Resveratrol and Decreased Fat Deposition in C. elegans
Alexandra ******- Period 3
Manhasset Science Research
1998
Obesity Trends* Among U.S. Adults1990, 1998, 2007
(*BMI 30, or about 30 lbs. overweight for 5’4” person)
2007
1990
No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%
Source: Center for Disease Control & Prevention [http://www.cdc.gov/nccdphp/dnpa/obesity/trend/maps/obesity_trends_2007.ppt#487,5,Slide 5]
Need
Knowledge Base
Figure 1: Chemical structure of Nile Red (A) & Sudan Black (B) staining. Nile Red staining in wild-type and mutant C. elegans (C-E). Sudan Black staining in wild-type (F) & mutant (G) organisms.Source: (Ashrafi, 2007) [http://www.wormbook.org/chapters/www_obesity/obesity.html]
Resveratrol
Figure 2: chemical structure of resveratrol (C14H12O3)
[http://www.3dchem.com/molecules.asp?ID=277]
• Chemical found in grapes; red wine
• Popular dietary supplement- advertised as anti-aging substance
•May explain “French paradox”
Literature ReviewRNAi in E. coli food
ingested by C. elegans
Mutant C. elegans strains
Nile Red Staining ingested
Wild-type C. elegans
Fat deposition monitored as RNAi silences genes
Results
305 gene silences cause reduced fat storage
112 gene silences cause increased fat storage
Figure 2: RNAi was used to silence certain genes to determine which ones regulated fat in C. elegans (Ashrafi, et al, 2003) [chart made by author using materials from article]
Literature Review
• C. elegans in dauer need AMP-activated protein kinase (AMPK) to survive– Dauer- larval “hibernation”
stage in which metabolic rate is slowed; fat deposits increase to sustain organism
– AMPK- fat regulatory enzyme
• aak2 mutant dauers lack AMPK destroy fat
• (Roy, et al, 2009)
C. Elegans dauerorganisms
Wild-type N2 strain-Has AMPK
aak-2 mutant strainNo AMPK
Sudan Blackstaining
Sudan Blackstaining
Fat reservesRationed at
Constant level
Fat reservesdestroyed
Organisms died
Figure 3: The enzyme AMPK is necessary for C. elegans in dauer to survive and regulate fat deposition (Roy, et al, 2009) [chart created by author]
Literature Review• Resveratrol
improves health and survival of mice on a high-calorie diet
• (Baur, et al, 2006)
Positive effects ofResveratrol
in mice
Increased survival
Activation of AMPK Increased insulin
Sensitivityless fatty acid
syntase
More mitochondriaLess damage to
Liver and pancreas
Figure 4: Resveratrol caused many positive changes in the overall health of mice similar to the effects of caloric restriction
(Baur, et al, 2006) [chart made by author adapted from article]
Literature Review
Human preadipocytes
prevented from becomingfat cells
Decreasedfat storage
Stimulates adiponectin
Anti-obesity properties
of resveratrol
Figure 5: In human preadipocytes (fat cell precursors), resveratrol in extremely high doses (3-5 g) caused positive changes in the cells. (Fischer-Posovsky, et al, 2008) [chart made by author]
Purpose/Hypothesis
• Purpose: to observe the effects of resveratrol on fat deposition in C. elegans and comparing it to caloric restriction
• Null hypothesis: Resveratrol will cause no change in fat deposition in C. elegans
• Alternate hypothesis: Resveratrol will cause a decrease in fat deposition and mimic the effects of caloric restriction
Methodology
C. ElegansN= 75
25= control- no resveratrol
or caloric restriction
25= experimental- caloric restriction
25= experimental- Resveratrol
(5.0 mg/kg per day)
Sudan Black StainingInserted into E. coli food-
Ingested by organism
Fluorescent microscopeexamination
Statistical analysis-Using SPSS program
Budget
Vendor Order # Quantity Description Unit Price Total Price
Caenorhabditis Genetic Center TJ3014 10 Wild-type C. elegans N2 $7.00 $70.00
GNC 429702 1 Resveratrol- 500 mg $74.99 $74.99
Carolina Biological 2009 NP-17-3500 2 Sudan III Stain $26.85 $53.70
Total Price: $198.69
Do-ability
• Resveratrol studies have been done in previous years
• C. elegans is a useful model organism that is easily obtained
• Sudan Black staining and fluorescent microscope examination are possible