Knockdown of NADPH oxidase 4 reduces mitochondrial oxidative stress and neuronal pyroptosis following intracerebral hemorrhage.

Intracerebral hemorrhage is often accompanied by oxidative stress induced by reactive oxygen species, which causes abnormal mitochondrial function and secondary reactive oxygen species generation. This creates a vicious cycle leading to reactive oxygen species accumulation, resulting in progression of the pathological process. Therefore, breaking the cycle to inhibit reactive oxygen species accumulation is critical for reducing neuronal death after intracerebral hemorrhage. Our previous study found that increased expression of nicotinamide adenine dinucleotide phosphate oxidase 4 (NADPH oxidase 4, NOX4) led to neuronal apoptosis and damage to the blood-brain barrier after intracerebral hemorrhage. The purpose of this study was to investigate the role of NOX4 in the circle involving the neuronal tolerance to oxidative stress, mitochondrial reactive oxygen species and modes of neuronal death other than apoptosis after intracerebral hemorrhage. We found that NOX4 knockdown by adeno-associated virus (AAV-NOX4) in rats enhanced neuronal tolerance to oxidative stress, enabling them to better resist the oxidative stress caused by intracerebral hemorrhage. Knockdown of NOX4 also reduced the production of reactive oxygen species in the mitochondria, relieved mitochondrial damage, prevented secondary reactive oxygen species accumulation, reduced neuronal pyroptosis and contributed to relieving secondary brain injury after intracerebral hemorrhage in rats. Finally, we used a mitochondria-targeted superoxide dismutase mimetic to explore the relationship between reactive oxygen species and NOX4. The mitochondria-targeted superoxide dismutase mimetic inhibited the expression of NOX4 and neuronal pyroptosis, which is similar to the effect of AAV-NOX4. This indicates that NOX4 is likely to be an important target for inhibiting mitochondrial reactive oxygen species production, and NOX4 inhibitors can be used to alleviate oxidative stress response induced by intracerebral hemorrhage.

Paeoniflorin elicits the anti-proliferative effects on glioma cell via targeting translocator protein 18 KDa.

As a natural compound isolated from Paeoniae radix, Paeoniflorin (PF) has been shown the antitumor effects in various types of human cancers including glioma, which is one of the serious tumors in central nervous system. Translocator protein 18 KDa (TSPO) has been shown to be relevant to the glioma aetiology. However, the regulation of PF in TSPO and neurosteriods biosynthesis on glioma is still unclear. In the present study, the glioma cell (U87 and U251) were cultured and used to quantify the bindings of PF on TSPO. Results indicated that there was not significant different between IC50 of PF and TSPO ligand PK11195. Moreover, PF exerted the anti-proliferative effects in glioma cell with a dose dependent inhibition from 12.5 to 100 µM in vitro. Consistent with the effects of PK11195, lowered levels on progesterone, allopregnanolone, as well as TSPO mRNA were induced by PF (25 and 50 µM). Furthermore, a xenograft mouse model with U87 cell-derived was significant inhibited by PF treatment, as well as the PK11195 administration. These results demonstrate that PF exerts its antitumor effects associated with the TSPO and neurosteroids biosynthesis in glioma cells could be a promising therapeutic agent for glioma therapy.

The anxiolytic-like effects of ginsenoside Rg2 on an animal model of PTSD.

Post traumatic stress disorder (PTSD) is one of the mental illness. The antidepressant-like properties of ginsenoside Rg2 (GRg2) have been shown, while little is known about its anti-PTSD-like effects. In the present study, the PTSD-associated behavioral deficits in rats were induced following exposure to single prolonged stress (SPS). The results showed that the decreased time and entries in the open arms in elevated plus maze test (EPMT) and increased freezing duration in contextual fear paradigm (CFP) were reversed by GRg2 (10 and 20 mg/kg) without affecting the locomotor activity. In addition, GRg2 (10 and 20 mg/kg) could block the decreased levels of progesterone, allopregnanolone, serotonin (5-HT), 5-Hydroxyindoleacetic acid (5-HIAA), corticotropin releasing hormone (CRH), corticosterone (Cort) and adrenocorticotropic hormone (ACTH) in the brain or serum. In summary, GRg2 alleviated the PTSD-associated behavioral deficits with biosynthesis of neurosteroids, normalization of serotonergic system and HPA axis dysfunction.

The anxiolytic-like effects of estazolam on a PTSD animal model.

Post-traumatic stress disorder (PTSD) is a serious psychiatric disorder. Estazolam has been shown to produce anxiolytic-, hypnotic-, amnestic-, and sedative-like effects. However, few studies are concerned about its anti-PTSD-like effects. The anti-PTSD-like effects of estazolam were evaluated by single prolonged stress animal model. After exposure to single prolonged stress, rats (Sprague-Dawley, male, 8 weeks) were administered by estazolam (0.5, 1 and 2 mg/kg, i.p.) from day 2 to 13 once daily. The behavioral assessments were performed during treatment with drugs. After the behavioral evaluation, the role of allopregnanolone in the anti-PTSD-like effects of estazolam was also evaluated via astrocyte cells and brain tissues (e.g. prefrontal cortex, hippocampus, and amygdala). The PTSD-like behavioral deficits were significantly blocked by estazolam (1 and 2 mg/kg, i.p.) without affecting locomotor activity. Consistently, the levels on allopregnanolone were increased by estazolam (1 and 2 mg/kg, i.p.) in prefrontal cortex, hippocampus, and amygdala. The levels of allopregnanolone were increased by sertraline (1 µmoL/L) and estazolam (4 µmoL/L), while the effects were antagonized by trilostane (1 µmoL/L) and finasteride (1 µmoL/L) in astrocyte cells, respectively. Collectively, the anxiety-like behavior deficits were ameliorated by estazolam in the single prolonged stress animal model that was associated with biosynthesis of allopregnanolone.

The inulin-type oligosaccharides extract from morinda officinalis, a traditional Chinese herb, ameliorated behavioral deficits in an animal model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a severe psychiatric condition. The allopregnanolone biosynthesis has been implicated as one of the possible contributors to PTSD. Inulin-type oligosaccharides of morinda officinalis (IOMO) had been shown to be effective in the therapy of depression. However, few studies concern the anti-PTSD-like effects of IOMO. To evaluate this, the single prolonged stress (SPS) model was used in the present study. It had been shown that the behavioral deficits of SPS-treated rats were reversed by IOMO (25.0 and 50.0 mg/kg, i.p.), which reversed the increased freezing time in contextual fear paradigm (CFP) and the decreased time and entries in open arms in the elevated plus maze (EPM) test without affecting the locomotor activity in the open field (OF) test. In addition, the decreased allopregnanolone in the prefrontal cortex, hippocampus, and amygdala was reversed by IOMO (25.0 and 50.0 mg/kg, i.p.), respectively. In summary, the present study indicated that the IOMO exert anti-PTSD-like behaviors, which maybe associated with the brain allopregnanolone biosynthesis.

The effects of PK11195 on meningioma was associated with allopregnanolone biosynthesis, which was mediated by translocator protein 18 KDa.

Meningioma is one of the common brain tumors in adults. It had been shown that the allopregnanolone biosynthesis was associated with tumorigenesis and PK11195, the translocator protein 18 KDa (TSPO) antagonist, had the effects of the allopregnanolone biosynthesis. However, little is known about the association between the effects of PK11195 on meningioma and the allopregnanolone biosynthesis. To evaluate this, the meningioma cell line IOMM-LEE was applied. Cell viability and proliferation were determined by CCK-8 assay. The IC50 of PK11195 on the IOMM-LEE was 1.505 ± 0.08 nM. The cell viability and proliferation of AC-5216 (TSPO selective ligand, 2 and 4 nM) was blocked by PK11195 (1.5 nM). Further, we evaluated the role of allopregnanolone biosynthesis in the effects of TSPO on meningioma. Enzyme-Linked ImmunoSorbent Assay (ELISA) was used in the measurement of the allopregnanolone level. It showed that the allopregnanolone level was increased by AC-5216 (2 and 4 nM) and the increase was reversed by PK11195 (1.5 nM). Collectedly, it firstly indicated that the effects of PK11195 on meningioma were relevant to the decrease of allopregnanolone biosynthesis, which was mediated by TSPO.