Naslov
Sex-dependent expression of basolateral organic anion transporters NaDC3, Oat1, and Oat3 along the mouse nephron.

Autori
Breljak, Davorka ; Ljubojević, Marija ; Micek, Vedran ; Balen, Daniela ; Brzica, Hrvoje ; Hagos, Yohanes ; Burckhardt, Birgitta C ; Burckhardt, Gerhard ; Antolović, Roberto ; Anzai, Naohiko ; Sabolić, Ivan

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
BioMedical Transporters 2009, 6th International Research Conference, Membrane Transporters and their Impact on Drug Discovery / Hediger, Matthias A - Bern, 2009, 63-64

Skup
BioMedical Transporters 2009, 6th International Research Conference: Membrane Transporters and their Impact on Drug Discovery.

Mjesto i datum
Thun, Švicarska, 09.08.2009. - 13.08.2009

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
sex differences; organic anion; membrane transporter; kidney

Sažetak
In the mammalian kidney, the first step in the elimination of endogenous and exogenous organic anions (OA) is the uptake of these anions across transporters that reside in the basolateral membrane (BLM) of epithelial cells in various nephron segments. In rodents, the active contributors to these processes are: a) primary-active Na/K-ATPase (EC 3.6.3.9), b) secondary-active sodium-dicarboxylate cotransporter 3 NaDC3 (Slc13a3), and c) tertiary-active OA exchangers Oat1 (Slc22a6) and Oat3 (Slc22a8). In order to investigate possible sex-related differences in cellular localization and protein expression of these transporters along the nephron, we have used specific polyclonal antibodies and studied the abundance of the above mentioned proteins by Western blotting (WB) in total cell membranes (TCM), isolated from the whole kidney homogenates, and by immunofluorescence cytochemistry (IC) in kidney cryosections from adult male (M) and female (F) mice. IC studies confirmed localization of these transporters in the BLM of various nephron segments: a) Na/K-ATPase (&#61537; -subunit) was stained with variable intensity in all nephron segments, b) NaDC3 was localized in the proximal tubule (PT ; S1<S2>S3 in the medullary rays>S3 in the outer stripe) and collecting duct (OMCD<IMCD ; CCD was negative), c) Oat1 was detected only in the cortical PT (S1<S2~S3 in the medullary rays ; S3 in the outer stripe was negative), and d) Oat3 was detected in various nephron segments, including S1, S2 and S3 segments of PT, CD, TALH and distal tubules. In WB of TCM, the protein bands of ~110, ~43, ~75 and ~60 kDa for Na/K-ATPase, NaDC3, Oat1 and Oat3, respectively, were labeled. A comparison of IC and WB data in M and F mice revealed similar localization and staining intensity of Na/K-ATPase along the nephron, and similar abundance of the relevant 110 kDa protein in isolated TCM. In contrary, sex-dependent expression was observed for NaDC3, Oat1 and Oat3. The intensity of NaDC3 staining in the cortical PT (S2) was stronger in F than in M, whereas in the inner medulla, the staining intensity in IMCD was higher in M than in F. In TCM, the overall abundance of NaDC3 protein in M was higher than in F. The intensity of Oat1 staining in the cortex (PT S2) was stronger in M than in F, and this finding was confirmed by similar pattern in the abundance of protein in isolated TCM (M>F). Finally, the staining intensity of Oat3 in various cortical tubules, as well as the abundance of its protein in isolated TCM, exhibited M-dominant sex differences. In conclusion, our results indicate that in the mouse kidney: a) the basolateral transporters of OA exhibit heterogeneous localization in epithelial cells along the nephron with largely M-dominant expression, and b) the expression of NaDC3 and Oats correlate well in the cortical PT, but not in the more distal nephron segments.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA