scholarly journals Functional role of intrahepatic monocyte subsets for the progression of liver inflammation and liver fibrosis in vivo

2012 ◽  
Vol 5 (S1) ◽  
Author(s):  
Frank Tacke
Keyword(s):  
Liver Fibrosis ◽  
Functional Role ◽  
Liver Inflammation ◽  
Monocyte Subsets

scholarly journals WNT-5A regulates TGF-β-related activities in liver fibrosis

2017 ◽  
Vol 312 (3) ◽  
pp. G219-G227 ◽  
Author(s):  
Leonie Beljaars ◽  
Sara Daliri ◽  
Christa Dijkhuizen ◽  
Klaas Poelstra ◽  
Reinoud Gosens
Keyword(s):  
Liver Fibrosis ◽  
Functional Role ◽  
Collagen Type ◽  
Collagen Type I ◽  
Matrix Proteins ◽  
Type I ◽  
Human Livers

WNT-5A is a secreted growth factor that belongs to the noncanonical members of the Wingless-related MMTV-integration family. Previous studies pointed to a connection between WNT-5A and the fibrogenic factor TGF-β warranting further studies into the functional role of WNT-5A in liver fibrosis. Therefore, we studied WNT-5A expressions in mouse and human fibrotic livers and examined the relation between WNT-5A and various fibrosis-associated growth factors, cytokines, and extracellular matrix proteins. WNT-5A gene and protein expressions were significantly increased in fibrotic mouse and human livers compared with healthy livers. Regression or therapeutic intervention in mice resulted in decreased hepatic WNT-5A levels paralleled by lower collagen levels. Immunohistochemical analysis showed WNT-5A staining in fibrotic septa colocalizing with desmin staining indicating WNT-5A expression in myofibroblasts. In vitro studies confirmed WNT-5A expression in this cell type and showed that TGF-β significantly enhanced WNT-5A expression in contrast to PDGF-BB and proinflammatory cytokines IL-1β and TNF-α. Additionally, TGF-β induces the expression of the WNT receptors FZD2 and FZD8. After silencing of WNT-5A, reduced levels of collagen type I, vimentin, and fibronectin in TGF-β-stimulated myofibroblasts were measured compared with nonsilencing siRNA-treated controls. Interestingly, the antifibrotic cytokine IFNγ suppressed WNT-5A in vitro and in vivo. IFNγ-treated fibrotic mice showed significantly less WNT-5A expression compared with untreated fibrotic mice. In conclusion, WNT-5A paralleled collagen I levels in fibrotic mouse and human livers. WNT-5A expression in myofibroblasts is induced by the profibrotic factor TGF-β and plays an important role in TGF-β-induced regulation of fibrotic matrix proteins, whereas its expression can be reversed upon treatment, both in vitro and in vivo. NEW & NOTEWORTHY This study describes the localization and functional role of WNT-5A in human and mouse fibrotic livers. Hepatic WNT-5A expression parallels collagen type I expression. In vivo and in vitro, the myofibroblasts were identified as the key hepatic cells producing WNT-5A. WNT-5A is under control of TGF-β and its activities are primarily profibrotic.

scholarly journals Cathepsin G-dependent platelet stimulation by activated polymorphonuclear leukocytes and its inhibition by antiproteinases: role of P-selectin-mediated cell-cell adhesion

Blood ◽  
1993 ◽  
Vol 81 (11) ◽  
pp. 2947-2957 ◽  
Author(s):  
V Evangelista ◽  
P Piccardoni ◽  
JG White ◽  
G de Gaetano ◽  
C Cerletti
Keyword(s):  
Functional Role ◽  
Polymorphonuclear Leukocytes ◽  
Platelet Adhesion ◽  
Inhibitory Effect ◽  
Serotonin Release ◽  
Cathepsin G ◽  
Inhibitory Antibody ◽  
Neuraminidase Treatment

Human PMN stimulated by fMLP are able to activate coincubated, autologous platelets. Cathepsin G, a neutral serine protease stored in the azurophilic granules of PMN, is the major platelet activator in this system. We previously proposed that shear-induced close PMN- platelet contact creates the conditions for which cathepsin G activity on platelets is protected against antiproteinases. The aim of this study was to investigate the adhesive mechanisms, possibly creating between PMN and platelet membranes the microenvironment in which cathepsin G, discharged from stimulated PMN onto adherent platelets, is protected against antiproteinases. Microscopic examination showed that under conditions of high shear, 71.3% +/- 6.1% of PMN were associated to platelets forming small clumps. This percentage decreased to 10% +/- 2% and 13% +/- 4%, respectively, in the presence of an inhibitory antibody to P-selectin or 20 mmol/L mannose-1-phosphate and to 10.8% +/- 3.7% when cells were not stirred. Similarly, PMN pretreatment with neuraminidase abolished PMN binding to platelets. These results indicate that P-selectin mediates PMN-platelet adhesion occurring before PMN stimulation. Prevention of PMN-platelet contact significantly potentiated the inhibitory effect of alpha 1-protease inhibitor on subsequent cathepsin G-induced platelet serotonin release. Because anti-P-selectin antibody, mannose-1-phosphate, and neuraminidase treatment of PMN did not modify PMN-induced platelet activation in the absence of antiproteinases, it is suggested that P- selectin-mediated PMN-platelet adhesion results in the formation of a sequestered microenvironment between cell membranes, in which higher amounts of antiproteinases are required to prevent the activity of released cathepsin G. These data add a new functional role to P- selectin-mediated PMN-platelet adhesion that could be important in vivo because of the presence of antiproteinases in plasma.

scholarly journals LncRNA NEAT1/microRNA-129-5p/SOCS2 axis regulates liver fibrosis in alcoholic steatohepatitis

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Junfeng Ye ◽  
Yuanqiang Lin ◽  
Ying Yu ◽  
Di Sun
Keyword(s):  
Liver Fibrosis ◽  
Liver Function ◽  
Inflammatory Factors ◽  
Cytokine Signaling ◽  
Alcoholic Fatty Liver ◽  
Alcoholic Steatohepatitis ◽  
Inflammation Reaction

Abstract Background Long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) has been reported to play an essential role in non-alcoholic fatty liver disease. However, the role of NEAT1 in regulation of alcoholic steatohepatitis (ASH) remains largely unknown. This study aims to explore the role of NEAT1 in ASH by mediating microRNA-129-5p (miR-129-5p) targeting suppressor of cytokine signaling 2 (SOCS2). Methods NEAT1, miR-129-5p and SOCS2 expression in serum of ASH patients were assessed. In the in vitro cellular experiment, we transfected siRNAs, oligonucleotides or plasmids into ethanol-induced AML-12 mouse hepatocytes to alter NEAT1 and miR-129-5p expression, and inflammatory factors and lipid content were determined. In the in vivo animal experiment, we injected lentiviruses carrying siRNAs, oligonucleotides or plasmids onto ASH mice (ASH induced by feeding mice a Lieber-DeCarli ethanol diet) to alter NEAT1 and miR-129-5p expression through the tail vein. Serum liver function, blood lipids and inflammatory factors were detected; liver histopathology, liver cell apoptosis, and fibrosis were observed. The relationship between NEAT1 and miR-129-5p, or between miR-129-5p and SOCS2 was verified. Results MiR-129-5p was reduced while NEAT1 and SOCS2 were elevated in ASH. Inhibited NEAT1 or elevated miR-129-5p suppressed the elevated lipid metabolism and restrained inflammation reaction in ethanol-stimulated AML-12 cells. The promoted miR-129-5p and inhibited NEAT1 could improve the liver function and repress blood lipid, inflammation reaction, hepatocyte apoptosis and liver fibrosis in ethanol-induced ASH mice. Furthermore, NEAT1 could negatively regulate miR-129-5p to target SOCS2. Conclusion We have found that the inhibited NEAT1 could suppress liver fibrosis in ASH mice by promoting miR-129-5p and restraining SOCS2, thereby decelerating the development of ASH.

Review article: the signalling and functional role of the extracellular matrix in the development of liver fibrosis

2020 ◽  
Vol 52 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Ida Falk Villesen ◽  
Samuel Joseph Daniels ◽  
Diana Julie Leeming ◽  
Morten Asser Karsdal ◽  
Mette Juul Nielsen
Keyword(s):  
Extracellular Matrix ◽  
Liver Fibrosis ◽  
Functional Role ◽  
Review Article

Contribution of R domain phosphoserines to the function of CFTR studied in Fischer rat thyroid epithelia

2000 ◽  
Vol 279 (5) ◽  
pp. L835-L841 ◽  
Author(s):  
Olafur Baldursson ◽  
Herbert A. Berger ◽  
Michael J. Welsh
Keyword(s):  
Functional Role ◽  
Transmembrane Conductance Regulator ◽  
Regulatory Domain ◽  
Wild Type ◽  
Transmembrane Conductance ◽  
Dependent Protein ◽  
Rat Thyroid ◽  
Cystic Fibrosis Transmembrane

The regulatory domain of cystic fibrosis transmembrane conductance regulator (CFTR) regulates channel activity when several serines are phosphorylated by cAMP-dependent protein kinase. To further define the functional role of individual phosphoserines, we studied CFTR containing previously studied and new serine to alanine mutations. We expressed these constructs in Fischer rat thyroid epithelia and measured transepithelial Cl− current. Mutation of four in vivo phosphorylation sites, Ser660, Ser737, Ser795, and Ser813 (S-Quad-A), substantially decreased cAMP-stimulated current, suggesting that these four sites account for most of the phosphorylation-dependent response. Mutation of either Ser660 or Ser813 alone significantly decreased current, indicating that these residues play a key role in phosphorylation-dependent stimulation. However, neither Ser660 nor Ser813 alone increased current to wild-type levels; both residues were required. Changing Ser737 to alanine increased current above wild-type levels, suggesting that phosphorylation of Ser737 may inhibit current in wild-type CFTR. These data help define the functional role of regulatory domain phosphoserines and suggest interactions between individual phosphoserines.

scholarly journals Integrin α10, a Novel Therapeutic Target in Glioblastoma, Regulates Cell Migration, Proliferation, and Survival

Cancers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 587 ◽  
Author(s):  
Matilda Munksgaard Thorén ◽  
Katarzyna Chmielarska Masoumi ◽  
Cecilia Krona ◽  
Xiaoli Huang ◽  
Soumi Kundu ◽  
...  
Keyword(s):  
Cell Death ◽  
Therapeutic Target ◽  
Functional Role ◽  
Treatment Strategies ◽  
Antibody Drug Conjugate ◽  
Potential Therapeutic Target ◽  
Sphere Formation

New, effective treatment strategies for glioblastomas (GBMs), the most malignant and invasive brain tumors in adults, are highly needed. In this study, we investigated the potential of integrin α10β1 as a therapeutic target in GBMs. Expression levels and the role of integrin α10β1 were studied in patient-derived GBM tissues and cell lines. The effect of an antibody–drug conjugate (ADC), an integrin α10 antibody conjugated to saporin, on GBM cells and in a xenograft mouse model was studied. We found that integrin α10β1 was strongly expressed in both GBM tissues and cells, whereas morphologically unaffected brain tissues showed only minor expression. Partial or no overlap was seen with integrins α3, α6, and α7, known to be expressed in GBM. Further analysis of a subpopulation of GBM cells selected for high integrin α10 expression demonstrated increased proliferation and sphere formation. Additionally, siRNA-mediated knockdown of integrin α10 in GBM cells led to decreased migration and increased cell death. Furthermore, the ADC reduced viability and sphere formation of GBM cells and induced cell death both in vitro and in vivo. Our results demonstrate that integrin α10β1 has a functional role in GBM cells and is a novel, potential therapeutic target for the treatment of GBM.

Identifying the Functional Role of Martinotti Cells in Cortical Sensory Processing

2009 ◽  
Vol 102 (1) ◽  
pp. 9-11 ◽  
Author(s):  
James C. H. Cottam
Keyword(s):  
Sensory Processing ◽  
Pyramidal Cell ◽  
Functional Significance ◽  
Functional Role ◽  
Neural Computation ◽  
Inhibitory Interneurons ◽  
Local Circuit ◽  
Processing Function

Inhibitory interneurons are highly diverse, although the functional significance of their diversity is not yet well understood. This presents a barrier to understanding neural computation at the local circuit level. This review focuses on a recent study by Murayama et al. who used a novel in vivo technique in neocortex to demonstrate a specific sensory processing function of dendritic-targeting Martinotti interneurons. The function of Martinotti cells arises from their interaction with layer 5 pyramidal cell dendrites.

scholarly journals Taurocholate Induces Connective Tissue Growth Factor Expression in Hepatocytes Through ERK-YAP Signaling

2018 ◽  
Vol 50 (5) ◽  
pp. 1711-1725
Author(s):  
Bin Yu ◽  
Guan-nan Jin ◽  
Mei Ma ◽  
Hui-fang Liang ◽  
Bi-xiang Zhang ◽  
...  
Keyword(s):  
Growth Factor ◽  
Liver Fibrosis ◽  
Western Blotting ◽  
Tissue Growth ◽  
Hepatic Cell ◽  
Erk Signaling ◽  
Rt Pcr ◽  
Hepatic Cell Lines

Background/Aims: Cholestasis is characterized by intrahepatic accumulation of cytotoxic bile acids (BAs), ultimately leading to fibrosis and cirrhosis, but the precise role of BAs in cholestasis-induced liver fibrosis remains largely elusive. In this study, we investigated the role and the potential mechanisms of BAs during cholestasis in vivo and in vitro. Methods: The effect of BAs during cholestasis was studied in bile duct ligation (BDL) rat models in vivo. We performed immunohistochemistry, Western blotting, and quantitative RT-PCR to investigate the expression of connective tissue growth factor (CTGF/CCN2) in rat liver during cholestasis. The hepatic cell lines AML12 and BRL were stimulated with taurocholate (TC) and the level of CTGF/CCN2, and activation of ERK, Akt, p38 MAPK, JNK, YAP, and TGF-β/Smad signaling were examined using Western blotting. Next, to elucidate the mechanism underlying bile acid-induced CTGF/CCN2, we treated the cells with MEK1/2 inhibitor (U0126), YAP function inhibitor (verteporfin), p38 kinase inhibitor (SB203580), Akt inhibitor (MK2206), and small interfering RNA (siRNA) targeting mek1, erk, and yap in cooperation with TC. Besides, we confirmed the activation of these signaling pathways in BDL and sham rat livers by immunohistochemistry, Western blotting, and quantitative RT-PCR. Results: In this study, we confirmed that the expression of CTGF/CCN2 was increased in BDL-induced rodent cholestatic liver fibrosis. In addition, we showed that TC, the main component of BAs, enhanced the synthesis of CTGF/ CCN2 in AML12 and BRL hepatic cell lines. Moreover, we demonstrated that TC activated ERK, Akt, and YAP signaling in hepatocytes, but the precise roles of these signaling cascades in the expression of CTGF/CCN2 were different: TC-induced expression of CTGF/CCN2 was mediated by ERK-YAP signaling, whereas Akt signaling inhibited ERK signaling and YAP and subsequently the expression of CTGF/CCN2 in hepatocytes. Furthermore, YAP functioned as a downstream regulator of ERK signaling in TC-induced CTGF/CCN2 expression in hepatocytes. Conclusion: Our report provides evidence for the role of conjugated BAs in liver fibrosis and suggests that the production of CTGF/CCN2, induced by conjugated BAs via ERK-YAP axis activation, may be a therapeutic target in cholestasis-induced liver fibrosis.

Podocalyxin Negatively Regulates Stress Myelopoiesis, Directly Binds Rap-1A and Modulates Its G-CSF-Induced Activity

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1184-1184
Author(s):  
Pan Li ◽  
Rose McGlauflin ◽  
Amanda J Favreau ◽  
Edward Jachimowicz ◽  
Calvin Vary ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Functional Role ◽  
Blood Analysis ◽  
Wild Type ◽  
Hematopoietic Progenitors ◽  
Gm Csf ◽  
Peripheral Blood Analysis ◽  
Specific Deletion

Abstract Podocalyxin (PodxL) is a CD34 family member previously identified to mark hematopoietic stem cells (HSCs) and other progenitor cells. Previously, we discovered PodxL as a potent erythropoietin (EPO) response gene and demonstrated to promote egression of immature reticulocytes from bone marrow into circulation. PodxL is upregulated in several cancers, including myeloid and lymphoid leukemia. Herein, we aim to define the functional role of PodxL in hematopoiesis - specifically myelopoiesis - by employing conditional PodxL knock out (KO) mouse models. Hematopoietic-specific deletion was achieved using Cre mice with a Vav1 driver and myeloid-specific deletion was achieved with Lyzm2 - Cre driver. We confirmed the deletion of exons 3-7 at the gene, transcript and protein levels using PCR, RT-qPCR and western blotting, respectively. Peripheral blood analysis revealed no difference in blood cell lineages for either KO mouse strain. At steady state, colony forming unit-granulocyte/macrophage (CFU-GM) assay also showed no difference between the KO strains and wild type. In order to examine the functional role of PodxL during stress myelopoiesis, PodxL-/- ; Vav1-Cre mice were treated with 5-Fluorouracil (5FU), a chemotherapeutic agent induces myeloablation. Notably, during rebound of neutrophils, the PodxL-/- ; Vav1-Cre mice showed a sharp increase in neutrophil counts at day 12.5, which at later time points reverted to normal levels comparable to wild type mice. Previously, our in silico analyses combined with outcomes from truncated EpoR knock-in alleles had revealed that PodxL is a potential STAT5 transcriptional target. Here, we tested if G-CSF induces PodxL expression in hematopoietic progenitors. In vivo, G-CSF significantly induced PodxL expression four fold. We then tested the role of PodxL in G-CSF induced neutrophil formation in vivo. Both KO strains (Podxl-/-;Vav1-Cre and Podxl-/-;Lyzm2-Cre) and wild type were treated with G-CSF (125ug/kg/day) for 5 days. Peripheral blood analysis revealed increased neutrophil and monocyte levels in the PodxL-/-;Vav1-Cremice. In order to then determine a possible role of PodxL at the progenitor level, CFU-GM assays were performed. PodxL-/- ; lyzm2-Cre mice had increased colony forming capabilities but there was no difference in PodxL-/-;Vav1-Cre mice compared to wild type. Our results imply that PodxL is playing a negative regulatory role in stress myelopoiesis. Interestingly, the deletion of PodxL in hematopoietic progenitors (Vav1-Cre) resulted in enhanced migration of neutrophils, whereas deletion of PodxL in myeloid compartment (Lyzm2-Cre) resulted in decreased neutrophil migration. This may be in part due to a compensatory effect by CD34 in the hematopoietic compartment. To dissect the molecular mechanism of PodxL during stress myelopoiesis, upon in vivo G-CSF treatment, bone marrow derived hematopoietic progenitors were isolated and PodxL protein was immunoprecipitated. LC-MS/MS proteomic analysis was performed to identify the interacting partners with PodxL. Rap-1A, a small GTPase and member of the RAS family, was among the top interacting proteins. Rap-1A has been shown to promote adhesion and migration of myeloid cells. The association of PodxL with Rap-1A was further confirmed in hematopoietic progenitors by immunoprecipitation and western blotting. To determine if the interaction of PodxL directly regulates Rap-1A activity, a GTP-Rap-1A activity assay was performed in response to G-CSF, GM-CSF and IL-3. Rap-1A activity was significantly elevated in hematopoietic progenitors upon G-CSF treatment in PodxL-/-:Vav1-Cre mice compared to wild type, followed by IL3; however, GM-CSF did not affect Rap-1A activity. In conclusion, our results indicate an important functional role for PodxL in stress myelopoiesis, a function likely mediated via Rap-1A. A complete understanding of the PodxL/Rap-1A axis may reveal important molecular insights into G-CSF-induced mobilization of neutrophils and provide mechanistic understanding into the pathological role of PodxL in aggressive cancers, including leukemia, which in turn may facilitate identification of novel therapeutic targets in PodxL associated cancers. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document