Abstract
Background & Aims: Pancreatic bicarbonate (HCO3 -) secretion is important for a healthy pancreas as well as digestive physiology. However, how human pancreatic duct cells secrete copious amounts of HCO 3 - has long been a puzzle. Here, we report that a dynamic increase in the cystic fibrosis transmembrane conductance regulator (CFTR) HCO3 - permeability by intracellular Cl- concentration ([Cl-]i)-sensitive mechanisms plays a pivotal role in pancreatic HCO3 - secretion. Methods: The role of [Cl-]i-sensitive kinases in CFTR-mediated HCO 3 - transport was examined in heterologous expression systems, PANC1 human pancreatic duct cells, and human and guinea pig pancreatic tissues using an integrated molecular and physiologic approach. Results: In human pancreatic tissues, CFTR-positive duct cells abundantly expressed with-no-lysine (WNK1) kinase, oxidative stress-responsive kinase 1 (OSR1), and sterile 20/SPS1-related proline/alanine-rich kinase (SPAK), which are known to be activated by low [Cl-]i. Interestingly, CFTR activation rapidly decreased [Cl-]i in response to luminal Cl - depletion in polarized PANC1 human pancreatic duct cells. Notably, the WNK1-mediated OSR1 and SPAK activation by low [Cl-]i strongly increased CFTR HCO3 - permeability in CFTR-transfected HEK 293T, PANC1, and guinea pig pancreatic duct cells, making CFTR primarily an HCO3 - channel, which is essential for the secretion of pancreatic juice containing HCO3 - at a concentration greater than 140 mmol/L. In contrast, OSR1 and SPAK activation inhibited CFTR-dependent Cl-/HCO3 - exchange activity that may reabsorb HCO3 - from the high HCO 3 --containing pancreatic juice. Conclusions: These results indicate that the [Cl-]i-sensitive activation of the WNK1-OSR1/SPAK pathway is the molecular switch to generate HCO3 --rich fluid in the human pancreatic duct.
| Original language | English |
|---|---|
| Pages (from-to) | 620-631 |
| Number of pages | 12 |
| Journal | Gastroenterology |
| Volume | 139 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2010 Jan 1 |
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All Science Journal Classification (ASJC) codes
- Hepatology
- Gastroenterology
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Dynamic regulation of CFTR bicarbonate permeability by [Cl -]i and its role in pancreatic bicarbonate secretion. / Park, Hyun Woo; Nam, Joo Hyun; Kim, Joo Young; Namkung, Wan; Yoon, Jae Seok; Lee, Jung Soo; Kim, Kyung Sik; Venglovecz, Viktoria; Gray, Michael A.; Kim, Kyung Hwan; Lee, Min Goo.
In: Gastroenterology, Vol. 139, No. 2, 01.01.2010, p. 620-631.Research output: Contribution to journal › Article
TY - JOUR
T1 - Dynamic regulation of CFTR bicarbonate permeability by [Cl -]i and its role in pancreatic bicarbonate secretion
AU - Park, Hyun Woo
AU - Nam, Joo Hyun
AU - Kim, Joo Young
AU - Namkung, Wan
AU - Yoon, Jae Seok
AU - Lee, Jung Soo
AU - Kim, Kyung Sik
AU - Venglovecz, Viktoria
AU - Gray, Michael A.
AU - Kim, Kyung Hwan
AU - Lee, Min Goo
PY - 2010/1/1
Y1 - 2010/1/1
N2 - Background & Aims: Pancreatic bicarbonate (HCO3 -) secretion is important for a healthy pancreas as well as digestive physiology. However, how human pancreatic duct cells secrete copious amounts of HCO 3 - has long been a puzzle. Here, we report that a dynamic increase in the cystic fibrosis transmembrane conductance regulator (CFTR) HCO3 - permeability by intracellular Cl- concentration ([Cl-]i)-sensitive mechanisms plays a pivotal role in pancreatic HCO3 - secretion. Methods: The role of [Cl-]i-sensitive kinases in CFTR-mediated HCO 3 - transport was examined in heterologous expression systems, PANC1 human pancreatic duct cells, and human and guinea pig pancreatic tissues using an integrated molecular and physiologic approach. Results: In human pancreatic tissues, CFTR-positive duct cells abundantly expressed with-no-lysine (WNK1) kinase, oxidative stress-responsive kinase 1 (OSR1), and sterile 20/SPS1-related proline/alanine-rich kinase (SPAK), which are known to be activated by low [Cl-]i. Interestingly, CFTR activation rapidly decreased [Cl-]i in response to luminal Cl - depletion in polarized PANC1 human pancreatic duct cells. Notably, the WNK1-mediated OSR1 and SPAK activation by low [Cl-]i strongly increased CFTR HCO3 - permeability in CFTR-transfected HEK 293T, PANC1, and guinea pig pancreatic duct cells, making CFTR primarily an HCO3 - channel, which is essential for the secretion of pancreatic juice containing HCO3 - at a concentration greater than 140 mmol/L. In contrast, OSR1 and SPAK activation inhibited CFTR-dependent Cl-/HCO3 - exchange activity that may reabsorb HCO3 - from the high HCO 3 --containing pancreatic juice. Conclusions: These results indicate that the [Cl-]i-sensitive activation of the WNK1-OSR1/SPAK pathway is the molecular switch to generate HCO3 --rich fluid in the human pancreatic duct.
AB - Background & Aims: Pancreatic bicarbonate (HCO3 -) secretion is important for a healthy pancreas as well as digestive physiology. However, how human pancreatic duct cells secrete copious amounts of HCO 3 - has long been a puzzle. Here, we report that a dynamic increase in the cystic fibrosis transmembrane conductance regulator (CFTR) HCO3 - permeability by intracellular Cl- concentration ([Cl-]i)-sensitive mechanisms plays a pivotal role in pancreatic HCO3 - secretion. Methods: The role of [Cl-]i-sensitive kinases in CFTR-mediated HCO 3 - transport was examined in heterologous expression systems, PANC1 human pancreatic duct cells, and human and guinea pig pancreatic tissues using an integrated molecular and physiologic approach. Results: In human pancreatic tissues, CFTR-positive duct cells abundantly expressed with-no-lysine (WNK1) kinase, oxidative stress-responsive kinase 1 (OSR1), and sterile 20/SPS1-related proline/alanine-rich kinase (SPAK), which are known to be activated by low [Cl-]i. Interestingly, CFTR activation rapidly decreased [Cl-]i in response to luminal Cl - depletion in polarized PANC1 human pancreatic duct cells. Notably, the WNK1-mediated OSR1 and SPAK activation by low [Cl-]i strongly increased CFTR HCO3 - permeability in CFTR-transfected HEK 293T, PANC1, and guinea pig pancreatic duct cells, making CFTR primarily an HCO3 - channel, which is essential for the secretion of pancreatic juice containing HCO3 - at a concentration greater than 140 mmol/L. In contrast, OSR1 and SPAK activation inhibited CFTR-dependent Cl-/HCO3 - exchange activity that may reabsorb HCO3 - from the high HCO 3 --containing pancreatic juice. Conclusions: These results indicate that the [Cl-]i-sensitive activation of the WNK1-OSR1/SPAK pathway is the molecular switch to generate HCO3 --rich fluid in the human pancreatic duct.
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U2 - 10.1053/j.gastro.2010.04.004
DO - 10.1053/j.gastro.2010.04.004
M3 - Article
VL - 139
SP - 620
EP - 631
JO - Gastroenterology
JF - Gastroenterology
SN - 0016-5085
IS - 2
ER -