Regulation Of Notch Signaling Research Articles

Activation of Notch Signaling Pathway is involved in Extracellular Matrix Degradation in human induced pluripotent stem cells chondrocytes induced by HT-2 toxin

Notch signaling regulates cartilage formation and homeostasis. Kashin-Beck Disease (KBD), an endemic osteochondropathy, is characterized by severe cartilage degradation. The etiology of KBD is related to the exposure of HT-2 toxin, a mycotoxin and primary metabolite of T-2 toxin. This study aims to explore the role of HT-2 toxin in the Notch signaling regulation and extracellular matrix (ECM) metabolism of hiPSCs-Chondrocytes. Immunohistochemistry and qRT-PCR were employed to investigate the expression of Notch pathway molecules in KBD articular cartilage and primary chondrocytes. hiPSCs-Chondrocytes, derived from hiPSCs, were treated with 100 ng/mL HT-2 toxin and the γ-secretase inhibitor (DAPT) for 48h, respectively. The markers related to the Notch signaling pathway and ECM were assessed using qRT-PCR and Western blot. Notch pathway dysregulation was prominent in KBD cartilage. HT-2 toxin exposure caused cytotoxicity in hiPSCs-Chondrocytes, and activated Notch signaling by increasing the mRNA and protein levels of NOTCH1 and HES1. HT-2 toxin also upregulated ECM catabolic enzymes and downregulated ECM components (COL2A1 and ACAN), indicating ECM degradation. DAPT-mediated Notch signaling inhibition suppressed the mRNA and protein level of ADAMTS5 expression while enhancing ECM component expression in hiPSCs-Chondrocytes. This study suggests that HT-2 toxin may induce ECM degradation in hiPSCs-Chondrocytes through activating Notch signaling.

Fucoidan alleviates high sucrose-induced metabolic disorders and enhances intestinal homeostasis through modulation of Notch signaling

IntroductionThe therapeutic potential of fucoidan (FUC), a natural polysaccharide, in metabolic disorders is recognized, yet its underlying mechanisms remain unclear. MethodsWe conducted investigations into the therapeutic mechanisms of FUC sourced from Sargassum fulvellum concerning metabolic disorders induced by a high-sucrose diet (HSD), employing Drosophila melanogaster and mice models. Drosophila larvae were subjected to HSD exposure to monitor growth inhibition, reduced pupation, and developmental delays. Additionally, we examined the impact of FUC on growth- and development-related hormones in Drosophila. Furthermore, we assessed the modulation of larval intestinal homeostasis by FUC, focusing on the regulation of Notch signaling. In mice, we evaluated the effects of FUC on HSD-induced impairments in intestinal epithelial barrier integrity and gut hormone secretion. ResultsFUC supplementation significantly enhanced pupal weight in Drosophila larvae and effectively countered HSD-induced elevation of glucose and triglyceride levels. It notably influenced the expression of growth- and development-related hormones, particularly augmenting insulin-like peptides production while mitigating larval growth retardation. FUC also modulated larval intestinal homeostasis by negatively regulating Notch signaling, thereby protecting against HSD-induced metabolic stress. In mice, FUC ameliorated HSD-induced impairments in ileum epithelial barrier integrity and gut hormone secretion. ConclusionsOur findings demonstrate the multifaceted therapeutic effects of FUC in mitigating metabolic disorders and maintaining intestinal health. FUC holds promise as a therapeutic agent, with its effects attributed partly to the sulfate group and its ability to regulate Notch signaling, emphasizing its potential for addressing metabolic disorders.

The bidirectional effects of APPswe on the osteogenic differentiation of MSCs in bone homeostasis by regulating Notch signaling

Amyloid precursor protein (APP), especially Swedish mutant APP (APPswe), is recognized as a significant pathogenic protein in Alzheimer's disease, but limited research has been conducted on the correlation between APPswe and the osteogenic differentiation of mesenchymal stem cells (MSCs). The effects of APPswe and its intracellular and extracellular segments on the osteogenic differentiation of bone morphogenetic protein 2 (BMP2)-induced MSCs were analyzed in this study. Our analysis of an existing database revealed that APP was positively correlated with the osteogenic differentiation of MSCs but negatively correlated with their proliferation and migration. Furthermore, APPswe promoted BMP2-induced osteogenic differentiation of MSCs, while APPswe-C (APPswe without an intracellular segment) had the opposite effect; thus, the intracellular domain of APPswe may be a key factor in promoting the osteogenic differentiation of MSCs. Additionally, both APPswe and APPswe-C inhibited the proliferation and migration of MSCs. Furthermore, the intracellular domain of APPswe inhibited the activity of the Notch pathway by regulating the expression of the Notch intracellular domain to promote the osteogenic differentiation of MSCs. Finally, APPswe-treated primary rat bone marrow MSCs exhibited the most favorable bone repair effect when a GelMA hydrogel loaded with BMP2 was used for in vivo experiments, while APPswe-C had the opposite effect. These findings demonstrate that APPswe promotes the osteogenic differentiation of MSCs by regulating the Notch pathway, but its extracellular segment blocks the self-renewal, proliferation, and migration of MSCs, ultimately leading to a gradual decrease in the storage capacity of MSCs and affecting long-term bone formation.

Regulation of Notch signaling by non-muscle myosin II Zipper in Drosophila

The Notch pathway is an evolutionarily conserved signaling system that is intricately regulated at multiple levels and it influences different aspects of development. In an effort to identify novel components involved in Notch signaling and its regulation, we carried out protein interaction screens which identified non-muscle myosin II Zipper (Zip) as an interacting partner of Notch. Physical interaction between Notch and Zip was further validated by co-immunoprecipitation studies. Immunocytochemical analyses revealed that Notch and Zip co-localize within same cytoplasmic compartment. Different alleles of zip also showed strong genetic interactions with Notch pathway components. Downregulation of Zip resulted in wing phenotypes that were reminiscent of Notch loss-of-function phenotypes and a perturbed expression of Notch downstream targets, Cut and Deadpan. Further, synergistic interaction between Notch and Zip resulted in highly ectopic expression of these Notch targets. Activated Notch-induced tumorous phenotype of larval tissues was enhanced by over-expression of Zip. Notch-Zip synergy resulted in the activation of JNK pathway that consequently lead to MMP activation and proliferation. Taken together, our results suggest that Zip may play an important role in regulation of Notch signaling.

Progression of Notch signaling regulation of B cells under radiation exposure.

With the continuous development of nuclear technology, the radiation exposure caused by radiation therapy is a serious health hazard. It is of great significance to further develop effective radiation countermeasures. B cells easily succumb to irradiation exposure along with immunosuppressive response. The approach to ameliorate radiation-induced B cell damage is rarely studied, implying that the underlying mechanisms of B cell damage after exposure are eager to be revealed. Recent studies suggest that Notch signaling plays an important role in B cell-mediated immune response. Notch signaling is a critical regulator for B cells to maintain immune function. Although accumulating studies reported that Notch signaling contributes to the functionality of hematopoietic stem cells and T cells, its role in B cells is scarcely appreciated. Presently, we discussed the regulation of Notch signaling on B cells under radiation exposure to provide a scientific basis to prevent radiation-induced B cell damage.

Endothelial POFUT1 controls injury-induced liver fibrosis by repressing fibrinogen synthesis

NOTCH signaling in liver sinusoidal endothelial cells (LSECs) regulates liver fibrosis, a pathological feature of chronic liver diseases. POFUT1 is an essential regulator of NOTCH signaling. Here, we investigated the role of LSEC-expressed POFUT1 in liver fibrosis. Endothelial-specific Pofut1 knockout mice were generated and experimental liver fibrosis was induced by chronic carbon tetrachloride exposure or common bile duct ligation. Liver samples were assessed by ELISA, histology, electron microscopy, immunostaining and RNA in situ hybridization. LSECs and hepatic stellate cells (HSCs) were isolated for gene expression analysis by RNA sequencing, qPCR, and western blotting. Signaling crosstalk between LSECs and HSCs was investigated by treating HSCs with supernatant from LSEC cultures. Liver single-cell RNA sequencing datasets from patients with cirrhosis and healthy individuals were analyzed to evaluate the clinical relevance of gene expression changes observed in mouse studies. POFUT1 loss promoted injury-induced LSEC capillarization and HSC activation, leading to aggravated liver fibrosis. RNA sequencing analysis revealed that POFUT1 deficiency upregulated fibrinogen expression in LSECs. Consistently, fibrinogen was elevated in LSECs of patients with cirrhosis. HSCs treated with supernatant from LSECs of Pofut1 null mice showed exacerbated activation compared to those treated with supernatant from control LSECs, and this effect was attenuated by knockdown of fibrinogen or by pharmacological inhibition of fibrinogen receptor signaling, altogether suggesting that LSEC-derived fibrinogen induced the activation of HSCs. Mechanistically, POFUT1 loss augmented fibrinogen expression by enhancing NOTCH/HES1/STAT3 signaling. Endothelial POFUT1 prevents injury-induced liver fibrosis by repressing the expression of fibrinogen, which functions as a profibrotic paracrine signal to activate HSCs. Therapies targeting the POFUT1/fibrinogen axis offer a promising strategy for the prevention and treatment of fibrotic liver diseases. Paracrine signals produced by liver vasculature play a major role in the development of liver fibrosis, which is a pathological hallmark of most liver diseases. Identifying those paracrine signals is clinically relevant in that they may serve as therapeutic targets. In this study, we discovered that genetic deletion of Pofut1 aggravated experimental liver fibrosis in mouse models. Moreover, fibrinogen was identified as a downstream target repressed by Pofut1 in liver endothelial cells and functioned as a novel paracrine signal that drove liver fibrosis. In addition, fibrinogen was found to be relevant to cirrhosis and may serve as a potential therapeutic target for this devastating human disease.

Identifications of three novel alleles of Serrate in Drosophila

The Notch signaling pathway, an evolutionarily highly conserved pathway, participates in various essential physiological processes in organisms. Activation of Notch signaling in the canonical manner requires the combination of ligand and receptor. There are two ligands of Notch in Drosophila: Delta (Dl) and Serrate (Ser). A mutation mf157 is identified for causing nicks of fly wings in genetic analysis from a mutant library (unpublished) that was established previously. Immunofluorescent staining illustrates that mf157 represses the expression of Cut and Wingless (Wg), the targets of Notch signaling. MARCM cloning analysis reveals that mf157 functions at the same level or the upstream of ligands of Notch in signaling sending cells. Sequencing demonstrates that mf157 is a novel allele of the Ser gene. Subsequently, mf553 and mf167 are also identified as new alleles of Ser from our library. Furthermore, the complementary assays and the examination of transcripts confirm the sequencing results. Besides, the repressed phenotypes of Notch signaling were reverted by transposon excision experiments of mf157. In conclusion, we identify three fresh alleles of Ser. Our works supply additional genetic resources for further study of functions of Ser and Notch signaling regulation.

Effects of simvastatin on immunoreaction and inflammation in rats with asthma by regulating NOTCH signaling pathway.

To investigate the effect of simvastatin on the immunoreaction and inflammation in rats with asthma through the NOTCH signaling pathway, a total of 36 Sprague-Dawley (SD) rats were enrolled and randomly divided into the normal group (n=12), model group (n=12) and simvastatin group (n=12). The rats in the normal group were fed normally, those in the model group were prepared into models of asthma, and those in the simvastatin group were prepared into models of asthma and intervened with simvastatin. Next, the morphology of airway tissues was observed via hematoxylin-eosin (HE) staining assay. Besides, immunohistochemistry was employed to determine the expression of interferon-γ (INF-γ), and the relative protein expression levels of NOTCH2 and NOTCH3 were measured by Western blotting (WB). Additionally, enzyme-linked immunosorbent assay (ELISA) and quantitative polymerase chain reaction (qPCR) assay were carried out to detect the content of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) and the relative mRNA expression levels of INF-γ, IL-6 and TNF-α, respectively. HE staining results uncovered that the airway tissues displayed normal morphology in the normal group and disordered morphology and obvious inflammatory infiltration in the model group. In comparison with the model group, the simvastatin group exhibited significantly improved morphology of airway tissues. Based on immunohistochemistry, the average optical density of INF-γ positive expression was increased in the model group and simvastatin group compared with that in the normal group (P<0.05), and it was distinctly lower in the simvastatin group than that in the model group (P<0.05). The results of WB showed that compared with those in the normal group, the relative protein expression levels of NOTCH2 and NOTCH3 were elevated in model group and simvastatin group (P<0.05), whereas they were overtly reduced in simvastatin group compared with those in model group (P<0.05). It was found through ELISA that the model group and simvastatin group had raised content of IL-6 and TNF-α in comparison with the normal group (P<0.05), while the simvastatin group exhibited markedly decreased content of IL-6 and TNF-α in comparison with the model group (P<0.05). The results of qPCR revealed that the relative mRNA expression levels of INF-γ, IL-6 and TNF-α were distinctly up-regulated in the model group and simvastatin group compared with those in the normal group, displaying statistically significant differences (P<0.05), whereas they were markedly lowered in simvastatin group compared with those in the model group, showing statistically significant differences (P<0.05). Simvastatin represses the immunoreaction and inflammation in rats with asthma by down-regulating the NOTCH signaling pathway.

Analysis of complement system and its related factors in Alzheimer’s disease

Alzheimer’s disease (AD) is a primary cause of dementia. The complement system is closely related to AD pathology and may be a potential target for the prevention and treatment of AD. In our study, we conducted a bioinformatics analysis to analyze the role of the complement system and its related factors in AD using Gene Expression Omnibus (GEO) data. We also conducted a functional analysis. Our study verified that 23 genes were closely related to differentially expressed complement system genes in diseases after intersecting the disease-related complement system module genes and differentially expressed genes. The STRING database was used to predict the interactions between the modular gene proteins of the differential complement system. A total of 21 gene proteins and 44 interaction pairs showed close interactions. We screened key genes and created a diagnostic model. The predictive effect of the model was constructed using GSE5281 and our study indicated that the predictive effect of the model was good. Our study also showed enriched negative regulation of Notch signaling, cytokine secretion involved in the immune response pathway, and cytokine secretion involved in immune response hormone-mediated apoptotic signaling pathway. We hope that our study provides a promising target to prevent and delay the onset, diagnosis, and treatment of AD.

The reciprocal regulation between mitochondrial-associated membranes and Notch signaling in skeletal muscle atrophy

Skeletal muscle atrophy and the inhibition of muscle regeneration are known to occur as a natural consequence of aging, yet the underlying mechanisms that lead to these processes in atrophic myofibers remain largely unclear. Our research has revealed that the maintenance of proper mitochondrial-associated endoplasmic reticulum membranes (MAM) is vital for preventing skeletal muscle atrophy in microgravity environments. We discovered that the deletion of the mitochondrial fusion protein Mitofusin2 (MFN2), which serves as a tether for MAM, in human induced pluripotent stem (iPS) cells or the reduction of MAM in differentiated myotubes caused by microgravity interfered with myogenic differentiation process and an increased susceptibility to muscle atrophy, as well as the activation of the Notch signaling pathway. The atrophic phenotype of differentiated myotubes in microgravity and the regenerative capacity of Mfn2-deficient muscle stem cells in dystrophic mice were both ameliorated by treatment with the gamma-secretase inhibitor DAPT. Our findings demonstrate how the orchestration of mitochondrial morphology in differentiated myotubes and regenerating muscle stem cells plays a crucial role in regulating Notch signaling through the interaction of MAM.

The reciprocal regulation between mitochondrial-associated membranes and Notch signaling in skeletal muscle atrophy

Skeletal muscle atrophy and the inhibition of muscle regeneration are known to occur as a natural consequence of aging, yet the underlying mechanisms that lead to these processes in atrophic myofibers remain largely unclear. Our research has revealed that the maintenance of proper mitochondrial-associated endoplasmic reticulum membranes (MAM) is vital for preventing skeletal muscle atrophy in microgravity environments. We discovered that the deletion of the mitochondrial fusion protein Mitofusin2 (MFN2), which serves as a tether for MAM, in human induced pluripotent stem (iPS) cells or the reduction of MAM in differentiated myotubes caused by microgravity interfered with myogenic differentiation process and an increased susceptibility to muscle atrophy, as well as the activation of the Notch signaling pathway. The atrophic phenotype of differentiated myotubes in microgravity and the regenerative capacity of Mfn2-deficient muscle stem cells in dystrophic mice were both ameliorated by treatment with the gamma-secretase inhibitor DAPT. Our findings demonstrate how the orchestration of mitochondrial morphology in differentiated myotubes and regenerating muscle stem cells plays a crucial role in regulating Notch signaling through the interaction of MAM.

The epigenetics orchestra of Notch signaling: a symphony for cancer therapy.

The aberrant regulation of the Notch signaling pathway, which is a fundamental developmental pathway, has been implicated in a wide range of human cancers. The Notch pathway can be activated by both canonical and noncanonical Notch ligands, and its role can switch between acting as an oncogene or a tumor suppressor depending on the context. Epigenetic modifications have the potential to modulate Notch and its ligands, thereby influencing Notch signal transduction. Consequently, the utilization of epigenetic regulatory mechanisms may present novel therapeutic opportunities for both single and combined therapeutics targeted at the Notch signaling pathway. This review offers insights into the mechanisms governing the regulation of Notch signaling and explores their therapeutic potential.

Context-dependent regulation of Notch signaling in glial development and tumorigenesis.

In the mammalian brain, Notch signaling maintains the cortical stem cell pool and regulates the glial cell fate choice and differentiation. However, the function of Notch in regulating glial development and its involvement in tumorigenesis have not been well understood. Here, we show that Notch inactivation by genetic deletion of Rbpj in stem cells decreases astrocytes but increases oligodendrocytes with altered internal states. Inhibiting Notch in glial progenitors does not affect cell generation but instead accelerates the growth of Notch-deprived oligodendrocyte progenitor cells (OPCs) and OPC-related glioma. We also identified a cross-talk between oligodendrocytes and astrocytes, with premyelinating oligodendrocytes secreting BMP4, which is repressed by Notch, to up-regulate GFAP expression in adjacent astrocytes. Moreover, Notch inactivation in stem cells causes a glioma subtype shift from astroglia-associated to OPC-correlated patterns and vice versa. Our study reveals Notch's context-dependent function, promoting astrocytes and astroglia-associated glioma in stem cells and repressing OPCs and related glioma in glial progenitors.

Pan-cancer tRNA-derived fragment CAT1 coordinates RBPMS to stabilize NOTCH2 mRNA to promote tumorigenesis

Transfer RNA-derived fragments (tRFs) are a class of small non-coding regulatory RNAs that are involved in the pathophysiology of many diseases. However, the role of tRFs in cancer progression remains largely elusive. Here, we demonstrate that a pan-cancer 3'-tRF, CAT1 (cancer associated tRF 1), is ubiquitously upregulated in tumors and associated with poor prognosis of a variety of cancers, including lung cancer. The upregulated CAT1 in cancer cells binds to RNA-binding protein with multiple splicing (RBPMS) and displaces NOTCH2 association from RBPMS, thereby inhibiting the subsequent CCR4-NOT deadenylation-complex-mediated NOTCH2 mRNA decay. The CAT1-enhanced NOTCH2 expression promotes lung cancer cell proliferation and metastasis invitro and invivo. In addition, plasma CAT1 levels are substantially increased in patients with lung cancer compared to non-cancer control subjects. Our findings reveal an intrinsic connection between cancer-specific upregulation of CAT1 and cancer progression, show the regulation of NOTCH signaling in cancer by a 3'-tRF, and highlight its great clinical potential.

EOGT enables residual Notch signaling in mouse intestinal cells lacking POFUT1

Notch signaling determines cell fates in mouse intestine. Notch receptors contain multiple epidermal growth factor-like (EGF) repeats modified by O-glycans that regulate Notch signaling. Conditional deletion of protein O-fucosyltransferase 1 (Pofut1) substantially reduces Notch signaling and markedly perturbs lineage development in mouse intestine. However, mice with inactivated Pofut1 are viable, whereas complete elimination of Notch signaling in intestine is lethal. Here we investigate whether residual Notch signaling enabled by EGF-domain-specific O-linked N-acetylglucosamine transferase (Eogt) permits mice conditionally lacking Pofut1 in intestine to survive. Mice globally lacking Eogt alone were grossly unaffected in intestinal development. In contrast, mice lacking both Eogt and Pofut1 died at ~ 28 days after birth with greater loss of body weight, a greater increase in the number of goblet and Paneth cells, and greater downregulation of the Notch target gene Hes1, compared to Pofut1 deletion alone. These data reveal that both O-fucose and O-GlcNAc glycans are fundamental to Notch signaling in the intestine and provide new insights into roles for O-glycans in regulating Notch ligand binding. Finally, EOGT and O-GlcNAc glycans provide residual Notch signaling and support viability in mice lacking Pofut1 in the intestine.

Synergistic regulation of Notch signaling by different O-glycans promotes hematopoiesis.

Glycosylation of Notch receptors by O-fucose glycans regulates Notch ligand binding and Notch signaling during hematopoiesis. However, roles in hematopoiesis for other O-glycans that modify Notch receptors have not been determined. Here we show that the EGF domain specific GlcNAc transferase EOGT is required in mice for the optimal production of lymphoid and myeloid cells. The phenotype of Eogt null mice was largely cell-autonomous, and Notch target gene expression was reduced in T cell progenitors. Moreover, EOGT supported residual Notch signaling following conditional deletion of Pofut1 in hematopoietic stem cells (HSC). Eogt : Pofut1 double mutant HSC had more severe defects in bone marrow and in T and B cell development in thymus and spleen, compared to deletion of Pofut1 alone. The combined results show that EOGT and O-GlcNAc glycans are required for optimal hematopoiesis and T and B cell development, and that they act synergistically with POFUT1 and O-fucose glycans to promote Notch signaling in lymphoid and myeloid differentiation.

Biallelic variants in FLII cause pediatric cardiomyopathy by disrupting cardiomyocyte cell adhesion and myofibril organization.

Pediatric cardiomyopathy (CM) represents a group of rare, severe disorders that affect the myocardium. To date, the etiology and mechanisms underlying pediatric CM are incompletely understood, hampering accurate diagnosis and individualized therapy development. Here, we identified biallelic variants in the highly conserved flightless-I (FLII) gene in 3 families with idiopathic, early-onset dilated CM. We demonstrated that patient-specific FLII variants, when brought into the zebrafish genome using CRISPR/Cas9 genome editing, resulted in the manifestation of key aspects of morphological and functional abnormalities of the heart, as observed in our patients. Importantly, using these genetic animal models, complemented with in-depth loss-of-function studies, we provided insights into the function of Flii during ventricular chamber morphogenesis in vivo, including myofibril organization and cardiomyocyte cell adhesion, as well as trabeculation. In addition, we identified Flii function to be important for the regulation of Notch and Hippo signaling, crucial pathways associated with cardiac morphogenesis and function. Taken together, our data provide experimental evidence for a role for FLII in the pathogenesis of pediatric CM and report biallelic variants as a genetic cause of pediatric CM.

Iron-responsive element of Divalent metal transporter 1 (Dmt1) controls Notch-mediated cell fates.

Notch receptor activation is regulated by the intramembrane protease γ-secretase, which cleaves and liberates the Notch intracellular domain (Nicd) that regulates gene transcription. While γ-secretase cleavage is necessary, we demonstrate it is insufficient for Notch activation and requires vesicular trafficking. Here, we report Divalent metal transporter 1 (Dmt1, Slc11A2) as a novel and essential regulator of Notch signalling. Dmt1-deficient cells are defective in Notch signalling and have perturbed endolysosomal trafficking and function. Dmt1 encodes for two isoforms, with and without an iron response element (ire). We show that isoform-specific silencing of Dmt1-ire and Dmt1+ire has opposite consequences on Notch-dependent cell fates in cell lines and intestinal organoids. Loss of Dmt1-ire suppresses Notch activation and promotes differentiation, whereas loss of Dmt1+ire causes Notch activation and maintains stem-progenitor cell fates. Dmt1 isoform expression correlates with Notch and Wnt signalling in Apc-deficient intestinal organoids and human colorectal cancers. Consistently, Dmt1-ire silencing induces Notch-dependent differentiation in colorectal cancer cells. These data identify Dmt1 isoforms as binary switches controlling Notch cell fate decisions in normal and tumour cells.

Amarogentin Inhibits Tumor Stem Cell-Like Features of Lung Cancer by Regulating Notch Signaling

Amarogentin, a secoiridoid glycoside isolated from the Indian medicinal plant Swertia chirata, is widely known for its antileishmanial, antioxidative, hypoglycemic, antihepatotoxic, antimalarial, anti-inflammatory, and antimicrobial activities. It has been evaluated for its possible anticancerous role in lung cancer using A549 and H1299 cells as models. The results of these studies show a dose-dependent decrease in cell proliferation, cell migration, and invasion by amarogentin. Furthermore, amarogentin repressed stemness in lung cancer, as shown by a diminution in the expression of DLL4, NICD, and Hes1 proteins. In conclusion, we report for the first time the potential regulatory impact of amarogentin on lung cancer. These findings reveal that amarogentin treatment inhibits tumor stem cell-like features in lung cancer by regulating Notch signaling. Therefore, amarogentin may be deemed as a useful therapeutic drug for lung cancer.

Ccdc85c-Par3 condensates couple cell polarity with Notch to control neural progenitor proliferation

Polarity proteins regulate the proliferation and differentiation of neural progenitors to generate neurons during brain development through multiple signaling pathways. However, how cell polarity couples the signaling pathways remains unclear. Here, we show that coiled-coil domain-containing protein 85c (Ccdc85c) interacts with the polarity protein Par3 to regulate the proliferation of radial glial cells (RGCs) via phase separation coupled to percolation (PSCP). We find that the interaction with Ccdc85c relieves the intramolecular auto-inhibitionof Par3, which leads to PSCP of Par3. Downregulation of Ccdc85c causes RGC differentiation. Importantly, the open conformation of Par3 facilitates the recruitment of the Notch regulator Numb to the Par3 condensates, which might prevent the attenuation of Notch activity to maintain RGC proliferation. Furthermore, ectopic activation of Notch signaling rescues RGC proliferation defects caused by the downregulation of Ccdc85c. These results suggest that Ccdc85c-mediated PSCP of Par3 regulates Notch signaling to control RGC proliferation during brain development.