Limits...
TRPV1 in Salivary Gland Epithelial Cells Is Not Involved in Salivary Secretion via Transcellular Pathway.

Choi S, Shin YH, Namkoong E, Hwang SM, Cong X, Yu G, Park K - Korean J. Physiol. Pharmacol. (2014)

Bottom Line: However, capsaicin (CAP), TRPV1 agonist, had little effect on intracellular free calcium concentration ([Ca(2+)]i) in these cells, although carbachol consistently increased [Ca(2+)]i.Saliva flow rate also showed insignificant change in the mice treated with PILO plus CAP compared with that in mice treated with PILO alone.Taken together, our results suggest that although TRPV1 is expressed in SGEC, it appears not to play any direct roles in saliva secretion via transcellular pathway.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, Korea.

ABSTRACT
Transient receptor potential vanilloid subtype 1 (TRPV1) was originally found in sensory neurons. Recently, it has been reported that TRPV1 is expressed in salivary gland epithelial cells (SGEC). However, the physiological role of TRPV1 in salivary secretion remains to be elucidated. We found that TRPV1 is expressed in mouse and human submandibular glands (SMG) and HSG cells, originated from human submandibular gland ducts at both mRNA and protein levels. However, capsaicin (CAP), TRPV1 agonist, had little effect on intracellular free calcium concentration ([Ca(2+)]i) in these cells, although carbachol consistently increased [Ca(2+)]i. Exposure of cells to high temperature (>43℃) or acidic bath solution (pH5.4) did not increase [Ca(2+)]i, either. We further examined the role of TRPV1 in salivary secretion using TRPV1 knock-out mice. There was no significant difference in the pilocarpine (PILO)-induced salivary flow rate between wild-type and TRPV1 knock-out mice. Saliva flow rate also showed insignificant change in the mice treated with PILO plus CAP compared with that in mice treated with PILO alone. Taken together, our results suggest that although TRPV1 is expressed in SGEC, it appears not to play any direct roles in saliva secretion via transcellular pathway.

No MeSH data available.


Related in: MedlinePlus

Distribution of TRPV1 in salivary gland epithelial cells (SGEC). Representative immunofluorescence labeling of TRPV1 in mSMG (A), hSMG (B), and HSG cells (C). SMGs sections and HSG were immunostained with anti-TRPV1 antibody and AQP5 antibody, then incubated with Alexa Fluor-linked anti-rabbit IgG (red) and Alexa Fluor-linked anti-goat IgG (green). Nuclei (blue) were labeled with 4,6-diamidino-2-phenylindole. (A) TRPV1were mainly detected in apical membrane in acinar cells and in basolateral membrane in ductal cells. AQP5 was used as a marker for acinar cells that was exclusively expressed in the apical membrane of acinar cells (red color). The merged orange color indicates that expression of TRPV1 at the apical membrane in acinar cells. (B) In hSMG, higher expression levels of TRPV1 was observed in ductal cells compared to acinar cells. (C) In HSG cells, TRPV1 was widespread in the cytoplasm. Scale bar indicates 20 µm. The results are representative of four independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4296043&req=5

Figure 2: Distribution of TRPV1 in salivary gland epithelial cells (SGEC). Representative immunofluorescence labeling of TRPV1 in mSMG (A), hSMG (B), and HSG cells (C). SMGs sections and HSG were immunostained with anti-TRPV1 antibody and AQP5 antibody, then incubated with Alexa Fluor-linked anti-rabbit IgG (red) and Alexa Fluor-linked anti-goat IgG (green). Nuclei (blue) were labeled with 4,6-diamidino-2-phenylindole. (A) TRPV1were mainly detected in apical membrane in acinar cells and in basolateral membrane in ductal cells. AQP5 was used as a marker for acinar cells that was exclusively expressed in the apical membrane of acinar cells (red color). The merged orange color indicates that expression of TRPV1 at the apical membrane in acinar cells. (B) In hSMG, higher expression levels of TRPV1 was observed in ductal cells compared to acinar cells. (C) In HSG cells, TRPV1 was widespread in the cytoplasm. Scale bar indicates 20 µm. The results are representative of four independent experiments.

Mentions: We then studied location of TRPV1 using confocal microscopy. Fig. 2A shows TRPV1 proteins in mSMG (green color). TRPV1 was mainly detected at the apical membrane in acinar cells and at the basolateral membrane in ductal cells. We used AQP5 as a marker for acinar cells that was exclusively expressed in the apical membrane of acinar cells (red color). Thus, the merged orange color in Fig. 2A indicates that expression of TRPV1 at the apical membrane in acinar cells. In hSMG, TRPV1 was not expressed in acinar cells (Fig. 2B). Only AQP5 was expressed at the apical membrane of acinar cells. While, TRPV1 was expressed diffusely in cytosol in the ductal cells (green color). In HSG cells, TRPV1 was also diffusely located at the membrane and in the cytoplasm (Fig. 2C). Normal donkey IgG was used as a negative control (data not shown).


TRPV1 in Salivary Gland Epithelial Cells Is Not Involved in Salivary Secretion via Transcellular Pathway.

Choi S, Shin YH, Namkoong E, Hwang SM, Cong X, Yu G, Park K - Korean J. Physiol. Pharmacol. (2014)

Distribution of TRPV1 in salivary gland epithelial cells (SGEC). Representative immunofluorescence labeling of TRPV1 in mSMG (A), hSMG (B), and HSG cells (C). SMGs sections and HSG were immunostained with anti-TRPV1 antibody and AQP5 antibody, then incubated with Alexa Fluor-linked anti-rabbit IgG (red) and Alexa Fluor-linked anti-goat IgG (green). Nuclei (blue) were labeled with 4,6-diamidino-2-phenylindole. (A) TRPV1were mainly detected in apical membrane in acinar cells and in basolateral membrane in ductal cells. AQP5 was used as a marker for acinar cells that was exclusively expressed in the apical membrane of acinar cells (red color). The merged orange color indicates that expression of TRPV1 at the apical membrane in acinar cells. (B) In hSMG, higher expression levels of TRPV1 was observed in ductal cells compared to acinar cells. (C) In HSG cells, TRPV1 was widespread in the cytoplasm. Scale bar indicates 20 µm. The results are representative of four independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4296043&req=5

Figure 2: Distribution of TRPV1 in salivary gland epithelial cells (SGEC). Representative immunofluorescence labeling of TRPV1 in mSMG (A), hSMG (B), and HSG cells (C). SMGs sections and HSG were immunostained with anti-TRPV1 antibody and AQP5 antibody, then incubated with Alexa Fluor-linked anti-rabbit IgG (red) and Alexa Fluor-linked anti-goat IgG (green). Nuclei (blue) were labeled with 4,6-diamidino-2-phenylindole. (A) TRPV1were mainly detected in apical membrane in acinar cells and in basolateral membrane in ductal cells. AQP5 was used as a marker for acinar cells that was exclusively expressed in the apical membrane of acinar cells (red color). The merged orange color indicates that expression of TRPV1 at the apical membrane in acinar cells. (B) In hSMG, higher expression levels of TRPV1 was observed in ductal cells compared to acinar cells. (C) In HSG cells, TRPV1 was widespread in the cytoplasm. Scale bar indicates 20 µm. The results are representative of four independent experiments.
Mentions: We then studied location of TRPV1 using confocal microscopy. Fig. 2A shows TRPV1 proteins in mSMG (green color). TRPV1 was mainly detected at the apical membrane in acinar cells and at the basolateral membrane in ductal cells. We used AQP5 as a marker for acinar cells that was exclusively expressed in the apical membrane of acinar cells (red color). Thus, the merged orange color in Fig. 2A indicates that expression of TRPV1 at the apical membrane in acinar cells. In hSMG, TRPV1 was not expressed in acinar cells (Fig. 2B). Only AQP5 was expressed at the apical membrane of acinar cells. While, TRPV1 was expressed diffusely in cytosol in the ductal cells (green color). In HSG cells, TRPV1 was also diffusely located at the membrane and in the cytoplasm (Fig. 2C). Normal donkey IgG was used as a negative control (data not shown).

Bottom Line: However, capsaicin (CAP), TRPV1 agonist, had little effect on intracellular free calcium concentration ([Ca(2+)]i) in these cells, although carbachol consistently increased [Ca(2+)]i.Saliva flow rate also showed insignificant change in the mice treated with PILO plus CAP compared with that in mice treated with PILO alone.Taken together, our results suggest that although TRPV1 is expressed in SGEC, it appears not to play any direct roles in saliva secretion via transcellular pathway.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute, Seoul 110-749, Korea.

ABSTRACT
Transient receptor potential vanilloid subtype 1 (TRPV1) was originally found in sensory neurons. Recently, it has been reported that TRPV1 is expressed in salivary gland epithelial cells (SGEC). However, the physiological role of TRPV1 in salivary secretion remains to be elucidated. We found that TRPV1 is expressed in mouse and human submandibular glands (SMG) and HSG cells, originated from human submandibular gland ducts at both mRNA and protein levels. However, capsaicin (CAP), TRPV1 agonist, had little effect on intracellular free calcium concentration ([Ca(2+)]i) in these cells, although carbachol consistently increased [Ca(2+)]i. Exposure of cells to high temperature (>43℃) or acidic bath solution (pH5.4) did not increase [Ca(2+)]i, either. We further examined the role of TRPV1 in salivary secretion using TRPV1 knock-out mice. There was no significant difference in the pilocarpine (PILO)-induced salivary flow rate between wild-type and TRPV1 knock-out mice. Saliva flow rate also showed insignificant change in the mice treated with PILO plus CAP compared with that in mice treated with PILO alone. Taken together, our results suggest that although TRPV1 is expressed in SGEC, it appears not to play any direct roles in saliva secretion via transcellular pathway.

No MeSH data available.


Related in: MedlinePlus