Advanced glycation end products initiate the mutual promoting cycle between centrosome amplification and the release of inflammatory cytokines in human vascular endothelial cells.

Inflammation is implicated in the development of diabetic complications including vascular pathology. Centrosome is known to play a role in cell secretion. We have reported that diabetes can trigger centrosome amplification (CA). Thus, in the present study, we investigated the relationship between CA and the release of proinflammatory cytokines interleukin-1ß, tumor necrosis factor-α and interleukin-6 in hCMEC/D3 human endothelial cells treated with advanced glycation end products (AGEs). We found that AGEs induced CA via PLK4 and increased the biosynthesis of the three cytokines via NF-κB. Importantly, treatment of the cells with AGEs also increased the release of the three cytokines. Inhibiting CA by knockdown of polo like kinase 4 (PLK4) attenuated the cytokine release but not their biosynthesis. Knockdown of the cytokines inhibited the CA, while addition of the cytokines individually to the cell culture increased the protein level of PLK4 and CA to a moderate level. Addition of the three cytokines together into the cell culture markedly enhanced the CA, to a level higher than that in the AGEs-treated group. In conclusion, our results provide the direct evidence that the cytokines can induce CA, and suggest that there is a mutual promoting cycle between CA and cytokine release in the treated samples. It is proposed that the cycle of CA-cytokine release is a candidate biological link between diabetes and its complications such as vascular pathologies.

The Extracellular Calcium-Sensing Receptor (CASR) Regulates Gonadotropins-Induced Meiotic Maturation of Porcine Oocytes.

Gonadotropins and epidermal growth factor (EGF) play crucial roles in promoting oocyte maturation. The regulatory network downstream of these key factors is not well understood. The present study was designed to investigate the role of the calcium-sensing receptor (CASR) in porcine oocyte in vitro maturation. CASR expression was up-regulated in oocytes matured in gonadotropin-containing medium. Cortical distribution of CASR was enhanced with gonadotropins but not EGF. Supplementation of a CASR agonist (NPS R-568) in the gonadotropin (FSH and/or LH)-containing maturation medium significantly enhanced oocyte nuclear maturation. Addition of NPS2390, a CASR antagonist, compromised oocyte nuclear maturation. Furthermore, increased cortical distribution and decreased expression of CASR was observed after the NPS R-568 treatment. Oocytes treated with NPS R-568 had higher concentration of CYCLIN B1, decreased reactive oxygen species, and increased glutathione levels, indicative of advanced cytoplasmic maturation. In contrast, NPS2390 treatment compromised oocyte cytoplasmic maturation. A higher blastocyst formation rate after parthenogenetic activation was observed when oocytes were matured in the presence of the CASR agonist, NPS R-568. MAPK3/1 phosphorylation was increased during in vitro maturation and after NPS R-568 treatment, and decreased following CASR antagonist supplementation. Taken together, our data showed that the CASR is a gonadotropin-regulated factor that promotes porcine oocyte maturation in a MAPK-dependent manner.

A study on the system of nonaqueous microchip electrophoresis with on-line peroxyoxalate chemiluminescence detection.

This article describes a further development of our previously reported miniaturized analysis system of microchip electrophoresis with on-line chemiluminescence detection. The system, developed first time for nonaqueous microchip electrophoresis with peroxyoxalate chemiluminescence detection, consists of a suction pressure device for sample or reagent introduction, a constant voltage supplied for electrophoretic separation, an either hydrophilic or hydrophobic porous polymer plug for preventing chemiluminescence reagent flowing upstream and a spiral detection channel for enhancement of both detection sensitivity and reproducibility. Especially, by using organic solvent as BGE medium, the developed system avoided the interface problem between aqueous running buffer and low-water-content chemiluminescence solvent in previous reports. The influencing factors on chemiluminescence signal were optimized using rhodamine 6G as model molecule. The system performance was further investigated in the experiment of separation of hydrophilic rhodamine dyes and analysis of hydrophobic polycyclic aromatic hydrocarbon, providing the detection limit (S/N = 3) of 3.5 nmol/L for rhodamine 123, 6.8 nmol/L for rhodamine 6G, and 60 nmol/L for 1-aminopyrene, respectively. The experimental results showed the system offered a number of benefits, including compact structure, high sensitivity, good reproducibility, and a wide range of application prospect.

Artemisinin protects DPSC from hypoxia and TNF-α mediated osteogenesis impairments through CA9 and Wnt signaling pathway.

Dental pulp stem cells (DPSCs) possess the ability of multi-lineage differentiation, and are excellent sources of tissue engineering and regenerative medicine. Oxygen concentration and inflammation are two critical environmental factors that affect the osteogenic differentiation of DPSCs. We aimed to study the role of the antimalarial drug artemisinin on the osteogenic differentiation of human DPSCs under the hypoxia and inflammation conditions. We demonstrated that hypoxia (5% O2) and inflammation (20 ng/mL TNF-α), alone or in combination, significantly diminished in vitro cell survival and increased apoptotic rates. Notably, hypoxia and TNF-α exerted accumulative effect in suppressing the osteogenic differentiation of DPSCs, as evidenced by reduced expression levels of osteogenesis-associated genes including ALP, RUNX2 and OCN in osteogenic condition, as well as reduced mineral nodules formation as indicated by alizarin red staining. Artemisinin at the dose of 40 µM markedly reversed the suppression in cell survival caused by hypoxia or inflammation, and reduced apoptotic rates and the expressions of pro-apoptotic proteins. Additionally, artemisinin restored osteogenic differentiation of DPSCs under the hypoxia or/and inflammation conditions. Moreover, the beneficial effect of artemisinin was dependent on upregulated expression of CA9 and CA9-mediated antioxidant responses, as CA9 knockdown abolished the protective role of artemisinin on DPSC osteogenesis. Furthermore, while hypoxia or/and inflammation significantly inactivated the Wnt/ß-catenin signaling in DPSCs, additional exposure to artemisinin re-activated this pathway to promote osteogenic differentiation of DPSCs. Our results provide novel insight on the link between artemisinin and DPSC osteogenesis, and suggest promising artemisinin-based strategies for better dentin/pulp tissue engineering.

[Preparation of Tea Waste Biochar and Its Application in Tetracycline Removal from Aqueous Solution].

Tea waste biochar (TWBC) was prepared at 300℃, 500℃, and 700℃ under oxygen-limited atmosphere, and was characterized by elemental analysis, Brunauer-Emmett-Teller measurement, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. TWBC was then used to remove tetracycline from aqueous solution. The influences of solid-to-liquid ratio, pH, ionic types, and strength were investigated. The potential mechanism between tetracycline and TWBC was also explored. The results showed that the proper solid-to-liquid ratio was 4 g·L-1. The pH of the solution had little influence on the removal of tetracycline. The inhibition effects of cation ions on tetracycline follows Mg2+ > Ca2+ > K+ > Na+. The NH4+ in the solution can slightly promote the adsorption of tetracycline by TWBC700. However, the existence of Cu can decrease the adsorption effect of tetracycline by TWBC700. Increasing temperature can improve the adsorption effect of tetracycline by TWBC700. The pseudo-second-order and Langmuir model can well fit the adsorption process of tetracycline onto TWBC. The adsorption capacity of tetracycline by TWBC was TWBC700 > TWBC500 > TWBC300. The mechanisms of tetracycline by TWBC referred to the pore-filling effect, hydrogen binding, and π-π interaction. Therefore, high-temperature TWBC has the potential to act as an adsorbent for removing tetracycline from wastewater.

[Activity patterns and foraging behavior of Apis cerana cerana in the urban gardens in winter].

Bees and other pollinating insects are the important parts of biodiversity due to their great role in plant reproduction and crop production. To explore the role of city garden in native bees conservation, activity patterns, visiting behaviors and flowering plants with nectar or pollen were recorded in south Sichuan in winter. The results showed that, worker bees (Apis cerana cerana) were active to collect food out hive under suitable weather conditions, the duration of working was long. Peaks of the number of outgoing, entrance and foragers without pollen appeared at 14:00-15:00, and bimodal patterns were observed. While, peak of bees with pollen appeared at 11:00, and a unimodal pattern was observed. Time significantly affected the activity of workers. The workload of honey bees on nectar and pollen collection were different, just less than twenty percent foragers carrying pollen. Temperature and humidity also affected flights of bees to some degree, and bee activities showed similar patterns on different days. However, the activities had diverse characteristics in some time. Though a less number of plants were in flowering, most of them could be utilized by A. cerana cerana, and colonies could effectively get the food resource by behavior adjustment. In addition, visiting activities of bees on the flowers of main garden plants, such as Camellia japonica, showed obvious rhythm. Increasing the flowering plants with nectar and pollen in winter by scientific management of urban gardens would facilitate the creation of suitable habitats for A. cerana cerana and maintaining the wild population.