The overall long-term goal of this project continues to be directed at understanding the involvement of zinc binding proteins in the absorption, metabolism and biological functions of zinc. Past research from this project has shown through metabolic studies and kinetic analysis that cytokine (interleukin 1) and hormonal regulation of zinc metabolism is mediated through changes in metallothionein gene expression. Metallothionein expression is also directly proportional to dietary zinc intake, probably via a mechanism involving direct interaction between zinc and a nuclear factor. Metallothionein in erythrocytes, having been produced in bone marrow during maturation of these cells, appears to be an index of dietary zinc intake in humans, and thus may act as an indicator of zinc status. The saturable phase of transmucosal zinc movement during absorption has been shown to correlate to binding by a protein we have identified as cysteine-rich intestinal protein (CRIP). Building upon this past information, the next project period has three major Aims.
Aim I is directed a metallothionein. We will further explore erythrocyte metallothionein in male and female human subjects to study turnover of the protein and the response to different levels of supplemental zinc. This will use the ELISA for human metallothionein. Nuclear proteins that bind both zinc and metal regulatory element (MRE) sequences will be further investigated with the goal of purifying a protein(s) that can be shown to interact with dietary zinc to initiate transcription of MRE regulated genes.
Aim II will focus on CRIP gene regulation and studies on the relationship of CRIP to absorption of zinc and, possibly, other nutrient metals. Developmental and hormonal regulation of CRIP mRNA during the postnatal period will receive particular attention, as will regulation during intestinal inflammation and in isolated intestinal cells. Initially, glucocorticoid hormone and thyroxine will receive attention as factors in regulation of neonatal CRIP. Large scale purification and characterization of CRIP will be undertaken. This will allow polyclonal antibody production. It will also allow for in vitro studies to examine the metal binding characteristics of CRIP. The involvement of CRIP in zinc transport will be studied in rat pups during postnatal development and into adulthood, during pregnancy and in monolayer cell cultures of enterocyte-like cells.
Aim III will focus on identification of genes responsive to dietary zinc. We will use differential hybridization of cDNA libraries using first strand-cDNA and subtracted probes. Poly(A)+mRNA from zinc deficient and pair-fed zinc adequate rats will be used to identify those cDNAs that are induced by zinc and these proteins will be identified from known databases where possible. Dietary regulation of genes with MRE promoter sequences will also be examined.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37DK031127-13
Application #
2138576
Study Section
Nutrition Study Section (NTN)
Project Start
1982-07-01
Project End
1997-06-30
Budget Start
1994-07-01
Budget End
1995-06-30
Support Year
13
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Florida
Department
Nutrition
Type
Schools of Earth Sciences/Natur
DUNS #
073130411
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Aydemir, Tolunay Beker; Chang, Shou-Mei; Guthrie, Gregory J et al. (2012) Zinc transporter ZIP14 functions in hepatic zinc, iron and glucose homeostasis during the innate immune response (endotoxemia). PLoS One 7:e48679
Ryu, Moon-Suhn; Guthrie, Gregory J; Maki, Alyssa B et al. (2012) Proteomic analysis shows the upregulation of erythrocyte dematin in zinc-restricted human subjects. Am J Clin Nutr 95:1096-102
Lichten, Louis A; Ryu, Moon-Suhn; Guo, Liang et al. (2011) MTF-1-mediated repression of the zinc transporter Zip10 is alleviated by zinc restriction. PLoS One 6:e21526
Ryu, Moon-Suhn; Langkamp-Henken, Bobbi; Chang, Shou-Mei et al. (2011) Genomic analysis, cytokine expression, and microRNA profiling reveal biomarkers of human dietary zinc depletion and homeostasis. Proc Natl Acad Sci U S A 108:20970-5
Guo, Liang; Lichten, Louis A; Ryu, Moon-Suhn et al. (2010) STAT5-glucocorticoid receptor interaction and MTF-1 regulate the expression of ZnT2 (Slc30a2) in pancreatic acinar cells. Proc Natl Acad Sci U S A 107:2818-23
Cousins, Robert J; Aydemir, Tolunay B; Lichten, Louis A (2010) Plenary Lecture 2: Transcription factors, regulatory elements and nutrient-gene communication. Proc Nutr Soc 69:91-4
Cousins, Robert J (2010) Gastrointestinal factors influencing zinc absorption and homeostasis. Int J Vitam Nutr Res 80:243-8
Liuzzi, Juan P; Guo, Liang; Chang, Shou-Mei et al. (2009) Krüppel-like factor 4 regulates adaptive expression of the zinc transporter Zip4 in mouse small intestine. Am J Physiol Gastrointest Liver Physiol 296:G517-23
Aydemir, Tolunay B; Liuzzi, Juan P; McClellan, Steve et al. (2009) Zinc transporter ZIP8 (SLC39A8) and zinc influence IFN-gamma expression in activated human T cells. J Leukoc Biol 86:337-48
Lichten, Louis A; Liuzzi, Juan P; Cousins, Robert J (2009) Interleukin-1beta contributes via nitric oxide to the upregulation and functional activity of the zinc transporter Zip14 (Slc39a14) in murine hepatocytes. Am J Physiol Gastrointest Liver Physiol 296:G860-7

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