Genetic analysis of 11 beta-hydroxysteroid dehydrogenase

Clinical and molecular characterization of 10 Chinese children with congenital adrenal hyperplasia due to 11beta-hydroxylase deficiency

BACKGROUND

The clinical manifestations of nonclassical 11beta-hydroxylase deficiency are very similar to those of non-classical 21-hydroxylase deficiency. For this study, we investigated the relationship between the clinical and molecular features of congenital adrenal hyperplasia caused by 11beta-hydroxylase deficiency and reviewed the related literature, which are expected to provide assistance for the clinical diagnosis and analysis of congenital adrenal hyperplasia.

METHODS

Clinical data for 10 Chinese patients diagnosed with congenital adrenal hyperplasia in our hospital from 2018 to 2022 were retrospectively analyzed. We examined the effects of gene mutations on protease activity and constructed three-dimensional structure prediction models of proteins.

RESULTS

We describe 10 patients with 11beta-hydroxylase gene mutations (n = 5, 46,XY; n = 5, 46,XX), with 10 novel mutations were reported. Female patients received treatment at an early stage, with an average age of 2.08 ± 1.66 years, whereas male patients received treatment significantly later, at an average age of 9.77 ± 3.62 years. The most common CYP11B1 pathogenic variant in the Chinese population was found to be c.1360C > T. All mutations lead to spatial conformational changes that affect protein stability.

CONCLUSIONS

Our study found that there was no significant correlation between each specific mutation and the severity of clinical manifestations. Different patients with the same gene pathogenic variant may have mild or severe clinical manifestations. The correlation between genotype and phenotype needs further study. Three-dimensional protein simulations may provide additional support for the physiopathological mechanism of genetic mutations.

5-Bis-(2,6-difluoro-benzylidene) Cyclopentanone Acts as a Selective 11β-Hydroxysteroid Dehydrogenase one Inhibitor to Treat Diet-Induced Nonalcoholic Fatty Liver Disease in Mice

Background: 11β-Hydroxysteroid dehydrogenase one is responsible for activating inert glucocorticoid cortisone into biologically active cortisol in humans and may be a novel target for the treatment of nonalcoholic fatty liver disease.

Methods: A series of benzylidene cyclopentanone derivatives were synthesized, and the selective inhibitory effects on rat, mouse and human 11β-hydroxysteroid dehydrogenase one and two were screened. The most potent compound [5-bis-(2,6-difluoro-benzylidene)-cyclopentanone] (WZS08), was used to treat nonalcoholic fatty liver disease in mice fed a high-fat-diet for 100 days.

Results: WZS08 was the most potent inhibitor of rat, mouse, and human 11β-hydroxysteroid dehydrogenase 1, with half maximum inhibitory concentrations of 378.0, 244.1, and 621.1 nM, respectively, and it did not affect 11β-hydroxysteroid dehydrogenase two at 100 μM. When mice were fed WZS08 (1, 2, and 4 mg/kg) for 100 days, WZS08 significantly lowered the serum insulin levels and insulin index at 4 mg/kg. WZS08 significantly reduced the levels of serum triglycerides, cholesterol, low-density lipoprotein, and hepatic fat ratio at low concentration of 1 mg/kg. It down-regulated Plin2 expression and up-regulated Fabp4 expression at low concentration of 1 mg/kg. It significantly improved the morphology of the non-alcoholic fatty liver.

Conclusion: WZS08 selectively inhibits rat, mouse, and human 11β-hydroxysteroid dehydrogenase 1, and can treat non-alcoholic fatty liver disease in a mouse model.

Steroid 11beta- hydroxylase deficiency congenital adrenal hyperplasia

Congenital adrenal hyperplasia due to steroid 11beta-hydroxylase deficiency is a genetic disorder of steroidogenesis, transmitted as an autosomal recessive trait. It is associated with low renin hypertension, hypokalemia, hyperandrogenemia and genital ambiguity in affected females. Mutations in the CYP11B1 gene, causing 11beta-hydroxylase deficiency in the zona fasciculata in the adrenal cortex, have been identified. The indicators of congenital adrenal hyperplasia caused by 11beta-hydroxylase deficiency, include increased serum concentrations of desoxycorticosterone, 11 deoxycortisol and delta4-androstenedione, and suppressed plasma renin concentrations. The disorder is treated by administration of glucocorticoids.

Effects of glucose on blood pressure and production of vascular aldosterone and corticosterone

OBJECTIVE

The aims of this study were to search for the role of glucose in the regulation blood pressure of rats and to investigate the effects of glucose on the production of vascular aldosterone and corticosterone in rats.

METHODS

Male Wistar rats received glucose 15.0 g x kg(-1) x d(-1) (glucose-treated group 1) or 25.0 g x kg(-1) x d(-1) (glucose-treated group 2) or 35.0 g x kg(-1) x d(-1) (glucose-treated group 3), orally, for 3 months, and blood pressure was monitored by a pressure transducer. Mesenteric artery perfusion ex vivo was performed and pressor responses to norepinephrine were determined in Wistar rats. The perfusate from the mesenteric arteries was collected and applied to a Sep-Pak C 18 cartridge column for reverse phase high-performance liquid chromatography and levels of both aldosterone and corticosterone were determined by radioimmunoassay. Reverse transcriptase polymerase chain reaction was used to measure the expression of 11beta-HSD2 and CYP11B2 mRNA in mesenteric arteries.

RESULTS

Blood pressure increased in Wistar rats treated with glucose compared to control rats. The pressor responses to norepinephrine in mesenteric arteries treated with glucose were significantly increased. Levels of aldosterone were decreased but those of corticosterone increased in the perfusate from arteries treated with glucose. Reverse transcriptase polymerase chain reaction showed that glucose inhibited the expression of 11beta-HSD2 and CYP11B2 mRNA in mesenteric arteries.

CONCLUSION

These results reveal that glucose able to induce hypertension and provide evidence that glucose inhibits the transcriptions of both 11beta-HSD2 and CYP 11B2 in vasculature, leading to lower aldosterone and higher corticosterone production in vessels, and increased vasoconstrictor responses to norepinephrine.

Effects of alcohol on blood pressure and production of vascular aldosterone and corticosterone

AIMS

The aims of this study were to search for the role of alcohol in blood pressure regulation in rats and to investigate the effects of alcohol on the production of vascular aldosterone and corticosterone.

METHODS

Male Wistar rats received alcohol 0.7 g x kg(-1) x day(-1) (alcohol-treated group 1) or 1.4 g x kg(-1) x day(-1) (alcohol-treated group 2) or 2.1 g x kg(-1) x day(-1) (alcohol-treated group 3), orally, for 3 months, and blood pressure was monitored by a pressure transducer. Systolic blood pressure increased in Wistar rats treated with alcohol compared to control rats. Mesenteric artery perfusion ex vivo was performed and pressor responses to norepinephrine were determined. The pressor responses to norepinephrine in mesenteric arteries treated with alcohol were significantly increased. The perfusate from the mesenteric arteries was collected and applied to a Sep-Pak C 18 cartridge column for reverse-phase high-performance liquid chromatography and aldosterone and corticosterone levels were determined by radioimmunoassay, aldosterone was decreased but corticosterone was increased in the perfusate from arteries treated with alcohol.

RESULTS

Reverse transcriptase polymerase chain reaction showed that alcohol inhibited the expression of 11beta-HSD2 and CYP11B2 mRNA in mesenteric arteries.

CONCLUSIONS

These results reveal that alcohol is able to induce hypertension and provide evidence that alcohol inhibits the transcriptions of both 11beta-HSD2 and CYP11B2 in the vasculature, leading to lower aldosterone and higher corticosterone production in vessels, and increased vasoconstrictor responses to norepinephrine.

Effects of glycyrrhizin on production of vascular aldosterone and corticosterone

This study is to confirm the role of glycyrrhizin on blood pressure and to test the effects of glycyrrhizin on production of vascular aldosterone and corticosterone in rats. Male Wistar rats received glycyrrhizin (Sigma) 200 mg/kg/day p.o. for 5 weeks, and blood pressure was monitored by a pressure transducer. Systolic blood pressure significantly increased in Wistar rats treated with glycyrrhizin compared to that without glycyrrhizin. Mesenteric artery perfusion ex vivo and pressor responses to norepinephrine were performed. The pressor responses to norepinephrine in mesenteric arteries treated with glycyrrhizin were significantly increased. The perfusate from the mesenteric arteries was collected and applied to a Sep-Pak C 18 cartridge column, used for reverse-phase high-performance liquid chromatography, and measured for both aldosterone and corticosterone by radioimmunoassay. Levels of aldosterone were decreased but those of corticosterone increased in perfusate from arteries treated with glycyrrhizin. RT-PCR showed that glycyrrhizin inhibited the expression of 11beta- HSD2 and CYP11B2 mRNA in mesenteric arteries. These results confirm that glycyrrhizin is able to induce hypertension, and provide evidence that it inhibits the transcriptions of both 11beta-HSD2 and CYP11B2 in the vasculature, leading to lower aldosterone and higher corticosterone production in vessels, and increased vasoconstrictor responses to norepinephrine.

Effects of cholic acid on blood pressure and production of vascular aldosterone and corticosterone

The aims of this study were to search for the role of cholic acid in the regulation blood pressure of humans and rats and to investigate the effects of cholic acid on the production of vascular aldosterone and corticosterone in rats. Levels of serum total bile acids were measured by an enzymic spectrophotometeric method in normal controls, patients with essential hypertension, and in Wistar and spontaneously hypertensive rats. Levels in essential hypertension (7.3+/-3.4 micromol/l, n = 88) were higher than those of normal subjects (4.9+/-3.3 micromol/l, n = 86), and levels in SHR (13.9+/-3.8 micromol/l, n = 11) were slightly increased, but not significantly different from Wistar rats (10.4+/-5.1 micromol/l, n = 12). Male Wistar rats received cholic acid 80 mg/kg/day, orally, for 30 days, and blood pressure was monitored by a pressure transducer. Systolic blood pressure increased in Wistar rats treated with cholic acid compared to control rats. Mesenteric artery perfusion ex vivo was performed, and pressor responses to norepinephrine were determined in Wistar rats. The pressor responses to norepinephrine in mesenteric arteries treated with cholic acid were significantly increased. The perfusate from the mesenteric arteries was collected and applied to a Sep-Pak C 18 cartridge column for reverse phase high performance liquid chromatography, and levels of both aldosterone and corticosterone were determined by radioimmunoassay. Levels of aldosterone were decreased but those of corticosterone increased in the perfusate from arteries treated with cholic acid. Reverse transcriptase polymerase chain reaction showed that cholic acid inhibited the expression of 11beta-HSD2 and CYP11B2 mRNA in mesenteric arteries. These results reveal that cholic acid is able to induce hypertension and provide evidence that cholic acid inhibits the transcription of both 11beta-HSD2 and CYP11B2 in vasculature, leading to lower aldosterone and higher corticosterone production in vessels and increased vasoconstrictor responses to norepinephrine.

Serines at the active site of 11 beta-hydroxysteroid dehydrogenase type I determine the rate of catalysis

Short chain alcohol dehydrogenases have an invariant YXXXK motif at the active site. Database analysis of 116 superfamily members showed that 92% also contain a Serine or Threonine residue at the Y + 1 or Y + 3 positions, a pattern we previously described as the ST rule. In the present study we have mutated Serines in the active site, YSASK, motif of 11 beta-hydroxysteroid dehydrogenase type I (11 beta HSD1). These studies were facilitated by the generation of a new specific polyclonal antibody (RAH113) raised against a synthetic peptide derived from the rat 11 beta-HSD1 sequence. Immunopurified RAH113 recognized a single band at 34 kDa in liver homogenates. Kinetic analysis of equivalent amounts of wild type and mutant proteins showed that mutagenesis of active site Serines resulted in modest increases of Km values for corticosterone from 325 nM for 11 beta HSD1 to 512 nM-588 nM for the S1 (YAASK), S2 (YSAGK) and S3 (YAAGK) mutants in homogenates of transfected CHOP cells. However, far greater effects were observed on the first order rate constants with mutants displaying 10%, 1% and 1% of the wild type activity, respectively. When the oxidoreductase reaction was studied in whole cells mutagenesis again had a minimal effect on the Km value but dramatically lowered first order rate constants to 34%, 5% and 6%, respectively, of the wild type. These data show that Serines at the active site of 11 beta HSD1 play an important role in determining the rate of catalysis. Coexpression of wild type and mutant enzymes did not lower wild type activity suggesting that the active site of the multimeric enzyme is not a composite of active site Serines from different subunits.

A tactile sensory system of Myxococcus xanthus involves an extracellular NAD(P)(+)-containing protein

CsgA is a cell surface protein that plays an essential role in tactile responses during Myxococcus xanthus fruiting body formation by producing the morphogenic C-signal. The primary amino acid sequence of CsgA exhibits homology with members of the short-chain alcohol dehydrogenase (SCAD) family and several lines of evidence suggest that NAD(P)+ binding is essential for biological activity. First, the predicted CsgA secondary structure based on the 3 alpha/20 beta-hydroxysteroid dehydrogenase crystal structure suggests that the amino-terminal portion of the protein contains an NAD(P)+ binding pocket. Second, strains with csgA alleles encoding amino acid substitutions T6A and R10A in the NAD(P)+ binding pocket failed to develop. Third, exogenous MalE-CsgA rescues csgA development, whereas MalE-CsgA with the amino acid substitution CsgA T6A does not. Finally, csgA spore yield increased approximately 20% when containing 100 nM of MalE-CsgA was supplemented with 10 microM of NAD+ or NADP+. Conversely, 10 microM of NADH or NADPH delayed development for approximately 24 hr and depressed spore levels approximately 10%. Together, these results argue that NAD(P)+ binding is critical for C-signaling. S135 and K155 are conserved amino acids in the catalytic domain of SCAD members. Strains with csgA alleles encoding the amino acid substitutions S135T or K155R failed to develop. Furthermore, a MalE-CsgA protein containing CsgA S135T was not able to restore development to csgA cells. In conclusion, amino acids conserved in the coenzyme binding pocket and catalytic site are essential for C-signaling.

Enzymes and receptors: challenges and future directions

In many ways, the present paper will cover much of the same ground as those that precede it. As its title suggests, it is an overview--in part to highlight various aspects of the areas which have been discussed, and in part to put a personal view of where the most fruitful avenues for exploration over the next two years lie. It is very clearly not a comprehensive summary of the topic; given the delightful unpredictability of biological advance, there is every likelihood such predictions may prove substantially wrong. On the other hand, nothing ventured, nothing won; and so with this caveat, there follows one man's reckoning of the directions for the immediate future.