Per- and polyfluoroalkyl substances inhibit human and rat 17ß-hydroxysteroid dehydrogenase 1: Quantitative structure-activity relationship and molecular docking analysis.

Per- and polyfluoroalkyl (PFAS) substances are enduring industrial materials. 17ß-Hydroxysteroid dehydrogenase isoform 1 (17ß-HSD1) is an estrogen metabolizing enzyme, which transforms estrone into estradiol in human placenta and rat ovary. Whether PFAS inhibit 17ß-HSD1 and what the structure-activity relationship (SAR) remains unexplored. We screened 18 PFAS for inhibiting human and rat 17ß-HSD1 in microsomes and studied their SAR and mode of action(MOA). Of the 11 perfluorocarboxylic acids (PFCAs), C8-C14 PFCAs at a concentration of 100 µM substantially inhibited human 17ß-HSD1, with order of C11 (half-maximal inhibition concentration, IC50, 8.94 µM) > C10 (10.52 µM) > C12 (14.90 µM) > C13 (30.97 µM) > C9 (43.20 µM) > C14 (44.83 µM) > C8 (73.38 µM) > others. Of the 7 per- and poly-fluorosulfonic acids (PFSAs), the potency was C8S (IC50, 14.93 µM) > C7S (80.70 µM) > C6S (177.80 µM) > others. Of the PFCAs, C8-C14 PFCAs at 100 µM markedly reduced rat 17ß-HSD1 activity, with order of C11 (IC50, 9.11 µM) > C12 (14.30 µM) > C10 (18.24 µM) > C13 (25.61 µM) > C9 (67.96 µM) > C8 (204.39 µM) > others. Of the PFSAs, the potency was C8S (IC50, 37.19 µM) > C7S (49.38 µM) > others. In contrast to PFOS (C6S), the partially fluorinated compound 6:2 FTS with an equivalent number of carbon atoms demonstrated no inhibition of human and rat 17ß-HSD1 activity at a concentration of 100 µM. The inhibition of human and rat enzymes by PFAS followed a V-shaped trend from C4 to C14, with a nadir at C11. Moreover, human 17ß-HSD1 was more sensitive than rat enzyme. PFAS inhibited human and rat 17ß-HSD1 in a mixed mode. Docking analysis revealed that they bind to the NADPH and steroid binding site of both 17ß-HSD1 enzymes. The 3D quantitative SAR (3D-QSAR) showed that hydrophobic region, hydrogen bond acceptor and donor are key factors in binding to 17ß-HSD1 active sites. In conclusion, PFAS exhibit inhibitory effects on human and rat 17ß-HSD1 depending on factors such as carbon chain length, degree of fluorination, and the presence of carboxylic acid or sulfonic acid groups, with a notable V-shaped shift observed at C11.

Trichlorfon blocks androgen synthesis and metabolism in rat immature Leydig cells.

Trichlorfon is a widely used organophosphorus insecticide. It has been reported that it has reproductive toxicity to animal models. However, whether trichlorfon affects testosterone biosynthesis and metabolism remains unclear. In this study, we explored the effects of trichlorfon on the steroidogenesis and the expression of genes in androgen biosynthetic and metabolic cascades in immature Leydig cells isolated from pubertal male rats. Immature Leydig cells were treated with trichlorfon (0.5-50 µM) for 3 h. Trichlorfon significantly inhibited total androgen output under basal condition at 5 and 50 µM, and under LH- and cAMP-stimulated conditions at 50 µM. Trichlorfon also downregulated the expression of Star, Sod2, and Gpx1 and their proteins at 5 and 50 µM and the expression of Cyp11a1, Hsd3b1, Cyp17a1, and Srd5a1 at 50 µM. Trichlorfon significantly inhibited total androgen output at 50 µM, which was partially reversed by 400 µg/ml vitamin E, which alone had no effects on androgen output. In conclusion, trichlorfon downregulates the expression of steroidogenesis-related genes and antioxidants, which leads to a decrease in androgen production in rat immature Leydig cells.

Abnormal intrinsic functional hubs in alcohol dependence: evidence from a voxelwise degree centrality analysis.

OBJECTIVE: To explore the abnormal intrinsic functional hubs in alcohol dependence using voxelwise degree centrality analysis approach, and their relationships with clinical features. MATERIALS AND METHODS: Twenty-four male alcohol dependence subjects free of medicine (mean age, 50.21±9.62 years) and 24 age- and education-matched male healthy controls (mean age, 50.29±8.92 years) were recruited. The alcohol use disorders identification test and the severity of alcohol dependence questionnaire (SADQ) were administered to assess the severity of alcohol craving. Voxelwise degree centrality approach was used to assess the abnormal intrinsic functional hubs features in alcohol dependence. Simple linear regression analysis was performed to investigate the relationships between the clinical features and abnormal intrinsic functional hubs. RESULTS: Compared with healthy controls, alcohol dependence subjects exhibited significantly different degree centrality values in widespread left lateralization brain areas, including higher degree centrality values in the left precentral gyrus (BA 6), right hippocampus (BA 35, 36), and left orbitofrontal cortex (BA 11) and lower degree centrality values in the left cerebellum posterior lobe, bilateral secondary visual network (BA 18), and left precuneus (BA 7, 19). SADQ revealed a negative linear correlation with the degree centrality value in the left precentral gyrus (R2=0.296, P=0.006). CONCLUSION: The specific abnormal intrinsic functional hubs appear to be disrupted by alcohol intoxication, which implicates at least three principal neural systems: including cerebellar, executive control, and visual cortex, which may further affect the normal motor behavior such as an explicit type of impaired driving behavior. These findings expand our understanding of the functional characteristics of alcohol dependence and may provide a new insight into the understanding of the dysfunction and pathophysiology of alcohol dependence.

[Experimental study on detoxication effect of sulfhydryl compounds in acute poisoning of dimethylformamide].

OBJECTIVE: To study the change in oxidase and anti-oxidase in liver of the mice poisoned by dimethylformamide (DMF), and the effects of the treatment with sulfhydryl compounds in acute poisoning of DMF. METHODS: The sulfhydryl compounds included sodium dimercaptopropane (Na-DMPS), N-acetylcysteine (NAC), glutathione (GSH) and dimercaptosuccinic acid (DMSA). The model of acute poisoning with DMF in mice was reproduced, and the left hepatic lobes were harvested at 6, 12, 24, 48 and 72 hours after DMF to detect the dynamic changes in the activities of superoxide dismutase (SOD) and xanthine oxidase (XOD) in liver homogenate. Treatment groups included intraperitoneal injection of Na-DMPS, NAC, GSH, DMSA respectively. In the control groups, the activities of XOD and SOD in liver were determined 24 hours after intragastric administration of DMF. RESULTS: The activities of XOD, SOD in liver were elevated at 24 hours after intragastric administration of DMF (both P<0.01), and returned to the normal levels at 48-72 hours. Compared to the poisoning group, the activities of XOD, SOD in liver homogenate were significantly lowered after the treatment of Na-DMPS, NAC and DMSA (P<0.05 or P<0.01). The activity of XOD in liver homogenate was reduced 24 hours after treating with GSH (P<0.05), and no obvious change was observed in SOD (P>0.05). As far as the activity of SOD was concentrated, Na-DMPS, NAC, DMSA showed better effects than GSH (all P<0.05), and Na-DMPS was the best. There was no significant differences in XOD among the four sulfhydryl compounds. CONCLUSION: The balance of oxidase and anti-oxidase is interrupted by DMF, which might be one of the mechanisms of damage to the liver. Na-DMPS, NAC and DMSA could protect liver function by restoring the balance.