Establishment and evaluation of targeted molecular screening model for the ryanodine receptor or sarco/endoplasmic reticulum calcium ATPase.

BACKGROUD: Endoplasmic reticulum/sarcoplasmic reticulum (ER/SR) is crucial for maintaining intracellular calcium homeostasis due to the calcium-signaling-related proteins on its membrane. While ryanodine receptors (RyR) on insect ER/SR membranes are well-known as targets for diamide insecticides, little is known about other calcium channels. Given the resistance of diamide insecticides, the establishment of molecular screening models targeting RyR or sarco/endoplasmic reticulum calcium ATPase (SERCA) is conducive to the discovery of new insecticidal molecules. RESULTS: The morphological features of Mythimna separata SR have closed vesicles with integrity and high density. The 282 proteins in the SR component contained RyR and SERCA. A measurement model for the release and uptake of calcium was successfully established by detecting calcium ions outside the SR membrane using a fluorescence spectrophotometer. In vitro testing systems using SR vesicles found that diamide insecticides could activate dose-dependently RyR, with EC50 values of 0.14 µM (Chlorantraniliprole), 0.21 µM (Flubendiamide), and 0.57 µM (Cyantraniliprole), respectively. However, dantrolene inhibited RyR-mediated calcium release with an IC50 value of 353.9 µM, suggesting that dantrolene can weakly antagonize RyR. Moreover, cyclopiazonic acid significantly reduced the enzyme activity and calcium uptake capacity of SERCA. On the contrary, CDN1163 markedly activated the enzyme activity and improved the calcium transport capacity of SERCA. CONCLUSIONS: SR vesicles can be used to study the function of unknown proteins on the SR membranes, as well as for high-throughput screening of highly active compounds targeting RyR or SERCA. © 2024 Society of Chemical Industry.

[Correlations between HBCD and thyroid hormone concentrations in human serum from production source area].

The levels of hexabromocyclododecane (HBCD) in human serum from the HBCD production source region were detected by UPLC-ESI-MS/MS. The concentrations (lipid weight) of ∑ HBCD in 80 serum samples ranged from not detectable to 2702.5 ng · g(-1). The mean and median values were 104.9 ng · g(-1) and 5.9 ng · g(-1), respectively. The most abundant HBCD isomer in 42 samples was γ-HBCD, while α-HBCD was the most abundant isomer in the other 26 serum samples. There was no significant difference in ∑ HBCD concentration among different age and gender. In this study, the thyroid hormone abnormality rate in the 80 residents was up to 33%. The thyroid hormone abnormality rate of the residents whose serum HBCD was detected was significantly higher than those without HBCD in serum. Since the local residents were highly exposed to HBCD, the probability of thyroid abnormality might be significantly increased.

Polybrominated diphenyl ethers exposure in breast milk in Shanghai, China: levels, influencing factors and potential health risk for infants.

The use of polybrominated diphenyl ethers (PBDEs) is increasing annually in China. Although several studies have reported significant contamination by these compounds in biological samples in China, little is known about the factors that may influence the levels of exposure and the potential health risk for infants. We investigated PBDE exposure levels in breast milk, its influencing factors and the potential health risk for infants in Shanghai, China by enrolling 48 healthy women between September 2006 and April 2007. PBDE exposure was assessed by analyses of seven PBDE congeners in breast milk. The estimated daily intake of PBDEs by infants via breastfeeding was determined for evaluating the potential health risk for infants. The median (range) of total PBDE content in breast milk was 8.81 (1.92-41.55) ng/g lipid. 34 (71%) of the 48 samples tested positive for all seven congeners. Maternal education level and household monthly salary were positively associated with PBDE concentration in breast milk (r=0.337, p=0.019 and r=0.436, p=0.004, respectively). The median of estimated daily intake of BDE-99 (6.67 ng/kg/day) by infants via breastfeeding was below the human no adverse effect level (NAEL) set for BDE-99 for neurodevelopmental toxicity (18.8 ng/kg/day). However, 3 (6%) of the samples exceeded the human NAEL. Taking the high detection rate of PBDEs in breast milk together with 6% of their EDI higher than NAEL in Shanghai, more studies on the effects of maternal PBDE exposure on fetal growth and child neurodevelopment are warranted.

[Concentration of polybrominated diphenyl ethers in umbilical cord serum and the influence on newborns birth outcomes in Shanghai].

OBJECTIVE: To explore the concentration of polybrominated diphenyl ethers (PBDEs) in umbilical cord serum and analyze the influence of exposure to PBDEs during fetal stage on newborn birth outcomes in Shanghai. METHODS: Fifty delivery women in a Shanghai hospital were surveyed by questionnaire, and the umbilical cord serum were collected from September 2006 to April 2007. All the delivery women were singleton pregnancies, excluding high blood pressure, diabetes, HIV infection and adverse medical history. Seven congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and BDE-183) were measured by gas chromatography-negative chemical ionization-mass spectrometry and the influencing factors were analyzed. RESULTS: Newborns' length, weight, chest circumference, head circumference and body mass index (BMI) were (50.15 ± 0.75) cm, (3.49 ± 0.42) kg, (34.76 ± 1.51) cm, (35.03 ± 1.40) cm, (13.76 ± 1.36) kg/m(2), respectively. The median of Σ(7PBDEs) concentration in umbilical cord serum was 14.06 (1.03 - 379.73) ng/g lipid weight (lw). The detection rate of BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and BDE-183 were 22% (11/50), 22% (11/50), 98% (49/50), 72% (36/50), 76% (38/50), 90% (45/50) and 14% (7/50), respectively. The median (range) of PBDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183) congeners were < LOD (< LOD-137.20 ng/g lw), < LOD (< LOD-33.17 ng/g lw), 7.54 ng/g lw (< LOD-94.01 ng/g lw), 1.57 ng/g lw (< LOD-46.95 ng/g lw), 0.63 ng/g lw (< LOD-79.08 ng/g lw), 0.63 ng/g lw (< LOD-22.30 ng/g lw) and < LOD (< LOD-21.63 ng/g lw), respectively. The newborns' BMI showed a negative correlation with BDE-99 (r = -0.347, P < 0.05) and BDE-154 (r = -0.292, P < 0.05). BDE-99 in low-length group (≤ 50 cm, 10.59 ng/g lw) was significantly higher (t = 2.32, P = 0.03) than that in high-length group (> 50 cm, 3.60 ng/g lw). CONCLUSION: PBDEs were commonly detected in newborns' umbilical cord serum in this study. Our findings indicated that exposure to PBDEs adversely affected the development of the newborns.

[Levels of polybrominated diphenyl ethers in human breast milk from a hospital in Shanghai].

OBJECTIVE: To measure the concentration of polybrominated diphenyl ethers (PBDEs) in human breast milk from a hospital in Shanghai and analyze the influencing factors. METHODS: Forty-eight puerperal from a hospital in Shanghai were selected to answer a questionnaire, and their breast milk samples were collected from September 2006 to April 2007. All the puerperal were singleton pregnancies, excluding high blood pressure, diabetes, HIV infection and adverse medical history. Seven congeners (BDE-28, BDE-47, BDE-100, BDE-99, BDE-154, BDE-153 and BDE-183) were measured by gas chromatography-negative chemical ionization-mass spectrometry and the influencing factors were analyzed. RESULTS: The median of total PBDEs concentration in breast milk was 8.81 ng/g lipid weight (lw), and the range was 1.92 - 41.55 ng/g lw. The detection rates of seven congeners (BDE-28, BDE-47, BDE-100, BDE-99, BDE-154, BDE-153, BDE-183) were 98% (47/48), 96% (46/48), 86% (41/48), 90% (43/48), 83% (40/48), 98% (47/48), 90% (43/48), and the median of them was 0.88, 0.99, 0.97, 1.39, 1.14, 2.17, 1.41 ng/g lw, respectively. LogΣ(7PBDEs) in breast milk from mothers with different education levels were divided into junior high school or lower (0.89 ± 0.24), senior high school (1.02 ± 0.17), junior college or higher (1.08 ± 0.28). LogΣ(7PBDEs) in breast milk from mothers with different income levels were divided as < 1000 yuan (0.89 ± 0.12), 1000 - 3000 yuan (1.01 ± 0.24), > 3000 yuan (1.13 ± 0.21). Correlation analysis showed that both the mothers' education level (r = 0.322, P < 0.05) and income level (r = 0.388, P < 0.05) have a positive correlation to PBDEs levels in breast milk. CONCLUSION: It is very common to detect PBDEs in human breast milk, however, the education and income levels of the mothers may be the influencing factors.

[Levels of hexabromocyclododecane in human breast milk and the daily intake of newborns in a Shanghai hospital].

OBJECTIVE: To explore the level of hexabromocyclododecane (HBCD) in human breast milk of delivery women in a Shanghai hospital, and estimate the daily intake of newborns from breast milk. METHODS: Forty-eight delivery women in a Shanghai suburb hospital (Class A, Grade 3) were surveyed by questionnaires, and their breast milk samples were collected from September 2006 to April 2007. All the delivery women were singleton pregnancies, excluding high blood pressure, diabetes, HIV infection and adverse medical history. Three diastereoisomers (α-HBCD, ß-HBCD, γ-HBCD) were measured by the liquid chromatography-electrospray ion source-tandem mass spectrometry, and then estimated the daily intake of the newborns from the breast milk. RESULTS: The total HBCD concentration of breast milk, which was detected in 79% (38/48) of samples, ranged from 0.11 ng/g lipid weight (lw) to 37.75 ng/g lw, with the median at 1.42 ng/g lw. The most abundant diastereoisomer was α-HBCD which detected in 77% (37/48) of samples, with a median of 1.24 ng/g lw; followed by γ-HBCD and ß-HBCD, detected in 13% (6/48) and 17% (8/48) of samples respectively, whose median were both under the limit of detection (LOD). The daily intake of the newborns from the breast milk ranged from 0.71 ng/kg to 243.46 ng/kg. CONCLUSION: The concentrations of HBCD in breast milk of delivery women in a Shanghai hospital have been in a high level, and the influence on newborns' health need to be further studied.

[Correlations between PBDEs and thyroid hormone concentrations in adults from production source area].

Polybrominated diphenyl ethers (PBDEs) concentrations in 36 resident serum samples from PBDEs production source area were analyzed by gas chromatography/negative chemical ionization/mass spectrometry(GC-NCI-MS) method, and the concentrations of thyroid hormones were determined as well. The sigma5PBDEs (BDE-28, -47, -153, -183, -209) concentrations(lipid weight) in serum ranged from 130.3 to 4 478.4 ng x g(-1), with an average value of 529.9 ng x g(-1). BDE-209 was a dominant PBDE congener, on average accounting for 69.8% of the total PBDEs concentrations. Spearman rank correlation coefficient was calculated between PBDEs and thyroid hormone, it showed that there were high significant negative correlation between BDE-28, -47, -153, -183 and thyroid-stimulating hormone (TSH), and significant negative correlation was also found between BDE-183 and free thyroxine (fT4). Additionally, there were significant positive correlation between BDE-28, -47 and triiodothyronine (T3), as well as between BDE-28, -153, -183 and free triiodothyronine(fT3). In summary, the concentrations of PBDEs in serum in this study were at a high level, and BDE-209 was the predominant congener. The exposure to the PBDEs may affect thyroid hormone levels, and the further research should focus on the relationship between PBDEs and thyroid hormone concentrations.