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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‐β, 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. [ABSTRACT FROM AUTHOR]

The Notch signalling pathway is widely present in organisms and is an essential factor involved in the developmental process. JAGGED-1, as an important ligand in the Notch signalling pathway, has been cloned from Exopalaemon carinicauda and its role in growth and development have been studied. The full length of the jagged-1 cDNA of E. carinicauda was 5148 bp encoding a protein composed of 1307 amino acids, which had the highest identity with JAGGED-1 of Procambarus clarkii. The expression of jagged-1 varied with development, with the highest expression at the gastrula stage of embryonic development, the Z2 stage of larval development, and the G4 stage of ovary development, respectively. The expression of jagged-1 in the interference group was significantly lower than that in the control group between 3 and 72 h post jagged-1 RNA interference. The expression of key genes in the Notch signalling pathway, including notch1 and delta , and genes related to growth and development, including chh , gih and mih , decreased significantly post jagged-1 RNA interference. After continuous jagged-1 RNA interference, the ovary of the interference group only developed to the G3 stage, while the ovary of the control group developed to the G4 stage. Further study found that there were 8 SNPs including one missense mutation (SNP 2389 T > C) and seven synonymous mutations, and the SNP 2389 T > C and SNP 2799 G > C might be related to the growth of E. carinicauda. The results showed that jagged-1 was involved in the growth and development of E. carinicauda. [ABSTRACT FROM AUTHOR]

Introduction: The Notch intracellular domain (NICD) and its ligands Jagged-1 (Jag1), Delta-like ligand (DLL-3) and DLL4 play an important role in neoangiogenesis. Previous studies suggest a correlation between the tissue levels of NICD and response to therapy with bevacizumab in colorectal cancer (CRC). Another marker that may predict outcome in CRC is radiomics of liver metastases. The aim of this study was to investigate the expression of NICD and its ligands and the role of radiomics in the selection of treatment-naive metastatic CRC patients receiving bevacizumab. Methods: Immunohistochemistry (IHC) for NICD, Jag1 and E-cadherin was performed on the tissue microarrays (TMAs) of 111 patients with metastatic CRC treated with bevacizumab and chemotherapy. Both the intensity and the percentage of stained cells were evaluated. The absolute number of CD4+ and CD8+ lymphocytes was counted in three different high-power fields and the mean values obtained were used to determine the CD4/CD8 ratio. The positivity of tumor cells to DLL3 and DLL4 was studied. The microvascular density (MVD) was assessed in fifteen cases by counting the microvessels at 20x magnification and expressed as MVD score. Abdominal CT scans were retrieved and imported into a dedicated workstation for radiomic analysis. Manually drawn regions of interest (ROI) allowed the extraction of radiomic features (RFs) from the tumor. Results: A positive association was found between NICD and Jag1 expression (p < 0.001). Median PFS was significantly shorter in patients whose tumors expressed high NICD and Jag1 (6.43 months vs 11.53 months for negative cases; p = 0.001). Those with an MVD score ≥5 (CD31-high, NICD/Jag1 positive) experienced significantly poorer survival. The radiomic model developed to predict short and long-term survival and PFS yielded a ROC-AUC of 0.709; when integrated with clinical and histopathological data, the integrated model improved the predictive score (ROC-AUC of 0.823). Discussion: These results show that high NICD and Jag1 expression are associated with progressive disease and early disease progression to anti VEGF-based therapy; the preliminary radiomic analyses show that the integration of quantitative information with clinical and histological data display the highest performance in predicting the outcome of CRC patients. [ABSTRACT FROM AUTHOR]

As a highly evolutionary conserved long non-coding RNA, metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was first demonstrated to be related to lung tumor metastasis by promoting angiogenesis. To investigate the role of MALAT1 in traumatic brain injury, we established mouse models of controlled cortical impact and cell models of oxygen-glucose deprivation to mimic traumatic brain injury in vitro and in vivo. The results revealed that MALAT1 silencing in vitro inhibited endothelial cell viability and tube formation but increased migration. In MALAT1-deficient mice, endothelial cell proliferation in the injured cortex, functional vessel density and cerebral blood flow were reduced. Bioinformatic analyses and RNA pull-down assays validated enhancer of zeste homolog 2 (EZH2) as a downstream factor of MALAT1 in endothelial cells. Jagged-1, the Notch homolog 1 (NOTCH1) agonist, reversed the MALAT1 deficiency-mediated impairment of angiogenesis. Taken together, our results suggest that MALAT1 controls the key processes of angiogenesis following traumatic brain injury in an EZH2/NOTCH1-dependent manner.

IntroductionThe Notch intracellular domain (NICD) and its ligands Jagged-1(Jag1), Delta-like ligand (DLL-3) and DLL4 play an important role in neoangiogenesis. Previous studies suggest a correlation between the tissue levels of NICD and response to therapy with bevacizumab in colorectal cancer (CRC). Another marker that may predict outcome in CRC is radiomics of liver metastases. The aim of this study was to investigate the expression of NICD and its ligands and the role of radiomics in the selection of treatment-naive metastatic CRC patients receiving bevacizumab.MethodsImmunohistochemistry (IHC) for NICD, Jag1 and E-cadherin was performed on the tissue microarrays (TMAs) of 111 patients with metastatic CRC treated with bevacizumab and chemotherapy. Both the intensity and the percentage of stained cells were evaluated. The absolute number of CD4+ and CD8+ lymphocytes was counted in three different high-power fields and the mean values obtained were used to determine the CD4/CD8 ratio. The positivity of tumor cells to DLL3 and DLL4 was studied. The microvascular density (MVD) was assessed in fifteen cases by counting the microvessels at 20x magnification and expressed as MVD score. Abdominal CT scans were retrieved and imported into a dedicated workstation for radiomic analysis. Manually drawn regions of interest (ROI) allowed the extraction of radiomic features (RFs) from the tumor.ResultsA positive association was found between NICD and Jag1 expression (p < 0.001). Median PFS was significantly shorter in patients whose tumors expressed high NICD and Jag1 (6.43 months vs 11.53 months for negative cases; p = 0.001). Those with an MVD score ≥5 (CD31-high, NICD/Jag1 positive) experienced significantly poorer survival. The radiomic model developed to predict short and long-term survival and PFS yielded a ROC-AUC of 0.709; when integrated with clinical and histopathological data, the integrated model improved the predictive score (ROC-AUC of 0.823).DiscussionThese results show that high NICD and Jag1 expression are associated with progressive disease and early disease progression to anti VEGF-based therapy; the preliminary radiomic analyses show that the integration of quantitative information with clinical and histological data display the highest performance in predicting the outcome of CRC patients.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common genetic disorder among those responsible for hereditary strokes, and it is caused by a mutation in the NOTCH3 gene on chromosome 19. Blood biomarkers related to the Notch signaling pathway have not been investigated extensively in CADASIL. In this study, we measured the serum and plasma levels of NOTCH3 extracellular domain (N3ECD) and its ligand, Jagged-1, in 279 healthy subjects. The levels of N3ECD and Jagged-1 showed significant correlations in both serum (p < 0.0001, r = 0.2681) and plasma (p < 0.0001, r = 0.4065). The N3ECD levels were significantly higher in the serum than in plasma and tend to increase with age. In contrast, there was no significant difference between the serum and plasma levels of Jagged-1 levels. To summarize, we were able to measure N3ECD and Jagged-1 protein levels in healthy human serum and plasma. Taken together, our findings provide the basis for further studies investigating the clinical use of blood N3ECD and Jagged-1 levels for CADASIL and other Notch signaling-related diseases. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of Notch signaling pathways on differentiation of mouse embryonic stem cells(ESC) into haematopoietic stem or progenitor cells(HSC/HPC). Methods 1)incubate mouse embryoid body cells and divide the embryonic stem cells into five groups as EB group,control group,Jagged-1 group, DAPT group and Jagged-1-DAPT group. 2)detect the phenotype of HSC/HPC by flow cytometry. 3)The expression of Notch signaling pathway, mouse embryonic stem cell phenotype and HSC/HPC phenotype were detected by RT-PCR. Results 1)the number of embryonic stem cells in Jagged-1 group was significantly more than that in control group and Jagged-DAPT group(P＜0.05);2)the number of HSC/HPC in Jagged-1-DAPT group was significantly more than that in control group and in Jagged-1 group(P＜0.05); 3)the expression of Notch1, Notch2 and Notch4 mRNA in Jagged-1 group was significantly higher than that in control group(P＜0.05), 4)the expression of Notch1 and Notch4 mRNA in DAPT group and Jagged-1-DAPT group was lower than that in control group(P＜0.05). Conclusions Jagged-1 activation of Notch signaling pathway potentially inhibits ESC differentiation into HSC/HPC in mice model.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common genetic disorder among those responsible for hereditary strokes, and it is caused by a mutation in the NOTCH3 gene on chromosome 19. Blood biomarkers related to the Notch signaling pathway have not been investigated extensively in CADASIL. In this study, we measured the serum and plasma levels of NOTCH3 extracellular domain (N3ECD) and its ligand, Jagged-1, in 279 healthy subjects. The levels of N3ECD and Jagged-1 showed significant correlations in both serum (p < 0.0001, r = 0.2681) and plasma (p < 0.0001, r = 0.4065). The N3ECD levels were significantly higher in the serum than in plasma and tend to increase with age. In contrast, there was no significant difference between the serum and plasma levels of Jagged-1 levels. To summarize, we were able to measure N3ECD and Jagged-1 protein levels in healthy human serum and plasma. Taken together, our findings provide the basis for further studies investigating the clinical use of blood N3ECD and Jagged-1 levels for CADASIL and other Notch signaling-related diseases.

Purpose: To investigate the potential effect and explore the underlying mechanism of action of miR-558 in the odontogenic differentiation of human periodontal ligament fibroblasts (hPLFs). Methods: Human periodontal ligament fibroblasts were treated with osteogenic induction medium to induce odontogenic differentiation. The efficiency of odontogenic differentiation was determined using Alizarin red staining and alkaline phosphatase (ALP) activity assays. The expression levels of osteogenic markers, including Osterix and Runx2, were determined by Western blotting, while mRNA levels of Jagged-1, HES1 and HEY1 were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Results: MiR-558 was down-regulated during the odontogenic differentiation of hPLFs. Alizarin red staining and ALP activity data indicate that miR-558 significantly inhibited the odontogenic differentiation of hPLFs. Osterix and Runx2 expression levels were significantly decreased in the miR-558 mimic group but significantly increased in miR-558 inhibitor group compared with those in NC group (p < 0.01). Moreover, miR-558 regulated Notch signaling by targeting Jagged-1, while Jagged-1 knockdown suppressed the odontogenic differentiation of hPLFs. Conclusion: MiR-558 inhibits the odontogenic differentiation of human periodontal ligament fibroblasts by negatively regulating Jagged-1/Notch signaling pathway, and thus, could serve as a potential target to regulate the odontogenic differentiation of hPLFs. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS) is a late-onset devastating degenerative disease mainly affecting motor neurons. Motor neuron degeneration is accompanied and aggravated by oligodendroglial pathology and the presence of reactive astrocytes and microglia. We studied the role of the Notch signaling pathway in ALS, as it is implicated in several processes that may contribute to this disease, including axonal retraction, microgliosis, astrocytosis, oligodendrocyte precursor cell proliferation and differentiation, and cell death. We observed abnormal activation of the Notch signaling pathway in the spinal cord of SOD1G93A mice, a well-established model for ALS, as well as in the spinal cord of patients with sporadic ALS (sALS). This increased activation was particularly evident in reactive GFAP-positive astrocytes. In addition, one of the main Notch ligands, Jagged-1, was ectopically expressed in reactive astrocytes in spinal cord from ALS mice and patients, but absent in resting astrocytes. Astrocyte-specific inactivation of Jagged-1 in presymptomatic SOD1G93A mice further exacerbated the activation of the Notch signaling pathway and aggravated the course of the disease in these animals without affecting disease onset. These data suggest that aberrant Notch signaling activation contributes to the pathogenesis of ALS, both in sALS patients and SOD1G93A mice, and that it is mitigated in part by the upregulation of astrocytic Jagged-1.

Abstract Background In mammalian intestines, Notch signaling plays a critical role in mediating cell fate decisions; it promotes the absorptive (or enterocyte) cell fate, while concomitantly inhibiting the secretory cell fate (i.e. goblet, Paneth and enteroendocrine cells). We recently reported that intestinal-specific Kaiso overexpressing mice (Kaiso Tg ) exhibited chronic intestinal inflammation and had increased numbers of all three secretory cell types, hinting that Kaiso might regulate Notch signaling in the gut. However, Kaiso’s precise role in Notch signaling and whether the Kaiso Tg secretory cell fate phenotype was linked to Kaiso-induced inflammation had yet to be elucidated. Methods Intestines from 3-month old Non-transgenic and Kaiso Tg mice were “Swiss” rolled and analysed for the expression of Notch1, Dll-1, Jagged-1, and secretory cell markers by immunohistochemistry and immunofluorescence. To evaluate inflammation, morphological analyses and myeloperoxidase assays were performed on intestines from 3-month old Kaiso Tg and control mice. Notch1, Dll-1 and Jagged-1 expression were also assessed in stable Kaiso-depleted colon cancer cells and isolated intestinal epithelial cells using real time PCR and western blotting. To assess Kaiso binding to the DLL1, JAG1 and NOTCH1 promoter regions, chromatin immunoprecipitation was performed on three colon cancer cell lines. Results Here we demonstrate that Kaiso promotes secretory cell hyperplasia independently of Kaiso-induced inflammation. Moreover, Kaiso regulates several components of the Notch signaling pathway in intestinal cells, namely, Dll-1, Jagged-1 and Notch1. Notably, we found that in Kaiso Tg mice intestines, Notch1 and Dll-1 expression are significantly reduced while Jagged-1 expression is increased. Chromatin immunoprecipitation experiments revealed that Kaiso associates with the DLL1 and JAG1 promoter regions in a methylation-dependent manner in colon carcinoma cell lines, suggesting that these Notch ligands are putative Kaiso target genes. Conclusion Here, we provide evidence that Kaiso’s effects on intestinal secretory cell fates precede the development of intestinal inflammation in Kaiso Tg mice. We also demonstrate that Kaiso inhibits the expression of Dll-1, which likely contributes to the secretory cell phenotype observed in our transgenic mice. In contrast, Kaiso promotes Jagged-1 expression, which may have implications in Notch-mediated colon cancer progression.

Breast cancer is the most common type of invasive cancer in females and metastasis is one of the major causes of breast cancer-associated mortality. Following detachment from the primary site, disseminated tumor cells (DTCs) enter the bloodstream and establish secondary colonies during the metastatic process. An increasing amount of studies have elucidated the importance of Notch signaling in breast cancer metastasis; therefore, the present review focuses on the mechanisms by which Notch contributes to the occurrence of breast cancer DTCs, increases their motility, establishes interactions with the tumor microenvironment, protects DTCs from host surveillance and finally facilitates secondary colonization. Identification of the underlying mechanisms of Notch-associated breast cancer metastasis will provide additional insights that may contribute towards the development of novel Notch-targeted therapeutic strategies, which may aid in reducing metastasis, culminating in an improved patient prognosis. [ABSTRACT FROM AUTHOR]

Purpose of Review: This article reviews the past 2 years of research on Notch signaling as it relates to bone physiology, with the goal of reconciling seemingly discrepant findings and identifying fruitful areas of potential future research. Recent Findings: Conditional animal models and high-throughput omics have contributed to a greater understanding of the context-dependent role of Notch signaling in bone. However, significant gaps remain in our understanding of how spatiotemporal context and epigenetic state dictate downstream Notch phenotypes. Summary: Biphasic activation of Notch signaling orchestrates progression of mesenchymal progenitor cells through the osteoblast lineage, but there is a limited understanding of ligand- and receptor-specific functions. Paracrine Notch signaling through non-osteoblastic cell types contributes additional layers of complexity, and we anticipate impactful future work related to the integration of these cell types and signaling mechanisms. [ABSTRACT FROM AUTHOR]

Psoriasis is a chronic inflammatory disease characterized by the abnormal differentiation and hyperproliferation of epidermal keratinocytes. The aim of the present study was to investigate the mechanism by which microRNA-125b (miR-125b) inhibits the activation of the bromodomain-containing protein 4 (BRD4)/Notch signaling pathway in psoriasis. The contents of associated miRNAs in serum samples from 32 patients with psoriasis were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The most significantly downregulated miRNA, miR-125b, was screened out. In experiments using HaCaT cells, the association between miR-125b and cell proliferation was observed using a Cell Counting Kit-8 assay, that between miR-125b and the Notch signaling pathway was observed by western blotting and RT-qPCR, and that between miR-125b and the upstream molecule BRD4 of the Notch signaling pathway was observed by luciferase reporter assay and western blotting. The proliferation of HaCaT cells became apparent following miR-125b inhibition. The Jagged-1 ligand in the Notch signaling pathway was upregulated, the active intracellular domain of the Notch1 receptor was increasingly truncated, and the Notch signaling pathway was activated. Furthermore, the inhibited miR-125b contributed directly toward the upstream protein BRD4 3′-UTR of Jagged-1, ultimately activating the Notch signaling pathway with the upregulation of Jagged-1. In conclusion, the proliferation of HaCaT cells mediated by the Jagged-1/Notch signaling pathway was decreased with the miR-125b-mediated inhibition of BRD4 expression. Therefore, miR-125b may be a biomarker and potential therapeutic target for psoriasis treatment. [ABSTRACT FROM AUTHOR]

Retinoblastoma is an intraocular malignant tumor that may severely affect vision and represents a life-threatening disease in children. Arctigenin (ATG) is an active compound that exhibits numerous pharmacological activities, which is isolated from the seeds of greater burdock (Arctium lappa Linnaeus), a plant used in traditional Chinese herbal medicine. The present study aimed to investigate the effects of ATG on cancer progression by analyzing the retinoblastoma cell line Y79. ATG exhibited a significant inhibitory effect on the viability of Y79 cells in a dose-dependent manner. Furthermore, treatment with ATG promoted apoptosis, and increased the protein expression levels of B-cell lymphoma 2 (BCL-2)-associated X protein and decreased the protein expression levels of BCL-2. Cell migration was suppressed following treatment with ATG, as assessed by Transwell migration assay. Furthermore, the protein expression levels of jagged-1 (JAG1) were decreased, and various factors involved in the Notch signaling pathway, including the Notch intracellular domain (NICD), transcription factor HES (HES)5 and HES1 were downregulated following treatment with ATG. The decreased expression levels of JAG1 were restored in response to JAG1 overexpression, alongside increases in the protein expression levels of NICD, HES5 and HES1. Furthermore, overexpression of JAG1 partly restored the cell viability and migration suppressed following treatment with ATG. In addition, ATG-induced apoptosis was reduced by JAG1 overexpression. Collectively, the present results suggested that ATG may serve as an antitumor compound by suppressing the proliferation and migration of retinoblastoma cells, inducing apoptosis, downregulating the protein expression levels of JAG1, and decreasing the activity of the Notch signaling pathway. [ABSTRACT FROM AUTHOR]

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. • Exosomes from hypoxia-preconditioned SCAPs accelerate cell proliferation, migration and tube formation of HUVECs. • Exosomes from hypoxia-preconditioned SCAPs deliver JAG1 protein to upregulate Notch1 signaling cascade and VEGF production in HUVECs. • Exosomes from hypoxia-preconditioned SCAPs promote angiogenesis of HUVECs through delivering JAG1 to HUVECs. [ABSTRACT FROM AUTHOR]

Sirtuins (SIRT) are ubiquitous histone and protein deacetylases and a member of this family, SIRT1, is the best-studied one. Its functions in endothelial cells encompass branching angiogenesis, activation of endothelial nitric oxide synthase, regulation of proapoptotic and proinflammatory pathways, among others. Defective SIRT1 activity has been described in various cardiovascular, renal diseases and in aging-associated conditions. Therefore, understanding of SIRT1-deficient, endothelial dysfunctional phenotype has much to offer clinically. Here, we summarize recent studies by several investigative teams of the characteristics of models of global endothelial SIRT1 deficiency, the causes of facilitative development of fibrosis in these conditions, dissect the protein composition of the aberrant secretome of SIRT1-deficient endothelial cells and present several components of this aberrant secretome that are involved in fibrogenesis via activation of fibroblasts to myofibroblasts. These include ligands of Wnt and Notch pathways, as well as proteolytic fragments of glycocalyx core protein, syndecan-4. The latter finding is crucial for understanding the degradation of glycocalyx that accompanies SIRT1 deficiency. This spectrum of abnormalities associated with SIRT1 deficiency in endothelial cells is essential for understanding the origins and features of endothelial dysfunction in a host of cardiovascular and renal diseases.

Abstract Amyotrophic lateral sclerosis (ALS) is a late-onset devastating degenerative disease mainly affecting motor neurons. Motor neuron degeneration is accompanied and aggravated by oligodendroglial pathology and the presence of reactive astrocytes and microglia. We studied the role of the Notch signaling pathway in ALS, as it is implicated in several processes that may contribute to this disease, including axonal retraction, microgliosis, astrocytosis, oligodendrocyte precursor cell proliferation and differentiation, and cell death. We observed abnormal activation of the Notch signaling pathway in the spinal cord of SOD1 G93A mice, a well-established model for ALS, as well as in the spinal cord of patients with sporadic ALS (sALS). This increased activation was particularly evident in reactive GFAP-positive astrocytes. In addition, one of the main Notch ligands, Jagged-1, was ectopically expressed in reactive astrocytes in spinal cord from ALS mice and patients, but absent in resting astrocytes. Astrocyte-specific inactivation of Jagged-1 in presymptomatic SOD1 G93A mice further exacerbated the activation of the Notch signaling pathway and aggravated the course of the disease in these animals without affecting disease onset. These data suggest that aberrant Notch signaling activation contributes to the pathogenesis of ALS, both in sALS patients and SOD1 G93A mice, and that it is mitigated in part by the upregulation of astrocytic Jagged-1. Highlights • The Notch pathway is overactive in spinal cords of sALS patients and ALS mice. • Reactive astrocytes from sALS patients and ALS mice overexpress Jagged-1 and NICD-1. • Astrocyte-specific inactivation of Jagged-1 accelerates disease progression in ALS mice, after onset. • Jagged-1 inactivation in astrocytes enhances Notch signaling activation in ALS mice. • Reactive astrocytes express Jagged-1 to limit Notch activation by cis-inhibition. [ABSTRACT FROM AUTHOR]

Abstract Although transplantation of pancreatic islets is a promising approach for treatment of type 1 diabetes mellitus, the engraftment efficiency of these islets is limited by host immune responses. Extensive efforts have been made to immunoisolate these islets by introducing barriers on the islet surface. To date, these barriers have not successfully protected islets from attack by the immune system. In addition, the inevitable permeability of an islet capsule cannot prevent filtration by proinflammatory cytokines and islet self-antigens. Thus, we have developed a surface engineering approach for localized immonumodulation of the islet microenvironment. Jagged-1 (JAG-1), as a potent immunomodulatory factor, was immobilized on the islet surface by mediation of a double-layer of heterobifunctional poly (ethylene glycol) (PEG). Immobilization and functionality of JAG-1 on PEGylated islet surfaces were established. When co-cultured with splenocytes, the JAG-1 conjugated islets induced a significant increase in regulatory T cells and regulated the cytokine levels produced by immune cells. The results demonstrated that JAG-1 immobilization could improve immunoprotection of pancreatic islets by localized modulation of the immune milieu from an inflammatory to an anti-inflammatory state. We also evaluated the effects of surface modification of these islets by JAG-1 in a xenotransplantation model. The transplanted JAG-1/PEG/islets group showed a significantly reduced blood glucose levels compared with the control group of diabetic mice during the acute phase of the immune response to the transplanted islets. Our results demonstrated that surface modification has the potential to shift the immune system from an inflammatory to anti-inflammatory milieu and may offer a new prospective for immunoprotection of pancreatic islets. Graphical abstract Surface engineering of pancreatic islets by jagged-1 (JAG-1) and poly(ethylene glycol) (PEG). (A) Immunoisolation of pancreatic islet surface by a double-layer of PEG. Although PEGylation can protect the islets from infiltration of immune cells and reduce host-cell interactions, the cytokines produced by immune cells can still potentially diffuse through this barrier. (B) Immobilization of JAG-1 as an immunomodulatory agent on the PEGylated islets surface can induce an immunomodulatory milieu thought induction of T regs , upregulation of anti-inflammatory cytokines, and downregulation of inflammatory cytokines around the islets to enable efficient islet immunoprotection. Image 1 [ABSTRACT FROM AUTHOR]

NOTCH signalling is an evolutionarily conserved juxtacrine signalling pathway that is essential in development. Jagged1 (JAG1) and Delta-like ligand 4 (DLL4) are transmembrane NOTCH ligands that regulate angiogenesis by controlling endothelial cell (EC) differentiation, vascular development and maturation. In addition, DLL4 could bypass its canonical cell-cell contact-dependent signalling to influence NOTCH signalling and angiogenesis at a distance when it is packaged into extracellular vesicles (EVs). However, it is not clear whether JAG1 could also be packaged into EVs to influence NOTCH signalling and angiogenesis. In this work, we demonstrate that JAG1 is also packaged into EVs. We present evidence that JAG1-EVs inhibit NOTCH signalling and regulate EC behaviour and function. JAG1-EVs inhibited VEGF-induced HUVEC proliferation and migration in 2D culture condition and suppressed sprouting in a 3D microfluidic microenvironment. JAG1-EV treatment of HUVECs leads to a reduction of Notch1 intracellular domain (N1-ICD), and the proteasome and the intracellular domain of JAG1 (JAG1-ICD) are both required for this reduction to occur. These findings reveal a novel mechanism of JAG1 function in NOTCH signalling and ECs through EVs. [ABSTRACT FROM AUTHOR]

Background Epithelial to mesenchymal transition (EMT) is considered to be important for cancer invasion and metastasis. Tumour hypoxia, in addition to Transforming Growth Factor-β (TGF-β) and Notch, amongst others, have been suggested to be involved in EMT. We therefore investigated if hypoxia, TGF-β1 and the Notch ligand Jagged-1 alone induced morphological changes with corresponding EMT signatures in different epithelial breast cancer cell lines in vitro. Furthermore, we also studied whether or not TGF-β1, or Jagged-1 in combination with hypoxia added any effect on EMT. Methods The cells were exposed to normoxia or hypoxia alone or in combination with TGF-β1 or Jagged-1. Morphological responses to treatment were investigated by light microscopy, and changes in markers for EMT and hypoxia were evaluated by western blot analysis and immunofluorescence studies. Results One of the four cell lines (MCF7) became elongated and highly multipolar, indicative of EMT, following hypoxia, TGF-β1 and Jagged-1 treatment per se with the most distinct morphological shift seen with Jagged-1 treatment in combination with hypoxia. Also, when regarding hypoxia, MCF7 cells showed the greatest change in EMT-markers of the four cell lines tested, but these changes were not consistent with a typical EMT pattern. The morphology of BT474 cells was not altered following Jagged-1 treatment, however, Jagged-1 increased E-cadherin levels. Morphology was changed following TGF-β1 treatment of BT474 cells, but it did not affect E-cadherin levels. Neither Jagged-1 nor TGF-β1 altered the levels of Vimentin in the BT474 cell line. The E-cadherin responses to hypoxia varied with end-point in both MCF7 and BT474 cells, and in most cases were not consistent with EMT. Conclusion Our results using four different breast cancer cell lines in vitro do not provide evidence that EMT is induced by hypoxia alone or in combination with TGF-β1 or the Notch ligand Jagged-1. The inconsistency in morphological appearance and EMT-markers, as well as the time dependent variation in E-cadherin responses could not support EMT. Importantly, there was not one single common response pattern to the stimuli used, suggesting that cell lines with different hormone statuses display individual traits that respond differently to the stimuli applied. Thus, based on the present results, common statements that single factors by themselves can induce EMT seem questionable. [ABSTRACT FROM AUTHOR]

Background: In mammalian intestines, Notch signaling plays a critical role in mediating cell fate decisions; it promotes the absorptive (or enterocyte) cell fate, while concomitantly inhibiting the secretory cell fate (i.e. goblet, Paneth and enteroendocrine cells). We recently reported that intestinal-specific Kaiso overexpressing mice (KaisoTg) exhibited chronic intestinal inflammation and had increased numbers of all three secretory cell types, hinting that Kaiso might regulate Notch signaling in the gut. However, Kaiso's precise role in Notch signaling and whether the KaisoTg secretory cell fate phenotype was linked to Kaiso-induced inflammation had yet to be elucidated. Methods: Intestines from 3-month old Non-transgenic and KaisoTg mice were "Swiss" rolled and analysed for the expression of Notch1, Dll-1, Jagged-1, and secretory cell markers by immunohistochemistry and immunofluorescence. To evaluate inflammation, morphological analyses and myeloperoxidase assays were performed on intestines from 3-month old KaisoTg and control mice. Notch1, Dll-1 and Jagged-1 expression were also assessed in stable Kaisodepleted colon cancer cells and isolated intestinal epithelial cells using real time PCR and western blotting. To assess Kaiso binding to the DLL1, JAG1 and NOTCH1 promoter regions, chromatin immunoprecipitation was performed on three colon cancer cell lines. Results: Here we demonstrate that Kaiso promotes secretory cell hyperplasia independently of Kaiso-induced inflammation. Moreover, Kaiso regulates several components of the Notch signaling pathway in intestinal cells, namely, Dll-1, Jagged-1 and Notch1. Notably, we found that in KaisoTg mice intestines, Notch1 and Dll-1 expression are significantly reduced while Jagged-1 expression is increased. Chromatin immunoprecipitation experiments revealed that Kaiso associates with the DLL1 and JAG1 promoter regions in a methylation-dependent manner in colon carcinoma cell lines, suggesting that these Notch ligands are putative Kaiso target genes. Conclusion: Here, we provide evidence that Kaiso's effects on intestinal secretory cell fates precede the development of intestinal inflammation in KaisoTg mice. We also demonstrate that Kaiso inhibits the expression of Dll-1, which likely contributes to the secretory cell phenotype observed in our transgenic mice. In contrast, Kaiso promotes Jagged-1 expression, which may have implications in Notch-mediated colon cancer progression. [ABSTRACT FROM AUTHOR]

This study aims to investigate the potential synergistic effect of the combined treatment of galloylquinic acid compounds from Copaifera lucens with doxorubicin via the modulation of the Notch pathway in solid Ehrlich carcinoma-bearing mice model. The solid tumor model was induced by subcutaneous inoculation of Ehrlich carcinoma cells in the right hind limb of mice, after serial syngeneic cell passages in the peritoneal cavity. Sixty mice were allocated into five groups including treated groups with galloylquinic acid compounds, doxorubicin, and their combination. Normal and tumor control groups were also assigned. Tissue homogenates were collected to measure the levels of the Notch-1, Hes-1, Jagged-1, TNF-α, IL-6 and VEGF, as well as SOD, MDA, and GSH. Histopathological and immunohistochemical examinations of tumor or control tissues were also performed for the levels of NF-κB p65, cyclin D1 and caspase 3 activity. Our results showed that the combined treatment of galloylquinic acid compounds with doxorubicin significantly decreased the levels of the Notch-1, Hes-1, Jagged-1, TNF-α, IL-6, VEGF, NF-κB p65, and cyclin D1 in tumor tissues. Moreover, the compounds induced cancer cell death as evidence by increasing the caspase 3 activity, and they possessed potent inhibitory effects on oxidative stress. Galloylquinic acid compounds exhibited promising antineoplastic effects and promoted the chemosensitivity of doxorubicin, mainly by modulating the Notch signaling pathway and its downstream effectors. These compounds may be considered in solid tumors treatment for improving the efficacy and reducing the side effects of chemotherapeutic agents. [Display omitted] [ABSTRACT FROM AUTHOR]

Notch receptor-ligand interactions are critical for cell proliferation, differentiation and survival; however, the role of Notch signalling in psoriasis remains to be elucidated. Serum amyloid A ( A- SAA) is an acute-phase protein with cytokine-like properties, regulates cell survival pathways and is implicated in many inflammatory conditions. To examine the role of Notch-1 signalling in the pathogenesis of psoriasis, Notch-1, DLL-4, Jagged-1, Hrt-1/ Hrt-2, A- SAA, Factor VIII and vascular endothelial growth factor ( VEGF) mRNA and/or protein expression in psoriasis skin biopsies, serum and dHMVEC were assessed by immunohistology, dual-immunofluorescence, real-time PCR, ELISA and Western blotting. A- SAA-induced angiogenesis and invasion in the presence of Notch-1 si RNA was assessed by matrigel tube formation assays and Transwell invasion assay. Increased Notch-1, its ligand DLL-4 and Hrt-1 expression were demonstrated in lesional skin compared with non-lesional skin, with greatest expression observed in the dermal vasculature ( P < 0.05). Dual-immunofluorescent staining demonstrated co-localization of Notch-1 to endothelial cell marker Factor VIII. A significant increase in A- SAA levels was demonstrated in psoriasis serum compared with healthy control serum ( P < 0.05), and A-SAA expression was higher in lesional skin compared with non-lesional. In dHMVEC, A- SAA significantly induced Jagged-1, Hrt-1 and VEGF mRNA expression ( P < 0.05) and activated Notch-1 IC indicative of transcriptional regulation. In contrast, A- SAA significantly inhibited DLL-4 mRNA expression ( P < 0.05). Finally A- SAA-induced angiogenesis and invasion were inhibited by Notch-1 si RNA ( P < 0.05). Notch receptor-ligand interactions mediate vascular dysfunction in psoriasis and may represent a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Activation of Notch by Jagged-1 may plays a pivotal role in maturation of dendritic cells (DCs), but the mechanism has not been completely defined. In the present study, Hes-1 (Hairy/enhancer-of-split)-targeting siRNA was used to confirm a role of Jagged-1-Notch signaling pathway activation in maturation of murine bone marrow-derived DCs and to search for a target that plays a critical role. The results showed that compared with the control, lipopolysaccharide or Zymosan A groups, Jagged-1 (a soluble Jagged 1/Fc chimera protein) effectively increased expression of Hes-1 and Deltex-1 mRNA, which could be reversed by DAPT (2, 4-diamino-5-phenylthiazole), a specific inhibitor of the Notch signaling pathway. Hes-1-targeting siRNA could successfully down-regulate the endogenous Hes-1 expression in the DCs. Concurrently, a significant down-regulation of CD40, CD80, CD86 and MHC-II expressions on the surface of the DCs was found with the reduction of IL-12 yielded by the DCs. Our results demonstrate that Hes-1-targeting siRNA can inhibit the maturation of the DCs induced by Jagged-1, indicating Hes-1 may be an important target of Notch signaling mediating the maturation of DCs. [ABSTRACT FROM AUTHOR]

Notch signaling plays critical roles in various cell types by regulating cell fate determination and differentiation. Here, we investigated the ability to control differentiation of human periodontal ligament derived mesenchymal stem cells using modified surfaces containing the affinity immobilized Notch ligand, Jagged-1. After seeding human periodontal ligament derived mesenchymal stem cells (HPDLs) on Jagged-1 modified surfaces, expression of Notch signaling target genes, Hes-1 and Hey-1, was higher than those exposed to soluble Jagged-1 or control surfaces. Upregulation of Notch signaling target genes was attenuated after treatment with the γ secretase inhibitor. Upon seeding the cells on Jagged-1 immobilized surface and maintained in osteogenic medium, alkaline phosphatase enzymatic activity and mineralization as well as mRNA expression of alkaline phosphatase (ALP), collagen type I (COL I) and osteopontin (OPN) were significantly increased compared to those of controls. However, osteocalcin (OCN) mRNA expression level was decreased when cells were exposed to Jagged-1 modified surfaces. HPDLs on Jagged-1 modified surfaces expressed lower TWIST2 mRNA levels than the control, suggesting that the mechanism whereby Jagged-1 enhances osteogenic differentiation of HPDLs may occur through Notch signaling and TWIST regulation. In summary, an alteration of biomaterial interface using Notch ligands illustrates a promising system to control HPDLs differentiation toward osteogenic lineage. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013. [ABSTRACT FROM AUTHOR]

As a highly evolutionary conserved long non-coding RNA, metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was first demonstrated to be related to lung tumor metastasis by promoting angiogenesis. To investigate the role of MALAT1 in traumatic brain injury, we established mouse models of controlled cortical impact and cell models of oxygen-glucose deprivation to mimic traumatic brain injury in vitro and in vivo. The results revealed that MALAT1 silencing in vitro inhibited endothelial cell viability and tube formation but increased migration. In MALAT1-deficient mice, endothelial cell proliferation in the injured cortex, functional vessel density and cerebral blood flow were reduced. Bioinformatic analyses and RNA pull-down assays validated enhancer of zeste homolog 2 (EZH2) as a downstream factor of MALAT1 in endothelial cells. Jagged-1, the Notch homolog 1 (NOTCH1) agonist, reversed the MALAT1 deficiency-mediated impairment of angiogenesis. Taken together, our results suggest that MALAT1 controls the key processes of angiogenesis following traumatic brain injury in an EZH2/NOTCH1-dependent manner., Competing Interests: None

Mel-18 has been proposed as a negative regulator of Bmi-1, a cancer stem cell (CSC) marker, but it is still unclear whether Mel-18 is involved in CSC regulation. Here, we examined the effect of Mel-18 on the stemness of human breast CSCs. In Mel-18 small hairpin RNA (shRNA)-transduced MCF-7 cells, side population (SP) cells and breast CSC surface marker (CD44+/CD24-/ESA+)-expressing cells, which imply a CSC population, were enriched. Moreover, the selfrenewal of CSCs was enhanced by Mel-18 knockdown, as measured by the ability for tmnorsphere formation in vitro and tumor-initiating capacity in vivo. Similarly, Mel-18 overexpression inhibited the number and selfrenewal activity of breast CSCs in SK-BR-3 cells. Furthermore, our data showed that Mel-18 blockade upregulated the expression of the Wnt/TCF target Jagged-l, a Notch Ugand, and consequently activated the Notch pathway. Pharmacologic inhibition of the Notch and Wnt pathways abrogated Mel-18 knockdown-mediated tnmorsphere formation ability. Taken together, our findings suggest that Mel-18 is a novel negative regulator of breast CSCs that inhibits the stem cell population and in vitro and in vivo self-renewal through the inactivation of Wnt-mediated Notch signaling. [ABSTRACT FROM AUTHOR]

Loss or decreased expression of runt-related transcription factor 3 (RUNX3), a tumor suppressor gene involved in gastric and other cancers, has been frequently observed in hepatocellular carcinoma (HCC). The objective of this study was to identify the regulatory mechanism of the epithelial-mesenchymal transition (EMT) by RUNX3 in HCC. Human HCC cell lines, Hep3B, Huh7, HLF and SK-Hep1, were divided into low- and high-EMT lines, based on their expression of TWIST1 and SNAI2, and were used in this in vitro study. Ectopic RUNX3 expression had an anti-EMT effect in low-EMT HCC cell lines characterized by increased E-cadherin expression and decreased N-cadherin and vimentin expression. RUNX3 expression has previously been reported to reduce jagged-1 (JAG1) expression; therefore, JAG1 ligand peptide was used to reinduce EMT in RUNX3-expressing low-EMT HCC cells. Immunohistochemical analyses were performed for RUNX3, E-cadherin, N-cadherin and TWIST1 in 33 human HCC tissues, also divided into low- and high-EMT HCC, based on TWIST1 expression. E-cadherin expression was correlated positively and N-cadherin expression was correlated negatively with RUNX3 expression in low-EMT HCC tissues. Correlations between EMT markers and RUNX3 mRNA expression were analyzed using Oncomine datasets. Similarly, mRNA expression of E-cadherin was also significantly correlated with that of RUNX3 in low-EMT HCC, while mRNA expression of JAG1 was negatively correlated with that of RUNX3. These results suggest a novel mechanism by which loss or decreased expression of RUNX3 induces EMT via induction of JAG1 expression in low-EMT HCC. [ABSTRACT FROM AUTHOR]

Jagged-1-educated dendritic cells (DCs) are of distinct phenotypes different from Lipopolysaccharide (LPS)-educated DCs. However, to date, little is known as to nano-features of Jagged-1-educated DCs. In this study, nanostructure of Jagged-1-educated DCs was observed through atomic force microscopy. Our results showed that the volume, surface area and width of Jagged-1-educated DCs, and the number of protrusion, pseudopodia and lamellapodia on the surface of Jagged-1-educated DCs were significantly more than those of GM-CSF-induced DCs, but less than those of LPS-educated DCs. Compared with GM-CSF-induced DCs, the roughness on the surface of Jagged-1-educated DCs was greatly increased, similar to LPS-educated DCs, but the particle size and number of them on the membrane were markedly less than the latter. The change of DC nanostructure caused by Jagged-1 was abrogated with N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycinet-butyl ester, a γ-secretase inhibitor of Notch signaling pathway. Compared to LPS-educated DCs, Jagged-1-educated DCs highly expressed NICD, Deltex-1 and Hes-1 proteins, moderately produced IL-12, but not IFN-γ, and the level of CD40 molecules on the surface of them was much lower, suggesting that Jagged-1-educated DCs are in a semi-mature status and may have unique functions distinguished from LPS-educated DCs. [ABSTRACT FROM AUTHOR]

Abstract: The possibility to induce myocardial regeneration by the activation of resident cardiac stem cells (CSCs) has raised great interest. However, to propose endogenous CSCs as therapeutic options, a better understanding of the complex mechanisms controlling heart morphogenesis is needed, including the cellular and molecular interactions that cardiomyocyte precursors establish with cells of the stromal compartment. In the present study, we co-cultured immature cardiomyocytes from neonatal mouse hearts with mouse bone marrow-derived mesenchymal stromal cells (MSCs) to investigate whether these cells could influence cardiomyocyte growth in vitro. We found that cardiomyocyte proliferation was enhanced by direct co-culture with MSCs compared with the single cultures. We also showed that the proliferative response of the neonatal cardiomyocytes involved the activation of Notch-1 receptor by its ligand Jagged-1 expressed by the adjacent MSCs. In fact, the cardiomyocytes in contact with MSCs revealed a stronger immunoreactivity for the activated Notch-intracellular domain (Notch-ICD) as compared with those cultured alone and this response was significantly attenuated when MSCs were silenced for Jagged-1. The presence of various cardiotropic cytokines and growth factors in the conditioned medium of MSCs underscored the contribution of paracrine mechanisms to Notch-1 up-regulation by the cardiomyocytes. In conclusions these findings unveil a previously unrecognized function of MSCs in regulating cardiomyocyte proliferation through Notch-1/Jagged-1 pathway and suggest that stromal-myocardial cell juxtacrine and paracrine interactions may contribute to the development of new and more efficient cell-based myocardial repair strategies. [Copyright &y& Elsevier]

Abstract: Blood production is a highly regulated process involving multiple inhibitory and stimulatory cytokines present in the haematopoietic stem cell niche. Small molecules mimics of these signalling molecules have substantial potential as drugs and in the development of bioreactors to generate blood products. We review the structural biology of the extracellular signalling domains of five of the most important cytokines, analyze their structure-property relationships, and summarize the progress in developing small molecule mimics using the molecular information from structural biology and mutation studies. [Copyright &y& Elsevier]

Platelet-derived growth factor-D (PDGF-D) has been linked with several human malignancies; however, its role in breast cancer progression is not known. We found that PDGF-D expressing breast cancer cell lines MDA-MB-231 and SUM-149 are more invasive compared to cell lines with little or no expression of PDGF-D such as MDA-MB-468 and MCF-7 cells. Over-expression of PDGF-D in PDGF-D low expressing MDA-MB-468 and MCF-7 cells by cDNA transfection showed increased cell proliferation while silencing the expression of PDGF-D by siRNA in PDGF-D high expressing MDA-MB-231 and SUM-149 cells showed decreased cell proliferation and increased apoptosis. Moreover, PDGF-D over-expression was positively correlated with the expression of Notch-1 and Jagged-1, and the expression of mesenchymal markers (Vimentin and ZEB-2) with concomitant decreased expression of epithelial marker E-cadherin. Since NF-κB activation plays a crucial role in Notch signaling as well as in epithelial-mesenchymal transition and tumor aggressiveness, we determined the DNA binding activity of NF-κB and our findings are consistent showing that PDGF-D over-expression led to increased DNA binding activity of NF-κB while it was found to be decreased by inactivation of PDGF-D. These results were also consistent with the expression and activity of MMP-9 and VEGF, as well as invasive characteristics. Further, forced expression of Notch-1/Jagged-1 by cDNA transfection de-repressed the effects of PDGF-D silencing on NF-κB activity and invasion. From these results, we conclude that PDGF-D plays an important role in breast tumor aggressiveness and this process is mechanistically linked with the activation of Notch and NF-κB signaling. [ABSTRACT FROM AUTHOR]

This article presents a study which investigated the prognostic role of the angiogenesis-related Notch ligands and receptors and the prognostic impact of the coexpression of vascular endothelial growth factor-A and Notch signaling. The study involved tumor tissue samples from 335 patients with stage I and IIIA nonsmall cell lung cancer (NSCLC). The key findings and conclusions of the investigation are detailed.

Abstract: Objective: The aim of this study was to clarify the functional role of Notch3 in human cervical carcinomas. Methods: Notch3 expression in cervical cancer was assessed by immunohistochemistry, and data on clinical variables were collected by retrospective chart review. We used dual-color fluorescence in situ hybridization (FISH) to analyze DNA copy number alterations in cervical cancer. Inactivation of Notch3 and knocking down Notch3 gene were done using γ-secretase inhibitor and Notch 3 specific SiRNA to asses Notch3 function in cervical cancer either in vivo or in vitro. Results: Immunohistochemical analysis revealed that Notch3 was significantly overexpressed in cervical squamous cell carcinomas compared with adenocarcinomas. In contrast to normal cervical tissue and cervical intraepithelial neoplasms [CINs], squamous cell carcinomas demonstrated higher nuclear Notch3 immunoreactivity. Notch3 amplification was not found in any cervical carcinomas using FISH analysis. Notch3 nuclear expression was significantly correlated with Jagged-1, a putative Notch3 ligand, and Pbx1b, a potential Notch3 downstream target (P <0.05).Patients with cervical carcinomas positive for nuclear Notch3 expression had significantly shorter overall survival than their peers whose tumors did not express nuclear Notch3. Inactivation of Notch3 decreased cell proliferation and induced apoptosis in ME180 and SKGIIIb cell lines that overexpressed Notch3. Injection of a γ-secretase inhibitor into ME180 cell tumors established on mice, demonstrated a reduction in tumor growth. Conclusion: Our findings suggest that Notch3 might play important role for the proliferation and survival of Notch3 overexpressing tumors and that inactivation of Notch3 may represent a new therapeutic avenue for cervical squamous cell carcinomas. [Copyright &y& Elsevier]

Background: Modern lifestyle and urbanization have been associated with a raised risk for atopic diseases whereas early and long-term exposure to a farm environment confers protection against atopic sensitization. Immunomodulatory potential and microbiological characteristics of settled airborne dust from an urban house and a barn were examined. Methods: Pulmonary inflammation was induced in mice by repeated intranasal administration of dusts. Monocyte-derived human dendritic cells (moDCs) were exposed to dusts followed by coculture with purified naïve T cells. Cytokine/chemokine mRNA and protein levels were analyzed by real-time polymerase chain reaction, enzyme-linked immunosorbent assay and flow cytometry. The dusts were analyzed by cloning and sequencing of 16S rRNA genes (290 sequences) for DNA, lipids, endotoxin and β-glucan, by live-dead staining, viable counting, isolation and identification of pure cultures (n = 76). Results: Repeated exposure to house dust elicited pulmonary eosinophilia in mice whereas exposure to barn dust elicited neutrophilic and lymphocytic airway inflammation. Stimulation of moDCs with urban house dust elicited expression of Th2-promoting OX40L and Jagged-1 costimulatory molecules. Dendritic cells (DCs) exposed to house dust directed naïve T cells towards Th2 responses. Exposure of DCs to barn dust elicited the development of Th1-dominated immune responses. Urban house dust contained bacterial debris almost exclusively of human commensal species (corynebacteria, streptococci) whereas barn dust comprised mainly intact, viable bacteria of high diversity and no commensal species. Conclusion: Contact to debris originating from human commensal bacteria in urban house dust elicited a Th2-type response whereas barn dust with high bacterial diversity directed the cells towards a Th1 response. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: The mechanisms by which human dendritic cells (DCs) activate a TH1-polarizing or TH2-polarizing program are still partially unclear. Objective: Study of the mechanisms responsible for the TH1/TH2-polarizing activity of human circulating myeloid DCs before and after ligation of their Toll-like receptors (TLRs). Methods: IL-4 and IFN-γ production by CD4+ T cells was assessed in cocultures with myeloid DCs before or after TLR triggering. Expression of Jagged-1 and Delta-4 Notch ligands and of GATA-3 and T-box expressed in T cells transcription factors was evaluated by real-time quantitative PCR. Signal transducer and activator of transcription 4 and 6 phosphorylation was assessed by flow cytometry. Knockdown of Jagged-1 or Delta-4 was performed by transfection of DCs with appropriate silencing mRNAs. Results: Myeloid immature DCs constitutively expressed Jagged-1, which induces in CD4+ T cells a TH2 polarization, as shown by Jagged-1 gene silencing. The TH2 polarization associated with high GATA-3/T-box expressed in T cells ratio and was at least partially dependent on the early induction of IL-4. Maturation of DCs by TLR ligation resulted in the reduction of Jagged-1 and upregulation of Delta-4, which was at least in part responsible for the polarization of CD4+ T cells to the TH1 phenotype. Conclusion: CD4+ T-cell responses are usually characterized by a prevalent TH2 phenotype unless TLRs are triggered on DCs by microbial components. [Copyright &y& Elsevier]

We investigated Notch signaling during chondrogenesis in human bone marrow stromal cells (hMSC) in three-dimensional cell aggregate culture. Expression analysis of Notch pathway genes in 14-day chondrogenic cultures showed that the Notch ligand Jagged-1 (Jag-1) sharply increased in expression, peaking at day 2, and then declined. A Notch target gene, HEY-1, was also expressed, with a temporal profile that closely followed the expression of Jag-1, and this preceded the rise in type II collagen expression that characterized chondrogenesis. We demonstrated that the shut-down in Notch signaling was critical for full chondrogenesis, as adenoviral human Jag-1 transduction of hMSC, which caused continuous elevated expression of Jag-1 and sustained Notch signaling over 14 days, completely blocked chondrogenesis. In these cultures, there was inhibited production of extracellular matrix, and the gene expression of aggrecan and type II collagen were strongly suppressed; this may reflect the retention of a prechondrogenic state. The JAG-1-mediated Notch signaling was also shown to be necessary for chondrogenesis, as N-[N-(3,5-difluorophenacetyl-L-alanyl)]- (S)-phenylglycine t-butyl ester (DAPT) added to cultures on days 0-14 or just days 0-5 inhibited chondrogenesis, but DAPT added from day 5 did not. The results thus showed that Jag-1-mediated Notch signaling in hMSC was necessary to initiate chondrogenesis, but it must be switched off for chondrogenesis to proceed. [ABSTRACT FROM AUTHOR]

The fetal brain is sensitive to a variety of teratogens, including ethanol. We showed previously that ethanol induced mitosis and stem cell maturation, but not death, in fetal cerebral cortex-derived progenitors. We tested the hypothesis that micro-RNAs (miRNAs) could mediate the teratogenic effects of ethanol in a fetal mouse cerebral cortex-derived neurosphere culture model. Ethanol, at a level attained by alcoholics, significantly suppressed the expression of four miRNAs, miR-21, -335, -9, and -153, whereas a lower ethanol concentration, attainable during social drinking, induced miR-335 expression. A GABAA receptor-dependent mechanism mediated miR-21, but not miR-335 suppression, suggesting that divergent mechanisms regulate ethanol-sensitive miRNAs. Antisense-mediated suppression of miR-21 expression resulted in apoptosis, suggesting that miR-21 is an antiapoptotic factor. miR-335 knockdown promoted cell proliferation and prevented death induced by concurrently suppressing miR-21, indicating that miR-335 is a proapoptotic, antimitogenic factor whose actions are antagonistic to miR-21. Computational analyses identified two genes, Jagged-1, a Notch-receptor ligand, and embryonic-lethal abnormal vision, Drosophila-like 2 (ELAVL2), a brain-specific regulator of RNA stability, as presumptive targets of three of four ethanol-sensitive micro-RNAs. Combined knockdown of miR-335, -21, and -153 significantly increased Jagged-1 mRNA. Furthermore, ethanol induced both Jagged-1 and ELAVL2 mRNA. The collective suppression of micro-RNAs is consistent with ethanol induction of cell cycle and neuroepithelial maturation in the absence of apoptosis. These data identify a role for micro-RNAs as epigenetic intermediaries, which permit teratogens to shape complex, divergent developmental processes, and additionally demonstrate that coordinately regulated miRNAs exhibit both functional synergy and antagonism toward each other. [ABSTRACT FROM AUTHOR]

Abstract: Effects of endogenous Notch ligands Jagged-1 and Delta-1 on maturation markers in adult mouse lymphocytes were checked in vitro on putative thymocyte precursors from bone marrow and on DN3 cells from the thymus. Both populations were cocultured with stromal cells (Small M, Histochem Cell Biol 2005;123:513) naturally expressing high levels of either Jagged-1 or Delta-1. Initially the bone marrow cells were Thy-1.2neg while the majority were B220hi. These trends were reversed by culture on both the Jagged-1hi and Delta-1hi monolayers. Then DN3 thymocytes were cultured with stroma expressing these two ligands and the T cell receptor β chain was expressed more clearly after coculture on Delta-1hi stroma. These findings indicate that stromal cells with endogenous Jagged-1 as well as Delta-1 could initiate early changes toward T cell commitment while Delta-1 favored later αβ-TCR development. [Copyright &y& Elsevier]

Abstract: There is an increasing body of evidence that suggests that genes involved in cell fate decisions and pattern formation during development also play a key role in the continuous cell fate decisions made by adult tissue stem cells. Here we show that prolonged in vitro culture (14 days) of murine bone marrow lineage negative cells in medium supplemented with three early acting cytokines (stem cell factor, Flk-2/Flt-3 ligand, thrombopoietin) and with immobilized Notch ligand, Jagged-1, resulted in robust expansion of serially transplantable hematopoietic stem cells with long-term repopulating ability. We found that the absolute number of marrow cells was increased ∼8 to 14-fold in all cultures containing recombinant growth factors. However, the frequency of high quality stem cells was markedly reduced at the same time, except in cultures containing growth factors and Jagged-1-coated Sepharose-4B beads. The absolute number of hematopoietic cells with long-term repopulating ability was increased ∼10 to 20-fold in the presence of multivalent Notch ligand. These results support a role for combinatorial effects by Notch and cytokine-induced signaling pathways in regulating hematopoietic stem cell fate and to a potential role for Notch ligand in increasing cell numbers in clinical stem cell transplantation. [Copyright &y& Elsevier]

This communication summarizes the procedures that enabled isolation of adult murine thymic stromal cell lines that naturally express Notch ligands Jagged-1 or Delta-1. Histochemical characterization of these cell lines, in terms of ligand and cell type, revealed epithelial cells that bear an antigen characteristic of the thymic medulla and express either Jagged-1 or Delta-1. FACS sorting of stromal cells that naturally express these and other ligands is thus feasible, and such cells can be used to investigate the activity of each ligand in Notch-mediated commitment to the T-lymphocyte pathway. [ABSTRACT FROM AUTHOR]

Abstract: Notch signalling pathway plays an important role in cell differentiation. To investigate the implications of Notch signalling in the differentiation of rat bone marrow (BM) cells into a liver cell lineage, we used cultured BM cells to examine the mRNA expression of Musashi-1, which positively regulates Notch signalling, and made a transplant model to examine the protein expression of Notch signalling markers. For the in vivo experiment, BM cells were collected from transgenic rats expressing green fluorescence protein (GFP) and transplanted into the spleens of recipient rats, in which liver damage had been induced with carbon tetrachloride. The expression of Notch receptor 1 (Notch-1), Jagged-1 and Musashi-1, in the transplanted GFP-positive BM cells was investigated by immunohistochemistry. The expression of the liver-specific proteins, alpha-fetoprotein and cytokeratin19 was also investigated. Musashi-1 mRNA became detectable in the BM cells on culture day 7 in vitro. After transplantation, GFP-positive BM cells were observed in the portal areas of the recipient''s livers. Notch-1, Jagged-1, Musashi-1, alpha-fetoprotein and cytokeratin19 were all expressed in the transplanted BM cells. These results suggest that the Notch signalling pathway plays a role in the differentiation of BM cells into a liver cell lineage. [Copyright &y& Elsevier]

Bone marrow (BM) stem cells have been shown to differentiate into liver cells. It remains difficult to sort and culture BM stem cells, and the gene expression of liver-specific proteins in these cells has not been fully investigated. We used a negative selective magnetic cell separation system to obtain stem cell-enriched BM cells. The cells obtained were cultured with hepatocytes or with hepatocyte growth factor (HGF), and the differentiation of BM cells into cells expressing liver-specific genes, hepatocyte nuclear factor (HNF) 1α, cytokeratin (CK) 8, α-fetoprotein (AFP), and albumin was investigated by the reverse transcription-polymerase chain reaction. We also investigated the gene expressions of Notch receptor-1 (Notch-1) and its ligand Jagged-1 in BM cell differentiation. Sorted BM cells showed positive for Sca-1 (Ataxin-1) by immunofluorescence staining. Fluorescence activated cell sorter analysis showed that 32.6% of sorted BM cells had a high level of expression of the hematopoietic stem cell marker CD90 (Thy-1). When cultured with hepatocytes, these cells expressed the liver-specific genes HNF1α and CK8 on culture day 3, AFP and albumin on culture day 7. When cultured with HGF (20 ng/ml), the cells expressed HNF1α on day 3 and CK8 on day 7. Gene expressions of Notch-1 and Jagged-1 were detected in cultured BM cells on day 3. These results suggest that the negative selective magnetic cell separation system is useful for the rapid preparation of stem cell-enriched BM cells, and that the Notch signaling pathway plays a role in BM cell differentiation into a hepatocyte lineage in vitro. [Copyright &y& Elsevier]