Functional characterization and localization of a gill-specific claudin isoform in Atlantic salmon.
AuthorsEngelund MB, Yu AS, Li J, Madsen SS, Færgeman NJ, Tipsmark CK
JournalAm J Physiol Regul Integr Comp Physiol
PubMed ID21975646
'Claudins are the major determinants of paracellular epithelial permeability in multicellular organisms. In Atlantic salmon (Salmo salar L.), we previously found that mRNA expression of the abundant gill-specific claudin 30 decreases during seawater (SW) acclimation, suggesting that this claudin is associated with remodeling of the epithelium during salinity change. This ... More
Polyamines are necessary for synthesis and stability of occludin protein in intestinal epithelial cells.
AuthorsGuo X, Rao JN, Liu L, Zou T, Keledjian KM, Boneva D, Marasa BS, Wang JY,
JournalAm J Physiol Gastrointest Liver Physiol
PubMed ID15691870
'Occludin is an integral membrane protein that forms the sealing element of tight junctions and is critical for epithelial barrier function. Polyamines are implicated in multiple signaling pathways driving different biological functions of intestinal epithelial cells (IEC). The present study determined whether polyamines are involved in expression of occludin and ... More
Claudin-1 has tumor suppressive activity and is a direct target of RUNX3 in gastric epithelial cells.
AuthorsChang TL, Ito K, Ko TK, Liu Q, Salto-Tellez M, Yeoh KG, Fukamachi H, Ito Y,
JournalGastroenterology
PubMed ID19706291
'The transcription factor RUNX3 is a gastric tumor suppressor. Tumorigenic Runx3(-/-) gastric epithelial cells attach weakly to each other, compared with nontumorigenic Runx3(+/+) cells. We aimed to identify RUNX3 target genes that promote cell-cell contact to improve our understanding of RUNX3''s role in suppressing gastric carcinogenesis. We compared gene expression ... More
Differences in claudin synthesis in primary cultures of acinar cells from rat salivary gland are correlated with the specific three-dimensional organization of the cells.
'Tight junctions are essential for the maintenance of epithelial cell polarity. We have previously established a system for the primary culture of salivary parotid acinar cells that retain their ability to generate new secretory granules and to secrete proteins in a signal-dependent manner. Because cell polarity and cell-cell adhesion are ... More
Differential effects of flavonoids on barrier integrity in human intestinal caco-2 cells.
AuthorsNoda S, Tanabe S, Suzuki T
JournalJ Agric Food Chem
PubMed ID22506771
'Flavonoids, present in fruits, vegetables, and teas, provide beneficial effects for our health. We investigated the effect of a number of flavonoids on tight junction (TJ) barrier integrity in human intestinal Caco-2 cells. Transepithelial electrical resistance (TER; a TJ integrity marker) across cell monolayers was measured in cells incubated with ... More
The Hedgehog pathway promotes blood-brain barrier integrity and CNS immune quiescence.
AuthorsAlvarez JI, Dodelet-Devillers A, Kebir H, Ifergan I, Fabre PJ, Terouz S, Sabbagh M, Wosik K, Bourbonnière L, Bernard M, van Horssen J, de Vries HE, Charron F, Prat A
JournalScience
PubMed ID22144466
'The blood-brain barrier (BBB) is composed of tightly bound endothelial cells (ECs) and perivascular astrocytes that regulate central nervous system (CNS) homeostasis. We showed that astrocytes secrete Sonic hedgehog and that BBB ECs express Hedgehog (Hh) receptors, which together promote BBB formation and integrity during embryonic development and adulthood. Using ... More
Distribution of tight junction proteins in adult human salivary glands.
AuthorsMaria OM, Kim JW, Gerstenhaber JA, Baum BJ, Tran SD
JournalJ Histochem Cytochem
PubMed ID18765838
'Tight junctions (TJs) are an essential structure of fluid-secreting cells, such as those in salivary glands. Three major families of integral membrane proteins have been identified as components of the TJ: claudins, occludin, and junctional adhesion molecules (JAMs), plus the cytosolic protein zonula occludens (ZO). We have been working to ... More
Leukocyte diapedesis in vivo induces transient loss of tight junction protein at the blood-retina barrier.
AuthorsXu H, Dawson R, Crane IJ, Liversidge J
JournalInvest Ophthalmol Vis Sci
PubMed ID15980240
Although much is now understood about the molecular structure of tight junctions (TJs), little is known about the regulation of their function during neural inflammatory disease processes in vivo. The mechanisms by which leukocytes transmigrate the blood-retina barrier (BRB) without affecting endothelial permeability are controversial. ... More
Knockdown of occludin expression leads to diverse phenotypic alterations in epithelial cells.
AuthorsYu AS, McCarthy KM, Francis SA, McCormack JM, Lai J, Rogers RA, Lynch RD, Schneeberger EE,
JournalAm J Physiol Cell Physiol
PubMed ID15689410
The function of occludin (Occ) in the tight junction is undefined. To gain insight into its role in epithelial cell biology, occludin levels in Madin-Darby canine kidney II cells were suppressed by stably expressing short interfering RNA. Suppression of occludin was associated with a decrease in claudins-1 and -7 and ... More
Differential expression of claudin tight junction proteins in the human cortical nephron.
AuthorsKirk A, Campbell S, Bass P, Mason J, Collins J
JournalNephrol Dial Transplant
PubMed ID20124215
In renal tubules, paracellular permeability is tightly controlled to facilitate solute absorption and urinary concentration and is regulated by tight junctions, which incorporate claudin proteins. There is very limited information confirming the localization of these proteins in the human renal cortex. Most data is inferred from mouse, bovine and rabbit ... More
Blood-testis barrier dynamics are regulated by testosterone and cytokines via their differential effects on the kinetics of protein endocytosis and recycling in Sertoli cells.
AuthorsYan HH, Mruk DD, Lee WM, Cheng CY,
JournalFASEB J
PubMed ID18192323
During spermatogenesis in the mammalian testis, preleptotene/leptotene spermatocytes differentiate from type B spermatogonia and traverse the blood-testis barrier (BTB) at stage VIII of the seminiferous epithelial cycle for further development. This timely movement of germ cells involves extensive junction restructuring at the BTB. Previous studies have shown that these events ... More
Inducible expression of Snail selectively increases paracellular ion permeability and differentially modulates tight junction proteins.
AuthorsCarrozzino F, Soulié P, Huber D, Mensi N, Orci L, Cano A, Féraille E, Montesano R,
JournalAm J Physiol Cell Physiol
PubMed ID15930145
Constitutive expression of the transcription factor Snail was previously shown to trigger complete epithelial-mesenchymal transition (EMT). The aim of this study was to determine whether inducible expression of Snail could modify epithelial properties without eliciting full mesenchymal conversion. For this purpose, we expressed mouse Snail (mSnail) cDNA in Madin-Darby canine ... More
Claudin-3 and claudin-4 expression in ovarian epithelial cells enhances invasion and is associated with increased matrix metalloproteinase-2 activity.
AuthorsAgarwal R, D'Souza T, Morin PJ,
JournalCancer Res
PubMed ID16103090
Claudin proteins form a large family of integral membrane proteins crucial for tight junction formation and function. Our previous studies have revealed that claudin-3 and claudin-4 proteins are highly overexpressed in ovarian cancer. To clarify the roles of claudins in ovarian tumorigenesis, we have generated human ovarian surface epithelial (HOSE) ... More
Minimal effects of VEGF and anti-VEGF drugs on the permeability or selectivity of RPE tight junctions.
AuthorsPeng S, Adelman RA, Rizzolo LJ,
JournalInvest Ophthalmol Vis Sci
PubMed ID20042644
Bevacizumab and ranibizumab are currently used to treat age-related macular degeneration by neutralizing vascular endothelial growth factor (VEGF). In this study, the potential side effects on the outer blood-retinal barrier were examined. Human fetal RPE (hfRPE) cells were used because they are highly differentiated in culture. The claudin composition of ... More
Inflammatory processes have differential effects on claudins 2, 3 and 4 in colonic epithelial cells.
AuthorsPrasad S, Mingrino R, Kaukinen K, Hayes KL, Powell RM, MacDonald TT, Collins JE,
JournalLab Invest
PubMed ID16007110
Claudin proteins comprise a recently described family of tight junction proteins that differentially regulate paracellular permeability. Since other tight junction proteins show alterations in distribution or expression in inflammatory bowel disease (IBD) we assessed expression of claudins (CL) 2, 3 and 4 in IBD. CL 2 was strongly expressed along ... More
Hypoxia increases transepithelial electrical conductance and reduces occludin at the plasma membrane in alveolar epithelial cells via PKC-? and PP2A pathway.
During pulmonary edema, the alveolar space is exposed to a hypoxic environment. The integrity of the alveolar epithelial barrier is required for the reabsorption of alveolar fluid. Tight junctions (TJ) maintain the integrity of this barrier. We set out to determine whether hypoxia creates a dysfunctional alveolar epithelial barrier, evidenced ... More
Differential distribution of tight junction proteins suggests a role for tanycytes in blood-hypothalamus barrier regulation in the adult mouse brain.
AuthorsMullier A, Bouret SG, Prevot V, Dehouck B,
JournalJ Comp Neurol
PubMed ID20127760
The median eminence is one of the seven so-called circumventricular organs. It is located in the basal hypothalamus, ventral to the third ventricle and adjacent to the arcuate nucleus. This structure characteristically contains a rich capillary plexus and features a fenestrated endothelium, making it a direct target of blood-borne molecules. ... More
Claudin-1, -2, -3, -4, -7, -8, and -10 protein expression in biliary tract cancers.
AuthorsNémeth Z, Szász AM, Tátrai P, Németh J, Gyorffy H, Somorácz A, Szíjártó A, Kupcsulik P, Kiss A, Schaff Z,
JournalJ Histochem Cytochem
PubMed ID18854598
Biliary tract cancers are relatively common malignant gastrointestinal tumors in the elderly. Claudins are integral components of tight junctions that play important roles in maintaining epithelial cell polarity, controlling paracellular diffusion, and regulating cell growth and differentiation. The expression profile of claudins has been extensively characterized, but few reports exist ... More
Complexity and developmental changes in the expression pattern of claudins at the blood-CSF barrier.
AuthorsKratzer I, Vasiljevic A, Rey C, Fevre-Montange M, Saunders N, Strazielle N, Ghersi-Egea JF,
JournalHistochem Cell Biol
PubMed ID22886143
The choroid plexus epithelium controls the movement of solutes between the blood and the cerebrospinal fluid. It has been considered as a functionally more immature interface during brain development than in adult. The anatomical basis of this barrier is the interepithelial choroidal junction whose tightness has been attributed to the ... More
Allogeneic human mesenchymal stem cells restore epithelial protein permeability in cultured human alveolar type II cells by secretion of angiopoietin-1.
AuthorsFang X, Neyrinck AP, Matthay MA, Lee JW,
JournalJ Biol Chem
PubMed ID20554518
Acute lung injury is characterized by injury to the lung epithelium that leads to impaired resolution of pulmonary edema and also facilitates accumulation of protein-rich edema fluid and inflammatory cells in the distal airspaces of the lung. Recent in vivo and in vitro studies suggest that mesenchymal stem cells (MSC) ... More
Effects of proinflammatory cytokines on the claudin-19 rich tight junctions of human retinal pigment epithelium.
AuthorsPeng S, Gan G, Rao VS, Adelman RA, Rizzolo LJ,
JournalInvest Ophthalmol Vis Sci
PubMed ID22761260
Chronic, subclinical inflammation contributes to the pathogenesis of several ocular diseases, including age-related macular degeneration. Proinflammatory cytokines affect tight junctions in epithelia that lack claudin-19, but in the retinal pigment epithelium claudin-19 predominates. We examined the effects of cytokines on the tight junctions of human fetal RPE (hfRPE). hfRPE was ... More
Paracellular Cl- permeability is regulated by WNK4 kinase: insight into normal physiology and hypertension.
AuthorsKahle KT, Macgregor GG, Wilson FH, Van Hoek AN, Brown D, Ardito T, Kashgarian M, Giebisch G, Hebert SC, Boulpaep EL, Lifton RP,
JournalProc Natl Acad Sci U S A
PubMed ID15465913
Paracellular ion flux across epithelia occurs through selective and regulated pores in tight junctions; this process is poorly understood. Mutations in the kinase WNK4 cause pseudohypoaldosteronism type II (PHAII), a disease featuring hypertension and hyperkalemia. Whereas WNK4 is known to regulate several transcellular transporters and channels involved in NaCl and ... More
Cultured monolayers of the dog jejunum with the structural and functional properties resembling the normal epithelium.
AuthorsWeng XH, Beyenbach KW, Quaroni A,
JournalAm J Physiol Gastrointest Liver Physiol
PubMed ID15550553
The development of a culture of the normal mammalian jejunum motivated this work. Isolated crypt cells of the dog jejunum were induced to form primary cultures on Snapwell filters. Up to seven subcultures were studied under the electron microscope and in Ussing chambers. Epithelial markers were identified by RT-PCR, Western ... More
Enhanced immunohistochemical resolution of claudin proteins in glycolmethacrylate-embedded tissue biopsies.
AuthorsCollins JE, Kirk A, Campbell SK, Mason J, Wilson SJ,
JournalMethods Mol Biol
PubMed ID21717371
There are a number of disadvantages with conventional tissue immunohistochemistry for accurate -localisation of claudin proteins. Traditionally, tissue cryopreservation or formaldehyde fixation with wax embedding is utilised prior to sectioning and antibody localisation. Wax embedding gives better morphological preservation than frozen tissue, but the required use of chemical cross-linking fixatives ... More
Transmigration of neural stem cells across the blood brain barrier induced by glioma cells.
AuthorsDíaz-Coránguez M, Segovia J, López-Ornelas A, Puerta-Guardo H, Ludert J, Chávez B, Meraz-Cruz N, González-Mariscal L,
JournalPLoS One
PubMed ID23637756
Transit of human neural stem cells, ReNcell CX, through the blood brain barrier (BBB) was evaluated in an in vitro model of BBB and in nude mice. The BBB model was based on rat brain microvascular endothelial cells (RBMECs) cultured on Millicell inserts bathed from the basolateral side with conditioned ... More
Two strikingly different signaling pathways are induced by meningococcal type IV pili on endothelial and epithelial cells.
AuthorsLécuyer H, Nassif X, Coureuil M
JournalInfect Immun
PubMed ID22064711
Following adhesion on brain microvasculature, Neisseria meningitidis is able to cross the blood-brain barrier (BBB) by recruiting the polarity complex and the cell junction proteins, thus allowing the opening of the paracellular route. This feature is the consequence of the activation by the type IV pili of the ß2-adrenergic receptor/ß-arrestin ... More