Lycopene promoted M2 macrophage polarization via inhibition of NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to Escherichia coli infection in J744A.1 cells.

Escherichia coli (E. coli) can induce severe clinical bovine mastitis, which is to blame for large losses experienced by dairy farms. Macrophage polarization into various states is in response to pathogen infections. Lycopene, a naturally occurring hydrocarbon carotenoid, relieved inflammation by controlling M1/M2 status of macrophages. Thus, we wanted to explore the effect of lycopene on polarization states of macrophages in E. coli-induced mastitis. Macrophages were cultivated with lycopene for 24, before E. coli inoculation for 6 h. Lycopene (0.5 µmol/L) significantly enhanced cell viabilities and significantly reduced lactic dehydrogenase (LDH) levels in macrophages, whereas 2 and 3 µmol/L lycopene significantly enhanced LDH activities. Lycopene treatment significantly reduced the increase in LDH release, iNOS, CD86, TNF-α, IL-1ß and phosphatase and tensin homolog (PTEN) expressions in E. coli group. 0.5 µmol/L lycopene significantly increased E. coli-induced downregulation of CD206, arginase I (ARG1), indoleamine 2,3-dioxygenase (IDO), chitinase 3-like 3 (YM1), PI3K, AKT, p-AKT, mammalian target of rapamycin (mTOR), p-mTOR, jumonji domain-containing protein-3 (JMJD3) and interferon regulatory factor 4 (IRF4) levels. Moreover, Ginkgolic acid C17:1 (a specific PTEN inhibitor), 740YPDGFR (a specific PI3K activator), SC79 (a specific AKT activator) or CHPG sodium salt (a specific NF-κB activator) significantly decreased CD206, AGR1, IDO and YM1 expressions in lycopene and E. coli-treated macrophages. Therefore, lycopene increased M2 macrophages via inhibiting NOTCH1-PI3K-mTOR-NF-κB-JMJD3-IRF4 pathway in response to E. coli infection in macrophages. These results contribute to revealing the pathogenesis of E. coli-caused bovine mastitis, providing the new angle of the prevention and management of mastitis.

Role of Mutation of NOTCH1 gene in development of oral squamous cell carcinoma: a narrative review.

Cancer of the oral cavity has numerous types and, among all, oral squamous cell carcinoma represents >90% of all cancers of the oral area. Oral squamous cell carcinoma arises from the squamous lining of the oral cavity. Across the globe, most commonly it develops in the regions of tongue followed by floor of the mouth, and lower lip. Neurogenic locus notch homolog protein 1 gene has its association with oral squamous cell carcinoma and is known to be associated with both oncogenic and tumour suppressor roles. The current narrative review comprised literature published from 2013 to 2023. It was searched on Google Scholar, PubMed and Google databases. Globally, neurogenic locus notch homolog protein 1 mutations are associated with the development of oral squamous cell carcinoma. Most of the mutations are linked to ligand bind epidermal growth factor-like repeat region of extracellular domain of neurogenic locus notch homolog protein 1. Once activated, the pathway is involved in tumour progression and metastasis. The Asians compared to Caucasians are more affected by neurogenic locus notch homolog protein 1 mutations.

NRN1 interacts with Notch to increase oncogenic STAT3 signaling in melanoma.

BACKGROUND: Melanoma is a highly heterogeneous cancer, in which frequent changes in activation of signaling pathways lead to a high adaptability to ever changing tumor microenvironments. The elucidation of cancer specific signaling pathways is of great importance, as demonstrated by the inhibitor of the common BrafV600E mutation PLX4032 in melanoma treatment. We therefore investigated signaling pathways that were influenced by neurotrophin NRN1, which has been shown to be upregulated in melanoma. METHODS: Using a cell culture model system with an NRN1 overexpression, we investigated the influence of NRN1 on melanoma cells' functionality and signaling. We employed real time cell analysis and spheroid formation assays, while for investigation of molecular mechanisms we used a kinase phosphorylation kit as well as promotor activity analysis followed by mRNA and protein analysis. RESULTS: We revealed that NRN1 interacts directly with the cleaved intracellular domain (NICD) of Notch1 and Notch3, causing a potential retention of NICD in the cytoplasm and thereby reducing the expression of its direct downstream target Hes1. This leads to decreased sequestration of JAK and STAT3 in a Hes1-driven phosphorylation complex. Consequently, our data shows less phosphorylation of STAT3 while presenting an accumulation of total protein levels of STAT3 in association with NRN1 overexpression. The potential of the STAT3 signaling pathway to act in both a tumor suppressive and oncogenic manner led us to investigate specific downstream targets - namely Vegf A, Mdr1, cMet - which were found to be upregulated under oncogenic levels of NRN1. CONCLUSIONS: In summary, we were able to show that NRN1 links oncogenic signaling events between Notch and STAT3 in melanoma. We also suggest that in future research more attention should be payed to cellular regulation of signaling molecules outside of the classically known phosphorylation events.

Linarin Ameliorates Restenosis After Vascular Injury in Type 2 Diabetes Mellitus via Regulating ADAM10-Mediated Notch Signaling Pathway.

Vascular lesions frequently arise as complication in patients diagnosed with diabetes mellitus (DM). Presently, percutaneous coronary intervention (PCI) and antithrombotic therapy serve as primary treatments. However, in-stent restenosis persists as a challenging clinical issue following PCI, lacking sustained and effective treatment. Linarin (LN) exhibits diverse pharmacological activities and is regarded as a potential drug for treating various diseases, including DM. But its specific role in restenosis after vascular injury in DM patients remains unclear. A rat model of diabetes-related restenosis was established to evaluate the role of LN on neointimal hyperplasia. Vascular smooth muscle cells (VSMCs) stimulated by high glucose (HG, 30 mM) underwent LN treatment. Additionally, an overexpression plasmid of A disintegrin and metalloproteinases (ADAM10) was constructed to transfect VSMCs. We employed CCK-8, Brdu, wound-healing scratch, and transwell migration assays to evaluate the proliferation and migration of VSMCs. Furthermore, western blot and immunofluorescence assays were utilized to investigate the expressions of ADAM10 and the downstream Notch signaling pathway in vivo and in vitro models. LN notably alleviated intimal hyperplasia after vascular injury in DM rats and reduced the protein expression of ADAM10, alongside its downstream Notch1 signaling pathway-related proteins (Notch1, NICD and Hes1) in rat carotid artery tissues. LN effectively suppressed the proliferation and migration of VSMCs induced by HG, downregulating the protein expression of ADAM10, Notch1, NICD and Hes1. Moreover, our findings indicated that ADAM10 overexpression significantly reversed LN's effects on proliferation, migration, and the expression of Notch1 signaling pathway-related proteins in HG-treated VSMCs. LN demonstrates potential therapeutic efficacy in addressing restenosis after diabetic-related vascular injury, with the ADAM10 mediated Notch signaling pathway playing a pivotal role.

Specific Knockout of Notch-1 in Macrophages Modulate the Progression of Hepatic Insulin Resistance in HFD Fed Mice via Regulating IRE1α-XBP1 Signals.

OBJECTIVE: To develop an intervention based on Notch-1 signalling pathway blockade by investigating the potential application of the neurogenic locus notch homologue protein 1(Notch-1) signalling pathway as a key regulator of chronic inflammation and adipogenesis in the treatment of hepatic insulin resistance (HIR). STUDY DESIGN: Experimental study. Place and Duration of the Study: Animal Laboratory of the Fourth Hospital of Hebei Medical University, Shijiazhuang, China, from April 2021 to June 2022. METHODOLOGY: HIR models were established in Notch-1WT and Notch-1MAC-KO mice by high fat diet (HFD) for 16 weeks. Haematoxylin and eosin (HE) staining and oil red O (ORO) staining were used to detect inflammatory infiltration and lipid accumulation in each group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of TNF-α and IL-6. Free fatty acid (FFA) and total cholesterol (TC) were measured with relevant kits. Moreover, real-time quantitative polymerase chain reaction (PCR) was performed to detect the relative expressions of F4/80, Mcp1, and CD11b in hepatic tissues. Mass spectrometry was used to analyse the levels of triglyceride (TG), diacylglycerol (DAG) and conformite europeenne (CE) in liver tissue. Western blotting was used to detect the expression of related proteins. RESULTS: Specific knockdown of Notch-1 in macrophages decreases the relative fluorescence intensity of CD68 and attenuates inflammatory infiltration and lipid degeneration. There was no difference in plasma levels of FFA and TG. Specific knockdown of Notch-1 in macrophages decreases the expression of F4/80, Mcp1, and CD11b, as well as the levels of TG, DAG, CE, IL-6, and TNF-α. CONCLUSION: Specific knockout of Notch-1 in macrophages may reduce HIR by inhibiting the IRE1α-XBP1 signalling pathway. KEY WORDS: Hepatic insulin resistance, Macrophages, Notch-1, IRE1α, XBP1.

Triptolide, a Cancer Cell Proliferation Inhibitor, Causes Zebrafish Muscle Defects by Regulating Notch and STAT3 Signaling Pathways.

Triptolide is a natural compound in herbal remedies with anti-inflammatory and anti-proliferative properties. We studied its effects on critical signaling processes within the cell, including Notch1 and STAT3 signaling. Our research showed that triptolide reduces cancer cell proliferation by decreasing the expression of downstream targets of these signals. The levels of each signal-related protein and mRNA were analyzed using Western blot and qPCR methods. Interestingly, inhibiting one signal with a single inhibitor alone did not significantly reduce cancer cell proliferation. Instead, MTT assays showed that the simultaneous inhibition of Notch1 and STAT3 signaling reduced cell proliferation. The effect of triptolide was similar to a combination treatment with inhibitors for both signals. When we conducted a study on the impact of triptolide on zebrafish larvae, we found that it inhibited muscle development and interfered with muscle cell proliferation, as evidenced by differences in the staining of myosin heavy chain and F-actin proteins in confocal fluorescence microscopy. Additionally, we noticed that inhibiting a single type of signaling did not lead to any significant muscle defects. This implies that triptolide obstructs multiple signals simultaneously, including Notch1 and STAT3, during muscle development. Chemotherapy is commonly used to treat cancer, but it may cause muscle loss due to drug-related adverse reactions or other complex mechanisms. Our study suggests that anticancer agents like triptolide, inhibiting essential signaling pathways including Notch1 and STAT3 signaling, may cause muscle atrophy through anti-proliferative activity.

SKP2-mediated ubiquitination and degradation of KLF11 promotes osteoarthritis via modulation of JMJD3/NOTCH1 pathway.

Osteoarthritis (OA) is the main cause of cartilage damage and disability. This study explored the biological function of S-phase kinase-associated protein 2 (SKP2) and Kruppel-like factor 11 (KLF11) in OA progression and its underlying mechanisms. C28/I2 chondrocytes were stimulated with IL-1ß to mimic OA in vitro. We found that SKP2, Jumonji domain-containing protein D3 (JMJD3), and Notch receptor 1 (NOTCH1) were upregulated, while KLF11 was downregulated in IL-1ß-stimulated chondrocytes. SKP2/JMJD3 silencing or KLF11 overexpression repressed apoptosis and extracellular matrix (ECM) degradation in chondrocytes. Mechanistically, SKP2 triggered the ubiquitination and degradation of KLF11 to transcriptionally activate JMJD3, which resulted in activation of NOTCH1 through inhibiting H3K27me3. What's more, the in vivo study found that KLF11 overexpression delayed OA development in rats via restraining apoptosis and maintaining the balance of ECM metabolism. Taken together, ubiquitination and degradation of KLF11 regulated by SKP2 contributed to OA progression by activation of JMJD3/NOTCH1 pathway. Our findings provide promising therapeutic targets for OA.

Arjunolic acid ameliorates lipopolysaccharide-induced depressive behavior by inhibiting neuroinflammation via microglial SIRT1/AMPK/Notch1 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Neuroinflammation is involved in the pathogenesis of depression disorder by activating microglia cells, increasing proinflammatory cytokines, effecting serotonin synthesis and metabolism, and neuronal apoptosis and neurogenesis. Arjunolic acid (ARG) is a triterpenoid derived from the fruits of Akebia trifoliata for treating psychiatric disorders in TCM clinic, which exhibits anti-inflammatory and neuroprotective effects. However, its anti-depressive effect and underlying mechanism are unknown. AIM OF THE STUDY: The aim of this study is to explore the effect of arjunolic acid on depression and its possible mechanisms. METHODS: Intraperitoneal injection of LPS in mice and LPS stimulated-BV2 microglia were utilized to set up in vivo and in vitro models. Behavioral tests, H&E staining and ELISA were employed to evaluate the effect of arjunolic acid on depression. RT-qPCR, immunofluorescence, molecular docking and Western blot were performed to elucidate the molecular mechanisms. RESULTS: Arjunolic acid dramatically ameliorated depressive behavior in LPS-induced mice. The levels of BDNF and 5-HT in the hippocampus of the mice were increased, while the number of iNOS + IBA1+ cells in the brain were decreased and Arg1+IBA1+ positive cells were increased after arjunolic acid treatment. In addition, arjunolic acid promoted the polarization of BV2 microglia from M1 to M2 type. Notably, drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA) and molecular docking technologies identified SIRT1 as the target of arjunolic acid. Moreover, after SIRT1 inhibition by using EX-527, the effects of arjunolic acid on ameliorating LPS-induced depressive behavior in mice and promoting M2 Microglia polarization were blocked. In addition, arjunolic acid activated AMPK and decreased Notch1 expression, however, inhibition of AMPK, the effect of arjunolic acid on the downregulation of Notch1 expression were weaken. CONCLUSIONS: This study elucidates that arjunolic acid suppressed neuroinflammation through modulating the SIRT1/AMPK/Notch1 signaling pathway. Our study demonstrates that arjunolic acid might serve as a potiential anti-depressant.

Mutant IDH inhibitors induce lineage differentiation in IDH-mutant oligodendroglioma.

A subset of patients with IDH-mutant glioma respond to inhibitors of mutant IDH (IDHi), yet the molecular underpinnings of such responses are not understood. Here, we profiled by single-cell or single-nucleus RNA-sequencing three IDH-mutant oligodendrogliomas from patients who derived clinical benefit from IDHi. Importantly, the tissues were sampled on-drug, four weeks from treatment initiation. We further integrate our findings with analysis of single-cell and bulk transcriptomes from independent cohorts and experimental models. We find that IDHi treatment induces a robust differentiation toward the astrocytic lineage, accompanied by a depletion of stem-like cells and a reduction of cell proliferation. Furthermore, mutations in NOTCH1 are associated with decreased astrocytic differentiation and may limit the response to IDHi. Our study highlights the differentiating potential of IDHi on the cellular hierarchies that drive oligodendrogliomas and suggests a genetic modifier that may improve patient stratification.

Jagged2 targeting in lung cancer activates anti-tumor immunity via Notch-induced functional reprogramming of tumor-associated macrophages.

Signaling through Notch receptors intrinsically regulates tumor cell development and growth. Here, we studied the role of the Notch ligand Jagged2 on immune evasion in non-small cell lung cancer (NSCLC). Higher expression of JAG2 in NSCLC negatively correlated with survival. In NSCLC pre-clinical models, deletion of Jag2, but not Jag1, in cancer cells attenuated tumor growth and activated protective anti-tumor T cell responses. Jag2-/- lung tumors exhibited higher frequencies of macrophages that expressed immunostimulatory mediators and triggered T cell-dependent anti-tumor immunity. Mechanistically, Jag2 ablation promoted Nr4a-mediated induction of Notch ligands DLL1/4 on cancer cells. DLL1/4-initiated Notch1/2 signaling in macrophages induced the expression of transcription factor IRF4 and macrophage immunostimulatory functionality. IRF4 expression was required for the anti-tumor effects of Jag2 deletion in lung tumors. Antibody targeting of Jagged2 inhibited tumor growth and activated IRF4-driven macrophage-mediated anti-tumor immunity. Thus, Jagged2 orchestrates immunosuppressive systems in NSCLC that can be overcome to incite macrophage-mediated anti-tumor immunity.

Increased AXLhigh myeloid cells as pathognomonic marker in Langerhans cell histiocytosis and Langerin expression dependence of mTOR inhibition.

Langerhans cell histiocytosis (LCH) is characterized by an expansion and accumulation of pathological histiocytes expressing langerin (CD207) and CD1a in different organs under an inflammatory milieu. The origin of pathognomonic precursors of LCH is widely debated, but monocytes and pre-dendritic cells (pre-DC) play a significant role. Remarkably, we found an expansion of AXLhigh cells in the CD11c+ subset of patients with active LCH, which also express the pathognomonic CD207 and CD1a. Moreover, we obtained a monocyte-derived LC-like (mo-LC-like) expressing high levels of AXL when treated with inflammatory cytokine, or plasma of patients with active disease. Intriguingly, inhibiting the mTOR pathway at the initial stages of monocyte differentiation to LC-like fosters the pathognomonic LCH program, highly increasing CD207 levels, together with NOTCH1 induction. We define here that AXLhigh could also be taken as a strong pathognomonic marker for LCH, and the release of Langerin and NOTCH1 expression depends on the inhibition of the mTOR pathway.

Prognostic value of CD8+T cells related genes and exhaustion regulation of Notch signaling pathway in hepatocellular carcinoma.

Immunotherapy has emerged as the primary treatment modality for patients with advanced Hepatocellular carcinoma (HCC). However, its clinical efficacy remains limited, benefiting only a subset of patients, while most exhibit immune tolerance and face a grim prognosis. The infiltration of immune cells plays a pivotal role in tumor initiation and progression. In this study, we conducted an analysis of immune cell infiltration patterns in HCC patients and observed a substantial proportion of CD8+T cells. Leveraging the weighted gene co-expression network analysis (WGCNA), we identified 235 genes associated with CD8+T cell and constructed a risk prediction model. In this model, HCC patients were stratified into a high-risk and low-risk group. Patients in the high-risk group exhibited a lower survival rate, predominantly presented with intermediate to advanced stages of cancer, displayed compromised immune function, showed limited responsiveness to immunotherapy, and demonstrated elevated expression levels of the Notch signaling pathway. Further examination of clinical samples demonstrated an upregulation of the Notch1+CD8+T cell exhaustion phenotype accompanied by impaired cytotoxicity and cytokine secretion functions that worsened with increasing Notch activation levels. Our study not only presents a prognostic model but also highlights the crucial involvement of the Notch pathway in CD8+T cell exhaustion-a potential target for future immunotherapeutic interventions.

Inhibition of SUV39H1 reduces tumor angiogenesis via Notch1 in oral squamous cell carcinoma.

Targeting tumor angiogenesis is an important approach in advanced tumor therapy. Here we investigated the effect of the suppressor of variegation 3-9 homolog 1 (SUV39H1) on tumor angiogenesis in oral squamous cell carcinoma (OSCC). The GEPIA database was used to analyze the expression of SUV39H1 in various cancer tissues. The expression of SUV39H1 in OSCC was detected by immunohistochemistry, and the correlation between SUV39H1 and Notch1 and microvascular density (MVD) was analyzed. The effect of SUV39H1 inhibition on OSCC was investigated in vivo by chaetocin treatment. The migration and tube formation of vascular endothelial cells by conditioned culture-medium of different treatments of oral squamous cell cells were measured. The transcriptional level of SUV39H1 is elevated in various cancer tissues. The transcription level of SUV39H1 in head and neck squamous cell carcinoma was significantly higher than that in control. Immunohistochemistry result showed increased SUV39H1 expression in OSCC, which was significantly correlated with T staging. The expression of SUV39H1 was significantly correlated with Notch1 and CD31. In vivo experiment chaetocin treatment significantly inhibit the growth of tumor, and reduce SUV39H1, Notch1, CD31 expression. The decreased expression of SUV39H1 in OSCC cells lead to the decreased expression of Notch1 and VEGF proteins, as well as the decreased migration and tube formation ability of vascular endothelial cells. Inhibition of Notch1 further enhance this effect. Our results suggest inhibition of SUV39H1 may affect angiogenesis by regulating Notch1 expression. This study provides a foundation for SUV39H1 as a potential therapeutic target for OSCC.

Oxyberberine sensitizes liver cancer cells to sorafenib via inhibiting NOTCH1-USP7-c-Myc pathway.

BACKGROUND: Sorafenib is the first-line therapy for patients with advanced-stage HCC, but its clinical cure rate is unsatisfactory due to adverse reactions and drug resistance. Novel alternative strategies to overcome sorafenib resistance are urgently needed. Oxyberberine (OBB), a major metabolite of berberine in vivo, exhibits potential antitumor potency in various human malignancies, including liver cancer. However, it remains unknown whether and how OBB sensitizes liver cancer cells to sorafenib. METHODS: Cell viability, trypan blue staining and flow cytometry assays were employed to determine the synergistic effect of OBB and sorafenib on killing HCC cells. PCR, western blot, co-immunoprecipitation and RNA interference assays were used to decipher the mechanism by which OBB sensitizes sorafenib. HCC xenograft models and clinical HCC samples were utilized to consolidate our findings. RESULTS: We found for the first time that OBB sensitized liver cancer cells to sorafenib, enhancing its inhibitory effect on cell growth and induction of apoptosis in vitro. Interestingly, we observed that OBB enhanced the sensitivity of HCC cells to sorafenib by reducing ubiquitin-specific peptidase 7 (USP7) expression, a well-known tumor-promoting gene. Mechanistically, OBB inhibited notch homolog 1-mediated USP7 transcription, leading to the downregulation of V-Myc avian myelocytomatosis viral oncogene homolog (c-Myc), which synergized with sorafenib to suppress liver cancer. Furthermore, animal results showed that cotreatment with OBB and sorafenib significantly inhibited the tumor growth of liver cancer xenografts in mice. CONCLUSIONS: These results indicate that OBB enhances the sensitivity of liver cancer cells to sorafenib through inhibiting notch homolog 1-USP7-c-Myc signaling pathway, which potentially provides a novel therapeutic strategy for liver cancer to improve the effectiveness of sorafenib.

Hypoxia preconditioning increases Notch1 activity by regulating DNA methylation in vitro and in vivo.

BACKGROUND: Our previous research has demonstrated that hypoxic preconditioning (HPC) can improve spatial learning and memory abilities in adult mice. Adult hippocampal neurogenesis has been associated with learning and memory. The Neurogenic locus notch homolog protein (Notch) was involved in adult hippocampal neurogenesis, as well as in learning and memory. It is currently unclear whether the Notch pathway regulates hippocampal neuroregeneration by modifying the DNA methylation status of the Notch gene following HPC. METHOD: The HPC animal model and cell model were established through repeated hypoxia exposure using mice and the mouse hippocampal neuronal cell line HT22. Step-down test was conducted on HPC mice. Real-time PCR and Western blot analysis were used to assess the mRNA and protein expression levels of Notch1 and hairy and enhancer of split1 (HES1). The presence of BrdU-positive cells and Notch1 expression in the hippocampal dental gyrus (DG) were examined with confocal microscopy. The methylation status of the Notch1 was analyzed using methylation-specific PCR (MS-PCR). HT22 cells were employed to elucidate the impact of HPC on Notch1 in vitro. RESULTS: HPC significantly improved the step-down test performance of mice with elevated levels of mRNA and protein expression of Notch1 and HES1 (P < 0.05). The intensities of the Notch1 signal in the control group, the H group and the HPC group were 2.62 ± 0.57 × 107, 2.87 ± 0.84 × 107, and 3.32 ± 0.14 × 107, respectively, and the number of BrdU (+) cells in the hippocampal DG were 1.83 ± 0.54, 3.71 ± 0.64, and 7.29 ± 0.68 respectively. Compared with that in C and H group, the intensity of the Notch1 signal and the number of BrdU (+) cells increased significantly in HPC group (P < 0.05). The methylation levels of the Notch1 promoter 0.82 ± 0.03, 0.65 ± 0.03, and 0.60 ± 0.02 in the C, H, and HPC groups, respectively. The methylation levels of Notch1 decreased significantly (P < 0.05). The effect of HPC on HT22 cells exhibited similarities to that observed in the hippocampus. CONCLUSION: HPC may confer neuroprotection by activating the Notch1 signaling pathway and regulating its methylation level, resulting in the regeneration of hippocampal neurons.

Inhibition of Notch1 signal promotes brain recovery by modulating glial activity after stroke.

BACKGROUND: Notch1 signaling inhibiton with N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester] (DAPT) treatment could promote brain recovery and the intervention effect is different between striatum (STR) and cortex (CTX), which might be accounted for different changes of glial activities, but the in-depth mechanism is still unknown. The purpose of this study was to identify whether DAPT could modulate microglial subtype shifts and astroglial-endfeet aquaporin-4 (AQP4) mediated waste solute drainage. METHODS: Sprague-Dawley rats (n=10) were subjected to 90min of middle cerebral artery occlusion (MCAO) and were treated with DAPT (n=5) or act as control with no treatment (n=5). Two groups of rats underwent MRI scans at 24h and 4 week, and sacrificed at 4 week after stroke for immunofluorescence (IF). RESULTS: Compared with control rats, MRI data showed structural recovery in ipsilateral STR but not CTX. And IF showed decreased pro-inflammatory M1 microglia and increased anti-inflammatory M2 microglia in striatal lesion core and peri-lesions of STR, CTX. Meanwhile, IF showed decreased AQP4 polarity in ischemic brain tissue, however, AQP4 polarity in striatal peri-lesions of DAPT treated rats was higher than that in control rats but shows no difference in cortical peri-lesions between control and treated rats. CONCLUSIONS: The present study indicated that DAPT could promote protective microglia subtype shift and striatal astrocyte mediated waste solute drainage, that the later might be the major contributor of waste solute metabolism and one of the accounts for discrepant recovery of STR and CTX.

The ADAM17 inhibitor ZLDI-8 sensitized hepatocellular carcinoma cells to sorafenib through Notch1-integrin ß-talk.

ZLDI-8 is an A disintegrin and metalloproteinase domain 17 (ADAM17) inhibitor that suppresses the shedding of Notch1 to the Notch1 intracellular domain (NICD). In previous studies, we found that ZLDI-8 was able to sensitize HCC to sorafenib, but the mechanism of action remains unclear. The sensitizing effects of ZLDI-8 were tested both in vitro and in vivo. EMT-related factors, sorafenib sensitivity-related proteins and ECM-related gene expression were assessed using immunohistochemistry, RTPCR and Western blotting. Knockdown assays were conducted to determine the relationship between the Notch and Integrin pathways. CoIP assays, nuclear and cytoplasmic fractionation and immunofluorescence colocalization were applied to explore the interaction between the Notch and Integrin pathways. Appropriate statistical analysis methods were used to assess the significance of the experimental results and to ensure the scientific validity and reliability of the experimental design. We found that ECM- and EMT-related proteins were downregulated after ZLDI-8 treatment (P<0.05). ZLDI-8 significantly downregulated Integrinß1 and Integrinß3 in HCC in vitro and in vivo (P<0.05), possibly through Foxc2-dependent regulation. Mechanistically, interfering with the expression of both Integrin-linked kinase (ILK) and the NICD may downregulate the expression of proteins targeted by sorafenib, thereby sensitizing cells to sorafenib. The retroregulation of Integrinß by ILK may occur through the interaction between the NICD and ILK and may be the result of the translocation of the complexus. Our study indicates that blocking the Notch pathway may affect Integrinß through crosstalk between the Notch1 and Integrinß/ILK signaling pathways, thus providing a potential therapeutic strategy for HCC.

Upregulation of Notch Signaling and Cell-Differentiation Inhibitory Transcription Factors in Stable Chronic Obstructive Pulmonary Disease Patients.

Notch signaling is involved in the prevention of cell differentiation and cell fate in various organs, including the lungs. We aimed to determine the transcriptomic and protein expression of Notch receptors, their ligands, and related transcription factors in stable COPD. The expression and localization of Notch receptors, their ligands, and related transcription factors were measured in bronchial biopsies of individuals with stable mild/moderate (MCOPD) (n = 18) or severe/very severe (SCOPD) (n = 16) COPD, control smokers (CSs) (n = 13), and control nonsmokers (CNSs) (n = 11), and in the lung parenchyma of those with MCOPD (n = 13), CSs (n = 10), and CNSs (n = 10) using immunohistochemistry, ELISA tests, and transcriptome analyses. In the bronchial biopsies, Notch4 and HES7 significantly increased in the lamina propria of those with SCOPD compared to those with MCOPD, CSs, and CNSs. In the peripheral lung bronchiolar epithelium, Notch1 significantly increased in those with MCOPD and CSs compared to CNSs. ELISA tests of lung parenchyma homogenates showed significantly increased Notch2 in those with MCOPD compared to CSs and CNSs. Transcriptomic data in lung parenchyma showed increased DLL4 and HES1 mRNA levels in those with MCOPD and CSs compared to CNSs. These data show the increased expression of the Notch pathway in the lungs of those with stable COPD. These alterations may play a role in impairing the regenerative-reparative responses of diseased bronchioles and lung parenchyma.

NOTCH1-Related Leukoencephalopathy: A Novel Variant and Literature Review.

NOTCH1-related leukoencephalopathy is a new diagnostic entity linked to heterozygous gain-of-function variants in NOTCH1 that neuroradiologically show some overlap with the inflammatory microangiopathy Aicardi-Goutières syndrome (AGS). To report a 16-year-old boy harbouring a novel NOTCH1 mutation who presented neuroradiological features suggestive of enhanced type I interferon signalling. We describe five years of follow-up and review the current literature on NOTCH1-related leukoencephalopathy. Clinical evaluation, standardised scales (SPRS, SARA, CBCL, CDI-2:P, WISCH-IV and VABS-2) and neuroradiological studies were performed, as well as blood DNA analysis. For the literature review, a search was performed on Pubmed, Scopus and Web of Science up to December 2023 using the following text word search strategy: (NOTCH1) AND (leukoencephalopathy). Our patient presents clinical features consistent with other reported cases with NOTCH1 mutations but is among the minority of patients with an onset after infancy. During the five-year follow-up, we observed an increase in the severity of spasticity and ataxia. However, at the age of 16 years, our proband is still ambulatory. As for other reported patients, he manifests psychiatric features ranging from hyperactivity during childhood to anxiety and depression during adolescence. The neuroradiological picture remained essentially stable over five years. In addition to the typical findings of leukoencephalopathy with cysts and calcifications already described, we report the presence of T2-hyperintensity and T1-hypotensity of the transverse pontine fibres, enhancement in the periventricular white matter after gadolinium administration and decreased NAA and Cho peaks in the periventricular white matter on MRS. We identified a novel heterozygous variant in NOTCH1 (c.4788_4799dup), a frame insertion located in extracellular negative regulatory region (NRR)-domain as in previously published cases. Blood interferon signalling was not elevated compared to controls. This case provides further data on a new diagnostic entity, i.e., NOTCH1-related leukoencephalopathy. By describing a standardised five-year follow-up in one case and reviewing the other patients described to date, we outline recommendations relating to monitoring in this illness, emphasising the importance of psychiatric and gastroenterological surveillance alongside neurological and neuropsychological management. Studies are needed to better understand the factors influencing disease onset and severity, which are heterogeneous.

Efficient Escorting Strategy for Aggregation-Prone Notch EGF Repeats with Sparcl1.

Epidermal growth factor (EGF) repeats are present in various proteins and form well-defined structures with three disulfide bonds. One representative protein is the Notch receptor. Each EGF repeat contains unique atypical O-linked glycans, such as O-linked N-acetylglucosamine (O-GlcNAc). To generate a monoclonal antibody against the O-GlcNAc moiety in mouse Notch1, we expressed the recombinant C-terminal His6-tagged Notch1 EGF14-15 protein in HEK293T cells to prepare the immunogen. Most of the proteins were not secreted and showed higher molecular weight ladders in the cell lysate, suggesting protein aggregation. To overcome this issue, we fused Sparcl1 as an extracellular escorting tag to the N-terminus of Notch1 EGF14-15. The fusion protein was efficiently secreted extracellularly without protein aggregates in the lysates. Following PreScission protease treatment, Notch1 EGF14-15 was efficiently released from the escorting tag. Notch1 EGF14-15 prepared using this method was indeed O-GlcNAcylated. The optimal length of the escorting tag was determined by generating deletion mutants to improve the extracellular secretion of EGF14-15. Hence, a large amount of EGF14-15 was successfully prepared from the culture supernatant of HEK293T cells, which were otherwise prone to aggregation.