Effect of Aging andor Caloric Restriction on Calpain Expression in Skeletal Muscle: Implications for

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Effect of Aging and/or Caloric Restriction on
Calpain Expression in Skeletal Muscle
Implications for Sarcopenia
By Joel Rollefstad Mentor Dr. Hepple
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Muscle and Aging

• Imbalance b/n synthesis and degradation
• ? anabolic hormones (T, GH, IGF-1)
• ? inflammatory agents (catabolic)
  interleukin-6, TNF-a
• ? Oxidative stress (aerobic by-product)
• ? Physical Activity
• Result muscle atrophy

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?
Calpastatin
(-)
? anabolic agents
Calpain 3
? catabolic agents

(-)


Protein Degradation
Protein Synthesis
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Protein Degradation Pathways

• Ca2 -dependent Calpain system
• Ubiquitin-Proteasome Pathway (ATP dependent)
• Lysosomal Protease Pathway (ex. Cathepsins)

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Jackman Kandarian, 2004.
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Aging muscle and CR

• Prevents fiber loss, and slows fiber atrophy
• -Boreham, 1988
• CR decreases the proportion of severely atrophied
  fibers in some muscles of 36 month old animals.
• -McKiernan et al., 2004

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Study Design

• 8 35 mo old Fischer 344 x Brown Norway rats (CR
  and AL for each group)
• AL free access to food
• CR 60 of AL (enriched)
• An original study by Hagen et al. (2004), showed
  the gastrocnemius muscle has the most atrophy of
  the hindlimb muscles

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Methods

• Gastroc. muscle taken and frozen immediately in
  liquid nitrogen
• RNeasy kit used according to protocol to isolate
  mRNA
• Reverse Transcription produced cDNA from mRNA
  and amplified amount of cDNA
• Primers for Cal3, Cast, 18s genes used for Real
  Time PCR reaction
• SYBER green

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18s
Calpain 3
Calpain 10
Calpastatin
Marker
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Results
Table 1 Change in Gastrocnemius Muscle Mass
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Results
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Results
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Conclusion

• CR ?s the rate at which muscle protein is
  degraded by attenuating rise in Cal Cast
• High level of spontaneous activity in CR rats
• - McCarter et al., 2004
• Inactivity increases Calpain activation
  - Haddad et al., 2003
• Gastroc. muscle primarily locomotor

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Future Studies

• Soleus muscle maintains higher activation level
  across age groups (results will reflect effects
  of age as opposed to effects of activation level)

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References

• Boreham, C.A., Watt, P.W., Williams, P.E., Merry,
  B.J., Goldspink, G. Goldspink, D.F. (1988).
  Effects of aging chronic dietary restriction
  on the morphology of fast and slow muscles of
  the rat. Journal of Anatomy, 157 111-125.
• Haddad, F., Roy, R. R., Zhong, H., Edgerton, V.
  R., and Baldwin, K. M. (2003). Atrophy responses
  to muscle inactivity. II. Molecular markers of
  protein deficits. Journal of Applied Physiology,
  95 791-802.
• Hagen, J.L., Krause, D.J., Baker, D.J., Fu, M,
  H., Tarnopolsky, M.A. Hepple, R.T. (2004).
  Skeletal muscle aging in F344BN F1-Hybrid rats
  Mitochondrial dysfunction contributes to the
  age-associated reduction in VO2max. Journal of
  Gerontology, 59A(11)000-000.
• Jackman, R.W., Kandarian, S.C. (2004). The
  molecular basis of skeletal muscle atrophy. Am J
  Physiol Cell Physiol, 287 C834- C843.
• McCarter, R., Shimokawa, I., Ikeno, Y., Higami,
  Y., Hubbard, G., Yu, B., McMahan, C. (1997).
  Physical activity as a factor in the action of
  dietary restriction on aging Effects in Fischer
  344 rats. Aging Clin. Exp. Res. 9 73-79.
• McKiernan, S., Bua, E., McGorray, J., Aiken, J.
  (2004). Early-onset calorie restriction
  conserves fiber number in aging rat skeletal
  muscle. The FASEB Journal, 18(3) 580-1.

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Special Thanks To

• Dr. Russ Hepple
• Dr. David Baker
• Dr. Aaron Tubman
• Markin-Flanagan
• The Undergraduate Student Research Program