Inhibition of microRNA-155 Alleviates Neurological Dysfunction Following Transient Global Ischemia and Contribution of Neuroinflammation and Oxidative Stress in the Hippocampus

2020 ◽  
Vol 25 (40) ◽  
pp. 4310-4317 ◽  
Author(s):  
Lichao Sun ◽  
Shouqin Ji ◽  
Jihong Xing

Background/Aims: Central pro-inflammatory cytokine (PIC) signal is involved in neurological deficits after transient global ischemia induced by cardiac arrest (CA). The present study was to examine the role of microRNA- 155 (miR-155) in regulating IL-1β, IL-6 and TNF-α in the hippocampus of rats with induction of CA. We further examined the levels of products of oxidative stress 8-isoprostaglandin F2α (8-iso PGF2α, indication of oxidative stress); and 8-hydroxy-2’-deoxyguanosine (8-OHdG, indication of protein oxidation) after cerebral inhibition of miR-155. Methods: CA was induced by asphyxia and followed by cardiopulmonary resuscitation in rats. ELISA and western blot analysis were used to determine the levels of PICs and products of oxidative stress; and the protein expression of NADPH oxidase (NOXs) in the hippocampus. In addition, neurological severity score and brain edema were examined to assess neurological functions. Results: We observed amplification of IL-1β, IL-6 and TNF-α along with 8-iso PGF2α and 8-OHdG in the hippocampus of CA rats. Cerebral administration of miR-155 inhibitor diminished upregulation of PICs in the hippocampus. This also attenuated products of oxidative stress and upregulation of NOX4. Notably, inhibition of miR-155 improved neurological severity score and brain edema and this was linked to signal pathways of PIC and oxidative stress. Conclusion: We showed the significant role of blocking miR-155 signal in improving the neurological function in CA rats likely via inhibition of signal pathways of neuroinflammation and oxidative stress, suggesting that miR-155 may be a target in preventing and/or alleviating development of the impaired neurological functions during CA-evoked global cerebral ischemia.

2020 ◽  
Vol 10 (2) ◽  
pp. 204589402092212
Author(s):  
Yan Zhou ◽  
Lianjie Zhang ◽  
Jingjing Guan ◽  
Xin Yin

Lung ischemia–reperfusion injury (LIRI) is a common clinical concern. As the injury occurs, the pulmonary afferent nerves play a key role in regulating respiratory functions under pathophysiological conditions. The present study was to examine the effects of inhibiting microRNA-155 on the levels of proinflammatory cytokines and products of oxidative stress in the pulmonary vagal afferent nerves and the commissural nucleus of the solitary tract (cNTS) after LIRI. A rat model of LIRI was used. ELISA method was employed to examine proinflammatory cytokines, namely, IL-1β, IL-6 and TNF-α; and key biomarkers of oxidative stress, 8-isoprostaglandin F2α (8-iso PGF2α) and 8-hydroxy-2′-deoxyguanosine (8-OHdG). In results, in the process of LIRI, the levels of microRNA-155 were amplified in the vagal afferent nerves and cNTS, and this was accompanied with increases of IL-1β, IL-6 and TNF-α; and 8-iso PGF2α and 8-OHdG. Application of microRNA-155 inhibitor, but not its scramble, attenuated the elevation of proinflammatory cytokines and amplification of 8-iso PGF2α and 8-OHdG in those nerve tissues. In conclusion, we observed the abnormalities in the pulmonary afferent pathways at the levels of the peripheral nerves and brainstem, which is likely to affect respiratory functions as LIRI occurs. Our data suggest that blocking microRNA-155 signal pathways plays a beneficial role in regulating LIRI via inhibiting responses of neuroinflammation and oxidative stress signal pathways to LIRI.


2020 ◽  
Vol 17 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Yan Wang ◽  
Wei Lv ◽  
Yueyang Li ◽  
Dandan Liu ◽  
Xiuting He ◽  
...  

Background: Neuroinflammation and oxidative stress have significant effects on cognitive deficiency in the pathophysiological development of Alzheimer’s disease (AD). In the present study, we studied the influences of Ampelopsin (AMP) on proinflammatory cytokines (PICs, IL-1β, IL-6 and TNF-α), and products of oxidative stress 8-isoprostaglandin F2α (8-iso PGF2α, a product of oxidative stress); and 8-hydroxy-2’-deoxyguanosine (8-OHdG, a key biomarker of protein oxidation) in the hippocampus using a rat model of AD. Methods: ELISA was used to examine PICs and oxidative stress production; and western blotting to examine NADPH oxidase (NOXs). The Spatial working memory tests and Morris water maze were utilized to assess cognitive functions. Results: We observed amplification of IL-1β, IL-6 and TNF-α as well as 8-iso PGF2α and 8-OHdG in the hippocampus of AD rats. AMP attenuated upregulation of PICs and oxidative stress production. AMP also inhibited NOX4 in the AD rat hippocampus. Notably, AMP mostly improved learning performance in AD rat and this was linked to signal pathways of PIC and oxidative stress. Conclusion: AMP plays a significant role in improving the memory deficiency in AD rats via inhibition of signal pathways of neuroinflammation and oxidative stress, suggesting that AMP is likely to prospect in preventing and relieving development of the cognitive dysfunctions in AD as a complementary alternative intervention.


2011 ◽  
Vol 300 (3) ◽  
pp. F700-F706 ◽  
Author(s):  
Rifat Sabuhi ◽  
Quaisar Ali ◽  
Mohammad Asghar ◽  
Najah Riesh Hadi Al-Zamily ◽  
Tahir Hussain

Inflammation and oxidative stress are believed to contribute to hypertension in obesity/diabetes. Recently, we reported a role for the AT2 receptor in blood pressure control in obese Zucker rats. However, the role of AT2 receptors in inflammation and oxidative stress in obesity is not known. Therefore, in the present study, we tested the effects of the AT2 receptor agonist CGP-42112A on inflammation and oxidative stress in obese Zucker rats and compared them in their lean counterparts. Rats were systemically treated with either vehicle (control) or CGP-42112A (1 μg·kg−1·min−1; osmotic pump) for 2 wk. Markers of inflammation (CRP, MCP-1, TNF-α, and IL-6) and oxidative stress (HO-1, gp-91phox) as well as an antioxidant (SOD) were determined. Control obese rats had higher plasma levels of CRP, MCP-1, TNF-α, IL-6, and HO-1 compared with control lean rats. Conversely, plasma SOD activity was lower in control obese than in control lean rats. Furthermore, the protein levels of TNF-α and gp-91phox were higher in the kidney cortex of control obese rats. Interestingly, CGP-42112A treatment in obese rats reduced the plasma and kidney cortex inflammatory (TNF-α, IL-6) and oxidative stress (gp-91phox) markers and increased plasma SOD activity to the levels seen in lean control rats. However, CGP-42112A treatment in lean rats increased inflammatory (TNF-α, IL-6) and oxidative stress (gp-91phox) markers in the plasma and kidney cortex. Our present studies suggest anti-inflammatory and antioxidative functions of AT2 receptor in obese Zucker rats but proinflammatory and prooxidative functions in lean Zucker rats.


2016 ◽  
Vol 39 (2) ◽  
pp. 511-520 ◽  
Author(s):  
Jihong Xing ◽  
Jian Lu

Background/Aims: This study was to examine the role played by hypoxia inducible factor-1 (HIF-1α) in regulating pro-inflammatory cytokines (PICs) pathway in the rat hippocampus after cardiac arrest (CA) induced-transient global ischemia followed by cardiopulmonary resuscitation (CPR). Those PICs include interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Methods: A rat model of CA induced by asphyxia was used in the current study. Following CPR, the hippocampus CA1 region was obtained for ELISA to determine the levels of HIF-1α and PICs; and Western Blot analysis to determine the protein levels of PIC receptors. Results: Our data show that IL-1β, IL-6 and TNF-α were significant elevated in the hippocampus after CPR as compared with control group. This was companied with increasing of HIF-1α and the time courses for HIF-1α and PICs were similar. In addition, PIC receptors, namely IL-1R, IL-6R and TNFR1 were upregulated in CA rats. Also, stimulation of HIF-1α by systemic administration of ML228, HIF-1α activator, significantly attenuated the amplified IL-6/IL-6R and TNF-α /TNFR1 pathway in the hippocampus of CA rats, but did not modify IL-1β and its receptor. Moreover, ML228 attenuated upregulated expression of Caspase-3 indicating cell apoptosis evoked by CA. Conclusion: Transient global ischemia induced by CA increases the levels of IL-1β, IL-6 and TNF-α and thereby leads to enhancement in their respective receptor in the rat hippocampus. Stabilization of HIF-1α plays a role in attenuating amplified expression IL-6R, TNFR1 and Caspase-3 in the processing of transient global ischemia. Results of our study suggest that PICs contribute to cerebral injuries evoked by transient global ischemia and in this pathophysiological process activation of HIF-1α improves tissues against ischemic injuries. Our data revealed specific signaling pathways in alleviating CA-evoked global cerebral ischemia by elucidating that HIF-1α plays an important role in regulating PIC signal pathways and Caspase-3. The subsequent induction of HIF-1α and its target signals is likely a part of the intrinsic neuroprotective effects aimed at attenuating damage as a result of global cerebral ischemia. Thus, targeting one or more of these signaling molecules has clinical implications for treatment and improvement of CA-evoked global cerebral ischemia often observed in clinics.


2012 ◽  
Vol 21 (4) ◽  
pp. 151-157 ◽  
Author(s):  
Keun-Young Ryu ◽  
Geum-Sil Cho ◽  
Hua Zi Piao ◽  
Won-Ki Kim

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiao-Ming Jiang ◽  
Jing-Hai Hu ◽  
Lu-Lu Wang ◽  
Chi Ma ◽  
Xu Wang ◽  
...  

AbstractUlinastatin [urinary trypsin inhibitor (UTI)] plays an important role in the protection of organs against ischemic injury during severe inflammation. The purposes of this study were to examine the effects of UTI on the levels of pro-inflammatory cytokines (PICs) and protein expression of PIC receptors in the neocortex and hippocampus CA1 region of rats after transient global ischemia induced via cardiac arrest (CA). Specifcally, interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were analyzed. CA was induced by asphyxia followed by cardiopulmonary resuscitation in rats. ELISA and western blot analysis were employed to determine PICs and their receptors in the neocortex and hippocampus. Our results show that IL-1β, IL-6 and TNF-α were significantly elevated in the neocortex and hippocampal CA1 field after CA. This was accompanied with an increase in PIC receptors, namely IL-1R, IL-6R and TNFR1. Systemic injection of UTI attenuated the amplification of PIC signal pathways in these brain regions. UTI also improved the modified Neurological Severity Score and brain tissue edema in CA rats. Notably, UTI resulted in an increase in survival of CA rats as compared to CA rats without treatment. In conclusion, UTI plays a beneficial role in modulating transient global ischemia induced by CA by altering PIC signal mechanisms, but further studies are needed to draw more firm conclusions.


2019 ◽  
Vol 19 (8) ◽  
pp. 597-604
Author(s):  
Li Pang ◽  
Shouqin Ji ◽  
Jihong Xing

Background: Central pro-inflammatory cytokine (PIC) signal is involved in neurological deficits after transient global ischemia induced by cardiac arrest (CA). The present study was to examine if blocking acid sensing ion channels (ASICs) using amiloride in the Central Nervous System can alleviate neurological deficits after the induction of CA and further examine the participation of PIC signal in the hippocampus for the effects of amiloride. Methods: CA was induced by asphyxia and then cardiopulmonary resuscitation was performed in rats. Western blot analysis and ELISA were used to determine the protein expression of ASIC subunit ASIC1 in the hippocampus, and the levels of PICs. As noted, it is unlikely that this procedure is clinically used although amiloride and other pharmacological agents were given into the brain in this study. Results: CA increased ASIC1 in the hippocampus of rats in comparison with control animals. This was associated with the increase in IL-1β, IL-6 and TNF-α together with Caspase-3 and Caspase-9. The administration of amiloride into the lateral ventricle attenuated the upregulation of Caspase-3/Caspase-9 and this further alleviated neurological severity score and brain edema. Inhibition of central IL-6 and TNF-α also decreased ASIC1 in the hippocampus of CA rats. Conclusion: Transient global ischemia induced by CA amplifies ASIC1a in the hippocampus likely via PIC signal. Amiloride administered into the Central Nervous System plays a neuroprotective role in the process of global ischemia. Thus, targeting ASICs (i.e., ASIC1a) is suggested for the treatment and improvement of CA-evoked global cerebral ischemia.


2020 ◽  
Vol 17 (4) ◽  
pp. 394-401
Author(s):  
Yuanhua Wu ◽  
Yuan Huang ◽  
Jing Cai ◽  
Donglan Zhang ◽  
Shixi Liu ◽  
...  

Background: Ischemia/reperfusion (I/R) injury involves complex biological processes and molecular mechanisms such as autophagy. Oxidative stress plays a critical role in the pathogenesis of I/R injury. LncRNAs are the regulatory factor of cerebral I/R injury. Methods: This study constructs cerebral I/R model to investigate role of autophagy and oxidative stress in cerebral I/R injury and the underline regulatory mechanism of SIRT1/ FOXO3a pathway. In this study, lncRNA SNHG12 and FOXO3a expression was up-regulated and SIRT1 expression was down-regulated in HT22 cells of I/R model. Results: Overexpression of lncRNA SNHG12 significantly increased the cell viability and inhibited cerebral ischemicreperfusion injury induced by I/Rthrough inhibition of autophagy. In addition, the transfected p-SIRT1 significantly suppressed the release of LDH and SOD compared with cells co-transfected with SIRT1 and FOXO3a group and cells induced by I/R and transfected with p-SNHG12 group and overexpression of cells co-transfected with SIRT1 and FOXO3 further decreased the I/R induced release of ROS and MDA. Conclusion: In conclusion, lncRNA SNHG12 increased cell activity and inhibited oxidative stress through inhibition of SIRT1/FOXO3a signaling-mediated autophagy in HT22 cells of I/R model. This study might provide new potential therapeutic targets for further investigating the mechanisms in cerebral I/R injury and provide.


2013 ◽  
Vol 8 (4) ◽  
pp. 266-277 ◽  
Author(s):  
Diego Duarte ◽  
Kamila Silva ◽  
Mariana Rosales ◽  
José Lopes de Faria ◽  
Jacqueline Lopes de Faria

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