University of Kentucky
P-bodies are Elevated with Age-, but Not Disuse-associated Skeletal Muscle Atrophy
Institution
University of Kentucky
Faculty Advisor/ Mentor
Esther E. Dupont-Versteegden; Jena White; Amy Ferry
Abstract
Processing Bodies (p-bodies) are small cytoplasmic granules which contain many enzymes involved in decapping and degradation of unused mRNA and are proposed to function as storage for unused mRNA until translation. We hypothesized that age- and disuse-induced muscle atrophy would be associated with an increase in p-bodies. Therefore, the purpose of this study was to determine the difference in the abundance of p-bodies between young versus old, and ambulatory versus hindlimb suspended rats. Brown Norway/Fisher344 male rats at 6 and 32 months of age were hindlimb suspended for 14 days to induce muscle atrophy. Gastrocnemius muscles from 6 and 32 month old ambulatory and hindlimb suspended rats were dissected and homogenized for protein abundance determination. Western blotting was performed with Decapping Protein 2 (DCP2) antibody to measure p-bodies abundance in the protein samples. DCP2 is a protein involved in decapping and degradation of mRNA and is a strong marker for pbodies. Bands from Western blots were analyzed based on their optical density value, which is directly proportional to the abundance of DCP2 protein. We found that DCP2 was significantly more abundant in 32 month old compared to 6 month old rats. However, no significant difference was observed in the abundance of DCP2 between ambulatory and hindlimb suspended rats at either age. Therefore, we concluded that p-bodies are elevated with age-associated muscle atrophy, but not with disuse. Future studies will be directed toward determining whether other components of p-bodies are elevated and investigating the functional significance of increased presence of p-bodies.
P-bodies are Elevated with Age-, but Not Disuse-associated Skeletal Muscle Atrophy
Processing Bodies (p-bodies) are small cytoplasmic granules which contain many enzymes involved in decapping and degradation of unused mRNA and are proposed to function as storage for unused mRNA until translation. We hypothesized that age- and disuse-induced muscle atrophy would be associated with an increase in p-bodies. Therefore, the purpose of this study was to determine the difference in the abundance of p-bodies between young versus old, and ambulatory versus hindlimb suspended rats. Brown Norway/Fisher344 male rats at 6 and 32 months of age were hindlimb suspended for 14 days to induce muscle atrophy. Gastrocnemius muscles from 6 and 32 month old ambulatory and hindlimb suspended rats were dissected and homogenized for protein abundance determination. Western blotting was performed with Decapping Protein 2 (DCP2) antibody to measure p-bodies abundance in the protein samples. DCP2 is a protein involved in decapping and degradation of mRNA and is a strong marker for pbodies. Bands from Western blots were analyzed based on their optical density value, which is directly proportional to the abundance of DCP2 protein. We found that DCP2 was significantly more abundant in 32 month old compared to 6 month old rats. However, no significant difference was observed in the abundance of DCP2 between ambulatory and hindlimb suspended rats at either age. Therefore, we concluded that p-bodies are elevated with age-associated muscle atrophy, but not with disuse. Future studies will be directed toward determining whether other components of p-bodies are elevated and investigating the functional significance of increased presence of p-bodies.