Neuroprotective role of Nrf2 on hypoxic-ischemic brain injury in neonatal mice

Myricetin attenuates hypoxic-ischemic brain damage in neonatal rats via NRF2 signaling pathway

Introduction: Hypoxic-ischemic encephalopathy (HIE) is a crucial cause of neonatal death and neurological sequelae, but currently there is no effective therapy drug for HIE. Both oxidative stress and apoptosis play critical roles in the pathological development of HIE. Myricetin, a naturally extracted flavonol compound, exerts remarkable effects against oxidative stress, apoptosis, and inflammation. However, the role and underlying molecular mechanism of myricetin on HIE remain unclear. Methods: In this study, we established the neonatal rats hypoxic-ischemic (HI) brain damage model in vivo and CoCl₂ induced PC1₂ cell model in vitro to explore the neuroprotective effects of myricetin on HI injury, and illuminate the potential mechanism. Results: Our results showed that myricetin intervention could significantly reduce brain infarction volume, glia activation, apoptosis, and oxidative stress marker levels through activating NRF2 (Nuclear factor-E2-related factor 2) and increase the expressions of NRF2 downstream proteins NQO-1 and HO-1. In addition, the NRF2 inhibitor ML385 could significantly reverse the effects of myricetin. Conclusion: This study found that myricetin might alleviate oxidative stress and apoptosis through NRF2 signaling pathway to exert the protective role for HI injury, which suggested that myricetin might be a promising therapeutic agent for HIE.

The NRF2-Dependent Transcriptional Regulation of Antioxidant Defense Pathways: Relevance for Cell Type-Specific Vulnerability to Neurodegeneration and Therapeutic Intervention

Oxidative stress has been implicated in the etiology and pathobiology of various neurodegenerative diseases. At baseline, the cells of the nervous system have the capability to regulate the genes for antioxidant defenses by engaging nuclear factor erythroid 2 (NFE2/NRF)-dependent transcriptional mechanisms, and a number of strategies have been proposed to activate these pathways to promote neuroprotection. Here, we briefly review the biology of the transcription factors of the NFE2/NRF family in the brain and provide evidence for the differential cellular localization of NFE2/NRF family members in the cells of the nervous system. We then discuss these findings in the context of the oxidative stress observed in two neurodegenerative diseases, Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS), and present current strategies for activating NFE2/NRF-dependent transcription. Based on the expression of the NFE2/NRF family members in restricted populations of neurons and glia, we propose that, when designing strategies to engage these pathways for neuroprotection, the relative contributions of neuronal and non-neuronal cell types to the overall oxidative state of tissue should be considered, as well as the cell types which have the greatest intrinsic capacity for producing antioxidant enzymes.

Administration of Nrf-2-Modified Hair-Follicle MSCs Ameliorates DSS-Induced Ulcerative Colitis in Rats

Ulcerative colitis (UC) is a common chronic nonspecific intestinal inflammation of unknown etiology associated with a low cure rate and a high relapse rate. Hair follicle mesenchymal stem cells (HF-MSCs) are a class of pluripotent stem cells that have differentiation potential and strong proliferation ability. Nuclear factor red system related factor (Nrf-2) is a key factor in the oxidative stress response. Dextran sulfate sodium- (DSS-) induced rat UC models closely mimic human UC in terms of symptoms and histological changes. Animals were divided into five groups, including a healthy group and UC model rats treated with normal saline, Nrf-2, HF-MSCs, or Nrf-2-expressing HF-MSC group. Based on the expression of intestinal stem cells, inflammatory factors, anti-inflammatory factors, and disease activity index scores, Nrf-2-expressing HF-MSCs had the most obvious therapeutic effect under the same treatment regimen. This study provided a new potential clinical treatment option for ulcerative colitis.

LncRNA NEAT1 promotes nucleus pulposus cell matrix degradation through regulating Nrf2/ARE axis

Background

This study aimed to assess the role and mechanism of lncRNA NEAT1 in intervertebral disc degeneration (IVD).

Methods

LncRNA profile (GSE56081) between IVD and healthy control was downloaded from the Gene Expression Omnibus (GEO) database and analyzes differential lncRNA expression. Expression of lncRNA NEAT1 in IVD tissue and TNF-α/IL-1β-stimulated nucleus pulposus cells were further measured by RT-PCR. The lncRNA NEAT1 overexpression plasmids (pcDNA-NEAT1) were constructed and transfected into nucleus pulposus cells. Catabolic biomarkers (MMP-3 and MMP-13), anabolic biomarkers (Col II and Aggrecan) and Nrf2 expression were further measured. To further investigate the function of Nrf2, nucleus pulposus cells were pretreated with or without 25 μM tert-Butylhydroquinone (TBHQ), a Nrf2 activator, for 18 h and subsequently cotreated with pcDNA-NEAT1.

Results

A total of 1432 lncRNAs were differentially expressed in GSE56081. Bioinformatic analysis found that these lncRNAs mainly enriched in Nrf2/ARE signaling pathway. LncRNA NEAT1 was highly expressed in IVD tissues than that of healthy control. Moreover, TNF-α/IL-1β induced a time- and dose-dependent increase in the mRNA expression of lncRNA NEAT1 in the nucleus pulposus cells. Overexpression of lncRNA NEAT1 abates promotes nucleus pulposus cells proliferation but induces matrix degradation. Meanwhile, nucleus and cytoplasm Nrf2 expression was significantly down-regulated by lncRNA NEAT1 upregulation. Nrf2 activator (TBHQ) could partially reverse the inhibitory effects of overexpression of lncRNA NEAT1 on matrix degradation.

Conclusion

Collectively, our data unveiled the lncRNA NEAT1 promotes matrix degradation by regulating Nrf2/ARE signaling pathway, suggesting a potential therapeutic for IVD in the future.