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Mitochondrial dysfunction and oxidative stress are important mechanisms for secondary injury after traumatic brain injury (TBI), which result in progressive pathophysiological exacerbation. Although the Fibronectin type III domain-containing 5 (FNDC5) was reported to repress oxidative stress by retaining mitochondrial biogenesis and dynamics, its possible role in the secondary injury after TBI remain obscure. In present study, we observed that the level of serum irisin (the cleavage product of FNDC5) significantly correlated with the neurological outcomes of TBI patients. Knockout of FNDC5 increased the lesion volume and exacerbated apoptosis and neurological deficits after TBI in mice, while FNDC5 overexpression yielded a neuroprotective effect. Moreover, FNDC5 deficiency disrupted mitochondrial dynamics and function. Activation of Sirtuin 3 (SIRT3) alleviated FNDC5 deficiency-induced disruption of mitochondrial dynamics and bioenergetics. In neuron-specific SIRT3 knockout mice, FNDC5 failed to attenuate TBI-induced mitochondrial damage and brain injuries. Mechanically, FNDC5 deficiency led to reduced SIRT3 expression via enhanced ubiquitin degradation of transcription factor Nuclear factor erythroid 2-related factor 2 (NRF2), which contributed to the hyperacetylation and inactivation of key regulatory proteins of mitochondrial dynamics and function, including OPA1 and SOD2. Finally, engineered RVG29-conjugated nanoparticles were generated to selectively and efficiently deliver irisin to the brain of mice, which yielded a satisfactory curative effect against TBI. In conclusion, FNDC5/irisin exerts a protective role against acute brain injury by promoting SIRT3-dependent mitochondrial quality control and thus represents a potential target for neuroprotection after TBI., (© 2024. The Author(s).)

[Display omitted] • sPlas significantly reduced cerebral ischemic infarction in mice at 5 d after tMCAO. • sPlas significantly alleviated neural oxidative stress in mice at 5 d after tMCAO. • sPlas significantly regulated neural inflammation in mice at 5 d after tMCAO. • sPlas significantly attenuated neurovascular unit damage in mice at 5 d after tMCAO. • sPlas may be a preventive and therapeutic candidate against ischemic stroke. Scallop-derived plasmalogen (sPlas) has both anti-oxidative and anti-inflammation activities, but its efficacy has not been investigated in ischemic stroke models where oxidative stress, inflammation, and neurovascular unit (NVU) damage accelerates pathophysiological progression. Therefore, in the present study, we aimed to assess the neuroprotective effects of sPlas in ischemic stroke by using a transient middle cerebral artery occlusion (tMCAO) mouse model. After the pretreatment of vehicle or sPlas (10 mg/kg/day) for 14 days, adult male mice were subjected to tMCAO for 60 min, then continuously treated with vehicle or sPlas during reperfusion and for an additional 5 days. The administration of sPlas significantly improved motor deficits (corner and rotarod tests, * p < 0.05 vs vehicle), enhanced serum antioxidative activity (OXY-adsorbent and d-ROMs tests, * p < 0.05 vs vehicle), reduced infarction volume (* p < 0.05 vs vehicle), decreased the expression of two oxidative stress markers, 4-HNE (* p < 0.05 vs vehicle) and 8-OHdG (* p < 0.05 vs vehicle), decreased the expression of pro-inflammatory markers Iba-1 (** p < 0.01 vs vehicle), IL-1β (** p < 0.01 vs vehicle), and TNF-α (** p < 0.01 vs vehicle), and alleviated NVU damage (collagen IV, MMP9, and GFAP/collagen IV, * p < 0.05 vs vehicle). Our present findings are the first to demonstrate the neuroprotective effects of sPlas on acute ischemic stroke mice at 5 d after tMCAO via anti-oxidative stress, anti-inflammation, and improvement of NVU damage, suggesting the potential of sPlas in preventing and treating ischemic stroke. [ABSTRACT FROM AUTHOR]

Carnosine (β-alanyl-L-histidine) is a natural dipeptide with multiple neuroprotective properties. Previous studies have advertised that carnosine scavenges free radicals and displays anti-inflammatory activity. However, the underlying mechanism and the efficacies of its pleiotropic effect on prevention remained obscure. In this study, we aimed to investigate the anti-oxidative, anti-inflammative, and anti-pyroptotic effects of carnosine in the transient middle cerebral artery occlusion (tMCAO) mouse model. After a daily pre-treatment of saline or carnosine (1000 mg / kg / day) for 14 days, mice (n = 24) were subjected to tMCAO for 60 min and continuously treated with saline or carnosine for additional 1 and 5 days after reperfusion. The administration of carnosine significantly decreased infarct volume 5 days after the tMCAO (* p < 0.05) and effectively suppressed the expression of 4-HNE, 8-OHdG, Nitrotyrosine 5 days, and RAGE 5 days after tMCAO. Moreover, the expression of IL-1 β was also significantly suppressed 5 days after tMCAO. Our present findings demonstrated that carnosine effectively relieves oxidative stress caused by ischemic stroke and significantly attenuates neuroinflammatory responses related to IL-1 β , suggesting that carnosine can be a promising therapeutic strategy for ischemic stroke. [Display omitted] • Carnosine significantly reduced infarct volume 5 days after tMCAO. • Carnosine significantly alleviated neural oxidative stress 1 and 5 days after tMCAO. • Carnosine significantly regulated inflammation marker expression 5 days after tMCAO. [ABSTRACT FROM AUTHOR]