title: Effects of Obesity and Metabolic Syndrome on Steroidogenesis and Folliculogenesis in the Female Ossabaw Mini-Pig.
abstract: The discrete effects of obesity on infertility in females remain undefined to date. To investigate obesity-induced ovarian dysfunction, we characterized metabolic parameters, steroidogenesis, and folliculogenesis in obese and lean female Ossabaw mini-pigs. Nineteen nulliparous, sexually mature female Ossabaw pigs were fed a high fat/cholesterol/fructose diet (n=10) or a control diet (n=9) for eight months. After a three-month diet-induction period, pigs remained on their respective diets and had ovarian ultrasound and blood collection conducted during a five-month study period after which ovaries were collected for histology, cell culture, and gene transcript level analysis. Blood was assayed for steroid and protein hormones. Obese pigs developed abdominal obesity and metabolic syndrome, including hyperglycemia, hypertension, insulin resistance and dyslipidemia. Obese pigs had elongated estrous cycles and hyperandrogenemia with decreased LH, increased FSH and luteal phase progesterone, and increased numbers of medium, ovulatory, and cystic follicles. Theca cells of obese, compared to control, pigs displayed androstenedione hypersecretion in response to in vitro treatment with LH, and up-regulated 3-beta-hydroxysteroid dehydrogenase 1 and 17-beta-hydroxysteroid dehydrogenase 4 transcript levels in response to in vitro treatment with LH or LH + insulin. Granulosa cells of obese pigs had increased 3-beta-hydroxysteroid dehydrogenase 1 transcript levels. In summary, obese Ossabaw pigs have increased transcript levels and function of ovarian enzymes in the delta 4 steroidogenic pathway. Alterations in LH, FSH, and progesterone, coupled with theca cell dysfunction, contribute to the hyperandrogenemia and disrupted folliculogenesis patterns observed in obese pigs. The obese Ossabaw mini-pig is a useful animal model in which to study the effects of obesity and metabolic syndrome on ovarian function and steroidogenesis. Ultimately, this animal model may be useful toward the development of therapies to improve fertility in obese and/or hyperandrogenemic females or in which to examine the effects of obesity on the maternal-fetal environment and offspring health.
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America.
authors.forename: Annie E
authors.initials: AE
authors.lastname: Newell-Fugate
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America.
authors.forename: Jessica N
authors.initials: JN
authors.lastname: Taibl
authors.affiliation: Department of Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5120, United States of America.
authors.forename: Mouhamad
authors.initials: M
authors.lastname: Alloosh
authors.affiliation: Department of Cellular & Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202-5120, United States of America.
authors.forename: Michael
authors.initials: M
authors.lastname: Sturek
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America.
authors.forename: Janice M
authors.initials: JM
authors.lastname: Bahr
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America.
authors.forename: Romana A
authors.initials: RA
authors.lastname: Nowak
authors.affiliation: Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States of America.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Krisher
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000735:Androstenedione / Q000097:blood*; D000818:Animals; D059305:Diet, High-Fat / Q000009:adverse effects; D030762:Estrous Cycle; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood* / Q000494:pharmacology; D015870:Gene Expression; D006107:Granulosa Cells / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007247:Infertility, Female / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D007328:Insulin / Q000494:pharmacology; D007986:Luteinizing Hormone / Q000097:blood* / Q000494:pharmacology; D024821:Metabolic Syndrome / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D009765:Obesity / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D064029:Peroxisomal Multifunctional Protein-2 / Q000235:genetics / Q000378:metabolism; D061251:Primary Cell Culture; D011374:Progesterone / Q000097:blood*; D012333:RNA, Messenger / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D013552:Swine; D013556:Swine, Miniature; D013799:Theca Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
chemical_list: D007328:Insulin; D012333:RNA, Messenger; D000735:Androstenedione; D011374:Progesterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D015096:3-Hydroxysteroid Dehydrogenases; D064029:Peroxisomal Multifunctional Protein-2