The aim of the present study was to explore the effects of BRAF-activated non-protein coding RNA (BANCR) on pancreatic microlymphangiogenesis in pancreatic cancer (PC) and its molecular mechanism under hypoxic conditions. Reverse transcription-quantitative PCR (RT-qPCR) was used to detect the expression of BANCR in SW1990 and PANC-1 PC cell lines under normoxic and hypoxic conditions. Subsequently, the expression of BANCR in the PC cells was knocked down using small interfering RNAs (siRNAs). Western blotting and RT-qPCR analyses were performed to detect the expression of hypoxia-inducible factor (HIF-1α), VEGF-C and VEGFR-3 in the transfected cells. In addition, the transfected PC cells were co-cultured with human lymphatic endothelial cells and the lymphatic microvessel density (MLVD) was detected under normal and hypoxic conditions. Furthermore, HIF-1α expression in the PC cells was knocked down using siRNAs, and VEGF-C and VEGFR-3 mRNA expression in the HIF-1α knockdown cells was detected using RT-qPCR. The results showed that the expression of BANCR in the SW1990 and PANC-1 PC cell lines was significantly higher than that in human pancreatic duct endothelial cells. Additionally, the expression of BANCR was significantly increased in PC cells under hypoxic conditions compared with normoxic conditions. The MLVD of PC cells under hypoxic conditions was significantly higher compared with that under normoxic conditions, and the MLVD in the si-BANCR group was lower than that in the si-NC group, indicating that si-BANCR downregulated MLVD. These results indicate that BANCR positively regulated the expression of HIF-1α in PC cells at the transcriptional and translational levels. Finally, the expression levels of VEGF-C and VEGFR-3 in PC cells were significantly reduced when BANCR or HIF-1α expression was knocked down. In conclusion, the results demonstrate that the expression of BANCR in PC cells was significantly increased under hypoxic conditions and suggest that BANCR promoted tumor cell lymphangiogenesis by upregulating the HIF-1α/VEGF-C/VEGFR-3 pathway, which plays an important role in the process of PC lymph node metastasis.
Cerebral ischemia-reperfusion (I/R) incites neurologic damage through a myriad of complex pathophysiological mechanisms, most notably, inflammation and oxidative stress. In I/R injury, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) produces reactive oxygen species (ROS), which promote inflammatory and apoptotic pathways, augmenting ROS production and promoting cell death. Inhibiting ischemia-induced oxidative stress would be beneficial for reducing neuroinflammation and promoting neuronal cell survival. Studies have demonstrated that chlorpromazine and promethazine (C+P) induce neuroprotection. This study investigated how C+P minimizes oxidative stress triggered by ischemic injury. Adult male Sprague-Dawley rats were subject to middle cerebral artery occlusion (MCAO) and subsequent reperfusion. 8 mg/kg of C+P was injected into the rats when reperfusion was initiated. Neurologic damage was evaluated using infarct volumes, neurological deficit scoring, and TUNEL assays. NOX enzymatic activity, ROS production, protein expression of NOX subunits, manganese superoxide dismutase (MnSOD), and phosphorylation of PKC-δ were assessed. Neural SHSY5Y cells underwent oxygen-glucose deprivation (OGD) and subsequent reoxygenation and C+P treatment. We also evaluated ROS levels and NOX protein subunit expression, MnSOD, and p-PKC-δ/PKC-δ. Additionally, we measured PKC-δ membrane translocation and the level of interaction between NOX subunit (p47phox) and PKC-δ via coimmunoprecipitation. As hypothesized, treatment with C+P therapy decreased levels of neurologic damage. ROS production, NOX subunit expression, NOX activity, and p-PKC-δ/PKC-δ were all significantly decreased in subjects treated with C+P. C+P decreased membrane translocation of PKC-δ and lowered the level of interaction between p47phox and PKC-δ. This study suggests that C+P induces neuroprotective effects in ischemic stroke through inhibiting oxidative stress. Our findings also indicate that PKC-δ, NOX, and MnSOD are vital regulators of oxidative processes, suggesting that C+P may serve as an antioxidant.
ObjectiveDynamic changes in ischemic pathology after stroke suggested a “critical window” of enhanced neuroplasticity immediately after stroke onset. Although physical exercise has long been considered a promising strategy of stroke rehabilitation, very early physical exercise may exacerbate brain injury. Since remote ischemic conditioning (RIC) promotes neuroprotection and neuroplasticity, the present study combined RIC with sequential exercise to establish a new rehabilitation strategy for a better rehabilitative outcome.MethodsA total of 120 adult male Sprague‐Dawley rats were used and divided into five groups: (1) sham, (2) stroke, (3) stroke with exercise, (4) stroke with RIC, and (5) stroke with RIC followed by exercise. Brain damage was evaluated by infarct volume, neurological deficit, cell death, and lactate dehydrogenase (LDH) activity. Long‐term functional outcomes were determined by grid walk tests, rotarod tests, beam balance tests, forelimb placing tests, and the Morris water maze. Neuroplasticity was evaluated through measurements of both mRNA and protein levels of synaptogenesis (synaptophysin [SYN], post‐synaptic density protein‐95 [PSD‐95], and brain‐derived neurotrophic factor [BDNF]) and angiogenesis (vascular endothelial growth factor [VEGF], angiopoietin‐1 [Ang‐1], and angiopoietin‐2 [Ang‐2]). Inflammasome activation was measured by concentrations of interleukin‐18 (IL‐18) and IL‐1β detected by enzyme‐linked immunosorbent assay (ELISA) kits, mRNA expressions of NLR pyrin domain containing 3 (NLRP3), apoptosis‐associated speck‐like protein containing a C‐terminal caspase recruitment domain (ASC), IL‐18 and IL‐1β, and protein quantities of NLRP3, ASC, cleaved‐caspase‐1, gasdermin D‐N (GSDMD‐N), and IL‐18 and IL‐1β. Stress granules (SGs), including GTPase‐activating protein‐binding protein 1 (G3BP1), T cell‐restricted intracellular antigen‐1 (TIA1), and DEAD‐box RNA helicase 3X (DDX3X) were evaluated at mRNA and protein levels. The interactions between DDX3X with NLRP3 or G3BP1 were determined by immunofluorescence and co‐immunoprecipitation.ResultsEarly RIC decreased infarct volumes, neurological deficits, cell death, and LDH activity at post‐stroke Day 3 (p < 0.05). All treatment groups showed significant improvement in functional outcomes, including sensory, motor, and cognitive functions. RIC and exercise, as compared to RIC or physical exercise alone, had improved functional outcomes after stroke (p < 0.05), as well as synaptogenesis and angiogenesis (p < 0.05). RIC significantly reduced mRNA and protein expressions of NLRP3 (p < 0.05). SGs formation peaked at 0 h after ischemia, then progressively decreased until 24 h postreperfusion, which was reversed by RIC (p < 0.05). The assembly of SGs consumed DDX3X and then inhibited NLRP3 inflammasome activation.ConclusionsRIC followed by exercise induced a better rehabilitation in ischemic rats, while early RIC alleviated ischemia‐reperfusion injury via stress‐granule‐mediated inhibition of NLRP3 inflammasome.
Pre‐stroke exercise conditioning reduces neurovascular injury and improves functional outcomes after stroke. The goal of this study was to explore if post‐stroke exercise conditioning (PostE) reduced brain injury and whether it was associated with the regulation of gluconeogenesis. Adult rats received 2 h of middle cerebral artery (MCA) occlusion, followed by 24 h of reperfusion. Treadmill activity was then initiated 24 h after reperfusion for PostE. The severity of the brain damage was determined by infarct volume, apoptotic cell death, and neurological deficit at one and three days after reperfusion. We measured gluconeogenesis including oxaloacetate (OAA), phosphoenolpyruvate (PEP), pyruvic acid, lactate, ROS, and glucose via ELISA, as well as the location and expression of the key enzyme phosphoenolpyruvate carboxykinase (PCK)‐1/2 via immunofluorescence. We also determined upstream pathways including forkhead transcription factor (FoxO1), p‐FoxO1, 3‐kinase (PI3K)/Akt, and p‐PI3K/Akt via Western blot. Additionally, the cytoplasmic expression of p‐FoxO1 was detected by immunofluorescence. Compared to non‐exercise control, PostE (*p < .05) decreased brain infarct volumes, neurological deficits, and cell death at one and three days. PostE groups (*p < .05) saw increases in OAA and decreases in PEP, pyruvic acid, lactate, ROS, glucose levels, and tissue PCKs expression on both days. PCK‐1/2 expressions were also significantly (*p < .05) suppressed by the exercise setting. Additionally, phosphorylated PI3K, AKT, and FoxO1 protein expression were significantly induced by PostE at one and three days (*p < .05). In this study, PostE reduced brain injury after stroke, in association with activated PI3K/AKT/FoxO1 signaling, and inhibited gluconeogenesis. These results suggest the involvement of FoxO1 regulation of gluconeogenesis underlying post‐stroke neuroprotection.
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