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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Decreased MHC I expression in IFN gamma mutant mice alters synaptic elimination in the spinal cord after peripheral injury

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Victorio, Sheila C. S. [1] ; Cartarozzi, Luciana P. [1] ; Hell, Rafaela C. R. [1] ; Oliveira, Alexandre L. R. [1]
Total Authors: 4
[1] Univ Campinas UNICAMP, Inst Biol, Dept Anat Cell Biol Physiol & Biophys, BR-13083970 Campinas, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Web of Science Citations: 7

Background: The histocompatibility complex (MHC) class I expression in the central nervous system (CNS) regulates synaptic plasticity events during development and adult life. Its upregulation may be associated with events such as axotomy, cytokine exposition and changes in neuron electrical activity. Since IFN gamma is a potent inducer of the MHC I expression, the present work investigated the importance of this pro-inflammatory cytokine in the synaptic elimination process in the spinal cord, as well as the motor recovery of IFN-/-, following peripheral injury. Methods: The lumbar spinal cords of C57BL/6J (wild type) and IFN gamma(-/-) (mutant) mice, subjected to unilateral sciatic nerve transection, were removed and processed for immunohistochemistry and real time RT-PCR, while the sciatic nerves from animals subjected to unilateral crush, were submitted to immunohistochemistry and electron microscopy for counting of the axons. Gait recovery was monitored using the Cat Walk system. Newborn mice astrocyte primary cultures were established in order to study the astrocytic respose in the absence of the IFN. expression. Results: IFN gamma(-/-) mutant mice showed a decreased expression of MHC I and beta 2-microglobulin mRNA coupled with reduced synaptophysin immunolabelling in the lesioned spinal cord segment. Following unilateral nerve transection, the Iba-1 (ionized calcium binding adaptor molecule 1) and glial fibrillary acid protein (GFAP) reactivities increased equally in both strains. In vitro, the astrocytes demonstrated similar GFAP levels, but the proliferation rate was higher in the wild type mice. In the crushed nerves (distal stump), neurofilaments and p75NTR immunolabeling were upregulated in the mutant mice as compared to the wild type and an improvement in locomotor recovery was observed. Conclusion: The present results show that a lack of IFN. affects the MHC I expression and the synaptic elimination process in the spinal cord. Such changes, however, do not delay peripheral nerve regeneration after nerve injury. (AU)

FAPESP's process: 12/06310-9 - Decreased MHC I expression in IFN gamma mutant mice alters synaptic elimination in the spinal cord after peripheral injury
Grantee:Alexandre Leite Rodrigues de Oliveira
Support Opportunities: Regular Research Grants - Publications - Scientific article
FAPESP's process: 09/07443-0 - Peripheral nerve regeneration after sciatic nerve tubulization and treatment with beta interferon
Grantee:Luciana Politti Cartarozzi
Support Opportunities: Scholarships in Brazil - Scientific Initiation
FAPESP's process: 10/05370-2 - Role of glial reactivity and expression of MHC class I in the maintenance of neuronal circuits in vitro
Grantee:Rafaela Chitarra Rodrigues Hell
Support Opportunities: Scholarships in Brazil - Post-Doctorate