Specific Receptors Research Articles

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.

Functional characterization supports multiple evolutionary origins of pheromone receptors in bark beetles.

Chemical communication using pheromones is thought to have contributed to the diversification and speciation of insects. The species-specific pheromones are detected by specialized pheromone receptors. Whereas the evolution and function of pheromone receptors have been extensively studied in Lepidoptera, only a few pheromone receptors have been identified in beetles, which limits our understanding of their evolutionary histories and physiological functions. To shed light on these questions, we aimed to functionally characterize potential pheromone receptors in the spruce bark beetle Ips typographus ('Ityp') and explore their evolutionary origins and molecular interactions with ligands. Males of this species release an aggregation pheromone comprising 2-methyl-3-buten-2-ol and (4S)-cis-verbenol, which attracts both sexes to attacked trees. Using two systems for functional characterization, we show that the highly expressed odorant receptor (OR) ItypOR41 responds specifically to (4S)-cis-verbenol, with structurally similar compounds eliciting minor responses. We next targeted the closely related ItypOR40 and ItypOR45. Whereas ItypOR40 was unresponsive, ItypOR45 showed an overlapping response profile with ItypOR41, but a broader tuning. Our phylogenetic analysis shows that these ORs are present in a different OR clade as compared to all other known beetle pheromone receptors, suggesting multiple evolutionary origins of pheromone receptors in bark beetles. Next, using computational analyses and experimental validation, we reveal two amino acid residues (Gln179 and Trp310) that are important for ligand binding and pheromone specificity of ItypOR41 for (4S)-cis-verbenol, possibly via hydrogen bonding to Gln179. Collectively, our results shed new light on the origins, specificity, and ligand binding mechanisms of pheromone receptors in beetles.

Abstract A049: Collagen-driven kinome reprogramming reveals unique, actionable DDR1-signaling dependencies in pancreatic cancer cells

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDA) is the 3rd most common cause of cancer death in the United States, with a 5-year survival rate of only 13%, in part due to late detection and metastatic dissemination at early stages of progression. Most PDA tumors exhibit a dense fibro-inflammatory stroma consisting of fibroblasts, immune cells, and a dense collagen-rich extracellular matrix (ECM) that regulate disease progression. How distinct collagens (COLs) influence PDA progression remains unclear. COLs signal via specific cell surface receptors, of which the Discoidin Domain Receptors (DDRs) constitute a unique family of collagen-binding receptor tyrosine kinases (RTKs). DDR1 is expressed by PDA cancer cells, while DDR2 is expressed by mesenchymal cells. DDR1 is activated by both basement membrane COL (e.g. COL4) and fibrillar COLs (e.g. COLs 1, 2, 11). Compared to most RTKs, relatively little is understood about differential ligand activation and signaling downstream of DDRs. Our working hypothesis is that switches in ECM collagen composition over the course of PDA progression induce changes in DDR1-intracellular signaling cascades, which may reveal unexplored therapeutic susceptibilities to target and eliminate PDA cancer cells. Methods and Recent Advances: Using genetically engineered mouse models of PDA, we previously found that genetic ablation of Ddr1 impedes tumor progression, blocking the transition from well-differentiated to poorly-differentiated adenocarcinoma and, as a result, metastasis. Moreover, we showed that xenografts of DDR1-expressing human PDA cell lines display enhanced tumor growth exclusively when implanted within a COL1 scaffold. Leveraging an innovative high-throughput kinase-activity mapping (HT-KAM) platform and kinase network resource database (PhosphoAtlas), we started investigating mechanisms of differential activation of DDR1 by distinct COLs, including COL1 and COL11, which is an understudied fibrillar collagen that is prominent in the stroma of late-stage, metastatic PDA. New, Unpublished Findings: Using several PDA cell line models with or without DDR1 expression, our results indicate that DDR1 activates two distinct signaling networks: (1) a conserved, coordinated response that is modestly activated by COL1 but is hyperactivated by COL11 (e.g., ERBB, AKT, MEK/ERK, SRC), and (2) a unique set of phospho-signaling nodes that are only induced by COL11 –and not COL1 (e.g., specific RTKs and PKCs). Several of these kinases are associated with cancer cell proliferation and survival, as well as EMT induction, in part illuminating the malignancy-promoting effects of DDR1 in late-stage PDA in response to changes in COL composition. Conclusion: Differential activation of DDR1 represents a new paradigm on how distinct fibrillar COLs within the TME may drive PDA cell signaling. We are actively exploring how distinct COLs differentially regulate PDA tumor growth and metastatic behavior via DDR1, and how specific kinase-targeting interventions may prevent malignant phenotypes or induce tumor cell death. Citation Format: Anjum Sohail, Yeonjoo Hwang, Denise P Munoz, Yoshihiro Ishikawa, Rafael Fridman, Howard Crawford, Jean-Philippe Coppe. Collagen-driven kinome reprogramming reveals unique, actionable DDR1-signaling dependencies in pancreatic cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A049.

Antigenic peptide–thioredoxin fusion chimeras for <i>in vitro</i> stimulus of CD4<sup>+</sup> TCR<sup>+</sup> Jurkat T-cells

Study of CD4+ T-cell response and T-cell receptor (TCR) specificity is crucial for understanding etiology of immune-mediated diseases and developing targeted therapies. However, solubility, accessibility, and stability of synthetic antigenic peptides used in T-cell assays may be a critical point in such studies. Here we present a T-cell activation reporter system using recombinant proteins containing antigenic epitopes fused with bacterial thioredoxin (trx-peptides) and obtained by bacterial expression. We report that co-incubation of CD4+ HA1.7 TCR+ reporter Jurkat 76 TRP-cells with CD80+ HLA-DRB1*01:01+ HeLa-cells or CD4+ Ob.1A12 TCR+ Jurkat 76 TRP with CD80+ HLA-DRB1*15:01+ HeLa-cells resulted in activation of reporter Jurkat 76 TPR after addition of recombinant trx-peptide fusion proteins, containing TCR-specific epitopes. Trx-peptides were comparable with corresponding synthetic peptides in their capacity to activate Jurkat 76 TPR. These data demonstrate that thioredoxin as a carrier protein (trx) for antigenic peptides exhibits minimal interference with recognition of MHC-specific peptides by TCRs and consequent T-cell activation. Our findings highlight potential feasibility of trx-peptides as a reagent for assessing the immunogenicity of antigenic fragments.

Postprandial metabolomics analysis reveals disordered serotonin metabolism in post-bariatric hypoglycemia.

Bariatric surgery is a potent therapeutic approach for obesity and type 2 diabetes but can be complicated by post-bariatric hypoglycemia (PBH). PBH typically occurs 1 to 3 hours after meals, in association with exaggerated postprandial levels of incretins and insulin. To identify mediators of disordered metabolism in PBH, we analyzed plasma metabolome in fasting state and 30 and 120 minutes after mixed meal in 3 groups: PBH (n = 13), asymptomatic post-RYGB (n = 10), and non-surgical controls (n = 8). In the fasting state, multiple tricarboxylic acid cycle intermediates and the ketone beta-hydroxybutyrate were increased by 30% to 80% in PBH vs. asymptomatic. Conversely, multiple amino acids (BCAA, tryptophan) and polyunsaturated lipids were reduced by 20% to 50% in PBH versus asymptomatic. Tryptophan-related metabolites, including kynurenate, xanthurenate, and serotonin, were reduced by 2- to 10-fold in PBH in fasting state. Postprandially, plasma serotonin was uniquely increased by 1.9-fold in PBH versus asymptomatic post-RYGB. In mice, serotonin administration lowered glucose and increased plasma insulin and GLP-1. Moreover, serotonin-induced hypoglycemia in mice was blocked by the nonspecific serotonin receptor antagonist cyproheptadine and the specific serotonin receptor 2 antagonist ketanserin. Together these data suggest that increased postprandial serotonin may contribute to the pathophysiology of PBH and provide a potential therapeutic target. NIH grant R01 DK121995, NIH grant P30 DK036836 (Diabetes Research Center grant, Joslin Diabetes Center), and Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP grant 2018/22111-2.

Capsaicin modulates TRPV1, induces β-defensin expression, and regulates NF-κB in oral senescent cells and a murine model.

Aging is associated with a decline in oral immune function, marked by reduced levels of antimicrobial peptides such as defensins. Capsaicin, a bioactive component found in chili peppers, has been theorized to modulate immune responses through specific receptor pathways. This study examined the effects of aging on oral defensin levels and the potential mitigating role of capsaicin, mediated by the immune response in oral tissues. We conducted a comparative analysis between young and aged mice, with or without capsaicin supplementation, for 3 months. The effect of capsaicin was also studied in vitro in senescence-induced human oral keratinocytes. We found that aging did not reduce defensin levels uniformly but did so in some instances. Capsaicin treatment increased defensin levels in these cases, potentially through transient receptor potential cation channel subfamily V member 1 (TRPV1)-mediated pathways in the oral cavity. Capsaicin supplementation may counteract age-related declines in oral defensin levels, enabling the maintenance of oral immune function during aging.

Endothelial estrogen - myocardial cGMP axis critically determines angiogenesis and cardiac performance during pressure-overload.

Estrogen exerts beneficial cardiovascular effects by binding to specific receptors on various cells to activate nuclear and non-nuclear actions. Estrogen receptor α (ERα) non-nuclear signaling confers protection against heart failure remodeling, involving myocardial cyclic guanosine monophosphate (cGMP) - cGMP-dependent protein kinase G (PKG) activation; however, its tissue-specific role remains elusive. Herein, we examined the cell type-specific role of ERα non-nuclear signaling in estrogen-conferred protection against heart failure. We first assessed the tissue-specific impacts of ERα in estrogen's cardiac benefits, utilizing endothelial ERα deletion (ERαf/f/Tie2Cre+) and myocyte ERα deletion (ERαf/f/αMHCCre+) female mice. Female mice were ovariectomized and the effect of estradiol (E2) was assessed in hearts exposed to 3week pressure-overload (TAC). E2 failed to improve cardiac function in ERαf/f/Tie2Cre+ TAC hearts but provided benefits in ERαf/f/αMHCCre+ TAC hearts, indicating that endothelial ERα is essential. We next assessed the role of non-nuclear signaling in endothelial cells, employing animals with endothelial-specific inactivation of ERα non-nuclear signaling (ERαKI/KI/Tie2Cre+). Female OVX mice were supplemented with E2 and subjected to 3-week TAC. ERαKI/KI/Tie2Cre+ TAC hearts revealed exacerbated cardiac dysfunction and reduced myocardial PKG activity as compared to littermate TAC hearts, which was associated with attenuated myocardial induction of vascular endothelial growth factor (VEGF) and angiogenesis as assessed with CD31-stained capillary density. This phenotype of ERαKI/KI/Tie2Cre+ was rescued by myocardial PKG activation from chronic treatment with soluble guanylate cyclase (sGC) stimulator. We performed co-culture experiments to determine endothelial-cardiomyocyte interactions. VEGF induction by E2 in cardiac myocytes required co-existence of intact endothelial ERα signaling in a NOS-dependent manner. On the other hand, VEGF was induced in myocytes directly with an sGC stimulator in the absence of endothelial cells. An endothelial estrogen - myocardial cGMP axis stimulates angiogenic response and improves cardiac performance during pressure-overload.

Key characteristics of carcinogens meet hallmarks for prevention-cutting the Gordian knot

The complexity of cancer requires a comprehensive approach to understand its diverse manifestations and underlying mechanisms. Initially outlined by Hanahan and Weinberg in 2000 and updated in 2010, the hallmarks of cancer provide a conceptual basis for understanding inherent variability in cancer biology. Recent expansions have further elucidated additional hallmarks, including phenotypic plasticity and senescent cells. The International Agency for Research on Cancer (IARC) has identified the key characteristics of carcinogens (KCCs) to evaluate their carcinogenic potential. We analyzed chemicals of concern for environmental exposure that interact with specific receptors to induce genomic instability, epigenetic alterations, immune suppression, and receptor-mediated effects, thereby contributing to chronic inflammation. Despite their varying degrees of carcinogenicity, these chemicals have similar KCC profiles. Our analysis highlights the pivotal role of receptor binding in activating most other KCCs, underscoring their significance in cancer initiation. Although KCCs are associated with early molecular or cellular events, they do not encompass processes directly linked to full cellular malignancy. Thus, there is a need to integrate clear endpoints that anchor KCCs to the acquisition of a complete malignant phenotype into chemical testing. From the perspective of toxicology and cancer research, an all-encompassing strategy that incorporates both existing and novel KCCs and cancer hallmarks is essential to enable the targeted identification of prevalent carcinogens and facilitate zone-specific prevention strategies. To achieve this goal, collaboration between the KCC and cancer hallmarks communities becomes essential.

Vγ6/Vδ1+ γδ T cells protect from angiotensin II effects on blood pressure and endothelial function in mice.

γδ T cells mediate angiotensin II (AngII)-induced hypertension and vascular injury. γδ T cells expressing specific T-cell receptor (TCR) variable (V) γ chains develop in several waves in the thymus and migrate to specific or diverse tissues. We hypothesized that γδ T cells expressing specific Vγ subtypes in perivascular tissue mediate AngII hypertensive effects. C57BL/6J male mice were infused or not with AngII (490 ng/kg/min, subcutaneously) for 14 days. γδ T-cell Vγ subtypes were profiled by flow cytometry in the spleen, descending thoracic aorta with adherent perivascular adipose tissue (DTAo/PVAT) and mesenteric vessels (MV)/PVAT. Other sets of AngII-infused mice were injected with control or specific anti-Vγ6 or Vγ4 antibodies. Blood pressure (BP) was determined by telemetry, and mesenteric artery function and remodeling by pressurized myography. Vγ6/Vδ1+ γδ T cells represented more than 50% of the γδ T-cell Vγ subtypes in DTAo/PVAT and MV/PVAT, whereas Vγ1/2+, Vγ4+ and Vγ6/Vδ1+ γδ T cells were the most abundant Vγ subtypes in the spleen. The frequency of Vγ6/Vδ1+ γδ T cells was increased at least 1.5-fold in the spleen and DTAo/PVAT, and tended to increase in MV/PVAT by AngII. A majority of Vγ6/Vδ1+ γδ T cells were activated in perivascular tissues. Vγ6/Vδ1+ γδ T-cell neutralization caused a steeper BP elevation and greater mesenteric artery endothelial dysfunction in mice infused with AngII. This was associated with more than three-fold increase in activated Vγ6/Vδ1- γδ T cells in perivascular tissues. Depletion of Vγ4+ γδ T cells did not alter AngII detrimental effects. Vγ6/Vδ1+ γδ T cells reduce the BP elevation and endothelial dysfunction induced by AngII infusion.

Mesenchymal stem cell cryopreservation with cavitation-mediated trehalose treatment

Dimethylsulfoxide (DMSO) has conventionally been used for cell cryopreservation both in research and in clinical applications, but has long-term cytotoxic effects. Trehalose, a natural disaccharide, has been proposed as a non-toxic cryoprotectant. However, the lack of specific cell membrane transporter receptors inhibits transmembrane transport and severely limits its cryoprotective capability. This research presents a method to successfully deliver trehalose into mesenchymal stem cells (MSCs) using ultrasound in the presence of microbubbles. The optimised trehalose concentration was shown to be able to not only preserve membrane integrity and cell viability but also the multipotency of MSCs, which are essential for stem cell therapy. Confocal imaging revealed that rhodamine-labelled trehalose was transported into cells rather than simply attached to the membrane. Additionally, the membranes were successfully preserved in lyophilised cells. This study demonstrates that ultrasonication with microbubbles facilitated trehalose delivery, offering promising cryoprotective capability without the cytotoxicity associated with DMSO-based methods.

JAK inhibitor selectivity: new opportunities, better drugs?

Cytokines function as communication tools of the immune system, serving critical functions in many biological responses and shaping the immune response. When cytokine production or their biological activity goes awry, the homeostatic balance of the immune response is altered, leading to the development of several pathologies such as autoimmune and inflammatory disorders. Cytokines bind to specific receptors on cells, triggering the activation of intracellular enzymes known as Janus kinases (JAKs). The JAK family comprises four members, JAK1, JAK2, JAK3 and tyrosine kinase 2, which are critical for intracellular cytokine signalling. Since the mid-2010s multiple JAK inhibitors have been approved for inflammatory and haematological indications. Currently, approved JAK inhibitors have demonstrated clinical efficacy; however, improved selectivity for specific JAKs is likely to enhance safety profiles, and different strategies have been used to accomplish enhanced JAK selectivity. In this update, we discuss the background of JAK inhibitors, current approved indications and adverse effects, along with new developments in this field. We address the issue of JAK selectivity and its relevance in terms of efficacy, and describe new modalities of JAK targeting, as well as new aspects of JAK inhibitor action.

SARS-CoV-2 Genotyping Highlights the Challenges in Spike Protein Drift Independent of Other Essential Proteins

As of 2024, SARS-CoV-2 continues to propagate and drift as an endemic virus, impacting healthcare for years. The largest sequencing initiative for any species was initiated to combat the virus, tracking changes over time at a full virus base-pair resolution. The SARS-CoV-2 sequencing represents a unique opportunity to understand selective pressures and viral evolution but requires cross-disciplinary approaches from epidemiology to functional protein biology. Within this work, we integrate a two-year genotyping window with structural biology to explore the selective pressures of SARS-CoV-2 on protein insights. Although genotype and the Spike (Surface Glycoprotein) protein continue to drift, most SARS-CoV-2 proteins have had few amino acid alterations. Within Spike, the high drift rate of amino acids involved in antibody evasion also corresponds to changes within the ACE2 binding pocket that have undergone multiple changes that maintain functional binding. The genotyping suggests selective pressure for receptor specificity that could also confer changes in viral risk. Mapping of amino acid changes to the structures of the SARS-CoV-2 co-transcriptional complex (nsp7-nsp14), nsp3 (papain-like protease), and nsp5 (cysteine protease) proteins suggest they remain critical factors for drug development that will be sustainable, unlike those strategies targeting Spike.

Medicinally Privileged Natural Chalcones: Abundance, Mechanisms of Action, and Clinical Trials.

Chalcones have been utilized for centuries as foods and medicines across various cultures and traditions worldwide. This paper concisely overviews their biosynthesis as specialized metabolites in plants and their significance, potential, efficacy, and possibility as future medicines. This is followed by a more in-depth exploration of naturally occurring chalcones and their corresponding mechanisms of action in human bodies. Based on their mechanisms of action, chalcones exhibit many pharmacological properties, including antioxidant, anti-inflammatory, anticancer, antimalarial, antiviral, and antibacterial properties. Novel naturally occurring chalcones are also recognized as potential antidiabetic drugs, and their effect on the GLUT-4 transporter is investigated. In addition, they are examined for their anti-inflammatory effects, focusing on chalcones used for future pharmaceutical utilization. Chalcones also bind to specific receptors and toxins that prevent bacterial and viral infections. Chalcones exhibit physiological protective effects on the biological degradation of different systems, including demyelinating neurodegenerative diseases and preventing hypertension or hyperlipidemia. Chalcones that are/were in clinical trials have been included as a separate section. By revealing the many biological roles of chalcones and their impact on medicine, this paper underlines the significance of naturally occurring chalcones and their extension to patient care, providing the audience with an index of topic-relevant information.

STAN, a computational framework for inferring spatially informed transcription factor activity.

Transcription factors (TFs) drive significant cellular changes in response to environmental cues and intercellular signaling. Neighboring cells influence TF activity and, consequently, cellular fate and function. Spatial transcriptomics (ST) captures mRNA expression patterns across tissue samples, enabling characterization of the local microenvironment. However, these datasets have not been fully leveraged to systematically estimate TF activity governing cell identity. Here, we present STAN ( S patially informed T ranscription factor A ctivity N etwork), a linear mixed-effects computational method that predicts spot-specific, spatially informed TF activities by integrating curated TF-target gene priors, mRNA expression, spatial coordinates, and morphological features from corresponding imaging data. We tested STAN using lymph node, breast cancer, and glioblastoma ST datasets to demonstrate its applicability by identifying TFs associated with specific cell types, spatial domains, pathological regions, and ligand‒receptor pairs. STAN augments the utility of STs to reveal the intricate interplay between TFs and spatial organization across a spectrum of cellular contexts.

Radiotracer Innovations in Breast Cancer Imaging: A Review of Recent Progress.

This review focuses on the pivotal role of radiotracers in breast cancer imaging, emphasizing their importance in accurate detection, staging, and treatment monitoring. Radiotracers, labeled with radioactive isotopes, are integral to various nuclear imaging techniques, including positron emission tomography (PET) and positron emission mammography (PEM). The most widely used radiotracer in breast cancer imaging is 18F-fluorodeoxyglucose (18F-FDG), which highlights areas of increased glucose metabolism, a hallmark of many cancer cells. This allows for the identification of primary tumors and metastatic sites and the assessment of tumor response to therapy. In addition to 18F-FDG, this review will explore newer radiotracers targeting specific receptors, such as estrogen receptors or HER2, which offer more personalized imaging options. These tracers provide valuable insights into the molecular characteristics of tumors, aiding in tailored treatment strategies. By integrating radiotracers into breast cancer management, clinicians can enhance early disease detection, monitor therapeutic efficacy, and guide interventions, ultimately improving patient outcomes. Ongoing research aimed at developing more specific and sensitive tracers will also be highlighted, underscoring their potential to advance precision medicine in breast cancer care.

E3 ligases RNF43 and ZNRF3 display differential specificity for endocytosis of Frizzled receptors.

The transmembrane E3 ligases RNF43 and ZNRF3 perform key tumour suppressor roles by inducing endocytosis of members of the Frizzled (FZD) family, the primary receptors for WNT. Loss-of-function mutations in RNF43 and ZNRF3 mediate FZD stabilisation and a WNT-hypersensitive growth state in various cancer types. Strikingly, RNF43 and ZNRF3 mutations are differentially distributed across cancer types, raising questions about their functional redundancy. Here, we compare the efficacy of RNF43 and ZNRF3 of targeting different FZDs for endocytosis. We find that RNF43 preferentially down-regulates FZD1/FZD5/FZD7, whereas ZNRF3 displays a preference towards FZD6. We show that the RNF43 transmembrane domain (TMD) is a key molecular determinant for inducing FZD5 endocytosis. Furthermore, a TMD swap between RNF43 and ZNRF3 re-directs their preference for FZD5 down-regulation. We conclude that RNF43 and ZNRF3 preferentially down-regulate specific FZDs, in part by a TMD-dependent mechanism. In accordance, tissue-specific expression patterns of FZD homologues correlate with the incidence of RNF43 or ZNRF3 cancer mutations in those tissues. Consequently, our data point to druggable vulnerabilities of specific FZD receptors in RNF43- or ZNRF3-mutant human cancers.

Cryptic female choice in response to male pheromones in Drosophila melanogaster.

Females control the paternity of their offspring by selectively mating with males they perceive to be of high quality. In species where females mate with multiple males in succession, females may bias offspring paternity by favoring the sperm of one male over another, a process known as cryptic female choice.1 While evidence of cryptic female choice exists in multiple taxa, the mechanisms underlying this process have remained difficult to unravel.2 Understanding cryptic female choice requires demonstration of a female-driven post-mating bias in sperm use and paternity and a causal link between this bias and male cues.3 In this study, we present evidence of cryptic female choice in female Drosophila melanogaster. Through experiments utilizing transgenic males expressing fluorescent sperm, we observed that exposure to attractive males between matings prompts females to expel the ejaculate of their initial mate more rapidly than in the presence of less attractive males. While doing so, females exhibit a bias in sperm storage against their first mate, thereby favoring the paternity of their subsequent mate. Our findings reveal that females adjust the timing of ejaculate expulsion in response to male pheromones in their environment, specifically heptanal and 11-cis-vaccenyl acetate, which are sensed by females through specific odorant receptors. We provide a cryptic female choice mechanism allowing a female to modulate the share of paternity of her first mate depending on the sensing of the quality of potential mates in her environment. These findings showcase that paternity can be influenced by events beyond copulation.

Leveraging chemotherapy-induced PD-L1 upregulation to potentiate targeted PD-L1 degradation using nanoparticle-based targeting chimeras

The combination of nab-paclitaxel and the programmed death-ligand 1(PD-L1) antibody atezolizumab showed limited benefits in clinical trials involving PD-L1-positive triple-negative breast cancer patients. This observed lack of success is attributed to the upregulation of PD-L1 on tumor cells induced by paclitaxel, leading to resistance against PD-L1 antibodies. Here, we introduce nanoparticle-based PD-L1 targeting chimeras (NanoTACPD-L1) to induce PD-L1 degradation instead of blockade. NanoTACPD-L1 initiates endocytosis independent of specific lysosome-targeting receptors, and delivers membrane-bound PD-L1 to lysosomes for targeted degradation. Furthermore, the efficiency of degradation is directly correlated with the PD-L1 expression level. NanoTACPD-L1 effectively leverages paclitaxel-induced PD-L1 upregulation to enhance PD-L1 degradation, employing a “Meet-Plot-With-Plot” strategy. In a series of in vivo models, NanoTACPD-L1 demonstrates superior therapeutic efficacy and immune activation, both when administered individually and in combination with paclitaxel, surpassing the effects of anti-PD-L1 antibody treatment. Collectively, our study provides a nanotechnology-based tool that can be enhanced by paclitaxel for PD-L1 degradation and validates its potential application in overcoming chemo-immunotherapy resistance.

Synthesis of Novel Ester-Based 5-Fluorouracil Derivatives

Fluorouracil (5-Fu, 1) is an antimetabolite cancer drug and the first-line drug of anticancer administration by WHO that has been widely used worldwide for more than 50 years. The development of 5-fluorouracil is an effort to obtain higher activity, decrease side effects, and create a specific target receptor compared to 5-fluorouracil. In this research, a series of novel 5-Fluorouracil (5-Fu) derivatives has been synthesized based on a benzoylation reaction (Schotten-Baumann reaction) of N1-hydroxylated 5-Fu called compound 2, 5-fluoro-1-(hydroxymethyl)-uracil. The benzoyl chloride substituents used in this research, including 3-chlorobenzoyl (4a), 2-chlorobenzoyl (4b), 3-nitrobenzoyl (4c), 4-methoxy benzoyl (4d), 4-trifluoromethylbenzoyl (4e), 3,4-dichlorobenzoyl (4f), and 4-nitrobenzoyl (4g) chloride become (4a-4f)-5Fu. This research meticulously examined the conditions (time and reaction temperature) at the second step of the synthesis reaction (esterification), ensuring the reliability of the results. The best synthesis conditions for 4a, 4b, 4c, 4d, and 4g compounds were found to be reflux at 40°C for 6 hours, whereas 4e and 4f compounds reactions were performed in an ice bath for 11 and 17 hours, respectively. All product syntheses, 4a-4g compound, were purified using column chromatography and eluted using eluent hexane: acetone (6:4), and the yields of 4a-4g compounds were around 61-79%. The pure compounds were characterized using FTIR and 1HNMR spectrometer, further validating the research. Based on these findings, it can be concluded that all 5-Fu derivatives can be synthesized using the Schotten-Baumann reaction method.

Computational assessment of the reactivity and anticancer activity of 1,2,3-triazole-thiazolidinones derivatives: An approach combining DFT calculations, molecular dynamics simulations, molecular docking, and ADMET

Cancer is a global health burden with escalating incidence and mortality rates, necessitating the exploration of novel therapeutic strategies. 1,2,3-Triazoles, recognized for their diverse biological activities, have emerged as attractive candidates in drug discovery targeting key proteins associated with various cancers. This study presents the synthesis of a library of 1,2,3-triazole hybrids incorporating thiazolidinone and isoxazoline moieties. The antitumor potential of these compounds was evaluated using both in-silico and in-vitro assays. Structure-activity relationship (SAR) analysis revealed that strategic substitution of the para position of the phenyl ring, particularly with a nitro (NO2) group, is promising to enhance cytotoxic activity. The binding potential of the synthesized compounds with the XIAP BIR2 domain, the specific receptor of caspase-3/7 activators, was explored through molecular docking. The stability of the protein-compound complexes procured from the docking was assessed through molecular dynamics (MD) simulation. The docking study demonstrated that the synthesized compounds had the potential to bind to the target protein. Among the compounds and their stereoisomers, compounds (R)-6d and (S)-6e exhibited a better binding potential to the protein. The MD simulation study revealed that the protein-(R)-6d complex was relatively stable.