The pivotal role of the NLRC4 inflammasome in neuroinflammation after intracerebral hemorrhage in rats

AbstractThe NLRC4 inflammasome, a member of the nucleotide-binding and oligomerization domain-like receptor (NLR) family, amplifies inflammation by facilitating the processing of caspase-1, interleukin (IL)–1β, and IL-18. We explored whether NLRC4 knockdown alleviated inflammatory injury following intracerebral hemorrhage (ICH). Furthermore, we investigated whether NLRC4 inflammasome activation can be adjusted by the regulator of G protein signaling 2/leucine-rich repeat kinase-2 pathway. Fifty microliters of arterial blood was drawn and injected into the basal ganglion to simulate the ICH model. NLRC4 small interfering RNAs (siRNAs) were utilized to knockdown NLRC4. An LRRK2 inhibitor (GNE7915) was injected into the abdominal cavity. Short hairpin (sh) RNA lentiviruses and lentiviruses containing RGS2 were designed and applied to knockdown and promote RGS2 expression. Neurological functions, brain edema, Western blot, enzyme-linked immunosorbent, hematoxylin and eosin staining, Nissl staining, immunoprecipitation, immunofluorescence assay and Evans blue dye extravasation and autofluorescence assay were evaluated. It was shown that the NLRC4 inflammasome was activated following ICH injury. NLRC4 knockdown extenuated neuronal death, damage to the blood-brain barrier, brain edema and neurological deficiency 3 days after ICH. NLRC4 knockdown reduced myeloperoxidase (MPO) cells as well as tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β and IL-18 following ICH. GNE7915 reduced pNLRC4 and NLRC4 inflammasome activation. RGS2 suppressed the interaction of LRRK2 and NLRC4 and NLRC4 inflammasome activation by regulating pLRRK2. Our study demonstrated that the NLRC4 inflammasome may aggravate the inflammatory injury induced by ICH and that RGS2/LRRK2 may relieve inflammatory injury by restraining NLRC4 inflammasome activation.

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The role of NLRC4 inflammasome on intracerebral hemorrhage-caused inflammation in rats

10.21203/rs.3.rs-44218/v1 ◽

2020 ◽

Author(s):

Hui Gan ◽

Li Zhang ◽

Hui Chen ◽

Han Xiao ◽

Lu Wang ◽

...

Keyword(s):

Intracerebral Hemorrhage ◽

Brain Edema ◽

Abdominal Cavity ◽

Blue Dye ◽

Inflammasome Activation ◽

Small Interfering Rnas ◽

Nissl Staining ◽

Inflammatory Injury ◽

Arterial Blood ◽

Lrrk2 Kinase

Abstract Background: The NLRC4 inflammasome, a member of nucleotide-binding and oligomerization domain-like receptor (NLR) family, amplifies the neuroinflammation by facilitating the processing of caspase-1, interleukin (IL)–1β and IL-18. We explored whether NLRC4 knockdown alleviated inflammatory injury following intracerebral hemorrhage (ICH). Furthermore, whether NLRC4 inflammasome activation can be adjusted by the RGS2/LRRK2 pathway was investigated.Methods: 50μl arterial blood was drawn and injected into basal ganglions to simulate the ICH model. NLRC4 small interfering RNAs(siRNA) were utilized to knockdown NLRC4. LRRK2 inhibitor (GNE7915) was injected into the abdominal cavity. Short hairpin (sh) RNA lentiviral and lentivirus containing RGS2 were designed and applied to knockdown and promote RGS2 expression. Neurological functions, brain edema, western blot, enzyme-linked immunosorbent, hematoxylin and eosin staining, nissl staining, immunoprecipitation, immunofluorescence assay and evans blue dye extravasation and autofluorescence assay were evaluated.Results: It was shown that the NLRC4 inflammasome was activated following ICH injury. NLRC4 knockdown extenuated neuronal death, damage of the blood-brain barrier, brain edema and neurological deficiencyat 3 d after ICH. NLRC4 knockdown reduced myeloperoxidase (MPO) cells as well as IL-1β and IL-18 following ICH. GNE7915 reduced LRRK2 kinase, the combination of LRRK2 and NLRC4 and NLRC4 inflammasome activation. RGS2 suppressed the combination of LRRK2 and NLRC4，and NLRC4 inflammasome activation though regulating LRRK2 Kinase Activity. Conclusion: Our study demonstrated that the NLRC4 inflammasome may aggravate the inflammatory injury induced by ICH and RGS2/LRRK2 may relieve inflammatory injury by restraining the NLRC4 inflammasome activation.

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Hydrochloride fasudil attenuates brain injury in ICH rats

Translational Neuroscience ◽

10.1515/tnsci-2020-0100 ◽

2020 ◽

Vol 11 (1) ◽

pp. 75-86

Author(s):

Limin Li ◽

Xiaoli Lou ◽

Kunlun Zhang ◽

Fangping Yu ◽

Yingchun Zhao ◽

...

Keyword(s):

Water Content ◽

Brain Edema ◽

Inflammatory Cytokines ◽

Neuronal Morphology ◽

Enzyme Linked Immunosorbent Assay ◽

Brain Water Content ◽

Nissl Staining ◽

Neuroprotective Effects ◽

Arterial Blood ◽

Brain Water

AbstractAimThe aim of this study was to investigate the neuroprotective effects of hydrochloride fasudil (HF) in rats following intracerebral hemorrhage (ICH).MethodsMale Wistar rats were randomly divided into four groups: normal, sham-operated, ICH, and ICH/HF. ICH was induced by injection of non-anticoagulant autologous arterial blood into the right caudate nucleus. The levels of Rho-associated protein kinase 2 (ROCK2) mRNA and protein around the site of the hematoma were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA), respectively. The levels of interleukin-6 and tumor necrosis factor-α in serum were detected by ELISA. The inflammatory cells and changes in the neuronal morphology around the hematoma were visualized using hematoxylin and eosin and Nissl staining. Brain edema was measured by comparing wet and dry brain weights.ResultsFollowing ICH, the levels of ROCK2 were significantly increased from day 1 to day 7. The levels of ROCK2 were significantly lower in rats treated with HF than in controls. The levels of inflammatory cytokines and brain water content were significantly higher in rats treated with HF than in controls. Administration of HF significantly reduced the levels of inflammatory cytokines and brain water content from day 1 to day 7. In the acute phase of ICH, a large number of neutrophils infiltrated the perihematomal areas. In comparison with the ICH group, the ICH/HF group showed markedly fewer infiltrating neutrophils on day 1. Nissl staining showed that ICH caused neuronal death and loss of neurons in the perihematomal areas at all time points and that treatment with HF significantly attenuated neuronal loss.ConclusionsHF exerts neuroprotective effects in ICH rats by inhibiting the expression of ROCK2, reducing neutrophil infiltration and production of inflammatory cytokines, decreasing brain edema, and attenuating loss of neurons.

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iTRAQ-Based Quantitative Proteomics Indicated Nrf2/OPTN-Mediated Mitophagy Inhibits NLRP3 Inflammasome Activation after Intracerebral Hemorrhage

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/6630281 ◽

2021 ◽

Vol 2021 ◽

pp. 1-26

Author(s):

Yijun Cheng ◽

Mingjian Liu ◽

Hao Tang ◽

Bin Chen ◽

Guoyuan Yang ◽

...

Keyword(s):

Survival Rate ◽

Intracerebral Hemorrhage ◽

Brain Edema ◽

Nlrp3 Inflammasome ◽

Neuronal Death ◽

Inflammasome Activation ◽

Secondary Brain Injury ◽

Clear Understanding ◽

Hematoma Volume ◽

Nlrp3 Inflammasome Activation

Intracerebral hemorrhage- (ICH-) induced secondary brain injury (SBI) is a very complex pathophysiological process. However, the molecular mechanisms and drug targets of SBI are highly intricate and still elusive, yet a clear understanding is crucial for the treatment of SBI. In the current study, we aimed to confirm that nuclear factor-E2-related factor 2 (Nrf2)/Optineurin- (OPTN-) mediated mitophagy alleviated SBI by inhibiting nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation based on the isobaric tag for relative and absolute quantization (iTRAQ) quantification proteomics. Human ICH brain specimens were collected for iTRAQ-based proteomics analysis. Male Nrf2 wild-type (WT) and knockout (KO) mice were employed to establish ICH murine models. The survival rate, hematoma volume, neurofunctional outcomes, blood-brain barrier (BBB) permeability, brain edema, spatial neuronal death, NLRP3 inflammasome, inflammatory response, mitochondrial function, and mitophagy level were evaluated after ICH. The iTRAQ quantification analysis showed that the differentially expressed proteins (DEPs), Nrf2 and NLRP3, were closely associated with the initiation and development of SBI after ICH. The Nrf2 KO mice had a significantly lower survival rate, bigger hematoma volume, worse neurological deficits, and increased BBB disruption, brain edema, and neuronal death when compared with the Nrf2 WT mice after ICH. Furthermore, Nrf2 KO enhanced NLRP3 inflammasome activation and neuroinflammation as evidenced by the NF-κB activation and various proinflammatory cytokine releases following ICH. Moreover, Nrf2 could interact with and modulate the mitophagy receptor OPTN, further mediating mitophagy to remove dysfunctional mitochondria after ICH. Furthermore, OPTN small interfering RNA (siRNA) increased the NLRP3 inflammasome activation by downregulating mitophagy level and enhancing mitochondrial damage in the Nrf2 WT mice after ICH. Together, our data indicated that Nrf2/OPTN inhibited NLRP3 inflammasome activation, possibly via modulating mitophagy, therefore alleviating SBI after ICH.

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Intracerebral Hematoma, Perihemorrhagic Edema and Urinary Excreted Cysteinyl Leukotrienes Correlation Study

Macedonian Medical Review ◽

10.2478/mmr-2014-0017 ◽

2014 ◽

Vol 68 (2) ◽

pp. 85-88

Author(s):

Natalija Dolnenec-Baneva ◽

Dijana Nikodijevic ◽

Gordana Kiteva-Trenchevska ◽

Igor Petrov ◽

Dragana Petrovska-Cvetkovska ◽

...

Keyword(s):

Intracerebral Hemorrhage ◽

Brain Edema ◽

Correlation Study ◽

Intracerebral Hematoma ◽

Moderate Correlation ◽

Hematoma Volume ◽

Cysteinyl Leukotrienes ◽

Edema Volume ◽

Perihemorrhagic Edema

AbstractIntroduction.Several mechanisms in formation of perihemorrhagic edema are activated after contact of brain tissue-extravasated blood in intracerebral hemorrhage. Cysteinyl leukotrienes (cysLT) (C4, D4, E4) are included in this process as significant edema factors and they determine the neurological deficit and outcome. The study aim was a 5-day follow-up (admission/3 day/5 day) of urinary cysLT, hematoma volume, edema volume values and their correlation in patients after spontaneous, primary supratentorial intracerebral hemorrhage.Methods.An enzyme immunoassay was used for urinary cysLT measured in 62 patients and 80 healthy controls. Hematoma and edema volumes were visualized and measured by computed tomography and mathematically calculated with a special spheroid shape formula (V=AxBxC/2).Results.CysLT of hemorrhagic patients (1842.20±1413.2, 1181.54±906.2, 982.30±774.2pg/ml/mg creatinine) were significantly excreted (p<0.01). Brain edema (12.86±13.5, 22.38±21.1, 28.45±29.4cm3) was significantly increased (p<0.01). Hematoma volume values (13.05±14.5, 13.13±14.7, 12.99±14.7cm3) were not significant (p>0.05). A high correlation (multiple regression) between cysLT, hematoma and edema was found on the 3rdday (R=0.6) and a moderate correlation at admission (R=0.3) and on the 5thday (R=0.3).Conclusion.In our 5-day follow-up study a significant cysLT brain synthesis and significant brain edema progression versus constant hematoma volume values in hemorrhagic patients was found. A high correlation between cysLT, hematoma and edema volume was found on the 3rdday, a moderate correlation on admission and on the 5thday, which means that high cysLT and hematoma values were associated with high/moderate edema values.

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Effects of Liangxue Tongyu Formula on brain edema and expressions of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in rats with intracerebral hemorrhage

Journal of Chinese Integrative Medicine ◽

10.3736/jcim20100408 ◽

2010 ◽

Vol 8 (4) ◽

pp. 347-351 ◽

Cited By ~ 2

Author(s):

CY He

Keyword(s):

Matrix Metalloproteinase ◽

Intracerebral Hemorrhage ◽

Brain Edema ◽

Matrix Metalloproteinase 9 ◽

Tissue Inhibitor Of Metalloproteinase ◽

Tissue Inhibitor ◽

Metalloproteinase 9

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Jagged1-mediated myeloid Notch1 signaling activates HSF1/Snail and controls NLRP3 inflammasome activation in liver inflammatory injury

Cellular and Molecular Immunology ◽

10.1038/s41423-019-0318-x ◽

2019 ◽

Vol 17 (12) ◽

pp. 1245-1256 ◽

Cited By ~ 7

Author(s):

Yuting Jin ◽

Changyong Li ◽

Dongwei Xu ◽

Jianjun Zhu ◽

Song Wei ◽

...

Keyword(s):

Liver Injury ◽

Inflammatory Response ◽

Immune Cell ◽

Ischemia Reperfusion ◽

Inflammasome Activation ◽

Inflammatory Injury ◽

Notch1 Signaling ◽

Caspase 1 ◽

Hepatocellular Damage ◽

Hepatocellular Apoptosis

AbstractNotch signaling plays important roles in the regulation of immune cell functioning during the inflammatory response. Activation of the innate immune signaling receptor NLRP3 promotes inflammation in injured tissue. However, it remains unknown whether Jagged1 (JAG1)-mediated myeloid Notch1 signaling regulates NLRP3 function in acute liver injury. Here, we report that myeloid Notch1 signaling regulates the NLRP3-driven inflammatory response in ischemia/reperfusion (IR)-induced liver injury. In a mouse model of liver IR injury, Notch1-proficient (Notch1FL/FL) mice receiving recombinant JAG1 showed a reduction in IR-induced liver injury and increased Notch intracellular domain (NICD) and heat shock transcription factor 1 (HSF1) expression, whereas myeloid-specific Notch1 knockout (Notch1M-KO) aggravated hepatocellular damage even with concomitant JAG1 treatment. Compared to JAG1-treated Notch1FL/FL controls, Notch1M-KO mice showed diminished HSF1 and Snail activity but augmented NLRP3/caspase-1 activity in ischemic liver. The disruption of HSF1 reduced Snail activation and enhanced NLRP3 activation, while the adoptive transfer of HSF1-expressing macrophages to Notch1M-KO mice augmented Snail activation and mitigated IR-triggered liver inflammation. Moreover, the knockdown of Snail in JAG1-treated Notch1FL/FL livers worsened hepatocellular functioning, reduced TRX1 expression and increased TXNIP/NLRP3 expression. Ablation of myeloid Notch1 or Snail increased ASK1 activation and hepatocellular apoptosis, whereas the activation of Snail increased TRX1 expression and reduced TXNIP, NLRP3/caspase-1, and ROS production. Our findings demonstrated that JAG1-mediated myeloid Notch1 signaling promotes HSF1 and Snail activation, which in turn inhibits NLRP3 function and hepatocellular apoptosis leading to the alleviation of IR-induced liver injury. Hence, the Notch1/HSF1/Snail signaling axis represents a novel regulator of and a potential therapeutic target for liver inflammatory injury.

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Resolution of brain edema in severe brain injury at controlled high and low intracranial pressures

Journal of Neurosurgery ◽

10.3171/jns.1984.61.4.0707 ◽

1984 ◽

Vol 61 (4) ◽

pp. 707-712 ◽

Cited By ~ 19

Author(s):

Meihong Cao ◽

He Lisheng ◽

Sun Shouzheng

Keyword(s):

Cerebrospinal Fluid ◽

Brain Injury ◽

Brain Edema ◽

External Ventricular Drainage ◽

Blue Dye ◽

Severe Brain Injury ◽

Content Type ◽

Intracranial Pressures ◽

Low Levels ◽

Cerebrospinal Fluid Protein

✓ A series of 87 patients with severe brain injury were studied. Intracranial pressure (ICP) monitoring and external ventricular drainage were used to control ICP at high and low levels. Clearance of ytterbium-169-labeled diethylenetriaminepentaacetic acid (169Yb-DTPA), Evans blue dye, and ventricular cerebrospinal fluid protein was measured at the two ICP levels over consecutive periods of 4 hours to confirm clearance of brain edema. The results support the hypothesis that brain edema is in part absorbed in the cerebrospinal fluid via transventricular flow.

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