Storax Protected Primary Cortical Neurons from Oxygen-Glucose Deprivation/Reoxygenation Injury via Inhibiting the TLR4/TRAF6/NF-κB Signaling Pathway

A novel p55PIK signaling peptide inhibitor alleviates neuroinflammation via the STAT3/NF-kB signaling pathway in experimental stroke

BACKGROUND

Ischemic stroke remains the predominant contributor to mortality and disability globally. Microglia undergo rapid activation and initiate inflammatory cascade reactions by phenotypic polarization, participating in the regulation of inflammatory injury and tissue repair post-ischemic stroke. Regulating microglia-mediated neuroinflammation is a promising therapeutic strategy for ischemic stroke. Previously, we designed and synthesized a novel p55PIK inhibitor, TAT-N15 polypeptide, which presents inhibitive activity on NF-κB signaling-mediated inflammation in acute conjunctivitis and allergic rhinitis. The present study aimed to explore the therapeutic effect and mechanism of TAT-N15 on ischemia stroke.

METHODS

The mouse model of transient cerebral ischemia was made using the intraluminal filament method. After being treated with daily intraperitoneal injections of TAT-N15 (10 mg/kg) for 7 d, the neurological outcomes and the cerebral infarction volume were evaluated. Histopathology of the ischemia cerebral hemisphere was observed by H&E and Nissl staining. Neuronal survival, astrogliosis, and co-labeling of CD86/Iba1 and CD206/Iba1 were detected by immunofluorescence. The cell apoptosis was estimated by TUNEL staining. The expression levels of apoptosis-associated proteins, proinflammatory cytokines, protein markers of M1 and M2 microglia, and the phosphorylation of NF-κB and STAT3 proteins in the ischemic penumbra were detected by Western blot.

RESULTS

TAT-N15 treatment significantly decreased the infarct volume and alleviated neurological functional impairment, neuronal injury, and neuron apoptosis. Meanwhile, TAT-N15 treatment restrained the activation of microglia and astrocytes as well as the protein expression of proinflammatory cytokine in ischemic penumbra. Additionally, the administration of TAT-N15 treatment resulted in a significant reduction in the density of M1 phenotype microglia while concurrently increasing the density of M2 phenotype microglia within the ischemic penumbra. Finally, mechanical analysis unveiled that TAT-N15 exerted a substantial inhibitory effect on the protein expression of phosphorylated STAT3 and NF-κB.

CONCLUSION

TAT-N15 may inhibit neuroinflammation via regulating microglia activation and polarization through the STAT3/NF-κB pathway, which exhibits the neuroprotection effect in ischemic stroke.

Protective effect and mechanism of styrax on ischemic stroke rats: metabonomic insights by UPLC-Q/TOF-MS analysis

CONTEXT

Styrax is used for prevention and treatment of cerebrovascular diseases. However, the underlying mechanism remains unclear.

OBJECTIVE

To elucidate styrax's anti-ischemic stroke protective effects and underlying mechanisms.

MATERIALS AND METHODS

An ischemic-stroke rat model was established based on middle cerebral artery occlusion (MCAO). Sprague-Dawley rats were randomly assigned to the following groups (n = 10) and administered intragastrically once a day for 7 consecutive days: sham, model, nimodipine (24 mg/kg), styrax-L (0.1 g/kg), styrax-M (0.2 g/kg) and styrax-H (0.4 g/kg). Neurological function, biochemical assessment, and ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS)-based serum metabonomics were used to elucidate styrax's cerebral protective effects and mechanisms. Pearson correlation and western blot analyses were performed to verify.

RESULTS

The addition of 0.4 g/kg styrax significantly reduced cerebral infarct volume and neurobehavioral abnormality score. Different doses of styrax also decrease MDA, TNF-α, IL-6, and IL-1β, and increase SOD and GSH-Px in ischemic-stroke rats (p < 0.05; MDA, p < 0.05 only at 0.4 g/kg dose). Biochemical indicators and metabolic-profile analyses (PCA, PLS-DA, and OPLS-DA) also supported styrax's protective effects. Endogenous metabolites (22) were identified in ischemic-stroke rats, and these perturbations were reversible via styrax intervention, which is predominantly involved in energy metabolism, glutathione and glutamine metabolism, and other metabolic processes. Additionally, styrax significantly upregulated phosphorylated AMP-activated protein kinase and glutaminase brain-tissue expression.

CONCLUSION

Styrax treatment could ameliorate ischemic-stroke rats by intervening with energy metabolism and glutamine metabolism. This can help us understand the mechanism of styrax, inspiring more clinical application and promotion.

New insights into the characteristics of DRAK2 and its role in apoptosis: From molecular mechanisms to clinically applied potential

As a member of the death-associated protein kinase (DAPK) family, DAP kinase-associated apoptosis-inducing kinase 2 (DRAK2) performs apoptosis-related functions. Compelling evidence suggests that DRAK2 is involved in regulating the activation of T lymphocytes as well as pancreatic β-cell apoptosis in type I diabetes. In addition, DRAK2 has been shown to be involved in the development of related tumor and non-tumor diseases through a variety of mechanisms, including exacerbation of alcoholic fatty liver disease (NAFLD) through SRSF6-associated RNA selective splicing mechanism, regulation of chronic lymphocytic leukemia and acute myeloid leukemia, and progression of colorectal cancer. This review focuses on the structure, function, and upstream pathways of DRAK2 and discusses the potential and challenges associated with the clinical application of DRAK2-based small-molecule inhibitors, with the aim of advancing DRAK2 research.