Molecular chaperone alphaB-crystallin is expressed in the human fetal telencephalon at midgestation by a subset of progenitor cells.
Alphab-crystallin (CRYAB) is a small heat shock protein with a chaperoning activity that is present in the postnatal healthy human brain in oligodendrocytes and in a few astrocytes. The involvement of CRYAB in cell differentiation, proliferation, signaling, cytoskeletal assembly, and apoptosis in various model systems has suggested that it might also play a role in the developing human brain. We analyzed the distribution and the levels of this molecular chaperone in healthy and polygenetically compromised (Down syndrome [DS]) human telencephalon at midgestation. We demonstrate that CRYAB is expressed in a temporospatial pattern by numerous radial glial cells and some early oligodendrocyte progenitors, including dividing cells, as well as a few astroglial cells in both healthy and DS fetal brains. We also found abundant phosphorylation of CRYAB at Ser-59, which mediates its antiapoptotic and cytoskeletal functions. There was only marginal phosphorylation at Ser-45.In contrast to our earlier study in young DS subjects, upregulation of phosphorylated CRYAB occurred rarely in DS fetuses. The distribution, the timing of appearance, and the results of colocalization studies suggest that CRYAB assists in the biological processes associated with developmental remodeling/differentiation and proliferation of select subpopulations of progenitor cells in human fetal brain at midgestation.
Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA. Elizabeth.Kida@omr.state.ny.us
Elizabeth
E
Kida
Teresa
T
Wierzba-Bobrowicz
Sonia
S
Palminiello
Kulbir
K
Kaur
Katarzyna
K
Jarzabek
Marius
M
Walus
Giorgio
G
Albertini
Adam A
AA
Golabek
D000367:Age Factors; D004314:Down Syndrome / Q000473:pathology*; D053595:Embryonic Stem Cells / Q000145:classification / Q000378:metabolism*; D005333:Fetus; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005865:Gestational Age; D006801:Humans; D009419:Nerve Tissue Proteins / Q000378:metabolism; D010766:Phosphorylation; D012694:Serine / Q000378:metabolism; D013687:Telencephalon / Q000196:embryology* / Q000473:pathology*; D038203:alpha-Crystallin B Chain / Q000378:metabolism*
D009419:Nerve Tissue Proteins; D038203:alpha-Crystallin B Chain; D012694:Serine