Relationship Between Orthogonal Arrays of Particles in the Rat Ciliary Epithelium and Maturation of the Blood-Aqueous Barrier

1998 ◽  
Vol 66 (5) ◽  
pp. 675-680 ◽  
Author(s):  
MICHEL HIRSCH ◽  
WALTER NOSKE ◽  
SORAYA MOULESSEHOUL ◽  
YVES POULIQUEN
2001 ◽  
Vol 154 (6) ◽  
pp. 1235-1244 ◽  
Author(s):  
Monica Carmosino ◽  
Giuseppe Procino ◽  
Grazia Paola Nicchia ◽  
Roberta Mannucci ◽  
Jean-Marc Verbavatz ◽  
...  

To test the involvement of the water channel aquaporin (AQP)-4 in gastric acid physiology, the human gastric cell line (HGT)-1 was stably transfected with rat AQP4. AQP4 was immunolocalized to the basolateral membrane of transfected HGT-1 cells, like in native parietal cells. Expression of AQP4 in transfected cells increased the osmotic water permeability coefficient (Pf) from 2.02 ± 0.3 × 10−4 to 16.37 ± 0.5 × 10−4 cm/s at 20°C. Freeze-fracture EM showed distinct orthogonal arrays of particles (OAPs), the morphological signature of AQP4, on the plasma membrane of AQP4-expressing cells. Quantitative morphometry showed that the density of OAPs was 2.5 ± 0.3% under basal condition and decreased by 50% to 1.2 ± 0.3% after 20 min of histamine stimulation, mainly due to a significant decrease of the OAPs number. Concomitantly, Pf decreased by ∼35% in 20-min histamine-stimulated cells. Both Pf and OAPs density were not modified after 10 min of histamine exposure, time at which the maximal hormonal response is observed. Cell surface biotinylation experiments confirmed that AQP4 is internalized after 20 min of histamine exposure, which may account for the downregulation of water transport. This is the first evidence for short term rearrangement of OAPs in an established AQP4-expressing cell line.


1997 ◽  
Vol 110 (22) ◽  
pp. 2855-2860 ◽  
Author(s):  
J.M. Verbavatz ◽  
T. Ma ◽  
R. Gobin ◽  
A.S. Verkman

Freeze-fracture electron microscopy (FFEM) of kidney collecting duct, muscle, astrocytes in brain, and other mammalian tissues has revealed regular square arrays of intramembrane particles called orthogonal arrays of particles (OAPs). Their possible role in membrane structure and transport have been proposed, and their absence or decrease has been noted in a variety of hereditary and acquired diseases. A transgenic mouse lacking water channel AQP4 was used to show that AQP4 is the OAP protein. FFEM was done on kidney, skeletal muscle, and brain from AQP4 wild-type [+/+], heterozygous [+/−] and knock-out [-/-] mice. The [-/-] mice did not express detectable AQP4 protein, but were grossly indistinguishable from [+/+] mice. FFEM was done on blinded samples of kidney, brain and muscle from 9 mice. In all 6 kidney samples from [+/+] and [+/−] mice, OAPs similar to those in AQP4-transfected CHO cells were found in basolateral membranes of collecting duct principal cells. In all muscle and brain samples from [+/+] and [+/−] mice, OAPs of identical ultrastructure to those in kidney were seen, but in smaller patch sizes. OAPs were not seen in any sample from [-/-] mice. Label-fracture analysis using a peptide-derived AQP4 polyclonal antibody showed immunogold labeling of OAPs in AQP4-expressing CHO cells. These studies provide direct evidence that AQP4 is required for formation of OAPs and is a component of OAPs, thus establishing the identity and function of OAPs.


Author(s):  
Hartwig Wolburg ◽  
Karen Wolburg-Buchholz ◽  
Petra Fallier-Becker ◽  
Susan Noell ◽  
Andreas F. Mack

2013 ◽  
Vol 2 (4) ◽  
pp. 143-154 ◽  
Author(s):  
Grazia Paola Nicchia ◽  
Francesco Pisani ◽  
Angelo Sparaneo ◽  
Maria Grazia Mola ◽  
Davide Basco ◽  
...  

2016 ◽  
Vol 17 (8) ◽  
pp. 1230 ◽  
Author(s):  
Petra Fallier-Becker ◽  
Maike Nieser ◽  
Ulrike Wenzel ◽  
Rainer Ritz ◽  
Susan Noell

2009 ◽  
Vol 337 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Susan Noell ◽  
Petra Fallier-Becker ◽  
Urban Deutsch ◽  
Andreas F. Mack ◽  
Hartwig Wolburg

Author(s):  
Grazia P. Nicchia ◽  
Laura Simone ◽  
Maria G. Mola ◽  
Francesco Pisani ◽  
Concetta D. Gargano ◽  
...  

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