Developmental patterns of caspase-3, bax and bcl-2 proteins expression in the human spinal ganglia.
The distribution of the bcl-2, bax and caspase-3 proteins was investigated in the cells of developing human spinal ganglia. Paraffin sections of 10 human conceptuses between 5th and 9th gestational weeks were analysed morphologically, immunohistochemically and by TUNEL-method. Cells positive to caspase-3 had brown stained nuclei or nuclear fragmentations. At earliest stages, 6% of ganglion population were caspase-3 positive cells. Later on, a significant increase in number of caspase-3 positive cells appeared, particularly in the ventral part of ganglia (12%), and subsequently decreased to 6%. TUNEL-positive cells had the same distribution pattern as caspase-3 positive cells. Bax-positive cells followed the developmental pattern similar to caspase-3 cells, changing in range between 20% and 32%. There were 8% of bcl-2 positive cells at earliest stages. They increased significantly in dorsal part of the ganglion during the 7th week (28%), and than dropped to 15% by the end of the 8th week. These findings suggest a ventro-dorsal course of development in human spinal ganglia. Number of bcl-2, bax and caspase-3 positive cells changed in a temporally and spatially restricted manner, coincidently with ganglion differentiation. While apoptosis might control cell number, bcl-2 could act in suppression of apoptosis and enhancement of cell differentiation.
Vukojevic
Katarina
K
Department of Anatomy, Histology and Embryology, School of Medicine, University of Split, 21000 Split, Croatia. kvukojev@bsb.mefst.hr
Carev
Dominko
D
Sapunar
Damir
D
Petrovic
Danijel
D
Saraga-Babic
Mirna
M
D053148:Caspase 3 / Q000378:metabolism*; D004789:Enzyme Activation; D005455:Fluorescent Antibody Technique; D005727:Ganglia, Spinal / Q000166:cytology / Q000196:embryology* / Q000201:enzymology*; D005865:Gestational Age; D006801:Humans; D007150:Immunohistochemistry; D008853:Microscopy; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D053148:Caspase 3