Characterization and Proteome of Circulating Extracellular Vesicles as Potential Biomarkers for NASH.

Nonalcoholic fatty liver disease (NAFLD) is currently one of most common forms of chronic liver disease globally. NAFLD represents a wide spectrum of liver involvement from nonprogressive isolated steatosis to nonalcoholic steatohepatitis (NASH), characterized by liver necroinflammation and fibrosis and currently one of the top causes of end-stage liver disease and hepatocellular carcinoma. At present, there is a lack of effective treatments, and a central barrier to the development of therapies is the requirement for an invasive liver biopsy for diagnosis of NASH. Discovery of reliable, noninvasive biomarkers are urgently needed. In this study, we tested whether circulating extracellular vesicles (EVs), cell-derived small membrane-surrounded structures with a rich cargo of bioactive molecules, may serve as reliable noninvasive "liquid biopsies" for NASH diagnosis and assessment of disease severity. Total circulating EVs and hepatocyte-derived EVs were isolated by differential centrifugation and size-exclusion chromatography from serum samples of healthy individuals, patients with precirrhotic NASH, and patients with cirrhotic NASH. EVs were further characterized by flow cytometry, electron microscopy, western blotting, and dynamic light scattering assays before performing a proteomics analysis. Our findings suggest that levels of total and hepatocyte-derived EVs correlate with NASH clinical characteristics and disease severity. Additionally, using proteomics data, we developed understandable, powerful, and unique EV-based proteomic signatures for potential diagnosis of advanced NASH. Conclusion: Our study shows that the quantity and protein constituents of circulating EVs provide strong evidence for EV protein-based liquid biopsies for NAFLD/NASH diagnosis.

Interannual variations in abundance and distribution of Chattonella cysts, and the relationship to population dynamics of vegetative cells in the Yatsushiro Sea, Japan.

The fish-killing raphidophytes Chattonella spp. have a resting cyst stage. To investigate the abundance and distribution of Chattonella cysts and determine their relationship to the population dynamics of vegetative cells, we conducted field observations from 2002 to 2017 in the Yatsushiro Sea, a semi-enclosed embayment in Japan, and analyzed the data including environmental conditions. Analysis of sediment sampled in the spring (mid-April to early June), shows that cysts are relatively abundant in the northern to middle area, where initial vegetative cells and large blooms are frequently detected. The maximum density of cysts was 616 cysts cm-3 in the northern area in 2016. Mean cyst abundance in the spring varied interannually, ranging from 5 to 138 cysts cm-3. A significant positive correlation between mean cyst abundance in the spring and maximum density of vegetative cells the preceding summer was seen, but no significant correlation was observed the following summer. The first detected date of vegetative cells (FDD) each year, which is likely related to cyst abundance and environmental conditions influencing cyst germination and/or growth characteristics of vegetative cells, also varied interannually from mid-April to early June. Regression analyses showed that FDD tended to be early when cyst abundance and bottom-water temperature were high. However, no significant correlation was observed between mean cyst abundance and bloom timing (the period from FDD to the occurrence date of the bloom), and bloom duration the following summer, as was the maximum density of vegetative cells. Instead, the timing and duration of blooms were correlated significantly with meteorological factors (e.g., solar radiation) for a month after FDD. The results suggest that cyst abundance reflecting the bloom magnitude of the preceding summer contributes to the timing of the appearance of vegetative cells in the year, but that bloom occurrence is likely to be controlled by the growth dynamics of vegetative cells through environmental conditions rather than by cyst abundance. The three distinct peaks in Chattonella cysts and vegetative cells from 2002 to 2017 correspond to the timings just after the El Niño. Large-scale atmospheric variability and its global teleconnection are possibly linked to long-term population dynamics of Chattonella in the area through local meteorological conditions and their life cycle.

[Validation study on a method for multiresidue analysis of pesticides in vegetables and fruits with supercritical fluid extraction].

Supercritical fluid extraction (SFE) was applied to extraction of pesticides from vegetables and fruits. Residues were extracted from homogenized samples mixed with water-absorbent polymer with supercritical carbon dioxide in a stainless steel tube, followed by elution with acetone. Co-extractives were removed by means of mini-column clean-up. Measurement was performed by GC-MS/MS. Calibration was achieved by preparing matrix-matched calibration standards to counteract matrix effects. With the Japanese method validation guideline as a reference, the method was assessed in 5 agricultural products spiked with 334 pesticides at 0.01 and 0.1 µg/g. Compounds at each level were extracted from 2 samples on 5 separate days. The trueness of the method for 189 pesticides in all samples was 70-120%, and the repeatability and within-run reproducibility were also consistent with the guideline. The trueness of the method for the other 71 pesticides was in the range of 50-70%, though the repeatability and within-run reproducibility were satisfactory. This method is available as a multiresidue analysis method for vegetables and fruits.

[Validation study of a method for multiresidue analysis of pesticides in cereals and pulses using supercritical fluid extraction].

Supercritical fluid extraction (SFE) was applied to extraction of pesticides from cereals and pulses. Residues were extracted from homogenized samples mixed with water-absorbent polymer and supercritical carbon dioxide in a stainless steel tube, followed by elution with acetonitrile. Co-extractives were removed by means of mini-column clean-up. Measurement was performed by GC-MS/MS. Calibration was achieved by preparing matrix-matched calibration standards to counteract matrix effects. With the Japanese method validation guideline for pesticide residues as a reference, the method was assessed in 5 agricultural products spiked with 334 pesticides at 0.01 and 0.1 µg/g. Compounds at each level were extracted from 2 samples on 5 separate days. The trueness of the method for 137 pesticides in all samples was 70-120%, and the repeatability and within-run reproducibility were also consistent with the guideline. The trueness of the method for the other 101 pesticides was in the range of 50-70%, though the repeatability and within-run reproducibility were satisfactory. This method is available as a multiresidue analysis method for cereals and pulses.