Naslov
Immunolocalization of sodium-glucose cotransporter SGLT2 in rat kidneys and other organs

Autori
Sabolić, Ivan ; Balen, Daniela ; Ljubojević, Marija ; Breljak, Davorka ; Brzica, Hrvoje ; Koepsell, Hermann.

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

Izvornik
BioMedical Transporters 2009 ; 6th International Conference, Membrane Transporters and their Impact on Drug Discovery / Hediger, Matthias A - Bern, 2009, 96-96

Skup
BioMedical Transporters 2009 ; 6th International 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
sodium-glucose cotransporter; SGLT2; immunolocalization; kidney; sex differences

Sažetak
Reabsorbtion of glucose in the mammalian kidney is mediated by two Na+-glucose cotransporters, high affinity/low capacity SGLT1 (SLC5A1) and low affinity/high capacity SGLT2 (SLC5A2). A detailed immunolocalization of SGLT1 in rat kidneys and other organs has recently been described using a highly specific polyclonal antibody (Am J Physiol Renal Physiol, 295:475-489, 2008). However, the anti-SGLT2 antibodies often crossreacted with other SGLTs, and a clear-cut localization of SGLT2 along the nephron and in other mammalian organs is still missing. We have generated a novel, anti-rat SGLT2 specific polyclonal antibody (rSGLT2-Ab), and performed immunochemical and RT-PCR studies in kidneys and other organs of male (M) and female (F) rats. In immunoblots of isolated renal membranes from adult rats, the antibody labeled a single protein band of ~75 kDa, whose density exhibited: a) zonal (cortex (CO)>outer stripe (OS)) and sex (F>M) differences, b) increase by castration, and c) decrease by testosterone- and increase by estradiol-treatment in castrates. In tissue cryosections, the rSGLT2-Ab stained brush.border (BB) of S1/S2 proximal tubule (PT) segments (S1>S2 ; S3 was negative), with the F-dominant intensity that matched the immunoblotting pattern. By RT-PCR, the expression of rSGLT2 mRNA showed zonal (C>OS), but no sex differences. In kidneys of prepubertal rats, the respective protein band and immunostaining were weak, and sex-independent. The related, but sex-independent immunoreactivity was detected in smooth muscles (arteries in various organs, lung, uterus), intracellular organelles (cilliary body epithelium, insulin-positive  -cells in pancreas), apical cell membrane (retinal pigment epithelium, bronchal epithelium, fat cells), and individual cells in various organs (lung, spleen, small intestine). We conclude that in rats, SGLT2 resides in: a) BB of the renal cortical PT with the F-dominant expression that occurs after puberty due to posttranscriptional regulation by both androgens (inhibition) and estrogens (stimulation), and b) other organs/tissues/cells with heterogeneous, sex-independent expression.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

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