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ARS Home » Southeast Area » Little Rock, Arkansas » Arkansas Children's Nutrition Center » Research » Publications at this Location » Publication #218303
Title: Dietary proteins alter tissue-specific gene expression and adiposity in male Sprague-Dawley rats

Author
item SIMMEN, FRANK - ACNC/UAMS
item GREENWAY, AMY - ACNC
item BOWMAN, MARGARET - ACNC
item SU, YING - ACNC/UAMS
item KANG, PING - ACNC

Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 1/31/2008
Publication Date: 4/9/2008
Citation: Simmen, F.A., Greenway, A., Bowman, M., Su, Y., Kang, P. 2008. Dietary proteins alter tissue-specific gene expression and adiposity in male Sprague-Dawley rats [abstract]. The FASEB Journal. 22:700.2.

Interpretive Summary: We examined how the consumption of soy protein isolate by rats causes them to become less obese. We identified several genes whose activity was increased or decreased in small intestine, liver, and abdominal fat in rats consuming soy protein. These genes participate in metabolic functions and/or are related to the thyroid hormone system. Results help understand how soy proteins affect metabolism and add to the foundation for possible designer diet formulations with anti-obesity actions.

Technical Abstract: Dietary soy protein elicits anti-obesity effects in rodents. This study examined adiposity and gene expression in male Sprague-Dawley rats lifetime-fed diets containing casein (CAS), soy protein isolate (SPI), or casein supplemented with genistein (250 mg/kg diet; GEN). At 48 days of age, retroperitoneal fat weight (normalized to body weight) was reduced in SPI vs. CAS and GEN groups. Expression profiling identified 28 SPI up-regulated and 52 SPI down-regulated jejunum transcripts (relative to CAS). A subset of these genes was examined for dietary protein regulation in jejunum, liver, and abdominal fat pad. In jejunum, Stearoyl-CoA desaturase 2 (Scd2) and Krüppel-like factor 15 (Klf15) mRNAs were SPI-induced and Malic enzyme 1 (Me1) and Iodothyronine deiodinase type I (Dio1) mRNAs were SPI-suppressed (compared to CAS), with no effects of GEN observed. In liver, Scd2, thyroid receptors (TR) Alpha 1 and Beta 1, and Dio1 were SPI-induced and Me1 was SPI-suppressed, with no effects of GEN observed. In adipose tissue, Klf15 and Klf9 mRNAs were suppressed by GEN but not SPI. Results identify metabolic (Me1, Scd2), transcriptional (Klf15, Klf9, TRs), and thyroid hormone system (TRs, Dio1) genes affected in complex tissue-specific fashion by SPI that may contribute to anti-obesity in rats. These newly described effects of SPI appear to be unrelated to the major soy isoflavone GEN.