Anion Channel Inhibitor NPPB-Inhibited Fluoride Accumulation in Tea Plant (Camellia sinensis) Is Related to the Regulation of Ca²âº, CaM and Depolarization of Plasma Membrane Potential.

Tea plant is known to be a hyper-accumulator of fluoride (F). Over-intake of F has been shown to have adverse effects on human health, e.g., dental fluorosis. Thus, understanding the mechanisms fluoride accumulation and developing potential approaches to decrease F uptake in tea plants might be beneficial for human health. In the present study, we found that pretreatment with the anion channel inhibitor NPPB reduced F accumulation in tea plants. Simultaneously, we observed that NPPB triggered Ca(2+) efflux from mature zone of tea root and significantly increased relative CaM in tea roots. Besides, pretreatment with the Ca(2+) chelator (EGTA) and CaM antagonists (CPZ and TFP) suppressed NPPB-elevated cytosolic Ca(2+) fluorescence intensity and CaM concentration in tea roots, respectively. Interestingly, NPPB-inhibited F accumulation was found to be significantly alleviated in tea plants pretreated with either Ca(2+) chelator (EGTA) or CaM antagonists (CPZ and TFP). In addition, NPPB significantly depolarized membrane potential transiently and we argue that the net Ca(2+) and H⁺ efflux across the plasma membrane contributed to the restoration of membrane potential. Overall, our results suggest that regulation of Ca(2+)-CaM and plasma membrane potential depolarization are involved in NPPB-inhibited F accumulation in tea plants.

Al(3+) -promoted fluoride accumulation in tea plants (Camellia sinensis) was inhibited by an anion channel inhibitor DIDS.

BACKGROUND: Generally, tea plants are grown in acid soil which is rich in aluminum (Al) and fluoride (F). A recent publication showed that pretreatment with Al(3+) promoted F accumulation in tea plants by increasing endogenous Ca(2+) and calmodulin (CaM). A high level of F in tea leaves not only impairs tea quality but also might pose a health risk for people drinking tea regularly. Therefore it is important to try to find some clues which might be beneficial in controlling F accumulation in tea plants grown in acid soil (Al(3+) ). RESULTS: It was found that diisothiocyanostilbene-2,2-disulfonic acid (DIDS) significantly reduced Al(3+) -promoted F accumulation in tea plants. Additionally, Al(3+) plus DIDS treatment stimulated significantly higher Ca(2+) efflux and decreased the CaM level in tea roots compared with Al(3+) treatment. Besides, significantly higher depolarization of membrane potential was shown in tea roots treated with Al(3+) plus DIDS than in those treated with Al(3+) , as well as higher net total H(+) efflux and plasma membrane H(+) -ATPase activity. CONCLUSION: Al(3+) -promoted F accumulation in tea plants was inhibited by an anion channel inhibitor DIDS. Ca(2+) /CaM and membrane potential depolarization may be the components involved in this process. © 2016 Society of Chemical Industry.

FibroScan-aspartate transaminase: A superior non-invasive model for diagnosing high-risk metabolic dysfunction-associated steatohepatitis.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) with hepatic histological NAFLD activity score ≥ 4 and fibrosis stage F ≥ 2 is regarded as "at risk" non-alcoholic steatohepatitis (NASH). Based on an international consensus, NAFLD and NASH were renamed as metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH), respectively; hence, we introduced the term "high-risk MASH". Diagnostic values of seven non-invasive models, including FibroScan-aspartate transaminase (FAST), fibrosis-4 (FIB-4), aspartate transaminase to platelet ratio index (APRI), etc. for high-risk MASH have rarely been studied and compared in MASLD. AIM: To assess the clinical value of seven non-invasive models as alternatives to liver biopsy for diagnosing high-risk MASH. METHODS: A retrospective analysis was conducted on 309 patients diagnosed with NAFLD via liver biopsy at Beijing Ditan Hospital, between January 2012 and December 2020. After screening for MASLD and the exclusion criteria, 279 patients were included and categorized into high-risk and non-high-risk MASH groups. Utilizing threshold values of each model, sensitivity, specificity, positive predictive value (PPV), and negative predictive values (NPV), were calculated. Receiver operating characteristic curves were constructed to evaluate their diagnostic efficacy based on the area under the curve (AUROC). RESULTS: MASLD diagnostic criteria were met by 99.4% patients with NAFLD. The MASLD population was analyzed in two cohorts: Overall population (279 patients) and the subgroup (117 patients) who underwent liver transient elastography (FibroScan). In the overall population, FIB-4 showed better diagnostic efficacy and higher PPV, with sensitivity, specificity, PPV, NPV, and AUROC of 26.9%, 95.2%, 73.5%, 72.2%, and 0.75. APRI, Forns index, and aspartate transaminase to alanine transaminase ratio (ARR) showed moderate diagnostic efficacy, whereas S index and gamma-glutamyl transpeptidase to platelet ratio (GPR) were relatively weaker. In the subgroup, FAST had the highest diagnostic efficacy, its sensitivity, specificity, PPV, NPV, and AUROC were 44.2%, 92.3%, 82.1%, 67.4%, and 0.82. The FIB-4 AUROC was 0.76. S index and GPR exhibited almost no diagnostic value for high-risk MASH. CONCLUSION: FAST and FIB-4 could replace liver biopsy as more effectively diagnostic methods for high-risk MASH compared to APRI, Forns index, ARR, S index, and GPR; FAST is superior to FIB-4.

Ca(2+) and CaM are involved in Al(3+) pretreatment-promoted fluoride accumulation in tea plants (Camellia sinesis L.).

Tea plant (Camellia sinensis (L.) O. kuntze) is known to be a fluoride (F) and aluminum (Al(3+)) hyper-accumulator. Previous study showed that pre-treatment of Al(3+) caused a significant increase of F accumulation in tea plants. However, less is known about the intricate network of Al(3+) promoted F accumulation in tea plants. In this study, the involvement of endogenous Ca(2+) and CaM in Al(3+) pretreatment-promoted F accumulation in tea plants was investigated. Our results showed that Al(3+) induced the inverse change of intracellular Ca(2+) fluorescence intensity and stimulated Ca(2+) trans-membrane transport in the mature zone of tea root. Also, a link between internal Ca(2+) and CaM was found in tea roots under the presence of Al(3+). In order to investigate whether Ca(2+) and CaM were related to F accumulation promoted by Al(3+) pretreatment, Ca(2+) chelator EGTA and CaM antagonists CPZ and TFP were used. EGTA, CPZ, and TFP pretreatment inhibited Al(3+)-induced increase of Ca(2+) fluorescence intensity and CaM content in tea roots, and also significantly reduced Al(3+)-promoted F accumulation in tea plants. Taken together, our results suggested that the endogenous Ca(2+) and CaM are involved in Al(3+) pretreatment-promoted F accumulation in tea roots.

Co-occurrence trend of overweight,obesity and elevated blood pressure and its association with lifestyle factors among students in Inner Mongolia Autonomous Region / 中国学校卫生

Objective@#To explore the epidemiological trend of overweight and obesity, elevated blood pressure and their comorbidities in children and adolescents from Inner Mongolia Autonomous Region during 2016-2021, and to analyze its association with lifestyle, so as to provide reference for formulating prevention and control strategies of regional common comorbidities in schools.@*Methods@#A total of 8 908, 8 222, 9 448, 127 068, 100 778, and 138 540 students aged 10-18 years in Inner Mongolia were selected by stratified random cluster sampling in September each year from 2016 to 2021. Physical examination and questionnaire survey were conducted on the included students. The prevalence trends of overweight，obesity, elevated blood pressure and their co-occurrence were analyzed. Logistic regression was used to compare the prevalence of elevated blood pressure in different body mass index (BMI) groups. After excluding individuals without lifestyle information in 2021, Logistic regression analysis was used on 136 374 subjects to analyze the association between overweight，obesity, elevated blood pressure and their co-occurrence and lifestyle factors.@*Results@#During 2016 to 2021, the prevalence of comorbidity of overweight, obesity with elevated blood pressure among students in Inner Mongolia Autonomous Region were 5.04%，5.14%，4.99%，7.51%，7.60% and 9.45%， respectively . The prevalence of overweight and obesity was 26.94%, 28.07%, 29.62%, 34.19%, 36.71% and 37.53%, respectively. The prevalence of elevated blood pressure were 16.05%, 11.54%, 13.12%, 14.85%, 14.12% and 18.40%, respectively. Except for 2016, the risk of elevated blood pressure in overweight and obese people was higher than that in normal BMI group in other years, and there was a positive correlation between overweight and obesity and elevated blood pressure after gender and urban and rural areas ( P < 0.05 ). In 2021, the detection rate of comorbidity of overweight and obesity with elevated blood pressure among children and adolescents in urban areas was higher than that in suburban counties, and the reporting rate of healthy lifestyle was lower than that in suburban counties ( P <0.05).Skipping breakfast ( OR =1.11，95% CI =1.07-1.16) and non daily moderate and high intensity physical activity( OR =1.27，95% CI =1.20-1.34) were positively correlated with the co-occurrence of overweight，obesity and elevated blood pressure among children and adolescents in Inner Mongolia Autonomous Region. Non daily moderate and high intensity physical activity ≥60 min was positively correlated with elevated blood pressure ( OR =1.11，95% CI =1.07-1.16), and insufficient sleep was positively correlated with overweight，obesity ( OR =1.04, 95% CI =1.01-1.06)（ P ＜0.05）.@*Conclusion@#The prevalence of overweight，obesity, elevated blood pressure and their co-occurrence among children and adolescents in Inner Mongolia Autonomous Region is relatively high. Overweight/obesity is an important risk factor for elevated blood pressure, and unhealthy lifestyles are risk factors for co-occurrence of overweight，obesity and elevated blood pressure. Region specific lifestyle interventions are indispensable for the prevention and control of regional common comorbidities. Urban areas may be a key focus for lifestyle interventions.