Prothrombin kringle-2 induces death of mesencephalic dopaminergic neurons in vivo and in vitro via microglial activation
| Autor: | Tae Hyong Kim, So Yoon Won, Eun Sook Chung, Soung Soo Kim, Young Cheul Chung, Sang H. Choi, Min Young Jin, Eugene Bok, Eun-Hye Joe, Sang Ryong Kim, Byung Kwan Jin, Hyung Hwan Baik |
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| Rok vydání: | 2009 |
| Předmět: |
MAP Kinase Signaling System
Dopamine Nitric Oxide Synthase Type II Substantia nigra Biology Proinflammatory cytokine Rats Sprague-Dawley Cellular and Molecular Neuroscience Thrombin Kringles medicine Animals Gliosis RNA Messenger Protein kinase A Cells Cultured Neuroinflammation Neurons CD11b Antigen Cyclooxygenase 2 Inhibitors Tyrosine hydroxylase Microglia Neurotoxicity Parkinson Disease medicine.disease Molecular biology Coculture Techniques Rats Substantia Nigra medicine.anatomical_structure nervous system Biochemistry Cyclooxygenase 2 Female Prothrombin Inflammation Mediators Nitric Oxide Synthase medicine.drug |
| Zdroj: | Journal of Neuroscience Research. |
| ISSN: | 1097-4547 0360-4012 |
| DOI: | 10.1002/jnr.22318 |
| Popis: | We have shown that prothrombin kringle-2 (pKr-2), a domain of human prothrombin distinct from thrombin could activate cultured rat brain microglia in vitro. However, little is known whether pKr-2-induced microglial activation could cause neurotoxicity on dopaminergic (DA) neurons in vivo. To address this question, pKr-2 was injected into the rat substantia nigra (SN). Tyrosine hydroxylase (TH) immunohistochemistry experiments demonstrate significant loss of DA neurons seven days after injection of pKr-2. In parallel, pKr-2-activated microglia were detected in the SN with OX-42 and OX-6 immunohistochemistry. Reverse transcription PCR and double-label immunohistochemistry revealed that activated microglia in vivo exhibit early and transient expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and several proinflammatory cytokines. The pKr-2-induced loss of SN DA neurons was partially inhibited by the NOS inhibitor N(G)-nitro-L-arginine methyl ester hydrochloride, and the COX-2 inhibitor DuP-697. Extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase and p38 mitogen-activated protein kinase were activated in the SN as early as 1 hr after pKr-2 injection, and localized within microglia. Inhibition of these kinases led to attenuation of mRNA expression of iNOS, COX-2 and several proinflammatory cytokines, and rescue of DA neurons in the SN. Intriguingly, following treatment with pKr-2 in vitro, neurotoxicity was detected exclusively in co-cultures of mesencephalic neurons and microglia, but not microglia-free neuron-enriched mesencephalic cultures, indicating that microglia are required for pKr-2 neurotoxicity. Our results strongly suggest that microglia activated by endogenous compound(s), such as pKr-2, are implicated in the DA neuronal cell death in the SN. |
| Databáze: | OpenAIRE |
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