The midcycle increase in ovarian glucose uptake is associated with enhanced expression of glucose transporter 3. Possible role for interleukin-1, a putative intermediary in the ovulatory process.
This study characterizes the rat ovary as a site of hormonally dependent glucose transporter (Glut) expression, and explores the potential role of interleukin (IL)-1, a putative intermediary in the ovulatory process, in this regard. Molecular probing throughout a simulated estrous cycle revealed a significant surge in ovarian Glut3 (but not Glut1) expression at the time of ovulation. Treatment of cultured whole ovarian dispersates from immature rats with IL-1beta resulted in upregulation of the relative abundance of the Glut1 (4.5-fold) and Glut3 (3.5-fold) proteins as determined by Western blot analysis. Other members of the Glut family (i.e., Gluts 2, 4, and 5) remained undetectable. The ability of IL-1 to upregulate Glut1 and Glut3 transcripts proved time-, dose-, nitric oxide-, and protein biosynthesis-dependent but glucose independent. Other ovarian agonists (i.e., TNF alpha, IGF-I, interferon-gamma, and insulin) were without effect. Taken together, our findings establish the mammalian ovary as a site of cyclically determined Glut1 and Glut3 expression, and disclose the ability of IL-1 to induce the ovarian expression as well as translation of Glut1 and Glut3 (but not of Gluts 2, 4, or 5). Our observations also establish IL-1 as the first known regulator of Glut3, the most efficient Glut known to date. In so doing, IL-1, a putative component of the ovulatory process, may be acting to meet the increased metabolic demands imposed on the growing follicle and the ovulated cumulus-enclosed oocyte.
Kol
S
S
Department of Obstetrics and Gynecology, University of Maryland School of Medicine, Baltimore 21201, USA.
Ben-Shlomo
I
I
Ruutiainen
K
K
Ando
M
M
Davies-Hill
T M
TM
Rohan
R M
RM
Simpson
I A
IA
Adashi
E Y
EY
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004971:Estrus / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000235:genetics / Q000494:pharmacology*; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis; D010053:Ovary / Q000378:metabolism* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000494:pharmacology; D012260:Ribonucleases / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D015854:Up-Regulation
D007328:Insulin; D007375:Interleukin-1; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D007334:Insulin-Like Growth Factor I; D007371:Interferon-gamma; D012260:Ribonucleases; D005947:Glucose