Rho kinase inhibition protects CA1 cells in organotypic hippocampal slices during in vitro ischemia.
The actin cytoskeleton is a dynamic superstructure that regulates multiple cellular functions and that has been implicated in cell death regulation. We investigated whether modulating the neuronal actin cytoskeleton polymerization by Rho-GTPase kinase (ROCK) inhibition influences cell death in hippocampal neuronal cultures and in murine organotypic hippocampal slice cultures subjected to in vitro ischemia (IVI). During IVI, spines on vehicle treated hippocampal neurons collapsed and large dendritic actin aggregates were formed. Following ROCK inhibition by Y27632, the actin aggregates were markedly smaller while large filopodia extended from the dendritic trunk. Y27632 also provided strong neuroprotection of hippocampal pyramidal CA1 neurons, which was of similar magnitude as protection by NMDA receptor blockade. Likewise, treatment with the F-actin depolymerizing agent latrunculin during IVI diminished actin aggregation and mitigated cell death following IVI. We propose that ROCK inhibition protects neurons against ischemic damage by disrupting actin polymerization thereby mitigating NMDA receptor induced toxicity and releasing ATP bound to actin for cellular energy use. We conclude that ROCK inhibitors abrogate multiple detrimental processes and could therefore be useful in stroke therapy.
Gisselsson
Lennart
L
Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, Lund University, BMC A13, S-22184 Lund, Sweden.
Toresson
Håkan
H
Ruscher
Karsten
K
Wieloch
Tadeusz
T
D000199:Actins / Q000235:genetics / Q000378:metabolism; D000577:Amides / Q000494:pharmacology; D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy / Q000201:enzymology / Q000503:physiopathology*; D056547:CA1 Region, Hippocampal / Q000187:drug effects / Q000201:enzymology / Q000503:physiopathology*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D003712:Dendrites / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D011554:Pseudopodia / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D011725:Pyridines / Q000494:pharmacology; D013997:Time Factors; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism*
D000199:Actins; D000577:Amides; D004791:Enzyme Inhibitors; D011725:Pyridines; C108830:Y 27632; D054460:rho-Associated Kinases