Carbon chain length of perfluoroalkylated carboxylic acids determines inhibitory strength on gonadal 3ß-hydroxysteroid dehydrogenases in humans, rats, and mice.

Perfluoroalkylated carboxylic acids (PFCAs) are a subclass of man-made chemicals that have been widely used in industrial production and consumer products. As a result, PFCAs have been found to accumulate in the environment and bioaccumulate in organisms, leading to potential health and environmental impacts. This study investigated the inhibition of 11 PFCAs on gonadal 3ß-hydroxysteroid dehydrogenases in humans, rats, and mice. We observed a V-shaped inhibition pattern against human granulosa (KGN) cell 3ß-HSD2 starting from C9 (half-maximal inhibitory concentration, IC50, 100.8 µM) to C11 (8.92 µM), with a V-shaped turn. The same V-shaped inhibition pattern was also observed for PFCAs against rat testicular 3ß-HSD1 from C9 (IC50, 50.43 µM) to C11 (6.60 µM). Mouse gonadal 3ß-HSD6 was insensitive to the inhibition of PFCAs, with an IC50 of 50.43 µM for C11. All of these PFCAs were mixed inhibitors of gonadal 3ß-HSDs. Docking analysis showed that PFCAs bind to the nicotinamide adenine dinucleotide (NAD+)/steroid binding sites of these enzymes and bivariate correlation analysis showed that molecular length determines the inhibitory pattern of PFCAs on these enzymes. In conclusion, the carbon chain length determines the inhibitory strength of PFCAs on human, rat, and mouse gonadal 3ß-HSDs, and the inhibitory strength of PFCAs against human and rat 3ß-HSD enzymes shows V-shaped turn.

The analysis of pesticides and fungicides in the inhibition of human and rat placental 3ß-hydroxysteroid dehydrogenase activity: Mode of inhibition and mechanism.

3ß-Hydroxysteroid dehydrogenase/steroid Δ5,4-isomerase 1 (3ß-HSD1) plays a critical role in the biosynthesis of progesterone from pregnenolone in the human placenta to maintain normal pregnancy. Whether they inhibit placental 3ß-HSD1 and mode of inhibition remains unclear. In this study, we screened 21 pesticides and fungicides in five classes to inhibit human 3ß-HSD1 and compared them to rat homolog 3ß-HSD4. 3ß-HSD activity was measured by catalyzing pregnenolone to progesterone in the presence of NAD+. Of the 21 chemicals, azoles (difenoconazole), thiocarbamates (thiram and ferbam) and organochlorine (hexachlorophene) significantly inhibited human 3ß-HSD1 with half maximal inhibitory concentration (IC50) values of 2.77, 0.24, 0.68, and 17.96 µM, respectively. We also found that difenoconazole, ferbam and hexachlorophene are mixed/competitive inhibitors of 3ß-HSD1 while thiram is a mixed/noncompetitive inhibitor. Docking analysis showed that difenoconazole and hexachlorophene bound steroid-binding site. Difenoconazole and hexachlorophene except thiram and ferbam also significantly inhibited rat 3ß-HSD4 activity with IC50 of 1.12 and 2.28 µM, respectively. Thiram and ferbam significantly inhibited human 3ß-HSD1 possibly by interfering with cysteine residues, while they had no effects on rat 3ß-HSD4. In conclusion, some pesticides potently inhibit placental 3ß-HSD, leading to the reduction of progesterone formation.

Direct inhibition of human and rat 11ß-hydroxysteroid dehydrogenase 2 by per- and polyfluoroalkyl substances: Structure-activity relationship and in silico docking analysis.

Per- and polyfluoroalkyl substances (PFAS) are persistent in the environment and may disrupt the endocrine system. Our previous study showed that perfluorooctanoic acid (PFOA, C8) and perfluorooctanesulfonic acid (PFOS, C8S) can inhibit 11ß-hydroxysteroid dehydrogenase 2 (11ß-HSD2) activity leading to an active glucocorticoid accumulation. In this study, we extended investigation for 17 PFAS, including carboxylic and sulfonic acids, with different carbon-chain lengths, to determine their inhibitory potency and structure-activity relationship in human placental and rat renal 11ß-HSD2. C8-C14 PFAS at 100 µM significantly inhibited human 11ß-HSD2 with a potency as C10 (half-maximal inhibitory concentration, IC50, 9.19 µM) > C11 (15.09 µM) > C12 (18.43 µM) > C9 (20.93 µM) > C13 (124 µM) > C14 (147.3 µM) > other C4-C7 carboxylic acids, and C8S > C7S = C10S > other sulfonic acids. For rat 11ß-HSD2, only C9 and C10 and C7S and C8S PFAS exhibited significant inhibitory effects. PFAS are primarily mixed/competitive inhibitors of human 11ß-HSD2. Preincubation and simultaneous incubation with the reducing agent dithiothreitol significantly increased human 11ß-HSD2 but not rat 11ß-HSD2, and preincubation but not simultaneous incubation with dithiothreitol partially reversed C10-mediated inhibition on human 11ß-HSD2. Docking analysis showed that all PFAS bound to the steroid-binding site and carbon-chain length determined the potency of inhibition, with the optimal molecular length (12.6 Å) for potent inhibitors PFDA and PFOS, which is comparable to the molecular length (12.7 Å) of the substrate cortisol. The length between 8.9 and 17.2 Å is the probable threshold molecular length to inhibit human 11ß-HSD2. In conclusion, the carbon-chain length determines the inhibitory effect of PFAS on human and rat 11ß-HSD2, and the inhibitory potency of long-chain PFAS on human and rat 11ß-HSD2 showed V-shaped pattern. Long-chain PFAS may partially act on the cysteine residues of human 11ß-HSD2.

Structure-activity relationship analysis of perfluoroalkyl carbonic acids on human and rat placental 3ß-hydroxysteroid dehydrogenase activity.

Placenta contains 3ß-hydroxysteroid dehydrogenase/steroid Δ5,4-isomerase (HSD3B), which catalyzes pregnenolone to progesterone for maintaining pregnancy. Perfluoroalkyl carbonic acids (PFC) are subclass of perfluoroalkyl substances containing 4-14 carbons (C4-C14) in the carbon backbone and are potential endocrine disruptors. Whether PFC inhibit HSD3B and structure-activity relationship (SAR) remains unclear. Herein, we screened 11 PFC for inhibiting human type I HSD3B (HSD3B1) and rat type IV HSD3B (HSD3B4) activities and determined SAR and mode of inhibition. HSD3B was measured by converting pregnenolone to progesterone assisted by NAD+ in placental microsomes. Of the 11 PFC, C9-C14 significantly inhibited human HSD3B1 activity at 100 µM. Half-maximal inhibitory concentration (IC50) values of C9-C14 compounds were 363.56 ± 12.14, 12.78 ± 0.69, 6.54 ± 0.65, 20.88 ± 0.41, 118.35 ± 0.16, and 149.26 ± 21.67 µM, respectively. We determined Ki values and mode of inhibition of three most potent PFC (C10-C12), and found that they were mixed inhibitors against pregnenolone, with Ki values of 5.57 ± 4.37, 2.04 ± 2.26, and 9.93 ± 7.71, respectively. Docking analysis showed that they bound steroid-binding site. Effects of PFC on rat placental HSD3B4 were performed. Of the 11 PFC, C10-C12 significantly inhibited rat HSD3B4 activity at 100 µM. IC50 values of C10-C12 compounds were 45.85 ± 1.49, 36.08 ± 1.50, and 88.74 ± 1.99 µM, respectively. Ki values and inhibition modes of the three most potent PFC (C10-C12) were studied. It was found that they were mixed inhibitors against pregnenolone, with Ki values of 48.16 ± 20.44, 36.28 ± 53.07, and 91.79 ± 21.75 µM, respectively. Docking analysis showed that they bound steroid-binding site of rat HSD3B4. In conclusion, PFC showed significant SAR differences. The potency of inhibiting HSD3B activity increased from C9 to C11, and then declined. Human HSD3B1 was more sensitive to the inhibition of rat HSD3B4.

Pan-cancer analysis of SETD2 mutation and its association with the efficacy of immunotherapy.

Histone methyltransferase SETD2 plays a critical role in maintaining genomic integrity and stability. Here, we investigated the characteristics of SETD2 somatic mutation in the cancer genome atlas pan-cancer cohort. Our data revealed that, compared with SETD2 nonmutant patients, SETD2 mutant patients had higher tumor mutation burden and microsatellite instability. In addition, the transcriptions of most genes related to immune activities were upregulated in patients with SETD2 mutant tumors. Further examination of cancer patients treated with immune checkpoint inhibitors suggested SETD2 mutation was associated with favorable clinical outcomes. These results have implication for the personalization of cancer immunotherapy.