L4_Biol_Growth_and_Nutriiton_08

L4_Biol_Growth_and_Nutriiton_08 - Biology of Growth and...

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Unformatted text preview: Biology of Growth and Nutrition Biology of Growth and Nutrition Growth rates Mechanisms of growth Role of Nutrients in Growth Height Velocity of Western European Ethnicity in Healthy Boys (A) and Girls (B) Puberty Sex hormones Childhood Infant Igf 1,2 & Ins Adapted with Karlberg's ICP growth model Copyright 2005 The Endocrine Society GHIgf 1 & TH Veldhuis, J. D. et al. Endocr Rev 2005;26:114-146 Key Concepts of Growth Not all organs grow at same rate Growth is regulated by Genetics Hormones Environmental factors Nutrition Infection Exercise Hyperplasia Increased cell number Cell Growth Hypertrophy Increased cell size Hyperplasia and Hypertrophy Increased cell number & size Mechanisms of Growth Hyperplasia or Proliferation Cell cycle DNA synthesis cell_cycle_su.exe Cdk cyclins Cdk cyclins Cdk, cyclins p53 Cdk cyclins Cdk cyclins p21, p27, p53 Cdk, cyclins Nutrient Regulation of Cell Cycle Vitamin A, Nuclear receptors & Transcription 9cRA RXR RAR atRA RXR RXR RXRE +/ +/ RAR RXR RARE +/- protein +/- mRNA Nutrient Regulation of Cell Cycle RA through RAR & RXR decreases cell proliferation in some cells/tissues RA through RAR & RXR maintains or increases cell proliferation in other tissues can increase p53 may decrease selective cyclins increases p21 & p27 increases selective cyclins Nutrient Regulation of Cell Cycle Vitamin D, Nuclear receptors & Transcription VDR RXR VDRE VDR 1,25(OH)2D +/ +/- protein +/- mRNA Nutrient Regulation of Cell Cycle Vitamin D active form is 1,25 (OH)2 D binds to its nuclear receptor VDR to regulate selective gene expression increases p21 (and other inhibitors of cell cycle) decreases cell proliferation Nutrients and Proliferation Regulation of cell cycle & proliferation Vitamin A (RA) Vitamin D Zinc Iron DNA synthesis Zn required for DNA synthesis cofactor for terminal dNTP transferase Nutrients and Proliferation Regulation of cell cycle & proliferation Vitamin A (RA) Vitamin D Zinc Iron DNA synthesis Zn Folate Vitamin B12 Folate, B-12 & DNA Synthesis DNA Purines A, G 10-formylTHF methenylTHF Thymidylate dUMP methyleneTHF Methionine SAM SAH Methylation Reactions B12 5-methylTHF Homocysteine THF + Formate Nutrients and Proliferation Regulation of cell cycle & proliferation Vitamin A (RA) Vitamin D Zinc DNA synthesis Zn Folate Vitamin B12 Energy, Bvitamins, Fe, Cu, Mg Mechanisms of Growth Hyperplasia Cell cycle or Proliferation DNA synthesis Cell size mTOR (Target of Rapamycin) regulation protein synthesis Nutrients and Cell Size mTOR regulates protein & cellular synthesis Glucose Amino Acids Amino Acids, Glucose & mTOR Regulation of Cell Size http://web.wi.mit.edu/sabatini/pub/research_MTORsignal.html Nutrients and Cell Size mTOR Regulation of protein & cellular synthesis Glucose Amino Acids and Protein Protein & cellular synthesis Amino acids Energy, B-vitamins (including B-6), Fe, Cu, Mg Vitamin A Mechanisms of Growth Hyperplasia Cell cycle or Proliferation DNA synthesis Cell size mTOR regulation protein synthesis Skeletal growth Nutrients & Skeletal Growth Calcium Vitamin D Vitamin K Mechanisms of Growth Hyperplasia or Proliferation Cell cycle DNA synthesis mTOR (mammalian Target of Rapamycin) Cell size Skeletal growth Igf system TH regulation protein synthesis Hormonal regulation of growth Nutrients &Hormones Regulating Growth Igf 1 Regulated by nutrients Zn Thyroid Hormone (TH) Iodine Nutrition key to growth - provides energy & `building blocks' - necessary for DNA & protein synthesis - regulates mTOR, Igf1, cell proliferation Growth decreases or stops with - protein-energy malnutrition -- Select single nutrient deficiencies - Vitamin A, D & K , Zn, Fe, I ...
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This note was uploaded on 02/23/2008 for the course NS 1220 taught by Professor Brannon,p. during the Spring '07 term at Cornell.

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