Receptor Signaling Research Articles

Difluorinated thromboxane A2 reveals crosstalk between platelet activatory and inhibitory pathways by targeting both the TP and IP receptors.

Thromboxane A2 (TXA2) is a prostanoid produced during platelet activaton, important in enhancing platelet reactivity by activation of TP receptors. However, due to the short half-life, studying TXA2 signalling is challenging. To enhance our understanding of TP receptor-mediated platelet biology, we therefore synthesised mono and difluorinated TXA2 analogues and explored their pharmacology on heterologous and endogenously expressed TP receptor function. Platelet functional and signalling responses were studied using aggregometry, Ca2+ mobilisation experiments and immunoblotting and compared with an analogue of the TXA2 precursor prostaglandin H2, U46619. Gαq/Gαs receptor signalling was determined using a bioluminescence resonance energy transfer (BRET) assay in a cell line overexpression system. BRET studies revealed that F-TXA2 and F2-TXA2 promoted receptor-stimulated TP receptor G-protein activation similarly to U46619. Unexpectedly, F2-TXA2 caused reversible aggregation in platelets, whereas F-TXA2 and U46619 induced sustained aggregation. Blocking the IP receptor switched F2-TXA2-mediated reversible aggregation into sustained aggregation. Further BRET studies confirmed F2-TXA2-mediated IP receptor activation. F2-TXA2 rapidly and potently stimulated platelet TP receptor-mediated protein kinase C/P-pleckstrin, whereas IP-mediated protein kinase A/P-vasodilator-stimulated phosphoprotein was more delayed. F-TXA2 is a close analogue to TXA2 used as a selective tool for TP receptor platelet activation. In contrast, F2-TXA2 acts on both TP and IP receptors differently over time, resulting in an initial wave of TP receptor-mediated platelet aggregation followed by IP receptor-induced reversibility of aggregation. This study reveals the potential difference in the temporal aspects of stimulatory and inhibitory pathways involved in platelet activation.

Modulation of mechanosensation by endogenous dopaminergic signaling in the lateral parabrachial nucleus in mice.

The lateral parabrachial nucleus (LPBN), a crucial hub for integrating and modulating diverse sensory information, is known to express both D1 and D2 dopamine receptors and receive dopaminergic inputs. However, the role of the LPBN's dopaminergic system in somatosensory processing remains largely unexplored. In this study, we investigated whether mechanical sensory stimulation triggers dopamine release in the LPBN and how D1- and D2-like receptor signaling in the LPBN influences mechanosensitivity in mice. We used a G-protein-coupled receptor-based dopamine sensor to monitor dopamine release in the LPBN and a von Frey filament assay to measure the mechanical threshold for nocifensive withdrawal in mouse hind paws after unilateral microinjection of D1- or D2-like receptor antagonist into the LPBN. Noxious mechanical stimulation increased the dopamine sensor signal in the LPBN. Thresholds of nocifensive withdrawal from mechanical stimulation were decreased by the D1-like receptor antagonist SCH-23390 (0.1 µg) but increased by the D2-like receptor antagonist eticlopride (1 µg). In the intraplantar capsaicin injection model that develops mechanical hypersensitivity in the injected paw, the dopamine sensor signal in the LPBN was increased, and eticlopride (1 µg) in the LPBN significantly inhibited the capsaicin-induced mechanical hypersensitivity. These results suggest that endogenous dopaminergic signaling occurs in the LPBN upon noxious mechanical stimulation, inhibiting mechanosensitivity through D1-like receptors while enhancing it through D2-like receptors. D2-like receptor signaling in the LPBN may contribute to an injury-induced increase in mechanical nociception, indicating that inhibiting the receptor within the LPBN could offer potential as a novel analgesic strategy.

Abstract C111: Characterization of kisspeptin receptor signaling pathways in cervical cancer: Unveiling novel mechanisms and therapeutic potentials

Abstract Introduction: This study delves into the complex signaling mechanisms of the kisspeptin system in cervical cancer, aiming to unravel the intricate interactions between kisspeptin and its receptor, as well as their roles in modulating cancer progression. Given the emerging significance of the kisspeptin system in tumor biology, our research seeks to illuminate how kisspeptin signaling influences cellular behaviors critical to cancer development, such as proliferation and migration. By exploring the nuanced effects of kisspeptin receptor activation, this study contributes to a deeper understanding of its therapeutic potential and underscores the importance of kisspeptin pathways in the broader context of cancer research. Methods: Was employed Bioluminiscence Resonance Energy Transfer (BRET) assays to explore the activation of the kisspeptin receptor in cervical cancer cell lines, using synthesized analogs of kisspeptin-10 for detailed signaling analysis. Functional effects were assessed through proliferation and migration assays. Additionally, we evaluated the activation or reduction in phosphorylation of specific kinases involved in tumoral processes, providing a nuanced understanding of the signaling mechanisms at play. Results: Our data demonstrate that activation of the kisspeptin receptor substantially modulates cellular proliferation and motility in cervical cancer cell lines. We uncovered novel activation of the Gz protein by kisspeptin-10, which is integral to the kisspeptin receptor function, and identified an upregulation of signaling pathways critical for cell survival and metastasis. Importantly, we observed activation of kinases such as Chk2, c-Jun, p70 S6 kinase, and RSK 1/2/3, as well as members of the STAT family, following kisspeptin-10 stimulation. This kinase activation underscores the multifaceted role of kisspeptin in tumor progression, suggesting its involvement in both pro-oncogenic and tumor-suppressive pathways, and provides direct insights into the mechanistic underpinnings of kisspeptin effect on cancer cell behavior. Conclusion: In conclusion, our study elucidates the complex role of kisspeptin-10 in cervical cancer, demonstrating its ability to modulate cellular proliferation and motility through activation of the kisspeptin receptor. The novel activation of the Gz protein and subsequent upregulation of signaling pathways associated with cell survival and metastasis highlight the intricate involvement of kisspeptin in cancer progression. Furthermore, the activation of key kinases such as Chk2, c-Jun, p70 S6 kinase, RSK 1/2/3, and STAT family members upon kisspeptin-10 stimulation reveals a dual-faceted influence on tumor dynamics, promoting both pro-oncogenic and tumor-suppressive mechanisms. These findings provide significant insights into the molecular actions of kisspeptin in cervical cancer, offering potential targets for therapeutic intervention and a deeper understanding of its role in tumor biology. Citation Format: Deisy Y. Rodríguez-Sarmiento, Pedro H. Scarpelli-Pereira, Michel Bouvier. Characterization of kisspeptin receptor signaling pathways in cervical cancer: Unveiling novel mechanisms and therapeutic potentials [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C111.

Generalized pustular psoriasis patient with a heterozygous hypomorphic MPO variant refractory to intravenous spesolimab

AbstractGeneralized pustular psoriasis (GPP) is a recurrent and sometimes life‐threatening sterile pustular disease. Because interleukin (IL)‐36 is the central cytokine in disease formation, spesolimab, which interferes with IL‐36 receptor signaling, is highly effective. Here, we report a patient with GPP with a heterozygous hypomorphic MPO variant refractory to intravenous spesolimab. Although spesolimab showed excellent clinical efficacy in resolving pre‐existing pustules and erythema, it did not suppress the emergence of new pustules and erythema, which did not decrease the peripheral blood neutrophil count, therefore bimekizumab, an anti‐IL‐17A/IL‐17F antibody, was administered after the second spesolimab infusion, which resolved the pustules and erythema. We discuss the possible reasons for the resistance mechanism to spesolimab.

A randomized phase II trial on the addition of dutasteride to combined androgen blockade therapy versus combined androgen blockade therapy alone in patients with advanced or metastatic salivary duct carcinoma – the DUCT study protocol

BackgroundSalivary duct carcinoma (SDC) is a rare and aggressive subtype of salivary gland cancer, frequently associated with incurable recurrences and distant metastases (R/M). Proliferation of SDC relies on androgen receptor (AR) signalling, prompting the use of combined androgen blockade (CAB, i.e., luteinizing hormone-releasing hormone agonist and/or AR antagonists) to R/M SDC patients. However, only a subset of patients benefits from such treatments. We have shown that response to CAB is associated with steroid 5α-reductase 1 (SRD5A1) mRNA expression. SRD5A1 catalyses the intracellular conversion of testosterone into the more potent AR-agonist dihydrotestosterone. This conversion can be inhibited by dutasteride, a potent SRD5A1-inhibitor, which is currently prescribed for benign prostatic hyperplasia. We hypothesize that repurposing dutasteride to target AR signalling in SDC could enhance therapeutic response and clinical outcome in SDC patients.MethodsThis prospective, open-label, randomized controlled phase II clinical trial, is designed to investigate whether dutasteride as an adjunct drug to CAB improves response rate and clinical outcome in patients with AR-positive R/M SDC. Patients are divided in two cohorts based on their prior systemic treatments. In cohort A, CAB-naïve patients (n = 74) will be randomly assigned to either a control arm (Arm 1) receiving CAB (goserelin 10.8 mg/3m and bicalutamide 50 mg/OD) or an experimental arm (Arm 2) where dutasteride (0.5 mg/OD) is added to the CAB regimen. In cohort B, patients with disease progression after adjuvant or first-line palliative CAB therapy (max. n = 24) will receive goserelin, bicalutamide, and dutasteride to assess whether the addition of dutasteride can overcome therapy resistance. The primary endpoints are the objective response rate and duration of response. Secondary endpoints are progression-free survival, overall survival, clinical benefit rate, quality of life, and safety. Translational research will be performed to explore molecular target expression differences and their correlation with clinical outcome.DiscussionThe DUCT study addresses an unmet medical need by investigating the repurposing of dutasteride to enhance treatment response and improve clinical outcome for patients with R/M SDC, especially those with limited alternative treatment options, such as HER2-negative cases. By repurposing a registered low-cost drug, this trial’s findings could be readily applied into clinical practice.Trial registrationClinicaltrials.gov Identifier: NCT05513365. Date of registration: August 24, 2022.Protocol versionCurrent protocol version 4.0, February 21, 2024.

Immunosuppressive effects of triptolide via interleukin-2/receptor signaling

Background Triptolide (TP) has been confirmed to possess many beneficial functions including anti-inflammation and immunosuppression. Objective The present study aimed to explore the potential involvement of IL-2/IL-2R pathway in the immunosuppressive activities of TP. Methods Cultured CTLL-2 cells were utilized to evaluate the potential benefits of TP. Then cell viability was determined by CCK-8 assay, IFN-γ level by ELISA assay, Annexin V-FITC/PI double-staining and CD25 expression by flow cytometry, and protein expression by western blotting. Additionally, rhIL-2–driven lymphocytes following ConA activation were investigated. The interactions of TP with IL-2 and IL-2Rα were investigated by binding assays and molecular dynamics simulations. Results TP treatment attenuated IFN-γ level and cell viability in both rhIL-2–induced CTLL-2 cells and rhIL-2–driven splenic lymphocytes. TP treatment increased cellular apoptosis/necrosis and cleaved PARP-1 level, while suppressed c-Myc level in rhIL-2–induced CTLL-2 cells. Additionally, TP treatment reduced CD25 expression on CTLL-2 cell surface. Notably, the phosphorylation protein levels in IL-2R signaling pathways were inhibited by TP exposure prior to rhIL-2 stimulation. SPR and BLI assays verified TP that directly bound to rhIL-2 and rmIL-2Rα, respectively. Molecular simulations suggested that TP bound at the interface of IL-2 and IL-2Rα near the hydrophobic patch composed of F62, L92 on IL-2 and L23, I46, V139 on IL-2Rα, resulting in decreased binding free energy between IL-2 and IL-2Rα. Conclusions These findings collectively emphasized that TP interfered IL-2/IL-2Rα interactions, down-regulated IL-2Rα expression, and inhibited IL-2R signaling pathways activation, thereby leading to the immune cells being desensitized to rhIL-2 and exhibiting immunosuppressive properties.

Involvement of sphingosine 1-phosphate signaling in insulin-like growth factor-II/mannose 6-phosphate receptor trafficking from endosome to the trans-Golgi network

The insulin-like growth factor II/mannose 6-phosphate (IGF-II/M6P) receptor is a multifunctional glycoprotein not only play roles in IGF-II degradation and pro-TGFβ activation but binding to and transport M6P-bearing lysosomal enzymes from the trans-Golgi network (TGN) or the cell surface to lysosomes. At present, information regarding a retrograde transport of IGF-II/M6P receptor from endosomes to the TGN is still limited. We show here that a continuous ligand-dependent activation of sphingosine 1-phosphate receptor type 3 (S1P3R) on the endosomal membranes is required for subsequent recycling back of cargo-unloaded IGF-II/M6P receptors to the TGN. We have further clarified that Gq coupled with S1P3R plays a critical role in the activation of casein kinase 2, which phosphorylates and keeps PACS1 connector protein active for the association with IGF-II/M6P receptors, which enables transport carrier formation with the aid of other adaptor proteins toward the TGN. These findings shed light on the molecular mechanism underlying how continuous activation of the S1P receptor and subsequent downstream Gq signaling regulates the retrograde transport of the empty IGF-II/M6P receptors back to the TGN.

Integrated transcriptomics and proteomics analyses reveal the ameliorative effect of hepatic damage in tilapia caused by polystyrene microplastics with chlorella addition

Fish exhibit varying responses to polystyrene microplastics (MPs) depending on particle size. Previous studies suggested that microorganisms adhering to the surface of MPs can induce toxic effects. In this study, Tilapia were exposed to MPs of control (group A), 75 nm (B), 7.5 μm (C), 750 μm (D), as well as combinations of all sizes (E) and 75 nm MPs with Chlorella vulgaris addition (F) for 7, 10 and 14 days. Histopathological changes in liver of tilapia were assessed using enzyme activities, transcriptomics and proteomics. The results showed that in groups combined MPs of different particle sizes and those supplemented with chlorella, MPs were localized on the surface of goblet cells, leading to vacuoles, constricted hepatic sinuses and nuclei displacement. Exposure to 7.5 and 750 μm MPs significantly increased the contents of fatty acid synthase (FAS), adenosine triphosphate (ATP), acetyl-CoA carboxylase (ACC), lipoprotein lipase (LPL), total cholesterol (TC), total triglyceride (TG) contents at 7 and 10 days. In particular, cytochrome p450 1a1 (EROD), reactive oxygen species (ROS) and superoxide dismutase (SOD) were markedly elevated following exposure to MPs. Apoptotic markers caspase-3, and inflammatory markers, including tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β), had a similar upward trend in comparisons of group C vs A at 7 d, group D vs A at 14 d. The peroxisome proliferator activated receptor (PPAR) signaling pathway, spliceosome, was highly enriched during the 7-day exposure of medium sized MPs, while largest MPs in the comparison of group D vs A at 14 d activated pathways such as phagosome, apoptosis, salmonella infection. Transcriptomic analysis revealed that after 14 days, the kyoto encyclopedia of genes and genomes (KEGG) pathways associated with protein processing in endoplasmic reticulum and the PPAR signaling has been significantly enriched in the Chlorella-supplemented group, which was further confirmed via the proteomic analysis. Overall, the findings highlight the size-dependent effects of MPs on histopathological changes, gene and protein expression in the liver of tilapia, and C. vulgaris effectively attenuated liver damages, likely through modulation of endoplasmic reticulum protein processing and PPAR signaling pathways.

Screening and identification of the hub genes in severe acute pancreatitis and sepsis

BackgroundSevere acute pancreatitis (SAP) is accompanied with acute onset, rapid progression, and complicated condition. Sepsis is a common complication of SAP with a high mortality rate. This research aimed to identify the shared hub genes and key pathways of SAP and sepsis, and to explore their functions, molecular mechanism, and clinical value.MethodsWe obtained SAP and sepsis datasets from the Gene Expression Omnibus (GEO) database and employed differential expression analysis and weighted gene co-expression network analysis (WGCNA) to identify the shared differentially expressed genes (DEGs). Functional enrichment analysis and protein–protein interaction (PPI) was used on shared DEGs to reveal underlying mechanisms in SAP-associated sepsis. Machine learning methods including random forest (RF), least absolute shrinkage and selection operator (LASSO) and support vector machine recursive feature elimination (SVM-RFE) were adopted for screening hub genes. Then, receiver operating characteristic (ROC) curve and nomogram were applied to evaluate the diagnostic performance. Finally, immune cell infiltration analysis was conducted to go deeply into the immunological landscape of sepsis.ResultWe obtained a total of 123 DEGs through cross analysis between Differential expression analysis and WGCNA important module. The Gene Ontology (GO) analysis uncovered the shared genes exhibited a significant enrichment in regulation of inflammatory response. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the shared genes were primarily involved in immunoregulation by conducting NOD-like receptor (NLR) signaling pathway. Three machine learning results revealed that two overlapping genes (ARG1, HP) were identified as shared hub genes for SAP and sepsis. The immune infiltration results showed that immune cells played crucial part in the pathogenesis of sepsis and the two hub genes were substantially associated with immune cells, which may be a therapy target.ConclusionARG1 and HP may affect SAP and sepsis by regulating inflammation and immune responses, shedding light on potential future diagnostic and therapeutic approaches for SAP-associated sepsis.

Shared neutrophil and T cell dysfunction is accompanied by a distinct interferon signature during severe febrile illnesses in children

Severe febrile illnesses in children encompass life-threatening organ dysfunction caused by diverse pathogens and other severe inflammatory syndromes. A comparative approach to these illnesses may identify shared and distinct features of host immune dysfunction amenable to immunomodulation. Here, using immunophenotyping with mass cytometry and cell stimulation experiments, we illustrate trajectories of immune dysfunction in 74 children with multi-system inflammatory syndrome in children (MIS-C) associated with SARS-CoV-2, 30 with bacterial infection, 16 with viral infection, 8 with Kawasaki disease, and 42 controls. We explore these findings in a secondary cohort of 500 children with these illnesses and 134 controls. We show that neutrophil activation and apoptosis are prominent in multi-system inflammatory syndrome, and that this is partially shared with bacterial infection. We show that memory T cells from patients with multi-system inflammatory syndrome and bacterial infection are exhausted. In contrast, we show viral infection to be characterized by a distinct signature of decreased interferon signaling and lower interferon receptor gene expression. Improved understanding of immune dysfunction may improve approaches to immunomodulator therapy in severe febrile illnesses in children.

Transcriptome responses to benzo[a]pyrene in liver slices of sub-arctic fish species

Due to the expanding oil-related activities, the arctic and sub-arctic marine environments are increasingly vulnerable to oil-related pollution such as accidental oil spills. These cold-water ecosystems harbor many fish species that are both ecologically and economically important such as the pelagic polar cod (Boreogadus saida), capelin (Mallotus villosus), and benthic long rough dab (Hippoglossoides platessoides). The latter two are much less studied and it is crucial to characterize their responses to oil-related contaminants and develop molecular biomarkers and genomic resources for future monitoring. In this study, liver slice preparation and culture methods were used to characterize the transcriptome responses (using RNA-seq) in capelin and long rough dab to exposures of the polycyclic aromatic hydrocarbon (PAH) compound benzo[a]pyrene (BaP). The liver slice culture and exposure experiments were performed onboard a research vessel in the Barents Sea. Strong up-regulation of genes involved in biotransformation, particularly the aryl hydrocarbon receptor signaling pathway was observed in both species. A comparison of the number of differentially expressed genes (DEGs) with previously published polar cod exposures indicates that the latter responded more strongly (higher number of genes), suggesting higher uptake and bioconcentration of BaP in the fatty liver tissue, although other factors such as differences in clearance rate could potentially affect the responses. This study provides new genomic resources and gene expression biomarkers in capelin and long rough dab, enhancing our understanding of their response mechanism to oil-related contaminants.

Differential roles of kinetic on- and off-rates in T-cell receptor signal integration revealed with a modified Fab’-DNA ligand

Antibody-derived T-cell receptor (TCR) agonists are commonly used to activate T cells. While antibodies can trigger TCRs regardless of clonotype, they bypass native T cell signal integration mechanisms that rely on monovalent, membrane-associated, and relatively weakly binding ligand in the context of cellular adhesion. Commonly used antibodies and their derivatives bind much more strongly than native peptide major histocompatibility complex (pMHC) ligands bind their cognate TCRs. Because ligand dwell time is a critical parameter that tightly correlates with physiological function of the TCR signaling system, there is a general need, both in research and therapeutics, for universal TCR ligands with controlled kinetic binding parameters. To this end, we have introduced point mutations into recombinantly expressed α-TCRβ H57 Fab to modulate the dwell time of monovalent Fab binding to TCR. When tethered to a supported lipid bilayer via DNA complementation, these monovalent Fab’-DNA ligands activate T cells with potencies well-correlated with their TCR binding dwell time. Single-molecule tracking studies in live T cells reveal that individual binding events between Fab'-DNA ligands and TCRs elicit local signaling responses closely resembling native pMHC. The unique combination of high on- and off-rates of the H57 R97L mutant enables direct observations of cooperative interplay between ligand binding and TCR-proximal condensation of the linker for activation of T cells, which is not readily visualized with pMHC. This work provides insights into how T cells integrate kinetic information from TCR ligands and introduces a method to develop affinity panels for polyclonal T cells, such as cells from a human patient.

Novel Treatment Strategies for Low-Risk Metastatic Castration-Sensitive Prostate Cancer

Background: The treatment strategy for metastatic castration-sensitive prostate cancer (mCSPC) has changed significantly in recent years. Based on various guidelines, an upfront androgen receptor signaling inhibitor (ARSI) is the first choice, but in patients of Asian descent, including Japanese patients, there are a certain number of cases in which androgen deprivation therapy (ADT) and CAB are more effective. If patients can be identified who show a marked response to ADT within 12 weeks after the initiation of ADT, which is the inclusion criterion for ARSI clinical trials targeting mCSPC, it would be valuable from an economic standpoint. Methods: A total of 218 patients with pure prostate adenocarcinoma and treated with ADT at the Kanazawa University Hospital between January 2000 and December 2020 were included in this study. As a risk classification for mCSPC, in addition to the LATITUDE and CHAARTED criteria, we used the castration-sensitive prostate cancer classification proposed by Kanazawa University (Canazawa), developed by the Department of Urology of Kanazawa University. The Canazawa classification was based on three factors: Gleason pattern 5, bone scan index (BSI) ≥ 1.5, and lactate dehydrogenase (LDH) ≥ 300 IU/L. It defined patients with one factor or less as low-risk and patients with two or three factors as high-risk. The overall survival (OS) and time to castration resistance (TTCR) were estimated retrospectively using the Kaplan–Meier method, and factors associated with TTCR were identified using univariate and multivariate analyses. Results: The median follow-up period was 40.4 months, the median OS period was 85.2 months, and the median TTCR period was 16.4 months. The Canazawa risk classification provided the clearest distinction between the OS and TTCR in mCSPC patients. Multivariate analysis revealed a decrease in PSA levels of <95% at 12 weeks after ADT initiation and was a predictor of short TTCR in low-risk, low-volume patients across all risk classifications. Conclusion: The Canazawa classification differentiated the prognosis of mCSPC patients more clearly. A PSA reduction rate of <95% at 12 w after starting ADT in low-risk, low-volume patients of all risk classifications was significantly shorter than the TTCR. We propose a new treatment strategy, in which patients with low-risk mCSPC are treated with ADT and switched to ARSIs based on the rate of PSA reduction at 12 w.

DCAF2 is essential for the development of uterine epithelia and mouse fertility

IntroductionThe successful outcome of a pregnancy depends on the proper functioning uterine epithelium. DNA damage binding protein 1 and cullin 4-associated factor 2 (DCAF2), a conserved substrate receptor for the cullin 4-RING E3 ubiquitin ligase (CRL4) complex, is essential for maintaining genome stability by facilitating ubiquitin-mediated degradation of substrates.MethodsTo better understand the physiological role of DCAF2 in female reproduction, we conducted a study using mice with conditional knockout (cKO) of DCAF2 in the uterus using the progesterone receptor Cre (PgrCre/+) mouse model.ResultsOur results showed the cKO mice were completely infertile, despite having ovarian function. The cKO mice exhibited severely thin uteri, demonstrating notable defects in both the uterine epithelium and a lack of glands. In addition, there were impaired proliferation and differentiation of epithelial cells in the cKO mice, ultimately resulting in failed implantation. Moreover, through deciphering the uterine transcriptome of cKO mice, we revealed crucial differentially expressed genes associated with steroid signaling. Further experiments have demonstrated cKO mice exhibit elevated uterine PGR signaling and reduced estrogen receptor signaling, although the levels of progesterone and estrogen remained unaltered. These alterations may contribute to defects in epithelium.DiscussionOverall, our findings highlight a previously unrecognized but indispensable role for DCAF2 in the development of uterine luminal and glandular epithelium by orchestrating PGR and estrogen receptor responses. Its deficiency in the uterus leads to mouse infertility.

Effects of manipulating prefrontal activity and dopamine D1 receptor signaling in an appetitive feature-negative discrimination learning task.

Effects of manipulating prefrontal activity and dopamine D1 receptor signaling in an appetitive feature-negative discrimination learning task.

Deep PSA response and extended time‐to‐nadir as robust predictors of survival in Asian patients with de novo metastatic hormone‐sensitive prostate cancer receiving upfront intensified treatment

AbstractIntroductionIn de novo metastatic hormone‐sensitive prostate cancer (mHSPC) treated with upfront intensification using androgen receptor signaling inhibitor or chemotherapy (Docetaxel), achieving a PSA nadir less than 0.2 ng/mL, indicative of superior survival in trials, may often be unattainable in real‐world settings. We explored the predictive value of the degree of PSA decline and time to PSA nadir (TTPN) on oncological outcomes.MethodsA prospectively maintained database of consecutive prostate cancer cases in Hong Kong was accessed. Patients diagnosed with de novo mHSPC from 2016 to 2022 and treated with upfront intensification were included in this analysis. Landmark analysis on PSA kinetics at 6‐months following treatment intensification was performed. They were classified based on 1) TTPN (≥6 months vs. <6 months), and 2) a combined response (deep responders achieving both ≥95% PSA decline and TTPN ≥ 6 months vs. shallow responders). Multivariable regression analysis was employed to identify the effects of confounders.FindingsA total of 131 patients were included in this analysis. Classifying patients by combined response best predicted survival outcomes. Deep responders had better progression‐free survival (HR = 0.56; 95%CI = 0.34–0.91; p = 0.019), overall survival (HR = 0.50; 95%CI = 0.26–0.97; p = 0.036), and cancer‐specific survival (HR = 0.43; 95%CI = 0.19–0.99; p = 0.042). Difference in overall survival remained significant after adjustment in multivariable regression analysis.ConclusionOur analysis demonstrates that alternative PSA targets can predict treatment response and survival outcomes in de novo mHSPC patients in a real‐world setting, providing valuable information for patient counselling and potentially guiding future trial design.

In vitro immuno-prevention of nitration/dysfunction of myogenic stem cell activator HGF, towards developing a strategy for age-related muscle atrophy.

In response to peroxynitrite (ONOO-) generation, myogenic stem satellite cell activator HGF (hepatocyte growth factor) undergoes nitration of tyrosine residues (Y198 and Y250) predominantly on fast IIa and IIx myofibers to lose its binding to the signaling receptor c-met, thereby disturbing muscle homeostasis during aging. Here we show that rat anti-HGF monoclonal antibody (mAb) 1H41C10, which was raised in-house against a synthetic peptide FTSNPEVRnitroY198EV, a site well-conserved in mammals, functions to confer resistance to nitration dysfunction on HGF. 1H41C10 was characterized by recognizing both nitrated and non-nitrated HGF with different affinities as revealed by Western blotting, indicating that the paratope of 1H41C10 may bind to the immediate vicinity of Y198. Subsequent experiments showed that 1H41C10-bound HGF resists peroxynitrite-induced nitration of Y198. A companion mAb-1H42F4 presented similar immuno-reactivity, but did not protect Y198 nitration, and thus served as the control. Importantly, 1H41C10-HGF also withstood Y250 nitration to retain c-met binding and satellite cell activation functions in culture. The Fab region of 1H41C10 exerts resistivity to Y250 nitration possibly due to its localization in the immediate vicinity to Y250, as supported by an additional set of experiments showing that the 1H41C10-Fab confers Y250-nitration resistance which the Fc segment does not. Findings highlight the invitro preventive impact of 1H41C10 on HGF nitration-dysfunction that strongly impairs myogenic stem cell dynamics, potentially pioneering cogent strategies for counteracting or treating age-related muscle atrophy with fibrosis (including sarcopenia and frailty) and the therapeutic application of investigational HGF drugs.

Comparative analysis of formyl peptide receptor 1 and formyl peptide receptor 2 reveals shared and preserved signalling profiles.

The pattern recognition receptors, formyl peptide receptors, FPR1 and FPR2, are G protein-coupled receptors that recognize many different pathogen- and host-derived ligands. While FPR1 conveys pro-inflammatory signals, FPR2 is linked with pro-resolving outcomes. To analyse how the two very similar FPRs exert opposite effects in modulating inflammatory responses despite their high homology, a shared expression profile on immune cells and an overlapping ligand repertoire, we questioned whether the signalling profile differs between these two receptors. We deduced EC50 and Emax values for synthetic, pathogen-derived and host-derived peptide agonists for both FPR1 and FPR2 and analysed them within the framework of biased signalling. We furthermore investigated whether FPR isoform-specific agonists affect the ex vivo lifespan of human neutrophils. The FPRs share a core signature across signalling pathways. Whereas the synthetic WKYMVm and formylated peptides acted as potent agonists at FPR1, and at FPR2, only WKYMVm was a full agonist. Natural FPR2 agonists, irrespective of N-terminal formylation, displayed lower activity ratios, suggesting an underutilized signalling potential of this receptor. FPR2 agonism did not counteract LPS-induced neutrophil survival, indicating that FPR2 activation per se is not linked with a pro-resolving function. Activation of FPR1 and FPR2 by a representative agonist panel revealed a lack of a receptor-specific signalling texture, challenging assumptions about distinct inflammatory profiles linked to specific receptor isoforms, signalling patterns or agonist classes. These conclusions are restricted to the specific agonists and signalling pathways examined.

Claustrum and dorsal endopiriform cortex complex cell-identity is determined by Nurr1 and regulates hallucinogenic-like states in mice

The Claustrum/dorsal endopiriform cortex complex (CLA) is an enigmatic brain region with extensive glutamatergic projections to multiple cortical areas. The transcription factor Nurr1 is highly expressed in the CLA, but its role in this region is not understood. By using conditional gene-targeted mice, we show that Nurr1 is a crucial regulator of CLA neuron identity. Although CLA neurons remain intact in the absence of Nurr1, the distinctive gene expression pattern in the CLA is abolished. CLA has been hypothesized to control hallucinations, but little is known of how the CLA responds to hallucinogens. After the deletion of Nurr1 in the CLA, both hallucinogen receptor expression and signaling are lost. Furthermore, functional ultrasound and Neuropixel electrophysiological recordings revealed that the hallucinogenic-receptor agonists’ effects on functional connectivity between prefrontal and sensorimotor cortices are altered in Nurr1-ablated mice. Our findings suggest that Nurr1-targeted strategies provide additional avenues for functional studies of the CLA.

Evaluation of the clinical efficacy of Pediococcus acidilactici CCFM6432 in alleviating depression

Aim: Accumulating evidence highlights the crucial role of the “gut-brain axis” and emphasizes the potential of dietary interventions to improve brain health through this pathway. This study assesses the effects of the probiotic Pediococcus acidilactici CCFM6432 on mood, sleep, and gastrointestinal function in patients with depressive disorder. Methods: This clinical trial is a randomized, placebo-controlled study (Registration: ChiCTR2300071025). It enrolled 39 adult patients diagnosed with depressive disorder, who were randomly assigned to either the placebo control group (n = 19) or the CCFM6432 intervention group (n = 20). The intervention period spanned four weeks. Assessments were conducted at both the beginning and end of the trial, including comprehensive questionnaire evaluations and the collection of serum and fecal samples. Results: In comparison to the placebo, treatment with CCFM6432 significantly decreased depression and anxiety scores, as well as ameliorated gastrointestinal dysfunction and poor sleep quality commonly associated with mood disorders. Microbiota analysis revealed an increase in species richness without notable changes in overall diversity, yet Pediococcus species was found to be more abundant post-treatment. Functional analysis indicated reduced activity in the NOD-like receptor signaling pathway, suggesting anti-inflammatory effects induced by the probiotic. Metabolomic profiling identified elevated levels of fecal lactic acid, which correlated with lower Hospital Anxiety and Depression Scale (HADS) scores, thereby linking probiotic metabolism to mood enhancement. Conclusion: These findings imply that CCFM6432 may improve brain function by modulating gut microbiota and their mediated immune homeostasis, underscoring its potential as an adjunctive treatment for mental disorders.