The nuclear receptor superfamily: the second decade

Genes Related to Motility in an Ionizing Radiation and Estrogen Breast Cancer Model

Breast cancer is a major global health concern as it is the primary cause of cancer death for women. Environmental radiation exposure and endogenous factors such as hormones increase breast cancer risk, and its development and spread depend on cell motility and migration. The expression of genes associated with cell motility, such as ADAM12, CYR61, FLRT2, SLIT2, VNN1, MYLK, MAP1B, and TUBA1A, was analyzed in an experimental breast cancer model induced by radiation and estrogen. The results showed that TUBA1A, SLIT2, MAP1B, MYLK, and ADAM12 gene expression increased in the irradiated Alpha3 cell line but not in the control or the malignant Tumor2 cell line. Bioinformatic analysis indicated that FLERT2, SLIT2, VNN1, MAP1B, MYLK, and TUBA1A gene expressions were found to be higher in normal tissue than in tumor tissue of breast cancer patients. However, ADAM12 and CYR61 expressions were found to be higher in tumors than in normal tissues, and they had a negative correlation with ESR1 gene expression. Concerning ESR2 gene expression, there was a negative correlation with CYR61, but there was a positive correlation with FLRT2, MYLK, MAP1B, and VNN1. Finally, a decreased survival rate was observed in patients exhibiting high expression levels of TUBA1A and MAP1B. These genes also showed a negative ER status, an important parameter for endocrine therapy. The genes related to motility were affected by ionizing radiation, confirming its role in the initiation process of breast carcinogenesis. In conclusion, the relationship between the patient's expression of hormone receptors and genes associated with cell motility presents a novel prospect for exploring therapeutic strategies.

Bile Acid Signaling in Metabolic and Inflammatory Diseases and Drug Development

Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates biliary secretion of lipids, endogenous metabolites, and xenobiotics. In intestine, bile acids facilitate the digestion and absorption of dietary lipids and fat-soluble vitamins. Through activation of nuclear receptors and G protein-coupled receptors and interaction with gut microbiome, bile acids critically regulate host metabolism and innate and adaptive immunity and are involved in the pathogenesis of cholestasis, metabolic dysfunction-associated steatotic liver disease, alcohol-associated liver disease, type-2 diabetes, and inflammatory bowel diseases. Bile acids and their derivatives have been developed as potential therapeutic agents for treating chronic metabolic and inflammatory liver diseases and gastrointestinal disorders. SIGNIFICANCE STATEMENT: Bile acids facilitate biliary cholesterol solubilization and dietary lipid absorption, regulate host metabolism and immunity, and modulate gut microbiome. Targeting bile acid metabolism and signaling holds promise for treating metabolic and inflammatory diseases.

Retinoid X receptor heterodimers in hepatic function: structural insights and therapeutic potential

Nuclear receptors (NRs) are key regulators of multiple physiological functions and pathological changes in the liver in response to a variety of extracellular signaling changes. Retinoid X receptor (RXR) is a special member of the NRs, which not only responds to cellular signaling independently, but also regulates multiple signaling pathways by forming heterodimers with various other NR. Therefore, RXR is widely involved in hepatic glucose metabolism, lipid metabolism, cholesterol metabolism and bile acid homeostasis as well as hepatic fibrosis. Specific activation of particular dimers regulating physiological and pathological processes may serve as important pharmacological targets. So here we describe the basic information and structural features of the RXR protein and its heterodimers, focusing on the role of RXR heterodimers in a number of physiological processes and pathological imbalances in the liver, to provide a theoretical basis for RXR as a promising drug target.

Extra-nuclear and cytoplasmic steroid receptor signalling in hormone dependent cancers

Steroid hormone receptors are key mediators in the execution of hormone action through a combination of genomic and non-genomic action. Since their isolation and characterisation in the early 20th Century much of our understanding of the biological actions of steroid hormones are underpinned by their activated receptor activity. Over the past two decades there has been an acceleration of more omics-based research which has resulted in a major uptick in our comprehension of genomic steroid action. However, it is well understood that steroid hormones can induce very rapid signalling events in tandem with their genomic actions wherein they exert their influence through alterations in gene expression. Thus the totality of genomic and non-genomic steroid action occurs in a simultaneous and reciprocal manner and a greater appreciation of whole cell action is required to fully evaluate steroid hormone activity in vivo. In this mini-review we outline the most recent developments in non-genomic steroid action and cytoplasmic steroid hormone receptor biology in endocrine-related cancers with a focus on the 3-keto steroid receptors, in particular the androgen receptor.

Discovering novel targets of abscisic acid using computational approaches

Abscisic acid (ABA) is a crucial plant hormone that is naturally produced in various mammalian tissues and holds significant potential as a therapeutic molecule in humans. ABA is selected for this study due to its known roles in essential human metabolic processes, such as glucose homeostasis, immune responses, cardiovascular system, and inflammation regulation. Despite its known importance, the molecular mechanism underlying ABA's action remain largely unexplored. This study employed computational techniques to identify potential human ABA receptors. We screened 64 candidate molecules using online servers and performed molecular docking to assess binding affinity and interaction types with ABA. The stability and dynamics of the best complexes were investigated using molecular dynamics simulation over a 100 ns time period. Root mean square fluctuations (RMSF), root mean square deviation (RMSD), solvent-accessible surface area (SASA), radius of gyration (Rg), free energy landscape (FEL), and principal component analysis (PCA) were analyzed. Next, the molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method was employed to calculate the binding energies of the complexes based on the simulated data. Our study successfully pinpointed four key receptors responsible for ABA signaling (androgen receptor, glucocorticoid receptor, mineralocorticoid receptor, and retinoic acid receptor beta) that have a strong affinity for binding with ABA and remained structurally stable throughout the simulations. The simulations with Hydralazine as an unrelated ligand were conducted to validate the specificity of the identified receptors for ABA. The findings of this study can contribute to further experimental validation and a better understanding of how ABA functions in humans.

Impact of different levels of handling on Solea senegalensis culture: effects on growth and molecular markers of stress

Aquaculture routine practices may cause stress induction on the fish and compromise their welfare affecting the production. This experiment aimed to evaluate the potential links between handling during culture with stress responses and growth on Senegalese sole (Solea senegalensis). We worked with two fish cohorts in terms of initial body weight and culture stage: Trial 1 included specimens in the fattening stage (226 ± 4.96 g) and Trial 2 animals in the pre-fattening stage (27.20 ± 0.44 g). The tested culture protocol, which lasted 6 and 4 months for Trial 1 and 2, respectively, mainly reduced handling-derived stressors in the experimental tanks via lowering routine samplings to a minimum. This decrease of the handling-derived stress was reflected in both trials with lower concentration of circulating cortisol in blood plasma from the experimental fish when compared to controls. Moreover, the proposed protocol promoted higher growth in the fish cultured in the less disturbing protocol in Trial 2. Higher specific growth rates and mean body weight and length were reported. In order to further explore the potential beneficial effects of our protocol, we studied the musculoskeletal from Trial 2 gene expression of key genes regulating glucocorticoid signaling pathway and apoptosis: glucocorticoid receptors 1 and 2 (gr1, gr2), heat shock protein 90 AA (hsp90aa), and caspase 6 (casp6). In line with the cortisol reduced level in this trial, gr1, hsp90aa, and casp6 genes showed lower expression in the samples coming from the experimental group. The findings of this study provide valuable information to the aquaculture industry for the management of Solea senegalensis stress and welfare.

Inhibitors of the transactivation domain of androgen receptor as a therapy for prostate cancer

The androgen receptor (AR) is a modular transcription factor which functions as a master regulator of gene expression. AR protein is composed of three functional domains; the ligand-binding domain (LBD); DNA-binding domain (DBD); and the intrinsically disordered N-terminal transactivation domain (TAD). AR is transactivated upon binding to the male sex hormone testosterone and other androgens. While the AR may tolerate loss of its LBD, the TAD contains activation function-1 (AF-1) that is essential for all AR transcriptional activity. AR is frequently over-expressed in most prostate cancer. Currently, androgen deprivation therapy (ADT) in the form of surgical or chemical castration remains the standard of care for patients with high risk localized disease, advanced and metastatic disease, and those patients that experience biochemical relapse following definitive primary treatment. Patients with recurrent disease that receive ADT will ultimately progress to lethal metastatic castration-resistant prostate cancer. In addition to ADT not providing a cure, it is associated with numerous adverse effects including cardiovascular disease, osteoporosis and sexual dysfunction. Recently there has been a renewed interest in investigating the possibility of using antiandrogens which competitively bind the AR-LBD without ADT for patients with hormone sensitive, non-metastatic prostate cancer. Here we describe a class of compounds termed AR transactivation domain inhibitors (ARTADI) and their mechanism of action. These compounds bind to the AR-TAD to inhibit AR transcriptional activity in the absence and presence of androgens. Thus these inhibitors may have utility in preventing prostate cancer growth in the non-castrate setting.

Tackling exosome and nuclear receptor interaction: an emerging paradigm in the treatment of chronic diseases

Nuclear receptors (NRs) function as crucial transcription factors in orchestrating essential functions within the realms of development, host defense, and homeostasis of body. NRs have garnered increased attention due to their potential as therapeutic targets, with drugs directed at NRs demonstrating significant efficacy in impeding chronic disease progression. Consequently, these pharmacological agents hold promise for the treatment and management of various diseases. Accumulating evidence emphasizes the regulatory role of exosome-derived microRNAs (miRNAs) in chronic inflammation, disease progression, and therapy resistance, primarily by modulating transcription factors, particularly NRs. By exploiting inflammatory pathways such as protein kinase B (Akt)/mammalian target of rapamycin (mTOR), nuclear factor kappa-B (NF-κB), signal transducer and activator of transcription 3 (STAT3), and Wnt/β-catenin signaling, exosomes and NRs play a pivotal role in the panorama of development, physiology, and pathology. The internalization of exosomes modulates NRs and initiates diverse autocrine or paracrine signaling cascades, influencing various processes in recipient cells such as survival, proliferation, differentiation, metabolism, and cellular defense mechanisms. This comprehensive review meticulously examines the involvement of exosome-mediated NR regulation in the pathogenesis of chronic ailments, including atherosclerosis, cancer, diabetes, liver diseases, and respiratory conditions. Additionally, it elucidates the molecular intricacies of exosome-mediated communication between host and recipient cells via NRs, leading to immunomodulation. Furthermore, it outlines the implications of exosome-modulated NR pathways in the prophylaxis of chronic inflammation, delineates current limitations, and provides insights into future perspectives. This review also presents existing evidence on the role of exosomes and their components in the emergence of therapeutic resistance.

The mrp-3 gene is involved in haem efflux and detoxification in a blood-feeding nematode

BACKGROUND

Haem is essential but toxic for metazoan organisms. Auxotrophic nematodes can acquire sufficient haem from the environment or their hosts in the meanwhile eliminate or detoxify excessive haem through tightly controlled machinery. In previous work, we reported a role of the unique transporter protein HRG-1 in the haem acquisition and homeostasis of parasitic nematodes. However, little is known about the haem efflux and detoxification via ABC transporters, particularly the multiple drug resistance proteins (MRPs).

RESULTS

Here, we further elucidate that a member of the mrp family (mrp-3) is involved in haem efflux and detoxification in a blood-feeding model gastrointestinal parasite, Haemonchus contortus. This gene is haem-responsive and dominantly expressed in the intestine and inner membrane of the hypodermis of this parasite. RNA interference of mrp-3 resulted in a disturbance of genes (e.g. hrg-1, hrg-2 and gst-1) that are known to be involved in haem homeostasis and an increased formation of haemozoin in the treated larvae and lethality in vitro, particularly when exposed to exogenous haem. Notably, the nuclear hormone receptor NHR-14 appears to be associated the regulation of mrp-3 expression for haem homeostasis and detoxification. Gene knockdown of nhr-14 and/or mrp-3 increases the sensitivity of treated larvae to exogenous haem and consequently a high death rate (> 80%).

CONCLUSIONS

These findings demonstrate that MRP-3 and the associated molecules are essential for haematophagous nematodes, suggesting novel intervention targets for these pathogens in humans and animals.

Morroniside attenuates podocytes lipid deposition in diabetic nephropathy: A network pharmacology, molecular docking and experimental validation study

BACKGROUND

Dysregulation of lipid metabolism is a key factor influencing the progression of diabetic nephropathy (DN). Morroniside (MOR) is a major active compound isolated from the traditional Chinese herb Cornus officinalis, our previous research found that it can improve the lipid deposition of renal tubular epithelial cells. The purpose of this study is to explore whether MOR can improve podocyte lipid deposition and its mechanism of reducing DN.

METHODS

Initially, we used network pharmacology and bioinformatics techniques to predict the relationship between renal lipid metabolism of MOR and DN. Subsequently, the binding activity of MOR with lipid-related proteins was studied by molecular docking to determine how MOR acts through these proteins. After determining the target of MOR, animal experiments and cell tests were carried out to verify it.

RESULTS

Using network pharmacology, bioinformatics, and molecular docking, target proteins for MOR treatment of DN were predicted and screened, including PGC-1α, LXRs, ABCA1, PPARY, CD36, and nephrin. It is particularly noted that MOR effectively binds to PGC-1α, while LXRs, ABCA1, PPARY and CD36 are downstream molecules of PGC-1α. Silencing the PGC-1α gene significantly reduced the therapeutic effects of MOR. Conversely, in groups without PGC-1α knockdown, MOR was able to increase the expression levels of PGC-1α and influence the expression of downstream proteins. Furthermore, through in vivo and in vitro experiments, utilizing techniques such as lipid droplet staining, PAS, MASSON staining, immunofluorescence, and Western blot, we found that MOR effectively elevated the expression levels of the podocyte protein nephrin and lipid metabolism-regulating proteins PGC-1α, PPARY, and ABCA1, while significantly inhibiting the expression of the lipid accumulation promoter CD36.

CONCLUSION

MOR can regulate the cholesterol efflux in podocytes via the PGC-1α/LXRs/ABCA1 signaling pathway, and control cholesterol intake via the PGC-1α/PPARY/CD36 signaling pathway, thereby ameliorating lipid deposition in DN.

Inhibitory effect of all-trans retinoic acid on ferroptosis in BeWo cells mediated by the upregulation of heme Oxygenase-1

INTRODUCTION

This study aimed to explore the association between ferroptosis, a newly identified type of cell death, and the role of retinoic acid in developing pregnancy complications. Therefore, the effects of all-trans retinoic acid (ATRA) on ferroptosis susceptibility in BeWo cells were assessed to understand abnormal placental development.

METHODS

BeWo cells were used as surrogates for cytotrophoblasts. The effect of ATRA on ferroptosis sensitivity was assessed on BeWo cells pretreated with ATRA or dimethyl sulfoxide (DMSO; control), following which the LDH-releasing assay was performed. The effects of ATRA pretreatment on the antioxidant defense system (including glutathione [GSH], mitochondrial membrane potential, and heme oxygenase-1 [HMOX1]) in BeWo cells were assessed using assay kits, RT-qPCR, and HMOX1 immunostaining. To evaluate the effect of ATRA on BeWo cells, HMOX1 was silenced in BeWo cells using shRNA.

RESULTS

ATRA pretreatment increased ferroptosis resistance in BeWo cells. Although with pretreatment, qPCR indicated upregulation of HMOX1, no significant change was observed in the GSH levels or mitochondrial membrane potential. This was corroborated by intensified immunostaining for heme oxygenase-1 protein (HO-1). Notably, the protective effect of ATRA against ferroptosis was negated when HO-1 was inhibited. Although HMOX1-silenced BeWo cells exhibited heightened ferroptosis sensitivity compared with controls, ATRA pretreatment counteracted ferroptosis in these cells.

DISCUSSION

ATRA pretreatment promotes BeWo cell viability by suppressing ferroptosis and upregulating HMOX1 and this can be used as a potential therapeutic strategy for addressing placental complications associated with ferroptosis.

Targeting Androgen, Thyroid Hormone, and Vitamin A and D Receptors to Treat Prostate Cancer

The nuclear hormone family of receptors regulates gene expression. The androgen receptor (AR), upon ligand binding and homodimerization, shuttles from the cytosol into the nucleus to activate gene expression. Thyroid hormone receptors (TRs), retinoic acid receptors (RARs), and the vitamin D receptor (VDR) are present in the nucleus bound to chromatin as a heterodimer with the retinoid X receptors (RXRs) and repress gene expression. Ligand binding leads to transcription activation. The hormonal ligands for these receptors play crucial roles to ensure the proper conduct of very many tissues and exert effects on prostate cancer (PCa) cells. Androgens support PCa proliferation and androgen deprivation alone or with chemotherapy is the standard therapy for PCa. RARγ activation and 3,5,3'-triiodo-L-thyronine (T3) stimulation of TRβ support the growth of PCa cells. Ligand stimulation of VDR drives growth arrest, differentiation, and apoptosis of PCa cells. Often these receptors are explored as separate avenues to find treatments for PCa and other cancers. However, there is accumulating evidence to support receptor interactions and crosstalk of regulatory events whereby a better understanding might lead to new combinatorial treatments.

Biochemical and structural characterization of the DNA-binding properties of human TRIP4 ASCH domain reveals insights into its functional role

TRIP4 is a conserved transcriptional coactivator that is involved in the regulation of the expression of multiple genes. It consists of a classical N-terminal C2HC5-like zinc-finger domain and a conserved C-terminal ASCH domain. Here, we characterized the DNA-binding properties of the human TRIP4 ASCH domain. Our biochemical data show that TRIP4-ASCH has comparable binding affinities toward ssDNA and dsDNA of different lengths, sequences, and structures. The crystal structures reveal that TRIP4-ASCH binds to DNA substrates in a sequence-independent manner through two adjacent positively charged surface patches: one binds to the 5'-end of DNA, and the other binds to the 3'-end of DNA. Further mutagenesis experiments and binding assays confirm the functional roles of key residues involved in DNA binding. In summary, our data demonstrate that TRIP4-ASCH binds to the 5' and 3'-ends of DNA in a sequence-independent manner, which will facilitate further studies of the biological function of TRIP4.

Association of Inflammation and Immune Cell Infiltration with Estrogen Receptor Alpha in an Estrogen and Ionizing Radiation-Induced Breast Cancer Model

Breast cancer is the most diagnosed cancer in the world, and it is the primary cause of cancer death for women. The risk of breast cancer is increased by endogenous factors like hormones and exogenous factors like radiation exposure that causes damage to the mammary epithelial cells leading to an inflammatory response. Chronic inflammation creates a microenvironment composed of, among other factors, chemokines, and interleukins, which promote cancer. The gene expression of the interleukin 1 receptor type 1, the interleukin 1 receptor antagonist, the Interleukin 1 Receptor Accessory Protein, the interleukin 6 cytokine family signal transducer, the C-X-C motif chemokine ligand 3, the C-X-C motif chemokine ligand 5, and the C-X-C motif chemokine ligand 6 were analyzed in an estrogen and radiation experimental breast cancer model. Furthermore, the expression of these genes was correlated with immune cell infiltration, estrogen receptor expression, and their clinical relevance in breast cancer patients based on data provided by The Cancer Genome Atlas database online. Results given by the experimental breast cancer model showed that all genes related to inflammation respond to ionizing radiation alone or in combination with estrogen. On the other hand, the immune response depended on the breast cancer type and on the expression of the gene that encoded the estrogen receptor. Finally, the importance of the expression of these genes in breast cancer is such that high IL1R1 or IL1RAP is strongly related to patient survival. These findings may help to improve the understanding of the role of immune molecules in carcinogenesis and enhance therapeutic approaches.

Genome-wide RNA interference of the nhr gene family in barber's pole worm identified members crucial for larval viability in vitro

Nuclear hormone receptors (NHRs) are emerging target candidates against nematode infection and resistance. However, there is a lack of comprehensive information on NHR-coding genes in parasitic nematodes. In this study, we curated the nhr gene family for 60 major parasitic nematodes from humans and animals. Compared with the free-living model organism Caenorhabditis elegans, a remarkable contraction of the nhr family was revealed in parasitic species, with genetic diversification and conservation unveiled among nematode Clades I (10-13), III (16-42), IV (33-35) and V (25-64). Using an in vitro biosystem, we demonstrated that 40 nhr genes in a blood-feeding nematode Haemonchus contortus (clade V; barber's pole worm) were responsive to host serum and one nhr gene (i.e., nhr-64) was consistently stimulated by anthelmintics (i.e., ivermectin, thiabendazole and levamisole); Using a high-throughput RNA interference platform, we knocked down 43 nhr genes of H. contortus and identified at least two genes that are required for the viability (i.e., nhr-105) and development (i.e., nhr-17) of the infective larvae of this parasitic nematode in vitro. Harnessing this preliminary functional atlas of nhr genes for H. contortus will prime the biological studies of this gene family in nematode genetics, infection, and anthelmintic metabolism within host animals, as well as the promising discovery of novel intervention targets.

Nuclear Receptors and the Hidden Language of the Metabolome

Nuclear hormone receptors (NHRs) are a family of ligand-regulated transcription factors that control key aspects of development and physiology. The regulation of NHRs by ligands derived from metabolism or diet makes them excellent pharmacological targets, and the mechanistic understanding of how NHRs interact with their ligands to regulate downstream gene networks, along with the identification of ligands for orphan NHRs, could enable innovative approaches for cellular engineering, disease modeling and regenerative medicine. We review recent discoveries in the identification of physiologic ligands for NHRs. We propose new models of ligand-receptor co-evolution, the emergence of hormonal function and models of regulation of NHR specificity and activity via one-ligand and two-ligand models as well as feedback loops. Lastly, we discuss limitations on the processes for the identification of physiologic NHR ligands and emerging new methodologies that could be used to identify the natural ligands for the remaining 17 orphan NHRs in the human genome.

Nuclear receptors in ovarian cancer: changing paradigms in cancer therapeutics

Ovarian cancer (OVC) is one of the most common causes of cancer-related deaths in women worldwide. Despite advancements in detection and therapy, the prognosis of OVC remains poor due to late diagnosis and the lack of effective therapeutic options at advanced stages. Therefore, a better understanding of the biology underlying OVC is essential for the development of effective strategies for early detection and targeted therapies. Nuclear receptors (NRs) are a superfamily of 48 transcription factors that, upon binding to their specific ligand, play a vital role in regulating various cellular processes such as growth, development, metabolism, and homeostasis. Accumulating evidence from several studies has shown that their aberrant expression is associated with multiple human diseases. Numerous NRs have shown significant effects in the development of various cancers, including OVC. This review summarizes the recent findings on the role of NRs in OVC, as well as their potential as prognostic and therapeutic markers. Further, the basic structure and signaling mechanism of NRs have also been discussed briefly. Moreover, this review highlights their cellular and molecular mechanisms in chemoresistance and chemosensitization. Further, the clinical trials targeting NRs for the treatment of OVC have also been discussed.

Efficient synthesis of some [1,3]-oxazine derivatives in the presence of solid acid nano catalyst based on ferrierite and study on their activity against breast cancer through molecular docking calculation

In this research, the magnetic solid acid nanocatalyst based on ferrierite has been prepared and used as catalyst for the green synthesis of some [1,3]-oxazine derivatives in water at room temperature. The synthesized compounds were obtained in high to excellent yields after short reaction times and the structure of synthesized products were investigated by spectroscopic methods such as: FT-IR, 1H NMR and 13C NMR. The prepared magnetic solid acid catalyst was characterized using XRD, FT-IR, FE-SEM, EDX, elemental mapping, TGA and VSM analysis methods. Magnetic catalyst has easy separation ability, which leads to better and easier recycling. The preparation and synthesis of [1,3]-oxazine derivatives were carried out at room temperature in the presence of M-FER/TEPA/SO3H. Easy workup, green solvent (water) and also short reaction times with high to excellent yield of products, are some of advantageous of presented method. Docking calculations on the structure of the synthesized compounds proved their medicinal properties against breast cancer cells.

Visfatin (NAMPT) affects global gene expression in porcine anterior pituitary cells during the mid-luteal phase of the oestrous cycle

BACKGROUND

The pituitary belongs to the most important endocrine glands involved in regulating reproductive functions. The proper functioning of this gland ensures the undisturbed course of the oestrous cycle and affects the female's reproductive potential. It is believed that visfatin, a hormone belonging to the adipokine family, may regulate reproductive functions in response to the female's metabolic state. Herein we verified the hypothesis that suggests a modulatory effect of visfatin on the anterior pituitary transcriptome during the mid-luteal phase of the oestrous cycle.

RESULTS

RNA-seq analysis of the porcine anterior pituitary cells revealed changes in the expression of 202 genes (95 up-regulated and 107 down-regulated in the presence of visfatin, when compared to the non-treated controls), assigned to 318 gene ontology terms. We revealed changes in the frequency of alternative splicing events (235 cases), as well as long noncoding RNA expression (79 cases) in the presence of the adipokine. The identified genes were associated, among others, with reproductive system development, epithelial cell proliferation, positive regulation of cell development, gland morphogenesis and cell chemotaxis.

CONCLUSIONS

The obtained results indicate a modulatory influence of visfatin on the regulation of the porcine transcriptome and, in consequence, pituitary physiology during the mid-luteal phase of the oestrous cycle.

Structural mechanism underlying variations in DNA binding by the androgen receptor

The androgen receptor (AR) is a steroid activated transcription factor which recognizes DNA motifs resembling inverted repeats of a conserved 5'-AGAACA-3'-like hexanucleotides separated by a three-nucleotide spacer from a similar, but less conserved hexanucleotide. Here, we report the structures of the human AR DNA binding domain (DBD) bound to two natural AREs (C3 and MTV) in head-to-head dimer conformations, diffracting at 2.05 Å and 2.25 Å, respectively. These structures help to explain the impact of androgen insensitivity mutations on the structure integrity, DNA binding and DBD dimerization. The binding affinity of the AR DBD to different DNA motifs were measured by the BioLayer Interferometry (BLI) and further validated by Molecular Dynamics (MD) simulations. This shows that the high binding affinity of the first DBD to the upstream 5'-AGAACA-3' motif induces the cooperative binding of the second DBD to the second hexanucleotide. Our data indicate identical interaction of the DBDs to the upstream hexanucleotides, while forming an induced closer contact of the second DBD on the non-canonical hexanucleotides. The variation in binding between the DBD monomers are the result of differences in DNA occupancy, protein-protein interactions, DNA binding affinity, and DNA binding energy profiles. We propose this has functional consequences.

Hydroboration of vinylsilanes providing diversity-oriented hydrophobic building blocks for biofunctional molecules

Hydroboration of vinylsilanes with BH3 affords two silylethanol regioisomers. Herein, we investigated the regioisomeric ratio of hydroboration products from various vinylsilanes, focusing on the characteristic reaction profile. All investigated vinylsilanes afforded both regioisomers, and greater bulkiness increased the proportion of the Markovnikov products. The obtained silylethanols were used as hydrophobic building blocks for constructing nuclear progesterone receptor (PR) modulators. Notably, structural conversions from an α-isomer (silylethan-1-oxy derivative) to a β-isomer (2-silylethoxy derivative) caused complete activity-switching from a PR agonist to an antagonist. Our results indicate that silylethanols are useful for structural development, and vinylsilanes are a versatile source of hydrophobic building blocks for obtaining biofunctional molecules.

A History of Cancer Research: Oncogenic Transcription Factors

Transcription factors play crucial roles in cancer, and oncogenic counterparts of cellular transcription factors are present in a number of tumor viruses. It was studies in the early 1980s that first showed tumor viruses could encode nuclear as well as cytoplasmic oncoproteins. Subsequent work provided detailed insight into their mechanisms of action, as well as potential therapeutic avenues. In this excerpt from his forthcoming book on the history of cancer research, Joe Lipsick looks back at early work on nuclear oncogenes, including the discovery of MYC, MYB, FOS and JUN, Rel/NF-κB, and nuclear receptors such as the retinoic acid receptor and thyroid hormone receptor.

The olfactory bulb: A neuroendocrine spotlight on feeding and metabolism

Olfaction is the most ancient sense and is needed for food-seeking, danger protection, mating and survival. It is often the first sensory modality to perceive changes in the external environment, before sight, taste or sound. Odour molecules activate olfactory sensory neurons that reside on the olfactory epithelium in the nasal cavity, which transmits this odour-specific information to the olfactory bulb (OB), where it is relayed to higher brain regions involved in olfactory perception and behaviour. Besides odour processing, recent studies suggest that the OB extends its function into the regulation of food intake and energy balance. Furthermore, numerous hormone receptors associated with appetite and metabolism are expressed within the OB, suggesting a neuroendocrine role outside the hypothalamus. Olfactory cues are important to promote food preparatory behaviours and consumption, such as enhancing appetite and salivation. In addition, altered metabolism or energy state (fasting, satiety and overnutrition) can change olfactory processing and perception. Similarly, various animal models and human pathologies indicate a strong link between olfactory impairment and metabolic dysfunction. Therefore, understanding the nature of this reciprocal relationship is critical to understand how olfactory or metabolic disorders arise. This present review elaborates on the connection between olfaction, feeding behaviour and metabolism and will shed light on the neuroendocrine role of the OB as an interface between the external and internal environments. Elucidating the specific mechanisms by which olfactory signals are integrated and translated into metabolic responses holds promise for the development of targeted therapeutic strategies and interventions aimed at modulating appetite and promoting metabolic health.

Impact of pemafibrate on lipid profile and insulin resistance in hypertriglyceridemic patients with coronary artery disease and metabolic syndrome

This study examined the effects of pemafibrate, a selective peroxisome proliferator-activated receptor α agonist, on the serum biochemical parameters of male patients with coronary artery disease and metabolic syndrome (MetS). This was a post hoc analysis of a randomized, crossover study that treated hypertriglyceridemia with pemafibrate or bezafibrate for 24 weeks, followed by a crossover of another 24 weeks. Of the 60 patients enrolled in the study, 55 were male. Forty-one of 55 male patients were found to have MetS. In this sub-analysis, male patients with MetS (MetS group, n = 41) and those without MetS (non-MetS group, n = 14) were compared. The primary endpoint was a change in fasting serum triglyceride (TG) levels during pemafibrate therapy, and the secondary endpoints were changes in insulin resistance-related markers and liver function parameters. Serum TG levels significantly decreased (MetS group, from 266.6 to 148.0 mg/dL, p < 0.001; non-MetS group, from 203.9 to 97.6 mg/dL, p < 0.001); however, a percent change (%Change) was not significantly different between the groups (- 44.1% vs. - 51.6%, p = 0.084). Serum insulin levels and homeostasis model assessment of insulin resistance significantly decreased in the MetS group but not in the non-MetS group. %Change in liver enzyme levels was markedly decreased in the MetS group compared with that in the non-MetS group (alanine aminotransferase, - 25.1% vs. - 11.3%, p = 0.027; gamma-glutamyl transferase, - 45.8% vs. - 36.2%, p = 0.020). In conclusion, pemafibrate can effectively decrease TG levels in patients with MetS, and it may be a more efficient drug for improving insulin resistance and liver function in such patients.

Defining a vitamin A5/X specific deficiency - vitamin A5/X as a critical dietary factor for mental health

A healthy and balanced diet is an important factor to assure a good functioning of the central and peripheral nervous system. Retinoid X receptor (RXR)-mediated signaling was identified as an important mechanism of transmitting major diet-dependent physiological and nutritional signaling such as the control of myelination and dopamine signalling. Recently, vitamin A5/X, mainly present in vegetables as provitamin A5/X, was identified as a new concept of a vitamin which functions as the nutritional precursor for enabling RXR-mediated signaling. The active form of vitamin A5/X, 9-cis-13,14-dehydroretinoic acid (9CDHRA), induces RXR-activation, thereby acting as the central switch for enabling various heterodimer-RXR-signaling cascades involving various partner heterodimers like the fatty acid and eicosanoid receptors/peroxisome proliferator-activated receptors (PPARs), the cholesterol receptors/liver X receptors (LXRs), the vitamin D receptor (VDR), and the vitamin A(1) receptors/retinoic acid receptors (RARs). Thus, nutritional supply of vitamin A5/X might be a general nutritional-dependent switch for enabling this large cascade of hormonal signaling pathways and thus appears important to guarantee an overall organism homeostasis. RXR-mediated signaling was shown to be dependent on vitamin A5/X with direct effects for beneficial physiological and neuro-protective functions mediated systemically or directly in the brain. In summary, through control of dopamine signaling, amyloid β-clearance, neuro-protection and neuro-inflammation, the vitamin A5/X - RXR - RAR - vitamin A(1)-signaling might be "one of" or even "the" critical factor(s) necessary for good mental health, healthy brain aging, as well as for preventing drug addiction and prevention of a large array of nervous system diseases. Likewise, vitamin A5/X - RXR - non-RAR-dependent signaling relevant for myelination/re-myelination and phagocytosis/brain cleanup will contribute to such regulations too. In this review we discuss the basic scientific background, logical connections and nutritional/pharmacological expert recommendations for the nervous system especially considering the ageing brain.

Illuminating ligand-induced dynamics in nuclear receptors through MD simulations

Nuclear receptors (NRs) regulate gene expression in critical physiological processes, with their functionality finely tuned by ligand-induced conformational changes. While NRs may sometimes undergo significant conformational motions in response to ligand-binding, these effects are more commonly subtle and challenging to study by traditional structural or biophysical methods. Molecular dynamics (MD) simulations are a powerful tool to bridge the gap between static protein-ligand structures and dynamical changes that govern NR function. Here, we summarize a handful of recent studies that apply MD simulations to study NRs. We present diverse methodologies for analyzing simulation data with a detailed examination of the information each method can yield. By delving into the strengths, limitations and unique contributions of these tools, this review provides guidance for extracting meaningful data from MD simulations to advance the goal of understanding the intricate mechanisms by which ligands orchestrate a range of functional outcomes in NRs.

A combined in vitro-in silico method for assessing the androgenic activities of bisphenol A and its analogues

Interactions between endocrine-disruptor chemicals (EDCs) and androgen receptor (AR) have adverse effects on the endocrine system, leading to human reproductive dysfunction. Bisphenol A (BPA) is an EDC that can damage both the environment and human health. Although numerous BPA analogues have been produced as substitutes for BPA, few studies have evaluated their endocrine-disrupting abilities. We assessed the (anti)-androgenic activities of BPA and its analogues using a yeast-based reporter assay. The BPA analogues tested were bisphenol S (BPS), 4-phenylphenol (4PP), 4,4'-(9-fluorenyliden)-diphenol (BPFL), tetramethyl bisphenol F (TMBPF), and tetramethyl bisphenol A (TMBPA). We also conducted molecular docking and dynamics simulations to assess the interactions of BPA and its analogues with the ligand-binding domain of human AR (AR-LBD). Neither BPA nor its analogues had androgenic activity; however, all except BPFL exerted robust anti-androgenic effects. Consistent with the in vitro results, anti-androgenic analogues of BPA formed hydrogen bonding patterns with key residues that differed from the patterns of endogenous hormones, indicating that the analogues display in inappropriate orientations when interacting with the binding pocket of AR-LBD. Our findings indicate that BPA and its analogues disrupt androgen signaling by interacting with the AR-LBD. Overall, BPA and its analogues display endocrine-disrupting activity, which is mediated by AR.

Diagnosis and management of non-CAH 46,XX disorders/differences in sex development

Prenatal-onset androgen excess leads to abnormal sexual development in 46,XX individuals. This androgen excess can be caused endogenously by the adrenals or gonads or by exposure to exogenous androgens. The most common cause of 46,XX disorders/differences in sex development (DSD) is congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, comprising >90% of 46,XX DSD cases. Deficiencies of 11β-hydroxylase, 3β-hydroxysteroid dehydrogenase, and P450-oxidoreductase (POR) are rare types of CAH, resulting in 46,XX DSD. In all CAH forms, patients have normal ovarian development. The molecular genetic causes of 46,XX DSD, besides CAH, are uncommon. These etiologies include primary glucocorticoid resistance (PGCR) and aromatase deficiency with normal ovarian development. Additionally, 46,XX gonads can differentiate into testes, causing 46,XX testicular (T) DSD or a coexistence of ovarian and testicular tissue, defined as 46,XX ovotesticular (OT)-DSD. PGCR is caused by inactivating variants in NR3C1, resulting in glucocorticoid insensitivity and the signs of mineralocorticoid and androgen excess. Pathogenic variants in the CYP19A1 gene lead to aromatase deficiency, causing androgen excess. Many genes are involved in the mechanisms of gonadal development, and genes associated with 46,XX T/OT-DSD include translocations of the SRY; copy number variants in NR2F2, NR0B1, SOX3, SOX9, SOX10, and FGF9, and sequence variants in NR5A1, NR2F2, RSPO1, SOX9, WNT2B, WNT4, and WT1. Progress in cytogenetic and molecular genetic techniques has significantly improved our understanding of the etiology of non-CAH 46,XX DSD. Nonetheless, uncertainties about gonadal function and gender outcomes may make the management of these conditions challenging. This review explores the intricate landscape of diagnosing and managing these conditions, shedding light on the unique aspects that distinguish them from other types of DSD.

Androgen receptor activity inversely correlates with immune cell infiltration and immunotherapy response across multiple cancer lineages

There is now increasing recognition of the important role of androgen receptor (AR) in modulating immune function. To gain a comprehensive understanding of the effects of AR activity on cancer immunity, we employed a computational approach to profile AR activity in 33 human tumor types using RNA-Seq datasets from The Cancer Genome Atlas. Our pan-cancer analysis revealed that the genes most negatively correlated with AR activity across cancers are involved in active immune system processes. Importantly, we observed a significant negative correlation between AR activity and IFNγ pathway activity at the pan-cancer level. Indeed, using a matched biopsy dataset from subjects with prostate cancer before and after AR-targeted treatment, we verified that inhibiting AR enriches immune cell abundances and is associated with higher IFNγ pathway activity. Furthermore, by analyzing immunotherapy datasets in multiple cancers, our results demonstrate that low AR activity was significantly associated with a favorable response to immunotherapy. Together, our data provide a comprehensive assessment of the relationship between AR signaling and tumor immunity.

Structure-Activity Relationships and Therapeutic Applications of Retinoids in View of Potential Benefits from Drug Repurposing Process

Vitamin A, an essential micronutrient, is integral to various biological processes crucial for organismal development and maintenance. Dietary sources of vitamin A encompass preformed retinol, retinyl esters, and provitamin A carotenoids. Retinoic acid (RA), a key component, plays pivotal roles in vision, cell proliferation, apoptosis, immune function, and gene regulation. Drug repurposing, an effective strategy for identifying new therapeutic applications for existing drugs, has gained prominence in recent years. This review seeks to provide a comprehensive overview of the current research landscape surrounding retinoids and drug repurposing. The scope of this review encompasses a comprehensive examination of retinoids and their potential for repurposing in various therapeutic contexts. Despite their efficacy in treating dermatological conditions, concerns about toxicity persist, driving the search for safer and more potent retinoids. The molecular mechanisms underlying retinoid activity involve binding to retinoic acid receptors (RARs) and retinoid X receptors (RXRs), leading to transcriptional regulation of target genes. This review seeks to shed light on the possibilities for repurposing retinoids to cover a wider spectrum of therapeutic uses by exploring recent scientific progress. It also aims to offer a more comprehensive understanding of the therapeutic prospects of retinoids and the broader impact of drug repositioning in contemporary medicine.

Cardiac GR Mediates the Diurnal Rhythm in Ventricular Arrhythmia Susceptibility

BACKGROUND

Ventricular arrhythmias (VAs) demonstrate a prominent day-night rhythm, commonly presenting in the morning. Transcriptional rhythms in cardiac ion channels accompany this phenomenon, but their role in the morning vulnerability to VAs and the underlying mechanisms are not understood. We investigated the recruitment of transcription factors that underpins transcriptional rhythms in ion channels and assessed whether this mechanism was pertinent to the heart's intrinsic diurnal susceptibility to VA.

METHODS AND RESULTS

Assay for transposase-accessible chromatin with sequencing performed in mouse ventricular myocyte nuclei at the beginning of the animals' inactive (ZT0) and active (ZT12) periods revealed differentially accessible chromatin sites annotating to rhythmically transcribed ion channels and distinct transcription factor binding motifs in these regions. Notably, motif enrichment for the glucocorticoid receptor (GR; transcriptional effector of corticosteroid signaling) in open chromatin profiles at ZT12 was observed, in line with the well-recognized ZT12 peak in circulating corticosteroids. Molecular, electrophysiological, and in silico biophysically-detailed modeling approaches demonstrated GR-mediated transcriptional control of ion channels (including Scn5a underlying the cardiac Na+ current, Kcnh2 underlying the rapid delayed rectifier K+ current, and Gja1 responsible for electrical coupling) and their contribution to the day-night rhythm in the vulnerability to VA. Strikingly, both pharmacological block of GR and cardiomyocyte-specific genetic knockout of GR blunted or abolished ion channel expression rhythms and abolished the ZT12 susceptibility to pacing-induced VA in isolated hearts.

CONCLUSIONS

Our study registers a day-night rhythm in chromatin accessibility that accompanies diurnal cycles in ventricular myocytes. Our approaches directly implicate the cardiac GR in the myocyte excitability rhythm and mechanistically link the ZT12 surge in glucocorticoids to intrinsic VA propensity at this time.

Lineage-determining transcription factor-driven promoters regulate cell type-specific macrophage gene expression

Mammalian promoters consist of multifarious elements, which make them unique and support the selection of the proper transcript variants required under diverse conditions in distinct cell types. However, their direct DNA-transcription factor (TF) interactions are mostly unidentified. Murine bone marrow-derived macrophages (BMDMs) are a widely used model for studying gene expression regulation. Thus, this model serves as a rich source of various next-generation sequencing data sets, including a large number of TF cistromes. By processing and integrating the available cistromic, epigenomic and transcriptomic data from BMDMs, we characterized the macrophage-specific direct DNA-TF interactions, with a particular emphasis on those specific for promoters. Whilst active promoters are enriched for certain types of typically methylatable elements, more than half of them contain non-methylatable and prototypically promoter-distal elements. In addition, circa 14% of promoters-including that of Csf1r-are composed exclusively of 'distal' elements that provide cell type-specific gene regulation by specialized TFs. Similar to CG-rich promoters, these also contain methylatable CG sites that are demethylated in a significant portion and show high polymerase activity. We conclude that this unusual class of promoters regulates cell type-specific gene expression in macrophages, and such a mechanism might exist in other cell types too.

Bile acid and nonalcoholic steatohepatitis: Molecular insights and therapeutic targets

BACKGROUND

Nonalcoholic steatohepatitis (NASH) has been the second most common cause of liver transplantation in the United States. To date, NASH pathogenesis has not been fully elucidated but is multifactorial, involving insulin resistance, obesity, metabolic disorders, diet, dysbiosis, and gene polymorphism. An effective and approved therapy for NASH has also not been established. Bile acid is long known to have physiological detergent function in emulsifying and absorbing lipids and lipid-soluble molecules within the intestinal lumen. With more and more in-depth understandings of bile acid, it has been deemed to be a pivotal signaling molecule, which is capable of regulating lipid and glucose metabolism, liver inflammation, and fibrosis. In recent years, a plethora of studies have delineated that disrupted bile acid homeostasis is intimately correlated with NASH disease severity.

AIMS

The review aims to clarify the role of bile acid in hepatic lipid and glucose metabolism, liver inflammation, as well as liver fibrosis, and discusses the safety and efficacy of some pharmacological agents targeting bile acid and its associated pathways for NASH.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Bile acid has a salutary effect on hepatic metabolic disorders, which can ameliorate liver fat accumulation and insulin resistance mainly through activating Takeda G-protein coupled receptor 5 and farnesoid X receptor. Moreover, bile acid also exerts anti-inflammation and anti-fibrosis properties. Furthermore, bile acid has great potential in nonalcoholic liver disease stratification and treatment of NASH.

Nuclear receptor interdomain communication is mediated by the hinge with ligand specificity

Nuclear receptors are ligand-induced transcription factors that bind directly to target genes and regulate their expression. Ligand binding initiates conformational changes that propagate to other domains, allosterically regulating their activity. The nature of this interdomain communication in nuclear receptors is poorly understood, largely owing to the difficulty of experimentally characterizing full-length structures. We have applied computational modeling approaches to describe and study the structure of the full length farnesoid X receptor (FXR), approximated by the DNA binding domain (DBD) and ligand binding domain (LBD) connected by the flexible hinge region. Using extended molecular dynamics simulations (> 10 microseconds) and enhanced sampling simulations, we provide evidence that ligands selectively induce domain rearrangement, leading to interdomain contact. We use protein-protein interaction assays to provide experimental evidence of these interactions, identifying a critical role of the hinge in mediating interdomain contact. Our results illuminate previously unknown aspects of interdomain communication in FXR and provide a framework to enable characterization of other full length nuclear receptors.

Mechanism of antagonist ligand binding to REV-ERBα

REV-ERBα, a therapeutically promising nuclear hormone receptor, plays a crucial role in regulating various physiological processes such as the circadian clock, inflammation, and metabolism. However, the availability of chemical probes to investigate the pharmacology of this receptor is limited, with SR8278 being the only identified synthetic antagonist. Moreover, no X-ray crystal structures are currently available that demonstrate the binding of REV-ERBα to antagonist ligands. This lack of structural information impedes the development of targeted therapeutics. To address this issue, we employed Gaussian accelerated molecular dynamics (GaMD) simulations to investigate the binding pathway of SR8278 to REV-ERBα. For comparison, we also used GaMD to observe the ligand binding process of STL1267, for which an X-ray structure is available. GaMD simulations successfully captured the binding of both ligands to the receptor's orthosteric site and predicted the ligand binding pathway and important amino acid residues involved in the antagonist SR8278 binding. This study highlights the effectiveness of GaMD in investigating protein-ligand interactions, particularly in the context of drug recognition for nuclear hormone receptors.

Unraveling the evolutionary origin of the complex Nuclear Receptor Element (cNRE), a cis-regulatory module required for preferential expression in the atrial chamber

Cardiac function requires appropriate proteins in each chamber. Atria requires slow myosin to act as reservoirs, while ventricles demand fast myosin for swift pumping. Myosins are thus under chamber-biased cis-regulation, with myosin gene expression imbalances leading to congenital heart dysfunction. To identify regulatory inputs leading to cardiac chamber-biased expression, we computationally and molecularly dissected the quail Slow Myosin Heavy Chain III (SMyHC III) promoter that drives preferential expression to the atria. We show that SMyHC III gene states are orchestrated by a complex Nuclear Receptor Element (cNRE) of 32 base pairs. Using transgenesis in zebrafish and mice, we demonstrate that preferential atrial expression is achieved by a combinatorial regulatory input composed of atrial activation motifs and ventricular repression motifs. Using comparative genomics, we show that the cNRE might have emerged from an endogenous viral element through infection of an ancestral host germline, revealing an evolutionary pathway to cardiac chamber-specific expression.

Design, Synthesis, and Evaluation of B-(Trifluoromethyl)phenyl Phosphine-Borane Derivatives as Novel Progesterone Receptor Antagonists

We previously revealed that phosphine-boranes can function as molecular frameworks for biofunctional molecules. In the present study, we exploited the diversity of available phosphines to design and synthesize a series of B-(trifluoromethyl)phenyl phosphine-borane derivatives as novel progesterone receptor (PR) antagonists. We revealed that the synthesized phosphine-borane derivatives exhibited LogP values in a predictable manner and that the P-H group in the phosphine-borane was almost nonpolar. Among the synthesized phosphine-boranes, which exhibited PR antagonistic activity, B-(4-trifluoromethyl)phenyl tricyclopropylphosphine-borane was the most potent with an IC50 value of 0.54 μM. A docking simulation indicated that the tricyclopropylphosphine moiety plays an important role in ligand-receptor interactions. These results support the idea that phosphine-boranes are versatile structural options in drug discovery, and the developed compounds are promising lead compounds for further structural development of next-generation PR antagonists.

Future therapeutic perspectives in nonalcoholic fatty liver disease: a focus on nuclear receptors, a promising therapeutic target

Non-alcoholic fatty liver disease (NAFLD) is a major public health problem worldwide, with an increasing incidence, secondary to the increasing incidence of obesity and diabetes, from a very young age. It is associated with metabolic and cardiovascular disorders, as components of the metabolic syndrome (MS). NAFLD is the hepatic manifestation of MS. The pathogenesis of the disease is multifactorial and complex, involving genetic, metabolic, but also environmental factors. Currently, nuclear receptors (NRs) represent a promising therapeutic target in the treatment of non-alcoholic steatohepatitis (NASH). Of these, the most studied receptor was the liver X receptor (LXR), which would have great potential in the treatment of metabolic diseases, namely hypercholesterolemia, atherosclerosis, and NAFLD. However, the therapeutic use of NRs is restricted in medical practice for two reasons: limited knowledge of the structure of the receptor and its inability to modulate certain actions in the target organs and genes. One problem is the understanding of the function and structure of the N-terminal domain which has a major transcriptional activation function (AF1).

Rational evolution for altering the ligand preference of estrogen receptor alpha

Estrogen receptor α is commonly used in synthetic biology to control the activity of genome editing tools. The activating ligands, estrogens, however, interfere with various cellular processes, thereby limiting the applicability of this receptor. Altering its ligand preference to chemicals of choice solves this hurdle but requires adaptation of unspecified ligand-interacting residues. Here, we provide a solution by combining rational protein design with multi-site-directed mutagenesis and directed evolution of stably integrated variants in Saccharomyces cerevisiae. This method yielded an estrogen receptor variant, named TERRA, that lost its estrogen responsiveness and became activated by tamoxifen, an anti-estrogenic drug used for breast cancer treatment. This tamoxifen preference of TERRA was maintained in mammalian cells and mice, even when fused to Cre recombinase, expanding the mammalian synthetic biology toolbox. Not only is our platform transferable to engineer ligand preference of any steroid receptor, it can also profile drug-resistance landscapes for steroid receptor-targeted therapies.

Hyperbaric Oxygen Therapy Attenuated the Motor Coordination and Cognitive Impairment of Polyglutamine Spinocerebellar Ataxia SCA17 Mice

Spinocerebellar ataxias (SCAs) are a large and diverse group of autosomal-dominant neurodegenerative diseases. No drugs have been approved for these relentlessly progressive and fatal SCAs. Our previous studies indicate that oxidative stress, neuroinflammation, and neuronal apoptosis are elevated in the SCA17 mice, which are the main therapeutic targets of hyperbaric oxygen treatment (HBOT). HBOT is considered to be an alternative and less invasive therapy for SCAs. In this study, we evaluated the HBOT (2.2 ATA for 14 days) effect and the persistence for the management of SCA17 mice and their wild-type littermates. We found HBOT attenuated the motor coordination and cognitive impairment of SCA17 mice and which persisted for about 1 month after the treatment. The results of several biochemistry and liver/kidney hematoxylin and eosin staining show the HBOT condition has no obvious toxicity in the mice. Immunostaining analyses show that the neuroprotective effect of HBOT could be through the promotion of BDNF production and the amelioration of neuroinflammation. Surprisingly, HBOT executes different effects on the male and female SCA17 mice, including the reduction of neuroinflammation and activation of CaMKII and ERK. This study suggests HBOT is a potential alternative therapeutic treatment for SCA17. Accumulated findings have revealed the similarity in disease pathomechanisms and possible therapeutic strategies in polyQ diseases; therefore, HBOT could be an optional treatment as well as the other polyQ diseases.

Identification and analysis of the molecular targets of statins in colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world. According to several types of research, statins may impact the development and treatment of CRC. This work aimed to use bioinformatics to discover the relationship between statin targets and differentially expressed genes (DEGs) in CRC patients and determine the possible molecular effect of statins on CRC suppression. We used CRC datasets from the GEO database to select CRC-related DEGs. DGIdb and STITCH databases were used to identify gene targets of subtypes of statin. Further, we identified the statin target of CRC DEGs hub genes by using a Venn diagram of CRC DEGs and statin targets. Funrich and enrichr databases were carried out for the KEGG pathway and gene ontology (GO) enrichment analysis, respectively. GSE74604 and GSE10950 were used to identify CRC DEGs. After analyzing datasets,1370 genes were identified as CRC DEGs, and 345 targets were found for statins. We found that 35 genes are CRC DEGs statin targets. We found that statin targets in CRC were enriched in the receptor and metallopeptidase activity for molecular function, cytoplasm and plasma membrane for cellular component, signal transduction, and cell communication for biological process genes were substantially enriched based on FunRich enrichment. Analysis of the KEGG pathways revealed that the overexpressed DEGs were enriched in the IL-17, PPAR, and Toll-like receptor signaling pathways. Finally, CCNB1, DNMT1, AURKB, RAC1, PPARGC1A, CDKN1A, CAV1, IL1B, and HSPD1 were identified as hub CRC DEGs statin targets. The genetic and molecular aspects of our findings reveal that statins might have a therapeutic effect on CRC.

Establishment of Murine Pregnancy Requires the Promyelocytic Leukemia Zinc Finger Transcription Factor

Using an established human primary cell culture model, we previously demonstrated that the promyelocytic leukemia zinc finger (PLZF) transcription factor is a direct target of the progesterone receptor (PGR) and is essential for progestin-dependent decidualization of human endometrial stromal cells (HESCs). These in vitro findings were supported by immunohistochemical analysis of human endometrial tissue biopsies, which showed that the strongest immunoreactivity for endometrial PLZF is detected during the progesterone (P4)-dominant secretory phase of the menstrual cycle. While these human studies provided critical clinical support for the important role of PLZF in P4-dependent HESC decidualization, functional validation in vivo was not possible due to the absence of suitable animal models. To address this deficiency, we recently generated a conditional knockout mouse model in which PLZF is ablated in PGR-positive cells of the mouse (Plzf d/d). The Plzf d/d female was phenotypically analyzed using immunoblotting, real-time PCR, and immunohistochemistry. Reproductive function was tested using the timed natural pregnancy model as well as the artificial decidual response assay. Even though ovarian activity is not affected, female Plzf d/d mice exhibit an infertility phenotype due to an inability of the embryo to implant into the Plzf d/d endometrium. Initial cellular and molecular phenotyping investigations reveal that the Plzf d/d endometrium is unable to develop a transient receptive state, which is reflected at the molecular level by a blunted response to P4 exposure with a concomitant unopposed response to 17-β estradiol. In addition to a defect in P4-dependent receptivity, the Plzf d/d endometrium fails to undergo decidualization in response to an artificial decidual stimulus, providing the in vivo validation for our earlier HESC culture findings. Collectively, our new Plzf d/d mouse model underscores the physiological importance of the PLZF transcription factor not only in endometrial stromal cell decidualization but also uterine receptivity, two uterine cellular processes that are indispensable for the establishment of pregnancy.

Vitamin D in Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) is characterized by the proliferation of malignant T cells in inflamed skin lesions. Mycosis fungoides (MF)-the most common variant of CTCL-often presents with skin lesions around the abdomen and buttocks ("bathing suit" distribution), i.e., in skin areas devoid of sun-induced vitamin D. For decades, sunlight and vitamin D have been connected to CTCL. Thus, vitamin D induces apoptosis and inhibits the expression of cytokines in malignant T cells. Furthermore, CTCL patients often display vitamin D deficiency, whereas phototherapy induces vitamin D and has beneficial effects in CTCL, suggesting that light and vitamin D have beneficial/protective effects in CTCL. Inversely, vitamin D promotes T helper 2 (Th2) cell specific cytokine production, regulatory T cells, tolerogenic dendritic cells, as well as the expression of immune checkpoint molecules, all of which may have disease-promoting effects by stimulating malignant T-cell proliferation and inhibiting anticancer immunity. Studies on vitamin D treatment in CTCL patients showed conflicting results. Some studies found positive effects, others negative effects, while the largest study showed no apparent clinical effect. Taken together, vitamin D may have both pro- and anticancer effects in CTCL. The balance between the opposing effects of vitamin D in CTCL is likely influenced by treatment and may change during the disease course. Therefore, it remains to be discovered whether and how the effect of vitamin D can be tilted toward an anticancer response in CTCL.

Clinical Relevance of Differential RARα and PPARβ/δ Expression in Myelodysplastic Syndromes

BACKGROUND/AIM

Myelodysplastic syndromes (MDS) are clinically heterogeneous hematological malignancies with an increased risk of transformation to acute myeloid leukemia, emphasizing the importance of identifying new diagnostic and prognostic markers. This study sought to investigate the predictive ability of all-trans retinoic acid (ATRA)-dependent nuclear transcription factors RARα and PPARβ/δ gene expression in MDS patients.

MATERIALS AND METHODS

Peripheral blood specimens were collected from 49 MDS patients and 15 healthy volunteers. The specimens were further separated in Ficoll density gradient to obtain the mononuclear cells fractions. Gene expression analysis was carried out using quantitative real-time polymerase chain reaction (qRT-PCR) technique.

RESULTS

In the mononuclear cell fractions of MDS patients, RARα expression was increased (p<0.05) and PPARβ/δ expression was decreased (p<0.01) compared to healthy volunteers. When RARα and PPARβ/δ expression was compared in groups of MDS patients with different risks of disease progression, no statistically significant difference was found for RARα expression, while PPARβ/δ expression was significantly lower in the high-risk group of patients compared to the low-risk group (p<0.05). The expression of RARα was significantly associated with overall survival (p<0.05). ROC analysis showed that the expression of PPARβ/δ, rather than RARα expression, could have potential diagnostic value for MDS patients (AUC=0.75, p=0.003 and AUC=0.65, p=0.081, respectively).

CONCLUSION

RARα and PPARβ/δ genes are putative biomarkers that may be associated with the diagnosis and prognosis of MDS.

Androgen receptors rapidly modulate non-breeding aggression in male and female weakly electric fish (Gymnotus omarorum)

The South American weakly electric fish, Gymnotus omarorum, displays territorial aggression year-round in both sexes. To examine the role of rapid androgen modulation in non-breeding aggression, we administered acetate cyproterone (CPA), a potent inhibitor of androgen receptors, to both male and females, just before staged agonistic interactions. Wild-caught fish were injected with CPA and, 30 min later, paired in intrasexual dyads. We then recorded the agonistic behavior which encompasses both locomotor displays and emission of social electric signals. We found that CPA had no discernible impact on the levels of aggression or the motivation to engage in aggressive behavior for either sex. However, CPA specifically decreased the expression of social electric signals in both males and female dyads. The effect was status-dependent as it only affected subordinate electrocommunication behavior, the emission of brief interruptions in their electric signaling ("offs"). This study is the first demonstration of a direct and rapid androgen effect mediated via androgen receptors on non-breeding aggression. Elucidating the mechanisms involved in non-breeding aggression in this teleost model allows us to better understand potentially conserved or convergent neuroendocrine mechanisms underlying aggression in vertebrates.

Dynamic interplay of nuclear receptors in tumor cell plasticity and drug resistance: Shifting gears in malignant transformations and applications in cancer therapeutics

Recent advances have brought forth the complex interplay between tumor cell plasticity and its consequential impact on drug resistance and tumor recurrence, both of which are critical determinants of neoplastic progression and therapeutic efficacy. Various forms of tumor cell plasticity, instrumental in facilitating neoplastic cells to develop drug resistance, include epithelial-mesenchymal transition (EMT) alternatively termed epithelial-mesenchymal plasticity, the acquisition of cancer stem cell (CSC) attributes, and transdifferentiation into diverse cell lineages. Nuclear receptors (NRs) are a superfamily of transcription factors (TFs) that play an essential role in regulating a multitude of cellular processes, including cell proliferation, differentiation, and apoptosis. NRs have been implicated to play a critical role in modulating gene expression associated with tumor cell plasticity and drug resistance. This review aims to provide a comprehensive overview of the current understanding of how NRs regulate these key aspects of cancer biology. We discuss the diverse mechanisms through which NRs influence tumor cell plasticity, including EMT, stemness, and metastasis. Further, we explore the intricate relationship between NRs and drug resistance, highlighting the impact of NR signaling on chemotherapy, radiotherapy and targeted therapies. We also discuss the emerging therapeutic strategies targeting NRs to overcome tumor cell plasticity and drug resistance. This review also provides valuable insights into the current clinical trials that involve agonists or antagonists of NRs modulating various aspects of tumor cell plasticity, thereby delineating the potential of NRs as therapeutic targets for improved cancer treatment outcomes.

A reverse translational study of PPAR-α agonist efficacy in human and rodent models relevant to alcohol use disorder

Alcohol Use Disorder (AUD) is a chronic relapsing disorder affecting an estimated 283 million individuals worldwide, with substantial health and economic consequences. Peroxisome proliferator-activated receptors (PPARs), particularly PPAR-α and PPAR-γ, have shown promise in preclinical studies as potential therapeutic targets for AUD. In this human laboratory study, we aimed to translate preclinical findings on the PPAR-α agonist fenofibrate to a human population with current AUD. We hypothesized that, relative to placebo, fenofibrate at the highest FDA-approved dose of 145 mg/d would attenuate responsiveness to in vivo alcohol cues in the lab and reduce drinking under natural conditions. However, the results did not show significant differences in craving and alcohol consumption between the fenofibrate and placebo groups. Reverse translational studies in rodent models confirmed the lack of fenofibrate effect at human-equivalent doses. These findings suggest that inadequate translation of drug dose from rodents to humans may account for the lack of fenofibrate effects on alcohol craving and consumption in humans with AUD. The results highlight the need for new brain-penetrant PPAR-α agonists to adequately test the therapeutic potential of PPAR-α agonists for AUD, and the importance of reverse translational approaches and selection of human-equivalent doses in drug development.

Insulin resistance and Metabolic dysfunction-associated steatotic liver disease (MASLD): Pathways of action of hypoglycemic agents

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by overweight/obesity, and the presence of type 2 diabetes mellitus is the most important criterion. We propose an independent disease perspective without exclusion criteria and with less heterogeneity and greater impact because, according to the National Health and Nutrition Survey (ENSANUT), in Mexico, 25 % of adults over 60 years of age suffer from diabetes, and 96 % of those over 50 years of age have abdominal obesity. Due to the impact of insulin resistance in the pathophysiology of MASLD, which results in damage to hepatocytes, this work aims to provide an overview of the action pathways of hypoglycemic agents such as glucagon-like-1 receptor agonist and peroxisome proliferator-activated receptor-gamma agonists, whose importance lies in the fact that they are currently undergoing phase 2 studies, as well as dipeptidyl peptidase 4 inhibitors and sodium-glucose co-transporter type 2 inhibitors, which are undergoing phase 1 study trials.

Delineating the role of nuclear receptors in colorectal cancer, a focused review

Colorectal cancer (CRC) stands as one of the most prevalent form of cancer globally, causing a significant number of deaths, surpassing 0.9 million in the year 2020. According to GLOBOCAN 2020, CRC ranks third in incidence and second in mortality in both males and females. Despite extensive studies over the years, there is still a need to establish novel therapeutic targets to enhance the patients' survival rate in CRC. Nuclear receptors (NRs) are ligand-activated transcription factors (TFs) that regulate numerous essential biological processes such as differentiation, development, physiology, reproduction, and cellular metabolism. Dysregulation and anomalous expression of different NRs has led to multiple alterations, such as impaired signaling cascades, mutations, and epigenetic changes, leading to various diseases, including cancer. It has been observed that differential expression of various NRs might lead to the initiation and progression of CRC, and are correlated with poor survival outcomes in CRC patients. Despite numerous studies on the mechanism and role of NRs in this cancer, it remains of significant scientific interest primarily due to the diverse functions that various NRs exhibit in regulating key hallmarks of this cancer. Thus, modulating the expression of NRs with their agonists and antagonists, based on their expression levels, holds an immense prospect in the diagnosis, prognosis, and therapeutical modalities of CRC. In this review, we primarily focus on the role and mechanism of NRs in the pathogenesis of CRC and emphasized the significance of targeting these NRs using a variety of agents, which may represent a novel and effective strategy for the prevention and treatment of this cancer.

Exploring the nexus of nuclear receptors in hematological malignancies

Hematological malignancies (HM) represent a subset of neoplasms affecting the blood, bone marrow, and lymphatic systems, categorized primarily into leukemia, lymphoma, and multiple myeloma. Their prognosis varies considerably, with a frequent risk of relapse despite ongoing treatments. While contemporary therapeutic strategies have extended overall patient survival, they do not offer cures for advanced stages and often lead to challenges such as acquisition of drug resistance, recurrence, and severe side effects. The need for innovative therapeutic targets is vital to elevate both survival rates and patients' quality of life. Recent research has pivoted towards nuclear receptors (NRs) due to their role in modulating tumor cell characteristics including uncontrolled proliferation, differentiation, apoptosis evasion, invasion and migration. Existing evidence emphasizes NRs' critical role in HM. The regulation of NR expression through agonists, antagonists, or selective modulators, contingent upon their levels, offers promising clinical implications in HM management. Moreover, several anticancer agents targeting NRs have been approved by the Food and Drug Administration (FDA). This review highlights the integral function of NRs in HM's pathophysiology and the potential benefits of therapeutically targeting these receptors, suggesting a prospective avenue for more efficient therapeutic interventions against HM.