Jag1 insufficiency alters liver fibrosis via T cell and hepatocyte differentiation defects.

Fibrosis contributes to tissue repair, but excessive fibrosis disrupts organ function. Alagille syndrome (ALGS, caused by mutations in JAGGED1) results in liver disease and characteristic fibrosis. Here, we show that Jag1Ndr/Ndr mice, a model for ALGS, recapitulate ALGS-like fibrosis. Single-cell RNA-seq and multi-color flow cytometry of the liver revealed immature hepatocytes and paradoxically low intrahepatic T cell infiltration despite cholestasis in Jag1Ndr/Ndr mice. Thymic and splenic regulatory T cells (Tregs) were enriched and Jag1Ndr/Ndr lymphocyte immune and fibrotic capacity was tested with adoptive transfer into Rag1-/- mice, challenged with dextran sulfate sodium (DSS) or bile duct ligation (BDL). Transplanted Jag1Ndr/Ndr lymphocytes were less inflammatory with fewer activated T cells than Jag1+/+ lymphocytes in response to DSS. Cholestasis induced by BDL in Rag1-/- mice with Jag1Ndr/Ndr lymphocytes resulted in periportal Treg accumulation and three-fold less periportal fibrosis than in Rag1-/- mice with Jag1+/+ lymphocytes. Finally, the Jag1Ndr/Ndr hepatocyte expression profile and Treg overrepresentation were corroborated in patients' liver samples. Jag1-dependent hepatic and immune defects thus interact to determine the fibrotic process in ALGS.

Delivery of a Jagged1-PEG-MAL hydrogel with pediatric human bone cells regenerates critically sized craniofacial bone defects.

Current treatments for congenital and acquired craniofacial (CF) bone abnormalities are limited and costly. Conventional methods involve surgical correction, short-term stabilization, and long-term bone grafting, which may include problematic allografts and limited autografts. While bone morphogenetic protein 2 (BMP2) has been used for bone regeneration, it can cause bone overgrowth and life-threatening inflammation. Bone marrow-derived mesenchymal stem cell therapies, though promising, are not Food and Drug Administration approved and are resource intensive. Thus, there is a need for effective, affordable, and less side-effect-prone bone regenerative therapies. Previous research demonstrated that JAGGED1 induces osteoblast commitment in murine cranial neural crest cells through a NOTCH-dependent non-canonical pathway involving JAK2-STAT5. We hypothesize that delivery of JAGGED1 and induction of its downstream NOTCH non-canonical signaling in pediatric human osteoblasts constitutes an effective bone regenerative treatment. Delivering pediatric human bone-derived osteoblast-like cells to an in vivo murine bone loss model of a critically sized cranial defect, we identified that JAGGED1 promotes human pediatric osteoblast commitment and bone formation through p70 S6K phosphorylation. This approach highlights the potential of JAGGED1 and its downstream activators as innovative treatments for pediatric CF bone loss.

SOX2, JAGGED1, ß-Catenin, and Vitamin D Receptor Expression Patterns during Early Development and Innervation of the Human Inner Ear.

Sensorineural hearing loss can be caused by lesions to the inner ear during development. Understanding the events and signaling pathways that drive inner ear formation is crucial for determining the possible causes of congenital hearing loss. We have analyzed the innervation and expression of SOX2, JAGGED1, ß-catenin (CTNNB1), and vitamin D receptor (VDR) in the inner ears of human conceptuses aged 5 to 10 weeks after fertilization (W) using immunohistochemistry. The prosensory domains of the human inner ear displayed SOX2 and JAGGED1 expression throughout the analyzed period, with SOX2 expression being more extensive in all the analyzed timepoints. Innervation of vestibular prosensory domains was present at 6 W and extensive at 10 W, while nerve fibers reached the base of the cochlear prosensory domain at 7-8 W. CTNNB1 and VDR expression was mostly membranous and present during all analyzed timepoints in the inner ear, being the strongest in the non-sensory epithelium. Their expression was stronger in the vestibular region compared to the cochlear duct. CTNNB1 and VDR expression displayed opposite expression trends during the analyzed period, but additional studies are needed to elucidate whether they interact during inner ear development.

CircVCAN promotes glioma progression through the miR-488-3p/MEF2C-JAGGED1 axis.

Gliomas are the most prevalent primary malignant brain tumors worldwide. Growing evidences indicate that circular RNAs (circRNAs) play an important role in the regulation of biological behavior of tumors. We aimed to investigate the role and mechanism of circVCAN in glioma. RNase R treatment was utilized to assess the cyclic properties of circVCAN. CircVCAN, miR-488-3p, and myocyte enhancer factor 2C (MEF2C) levels in glioma tissues and cells were detected by reverse transcription real-time polymerase chain reaction (RT-qPCR), and the localization of them in glioma cells was determined with fluorescence in situ hybridization. Furthermore, a variety of biologically functional assessments were used to validate the role of circVCAN in glioma. The regulatory mechanisms of circVCAN, miR-488-3p, and MEF2C were further confirmed by double luciferase reporter gene assay, RNA immunoprecipitation and RNA pull-down assay, and the binding of MEF2C to JAGGED1 was revealed by chromatin immunoprecipitation. Additionally, a xenograft tumor model was constructed to demonstrate the effect of circVCAN on tumor growth in vivo. Our results indicated that circVCAN was more stable than its linear RNA and was significantly upregulated in gliomas. CircVCAN overexpression stimulated glioma cells to proliferate and metastasize, but circVCAN silencing exerted the opposite effect. Meanwhile, silencing circVCAN inhibited tumor growth in vivo. Moreover, we found that circVCAN interacted with miR-488-3p to regulate MEF2C expression, and miR-488-3p inhibition or MEF2C overexpression reversed the inhibitory effect on malignant bio-behaviors mediated by circVCAN knockdown in glioma cells. MEF2C promoted the transcription of JAGGED1, and circVCAN knockdown reduced the binding between MEF2C and JAGGED1. Collectively, circVCAN is a carcinogenic circRNA in glioma, and the circVCAN/miR-488-3p/MEF2C-JAGGED1 axis could serve as a potential target for the management of glioma.

Familial exudative vitreoretinopathy (FEVR) in a child with a Jagged 1 variant identified on genetic testing.

INTRODUCTION: Familial Exudative Vitreoretinopathy (FEVR) is a heritable retinal vascular disease characterized by incomplete vascularization of the peripheral retina resulting in ischemia. Fifty percent of FEVR cases 10 are due to known pathogenic genetic variants, and disease phenotype can vary greatly. FEVR is a clinical diagnosis, however, genetic testing can play a key role in screening for FEVR in genetically susceptible populations, thus leading to early treatment and improved patient outcomes. CASE: A 2-year-old male with no known past ocular or medical history was diagnosed with FEVR upon examination under anesthesia and multimodal retinal imaging. Genetic testing identified a Jagged 1 (JAG1) variant of uncertain significance, 15 which has been linked to FEVR in recent studies. Despite close follow-up and treatment, the patient experienced a funnel retinal detachment in the right eye approximately one year after diagnosis. DISCUSSION: This case in conjunction with recent literature suggests that JAG1 variants are likely associated with FEVR. Further investigations are necessary to identify the frequency of JAG1 variants among patients with FEVR. Robust understanding of FEVR's heterogenous genetic profile will lead to improved treatment modalities 20 and patient outcomes.

Jagged1-Notch1 Signaling Pathway Induces M1 Microglia to Disrupt the Barrier Function of Retinal Microvascular Endothelial Cells.

PURPOSE: Microglia-related inflammation is closely linked to the pathogenesis of retinal diseases. The primary objective of this research was to investigate the impact and mechanism of M1 phenotype microglia on the barrier function of retina microvascular endothelial cells. METHODS: Quantitative polymerase chain reactions and western blot techniques were utilized to analysis the mRNA and protein expressions of M1 and M2 markers of human microglial clone 3 cell line (HMC3), as well as the levels of Notch ligands and receptors under the intervention of lipopolysaccharide (LPS) or interleukin (IL)-4. ELISA was utilized to detect the pro-inflammatory and anti-inflammatory cytokines from HMC3 cells. The cellular tight junction and apoptosis of human retinal microvascular endothelial cells (HRMECs) were assessed by western blot and fluorescein isothiocyanate-dextran permeability assay. The inhibitors of Notch1 and RNA interference (RNAi) targeting Jagged1 were used to assess their contribution to the barrier function of vascular endothelial cells. RESULTS: Inducible nitric oxide synthase (iNOS) and IL-1ß were considerably elevated in LPS-treated HMC3, while CD206 and Arg-1 markedly elevated under IL-4 stimulation. The conditioned medium derived from LPS-treated HMC3 cells promoted permeability, diminished the expression of zonula occludens-1 and Occludin, and elevated the expression of Cleaved caspase-3 in HRMECs. RNAi targeting Jagged1 or Notch1 inhibitor could block M1 HMC3 polarization and maintain barrier function of HRMECs. CONCLUSION: Our findings suggest that Jagged1-Notch1 signaling pathway induces M1 microglial cells to disrupt the barrier function of HRMECs, which may lead to retinal diseases.

Sacubitril/valsartan inhibits the proliferation of vascular smooth muscle cells through notch signaling and ERK1/2 pathway.

AIMS: To explore the role and mechanism of Notch signaling and ERK1/2 pathway in the inhibitory effect of sacubitril/valsartan on the proliferation of vascular smooth muscle cells (VSMCs). MAIN METHODS: Human aortic vascular smooth muscle cells (HA-VSMCs) were cultured in vitro. The proliferating VSMCs were divided into three groups as control group, Ang II group and Ang II + sacubitril/valsartan group. Cell proliferation and migration were detected by CCK8 and scratch test respectively. The mRNA and protein expression of PCNA, MMP-9, Notch1 and Jagged-1 were detected by qRT-PCR and Western blot respectively. The p-ERK1/2 expression was detected by Western blot. KEY FINDINGS: Compared with the control group, proliferation and migration of VSMCs and the expression of PCNA, MMP-9, Notch1, Jagged-1 and p-ERK1/2 was increased in Ang II group. Sacubitril/valsartan significantly reduced the proliferation and migration. Additionally, pretreatment with sacubitril/valsartan reduced the PCNA, MMP-9, Notch1, Jagged-1 and p-ERK1/2 expression.

Modulating Th1/Th2 drift in asthma-related immune inflammation by enhancing bone mesenchymal stem cell homing through targeted inhibition of the Notch1/Jagged1 signaling pathway.

Asthma, a disease intricately linked to immune inflammation, is significantly influenced by the immune regulatory effect of bone mesenchymal stem cells (BMSCs). This study aims to investigate changes in the homing of BMSCs in bronchial asthma, focusing on the Notch homolog (Notch)1/Jagged1 signaling pathway's role in regulating T helper 1(Th1)/T helper 2(Th2) drift. Additionally, we further explore the effects and mechanisms of homologous BMSCs implantation in asthma-related immune inflammation. Following intervention with BMSCs, a significant improvement in the pathology of rats with asthma was observed. Simultaneously, a reduction in the expression of inflammatory cells and inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin(IL)-4, and IL-13 was observed in bronchoalveolar lavage fluid (BALF). Furthermore, there was an increase in the expression of Th1 cytokine Interferon-γ（IFN-γ）and the transcription factor T-box expressed in T cell (T-bet), while the expression of Th2 cytokine IL-13 and transcription factor GATA binding protein (GATA)-3 decreased in lung tissue. This indicates that the Th1/Th2 drift leans towards Th1, which a crucial in ameliorating asthma inflammation. Importantly, inhibition of the Notch1 signaling pathway led to an increased expression of the Stromal cell-derived factor-1(SDF-1)/C-X-C motif chemokine receptor (CXCR)4 chemokine axis. Consequently, the homing ability of bone marrow mesenchymal stem cells to asthma-affected lung tissue was significantly enhanced. BMSCs demonstrated heightened efficacy in regulating the cytokine/chemokine network and Th1/Th2 balance, thereby restoring a stable state during the immune response process in asthma. In conclusion, inhibiting the Notch signaling pathway enhances the expression of the SDF-1 and CXCR4 chemokine axis, facilitating the migration of allogeneic BMSCs to injured lung tissues. This, in turn, promotes immune regulation and improves the Th1/Th2 imbalance, thereby enhancing the therapeutic effect on asthmatic airway inflammation.

ß-cell Jagged1 is sufficient but not necessary for islet Notch activity and insulin secretory defects in obese mice.

OBJECTIVE: Notch signaling, re-activated in ß cells from obese mice and causal to ß cell dysfunction, is determined in part by transmembrane ligand availability in a neighboring cell. We hypothesized that ß cell expression of Jagged1 determines the maladaptive Notch response and resultant insulin secretory defects in obese mice. METHODS: We assessed expression of Notch pathway components in high-fat diet-fed (HFD) or leptin receptor-deficient (db/db) mice, and performed single-cell RNA sequencing (scRNA-Seq) in islets from patients with and without type 2 diabetes (T2D). We generated and performed glucose tolerance testing in inducible, ß cell-specific Jagged1 gain-of- and loss-of-function mice. We also tested effects of monoclonal neutralizing antibodies to Jagged1 in glucose-stimulated insulin secretion (GSIS) assays in isolated islets. RESULTS: Jag1 was the only Notch ligand that tracked with increased Notch activity in HFD-fed and db/db mice, as well as in metabolically-inflexible ß cells enriched in patients with T2D. Neutralizing antibodies to block Jagged1 in islets isolated from HFD-fed and db/db mice potentiated GSIS ex vivo. To demonstrate if ß cell Jagged1 is sufficient to cause glucose tolerance in vivo, we generated inducible ß cell-specific Jag1 transgenic (ß-Jag1TG) and loss-of-function (iß-Jag1KO) mice. While forced Jagged1 impaired glucose intolerance due to reduced GSIS, loss of ß cell Jagged1 did not protect against HFD-induced insulin secretory defects. CONCLUSIONS: Jagged1 is increased in islets from obese mice and in patients with T2D, and neutralizing Jagged1 antibodies lead to improved GSIS, suggesting that inhibition of Jagged1-Notch signaling may have therapeutic benefit. However, genetic loss-of-function experiments suggest that ß cells are not a likely source of the Jagged1 signal.

Notch signaling regulates mineralization via microRNA modulation in dental pulp stem cells.

OBJECTIVES: This study investigated the miRNA expression profile in Notch-activated human dental stem pulp stem cells (DPSCs) and validated the functions of miRNAs in modulating the odonto/osteogenic properties of DPSCs. METHODS: DPSCs were treated with indirect immobilized Jagged1. The miRNA expression profile was examined using NanoString analysis. Bioinformatic analysis was performed, and miRNA expression was validated. Odonto/osteogenic differentiation was examined using alkaline phosphatase staining, Alizarin Red S staining, as well as odonto/osteogenic-related gene and protein expression. RESULTS: Fourteen miRNAs were differentially expressed in Jagged1-treated DPSCs. Pathway analysis revealed that altered miRNAs were associated with TGF-ß, Hippo, ErbB signalling pathways, FoxO and Ras signalling. Target prediction analysis demonstrated that 7604 genes were predicted to be targets for these altered miRNAs. Enrichment analysis revealed relationships to various DNA bindings. Among differentially expressed miRNA, miR-296-3p and miR-450b-5p were upregulated under Jagged1-treated conditions. Overexpression of miR-296-3p and miR-450b-5p enhanced mineralization and upregulation of odonto/osteogenic-related genes, whereas inhibition of these miRNAs revealed opposing results. The miR-296-3p and miR-450b-5p inhibitors attenuated the effects of Jagged1-induced mineralization in DPSCs. CONCLUSIONS: Jagged-1 promotes mineralization in DPSCs that are partially regulated by miRNA. The novel understanding of these miRNAs could lead to innovative controlled mechanisms that can be applied to modulate biology-targeted dental materials.

The Jagged-1/Notch1 Signaling Pathway Promotes the Construction of Tissue-Engineered Heart Valves.

Background: Tissue-engineered heart valves (TEHVs) are promising new heart valve substitutes for valvular heart disease. The Notch signaling pathway plays a critical role in the development of congenital heart valves. Objective: To investigate the role of the Notch signaling pathway in the construction of TEHVs. Methods: The induced endothelial cells, which act as seed cells, were differentiated from adipose-derived stem cells and were treated with Jagged-1 (JAG-1) protein and γ-secretase inhibitor (DAPT, N-[N-(3,5-difluorophenacetyl)-l-alanyl]-s-phenylglycine t-butyl ester), respectively. Cell phenotypic changes, the expression of proteins relating to the epithelial-mesenchymal transition (EMT), and changes in paxillin expression were detected. Decellularized valve scaffolds were produced from decellularized porcine aortic valves. The seed cells were them inoculated into Matrigel-coated flap scaffolds for complex culture and characterization. Results: JAG-1 significantly reduced apoptosis and promoted the seeded cells' proliferation and migration ability, in contrast to the treatment of DAPT. In addition, the expression of EMT-related proteins, E-cadherin and N-cadherin, was significantly increased after treatment with JAG-1 and was reduced after the application of DAPT. Meanwhile, the adhesive-related expression of paxillin and fibronectin proteins was increased after the activation of Notch1 signaling and vice versa. Of interest, activation of the Notch1 signaling pathway resulted in more closely arranged cells on the valve surface after recellularization. Conclusion: Activation of the JAG-1/Notch1 signaling pathway increased seeded cells' proliferation and migratory ability and promoted the EMT and adhesion of seed cells, which was conducive to binding to the matrix, facilitating accelerated endothelialization of TEHVs.

Bruceine D suppresses CAF-promoted TNBC metastasis under TNF-α stimulation by inhibiting Notch1-Jagged1/NF-κB(p65) signaling.

BACKGROUND: Triple-negative breast cancer (TNBC) has a poor prognosis because of its high degree of malignancy and the lack of effective treatment options. Cancer-associated fibroblasts (CAFs) comprise the most abundant stromal cells in the tumor microenvironment (TME), leading to functional impairments and facilitating tumor metastasis. Excessive TNF-α further promotes cross-talk between different cells in TME. Therefore, there is an urgent need to develop more effective therapies and potential drugs that target the key factors that promote TNBC metastasis. PURPOSE: The study aimed to evaluate the efficacy of Bruceine D, an active compound derived from the Chinese herb Brucea javanica, in inhibiting metastasis and elucidate the underlying mechanism of action in TNBC. METHODS: In vitro, the clonogenic and the Transwell assays were used to assess the effects of Bruceine D on the proliferation, migration and invasion abilities of co-cultured CAFs and MDA-MB-231 (4T1) cells under TNF-α stimulation. TNF-α, IL-6, CXCL12, TGF-ß1, and MMP9 levels in the supernatant of co-cultured cells were determined using ELISA. Western blotting was utilized to detect the expression levels of proteins related to the Notch1-Jagged1/NF-κB(p65) pathway. In vivo, the anti-tumor growth and anti-metastatic effectiveness of Bruceine D was evaluated by determining tumor weight, number of metastatic lesions, and pathological changes in the tumor and lung/liver tissues. The inhibitory effect of Bruceine D on α-SMA+ CAFs activation and CAF-medicated extracellular matrix remodeling was accessed using immunohistochemistry, immunofluorescence, and Masson and Sirius Red staining. The expression levels of Notch1, Jagged1 and p-NF-κB(p65) proteins in the primary tumors were measured by immunohistochemistry and western blotting. RESULTS: In vitro, Bruceine D significantly inhibited the migration and invasion of co-cultured CAFs and MDA-MB-231 (4T1) cells under TNF-α stimulation, reduced the expression of tumor-promoting and matrix-remodeling cytokines secreted by CAFs, and hindered the mutual activation of Notch1-Jagged1 and NF-κB(p65). In vivo, Bruceine D significantly suppressed tumor growth and the formation of lung and liver metastases by decreasing TNF-α stimulated α-SMA+ CAFs activation, collagen fibers, MMPs production, and inhibited Notch1-Jagged1/NF-κB(p65) signaling in TNBC-bearing mice. CONCLUSION: Bruceine D effectively weakened the "tumor-CAF-inflammation" network by inhibiting the mutual activation of Notch1-Jagged1 and NF-κB(p65) and thereby suppressed TNBC metastasis. This study first explored that Bruceine D disrupted the cross-talk between CAFs and tumor cells under TNF-α stimulation to inhibit the metastasis of TNBC, and highlighted the potential of Bruceine D as therapeutic agent for suppressing tumor metastasis.

Cancer-associated fibroblasts-induced remodeling of tumor immune microenvironment via Jagged1 in glioma.

Tumor immunosuppression are prominent characteristics of brain glioma. Current standard modality including surgical resection and chemoradiotherapy do not significantly improve clinical outcomes. Cancer-associated fibroblasts (CAFs) that regard as important stromal cells in tumor microenvironment have been confirmed to play crucial roles in tumor development. However, the effects of CAFs on tumor immunosuppression in glioma are not well expounded. In this study, we report that CAFs contributes to the formation of glioma immunosuppressive microenvironment. Specifically, we found that glioma-derived Jagged1 enhanced the proliferation and PD-L1 expression of CAFs in vitro. Importantly, we discovered that Notch1, c-Myc and PD-L1 expression were significantly increased in high Jagged1-expressing gliomas, moreover, we further confirmed that Notch1 and PD-L1 expression located on the CAFs in glioma tissues. We also found that glioma-derived Jagged1 promotes the increase of tumor-infiltrating macrophages, M2 macrophages and Foxp3 Treg cells, as well as no significance of M1 macrophages and CD8+ T cells, indicating potential immunosuppression. This study opens up novel therapeutic strategies reversing CAF immunosuppression for gliomas.

[High homocysteine level promotes autophagy and apoptosis of mouse hippocampal HT22 cells through the Notch1/Hes1 signaling pathway].

OBJECTIVE: To explore the mechanism of neuronal injury caused by hyperhomocysteinemia. METHODS: Mouse hippocampal HT22 cells were treated with homocysteine (Hcy, 100 µmol/L), Hcy+folic acid+vitamin B12 (100+fv group) or folic acid+vitamin B12 (0+fv group), and the changes in cell autophagy and apoptosis were detected using transmission electron microscope (TEM) and flow cytometry. The expressions of Hes1, Hes5, Notch1, Jagged1, Bcl-2, Bax, P62 and LC3 in the treated cells were detected with Western blotting and real-time PCR. RESULTS: Treatment with Hcy for 48 h significantly increased the number of dead cells in HT22 cell cultures. Flow cytometry showed that the percentage of apoptotic cells was significantly higher in cells treated with Hcy alone than in other treatment groups (P<0.05). TEM revealed obvious mitochondrial swelling and vacuolation and increased autophagy in Hcy-treated cells. Western blotting showed that the Bax/Bcl-2 ratio was significantly higher in Hcy-treated cells than in the blank control cells and cells in 100+fv group (P<0.05). The Hcy-treated cells showed a significantly lower relative expression of P62 than the blank control cells (P<0.05), a higher LC3II/LC3I ratio than the cells in the blank control and 100+fv groups (P<0.05), and lower expressions of HES1, HES5, Notch1 and Jagged1 proteins than the blank control cells (P<0.05). Interference with Hes1 siRNA significantly lowered the expression levels of Hes1 and Jagged1 without obviously affecting Notch1 expression in HT22 cells (P>0.05). CONCLUSION: High Hcy levels promote autophagy and apoptosis and down-regulate Hes1 and Jagged1 expressions in HT22 cells.

Delivery of A Jagged1-PEG-MAL hydrogel with Pediatric Human Bone Cells Regenerates Critically-Sized Craniofacial Bone Defects.

Treatments for congenital and acquired craniofacial (CF) bone abnormalities are limited and expensive. Current reconstructive methods include surgical correction of injuries, short-term bone stabilization, and long-term use of bone grafting solutions, including implantation of (i) allografts which are prone to implant failure or infection, (ii) autografts which are limited in supply. Current bone regenerative approaches have consistently relied on BMP-2 application with or without addition of stem cells. BMP2 treatment can lead to severe bony overgrowth or uncontrolled inflammation, which can accelerate further bone loss. Bone marrow-derived mesenchymal stem cell-based treatments, which do not have the side effects of BMP2, are not currently FDA approved, and are time and resource intensive. There is a critical need for novel bone regenerative therapies to treat CF bone loss that have minimal side effects, are easily available, and are affordable. In this study we investigated novel bone regenerative therapies downstream of JAGGED1 (JAG1). We previously demonstrated that JAG1 induces murine cranial neural crest (CNC) cells towards osteoblast commitment via a NOTCH non-canonical pathway involving JAK2-STAT5 (1) and that JAG1 delivery with CNC cells elicits bone regeneration in vivo. In this study, we hypothesized that delivery of JAG1 and induction of its downstream NOTCH non-canonical signaling in pediatric human osteoblasts constitute an effective bone regenerative treatment in an in vivo murine bone loss model of a critically-sized cranial defect. Using this CF defect model in vivo, we delivered JAG1 with pediatric human bone-derived osteoblast-like (HBO) cells to demonstrate the osteo-inductive properties of JAG1 in human cells and in vitro we utilized the HBO cells to identify the downstream non-canonical JAG1 signaling intermediates as effective bone regenerative treatments. In vitro, we identified an important mechanism by which JAG1 induces pediatric osteoblast commitment and bone formation involving the phosphorylation of p70 S6K. This discovery enables potential new treatment avenues involving the delivery of tethered JAG1 and the downstream activators of p70 S6K as powerful bone regenerative therapies in pediatric CF bone loss.

Biomedical engineering approaches for the delivery of JAGGED1 as a potential tissue regenerative therapy.

JAG1 is a ligand that activates the NOTCH signaling pathway which plays a crucial role in determining cell fate behavior through cell-to-cell signaling. JAG1-NOTCH signaling is required for mesenchymal stem cell (MSC) differentiation into cardiomyocytes and cranial neural crest (CNC) cells differentiation into osteoblasts, making it a regenerative candidate for clinical therapy to treat craniofacial bone loss and myocardial infarction. However, delivery of soluble JAG1 has been found to inhibit NOTCH signaling due to the requirement of JAG1 presentation in a bound form. For JAG1-NOTCH signaling to occur, JAG1 must be immobilized within a scaffold and the correct orientation between the NOTCH receptor and JAG1 must be achieved. The lack of clinically translatable JAG1 delivery methods has driven the exploration of alternative immobilization approaches. This review discusses the role of JAG1 in disease, the clinical role of JAG1 as a treatment, and summarizes current approaches for JAG1 delivery. An in-depth review was conducted on literature that used both in vivo and in vitro delivery models and observed the canonical versus non-canonical NOTCH pathway activated by JAG1. Studies were then compared and evaluated based on delivery success, functional outcomes, and translatability. Delivering JAG1 to harness its ability to control cell fate has the potential to serve as a therapeutic for many diseases.

Dendrobium officinale polysaccharide Converts M2 into M1 Subtype Macrophage Polarization via the STAT6/PPAR-r and JAGGED1/NOTCH1 Signaling Pathways to Inhibit Gastric Cancer.

Dendrobium officinale polysaccharide (DOP) has shown various biological activities. However, the ability of DOP to participate in immune regulation during anti-gastric cancer treatment has remained unclear. In this study, the in vitro results showed that DOP has the potential to polarize THP-1 macrophages from the M2 to the M1 phenotype, downregulate the STAT6/PPAR-r signaling pathway and the protein expression of their down-targeted ARG1 and TGM2, and further decrease the main protein and mRNA expression in the JAGGED1/NOTCH1 signaling pathway. DOP suppressed the migration of gastric cancer cells by decreasing the protein expression of N-cadherin and Vimentin and increasing E-cadherin. In addition, CM-DOP promoted the apoptosis of gastric cancer cells by upregulating Caspase-3 and increasing the ratio of Bax/Bcl-2. In vivo, DOP effectively inhibited the growth of tumors and the expression of Ki-67. In summary, these findings demonstrated that DOP converted the polarization of M2 subtype macrophages into M1 subtypes via the STAT6/PPAR-r and JAGGED1/NOTCH1 signaling pathways in order to reduce apoptosis and prevent migration, thus indicating the potential of DOP as an adjuvant tumor therapy in preclinical and clinical trials.

ZNF746 promotes M2 macrophage polarisation and favours tumour progression in breast cancer via the Jagged1/Notch pathway.

Breast cancer (BC) is a major threat to women's health. BC is a heterogeneous disease and treatment strategies and outcomes differ between subtypes. Investigating the molecular mechanisms of BC will help to identify potential therapeutic targets and develop new therapies. Here we report that zinc finger protein 746 (ZNF746), a Krüppel-associated box and zinc finger protein, exhibits tumour-promoting properties in BC. Functional experiments (cell growth, colony formation, cell cycle analysis, and transwell analysis) were used to evaluate the proliferation, migration, and invasion capacity of BC cells. Immunohistochemistry was performed to detect the expression of ZNF746, CD163 (M2 macrophage marker), and HES1 (Notch target) in BC tissues. ZNF746 was highly expressed in BC tissues compared to adjacent paired non-tumour tissues. Patients with M1 BC had higher expression of ZNF746 compared to patients with non-metastatic (M0) BC, and higher expression of ZNF746 was associated with poorer overall survival. The immunohistochemical results showed a positive correlation between the expression of ZNF746 and the expression of CD163 or HES1. ZNF746 promoted BC cell proliferation, migration, and invasion and increased the expression of molecules essential for monocyte recruitment and differentiation (CCL2 and CSF1). Furthermore, THP-1 monocytes cultured in the conditioned medium derived from BC cells overexpressing ZNF746 exhibited enhanced M2 polarisation. In contrast, ZNF746 knockdown reduced BC cell proliferation, migration, and invasion and suppressed M2 polarisation. Mechanistically, ZNF746 promoted the activation of the Jagged1/Notch pathway, and the Jagged1 siRNA-mediated blockade of this pathway prevented the tumour-promoting functions of ZNF746. In conclusion, this study uncovers the role of ZNF746 in promoting M2 macrophage polarisation and suggests that ZNF746 may be a promising therapeutic target for limiting BC progression.

Aberrant expression of PELI1 caused by Jagged1 accelerates the malignant phenotype of pancreatic cancer.

Pancreatic cancer is one of the most aggressive cancers. PELI1 has been reported to promote cell survival and proliferation in multiple cancers. As of now, the role of PELI1 in pancreatic cancer is largely unknown. Here, we found that the PELI1 mRNA was higher expressed in pancreatic tumor tissues than in adjacent normal tissues, and the high PELI1 level in pancreatic cancer patients had a short survival time compared with the low level. Moreover, the results showed that PELI1 promoted cell proliferation, migration, and invasion, and inhibited apoptosis in vitro. Xenograft tumor experiments were used to determine the biological function of PELI1, and the results showed that PELI1 promoted tumor growth in vivo. Additionally, we found that Jagged1 activated PELI1 transcription in pancreatic cancer cells. To sum up, our results show that PELI1 affects the malignant phenotype of pancreatic cancer.

Exosomes from hypoxia-conditioned apical papilla stem cells accelerate angiogenesis in vitro through Notch/JAG1/VEGF signaling.

Dental pulp angiogenesis is a committed step in pulp regeneration therapy, and exosomes provide a new cell-free choice for tissue regeneration. This study revealed the underlying regulatory mechanism of exosomes from stem cells of the apical papilla (SCAPs) under hypoxic state on angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro. Exosomes extracted from normoxia or hypoxia-pretreated SCAPs were co-cultured with HUVECs, and hypoxia pretreatment increased the release of exosomes and the internalization of exosomes by HUVECs. Compared to normoxic SCAPs-derived exosomes, exosomes from hypoxic SCAPs were found to promote cell proliferation and migration in HUVECs, as it was respectively determined by Cell Counting Kit-8, RT-qPCR and Transwell assay. Besides, hypoxia-educated SCAPs-exosomes especially enhanced the angiogenesis abilities of HUVECs in vitro, which were confirmed by tube formation assay and RT-qPCR detection of angiogenesis-related molecular markers. Interestingly, we found that the hypoxia inducible factor-1α (HIF-1α)/Notch1 signaling pathway was activated in hypoxic SCAPs, and protein jagged-1 (JAG1) was delivered by hypoxic SCAPs-derived exosomes to increase vascular endothelial growth factor (VEGF) production in HUVECs. Moreover, exogenous interference of JAG1 expression in HUVECs partially neutralized the activities of hypoxic SCAPs-exosomes in promoting cell proliferation, migration and tube formation of HUVECs. In summary, this study elucidates that exosomes from hypoxic SCAPs shows high potential to promote angiogenesis in vitro through the HIF-1α/JAG1/VEGF signaling cascade, which may provide a new perspective for the development of vascular reconstruction measures during dental regeneration engineering.