Bevacizumab and anexelekto inhibitor, TP-0903 inhibits TGF-β1-induced epithelial-mesenchymal transition of colon cancer cells

The incidence of colorectal cancer (CRC) is reported to be increasing nowadays, with a large proportion of newly diagnosed CRC patients being affected by metastasis. Epithelial-mesenchymal transition (EMT) is an important event in the development of metastasis of CRC. In this study, we investigated whether the anticancer drug bevacizumab and anexelekto inhibitor, TP-0903, regulate EMT of colon cancer cells induced by transforming growth factor-beta 1 (TGF-β1). Using quantitative real-time PCR and western blot analysis, we found that bevacizumab and TP-0903 decreased the expression levels of fibronectin, alpha-smooth muscle actin, and vimentin, whereas they restored E-cadherin expression in TGF-β1-exposed SW480 and HCT116 cells. In addition, we elucidated that bevacizumab and TP-0903 inhibited the migration and invasion of TGF-β1-exposed colon cancer cells using scratched wound healing, transwell migration, and Matrigel-coated invasion assays. Finally, we discovered that bevacizumab and TP-0903 inactivated the Smad 2/3 signaling pathway in TGF-β1-exposed SW480 and HCT116 cells. Therefore, we suggest that treatment of bevacizumab and TP-0903 inhibits TGF-β1-induced EMT of colon cancer cells through inactivation of the Smad 2/3 signaling pathway.

Curcumin suppresses renal carcinoma tumorigenesis by regulating circ-FNDC3B/miR-138-5p/IGF2 axis

Curcumin has a vital role in the development of renal carcinoma. Nevertheless, the mechanism of curcumin in renal carcinoma tumorigenesis remains largely unknown. Thirty renal carcinoma patients were recruited. Renal carcinoma cell lines CAKI-1 and ACHN were exposed to curcumin. The levels of circular RNA fibronectin type III domain-containing protein 3B (circ-FNDC3B), microRNA (miR)-138-5p and insulin-like growth factor 2 (IGF2) were detected via quantitative reverse transcription PCR or western blot. Cell proliferation and apoptosis were investigated via 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide, colony formation analysis, flow cytometry and western blot. Target association between miR-138-5p and circ-FNDC3B or IGF2 was analyzed via dual-luciferase reporter analysis. The function of curcumin in vivo was assessed via a xenograft model. circ-FNDC3B level was enhanced and miR-138-5p abundance was declined in renal carcinoma tissues and cells. Curcumin restrained renal carcinoma cell proliferation and promoted apoptosis. circ-FNDC3B overexpression or miR-138-5p knockdown weakened the influence of curcumin. circ-FNDC3B knockdown hindered cell proliferation and promoted apoptosis by increasing miR-138-5p. IGF2 was targeted via miR-138-5p and positively regulated via circ-FNDC3B. Curcumin decreased xenograft tumor growth via reducing circ-FNDC3B in vivo. Curcumin suppressed renal carcinoma tumorigenesis in vitro and in vivo via regulating circ-FNDC3B/miR-138-5p/IGF2 axis, proposing new insight into renal carcinoma tumorigenesis.

Addition of EP2 agonists to an FP agonist additively and synergistically modulates adipogenesis and the physical properties of 3D 3T3-L1 sphenoids

The additive effects of prostaglandin (PG)-EP2 agonists on a PG-FP agonist toward adipogenesis in two- or three-dimension (2D or 3D) cultures of 3T3-L1 cells was examined by lipid staining, the mRNA expression of adipogenesis related genes, and extracellular matrixes (ECMs) including collagen molecules (Col) -1, -4 and -6, and fibronectin (Fn), and the sizes and physical properties of 3D sphenoids, as measured by a micro-squeezer. The results indicate that adipogenesis induced 1) an enlargement in the sizes of 3D sphenoids, 2) a substantial enhancement in lipid staining, the expression of the PParγ, Ap2 and Leptin genes, and 3) a significant decrease in the stiffness of the 3D sphenoids. These effects were inhibited by bimatoprost acid (BIM-A), but 4) adipogenesis induced significant down-regulation of Col1 and Fn, and the significant up-regulation of the Col4 and Col6 genes were unchanged by BIM-A. On the addition of an EP2 agonist, such as omidenepag (OMD) or butaprost (Buta), to BIM-A, 1) the sizes of the 3D sphenoids were further decreased, 2) lipid staining was decreased (2D; OMD, 3D; Buta) 3) the stiffness of the 3D sphenoids was increased by Buta, 4) the expression of PParγ was up-regulated (2D; Buta) or unchanged (3D), the expression of Ap2 was down-regulated (2D; OMD) or up-regulated (3D; Buta), and the expression of Leptin was increased (2D), 5) the expression of all four (OMD) or all except Col4 (buta) in 2D, and Col1and Col4 (OMD) in 3D were up-regulated. These collective findings indicate that the addition of an EP2 agonist, OMD or Buta significantly modulated the BIM-A induced suppression of adipogenesis as well as physical properties of 2D and 3D cultured 3T3-L1 cells in different manners.

Oxidation of human plasma fibronectin by inflammatory oxidants perturbs endothelial cell function

Dysfunction of endothelial cells of the artery wall is an early event in cardiovascular disease and atherosclerosis. The cause(s) of this dysfunction are unresolved, but accumulating evidence suggests that oxidants arising from chronic low-grade inflammation are contributory agents, with increasing data implicating myeloperoxidase (MPO, released by activated leukocytes), and the oxidants it generates (e.g. HOCl and HOSCN). As these are formed extracellularly and react rapidly with proteins, we hypothesized that MPO-mediated damage to the matrix glycoprotein fibronectin (FN) would modulate FN structure and function, and its interactions with human coronary artery endothelial cells (HCAEC). Exposure of human plasma FN to HOCl resulted in modifications to FN and its functional epitopes. A dose-dependent loss of methionine and tryptophan residues, together with increasing concentrations of methionine sulfoxide, and modification of the cell-binding fragment (CBF) and heparin-binding fragment (HBF) domains was detected with HOCl, but not HOSCN. FN modification resulted in a loss of HCAEC adhesion, impaired cell spreading and reduced cell proliferation. Exposure to HCAEC to HOCl-treated FN altered the expression of HCAEC genes associated with extracellular matrix (ECM) synthesis and adhesion. Modifications were detected on HCAEC-derived ECM pre-treated with HOCl, but not HOSCN, with a loss of antibody recognition of the CBF, HBF and extra-domain A. Co-localization of epitopes arising from MPO-generated HOCl and cell-derived FN was detected in human atherosclerotic lesions. Damage was also detected on FN extracted from lesions. These data support the hypothesis that HOCl, but not HOSCN, targets and modifies FN resulting in arterial wall endothelial cell dysfunction.

Carboxytherapy: Controls the inflammation and enhances the production of fibronectin on wound healing under venous insufficiency

To examine the influence of carboxytherapy on wound healing under venous insufficiency, full-thickness excisional wounds were created on Wistar rats. We used three groups with 32 rats each: Group (I): daily cleaning with 0.9% saline solution; Group Sulfadiazine (II): 1% silver sulfadiazine; and Carboxytherapy (III): subcutaneous application of 0.3 mL of carbon dioxide. The predetermined periods of analysis were the 3rd, 7th, 14th, and 30th day. The slides were stained with haematoxylin and eosin and Picrosirius red and submitted for immunohistochemistry. Groups II and III presented a statistically significant decrease in relation to the presence of neutrophilic and lymphocytic infiltrates. The presence of collagen significant increased in groups II and III. However, group III presented better organisation. Only group I maintained the neovascularisation until the 30th day. The new epithelium statistically significantly increased in groups II and III. On immunohistochemistry, regarding fibronectin expression, only group III demonstrated a statistically significant increase since the beginning of the healing process. Thus, the use of carboxytherapy promotes the formation of a tissue better structured and that may be an important resource for the treatment of wounds under venous insufficiency, especially those of recurrent re-openings.

A Chinese Traditional Therapy for Bleomycin-Induced Pulmonary Fibrosis in Mice

Pulmonary fibrosis is a chronic and fatal disease of lung tissue with high incidence and mortality in the world. The exploration of effective treatment for pulmonary fibrosis remains an urgent challenge. In our study, Qingfei Xieding was investigated as a novel Chinese traditional patent medicine against pulmonary fibrosis. A pulmonary fibrosis mouse model was constructed by injecting with bleomycin sulfate. Following Qingfei Xieding administration, lung samples were collected to assess pulmonary phenotype changes by analyzing lung coefficient, wet/dry, and histopathologic section. Levels of nitric oxide (NO), hydroxyproline (HYP), malondialdehyde (MDA), and total antioxidant capacity were measured to evaluate the degree of oxidation. A single-cell gel electrophoresis (SCGE) assay was used to evaluate bleomycin-induced DNA damage. Western blotting and real-time quantitative PCR were performed to determine the abundance of inducible nitric oxide synthase (iNOS), connective tissue growth factor (CTGF), alpha smooth muscle actin (α-SMA), and fibronectin (FN). In the present study, Qingfei Xieding administration significantly attenuated bleomycin-induced pulmonary fibrosis in mice by reducing lung coefficient, wet/dry, NO, HYP, and MDA as well as the expression of iNOS, CTGF, α-SMA, FN, and DNA damage. The results indicated that Qingfei Xieding is effective to resist oxidative damage and histopathologic lesion, serving a protection role on bleomycin-induced pulmonary fibrosis.

Inorganic Nitrate Mimics Exercise-Stimulated Muscular Fiber-Type Switching and Myokine and γ-Aminobutyric Acid Release

Exercise is an effective intervention for the prevention and treatment of type 2 diabetes. Skeletal muscle combines multiple signals that contribute to the beneficial effects of exercise on cardiometabolic health. Inorganic nitrate increases exercise efficiency, tolerance, and performance. The transcriptional regulator peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) coordinates the exercise-stimulated skeletal muscle fiber-type switch from glycolytic fast-twitch (type IIb) to oxidative slow-twitch (type I) and intermediate (type IIa) fibers, an effect reversed in insulin resistance and diabetes. We found that nitrate induces PGC1α expression and a switch toward type I and IIa fibers in rat muscle and myotubes in vitro. Nitrate induces the release of exercise/PGC1α-dependent myokine FNDC5/irisin and β-aminoisobutyric acid from myotubes and muscle in rats and humans. Both exercise and nitrate stimulated PGC1α-mediated γ-aminobutyric acid (GABA) secretion from muscle. Circulating GABA concentrations were increased in exercising mice and nitrate-treated rats and humans; thus, GABA may function as an exercise/PGC1α-mediated myokine-like small molecule. Moreover, nitrate increased circulating growth hormone levels in humans and rodents. Nitrate induces physiological responses that mimic exercise training and may underlie the beneficial effects of this metabolite on exercise and cardiometabolic health.

[Effect of a novel EZH2 inhibitor GSK126 on prostate cancer cells]

Objective: To investigate the effect of a novel EZH2 inhibitor GSK126 on cell growth, apoptosis and migration of prostate cancer cells. Methods: Prostate cancer PC-3 and DU145 cells were treated with GSK126 at different doses. Cell growth was detected by sulforhodamine assay. Cell apoptosis was assayed by Annexin V-/PI kit. Transwell chamber and wound healing assays were conducted to detect cell migration. The mRNA level was detected by quantitative PCR, and protein expression was detected by Western blot analysis. Results: GSK126 showed significant effect on cell growth and apoptosis when the dose was higher than 50 μmol/L. Wound healing assay revealed that scratch space in PC-3 cells was significantly increased in a dose-dependent manner in GSK126-treated groups[(247.2±24.4),(347.2±19.2) and (410.5±18.1) μm in low, medium and high dose (5.0, 20.0, 50.0 μmol/L), respectively] as compared with the control group[(171.3±17.8) μm](all P<0.05). Transwell assay showed that migrated PC-3 cells in control group was 322.0±17.9,while those in GSK126-treated groups were 198.3±15.4 (low),82.7±6.2 (medium) and 30.2±4.1 (high), and the differences between the control group and GSK126-treated groups were significant(all P<0.05). In addition, GSK126 up-regulated E-cadherin mRNA expression and down-regulated N-cadherin and Vimentin mRNA expression, whereas had no significant effect on Snail, Fibronectin and VEGF-A mRNA expression. The protein expression of E-cadherin was elevated but VEGF-A protein did not change in GSK126-treated groups. Similar results were exhibited in DU145 cell. Conclusion: GSK126 can significantly inhibit cell migration and invasion in prostate cancer PC-3 and DU145 cells, which may be resulted from its effect on epithelial-mesenchymal transition. GSK126 may be used as a potential anti-prostate cancer dug in clinic.

Jararhagin disruption of endothelial cell anchorage is enhanced in collagen enriched matrices

Hemorrhage is one of the most striking effects of bites by viper snakes resulting in fast bleeding and ischemia in affected tissues. Snake venom metalloproteinases (SVMPs) are responsible for hemorrhagic activity, but the mechanisms involved in SVMP-induced hemorrhage are not entirely understood and the study of such mechanisms greatly depends on in vivo experiments. In vivo, hemorrhagic SVMPs accumulate on basement membrane (BM) of venules and capillary vessels allowing the hydrolysis of collagen IV with consequent weakness and rupture of capillary walls. These effects are not reproducible in vitro with conventional endothelial cell cultures. In this study we used two-dimension (2D) or three-dimension (3D) cultures of HUVECs on matrigel and observed the same characteristics as in ex vivo experiments: only the hemorrhagic toxin was able to localize on surfaces or internalize endothelial cells in 2D cultures or in the surface of tubules formed on 3D cultures. The contribution of matrigel, fibronectin and collagen matrices in jararhagin-induced endothelial cell damage was then analyzed. Collagen and matrigel substrates enhanced the endothelial cell damage induced by jararhagin allowing toxin binding to focal adhesions, disruption of stress fibers, detachment and apoptosis. The higher affinity of jararhagin to collagen than to fibronectin explains the localization of the toxin within BM. Moreover, once located in BM, interactions of jararhagin with α2β1 integrin would favor its localization on focal adhesions, as observed in our study. The accumulation of toxin in focal adhesions, observed only in cells grown in collagen matrices, would explain the enhancement of cell damage in these matrices and reflects the actual interaction among toxin, endothelial cells and BM components that occurs in vivo and results in the hemorrhagic lesions induced by viper venoms.

[Clinical evaluation of ocriplasmin as a vitreolytic agent]

Incomplete perifoveal posterior vitreous detachment (PVD) associated with abnormal vitreomacular adhesion (VMA) can cause vitreomacular traction (VMT) and macular hole (MH) formation, which require vitrectomy treatment. Pharmacologic vitreolysis, which is intravitreal injection with vitreolytic enzymes to resolve VMA, may be used as an alternative therapy.Ocriplasmin, formerly known as microplasmin, is a recombinant truncated form of plasmin with proteolytic activity against fibronectin and laminin.It was recently approved for VMA treatment in the European Union and USA. Phase III studies indicated that ocriplasmin injection was a safe and effective treatment for selected cases of symptomatic VMA and MH. VMA release was achieved in 26.5% of ocriplasmin-injected eyes versus 10.1% of the placebo group. MH closure was achieved in 40.6% as compared with 10.6% of the placebo group.In comparison with the outcome after vitrectomy, the success rate of ocriplasmin was still far below expectation. Ocular adverse events included vitreous floaters, photopsia and profound visual decline. Its efficacy and safety need to be further evaluated in more clinical trials.

Chronic nicotine exposure stimulates biliary growth and fibrosis in normal rats

BACKGROUND

Epidemiological studies have indicated smoking to be a risk factor for the progression of liver diseases. Nicotine is the chief addictive substance in cigarette smoke and has powerful biological properties throughout the body. Nicotine has been implicated in a number of disease processes, including increased cell proliferation and fibrosis in several organ systems.

AIMS

The aim of this study was to evaluate the effects of chronic administration of nicotine on biliary proliferation and fibrosis in normal rats.

METHODS

In vivo, rats were treated with nicotine by osmotic minipumps for two weeks. Proliferation, α7-nicotinic receptor and profibrotic expression were evaluated in liver tissue, cholangiocytes and a polarized cholangiocyte cell line (normal rat intrahepatic cholangiocyte). Nicotine-dependent activation of the Ca(2+)/IP3/ERK 1/2 intracellular signalling pathway was also evaluated in normal rat intrahepatic cholangiocyte.

RESULTS

Cholangiocytes express α7-nicotinic receptor. Chronic administration of nicotine to normal rats stimulated biliary proliferation and profibrotic gene and protein expression such as alpha-smooth muscle actin and fibronectin 1. Activation of α7-nicotinic receptor stimulated Ca(2+)/ERK1/2-dependent cholangiocyte proliferation.

CONCLUSION

Chronic exposure to nicotine contributes to biliary fibrosis by activation of cholangiocyte proliferation and expression of profibrotic genes. Modulation of α7-nicotinic receptor signalling axis may be useful for the management of biliary proliferation and fibrosis during cholangiopathies.

Effects of Antibiotics onPseudomonas aeruginosaNK125502 andPseudomonas fluorescensMF0 Biofilm Formation on Immobilized Fibronectin

The effect of subminimal inhibitory concentration (1/2 MIC) of antibiotics on the biofilm formation on immobilized fibronectin by Pseudomonas was investigated by examining the reference strains NK125502 P. aeruginosa and MF0 P. fluorescens in a microtiter plates assay. When the antibiotics were added during bacterial growth and biofilm development, gentamicin was the only antimicrobial agent tested which decreased significantly the biofilm formation by the two strains. Cefsulodin and chloramphenicol also decreased the P. aeruginosa biofilm development (P<0.01), whereas polymyxin B inhibited biofilm formation by P. fluorescens (p<0.05). When the antibiotics were only present during bacterial growth and not during biofilm development, gentamicin was the only antibiotic tested to decrease significantly the biofilm formation by P. aeruginosa for incubation times of 20 and 72h (P<0.01), whereas P. fluorescens was not affected. This persistent inhibition of P. aeruginosa biofilm formation may be interesting in intermittent antibiotherapy treatments.

Estradiol promotes the development of a fibrotic phenotype and is increased in the serum of patients with systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is more prevalent in women. Our goal is to determine the effects of 17β-estradiol (E2) on the development of fibrosis and to compare circulating levels of estrogens in SSc patients and healthy controls.

METHODS

Using primary human dermal fibroblasts, we evaluated the effect of E2 on fibronectin (FN) expression with and without the estrogen receptor (ER) antagonist ICI 182,780, inhibitors of signaling, propyl-pyrazole-triol, an ERα specific ligand, and genistein, an ERβ selective ligand, to identify the signaling pathways mediating E2's effect. We confirmed the fibrotic effect of E2 in human skin using an ex vivo organ culture model. Lastly, we measured levels of E2 and estrone in serum samples from SSc patients with diffuse cutaneous involvement and healthy controls using mass spectrometry.

RESULTS

E2 increased expression of FN in dermal fibroblasts. ICI 182,780, inositol-1,4,5-triphosphate inhibitor, and p38 mitogen-activated protein kinase inhibitor blocked the effects of E2 on FN. Propyl-pyrazole-triol, but not genistein, significantly increased FN expression. Ex vivo, E2 induced fibrosis of human skin. The effects of E2 were abrogated by ICI 182,780. Circulating levels of E2 and estrone were significantly increased in sera of patients with diffuse cutaneous SSc.

CONCLUSION

Our findings implicate estrogens in the fibrotic process and may explain the preponderance of SSc in women. ICI 182,780 or other ER signaling antagonists may be effective agents for the treatment of fibrosis.

Inhibition of Substrate-Tumor Cell Adhesion Under the Effect of Gnidilatimonoein Purified fromDaphne mucronata

Alteration of the cell surface glycoproteins of cancerous cells correlate with malignancy potential. To evaluate the mediation of membrane glycoproteins in wehi-164 cancerous cells, under the effect of D. mucronata crude extract and one of its purified active components, gnidilatimonoein, their attachment to fibronectin-coated wells were investigated. The plant extract, 27 μl/ml (equivalent to 0.54 mg/of plant leaves powder per ml of culture medium), as well as gnidilatimonoein (0.94 μM), were capable of quenching by 58% and 64%, respectively, the attachment of wehi-164 cells to fibronectin-coated wells (4 μg/ml). In addition to alteration of cell adhesive properties, the morphology of the treated cells were significantly changed upon treatment with the non-toxic dose of the plant extract or gnidilatimonoein. While the untreated cells have polygonal shapes, the treated cells had spherical shapes.

Immunolocalization of fibronectin during reparative dentinogenesis in rat molor teeth after pulp capping with mineral trioxide aggregate or calcium hydroxide

The aim of this study was to evaluate the immunolocalization of fibronectin during reparative dentinogenesis in rat teeth after pulp capping with mineral trioxide aggregate (MTA) or calcium hydroxide (Ca(OH)2). The pulps of 72 upper and lower first molar teeth from 18 male Wistar rats were experimentally exposed. The pulps were capped with MTA or (Ca(OH)2); final restoration followed with zinc oxide and eugenol cement. The animals were euthanized at, respectively, one, three, seven and fourteen days postoperatively. At day one, all groups showed varying degrees of inflammation, from mild to severe. There was no positive reaction for fibronectin at day one. After three days, a partial acute pulpitis was observed in the Ca(OH)2 group. There was less inflammation in the MTA group (p<0.05), and a layer of fibrin barrier was observed along the pulp walls of the MTA material. The layer of fibrodentin formation showed positive reaction for fibronectin. At seven days, the Ca(OH)2 group showed mild inflammation and demonstrated more immunostaining for fibronectin than the Ca(OH)2 group (p<0.05) at three days. Pulps capped with MTA at seven days showed thicker fibrin barrier formation than the MTA group at three days and more immunostaining for fibronectin in whole groups (p<0.05). At fourteen days, there was no positive reaction for fibronectin in either the MTA or Ca(OH)2 group. It seems MTA showed better biocompability properties with the dental pulp tissue, inducing the expression of reparative molecule fibronectin compared with Ca(OH)2. Therefore, MTA may be a better choice for pulp capping procedures.

Influence of 3-hydroxymethyl xylitol, a novel antidiabetic compound isolated from Casearia esculenta (Roxb.) root, on glycoprotein components in streptozotocin-diabetic rats

Casearia esculenta root (Roxb.) is widely used in traditional system of medicine to treat diabetes in India. An active compound, 3-hydroxymethyl xylitol (3-HMX), has been isolated, and its optimum dose has been determined in a short duration study and patented. In addition, the long-term effect of 3-HMX in type 2 diabetic rats on antihyperglycemic, antioxidants, antihyperlipidemic, and protein metabolism and kidney marker enzymes was investigated, and its effect was shown previously. In this study, we investigated the effect of 3-HMX on plasma and tissue glycoproteins in streptozotocin-diabetic rats. Animals were divided into five groups viz., control group, 3-HMX (40 mg/kg of body weight) treated group, diabetic group, diabetic+3-HMX (40 mg/kg of body weight), and diabetic+glibenclamide (600 μg/kg of body weight). 3-HMX was administered orally at a dose of 40 mg/kg of body weight for 45 days. The study shows significant increases in the level of sialic acid except kidney and elevated levels of hexose, hexosamine, and fucose in the liver and kidney of diabetic rats, and the treatment with 3-HMX and glibenclamide showed reversal of these parameters toward normalcy. Thus, the study indicates that 3-HMX possesses a significant beneficial effect on glycoprotein components.

Long-term treatment with Hachimi-jio-gan attenuates kidney damage in spontaneously diabetic WBN/Kob rats

Diabetes mellitus is now the most common cause of end-stage renal failure. In this study, the effects of Hachimi-jio-gan on diabetic kidney damage in spontaneously diabetic WBN/Kob rats were examined. Oral administration of Hachimi-jio-gan to WBN/Kob rats for 25 weeks significantly suppressed urinary protein excretion. It did not affect body weight loss or blood glucose levels, whereas it reversed the increase in kidney weight of WBN/Kob rats. Hachimi-jio-gan also reduced fibronectin and transforming growth factor β1 (TGF-β1) protein expression in the renal cortex. Furthermore, renal lipid peroxidation levels of WBN/Kob rats given Hachimi-jio-gan were significantly lower than those of untreated controls. Renal superoxide dismutase activity was elevated by Hachimi-jio-gan treatment in a dose-dependent manner. These results suggested that Hachimi-jio-gan could prevent diabetic kidney damage by reducing renal oxidative injury and expression of fibronectin and TGF-β1 proteins, which are all involved in the pathophysiology of diabetic nephropathy.

Mycophenolic acid inhibits oleic acid-induced mesangial cell activation through both cellular reactive oxygen species and inosine monophosphate dehydrogenase 2 pathways

The synthesis of extracellular matrix (ECM) in mesangial cells (MCs) plays important roles in the development and progression of renal diseases, including chronic allograft nephropathy. Mycophenolic acid (MPA), an inhibitor of inosine monophosphate dehydrogenase 2 (IMPDH2), suppresses MC proliferation and ECM synthesis. However, the exact inhibitory mechanism of MPA on MCs has not been clearly elucidated. In this study we compared the inhibitory effects of MPA and IMPDH2 reduction [by using small interfering RNA (siRNA)] on oleic acid (OA)-induced fibronectin secretion and cellular reactive oxygen species (ROS) in mouse MCs. Growth-arrested MCs were stimulated with OA in the presence or absence of MPA, IMPDH2 siRNA, N-acetylcysteine (NAC), transforming growth factor beta (TGF-beta) antibody or exogenous guanosine. Fibronectin secretion into the medium was examined by Western blot, dichlorodihydrofluorescein (DCF)-sensitive cellular ROS by fluorescence-activated cell scanning (FACS), TGF-beta levels in the media by enzyme-linked immunosorbent assay (ELISA). OA increased fibronectin secretion, TGF-beta and cellular ROS levels. A TGF-beta neutralizing antibody effectively suppressed OA-induced fibronectin secretion. NAC and MPA completely suppressed OA-induced fibronectin secretion and decreased the levels of TGF-beta and cellular ROS. However, IMPDH2 siRNA partly inhibited OA-induced MC activation. Exogenous guanosine successfully reversed the inhibitory effects of IMPDH2 siRNA on OA-induced MC activation. Pleiotropic inhibitory effect of MPA on OA-induced mouse MC activation was mediated via its antioxidant effect on cellular ROS production and partly via inhibition of IMPDH2 itself. Our results implicate ROS as an alternative therapeutic target for the prevention of hyperlipidemia-related glomerulopathy, chronic allograft nephropathy, and subsequent graft loss.

Sortase inhibitor phenyl vinyl sulfone inhibits Renibacterium salmoninarum adherence and invasion of host cells

Renibacterium salmoninarum, the causative agent of bacterial kidney disease in salmonid fishes, is a Gram-positive diplococcobacillus belonging to the family Micrococcaceae. Analysis of the genome sequence of the bacterium demonstrated the presence of a sortase homolog (srtD), a gene specifying an enzyme found in Gram-positive bacteria and required for covalent anchoring of cell surface proteins. Interference of sortase activity is being examined as a target for therapeutic prevention of infection by several pathogenic Gram-positive bacterial species. In silico analysis identified 8 open reading frames containing sortase recognition motifs, suggesting these proteins are translocated to the bacterial cell wall. The sortase and potential sortase substrate genes are transcribed in R. salmoninarum, suggesting they encode functional proteins. Treatment of R. salmoninarum with phenyl vinyl sulfone (PVS) significantly reduced bacterial adherence to Chinook salmon fibronectin. In addition, the ability of the PVS-treated bacteria to adhere to Chinook salmon embryo cells (CHSE-214) in vitro was dramatically reduced compared to that of untreated bacteria. More importantly, PVS-treated bacteria were unable to invade and replicate within CHSE-214 cells (demonstrated by an intracellular growth assay and by light microscopy). When treated with PVS, R. salmoninarum was not cytopathic to CHSE-214 cells, whereas untreated bacteria produced cytopathology within a few days. These findings clearly show that PVS, a small molecule drug and a known sortase inhibitor, can interfere with the ability of R. salmoninarum to adhere and colonize fish cells, with a corresponding decrease in virulence.

The lipoxygenase inhibitor, baicalein, modulates cell adhesion and migration by up-regulation of integrins and vinculin in rat heart endothelial cells

BACKGROUND AND PURPOSE

Endothelial cell proliferation, migration and adhesion are necessary for the formation of new blood vessels. We reported previously that baicalein strongly inhibited proliferation of rat heart endothelial cells and here we assess effects on migration and adhesion of these cells.

EXPERIMENTAL APPROACH

Effects of baicalein on endothelial migration and adhesion were determined by in vitro wound assays and in modified Boyden chambers. Protein expression and subcellular distribution in rat heart endothelial cells were analysed by immunoblots and immunofluorescence staining.

RESULTS

Pretreatment with baicalein for 48 h resulted in a concentration-dependent inhibition of endothelial migration, with an IC(50) of approximately 20 microM. Adhesion assays revealed that baicalein stimulated endothelial cell adhesion to fibronectin and vitronectin, effects blocked by the synthetic peptide Arg-Gly-Asp (RGD). Moreover, treatment with a blocking antibody against integrin alpha5beta1 drastically attenuated baicalein-mediated endothelial adhesion to fibronectin, but not to vitronectin. Furthermore, baicalein-mediated anti-migration effect and adhesion promotion could be partially reversed by the addition of 12(S)-hydroxyeicosatetraenoic acid (12(S)-HETE). Western blot analysis indicated that baicalein increased expression levels of integrin-alpha5beta1, -alphavbeta3 and vinculin proteins. Immunofluorescence staining showed that baicalein induced a marked reorganization of actin stress fibres and the recruitment of vinculin and integrins to focal adhesion plaques, with consequently increased formation of focal adhesion contacts.

CONCLUSIONS AND IMPLICATIONS

Baicalein markedly inhibited the migration and enhanced the adhesion of rat heart endothelial cells, possibly by up-regulation of the integrins (alpha5beta1 and alphavbeta3) and vinculin and by promotion of actin reorganization and focal adhesion contact formation.

Periostin creates a tumor-supportive microenvironment in the pancreas by sustaining fibrogenic stellate cell activity

BACKGROUND & AIMS

Pancreatic cancer creates desmoplasia by stimulating stellate cells (PSCs), thereby influencing tumor aggressiveness. The aim of this study was to analyze the impact of the PSC-specific matrix protein periostin on tumor responses to radiochemotherapy.

METHODS

PSCs and cancer cells in primary and metastatic lesions of patients treated with or without neoadjuvant radiochemotherapy were evaluated by immunohistochemistry. Periostin messenger-RNA levels determined by quantitative reverse-transcription polymerase chain reaction were correlated to patient survival. Interactions between PSCs and cancer cells and the effects of periostin in modulating cellular responses under conditions of hypoxia, starvation, and radiochemotherapy were assessed by immunoblotting and by growth, clonogenicity, and invasion assays.

RESULTS

Periostin messenger-RNA levels were elevated 42-fold in cancer, and patients with increased expression had a tendency toward shorter survival (19 vs 12 months; P = .14). Stromal cells were the only source of periostin in the pancreas and in metastatic sites. Cancer cell supernatants stimulated periostin secretion from PSCs. Recombinant periostin increased alpha-smooth muscle actin, periostin, collagen-1, fibronectin, and transforming growth factor-beta1 expression while decreasing PSC invasiveness. These effects were reversed by silencing periostin expression and secretion by small interfering RNA transfection. In cancer cells, periostin stimulated growth and conferred resistance to starvation and hypoxia. In addition, the periostin downstream target collagen-1 significantly increased chemoresistance.

CONCLUSIONS

Once stimulated by cancer cells, PSCs remain active via an autocrine periostin loop even under radiotherapy and produce excessive extracellular matrix proteins, creating a tumor-supportive microenvironment. Increased periostin expression may therefore reflect a more aggressive tumor phenotype.

Protective effects of keishibukuryogan on the kidney of spontaneously diabetic WBN/Kob rats

Keishibukuryogan, one of the traditional herbal formulations, is used clinically to improve blood circulation. It consists of the following five crude drugs: Cinnamomi Cortex, Poria, Moutan Cortex, Persicae Semen and Paeoniae Radix. In this study, the effects of keishibukuryogan against renal damage in spontaneously diabetic WBN/Kob rats were examined. Oral administration of keishibukuryogan significantly attenuated urinary protein excretion and serum creatinine levels. It did not affect body weight loss and blood glucose levels, but it suppressed renal and hepatic weights of WBN/Kob rats. Keishibukuryogan also reduced fibronectin and transforming growth factor beta(1) (TGF-beta(1)) protein expression in the renal cortex. Furthermore, lipid peroxidation levels in both kidney and liver were significantly lower than those of untreated control WBN/Kob rats. Urinary excretion of 8-hydroxy-deoxyguanosine was suppressed by keishibukuryogan treatment. These results suggest that keishibukuryogan reduces oxidative stress by hyperglycemia, and that it protects renal function and suppresses fibronectin deposition induced by TGF-beta(1) production in WBN/Kob rats.

Role of connective tissue growth factor (CTGF) module 4 in regulating epithelial mesenchymal transition (EMT) in HK-2 cells

BACKGROUND

Recent studies have suggested that connective tissue growth factor (CTGF) plays a key role in tissue fibrosis including renal scarring. While studies showed several forms of CTGF with 10-38 kDa in the body fluids, little is known about these small molecule species. We investigated the effect of a 10 kDa CTGF molecule consisting of module 4, on the epithelial mesenchymal transition (EMT) in human proximal tubular cell line (HK-2).

METHODS

HK2 cells were cultured in DMEM medium. The response of cytokeratin (CK) and vimentin (VIM) mRNA and protein expression to the stimulation of rhCTGF(C) were observed by real-time PCR and immunocytochemistry. At the same time, the morphologic changes were observed by microscopy, and expression of alpha-smooth muscle actin (alpha-SMA) and fibronectin (FN) was detected by laser confocal microscope. These effects were compared with CTGF N-terminal [rhCTGF(N)], consisting of module 1-3, and observed in a condition with the addition of anti-CTGF antibody.

RESULTS

RhCTGF(C) induced striking changes in epithelial cells, including changes in cellular morphology, loss of CK, gain VIM and alpha-SMA, and increased levels of fibronectin. Cocultured with anti-CTGF antibody could abrogate most of these effects, while cells treated with rhCTGF(N) showed no significant phenotypic changes comparing to control group.

CONCLUSIONS

Our results suggest that module 4 could induce HK-2 cells EMT, whereas the residual fragment has no similar effect in spite of consisting of 3 modules of CTGF molecule.

Degradation of extracellular matrix proteins (fibronectin, vitronectin and laminin) by serine-proteinases isolated from Lonomia achelous caterpillar hemolymph

Lonomia achelous is a caterpillar distributed in southern Venezuela and in northern Brazil that causes an acute hemorrhagic syndrome in people who have contact with its bristles. The effect of the crude hemolymph and its chromatographic fractions (FDII, Lonomin V and Lonomin V-2) on extracellular matrix proteins was studied. The chromatographic fractions show activities similar to plasmin and urokinase. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis, both lonomins appear as a protein band of 25 kDa under reduced conditions. By exclusion chromatography, the molecular weights of Lonomin V and Lonomin V-2 were 26.5 and 24.5 kDa, respectively. Fibronectin, laminin and vitronectin were degraded by all venom components. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, under reduced conditions, shows that lonomins degrade fibronectin in four main fragments of 116, 60, 50 and 30 kDa. Molecular exclusion chromatography in native conditions shows that the molecular masses of these fragments are > or = 300, 62 and 27 kDa. The proteolytic effect of lonomins was abolished by benzamidine/HCl, iodoacetic acid and aprotinin. The extracellular matrix protein degradation together with the fibrino(geno)lytic activity of hemolymph and its fractions could explain, in part, the hemorrhagic syndrome, and the wound dehiscence in persons who have had contact with the L. achelous caterpillar.