Nrf2 inhibits NLRP3 inflammasome activation through regulating Trx1/TXNIP complex in cerebral ischemia reperfusion injury.

The nod-like receptor protein 3 (NLRP3) inflammasome has a critical role in inflammation damage in ischemic injury, and the activation of the inflammasome is closely related to the interaction with thioredoxin interacting protein (TXNIP), which dissociates from the thioredoxin1 (Trx1)/TXNIP complex under oxidative stress. However, the negative regulator of NLRP3 inflammasome activation has not been fully investigated. Nuclear factor erythroid 2-related factor 2 (Nrf2) takes on a critical part in the antioxidant stress system, that controls the driven genes of antioxidant response element (ARE). Activate Nrf2 could inhibit the activation of NLRP3 inflammasome in acute liver injury and severe lupus nephritis. We aimed to explore the protective effect of Nrf2 in inhibiting the NLPR3 inflammasome formulation through the Trx1/TXNIP complex in cerebral ischemia reperfusion (cerebral I/R) injury. Middle cerebral artery occlusion/reperfusion (MCAO/R) model was used to imitate ischemic insult. Nrf2 was activated by tert-butylhydroquinone (tBHQ) intraperitoneally (i.p.) injection (16.7mg/kg), Nrf2,Trx1 and NLRP3 siRNAs were infused into the left paracele (12μl per rat), protein and mRNA levels were assessed by Western blot, qRT-PCR. ELISA was used for IL-1β and IL-18 activity measurements. After upregulating Nrf2, the expression of TXNIP in cytoplasm, NLRP3 inflammasome, and downstream factors caspase-1, IL-18, and IL-1β were significantly reduced, and Nrf2 knockdown yielded the opposite results. Trx1 knockdown produced the same effect of Nrf2 inhibition and the protective effect of Nrf2 was mostly abolished. Our results suggested that Nrf2 acted as a protective regulator against NLRP3 inflammasome activation by regulating the Trx1/TXNIP complex, which could possibly represent an innovative insight into the treatment of ischemia and reperfusion injury.

Hou Y ，Wang Y ，He Q ，Li L ，Xie H ，Zhao Y ，Zhao J ... -  《-》

mROS-TXNIP axis activates NLRP3 inflammasome to mediate renal injury during ischemic AKI.

Ischemia/reperfusion (I/R) is a critical risk factor for acute kidney injury (AKI). Recent studies provided evidence that tubular epithelial cells (TEC)-associated inflammation aggravates kidney injury and impairs tissue repair after I/R injury. Here we demonstrated that the Nod-like receptor protein 3 (NLRP3) inflammasome is activated by mitochondrial reactive oxygen species (mROS) during I/R injury via direct interactions between the inflammasome and thioredoxin-interacting protein (TXNIP). Firstly, we found that NLRP3 inflammasome activation was induced by I/R injury, peaking at day 3 after reperfusion. Consistent with this observation, NLRP3 deletion significantly attenuated I/R-induced kidney damage and markers of inflammasome activation. Then, we observed mitochondrial dysfunction, characterized by ultrastructural changes and cytochrome C (Cyt c) redistribution. Mitochondria-targeted antioxidant MitoTEMPO prevented mROS overproduction and the decline in mitochondrial membrane potential (MMP) in vitro. MitoTEMPO treatment also inhibited NLRP3 inflammasome activation and co-localization of NLRP3 and TXNIP after simulated ischemia/reperfusion (SI/R) injury. Finally, we transfected HK-2 cells with TXNIP siRNA to explore the role of TXNIP in mROS-induced NLRP3 inflammasome activation. We found that TXNIP siRNA significantly inhibited NLRP3 inflammasome activation. These results demonstrate that NLRP3 inflammasome is activated through the mROS-TXNIP-NLRP3 pathway and provide a potential therapeutic target in ischemic AKI.

Wen Y ，Liu YR ，Tang TT ，Pan MM ，Xu SC ，Ma KL ，Lv LL ，Liu H ，Liu BC ... -  《-》

Dl-3-n-Butylphthalide Inhibits NLRP3 Inflammasome and Mitigates Alzheimer's-Like Pathology via Nrf2-TXNIP-TrX Axis.

Wang CY ，Xu Y ，Wang X ，Guo C ，Wang T ，Wang ZY ... -  《-》

Umbelliferone ameliorates cerebral ischemia-reperfusion injury via upregulating the PPAR gamma expression and suppressing TXNIP/NLRP3 inflammasome.

Umbelliferone (UMB), a natural antioxidant belonging to coumarin derivatives, is able to cross the blood-brain barrier and protect neuronal cells from death. Here we aimed to investigate the effects of UMB in a rat model of focal cerebral ischemia induced by middle cerebral artery occlusion/reperfusion (MCAO/R). Pretreatment with UMB (15 and 30 mg/kg) for 7 consecutive days ameliorated the neurological outcomes, infarct volume and brain edema in brains of MCAO rats. Our results provided evidence that UMB significantly protected neuronal cells against cerebral ischemia reperfusion-induced injury. Furthermore, UMB treatment could inhibited the level of oxidative stress and the production of inflammatory cytokines in brain tissues of MCAO rats. In addition, UMB significantly upregulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ), which exhibited neuroprotective effects in neurodegenerative disease. UMB treatment also suppressed NLRP3 inflammasome activation via reducing expression of Thiredoxin-interactive protein (TXNIP). These results suggest that UMB may have beneficial effects for neuroprotection against focal cerebral ischemic partly through the inhibition of TXNIP/NLRP3 inflammasome and activation of PPAR-γ.

Wang X ，Li R ，Wang X ，Fu Q ，Ma S ... -  《-》

CORM-2 inhibits TXNIP/NLRP3 inflammasome pathway in LPS-induced acute lung injury.

Jiang L ，Fei D ，Gong R ，Yang W ，Yu W ，Pan S ，Zhao M ，Zhao M ... -  《-》