Effects of 4A Zeolite Additions on the Structure and Performance of LDPE Blend Microfiltration Membrane through Thermally Induced Phase Separation Method

Microfiltration membranes, 4A zeolite/LDPE, were prepared by blending low density polyethylene (LDPE) and4A zeolite through thermally induced phase separation (TIPS) process with diphenyl ether (DPE) as diluent. The effects of 4A zeolite loading on the pore structure and water permeation performance of the 4A zeolite/LDPE blend membranes were investigated. The incorporation of 4A zeolite particles greatly enhanced the connectivity of membrane pores, the pore size, and thus the water flux of 4A zeolite/LDPE blend membranes due to the gradually stronger DPE-zeolite affinity with the increase of the 4A zeolite loading. The water flux increased from 0 of LDPE control membrane to 87 L/m2h of 4A zeolite/LDPE blend membrane with 4A zeolite loading of 10 wt%. In addition, increasing the DPE content and cooling bath temperature is in favor of the water flux of 4A zeolite/LDPE blend membranes

The Significance of the Bifunctional Kinase/Phosphatase Activities of Diphosphoinositol Pentakisphosphate Kinases (PPIP5Ks) for Coupling Inositol Pyrophosphate Cell Signaling to Cellular Phosphate Homeostasis

Proteins responsible for Pi homeostasis are critical for all life. In Saccharomyces cerevisiae, extracellular [Pi] is “sensed” by the inositol-hexakisphosphate kinase (IP6K) that synthesizes the intracellular inositol pyrophosphate 5-diphosphoinositol 1,2,3,4,6-pentakisphosphate (5-InsP7) as follows: during a period of Pi starvation, there is a decline in cellular [ATP]; the unusually low affinity of IP6Ks for ATP compels 5-InsP7 levels to fall in parallel (Azevedo, C., and Saiardi, A. (2017) Trends. Biochem. Sci. 42, 219–231. Hitherto, such Pi sensing has not been documented in metazoans. Here, using a human intestinal epithelial cell line (HCT116), we show that levels of both 5-InsP7 and ATP decrease upon [Pi] starvation and subsequently recover during Pi replenishment. However, a separate inositol pyrophosphate, 1,5-bisdiphosphoinositol 2,3,4,6-tetrakisphosphate (InsP8), reacts more dramatically (i.e. with a wider dynamic range and greater sensitivity). To understand this novel InsP8 response, we characterized kinetic properties of the bifunctional 5-InsP7 kinase/InsP8 phosphatase activities of full-length diphosphoinositol pentakisphosphate kinases (PPIP5Ks). These data fulfil previously published criteria for any bifunctional kinase/phosphatase to exhibit concentration robustness, permitting levels of the kinase product (InsP8 in this case) to fluctuate independently of varying precursor (i.e. 5-InsP7) pool size. Moreover, we report that InsP8 phosphatase activities of PPIP5Ks are strongly inhibited by Pi (40–90% within the 0–1 mm range). For PPIP5K2, Pi sensing by InsP8 is amplified by a 2-fold activation of 5-InsP7 kinase activity by Pi within the 0–5 mm range. Overall, our data reveal mechanisms that can contribute to specificity in inositol pyrophosphate signaling, regulating InsP8 turnover independently of 5-InsP7, in response to fluctuations in extracellular supply of a key nutrient

Serum N‐glycans outperform CA19‐9 in diagnosis of extrahepatic cholangiocarcinoma

Extensive efforts have been devoted to improve the diagnosis of extrahepatic cholangiocarcinoma (ECCA) due to its silent clinical character and lack of effective diagnostic biomarkers. Specific alterations in N‐glycosylation of glycoproteins are considered a key component in cancer progression, which can serve as a distinct molecular signature for cancer detection. This study aims to find potential serum N‐glycan markers for ECCA. In total, 255 serum samples from patients with ECCA (n = 106), benign bile tract disease (BBD, n = 60) and healthy controls (HC, n = 89) were recruited. Only 2 μL of serum from individual patients was used in this assay where the N‐glycome of serum glycoproteins was profiled by DNA sequencer‐assisted fluorophore‐assisted capillary electrophoresis (DSA‐FACE) technology. Multi‐parameter models were constructed by combining the N‐glycans and carbohydrate antigen 19‐9 (CA19‐9) which is currently used clinically. Quantitative analyses showed that among 13 N‐glycan structures, the bifucosylated triantennary N‐glycan (peak10, NA3F2) presented the best diagnostic performance for distinguishing ECCA from BBD and HC. Two diagnostic models (Glycotest1 and Glycotest2) performed better than single N‐glycan or CA19‐9. Additionally, two N‐glycan structures (peak9, NA3Fb; peak12, NA4Fb) were tightly related to lymph node metastasis in ECCA patients. In conclusion, sera of ECCA showed relatively specific N‐glycome profiling patterns. Serum N‐glycan markers and models are novel, valuable and noninvasive alternatives in ECCA diagnosis and progression monitoring.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139072/1/elps6272.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139072/2/elps6272_am.pd

ZSM-5 Filled Polyether Block Amide Membranes for Separating EA from Aqueous Solution by Pervaporation

ZSM-5 filled polyether block amide membranes (PEBA), PEBA/ZSM-5, were prepared and used to recover aroma, ethyl acetate (EA), from aqueous solution by pervaporation (PV). The membranes demonstrated high EA permselectivity, and with the increase of ZSM-5 loading, the separation factor increased initially and then decreased, while the total flux demonstrated the similar variation until the ZSM-5 loading was 10 wt%, at which it reached the lowest value. After that, it began to increase again. On the other hand, the separation factor, and total flux of the PEBA/ZSM-5 membrane containing 10 wt% ZSM-5, PEBA/ZSM-5-10, increased with the increase of feed concentration and temperature. The best PV performance, separation factor and total flux of PEBA/ZSM-5-10 membrane were 185.5 and 199.5 gm−2h−1, respectively, with feed concentration of 5 wt% EA at 50°C

Bacillus anthracis Spore Entry into Epithelial Cells Is an Actin-Dependent Process Requiring c-Src and PI3K

Dissemination of Bacillus anthracis from the respiratory mucosa is a critical step in the establishment of inhalational anthrax. Recent in vitro and in vivo studies indicated that this organism was able to penetrate the lung epithelium by directly entering into epithelial cells of the lung; however the molecular details of B. anthracis breaching the epithelium were lacking. Here, using a combination of pharmacological inhibitors, dominant negative mutants, and colocalization experiments, we demonstrated that internalization of spores by epithelial cells was actin-dependent and was mediated by the Rho-family GTPase Cdc42 but not RhoA or Rac1. Phosphatidylinositol 3-kinase (PI3K) activity was also required as indicated by the inhibitory effects of PI3K inhibitors, wortmannin and LY294002, and a PI3K dominant negative (DN) mutant Δp85α. In addition, spore entry into epithelial cells (but not into macrophages) required the activity of Src as indicated by the inhibitory effect of Src family kinase (SFK) inhibitors, PP2 and SU6656, and specific siRNA knockdown of Src. Enrichment of PI3K and F-actin around spore attachment sites was observed and was significantly reduced by treatment with SFK and PI3K inhibitors, respectively. Moreover, B. anthracis translocation through cultured lung epithelial cells was significantly impaired by SFK inhibitors, suggesting that this signaling pathway is important for bacterial dissemination. The effect of the inhibitor on dissemination in vivo was then evaluated. SU6656 treatment of mice significantly reduced B. anthracis dissemination from the lung to distal organs and prolonged the median survival time of mice compared to the untreated control group. Together these results described a signaling pathway specifically required for spore entry into epithelial cells and provided evidence suggesting that this pathway is important for dissemination and virulence in vivo

PPIP5K2 and PCSK1 are Candidate Genetic Contributors to Familial Keratoconus

Keratoconus (KC) is the most common corneal ectatic disorder affecting >300,000 people in the US. KC normally has its onset in adolescence, progressively worsening through the third to fourth decades of life. KC patients report significant impaired vision-related quality of life. Genetic factors play an important role in KC pathogenesis. To identify novel genes in familial KC patients, we performed whole exome and genome sequencing in a four-generation family. We identified potential variants in the PPIP5K2 and PCSK1 genes. Using in vitro cellular model and in vivo gene-trap mouse model, we found critical evidence to support the role of PPIP5K2 in normal corneal function and KC pathogenesis. The gene-trap mouse showed irregular corneal surfaces and pathological corneal thinning resembling KC. For the first time, we have integrated corneal tomography and pachymetry mapping into characterization of mouse corneal phenotypes which could be widely implemented in basic and translational research for KC diagnosis and therapy in the future