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Sample records for stellate cells blocks

  1. Stellate ganglion block for persistent idiopathic facial pain

    Poonam Patel

    2016-01-01

    Full Text Available Persistent idiopathic facial pain is a facial pain disorder without any identifiable cause. A patient has persistent facial pain without any objective sign on clinical examination or investigations. There are associated psychological problems such as depression and anxiety. This condition is poorly responsive to therapy with anticonvulsants or analgesics. Stellate ganglion block interrupts the sympathetic supply to head, neck, and upper extremities. This block can be used to alleviate pain of sympathetic origin in head and neck region as well as upper extremities. We report a case of a middle-aged female with persistent idiopathic facial pain on the right side of face with no response to analgesics and anticonvulsants. Her pain was provoked by exposure to cold weather or wind. Assuming a sympathetic component to her pain, we did a right-sided stellate ganglion block for her with local anesthetic and steroid. The patient had significant pain relief (>80% after the block. This indicates that the sympathetic nervous system plays a major role in initiation and perpetuation of this pain condition. Stellate ganglion block can be done early in such patients both as a diagnostic and therapeutic modality.

  2. Interaction of Stellate Cells with Pancreatic Carcinoma Cells

    Marco Siech

    2010-09-01

    Full Text Available Pancreatic cancer is characterized by its late detection, aggressive growth, intense infiltration into adjacent tissue, early metastasis, resistance to chemo- and radiotherapy and a strong “desmoplastic reaction”. The dense stroma surrounding carcinoma cells is composed of fibroblasts, activated stellate cells (myofibroblast-like cells, various inflammatory cells, proliferating vascular structures, collagens and fibronectin. In particular the cellular components of the stroma produce the tumor microenvironment, which plays a critical role in tumor growth, invasion, spreading, metastasis, angiogenesis, inhibition of anoikis, and chemoresistance. Fibroblasts, myofibroblasts and activated stellate cells produce the extracellular matrix components and are thought to interact actively with tumor cells, thereby promoting cancer progression. In this review, we discuss our current understanding of the role of pancreatic stellate cells (PSC in the desmoplastic response of pancreas cancer and the effects of PSC on tumor progression, metastasis and drug resistance. Finally we present some novel ideas for tumor therapy by interfering with the cancer cell-host interaction.

  3. Epigenetic Changes during Hepatic Stellate Cell Activation.

    Silke Götze

    Full Text Available Hepatic stellate cells (HSC, which can participate in liver regeneration and fibrogenesis, have recently been identified as liver-resident mesenchymal stem cells. During their activation HSC adopt a myofibroblast-like phenotype accompanied by profound changes in the gene expression profile. DNA methylation changes at single genes have been reported during HSC activation and may participate in the regulation of this process, but comprehensive DNA methylation analyses are still missing. The aim of the present study was to elucidate the role of DNA methylation during in vitro activation of HSC.The analysis of DNA methylation changes by antibody-based assays revealed a strong decrease in the global DNA methylation level during culture-induced activation of HSC. To identify genes which may be regulated by DNA methylation, we performed a genome-wide Methyl-MiniSeq EpiQuest sequencing comparing quiescent and early culture-activated HSC. Approximately 400 differentially methylated regions with a methylation change of at least 20% were identified, showing either hypo- or hypermethylation during activation. Further analysis of selected genes for DNA methylation and expression were performed revealing a good correlation between DNA methylation changes and gene expression. Furthermore, global DNA demethylation during HSC activation was investigated by 5-bromo-2-deoxyuridine assay and L-mimosine treatment showing that demethylation was independent of DNA synthesis and thereby excluding a passive DNA demethylation mechanism.In summary, in vitro activation of HSC initiated strong DNA methylation changes, which were associated with gene regulation. These results indicate that epigenetic mechanisms are important for the control of early HSC activation. Furthermore, the data show that global DNA demethylation during activation is based on an active DNA demethylation mechanism.

  4. Therapeutic potential of stellate ganglion block in orofacial pain: a mini review.

    Jeon, Younghoon

    2016-09-01

    Orofacial pain is a common complaint of patients that causes distress and compromises the quality of life. It has many etiologies including trauma, interventional procedures, nerve injury, varicella-zoster (shingles), tumor, and vascular and idiopathic factors. It has been demonstrated that the sympathetic nervous system is usually involved in various orofacial pain disorders such as postherpetic neuralgia, complex regional pain syndromes, and atypical facial pain. The stellate sympathetic ganglion innervates the head, neck, and upper extremity. In this review article, the effect of stellate ganglion block and its mechanism of action in orofacial pain disorders are discussed.

  5. Apamin suppresses biliary fibrosis and activation of hepatic stellate cells.

    Kim, Jung-Yeon; An, Hyun-Jin; Kim, Woon-Hae; Park, Yoon-Yub; Park, Kyung Duck; Park, Kwan-Kyu

    2017-05-01

    Cholestatic liver disease is characterized by the progressive destruction of biliary epithelial cells (BECs) followed by fibrosis, cirrhosis and liver failure. Activated hepatic stellate cells (HSCs) and portal fibroblasts are the major cellular effectors of enhanced collagen deposition in biliary fibrosis. Apamin, an 18 amino acid peptide neurotoxin found in apitoxin (bee venom), is known to block Ca2+-activated K+ channels and prevent carbon tetrachloride-induced liver fibrosis. In the present study, we aimed to ascertain whether apamin inhibits biliary fibrosis and the proliferation of HSCs. Cholestatic liver fibrosis was established in mouse models with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) feeding. Cellular assays were performed on HSC-T6 cells (rat immortalized HSCs). DDC feeding led to increased hepatic damage and proinflammtory cytokine levels. Notably, apamin treatment resulted in decreased liver injury and proinflammatory cytokine levels. Moreover, apamin suppressed the deposition of collagen, proliferation of BECs and expression of fibrogenic genes in the DDC-fed mice. In HSCs, apamin suppressed activation of HSCs by inhibiting the Smad signaling pathway. These data suggest that apamin may be a potential therapeutic target in cholestatic liver disease.

  6. Modulation of hepatic stellate cells and reversibility of hepatic fibrosis

    Huang, Yu, E-mail: 1293363632@QQ.com [Faculty of Graduate Studies of Guangxi University of Chinese Medicine, Nanning 530001, Guangxi Zhuang Autonomous Region (China); Deng, Xin, E-mail: Hendly@163.com [Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, 10 East China Road, Nanning 530011, Guangxi Zhuang Autonomous Region (China); Liang, Jian, E-mail: lj99669@163.com [Guangxi University of Chinese Medicine, Nanning 530001, Guangxi Zhuang Autonomous Region (China)

    2017-03-15

    Hepatic fibrosis (HF) is the pathological component of a variety of chronic liver diseases. Hepatic stellate cells (HSC) are the main collagen-producing cells in the liver and their activation promotes HF. If HSC activation and proliferation can be inhibited, HF occurrence and development can theoretically be reduced and even reversed. Over the past ten years, a number of studies have addressed this process, and here we present a review of HSC modulation and HF reversal. - Highlights: • We present a review of the modulation of hepatic stellate cells (HSC) and reversibility of hepatic fibrosis (HF). • HSC are the foci of HF occurrence and development, HF could be prevented and treated by modulating HSC. • If HSC activation and proliferation can be inhibited, HF could theoretically be inhibited and even reversed. • Prevention or reversal of HSC activation, or promotion of HSC apoptosis, immune elimination, and senescence may prevent, inhibit or reverse HF.

  7. Effectiveness of Stellate Ganglion Block Under Fuoroscopy or Ultrasound Guidance in Upper Extremity CRPS.

    Imani, Farnad; Hemati, Karim; Rahimzadeh, Poupak; Kazemi, Mohamad Reza; Hejazian, Kokab

    2016-01-01

    Stellate Ganglion Block (SGB) is an effective technique which may be used to manage upper extremities pain due to Chronic Regional Pain Syndrome (CRPS), in this study we tried to evaluate the effectiveness of this procedure under two different guidance for management of this syndrome. The purpose of this study was to evaluate the effectiveness of ultrsound guide SGB by comparing it with the furoscopy guided SGB in upper extermities CRPS patients in reducing pain & dysfuction of the affected link. Fourteen patients with sympathetic CRPS in upper extremities in a randomized method with block randomization divided in two equal groups (with ultrasound or fluoroscopic guidance). First group was blocked under fluoroscopic guidance and second group blocked under ultrasound guidance. After correct positioning of the needle, a mixture of 5 ml bupivacaine 0.25% and 1 mL of triamcinolone was injected. These data represent no meaningful statistical difference between the two groups in terms of the number of pain attacks before the blocks, a borderline correlation between two groups one week and one month after the block and a significant statistical correlation between two groups three month after the block. These data represent no meaningful statistical difference between the patients of any group in terms of the pain intensity (from one week to six months after block), p-value = 0.61. These data represent a meaningful statistical difference among patients of any group and between the two groups in terms of the pain intensity (before the block until six months after block), p-values were 0.001, 0.031 respectively. According the above mentioned data, in comparison with fluoroscopic guidance, stellate ganglion block under ultrasound guidance is a safe and effective method with lower complication and better improvement in patient's disability indexes.

  8. Treatment of patients with painful blind eye using stellate ganglion block

    Tatiana Vaz Horta Xavier

    2016-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: management of pain in painful blind eyes is still a challenge. Corticosteroids and hypotensive agents, as well as evisceration and enucleation, are some of the strategies employed so far that are not always effective and, depending on the strategy, cause a deep emotional shock to the patient. Given these issues, the aim of this case report is to demonstrate a new and viable option for the management of such pain by treating the painful blind eye with the stellate ganglion block technique, a procedure that has never been described in the literature for this purpose. CASE REPORT: six patients with painful blind eye, all caused by glaucoma, were treated; in these patients, VAS (visual analogue scale for pain assessment, in which 0 is the absence of pain and 10 is the worst pain ever experienced ranged from 7 to 10. We opted for weekly sessions of stellate ganglion block with 4 mL of bupivacaine (0.5% without vasoconstrictor and clonidine 1 mcg/kg. Four patients had excellent results at VAS, ranging between 0 and 3, and two remained asymptomatic (VAS = 0, without the need for additional medication. The other two used gabapentin 300 mg every 12 h. CONCLUSION: currently, there are several therapeutic options for the treatment of painful blind eye, among which stand out the retrobulbar blocks with chlorpromazine, alcohol and phenol. However, an effective strategy with low rate of serious complications, which is non-mutilating and improves the quality of life of the patient, is essential. Then, stellate ganglion block arises as a demonstrably viable and promising option to meet this demand.

  9. PDGF-receptor beta-targeted adenovirus redirects gene transfer from hepatocytes to activated stellate cells

    Schoemaker, Marieke H.; Rots, Marianne G.; Beljaars, Leonie; Ypma, Arjen Y.; Jansen, Peter L. M.; Poelstra, Klaas; Moshage, Albert; Haisma, Hidde J.

    2008-01-01

    Chronic liver damage may lead to liver fibrosis. In this process, hepatic activated stellate cells are the key players. Thus, activated stellate cells are attractive targets for antifibrotic gene therapy. Recombinant, adenovirus is a promising vehicle for delivering therapeutic genes to liver cells.

  10. Revalidation of a modified and safe approach of stellate ganglion block

    Ashok Jadon

    2011-01-01

    Full Text Available Stellate ganglion block (SGB is very effective in management of chronic regional pain syndrome (CRPS-1. However, serious complication may occur due to accidental intravascular (intra-arterial injection of local anaesthetic agents. Abdi and others, has suggested a modified technique in which fluoroscopy-guided block is given at the junction of uncinate process and body of vertebra at C7 level. In this approach vascular structures remain away from the trajectory of needle and thus avoid accidental vascular injection. We have used this technique of SGB in nine patients who were treated for CRPS-I. The blocks were effective in all the patients all the time without any vascular or other serious complication.

  11. Inhibitory effect of tanshinone IIA on rat hepatic stellate cells.

    Ya-Wei Liu

    Full Text Available Anti-inflammation via inhibition of NF-κB pathways in hepatic stellate cells (HSCs is one therapeutic approach to hepatic fibrosis. Tanshinone IIA (C19H18O3, Tan IIA is a lipophilic diterpene isolated from Salvia miltiorrhiza Bunge, with reported anti-inflammatory activity. We tested whether Tan IIA could inhibit HSC activation.The cell line of rat hepatic stellate cells (HSC-T6 was stimulated with lipopolysaccharide (LPS (100 ng/ml. Cytotoxicity was assessed by MTT assay. HSC-T6 cells were pretreated with Tan IIA (1, 3 and 10 µM, then induced by LPS (100 ng/ml. NF-κB activity was evaluated by the luciferase reporter gene assay. Western blotting analysis was performed to measure NF-κB-p65, and phosphorylations of MAPKs (ERK, JNK, p38. Cell chemotaxis was assessed by both wound-healing assay and trans-well invasion assay. Quantitative real-time PCR was used to detect gene expression in HSC-T6 cells.All concentrations of drugs showed no cytotoxicity against HSC-T6 cells. LPS stimulated NF-κB luciferase activities, nuclear translocation of NF-κB-p65, and phosphorylations of ERK, JNK and p38, all of which were suppressed by Tan IIA. In addition, Tan IIA significantly inhibited LPS-induced HSCs chemotaxis, in both wound-healing and trans-well invasion assays. Moreover, Tan IIA attenuated LPS-induced mRNA expressions of CCL2, CCL3, CCL5, IL-1β, TNF-α, IL-6, ICAM-1, iNOS, and α-SMA in HSC-T6 cells.Our results demonstrated that Tan IIA decreased LPS-induced HSC activation.

  12. Cytokeratin-positive folliculo-stellate cells in chicken adenohypophysis.

    Nishimura, Shotaro; Yamashita, Miyu; Kaneko, Takane; Kawabata, Fuminori; Tabata, Shoji

    2017-11-01

    Folliculo-stellate (FS) cells are non-endocrine cells found in the adenohypophysis and are identified in many animals by the S100 protein marker. Although keratin is another FS marker in several animals, there is no information on localization of keratin in the avian adenohypophysis. In this study, localization of cytokeratin in chicken adenohypophyseal cells was investigated immunohistochemically. Basic cytokeratin (bCK)-positive cells were arranged radially in the cell cords with their cytoplasmic processes reaching the basal lamina. The cell bodies encircled a follicle in the center of the cell cord. Furthermore, the bCK-positive cells were also S100B-positive. Growth hormone, prolactin, adrenocorticotrophic hormone, and luteinizing hormone β-subunit did not co-localize with the bCK-positive cells. In addition, the bCK-positive cells had a laminin-positive area in their cytoplasm. Transmission electron microscopy observed agranular cells equipped with several microvilli that encircled a follicle. These results indicate that bCK-positive cells in the chicken adenohypophysis may be a predominant FS cell population and produce laminin. It is suggested that they function as sustentacular cells to sustain the adjacent endocrine cells and the structure of the cell cords in the chicken adenohypophysis. © 2017 Japanese Society of Animal Science.

  13. Liver X receptors balance lipid stores in hepatic stellate cells through Rab18, a retinoid responsive lipid droplet protein.

    O'Mahony, Fiona; Wroblewski, Kevin; O'Byrne, Sheila M; Jiang, Hongfeng; Clerkin, Kara; Benhammou, Jihane; Blaner, William S; Beaven, Simon W

    2015-08-01

    Liver X receptors (LXRs) are determinants of hepatic stellate cell (HSC) activation and liver fibrosis. Freshly isolated HSCs from Lxrαβ(-/-) mice have increased lipid droplet (LD) size, but the functional consequences of this are unknown. Our aim was to determine whether LXRs link cholesterol to retinoid storage in HSCs and how this impacts activation. Primary HSCs from Lxrαβ(-/-) and wild-type mice were profiled by gene array during in vitro activation. Lipid content was quantified by high-performance liquid chromatography and mass spectroscopy. Primary HSCs were treated with nuclear receptor ligands, transfected with small interfering RNA and plasmid constructs, and analyzed by immunocytochemistry. Lxrαβ(-/-) HSCs have increased cholesterol and retinyl esters. The retinoid increase drives intrinsic retinoic acid receptor signaling, and activation occurs more rapidly in Lxrαβ(-/-) HSCs. We identify Rab18 as a novel retinoic acid-responsive, LD-associated protein that helps mediate stellate cell activation. Rab18 mRNA, protein, and membrane insertion increase during activation. Both Rab18 guanosine triphosphatase activity and isoprenylation are required for stellate cell LD loss and induction of activation markers. These phenomena are accelerated in Lxrαβ(-/-) HSCs, where there is greater retinoic acid flux. Conversely, Rab18 knockdown retards LD loss in culture and blocks activation, just like the functional mutants. Rab18 is also induced with acute liver injury in vivo. Retinoid and cholesterol metabolism are linked in stellate cells by the LD-associated protein Rab18. Retinoid overload helps explain the profibrotic phenotype of Lxrαβ(-/-) mice, and we establish a pivotal role for Rab18 GTPase activity and membrane insertion in wild-type stellate cell activation. Interference with Rab18 may have significant therapeutic benefit in ameliorating liver fibrosis. © 2015 by the American Association for the Study of Liver Diseases.

  14. Liver X Receptors Balance Lipid Stores in Hepatic Stellate Cells via Rab18, a Retinoid Responsive Lipid Droplet Protein

    O’Mahony, Fiona; Wroblewski, Kevin; O’Byrne, Sheila M.; Jiang, Hongfeng; Clerkin, Kara; Benhammou, Jihane; Blaner, William S.; Beaven, Simon W.

    2014-01-01

    Liver X receptors (LXRs) are determinants of hepatic stellate cell (HSC) activation and liver fibrosis. Freshly isolated HSCs from Lxrαβ−/− mice have increased lipid droplet (LD) size but the functional consequences of this are unknown. Our aim was to determine whether LXRs link cholesterol to retinoid storage in HSCs and how this impacts activation. Primary HSCs from Lxrαβ−/− and wild-type (WT) mice were profiled by gene array during in vitro activation. Lipid content was quantified by HPLC and mass spectroscopy. Primary HSCs were treated with nuclear receptor ligands, transfected with siRNA and plasmid constructs, and analyzed by immunocytochemistry. Lxrαβ−/− HSCs have increased cholesterol and retinyl esters (CEs & REs). The retinoid increase drives intrinsic retinoic acid receptor (RAR) signaling and activation occurs more rapidly in Lxrαβ−/− HSCs. We identify Rab18 as a novel retinoic acid responsive, lipid droplet associated protein that helps mediate stellate cell activation. Rab18 mRNA, protein, and membrane insertion increase during activation. Both Rab18 GTPase activity and isoprenylation are required for stellate cell lipid droplet loss and induction of activation markers. These phenomena are accelerated in the Lxrαβ−/− HSCs, where there is greater retinoic acid flux. Conversely, Rab18 knockdown retards lipid droplet loss in culture and blocks activation, just like the functional mutants. Rab18 is also induced with acute liver injury in vivo. Conclusion Retinoid and cholesterol metabolism are linked in stellate cells by the LD associated protein, Rab18. Retinoid overload helps explain the pro-fibrotic phenotype of Lxrαβ−/− mice and we establish a pivotal role for Rab18 GTPase activity and membrane insertion in wild-type stellate cell activation. Interference with Rab18 may have significant therapeutic benefit in ameliorating liver fibrosis. PMID:25482505

  15. Exosomes Derived From Pancreatic Stellate Cells: MicroRNA Signature and Effects on Pancreatic Cancer Cells.

    Takikawa, Tetsuya; Masamune, Atsushi; Yoshida, Naoki; Hamada, Shin; Kogure, Takayuki; Shimosegawa, Tooru

    2017-01-01

    Pancreatic stellate cells (PSCs) interact with pancreatic cancer cells in the tumor microenvironment. Cell constituents including microRNAs may be exported from cells within membranous nanovesicles termed exosomes. Exosomes might play a pivotal role in intercellular communication. This study aimed to clarify the microRNA signature of PSC-derived exosomes and their effects on pancreatic cancer cells. Exosomes were prepared from the conditioned medium of immortalized human PSCs. MicroRNAs were prepared from the exosomes and their source PSCs, and the microRNA expression profiles were compared by microarray. The effects of PSC-derived exosomes on proliferation, migration, and the mRNA expression profiles were examined in pancreatic cancer cells. Pancreatic stellate cell-derived exosomes contained a variety of microRNAs including miR-21-5p. Several microRNAs such as miR-451a were enriched in exosomes compared to their source PSCs. Pancreatic stellate cell-derived exosomes stimulated the proliferation, migration and expression of mRNAs for chemokine (C - X - C motif) ligands 1 and 2 in pancreatic cancer cells. The stimulation of proliferation, migration, and chemokine gene expression by the conditioned medium of PSCs was suppressed by GW4869, an exosome inhibitor. We clarified the microRNA expression profile in PSC-derived exosomes. Pancreatic stellate cell-derived exosomes might play a role in the interactions between PSCs and pancreatic cancer cells.

  16. Hypoxic stellate cells of pancreatic cancer stroma regulate extracellular matrix fiber organization and cancer cell motility.

    Sada, Masafumi; Ohuchida, Kenoki; Horioka, Kohei; Okumura, Takashi; Moriyama, Taiki; Miyasaka, Yoshihiro; Ohtsuka, Takao; Mizumoto, Kazuhiro; Oda, Yoshinao; Nakamura, Masafumi

    2016-03-28

    Desmoplasia and hypoxia in pancreatic cancer mutually affect each other and create a tumor-supportive microenvironment. Here, we show that microenvironment remodeling by hypoxic pancreatic stellate cells (PSCs) promotes cancer cell motility through alteration of extracellular matrix (ECM) fiber architecture. Three-dimensional (3-D) matrices derived from PSCs under hypoxia exhibited highly organized parallel-patterned matrix fibers compared with 3-D matrices derived from PSCs under normoxia, and promoted cancer cell motility by inducing directional migration of cancer cells due to the parallel fiber architecture. Microarray analysis revealed that procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) in PSCs was the gene that potentially regulates ECM fiber architecture under hypoxia. Stromal PLOD2 expression in surgical specimens of pancreatic cancer was confirmed by immunohistochemistry. RNA interference-mediated knockdown of PLOD2 in PSCs blocked parallel fiber architecture of 3-D matrices, leading to decreased directional migration of cancer cells within the matrices. In conclusion, these findings indicate that hypoxia-induced PLOD2 expression in PSCs creates a permissive microenvironment for migration of cancer cells through architectural regulation of stromal ECM in pancreatic cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  17. TLR9 ligation in pancreatic stellate cells promotes tumorigenesis.

    Zambirinis, Constantinos P; Levie, Elliot; Nguy, Susanna; Avanzi, Antonina; Barilla, Rocky; Xu, Yijie; Seifert, Lena; Daley, Donnele; Greco, Stephanie H; Deutsch, Michael; Jonnadula, Saikiran; Torres-Hernandez, Alejandro; Tippens, Daniel; Pushalkar, Smruti; Eisenthal, Andrew; Saxena, Deepak; Ahn, Jiyoung; Hajdu, Cristina; Engle, Dannielle D; Tuveson, David; Miller, George

    2015-11-16

    Modulation of Toll-like receptor (TLR) signaling can have protective or protumorigenic effects on oncogenesis depending on the cancer subtype and on specific inflammatory elements within the tumor milieu. We found that TLR9 is widely expressed early during the course of pancreatic transformation and that TLR9 ligands are ubiquitous within the tumor microenvironment. TLR9 ligation markedly accelerates oncogenesis, whereas TLR9 deletion is protective. We show that TLR9 activation has distinct effects on the epithelial, inflammatory, and fibrogenic cellular subsets in pancreatic carcinoma and plays a central role in cross talk between these compartments. Specifically, TLR9 activation can induce proinflammatory signaling in transformed epithelial cells, but does not elicit oncogene expression or cancer cell proliferation. Conversely, TLR9 ligation induces pancreatic stellate cells (PSCs) to become fibrogenic and secrete chemokines that promote epithelial cell proliferation. TLR9-activated PSCs mediate their protumorigenic effects on the epithelial compartment via CCL11. Additionally, TLR9 has immune-suppressive effects in the tumor microenvironment (TME) via induction of regulatory T cell recruitment and myeloid-derived suppressor cell proliferation. Collectively, our work shows that TLR9 has protumorigenic effects in pancreatic carcinoma which are distinct from its influence in extrapancreatic malignancies and from the mechanistic effects of other TLRs on pancreatic oncogenesis. © 2015 Zambirinis et al.

  18. Pancreatic stellate cells support tumour metabolism through autophagic alanine secretion.

    Sousa, Cristovão M; Biancur, Douglas E; Wang, Xiaoxu; Halbrook, Christopher J; Sherman, Mara H; Zhang, Li; Kremer, Daniel; Hwang, Rosa F; Witkiewicz, Agnes K; Ying, Haoqiang; Asara, John M; Evans, Ronald M; Cantley, Lewis C; Lyssiotis, Costas A; Kimmelman, Alec C

    2016-08-25

    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by an intense fibrotic stromal response and deregulated metabolism. The role of the stroma in PDAC biology is complex and it has been shown to play critical roles that differ depending on the biological context. The stromal reaction also impairs the vasculature, leading to a highly hypoxic, nutrient-poor environment. As such, these tumours must alter how they capture and use nutrients to support their metabolic needs. Here we show that stroma-associated pancreatic stellate cells (PSCs) are critical for PDAC metabolism through the secretion of non-essential amino acids (NEAA). Specifically, we uncover a previously undescribed role for alanine, which outcompetes glucose and glutamine-derived carbon in PDAC to fuel the tricarboxylic acid (TCA) cycle, and thus NEAA and lipid biosynthesis. This shift in fuel source decreases the tumour’s dependence on glucose and serum-derived nutrients, which are limited in the pancreatic tumour microenvironment. Moreover, we demonstrate that alanine secretion by PSCs is dependent on PSC autophagy, a process that is stimulated by cancer cells. Thus, our results demonstrate a novel metabolic interaction between PSCs and cancer cells, in which PSC-derived alanine acts as an alternative carbon source. This finding highlights a previously unappreciated metabolic network within pancreatic tumours in which diverse fuel sources are used to promote growth in an austere tumour microenvironment.

  19. Tetrandrine induces lipid accumulation through blockade of autophagy in a hepatic stellate cell line

    Miyamae, Yusaku; Nishito, Yukina; Nakai, Naomi; Nagumo, Yoko; Usui, Takeo; Masuda, Seiji; Kambe, Taiho; Nagao, Masaya

    2016-01-01

    Macroautophagy, or autophagy, is a cellular response in which unnecessary cytoplasmic components, including lipids and organelles, are self-degraded. Recent studies closely related autophagy to activation of hepatic stellate cells (HSCs), a process critical in the pathogenesis of liver fibrosis. During HSC activation, cytoplasmic lipid droplets (LDs) are degraded as autophagic cargo, and then cells express fibrogenic genes. Thus, inhibition of autophagy in HSCs is a potential therapeutic approach for attenuating liver fibrosis. We found that tetrandrine, a bisbenzylisoquinoline alkaloid isolated from Stephania tetrandra, induced lipid accumulation, a phenotype associated with quiescent HSCs, through blockade of autophagy in the rat-derived HSC line HSC-T6. Tetrandrine inhibited autophagic flux without affecting lysosomal function. A phenotypic comparison using siRNA knockdown suggested that tetrandrine may target regulators, involved in fusion between autophagosomes and lysosomes (e.g., syntaxin 17). Moreover, perilipin 1, an LD-coated protein, co-localized specifically with LC3, a marker protein for autophagosomes, in tetrandrine-treated HSC-T6 cells. This suggests a potential role for perilipin 1 in autophagy-mediated LD degradation in HSCs. Our results identified tetrandrine as a potential tool for prevention and treatment of HSC activation. - Highlights: • Autophagy is closely related to lipid degradation in hepatic stellate cells. • Tetrandrine (Tet) causes lipid accumulation via blockade of autophagy in HSC-T6 cells. • Tet blocked autophagy without affecting lysosomal function unlike bafilomycin A_1. • Perilipin 1 was specifically co-localized with LC3 in Tet-treated cells. • Perilipin 1 may play potential roles in autophagy-mediated lipid degradation.

  20. Tetrandrine induces lipid accumulation through blockade of autophagy in a hepatic stellate cell line

    Miyamae, Yusaku, E-mail: ymiyamae@lif.kyoto-u.ac.jp [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Nishito, Yukina; Nakai, Naomi [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Nagumo, Yoko; Usui, Takeo [Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Masuda, Seiji; Kambe, Taiho [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan); Nagao, Masaya, E-mail: mnagao@kais.kyoto-u.ac.jp [Graduate School of Biostudies, Kyoto University, Oiwakecho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502 (Japan)

    2016-08-12

    Macroautophagy, or autophagy, is a cellular response in which unnecessary cytoplasmic components, including lipids and organelles, are self-degraded. Recent studies closely related autophagy to activation of hepatic stellate cells (HSCs), a process critical in the pathogenesis of liver fibrosis. During HSC activation, cytoplasmic lipid droplets (LDs) are degraded as autophagic cargo, and then cells express fibrogenic genes. Thus, inhibition of autophagy in HSCs is a potential therapeutic approach for attenuating liver fibrosis. We found that tetrandrine, a bisbenzylisoquinoline alkaloid isolated from Stephania tetrandra, induced lipid accumulation, a phenotype associated with quiescent HSCs, through blockade of autophagy in the rat-derived HSC line HSC-T6. Tetrandrine inhibited autophagic flux without affecting lysosomal function. A phenotypic comparison using siRNA knockdown suggested that tetrandrine may target regulators, involved in fusion between autophagosomes and lysosomes (e.g., syntaxin 17). Moreover, perilipin 1, an LD-coated protein, co-localized specifically with LC3, a marker protein for autophagosomes, in tetrandrine-treated HSC-T6 cells. This suggests a potential role for perilipin 1 in autophagy-mediated LD degradation in HSCs. Our results identified tetrandrine as a potential tool for prevention and treatment of HSC activation. - Highlights: • Autophagy is closely related to lipid degradation in hepatic stellate cells. • Tetrandrine (Tet) causes lipid accumulation via blockade of autophagy in HSC-T6 cells. • Tet blocked autophagy without affecting lysosomal function unlike bafilomycin A{sub 1}. • Perilipin 1 was specifically co-localized with LC3 in Tet-treated cells. • Perilipin 1 may play potential roles in autophagy-mediated lipid degradation.

  1. Pancreatic Stellate Cells Have Distinct Characteristics From Hepatic Stellate Cells and Are Not the Unique Origin of Collagen-Producing Cells in the Pancreas.

    Yamamoto, Gen; Taura, Kojiro; Iwaisako, Keiko; Asagiri, Masataka; Ito, Shinji; Koyama, Yukinori; Tanabe, Kazutaka; Iguchi, Kohta; Satoh, Motohiko; Nishio, Takahiro; Okuda, Yukihiro; Ikeno, Yoshinobu; Yoshino, Kenji; Seo, Satoru; Hatano, Etsuro; Uemoto, Shinji

    2017-10-01

    The origin of collagen-producing myofibroblasts in pancreatic fibrosis is still controversial. Pancreatic stellate cells (PSCs), which have been recognized as the pancreatic counterparts of hepatic stellate cells (HSCs), are thought to play an important role in the development of pancreatic fibrosis. However, sources of myofibroblasts other than PSCs may exist because extensive studies of liver fibrosis have uncovered myofibroblasts that did not originate from HSCs. This study aimed to characterize myofibroblasts in an experimental pancreatic fibrosis model in mice. We used transgenic mice expressing green fluorescent protein via the collagen type I α1 promoter and induced pancreatic fibrosis with repetitive injections of cerulein. Collagen-producing cells that are negative for glial fibrillary acidic protein (ie, not derived from PSCs) exist in the pancreas. Pancreatic stellate cells had different characteristics from those of HSCs in a very small possession of vitamin A using mass spectrometry and a low expression of lecithin retinol acyltransferase. The microstructure of PSCs was entirely different from that of HSCs using flow cytometry and electron microscopy. Our study showed that characteristics of PSCs are different from those of HSCs, and myofibroblasts in the pancreas might be derived not only from PSCs but also from other fibrogenic cells.

  2. Rebound spiking in layer II medial entorhinal cortex stellate cells: Possible mechanism of grid cell function

    Shay, Christopher F.; Ferrante, Michele; Chapman, G. William; Hasselmo, Michael E.

    2015-01-01

    Rebound spiking properties of medial entorhinal cortex (mEC) stellate cells induced by inhibition may underlie their functional properties in awake behaving rats, including the temporal phase separation of distinct grid cells and differences in grid cell firing properties. We investigated rebound spiking properties using whole cell patch recording in entorhinal slices, holding cells near spiking threshold and delivering sinusoidal inputs, superimposed with realistic inhibitory synaptic inputs to test the capacity of cells to selectively respond to specific phases of inhibitory input. Stellate cells showed a specific phase range of hyperpolarizing inputs that elicited spiking, but non-stellate cells did not show phase specificity. In both cell types, the phase range of spiking output occurred between the peak and subsequent descending zero crossing of the sinusoid. The phases of inhibitory inputs that induced spikes shifted earlier as the baseline sinusoid frequency increased, while spiking output shifted to later phases. Increases in magnitude of the inhibitory inputs shifted the spiking output to earlier phases. Pharmacological blockade of h-current abolished the phase selectivity of hyperpolarizing inputs eliciting spikes. A network computational model using cells possessing similar rebound properties as found in vitro produces spatially periodic firing properties resembling grid cell firing when a simulated animal moves along a linear track. These results suggest that the ability of mEC stellate cells to fire rebound spikes in response to a specific range of phases of inhibition could support complex attractor dynamics that provide completion and separation to maintain spiking activity of specific grid cell populations. PMID:26385258

  3. Multidrug resistance-associated proteins are crucial for the viability of activated rat hepatic stellate cells

    Hannivoort, Rebekka A.; Dunning, Sandra; Borght, Sara Vander; Schroyen, Ben; Woudenberg, Jannes; Oakley, Fiona; Buist-Homan, Manon; van den Heuvel, Fiona A. J.; Geuken, Mariska; Geerts, Albert; Roskams, Tania; Faber, Klaas Nico; Moshage, Han

    Hepatic stellate cells (HSCs) survive and proliferate in the chronically injured liver. ATP-binding cassette (ABC) transporters play a crucial role in cell viability by transporting toxic metabolites or xenobiotics out of the cell. ABC transporter expression in HSCs and its relevance to cell

  4. Hepatic stellate cells lack AP-1 responsiveness to electrophiles and phorbol 12-myristate-13-acetate

    Reichard, John F.; Petersen, Dennis R.

    2004-01-01

    Stellate cell profibrotic gene induction and transdifferentiation are central events in liver fibrosis. Oxidative stress has been implicated as an activator of the transcription factors Nrf2 and AP-1 through shared kinase signaling pathways that also purportedly contribute to stellate cell activation. The present study examined the role of oxidative stress in ARE- and TRE-regulated gene induction in isolated hepatic stellate cells. Using a portion of the human Nqo1 promoter consisting of an ARE imbedded TRE, it was demonstrated that while the ARE was responsible for mediating inducible gene expression in response to the electrophiles 4-HNE and tBHQ, the TRE was refractory to induction by either electrophiles or PMA. It was demonstrated that stellate cells possess nuclear TRE-binding proteins that were identified as JunB, JunD, Fra1, and Fra2, which were unaffected by either electrophiles or PMA treatment. This report demonstrates that, in contrast to the ARE, the TRE and its binding cognate AP-1 did not mediate independent gene induction in hepatic stellate cells. This observation is significant given the presumed importance attributed to AP-1 in mediating profibrogenic gene expression

  5. Role of stellate cells in alcoholic liver fibrosis

    Krzysztof Plewka

    2009-07-01

    Full Text Available Many different diseases and toxins can cause liver damage, which is diffi cult to treat and often leads to the development of liver fi brosis or even cirrhosis. The key event in this process is the activation of hepatic stellate cells (HSCs. During such activation, HSCs undergo a dramatic transformation in morphology and behavior, changing from a neuronal-like to a fi broblast-like morphology. After activation, HSCs increase their proliferation rate and extracellular matrix (ECM production. Overproduction of ECM, which contains mainly collagen type I, is a direct cause of liver disruption. HSCs also produce substances which inhibit protease activities, such as TIMPs, which enhance ECM deposition in the liver. On the molecular level, HSCs are activated by cytokines, growth factors, and oxidative stress, which are abundant in affl icted liver. These factors induce intracellular signals transmitted by many kinases, the most important of which are JNK, ERK1/2, p38, TAK-1, PKC, FAK, and P3IK. Signals transmitted via these pathways change the activities of transcription factors such as Smad, AP-1, and NF-κβ. This in turn causes changes In gene transcription and ultimately alters the whole cell’s behavior and morphology. The cell begins the production collagen type I, TIMP-1, and aSMA. Activated HSCs can sustain their own activation by producing growth factors such as PDGF and TGF-β. Despite the vast knowledge about the mechanisms causing liver fi brosis and cirrhosis, there is still no effective cure. Further studies are therefore needed to solve this problem.

  6. Sonoanatomical Change of Phrenic Nerve According to Posture During Ultrasound-Guided Stellate Ganglion Block.

    Joeng, Eui Soo; Jeong, Young Cheol; Park, Bum Jun; Kang, Seok; Yang, Seung Nam; Yoon, Joon Shik

    2016-04-01

    To evaluate the risk of phrenic nerve injury during ultrasound-guided stellate ganglion block (US-SGB) according to sonoanatomy of the phrenic nerve, and determine a safer posture for needle insertion by assessing its relationship with surrounding structure according to positional change. Twenty-nine healthy volunteers were recruited and underwent ultrasound in two postures, i.e., supine position with the neck extension and head rotation, and lateral decubitus position. The transducer was placed at the anterior tubercle of the C6 level to identify phrenic nerve. The cross-sectional area (CSA), depth from skin, distance between phrenic nerve and anterior tubercle of C6 transverse process, and the angle formed by anterior tubercle, posterior tubercle and phrenic nerve were measured. The phrenic nerve was clearly identified in the intermuscular fascia layer between the anterior scalene and sternocleidomastoid muscles. The distance between the phrenic nerve and anterior tubercle was 10.33±3.20 mm with the supine position and 9.20±3.31 mm with the lateral decubitus position, respectively. The mean CSA and skin depth of phrenic nerve were not statistically different between the two positions. The angle with the supine position was 48.37°±27.43°, and 58.89°±30.02° with the lateral decubitus position. The difference of angle between the two positions was statistically significant. Ultrasound is a useful tool for assessing the phrenic nerve and its anatomical relation with other cervical structures. In addition, lateral decubitus position seems to be safer by providing wider angle for needle insertion than the supine position in US-SGB.

  7. Immunodetection of hepatic stellate cells in dogs with visceral leishmaniasis.

    Marques, Natália Cassaro; Mo Reira, Pamela Rodrigues Reina; Bertolo, Paulo Henrique Leal; Gava, Fábio Nelson; Vasconcelos, Rosemeri de Oliveira

    2018-06-01

    Hepatic stellate cells (HSC), or Ito cells, store vitamin A when at rest but undergo phenotypic changes in situations of liver injury, which may induce fibrosis, and they may participate in the immune response in the liver. The objective of the present study was to investigate the role of HSC in the livers of dogs with visceral leishmaniasis (VL). Twenty-eight livers from dogs infected with VL that were living in an area endemic for the disease were evaluated, among which 13 were asymptomatic (A) and 15 were symptomatic (S). A control group (C) was formed by five dogs from an area that was not endemic for VL. These organs were subjected to histopathological analysis (Masson's trichrome for fibrosis) and immunohistochemical analysis (Leishmania, smooth-muscle α-actin and TGF-β). In the livers from the symptomatic dogs, a moderate to severe granulomatous inflammatory reaction was observed in the capsule and in the portal, centrilobular and intralobular regions. In the asymptomatic dogs, there was slight to moderate presence of granulomas, and these were even absent in some dogs. The intensity of hepatic fibrosis was predominantly low in the infected dogs (A and S), and fibrosis was absent in the control group. The immunomarking of HSC in the infected groups (A and S) differed significantly (P = 0.0153) from that of the control group. The symptomatic dogs presented the largest number of positive cells. This group also presented a larger number of parasitized macrophages, but did not differ statistically from the asymptomatic group (P > 0.05). The cytokine TGF-β was only detected at low levels, and only in the infected animals, but this did not differ from the control group. Immunomarking for HSC was observed mainly in the nuclei of cells present in the hepatic granulomas of symptomatic dogs and in the sinusoids of the asymptomatic dogs. It was concluded that in the livers of dogs with VL, the HSC are activated and participate in the hepatic response to the

  8. Bile acids induce necrosis in pancreatic stellate cells dependent on calcium entry and sodium‐driven bile uptake

    Jakubowska, Monika A.; Gerasimenko, Julia V.; Gerasimenko, Oleg V.; Petersen, Ole H.

    2016-01-01

    Key points Acute biliary pancreatitis is a sudden and severe condition initiated by bile reflux into the pancreas.Bile acids are known to induce Ca2+ signals and necrosis in isolated pancreatic acinar cells but the effects of bile acids on stellate cells are unexplored.Here we show that cholate and taurocholate elicit more dramatic Ca2+ signals and necrosis in stellate cells compared to the adjacent acinar cells in pancreatic lobules; whereas taurolithocholic acid 3‐sulfate primarily affects acinar cells.Ca2+ signals and necrosis are strongly dependent on extracellular Ca2+ as well as Na+; and Na+‐dependent transport plays an important role in the overall bile acid uptake in pancreatic stellate cells.Bile acid‐mediated pancreatic damage can be further escalated by bradykinin‐induced signals in stellate cells and thus killing of stellate cells by bile acids might have important implications in acute biliary pancreatitis. Abstract Acute biliary pancreatitis, caused by bile reflux into the pancreas, is a serious condition characterised by premature activation of digestive enzymes within acinar cells, followed by necrosis and inflammation. Bile acids are known to induce pathological Ca2+ signals and necrosis in acinar cells. However, bile acid‐elicited signalling events in stellate cells remain unexplored. This is the first study to demonstrate the pathophysiological effects of bile acids on stellate cells in two experimental models: ex vivo (mouse pancreatic lobules) and in vitro (human cells). Sodium cholate and taurocholate induced cytosolic Ca2+ elevations in stellate cells, larger than those elicited simultaneously in the neighbouring acinar cells. In contrast, taurolithocholic acid 3‐sulfate (TLC‐S), known to induce Ca2+ oscillations in acinar cells, had only minor effects on stellate cells in lobules. The dependence of the Ca2+ signals on extracellular Na+ and the presence of sodium–taurocholate cotransporting polypeptide (NTCP) indicate a Na

  9. Pancreatic stellate cells enhance stem cell-like phenotypes in pancreatic cancer cells

    Hamada, Shin; Masamune, Atsushi; Takikawa, Tetsuya; Suzuki, Noriaki; Kikuta, Kazuhiro; Hirota, Morihisa; Hamada, Hirofumi; Kobune, Masayoshi; Satoh, Kennichi; Shimosegawa, Tooru

    2012-01-01

    Highlights: ► Pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. ► Pancreatic cancer cells co-cultured with PSCs showed enhanced spheroid formation. ► Expression of stem cell-related genes ABCG2, Nestin and LIN28 was increased. ► Co-injection of PSCs enhanced tumorigenicity of pancreatic cancer cells in vivo. ► This study suggested a novel role of PSCs as a part of the cancer stem cell niche. -- Abstract: The interaction between pancreatic cancer cells and pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, is receiving increasing attention. There is accumulating evidence that PSCs promote the progression of pancreatic cancer by increasing cancer cell proliferation and invasion as well as by protecting them from radiation- and gemcitabine-induced apoptosis. Recent studies have identified that a portion of cancer cells, called “cancer stem cells”, within the entire cancer tissue harbor highly tumorigenic and chemo-resistant phenotypes, which lead to the recurrence after surgery or re-growth of the tumor. The mechanisms that maintain the “stemness” of these cells remain largely unknown. We hypothesized that PSCs might enhance the cancer stem cell-like phenotypes in pancreatic cancer cells. Indirect co-culture of pancreatic cancer cells with PSCs enhanced the spheroid-forming ability of cancer cells and induced the expression of cancer stem cell-related genes ABCG2, Nestin and LIN28. In addition, co-injection of PSCs enhanced tumorigenicity of pancreatic cancer cells in vivo. These results suggested a novel role of PSCs as a part of the cancer stem cell niche.

  10. Glutathione and antioxidant enzymes serve complementary roles in protecting activated hepatic stellate cells against hydrogen peroxide-induced cell death

    Dunning, Sandra; Rehman, Atta Ur; Tiebosch, Marjolein H.; Hannivoort, Rebekka A.; Haijer, Floris W.; Woudenberg, Jannes; van den Heuvel, Fiona A. J.; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han

    2013-01-01

    Background: In chronic liver disease, hepatic stellate cells (HSCs) are activated, highly proliferative and produce excessive amounts of extracellular matrix, leading to liver fibrosis. Elevated levels of toxic reactive oxygen species (ROS) produced during chronic liver injury have been implicated

  11. Photoacoustic microscopy of complex regional pain syndrome type I (CRPS-1) after stellate ganglion blocks in vivo

    Zhou, Yong; Yi, Xiaobin; Xing, Wenxin; Hu, Song; Maslov, Konstantin I.; Wang, Lihong V.

    2015-03-01

    We used photoacoustic microscopy (PAM) to assist diagnoses and monitor the progress and treatment outcome of complex regional pain syndrome type 1 (CRPS-1). Blood vasculature and oxygen saturation (sO2) were imaged by PAM in eight adult patients with CRPS-1. Patients' hands and cuticles were imaged both before and after stellate ganglion block (SGB) for comparison. For all patients, both the vascular structure and sO2 could be assessed by PAM. In addition, more vessels and stronger signals were observed after SGB.

  12. Interferon gamma peptidomimetic targeted to hepatic stellate cells ameliorates acute and chronic liver fibrosis in vivo

    Bansal, Ruchi; Prakash, Jai; De Ruiter, Marieke; Poelstra, Klaas

    2014-01-01

    Hepatic stellate cells play a crucial role in the pathogenesis of hepatic fibrosis. Thus, pharmacological inhibition of pro-fibrotic activities of these cells might lead to an effective therapy for this disease. Among the potent antifibrotics, interferon gamma (IFN gamma), a proinflammatory

  13. Interferon gamma peptidomimetic targeted to hepatic stellate cells ameliorates acute and chronic liver fibrosis in vivo

    Bansal, Ruchi; Prakash, Jai; de Ruiter, Marieke; Poelstra, Klaas

    2014-01-01

    Hepatic stellate cells play a crucial role in the pathogenesis of hepatic fibrosis. Thus, pharmacological inhibition of pro-fibrotic activities of these cells might lead to an effective therapy for this disease. Among the potent anti-fibrotics, interferon gamma (IFNγ), a proinflammatory cytokine, is

  14. Melatonin suppresses activation of hepatic stellate cells through ROR alpha-mediated inhibition of 5-lipoxygenase

    Shajari, Shiva; Laliena, Almudena; Heegsma, Janette; Jesus Tunon, Maria; Moshage, Han; Faber, Klaas Nico

    2015-01-01

    Liver fibrosis is scar tissue resulting from an uncontrolled wound-healing process in response to chronic liver injury. Liver damage generates an inflammatory reaction that activates hepatic stellate cells (HSC) that transdifferentiate from quiescent cells that control retinol metabolism to

  15. Recombinant fusion protein of albumin-retinol binding protein inactivates stellate cells

    Choi, Soyoung; Park, Sangeun; Kim, Suhyun; Lim, Chaeseung; Kim, Jungho; Cha, Dae Ryong; Oh, Junseo

    2012-01-01

    Highlights: ► We designed novel recombinant albumin-RBP fusion proteins. ► Expression of fusion proteins inactivates pancreatic stellate cells (PSCs). ► Fusion proteins are successfully internalized into and inactivate PSCs. ► RBP moiety mediates cell specific uptake of fusion protein. -- Abstract: Quiescent pancreatic- (PSCs) and hepatic- (HSCs) stellate cells store vitamin A (retinol) in lipid droplets via retinol binding protein (RBP) receptor and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells which play a key role in the fibrogenesis. Despite extensive investigations, there is, however, currently no appropriate therapy available for tissue fibrosis. We previously showed that the expression of albumin, composed of three homologous domains (I–III), inhibits stellate cell activation, which requires its high-affinity fatty acid-binding sites asymmetrically distributed in domain I and III. To attain stellate cell-specific uptake, albumin (domain I/III) was coupled to RBP; RBP-albumin domain III (R-III) and albumin domain I -RBP-albumin III (I-R-III). To assess the biological activity of fusion proteins, cultured PSCs were used. Like wild type albumin, expression of R-III or I-R-III in PSCs after passage 2 (activated PSCs) induced phenotypic reversal from activated to fat-storing cells. On the other hand, R-III and I-R-III, but not albumin, secreted from transfected 293 cells were successfully internalized into and inactivated PSCs. FPLC-purified R-III was found to be internalized into PSCs via caveolae-mediated endocytosis, and its efficient cellular uptake was also observed in HSCs and podocytes among several cell lines tested. Moreover, tissue distribution of intravenously injected R-III was closely similar to that of RBP. Therefore, our data suggest that albumin-RBP fusion protein comprises of stellate cell inactivation-inducing moiety and targeting moiety, which may lead to the development of effective anti

  16. Effectiveness and Patient Acceptability of Stellate Ganglion Block (SGB) for Treatment of Posttraumatic Stress Disorder (PTSD) Symptoms among Active Duty Military Members

    2017-03-01

    as well as active  engagement through social media channels. We also are exploring the placement of paid  advertisements  in local  newspapers , both...Page 1 of 2 AWARD NUMBER: W81XWH-15-2-0015 TITLE: Effectiveness and Patient Acceptability of Stellate Ganglion Block (SGB) for Treatment of...SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-2-0015 Effectiveness and Patient Acceptability of Stellate Ganglion Block (SGB) for Treatment of

  17. Stellate-cell lipidosis in liver biopsy specimens. Recognition and significance.

    Levine, Pascale Hummel; Delgado, Yara; Theise, Neil D; West, A Brian

    2003-02-01

    Hepatic stellate-cell lipidosis due to hypervitaminosis A can lead to cirrhosis, which can be averted by restricting vitamin A intake. Other causes, including the use of synthetic retinoids, have been postulated. We studied the frequency and etiology of stellate-cell lipidosis in patients undergoing liver biopsy for reasons other than vitamin A abuse. Fourteen cases (1.1%) were identified retrospectively among 1,235 nontransplant liver biopsy specimens examined from January 1995 through December 1999. Diagnostic criteria included the following: lipid-laden cells in the space of Disse; small, dark, crescent-shaped nuclei with inconspicuous nucleoli; and wispy cytoplasmic strands separating fat droplets. Patient details, reason for biopsy, and medication use were studied. Reasons for biopsy included hepatitis C (10 cases), abnormal liver enzyme levels (2 cases), methotrexate use (1 case), and alcohol abuse (1 case). Hypervitaminosis A was not suspected clinically in the 5 patients who used oral vitamin A or 3 who used topical tretinoin (Retin-A). In 6 patients, no cause of stellate-cell lipidosis was discerned. Stellate-cell lipidosis should be reported to alert clinicians to a potentially preventable form of liver injury.

  18. Endocytosis of collagen by hepatic stellate cells regulates extracellular matrix dynamics.

    Bi, Yan; Mukhopadhyay, Dhriti; Drinane, Mary; Ji, Baoan; Li, Xing; Cao, Sheng; Shah, Vijay H

    2014-10-01

    Hepatic stellate cells (HSCs) generate matrix, which in turn may also regulate HSCs function during liver fibrosis. We hypothesized that HSCs may endocytose matrix proteins to sense and respond to changes in microenvironment. Primary human HSCs, LX2, or mouse embryonic fibroblasts (MEFs) [wild-type; c-abl(-/-); or Yes, Src, and Fyn knockout mice (YSF(-/-))] were incubated with fluorescent-labeled collagen or gelatin. Fluorescence-activated cell sorting analysis and confocal microscopy were used for measuring cellular internalization of matrix proteins. Targeted PCR array and quantitative real-time PCR were used to evaluate gene expression changes. HSCs and LX2 cells endocytose collagens in a concentration- and time-dependent manner. Endocytosed collagen colocalized with Dextran 10K, a marker of macropinocytosis, and 5-ethylisopropyl amiloride, an inhibitor of macropinocytosis, reduced collagen internalization by 46%. Cytochalasin D and ML7 blocked collagen internalization by 47% and 45%, respectively, indicating that actin and myosin are critical for collagen endocytosis. Wortmannin and AKT inhibitor blocked collagen internalization by 70% and 89%, respectively, indicating that matrix macropinocytosis requires phosphoinositide-3-kinase (PI3K)/AKT signaling. Overexpression of dominant-negative dynamin-2 K44A blocked matrix internalization by 77%, indicating a role for dynamin-2 in matrix macropinocytosis. Whereas c-abl(-/-) MEF showed impaired matrix endocytosis, YSF(-/-) MEF surprisingly showed increased matrix endocytosis. It was also associated with complex gene regulations that related with matrix dynamics, including increased matrix metalloproteinase 9 (MMP-9) mRNA levels and zymographic activity. HSCs endocytose matrix proteins through macropinocytosis that requires a signaling network composed of PI3K/AKT, dynamin-2, and c-abl. Interaction with extracellular matrix regulates matrix dynamics through modulating multiple gene expressions including MMP-9

  19. Bile acids induce hepatic stellate cell proliferation via activation of the epidermal growth factor receptor

    Svegliati-Baroni, G; Ridolfi, F; Hannivoort, R; Saccomanno, S; Homan, M; De Minicis, S; Jansen, PLM; Candelaresi, C; Benedetti, A; Moshage, H

    Background B Aims: Hepatic stellate cell (HSC) proliferation is a key event in the development of liver fibrosis. In many liver diseases, HSCs are exposed to inflammatory cytokines, reactive oxygen species, and bile acids. Although inflammatory cytokines and reactive oxygen species are known to

  20. Bile acids induce hepatic stellate cell proliferation via activation of the epidermal growth factor receptor

    Svegliati-Baroni, Gianluca; Ridolfi, Francesco; Hannivoort, Rebekka; Saccomanno, Stefania; Homan, Manon; de Minicis, Samuele; Jansen, Peter L. M.; Candelaresi, Cinzia; Benedetti, Antonio; Moshage, Han

    2005-01-01

    BACKGROUND & AIMS: Hepatic stellate cell (HSC) proliferation is a key event in the development of liver fibrosis. In many liver diseases, HSCs are exposed to inflammatory cytokines, reactive oxygen species, and bile acids. Although inflammatory cytokines and reactive oxygen species are known to

  1. Cannabinoids reduce markers of inflammation and fibrosis in pancreatic stellate cells.

    Christoph W Michalski

    2008-02-01

    Full Text Available While cannabinoids have been shown to ameliorate liver fibrosis, their effects in chronic pancreatitis and on pancreatic stellate cells (PSC are unknown.The activity of the endocannabinoid system was evaluated in human chronic pancreatitis (CP tissues. In vitro, effects of blockade and activation of cannabinoid receptors on pancreatic stellate cells were characterized. In CP, cannabinoid receptors were detected predominantly in areas with inflammatory changes, stellate cells and nerves. Levels of endocannabinoids were decreased compared with normal pancreas. Cannabinoid-receptor-1 antagonism effectuated a small PSC phenotype and a trend toward increased invasiveness. Activation of cannabinoid receptors, however, induced de-activation of PSC and dose-dependently inhibited growth and decreased IL-6 and MCP-1 secretion as well as fibronectin, collagen1 and alphaSMA levels. De-activation of PSC was partially reversible using a combination of cannabinoid-receptor-1 and -2 antagonists. Concomitantly, cannabinoid receptor activation specifically decreased invasiveness of PSC, MMP-2 secretion and led to changes in PSC phenotype accompanied by a reduction of intracellular stress fibres.Augmentation of the endocannabinoid system via exogenously administered cannabinoid receptor agonists specifically induces a functionally and metabolically quiescent pancreatic stellate cell phenotype and may thus constitute an option to treat inflammation and fibrosis in chronic pancreatitis.

  2. Changes in Inward Rectifier K+ Channels in Hepatic Stellate Cells During Primary Culture

    Lee, Dong Hyeon; Kong, In Deok; Lee, Joong-Woo

    2008-01-01

    Purpose This study examined the expression and function of inward rectifier K+ channels in cultured rat hepatic stellate cells (HSC). Materials and Methods The expression of inward rectifier K+ channels was measured using real-time RT-PCR, and electrophysiological properties were determined using the gramicidin-perforated patch-clamp technique. Results The dominant inward rectifier K+ channel subtypes were Kir2.1 and Kir6.1. These dominant K+ channel subtypes decreased significantly during the primary culture throughout activation process. HSC can be classified into two subgroups: one with an inward-rectifying K+ current (type 1) and the other without (type 2). The inward current was blocked by Ba2+ (100 µM) and enhanced by high K+ (140 mM), more prominently in type 1 HSC. There was a correlation between the amplitude of the Ba2+-sensitive current and the membrane potential. In addition, Ba2+ (300 µM) depolarized the membrane potential. After the culture period, the amplitude of the inward current decreased and the membrane potential became depolarized. Conclusion HSC express inward rectifier K+ channels, which physiologically regulate membrane potential and decrease during the activation process. These results will potentially help determine properties of the inward rectifier K+ channels in HSC as well as their roles in the activation process. PMID:18581597

  3. Adenosine monophosphate-activated protein kinase modulates the activated phenotype of hepatic stellate cells.

    Caligiuri, Alessandra; Bertolani, Cristiana; Guerra, Cristina Tosti; Aleffi, Sara; Galastri, Sara; Trappoliere, Marco; Vizzutti, Francesco; Gelmini, Stefania; Laffi, Giacomo; Pinzani, Massimo; Marra, Fabio

    2008-02-01

    Adiponectin limits the development of liver fibrosis and activates adenosine monophosphate-activated protein kinase (AMPK). AMPK is a sensor of the cellular energy status, but its possible modulation of the fibrogenic properties of hepatic stellate cells (HSCs) has not been established. In this study, we investigated the role of AMPK activation in the biology of activated human HSCs. A time-dependent activation of AMPK was observed in response to a number of stimuli, including globular adiponectin, 5-aminoimidazole-4-carboxamide-1-beta-4-ribofuranoside (AICAR), or metformin. All these compounds significantly inhibited platelet-derived growth factor (PDGF)-stimulated proliferation and migration of human HSCs and reduced the secretion of monocyte chemoattractant protein-1. In addition, AICAR limited the secretion of type I procollagen. Knockdown of AMPK by gene silencing increased the mitogenic effects of PDGF, confirming the negative modulation exerted by this pathway on HSCs. AMPK activation did not reduce PDGF-dependent activation of extracellular signal-regulated kinase (ERK) or Akt at early time points, whereas a marked inhibition was observed 24 hours after addition of PDGF, reflecting a block in cell cycle progression. In contrast, AICAR blocked short-term phosphorylation of ribosomal S6 kinase (p70(S6K)) and 4E binding protein-1 (4EBP1), 2 downstream effectors of the mammalian target of rapamycin (mTOR) pathway, by PDGF. The ability of interleukin-a (IL-1) to activate nuclear factor kappa B (NF-kappaB) was also reduced by AICAR. Activation of AMPK negatively modulates the activated phenotype of HSCs.

  4. Effects of treatment with Maraviroc a CCR5 inhibitor on a human hepatic stellate cell line.

    Coppola, Nicola; Perna, Angelica; Lucariello, Angela; Martini, Salvatore; Macera, Margherita; Carleo, Maria A; Guerra, Germano; Esposito, Vincenzo; De Luca, Antonio

    2018-08-01

    After an acute liver damage, tissue regeneration repairs lesions with degradation of deposed fibrotic material, while mechanisms of tissue restoration are persistently activated following several repeated injuries, inducing deposition of extracellular matrix. (ECM). Factors responsible for ECM remodeling have been identified in a pathway involving a family of zinc-dependent enzyme matrix metalloproteinases (MMPs), together with tissue inhibitor of metalloproteinases (TIMPs). Recent experimental models suggested a role of CCR5 receptor in the genesis of liver fibrosis. Drawing from these background we decided to evaluate the effects of the treatment with the CCR5 inhibitor Maraviroc on LX-2, a human hepatic stellate cell line (HSC). Treatment with Maraviroc resulted in a block in S phase of LX-2 cells with increased expression levels of cyclin D1 and p21 while the expression of p53 was reduced. Treatment with Maraviroc was also able to block the accumulation of fibrillar collagens and extracellular matrix proteins (ECM), as demonstrated by the decrease of specific markers as Collagen type I, α-SMA, and TGF-β1. In addition we observed a down regulation of both metalloproteins (MMP-2, MMP-9), used for the degradation of the extracellular matrix and their inhibitors (TIMP-1, TIMP-2). The identification of a compound that may modulate the dynamic of liver fibrosis could be crucial in all chronic liver diseases. Maraviroc could play an important role because, in addition to its own anti-HIV activity, it could reduce the release of pro-inflammatory citokynes implicated in liver fibrogenesis. © 2018 Wiley Periodicals, Inc.

  5. The epigenetic regulation of stem cell factors in hepatic stellate cells.

    Reister, Sven; Kordes, Claus; Sawitza, Iris; Häussinger, Dieter

    2011-10-01

    The epigenetic regulation by DNA methylation is an important mechanism to control the expression of stem cell factors as demonstrated in tumor cells. It was recently shown that hepatic stellate cells (HSC) express stem/progenitor cell factors and have a differentiation potential. The aim of this work was to investigate if the expression of stem cell markers is regulated by DNA methylation during activation of rat HSC. It was found that CD133, Notch1, and Notch3 are regulated via DNA methylation in HSC, whereas Nestin shows no DNA methylation in HSC and other undifferentiated cells such as embryonic stem cells and umbilical cord blood stem cells from rats. In contrast to this, DNA methylation controls Nestin expression in differentiated cells like hepatocytes and the hepatoma cell line H4IIE. Demethylation by 5-Aza-2-deoxycytidine was sufficient to induce Nestin in H4IIE cells. In quiescent stellate cells and embryonic stem cells, the Nestin expression was suppressed by histone H3 methylation at lysine 9, which is another epigenetic mechanism. Apart from the known induction of Nestin in cultured HSC, this intermediate filament protein was also induced after partial hepatectomy, indicating activation of HSC during liver regeneration. Taken together, this study demonstrates for the first time that the expression of stem cell-associated factors such as CD133, Notch1, and Notch3 is controlled by DNA methylation in HSC. The regulation of Nestin by DNA methylation seems to be restricted to differentiated cells, whereas undifferentiated cells use different epigenetic mechanisms such as histone H3 methylation to control Nestin expression.

  6. Replacement of Retinyl Esters by Polyunsaturated Triacylglycerol Species in Lipid Droplets of Hepatic Stellate Cells during Activation

    Testerink, Nicole; Ajat, Mokrish; Houweling, Martin; Brouwers, Jos F.; Pully, Vishnu V.; van Manen, Henk-Jan; Otto, Cees; Helms, J. Bernd; Vaandrager, Arie B.

    2012-01-01

    Activation of hepatic stellate cells has been recognized as one of the first steps in liver injury and repair. During activation, hepatic stellate cells transform into myofibroblasts with concomitant loss of their lipid droplets (LDs) and production of excessive extracellular matrix. Here we aimed to obtain more insight in the dynamics and mechanism of LD loss. We have investigated the LD degradation processes in rat hepatic stellate cells in vitro with a combined approach of confocal Raman microspectroscopy and mass spectrometric analysis of lipids (lipidomics). Upon activation of the hepatic stellate cells, LDs reduce in size, but increase in number during the first 7 days, but the total volume of neutral lipids did not decrease. The LDs also migrate to cellular extensions in the first 7 days, before they disappear. In individual hepatic stellate cells. all LDs have a similar Raman spectrum, suggesting a similar lipid profile. However, Raman studies also showed that the retinyl esters are degraded more rapidly than the triacylglycerols upon activation. Lipidomic analyses confirmed that after 7 days in culture hepatic stellate cells have lost most of their retinyl esters, but not their triacylglycerols and cholesterol esters. Furthermore, we specifically observed a large increase in triacylglycerol-species containing polyunsaturated fatty acids, partly caused by an enhanced incorporation of exogenous arachidonic acid. These results reveal that lipid droplet degradation in activated hepatic stellate cells is a highly dynamic and regulated process. The rapid replacement of retinyl esters by polyunsaturated fatty acids in LDs suggests a role for both lipids or their derivatives like eicosanoids during hepatic stellate cell activation. PMID:22536341

  7. Replacement of retinyl esters by polyunsaturated triacylglycerol species in lipid droplets of hepatic stellate cells during activation.

    Nicole Testerink

    Full Text Available Activation of hepatic stellate cells has been recognized as one of the first steps in liver injury and repair. During activation, hepatic stellate cells transform into myofibroblasts with concomitant loss of their lipid droplets (LDs and production of excessive extracellular matrix. Here we aimed to obtain more insight in the dynamics and mechanism of LD loss. We have investigated the LD degradation processes in rat hepatic stellate cells in vitro with a combined approach of confocal Raman microspectroscopy and mass spectrometric analysis of lipids (lipidomics. Upon activation of the hepatic stellate cells, LDs reduce in size, but increase in number during the first 7 days, but the total volume of neutral lipids did not decrease. The LDs also migrate to cellular extensions in the first 7 days, before they disappear. In individual hepatic stellate cells. all LDs have a similar Raman spectrum, suggesting a similar lipid profile. However, Raman studies also showed that the retinyl esters are degraded more rapidly than the triacylglycerols upon activation. Lipidomic analyses confirmed that after 7 days in culture hepatic stellate cells have lost most of their retinyl esters, but not their triacylglycerols and cholesterol esters. Furthermore, we specifically observed a large increase in triacylglycerol-species containing polyunsaturated fatty acids, partly caused by an enhanced incorporation of exogenous arachidonic acid. These results reveal that lipid droplet degradation in activated hepatic stellate cells is a highly dynamic and regulated process. The rapid replacement of retinyl esters by polyunsaturated fatty acids in LDs suggests a role for both lipids or their derivatives like eicosanoids during hepatic stellate cell activation.

  8. Redox regulation of stress signals: possible roles of dendritic stellate TRX producer cells (DST cell types).

    Yodoi, Junji; Nakamura, Hajime; Masutani, Hiroshi

    2002-01-01

    Thioredoxin (TRX) is a 12 kDa protein with redox-active dithiol (Cys-Gly-Pro-Cys) in the active site. TRX is induced by a variety of stresses including viral infection and inflammation. The promoter sequences of the TRX gene contain a series of stress-responsive elements including ORE, ARE, XRE, CRE and SP-1. TRX promotes DNA binding of transcription factors such as NF-kappaB, AP-1 and p53. TRX interacts with target proteins modulating the activity of those proteins. We have identified TRX binding protein-2 (TBP-2), which was identical to vitamin D3 up-regulated protein 1 (VDUP1). Potential action of TBP-2/VDUP1 as a redox-sensitive tumor suppressor will be discussed. There is accumulating evidence for the involvement of TRX in the protection against infectious and inflammatory disorders. We will discuss the role of TRX-dependent redox regulation of the host defense mechanism, in particular its relation to the emerging concept of constitutive and/or inducible TRX on special cell types with dendritic and stellate morphology in the immune, endocrine and nervous systems, which we provisionally designate as dendritic stellate TRX producer cells (DST cell types).

  9. Stellate Cells in the Medial Entorhinal Cortex Are Required for Spatial Learning

    Sarah A. Tennant

    2018-01-01

    Full Text Available Spatial learning requires estimates of location that may be obtained by path integration or from positional cues. Grid and other spatial firing patterns of neurons in the superficial medial entorhinal cortex (MEC suggest roles in behavioral estimation of location. However, distinguishing the contributions of path integration and cue-based signals to spatial behaviors is challenging, and the roles of identified MEC neurons are unclear. We use virtual reality to dissociate linear path integration from other strategies for behavioral estimation of location. We find that mice learn to path integrate using motor-related self-motion signals, with accuracy that decreases steeply as a function of distance. We show that inactivation of stellate cells in superficial MEC impairs spatial learning in virtual reality and in a real world object location recognition task. Our results quantify contributions of path integration to behavior and corroborate key predictions of models in which stellate cells contribute to location estimation.

  10. Recombinant fusion protein of albumin-retinol binding protein inactivates stellate cells

    Choi, Soyoung; Park, Sangeun; Kim, Suhyun [Laboratory of Cellular Oncology, Korea University Graduate School of Medicine, Ansan, Gyeonggi do 425-707 (Korea, Republic of); Lim, Chaeseung [Department of Laboratory Medicine, Korea University Guro Hospital, Seoul 152-703 (Korea, Republic of); Kim, Jungho [Department of Life Science, Sogang University, Seoul 121-742 (Korea, Republic of); Cha, Dae Ryong [Department of Internal Medicine, Korea University Ansan Hospital, Ansan, Gyeonggi do 425-020 (Korea, Republic of); Oh, Junseo, E-mail: ohjs@korea.ac.kr [Laboratory of Cellular Oncology, Korea University Graduate School of Medicine, Ansan, Gyeonggi do 425-707 (Korea, Republic of)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer We designed novel recombinant albumin-RBP fusion proteins. Black-Right-Pointing-Pointer Expression of fusion proteins inactivates pancreatic stellate cells (PSCs). Black-Right-Pointing-Pointer Fusion proteins are successfully internalized into and inactivate PSCs. Black-Right-Pointing-Pointer RBP moiety mediates cell specific uptake of fusion protein. -- Abstract: Quiescent pancreatic- (PSCs) and hepatic- (HSCs) stellate cells store vitamin A (retinol) in lipid droplets via retinol binding protein (RBP) receptor and, when activated by profibrogenic stimuli, they transform into myofibroblast-like cells which play a key role in the fibrogenesis. Despite extensive investigations, there is, however, currently no appropriate therapy available for tissue fibrosis. We previously showed that the expression of albumin, composed of three homologous domains (I-III), inhibits stellate cell activation, which requires its high-affinity fatty acid-binding sites asymmetrically distributed in domain I and III. To attain stellate cell-specific uptake, albumin (domain I/III) was coupled to RBP; RBP-albumin{sup domain} {sup III} (R-III) and albumin{sup domain} {sup I}-RBP-albumin{sup III} (I-R-III). To assess the biological activity of fusion proteins, cultured PSCs were used. Like wild type albumin, expression of R-III or I-R-III in PSCs after passage 2 (activated PSCs) induced phenotypic reversal from activated to fat-storing cells. On the other hand, R-III and I-R-III, but not albumin, secreted from transfected 293 cells were successfully internalized into and inactivated PSCs. FPLC-purified R-III was found to be internalized into PSCs via caveolae-mediated endocytosis, and its efficient cellular uptake was also observed in HSCs and podocytes among several cell lines tested. Moreover, tissue distribution of intravenously injected R-III was closely similar to that of RBP. Therefore, our data suggest that albumin-RBP fusion protein comprises

  11. Antiproliferative and cytotoxic effects of purple pitanga (Eugenia uniflora L.) extract on activated hepatic stellate cells.

    Denardin, Cristiane C; Parisi, Mariana M; Martins, Leo A M; Terra, Silvia R; Borojevic, Radovan; Vizzotto, Márcia; Perry, Marcos L S; Emanuelli, Tatiana; Guma, Fátima T C R

    2014-01-01

    The presence of phenolic compounds in fruit- and vegetable-rich diets has attracted researchers' attention due to their health-promoting effects. The objective of this study was to evaluate the effects of purple pitanga (Eugenia uniflora L.) extract on cell proliferation, viability, mitochondrial membrane potential, cell death and cell cycle in murine activated hepatic stellate cells (GRX). Cell viability by 3-(4,5-dimethylthiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was significantly decreased on cells treated with 50 and 100 µg ml(-1) of purple pitanga extract for 48 and 72 h, and the percentage of dead cell stained with 7-amino-actinomycin D was significantly higher in treated cells. The reduction of cell proliferation was dose dependent, and we also observed alterations on cell cycle progression. At all times studied, GRX cells treated with 50 and 100 µg ml(-1) of purple pitanga showed a significant reduction in cellular mitochondrial content as well as a decrease in mitochondrial membrane potential. Furthermore, our results indicated that purple pitanga extract induces early and late apoptosis/necrosis and necrotic death in GRX cells. This is the first report describing the antiproliferative, cytotoxic and apoptotic activity for E. uniflora fruits in hepatic stellate cells. The present study provides a foundation for the prevention and treatment of liver fibrosis, and more studies will be carried to elucidate this effect. Copyright © 2013 John Wiley & Sons, Ltd.

  12. Pancreatic stellate cells promote epithelial-mesenchymal transition in pancreatic cancer cells

    Kikuta, Kazuhiro; Masamune, Atsushi; Watanabe, Takashi; Ariga, Hiroyuki; Itoh, Hiromichi; Hamada, Shin; Satoh, Kennichi; Egawa, Shinichi; Unno, Michiaki; Shimosegawa, Tooru

    2010-01-01

    Research highlights: → Recent studies have shown that pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. → Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and scattered, fibroblast-like appearance. → PSCs decreased the expression of epithelial markers but increased that of mesenchymal markers, along with increased migration. → This study suggests epithelial-mesenchymal transition as a novel mechanism by which PSCs contribute to the aggressive behavior of pancreatic cancer cells. -- Abstract: The interaction between pancreatic cancer cells and pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, is receiving increasing attention. There is accumulating evidence that PSCs promote the progression of pancreatic cancer by increasing cancer cell proliferation and invasion as well as by protecting them from radiation- and gemcitabine-induced apoptosis. Because epithelial-mesenchymal transition (EMT) plays a critical role in the progression of pancreatic cancer, we hypothesized that PSCs promote EMT in pancreatic cancer cells. Panc-1 and SUIT-2 pancreatic cancer cells were indirectly co-cultured with human PSCs isolated from patients undergoing operation for pancreatic cancer. The expression of epithelial and mesenchymal markers was examined by real-time PCR and immunofluorescent staining. The migration of pancreatic cancer cells was examined by scratch and two-chamber assays. Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and a scattered, fibroblast-like appearance. The expression of E-cadherin, cytokeratin 19, and membrane-associated β-catenin was decreased, whereas vimentin and Snail (Snai-1) expression was increased more in cancer cells co-cultured with PSCs than in mono-cultured cells. The migration of pancreatic cancer cells was increased by co-culture with PSCs. The PSC-induced decrease of E-cadherin expression was not altered by treatment with anti

  13. Hedgehog-mediated paracrine interaction between hepatic stellate cells and marrow-derived mesenchymal stem cells

    Lin Nan; Tang Zhaofeng; Deng Meihai; Zhong Yuesi; Lin Jizong; Yang Xuhui; Xiang Peng; Xu Ruiyun

    2008-01-01

    During liver injury, bone marrow-derived mesenchymal stem cells (MSCs) can migrate and differentiate into hepatocytes. Hepatic stellate cell (SC) activation is a pivotal event in the development of liver fibrosis. Therefore, we hypothesized that SCs may play an important role in regulating MSC proliferation and differentiation through the paracrine signaling pathway. We demonstrate that MSCs and SCs both express hedgehog (Hh) pathway components, including its ligands, receptors, and target genes. Transwell co-cultures of SCs and MSCs showed that the SCs produced sonic hedgehog (Shh), which enhanced the proliferation and differentiation of MSCs. These findings demonstrate that SCs indirectly modulate the activity of MSCs in vitro via the Hh pathway, and provide a plausible explanation for the mechanisms of transplanted MSCs in the treatment of liver fibrosis

  14. Superoxide anions and hydrogen peroxide inhibit proliferation of activated rat stellate cells and induce different modes of cell death

    Dunning, Sandra; Hannivoort, Rebekka A.; de Boer, Jan Freark; Buist-Homan, Manon; Faber, Klaas Nico; Moshage, Han

    In chronic liver injury, hepatic stellate cells (HSCs) proliferate and produce excessive amounts of connective tissue causing liver fibrosis and cirrhosis. Oxidative stress has been implicated as a driving force of HSC activation and proliferation, although contradictory results have been described.

  15. Saikosaponin d induces cell death through caspase-3-dependent, caspase-3-independent and mitochondrial pathways in mammalian hepatic stellate cells

    Chen, Ming-Feng; Huang, S. Joseph; Huang, Chao-Cheng; Liu, Pei-Shan; Lin, Kun-I; Liu, Ching-Wen; Hsieh, Wen-Chuan; Shiu, Li-Yen; Chen, Chang-Han

    2016-01-01

    Saikosaponin d (SSd) is one of the main active triterpene saponins in Bupleurum falcatum. It has a steroid-like structure, and is reported to have pharmacological activities, including liver protection in rat, cell cycle arrest and apoptosis induction in several cancer cell lines. However, the biological functions and molecular mechanisms of mammalian cells under SSd treatment are still unclear. The cytotoxicity and apoptosis of hepatic stellate cells (HSCs) upon SSd treatment were discovered by MTT assay, colony formation assay and flow cytometry. The collage I/III, caspase activity and apoptotic related genes were examined by quantitative PCR, Western blotting, immunofluorescence and ELISA. The mitochondrial functions were monitored by flow cytometry, MitoTracker staining, ATP production and XF24 bioenergetic assay. This study found that SSd triggers cell death via an apoptosis path. An example of this path might be typical apoptotic morphology, increased sub-G1 phase cell population, inhibition of cell proliferation and activation of caspase-3 and caspase-9. However, the apoptotic effects induced by SSd are partially blocked by the caspase-3 inhibitor, Z-DEVD-FMK, suggesting that SSd may trigger both HSC-T6 and LX-2 cell apoptosis through caspase-3-dependent and independent pathways. We also found that SSd can trigger BAX and BAK translocation from the cytosol to the mitochondria, resulting in mitochondrial function inhibition, membrane potential disruption. Finally, SSd also increases the release of apoptotic factors. The overall analytical data indicate that SSd-elicited cell death may occur through caspase-3-dependent, caspase-3-independent and mitochondrial pathways in mammalian HSCs, and thus can delay the formation of liver fibrosis by reducing the level of HSCs

  16. Monocytes infiltrate the pancreas via the MCP-1/CCR2 pathway and differentiate into stellate cells.

    Kazuko Ino

    Full Text Available Recent studies have shown that monocytes possess pluripotent plasticity. We previously reported that monocytes could differentiate into hepatic stellate cells. Although stellate cells are also present in the pancreas, their origin remains unclear. An accumulation of enhanced green fluorescent protein (EGFP(+CD45(- cells was observed in the pancreases and livers of chimeric mice, which were transplanted with a single hematopoietic stem cell isolated from EGFP-transgenic mice and treated with carbon tetrachloride (CCl4. Because the vast majority of EGFP(+CD45(- cells in the pancreas expressed stellate cell-associated antigens such as vimentin, desmin, glial fibrillary acidic protein, procollagen-I, and α-smooth muscle actin, they were characterized as pancreatic stellate cells (PaSCs. EGFP(+ PaSCs were also observed in CCl4-treated mice adoptively transferred with monocytes but not with other cell lineages isolated from EGFP-transgenic mice. The expression of monocyte chemoattractant protein-1 (MCP-1 and angiotensin II (Ang II increased in the pancreas of CCl4-treated mice and their respective receptors, C-C chemokine receptor 2 (CCR2 and Ang II type 1 receptor (AT1R, were expressed on Ly6C(high monocytes isolated from EGFP-transgenic mice. We examined the effect of an AT1R antagonist, irbesartan, which is also a CCR2 antagonist, on the migration of monocytes into the pancreas. Monocytes migrated toward MCP-1 but not Ang II in vitro. Irbesartan inhibited not only their in vitro chemotaxis but also in vivo migration of adoptively transferred monocytes from peripheral blood into the pancreas. Irbesartan treatment significantly reduced the numbers of EGFP(+F4/80(+CCR2(+ monocytic cells and EGFP(+ PaSCs in the pancreas of CCl4-treated chimeric mice receiving EGFP(+ bone marrow cells. A specific CCR2 antagonist RS504393 inhibited the occurrence of EGFP(+ PaSCs in injured mice. We propose that CCR2(+ monocytes migrate into the pancreas possibly via the

  17. Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

    Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji; Yoon, Kun-Ho; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho, E-mail: kihos@catholic.ac.kr

    2013-09-20

    Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation.

  18. Oxidative stress plays a role in high glucose-induced activation of pancreatic stellate cells

    Ryu, Gyeong Ryul; Lee, Esder; Chun, Hyun-Ji; Yoon, Kun-Ho; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho

    2013-01-01

    Highlights: •High glucose increased production of reactive oxygen species in cultured pancreatic stellate cells. •High glucose facilitated the activation of these cells. •Antioxidant treatment attenuated high glucose-induced activation of these cells. -- Abstract: The activation of pancreatic stellate cells (PSCs) is thought to be a potential mechanism underlying islet fibrosis, which may contribute to progressive β-cell failure in type 2 diabetes. Recently, we demonstrated that antioxidants reduced islet fibrosis in an animal model of type 2 diabetes. However, there is no in vitro study demonstrating that high glucose itself can induce oxidative stress in PSCs. Thus, PSCs were isolated and cultured from Sprague Dawley rats, and treated with high glucose for 72 h. High glucose increased the production of reactive oxygen species. When treated with high glucose, freshly isolated PSCs exhibited myofibroblastic transformation. During early culture (passage 1), PSCs treated with high glucose contained an increased number of α-smooth muscle actin-positive cells. During late culture (passages 2–5), PSCs treated with high glucose exhibited increases in cell proliferation, the expression of fibronectin and connective tissue growth factor, release of interleukin-6, transforming growth factor-β and collagen, and cell migration. Finally, the treatment of PSCs with high glucose and antioxidants attenuated these changes. In conclusion, we demonstrated that high glucose increased oxidative stress in primary rat PSCs, thereby facilitating the activation of these cells, while antioxidant treatment attenuated high glucose-induced PSC activation

  19. Exosomes derived from pancreatic cancer cells induce activation and profibrogenic activities in pancreatic stellate cells.

    Masamune, Atsushi; Yoshida, Naoki; Hamada, Shin; Takikawa, Tetsuya; Nabeshima, Tatsuhide; Shimosegawa, Tooru

    2018-01-01

    Pancreatic cancer cells (PCCs) interact with pancreatic stellate cells (PSCs), which play a pivotal role in pancreatic fibrogenesis, to develop the cancer-conditioned tumor microenvironment. Exosomes are membrane-enclosed nanovesicles, and have been increasingly recognized as important mediators of cell-to-cell communications. The aim of this study was to clarify the effects of PCC-derived exosomes on cell functions in PSCs. Exosomes were isolated from the conditioned medium of Panc-1 and SUIT-2 PCCs. Human primary PSCs were treated with PCC-derived exosomes. PCC-derived exosomes stimulated the proliferation, migration, activation of ERK and Akt, the mRNA expression of α-smooth muscle actin (ACTA2) and fibrosis-related genes, and procollagen type I C-peptide production in PSCs. Ingenuity pathway analysis of the microarray data identified transforming growth factor β1 and tumor necrosis factor as top upstream regulators. PCCs increased the expression of miR-1246 and miR-1290, abundantly contained in PCC-derived exosomes, in PSCs. Overexpression of miR-1290 induced the expression of ACTA2 and fibrosis-related genes in PSCs. In conclusion, PCC-derived exosomes stimulate activation and profibrogenic activities in PSCs. Exosome-mediated interactions between PSCs and PCCs might play a role in the development of the tumor microenvironment. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Retinol metabolism in hepatic stellate cells : a new vision

    Bin Md Ajat, M.M.

    2015-01-01

    Vitamin A (all-trans-retinol) or its derivatives are involved in many physiological processes ranging from vision to cells differentiation. In mammals retinol is stored as retinyl ester (RE) and the liver is the major site for RE storage in the body. The liver is made of various cell types and REs

  1. HS-173, a Novel PI3K Inhibitor, Attenuates the Activation of Hepatic Stellate Cells in Liver Fibrosis

    Son, Mi Kwon; Ryu, Ye-Lim; Jung, Kyung Hee; Lee, Hyunseung; Lee, Hee Seung; Yan, Hong Hua; Park, Heon Joo; Ryu, Ji-Kan; Suh, Jun–Kyu; Hong, Sungwoo; Hong, Soon-Sun

    2013-01-01

    Hepatic stellate cells (HSCs) are the primary source of matrix components in liver disease such as fibrosis. Phosphatidylinositol 3-kinase (PI3K) signaling in HSCs has been shown to induce fibrogenesis. In this study, we evaluated the anti-fibrotic activity of a novel imidazopyridine analogue (HS-173) in human HSCs as well as mouse liver fibrosis. HS-173 strongly suppressed the growth and proliferation of HSCs and induced the arrest at the G2/M phase and apoptosis in HSCs. Furthermore, it reduced the expression of extracellular matrix components such as collagen type I, which was confirmed by an in vivo study. We also observed that HS-173 blocked the PI3K/Akt signaling pathway in vitro and in vivo. Taken together, HS-173 suppressed fibrotic responses such as cell proliferation and collagen synthesis by blocking PI3K/Akt signaling. Therefore, we suggest that this compound may be an effective therapeutic agent for ameliorating liver fibrosis through the inhibition of PI3K signaling. PMID:24326778

  2. Clinical Guidelines for Stellate Ganglion Block to Treat Anxiety Associated With Posttraumatic Stress Disorder

    2015-07-01

    maintained by the sympathetic branch of the autonomic nervous system as well as the somatic nervous system. Block- ade of the sympathetic nervous...through sternocleidomas- toid, continuing just ventral to the tip of the anterior tubercle of C6, then continuing on until the needle tip has just...know that questioning them is just another way to monitor how they are doing. It is absolutely critical to constantly keep the needle tip in view. If

  3. Methylation of Septin9 mediated by DNMT3a enhances hepatic stellate cells activation and liver fibrogenesis

    Wu, Yuting, E-mail: wuyuting1302@sina.com; Bu, Fangtian; Yu, Haixia; Li, Wanxia; Huang, Cheng; Meng, Xiaoming; Zhang, Lei; Ma, Taotao; Li, Jun, E-mail: lj@ahmu.edu.cn

    2017-01-15

    Liver fibrosis, resulting from chronic and persistent injury to the liver, is a worldwide health problem. Advanced liver fibrosis results in cirrhosis, liver failure and even hepatocellular cancer (HCC), often eventually requiring liver transplantation, poses a huge health burden on the global community. However, the specific pathogenesis of liver fibrosis remains not fully understood. Numerous basic and clinical studies have provided evidence that epigenetic modifications, especially DNA methylation, might contribute to the activation of hepatic stellate cells (HSCs), the pivotal cell type responsible for the fibrous scar in liver. Here, reduced representation bisulfite sequencing (RRBS) and bisulfite pyrosequencing PCR (BSP) analysis identified hypermethylation status of Septin9 (Sept9) gene in liver fibrogenesis. Sept9 protein was dramatically decreased in livers of CCl4-treated mice and immortalized HSC-T6 cells exposed to TGF-β1. Nevertheless, the suppression of Sept9 could be blocked by DNMT3a-siRNA and DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine (5-azadC). Overexpressed Sept9 attenuated TGF-β1-induced expression of myofibroblast markers α-SMA and Col1a1, accompanied by up-regulation of cell apoptosis-related proteins. Conversely, RNAi-mediated silencing of Sept9 enhanced accumulation of extracellular matrix. These observations suggested that Sept9 contributed to alleviate liver fibrosis might partially through promoting activated HSCs apoptosis and this anti-fibrogenesis effect might be blocked by DNMT-3a mediated methylation of Sept9. Therefore, pharmacological agents that inhibit Sept9 methylation and increase its expression could be considered as valuable treatments for liver fibrosis. - Highlights: • This is the first report of Sept9 methylation and function in liver fibrosis. • Ectopic expression of Sept9 could block the liver fibrogenesis. • DNMT3a might be responsible for the suppression of Sept9 in liver fibrosis.

  4. Methylation of Septin9 mediated by DNMT3a enhances hepatic stellate cells activation and liver fibrogenesis

    Wu, Yuting; Bu, Fangtian; Yu, Haixia; Li, Wanxia; Huang, Cheng; Meng, Xiaoming; Zhang, Lei; Ma, Taotao; Li, Jun

    2017-01-01

    Liver fibrosis, resulting from chronic and persistent injury to the liver, is a worldwide health problem. Advanced liver fibrosis results in cirrhosis, liver failure and even hepatocellular cancer (HCC), often eventually requiring liver transplantation, poses a huge health burden on the global community. However, the specific pathogenesis of liver fibrosis remains not fully understood. Numerous basic and clinical studies have provided evidence that epigenetic modifications, especially DNA methylation, might contribute to the activation of hepatic stellate cells (HSCs), the pivotal cell type responsible for the fibrous scar in liver. Here, reduced representation bisulfite sequencing (RRBS) and bisulfite pyrosequencing PCR (BSP) analysis identified hypermethylation status of Septin9 (Sept9) gene in liver fibrogenesis. Sept9 protein was dramatically decreased in livers of CCl4-treated mice and immortalized HSC-T6 cells exposed to TGF-β1. Nevertheless, the suppression of Sept9 could be blocked by DNMT3a-siRNA and DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine (5-azadC). Overexpressed Sept9 attenuated TGF-β1-induced expression of myofibroblast markers α-SMA and Col1a1, accompanied by up-regulation of cell apoptosis-related proteins. Conversely, RNAi-mediated silencing of Sept9 enhanced accumulation of extracellular matrix. These observations suggested that Sept9 contributed to alleviate liver fibrosis might partially through promoting activated HSCs apoptosis and this anti-fibrogenesis effect might be blocked by DNMT-3a mediated methylation of Sept9. Therefore, pharmacological agents that inhibit Sept9 methylation and increase its expression could be considered as valuable treatments for liver fibrosis. - Highlights: • This is the first report of Sept9 methylation and function in liver fibrosis. • Ectopic expression of Sept9 could block the liver fibrogenesis. • DNMT3a might be responsible for the suppression of Sept9 in liver fibrosis.

  5. The P2X7 Receptor Supports Both Life and Death in Fibrogenic Pancreatic Stellate Cells

    Haanes, Kristian; Schwab, Albrecht; Novak, Ivana

    2012-01-01

    The pancreatic stellate cells (PSCs) have complex roles in pancreas, including tissue repair and fibrosis. PSCs surround ATP releasing exocrine cells, but little is known about purinergic receptors and their function in PSCs. Our aim was to resolve whether PSCs express the multifunctional P2X7...... versions of the receptor. In culture, the proliferation rate of the KO PSCs was significantly lower. Inclusion of apyrase reduced the proliferation rate in both WT and KO PSCs, indicating importance of endogenous ATP. Exogenous ATP had a two-sided effect. Proliferation of both WT and KO cells...... inhibitor az10606120. The P2X7 receptor-pore inhibitor A438079 partially prevented cell death induced by millimolar ATP concentrations. This study shows that ATP and P2X7 receptors are important regulators of PSC proliferation and death, and therefore might be potential targets for treatments of pancreatic...

  6. N-terminal region of gelsolin induces apoptosis of activated hepatic stellate cells by a caspase-dependent mechanism.

    Budhaditya Mazumdar

    Full Text Available Activated hepatic stellate cells (HSCs are the major source for alteration of extracellular matrix in fibrosis and cirrhosis. Conditioned medium (CM collected from immortalized human hepatocytes (IHH have earlier been shown to be responsible for apoptosis of HSCs. In this study, we have shown that antibodies raised against a peptide derived from a linear B-cell epitope in the N-terminal region of gelsolin identified a gelsolin fragment in IHH CM. Analysis of activated stellate cell death by CM collected from Huh7 cells transfected with plasmids encoding gelsolin deletion mutants suggested that the N-terminal half of gelsolin contained sequences which were responsible for stellate cell death. Further analysis determined that this activity was restricted to a region encompassing amino acids 1-70 in the gelsolin sequence; antibody directed to an epitope within this region was able to neutralize stellate cell death. Gelsolin modulation of cell death using this fragment involved upregulation of TRAIL-R1 and TRAIL-R2, and involved caspase 3 activation by extrinsic pathway. The apoptotic activity of N-terminal gelsolin fragments was restricted to activated but not quiescent stellate cells indicating its potential application in therapeutic use as an anti-fibrotic agent. Gelsolin fragments encompassing N-terminal regions in polypeptides of different molecular sizes were detected by N-terminal peptide specific antiserum in IHH CM immunoprecipitated with chronically HCV infected patient sera, suggesting the presence of autoantibodies generated against N-terminal gelsolin fragments in patients with chronic liver disease.

  7. Reduction of Fibrogenesis by Selective Delivery of a Rho Kinase Inhibitor to Hepatic Stellate Cells in Mice

    van Beuge, M. M.; Prakash, J.; Lacombe, M.; Gosens, R.; Post, E.; Reker-Smit, C.; Beljaars, L.; Poelstra, K.

    One of the pathways activated during liver fibrosis is the Rho kinase pathway, which regulates activation, migration, and contraction of hepatic stellate cells (HSC). Inhibition of this kinase by the Rho kinase inhibitor Y27632 [(+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide

  8. Brivanib attenuates hepatic fibrosis in vivo and stellate cell activation in vitro by inhibition of FGF, VEGF and PDGF signaling.

    Ikuo Nakamura

    Full Text Available Brivanib is a selective inhibitor of vascular endothelial growth factor receptor (VEGFR and fibroblast growth factor receptor (FGFR tyrosine kinases, which are both involved in mechanisms of liver fibrosis. We hypothesized that inhibition of VEGFR and FGFR by brivanib would inhibit liver fibrosis. We therefore examined the effect of brivanib on liver fibrosis in three mouse models of fibrosis.In vivo, we induced liver fibrosis by bile duct ligation (BDL, chronic carbon tetrachloride (CCl4, and chronic thioacetamide (TAA administration. Liver fibrosis was examined by immunohistochemistry and Western immunoblotting. In vitro, we used LX-2 human hepatic stellate cells (HSCs to assess the effect of brivanib on stellate cell proliferation and activation.After in vivo induction with BDL, CCl4, and TAA, mice treated with brivanib showed reduced liver fibrosis and decreased expression of collagen Iα1 and α-smooth muscle actin in the liver. In vitro, brivanib decreased proliferation of HSCs induced by platelet-derived growth factor (PDGF, VEGF, and FGF. Brivanib also decreased stellate cell viability and inhibited PDGFBB-induced phosphorylation of its cognate receptor.Brivanib reduces liver fibrosis in three different animal models and decreases human hepatic stellate cell activation. Brivanib may represent a novel therapeutic approach to treatment of liver fibrosis and prevention of liver cancer.

  9. Ionone Derivatives from the Mycelium of Phellinus linteus and the Inhibitory Effect on Activated Rat Hepatic Stellate Cells

    Shiow-Chyn Huang

    2016-05-01

    Full Text Available Three new γ-ionylideneacetic acid derivatives, phellinulins A–C (1–3, were characterized from the mycelium extract of Phellinus linteus. The chemical structures were established based on the spectroscopic analysis. In addition, phellinulin A (1 was subjected to the examination of effects on activated rat hepatic stellate cells and exhibited significant inhibition of hepatic fibrosis.

  10. Non-linear Membrane Properties in Entorhinal Cortical Stellate Cells Reduce Modulation of Input-Output Responses by Voltage Fluctuations

    Fernandez, Fernando R.; Malerba, Paola; White, John A.

    2015-01-01

    The presence of voltage fluctuations arising from synaptic activity is a critical component in models of gain control, neuronal output gating, and spike rate coding. The degree to which individual neuronal input-output functions are modulated by voltage fluctuations, however, is not well established across different cortical areas. Additionally, the extent and mechanisms of input-output modulation through fluctuations have been explored largely in simplified models of spike generation, and with limited consideration for the role of non-linear and voltage-dependent membrane properties. To address these issues, we studied fluctuation-based modulation of input-output responses in medial entorhinal cortical (MEC) stellate cells of rats, which express strong sub-threshold non-linear membrane properties. Using in vitro recordings, dynamic clamp and modeling, we show that the modulation of input-output responses by random voltage fluctuations in stellate cells is significantly limited. In stellate cells, a voltage-dependent increase in membrane resistance at sub-threshold voltages mediated by Na+ conductance activation limits the ability of fluctuations to elicit spikes. Similarly, in exponential leaky integrate-and-fire models using a shallow voltage-dependence for the exponential term that matches stellate cell membrane properties, a low degree of fluctuation-based modulation of input-output responses can be attained. These results demonstrate that fluctuation-based modulation of input-output responses is not a universal feature of neurons and can be significantly limited by subthreshold voltage-gated conductances. PMID:25909971

  11. Interferon gamma peptidomimetic targeted to hepatic stellate cells ameliorates acute and chronic liver fibrosis in vivo.

    Bansal, Ruchi; Prakash, Jai; De Ruiter, Marieke; Poelstra, Klaas

    2014-04-10

    Hepatic stellate cells play a crucial role in the pathogenesis of hepatic fibrosis. Thus, pharmacological inhibition of pro-fibrotic activities of these cells might lead to an effective therapy for this disease. Among the potent anti-fibrotics, interferon gamma (IFNγ), a proinflammatory cytokine, is highly efficacious but it failed in clinical trials due to the poor efficacy and multiple adverse effects attributed to the ubiquitous IFNγ receptor (IFNγR) expression. To resolve these drawbacks, we chemically synthesized a chimeric molecule containing (a) IFNγ signaling peptide (IFNγ peptidomimetic, mimγ) that retains the agonistic activities of IFNγ but lacks an extracellular receptor recognition sequence for IFNγR; coupled via heterobifunctional PEG linker to (b) bicyclic platelet derived growth factor beta receptor (PDGFβR)-binding peptide (BiPPB) to induce internalization into the stellate cells that express PDGFβR. The synthesized targeted IFNγ peptidomimetic (mimγ-BiPPB) was extensively investigated for its anti-fibrotic and adverse effects in acute and chronic CCl4-induced liver fibrosis models in mice. Treatment with mimγ-BiPPB, after the onset of disease, markedly inhibited both early and established hepatic fibrosis as reflected by a reduced intrahepatic α-SMA, desmin and collagen-I mRNA expression and protein levels. While untargeted mimγ and BiPPB had no effect, and native IFNγ only induced a moderate reduction. Additionally, no off-target effects, e.g. systemic inflammation, were found with mimγ-BiPPB, which were substantially observed in mice treated with native IFNγ. The present study highlights the beneficial effects of a novel BiPPB mediated cell-specific targeting of IFNγ peptidomimetic to the disease-inducing cells and therefore represents a highly potential therapeutic approach to treat fibrotic diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Ferulic acid suppresses activation of hepatic stellate cells through ERK1/2 and Smad signaling pathways in vitro.

    Xu, Tianjiao; Pan, Zhi; Dong, Miaoxian; Yu, Chunlei; Niu, Yingcai

    2015-01-01

    Hepatic stellate cells (HSCs) are the primary source of matrix components in hepatic fibrosis. Ferulic acid (FA) has antifibrotic potential in renal and cardiac disease. However, whether FA comprises inhibitive effects of HSCs activation remains to be clarified. This study aims at evaluating the hypothesis that FA inhibits extracellular matrix (ECM)-related gene expression by the interruption of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) or/and Smad signaling pathways in HSC-T6. Our results indicated that FA significantly inhibited both viability and activation of HSC-T6 cells in vitro. In addition, we demonstrated, for the first time, that FA dramatically inhibited the expression of α1(I) collagen (Col-I) and fibronectin at levels of transcription and translation. Moreover, FA treatment inhibited Smad transcriptional activity, as evaluated by transient transfection with a plasmid construction containing SMAD response element and the luciferase reporter gene. Furthermore, FA inhibition of HSCs activation involved in both focal adhesion kinase (FAK)-dependent ERK1/2 and Smad signaling pathways with independent manner. Blocking transforming growth factor-β by a neutralizing antibody caused a marked reduction in both ERK1/2 and Smad signaling. These results support FA as an effective therapeutic agent for the prevention and treatment of hepatic fibrosis. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Substance P increases liver fibrosis by differential changes in senescence of cholangiocytes and hepatic stellate cells.

    Wan, Ying; Meng, Fanyin; Wu, Nan; Zhou, Tianhao; Venter, Julie; Francis, Heather; Kennedy, Lindsey; Glaser, Trenton; Bernuzzi, Francesca; Invernizzi, Pietro; Glaser, Shannon; Huang, Qiaobing; Alpini, Gianfranco

    2017-08-01

    Substance P (SP) is involved in the proliferation of cholangiocytes in bile duct-ligated (BDL) mice and human cholangiocarcinoma growth by interacting with the neurokinin-1 receptor (NK-1R). To identify whether SP regulates liver fibrosis during cholestasis, wild-type or NK-1R knockout (NK-1R -/- ) mice that received BDL or sham surgery and multidrug resistance protein 2 knockout (Mdr2 -/- ) mice treated with either an NK-1R antagonist (L-733,060) or saline were used. Additionally, wild-type mice were treated with SP or saline intraperitoneally. In vivo, there was increased expression of tachykinin precursor 1 (coding SP) and NK-1R in both BDL and Mdr2 -/- mice compared to wild-type mice. Expression of tachykinin precursor 1 and NK-1R was significantly higher in liver samples from primary sclerosing cholangitis patients compared to healthy controls. Knockout of NK-1R decreased BDL-induced liver fibrosis, and treatment with L-733,060 resulted in decreased liver fibrosis in Mdr2 -/- mice, which was shown by decreased sirius red staining, fibrosis gene and protein expression, and reduced transforming growth factor-β1 levels in serum and cholangiocyte supernatants. Furthermore, we observed that reduced liver fibrosis in NK-1R -/- mice with BDL surgery or Mdr2 -/- mice treated with L-733,060 was associated with enhanced cellular senescence of hepatic stellate cells and decreased senescence of cholangiocytes. In vitro, L-733,060 inhibited SP-induced expression of fibrotic genes in hepatic stellate cells and cholangiocytes; treatment with L-733,060 partially reversed the SP-induced decrease of senescence gene expression in cultured hepatic stellate cells and the SP-induced increase of senescence-related gene expression in cultured cholangiocytes. Collectively, our results demonstrate the regulatory effects of the SP/NK-1R axis on liver fibrosis through changes in cellular senescence during cholestatic liver injury. (Hepatology 2017;66:528-541). © 2017 by the American

  14. The let-7/Lin28 axis regulates activation of hepatic stellate cells in alcoholic liver injury.

    McDaniel, Kelly; Huang, Li; Sato, Keisaku; Wu, Nan; Annable, Tami; Zhou, Tianhao; Ramos-Lorenzo, Sugeily; Wan, Ying; Huang, Qiaobing; Francis, Heather; Glaser, Shannon; Tsukamoto, Hidekazu; Alpini, Gianfranco; Meng, Fanyin

    2017-07-07

    The let-7/Lin28 axis is associated with the regulation of key cellular regulatory genes known as microRNAs in various human disorders and cancer development. This study evaluated the role of the let-7/Lin28 axis in regulating a mesenchymal phenotype of hepatic stellate cells in alcoholic liver injury. We identified that ethanol feeding significantly down-regulated several members of the let-7 family in mouse liver, including let-7a and let-7b. Similarly, the treatment of human hepatic stellate cells (HSCs) with lipopolysaccharide (LPS) and transforming growth factor-β (TGF-β) significantly decreased the expressions of let-7a and let-7b. Conversely, overexpression of let-7a and let-7b suppressed the myofibroblastic activation of cultured human HSCs induced by LPS and TGF-β, as evidenced by repressed ACTA2 (α-actin 2), COL1A1 (collagen 1A1), TIMP1 (TIMP metallopeptidase inhibitor 1), and FN1 (fibronectin 1); this supports the notion that HSC activation is controlled by let-7. A combination of bioinformatics, dual-luciferase reporter assay, and Western blot analysis revealed that Lin28B and high-mobility group AT-hook (HMGA2) were the direct targets of let-7a and let-7b. Furthermore, Lin28B deficiency increased the expression of let-7a/let-7b as well as reduced HSC activation and liver fibrosis in mice with alcoholic liver injury. This feedback regulation of let-7 by Lin28B is verified in hepatic stellate cells isolated by laser capture microdissection from the model. The identification of the let-7/Lin28 axis as an important regulator of HSC activation as well as its upstream modulators and down-stream targets will provide insights into the involvement of altered microRNA expression in contributing to the pathogenesis of alcoholic liver fibrosis and novel therapeutic approaches for human alcoholic liver diseases. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Hepatic stellate cells secreted hepatocyte growth factor contributes to the chemoresistance of hepatocellular carcinoma.

    Guofeng Yu

    Full Text Available As the main source of extracellular matrix proteins in tumor stroma, hepatic stellate cells (HSCs have a great impact on biological behaviors of hepatocellular carcinoma (HCC. In the present study, we have investigated a mechanism whereby HSCs modulate the chemoresistance of hepatoma cells. We used human HSC line lx-2 and chemotherapeutic agent cisplatin to investigate their effects on human HCC cell line Hep3B. The results showed that cisplatin resistance in Hep3B cells was enhanced with LX-2 CM (cultured medium exposure in vitro as well as co-injection with LX-2 cells in null mice. Meanwhile, in presence of LX-2 CM, Hep3B cells underwent epithelial to mesenchymal transition (EMT and upregulation of cancer stem cell (CSC -like properties. Besides, LX-2 cells synthesized and secreted hepatic growth factor (HGF into the CM. HGF receptor tyrosine kinase mesenchymal-epithelial transition factor (Met was activated in Hep3B cells after LX-2 CM exposure. The HGF level of LX-2 CM could be effectively reduced by using HGF neutralizing antibody. Furthermore, depletion of HGF in LX-2 CM abolished its effects on activation of Met as well as promotion of the EMT, CSC-like features and cisplatin resistance in Hep3B cells. Collectively, secreting HGF into tumor milieu, HSCs may decrease hepatoma cells sensitization to chemotherapeutic agents by promoting EMT and CSC-like features via HGF/Met signaling.

  16. Regulation of Hepatic Stellate Cells and Fibrogenesis by Fibroblast Growth Factors

    Justin D. Schumacher

    2016-01-01

    Full Text Available Fibroblast growth factors (FGFs are a family of growth factors critically involved in developmental, physiological, and pathological processes, including embryogenesis, angiogenesis, wound healing, and endocrine functions. In the liver, several FGFs are produced basally by hepatocytes and hepatic stellate cells (HSCs. Upon insult to the liver, expression of FGFs in HSCs is greatly upregulated, stimulating hepatocyte regeneration and growth. Various FGF isoforms have also been shown to directly induce HSC proliferation and activation thereby enabling autocrine and paracrine regulation of HSC function. Regulation of HSCs by the endocrine FGFs, namely, FGF15/19 and FGF21, has also recently been identified. With the ability to modulate HSC proliferation and transdifferentiation, targeting FGF signaling pathways constitutes a promising new therapeutic strategy to treat hepatic fibrosis.

  17. Differential effects of arsenic trioxide on chemosensitization in human hepatic tumor and stellate cell lines

    Rangwala Fatima

    2012-09-01

    Full Text Available Abstract Background Crosstalk between malignant hepatocytes and the surrounding peritumoral stroma is a key modulator of hepatocarcinogenesis and therapeutic resistance. To examine the chemotherapy resistance of these two cellular compartments in vitro, we evaluated a well-established hepatic tumor cell line, HepG2, and an adult hepatic stellate cell line, LX2. The aim was to compare the chemosensitization potential of arsenic trioxide (ATO in combination with sorafenib or fluorouracil (5-FU, in both hepatic tumor cells and stromal cells. Methods Cytotoxicity of ATO, 5-FU, and sorafenib, alone and in combination against HepG2 cells and LX2 cells was measured by an automated high throughput cell-based proliferation assay. Changes in survival and apoptotic signaling pathways were analyzed by flow cytometry and western blot. Gene expression of the 5-FU metabolic enzyme, thymidylate synthase, was analyzed by real time PCR. Results Both HepG2 and LX2 cell lines were susceptible to single agent sorafenib and ATO at 24 hr (ATO IC50: 5.3 μM in LX2; 32.7 μM in HepG2; Sorafenib IC50: 11.8 μM in LX2; 9.9 μM in HepG2. In contrast, 5-FU cytotoxicity required higher concentrations and prolonged (48–72 hr drug exposure. Concurrent ATO and 5-FU treatment of HepG2 cells was synergistic, leading to increased cytotoxicity due in part to modulation of thymidylate synthase levels by ATO. Concurrent ATO and sorafenib treatment showed a trend towards increased HepG2 cytotoxicity, possibly due to a significant decrease in MAPK activation in comparison to treatment with ATO alone. Conclusions ATO differentially sensitizes hepatic tumor cells and adult hepatic stellate cells to 5-FU and sorafenib. Given the importance of both of these cell types in hepatocarcinogenesis, these data have implications for the rational development of anti-cancer therapy combinations for the treatment of hepatocellular carcinoma (HCC.

  18. Differential effects of arsenic trioxide on chemosensitization in human hepatic tumor and stellate cell lines

    Rangwala, Fatima; Williams, Kevin P; Smith, Ginger R; Thomas, Zainab; Allensworth, Jennifer L; Lyerly, H Kim; Diehl, Anna Mae; Morse, Michael A; Devi, Gayathri R

    2012-01-01

    Crosstalk between malignant hepatocytes and the surrounding peritumoral stroma is a key modulator of hepatocarcinogenesis and therapeutic resistance. To examine the chemotherapy resistance of these two cellular compartments in vitro, we evaluated a well-established hepatic tumor cell line, HepG2, and an adult hepatic stellate cell line, LX2. The aim was to compare the chemosensitization potential of arsenic trioxide (ATO) in combination with sorafenib or fluorouracil (5-FU), in both hepatic tumor cells and stromal cells. Cytotoxicity of ATO, 5-FU, and sorafenib, alone and in combination against HepG2 cells and LX2 cells was measured by an automated high throughput cell-based proliferation assay. Changes in survival and apoptotic signaling pathways were analyzed by flow cytometry and western blot. Gene expression of the 5-FU metabolic enzyme, thymidylate synthase, was analyzed by real time PCR. Both HepG2 and LX2 cell lines were susceptible to single agent sorafenib and ATO at 24 hr (ATO IC 50 : 5.3 μM in LX2; 32.7 μM in HepG2; Sorafenib IC 50 : 11.8 μM in LX2; 9.9 μM in HepG2). In contrast, 5-FU cytotoxicity required higher concentrations and prolonged (48–72 hr) drug exposure. Concurrent ATO and 5-FU treatment of HepG2 cells was synergistic, leading to increased cytotoxicity due in part to modulation of thymidylate synthase levels by ATO. Concurrent ATO and sorafenib treatment showed a trend towards increased HepG2 cytotoxicity, possibly due to a significant decrease in MAPK activation in comparison to treatment with ATO alone. ATO differentially sensitizes hepatic tumor cells and adult hepatic stellate cells to 5-FU and sorafenib. Given the importance of both of these cell types in hepatocarcinogenesis, these data have implications for the rational development of anti-cancer therapy combinations for the treatment of hepatocellular carcinoma (HCC)

  19. Effect of TNF-like weak inducer of apoptosis and its receptor on migration of hepatic stellate cells

    SU Min

    2018-01-01

    Full Text Available Objective To investigate the effect of TNF-like weak inducer of apoptosis (TWAEK and its receptor fibroblast growth factor-inducible 14 (Fn14 on the migration of hepatic stellate cells and the possible mechanism. Methods The human hepatic stellate cell line LX-2 cells were treated with TWEAK or Fn14 specific small interfering RNA (Fn14 siRNA+TWEAK. Transwell chamber was used to observe the migration of hepatic stellate cells, and real-time PCR and Western blot were used to measure the expression of matrix metalloproteinase-9 (MMP9. The independent samples t-test was used for comparison of continuous data between two groups; a one-way analysis of variance was used for comparison between multiple groups, and the least significant difference t-test was used for further comparison between two groups. Results Compared with normal LX-2 cells, the TWEAK group had a significant increase in the migration of LX-2 cells (105±8 vs 164±17, t=5.287,P<0.01, and compared with the negative control group, the Fn14 siRNA+TWEAK group had a significant reduction in the number of migrated cells (122±9 vs 58±7, t=9.836, P<0.01. When LX-2 cells were treated with TWEAK, the mRNA and protein expression of MMP9 increased in a time-dependent manner (both P<0.05, while the Fn14 siRNA+TWEAK group had significant reductions in the mRNA and protein expression of MMP9 compared with the TWEAK group (t=5.358, P<0.01. Conclusion TWEAK and its receptor Fn14 can promote the migration of hepatic stellate cells by upregulating MMP9, and blockade of this pathway may become a potential target for the treatment of liver fibrosis.

  20. Canonical Wnt signaling maintains the quiescent stage of hepatic stellate cells

    Kordes, Claus; Sawitza, Iris; Haeussinger, Dieter

    2008-01-01

    It is well known that hepatic stellate cells (HSC) develop into cells, which are thought to contribute to liver fibrogenesis. Recent data suggest that HSC are progenitor cells with the capacity to differentiate into cells of endothelial and hepatocyte lineages. The present study shows that β-catenin-dependent canonical Wnt signaling is active in freshly isolated HSC of rats. Mimicking of the canonical Wnt pathway in cultured HSC by TWS119, an inhibitor of the glycogen synthase kinase 3β, led to reduced β-catenin phosphorylation, induced nuclear translocation of β-catenin, elevated glutamine synthetase production, impeded synthesis of α-smooth muscle actin and Wnt5a, but promoted the expression of glial fibrillary acidic protein, Wnt10b, and paired-like homeodomain transcription factor 2c. In addition, canonical Wnt signaling lowered DNA synthesis and hindered HSC from entering the cell cycle. The findings demonstrate that β-catenin-dependent Wnt signaling maintains the quiescent state of HSC and, similar to stem and progenitor cells, influences their developmental fate

  1. Identification of markers for quiescent pancreatic stellate cells in the normal human pancreas.

    Nielsen, Michael Friberg Bruun; Mortensen, Michael Bau; Detlefsen, Sönke

    2017-10-01

    Pancreatic stellate cells (PSCs) play a central role as source of fibrogenic cells in pancreatic cancer and chronic pancreatitis. In contrast to quiescent hepatic stellate cells (qHSCs), a specific marker for quiescent PSCs (qPSCs) that can be used in formalin-fixed and paraffin embedded (FFPE) normal human pancreatic tissue has not been identified. The aim of this study was to identify a marker enabling the identification of qPSCs in normal human FFPE pancreatic tissue. Immunohistochemical (IHC), double-IHC, immunofluorescence (IF) and double-IF analyses were carried out using a tissue microarray consisting of cores with normal human pancreatic tissue. Cores with normal human liver served as control. Antibodies directed against adipophilin, α-SMA, CD146, CRBP-1, cytoglobin, desmin, GFAP, nestin, S100A4 and vinculin were examined, with special emphasis on their expression in periacinar cells in the normal human pancreas and perisinusoidal cells in the normal human liver. The immunolabelling capacity was evaluated according to a semiquantitative scoring system. Double-IF of the markers of interest together with markers for other periacinar cells was performed. Moreover, the utility of histochemical stains for the identification of human qPSCs was examined, and their ultrastructure was revisited by electron microscopy. Adipophilin, CRBP-1, cytoglobin and vinculin were expressed in qHSCs in the liver, whereas cytoglobin and adipophilin were expressed in qPSCs in the pancreas. Adipophilin immunohistochemistry was highly dependent on the preanalytical time interval (PATI) from removal of the tissue to formalin fixation. Cytoglobin, S100A4 and vinculin were expressed in periacinar fibroblasts (FBs). The other examined markers were negative in human qPSCs. Our data indicate that cytoglobin and adipophilin are markers of qPSCs in the normal human pancreas. However, the use of adipophilin as a qPSC marker may be limited due to its high dependence on optimal PATI

  2. Receptor channel TRPC6 orchestrate the activation of human hepatic stellate cell under hypoxia condition

    Iyer, Soumya C; Kannan, Anbarasu; Gopal, Ashidha; Devaraj, Niranjali; Halagowder, Devaraj

    2015-01-01

    Hepatic stellate cells (HSCs), a specialized stromal cytotype have a great impact on the biological behaviors of liver diseases. Despite this fact, the underlying mechanism that regulates HSC still remains poorly understood. The aim of the present study was to understand the role of TRPC6 signaling in regulating the molecular mechanism of HSCs in response to hypoxia. In the present study we showed that under hypoxia condition, the upregulated Hypoxia Inducible Factor 1α (HIF1α) increases NICD activation, which in turn induces the expression of transient receptor potential channel 6 (TRPC6) in HSC line lx-2. TRPC6 causes a sustained elevation of intracellular calcium which is coupled with the activation of the calcineurin-nuclear factor of activated T-cell (NFAT) pathway which activates the synthesis of extracellular matrix proteins. TRPC6 also activates SMAD2/3 dependent TGF-β signaling in facilitating upregulated expression of αSMA and collagen. As activated HSCs may be a suitable target for HCC therapy and targeting these cells rather than the HCC cells may result in a greater response. Collectively, our studies indicate for the first time the detailed mechanism of activation of HSC through TRPC6 signaling and thus being a promising therapeutic target. - Highlights: • HIF1α increases NICD, induces TRPC6 in lx2 cells. • TRPC6 a novel regulator in the activation of HSC. • HSCs as target for HCC therapy

  3. Receptor channel TRPC6 orchestrate the activation of human hepatic stellate cell under hypoxia condition

    Iyer, Soumya C, E-mail: chidambaram.soumya@gmail.com [Unit of Biochemistry, Department of Zoology, School of Life Sciences, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu (India); Kannan, Anbarasu [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu (India); Gopal, Ashidha [Unit of Biochemistry, Department of Zoology, School of Life Sciences, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu (India); Devaraj, Niranjali [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu (India); Halagowder, Devaraj [Unit of Biochemistry, Department of Zoology, School of Life Sciences, University of Madras, Guindy Campus, Chennai 600025, Tamilnadu (India)

    2015-08-01

    Hepatic stellate cells (HSCs), a specialized stromal cytotype have a great impact on the biological behaviors of liver diseases. Despite this fact, the underlying mechanism that regulates HSC still remains poorly understood. The aim of the present study was to understand the role of TRPC6 signaling in regulating the molecular mechanism of HSCs in response to hypoxia. In the present study we showed that under hypoxia condition, the upregulated Hypoxia Inducible Factor 1α (HIF1α) increases NICD activation, which in turn induces the expression of transient receptor potential channel 6 (TRPC6) in HSC line lx-2. TRPC6 causes a sustained elevation of intracellular calcium which is coupled with the activation of the calcineurin-nuclear factor of activated T-cell (NFAT) pathway which activates the synthesis of extracellular matrix proteins. TRPC6 also activates SMAD2/3 dependent TGF-β signaling in facilitating upregulated expression of αSMA and collagen. As activated HSCs may be a suitable target for HCC therapy and targeting these cells rather than the HCC cells may result in a greater response. Collectively, our studies indicate for the first time the detailed mechanism of activation of HSC through TRPC6 signaling and thus being a promising therapeutic target. - Highlights: • HIF1α increases NICD, induces TRPC6 in lx2 cells. • TRPC6 a novel regulator in the activation of HSC. • HSCs as target for HCC therapy.

  4. Intracellular Glutathione Depletion by Oridonin Leads to Apoptosis in Hepatic Stellate Cells

    Liang-Mou Kuo

    2014-03-01

    Full Text Available Proliferation of hepatic stellate cells (HSCs plays a key role in the pathogenesis of liver fibrosis. Induction of HSC apoptosis by natural products is considered an effective strategy for treating liver fibrosis. Herein, the apoptotic effects of 7,20-epoxy-ent-kaurane (oridonin, a diterpenoid isolated from Rabdosia rubescens, and its underlying mechanisms were investigated in rat HSC cell line, HSC-T6. We found that oridonin inhibited cell viability of HSC-T6 in a concentration-dependent manner. Oridonin induced a reduction in mitochondrial membrane potential and increases in caspase 3 activation, subG1 phase, and DNA fragmentation. These apoptotic effects of oridonin were completely reversed by thiol antioxidants, N-acetylcysteine (NAC and glutathione monoethyl ester. Moreover, oridonin increased production of reactive oxygen species (ROS, which was also inhibited by NAC. Significantly, oridonin reduced intracellular glutathione (GSH level in a concentration- and time-dependent fashion. Additionally, oridonin induced phosphorylations of extracellular signal-regulated kinase (ERK, c-Jun N-terminal kinase (JNK, and p38 mitogen-activated protein kinase (MAPK. NAC prevented the activation of MAPKs in oridonin-induced cells. However, selective inhibitors of MAPKs failed to alter oridonin-induced cell death. In summary, these results demonstrate that induction of apoptosis in HSC-T6 by oridonin is associated with a decrease in cellular GSH level and increase in ROS production.

  5. Activated rat hepatic stellate cells influence Th1/Th2 profile in vitro.

    Xing, Zhi-Zhi; Huang, Liu-Ye; Wu, Cheng-Rong; You, Hong; Ma, Hong; Jia, Ji-Dong

    2015-06-21

    To investigate the effects of activated rat hepatic stellate cells (HSCs) on rat Th1/Th2 profile in vitro. Growth and survival of activated HSCs and CD4(+) T lymphocytes cultured alone or together was assessed after 24 or 48 h. CD4(+) T lymphocytes were then cultured with or without activated HSCs for 24 or 48 h and the proportion of Th1 [interferon (IFN)-γ(+)] and Th2 [interleukin (IL)-4(+)] cells was assessed by flow cytometry. Th1 and Th2 cell apoptosis was assessed after 24 h of co-culture using a caspase-3 staining procedure. Differentiation rates of Th1 and Th2 cells from CD4(+) T lymphocytes that were positive for CD25 but did not express IFN-γ or IL-4 were also assessed after 48 h of co-culture with activated HSCs. Galectin-9 expression in HSCs was determined by immunofluorescence and Western blotting. ELISA was performed to assess galectin-9 secretion from activated HSCs. Co-culture of CD4(+) T lymphocytes with activated rat HSCs for 48 h significantly reduced the proportion of Th1 cells compared to culture-alone conditions (-1.73% ± 0.71%; P Th1/Th2 ratio was significantly decreased (-0.44 ± 0.13; P Th1 cells was decreased (-65.71 ± 9.67; P Th1 (12.27% ± 0.99%; P Th1 cell apoptosis rate was significantly higher than in Th2 cells (P Th1 and Th2 cells; however, the increase in the proportion of Th2 cells was significantly higher than that of Th1 cells (1.85% ± 0.48%; P Th1/Th2 profile, inhibiting the Th1 response and enhancing the Th2 response, and this may be a novel pathway for liver fibrogenesis.

  6. Effects of stellate ganglion block on cardiovascular reaction and heart rate variability in elderly patients during anesthesia induction and endotracheal intubation.

    Chen, Yong-Quan; Jin, Xiao-Ju; Liu, Zhao-Fang; Zhu, Mei-Fang

    2015-03-01

    To investigate the effects of stellate ganglion block (SGB) on cardiovascular response and heart rate (HR) variability in elderly patients during anesthesia induction and endotracheal intubation. A randomized, double-blinded, and placebo-controlled study. University-affiliated teaching hospital. Eighty elderly patients (American Society of Anesthesiologists grades I and II) receiving elective surgery during general anesthesia. Right stellate ganglion injection (SGB) was performed in all patients using 10 mL of 1% lidocaine or normal saline. Systolic blood pressure (BP), diastolic BP, HR, and calculated rate pressure product. HR variability at the following time points: conscious status before induction (T0); immediately before intubation (T1); immediately after intubation (T2); and 1, 3, and 5 minutes postintubation (T3, T4, and T5). No significant differences in BP and HR were observed between the 2 groups. Rate pressure product values significantly increased in the control group compared with baseline and SGB group values. Low-frequency power (LF) and LF/high-frequency power (HF) significantly increased, and HF and normalized units of HF significantly decreased in the control group compared with baseline values. LF, normalized units of LF, and LF/HF in the SGB group significantly decreased compared with those of the control group. SGB protects the myocardium and effectively suppresses stress responses during anesthesia induction and tracheal intubation in elderly patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

    Soeda, Junpei; Morgan, Maelle; McKee, Chad; Mouralidarane, Angelina; Lin, ChingI [University College London, Centre for Hepatology, Royal Free Hospital, London NW3 2PF (United Kingdom); Roskams, Tania [Department of Morphology and Molecular Pathology, University of Leuven (Belgium); Oben, Jude A., E-mail: j.oben@ucl.ac.uk [University College London, Centre for Hepatology, Royal Free Hospital, London NW3 2PF (United Kingdom); Department of Gastroenterology and Hepatology, Guy' s and St Thomas' Hospital, London SE1 7EH (United Kingdom)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Cigarette smoke may induce liver fibrosis via nicotine receptors. Black-Right-Pointing-Pointer Nicotine induces proliferation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Nicotine activates hepatic fibrogenic pathways. Black-Right-Pointing-Pointer Nicotine receptor antagonists attenuate HSC proliferation. Black-Right-Pointing-Pointer Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine - which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells in the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed - RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-{alpha}2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-{beta}1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type ({alpha}1, {beta}1, delta and epsilon) and neuronal type ({alpha}3, {alpha}6, {alpha}7, {beta}2 and {beta}4) nAChR subunits at the mRNA level. Among these subunits, {alpha}3, {alpha}7, {beta}1 and {epsilon} were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-{alpha}2 and TGF-{beta}1 mRNA expression were significantly upregulated by nicotine and inhibited by

  8. Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

    Soeda, Junpei; Morgan, Maelle; McKee, Chad; Mouralidarane, Angelina; Lin, ChingI; Roskams, Tania; Oben, Jude A.

    2012-01-01

    Highlights: ► Cigarette smoke may induce liver fibrosis via nicotine receptors. ► Nicotine induces proliferation of hepatic stellate cells (HSCs). ► Nicotine activates hepatic fibrogenic pathways. ► Nicotine receptor antagonists attenuate HSC proliferation. ► Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine – which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells in the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed – RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-α2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-β1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type (α1, β1, delta and epsilon) and neuronal type (α3, α6, α7, β2 and β4) nAChR subunits at the mRNA level. Among these subunits, α3, α7, β1 and ε were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-α2 and TGF-β1 mRNA expression were significantly upregulated by nicotine and inhibited by mecamylamine. α1 and α3-nAChR mRNA expression was significantly upregulated in NASH fibrosis compared to normal livers. Conclusion: Nicotine at levels in smokers’ blood is pro-fibrogenic, through

  9. Copper ions stimulate the proliferation of hepatic stellate cells via oxygen stress in vitro.

    Xu, San-qing; Zhu, Hui-yun; Lin, Jian-guo; Su, Tang-feng; Liu, Yan; Luo, Xiao-ping

    2013-02-01

    This study examined the effect of copper ions on the proliferation of hepatic stellate cells (HSCs) and the role of oxidative stress in this process in order to gain insight into the mechanism of hepatic fibrosis in Wilson's disease. LX-2 cells, a cell line of human HSCs, were cultured in vitro and treated with different agents including copper sulfate, N-acetyl cysteine (NAC) and buthionine sulfoximine (BSO) for different time. The proliferation of LX-2 cells was measured by non-radioactive cell proliferation assay. Real-time PCR and Western blotting were used to detect the mRNA and protein expression of platelet-derived growth factor receptor β subunit (PDGFβR), ELISA to determine the level of glutathione (GSH) and oxidized glutathione (GSSG), dichlorofluorescein assay to measure the level of reactive oxygen species (ROS), and lipid hydroperoxide assay to quantify the level of lipid peroxide (LPO). The results showed that copper sulfate over a certain concentration range could promote the proliferation of LX-2 cells in a time- and dose-dependent manner. The effect was most manifest when LX-2 cells were treated with copper sulfate at a concentration of 100 μmol/L for 24 h. Additionally, copper sulfate could dose-dependently increase the levels of ROS and LPO, and decrease the ratio of GSH/GSSG in LX-2 cells. The copper-induced increase in mRNA and protein expression of PDGFβR was significantly inhibited in LX-2 cells pre-treated with NAC, a precursor of GSH, and this phenomenon could be reversed by the intervention of BSO, an inhibitor of NAC. It was concluded that copper ions may directly stimulate the proliferation of HSCs via oxidative stress. Anti-oxidative stress therapies may help suppress the copper-induced activation and proliferation of HSCs.

  10. Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells

    Genz, Berit [Institute for Experimental Surgery, Rostock University Medical Center, Rostock (Germany); Thomas, Maria [Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart (Germany); Pützer, Brigitte M. [Institute of Experimental Gene Therapy and Cancer Research, Rostock University Medical Center, Rostock (Germany); Siatkowski, Marcin; Fuellen, Georg [Institute for Biostatistics and Informatics in Medicine and Ageing Research, Rostock University Medical Center, Rostock (Germany); Vollmar, Brigitte [Institute for Experimental Surgery, Rostock University Medical Center, Rostock (Germany); Abshagen, Kerstin, E-mail: kerstin.abshagen@uni-rostock.de [Institute for Experimental Surgery, Rostock University Medical Center, Rostock (Germany)

    2014-11-01

    Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluated an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. - Highlights: • We performed adenoviral overexpression of Lhx2 in primary hepatic stellate cells. • Hepatic stellate cells expressed stem cell markers during cultivation. • Cell migration and contractility was slightly hampered upon Lhx2 overexpression. • Lhx2 overexpression did not affect stem cell character of hepatic stellate cells.

  11. Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells

    Genz, Berit; Thomas, Maria; Pützer, Brigitte M.; Siatkowski, Marcin; Fuellen, Georg; Vollmar, Brigitte; Abshagen, Kerstin

    2014-01-01

    Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluated an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. - Highlights: • We performed adenoviral overexpression of Lhx2 in primary hepatic stellate cells. • Hepatic stellate cells expressed stem cell markers during cultivation. • Cell migration and contractility was slightly hampered upon Lhx2 overexpression. • Lhx2 overexpression did not affect stem cell character of hepatic stellate cells

  12. Pancreatic cancer stimulates pancreatic stellate cell proliferation and TIMP-1 production through the MAP kinase pathway

    Yoshida, Seiya; Yokota, Tokuyasu; Ujiki, Michael; Ding Xianzhong; Pelham, Carolyn; Adrian, Thomas E.; Talamonti, Mark S.; Bell, Richard H.; Denham, Woody

    2004-01-01

    Pancreatic adenocarcinoma is characterized by an intense desmoplastic reaction that surrounds the tumor. Pancreatic stellate cells (PSCs) are thought to be responsible for production of this extracellular matrix. When activated, PSCs have a myofibroblast phenotype and produce not only components of the extracellular matrix including collagen, fibronectin, and laminin, but also matrix metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs). Since PSCs are found in the stroma surrounding human pancreatic adenocarcinoma, we postulate that pancreatic cancer could impact PSC proliferation and TIMP-1 production. Rat PSCs were isolated and cultured. Isolated PSCs were exposed to PANC-1 conditioned medium (CM) and proliferation, activation of the mitogen-activated protein (MAP) kinase pathway, and TIMP-1 gene induction were determined. Exposure to PANC-1 CM increased PSC DNA synthesis, cell number, and TIMP-1 mRNA (real-time PCR) as well as activating the extracellular-regulated kinase (ERK) 1/2. Inhibition of ERK 1/2 phosphorylation (U0126) prevented the increases in growth and TIMP-1 expression. PANC-1 CM stimulates PSC proliferation and TIMP-1 through the MAP kinase (ERK 1/2) pathway

  13. Estradiol inhibits hepatic stellate cell area and collagen synthesis in the chicken liver.

    Nishimura, Shotaro; Teshima, Akifumi; Kawabata, Fuminori; Tabata, Shoji

    2017-11-01

    Hepatic stellate cells (HSCs) are the main collagen-producing cells in the liver. The HSC area and amount of collagen fibers are different between male and female chickens. This study was performed to confirm the effect of estradiol on collagen synthesis in the growing chicken liver. Blood estradiol levels in chicks were compared at 4 and 8 weeks of age, and the collagen fibril network in liver tissue was observed at 8 weeks by scanning electron microscopy. Intraperitoneal administrations of estradiol and tamoxifen to male and female chicks, respectively, were performed daily from 5 to 8 weeks of age. The areas of HSCs and collagen contents were measured in the liver tissue. The blood estradiol level was higher in females than in males, and the collagen fibril network was denser in males than in females at 8 weeks of age. Estradiol administration in males induced decreases in the HSC area and collagen content of the liver. Conversely, tamoxifen administration in females induced an increase in the HSC area but did not facilitate collagen synthesis. Based on these results, estradiol inhibits the area and collagen synthesis of HSCs in the growing chicken liver under normal physiological conditions. © 2017 Japanese Society of Animal Science.

  14. Inhibitory Effects of Ecklonia cava Extract on High Glucose-Induced Hepatic Stellate Cell Activation

    Akiko Kojima-Yuasa

    2011-12-01

    Full Text Available Nonalcoholic steatohepatitis (NASH is a disease closely associated with obesity and diabetes. A prevalence of type 2 diabetes and a high body mass index in cryptogenic cirrhosis may imply that obesity leads to cirrhosis. Here, we examined the effects of an extract of Ecklonia cava, a brown algae, on the activation of high glucose-induced hepatic stellate cells (HSCs, key players in hepatic fibrosis. Isolated HSCs were incubated with or without a high glucose concentration. Ecklonia cava extract (ECE was added to the culture simultaneously with the high glucose. Treatment with high glucose stimulated expression of type I collagen and α-smooth muscle actin, which are markers of activation in HSCs, in a dose-dependent manner. The activation of high glucose-treated HSCs was suppressed by the ECE. An increase in the formation of intracellular reactive oxygen species (ROS and a decrease in intracellular glutathione levels were observed soon after treatment with high glucose, and these changes were suppressed by the simultaneous addition of ECE. High glucose levels stimulated the secretion of bioactive transforming growth factor-β (TGF-β from the cells, and the stimulation was also suppressed by treating the HSCs with ECE. These results suggest that the suppression of high glucose-induced HSC activation by ECE is mediated through the inhibition of ROS and/or GSH and the downregulation of TGF-β secretion. ECE is useful for preventing the development of diabetic liver fibrosis.

  15. Pancreatic Stellate Cells : A Starring Role in Normal and Diseased Pancreas

    Minoti eApte

    2012-08-01

    Full Text Available While the morphology and function of cells of the exocrine and endocrine pancreas have been studied over several centuries, one important cell type in the gland, the pancreatic stellate cell (PSC, had remained undiscovered until as recently as twenty years ago. Even after its first description in 1982, it was to be another 16 years before its biology could begin to be studied, because it was only in 1998 that methods were developed to isolate and culture PSCs from rodent and human pancreas. PSCs are now known to play a critical role in pancreatic fibrosis, a consistent histological feature of two major diseases of the pancreas - chronic pancreatitis and pancreatic cancer. In health, PSCs maintain normal tissue architecture via regulation of the synthesis and degradation of extracellular matrix (ECM proteins. Recent studies have also implied other additional functions for PSCs as progenitor cells, immune cells or intermediaries in exocrine pancreatic secretion in humans.During pancreatic injury, PSCs transform from their quiescent phase into an activated, myofibroblast-like phenotype that secretes excessive amounts of ECM proteins leading to the fibrosis of chronic pancreatitis and pancreatic cancer. An ever increasing number of factors that stimulate and/or inhibit PSC activation via paracrine and autocrine pathways are being identified and characterized. It is also now established that PSCs interact closely with pancreatic cancer cells to facilitate cancer progression. Based on these findings, several therapeutic strategies have been examined in experimental models of chronic pancreatitis as well as pancreatic cancer, in a bid to inhibit/retard PSC activation and thereby alleviate chronic pancreatitis or reduce tumour growth in pancreatic cancer. The challenge that remains is to translate these pre-clinical developments into clinically applicable treatments for patients with chronic pancreatitis and pancreatic cancer.

  16. Activated effects of parathyroid hormone-related protein on human hepatic stellate cells.

    Fen-Fen Liang

    Full Text Available BACKGROUND & AIMS: After years of experiments and clinical studies, parathyroid hormone-related protein(PTHrP has been shown to be a bone formation promoter that elicits rapid effects with limited adverse reaction. Recently, PTHrP was reported to promote fibrosis in rat kidney in conjunction with transforming growth factor-beta1 (TGF-β1, which is also a fibrosis promoter in liver. However, the effect of PTHrP in liver has not been determined. In this study, the promoting actions of PTHrP were first investigated in human normal hepatic stellate cells (HSC and LX-2 cell lines. METHODS: TGF-β1, alpha-smooth muscle actin (α-SMA, matrix metalloproteinase 2 (MMP-2, and collagen I mRNA were quantified by real-time polymerase chain reaction (PCR after HSCs or LX-2 cells were treated with PTHrP(1-36 or TGF-β1. Protein levels were also assessed by western-blot analysis. Alpha-SMA were also detected by immunofluorescence, and TGF-β1 secretion was measured with enzyme-linked immunosorbent assay (ELISA of HSC cell culture media. RESULTS: In cultured human HSCs, mRNA and protein levels of α-SMA, collagen I, MMP-2, and TGF-β1 were increased by PTHrP treatment. A similar increasing pattern was also observed in LX-2 cells. Moreover, PTHrP significantly increased TGF-β1 secretion in cultured media from HSCs. CONCLUSIONS: PTHrP activated HSCs and promoted the fibrosis process in LX-2 cells. These procedures were probably mediated via TGF-β1, highlighting the potential effects of PTHrP in the liver.

  17. Hypoxia enhances the interaction between pancreatic stellate cells and cancer cells via increased secretion of connective tissue growth factor.

    Eguchi, Daiki; Ikenaga, Naoki; Ohuchida, Kenoki; Kozono, Shingo; Cui, Lin; Fujiwara, Kenji; Fujino, Minoru; Ohtsuka, Takao; Mizumoto, Kazuhiro; Tanaka, Masao

    2013-05-01

    Pancreatic cancer (PC), a hypovascular tumor, thrives under hypoxic conditions. Pancreatic stellate cells (PSCs) promote PC progression by secreting soluble factors, but their functions in hypoxia are poorly understood. This study aimed to clarify the effects of hypoxic conditions on the interaction between PC cells and PSCs. We isolated human PSCs from fresh pancreatic ductal adenocarcinomas and analyzed functional differences in PSCs between normoxia (21% O2) and hypoxia (1% O2), including expression of various factors related to tumor-stromal interactions. We particularly analyzed effects on PC invasiveness of an overexpressed molecule-connective tissue growth factor (CTGF)-in PSCs under hypoxic conditions, using RNA interference techniques. Conditioned media from hypoxic PSCs enhanced PC cell invasiveness more intensely than that from normoxic PSCs (P cancer. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. PTP1B confers liver fibrosis by regulating the activation of hepatic stellate cells

    Chen, Pei-Jie; Cai, Shuang-Peng; Yang, Yang; Li, Wan-Xia; Huang, Cheng; Meng, Xiao-Ming; Li, Jun, E-mail: lj@ahmu.edu.cn

    2016-02-01

    Liver fibrosis is a reversible wound-healing response to chronic hepatic injuries. Activation of hepatic stellate cells (HSCs) plays a pivotal role in the development of hepatic fibrosis. The currently accepted mechanism for the resolution of liver fibrosis is the apoptosis and inactivation of activated HSCs. Protein tyrosine phosphatase 1B (PTP1B), a prototype of non-receptor protein tyrosine phosphatase, is proved to be a vital modulator in cardiac fibrogenesis. However, the precise role of PTP1B on liver fibrosis and HSC activation is still unclear. Our study showed that the expression of PTP1B was elevated in fibrotic liver but reduced after spontaneous recovery. Moreover, stimulation of HSC-T6 cells with transforming growth factor-β1 (TGF-β1) resulted in a dose/time-dependent increase of PTP1B mRNA and protein. Co-incubation of HSC-T6 cells with PTP1B-siRNA inhibited the cell proliferation and activation induced by TGF-β1. Additionally, both mRNA and protein of PTP1B were dramatically decreased in inactivated HSCs after treated with adipogenic differentiation mixture (MDI). Over-expression of PTP1B hindered the inactivation of HSC-T6 cells induced by MDI. These observations revealed a regulatory role of PTP1B in liver fibrosis and implied PTP1B as a potential therapeutic target. - Highlights: • The expression of PTP1B in the fibrotic livers and recovery livers • The expression of PTP1B in activated and inactivated HSCs • Blockade of PTP1B inhibited the TGF-β1-induced proliferation and activation of HSCs. • Over-expression of PTP1B abolished the inactivation of HSCs induced by MDI.

  19. PTP1B confers liver fibrosis by regulating the activation of hepatic stellate cells

    Chen, Pei-Jie; Cai, Shuang-Peng; Yang, Yang; Li, Wan-Xia; Huang, Cheng; Meng, Xiao-Ming; Li, Jun

    2016-01-01

    Liver fibrosis is a reversible wound-healing response to chronic hepatic injuries. Activation of hepatic stellate cells (HSCs) plays a pivotal role in the development of hepatic fibrosis. The currently accepted mechanism for the resolution of liver fibrosis is the apoptosis and inactivation of activated HSCs. Protein tyrosine phosphatase 1B (PTP1B), a prototype of non-receptor protein tyrosine phosphatase, is proved to be a vital modulator in cardiac fibrogenesis. However, the precise role of PTP1B on liver fibrosis and HSC activation is still unclear. Our study showed that the expression of PTP1B was elevated in fibrotic liver but reduced after spontaneous recovery. Moreover, stimulation of HSC-T6 cells with transforming growth factor-β1 (TGF-β1) resulted in a dose/time-dependent increase of PTP1B mRNA and protein. Co-incubation of HSC-T6 cells with PTP1B-siRNA inhibited the cell proliferation and activation induced by TGF-β1. Additionally, both mRNA and protein of PTP1B were dramatically decreased in inactivated HSCs after treated with adipogenic differentiation mixture (MDI). Over-expression of PTP1B hindered the inactivation of HSC-T6 cells induced by MDI. These observations revealed a regulatory role of PTP1B in liver fibrosis and implied PTP1B as a potential therapeutic target. - Highlights: • The expression of PTP1B in the fibrotic livers and recovery livers • The expression of PTP1B in activated and inactivated HSCs • Blockade of PTP1B inhibited the TGF-β1-induced proliferation and activation of HSCs. • Over-expression of PTP1B abolished the inactivation of HSCs induced by MDI.

  20. Effect of shear stress on the migration of hepatic stellate cells.

    Sera, Toshihiro; Sumii, Tateki; Fujita, Ryosuke; Kudo, Susumu

    2018-01-01

    When the liver is damaged, hepatic stellate cells (HSCs) can change into an activated, highly migratory state. The migration of HSCs may be affected by shear stress due not only to sinusoidal flow but also by the flow in the space of Disse because this space is filled with blood plasma. In this study, we evaluated the effects of shear stress on HSC migration in a scratch-wound assay with a parallel flow chamber. At regions upstream of the wound area, the migration was inhibited by 0.6 Pa and promoted by 2.0 Pa shear stress, compared to the static condition. The platelet-derived growth factor (PDGF)-BB receptor, PDGFR-β, was expressed in all conditions and the differences were not significant. PDGF increased HSC migration, except at 0.6 Pa shear stress, which was still inhibited. These results indicate that another molecular factor, such as PDGFR-α, may act to inhibit the migration under low shear stress. At regions downstream of the wound area, the migration was smaller under shear stress than under the static condition, although the expression of PDGFR-β was significantly higher. In particular, the migration direction was opposite to the wound area under high shear stress; therefore, migration might be influenced by the intercellular environment. Our results indicate that HSC migration was influenced by shear stress intensity and the intercellular environment.

  1. Serotonin Activated Hepatic Stellate Cells Contribute to Sex Disparity in Hepatocellular CarcinomaSummary

    Qiqi Yang

    2017-05-01

    Full Text Available Background & Aims: Hepatocellular carcinoma (HCC occurs more frequently and aggressively in men than in women. Although sex hormones are believed to play a critical role in this disparity, the possible contribution of other factors largely is unknown. We aimed to investigate the role of serotonin on its contribution of sex discrepancy during HCC. Methods: By using an inducible zebrafish HCC model through hepatocyte-specific transgenic krasV12 expression, differential rates of HCC in male and female fish were characterized by both pharmaceutical and genetic interventions. The findings were validated further in human liver disease samples. Results: Accelerated HCC progression was observed in krasV12-expressing male zebrafish and male fish liver tumors were found to have higher hepatic stellate cell (HSC density and activation. Serotonin, which is essential for HSC survival and activation, similarly were found to be synthesized and accumulated more robustly in males than in females. Serotonin-activated HSCs could promote HCC carcinogenesis and concurrently increase serotonin synthesis via transforming growth factor (Tgfb1 expression, hence contributing to sex disparity in HCC. Analysis of liver disease patient samples showed similar male predominant serotonin accumulation and Tgfb1 expression. Conclusions: In both zebrafish HCC models and human liver disease samples, a predominant serotonin synthesis and accumulation in males resulted in higher HSC density and activation as well as Tgfb1 expression, thus accelerating HCC carcinogenesis in males. Keywords: Liver Cancer, TGFB1, Kras, Zebrafish

  2. Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

    Zan, Yanlu [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Yuxia, E-mail: yzhang@wehi.edu.au [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China); Tien, Po, E-mail: tienpo@sun.im.ac.cn [Center for Molecular Virology, CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101 (China)

    2013-06-07

    Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs.

  3. Hepatitis B virus e antigen induces activation of rat hepatic stellate cells

    Zan, Yanlu; Zhang, Yuxia; Tien, Po

    2013-01-01

    Highlights: •HBeAg expression in HSCs induced production of ECM protein and liver fibrotic markers. •The activation and proliferation of HSCs were mediated by TGF-β. •HBeAg protein purified from cell medium directly activated HSCs. -- Abstract: Chronic hepatitis B virus infection is a major cause of hepatic fibrosis, leading to liver cirrhosis and hepatocellular carcinoma. Hepatitis B virus e antigen (HBeAg) is an accessory protein of HBV, not required for viral replication but important for natural infection in vivo. Hepatic stellate cells (HSCs) are the major producers of excessive extracellular matrix during liver fibrogenesis. Therefore, we examined the influence of HBeAg on HSCs. The rat HSC line HSC-T6 was transfected with HBeAg plasmids, and expression of α-smooth muscle actin, collagen I, transforming growth factor-β1 (TGF-β), and tissue inhibitors of metalloproteinase 1 (TIMP-1) was investigated by quantitative real-time PCR. The proliferation of HSCs was determined by MTS analysis. HBeAg transduction induced up-regulation of these fibrogenic genes and proliferation of HSCs. We found that HBeAg induced TGF-β secretion in HSCs, and the activation of HSCs was prevented by a neutralizing anti-TGF-β antibody. Depletion and addition of HBeAg protein in conditioned medium from HSC-T6 cells transduced with HBeAg indicated that HBeAg directly induced the activation and proliferation of rat primary HSCs. Taken together, HBeAg induces the activation and proliferation of HSCs, mainly mediated by TGF-β, and HBeAg protein purified from cell medium can directly activate HSCs

  4. Control of clustered action potential firing in a mathematical model of entorhinal cortex stellate cells.

    Tait, Luke; Wedgwood, Kyle; Tsaneva-Atanasova, Krasimira; Brown, Jon T; Goodfellow, Marc

    2018-07-14

    The entorhinal cortex is a crucial component of our memory and spatial navigation systems and is one of the first areas to be affected in dementias featuring tau pathology, such as Alzheimer's disease and frontotemporal dementia. Electrophysiological recordings from principle cells of medial entorhinal cortex (layer II stellate cells, mEC-SCs) demonstrate a number of key identifying properties including subthreshold oscillations in the theta (4-12 Hz) range and clustered action potential firing. These single cell properties are correlated with network activity such as grid firing and coupling between theta and gamma rhythms, suggesting they are important for spatial memory. As such, experimental models of dementia have revealed disruption of organised dorsoventral gradients in clustered action potential firing. To better understand the mechanisms underpinning these different dynamics, we study a conductance based model of mEC-SCs. We demonstrate that the model, driven by extrinsic noise, can capture quantitative differences in clustered action potential firing patterns recorded from experimental models of tau pathology and healthy animals. The differential equation formulation of our model allows us to perform numerical bifurcation analyses in order to uncover the dynamic mechanisms underlying these patterns. We show that clustered dynamics can be understood as subcritical Hopf/homoclinic bursting in a fast-slow system where the slow sub-system is governed by activation of the persistent sodium current and inactivation of the slow A-type potassium current. In the full system, we demonstrate that clustered firing arises via flip bifurcations as conductance parameters are varied. Our model analyses confirm the experimentally suggested hypothesis that the breakdown of clustered dynamics in disease occurs via increases in AHP conductance. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. [125I]Bolton-Hunter neuropeptide-Y-binding sites on folliculo-stellate cells of the pars intermedia of Xenopus laevis: A combined autoradiographic and immunocytochemical study

    De Rijk, E.P.; Cruijsen, P.M.; Jenks, B.G.; Roubos, E.W.

    1991-01-01

    It has previously been established that neuropeptide-Y (NPY) is a potent inhibitor of alpha MSH release from the pars intermedia of the amphibian Xenopus laevis. The location of binding sites for NPY in the pars intermedia of the pituitary has now been studied with light microscopic autoradiography, using a dispersed cell labeling method with the specific NPY receptor ligand [ 125 I]Bolton-Hunter NPY. The majority of radioactive labeling was associated with folliculo-stellate cells; the percentage of labeling as well as the mean number of grains were approximately 5 times higher for folliculo-stellate cells than for melanotropes. An excess of nonlabeled NPY drastically reduced radiolabeling of folliculo-stellate cells, but had no effect on the degree of labeling of melanotropes. These results show that folliculo-stellate cells of X. laevis possess specific binding sites for NPY and indicate that NPY exerts its inhibitory action on the release of alpha MSH in an indirect fashion, by acting on the folliculo-stellate cells

  6. Ultrasound-guided stellate ganglion blocks combined with pharmacological and occupational therapy in Complex Regional Pain Syndrome (CRPS): a pilot case series ad interim.

    Wei, Karin; Feldmann, Robert E; Brascher, Anne-Kathrin; Benrath, Justus

    2014-12-01

    This preliminary and retrospective pilot case series examines a treatment concept consisting of ultrasound-guided stellate ganglion blocks (SGBs) combined with pharmacological and occupational therapy in patients with complex regional pain syndrome (CRPS) of the hand. Efficacy of combined treatment concepts and safety of ultrasound-guided SGB have not been sufficiently investigated yet. A total number of 156 blocks were evaluated in 16 patients with CRPS in a retrospective analysis. All patients received pharmacotherapy and a standard regimen of occupational therapy offered simultaneously to the SGBs. Changes in both spontaneous and evoked pain levels were assessed by numerical pain rating score before and after the last blockade of a series. Side effects were documented. The overall mean pain reduction was 63.2% regarding spontaneous and 45.3% regarding evoked pain. Mild complications, such as hoarseness or dysphagia, occurred in 13.5% of the blocks (21 SGBs). Serious complications, such as plexus paresis or accidental puncture of vessels or other structures, did not occur. Time between symptom onset and start of treatment did not affect the extent of pain reduction. The combination of ultrasound-guided SGB and simultaneous pharmacological and occupational therapy showed encouraging treatment results under conditions of this pilot case series. Assessment of efficacy of this combined treatment concept and safety of ultrasound-guided SGB require further prospective clinical studies with larger number of participants. Wiley Periodicals, Inc.

  7. Conditionally immortalized human pancreatic stellate cell lines demonstrate enhanced proliferation and migration in response to IGF-I

    Rosendahl, Ann H., E-mail: ann.rosendahl@med.lu.se [Lund University, Department of Clinical Sciences Lund, Division of Surgery, Lund (Sweden); Lund University and Skåne University Hospital, Department of Clinical Sciences Lund, Division of Oncology and Pathology, Lund (Sweden); Gundewar, Chinmay; Said Hilmersson, Katarzyna [Lund University, Department of Clinical Sciences Lund, Division of Surgery, Lund (Sweden); Ni, Lan; Saleem, Moin A. [University of Bristol, School of Clinical Sciences, Children' s Renal Unit and Academic Renal Unit, Bristol (United Kingdom); Andersson, Roland [Lund University, Department of Clinical Sciences Lund, Division of Surgery, Lund (Sweden)

    2015-01-15

    Pancreatic stellate cells (PSCs) play a key role in the dense desmoplastic stroma associated with pancreatic ductal adenocarcinoma. Studies on human PSCs have been minimal due to difficulty in maintaining primary PSC in culture. We have generated the first conditionally immortalized human non-tumor (NPSC) and tumor-derived (TPSC) pancreatic stellate cells via transformation with the temperature-sensitive SV40 large T antigen and human telomerase (hTERT). These cells proliferate at 33°C. After transfer to 37°C, the SV40LT is switched off and the cells regain their primary PSC phenotype and growth characteristics. NPSC contained cytoplasmic vitamin A-storing lipid droplets, while both NPSC and TPSC expressed the characteristic markers αSMA, vimentin, desmin and GFAP. Proteome array analysis revealed that of the 55 evaluated proteins, 27 (49%) were upregulated ≥3-fold in TPSC compared to NPSC, including uPA, pentraxin-3, endoglin and endothelin-1. Two insulin-like growth factor binding proteins (IGFBPs) were inversely expressed. Although discordant IGFBP-2 and IGFBP-3 levels, IGF-I was found to stimulate proliferation of both NPSC and TPSC. Both basal and IGF-I stimulated motility was significantly enhanced in TPSC compared to NPSC. In conclusion, these cells provide a unique resource that will facilitate further study of the active stroma compartment associated with pancreatic cancer. - Highlights: • Generation of human conditionally immortalized human pancreatic stellate cell lines. • Temperature-sensitive SV40LT allows switch to primary PSC phenotype characteristics. • Proteome profiling revealed distinct expression patterns between TPSC and NPSC. • Enhanced IGF-I-stimulated proliferation and motility by TPSC compared to NPSC.

  8. TSA increases C/EBP‑α expression by increasing its lysine acetylation in hepatic stellate cells.

    Tao, Li-Li; Ding, Di; Yin, Wei-Hua; Peng, Ji-Ying; Hou, Chen-Jian; Liu, Xiu-Ping; Chen, Yao-Li

    2017-11-01

    CCAAT enhancer binding protein‑α (C/EBP‑α) is a transcription factor expressed only in certain tissues, including the liver. It has been previously demonstrated that C/EBP‑α may induce apoptosis in hepatic stellate cells (HSCs), raising the question of whether acetylation of C/EBP‑α is associated with HSCs, and the potential associated mechanism. A total of three histone deacetylase inhibitors (HDACIs), including trichostatin A (TSA), suberoylanilide hydroxamic acid and nicotinamide, were selected to determine whether acetylation affects C/EBP‑α expression. A Cell Counting Kit‑8 assay was used to determine the rate of proliferation inhibition following treatment with varying doses of the three HDACIs in HSC‑T6 and BRL‑3A cells. Western blot analysis was used to examine Caspase‑3, ‑8, ‑9, and ‑12 levels in HSC‑T6 cells treated with adenoviral‑C/EBP‑α and/or TSA. Following treatment with TSA, a combination of reverse transcription‑quantitative polymerase chain reaction and western blot analyses was used to determine the inherent C/EBP‑α mRNA and protein levels in HSC‑T6 cells at 0, 1, 2, 4, 8, 12, 24, 36 and 48 h. Nuclear and cytoplasmic proteins were extracted to examine C/EBP‑α distribution. Co‑immunoprecipitation analysis was used to examine the lysine acetylation of C/EBP‑α. It was observed that TSA inhibited the proliferation of HSC‑T6 cells to a greater extent compared with BRL‑3A cells, following treatment with the three HDACIs. TSA induced apoptosis in HSC‑T6 cells and enhanced the expression of C/EBP‑α. Following treatment of HSC‑T6 cells with TSA, inherent C/EBP‑α expression increased in a time‑dependent manner, and its lysine acetylation simultaneously increased. Therefore, the results of the present study suggested that TSA may increase C/EBP‑α expression by increasing its lysine acetylation in HSCs.

  9. JNK1 induces hedgehog signaling from stellate cells to accelerate liver regeneration in mice.

    Langiewicz, Magda; Graf, Rolf; Humar, Bostjan; Clavien, Pierre A

    2018-04-27

    To improve outcomes of two-staged hepatectomies for large/multiple liver tumors, portal vein ligation (PVL) has been combined with parenchymal transection (coined ALPPS; Associated Liver Partition and Portal vein ligation for Staged hepatectomy) to greatly accelerate liver regeneration. In a novel ALPPS mouse model, we have reported paracrine Indian hedgehog (IHH) signaling from stellate cells as an early contributor to augmented regeneration. Here, we sought to identify upstream regulators of IHH. ALPPS in mice was compared against PVL and additional control surgeries. Potential IHH regulators were identified through in silico mining of transcriptomic data. JNK1 activity was reduced through SP600125 to evaluate its effects on IHH signaling. Recombinant IHH was injected after JNK diminution to substantiate their relationship during accelerated liver regeneration. Mining linked Ihh to Mapk8. JNK1 upregulation after ALPPS was validated and preceded the IHH peak. On immunofluorescence, JNK1 and IHH co-localized in ASMA-positive non-parenchymal cells. Inhibition of JNK1 prior to ALPPS surgery reduced liver weight gain to PVL levels and was accompanied by downregulation of hepatocellular proliferation and the IHH-GLI1-CCND1 axis. In JNK1-inhibited mice, recombinant IHH restored ALPPS-like acceleration of regeneration and re-elevated JNK1 activity, suggesting the presence of a positive IHH-JNK1 feedback loop. JNK1-mediated induction of IHH paracrine signaling from HSCs is essential for accelerated regeneration of parenchymal mass. The JNK1-IHH axis is a mechanism unique to ALPPS surgery and may point to therapeutic alternatives for patients with insufficient regenerative capacity. ALPPS, a novel two-staged hepatectomy, induces an unprecedented acceleration of liver regeneration to enable treatment of unresectable liver tumors. Here, we demonstrate JNK1-IHH signaling as a mechanism underlying the regenerative acceleration induced by ALPPS. Copyright © 2018 European

  10. The improving effects on hepatic fibrosis of interferon-γ liposomes targeted to hepatic stellate cells

    Li, Qinghua; Yan, Zhiqiang; Li, Feng; Lu, Weiyue; Wang, Jiyao; Guo, Chuanyong

    2012-07-01

    No satisfactory anti-fibrotic therapies have yet been applied clinically. One of the main reasons is the inability to specifically target the responsible cells to produce an available drug concentration and the side-effects. Exploiting the key role of the activated hepatic stellate cells (HSCs) in both hepatic fibrogenesis and over-expression of platelet-derived growth factor receptor-β (PDGFR-β), we constructed targeted sterically stable liposomes (SSLs) modified by a cyclic peptide (pPB) with affinity for the PDGFR-β to deliver interferon (IFN)-γ to HSCs. The pPB-SSL-IFN-γ showed satisfactory size distribution. In vitro pPB-SSL could be taken up by activated HSCs. The study of tissue distribution via living-body animal imaging showed that the pPB-SSL-IFN-γ mostly accumulated in the liver until 24 h. Furthermore, the pPB-SSL-IFN-γ showed more significant remission of hepatic fibrosis. In vivo the histological Ishak stage, the semiquantitative score for collagen in fibrotic liver and the serum levels of collagen type IV-C in fibrotic rats treated with pPB-SSL-IFN-γ were less than those treated with SSL-IFN-γ, IFN-γ and the control group. In vitro pPB-SSL-IFN-γ was also more effective in suppressing activated HSC proliferation and inducing apoptosis of activated HSCs. Thus the data suggest that pPB-SSL-IFN-γ might be a more effective anti-fibrotic agent and a new opportunity for clinical therapy of hepatic fibrosis.

  11. Fibrogenic response of hepatic stellate cells in ovariectomised rats exposed to ketogenic diet.

    Bobowiec, R; Wojcik, M; Jaworska-Adamu, J; Tusinska, E

    2013-02-01

    The discrepancy about the role of estrogens in hepatic fibrogenesis and lack of studies addressed of ketogenic diet (KD) on hepatic stellate cells (HSC), prompted us to investigate the activity of HSC in control, KD- and thioacetamide (TAA)-administrated rats with different plasma concentration of estradiol (E2). HSC were isolated by the collagenase perfusion methods and separated by the Percoll gradient centrifugation. After the 4(th) and 8(th) day of incubation, lysates of HSC and the media were collected for further analysis. The HSC derived from KD-rats released remarkably more transforming growth factor (TGF)-β1 than cells obtained from animals fed with a standard diet. The ovariectomy of KD-rats markedly intensified the secretion of this fibrogenic cytokine on the 8(th) day of incubation (201.33 ±1 7.15 pg/ml). In HSC of rats exposed to E2, the TGF-β1 concentration did not exceed 157 ± 34.39 pg/ml. In respect to the collagen type I, the HSC obtained from ovariectomised KD-rats released an augmented amount of this ECM protein after the 8(th) day of culture (1.83 ± 0.14 U/ml). In the same time, higher quantities of ASMA appeared in the KD rats (1.41 ± 0.3 pg/mg protein). Exposition of rats to E2 did not markedly decrease the amount of ASMA. In summary, KD was able to induce morphological and functional changes in HSC, especially derived from rats deprived of ovarian estrogens. However, the preservation of E2 in ovariectomised rats didn't substantially alter the activation of HSC.

  12. Nitric oxide signals are interlinked with calcium signals in normal pancreatic stellate cells upon oxidative stress and inflammation.

    Jakubowska, Monika A; Ferdek, Pawel E; Gerasimenko, Oleg V; Gerasimenko, Julia V; Petersen, Ole H

    2016-08-01

    The mammalian diffuse stellate cell system comprises retinoid-storing cells capable of remarkable transformations from a quiescent to an activated myofibroblast-like phenotype. Activated pancreatic stellate cells (PSCs) attract attention owing to the pivotal role they play in development of tissue fibrosis in chronic pancreatitis and pancreatic cancer. However, little is known about the actual role of PSCs in the normal pancreas. These enigmatic cells have recently been shown to respond to physiological stimuli in a manner that is markedly different from their neighbouring pancreatic acinar cells (PACs). Here, we demonstrate the capacity of PSCs to generate nitric oxide (NO), a free radical messenger mediating, for example, inflammation and vasodilatation. We show that production of cytosolic NO in PSCs is unambiguously related to cytosolic Ca(2+) signals. Only stimuli that evoke Ca(2+) signals in the PSCs elicit consequent NO generation. We provide fresh evidence for the striking difference between signalling pathways in PSCs and adjacent PACs, because PSCs, in contrast to PACs, generate substantial Ca(2+)-mediated and NOS-dependent NO signals. We also show that inhibition of NO generation protects both PSCs and PACs from necrosis. Our results highlight the interplay between Ca(2+) and NO signalling pathways in cell-cell communication, and also identify a potential therapeutic target for anti-inflammatory therapies. © 2016 The Authors.

  13. Hepatic stellate cell and myofibroblast-like cell gene expression in the explanted cirrhotic livers of patients undergoing liver transplantation.

    Estep, J Michael; O'Reilly, Linda; Grant, Geraldine; Piper, James; Jonsson, Johann; Afendy, Arian; Chandhoke, Vikas; Younossi, Zobair M

    2010-02-01

    Hepatic stellate cells (HSC) are involved in hepatic fibrogenesis. Cell signaling associated with an insult to the liver affects an HSC transdifferentiation to fibrogenic myofibroblast-like cells. To investigate the transcriptional expression distinguishing HSC and myofibroblast-like cells between livers with and without cirrhosis. Tissue from ten cirrhotic livers (undergoing transplant) and four non-cirrhotic livers from the National Disease Research Interchange underwent cell separation to extract HSC and myofibroblast-like cell populations. Separated cell types as well as LI-90 cells were subjected to microarray analysis. Selected microarray results were verified by quantitative real-time PCR. Differential expression of some genes, such as IL-1beta, IL-1alpha, and IL-6, was associated with both transdifferentiation and disease. Other genes, such as fatty acid 2-hydroxylase only show differential expression in association with disease. Functional analysis supported these findings, indicating some signal transduction pathways (IL-6) are involved in disease and activation, whereas retinoid X receptor signaling in HSC from cirrhotic and non-cirrhotic livers varies in scope and quality. These findings indicate distinct phenotypes for HSC from cirrhotic and non-cirrhotic livers. Furthermore, coordinated differential expression between genes involved in the same signal transduction pathways provides some insight into the mechanisms that may control the balance between fibrogenesis and fibrolysis.

  14. Secreted phospholipase A2 of Clonorchis sinensis activates hepatic stellate cells through a pathway involving JNK signalling.

    Wu, Yinjuan; Li, Ye; Shang, Mei; Jian, Yu; Wang, Caiqin; Bardeesi, Adham Sameer A; Li, Zhaolei; Chen, Tingjin; Zhao, Lu; Zhou, Lina; He, Ai; Huang, Yan; Lv, Zhiyue; Yu, Xinbing; Li, Xuerong

    2017-03-16

    Secreted phospholipase A2 (sPLA2) is a protein secreted by Clonorchis sinensis and is a component of excretory and secretory products (CsESPs). Phospholipase A2 is well known for its role in liver fibrosis and inhibition of tumour cells. The JNK signalling pathway is involved in hepatic stellate cells (HSCs) activation. Blocking JNK activity with SP600125 inhibits HSCs activation. In a previous study, the protein CssPLA2 was expressed in insoluble inclusion bodies. Therefore, it's necessary to express CssPLA2 in water-soluble form and determine whether the enzymatic activity of CssPLA2 or cell signalling pathways is involved in liver fibrosis caused by clonorchiasis. Balb/C mice were given an abdominal injection of MBP-CssPLA2. Liver sections with HE and Masson staining were observed to detect accumulation of collagen. Western blot of mouse liver was done to detect the activation of JNK signalling pathway. In vitro, HSCs were incubated with MBP-CssPLA2 to detect the activation of HSCs as well as the activation of JNK signalling pathway. The mutant of MBP-CssPLA2 without enzymatic activity was constructed and was also incubated with HSCs to check whether activation of the HSCs was related to the enzymatic activity of MBP-CssPLA2. The recombinant protein MBP-CssPLA2 was expressed soluble and of good enzymatic activity. A mutant of CssPLA2, without enzymatic activity, was also constructed. In vivo liver sections of Balb/C mice that were given an abdominal injection of 50 μg/ml MBP-CssPLA2 showed an obvious accumulation of collagen and a clear band of P-JNK1 could be seen by western blot of the liver tissue. In vitro, MBP-CssPLA2, as well as the mutant, was incubated with HSCs and it was proved that activation of HSCs was related to activation of the JNK signalling pathway instead of the enzymatic activity of MBP-CssPLA2. Activation of HSCs by CssPLA2 is related to the activation of the JNK signalling pathway instead of the enzymatic activity of CssPLA2. This finding

  15. Some Lipid Droplets Are More Equal Than Others: Different Metabolic Lipid Droplet Pools in Hepatic Stellate Cells.

    Molenaar, Martijn R; Vaandrager, Arie B; Helms, J Bernd

    2017-01-01

    Hepatic stellate cells (HSCs) are professional lipid-storing cells and are unique in their property to store most of the retinol (vitamin A) as retinyl esters in large-sized lipid droplets. Hepatic stellate cell activation is a critical step in the development of chronic liver disease, as activated HSCs cause fibrosis. During activation, HSCs lose their lipid droplets containing triacylglycerols, cholesteryl esters, and retinyl esters. Lipidomic analysis revealed that the dynamics of disappearance of these different classes of neutral lipids are, however, very different from each other. Although retinyl esters steadily decrease during HSC activation, triacylglycerols have multiple pools one of which becomes transiently enriched in polyunsaturated fatty acids before disappearing. These observations are consistent with the existence of preexisting "original" lipid droplets with relatively slow turnover and rapidly recycling lipid droplets that transiently appear during activation of HSCs. Elucidation of the molecular machinery involved in the regulation of these distinct lipid droplet pools may open new avenues for the treatment of liver fibrosis.

  16. ATGL and CGI-58 are lipid droplet proteins of the hepatic stellate cell line HSC-T6.

    Eichmann, Thomas O; Grumet, Lukas; Taschler, Ulrike; Hartler, Jürgen; Heier, Christoph; Woblistin, Aaron; Pajed, Laura; Kollroser, Manfred; Rechberger, Gerald; Thallinger, Gerhard G; Zechner, Rudolf; Haemmerle, Günter; Zimmermann, Robert; Lass, Achim

    2015-10-01

    Lipid droplets (LDs) of hepatic stellate cells (HSCs) contain large amounts of vitamin A [in the form of retinyl esters (REs)] as well as other neutral lipids such as TGs. During times of insufficient vitamin A availability, RE stores are mobilized to ensure a constant supply to the body. To date, little is known about the enzymes responsible for the hydrolysis of neutral lipid esters, in particular of REs, in HSCs. In this study, we aimed to identify LD-associated neutral lipid hydrolases by a proteomic approach using the rat stellate cell line HSC-T6. First, we loaded cells with retinol and FAs to promote lipid synthesis and deposition within LDs. Then, LDs were isolated and lipid composition and the LD proteome were analyzed. Among other proteins, we found perilipin 2, adipose TG lipase (ATGL), and comparative gene identification-58 (CGI-58), known and established LD proteins. Bioinformatic search of the LD proteome for α/β-hydrolase fold-containing proteins revealed no yet uncharacterized neutral lipid hydrolases. In in vitro activity assays, we show that rat (r)ATGL, coactivated by rat (r)CGI-58, efficiently hydrolyzes TGs and REs. These findings suggest that rATGL and rCGI-58 are LD-resident proteins in HSCs and participate in the mobilization of both REs and TGs. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

  17. Albumin modified with mannose 6-phosphate : A potential carrier for selective delivery of antifibrotic drugs to rat and human hepatic stellate cells

    Beljaars, Leonie; Molema, Ingrid; Weert, B; Olinga, Peter; Groothuis, Geny; Meijer, D.K F; Poelstra, Klaas

    The hallmark of liver fibrosis is an increased extracellular matrix deposition, caused by an activation of hepatic stellate cells (HSC). Therefore, this cell type is an important target for pharmacotherapeutic intervention. Antifibrotic drugs are not efficiently taken up by HSC or may produce

  18. Effects of a new bioactive lipid-based drug carrier on cultured hepatic stellate cells and liver fibrosis in bile duct-ligated rats

    Adrian, Joanna E.; Poelstra, Klaas; Scherphof, Gerrit L.; Meijer, Dirk K. F.; van Loenen - Weemaes, Anne-miek; Reker-Smit, Catharina; Morselt, Henriette W. M.; Zwiers, Peter; Kamps, Jan A. A. M.

    In the fibrotic liver, hepatic stellate cells ( HSC) produce large amounts of collagen and secrete variety of mediators that promote development of fibrosis in this organ. Therefore, these cells are considered an attractive target for antifibrotic therapies. We incorporated the bioactive lipid

  19. Activated Hepatic Stellate Cells Induce Tumor Progression of Neoplastic Hepatocytes in a TGF-β Dependent Fashion

    MIKULA, M.; PROELL, V.; FISCHER, A.N.M.; MIKULITS, W.

    2010-01-01

    The development of hepatocellular carcinomas from malignant hepatocytes is frequently associated with intra- and peritumoral accumulation of connective tissue arising from activated hepatic stellate cells. For both tumorigenesis and hepatic fibrogenesis, transforming growth factor (TGF)-β signaling executes key roles and therefore is considered as a hallmark of these pathological events. By employing cellular transplantation we show that the interaction of neoplastic MIM-R hepatocytes with the tumor microenvironment, containing either activated hepatic stellate cells (M1-4HSCs) or myofibroblasts derived thereof (M-HTs), induces progression in malignancy. Cotransplantation of MIM-R hepatocytes with M-HTs yielded strongest MIM-R generated tumor formation accompanied by nuclear localization of Smad2/3 as well as of β-catenin. Genetic interference with TGF-β signaling by gain of antagonistic Smad7 in MIM-R hepatocytes diminished epithelial dedifferentiation and tumor progression upon interaction with M1-4HSCs or M-HTs. Further analysis showed that tumors harboring disrupted Smad signaling are devoid of nuclear β-catenin accumulation, indicating a crosstalk between TGF-β and β-catenin signaling. Together, these data demonstrate that activated HSCs and myofibroblasts directly govern hepatocarcinogenesis in a TGF-β dependent fashion by inducing autocrine TGF-β signaling and nuclear β-catenin accumulation in neoplastic hepatocytes. These results indicate that intervention with TGF-β signaling is highly promising in liver cancer therapy. PMID:16883581

  20. Interleukin-15 stimulates natural killer cell-mediated killing of both human pancreatic cancer and stellate cells

    Van Audenaerde, Jonas R.M.; De Waele, Jorrit; Marcq, Elly; Van Loenhout, Jinthe; Lion, Eva; Van den Bergh, Johan M.J.; Jesenofsky, Ralf; Masamune, Atsushi; Roeyen, Geert; Pauwels, Patrick; Lardon, Filip; Peeters, Marc; Smits, Evelien L.J.

    2017-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is the 4th leading cause of cancer-related death in Western countries with a 5-year survival rate below 5%. One of the hallmarks of this cancer is the strong desmoplastic reaction within the tumor microenvironment (TME), orchestrated by activated pancreatic stellate cells (PSC). This results in a functional and mechanical shield which causes resistance to conventional therapies. Aiming to overcome this resistance by tackling the stromal shield, we assessed for the first time the capacity of IL-15 stimulated natural killer (NK) cells to kill PSC and pancreatic cancer cells (PCC). The potency of IL-15 to promote NK cell-mediated killing was evaluated phenotypically and functionally. In addition, NK cell and immune checkpoint ligands on PSC were charted. We demonstrate that IL-15 activated NK cells kill both PCC and PSC lines (range 9-35% and 20-50%, respectively) in a contact-dependent manner and significantly higher as compared to resting NK cells. Improved killing of these pancreatic cell lines is, at least partly, dependent on IL-15 induced upregulation of TIM-3 and NKG2D. Furthermore, we confirm significant killing of primary PSC by IL-15 activated NK cells in an ex vivo autologous system. Screening for potential targets for immunotherapeutic strategies, we demonstrate surface expression of both inhibitory (PD-L1, PD-L2) and activating (MICA/B, ULBPs and Galectin-9) ligands on primary PSC. These data underscore the therapeutic potential of IL-15 to promote NK cell-mediated cytotoxicity as a treatment of pancreatic cancer and provide promising future targets to tackle remaining PSC. PMID:28915646

  1. Combining Vγ9Vδ2 T Cells with a Lipophilic Bisphosphonate Efficiently Kills Activated Hepatic Stellate Cells

    Xiaoying Zhou

    2017-10-01

    Full Text Available Activated hepatic stellate cells (aHSCs are now established as a central driver of fibrosis in human liver injury. In the presence of chronic or repeated injury, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC can occur, so there is interest in down-regulating aHSCs activity in order to treat these diseases. Here, we report that Vγ9Vδ2 T cells are reduced in patients with liver cirrhosis, stimulating us to investigate possible interactions between Vγ9Vδ2 T cells and aHSCs. We find that Vγ9Vδ2 T cells kill aHSCs and killing is enhanced when aHSCs are pretreated with BPH-1236, a lipophilic analog of the bone resorption drug zoledronate. Cytotoxicity is mediated by direct cell-to-cell contact as shown by Transwell experiments and atomic force microscopy, with BPH-1236 increasing the adhesion between aHSCs and Vγ9Vδ2 T cells. Mechanistically, BPH-1236 functions by inhibiting farnesyl diphosphate synthase, leading to accumulation of the phosphoantigen isopentenyl diphosphate and recognition by Vγ9Vδ2 T cells. The cytolytic process is largely dependent on the perforin/granzyme B pathway. In a Rag2−/−γc−/− immune-deficient mouse model, we find that Vγ9Vδ2 T cells home-in to the liver, and when accompanied by BPH-1236, kill not only orthotopic aHSCs but also orthotopic HCC tumors. Collectively, our results provide the first proof-of-concept of a novel immunotherapeutic strategy for the treatment of fibrosis–cirrhosis–HCC diseases using adoptively transferred Vγ9Vδ2 T cells, combined with a lipophilic bisphosphonate.

  2. Silent information regulator 1 (SIRT1) ameliorates liver fibrosis via promoting activated stellate cell apoptosis and reversion

    Wu, Yuting, E-mail: wuyuting1302@sina.com; Liu, Xuejiao; Zhou, Qun; Huang, Cheng; Meng, Xiaoming; Xu, Fengyun; Li, Jun, E-mail: lj@ahmu.edu.cn

    2015-12-01

    SIRT1 (silent information regulator 1), a conserved NAD +-dependent histone deacetylase, is closely related with various biological processes. Moreover, the important role of SIRT1 in alcoholic liver disease, nonalcoholic fatty liver and HCC had been widely reported. Recently, a novel role of SIRT1 was uncovered in organ fibrosis diseases. Here, we investigated the inhibitory effect of SIRT1 in liver fibrogenesis. SIRT1 protein was dramatically decreased in CCl4-treated mice livers. Stimulation of LX-2 cells with TGF-β1 also resulted in a significant suppression of SIRT1 protein. Nevertheless, TGF-β1-induced LX-2 cell activation was inhibited by SIRT1 plasmid, and this was accompanied by up-regulation of cell apoptosis-related proteins. Overexpression of SIRT1 also attenuated TGF-β1-induced expression of myofibroblast markers α-SMA and COL1a. However, the important characteristic of the recovery of liver fibrosis is not only the apoptosis of activated stellate cells but also the reversal of the myofibroblast-like phenotype to a quiescent-like phenotype. Restoration of SIRT1 protein was observed in the in vivo spontaneously liver fibrosis reversion model and in vitro MDI (isobutylmethylxanthine, dexamethasone, and insulin)-induced reversed stellate cells, and forced expression of SIRT1 also promoted the reversal of activated stellate cells. Furthermore, lncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) was increased in liver fibrosis. RNAi-mediated suppression of MALAT1 resulted in a decrease of myofibroblast markers and restoration of SIRT1 protein. These observations suggested that SIRT1 contributed to apoptosis and reversion of activated LX-2 cells and SIRT1 might be regulated by MALAT1 in liver fibrosis. Therefore, SIRT1 could be considered as a valuable therapeutic target for translational studies of liver fibrosis. - Highlights: • This is the first report of SIRT1 expression and function in liver fibrogenesis and reversion.

  3. ADAM12 in human liver cancers: TGF-beta-regulated expression in stellate cells is associated with matrix remodeling

    Le Pabic, Hélène; Bonnier, Dominique; Wewer, Ulla M

    2003-01-01

    "A disintegrin and metalloproteinases" (ADAMs) form a family of cell-surface glycoproteins with potential protease and cell-adhesion activities. We have investigated ADAM expression in human liver cancers and their regulation by several cytokines involved in liver injury. Using degenerative RT...... carcinomas (up to 3- and 6-fold, respectively) and liver metastases from colonic carcinomas (up to 40- and 60-fold, respectively). The up-regulation of both ADAM9 and ADAM12 was correlated with an increase in matrix metalloproteinase 2 expression and activity. In conclusion, in liver cancers ADAM9 and ADAM12......-PCR, cDNA encoding sequences for ADAM9 and ADAM12 were identified in human activated hepatic stellate cells (HSCs). Northern blot analyses showed that HSCs, but not hepatocytes, expressed transcripts for ADAM9 messenger RNA (mRNA) and both the long and short forms of ADAM12. This expression...

  4. Simultaneous characterization of pancreatic stellate cells and other pancreatic components within three-dimensional tissue environment during chronic pancreatitis

    Hu, Wenyan; Fu, Ling

    2013-05-01

    Pancreatic stellate cells (PSCs) and other pancreatic components that play a critical role in exocrine pancreatic diseases are generally identified separately by conventional studies, which provide indirect links between these components. Here, nonlinear optical microscopy was evaluated for simultaneous characterization of these components within a three-dimensional (3-D) tissue environment, primarily based on multichannel detection of intrinsic optical emissions and cell morphology. Fresh rat pancreatic tissues harvested at 1 day, 7 days, and 28 days after induction of chronic pancreatitis were imaged, respectively. PSCs, inflammatory cells, blood vessels, and collagen fibers were identified simultaneously. The PSCs at day 1 of chronic pancreatitis showed significant enlargement compared with those in normal pancreas (ppancreatic components coincidently within 3-D pancreatic tissues. It is a prospect for intravital observation of dynamic events under natural physiological conditions, and might help uncover the key mechanisms of exocrine pancreatic diseases, leading to more effective treatments.

  5. A role of pancreatic stellate cells in islet fibrosis and β-cell dysfunction in type 2 diabetes mellitus

    Lee, Esder; Ryu, Gyeong Ryul; Ko, Seung-Hyun; Ahn, Yu-Bae; Song, Ki-Ho

    2017-01-01

    Objectives: To investigate whether the activation of pancreatic stellate cells (PSCs) leads to pancreatic β-cell dysfunction in type 2 diabetes mellitus (T2DM). Methods: The pancreases of Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an animal model of T2DM, and patient with T2DM were analyzed. And the in vitro and in vivo effects of pirfenidone, an antifibrotic agent, on PSC activation, islet fibrosis, and β-cells were studied. Results: The extent of islet fibrosis and the percentage of activated PSCs, positive for α-smooth muscle actin, in the islets were significantly greater in OLETF rats compared with non-diabetic rats. Also, the extent of islet fibrosis in patients with T2DM was slightly greater compared with age- and BMI-matched non-diabetic patients. In rat PSCs cultured with high glucose for 72 h, pirfenidone produced decreases in cell proliferation, release of collagen, and the expression of fibronectin and connective tissue growth factor. Treatment of OLETF rats with pirfenidone for 16 weeks decreased the activation of PSCs and the extent of islet fibrosis, but did not enhance glucose tolerance, pancreatic insulin content, or β-cell mass. Conclusions: Activated PSCs in islets might lead to islet fibrosis in T2DM. However, PSC activation itself might not contribute significantly to progressive β-cell failure in T2DM. - Highlights: • Islet fibrosis developed progressively in OLETF rats, a model of type 2 diabetes. • PSCs in the islets became activated in OLETF rats. • Islet fibrosis was increased in patients with type 2 diabetes. • Pirfenidone attenuated the activation of PSCs and islet fibrosis in OLETF rats. • Pirfenidonet had no effects on glucose tolerance or on β-cells in OLETF rats.

  6. Fasting inhibits hepatic stellate cells activation and potentiates anti-cancer activity of Sorafenib in hepatocellular cancer cells.

    Lo Re, Oriana; Panebianco, Concetta; Porto, Stefania; Cervi, Carlo; Rappa, Francesca; Di Biase, Stefano; Caraglia, Michele; Pazienza, Valerio; Vinciguerra, Manlio

    2018-02-01

    Hepatocellular carcinoma (HCC) has a poor outcome. Most HCCs develop in the context of liver fibrosis and cirrhosis caused by chronic inflammation. Short-term fasting approaches enhance the activity of chemotherapy in preclinical cancer models, other than HCC. Multi-tyrosine kinase inhibitor Sorafenib is the mainstay of treatment in HCC. However, its benefit is frequently short-lived. Whether fasting can alleviate liver fibrosis and whether combining fasting with Sorafenib is beneficial remains unknown. A 24 hr fasting (2% serum, 0.1% glucose)-induced changes on human hepatic stellate cells (HSC) LX-2 proliferation/viability/cell cycle were assessed by MTT and flow cytometry. Expression of lypolysaccharide (LPS)-induced activation markers (vimentin, αSMA) was evaluated by qPCR and immunoblotting. Liver fibrosis and inflammation were evaluated in a mouse model of steatohepatitis exposed to cycles of fasting, by histological and biochemical analyses. A 24 hr fasting-induced changes were also analyzed on the proliferation/viability/glucose uptake of human HCC cells exposed to Sorafenib. An expression panel of genes involved in survival, inflammation, and metabolism was examined by qPCR in HCC cells exposed to fasting and/or Sorafenib. Fasting decreased the proliferation and the activation of HSC. Repeated cycles of short term starvation were safe in mice but did not improve fibrosis. Fasting synergized with Sorafenib in hampering HCC cell growth and glucose uptake. Finally, fasting normalized the expression levels of genes which are commonly altered by Sorafenib in HCC cells. Fasting or fasting-mimicking diet diets should be evaluated in preclinical studies as a mean to potentiate the activity of Sorafenib in clinical use. © 2017 Wiley Periodicals, Inc.

  7. Treatment with 4-methylpyrazole modulated stellate cells and natural killer cells and ameliorated liver fibrosis in mice.

    Hyon-Seung Yi

    Full Text Available Accumulating evidence suggests that retinol and its metabolites are closely associated with liver fibrogenesis. Recently, we demonstrated that genetic ablation of alcohol dehydrogenase 3 (ADH3, a retinol metabolizing gene that is expressed in hepatic stellate cells (HSCs and natural killer (NK cells, attenuated liver fibrosis in mice. In the current study, we investigated whether pharmacological ablation of ADH3 has therapeutic effects on experimentally induced liver fibrosis in mice.Liver fibrosis was induced by intraperitoneal injections of carbon tetrachloride (CCl4 or bile duct ligation (BDL for two weeks. To inhibit ADH3-mediated retinol metabolism, 10 μg 4-methylpyrazole (4-MP/g of body weight was administered to mice treated with CCl4 or subjected to BDL. The mice were sacrificed at week 2 to evaluate the regression of liver fibrosis. Liver sections were stained for collagen and α-smooth muscle actin (α-SMA. In addition, HSCs and NK cells were isolated from control and treated mice livers for molecular and immunological studies.Treatment with 4-MP attenuated CCl4- and BDL-induced liver fibrosis in mice, without any adverse effects. HSCs from 4-MP treated mice depicted decreased levels of retinoic acids and increased retinol content than HSCs from control mice. In addition, the expression of α-SMA, transforming growth factor-β1 (TGF-β1, and type I collagen α1 was significantly reduced in the HSCs of 4-MP treated mice compared to the HSCs from control mice. Furthermore, inhibition of retinol metabolism by 4-MP increased interferon-γ production in NK cells, resulting in increased apoptosis of activated HSCs.Based on our data, we conclude that inhibition of retinol metabolism by 4-MP ameliorates liver fibrosis in mice through activation of NK cells and suppression of HSCs. Therefore, retinol and its metabolizing enzyme, ADH3, might be potential targets for therapeutic intervention of liver fibrosis.

  8. A retinoic acid receptor β2 agonist reduces hepatic stellate cell activation in nonalcoholic fatty liver disease.

    Trasino, Steven E; Tang, Xiao-Han; Jessurun, Jose; Gudas, Lorraine J

    2016-10-01

    Hepatic stellate cells (HSCs) are an important cellular target for the development of novel pharmacological therapies to prevent and treat nonalcoholic fatty liver diseases (NAFLD). Using a high fat diet (HFD) model of NAFLD, we sought to determine if synthetic selective agonists for retinoic acid receptor β2 (RARβ2) and RARγ can mitigate HSC activation and HSC relevant signaling pathways during early stages of NAFLD, before the onset of liver injury. We demonstrate that the highly selective RARβ2 agonist, AC261066, can reduce the activation of HSCs, marked by decreased HSC expression of α-smooth muscle actin (α-SMA), in mice with HFD-induced NAFLD. Livers of HFD-fed mice treated with AC261066 exhibited reduced steatosis, oxidative stress, and expression of pro-inflammatory mediators, such as tumor necrosis factor-alpha (TNFα), interleukin 1β (IL-1β), and monocyte chemotactic protein-1 (MCP-1). Kupffer cell (macrophage) expression of transforming growth factor-β1 (TGF-β1), which plays a critical role in early HSC activation, was markedly reduced in AC261066-treated, HFD-fed mice. In contrast, HFD-fed mice treated with an RARγ agonist (CD1530) showed no decreases in steatosis, HSC activation, or Kupffer cell TGF-β1 levels. In conclusion, our data demonstrate that RARβ2 is an attractive target for development of NAFLD therapies. • Hepatic stellate cells (HSCs) are an important pharmacological target for the prevention of nonalcoholic fatty liver diseases (NAFLD). • Retinoids and retinoic acid receptors (RARs) possess favorable metabolic modulating properties. • We show that an agonist for retinoic acid receptor-β2 (RARβ2), but not RARγ, mitigates HSC activation and NAFLD.

  9. Mitochondria-targeted antioxidant mitoquinone deactivates human and rat hepatic stellate cells and reduces portal hypertension in cirrhotic rats.

    Vilaseca, Marina; García-Calderó, Héctor; Lafoz, Erica; Ruart, Maria; López-Sanjurjo, Cristina Isabel; Murphy, Michael P; Deulofeu, Ramon; Bosch, Jaume; Hernández-Gea, Virginia; Gracia-Sancho, Jordi; García-Pagán, Juan Carlos

    2017-07-01

    In cirrhosis, activated hepatic stellate cells (HSC) play a major role in increasing intrahepatic vascular resistance and developing portal hypertension. We have shown that cirrhotic livers have increased reactive oxygen species (ROS), and that antioxidant therapy decreases portal pressure. Considering that mitochondria produce many of these ROS, our aim was to assess the effects of the oral mitochondria-targeted antioxidant mitoquinone on hepatic oxidative stress, HSC phenotype, liver fibrosis and portal hypertension. Ex vivo: Hepatic stellate cells phenotype was analysed in human precision-cut liver slices in response to mitoquinone or vehicle. In vitro: Mitochondrial oxidative stress was analysed in different cell type of livers from control and cirrhotic rats. HSC phenotype, proliferation and viability were assessed in LX2, and in primary human and rat HSC treated with mitoquinone or vehicle. In vivo: CCl 4 - and thioacetamide-cirrhotic rats were treated with mitoquinone (5 mg/kg/day) or the vehicle compound, DecylTPP, for 2 weeks, followed by measurement of oxidative stress, systemic and hepatic haemodynamic, liver fibrosis, HSC phenotype and liver inflammation. Mitoquinone deactivated human and rat HSC, decreased their proliferation but with no effects on viability. In CCl 4 -cirrhotic rats, mitoquinone decreased hepatic oxidative stress, improved HSC phenotype, reduced intrahepatic vascular resistance and diminished liver fibrosis. These effects were associated with a significant reduction in portal pressure without changes in arterial pressure. These results were further confirmed in the thioacetamide-cirrhotic model. We propose mitochondria-targeted antioxidants as a novel treatment approach against portal hypertension and cirrhosis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. High Glucose Aggravates the Detrimental Effects of Pancreatic Stellate Cells on Beta-Cell Function

    Min Zha

    2014-01-01

    Full Text Available Background and Aims. We here assess the effects of PSCs on β-cell function and apoptosis in vivo and in vitro. Materials and Methods. PSCs were transplanted into Wistar and Goto-Kakizaki (GK rats. Sixteen weeks after transplantation, β-cell function, apoptosis, and islet fibrosis were assessed. In vitro the effects of PSCs conditioned medium (PSCs-CM and/or high concentration of glucose on INS-1 cell function was assessed by measuring insulin secretion, INS-1 cell survival, apoptosis, and endoplasmic reticulum stress (ER stress associated CHOP expression. Results. PSCs transplantation exacerbated the impaired β-cell function in GK rats, but had no significant effects in Wistar rats. In vitro, PSCs-CM caused impaired INS-1 cell viability and insulin secretion and increased apoptosis, which were more pronounced in the presence of high glucose. Conclusion. Our study demonstrates that PSCs induce β-cell failure in vitro and in vivo.

  11. [THE TECHNOLOGY "CELL BLOCK" IN CYTOLOGICAL PRACTICE].

    Volchenko, N N; Borisova, O V; Baranova, I B

    2015-08-01

    The article presents summary information concerning application of "cell block" technology in cytological practice. The possibilities of implementation of various modern techniques (immune cytochemnical analysis. FISH, CISH, polymerase chain reaction) with application of "cell block" method are demonstrated. The original results of study of "cell block" technology made with gelatin, AgarCyto and Shadon Cyoblock set are presented. The diagnostic effectiveness of "cell block" technology and common cytological smear and also immune cytochemical analysis on samples of "cell block" technology and fluid cytology were compared. Actually application of "cell block" technology is necessary for ensuring preservation of cell elements for subsequent immune cytochemical and molecular genetic analysis.

  12. Orphan nuclear receptor NR4A2 inhibits hepatic stellate cell proliferation through MAPK pathway in liver fibrosis.

    Chen, Pengguo; Li, Jie; Huo, Yan; Lu, Jin; Wan, Lili; Li, Bin; Gan, Run; Guo, Cheng

    2015-01-01

    Hepatic stellate cells (HSCs) play a crucial role in liver fibrosis, which is a pathological process characterized by extracellular matrix accumulation. NR4A2 is a nuclear receptor belonging to the NR4A subfamily and vital in regulating cell growth, metabolism, inflammation and other biological functions. However, its role in HSCs is unclear. We analyzed NR4A2 expression in fibrotic liver and stimulated HSCs compared with control group and studied the influence on cell proliferation, cell cycle, cell apoptosis and MAPK pathway after NR4A2 knockdown. NR4A2 expression was examined by real-time polymerase chain reaction, Western blotting, immunohistochemistry and immunofluorescence analyses. NR4A2 expression was significantly lower in fibrotic liver tissues and PDGF BB or TGF-β stimulated HSCs compared with control group. After NR4A2 knockdown α-smooth muscle actin and Col1 expression increased. In addition, NR4A2 silencing led to the promotion of cell proliferation, increase of cell percentage in S phase and reduced phosphorylation of ERK1/2, P38 and JNK in HSCs. These results indicate that NR4A2 can inhibit HSC proliferation through MAPK pathway and decrease extracellular matrix in liver fibrogenesis. NR4A2 may be a promising therapeutic target for liver fibrosis.

  13. The CYP2E1 inhibitor DDC up-regulates MMP-1 expression in hepatic stellate cells via an ERK1/2- and Akt-dependent mechanism.

    Liu, Tianhui; Wang, Ping; Cong, Min; Xu, Youqing; Jia, Jidong; You, Hong

    2013-06-05

    DDC (diethyldithiocarbamate) could block collagen synthesis in HSC (hepatic stellate cells) through the inhibition of ROS (reactive oxygen species) derived from hepatocyte CYP2E1 (cytochrome P450 2E1). However, the effect of DDC on MMP-1 (matrix metalloproteinase-1), which is the main collagen degrading matrix metalloproteinase, has not been reported. In co-culture experiments, we found that DDC significantly enhanced MMP-1 expression in human HSC (LX-2) that were cultured with hepatocyte C3A cells either expressing or not expressing CYP2E1. The levels of both proenzyme and active MMP-1 enzyme were up-regulated in LX-2 cells, accompanied by elevated enzyme activity of MMP-1 and decreased collagen I, in both LX-2 cells and the culture medium. H2O2 treatment abrogated DDC-induced MMP-1 up-regulation and collagen I decrease, while catalase treatment slightly up-regulated MMP-1 expression. These data suggested that the decrease in ROS by DDC was partially responsible for the MMP-1 up-regulation. ERK1/2 (extracellular signal-regulated kinase 1/2), Akt (protein kinase B) and p38 were significantly activated by DDC. The ERK1/2 inhibitor (U0126) and Akt inhibitor (T3830) abrogated the DDC-induced MMP-1 up-regulation. In addition, a p38 inhibitor (SB203580) improved MMP-1 up-regulation through the stimulation of ERK1/2. Our data indicate that DDC significantly up-regulates the expression of MMP-1 in LX-2 cells which results in greater MMP-1 enzyme activity and decreased collagen I. The enhancement of MMP-1 expression by DDC was associated with H2O2 inhibition and coordinated regulation by the ERK1/2 and Akt pathways. These data provide some new insights into treatment strategies for hepatic fibrosis.

  14. Profiling of Concanavalin A-Binding Glycoproteins in Human Hepatic Stellate Cells Activated with Transforming Growth Factor-β1

    Yannan Qin

    2014-11-01

    Full Text Available Glycoproteins play important roles in maintaining normal cell functions depending on their glycosylations. Our previous study indicated that the abundance of glycoproteins recognized by concanavalin A (ConA was increased in human hepatic stellate cells (HSCs following activation by transforming growth factor-β1 (TGF-β1; however, little is known about the ConA-binding glycoproteins (CBGs of HSCs. In this study, we employed a targeted glycoproteomics approach using lectin-magnetic particle conjugate-based liquid chromatography-tandem mass spectrometry to compare CBG profiles between LX-2 HSCs with and without activation by TGF-β1, with the aim of discovering novel CBGs and determining their possible roles in activated HSCs. A total of 54 and 77 proteins were identified in the quiescent and activated LX-2 cells, respectively. Of the proteins identified, 14.3% were glycoproteins and 73.3% were novel potential glycoproteins. Molecules involved in protein processing in the endoplasmic reticulum (e.g., calreticulin and calcium signaling (e.g., 1-phosphatidylinositol-4,5-bisphosphate phosphodiesterase β-2 [PLCB2] were specifically identified in activated LX-2 cells. Additionally, PLCB2 expression was upregulated in the cytoplasm of the activated LX-2 cells, as well as in the hepatocytes and sinusoidal cells of liver cirrhosis tissues. In conclusion, the results of this study may aid future investigations to find new molecular mechanisms involved in HSC activation and antifibrotic therapeutic targets.

  15. The Effector Protein BPE005 from Brucella abortus Induces Collagen Deposition and Matrix Metalloproteinase 9 Downmodulation via Transforming Growth Factor β1 in Hepatic Stellate Cells.

    Arriola Benitez, Paula Constanza; Rey Serantes, Diego; Herrmann, Claudia Karina; Pesce Viglietti, Ayelén Ivana; Vanzulli, Silvia; Giambartolomei, Guillermo Hernán; Comerci, Diego José; Delpino, María Victoria

    2016-02-01

    The liver is frequently affected in patients with active brucellosis. In the present study, we identified a virulence factor involved in the modulation of hepatic stellate cell function and consequent fibrosis during Brucella abortus infection. This study assessed the role of BPE005 protein from B. abortus in the fibrotic phenotype induced on hepatic stellate cells during B. abortus infection in vitro and in vivo. We demonstrated that the fibrotic phenotype induced by B. abortus on hepatic stellate (LX-2) cells was dependent on BPE005, a protein associated with the type IV secretion system (T4SS) VirB from B. abortus. Our results indicated that B. abortus inhibits matrix metalloproteinase 9 (MMP-9) secretion through the activity of the BPE005-secreted protein and induces concomitant collagen deposition by LX-2 cells. BPE005 is a small protein containing a cyclic nucleotide monophosphate binding domain (cNMP) that modulates the LX-2 cell phenotype through a mechanism that is dependent on the cyclic AMP (cAMP)/protein kinase A (PKA) signaling pathway. Altogether, these results indicate that B. abortus tilts LX-2 cells to a profibrogenic phenotype employing a functional T4SS and the secreted BPE005 protein through a mechanism that involves the cAMP and PKA signaling pathway. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  16. Autophagy induced by purple pitanga (Eugenia uniflora L.) extract triggered a cooperative effect on inducing the hepatic stellate cell death.

    Denardin, Cristiane C; Martins, Leo A M; Parisi, Mariana M; Vieira, Moema Queiroz; Terra, Silvia R; Barbé-Tuana, Florencia M; Borojevic, Radovan; Vizzotto, Márcia; Emanuelli, Tatiana; Guma, Fátima Costa Rodrigues

    2017-04-01

    Activated hepatic stellate cells (HSC) are the major source of collagen I in liver fibrosis. Eugenia uniflora L. is a tree species that is widely distributed in South America. E. uniflora L. fruit-popularly known as pitanga-has been shown to exert beneficial properties. Autophagy contributes to the maintenance of cellular homeostasis and survival under stress situation, but it has also been suggested to be an alternative cell death pathway. Mitochondria play a pivotal role on signaling cell death. Mitophagy of damaged mitochondria is an important cell defense mechanism against organelle-mediated cell death signaling. We previously found that purple pitanga extract induced mitochondrial dysfunction, cell cycle arrest, and death by apoptosis and necrosis in GRX cells, a well-established activated HSC line. We evaluated the effects of 72-h treatment with crescent concentrations of purple pitanga extract (5 to 100 μg/mL) on triggering autophagy in GRX cells, as this is an important mechanism to cells under cytotoxic conditions. We found that all treated cells presented an increase in the mRNA expression of autophagy-related protein 7 (ATG7). Concomitantly, flow cytometry and ultrastructural analysis of treated cells revealed an increase of autophagosomes/autolysosomes that consequentially led to an increased mitophagy. As purple pitanga extract was previously found to be broadly cytotoxic to GRX cells, we postulated that autophagy contributes to this scenario, where cell death seems to be an inevitable fate. Altogether, the effectiveness on inducing activated HSC death can make purple pitanga extract a good candidate on treating liver fibrosis.

  17. Antihepatic Fibrosis Effect of Active Components Isolated from Green Asparagus (Asparagus officinalis L.) Involves the Inactivation of Hepatic Stellate Cells.

    Zhong, Chunge; Jiang, Chunyu; Xia, Xichun; Mu, Teng; Wei, Lige; Lou, Yuntian; Zhang, Xiaoshu; Zhao, Yuqing; Bi, Xiuli

    2015-07-08

    Green asparagus (Asparagus officinalis L.) is a vegetable with numerous nutritional properties. In the current study, a total of 23 compounds were isolated from green asparagus, and 9 of these compounds were obtained from this genus for the first time. Preliminary data showed that the ethyl acetate (EtOAc)-extracted fraction of green asparagus exerted a stronger inhibitory effect on the growth of t-HSC/Cl-6 cells, giving an IC50 value of 45.52 μg/mL. The biological activities of the different compounds isolated from the EtOAc-extracted fraction with respect to antihepatic fibrosis were investigated further. Four compounds, C3, C4, C10, and C12, exhibited profound inhibitory effect on the activation of t-HSC/Cl-6 cells induced by TNF-α. The activation t-HSC/Cl-6 cells, which led to the production of fibrotic matrix (TGF-β1, activin C) and accumulation of TNF-α, was dramatically decreased by these compounds. The mechanisms by which these compounds inhibited the activation of hepatic stellate cells appeared to be associated with the inactivation of TGF-β1/Smad signaling and c-Jun N-terminal kinases, as well as the ERK phosphorylation cascade.

  18. Histological and immunohistochemical effects of Curcuma longa on activation of rat hepatic stellate cells after cadmium induced hepatotoxicity.

    El-Mansy, A A; Mazroa, S A; Hamed, W S; Yaseen, A H; El-Mohandes, E A

    2016-01-01

    The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.

  19. Anti-fibrotic and anti-tumorigenic effects of rhein, a natural anthraquinone derivative, in mammalian stellate and carcinoma cells.

    Tsang, Siu Wai; Bian, Zhao-Xiang

    2015-03-01

    Anthraquinone compounds have been recognized to possess antiinflammatory, anti-fibrotic and anti-tumour properties and thus applied in human and veterinary therapeutics as active substances of medicinal products. Amongst the anthraquinones isolated from Rheum palmatum, also known as da-huang, rhein was detected as one of the highest metabolite contents in the bloodstream of mammals. The biological activities of rhein therefore deserve detailed investigation. In this study, we aimed to delineate the mechanism of inhibitory actions of rhein on fibrotic and tumorigenic processes by means of various biochemical assays, such as immunofluorescent staining, real-time polymerase chain reaction (PCR) and western blotting analyses in rat pancreatic stellate cells (LTC-14), human pancreatic ductal adenocarcinoma cells (PANC-1) and human colon carcinoma cells (SW480 and SW620). Our results demonstrated that the application of rhein notably suppressed the mRNA and protein levels of various fibrotic and tumorigenic mediators including alpha-smooth muscle actin, type I collagen, fibronectin, N-cadherin and matrix metalloproteinases in the testing mammalian cells. The mechanism of the suppressive actions of rhein was associated with the modulation of the sonic hedgehog and serine-threonine kinase signalling pathways. In conclusion, we suggest that rhein may serve as a therapeutic or an adjuvant agent in anti-fibrotic and anti-tumorigenic approaches. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Hesperitin derivative-11 suppress hepatic stellate cell activation and proliferation by targeting PTEN/AKT pathway

    Li, Wan-xia; Chen, Xin; Yang, Yang; Huang, Hui-min; Li, Hai-di; Huang, Cheng; Meng, Xiao-ming; Li, Jun

    2017-01-01

    Hesperitin derivative (HD-11) is a monomeric compound derived from Hesperidin, which is a naturally occurring flavanone glycoside that exerts extensive clinical effects such as anti-inflammatory, anti-oxidant and anti-angiogenic. However, the role and fundamental mechanism of HD-11 in hepatic fibrosis are still unrevealed. In this study, HD-11 not only alleviates ECM deposition in rats with liver fibrosis, but also reduces the expression of α-SMA and col1a1 in TGF-β1-induced HSC-T6 cells. Moreover, it was demonstrated that HD-11 significantly promoted the expression of PTEN in vivo and in vitro. In order to evaluate the involvement of HD-11 in TGF-β1-induced HSC-T6 activation, a specific blocking agent of PTEN (bpv) and PTEN small interfering (si)-RNA-mediated silencing were used. Interestingly, HD-11 treatment couldn’t inhibit α-SMA and col1a1 expression on the basis of PTEN knockdown. On the contrary, over-expression of PTEN had an opposite effect on the expression of α-SMA and col1a1 in TGF-β1-induced HSC-T6 cells after treatment of HD-11. In addition, HD-11 remarkably inhibited the expression of p-AKT in vivo and in vitro. Taken together, all the above results indicate that HD-11 may play the part of an effective modulator of PTEN/AKT signaling pathway.

  1. Long non-coding RNA APTR promotes the activation of hepatic stellate cells and the progression of liver fibrosis

    Yu, Fujun [Department of Gastroenterology, Jinshan Hospital of Fudan University, Jinshan, Shanghai, 201508 (China); Zheng, Jianjian [Wenzhou Key Laboratory of Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000 (China); Mao, Yuqing [Department of Gastroenterology, Jinshan Hospital of Fudan University, Jinshan, Shanghai, 201508 (China); Dong, Peihong [Department of Infectious Diseases, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000 (China); Li, Guojun [Department of Hepatology, Ningbo Yinzhou Second Hospital, Ningbo, 315000 (China); Lu, Zhongqiu [Department of Emergency, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000 (China); Guo, Chuanyong; Liu, Zhanju [Department of Gastroenterology, Shanghai Tenth People' s Hospital, Tongji University School of Medicine, Shanghai, 200072 (China); Fan, Xiaoming, E-mail: ktsqdph@163.com [Department of Gastroenterology, Jinshan Hospital of Fudan University, Jinshan, Shanghai, 201508 (China)

    2015-08-07

    In this study, we aimed at assessing a role of Alu-mediated p21 transcriptional regulator (APTR) in hepatofibrogenesis. APTR was upregulated in fibrotic liver samples and activated hepatic stellate cells (HSCs). Knockdown of APTR inhibited the activation of HSCs in vitro and mitigated the accumulation of collagen in vivo. Importantly, APTR silencing could abrogate TGF-β{sub 1}-induced upregulation of α-SMA in HSCs. In addition, inhibition of cell cycle and cell proliferation by APTR knockdown was attenuated by p21 siRNA1 in primary HSCs. Finally, serum APTR levels were increased in patients with liver cirrhosis, indicating a potential biomarker for liver cirrhosis. Collectively, evidence is proposed for a new biological role of APTR in hepatofibrogenesis. - Highlights: • APTR is upregulated in fibrotic liver tissues and activated HSCs. • APTR silencing inhibits HSC activation and the progression of liver fibrosis. • Antifibrotic effect of APTR silencing is achieved by increasing p21.

  2. A TLR4/MD2 fusion protein inhibits LPS-induced pro-inflammatory signaling in hepatic stellate cells

    Schnabl, Bernd; Brandl, Katharina; Fink, Marina; Gross, Philipp; Taura, Kojiro; Gaebele, Erwin; Hellerbrand, Claus; Falk, Werner

    2008-01-01

    Activated hepatic stellate cells (HSCs) play a key role in hepatic fibrogenesis. In injured liver they are the main extracellular matrix protein producing cell type and further perpetuate hepatic injury by secretion of pro-inflammatory mediators. Since LPS-mediated signaling through toll-like receptor 4 (TLR4) has been identified as key fibrogenic signal in HSCs we aimed to test TLR4 as potential target of therapy via ligand-binding soluble receptors. Incubation of human HSCs with a fusion protein between the extracellular domain of TLR4 and MD2 which binds LPS inhibited LPS-induced NFκB and JNK activation. TLR4/MD2 abolished LPS-induced secretion of IL-6, IL-8, MCP1, and RANTES in HSCs. In addition, TLR4/MD2 fused to human IgG-Fc neutralized LPS activity. Since TLR4 mutant mice are resistant to liver fibrosis, the TLR4/MD2 soluble receptor might represent a new therapeutic molecule for liver fibrogenesis in vivo

  3. Loss of expression of miR-335 is implicated in hepatic stellate cell migration and activation

    Chen, Chao; Wu, Chao-Qun; Zhang, Zong-Qi; Yao, Ding-Kang; Zhu, Liang

    2011-01-01

    Activation and migration of resident stellate cells (HSCs) within the hepatic space of Disse play an important role in hepatic fibrosis, which accounts for the increased numbers of activated HSCs in areas of inflammation during hepatic fibrosis. Currently, microRNAs have been found to play essential roles in HSC differentiation, proliferation, apoptosis, fat accumulation and collagen production. However, little is known about microRNA mediated HSC activation and migration. In this study, the miRNA expression profiles of quiescent HSCs, partially activated HSCs and fully activated HSCs were compared in pairs. Gene ontology (GO) and GO-Map network analysis indicated that the activation of HSCs was regulated by microRNAs. Among them miR-335 was confirmed to be significantly reduced during HSC activation by qRT-PCR, and restoring expression of miR-335 inhibited HSC migration and reduced α-SMA and collagen type I. Previous study revealed that tenascin-C (TNC), an extracellular matrix glycoprotein involved in cell migration, might be a target of miR-335. Therefore, we further studied the TNC expression in miR-335 over-expressed HSCs. Our data showed that exogenous TNC could enhance HSC migration in vitro and miR-335 restoration resulted in a significant inhibition of TNC expression. These results demonstrated that miR-335 restoration inhibited HSC migration, at least in part, via downregulating the TNC expression.

  4. Loss of expression of miR-335 is implicated in hepatic stellate cell migration and activation

    Chen, Chao [Department of Gastroenterology, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200003 (China); Wu, Chao-Qun [Genetics Institute, Fudan University, No. 220 Handan Road, Shanghai 200433 (China); Zhang, Zong-Qi [Department of Cardiology, No. 3 Hospital, Shanghai Jiao Tong University Medical school, No.280 Mohe Road, Shanghai 201900 (China); Yao, Ding-Kang; Zhu, Liang, E-mail: 15900611429@163.com [Department of Gastroenterology, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200003 (China)

    2011-07-15

    Activation and migration of resident stellate cells (HSCs) within the hepatic space of Disse play an important role in hepatic fibrosis, which accounts for the increased numbers of activated HSCs in areas of inflammation during hepatic fibrosis. Currently, microRNAs have been found to play essential roles in HSC differentiation, proliferation, apoptosis, fat accumulation and collagen production. However, little is known about microRNA mediated HSC activation and migration. In this study, the miRNA expression profiles of quiescent HSCs, partially activated HSCs and fully activated HSCs were compared in pairs. Gene ontology (GO) and GO-Map network analysis indicated that the activation of HSCs was regulated by microRNAs. Among them miR-335 was confirmed to be significantly reduced during HSC activation by qRT-PCR, and restoring expression of miR-335 inhibited HSC migration and reduced {alpha}-SMA and collagen type I. Previous study revealed that tenascin-C (TNC), an extracellular matrix glycoprotein involved in cell migration, might be a target of miR-335. Therefore, we further studied the TNC expression in miR-335 over-expressed HSCs. Our data showed that exogenous TNC could enhance HSC migration in vitro and miR-335 restoration resulted in a significant inhibition of TNC expression. These results demonstrated that miR-335 restoration inhibited HSC migration, at least in part, via downregulating the TNC expression.

  5. Elevated Levels of Endocannabinoids in Chronic Hepatitis C May Modulate Cellular Immune Response and Hepatic Stellate Cell Activation

    Eleonora Patsenker

    2015-03-01

    Full Text Available The endocannabinoid (EC system is implicated in many chronic liver diseases, including hepatitis C viral (HCV infection. Cannabis consumption is associated with fibrosis progression in patients with chronic hepatitis C (CHC, however, the role of ECs in the development of CHC has never been explored. To study this question, anandamide (AEA and 2-arachidonoyl glycerol (2-AG were quantified in samples of HCV patients and healthy controls by gas and liquid chromatography mass spectrometry. Fatty acid amide hydrolase (FAAH and monoaclyglycerol lipase (MAGL activity was assessed by [3H]AEA and [3H]2-AG hydrolysis, respectively. Gene expression and cytokine release were assayed by TaqMan PCR and ELISpot, respectively. AEA and 2-AG levels were increased in plasma of HCV patients, but not in liver tissues. Hepatic FAAH and MAGL activity was not changed. In peripheral blood mononuclear cells (PBMC, ECs inhibited IFN-γ, TNF-α, and IL-2 secretion. Inhibition of IL-2 by endogenous AEA was stronger in PBMC from HCV patients. In hepatocytes, 2-AG induced the expression of IL-6, -17A, -32 and COX-2, and enhanced activation of hepatic stellate cells (HSC co-cultivated with PBMC from subjects with CHC. In conclusion, ECs are increased in plasma of patients with CHC and might reveal immunosuppressive and profibrogenic effects.

  6. Resveratrol Inhibits ROS-Promoted Activation and Glycolysis of Pancreatic Stellate Cells via Suppression of miR-21

    Bin Yan

    2018-01-01

    Full Text Available Activation of pancreatic stellate cells (PSCs initiates pancreatic fibrosis in chronic pancreatitis and furnishes a niche that enhances the malignancy of pancreatic cancer cells (PCCs in pancreatic ductal adenocarcinoma (PDAC. Resveratrol (RSV, a natural polyphenol, exhibits potent antioxidant and anticancer effects. However, whether and how RSV influences the biological properties of activated PSCs and the effects of these changes on tumor remain unknown. In the present study, we found that RSV impeded hydrogen peroxide-driven reactive oxygen species- (ROS- induced activation, invasion, migration, and glycolysis of PSCs. In addition, miR-21 expression in activated PSCs was downregulated after RSV treatment, whereas the PTEN protein level increased. miR-21 silencing attenuated ROS-induced activation, invasion, migration, and glycolysis of PSCs, whereas the overexpression of miR-21 rescued the responses of PSCs treated with RSV. Moreover, RSV or N-acetyl-L-cysteine (NAC administration or miR-21 knockdown in PSCs reduced the invasion and migration of PCCs in coculture, and the effects of RSV were partly reversed by miR-21 upregulation. Collectively, RSV inhibits PCC invasion and migration through suppression of ROS/miR-21-mediated activation and glycolysis in PSCs. Therefore, targeting miR-21-mediated glycolysis by RSV in tumor stroma may serve as a new strategy for clinical PDAC prevention or treatment.

  7. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases human hepatic stellate cell activation

    Harvey, Wendy A.; Jurgensen, Kimberly; Pu, Xinzhu; Lamb, Cheri L.; Cornell, Kenneth A.; Clark, Reilly J.; Klocke, Carolyn; Mitchell, Kristen A.

    2016-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a halogenated aromatic hydrocarbon that elicits toxicity through the aryl hydrocarbon receptor (AhR). In the liver, gross markers of TCDD toxicity are attributed to AhR activation in parenchymal hepatocytes. However, less is known regarding the consequences of TCDD treatment on non-parenchymal cells in the liver. Hepatic stellate cells (HSCs) are non-parenchymal cells that store vitamin A when quiescent. Upon liver injury, activated HSCs lose this storage ability and instead function in the development and maintenance of inflammation and fibrosis through the production of pro-inflammatory mediators and collagen type I. Reports that TCDD exposure disrupts hepatic retinoid homeostasis and dysregulates extracellular matrix remodeling in the liver led us to speculate that TCDD treatment may disrupt HSC activity. The human HSC line LX-2 was used to test the hypothesis that TCDD treatment directly activates HSCs. Results indicate that exposure to 10 nM TCDD almost Completely inhibited lipid droplet storage in LX-2 cells cultured with retinol and palmitic acid. TCDD treatment also increased LX-2 cell proliferation, expression of α-smooth muscle actin, and production of monocyte chemoattractant protein-1 (MCP-1), all of which are characteristics of activated HSCs. However, TCDD treatment had no effect on Col1a1 mRNA levels in LX-2 cells stimulated with the potent profibrogenic mediator, transforming growth factor-β. The TCDD-mediated increase in LX-2 cell proliferation, but not MCP-1 production, was abolished when phosphoinositide 3-kinase was inhibited. These results indicate that HSCs are susceptible to direct modulation by TCDD and that TCDD likely increases HSC activation through a multi-faceted mechanism.

  8. Long live the liver: immunohistochemical and stereological study of hepatocytes, liver sinusoidal endothelial cells, Kupffer cells and hepatic stellate cells of male and female rats throughout ageing.

    Marcos, Ricardo; Correia-Gomes, Carla

    2016-12-01

    Male/female differences in enzyme activity and gene expression in the liver are known to be attenuated with ageing. Nevertheless, the effect of ageing on liver structure and quantitative cell morphology remains unknown. Male and female Wistar rats aged 2, 6, 12 and 18 months were examined by means of stereological techniques and immunohistochemical tagging of hepatocytes (HEP), liver sinusoidal endothelial cells (LSEC), Kupffer cells (KC) and hepatic stellate cells (HSC) in order to assess the total number and number per gram of these cells throughout life. The mean cell volume of HEP and HSC, the lobular position and the collagen content of the liver were also evaluated with stereological techniques. The number per gram of HSC was similar for both genders and was maintained throughout ageing. The mean volume of HSC was also conserved but differences in the cell body and lobular location were observed. Statistically significant gender differences in HEP were noted in young rats (females had smaller and more binucleated HEP) but were attenuated with ageing. The same occurred for KC and LSEC, since the higher number per gram in young females disappeared in older animals. Liver collagen increased with ageing but only in males. Thus, the numbers of these four cell types are related throughout ageing, with well-defined cell ratios. The shape and lobular position of HSC change with ageing in both males and females. Gender dimorphism in HEP, KC and LSEC of young rat liver disappears with ageing.

  9. Hepatic Stellate Cell-Derived Microvesicles Prevent Hepatocytes from Injury Induced by APAP/H2O2

    Renwei Huang

    2016-01-01

    Full Text Available Hepatic stellate cells (HSCs, previously described for liver-specific mesenchymal stem cells (MSCs, appear to contribute to liver regeneration. Microvesicles (MVs are nanoscale membrane fragments, which can regulate target cell function by transferring contents from their parent cells. The aim of this study was to investigate the effect of HSC-derived MVs on xenobiotic-induced liver injury. Rat and human hepatocytes, BRL-3A and HL-7702, were used to build hepatocytes injury models by n-acetyl-p-aminophenol n-(APAP or H2O2 treatment. MVs were prepared from human and rat HSCs, LX-2, and HST-T6 and, respectively, added to injured BRL-3A and HL-7702 hepatocytes. MTT assay was utilized to determine cell proliferation. Cell apoptosis was analyzed by flow cytometry and hoechst33258 staining. Western blot was used for analyzing the expression of activated caspase-3. Liver injury indicators, alanine aminotransferase (ALT, aspartate aminotransferase (AST, and lactate dehydrogenase (LDH in culture medium were also assessed. Results showed that (1 HSC-MVs derived from LX-2 and HST-T6 were positive to CD90 and annexin V surface markers; (2 HSC-MVs dose-dependently improved the viability of hepatocytes in both injury models; (3 HSC-MVs dose-dependently inhibited the APAP/H2O2 induced hepatocytes apoptosis and activated caspase-3 expression and leakage of LDH, ALT, and AST. Our results demonstrate that HSC-derived MVs protect hepatocytes from toxicant-induced injury.

  10. Adenoviral overexpression of Lhx2 attenuates cell viability but does not preserve the stem cell like phenotype of hepatic stellate cells.

    Genz, Berit; Thomas, Maria; Pützer, Brigitte M; Siatkowski, Marcin; Fuellen, Georg; Vollmar, Brigitte; Abshagen, Kerstin

    2014-11-01

    Hepatic stellate cells (HSC) are well known initiators of hepatic fibrosis. After liver cell damage, HSC transdifferentiate into proliferative myofibroblasts, representing the major source of extracellular matrix in the fibrotic organ. Recent studies also demonstrate a role of HSC as progenitor or stem cell like cells in liver regeneration. Lhx2 is described as stem cell maintaining factor in different organs and as an inhibitory transcription factor in HSC activation. Here we examined whether a continuous expression of Lhx2 in HSC could attenuate their activation and whether Lhx2 could serve as a potential target for antifibrotic gene therapy. Therefore, we evaluated an adenoviral mediated overexpression of Lhx2 in primary HSC and investigated mRNA expression patterns by qRT-PCR as well as the activation status by different in vitro assays. HSC revealed a marked increase in activation markers like smooth muscle actin alpha (αSMA) and collagen 1α independent from adenoviral transduction. Lhx2 overexpression resulted in attenuated cell viability as shown by a slightly hampered migratory and contractile phenotype of HSC. Expression of stem cell factors or signaling components was also unaffected by Lhx2. Summarizing these results, we found no antifibrotic or stem cell maintaining effect of Lhx2 overexpression in primary HSC. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Ligustrazine attenuates oxidative stress-induced activation of hepatic stellate cells by interrupting platelet-derived growth factor-β receptor-mediated ERK and p38 pathways

    Zhang, Feng; Ni, Chunyan; Kong, Desong; Zhang, Xiaoping; Zhu, Xiaojing; Chen, Li; Lu, Yin; Zheng, Shizhong

    2012-01-01

    Hepatic fibrosis represents a frequent event following chronic insult to trigger wound healing reactions with accumulation of extracellular matrix (ECM) in the liver. Activation of hepatic stellate cells (HSCs) is the pivotal event during liver fibrogenesis. Compelling evidence indicates that oxidative stress is concomitant with liver fibrosis irrespective of the underlying etiology. Natural antioxidant ligustrazine exhibits potent antifibrotic activities, but the mechanisms are poorly understood. Our studies were to investigate the ligustrazine effects on HSC activation stimulated by hydrogen peroxide (H 2 O 2 ), an in vitro model mimicking the oxidative stress in liver fibrogenesis, and to elucidate the possible mechanisms. Our results demonstrated that H 2 O 2 at 5 μM significantly stimulated HSC proliferation and expression of marker genes of HSC activation; whereas ligustrazine dose-dependently suppressed proliferation and induced apoptosis in H 2 O 2 -activated HSCs, and attenuated expression of fibrotic marker genes. Mechanistic investigations revealed that ligustrazine reduced platelet-derived growth factor-β receptor (PDGF-βR) expression and blocked the phosphorylation of extracellular regulated protein kinase (ERK) and p38 kinase, two downstream effectors of PDGF-βR. Further molecular evidence suggested that ligustrazine interruption of ERK and p38 pathways was dependent on the blockade of PDGF-βR and might be involved in ligustrazine reduction of fibrotic marker gene expression under H 2 O 2 stimulation. Furthermore, ligustrazine modulated some proteins critical for HSC activation and ECM homeostasis in H 2 O 2 -stimulated HSCs. These data collectively indicated that ligustrazine could attenuate HSC activation caused by oxidative stress, providing novel insights into ligustrazine as a therapeutic option for hepatic fibrosis. Highlights: ► Ligustrazine inhibits oxidative stress-induced HSC activation. ► Ligustrazine reduces fibrotic marker genes

  12. The hop constituent xanthohumol exhibits hepatoprotective effects and inhibits the activation of hepatic stellate cells at different levels

    Ralf eWeiskirchen

    2015-05-01

    Full Text Available Xanthohumol is the principal prenylated flavonoid of the female inflorescences of the hop plant. In recent years, various beneficial xanthohumol effects including anti-inflammatory, antioxidant, hypoglycemic activities, and anticancer effects have been revealed. This review summarizes present studies indicating that xanthohumol also inhibits several critical pathophysiological steps during the development and course of chronic liver disease, including the activation and pro-fibrogenic genotype of hepatic stellate cells. Also the various mechanism of action and molecular targets of the beneficial xanthohumol effects will be described. Furthermore, the potential use of xanthohumol or a xanthohumol-enriched hop extract as therapeutic agent to combat the progression of chronic liver disease will be discussed. It is notable that in addition to its hepatoprotective effects, xanthohumol also holds promise as a therapeutic agent for treating obesity, dysregulation of glucose metabolism and other components of the metabolic syndrome including hepatic steatosis. Thus, therapeutic xanthohumol application appears as a promising strategy, particularly in obese patients, to inhibit the development as well as the progression of non-alcoholic fatty liver disease.

  13. Activation of TGF-β1-CD147 positive feedback loop in hepatic stellate cells promotes liver fibrosis.

    Li, Hai-Yan; Ju, Di; Zhang, Da-Wei; Li, Hao; Kong, Ling-Min; Guo, Yanhai; Li, Can; Wang, Xi-Long; Chen, Zhi-Nan; Bian, Huijie

    2015-11-12

    Activation of hepatic stellate cells (HSCs) by transforming growth factor-β1 (TGF-β1) initiates HBV-associated fibrogenesis. The mechanism of TGF-β1 modulating HSC activation is not fully uncovered. We hypothesized a positive feedback signaling loop of TGF-β1-CD147 promoting liver fibrogenesis by activation of HSCs. Human HSC cell line LX-2 and spontaneous liver fibrosis model derived from HBV transgenic mice were used to evaluate the activation of molecules in the signaling loop. Wound healing and cell contraction assay were performed to detect the CD147-overexpressed HSC migration and contraction. The transcriptional regulation of CD147 by TGF-β1/Smad4 was determined using dual-luciferase reporter assay and chromatin immunoprecipitation. We found that a positive reciprocal regulation between TGF-β1 and CD147 mediated HSC activation. CD147 over-expression promoted HSC migration and accelerated TGF-β1-induced cell contraction. Phosphorylation of Smad2 and Smad3 in cooperation with Smad4 mediated the TGF-β1-regulated CD147 expression. Smad4 activated the transcription by direct interaction with CD147 promoter. Meanwhile, CD147 modulated the activated phenotype of HSCs through the ERK1/2 and Sp1 which up-regulated α-SMA, collagen I, and TGF-β1 synthesis. These findings indicate that TGF-β1-CD147 loop plays a key role in regulating the HSC activation and combination of TGF-β receptor inhibitor and anti-CD147 antibody might be promised to reverse fibrogenesis.

  14. Distinct populations of hepatic stellate cells in the mouse liver have different capacities for retinoid and lipid storage.

    Diana N D'Ambrosio

    Full Text Available Hepatic stellate cell (HSC lipid droplets are specialized organelles for the storage of retinoid, accounting for 50-60% of all retinoid present in the body. When HSCs activate, retinyl ester levels progressively decrease and the lipid droplets are lost. The objective of this study was to determine if the HSC population in a healthy, uninjured liver demonstrates heterogeneity in its capacity for retinoid and lipid storage in lipid droplets. To this end, we utilized two methods of HSC isolation, which leverage distinct properties of these cells, including their vitamin A content and collagen expression. HSCs were isolated either from wild type (WT mice in the C57BL/6 genetic background by flotation in a Nycodenz density gradient, followed by fluorescence activated cell sorting (FACS based on vitamin A autofluorescence, or from collagen-green fluorescent protein (GFP mice by FACS based on GFP expression from a GFP transgene driven by the collagen I promoter. We show that GFP-HSCs have: (i increased expression of typical markers of HSC activation; (ii decreased retinyl ester levels, accompanied by reduced expression of the enzyme needed for hepatic retinyl ester synthesis (LRAT; (iii decreased triglyceride levels; (iv increased expression of genes associated with lipid catabolism; and (v an increase in expression of the retinoid-catabolizing cytochrome, CYP2S1.Our observations suggest that the HSC population in a healthy, uninjured liver is heterogeneous. One subset of the total HSC population, which expresses early markers of HSC activation, may be "primed" and ready for rapid response to acute liver injury.

  15. Oxidative stress and hepatic stellate cell activation are key events in arsenic induced liver fibrosis in mice

    Ghatak, Subhadip; Biswas, Ayan; Dhali, Gopal Krishna; Chowdhury, Abhijit; Boyer, James L.; Santra, Amal

    2011-01-01

    Arsenic is an environmental toxicant and carcinogen. Exposure to arsenic is associated with development of liver fibrosis and portal hypertension through ill defined mechanisms. We evaluated hepatic fibrogenesis after long term arsenic exposure in a murine model. BALB/c mice were exposed to arsenic by daily gavages of 6 μg/gm body weight for 1 year and were evaluated for markers of hepatic oxidative stress and fibrosis, as well as pro-inflammatory, pro-apoptotic and pro-fibrogenic factors at 9 and 12 months. Hepatic NADPH oxidase activity progressively increased in arsenic exposure with concomitant development of hepatic oxidative stress. Hepatic steatosis with occasional collection of mononuclear inflammatory cells and mild portal fibrosis were the predominant liver lesion observed after 9 months of arsenic exposure, while at 12 months, the changes included mild hepatic steatosis, inflammation, necrosis and significant fibrosis in periportal areas. The pathologic changes in the liver were associated with markers of hepatic stellate cells (HSCs) activation, matrix reorganization and fibrosis including α-smooth muscle actin, transforming growth factor-β1, PDGF-Rβ, pro-inflammatory cytokines and enhanced expression of tissue inhibitor of metalloproteinase-1 and pro(α) collagen type I. Moreover, pro-apoptotic protein Bax was dominantly expressed and Bcl-2 was down-regulated along with increased number of TUNEL positive hepatocytes in liver of arsenic exposed mice. Furthermore, HSCs activation due to increased hepatic oxidative stress observed after in vivo arsenic exposure was recapitulated in co-culture model of isolated HSCs and hepatocytes exposed to arsenic. These findings have implications not only for the understanding of the pathology of arsenic related liver fibrosis but also for the design of preventive strategies in chronic arsenicosis.

  16. Dihydroartemisinin counteracts fibrotic portal hypertension via farnesoid X receptor-dependent inhibition of hepatic stellate cell contraction.

    Xu, Wenxuan; Lu, Chunfeng; Zhang, Feng; Shao, Jiangjuan; Yao, Shunyu; Zheng, Shizhong

    2017-01-01

    Portal hypertension is a frequent pathological symptom occurring especially in hepatic fibrosis and cirrhosis. Current paradigms indicate that inhibition of hepatic stellate cell (HSC) activation and contraction is anticipated to be an attractive therapeutic strategy, because activated HSC dominantly facilitates an increase in intrahepatic vein pressure through secreting extracellular matrix and contracting. Our previous in vitro study indicated that dihydroartemisinin (DHA) inhibited contractility of cultured HSC by activating intracellular farnesoid X receptor (FXR). However, the effect of DHA on fibrosis-related portal hypertension still requires clarification. In this study, gain- and loss-of-function models of FXR in HSC were established to investigate the mechanisms underlying DHA protection against chronic CCl 4 -caused hepatic fibrosis and portal hypertension. Immunofluorescence staining visually showed a decrease in FXR expression in CCl 4 -administrated rat HSC but an increase in that in DHA-treated rat HSC. Serum diagnostics and morphological analyses consistently indicated that DHA exhibited hepatoprotective effects on CCl 4 -induced liver injury. DHA also reduced CCl 4 -caused inflammatory mediator expression and inflammatory cell infiltration. These improvements were further enhanced by INT-747 but weakened by Z-guggulsterone. Noteworthily, DHA, analogous to INT-747, significantly lowered portal vein pressure and suppressed fibrogenesis. Experiments on mice using FXR shRNA lentivirus consolidated the results above. Mechanistically, inhibition of HSC activation and contraction was found as a cellular basis for DHA to relieve portal hypertension. These findings demonstrated that DHA attenuated portal hypertension in fibrotic rodents possibly by targeting HSC contraction via a FXR activation-dependent mechanism. FXR could be a target molecule for reducing portal hypertension during hepatic fibrosis. © 2016 Federation of European Biochemical Societies.

  17. Hepatic stellate cell-targeted imatinib nanomedicine versus conventional imatinib: A novel strategy with potent efficacy in experimental liver fibrosis.

    El-Mezayen, Nesrine S; El-Hadidy, Wessam F; El-Refaie, Wessam M; Shalaby, Th I; Khattab, Mahmoud M; El-Khatib, Aiman S

    2017-11-28

    Liver fibrosis is a global health problem without approved treatment. Imatinib inhibits two key profibrotic pathways; platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-β) and thus can be used to treat liver fibrosis. However, conventional imatinib therapy is hampered by low concentration at target tissue and increased toxicity to other tissues especially heart, lung and liver. Since hepatic stellate cells (HSCs) are the main contributors to liver fibrosis pathogenesis and sole hepatic vitamin A (V A ) storage cells, they can be actively targeted by coupling liposomes to V A . In this study, novel V A -coupled imatinib-loaded liposomes (ILC) were prepared and optimized regarding V A -coupling efficiency, imatinib entrapment efficiency, and particle size. Preferential accumulation of the selected formula in liver was proved by tracing intraperitoneally (i.p.)-injected V A -coupled liposomes loaded with Nile Red (LCNR) to rats with CCl 4 -induced liver fibrosis using live animal imaging. Co-localization of LCNR with immunofluorescently-labeled PDGFR-β in frozen liver tissue sections confirmed HSCs targeting. ILC bio-distribution, following single i.p. injection, revealed 13.5 folds higher hepatic accumulation than conventional imatinib in addition to limited bio-distribution to other organs including heart and lung reflecting diminished adverse effects. ILC therapy resulted in a potent inhibition of phosphorylated PDGFR-β expression when compared to conventional imatinib. Subsequently, there was a statistically significant improvement in liver function tests and reversal of hepatotoxicity along with liver fibrosis. Anti-fibrotic effect was evident from histopathologic Ishak score reduction as well as normalization of the level of profibrotic mediators (hydroxyproline, TGF-B and matrix metalloproteinase-2). Thus, HSC-targeted imatinib therapy shows outstanding anti-fibrotic effects with reduced cytotoxicity compared to conventional

  18. Synapses between parallel fibres and stellate cells express long-term changes in synaptic efficacy in rat cerebellum.

    Rancillac, Armelle; Crépel, Francis

    2004-02-01

    Various forms of synaptic plasticity underlying motor learning have already been well characterized at cerebellar parallel fibre (PF)-Purkinje cell (PC) synapses. Inhibitory interneurones play an important role in controlling the excitability and synchronization of PCs. We have therefore tested the possibility that excitatory synapses between PFs and stellate cells (SCs) are also able to exhibit long-term changes in synaptic efficacy. In the present study, we show that long-term potentiation (LTP) and long-term depression (LTD) were induced at these synapses by a low frequency stimulation protocol (2 Hz for 60 s) and that pairing this low frequency stimulation protocol with postsynaptic depolarization induced a marked shift of synaptic plasticity in favour of LTP. This LTP was cAMP independent, but required nitric oxide (NO) production from pre- and/or postsynaptic elements, depending on the stimulation or pairing protocol used, respectively. In contrast, LTD was not dependent on NO production but it required activation of postsynaptic group II and possibly of group I metabotropic glutamate receptors. Finally, stimulation of PFs at 8 Hz for 15 s also induced LTP at PF-SC synapses. But in this case, LTP was cAMP dependent, as was also observed at PF-PC synapses for presynaptic LTP induced in the same conditions. Thus, long-term changes in synaptic efficacy can be accomplished by PF-SCs synapses as well as by PF-PC synapses, suggesting that both types of plasticity might co-operate during cerebellar motor learning.

  19. Rosmarinic acid counteracts activation of hepatic stellate cells via inhibiting the ROS-dependent MMP-2 activity: Involvement of Nrf2 antioxidant system

    Lu, Changfang; Zou, Yu; Liu, Yuzhang; Niu, Yingcai

    2017-01-01

    Recently, oxidative stress is involved in hepatofibrogenesis. Matrix metalloproteinase-2 (MMP-2) is required for activation of hepatic stellate cells (HSCs) in response to reactive oxygen species (ROS). This study was designed to explore the hypothesis that the inhibitory effect of rosmarinic acid (RA) on HSCs activation might mainly result from its antioxidant capability by increasing the synthesis of glutathione (GSH) involved in nuclear factor kappa B (NF-κB)-dependent inhibition of MMP-2 activity. Here, we demonstrate that RA reverses activated HSCs to quiescent cells. Concomitantly, RA inhibits MMP-2 activity. RNA interference-imposed knockdown of NF-κB abolished down-regulation of MMP-2 by RA. RA-mediated inactivation of NF-κB could be blocked by the diphenyleneiodonium chloride (DPI; a ROS inhibitor). Conversely, transfection of dominant-negative (DN) mutant of extracellular signal-regulated kinases 2 (ERK2), c-Jun N-terminal kinase 1 (JNK1), or p38α kinase had no such effect. Simultaneously, RA suppresses ROS generation and lipid peroxidation (LPO) whereas increases cellular GSH in HSC-T6 cells. Furthermore, RA significantly increased antioxidant response element (ARE)-mediated luciferase activity, nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and catalytic subunits from glutamate cysteine ligase (GCLc) expression, but not modulatory subunits from GCL (GCLm). RA-mediated up-regulation of GClc is inhibited by the shRNA-induced Nrf2 knockdown. The knocking down of Nrf2 or buthionine sulfoximine (a GCL inhibitor) abolished RA-mediated inhibition of ROS. Collectively, these results provide novel insights into the mechanisms of RA as an antifibrogenic candidate in the prevention and treatment of liver fibrosis. - Highlights: • RA reverses activated HSCs to quiescent cells. • RA suppresses MMP-2 activity through a NF-κB-dependent pathway. • Inhibition of oxidative stress by RA is dependent on nuclear translocation of Nrf2

  20. Rosmarinic acid counteracts activation of hepatic stellate cells via inhibiting the ROS-dependent MMP-2 activity: Involvement of Nrf2 antioxidant system

    Lu, Changfang; Zou, Yu; Liu, Yuzhang; Niu, Yingcai, E-mail: nyc1968@126.com

    2017-03-01

    Recently, oxidative stress is involved in hepatofibrogenesis. Matrix metalloproteinase-2 (MMP-2) is required for activation of hepatic stellate cells (HSCs) in response to reactive oxygen species (ROS). This study was designed to explore the hypothesis that the inhibitory effect of rosmarinic acid (RA) on HSCs activation might mainly result from its antioxidant capability by increasing the synthesis of glutathione (GSH) involved in nuclear factor kappa B (NF-κB)-dependent inhibition of MMP-2 activity. Here, we demonstrate that RA reverses activated HSCs to quiescent cells. Concomitantly, RA inhibits MMP-2 activity. RNA interference-imposed knockdown of NF-κB abolished down-regulation of MMP-2 by RA. RA-mediated inactivation of NF-κB could be blocked by the diphenyleneiodonium chloride (DPI; a ROS inhibitor). Conversely, transfection of dominant-negative (DN) mutant of extracellular signal-regulated kinases 2 (ERK2), c-Jun N-terminal kinase 1 (JNK1), or p38α kinase had no such effect. Simultaneously, RA suppresses ROS generation and lipid peroxidation (LPO) whereas increases cellular GSH in HSC-T6 cells. Furthermore, RA significantly increased antioxidant response element (ARE)-mediated luciferase activity, nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and catalytic subunits from glutamate cysteine ligase (GCLc) expression, but not modulatory subunits from GCL (GCLm). RA-mediated up-regulation of GClc is inhibited by the shRNA-induced Nrf2 knockdown. The knocking down of Nrf2 or buthionine sulfoximine (a GCL inhibitor) abolished RA-mediated inhibition of ROS. Collectively, these results provide novel insights into the mechanisms of RA as an antifibrogenic candidate in the prevention and treatment of liver fibrosis. - Highlights: • RA reverses activated HSCs to quiescent cells. • RA suppresses MMP-2 activity through a NF-κB-dependent pathway. • Inhibition of oxidative stress by RA is dependent on nuclear translocation of Nrf2

  1. Two dynamic morphotypes of sarcoma cells, asymmetric stellate and triangle with leading lamella, are related to malignancy

    Pokorná, Eva; Zicha, D.; Chaloupková, Alena; Matoušková, Eva; Veselý, Pavel

    2003-01-01

    Roč. 49, č. 1 (2003), s. 33-49 ISSN 0015-5500 R&D Projects: GA ČR GA304/99/0368 Institutional research plan: CEZ:AV0Z5052915 Keywords : morphotypes * stellate * lamella Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.527, year: 2003

  2. Gene expression profiling and secretome analysis differentiate adult-derived human liver stem/progenitor cells and human hepatic stellate cells.

    Silvia Berardis

    Full Text Available Adult-derived human liver stem/progenitor cells (ADHLSC are obtained after primary culture of the liver parenchymal fraction. The cells are of fibroblastic morphology and exhibit a hepato-mesenchymal phenotype. Hepatic stellate cells (HSC derived from the liver non-parenchymal fraction, present a comparable morphology as ADHLSC. Because both ADHLSC and HSC are described as liver stem/progenitor cells, we strived to extensively compare both cell populations at different levels and to propose tools demonstrating their singularity. ADHLSC and HSC were isolated from the liver of four different donors, expanded in vitro and followed from passage 5 until passage 11. Cell characterization was performed using immunocytochemistry, western blotting, flow cytometry, and gene microarray analyses. The secretion profile of the cells was evaluated using Elisa and multiplex Luminex assays. Both cell types expressed α-smooth muscle actin, vimentin, fibronectin, CD73 and CD90 in accordance with their mesenchymal origin. Microarray analysis revealed significant differences in gene expression profiles. HSC present high expression levels of neuronal markers as well as cytokeratins. Such differences were confirmed using immunocytochemistry and western blotting assays. Furthermore, both cell types displayed distinct secretion profiles as ADHLSC highly secreted cytokines of therapeutic and immuno-modulatory importance, like HGF, interferon-γ and IL-10. Our study demonstrates that ADHLSC and HSC are distinct liver fibroblastic cell populations exhibiting significant different expression and secretion profiles.

  3. Stellate ganglion blockade for analgesia following upper limb surgery.

    McDonnell, J G

    2012-01-31

    We report the successful use of a stellate ganglion block as part of a multi-modal postoperative analgesic regimen. Four patients scheduled for orthopaedic surgery following upper limb trauma underwent blockade of the stellate ganglion pre-operatively under ultrasound guidance. Patients reported excellent postoperative analgesia, with postoperative VAS pain scores between 0 and 2, and consumption of morphine in the first 24 h ranging from 0 to 14 mg. While these are preliminary findings, and must be confirmed in a clinical trial, they highlight the potential for stellate ganglion blockade to provide analgesia following major upper limb surgery.

  4. PHP14 regulates hepatic stellate cells migration in liver fibrosis via mediating TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway.

    Xu, Anjian; Li, Yanmeng; Zhao, Wenshan; Hou, Fei; Li, Xiaojin; Sun, Lan; Chen, Wei; Yang, Aiting; Wu, Shanna; Zhang, Bei; Yao, Jingyi; Wang, Huan; Huang, Jian

    2018-02-01

    Hepatic fibrosis is characterized by the activation of hepatic stellate cells (HSCs). Migration of the activated HSCs to the site of injury is one of the key characteristics during the wound healing process. We have previously demonstrated that 14 kDa phosphohistidine phosphatase (PHP14) is involved in migration and lamellipodia formation of HSCs. However, the role of PHP14 in liver fibrosis remains unknown. In this study, we first assessed PHP14 expression and distribution in liver fibrotic tissues using western blot, immunohistochemistry, and double immunofluorescence staining. Next, we investigated the role of PHP14 in liver fibrosis and, more specifically, the migration of HSCs by Transwell assay and 3D collagen matrices assay. Finally, we explored the possible molecular mechanisms of the effects of PHP14 on these processes. Our results show that the PHP14 expression is up-regulated in fibrotic liver and mainly in HSCs. Importantly, TGF-β1 can induce PHP14 expression in HSCs accompanied with the activation of HSCs. Consistent with the previous study, PHP14 promotes HSCs migration, especially, promotes 3D floating collagen matrices contraction but inhibits stressed-released matrices contraction. Mechanistically, the PI3Kγ/AKT/Rac1 pathway is involved in migration regulated by PHP14. Moreover, PHP14 specifically mediates the TGF-β1 signaling to PI3Kγ/AKT pathway and regulates HSC migration, and thus participates in liver fibrosis. Our study identified the role of PHP14 in liver fibrosis, particularly HSC migration, and suggested a novel mediator of transducting TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway. PHP14 is up-regulated in fibrotic liver and activated hepatic stellate cells. The expression of PHP14 is induced by TGF-β1. The migration of hepatic stellate cells is regulated by PHP14. PHP14 is a mediator of TGF-β1 signaling to PI3Kγ/AKT/Rac1 pathway in hepatic stellate cells.

  5. L-Cysteine Administration Attenuates Pancreatic Fibrosis Induced by TNBS in Rats by Inhibiting the Activation of Pancreatic Stellate Cell

    Hu, GuoYong; Shen, Jie; Wang, Feng; Xu, Ling; Dai, WeiQi; Xiong, Jie; Ni, JianBo; Guo, ChuanYong; Wan, Rong; Wang, XingPeng

    2012-01-01

    Background and Aims Recent studies have shown that activated pancreatic stellate cells (PSCs) play a major role in pancreatic fibrogenesis. We aimed to study the effect of L-cysteine administration on fibrosis in chronic pancreatitis (CP) induced by trinitrobenzene sulfonic acid (TNBS) in rats and on the function of cultured PSCs. Methods CP was induced by TNBS infusion into rat pancreatic ducts. L-cysteine was administrated for the duration of the experiment. Histological analysis and the contents of hydroxyproline were used to evaluate pancreatic damage and fibrosis. Immunohistochemical analysis of α-SMA in the pancreas was performed to detect the activation of PSCs in vivo. The collagen deposition related proteins and cytokines were determined by western blot analysis. DNA synthesis of cultured PSCs was evaluated by BrdU incorporation. We also evaluated the effect of L-cysteine on the cell cycle and cell activation by flow cytometry and immunocytochemistry. The expression of PDGFRβ, TGFβRII, collagen 1α1 and α-SMA of PSCs treated with different concentrations of L-cysteine was determined by western blot. Parameters of oxidant stress were evaluated in vitro and in vivo. Nrf2, NQO1, HO-1, IL-1β expression were evaluated in pancreas tissues by qRT-PCR. Results The inhibition of pancreatic fibrosis by L-cysteine was confirmed by histological observation and hydroxyproline assay. α-SMA, TIMP1, IL-1β and TGF-β1 production decreased compared with the untreated group along with an increase in MMP2 production. L-cysteine suppressed the proliferation and extracellular matrix production of PSCs through down-regulating of PDGFRβ and TGFβRII. Concentrations of MDA+4-HNE were decreased by L-cysteine administration along with an increase in GSH levels both in tissues and cells. In addition, L-cysteine increased the mRNA expression of Nrf2, NQO1 and HO-1 and reduced the expression of IL-1β in L-cysteine treated group when compared with control group. Conclusion L

  6. Raman imaging and lipidomic analysis of lipid droplets in (activated) hepatic stellate cells

    Vaandrager, A.B.; Testerink, N.; Ajat, M.; Houweling, M.; Brouwers, J.F.H.M.; Pully, V.V.; van Manen, H.J.; Otto, Cornelis; Helms, J.B.

    2009-01-01

    In eukaryotic cells the excess of hydrophobic molecules is stored in special organelles named lipid droplets (LDs). These droplets contain triacylglycerides, cholesteryl esters and/or retinyl esters, depending on the function of the cell in which they reside. Retinyl esters, the storage form of

  7. Targeting of the P2X7 receptor in pancreatic cancer and stellate cells

    Giannuzzo, Andrea; Saccomano, Mara; Napp, Joanna

    2016-01-01

    of PDAC. In the in vitro studies we show that human PDAC cells with luciferase gene (PancTu-1 Luc cells) express high levels of P2X7R protein. Allosteric P2X7R antagonist AZ10606120 inhibited cell proliferation in basal conditions, indicating that P2X7R was tonically active. Extracellular ATP and Bz......ATP, to which the P2X7R is more sensitive, further affected cell survival and confirmed complex functionality of P2X7R. PancTu-1 Luc migration and invasion was reduced by AZ10606120, and it was stimulated by PSCs, but not by PSCs from P2X7(-/-) animals. PancTu-1 Luc cells were orthotopically transplanted...

  8. Liver cirrhosis and hepatic stellate cells Cirrose hepática e células estreladas do figado

    Daniel Ferracioli Brandão

    2006-01-01

    Full Text Available The cirrhosis represents the final stage of several chronic hepatic diseases and it is characterized by the presence of fibrosis and morphologic conversion from the normal hepatic architecture into structurally abnormal nodules. In the evolution of the disease there is loss of the normal vascular relationship and portal hypertension. There are also regenerative hepatocelular alterations that become more prominent with the progression of the disease. The liver transplantation continues to be the only therapeutic option in cases of disease in terminal phase. The hepatic stellate cells (HSC are perisinusoidal cells that store vitamin A and produce growth factors, citocins, prostaglandins and other bioactive substances. They can suffer an activation process that convert them to cells with a phenotype similar to myofibroblasts. When activated, they present increased capacity of proliferation, mobility, contractility and synthesis of collagen and other components of extracelular matrix. They possess cytoplasmic processes adhered to sinusoids and can affect the sinusoidal blood flow. HSC are important in pathogenesis of fibrosis and portal hypertension.A cirrose representa o estágio final de diversas doenças hepáticas crônicas e é caracterizada pela presença de fibrose e conversão da arquitetura hepática normal em nódulos estruturalmente anormais. Na evolução da doença ocorre perda da relação vascular normal e hipertensão portal. Há também alterações regenerativas hepatocelulares que se tornam mais proeminentes com a progressão da doença. O transplante hepático permanece como a única opção terapêutica nos casos de doença em fase terminal. As células estreladas hepáticas (CEH são células perisinusoidais que armazenam vitamina A e produzem fatores de crescimento, citocinas, prostaglandinas e outras substâncias bioativas. Podem sofrer um processo de ativação para um fenótipo semelhante a miofibroblastos. Quando ativadas

  9. Hepatic stellate cells and alcoholic liver disease Células estrelladas hepáticas y hepatopatía alcohólica

    M. Vera

    2006-09-01

    Full Text Available Liver fibrosis represents a significant health problem worldwide for which no effective therapy exists. A great deal of research has been carried out to understand the molecular mechanisms responsible for the development of liver fibrosis. Activated stellate cells are the primary cell type responsible for the production of collagen I, the key protein involved in the development of liver fibrosis. Excessive deposition of collagen I occurs along with impaired extracellular matrix remodeling. Following a fibrogenic stimulus stellate cells transform into an activated collagen type I-producing cell. Numerous changes in gene expression are associated with stellate cell activation, including the induction of several intracellular signaling cascades, which help maintain the activated phenotype and control the fibrogenic and proliferative state of the cell. Activation of stellate cells is mediated by factors released from hepatocytes and Kupffer cells as they produce reactive oxygen species, nitric oxide, cytokines, growth factors, and cyclooxygenase and lipoxygenase metabolites, which provide pivotal paracrine effects in the liver milieu. Inhibition of stellate cell activation, proliferation, and the increased production of extracellular matrix (i.e. collagen type I are therefore crucial steps for intervention in hepatic fibrogenesis.La fibrosis hepática es un importante problema de salud en todo el mundo para el que no hay tratamiento efectivo. Se han realizado muchas investigaciones para comprender los mecanismos moleculares que son responsables del desarrollo de la fibrosis hepática. Las células estrelladas activadas son el principal tipo celular responsable de la producción de colágeno I, la proteína clave implicada en el desarrollo de la fibrosis hepática. Se desarrolla en excesivos depósitos de colágeno I junto con un deterioro del remodelado de la matriz extracelular. Tras un estímulo fibrogénico, las células estrelladas se

  10. Early stellate cell activation and veno-occlusive-disease (VOD)-like hepatotoxicity in dogs treated with AR-H047108, an imidazopyridine proton pump inhibitor.

    Berg, Anna-Lena; Böttcher, Gerhard; Andersson, Kjell; Carlsson, Enar; Lindström, Anna-Karin; Huby, Russell; Håkansson, Helen; Skånberg-Wilhelmsson, Inger; Hellmold, Heike

    2008-07-01

    Dogs treated with AR-H047108, an imidazopyridine potassium competitive acid blocker (P-CAB), developed clinical signs of hepatic dysfunction as well as morphologically manifest hepatotoxicity in repeat-dose toxicity studies. An investigative one-month study was performed, with interim euthanasia after one and two weeks. A detailed histopathological and immunohistochemical characterization of the liver lesions was conducted, including markers for fibrosis, Kupffer cell activation, apoptosis, and endothelial injury. In addition, hepatic retinoid and procollagen 1alpha2 mRNA levels in livers of dogs treated with AR-H047108 were analyzed. The results showed an early inflammatory process in central veins and centrilobular areas, present after one week of treatment. This inflammatory reaction was paralleled by activation of stellate/Ito cells to myofibroblasts and was associated with sinusoidal and centrivenular fibrosis. The early activation of stellate cells coincided with a significant decrease in retinyl ester levels, and a significant increase in procollagen 1alpha2 mRNA levels, in the liver. At later time points (three and six months), there was marked sinusoidal fibrosis in centrilobular areas, as well as occlusion of central veins resulting from a combination of fibrosis and increased thickness of smooth muscle bundles in the vessel wall. The pattern of lesions suggests a veno-occlusive-disease (VOD)-like scenario, possibly linked to the imidazopyridine chemical structure of the compound facilitated by specific morphological features of the dog liver.

  11. In vitro structure-toxicity relationship of chalcones in human hepatic stellate cells

    Zenger, Katharina; Dutta, Subhajit; Wolff, Horst; Genton, Marc G.; Kraus, Birgit

    2015-01-01

    Xanthohumol (XN), the major prenylated chalcone from hops (Humulus lupulus L.), has received much attention within the last years, due to its multiple pharmacological activities including anti-proliferative, anti-inflammatory, antioxidant, pro-apoptotic, anti-bacterial and anti-adhesive effects. However, there exists a huge number of metabolites and structurally-related chalcones, which can be expected, or are already known, to exhibit various effects on cells. We have therefore analyzed the effects of XN and 18 other chalcones in a panel, consisting of multiple cell-based assays. Readouts of these assays addressed distinct aspects of cell-toxicity, like proliferation, mitochondrial health, cell cycle and other cellular features. Besides known active structural elements of chalcones, like the Michael system, we have identified several moieties that seem to have an impact on specific effects and toxicity in human liver cells in vitro. Based on these observations, we present a structure-toxicity model, which will be crucial to understand the molecular mechanisms of wanted effects and unwanted side-effects of chalcones.

  12. In vitro structure-toxicity relationship of chalcones in human hepatic stellate cells.

    Zenger, Katharina; Dutta, Subhajit; Wolff, Horst; Genton, Marc G; Kraus, Birgit

    2015-10-02

    Xanthohumol (XN), the major prenylated chalcone from hops (Humulus lupulus L.), has received much attention within the last years, due to its multiple pharmacological activities including anti-proliferative, anti-inflammatory, antioxidant, pro-apoptotic, anti-bacterial and anti-adhesive effects. However, there exists a huge number of metabolites and structurally-related chalcones, which can be expected, or are already known, to exhibit various effects on cells. We have therefore analyzed the effects of XN and 18 other chalcones in a panel, consisting of multiple cell-based assays. Readouts of these assays addressed distinct aspects of cell-toxicity, like proliferation, mitochondrial health, cell cycle and other cellular features. Besides known active structural elements of chalcones, like the Michael system, we have identified several moieties that seem to have an impact on specific effects and toxicity in human liver cells in vitro. Based on these observations, we present a structure-toxicity model, which will be crucial to understand the molecular mechanisms of wanted effects and unwanted side-effects of chalcones. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. In vitro structure-toxicity relationship of chalcones in human hepatic stellate cells

    Zenger, Katharina

    2015-07-19

    Xanthohumol (XN), the major prenylated chalcone from hops (Humulus lupulus L.), has received much attention within the last years, due to its multiple pharmacological activities including anti-proliferative, anti-inflammatory, antioxidant, pro-apoptotic, anti-bacterial and anti-adhesive effects. However, there exists a huge number of metabolites and structurally-related chalcones, which can be expected, or are already known, to exhibit various effects on cells. We have therefore analyzed the effects of XN and 18 other chalcones in a panel, consisting of multiple cell-based assays. Readouts of these assays addressed distinct aspects of cell-toxicity, like proliferation, mitochondrial health, cell cycle and other cellular features. Besides known active structural elements of chalcones, like the Michael system, we have identified several moieties that seem to have an impact on specific effects and toxicity in human liver cells in vitro. Based on these observations, we present a structure-toxicity model, which will be crucial to understand the molecular mechanisms of wanted effects and unwanted side-effects of chalcones.

  14. Identification of markers for quiescent pancreatic stellate cells in the normal human pancreas

    Nielsen, Michael Friberg Bruun; Mortensen, Michael Bau; Detlefsen, Sönke

    2017-01-01

    cells in the normal human pancreas and perisinusoidal cells in the normal human liver. The immunolabelling capacity was evaluated according to a semiquantitative scoring system. Double-IF of the markers of interest together with markers for other periacinar cells was performed. Moreover, the utility...... of histochemical stains for the identification of human qPSCs was examined, and their ultrastructure was revisited by electron microscopy. Adipophilin, CRBP-1, cytoglobin and vinculin were expressed in qHSCs in the liver, whereas cytoglobin and adipophilin were expressed in qPSCs in the pancreas. Adipophilin...... are markers of qPSCs in the normal human pancreas. However, the use of adipophilin as a qPSC marker may be limited due to its high dependence on optimal PATI. Cytoglobin, on the other hand, is a sensitive marker for qPSCs but is expressed in FBs as well....

  15. Profile of MMP and TIMP Expression in Human Pancreatic Stellate Cells: Regulation by IL-1α and TGFβ and Implications for Migration of Pancreatic Cancer Cells

    Vegard Tjomsland

    2016-07-01

    Full Text Available Pancreatic ductal adenocarcinoma is characterized by a prominent fibroinflammatory stroma with both tumor-promoting and tumor-suppressive functions. The pancreatic stellate cell (PSC is the major cellular stromal component and the main producer of extracellular matrix proteins, including collagens, which are degraded by metalloproteinases (MMPs. PSCs interact with cancer cells through various factors, including transforming growth factor (TGFβ and interleukin (IL-1α. The role of TGFβ in the dual nature of tumor stroma, i.e., protumorigenic or tumor suppressive, is not clear. We aimed to investigate the roles of TGFβ and IL-1α in the regulation of MMP profiles in PSCs and the subsequent effects on cancer cell migration. Human PSCs isolated from surgically resected specimens were cultured in the presence of pancreatic cancer cell lines, as well as IL-1α or TGFβ. MMP production and activities in PSCs were quantified by gene array transcripts, mRNA measurements, fluorescence resonance energy transfer–based activity assay, and zymography. PSC-conditioned media and pancreatic cancer cells were included in a collagen matrix cell migration model. We found that production of IL-1α by pancreatic cancer cells induced alterations in MMP and tissue inhibitors of matrix metalloproteinase (TIMP profiles and activities in PSCs, upregulated expression and activation of MMP1 and MMP3, and enhanced migration of pancreatic cancer cells in the collagen matrix model. TGFβ counteracted the effects of IL-1α on PSCs, reestablished PSC MMP and TIMP profiles and activities, and inhibited migration of cancer cells. This suggests that tumor TGFβ has a role as a suppressor of stromal promotion of tumor progression through alterations in PSC MMP profiles with subsequent inhibition of pancreatic cancer cell migration.

  16. Stellate Ganglion Block, Compared With Xenon Light Irradiation, Is a More Effective Treatment of Neurosensory Deficits Resulting From Orthognathic Surgery, as Measured by Current Perception Threshold.

    Nogami, Kentaro; Taniguchi, Shogo

    2015-07-01

    The aim of this study was to evaluate the relative effectiveness of stellate ganglion blockade (SGB) versus xenon light irradiation (XLI) for the treatment of neurosensory deficits resulting from orthognathic surgery as determined by a comparison of prospective measurements of electrical current perception thresholds (CPTs) and ranged CPTs (R-CPTs). CPT and R-CPT in the mental foramen area were measured during electrical stimulation at 98 different sites on the body in patients who had undergone orthognathic surgery. After surgery, patients were assigned to the SGB group or the XLI group. CPT and R-CPT of the 2 groups were measured at stimulation frequencies of 2,000, 250, and 5 Hz before surgery, 1 week after surgery, and after 10 treatment sessions. Furthermore, the influence of surgical factors, such as genioplasty and a surgically exposed inferior alveolar nerve (IAN), was examined in the 2 groups. Patients' CPT and R-CPT values indicated a considerable amount of sensory disturbance in most cases after surgery. The change in magnitude of all CPT and R-CPT values for the SGB group decreased considerably compared with that for the XLI group after treatment. There was no correlation between CPT or R-CPT values and surgical factors (eg, genioplasty and exposure of the IAN). SGB of the IAN could be an effective method for treating neurosensory deficits after orthognathic surgery on the IAN. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  17. Thymosin-β4 (Tβ4) Blunts PDGF-Dependent Phosphorylation and Binding of AKT to Actin in Hepatic Stellate Cells

    Reyes-Gordillo, Karina; Shah, Ruchi; Popratiloff, Anastas; Fu, Sidney; Hindle, Anna; Brody, Frederick; Rojkind, Marcos

    2011-01-01

    Hepatic stellate cell transdifferentiation is a key event in the fibrogenic cascade. Therefore, attempts to prevent and/or revert the myofibroblastic phenotype could result in novel therapeutic approaches to treat liver cirrhosis. The expression of platelet-derived growth factor (PDGF)-β receptor and the proliferative response to platelet-derived growth factor-ββ (PDGF-ββ) are hallmarks of the transdifferentiation of hepatic stellate cells (HSC). In this communication, we investigated whether thymosin-β4 (Tβ4), a chemokine expressed by HSC could prevent PDGF-BB-mediated proliferation and migration of cultured HSC. Using early passages of human HSC, we showed that Tβ4 inhibited cell proliferation and migration and prevented the expression of PDGF-β receptor (PDGF-βr), α-smooth muscle actin and α1(I) collagen mRNAs. Tβ4 also inhibited the reappearance of PDGF-βr after its PDGF-BB-dependent degradation. These PDGF-dependent events were associated with the inhibition of AKT phosphorylation at both T308 and S473 amino acid residues. The lack of AKT phosphorylation was not due to the inhibition of PDGF-βr phosphorylation, the activation of phosphoinositide 3-kinase (PI3K), pyruvate dehydrogenase kinase isozyme 1 (PDK1), and mammalian target of rapamycin (mTOR). We found that PDGF-BB induced AKT binding to actin, and that Tβ4 prevented this effect. Tβ4 also prevented the activation of freshly isolated HSC cultured in the presence of Dulbecco's modified Eagle's medium or Dulbecco's minimal essential medium containing 10% fetal bovine serum. In conclusion, overall, our findings suggest that Tβ4 by sequestering actin prevents binding of AKT, thus inhibiting its phosphorylation. Therefore, Tβ4 has the potential to be an antifibrogenic agent. PMID:21514425

  18. TGF-β1-elevated TRPM7 channel regulates collagen expression in hepatic stellate cells via TGF-β1/Smad pathway

    Fang, Ling, E-mail: fangling_1984@126.com [School of Pharmacy, Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Institute for Liver Diseases of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Mei Shan Road, Hefei, Anhui Province 230032 (China); The First Affiliated Hospital of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Huang, Cheng; Meng, Xiaoming; Wu, Baoming; Ma, Taotao; Liu, Xuejiao; Zhu, Qian [School of Pharmacy, Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Institute for Liver Diseases of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Mei Shan Road, Hefei, Anhui Province 230032 (China); Zhan, Shuxiang [School of Pharmacy, Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Institute for Liver Diseases of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Mei Shan Road, Hefei, Anhui Province 230032 (China); The First Affiliated Hospital of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Li, Jun, E-mail: lj@ahmu.edu.cn [School of Pharmacy, Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Institute for Liver Diseases of Anhui Medical University, Mei Shan Road, Hefei, Anhui Province 230032 (China); Key Laboratory of Anti-inflammatory and Immune Medicine, Anhui Medical University, Ministry of Education, Mei Shan Road, Hefei, Anhui Province 230032 (China)

    2014-10-15

    Transdifferentiation of hepatic stellate cells (HSCs) into myofibroblasts plays a critical role in the development of liver fibrosis, since myofibroblasts are the key cells responsible for excessive deposition of ECM proteins. Transient receptor potential melastatin 7 (TRPM7), a non-selective cation channel with protein serine/threonine kinase activity, has been demonstrated to function in the proliferation of activated HSCs. Here, we investigated the functional role of TRPM7 in collagen deposition in activated HSC-T6 cells (a rat hepatic stellate cell line). TRPM7 mRNA and protein were measured by Real-time PCR and Western blot in TGF-β1-activated HSC-T6 cells in vitro. Results demonstrated that TRPM7 protein was dramatically increased in fibrotic human livers. Stimulation of HSC-T6 cells with TGF-β1 increased TRPM7 mRNA and protein level in a time-dependent manner. Nevertheless, TGF-β1-elicited upregulation of TRPM7 in HSC-T6 cells was abrogated by SB431542 (TGF-β1 receptor blocker) or SIS3 (inhibitor of Smad3 phosphorylation). Additionally, blockade of TRPM7 channels with non-specific TRPM7 blocker 2-APB or synthetic siRNA targeting TRPM7 attenuated TGF-β1-induced expression of myofibroblast markers, as measured by the induction of α-SMA and Col1α1. Silencing TRPM7 also increased the ratio of MMPs/TIMPs by increasing MMP-13 expression and decreasing TIMP-1 and TIMP-2 levels. Strikingly, phosphorylation of p-Smad2 and p-Smad3, associated with collagen production, was decreased in TRPM7 deficient HSC-T6 cells. These observations suggested that TGF-β1 elevates TRPM7 expression in HSCs via Smad3-dependant mechanisms, which in turn contributes Smad protein phosphorylation, and subsequently increases fibrous collagen expression. Therefore, TRPM7 may constitute a useful target for the treatment of liver fibrosis. - Highlights: • Upregulation of TRPM7 protein in human fibrotic livers • Upregulation of TRPM7 by TGF-β1 elicited Smad signaling in HSC-T6 cells

  19. TGF-β1-elevated TRPM7 channel regulates collagen expression in hepatic stellate cells via TGF-β1/Smad pathway

    Fang, Ling; Huang, Cheng; Meng, Xiaoming; Wu, Baoming; Ma, Taotao; Liu, Xuejiao; Zhu, Qian; Zhan, Shuxiang; Li, Jun

    2014-01-01

    Transdifferentiation of hepatic stellate cells (HSCs) into myofibroblasts plays a critical role in the development of liver fibrosis, since myofibroblasts are the key cells responsible for excessive deposition of ECM proteins. Transient receptor potential melastatin 7 (TRPM7), a non-selective cation channel with protein serine/threonine kinase activity, has been demonstrated to function in the proliferation of activated HSCs. Here, we investigated the functional role of TRPM7 in collagen deposition in activated HSC-T6 cells (a rat hepatic stellate cell line). TRPM7 mRNA and protein were measured by Real-time PCR and Western blot in TGF-β1-activated HSC-T6 cells in vitro. Results demonstrated that TRPM7 protein was dramatically increased in fibrotic human livers. Stimulation of HSC-T6 cells with TGF-β1 increased TRPM7 mRNA and protein level in a time-dependent manner. Nevertheless, TGF-β1-elicited upregulation of TRPM7 in HSC-T6 cells was abrogated by SB431542 (TGF-β1 receptor blocker) or SIS3 (inhibitor of Smad3 phosphorylation). Additionally, blockade of TRPM7 channels with non-specific TRPM7 blocker 2-APB or synthetic siRNA targeting TRPM7 attenuated TGF-β1-induced expression of myofibroblast markers, as measured by the induction of α-SMA and Col1α1. Silencing TRPM7 also increased the ratio of MMPs/TIMPs by increasing MMP-13 expression and decreasing TIMP-1 and TIMP-2 levels. Strikingly, phosphorylation of p-Smad2 and p-Smad3, associated with collagen production, was decreased in TRPM7 deficient HSC-T6 cells. These observations suggested that TGF-β1 elevates TRPM7 expression in HSCs via Smad3-dependant mechanisms, which in turn contributes Smad protein phosphorylation, and subsequently increases fibrous collagen expression. Therefore, TRPM7 may constitute a useful target for the treatment of liver fibrosis. - Highlights: • Upregulation of TRPM7 protein in human fibrotic livers • Upregulation of TRPM7 by TGF-β1 elicited Smad signaling in HSC-T6 cells

  20. Comparison of the Cellient(™) automated cell block system and agar cell block method.

    Kruger, A M; Stevens, M W; Kerley, K J; Carter, C D

    2014-12-01

    To compare the Cellient(TM) automated cell block system with the agar cell block method in terms of quantity and quality of diagnostic material and morphological, histochemical and immunocytochemical features. Cell blocks were prepared from 100 effusion samples using the agar method and Cellient system, and routinely sectioned and stained for haematoxylin and eosin and periodic acid-Schiff with diastase (PASD). A preliminary immunocytochemical study was performed on selected cases (27/100 cases). Sections were evaluated using a three-point grading system to compare a set of morphological parameters. Statistical analysis was performed using Fisher's exact test. Parameters assessing cellularity, presence of single cells and definition of nuclear membrane, nucleoli, chromatin and cytoplasm showed a statistically significant improvement on Cellient cell blocks compared with agar cell blocks (P cell groups, PASD staining or the intensity or clarity of immunocytochemical staining. A discrepant immunocytochemistry (ICC) result was seen in 21% (13/63) of immunostains. The Cellient technique is comparable with the agar method, with statistically significant results achieved for important morphological features. It demonstrates potential as an alternative cell block preparation method which is relevant for the rapid processing of fine needle aspiration samples, malignant effusions and low-cellularity specimens, where optimal cell morphology and architecture are essential. Further investigation is required to optimize immunocytochemical staining using the Cellient method. © 2014 John Wiley & Sons Ltd.

  1. Immunohistochemistry of connexin 43 throughout anterior pituitary gland in a transgenic rat with green fluorescent protein-expressing folliculo-stellate cells.

    Horiguchi, Kotaro; Fujiwara, Ken; Kouki, Tom; Kikuchi, Motoshi; Yashiro, Takashi

    2008-12-01

    Folliculo-stellate (FS) cells in the anterior pituitary gland have been speculated to possess multifunctional properties. Because gap junctions (GJ) have been identified between FS cells, FS cells may be interconnected electrophysiologically by GJ and serve as signal transmission networks to modulate hormone release in the anterior pituitary gland. But whether GJ are localized among FS cells from the pars tuberalis through the pars distalis is unclear. The S100b-GFP transgenic rat has recently been generated, which expresses green fluorescent protein (GFP) specifically in FS cells in the anterior pituitary. This model is expected to be a powerful tool for studies of FS cells. The purpose of the present paper was therefore to examine the localization of GJ on connexin 43 immunohistochemistry throughout the anterior pituitary gland of S100b-GFP rats under confocal laser microscopy. The localization patterns of FS cells was also observed in primary culture of anterior pituitary cells and the question of whether GJ between FS cells are reconstructed in vitro was investigated. In vivo studies showed that GJ were present specifically between FS cells from the pars tuberalis to the pars distalis in the anterior pituitary gland. The appearance of FS cells was distinguished into two types, with localization of GJ differing between types. In vitro, it was observed for the first time that FS cells in primary culture could be categorized into two types. In vivo localization of GJ between FS cells was reconstructed in vitro. These morphological observations are consistent with the hypothesis that FS cells form an electrophysiological network throughout the anterior pituitary for signal transmission.

  2. Dihydroartemisinin alleviates bile duct ligation-induced liver fibrosis and hepatic stellate cell activation by interfering with the PDGF-βR/ERK signaling pathway.

    Chen, Qin; Chen, Lianyun; Kong, Desong; Shao, Jiangjuan; Wu, Li; Zheng, Shizhong

    2016-05-01

    Liver fibrosis represents a frequent event following chronic insult to trigger wound healing responses in the liver. Activation of hepatic stellate cells (HSCs), which is a pivotal event during liver fibrogenesis, is accompanied by enhanced expressions of a series of marker proteins and pro-fibrogenic signaling molecules. Artemisinin, a powerful antimalarial medicine, is extracted from the Chinese herb Artemisia annua L., and can inhibit the proliferation of cancer cells. Dihydroartemisinin (DHA), the major active metabolite of artemisinin, is able to attenuate lung injury and fibrosis. However, the effect of DHA on liver fibrosis remains unclear. The aim of this study was to investigate the effect of DHA on bile duct ligation-induced injury and fibrosis in rats. DHA improved the liver histological architecture and attenuated collagen deposition in the fibrotic rat liver. Experiments in vitro showed that DHA inhibited the proliferation of HSCs and arrested the cell cycle at the S checkpoint by altering several cell-cycle regulatory proteins. Moreover, DHA reduced the protein expressions of a-SMA, α1 (I) collagen and fibronectin, being associated with interference of the platelet-derived growth factor β receptor (PDGF-βR)-mediated ERK pathway. These data collectively revealed that DHA relieved liver fibrosis possibly by targeting HSCs via the PDGF-βR/ERK pathway. DHA may be a therapeutic antifibrotic agent for the treatment of hepatic fibrosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Molecular magnetic resonance imaging of activated hepatic stellate cells with ultrasmall superparamagnetic iron oxide targeting integrin αvβ3 for staging liver fibrosis in rat model

    Zhang C

    2016-03-01

    Full Text Available Caiyuan Zhang,1,* Huanhuan Liu,1,* Yanfen Cui,1,* Xiaoming Li,1 Zhongyang Zhang,1 Yong Zhang,2 Dengbin Wang1 1Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, 2MR Advanced Application and Research Center, GE Healthcare China, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: To evaluate the expression level of integrin αvβ3 on activated hepatic stellate cells (HSCs at different stages of liver fibrosis induced by carbon tetrachloride (CCl4 in rat model and the feasibility to stage liver fibrosis by using molecular magnetic resonance imaging (MRI with arginine-glycine-aspartic acid (RGD peptide modified ultrasmall superparamagnetic iron oxide nanoparticle (USPIO specifically targeting integrin αvβ3.Materials and methods: All experiments received approval from our Institutional Animal Care and Use Committee. Thirty-six rats were randomly divided into three groups of 12 subjects each, and intraperitoneally injected with CCl4 for either 3, 6, or 9 weeks. Controls (n=10 received pure olive oil. The change in T2* relaxation rate (ΔR2* pre- and postintravenous administration of RGD-USPIO or naked USPIO was measured by 3.0T clinical MRI and compared by one-way analysis of variance or the Student’s t-test. The relationship between expression level of integrin αvβ3 and liver fibrotic degree was evaluated by Spearman’s ranked correlation.Results: Activated HSCs were confirmed to be the main cell types expressing integrin αvβ3 during liver fibrogenesis. The protein level of integrin αv and β3 subunit expressed on activated HSCs was upregulated and correlated well with the progression of liver fibrosis (r=0.954, P<0.001; r=0.931, P<0.001, respectively. After injection of RGD-USPIO, there is significant difference in ΔR2* among rats treated with 0, 3, 6, and 9 weeks of CCl4 (P<0.001. The accumulation of iron particles in fibrotic liver specimen is

  4. Carvedilol Improves Inflammatory Response, Oxidative Stress and Fibrosis in the Alcohol-Induced Liver Injury in Rats by Regulating Kuppfer Cells and Hepatic Stellate Cells.

    Raimundo Fernandes de Araújo Júnior

    type III (PCIII, and NF-κB were decreased in the alcohol-CARV 5 mg/kg group relative to the alcohol-only group.CARV can reduce the stress oxidative, inflammatory response and fibrosis in ethanol-induced liver injury in a rat model by downregulating signalling of Kuppfer cells and hepatic stellate cells (HSCs through suppression of inflammatory cytokines.

  5. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) increases necroinflammation and hepatic stellate cell activation but does not exacerbate experimental liver fibrosis in mice

    Lamb, Cheri L.; Cholico, Giovan N. [Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725 (United States); Pu, Xinzhu [Biomolecular Research Center, Boise State University, Boise, ID 83725 (United States); Hagler, Gerald D. [Department of Biological Sciences, Boise State University, Boise, ID 83725 (United States); Cornell, Kenneth A. [Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725 (United States); Biomolecular Research Center, Boise State University, Boise, ID 83725 (United States); Department of Chemistry and Biochemistry, Boise State University, Boise, ID 83725 (United States); Mitchell, Kristen A., E-mail: kristenmitchell@boisestate.edu [Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725 (United States); Department of Biological Sciences, Boise State University, Boise, ID 83725 (United States)

    2016-11-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent environmental contaminant and high-affinity ligand for the aryl hydrocarbon receptor (AhR). Increasing evidence indicates that AhR signaling contributes to wound healing, which involves the coordinated deposition and remodeling of the extracellular matrix. In the liver, wound healing is attributed to the activation of hepatic stellate cells (HSCs), which mediate fibrogenesis through the production of soluble mediators and collagen type I. We recently reported that TCDD treatment increases the activation of human HSCs in vitro. The goal of this study was to determine how TCDD impacts HSC activation in vivo using a mouse model of experimental liver fibrosis. To elicit fibrosis, C57BL6/male mice were treated twice weekly for 8 weeks with 0.5 ml/kg carbon tetrachloride (CCl{sub 4}). TCDD (20 μg/kg) or peanut oil (vehicle) was administered once a week during the last 2 weeks. Results indicate that TCDD increased liver-body-weight ratios, serum alanine aminotransferase activity, and hepatic necroinflammation in CCl{sub 4}-treated mice. Likewise, TCDD treatment increased mRNA expression of HSC activation and fibrogenesis genes, namely α-smooth muscle actin, desmin, delta-like homolog-1, TGF-β1, and collagen type I. However, TCDD treatment did not exacerbate fibrosis, nor did it increase the collagen content of the liver. Instead, TCDD increased hepatic collagenase activity and increased expression of matrix metalloproteinase (MMP)-13 and the matrix regulatory proteins, TIMP-1 and PAI-1. These results support the conclusion that TCDD increases CCl{sub 4}-induced liver damage and exacerbates HSC activation, yet collagen deposition and the development of fibrosis may be limited by TCDD-mediated changes in extracellular matrix remodeling. - Highlights: • TCDD increased liver damage and inflammation in mice treated with CCl{sub 4}. • TCDD treatment enhanced markers of hepatic stellate cell activation and

  6. Regulator of G-protein signaling-5 is a marker of hepatic stellate cells and expression mediates response to liver injury.

    Arya J Bahrami

    Full Text Available Liver fibrosis is mediated by hepatic stellate cells (HSCs, which respond to a variety of cytokine and growth factors to moderate the response to injury and create extracellular matrix at the site of injury. G-protein coupled receptor (GPCR-mediated signaling, via endothelin-1 (ET-1 and angiotensin II (AngII, increases HSC contraction, migration and fibrogenesis. Regulator of G-protein signaling-5 (RGS5, an inhibitor of vasoactive GPCR agonists, functions to control GPCR-mediated contraction and hypertrophy in pericytes and smooth muscle cells (SMCs. Therefore we hypothesized that RGS5 controls GPCR signaling in activated HSCs in the context of liver injury. In this study, we localize RGS5 to the HSCs and demonstrate that Rgs5 expression is regulated during carbon tetrachloride (CCl4-induced acute and chronic liver injury in Rgs5LacZ/LacZ reporter mice. Furthermore, CCl4 treated RGS5-null mice develop increased hepatocyte damage and fibrosis in response to CCl4 and have increased expression of markers of HSC activation. Knockdown of Rgs5 enhances ET-1-mediated signaling in HSCs in vitro. Taken together, we demonstrate that RGS5 is a critical regulator of GPCR signaling in HSCs and regulates HSC activation and fibrogenesis in liver injury.

  7. Expression of E-selectin ligand-1 (CFR/ESL-1) on hepatic stellate cells: implications for leukocyte extravasation and liver metastasis.

    Antoine, Marianne; Tag, Carmen G; Gressner, Axel M; Hellerbrand, Claus; Kiefer, Paul

    2009-02-01

    Leukocytes and tumor cells use E-selectin binding ligands to attach to activated endothelial cells expressing E-selectin during inflammation or metastasis. The cysteine-rich fibroblast growth factor receptor (CFR) represents the main E-selectin ligand (ESL-1) on granulocytes and its expression is exclusively modified by alpha(1,3)-fucosyltransferases IV or VII (FucT4 and FucT7). Hepatic stellate cells (HSC) are pericytes of liver sinusoidal endothelial cells. The activation of HSC and transdifferentiation into a myofibroblastic phenotype is involved in the repair of liver tissue injury, liver regeneration and angiogenesis of liver metastases. In the present study, we demonstrated that HSC expressed CFR together with FucT7 and exhibited a functional E-selectin binding activity on their cell surface. Since HSC appear to be oxygen-sensing cells, the expression of E-selectin binding activity was analyzed in HSC under a hypoxic atmosphere. While the expression of the glycoprotein CFR was unaffected by hypoxia, the cell-associated E-selectin binding activity decreased. However, under the same conditions, mRNA expression of the modifying enzyme FucT7 increased. The loss of E-selectin binding activity, therefore, appears to be neither the result of a reduced expression of the modifying transferase nor the expression of the backbone glycoprotein. After the transient transfection of HSC with CFR cDNA, the E-selectin binding activity (ESL-1) was efficiently released into the supernatant. Therefore, we hypothesize that under hypoxia, ESL-1 is shed from activated HSC. Our findings provide a novel perspective on the function of HSC in liver metastasis and inflammatory liver diseases.

  8. Tumor Necrosis Factor-Like Weak Inducer of Apoptosis Promotes Hepatic Stellate Cells Migration via Canonical NF-κB/MMP9 Pathway.

    Mingcui Xu

    Full Text Available In the liver, the signal and function of tumor necrosis factor-like weak inducer of apoptosis (TWEAK have mainly been assessed in association with liver regeneration. However, the effects of TWEAK on liver fibrosis have not been fully elucidated. To investigate the effects of TWEAK on human hepatic stellate cells (HSCs and to explore the relevant potential mechanisms, human HSCs line-LX-2 were cultured with TWEAK. Cell migration was detected by transwell assay; cell viability was evaluated by Cell Counting Kit-8; the expression of MMP1, MMP2, MMP3, MMP7, MMP8, MMP9, MMP10, MMP11, MMP12, MMP13 gene was identified by quantitative real-time polymerase chain reaction and western blotting; the activity of matrix metalloproteinases (MMPs was tested by enzyme-linked immuno sorbent assay; small interfering RNA transfection was applied for depletion of MMP9 and p65. The result of transwell assay revealed that TWEAK promoted LX-2 migration. Subsequently, our data testified that the expression and activity of MMP9 was induced by TWEAK in LX-2 cells, which enhanced the migration. Furthermore, our findings showed that TWEAK upregulated the phosphorylation of IκBα and p65 protein to increase MMP9 expression in LX-2 cells. Meanwhile, the alpha-smooth muscle actin, vimentin and desmin expression were upregulated following TWEAK treatment. The results in the present study revealed that TWEAK promotes HSCs migration via canonical NF-κB/MMP9 pathway, which possibly provides a molecular basis targeting TWEAK for the therapy of liver fibrosis.

  9. Morin ameliorates chemically induced liver fibrosis in vivo and inhibits stellate cell proliferation in vitro by suppressing Wnt/β-catenin signaling

    MadanKumar, Perumal; NaveenKumar, Perumal; Manikandan, Samidurai [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu (India); Devaraj, Halagowder [Department of Zoology, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu (India); NiranjaliDevaraj, Sivasithamparam, E-mail: niranjali@yahoo.com [Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu (India)

    2014-06-01

    The anti-fibrotic effect of morin was examined in LX-2 cells (culture-activated human hepatic stellate cells) and in diethylnitrosamine induced rat model of liver fibrosis. The in vitro study was designed to determine whether morin affects the survival of cultured LX-2 cells, while the in vivo study was designed to evaluate the antioxidant and anti-fibrotic efficacy of morin on diethylnitrosamine induced liver fibrosis in male albino Wistar rat. The activities of liver function enzymes in serum, liver lipid peroxide levels, activities of serum antioxidant enzymes and liver architecture were monitored to cast light on the antioxidant and hepatoprotective nature of morin. To establish the anti-fibrotic effects of morin, the levels of key Wnt signaling molecules which are strongly associated with the signal transduction pathway of HSC activation were measured. Overall, from the in vitro results, it was observed that morin at 50 μM concentration inhibited the proliferation of cultured LX-2 cells, inhibited Wnt signaling and induced G1 cell cycle arrest. The in vivo results further confirmed that morin by downregulating the expressions of GSK-3β, β-catenin and cyclin D1 ameliorated DEN-induced liver fibrosis. Hence morin could be employed as a promising chemopreventive natural supplement for liver fibrosis. - Highlights: • In vivo and in vitro results revealed the active participation of Wnt signaling. • Morin at 50 μM inhibited LX-2 cell proliferation by suppressing Wnt signaling. • Morin exhibited hepatoprotective effects against DEN induced liver fibrosis. • Morin inhibited HSC activation in vivo by downregulating Wnt/β-catenin signaling.

  10. Fuzheng Huayu Recipe Ameliorates Liver Fibrosis by Restoring Balance between Epithelial-to-Mesenchymal Transition and Mesenchymal-to-Epithelial Transition in Hepatic Stellate Cells

    Qin Pan

    2015-01-01

    Full Text Available Activation of hepatic stellate cells (HSCs depending on epithelial-to-mesenchymal transition (EMT reflects the key event of liver fibrosis. Contrastively, mesenchymal-to-epithelial transition (MET of HSCs facilitates the fibrosis resolution. Here we investigated the effect of Fuzheng Huayu (FZHY recipe, a Chinese herbal decoction made of Radix Salviae Miltiorrhizae, Semen Persicae, Cordyceps sinensis, Pollen Pini, and Gynostemma pentaphyllum, on liver fibrosis concerning the balance of EMT and MET in HSCs. In contrast to the increased TGF-β1/BMP-7 ratio in activated HSCs, FZHY administration induced significant upregulation of BMP-7 and downregulation of TGF-β1 at both transcription and translation levels. Restoration of TGF-β1/BMP-7 ratio inhibited the expression of p38 MAPK and phosphorylated p38 MAPK, resulting in the reversal of epithelial-to-mesenchymal transition (EMT to mesenchymal-to-epithelial transition (MET as characterized by the abolishment of EMT markers (α-SMA and desmin and reoccurrence of MET marker (E-cadherin. In vivo treatment of FZHY recipe also demonstrated the statistical reduction of activated HSCs with EMT phenotype, which attenuated the carbon tetrachloride- (CCl4- induced liver fibrosis in a dose-dependent manner. These findings may highlight a novel antifibrotic role of FZHY recipe on the basis of rebalancing EMT and MET in HSCs.

  11. Standardized Salvia miltiorrhiza Extract Suppresses Hepatic Stellate Cell Activation and Attenuates Steatohepatitis Induced by a Methionine-Choline Deficient Diet in Mice

    Hak Sung Lee

    2014-06-01

    Full Text Available The aim of this study was to examine the effect of standardized extract of Salvia miltiorrhiza (SME on gene and protein expression of non-alcoholic steatohepatitis (NASH-related factors in activated human hepatic stellate cells (HSC, and in mice with steatohepatitis induced by a methionine-choline deficient (MCD diet. Male C57BL/6J mice were placed on an MCD or control diet for 8 weeks and SME (0, 0.1, 0.5 and 1 mg/kg body weight was administered orally every other day for 4 or 6 weeks. HSCs from the LX-2 cell line were treated with transforming growth factor β-1 (TGF-β1 or TGF-β1 plus SME (0.1–10 μg/mL. To investigate the effect of SME on reactive oxygen species (ROS-induced condition, LX-2 cells were treated with hydrogen peroxide (H2O2 or H2O2 plus SME (0.1–100 μg/mL. MCD administration for 12 weeks increased mRNA expression of tumor necrosis factor (TNF-α, TGF-β1, interleukin-1β (IL-1β, C-reactive protein (CRP, α-smooth muscle actin (α-SMA, type I collagen, matrix metalloproteinase-2 (MMP-2 and MMP-9. TGF-β1-induced LX-2 cells exhibited similar gene expression patterns. SME treatment significantly reduced the mRNA and protein expression of NASH-related factors in the mouse model and HSCs. Histopathological liver analysis showed improved non-alcoholic fatty liver disease (NAFLD activity and fibrosis score in SME-treated mice. The in vivo studies showed that SME had a significant effect at low doses. These results suggest that SME might be a potential therapeutic candidate for NAFLD treatment.

  12. Pancreatic stellate cells and CX3CR1: occurrence in normal pancreas, acute and chronic pancreatitis and effect of their activation by a CX3CR1 agonist

    Uchida, Masahiko; Ito, Tetsuhide; Nakamura, Taichi; Hijioka, Masayuki; Igarashi, Hisato; Oono, Takamasa; Kato, Masaki; Nakamura, Kazuhiko; Suzuki, Koichi; Takayanagi, Ryoichi; Jensen, Robert T.

    2014-01-01

    Objectives Numerous studies suggest important roles of the chemokine, fractalkine (CX3CL1) in acute/chronic pancreatitis, however the possible mechanisms of the effects are unclear. Pancreatic stellate cells (PSCs) can play important roles in pancreatitis, secreting inflammatory cytokines/chemokines, as well as proliferation. Therefore, we investigated CX3CL1 receptor (CX3CR1) occurrence in normal pancreas and pancreatitis (acute/chronic) tissues, and the effects of CX3CL1 on activated-PSCs. Methods CX3CR1 expression/localization in normal pancreas and pancreatitis (acute/chronic) tissues were evaluated with immunohistochemical analysis. CX3CR1 expression and effects of CX3CL1 on activated-PSCs were examined with realtime-PCR, BrdU assays and Western Blotting. Results In normal pancreas, acinar cells expressed CX3CR1 within granule-like-formations in the cytoplasm, whereas in acute/chronic pancreatitis, acinar, ductal and activated-PSCs expressed CX3CR1 on cell membranes. With activation of normal PSCs, CX3CR1 is increased. CX3CL1 activated multiple signaling cascades in PSCs. CX3CL1, did not induce inflammatory-genes expression in activated-PSCs, but induced proliferation. Conclusions CX3CR1s are expressed in normal pancreas. Expression is increased in acute/chronic pancreatitis and the CX3CR1s are activated. CX3CL1 induces proliferation of activated-PSCs without increasing release of inflammatory-mediators. These results suggest that CX3CR1 activation of PSCs could be important in their effects in pancreatitis, especially to PSCs proliferation in pancreatitis where CX3CL1 levels are elevated. PMID:24681877

  13. The mechanism of abrupt transition between theta and hyper-excitable spiking activity in medial entorhinal cortex layer II stellate cells.

    Tilman Kispersky

    2010-11-01

    Full Text Available Recent studies have shown that stellate cells (SCs of the medial entorhinal cortex become hyper-excitable in animal models of temporal lobe epilepsy. These studies have also demonstrated the existence of recurrent connections among SCs, reduced levels of recurrent inhibition in epileptic networks as compared to control ones, and comparable levels of recurrent excitation among SCs in both network types. In this work, we investigate the biophysical and dynamic mechanism of generation of the fast time scale corresponding to hyper-excitable firing and the transition between theta and fast firing frequency activity in SCs. We show that recurrently connected minimal networks of SCs exhibit abrupt, threshold-like transition between theta and hyper-excitable firing frequencies as the result of small changes in the maximal synaptic (AMPAergic conductance. The threshold required for this transition is modulated by synaptic inhibition. Similar abrupt transition between firing frequency regimes can be observed in single, self-coupled SCs, which represent a network of recurrently coupled neurons synchronized in phase, but not in synaptically isolated SCs as the result of changes in the levels of the tonic drive. Using dynamical systems tools (phase-space analysis, we explain the dynamic mechanism underlying the genesis of the fast time scale and the abrupt transition between firing frequency regimes, their dependence on the intrinsic SC's currents and synaptic excitation. This abrupt transition is mechanistically different from others observed in similar networks with different cell types. Most notably, there is no bistability involved. 'In vitro' experiments using single SCs self-coupled with dynamic clamp show the abrupt transition between firing frequency regimes, and demonstrate that our theoretical predictions are not an artifact of the model. In addition, these experiments show that high-frequency firing is burst-like with a duration modulated by an M-current.

  14. Plumbagin Inhibits Leptin-Induced Proliferation of Hepatic Stellate ...

    Purpose: To investigate the protective effects of plumbagin against liver fibrosis and explore the influence of plumbagin on the proliferation of hepatic stellate cells (HSCs). Methods: HSC-LX2 cells were divided into blank/control group, 100 ng/ml leptin group, 100 ng/ml leptin + 2 μmol/L plumbagin group, 100 ng/ml leptin + ...

  15. Stellate Cell Activation and Imbalanced Expression of TGF-β1/TGF-β3 in Acute Autoimmune Liver Lesions Induced by ConA in Mice

    Liyun Wang

    2017-01-01

    Full Text Available Objective. To study the pathogenic feature of liver injury, activation of hepatic stellate cells, and dynamic expression of TGF-β1/TGF-β3 to reveal their role in liver injury induced by ConA. Methods. Mice were randomly divided into control group and ConA treatment group. ConA (20 mg/kg was injected through vena caudalis in ConA treatment group; the controls received the same volume of saline injection. After injection for 2 h, 8 h, 24 h, and 48 h, animals were terminated. Blood, liver, and spleen were harvested. Liver function and histopathology were studied. α-SMA, vimentin, TGF-β1, and TGF-β3 were detected. Results. After ConA injection, liver damage started to increase. Expression of α-SMA, vimentin, TGF-β1, and TGF-β3 was significantly enhanced; all above indicators reached peak at 8 h; but from 24 h after ConA injection, TGF-β3 expression began to decline, while the TGF-β1/TGF-β3 ratio at 48 h was significantly lower than control. Conclusion. (1 Autoimmune liver injury induced by ConA showed time-based features, in which the most serious liver lesions happened at 8 h after ConA injection. (2 Early activation of HSC and imbalance expression of TGF-β1 and TGF-β3 existed in ConA-induced acute autoimmune liver injury, which may be associated with liver dysfunction and the mechanisms of progression to fibrosis.

  16. The effect of down-regulation of Smad3 by RNAi on hepatic stellate cells and a carbon tetrachloride-induced rat model of hepatic fibrosis

    Z.R. Wang

    2011-02-01

    Full Text Available Searching for effective Smad3 gene-based gene therapies for hepatic fibrosis, we constructed siRNA expression plasmids targeting the rat Smad3 gene and then delivered these plasmids into hepatic stellate cells (HSCs. The effect of siRNAs on the mRNA levels of Smad2, Smad3, Smad4, and collagens I-α1, III-α1 and IV-α1 (Colα1, Col3α1, Col4α1, respectively was determined by RT-PCR. Eighty adult male Sprague-Dawley rats were randomly divided into three groups. Twice a week for 8 weeks, the untreated hepatic fibrosis model (N = 30 and the treated group (N = 20 were injected subcutaneously with 40% (v/v carbon tetrachloride (CCl4-olive oil (3 mL/kg, and the normal control group (N = 30 was injected with olive oil (3 mL/kg. In the 4th week, the treated rats were injected subcutaneously with liposome-encapsulated plasmids (150 µg/kg into the right liver lobe under general anesthesia once every 2 weeks, and the untreated rats were injected with the same volume of buffer. At the end of the 6th and 8th weeks, liver tissue and sera were collected. Pathological changes were assessed by a semi-quantitative scoring system (SSS, and a radioimmunoassay was used to establish a serum liver fibrosis index (type III procollagen, type IV collagen, laminin, and hyaluronic acid. The mRNA expression levels of the above cited genes were reduced in the HSCs transfected with the siRNA expression plasmids. Moreover, in the treated group, fibrosis evaluated by the SSS was significantly reduced (P < 0.05 and the serum indices were greatly improved (P < 0.01. These results suggest that Smad3 siRNA expression plasmids have an anti-fibrotic effect.

  17. Vitamin A-coupled liposome system targeting free cholesterol accumulation in hepatic stellate cells offers a beneficial therapeutic strategy for liver fibrosis.

    Furuhashi, Hirotaka; Tomita, Kengo; Teratani, Toshiaki; Shimizu, Motonori; Nishikawa, Makoto; Higashiyama, Masaaki; Takajo, Takeshi; Shirakabe, Kazuhiko; Maruta, Koji; Okada, Yoshikiyo; Kurihara, Chie; Watanabe, Chikako; Komoto, Shunsuke; Aosasa, Suefumi; Nagao, Shigeaki; Yamamoto, Junji; Miura, Soichiro; Hokari, Ryota

    2018-04-01

    Liver fibrosis is a life-threatening disorder for which no approved therapy is available. Recently, we reported that mouse hepatic stellate cell (HSC) activation increased free cholesterol (FC) accumulation, partly by enhancing signaling through sterol regulatory element-binding protein 2 (SREBP2) and microRNA-33a (miR-33a), which resulted in HSC sensitization to transforming growth factor-β (TGFβ)-induced activation in a "vicious cycle" of liver fibrosis. Human HSCs were isolated from surgical liver specimens from control patients and patients with liver fibrosis. C57BL/6 mice were treated with carbon tetrachloride for 4 weeks and concurrently given SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes. In human activated HSCs obtained from patients with liver fibrosis, FC accumulation was enhanced independently of serum cholesterol levels through increased signaling by both SREBP2 and miR-33a. This increased FC accumulation enhanced Toll-like receptor 4 (TLR4) protein levels and lowered the TGFβ-pseudoreceptor Bambi (bone morphogenetic protein and activin membrane-bound inhibitor) mRNA levels in HSCs. Notably, in a mouse liver fibrosis model, reduction of FC accumulation, specifically in activated HSCs by suppression of SREBP2 or miR-33a expression using SREBP2-siRNA- or anti-miR-33a-bearing vitamin A-coupled liposomes, downregulated TLR4 signaling, increased Bambi expression, and consequently ameliorated liver fibrosis. Our results suggest that FC accumulation in HSCs, as an intracellular mediator promoting HSC activation, contributes to a vicious cycle of HSC activation in human and mouse liver fibrosis independent of serum cholesterol levels. Targeting FC accumulation-related molecules in HSCs through a vitamin A-coupled liposomal system represents a favorable therapeutic strategy for liver fibrosis. © 2017 The Japan Society of Hepatology.

  18. Deficiency of NOX1 or NOX4 Prevents Liver Inflammation and Fibrosis in Mice through Inhibition of Hepatic Stellate Cell Activation.

    Tian Lan

    Full Text Available Reactive oxygen species (ROS produced by nicotinamide adenine dinucleotide phosphate oxidase (NOX play a key role in liver injury and fibrosis. Previous studies demonstrated that GKT137831, a dual NOX1/4 inhibitor, attenuated liver fibrosis in mice as well as pro-fibrotic genes in hepatic stellate cells (HSCs as well as hepatocyte apoptosis. The effect of NOX1 and NOX4 deficiency in liver fibrosis is unclear, and has never been directly compared. HSCs are the primary myofibroblasts in the pathogenesis of liver fibrosis. Therefore, we aimed to determine the role of NOX1 and NOX4 in liver fibrosis, and investigated whether NOX1 and NOX4 signaling mediates liver fibrosis by regulating HSC activation. Mice were treated with carbon tetrachloride (CCl4 to induce liver fibrosis. Deficiency of either NOX1 or NOX4 attenuates liver injury, inflammation, and fibrosis after CCl4 compared to wild-type mice. NOX1 or NOX4 deficiency reduced lipid peroxidation and ROS production in mice with liver fibrosis. NOX1 and NOX4 deficiency are approximately equally effective in preventing liver injury in the mice. The NOX1/4 dual inhibitor GKT137831 suppressed ROS production as well as inflammatory and proliferative genes induced by lipopolysaccharide (LPS, platelet-derived growth factor (PDGF, or sonic hedgehog (Shh in primary mouse HSCs. Furthermore, the mRNAs of proliferative and pro-fibrotic genes were downregulated in NOX1 and NOX4 knock-out activated HSCs (cultured on plastic for 5 days. Finally, NOX1 and NOX4 protein levels were increased in human livers with cirrhosis compared with normal controls. Thus, NOX1 and NOX4 signaling mediates the pathogenesis of liver fibrosis, including the direct activation of HSC.

  19. RNA Sequencing and Bioinformatics Analysis Implicate the Regulatory Role of a Long Noncoding RNA-mRNA Network in Hepatic Stellate Cell Activation.

    Guo, Can-Jie; Xiao, Xiao; Sheng, Li; Chen, Lili; Zhong, Wei; Li, Hai; Hua, Jing; Ma, Xiong

    2017-01-01

    To analyze the long noncoding (lncRNA)-mRNA expression network and potential roles in rat hepatic stellate cells (HSCs) during activation. LncRNA expression was analyzed in quiescent and culture-activated HSCs by RNA sequencing, and differentially expressed lncRNAs verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) were subjected to bioinformatics analysis. In vivo analyses of differential lncRNA-mRNA expression were performed on a rat model of liver fibrosis. We identified upregulation of 12 lncRNAs and 155 mRNAs and downregulation of 12 lncRNAs and 374 mRNAs in activated HSCs. Additionally, we identified the differential expression of upregulated lncRNAs (NONRATT012636.2, NONRATT016788.2, and NONRATT021402.2) and downregulated lncRNAs (NONRATT007863.2, NONRATT019720.2, and NONRATT024061.2) in activated HSCs relative to levels observed in quiescent HSCs, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed that changes in lncRNAs associated with HSC activation revealed 11 significantly enriched pathways according to their predicted targets. Moreover, based on the predicted co-expression network, the relative dynamic levels of NONRATT013819.2 and lysyl oxidase (Lox) were compared during HSC activation both in vitro and in vivo. Our results confirmed the upregulation of lncRNA NONRATT013819.2 and Lox mRNA associated with the extracellular matrix (ECM)-related signaling pathway in HSCs and fibrotic livers. Our results detailing a dysregulated lncRNA-mRNA network might provide new treatment strategies for hepatic fibrosis based on findings indicating potentially critical roles for NONRATT013819.2 and Lox in ECM remodeling during HSC activation. © 2017 The Author(s). Published by S. Karger AG, Basel.

  20. Cellient™ automated cell block versus traditional cell block preparation: a comparison of morphologic features and immunohistochemical staining.

    Wagner, David G; Russell, Donna K; Benson, Jenna M; Schneider, Ashley E; Hoda, Rana S; Bonfiglio, Thomas A

    2011-10-01

    Traditional cell block (TCB) sections serve as an important diagnostic adjunct to cytologic smears but are also used today as a reliable preparation for immunohistochemical (IHC) studies. There are many ways to prepare a cell block and the methods continue to be revised. In this study, we compare the TCB with the Cellient™ automated cell block system. Thirty-five cell blocks were obtained from 16 benign and 19 malignant nongynecologic cytology specimens at a large university teaching hospital and prepared according to TCB and Cellient protocols. Cell block sections from both methods were compared for possible differences in various morphologic features and immunohistochemical staining patterns. In the 16 benign cases, no significant morphologic differences were found between the TCB and Cellient cell block sections. For the 19 malignant cases, some noticeable differences in the nuclear chromatin and cellularity were identified, although statistical significance was not attained. Immunohistochemical or special stains were performed on 89% of the malignant cases (17/19). Inadequate cellularity precluded full evaluation in 23% of Cellient cell block IHC preparations (4/17). Of the malignant cases with adequate cellularity (13/17), the immunohistochemical staining patterns from the different methods were identical in 53% of cases. The traditional and Cellient cell block sections showed similar morphologic and immunohistochemical staining patterns. The only significant difference between the two methods concerned the lower overall cell block cellularity identified during immunohistochemical staining in the Cellient cell block sections. Copyright © 2010 Wiley-Liss, Inc.

  1. MicroRNA-130a and -130b enhance activation of hepatic stellate cells by suppressing PPARγ expression: A rat fibrosis model study

    Lu, Le; Wang, Jinlong; Lu, Hongwei [Department of General Surgery, The Second Affiliated Hospital of Xi' an Jiaotong University, No.157, West 5th Road, Xi' an, Shaanxi 710004 (China); Zhang, Guoyu [West Hospital Ward 1, Shaanxi Provincial People' s Hospital, No.256, Youyi Road(west), Xi' an, Shaanxi 710068 (China); Liu, Yang; Wang, Jiazhong; Zhang, Yafei; Shang, Hao; Ji, Hong; Chen, Xi; Duan, Yanxia [Department of General Surgery, The Second Affiliated Hospital of Xi' an Jiaotong University, No.157, West 5th Road, Xi' an, Shaanxi 710004 (China); Li, Yiming, E-mail: yiminngli@163.com [Department of General Surgery, The Second Affiliated Hospital of Xi' an Jiaotong University, No.157, West 5th Road, Xi' an, Shaanxi 710004 (China)

    2015-09-25

    Hepatic stellate cells (HSCs) are the primary sources of extracellular matrix (ECM) in normal and fibrotic liver. Peroxisome proliferator-activated receptor gamma (PPARγ) maintains HSCs in a quiescent state, and its downregulation induces HSC activation. MicroRNAs (miRNAs) can induce PPARγ mRNA degradation, but the mechanism by which miRNAs regulate PPARγ in rat HSCs is unclear. This study aimed to investigate some miRNAs which putatively bind to the 3′-untranslated region (3′-UTR) of PPARγ mRNA, and increase expression of ECM genes in rat HSCs. In carbon tetrachloride injection (CCl{sub 4}) and common bile duct ligation (CBDL) liver fibrosis models, miRNAs miR-130a, miR-130b, miR-301a, miR-27b and miR-340 levels were found to be increased and PPARγ expression decreased. Overexpression of miR-130a and miR-130b enhanced cell proliferation by involving Runx3. MiR-130a and miR-130b decreased PPARγ expression by targeting the 3′-UTR of PPARγ mRNA in rat HSC-T6 cells. Transforming growth factor-β1 (TGF-β1) may mediate miR-130a and miR-130b overexpression, PPARγ downregulation, and ECM genes overexpression in cell culture. These findings suggest that miR-130a and miR-130b are involved in downregulation of PPARγ in liver fibrosis. - Highlights: • MiR-130a and miR-130b are increased and PPARγ is decreased in liver fibrosis models. • MiR-130a and miR-130b decreased PPARγ by targeting the 3′-UTR of PPARγ mRNA. • MiR-130a and miR-130b enhanced HSC cell proliferation by involving Runx3. • TGF-β1 may mediate miR-130a and miR-130b overexpression.

  2. MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

    Zhang, Yifei; Ghazwani, Mohammed; Li, Jiang [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Sun, Ming; Stolz, Donna B. [Department of Cell Biology and Physiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261 (United States); He, Fengtian [Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038 (China); Fan, Jie [Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Xie, Wen [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Li, Song, E-mail: sol4@pitt.edu [Center for Pharmacogenetics, Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

    2014-04-18

    Highlights: • Enhanced HSP47 and LOX expression is associated with decreased miR-29b level in liver fibrosis. • miR-29b down-regulates HSP47 and LOX expression. • The suppression of HSP47 and LOX by miR-29b is mediated by putative sites at their 3′-UTRs. • miR-29b inhibits extracellular LOX activity and collagen maturation. - Abstract: Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a role in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl{sub 4}-treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation.

  3. Inhibition of the SphK1/S1P signaling pathway by melatonin in mice with liver fibrosis and human hepatic stellate cells.

    González-Fernández, Bárbara; Sánchez, Diana I; Crespo, Irene; San-Miguel, Beatriz; Álvarez, Marcelino; Tuñón, María J; González-Gallego, Javier

    2017-03-01

    The sphingosine kinase 1/sphingosine 1-phosphate (SphK1/S1P) system is involved in different pathological processes, including fibrogenesis. Melatonin abrogates activation of hepatic stellate cells (HSCs) and attenuates different profibrogenic pathways in animal models of fibrosis, but it is unknown if protection associates with its inhibitory effect on the SphK1/S1P axis. Mice in treatment groups received carbon tetrachloride (CCl 4 ) 5 μL g -1 body wt i.p. twice a week for 4 or 6 weeks. Melatonin was given at 5 or 10 mg kg -1  day -1 i.p, beginning 2 weeks after the start of CCl 4 administration. At both 4 and 6 weeks following CCl 4 treatment, liver mRNA levels, protein concentration and immunohistochemical labelling for SphK1 increased significantly. S1P production, and expression of S1P receptor (S1PR)1, S1PR3 and acid sphingomyelinase (ASMase) were significantly elevated. However, there was a decreased expression of S1PR2 and S1P lyase (S1PL). Melatonin attenuated liver fibrosis, as shown by a significant inhibition of the expression of α-smooth muscle actin (α-SMA), transforming growth factor (TGF)-β and collagen (Col) Ι. Furthermore, melatonin inhibited S1P production, lowered expression of SphK1, S1PR1, SP1R3, and ASMase, and increased expression of S1PL. Melatonin induced a reversal of activated human HSCs cell line LX2, as evidenced by a reduction in α-SMA, TGF-β, and Col I expression. Melatonin-treated cells also exhibited an inhibition of the SphK1/S1P axis. Antifibrogenic effect of SphK1 inhibition was confirmed by treatment of LX2 cells with PF543. Abrogation of the lipid signaling pathway by the indole reveals novel molecular pathways that may account for the protective effect of melatonin in liver fibrogenesis. © 2016 BioFactors, 43(2):272-282, 2017. © 2016 International Union of Biochemistry and Molecular Biology.

  4. MiR-29b inhibits collagen maturation in hepatic stellate cells through down-regulating the expression of HSP47 and lysyl oxidase

    Zhang, Yifei; Ghazwani, Mohammed; Li, Jiang; Sun, Ming; Stolz, Donna B.; He, Fengtian; Fan, Jie; Xie, Wen; Li, Song

    2014-01-01

    Highlights: • Enhanced HSP47 and LOX expression is associated with decreased miR-29b level in liver fibrosis. • miR-29b down-regulates HSP47 and LOX expression. • The suppression of HSP47 and LOX by miR-29b is mediated by putative sites at their 3′-UTRs. • miR-29b inhibits extracellular LOX activity and collagen maturation. - Abstract: Altered expression of miR-29b is implicated in the pathogenesis and progression of liver fibrosis. We and others previously demonstrated that miR-29b down-regulates the expression of several extracellular-matrix (ECM) genes including Col 1A1, Col 3A1 and Elastin via directly targeting their 3′-UTRs. However, whether or not miR-29b plays a role in the post-translational regulation of ECM biosynthesis has not been reported. Heat shock protein 47 (HSP47) and lysyl oxidase (LOX) are known to be essential for ECM maturation. In this study we have demonstrated that expression of HSP47 and LOX was significantly up-regulated in culture-activated primary rat hepatic stellate cells (HSCs), TGF-β stimulated LX-2 cells and liver tissue of CCl 4 -treated mice, which was accompanied by a decrease of miR-29b level. In addition, over-expression of miR-29b in LX-2 cells resulted in significant inhibition on HSP47 and LOX expression. Mechanistically, miR-29b inhibited the expression of a reporter gene that contains the respective full-length 3′-UTR from HSP47 and LOX gene, and this inhibitory effect was abolished by the deletion of a putative miR-29b targeting sequence from the 3′-UTRs. Transfection of LX-2 cells with miR-29b led to abnormal collagen structure as shown by electron-microscopy, presumably through down-regulation of the expression of molecules involved in ECM maturation including HSP47 and LOX. These results demonstrated that miR-29b is involved in regulating the post-translational processing of ECM and fibril formation

  5. Hepatic Stellate Cell Coculture Enables Sorafenib Resistance in Huh7 Cells through HGF/c-Met/Akt and Jak2/Stat3 Pathways

    Weibo Chen

    2014-01-01

    Full Text Available Purpose. Tumor microenvironment confers drug resistance to kinase inhibitors by increasing RKT ligand levels that result in the activation of cell-survival signaling including PI3K and MAPK signals. We assessed whether HSC-LX2 coculture conferred sorafenib resistance in Huh7 and revealed the mechanism underlying the drug resistance. Experimental Design. The effect of LX2 on sorafenib resistance was determined by coculture system with Huh7 cells. The rescue function of LX2 supernatants was assessed by MTT assay and fluorescence microscopy. The underlying mechanism was tested by administration of pathway inhibitors and manifested by Western blotting. Results. LX2 coculture significantly induced sorafenib resistance in Huh7 by activating p-Akt that led to reactivation of p-ERK. LX2 secreted HGF into the culture medium that triggered drug resistance, and exogenous HGF could also induce sorafenib resistance. The inhibition of p-Akt blocked sorafenib resistance caused by LX2 coculture. Increased phosphorylation of Jak2 and Stat3 was also detected in LX2 cocultured Huh7 cells. The Jak inhibitor tofacitinib reversed sorafenib resistance by blocking Jak2 and Stat3 activation. The combined administration of sorafenib and p-Stat3 inhibitor S3I-201 augmented induced apoptosis even in the presence of sorafenib resistance. Conclusions. HSC-LX2 coculture induced sorafenib resistance in Huh7 through multiple pathways: HGF/c-Met/Akt pathway and Jak2/Stat3 pathway. A combined administration of sorafenib and S3I-201 was able to augment sorafenib-induced apoptosis even in the presence of LX2 coculture.

  6. Calcium channel blockers ameliorate iron overload-associated hepatic fibrosis by altering iron transport and stellate cell apoptosis

    Zhang, Ying [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Department of Pathology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease, Shijiazhuang 050200, Hebei (China); Zhao, Xin [Department of Hepatobiliary Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang 050051, Hebei (China); Chang, Yanzhong [Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University, Shijiazhuang 050024, Hebei (China); Zhang, Yuanyuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Xi [Department of Pharmacy, The Forth Hospital of Hebei Medical University, Shijiazhuang 050011, Hebei (China); Zhang, Xuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Liu, Zhenyi; Guo, Hui [Department of Medicinal Chemistry, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Wang, Na [Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Gao, Yonggang [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Zhang, Jianping, E-mail: zhangjianping14@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Li, E-mail: chuli0614@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Shijiazhuang 050200, Hebei (China)

    2016-06-15

    Liver fibrosis is the principal cause of morbidity and mortality in patients with iron overload. Calcium channel blockers (CCBs) can antagonize divalent cation entry into renal and myocardial cells and inhibit fibrogenic gene expression. We investigated the potential of CCBs to resolve iron overload-associated hepatic fibrosis. Kunming mice were assigned to nine groups (n = 8 per group): control, iron overload, deferoxamine, high and low dose verapamil, high and low dose nimodipine, and high and low dose diltiazem. Iron deposition and hepatic fibrosis were measured in mouse livers. Expression levels of molecules associated with transmembrane iron transport were determined by molecular biology approaches. In vitro HSC-T6 cells were randomized into nine groups (the same groups as the mice). Changes in proliferation, apoptosis, and metalloproteinase expression in cells were detected to assess the anti-fibrotic effects of CCBs during iron overload conditions. We found that CCBs reduced hepatic iron content, intracellular iron deposition, the number of hepatic fibrotic areas, collagen expression levels, and hydroxyproline content. CCBs rescued abnormal expression of α1C protein in L-type voltage-dependent calcium channel (LVDCC) and down-regulated divalent metal transporter-1 (DMT-1) expression in mouse livers. In iron-overloaded HSC-T6 cells, CCBs reduced iron deposition, inhibited proliferation, induced apoptosis, and elevated expression of matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1). CCBs are potential therapeutic agents that can be used to address hepatic fibrosis during iron overload. They resolve hepatic fibrosis probably correlated with regulating transmembrane iron transport and inhibiting HSC growth. - Highlights: • Calcium channel blockers (CCBs) reduced hepatic iron content. • CCBs decreased hepatic fibrotic areas and collagen expression levels. • CCBs resolve fibrosis by regulating iron transport and

  7. Assessing activation of hepatic stellate cells by 99mTc-3PRGD2 scintigraphy targeting integrin αvβ3: a feasibility study

    Zhang, Xin; Xin, Jun; Shi, Yu; Xu, Weina; Yu, Shupeng; Yang, Zhiguang; Liu, Changping; Cao, Li; Guo, Qiyong

    2015-01-01

    Objective: Hepatic stellate cell (HSC) activation, which is accompanied by increased expression of integrin αvβ3, is an important factor in liver fibrogenesis. Molecular imaging targeting the integrin αvβ3 could provide a non-invasive method for evaluating the expression and the function of the integrin αvβ3 on the activated HSCs (aHSCs) in the injured liver, and then provide important prognostic information. 99m Tc-3PRGD2 is such a radiotracer specific for integrin αvβ3. In this study, we aimed to compare the differences in liver uptake and retention of the 99m Tc-3PRGD2 between normal liver and injured liver to evaluate the feasibility of 99m Tc-3PRGD2 scintigraphy for this purpose. Methods: We used planar scintigraphy to assess changes in integrin αvβ3 binding of intravenously-administered 99m Tc-3PRGD2 in the livers of rats with thioacetamide (TAA)-induced liver fibrosis compared with the controls. We co-injected cold c(RGDyK) with 99m Tc-3PRGD2 to assess the specific binding of the radiotracer. We performed Sirius red staining to assess liver fibrosis, immunofluorescent colocalization to identify the location of integrin αvβ3 expressed in the fibrotic liver, and we measured protein and messenger RNA expression of integrin αvβ3 and alpha smooth muscle actin (α-SMA) in the control and fibrotic livers. Results: The fibrotic livers showed enhanced 99m Tc-3PRGD2 uptake and retention. The radiotracer was demonstrated to bind specifically with the integrin αvβ3 mainly expressed on the aHSCs. The liver-to-heart ratio at 30 min post-injection was higher in the fibrotic livers than in the control livers (TAA, 1.98 ± 0.08 vs. control, 1.50 ± 0.12, p < 0.01). The liver t 1/2 was longer than in the controls (TAA, 27.07 ± 10.69 min vs. control, 12.67 ± 4.10 min, p < 0.01). The difference of heart t 1/2 between the two groups was not statistically significant (TAA, 3.13 ± 0.63 min vs. control, 3.41 ± 0.77 min, p = 0.94). Conclusions: 99m Tc-3PRGD2

  8. [Effects of exogenous TGF-β3 on the expression of endogenous TGF-β3 in hepatic stellate cell-T6 (HSC-T6)].

    Li, Ying; Deng, Liang; Qian, Wei; Zhou, Jian-ning; Xu, Ke-shu

    2011-11-01

    To investigate the effects of exogenous TGF-β3 on the expression of endogenous TGF-b3 in hepatic stellate cell (HSC). HSCs were cultured and divided into two groups: TGF-β3 group and blank control group, the cells of TGF-β3 group were exposed to TGF-b3 (10 ng/ml), whereas the blank control group was not treated. The cells were incubated in the presence of exogenous TGF-β3 and then (1) were harvested at 0h, 1h, 2h, 4h, 12h, 24h, and real time PCR was performed to detect the mRNA expression of endogenous TGF-β3. (2) The cells were collected at 0h, 1h, 6h, 12h, and western-blot was used to detect the protein synthesis of endogenous TGF-β3 in HSC; (3) The cell culture supernatant was harvested at 0h, 1h, 2h, 4h, 8h, 14h, 24h, and ELISA was performed to measure the total protein of extracellular TGF-β3; HSCs were treated with TGF-β3 (10 ng/ml) for 2h. The cells were then incubated in serum-free medium and the cell culture supernatant was harvested at 2.25h, 2.5h, 3h, 4h, 6h, 10h and 14h. ELISA was used to detect the extracellular secret ion of endogenous TGF-β3 by HSCs. (1) Exogenous TGF-β3 treatment induced a marked increase in TGF-β3 mRNA expression. By 2h of exogenous TGF-β3 treatment, maximal TGF-β3 mRNA expression levels (2.796 ± 0.518) of 2.74 fold above control values (1.022 ± 0.038) was reached (P endogenous TGF-β3 was found between two groups. (P > 0.05); (3) The total expression level of TGF-β3 reached a peak [(18.931 ± 2.904) ng/ml] at 4h after TGF-β3 treatment (1.89-fold higher than basic TGF-β3 (10 ng/ml). After that, it slowly declined. The expression peak [(0.835 ± 0.027) ng/ml] induction of extracellular secreted TGF-β3 was at 3h (32.12-fold higher than control [(0.026 ± 0.022) ng/ml], (P Exogenous TGF-β3 could increase the expression of endogenous TGF-β3 mRNA and extracellular secreted TGF-β3 protein obviously.

  9. TGF-beta1 modulates matrix metalloproteinase-13 expression in hepatic stellate cells by complex mechanisms involving p38MAPK, PI3-kinase, AKT, and p70S6k.

    Lechuga, Carmen G; Hernández-Nazara, Zamira H; Domínguez Rosales, José-Alfredo; Morris, Elena R; Rincón, Ana Rosa; Rivas-Estilla, Ana María; Esteban-Gamboa, Andrés; Rojkind, Marcos

    2004-11-01

    Transforming growth factor-beta1 (TGF-beta1), the main cytokine involved in liver fibrogenesis, induces expression of the type I collagen genes in hepatic stellate cells by a transcriptional mechanism, which is hydrogen peroxide and de novo protein synthesis dependent. Our recent studies have revealed that expression of type I collagen and matrix metalloproteinase-13 (MMP-13) mRNAs in hepatic stellate cells is reciprocally modulated. Because TGF-beta1 induces a transient elevation of alpha1(I) collagen mRNA, we investigated whether this cytokine was able to induce the expression of MMP-13 mRNA during the downfall of the alpha1(I) collagen mRNA. In the present study, we report that TGF-beta1 induces a rapid decline in steady-state levels of MMP-13 mRNA at the time that it induces the expression of alpha1(I) collagen mRNA. This change in MMP-13 mRNA expression occurs within the first 6 h postcytokine administration and is accompanied by a twofold increase in gene transcription and a fivefold decrease in mRNA half-life. This is followed by increased expression of MMP-13 mRNA, which reaches maximal values by 48 h. Our results also show that this TGF-beta1-mediated effect is de novo protein synthesis-dependent and requires the activity of p38MAPK, phosphatidylinositol 3-kinase, AKT, and p70(S6k). Altogether, our data suggest that regulation of MMP-13 by TGF-beta1 is a complex process involving transcriptional and posttranscriptional mechanisms.

  10. Block Textured a-Si:H Solar Cell

    Seung Jae Moon

    2014-01-01

    Full Text Available A series of etching experiments on light trapping structure have been carried out by glass etching. The block structure provides long light traveling path and a constant distance between the cathode and anode electrodes regardless of the block height, which results in higher efficiency of the block textured solar cell. In terms of etching profile of the glass substrate, the addition of NH4F resulted in the smooth and clean etching profile, and the steep slope of the block was obtained by optimizing the composition of etching solution. For a higher HF concentration, a more graded slope was obtained and the addition of HNO3 and NH4F provided steep slope and clean etching profile. The effects of the block textured glass were verified by a comparison of the solar cell efficiency. For the textured solar cell, the surface was much rougher than that of the plain glass, which also contributes to the improvement of the efficiency. We accomplished block shaped light trapping structure for the first time by wet etching of the glass substrate, which enables the high efficiency thin film solar cell with the aid of the good step coverage deposition.

  11. Caffeine Inhibits the Activation of Hepatic Stellate Cells Induced by Acetaldehyde via Adenosine A2A Receptor Mediated by the cAMP/PKA/SRC/ERK1/2/P38 MAPK Signal Pathway

    Yang, Wanzhi; Wang, Qi; Zhao, Han; Yang, Feng; Lv, Xiongwen; Li, Jun

    2014-01-01

    Hepatic stellate cell (HSC) activation is an essential event during alcoholic liver fibrosis. Evidence suggests that adenosine aggravates liver fibrosis via the adenosine A2A receptor (A2AR). Caffeine, which is being widely consumed during daily life, inhibits the action of adenosine. In this study, we attempted to validate the hypothesis that caffeine influences acetaldehyde-induced HSC activation by acting on A2AR. Acetaldehyde at 50, 100, 200, and 400 μM significantly increased HSC-T6 cells proliferation, and cell proliferation reached a maximum at 48 h after exposure to 200 μM acetaldehyde. Caffeine and the A2AR antagonist ZM241385 decreased the cell viability and inhibited the expression of procollagen type I and type III in acetaldehyde-induced HSC-T6 cells. In addition, the inhibitory effect of caffeine on the expression of procollagen type I was regulated by A2AR-mediated signal pathway involving cAMP, PKA, SRC, and ERK1/2. Interestingly, caffeine’s inhibitory effect on the expression of procollagen type III may depend upon the A2AR-mediated P38 MAPK-dependent pathway. Conclusions: Caffeine significantly inhibited acetaldehyde-induced HSC-T6 cells activation by distinct A2AR mediated signal pathway via inhibition of cAMP-PKA-SRC-ERK1/2 for procollagen type I and via P38 MAPK for procollagen type III. PMID:24682220

  12. The inhibition of activated hepatic stellate cells proliferation by arctigenin through G0/G1 phase cell cycle arrest: persistent p27(Kip1) induction by interfering with PI3K/Akt/FOXO3a signaling pathway.

    Li, Ao; Wang, Jun; Wu, Mingjun; Zhang, Xiaoxun; Zhang, Hongzhi

    2015-01-15

    Proliferation of hepatic stellate cells (HSCs) is vital for the development of fibrosis during liver injury. In this study, we describe that arctigenin (ATG), a major bioactive component of Fructus Arctii, exhibited selective cytotoxic activity via inhibiting platelet-derived growth factor-BB (PDGF-BB)-activated HSCs proliferation and arrested cell cycle at G0/G1 phase, which could not be observed in normal human hepatocytes in vitro. The cyclin-dependent kinase (CDK) 4/6 activities could be strongly inhibited by ATG through down-regulation of cyclin D1 and CDK4/6 expression in early G1 phase arrest. In the ATG-treated HSCs, the expression level of p27(Kip1) and the formation of CDK2-p27(Kip1) complex were also increased. p27(Kip1) silencing significantly attenuated the effect of ATG, including cell cycle arrest and suppression of proliferation in activated HSCs. We also found that ATG suppressed PDGF-BB-induced phosphorylation of Akt and its downstream transcription factor Forkhead box O 3a (FOXO3a), decreased binding of FOXO3a to 14-3-3 protein, and stimulated nuclear translocation of FOXO3a in activated HSCs. Furthermore, knockdown of FOXO3a expression by FOXO3a siRNA attenuated ATG-induced up-regulation of p27(Kip1) in activated HSCs. All the above findings suggested that ATG could increase the levels of p27(Kip1) protein through inhibition of Akt and improvement of FOXO3a activity, in turn inhibited the CDK2 kinase activity, and eventually caused an overall inhibition of HSCs proliferation. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Comparison of three cell block techniques for detection of low frequency abnormal cells

    McCormack M; Hecht SA

    2013-01-01

    Steven A Hecht, Matthew McCormackHologic Inc, Marlborough, MA, USABackground: The Cellient® Automated Cell Block System rapidly creates paraffin-embedded cell blocks by using vacuum filtration to deposit a layer of cells on a filter and infiltrate those cells with reagents and paraffin. This study used a “tracer” cell model to mimic low frequency abnormal cells and compare detection and representative sampling with simple sedimentation, Richard-Allan HistoGel&t...

  14. Mapping of cis-regulatory sites in the promoter of testis-specific stellate genes of Drosophila melanogaster.

    Olenkina, O M; Egorova, K S; Aravin, A A; Naumova, N M; Gvozdev, V A; Olenina, L V

    2012-11-01

    Tandem Stellate genes organized into two clusters in heterochromatin and euchromatin of the X-chromosome are part of the Ste-Su(Ste) genetic system required for maintenance of male fertility and reproduction of Drosophila melanogaster. Stellate genes encode a regulatory subunit of protein kinase CK2 and are the main targets of germline-specific piRNA-silencing; their derepression leads to appearance of protein crystals in spermatocytes, meiotic disturbances, and male sterility. A short promoter region of 134 bp appears to be sufficient for testis-specific transcription of Stellate, and it contains three closely located cis-regulatory elements called E-boxes. By using reporter analysis, we confirmed a strong functionality of the E-boxes in the Stellate promoter for in vivo transcription. Using selective mutagenesis, we have shown that the presence of the central E-box 2 is preferable to maintain a high-level testis-specific transcription of the reporter gene under the Stellate promoter. The Stellate promoter provides transcription even in heterochromatin, and corresponding mRNAs are translated with the generation of full-size protein products in case of disturbances in the piRNA-silencing process. We have also shown for the first time that the activity of the Stellate promoter is determined by chromatin context of the X-chromosome in male germinal cells, and it increases at about twofold when relocating in autosomes.

  15. MeCP2 silencing of LncRNA H19 controls hepatic stellate cell proliferation by targeting IGF1R

    Yang, Jing-Jing; Liu, Li-Ping; Tao, Hui; Hu, Wei; Shi, Peng; Deng, Zi-Yu; Li, Jun

    2016-01-01

    Highlights: • H19 plays a key role in HSCs proliferation and fibrosis. • MeCP2/H19 axis involvement in HSCs activation and fibrosis. • MeCP2 negative controls H19 expression in activated HSCs. • Identification of IGF1R as new target of H19 in HSC. - Abstract: Methyl-CpG-binding protein 2 (MeCP2) plays a key role in liver fibrosis. However, the potential mechanism of MeCP2 in liver fibrosis remains unclear. Early reports suggest that LncRNA H19 is important epigenetic regulator with critical roles in cell proliferation, but its role in hepatic fibrosis remains elusive. Sprague-Dawley rats liver fibrosis was generated by 12-weeks treatment with CCl 4 intraperitoneal injection. HSC-T6 cells were used in vitro study. The expression levels of MeCP2, H19, IGF1R, α-SMA, and Col1A1 were estimated by Western blotting, qRT-PCR and Immunohistochemistry. HSC-T6 cells were transfected with MeCP2-siRNA, pEGF-C1-MeCP2, pEX-3-H19, and H19-siRNA. Finally, cell proliferation ability was assessed by the MTT assay. Here, we found that H19 was significantly down-regulated in HSCs and fibrosis tissues, and an opposite pattern is observed for MeCP2 and IGF1R. Silencing of MeCP2 blocked HSCs proliferation. Knockdown of MeCP2 elevated H19 expression in activated HSCs, and over-expression of MeCP2 inhibited H19 expression in activated HSCs. Moreover, we investigated the effect of H19 on IGF1R expression. Overexpression of H19 in HSCs repressed the expression of IGF1R, and an opposite pattern is observed for H19 silenced. In addition, we reported that overexpression of H19 inhibited the TGF-β1-induced proliferation of HSCs. Furthermore, MeCP2 negative regulation of H19 by targeting the protein IGF1R. Taken together, these results demonstrated that MeCP2 silencing of H19 can alter the IGF1R overexpression, thus contributing to HSCs proliferation. These data could suggest the development of combination therapies that target the MeCP2.

  16. Donor-Acceptor Block Copolymers: Synthesis and Solar Cell Applications

    Kazuhiro Nakabayashi

    2014-04-01

    Full Text Available Fullerene derivatives have been widely used for conventional acceptor materials in organic photovoltaics (OPVs because of their high electron mobility. However, there are also considerable drawbacks for use in OPVs, such as negligible light absorption in the visible-near-IR regions, less compatibility with donor polymeric materials and high cost for synthesis and purification. Therefore, the investigation of non-fullerene acceptor materials that can potentially replace fullerene derivatives in OPVs is increasingly necessary, which gives rise to the possibility of fabricating all-polymer (polymer/polymer solar cells that can deliver higher performance and that are potentially cheaper than fullerene-based OPVs. Recently, considerable attention has been paid to donor-acceptor (D-A block copolymers, because of their promising applications as fullerene alternative materials in all-polymer solar cells. However, the synthesis of D-A block copolymers is still a challenge, and therefore, the establishment of an efficient synthetic method is now essential. This review highlights the recent advances in D-A block copolymers synthesis and their applications in all-polymer solar cells.

  17. Curcumin blocks interleukin-1 signaling in chondrosarcoma cells.

    Thomas Kalinski

    Full Text Available Interleukin (IL-1 signaling plays an important role in inflammatory processes, but also in malignant processes. The essential downstream event in IL-1 signaling is the activation of nuclear factor (NF-κB, which leads to the expression of several genes that are involved in cell proliferation, invasion, angiogenesis and metastasis, among them VEGF-A. As microenvironment-derived IL-1β is required for invasion and angiogenesis in malignant tumors, also in chondrosarcomas, we investigated IL-1β-induced signal transduction and VEGF-A expression in C3842 and SW1353 chondrosarcoma cells. We additionally performed in vitro angiogenesis assays and NF-κB-related gene expression analyses. Curcumin is a substance which inhibits IL-1 signaling very early by preventing the recruitment of IL-1 receptor associated kinase (IRAK to the IL-1 receptor. We demonstrate that IL-1 signaling and VEGF-A expression are blocked by Curcumin in chondrosarcoma cells. We further show that Curcumin blocks IL-1β-induced angiogenesis and NF-κB-related gene expression. We suppose that IL-1 blockade is an additional treatment option in chondrosarcoma, either by Curcumin, its derivatives or other IL-1 blocking agents.

  18. Comparison of three cell block techniques for detection of low frequency abnormal cells

    McCormack M

    2013-01-01

    Full Text Available Steven A Hecht, Matthew McCormackHologic Inc, Marlborough, MA, USABackground: The Cellient® Automated Cell Block System rapidly creates paraffin-embedded cell blocks by using vacuum filtration to deposit a layer of cells on a filter and infiltrate those cells with reagents and paraffin. This study used a “tracer” cell model to mimic low frequency abnormal cells and compare detection and representative sampling with simple sedimentation, Richard-Allan HistoGel™, and Cellient cell block techniques.Methods: Tracer cells were a cultured cell line (CaSki fixed in methanol, prestained in solution with hematoxylin, and quantified using a hemacytometer. Tracer cells were diluted in a 10-fold dilution series ranging from 100 to 0.1 tracer/mL in a background of pooled clinical serous effusion specimens. Ten replicates of each dilution were processed using each cell block method, and the resulting blocks were cut to produce two slides from each block. The slides were deparaffinized, counterstained with eosin, cover-slipped, and screened for the presence of tracer cells. Blocks were considered to be representative of the specimen if tracer cells were detected on either of the slides. If no tracer cells were observed on either slide, the block was recut to generate a third slide. If tracer cells were seen on the third slide, the block was considered representative of the specimen.Results: Tracer cells were identified on the initial slides for 20 of 40 (50.0% simple sedimentation, 21 of 40 (52.5% of HistoGel, and 25 of 40 (62.5% of Cellient cell blocks. Representative sampling of the 1 tracer/mL specimen was 10.0% for simple sedimentation and 30.0% for HistoGel and Cellient. Only Cellient showed representative sampling of the 0.1 tracer/mL specimen.Conclusion: The Cellient System blocks demonstrated representative sampling at the lowest tracer cell concentration compared with simple sedimentation and HistoGel.Keywords: Cellient®, HistoGel™, simple

  19. Modulation of extracellular matrix proteins and hepatate stellate cell activation following gadolinium chloride induced Kuffer cell blockade in an experimental model of liver fibrosis/cirrhosis

    Nilgün Tekkesin

    2013-06-01

    Full Text Available Hepatic fibrosis is now regarded as a common response to chronic liver injury; regardless of its nature (viral infections, alcohol abuse and metal overload. It is also characterized by excessive deposition of extracellular matrix (ECM components. The ECM is a dynamic complex of macromolecules that includes collagens, glycoproteins, and proteoglycans, such as laminin and fibronectin; it has been shown that it does not only support the tissue structure, but also plays a major role in cell adhesion, proliferation, and differentiation. Remodelling of the ECM may be the signal that facilitates lobular reorganization during liver regeneration after a liver injury. Much work has been done concerning the ECM synthesis and protein contents.

  20. Rag Deletion in Peripheral T Cells Blocks TCR Revision

    Hale, J. Scott; Ames, Kristina T.; Boursalian, Tamar E.; Fink, Pamela J.

    2010-01-01

    Mature CD4+Vβ5+ T cells that recognize a peripherally expressed endogenous superantigen are tolerized either by deletion or T cell receptor (TCR) revision. In Vβ5 transgenic mice, this latter tolerance pathway results in the appearance of CD4+Vβ5−TCRβ+ T cells, coinciding with Rag1, Rag2, and TdT expression and the accumulation of Vβ-DJβ recombination intermediates in peripheral CD4+ T cells. Because post-thymic RAG-dependent TCR rearrangement has remained controversial, we sought to definitively determine whether TCR revision is an extrathymic process that occurs in mature peripheral T cells. We now show that Rag deletion in post-positive selection T cells in Vβ5 transgenic mice blocks TCR revision in vivo, and that mature peripheral T cells sorted to remove cells bearing endogenous TCRβ chains can express newly generated TCRβ molecules in adoptive hosts. These findings unambiguously demonstrate post-thymic, RAG-dependent TCR rearrangement and define TCR revision as a tolerance pathway that targets mature peripheral CD4+ T cells. PMID:20435935

  1. Pancreatic stellate cells and CX3CR1: occurrence in normal pancreas and acute and chronic pancreatitis and effect of their activation by a CX3CR1 agonist.

    Uchida, Masahiko; Ito, Tetsuhide; Nakamura, Taichi; Hijioka, Masayuki; Igarashi, Hisato; Oono, Takamasa; Kato, Masaki; Nakamura, Kazuhiko; Suzuki, Koichi; Takayanagi, Ryoichi; Jensen, Robert T

    2014-07-01

    Numerous studies suggest important roles of the chemokine, fractalkine (CX3CL1), in acute/chronic pancreatitis; however, the possible mechanisms of the effects are unclear. Pancreatic stellate cells (PSCs) can play important roles in pancreatitis, secreting inflammatory cytokines/chemokines, as well as proliferation. Therefore, we investigated CX3CL1 receptor (CX3CR1) occurrence in normal pancreas and pancreatitis (acute/chronic) tissues and the effects of CX3CL1 on activated PSCs. CX3CR1 expression/localization in normal pancreas and pancreatitis (acute/chronic) tissues was evaluated with immunohistochemical analysis. CX3CR1 expression and effects of CX3CL1 on activated PSCs were examined with real-time polymerase chain reaction, BrdU (5-bromo-2-deoxyuridine) assays, and Western blotting. In normal pancreas, acinar cells expressed CX3CR1 within granule-like formations in the cytoplasm, whereas in acute/chronic pancreatitis, acinar, ductal, and activated PSCs expressed CX3CR1 on cell membranes. With activation of normal PSCs, CX3CR1 is increased. CX3CL1 activated multiple signaling cascades in PSCs. CX3CL1 did not induce inflammatory genes expression in activated PSCs, but induced proliferation. CX3CR1s are expressed in normal pancreas. Expression is increased in acute/chronic pancreatitis, and the CX3CR1s are activated. CX3CL1 induces proliferation of activated PSCs without increasing release of inflammatory mediators. These results suggest that CX3CR1 activation of PSCs could be important in their effects in pancreatitis, especially to PSC proliferation in pancreatitis where CX3CL1 levels are elevated.

  2. UV light blocks EGFR signalling in human cancer cell lines

    Olsen, BB; Neves-Petersen, M T; Klitgaard, S

    2007-01-01

    UV light excites aromatic residues, causing these to disrupt nearby disulphide bridges. The EGF receptor is rich in aromatic residues near the disulphide bridges. Herein we show that laser-pulsed UV illumination of two different skin-derived cancer cell lines i.e. Cal-39 and A431, which both...... antibodies. There was a threshold level, below which the receptor could not be blocked. In addition, illumination caused the cells to upregulate the cyclin-dependent kinase inhibitor p21WAF1, irrespective of the p53 status. Since the EGF receptor is often overexpressed in cancers and other proliferative skin...... disorders, it might be possible to significantly reduce the proliferative potential of these cells making them good targets for laser-pulsed UV light treatment....

  3. 1,25-(OH)2-vitamin D3 prevents activation of hepatic stellate cells in vitro and ameliorates inflammatory liver damage but not fibrosis in the Abcb4−/− model

    Reiter, Florian P.; Hohenester, Simon; Nagel, Jutta M.; Wimmer, Ralf; Artmann, Renate; Wottke, Lena; Makeschin, Marie-Christine; Mayr, Doris; Rust, Christian; Trauner, Michael; Denk, Gerald U.

    2015-01-01

    Background/Purpose of the study: Vitamin D 3 -deficiency is common in patients with chronic liver-disease and may promote disease progression. Vitamin D 3 -administration has thus been proposed as a therapeutic approach. Vitamin D 3 has immunomodulatory effects and may modulate autoimmune liver-disease such as primary sclerosing cholangitis. Although various mechanisms of action have been proposed, experimental evidence is limited. Here we test the hypothesis that active 1,25-(OH) 2 -vitamin D 3 inhibits activation of hepatic stellate cells (HSC) in vitro and modulates liver-injury in vivo. Methods: Proliferation and activation of primary murine HSC were assessed by BrdU- and PicoGreen ® -assays, immunoblotting, immunofluorescence-microscopy, quantitative-PCR, and zymography following calcitriol-treatment. Wild-type and ATP-binding cassette transporter b4 −/− (Abcb4 −/− )-mice received calcitriol for 4 weeks. Liver-damage, inflammation, and fibrosis were assessed by serum liver-tests, Sirius-red staining, quantitative-PCR, immunoblotting, immunohistochemistry and hydroxyproline quantification. Results: In vitro, calcitriol inhibited activation and proliferation of murine HSC as shown by reduced α-smooth muscle actin and platelet-derived growth factor-receptor-β-protein-levels, BrdU and PicoGreen®-assays. Furthermore, mRNA-levels and activity of matrix metalloproteinase 13 were profoundly increased. In vivo, calcitriol ameliorated inflammatory liver-injury reflected by reduced levels of alanine aminotransferase in Abcb4 −/− -mice. In accordance, their livers had lower mRNA-levels of F4/80, tumor necrosis factor-receptor 1 and a lower count of portal CD11b positive cells. In contrast, no effect on overall fibrosis was observed. Conclusion: Calcitriol inhibits activation and proliferation of HSCs in vitro. In Abcb4 −/− -mice, administration of calcitriol ameliorates inflammatory liver-damage but has no effect on biliary fibrosis after 4 weeks

  4. 1,25-(OH){sub 2}-vitamin D{sub 3} prevents activation of hepatic stellate cells in vitro and ameliorates inflammatory liver damage but not fibrosis in the Abcb4{sup −/−} model

    Reiter, Florian P., E-mail: florian.reiter@med.uni-muenchen.de [Department of Medicine II, Liver Center Munich, University of Munich, Marchioninistr. 15, D-81377 Munich (Germany); Hohenester, Simon; Nagel, Jutta M.; Wimmer, Ralf; Artmann, Renate; Wottke, Lena [Department of Medicine II, Liver Center Munich, University of Munich, Marchioninistr. 15, D-81377 Munich (Germany); Makeschin, Marie-Christine; Mayr, Doris [Institute of Pathology, University of Munich, Thalkirchner Str. 36, D-80337 Munich (Germany); Rust, Christian [Department of Medicine I, Krankenhaus Barmherzige Brüder, Romanstr. 93, D-80639 Munich (Germany); Trauner, Michael [Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna (Austria); Denk, Gerald U. [Department of Medicine II, Liver Center Munich, University of Munich, Marchioninistr. 15, D-81377 Munich (Germany)

    2015-04-03

    Background/Purpose of the study: Vitamin D{sub 3}-deficiency is common in patients with chronic liver-disease and may promote disease progression. Vitamin D{sub 3}-administration has thus been proposed as a therapeutic approach. Vitamin D{sub 3} has immunomodulatory effects and may modulate autoimmune liver-disease such as primary sclerosing cholangitis. Although various mechanisms of action have been proposed, experimental evidence is limited. Here we test the hypothesis that active 1,25-(OH){sub 2}-vitamin D{sub 3} inhibits activation of hepatic stellate cells (HSC) in vitro and modulates liver-injury in vivo. Methods: Proliferation and activation of primary murine HSC were assessed by BrdU- and PicoGreen{sup ®}-assays, immunoblotting, immunofluorescence-microscopy, quantitative-PCR, and zymography following calcitriol-treatment. Wild-type and ATP-binding cassette transporter b4{sup −/−} (Abcb4{sup −/−})-mice received calcitriol for 4 weeks. Liver-damage, inflammation, and fibrosis were assessed by serum liver-tests, Sirius-red staining, quantitative-PCR, immunoblotting, immunohistochemistry and hydroxyproline quantification. Results: In vitro, calcitriol inhibited activation and proliferation of murine HSC as shown by reduced α-smooth muscle actin and platelet-derived growth factor-receptor-β-protein-levels, BrdU and PicoGreen®-assays. Furthermore, mRNA-levels and activity of matrix metalloproteinase 13 were profoundly increased. In vivo, calcitriol ameliorated inflammatory liver-injury reflected by reduced levels of alanine aminotransferase in Abcb4{sup −/−}-mice. In accordance, their livers had lower mRNA-levels of F4/80, tumor necrosis factor-receptor 1 and a lower count of portal CD11b positive cells. In contrast, no effect on overall fibrosis was observed. Conclusion: Calcitriol inhibits activation and proliferation of HSCs in vitro. In Abcb4{sup −/−}-mice, administration of calcitriol ameliorates inflammatory liver-damage but has

  5. Minocycline blocks glial cell activation and ventilatory acclimatization to hypoxia.

    Stokes, Jennifer A; Arbogast, Tara E; Moya, Esteban A; Fu, Zhenxing; Powell, Frank L

    2017-04-01

    Ventilatory acclimatization to hypoxia (VAH) is the time-dependent increase in ventilation, which persists upon return to normoxia and involves plasticity in both central nervous system respiratory centers and peripheral chemoreceptors. We investigated the role of glial cells in VAH in male Sprague-Dawley rats using minocycline, an antibiotic that inhibits microglia activation and has anti-inflammatory properties, and barometric pressure plethysmography to measure ventilation. Rats received either minocycline (45mg/kg ip daily) or saline beginning 1 day before and during 7 days of chronic hypoxia (CH, Pi O 2  = 70 Torr). Minocycline had no effect on normoxic control rats or the hypercapnic ventilatory response in CH rats, but minocycline significantly ( P minocycline administration during only the last 3 days of CH did not reverse VAH. Microglia and astrocyte activation in the nucleus tractus solitarius was quantified from 30 min to 7 days of CH. Microglia showed an active morphology (shorter and fewer branches) after 1 h of hypoxia and returned to the control state (longer filaments and extensive branching) after 4 h of CH. Astrocytes increased glial fibrillary acidic protein antibody immunofluorescent intensity, indicating activation, at both 4 and 24 h of CH. Minocycline had no effect on glia in normoxia but significantly decreased microglia activation at 1 h of CH and astrocyte activation at 24 h of CH. These results support a role for glial cells, providing an early signal for the induction but not maintenance of neural plasticity underlying ventilatory acclimatization to hypoxia. NEW & NOTEWORTHY The signals for neural plasticity in medullary respiratory centers underlying ventilatory acclimatization to chronic hypoxia are unknown. We show that chronic hypoxia activates microglia and subsequently astrocytes. Minocycline, an antibiotic that blocks microglial activation and has anti-inflammatory properties, also blocks astrocyte activation in respiratory

  6. Organic photovoltaic cell incorporating electron conducting exciton blocking layers

    Forrest, Stephen R.; Lassiter, Brian E.

    2014-08-26

    The present disclosure relates to photosensitive optoelectronic devices including a compound blocking layer located between an acceptor material and a cathode, the compound blocking layer including: at least one electron conducting material, and at least one wide-gap electron conducting exciton blocking layer. For example, 3,4,9,10 perylenetetracarboxylic bisbenzimidazole (PTCBI) and 1,4,5,8-napthalene-tetracarboxylic-dianhydride (NTCDA) function as electron conducting and exciton blocking layers when interposed between the acceptor layer and cathode. Both materials serve as efficient electron conductors, leading to a fill factor as high as 0.70. By using an NTCDA/PTCBI compound blocking layer structure increased power conversion efficiency is achieved, compared to an analogous device using a conventional blocking layers shown to conduct electrons via damage-induced midgap states.

  7. Anti-fibrotic effects of Cuscuta chinensis with in vitro hepatic stellate cells and a thioacetamide-induced experimental rat model.

    Kim, Jin Seoub; Koppula, Sushruta; Yum, Mun Jeong; Shin, Gwang Mo; Chae, Yun Jin; Hong, Seok Min; Lee, Jae Dong; Song, MinDong

    2017-12-01

    Cuscuta chinensis Lam. (Convolvulaceae) has been used as a traditional herbal remedy for treating liver and kidney disorders. Anti-fibrotic effects of C. chinensis extract (CCE) in cellular and experimental animal models were investigated. HSC-T6 cell viability, cell cycle and apoptosis were analysed using MTT assay, flow cytometry and Annexin V-FITC/PI staining techniques. Thioacetamide (TAA)-induced fibrosis model was established using Sprague Dawley rats (n = 10). Control, TAA, CCE 10 (TAA with CCE 10 mg/kg), CCE 100 (TAA with CCE 100 mg/kg) and silymarin (TAA with silymarin 50 mg/kg). Fibrosis was induced by TAA (200 mg/kg, i.p.) twice per week for 13 weeks. CCE and silymarin were administered orally two times per week from the 7th to 13th week. Fibrotic related gene expression (α-SMA, Col1α1 and TGF-β1) was measured by RT-PCR. Serum biomarkers, glutathione (GSH) and hydroxyproline were estimated by spectrophotometer using commercial kits. CCE (0.05 and 0.1 mg/mL) and silymarin (0.05 mg/mL) treatment significantly (p < 0.01 and p < 0.001) induced apoptosis (11.56%, 17.52% for CCE; 16.50% for silymarin, respectively) in activated HSC-T6 cells, compared with control group (7.26%). Further, rat primary HSCs showed changes in morphology with CCE 0.1 mg/mL treatment. In in vivo studies, CCE (10 and 100 mg/kg) treatment ameliorated the TAA-induced altered levels of serum biomarkers, fibrotic related gene expression, GSH, hydroxyproline significantly (p < 0.05-0.001) and rescued the histopathological changes. CCE can be developed as a potential agent in the treatment of hepatofibrosis.

  8. Impact of mobility on call block, call drops and optimal cell size in small cell networks

    Ramanath , Sreenath; Voleti , Veeraruna Kavitha; Altman , Eitan

    2011-01-01

    We consider small cell networks and study the impact of user mobility. Assuming Poisson call arrivals at random positions with random velocities, we discuss the characterization of handovers at the boundaries. We derive explicit expressions for call block and call drop probabilities using tools from spatial queuing theory. We also derive expressions for the average virtual server held up time. These expressions are used to derive optimal cell sizes for various profile of velocities in small c...

  9. Protein extraction from methanol fixed paraffin embedded tissue blocks: A new possibility using cell blocks

    Kokkat, Theresa J.; McGarvey, Diane; Patel, Miral S.; Tieniber, Andrew D.; LiVolsi, Virginia A.; Baloch, Zubair W.

    2013-01-01

    Background: Methanol fixed and paraffin embedded (MFPE) cellblocks are an essential cytology preparation. However, MFPE cellblocks often contain limited material and their relatively small size has caused them to be overlooked in biomarker discovery. Advances in the field of molecular biotechnology have made it possible to extract proteins from formalin fixed and paraffin embedded (FFPE) tissue blocks. In contrast, there are no established methods for extracting proteins from MFPE cellblocks. We investigated commonly available CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate) buffer, as well as two commercially available Qiagen® kits and compared their effectiveness on MFPE tissue for protein yields. Materials and Methods: MFPE blocks were made by Cellient™ automated system using human tissue specimens from normal and malignant specimens collected in ThinPrep™ Vials. Protein was extracted from Cellient-methanol fixed and paraffin embedded blocks with CHAPS buffer method as well as FFPE and Mammalian Qiagen® kits. Results: Comparison of protein yields demonstrated the effectiveness of various protein extraction methods on MFPE cellblocks. Conclusion: In the current era of minimally invasive techniques to obtain minimal amount of tissue for diagnostic and prognostic purposes, the use of commercial and lab made buffer on low weight MFPE scrapings obtained by Cellient® processor opens new possibilities for protein biomarker research. PMID:24403950

  10. A droplet-based building block approach for bladder smooth muscle cell (SMC) proliferation

    Xu, F; Moon, S J; Emre, A E; Turali, E S; Song, Y S; Hacking, S A; Demirci, U [Department of Medicine, Bio-Acoustic-MEMS in Medicine (BAMM) Laboratory, Center for Biomedical Engineering, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Nagatomi, J, E-mail: udemirci@rics.bwh.harvard.ed [Department of Bioengineering, Clemson University, Clemson, SC (United States)

    2010-03-15

    Tissue engineering based on building blocks is an emerging method to fabricate 3D tissue constructs. This method requires depositing and assembling building blocks (cell-laden microgels) at high throughput. The current technologies (e.g., molding and photolithography) to fabricate microgels have throughput challenges and provide limited control over building block properties (e.g., cell density). The cell-encapsulating droplet generation technique has potential to address these challenges. In this study, we monitored individual building blocks for viability, proliferation and cell density. The results showed that (i) SMCs can be encapsulated in collagen droplets with high viability (>94.2 +- 3.2%) for four cases of initial number of cells per building block (i.e. 7 +- 2, 16 +- 2, 26 +- 3 and 37 +- 3 cells/building block). (ii) Encapsulated SMCs can proliferate in building blocks at rates that are consistent (1.49 +- 0.29) across all four cases, compared to that of the controls. (iii) By assembling these building blocks, we created an SMC patch (5 mm x 5 mm x 20 mum), which was cultured for 51 days forming a 3D tissue-like construct. The histology of the cultured patch was compared to that of a native rat bladder. These results indicate the potential of creating 3D tissue models at high throughput in vitro using building blocks.

  11. CD47-CAR-T Cells Effectively Kill Target Cancer Cells and Block Pancreatic Tumor Growth.

    Golubovskaya, Vita; Berahovich, Robert; Zhou, Hua; Xu, Shirley; Harto, Hizkia; Li, Le; Chao, Cheng-Chi; Mao, Mike Ming; Wu, Lijun

    2017-10-21

    CD47 is a glycoprotein of the immunoglobulin superfamily that is often overexpressed in different types of hematological and solid cancer tumors and plays important role in blocking phagocytosis, increased tumor survival, metastasis and angiogenesis. In the present report, we designed CAR (chimeric antigen receptor)-T cells that bind CD47 antigen. We used ScFv (single chain variable fragment) from mouse CD47 antibody to generate CD47-CAR-T cells for targeting different cancer cell lines. CD47-CAR-T cells effectively killed ovarian, pancreatic and other cancer cells and produced high level of cytokines that correlated with expression of CD47 antigen. In addition, CD47-CAR-T cells significantly blocked BxPC3 pancreatic xenograft tumor growth after intratumoral injection into NSG mice. Moreover, we humanized mouse CD47 ScFv and showed that it effectively bound CD47 antigen. The humanized CD47-CAR-T cells also specifically killed ovarian, pancreatic, and cervical cancer cell lines and produced IL-2 that correlated with expression of CD47. Thus, CD47-CAR-T cells can be used as a novel cellular therapeutic agent for treating different types of cancer.

  12. [Clinical Value of Cell Block in the Diagnosis of Malignant Pleural Effusion].

    Wang, Xintong; Cheng, Fangyuan; Zhong, Diansheng; Zhang, Lisha; Meng, Fanlu; Shao, Yi; Yu, Tao

    2017-06-20

    Malignant pleural effusion (MPE) is due tumor which arises from the mesothelium or metastases from tumor origniating other sites. Generally, the prognosis of MPE is poor, in the premise of reducing the pain of patients, as soon as possible make clear the property of pleural effusion and cause of the disesease, rightly and quickly, providing effective information for subsequent treatment. The cell block of 103 patients by using natural sedimentation or plasma coagulation method combined with HE staining and immunohistochemical staining method maked clear diagnosis and compared with other methods. 90 patients were diagnosed by cell block section from 103 patients who had MPE (diagnostic rate 87.4%); 32 cases were diagnosed by cell block section only, 74 cases pointed out that the pathological type , 23 cases even pointed out the primary lesions; 71 cases examined other invasive methods at the same time, the diagnostic rate was 87.3% and 81.7%; the detection rate of cell block section and cytological smear in detecting malignant tumor cells was 86.7%and 44.0% respectively. Cell block can not only increase the diagnosis, in contrast to cytological smear, and own the same diagnostic rate compared with other invasive methods, but also can confirm pathological type and primary lesion; especially, for other invasive methods, cell block method is a preferable complementary method, and that cell block method maybe the only way for some patients.

  13. Rare Coumarins Induce Apoptosis, G1 Cell Block and Reduce RNA Content in HL60 Cells

    Widelski Jarosław

    2017-02-01

    Full Text Available The rare coumarins stenocarpin, stenocarpin isobutyrate, oficinalin, oficinalin isobutyrate, 8-methoxypeucedanin and the known xanthotoxin, isoimperatorin, bergapten, peucedanin and 8–methoxyisoimperatorin were isolated from Peucedanum luxurians Tamamsch. (Apiaceae and identified by means of spectral data (1D and 2D NMR. Their immunomodulating activity was evaluated by flow cytometry and their influence on HL60 cells as well as on PHA-stimulated PBLs was tested. All tested coumarins induce apoptosis (maximal in the 48 h culture and decrease cell proliferation in a time- and dose-dependent manner, especially in HL60 cells. They also induce partial G1 block, but only in HL60 cells (at 100 µM concentrations. Dose-dependent reduction of RNA content was also found in G1 cells treated by the coumarins. All of the tested coumarins also possessed immunomodulatory activities. Bergapten and xanthotoxin were found to be the best candidates for further evaluation as anti-cancer drugs.

  14. Utility of Cytospin and Cell block Technology in Evaluation of Body Fluids and Urine Samples: A Comparative Study.

    Qamar, Irmeen; Rehman, Suhailur; Mehdi, Ghazala; Maheshwari, Veena; Ansari, Hena A; Chauhan, Sunanda

    2018-01-01

    Cytologic examination of body fluids commonly involves the use of direct or sediment smears, cytocentrifuge preparations, membrane filter preparations, or cell block sections. Cytospin and cell block techniques are extremely useful in improving cell yield of thin serous effusions and urine samples, and ensure high diagnostic efficacy. We studied cytospin preparations and cell block sections prepared from 180 samples of body fluids and urine samples to compare the relative efficiency of cell retrieval, preservation of cell morphology, ease of application of special stains, and diagnostic efficacy. Samples were collected and processed to prepare cytospin smears and cell block sections. We observed that overall, cell yield and preservation of individual cell morphology were better in cytospin preparations as compared to cell blocks, while preservation of architectural pattern was better in cell block sections. The number of suspicious cases also decreased on cell block sections, with increased detection of malignancy. It was difficult to prepare cell blocks from urine samples due to low cellularity. Cytospin technology is a quick, efficient, and cost-effective method of increasing cell yield in hypocellular samples, with better preservation of cell morphology. Cell blocks are better prepared from high cellularity fluids; however, tissue architecture is better studied, with improved rate of diagnosis and decrease in ambiguous results. Numerous sections can be prepared from a small amount of material. Special stains and immunochemical stains can be easily applied to cell blocks. It also provides a source of archival material.

  15. The State of Cell Blocks and Ancillary Testing: Past, Present, and Future.

    Saqi, Anjali

    2016-12-01

    Cell blocks are an integral part of cytology, but their utility is recognized probably more now than ever before, largely owing to the significant role they play in ancillary testing, particularly molecular diagnostics. Modifications to improve the cell block method initially introduced more than a century ago have been made over the years. Though their value is acknowledged and they are widely used across laboratories, cell block preparations are not standardized and results of ancillary testing performed on them are inconsistent. This article reviews the state of cell blocks-summarizes the more common, currently available and used methods and their corresponding advantages and shortcomings, outlines the role of alternative techniques (eg, smears), and proposes methods to optimize results.

  16. Inhibition of host cell translation elongation by Legionella pneumophila blocks the host cell unfolded protein response.

    Hempstead, Andrew D; Isberg, Ralph R

    2015-12-08

    Cells of the innate immune system recognize bacterial pathogens by detecting common microbial patterns as well as pathogen-specific activities. One system that responds to these stimuli is the IRE1 branch of the unfolded protein response (UPR), a sensor of endoplasmic reticulum (ER) stress. Activation of IRE1, in the context of Toll-like receptor (TLR) signaling, induces strong proinflammatory cytokine induction. We show here that Legionella pneumophila, an intravacuolar pathogen that replicates in an ER-associated compartment, blocks activation of the IRE1 pathway despite presenting pathogen products that stimulate this response. L. pneumophila TLR ligands induced the splicing of mRNA encoding XBP1s, the main target of IRE1 activity. L. pneumophila was able to inhibit both chemical and bacterial induction of XBP1 splicing via bacterial translocated proteins that interfere with host protein translation. A strain lacking five translocated translation elongation inhibitors was unable to block XBP1 splicing, but this could be rescued by expression of a single such inhibitor, consistent with limitation of the response by translation elongation inhibitors. Chemical inhibition of translation elongation blocked pattern recognition receptor-mediated XBP1 splicing, mimicking the effects of the bacterial translation inhibitors. In contrast, host cell-promoted inhibition of translation initiation in response to the pathogen was ineffective in blocking XBP1 splicing, demonstrating the need for the elongation inhibitors for protection from the UPR. The inhibition of host translation elongation may be a common strategy used by pathogens to limit the innate immune response by interfering with signaling via the UPR.

  17. Block Copolymers for Alkaline Fuel Cell Membrane Materials

    2014-07-30

    temperature fuel cells including proton exchange membrane fuel cell ( PEMFC ) and alkaline fuel cell (AFC) with operation temperature usually lower than 120...advantages over proton exchange membrane fuel cells ( PEMFCs ) resulting in the popularity of AFCs in the US space program.[8-11] The primary benefit AFC...offered over PEMFC is better electrochemical kinetics on the anode and cathode under the alkaline environment, which results in the ability to use

  18. Innate lymphoid cells: the new kids on the block.

    Withers, David R; Mackley, Emma C; Jones, Nick D

    2015-08-01

    The purpose of this article is to review recent advances in our understanding of innate lymphoid cell function and to speculate on how these cells may become activated and influence the immune response to allogeneic tissues and cells following transplantation. Innate lymphoid cells encompass several novel cell types whose wide-ranging roles in the immune system are only now being uncovered. Through cytokine production, cross-talk with both haematopoietic and nonhaematopoietic populations and antigen presentation to T cells, these cells have been shown to be key regulators in maintaining tissue integrity, as well as initiating and then sustaining immune responses. It is now clear that innate lymphoid cells markedly contribute to immune responses and tissue repair in a number of disease contexts. Although experimental and clinical data on the behaviour of these cells following transplantation are scant, it is highly likely that innate lymphoid cells will perform similar functions in the alloimmune response following transplantation and therefore may be potential therapeutic targets for manipulation to prevent allograft rejection.

  19. RoBlock: a prototype autonomous manufacturing cell

    Baekdal, Lars K.; Balslev, Ivar; Eriksen, Rene D.; Jensen, Soren P.; Jorgensen, Bo N.; Kirstein, Brian; Kristensen, Bent B.; Olsen, Martin M.; Perram, John W.; Petersen, Henrik G.; Petersen, Morten L.; Ruhoff, Peter T.; Skjolstrup, Carl E.; Sorensen, Anders S.; Wagenaar, Jeroen M.

    2000-10-01

    RoBlock is the first phase of an internally financed project at the Institute aimed at building a system in which two industrial robots suspended from a gantry, as shown below, cooperate to perform a task specified by an external user, in this case, assembling an unstructured collection of colored wooden blocks into a specified 3D pattern. The blocks are identified and localized using computer vision and grasped with a suction cup mechanism. Future phases of the project will involve other processes such as grasping and lifting, as well as other types of robot such as autonomous vehicles or variable geometry trusses. Innovative features of the control software system include: The use of an advanced trajectory planning system which ensures collision avoidance based on a generalization of the method of artificial potential fields, the use of a generic model-based controller which learns the values of parameters, including static and kinetic friction, of a detailed mechanical model of itself by comparing actual with planned movements, the use of fast, flexible, and robust pattern recognition and 3D-interpretation strategies, integration of trajectory planning and control with the sensor systems in a distributed Java application running on a network of PC's attached to the individual physical components. In designing this first stage, the aim was to build in the minimum complexity necessary to make the system non-trivially autonomous and to minimize the technological risks. The aims of this project, which is planned to be operational during 2000, are as follows: To provide a platform for carrying out experimental research in multi-agent systems and autonomous manufacturing systems, to test the interdisciplinary cooperation architecture of the Maersk Institute, in which researchers in the fields of applied mathematics (modeling the physical world), software engineering (modeling the system) and sensor/actuator technology (relating the virtual and real worlds) could

  20. Retinal bipolar cells: elementary building blocks of vision.

    Euler, Thomas; Haverkamp, Silke; Schubert, Timm; Baden, Tom

    2014-08-01

    Retinal bipolar cells are the first ‘projection neurons’ of the vertebrate visual system—all of the information needed for vision is relayed by this intraretinal connection. Each of the at least 13 distinct types of bipolar cells systematically transforms the photoreceptor input in a different way, thereby generating specific channels that encode stimulus properties, such as polarity, contrast, temporal profile and chromatic composition. As a result, bipolar cell output signals represent elementary ‘building blocks’ from which the microcircuits of the inner retina derive a feature-oriented description of the visual world.

  1. Fine needle aspiration cytology and cell block in the diagnosis of seminoma testis

    Abhishant Pandey

    2011-01-01

    Full Text Available Testicular neoplasms which show a wide variety of morphologic types, comprise a small proportion of malignancies. Early identification and treatment is essential for achieving long term survival. The cytologic findings in fine needle aspiration smears from left testicular swelling of a 49 year old male suggestive of a germ cell tumor was complimented by cell block preparation as seminoma. This was confirmed by histopathologic studies. We are presenting this case to emphasize that cell block can be used for diagnosis of testicular tumors.

  2. Optical properties and sensing applications of stellated and bimetallic nanoparticles

    Smith, Alison F.

    This dissertation focuses on developing guidelines to aid in the design of new bimetallic platforms for sensing applications. Stellated metal nanostructures are a class of plasmonic colloids in which large electric field enhancements can occur at sharp features, making them excellent candidates for surface enhanced Raman spectroscopy (SERS) and surface enhanced infrared spectroscopy (SE-IRS) platforms. Shape-dependent rules for convex polyhedra such as cubes or octahedra exist, which describe far-field scattering and near-field enhancements. However, such rules are lacking for their concave (stellated) counterparts. This dissertation presents the optical response of stellated Au nanocrystals with Oh, D4h, D3h, C2v, and T d symmetry, which were modeled to systematically investigate the role of symmetry, branching, and particle orientation with respect to excitation source using finite difference time domain (FDTD) calculations. Expanding on stellated nanostructures, bimetallic compositions introduce an interplay between overall architecture and composition to provide tunable optical properties and the potential of new functionality. However, decoupling the complex compositional and structural contributions to the localized surface plasmon resonance (LSPR) remains a challenge, especially when the monometallic counterparts are not synthetically accessible for comparison and the theoretical tools for capturing gradient compositions are lacking. This dissertation explores a stellated Au-Pd nanocrystal model system with Oh symmetry to decouple structural and complex compositional effects on LSPR. (Abstract shortened by ProQuest.).

  3. G2-block after irradiation of cells with different p53 status

    Zoelzer, Friedo; Jagetia, Ganesh; Streffer, Christian

    2014-01-01

    Although it is clear that functional p53 is not required for radiation-induced G 2 block, certain experimental findings suggest a role for p53 in this context. For instance, as we also confirm here, the maximum accumulation in the G 2 compartment after X-ray exposure occurs much later in p53 mutants than in wild types. It remains to be seen, however, whether this difference is due to a longer block in the G 2 phase itself. We observed the movement of BrdU-labeled cells through G 2 and M into G 1 . From an analysis of the fraction of labeled cells that entered the second posttreatment cell cycle, we were able to determine the absolute duration of the G 2 and M phases in unirradiated and irradiated cells. Our experiments with four cell lines, two melanomas and two squamous carcinomas, showed that the radiation-induced delay of transition through the G 2 and M phases did not correlate with p53 status. We conclude that looking at the accumulation of cells in the G 2 compartment alone is misleading when differences in the G 2 block are investigated and that the G 2 block itself is indeed independent of functional p53. (orig.) [de

  4. Effect of blocking Rac1 expression in cholangiocarcinoma QBC939 cells

    Liu Xudong

    2011-05-01

    Full Text Available Cholangiocarcinomas (CCs are malignant tumors that originate from epithelial cells lining the biliary tree and gallbladder. Ras correlative C3 creotoxin substrate 1 (Rac1, a small guanosine triphosphatase, is a critical mediator of various aspects of endothelial cell functions. The objective of the present investigation was to study the effect of blocking Rac1 expression in CCs. Seventy-four extrahepatic CC (ECC specimens and matched adjacent normal mucosa were obtained from the Department of Pathology, Inner Mongolia Medicine Hospital, between 2007 and 2009. Our results showed that the expression of Rac1 was significantly higher (53.12% in tumor tissues than in normal tissues. Western blotting data indicated a significant reduction in Rac1-miRNA cell protein levels. Rac1-miRNA cell growth rate was significantly different at 24, 48, and 72 h after transfection. Flow cytometry analysis showed that Rac1-miRNA cells undergo apoptosis more effectively than control QBC939 cells. Blocking Rac1 expression by RNAi effectively inhibits the growth of CCs. miRNA silencing of the Rac1 gene suppresses proliferation and induces apoptosis of QBC939 cells. These results suggest that Rac1 may be a new gene therapy target for CC. Blocking Rac1 expression in CC cells induces apoptosis of these tumor cells and may thus represent a new therapeutic approach.

  5. Neurotrophic and X-ray blocks in the blastemal cell cycle

    Maden, M.

    1979-01-01

    Using microdensitometry techniques the points in the cycle where blastemal cells become blocked after X-irradiation or denervation of the regenerating amphibian limb have been identified. X-irradiation blocks cells in both G 1 and G 2 and those cells that were in S at the time of irradiation presumably proceed to G 2 . After denervation, however, cells accumulate only in G 1 and those that were in S or G 2 continue through the cycle to the next G 1 . The latter results are clearly contradictory to a recent theory proposing a G 2 neurotrophic control of blastemal cells and a solution to the contradiction is presented in the light of the recent results. (author)

  6. TARGETED STELLATE DECENTRALIZATION: IMPLICATIONS FOR SYMPATHETIC CONTROL OF VENTRICULAR ELECTROPHYSIOLOGY

    Buckley, Una; Yamakawa, Kentaro; Takamiya, Tatsuo; Armour, J. Andrew; Shivkumar, Kalyanam; Ardell, Jeffrey L.

    2015-01-01

    Background Selective, bilateral cervicothoracic sympathectomy has proven to be effective for managing ventricular arrhythmias in the setting of structural heart disease. The procedure currently employed removes the caudal portions of both stellate ganglia, along with thoracic chain ganglia down to T4 ganglia. Objective To define the relative contributions of T1-T2 and the T3-T4 paravertebral ganglia in modulating ventricular electrical function. Methods In anesthetized vagotomised porcine subjects (n=8), the heart was exposed via sternotomy along with right and left paravertebral sympathetic ganglia to the T4 level. A 56-electrode epicardial sock was placed over both ventricles to assess epicardial activation recovery intervals (ARI) in response to individually stimulating right and left stellate vs T3 paravertebral ganglia. Responses to T3 stimuli were repeated following surgical removal of the caudal portions of stellate ganglia and T2 bilaterally. Results In intact preparations, stellate ganglion vs T3 stimuli (4Hz, 4ms duration) were titrated to produce equivalent decreases in global ventricular ARIs (right-side 85±6 vs 55±10 ms; left-side 24±3 vs 17±7 ms). Threshold of stimulus intensity applied to T3 ganglia to achieve threshold was 3 times that of T1 threshold. ARIs in unstimulated states were unaffected by bilateral stellate-T2 ganglion removal. Following acute decentralization, T3 stimulation failed to change ARIs. Conclusion Preganglionic sympathetic efferents arising from the T1-T4 spinal cord that project to the heart transit through stellate ganglia via the paravertebral chain. T1-T2 surgical excision is thus sufficient to functionally interrupt central control of peripheral sympathetic efferent activity. PMID:26282244

  7. Suitability of the Cellient (TM) cell block method for diagnosing soft tissue and bone tumors

    Song, W.; van Hemel, B. M.; Suurmeijer, A. J. H.

    BACKGROUNDThe diagnosis of tumors of soft tissue and bone (STB) heavily relies on histological biopsies, whereas cytology is not widely used. Cellient(TM) cell blocks often contain small tissue fragments. In addition to Hematoxylin and Eosin (H&E) interpretation of histological features,

  8. Block copolymer directed synthesis of mesoporous TiO 2 for dye-sensitized solar cells

    Nedelcu, Mihaela; Lee, Jinwoo; Crossland, Edward J. W.; Warren, Scott C.; Orilall, M. Christopher; Guldin, Stefan; Hü ttner, Sven; Ducati, Catarina; Eder, Dominik; Wiesner, Ulrich; Steiner, Ullrich; Snaith, Henry J.

    2009-01-01

    The morphology of TiO2 plays an important role in the operation of solid-state dye-sensitized solar cells. By using polyisoprene-block- ethyleneoxide (PI-b-PEO) copolymers as structure directing agents for a sol-gel based synthesis of mesoporous TiO

  9. Electrochemical Characterization of TiO 2 Blocking Layers for Dye-Sensitized Solar Cells

    Kavan, Ladislav

    2014-07-31

    Thin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from the substrate (FTO or Ti) with the hole-conducting medium at this interface. The quality of blocking is evaluated electrochemically by methylviologen, ferro/ferricyanide, and spiro-OMeTAD as the model redox probes. Two types of pinholes in the blocking layers are classified, and their effective area is quantified. Frequency-independent Mott-Schottky plots are fitted from electrochemical impedance spectroscopy. Certain films of the thicknesses of several nanometers allow distinguishing the depletion layer formation both in the TiO2 film and in the FTO substrate underneath the titania film. The excellent blocking function of thermally oxidized Ti, electrodeposited film (60 nm), and atomic-layer-deposited films (>6 nm) is documented by the relative pinhole area of less than 1%. However, the blocking behavior of electrodeposited and atomic-layer-deposited films is strongly reduced upon calcination at 500 °C. The blocking function of spray-pyrolyzed films is less good but also less sensitive to calcination. The thermally oxidized Ti is well blocking and insensitive to calcination. © 2014 American Chemical Society.

  10. Reduction of radiation-induced cell cycle blocks by caffeine does not necessarily lead to increased cell killing

    Musk, S.R. (Institute of Cancer Research, Sutton, Surrey (England))

    1991-03-01

    The effect of caffeine upon the radiosensitivities of three human tumor lines was examined and correlated with its action upon the radiation-induced S-phase and G2-phase blocks. Caffeine was found to reduce at least partially the S-phase and G2-phase blocks in all the cell lines examined but potentiated cytotoxicity in only one of the three tumor lines. That reductions have been demonstrated to occur in the absence of increased cell killing provides supporting evidence for the hypothesis that reductions may not be causal in those cases when potentiation of radiation-induced cytotoxicity is observed in the presence of caffeine.

  11. Proliferative and Invasive Effects of Progesterone-Induced Blocking Factor in Human Glioblastoma Cells

    Araceli Gutiérrez-Rodríguez

    2017-01-01

    Full Text Available Progesterone-induced blocking factor (PIBF is a progesterone (P4 regulated protein expressed in different types of high proliferative cells including astrocytomas, the most frequent and aggressive brain tumors. It has been shown that PIBF increases the number of human astrocytoma cells. In this work, we evaluated PIBF regulation by P4 and the effects of PIBF on proliferation, migration, and invasion of U87 and U251 cells, both derived from human glioblastomas. PIBF mRNA expression was upregulated by P4 (10 nM from 12 to 24 h. Glioblastoma cells expressed two PIBF isoforms, 90 and 57 kDa. The content of the shorter isoform was increased by P4 at 24 h, while progesterone receptor antagonist RU486 (10 μM blocked this effect. PIBF (100 ng/mL increased the number of U87 cells on days 4 and 5 of treatment and induced cell proliferation on day 4. Wound-healing assays showed that PIBF increased the migration of U87 (12–48 h and U251 (24 and 48 h cells. Transwell invasion assays showed that PIBF augmented the number of invasive cells in both cell lines at 24 h. These data suggest that PIBF promotes proliferation, migration, and invasion of human glioblastoma cells.

  12. Anti-S100A4 antibody suppresses metastasis formation by blocking stroma cell invasion

    Klingelhöfer, Jörg; Grum-Schwensen, Birgitte; Beck, Mette K

    2012-01-01

    microenvironment, making it an attractive target for anti-cancer therapy. In this study, we produced a function-blocking anti-S100A4 monoclonal antibody with metastasis-suppressing activity. Antibody treatment significantly reduced metastatic burden in the lungs of experimental animals by blocking the recruitment...... of T cells to the site of the primary tumor. In vitro studies demonstrated that this antibody efficiently reduced the invasion of T cells in a fibroblast monolayer. Moreover, it was capable of suppressing the invasive growth of human and mouse fibroblasts. We presume therefore that the antibody exerts...... its activity by suppressing stroma cell recruitment to the site of the growing tumor. Our epitope mapping studies suggested that the antibody recognition site overlaps with the target binding interface of human S100A4. We conclude here that this antibody could serve as a solid basis for development...

  13. Polystyrene-block-Poly(ionic liquid) Copolymers as Work Function Modifiers in Inverted Organic Photovoltaic Cells.

    Park, Jong Baek; Isik, Mehmet; Park, Hea Jung; Jung, In Hwan; Mecerreyes, David; Hwang, Do-Hoon

    2018-02-07

    Interfacial layers play a critical role in building up the Ohmic contact between electrodes and functional layers in organic photovoltaic (OPV) solar cells. These layers are based on either inorganic oxides (ZnO and TiO 2 ) or water-soluble organic polymers such as poly[(9,9-dioctyl-2,7-fluorene)-alt-(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)] and polyethylenimine ethoxylated (PEIE). In this work, we have developed a series of novel poly(ionic liquid) nonconjugated block copolymers for improving the performance of inverted OPV cells by using them as work function modifiers of the indium tin oxide (ITO) cathode. Four nonconjugated polyelectrolytes (n-CPEs) based on polystyrene and imidazolium poly(ionic liquid) (PSImCl) were synthesized by reversible addition-fragmentation chain transfer polymerization. The ratio of hydrophobic/hydrophilic block copolymers was varied depending on the ratio of polystyrene to the PSImCl block. The ionic density, which controls the work function of the electrode by forming an interfacial dipole between the electrode and the block copolymers, was easily tuned by simply changing the PSImCl molar ratio. The inverted OPV device with the ITO/PS 29 -b-PSImCl 60 cathode achieved the best power conversion efficiency (PCE) of 7.55% among the synthesized block copolymers, exhibiting an even higher PCE than that of the reference OPV device with PEIE (7.30%). Furthermore, the surface properties of the block copolymers films were investigated by contact angle measurements to explore the influence of the controlled hydrophobic/hydrophilic characters on the device performances.

  14. Cytokinesis is blocked in mammalian cells transfected with Chlamydia trachomatis gene CT223

    Weeks Sara K

    2009-01-01

    Full Text Available Abstract Background The chlamydiae alter many aspects of host cell biology, including the division process, but the molecular biology of these alterations remains poorly characterized. Chlamydial inclusion membrane proteins (Incs are likely candidates for direct interactions with host cell cytosolic proteins, as they are secreted to the inclusion membrane and exposed to the cytosol. The inc gene CT223 is one of a sequential set of orfs that encode or are predicted to encode Inc proteins. CT223p is localized to the inclusion membrane in all tested C. trachomatis serovars. Results A plasmid transfection approach was used to examine the function of the product of CT223 and other Inc proteins within uninfected mammalian cells. Fluorescence microscopy was used to demonstrate that CT223, and, to a lesser extent, adjacent inc genes, are capable of blocking host cell cytokinesis and facilitating centromere supranumeracy defects seen by others in chlamydiae-infected cells. Both phenotypes were associated with transfection of plasmids encoding the carboxy-terminal tail of CT223p, a region of the protein that is likely exposed to the cytosol in infected cells. Conclusion These studies suggest that certain Inc proteins block cytokinesis in C. trachomatis-infected cells. These results are consistent with the work of others showing chlamydial inhibition of host cell cytokinesis.

  15. Fourier analysis of cell-wise Block-Jacobi splitting in two-dimensional geometry

    Rosa, M.; Warsa, J. S.; Kelley, T. M.

    2009-01-01

    A Fourier analysis is conducted in two-dimensional (2D) geometry for the discrete ordinates (S N ) approximation of the neutron transport problem solved with Richardson iteration (Source Iteration) using the cell-wise Block-Jacobi (BJ) algorithm. The results of the Fourier analysis show that convergence of cell-wise BJ can degrade, leading to a spectral radius equal to 1, in problems containing optically thin cells. For problems containing cells that are optically thick, instead, the spectral radius tends to 0. Hence, in the optically thick-cell regime, cell-wise BJ is rapidly convergent even for problems that are scattering dominated, with a scattering ratio c close to 1. (authors)

  16. Nanomimics of host cell membranes block invasion and expose invasive malaria parasites.

    Najer, Adrian; Wu, Dalin; Bieri, Andrej; Brand, Françoise; Palivan, Cornelia G; Beck, Hans-Peter; Meier, Wolfgang

    2014-12-23

    The fight against most infectious diseases, including malaria, is often hampered by the emergence of drug resistance and lack or limited efficacies of vaccines. Therefore, new drugs, vaccines, or other strategies to control these diseases are needed. Here, we present an innovative nanotechnological strategy in which the nanostructure itself represents the active substance with no necessity to release compounds to attain therapeutic effect and which might act in a drug- and vaccine-like dual function. Invasion of Plasmodium falciparum parasites into red blood cells was selected as a biological model for the initial validation of this approach. Stable nanomimics-polymersomes presenting receptors required for parasite attachment to host cells-were designed to efficiently interrupt the life cycle of the parasite by inhibiting invasion. A simple way to build nanomimics without postformation modifications was established. First, a block copolymer of the receptor with a hydrophobic polymer was synthesized and then mixed with a polymersome-forming block copolymer. The resulting nanomimics bound parasite-derived ligands involved in the initial attachment to host cells and they efficiently blocked reinvasion of malaria parasites after their egress from host cells in vitro. They exhibited efficacies of more than 2 orders of magnitude higher than the soluble form of the receptor, which can be explained by multivalent interactions of several receptors on one nanomimic with multiple ligands on the infective parasite. In the future, our strategy might offer interesting treatment options for severe malaria or a way to modulate the immune response.

  17. Retention of CXCR4 in the endoplasmic reticulum blocks dissemination of a T cell hybridoma.

    Zeelenberg, I S; Ruuls-Van Stalle, L; Roos, E

    2001-07-01

    The dissemination of T cell hybridomas to multiple nonhematopoietic tissues is blocked by pertussis toxin, suggesting the involvement of a chemokine. To study whether this chemokine is SDF-1, we employed a strategy proposed previously for gene therapy of AIDS, whereby the SDF-1 receptor CXCR4 (also a coreceptor for HIV) is retained in the endoplasmic reticulum (ER) and fails to reach the cell surface. We transfected SDF-1, carrying an ER retention sequence, into a T cell hybridoma. This altered chemokine is retained in the ER, where it binds CXCR4 and prevents the latter protein from reaching the surface. These cells failed to migrate toward SDF-1 or to invade fibroblast monolayers, although they could still migrate toward thymus and activation-regulated chemokine (TARC) and invade TARC-treated monolayers. Furthermore, the ability of the transfected cells to disseminate to multiple organs upon intravenous injection into mice was abolished. This dissemination reflects the in vivo migration patterns of activated and memory T cells into nonhematopoietic tissues, which is thus likely to depend on CXCR4. Attempts to block CXCR4 function as a therapy for AIDS may affect this migration with consequences for T cell function. Our results also suggest a decisive role for CXCR4 in the dissemination of hematopoietic malignancies expressing this receptor.

  18. Distinct apoptotic blocks mediate resistance to panHER inhibitors in HER2+ breast cancer cells.

    Karakas, Bahriye; Ozmay, Yeliz; Basaga, Huveyda; Gul, Ozgur; Kutuk, Ozgur

    2018-05-04

    Despite the development of novel targeted therapies, de novo or acquired chemoresistance remains a significant factor for treatment failure in breast cancer therapeutics. Neratinib and dacomitinib are irreversible panHER inhibitors, which block their autophosphorylation and downstream signaling. Moreover, neratinib and dacomitinib have been shown to activate cell death in HER2-overexpressing cell lines. Here we showed that increased MCL1 and decreased BIM and PUMA mediated resistance to neratinib in ZR-75-30 and SKBR3 cells while increased BCL-XL and BCL-2 and decreased BIM and PUMA promoted neratinib resistance in BT474 cells. Cells were also cross-resistant to dacomitinib. BH3 profiles of HER2+ breast cancer cells efficiently predicted antiapoptotic protein dependence and development of resistance to panHER inhibitors. Reactivation of ERK1/2 was primarily responsible for acquired resistance in SKBR3 and ZR-75-30 cells. Adding specific ERK1/2 inhibitor SCH772984 to neratinib or dacomitinib led to increased apoptotic response in neratinib-resistant SKBR3 and ZR-75-30 cells, but we did not detect a similar response in neratinib-resistant BT474 cells. Accordingly, suppression of BCL-2/BCL-XL by ABT-737 was required in addition to ERK1/2 inhibition for neratinib- or dacomitinib-induced apoptosis in neratinib-resistant BT474 cells. Our results showed that different mitochondrial apoptotic blocks mediated acquired panHER inhibitor resistance in HER2+ breast cancer cell lines as well as highlighted the potential of BH3 profiling assay in prediction of panHER inhibitor resistance in breast cancer cells. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Phenotypic characterization of mononuclear inflammatory cells following equine hydroxyapatite/collagen block grafting in rats

    Alsuwaiyan, Asim; Wang, Bing-Yan; Cohen, Robert E

    2012-01-01

    To measure the inflammatory changes associated with the implantation of an equine hydroxyapatite and collagen-containing block graft (eHAC block) in a rodent model system, an eHAC block graft was implanted subcutaneously in rats. Control groups included saline, turpentine oil, and human mineralized particulate allograft (hMPA). Animals were sacrificed and tissue samples obtained after three days, as well as after 1, 2, 4 and 8 weeks. A panel of immunologic probes was used to identify circulatory monocytic cells (ED1), resident mononuclear phagocytes (ED2), mononuclear phagocytes of lymphoid origin (ED3), expression of Ia antigen (OX6), T-cells (OX19), and B-cells (OX33). Immunocytochemical localization was performed and mononuclear cells localized with each immunologic probe counted. Rat sera obtained after eight weeks were used for nitrocellulose dot-blotting to assess circulating anti-equine immunoglobulins. Statistical analysis was performed using two-way analysis of variance, in conjunction with the Bonferroni correction to account for multiple comparisons. A transient increase in monocytes at 3 days and 1 week was observed in all groups, but was significantly higher in the turpentine control (P < 0.0001). A significant increase in the numbers of mononuclear cells detected with clones ED2 and ED3 was observed in specimens from the turpentine group, in contrast to the other groups in the 3 day to 4 week interval (P < 0.0001), as well as within all time periods (P < 0.0001). A statistically significant difference in numbers of ED3-positive cells was observed in the hMPA group compared to the saline and the eHAC block groups after one week (P < 0.0001). Significantly more OX6-positive cells were observed in the turpentine group, compared to other groups (3 days to 1 week; P < 0.0001). T-lymphocytes were essentially absent except for rats given turpentine (after 1 week). No B-lymphocyte response was found and none of the rats developed systemic anti

  20. In Vitro Model for Predicting the Protective Effect of Ultraviolet-Blocking Contact Lens in Human Corneal Epithelial Cells.

    Abengózar-Vela, Antonio; Arroyo, Cristina; Reinoso, Roberto; Enríquez-de-Salamanca, Amalia; Corell, Alfredo; González-García, María Jesús

    2015-01-01

    To develop an in vitro method to determine the protective effect of UV-blocking contact lenses (CLs) in human corneal epithelial (HCE) cells exposed to UV-B radiation. SV-40-transformed HCE cells were covered with non-UV-blocking CL, UV-blocking CL or not covered, and exposed to UV-B radiation. As control, HCE cells were covered with both types of CLs or not covered, but not exposed to UV-B radiation. Cell viability at 24, 48 and 72 h, after UV-B exposure and removing CLs, was determined by alamarBlue(®) assay. Percentage of live, dead and apoptotic cells was also assessed by flow cytometry after 24 h of UV-B exposure. Intracellular reactive oxygen species (ROS) production after 1 h of exposure was assessed using the dye H(2)DCF-DA. Cell viability significantly decreased, apoptotic cells and intracellular ROS production significantly increased when UVB-exposed cells were covered with non-UV-blocking CL or not covered compared to non-irradiated cells. When cells were covered with UV-blocking CL, cell viability significantly increased and apoptotic cells and intracellular ROS production did not increase compared to exposed cells. UV-B radiation induces cell death by apoptosis, increases ROS production and decreases viable cells. UV-blocking CL is able to avoid these effects increasing cell viability and protecting HCE cells from apoptosis and ROS production induced by UV-B radiation. This in vitro model is an alternative to in vivo methods to determine the protective effect of UV-blocking ophthalmic biomaterials because it is a quicker, cheaper and reliable model that avoids the use of animals.

  1. Thermally induced structural evolution and performance of mesoporous block copolymer-directed alumina perovskite solar cells.

    Tan, Kwan Wee

    2014-04-11

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI(3-x)Cl(x)) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI(3-x)Cl(x) material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance.

  2. Thermally induced structural evolution and performance of mesoporous block copolymer-directed alumina perovskite solar cells.

    Tan, Kwan Wee; Moore, David T; Saliba, Michael; Sai, Hiroaki; Estroff, Lara A; Hanrath, Tobias; Snaith, Henry J; Wiesner, Ulrich

    2014-01-01

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI(3-x)Cl(x)) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI(3-x)Cl(x) material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance.

  3. Thermally Induced Structural Evolution and Performance of Mesoporous Block Copolymer-Directed Alumina Perovskite Solar Cells

    2015-01-01

    Structure control in solution-processed hybrid perovskites is crucial to design and fabricate highly efficient solar cells. Here, we utilize in situ grazing incidence wide-angle X-ray scattering and scanning electron microscopy to investigate the structural evolution and film morphologies of methylammonium lead tri-iodide/chloride (CH3NH3PbI3–xClx) in mesoporous block copolymer derived alumina superstructures during thermal annealing. We show the CH3NH3PbI3–xClx material evolution to be characterized by three distinct structures: a crystalline precursor structure not described previously, a 3D perovskite structure, and a mixture of compounds resulting from degradation. Finally, we demonstrate how understanding the processing parameters provides the foundation needed for optimal perovskite film morphology and coverage, leading to enhanced block copolymer-directed perovskite solar cell performance. PMID:24684494

  4. Perturbed cholesterol and vesicular trafficking associated with dengue blocking in Wolbachia-infected Aedes aegypti cells.

    Geoghegan, Vincent; Stainton, Kirsty; Rainey, Stephanie M; Ant, Thomas H; Dowle, Adam A; Larson, Tony; Hester, Svenja; Charles, Philip D; Thomas, Benjamin; Sinkins, Steven P

    2017-09-13

    Wolbachia are intracellular maternally inherited bacteria that can spread through insect populations and block virus transmission by mosquitoes, providing an important approach to dengue control. To better understand the mechanisms of virus inhibition, we here perform proteomic quantification of the effects of Wolbachia in Aedes aegypti mosquito cells and midgut. Perturbations are observed in vesicular trafficking, lipid metabolism and in the endoplasmic reticulum that could impact viral entry and replication. Wolbachia-infected cells display a differential cholesterol profile, including elevated levels of esterified cholesterol, that is consistent with perturbed intracellular cholesterol trafficking. Cyclodextrins have been shown to reverse lipid accumulation defects in cells with disrupted cholesterol homeostasis. Treatment of Wolbachia-infected Ae. aegypti cells with 2-hydroxypropyl-β-cyclodextrin restores dengue replication in Wolbachia-carrying cells, suggesting dengue is inhibited in Wolbachia-infected cells by localised cholesterol accumulation. These results demonstrate parallels between the cellular Wolbachia viral inhibition phenotype and lipid storage genetic disorders. Wolbachia infection of mosquitoes can block dengue virus infection and is tested in field trials, but the mechanism of action is unclear. Using proteomics, Geoghegan et al. here identify effects of Wolbachia on cholesterol homeostasis and dengue virus replication in Aedes aegypti.

  5. Dismantling of a hot cell-block and the treatment of the produced concrete bars

    Rompf, U.; Brielmayer, M.; Graf, A.; Stutz, U.; Ambos, F.

    2003-01-01

    A building with hot cells had been operated in Karlstein/Main from 1968 to 1989 in order to perform check-ups at radiated fuel rods and nuclear components. The operation of the system was stopped after an operation period of approximately 20 years. The core part of the building to be disassembled is a U-shaped hot cell-block with nine individual cells, partly consisting of heavy reinforced concrete, located in the ground floor (fig. 1 and fig. 2). The major part of the cells was covered with 10 mm steel plate and provided with approx. 1,400 openings of all different kinds. The wall thickness of the cells was between 0.90 m and 1.10 m. Under these conditions a successful decontamination at the ''existing building structure'' was not possible. Therefore, the non-supporting structures of the hot cell-block were removed in individual blocks by means of sawing and the remaining walls and floors were peeled by using the diamond rope sawing technique. The dismantling took 17 months. A re-treatment of the produced concrete blocks (235 blocks, approx. 970 Mg) to reduce the radioactive waste to a minimum was performed at the Research Centre Karlsruhe, Central Decontamination Department (HDB). The Target of the concrete bar treatment at HDB is to reduce the volume of radioactive waste to a minimum and to add the major part of the concrete bars to harmless utilisation. To achieve the same, initially the more contaminated parts of the bars without openings, such as tubes, cable or ventilating shafts, are removed by means of wire cutting and packed into a KONRAD-Container as radioactive waste. The remaining bar is decontaminated by means of sandblasting and afterwards, following successful release measurement, released from the scope of the regulations under the Atomic Energy. Bars with openings are crushed into small pieces by means of the remote-controlled chisel excavator, in order to separate the individual kinds of material. The rubble is packed into drums and measured by

  6. Radiation block of bone marrow cell mitoses and the effect of insulin

    Barkalaya, A I

    1976-01-01

    Insulin (0.15 - 0.2 units/kg) has been administered to white rats immediately after the exposure to 750 R, at the background of hypercorticoidism. This resulted in the inhibition of the development of the post-irradiation-stress-hyperglycemia; and the mitotic index of the bone marrow cells at the time of the mitosis block was higher than in the control irradiated rats. Insulin administration at the peak of radiation sickness during hypercorticoidism levelled hyperglycemia, stimulated the mitotic activity of cells of the bone marrow and the regeneration of the latter.

  7. G2-block after irradiation of cells with different p53 status

    Zoelzer, Friedo [University of South Bohemia in Ceske Budejovice, Department of Radiology, Toxicology and Civil Protection, Faculty of Health and Social Studies, Ceske Budejovice (Czech Republic); University Duisburg-Essen, Institute of Medical Radiobiology, Medical Faculty, Essen (Germany); Jagetia, Ganesh [University Duisburg-Essen, Institute of Medical Radiobiology, Medical Faculty, Essen (Germany); Mizoram University, Department of Zoology, School of Life Sciences, Aizawl (India); Streffer, Christian [University Duisburg-Essen, Institute of Medical Radiobiology, Medical Faculty, Essen (Germany)

    2014-11-15

    Although it is clear that functional p53 is not required for radiation-induced G{sub 2} block, certain experimental findings suggest a role for p53 in this context. For instance, as we also confirm here, the maximum accumulation in the G{sub 2} compartment after X-ray exposure occurs much later in p53 mutants than in wild types. It remains to be seen, however, whether this difference is due to a longer block in the G{sub 2} phase itself. We observed the movement of BrdU-labeled cells through G{sub 2} and M into G{sub 1}. From an analysis of the fraction of labeled cells that entered the second posttreatment cell cycle, we were able to determine the absolute duration of the G{sub 2} and M phases in unirradiated and irradiated cells. Our experiments with four cell lines, two melanomas and two squamous carcinomas, showed that the radiation-induced delay of transition through the G{sub 2} and M phases did not correlate with p53 status. We conclude that looking at the accumulation of cells in the G{sub 2} compartment alone is misleading when differences in the G{sub 2} block are investigated and that the G{sub 2} block itself is indeed independent of functional p53. (orig.) [German] Obwohl klar ist, dass ein funktionelles p53-Protein fuer die Ausbildung des strahleninduzierten G{sub 2}-Blocks nicht zwingend erforderlich ist, gibt es experimentelle Befunde, die nahe legen, dass p53 in diesem Zusammenhang doch eine gewisse Rolle spielt. Zum Beispiel bestaetigen wir hier fruehere Berichte, dass die Akkumulation von Zellen im G{sub 2}-Kompartiment bei p53-Mutanten deutlich spaeter nach Bestrahlung ihr Maximum erreicht als bei p53-Wildtypen. Es bleibt jedoch zu klaeren, ob dieser Unterschied seinen Grund in einem laengeren Block der G{sub 2}-Phase selbst hat. Beobachtet wurde die Bewegung von BrdU-markierten Zellen durch G{sub 2} und M nach G{sub 1}. Aus der zeitlichen Veraenderung des Anteils markierter Zellen im G{sub 1}-Kompartiment des naechsten Zellzyklus konnte die

  8. The contribution of cell blocks in the diagnosis of mediastinal masses and hilar adenopathy samples from echobronchoscopy.

    Lourido-Cebreiro, Tamara; Leiro-Fernández, Virginia; Tardio-Baiges, Antoni; Botana-Rial, Maribel; Núñez-Delgado, Manuel; Álvarez-Martín, M Jesús; Fernández-Villar, Alberto

    2014-07-01

    Cell block material from puncture can be obtained with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in many cases. The aim of this study was to analyse the value of additional information from cell blocks obtained with EBUS-TBNA samples from mediastinal and hilar lymph nodes and masses. Review of pathology reports with a specific diagnosis obtained from EBUS-TBNA samples of mediastinal or hilar lesions, prospectively obtained over a two-year period. The generation of cell blocks from cytology needle samples, the contribution to morphological diagnosis, and the possible use of samples for immunohistochemistry were analysed. One hundred and twenty-nine samples corresponding to 110 patients were reviewed. The diagnosis was lung cancer in 81% of cases, extrapulmonary carcinoma in 10%, sarcoidosis in 4%, lymphoma in 2.7%, and tuberculosis in 0.9%. Cell blocks could be obtained in 72% of cases. Immunohistochemistry studies on the cell blocks were significantly easier to perform than on conventional smears (52.6% vs. 14%, P<.0001). In 4cases, the cell block provided an exclusive morphological diagnosis (3sarcoidosis and one metastasis from prostatic carcinoma) and in 3carcinomas, subtype and origin could be identified. Exclusive diagnoses from the cell block were significantly more frequent in benign disease than in malignant disease (25% vs 0.9%, P=.002). Cell blocks were obtained from 72% of EBUS-TBNA diagnostic procedures. The main contributions of cell blocks to pathology examinations were the possibility of carrying out immunohistochemical staining for the better classification of neoplasms, especially extrapulmonary metastatic tumours, and the improved diagnosis of benign lesions. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

  9. Diagnostic utility of the cell block method versus the conventional smear study in pleural fluid cytology.

    Shivakumarswamy, Udasimath; Arakeri, Surekha U; Karigowdar, Mahesh H; Yelikar, Br

    2012-01-01

    The cytological examinations of serous effusions have been well-accepted, and a positive diagnosis is often considered as a definitive diagnosis. It helps in staging, prognosis and management of the patients in malignancies and also gives information about various inflammatory and non-inflammatory lesions. Diagnostic problems arise in everyday practice to differentiate reactive atypical mesothelial cells and malignant cells by the routine conventional smear (CS) method. To compare the morphological features of the CS method with those of the cell block (CB) method and also to assess the utility and sensitivity of the CB method in the cytodiagnosis of pleural effusions. The study was conducted in the cytology section of the Department of Pathology. Sixty pleural fluid samples were subjected to diagnostic evaluation for over a period of 20 months. Along with the conventional smears, cell blocks were prepared by using 10% alcohol-formalin as a fixative agent. Statistical analysis with the 'z test' was performed to identify the cellularity, using the CS and CB methods. Mc. Naemer's χ(2)test was used to identify the additional yield for malignancy by the CB method. Cellularity and additional yield for malignancy was 15% more by the CB method. The CB method provides high cellularity, better architectural patterns, morphological features and an additional yield of malignant cells, and thereby, increases the sensitivity of the cytodiagnosis when compared with the CS method.

  10. Diagnostic utility of the cell block method versus the conventional smear study in pleural fluid cytology

    Udasimath Shivakumarswamy

    2012-01-01

    Full Text Available Background: The cytological examinations of serous effusions have been well-accepted, and a positive diagnosis is often considered as a definitive diagnosis. It helps in staging, prognosis and management of the patients in malignancies and also gives information about various inflammatory and non-inflammatory lesions. Diagnostic problems arise in everyday practice to differentiate reactive atypical mesothelial cells and malignant cells by the routine conventional smear (CS method. Aims: To compare the morphological features of the CS method with those of the cell block (CB method and also to assess the utility and sensitivity of the CB method in the cytodiagnosis of pleural effusions. Materials and Methods: The study was conducted in the cytology section of the Department of Pathology. Sixty pleural fluid samples were subjected to diagnostic evaluation for over a period of 20 months. Along with the conventional smears, cell blocks were prepared by using 10% alcohol-formalin as a fixative agent. Statistical analysis with the ′z test′ was performed to identify the cellularity, using the CS and CB methods. Mc. Naemer′s χ2 test was used to identify the additional yield for malignancy by the CB method. Results: Cellularity and additional yield for malignancy was 15% more by the CB method. Conclusions: The CB method provides high cellularity, better architectural patterns, morphological features and an additional yield of malignant cells, and thereby, increases the sensitivity of the cytodiagnosis when compared with the CS method.

  11. Contribution of ultrasound-guided fine-needle aspiration cell blocks of metastatic supraclavicular lymph nodes to the diagnosis of lung cancer

    Hai-Ying Tian

    2015-01-01

    Conclusion: Cell-block samples from US-guided FNA is a promising, relatively noninvasive technique to provide additional information in lung cancer diagnosis. Analysis of cell blocks allows for genetic analysis of the patients with supraclavicular lymph nodes metastasis.

  12. Block Copolymer Electrolytes: Thermodynamics, Ion Transport, and Use in Solid- State Lithium/Sulfur Cells

    Teran, Alexander Andrew

    anode, the compatibility of the sulfur cathode was explored. The sulfur cathode presents many unique challenges, including the generation of soluble lithium polysulfides (Li2Sx, 2 ≤ x ≤ 8) during discharge. The solubility of such species in block copolymers and their effect on morphology was examined. The lithium polysulfides were found to exhibit similar solubility in the block copolymers as in typical organic electrolytes, however induced unusual and unexpected phase behavior in the block copolymers. Inspired by successful efforts to physically confine the soluble lithium polysulfides via nanostructured carbon-sulfur composites in the cathode, our nanostructured block copolymer electrolytes were employed in full electrochemical cells with a lithium metal anode and sulfur cathode. Different cathode compositions, electrolyte additives, and cell architectures were tested. Surprisingly, the polysulfides diffused readily from the cathode through the block copolymer electrolyte, and the normally robust SEO|Li metal interface was detrimentally affected their presence during cycling. The polysulfides appeared to change the mechanical properties of the electrolyte such that intimate contact with the lithium metal was lost. Several promising strategies to overcome this problem were investigated and offer exciting avenues for improvement for future researchers. (Abstract shortened by UMI.).

  13. Retinal ganglion cells: mechanisms underlying depolarization block and differential responses to high frequency electrical stimulation of ON and OFF cells

    Kameneva, T.; Maturana, M. I.; Hadjinicolaou, A. E.; Cloherty, S. L.; Ibbotson, M. R.; Grayden, D. B.; Burkitt, A. N.; Meffin, H.

    2016-02-01

    Objective. ON and OFF retinal ganglion cells (RGCs) are known to have non-monotonic responses to increasing amplitudes of high frequency (2 kHz) biphasic electrical stimulation. That is, an increase in stimulation amplitude causes an increase in the cell’s spike rate up to a peak value above which further increases in stimulation amplitude cause the cell to decrease its activity. The peak response for ON and OFF cells occurs at different stimulation amplitudes, which allows differential stimulation of these functional cell types. In this study, we investigate the mechanisms underlying the non-monotonic responses of ON and OFF brisk-transient RGCs and the mechanisms underlying their differential responses. Approach. Using in vitro patch-clamp recordings from rat RGCs, together with simulations of single and multiple compartment Hodgkin-Huxley models, we show that the non-monotonic response to increasing amplitudes of stimulation is due to depolarization block, a change in the membrane potential that prevents the cell from generating action potentials. Main results. We show that the onset for depolarization block depends on the amplitude and frequency of stimulation and reveal the biophysical mechanisms that lead to depolarization block during high frequency stimulation. Our results indicate that differences in transmembrane potassium conductance lead to shifts of the stimulus currents that generate peak spike rates, suggesting that the differential responses of ON and OFF cells may be due to differences in the expression of this current type. We also show that the length of the axon’s high sodium channel band (SOCB) affects non-monotonic responses and the stimulation amplitude that leads to the peak spike rate, suggesting that the length of the SOCB is shorter in ON cells. Significance. This may have important implications for stimulation strategies in visual prostheses.

  14. Diagnostic Value of Processing Cytologic Aspirates of Renal Tumors in Agar Cell (Tissue) Blocks

    Smedts, F.; Schrik, M.; Horn, T.

    2010-01-01

    smears were prepared after each aspiration for conventional cytology and the remaining aspirate was processed for the improved agar microbiopsy (AM) method. Conventional cytology slides, AM slides and surgical specimens were diagnosed separately, after which the diagnoses were compared....... Immunohistochemistry was performed as required on the AM sections. Surgical specimens served as the gold standard. Results In 53% of conventional cytologic smears, the cellular yield was sufficient to render a correct diagnosis. In 12% the diagnosis was incorrect, in 21% only a differential diagnosis could be fin......-initiated, and in 14% too few diagnostic cells were present in the conventional smears for cytologic diagnosis. It was, however, possible to correctly diagnose histologic sections from 97% of AM tissue blocks. In 11 cases this was facilitated with immunochemistry. In only 1 case did the AM tissue block contain too few...

  15. Omeprazole blocks STAT6 binding to the eotaxin-3 promoter in eosinophilic esophagitis cells.

    Xi Zhang

    Full Text Available Patients who have esophageal eosinophilia without gastroesophageal reflux disease (GERD nevertheless can respond to proton pump inhibitors (PPIs, which can have anti-inflammatory actions independent of effects on gastric acid secretion. In esophageal cell cultures, omeprazole has been reported to inhibit Th2 cytokine-stimulated expression of eotaxin-3, an eosinophil chemoattractant contributing to esophageal eosinophilia in eosinophilic esophagitis (EoE. The objective of this study was to elucidate molecular mechanisms underlying PPI inhibition of IL-4-stimulated eotaxin-3 production by esophageal cells.Telomerase-immortalized and primary cultures of esophageal squamous cells from EoE patients were treated with IL-4 in the presence or absence of acid-activated omeprazole or lansoprazole. We measured eotaxin-3 protein secretion by ELISA, mRNA expression by PCR, STAT6 phosphorylation and nuclear translocation by Western blotting, eotaxin-3 promoter activation by an exogenous reporter construct, and STAT6, RNA polymerase II, and trimethylated H3K4 binding to the endogenous eotaxin-3 promoter by ChIP assay. Omeprazole in concentrations ≥5 µM significantly decreased IL-4-stimulated eotaxin-3 protein secretion and mRNA expression. Lansoprazole also blocked eotaxin-3 protein secretion. Omeprazole had no effect on eotaxin-3 mRNA stability or on STAT6 phosphorylation and STAT6 nuclear translocation. Rather, omeprazole blocked binding of IL-4-stimulated STAT6, RNA polymerase II, and trimethylated H3K4 to the eotaxin-3 promoter.PPIs, in concentrations achieved in blood with conventional dosing, significantly inhibit IL-4-stimulated eotaxin-3 expression in EoE esophageal cells and block STAT6 binding to the promoter. These findings elucidate molecular mechanisms whereby patients with Th2 cytokine-driven esophageal eosinophilia can respond to PPIs, independent of effects on gastric acid secretion.

  16. CYTOKINESIS-BLOCK MICRONUCLEUS ASSAY IN HUMAN GLIOMA CELLS EXPOSED TO RADIATION

    Jerzy Slowinski

    2011-05-01

    Full Text Available Biological tests are efficient in reflecting the biological influences of several types of generally harmful exposures. The micronucleus assay is widely used in genotoxicity studies or studies on genomic damage in general. We present methodological aspects of cytokinesis-block micronucleus assay performed in human gliomas irradiated in vitro. Eight human glioblastoma cell lines obtained from DSMZ (Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Germany were gamma-irradiated (60Co over a dose range of 0-10 Gy. Cytokinesis-block micronucleus assay was performed to quantitate cytogenetic damage. The cells were fixed directly on dishes, stained with fluorochrome DAPI and evaluated under fluorescent and phase contrast microscope. The micronucleus frequency was expressed as a micronuclei (MN per binucleated cell (BNC ratio, calculated after scoring at least 100 BNC per dish. The frequency of spontaneous MN ranged from 0.17 to 0.613 (mean: 0.29 ± 0.14. After irradiation increase of MN frequency in the range of 0.312 - 2.241 (mean: 0.98 ± 0.68 was found at 10 Gy. Gliomas are extremely heterogenous in regard to cytogenetic effects of irradiation, as shown in this study by cytokinesis-block micronucleus assay. This test is easily performed on irradiated glioma cell lines and can assist in determining their radiosensitivity. However, in order to obtain reliable and reproducible results, precise criteria for MN scoring must be strictly followed. Simultaneous use of fluorescent and phase contrast equipment improves imaging of morphological details and can further optimize MN scoring.

  17. Candidate Microbicides Block HIV-1 Infection of Human Immature Langerhans Cells within Epithelial Tissue Explants

    Kawamura, Tatsuyoshi; Cohen, Sandra S.; Borris, Debra L.; Aquilino, Elisabeth A.; Glushakova, Svetlana; Margolis, Leonid B.; Orenstein, Jan M.; Offord, Robin E.; Neurath, A. Robert; Blauvelt, Andrew

    2000-01-01

    Initial biologic events that underlie sexual transmission of HIV-1 are poorly understood. To model these events, we exposed human immature Langerhans cells (LCs) within epithelial tissue explants to two primary and two laboratory-adapted HIV-1 isolates. We detected HIV-1Ba-L infection in single LCs that spontaneously emigrated from explants by flow cytometry (median of infected LCs = 0.52%, range = 0.08–4.77%). HIV-1–infected LCs downregulated surface CD4 and CD83, whereas MHC class II, CD80, and CD86 were unchanged. For all HIV-1 strains tested, emigrated LCs were critical in establishing high levels of infection (0.1–1 μg HIV-1 p24 per milliliter) in cocultured autologous or allogeneic T cells. HIV-1Ba-L (an R5 HIV-1 strain) more efficiently infected LC–T cell cocultures when compared with HIV-1IIIB (an X4 HIV-1 strain). Interestingly, pretreatment of explants with either aminooxypentane-RANTES (regulated upon activation, normal T cell expressed and secreted) or cellulose acetate phthalate (potential microbicides) blocked HIV-1 infection of LCs and subsequent T cell infection in a dose-dependent manner. In summary, we document HIV-1 infection in single LCs after exposure to virus within epithelial tissue, demonstrate that relatively low numbers of these cells are capable of inducing high levels of infection in cocultured T cells, and provide a useful explant model for testing of agents designed to block sexual transmission of HIV-1. PMID:11085750

  18. Blocking the recruitment of naive CD4+ T cells reverses immunosuppression in breast cancer

    Shicheng Su; Ling Lin; Yunjie Zeng; Nengtai Ouyang; Xiuying Cui; Herui Yao; Fengxi Su; Jian-dong Huang; Judy Lieberman; Qiang Liu; Erwei Song; Jianyou Liao; Jiang Liu; Di Huang; Chonghua He; Fei Chen; LinBing Yang; Wei Wu; Jianing Chen

    2017-01-01

    The origin of tumor-infiltrating Tregs,critical mediators of tumor immunosuppression,is unclear.Here,we show that tumor-infiltrating naive CD4+ T cells and Tregs in human breast cancer have overlapping TCR repertoires,while hardly overlap with circulating Tregs,suggesting that intratumoral Tregs mainly develop from naive T cells in situ rather than from recruited Tregs.Furthermore,the abundance of naive CD4+ T cells and Tregs is closely correlated,both indicating poor prognosis for breast cancer patients.Naive CD4+ T cells adhere to tumor slices in proportion to the abundance of CCLl8-producing macrophages.Moreover,adoptively transferred human naive CD4+ T cells infiltrate human breast cancer orthotopic xenografts in a CCL18-dependent manner.In human breast cancer xenografts in humanized mice,blocking the recruitment of naive CD4+ T cells into tumor by knocking down the expression of PITPNM3,a CCL18 receptor,significantly reduces intratumoral Tregs and inhibits tumor progression.These findings suggest that breast tumor-infiltrating Tregs arise from chemotaxis of circulating naive CD4+ T cells that differentiate into Tregs in situ.Inhibiting naive CD4+ T cell recruitment into tumors by interfering with PITPNM3 recognition of CCL18 may be an attractive strategy for anticancer immunotherapy.

  19. Blocking the recruitment of naive CD4+ T cells reverses immunosuppression in breast cancer

    Su, Shicheng; Liao, Jianyou; Liu, Jiang; Huang, Di; He, Chonghua; Chen, Fei; Yang, LinBing; Wu, Wei; Chen, Jianing; Lin, Ling; Zeng, Yunjie; Ouyang, Nengtai; Cui, Xiuying; Yao, Herui; Su, Fengxi; Huang, Jian-dong; Lieberman, Judy; Liu, Qiang; Song, Erwei

    2017-01-01

    The origin of tumor-infiltrating Tregs, critical mediators of tumor immunosuppression, is unclear. Here, we show that tumor-infiltrating naive CD4+ T cells and Tregs in human breast cancer have overlapping TCR repertoires, while hardly overlap with circulating Tregs, suggesting that intratumoral Tregs mainly develop from naive T cells in situ rather than from recruited Tregs. Furthermore, the abundance of naive CD4+ T cells and Tregs is closely correlated, both indicating poor prognosis for breast cancer patients. Naive CD4+ T cells adhere to tumor slices in proportion to the abundance of CCL18-producing macrophages. Moreover, adoptively transferred human naive CD4+ T cells infiltrate human breast cancer orthotopic xenografts in a CCL18-dependent manner. In human breast cancer xenografts in humanized mice, blocking the recruitment of naive CD4+ T cells into tumor by knocking down the expression of PITPNM3, a CCL18 receptor, significantly reduces intratumoral Tregs and inhibits tumor progression. These findings suggest that breast tumor-infiltrating Tregs arise from chemotaxis of circulating naive CD4+ T cells that differentiate into Tregs in situ. Inhibiting naive CD4+ T cell recruitment into tumors by interfering with PITPNM3 recognition of CCL18 may be an attractive strategy for anticancer immunotherapy. PMID:28290464

  20. Block to influenza virus replication in cells preirradiated with ultraviolet light

    Mahy, B.W.J.; Carroll, A.R.; Brownson, J.M.T.; McGeoch, D.J.

    1977-01-01

    Ultraviolet (uv) irradiation of CEF cells immediately before infection with influenza A (fowl plague) virus inhibited virus growth; no inhibition of the growth of a parainfluenza virus (Newcastle disease virus) could be detected in irradiated cells. The kinetics of inhibition after various doses of uv irradiation were multihit, with an extrapolation number of two. When irradiated cells were allowed to photoreactivate by exposure to visible light for 16 hr their capacity to support influenza virus replication was largely restored; this process was sensitive to caffeine, suggesting that it required DNA repair. In CEF cells exposed to 360 ergs/mm 2 of uv radiation the rate of synthesis of host cellular RNA was reduced by more than 90%, and that of host cellular protein by 40 to 50%, as judged by incorporation of precursor molecules into an acid-insoluble form. When such irradiated cells were infected with influenza virus all the genome RNA segments were transcribed, but the overall concentration of virus-specific poly(A)-containing cRNA was reduced about 50-fold. Within this population of cRNA molecules, the RNAs coding for late proteins (HA, NA, and M) were reduced in amount relative to the other segments. The rates of synthesis of the M and HA proteins were specifically reduced in uv-irradiated cells, but the rates of synthesis of the P, NP, and NS proteins were only slightly reduced compared to normal cells. Immunofluorescent studies showed that, in uv-irradiated cells, NP migrated into the nucleus early after infection and later migrated out into the cytoplasm, as in normal cells. In contrast to normal cells, no specific immunofluorescence associated with M protein could be observed in uv-irradiated cells. It is concluded that uv-induced damage to host cellular DNA alters the pattern of RNA transcription in CEF cells infected with influenza virus, and that this results in a block to late protein synthesis which stops virus production

  1. Inhibition of radiation induced migration of human head and neck squamous cell carcinoma cells by blocking of EGF receptor pathways

    Pickhard, Anja C; Schlegel, Jürgen; Arnold, Wolfgang; Reiter, Rudolf; Margraf, Johanna; Knopf, Andreas; Stark, Thomas; Piontek, Guido; Beck, Carolin; Boulesteix, Anne-Laure; Scherer, Elias Q; Pigorsch, Steffi

    2011-01-01

    Recently it has been shown that radiation induces migration of glioma cells and facilitates a further spread of tumor cells locally and systemically. The aim of this study was to evaluate whether radiotherapy induces migration in head and neck squamous cell carcinoma (HNSCC). A further aim was to investigate the effects of blocking the epidermal growth factor receptor (EGFR) and its downstream pathways (Raf/MEK/ERK, PI3K/Akt) on tumor cell migration in vitro. Migration of tumor cells was assessed via a wound healing assay and proliferation by a MTT colorimeritric assay using 3 HNSCC cell lines (BHY, CAL-27, HN). The cells were treated with increasing doses of irradiation (2 Gy, 5 Gy, 8 Gy) in the presence or absence of EGF, EGFR-antagonist (AG1478) or inhibitors of the downstream pathways PI3K (LY294002), mTOR (rapamycin) and MEK1 (PD98059). Biochemical activation of EGFR and the downstream markers Akt and ERK were examined by Western blot analysis. In absence of stimulation or inhibition, increasing doses of irradiation induced a dose-dependent enhancement of migrating cells (p < 0.05 for the 3 HNSCC cell lines) and a decrease of cell proliferation (p < 0.05 for the 3 HNSCC cell lines). The inhibition of EGFR or the downstream pathways reduced cell migration significantly (almost all p < 0.05 for the 3 HNSCC cell lines). Stimulation of HNSCC cells with EGF caused a significant increase in migration (p < 0.05 for the 3 HNSCC cell lines). After irradiation alone a pronounced activation of EGFR was observed by Western blot analysis. Our results demonstrate that the EGFR is involved in radiation induced migration of HNSCC cells. Therefore EGFR or the downstream pathways might be a target for the treatment of HNSCC to improve the efficacy of radiotherapy

  2. 324 and 325 Building Hot Cell Cleanout Program: Air lock cover block refurbishment

    Katayama, Y.B.; Holton, L.K. Jr.; Gale, R.M.

    1989-05-01

    The high-density concrete cover blocks shielding the pipe trench in the hot-cell air lock of the 324 Building Radiochemical Engineering Cells had accumulated fixed radioactivity ranging from 1100 to 22, 000 mrad/hr. A corresponding increase in the radiation exposure to personnel entering the air lock, together with ALARA concerns, led to the removal of the contaminated concrete surface with a hydraulic spaller and the emplacement of a stainless steel covering over a layer of grout. The resultant saving in radiation exposure is estimated to be 7200 mrad for personnel completing burial box runs for the 324 and 325 Building Hot Cell Cleanout Program. Radiation exposure to all staff members entering the air lock is now at least 50% lower. 3 refs., 22 figs., 1 tab

  3. Block copolymer directed synthesis of mesoporous TiO 2 for dye-sensitized solar cells

    Nedelcu, Mihaela

    2009-01-01

    The morphology of TiO2 plays an important role in the operation of solid-state dye-sensitized solar cells. By using polyisoprene-block- ethyleneoxide (PI-b-PEO) copolymers as structure directing agents for a sol-gel based synthesis of mesoporous TiO2, we demonstrate a strategy for the detailed control of the semiconductor morphology on the 10 nm length scale. The careful adjustment of polymer molecular weight and titania precursor content is used to systematically vary the material structure and its influence upon solar cell performance is investigated. Furthermore, the use of a partially sp 2 hybridized structure directing polymer enables the crystallization of porous TiO2 networks at high temperatures without pore collapse, improving its performance in solid-state dye-sensitized solar cells. © 2009 The Royal Society of Chemistry.

  4. Lysophosphatidic acid directly induces macrophage-derived foam cell formation by blocking the expression of SRBI.

    Chen, Linmu; Zhang, Jun; Deng, Xiao; Liu, Yan; Yang, Xi; Wu, Qiong; Yu, Chao

    2017-09-23

    The leading cause of morbidity and mortality is the result of cardiovascular disease, mainly atherosclerosis. The formation of macrophage foam cells by ingesting ox-LDL and focal retention in the subendothelial space are the hallmarks of the early atherosclerotic lesion. Lysophosphatidic acid (LPA), which is a low-molecular weight lysophospholipid enriched in oxidized LDL, exerts a range of effects on the cardiovascular system. Previous reports show that LPA increases the uptake of ox-LDL to promote the formation of foam cells. However, as the most active component of ox-LDL, there is no report showing whether LPA directly affects foam cell formation. The aim of this study was to investigate the effects of LPA on foam cell formation, as well as to elucidate the underlying mechanism. Oil red O staining and a Cholesterol/cholesteryl ester quantitation assay were used to evaluate foam cell formation in Raw264.7 macrophage cells. We utilized a Western blot and RT-PCR to investigate the relationship between LPA receptors and lipid transport related proteins. We found that LPA promoted foam cell formation, using 200 μM for 24 h. Meanwhile, the expression of the Scavenger receptor BI (SRBI), which promotes the efflux of free cholesterol, was decreased. Furthermore, the LPA 1/3 receptor antagonist Ki16425 significantly abolished the LPA effects, indicating that LPA 1/3 was involved in the foam cell formation and SRBI expression induced by LPA. Additionally, the LPA-induced foam cell formation was blocked with an AKT inhibitor. Our results suggest that LPA-enhanced foam cell formation is mediated by LPA 1/3 -AKT activation and subsequent SRBI expression. Copyright © 2017. Published by Elsevier Inc.

  5. Blocking type I interferon signaling enhances T cell recovery and reduces HIV-1 reservoirs.

    Cheng, Liang; Ma, Jianping; Li, Jingyun; Li, Dan; Li, Guangming; Li, Feng; Zhang, Qing; Yu, Haisheng; Yasui, Fumihiko; Ye, Chaobaihui; Tsao, Li-Chung; Hu, Zhiyuan; Su, Lishan; Zhang, Liguo

    2017-01-03

    Despite the efficient suppression of HIV-1 replication that can be achieved with combined antiretroviral therapy (cART), low levels of type I interferon (IFN-I) signaling persist in some individuals. This sustained signaling may impede immune recovery and foster viral persistence. Here we report studies using a monoclonal antibody to block IFN-α/β receptor (IFNAR) signaling in humanized mice (hu-mice) that were persistently infected with HIV-1. We discovered that effective cART restored the number of human immune cells in HIV-1-infected hu-mice but did not rescue their immune hyperactivation and dysfunction. IFNAR blockade fully reversed HIV-1-induced immune hyperactivation and rescued anti-HIV-1 immune responses in T cells from HIV-1-infected hu-mice. Finally, we found that IFNAR blockade in the presence of cART reduced the size of HIV-1 reservoirs in lymphoid tissues and delayed HIV-1 rebound after cART cessation in the HIV-1-infected hu-mice. We conclude that low levels of IFN-I signaling contribute to HIV-1-associated immune dysfunction and foster HIV-1 persistence in cART-treated hosts. Our results suggest that blocking IFNAR may provide a potential strategy to enhance immune recovery and reduce HIV-1 reservoirs in individuals with sustained elevations in IFN-I signaling during suppressive cART.

  6. Blocking CD147 induces cell death in cancer cells through impairment of glycolytic energy metabolism

    Baba, Miyako; Inoue, Masahiro; Itoh, Kazuyuki; Nishizawa, Yasuko

    2008-01-01

    CD147 is a multifunctional transmembrane protein and promotes cancer progression. We found that the anti-human CD147 mouse monoclonal antibody MEM-M6/1 strongly induces necrosis-like cell death in LoVo, HT-29, WiDr, and SW620 colon cancer cells and A2058 melanoma cells, but not in WI-38 and TIG-113 normal fibroblasts. Silencing or overexpression of CD147 in LoVo cells enhanced or decreased the MEM-M6/1 induced cell death, respectively. CD147 is known to form complex with proton-linked monocarboxylate transporters (MCTs), which is critical for lactate transport and intracellular pH (pHi) homeostasis. In LoVo cells, CD147 and MCT-1 co-localized on the cell surface, and MEM-M6/1 inhibited the association of these molecules. MEM-M6/1 inhibited lactate uptake, lactate release, and reduced pHi. Further, the induction of acidification was parallel to the decrease of the glycolytic flux and intracellular ATP levels. These effects were not found in the normal fibroblasts. As cancer cells depend on glycolysis for their energy production, CD147 inhibition might induce cell death specific to cancer cells

  7. Poly[(3-hexylthiophene-block-(3-semifluoroalkylthiophene] for Polymer Solar Cells

    Takeshi Toru

    2010-12-01

    Full Text Available We report the synthesis of poly[(3-hexylthiophene-block-(3-(4,4,5,5,6,6,7,7,7-nonafluoroheptylthiophene], P(3HT-b-3SFT, carried out by the Grignard Metathesis Method (GRIM. The copolymers composition was determined by 1H and 19F NMR spectroscopies, and gel permeation chromatography (GPC. The thin films of P(3HT‑b‑3SFT were investigated by ultraviolet-visible absorption spectroscopy and atomic force microscopy (AFM. We also fabricated bulk-hetero junction (BHJ solar cells based on blends of P(3HT-b-3SFT and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM. Although the composition ratio of P3SFT in P(3HT-b-3SFT was low, the influence of P3SFT on the morphology and properties of solar cells was significant. The annealing process for the BHJ solar cells induced the formation of large domains and led to poor solar cell performance. The BHJ solar cells, based on PCBM and P(3HT-b-3SFT, prepared by the non-annealing process, had a maximum power conversion efficiency of 0.84% under 100 mW/cm2 (AM 1.5 solar illumination in air.

  8. A Short-Term Exposure to Tributyltin Blocks Leydig Cell Regeneration in the Adult Rat Testis

    Xiaolong Wu

    2017-10-01

    Full Text Available Background: Tributyltin (TBT is widely used as an antifouling agent that may cause reproductive toxicity. The mechanism of TBT on Leydig cell development is still unknown. The objective of the present study was to investigate whether a brief exposure to low doses of TBT permanently affects Leydig cell development and to clarify the underlying mechanism.Methods: Adult male Sprague Dawley rats were randomly assigned into four groups and gavaged normal saline (control, 0.1, 1.0, or 10.0 mg/kg/day TBT for a consecutive 10 days, respectively. At the end of TBT treatment, all rats received a single intraperitoneal injection of 75 mg/kg ethane dimethane sulfonate (EDS to eliminate all of adult Leydig cells. Leydig cells began a developmental regeneration process on post-EDS day 35. The Leydig cell regeneration was evaluated by measuring serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels on post-EDS day 7, 35, and 56, the expression levels of Leydig cell genes, Leydig cell morphology and number and proliferation on post-EDS day 56.Results: TBT significantly reduced serum testosterone levels on post-EDS day 35 and 56 and increased serum luteinizing hormone and follicle-stimulating hormone levels on post-EDS day 56 at ≥1 mg/kg/day. Immunohistochemical staining showed that there were fewer regenerated Leydig cells in the TBT-treated testis on post-EDS day 56. Further study demonstrated that the mRNA or protein levels of Leydig (Lhcgr, Cyp11a1, Hsd3b1, Cyp17a1, and Hsd17b3 and Sertoli cells (Fshr, Dhh, and Sox9 were significantly down-regulated in the TBT-treated testes when compared to the control. Immunofluorescent staining showed that TBT inhibited Leydig cell proliferation as judged by the reduced number of proliferating cyclin nuclear antigen-positive Leydig cells on post-EDS day 35.Conclusion: The present study demonstrated that a short-term TBT exposure blocked Leydig cell developmental regeneration process via down

  9. A Short-Term Exposure to Tributyltin Blocks Leydig Cell Regeneration in the Adult Rat Testis.

    Wu, Xiaolong; Liu, Jianpeng; Duan, Yue; Gao, Shiyu; Lü, Yao; Li, Xiaoheng; Zhu, Qiqi; Chen, Xianwu; Lin, Jing; Ye, Leping; Ge, Ren-Shan

    2017-01-01

    Background: Tributyltin (TBT) is widely used as an antifouling agent that may cause reproductive toxicity. The mechanism of TBT on Leydig cell development is still unknown. The objective of the present study was to investigate whether a brief exposure to low doses of TBT permanently affects Leydig cell development and to clarify the underlying mechanism. Methods: Adult male Sprague Dawley rats were randomly assigned into four groups and gavaged normal saline (control), 0.1, 1.0, or 10.0 mg/kg/day TBT for a consecutive 10 days, respectively. At the end of TBT treatment, all rats received a single intraperitoneal injection of 75 mg/kg ethane dimethane sulfonate (EDS) to eliminate all of adult Leydig cells. Leydig cells began a developmental regeneration process on post-EDS day 35. The Leydig cell regeneration was evaluated by measuring serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels on post-EDS day 7, 35, and 56, the expression levels of Leydig cell genes, Leydig cell morphology and number and proliferation on post-EDS day 56. Results: TBT significantly reduced serum testosterone levels on post-EDS day 35 and 56 and increased serum luteinizing hormone and follicle-stimulating hormone levels on post-EDS day 56 at ≥1 mg/kg/day. Immunohistochemical staining showed that there were fewer regenerated Leydig cells in the TBT-treated testis on post-EDS day 56. Further study demonstrated that the mRNA or protein levels of Leydig ( Lhcgr , Cyp11a1, Hsd3b1, Cyp17a1 , and Hsd17b3 ) and Sertoli cells ( Fshr , Dhh , and Sox9 ) were significantly down-regulated in the TBT-treated testes when compared to the control. Immunofluorescent staining showed that TBT inhibited Leydig cell proliferation as judged by the reduced number of proliferating cyclin nuclear antigen-positive Leydig cells on post-EDS day 35. Conclusion: The present study demonstrated that a short-term TBT exposure blocked Leydig cell developmental regeneration process via down

  10. Block copolymer based composition and morphology control in nanostructured hybrid materials for energy conversion and storage: solar cells, batteries, and fuel cells

    Orilall, M. Christopher; Wiesner, Ulrich

    2011-01-01

    to materials design and current limitations, the review will highlight some of the most recent examples of block copolymer structure-directed nanomaterials for photovoltaics, batteries and fuel cells. In each case insights are provided into the various

  11. ING1 and 5-azacytidine act synergistically to block breast cancer cell growth.

    Satbir Thakur

    Full Text Available Inhibitor of Growth (ING proteins are epigenetic "readers" that recognize trimethylated lysine 4 of histone H3 (H3K4Me3 and target histone acetyl transferase (HAT and histone deacetylase (HDAC complexes to chromatin.Here we asked whether dysregulating two epigenetic pathways with chemical inhibitors showed synergistic effects on breast cancer cell line killing. We also tested whether ING1 could synergize better with chemotherapeutics that target the same epigenetic mechanism such as the HDAC inhibitor LBH589 (Panobinostat or a different epigenetic mechanism such as 5-azacytidine (5azaC, which inhibits DNA methyl transferases. Simultaneous treatment of breast cancer cell lines with LBH589 and 5azaC did not show significant synergy in killing cells. However, combination treatment of ING1 with either LBH589 or 5azaC did show synergy. The combination of ING1b with 5azaC, which targets two distinct epigenetic mechanisms, was more effective at lower doses and enhanced apoptosis as determined by Annexin V staining and cleavage of caspase 3 and poly-ADP-ribose polymerase (PARP. ING1b plus 5azaC also acted synergistically to increase γH2AX staining indicating significant levels of DNA damage were induced. Adenoviral delivery of ING1b with 5azaC also inhibited cancer cell growth in a murine xenograft model and led to tumor regression when viral concentration was optimized in vivo.These data show that targeting distinct epigenetic pathways can be more effective in blocking cancer cell line growth than targeting the same pathway with multiple agents, and that using viral delivery of epigenetic regulators can be more effective in synergizing with a chemical agent than using two chemotherapeutic agents. This study also indicates that the ING1 epigenetic regulator may have additional activities in the cell when expressed at high levels.

  12. Inhibition of apoptosis blocks human motor neuron cell death in a stem cell model of spinal muscular atrophy.

    Dhruv Sareen

    Full Text Available Spinal muscular atrophy (SMA is a genetic disorder caused by a deletion of the survival motor neuron 1 gene leading to motor neuron loss, muscle atrophy, paralysis, and death. We show here that induced pluripotent stem cell (iPSC lines generated from two Type I SMA subjects-one produced with lentiviral constructs and the second using a virus-free plasmid-based approach-recapitulate the disease phenotype and generate significantly fewer motor neurons at later developmental time periods in culture compared to two separate control subject iPSC lines. During motor neuron development, both SMA lines showed an increase in Fas ligand-mediated apoptosis and increased caspase-8 and-3 activation. Importantly, this could be mitigated by addition of either a Fas blocking antibody or a caspase-3 inhibitor. Together, these data further validate this human stem cell model of SMA, suggesting that specific inhibitors of apoptotic pathways may be beneficial for patients.

  13. IL-4 production by group 2 innate lymphoid cells promotes food allergy by blocking regulatory T-cell function.

    Noval Rivas, Magali; Burton, Oliver T; Oettgen, Hans C; Chatila, Talal

    2016-09-01

    Food allergy is a major health issue, but its pathogenesis remains obscure. Group 2 innate lymphoid cells (ILC2s) promote allergic inflammation. However their role in food allergy is largely unknown. We sought to investigate the role of ILC2s in food allergy. Food allergy-prone mice with a gain-of-function mutation in the IL-4 receptor α chain (Il4raF709) were orally sensitized with food allergens, and the ILC2 compartment was analyzed. The requirement for ILC2s in food allergy was investigated by using Il4raF709, IL-33 receptor-deficient (Il1rl1(-/-)), IL-13-deficient (Il13(-/-)), and IL-4-deficient (Il4(-/-)) mice and by adoptive transfer of in vitro-expanded ILC2s. Direct effects of ILC2s on regulatory T (Treg) cells and mast cells were analyzed in coculture experiments. Treg cell control of ILC2s was assessed in vitro and in vivo. Il4raF709 mice with food allergy exhibit increased numbers of ILC2s. IL-4 secretion by ILC2s contributes to the allergic response by reducing allergen-specific Treg cell and activating mast cell counts. IL-33 receptor deficiency in Il4raF709 Il1rl1(-/-) mice protects against allergen sensitization and anaphylaxis while reducing ILC2 induction. Adoptive transfer of wild-type and Il13(-/-) but not Il4(-/-) ILC2s restored sensitization in Il4raF709 Il1rl1(-/-) mice. Treg cells suppress ILC2s in vitro and in vivo. IL-4 production by IL-33-stimulated ILC2s blocks the generation of allergen-specific Treg cells and favors food allergy. Strategies to block ILC2 activation or the IL-33/IL-33 receptor pathway can lead to innovative therapies in the treatment of food allergy. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Novel derivatives of aclacinomycin A block cancer cell migration through inhibition of farnesyl transferase.

    Magi, Shigeyuki; Shitara, Tetsuo; Takemoto, Yasushi; Sawada, Masato; Kitagawa, Mitsuhiro; Tashiro, Etsu; Takahashi, Yoshikazu; Imoto, Masaya

    2013-03-01

    In the course of screening for an inhibitor of farnesyl transferase (FTase), we identified two compounds, N-benzyl-aclacinomycin A (ACM) and N-allyl-ACM, which are new derivatives of ACM. N-benzyl-ACM and N-allyl-ACM inhibited FTase activity with IC50 values of 0.86 and 2.93 μM, respectively. Not only ACM but also C-10 epimers of each ACM derivative failed to inhibit FTase. The inhibition of FTase by N-benzyl-ACM and N-allyl-ACM seems to be specific, because these two compounds did not inhibit geranylgeranyltransferase or geranylgeranyl pyrophosphate (GGPP) synthase up to 100 μM. In cultured A431 cells, N-benzyl-ACM and N-allyl-ACM also blocked both the membrane localization of H-Ras and activation of the H-Ras-dependent PI3K/Akt pathway. In addition, they inhibited epidermal growth factor (EGF)-induced migration of A431 cells. Thus, N-benzyl-ACM and N-allyl-ACM inhibited EGF-induced migration of A431 cells by inhibiting the farnesylation of H-Ras and subsequent H-Ras-dependent activation of the PI3K/Akt pathway.

  15. Conservation analysis of dengue virust-cell epitope-based vaccine candidates using peptide block entropy

    Olsen, Lars Rønn; Zhang, Guang Lan; Keskin, Derin B.

    2011-01-01

    residues. The block entropy analysis provides broad coverage of variant antigens. We applied the block entropy analysis method to the proteomes of the four serotypes of dengue virus (DENV) and found 1,551 blocks of 9-mer peptides, which cover 99% of available sequences with five or fewer unique peptides...

  16. Blocking of PDL-1 interaction enhances primary and secondary CD8 T cell response to herpes simplex virus-1 infection.

    Rudragouda Channappanavar

    Full Text Available The blocking of programmed death ligand-1 (PDL-1 has been shown to enhance virus-specific CD8 T cell function during chronic viral infections. Though, how PDL-1 blocking at the time of priming affects the quality of CD8 T cell response to acute infections is not well understood and remains controversial. This report demonstrates that the magnitude of the primary and secondary CD8 T cell responses to herpes simplex virus-1 (HSV-1 infection is subject to control by PDL-1. Our results showed that after footpad HSV-1 infection, PD-1 expression increases on immunodominant SSIEFARL peptide specific CD8 T cells. Additionally, post-infection, the level of PDL-1 expression also increases on CD11c+ dendritic cells. Intraperitoneal administration of anti-PDL-1 monoclonal antibody given one day prior to and three days after cutaneous HSV-1 infection, resulted in a marked increase in effector and memory CD8 T cell response to SSIEFARL peptide. This was shown by measuring the quantity and quality of SSIEFARL-specific CD8 T cells by making use of ex-vivo assays that determine antigen specific CD8 T cell function, such as intracellular cytokine assay, degranulation assay to measure cytotoxicity and viral clearance. Our results are discussed in terms of the beneficial effects of blocking PDL-1 interactions, while giving prophylactic vaccines, to generate a more effective CD8 T cell response to viral infection.

  17. Blocking the proliferation of human tumor cell lines by peptidase inhibitors from Bauhinia seeds.

    Nakahata, Adriana Miti; Mayer, Barbara; Neth, Peter; Hansen, Daiane; Sampaio, Misako Uemura; Oliva, Maria Luiza Vilela

    2013-03-01

    In cancer tumors, growth, invasion, and formation of metastasis at a secondary site play a pivotal role, participating in diverse processes in the development of the pathology, such as degradation of extracellular matrix. Bauhinia seeds contain relatively large quantities of peptidase inhibitors, and two Bauhinia inhibitors were obtained in a recombinant form from the Bauhinia bauhinioides species, B. bauhinoides cruzipain inhibitor, which is a cysteine and serine peptidase inhibitor, and B. bauhinioides kallikrein inhibitor, which is a serine peptidase inhibitor. While recombinant B. bauhinoides cruzipain inhibitor inhibits human neutrophil elastase cathepsin G and the cysteine proteinase cathepsin L, recombinant B. bauhinioides kallikrein inhibitor inhibits plasma kallikrein and plasmin. The effects of recombinant B. bauhinoides cruzipain inhibitor and recombinant B. bauhinioides kallikrein inhibitor on the viability of tumor cell lines with a distinct potential of growth from the same tissue were compared to those of the clinical cytotoxic drug 5-fluorouracil. At 12.5 µM concentration, recombinant B. bauhinoides cruzipain inhibitor and recombinant B. bauhinioides kallikrein inhibitor were more efficient than 5-fluorouracil in inhibiting MKN-28 and Hs746T (gastric), HCT116 and HT29 (colorectal), SkBr-3 and MCF-7 (breast), and THP-1 and K562 (leukemia) cell lines. Additionally, recombinant B. bauhinoides cruzipain inhibitor inhibited 40 % of the migration of Hs746T, the most invasive gastric cell line, while recombinant B. bauhinioides kallikrein inhibitor did not affect cell migration. Recombinant B. bauhinioides kallikrein inhibitor and recombinant B. bauhinoides cruzipain inhibitor, even at high doses, did not affect hMSC proliferation while 5-fluorouracil greatly reduced the proliferation rates of hMSCs. Therefore, both recombinant B. bauhinoides cruzipain inhibitor and recombinant B. bauhinioides kallikrein inhibitor might be considered for further studies

  18. Circulating blocking factors of lymphoid-cell cytotoxicity in x-ray-induced rat small-bowel adenocarcinoma

    Stevens, R.H.; Brooks, G.P.; Osborne, J.W.

    1979-01-01

    Circulating blocking factors capable of abrogating cell-mediated immune responses measured by in vitro lymphoid-cell cytotoxicity were identified in the sera of Holtzman outbred rats 6 to 9 months after a single exposure of only the temporarily exteriorized, hypoxic ileum and jejunum to 1700 to 2000 R of X radiation. Such factors were found to exist in the serum of every animal exposed to the ionizing radiation regardless of whether a visibly identifiable small-bowel adenocarcinoma existed or subsequently would develop. Protection of cultured x-ray-induced rat small-bowel cancer cells from destruction by tumor-sensitized lymphoid cells as measured by the release of lactoperoxidase-catalyzed radioiodinated membrane proteins from the tumor target cells was conferred by the action of the blocking factors at both effector and target cell levels. The results of this study demonstrate that exposure of only the rat small intestine to ionizing radiation leads to elaboration of circulating factors identifiable several months postirradiation which will block cell-mediated immune responses directed against cancer cells developing in the exposed tissue

  19. The TCP4 transcription factor of Arabidopsis blocks cell division in yeast at G1 → S transition

    Aggarwal, Pooja; Padmanabhan, Bhavna; Bhat, Abhay; Sarvepalli, Kavitha; Sadhale, Parag P.; Nath, Utpal

    2011-01-01

    Highlights: → TCP4 is a class II TCP transcription factor, that represses cell division in Arabidopsis. → TCP4 expression in yeast retards cell division by blocking G1 → S transition. → Genome-wide expression studies and Western analysis reveals stabilization of cell cycle inhibitor Sic1, as possible mechanism. -- Abstract: The TCP transcription factors control important aspects of plant development. Members of class I TCP proteins promote cell cycle by regulating genes directly involved in cell proliferation. In contrast, members of class II TCP proteins repress cell division. While it has been postulated that class II proteins induce differentiation signal, their exact role on cell cycle has not been studied. Here, we report that TCP4, a class II TCP protein from Arabidopsis that repress cell proliferation in developing leaves, inhibits cell division by blocking G1 → S transition in budding yeast. Cells expressing TCP4 protein with increased transcriptional activity fail to progress beyond G1 phase. By analyzing global transcriptional status of these cells, we show that expression of a number of cell cycle genes is altered. The possible mechanism of G1 → S arrest is discussed.

  20. Butein activates p53 in hepatocellular carcinoma cells via blocking MDM2-mediated ubiquitination

    Zhou Y

    2018-04-01

    Full Text Available Yuanfeng Zhou,1,2 Kuifeng Wang,2 Ni Zhou,2 Tingting Huang,2 Jiansheng Zhu,2 Jicheng Li1 1Institute of Cell Biology, Zhejiang University, Hangzhou, People’s Republic of China; 2Department of Infectious Diseases, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou, People’s Republic of China Introduction: In this study, we aimed to investigate the effect of butein on p53 in hepatocellular carcinoma (HCC cells and the related molecular mechanisms by which p53 was activated. Methods: MTS assay and clonogenic survival assay were used to examine the antitumor activity of butein in vitro. Reporter gene assay was adopted to evaluate p53 transcriptional activity. Flow cytometry and western blotting were performed to study apoptosis induction and protein expression respectively. Xenograft model was applied to determine the in vivo efficacy and the expression of p53 in tumor tissue was detected by immunohistochemistry. Results: HCC cell proliferation and clonogenic survival were significantly inhibited after butein treatment. With the activation of cleaved-PARP and capsase-3, butein induced apoptosis in HCC cells in a dose-dependent manner. The transcriptional activity of p53 was substantially promoted by butein, and the expression of p53-targeted gene was increased accordingly. Mechanism studies demonstrated that the interaction between MDM2 and p53 was blocked by butein and MDM2-mediated p53 ubiquitination was substantially decreased. Short-hairpin RNA experiment results showed that the sensitivity of HCC cells to butein was substantially impaired after p53 was knocked down and butein-induced apoptosis was dramatically decreased. In vivo experiments validated substantial antitumor efficacy of butein against HepG2 xenograft growth, and the expression of p53 in butein-treated tumor tissue was significantly increased. Conclusion: Butein demonstrated potent antitumor activities in HCC by activating p53, and butein or its analogs had

  1. Nerve Blocks

    ... News Physician Resources Professions Site Index A-Z Nerve Blocks A nerve block is an injection to ... the limitations of Nerve Block? What is a Nerve Block? A nerve block is an anesthetic and/ ...

  2. Coarse mesh and one-cell block inversion based diffusion synthetic acceleration

    Kim, Kang-Seog

    DSA (Diffusion Synthetic Acceleration) has been developed to accelerate the SN transport iteration. We have developed solution techniques for the diffusion equations of FLBLD (Fully Lumped Bilinear Discontinuous), SCB (Simple Comer Balance) and UCB (Upstream Corner Balance) modified 4-step DSA in x-y geometry. Our first multi-level method includes a block Gauss-Seidel iteration for the discontinuous diffusion equation, uses the continuous diffusion equation derived from the asymptotic analysis, and avoids void cell calculation. We implemented this multi-level procedure and performed model problem calculations. The results showed that the FLBLD, SCB and UCB modified 4-step DSA schemes with this multi-level technique are unconditionally stable and rapidly convergent. We suggested a simplified multi-level technique for FLBLD, SCB and UCB modified 4-step DSA. This new procedure does not include iterations on the diffusion calculation or the residual calculation. Fourier analysis results showed that this new procedure was as rapidly convergent as conventional modified 4-step DSA. We developed new DSA procedures coupled with 1-CI (Cell Block Inversion) transport which can be easily parallelized. We showed that 1-CI based DSA schemes preceded by SI (Source Iteration) are efficient and rapidly convergent for LD (Linear Discontinuous) and LLD (Lumped Linear Discontinuous) in slab geometry and for BLD (Bilinear Discontinuous) and FLBLD in x-y geometry. For 1-CI based DSA without SI in slab geometry, the results showed that this procedure is very efficient and effective for all cases. We also showed that 1-CI based DSA in x-y geometry was not effective for thin mesh spacings, but is effective and rapidly convergent for intermediate and thick mesh spacings. We demonstrated that the diffusion equation discretized on a coarse mesh could be employed to accelerate the transport equation. Our results showed that coarse mesh DSA is unconditionally stable and is as rapidly convergent

  3. Polybenzimidazole block copolymers for fuel cell: synthesis and studies of block length effects on nanophase separation, mechanical properties, and proton conductivity of PEM.

    Maity, Sudhangshu; Jana, Tushar

    2014-05-14

    A series of meta-polybenzimidazole-block-para-polybenzimidazole (m-PBI-b-p-PBI), segmented block copolymers of PBI, were synthesized with various structural motifs and block lengths by condensing the diamine terminated meta-PBI (m-PBI-Am) and acid terminated para-PBI (p-PBI-Ac) oligomers. NMR studies and existence of two distinct glass transition temperatures (Tg), obtained from dynamical mechanical analysis (DMA) results, unequivocally confirmed the formation of block copolymer structure through the current polymerization methodology. Appropriate and careful selection of oligomers chain length enabled us to tailor the block length of block copolymers and also to make varieties of structural motifs. Increasingly distinct Tg peaks with higher block length of segmented block structure attributed the decrease in phase mixing between the meta-PBI and para-PBI blocks, which in turn resulted into nanophase segregated domains. The proton conductivities of proton exchange membrane (PEM) developed from phosphoric acid (PA) doped block copolymer membranes were found to be increasing substantially with increasing block length of copolymers even though PA loading of these membranes did not alter appreciably with varying block length. For example when molecular weight (Mn) of blocks were increased from 1000 to 5500 then the proton conductivities at 160 °C of resulting copolymers increased from 0.05 to 0.11 S/cm. Higher block length induced nanophase separation between the blocks by creating less morphological barrier within the block which facilitated the movement of the proton in the block and hence resulting higher proton conductivity of the PEM. The structural varieties also influenced the phase separation and proton conductivity. In comparison to meta-para random copolymers reported earlier, the current meta-para segmented block copolymers were found to be more suitable for PBI-based PEM.

  4. Evidence for Existence of Immunoglobulins that Block Ovarian Granulosa Cell Growth in Vitro. A Putative Role in Resistant Ovary Syndrome?

    WEISSENBRUCH, MIRJAM M. van; HOEK, ANNEMIEKE; VLIET-BLEEKER, INGRID van; SCHOEMAKER, JOOP; DREXHAGE, HEMMO

    1991-01-01

    The sera of 26 patients with premature ovarian failure were examined in order to detect immunoglobulin-G (IgGs) that can block FSH-induced in vitro granulosa cell DNA synthesis via, a Feulgen cytochemical bioassay system. The IgGs of four patients with polycystic ovary-like disease, five

  5. Primary splenic angiosarcoma with liver metastasis: A rare neoplasm diagnosed on fine-needle aspiration cytology and cell block immunocytochemistry

    Saniya Sharma

    2018-01-01

    Full Text Available Primary splenic angiosarcoma is a rare malignant vascular neoplasm of mesenchymal origin. The tumor is highly aggressive and has a high metastatic potential. It is usually diagnosed on histopathological examination of splenectomy specimen. Only few cases of angiosarcoma diagnosed by fine-needle aspiration (FNA cytology alone have been reported in the literature. The cytologic features of angiosarcoma are heterogeneous, however, diagnosis can be suggested by FNA when vasoformative features are present. A 55-year-old female presented with abdominal pain and hepatosplenomegaly. Computed tomography scan revealed a heterogeneous splenic lesion with liver metastases. FNA from the splenic and liver lesions showed moderately pleomorphic tumor cells closely associated with anastomosing vascular channels. Cell block immunocytochemistry (ICC showed tumor cells positive for CD31, CD34, CD68 as well as for CD99. FNA supplemented by cell block ICC can render a definite diagnosis of primary splenic angiosarcoma with liver metastasis.

  6. Saponins from soy bean and mung bean inhibit the antigen specific activation of helper T cells by blocking cell cycle progression.

    Lee, Suk Jun; Bae, Joonbeom; Kim, Sunhee; Jeong, Seonah; Choi, Chang-Yong; Choi, Sang-Pil; Kim, Hyun-Sook; Jung, Woon-Won; Imm, Jee-Young; Kim, Sae Hun; Chun, Taehoon

    2013-02-01

    Treatment of helper T (Th) cells with saponins from soy bean and mung bean prevented their activation by inhibiting cell proliferation and cytokine secretion. However, the saponins did not affect the expression of major histocompatibility complex class II (A(b)) and co-stimulatory molecule (CD86) on professional antigen-presenting cells. Instead, the saponins directly inhibited Th cell proliferation by blocking the G(1) to S phase cell cycle transition. Moreover, blocking of the cell cycle by the saponins was achieved by decreased expression of cyclin D1 and cyclin E, and constitutive expression of p27(KIP1). Saponins also increased stability of p27(KIP1) in Th cells after antigenic stimulation.

  7. Fully Aromatic Block Copolymers for Fuel Cell Membranes with Densely Sulfonated Nanophase Domains

    Takamuku, Shogo; Jannasch, Patrick; Lund, Peter Brilner

    Two multiblock copoly(arylene ether sulfone)s with similar block lengths and ion exchange capacities (IECs) were prepared by a coupling reaction between a non-sulfonated precursor block and a highly sulfonated precursor block containing either fully disulfonated diarylsulfone or fully...... tetrasulfonated tetraaryldisulfone segments. The latter two precursor blocks were sulfonated via lithiation-sulfination reactions whereby the sulfonic acid groups were exclu- sively placed in ortho positions to the many sulfone bridges, giving these locks IECs of 4.1 and 4.6 meqg1, respectively. Copolymer...

  8. Addressing liver fibrosis with Liposomes targeted to hepatic stellate cells

    Adrian, Joanna E.; Poelstra, Klaas; Kamps, Jan A. A. M.

    2007-01-01

    Liver fibrosis is a chronic disease that results from hepatitis B and C infections, alcohol abuse or metabolic and genetic disorders. Ultimately, progression of fibrosis leads to cirrhosis, a stage of the disease characterized by failure of the normal liver functions. Currently, the treatment of

  9. Nanotetrac targets integrin αvβ3 on tumor cells to disorder cell defense pathways and block angiogenesis

    Davis PJ

    2014-09-01

    Full Text Available Paul J Davis,1,2 Hung-Yun Lin,2,3 Thangirala Sudha,2 Murat Yalcin,2,4 Heng-Yuan Tang,2 Aleck Hercbergs,5 John T Leith,6 Mary K Luidens,1 Osnat Ashur-Fabian,7,8 Sandra Incerpi,9 Shaker A Mousa2 1Department of Medicine, Albany Medical College, Albany, NY, USA; 2Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Albany, NY, USA; 3PhD Program for Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; 4Department of Physiology, Veterinary Medicine Faculty, Uludag University, Gorukle, Bursa, Turkey; 5Radiation Oncology, Cleveland Clinic, Cleveland, OH, USA; 6Rhode Island Nuclear Science Center, Narragansett, RI, USA; 7Translational Hemato-oncology Laboratory, Hematology Institute and Blood Bank, Meir Medical Center, Kfar-Saba, Israel; 8Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; 9Department of Sciences, University of Roma Tre, Rome, Italy Abstract: The extracellular domain of integrin αvβ3 contains a receptor for thyroid hormone and hormone analogs. The integrin is amply expressed by tumor cells and dividing blood vessel cells. The proangiogenic properties of thyroid hormone and the capacity of the hormone to promote cancer cell proliferation are functions regulated nongenomically by the hormone receptor on αvβ3. An L-thyroxine (T4 analog, tetraiodothyroacetic acid (tetrac, blocks binding of T4 and 3,5,3'-triiodo-L-thyronine (T3 by αvβ3 and inhibits angiogenic activity of thyroid hormone. Covalently bound to a 200 nm nanoparticle that limits its activity to the cell exterior, tetrac reformulated as Nanotetrac has additional effects mediated by αvβ3 beyond the inhibition of binding of T4 and T3 to the integrin. These actions of Nanotetrac include disruption of transcription of cell survival pathway genes, promotion of apoptosis by multiple mechanisms, and interruption

  10. Comparison of three techniques for generation of tolerogenic dendritic cells: siRNA, oligonucleotide antisense, and antibody blocking.

    Karimi, Mohammad Hossein; Ebadi, Padideh; Pourfathollah, Ali Akbar; Moazzeni, Mohammad; Soheili, Zahra Soheila; Samiee, Shahram

    2010-12-01

    In recent years, a new view of dendritic cells (DCs) as a main regulator of immunity to induce and maintain tolerance has been established. In vitro manipulation of their development and maturation is a topic of DC therapeutic application, which utilizes their inherent tolerogenicity. In this field, the therapeutic potential of antisense, siRNA, and blocking antibody are an interesting goal. In the present study, the efficiency of these three methods--siRNA, antisense, and blocking antibody--against CD40 molecule and its function in DCs and BCL1 cell line are compared. DCs were separated from mouse spleen and then cultured in vitro using Lipofectamine 2000 to deliver both silencers; the efficacy of transfection was estimated by flow cytometry. mRNA expression and protein synthesis were assessed by real time-PCR and flow cytometry, respectively. By Annexin V and propidium iodine staining, we could evaluate the viability of transfected cells. Knocking down the CD40 gene into separate groups of DCs by siRNA, antisense, and blocking antibody treated DCs can cause an increase in IL-4, decrease in IL-12, IFN-γ production, and allostimulation activity. Our results indicated that, in comparison to antisense and blocking antibody, siRNAs appear to be quantitatively more efficient in CD40 downregulation and their differences are significant.

  11. Autolyse the cell in order to save it? Inducing, then blocking, autolysis as a strategy for delaying cell death in the probiotic Lactobacillus reuteri.

    Zimmerman, Tahl; Gyawali, Rabin; Ibrahim, Salam

    2017-10-01

    To examine whether choline and its derivatives can be used to preserve viable cells of Lactobacillus reuteri in autolytic models. A phosphate-induced autolytic model in de Man, Rogosa and Sharpe medium (MRS) was used. Viable cell counts were determined by plated on MRS-agar. Choline and hemicholinium-3 (HC-3) significantly blocked autolysis of L. reuteri at 360 mM and 4 mM, respectively. Viable cell counts corroborated these observations. Importantly, autolytically induced cells treated with choline and hemicholinium-3 were significantly more viable then even non-induced cells. Over-production of a known autolytic protein, spirosin, was not attenuated in the presence of choline and hemicholinium-3. Inducing autolysis and then blocking it with choline and its analogs is a promising approach for retaining the viability of L. reuteri cells.

  12. Well-defined block copolymers for gene delivery to dendritic cells: probing the effect of polycation chain-length.

    Tang, Rupei; Palumbo, R Noelle; Nagarajan, Lakshmi; Krogstad, Emily; Wang, Chun

    2010-03-03

    The development of safe and efficient polymer carriers for DNA vaccine delivery requires mechanistic understanding of structure-function relationship of the polymer carriers and their interaction with antigen-presenting cells. Here we have synthesized a series of diblock copolymers with well-defined chain-length using atom transfer radical polymerization and characterized the influence of polycation chain-length on the physico-chemical properties of the polymer/DNA complexes as well as the interaction with dendritic cells. The copolymers consist of a hydrophilic poly(ethylene glycol) block and a cationic poly(aminoethyl methacrylate) (PAEM) block. The average degree of polymerization (DP) of the PAEM block was varied among 19, 39, and 75, with nearly uniform distribution. With increasing PAEM chain-length, polyplexes formed by the diblock copolymers and plasmid DNA had smaller average particle size and showed higher stability against electrostatic destabilization by salt and heparin. The polymers were not toxic to mouse dendritic cells (DCs) and only displayed chain-length-dependent toxicity at a high concentration (1mg/mL). In vitro gene transfection efficiency and polyplex uptake in DCs were also found to correlate with chain-length of the PAEM block with the longer polymer chain favoring transfection and cellular uptake. The polyplexes induced a modest up-regulation of surface markers for DC maturation that was not significantly dependent on PAEM chain-length. Finally, the polyplex prepared from the longest PAEM block (DP of 75) achieved an average of 20% enhancement over non-condensed anionic dextran in terms of uptake by DCs in the draining lymph nodes 24h after subcutaneous injection into mice. Insights gained from studying such structurally well-defined polymer carriers and their interaction with dendritic cells may contribute to improved design of practically useful DNA vaccine delivery systems. Copyright 2009 Elsevier B.V. All rights reserved.

  13. Modulation of radiation-induced apoptosis and G{sub 2}/M block in murine T-lymphoma cells

    Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N. [Harvard Medical School, Boston, MA (United States)

    1995-03-01

    Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to {sup 137}Cs {gamma} irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of {gamma} radiation. We studied the effect of several pharmacological agents on the radiation-induced G{sub 2}/M block and DNA fragmentation. The agents which reduced the radiation-induced G{sub 2}/M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the radiation-induced G{sub 2}/M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with radiation-induced genetic damage are eliminated by apoptosis subsequent to a G{sub 2}/M block. Furthermore, it may be possible to modulate the process of radiation-induced apoptosis in lymphoma cells with pharmacological agents that modify the radiation-induced G{sub 2}/M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs.

  14. Modulation of radiation-induced apoptosis and G2/M block in murine T-lymphoma cells

    Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N.

    1995-01-01

    Radiation-induced apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after radiation exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to 137 Cs γ irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of γ radiation. We studied the effect of several pharmacological agents on the radiation-induced G 2 /M block and DNA fragmentation. The agents which reduced the radiation-induced G 2 /M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the radiation-induced G 2 /M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with radiation-induced genetic damage are eliminated by apoptosis subsequent to a G 2 /M block. Furthermore, it may be possible to modulate the process of radiation-induced apoptosis in lymphoma cells with pharmacological agents that modify the radiation-induced G 2 /M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs

  15. Arctigenin induces cell cycle arrest by blocking the phosphorylation of Rb via the modulation of cell cycle regulatory proteins in human gastric cancer cells.

    Jeong, Jin Boo; Hong, Se Chul; Jeong, Hyung Jin; Koo, Jin Suk

    2011-10-01

    Gastric cancer is a leading cause of cancer-related deaths, worldwide being second only to lung cancer as a cause of death. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms of arctigenin for anti-tumor effect on gastric cancer have not been examined. This study examined the biological effects of arctigenin on the human gastric cancer cell line SNU-1 and AGS. Cell proliferation was determined by MTT assay. In MTT assay, the proliferation of SNU-1 and AGS cells was significantly inhibited by arctigenin in a time and dose dependent manner, as compared with SNU-1 and AGS cells cultured in the absence of arctigenin. Inhibition of cell proliferation by arctigenin was in part associated with apoptotic cell death, as shown by changes in the expression ratio of Bcl-2 to Bax by arctigenin. Also, arctigenin blocked cell cycle arrest from G(1) to S phase by regulating the expression of cell cycle regulatory proteins such as Rb, cyclin D1, cyclin E, CDK4, CDK2, p21Waf1/Cip1 and p15 INK4b. The antiproliferative effect of arctigenin on SNU-1 and AGS gastric cancer cells revealed in this study suggests that arctigenin has intriguing potential as a chemopreventive or chemotherapeutic agent. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  16. Block effect on HCV infection by HMGB1 released from virus-infected cells: An insight from mathematical modeling

    Wang, Wei; Ma, Wanbiao

    2018-06-01

    The nuclear protein high-mobility group box 1 (HMGB1) can have an active role in deoxyribonucleic acid (DNA) organization and the regulation of transcription. Based on the new findings from a recent experimental study, the blocking effect on HCV infection by HMGB1 released from virus-infected cells is investigated using a diffusive model for viral infection dynamics. In the model, the diffusion of the virus depends not only on its concentration gradient, but also on the concentration of HMGB1. The basic reproduction number, threshold dynamics, stability properties of the steady states, travelling wave solutions, and spreading speed for the proposed model are studied. We show that the HMGB1-induced blocking of HCV infection slows the spread of virus compared with random diffusion only. Numerically, it is shown that a high concentration of HMGB1 can block the spread of virus and this confirms, not only qualitatively but also quantitatively, the experimental result.

  17. Sequence of activation of template biosyntheses in normal and transformed human cells after synchronization with a double thimidine block

    Alekseev, S.B.; Boikov, P.Ya.; Ebralidze, L.K.; Stepanova, L.G.

    1986-01-01

    The sequences of synthesis of DNA, RNA, and various groups of proteins in normal and transformed human fibroblasts was studied in the first mitotic cycle synchronization of the cells by a double thymidine block. Two peculiarities of the synthesis of acid-soluble histone and acid-insoluble proteins in the normal and transformed cells, were detected: (1) in normal fibroblasts the synthesis of the two groups of proteins is a minimum before DNA replication, and the greatest activity is achieved in the G 2 phase; in transformed cells protein synthesis is a maximum after the removal of the thymine block, while in the G 2 phase it is decreased; (2) in normal fibroblasts the synthesis of acid-insoluble proteins is a maximum before the maximum synthesis of DNA, and that of acid-soluble proteins is a maximum after the maximum of DNA synthesis. The opposite picture is observed in transformed cells. RNA synthesis in normal and transformed cells is activated at the end of the G 2 phase. In normal cells the synthesis of proteins is coupled with the activation of RNA synthesis, while in transformed cells protein synthesis is evidently transferred to the following mitotic cycle. Especially pronounced differences were detected in the expression of certain LMG proteins. Thus, in transformed cells the regulation of the coupling of the template syntheses is modified

  18. Very thin thermally stable TiO2 blocking layers with enhanced electron transfer for solar cells

    Kment, Š.; Krýsová, Hana; Hubička, Zdeněk; Kmentová, H.; Kavan, Ladislav; Zbořil, R.

    2017-01-01

    Roč. 9, DEC 2017 (2017), s. 122-129 ISSN 2352-9407 R&D Projects: GA MŠk(CZ) LM2015073; GA ČR GA13-07724S Grant - others:GA MŠk(CZ) LO1305 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Cyclic voltammetry * Impedance spectroscopy * Photochemistry * Solar cell * TiO blocking layer 2 Subject RIV: CG - Electrochemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis); Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)

  19. Validation of 31 of the most commonly used immunohistochemical antibodies in cytology prepared using the Cellient(®) automated cell block system.

    Montgomery, Eric; Gao, Chen; de Luca, Julie; Bower, Jessie; Attwood, Kristropher; Ylagan, Lourdes

    2014-12-01

    The Cellient(®) cell block system has become available as an alternative, partially automated method to create cell blocks in cytology. We sought to show a validation method for immunohistochemical (IHC) staining on the Cellient cell block system (CCB) in comparison with the formalin fixed paraffin embedded traditional cell block (TCB). Immunohistochemical staining was performed using 31 antibodies on 38 patient samples for a total of 326 slides. Split samples were processed using both methods by following the Cellient(®) manufacturer's recommendations for the Cellient cell block (CCB) and the Histogel method for preparing the traditional cell block (TCB). Interpretation was performed by three pathologists and two cytotechnologists. Immunohistochemical stains were scored as: 0/1+ (negative) and 2/3+ (positive). Inter-rater agreement for each antibody was evaluated for CCB and TCB, as well as the intra-rater agreement between TCB and CCB between observers. Interobserver staining concordance for the TCB was obtained with statistical significance (P Cellient system are reliable and concordant with stains performed on the same split samples processed via a formalin fixed-paraffin embedded (FFPE) block. The Cellient system is a welcome adjunct to cytology work-flow by producing cell block material of sufficient quality to allow the use of routine IHC. © 2014 Wiley Periodicals, Inc.

  20. The Cellient automated cell block system is useful in the differential diagnosis of atypical glandular cells in Papanicolaou tests.

    Xing, Wei; Hou, April Y; Fischer, Andrew; Owens, Christopher L; Jiang, Zhong

    2014-01-01

    Atypical glandular cells (AGC) is a very important diagnosis in gynecological cytology. In the current study, the authors investigated the usefulness of Cellient cell blocks (CB) for characterizing AGC on Papanicolaou (Pap) tests. A total of 148 patients with an AGC diagnosis based on Pap tests by cytotechnologists and referred to cytopathologists were studied. Among these patients, there were 68 patients with CB preparations and 80 patients with Pap tests only (TP-AGC group). Follow-up results by Pap tests or biopsies were obtained in 117 of 148 patients. The median follow-up was 13 months (range, 1 month-36 months). Of the 68 patients with CBs, 31 (46%) were reclassified as negative for dysplasia or low-grade intraepithelial lesion; 30 patients (44%) retained a diagnosis of AGC (CB-AGC group); and 7 patients (10%) were given specific diagnoses of high-grade intraepithelial lesion (3 patients), endocervical adenocarcinoma in situ (1 patient), and invasive adenocarcinoma (3 patients). On follow-up, the CB-AGC group was found to have a significantly lower rate of negative/low-grade squamous intraepithelial lesion diagnoses compared with the TP-AGC group (55% vs 85%; P= .006). The CB-AGC group had a significantly higher rate of endocervical or endometrial adenocarcinoma compared with the TP-AGC group (36% vs 8%; P= .003) at the time of follow-up. The rates of high-grade squamous intraepithelial lesion were not found to be statistically different between these 2 groups (9% vs 7%; P= .66). The Cellient CB is a useful technique to further categorize a diagnosis of AGC on Pap tests. Using the Cellient CB system, the pathologist has the ability to improve the diagnostic accuracy of AGC so that unnecessary colposcopic evaluation or biopsies can be avoided. © 2013 American Cancer Society.

  1. The state of cell block variation and satisfaction in the era of molecular diagnostics and personalized medicine

    Crapanzano, John P.; Heymann, Jonas J.; Monaco, Sara; Nassar, Aziza; Saqi, Anjali

    2014-01-01

    Background: In the recent past, algorithms and recommendations to standardize the morphological, immunohistochemical and molecular classification of lung cancers on cytology specimens have been proposed, and several organizations have recommended cell blocks (CBs) as the preferred modality for molecular testing. Based on the literature, there are several different techniques available for CB preparation-suggesting that there is no standard. The aim of this study was to conduct a survey of CB ...

  2. Blocking the NOTCH pathway can inhibit the growth of CD133-positive A549 cells and sensitize to chemotherapy

    Liu, Juntao; Mao, Zhangfan; Huang, Jie; Xie, Songping; Liu, Tianshu; Mao, Zhifu, E-mail: 48151660@qq.com

    2014-02-21

    Highlights: • Notch signaling pathway members are expressed lower levels in CD133+ cells. • CD133+ cells are not as sensitive as CD133− cells to chemotherapy. • GSI could inhibit the growth of both CD133+ and CD133− cells. • Blockade of Notch signaling pathway enhanced the effect of chemotherapy with CDDP. • DAPT/CDDP co-therapy caused G2/M arrest and elimination in CD133+ cells. - Abstract: Cancer stem cells (CSCs) are believed to play an important role in tumor growth and recurrence. These cells exhibit self-renewal and proliferation properties. CSCs also exhibit significant drug resistance compared with normal tumor cells. Finding new treatments that target CSCs could significantly enhance the effect of chemotherapy and improve patient survival. Notch signaling is known to regulate the development of the lungs by controlling the cell-fate determination of normal stem cells. In this study, we isolated CSCs from the human lung adenocarcinoma cell line A549. CD133 was used as a stem cell marker for fluorescence-activated cell sorting (FACS). We compared the expression of Notch signaling in both CD133+ and CD133− cells and blocked Notch signaling using the γ-secretase inhibitor DAPT (GSI-IX). The effect of combining GSI and cisplatin (CDDP) was also examined in these two types of cells. We observed that both CD133+ and CD133− cells proliferated at similar rates, but the cells exhibited distinctive differences in cell cycle progression. Few CD133+ cells were observed in the G{sub 2}/M phase, and there were half as many cells in S phase compared with the CD133− cells. Furthermore, CD133+ cells exhibited significant resistance to chemotherapy when treated with CDDP. The expression of Notch signaling pathway members, such as Notch1, Notch2 and Hes1, was lower in CD133+ cells. GSI slightly inhibited the proliferation of both cell types and exhibited little effect on the cell cycle. The inhibitory effects of DPP on these two types of cells were

  3. Activation of the canonical Wnt pathway leads to loss of hematopoietic stem cell repopulation and multilineage differentiation block

    Kirstetter, Peggy; Anderson, Kristina; Porse, Bo T

    2006-01-01

    Wnt signaling increases hematopoietic stem cell self-renewal and is activated in both myeloid and lymphoid malignancies, indicating involvement in both normal and malignant hematopoiesis. We report here activated canonical Wnt signaling in the hematopoietic system through conditional expression...... of hematopoietic stem cell function was associated with decreased expression of Cdkn1a (encoding the cell cycle inhibitor p21(cdk)), Sfpi1, Hoxb4 and Bmi1 (encoding the transcription factors PU.1, HoxB4 and Bmi-1, respectively) and altered integrin expression in Lin(-)Sca-1(+)c-Kit(+) cells, whereas PU.1...... of a stable form of beta-catenin. This enforced expression led to hematopoietic failure associated with loss of myeloid lineage commitment at the granulocyte-macrophage progenitor stage; blocked erythrocyte differentiation; disruption of lymphoid development; and loss of repopulating stem cell activity. Loss...

  4. Developmental block and programmed cell death in Bos indicus embryos: effects of protein supplementation source and developmental kinetics.

    Sheila Merlo Garcia

    Full Text Available The aims of this study were to determine if the protein source of the medium influences zebu embryo development and if developmental kinetics, developmental block and programmed cell death are related. The culture medium was supplemented with either fetal calf serum or bovine serum albumin. The embryos were classified as Fast (n = 1,235 or Slow (n = 485 based on the time required to reach the fourth cell cycle (48 h and 90 h post insemination - hpi -, respectively. The Slow group was further separated into two groups: those presenting exactly 4 cells at 48 hpi (Slow/4 cells and those that reached the fourth cell cycle at 90 hpi (Slow. Blastocyst quality, DNA fragmentation, mitochondrial membrane potential and signs of apoptosis or necrosis were evaluated. The Slow group had higher incidence of developmental block than the Fast group. The embryos supplemented with fetal calf serum had lower quality. DNA fragmentation and mitochondrial membrane potential were absent in embryos at 48 hpi but present at 90 hpi. Early signs of apoptosis were more frequent in the Slow and Slow/4 cell groups than in the Fast group. We concluded that fetal calf serum reduces blastocyst development and quality, but the mechanism appears to be independent of DNA fragmentation. The apoptotic cells detected at 48 hpi reveal a possible mechanism of programmed cell death activation prior to genome activation. The apoptotic cells observed in the slow-developing embryos suggested a relationship between programmed cell death and embryonic developmental kinetics in zebu in vitro-produced embryos.

  5. Enrichment with Wood Blocks Does Not Affect Toxicity Assessment in an Exploratory Toxicology Model Using Sprague–Dawley Rats

    Ditewig, Amy C; Bratcher, Natalie A; Davila, Donna R; Dayton, Brian D; Ebert, Paige; Lesuisse, Philippe; Liguori, Michael J; Wetter, Jill M; Yang, Hyuna; Buck, Wayne R

    2014-01-01

    Environmental enrichment in rodents may improve animal well-being but can affect neurologic development, immune system function, and aging. We tested the hypothesis that wood block enrichment affects the interpretation of traditional and transcriptomic endpoints in an exploratory toxicology testing model using a well-characterized reference compound, cyclophosphamide. ANOVA was performed to distinguish effects of wood block enrichment separate from effects of 40 mg/kg cyclophosphamide treatment. Biologically relevant and statistically significant effects of wood block enrichment occurred only for body weight gain. ANOVA demonstrated the expected effects of cyclophosphamide on food consumption, spleen weight, and hematology. According to transcriptomic endpoints, cyclophosphamide induced fewer changes in gene expression in liver than in spleen. Splenic transcriptomic pathways affected by cyclophosphamide included: iron hemostasis; vascular tissue angiotensin system; hepatic stellate cell activation and fibrosis; complement activation; TGFβ-induced hypertrophy and fibrosis; monocytes, macrophages, and atherosclerosis; and platelet activation. Changes in these pathways due to cyclophosphamide treatment were consistent with bone marrow toxicity regardless of enrichment. In a second study, neither enrichment nor type of cage flooring altered body weight or food consumption over a 28-d period after the first week. In conclusion, wood block enrichment did not interfere with a typical exploratory toxicology study; the effects of ingested wood on drug level kinetics may require further consideration. PMID:24827566

  6. Recovery of DNA synthesis after ultraviolet irradiation of xeroderma pigmentosum cells depends on excision repair and is blocked by caffeine

    Park, S.D.; Cleaver, J.E.

    1979-01-01

    Normal human and xeroderma pigmentosum (XP, excision-defective group A) cells (both SV40-transformed) pulse-labeled with [ 3 H] thymidine at various times after irradiation with ultraviolet light showed a decline and recovery of both the molecular weights of newly synthesized DNA and the rated of synthesis per cell. At the same ultraviolet dose, both molecular weights and rates of synthesis were inhibited more in XP than in normal cells. This indicates that excision repair plays a role in minimizing the inhibition of chain growth, possibly by excision of dimers ahead of the growing point. The ability to synthesize normal-sized DNA recovered more rapidly than rates of synthesis in normal cells, but both parameters recovered in phase in XP cells. During recovery in normal cells there are therefore fewer actively replicating clusters of replicons because the single-strand breaks involved in the excision of dimers inhibit replicon initiation. XP cells have few excision repair events and therefore fewer breaks to interfere with initiation, but chain growth is blocked by unexcised dimers. In both cell types recovery of the ability to synthesize normal-sized DNA was prevented by growing cells in caffeine after irradiation, possibly because of competition between the DNA binding properties of caffeine and replication proteins. These observations imply that excision repair and semiconservative replication interact strongly in irradiated cells to produce a complex spectrum of changes in DNA replication which may be confused with parts of alternative systems such as post-replication repair. (author)

  7. A novel anti-EMMPRIN function-blocking antibody reduces T cell proliferation and neurotoxicity: relevance to multiple sclerosis.

    Agrawal, Smriti M; Silva, Claudia; Wang, Janet; Tong, Jade Pui-Wai; Yong, V Wee

    2012-04-05

    Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147, basigin) is an inducer of the expression of several matrix metalloproteinases (MMPs). We reported previously that blocking EMMPRIN activity reduced neuroinflammation and severity of disease in an animal model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). To improve upon EMMPRIN blockade, and to help unravel the biological functions of EMMPRIN in inflammatory disorders, we have developed several anti-EMMPRIN monoclonal antibodies. Of these monoclonal antibodies, a particular one, clone 10, was efficient in binding mouse and human cells using several methods of detection. The specificity of clone 10 was demonstrated by its lack of staining of EMMPRIN-null embryos compared to heterozygous and wild-type mouse samples. Functionally, human T cells activated with anti-CD3 and anti-CD28 elevated their expression of EMMPRIN and the treatment of these T cells with clone 10 resulted in decreased proliferation and matrix metalloproteinase- 9 (MMP-9) production. Activated human T cells were toxic to human neurons in culture and clone 10 pretreatment reduced T cell cytotoxicity correspondent with decrease of granzyme B levels within T cells. In vivo, EAE mice treated with clone 10 had a markedly reduced disease score compared to mice treated with IgM isotype control. We have produced a novel anti-EMMPRIN monoclonal antibody that blocks several aspects of T cell activity, thus highlighting the multiple roles of EMMPRIN in T cell biology. Moreover, clone 10 reduces EAE scores in mice compared to controls, and has activity on human cells, potentially allowing for the testing of anti-EMMPRIN treatment not only in EAE, but conceivably also in MS.

  8. A novel anti-EMMPRIN function-blocking antibody reduces T cell proliferation and neurotoxicity: relevance to multiple sclerosis

    Agrawal Smriti M

    2012-04-01

    Full Text Available Abstract Background Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147, basigin is an inducer of the expression of several matrix metalloproteinases (MMPs. We reported previously that blocking EMMPRIN activity reduced neuroinflammation and severity of disease in an animal model of multiple sclerosis (MS, experimental autoimmune encephalomyelitis (EAE. Methods To improve upon EMMPRIN blockade, and to help unravel the biological functions of EMMPRIN in inflammatory disorders, we have developed several anti-EMMPRIN monoclonal antibodies. Results Of these monoclonal antibodies, a particular one, clone 10, was efficient in binding mouse and human cells using several methods of detection. The specificity of clone 10 was demonstrated by its lack of staining of EMMPRIN-null embryos compared to heterozygous and wild-type mouse samples. Functionally, human T cells activated with anti-CD3 and anti-CD28 elevated their expression of EMMPRIN and the treatment of these T cells with clone 10 resulted in decreased proliferation and matrix metalloproteinase- 9 (MMP-9 production. Activated human T cells were toxic to human neurons in culture and clone 10 pretreatment reduced T cell cytotoxicity correspondent with decrease of granzyme B levels within T cells. In vivo, EAE mice treated with clone 10 had a markedly reduced disease score compared to mice treated with IgM isotype control. Conclusions We have produced a novel anti-EMMPRIN monoclonal antibody that blocks several aspects of T cell activity, thus highlighting the multiple roles of EMMPRIN in T cell biology. Moreover, clone 10 reduces EAE scores in mice compared to controls, and has activity on human cells, potentially allowing for the testing of anti-EMMPRIN treatment not only in EAE, but conceivably also in MS.

  9. Cell Penetrating Polymers Containing Guanidinium Trigger Apoptosis in Human Hepatocellular Carcinoma Cells unless Conjugated to a Targeting N-Acetyl-Galactosamine Block.

    Tan, Zhe; Dhande, Yogesh K; Reineke, Theresa M

    2017-12-20

    A series of 3-guanidinopropyl methacrylamide (GPMA)-based polymeric gene delivery vehicles were developed via aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers have been evaluated for their cellular internalization ability, transfection efficiency, and cytotoxicity. Two homopolymers: P(GPMA 20 ), P(GPMA 34 ), were synthesized to study the effect of guanidium polymer length on delivery efficiency and toxicity. In addition, an N-acetyl-d-galactosamine (GalNAc)-based hydrophilic block was incorporated to produce diblock polymers, which provides a neutral hydrophilic block that sterically protects plasmid-polymer complexes (polyplexes) from colloidal aggregation and aids polyplex targeting to hepatocytes via binding to asialoglycoprotein receptors (ASGPRs). Polyplexes formed with P(GPMA x ) (x = 20, 34) homopolymers were shown to be internalized via both energy-dependent and independent pathways, whereas polyplexes formed with block polymers were internalized through endocytosis. Notably, P(GPMA x ) polyplexes enter cells very efficiently but are also very toxic to human hepatocellular carcinoma (HepG2) cells and triggered cell apoptosis. In comparison, the presence of a carbohydrate block in the polymer structures reduced the cytotoxicity of the polyplex formulations and increased gene delivery efficiency with HepG2 cells. Transfection efficiency and toxicity studies were also carried out with HEK 293T (human embryonic kidney) cells for comparison. Results showed that polyplexes formed with the P(GPMA x ) homopolymers exhibit much higher transfection efficiency and lower toxicity with HEK 293T cells. The presence of the carbohydrate block did not further increase transfection efficiency in comparison to the homopolymers with HEK 293T cells, likely due to the lack of ASGPRs on the HEK 293T cell line. This study revealed that although guanidinium-based polymers have high membrane permeability, their application as plasmid

  10. Override of the radiation-induced mitotic block in human tumour cells by methylxanthines and its relationship to the potentiation of cytotoxicity

    Musk, S.R.R.; Steel, G.G.

    1990-01-01

    Caffeine, theophylline, theobromine and paraxanthine, were tested for ability to override mitotic block induced by ionizing radiation in the human bladder carcinoma cell line RT112. All were found to partially override the block, at a concentration of 1mM in the order caffeine > theophylline > theobromine = paraxanthine. At a concentration of 1 mM only caffeine was found to potentiate cell killing as well as causing block override; at higher concentrations all had a significant effect on survival but little or no further influence on the degree of block override. It is concluded that override of a mitotic block is not in itself sufficient to cause increased killing when irradiated cells are incubated in the presence of caffeine, and that caffeine exerts its potentiating effect by directly inhibiting repair of damage in DNA or by causing override of radiation-induced inhibition of DNA synthesis. (author)

  11. Override of the radiation-induced mitotic block in human tumour cells by methylxanthines and its relationship to the potentiation of cytotoxicity

    Musk, S.R.R.; Steel, G.G. (Institute of Cancer Research, Sutton (UK). Surrey Branch)

    1990-06-01

    Caffeine, theophylline, theobromine and paraxanthine, were tested for ability to override mitotic block induced by ionizing radiation in the human bladder carcinoma cell line RT112. All were found to partially override the block, at a concentration of 1mM in the order caffeine > theophylline > theobromine = paraxanthine. At a concentration of 1 mM only caffeine was found to potentiate cell killing as well as causing block override; at higher concentrations all had a significant effect on survival but little or no further influence on the degree of block override. It is concluded that override of a mitotic block is not in itself sufficient to cause increased killing when irradiated cells are incubated in the presence of caffeine, and that caffeine exerts its potentiating effect by directly inhibiting repair of damage in DNA or by causing override of radiation-induced inhibition of DNA synthesis. (author).

  12. Bulk heterojunction perovskite solar cells based on room temperature deposited hole-blocking layer: Suppressed hysteresis and flexible photovoltaic application

    Chen, Zhiliang; Yang, Guang; Zheng, Xiaolu; Lei, Hongwei; Chen, Cong; Ma, Junjie; Wang, Hao; Fang, Guojia

    2017-05-01

    Perovskite solar cells have developed rapidly in recent years as the third generation solar cells. In spite of the great improvement achieved, there still exist some issues such as undesired hysteresis and indispensable high temperature process. In this work, bulk heterojunction perovskite-phenyl-C61-butyric acid methyl ester solar cells have been prepared to diminish hysteresis using a facile two step spin-coating method. Furthermore, high quality tin oxide films are fabricated using pulse laser deposition technique at room temperature without any annealing procedure. The as fabricated tin oxide film is successfully applied in bulk heterojunction perovskite solar cells as a hole blocking layer. Bulk heterojunction devices based on room temperature tin oxide exhibit almost hysteresis-free characteristics with power conversion efficiency of 17.29% and 14.0% on rigid and flexible substrates, respectively.

  13. (E,Z)-3-(3',5'-Dimethoxy-4'-hydroxy-benzylidene)-2-indolinone blocks mast cell degranulation.

    Kiefer, S; Mertz, A C; Koryakina, A; Hamburger, M; Küenzi, P

    2010-05-12

    (E,Z)-3-(3',5'-Dimethoxy-4'-hydroxy-benzylidene)-2-indolinone (indolinone) is an alkaloid that has been identified as a pharmacologically active compound in extracts of the traditional anti-inflammatory herb Isatis tinctoria. Indolinone has been shown to inhibit compound 48/80-induced mast cell degranulation in vitro. Application of indolinone to bone marrow derived mast cells showed that it was uniformly distributed in the cytoplasm and that cellular uptake was terminated within minutes. Pre-treatment of IgE-sensitized mast cells with 100nM indolinone rendered them insensitive against FcvarepsilonRI-receptor dependent degranulation. However, upstream signalling induced by antigen such as activation of PI3-K and MAPK remained unaffected. We conclude that indolinone blocks mast cell degranulation at the level of granule exocitosis with an IC(50) of 54nm.

  14. Fluorinated building blocks for next-generation polymer electrolyte membrane fuel cells

    Wadekar, M.N.

    2012-01-01

    The purpose of this thesis is to design, create and study basic building blocks for the construction of self-assembled nanostructured electrodes and membranes for PEMFC. The research described deals with the synthesis of polymerizable fluorosurfactant (1) and its non-polymerizable analogue (2) and

  15. Nanoparticle-cell interactions: surface chemistry effects on the cellular uptake of biocompatible block copolymer assemblies

    de Castro, C. E.; Ribeiro, C. A. S.; Alavarse, A. C.; Albuquerque, L. J. C.; da Silva, M. C. C.; Jäger, Eliezer; Surman, František; Schmidt, V.; Giacomelli, C.; Giacomelli, F. C.

    2018-01-01

    Roč. 34, č. 5 (2018), s. 2180-2188 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GA17-09998S Institutional support: RVO:61389013 Keywords : biocompatibility * block copolymers * controlled drug delivery Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.833, year: 2016

  16. Influence of different TiO{sub 2} blocking films on the photovoltaic performance of perovskite solar cells

    Zhang, Chenxi; Luo, Yudan; Chen, Xiaohong, E-mail: xhchen@phy.ecnu.edu.cn; Ou-Yang, Wei; Chen, Yiwei; Sun, Zhuo; Huang, Sumei, E-mail: smhuang@phy.ecnu.edu.cn

    2016-12-01

    Highlights: • TiO{sub 2} blocking layer (BL) was synthesized using various methods. • Effect of BL characteristics on performance of perovskite solar cell was studied. • Charge transfer kinetics of perovskite solar cells with different BLs was explored. • We demonstrated efficient solar cells employing chemical bath deposition based BLs. - Abstract: Organolead trihalide perovskite materials have been successfully used as light absorbers in efficient photovoltaic (PV) cells. Cell structures based on mesoscopic metal oxides and planar heterojunctions have already demonstrated very impressive and brisk advances, holding great potential to grow into a mature PV technology. High power conversion efficiency (PCE) values have been obtained from the mesoscopic configuration in which a few hundred nano-meter thick mesoporous scaffold (e.g. TiO{sub 2} or Al{sub 2}O{sub 3}) infiltrated by perovskite absorber was sandwiched between the electron and hole transport layers. A uniform and compact hole-blocking layer is necessary for high efficient perovskite-based thin film solar cells. In this study, we investigated the characteristics of TiO{sub 2} compact layer using various methods and its effects on the PV performance of perovskite solar cells. TiO{sub 2} compact layer was prepared by a sol-gel method based on titanium isopropoxide and HCl, spin-coating of titanium diisopropoxide bis (acetylacetonate), screen-printing of Dyesol’s bocking layer titania paste, and a chemical bath deposition (CBD) technique via hydrolysis of TiCl{sub 4}, respectively. The morphological and micro-structural properties of the formed compact TiO{sub 2} layers were characterized by scanning electronic microscopy and X-ray diffraction. The analyses of devices performance characteristics showed that surface morphologies of TiO{sub 2} compact films played a critical role in affecting the efficiencies. The nanocrystalline TiO{sub 2} film deposited via the CBD route acts as the most efficient

  17. Engineering cell factories for producing building block chemicals for bio-polymer synthesis

    Tsuge, Yota; Kawaguchi, Hideo; Sasaki, Kengo; Kondo, Akihiko

    2016-01-01

    Synthetic polymers are widely used in daily life. Due to increasing environmental concerns related to global warming and the depletion of oil reserves, the development of microbial-based fermentation processes for the production of polymer building block chemicals from renewable resources is desirable to replace current petroleum-based methods. To this end, strains that efficiently produce the target chemicals at high yields and productivity are needed. Recent advances in metabolic engineerin...

  18. Blocking anaplerotic entry of glutamine into the TCA cycle sensitizes K-Ras mutant cancer cells to cytotoxic drugs.

    Saqcena, M; Mukhopadhyay, S; Hosny, C; Alhamed, A; Chatterjee, A; Foster, D A

    2015-05-14

    Cancer cells undergo a metabolic transformation that allows for increased anabolic demands, wherein glycolytic and tricarboxylic acid (TCA) cycle intermediates are shunted away for the synthesis of biological molecules required for cell growth and division. One of the key shunts is the exit of citrate from the mitochondria and the TCA cycle for the generation of cytosolic acetyl-coenzyme A that can be used for fatty acid and cholesterol biosynthesis. With the loss of mitochondrial citrate, cancer cells rely on the 'conditionally essential' amino acid glutamine (Q) as an anaplerotic carbon source for TCA cycle intermediates. Although Q deprivation causes G1 cell cycle arrest in non-transformed cells, its impact on the cancer cell cycle is not well characterized. We report here a correlation between bypass of the Q-dependent G1 checkpoint and cancer cells harboring K-Ras mutations. Instead of arresting in G1 in response to Q-deprivation, K-Ras-driven cancer cells arrest in either S- or G2/M-phase. Inhibition of K-Ras effector pathways was able to revert cells to G1 arrest upon Q deprivation. Blocking anaplerotic utilization of Q mimicked Q deprivation--causing S- and G2/M-phase arrest in K-Ras mutant cancer cells. Significantly, Q deprivation or suppression of anaplerotic Q utilization created synthetic lethality to the cell cycle phase-specific cytotoxic drugs, capecitabine and paclitaxel. These data suggest that disabling of the G1 Q checkpoint could represent a novel vulnerability of cancer cells harboring K-Ras and possibly other mutations that disable the Q-dependent checkpoint.

  19. Double-strand break repair and G2 block in Chinese hamster ovary cells and their radiosensitive mutants

    Weibezahn, K.F.; Lohrer, H.; Herrlich, P.

    1985-01-01

    Two X-ray-sensitive mutants of the CHO K1 cell line were examined for their cell-cycle progression after irradiation with γ-rays, and for their ability to rejoin double-strand breaks (DSBs) as detected by neutral filter elution. Both mutants were impaired in DSB rejoining and both were irreversibly blocked in the G 2 phase of the cell cycle as determined by cytofluorometry. From one mutant the authors have isolated several revertants. The revertants stem from genomic DNA transfection experiments and may have been caused by gene uptake. All revertants survived γ-irradiation as did the wild-type CHO line. One of them has been examined for its ability to rejoin DSBs and was found to be similar to the wild type. (Auth.)

  20. Double-strand break repair and G/sub 2/ block in Chinese hamster ovary cells and their radiosensitive mutants

    Weibezahn, K F; Lohrer, H; Herrlich, P [Kernforschungszentrum Karlsruhe G.m.b.H. (Germany, F.R.). Inst. fuer Genetik und Toxikologie

    1985-05-01

    Two X-ray-sensitive mutants of the CHO K1 cell line were examined for their cell-cycle progression after irradiation with ..gamma..-rays, and for their ability to rejoin double-strand breaks (DSBs) as detected by neutral filter elution. Both mutants were impaired in DSB rejoining and both were irreversibly blocked in the G/sub 2/ phase of the cell cycle as determined by cytofluorometry. From one mutant the authors have isolated several revertants. The revertants stem from genomic DNA transfection experiments and may have been caused by gene uptake. All revertants survived ..gamma..-irradiation as did the wild-type CHO line. One of them has been examined for its ability to rejoin DSBs and was found to be similar to the wild type.

  1. In silico-based identification of human α-enolase inhibitors to block cancer cell growth metabolically

    Lung, Jrhau; Chen, Kuan-Liang; Hung, Chien-Hui; Chen, Chih-Cheng; Hung, Ming-Szu; Lin, Yu-Ching; Wu, Ching-Yuan; Lee, Kuan-Der; Shih, Neng-Yao; Tsai, Ying Huang

    2017-01-01

    Unlimited growth of cancer cells requires an extensive nutrient supply. To meet this demand, cancer cells drastically upregulate glucose uptake and metabolism compared to normal cells. This difference has made the blocking of glycolysis a fascinating strategy to treat this malignant disease. α-enolase is not only one of the most upregulated glycolytic enzymes in cancer cells, but also associates with many cellular processes or conditions important to cancer cell survival, such as cell migration, invasion, and hypoxia. Targeting α-enolase could simultaneously disturb cancer cells in multiple ways and, therefore, is a good target for anticancer drug development. In the current study, more than 22 million chemical structures meeting the criteria of Lipinski’s rule of five from the ZINC database were docked to α-enolase by virtual screening. Twenty-four chemical structures with docking scores better than that of the enolase substrate, 2-phosphoglycerate, were further screened by the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties prediction. Four of them were classified as non-mutagenic, non-carcinogenic, and capable of oral administration where they showed steady interactions to α-enolase that were comparable, even superior, to the currently available inhibitors in molecular dynamics (MD) simulation. These compounds may be considered promising leads for further development of the α-enolase inhibitors and could help fight cancer metabolically. PMID:29180852

  2. Improved fill factor in inverted planar perovskite solar cells with zirconium acetate as the hole-and-ion-blocking layer.

    Zhang, Xuewen; Liang, Chunjun; Sun, Mengjie; Zhang, Huimin; Ji, Chao; Guo, Zebang; Xu, Yajun; Sun, Fulin; Song, Qi; He, Zhiqun

    2018-03-14

    Planar perovskite solar cells (PSCs) have gained great interest due to their low-temperature solution preparation and simple process. In inverted planar PSCs, an additional buffer layer is usually needed on the top of the PCBM electron-transport layer (ETL) to enhance the device performance. In this work, we used a new buffer layer, zirconium acetate (Zr(Ac) 4 ). The inclusion of the Zr(Ac) 4 buffer layer leads to the increase of FF from ∼68% to ∼79% and PCE from ∼14% to ∼17% in the planar PSCs. The UPS measurement indicates that the Zr(Ac) 4 layer has a low HOMO level of -8.2 eV, indicating that the buffer layer can act as a hole-blocking layer. Surface morphology and surface chemistry investigations reveal that the elements I, MA and Pb can diffuse across the PCBM ETL, damaging the device performance. The covering Zr(Ac) 4 molecules fill in the pinholes of the PCBM layer and effectively block the ions/molecules of the perovskite from diffusion across the ETL. The resulting more robust PCBM/Zr(Ac) 4 ETL leads to weaker ionic charge accumulation and lower diode leakage current. The double role of hole-and-ion blocking of the Zr(Ac) 4 layer explains the improved FF and PCE in the PSCs.

  3. Role of fine needle aspiration cytology and cell block in diagnosis of scar endometriosis: A case report

    Sashibhusan Dash

    2015-01-01

    Full Text Available Presence of endometrial glands and stroma in places other than the uterus is called endometriosis. It can be pelvic or extra-pelvic. Abdominal scar endometriosis is an extra-pelvic endometriosis that can occur after surgery involving the uterus. Post-caesarean section, scar endometriosis is a rare event. The diagnosis is frequently made only after excision of disease tissue. We present a case of post-caesarean section abdominal scar endometriosis presenting as a tumor on the abdominal wall, which was diagnosed by fine needle aspiration cytology and confirmed by cell block preparation.

  4. Inhibition of T cell proliferation by selective block of Ca(2+)-activated K(+) channels

    Jensen, B S; Odum, Niels; Jorgensen, N K

    1999-01-01

    cell activation and proliferation has been investigated by using various blockers of IK channels. The Ca(2+)-activated K(+) current in human T cells is shown by the whole-cell voltage-clamp technique to be highly sensitive to clotrimazole, charybdotoxin, and nitrendipine, but not to ketoconazole...

  5. Divalent ion block of inward rectifier current in human capillary endothelial cells and effects on resting membrane potential

    Jow, Flora; Numann, Randy

    1998-01-01

    Cultured human capillary endothelial cells (HCEC) contain a large inward rectifier current, IK(IR), that can be abolished by removing external K+ or by adding 50 μm Ba2+.We show that IK(IR) is responsible for maintaining the hyperpolarized potential (−60.6 ± 0.5 mV, n = 83) of HCEC. Blocking IK(IR) with 50 μm Ba2+ shifts the zero current level and depolarizes HCEC by 36.5 ± 1.3 mV (n = 4).Increasing external Ca2+ concentration ([Ca2+]o) from 0.5 to 7 mm reduces the magnitude of IK(IR) by 36.5 ± 2.3 % (n = 5) and depolarizes the cells by 10.33 ± 2.4 mV (n = 3), whereas decreasing [Ca2+]o from 1.8 to 0.5 mm increases the amplitude of IK(IR) by 6.9 ± 1.9 % (n = 4). The relationship between [Ca2+]o and the percentage block of IK(IR) gives a Kd value of 5.4 ± 0.6 mm at −120 mV.IK(IR) is also blocked by other divalent ions, with Ba2+ >> Sr2+ > Mg2+ > Mn2+= Ca2+, and the block of peak current at −120 mV being 85.3 ± 3.2 % (n = 5) for 50 μm Ba2+, 62.9 ± 2.2 % (n = 5) for 5 mm Sr2+, 40.7 ± 2.5 % (n = 9) for 5 mm Mg2+, 33.4 ± 2.1 % (n = 5) for 5 mm Mn2+ and 32.9 ± 2.1 % (n = 5) for 5 mm Ca2+.The voltage dependence of Sr2+ block of peak IK(IR) occurred with a Kd value of 1.0 ± 0.09 mm for −140 mV, 1.9 ± 0.16 mm for −130 mV, 3.1 ± 0.28 mm for −120 mV, 4.6 ± 0.34 mm for −110 mV and 6.4 ± 0.5 mm for −100 mV (n = 5), with a calculated electrical distance (δ) of 0.44 from the outside. PMID:9729622

  6. Quercetin suppresses HeLa cells by blocking PI3K/Akt pathway.

    Xiang, Tao; Fang, Yong; Wang, Shi-Xuan

    2014-10-01

    To explore the effect of quercetin on the proliferation and apoptosis of HeLa cells, HeLa cells were incubated with quercetin at different concentrations. Cell viability was evaluated by MTT assay, cell apoptosis was detected by Annexin-V/PI double labeled cytometry and DNA ladder assay. Cell cycle was flow cytometrically determined and the morphological changes of the cells were observed under a fluorescence microscope after Hoechst 33258 staining and the apoptosis-related proteins in the HeLa cells were assessed by Western blotting. The results showed that quercetin significantly inhibited the growth of HeLa cells and induced obvious apoptosis in vitro in a time- and dose-dependent manner. Moreover, quercetin induced apoptosis of HeLa cells in cell cycle-dependent manner because quercetin could induce arrest of HeLa cells at G0/G1 phase. Quercetin treatment down-regulated the expression of the PI3K and p-Akt. In addition, quercetin could down-regulate expression of bcl-2, up-regulate Bax, but exerted no effect on the overall expression of Akt. We are led to conclude that quercetin induces apoptosis via PI3k/Akt pathways, and quercetin has potential to be used as an anti-tumor agent against human cervix cancer.

  7. Influence of different TiO2 blocking films on the photovoltaic performance of perovskite solar cells

    Zhang, Chenxi; Luo, Yudan; Chen, Xiaohong; Ou-Yang, Wei; Chen, Yiwei; Sun, Zhuo; Huang, Sumei

    2016-12-01

    Organolead trihalide perovskite materials have been successfully used as light absorbers in efficient photovoltaic (PV) cells. Cell structures based on mesoscopic metal oxides and planar heterojunctions have already demonstrated very impressive and brisk advances, holding great potential to grow into a mature PV technology. High power conversion efficiency (PCE) values have been obtained from the mesoscopic configuration in which a few hundred nano-meter thick mesoporous scaffold (e.g. TiO2 or Al2O3) infiltrated by perovskite absorber was sandwiched between the electron and hole transport layers. A uniform and compact hole-blocking layer is necessary for high efficient perovskite-based thin film solar cells. In this study, we investigated the characteristics of TiO2 compact layer using various methods and its effects on the PV performance of perovskite solar cells. TiO2 compact layer was prepared by a sol-gel method based on titanium isopropoxide and HCl, spin-coating of titanium diisopropoxide bis (acetylacetonate), screen-printing of Dyesol's bocking layer titania paste, and a chemical bath deposition (CBD) technique via hydrolysis of TiCl4, respectively. The morphological and micro-structural properties of the formed compact TiO2 layers were characterized by scanning electronic microscopy and X-ray diffraction. The analyses of devices performance characteristics showed that surface morphologies of TiO2 compact films played a critical role in affecting the efficiencies. The nanocrystalline TiO2 film deposited via the CBD route acts as the most efficient hole-blocking layer and achieves the best performance in perovskite solar cells. The CBD-based TiO2 compact and dense layer offers a small series resistance and a large recombination resistance inside the device, and makes it possible to achieve a high power conversion efficiency of 12.80%.

  8. Hydrocortisone Increases the Vinblastine-Induced Chromosomal Damages in L929 Cells Investigated by the Micronucleus Assay on Cytokinesis-Blocked Binucleated Cells

    Tahere Ebrahimipour

    2017-03-01

    Full Text Available Background: Stress may cause damages to DNA or/and change the ability of the cells to overcome these damages. It may also cause irregularities in the cell cycle and induce abnormal cell divisions through glucocorticoid-dependent functions. The abnormal cell divisions, in turn, lead to chromosomal mal-segregation and aneuploidy. In this study, the effects of the stress hormone, hydrocortisone (HYD, were investigated on the induced chromosomal abnormalities by vinblastine (VIN during cell cycle in L929 cells. Methods: This work was performed in winter 2013 at Department of Biology, University of Ferdowsi, Mashhad, Iran. Cultured cells were divided into different groups including control, VIN-treated, HYD treated and VIN+HYD co-treated cells. The induced chromosomal damages were investigated by micronucleus assay in cytokinesis-blocked binucleated cells. Results: Although HYD by itself did not increase the micronuclei (Mn frequency, co-treatment of cells with VIN and HYD led to significant increase (P<0.05 in the frequency of Mn in comparison to control and VIN treated groups. Conclusion: Cells treated with stress hormone are more sensitive to damages induced by VIN. Therefore, stress may not directly result in genetic instability, it can increase the harmful effects associated with other genotoxic agents.

  9. Cytolethal distending toxin: a conserved bacterial genotoxin that blocks cell cycle progression, leading to apoptosis of a broad range of mammalian cell lineages.

    Jinadasa, Rasika N; Bloom, Stephen E; Weiss, Robert S; Duhamel, Gerald E

    2011-07-01

    Cytolethal distending toxin (CDT) is a heterotrimeric AB-type genotoxin produced by several clinically important Gram-negative mucocutaneous bacterial pathogens. Irrespective of the bacterial species of origin, CDT causes characteristic and irreversible cell cycle arrest and apoptosis in a broad range of cultured mammalian cell lineages. The active subunit CdtB has structural homology with the phosphodiesterase family of enzymes including mammalian DNase I, and alone is necessary and sufficient to account for cellular toxicity. Indeed, mammalian cells treated with CDT initiate a DNA damage response similar to that elicited by ionizing radiation-induced DNA double strand breaks resulting in cell cycle arrest and apoptosis. The mechanism of CDT-induced apoptosis remains incompletely understood, but appears to involve both p53-dependent and -independent pathways. While epithelial, endothelial and fibroblast cell lines respond to CDT by undergoing arrest of cell cycle progression resulting in nuclear and cytoplasmic distension that precedes apoptotic cell death, cells of haematopoietic origin display rapid apoptosis following a brief period of cell cycle arrest. In this review, the ecology of pathogens producing CDT, the molecular biology of bacterial CDT and the molecular mechanisms of CDT-induced cytotoxicity are critically appraised. Understanding the contribution of a broadly conserved bacterial genotoxin that blocks progression of the mammalian cell cycle, ultimately causing cell death, should assist with elucidating disease mechanisms for these important pathogens.

  10. Utility of bronchial lavage fluids for epithelial growth factor receptor mutation assay in lung cancer patients: Comparison between cell pellets, cell blocks and matching tissue specimens

    Asaka, Shiho; Yoshizawa, Akihiko; Nakata, Rie; Negishi, Tatsuya; Yamamoto, Hiroshi; Shiina, Takayuki; Shigeto, Shohei; Matsuda, Kazuyuki; Kobayashi, Yukihiro; Honda, Takayuki

    2018-01-01

    The detection of epidermal growth factor receptor (EGFR) mutations is necessary for the selection of suitable patients with non-small cell lung cancer (NSCLC) for treatment with EGFR tyrosine kinase inhibitors. Cytology specimens are known to be suitable for EGFR mutation detection, although tissue specimens should be prioritized; however, there are limited studies that examine the utility of bronchial lavage fluid (BLF) in mutation detection. The purpose of the present study was to investigate the utility of BLF specimens for the detection of EGFR mutations using a conventional quantitative EGFR polymerase chain reaction (PCR) assay. Initially, quantification cycle (Cq) values of cell pellets, cell-free supernatants and cell blocks obtained from three series of 1% EGFR mutation-positive lung cancer cell line samples were compared for mutation detection. In addition, PCR analysis of BLF specimens obtained from 77 consecutive NSCLC patients, detecting EGFR mutations was validated, and these results were compared with those for the corresponding formalin-fixed paraffin-embedded (FFPE) tissue specimens obtained by surgical resection or biopsy of 49 of these patients. The Cq values for mutation detection were significantly lower in the cell pellet group (average, 29.58) compared with the other groups, followed by those in cell-free supernatants (average, 34.15) and in cell blocks (average, 37.12) for all three series (P<0.05). Mutational status was successfully analyzed in 77 BLF specimens, and the results obtained were concordant with those of the 49 matching FFPE tissue specimens. Notably, EGFR mutations were even detected in 10 cytological specimens that contained insufficient tumor cells. EGFR mutation testing with BLF specimens is therefore a useful and reliable method, particularly when sufficient cancer cells are not obtained. PMID:29399190

  11. Bergmann glia and the recognition molecule CHL1 organize GABAergic axons and direct innervation of Purkinje cell dendrites.

    Fabrice Ango

    2008-04-01

    Full Text Available The geometric and subcellular organization of axon arbors distributes and regulates electrical signaling in neurons and networks, but the underlying mechanisms have remained elusive. In rodent cerebellar cortex, stellate interneurons elaborate characteristic axon arbors that selectively innervate Purkinje cell dendrites and likely regulate dendritic integration. We used GFP BAC transgenic reporter mice to examine the cellular processes and molecular mechanisms underlying the development of stellate cell axons and their innervation pattern. We show that stellate axons are organized and guided towards Purkinje cell dendrites by an intermediate scaffold of Bergmann glial (BG fibers. The L1 family immunoglobulin protein Close Homologue of L1 (CHL1 is localized to apical BG fibers and stellate cells during the development of stellate axon arbors. In the absence of CHL1, stellate axons deviate from BG fibers and show aberrant branching and orientation. Furthermore, synapse formation between aberrant stellate axons and Purkinje dendrites is reduced and cannot be maintained, leading to progressive atrophy of axon terminals. These results establish BG fibers as a guiding scaffold and CHL1 a molecular signal in the organization of stellate axon arbors and in directing their dendritic innervation.

  12. Nek1 silencing slows down DNA repair and blocks DNA damage-induced cell cycle arrest.

    Pelegrini, Alessandra Luíza; Moura, Dinara Jaqueline; Brenner, Bethânia Luise; Ledur, Pitia Flores; Maques, Gabriela Porto; Henriques, João Antônio Pegas; Saffi, Jenifer; Lenz, Guido

    2010-09-01

    Never in mitosis A (NIMA)-related kinases (Nek) are evolutionarily conserved proteins structurally related to the Aspergillus nidulans mitotic regulator NIMA. Nek1 is one of the 11 isoforms of the Neks identified in mammals. Different lines of evidence suggest the participation of Nek1 in response to DNA damage, which is also supported by the interaction of this kinase with proteins involved in DNA repair pathways and cell cycle regulation. In this report, we show that cells with Nek1 knockdown (KD) through stable RNA interference present a delay in DNA repair when treated with methyl-methanesulfonate (MMS), hydrogen peroxide (H(2)O(2)) and cisplatin (CPT). In particular, interstrand cross links induced by CPT take much longer to be resolved in Nek1 KD cells when compared to wild-type (WT) cells. In KD cells, phosphorylation of Chk1 in response to CPT was strongly reduced. While WT cells accumulate in G(2)/M after DNA damage with MMS and H(2)O(2), Nek1 KD cells do not arrest, suggesting that G(2)/M arrest induced by the DNA damage requires Nek1. Surprisingly, CPT-treated Nek1 KD cells arrest with a 4N DNA content similar to WT cells. This deregulation in cell cycle control in Nek1 KD cells leads to an increased sensitivity to genotoxic agents when compared to WT cells. These results suggest that Nek1 is involved in the beginning of the cellular response to genotoxic stress and plays an important role in preventing cell death induced by DNA damage.

  13. Engineering cell factories for producing building block chemicals for bio-polymer synthesis.

    Tsuge, Yota; Kawaguchi, Hideo; Sasaki, Kengo; Kondo, Akihiko

    2016-01-21

    Synthetic polymers are widely used in daily life. Due to increasing environmental concerns related to global warming and the depletion of oil reserves, the development of microbial-based fermentation processes for the production of polymer building block chemicals from renewable resources is desirable to replace current petroleum-based methods. To this end, strains that efficiently produce the target chemicals at high yields and productivity are needed. Recent advances in metabolic engineering have enabled the biosynthesis of polymer compounds at high yield and productivities by governing the carbon flux towards the target chemicals. Using these methods, microbial strains have been engineered to produce monomer chemicals for replacing traditional petroleum-derived aliphatic polymers. These developments also raise the possibility of microbial production of aromatic chemicals for synthesizing high-performance polymers with desirable properties, such as ultraviolet absorbance, high thermal resistance, and mechanical strength. In the present review, we summarize recent progress in metabolic engineering approaches to optimize microbial strains for producing building blocks to synthesize aliphatic and high-performance aromatic polymers.

  14. Band gap control using electric field of photonic gel cells fabricated with block copolymer and hydrogel.

    Lee, Sung Nam; Baek, Young Bin; Shin, Dong Myung

    2014-08-01

    Optical and electrical characteristics of the devices using photonic gel film and hydrogel electrolyte were studied. Poly(styrene-b-2-vinylpyridine) (PS-b-P2VP) lamellar film with alternating hydrophobic block and hydrophilic polyelectrolyte block polymers (52 kg/mol-b-57 kg/mol) were prepared for the photonic gel. Poly(isobutylene-co-maleic acid) sodium salts were prepared for the hydrogel. This hydrogel fiber is common water swelling material and it owned ions for a device has conductivity. Photonic gel and hydrogel was spin coating onto Indium-tin-oxide (ITO) glass for make electric fields. The reflectance maximum wavelength of photonic crystal device shifted from 538 nm and reached to 557 nm, 585 nm and 604 nm during 30 min voltage applying time. The bandwidth variation was very limited. Loss of electrolyte was much less with hydrogel compared to the pure water. We can control color of hydrogel used photonic device by electric field with reasonable time range under moderate electric field by applying 2 V between two facing electrodes.

  15. Influence of taurine and vitaiodurol on the development frequency of experimental stellate cataracts

    Fedorenko, B.S.; Kabachenko, A.N.; Vajnshtejn, E.S.; Yartsev, E.I.; Kolesnikov, Yu.A.

    1978-01-01

    Comparative investigations of medical efficiency of 4% solutions of taurine and vita-iodurol have been carried out using the model of experimental stellate cataract in mice. 140 male mice of CBAxC 57 BL 6 line with 14-16g mass were investigated. Animals of 3 groups (35 mice in each) were exposed to 300 rad dose gamma-radiation with Co 60 . Radiation intensity was 10 rad/s. The animals were examined before irradiation and each 4 weeks after irradiation. In 25 weeks after irradiation, when lenticular opacity was observed in more than half the mice, the animals of the first group were dropped in two eyes by 1 drop of 4% distilled water taurine solution during a month. Animals of the second group got instillations of vita-iodurol by the same method. The third group of animals was the irradiated control group. The fourth group of mice was used as the intact control group. Lenticular opacities developed were classified by the Christenberry and Furth method, suggested for evaluating stellate lenticular opacities in small laboratory animals. It was shown, that instillations of 4% taurine solution into animals with initial stellate cataract during a month result in reducing the frequency of lenticular opacities by 30%. Taurine in used concentration results in pronounced medical effect. Vita-iodurol hadn't any therapentic effect on the course of initial stellate catarat in mice

  16. Inhibition of Breast Cancer Progression by Blocking Heterocellular Contact Between Epithelial Cells and Fibroblasts

    2013-04-01

    tumor cells and fibroblasts in co-cultures.14 More recently, cell– polymer suspensions microinjected in collagen gels have been used to form 3D cell...Spaink, B. van de Water and E. H. J. Danen, Automated microinjection of cell- polymer suspensions in 3D ECM scaffolds for high-through- put quantitative...operation The microfluidic devices were fabricated using multilayered SU-8 molds and PDMS- based soft-lithography. In brief, three layers of SU8 -100

  17. Excessive amounts of mu heavy chain block B-cell development.

    Zhu, Lingqiao; Chang, Cheong-Hee; Dunnick, Wesley

    2011-09-01

    Antigen-independent B-cell development occurs in several stages that depend on the expression of Ig heavy and light chain. We identified a line of mice that lacked mature B cells in the spleen. This mouse line carried approximately 11 copies of a transgene of the murine heavy chain constant region locus, and B-lineage cells expressed excessive amounts of the intracellular μ heavy chain. B-cell development failed in the bone marrow at the pro/pre B-cell transition, and examination of other lines with various copy numbers of the same transgene suggested that deficiencies in B-cell development increased with increased transgene copy number. Expression of a transgenic (Tg) light chain along with the Tg μ heavy chain led to minimal rescue of B-cell development in the bone marrow and B cells in the spleen. There are several potential mechanisms for the death of pro/pre B cells as a consequence of excess heavy chain expression.

  18. Agarose cell block technique as a complementary method in the diagnosis of fungal osteomyelitis in a dog

    N.S. Rocha

    2012-04-01

    Full Text Available A 7-year-old Labrador Retriever female dog presenting left forelimb lameness for one day was admitted to the Veterinary Hospital (UNESP-Botucatu for clinical evaluation. Several tests, including blood and image analysis, microbiological culture and cytology of lytic areas of affected bone were made in order to establish a diagnosis. Serum biochemical profile revealed increased levels of liver enzymes, plasma globulin, creatine kinase (CK and calcium. Hemogram revealed anemia and leukocytosis; left humerus image analysis revealed an osteolytic lesion and cytology revealed a suppurative periostitis. Differential diagnosis was a nonspecific infectious inflammatory process or osteosarcoma. Since it was not possible to achieve a definitive diagnosis and there was a highly suspicious for an infectious agent, an agarose cell block of the bone marrow fine-needle aspiration was made. The cytological examination of cell block presented similar findings as described previously. However, additional stains including periodic acid-Schiff (PAS were positive for fungal hyphae, which rendered a diagnosis of fungal osteomyelitis due to Aspergillus spp. This case report illustrates an uncommon cause of osteomyelitis for breed that was diagnosed by an underused method in veterinary medicine.

  19. Inhibition of polymerases-alpha and -beta completely blocks DNA repair induced by UV irradiation in cultured mouse neuronal cells

    Licastro, F.; Sarafian, T.; Verity, A.M.; Walford, R.L.

    1985-01-01

    The effects of hydroxyurea, aphidicolin and dideoxythymidine on UV-induced DNA repair of mouse neuronal granular cells were studied. Aphidicolin, which is considered a specific inhibitor of polymerase-alpha, decreased spontaneous DNA synthesis by 93% and totally suppressed DNA repair. Dideoxythymidine, an inhibitor of polymerase-beta, was more potent in decreasing scheduled DNA synthesis than aphidicolin, and also completely blocked the UV-induced DNA repair. Hydroxyurea, a specific inhibitor of ribonucleotide reductase, inhibited scheduled DNA synthesis, but unscheduled DNA synthesis after UV irradiation was always well detectable. Our data suggest that in neuronal cells from 5 to 10 days old mice both polymerases-alpha and -beta are required for both DNA synthesis and repair. These two enzymes may act jointly in filling up the gaps along the DNA molecule and elongating the DNA chain

  20. HIF-1α inhibition blocks the cross talk between multiple myeloma plasma cells and tumor microenvironment

    Borsi, Enrica, E-mail: enrica.borsi2@unibo.it [Department of Experimental Diagnostic and Specialty Medicine (DIMES), “L. and A. Seràgnoli”, Bologna University School of Medicine, S. Orsola' s University Hospital (Italy); Perrone, Giulia [Fondazione IRCCS Istituto Nazionale dei Tumori, Hematology Department, Via Venezian 1, 20133 Milano (Italy); Terragna, Carolina; Martello, Marina; Zamagni, Elena; Tacchetti, Paola; Pantani, Lucia; Brioli, Annamaria; Dico, Angela Flores; Zannetti, Beatrice Anna; Rocchi, Serena; Cavo, Michele [Department of Experimental Diagnostic and Specialty Medicine (DIMES), “L. and A. Seràgnoli”, Bologna University School of Medicine, S. Orsola' s University Hospital (Italy)

    2014-11-01

    Multiple myeloma (MM) is a malignant disorder of post-germinal center B cells, characterized by the clonal proliferation of malignant plasma cells (PCs) within the bone marrow (BM). The reciprocal and complex interactions that take place between the different compartments of BM and the MM cells result in tumor growth, angiogenesis, bone disease, and drug resistance. Given the importance of the BM microenvironment in MM pathogenesis, we investigated the possible involvement of Hypoxia-Inducible transcription Factor-1 alpha (HIF-1α) in the PCs-bone marrow stromal cells interplay. To test this hypothesis, we used EZN-2968, a 3rd generation antisense oligonucleotide against HIF-1α, to inhibit HIF-1α functions. Herein, we provide evidence that the interaction between MM cells and BM stromal cells is drastically reduced upon HIF-1α down-modulation. Notably, we showed that upon exposure to HIF-1α inhibitor, neither the incubation with IL-6 nor the co-culture with BM stromal cells were able to revert the anti-proliferative effect induced by EZN-2968. Moreover, we observed a down-modulation of cytokine-induced signaling cascades and a reduction of MM cells adhesion capability to the extracellular matrix proteins in EZN-2968-treated samples. Taken together, these results strongly support the concept that HIF-1α plays a critical role in the interactions between bone BM cells and PCs in Multiple Myeloma. - Highlights: • HIF-1α inhibition induces a mild apoptotic cell death. • Down-modulation of cytokine-induced signaling cascades upon HIF-1α inhibition. • Reduced interaction between MM cells and BMSCs upon HIF-1α down-modulation. • Reduced PCs adhesion to the extracellular matrix protein induced by EZN-2968. • HIF-1α inhibition may be an attractive therapeutic strategy for Multiple Myeloma.

  1. Imidazolium-based Block Copolymers as Solid-State Separators for Alkaline Fuel Cells and Lithium Ion Batteries

    Nykaza, Jacob Richard

    In this study, polymerized ionic liquid (PIL) diblock copolymers were explored as solid-state polymer separators as an anion exchange membrane (AEM) for alkaline fuel cells AFCs and as a solid polymer electrolyte (SPE) for lithium-ion batteries. Polymerized ionic liquid (PIL) block copolymers are a distinct set of block copolymers that combine the properties of both ionic liquids (e.g., high conductivity, high electrochemical stability) and block copolymers (e.g., self-assembly into various nanostructures), which provides the opportunity to design highly conductive robust solid-state electrolytes that can be tuned for various applications including AFCs and lithium-ion batteries via simple anion exchange. A series of bromide conducting PIL diblock copolymers with an undecyl alkyl side chain between the polymer backbone and the imidazolium moiety were first synthesized at various compositions comprising of a PIL component and a non-ionic component. Synthesis was achieved by post-functionalization from its non-ionic precursor PIL diblock copolymer, which was synthesized via the reverse addition fragmentation chain transfer (RAFT) technique. This PIL diblock copolymer with long alkyl side chains resulted in flexible, transparent films with high mechanical strength and high bromide ion conductivity. The conductivity of the PIL diblock copolymer was three times higher than its analogous PIL homopolymer and an order of magnitude higher than a similar PIL diblock copolymer with shorter alkyl side chain length, which was due to the microphase separated morphology, more specifically, water/ion clusters within the PIL microdomains in the hydrated state. Due to the high conductivity and mechanical robustness of this novel PIL block copolymer, its application as both the ionomer and AEM in an AFC was investigated via anion exchange to hydroxide (OH-), where a maximum power density of 29.3 mW cm-1 (60 °C with H2/O2 at 25 psig (172 kPa) backpressure) was achieved. Rotating disk

  2. Pancreatic α-Cell Dysfunction in Type 2 Diabetes: Old Kids on the Block

    Jun Sung Moon

    2015-02-01

    Full Text Available Type 2 diabetes (T2D has been known as 'bi-hormonal disorder' since decades ago, the role of glucagon from α-cell has languished whereas β-cell taking center stage. Recently, numerous findings indicate that the defects of glucagon secretion get involve with development and exacerbation of hyperglycemia in T2D. Aberrant α-cell responses exhibit both fasting and postprandial states: hyperglucagonemia contributes to fasting hyperglycemia caused by inappropriate hepatic glucose production, and to postprandial hyperglycemia owing to blunted α-cell suppression. During hypoglycemia, insufficient counter-regulation response is also observed in advanced T2D. Though many debates still remained for exact mechanisms behind the dysregulation of α-cell in T2D, it is clear that the blockade of glucagon receptor or suppression of glucagon secretion from α-cell would be novel therapeutic targets for control of hyperglycemia. Whereas there have not been remarkable advances in developing new class of drugs, currently available glucagon-like peptide-1 and dipeptidyl peptidase-IV inhibitors could be options for treatment of hyperglucagonemia. In this review, we focus on α-cell dysfunction and therapeutic potentials of targeting α-cell in T2D.

  3. Chloroquine, an Endocytosis Blocking Agent, Inhibits Zika Virus Infection in Different Cell Models

    Rodrigo Delvecchio

    2016-11-01

    Full Text Available Zika virus (ZIKV infection in utero might lead to microcephaly and other congenital defects. Since no specific therapy is available thus far, there is an urgent need for the discovery of agents capable of inhibiting its viral replication and deleterious effects. Chloroquine is widely used as an antimalarial drug, anti-inflammatory agent, and it also shows antiviral activity against several viruses. Here we show that chloroquine exhibits antiviral activity against ZIKV in Vero cells, human brain microvascular endothelial cells, human neural stem cells, and mouse neurospheres. We demonstrate that chloroquine reduces the number of ZIKV-infected cells in vitro, and inhibits virus production and cell death promoted by ZIKV infection without cytotoxic effects. In addition, chloroquine treatment partially reveres morphological changes induced by ZIKV infection in mouse neurospheres.

  4. Chloroquine, an Endocytosis Blocking Agent, Inhibits Zika Virus Infection in Different Cell Models.

    Delvecchio, Rodrigo; Higa, Luiza M; Pezzuto, Paula; Valadão, Ana Luiza; Garcez, Patrícia P; Monteiro, Fábio L; Loiola, Erick C; Dias, André A; Silva, Fábio J M; Aliota, Matthew T; Caine, Elizabeth A; Osorio, Jorge E; Bellio, Maria; O'Connor, David H; Rehen, Stevens; de Aguiar, Renato Santana; Savarino, Andrea; Campanati, Loraine; Tanuri, Amilcar

    2016-11-29

    Zika virus (ZIKV) infection in utero might lead to microcephaly and other congenital defects. Since no specific therapy is available thus far, there is an urgent need for the discovery of agents capable of inhibiting its viral replication and deleterious effects. Chloroquine is widely used as an antimalarial drug, anti-inflammatory agent, and it also shows antiviral activity against several viruses. Here we show that chloroquine exhibits antiviral activity against ZIKV in Vero cells, human brain microvascular endothelial cells, human neural stem cells, and mouse neurospheres. We demonstrate that chloroquine reduces the number of ZIKV-infected cells in vitro, and inhibits virus production and cell death promoted by ZIKV infection without cytotoxic effects. In addition, chloroquine treatment partially reveres morphological changes induced by ZIKV infection in mouse neurospheres.

  5. Chloroquine, an Endocytosis Blocking Agent, Inhibits Zika Virus Infection in Different Cell Models

    Delvecchio, Rodrigo; Higa, Luiza M.; Pezzuto, Paula; Valadão, Ana Luiza; Garcez, Patrícia P.; Monteiro, Fábio L.; Loiola, Erick C.; Dias, André A.; Silva, Fábio J. M.; Aliota, Matthew T.; Caine, Elizabeth A.; Osorio, Jorge E.; Bellio, Maria; O’Connor, David H.; Rehen, Stevens; de Aguiar, Renato Santana; Savarino, Andrea; Campanati, Loraine; Tanuri, Amilcar

    2016-01-01

    Zika virus (ZIKV) infection in utero might lead to microcephaly and other congenital defects. Since no specific therapy is available thus far, there is an urgent need for the discovery of agents capable of inhibiting its viral replication and deleterious effects. Chloroquine is widely used as an antimalarial drug, anti-inflammatory agent, and it also shows antiviral activity against several viruses. Here we show that chloroquine exhibits antiviral activity against ZIKV in Vero cells, human brain microvascular endothelial cells, human neural stem cells, and mouse neurospheres. We demonstrate that chloroquine reduces the number of ZIKV-infected cells in vitro, and inhibits virus production and cell death promoted by ZIKV infection without cytotoxic effects. In addition, chloroquine treatment partially reveres morphological changes induced by ZIKV infection in mouse neurospheres. PMID:27916837

  6. FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

    Huang, Xiongfei; Zeng, Yeting; Wang, Xinrui; Ma, Xiaoxiao; Li, Qianqian; Li, Ningbo; Su, Hongying; Huang, Wendong

    2016-01-01

    The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth by rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.

  7. FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

    Huang, Xiongfei, E-mail: xiongfeihuang@hotmail.com [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou 350108, Fujian (China); Zeng, Yeting [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Wang, Xinrui [Department of Biochemistry and Molecular Biology, Fujian Medical University, Fuzhou 350108, Fujian (China); Ma, Xiaoxiao [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States); Li, Qianqian; Li, Ningbo; Su, Hongying [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Huang, Wendong [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States)

    2016-05-27

    The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth by rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.

  8. Rolling block mazes are PSPACE-complete

    Buchin, K.; Buchin, M.

    2012-01-01

    In a rolling block maze, one or more blocks lie on a rectangular board with square cells. In most mazes, the blocks have size k × m × n where k, m, n are integers that determine the size of the block in terms of units of the size of the board cells. The task of a rolling block maze is to roll a

  9. Immune response to a mammary adenocarcinoma. V. Sera from tumor-bearing rats contain multiple factors blocking cell-mediated cytotoxicity.

    Huber, S A; Lucas, Z J

    1978-12-01

    Sera from Fischer rats 3 to 13 days after i.p. injection of syngeneic 13762A mammary adenocarcinoma contain three factors specifically blocking cell-mediated cytotoxicity (CMC). The major blocking factor is a 160,000-dalton IgG that combines specifically to cytolytic lymphocytes but not to tumor cells or tumor antigen, and that is not dissociated after treatment with 8 M urea. The other factors have been putatively identified as tumor antigen (less than 70,000 daltons) and as soluble antigen-antibody complexes (greater than 200,000 daltons). Injecting the tumor antigen into tumor-free rats induced spleen cells specifically cytotoxic to the 13762A tumor and provided partial protection to challenge with live tumor cells. Treating soluble antigen-antibody complexes with 8 M urea decreased the size of the blocking activity from greater than 200,000 to less than 70,000 daltons. Although the IgG fraction dissociated from the complex did not block CMC, it did recombine with the tumor antigen fraction to transfer activity to the greater than 200,000-dalton fraction. In contrast, mixing tumor antigen with the IgG fraction that did block CMC did not alter the size of the blocking activities.

  10. BAFF promotes regulatory T-cell apoptosis and blocks cytokine production by activating B cells in primary biliary cirrhosis

    Zhang, Bo; Hu, Mintao [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China); Zhang, Peng [Nanjing Medical University, Nanjing, Jiangsu (China); Cao, Hong [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China); Wang, Yongzhen [The Second Hospital of Nanjing, Nanjing, Jiangsu (China); Wang, Zheng; Su, Tingting [Department of Hepatology, Wuxi Infectious Diseases Hospital, Wuxi, Jiangsu (China)

    2013-05-10

    Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology. A number of questions regarding its etiology are unclear. CD4+CD25+ regulatory T cells (Tregs) play a critical role in self-tolerance and, for unknown reasons, their relative number is reduced in PBC patients. B-cell-activating factor (BAFF) is a key survival factor during B-cell maturation and its concentration is increased in peripheral blood of PBC patients. It has been reported that activated B cells inhibit Treg cell proliferation and there are no BAFF receptors on Tregs. Therefore, we speculated that excessive BAFF may result in Treg reduction via B cells. To prove our hypothesis, we isolated Tregs and B cells from PBC and healthy donors. BAFF and IgM concentrations were then analyzed by ELISA and CD40, CD80, CD86, IL-10, and TGF-β expression in B cells and Tregs were measured by flow cytometry. BAFF up-regulated CD40, CD80, CD86, and IgM expression in B cells. However, BAFF had no direct effect on Treg cell apoptosis and cytokine secretion. Nonetheless, we observed that BAFF-activated B cells could induce Treg cell apoptosis and reduce IL-10 and TGF-β expression. We also showed that BAFF-activated CD4+ T cells had no effect on Treg apoptosis. Furthermore, we verified that bezafibrate, a hypolipidemic drug, can inhibit BAFF-induced Treg cell apoptosis. In conclusion, BAFF promotes Treg cell apoptosis and inhibits cytokine production by activating B cells in PBC patients. The results of this study suggest that inhibition of BAFF activation is a strategy for PBC treatment.

  11. Resveratrol blocks interleukin-18-EMMPRIN cross-regulation and smooth muscle cell migration

    Venkatesan, Balachandar; Valente, Anthony J.; Reddy, Venkatapuram Seenu; Siwik, Deborah A.; Chandrasekar, Bysani

    2009-01-01

    Vascular smooth muscle cell (SMC) migration is an important mechanism in atherogenesis and postangioplasty arterial remodeling. Previously, we demonstrated that the proinflammatory cytokine interleukin (IL)-18 is a potent inducer of SMC migration. Since extracellular matrix metalloproteinase inducer (EMMPRIN) stimulates ECM degradation and facilitates cell migration, we investigated whether IL-18 and EMMPRIN regulate each other's expression, whether their cross talk induces SMC migration, and...

  12. Cells bearing chromosome aberrations lacking one telomere are selectively blocked at the G2/M checkpoint

    Rodriguez, Pilar [Unitat de Biologia Cel.lular, Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Barquinero, Joan Francesc [Unitat d' Antropologia Biologica, Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Duran, Assumpta [Unitat de Biologia Cel.lular, Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Caballin, Maria Rosa [Unitat d' Antropologia Biologica, Departament de Biologia Animal, Biologia Vegetal i Ecologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Ribas, Montserrat [Servei de Radiofisica i Radioproteccio de l' Hospital de la Santa Creu i Sant Pau, 08025 Barcelona (Spain); Barrios, Leonardo, E-mail: Lleonard.Barrios@uab.cat [Unitat de Biologia Cel.lular, Departament de Biologia Cel.lular, Fisiologia i Immunologia, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain)

    2009-11-02

    Cell cycle checkpoints are part of the cellular mechanisms to maintain genomic integrity. After ionizing radiation exposure, the cells can show delay or arrest in their progression through the cell cycle, as well as an activation of the DNA repair machinery in order to reduce the damage. The G2/M checkpoint prevents G2 cells entering mitosis until the DNA damage has been reduced. The present study evaluates which G0 radiation-induced chromosome aberrations are negatively selected in the G2/M checkpoint. For this purpose, peripheral blood samples were irradiated at 1 and 3 Gy of {gamma}-rays, and lymphocytes were cultured for 48 h. Calyculin-A and Colcemid were used to analyze, in the same slide, cells in G2 and M. Chromosome spreads were consecutively analyzed by solid stain, pancentromeric and pantelomeric FISH and mFISH. The results show that the frequency of incomplete chromosome elements, those lacking a telomeric signal at one end, decreases abruptly from G2 to M. This indicates that cells with incomplete chromosome elements can progress from G0 to G2, but at the G2/M checkpoint suffer a strong negative selection.

  13. Cells bearing chromosome aberrations lacking one telomere are selectively blocked at the G2/M checkpoint

    Rodriguez, Pilar; Barquinero, Joan Francesc; Duran, Assumpta; Caballin, Maria Rosa; Ribas, Montserrat; Barrios, Leonardo

    2009-01-01

    Cell cycle checkpoints are part of the cellular mechanisms to maintain genomic integrity. After ionizing radiation exposure, the cells can show delay or arrest in their progression through the cell cycle, as well as an activation of the DNA repair machinery in order to reduce the damage. The G2/M checkpoint prevents G2 cells entering mitosis until the DNA damage has been reduced. The present study evaluates which G0 radiation-induced chromosome aberrations are negatively selected in the G2/M checkpoint. For this purpose, peripheral blood samples were irradiated at 1 and 3 Gy of γ-rays, and lymphocytes were cultured for 48 h. Calyculin-A and Colcemid were used to analyze, in the same slide, cells in G2 and M. Chromosome spreads were consecutively analyzed by solid stain, pancentromeric and pantelomeric FISH and mFISH. The results show that the frequency of incomplete chromosome elements, those lacking a telomeric signal at one end, decreases abruptly from G2 to M. This indicates that cells with incomplete chromosome elements can progress from G0 to G2, but at the G2/M checkpoint suffer a strong negative selection.

  14. miR-204 inhibits angiogenesis and promotes sensitivity to cetuximab in head and neck squamous cell carcinoma cells by blocking JAK2-STAT3 signaling.

    Wu, Qingwei; Zhao, Yingying; Wang, Peihua

    2018-03-01

    This study aims to investigate the roles of miR-204 in tumor angiogenesis of head and neck squamous cell carcinoma (HNSCC). Here, we found that miR-204 level was reduced in HNSCC tissues relative to that in normal adjacent tissues. Overexpression of miR-204 promoted tumor angiogenesis in HNSCC cells. Mechanistically, JAK2 was identified as a direct target of miR-204, and miR-204 overexpression blocked JAK2/STAT3 pathway. Moreover, overexpression of JAK2 attenuated the inhibition of miR-204 on tumor angiogenesis of HNSCC. Furthermore, overexpression of miR-204 enhanced sensitivity of cetuximab in HNSCC cells, this effect was attenuated by JAK2 overexpression too. Importantly, JAK2 expression was negatively correlated with miR-204 level in HNSCC tissues. Therefore, miR-204 acts as a tumor suppressor by blocking JAK2/STAT3 pathway in HNSCC cells. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  15. Cytokinesis-block micronucleus assay evolves into a 'cytome' assay of chromosomal instability, mitotic dysfunction and cell death

    Fenech, Michael

    2006-01-01

    The cytokinesis-block micronucleus (CBMN) assay was originally developed as an ideal system for measuring micronuclei (MNi) however it can also be used to measure nucleoplasmic bridges (NPBs), nuclear buds (NBUDs), cell death (necrosis or apoptosis) and nuclear division rate. Current evidence suggests that (a) NPBs originate from dicentric chromosomes in which the centromeres have been pulled to the opposite poles of the cell at anaphase and are therefore indicative of DNA mis-repair, chromosome rearrangement or telomere end-fusions, (b) NPBs may break to form MNi, (c) the nuclear budding process is the mechanism by which cells remove amplified and/or excess DNA and is therefore a marker of gene amplification and/or altered gene dosage, (d) cell cycle checkpoint defects result in micronucleus formation and (e) hypomethylation of DNA, induced nutritionally or by inhibition of DNA methyl transferase can lead to micronucleus formation either via chromosome loss or chromosome breakage. The strong correlation between micronucleus formation, nuclear budding and NPBs (r = 0.75-0.77, P < 0.001) induced by either folic acid deficiency or exposure to ionising radiation is supportive of the hypothesis that folic acid deficiency and/or ionising radiation cause genomic instability and gene amplification by the initiation of breakage-fusion-bridge cycles. In its comprehensive mode, the CBMN assay measures all cells including necrotic and apoptotic cells as well as number of nuclei per cell to provide a measure of cytotoxicity and mitotic activity. The CBMN assay has in fact evolved into a 'cytome' method for measuring comprehensively chromosomal instability phenotype and altered cellular viability caused by genetic defects and/or nutrional deficiencies and/or exogenous genotoxins thus opening up an exciting future for the use of this methodology in the emerging fields of nutrigenomics and toxicogenomics and their combinations

  16. Vpx overcomes a SAMHD1-independent block to HIV reverse transcription that is specific to resting CD4 T cells.

    Baldauf, Hanna-Mari; Stegmann, Lena; Schwarz, Sarah-Marie; Ambiel, Ina; Trotard, Maud; Martin, Margarethe; Burggraf, Manja; Lenzi, Gina M; Lejk, Helena; Pan, Xiaoyu; Fregoso, Oliver I; Lim, Efrem S; Abraham, Libin; Nguyen, Laura A; Rutsch, Frank; König, Renate; Kim, Baek; Emerman, Michael; Fackler, Oliver T; Keppler, Oliver T

    2017-03-07

    Early after entry into monocytes, macrophages, dendritic cells, and resting CD4 T cells, HIV encounters a block, limiting reverse transcription (RT) of the incoming viral RNA genome. In this context, dNTP triphosphohydrolase SAM domain and HD domain-containing protein 1 (SAMHD1) has been identified as a restriction factor, lowering the concentration of dNTP substrates to limit RT. The accessory lentiviral protein X (Vpx) proteins from the major simian immunodeficiency virus of rhesus macaque, sooty mangabey, and HIV-2 (SIVsmm/SIVmac/HIV-2) lineage packaged into virions target SAMHD1 for proteasomal degradation, increase intracellular dNTP pools, and facilitate HIV cDNA synthesis. We find that virion-packaged Vpx proteins from a second SIV lineage, SIV of red-capped mangabeys or mandrills (SIVrcm/mnd-2), increased HIV infection in resting CD4 T cells, but not in macrophages, and, unexpectedly, acted in the absence of SAMHD1 degradation, dNTP pool elevation, or changes in SAMHD1 phosphorylation. Vpx rcm/mnd-2 virion incorporation resulted in a dramatic increase of HIV-1 RT intermediates and viral cDNA in infected resting CD4 T cells. These analyses also revealed a barrier limiting HIV-1 infection of resting CD4 T cells at the level of nuclear import. Single amino acid changes in the SAMHD1-degrading Vpx mac239 allowed it to enhance early postentry steps in a Vpx rcm/mnd-2-like fashion. Moreover, Vpx enhanced HIV-1 infection of SAMHD1-deficient resting CD4 T cells of a patient with Aicardi-Goutières syndrome. These results indicate that Vpx, in addition to SAMHD1, overcomes a previously unappreciated restriction for lentiviruses at the level of RT that acts independently of dNTP concentrations and is specific to resting CD4 T cells.

  17. Epidural block

    ... page: //medlineplus.gov/ency/patientinstructions/000484.htm Epidural block - pregnancy To use the sharing features on this page, please enable JavaScript. An epidural block is a numbing medicine given by injection (shot) ...

  18. Ultrasound-Guided Phrenic Nerve Block for Intractable Hiccups following Placement of Esophageal Stent for Esophageal Squamous Cell Carcinoma.

    Arsanious, David; Khoury, Spiro; Martinez, Edgar; Nawras, Ali; Filatoff, Gregory; Ajabnoor, Hossam; Darr, Umar; Atallah, Joseph

    2016-05-01

    Hiccups are actions consisting of sudden contractions of the diaphragm and intercostals followed by a sudden inspiration and transient closure of the vocal cords. They are generally short lived and benign; however, in extreme and rare cases, such as esophageal carcinoma, they can become persistent or intractable, up to and involving significant pain, dramatically impacting the patient's quality of life. This case involves a 60-year-old man with a known history of squamous cell carcinoma of the esophagus. He was considered to have high surgical risk, and therefore he received palliative care through the use of fully covered metallic esophageal self-expandable stents due to a spontaneous perforated esophagus, after which he developed intractable hiccups and associated mediastinal pain. Conservative treatment, including baclofen, chlorpromazine, metoclopramide, and omeprazole, provided no relief for his symptoms. The patient was referred to pain management from gastroenterology for consultation on pain control. He ultimately received an ultrasound-guided left phrenic nerve block with bupivacaine and depomedrol, and 3 days later underwent the identical procedure on the right phrenic nerve. This led to complete resolution of his hiccups and associated mediastinal pain. At follow-up, 2 and 4 weeks after the left phrenic nerve block, the patient was found to maintain complete alleviation of the hiccups. Esophageal dilatation and/or phrenic or vagal afferent fiber irritation can be suspected in cases of intractable hiccups secondary to esophageal stenting. Regional anesthesia of the phrenic nerve through ultrasound guidance offers a long-term therapeutic option for intractable hiccups and associated mediastinal pain in selected patients with esophageal carcinoma after stent placement. Esophageal stent, esophageal stenting, intractable hiccups, intractable singultus, phrenic nerve block, phrenic nerve, ultrasound, palliative care, esophageal carcinoma.

  19. Pan-SRC kinase inhibition blocks B-cell receptor oncogenic signaling in non-Hodgkin lymphoma.

    Battistello, Elena; Katanayeva, Natalya; Dheilly, Elie; Tavernari, Daniele; Donaldson, Maria C; Bonsignore, Luca; Thome, Margot; Christie, Amanda L; Murakami, Mark A; Michielin, Olivier; Ciriello, Giovanni; Zoete, Vincent; Oricchio, Elisa

    2018-05-24

    In diffuse large B-cell lymphoma (DLBCL), activation of the B-cell receptor (BCR) promotes multiple oncogenic signals, which are essential for tumor proliferation. Inhibition of the Bruton's tyrosine kinase (BTK), a BCR downstream target, is therapeutically effective only in a subgroup of patients with DLBCL. Here, we used lymphoma cells isolated from patients with DLBCL to measure the effects of targeted therapies on BCR signaling and to anticipate response. In lymphomas resistant to BTK inhibition, we show that blocking BTK activity enhanced tumor dependencies from alternative oncogenic signals downstream of the BCR, converging on MYC upregulation. To completely ablate the activity of the BCR, we genetically and pharmacologically repressed the activity of the SRC kinases LYN, FYN, and BLK, which are responsible for the propagation of the BCR signal. Inhibition of these kinases strongly reduced tumor growth in xenografts and cell lines derived from patients with DLBCL independent of their molecular subtype, advancing the possibility to be relevant therapeutic targets in broad and diverse groups of DLBCL patients. © 2018 by The American Society of Hematology.

  20. ID4 promotes AR expression and blocks tumorigenicity of PC3 prostate cancer cells

    Komaragiri, Shravan Kumar; Bostanthirige, Dhanushka H.; Morton, Derrick J.; Patel, Divya; Joshi, Jugal; Upadhyay, Sunil; Chaudhary, Jaideep

    2016-01-01

    Deregulation of tumor suppressor genes is associated with tumorigenesis and the development of cancer. In prostate cancer, ID4 is epigenetically silenced and acts as a tumor suppressor. In normal prostate epithelial cells, ID4 collaborates with androgen receptor (AR) and p53 to exert its tumor suppressor activity. Previous studies have shown that ID4 promotes tumor suppressive function of AR whereas loss of ID4 results in tumor promoter activity of AR. Previous study from our lab showed that ectopic ID4 expression in DU145 attenuates proliferation and promotes AR expression suggesting that ID4 dependent AR activity is tumor suppressive. In this study, we examined the effect of ectopic expression of ID4 on highly malignant prostate cancer cell, PC3. Here we show that stable overexpression of ID4 in PC3 cells leads to increased apoptosis and decreased cell proliferation and migration. In addition, in vivo studies showed a decrease in tumor size and volume of ID4 overexpressing PC3 cells, in nude mice. At the molecular level, these changes were associated with increased androgen receptor (AR), p21, and AR dependent FKBP51 expression. At the mechanistic level, ID4 may regulate the expression or function of AR through specific but yet unknown AR co-regulators that may determine the final outcome of AR function. - Highlights: • ID4 expression induces AR expression in PC3 cells, which generally lack AR. • ID4 expression increased apoptosis and decreased cell proliferation and invasion. • Overexpression of ID4 reduces tumor growth of subcutaneous xenografts in vivo. • ID4 induces p21 and FKBP51 expression- co-factors of AR tumor suppressor activity.

  1. A Novel Peptide to Treat Oral Mucositis Blocks Endothelial and Epithelial Cell Apoptosis

    Wu Xiaoyan; Chen Peili [Department of Medicine, University of Chicago, Chicago, Illinois (United States); Sonis, Stephen T. [Division of Oral Medicine, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Biomodels, Watertown, Massachusetts (United States); Lingen, Mark W. [Department of Pathology, University of Chicago, Chicago, Illinois (United States); Berger, Ann [NephRx Corporation, Kalamazoo, Michigan (United States); Toback, F. Gary, E-mail: gtoback@medicine.bsd.uchicago.edu [Department of Medicine, University of Chicago, Chicago, Illinois (United States)

    2012-07-01

    Purpose: No effective agents currently exist to treat oral mucositis (OM) in patients receiving chemoradiation for the treatment of head-and-neck cancer. We identified a novel 21-amino acid peptide derived from antrum mucosal protein-18 that is cytoprotective, mitogenic, and motogenic in tissue culture and animal models of gastrointestinal epithelial cell injury. We examined whether administration of antrum mucosal protein peptide (AMP-p) could protect against and/or speed recovery from OM. Methods and Materials: OM was induced in established hamster models by a single dose of radiation, fractionated radiation, or fractionated radiation together with cisplatin to simulate conventional treatments of head-and-neck cancer. Results: Daily subcutaneous administration of AMP-p reduced the occurrence of ulceration and accelerated mucosal recovery in all three models. A delay in the onset of erythema after irradiation was observed, suggesting that a protective effect exists even before injury to mucosal epithelial cells occurs. To test this hypothesis, the effects of AMP-p on tumor necrosis factor-{alpha}-induced apoptosis were studied in an endothelial cell line (human dermal microvascular endothelial cells) as well as an epithelial cell line (human adult low-calcium, high-temperature keratinocytes; HaCaT) used to model the oral mucosa. AMP-p treatment, either before or after cell monolayers were exposed to tumor necrosis factor-{alpha}, protected against development of apoptosis in both cell types when assessed by annexin V and propidium iodide staining followed by flow cytometry or ligase-mediated polymerase chain reaction. Conclusions: These observations suggest that the ability of AMP-p to attenuate radiation-induced OM could be attributable, at least in part, to its antiapoptotic activity.

  2. ID4 promotes AR expression and blocks tumorigenicity of PC3 prostate cancer cells

    Komaragiri, Shravan Kumar; Bostanthirige, Dhanushka H.; Morton, Derrick J.; Patel, Divya; Joshi, Jugal; Upadhyay, Sunil; Chaudhary, Jaideep, E-mail: jchaudhary@cau.edu

    2016-09-09

    Deregulation of tumor suppressor genes is associated with tumorigenesis and the development of cancer. In prostate cancer, ID4 is epigenetically silenced and acts as a tumor suppressor. In normal prostate epithelial cells, ID4 collaborates with androgen receptor (AR) and p53 to exert its tumor suppressor activity. Previous studies have shown that ID4 promotes tumor suppressive function of AR whereas loss of ID4 results in tumor promoter activity of AR. Previous study from our lab showed that ectopic ID4 expression in DU145 attenuates proliferation and promotes AR expression suggesting that ID4 dependent AR activity is tumor suppressive. In this study, we examined the effect of ectopic expression of ID4 on highly malignant prostate cancer cell, PC3. Here we show that stable overexpression of ID4 in PC3 cells leads to increased apoptosis and decreased cell proliferation and migration. In addition, in vivo studies showed a decrease in tumor size and volume of ID4 overexpressing PC3 cells, in nude mice. At the molecular level, these changes were associated with increased androgen receptor (AR), p21, and AR dependent FKBP51 expression. At the mechanistic level, ID4 may regulate the expression or function of AR through specific but yet unknown AR co-regulators that may determine the final outcome of AR function. - Highlights: • ID4 expression induces AR expression in PC3 cells, which generally lack AR. • ID4 expression increased apoptosis and decreased cell proliferation and invasion. • Overexpression of ID4 reduces tumor growth of subcutaneous xenografts in vivo. • ID4 induces p21 and FKBP51 expression- co-factors of AR tumor suppressor activity.

  3. Differentiation of human stem cells is promoted by amphiphilic pluronic block copolymers

    Doğan A

    2012-09-01

    Full Text Available Aysegül Doğan,1 Mehmet E Yalvaç,1,2 Fikrettin Şahin,1 Alexander V Kabanov,3–5 András Palotás,6 Albert A Rizvanov71Department of Genetics and BioEngineering, College of Engineering and Architecture, Yeditepe University, Istanbul, Turkey; 2Center for Gene Therapy, Nationwide Children's Hospital, Ohio State University, Columbus, OH, USA; 3Center for Drug Delivery and Nanomedicine, 4Department of Pharmaceutical Sciences, College of Pharmacy, Durham Research Center, University of Nebraska Medical Center, Omaha, NE, USA; 5Laboratory of Chemical Design of Bio-nano-materials, Department of Chemistry, Mikhail V Lomonosov Moscow State University, Moscow, Russia; 6Asklepios-Med, Szeged, Hungary; 7Institute of Fundamental Medicine and Biology, Kazan (Volga Region Federal University, Kazan, RussiaAbstract: Stem cell usage provides novel avenues of tissue regeneration and therapeutics across disciplines. Apart from ethical considerations, the selection and amplification of donor stem cells remain a challenge. Various biopolymers with a wide range of properties have been used extensively to deliver biomolecules such as drugs, growth factors and nucleic acids, as well as to provide biomimetic surface for cellular adhesion. Using human tooth germ stem cells with high proliferation and transformation capacity, we have investigated a range of biopolymers to assess their potential for tissue engineering. Tolerability, toxicity, and their ability to direct differentiation were evaluated. The majority of pluronics, consisting of both hydrophilic and hydrophobic poly(ethylene oxide chains, either exerted cytotoxicity or had no significant effect on human tooth germ stem cells; whereas F68 increased the multi-potency of stem cells, and efficiently transformed them into osteogenic, chondrogenic, and adipogenic tissues. The data suggest that differentiation and maturation of stem cells can be promoted by selecting the appropriate mechanical and chemical

  4. Population Blocks.

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  5. Improved conductivity in dye-sensitised solar cells through block-copolymer confined TiO 2 crystallisation

    Guldin, Stefan

    2011-01-01

    Anatase TiO2 is typically a central component in high performance dye-sensitised solar cells (DSCs). This study demonstrates the benefits of high temperature synthesised mesoporous titania for the performance of solid-state DSCs. In contrast to earlier methods, the high temperature stability of mesoporous titania is enabled by the self-assembly of the amphiphilic block copolymer polyisoprene-block-polyethylene oxide (PI-b -PEO) which compartmentalises TiO2 crystallisation, preventing the collapse of porosity at temperatures up to 700 °C. The systematic study of the temperature dependence on DSC performance reveals a parameter trade-off: high temperature annealed anatase consisted of larger crystallites and had a higher conductivity, but this came at the expense of a reduced specific surface area. While the reduction in specific surface areas was found to be detrimental for liquid-electrolyte DSC performance, solid-state DSCs benefitted from the increased anatase conductivity and exhibited a performance increase by a factor of three. © 2011 The Royal Society of Chemistry.

  6. Free fatty acids induce ER stress and block antiviral activity of interferon alpha against hepatitis C virus in cell culture

    Gunduz Feyza

    2012-08-01

    Full Text Available Abstract Background Hepatic steatosis is recognized as a major risk factor for liver disease progression and impaired response to interferon based therapy in chronic hepatitis C (CHC patients. The mechanism of response to interferon-alpha (IFN-α therapy under the condition of hepatic steatosis is unexplored. We investigated the effect of hepatocellular steatosis on hepatitis C virus (HCV replication and IFN-α antiviral response in a cell culture model. Methods Sub-genomic replicon (S3-GFP and HCV infected Huh-7.5 cells were cultured with a mixture of saturated (palmitate and unsaturated (oleate long-chain free fatty acids (FFA. Intracytoplasmic fat accumulation in these cells was visualized by Nile red staining and electron microscopy then quantified by microfluorometry. The effect of FFA treatment on HCV replication and IFN-α antiviral response was measured by flow cytometric analysis, Renilla luciferase activity, and real-time RT-PCR. Results FFA treatment induced dose dependent hepatocellular steatosis and lipid droplet accumulation in the HCV replicon cells was confirmed by Nile red staining, microfluorometry, and by electron microscopy. Intracellular fat accumulation supports replication more in the persistently HCV infected culture than in the sub-genomic replicon (S3-GFP cell line. FFA treatment also partially blocked IFN-α response and viral clearance by reducing the phosphorylation of Stat1 and Stat2 dependent IFN-β promoter activation. We show that FFA treatment induces endoplasmic reticulum (ER stress response and down regulates the IFNAR1 chain of the type I IFN receptor leading to defective Jak-Stat signaling and impaired antiviral response. Conclusion These results suggest that intracellular fat accumulation in HCV cell culture induces ER stress, defective Jak-Stat signaling, and attenuates the antiviral response, thus providing an explanation to the clinical observation regarding how hepatocellular steatosis influences IFN

  7. Differential programming of p53-deficient embryonic cells during rotenone block

    Mitochondrial dysfunction has been implicated in chemical toxicities. The present study used an in vitro model to investigate the differential expression of metabolic pathways during cellular stress in p53- efficient embryonic fibroblasts compared to p53-deficient cells. These c...

  8. Autocrine CCL19 blocks dendritic cell migration toward weak gradients of CCL21

    Hansen, Morten; Met, Özcan; Larsen, Niels Bent

    2016-01-01

    Background aims. Maturation of dendritic cells (DCs) induces their homing from peripheral to lymphatic tissues guided by CCL21. However, in vitro matured human monocyte-derived DC cancer vaccines injected intradermally migrate poorly to lymph nodes (LNs). In vitro maturation protocols generate DCs...

  9. Cobalt ions inhibit negative feedback in the outer retina by blocking hemichannels on horizontal cells

    Fahrenfort, I.; Sjoerdsma, T.; Ripps, H.; Kamermans, M.

    2004-01-01

    In goldfish, negative feedback from horizontal cells to cones shifts the activation function of the Ca2+ current of the cones to more negative potentials. This shift increases the amount of Ca2+ flowing into the cones, resulting in an increase in glutamate release. The increased glutamate release

  10. Electrochemical Characterization of TiO 2 Blocking Layers for Dye-Sensitized Solar Cells

    Kavan, Ladislav; Té treault, Nicolas; Moehl, Thomas; Grä tzel, Michael

    2014-01-01

    Thin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from

  11. Sol–Gel Titanium Dioxide Blocking Layers for Dye- Sensitized Solar Cells: Electrochemical Characterization

    Kavan, Ladislav; Zukalová, Markéta; Vik, O.; Havlíček, D.

    2014-01-01

    Roč. 15, č. 6 (2014), s. 1056-1061 ISSN 1439-4235 R&D Projects: GA ČR GA13-07724S Institutional support: RVO:61388955 Keywords : TiO2 * electrochemistry * dye-sensitized solar cell Subject RIV: CG - Electrochemistry Impact factor: 3.419, year: 2014

  12. Rapid relief of block by mecamylamine of neuronal nicotinic acetylcholine receptors of rat chromaffin cells in vitro: an electrophysiological and modeling study.

    Giniatullin, R A; Sokolova, E M; Di Angelantonio, S; Skorinkin, A; Talantova, M V; Nistri, A

    2000-10-01

    The mechanism responsible for the blocking action of mecamylamine on neuronal nicotinic acetylcholine receptors (nAChRs) was studied on rat isolated chromaffin cells recorded under whole-cell patch clamp. Mecamylamine strongly depressed (IC(50) = 0.34 microM) inward currents elicited by short pulses of nicotine, an effect slowly reversible on wash. The mecamylamine block was voltage-dependent and promptly relieved by a protocol combining membrane depolarization with a nicotine pulse. Either depolarization or nicotine pulses were insufficient per se to elicit block relief. Block relief was transient; response depression returned in a use-dependent manner. Exposure to mecamylamine failed to block nAChRs if they were not activated by nicotine or if they were activated at positive membrane potentials. These data suggest that mecamylamine could not interact with receptors either at rest or at depolarized level. Other nicotinic antagonists like dihydro-beta-erythroidine or tubocurarine did not share this action of mecamylamine although proadifen partly mimicked it. Mecamylamine is suggested to penetrate and block open nAChRs that would subsequently close and trap this antagonist. Computer modeling indicated that the mechanism of mecamylamine blocking action could be described by assuming that 1) mecamylamine-blocked receptors possessed a much slower, voltage-dependent isomerization rate, 2) the rate constant for mecamylamine unbinding was large and poorly voltage dependent. Hence, channel reopening plus depolarization allowed mecamylamine escape and block relief. In the presence of mecamylamine, therefore, nAChRs acquire the new property of operating as coincidence detectors for concomitant changes in membrane potential and receptor occupancy.

  13. The V protein of Tioman virus is incapable of blocking type I interferon signaling in human cells.

    Grégory Caignard

    Full Text Available The capacity of a virus to cross species barriers is determined by the development of bona fide interactions with cellular components of new hosts, and in particular its ability to block IFN-α/β antiviral signaling. Tioman virus (TioV, a close relative of mumps virus (MuV, has been isolated in giant fruit bats in Southeast Asia. Nipah and Hendra viruses, which are present in the same bat colonies, are highly pathogenic in human. Despite serological evidences of close contacts between TioV and human populations, whether TioV is associated to some human pathology remains undetermined. Here we show that in contrast to the V protein of MuV, the V protein of TioV (TioV-V hardly interacts with human STAT2, does not degrade STAT1, and cannot block IFN-α/β signaling in human cells. In contrast, TioV-V properly binds to human STAT3 and MDA5, and thus interferes with IL-6 signaling and IFN-β promoter induction in human cells. Because STAT2 binding was previously identified as a host restriction factor for some Paramyxoviridae, we established STAT2 sequence from giant fruit bats, and binding to TioV-V was tested. Surprisingly, TioV-V interaction with STAT2 from giant fruit bats is also extremely weak and barely detectable. Altogether, our observations question the capacity of TioV to appropriately control IFN-α/β signaling in both human and giant fruit bats that are considered as its natural host.

  14. The state of cell block variation and satisfaction in the era of molecular diagnostics and personalized medicine

    John P Crapanzano

    2014-01-01

    Full Text Available Background: In the recent past, algorithms and recommendations to standardize the morphological, immunohistochemical and molecular classification of lung cancers on cytology specimens have been proposed, and several organizations have recommended cell blocks (CBs as the preferred modality for molecular testing. Based on the literature, there are several different techniques available for CB preparation-suggesting that there is no standard. The aim of this study was to conduct a survey of CB preparation techniques utilized in various practice settings and analyze current issues, if any. Materials and Methods: A single E-mail with a link to an electronic survey was distributed to members of the American Society of Cytopathology and other pathologists. Questions pertaining to the participants′ practice setting and CBs-volume, method, quality and satisfaction-were included. Results: Of 95 respondents, 90/95 (94% completed the survey and comprise the study group. Most participants practice in a community hospital/private practice (44% or academic center (41%. On average, 14 CBs (range 0-50; median 10 are prepared by a laboratory daily. Over 10 methods are utilized: Plasma thrombin (33%, HistoGel (27%, Cellient automated cell block system (8% and others (31% respectively. Forty of 90 (44% respondents are either unsatisfied or sometimes satisfied with their CB quality, with low-cellular yield being the leading cause of dissatisfaction. There was no statistical significance between the three most common CB preparation methods and satisfaction with quality. Discussion: Many are dissatisfied with their current method of CB preparation, and there is no consistent method to prepare CBs. In today′s era of personalized medicine with an increasing array of molecular tests being applied to cytological specimens, there is a need for a standardized protocol for CB optimization to enhance cellularity.

  15. The state of cell block variation and satisfaction in the era of molecular diagnostics and personalized medicine.

    Crapanzano, John P; Heymann, Jonas J; Monaco, Sara; Nassar, Aziza; Saqi, Anjali

    2014-01-01

    In the recent past, algorithms and recommendations to standardize the morphological, immunohistochemical and molecular classification of lung cancers on cytology specimens have been proposed, and several organizations have recommended cell blocks (CBs) as the preferred modality for molecular testing. Based on the literature, there are several different techniques available for CB preparation-suggesting that there is no standard. The aim of this study was to conduct a survey of CB preparation techniques utilized in various practice settings and analyze current issues, if any. A single E-mail with a link to an electronic survey was distributed to members of the American Society of Cytopathology and other pathologists. Questions pertaining to the participants' practice setting and CBs-volume, method, quality and satisfaction-were included. Of 95 respondents, 90/95 (94%) completed the survey and comprise the study group. Most participants practice in a community hospital/private practice (44%) or academic center (41%). On average, 14 CBs (range 0-50; median 10) are prepared by a laboratory daily. Over 10 methods are utilized: Plasma thrombin (33%), HistoGel (27%), Cellient automated cell block system (8%) and others (31%) respectively. Forty of 90 (44%) respondents are either unsatisfied or sometimes satisfied with their CB quality, with low-cellular yield being the leading cause of dissatisfaction. There was no statistical significance between the three most common CB preparation methods and satisfaction with quality. Many are dissatisfied with their current method of CB preparation, and there is no consistent method to prepare CBs. In today's era of personalized medicine with an increasing array of molecular tests being applied to cytological specimens, there is a need for a standardized protocol for CB optimization to enhance cellularity.

  16. MUC1 in human milk blocks transmission of human immunodeficiency virus from dendritic cells to T cells

    Saeland, E.; Jong, de M.A.W.P.; Nabatov, A.; Kalay, H.; Kooijk, van Y.; Geijtenbeek, T.B.H.

    2009-01-01

    Mother-to-child transmission of human immunodeficiency virus-1 (HIV-1) occurs frequently via breast-feeding. HIV-1 targets DC-SIGN+ dendritic cells (DCs) in mucosal areas that allow efficient transmission of the virus to T cells. Here, we demonstrate that the epithelial mucin MUC1, abundant in milk,

  17. Block copolymer based composition and morphology control in nanostructured hybrid materials for energy conversion and storage: solar cells, batteries, and fuel cells

    Orilall, M. Christopher

    2011-01-01

    The development of energy conversion and storage devices is at the forefront of research geared towards a sustainable future. However, there are numerous issues that prevent the widespread use of these technologies including cost, performance and durability. These limitations can be directly related to the materials used. In particular, the design and fabrication of nanostructured hybrid materials is expected to provide breakthroughs for the advancement of these technologies. This tutorial review will highlight block copolymers as an emerging and powerful yet affordable tool to structure-direct such nanomaterials with precise control over structural dimensions, composition and spatial arrangement of materials in composites. After providing an introduction to materials design and current limitations, the review will highlight some of the most recent examples of block copolymer structure-directed nanomaterials for photovoltaics, batteries and fuel cells. In each case insights are provided into the various underlying fundamental chemical, thermodynamic and kinetic formation principles enabling general and relatively inexpensive wet-polymer chemistry methodologies for the efficient creation of multiscale functional materials. Examples include nanostructured ceramics, ceramic-carbon composites, ceramic-carbon-metal composites and metals with morphologies ranging from hexagonally arranged cylinders to three-dimensional bi-continuous cubic networks. The review ends with an outlook towards the synthesis of multicomponent and hierarchical multifunctional hybrid materials with different nano-architectures from self-assembly of higher order blocked macromolecules which may ultimately pave the way for the further development of energy conversion and storage devices. © 2011 The Royal Society of Chemistry.

  18. Block copolymer based composition and morphology control in nanostructured hybrid materials for energy conversion and storage: solar cells, batteries, and fuel cells.

    Orilall, M Christopher; Wiesner, Ulrich

    2011-02-01

    The development of energy conversion and storage devices is at the forefront of research geared towards a sustainable future. However, there are numerous issues that prevent the widespread use of these technologies including cost, performance and durability. These limitations can be directly related to the materials used. In particular, the design and fabrication of nanostructured hybrid materials is expected to provide breakthroughs for the advancement of these technologies. This tutorial review will highlight block copolymers as an emerging and powerful yet affordable tool to structure-direct such nanomaterials with precise control over structural dimensions, composition and spatial arrangement of materials in composites. After providing an introduction to materials design and current limitations, the review will highlight some of the most recent examples of block copolymer structure-directed nanomaterials for photovoltaics, batteries and fuel cells. In each case insights are provided into the various underlying fundamental chemical, thermodynamic and kinetic formation principles enabling general and relatively inexpensive wet-polymer chemistry methodologies for the efficient creation of multiscale functional materials. Examples include nanostructured ceramics, ceramic-carbon composites, ceramic-carbon-metal composites and metals with morphologies ranging from hexagonally arranged cylinders to three-dimensional bi-continuous cubic networks. The review ends with an outlook towards the synthesis of multicomponent and hierarchical multifunctional hybrid materials with different nano-architectures from self-assembly of higher order blocked macromolecules which may ultimately pave the way for the further development of energy conversion and storage devices.

  19. Improving the photovoltaic parameters in Quantum dot sensitized solar cells through employment of chemically deposited compact titania blocking layer

    Rajendra Prasad, M.B., E-mail: rajendraprasadmb75@gmail.com [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India); National Defence Academy, Khadakwasla, Pune, 411023 (India); Kadam, Vishal [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India); Joo, Oh-Shim [Korea Institute of Science and Technology, PO Box No. 131, Chongryang, Seoul, 130-650 (Korea, Republic of); Pathan, Habib M. [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India)

    2017-06-15

    Incorporation of compact blocking layer at the Transparent Conducting Oxide (TCO)/Electrolyte interface is an effective method to improve the device performance in QDSSC through mitigation of electron recombinations at this interface. This paper reports the most facile and cost effective method of depositing a rutile titania Compact Layer (CL) over Fluorine doped Tin Oxide (FTO) substrate and its application in titania based CdS QD sensitized solar cells. The deposited compact layers are characterized to study their structural, optical, morphological and electrochemical properties using X-Ray Diffractometry, UV–Visible spectroscopy, Scanning electron microscopy, Cyclic Voltammetry and Contact Angle measurements. Sandwich solar cells are fabricated using these CL based electrodes and characterized using Electrochemical Impedance Spectroscopy, Open Circuit Voltage Decay and J-V characteristics. The CL incorporated CdS QDSSC showed more than 100% increase in the photoconversion efficiency (1.68%) as compared to its bare FTO counterpart (0.73%) proving the efficacy of employed strategy. - Highlights: • Deposited titania compact layer by a facile room temperature chemical bath method. • Employed this to mitigate back electron transfer at TCO/Electrolyte interface. • Compact layer incorporation has improved the solar cell performance by 130%.

  20. Total glucosides of paeony attenuated functional maturation of dendritic cells via blocking TLR4/5 signaling in vivo.

    Zhou, Zhou; Lin, Jinpiao; Huo, Rongfen; Huang, Wenkang; Zhang, Jian; Wang, Li; Sun, Yue; Shen, Baihua; Li, Ningli

    2012-11-01

    It is well known that dendritic cells (DCs) play a critical role in the initiation and development of an immune response. Inhibitory effect on DC maturation alters immune-mediated inflammatory reaction in vivo. Total glucosides of paeony (TGP) are active compounds extracted from the roots of Paeonia lactiflora and have been widely used to ameliorate inflammation in therapy for autoimmune diseases. However, whether TGP act on DC maturation remains unknown. In this study, we investigated the effect of TGP on DC maturation in ovalbumin (OVA) immunized mice. Ear inflammation was inhibited by TGP (150 mgkg(-1), i.p.×11 days) obviously. The antigen presenting capacity of DC derived from TGP-treated mice was arrested. Meanwhile, OVA specific T cell proliferation was inhibited. In addition, we found that maturation of DCs was decreased by TGP treatment. Furthermore, OVA specific T cell proliferation was rescued by the adoptive transfer of mature DCs (mDCs) into TGP treated OVA-challenged mice. The research on the mechanism showed that TGP significantly inhibited activation of TLR4/5 singling. All these results demonstrated that TGP inhibited DC maturation and function by selectively blocking TLR4/5 activation in vivo, which in turn leads to reduce immune-mediated inflammation in vivo, adding a novel mechanism and therapeutic target of TGP for inflammatory and autoimmune disease treatment. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Pan-Bcl-2 inhibitor obatoclax delays cell cycle progression and blocks migration of colorectal cancer cells.

    Bruno Christian Koehler

    Full Text Available Despite the fact that new treatment regimes have improved overall survival of patients challenged by colorectal cancer (CRC, prognosis in the metastatic situation is still restricted. The Bcl-2 family of proteins has been identified as promising anti cancer drug target. Even though small molecules targeting Bcl-2 proteins are in clinical trials, little is known regarding their effects on CRC. The aim of this study was to preclinically investigate the value of ABT-737 and Obatoclax as anticancer drugs for CRC treatment. The effects of the BH3-mimetics ABT-737 and Obatoclax on CRC cells were assessed using viability and apoptosis assays. Wound healing migration and boyden chamber invasion assays were applied. 3-dimensional cell cultures were used for long term assessment of invasion and proliferation. Clinically relevant concentrations of pan-Bcl-2 inhibitor Obatoclax did not induce cell death. In contrast, the BH3-mimetic ABT-737 induced apoptosis in a dose dependent manner. Obatoclax caused a cell line specific slowdown of CRC cell growth. Furthermore, Obatoclax, but not ABT-737, recovered E-Cadherin expression and led to impaired migration and invasion of CRC cells. The proliferative capacity and invasiveness of CRC cells was strikingly inhibited by low dose Obatoclax in long term 3-dimensional cell cultures. Obatoclax, but not ABT-737, caused a G1-phase arrest accompanied by a downregulation of Cyclin D1 and upregulation of p27 and p21. Overexpression of Mcl-1, Bcl-xL or Bcl-2 reversed the inhibitory effect of Obatoclax on migration but failed to restore the proliferative capacity of Obatoclax-treated CRC cells. The data presented indicate broad and multifaceted antitumor effects of the pan-Bcl-2 inhibitor Obatoclax on CRC cells. In contrast to ABT-737, Obatoclax inhibited migration, invasion and proliferation in sublethal doses. In summary, this study recommends pan-Bcl-2 inhibition as a promising approach for clinical trials in CRC.

  2. PD-1 blocks lytic granule polarization with concomitant impairment of integrin outside-in signaling in the natural killer cell immunological synapse.

    Huang, Yu; Chen, Zhiying; Jang, Joon Hee; Baig, Mirza S; Bertolet, Grant; Schroeder, Casey; Huang, Shengjian; Hu, Qian; Zhao, Yong; Lewis, Dorothy E; Qin, Lidong; Zhu, Michael Xi; Liu, Dongfang

    2018-04-18

    The inhibitory receptor programmed cell death protein 1 (PD-1) is upregulated on a variety of immune cells, including natural killer (NK) cells, during chronic viral infection and tumorigenesis. Blockade of PD-1 or its ligands produces durable clinical responses with tolerable side effects in patients with a broad spectrum of cancers. However, the underlying molecular mechanisms of how PD-1 regulates NK cell function remain poorly characterized. We sought to determine the effect of PD-1 signaling on NK cells. PD-1 was overexpressed in CD16-KHYG-1 (a human NK cell line with both antibody-dependent cellular cytotoxicity through CD16 and natural cytotoxicity through NKG2D) cells and stimulated by exposing the cells to NK-sensitive target cells expressing programmed death ligand 1 (PD-L1). PD-1 engagement by PD-L1 specifically blocked NK cell-mediated cytotoxicity without interfering with the conjugation between NK cells and target cells. Further examination showed that PD-1 signaling blocked lytic granule polarization in NK cells, which was accompanied by failure of integrin-linked kinase, a key molecule in the integrin outside-in signaling pathway, to accumulate in the immunological synapse after NK-target cell conjugation. Our results suggest that NK cell cytotoxicity is inhibited by PD-1 engagement, which blocks lytic granule polarization to the NK cell immunological synapse with concomitant impairment of integrin outside-in signaling. This study provides novel mechanistic insights into how PD-1 inhibition disrupts NK cell function. Copyright © 2018 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  3. Reversing resistance to vascular-disrupting agents by blocking late mobilization of circulating endothelial progenitor cells.

    Taylor, Melissa; Billiot, Fanny; Marty, Virginie; Rouffiac, Valérie; Cohen, Patrick; Tournay, Elodie; Opolon, Paule; Louache, Fawzia; Vassal, Gilles; Laplace-Builhé, Corinne; Vielh, Philippe; Soria, Jean-Charles; Farace, Françoise

    2012-05-01

    The prevailing concept is that immediate mobilization of bone marrow-derived circulating endothelial progenitor cells (CEP) is a key mechanism mediating tumor resistance to vascular-disrupting agents (VDA). Here, we show that administration of VDA to tumor-bearing mice induces 2 distinct peaks in CEPs: an early, unspecific CEP efflux followed by a late yet more dramatic tumor-specific CEP burst that infiltrates tumors and is recruited to vessels. Combination with antiangiogenic drugs could not disrupt the early peak but completely abrogated the late VDA-induced CEP burst, blunted bone marrow-derived cell recruitment to tumors, and resulted in striking antitumor efficacy, indicating that the late CEP burst might be crucial to tumor recovery after VDA therapy. CEP and circulating endothelial cell kinetics in VDA-treated patients with cancer were remarkably consistent with our preclinical data. These findings expand the current understanding of vasculogenic "rebounds" that may be targeted to improve VDA-based strategies. Our findings suggest that resistance to VDA therapy may be strongly mediated by late, rather than early, tumor-specific recruitment of CEPs, the suppression of which resulted in increased VDA-mediated antitumor efficacy. VDA-based therapy might thus be significantly enhanced by combination strategies targeting late CEP mobilization. © 2012 AACR

  4. Sorafenib inhibits tumor growth and vascularization of rhabdomyosarcoma cells by blocking IGF-1R-mediated signaling

    Wessen Maruwge

    2008-11-01

    Full Text Available Wessen Maruwge1, Pádraig D’Arcy1, Annika Folin1,2, Slavica Brnjic1, Johan Wejde1, Anthony Davis1, Fredrik Erlandsson3, Jonas Bergh1,2, Bertha Brodin11Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden; 2Radiumhemmet, Karolinska University Hospital, Stockholm, Sweden; 3Bayer Pharmaceutical Corporation, SwedenAbstract: The growth of many soft tissue sarcomas is dependent on aberrant growth factor signaling, which promotes their proliferation and motility. With this in mind, we evaluated the effect of sorafenib, a receptor tyrosine kinase inhibitor, on cell growth and apoptosis in sarcoma cell lines of various histological subtypes. We found that sorafenib effectively inhibited cell proliferation in rhabdomyosarcoma, synovial sarcoma and Ewing’s sarcoma with IC50 values <5 µM. Sorafenib effectively induced growth arrest in rhabdomyosarcoma cells, which was concurrent with inhibition of Akt and Erk signaling. Studies of ligand-induced phosphorylation of Erk and Akt in rhabdomyosarcoma cells showed that insulin-like growth factor-1 is a potent activator, which can be blocked by treatment with sorafenib. In vivo sorafenib treatment of rhabdomyosarcoma xenografts had a significant inhibitory effect on tumor growth, which was associated with inhibited vascularization and enhanced necrosis in the adjacent tumor stroma. Our results demonstrate that in vitro and in vivo growth of rhabdomyosarcoma can be suppressed by treatment with sorafenib, and suggests the possibilities of using sorafenib as a potential adjuvant therapy for the treatment of rhabdomyosarcoma.Keywords: soft tissue sarcoma, kinase inhibitors, targeted therapy, vascularization

  5. Extra-virgin olive oil phenols block cell cycle progression and modulate chemotherapeutic toxicity in bladder cancer cells

    Coccia, Andrea; Mosca, Luciana; Puca, Rosa; Mangino, Giorgio; Rossi, Alessandro; Lendaro, Eugenio

    2016-01-01

    Epidemiological data indicate that the daily consumption of extra-virgin olive oil (EVOO), a common dietary habit of the Mediterranean area, lowers the incidence of certain types of cancer, in particular bladder neoplasm. The aim of the present study was to evaluate the antiproliferative activity of polyphenols extracted from EVOO on bladder cancer (BCa), and to clarify the biological mechanisms that trigger cell death. Furthermore, we also evaluated the ability of low doses of extra-virgin olive oil extract (EVOOE) to modulate the in vitro activity of paclitaxel or mitomycin, two antineoplastic drugs used in the management of different types of cancer. Our results showed that EVOOE significantly inhibited the proliferation and clonogenic ability of T24 and 5637 BCa cells in a dose-dependent manner. Furthermore, cell cycle analysis after EVOOE treatment showed a marked growth arrest prior to mitosis in the G2/M phase for both cell lines, with the subsequent induction of apoptosis only in the T24 cells. Notably, simultaneous treatment of mitomycin C and EVOOE reduced the drug cytotoxicity due to inhibition of ROS production. Conversely, the co-treatment of T24 cells with paclitaxel and the polyphenol extract strongly increased the apoptotic cell death at each tested concentration compared to paclitaxel alone. Our results support the epidemiological evidence indicating that olive oil consumption exerts health benefits and may represent a starting point for the development of new anticancer strategies. PMID:27748855

  6. Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells

    Krýsová, Hana; Krýsa, J.; Kavan, Ladislav

    2018-01-01

    Roč. 9, APR 2018 (2018), s. 1135-1145 ISSN 2190-4286 R&D Projects: GA ČR GA17-20008S; GA ČR(CZ) GA18-08959s Institutional support: RVO:61388955 Keywords : blocking films * FTO * solar cells Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 3.127, year: 2016

  7. Blocking hepatic metastases of colon cancer cells using an shRNA against Rac1 delivered by activatable cell-penetrating peptide.

    Bao, Ying; Guo, Huihui; Lu, Yongliang; Feng, Wenming; Sun, Xinrong; Tang, Chengwu; Wang, Xiang; Shen, Mo

    2016-11-22

    Hepatic metastasis is one of the critical progressions of colon cancer. Blocking this process is key to prolonging survival time in cancer patients. Studies on activatable cell-penetrating peptides (dtACPPs) have demonstrated their potential as gene carriers. It showed high tumor cell-targeting specificity and transfection efficiency and low cytotoxicity in the in vitro settings of drug delivery. However, using this system to silence target genes to inhibit metastasis in colorectal cancer cells has not been widely reported and requires further investigation. In this study, we observed that expression of Rac1, a key molecule for cytoskeletal reorganization, was higher in hepatic metastatic tumor tissue compared with prime colon cancer tissue and that patients with high Rac1-expressing colon cancer showed shorter survival time. Base on these findings, we created dtACPP-PEG-DGL (dtACPPD)/shRac1 nanoparticles and demonstrated that they downregulated Rac1 expression in colon cancer cells. Moreover, we observed inhibitory effects on migration, invasion and adhesion in HCT116 colorectal cancer cells in vitro, and our results showed that Rac1 regulated colon cancer cell matrix adhesion through the regulation of cytofilament dynamics. Moreover, mechanically, repression of Rac1 inhibiting cells migration and invasion by enhancing cell to cell adhesion and reducing cell to extracellular matrix adhesion. Furthermore, when atCDPPD/shRac1 nanoparticles were administered intravenously to a HCT116 xenograft model, significant tumor metastasis to the liver was inhibited. Our results suggest that atCDPP/shRac1 nanoparticles may enable the blockade of hepatic metastasis in colon cancer.

  8. TiO2 nanofiber solid-state dye sensitized solar cells with thin TiO2 hole blocking layer prepared by atomic layer deposition

    Li, Jinwei; Chen, Xi; Xu, Weihe; Nam, Chang-Yong; Shi, Yong

    2013-01-01

    We incorporated a thin but structurally dense TiO 2 layer prepared by atomic layer deposition (ALD) as an efficient hole blocking layer in the TiO 2 nanofiber based solid-state dye sensitized solar cell (ss-DSSC). The nanofiber ss-DSSCs having ALD TiO 2 layers displayed increased open circuit voltage, short circuit current density, and power conversion efficiency compared to control devices with blocking layers prepared by spin-coating liquid TiO 2 precursor. We attribute the improved photovoltaic device performance to the structural integrity of ALD-coated TiO 2 layer and consequently enhanced hole blocking effect that results in reduced dark leakage current and increased charge carrier lifetime. - Highlights: • TiO 2 blocking locking layer prepared by atomic layer deposition (ALD) method. • ALD-coated TiO 2 layer enhanced hole blocking effect. • ALD blocking layer improved the voltage, current and efficiency. • ALD blocking layer reduced dark leakage current and increased electron lifetime

  9. TiO{sub 2} nanofiber solid-state dye sensitized solar cells with thin TiO{sub 2} hole blocking layer prepared by atomic layer deposition

    Li, Jinwei; Chen, Xi; Xu, Weihe [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Nam, Chang-Yong, E-mail: cynam@bnl.gov [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973 (United States); Shi, Yong, E-mail: Yong.Shi@stevens.edu [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2013-06-01

    We incorporated a thin but structurally dense TiO{sub 2} layer prepared by atomic layer deposition (ALD) as an efficient hole blocking layer in the TiO{sub 2} nanofiber based solid-state dye sensitized solar cell (ss-DSSC). The nanofiber ss-DSSCs having ALD TiO{sub 2} layers displayed increased open circuit voltage, short circuit current density, and power conversion efficiency compared to control devices with blocking layers prepared by spin-coating liquid TiO{sub 2} precursor. We attribute the improved photovoltaic device performance to the structural integrity of ALD-coated TiO{sub 2} layer and consequently enhanced hole blocking effect that results in reduced dark leakage current and increased charge carrier lifetime. - Highlights: • TiO{sub 2} blocking locking layer prepared by atomic layer deposition (ALD) method. • ALD-coated TiO{sub 2} layer enhanced hole blocking effect. • ALD blocking layer improved the voltage, current and efficiency. • ALD blocking layer reduced dark leakage current and increased electron lifetime.

  10. CHEMERIN (RARRES2) decreases in vitro granulosa cell steroidogenesis and blocks oocyte meiotic progression in bovine species.

    Reverchon, Maxime; Bertoldo, Michael J; Ramé, Christelle; Froment, Pascal; Dupont, Joëlle

    2014-05-01

    CHEMERIN, or RARRES2, is a new adipokine that is involved in the regulation of adipogenesis, energy metabolism, and inflammation. Recent data suggest that it also plays a role in reproductive function in rats and humans. Here we studied the expression of CHEMERIN and its three receptors (CMKLR1, GPR1, and CCRL2) in the bovine ovary and investigated the in vitro effects of this hormone on granulosa cell steroidogenesis and oocyte maturation. By RT-PCR, immunoblotting, and immunohistochemistry, we found CHEMERIN, CMKLR1, GPR1, and CCRL2 in various ovarian cells, including granulosa and theca cells, corpus luteum, and oocytes. In cultured bovine granulosa cells, INSULIN, IGF1, and two insulin sensitizers-metformin and rosiglitazone-increased rarres2 mRNA expression whereas they decreased cmklr1, gpr1, and cclr2 mRNA expression. Furthermore, TNF alpha and ADIPONECTIN significantly increased rarres2 and cmklr1 expression, respectively. In cultured bovine granulosa cells, human recombinant CHEMERIN (hRec, 200 ng/ml) reduced production of both progesterone and estradiol, cholesterol content, STAR abundance, CYP19A1 and HMGCR proteins, and the phosphorylation levels of MAPK3/MAPK1 in the presence or absence of FSH (10(-8) M) and IGF1 (10(-8) M). All of these effects were abolished by using an anti-CMKLR1 antibody. In bovine cumulus-oocyte complexes, the addition of hRec (200 ng/ml) in the maturation medium arrested most oocytes at the germinal vesicle stage, and this was associated with a decrease in MAPK3/1 phosphorylation in both oocytes and cumulus cells. Thus, in cultured bovine granulosa cells, hRec decreases steroidogenesis, cholesterol synthesis, and MAPK3/1 phosphorylation, probably through CMKLR1. Moreover, in cumulus-oocyte complexes, it blocked meiotic progression at the germinal vesicle stage and inhibited MAPK3/1 phosphorylation in both the oocytes and cumulus cells during in vitro maturation. © 2014 by the Society for the Study of Reproduction, Inc.

  11. Apoptotic block in colon cancer cells may be rectified by lentivirus mediated overexpression of caspase-9.

    Xu, D; Wang, C; Shen, X; Yu, Y; Rui, Y; Zhang, D; Zhou, Z

    2013-12-01

    At present, the inhibition of apoptosis during pathogenesis of colorectal cancer is widely recognized while the role of caspase-9 in this process remains controversial. We aimed to investigate the differential expression of caspase-9 and evaluate the therapeutic potential of expression intervention in this study. We first examined the different expression of caspase-9 in normal colon mucosa, adenoma and cancer, investigating the relationship between its expression and clinico-pathological characteristics. Secondly, overexpression of caspase-9 was established in colon cancer cell lines by lentivirus infection to study the changes in growth, proliferation and apoptosis. Compared with normal colon mucosa, the expression of caspase-9 was higher in adenoma while lower in cancer both at mRNA and protein level (P expression is more common in poorly differentiated cancers (P expression of caspase-9, poorer colony formation and slower cell proliferation. In terms of apoptosis related indicators, caspase-9 overexpression leads to higher apoptosis rate and GO/G1 arrest, while up-regulating the expression of caspase-3 (P expression from colon mucosa, adenoma to cancer suggested it may be involved in the carcinogenesis of colon cancer. The overexpression of caspase-9 exhibits an inhibitory role in cancer growth and proliferation while promoting apoptosis. However, a non-apoptotic role of caspase-9 facilitating differentiation was also implied.

  12. Lindane blocks GABAA-mediated inhibition and modulates pyramidal cell excitability in the rat hippocampal slice.

    Joy, R M; Walby, W F; Stark, L G; Albertson, T E

    1995-01-01

    An in vitro paired-pulse orthodromic stimulation technique was used to examine the effects of lindane on excitatory afferent terminals, CA1 pyramidal cells and recurrent collateral evoked inhibition in the rat hippocampal slice. This was done to establish simultaneous effects on a simple neural network and to develop procedures for more detailed analyses of the effects of lindane. Hippocampal slices 400 microns thick were perfused with oxygenated artificial cerebrospinal fluid. Electrodes were placed in the CA1 region to record extracellular population spike (PS) or excitatory postsynaptic potential (EPSP) responses to stimulation of Schaffer collateral/commissural (SC/C) fibers. Gamma-aminobutyric acid (GABA)-mediated recurrent inhibition was measured using a paired-pulse technique. Perfusion with lindane produced both time and dose dependent changes in a number of the responses measured. The most striking effect produced by lindane was the loss of GABAA-mediated recurrent collateral inhibition. This tended to occur rapidly, often before changes in EPSP or PS responses could be detected. With longer exposures to lindane, repetitive discharge of pyramidal cells developed resulting in multiple PSs to single stimuli. Lindane (50 microM) also completely reversed the effects of the injectable anesthetic, propofol, a compound known to potentiate GABAA-mediated inhibition via a direct action on the GABAA receptor-chloride channel complex. An analysis of input/output relationships at varying stimulus intensities showed that lindane increased EPSP and PS response amplitudes at any given stimulus intensity resulting in a leftward shift in the EPSP amplitude/stimulus intensity, PS amplitude/stimulus intensity and PS amplitude/EPSP amplitude relationships. This effect was most noticeable with low intensity stimuli and became progressively less so as stimulus intensities approached those yielding maximal responses. In addition lindane significantly increased paired pulse

  13. A role for the JAK-STAT1 pathway in blocking replication of HSV-1 in dendritic cells and macrophages

    Town Terrence

    2009-05-01

    Full Text Available Abstract Background Macrophages and dendritic cells (DCs play key roles in host defense against HSV-1 infection. Although macrophages and DCs can be infected by herpes simplex virus type 1 (HSV-1, both cell types are resistant to HSV-1 replication. The aim of our study was to determine factor (s that are involved in the resistance of DCs and macrophages to productive HSV-1 infection. Results We report here that, in contrast to bone marrow-derived DCs and macrophages from wild type mice, DCs and macrophages isolated from signal transducers and activators of transcription-1 deficient (STAT1-/- mice were susceptible to HSV-1 replication and the production of viral mRNAs and DNA. There were differences in expression of immediate early, early, and late gene transcripts between STAT1+/+ and STAT1-/- infected APCs. Conclusion These results suggest for the first time that the JAK-STAT1 pathway is involved in blocking replication of HSV-1 in DCs and macrophages.

  14. A role for the JAK-STAT1 pathway in blocking replication of HSV-1 in dendritic cells and macrophages

    Mott, Kevin R; UnderHill, David; Wechsler, Steven L; Town, Terrence; Ghiasi, Homayon

    2009-01-01

    Background Macrophages and dendritic cells (DCs) play key roles in host defense against HSV-1 infection. Although macrophages and DCs can be infected by herpes simplex virus type 1 (HSV-1), both cell types are resistant to HSV-1 replication. The aim of our study was to determine factor (s) that are involved in the resistance of DCs and macrophages to productive HSV-1 infection. Results We report here that, in contrast to bone marrow-derived DCs and macrophages from wild type mice, DCs and macrophages isolated from signal transducers and activators of transcription-1 deficient (STAT1-/-) mice were susceptible to HSV-1 replication and the production of viral mRNAs and DNA. There were differences in expression of immediate early, early, and late gene transcripts between STAT1+/+ and STAT1-/- infected APCs. Conclusion These results suggest for the first time that the JAK-STAT1 pathway is involved in blocking replication of HSV-1 in DCs and macrophages. PMID:19439086

  15. The EP4 receptor antagonist, L-161,982, blocks prostaglandin E2-induced signal transduction and cell proliferation in HCA-7 colon cancer cells

    Cherukuri, Durga Prasad; Chen, Xiao B.O.; Goulet, Anne-Christine; Young, Robert N.; Han, Yongxin; Heimark, Ronald L.; Regan, John W.; Meuillet, Emmanuelle; Nelson, Mark A.

    2007-01-01

    Accumulating evidence indicates that elevated levels of prostaglandin E 2 (PGE 2 ) can increase intestinal epithelial cell proliferation, and thus play a role in colorectal tumorigenesis. PGE 2 exerts its effects through four G-protein-coupled PGE receptor (EP) subtypes, named the EP1, EP2, EP3, and EP4. Increased phosphorylation of extracellular regulated kinases (ERK1/2) is required for PGE 2 to stimulate cell proliferation of human colon cancer cells. However, the EP receptor(s) that are involved in this process remain unknown. We provide evidence that L-161,982, a selective EP4 receptor antagonist, completely blocks PGE 2 -induced ERK phosphorylation and cell proliferation of HCA-7 cells. In order to identify downstream target genes of ERK1/2 signaling, we found that PGE 2 induces expression of early growth response gene-1 (EGR-1) downstream of ERK1/2 and regulates its expression at the level of transcription. PGE 2 treatment induces phosphorylation of cyclic AMP response element binding protein (CREB) at Ser133 residue and CRE-mediated luciferase activity in HCA-7 cells. Studies with dominant-negative CREB mutant (ACREB) provide clear evidence for the involvement of CREB in PGE 2 driven egr-1 transcription in HCA-7 cells. In conclusion, this study reveals that egr-1 is a target gene of PGE 2 in HCA-7 cells and is regulated via the newly identified EP4/ERK/CREB pathway. Finally our results support the notion that antagonizing EP4 receptors may provide a novel therapeutic approach to the treatment of colon cancer

  16. Biofunctionalized nanoparticles with pH-responsive and cell penetrating blocks for gene delivery

    Gaspar, V M; Marques, J G; Sousa, F; Queiroz, J A; Correia, I J; Louro, R O

    2013-01-01

    Bridging the gap between nanoparticulate delivery systems and translational gene therapy is a long sought after requirement in nanomedicine-based applications. However, recent developments regarding nanoparticle functionalization have brought forward the ability to synthesize materials with biofunctional moieties that mimic the evolved features of viral particles. Herein we report the versatile conjugation of both cell penetrating arginine and pH-responsive histidine moieties into the chitosan polymeric backbone, to improve the physicochemical characteristics of the native material. Amino acid coupling was confirmed by 2D TOCSY NMR and Fourier transform infrared spectroscopy. The synthesized chitosan–histidine–arginine (CH–H–R) polymer complexed plasmid DNA biopharmaceuticals, and spontaneously assembled into stable 105 nm nanoparticles with spherical morphology and positive surface charge. The functionalized delivery systems were efficiently internalized into the intracellular compartment, and exhibited remarkably higher transfection efficiency than unmodified chitosan without causing any cytotoxic effect. Additional findings regarding intracellular trafficking events reveal their preferential escape from degradative lysosomal pathways and nuclear localization. Overall, this assembly of nanocarriers with bioinspired moieties provides the foundations for the design of efficient and customizable materials for cancer gene therapy. (paper)

  17. Proteasome inhibitors block DNA repair and radiosensitize non-small cell lung cancer.

    Kyle R Cron

    Full Text Available Despite optimal radiation therapy (RT, chemotherapy and/or surgery, a majority of patients with locally advanced non-small cell lung cancer (NSCLC fail treatment. To identify novel gene targets for improved tumor control, we performed whole genome RNAi screens to identify knockdowns that most reproducibly increase NSCLC cytotoxicity. These screens identified several proteasome subunits among top hits, including the topmost hit PSMA1, a component of the core 20 S proteasome. Radiation and proteasome inhibition showed synergistic effects. Proteasome inhibition resulted in an 80-90% decrease in homologous recombination (HR, a 50% decrease in expression of NF-κB-inducible HR genes BRCA1 and FANCD2, and a reduction of BRCA1, FANCD2 and RAD51 ionizing radiation-induced foci. IκBα RNAi knockdown rescued NSCLC radioresistance. Irradiation of mice with NCI-H460 xenografts after inducible PSMA1 shRNA knockdown markedly increased murine survival compared to either treatment alone. Proteasome inhibition is a promising strategy for NSCLC radiosensitization via inhibition of NF-κB-mediated expression of Fanconi Anemia/HR DNA repair genes.

  18. MIIP, a cytoskeleton regulator that blocks cell migration and invasion, delays mitosis, and suppresses tumorogenesis.

    Wang, Yingmei; Wen, Jing; Zhang, Wei

    2011-02-01

    The migration and invasion inhibitory protein (MIIP) was initially discovered in a yeast two-hybrid screen for proteins that interact and inhibit the migration and invasion-promoting protein insulin-like growth factor binding protein 2 (IGFBP2). Recent studies have shown that MIIP not only modulates IGFBP2 but also regulates microtubule by binding to and inhibiting HDAC6, a class 2 histone deacetylase that deacetylates α-tubulin, heat-shock protein 90 (HSP90), and cortactin. In addition, MIIP also regulates the mitosis checkpoint, another microtubule-associated process. The location of the MIIP gene in chromosomal region 1p36, a commonly deleted region in a broad spectrum of human cancers, and the observation that MIIP attenuates tumorigenesis in a mouse model suggest that it functions as a tumor-suppressor gene. This review summarizes the recent progress in characterizing this novel protein, which regulates cell migration and mitosis, two processes that rely on the highly coordinated dynamics of the microtubule and cytoskeleton systems.

  19. Viable calves produced by somatic cell nuclear transfer using meiotic-blocked oocytes.

    De Bem, Tiago H C; Chiaratti, Marcos R; Rochetti, Raquel; Bressan, Fabiana F; Sangalli, Juliano R; Miranda, Moysés S; Pires, Pedro R L; Schwartz, Kátia R L; Sampaio, Rafael V; Fantinato-Neto, Paulo; Pimentel, José R V; Perecin, Felipe; Smith, Lawrence C; Meirelles, Flávio V; Adona, Paulo R; Leal, Cláudia L V

    2011-10-01

    Somatic cell nuclear transfer (SCNT) has had an enormous impact on our understanding of biology and remains a unique tool for multiplying valuable laboratory and domestic animals. However, the complexity of the procedure and its poor efficiency are factors that limit a wider application of SCNT. In this context, oocyte meiotic arrest is an important option to make SCNT more flexible and increase the number of cloned embryos produced. Herein, we show that the use of butyrolactone I in association with brain-derived neurotrophic factor (BDNF) to arrest the meiotic division for 24 h prior to in vitro maturation provides bovine (Bos indicus) oocytes capable of supporting development of blastocysts and full-term cloned calves at least as efficiently as nonarrested oocytes. Furthermore, the procedure resulted in cloned blastocysts with an 1.5- and twofold increase of POU5F1 and IFNT2 expression, respectively, which are well-known markers of embryonic viability. Mitochondrial DNA (mtDNA) copy number was diminished by prematuration in immature oocytes (718,585±34,775 vs. 595,579±31,922, respectively, control and treated groups) but was unchanged in mature oocytes (522,179±45,617 vs. 498,771±33,231) and blastocysts (816,627±40,235 vs. 765,332±51,104). To our knowledge, this is the first report of cloned offspring born to prematured oocytes, indicating that meiotic arrest could have significant implications for laboratories working with SCNT and in vitro embryo production.

  20. CDKL5, a novel MYCN-repressed gene, blocks cell cycle and promotes differentiation of neuronal cells.

    Valli, Emanuele; Trazzi, Stefania; Fuchs, Claudia; Erriquez, Daniela; Bartesaghi, Renata; Perini, Giovanni; Ciani, Elisabetta

    2012-01-01

    Mutations in the CDKL5 (cyclin-dependent kinase-like 5) gene are associated with a severe epileptic encephalopathy (early infantile epileptic encephalopathy type 2, EIEE2) characterized by early-onset intractable seizures, infantile spasms, severe developmental delay, intellectual disability, and Rett syndrome (RTT)-like features. Despite the clear involvement of CDKL5 mutations in intellectual disability, the function of this protein during brain development and the molecular mechanisms involved in its regulation are still unknown. Using human neuroblastoma cells as a model system we found that an increase in CDKL5 expression caused an arrest of the cell cycle in the G(0)/G(1) phases and induced cellular differentiation. Interestingly, CDKL5 expression was inhibited by MYCN, a transcription factor that promotes cell proliferation during brain development and plays a relevant role in neuroblastoma biology. Through a combination of different and complementary molecular and cellular approaches we could show that MYCN acts as a direct repressor of the CDKL5 promoter. Overall our findings unveil a functional axis between MYCN and CDKL5 governing both neuron proliferation rate and differentiation. The fact that CDKL5 is involved in the control of both neuron proliferation and differentiation may help understand the early appearance of neurological symptoms in patients with mutations in CDKL5. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Layer-by-Layer Formation of Block-Copolymer-Derived TiO2 for Solid-State Dye-Sensitized Solar Cells

    Guldin, Stefan; Docampo, Pablo; Stefik, Morgan; Kamita, Gen; Wiesner, Ulrich; Snaith, Henry J.; Steiner, Ullrich

    2011-01-01

    Morphology control on the 10 nm length scale in mesoporous TiO 2 films is crucial for the manufacture of high-performance dye-sensitized solar cells. While the combination of block-copolymer self-assembly with sol-gel chemistry yields good results

  2. EVIDENCE FOR EXISTENCE OF IMMUNOGLOBULINS THAT BLOCK OVARIAN GRANULOSA-CELL GROWTH-INVITRO - A PUTATIVE ROLE IN RESISTANT OVARY SYNDROME

    VANWEISSENBRUCH, MM; HOEK, A; VAN VLIET BLEEKER, I.; SCHOEMAKER, J; DREXHAGE, H

    The sera of 26 patients with premature ovarian failure were examined in order to detect immunoglobulin-G (IgGs) that can block FSH-induced in vitro granulosa cell DNA synthesis via, a Feulgen cytochemical bioassay system. The IgGs of four patients with polycystic ovary-like disease, five

  3. Effective Application of the Methanol-Based PreservCyt (TM) Fixative and the Cellient (TM) Automated Cell Block Processor to Diagnostic Cytopathology, Immunocytochemistry, and Molecular Biology

    van Hemel, Bettien M.; Suurmeijer, Albert J. H.

    We studied the feasibility of immunocytochemistry (ICC), in situ hybridization (ISH), and polymerase chain reaction (PCR) after Cellient automated cell block processing, and tested whether methanol-based PreservCyt fixation could replace formalin fixation, in an attempt to eliminate toxic

  4. N-Terminal Prodomain of Pfs230 Synthesized Using a Cell-Free System Is Sufficient To Induce Complement-Dependent Malaria Transmission-Blocking Activity▿

    Tachibana, Mayumi; Wu, Yimin; Iriko, Hideyuki; Muratova, Olga; MacDonald, Nicholas J.; Sattabongkot, Jetsumon; Takeo, Satoru; Otsuki, Hitoshi; Torii, Motomi; Tsuboi, Takafumi

    2011-01-01

    The aim of a malaria transmission-blocking vaccine is to block the development of malaria parasites in the mosquito and thus prevent subsequent infection of the human host. Previous studies have demonstrated that the gametocyte/gamete surface protein Pfs230 can induce transmission-blocking immunity and have evaluated Escherichia coli-produced Pfs230 as a transmission-blocking vaccine candidate. In this study, we used the wheat germ cell-free expression system to produce N-terminal fragments of Pfs230 and evaluated the transmission-blocking activity of antisera raised against the recombinant Pfs230 protein. The rabbit antisera reacted to the surface of cultured gametocytes and gametes of the Plasmodium falciparum NF54 line, recognized the 360-kDa form of parasite-produced Pfs230 by Western blot assay, and reduced the infectivity of NF54 parasites to Anopheles stefensi mosquitoes in the presence of complement in a standard membrane feeding assay. Thus, our data demonstrate that the N-terminal pro domain of Pfs230 is sufficient to induce complement-dependent transmission-blocking activity against P. falciparum. PMID:21715579

  5. N-terminal prodomain of Pfs230 synthesized using a cell-free system is sufficient to induce complement-dependent malaria transmission-blocking activity.

    Tachibana, Mayumi; Wu, Yimin; Iriko, Hideyuki; Muratova, Olga; MacDonald, Nicholas J; Sattabongkot, Jetsumon; Takeo, Satoru; Otsuki, Hitoshi; Torii, Motomi; Tsuboi, Takafumi

    2011-08-01

    The aim of a malaria transmission-blocking vaccine is to block the development of malaria parasites in the mosquito and thus prevent subsequent infection of the human host. Previous studies have demonstrated that the gametocyte/gamete surface protein Pfs230 can induce transmission-blocking immunity and have evaluated Escherichia coli-produced Pfs230 as a transmission-blocking vaccine candidate. In this study, we used the wheat germ cell-free expression system to produce N-terminal fragments of Pfs230 and evaluated the transmission-blocking activity of antisera raised against the recombinant Pfs230 protein. The rabbit antisera reacted to the surface of cultured gametocytes and gametes of the Plasmodium falciparum NF54 line, recognized the 360-kDa form of parasite-produced Pfs230 by Western blot assay, and reduced the infectivity of NF54 parasites to Anopheles stefensi mosquitoes in the presence of complement in a standard membrane feeding assay. Thus, our data demonstrate that the N-terminal pro domain of Pfs230 is sufficient to induce complement-dependent transmission-blocking activity against P. falciparum.

  6. Cardiac tissue geometry as a determinant of unidirectional conduction block: assessment of microscopic excitation spread by optical mapping in patterned cell cultures and in a computer model.

    Fast, V G; Kléber, A G

    1995-05-01

    Unidirectional conduction block (UCB) and reentry may occur as a consequence of an abrupt tissue expansion and a related change in the electrical load. The aim of this study was to evaluate critical dimensions of the tissue necessary for establishing UCB in heart cell culture. Neonatal rat heart cell cultures with cell strands of variable width emerging into a large cell area were grown using a technique of patterned cell growth. Action potential upstrokes were measured using a voltage sensitive dye (RH-237) and a linear array of 10 photodiodes with a 15 microns resolution. A mathematical model was used to relate action potential wave shapes to underlying ionic currents. UCB (block of a single impulse in anterograde direction - from a strand to a large area - and conduction in the retrograde direction) occurred in narrow cell strands with a width of 15(SD 4) microns (1-2 cells in width, n = 7) and there was no conduction block in strands with a width of 31(8) microns (n = 9, P multiple rising phases. Mathematical modelling showed that two rising phases were caused by electronic current flow, whereas local ionic current did not coincide with the rising portions of the upstrokes. (1) High resolution optical mapping shows multiphasic action potential upstrokes at the region of abrupt expansion. At the site of the maximum decrement in conduction, these peaks were largely determined by the electrotonus and not by the local ionic current. (2) Unidirectional conduction block occurred in strands with a width of 15(4) microns (1-2 cells).

  7. Methotrexate-Loaded Four-Arm Star Amphiphilic Block Copolymer Elicits CD8+ T Cell Response against a Highly Aggressive and Metastatic Experimental Lymphoma.

    Hira, Sumit Kumar; Ramesh, Kalyan; Gupta, Uttam; Mitra, Kheyanath; Misra, Nira; Ray, Biswajit; Manna, Partha Pratim

    2015-09-16

    We have synthesized a well-defined four-arm star amphiphilic block copolymer [poly(DLLA)-b-poly(NVP)]4 [star-(PDLLA-b-PNVP)4] that consists of D,L-lactide (DLLA) and N-vinylpyrrolidone (NVP) via the combination of ring-opening polymerization (ROP) and xanthate-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization. Synthesis of the polymer was verified by 1H NMR spectroscopy and gel permeation chromatography (GPC). The amphiphilic four-arm star block copolymer forms spherical micelles in water as demonstrated by transmission electron microscopy (TEM) and 1H NMR spectroscopy. Pyrene acts as a probe to ascertain the critical micellar concentration (cmc) by using fluorescence spectroscopy. Methotrexate (MTX)-loaded polymeric micelles of star-(PDLLA15-b-PNVP10)4 amphiphilic block copolymer were prepared and characterized by fluorescence and TEM studies. Star-(PDLLA15-b-PNVP10)4 copolymer was found to be significantly effective with respect to inhibition of proliferation and lysis of human and murine lymphoma cells. The amphiphilic block copolymer causes cell death in parental and MTX-resistant Dalton lymphoma (DL) and Raji cells. The formulation does not cause hemolysis in red blood cells and is tolerant to lymphocytes compared to free MTX. Therapy with MTX-loaded star-(PDLLA15-b-PNVP10)4 amphiphilic block copolymer micelles prolongs the life span of animals with neoplasia by reducing the tumor load, preventing metastasis and augmenting CD8+ T cell-mediated adaptive immune responses.

  8. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    Roehrig, John T.; Butrapet, Siritorn; Liss, Nathan M.; Bennett, Susan L.; Luy, Betty E.; Childers, Thomas; Boroughs, Karen L.; Stovall, Janae L.; Calvert, Amanda E.; Blair, Carol D.; Huang, Claire Y.-H.

    2013-01-01

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants

  9. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    Roehrig, John T., E-mail: jtr1@cdc.gov [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Butrapet, Siritorn; Liss, Nathan M. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Bennett, Susan L. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Luy, Betty E.; Childers, Thomas; Boroughs, Karen L.; Stovall, Janae L.; Calvert, Amanda E. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States); Blair, Carol D. [Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523 (United States); Huang, Claire Y.-H. [Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521 (United States)

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants.

  10. Amlexanox Blocks the Interaction between S100A4 and Epidermal Growth Factor and Inhibits Cell Proliferation.

    Ching Chang Cho

    Full Text Available The human S100A4 protein binds calcium, resulting in a change in its conformation to promote the interaction with its target protein. Human epidermal growth factor (EGF is the target protein of S100A4 and a critical ligand of the receptor EGFR. The EGF/EGFR system promotes cell survival, differentiation, and growth by activating several signaling pathways. Amlexanox is an anti-inflammatory and anti-allergic drug that is used to treat recurrent aphthous ulcers. In the present study, we determined that amlexanox interacts with S100A4 using heteronuclear single quantum correlation titration. We elucidated the interactions of S100A4 with EGF and amlexanox using fluorescence and nuclear magnetic resonance spectroscopy. We generated two binary models (for the S100A4-EGF and S100A4-amlexanox complexes and observed that amlexanox and EGF share a similar binding region in mS100A4. We also used a WST-1 assay to investigate the bioactivity of S100A4, EGF, and amlexanox, and found that amlexanox blocks the binding between S100A4 and EGF, and is therefore useful for the development of new anti-proliferation drugs.

  11. Isolation of Fully Human Antagonistic RON Antibodies Showing Efficient Block of Downstream Signaling and Cell Migration1

    Gunes, Zeynep; Zucconi, Adriana; Cioce, Mario; Meola, Annalisa; Pezzanera, Monica; Acali, Stefano; Zampaglione, Immacolata; De Pratti, Valeria; Bova, Luca; Talamo, Fabio; Demartis, Anna; Monaci, Paolo; La Monica, Nicola; Ciliberto, Gennaro; Vitelli, Alessandra

    2011-01-01

    RON belongs to the c-MET family of receptor tyrosine kinases. As its well-known family member MET, RON and its ligand macrophage-stimulating protein have been implicated in the progression and metastasis of tumors and have been shown to be overexpressed in cancer. We generated and tested a large number of human monoclonal antibodies (mAbs) against human RON. Our screening yielded three high-affinity antibodies that efficiently block ligand-dependent intracellular AKT and MAPK signaling. This effect correlates with the strong reduction of ligand-activated migration of T47D breast cancer cell line. By cross-competition experiments, we showed that the antagonistic antibodies fall into three distinct epitope regions of the RON extracellular Sema domain. Notably, no inhibition of tumor growth was observed in different epithelial tumor xenografts in nude mice with any of the antibodies. These results suggest that distinct properties beside ligand antagonism are required for anti-RON mAbs to exert antitumor effects in vivo. PMID:21286376

  12. IDENTIFICATION OF CANINE VISCERAL LEISHMANIASIS IN A PREVIOUSLY UNAFFECTED AREA BY CONVENTIONAL DIAGNOSTIC TECHNIQUES AND CELL-BLOCK FIXATION

    Tuanne Rotti ABRANTES

    2016-01-01

    Full Text Available After the report of a second case of canine visceral leishmaniasis (CVL in São Bento da Lagoa, Itaipuaçu, in the municipality of Maricá, Rio de Janeiro State, an epidemiological survey was carried out, through active search, totaling 145 dogs. Indirect immunofluorescence assay (IFA, enzyme-linked immunosorbent assay (ELISA, and rapid chromatographic immunoassay based on dual-path platform (DPP(r were used to perform the serological examinations. The parasitological diagnosis of cutaneous fragments was performed by parasitological culture, histopathology, and immunohistochemistry. In the serological assessment, 21 dogs were seropositive by IFA, 17 by ELISA, and 11 by DPP(r, with sensitivity of 66.7%, 66.7% and 50%, and specificity of 87.2%, 90.2% and 94%, respectively for each technique. The immunohistochemistry of bone marrow using the cell-block technique presented the best results, with six positive dogs found, three of which tested negative by the other parasitological techniques. Leishmania sp. was isolated by parasitological culture in three dogs. The detection of autochthonous Leishmania infantum in Itaipuaçu, and the high prevalence of seropositive dogs confirm the circulation of this parasite in the study area and alert for the risk of expansion in the State of Rio de Janeiro.

  13. Abalone Hemocyanin Blocks the Entry of Herpes Simplex Virus 1 into Cells: a Potential New Antiviral Strategy

    Talaei Zanjani, Negar; Miranda-Saksena, Monica; Valtchev, Peter; Hueston, Linda; Diefenbach, Eve; Sairi, Fareed; Gomes, Vincent G.

    2015-01-01

    A marine-derived compound, abalone hemocyanin, from Haliotis rubra was shown to have a unique mechanism of antiviral activity against herpes simplex virus 1 (HSV-1) infections. In vitro assays demonstrated the dose-dependent and inhibitory effect of purified hemocyanin against HSV-1 infection in Vero cells with a 50% effective dose (ED50) of 40 to 50 nM and no significant toxicity. In addition, hemocyanin specifically inhibited viral attachment and entry by binding selectively to the viral surface glycoproteins gD, gB, and gC, probably by mimicking their receptors. However, hemocyanin had no effect on postentry events and did not block infection by binding to cellular receptors for HSV. By the use of different mutants of gD and gB and a competitive heparin binding assay, both protein charge and conformation were shown to be the driving forces of the interaction between hemocyanin and viral glycoproteins. These findings also suggested that hemocyanin may have different motifs for binding to each of the viral glycoproteins B and D. The dimer subunit of hemocyanin with a 10-fold-smaller molecular mass exhibited similar binding to viral surface glycoproteins, showing that the observed inhibition did not require the entire multimer. Therefore, a small hemocyanin analogue could serve as a new antiviral candidate for HSV infections. PMID:26643336

  14. The translational blocking of α5 and α6 integrin subunits affects migration and invasion, and increases sensitivity to carboplatin of SKOV-3 ovarian cancer cell line

    Villegas-Pineda, Julio César, E-mail: jcvillegas@cinvestav.mx; Toledo-Leyva, Alfredo, E-mail: toledo_leyva@hotmail.com; Osorio-Trujillo, Juan Carlos, E-mail: clostrujillo2@yahoo.com.mx; Hernández-Ramírez, Verónica Ivonne, E-mail: arturomvi@hotmail.com; Talamás-Rohana, Patricia, E-mail: ptr@cinvestav.mx

    2017-02-15

    Epithelial ovarian cancer is the most lethal gynecologic malignancy. Integrins, overexpressed in cancer, are involved in various processes that favor the development of the disease. This study focused on determining the degree of involvement of α5, α6 and β3 integrin subunits in the establishment/development of epithelial ovarian cancer (EOC), such as proliferation, migration, invasion, and response to carboplatin. The translation of the α5, α6 and β3 integrins was blocked using morpholines, generating morphant cells for these proteins, which were corroborated by immunofluorescence assays. WST-1 proliferation assay showed that silencing of α5, α6, and β3 integrins does not affect the survival of morphants. Wound healing and transwell chamber assays showed that blocking α5 and α6 integrins decrease, in lesser and greater level respectively, the migratory and the invasive capacity of SKOV-3 cells. Finally, blocking α5 and α6 integrins partially sensitized the cells response to carboplatin, while blocking integrin β3 generated resistance to this drug. Statistical analyses were performed with the GraphPad Prism 5.0 software employing one way and two-way ANOVA tests; data are shown as average±SD. Results suggest that α5 and α6 integrins could become good candidates for chemotherapy targets in EOC.

  15. Detection block

    Bezak, A.

    1987-01-01

    A diagram is given of a detection block used for monitoring burnup of nuclear reactor fuel. A shielding block is an important part of the detection block. It stabilizes the fuel assembly in the fixing hole in front of a collimator where a suitable gamma beam is defined for gamma spectrometry determination of fuel burnup. The detector case and a neutron source case are placed on opposite sides of the fixing hole. For neutron measurement for which the water in the tank is used as a moderator, the neutron detector-fuel assembly configuration is selected such that neutrons from spontaneous fission and neutrons induced with the neutron source can both be measured. The patented design of the detection block permits longitudinal travel and rotation of the fuel assembly to any position, and thus more reliable determination of nuclear fuel burnup. (E.S.). 1 fig

  16. Local anesthetic sympathectomy restores fMRI cortical maps in CRPS I after upper extremity stellate blockade: a prospective case study.

    Stude, Philipp; Enax-Krumova, Elena K; Lenz, Melanie; Lissek, Silke; Nicolas, Volkmar; Peters, Soeren; Westermann, Amy; Tegenthoff, Martin; Maier, Christoph

    2014-01-01

    Patients with complex regional pain syndrome type I (CRPS I) show a cortical reorganization with contralateral shrinkage of cortical maps in S1. The relevance of pain and disuse for the development and the maintenance of this shrinkage is unclear. Aim of the study was to assess whether short-term pain relief induces changes in the cortical representation of the affected hand in patients with CRPS type I. Case series analysis of prospectively collected data. We enrolled a case series of 5 consecutive patients with CRPS type I (disease duration 3 - 36 months) of the non-dominant upper-limb and previously diagnosed sympathetically maintained pain (SMP) by reduction of the pain intensity of more than > 30% after prior diagnostic sympathetic block. We performed fMRI for analysis of the cortical representation of the affected hand immediately before as well as one hour after isolated sympathetic block of the stellate ganglion on the affected side. Wilcoxon-Test, paired t-test, P CRPS, and that these are rapidly reversible.

  17. Fabrication of honeycomb-structured poly(ethylene glycol)-block-poly(lactic acid) porous films and biomedical applications for cell growth

    Yao, Bingjian [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China); College of chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, Jinan 250014 (China); Zhu, Qingzeng, E-mail: qzzhu@sdu.edu.cn [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China); Yao, Linli [Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, Shandong University School of Medicine, 250012 Jinan (China); Hao, Jingcheng [Key Laboratory of Special Functional Aggregated Materials, Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250199 (China)

    2015-03-30

    Graphical abstract: - Highlights: • Honeycomb-structured PEG-PLA porous films were fabricated. • The organization of pores depends on molecular weight ratio of PEG-to-PLA block. • The pores in the film were internally decorated with a layer of PEG. • The honeycomb-structured PEG-PLA film was suitable as a substrate for cell growth. - Abstract: A series of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) copolymers with a hydrophobic PLA block of different molecular weights and a fixed length hydrophilic PEG were synthesized successfully and characterized. These amphiphilic block copolymers were used to fabricate honeycomb-structured porous films using the breath figure (BF) templating technique. The surface topology and composition of the highly ordered pattern film were further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The results indicated that the PEG-to-PLA block molecular weight ratio influenced the BF film surface topology. The film with the best ordered pores was obtained with a PEG-to-PLA ratio of 2.0 × 10{sup 3}:3.0 × 10{sup 4}. The self-organization of the hydrophilic PEG chains within the pores was confirmed by XPS and fluorescence labeled PEG. A model is proposed to elucidate the stabilization process of the amphiphilic PEG-PLA aggregated architecture on the water droplet-based templates. In addition, GFP-U87 cell viability has been investigated by MTS test and the cell morphology on the honeycomb-structured PEG-PLA porous film has been evaluated using phase-contrast microscope. This porous film is shown to be suitable as a matrix for cell growth.

  18. Fabrication of honeycomb-structured poly(ethylene glycol)-block-poly(lactic acid) porous films and biomedical applications for cell growth

    Yao, Bingjian; Zhu, Qingzeng; Yao, Linli; Hao, Jingcheng

    2015-01-01

    Graphical abstract: - Highlights: • Honeycomb-structured PEG-PLA porous films were fabricated. • The organization of pores depends on molecular weight ratio of PEG-to-PLA block. • The pores in the film were internally decorated with a layer of PEG. • The honeycomb-structured PEG-PLA film was suitable as a substrate for cell growth. - Abstract: A series of poly(ethylene glycol)-block-poly(lactic acid) (PEG-PLA) copolymers with a hydrophobic PLA block of different molecular weights and a fixed length hydrophilic PEG were synthesized successfully and characterized. These amphiphilic block copolymers were used to fabricate honeycomb-structured porous films using the breath figure (BF) templating technique. The surface topology and composition of the highly ordered pattern film were further characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fluorescence microscopy. The results indicated that the PEG-to-PLA block molecular weight ratio influenced the BF film surface topology. The film with the best ordered pores was obtained with a PEG-to-PLA ratio of 2.0 × 10 3 :3.0 × 10 4 . The self-organization of the hydrophilic PEG chains within the pores was confirmed by XPS and fluorescence labeled PEG. A model is proposed to elucidate the stabilization process of the amphiphilic PEG-PLA aggregated architecture on the water droplet-based templates. In addition, GFP-U87 cell viability has been investigated by MTS test and the cell morphology on the honeycomb-structured PEG-PLA porous film has been evaluated using phase-contrast microscope. This porous film is shown to be suitable as a matrix for cell growth

  19. 4P-NPD ultra thin-films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    Patil, Bhushan Ramesh; Liu, Yiming; Qamar, Talha

    2017-01-01

    Exciton blocking effects from ultra thin layers of N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-diamine (4P-NPD) was investigated in small molecule based inverted Organic Solar Cells (OSCs) using Tetraphenyldibenzoperiflanthene (DBP) as the electron donor material...... and fullerene (C70) as the electron acceptor material. The short-circuit current density (Jsc) and PCE of the optimized OSCs with 0.7 nm thick 4P-NPD were approx. 16 % and 24 % higher, respectively, compared to reference devices without exciton blocking layers. Drift diffusion based device modeling...... was conducted to model the full Current density – Voltage (JV) characteristics and EQE spectrum of the OSCs, and photoluminescence measurements was conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies...

  20. Influences of alcoholic solvents on spray pyrolysis deposition of TiO{sub 2} blocking layer films for solid-state dye-sensitized solar cells

    Jiang, Changyun, E-mail: jiangc@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Koh, Wei Lin; Leung, Man Yin [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Hong, Wei [Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Li, Yuning, E-mail: yuning.li@uwaterloo.ca [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Zhang, Jie [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore)

    2013-02-15

    Influences of alcoholic solvents for titanium diisopropoxide bis(acetylacetonate) (TPA) precursor solutions on the spray pyrolysis deposited TiO{sub 2} films and the photovoltaic performance of the solid-state dye-sensitized solar cells (SDSCs) using these TiO{sub 2} films as the blocking layers were investigated. Smooth TiO{sub 2} films were obtained by spray pyrolysis deposition of a TPA solution in isopropanol (IPA) at a relatively low temperature of 260 Degree-Sign C. On the other hand, when ethanol was used as solvent, the TiO{sub 2} films fabricated at the same temperature showed much rougher surfaces with many pinholes. Our results showed that ethanol reacts with TPA to form titanium diethoxide bis(acetylacetonate) (TEA), which requires a higher thermal decomposition temperature than that of TPA. SDSCs with TiO{sub 2} blocking layer films fabricated using a TPA solution in IPA showed higher power conversion efficiencies with smaller variations. - Graphical abstract: Alcoholic solvents used for the TiO{sub 2} precursor play a critical role in determining the surface morphology of blocking layers and thus the photovoltaic performance of the SDSCs. Highlights: Black-Right-Pointing-Pointer Solvent influences morphology of spray pyrolysis deposited TiO{sub 2} blocking layer. Black-Right-Pointing-Pointer Ethanol reacts with TPA, resulting poor quality of blocking layer. Black-Right-Pointing-Pointer Isopropanol is better than ethanol for obtaining smooth blocking layer. Black-Right-Pointing-Pointer SDSC with blocking layer made with isopropanol showed better performance.

  1. Comparison of diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration cytology and cell block in solid lesions

    Avinash Bhat Balekuduru

    2017-01-01

    Full Text Available Background and Aim: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA is a procedure of choice for the diagnostic evaluation of submucosal and periluminal lesions. Tissue sample can be obtained by EUS-FNA cytology (FNAC or cell block (CB. The aim of the present study is to compare diagnostic yield of EUS-FNA CB and cytology in the absence of onsite pathologist following a protocol-based EUS-FNA approach in solid lesions. Patients and Methods: Participants who underwent EUS-FNA at our center for solid submucosal or periluminal lesions (pancreas, lymph node, and liver between 2014 and 2016 were included, retrospectively. The indication for the procedure along with the clinical and other investigation details and the final etiological diagnosis were recorded on uniform structured data forms. The diagnostic yield of cytology and CB were compared using McNemar's test. The P < 0.05 was considered statistically significant. Results: EUS-FNA for solid lesion was performed in 130 lesions in 101 patients during the study period. Their mean age was 52.5 ± 12 years and 42.5% were female. Pancreatic masses were the most common lesions (37.7% followed by lymph nodes (36.9%. Submucosal lesions (17.7% and liver lesions (7.7% accounted for rest of the cases. The overall diagnostic yield for EUS-FNAC (70% and CB (74.6% was not significantly different (P = 0.3 and their combined yield was 85.3%. For the 23 patients with submucosal lesion, diagnostic yield of CB (82.6% was significantly better than cytology (47.8%, P = 0.04. Conclusions: EUS-guided CB has better yield compared to cytology in gastrointestinal submucosal lesions. The combination of CB with cytology improves the overall yield of the procedure; and hence, they should be considered complimentary rather than alternatives.

  2. Performance enhancement of perovskite solar cells with Mg-doped TiO2 compact film as the hole-blocking layer

    Wang, Jing; Qin, Minchao; Tao, Hong; Ke, Weijun; Chen, Zhao; Wan, Jiawei; Qin, Pingli; Lei, Hongwei;