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1.
Cell Rep ; 43(2): 113776, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38367237

RESUMO

Microglia-mediated synaptic plasticity after CNS injury varies depending on injury severity, but the mechanisms that adjust synaptic plasticity according to injury differences are largely unknown. This study investigates differential actions of microglia on essential spinal motor synaptic circuits following different kinds of nerve injuries. Following nerve transection, microglia and C-C chemokine receptor type 2 signaling permanently remove Ia axons and synapses from the ventral horn, degrading proprioceptive feedback during motor actions and abolishing stretch reflexes. However, Ia synapses and reflexes recover after milder injuries (nerve crush). These different outcomes are related to the length of microglia activation, being longer after nerve cuts, with slower motor-axon regeneration and extended expression of colony-stimulating factor type 1 in injured motoneurons. Prolonged microglia activation induces CCL2 expression, and Ia synapses recover after ccl2 is deleted from microglia. Thus, microglia Ia synapse removal requires the induction of specific microglia phenotypes modulated by nerve regeneration efficiencies. However, synapse preservation was not sufficient to restore the stretch-reflex function.


Assuntos
Axônios , Microglia , Regeneração Nervosa , Receptores de Quimiocinas , Transdução de Sinais
2.
Cells ; 11(13)2022 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-35805167

RESUMO

Peripheral nerve injuries induce a pronounced immune reaction within the spinal cord, largely governed by microglia activation in both the dorsal and ventral horns. The mechanisms of activation and response of microglia are diverse depending on the location within the spinal cord, type, severity, and proximity of injury, as well as the age and species of the organism. Thanks to recent advancements in neuro-immune research techniques, such as single-cell transcriptomics, novel genetic mouse models, and live imaging, a vast amount of literature has come to light regarding the mechanisms of microglial activation and alluding to the function of microgliosis around injured motoneurons and sensory afferents. Herein, we provide a comparative analysis of the dorsal and ventral horns in relation to mechanisms of microglia activation (CSF1, DAP12, CCR2, Fractalkine signaling, Toll-like receptors, and purinergic signaling), and functionality in neuroprotection, degeneration, regeneration, synaptic plasticity, and spinal circuit reorganization following peripheral nerve injury. This review aims to shed new light on unsettled controversies regarding the diversity of spinal microglial-neuronal interactions following injury.


Assuntos
Neuralgia , Traumatismos dos Nervos Periféricos , Animais , Camundongos , Microglia , Doenças Neuroinflamatórias , Medula Espinal
3.
Int J Infect Dis ; 104: 510-525, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33385583

RESUMO

BACKGROUND: Human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV) are substantial public health threats in the region of Central Asia and the Caucasus, where the prevalence of these infections is currently rising. METHODS: A systematic review of MEDLINE, Embase and PsycINFO was conducted with no publication date or language restrictions through October 2019. Additional data were also harvested from national surveillance reports, references found in discovered sources, and other "grey" literature. It included studies conducted on high-risk populations (people who inject drugs (PWID), female sex workers (FSW), men who have sex with men (MSM), prisoners, and migrants) in Central Asia: Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan; and the Caucasus: Armenia, Azerbaijan, Georgia, and Northern Caucasus region of the Russian Federation. RESULTS: Wide ranges were noted for HIV prevalence: PWID 0-30.1%, MSM 0-25.1%, prisoners 0-22.8%, FSW 0-10.0%, and migrants 0.06-1.5%, with the highest prevalence of these high-risk groups reported in Kazakhstan (for PWID), Georgia (for MSM and prisoners) and Uzbekistan (for migrants). HCV prevalence also had a wide range: PWID 0.3-92.1%, MSM 0-18.9%, prisoners 23.8-49.7%, FSW 3.3-17.8%, and migrants 0.5-26.5%, with the highest prevalence reported in Georgia (92.1%), Kyrgyzstan (49.7%), and migrants from Tajikistan and Uzbekistan (26.5%). Similarly, HBV prevalence had a wide range: PWID 2.8-79.7%, MSM 0-22.2%, prisoners 2.7-6.2%, FSW 18.4% (one study), and migrants 0.3-15.7%. CONCLUSION: In Central Asia and the Caucasus, prevalence of HIV, HCV and HBV remains exceedingly high among selected populations, notably PWID and MSM.


Assuntos
Infecções por HIV/epidemiologia , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Ásia Central/epidemiologia , Feminino , Homossexualidade Masculina , Humanos , Masculino , Prevalência , Prisioneiros , Fatores de Risco , Federação Russa/epidemiologia , Profissionais do Sexo , Minorias Sexuais e de Gênero , Transtornos Relacionados ao Uso de Substâncias/complicações , Transcaucásia/epidemiologia
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