Immune-like coordinated cell death (CCD) indirectly eliminates target cells via immune activation, bypassing intrinsic programmed cell death. Using RNAi screening in a Drosophila tumor model, we identified a series of genes capable of inducing CCD. Here, we characterize adhesion G protein-coupled receptor ADGRL1 as a key mediator that activates anti-tumor immunity by facilitating cDC1-CD8+ T cell hub formation, as revealed by single-cell transcriptomics. Mechanistically, ADGRL1 ablation activates type I interferon signaling and promotes JAK/STAT1-dependent Decorin secretion, mediated by disrupting the GSK3β/β-catenin pathway. Clinical and database analyses validate ADGRL1 as a promising therapeutic target, and its deletion synergizes with PD-1 blockade to strongly suppress tumor growth. Furthermore, via virtual small molecule screening combined with DARTS (drug affinity responsive target stability), we identify an ADGRL1-targeting compound that demonstrates antitumor efficacy in vivo. Together, our findings reveal an immunoregulatory role for ADGRL1 and highlight its therapeutic potential in cancer treatment.

Although cancer immunotherapy has recently revolutionized treatment, the low response rate to existing immune checkpoint blockade (ICB) underscores the need for new druggable targets. Here, we find that SOAT1 is selectively expressed in cancer stem cell (CSC) and pharmacological inhibition with STK results in robust anti-tumor effects across various preclinical mouse models, including colon, liver, lung, breast, and melanoma cancer, with low toxicity. Mechanistically, treatment with STK (or gene knockdown of Soat1) induces the release of 20(S)-Hydroxycholesterol (20SOHC) from the tumor cells, and downstream activation of the trans-cellular 20SOHC (tumor)- GPR132 pathway in regulatory T cell (Treg), ultimately resulting in the suppression of Treg functions and enhanced dendritic cells and cytotoxic CD8+ T cell responses. Importantly, STK treatment synergizes with anti-PD-1 or anti-CTLA-4 ICB therapy. Thus, our findings identify SOAT1 as a CSC metabolism checkpoint that facilitates immune evasion and SOAT1 inhibition as a promising strategy for advanced cancer immunotherapy.

We previously carried out a genome-wide transgenic RNAi screen in adult Drosophila intestines and identified soluble N-ethylmaleimide-sensitive factor-attachment protein alpha (αSnap), which regulates the survival of intestinal stem cells (ISCs). To further elucidate the function of αSnap in ISC survival, we performed a series of immunofluorescence staining experiments. Our results revealed that the ablation of αSnap in ISCs results in cell death through necrosis rather than apoptosis. The absence of αSnap triggers a series of cellular senescence cascades in the Drosophila gut and brain, including lipid droplet (LD) accumulation, the formation of protein aggregates, mitophagy activation, and elevated reactive oxygen species (ROS) levels. Furthermore, the depletion of αSnap in ISCs promotes the expression of Calr, Prtp, LRP1 and Mcr, which might function downstream of αSnap in regulating the survival of ISCs. In addition, we demonstrated that deficiency of Napa (αSnap homologue in mice) restricts the development of mouse GL261 glioma cell transplantation tumor and induces a senescence cascade in GL261 tumor cells. Overall, these findings indicate that αSnap could serve as a potential therapeutic target for glioma.

The immunosuppressive nature of the tumor microenvironment (TME) and the existence of cancer stem cells (CSCs) present significant hurdles in tumor therapy. The identification of therapeutic agents that can target both CSCs and the TME could be a potential approach to overcome treatment resistance. We conducted an in vivo chemical screen to identify F1929-1458, which is capable of eliciting an organism-wide response to destroy stem cell tumors in Drosophila. We then performed functional validation using a mouse colorectal cancer graft tumor model established with the CT26 cell line characterized by its high content of CSCs. Single-cell sequencing was employed to analyze alterations in the TME. Small molecule pull-down mass spectrometry, cellular thermal shift assay, drug affinity experiment, and molecular docking were utilized to identify the target of F1929-1458. An in vitro co-culture system was applied to establish that the damage-associated molecular patterns (DAMPs) released by the tumor cells are accountable for the activation of dendritic cells (DCs). We demonstrated that F1929-1458 treatment enhanced T cell infiltration and T cell mediated tumor regression, its anti-tumor effect was nullified in nude mice and was abolished after anti-CD3 neutralizing antibody treatment. We found that F1929-1458 binds NFKB1 to activate the NF-κB signaling pathway in tumor cells. The activation further elicits cellular stress, causing tumor cells to release DAMPs (HMGB1-gDNA complex, ATP, and OxLDL). These DAMPs, in turn, stimulate the cGAS-STING and NLRP3 inflammasome pathways in DCs, resulting in the generation of type I IFNs and IL-1β. These cytokines facilitate the maturation of DCs and antigen presentation, ultimately enhancing T cell-mediated anti-tumor immunity. Additionally, we showed that the combination of F1929-1458 and the anti-PD-1 antibody exhibited a synergistic anti-tumor effect. Our study identified a novel NFKB1 agonist that promotes anti-tumor immunity by remodeling the TME and activating DCs and that may provide a new way to overcome resistance to current anti-tumor immunotherapy in colorectal cancer.

In mammals, early embryonic gastrulation process is high energy demanding. Previous studies showed that, unlike endoderm and mesoderm cells, neuroectoderm differentiated from human embryonic stem cells relied on aerobic glycolysis as the major energy metabolic process, which generates lactate as the final product. Here we explored the function of intracellular lactate during neuroectoderm differentiation. Our results revealed that the intracellular lactate level was elevated in neuroectoderm and exogenous lactate could further promote hESCs differentiation towards neuroectoderm. Changing intracellular lactate levels by sodium lactate or LDHA inhibitors had no obvious effect on BMP or WNT/β-catenin signaling during neuroectoderm differentiation. Notably, histone lactylation, especially H3K18 lactylation was significant upregulated during this process. We further performed CUT&Tag experiments and the results showed that H3K18la is highly enriched at gene promoter regions. By analyzing data from CUT&Tag and RNA-seq experiments, we further identified that four genes, including PAX6, were transcriptionally upregulated by lactate during neuroectoderm differentiation. A H3K18la modification site at PAX6 promoter was verified and exogenous lactate could also rescue the level of PAX6 after shPAX6 inhibition.

Introduction: Functional disorder of the placenta is the principal cause of fetal growth restriction (FGR), usually cured with suitable clinical treatment and good nursing. However, some FGR mothers still give birth to small for gestational age (SGA) babies after treatment. The ineffectiveness of treatment in such a group of patients confused physicians of obstetrics and gynecology.Methods: In this study, we performed a microRNA-messenger RNA integrative analysis of gene expression profiles obtained from Gene Expression Omnibus. Differentially expressed genes were screened and checked using quantitative polymerase chain reaction. Target genes of significantly changed microRNA were screened and enriched for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Function of the obtained microRNA-messenger RNA was evaluated using HTR-8/SVneo trophoblast cells, human umbilical vein endothelial cells, and heterozygote male mice.Result: MiR-155-5p was upregulated (p = 0.001, fold-change = 2.275) in fetal-side placentals. Among the hub genes identified as key targets for miR-155-5p in fetal reprogramming, Smad2 was downregulated (p = 0.002, fold change = 0.426) and negatively correlated with miR-155-5p expression levels (r = -0.471, p < 1.0 E - 04) in fetal-side placental tissues. The miR-155-5p mimic blocks Smad2 expression and suppresses villous trophoblast cell and endothelial cell function (proliferation, migration, and invasion), indicating a close relationship with placental development. Luciferase assays further confirmed the targeting of miR-155-5p to Smad2. Furthermore, Smad2(+/-) heterozygote male mice were born small with low body weight (p = 0.0281) and fat composition (p = 0.013) in the fourth week post-natal.Discussion: We provide the first evidence of the role of the Smad2/miR-155-5p axis in the placental pathologies of FGR. Our findings elucidate the pathogenesis of FGR and provide new therapeutic targets.

Aims: The small GTPase protein ARF1 has been shown to be involved in the lipolysis pathway and to selectively kill stem cells in Drosophila melanogaster. However, the role of ARF1 in mammalian intestinal homeostasis re-mains elusive. This study aimed to explore the role of ARF1 in intestinal epithelial cells (IECs) and reveal the possible mechanism. Materials and methods: IEC-specific ARF1 deletion mouse model was used to evaluate the role of ARF1 in in-testine. Immunohistochemistry and immunofluorescence analyses were performed to detect specific cell type markers, and intestinal organoids were cultured to assess intestinal stem cell (ISC) proliferation and differenti-ation. Fluorescence in situ hybridization, 16S rRNA-seq analysis, and antibiotic treatments were conducted to elucidate the role of gut microbes in ARF1-mediated intestinal function and the underlying mechanism. Colitis was induced in control and ARF1-deficient mice by dextran sulfate sodium (DSS). RNA-seq was performed to elucidate the transcriptomic changes after ARF1 deletion. Key findings: ARF1 was essential for ISC proliferation and differentiation. Loss of ARF1 increased susceptibility to DSS-induced colitis and gut microbial dysbiosis. Gut microbiota depletion by antibiotics could rescue the in-testinal abnormalities to a certain extent. Furthermore, RNA-seq analysis revealed alterations in multiple metabolic pathways. Significance: This work is the first to elucidate the essential role of ARF1 in regulating gut homeostasis, and provides novel insights into the pathogenesis of intestinal diseases and potential therapeutic targets.

We previously showed that the Arf1-mediated lipolysis pathway sustains stem cells and cancer stem cells (CSCs); its ablation resulted in necrosis of stem cells and CSCs, which further triggers a systemic antitumor immune response. Here we show that knocking down Arf1 in intestinal stem cells (ISCs) causes metabolic stress, which promotes the expression and translocation of ISC-produced damage-associated molecular patterns (DAMPs; Pretaporter [Prtp] and calreticulin [Calr]). DAMPs regulate macroglobulin complement-related (Mcr) expression and secretion. The secreted Mcr influences the expression and localization of enterocyte (EC)-produced Draper (Drpr) and LRP1 receptors (pattern recognition receptors [PRRs]) to activate autophagy in ECs for ATP production. The secreted ATP possibly feeds back to kill ISCs by activating inflammasome-like pyroptosis. We identify an evolutionarily conserved pathway that sustains stem cells and CSCs, and its ablation results in an immunogenic cascade that promotes death of stem cells and CSCs as well as antitumor immunity.

Mutations in the Lmod3 gene have been identified as a genetic cause of nemaline myopathy. However, the mechanism underlying this disease and the function of Lmod3 remain largely unknown. In this study, we found that Lmod3 knockdown in C2C12 cells impaired myoblast differentiation, whereas enforced Lmod3 expression enhanced such differentiation. We also discovered that myoblast proliferation was promoted by Lmod3 overexpression but impeded by its knockdown. Additionally, knockdown of Lmod3 led to apoptosis in myoblasts. Concurrently, forced Lmod3 expression in C2C12 cells contributed to activation of the AKT and ERK pathways during myoblast differentiation and proliferation, respectively. Conversely, knockdown of Lmod3 in C2C12 cells produced the opposite results. Furthermore, administration of IGF-1, a booster of both AKT and ERK pathways, partially rescued the inhibitory effect of Lmod3 knockdown on both differentiation and proliferation of C2C12 cells. These results suggest that Lmod3 promotes differentiation and proliferation of myoblasts through the AKT and ERK pathways, respectively.

Background Leiomodin proteins, Lmod1, Lmod2 and Lmod3, are key regulators of the thin filament length in muscles. While Lmod1 is specifically expressed in smooth muscles, both Lmod2 and Lmod3 are expressed in striated muscles including both cardiac and skeletal muscles. We and others have previously shown that Lmod3 mainly function in skeletal muscles and the mutant mice display disorganized sarcomere. Lmod2 protein has been found to act as an actin filament nucleator in both cell-free assays and in cultured rat and chicken cardiomyocytes. Results To better understand the function of Lmod2 in vivo, we have identified and characterized a piggyBac ( PB ) insertional mouse mutant. Our analysis revealed that the PB transposon inserts in the first exon of the Lmod2 gene and severely disrupts its expression. We found that Lmod2 PB/PB mice exhibit typical dilated cardiomyopathy (DCM) with ventricular arrhythmias and postnatal lethality. Electron microscope reveals that the Lmod2 PB/PB hearts carry disordered sarcomere, disarrayed thin filaments, and distorted intercalated discs (ICDs). Those ICDs display not only decreased convolutions, but also reduced electron-dense staining, indicating less ICDs component proteins in Lmod2 PB/PB hearts. Consistent with the phenotype, the expression of the ICD component genes, β-catenin and Connexin43, are down-regulated. Conclusions Taken together, our data reveal that Lmod2 is required in heart thin filaments for integrity of sarcomere and ICD and deficient mice exhibit DCM with ventricular arrhythmias and postnatal lethality. The Lmod2 PB/PB mutant offers a valuable resource for interrogation of pathogenesis and development of therapeutics for DCM.

A rise in the occurrence of obesity has driven exploration of its underlying genetic basis and potential targets for intervention. GWAS studies have identified obesity susceptibility pathways involving several neuropeptides that control energy homeostasis, suggesting that variations in the genes that regulate food intake and energy expenditure may contribute to obesity. In this study, we identified 5 additional obesity loci, including a neuronal orphan GPCR called Gpr45, in a forward genetic screen of mutant mice generated by piggyBac insertional mutagenesis. Disruption of Gpr45 led to increased adiposity at the time of weaning and increases in body mass, fat content, glucose intolerance, and hepatic steatosis with advancing age. Mice with disruptions in Gpr45 also displayed a reduction in expression of the metabolic regulator POMC and less energy expenditure prior to the onset of obesity. Mechanistically, we determined that GPR45 regulates POMC expression via the JAK/STAT pathway in a cell-autonomous manner. Consistent with this finding, intraventricular administration of melanotan-2, an analog of the POMC derivative α-MSH, suppressed adult obesity in Gpr45 mutants. These results reveal that GPR45 is a regulator of POMC signaling and energy expenditure, which suggests that it may be a potential intervention target to combat obesity.

Transposons and retroviruses are important pathogenic agents and tools for mutagenesis and transgenesis. Insertion target selection is a key feature for a given transposon or retrovirus. The piggyBac (PB) transposon is highly active in mice and human cells, which has a much better genome-wide distribution compared to the retrovirus and P-element. However, the underlying reason is not clear. Utilizing a tagged functional PB transposase (PBase), we were able to conduct genome-wide profiling for PBase binding sites in the mouse genome. We have shown that PBase binding mainly depends on the distribution of the tetranucleotide TTAA, which is not affected by the presence of PB DNA. Furthermore, PBase binding is negatively influenced by the methylation of CG sites in the genome. Analysis of a large collection of PB insertions in mice has revealed an insertion profile similar to the PBase binding profile. Interestingly, this profile is not correlated with transcriptional active genes in the genome or transcriptionally active regions within a transcriptional unit. This differs from what has been previously shown for P-element and retroviruses insertions. Our study provides an explanation for PB's genome-wide insertion distribution and also suggests that PB target selection relies on a new mechanism independent of active transcription and open chromatin structure.

Nemaline myopathy (NM) is one of the most common forms of congenital myopathy, and affects either fast myofibers, slow myofibers, or both. However, an animal model for congenital myopathy with fast-myofiber-specific atrophy is not available. Furthermore, mutations in the leiomodin-3 (LMOD3) gene have recently been identified in a group of individuals with NM. However, it is not clear how loss of LMOD3 leads to NM. Here, we report a mouse mutant in which the piggyBac (PB) transposon is inserted into the Lmod3 gene and disrupts its expression. Lmod3(PB/PB) mice show severe muscle weakness and postnatal growth retardation. Electron microscopy and immunofluorescence studies of the mutant skeletal muscles revealed the presence of nemaline bodies, a hallmark of NM, and disorganized sarcomeric structures. Interestingly, Lmod3 deficiency caused muscle atrophy specific to the fast fibers. Together, our results show that Lmod3 is required in the fast fibers for sarcomere integrity, and this study offers the first NM mouse model with muscle atrophy that is specific to fast fibers. This model could be a valuable resource for interrogating myopathy pathogenesis and developing therapeutics for NM as well as other pathophysiological conditions with preferential atrophy of fast fibers, including cancer cachexia and sarcopenia.

The placenta is essential for survival and growth of the fetus because it promotes the delivery of nutrients and oxygen from the maternal circulation as well as fetal waste disposal. Mst1 and Mst2 (Mst1/2), key components of the mammalian hpo/Mst signaling pathway, encode two highly conserved Ser/Thr kinases and play important roles in the prevention of tumorigenesis and autoimmunity, control of T cell development and trafficking, and embryonic development. However, their functions in placental development are not fully understood, and the underlying cellular and molecular mechanisms remain elusive. Here, we investigated the functions of Mst1/2 in mouse placental development using both conventional and conditional (endothelial) Mst1/2 double knockout mice. We found that the number of trophoblast giant cells dramatically increased while spongiotrophoblast cells almost completely disappeared in Mst1/2 deficient placentas. We showed that Mst1/2 deficiency down regulated the expression of Mash2, which is required for suppressing the differentiation of trophoblast giant cells. Furthermore, we demonstrated that endothelial-specific deletion of Mst1/2 led to impaired placental labyrinthine vasculature and embryonic lethality at E11.5, but neither affected vasculature in yolk sac and embryo proper nor endocardium development. Collectively, our findings suggest that Mst1/2 regulate placental development by control of trophoblast cell differentiation and labyrinthine vasculature at midgestation and Mst1/2 control labyrinth morphogenesis in trophoblast- and fetal endothelial-dependent manners. Thus, our studies have defined novel roles of Mst1/2 in mouse placental development.

We present a systemic study on the tailoring of light emission properties of the GaN-based light-emitting diodes (LEDs) with nanoparticle-assembled on-top layers. A layer of silver nanoparticles is deposited on the top of the InGaN/GaN quantum wells (QWs) in gas-phase. The coupling of spontaneous emission from InGaN QWs into the surface plasmon modes of silver nanoparticle layer is demonstrated. The effect of the silver nanoparticle arrays on the extraction efficiency of the emitted light is also investigated. We show that the nanoparticles on-top layers can be used to enhance the light output of LEDs either by increasing the internal quantum efficiency through surface plasmon coupling or by increasing the light extraction efficiency through near field interaction with the evanescent field induced by the total internal reflection of the light.

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Background Insertional mutagenesis is an effective method for functional genomic studies in various organisms. It can rapidly generate easily tractable mutations. A large-scale insertional mutagenesis with the piggyBac (PB) transposon is currently performed in mice at the Institute of Developmental Biology and Molecular Medicine (IDM), Fudan University in Shanghai, China. This project is carried out via collaborations among multiple groups overseeing interconnected experimental steps and generates a large volume of experimental data continuously. Therefore, the project calls for an efficient database system for recording, management, statistical analysis, and information exchange. Results This paper presents a database application called MP-PBmice (insertional mutation mapping system of PB Mutagenesis Information Center), which is developed to serve the on-going large-scale PB insertional mutagenesis project. A lightweight enterprise-level development framework Struts-Spring-Hibernate is used here to ensure constructive and flexible support to the application. The MP-PBmice database system has three major features: strict access-control, efficient workflow control, and good expandability. It supports the collaboration among different groups that enter data and exchange information on daily basis, and is capable of providing real time progress reports for the whole project. MP-PBmice can be easily adapted for other large-scale insertional mutation mapping projects and the source code of this software is freely available at http://www.idmshanghai.cn/PBmice . Conclusion MP-PBmice is a web-based application for large-scale insertional mutation mapping onto the mouse genome, implemented with the widely used framework Struts-Spring-Hibernate. This system is already in use by the on-going genome-wide PB insertional mutation mapping project at IDM, Fudan University.

We determined the physical locations of the heterodimeric Ecdysone receptor/Ultraspiracle (ECR/USP) nuclear hormone receptor complex throughout the entire nonrepetitive genome of Drosophila melanogaster using a cell line (Kc167) that differentiates in response to 20-hydroxyecdysone (20-HE). 20-HE, the natural ligand of this complex, controls major aspects of insect development, including molting, metamorphosis, and reproduction. Direct gene targets of 20-HE signaling were identified by combining this physical binding-site profiling with gene expression profiling after treatment with 20-HE. We found 502 significant regions of ECR/USP binding throughout the genome. Only 42% of these regions are nearby genes that are 20-HE responsive in these cells. However, at least three quarters of the remaining ECR/USP regions are near 20-HE-regulated genes in other tissue and cell types during metamorphosis, suggesting that binding at many regulatory elements in the genome is largely noncell-type specific. The majority (21/26) of the early targets of 20-HE encode transcriptional regulatory factors. To determine whether any of these targets are required for the morphological differentiation of these cells, we used RNAi to reduce the expression of each of the 26 early genes. Accordingly, we found that three direct targets of ECR/USP-hairy, vrille, and Hr4-are required for cellular differentiation in response to the hormone. Initial mutational analysis of vrille in vivo reveals that it is required for metamorphosis.