Diet alters fatty acid composition in C'elegans

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Diet alters fatty acid composition in C.elegans

• Kaja Reisner

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CATEGORIES OF LIPIDS

• Fatty acyls
• Glycerolipids
• Glycerophospholipids
• Sphingolipids
• Sterol lipids
• Prenol lipids
• Saccharolipids
• Polyketides

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FUNCTIONS OF LIPIDS

• Membranes
• - phospholipids, sphingomyelin, sterols

Color scheme PO4 green N(CH3)3 violet
water blue terminal CH3 yellow O red
glycol C brown C chain grey
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FUNCTIONS OF LIPIDS

• 2. Energy storage and metabolism
• glycerolipids (mainly triacylglycerols)

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FUNCTIONS OF LIPIDS

• 3. Signaling
• - sphingolipids, prostaglandins, steroid
  hormones, oxysterols, DAG, PIPs

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FATTY ACIDS
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POLYUNSATURATED FATTTY ACIDS

• essential fatty acids (EFA)
• linoleic acid C182n-6 (omega 6)
• a-linolenic acid C183n-3 (omega 3)

optimal ratio is 21 to 31, due to competition
with delta-6- desaturase
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PUFA metabolism
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cis AND trans
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Trans fatty acids (TFA)
Dyerberg et al., 2006
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Trans fatty acids scary facts
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Nematode C. elegans
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• Chromosomes 5 1 22 2
• Genome Size 97 million 3000 million
• Encoded Proteins 19,099 30,000
• Life Span 0.06 years 80 years
• Sexes male, herm. male, female
• Neurons 381, 302 100,000,000,000
• Synaptic connections 5,000
  100,000,000,000,000
• Somatic cells 1031, 959 ???
• Body size 1 mm 170 cm
• Body weight 5 ?g 75 kg
• Food E.coli Omnivore

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(No Transcript)
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fat-3

• dumpy body shape (cuticle defects)
• slowed development
• abnormalities in egg-laying
• neuronal impairment
• behavioral defects
• etc.

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FAT DIET OLEIC AND ELAIDIC ACID

• Strains N2 and fat-3 (?-6 desaturase)
• Assay
• brood size
• fatty acid analysis (GC-MS)
• Plates
• control (NGM)
• cis-oleic acid (triglyceride)
• elaidic (trans-oleic) acid (triglyceride)

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FAT DIET DOES NOT SIGNIFICANTLY AFFECT BROOD SIZE
IN N2 WORMS
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FAT DIET REDUCES BROOD SIZE IN fat-3 WORMS
p 2.82E-07
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Fat diet has no effect on life span of N2 worms
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trans-fat kills fat-3 worms
whereas cis-fat has no effect
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TRANS-FATS AND HUMAN PUFA DEFICIENCY fat-3
WORMS AS A MODEL?

• PUFA biosynthesis is deficient or inhibited in
  diabetes, obesity, older people, and in the
  presence of insulin, coffee, alcohol, or trans
  fatty acids
• There are alltogether 45 SNPs in human
  delta-6-desaturases (FADS1, FADS2 and FADS3)

- are individuals with reduced fatty acid
desaturase expression more vulnerable to
trans-fat diet?
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THANK YOU !
UNIVERSITY OF KUOPIO A.I. Virtanen
Institute Dept. of Neurobiology Research group
Functional Genomics and Bioinformatics Garry
Wong James Callaway Tanel Jantson Marko
Lehtonen (Dept. of Pharmaceutical Chemistry)
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Ye have made your way from the worm to man, and
much within you is still worm. (Friedrich
Nietzsche)