Squamous differentiation of primary cultures of tracheal epithelial cells

1991 ◽  
Vol 73 (2-3) ◽  
pp. 14a-14a
Author(s):  
Armelle Baeza ◽  
Sylvie Romet ◽  
Anne Moreau ◽  
Francelyne Marano
1987 ◽  
Vol 7 (11) ◽  
pp. 4017-4023 ◽  
Author(s):  
H L Smits ◽  
E E Floyd ◽  
A M Jetten

A cDNA library was constructed from polyadenylated RNA present in squamous differentiated rabbit tracheal epithelial cells. Screening of the cDNA library was aimed at identifying RNAs that were abundant in squamous cells and expressed at low levels in undifferentiated cells. Two different recombinants were obtained containing inserts, 0.86 and 0.77 kilobases (kb) in size, that hybridized to mRNAs 1.0 and 1.25 kb in length. These RNAs were present at approximately 50-fold higher levels in squamous cells than in proliferative or confluent retinoic acid-treated cells. The increase in the levels of the 1.0- and 1.25-kb RNAs correlated closely with the onset of squamous differentiation and was not related to induction of terminal cell division. Treatment of rabbit tracheal epithelial cells with transforming growth factor beta, which induces squamous differentiation in these cells, also resulted in elevated levels of the 1.0- and 1.25-kb RNAs. The increased levels of these RNAs in squamous cells appeared to a large extent to be regulated at a posttranscriptional level. Retinoic acid not only inhibited the increase in the levels of the 1.0- and 1.25-kb RNAs but also reversed the expression of these RNAs in squamous cells. These results suggest that retinoic acid affects, directly or indirectly, molecular events that induce alterations in the posttranscriptional processing of the transcripts corresponding to the 1.0- and 1.25-kb RNAs.


2000 ◽  
Vol 278 (3) ◽  
pp. L560-L571 ◽  
Author(s):  
Tomoko Suzuki ◽  
Mutsuo Yamaya ◽  
Kiyohisa Sekizawa ◽  
Norihiro Yamada ◽  
Katsutoshi Nakayama ◽  
...  

To examine the effects of glucocorticoid on rhinovirus (RV) infection, primary cultures of human tracheal epithelial cells were infected with either RV2 or RV14. Viral infection was confirmed by demonstrating that viral RNA in infected cells and viral titers of supernatants and lysates from infected cells increased with time. RV14 infection upregulated the expression of mRNA and protein of intercellular adhesion molecule-1 (ICAM-1), the major RV receptor, on epithelial cells, and it increased the production of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α in supernatants. Dexamethasone reduced the viral titers of supernatants and cell lysates, viral RNA of infected cells, and susceptibility of RV14 infection in association with inhibition of cytokine production and ICAM-1 induction. In contrast to RV14 infection, dexamethasone did not alter RV2 infection, a minor group of RVs. These results suggest that dexamethasone may inhibit RV14 infection by reducing the surface expression of ICAM-1 in cultured human tracheal epithelial cells. Glucocorticoid may modulate airway inflammation via reducing the production of proinflammatory cytokines and ICAM-1 induced by rhinovirus infection.


2000 ◽  
Vol 278 (6) ◽  
pp. L1264-L1272 ◽  
Author(s):  
Barbara Ressler ◽  
Richard T. Lee ◽  
Scott H. Randell ◽  
Jeffrey M. Drazen ◽  
Roger D. Kamm

Smooth muscle constriction in asthma causes the airway to buckle into a rosette pattern, folding the epithelium into deep crevasses. The epithelial cells in these folds are pushed up against each other and thereby experience compressive stresses. To study the epithelial cell response to compressive stress, we subjected primary cultures of rat tracheal epithelial cells to constant elevated pressures on their apical surface (i.e., a transmembrane pressure) and examined changes in the expression of genes that are important for extracellular matrix production and maintenance of smooth muscle activation. Northern blot analysis of RNA extracted from cells subjected to transmembrane pressure showed induction of early growth response-1 (Egr-1), endothelin-1, and transforming growth factor-β1 in a pressure-dependent and time-dependent manner. Increases in Egr-1 protein were detected by immunohistochemistry. Our results demonstrate that airway epithelial cells respond rapidly to compressive stresses. Potential transduction mechanisms of transmembrane pressure were also investigated.


1989 ◽  
Vol 9 (11) ◽  
pp. 4846-4851
Author(s):  
E E Floyd ◽  
A M Jetten

Squamous differentiation of rabbit tracheal epithelial cells is accompanied by an approximately 50-fold increase in the activity of type I (epidermal) transglutaminase, while the levels of type II (tissue) transglutaminase remain almost undetectable. To identify a cDNA encoding type I transglutaminase, we screened a library of cDNA clones prepared from poly(A)+ RNA isolated from squamous-differentiated rabbit tracheal epithelial cells. Four overlapping clones (represented by clone pTG-7) which span a range of 2.8 kilobases were identified; partial sequencing of pTG-7 indicated that it encodes a transglutaminaselike protein. pTG-7 hybridized to a 3.6-kilobase mRNA which is distinct from that for type II transglutaminase. pTG-7 mRNA levels were low in proliferative cells, increased dramatically in squamous-differentiated cells, and could be further enhanced by growth of the cells in high concentrations (2 mM) of calcium ions. Retinoic acid, which blocks the expression of the squamous phenotype, prevented this increase in pTG-7 mRNA levels. These changes in levels of pTG-7 mRNA parallel the changes in type I transglutaminase activity observed under similar culture conditions. These data indicate that pTG-7 encodes the mRNA for transglutaminase type I and that expression of this mRNA is negatively regulated by retinoic acid.


1987 ◽  
Vol 7 (11) ◽  
pp. 4017-4023
Author(s):  
H L Smits ◽  
E E Floyd ◽  
A M Jetten

A cDNA library was constructed from polyadenylated RNA present in squamous differentiated rabbit tracheal epithelial cells. Screening of the cDNA library was aimed at identifying RNAs that were abundant in squamous cells and expressed at low levels in undifferentiated cells. Two different recombinants were obtained containing inserts, 0.86 and 0.77 kilobases (kb) in size, that hybridized to mRNAs 1.0 and 1.25 kb in length. These RNAs were present at approximately 50-fold higher levels in squamous cells than in proliferative or confluent retinoic acid-treated cells. The increase in the levels of the 1.0- and 1.25-kb RNAs correlated closely with the onset of squamous differentiation and was not related to induction of terminal cell division. Treatment of rabbit tracheal epithelial cells with transforming growth factor beta, which induces squamous differentiation in these cells, also resulted in elevated levels of the 1.0- and 1.25-kb RNAs. The increased levels of these RNAs in squamous cells appeared to a large extent to be regulated at a posttranscriptional level. Retinoic acid not only inhibited the increase in the levels of the 1.0- and 1.25-kb RNAs but also reversed the expression of these RNAs in squamous cells. These results suggest that retinoic acid affects, directly or indirectly, molecular events that induce alterations in the posttranscriptional processing of the transcripts corresponding to the 1.0- and 1.25-kb RNAs.


2012 ◽  
Vol 56 (8) ◽  
pp. 4052-4061 ◽  
Author(s):  
Mutsuo Yamaya ◽  
Hidekazu Nishimura ◽  
Yukimasa Hatachi ◽  
Hiroyasu Yasuda ◽  
Xue Deng ◽  
...  

ABSTRACTRespiratory virus infections, including infections with rhinoviruses (RVs), are related to exacerbations of chronic obstructive pulmonary disease (COPD). A new quinolone antibiotic, levofloxacin (LVFX), has been used to treat bacterial infections that cause COPD exacerbations as well as bacterial infections that are secondary to viral infection in COPD patients. However, the inhibitory effects of LVFX on RV infection and RV infection-induced airway inflammation have not been studied. We examined the effects of LVFX on type 14 rhinovirus (RV14) (a major human RV) infection of human tracheal epithelial cells pretreated with LVFX. LVFX pretreatment reduced the RV14 titer, the level of cytokines in the supernatant, the amount of RV14 RNA in the cells after RV14 infection, and the cells' susceptibility to RV14 infection. LVFX pretreatment decreased the mRNA level of intercellular adhesion molecule 1 (ICAM-1), a receptor for RV14, in the cells and the concentration of the soluble form of ICAM-1 in the supernatant before RV14 infection. LVFX pretreatment also decreased the number and the fluorescence intensity of the acidic endosomes from which RV14 RNA enters the cytoplasm. LVFX pretreatment inhibited the activation of nuclear factor κB proteins, including p50 and p65, in nuclear extracts. LVFX pretreatment did not reduce the titers of RV2 (a minor human RV) but reduced the titers of RV15 (a major human RV). These results suggest that LVFX inhibits major-group rhinovirus infections in part by reducing ICAM-1 expression levels and the number of acidic endosomes. LVFX may also modulate airway inflammation in rhinoviral infections.


1993 ◽  
Vol 265 (3) ◽  
pp. L234-L242 ◽  
Author(s):  
S. R. White ◽  
K. S. Sigrist ◽  
S. M. Spaethe

We examined the effect of eosinophil major basic protein (MBP) on prostaglandin (PG) secretion from guinea pig tracheal epithelial (GPTE) cells. Primary cultures of GPTE cells were incubated with 10(-6) M MBP for up to 6 h and then stimulated with 10(-6) M bradykinin (BK). PGE2, 6-ketoprostaglandin F1 alpha (PGF1 alpha), PGF2 alpha, and thromboxane B2 (TxB2) concentrations in media were determined by enzyme-linked immunoabsorbent assay (EIA). Incubation with MBP for 6 h caused secretion of both PGE2 (17,614 +/- 4,416 vs. 1,426 +/- 555 pg/10(6) cells at baseline, P < 0.001, n = 7) and PGF2 alpha (20,303 +/- 5,724 vs. 3,790 +/- 1.075 pg/10(6) cells at baseline, P < 0.002, n = 7). Secretion of PGE2 and PGF2 alpha stimulated by MBP required at least 2 h. Incubation with MBP for 6 h also augmented the subsequent response to BK: PGE2 secretion was 29,215 +/- 6,853 vs. 3,445 +/- 1,041 pg/10(6) cells for BK alone (P < 0.0001), and PGF2 alpha secretion was 25,407 +/- 6,237 vs. 5,213 +/- 1,535 pg/10(6) cells for BK alone (P < 0.0001). MBP did not change 6-keto-PGF1 alpha and TxB2 secretion. Incubation of GPTE cells from seven animals with polylysine, a protein with mass and ion charge similar to MBP, for 2 h, both caused secretion of PGE2 (8,579 +/- 3,244 vs. 788 +/- 419 pg/10(6) cells at baseline, P < 0.01) and augmented the response to BK (12,732 +/- 4,788 vs. 1,653 +/- 680 pg/10(6) cells after BK alone, P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)


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