Mild hypothermia alleviates oxygen−glucose deprivation/reperfusion-induced apoptosis by inhibiting ROS generation, improving mitochondrial dysfunction and regulating DNA damage repair pathway in PC12 cells

Hypothermia protects the integrity of corticospinal tracts and alleviates mitochondria injury after intracerebral hemorrhage in mice

Disruption of corticospinal tracts (CST) is a leading factor for motor impairments following intracerebral hemorrhage (ICH) in the striatum. Previous studies have shown that therapeutic hypothermia (HT) improves outcomes of ICH patients. However, whether HT has a direct protection effect on the CST integrity and the underlying mechanisms remain largely unknown. In this study, we employed a chemogenetics approach to selectively activate bilateral warm-sensitive neurons in the preoptic areas to induce a hypothermia-like state. We then assessed effects of HT treatment on the integrity of CST and motor functional recovery after ICH. Our results showed that HT treatment significantly alleviated axonal degeneration around the hematoma and the CST axons at remote midbrain region, ultimately promoted skilled motor function recovery. Anterograde and retrograde tracing revealed that HT treatment protected the integrity of the CST over an extended period. Mechanistically, HT treatment prevented mitochondrial swelling in degenerated axons around the hematoma, alleviated mitochondrial impairment by reducing mitochondrial ROS accumulation and improving mitochondrial membrane potential in primarily cultured cortical neurons with oxyhemoglobin treatment. Serving as a proof of principle, our study provided novel insights into the application of HT to improve functional recovery after ICH.

Urolithin B Attenuates Cerebral Ischemia-reperfusion Injury by Modulating Nrf2-regulated Anti-oxidation in Rats

Ischemia-reperfusion (IR) induces a wide range of irreversible injuries. Cerebral IR injury (IRI) refers to additional brain tissue damage that occurs after blood flow is restored following cerebral ischemia. Currently, no established methods exist for treating IRI. Oxidative stress is recognized as a primary mechanism initiating IRI and a crucial focal target for its treatment. Urolithin B, a metabolite derived from ellagitannins, antioxidant polyphenols, has demonstrated protective effects against oxidative stress in various disease conditions. However, the precise mechanism underlying UB's effect on IRI remains unclear. In our current investigation, we assessed UB's ability to mitigate neurological functional impairment induced by IR using a neurological deficit score. Additionally, we examined cerebral infarction following UB administration through TTC staining and neuron Nissl staining. UB's inhibition of neuronal apoptosis was demonstrated through the TUNEL assay and Caspase-3 measurement. Additionally, we examined UB's effect on oxidative stress levels by analyzing malondialdehyde (MDA) concentration, superoxide dismutase (SOD) activity, and immunohistochemistry analysis of inducible nitric oxide synthase (iNOS) and 8-hydroxyl-2'-deoxyguanosine (8-OHdG). Notably, UB demonstrated a reduction in oxidative stress levels. Mechanistically, UB was found to stimulate the Nrf2/HO-1 signaling pathway, as evidenced by the significant reduction in UB's neuroprotective effects upon administration of ATRA, an Nrf2 inhibitor. In summary, UB effectively inhibits oxidative stress induced by IR through the activation of the Nrf2/HO-1 signaling pathway. These findings suggest that UB holds promise as a therapeutic agent for the treatment of IRI.

IR-820@NBs Combined with MG-132 Enhances the Anti-Hepatocellular Carcinoma Effect of Sonodynamic Therapy

Purpose

Sonodynamic therapy (SDT) is a promising and significant measure for the treatment of tumors. However, the internal situation of hepatocellular carcinoma (HCC) is complex, separate SDT treatment is difficult to play a good therapeutic effect. Here, we used SDT combined with MG-132 to mediate apoptosis and autophagy of HCC cells to achieve the purpose of treatment of cancer.

Methods

To determine the generated reactive oxygen species (ROS) and the change of mitochondrial membrane potential (ΔΨm), HepG2 cells were stained by 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) and 5,5',6,6'-Tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide (JC-1) staining to determine the IR-820@NBs-mediated SDT to achieve HCC therapy through the mitochondrial pathway. Cell counting kit 8 (CCK-8) assay and flow cytometry were used to detect cell viability and apoptosis rate of HepG2 cells. Autophagy was detected by mCherry-GFP-LC3B fluorescence labeling. Chloroquine (Cq) pretreatment was used to explore the relationship between autophagy and apoptosis. To detect the ability of HepG2 cells migration and invasion, cell scratch assay and transwell assay were used.

Results

The successfully prepared IR-820@NBs could effectively overcome the shortcomings of IR-820 and induce lethal levels of ROS by ultrasound irradiation. As a dual agonist of apoptosis and autophagy, MG-132 could effectively enhance the efficacy of SDT in the process of treating HCC. After pre-treatment with Cq, the cell activity increased and the level of apoptosis decreased, which proved that apoptosis and autophagy were induced by combined therapy, autophagy, and apoptosis have the synergistic anti-tumor effect, and part of apoptosis was autophagy-dependent. After combined therapy, the activity and invasive ability of HCC cells decreased significantly.

Conclusion

SDT combined with MG-132 in the process of treating liver cancer could effectively induce apoptosis and autophagy anti-tumor therapy, which is helpful to the research of new methods to treat liver cancer.