Table 2.

AQP KO studies in animals highlighting their role in pulmonary water transport.

S.No	AQP isoform	Experimental model	Study outcomes	Related implications	References
1	AQP1	Mice lung microvascular endothelial cells	A 10-fold decrease in airspace- capillary osmotic water permeability (Pf) compared to wild-type (WT) and decreased lung fluid accumulation.	AQP1 is involved in transcellular water transport and facilitates hydrostatically driven lung edema.	[20]
2	AQP1/AQP4 Double KO	Mice lung microvascular endothelial cells	AQP4KO mice showed no significant effect whereas deletion of AQP4 in AQP1 KO mice showed a 15.3-fold decrease in Pf compared to WT.	AQP4 along with AQP1 contributed to airspace capillary permeability.	[21]
3	AQP1/AQP5 Double KO	Mice type I alveolar epithelial cells	AQP5KO mice showed a 10-fold decrease in Pf of airspace- capillary barrier and further 2 to 3-fold reduction in AQP1/AQP5 double KO mice compared to WT.	AQP5 is essential for majority of water transport across the apical surface of alveolar epithelium.	[22]