title: Inhibition of the microglial response is essential for the neuroprotective effects of Rho-kinase inhibitors on MPTP-induced dopaminergic cell death.
abstract: Several recent studies have shown that activation of the RhoA/Rho-associated kinase (ROCK) pathway is involved in the MPTP-induced dopaminergic cell degeneration and possibly in Parkinson's disease. ROCK inhibitors have been suggested as candidate neuroprotective drugs for Parkinson's disease. However, the mechanism responsible for the increased survival of dopaminergic neurons after treatment with ROCK inhibitors is not clear. We exposed primary (neuron-glia) mesencephalic cultures, cultures of the MES 23.5 dopaminergic neuron cell line and primary mesencephalic cultures lacking microglial cells to the dopaminergic neurotoxin MPP+ and the ROCK inhibitor Y-27632 in order to study the effects of ROCK inhibition on dopaminergic cell loss and the length of neurites of surviving dopaminergic neurons. In primary (neuron-glia) cultures, simultaneous treatment with MPP+ and the ROCK inhibitor significantly reduced the loss of dopaminergic neurons. In the absence of microglia, treatment with the ROCK inhibitor did not induce a significant reduction in the dopaminergic cell loss. Treatment with the ROCK inhibitor induced a significant decrease in axonal retraction in primary cultures with and without microglia and in cultures of the MES 23.5 neuron cell line. In conclusion, inhibition of microglial ROCK is essential for the neuroprotective effects of ROCK inhibitors against cell death induced by the dopaminergic neurotoxin MPP+. In addition, ROCK inhibition induced a direct effect against axonal retraction in surviving neurons. However, the latter effect was not sufficient to cause a significant increase in the survival of dopaminergic neurons after treatment with MPP+.
authors.affiliation: Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Borrajo
authors.affiliation: Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain.
authors.forename: Ana I
authors.initials: AI
authors.lastname: Rodriguez-Perez
authors.affiliation: Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Villar-Cheda
authors.affiliation: Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Guerra
authors.affiliation: Laboratory of Neuroanatomy and Experimental Neurology, Dept. of Morphological Sciences, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain; Networking Research Center on Neurodegenerative Diseases (CIBERNED), Spain. Electronic address: joseluis.labandeira@usc.es.
authors.forename: Jose L
authors.initials: JL
authors.lastname: Labandeira-Garcia
mesh_terms: D000577:Amides / Q000494:pharmacology*; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D018929:Cell Culture Techniques; D016923:Cell Death / Q000187:drug effects* / Q000502:physiology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D059290:Dopaminergic Neurons / Q000187:drug effects* / Q000473:pathology / Q000502:physiology; D020267:MPTP Poisoning / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D008636:Mesencephalon / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D017628:Microglia / Q000187:drug effects* / Q000201:enzymology; D016501:Neurites / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D018696:Neuroprotective Agents / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000577:Amides; D018696:Neuroprotective Agents; D011725:Pyridines; C108830:Y 27632; D054460:rho-Associated Kinases
keywords: Dopamine; Microglia; Neuroinflammation; Neuroprotection; Parkinson; Rho