Novel non-TGF-β-binding splice variant of LTBP-4 in human cells and tissues provides means to decrease TGF-β deposition

2001 ◽  
Vol 114 (15) ◽  
pp. 2869-2878
Author(s):  
Katri Koli ◽  
Juha Saharinen ◽  
Mira Kärkkäinen ◽  
Jorma Keski-Oja
Keyword(s):  
Extracellular Matrix ◽  
Splice Variant ◽  
Noncovalent Interactions ◽  
Repetitive Sequences ◽  
Lung Fibroblasts ◽  
Rt Pcr ◽  
Human Embryonic Lung ◽  
Structural Functions ◽  
Intron Structure ◽  
Alternatively Spliced

Small latent TGF-β consists of latency associated peptide (LAP) bound to the 25 kDa TGF-β by noncovalent interactions. Small latent TGF-β is secreted from cells and deposited into the extracellular matrix as covalent complexes with its binding proteins, LTBPs. Four LTBPs have been molecularly cloned and their structures contain repetitive sequences. The 3rd 8-Cys repeats of LTBP-1, -3 and -4 are able to associate with small latent TGF-β. We analyzed by RT-PCR the expression of LTBPs 1-4 in a panel of cultured human cell lines including fibroblasts of different origin, endothelial cells and immortalized keratinocytes. LTBPs were expressed in an overlapping manner, but differences in their expression levels were detected. SV-40 transformed human embryonic lung fibroblasts contained less of the mRNAs for the LTBPs, suggesting that malignant transformation leads to decrease in LTBP expression. A novel alternatively spliced form of LTBP-4 lacking the 3rd 8-Cys repeat (LTBP-4Δ8-Cys3rd) was identified. LTBP-4Δ8-Cys3rd does not bind TGF-β and it was found to be expressed in the same tissues as the full length LTBP-4. The exon-intron structure of LTBP-4 around the 3rd 8-Cys repeat was similar to those of LTBP-2 and -3. LTBP-4Δ8-Cys3rd was produced by alternative splicing over two exons. In addition, HL-60 promyelocytic leukemia cells expressed a splice variant lacking only one exon of this region. The expression of the non-TGF-β-binding variant of LTBP-4 may be important for the regulation of TGF-β deposition in tissues. Since LTBPs are a part of the extracellular matrix microfibrils, the LTBP-4Δ8-Cys3rd protein may also be involved in various structural functions not related to TGF-β signaling.

scholarly journals Binding and degradation of platelet thrombospondin by cultured fibroblasts.

1984 ◽  
Vol 98 (1) ◽  
pp. 22-28 ◽  
Author(s):  
P J McKeown-Longo ◽  
R Hanning ◽  
D F Mosher
Keyword(s):  
Extracellular Matrix ◽  
Cell Layer ◽  
Extracellular Fluid ◽  
Human Platelets ◽  
Lung Fibroblasts ◽  
Human Embryonic Lung ◽  
Cultured Fibroblasts ◽  
The Matrix ◽  
Specific Receptors ◽  
Or Organization

Thrombospondin was purified from human platelets and labeled with 125I, and its metabolism was quantified in cell cultures of human embryonic lung fibroblasts. 125I-Thrombospondin bound to the cell layer. The binding reached an apparent steady state within 45 min. Trichloroacetic acid-soluble radioactivity was detected in the medium after 30 min of incubation; the rate of degradation of 125I-thrombospondin was linear for several hours thereafter. Degradation of 125I-thrombospondin was saturable. The apparent Km and Vmax for degradation at 37 degrees C were 6 X 10(-8) M and 1.4 X 10(5) molecules per cell per minute, respectively. Degradation was inhibited by chloroquine or by lowering the temperature to 4 degrees C. Experiments in which cultures were incubated with thrombospondin for 45 min and then incubated in medium containing no thrombospondin revealed two fractions of bound thrombospondin. One fraction was localized by indirect immunofluorescence to punctate structures; these structures were lost coincident with the rapid degradation of 50-80% of bound 125I-thrombospondin. The second fraction was localized to a trypsin-sensitive, fibrillar, extracellular matrix. 125I-Thrombospondin in the matrix was slowly degraded over a period of hours. Binding of 125I-thrombospondin to the extracellular matrix was not saturable and indeed was enhanced at thrombospondin concentrations greater than 3 X 10(-8) M. The ability of 125I-thrombospondin to bind to extracellular matrix was diminished tenfold by limited proteolytic cleavage with trypsin. Degradation of trypsinized 125I-thrombospondin was also diminished, although to a lesser extent than matrix binding. Heparin inhibited both degradation and matrix binding. These results suggest that thrombospondin may play a transitory role in matrix formation and/or organization and that specific receptors on the cell surface are responsible for the selective removal of thrombospondin from the extracellular fluid and matrix.

scholarly journals MORPHOGENETIC ASPECTS OF MULTILAYERING IN PETRI DISH CULTURES OF HUMAN FETAL LUNG FIBROBLASTS

1969 ◽  
Vol 41 (1) ◽  
pp. 298-311 ◽  
Author(s):  
Tom Elsdale ◽  
Robert Foley
Keyword(s):  
Extracellular Matrix ◽  
Human Lung ◽  
Petri Dish ◽  
Fetal Lung ◽  
Single Species ◽  
Lung Fibroblasts ◽  
Human Lung Fibroblasts ◽  
Spontaneous Aggregation ◽  
Control Hypothesis ◽  
Human Fetal Lung

Randomly seeded Petri dish cultures of embryonic human lung fibroblasts generate, in the course of their growth, highly ordered cellular arrangements. Thick, bilaterally symmetrical ridges with an axial polarity and an orthogonal, multilayered internal organization are observed within stationary cultures. The generation of these structures has been investigated. Ridges result from the spontaneous aggregation of cells in postconfluent cultures brought about by directed cell movements. These movements are promoted by the localized production of extracellular matrix sheets containing collagen, which provide new substrates for cellular colonization. Cells that have colonized one matrix substrate may secrete another above themselves, which will in turn be colonized. By a continuation of this cycle, thick stacks consisting of alternate layers of cells and matrix are produced to yield the observed aggregations. The distribution and shape of ridges in a culture imply that matrix substrates are confined to specific locations. The suggested control hypothesis assumes that all the cells in fibroblast cultures are potential producers of a single species of matrix. The serviceability of this matrix as a substrate for cellular colonization, however, is destroyed if the producer cells are motile. Matrix substrates, therefore, are only made by nonmotile cells.

Latent TGF-beta binding protein LTBP-1 contains three potential extracellular matrix interacting domains

2001 ◽  
Vol 114 (1) ◽  
pp. 187-197 ◽  
Author(s):  
C. Unsold ◽  
M. Hyytiainen ◽  
L. Bruckner-Tuderman ◽  
J. Keski-Oja
Keyword(s):  
Extracellular Matrix ◽  
Expression System ◽  
Covalent Binding ◽  
Sodium Deoxycholate ◽  
Current Data ◽  
Lung Fibroblasts ◽  
Tgf Beta ◽  
Mammalian Expression ◽  
The Matrix ◽  
Recombinant Fragments

Latent TGF-beta binding proteins (LTBPs) are components of the extracellular matrix (ECM). They belong to the fibrillin/LTBP-superfamily, and are high molecular weight glycoproteins characterized by EGF-like repeats and 8-Cys repeats. Most LTBPs associate with the small latent forms of TGF-beta. Their roles include to facilitate the secretion of latent TGF-beta and to target it to the ECM. In order to identify new matrix-binding domains of LTBP-1 and to characterize their association with the extracellular matrix, we have produced (in a mammalian expression system) partly overlapping recombinant fragments of its shorter form, LTBP-1S, and analyzed the binding of the purified fusion proteins to extracellular matrices of cultured human dermal and lung fibroblasts. Recombinant fragments from three different regions of the N- and C-termini showed affinity to the matrix. These interacting regions contain either the first (hybrid), second or fourth 8-Cys domains of the LTBP-1S molecule. They bound independently to the matrix. Each of them had an ability to inhibit the association of native exogenous LTBP-1 with fibroblast extracellular matrix. The interactions of the LTBP-1 fragments with the extracellular matrix resisted treatment with sodium deoxycholate, suggesting strong, possibly covalent binding. The binding occurred in a time- and dose-dependent fashion. The N-terminal fragments bound more readily to the matrices. With all fragments the binding took place both with intact fibroblast matrices and with matrices isolated by sodium deoxycholate. When using CHO cell layers, which form sparse matrices, only the N-terminal fragment of LTBP-1 was efficiently incorporated. The association of the binding fragments with isolated matrices was enhanced by soluble, cell-derived factors. The current data suggest that LTBP-1 contains three different domains with an ability to associate with the extracellular matrix.

Genotoxic Effect of a New Water-Soluble Fullerene Derivative C70 and its Effect on the Transcriptional Activity of Genes that Regulate the Cell Cycle, DNA Repair and Apoptosis

2021 ◽  
Vol 1031 ◽  
pp. 222-227
Author(s):  
Ekaterina A. Savinova ◽  
Elizaveta S. Ershova ◽  
Olga A. Kraevaya ◽  
Pavel A. Troshin ◽  
S.V. Kostyuk
Keyword(s):  
Cell Cycle ◽  
Transcriptional Activity ◽  
Water Soluble ◽  
Lung Fibroblasts ◽  
Fullerene Derivative ◽  
Embryonic Lung ◽  
Dna Breaks ◽  
Human Embryonic Lung ◽  
Fullerene Derivatives ◽  
Cellular Dna

It is important to take into consideration the new fullerene derivatives genotoxicity. In the present is study, we analyzed the new water-soluble fullerene C70 (F350) effects on the human embryonic lung fibroblasts (HELF) oxidative damage and DNA breaks. We found that the studied compound causes cellular DNA damage and affects the transcriptional activity of cell cycle and cell apoptosis regulating genes.

scholarly journals The Mouse Testis Is the Source of Various Serine Proteases and Serine Proteinase Inhibitors (SERPINs): Serine Proteases and SERPINs Identified in Leydig Cells Are under Gonadotropin Regulation

Endocrinology ◽  
2006 ◽  
Vol 147 (9) ◽  
pp. 4374-4383 ◽  
Author(s):  
Fanny Odet ◽  
Adélie Verot ◽  
Brigitte Le Magueresse-Battistoni
Keyword(s):  
Extracellular Matrix ◽  
Plasminogen Activator ◽  
Serine Proteases ◽  
Leydig Cells ◽  
Proteinase Inhibitors ◽  
Primary Cultures ◽  
Serine Proteinases ◽  
Rt Pcr ◽  
Positive Effects ◽  
Extracellular Matrix Components

The occurrence of various serine proteinases and serine proteinases inhibitors (SERPINs) was investigated by RT-PCR in whole testes of 1-, 3-, and 8-wk-old mice in crude and enriched germ cell fractions, mouse Leydig tumor cells (mLTC-1), and primary cultures of 3- and 8-wk-old enriched fractions of Leydig cells and 3-wk-old Sertoli cells. New members were identified in the testis protease repertoire. Within the Leydig repertoire, a PCR product was found for plasminogen activators urokinase plasminogen activator (uPA) and tissue plasminogen activator (8-wk-old cells), matriptase-2 (mLTC-1), kallikrein-21, SERPINA5, SERPINB2 (primary cultures), and serine peptidase inhibitor Kunitz type 2 (SPINT2). The gonadotropin regulation was explored by semiquantitative RT-PCR, using steroidogenic acute regulatory protein (StAR) as a positive control. Matriptase-2, kallikrein-21, SPINT2, and SERPINA5 were down-regulated, whereas uPA and its receptor were up-regulated by human chorionic gonadotropin (hCG) via cAMP in the mLTC-1 cells. Positive effects were observed transiently after 1–8 h of hCG exposure, and negative effects, first evidenced after 6 h, lasted 48 h. The hCG-induced effects were confirmed in primary cultures. In addition, SERPINB2 was augmented by hCG in primary cultures. Addition of either trypsin or protease inhibitors did not alter the hCG-induced surge of StAR. Because hCG regulated proteases and SERPINs (whereas testosterone did not), it could alter the proteolytic balance of Leydig cells and consequently the metabolism of extracellular matrix components. Therefore, even though a direct interplay between the early hCG-induced surge of uPA and StAR is unlikely, our data together with the literature suggest that extracellular matrix proteins alter Leydig cell steroidogenesis.

scholarly journals Amplified canonical transforming growth factor-β signalling via heat shock protein 90 in pulmonary fibrosis

2016 ◽  
Vol 49 (2) ◽  
pp. 1501941 ◽  
Author(s):  
Zaneta Sibinska ◽  
Xia Tian ◽  
Martina Korfei ◽  
Baktybek Kojonazarov ◽  
Janina Susanne Kolb ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Growth Factor ◽  
Pulmonary Fibrosis ◽  
Transforming Growth Factor ◽  
A549 Cells ◽  
Lung Fibroblasts ◽  
Hsp90 Inhibition ◽  
Extracellular Matrix Production ◽  
Matrix Production ◽  
Β Receptor

Interstitial lung fibroblast activation coupled with extracellular matrix production is a pathological signature of idiopathic pulmonary fibrosis (IPF), and is governed by transforming growth factor (TGF)-β/Smad signalling. We sought to define the role of heat shock protein (HSP)90 in profibrotic responses in IPF and to determine the therapeutic effects of HSP90 inhibition in a murine model of pulmonary fibrosis.We investigated the effects of HSP90 inhibition in vitro by applying 17-AAG (17-allylamino-17-demethoxygeldanamycin) to lung fibroblasts and A549 cells and in vivo by administering 17-DMAG (17-dimethylaminoethylamino-17-demethoxygeldanamycin) to mice with bleomycin-induced pulmonary fibrosis.HSP90 expression was increased in (myo)fibroblasts from fibrotic human and mouse lungs compared with controls. 17-AAG inhibited TGF-β1-induced extracellular matrix production and transdifferentiation of lung fibroblasts and epithelial–mesenchymal transition of A549 cells. The antifibrotic effects were associated with TGF-β receptor disruption and inhibition of Smad2/3 activation. Co-immunoprecipitation revealed that HSP90β interacted with TGF-β receptor II and stabilised TGF-β receptors. Furthermore, 17-DMAG improved lung function and decreased fibrosis and matrix metalloproteinase activity in the lungs of bleomycin-challenged mice.In conclusion, this is the first study to demonstrate that HSP90 inhibition blocks pulmonary fibroblast activation and ameliorates bleomycin-induced pulmonary fibrosis in mice.

Tenascin in rat lung development: in situ localization and cellular sources

1995 ◽  
Vol 269 (4) ◽  
pp. L482-L491 ◽  
Author(s):  
Y. Zhao ◽  
S. L. Young
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Lung Tissue ◽  
Lung Development ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Rat Lung ◽  
Alveolar Epithelial

Tenascin (TN) is a hexameric extracellular matrix glycoprotein that may play an important role during lung development. TN protein is temporally and spatially restricted during lung organogenesis. The temporo-spatial and cellular expression of TN mRNA in lung remains unclear. Localization of message expression of TN in rat lung tissue was first investigated by using in situ hybridization performed with an antisense RNA probe. TN mRNA was present primarily within the mesenchyme of day 16 gestational age fetal rat lung tissue, whereas immunoreactive TN protein was found along the basement membrane. In postnatal day 3 rat lung tissue, TN mRNA was detected along alveolar septal walls and was concentrated at secondary septal tips. Expression of TN message was consistent with localization of immunoreactive TN protein. Accumulation of TN mRNA in alveolar septal tips suggests that mesenchyme may be the major source of TN mRNA. To investigate the cellular source of TN in rat lung, we studied the expression of TN in cultured rat lung fibroblasts, endothelial cells, and alveolar epithelial cells. Two TN isoforms having molecular mass of 230 and 180 kDa were in conditioned medium and in cellular extracts of lung fibroblasts and endothelial cells. TN was secreted and deposited in the extracellular matrix closely associated with the surface of lung fibroblasts and endothelial cells. Lung alveolar epithelial cells showed undetectable or barely detectable amounts of TN. These studies demonstrated that TN isoforms are expressed not only by lung fibroblasts but also by lung endothelial cells. The unique spatial localization of TN mRNA during lung development and expression of TN by different lung cell types suggested TN may be involved in matrix organization and cell-cell interactions during lung development.

scholarly journals Ca2+-ATPase protein expression in mammary tissue

2000 ◽  
Vol 279 (5) ◽  
pp. C1595-C1602 ◽  
Author(s):  
Timothy A. Reinhardt ◽  
Adelaida G. Filoteo ◽  
John T. Penniston ◽  
Ronald L. Horst
Keyword(s):  
Protein Expression ◽  
Milk Fat ◽  
Secretory Pathway ◽  
Apical Membrane ◽  
Mammary Tissue ◽  
Splice Form ◽  
Rt Pcr ◽  
Milk Fat Globule ◽  
Alternatively Spliced ◽  
Fat Globule

Protein expression of plasma membrane Ca2+-ATPases (PMCAs) and the putative Golgi secretory pathway Ca2+-ATPase (SPCA) was examined in rat mammary tissue. As lactation started, PMCA protein expression increased dramatically, and this increased expression paralleled milk production. Mammary PMCA was primarily PMCA2b but was ∼4,000 daltons larger than expected. RT-PCR showed that the primary mammary PMCA2b transcript was alternatively spliced, at splice site A, to include an additional 135 bp, resulting in the insertion of 45 amino acids. This splice form is designated 2bw. PMCA2bw is secreted into milk, associated with the milk fat globule membrane. Therefore, PMCA2bw is located on the apical membrane of the secretory cell. Smaller amounts of PMCA1b and 4b protein were found in mammary tissue. PMCA4b was the major PMCA expressed in developing tissue, and its level declined as lactation started. PMCA1b expression increased moderately during lactation. SPCA protein expression increased 1 wk before parturition and increased further as lactation proceeded. The abundance and cell location of PMCA2b suggest that it is important for macro-Ca2+ homeostasis in lactating tissue. The pattern of expression and abundance of SPCA suggest that it is a candidate for the Golgi Ca2+-ATPase.

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