PhD Scientific Days 2020

Theoretical and Translational IV. Lectures

Role of Aquaporin 4 in Lacrimal Gland Ductal Fluid Secretion in Mice

Előadó neve

Elekes, Greta, MSc

Előadó munkahelye

University of Szeged, Department of Ophtalamology

Előadó telefonszáma

+36307340813

Előadó e-mail címe

elgreta2@gmail.com

Az előadás címe

Role of Aquaporin 4 in Lacrimal Gland Ductal Fluid Secretion in Mice

Szerző(k) neve és munkahelye

Elekes Gréta1, Szarka Dóra1, Margaréta Korsós2, Orsolya Berczeli1, László Szalay1, Dénes Török3, Edit Tóth-Molnár1

Department of Ophthalmology1, Department of Pharmacology and Pharmacotherapy2, Department of Anatomy3, University of Szeged, Szeged, Hungary

Szekció

Theoretical and Translational IV. Lectures

Language of the presentation

English

Section, first choice

Pathology and Oncology

Section, second choice

Theoretical and Translational Medicine

Összefoglaló szövege

Introduction: Aquaporins (AQPs) are transcellular water channels that can be essential in the physiology of various secretory epithelia. Although earlier reports demonstrated presence of AQP4 in the duct cells from rabbit lacrimal glands (LG) and substantial alterations of AQP4 mRNA levels were also demonstrated in experimental dry eye and during pregnancy.

Aims: The functional relevance of AQP4 in LG duct secretion has to be clarified, therefore in this present study ductal fluid secretion was investigated using AQP4 knock out (KO) mouse strain.

Methods: Immunofluorescence was used to localize AQP4 protein in LGs. Duct segments were isolated from wild type (WT) and KO mice as we previously described. After the ends of the ducts were sealed, ductal fluid secretions evoked by cell-permeable cAMP analogue (8-bromo cAMP, 100 μM); carbachol (100 μM); vasoactive intestinal peptide (VIP, 200 nM); and phenylephrine (PHE, 10 μM) were measured by video-microscopy. Statistical significance was calculated with one-way ANOVA. Data were presented as means ± SEM. A p value of <0.05 was regarded as significant.

Results: Immunofluorescence demonstrated the predominant presence of AQP4 protein in the basolateral membranes from WT mice. The secretory rates (Jv, pl/min/mm2) were calculated for the first 10 minutes of stimulation. Carbachol (WT: 215.7±73.9; KO: 216.2±37.3; p=0,242), and PHE (WT: 248.5±91.3; KO: 195.3±51.01; p=0,183) caused similar secretory responses in ducts from WT and KO animals. In contrast, 8-bromo cAMP (WT: 190.5±22.4; KO: 57.6±23.8; p=0.026), and VIP (WT: 256.3±51.02; KO: 141.07±34.26; p=0.01) stimulation resulted in significantly reduced secretory rates in ducts from KO LGs compared to WT LG ducts.

Conclusions: Our results demonstrate that AQP4 plays functional relevance in the fluid secretion of mouse LG ducts. Role of AQP4 seems to be different in fluid secretions stimulated by various secretagogues and its activity may be related to the intracellular mechanisms induced by the stimulatory agents. These assumptions need further investigations.

NKFIH NN 115611; EFOP-3.6.1-16-2016-00008

Additional Information

Supervisor: Edit Tóth-Molnár
E-mail: tme@tmedit.hu

Bemutatás módja

Szóbeli

Kind

Szabad

Status

elfogadva

Accepted presentation method

szóbeli

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

4781

Start

12:10

End

12:25

Authors (legacy)

Elekes Gréta1, Szarka Dóra1, Margaréta Korsós2, Orsolya Berczeli1, László Szalay1, Dénes Török3, Edit Tóth-Molnár1

Department of Ophthalmology1, Department of Pharmacology and Pharmacotherapy2, Department of Anatomy3, University of Szeged, Szeged, Hungary