Entinostat Improves Motor Function and Neuronal Damage Via Downregulating NLRP3 Inflammasome Activation After Spinal Cord Injury

Background: Spinal cord injury (SCI), a major public health problem, has no effective treatment. A large number of studies have confirmed that histone deacetylases (HDACs) are involved in the physiologic processes that occur following SCI. We tried to uncover the potential neuroprotective role of entinostat (a class I HDAC inhibitor) in SCI.Methods: We conducted a study on a preclinical mouse model of SCI and OGD-induced neuronal damage to present the role of entinostat by the analysis of motor function, histopathologic damage, local NLRP3 inflammasome activation, and neuronal damage.Results: The results showed that entinostat suppressed HDAC activation (including HDAC1 and HDAC3 expression), improved the grip strength and BMS score, spinal edema, cell death, and local NLRP3 inflammasome activation in the spinal cord following SCI. Furthermore, entinostat significantly increased OGD-inhibited neuronal activity and decreased PI-positive cells, HDAC activation, caspase-1 activation, IL-1β and IL-18 levels, and NLRP3 expression.Conclusion: In summary, we first documented that entinostat improved the motor function, histopathologic damage, and local inflammatory response and NLRP3 inflammasome activation in the spinal cord following SCI and also presented the neuroprotective role of OGD-induced neuronal damage via the NLRP3 inflammasome. Thus, our study has the potential to reveal the interaction between the HDAC and NLRP3 inflammasome in the pathologic process as well as SCI and further promote the clinical indications of HDACi entinostat and clinical treatment for the inflammatory response after SCI.

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Melatonin Alleviates Microglia-Mediated Neuroinflammation By Suppressing NLRP3 Inflammasome-Mediated Pyroptosis Via ROS/mtDNA/STING Pathway After Spinal Cord Injury

10.21203/rs.3.rs-716835/v1 ◽

2021 ◽

Author(s):

Jin Wang ◽

Haiyuan Yang ◽

Fan Zhang ◽

Minghao Shao ◽

Haocheng Xu ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Nlrp3 Inflammasome ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation ◽

Cord Injury ◽

Sting Pathway

Abstract BackgroundMicroglia pyroptosis-induced neuroinflammation has been one of the potential treatment targets for spinal cord injury (SCI). And melatonin is reported to have anti-neuroinflammation effect on SCI, but the underlying mechanism is largely unexplored. In addition, the potential regulatory role of stimulator of interferon genes (STING) mediated innate immune response in the SCI-induced neuroinflammation also remains unknown. The aim of this study is to identify the potential molecular mechanism of the anti-neuroinflammation effect of melatonin in SCI mice and to explore whether STING-mediated signal pathway is involved in this pharmacological process. MethodsIn vivo, the C57BL/6 female mice underwent SCI injury or Sham surgery (laminectomy alone). Melatonin and selective STING antagonist C-176 were administered intraperitoneally after injury in the SCI group once a day for 3 or 28 consecutive days for different experiments. The BMS score system was adopted to assess the motor function of mice. In vitro, the Lipopolysaccharide (LPS)/ATP was combinedly used to induce cell pyroptosis in BV2 microglia and the adenovirus was used to overexpress STING. A series of molecular experiments including Western blot (WB), quantitative real-time polymerase chain reaction (RT-qPCR), enzyme linked immunosorbent assay (ELISA) and immunofluorescence (IF) were performed in vivo and in vitro. ResultsOur results showed that melatonin effectively suppressed NLRP3 inflammasome-induced pyroptosis and STING-mediated pathway after SCI. In addition, C-176 also alleviated the NLRP3 inflammasome-mediated pyroptosis and promoted functional recovery in vivo. In vitro, we also found that melatonin abrogated NLRP3 inflammasome activation in LPS/ATP-induced BV2 cells, while overexpression of STING reversed the anti-pyroptotic role of melatonin. Subsequent results together indicated that the role of melatonin on STING-dependent NLRP3 inflammasome activation may be mediated by decreasing ROS production and cytosolic mtDNA release. ConclusionThis study preliminarily demonstrated that melatonin exerts its anti-neuroinflammation role on SCI by alleviating the NLRP3 inflammasome-mediated pyroptosis, which was mediated by blocking the ROS/mtDNA/STING pathway. It provides us a better understanding of the pathological mechanism after SCI and offer experiment evidence to promote the use of melatonin for SCI.

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Dopamine Reduced Pyroptosis and Improved Functional Recovery After Spinal Cord Injury

10.21203/rs.3.rs-75427/v1 ◽

2020 ◽

Author(s):

Liulong Zhu ◽

Guoming Ding ◽

Fan He ◽

Maoqiang Li ◽

Wu Jiang

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Inflammatory Response ◽

Functional Recovery ◽

Nlrp3 Inflammasome ◽

Molecular Mechanisms ◽

Neuronal Loss ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation ◽

Cord Injury

Abstract Background: Neuronal loss, demyelination, and an excessive inflammatory response accompany the pathogenesis of spinal cord injury (SCI). The inflammatory response is promoted by inflammasomes in variety diseases. Dopamine is a neurotransmitter that also functions as a regulator in NLRP3 (nucleotide-binding oligomerization domain-like receptor 3) inflammasome-dependent neuroinflammation. However, the effects and molecular mechanisms underlying the role of dopamine in SCI are little known. Methods:Functional recovery was assessed using Basso Mouse Scale (BMS) and BMS subscore. Histopathologic damage was evaluated by H&E staining. Demyelination was evaluated using immunofluorescence staining of myelin basic protein. Neuronal loss was evaluated by immunochemistry staining of NeuN. Pyroptosis was assessed by flow cytometry, western blot, and cell viability and cytotoxicity assays.Results: This study using mice showed that dopamine was significantly associated with enhanced locomotor recovery after SCI; with a reduction in NLRP3 inflammasome activation, pyroptosis, neuron and myelin loss, and histological changes. In vitro data suggested an association between dopamine and suppressed NLRP3 inflammasome activation and neuronal pyroptosis, and greater survival of neurons. Conclusion: Thus, dopamine may be a novel and effective approach for improving recovery after SCI.

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