Thioredoxin-Interacting Protein: a Novel Target for Neuroprotection in Experimental Thromboembolic Stroke in Mice

Abstract

Redox imbalance in the brain significantly contributes to ischemic stroke pathogenesis but antioxidant therapies have failed in clinical trials. Activation of endogenous defense mechanisms may provide better protection against stroke-induced oxidative injury. TXNIP (thioredoxin-interacting protein) is an endogenous inhibitor of thioredoxin (TRX), a key antioxidant system. We hypothesize that TXNIP inhibition attenuates redox imbalance and inflammation and provide protection against a clinically relevant model of embolic stroke. Male TXNIP-knockout (TKO), wild-type (WT) and WT mice treated with a pharmacological inhibitor of TXNIP, resveratrol (RES; 5mg/kg body weight) were subjected to embolic middle cerebral artery occlusion (eMCAO). Behavior outcomes were monitored using neurological deficits score and grip strength meter at 24 h after eMCAO. Expression of oxidative, inflammatory and apoptotic markers were analyzed by Western blot, immunohistochemistry and slot blot at 24h post-eMCAO. Our result showed that ischemic injury increases TXNIP in WT mice and that RES inhibits TXNIP expression and protects brain against ischemic damage. TKO and RES-treated mice exhibited 39.26% and 41.11% decrease in infarct size and improved neurological score and grip strength compared to WT mice after eMCAO. Furthermore, the levels of TRX, nitrotyrosine, NOD-like receptor protein (NLRP3), interleukin-1β (IL-1β), tumor necrosis factor- α (TNF-α), and activations of caspase-1, caspase-3 and poly ADP ribose polymerase (PARP) were significantly (P<0.05) attenuated in TKO and RES-treated mice. The present study suggests that TXNIP is contributing to acute ischemic stroke through redox-imbalance and inflammasome activation, and inhibition of TXNIP may provide a new target for therapeutic interventions. This study also affirms the importance of the antioxidant effect of RES on the TRX/TXNIP system.

Thioredoxin‐Interacting Protein Mediates NLRP3 Inflammasome Activation Involved in the Susceptibility to Ischemic Acute Kidney Injury in Diabetes

“…Several studies have demonstrated that RES exerts protective effects against I/R injury in the kidneys [31], as well as the liver and brain injury by reducing oxidative stress and due to inhibition of TXNIP expression [32, 33]. In the present study, we found that TXNIP protein expression was significantly reduced after siRNA transfection in cultured HK-2 cells.…”

“…RES treatment can ameliorate hyperglycemia-mediated renal dysfunction or DN [30]. Several studies have demonstrated that RES exerts protective effects against I/R injury in the kidneys [31], as well as the liver and brain ischemia injury by reducing oxidative stress and downregulating TXNIP expression [32, 33]. …”

Serum Levels of Thioredoxin Are Associated with Stroke Risk, Severity, and Lesion Volumes

“…Recent studies show that TRX possesses a neuronal protective effect and that TRX inactivation is closely related to cerebral ischemia injury [40]. Similarly, one study suggested that TXNIP (an endogenous inhibitor of thioredoxin) is contributing to acute ischemic stroke through redox imbalance and inflammasome activation, and inhibition of TXNIP may provide a new target for therapeutic interventions [41]. From above studies, we could surmise that TRX possessed a neuronal protective effect at baseline.…”

Role of interleukin-10 in the neuroprotective effect of the Angiotensin Type 2 Receptor agonist, compound 21, after ischemia/reperfusion injury

“…Protein was quantified using Pierce BCA protein assay kit (Thermo Scientific), and 50 μg protein aliquots were run on SDS-PAGE as described previously (Guan et al, 2011), transferred to nitrocellulose membranes and probed with mouse anti-TNF-α (Abcam) and rabbit anti-cleaved caspase 3 (Cell Signaling) antibodies (Ishrat et al, 2015). Rabbit anti-GAPDH (Cell Signaling) and mouse anti-β-actin (Sigma) were used as loading controls depending on the molecular weight and species of the probed proteins.…”