In silico analysis of potential inhibitors for breast cancer targeting 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) catalyses.

Breast cancer (BC) is still one of the major issues in world health, especially for women, which necessitates innovative therapeutic strategies. In this study, we investigated the efficacy of retinoic acid derivatives as inhibitors of 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1), which plays a crucial role in the biosynthesis and metabolism of oestrogen and thereby influences the progression of BC and, the main objective of this investigation is to identify the possible drug candidate against BC through computational drug design approach including PASS prediction, molecular docking, ADMET profiling, molecular dynamics simulations (MD) and density functional theory (DFT) calculations. The result has reported that total eight derivatives with high binding affinity and promising pharmacokinetic properties among 115 derivatives. In particular, ligands 04 and 07 exhibited a higher binding affinity with values of -9.9 kcal/mol and -9.1 kcal/mol, respectively, than the standard drug epirubicin hydrochloride, which had a binding affinity of -8.2 kcal/mol. The stability of the ligand-protein complexes was further confirmed by MD simulations over a 100-ns trajectory, which included assessments of hydrogen bonds, root mean square deviation (RMSD), root mean square Fluctuation (RMSF), dynamic cross-correlation matric (DCCM) and principal component analysis. The study emphasizes the need for experimental validation to confirm the therapeutic utility of these compounds. This study enhances the computational search for new BC drugs and establishes a solid foundation for subsequent experimental and clinical research.

Inhibitory effects of parabens on human and rat 17ß-hydroxysteroid dehydrogenase 1: Mechanisms of action and impact on hormone synthesis.

Parabens are commonly used preservatives in cosmetics, food, and pharmaceutical products. The objective of this study was to examine the effect of nine parabens on human and rat 17ß-hydroxysteroid dehydrogenase 1 (17ß-HSD1) in human placental and rat ovarian cytosols, as well as on estradiol synthesis in BeWo cells. The results showed that the IC50 values for these compounds varied from methylparaben with the weakest inhibition (106.42 µM) to hexylparaben with the strongest inhibition (2.05 µM) on human 17ß-HSD1. Mode action analysis revealed that these compounds acted as mixed inhibitors. For rats, the IC50 values ranged from the weakest inhibition for methylparaben (no inhibition at 100 µM) to the most potent inhibition for hexylparaben (0.87 µM), and they functioned as mixed inhibitors. Docking analysis indicated that parabens bind to the region bridging the NADPH and steroid binding sites of human 17ß-HSD1 and the NADPH binding site of rat 17ß-HSD1. Bivariate correlation analysis demonstrated negative correlations between LogP, molecular weight, heavy atoms, and apolar desolvation energy, and the IC50 values of these compounds. In conclusion, this study identified the inhibitory effects of parabens and their binding mechanisms on human and rat 17ß-HSD1, as well as their impact on hormone synthesis.

Expression and purification of active human 17ß-Hydroxysteroid dehydrogenase type 1 from Escherichia coli.

Breast cancer cell growth is often dependent on the presence of steroidal hormones. The 17ß-hydroxysteroid dehydrogenase type 1 isoform (17ßHSD1) catalyzes NADPH-dependent conversion of estrone to estradiol, a more potent estrogen, and represents potential drug target for breast cancer treatment.  To provide active enzyme for inhibitor screening, 17ßHSD1 is usually expressed in insect or mammalian cells, or isolated from human placenta. In the present study we describe a simple protocol for expression and purification of active human 17ßHSD1 from BL21(DE3) Escherichia coli cells. Soluble human 17ßHSD1 was expressed using a pET28a(+)-based plasmid, which encodes a hexahistidine tag fused to the N-terminus of the protein, and purified by nickel affinity chromatography. The enzyme activity of purified 17ßHSD1 was verified by three methods: thin-layer chromatography, an alkali assay and a spectroscopic assay. These non-radioactive enzyme assays require only standard laboratory equipment, and can be used for screening compounds that modulate 17ßHSD1 activity.

Potent inhibition of human and rat 17ß-hydroxysteroid dehydrogenase 1 by curcuminoids and the metabolites: 3D QSAR and in silico docking analysis.

Curcumin, an extensively utilized natural pigment in the food industry, has attracted considerable attention due to its potential therapeutic effects, such as anti-tumorigenic and anti-inflammatory activities. The enzyme 17ß-Hydroxysteroid dehydrogenase 1 (17ß-HSD1) holds a crucial position in oestradiol production and exhibits significant involvement in oestrogen-responsive breast cancers and endometriosis. This study investigated the inhibitory effects of curcuminoids, metabolites, and analogues on 17ß-HSD1, a key enzyme in oestradiol synthesis. Screening 10 compounds, including demethoxycurcumin (IC50, 3.97 µM) and dihydrocurcumin (IC50, 5.84 µM), against human and rat 17ß-HSD1 revealed varying inhibitory potencies. These compounds suppressed oestradiol secretion in human BeWo cells at ≥ 5-10 µM. 3D-Quantitative structure-activity relationship (3D-QSAR) and molecular docking analyses elucidated the interaction mechanisms. Docking studies and Gromacs simulations suggested competitive or mixed binding to the steroid or NADPH/steroid binding sites of 17ß-HSD1. Predictive 3D-QSAR models highlighted the importance of hydrophobic regions and hydrogen bonding in inhibiting 17ß-HSD1 activity. In conclusion, this study provides valuable insights into the inhibitory effects and mode of action of curcuminoids, metabolites, and analogues on 17ß-HSD1, which may have implications in the field of hormone-related disorders.

Synthesis and characterization of targeted 17ß-hydroxysteroid dehydrogenase type 7 inhibitors.

Sex steroid hormones such as estrogen estradiol (E2) and androgen dihydrotestosterone (DHT) are involved in the development of hormone-dependent cancers. Blockade of 17ß-hydroxysteroid dehydrogenase type 7 (17ß-HSD7), a member of the short chain dehydrogenase/reductase superfamily, is thought to decrease E2 levels while increasing those of DHT. Therefore, its unique double action makes this enzyme as an interesting drug target for treatment of breast cancer. The chemical synthesis, molecular characterization, and preliminary biological evaluation as 17ß-HSD7 inhibitors of novel carbamate derivatives 3 and 4 are described. Like previous 17ß-HSD7 inhibitors 1 and 2, compounds 3 and 4 bear a hydrophobic nonyl side chain at the C-17ß position of a 4-aza-5α-androstane nucleus, but compound 3 has an oxygen atom replacing the CH2 in the steroid A-ring C-2 position, while compound 4 has a C17-spiranic E-ring containing a carbamate function. They both inhibited the in vitro transformation of estrone (E1) into E2 by 17ß-HSD7, but the introduction of a (17 R)-spirocarbamate is preferable to replacing C-2 methylene with an oxygen atom since compound 4 (IC50 = 63 nM) is an inhibitor 14 times more powerful than compound 3 (IC50 = 900 nM). Furthermore, when compared to the reference inhibitor 1 (IC50 = 111 nM), the use of a C17-spiranic E-ring made it possible to introduce differently the hydrophobic nonyl side chain, without reducing the inhibitory activity.

Effects of organochlorine pesticides on human and rat 17ß-hydroxysteroid dehydrogenase 1 activity: Structure-activity relationship and in silico docking analysis.

The objective of this study was to examine the effect of 11 organochlorine pesticides on human and rat 17ß-Hydroxysteroid dehydrogenase 1 (17ß-HSD1) in human placental and rat ovarian microsome and on estradiol production in BeWo cells. The results showed that the IC50 values for endosulfan, fenhexamid, chlordecone, and rhothane on human 17ß-HSD1 were 21.37, 73.25, 92.80, and 117.69 µM. Kinetic analysis revealed that endosulfan acts as a competitive inhibitor, fenhexamid as a mixed/competitive inhibitor, chlordecone and rhothane as a mixed/uncompetitive inhibitor. In BeWo cells, all insecticides except endosulfan significantly decreased estradiol production at 100 µM. For rats, the IC50 values for dimethomorph, fenhexamid, and chlordecone were 11.98, 36.92, and 109.14 µM. Dimethomorph acts as a mixed inhibitor, while fenhexamid acts as a mixed/competitive inhibitor. Docking analysis revealed that endosulfan and fenhexamid bind to the steroid-binding site of human 17ß-HSD1. On the other hand, chlordecone and rhothane binds to a different site other than the steroid and NADPH-binding site. Dimethomorph binds to the steroid/NADPH binding site, and fenhexamid binds to the steroid binding site of rat 17ß-HSD1. Bivariate correlation analysis showed a positive correlation between IC50 values and LogP for human 17ß-HSD1, while a slight negative correlation was observed between IC50 values and the number of HBA. ADMET analysis provided insights into the toxicokinetics and toxicity of organochlorine pesticides. In conclusion, this study identified the inhibitory effects of 3-4 organochlorine pesticides and binding mechanisms on human and rat 17ß-HSD1, as well as their impact on hormone production.

Chemical Synthesis and Biological Evaluation of 3-Substituted Estrone/Estradiol Derivatives as 17ß-Hydroxysteroid Dehydrogenase Type 1 Inhibitors Acting via a Reverse Orientation of the Natural Substrate Estrone.

Estradiol (E2) plays an important role in the progression of diseases such as breast cancer and endometriosis. Inhibition of 17ß-hydroxysteroid dehydrogenase type 1 (17ß-HSD1), the enzyme that catalyzes the last step in the biosynthesis of the estrogenic hormone E2, therefore constitutes an interesting approach for the treatment of these two estrogen-dependent diseases. In order to obtain new inhibitors of 17ß-HSD1, the impact of a m-carbamoylphenyloxy group at position three of an estrane nucleus was evaluated by preparing three derivatives of estrone (E1) and E2 using a microwave-assisted synthesis of diaryl ethers. Their inhibitory activity was addressed on two cell lines (T-47D and Z-12) representative of breast cancer and endometriosis, respectively, but unlike T-47D cells, Z-12 cells were not found suitable for testing potential 17ß-HSD1 inhibitors. Thus, the addition of the m-carbamoylphenyl group at C3 of E1 (compound 5) did not increase the inhibition of E1 to E2 transformation by 17ß-HSD1 present in T-47D cells (IC50 = 0.31 and 0.21 µM for 5 and E1, respectively), and this negative effect was more obvious for E2 derivatives 6 and 10 (IC50 = 1.2 and 1.3 µM, respectively). Molecular docking allowed us to identify key interactions with 17ß-HSD1 and to highlight these new inhibitors' actions through an opposite orientation than natural enzyme substrate E1's classical one. Furthermore, molecular modeling experiments explain the better inhibitory activity of E1-ether derivative 5, as opposed to the E2-ether derivatives 6 and 10. Finally, when tested on T-47D and Z-12 cells, compounds 5, 6 and 10 did not stimulate the proliferation of these two estrogen-dependent cell lines. In fact, they reduced it.

Substituted Aryl Benzylamines as Potent and Selective Inhibitors of 17ß-Hydroxysteroid Dehydrogenase Type 3.

17ß-Hydroxysteroid dehydrogenase type 3 (17ß-HSD3) is expressed at high levels in testes and seminal vesicles; it is also present in prostate tissue and involved in gonadal and non-gonadal testosterone biosynthesis. The enzyme is membrane-bound, and a crystal structure is not yet available. Selective aryl benzylamine-based inhibitors were designed and synthesised as potential agents for prostate cancer therapeutics through structure-based design, using a previously built homology model with docking studies. Potent, selective, low nanomolar IC50 17ß-HSD3 inhibitors were discovered using N-(2-([2-(4-chlorophenoxy)phenylamino]methyl)phenyl)acetamide (1). The most potent compounds have IC50 values of approximately 75 nM. Compound 29, N-[2-(1-Acetylpiperidin-4-ylamino)benzyl]-N-[2-(4-chlorophenoxy)phenyl]acetamide, has an IC50 of 76 nM, while compound 30, N-(2-(1-[2-(4-chlorophenoxy)-phenylamino]ethyl)phenyl)acetamide, has an IC50 of 74 nM. Racemic C-allyl derivative 26 (IC50 of 520 nM) was easily formed from 1 in good yield and, to determine binding directionality, its enantiomers were separated by chiral chromatography. Absolute configuration was determined using single crystal X-ray crystallography. Only the S-(+)-enantiomer (32) was active with an IC50 of 370 nM. Binding directionality was predictable through our in silico docking studies, giving confidence to our model. Importantly, all novel inhibitors are selective over the type 2 isozyme of 17ß-HSD2 and show <20% inhibition when tested at 10 µM. Lead compounds from this series are worthy of further optimisation and development as inhibitors of testosterone production by 17ß-HSD3 and as inhibitors of prostate cancer cell growth.

Cloning and identification of a new repressor of 3,17ß-Hydroxysteroid dehydrogenase of Comamonas testosteroni.

BACKGROUND: 3,17ß-hydroxysteroid dehydrogenase (3,17ß-HSD) is a key enzyme in the metabolic pathway for steroid compounds catabolism in Comamonas testosteroni. Tetracycline repressor (TetR) family, repressors existing in most microorganisms, may play key roles in regulating the expression of 3,17ß-HSD. Previous reports showed that three tetR genes are located in the contig58 of C. testosteroni ATCC 11996 (GenBank: AHIL01000049.1), among which the first tetR gene encoded a potential repressor of 3,17ß-HSD by sensing environmental signals. However, whether the other proposed tetR genes act as repressors of 3,17ß-HSD are still unknown. METHODS AND RESULTS: In the present study, we cloned the second tetR gene and analyzed the regulatory mechanism of the protein on 3,17ß-HSD using electrophoretic mobility shift assay (EMSA), gold nanoparticles (AuNPs)-based assay, and loss-of-function analysis. The results showed that the second tetR gene was 660-bp, encoding a 26 kD protein, which could regulate the expression of 3,17ß-HSD gene via binding to the conserved consensus sequences located 1100-bp upstream of the 3,17ß-HSD gene. Furthermore, the mutant strain of C. testosteroni with the second tetR gene knocked-out mutant expresses good biological genetic stability, and the expression of 3,17ß-HSD in the mutant strain is slightly higher than that in the wild type under testosterone induction. CONCLUSIONS: The second tetR gene acts as a negative regulator in 3,17ß-HSD expression, and the mutant has potential application in bioremediation of steroids contaminated environment.

Synthesis of 16ß-derivatives of 3-(2-bromoethyl)-estra-1,3,5(10)-trien-17ß-ol as inhibitors of 17ß-HSD1 and/or steroid sulfatase for the treatment of estrogen-dependent diseases.

17ß-Hydroxysteroid dehydrogenase type 1 (17ß-HSD1) and steroid sulfatase (STS) are involved in the synthesis of the most potent estrogen in the human body, estradiol (E2). These enzymes are known to play a pivotal role in the progression of estrogen-dependent diseases, such as breast cancer and endometriosis. Therefore, the inhibition of 17ß-HSD1 and/or STS represents a promising avenue to modulate the growth of estrogen-dependent tumors or lesions. We recently established the key role of a bromoethyl side chain added at the C3-position of a 16ß-carbamoyl-benzyl-E2 nucleus to covalently inhibit 17ß-HSD1. To extend the structure-activity relationship study to the C16ß-position of this new selective irreversible inhibitor (PBRM), we synthesized a series of analog compounds by changing the nature of the C16ß-side chain but keeping the 2-bromoethyl group at position C3. We determined their 17ß-HSD1 inhibitions in T-47D cells (transformation of E1 into E2), but we did not obtain a stronger 17ß-HSD1 inhibitor than PBRM. Compounds 16 and 17 were found to be more likely to bind to the catalytic site and showed a promising but moderate inhibitory activity with estimated IC50 values of 0.5 and 0.7 µM, respectively (about 10 times higher than PBRM). Interestingly, adding one or two sulfamate groups in the D-ring's surroundings did not significantly decrease compounds' potential to inhibit 17ß-HSD1, but clearly improved their potential to inhibit STS. These results open the door to the development of a new family of steroid derivatives with dual (17ß-HSD1 and STS) inhibiting actions.

16-Picolyl-androsterone derivative exhibits potent 17ß-HSD3 inhibitory activity, improved metabolic stability and cytotoxic effect on various cancer cells: Synthesis, homology modeling and docking studies.

A new androsterone derivative bearing a 16ß-picolyl group (compound 5; FCO-586-119) was synthetized in four steps from the lead compound 1 (RM-532-105). We measured its inhibitory activity on 17ß-HSD3 using microsomal fraction of rat testes as well as transfected LNCaP[17ß-HSD3] cells. We then assessed its metabolic stability as well as its cytotoxic effect against a panel of cancer cell lines. The addition of a picolyl moiety at C-16 of RM-532-105 steroid core improves the 17ß-HSD3 inhibitory activity in the microsomal fraction of rat testes, but not in whole LNCaP[17ß-HSD3] cells. Interestingly, this structural modification enhances 3-fold the metabolic stability in conjunction with a significant cytotoxic effect against pancreatic, ovarian, breast, lung, and prostate cancer cells. Because the inhibitory activity data against 17ß-HSD3 suggested that both steroid derivatives are non-competitive inhibitors, we performed docking and molecular dynamics simulations using a homology model of this membrane-associated enzyme. The results of these simulations revealed that both RM-532-105 (1) and FCO-586-119 (5) can compete for the cofactor-binding site displaying better binding energy than NADP+.

Synthesis of 17ß-hydroxysteroid dehydrogenase type 10 steroidal inhibitors: Selectivity, metabolic stability and enhanced potency.

17beta-Hydroxysteroid dehydrogenase type 10 (17ß-HSD10) is the only mitochondrial member of 17ß-HSD family. This enzyme can oxidize estradiol (E2) into estrone (E1), thus reducing concentration of this neuroprotective steroid. Since 17ß-HSD10 possesses properties that suggest a possible role in Alzheimer's disease, its inhibition appears to be a therapeutic strategy. After we identified the androsterone (ADT) derivative 1 as a first steroidal inhibitor of 17ß-HSD10, new analogs were synthesized to increase the metabolic stability, to improve the selectivity of inhibition over 17ß-HSD3 and to optimize the inhibitory potency. From six D-ring derivatives of 1 (17-CO), two compounds (17ß-H/17α-OH and 17ß-OH/17α-CCH) were more metabolically stable and did not inhibit the 17ß-HSD3. Moreover, solid phase synthesis was used to extend the molecular diversity on the 3ß-piperazinylmethyl group of the steroid base core. Eight over 120 new derivatives were more potent inhibitors than 1 for the transformation of E2 to E1, with the 4-(4-trifluoromethyl-3-methoxybenzyl)piperazin-1-ylmethyl-ADT (D-3,7) being 16 times more potent (IC50 = 0.14 µM). Finally, D-ring modification of D-3,7 provided 17ß-OH/17α-CCH derivative 25 and 17ß-H/17α-OH derivative 26, which were more potent inhibitor than 1 (1.8 and 2.4 times, respectively).

Preclinical Pharmacokinetics, Tissue Distribution and Primary Safety Evaluation of a Novel Curcumin Analogue H10 Suspension, a Potential 17ß Hydroxysteroid Dehydrogenase Type 3 Inhibitor.

17ß Hydroxysteroid dehydrogenase type 3 (17ß-HSD3) is the key enzyme in the biosynthesis of testosterone, which is an attractive therapeutic target for prostate cancer (PCa). H10, a novel curcumin analogue, was identified as a potential 17ß-HSD3 inhibitor. The pharmacokinetic study of H10 in rats were performed by intraperitoneal (i.p.), intravenous (i.v.) and oral (p.o.) administration. In addition, the inhibitory effects of H10 against liver CYP3A4 were investigated in vitro using human liver microsomes (HLMs). The acute and chronic toxicological characteristics were characterized using single-dose and 30 d administration. All the mice were alive after i.p. H10 with dose of no more than 100 mg/kg which are nearly the maximum solubility in acute toxicity test. The pharmacokinetic characteristics of H10 fitted with linear dynamics model after single dose. Furthermore, H10 could bioaccumulate in testis, which was the target organ of 17ß-HSD3 inhibitor. H10 distributed highest in spleen, and then in liver both after single and multiple i.p. administration. Moreover, H10 showed weak inhibition towards liver CYP3A4, and did not cause significant changes in aspartate transaminase (AST) and alanine transaminase (ALT) levels after treated with H10 for continuously 30 d. Taken together, these preclinical characteristics laid the foundation for further clinical studies of H10.

N-Phenyl-1,2,3,4-tetrahydroisoquinoline: An Alternative Scaffold for the Design of 17ß-Hydroxysteroid Dehydrogenase 1 Inhibitors.

17ß-Hydroxysteroid dehydrogenases catalyse interconversion at the C17 position between oxidized and reduced forms of steroidal nuclear receptor ligands. The type 1 enzyme, expressed in malignant cells, catalyses reduction of the less-active estrone to estradiol, and inhibitors have therapeutic potential in estrogen-dependent diseases such as breast and ovarian cancers and in endometriosis. Synthetic decoration of the nonsteroidal N-phenyl-1,2,3,4-tetrahydroisoquinoline (THIQ) template was pursued by using Pomeranz-Fritsch-Bobbitt, Pictet-Spengler and Bischler-Napieralski approaches to explore the viability of this scaffold as a steroid mimic. Derivatives were evaluated biologically in vitro as type 1 enzyme inhibitors in a bacterial cell homogenate as source of recombinant protein. Structure-activity relationships are discussed. THIQs possessing a 6-hydroxy group, lipophilic substitutions at the 1- or 4-positions in combination with N-4'-chlorophenyl substitution were most favourable for activity. Of these, one compound had an IC50 of ca. 350 nM as a racemate, testifying to the applicability of this novel approach.

Effects of novel 17ß-hydroxysteroid dehydrogenase type 10 inhibitors on mitochondrial respiration.

Mitochondrial enzymes are targets of newly synthesized drugs being tested for the treatment of neurodegenerative disorders, such as Alzheimer's disease (AD). The enzyme 17ß-hydroxysteroid dehydrogenase type 10 (HSD10) is a multifunctional mitochondrial protein that is thought to play a role in the pathophysiology of AD and is one of the targets of new potential AD drugs. The in vitro effects of frentizole, riluzole, AG18051, and 42 novel modulators of HSD10 (potential AD drugs) on citrate synthase (CS) activity, monoamine oxidase (MAO) activity, complex I- or complex II-linked mitochondrial respiratory rate, and complex I activity were measured in isolated pig brain mitochondria. Based on their minimal inhibitory effects on the respiratory rate of mitochondria and CS and complex I activity, six novel compounds were selected for further testing. Assuming that inhibition of MAO-B could be a desirable effect of AD drugs, only AG18051 and one new compound met the criteria for MAO-B inhibition with minimal drug-induced effects on mitochondrial respiration. In conclusion, our in vitro screening of mitochondrial effect of novel potential AD drugs has enabled the selection of the most promising molecules for further testing that are relatively safe in terms of drug-induced mitochondrial toxicity.

Characterization of essential domains in HSD17B13 for cellular localization and enzymatic activity.

Human genetic studies recently identified an association of SNPs in the 17-ß hydroxysteroid dehydrogenase 13 (HSD17B13) gene with alcoholic and nonalcoholic fatty liver disease development. Mutant HSD17B13 variants devoid of enzymatic function have been demonstrated to be protective from cirrhosis and liver cancer, supporting the development of HSD17B13 as a promising therapeutic target. Previous studies have demonstrated that HSD17B13 is a lipid droplet (LD)-associated protein. However, the critical domains that drive LD targeting or determine the enzymatic activity have yet to be defined. Here we used mutagenesis to generate multiple truncated and point-mutated proteins and were able to demonstrate in vitro that the N-terminal hydrophobic domain, PAT-like domain, and a putative α-helix/ß-sheet/α-helix domain in HSD17B13 are all critical for LD targeting. Similarly, we characterized the predicted catalytic, substrate-binding, and homodimer interaction sites and found them to be essential for the enzymatic activity of HSD17B13, in addition to our previous identification of amino acid P260 and cofactor binding site. In conclusion, we identified critical domains and amino acid sites that are essential for the LD localization and protein function of HSD17B13, which may facilitate understanding of its function and targeting of this protein to treat chronic liver diseases.

A novel hybrid method named electron conformational genetic algorithm as a 4D QSAR investigation to calculate the biological activity of the tetrahydrodibenzazosines.

To understand the structure-activity correlation of a group of tetrahydrodibenzazocines as inhibitors of 17ß-hydroxysteroid dehydrogenase type 3, we have performed a combined genetic algorithm (GA) and four-dimensional quantitative structure-activity relationship (4D-QSAR) modeling study. The computed electronic and geometry structure descriptors were regulated as a matrix and named as electron-conformational matrix of contiguity (ECMC). A chemical property-based pharmacophore model was developed for series of tetrahydrodibenzazocines by EMRE software package. GA was employed to choose an optimal combination of parameters. A model has been developed for estimating anticancer activity quantitatively. All QSAR models were established with 40 compounds (training set), then they were considered for selective capability with additional nine compounds (test set). A statistically valid 4D-QSAR ( Rtraining2=0.856 , Rtest2=0.851 and q2 = 0.650) with good external set prediction was obtained.

Transcriptional coactivator with PDZ-binding motif suppresses the expression of steroidogenic enzymes by nuclear receptor 4 A1 in Leydig cells.

Transcriptional coactivator with PDZ-binding motif (TAZ) plays crucial role in maintaining testicular structure and function via regulation of senescence of spermatogenic cells. However, it remains unclear whether TAZ is involved in testosterone biosynthesis in testicular Leydig cells. We found that TAZ deficiency caused aberrant Leydig cell expansion and increased lipid droplet formation, which was significantly associated with increased lipogenic enzyme expression. Additionally, the expression of key steroidogenic enzymes, including steroidogenic acute regulatory protein, cytochrome P450 (CYP) 11A1, CYP17A1, and 3ß-hydroxysteroid dehydrogenase, was greatly increased in TAZ-deficient testes and primary Leydig cells. Interestingly, the transcriptional activity of nuclear receptor 4 A1 (NR4A1) was dramatically suppressed by TAZ; however, the protein expression and the subcellular localization of NR4A1 were not affected by TAZ. TAZ directly associated with the N-terminal region of NR4A1 and substantially suppressed its DNA-binding and transcriptional activities. Stable expression of TAZ in the mouse Leydig TM3 cell line decreased the expression of key steroidogenic enzymes, whereas knockdown of endogenous TAZ in TM3 cells increased transcripts of steroidogenic genes induced by NR4A1. Consistently, testosterone production was enhanced within TAZ-deficient Leydig cells. However, TAZ deficiency resulted in decreased testosterone secretion caused by dysfunctional mitochondria and lysosomes. Therefore, TAZ plays essential role in NR4A1-induced steroidogenic enzyme expression and testosterone production in Leydig cells.

The Footprints of Oxidative Stress and Mitochondrial Impairment in Arsenic Trioxide-Induced Testosterone Release Suppression in Pubertal and Mature F1-Male Balb/c Mice via the Downregulation of 3ß-HSD, 17ß-HSD, and CYP11a Expression.

Exposure to arsenic (AS) causes abnormalities in the reproductive system; however, the precise cellular pathway of AS toxicity on steroidogenesis in developing F1-male mice has not been clearly defined. In this study, paternal mice were treated with arsenic trioxide (As2O3; 0, 0.2, 2, and 20 ppm in drinking water) from 5 weeks before mating until weaning and continued for male offspring from weaning until maturity (in vivo). Additionally, Leydig cells (LCs) were isolated from the testes of sacrificed F1-intact mature male mice and incubated with As2O3 (0, 1, 10, and 100 µM) for 48 h (in vitro). Biomarkers of mitochondrial impairment, oxidative stress, and several steroidogenic genes, including the steroidogenic acute regulatory (StAR) protein, cytochrome P450 side-chain cleaving enzyme (P450scc; Cyp11a), 3ß-hydroxysteroid dehydrogenase (3ß-HSD), and 17ß-hydroxysteroid dehydrogenase (17ß-HSD), were evaluated. High doses of As2O3 interrupted testosterone (T) biosynthesis and T-related gene expression in these experimental models. Altogether, overconsumption of As2O3 can cause testicular and LC toxicity through mitochondrial-related pathways and oxidative stress indices as well as downregulation of androgenic-related genes in mice and isolated LCs. These results could lead to the development of preventive/therapeutic procedures against As2O3-induced reproductive toxicity. Graphical Abstract Mohammad Mehdi Ommati and Reza Heidari contributed equally to this study.

Mitochondrial dysfunction and Alzheimer's disease: prospects for therapeutic intervention.

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease and has become a major socioeconomic issue in many developed countries. Currently available therapeutic agents for AD provide only symptomatic treatments, mainly because the complete mechanism of the AD pathogenesis is still unclear. Although several different hypotheses have been proposed, mitochondrial dysfunction has gathered interest because of its profound effect on brain bioenergetics and neuronal survival in the pathophysiology of AD. Various therapeutic agents targeting the mitochondrial pathways associated with AD have been developed over the past decade. Although most of these agents are still early in the clinical development process, they are used to restore mitochondrial function, which provides an alternative therapeutic strategy that is likely to slow the progression of the disease. In this mini review, we will survey the AD-related mitochondrial pathways and their small-molecule modulators that have therapeutic potential. We will focus on recently reported examples, and also overview the current challenges and future perspectives of ongoing research. [BMB Reports 2020; 53(1): 47-55].