Limits...
Proteasome dysfunction induces muscle growth defects and protein aggregation.

Kitajima Y, Tashiro Y, Suzuki N, Warita H, Kato M, Tateyama M, Ando R, Izumi R, Yamazaki M, Abe M, Sakimura K, Ito H, Urushitani M, Nagatomi R, Takahashi R, Aoki M - J. Cell. Sci. (2014)

Bottom Line: The ubiquitin-proteasome and autophagy-lysosome pathways are the two major routes of protein and organelle clearance.The autophagy pathway was upregulated, but the process of autophagosome formation was impaired.Our results suggest that appropriate proteasomal activity is important for muscle growth and for maintaining myofiber integrity in collaboration with autophagy pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.

Show MeSH

Related in: MedlinePlus

Catabolic pathways in the gastrocnemius muscles of Rpt3−/− mice. (A) Immunoblotting analysis for the detection of muscle atrophy-related signaling pathway components. (B) Quantification of the data from A. The amount of phosphorylated p38 (pp38) was also increased in Rpt3−/− mice. No apparent differences were observed in the levels of Akt and phosphorylated (p)Akt. Foxo3a, p50, and myostatin were increased. Phosphorylated (p)Foxo3a, p70S6K1, phosphorylated (p)S6, S6, phosphorylated (p)4EBP1, 4EBP1 and GAPDH were also present. The ratios of phosphorylated S6∶S6 and phosphorylated 4EBP1∶4EBP1 were not altered, whereas the total amount of phosphorylated 4EBP1 was increased. Data show the mean+s.e.m.; *P<0.05 (Student's t-test). (C) Proteins related to RNA metabolism accumulated in myofibers. Expression of the FUS/TLS, VCP and TDP-43 proteins was increased in Rpt3−/− mice, especially in the insoluble fractions. (D) Immunohistochemistry of TDP-43, FUS/TLS and VCP revealed that the amount of these markers localizing within myonuclei in Rpt3−/− mice was increased. TOTO3, nuclei; OVL, overlay. Scale bars: 20 µm (upper panel), 50 µm (middle and lower panels).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4265737&req=5

f07: Catabolic pathways in the gastrocnemius muscles of Rpt3−/− mice. (A) Immunoblotting analysis for the detection of muscle atrophy-related signaling pathway components. (B) Quantification of the data from A. The amount of phosphorylated p38 (pp38) was also increased in Rpt3−/− mice. No apparent differences were observed in the levels of Akt and phosphorylated (p)Akt. Foxo3a, p50, and myostatin were increased. Phosphorylated (p)Foxo3a, p70S6K1, phosphorylated (p)S6, S6, phosphorylated (p)4EBP1, 4EBP1 and GAPDH were also present. The ratios of phosphorylated S6∶S6 and phosphorylated 4EBP1∶4EBP1 were not altered, whereas the total amount of phosphorylated 4EBP1 was increased. Data show the mean+s.e.m.; *P<0.05 (Student's t-test). (C) Proteins related to RNA metabolism accumulated in myofibers. Expression of the FUS/TLS, VCP and TDP-43 proteins was increased in Rpt3−/− mice, especially in the insoluble fractions. (D) Immunohistochemistry of TDP-43, FUS/TLS and VCP revealed that the amount of these markers localizing within myonuclei in Rpt3−/− mice was increased. TOTO3, nuclei; OVL, overlay. Scale bars: 20 µm (upper panel), 50 µm (middle and lower panels).

Mentions: To obtain an overall view of the gene expression profiles in Rpt3−/− skeletal muscle, microarray and real-time PCR analyses of gastrocnemius muscle tissue were performed (Fig. 5E,F; primers are listed in supplementary material Table S1). Proteasome-related genes were upregulated in Rpt3−/− mice; a summary of the top ten networks identified by Ingenuity pathway analysis of the microarray data revealed that ‘connective tissue proliferation’, ‘cellular development’ and ‘protein synthesis’ were all affected in Rpt3−/− mice (supplementary material Table S2). The microarray data are available online (GEO; http://www.ncbi.nlm.nih.gov/geo/) under the accession number GSE34896. A pathway analysis using DAVID online software provided by the National Institute of Allergy and Infectious Diseases (NIAID), NIH (http://david.abcc.ncifcrf.gov/home.jsp) was performed. A KEGG pathway analysis using the list of genes that were differentially expressed over 1.5-fold compared with their expression in Rpt3+/+ mice is shown in supplementary material Table S3. Proteasome- and lysosome-related genes were significantly upregulated, as was the MAPK pathway in Rpt3−/− mice (supplementary material Table S3). The protein level of phosphorylated p38 was increased in the gastrocnemius muscle of the Rpt3−/− mice (Fig. 7A).


Proteasome dysfunction induces muscle growth defects and protein aggregation.

Kitajima Y, Tashiro Y, Suzuki N, Warita H, Kato M, Tateyama M, Ando R, Izumi R, Yamazaki M, Abe M, Sakimura K, Ito H, Urushitani M, Nagatomi R, Takahashi R, Aoki M - J. Cell. Sci. (2014)

Catabolic pathways in the gastrocnemius muscles of Rpt3−/− mice. (A) Immunoblotting analysis for the detection of muscle atrophy-related signaling pathway components. (B) Quantification of the data from A. The amount of phosphorylated p38 (pp38) was also increased in Rpt3−/− mice. No apparent differences were observed in the levels of Akt and phosphorylated (p)Akt. Foxo3a, p50, and myostatin were increased. Phosphorylated (p)Foxo3a, p70S6K1, phosphorylated (p)S6, S6, phosphorylated (p)4EBP1, 4EBP1 and GAPDH were also present. The ratios of phosphorylated S6∶S6 and phosphorylated 4EBP1∶4EBP1 were not altered, whereas the total amount of phosphorylated 4EBP1 was increased. Data show the mean+s.e.m.; *P<0.05 (Student's t-test). (C) Proteins related to RNA metabolism accumulated in myofibers. Expression of the FUS/TLS, VCP and TDP-43 proteins was increased in Rpt3−/− mice, especially in the insoluble fractions. (D) Immunohistochemistry of TDP-43, FUS/TLS and VCP revealed that the amount of these markers localizing within myonuclei in Rpt3−/− mice was increased. TOTO3, nuclei; OVL, overlay. Scale bars: 20 µm (upper panel), 50 µm (middle and lower panels).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4265737&req=5

f07: Catabolic pathways in the gastrocnemius muscles of Rpt3−/− mice. (A) Immunoblotting analysis for the detection of muscle atrophy-related signaling pathway components. (B) Quantification of the data from A. The amount of phosphorylated p38 (pp38) was also increased in Rpt3−/− mice. No apparent differences were observed in the levels of Akt and phosphorylated (p)Akt. Foxo3a, p50, and myostatin were increased. Phosphorylated (p)Foxo3a, p70S6K1, phosphorylated (p)S6, S6, phosphorylated (p)4EBP1, 4EBP1 and GAPDH were also present. The ratios of phosphorylated S6∶S6 and phosphorylated 4EBP1∶4EBP1 were not altered, whereas the total amount of phosphorylated 4EBP1 was increased. Data show the mean+s.e.m.; *P<0.05 (Student's t-test). (C) Proteins related to RNA metabolism accumulated in myofibers. Expression of the FUS/TLS, VCP and TDP-43 proteins was increased in Rpt3−/− mice, especially in the insoluble fractions. (D) Immunohistochemistry of TDP-43, FUS/TLS and VCP revealed that the amount of these markers localizing within myonuclei in Rpt3−/− mice was increased. TOTO3, nuclei; OVL, overlay. Scale bars: 20 µm (upper panel), 50 µm (middle and lower panels).
Mentions: To obtain an overall view of the gene expression profiles in Rpt3−/− skeletal muscle, microarray and real-time PCR analyses of gastrocnemius muscle tissue were performed (Fig. 5E,F; primers are listed in supplementary material Table S1). Proteasome-related genes were upregulated in Rpt3−/− mice; a summary of the top ten networks identified by Ingenuity pathway analysis of the microarray data revealed that ‘connective tissue proliferation’, ‘cellular development’ and ‘protein synthesis’ were all affected in Rpt3−/− mice (supplementary material Table S2). The microarray data are available online (GEO; http://www.ncbi.nlm.nih.gov/geo/) under the accession number GSE34896. A pathway analysis using DAVID online software provided by the National Institute of Allergy and Infectious Diseases (NIAID), NIH (http://david.abcc.ncifcrf.gov/home.jsp) was performed. A KEGG pathway analysis using the list of genes that were differentially expressed over 1.5-fold compared with their expression in Rpt3+/+ mice is shown in supplementary material Table S3. Proteasome- and lysosome-related genes were significantly upregulated, as was the MAPK pathway in Rpt3−/− mice (supplementary material Table S3). The protein level of phosphorylated p38 was increased in the gastrocnemius muscle of the Rpt3−/− mice (Fig. 7A).

Bottom Line: The ubiquitin-proteasome and autophagy-lysosome pathways are the two major routes of protein and organelle clearance.The autophagy pathway was upregulated, but the process of autophagosome formation was impaired.Our results suggest that appropriate proteasomal activity is important for muscle growth and for maintaining myofiber integrity in collaboration with autophagy pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan Department of Medicine and Science in Sports and Exercise, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan.

Show MeSH
Related in: MedlinePlus