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Background: Hypoxia inducible factor-1α (HIF-1α) is a sensitive indicator of oxygen homeostasis, of which the expression elevates following hypoxia/ischemia. This study reveals the specific mechanisms underlying the effects of HIF-1α on ischemic stroke (IS)., Methods: IS model was established using middle cerebral artery occlusion (MCAO)-modeled male rats and oxygen glucose deprivation/reoxygenation (OGD/R)-treated mice hippocampal cells HT22, followed by the silencing of HIF-1α and the overexpression of C-X-C motif chemokine receptor 4 (CXCR4) and nuclear factor-kappa B (NF-κB). Following the surgery, Garcia's grading scale was applied for neurological evaluation. Cerebral infarcts and injuries were visualized using 2,3,5-triphenyltetrazolium chloride and hematoxylin-eosin staining. The levels of tumor necrosis factor-α, Interleukin (IL)-6, IL-1β, malondialdehyde, and 8-hydroxy-2'-deoxyguanosine, were calculated via ELISA. MTT assay and lactate dehydrogenase (LDH) assay kit were adopted to determine the viability and cytotoxicity of OGD/R-modeled cells. Reactive oxygen species (ROS) generation was evaluated using a 2'-7'dichlorofluorescin diacetate (DCFH-DA) probe. The levels of HIF-1α, CXCR4, and NF-κB p65 were quantified via Western blot and immunofluorescence, respectively., Results: HIF-1α knockdown improved Garcia's score, attenuated the cerebral infarct, inflammation, and ROS generation, and alleviated the levels of inflammatory cytokines and CXCR4/NF-κB p65 in MCAO-modeled rats. Such effects were reversed following the overexpression of CXCR4 and NF-κB. Also, in OGD/R-treated HT22 cells, HIF-1α silencing diminished the cytotoxicity and ROS production and reduced the expressions of CXCR4/NF-κB p65, while promoting viability. However, CXCR4/NF-κB p65 overexpression did the opposite., Conclusion: HIF-1α knockdown alleviates inflammation and oxidative stress in IS through the CXCR4/NF-κB pathway., (© 2024 The Author(s). Brain and Behavior published by Wiley Periodicals LLC.)

Triptolide (TP), the main active compound extracted from medicine- tripterygium wilfordii Hook f. (TWHF). It has anti-tumor and immunomodulatory properties. Our study aimed to investigate the mechanisms of hepatotoxicity treated with TP in vivo and in vitro, as well as their relationship with the NF-κB (p65) signal pathway; and to assess TP-induced hepatotoxicity after CYP2E1 modulation by the known inhibitor, clomethiazole, and the known inducer, pyrazole. Mice were given TP to cause liver injury and IHHA-1 cells were given TP to cause hepatocyte injury. The enzyme activity and hepatotoxicity changed dramatically when the CYP2E1 inhibitor and inducer were added. In comparison to the control group, the enzyme inducer increased the activity of CYP2E1, whereas the enzyme inhibitor had the opposite effect. Our findings suggest that TP is an inducer of CYP2E1 via a time-dependent activation mechanism. In addition, TP can promote oxidative stress, inflammatory and involving the NF-κB (p65) signal pathway. Therefore, we used triptolide to stimulate C57 mice and IHHA-1 cells to determine whether TP can promote oxidative stress and inflammation by activating CYP2E1 in response to exacerbated liver damage and participate in NF-κB (p65) signaling pathway.

We used a sensitive and accurate method based on isotope dilution high-performance liquid chromatography–triple quadrupole mass spectrometry (ID-LC-MS/MS) to determine the levels of 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxo-dGsn) and 8-oxo-7,8-dihydroguanosin (8-oxo-Gsn) in various tissue specimens, plasma, and urine of hyperglycemic Sprague Dawley rats induced by streptozotocin (STZ). The oxidative DNA and RNA damages were observed in various organs and the amounts of 8-oxo-dGsn and 8-oxo-Gsn derived from DNA and RNA were increased with hyperglycemic status. In contrast to the results of the nucleic acid samples derived from tissues, the levels of 8-oxo-Gsn in urine and plasma were significantly higher compared with that of 8-oxo-dGsn, which most likely reflected the RNA damage that occurs more frequently compared with DNA damage. For the oxidative stress induced by hyperglycemia, 8-oxo-Gsn in urine may be a sensitive biomarker on the basis of the results in urine, plasma, and tissues. In addition, high levels of urinary 8-oxo-Gsn were observed before diabetic microvascular complications. Based on that the 8-oxo-dGsn was associated with diabetic nephropathy and RNA was more vulnerable to oxidative stress compared with DNA. We also propose that 8-oxo-Gsn is correlated with diabetic nephropathy and that 8-oxo-Gsn in urine could be a useful and sensitive marker of diabetic nephropathy. [ABSTRACT FROM AUTHOR]