Role of Rho GTPase in astrocyte morphology and migratory response during in vitro wound healing.
Small Rho GTPases are key regulators of the cytoskeleton in a great variety of cells. Rho function mediates morphological changes as well as locomotor activity. Using astrocyte cultures established from neonatal mice we investigated the role of Rho in process formation during astrocyte stellation. Using a scratch-wound model, we examined the impact of Rho on a variety of morphological and functional variables such as stellation and migratory activity during wound healing. C3 proteins are widely used to study cellular Rho functions. In addition, C3 derived from Clostridium botulinum (C3bot) is considered selectively to promote neuronal regeneration. Because the latter requires a balanced activity of neurones and glial cells, the effects of C3 protein on glial cells such as astrocytes have to be considered carefully. Low nanomolar concentrations of C3 proteins significantly promoted process outgrowth and increased process branching. Besides enzymatic inactivation of Rho by ADP-ribosylation, changes in protein levels of the various Rho GTPases may also contribute to the observed effects. Furthermore, incubation of scratch-wounded astrocyte cultures with C3bot accelerated wound healing. By inhibiting the Rho downstream effector ROCK with the selective inhibitor Y27632 we were able to demonstrate that the accelerated wound closure resulted from both enhanced polarized process formation and increased migratory activity of astrocytes into the lesion site. These results suggest that Rho negatively regulates astrocytic process growth and migratory responses after injury and that its inactivation by C3bot in nanomolar concentrations promotes astrocyte migration.
Höltje
Markus
M
Charité-Universitätsmedizin Berlin, Centrum für Anatomie, AG Funktionelle Zellbiologie, Humboldt-Universität zu Berlin, Berlin, Germany. markus.hoeltje@charite.de
Hoffmann
Anja
A
Hofmann
Fred
F
Mucke
Christian
C
Grosse
Gisela
G
Van Rooijen
Nico
N
Kettenmann
Helmut
H
Just
Ingo
I
Ahnert-Hilger
Gudrun
G
D000577:Amides / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000166:cytology* / Q000187:drug effects; D001921:Brain / Q000166:cytology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D049109:Cell Proliferation / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003176:Complement C3 / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005455:Fluorescent Antibody Technique / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007211:Indoles; D007770:L-Lactate Dehydrogenase; D037102:Lectins / Q000378:metabolism; D008081:Liposomes / Q000494:pharmacology; D051379:Mice; D011725:Pyridines / Q000494:pharmacology; D011994:Recombinant Proteins / Q000494:pharmacology; D013778:Tetrazolium Salts; D013997:Time Factors; D014945:Wound Healing / Q000187:drug effects / Q000502:physiology*; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism; D020741:rho GTP-Binding Proteins / Q000502:physiology*
C110656:2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium; D000577:Amides; D003176:Complement C3; D004791:Enzyme Inhibitors; D005904:Glial Fibrillary Acidic Protein; D007211:Indoles; D037102:Lectins; D008081:Liposomes; D011725:Pyridines; D011994:Recombinant Proteins; D013778:Tetrazolium Salts; C108830:Y 27632; C007293:DAPI; D007770:L-Lactate Dehydrogenase; D020764:cdc42 GTP-Binding Protein; D020741:rho GTP-Binding Proteins