Yunen Liu

Blueberry Anthocyanins-Enriched Extracts Attenuate Cyclophosphamide-Induced Cardiac Injury

We sought to explore the effect of blueberry anthocyanins-enriched extracts (BAE) on cyclophosphamide (CTX)-induced cardiac injury. The rats were divided randomly into five groups including normal control, CTX 100 mg/kg, BAE 80mg/kg, CTX+BAE 20mg/kg and CTX+BAE 80mg/kg groups. The rats in the three BAE-treated groups were administered BAE for four weeks. Seven days after BAE administration, rats in CTX group and two BAE-treated groups were intraperitoneally injected with a single dose of 100 mg/kg CTX. Cardiac injury was assessed using physiological parameters, Echo, morphological staining, real-time PCR and western blot. In addition, cardiotoxicity indices, inflammatory cytokines expression and oxidative stress markers were also detected. Four weeks 20mg/kg and 80mg/kg dose of BAE treatment following CTX exposure attenuated mean arterial blood pressure, heart rate and activities of heart enzymes, improved cardiac dysfunction, left ventricular hypertrophy and fibrosis. Importantly, BAE also attenuated CTX-induced LV leukocyte infiltration and inflammatory cytokines expression, ameliorated oxidative stress as well as cardiomyocyte apoptosis. In conclusion, BAE attenuated the CTX-induced cardiac injury and the protective mechanisms were related closely to the anti-inflammatory, antioxidant and anti-inflammatory characteristics of BAE.

Anti-edema effect of melatonin on spinal cord injury in rats.

AIM To determine the anti-edema effects of melatonin on spinal cord injury (SCI) in rats. METHODS A total of 150 adult male Sprague-Dawley rats were randomly allocated to the following three groups (n=50): a sham group which underwent laminectomy without dural compression; an SCI group, which underwent laminectomy followed by SCI and received saline i.p. immediately after injury and then daily for 2 days; an MT group, which underwent laminectomy followed by SCI and received a 100 mg/kg dose of melatonin i.p. immediately after SCI and then daily for 2 days. The cords were removed at 12, 24, 48 and 72 h after surgery in every group. Spinal cord edema was evaluated by determining the spinal cord water content. Expressions of AQP4 and GFAP positive cells in injured spinal cord were detected by immunohistochemical staining, and protein expressions of AQP4 and GFAP were detected by Western blotting. RESULTS Spinal cord water content was obviously increased after SCI, which was maintained almost unchanged by melatonin treatment (100 mg/kg) at 12 h after injury but was significantly reduced from 24 h to 72 h. The expressions of AQP4 and GFAP increased in the injured spinal cord segments, which were decreased by melatonin treatment (100 mg/kg) between 24 h and 72 h after SCI. CONCLUSIONS Melatonin (100 mg/kg) had anti-edema effects after acute SCI probably by down-regulating the expression level of AQP4 protein, and it may eliminate astrocytic swelling after SCI through down-regulating the expression level of GFAP protein.

Blueberry anthocyanins-enriched extracts attenuate the cyclophosphamide-induced lung toxicity

The influence of blueberry anthocyanins-enriched extracts (BAE) on cyclophosphamide (CTX)-induced lung damage was investigated. BAE (20 and 80mg/kg/d) were orally dosed to rats 7d both before and after CTX administration (100mg/kg, intraperitoneal injection, single dose). The results showed CTX treatment induced obvious pathological pulmonary injury with raised injury score and lung/body weight ratio. In CTX group, the activity of lysosomal proteases, lung permeability and the number of neutrophil infiltrates all elevated. On the other hand, claudin-4 and zonula occluden-1 protein levels decreased. And also changes of oxidative stress and inflammatory cytokines parameters together with nuclear factor-κB activation were shown. Improvement of all above-mentioned physiological and biochemical parameters was exhibited in BAE groups, with a dose-dependent manner. In conclusion, BAE attenuate the CTX-induced lung toxicity, antioxidant and anti-inflammatory characteristics are involved in the protective mechanism of BAE.

Cold stress-induced brain injury regulates TRPV1 channels and the PI3K/AKT signaling pathway

Transient receptor potential vanilloid 1 (TRPV1) is a nonselective cation channel that interacts with several intracellular proteins in vivo, including calmodulin and Phosphatidylinositol-3-Kinase/Protein Kinase B (PI3K/Akt). TRPV1 activation has been reported to exert neuroprotective effects. The aim of this study was to examine the impact of cold stress on the mouse brain and the underlying mechanisms of TRPV1 involvement. Adult male C57BL/6 mice were subjected to cold stress (4°C for 8h per day for 2weeks). The behavioral deficits of the mice were then measured using the Morris water maze. Expression levels of brain injury-related proteins and mRNA were measured by western blot, immunofluorescence or RT-PCR analysis. The mice displayed behavioral deficits, inflammation and changes in brain injury markers following cold stress. As expected, upregulated TRPV1 expression levels and changes in PI3K/Akt expression were found. The TRPV1 inhibitor reduced the levels of brain injury-related proteins and inflammation. These data suggest that cold stress can induce brain injury, possibly through TRPV1 activation and the PI3K/Akt signaling pathway. Suppression of inflammation by inhibition of TRPV1 and the PI3K/Akt pathway may be helpful to prevent cold stress-induced brain injury.

In vitro effects of recombinant adenovirus-mediated bone morphogenetic protein 2/vascular endothelial growth factor 165 on osteogenic differentiation of bone marrow mesenchymal stem cells

Abstract Mouse bone marrow mesenchymal stem cells C3H10T1/2 were divided into Ad-BMP2 (bone morphogenetic protein 2) group, Ad-VEGF165 (vascular endothelial growth factor 165) group, Ad-VEGF165 + Ad-BMP2 group, empty adenovirus group and control group. BMP2 and VEGF165 were highly co-expressed in Ad-VEGF165 + Ad-BMP2 group. Ad-BMP2 and Ad-VEGF165 + Ad-BMP2 groups, especially the latter (P < 0.05), had significantly higher expression levels of osteocalcin, osteoprotegerin, and osteopontin mRNA and OPN protein (P < 0.05). Ad-VEGF165 + Ad-BMP2 group had highest alkaline phosphatase (ALP) activity, strongest ALP staining and most calcium salt deposits (P < 0.05). Combining VEGF165 obviously enhanced the inducing effects of BMP2 on osteogenic differentiation capacity of C3H10T1/2 cells.

Melatonin exerts protective effect on N2a cells under hypoxia conditions through Zip1/ERK pathway

Melatonin plays a neuroprotective role in different CNS injuries. However, the molecular mechanisms underlying neuroprotection by melatonin are not well understood. Here, we studied the effects of melatonin in hypoxia-induced N2a cells and our results demonstrated that melatonin not only reduced the level of ROS and MDA, induced the increase of SOD, but also increased the cell proliferation and inhibited cell apoptosis in hypoxia-induced N2a cells. Moreover, we identified that melatonin can activate the MAPK/ERK pathway via upregulating the expression of Zip1. Therefore, this study provides a new mechanism of melatonin and need our further study in detail.

Cold exposure induced oxidative stress and apoptosis in the myocardium by inhibiting the Nrf2-Keap1 signaling pathway

BackgroundExposure to cold weather is associated with infaust cardiovascular responses, including myocardial infarction and arrhythmias. However, the exact mechanisms of these adverse changes in the myocardium under cold stress are unknown. This study was designed to investigate the mechanisms of cardiac injury induced by cold stress in mice.MethodsThe mice were randomly divided into three groups, normal control (no handling), 1-week cold stress and 2-week cold stress. We observed physiological changes of the mice and morphological changes of myocardium tissues, and we measured the changes of 3′-nitrotyrosine and 4-hydroxynonenal, the expression levels of superoxide dismutase-1, superoxide dismutase-2, Bax, Bad, Bcl-2, Nuclear factor erythroid-derived 2-like 2 (Nrf2) and Kelch like-ECH-associated protein 1 (Keap1) in myocardium by western blot. Besides, we detected mRNA of superoxide dismutase-1, superoxide dismutase-2, Bax, Bad, Bcl-2, Nrf2 and Keap1 by real-time PCR. One-way analysis of variance, followed by LSD-t test, was used to compare each variable for differences among the groups.ResultsEchocardiography analyses demonstrated left ventricle dysfunction in the groups receiving cold stress. Histological analyses witnessed inflammation, vacuolar and eosinophilic degeneration occurred in left ventricle tissues. Western blotting results showed increased 3′-nitrotyrosine and 4-hydroxynonenal and decreased antioxidant enzymes (superoxide dismutase-1 and superoxide dismutase-2) in the myocardium. Expression of Nrf2 and Keap1 followed a downward trend under cold exposure, as indicated by western blotting and real-time PCR. Expression of anti-apoptotic protein Bcl-2 also showed the same trend. In contrast, expression of pro-apoptotic proteins Bax and Bad followed an upward trend under cold exposure. The results of real-time PCR were consistent with those of western blotting.ConclusionsThese findings were very significant, showing that cold exposure induced cardiac injury by inhibiting the Nrf2-Keap1 signaling pathway.

Role of platelet derived growth factor (PDGF) in reverting neuronal nuclear and soma size alterations in NSC-34 cells exposed to cerebrospinal fluid from amyotrophic lateral sclerosis patients

PURPOSE Amyotrophic lateral sclerosis (ALS) or motor neuron disease is an adult-onset progressive neurodegenerative disorder. ALS-CSF has been shown to produce toxic effects on motor neuron cells like aberrant neurofilament phosphorylation and morphological alterations of nuclear and soma size. Our current study was designed to investigate the neuroprotective role of platelet derived growth factor (PDGF) in reverting the adverse effects produced by ALS-CSF. METHODS Our present study was carried out to determine the restorative potential of PDGF on the toxic effects of ALS-CSF on NSC motor neuron cells from patients. Therefore the cells were divided in to three groups: (a) normal control (NC) - the cells were not exposed to ALS-CSF; (b) ALS group - the cells were exposed to ALS-CSF; (c) NALS group - the cells were exposed to non ALS CSF. Further each of these groups was supplemented with PDGF. RESULTS AND CONCLUSIONS We observed that the mean area of nucleus and cell soma of the differentiated NSC motor neuron cells was significantly reduced in the cells exposed to ALS-CSF. We also observed that subsequent treatment with PDGF restored the soma area and nucleus of the ALS-CSF exposed cells significantly. Taken together, we show that supplementation with PDGF restores the morphological changes induced by ALS-CSF and PDGF may play a significant role in protecting motor neurons from apoptosis in ALS and thereby it promoting the cell survival.

Chitosan oligosaccharide ameliorates acute lung injury induced by blast injury through the DDAH1/ADMA pathway.

Objective To investigate the protective effect of chitosan oligosaccharide (COS) on acute lung injury (ALI) caused by blast injury, and explore possible molecular mechanisms. Methods A mouse model of blast injury-induced ALI was established using a self-made explosive device. Thirty mice were randomly assigned to control, ALI and ALI + COS groups. An eight-channel physiological monitor was used to determine the mouse physiological index. Enzyme linked immunosorbent assay was used to measure serum inflammatory factors. Hematoxylin-eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, immunofluorescence staining, real time-polymerase chain reaction and western blot assay were used to detect inflammatory reactions, oxidative stress and apoptosis. Results Mice were sacrificed 24 hours after successful model induction. Compared with the ALI group, the heart rate, respiration and PCO2 were significantly lower, but the PO2, TCO2 and HCO3- were significantly higher in the ALI + COS group. Compared to ALI alone, COS treatment of ALI caused a significant decrease in the wet/dry lung weight ratio, indicating a reduction in lung edema, inflammatory cell infiltration, levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-4, IL-6 and nuclear factor kappa B mRNA and protein expression were reduced and IL-10 mRNA and protein expression was increased (P < 0.05). COS significantly inhibited reactive oxygen species, MDA5 and IREα mRNA and protein expressions, cell apoptosis and Bax and Caspase-3 mRNA and protein expressions, and significantly increased superoxide dismutase-1 mRNA expression, and Bcl-2 and Caspase-8 mRNA and protein expression (all P<0.05). COS significantly increased dimethylarginine dimethylaminohydrolase 1 (DDAH1) protein expression, and reduced ADMA and p38 protein expression (P< 0.05). Conclusion Blast injury causes inflammation, oxidative stress and apoptosis in the lung tissues of mice. COS has protective effects on blast injury-induced ALI, possibly by promoting DDAH1 expression and inhibiting ADMA and mitogen-activated protein kinase pathways.

Shock waves increase pulmonary vascular leakage, inflammation, oxidative stress, and apoptosis in a mouse model

Severe lung damage is a major cause of death in blast victims, but the mechanisms of pulmonary blast injury are not well understood. Therefore, it is important to study the injury mechanism of pulmonary blast injury. A model of lung injury induced by blast exposure was established by using a simulation blast device. The effectiveness and reproducibility of the device were investigated. Eighty mice were randomly divided into eight groups: control group and 3 h, 6 h, 12 h, 24 h, 48 h, 7 days and 14 days post blast. The explosive device induced an explosion injury model of a single lung injury in mice. The success rate of the model was as high as 90%, and the degree of lung injury was basically the same under the same pressure. Under the same conditions, the thickness of the aluminum film can be from 0.8 mm to 1.6 mm, and the peak pressure could be from 95.85 ± 15.61 PSI to 423.32 ± 11.64 PSI. There is no statistical difference in intragroup comparison. A follow-up lung injury experiment using an aluminum film thickness of 1.4 mm showed a pressure of 337.46 ± 18.30 PSI induced a mortality rate of approximately 23.2%. Compared with the control group (372 ± 23 times/min, 85.9 ± 9.4 mmHg, 4.34 ± 0.09), blast exposed mice had decreased heart rate (283 ± 21 times/min) and blood pressure (73.6 ± 3.6 mmHg), and increased lung wet/dry weight ratio(2.67 ± 0.11), marked edematous lung tissue, ruptured blood vessels, infiltrating inflammatory cells, increased NF-κB (4.13 ± 0.01), TNF-α (4.13 ± 0.01), IL-1β (2.43 ± 0.01) and IL-6 (4.65 ± 0.01) mRNA and protein, decreased IL-10(0.18 ± 0.02) mRNA and protein (P < 0.05). The formation of ROS and the expression of MDA5 (4.46 ± 0.01) and IREα (3.43 ± 0.00) mRNA and protein were increased and the expression of SOD-1 (0.28 ± 0.02) mRNA and protein was decreased (P < 0.05). Increased expression of Bax (3.54 ± 0.00) and caspase 3 (4.18 ± 0.01) mRNA and protein inhibited the expression of Bcl-2 (0.39 ± 0.02) mRNA and protein. The changes of pulmonary edema, inflammatory cell infiltration, and cell damage factor expression increased gradually with time, and reached the peak at 12–24 h after the outbreak, and returned to normal at 7–14 days. Detonation injury can lead to edema of lung tissue, pulmonary hemorrhage, rupture of pulmonary vessels, induction of early inflammatory responses accompanied by increased oxidative stress in lung tissue cells and increased apoptosis in mice experiencing blast injury. The above results are consistent with those reported in other literatures. It is showed that the mouse lung blast injury model is successfully modeled, and the device can be used for the study of pulmonary blast injury. Impact statement The number of patients with explosive injury has increased year by year, but there is no better treatment. However, the research on detonation injury is difficult to carry out. One of the factors is the difficulty in making the model of blast injury. The laboratory successfully developed and produced a simulation device of explosive knocking through a large amount of literature data and preliminary experiments, and verified the preparation of the simulation device through various experimental techniques. The results showed that the device could simulate the shock wave-induced acute lung injury generated, which was similar to the actual knocking injury. The experimental process was controlled. Under the same condition, there was no statistical difference between the groups. It is possible to realize miniaturization and precision of an explosive knocking simulation device, which is a good experimental tool for further research on the mechanism of organ damage caused by detonation and the development of protective drugs.