UNASSIGNED: Aedes spp. are the most prolific mosquito vectors in the world. Found on every continent, they can effectively transmit various arboviruses, including the dengue virus which continues to cause outbreaks worldwide and is spreading into previously non-endemic areas. The lack of widely available dengue vaccines accentuates the importance of targeted vector control strategies to reduce the dengue burden. High-throughput tools to estimate human-mosquito contact and evaluate vector control interventions are lacking. We propose a novel serological tool that allows rapid screening of human cohorts for exposure to potentially infectious mosquitoes.
UNASSIGNED: We tested 563 serum samples from a longitudinal pediatric cohort study previously conducted in Cambodia. Children enrolled in the study were dengue-naive at baseline and were followed biannually for dengue incidence for two years. We used Western blotting and enzyme-linked immunosorbent assays to identify immunogenic Aedes aegypti salivary proteins and measure total anti-Ae. aegypti IgG.
UNASSIGNED: We found a correlation (rs=0.86) between IgG responses against AeD7L1 and AeD7L2 recombinant proteins and those to whole salivary gland homogenate. We observed seasonal fluctuations of AeD7L1+2 IgG responses and no cross-reactivity with Culex quinquefasciatus and Anopheles dirus mosquitoes. The baseline median AeD7L1+2 IgG responses for young children were higher in those who developed asymptomatic versus symptomatic dengue.
UNASSIGNED: The IgG response against AeD7L1+2 recombinant proteins is a highly sensitive and Aedes specific marker of human exposure to Aedes bites that can facilitate standardization of future serosurveys and epidemiological studies by its ability to provide a robust estimation of human-mosquito contact in a high-throughput fashion.

In the human body, proteins secreted into peripheral blood vessels are known as the secretome, and they represent the physiological or pathological status of cells. The unique response of cells to toxin exposure can be confirmed via secretome analysis, which can be used to discover toxic mechanisms or exposure markers. Alpha-amanitin (α-AMA) is the most widely studied amatoxin and inhibits transcription and protein synthesis by directly interacting with RNA polymerase II. However, secretory proteins released during hepatic failure caused by α-AMA have not been fully characterized. In this study, we analyzed the secretome of α-AMA-treated Huh-7 cells and mice using a comparative proteomics technique. Overall, 1440 and 208 proteins were quantified in cell media and mouse serum, respectively. Based on the bioinformatics results for the commonly downregulated proteins in cell media and mouse serum, we identified complement component 3 (C3) as a marker for α-AMA-induced hepatotoxicity. Through western blot in cell secretome and C3 ELISA assays in mouse serum, we validated α-AMA-induced downregulation of C3. In conclusion, using comparative proteomics and molecular biology techniques, we found that α-AMA-induced hepatotoxicity reduced C3 levels in the secretome. We expect that this study will aid in identifying new toxic mechanisms, therapeutic targets, and exposure markers of α-AMA-induced hepatotoxicity.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s43188-022-00163-z.

Urine and hair are used for assessing human exposure to toxicants. Urine tests can show acute toxicant exposure. Hair analysis can be used to determine chronic toxicant exposure after months to years; however, compared to urine, hair analysis in exposure assessments is much less frequently investigated. Urine and hair are different matrices, and their mechanisms of toxicant metabolite incorporation are different. The toxicant metabolites present in urine and hair may also be different. To clarify this issue, a procedure was developed to identify toxicant metabolites in rat samples using a mass spectrometry-based metabolomic data processing method. Di-(2-propylheptyl) phthalate (DPHP), an industrial plasticizer, was used as the model toxicant. The developed procedure identified not only known DPHP metabolites (mono-(propyl-6-oxo-heptyl) phthalate, mono-(propyl-6-hydroxyheptyl) phthalate, and mono-(propyl-6-carboxyhexyl) phthalate) but also novel metabolites that were structurally related to DPHP in the rat samples, indicating that the developed procedure successfully identified toxicant metabolites in in vivo samples. Among the 62 tentative metabolites identified from the 7th-day urine and the 28th-day hair samples, 33 were detected in only the urine samples, 19 were detected in only the hair samples, and 10 were identified in both the urine and hair samples. A total of 15 out of the 62 metabolites were confirmed as DPHP structure-related metabolites based on MS/MS analysis. Among the 15 DPHP structure-related metabolites, only 2 metabolites were present in both the urine and hair samples. These results suggested that the metabolites identified in urine could not be applied to exposure assessments based on hair analysis.

Knowledge on the influence of current diet on trimethylamine-N-oxide (TMAO) levels in humans is still inconsistent. Thus, we aimed to investigate associations of current diet with urine and plasma TMAO levels and to determine the effect of different foods on TMAO variation.
TMAO concentrations of 297 healthy individuals were assessed using 1 H-NMR spectroscopy for 24 h urine collection and spot urine, and LC-MS for plasma. Of 35 assessed food groups, those with a correlation of ρ >|0.15| with plasma or urine TMAO levels were further investigated in multivariate linear regression models showing current fish and (red) meat consumption as plausible dietary sources of TMAO. Overall, explained variance of TMAO levels by current diet and co-variables (age, sex, lean body mass, glomerular filtration rate) was small. Associations with urine and plasma concentrations differed depending on the TMAO source. Fish consumption was associated with urine and plasma TMAO concentrations, whereas meat consumption was only associated with TMAO concentrations in plasma. Furthermore, associations of plasma TMAO concentration with fish consumption were two times stronger than with meat consumption.
Meat and fish consumption differentially affects TMAO concentrations in body fluids. Only a small fraction of variance is explained by current diet.

The Great East Japan Earthquake on March 11, 2011 caused severe damage to the Sanriku coastal area, where we have been conducting a birth cohort study. The disaster occurred in the middle of 7-year-old examination. The mother-child pairs who participated in our study were compulsorily divided into two groups: the examination was finished for 157 children before the disaster, and for 335 after the disaster. We examined whether the disaster affected total mercury (THg) levels of the cohort, as well as a relationship between the THg levels at birth and at present. Although there was no significant difference between the predisaster and postdisaster groups for THg levels in cord blood (16.3 and 16.1ngg-1, respectively) or maternal hair at parturition (2.57 and 2.55μgg-1, respectively), the THg in hair of the 7-year-old children was significantly lower in the postdisaster group (1.79μgg-1) than in the predisaster group (2.51μgg-1). The difference remained significant after adjusting for the prenatal exposure level of THg. In the 492 mother-child pairs, the cord-blood THg was significantly correlated with the THg in maternal hair at parturition (r=0.846) and in hair of the 7-year-old children (r=0.147). In conclusion, the 29% decrease in hair THg after the disaster appears to have been due to the fact that children in the affected area could not consume fish/seafood as usual, probably because of destructive damage to the fishery. Nevertheless, the THg levels at 7years of age reflected the prenatal exposure levels to some extent.

A variety of exposure regimens of cigarette smoke have been used in animal models of lung diseases. In this study, we compared biological responses of smoke exposure in rats, using different smoke concentrations (wet total particulate matter [WTPM]), daily exposure durations, and total days of exposure. As a range-finding acute study, we first compared pulmonary responses between SD and F344 strains after a single nose-only exposure to mainstream cigarette smoke or LPS. Secondly, F344 rats were exposed to cigarette smoke for 2 or 13 weeks under the comparable daily exposure dose (WTPM concentration x daily exposure duration; according to Haber\'s rule) but at a different WTPM concentration or daily exposure duration. Blood carboxylhemoglobin was increased linearly to the WTPM concentration, while urinary nicotine plus cotinine value was higher for the longer daily exposure than the corresponding shorter exposure groups. Gamma glutamyl transferase activity in bronchoalveolar lavage fluid (BALF) was increased dose dependently after 2 and 13 weeks of cigarette smoke exposure, while the neutrophil content in BALF was not increased notably. Smoke-exposed groups showed reduced body weight gain and increased relative lung and heart weights. While BALF parameters and the relative lung weights suggest pulmonary responses, histopathological examination showed epithelial lesions mainly in the upper respiratory organs (nose and larynx). Collectively, the results indicate that, under the employed study design, the equivalent daily exposure dose (exposure concentration x duration) induces equivalent pulmonary responses in rats.