Nur77-IRF1 axis inhibits esophageal squamous cell carcinoma growth and improves anti-PD-1 treatment efficacy.

The nuclear receptor Nur77 plays paradoxical roles in numerous cancers. However, whether Nur77 inhibits esophageal squamous cell carcinoma (ESCC) growth and affects immunological responses against ESCC has not been determined. The functional role of Nur77 in ESCC was investigated in this study using human ESCC cell lines, quantitative real-time polymerase chain reaction (PCR), cell proliferation and colony formation assays, flow cytometry analysis, western blotting and animal models. The target gene controlled by Nur77 was verified using dual-luciferase reporter assays, chromatin immunoprecipitation analysis and functional rescue experiments. To examine the clinical importance of Nur77, 72 human primary ESCC tissues were subjected to immunohistochemistry. Taken together, these findings showed that, both in vitro and in vivo, Nur77 dramatically reduced ESCC cell growth and triggered apoptosis. Nur77 directly interacts with the interferon regulatory factor 1 (IRF1) promoter to inhibit its activity in ESCC. Pharmacological induction of Nur77 using cytosporone B (CsnB) inhibited ESCC cell proliferation and promoted apoptosis both in vitro and in vivo. Furthermore, CsnB increased CD8+ T-cell infiltration and cytotoxicity to inhibit the formation of ESCC tumors in an immunocompetent mouse model. In ESCC tissues, Nur77 expression was downregulated, and IRF1 expression was increased; moreover, their expression levels were negatively related. IRF1 and Nur77 were strongly correlated with overall survival. These findings suggested that Nur77 targets and regulates the IRF1/PD-L1 axis to serve as a tumor suppressor in ESCC. Graphical abstract of the regulatory mechanism of Nur77 overexpression downregulates IRF1 in the inhibition of ESCC progression and enhance anti-PD-1 therapy efficacy.

Inhibition of autophagy-related protein 7 enhances anti-tumor immune response and improves efficacy of immune checkpoint blockade in microsatellite instability colorectal cancer.

BACKGROUND: The efficacy of anti-PD-1 therapy is primarily hindered by the limited T-cell immune response rate and immune evasion capacity of tumor cells. Autophagy-related protein 7 (ATG7) plays an important role in autophagy and it has been linked to cancer. However, the role of ATG7 in the effect of immune checkpoint blockade (ICB) treatment on high microsatellite instability (MSI-H)/mismatch repair deficiency (dMMR) CRC is still poorly understood. METHODS: In this study, patients from the cancer genome altas (TCGA) COAD/READ cohorts were used to investigate the biological mechanism driving ATG7 development. Several assays were conducted including the colony formation, cell viability, qRT-PCR, western blot, immunofluorescence, flow cytometry, ELISA, immunohistochemistry staining and in vivo tumorigenicity tests. RESULTS: We found that ATG7 plays a crucial role in MSI-H CRC. Its knockdown decreased tumor growth and caused an infiltration of CD8+ T effector cells in vivo. ATG7 inhibition restored surface major histocompatibility complex I (MHC-I) levels, causing improved antigen presentation and anti-tumor T cell response by activating reactive oxygen species (ROS)/NF-κB pathway. Meanwhile, ATG7 inhibition also suppressed cholesterol accumulation and augmentation of anti-tumor immune responses. Combining ATG7 inhibition and statins improved the therapeutic benefit of anti-PD-1 in MSI-H CRC. Importantly, CRC patients with high expression of both ATG7 and recombinant 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) experienced worse prognosis compared to those with low ATG7 and HMGCR expression. CONCLUSIONS: Inhibition of ATG7 leads to upregulation of MHC-I expression, augments immune response and suppresses cholesterol accumulation. These findings demonstrate that ATG7 inhibition has therapeutic potential and application of statins can increase the sensitivity to immune checkpoint inhibitors.

CDK12 inhibition upregulates ATG7 triggering autophagy via AKT/FOXO3 pathway and enhances anti-PD-1 efficacy in colorectal cancer.

As the world's fourth most deadly cancer, colorectal cancer (CRC) still needed the novel therapeutic drugs and target urgently. Although cyclin-dependent kinase 12 (CDK12) has been shown to be implicated in the malignancy of several types of cancer, its functional role and mechanism in CRC remain largely unknown. Here, we found that suppression of CDK12 inhibited tumor growth in CRC by inducing apoptosis. And CDK12 inhibition triggered autophagy by upregulating autophagy related gene 7 (ATG7) expression. Inhibition of autophagy by ATG7 knockdown and chloroquine (CQ) further decreased cell viability induced by CDK12 inhibition. Further mechanism exploration showed that CDK12 interacted with protein kinase B (AKT) regulated autophagy via AKT/forkhead box O3 (AKT/FOXO3) pathway. FOXO3 transcriptionally upregulated ATG7 expression and autophagy when CDK12 inhibition in CRC. Level of CDK12 and p-FOXO3/FOXO3 ratio were correlated with survival in CRC patients. Moreover, CDK12 inhibition improved the efficacy of anti-programmed cell death 1(PD-1) therapy in CRC murine models by enhancing CD8 + T cells infiltration. Thus, our study founded that CDK12 inhibition upregulates ATG7 triggering autophagy via AKT/FOXO3 pathway and enhances anti-PD-1 efficacy in CRC. We revealed the roles of CDK12/FOXO3/ATG7 in regulating CRC progression, suggesting potential biomarkers and therapeutic target for CRC.

Clinical outcomes and medical resource utilization of toripalimab combination therapy versus bevacizumab plus chemotherapy in advanced non-squamous non-small cell lung cancer.

OBJECTIVE: This study aimed to evaluate the real-world clinical efficacy and safety, economic burdens and medical resource utilization (MRU) of toripalimab treatment patterns compared with bevacizumab plus chemotherapy (BCP) for patients with advanced non-squamous NSCLC in China. METHODS: Progression-free survival (PFS), adverse drug reactions (ADR) and the costs of drugs, laboratory testing, imageology examinations (including CT, B ultrasound, MRI), medical service, nursing, treatment, genetic test and medical disposable material were compared between two groups. A retrospective observational study was conducted with electronic medical records from Fudan University Huashan hospital. Data was obtained from established electronic medical records (EMRs) and patient surveys. Survival time from the study enrollment to disease progression or death plus from 1st progression disease (PD) in the maintenance phase to 2nd PD (PFS II), adverse events (AE), direct medical costs, MRU and AE-related costs were collected and compared between toripalimab group and BCP group. A total of 246 patients were enrolled. RESULTS: Toripalimab combination therapy has significantly prolonged PFS comparing with BCP (13.8 months vs. 6.2 months, p < .001). A statistically significant improvement in PFS was observed favoring all toripalimab regimen subgroups compared with the bevacizumab group. Patients in toripalimab group occupied more overall resource consumption, more direct medical costs ($47,056.9 vs. $29,951.0, p < .0001) and AE-related costs ($4,500.2 vs. $784.4, p < .0001) than BCP group. Although patients in the toripalimab group used more drugs to prevent AEs ($4,500.2 vs. $784.4, p < .0001), they still experienced more AEs than patients in BCP group (51.4% vs. 41.4%). CONCLUSION: Toripalimab combination therapy could significantly prolonged PFS for patients with advanced non-squamous NSCLC compared with BCP, but at the expense of more MRU, costs and AEs.

Carfilzomib suppressed LDHA-mediated metabolic reprogramming by targeting ATF3 in esophageal squamous cell carcinoma.

Carfilzomib, a second-generation proteasome inhibitor, has been approved as a treatment for relapsed and/or refractory multiple myeloma. Nevertheless, the molecular mechanism by which Carfilzomib inhibits esophageal squamous cell carcinoma (ESCC) progression largely remains to be determined. In the present study, we found that Carfilzomib demonstrated potent anti-tumor activity against esophageal squamous cell carcinoma both in vitro and in vivo. Mechanistically, carfilzomib triggers mitochondrial apoptosis and reprograms cellular metabolism in ESCC cells. Moreover, it has been identified that activating transcription factor 3 (ATF3) plays a crucial cellular target role in ESCC cells treated with Carfilzomib. Overexpression of ATF3 effectively antagonized the effects of carfilzomib on ESCC cell proliferation, apoptosis, and metabolic reprogramming. Furthermore, the ATF3 protein is specifically bound to lactate dehydrogenase A (LDHA) to effectively suppress LDHA-mediated metabolic reprogramming in response to carfilzomib treatment. Research conducted in xenograft models demonstrates that ATF3 mediates the anti-tumor activity of Carfilzomib. The examination of human esophageal squamous cell carcinoma indicated that ATF3 and LDHA have the potential to function as innovative targets for therapeutic intervention in the treatment of ESCC. Our findings demonstrate the novel function of Carfilzomib in modulating ESCC metabolism and progression, highlighting the potential of Carfilzomib as a promising therapeutic agent for the treatment of ESCC.

Parasubthalamic calretinin neurons modulate wakefulness associated with exploration in male mice.

The parasubthalamic nucleus (PSTN) is considered to be involved in motivation, feeding and hunting, all of which are highly depending on wakefulness. However, the roles and underlying neural circuits of the PSTN in wakefulness remain unclear. Neurons expressing calretinin (CR) account for the majority of PSTN neurons. In this study in male mice, fiber photometry recordings showed that the activity of PSTNCR neurons increased at the transitions from non-rapid eye movement (non-REM, NREM) sleep to either wakefulness or REM sleep, as well as exploratory behavior. Chemogenetic and optogenetic experiments demonstrated that PSTNCR neurons were necessary for initiating and/or maintaining arousal associated with exploration. Photoactivation of projections of PSTNCR neurons revealed that they regulated exploration-related wakefulness by innervating the ventral tegmental area. Collectively, our findings indicate that PSTNCR circuitry is essential for the induction and maintenance of the awake state associated with exploration.

Paraventricular thalamus controls consciousness transitions during propofol anaesthesia in mice.

BACKGROUND: The neuronal mechanisms underlying propofol-induced modulation of consciousness are poorly understood. Neuroimaging studies suggest a potential role for non-specific thalamic nuclei in propofol-induced loss of consciousness. We investigated the contribution of the paraventricular thalamus (PVT), a midline thalamic nucleus that has been implicated in arousal control and general anaesthesia with inhaled anaesthetics, to loss and recovery of consciousness during propofol anaesthesia. METHODS: Polysomnographic recordings and righting reflex test were used to determine the transitions of loss and recovery of righting reflex, used as a measure of consciousness in mice, during propofol anaesthesia in mice under conditions mimicking clinical propofol administration. PVT neuronal activities were monitored using fibre photometry and regulated using optogenetic and chemogenetic methods. RESULTS: Population activities of PVT glutamatergic neurones began to decrease before propofol-induced loss of consciousness and rapidly increased to a peak at the onset of recovery of consciousness. Chemogenetic inhibition of PVT calretinin-expressing (PVTCR) neurones shortened onset (from 176 [35] to 127 [26] s; P=0.001) and prolonged return (from 1568 [611] to 3126 [1616] s; P=0.002) of righting reflex. Conversely, chemogenetic activation of PVTCR neurones exerted opposite effects. Furthermore, optogenetic silencing of PVTCR neurones accelerated transitions to loss of consciousness (from 205 [35] to 158 [44] s; P=0.027) and slowed transitions to recovery of consciousness (from 230 [78] to 370 [99] s; P=0.041). During a steady period of unconsciousness maintained with continuous propofol infusion, brief optical activation of PVTCR neurones restored cortical activity and arousal with a latency of about 5 s. CONCLUSIONS: The paraventricular thalamus contributes to the control of consciousness transitions in propofol anaesthesia in mice. This provides a potential neuroanatomical target for controlling consciousness to reduce anaesthetic dose requirements and side effects.

Celastrol upregulated ATG7 triggers autophagy via targeting Nur77 in colorectal cancer.

BACKGROUND: Celastrol is a biologically active ingredient extracted from Tripterygium wilfordii that has exerted properties of anti-cancer. We explored the anti-tumor activities of celastrol against colorectal cancer (CRC) and the potential signaling pathways involved in its mechanism in this study. PURPOSE: The main purpose was to investigate the anti-CRC effects of celastrol and its novel potential mechanisms. STUDY DESIGN: HCT-116 and SW480 cell lines were used for in vitro studies, the mouse xenograft model of CRC tumor was performed for in vivo studies. METHODS: The effects of celastrol on colorectal cancer cells in vitro and underlying mechanisms were examined by using western blot analysis, cell proliferation assays, PI and Annexin-V staining assays, immunofluorescence and qRT-PCR assay. CRC xenografts model and IHC-staining were mainly used to evaluate the effects of celastrol in vivo. RESULTS: The results demonstrated that celastrol induced apoptosis and inhibited proliferation in CRC cells. The expression of Nur77 influenced the anti-CRC effects of celastrol, and inhibitory effect of celastrol on CRC cells could be reversed by overexpressing Nur77. Celastrol induced autophagy and the autophagy inhibition enhanced the anti-CRC effects. The ATG7 was up-regulated obviously after celastrol treatment for Nur77 overexpressing CRC cancer cells. Treating mice implanted with CRC cells with celastrol showed that it effectively inhibited tumor growth, which was associated with the down-regulation of Nur77. Levels of Nur77 and ATG7 were correlated with survival in human colorectal cancer. CONCLUSION: Celastrol induced apoptosis and autophagy played an important role in human colorectal cancer, Nur77 was involved in the anti-CRC effect of celastrol and decreased expression of Nur77 induced high expression of ATG7. Celastrol exerted anti-CRC effects by inhibiting Nur77 to induce high expression of ATG7 signaling and Nur77/ATG7 signaling may be a potential pathway for colorectal cancer treatment.

Hepatocyte nuclear factor 4 gamma (HNF4G) is correlated with poor prognosis and promotes tumor cell growth by inhibiting caspase-dependent intrinsic apoptosis in colorectal cancer.

The hepatocyte nuclear factor 4 gamma (HNF4G), a member of orphan nuclear receptors, is up-regulated and functions as an oncoprotein in a variety of tumors. Recent advances in understanding the biologic function and action mechanism of HNF4G in colorectal cancer (CRC) have not been fully elucidated. In the present study, we observed that HNF4G expression levels were significantly increased in CRC tissues compared with adjacent normal tissues, and HNF4G overexpression correlated with worse prognosis in colorectal cancer. Transfection with a small interference RNA (siRNA) targeting HNF4G in HCT116 and SW480 CRC cell lines significantly inhibited cell proliferation and promoted apoptosis in vitro. In contrast, overexpression of HNF4G increased cell proliferation and decreased the percentage of apoptotic cells. Moreover, we discovered that HNF4G was involved in CRC cell apoptosis via the caspase-dependent intrinsic pathway. Finally, knockdown of HNF4G expression led to attenuated colorectal cancer growth and promoted apoptosis in a xenograft mouse model. Collectively, these results indicate that HNF4G exerts as an oncogenic role in colorectal cancer and provides a potential therapeutic target.

Lesion of intergeniculate leaflet GABAergic neurons attenuates sleep in mice exposed to light.

Light has immediate effects on sleep in rodents, but the neural pathways underlying the effect remain to be elucidated. The intergeniculate leaflet (IGL) containing GABAergic neurons receives direct retinal inputs. We hypothesized that IGL GABAergic neurons may mediate light-induced sleep. EEG/electromyogram recording, immunohistochemistry, electrophysiology, optogenetics, fiber photometry, behavioral tests, and cell-specific destruction were employed to investigate the role of IGL GABAergic neurons in the regulation of acute light-induced sleep. Here, EEG/electromyogram recordings revealed that acute light exposure during the nocturnal active phase in mice induced a significant increase in non-rapid eye movement and rapid eye movement sleep compared with controls. Immunohistochemistry showed that acute light exposure for 2 hours in the active phase induced an increase in c-Fos expression in the IGL, whereas lights-off in the rest phase inhibited it. Patch clamp coupled with optogenetics demonstrated that retinal ganglion cells had monosynaptic functional connections to IGL GABAergic neurons. Calcium activity by fiber photometry in freely behaving mice showed that light exposure increased the activity of IGL GABAergic neurons. Furthermore, lesion of IGL GABAergic neurons by caspase-3 virus significantly attenuated the sleep-promoting effect of light exposure during active phases. Collectively, these results clearly indicated that the IGL is one of key nuclei mediating light-induced sleep in mice.

FTY720 Attenuates 6-OHDA-Associated Dopaminergic Degeneration in Cellular and Mouse Parkinsonian Models.

FTY720 (fingolimod) is the first oral drug approved for treating relapsing-remitting forms of multiple sclerosis. It is also protective in other neurological models including ischemia, Alzheimer's disease, Huntington disease and Rett syndrome. However, whether it might protect in a 6-hydroxydopamine (6-OHDA) mouse model associated with the dopaminergic pathology of Parkinson's disease (PD), has not been explored. Therefore, in the present study, we investigated the effects of FTY720 on 6-OHDA-induced neurotoxicity in cell cultures and mice. Here we show that FTY720 protected against 6-OHDA cytotoxicity and apoptosis in SH-SY5Y cells. We also show that prior administration of FTY720 to 6-OHDA lesioned mice ameliorated both motor deficits and nigral dopaminergic neurotoxicity, while also reducing 6-OHDA-associated inflammation. The protective effects of FTY720 were associated with activation of AKT and ERK1/2 pro-survival pathways and an increase in brain derived neurotrophic factor (BDNF) expression in vitro and in vivo. These findings suggest that FTY720 holds promise as a PD therapeutic acting, at least in part, through AKT/ERK1/2/P-CREB-associated BDNF expression.

Polysorbate 80-coated PLGA nanoparticles improve the permeability of acetylpuerarin and enhance its brain-protective effects in rats.

OBJECTIVES: Acetylpuerarin (AP) is an acetylated derivative of puerarin (PUE). The study aimed to prepare polysorbate 80-coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles to improve the permeability of AP across the blood-brain barrier (BBB) and enhance its brain-protective effects. METHODS: AP-loaded PLGA nanoparticles (AP-PLGA-NPs) were prepared using a solvent diffusion methodology. The NPs were characterized. The pharmacokinetics, tissue distributions and brain-protective effects of AP-PLGA-NPs were evaluated in animals. KEY FINDINGS: AP-PLGA-NPs were successfully prepared with a mean particle size of 145.0 nm and a zeta potential of -14.81 mV. The in-vitro release of AP from the PLGA-NPs showed a biphasic release profile. AP was metabolized into PUE in rats. The AUC0-∞ values of AP and PUE for AP-PLGA-NPs were 2.90- and 2.29-fold as great as those for AP solution, respectively. The values of the relative targeting efficiency in the brain were 2.40 and 2.58 for AP and PUE, and the ratios of peak concentration were 1.91 and 1.89 for AP and PUE, respectively. Compared with the crude drug, AP-PLGA-NPs showed better brain-protective effects in rats. CONCLUSION: Polysorbate 80-coated PLGA-NPs can improve the permeability of AP cross the BBB and enhance its brain-protective effects in rats.

Eriodictyol Attenuates ß-Amyloid 25-35 Peptide-Induced Oxidative Cell Death in Primary Cultured Neurons by Activation of Nrf2.

Oxidative stress plays an important role in the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD). Eriodictyol, a flavonoid isolated from the Chinese herb Dracocephalum rupestre, has long been established as an antioxidant. The present study was designed to investigate the effect of eriodictyol on ß-amyloid 25-35 peptide (Aß25-35)-induced oxidative cell death in primary neurons and to explore the role of the nuclear factor erythroid-2-related factor 2/antioxidant response element (Nrf2/ARE) pathway in this process. For this purpose, primary cultures of cortical neurons were exposed to 15 µM Aß25-35 in the absence or presence of eriodictyol (20, 40 and 80 µM). The results revealed that Aß25-35-induced cytotoxicity and apoptotic characteristics such as activation of JNK/p38 apoptotic signaling pathway were effectively attenuated by eriodictyol pretreatment. Eriodictyol treatment also resulted in an increase in Nrf2 protein levels and subsequent activation of ARE pathway genes in primary cultured neurons. The protective effects of eriodictyol were attenuated by RNA interference-mediated knockdown of Nrf2 expression. Taken together, these results clearly demonstrate that eriodictyol protects neurons against Aß25-35-induced cell death partially through Nrf2/ARE signaling pathway, which further supports that eriodictyol might be a promising novel therapeutic agent for AD.

S-allyl cysteine activates the Nrf2-dependent antioxidant response and protects neurons against ischemic injury in vitro and in vivo.

Stroke is a devastating clinical condition for which an effective neuroprotective treatment is currently unavailable. S-allyl cysteine (SAC), the most abundant organosulfur compound in aged garlic extract, has been reported to possess neuroprotective effects against stroke. However, the mechanisms underlying its beneficial effects remain poorly defined. The present study tests the hypothesis that SAC attenuates ischemic neuronal injury by activating the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent antioxidant response in both in vitro and in vivo models. Our findings demonstrate that SAC treatment resulted in an increase in Nrf2 protein levels and subsequent activation of antioxidant response element pathway genes in primary cultured neurons and mice. Exposure of primary neurons to SAC provided protection against oxygen and glucose deprivation-induced oxidative insults. In wild-type (Nrf2(+/+) ) mice, systemic administration of SAC attenuated middle cerebral artery occlusion-induced ischemic damage, a protective effect not observed in Nrf2 knockout (Nrf2(-/-) ) mice. Taken together, these findings provide the first evidence that activation of the Nrf2 antioxidant response by SAC is strongly associated with its neuroprotective effects against experimental stroke and suggest that targeting the Nrf2 pathway may provide therapeutic benefit for the treatment of stroke. The transcription factor Nrf2 is involved in cerebral ischemic disease and may be a promising target for the treatment of stroke. We provide novel evidence that SAC confers neuroprotection against ischemic stroke by activating the antioxidant Nrf2 signaling pathway. ARE, antioxidant response element; GCLC, glutathione cysteine ligase regulatory subunit; GCLM, glutathione cysteine ligase modulatory subunit; HO-1, heme oxygenase-1; JNK, c-Jun N-terminal kinase; Keap1, Kelch-like ECH-associated protein 1; Maf, musculoaponeurotic fibrosarcoma; Nrf2, nuclear factor erythroid-2-related factor 2; SAC, S-allyl cysteine; ROS, reactive oxygen species.

(-)-Epigallocatechin gallate protects against cerebral ischemia-induced oxidative stress via Nrf2/ARE signaling.

(-)-Epigallocatechin gallate (EGCG) has recently been shown to exert neuroprotection in a variety of neurological diseases; however, its role and the underlying mechanisms in cerebral ischemic injury are not fully understood. This study was conducted to investigate the potential neuroprotective effects of EGCG and the possible role of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway in the putative neuroprotection against experimental stroke in rats. The results revealed that EGCG exhibit significant neuroprotection, as evidenced by reduced infarction size and the decrease in transferase dUTP nick end labeling-positive neurons. Furthermore, EGCG also enhanced levels of Nrf2 and its downstream ARE pathway genes such as heme oxygenase-1, glutamate-cysteine ligase modulatory subunit and glutamate-cysteine ligase regulatory subunit, as compared to control groups. In accordance with its induction of Nrf2 activation, EGCG exerted a robust attenuation of reactive oxygen species generation and an increase in glutathione content in ischemic cortex. Taken together, these results demonstrated that EGCG exerted significant antioxidant and neuroprotective effects following focal cerebral ischemia, possibly through the activation of the Nrf2/ARE signaling pathway.

Naringenin protects against 6-OHDA-induced neurotoxicity via activation of the Nrf2/ARE signaling pathway.

There is increasing evidence that oxidative stress is critically involved in the pathogenesis of Parkinson's disease (PD), suggesting that pharmacological targeting of the antioxidant machinery may have therapeutic value. Naringenin, a natural flavonoid compound, has been reported to possess neuroprotective effect against PD related pathology; however the mechanisms underlying its beneficial effects are poorly defined. Thus, the purpose of the present study was to investigate the potential neuroprotective role of naringenin and to delineate its mechanism of action against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in models of PD both in vitro and in vivo. Naringenin treatment resulted in an increase in nuclear factor E2-related factor 2 (Nrf2) protein levels and subsequent activation of antioxidant response element (ARE) pathway genes in SH-SY5Y cells and in mice. Exposure of SH-SY5Y cells to naringenin provided protection against 6-OHDA-induced oxidative insults that was dependent on Nrf2, since treatment with Nrf2 siRNA failed to block against 6-OHDA neurotoxicity or induce Nrf2-dependent cytoprotective genes in SH-SY5Y cells. In mice, oral administration of naringenin resulted in significant protection against 6-OHDA-induced nigrostriatal dopaminergic neurodegeneration and oxidative damage. Our results indicate that activation of Nrf2/ARE signaling by naringenin is strongly associated with its neuroprotective effects against 6-OHDA neurotoxicity and suggest that targeting the Nrf2/ARE pathway may be a promising approach for therapeutic intervention in PD.

Eriodictyol-7-O-glucoside activates Nrf2 and protects against cerebral ischemic injury.

Stroke is a complex disease that may involve oxidative stress-related pathways in its pathogenesis. The nuclear factor erythroid-2-related factor 2/antioxidant response element (Nrf2/ARE) pathway plays an important role in inducing phase II detoxifying enzymes and antioxidant proteins and thus has been considered a potential target for neuroprotection in stroke. The aim of the present study was to determine whether eriodictyol-7-O-glucoside (E7G), a novel Nrf2 activator, can protect against cerebral ischemic injury and to understand the role of the Nrf2/ARE pathway in neuroprotection. In primary cultured astrocytes, E7G increased the nuclear localization of Nrf2 and induced the expression of the Nrf2/ARE-dependent genes. Exposure of astrocytes to E7G provided protection against oxygen and glucose deprivation (OGD)-induced oxidative insult. The protective effect of E7G was abolished by RNA interference-mediated knockdown of Nrf2 expression. In vivo administration of E7G in a rat model of focal cerebral ischemia significantly reduced the amount of brain damage and ameliorated neurological deficits. These data demonstrate that activation of Nrf2/ARE signaling by E7G is directly associated with its neuroprotection against oxidative stress-induced ischemic injury and suggest that targeting the Nrf2/ARE pathway may be a promising approach for therapeutic intervention in stroke.

Phase-transition and aggregation characteristics of a thermoresponsive dextran derivative in aqueous solutions.

Grafting of poly(N-vinylcaprolactam) side chains onto a hydrophilic dextran backbone was found to provide the dextran with new, thermoresponsive properties in aqueous solutions. Depending on its solution concentration, the resulting dextran derivative could exhibit a temperature-induced phase-transition and critical transition temperature (T(c)). Different anions and cations of added salts, including five potassium salts and five alkali-metal chlorides, were observed to influence the T(c) value of its aqueous solution. Except for potassium iodide, all added salts were found to lower the T(c) value. The addition of the surfactant, cationic cetyltrimethylammonium bromide or anionic sodium dodecyl sulfate, resulted in an increase of the T(c) value. With the help of the Coomassie Brilliant Blue dye as a polarity probe, the formation of hydrophobic aggregates above the T(c) was revealed for this new dextran derivative in aqueous solution.