Involvement of cytoskeleton-associated proteins in the commitment of C3H10T1/2 pluripotent stem cells to adipocyte lineage induced by BMP2/4.
The developmental pathway that gives rise to mature adipocytes involves two distinct stages: commitment and terminal differentiation. Although the important proteins/factors contributing to terminal adipocyte differentiation have been well defined, the proteins/factors in the commitment of mesenchymal stem cells to the adipocyte lineage cells have not. In this study, we applied proteomics analysis profiling to characterize differences between uncommitted C3H10T1/2 pluripotent stem cells and those that have been committed to the adipocyte lineage by BMP4 or BMP2 with the goal to identify such proteins/factors and to understand the molecular mechanisms that govern the earliest stages of adipocyte lineage commitment. Eight proteins were found to be up-regulated by BMP2, and 27 proteins were up-regulated by BMP4, whereas five unique proteins were up-regulated at least 10-fold by both BMP2/4, including three cytoskeleton-associated proteins (i.e. lysyl oxidase (LOX), translationally controlled tumor protein 1 (TPT1), and αB-crystallin). Western blotting further confirmed the induction of the expression of these cytoskeleton-associated proteins in the committed C3H10T1/2 induced by BMP2/4. Importantly, knockdown of LOX expression totally prevented the commitment, whereas knockdown of TPT1 and αB-crystallin expression partially inhibited the commitment. Several published reports suggest that cell shape can influence the differentiation of partially committed precursors of adipocytes, osteoblasts, and chondrocytes. We observed a dramatic change of cell shape during the commitment process, and we showed that knockdown of these cytoskeleton-associated proteins prevented the cell shape change and restored F-actin organization into stress fibers and inhibited the commitment to the adipocyte lineage. Our studies indicate that these differentially expressed cytoskeleton-associate proteins might determine the fate of mesenchymal stem cells to commit to the adipocyte lineage through cell shape regulation.
Huang
Hai-Yan
HY
The Key Laboratory of Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, China.
Hu
Ling-Ling
LL
Song
Tan-Jing
TJ
Li
Xi
X
He
Qun
Q
Sun
Xia
X
Li
Yi-Ming
YM
Lu
Hao-Jie
HJ
Yang
Peng-Yuan
PY
Tang
Qi-Qun
QQ
D000199:Actins / Q000378:metabolism; D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology*; D055415:Bone Morphogenetic Protein 4 / Q000494:pharmacology*; D019070:Cell Lineage / Q000187:drug effects*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D055785:Gene Knockdown Techniques; D051379:Mice; D039904:Pluripotent Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D008249:Protein-Lysine 6-Oxidase / Q000378:metabolism; D040901:Proteomics; D015203:Reproducibility of Results; D015398:Signal Transduction / Q000187:drug effects; D000090324:Tumor Protein, Translationally-Controlled 1; D015854:Up-Regulation / Q000187:drug effects; D038203:alpha-Crystallin B Chain / Q000378:metabolism
D000199:Actins; D014408:Biomarkers, Tumor; D055396:Bone Morphogenetic Protein 2; D055415:Bone Morphogenetic Protein 4; D003598:Cytoskeletal Proteins; D016326:Extracellular Matrix Proteins; C000715648:Tpt1 protein, mouse; D000090324:Tumor Protein, Translationally-Controlled 1; D038203:alpha-Crystallin B Chain; C077112:Lox protein, mouse; D008249:Protein-Lysine 6-Oxidase