scholarly journals HIVAN phenotype: consequence of epithelial mesenchymal transdifferentiation

2010 ◽  
Vol 298 (3) ◽  
pp. F734-F744 ◽  
Author(s):  
Anju Yadav ◽  
Sridevi Vallabu ◽  
Dileep Kumar ◽  
Guohua Ding ◽  
Douglas N. Charney ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
De Novo ◽  
Smooth Muscle Actin ◽  
Tissue Expression ◽  
Renal Tissue ◽  
Specific Protein ◽  
Cell Phenotype ◽  
Renal Epithelial Cell

Human immunodeficiency virus (HIV)-1-associated nephropathy (HIVAN) is characterized by proliferation of glomerular and tubular epithelial cells. We studied the role of epithelial mesenchymal transdifferentiation (EMT) in the development of HIVAN phenotype. Renal cortical sections from six FVB/N (control) and six Tg26 (HIVAN) mice were immunolabeled for PCNA, α-smooth muscle actin (α-SMA), fibroblast-specific protein-1 (FSP1), CD3, and F4/80. Since periglomerular cells (PGCs) and peritubular cells (PTCs) did not show any labeling for CD3 and F4/80 but showed labeling for α-SMA or FSP1, it appears that these were myofibroblasts that migrated from either glomerular or tubular sites, respectively. Occurrence of EMT was also supported by diminished expression of E-cadherin by renal epithelial cells in Tg26 mice. Interestingly, Tg26 mice also showed enhanced renal tissue expression of ZEB2; henceforth, it appears that transcription of molecules required for maintenance of de novo renal epithelial cell phenotype was suppressed. To evaluate the role of ANG II, Tg26 mice in groups of three were administered either normal saline or telmisartan (an AT1 receptor blocker) for 2 wk, followed by evaluation for renal cell EMT. Renal cortical section of Tg26 mice showed a sevenfold increase ( P < 0.001) in parietal epithelial cell (PEC)-PGC and a threefold increase ( P < 0.01) in tubular cell (TC)-PTC proliferation (PCNA-positive cells). Similarly, both PECs-PGCs and TCs-PTCs in Tg26 mice showed enhanced expression of α-SMA and FSP1. Both PECs and podocytes contributed to the glomerular proliferative phenotype, but the contribution of PECs was much greater. Telmisartan-receiving Tg26 mice (TRM) showed attenuated number of proliferating PECs-PGCs and TCs-PTCs compared with saline-receiving Tg26 mice (SRM). Similarly, TRM showed diminished expression of α-SMA and FSP1 by both PECs-PGCs and TCs-PTCs compared with SRM. We conclude that EMT contributes to the manifestation of the proliferative phenotype in HIVAN mice.

Three-dimensional Growth of Renal Epithelial Cells in Vitro: A Tool in Toxicity Testing

1993 ◽  
Vol 21 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Knut-Jan Andersen ◽  
Erik Ilsø Christensen ◽  
Hogne Vik
Keyword(s):  
Epithelial Cells ◽  
Three Dimensional ◽  
Toxicity Testing ◽  
Renal Tissue ◽  
Epithelial Cell Line ◽  
Multicellular Spheroids ◽  
Renal Epithelial Cell ◽  
Renal Epithelial Cells

The tissue culture of multicellular spheroids from the renal epithelial cell line LLC-PK1 (proximal tubule) is described. This represents a biological system of intermediate complexity between renal tissue in vivo and simple monolayer cultures. The multicellular structures, which show many similarities to kidney tubules in vivo, including a vectorial water transport, should prove useful for studying the potential nephrotoxicity of drugs and chemicals in vitro. In addition, the propagation of renal epithelial cells as multicellular spheroids in serum-free culture may provide information on the release of specific biological parameters, which may be suppressed or masked in serum-supplemented media.

scholarly journals c-Src inactivation reduces renal epithelial cell-matrix adhesion, proliferation, and cyst formation

2011 ◽  
Vol 301 (2) ◽  
pp. C522-C529 ◽  
Author(s):  
Justine Elliott ◽  
Nadezhda N. Zheleznova ◽  
Patricia D. Wilson
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Collecting Duct ◽  
Specific Inhibitor ◽  
Cell Phenotype ◽  
Epithelial Cell Proliferation ◽  
Matrix Adhesion ◽  
Cyst Lining

c-Src is a non-receptor tyrosine kinase whose activity is induced by phosphorylation at Y418 and translocation from the cytoplasm to the cell membrane. Increased activity of c-Src has been associated with cell proliferation, matrix adhesion, motility, and apoptosis in tumors. Immunohistochemistry suggested that activated (pY418)-Src activity is increased in cyst-lining autosomal dominant polycystic kidney disease (ADPKD) epithelial cells in human and mouse ADPKD. Western blot analysis showed that SKI-606 (Wyeth) is a specific inhibitor of pY418-Src without demonstrable effects on epidermal growth factor receptor or ErbB2 activity in renal epithelia. In vitro studies on mouse inner medullary collecting duct (mIMCD) cells and human ADPKD cyst-lining epithelial cells showed that SKI-606 inhibited epithelial cell proliferation over a 24-h time frame. In addition, SKI-606 treatment caused a striking statistically significant decrease in adhesion of mIMCD and human ADPKD to extracellular collagen matrix. Retained viability of unattached cells was consistent with a primary effect on epithelial cell anchorage dependence mediated by the loss of extracellular matrix (ECM)-attachment due to α2β1-integrin function. SKI-606-mediated attenuation of the human ADPKD hyperproliferative and hyper-ECM-adhesive epithelial cell phenotype in vitro was paralleled by retardation of the renal cystic phenotype of Pkd1 orthologous ADPKD heterozygous mice in vivo. This suggests that SKI-606 has dual effects on cystic epithelial cell proliferation and ECM adhesion and may have therapeutic potential for ADPKD patients.

Abstract 38: Rbp-j Regulates the Genetic Program of the Myo-epithelioid JG Cell

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Ruth M Castellanos Rivera ◽  
Ellen S. Pentz ◽  
Kenneth W. Gross ◽  
Silvia Medrano ◽  
Jing Yu ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Fluorescent Protein ◽  
Smooth Muscle Actin ◽  
Artificial Chromosome ◽  
Specific Protein ◽  
Genetic Program ◽  
Cell Phenotype ◽  
Gfp Expression ◽  
Renin Gene

RBP-J , the major downstream effector of Notch signaling, is necessary to maintain the number of juxtaglomerular (JG) cells. In addition, RBP-J regulates the plasticity of arteriolar smooth muscle cells to adopt the renin cell phenotype when homeostasis is threatened. We hypothesized that RBP-J acts as an on/off switch controlling the expression of genes that determine the renin phenotype. To determine whether RBP-J directly affects renin gene expression, we generated mice harboring a bacterial artificial chromosome (BAC) transgene with green fluorescent protein (GFP) under the control of the renin gene carrying a mutation in its RBP-J- binding site (Mut-BAC). Mut-BAC mice had markedly reduced GFP expression to 12.9 % ±0.01 (n=3) of the control (Wt-BAC) and a diminished response to homeostatic challenges: mut-BAC mice had a reduced number of GFP positive JG areas per total number of glomeruli (Wt-BAC: 25.1 % ±3.0, n=3; Mut-BAC: 9.3 % ±1.4, n=2, p<0.02) and no GFP expression along the arterioles. To determine whether the decrease in the number of JG cells in mice lacking RBP-J (cKO) was due to a diminished endowment of renin progenitor cells, we traced the fate of cells derived from the renin lineage by generating mice ( RBP-J fl/fl ; Ren1d +/cre ; R26R +/- ) in which cells lacking RBP-J simultaneously expressed β-galactosidase (β-gal). The pattern of β-gal in cKO and control kidneys was identical, indicating that cells derived from the renin lineage did not die but instead changed their phenotype. Next we investigated the phenotype adopted by the cells derived from the renin lineage. Expression of α-smooth muscle actin and smoothelin (a marker of mature smooth muscle) was significantly decreased to 41 % ±7.0 (n=2) and 44 % ±8.8 (n=2) respectively with respect to controls (p<0.01). In addition, mutant JG cells in vivo did not express genes characteristic of the renin phenotype such as renin, calponin1, Nfat and Akr1b7 expressing instead fibroblast-specific protein 1 indicating the adoption of a fibroblast-like phenotype. Results indicate that RBP-J directly governs a genetic program that controls the dual endocrine-contractile phenotype of the JG cell, which is crucial to maintain blood pressure and fluid-electrolyte homeostasis.

scholarly journals Thymic stromal lymphopoietin is released by human epithelial cells in response to microbes, trauma, or inflammation and potently activates mast cells

2007 ◽  
Vol 204 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Zoulfia Allakhverdi ◽  
Michael R. Comeau ◽  
Heidi K. Jessup ◽  
Bo-Rin Park Yoon ◽  
Avery Brewer ◽  
...  
Keyword(s):  
Mast Cells ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Immunoglobulin E ◽  
Interleukin 1 ◽  
Allergic Inflammation ◽  
Thymic Stromal Lymphopoietin ◽  
Microbial Products ◽  
Necrosis Factor

Compelling evidence suggests that the epithelial cell–derived cytokine thymic stromal lymphopoietin (TSLP) may initiate asthma or atopic dermatitis through a dendritic cell–mediated T helper (Th)2 response. Here, we describe how TSLP might initiate and aggravate allergic inflammation in the absence of T lymphocytes and immunoglobulin E antibodies via the innate immune system. We show that TSLP, synergistically with interleukin 1 and tumor necrosis factor, stimulates the production of high levels of Th2 cytokines by human mast cells (MCs). We next report that TSLP is released by primary epithelial cells in response to certain microbial products, physical injury, or inflammatory cytokines. Direct epithelial cell–mediated, TSLP-dependent activation of MCs may play a central role in “intrinsic” forms of atopic diseases and explain the aggravating role of infection and scratching in these diseases.

scholarly journals Central Role of the NF-κB Pathway in theScgb1a1-Expressing Epithelium in Mediating Respiratory Syncytial Virus-Induced Airway Inflammation

2018 ◽  
Vol 92 (11) ◽  
Author(s):  
Bing Tian ◽  
Jun Yang ◽  
Yingxin Zhao ◽  
Teodora Ivanciuc ◽  
Hong Sun ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Lower Respiratory Tract ◽  
Pol Ii ◽  
Neutrophilic Inflammation ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Epithelial Cell Population

ABSTRACTLower respiratory tract infection with respiratory syncytial virus (RSV) produces profound inflammation. Despite an understanding of the role of adaptive immunity in RSV infection, the identity of the major sentinel cells initially triggering inflammation is controversial. Here we evaluate the role of nonciliated secretoglobin (Scgb1a1)-expressing bronchiolar epithelial cells in RSV infection. Mice expressing a tamoxifen (TMX)-inducible Cre recombinase-estrogen receptor fusion protein (CreERTM) knocked into theScgb1a1locus were crossed with mice that harbor aRelAconditional allele (RelAfl), with loxP sites flanking exons 5 to 8 of the Rel homology domain. TheScgb1a1CreERTM/+× RelAfl/flmouse is aRelAconditional knockout (RelACKO) of a nonciliated epithelial cell population enriched in the small bronchioles. TMX-treated RelACKOmice have reduced pulmonary neutrophilic infiltration and impaired expression and secretion of NF-κB-dependent cytokines in response to RSV. In addition, RelACKOmice had reduced expression levels of interferon (IFN) regulatory factor 1/7 (IRF1/7) and retinoic acid-inducible gene I (RIG-I), components of the mucosal IFN positive-feedback loop. We demonstrate that RSV replication induces RelA to complex with bromodomain-containing protein 4 (BRD4), a cofactor required for RNA polymerase II (Pol II) phosphorylation, activating the atypical histone acetyltransferase (HAT) activity of BRD4 required for phospho-Ser2 Pol II formation, histone H3K122 acetylation, and cytokine secretionin vitroandin vivo. TMX-treated RelACKOmice have less weight loss and reduced airway obstruction/hyperreactivity yet similar levels of IFN-γ production despite higher levels of virus production. These data indicate that the nonciliatedScgb1a1-expressing epithelium is a major innate sensor for restricting RSV infection by mediating neutrophilic inflammation and chemokine and mucosal IFN production via the RelA-BRD4 pathway.IMPORTANCERSV infection is the most common cause of infant hospitalizations in the United States, resulting in 2.1 million children annually requiring medical attention. RSV primarily infects nasal epithelial cells, spreading distally to produce severe lower respiratory tract infections. Our study examines the role of a nonciliated respiratory epithelial cell population in RSV infection. We genetically engineered a mouse that can be selectively depleted of the NF-κB/RelA transcription factor in this subset of epithelial cells. These mice show an impaired activation of the bromodomain-containing protein 4 (BRD4) coactivator, resulting in reduced cytokine expression and neutrophilic inflammation. During the course of RSV infection, epithelial RelA-depleted mice have reduced disease scores and airway hyperreactivity yet increased levels of virus replication. We conclude that RelA-BRD4 signaling in nonciliated bronchiolar epithelial cells mediates neutrophilic airway inflammation and disease severity. This complex is an attractive target to reduce the severity of infection.

Role of f-box factor foxj1 in differentiation of ciliated airway epithelial cells

2004 ◽  
Vol 286 (4) ◽  
pp. L650-L657 ◽  
Author(s):  
Yingjian You ◽  
Tao Huang ◽  
Edward J. Richer ◽  
Jens-Erik Harboe Schmidt ◽  
Joseph Zabner ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Basal Body ◽  
Ciliated Cell ◽  
Airway Epithelial Cells ◽  
Cell Phenotype ◽  
Basal Bodies ◽  
Airway Epithelial ◽  
Ciliated Cells ◽  
Wild Type

Factors required for commitment of an undifferentiated airway epithelial cell to a ciliated cell are unknown. Cell ultrastructure analysis indicates ciliated cell commitment activates a multistage program involving synthesis of cilia precursor proteins and assembly of macromolecular complexes. Foxj1 is an f-box transcription factor expressed in ciliated cells and shown to be required for cilia formation by gene deletion in a mouse model. To identify a specific role for foxj1 in directing the ciliated cell phenotype, we evaluated the capacity of foxj1 to induce ciliogenesis and direct cilia assembly. In a primary culture model of wild-type mouse airway epithelial cells, foxj1 expression preceded the appearance of cilia and in cultured foxj1 null cells cilia did not develop. Delivery of foxj1 to polarized epithelial cell lines and primary cultured alveolar epithelial cells failed to promote ciliogenesis. Similarly, delivery of foxj1 to wild-type airway epithelial cells did not enhance the total number of ciliated cells. In contrast, delivery of foxj1 to null cells resulted in the appearance of cilia. Analysis revealed that, in the absence of foxj1, null cells contained cilia precursor basal bodies, indicating prior commitment to ciliogenesis. However, the basal bodies were disorganized within the apical compartment and failed to dock with the apical membrane. Reconstitution of foxj1 in null cells restored normal basal body organization, resulting in axoneme growth. Thus foxj1 functions in late-stage ciliogenesis to regulate programs promoting basal body docking and axoneme formation in cells previously committed to the ciliated cell phenotype.

scholarly journals Role of EGF Receptor Activation in Angiotensin II–Induced Renal Epithelial Cell Hypertrophy

2006 ◽  
Vol 17 (6) ◽  
pp. 1615-1623 ◽  
Author(s):  
Jianchun Chen ◽  
Jian-Kang Chen ◽  
Eric G. Neilson ◽  
Raymond C. Harris
Keyword(s):  
Angiotensin Ii ◽  
Epithelial Cell ◽  
Egf Receptor ◽  
Receptor Activation ◽  
Renal Epithelial Cell ◽  
Cell Hypertrophy

scholarly journals Use of Defined Mutants To Assess the Role of theCampylobacter rectus S-Layer in Bacterium-Epithelial Cell Interactions

2000 ◽  
Vol 68 (3) ◽  
pp. 1465-1473 ◽  
Author(s):  
Beinan Wang ◽  
Ellen Kraig ◽  
David Kolodrubetz
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Proinflammatory Cytokines ◽  
Transforming Growth Factor ◽  
Periodontal Diseases ◽  
Enzyme Linked Immunosorbent Assay ◽  
Minor Effect ◽  
Mrna Levels ◽  
Tnf Α

ABSTRACT Campylobacter rectus is a periodontal pathogen with a 150-kDa protein on its cell surface. This protein forms a paracrystalline lattice, called the S-layer, surrounding the outer membrane of this gram-negative bacterium. To initiate a genetic analysis of the possible role of the S-layer in the initial interaction of C. rectus with host epithelial cells, C. rectus strains lacking the S-layer protein gene (crsA) were constructed by allelic exchange mutagenesis. Surprisingly, the lack of the S-layer had only a minor effect on the interaction of C. rectus with HEp-2 epithelial cells; CrsA+ cells were 30 to 50% more adherent than were CrsA− bacteria. Since the host cell expression of cytokines appears to play an important role in the pathogenesis of periodontal diseases, the effect of the S-layer on the epithelial cell cytokine response was also examined by quantitative reverse transcriptase PCR and enzyme-linked immunosorbent assay. Although there were no changes in the mRNA levels for the anti-inflammatory cytokines interleukin-1 receptor agonist (IL-1ra), IL-13, and transforming growth factor β, the expression and secretion of the proinflammatory cytokines IL-6, IL-8, and tumor necrosis factor alpha (TNF-α) were significantly induced by both wild-type C. rectus and CrsA− bacteria. Interestingly, the kinetics of cytokine induction differed for the CrsA+ and CrsA−bacteria. At early time points, the HEp-2 cells challenged with CrsA− bacteria produced higher levels of IL-6, IL-8, and TNF-α mRNA and protein than did cells challenged with CrsA+ bacteria. We conclude that C. rectus may help initiate periodontitis by increasing the expression of proinflammatory cytokines and that the S-layer may temper this response to facilitate the survival of C. rectus at the site of infection.

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