Limits...
Mechanotransduction via TRPV4 regulates inflammation and differentiation in fetal mouse distal lung epithelial cells.

Nayak PS, Wang Y, Najrana T, Priolo LM, Rios M, Shaw SK, Sanchez-Esteban J - Respir. Res. (2015)

Bottom Line: Using the TRPV4 agonist GSK1016790A, the antagonist HC-067047, and the cytokine IL-6 as a marker of inflammation, we observed that TRPV4 regulates release of IL-6 via p38 and ERK pathways.Interestingly, stretch-induced differentiation of fetal epithelial cells was also modulated by TRPV4.These studies demonstrate that TRPV4 may play an important role in the transduction of mechanical signals in the fetal lung epithelium by modulating not only inflammation but also the differentiation of fetal epithelial cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Women and Infants Hospital of Rhode Island and the Warren Alpert Medical School of Brown University, 101 Dudley Street, Providence, RI, 02905, USA. pnayak4@gmail.com.

ABSTRACT

Background: Mechanical ventilation plays a central role in the injury of premature lungs. However, the mechanisms by which mechanical signals trigger an inflammatory cascade to promote lung injury are not well-characterized. Transient receptor potential vanilloid 4 (TRPV4), a calcium-permeable mechanoreceptor channel has been shown to be a major determinant of ventilator-induced acute lung injury in adult models. However, the role of these channels as modulators of inflammation in immature lungs is unknown. In this study, we tested the hypothesis that TRPV4 channels are important mechanotransducers in fetal lung injury.

Methods: Expression of TRPV4 in the mouse fetal lung was investigated by immunohistochemistry, Western blot and qRT-PCR. Isolated fetal epithelial cells were exposed to mechanical stimulation using the Flexcell Strain Unit and inflammation and differentiation were analyzed by ELISA and SP-C mRNA, respectively.

Results: TRPV4 is developmentally regulated in the fetal mouse lung; it is expressed in the lung epithelium and increases with advanced gestation. In contrast, in isolated epithelial cells, TRPV4 expression is maximal at E17-E18 of gestation. Mechanical stretch increases TRPV4 in isolated fetal epithelial cells only during the canalicular stage of lung development. Using the TRPV4 agonist GSK1016790A, the antagonist HC-067047, and the cytokine IL-6 as a marker of inflammation, we observed that TRPV4 regulates release of IL-6 via p38 and ERK pathways. Interestingly, stretch-induced differentiation of fetal epithelial cells was also modulated by TRPV4.

Conclusion: These studies demonstrate that TRPV4 may play an important role in the transduction of mechanical signals in the fetal lung epithelium by modulating not only inflammation but also the differentiation of fetal epithelial cells.

No MeSH data available.


Related in: MedlinePlus

Stretch-induced fetal epithelial cell differentiation is mediated via TRPV4. E17 epithelial cells were seeded on bioflex plates coated with laminin and then exposed to a physiologic 5 % cyclic stretch at 40 cycles/min for 24 h, in the presence or not of the TRPV4 agonist GSK1016790A [100 nM] or TRPV4 antagonist HC-067047 [1 μM]. Unstretched cells served as controls. RNA was extracted, as described in methods, and processed to assess SP-C mRNA abundance by qRT-PCR. Results are from 5 separate experiments. *P < 0.05 vs vehicle control; **P < 0.05 vs vehicle stretch; #P < 0.01 vs vehicle stretch. Tukey-Kramer Multiple Comparisons Test
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4446903&req=5

Fig6: Stretch-induced fetal epithelial cell differentiation is mediated via TRPV4. E17 epithelial cells were seeded on bioflex plates coated with laminin and then exposed to a physiologic 5 % cyclic stretch at 40 cycles/min for 24 h, in the presence or not of the TRPV4 agonist GSK1016790A [100 nM] or TRPV4 antagonist HC-067047 [1 μM]. Unstretched cells served as controls. RNA was extracted, as described in methods, and processed to assess SP-C mRNA abundance by qRT-PCR. Results are from 5 separate experiments. *P < 0.05 vs vehicle control; **P < 0.05 vs vehicle stretch; #P < 0.01 vs vehicle stretch. Tukey-Kramer Multiple Comparisons Test

Mentions: We finally addressed whether TRPV4 participates in stretch-induced differentiation of fetal epithelial cells. Previous studies from our laboratory have shown that 5 % cyclic stretch for 24 h upregulates surfactant protein-C (SP-C), a specific marker of type II cell differentiation [27]. To investigate whether this channel participates in the differentiation of epithelial cells mediated by stretch, monolayers were exposed to a physiologic 5 % stretch in the presence of specific TRPV4 agonist or antagonist. Our data in Fig. 6 show and as expected, mechanical stretch upregulated SP-C when compared to vehicle, control samples. The addition of the TRPV4 agonist GSK1016790A to the culture media did not affect SP-C in unstretched samples but increased SP-C mRNA by 44 % when compared to stretch samples without agonist (1.8 ± 0.09 vs 2.6 ± 0.22). In contrast, incubation of cells with the antagonist HC-067047 decreased SP-C mRNA by 54 % when compared to stretch vehicle (1.8 ± 0.09 vs 0.83 ± 0.1). The data suggest that TRPV4 participates in the differentiation of fetal epithelial cells mediated by stretch.Fig. 6


Mechanotransduction via TRPV4 regulates inflammation and differentiation in fetal mouse distal lung epithelial cells.

Nayak PS, Wang Y, Najrana T, Priolo LM, Rios M, Shaw SK, Sanchez-Esteban J - Respir. Res. (2015)

Stretch-induced fetal epithelial cell differentiation is mediated via TRPV4. E17 epithelial cells were seeded on bioflex plates coated with laminin and then exposed to a physiologic 5 % cyclic stretch at 40 cycles/min for 24 h, in the presence or not of the TRPV4 agonist GSK1016790A [100 nM] or TRPV4 antagonist HC-067047 [1 μM]. Unstretched cells served as controls. RNA was extracted, as described in methods, and processed to assess SP-C mRNA abundance by qRT-PCR. Results are from 5 separate experiments. *P < 0.05 vs vehicle control; **P < 0.05 vs vehicle stretch; #P < 0.01 vs vehicle stretch. Tukey-Kramer Multiple Comparisons Test
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4446903&req=5

Fig6: Stretch-induced fetal epithelial cell differentiation is mediated via TRPV4. E17 epithelial cells were seeded on bioflex plates coated with laminin and then exposed to a physiologic 5 % cyclic stretch at 40 cycles/min for 24 h, in the presence or not of the TRPV4 agonist GSK1016790A [100 nM] or TRPV4 antagonist HC-067047 [1 μM]. Unstretched cells served as controls. RNA was extracted, as described in methods, and processed to assess SP-C mRNA abundance by qRT-PCR. Results are from 5 separate experiments. *P < 0.05 vs vehicle control; **P < 0.05 vs vehicle stretch; #P < 0.01 vs vehicle stretch. Tukey-Kramer Multiple Comparisons Test
Mentions: We finally addressed whether TRPV4 participates in stretch-induced differentiation of fetal epithelial cells. Previous studies from our laboratory have shown that 5 % cyclic stretch for 24 h upregulates surfactant protein-C (SP-C), a specific marker of type II cell differentiation [27]. To investigate whether this channel participates in the differentiation of epithelial cells mediated by stretch, monolayers were exposed to a physiologic 5 % stretch in the presence of specific TRPV4 agonist or antagonist. Our data in Fig. 6 show and as expected, mechanical stretch upregulated SP-C when compared to vehicle, control samples. The addition of the TRPV4 agonist GSK1016790A to the culture media did not affect SP-C in unstretched samples but increased SP-C mRNA by 44 % when compared to stretch samples without agonist (1.8 ± 0.09 vs 2.6 ± 0.22). In contrast, incubation of cells with the antagonist HC-067047 decreased SP-C mRNA by 54 % when compared to stretch vehicle (1.8 ± 0.09 vs 0.83 ± 0.1). The data suggest that TRPV4 participates in the differentiation of fetal epithelial cells mediated by stretch.Fig. 6

Bottom Line: Using the TRPV4 agonist GSK1016790A, the antagonist HC-067047, and the cytokine IL-6 as a marker of inflammation, we observed that TRPV4 regulates release of IL-6 via p38 and ERK pathways.Interestingly, stretch-induced differentiation of fetal epithelial cells was also modulated by TRPV4.These studies demonstrate that TRPV4 may play an important role in the transduction of mechanical signals in the fetal lung epithelium by modulating not only inflammation but also the differentiation of fetal epithelial cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Women and Infants Hospital of Rhode Island and the Warren Alpert Medical School of Brown University, 101 Dudley Street, Providence, RI, 02905, USA. pnayak4@gmail.com.

ABSTRACT

Background: Mechanical ventilation plays a central role in the injury of premature lungs. However, the mechanisms by which mechanical signals trigger an inflammatory cascade to promote lung injury are not well-characterized. Transient receptor potential vanilloid 4 (TRPV4), a calcium-permeable mechanoreceptor channel has been shown to be a major determinant of ventilator-induced acute lung injury in adult models. However, the role of these channels as modulators of inflammation in immature lungs is unknown. In this study, we tested the hypothesis that TRPV4 channels are important mechanotransducers in fetal lung injury.

Methods: Expression of TRPV4 in the mouse fetal lung was investigated by immunohistochemistry, Western blot and qRT-PCR. Isolated fetal epithelial cells were exposed to mechanical stimulation using the Flexcell Strain Unit and inflammation and differentiation were analyzed by ELISA and SP-C mRNA, respectively.

Results: TRPV4 is developmentally regulated in the fetal mouse lung; it is expressed in the lung epithelium and increases with advanced gestation. In contrast, in isolated epithelial cells, TRPV4 expression is maximal at E17-E18 of gestation. Mechanical stretch increases TRPV4 in isolated fetal epithelial cells only during the canalicular stage of lung development. Using the TRPV4 agonist GSK1016790A, the antagonist HC-067047, and the cytokine IL-6 as a marker of inflammation, we observed that TRPV4 regulates release of IL-6 via p38 and ERK pathways. Interestingly, stretch-induced differentiation of fetal epithelial cells was also modulated by TRPV4.

Conclusion: These studies demonstrate that TRPV4 may play an important role in the transduction of mechanical signals in the fetal lung epithelium by modulating not only inflammation but also the differentiation of fetal epithelial cells.

No MeSH data available.


Related in: MedlinePlus