N-acetylserotonin alleviates retinal ischemia-reperfusion injury via HMGB1/RAGE/NF-κB pathway in rats.

AIM: To observe the effects of N-acetylserotonin (NAS) administration on retinal ischemia-reperfusion (RIR) injury in rats and explore the underlying mechanisms involving the high mobility group box 1 (HMGB1)/receptor for advanced glycation end-products (RAGE)/nuclear factor-kappa B (NF-κB) signaling pathway. METHODS: A rat model of RIR was developed by increasing the pressure of the anterior chamber of the eye. Eighty male Sprague Dawley were randomly divided into five groups: sham group (n=8), RIR group (n=28), RIR+NAS group (n=28), RIR+FPS-ZM1 group (n=8) and RIR+NAS+ FPS-ZM1 group (n=8). The therapeutic effects of NAS were examined by hematoxylin-eosin (H&E) staining, and retinal ganglion cells (RGCs) counting. The expression of interleukin 1 beta (IL-1ß), HMGB1, RAGE, and nod-like receptor 3 (NLRP3) proteins and the phosphorylation of nuclear factor-kappa B (p-NF-κB) were analyzed by immunohistochemistry staining and Western blot analysis. The expression of HMGB1 protein was also detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: H&E staining results showed that NAS significantly reduced retinal edema and increased the number of RGCs in RIR rats. With NAS therapy, the HMGB1 and RAGE expression decreased significantly, and the activation of the NF-κB/NLRP3 pathway was antagonized along with the inhibition of p-NF-κB and NLRP3 protein expression. Additionally, NAS exhibited an anti-inflammatory effect by reducing IL-1ß expression. The inhibitory of RAGE binding to HMGB1 by RAGE inhibitor FPS-ZM1 led to a significant decrease of p-NF-κB and NLRP3 expression, so as to the IL-1ß expression and retinal edema, accompanied by an increase of RGCs in RIR rats. CONCLUSION: NAS may exhibit a neuroprotective effect against RIR via the HMGB1/RAGE/NF-κB signaling pathway, which may be a useful therapeutic target for retinal disease.

[Protective effect of melatonin against oxygen-induced retinopathy: a study based on the HMGB1/NF-κB/NLRP3 axis]. / 基于HMGB1/NF-κB/NLRP3è½´æŽ¢è®¨è¤ªé»‘ç´ å¯¹æ°§è¯±å¯¼è§†ç½‘è†œç— å˜çš„ä¿æŠ¤ä½œç”¨.

OBJECTIVES: To study the protective effect of melatonin (Mel) against oxygen-induced retinopathy (OIR) in neonatal mice and the role of the HMGB1/NF-κB/NLRP3 axis. METHODS: Neonatal C57BL/6J mice, aged 7 days, were randomly divided into a control group, a model group (OIR group), and a Mel treatment group (OIR+Mel group), with 9 mice in each group. The hyperoxia induction method was used to establish a model of OIR. Hematoxylin and eosin staining and retinal flat-mount preparation were used to observe retinal structure and neovascularization. Immunofluorescent staining was used to measure the expression of proteins and inflammatory factors associated with the HMGB1/NF-κB/NLRP3 axis and lymphocyte antigen 6G. Colorimetry was used to measure the activity of myeloperoxidase. RESULTS: The OIR group had destruction of retinal structure with a large perfusion-free area and neovascularization, while the OIR+Mel group had improvement in destruction of retinal structure with reductions in neovascularization and perfusion-free area. Compared with the control group, the OIR group had significant increases in the expression of proteins and inflammatory factors associated with the HMGB1/NF-κB/NLRP3 axis, the expression of lymphocyte antigen 6G, and the activity of myeloperoxidase (P<0.05). Compared with the OIR group, the OIR+Mel group had significant reductions in the above indices (P<0.05). Compared with the control group, the OIR group had significant reductions in the expression of melatonin receptors in the retina (P<0.05). Compared with the OIR group, the OIR+Mel group had significant increases in the expression of melatonin receptors (P<0.05). CONCLUSIONS: Mel can alleviate OIR-induced retinal damage in neonatal mice by inhibiting the HMGB1/NF-κB/NLRP3 axis and may exert an effect through the melatonin receptor pathway.

Nest survival rate of Reeves's pheasant (Syrmaticus reevesii) based on artificial nest experiments.

To explore the nest survival rate of Reeves's pheasant(Syrmaticus reevesii) and the nest-site factors that affect it, we conducted artificial nest experiments with reference to natural nests at Dongzhai National Nature Reserve(DNNR), Henan Province and Pingjingguan, Hubei Province from April to June 2014 simulating the situation in its early and later breeding season. We also determined distance characteristics of the nest sites by ArcGIS 10.0. Nest survival models were constructed in Program MARK for data analysis. Results indicated that in the early breeding season, the apparent survival rate(ASR) in DNNR(52.4%) was significantly greater than that in Pingjingguan(13.5%), and the ASR in the later breeding season in DNNR(26.7%) was not indistinctively correlated with Pingjingguan(3.2%). The daily survival rate(DSR) in the later breeding season was 93.8% in DNNR and 92.0% in Pingjingguan, respectively. The DSRs were both negatively correlated with nest distance to forest edges and settlements. The DSR in Pingjingguan was positively correlated with nest distance to paths and negatively correlated with nest distance to water sources. However, the DSR in DNNR was negatively correlated with nest distance to paths but positively correlated with nest distance to water sources.

[Potential nest predators of Syrmaticus reevesii based on camera traps and artificial nests.] / åŸºäºŽçº¢å¤–ç›¸æœºæŠ€æœ¯å’Œäººå·¥å·¢è¯•éªŒåˆ†æžç™½å† é•¿å°¾é›‰å·¢æ½œåœ¨æ•é£Ÿè€ .

In order to understand the background of the field breeding ecology of Reeves's pheasant (Syrmaticus reevesii) inside and outside of protected area, an investigation on nest predation rate, potential nest predators and the habitat factors affecting nest predation was conducted at Dongzhai National Nature Reserve, Henan Province and Pingjingguan Village, Hubei Province, which were protected and non-protected area, respectively. The fieldwork was conducted from March to July 2014, and artificial nests (taking eggs as bait), camera traps and habitat plots were used at these two sites to catch information about nest predation. Experiments were designed in two rounds, including the early-breeding stage (March to April) and mid-breeding stage (May to June). We placed 149 artificial ground nests with 62 randomly picked nest sites, each monitored by one camera. The working days of all cameras were 1315 days, and we finally obtained 7776 pictures and 6950 video clips. The results showed that the rate of nest predation outside the protected areas (Pingjingguan) was higher than that in nature reserve (Dongzhai), with highly significant diffe-rences both in early-breeding and mid-breeding stages. In two stages, more nest predator species (11 and 6 species in two stages, respectively) occurred in Pingjingguan than in Dongzhai (7 and 5 species, respectively). In Pingjingguan, Glires and Corvidae were top predators, while in Dongzhai Raccoon dog (Nyctereutes procyonoides) was firstly ranked. Slope degree and arbor canopy cover were positively related with the nest predation rate in Pingjingguan, while fallen leaves coverage had significant influence on nest predation in Dongzhai. We also found wild Reeves's pheasant paid visits to 13 artificial nests for 18 times by viewing the pictures and video clips.

[Therapeutic effect of in vitro 5-aza-2'-deoxycytidine combined with imatinib on gastrointestinal stromal tumor].

OBJECTIVE: To investigate the impact of 5-aza-2'-deoxycytidine(5-aza-CdR) combined with imatinib on the proliferation, motility, invasion, and apoptosis of gastrointestinal stromal tumors(GIST) cells in vitro. METHODS: MTT assay was used to investigate the effect of the two agents on proliferation of GIST882. Plate colony forming assay was used to determine the number of colony-forming. Motility and invasion abilities were tested to evaluate the inhibitory effect of each agent. Flow cytometry was used to observe apoptosis and cell cycle. RESULTS: 5-aza-CdR or imatinib effectively inhibited the growth of GIST882 cells in concentration- and time-dependent manner. The inhibitory rate of combined treatment using 5-aza-CdR and imatinib was significantly higher than that of 5-aza-CdR or imatinib alone(P<0.05). After treatment for 48 h, the apoptosis rates of 5-aza-CdR group (1000 µg/L) and imatinib group (100 µmol/L) were (11.7±1.2)% and (14.6±0.8)%, respectively. Compared with the control group (2.8±0.3)%, the difference was statistically significant(P=0.000). Furthermore, the difference in apoptosis rate was significant between combined treatment group (19.4±1.1)% and single drug treatment group(vs. 5-aza-CdR group, P=0.000, vs. imatinib group, P=0.013). 5-aza-CdR raised G0/G1 ratio and reduced S ratio of GIST882. Imatinib and combined group had no apparent influence on the cell cycle of GIST882 cells. CONCLUSION: 5-aza-CdR may be a potential agent of GIST treatment in the near future.

Relationship and prognostic significance of SPARC and VEGF protein expression in colon cancer.

BACKGROUND: SPARC (secreted protein, acidic and rich in cysteine) is closely related with the progress, invasion and metastasis of malignant tumor and angiogenesis. METHODS: Using human colon adenocarcinoma tissues (hereinafter referred to as colon cancer) and their corresponding non-diseased colon from 114 patients' biopsies, the expression of SPARC and vascular endothelial growth factor (VEGF) were investigated by immunohistochemistry staining to assessment the relationship between SPARC and VEGF, as well as their prognostic significance in patients. Evaluation of VEGF expression level with the same tissues was used to establish the antigenic profiles, and the marker of CD34 staining was used as an indicator of microvessel density (MVD). RESULTS: SPARC expression was mainly in the stromal cells surrounding the colon cancer, and was significant difference in those tissues with the lymph node metastasis and differentiation degree of tumor. Expression of SPARC was significantly correlated with the expression of VEGF and MVD in colon cancer tissues. Patients with low or absence expressing SPARC had significantly worse overall survival and disease-free survival in a Single Factor Analysis; Cox Regression Analysis, SPARC emerged as an overall survival and disease-free survival independent prognostic factor for colon cancer. CONCLUSION: The low expression or absence of stromal SPARC was an independent prognostic factor for poor prognosis of colon cancer. SPARC maybe involved in the regulation of anti-angiogenesis by which it may serve as a novel target for colon cancer treatment as well as a novel distinctive marker.