Club cell secretory protein 16 is a potential biomarker for silica-induced pulmonary fibrosis.

This study was conducted to investigate the changes of Club cell protein 16 (CC16) and surfactant protein D (SP-D) levels in serum and bronchoalveolar lavage fluid (BALF) in silicotic rats and to explore their potential as early biomarkers for silicosis. Pulmonary fibrosis models of rats were constructed by exposing them to silica particles. BALF and serum were collected to determine CC16 and SP-D levels using enzyme-linked immunosorbent assay (ELISA) at different times after the exposure. Hydroxyproline (HYP) level in BALF and CC16 level in the lung tissues were also measured immunohistochemistrially. The BALF levels of CC16 decreased from 49.65 to 38.02 ng/mg after the rats were exposed to silica for 3 and 28 days, which were all significantly lower as compared with the controls (P<0.05), where the levels remained barely changed during the same period (61.27 to 56.76 ng/mg). The serum CC16 also showed a similar decrease from 9.8 ng/ml to 8.78 ng/ml during the period, while in the controls, the serum CC16 levels remained constantly between 11.04 and 10.96 ng/ml. The levels of SP-D in the serum of silica-exposed rats did not decrease as compared with the controls and BALF SP-D presented a parabolic curve change with silica exposure. Immunohistochemical examinations showed that the lung Club cells were severely damaged and CC16 expression was obviously decreased after silica exposure. BALF HYP level was higher in silica-exposed rats than in control only when the exposure was at 50 mg/ml. Our work demonstrates that expressions of CC16 and SP-D are pulmonary tissue-specific and CC16 expression is down-regulated as a result of silica-exposure. The significant relationship between CC16 and silica dose indicates that CC16 may be exploited as an early biomarker to assess silica-induced pulmonary fibrosis.

Identification and Characterization of miRNAs and Their Predicted mRNAs in the Larval Development of Pearl Oyster Pinctada fucata.

As an important economic shellfish, the pearl oyster, Pinctada fucata, and its larvae are an ideal model for studying molecular mechanisms of larval development in invertebrates. Larval development directly affects the quantity and quality of pearl oysters. MicroRNAs (miRNAs) may play important roles in development, but the effects of miRNA expression on P. fucata early development remain unknown. In this study, miRNA and mRNA transcriptomics of seven different P. fucata developmental stages were analyzed using Illumina RNA sequencing. A total of 329 miRNAs, including 87 known miRNAs and 242 novel miRNAs, and 33,550 unigenes, including 26,333 known genes and 7217 predicted new genes, were identified in these stages. A cluster analysis showed that the difference in the numbers of miRNAs was greatest between fertilized eggs and trochophores. In addition, the integrated mRNA transcriptome was used to predict target genes for differentially expressed miRNAs between adjacent developmental stages, and the target genes were subjected to a gene ontology enrichment analysis. Using the gene ontology annotation, 100 different expressed genes and 95 differentially expressed miRNAs were identified as part of larval development regulation. Real-time PCR was used to identify eight mRNAs and three miRNAs related to larval development. The present findings will be helpful for further clarifying the regulatory mechanisms of miRNA in invertebrate larval development.

[Determination of 14 pesticide residues in crucian carp using on-line gel permeation chromatography-multi gas chromatography/mass spectrometry].

A new method was developed for the determination of pesticide residues in crucian carp using on-line gel permeation chromatography-multi gas chromatography/mass spectrometry (GPC-MDGC/MS). The pesticide residues were extracted with cyclohexane-ethyl acetate (1:1, v/v) for twice. After being frozen, the extract was filtered by 0.22 microm member, and then cleaned up and analyzed by online GPC-MDGC/MS. The pesticides were selectively transferred from the 1st column to the 2nd column by means of heart cutting. As a result, selective transfers of some pesticides from the first to the second dimension were at times essential to avoid overlapping. The selected separation conditions from the study with standards were applied to crucian carp spiked with some pesticide standards. The performance of this method was examined by recovery, linearity and precision. Inter-standard quantitative method was used for calculation. Good linear relationship was achieved in the range of 0.01-0.9 mg/L for the 14 pesticides with correlation coefficients above 0.99. The recoveries of the method ranged from 83.0% to 112.9% with the relative standard deviations (RSDs) among 3.2%-12.0% at 3 spiked levels of 0.01, 0.05 and 0.1 mg/kg. This is a simple, rapid method for the analysis of multiple pesticide residues in crucian carp with high accuracy and sensitivity. The results prove that the employment of a multidimensional analysis technique permits to avoid interferences of the analytes with matrix components.

Electrochemistry of hemoglobin entrapped in a Nafion/nano-ZnO film on carbon ionic liquid electrode.

A stable composite film composed of the ionomer Nafion, the ZnO nanoparticle and the protein hemoglobin was cast on the surface of an ionic liquid modified carbon paste electrode (CILE) to establish a modified electrode denoted as Nafion/nano-ZnO/Hb/CILE. UV-vis and FT-IR spectrum showed that hemoglobin in the film retained its native conformation. The electrochemical behaviors of hemoglobin entrapped in the film were carefully investigated with cyclic voltammetry. A pair of well-defined and quasi-reversible redox voltammetric peaks for Hb Fe(III)/Fe(II) was obtained with the standard potential (E(0)') located at -0.344 V (vs. SCE) in phosphate buffer solution (PBS, pH 7.0), which was attributed to the direct electron transfer of Hb with electrode in the microenvironments of ZnO nanoparticle and ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF(6)). The electrochemical parameters of Hb in the composite film were further carefully calculated with the results of the electron-transfer rate constant (k(s)) as 0.139 s(-1), the charge transfer coefficient (alpha) as 0.413 and the number of electron transferred (n) as 0.95. The Hb modified electrode showed good electrocatalytic ability toward the reduction of trichloroacetic acid (TCA).