Estrogen Biosynthesis Research Articles

Aromatase Inhibitors as a Promising Direction for the Search for New Anticancer Drugs.

Aromatase is an enzyme that plays a crucial role in the biosynthesis of estrogens, which are hormones that contribute to the growth of certain types of breast cancer. In particular, aromatase catalyzes the conversion of androgens (male hormones) into estrogens (female hormones) in various tissues, including the adrenal glands, ovaries, and adipose tissue. Given the role of estrogen in promoting the growth of hormone-receptor-positive breast cancers, aromatase has become an important molecular target for the development of anticancer agents. Aromatase inhibitors can be classified into two main groups based on their chemical structure: steroidal and non-steroidal inhibitors. This work presents a review of the literature from the last ten years regarding the search for new aromatase inhibitors. We present the directions of search, taking into account the impact of structure modifications on anticancer activity.

Design, synthesis, molecular docking and in vitro anticancer activities of 1-(4-(benzamido)phenyl)-3-arylurea derivatives.

In both premenopausal and postmenopausal women, oestrogens play a critical role in the development of breast cancer. Aromatase is an enzyme that catalyses the final step in the biosynthesis of estrogen and has emerged as a promising target for therapeutic intervention. This study aimed to design and evaluate novel 1-(4-(benzamido)phenyl)-3-arylurea derivatives as potential aromatase inhibitors. Through molecular docking, promising leads were identified and synthesized. Spectroscopic techniques confirmed their structural integrity. Cytotoxicity against various cancer cell lines was assessed using MTT assay. Docking investigations against the aromatase enzyme (3s7s) elucidated binding interactions and energies. Compound 6g, exhibiting a binding energy of -8.6 kcal mol-1 and interacting with ALA306 and THR310 residues, showed the most promising activity. It demonstrated GI50 values ranging from 14.46 μM, 13.97 μM, 11.35 μM, 11.58 μM, and 15.77 μM against A-498, NCI-H23, MDAMB-231, MCF-7, and A-549 respectively. Lastly, the physicochemical, and ADMET properties of the compound were predicted. These findings highlight the potential of 1-(4-(benzamido)phenyl)-3-arylureas as a new class of antitumor agents targeting aromatase. Their versatility and superior activity compared to standard chemotherapeutic agents, like doxorubicin, warrant further investigation for the development of broader-spectrum anticancer drugs.

Gut microbiota affects the estrus return of sows by regulating the metabolism of sex steroid hormones

BackgroundSex hormones play important roles in the estrus return of post-weaning sows. Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota. However, the extent to which the gut microbiota affects estrus return of post-weaning sows is largely unknown.ResultsIn this study, we first screened 207 fecal samples from well-phenotyped sows by 16S rRNA gene sequencing and identified significant associations between microbes and estrus return of post-weaning sows. Using metagenomic sequencing data from 85 fecal samples, we identified 37 bacterial species that were significantly associated with estrus return. Normally returning sows were characterized by increased abundances of L. reuteri and P. copri and decreased abundances of B. fragilis, S. suis, and B. pseudolongum. The changes in gut microbial composition significantly altered the functional capacity of steroid hormone biosynthesis in the gut microbiome. The results were confirmed in a validation cohort. Significant changes in sex steroid hormones and related compounds were found between normal and non-return sows via metabolome analysis. An integrated analysis of differential bacterial species, metagenome, and fecal metabolome provided evidence that normal return-associated bacterial species L. reuteri and Prevotella spp. participated in the degradation of pregnenolone, progesterone, and testosterone, thereby promoting estrogen biosynthesis. Furthermore, the microbial metabolites related to sow energy and nutrient supply or metabolic disorders also showed relationships with sow estrus return.ConclusionsAn integrated analysis of differentially abundant bacterial species, metagenome, and fecal metabolome revealed the involvement of L. reuteri and Prevotella spp. in sow estrus return. These findings provide deep insight into the role of gut microbiota in the estrus return of post-weaning sows and the complex cross-talk between gut microbiota and sex hormones, suggesting that the manipulation of the gut microbiota could be an effective strategy to improve sow estrus return after weaning.

Stratification of Atherosclerosis based on Plasma Metabolic States.

Atherosclerosis is a dominant cause of cardiovascular disease (CVD), including myocardial infarction and stroke. To investigate metabolic states that are associated with the development of atherosclerosis. Cross-sectional cohort study at a university hospital in the Netherlands. A total of 302 adult subjects with a body mass index (BMI) ≥ 27 kg/m2 were included. We integrated plasma metabolomics with clinical metadata to quantify the "atherogenic state" of each individual, providing a continuous spectrum of atherogenic states that ranges between nonatherogenic states to highly atherogenic states. Analysis of groups of individuals with different clinical conditions-such as metabolically healthy individuals with obesity, and individuals with metabolic syndrome-confirmed the generalizability of this spectrum; revealed a wide variation of atherogenic states within each condition; and allowed identification of metabolites that are associated with the atherogenic state regardless of the particular condition, such as gamma-glutamyl-glutamic acid and homovanillic acid sulfate. The analysis further highlighted metabolic pathways such as catabolism of phenylalanine and tyrosine and biosynthesis of estrogens and phenylpropanoids. Using validation cohorts, we confirmed variation in atherogenic states in healthy subjects (before atherosclerosis plaques become visible), and showed that metabolites associated with the atherogenic state were also associated with future CVD. Our results provide a global view of atherosclerosis risk states using plasma metabolomics.

Identification of non-steroidal aromatase inhibitors via in-silico and in-vitro studies.

Breast cancer is the most common cancer affecting women worldwide, including Pakistan. More than half of breast cancer patients have hormone-dependent breast cancer, which is developed due to the over-production of estrogen (the main hormone in breast cancer). The biosynthesis of estrogen is catalyzed by the aromatase enzyme, which thus serves as a target for the treatment of breast cancer. During the current study, biochemical, computational, and STD-NMR methods were employed to identify new aromatase inhibitors. A series of phenyl-3-butene-2-one derivatives 1-9 were synthesized and evaluated for human placental aromatase inhibitory activity. Among them, four compounds 2, 3, 4, and 8 showed a moderate to weak inhibitory activity (IC50 = 22.6 - 47.9 µM), as compared to standard aromatase inhibitory drugs, letrozole (IC50 = 0.0147 ± 1.45 µM), anastrozole (IC50 = 0.0094 ± 0.91 µM), and exemestane (IC50 = 0.2 ± 0.032 µM). Kinetic studies on two moderate inhibitors, 4 and 8, revealed a competitive- and mixed-type of inhibition, respectively. Docking studies on all active compounds indicated their binding adjacent to the heme group and interaction with Met374, a critical residue of aromatase. STD-NMR further highlighted the interactions of these ligands with the aromatase enzyme. STD-NMR-based epitope mapping indicated close proximity of the alkyl chain followed by an aromatic ring with the receptor (aromatase). These compounds were also found to be non-cytotoxic against human fibroblast cells (BJ cells). Thus, the current study has identified new aromatase inhibitors (compounds 4, and 8) for further pre-clinical and clinical research.

Sex‐specific impact of brain estrogen deficiency on astrocyte reactivity, neurodegeneration, and memory loss in aromatase knockout mouse models

AbstractBackgroundNearly two‐thirds of Americans with Alzheimer’s disease (AD) are women, however, the molecular mechanisms underlying this sex difference in AD vulnerability remain unclear. Prior research has reported that women with AD have lower brain estrogen. Yet, how estrogen deficiency modulates this sex difference in AD is not well understood. Aromatase, the key enzyme for estrogen biosynthesis, is expressed in both neurons and astrocytes of the brain, with high levels in the hippocampus. To explore the underlying mechanism of estrogen deficiency in sex‐specific AD vulnerability, we generated mouse models with brain‐specific aromatase knockout (bArKO) and whole‐body total aromatase knockout (tArKO).MethodWe performed a series of memory and behavior tests including spontaneous alternation, social interaction, and tail suspension tests on 6‐ and 19‐month‐old bArKO and tArKO mice with both sexes (n = 10/group). Hippocampus tissues from these mice (n = 3∼4) were collected for bulk RNA‐seq and qPCR. Brain tissues (n = 5) were fixed and stained for astrocytes and neurons by immunofluorescence. Serum and tissue estrogen were measured using liquid chromatography‐mass spectrometry.ResultAromatase deletion decreased brain estrogen levels in bArKO mice and circulating and brain estrogen levels in tArKO mice. Impairments of spatial working memory and social interaction behavior were found in 19‐month‐old female bArKO and tArKO mice. Female tArKO mice also displayed depression‐like behavior at 6‐ and 19‐month‐old. The number of neurons in the CA1 region was significantly decreased in 19‐month‐old female (but not male) tArKO mice. Bulk RNA‐seq showed abnormal expression of genes associated with astrocyte reactivity (e.g., Gfap, Ctgf, Apoe, Lcn2, Sparc, Bdnf, Col1a1, Col1a2) only in aged female bArKO mice. Given growing evidence indicating a causal relationship between neurotoxic reactive astrocytes and neurodegeneration, this finding indicates brain estrogen deficiency triggering neurotoxic astrocyte reactivity in the hippocampus of aged female bArKO mice.ConclusionOur findings provide novel mechanisms that link estrogen deficiency to sex‐specific astrocyte reactivity in the hippocampus, and neurodegeneration and memory loss in aged female mice. Future studies will focus on defining impact of estrogen signaling deficiency on AD mouse models and identifying druggable targets to inform the development of new therapeutic strategies for the prevention and treatment of AD.

Characterization of emopamil binding protein (Cs-ebp) reveals its potential role in cholesterol biosynthesis and growth performance of Chinese tongue sole

Sexual size dimorphism (SSD) in Chinese tongue sole affects its annual yields and consequently hinders its sustainable aquaculture development. Females show faster growth rate than male from 6 month post hatch (m). Comparative transcriptome analysis suggested cholesterol biosynthesis as an important signaling pathway involved in Chinese tongue sole SSD. Emopamil-binding protein (EBP), identified as one of the differential expressed genes in females, is the key catalyzing enzyme in the final steps of cholesterol biosynthesis. In this study, Chinese tongue sole ebp (Cs-ebp) gene was characterized and its potential role in cholesterol biosynthesis and growth performance was assessed. Cs-ebp showed significant abundance in female ovaries and livers. Meanwhile, it was highly expressed in 6 m female ovaries compared to other developmental stages. Promoter analysis revealed that transcriptional factors JUNB (a subunit of the activating protein-1 transcription factor complex) and POU1F1α (Pou-homeodomain transcription factor) could promote Cs-ebp transcription. Cs-ebp gene knockdown triggered the down-regulation of its downstream genes in cholesterol biosynthesis pathway (sc5d, dhcr7, and dhcr24), and genes related to estrogen biosynthesis (cyp19a1a) and body growth (akt1 and bmp2b). All the results revealed that there might be crosstalk among Cs-ebp, PI3K/Akt, TGF-β/Bmp, and estrogen biosynthesis, eventually affected the growth performance of female Chinese tongue sole. Further investigation would provide us detailed information about the molecular mechanism beneath teleost SSD.

SIRT6 deficiency causes ovarian hypoplasia by affecting Plod1-related collagen formation.

SIRT6 is a key member of the mammalian sirtuin family of conserved nicotinamide adenine dinucleotide (NAD+ )-dependent deacetylases. Previous studies have shown that SIRT6 can regulate metabolism, DNA damage repair and aging. Ovarian aging process usually share similar mechanisms with general aging, which is characterized by decreases in both numbers of ovarian follicles and the quality of oocytes. It is reported that the expression level of SIRT6 was significantly decreased in the ovaries of aged mice, and the level of SIRT6 was positively correlated with ovarian reserve, indicating that SIRT6 may be potential markers of ovarian aging. However, its biological roles in follicular development are still unclear. Here, we explored the effect of SIRT6 on follicular development and found that ovarian development was interrupted in SIRT6 knockout (KO) mice, leading to disruptions of puberty and the estrus cycle, significant decreases in numbers of secondary and antral follicles, and decreased collagen in the ovarian stroma. Plod1, a lysyl hydroxylase that is vital for collagen crosslinking and deposition, was decreased at both the mRNA and protein levels in SIRT6-deficient ovaries and granulosa cells (GCs). Additionally, we found abnormal estrogen levels in both SIRT6 KO mice and SIRT6 KD GCs, accompanied by decreases in the levels of the estrogen biosynthesis genes Cyp11a1, Cyp19a1, Mgarp, and increases in the levels of TNF-α and NF-κB. These results confirmed the effect of SIRT6 on follicular development and revealed a possible molecular mechanism for SIRT6 involvement in follicular development via effects on estrogen biosynthesis and collagen formation.

Targeting estrogen signaling and biosynthesis for aged skin repair.

Non-healing skin wounds are disproportionally prevalent in older adults. Current treatments do not account for the particularities of aged skin and result in inadequate outcomes. Overall, healing chronic wounds in the elderly remains a major unmet clinical need. Estrogens play a critical role in reproduction but also have important actions in non-reproductive organs. Estrogen biosynthesis and signaling pathways are locally activated during physiological wound healing, processes that are inhibited in elderly estrogen-deprived skin. Estrogen deprivation has been shown to be a critical mediator of impaired wound healing in both postmenopausal women and aged men, and topical estrogen application reverses age-associated delayed wound healing in both elderly men and women. These data indicate that adequate estrogen biosynthesis and properly regulated estrogen signaling pathways are essential for normal wound healing and can be targeted to optimize tissue repair in the elderly. However, due to fundamental questions regarding how to safely restore estrogen signaling locally in skin wounds, there are currently no therapeutic strategies addressing estrogen deficiency in elderly chronic wounds. This review discusses established and recent literature in this area and proposes the hypothesis that estrogen plays a pleiotropic role in skin aging and that targeting estrogen signaling and biosynthesis could promote skin repair in older adults.

Aromatase inhibition and ketamine in rats: sex-differences in antidepressant-like efficacy

BackgroundKetamine has been recently approved to treat resistant depression; however preclinical studies showed sex differences in its efficacy. Sex steroids, such as estrogens and testosterone, both in the periphery and locally in the brain, are regarded as important modulators of these sex differences. Therefore, the present study evaluated how inhibiting the biosynthesis of estrogens with letrozole (an aromatase inhibitor) could affect the observed sex differences in ketamine's antidepressant-like-response.MethodsWe performed several consecutive studies in adult Sprague–Dawley rats to evaluate potential sex differences in the antidepressant-like effects of ketamine (5 mg/kg, 7 days, i.p.), letrozole (1 mg/kg, 8 days, i.p.) and their combination (letrozole pre-treatment 3 h before ketamine). Acute and repeated antidepressant-like responses were ascertained in a series of behavioral tests (forced-swim, novelty-suppressed feeding, two-bottle choice for sucrose preference).ResultsThe main results proved clear sex differences in the antidepressant-like response induced by ketamine, which was observed following a repeated paradigm in adult male rats, but rendered inefficacious in female rats. Moreover, decreasing estrogens production with letrozole induced on itself an antidepressant-like response in female rats, while also increased ketamine's response in male rats (i.e., quicker response observed after only a single dose). Interestingly, both the antidepressant-like effects induced by ketamine in male rats or letrozole in female rats persisted over time up to 65 days post-treatment, suggesting long-term sex-directed benefits for these drugs.ConclusionsThe present results demonstrated a sex-specific role for aromatase inhibition with letrozole in the antidepressant-like response induced by ketamine in male rats. Moreover, letrozole itself presented as a potential antidepressant for females with persistent effects over time. Clearly, the production of estrogens is key in modulating, in a sex-specific manner, affective-like responses and thus deserve further studies.

FRI613 Sex Differences In Human Islet Transcriptional Responses To Inflammation

Abstract Disclosure: K.L. Webster: None. W. Wu: None. B. Webb-Robertson: None. E. Nakayasu: None. S. Sarkar: None. C. Evans-Molina: None. S.A. Tersey: None. J. Enriquez: None. S.R. Hammes: None. R.G. Mirmira: None. Higher female incidence of autoimmune disease is often attributed to sex hormone-immune cell interactions or X chromosome immune genes escaping inactivation. Type 1 diabetes (T1D), however, occurs slightly more often in males, and studies show that female sex protects beta cell health under conditions of stress. It is now thought that beta cells themselves trigger loss of immune tolerance in T1D and that the state of beta cell differentiation and health dictates their susceptibility to autoimmunity. Here, we hypothesized that sex influences beta cell response to inflammation during T1D development. We utilized prior bulk RNA sequencing data on human islets from 10 donors (6 males, 4 females) treated for 18h with or without proinflammatory cytokines (PIC: IL-1b, IFNy) to mimic T1D inflammation. Hierarchical clustering grouped samples largely by PIC treatment but also by sex. To identify differentially expressed genes (DEGs) for each sex in response to PIC, we filtered for genes with fold change>1.5 and false discovery rate<0.05. A total of 3754 DEGs were detected in male islets with PIC treatment, while just 1117 were detected in female islets. Of these, 1016 genes were shared between sexes, and many related to cytokine signaling and immune responses. Only 101 DEGs were unique to females, and these were enriched in terms related to leukocyte aggregation, glutamate signaling, and responses to steroid hormone stimuli. 2738 DEGs unique to males were enriched in terms related to inflammation, NOTCH signaling, differentiation, and estrogen biosynthesis. Notably, the gene encoding double-stranded RNA sensor MDA5 (Ifih1), whose activity induces antiviral type I IFN responses and has been linked to T1D, showed a greater average increase with PIC in males (9.99-fold vs. 6.64-fold in females, p<0.05). By gene set enrichment analysis, control and PIC-treated female islets were enriched in differentiation and development pathways, while male islets were enriched in protein translation and steroid metabolism. To probe the role of sex steroid signaling in islet inflammatory response, we measured expression of Esr1 (encoding ERa) via qRT-PCR in mouse islets in response to PIC (IFNy, IL-1b, TNFa). In non-diabetic C57BL6/J mice, islets from both males and females increased Esr1 with PIC (3.63- and 4.39-fold, p<0.05). However, in pre-diabetic NOD mice, in which female mice are highly susceptible to autoimmune diabetes, islets from neither sex increased Esr1. Interestingly, islets from C57BL6/J mice of both sexes decreased expression of Ar (encoding androgen receptor) upon PIC treatment, a response also absent in NOD mice. These data suggested that Esr1 might be protective- and Ar detrimental- for beta cell function, but not in a sex-dependent manner. Collectively, these data demonstrate a sexual dimorphism in islet response to inflammation, with evidence of a more aggressive inflammatory response in males. Presentation: Friday, June 16, 2023

SAT429 Progesterone Secretion And The Estrous Cycle In The Mouse Are Disrupted By Mitochondrial Fusion Promoter M1 Injection During Proestrus

Abstract Disclosure: Y.P. Budi: None. M. Hsu: None. Y. Lin: None. Y. Lee: None. H. Chiu: None. C. Chiu: None. Y. Jiang: None. In the female reproductive system, mitochondria play a crucial role in steroid hormone synthesis. Literature reports on changes in mitochondrial dynamics throughout the ovarian cycle, but its role in the ovarian cycle is still unknown. In this study, a mitochondrial fusion promotor, M1, was used to study the impact of mitochondrial dynamics in the female reproductive system. The estrus cycle of mice was monitored before, during, and after the M1 treatment to test the impact of M1 on ovarian functions. Our results showed that M1 treatment in mice leads to the disruptions of estrous cycles in vagina smears. To observe the acute effects of M1, serum hormones level was observed, and the decrease in serum LH and progesterone was recorded in the animal. Similarly, our ovarian tissue culture also indicates inhibitions of progesterone secretion and ovulations. Although no significant changes in mitochondrial networks were observed in the ovaries, there was significant up-regulation of mitochondrial respiratory complexes in M1 treatments through transcriptomic analysis. In contrast to the estrogen and steroid biosynthesis up-regulated in M1, the extracellular matrix molecules, remodeling enzymes, and adhesion signaling decreased. Collectively, our study provides novel targets to regulate the ovarian cycles through the mitochondria. However, more studies are still necessary to provide the functional connections between mitochondria and the female reproductive system. Presentation: Saturday, June 17, 2023

Repurposing of approved drugs for targeting CDK4/6 and aromatase protein using molecular docking and molecular dynamics studies.

Breast cancer is a leading cause of cancer-related morbidity and mortality worldwide, with the highest incidence among women. Among the various subtypes of breast cancer, estrogen-receptor positive (ER+) is the most diagnosed. Estrogen upregulates cyclin D1, which in turn promotes the activity of CDK4/6 and facilitates cell cycle progression. To address this, the first-line treatment for ER+ breast cancer focuses on inhibiting estrogen production by targeting aromatase, the enzyme responsible for the rate-limiting step in estrogen synthesis. Thus, combining CDK4/6 inhibitors with aromatase inhibitors has emerged as a crucial treatment strategy for this type of breast cancer. This approach effectively suppresses estrogen biosynthesis and controls uncontrolled cell proliferation, significantly improving overall survival rates and delayed disease progression. This study aimed to identify compounds that are likely to inhibit CDK4/6 and aromatase simultaneously by using a structure-based drug design strategy. 12,432 approved and investigational drugs were prepared and docked into the active site of CDK6 using HTVS and XP docking modes of Glide resulting in 277 compounds with docking scores ≤ -7 kcal/mol. These compounds were docked into aromatase enzyme using XP mode to give seven drugs with docking scores≤ -6.001 kcal/mol. Furthermore, the shortlisted drugs were docked against CDK4 showing docking scores ranging from -3.254 to -8.254 kcal/mol. Moreover, MM-GBSA for the top seven drugs was calculated. Four drugs, namely ellagic acid, carazolol, dantron, and apomorphine, demonstrated good binding affinity to all three protein targets CDK4/6 and aromatase. Specifically, they exhibited favourable binding free energy with CDK6, with values of -51.92, -53.90, -50.22, and -60.97 kcal/mol, respectively. Among these drugs, apomorphine displayed the most favourable binding free energy with all three protein targets. To further evaluate the stability of the interaction, apomorphine was subjected to a 100 ns molecular dynamics simulation with CDK6. The results indicated the formation of a stable ligand-protein complex. While the results obtained from the MM-GBSA calculation of the binding free energies of the MD conformations of apomorphine showed less favourable binding free energy compared to that obtained post-docking. All these computational findings will provide better structural insight for the development of CDK4/6 and aromatase multi-target inhibitors.

Adipocyte regulation of cancer stem cells.

Cancer stem cells (CSCs) are a highly tumorigenic subpopulation of the cancer cells within a tumor that drive tumor initiation, progression, and therapy resistance. In general, stem cell niche provides a specific microenvironment in which stem cells are present in an undifferentiated and self-renewable state. CSC niche is a specialized tumor microenvironment for CSCs which provides cues for their maintenance and propagation. However, molecular mechanisms for the CSC-niche interaction remain to be elucidated. We have revealed that adipsin (complement factor D) and its downstream effector hepatocyte growth factor are secreted from adipocytes and enhance the CSC properties in breast cancers in which tumor initiation and progression are constantly associated with the surrounding adipose tissue. Considering that obesity, characterized by excess adipose tissue, is associated with an increased risk of multiple cancers, it is reasonably speculated that adipocyte-CSC interaction is similarly involved in many types of cancers, such as pancreas, colorectal, and ovarian cancers. In this review, various molecular mechanisms by which adipocytes regulate CSCs, including secretion of adipokines, extracellular matrix production, biosynthesis of estrogen, metabolism, and exosome, are discussed. Uncovering the roles of adipocytes in the CSC niche will propose novel strategies to treat cancers, especially those whose progression is linked to obesity.

Transcriptome characterization of gonadal sex differentiation in Pacific bluefin tuna, Thunnus orientalis (Temminck et Schlegel)

Tunas (genus Thunnus) are one of the most ecologically and commercially important fish worldwide. To establish a biological basis for reproduction in this globally essential species, we have recently studied crucial reproductive aspects of the Pacific bluefin tuna (T. orientalis; PBT), as a model of tuna species, based on our closed-cycle aquaculture technology. In this study, we clarified the global expression profile of the genes regulating gonadal sex differentiation in PBT, as this developmental process is vital to sexual reproduction. Based on the results of our comparative (RNA-sequencing) and temporal (qRT-PCR) transcriptome analyses using the updated genome dataset, we propose the molecular mechanisms of gonadal sex differentiation in PBT. In female gonads, foxl2 and cyp19a1a (coding aromatase) are expressed at the onset of sex differentiation. Active aromatase-mediated estrogen biosynthesis, which includes positive regulation of cyp19a1a expression by Foxl2, induces ovarian differentiation. By contrast, dmrt1 and gsdf are upregulated in differentiating male gonads lacking active estrogen synthesis. Dmrt1 and Gsdf would mainly promote testicular differentiation. Furthermore, androgen biosynthesis is upregulated in differentiating male gonad. Endogenous androgens may also be vital to testicular differentiation. This study provides the first comprehensive data clarifying the molecular basis for gonadal sex differentiation in tunas.

Aromatase Inhibition and Electroconvulsive Seizures in Adolescent Rats: Antidepressant and Long-Term Cognitive Sex Differences.

We recently showed sex differences in the antidepressant-like potential of electroconvulsive seizures (ECS) in adolescent rats; whereas it worked for male rats, it was inefficacious in females. Because sex steroids might be important modulators of these sex disparities, we evaluated the role of estrogens in the differential response induced by adolescent ECS. Moreover, given the literature suggesting certain cognitive sequelae from ECS exposure, we aimed at evaluating its long-term safety profile in adulthood. Adolescent Sprague-Dawley rats were pretreated with letrozole (1 mg/kg/day) or vehicle (1 mL/kg/day) for 8 days (i.p.) and treated during the last 5 days (3 hours later) with ECS (95 mA, 0.6 s, 100 Hz) or SHAM. Antidepressant-like responses were measured in the forced swim test, and long-term cognitive performance was assessed in the Barnes maze. During adolescence, whereas ECS alone exerted an antidepressant-like response in male rats, its combination with letrozole permitted ECS to also induce efficacy in females. Moreover, adolescent ECS treatment improved cognitive performance in adulthood although exclusively in male rats. Adolescent ECS demonstrated an antidepressant-like potential together with certain long-term beneficial cognitive effects but exclusively in male rats. For females, efficacy was restricted to a situation in which the biosynthesis of estrogens was reduced. Therefore, estrogens and/or testosterone levels play a crucial role in the sex disparities induced by ECS in Sprague-Dawley rats. Based on this study and on the literature supporting its safety, ECS should be encouraged for use in cases of treatment-resistant depression during adolescence, while adhering to sex-specific considerations.

Exploring Potential Non-steroidal Aromatase Inhibitors for Therapeutic Application against Estrogen-dependent Breast Cancer.

Breast cancer is one of the most commonly diagnosed cancer types among women worldwide. Cytochrome P450 aromatase (CYP19A1) is an enzyme in vertebrates that selectively catalyzes the biosynthesis of estrogens from androgenic precursors. Researchers have increasingly focused on developing non-steroidal aromatase inhibitors (NSAIs) for their potential clinical use, avoiding steroidal side effects. The objective of the present work is to search for potential lead compounds from the ZINC database through various in silico approaches. In the present study, compounds from the ZINC database were initially screened through receptor independent-based pharmacophore virtual screening. These screened molecules were subjected to several assessments, such as Lipinski rule of 5, SMART filtration, ADME prediction using SwissADME and lead optimization. Molecular docking was further applied to study the interaction of the filtered compounds with the active site of aromatase. Finally, the obtained hit compounds, consequently represented to be ideal lead candidates, were escalated to the MD simulations. The results indicated that the lead compounds might be potential anti-aromatase drug candidate. The findings provided a valuable approach in developing novel anti-aromatase inhibitors for the treatment of ER+ breast cancer.

The genomic landscape associated with resistance to aromatase inhibitors in breast cancer.

Aromatase inhibitors (AI) are drugs that are widely used in treating estrogen receptor (ER)-positive breast cancer patients. Drug resistance is a major obstacle to aromatase inhibition therapy. There are diverse reasons behind acquired AI resistance. This study aims at identifying the plausible cause of acquired AI resistance in patients administered with non-steroidal AIs (anastrozole and letrozole). We used genomic, transcriptomic, epigenetic, and mutation data of breast invasive carcinoma from The Cancer Genomic Atlas database. The data was then separated into sensitive and resistant sets based on patients' responsiveness to the non-steroidal AIs. A sensitive set of 150 patients and a resistant set of 172 patients were included for the study. These data were collectively analyzed to probe into the factors that might be responsible for AI resistance. We identified 17 differentially regulated genes (DEGs) among the two groups. Then, methylation, mutation, miRNA, copy number variation, and pathway analyses were performed for these DEGs. The top mutated genes (FGFR3, CDKN2A, RNF208, MAPK4, MAPK15, HSD3B1, CRYBB2, CDC20B, TP53TG5, and MAPK8IP3) were predicted. We also identified a key miRNA - hsa-mir-1264 regulating the expression of CDC20B. Pathway analysis revealed HSD3B1 to be involved in estrogen biosynthesis. This study reveals the involvement of key genes that might be associated with the development of AI resistance in ER-positive breast cancers and hence may act as a potential prognostic and diagnostic biomarker for these patients.

PARP2 promotes inflammation in psoriasis by modulating estradiol biosynthesis in keratinocytes

Poly(ADP-ribose) polymerase 2 (PARP2) alongside PARP1 are responsible for the bulk of cellular PARP activity, and they were first described as DNA repair factors. However, research in past decades implicated PARPs in biological functions as diverse as the regulation of cellular energetics, lipid homeostasis, cell death, and inflammation. PARP activation was described in Th2-mediated inflammatory processes, but studies focused on the role of PARP1, while we have little information on PARP2 in inflammatory regulation. In this study, we assessed the role of PARP2 in a Th17-mediated inflammatory skin condition, psoriasis. We found that PARP2 mRNA expression is increased in human psoriatic lesions. Therefore, we studied the functional consequence of decreased PARP2 expression in murine and cellular human models of psoriasis. We observed that the deletion of PARP2 attenuated the imiquimod-induced psoriasis-like dermatitis in mice. Silencing of PARP2 in human keratinocytes prevented their hyperproliferation, maintained their terminal differentiation, and reduced their production of inflammatory mediators after treatment with psoriasis-mimicking cytokines IL17A and TNFα. Underlying these observations, we found that aromatase was induced in the epidermis of PARP2 knock-out mice and in PARP2-deficient human keratinocytes, and the resulting higher estradiol production suppressed NF-κB activation, and hence, inflammation in keratinocytes. Steroidogenic alterations have previously been described in psoriasis, and we extend these observations by showing that aromatase expression is reduced in psoriatic lesions. Collectively, our data identify PARP2 as a modulator of estrogen biosynthesis by epidermal keratinocytes that may be relevant in Th17 type inflammation.Key messagesPARP2 mRNA expression is increased in lesional skin of psoriasis patients.PARP2 deletion in mice attenuated IMQ-induced psoriasis-like dermatitis.NF-κB activation is suppressed in PARP2-deficient human keratinocytes.Higher estradiol in PARP2-deficient keratinocytes conveys anti-inflammatory effect.

IN-SILICO SCREENING OF PHYTOCHEMICAL COMPOUNDS IN CAESALPINIA BONDUCELLA L. SEEDS AGAINST THE GENE TARGETS OF OVARIAN STEROIDOGENESIS PATHWAY

Polycystic ovary syndrome (PCOS) is the most common gynaecological disorder among reproductive-age women. Impaired metabolism of androgens and estrogens is one of the leading causes of PCOS. In India, medicinal herbs are being explored for their anti-androgenic and anti-estrogenic properties. In this study, we have screened the seed extracts of the herbal plant, Caesalpinia bonducella for potent inhibitors of estrogen and testosterone biosynthesis and assimilation. Methanol extract of C. bonducella seed kernels were subjected to gas chromatography - mass spectrometry (GC-MS) to identify the phytochemical constituents. Out of forty-three phytochemical compounds identified from the extract, eight compounds were selected based on Lipinski's rule of five for molecular docking. The selected phytochemical compounds were docked against specific targets of ovarian steroidogenesis pathway; human aromatase (CYP19A1), human 17β-hydroxysteroid dehydrogenase type 1 (HSD17B1), human androgen receptor and estrogen receptor α. Further, the nature of these compounds was validated using density functional theory (DFT) calculations and ADME/T studies. As per the molecular docking output, compounds 33, 35, 38, 40, and 43 exhibited higher binding affinities against the four selected targets. Phytochemical compounds were optimized using Gaussian 16 with the B3LYP function and the 6-31G(d, p) basis set and were correlated with docking results. ADME/T helps in identifying the potential drug candidates from a pool of drugs. Five phytochemical compounds, 33, 35, 38, 40, and 43 were found to have the ability to bind and inhibit appropriate targets in the ovarian steroidogenesis pathway. Hence, these compounds can be further characterized in vitro and in vivo for alleviating PCOS.