell infiltration markers (Ly6G and F4/80) in kidney. Conclusions: These results suggest that PBI-4050 is a strong potential candidate for the treatment of metabolic diseases and related diabetic nephropathy. Disclosure J. Simard: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. M. Cloutier: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. A. Laverdure: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. J. Richard: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. L. Gervais: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. A. Felton: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. B. Grouix: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. P. Laurin: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc.. Board Member; Self; Prometic Life Sciences Inc. M. Leduc: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. F.A. Leblond: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc. L. Gagnon: Employee; Self; Prometic Biosciences Inc.. Stock/Shareholder; Self; Prometic Life Sciences Inc..

KLF10 Gene Expression Modulates Fibrosis in Dystrophic Skeletal Muscle

Dystrophic skeletal muscle is characterized by fibrotic accumulation of extracellular matrix components that compromise muscle structure, function, and capacity for regeneration. Tissue fibrosis is often initiated and sustained through transforming growth factor-β (TGF-β) signaling, and Krüppel-like factor 10 (KLF10) is an immediate early gene that is transcriptionally activated in response to TGF-β signaling. It encodes a transcriptional regulator that mediates the effects of TGF-β signaling in a variety of cell types. This report presents results of investigation of the effects of loss of KLF10 gene expression in wild-type and dystrophic (mdx) skeletal muscle. On the basis of RT-PCR, Western blot, and histological analyses of mouse tibialis anterior and diaphragm muscles, collagen type I (Col1a1) and fibronectin gene expression and protein deposition were increased in KLF10-/- mice, contributing to increased fibrosis. KLF10-/- mice displayed increased expression of genes encoding SMAD2, SMAD3, and SMAD7, particularly in diaphragm muscle. SMAD4 gene expression was unchanged. Expression of the extracellular matrix remodeling genes, MMP2 and TIMP1, was also increased in KLF10-deficient mouse muscle. Histological analyses and assays of hydroxyproline content indicated that the loss of KLF10 increased fibrosis. Dystrophic KLF10-null mice also had reduced grip strength. The effects of loss of KLF10 gene expression were most pronounced in dystrophic diaphragm muscle, suggesting that KLF10 moderates the fibrotic effects of TGF-β signaling in chronically damaged regenerating muscle.

Cysteine Oxidative Dynamics Underlies Hypertension and Kidney Dysfunction Induced by Chronic Intermittent Hypoxia.

Previous data showed the lack of efficacy of an adrenoceptor antagonist to revert hypertension induced by chronic intermittent hypoxia (CIH). We hypothesized that, in addition to sympathetic activation, CIH may change the availability and dynamics of cysteine. Temporal variation in total cysteine and its fractions, free reduced, free oxidized and protein-bound (CysSSP), were measured in homogenates of kidney cortex and medulla of Wistar rats. Animals were exposed to CIH for 14, 21 and 60 days and cysteine fractions and fibronectin gene expression were assessed at these time-points. Two different phases in cysteine dynamics were identified. An early phase (14d) characterized by an increase in cysteine oxidation and CysSSP forms. Late events (>21d) were characterized by a global reduction in cysteine, minimum level of CysSSP and maximum overexpression of fibronectin in kidney cortex. In conclusion, cysteine dynamics is influenced by the duration of CIH exposure: first there is a cysteine disulfide stress-like adaptive response followed by a progressive loss of cysteine availability and a decrease in CysSSP fraction. Kidney fibrosis associated to an unbalance in cysteine dynamics might contribute to the inefficacy of available antihypertensive drugs in patients with delayed diagnosis of sleep apnea.

Docosahexaenoic acid attenuates carbon tetrachloride-induced hepatic fibrosis in rats

Fish oil containing docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) has been reported to exert beneficial health effects, including hepatoprotection. However, the effect of DHA alone has not been well studied, and the mechanism is not fully understood. In the present study, we reported the protective effect of DHA on carbon tetrachloride (CCl4) induced hepatic fibrosis. Compared with the control group, the CCl4 group showed hepatic damage as evidenced by histological changes and elevation in serum transaminase activity, fibrosis, inflammation and oxidative stress levels. These pathophysiological changes were attenuated by chronic DHA supplementation. The anti-fibrotic effect of DHA was accompanied by reductions in gene and protein expression of α-smooth muscle actin (α-SMA), fibronectin, and collagen in the liver tissue. DHA also attenuated CCl4-induced elevation of lipid peroxidation (LPO) and decrease of glutathione (GSH)/oxidized GSH (GSSG) ratio. The upregulated inflammatory cytokines tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-6 by CCl4 were also ameliorated by DHA. Peroxisome proliferator-activated receptor (PPAR)-γ upregulation and type I and II receptors for transforming growth factor (TGF)-β (Tβ-RI and Tβ-RII) and platelet-derived growth factor (PDGF)-β receptor (PDGF-βR) downregulation on both mRNA and protein levels were observed by DHA treatment compared to CCl4 group. Moreover, in vitro study showed that DHA inhibited HSC activation, being associated with elevating PPARγ level and reducing the phosphorylation levels of Smad2/3 and ERKs, which are downstream intermediates of TGFβ and PDGF receptors, respectively. Taken together, the hepatoprotective, anti-inflammatory and anti-fibrotic effects of DHA appeared to be multifactorial. Further, one of the mechanisms of the anti-fibrotic effect of chronic DHA supplementation is probably through PPARγ signaling to interrupt TGFβ/Smad and PDGF/ERK pathways in HSCs.

Molecular mechanism of total flavonoids in Isodon amethystoides on adjuvant arthritis in rats

Our preliminary study showed that the total flavonoids in Isodon amethystoides(TFIA), a local medicinal herb in Suzhou, had a certain therapeutic effect on adjuvant arthritis, and this therapeutic effect may be achieved through the up-regulation of miR-152 expression. In this paper, the molecular mechanism of TFIA on the pathogenesis of adjuvant arthritis(AA) rats was further studied. AA rats were prepared with complete Freund's adjuvant, and then treated with TFIA by intragastric administration. Real-time qPCR was used to detect the effects of TFIA on the negative regulatory loop of miR-152, methylase DNMT1 and methyl-CpG binding protein MeCP2 in fibroblast like synoviocytes(FLS) of AA rats, as well as the effects of TFIA on the classic Wnt signaling pathway and the expression of fibronectin gene in AA rats. Intragastric administration of TFIA significantly inhibited the expression of DNMT1 and reversed the negative regulatory loop composed of miR-152, DNMT1 and MeCP2 in the pathology of AA rats. After transfection of miR-152 inhibitors into the FLS in treatment group, DNMT1 expression was significantly restored. TFIA significantly up-regulated the expression of SFRP4 and inhibited the expression of β-catenin, C-myc and ccnd1, the key genes of canonical Wnt signaling pathway. TFIA also significantly inhibited the expression of fibronectin, an AA gene. The effect of TFIA on the expression of SFRP4, β-catenin, C-myc, ccnd1 and fibronectin was reversed after transfection with miR-152 inhibitors in the treatment group FLS. TFIA may inhibit the DNMT1 expression, up-regulate the SFRP4 expression, inhibit the expression of classical Wnt signaling genes β-catenin, C-myc, and ccnd1 as well as the RA gene fibronectin expression through the up-regulation of miR-152 expression.

Response of Dermal Fibroblasts to Biochemical and Physical Cues in Aligned Polycaprolactone/Silk Fibroin Nanofiber Scaffolds for Application in Tendon Tissue Engineering.

Silk fibroin (SF) and fiber alignment were introduced into polycaprolactone (PCL)-based electrospun nanofibers as chemical and physical cues for tendon tissue engineering applications. The physicochemical properties of random PCL (RP) nanofibers, random PCL/SF (RPSF) nanofibers and aligned PCL/SF (APSF) nanofibers were characterized for fiber orientation and SF blending effects. An in vitro cell culture with rabbit dermal fibroblasts (RDFBs) on nanofibers indicated that SF promotes cell proliferation to a higher extent than fiber alignment. Cells aligned in the direction of fiber axes could be confirmed through scanning electron microscopy (SEM) observation and cytoskeleton staining. The quantitative real-time polymerase chain reaction (qRT-PCR) experiments indicated up-regulated gene expression of tendon marker proteins (type I collagen (Col I), fibronectin and biglycan) on APSF nanofibers and tendon reconstruction was confirmed from Col III gene expression. Animal experiments with Achilles tendon defect repairs in rabbits were carried out with RPSF and APSF scaffolds. The beneficial effects of fiber alignment were verified from histological and immunohistochemical staining, where cell migration and extracellular matrix protein deposition tend to stretch in a parallel direction along the axial direction of APSF nanofibers with enhanced Col I and tenascin C production. Biomechanical testing indicated the tensile stiffness and maximum load of cell-seeded APSF scaffolds were 60.2 and 81.3% of normal tendon values, respectively, which are significantly higher than cell-seeded RPSF or acellular APSF and RPSF scaffolds. These results suggest that APSF nanofiber scaffolds combined with RDFBs have the potential to repair the gap defects of Achilles tendons in vivo and to effectively restore the function and structure of tendons.

The association of vimentin and fibronectin gene expression with epithelial-mesenchymal transition and tumor malignancy in colorectal carcinoma.

Colorectal cancer is the most common malignancy of the gastrointestinal tract with very high mortality. One of the most distinguishing features for the establishment of an epithelial-mesenchymal transition phenotype is the alteration of mesenchymal markers expression and structural adhesion proteins. We evaluated the significance of vimentin and fibronectin gene expression in relation to invasion and metastasis in CRC patients. Tissue specimens were collected consecutively from forty-five colorectal carcinoma patients during surgeries. Tissues were divided into two separate parts for pathological and molecular assays. In order to histological staging, tissue sections were prepared from formalin-fixed paraffin-embedded blocks and stained with Hematoxylin and Eosin. To quantify gene expression, specimens were dissected and homogenized. Moreover, SW480, SW48, SW948, Caco-2, HT-29 and LS174T as human colon cancer cell lines were obtained and cultured, then molecular analyzing was performed. As results the expression of VIM gene increased in SW480, SW48 and SW948 while it decreased in Caco-2, HT-29 and LS174T. Moreover, FN was up-regulated in Caco-2, HT-29 and SW948, while it was down-regulated in SW480, SW48 and LS174T. In tissues, vimentin and fibronectin expression significantly increased in stromal cells, whereas vimentin decreased in colonic epithelial cells and fibronectin had no significant change. Vimentin and fibronectin expression were changed in tumor tissues. It was found an association between vimentin expression with age and tumor size; over-expression in older age and decreasing in larger tumor size. Furthermore, fibronectin over-expression is correlated to older age and high tumor stages; up-regulation with increasing age and high tumor stages.

Lipopolysaccharide can modify differentiation and immunomodulatory potential of periodontal ligament stem cells via ERK1,2 signaling.

Lipopolysaccharide (LPS) is a pertinent deleterious factor in oral microenvironment for cells which are carriers of regenerative processes. The aim of this study was to investigate the emerging in vitro effects of LPS (Escherichia coli) on human periodontal ligament stem cell (PDLSC) functions and associated signaling pathways. We demonstrated that LPS did not affect immunophenotype, proliferation, viability, and cell cycle of PDLSCs. However, LPS modified lineage commitment of PDLSCs inhibiting osteogenesis by downregulating Runx2, ALP, and Ocn mRNA expression, while stimulating chondrogenesis and adipogenesis by upregulating Sox9 and PPARγ mRNA expression. LPS promoted myofibroblast-like phenotype of PDLSCs, since it significantly enhanced PDLSC contractility, as well as protein and/or gene expression of TGF-β, fibronectin (FN), α-SMA, and NG2. LPS also increased protein and gene expression levels of anti-inflammatory COX-2 and pro-inflammatory IL-6 molecules in PDLSCs. Inhibition of peripheral blood mononuclear cells (MNCs) transendothelial migration in presence of LPS-treated PDLSCs was accompanied by the reduction of CD29 expression within MNCs. However, LPS treatment did not change the inhibitory effect of PDLSCs on mitogen-stimulated proliferation of CD4+ and the ratio of CD4+ CD25high /CD4+ CD25low lymphocytes. LPS-treated PDLSCs did not change the frequency of CD34+ and CD45+ cells, but decreased the frequency of CD33+ and CD14+ myeloid cells within MNCs. Moreover, LPS treatment attenuated the stimulatory effect of PDLSCs on CFC activity of MNCs, predominantly the CFU-GM number. The results indicated that LPS-activated ERK1,2 was at least partly involved in the observed effects on PDLSC differentiation capacity, acquisition of myofibroblastic attributes, and changes of their immunomodulatory features.

Secretion of extracellular matrix were inhibited by Exendin-4 treatment through MAPK-NF-κB related inflammation in high glucose-induced glomerular mesangial cells

Objective To explore the effects and related mechanism of Exendin-4 on secretion of extracellular matrix in high glucose-induced glomerular mesangial cells(GMCs). Methods GMCs were incubated in medium with glucose or Exendin-4 for the four groups: normal glucose group(NG group): cells were treated in medium with 5.6 mmol/L glucose; NG with Exendin-4 treatment group(NGE group): cells were treated with 5.6 mmol/L glucose and Exendin-4; high glucose group(HG group): cells were cultured with 30 mmol/L glucose; HG with Exendin-4 treatment group(HGE group): cells were treated with 30 mmol/L glucose and Exendin-4 at concentration of 3, 5, 10, 15, 30 nmol/L separately, which were cultured for 12, 24, 48 hours. GMCs treated with Exendin-4 were determined by assessing proliferation using a CCK8 method. The levels of fibronectin(FN), collagen type Ⅳ(Col-Ⅳ)in the cell supernatant were measured using enzyme-linked immunosorbent assay(ELISA). The gene levels of Col-Ⅳ, FN, and expression of inflammatory mediators including monocyte chemotactic protein 1(MCP-1), tumor necrosis factor-α(TNF-α), intercellular cell adhesion molecule-1(ICAM-1), transforming growth factor-β1(TGF-β1)were evaluated using reverse transcription PCR(RT-PCR); The expression of nuclear transcription factor-κB(NF-κB), glucagon-like peptide-l receptor(GLP-1R), and phosphorylation levels of mitogen-activated protein kinases(MAPKs)were evaluated by Western blot. Results (1)After treatment with 10 nmol/L Exendin-4 for 24 hour, the proliferation rate of GMCs was significantly decreased compared with 3 nmol/L, 5 nmol/L Exendin-4 treatment(P 0.05). (2)The gene expression of FN, Col-Ⅳ and the inflammatory mediators, MCP-1, TNF-α, ICAM-1, TGF-β1 in HG group were significantly increased compared with the NG group, (all P<0.05). After treatment with Exendin-4, the levels of FN, Col-Ⅳ and the gene expression of TNF-α, MCP-1, ICAM-1, TGF-β1 were decreased(all P<0.05). (3)Compared with NG group, the expression of NF-κB and the phosphorylation of extracellular regulated protein kinases(p-Erk1/2), Jun N-terminal kinase(p-JNK)and, p38MAPK(p-p38MAPK)in the group of HG group were increased significantly, accompanied by the decrease of GLP-1R protein level(all P<0.05). Importantly, Exendin-4 treatment significantly reduced protein expression of p-Erk1/2, p-JNK, and NF-κB(all P<0.05), and the level of GLP-1R protein increased(P<0.05). Furthermore, specific Erk1/2, JNK or NF-κB inhibitors markedly blocked Exendin-4-mediated decrease in the levels of FN, Col-Ⅳ. Conclusion Exendin-4 treatment inhibits the secretion of extracellular matrix potentially through Erk1/2, JNK/NF-κB signaling in higher glucose induced GMCs. (Chin J Endocrinol Metab, 2017, 33: 220-227) Key words: Exendin-4; Glomerular mesangial cells; Mitogen-activated protein kinase; Nuclear transcription factor-κB; Extracellular matrix

Smad3-dependent CCN2 mediates fibronectin expression in human skin dermal fibroblasts.

The potential involvement of connective tissue growth factor (CCN2/CTGF) in extracellular matrix (ECM) production is recognized. However, the role CCN2 in fibronectin (FN) gene expression has remained incompletely understood and even controversial. Here we report that CCN2 is absolutely necessary for FN expression in primary human skin dermal fibroblasts, the major cells responsible for ECM production in skin. Gain- and loss-of-function approaches demonstrate that CCN2 is an essential component of FN expression in both basal and stimulation by TGF-β signaling, the major regulator of FN expression. CCN2 is significantly induced by Smad3, a critical mediator of TGF-β signaling. CCN2 acts as a downstream mediator of TGF-β/Smad signaling and acting synergistically with TGF-β to regulate FN gene expression. Finally, we observed that CCN2 and FN predominantly expressed in the dermis of normal human skin, stromal tissues of skin squamous cell carcinoma (SCC), and simultaneously induced in wounded human skin in vivo. These findings provide evidence that CCN2 is responsible for mediating the stimulatory effects of TGF-β/Smad on FN gene expression, and attenuation of CCN2 expression may benefit to reduce fibrotic ECM microenvironment in disease skin.

Cerebrovascular Remodeling and Neuroinflammation is a Late Effect of Radiation-Induced Brain Injury in Non-Human Primates.

Fractionated whole-brain irradiation (fWBI) is a mainstay of treatment for patients with intracranial neoplasia; however late-delayed radiation-induced normal tissue injury remains a major adverse consequence of treatment, with deleterious effects on quality of life for affected patients. We hypothesize that cerebrovascular injury and remodeling after fWBI results in ischemic injury to dependent white matter, which contributes to the observed cognitive dysfunction. To evaluate molecular effectors of radiation-induced brain injury (RIBI), real-time quantitative polymerase chain reaction (RT-qPCR) was performed on the dorsolateral prefrontal cortex (DLPFC, Brodmann area 46), hippocampus and temporal white matter of 4 male Rhesus macaques (age 6-11 years), which had received 40 Gray (Gy) fWBI (8 fractions of 5 Gy each, twice per week), and 3 control comparators. All fWBI animals developed neurologic impairment; humane euthanasia was elected at a median of 6 months. Radiation-induced brain injury was confirmed histopathologically in all animals, characterized by white matter degeneration and necrosis, and multifocal cerebrovascular injury consisting of perivascular edema, abnormal angiogenesis and perivascular extracellular matrix deposition. Herein we demonstrate that RIBI is associated with white matter-specific up-regulation of hypoxia-associated lactate dehydrogenase A (LDHA) and that increased gene expression of fibronectin 1 (FN1), SERPINE1 and matrix metalloprotease 2 (MMP2) may contribute to cerebrovascular remodeling in late-delayed RIBI. Additionally, vascular stability and maturation associated tumor necrosis super family member 15 (TNFSF15) and vascular endothelial growth factor beta (VEGFB) mRNAs were increased within temporal white matter. We also demonstrate that radiation-induced brain injury is associated with decreases in white matter-specific expression of neurotransmitter receptors SYP, GRIN2A and GRIA4. We additionally provide evidence that macrophage/microglial mediated neuroinflammation may contribute to RIBI through increased gene expression of the macrophage chemoattractant CCL2 and macrophage/microglia associated CD68. Global patterns in cerebral gene expression varied significantly between regions examined (P < 0.0001, Friedman's test), with effects most prominent within cerebral white matter.

836 - The activity of intravesical hyaluronic acid and chondroitin sulfate administration on urothelial gene expression. Preliminary results on the epidermal growth factor receptor and fibronectin gene expression evaluated in bladder washings of patients affected by non muscle-invasive bladder cancer

836 - The activity of intravesical hyaluronic acid and chondroitin sulfate administration on urothelial gene expression. Preliminary results on the epidermal growth factor receptor and fibronectin gene expression evaluated in bladder washings of patients affected by non muscle-invasive bladder cancer

Trichostatin A attenuates ventilation-augmented epithelial-mesenchymal transition in mice with bleomycin-induced acute lung injury by suppressing the Akt pathway.

BackgroundMechanical ventilation (MV) used in patients with acute respiratory distress syndrome (ARDS) can cause diffuse lung inflammation, an effect termed ventilator-induced lung injury, which may produce profound pulmonary fibrogenesis. Histone deacetylases (HDACs) and serine/threonine kinase/protein kinase B (Akt) are crucial in modulating the epithelial–mesenchymal transition (EMT) during the reparative phase of ARDS; however, the mechanisms regulating the interactions among MV, EMT, HDACs, and Akt remain unclear. We hypothesized that trichostatin A (TSA), a HDAC inhibitor, can reduce MV-augmented bleomycin-induced EMT by inhibiting the HDAC4 and Akt pathways.MethodsFive days after bleomycin treatment to mimic acute lung injury (ALI), wild-type or Akt-deficient C57BL/6 mice were exposed to low-tidal-volume (low-VT, 6 mL/kg) or high-VT (30 mL/kg) MV with room air for 5 h after receiving 2 mg/kg TSA. Nonventilated mice were examined as controls.ResultsFollowing bleomycin exposure in wild-type mice, high-VT MV induced substantial increases in microvascular leaks; matrix metalloproteinase-9 (MMP-9) and plasminogen activator inhibitor-1 proteins; free radical production; Masson’s trichrome staining; fibronectin, MMP-9, and collagen 1a1 gene expression; EMT (identified by increased localized staining of α-smooth muscle actin and decreased staining of E-cadherin); total HDAC activity; and HDAC4 and Akt activation (P < 0.05). In Akt-deficient mice, the MV-augmented lung inflammation, profibrotic mediators, EMT profiles, Akt activation, and pathological fibrotic scores were reduced and pharmacologic inhibition of HDAC4 expression was triggered by TSA (P < 0.05).ConclusionsOur data indicate that TSA treatment attenuates high-VT MV-augmented EMT after bleomycin-induced ALI, in part by inhibiting the HDAC4 and Akt pathways.

Minireview: Fibronectin in retinal disease.

Retinal fibrosis, characterized by dysregulation of extracellular matrix (ECM) protein deposition by retinal endothelial cells, pigment epithelial cells, and other resident cell-types, is a unifying feature of several common retinal diseases. Fibronectin is an early constituent of newly deposited ECM and serves as a template for assembly of other ECM proteins, including collagens. Under physiologic conditions, fibronectin is found in all layers of Bruch's membrane. Proliferative vitreoretinopathy (PVR), a complication of retinal surgery, is characterized by ECM accumulation. Among the earliest histologic manifestations of diabetic retinopathy (DR) is capillary basement membrane thickening, which occurs due to perturbations in ECM homeostasis. Neovascularization, the hallmark of late stage DR as well as exudative age-related macular degeneration (AMD), involves ECM assembly as a scaffold for the aberrant new vessel architecture. Rodent models of retinal injury demonstrate a key role for fibronectin in complications characteristic of PVR, including retinal detachment. In mouse models of DR, reducing fibronectin gene expression has been shown to arrest the accumulation of ECM in the capillary basement membrane. Alterations in matrix metalloproteinase activity thought to be important in the pathogenesis of AMD impact the turnover of fibronectin matrix as well as collagens. Growth factors involved in PVR, AMD, and DR, such as PDGF and TGFβ, are known to stimulate fibronectin matrix assembly. A deeper understanding of how pathologic ECM deposition contributes to disease progression may help to identify novel targets for therapeutic intervention.

Paracrine IL-6 signaling mediates the effects of pancreatic stellate cells on epithelial-mesenchymal transition via Stat3/Nrf2 pathway in pancreatic cancer cells

BackgroundWe previously showed that pancreatic stellate cells (PSC) secreted interleukin (IL)-6 and promoted pancreatic ductal adenocarcinoma (PDAC) cell proliferation via nuclear factor erythroid 2 (Nrf2)-mediated metabolic reprogramming. Epithelial-mesenchymal transition (EMT) is a key process for the metastatic cascade. To study the mechanism of PDAC progression to metastasis, we investigated the role of PSC-secreted IL-6 in activating EMT and the involvement of Nrf2 in this process. MethodsGene expression of IL-6 and IL-6Rα in PSC and PDAC cells was measured with qRT-PCR. The role of PSC-secreted IL-6, JAK/Stat3 signaling, and Nrf2 mediation on EMT-related genes expression was also examined with qRT-PCR. EMT phenotypes were assessed with morphological change, wound healing, migration, and invasion. ResultsPSC expressed higher mRNA levels of IL-6 but lower IL-6Rα compared to PDAC cells. Neutralizing IL-6 in PSC secretion reduced mesenchymal-like morphology, migration and invasion capacity, and mesenchymal-like gene expression of N-cadherin, vimentin, fibronectin, collagen I, Sip1, Snail, Slug, and Twist2. Inhibition of JAK/Stat3 signaling induced by IL-6 repressed EMT and Nrf2 gene expression. Induction of Nrf2 activity by tert-butylhydroquinone (tBHQ) increased both EMT phenotypes and gene expression (N-cadherin, fibronectin, Twist2, Snail, and Slug) repressed by IL-6 neutralizing antibody. Simultaneous inhibition of Nrf2 expression with siRNA and Stat3 signaling further repressed EMT gene expression, indicating that Stat3/Nrf2 pathway mediates EMT induced by IL-6. ConclusionsIL-6 from PSC promotes EMT in PDAC cells via Stat3/Nrf2 pathway. General significanceTargeting Stat3/Nrf2 pathway activated by PSC-secreted IL-6 may provide a novel therapeutic option to improve the prognosis of PDAC.

Regulation of fibronectin gene expression in cardiac fibroblasts by scleraxis.

The glycoprotein fibronectin is a key component of the extracellular matrix. By interacting with numerous matrix and cell surface proteins, fibronectin plays important roles in cell adhesion, migration and intracellular signaling. Up-regulation of fibronectin occurs in tissue fibrosis, and previous studies have identified the pro-fibrotic factor TGFβ as an inducer of fibronectin expression, although the mechanism responsible remains unknown. We have previously shown that a key downstream effector of TGFβ signaling in cardiac fibroblasts is the transcription factor scleraxis, which in turn regulates the expression of a wide variety of extracellular matrix genes. We noted that fibronectin expression tracked closely with scleraxis expression, but it was unclear whether scleraxis directly regulated the fibronectin gene. Here, we report that scleraxis acts via two E-box binding sites in the proximal human fibronectin promoter to govern fibronectin expression, with the second E-box being both sufficient and necessary for scleraxis-mediated fibronectin expression to occur. A combination of electrophoretic mobility shift and chromatin immunoprecipitation assays indicated that scleraxis interacted to a greater degree with the second E-box. Over-expression or knockdown of scleraxis resulted in increased or decreased fibronectin expression, respectively, and scleraxis null mice presented with dramatically decreased immunolabeling for fibronectin in cardiac tissue sections compared to wild-type controls. Furthermore, scleraxis was required for TGFβ-induced fibronectin expression: TGFβ lost its ability to induce fibronectin expression following scleraxis knockdown. Together, these results demonstrate a novel and required role for scleraxis in the regulation of cardiac fibroblast fibronectin gene expression basally or in response to TGFβ.

Eosinophils enhance WNT-5a and TGF-β1 genes expression in airway smooth muscle cells and promote their proliferation by increased extracellular matrix proteins production in asthma

BackgroundRecent studies have suggested that eosinophils may have a direct effect on airway smooth muscle cells (ASMC), causing their proliferation in patients with asthma, but the precise mechanism of the interaction between these cells remains unknown. We propose that changes in Wnt signaling activity and extracellular matrix (ECM) production may help explain these findings. Therefore, the aim of this study was to investigate the effect of eosinophils from asthmatic and non-asthmatic subjects on Wnt-5a, transforming growth factor β1 (TGF-β1), and ECM protein (fibronectin and collagen) gene expression and ASMC proliferation.MethodsA total of 18 subjects were involved in the study: 8 steroid-free asthma patients and 10 healthy subjects. Peripheral blood eosinophils were isolated using centrifugation and magnetic separation. An individual co-culture of eosinophils with human ASMC was prepared for each study subject. Adhesion of eosinophils to ASMC (evaluated by assaying eosinophil peroxidase activity) was determined following various incubation periods (30, 45, 60, 120, and 240 min). The expression of Wnt-5a, TGF-β1, and ECM protein genes in ASMC was measured using quantitative real-time polymerase chain reaction (PCR) after 24 h of co-culture. Proliferation of ASMC was measured using the Alamar blue method after 48 h and 72 h of co-culture with eosinophils.ResultsEosinophils from asthmatic subjects demonstrated increased adhesion to ASMC compared with eosinophils from healthy subjects (p < 0.05) in vitro. The expression of Wnt-5a, TGF-β1, collagen, and fibronectin genes in ASMC was significantly higher after 24 h of co-culture with eosinophils from asthmatic subjects, while co-culture of ASMC with eosinophils from healthy subjects increased only TGF-β1 and fibronectin gene expression. ASMC proliferation was augmented after co-culture with eosinophils from asthma patients compared with co-culture with eosinophils from healthy subjects (p < 0.05).ConclusionsEosinophils enhance Wnt-5a, TGF-β1, fibronectin, and collagen gene expression in ASMC and promote proliferation of these cells in asthma.Trial registrationClinicalTrials.gov Identifier: NCT02648074.