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Highly aggressive, metastatic, neuroendocrine prostate cancer, which typically develops from prostate cancer cells acquiring resistance to androgen deprivation therapy, is associated with limited treatment options and hence poor prognosis. We have previously demonstrated that the αVβ3 integrin is over-expressed in neuroendocrine prostate cancer. We now show that LM609, a monoclonal antibody that specifically targets the human αVβ3 integrin, hinders the growth of neuroendocrine prostate cancer patient-derived xenografts in vivo. Our group has recently identified a novel αVβ3 integrin binding partner, NgR2, responsible for regulating the expression of neuroendocrine markers and for inducing neuroendocrine differentiation in prostate cancer cells. Through in vitro functional assays, we here demonstrate that NgR2 is crucial in promoting cell adhesion to αVβ3 ligands. Moreover, we describe for the first time co-fractionation of αVβ3 integrin and NgR2 in small extracellular vesicles derived from metastatic prostate cancer patients plasma. These prostate cancer patient-derived small extracellular vesicles have a functional impact on human monocytes, increasing their adhesion to fibronectin. The monocytes incubated with small extracellular vesicles do not show an associated change in conventional polarization marker expression and appear to be in an early stage that may be defined as adhesion competent. Overall, these findings allow us to better understand integrin-directed signaling and cell-cell communication during cancer progression. Furthermore, our results pave the way for new diagnostic and therapeutic perspectives for patients affected by neuroendocrine prostate cancer.

T cells undergo extensive chromatin remodeling over several days following stimulation through the T cell receptor. However, the kinetics and gene loci targeted by early remodeling events within the first 24 hours of T cell priming to orchestrate effector differentiation have not been well described. We identified that chromatin accessibility is rapidly and extensively remodeled within 1 hour of stimulation of naïve CD8+ T cells, leading to increased global chromatin accessibility at many effector T cell-associated genes that are enriched for AP-1, early growth response (EGR), and nuclear factor of activated T cells (NFAT) binding sites, but this short duration of stimulation is insufficient for commitment to clonal expansion in vivo. Sustained 24-hour stimulation led to further chromatin remodeling and was sufficient to enable clonal expansion. These data suggest that the duration of antigen receptor signaling is intimately coupled to chromatin remodeling and activation of genes involved in effector cell differentiation and highlight a potential mechanism that helps CD8+ T cells discriminate between foreign- and self-antigens.

We explore when and why large classes of proteins expand into new sequence space. We used an unsupervised machine learning approach to observe the sequence landscape of REC domains of bacterial response regulator proteins. We find that within-gene recombination can switch effector domains and, consequently, change the regulatory context of the duplicated protein.

Humans and mice with mutations in COL4A1 and COL4A2 manifest hallmarks of cerebral small vessel disease (cSVD). Mice with a missense mutation in Col4a1 at amino acid 1344 (Col4a1+/G1344D) exhibit age-dependent intracerebral hemorrhages (ICHs) and brain lesions. Here, we report that this pathology was associated with the loss of myogenic vasoconstriction, an intrinsic vascular response essential for the autoregulation of cerebral blood flow. Electrophysiological analyses showed that the loss of myogenic constriction resulted from blunted pressure-induced smooth muscle cell (SMC) membrane depolarization. Furthermore, we found that dysregulation of membrane potential was associated with impaired Ca2+-dependent activation of large-conductance Ca2+-activated K+ (BK) and transient receptor potential melastatin 4 (TRPM4) cation channels linked to disruptions in sarcoplasmic reticulum (SR) Ca2+ signaling. Col4a1 mutations impair protein folding, which can cause SR stress. Treating Col4a1+/G1344D mice with 4-phenylbutyrate, a compound that promotes the trafficking of misfolded proteins and alleviates SR stress, restored SR Ca2+ signaling, maintained BK and TRPM4 channel activity, prevented loss of myogenic tone, and reduced ICHs. We conclude that alterations in SR Ca2+ handling that impair ion channel activity result in dysregulation of SMC membrane potential and loss of myogenic tone and contribute to age-related cSVD in Col4a1+/G1344D mice.

Dysregulated Notch signaling is a common feature of cancer; however, its effects on tumor initiation and progression are highly variable, with Notch having either oncogenic or tumor-suppressive functions in various cancers. To better understand the mechanisms that regulate Notch function in cancer, we studied Notch signaling in a Drosophila tumor model, prostate cancer-derived cell lines, and tissue samples from patients with advanced prostate cancer. We demonstrated that increased activity of the Src-JNK pathway in tumors inactivated Notch signaling because of JNK pathway-mediated inhibition of the expression of the gene encoding the Notch S2 cleavage protease, Kuzbanian, which is critical for Notch activity. Consequently, inactive Notch accumulated in cells, where it was unable to transcribe genes encoding its target proteins, many of which have tumor-suppressive activities. These findings suggest that Src-JNK activity in tumors predicts Notch activity status and that suppressing Src-JNK signaling could restore Notch function in tumors, offering opportunities for diagnosis and targeted therapies for a subset of patients with advanced prostate cancer.

Craniofacial development is orchestrated by transcription factor-driven regulatory networks, epigenetic modifications, and signaling pathways. Signaling molecules and their receptors rely on endo-lysosomal trafficking to prevent accumulation on the plasma membrane. ESCRT (Endosomal Sorting Complexes Required for Transport) machinery is recruited to endosomal membranes enabling degradation of such endosomal cargoes. Studies in vitro and in invertebrate models established the requirements of the ESCRT machinery in membrane remodeling, endosomal trafficking, and lysosomal degradation of activated membrane receptors. However, investigations during vertebrate development have been scarce. By ENU-induced mutagenesis, we isolated a mouse line, Vps25ENU/ENU, carrying a hypomorphic allele of the ESCRT-II component Vps25, with craniofacial anomalies resembling features of human congenital syndromes. Here, we assessed the spatiotemporal dynamics of Vps25 and additional ESCRT-encoding genes during murine development. We show that these genes are ubiquitously expressed although enriched in discrete domains of the craniofacial complex, heart, and limbs. ESCRT-encoding genes, including Vps25, are expressed in both cranial neural crest-derived mesenchyme and epithelium. Unlike constitutive ESCRT mutants, Vps25ENU/ENU embryos display late lethality. They exhibit hypoplastic lower jaw, stunted snout, dysmorphic ear pinnae, and secondary palate clefting. Thus, we provide the first evidence for critical roles of ESCRT-II in craniofacial morphogenesis and report perturbation of NOTCH signaling in craniofacial domains of Vps25ENU/ENU embryos. Given the known roles of NOTCH signaling in the developing cranium, and notably the lower jaw, we propose that the NOTCH pathway partly mediates the craniofacial defects of Vps25ENU/ENU mouse embryos.

A number of therapeutic drugs have been developed from functional chemicals found in plants. Knowledge of plants used for medicinal purposes has historically been transmitted by word of mouth or through literature. The aim of the present study is to provide a systemic platform for the development of lead compounds against breast cancer based on a traditional medical text. To verify our systematic approach, integrating processes consisted of text mining of traditional medical texts, 3-D virtual docking screening, and in vitro and in vivo experimental validations were demonstrated. Our text analysis system identified rutin as a specific phytochemical traditionally used for cancer treatment. 3-D virtual screening predicted that rutin could block EGFR signaling. Thus, we validated significant anticancer effects of rutin against breast cancer cells through blockade of EGFR signaling pathway in vitro. We also demonstrated in vivo anti-cancer effects of rutin using the breast cancer recurrence in vivo models. In summary, our innovative approach might be proper for discovering new phytochemical lead compounds designing for blockade of malignant neoplasm including breast cancer. [BMB Reports 2023; 56(11): 594-599].

Identifying metabolic steps that are specifically required for the survival of cancer cells but are dispensable in normal cells remains a challenge1. Here we report a therapeutic vulnerability in a sugar nucleotide biosynthetic pathway that can be exploited in cancer cells with only a limited impact on normal cells. A systematic examination of conditionally essential metabolic enzymes revealed that UXS1, a Golgi enzyme that converts one sugar nucleotide (UDP-glucuronic acid, UDPGA) to another (UDP-xylose), is essential only in cells that express high levels of the enzyme immediately upstream of it, UGDH. This conditional relationship exists because UXS1 is required to prevent excess accumulation of UDPGA, which is produced by UGDH. UXS1 not only clears away UDPGA but also limits its production through negative feedback on UGDH. Excess UDPGA disrupts Golgi morphology and function, which impedes the trafficking of surface receptors such as EGFR to the plasma membrane and diminishes the signalling capacity of cells. UGDH expression is elevated in several cancers, including lung adenocarcinoma, and is further enhanced during chemoresistant selection. As a result, these cancer cells are selectively dependent on UXS1 for UDPGA detoxification, revealing a potential weakness in tumours with high levels of UGDH.

BACKGROUND: Autoimmune diseases are leading causes of ill health and morbidity and have diverse etiology. Two signaling pathways are key drivers of autoimmune pathology, interferon and nuclear factor-κB (NF-κB)/RelA, defining the 2 broad labels of interferonopathies and relopathies. Prior work has established that genetic loss of function of the NF-κB subunit RelB leads to autoimmune and inflammatory pathology in mice and humans. OBJECTIVE: We sought to characterize RelB-deficient autoimmunity by unbiased profiling of the responses of immune sentinel cells to stimulus and to determine the functional role of dysregulated gene programs in the RelB-deficient pathology. METHODS: Transcriptomic profiling was performed on fibroblasts and dendritic cells derived from patients with RelB deficiency and knockout mice, and transcriptomic responses and pathology were assessed in mice deficient in both RelB and the type I interferon receptor. RESULTS: We found that loss of RelB in patient-derived fibroblasts and mouse myeloid cells results in elevated induction of hundreds of interferon-stimulated genes. Removing hyperexpression of the interferon-stimulated gene program did not ameliorate the autoimmune pathology of RelB knockout mice. Instead, we found that RelB suppresses a different set of inflammatory response genes in a manner that is independent of interferon signaling but associated with NF-κB binding motifs. CONCLUSION: Although transcriptomic profiling would describe RelB-deficient autoimmune disease as an interferonopathy, the genetic evidence indicates that the pathology in mice is interferon-independent.

As cell signaling research has advanced, it has become clearer that signal transduction has complex spatiotemporal regulation that goes beyond foundational linear transduction models. Several technologies have enabled these discoveries, including fluorescent biosensors designed to report live biochemical signaling events. As genetically encoded and live-cell compatible tools, fluorescent biosensors are well suited to address diverse cell signaling questions across different spatial scales of regulation. In this review, methods of examining spatial signaling regulation and the design of fluorescent biosensors are introduced. Then, recent biosensor developments that illuminate the importance of spatial regulation in cell signaling are highlighted at several scales, including membranes and organelles, molecular assemblies, and cell/tissue heterogeneity. In closing, perspectives on how fluorescent biosensors will continue enhancing cell signaling research are discussed.

The enteric nervous system (ENS) is principally derived from vagal neural crest cells that migrate caudally along the entire length of the gastrointestinal tract, giving rise to neurons and glial cells in two ganglionated plexuses. Incomplete migration of enteric neural crest-derived cells (ENCDC) leads to Hirschsprung disease, a congenital disorder characterized by the absence of enteric ganglia along variable lengths of the colorectum. Our previous work strongly supported the essential role of the avian ceca, present at the junction of the midgut and hindgut, in hindgut ENS development, since ablation of the cecal buds led to incomplete ENCDC colonization of the hindgut. In situ hybridization shows bone morphogenetic protein-4 (BMP4) is highly expressed in the cecal mesenchyme, leading us to hypothesize that cecal BMP4 is required for hindgut ENS development. To test this, we modulated BMP4 activity using embryonic intestinal organ culture techniques and retroviral infection. We show that overexpression or inhibition of BMP4 in the ceca disrupts hindgut ENS development, with GDNF playing an important regulatory role. Our results suggest that these two important signaling pathways are required for normal ENCDC migration and enteric ganglion formation in the developing hindgut ENS.

Hematopoietic stem cells (HSCs) are tightly controlled to maintain a balance between blood cell production and self-renewal. While inflammation-related signaling is a critical regulator of HSC activity, the underlying mechanisms and the precise functions of specific factors under steady-state and stress conditions remain incompletely understood. We investigated the role of interferon regulatory factor 1 (IRF1), a transcription factor that is affected by multiple inflammatory stimuli, in HSC regulation. Our findings demonstrate that the loss of IRF1 from mouse HSCs significantly impairs self-renewal, increases stress-induced proliferation, and confers resistance to apoptosis. In addition, given the frequent abnormal expression of IRF1 in leukemia, we explored the potential of IRF1 expression level as a stratification marker for human acute myeloid leukemia. We show that IRF1-based stratification identifies distinct cancer-related signatures in patient subgroups. These findings establish IRF1 as a pivotal HSC controller and provide previously unknown insights into HSC regulation, with potential implications to IRF1 functions in the context of leukemia.

Many neurons in the central nervous system produce a single primary cilium that serves as a specialized signaling organelle. Several neuromodulatory G-protein-coupled receptors (GPCRs) localize to primary cilia in neurons, although it is not understood how GPCR signaling from the cilium impacts circuit function and behavior. We find that the vertebrate ancient long opsin A (VALopA), a Gi-coupled GPCR extraretinal opsin, targets to cilia of zebrafish spinal neurons. In the developing 1-d-old zebrafish, brief light activation of VALopA in neurons of the central pattern generator circuit for locomotion leads to sustained inhibition of coiling, the earliest form of locomotion. We find that a related extraretinal opsin, VALopB, is also Gi-coupled, but is not targeted to cilia. Light-induced activation of VALopB also suppresses coiling, but with faster kinetics. We identify the ciliary targeting domains of VALopA. Retargeting of both opsins shows that the locomotory response is prolonged and amplified when signaling occurs in the cilium. We propose that ciliary localization provides a mechanism for enhancing GPCR signaling in central neurons.

The molecular mechanisms and evolutionary changes accompanying synapse development are still poorly understood1,2. Here we generate a cross-species proteomic map of synapse development in the human, macaque and mouse neocortex. By tracking the changes of more than 1,000 postsynaptic density (PSD) proteins from midgestation to young adulthood, we find that PSD maturation in humans separates into three major phases that are dominated by distinct pathways. Cross-species comparisons reveal that human PSDs mature about two to three times slower than those of other species and contain higher levels of Rho guanine nucleotide exchange factors (RhoGEFs) in the perinatal period. Enhancement of RhoGEF signalling in human neurons delays morphological maturation of dendritic spines and functional maturation of synapses, potentially contributing to the neotenic traits of human brain development. In addition, PSD proteins can be divided into four modules that exert stage- and cell-type-specific functions, possibly explaining their differential associations with cognitive functions and diseases. Our proteomic map of synapse development provides a blueprint for studying the molecular basis and evolutionary changes of synapse maturation.

Human neutrophils respond to multiple chemoattractants to guide their migration from the vasculature to sites of infection and injury, where they clear pathogens and amplify inflammation. To properly focus their responses during this complex navigation, neutrophils prioritize pathogen- and injury-derived signals over long-range inflammatory signals, such as the leukotriene LTB4, secreted by host cells. Different chemoattractants can also drive qualitatively different modes of migration even though their receptors couple to the same Gαi family of G proteins. Here, we used live-cell imaging to demonstrate that the responses differed in their signaling dynamics. Low-priority chemoattractants caused transient responses, whereas responses to high-priority chemoattractants were sustained. We observed this difference in both primary neutrophils and differentiated HL-60 cells, for downstream signaling mediated by Ca2+, a major regulator of secretion, and Cdc42, a primary regulator of polarity and cell steering. The rapid attenuation of Cdc42 activation in response to LTB4 depended on the phosphorylation sites Thr308 and Ser310 in the carboxyl-terminal tail of its receptor LTB4R in a manner independent of endocytosis. Mutation of these residues to alanine impaired chemoattractant prioritization, although it did not affect chemoattractant-dependent differences in migration persistence. Our results indicate that distinct temporal regulation of shared signaling pathways distinguishes between receptors and contributes to chemoattractant prioritization.

Clostridioides difficile infection (CDI) is a major cause of healthcare-associated gastrointestinal infections1,2. The exaggerated colonic inflammation caused by C. difficile toxins such as toxin B (TcdB) damages tissues and promotes C. difficile colonization3-6, but how TcdB causes inflammation is unclear. Here we report that TcdB induces neurogenic inflammation by targeting gut-innervating afferent neurons and pericytes through receptors, including the Frizzled receptors (FZD1, FZD2 and FZD7) in neurons and chondroitin sulfate proteoglycan 4 (CSPG4) in pericytes. TcdB stimulates the secretion of the neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) from neurons and pro-inflammatory cytokines from pericytes. Targeted delivery of the TcdB enzymatic domain, through fusion with a detoxified diphtheria toxin, into peptidergic sensory neurons that express exogeneous diphtheria toxin receptor (an approach we term toxogenetics) is sufficient to induce neurogenic inflammation and recapitulates major colonic histopathology associated with CDI. Conversely, mice lacking SP, CGRP or the SP receptor (neurokinin 1 receptor) show reduced pathology in both models of caecal TcdB injection and CDI. Blocking SP or CGRP signalling reduces tissue damage and C. difficile burden in mice infected with a standard C. difficile strain or with hypervirulent strains expressing the TcdB2 variant. Thus, targeting neurogenic inflammation provides a host-oriented therapeutic approach for treating CDI.

Sunflowers are famous for their ability to track the sun throughout the day and then reorient at night to face east the following morning. This occurs by differential growth patterns, with the east sides of stems growing more during the day and the west sides of stems growing more at night. This process, termed heliotropism, is generally believed to be a specialized form of phototropism; however, the underlying mechanism is unknown. To better understand heliotropism, we compared gene expression patterns in plants undergoing phototropism in a controlled environment and in plants initiating and maintaining heliotropic growth in the field. We found the expected transcriptome signatures of phototropin-mediated phototropism in sunflower stems bending towards monochromatic blue light. Surprisingly, the expression patterns of these phototropism-regulated genes are quite different in heliotropic plants. Most genes rapidly induced during phototropism display only minor differences in expression across solar tracking stems. However, some genes that are both rapidly induced during phototropism and are implicated in growth responses to foliar shade are rapidly induced on the west sides of stems at the onset of heliotropism, suggesting a possible role for red light photoreceptors in solar tracking. To test the involvement of different photoreceptor signaling pathways in heliotropism, we modulated the light environment of plants initiating solar tracking. We found that depletion of either red and far-red light or blue light did not hinder the initiation or maintenance of heliotropism in the field. Together, our results suggest that the transcriptional regulation of heliotropism is distinct from phototropin-mediated phototropism and likely involves inputs from multiple light signaling pathways.

Traumatic brain injury (TBI) is major neurological burden globally, and effective treatments are urgently needed. TBI is characterized by a reduction in energy metabolism and synaptic function that seems a primary cause of neuronal dysfunction. R13, a small drug and BDNF mimetic showed promising results in improving spatial memory and anxiety-like behavior after TBI. Additionally, R13 was found to counteract reductions in molecules associated with BDNF signaling (p-TrkB, p-PI3K, p-AKT), synaptic plasticity (GluR2, PSD95, Synapsin I) as well as bioenergetic components such as mitophagy (SOD, PGC-1α, PINK1, Parkin, BNIP3, and LC3) and real-time mitochondrial respiratory capacity. Behavioral and molecular changes were accompanied by adaptations in functional connectivity assessed using MRI. Results highlight the potential of R13 as a therapeutic agent for TBI and provide valuable insights into the molecular and functional changes associated with this condition.

Abstract Background Drug-induced liver injury (DILI) is gradually becoming a common global problem that causes acute liver failure, especially in acute hepatic damage caused by acetaminophen (APAP). Paeoniflorin (PF) has a wide range of therapeutic effects to alleviate a variety of hepatic diseases. However, the relationship between them is still poorly investigated in current studies. Purpose This work aimed to explore the protective effects of PF on APAP-induced hepatic damage and researched the potential molecular mechanisms. Methods C57BL/6J male mice were injected with APAP to establish DILI model and were given PF for five consecutive days for treatment. Aiming to clarify the pharmacological effects, the molecular mechanisms of PF in APAP-induced DILI was elucidated by high-throughput and other techniques. Results The results demonstrated that serum levels of ALP, γ-GT, AST, TBIL, and ALT were decreased in APAP mice by the preventive effects of PF. Moreover, PF notably alleviated hepatic tissue inflammation and edema. Meanwhile, the results of TUNEL staining and related apoptotic factors coincided with the results of transcriptomics, suggesting that PF inhibited hepatocyte apoptosis by regulated MAPK signaling. Besides, PF also acted on reactive oxygen species (ROS) to regulate the oxidative stress for recovery the damaged mitochondria. More importantly, transmission electron microscopy showed the generation of autophagosomes after PF treatment, and PF was also downregulated mTOR and upregulated the expression of autophagy markers such as ATG5, ATG7, and BECN1 at the mRNA level and LC3, p62, ATG5, and ATG7 at the protein level, implying that the process by which PF exerted its effects was accompanied by the occurrence of autophagy. In addition, combinined with molecular dynamics simulations and western blotting of MAPK, the results suggested p38 as a direct target for PF on APAP. Specifically, PF-activated autophagy through the downregulation of MAPK/mTOR signaling, which in turn reduced APAP injury. Conclusions Paeoniflorin mitigated liver injury by activating autophagy to suppress oxidative stress and apoptosis via the MAPK/mTOR signaling pathway. Taken together, our findings elucidate the role and mechanism of paeoniflorin in DILI, which is expected to provide a new therapeutic strategy for the development of paeoniflorin. Graphical abstract

Abstract Mitochondria, responsible for cellular energy synthesis and signal transduction, intricately regulate diverse metabolic processes, mediating fundamental biological phenomena such as cell growth, aging, and apoptosis. Tumor invasion and metastasis, key characteristics of malignancies, significantly impact patient prognosis. Tumor cells frequently exhibit metabolic abnormalities in mitochondria, including alterations in metabolic dynamics and changes in the expression of relevant metabolic genes and associated signal transduction pathways. Recent investigations unveil further insights into mitochondrial metabolic abnormalities, revealing their active involvement in tumor cell proliferation, resistance to chemotherapy, and a crucial role in tumor cell invasion and metastasis. This paper comprehensively outlines the latest research advancements in mitochondrial structure and metabolic function. Emphasis is placed on summarizing the role of mitochondrial metabolic abnormalities in tumor invasion and metastasis, including alterations in the mitochondrial genome (mutations), activation of mitochondrial-to-nuclear signaling, and dynamics within the mitochondria, all intricately linked to the processes of tumor invasion and metastasis. In conclusion, the paper discusses unresolved scientific questions in this field, aiming to provide a theoretical foundation and novel perspectives for developing innovative strategies targeting tumor invasion and metastasis based on mitochondrial biology. Graphical Abstract

Abstract Background p63 is a transcription factor with intrinsic pioneer factor activity and pleiotropic functions. Transforming growth factor β (TGFβ) signaling via activation and cooperative action of canonical, SMAD, and non-canonical, MAP-kinase (MAPK) pathways, elicits both anti- and pro-tumorigenic properties, including cell stemness and invasiveness. TGFβ activates the ΔNp63 transcriptional program in cancer cells; however, the link between TGFβ and p63 in unmasking the epigenetic landscape during tumor progression allowing chromatin accessibility and gene transcription, is not yet reported. Methods Small molecule inhibitors, including protein kinase inhibitors and RNA-silencing, provided loss of function analyses. Sphere formation assays in cancer cells, chromatin immunoprecipitation and mRNA expression assays were utilized in order to gain mechanistic evidence. Mass spectrometry analysis coupled to co-immunoprecipitation assays revealed novel p63 interactors and their involvement in p63-dependent transcription. Results The sphere-forming capacity of breast cancer cells was enhanced upon TGFβ stimulation and significantly decreased upon ΔNp63 depletion. Activation of TGFβ signaling via p38 MAPK signaling induced ΔNp63 phosphorylation at Ser 66/68 resulting in stabilized ΔNp63 protein with enhanced DNA binding properties. TGFβ stimulation altered the ratio of H3K27ac and H3K27me3 histone modification marks, pointing towards higher H3K27ac and increased p300 acetyltransferase recruitment to chromatin. By silencing the expression of ΔNp63, the TGFβ effect on chromatin remodeling was abrogated. Inhibition of H3K27me3, revealed the important role of TGFβ as the upstream signal for guiding ΔNp63 to the TGFβ/SMAD gene loci, as well as the indispensable role of ΔNp63 in recruiting histone modifying enzymes, such as p300, to these genomic regions, regulating chromatin accessibility and gene transcription. Mechanistically, TGFβ through SMAD activation induced dissociation of ΔNp63 from NURD or NCOR/SMRT histone deacetylation complexes, while promoted the assembly of ΔNp63-p300 complexes, affecting the levels of histone acetylation and the outcome of ΔNp63-dependent transcription. Conclusions ΔNp63, phosphorylated and recruited by TGFβ to the TGFβ/SMAD/ΔNp63 gene loci, promotes chromatin accessibility and transcription of target genes related to stemness and cell invasion.

Protein tyrosine phosphorylation is a post-translational modification that regulates protein structure to modulate demic organisms’ homeostasis and function. This physiological process is regulated by two enzyme families, protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). As an important regulator of protein function, PTPs are indispensable for maintaining cell intrinsic physiology in different systems, as well as liver physiological and pathological processes. Dysregulation of PTPs has been implicated in multiple liver-related diseases, including chronic liver diseases (CLDs), hepatocellular carcinoma (HCC), and liver injury, and several PTPs are being studied as drug therapeutic targets. Therefore, given the regulatory role of PTPs in diverse liver diseases, a collated review of their function and mechanism is necessary. Moreover, based on the current research status of targeted therapy, we emphasize the inclusion of several PTP members that are clinically significant in the development and progression of liver diseases. As an emerging breakthrough direction in the treatment of liver diseases, this review summarizes the research status of PTP-targeting compounds in liver diseases to illustrate their potential in clinical treatment. Overall, this review aims to support the development of novel PTP-based treatment pathways for liver diseases.

Abstract Melatonin is a multifunctional molecule with diverse biological roles that holds great value as a health-promoting bioactive molecule in any food product and yeast’s ability to produce it has been extensively demonstrated in the last decade. However, its quantification presents costly analytical challenges due to the usual low concentrations found as the result of yeast metabolism. This study addresses these analytical challenges by optimizing a yeast biosensor based on G protein-coupled receptors (GPCR) for melatonin detection and quantitation. Strategic genetic modifications were employed to significantly enhance its sensitivity and fluorescent signal output, making it suitable for detection of yeast-produced melatonin. The optimized biosensor demonstrated significantly improved sensitivity and fluorescence, enabling the screening of 101 yeast strains and the detection of melatonin in various wine samples. This biosensor’s efficacy in quantifying melatonin in yeast growth media underscores its utility in exploring melatonin production dynamics and potential applications in functional food development. This study provides a new analytical approach that allows a rapid and cost-effective melatonin analysis to reach deeper insights into the bioactivity of melatonin in fermented products and its implications for human health. These findings highlight the broader potential of biosensor technology in streamlining analytical processes in fermentation science.

Abstract The growth, yield, and seed quality of rapeseed are negatively affected by drought stress. Therefore, it is of great value to understand the molecular mechanism behind this phenomenon. In a previous study, long non-coding RNAs (lncRNAs) were found to play a key role in the response of rapeseed seedlings to drought stress. However, many questions remained unanswered. This study was the first to investigate the expression profile of lncRNAs not only under control and drought treatment, but also under the rehydration treatment. A total of 381 differentially expressed lncRNA and 10,253 differentially expressed mRNAs were identified in the comparison between drought stress and control condition. In the transition from drought stress to rehydration, 477 differentially expressed lncRNAs and 12,543 differentially expressed mRNAs were detected. After identifying the differentially expressed (DE) lncRNAs, the comprehensive lncRNAs-engaged network with the co-expressed mRNAs in leaves under control, drought and rehydration was investigated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of co-expressed mRNAs identified the most significant pathways related with plant hormones (expecially abscisic acid, auxin, cytokinins, and gibberellins) in the signal transduction. The genes, co-expressed with the most-enriched DE-lncRNAs, were considered as the most effective candidates in the water-loss and water-recovery processes, including protein phosphatase 2 C (PP2C), ABRE-binding factors (ABFs), and SMALL AUXIN UP-REGULATED RNAs (SAURs). In summary, these analyses clearly demonstrated that DE-lncRNAs can act as a regulatory hub in plant-water interaction by controlling phytohormone signaling pathways and provided an alternative way to explore the complex mechanisms of drought tolerance in rapeseed.

Human astrovirus is a positive-sense, single-stranded RNA virus. Astrovirus infection causes gastrointestinal symptoms and can lead to encephalitis in immunocompromised patients. Positive-strand RNA viruses typically utilize host intracellular membranes to form replication organelles, which are potential antiviral targets. Many of these replication organelles are double-membrane vesicles (DMVs). Here, we show that astrovirus infection leads to an increase in DMV formation through a replication-dependent mechanism that requires some early components of the autophagy machinery. Results indicate that the upstream class III phosphatidylinositol 3-kinase (PI3K) complex, but not LC3 conjugation machinery, is utilized in DMV formation. Both chemical and genetic inhibition of the PI3K complex lead to significant reduction in DMVs, as well as viral replication. Elucidating the role of autophagy machinery in DMV formation during astrovirus infection reveals a potential target for therapeutic intervention for immunocompromised patients. IMPORTANCE These studies provide critical new evidence that astrovirus replication requires formation of double-membrane vesicles, which utilize class III phosphatidylinositol 3-kinase (PI3K), but not LC3 conjugation autophagy machinery, for biogenesis. These results are consistent with replication mechanisms for other positive-sense RNA viruses suggesting that targeting PI3K could be a promising therapeutic option for not only astrovirus, but other positive-sense RNA virus infections.

Loss of cognitive function with age is devastating. EGL-30/GNAQ and Gαq signaling pathways are highly conserved between C. elegans and mammals, and murine Gnaq is enriched in hippocampal neurons and declines with age. We found that activation of EGL-30 in aged worms triples memory span, and GNAQ gain of function significantly improved memory in aged mice: GNAQ(gf) in hippocampal neurons of 24-month-old mice (equivalent to 70- to 80-year-old humans) rescued age-related impairments in well-being and memory. Single-nucleus RNA sequencing revealed increased expression of genes regulating synaptic function, axon guidance, and memory in GNAQ-treated mice, and worm orthologs of these genes were required for long-term memory extension in worms. These experiments demonstrate that C. elegans is a powerful model to identify mammalian regulators of memory, leading to the identification of a pathway that improves memory in extremely old mice. To our knowledge, this is the oldest age at which an intervention has improved age-related cognitive decline.

The Maillard reaction, a chemical reaction between amino acids and sugars, is exploited to produce flavorful food ubiquitously, from the baking industry to our everyday lives. However, the Maillard reaction also occurs in all cells, from prokaryotes to eukaryotes, forming advanced glycation end-products (AGEs). AGEs are a heterogeneous group of compounds resulting from the irreversible reaction between biomolecules and α-dicarbonyls (α-DCs), including methylglyoxal (MGO), an unavoidable byproduct of anaerobic glycolysis and lipid peroxidation. We previously demonstrated that Caenorhabditis elegans mutants lacking the glod-4 glyoxalase enzyme displayed enhanced accumulation of α-DCs, reduced lifespan, increased neuronal damage, and touch hypersensitivity. Here, we demonstrate that glod-4 mutation increased food intake and identify that MGO-derived hydroimidazolone, MG-H1, is a mediator of the observed increase in food intake. RNAseq analysis in glod-4 knockdown worms identified upregulation of several neurotransmitters and feeding genes. Suppressor screening of the overfeeding phenotype identified the tdc-1-tyramine-tyra-2/ser-2 signaling as an essential pathway mediating AGE (MG-H1)-induced feeding in glod-4 mutants. We also identified the elt-3 GATA transcription factor as an essential upstream regulator for increased feeding upon accumulation of AGEs by partially controlling the expression of tdc-1 gene. Furthermore, the lack of either tdc-1 or tyra-2/ser-2 receptors suppresses the reduced lifespan and rescues neuronal damage observed in glod-4 mutants. Thus, in C. elegans, we identified an elt-3 regulated tyramine-dependent pathway mediating the toxic effects of MG-H1 AGE. Understanding this signaling pathway may help understand hedonistic overfeeding behavior observed due to modern AGE-rich diets.

Protein-membrane interactions (PMIs) are ubiquitous in cellular signaling. Initial steps of signal transduction cascades often rely on transient and dynamic interactions with the inner plasma membrane leaflet to populate and regulate signaling hotspots. Methods to target and modulate these interactions could yield attractive tool compounds and drug candidates. Here, we demonstrate that the conjugation of a medium-chain lipid tail to the covalent K-Ras(G12C) binder MRTX849 at a solvent-exposed site enables such direct modulation of PMIs. The conjugated lipid tail interacts with the tethered membrane and changes the relative membrane orientation and conformation of K-Ras(G12C), as shown by molecular dynamics (MD) simulation-supported NMR studies. In cells, this PMI modulation restricts the lateral mobility of K-Ras(G12C) and disrupts nanoclusters. The described strategy could be broadly applicable to selectively modulate transient PMIs.

The TGF-β regulatory system plays crucial roles in the preservation of organismal integrity. TGF-β signaling controls metazoan embryo development, tissue homeostasis, and injury repair through coordinated effects on cell proliferation, phenotypic plasticity, migration, metabolic adaptation, and immune surveillance of multiple cell types in shared ecosystems. Defects of TGF-β signaling, particularly in epithelial cells, tissue fibroblasts, and immune cells, disrupt immune tolerance, promote inflammation, underlie the pathogenesis of fibrosis and cancer, and contribute to the resistance of these diseases to treatment. Here, we review how TGF-β coordinates multicellular response programs in health and disease and how this knowledge can be leveraged to develop treatments for diseases of the TGF-β system.

The interleukin-4 (IL-4) cytokine plays a critical role in modulating immune homeostasis. Although there is great interest in harnessing this cytokine as a therapeutic in natural or engineered formats, the clinical potential of native IL-4 is limited by its instability and pleiotropic actions. Here, we design IL-4 cytokine mimetics (denoted Neo-4) based on a de novo engineered IL-2 mimetic scaffold and demonstrate that these cytokines can recapitulate physiological functions of IL-4 in cellular and animal models. In contrast with natural IL-4, Neo-4 is hyperstable and signals exclusively through the type I IL-4 receptor complex, providing previously inaccessible insights into differential IL-4 signaling through type I versus type II receptors. Because of their hyperstability, our computationally designed mimetics can directly incorporate into sophisticated biomaterials that require heat processing, such as three-dimensional-printed scaffolds. Neo-4 should be broadly useful for interrogating IL-4 biology, and the design workflow will inform targeted cytokine therapeutic development.

DNA damage is a central contributor to the aging process. In the brain, a major threat to the DNA is the considerable amount of reactive oxygen species produced, which can inflict oxidative DNA damage. This type of damage is removed by the base excision repair (BER) pathway, an essential DNA repair mechanism, which contributes to genome stability in the brain. Despite the crucial role of the BER pathway, insights into how this pathway is affected by aging in the human brain and the underlying regulatory mechanisms are very limited. By microarray analysis of four cortical brain regions from humans aged 20-99 years (n = 57), we show that the expression of core BER genes is largely downregulated during aging across brain regions. Moreover, we find that expression of many BER genes correlates positively with the expression of the neurotrophin brain-derived neurotrophic factor (BDNF) in the human brain. In line with this, we identify binding sites for the BDNF-activated transcription factor, cyclic-AMP response element-binding protein (CREB), in the promoter of most BER genes and confirm the ability of BDNF to regulate several BER genes by BDNF treatment of mouse primary hippocampal neurons. Together, these findings uncover the transcriptional landscape of BER genes during aging of the brain and suggest BDNF as an important regulator of BER in the human brain.

The PI3K/AKT/mTOR (PAM) signaling pathway is a highly conserved signal transduction network in eukaryotic cells that promotes cell survival, cell growth, and cell cycle progression. Growth factor signalling to transcription factors in the PAM axis is highly regulated by multiple cross-interactions with several other signaling pathways, and dysregulation of signal transduction can predispose to cancer development. The PAM axis is the most frequently activated signaling pathway in human cancer and is often implicated in resistance to anticancer therapies. Dysfunction of components of this pathway such as hyperactivity of PI3K, loss of function of PTEN, and gain-of-function of AKT, are notorious drivers of treatment resistance and disease progression in cancer. In this review we highlight the major dysregulations in the PAM signaling pathway in cancer, and discuss the results of PI3K, AKT and mTOR inhibitors as monotherapy and in co-administation with other antineoplastic agents in clinical trials as a strategy for overcoming treatment resistance. Finally, the major mechanisms of resistance to PAM signaling targeted therapies, including PAM signaling in immunology and immunotherapies are also discussed.

PURPOSE: Stimulator of interferon genes (STING) agonists are currently in development for treatment of solid tumors, including pancreatic ductal adenocarcinoma (PDAC). Response rates to STING agonists alone have been promising yet modest, and combination therapies will likely be required to elicit their full potency. We sought to identify combination therapies and mechanisms that augment the tumor cell-intrinsic effect of therapeutically relevant STING agonists apart from their known effects on tumor immunity. EXPERIMENTAL DESIGN: We screened 430 kinase inhibitors to identify synergistic effectors of tumor cell death with diABZI, an intravenously administered and systemically available STING agonist. We deciphered the mechanisms of synergy with STING agonism that cause tumor cell death in vitro and tumor regression in vivo. RESULTS: We found that MEK inhibitors caused the greatest synergy with diABZI and that this effect was most pronounced in cells with high STING expression. MEK inhibition enhanced the ability of STING agonism to induce type I IFN-dependent cell death in vitro and tumor regression in vivo. We parsed NFκB-dependent and NFκB-independent mechanisms that mediate STING-driven type I IFN production and show that MEK signaling inhibits this effect by suppressing NFκB activation. CONCLUSIONS: Our results highlight the cytotoxic effects of STING agonism on PDAC cells that are independent of tumor immunity and that these therapeutic benefits of STING agonism can be synergistically enhanced by MEK inhibition.

The borders between cell and developmental biology, which have always been permeable, have largely dissolved. One manifestation is the blossoming of cilia biology, with cell and developmental approaches (increasingly complemented by human genetics, structural insights, and computational analysis) fruitfully advancing understanding of this fascinating, multifunctional organelle. The last eukaryotic common ancestor probably possessed a motile cilium, providing evolution with ample opportunity to adapt cilia to many jobs. Over the last decades, we have learned how non-motile, primary cilia play important roles in intercellular communication. Reflecting their diverse motility and signaling functions, compromised cilia cause a diverse range of diseases collectively called ciliopathies. In this review, we highlight how cilia signal, focusing on how second messengers generated in cilia convey distinct information; how cilia are a potential source of signals to other cells; how evolution may have shaped ciliary function; and how cilia research may address thorny outstanding questions.

Plants are in contact with diverse pathogens and microorganisms. Intense investigation over the last 30 years has resulted in the identification of multiple immune receptors in model and crop species as well as signaling overlap in surface-localized and intracellular immune receptors. However, scientists still have a limited understanding of how plants respond to diverse pathogens with spatial and cellular resolution. Recent advancements in single-cell, single-nucleus and spatial technologies can now be applied to plant-pathogen interactions. Here, we outline the current state of these technologies and highlight outstanding biological questions that can be addressed in the future.

The mechanisms of cognitive decline after intraventricular hemorrhage (IVH) in some patients continue to be poorly understood. Multiple rodent models of intraventricular or subarachnoid hemorrhage have only shown mild or even no cognitive impairment on subsequent behavioral testing. In this study, we show that intraventricular hemorrhage only leads to a significant spatial memory deficit in the Morris water maze if it occurs in the setting of an elevated intracranial pressure (ICP). Histopathological analysis of these IVH + ICP animals did not show evidence of neuronal degeneration in the hippocampal formation after 2 weeks but instead showed significant microglial activation measured by lacunarity and fractal dimensions. RNA sequencing of the hippocampus showed distinct enrichment of genes in the IVH + ICP group but not in IVH alone having activated microglial signaling pathways. The most significantly activated signaling pathway was the classical complement pathway, which is used by microglia to remove synapses, followed by activation of the Fc receptor and DAP12 pathways. Thus, our study lays the groundwork for identifying signaling pathways that could be targeted to ameliorate behavioral deficits after IVH.

Cutaneous neurofibromas (cNFs) are the most common tumor in people with the rasopathy neurofibromatosis type 1. They number in hundreds or even thousands throughout the body, and currently, there are no effective interventions to prevent or treat these skin tumors. To facilitate the identification of novel and effective therapies, essential studies including a more refined understanding of cNF biology and the role of RAS signaling and downstream effector pathways responsible for cNF initiation, growth, and maintenance are needed. This review highlights the current state of knowledge of RAS signaling in cNF pathogenesis and therapeutic development for cNF treatment.

Immune checkpoint blockade (ICB) targeting PD-1 and CTLA-4 has revolutionized cancer treatment. However, many cancers do not respond to ICB, prompting the search for additional strategies to achieve durable responses. G-protein-coupled receptors (GPCRs) are the most intensively studied drug targets but are underexplored in immuno-oncology. Here, we cross-integrated large singe-cell RNA-sequencing datasets from CD8+ T cells covering 19 distinct cancer types and identified an enrichment of Gαs-coupled GPCRs on exhausted CD8+ T cells. These include EP2, EP4, A2AR, β1AR and β2AR, all of which promote T cell dysfunction. We also developed transgenic mice expressing a chemogenetic CD8-restricted Gαs-DREADD to activate CD8-restricted Gαs signaling and show that a Gαs-PKA signaling axis promotes CD8+ T cell dysfunction and immunotherapy failure. These data indicate that Gαs-GPCRs are druggable immune checkpoints that might be targeted to enhance the response to ICB immunotherapies.

Sexual reproduction is prevalent in eukaryotic organisms and plays a critical role in the evolution of new traits and in the generation of genetic diversity. Environmental factors often have a direct impact on the occurrence and frequency of sexual reproduction in fungi. The regulatory effects of atmospheric relative humidity (RH) on sexual reproduction and pathogenesis in plant fungal pathogens and in soil fungi have been extensively investigated. However, the knowledge of how RH regulates the lifecycles of human fungal pathogens is limited. In this study, we report that low atmospheric RH promotes the development of mating projections and same-sex (homothallic) mating in the human fungal pathogen Candida albicans. Low RH causes water loss in C. albicans cells, which results in osmotic stress and the generation of intracellular reactive oxygen species (ROS) and trehalose. The water transporting aquaporin Aqy1, and the G-protein coupled receptor Gpr1 function as cell surface sensors of changes in atmospheric humidity. Perturbation of the trehalose metabolic pathway by inactivating trehalose synthase or trehalase promotes same-sex mating in C. albicans by increasing osmotic or ROS stresses, respectively. Intracellular trehalose and ROS signal the Hog1-osmotic and Hsf1-Hsp90 signaling pathways to regulate the mating response. We, therefore, propose that the cell surface sensors Aqy1 and Gpr1, intracellular trehalose and ROS, and the Hog1-osmotic and Hsf1-Hsp90 signaling pathways function coordinately to regulate sexual mating in response to low atmospheric RH conditions in C. albicans.

Canonical interleukin-2 (IL-2) signaling via the high-affinity CD25-containing IL-2 receptor-Janus kinase (JAK)1,3-signal transducer and activator of transcription 5 (STAT5) pathway is essential for development and maintenance of CD4+CD25HiFoxp3+ regulatory T cells (Tregs) that support immune homeostasis. Here, we report that IL-2 signaling via an alternative CD25-chemokine receptor pathway promotes the suppressive function of Tregs. Using an antibody against CD25 that biases IL-2 signaling toward this alternative pathway, we establish that this pathway increases the suppressive activity of Tregs and ameliorates murine experimental autoimmune encephalomyelitis (EAE). Furthermore, heparan sulfate, an IL-2-binding element of cell surfaces and extracellular matrix, or an engineered IL-2 immunocytokine can also direct IL-2 signaling toward this alternative pathway. Overall, these data reveal a non-canonical mechanism for IL-2 signaling that promotes suppressive functions of Tregs, further elucidates how IL-2 supports immune homeostasis, and suggests approaches to promote or suppress Treg functions.

The JAK/STAT signaling pathway plays a key role in cytokine signaling and is involved in development, immunity, and tumorigenesis for nearly any cell. At first glance, the JAK/STAT signaling pathway appears to be straightforward. However, on closer examination, the factors influencing the JAK/STAT signaling activity, such as cytokine diversity, receptor profile, overlapping JAK and STAT specificity among non-redundant functions of the JAK/STAT complexes, positive regulators (e.g., cooperating transcription factors), and negative regulators (e.g., SOCS, PIAS, PTP), demonstrate the complexity of the pathways architecture, which can be quickly disturbed by mutations. The JAK/STAT signaling pathway has been, and still is, subject of basic research and offers an enormous potential for the development of new methods of personalized medicine and thus the translation of basic molecular research into clinical practice beyond the use of JAK inhibitors. Gain-of-function and loss-of-function mutations in the three immunologically particularly relevant signal transducers STAT1, STAT3, and STAT6 as well as JAK1 and JAK3 present themselves through individual phenotypic clinical pictures. The established, traditional paradigm of loss-of-function mutations leading to immunodeficiency and gain-of-function mutation leading to autoimmunity breaks down and a more differentiated picture of disease patterns evolve. This review is intended to provide an overview of these specific syndromes from a clinical perspective and to summarize current findings on pathomechanism, symptoms, immunological features, and therapeutic options of STAT1, STAT3, STAT6, JAK1, and JAK3 loss-of-function and gain-of-function diseases.

The α-arrestin ARRDC3 is a recently discovered tumor suppressor in invasive breast cancer that functions as a multifaceted adaptor protein to control protein trafficking and cellular signaling. However, the molecular mechanisms that control ARRDC3 function are unknown. Other arrestins are known to be regulated by posttranslational modifications, suggesting that ARRDC3 may be subject to similar regulatory mechanisms. Here we report that ubiquitination is a key regulator of ARRDC3 function and is mediated primarily by two proline-rich PPXY motifs in the ARRDC3 C-tail domain. Ubiquitination and the PPXY motifs are essential for ARRDC3 function in regulating GPCR trafficking and signaling. Additionally, ubiquitination and the PPXY motifs mediate ARRDC3 protein degradation, dictate ARRDC3 subcellular localization, and are required for interaction with the NEDD4-family E3 ubiquitin ligase WWP2. These studies demonstrate a role for ubiquitination in regulating ARRDC3 function and reveal a mechanism by which ARRDC3 divergent functions are controlled.

mTORC1 is the key rheostat controlling the cellular metabolic state. Of the various inputs to mTORC1, the most potent effector of intracellular nutrient status is amino acid supply. Despite an established role for MAP4K3 in promoting mTORC1 activation in the presence of amino acids, the signaling pathway by which MAP4K3 controls mTORC1 activation remains unknown. Here, we examined the process of MAP4K3 regulation of mTORC1 and found that MAP4K3 represses the LKB1-AMPK pathway to achieve robust mTORC1 activation. When we sought the regulatory link between MAP4K3 and LKB1 inhibition, we discovered that MAP4K3 physically interacts with the master nutrient regulatory factor sirtuin-1 (SIRT1) and phosphorylates SIRT1 to repress LKB1 activation. Our results reveal the existence of a novel signaling pathway linking amino acid satiety with MAP4K3-dependent suppression of SIRT1 to inactivate the repressive LKB1-AMPK pathway and thereby potently activate the mTORC1 complex to dictate the metabolic disposition of the cell.

Widespread release of norepinephrine (NE) throughout the forebrain fosters learning and memory via adrenergic receptor (AR) signaling, but the molecular mechanisms are largely unknown. The β2 AR and its downstream effectors, the trimeric stimulatory Gs-protein, adenylyl cyclase (AC), and the cAMP-dependent protein kinase A (PKA), form a unique signaling complex with the L-type Ca2+ channel (LTCC) CaV1.2. Phosphorylation of CaV1.2 by PKA on Ser1928 is required for the upregulation of Ca2+ influx on β2 AR stimulation and long-term potentiation induced by prolonged theta-tetanus (PTT-LTP) but not LTP induced by two 1-s-long 100-Hz tetani. However, the function of Ser1928 phosphorylation in vivo is unknown. Here, we show that S1928A knock-in (KI) mice of both sexes, which lack PTT-LTP, express deficiencies during initial consolidation of spatial memory. Especially striking is the effect of this mutation on cognitive flexibility as tested by reversal learning. Mechanistically, long-term depression (LTD) has been implicated in reversal learning. It is abrogated in male and female S1928A knock-in mice and by β2 AR antagonists and peptides that displace β2 AR from CaV1.2. This work identifies CaV1.2 as a critical molecular locus that regulates synaptic plasticity, spatial memory and its reversal, and LTD.SIGNIFICANCE STATEMENT We show that phosphorylation of the Ca2+ channel CaV1.2 on Ser1928 is important for consolidation of spatial memory and especially its reversal, and long-term depression (LTD). Identification of Ser1928 as critical for LTD and reversal learning supports the model that LTD underlies flexibility of reference memory.

Root-knot nematodes (Meloidogyne spp.) are highly evolved obligate parasites threatening global food security. These parasites have a remarkable ability to establish elaborate feeding sites in roots, which are their only source of nutrients throughout their life cycle. A wide range of nematode effectors have been implicated in modulation of host pathways for defense suppression and/or feeding site development. Plants produce a diverse array of peptide hormones including PLANT PEPTIDE CONTAINING SULFATED TYROSINE (PSY)-family peptides, which promote root growth via cell expansion and proliferation. A sulfated PSY-like peptide RaxX (required for activation of XA21 mediated immunity X) produced by the biotrophic bacterial pathogen (Xanthomonas oryzae pv. oryzae) has been previously shown to contribute to bacterial virulence. Here, we report the identification of genes from root-knot nematodes predicted to encode PSY-like peptides (MigPSYs) with high sequence similarity to both bacterial RaxX and plant PSYs. Synthetic sulfated peptides corresponding to predicted MigPSYs stimulate root growth in Arabidopsis. MigPSY transcript levels are highest early in the infection cycle. Downregulation of MigPSY gene expression reduces root galling and egg production, suggesting that the MigPSYs serve as nematode virulence factors. Together, these results indicate that nematodes and bacteria exploit similar sulfated peptides to hijack plant developmental signaling pathways to facilitate parasitism.

RIT1 is a RAS guanosine triphosphatase (GTPase) that regulates different aspects of signal transduction and is mutated in lung cancer, leukemia, and in the germline of individuals with Noonan syndrome. Pathogenic RIT1 proteins promote mitogen-activated protein kinase (MAPK) hyperactivation; however, this mechanism remains poorly understood. Here, we show that RAF kinases are direct effectors of membrane-bound mutant RIT1 necessary for MAPK activation. We identify critical residues in RIT1 that facilitate interaction with membrane lipids and show that these are necessary for association with RAF kinases and MAPK activation. Although mutant RIT1 binds to RAF kinases directly, it fails to activate MAPK signaling in the absence of classical RAS proteins. Consistent with aberrant RAF/MAPK activation as a driver of disease, we show that pathway inhibition alleviates cardiac hypertrophy in a mouse model of RIT1 mutant Noonan syndrome. These data shed light on the function of pathogenic RIT1 and identify avenues for therapeutic intervention.

Endothelial-to-mesenchymal transition (EndMT), a process initiated by activation of endothelial TGF-β signaling, underlies numerous chronic vascular diseases and fibrotic states. Once induced, EndMT leads to a further increase in TGF-β signaling, thus establishing a positive-feedback loop with EndMT leading to more EndMT. Although EndMT is understood at the cellular level, the molecular basis of TGF-β-driven EndMT induction and persistence remains largely unknown. Here, we show that metabolic modulation of the endothelium, triggered by atypical production of acetate from glucose, underlies TGF-β-driven EndMT. Induction of EndMT suppresses the expression of the enzyme PDK4, which leads to an increase in ACSS2-dependent Ac-CoA synthesis from pyruvate-derived acetate. This increased Ac-CoA production results in acetylation of the TGF-β receptor ALK5 and SMADs 2 and 4 leading to activation and long-term stabilization of TGF-β signaling. Our results establish the metabolic basis of EndMT persistence and unveil novel targets, such as ACSS2, for the potential treatment of chronic vascular diseases.

Tumor necrosis factor (TNF) is a key inflammatory cytokine that warns recipient cells of a nearby infection or tissue damage. Acute exposure to TNF activates characteristic oscillatory dynamics of the transcription factor NFκB and induces a characteristic gene expression program; these are distinct from the responses of cells directly exposed to pathogen-associated molecular patterns (PAMPs). Here, we report that tonic TNF exposure is critical for safeguarding TNF's specific functions. In the absence of tonic TNF conditioning, acute exposure to TNF causes (i) NFκB signaling dynamics that are less oscillatory and more like PAMP-responsive NFκB dynamics, (ii) immune gene expression that is more similar to the Pam3CSK4 response program, and (iii) broader epigenomic reprogramming that is characteristic of PAMP-responsive changes. We show that the absence of tonic TNF signaling effects subtle changes to TNF receptor availability and dynamics such that enhanced pathway activity results in non-oscillatory NFκB. Our results reveal tonic TNF as a key tissue determinant of the specific cellular responses to acute paracrine TNF exposure, and their distinction from responses to direct exposure to PAMPs.

"γc" cytokines are a family whose receptors share a "common-gamma-chain" signaling moiety, and play central roles in differentiation, homeostasis, and communications of all immunocyte lineages. As a resource to better understand their range and specificity of action, we profiled by RNAseq the immediate-early responses to the main γc cytokines across all immunocyte lineages. The results reveal an unprecedented landscape: broader, with extensive overlap between cytokines (one cytokine doing in one cell what another does elsewhere) and essentially no effects unique to any one cytokine. Responses include a major downregulation component and a broad Myc-controlled resetting of biosynthetic and metabolic pathways. Various mechanisms appear involved: fast transcriptional activation, chromatin remodeling, and mRNA destabilization. Other surprises were uncovered: IL2 effects in mast cells, shifts between follicular and marginal zone B cells, paradoxical and cell-specific cross-talk between interferon and γc signatures, or an NKT-like program induced by IL21 in CD8+ T cells.

Tissue-resident macrophages are heterogeneous and perform location-dependent functions. Skin resident macrophages play intriguing roles in long-distance intercellular signaling by mediating cellular protrusions called airinemes in zebrafish. These macrophages relay signaling molecules containing airineme vesicles between pigment cells, and their absence disrupts airineme-mediated signaling and pigment pattern formation. It is unknown if the same macrophages control both these signaling and typical immune functions or if a separate subpopulation functions in intercellular communication. With high-resolution imaging and genetic ablation approaches, we identify a macrophage subpopulation responsible for airineme-mediated signaling. These seem to be distinct from conventional skin-resident macrophages by their ameboid morphology and faster or expansive migratory behaviors. They resemble ectoderm-derived macrophages termed metaphocytes. Metaphocyte ablation markedly decreases airineme extension and signaling. In addition, these ameboid/metaphocytes require matrix metalloproteinase-9 for their migration and airineme-mediated signaling. These results reveal a macrophage subpopulation with specialized functions in airineme-mediated signaling, which may play roles in other aspects of intercellular communication.