Related Experiment Video
Updated: Sep 11, 2025
10:05
In Vitro Analysis of PDZ-dependent CFTR Macromolecular Signaling Complexes
Published on: August 13, 2012
11.4K
Ionocyte CFTR Coordinates Chloride Absorption and Secretion to Balance Airway Fluid
Feng Yuan1,2,3, Javahir Hajibabazade1, Yaling Yi1,2,3
1Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa.
American Journal of Respiratory and Critical Care Medicine
|August 15, 2025
Summary
Cystic fibrosis transmembrane conductance regulator (CFTR) in lung ionocytes controls both chloride absorption and secretion, crucial for airway fluid balance. This finding aids in developing targeted therapies for cystic fibrosis.
Area of Science:
- Respiratory Physiology
- Cell Biology
- Genetics
Background:
- The cystic fibrosis transmembrane conductance regulator (CFTR) is vital for airway surface liquid (ASL) homeostasis.
- Dysfunctional CFTR in cystic fibrosis (CF) disrupts fluid balance.
- The precise role of CFTR in pulmonary ionocytes for ion and fluid transport remains debated.
Purpose of the Study:
- To clarify the function of CFTR in pulmonary ionocytes regarding chloride absorption and secretion.
- To investigate CFTR's role using conditional ionocyte-specific genetic manipulation.
Main Methods:
- Development of a novel transgenic ferret model for ionocyte-specific CFTR inactivation and lineage tracing.
- Utilizing a second transgenic model for CFTR reactivation in CF ionocytes.
- Investigating ion and fluid transport mechanisms and cell regeneration.
Main Results:
- Ionocyte-specific CFTR was found to mediate both chloride absorption and secretion.
- This supports a dual role for ionocytes in maintaining airway fluid homeostasis.
- CFTR deletion in ionocytes triggered rapid renewal of CFTR-competent ionocytes.
Conclusions:
- CFTR expressed in lung ionocytes is essential for both chloride absorption and secretion.
- This dual function is critical for salt and fluid transport in the large airways.
- Understanding these cell-specific functions is key for CF therapeutic development.
More Related Videos
Related Concept Videos
01:29Roles of Electrolytes: Chloride and Bicarbonate
362
Chloride ions contribute to the osmotic pressure gradient distinguishing the intracellular fluid (ICF) from the extracellular fluid (ECF). They counterbalance positively charged ions in the ECF and ensure its electrochemical stability. The renal system's process of chloride absorption and release generally mirrors that of sodium ions.
Conditions such as hypochloremia can arise from insufficient chloride reabsorption by the kidneys, often compounded by extended bouts of diarrhea, vomiting,...
Conditions such as hypochloremia can arise from insufficient chloride reabsorption by the kidneys, often compounded by extended bouts of diarrhea, vomiting,...
362
01:26Reabsorption and Secretion in the DCT and Collecting Duct
1.6K
The early phase of the DCT manages the reabsorption of approximately 10-15% of filtered water, 5–10% of filtered sodium, and 5–10% of filtered chloride. This process is facilitated by Na+–Cl− symporters in apical membranes and sodium-potassium pumps, as well as Cl− leakage channels in basolateral membranes. The early DCT also stands out as a site where parathyroid hormone (PTH) stimulates calcium reabsorption, depending on the body's requirements.
The distal...
The distal...
1.6K
01:23Transcellular Transport of Solutes
3.8K
Transcellular transport of solutes is the movement of substances like monosaccharides and amino acids through polarized cells. This transport mechanism is primarily seen in epithelial and endothelial cells aided by membrane transport proteins such as channels and transporters. The tight junctions between these cells confine the membrane proteins to the two sides of the cell. The epithelial cells have distinct apical and basolateral domains. In contrast, the endothelial cells show the luminal...
3.8K
01:23Cystic Fibrosis: Pathogenesis
361
Cystic fibrosis (CF), an autosomal recessive disorder, significantly affects the function of exocrine glands. This genetically inherited disease is characterized by the production of thick and sticky mucus, which can severely affect various organs and systems in the body.
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation,...
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation,...
361
01:17Reabsorption and Secretion in the Loop of Henle
1.7K
The thick ascending limb of the nephron loop has Na+–K+–2Cl− symporters in the apical membranes of its cells. These symporters simultaneously reclaim one sodium ion, one potassium ion, and two chloride ions from the tubular fluid. Sodium ions are actively transported into the interstitial fluid at the base and sides of the cell, diffusing into the vasa recta. Chloride ions move through leakage channels in the basolateral membrane into the interstitial fluid and then into the...
1.7K
01:24Cystic Fibrosis: Management
224
Cystic fibrosis (CF) is an autosomal recessive disorder that predominantly affects individuals of Northern European descent, occurring at a rate of 1 in 3500. It is caused by a genetic mutation in a gene on chromosome 7, most commonly the ΔF508 mutation, that codes for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. This results in thicker mucus secretions and obstruction pathologies in multiple organs, including the lungs and sinuses.
Sinus disease and chronic...
Sinus disease and chronic...
224