The phosphorylation of hCDC14A modulated by ZIPK regulates autophagy of murine pancreatic islet ß-TC3 cells upon glucose stimulation.

OBJECTIVE: Depletion of islet ß cells plays a crucial role in the onset of diabetes mellitus. Cell autophagy, as a self-healing process, contributes to maintaining metabolic homeostasis and can protect islet ß cells from apoptosis upon starvation or high glucose stress. However, the underlying regulatory network of the autophagic process in islet ß cells has not been fully explored. MATERIALS AND METHODS: Murine ß-TC3 cells treated with different concentrations of glucose, and wild-type or the Ser484 mutant human cell division cycle gene 14A (hCDC14A) was transfected. Cell viability, proliferation and autophagy as well as islet secretion were studied. The mTOR and AMPK signaling pathways were investigated by western blots. Zipper-interacting protein kinase was studied using mass spectrometry and immunoprecipitation. RESULTS: Overexpression of wild-type hCDC14A, but not the Ser484 mutant hCDC14A, promoted cell viability, proliferation and autophagy accompanied by enhanced islet secretion and reduced cell apoptosis via mTOR pathway inhibition as well AMPK pathway activation in ß-TC3 cells and vice versa. Furthermore, Zipper-interacting protein kinase (ZIPK), also known as DAPK3, was found to interact with hCDC14A primarily for Ser484 phosphorylation, and ZIPK knockdown could affect the phosphorylation of hCDC14A and weaken cell death or cell cycle modulation. CONCLUSIONS: Taken together, our results may provide new insight into the role of hCDC14A in the autophagy of islet ß cells and suggest the potential therapeutic value of hCDC14A phosphorylation in the prevention and treatment of diabetes.

First Report of a Fruit Rot and Twig Blight on Pomegranate (Punica granatum) Caused by Pilidiella granati in Anhui Province of China.

Pomegranate, Punica granatum Linn., is widely planted as an ornamental and a fruit crop in Huaiyuan County, Anhui Province, which is the primary pomegranate production area in China. In the early summer of 2012, twig dieback and fruit rot were observed on about 10% and 30% of the pomegranate trees, respectively, in several villages of Huaiyuan County. Necrosis was observed in the twigs, resulting in death of the branches. On fruit, dry rot started at the sepals, covered the entire surface in severely infected fruit, and eventually resulted in shriveling of the fruit. Abundant, black, and solitary pycnidia were observed on diseased twigs and fruit. Pieces of tissue (3 mm in size) from diseased twigs and sepals were surface-disinfected in 75% ethanol for 1 min, washed in sterile water three times, plated on potato dextrose agar (PDA) acidified with 2.5 ml 85% lactic acid per liter, and incubated at 25°C. Resulting fungal cultures produced pale green or white aerial mycelia and sporulated after 5 to 7 days. Pycnidia, ~80 to 130 µm in diameter, were globose and black with thin and membranous walls and contained hyaline, one-celled, and ellipsoid to fusiform conidia, averaging 10.8 to 17.2 × 2.9 to 4.7 µm in size. These morphological features were consistent with Pilidiella granati Sacc. (= Coniella granati Sacc.) (2). Genomic DNA from each of the 10 isolates was extracted and purified using a DNA Gel Extraction Kit (AxyPrep, Hangzhou, China), and PCR was conducted using a DNA Engine System PTC-200 (BIO-RAD, Watertown, MA) with ITS1 and ITS4 internal transcribed spacer universal primers. A single 616-bp fragment was amplified from all 10 isolates and sequenced. Sequence analysis revealed that the ITS from these isolates were identical (100% similarity, GeneBank Accession No. KF560320) to each other and showed >99.5% similarity with those of the P. granti isolates deposited in GenBank (AY339342.1). To evaluate pathogenicity, mycelial plugs (5 mm diameter) from 7-day-old PDA cultures were transferred onto the non-wounded sepals of pomegranate fruit (one plug per fruit, six fruits per isolate), and then all inoculated fruit were placed in plastic bags and maintained at 25°C for 14 days. In addition, twigs on pomegranate plant growing in the field were inoculated by placing mycelial plugs of the fungus on young bark and covered with cotton saturated with sterile water (one plug per twig, six twigs per isolate). Sterile PDA plugs were used as controls in both tests. All 10 isolates colonized the fruit after 5 to 8 days; this was followed by the appearance of dry rot and formation of abundant pycnidia after 10 to 12 days. No decay was observed on the control fruit. Isolates were also pathogenic on twigs, resulting in brown lesions after 2 months that were 2 to 5 cm long. No lesions were observed on the control twigs. Furthermore, the pathogen was isolated from all inoculated fruit and twig tissues and identified to be P. granati as described above, fulfilling Koch's postulates. This pathogen has been reported in Spain (3), Greece (4), and Iran (1), causing crown rot on pomegranate in addition to infecting fruit, but has not been reported previously in Anhui Province of China. This disease is an emerging problem in Anhui Province and will necessitate the development of new disease management practices to sustain commercial production in this region. References: (1) M. Mirabolfathy et al. Plant Dis. 96:461, 2012. (2) Niekerk et al. Mycol. Res. 108:283, 2004. (3) L. Palou et al. New Dis. Rep. 22:21, 2010. (4) T. Thomidis et al. Plant Dis. 95:79, 2011.

A human health risk assessment of mercury species in soil and food around compact fluorescent lamp factories in Zhejiang Province, PR China.

This study investigated total mercury (THg) and methylmercury (MeHg) contamination in a major production center of compact fluorescent lamps (CFLs) located in Gaohong, Zhejiang Province, China. This was a result of the growing concern associated with the release of mercury into the environment from such components. The results of the study included the following mean concentrations for THg and MeHg of 157±11 (61-518)ng/gdw and 0.28±0.07 (0.07-0.67)ng/gdw in agricultural soil, respectively, and 18.6±6.5 (3.2-47.8)ng/gww and 0.11±0.03 (0.02-0.37)ng/gww in vegetable samples, respectively. A significant correlation was observed between THg in vegetables and corresponding soil samples (r=0.64, p<0.01). THg and MeHg in sediment samples had respective concentrations ranging from 28 to 1019ng/gdw and 0.11 to 3.15ng/gdw. Mud skipper bought from the local market contained the highest Hg (THg: 170±45ng/gww, MeHg: 143±37ng/gww) amongst all fish species (THg: 14-170; MeHg: 11-143ng/gww) of the study. The risk assessment indicated that fish consumption should not result in a MeHg EDI exceeding the RfD (0.1µg/kgbw/d) for both adults and children, when MeHg bioaccessibility is taken into account.

Kinetics and thermodynamics of adsorption of ionizable aromatic compounds from aqueous solutions by as-prepared and oxidized multiwalled carbon nanotubes.

The adsorption of 1-naphthylamine, 1-naphthol and phenol on as-prepared and oxidized multiwalled carbon nanotubes (MWCNTs) has been investigated. The results illustrated that both as-prepared and oxidized MWCNTs showed high adsorption capacity for the three ionizable aromatic compounds (IACs) studied. Oxidation of MWCNTs increased the surface area and the pore volume, and introduced oxygen-containing functional groups to the surfaces of MWCNTs, which depressed the adsorption of IACs on MWCNTs. Both Langmuir and Freundlich models described the adsorption isotherms very well and the adsorption thermodynamic parameters (DeltaG degrees, DeltaH degrees and DeltaS degrees) were measured. The adsorption for 1-naphthylamine, 1-naphthol and phenol is general spontaneous and thermodynamically favorable. The adsorption of phenol is an exothermic process, whereas the adsorption of 1-naphthylamine and 1-naphthol is an endothermic process. Results of this work are of great significance for the environmental application of MWCNTs for the removal of IACs from large volume of aqueous solutions.