Receptor Transcripts Research Articles

Functional Analysis of Genes Encoding Juvenile Hormone Receptor Met and Transcription Factor Kr-h1 in the Reproductive Capacity of Coccinella septempunctata Males

This study focuses on the regulatory effects of genes encoding the juvenile hormone (JH) receptor methoprene-tolerant (Met) and transcription factor krüppel homolog 1 (Kr-h1) on the reproductive capacity of Coccinella septempunctata male adults. Met and Kr-h1 expression levels were analyzed in males fed on artificial diets with and without JH by quantitative real-time PCR, and the effects of Met and Kr-h1 on male reproduction were analyzed by RNA interference technology. Met transcription levels in 5- and 10-day-old males fed with a JH-supplemented diet were lower than those without JH. Kr-h1 expression in 5-day-old adult males was lower in diets lacking JH but was higher in 10-day-old males fed on a diet lacking JH. There were no significant differences in the testes sizes of male ladybugs injected with Met-dsRNA when compared to GFP-dsRNA; however, the testis volume of ladybugs injected with Kr-h1-dsRNA was smaller than those injected with GFP-dsRNA. After males were injected with Met-dsRNA and Kr-h1-dsRNA, the mean egg production by females decreased by 12.75% and 23.10%, respectively, at 20 d postinjection. Our results show that Met and Kr-h1 have important roles in regulating reproduction by directly affecting testes development in males and egg production in females.

Single-nucleus transcriptomics reveals time-dependent and cell-type-specific effects of psilocybin on gene expression.

There is growing interest to investigate classic psychedelics as potential therapeutics for mental illnesses. Previous studies have demonstrated that one dose of psilocybin leads to persisting neural and behavioral changes. The durability of psilocybin's effects suggests that there are likely alterations of gene expression at the transcriptional level. In this study, we performed single-nucleus RNA sequencing of the dorsal medial frontal cortex of male and female mice. Samples were collected at 1, 2, 4, 24, or 72 hours after psilocybin or ketamine administration and from control animals. At baseline, major excitatory and GABAergic cell types selectively express particular serotonin receptor transcripts. The psilocybin-evoked differentially expressed genes in excitatory neurons were involved in synaptic plasticity, which were distinct from genes enriched in GABAergic neurons that contribute to mitochondrial function and cellular metabolism. The effect of psilocybin on gene expression was time-dependent, including an early phase at 1-2 hours followed by a late phase at 72 hours of transcriptional response after administration. Ketamine administration produced transcriptional changes that show a high degree of correlation to those induced by psilocybin. Collectively, the results reveal that psilocybin produces time-dependent and cell-type specific changes in gene expression in the medial frontal cortex, which may underpin the drug's long-term effects on neural circuits and behavior.

The glycoprotein hormone receptor (LGR1) influences Malpighian tubule secretion rate in Rhodnius prolixus.

In the hemipteran Rhodnius prolixus, successful post-prandial diuresis is accomplished through the synergistic actions of the peptidergic diuretic hormone RhoprCRF/DH and the biogenic amine 5-hydroxytryptamine (5-HT), and by an antidiuretic hormone RhoprCAPA-2 that terminates diuresis by inhibiting this synergy. Lateral neurosecretory cells (NSCs) in the mesothoracic ganglionic mass release RhoprCRF/DH, while midline NSCs release RhoprCAPA-2 during blood feeding. These NSCs co-express GPA2/GPB5, a conserved glycoprotein hormone involved in various physiological processes across bilaterians. This study investigated the influence of GPA2/GPB5 signaling on Malpighian tubule (MT) fluid secretion in R. prolixus. GPB5-like immunoreactivity in lateral and midline NSCs decreased following a blood meal, suggesting release and a role in diuresis. Downregulating the GPA2/GPB5 receptor LGR1 via RNA interference resulted in an increased basal fluid secretion rate in MTs, which was inhibited by the antidiuretic hormone RhoprCAPA-2. dsLGR1 treatment reduced the effects of RhoprCRF/DH and 5-HT on MT secretion and eliminated their synergism. RT-qPCR revealed that the expression of the diuretic and antidiuretic hormone receptors decreased in MTs of dsLGR1-injected insects, indicating that GPA2/GPB5 influences the expression of these other receptors. Downregulating LGR1 resulted in a smaller blood meal size and disrupted the normal time course of diuresis. As LGR1 is the most abundantly expressed G protein-coupled receptor gene in R. prolixus MTs, our results suggest that GPA2/GPB5 signaling has a critical role in regulating the timing and success of water retention in the unfed state, and in the complex processes associated with feeding and diuresis in R. prolixus.

Transcriptomic analysis of luteal tissue supports the earlier onset of luteolysis in heifers with diminished ovarian reserve.

Context Antral follicle count (AFC) is reflective of ovarian reserve and linked to reproductive performance in mammalian females. We previously demonstrated earlier upregulation of endometrial oxytocin receptor transcription in heifers with low AFC, indicating an earlier onset of luteolysis. Aims We aimed to support the earlier onset of luteolysis in non-pregnant heifers with a low number of antral ovarian follicles (Open Low AFC) and hypothesized a reduced abundance of luteinizing hormone/choriogonadotropin receptor (LH/CG-R ) and increased abundance of thrombospondin-1 (THBS1 ) in luteal tissue of those heifers. We further investigated if classical interferon stimulated genes (ISGs) are already upregulated in response to conceptus-derived interferon tau. Methods For 4years, 10 heifers with the highest (High AFC) and 10 heifers with the lowest AFC (Low AFC) of the population (n =120/year) were selected, synchronized and inseminated. On day 15 or 16 after insemination, reproductive tracts were collected, and pregnancy status was determined. Corpora lutea were isolated, weighed and underwent transcriptomic analysis. Key results Transcript abundance of LH/CG-R was lower in Open Low AFC heifers compared to all other subgroups. Transcript abundance of THBS1 was upregulated in Open vs Pregnant heifers and showed greater abundance in Low vs High AFC heifers. Luteal weights and abundance of ISGs did not differ between heifers of differing AFC groups or pregnancy status. Conclusions The patterns of luteal LH /CG-R and THBS1 abundance support the concept of earlier onset of luteolysis in Open heifers with diminished AFC. Implications This may result in a shorter window for maternal recognition of pregnancy and contribute to inferior reproductive performance.

Prostaglandin pathways in equine myometrium regulations: endometrosis progression.

Prostaglandins (PG) are important regulators of the myometrial contractility in mammals. Endometrosis, a condition characterized by morphological changes in the equine endometrium, also affects endometrial secretory function. However, it remains unclear whether and how endometrosis affects myometrial function. This study investigated: (i) mRNA transcription of genes encoding specific enzymes responsible for PG synthesis, such as prostaglandin-endoperoxide synthase (PTGS2), PGE2 synthase (PTGES), PGF2α synthase (PTGFS) and PG receptors: PGE2 receptors (PTGER1- 4), and PGF2α receptor (PTGFS) in equine myometrium and, (ii) the effects of PGE2 and PGF2α on myometrial contractile activity, during endometrosis in mares. The myometria used in experiments 1 and 2 were collected from mares in the mid-luteal (n = 23) and follicular (n = 20) phases of the estrous cycle, according to the histological classification of the endometrium (Kenney and Doig categories I, IIA, IIB, and III). In experiment 1, changes in mRNA transcription of PG synthase or PG receptors in the myometrium during the course of endometrosis were determined using qPCR. During the mid-luteal phase, myometrial mRNA transcription of PTGES increased in mares with endometrial category IIB compared to category I. However, myometrial mRNA transcription of PTGER1 decreased during the progression of endometrosis compared to category I. During the follicular phase, mRNA transcription of PTGER1 and PTGER2 increased in mares with endometrial categories III or IIA, respectively. In addition, mRNA transcription of PTGFS increased in mares with endometrium category IIA compared to category I. In experiment 2, the force of myometrial contractions was measured using an isometric concentration transducer. In the follicular phase, PGE2 decreased the force of contractions in mares with endometrial categories IIA, IIB, and III compared to the respective control groups. Prostaglandin F2α increased the force of myometrial contractions in mares with category IIA endometrium, whereas it decreased in category IIB compared to the respective control groups. We concluded that in the progression of endometrosis there are changes in the myometrial transcription of mRNA encoding PG synthases and receptors, particularly PTGER1 and PTGER2. Mares with endometrosis had abnormal myometrial contractile responses to PG. These findings suggest that myometrial function may be compromised during the progression of endometrosis.

Arsenic Trioxide (ATOIII) Induces NAD(P)H Quinone Oxidoreductase 1 (NQO1) Expression in Hepatic and Extrahepatic Tissues of C57BL/6 Mice.

Arsenic trioxide (ATOIII) has emerged as a potent therapeutic agent for acute promyelocytic leukemia (APL), yet its clinical application is often limited by significant adverse effects. This study investigates the molecular mechanisms underlying ATOIII's impact on cellular detoxification pathways, focusing on the regulation of NAD(P)H/quinone oxidoreductase (NQO1), a crucial enzyme in maintaining cellular homeostasis and cancer prevention. We explored ATOIII's effects on NQO1 expression in C57BL/6 mice and Hepa-1c1c7 cells, both independently and in combination with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a known NQO1 inducer. Our findings revealed that ATOIII significantly increased NQO1 expression in hepatic and extrahepatic tissues, as well as in Hepa-1c1c7 cells, at mRNA, protein, and activity levels. This upregulation occurred both in the presence and absence of TCDD. Mechanistically, we demonstrated that ATOIII promotes the nuclear translocation of both nuclear factor erythroid 2-related factor-2 (NRF2) and aryl hydrocarbon receptor (AHR) transcription factors. Furthermore, ATOIII exposure increased antioxidant response element (ARE)-driven reporter gene activity, indicating a transcriptional mechanism of NQO1 induction. Notably, gene silencing experiments confirmed the critical roles of both NRF2 and AHR in mediating ATOIII-induced NQO1 expression. In conclusion, ATOIII exposure is found to upregulate the NQO1 enzyme through a transcriptional mechanism via AHR- and NRF2- dependent mechanisms, offering valuable insights into its therapeutic mechanisms.

Evaluating ovarian follicles and their steroid hormone gene expression patterns in a high egg-producing research turkey line

Low egg-producing turkeys reduce the profitability of a flock by limiting the number of poults that can be hatched. Understanding the biological mechanics behind egg-production rates will greatly benefit the industry. Two lines with vastly different egg production rates are the Ohio State University E line, and its unselected counterpart, the random-bred control one (RBC1). Differences between E Line and RBC1 hens (n = 4 per line) were investigated by measuring egg production traits, ovarian and follicle anatomical characteristics, and gene expression for reproductively important genes within different follicle types. Data were analyzed by an ANOVA mixed model procedure in SAS. The E line hens produced 20% more eggs than the RBC1 hens, even though they had similar numbers of preovulatory follicles in their ovaries. This was accomplished by increasing clutch length and keeping the pause length the same. On the gene expression side small white follicles (SWF) within E line hens had less LHCGR expression which coincided with downregulation of CYP11A1 and CYP17A1. Along with an upregulation of PRLR in small yellow follicles (SYF) which also coincided with downregulation of CYP17A1. In both cases changes in pituitary hormone receptor transcription levels appeared to affect the steroid hormone synthesis pathway. In SWF from E line hens ESR2 was downregulated, however in the large white follicles and selected follicles ESR1 was the estradiol receptor which was downregulated. The similarity in preovulatory numbers suggests that E line hens aren't selecting more follicles to grow, but instead, follicles are growing faster. Based on the gene expression patterns, the reduction of steroid hormone synthesis might hint at the follicles putting more energy into growth and differentiation. At the same time, the decrease in estradiol receptor might limit the negative effects of estradiol on granulosa cells and allow for more rapid growth, suggesting a possible mechanism for the higher egg production trait of the E line.

Unanticipated mechanisms of covalent inhibitor and synthetic ligand cobinding to PPARγ

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor transcription factor that regulates gene expression programs in response to ligand binding. Endogenous and synthetic ligands, including covalent antagonist inhibitors GW9662 and T0070907, are thought to compete for the orthosteric pocket in the ligand-binding domain (LBD). However, we previously showed that synthetic PPARγ ligands can cooperatively cobind with and reposition a bound endogenous orthosteric ligand to an alternate site, synergistically regulating PPARγ structure and function (Shang et al., 2018). Here, we reveal the structural mechanism of cobinding between a synthetic covalent antagonist inhibitor with other synthetic ligands. Biochemical and NMR data show that covalent inhibitors weaken—but do not prevent—the binding of other ligands via an allosteric mechanism, rather than direct ligand clashing, by shifting the LBD ensemble toward a transcriptionally repressive conformation, which structurally clashes with orthosteric ligand binding. Crystal structures reveal different cobinding mechanisms including alternate site binding to unexpectedly adopting an orthosteric binding mode by altering the covalent inhibitor binding pose. Our findings highlight the significant flexibility of the PPARγ orthosteric pocket, its ability to accommodate multiple ligands, and demonstrate that GW9662 and T0070907 should not be used as chemical tools to inhibit ligand binding to PPARγ.

Single cell RNA-sequencing of feline peripheral immune cells with V(D)J repertoire and cross species analysis of T lymphocytes.

The domestic cat (Felis catus) is a valued companion animal and a model for virally induced cancers and immunodeficiencies. However, species-specific limitations such as a scarcity of immune cell markers constrain our ability to resolve immune cell subsets at sufficient detail. The goal of this study was to characterize circulating feline T cells and other leukocytes based on their transcriptomic landscape and T-cell receptor repertoire using single cell RNA-sequencing. Peripheral blood from 4 healthy cats was enriched for T cells by flow cytometry cell sorting using a mouse anti-feline CD5 monoclonal antibody. Libraries for whole transcriptome, αβ T cell receptor transcripts and γδ T cell receptor transcripts were constructed using the 10x Genomics Chromium Next GEM Single Cell 5' reagent kit and the Chromium Single Cell V(D)J Enrichment Kit with custom reverse primers for the feline orthologs. Unsupervised clustering of whole transcriptome data revealed 7 major cell populations - T cells, neutrophils, monocytic cells, B cells, plasmacytoid dendritic cells, mast cells and platelets. Sub cluster analysis of T cells resolved naive (CD4+ and CD8+), CD4+ effector T cells, CD8+ cytotoxic T cells and γδ T cells. Cross species analysis revealed a high conservation of T cell subsets along an effector gradient with equitable representation of veterinary species (horse, dog, pig) and humans with the cat. Our V(D)J repertoire analysis identified a subset of CD8+ cytotoxic T cells with skewed TRA and TRB gene usage, conserved TRA and TRB junctional motifs, restricted TRA/TRB pairing and reduced diversity in TRG junctional length. We also identified a public γδ T cell subset with invariant TRD and TRG chains and a CD4+ TEM-like phenotype. Among monocytic cells, we resolved three clusters of classical monocytes with polarization into pro- and anti-inflammatory phenotypes in addition to a cluster of conventional dendritic cells. Lastly, our neutrophil sub clustering revealed a larger mature neutrophil cluster and a smaller exhausted/activated cluster. Our study is the first to characterize subsets of circulating T cells utilizing an integrative approach of single cell RNA-sequencing, V(D)J repertoire analysis and cross species analysis. In addition, we characterize the transcriptome of several myeloid cell subsets and demonstrate immune cell relatedness across different species.

GnRH-Gonadotropes Interactions Revealed by Pituitary Single-cell Transcriptomics in Zebrafish.

GnRH governs reproduction by regulating pituitary gonadotropins. Unlike most vertebrates, gnrh-/- zebrafish are fertile. To elucidate the role of the hypophysiotropic-Gnrh3 and other mechanisms regulating pituitary gonadotropes, we profiled the gene expression of all individual pituitary cells of wild-type and gnrh3-/- adult female zebrafish. The single-cell RNA sequencing showed that LH and FSH gonadotropes express the 2 gonadotropin beta subunits with a ratio of 140:1 (lhb:fshb) and 4:1 (fshb:lhb), respectively. Lh gonadotropes predominantly express genes encoding receptors for GnRH (gnrhr2), thyroid hormone, estrogen, and steroidogenic factor 1. No GnRH receptor transcript was enriched in FSH gonadotropes. Instead, cholecystokinin receptor-b and galanin receptor-1b transcripts were enriched in these cells. The loss of the Gnrh3 gene in gnrh3-/- zebrafish resulted in downregulation of fshb in LH gonadotropes and upregulation of pituitary hormones like TSH, GH, prolactin, and proopiomelanocortin-a. Likewise, targeted chemogenetic ablation of Gnrh3 neurons led to a decrease in the number of fshb+, lhb + and fshb+/lhb + cells. Our studies suggest that Gnrh3 directly acts on LH gonadotropes through Gnrhr2, but the outcome of this interaction is still unknown. Gnrh3 also regulates fshb expression in both gonadotropes, most likely via a non-GnRH receptor route. Altogether, while LH secretion and synthesis are likely regulated in a GnRH-independent manner, Gnrh3 seems to play a role in the cellular organization of the pituitary. Moreover, the coexpression of lhb and fshb in both gonadotropes provides a possible explanation as to why gnrh3-/- zebrafish are fertile.

From bench to bedside and back to bench: investigating the role of platelet heterogeneity in coronary artery disease

Abstract Background/Introduction Platelets exhibit considerable heterogeneity in RNA content, size, and thrombogenicity. Our preliminary investigation of the transcriptome of the RNA-rich reticulated platelets(RPs) in healthy donors revealed an enrichment of prothrombotic transcripts compared to mature platelets(MPs). Recently, we validated the prognostic role of elevated RPs at clinical level in a modern cohort of ACS patients treated with potent P2Y12 inhibitors. However, the pathophysiology of RP hyperreactivity remains unclear, particularly its correlation with adverse events and cardiovascular death. Purpose To study the biology of RPs in patients with chronic coronary syndrome(CCS) and to elucidate their role in disease progression. Methods RPs were isolated from peripheral blood of CCS patients(N=20) and compared with MPs. Cell viability and reactivity of RPs were quantified by FACS. Deep transcriptomic profiling was performed using post-sorting bulk RNA sequencing of RPs and MPs and analyzed with ad-hoc bioinformatic pipelines. Proteomic profiling using mass cytometry(CyTOF) was used to validate the transcriptomic findings with single cell resolution. Results FACS analysis confirmed RPs hyperreactivity showing increased P-Selectin expression upon activation with TRAP, ADP and Collagen(Fig. 1A). Total RNA-sequencing detected 2213 differentially regulated genes with an enrichment in RPs of key functional transcript such as, the von Willebrand Factor VWF(p=3.06*10-33), the thromboxane receptor TBXA2R(p=2.07*10-29) and the collagen receptor GP6(p=1.29*10-38, Fig. 1B-C). Gene ontology and gene set enrichment analyses detected an upregulation of relevant categories as "Regulation of platelet activation" and "Platelet aggregation"(Fig. 1D-F). In addition, we detected a novel alternative splicing event on the collagen receptor transcript GP6 upregulated in RPs(Fig. 1G). We detected 33 differentially regulated miRNAs, including miR-409, miR-134 and miR-432, which have been already linked to prothrombotic phenotypes(Fig. 1H). Additionally, we detected an enrichment of circular RNAs in RPs compared to MPs with several circular RNA upregulated in RPs, that have not been described before(Fig. 1I-K). Mass cytometry detected a significant upregulation in RPs of relevant proteins including the collagen receptor GPVI(p=8.98*10-12, Fig.2) and the thrombin receptor PAR1(p=5.21*10-11). Validation assays in an independent cohort detected an upregulation of the PI3K/AKT pathway in RPs which is downstream of the receptor PAR1 and GP6. Conclusion This study represents the first comprehensive multiomic characterization of RPs in CCS patients, providing insights into their prothrombotic phenotype and into their correlation with cardiovascular events. These findings suggest potential avenues for tailored therapeutic interventions targeting the identified upregulated pathways in patients with elevated RPs, warranting further investigation at the clinical level.

Aging alters the effect of adiponectin receptor signaling on bone marrow-derived mesenchymal stem cells.

Adiponectin receptor signaling represents a promising therapeutic target for age-related conditions such as osteoporosis and diabetes. However, the literature presents conflicting evidence regarding the role of adiponectin signaling in bone homeostasis and fracture repair across different health states, ages, and disease conditions. These inconsistencies may arise from the complex endocrine and paracrine feedback mechanisms regulating adiponectin, as well as the variability in adiponectin isoforms and receptor expressions. In this study, we observed differential expression of adiponectin receptors in the bone marrow (BM) of aged mice, characterized by elevated levels of adiponectin receptor 2 and reduced levels of receptor 1, as corroborated by both single-cell sequencing and invivo staining. Additionally, circulating levels of adiponectin and its local expression were significantly higher in aged mice compared to younger counterparts. Treatment with adiponectin receptor agonist, AdipoRon, enhanced bone regeneration and repair in young mice by promoting osteogenesis and reducing osteoclastogenesis. Conversely, in aged mice, AdipoRon treatment led to cellular senescence, delayed bone repair, and inhibited osteogenic activity. Notably, the adiponectin receptor 1-Wnt and adiponectin receptor 2-MAPK and mTOR signaling pathways were differentially activated in AdipoRon-treated BM mesenchymal stem cells from young and aged mice. Additionally, the NF-κB, and AKT pathways were consistently downregulated in BM macrophages of both age groups following AdipoRon administration. In conclusion, aging significantly modulates the impact of adiponectin receptor signaling on BM mesenchymal stem cells. This modulation is potentially attributable to changes in receptor transcription and distribution, as well as differential activation of downstream signaling pathways.

Isoform-level expression of the constitutive androstane receptor (CAR or NR1I3) transcription factor better predicts the mRNA expression of the cytochrome P450s in human liver samples.

Many factors cause inter-person variability in the activity and expression of liver cytochrome P450 (CYP) drug-metabolizing enzymes, leading to variable drug exposure and treatment outcomes. Several liver-enriched transcription factors (TFs) are associated with CYP expression, with estrogen receptor alpha (ESR1) and constitutive androstane receptor (CAR or NR1I3) being the two top factors. ESR1 and NR1I3 undergo extensive alternative splicing that results in numerous splice isoforms, but how these splice isoforms associate with CYP expression is unknown. Here, we quantified 18 NR1I3 splice isoforms and the three most abundant ESR1 isoforms in 260 liver samples derived from African Americans (AA, n=125) and European Americans (EA, n=135). Our results showed variable splice isoform populations in the liver for both NR1I3 and ESR1. Multiple linear regression analyses revealed that, compared to gene-level NR1I3, isoform-level NR1I3 expression better predicted the mRNA expression of most CYPs and three UDP-glucuronosyltransferases (UGTs), while ESR1 isoforms improved predictive models for the UGTs and CYP2D6, but not for most CYPs. Also, different NR1I3 isoforms were associated with different CYPs, and the associations varied depending on sample ancestry. Surprisingly, non-canonical NR1I3 isoforms having retained introns (introns 2 or 6) were abundantly expressed and associated with the expression of most CYPs and UGTs, whereas the reference isoform (NR1I3-205) only associated with CYP2D6. Moreover, NR1I3 isoform diversity increased during the differentiation of induced pluripotent stem cells to hepatocytes, paralleling increasing CYP expression. These results suggest that isoform-level TF expression may help to explain variation in CYP or UGT expression between individuals. Significance Statement We quantified 18 NR1I3 splice isoforms and three ESR1 splice isoforms in 260 liver samples derived from AA and EA donors and found variable NR1I3 and ESR1 splice isoform expression in the liver. Multiple linear regression analysis showed that, compared to gene-level expression, isoform-level expression of NR1I3 and ESR1 better predicted the mRNA expression of some CYPs and UGTs, highlighting the importance of isoform-level analyses to enhance our understanding of gene transcriptional regulatory networks controlling the expression of drug-metabolizing enzymes.

RXRα/MR signaling promotes diabetic kidney disease by facilitating renal tubular epithelial cells senescence and metabolic reprogramming

Cell senescence and metabolic reprogramming are significant features of diabetic kidney disease (DKD). However, the underlying mechanisms between cell senescence and metabolic reprogramming are poorly defined. Here, we report that retinoid X receptor α (RXRα), a key nuclear receptor transcription factor, regulates cell senescence and metabolic reprogramming in DKD. Through high-throughput sequencing, bioinformatic analysis and experimental validation, we confirmed the critical role of RXRα in promoting cell senescence and metabolic dysregulation in renal tubular epithelial cells (RTECs) induced by lipid overload. In vivo, in situ injection of AAV9-shRxra into the kidney reduced proteinuria, RTECs senescence and insulin resistance in DKD mice. In vitro, knockdown of RXRα markedly improved G2/M phase arrest and suppressed the expression of senescence-associated secretory phenotypes (SASPs). Protein-protein interaction (PPI) analysis and unbiased bioinformatics were employed to identify the direct interactions between RXRα and the mineralocorticoid receptor (MR), which were subsequently validated through coimmunoprecipitation. Gene network analysis revealed the collaborative regulatory role of RXRα and MR in RTECs senescence. In an accelerated aging mouse model, treatment with a MR antagonist has been shown to inhibite the RXRα/MR signaling, improve RTECs senescence, and reduce interstitial fibrosis and lipid deposition in the kidneys. These findings indicate that inhibition of RXRα/MR signaling could alleviate cell senescence during metabolic disorders. Thus, our study revealed that RXRα/MR signaling serves as a critical regulatory factor mediating the crosstalk between cell senescence and metabolic reprogramming, shedding light on a novel mechanism for targeting cell senescence and metabolic dysregulation in DKD.

UV-induced reactive oxygen species and transcriptional control of 3-deoxyanthocyanidin biosynthesis in black sorghum pericarp.

Black pericarp sorghum has notable value due to the biosynthesis of 3-deoxyanthocyanidins (3-DOAs), a rare class of bioactive polyphenols valued as antioxidant food additives and as bioactive compounds with cytotoxicity to human cancer cells. A metabolic and transcriptomic study was conducted to ascertain the cellular events leading to the activation of 3-DOA biosynthesis in black sorghum pericarp. Prolonged exposure of pericarp during grain maturation to high-fluence ultraviolet (UV) light resulted in elevated levels of reactive oxygen species (ROS) and the activation of 3-DOA biosynthesis in pericarp tissues. In conjunction with 3-DOA biosynthesis was the transcriptional activation of specific family members of early and late flavonoid biosynthesis pathway genes as well as the downstream activation of defense-related pathways. Promoter analysis of genes highly correlated with 3-DOA biosynthesis in black pericarp were enriched in MYB and HHO5/ARR-B motifs. Light microscopy studies of black pericarp tissues suggest that 3-DOAs are predominantly localized in the epicarp and are associated with the cell wall. A working model of UV-induced 3-DOA biosynthesis in black pericarp is proposed that shares features of plant immunity associated with pathogen attack or mechanical wounding. The present model depicts ROS accumulation, the transcriptional activation of receptor kinases and transcription factors (TFs) including NAC, WRKY, bHLH, AP2, and C2H2 Zinc finger domain. This study identified key biosynthetic and regulatory genes of 3-DOA accumulation in black pericarp and provided a deeper understanding of the gene networks and cellular events controlling this tissue-and genotype-specific trait.

Therapeutic potential of liver X receptor beta in depression and anxiety

Liver X receptors (LXRs), particularly LXRβ, are emerging as crucial players in the translation of basic neuroscience to clinical psychiatry. These nuclear receptor transcription factors, initially known for their roles in cholesterol metabolism and inflammation, are now revealing promising connections between molecular mechanisms and psychiatric symptoms. This review highlights recent breakthroughs in understanding LXRβ's regulation and function in behaviors relevant to depression and anxiety, derived from studies using animal paradigms that capture specific features of these disorders. We explore how these preclinical findings are shaping our comprehension of mood-related behaviors at the molecular level and potentially paving the way for innovative therapeutic strategies. As a ligand-activated transcription factor, LXRβ represents a novel target for drug development, potentially bridging the gap between bench discoveries and bedside treatments for neuropsychiatric disorders. We discuss the challenges and opportunities in translating LXRβ research into clinical interventions, emphasizing the potential for personalized medicine approaches in psychiatry. This bench-to-bedside article underscores the importance of LXRβ research in advancing our understanding and treatment of complex mental health conditions, while acknowledging the nuanced interpretation required when extrapolating from animal studies to human disorders.

Deregulation of Melatonin Receptors and Differential Modulation of After-Hyperpolarization and Ih Currents Using Melatonin Treatment Due to Amyloid-β-Induced Neurotoxicity in the Hippocampus.

Treatment with melatonin is routinely prescribed for its potent antioxidant and cognitive-promoting effects, nevertheless, it has yet to find neuromodulatory effects in normal and disease conditions. Therefore, to investigate its neuromodulatory mechanisms, melatonin was systemically administered over 10 consecutive days to both intracortical normal saline- and amyloid-β 1-42 (Aβ) peptide-injected rats. At the behavioral level, treatment with melatonin was associated with reduced efficacy in restoring Aβ-induced deficit in passive-avoidance memory. Whole-cell patch-clamp recordings from CA1 pyramidal neurons revealed that melatonin treatment reduced spontaneous and evoked intrinsic excitability in control rats while exerting a reduction of spontaneous, but not evoked activity, in the Aβ-injected group. Interestingly, treatment with melatonin enhances after-hyperpolarization in control, but not Aβ-injected rats. In contrast, our voltage-clamp study showed that Ih current is significantly enhanced by Aβ injection, and this effect is further strengthened by treatment with melatonin in Aβ-injected rats. Finally, we discovered that the transcription of melatonin receptors 1 (MT1) and 2 (MT2) is significantly upregulated in the hippocampi of Aβ-injected rats. Collectively, our study demonstrates that systemic treatment with melatonin has differential neuromodulation on CA1 neuronal excitability, at least in part, via differential effects on after-hyperpolarization and Ih currents due to Aβ-induced neurotoxicity.

G protein coupled receptor transcripts in human immune cells and platelets.

G-protein coupled receptors (GPCRs) are encoded by nonabundant mRNAs, and it is difficult to detect them reliably with the highly parallel methods that are in general use. Because of this, we developed and validated a sensitive, specific, semi-quantitative method for detecting these transcripts. We have used the method to profile GPCR transcripts in white blood cells (WBCs)-B, CD4, CD8, NK, and dendritic cells; monocytes, and macrophage-like monocytes treated with granulocyte-macrophage colony-stimulating factor-as well as platelets. On average, the white cells studied expressed 160 receptor mRNAs (range, 123-206). Platelets made 69. Some, but far from all, of the receptors we found have been detected earlier. We believe our data should stimulate studies of receptor function and contribute to drug development.

Astragaloside IV plays a neuroprotective role by promoting PPARγ in cerebral ischemia-reperfusion rats

Cerebral ischemia-reperfusion injury (CIRI) usually occurs during the treatment phase of ischemic disease, which is closely related to high morbidity and mortality. Promoting neurogenesis and synaptic plasticity are effective neural recovery strategies for CIRI. Astragaloside IV (AS-IV) has been shown to play a neuroprotective role in some neurological diseases. In the current study, we evaluated the effect and possible mechanism of AS-IV in CIRI rats. The middle cerebral artery occlusion reperfusion (MCAO/R) model was established in rats to simulate the occurrence of human CIRI. First, we determined the cerebral injury on the 1st, 3rd, 5th and 7th day after cerebral ischemia-reperfusion (I/R) surgery by neurological deficit detection, TTC staining, TUNEL staining and Western blot analysis. Furthermore, rats were pre administered with AS-IV and then subjected to cerebral I/R surgery. Brains were collected on the 3rd day to evaluate the neuroprotective effect of AS-IV. Our results showed that on the 3rd day after I/R, the neurological impairment score and infarct volume were highest, the levels of apoptosis and expression of Caspase3 and Bax reached the peak. AS-IV treatment apparently attenuated neurological dysfunction, reduced infarct volume and pathological damage, promoted the neurogenesis, and alleviated the pathological damage caused by cerebral I/R involved in thickening and blurring of synaptic membranes, reduction of microtubules and synaptic vesicles, and loss of synaptic cleft. Our study also showed that AS-IV promoted the transcription and expression of the peroxisome proliferators-activated receptors γ (PPARγ) and brain-derived neurotrophic factor (BDNF), increased the expression of phosphorylation of tyrosine kinase receptor B (TrkB) and downstream PI3K/Akt/mTOR pathway proteins. Notably, when GW9662, an inhibitor of PPARγ was administered with AS-IV, the neuroprotective effect of AS-IV was reduced. These findings suggested that AS-IV has neuroprotective function in CIRI rats, and its molecular mechanism may depend on the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (PKB)/Akt signalling pathway activated by PPARγ. AS-IV could be an effective therapeutic drug candidate for CIRI treatment.

Unanticipated mechanisms of covalent inhibitor and synthetic ligand cobinding to PPARγ.

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor transcription factor that regulates gene expression programs in response to ligand binding. Endogenous lipids and synthetic ligands, including covalent antagonist inhibitors such as GW9662 and T0070907, are thought to compete for the orthosteric pocket in the ligand-binding domain (LBD). However, we previously showed that synthetic PPARγ ligands can cooperatively cobind with and reposition a bound endogenous orthosteric ligand to an alternate site, synergistically regulating PPARγ structure and function (Shang et al., 2018). Here, we reveal the structural mechanism of cobinding between a synthetic covalent antagonist inhibitor with other synthetic ligands. Biochemical and NMR data show that covalent antagonist inhibitors weaken-but do not prevent-the binding of other synthetic ligands via an allosteric mechanism rather than direct ligand clashing. The covalent ligands shift the LBD ensemble toward a transcriptionally repressive conformation, which structurally clashes with and reduces the orthosteric binding affinity of non-covalent synthetic ligands. Crystal structures reveal different non-covalent synthetic ligand-specific cobinding mechanisms ranging from alternate site binding to unexpectedly adopting an orthosteric binding mode by altering the covalent ligand binding pose. Our findings not only highlight the significant flexibility of the PPARγ orthosteric pocket and its ability to accommodate multiple ligands simultaneously, but also demonstrate that GW9662 and T0070907 should not be used as reliable chemical tools to inhibit the binding of other ligands to PPARγ.