scholarly journals Neuroprotective Role of the Nrf2 Pathway in Subarachnoid Haemorrhage and Its Therapeutic Potential

2019 ◽  
Vol 2019 ◽  
pp. 1-21 ◽  
Author(s):  
Ardalan Zolnourian ◽  
Ian Galea ◽  
Diederik Bulters

The mechanisms underlying poor outcome following subarachnoid haemorrhage (SAH) are complex and multifactorial. They include early brain injury, spreading depolarisation, inflammation, oxidative stress, macroscopic cerebral vasospasm, and microcirculatory disturbances. Nrf2 is a global promoter of the antioxidant and anti-inflammatory response and has potential protective effects against all of these mechanisms. It has been shown to be upregulated after SAH, and Nrf2 knockout animals have poorer functional and behavioural outcomes after SAH. There are many agents known to activate the Nrf2 pathway. Of these, the actions of sulforaphane, curcumin, astaxanthin, lycopene,tert-butylhydroquinone, dimethyl fumarate, melatonin, and erythropoietin have been studied in SAH models. This review details the different mechanisms of injury after SAH including the contribution of haemoglobin (Hb) and its breakdown products. It then summarises the evidence that the Nrf2 pathway is active and protective after SAH and finally examines the evidence supporting Nrf2 upregulation as a therapy after SAH.

Author(s):  
Diana Hamdan ◽  
Lisa A. Robinson

Excessive infiltration of immune cells into the kidney is a key feature of acute and chronic kidney diseases. The family of chemokines are key drivers of this process. CX3CL1 (fractalkine) is one of two unique chemokines synthesized as a transmembrane protein which undergoes proteolytic cleavage to generate a soluble species. Through interacting with its cognate receptor, CX3CR1, CX3CL1 was originally shown to act as a conventional chemoattractant in the soluble form, and as an adhesion molecule in the transmembrane form. Since then, other functions of CX3CL1 beyond leukocyte recruitment have been described, including cell survival, immunosurveillance, and cell-mediated cytotoxicity. This review summarizes diverse roles of CX3CL1 in kidney disease and potential uses as a therapeutic target and novel biomarker. As the CX3CL1-CX3CR1 axis has been shown to contribute to both detrimental and protective effects in various kidney diseases, a thorough understanding of how the expression and function of CX3CL1 are regulated is needed to unlock its therapeutic potential.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Tao Tao ◽  
Guang-Jie Liu ◽  
Xuan Shi ◽  
Yan Zhou ◽  
Yue Lu ◽  
...  

Abstract Background Microglia are resident immune cells in the central nervous system and central to the innate immune system. Excessive activation of microglia after subarachnoid haemorrhage (SAH) contributes greatly to early brain injury, which is responsible for poor outcomes. Dehydroepiandrosterone (DHEA), a steroid hormone enriched in the brain, has recently been found to regulate microglial activation. The purpose of this study was to address the role of DHEA in SAH. Methods We used in vivo models of endovascular perforation and in vitro models of haemoglobin exposure to illustrate the effects of DHEA on microglia in SAH. Results In experimental SAH mice, exogenous DHEA administration increased DHEA levels in the brain and modulated microglial activation. Ameliorated neuronal damage and improved neurological outcomes were also observed in the SAH mice pretreated with DHEA, suggesting neuronal protective effects of DHEA. In cultured microglia, DHEA elevated the mRNA and protein levels of Jumonji d3 (JMJD3, histone 3 demethylase) after haemoglobin exposure, downregulated the H3K27me3 level, and inhibited the transcription of proinflammatory genes. The devastating proinflammatory microglia-mediated effects on primary neurons were also attenuated by DHEA; however, specific inhibition of JMJD3 abolished the protective effects of DHEA. We next verified that DHEA-induced JMJD3 expression, at least in part, through the tropomyosin-related kinase A (TrkA)/Akt signalling pathway. Conclusions DHEA has a neuroprotective effect after SAH. Moreover, DHEA increases microglial JMJD3 expression to regulate proinflammatory/anti-inflammatory microglial activation after haemoglobin exposure, thereby suppressing inflammation.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Liang Chen ◽  
Sun-Li Hu ◽  
Jun Xie ◽  
De-Yi Yan ◽  
She-Ji Weng ◽  
...  

The widespread use of therapeutic glucocorticoids has increased the frequency of glucocorticoid-induced osteoporosis (GIOP). One of the potential pathological processes of GIOP is an increased level of oxidative stress and mitochondrial dysfunction, which eventually leads to osteoblast apoptosis. Proanthocyanidins (PAC) are plant-derived antioxidants that have therapeutic potential against GIOP. In our study, a low dose of PAC was nontoxic to healthy osteoblasts and restored osteogenic function in dexamethasone- (Dex-) treated osteoblasts by suppressing oxidative stress, mitochondrial dysfunction, and apoptosis. Mechanistically, PAC neutralized Dex-induced damage in the osteoblasts by activating the Nrf2 pathway, since silencing Nrf2 partly eliminated the protective effects of PAC. Furthermore, PAC injection restored bone mass and promoted the expression of Nrf2 in the distal femur of Dex-treated osteoporotic rats. In summary, PAC protect osteoblasts against Dex-induced oxidative stress and mitochondrial dysfunction via the Nrf2 pathway activation and may be a promising drug for treating GIOP.


2021 ◽  
Vol 30 ◽  
pp. 096368972110332
Author(s):  
Weifeng Jiang ◽  
Jungang Song ◽  
Suitao Zhang ◽  
Yanyan Ye ◽  
Jun Wang ◽  
...  

Myocardial infarction (MI) is identified as the myocardial necrosis due to myocardial ischemia/reperfusion (I/R) injury and remains a leading cause of mortality. C1q/TNF-related protein 13 (CTRP13) is a member of CTRP family that has been found to be involved in coronary artery disease (CAD). However, the role of CTRP13 in MI remains unclear. We aimed to explore the functional role of CTRP13 in H9c2 cells exposed to hypoxia/reoxygenation (H/R). Our results demonstrated that H/R stimulation significantly decreased the expression of CTRP13 in H9c2 cells. H/R-induced an increase in ROS production and reductions in activities of SOD and CAT were prevented by CTRP13 overexpression but were aggravated by CTRP13 silencing. Moreover, CTRP13 overexpression could reverse the inductive effect of H/R on caspase-3 activity and bax expression, as well as the inhibitory effect of H/R on bcl-2 expression in H9c2 cells. However, CTRP13 silencing presented opposite effects with CTRP13 overexpression. Furthermore, CTRP13 overexpression enhanced the H/R-stimulated the expression levels of p-AMPK and nuclear Nrf2, and Nrf2 transcriptional activity. However, inhibition of AMPK reversed the CTRP13-mediated activation of Nrf2/ARE signaling and the cardiac-protective effect in H/R-exposed H9c2 cells. Additionally, silencing of Nrf2 reversed the protective effects of CTRP13 against H/R-stimulated oxidative stress and apoptosis in H9c2 cells. Finally, recombinant CTRP13 protein attenuated myocardial I/R-induced injury in rats. Taken together, these findings indicated that CTRP13 protected H9c2 cells from H/R-stimulated oxidative stress and apoptosis via regulating the AMPK/Nrf2/ARE signaling pathway. Our results provided evidence for the therapeutic potential of CTRP13 in myocardial I/R injury.


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiaofan Lai ◽  
Shaojie Huang ◽  
Sijia Lin ◽  
Lvya Pu ◽  
Yaqing Wang ◽  
...  

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive deadly fibrotic lung disease with high prevalence and mortality worldwide. The therapeutic potential of mesenchymal stem cells (MSCs) in pulmonary fibrosis may be attributed to the strong paracrine, anti-inflammatory, anti-apoptosis and immunoregulatory effects. However, the mechanisms underlying the therapeutic effects of MSCs in IPF, especially in terms of alveolar type 2 (AT2) cells senescence, are not well understood. The purpose of this study was to evaluate the role of MSCs in NAD metabolism and senescence of AT2 cells in vitro and in vivo. Methods MSCs were isolated from human bone marrow. The protective effects of MSCs injection in pulmonary fibrosis were assessed via bleomycin mouse models. The senescence of AT2 cells co-cultured with MSCs was evaluated by SA-β-galactosidase assay, immunofluorescence staining and Western blotting. NAD+ level and NAMPT expression in AT2 cells affected by MSCs were determined in vitro and in vivo. FK866 and NAMPT shRNA vectors were used to determine the role of NAMPT in MSCs inhibiting AT2 cells senescence. Results We proved that MSCs attenuate bleomycin-induced pulmonary fibrosis in mice. Senescence of AT2 cells was alleviated in MSCs-treated pulmonary fibrosis mice and when co-cultured with MSCs in vitro. Mechanistic studies showed that NAD+ and NAMPT levels were rescued in AT2 cells co-cultured with MSCs and MSCs could suppress AT2 cells senescence mainly via suppressing lysosome-mediated NAMPT degradation. Conclusions MSCs attenuate AT2 cells senescence by upregulating NAMPT expression and NAD+ levels, thus exerting protective effects in pulmonary fibrosis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Dan J. K. Yombo ◽  
Varshini Odayar ◽  
Nishant Gupta ◽  
Anil G. Jegga ◽  
Satish K. Madala

Idiopathic Pulmonary Fibrosis (IPF) is a severe fibrotic lung disease characterized by excessive collagen deposition and progressive decline in lung function. Th2 T cell-derived cytokines including IL-4 and IL-13 have been shown to contribute to inflammation and fibrotic remodeling in multiple tissues. Interleukin-31 (IL-31) is a newly identified cytokine that is predominantly produced by CD4 Th2 T cells, but its signaling receptor IL-31RA is primarily expressed by non-hematopoietic cells. However, the potential role of the IL-31-IL31RA axis in pulmonary inflammation and fibrosis has remained largely unknown. To determine the role of IL-31RA deficiency in pulmonary fibrosis, wildtype, and IL-31RA knockout mice were treated with bleomycin and measured changes in collagen deposition and lung function. Notably, the loss of IL-31 signaling attenuated collagen deposition and lung function decline during bleomycin-induced pulmonary fibrosis. The total lung transcriptome analysis showed a significant reduction in fibrosis-associated gene transcripts including extracellular matrix and epithelial cell-associated gene networks. Furthermore, the lungs of human IPF showed an elevated expression of IL-31 when compared to healthy subjects. In support, the percentage of IL-31 producing CD4+ T cells was greater in the lungs and PBMCs from IPF patients compared to healthy controls. Our findings suggest a pathogenic role for IL-31/IL-31RA signaling during bleomycin-induced pulmonary fibrosis. Thus, therapeutic targeting the IL-31-IL-31RA axis may prevent collagen deposition, improve lung function, and have therapeutic potential in pulmonary fibrosis.


Author(s):  
Alexander Luettich ◽  
Edit Franko ◽  
Desiree B. Spronk ◽  
Catherine Lamb ◽  
Rufus Corkill ◽  
...  

AbstractSubarachnoid haemorrhage (SAH) is associated with long-term disability, serious reduction in quality of life and significant mortality. Early brain injury (EBI) refers to the pathological changes in cerebral metabolism and blood flow that happen in the first few days after ictus and may lead on to delayed cerebral ischaemia (DCI). A disruption of the nitric oxide (NO) pathway is hypothesised as a key mechanism underlying EBI. A decrease in the alpha-delta power ratio (ADR) of the electroencephalogram has been related to cerebral ischaemia. In an experimental medicine study, we tested the hypothesis that intravenous sodium nitrite, an NO donor, would lead to increases in ADR. We studied 33 patients with acute aneurysmal SAH in the EBI phase. Participants were randomised to either sodium nitrite or saline infusion for 1 h. EEG measurements were taken before the start of and during the infusion. Twenty-eight patients did not develop DCI and five patients developed DCI. In the patients who did not develop DCI, we found an increase in ADR during sodium nitrite versus saline infusion. In the five patients who developed DCI, we did not observe a consistent pattern of ADR changes. We suggest that ADR power changes in response to nitrite infusion reflect a NO-mediated reduction in cerebral ischaemia and increase in perfusion, adding further evidence to the role of the NO pathway in EBI after SAH. Our findings provide the basis for future clinical trials employing NO donors after SAH.


2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Chichi Li ◽  
Jingye Pan ◽  
Lechi Ye ◽  
Honglei Xu ◽  
Beibei Wang ◽  
...  

Abstract Adipose-derived stem cells (ADSCs) have been shown to be beneficial in some pulmonary diseases, and the paracrine effect is the major mechanism underlying ADSC-based therapy. Autophagy plays a crucial role in maintaining stem cell homeostasis and survival. However, the role of autophagy in mediating ADSC paracrine effects has not been thoroughly elucidated. We examined whether ADSCs participate in lipopolysaccharide (LPS)-induced pulmonary microvascular endothelial cell (PMVEC) barrier damage in a paracrine manner and illuminated the role of autophagy in regulating ADSC paracrine effects. PMVECs and ADSCs with or without autophagy inhibition were cocultured without intercellular contact, and the microvascular barrier function was assessed after LPS treatment. ADSC paracrine function was evaluated by detecting essential growth factors for endothelial cells. For in vivo experiments, ADSCs with or without autophagy inhibition were transplanted into LPS-induced lung-injury mice, and lung injury was assessed. ADSCs significantly alleviated LPS-induced microvascular barrier injury. In addition, ADSC paracrine levels of VEGF, FGF, and EGF were induced by LPS treatment, especially in the coculture condition. Inhibiting autophagy weakened the paracrine function and the protective effects of ADSCs on microvascular barrier injury. Moreover, ADSC transplantation alleviated LPS-induced lung injury, and inhibiting autophagy markedly weakened the therapeutic effect of ADSCs on lung injury. Together, these findings show that ADSC paracrine effects play a vital protective role in LPS-induced pulmonary microvascular barrier injury. Autophagy is a positive mediating factor in the paracrine process. These results are helpful for illuminating the role and mechanism of ADSC paracrine effects and developing effective therapies in acute lung injury.


2021 ◽  
Author(s):  
Amelia U. Schirmer ◽  
Lucy M. Driver ◽  
Megan T. Zhao ◽  
Carrow I. Wells ◽  
Julie E. Pickett ◽  
...  

AbstractSerine/threonine kinase 3 (STK3) is an essential member of the highly conserved Hippo Tumor suppressor pathway which regulates Yes 1 Associated protein (YAP1) and TAZ. STK3 and its paralog STK4 initiate a phosphorylation cascade that regulate YAP1/TAZ activation and degradation, which is important for regulated cell growth and organ size. Deregulation of this pathway leads to hyper-activation of YAP1 in various cancers. Counter to the canonical tumor suppression role of STK3, we report that in the context of prostate cancer (PC), STK3 has a pro-tumorigenic role. Our investigation started with the observation that STK3, but not STK4, is frequently amplified in PC. A high STK3 expression is associated with decreased overall survival and positively correlates with androgen receptor (AR) activity in metastatic castrate resistant PC. XMU-MP-1, an STK3/4 inhibitor, slowed cell proliferation, spheroid growth and matrigel invasion in multiple models. Genetic depletion of STK3 decreased proliferation in several PC cell lines. In a syngeneic allograft model, STK3 loss slowed tumor growth kinetics in vivo and biochemical analysis suggest a mitotic growth arrest phenotype. To further probe the role of STK3 in PC, we identified and validated a new set of selective STK3 inhibitors, with enhanced kinase selectivity relative XMU-MP-1, that inhibited tumor spheroid growth and invasion. Consistent with the canonical role, inhibition of STK3 induced cardiomyocyte growth and had chemo-protective effects. Our results contend that STK3 has a non-canonical role in PC progression and inhibition of STK3 may have therapeutic potential for PC that merits further investigation.SignificanceOur findings illuminate a new actionable target for PC therapy that would traditionally be overlooked due to its canonical role as a tumor suppressor in other cancer types.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lina Chen ◽  
Yuan Guo ◽  
Shuiqing Qu ◽  
Kai Li ◽  
Ting Yang ◽  
...  

Background and Purpose: Ultrafine particulate matter (UFPM) induces oxidative stress (OS) and is considered to be a risk factor of myocardial ischemia (MI). Shengmai formula (SMF) is a traditional Chinese medicine with antioxidant properties and has been used to treat cardiovascular diseases for a long time. The aim of this study was to explore the protective role of SMF and the mechanism by which it prevents myocardial injury in UFPM-exposed rats with MI.Methods: An MI rat model was established. Animals were randomly divided into five groups: sham, UFPM + MI, SMF (1.08 mg/kg⋅d) + UFPM + MI, SMF (2.16 mg/kg⋅d) + UFPM + MI, and SMF (4.32 mg/kg⋅d) + UFPM + MI. SMF or saline was administrated 7 days before UFPM instillation (100 μg/kg), followed by 24 h of ischemia. Physiological and biochemical parameters were measured, and histopathological examinations were conducted to evaluate myocardial damage. We also explored the potential mechanism of the protective role of SMF using a system pharmacology approach and an in vitro myoblast cell model with small molecule inhibitors.Results: UFPM produced myocardial injuries on myocardial infarct size; serum levels of LDH, CK-MB, and cardiac troponin; and OS responses in the rats with MI. Pretreatment with SMF significantly attenuated these damages via reversing the biomarkers. SMF also improved histopathology induced by UFPM and significantly altered the PI3K/AKT/MAPK and OS signaling pathways. The expression patterns of Cat, Gstk1, and Cyba in the UFPM model group were reversed in the SMF-treated group. In in vitro studies, SMF attenuated UFPM-induced reactive oxygen species production, mitochondrial damage, and OS responses. The PI3K/AKT/p38 MAPK/Nrf2 pathway was significantly changed in the SMF group compared with that in the UFPM group, whereas opposite results were obtained for pathway inhibition.Conclusion: These findings indicate that SMF prevents OS responses and exerts beneficial effects against myocardial injury induced by UFPM + MI in rats. Furthermore, the PI3K/AKT/p38 MAPK/Nrf2 signaling pathway might be involved in the protective effects of SMF.


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