Anti-apoptotic function of thymosin-beta in developing chick spinal motoneurons.
Thymosin-betas (Tbetas) are water-soluble peptides abundantly present in the cytoplasm and extracellular compartment. The functions of Tbetas appear to be pleiotrophic, including actin-remodeling, wound healing, angiogenesis, etc. In the present study, we present the evidence that Tbetas have anti-apoptotic activity on developing chick motoneurons (MNs) in vivo. Using in ovo electroporation, we introduced three isoforms of Tbeta (Tbeta4, Tbeta10, and Tbeta15) and found the significantly diminished normal and limb bud removal (LBR)-induced programmed cell death. Such anti-apoptotic activity is independent of Tbeta's actin remodeling activity. On the other hand, overexpression of Tbetas substantially reduced early cell death initiation signal, such as phosphorylation of c-Jun. Collectively, these results suggest that Tbetas may prevent apoptosis of neurons via blockade of early apoptogenic signals independent of actin remodeling action.
Choi
So Yoen
SY
Department of Anatomy, Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul 136-705, Republic of Korea.
Kim
Dong Ki
DK
Eun
Bokkee
B
Kim
Kyungjin
K
Sun
Woong
W
Kim
Hyun
H
D000199:Actins / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D002642:Chick Embryo; D018507:Gene Expression Regulation, Developmental; D018878:Limb Buds / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D009046:Motor Neurons / Q000166:cytology* / Q000378:metabolism*; D010766:Phosphorylation; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D051381:Rats; D013116:Spinal Cord / Q000166:cytology* / Q000196:embryology* / Q000378:metabolism; D013947:Thymosin / Q000235:genetics / Q000378:metabolism*
D000199:Actins; D016755:Proto-Oncogene Proteins c-jun; D013947:Thymosin