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 ... -  《-》

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 ... -  《-》

Α‑lipoic acid protects against cerebral ischemia/reperfusion-induced injury in rats.

Deng H ，Zuo X ，Zhang J ，Liu X ，Liu L ，Xu Q ，Wu Z ，Ji A ... -  《-》

Ruscogenin Attenuates Cerebral Ischemia-Induced Blood-Brain Barrier Dysfunction by Suppressing TXNIP/NLRP3 Inflammasome Activation and the MAPK Pathway.

Cao G ，Jiang N ，Hu Y ，Zhang Y ，Wang G ，Yin M ，Ma X ，Zhou K ，Qi J ，Yu B ，Kou J ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

Sulforaphane improves outcomes and slows cerebral ischemic/reperfusion injury via inhibition of NLRP3 inflammasome activation in rats.

Ischemia/reperfusion (I/R) injury has been correlated with systemic inflammatory response. In addition, NLRP3 has been suggested as a cause in many inflammatory processes. Sulforaphane (SFN) is a naturally occurring isothiocyanate found in cruciferous vegetables, such as broccoli and cabbage. While recent studies have demonstrated that Sulforaphane has protective effects against cerebral ischemia/reperfusion injury, little is known about how those protective effects work. In this study, we focus our investigation on the role and process of Sulforaphane in the inhibition of NLRP3 inflammasome activation, as well as its effect on brain ischemia/reperfusion injury. Adult male Sprague-Dawley rats were injected with Sulforaphane (5 or 10mg/kg) intraperitoneally at the beginning of reperfusion, after a 60min period of occlusion. A neurological score and infarct volume were assessed at 24h after the administration of Sulforaphane. Myeloperoxidase (MPO) activity was measured at 24h to assess neutrophil infiltration in brain tissue. ELISA, RT-PCR and Western blot analyses were used to measure any inflammatory reaction. Sulforaphane treatment significantly reduced infarct volume and improved neurological scores when compared to a vehicle-treated group. Neutrophil infiltration was significantly higher in the vehicle-treated group than in the Sulforaphane treatment group. Sulforaphane treatment inhibits NLRP3 inflammasome activation and the downregulation of cleaved caspase-1, while reducing IL-1β and IL-18 expression. The inhibition of inflammatory response with Sulforaphane treatment improves outcomes after focal cerebral ischemia. This neuroprotective effect is likely exerted by Sulforaphane inhibited NLRP3 inflammasome activation caused by the downregulation of NLRP3, the induction of cleaved caspase-1, and thus the reduction of IL-1β and IL-18.

Yu C ，He Q ，Zheng J ，Li LY ，Hou YH ，Song FZ ... -  《-》