Developmental transcriptomics throughout the embryonic developmental process of Rhipicephalus turanicus reveals stage-specific gene expression profiles.

BACKGROUND: Ticks are important vectors and transmit diverse pathogens, including protozoa, viruses, and bacteria. Tick-borne diseases can cause damage to both human health and the livestock industries. The control and prevention of ticks and tick-borne diseases has relied heavily on acaricides. METHODS: In the present study, using a high-throughput RNA sequencing (RNA-Seq) technique, we performed a comprehensive time-series transcriptomic analysis throughout the embryogenesis period of Rhipicephalus turanicus. RESULTS: Altogether, 127,157 unigenes were assembled and clustered. Gene expression differences among the embryonic stages demonstrated that the most differentially expressed genes (DEGs) were observed in the comparisons of early embryonic stages (RTE5 vs. RTE10, 9726 genes), and there were far fewer DEGs in later stages (RTE25 vs. RTE30, 2751 genes). Furthermore, 16 distinct gene modules were identified according to weighted gene co-expression network analysis (WGCNA), and genes in different modules displayed stage-specific characteristics. Gene Ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment suggested that some genes involved in organ and tissue formation were significantly upregulated in the early embryonic developmental stages, whereas metabolism-related pathways were more enriched in the later embryonic developmental stages. CONCLUSIONS: These transcriptome studies revealed gene expression profiles at different stages of embryonic development, which would be useful for interrupting the embryonic development of ticks and disrupting the transmission of tick-borne diseases.

Lake warming intensifies the seasonal pattern of internal nutrient cycling in the eutrophic lake and potential impacts on algal blooms.

Lake warming induced by climate change has constituted a particular challenge for the restoration of eutrophic lakes. However, a quantitative analysis about impacts of lake warming on the internal nutrient cycling in eutrophic lakes is limited. In this study, monthly nutrient monitoring data set in 2015-2016 in eutrophic Lake Chaohu, China, revealed a regular seasonal pattern of nutrient concentration. A process-based water quality model was established to quantify contributions from internal loadings on seasonal nutrient variations and predict responses under climate change scenarios. Results indicated that internal nutrient loading was responsible for the intra-annual variations of nutrient concentrations in the lake, and the internal loadings fluctuated much more between different seasons than the external nutrient inputs. We predicted that lake warming might probably result in stronger seasonal fluctuations of internal loading and create conditions beneficial for longer duration of cyanobacteria blooms in the year. Evidence derived from this study could help water managers to rethink the existing mitigation strategies in the restoration of eutrophic lakes and emphasize the potential interactions among lake warming, eutrophication and internal nutrient cycling in the future.

Effect of X-ray irradiation on pharmacokinetics of irinotecan hydrochloride and expression of CES1 and CYP3A1 in rats.

Concurrent chemoradiation with irinotecan hydrochloride (CPT-11) is accepted for cancer treatment. However, the effects of X-ray irradiation on chemotherapeutics in the plasma remain unclear. We evaluated the pharmacokinetics of CPT-11 in rats after exposure to X-ray irradiation and examined the changes of protein and mRNA expression of CES1 and CYP3A1. The X-ray irradiation with 1 Gy and 5 Gy was delivered to the whole body of rats. CPT-11 at 30 and 60 mg/kg, respectively, was intravenously infused 24 h after irradiation. CPT-11 was determined by RP-HPLC in plasma. ELISA and PCR were used to analyze the protein and mRNA expression of CES1 and CYP3A1, respectively. Compared with control rats, the X-ray irradiation decreased the AUC of CPT-11 (30 mg/kg) by 15.6% at 1 Gy and 39.0% at 5 Gy and increased the CL by 60.0% at 5 Gy. The X-ray irradiation could also decrease the AUC of CPT-11 (60 mg/kg) and increase the CL. In addition, the protein and mRNA expression of CES1 and CYP3A1 were increased significantly in rats after irradiation. This study found significant changes in the pharmacokinetics of CPT-11 in rats after exposure to X-ray irradiation, and they might be due to significant increases in the expressions of CYP3A1 and CES1. The pharmacokinetics of CPT-11 should be rechecked, and the optimal CPT-11 dose should be reevaluated during concurrent chemoradiation therapy.

Molecular analysis and genetic diversity of Aedes albopictus (Diptera, Culicidae) from China.

Aedes albopictus is one of the most invasive species, which can carry Dengue virus, Yellow fever virus and more than twenty arboviruses. Based on mitochondrial gene cytochrome c oxidase I (COI) and samples collected from 17 populations, we investigated the molecular character and genetic diversity of Ae. albopictus from China. Altogether, 25 haplotypes were detected, including 10 shared haplotypes and 15 private haplotypes. H1 was the dominant haplotype, which is widely distributed in 13 populations. Tajima'D value of most populations was significantly negative, demonstrating that populations experienced rapid range expansion recently. Most haplotypes clustered together both in phylogenetic and median-joining network analysis without clear phylogeographic patterns. However, neutrality tests revealed shallow divergences among Hainan and Guangxi with other populations (0.15599 ≤ FST ≤ 0.75858), which probably due to interrupted gene flow, caused by geographical isolations. In conclusion, Ae. albopictus populations showed low genetic diversity in China.

Emission factors, size distributions, and emission inventories of carbonaceous particulate matter from residential wood combustion in rural China.

Published emission factors (EFs) often vary significantly, leading to high uncertainties in emission estimations. There are few reliable EFs from field measurements of residential wood combustion in China. In this study, 17 wood fuels and one bamboo were combusted in a typical residential stove in rural China to measure realistic EFs of particulate matter (PM), organic carbon (OC), and elemental carbon (EC), as well as to investigate the influence of fuel properties and combustion conditions on the EFs. Measured EFs of PM, OC, and EC (EF(PM), EF(OC), and EF(EC), respectively) were in the range of 0.38-6.4, 0.024-3.0, and 0.039-3.9 g/kg (dry basis), with means and standard derivation of 2.2 ± 1.2, 0.62 ± 0.64, and 0.83 ± 0.69 g/kg, respectively. Shrubby biomass combustion produced higher EFs than tree woods, and both species had lower EFs than those of indoor crop residue burning (p < 0.05). Significant correlations between EF(PM), EF(OC), and EF(EC) were expected. By using a nine-stage cascade impactor, it was shown that size distributions of PM emitted from tree biomass combustions were unimodal with peaks at a diameter less than 0.4 µm (PM(0.4)), much finer than the PM from indoor crop residue burning. Approximately 79.4% of the total PM from tree wood combustion was PM with a diameter less than 2.1 µm (PM(2.1)). PM size distributions for shrubby biomasses were slightly different from those for tree fuels. On the basis of the measured EFs, total emissions of PM, OC, and EC from residential wood combustion in rural China in 2007 were estimated at about 303, 75.7, and 92.0 Gg.

Study on preparation and unique properties of a novel insulin analogue with N-terminal Arg-4, Pro-3, Lys-2, Pro-1extension at insulin B-chain.

A novel insulin analog, PIns, with N-terminal Arg-4, Pro-3, Lys-2, Pro-1extension at human regular insulin B-chain was acquired through gene engineering. Preproinsulin for PIns was cloned and expressed using a bacterial expression system at a high level (72.1%) as fusion protein carrying a modified thioredoxin N-terminal region (1-21) linked to N-terminus of proinsulin by a lysine residue. Purified fusion protein was refolded and converted into PIns by a single enzymatic reaction. After PIns was purified, the homogeneity of it was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis, isoelectronic focusing electrophoresis, amino acid composition analysis and mass spectrometry methods. A decreased tendency of self-association of PIns as compared with regular insulin was demonstrated by the size exclusion HPLC analysis. When subcutaneously administrated into normal rats, the PIns showed a faster rate of onset of action and a shorter duration of action compared with regular insulin, similar to the pharmacokinetic characteristics of insulin Lispro. These results showed that PIns is a rapid insulin analog. Furthermore, the N-terminal Arg-4, Pro-3, Lys-2, Pro-1extension at insulin B-chain can be excised by DPPIV and recombinant peptidase with DPPIV-like activities. It is suggested that PIns serves as an artificial insulin precursor and can be transformed to regular insulin in vivo due to the truncation of N-terminal sequence of PIns B-chain by DPPIV.

Study on preparation and activity of a novel recombinant human parathyroid hormone(1-34) analog with N-terminal Pro-Pro extension.

A recombinant human parathyroid hormone fragment, Pro-Pro-hPTH(1-34), with molecular weight of 4311.46 was acquired through gene engineering. It was then isolated and purified. The homogeneity of this fragment was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), high performance liquid chromatography(HPLC), isoelectronic focusing (IEF) electrophoresis and mass spectrometry(MS) methods. Its isoelectric point is 8.0 which was determined by IEF. It was found that the hormone fragment significantly induced calcium increment as compared to the control group (P<0.001) in Parsons's Chicken Assay, an established bioassay for the evaluation of the PTH effect. After the 3-month-old ovariectomized (OVXed) rats, the OVXed rat is one of the two models required by the U.S. Food and Drug Administration for the preclinical assessment of drugs for treating osteoporosis [DeLuca PP, Dani BA. Skeletal effects of parathyroid hormone (1-34) in ovariectomized rats with or without concurrent administration of salmon calcitonin. Am Assoc Pharm Sci 2001;3(4):E27 [1]]. Sprague-Dawley rats were fed for 14 weeks, daily subcutaneous injections of Pro-Pro-hPTH(1-34) for 16 weeks (0.4, 0.6 or 0.9 nmol/100 g body weight), reduced the ovariectomy (OVX)-triggered mass loss of vertebral trabecular bone. The mean Bone Material Density (BMD) increased to 29.2-34.5% in 3-month-old OVXed rats compared to control-vehicle group (P<0.001) and increased to 17.5-22.3% compared to sham-operated groups (P<0.01). In short, A recombinant Pro-Pro-hPTH(1-34) was harvested in purified form and its physico-chemical characterization was determined. It showed significantly enhanced activity upon two typical models for PTH fragments. It can increase the mineral density of vertebral trabecular bone just as synthetic hPTH(1-34), and the functional activity of Pro-Pro-hPTH(1-34) should be due to the removing of Pro-Pro- by Dipeptidyl peptidase IV (DPPIV). This study opened out a simplified method which was cheaper, faster than the conventional one for producing active hPTH fragment, and its applied prospect would be good; Furthermore, it may open up our own path in finding new methods for post-processing of gene-engineering product.

Asparaginase display of human cholesteryl ester transfer protein (CETP) B cell epitopes for inducing high titers of anti-CETP antibodies in vivo.

The recombinant chimeric enzyme, AnsB-TTP-CETPC, comprising asparaginase, tetanus toxin helper T cell epitope and human CETP B cell epitope was expressed as a soluble protein in Escherichia coli. The purified chimeric enzyme exhibited approximate 83% activity of the native asparaginase. After immunization with three doses of chimeric enzyme, high titers of anti-CETP antibodies were induced and lasted more than eighteen weeks in mice, and could even be detected at a dilution of 1:12800 by normal ELISA assay. The specificity of anti-CETP antibody was verified by Western blot assay. After displaying on the surface of asparaginase, the weak antigenicity of CETP epitope was effectively overcome, there after a strong CETP-specific immune response was evoked in mice immunized with the chimeric enzyme. Histochemical analysis of mice kidney tissue showed that immunization with the chimeric enzyme did not cause any pathological changes in mice. Collectively, the chimeric enzyme may be further developed as a vaccine against atherosclerosis in the future.