Astrocyte-neuron communication mediated by the Notch signaling pathway:focusing on glutamate transport and synaptic plasticity

Maintaining glutamate homeostasis after hypoxic ischemia is important for synaptic function and neural cell activity,and regulation of glutamate transport between astrocyte and neuron is one of the important modalities for reducing glutamate accumulation.However,further research is needed to investigate the dynamic changes in and molecular mechanisms of glutamate transport and the effects of glutamate transport on synapses.The aim of this study was to investigate the regulatory mechanisms underlying Notch pathway mediation of glutamate transport and synaptic plasticity.In this study,Yorkshire neonatal pigs(male,age 3 days,weight 1.0–1.5 kg,n=48)were randomly divided into control(sham surgery group)and five hypoxic ischemia subgroups,according to different recovery time,which were then further subdivided into subgroups treated with dimethyl sulfoxide or a Notch pathway inhibitor(N-[N-(3,5-difluorophenacetyl-l-alanyl)]-S-phenylglycine t-butyl ester).Once the model was established,immunohistochemistry,immunofluorescence staining,and western blot analyses of Notch pathway-related proteins,synaptophysin,and glutamate transporter were performed.Moreover,synapse microstructure was observed by transmission electron microscopy.At the early stage(6–12 hours after hypoxic ischemia)of hypoxic ischemic injury,expression of glutamate transporter excitatory amino acid transporter-2 and synaptophysin was downregulated,the number of synaptic vesicles was reduced,and synaptic swelling was observed;at 12–24 hours after hypoxic ischemia,the Notch pathway was activated,excitatory amino acid transporter-2 and synaptophysin expression was increased,and the number of synaptic vesicles was slightly increased.Excitatory amino acid transporter-2 and synaptophysin expression decreased after treatment with the Notch pathway inhibitor.This suggests that glutamate transport in astrocytes-neurons after hypoxic ischemic injury is regulated by the Notch pathway and affects vesicle release and synaptic plasticity through the expression of synaptophysin.

Activation of the Notch signaling pathway promotes neurovascular repair after traumatic brain injury

The Notch signaling pathway plays a key role in angiogenesis and endothelial cell formation, but it remains unclear whether it is involved in vascular repair by endothelial progenitor cells after traumatic brain injury. Therefore, in the present study, we controlled the Notch signaling pathway using overexpression and knockdown constructs. Activation of the Notch signaling pathway by Notch1 or Jagged1 overexpression enhanced the migration, invasiveness and angiogenic ability of endothelial progenitor cells. Suppression of the Notch signaling pathway with Notch1 or Jagged1 si RNAs reduced the migratory capacity, invasiveness and angiogenic ability of endothelial progenitor cells. Activation of the Notch signaling pathway in vivo in a rat model of mild traumatic brain injury promoted neurovascular repair. These findings suggest that the activation of the Notch signaling pathway promotes blood vessel formation and tissue repair after brain trauma.

Notch signaling controls chondrocyte hypertrophy via indirect regulation of Sox9

RBPjk-dependent Notch signaling regulates both the onset of chondrocyte hypertrophy and the progression to terminal chondrocyte maturation during endochondral ossification. It has been suggested that Notch signaling can regulate Sox9 transcription, although how this occurs at the molecular level in chondrocytes and whether this transcriptional regulation mediates Notch control of chondrocyte hypertrophy and cartilage development is unknown or controversial. Here we have provided conclusive genetic evidence linking RBPjk-dependent Notch signaling to the regulation of Sox9 expression and chondrocyte hypertrophy by examining tissuespecific Rbpjk mutant（Prx1Cre;Rbpjkf/f）, Rbpjk mutant/Sox9 haploinsufficient（Prx1Cre;Rbpjkf/f;Sox9f/1）,and control embryos for alterations in SOX9 expression and chondrocyte hypertrophy during cartilage development. These studies demonstrate that Notch signaling regulates the onset of chondrocyte maturation in a SOX9-dependent manner, while Notch-mediated regulation of terminal chondrocyte maturation likely functions independently of SOX9. Furthermore, our in vitro molecular analyses of the Sox9 promoter and Notch-mediated regulation of Sox9 gene expression in chondrogenic cells identified the ability of Notch to induce Sox9 expression directly in the acute setting, but suppresses Sox9 transcription with prolonged Notch signaling that requires protein synthesis of secondary effectors.

Retinal regeneration requires dynamic Notch signaling

Retinal damage in the adult zebrafish induces Müller glia reprogramming to produce neuronal progenitor cells that proliferate and differentiate into retinal neurons.Notch signaling,which is a fundamental mechanism known to drive cell-cell communication,is required to maintain Müller glia in a quiescent state in the undamaged retina,and repression of Notch signaling is necessary for Müller glia to reenter the cell cycle.The dynamic regulation of Notch signaling following retinal damage also directs proliferation and neurogenesis of the Müller glia-derived progenitor cells in a robust regeneration response.In contrast,mammalian Müller glia respond to retinal damage by entering a prolonged gliotic state that leads to additional neuronal death and permanent vision loss.Understanding the dynamic regulation of Notch signaling in the zebrafish retina may aid efforts to stimulate Müller glia reprogramming for regeneration of the diseased human retina.Recent findings identified DeltaB and Notch3 as the ligand-receptor pair that serves as the principal regulators of zebrafish Müller glia quiescence.In addition,multi-omics datasets and functional studies indicate that additional Notch receptors,ligands,and target genes regulate cell proliferation and neurogenesis during the regeneration time course.Still,our understanding of Notch signaling during retinal regeneration is limited.To fully appreciate the complex regulation of Notch signaling that is required for successful retinal regeneration,investigation of additional aspects of the pathway,such as post-translational modification of the receptors,ligand endocytosis,and interactions with other fundamental pathways is needed.Here we review various modes of Notch signaling regulation in the context of the vertebrate retina to put recent research in perspective and to identify open areas of inquiry.

Effect of the Notch signaling pathway on retinal ganglion cells and its neuroprotection in rats with acute ocular hypertension

AIM： To explore the effect of the Notch signaling pathway on retinal ganglion cells（RGCs） and optic nerve in rats with acute ocular hypertension（OH）.METHODS： Totally 48 Sprague-Dawley（SD） rats were included, among which 36 rats were selected to establish acute OH models. OH rats received a single intravitreal injection of 2 μL phosphate buffered solution（PBS） and another group of OH rats received a single intravitreal injection of 10 μmol/L γ-secretase inhibitor（DAPT）. Quantitative real-time polymerase chain reaction（qPCR） and Western blot assay were adopted to determine the mRNA level of Notch and the protein levels of Notch, Bcl-2, Bax, caspase-3, and growth-associated protein 43（GAP-43）. The RGC apoptosis conditions were assessed by TUNEL staining.RESULTS： The OH rats and PBS-injected rats had increased expression levels of Notch1, Bax, caspase-3, and GAP-43, decreased expression levels of Bcl-2, and increased RGC apoptosis, with severer macular edema and RGCs more loosely aligned, when compared with the normal rats. The DAPT-treated rats displayed increased expression levels of Notch1, Bax, caspase-3, and GAP-43, decreased expression levels of Bcl-2, and increased RGC apoptosis, in comparison with the OH rats and PBSinjected rats. RGCs were hardly observed and macular edema became severe in the DAPT-treated rat.CONCLUSION： The Notch signaling pathway may suppress the apoptosis of retinal ganglion cells and enhances the regeneration of the damaged optic nerves in rats with acute OH.

Bevacizumab modulates retinal pigment epithelial-tomesenchymal transition via regulating Notch signaling

AIM: To investigate the effect of bevacizumab treatment on Notch signaling and the induction of epithelial-of-mesenchymal transition(EMT) in human retinal pigment epithelial cells(ARPE-19) in vitro.METHODS: In vitro cultivated ARPE-19 cells were treated with 0.25 mg/m L bevacizumab for 12, 24, and 48 h.Cell morphology changes were observed under an inverted microscope. The expression of zonula occludens-1(ZO-1), vimentin and Notch-1 intracellular domain(NICD) was examined by immunofluorescence.The m RNA levels of ZO-1, α-SMA, Notch-1, Notch-2,Notch-4, Dll4, Jagged-1, RBP-Jk and Hes-1 expression were evaluated with quantitative real-time polymerase chain reaction(q RT-PCR). The protein levels of α-SMA,NICD, Hes-1 and Dll-4 expression were examined with Western blot.RESULTS: Bevacizumab stimulation increased the expression of α-SMA and vimentin in ARPE-19 cells which changed into spindle-shaped fibroblast-like cells.Meanwhile, the m RNA expression of Hes-1 increased and the protein expression of Hes-1 and NICD also increased, which Notch signaling was activated. The m RNA expression of Notch-1, Jagged-1 and RBP-Jk increased at 48 h, and while Dll4 m RNA and protein expression did not change after bevacizumab treatment.CONCLUSION: Jagged-1/Notch-1 signaling may play a critical role in bevacizumab-induced EMT in ARPE-19 cells, which provides a novel insight into the pathogenesis of intravitreal bevacizumab-associated complication.

Scalp acupuncture Yikang therapy on Baihui(GV20),Sishencong(EX-HN1),Zhisanzhen,Niesanzhen improves neurobehavior in young rats with cerebral palsy through Notch signaling pathway

OBJECTIVE:To investigate the efficacy of scalp acupuncture Yikang therapy on Baihui(GV20),Sishencong(EX-HN1),Zhisanzhen,Niesanzhen,on neurobehavior in young rats with cerebral palsy based on Notch signaling pathway.METHODS:Thirty 7-day-old rats were randomly divided into sham,model and acupuncture,10 rats in each group.The cerebral palsy model was established by the accepted modeling method,the acupuncture group selected"Baihui(GV20)","Sishencong(EX-HN1)","Zhisanzhen"and"Niesanzhen"for intervention 24 h after the model was made.The body masses were recorded before and after the treatment,respectively.After the intervention,the rats were subjected to suspension experiment,slope experiment,tactile stimulation experiment and Morris water maze experiment.After the end of the experiment,the morphological changes of hippocampal histology were observed by hematoxylineosin(HE)staining under light microscope,and the expression of Notch1,Notch3 and Hes5 were detected by Western blot and quantitative real-time polymerase chain reaction(PCR).RESULTS:The changes in body mass of the rats in each group were different;in behavioral experiments,compared with the sham,the suspension time of the model was shortened,the slope experiment,tactile stimulation experiment,and escape latency time were prolonged,and the number of platform crossing was reduced in the model,compared with the model,the suspension time of the acupuncture was prolonged,the slope experiment,tactile stimulation experiment,and escape latency time were shortened,and the number of platform crossing times was increased;HE staining showed severe hippocampal damage in the model and reduced hippocampal damage in the acupuncture.Western Blot and real-time fluorescence quantitative PCR showed that the expression of Notch1,Notch3 and Hes5 were increased in the model and the expression of Notch1,Notch3,Hes5 in acupuncture were decreased.CONCLUSIONS:Scalp acupuncture Yikang therapy may improve neurobehavior and reduce brain injury in rats with cerebral palsy by downregulating the expression of Notch1,Notch3,and Hes5.

Notch信号通路——对健康和疾病的机械论观点

The Notch signaling pathway is evolutionarily conserved across metazoan species and plays key roles in many physiological processes.The Notch receptor is activated by two families of canonical ligands(Deltalike and Serrate/Jagged)where both ligands and receptors are single-pass transmembrane proteins usually with large extracellular domains,relative to their intracellular portions.Upon interaction of the core binding regions,presented on opposing cell surfaces,formation of the receptor/ligand complex initiates force-mediated proteolysis,ultimately releasing the transcriptionally-active Notch intracellular domain.This review focuses on structural features of the extracellular receptor/ligand complex,the role of posttranslational modifications in tuning this complex,the contribution of the cell membrane to ligand function,and insights from acquired and genetic diseases.

MicroRNA miR-252-5p regulates the Notch signaling pathway by targeting Rab6 in Drosophila wing development

The Notch signaling pathway plays a central role in the development of various organisms.However,dysregulation of microRNAs(miRNAs),which are crucial regulators of gene expression,can disrupt signaling pathways at all stages of development.Although Notch signaling is involved in wing development in Drosophila,the mechanism underlying miRNA-based regulation of the Notch signaling pathway is unclear.Here,we report that loss of Drosophila miR-252 increases the size of adult wings,whereas the overexpression of miR-252 in specific compartments of larval wing discs leads to patterning defects in the adult wings.The miR-252 overexpression-induced wing phenotypes were caused by aberrant Notch signaling with intracellular accumulation of the full-length Notch receptor during development,which could be due to defects in intracellular Notch trafficking associated with its recycling to the plasma membrane and autophagy-mediated degradation.Moreover,we identified Rab6 as a direct target of miR-252-5p;Rab6 encodes a small Ras-like GTPase that regulates endosomal trafficking pathways.Consistent with this finding,RNAi-mediated downregulation of Rab6 led to similar defects in both wing patterning and Notch signaling.Notably,co-overexpression of Rab6 completely rescued the wing phenotype associated with miR-252 overexpression,further supporting that Rab6 is a biologically relevant target of miR-252-5p in the context of wing development.Thus,our data indicate that the miR-252-5p-Rab6 regulatory axis is involved in Drosophila wing development by controlling the Notch signaling pathway.

The Role of Notch Signaling in Genetic Reticular Pigmentary Disorders

Notch signaling is an essential conserved mechanism through local cell interactions.It regulates cell differentiation,proliferation,and apoptotic,influencing organ formation and morphogenesis.Notch signaling plays a vital role in both development of melanocyte during embryogenesis and maintenance of melanocyte stem cells.POFUT1,POGLUT1,ADAM10,presenilin enhancer-2,and nicastrin genes are pathogenic genes of genetic reticular pigmentation diseases Dowling-Degos disease,reticulate acropigmentation of Kitamura,and acne inversa with pigment abnormalities separately.And they are all vital genes in Notch signaling pathway.This group of pigmentary diseases have similarities and overlaps in clinical manifestations and pathological characteristics.We review the essential role of Notch signaling in genetic reticular pigmentary disorders,and discuss the underlying mechanisms behind dysfunction of melanocyte induced by gene mutations in Notch signaling.

Inhibition of Notch 1 signaling in the subacute stage after stroke promotes striatal astrocyte-derived neurogenesis

Inhibition of Notch1 signaling has been shown to promote astrocyte-derived neurogenesis after stroke.To investigate the regulatory role of Notch1 signaling in this process,in this study,we used a rat model of stroke based on middle cerebral artery occlusion and assessed the behavior of reactive astrocytes post-stroke.We used theγ-secretase inhibitor N-[N-(3,5-diuorophenacetyl)-1-alanyl]-S-phenylglycine t-butylester(DAPT)to block Notch1 signaling at 1,4,and 7 days after injury.Our results showed that only administration of DAPT at 4 days after stroke promoted astrocyte-derived neurogenesis,as manifested by recovery of white matter fiber bundle integrity on magnetic resonance imaging,which is consistent with recovery of neurologic function.These findings suggest that inhibition of Notch1 signaling at the subacute stage post-stroke mediates neural repair by promoting astrocyte-derived neurogenesis.

Role of Notch signaling in regulating innate immunity and inflammation in health and disease

The Notch signaling pathway is conserved from Drosophila to mammals and is critically involved in developmental processes. In the immune system, it has been established that Notch signaling regulates multiple steps of T and B cell development in both central and peripheral lymphoid organs. Relative to the well documented role of Notch signaling in lymphocyte development, less is known about its role in regulating myeloid lineage development and function, especially in the context of acute and chronic inflammation. In this review article, we will describe the evidence accumulated during the recent years to support a key regulatory role of the Notch pathway in innate immune and inflammatory responses and discuss the potential implications of such regulation for pathogenesis and therapy of inflammatory disorders.

Direct regulation of interleukin-6 expression by Notch signaling in macrophages

Interleukin-6 （IL-6） is a pleiotropic, pro-inflammatory cytokine produced by various types of cells, including macrophages. Within the IL-6 gene promoter region, the signature binding motif of CBFI/Su（H）/Lag-1 （CSL）, a key DNA-binding protein in the Notch signaling pathway, was identified and found to overlap with a consensus nuclear factor （NF）-κB-binding site. Notch signaling is highly conserved and is involved in the regulation of biological functions in immune cells. In this study, we investigated the role of Notch signaling in the regulation of the IL-6transcript in murine macrophages. The upregulation of Notch1 protein levels and the appearance of cleaved Notch1 （Va11744） correlated well with the increased IL-6 mRNA expression levels in murine primary bone marrow-derived macrophages （BMMφ） after activation by lipopolysaccharide （LPS） together with interferon-gamma （IFN-γ）. Treatment of BMMφ with the γ-secretase inhibitor IL-CHO to suppress the transduction of Notch signaling resulted in a partial decrease in the level of IL-6mRNA and the amount of I L-6 protein produced. In contrast, the overexpression of a constitutively activated intracellular Notch I protein （N^IC） in the RAW264.7 macrophage-like cell line resulted in significantly higher IL-6transcript expression levels than in cells transfected with the empty vector control. The NF-κB inhibitor completely abrogated IL-6 mRNA expression induced by the overexpression of N^IC. Chromatin immunoprecipitation （CHIP） using an anti-Notch1 antibody demonstrated that Notch 1 is associated with the IL-6promoter in RAW264.7 cells activated by LPS/IFN-γ but not in unstimulated cells. Taken together, these results strongly suggest that Notch 1 positively regulates IL-6 expression via NF-κB in activated macrophages.

The Notch signaling pathway in retinal dysplasia and retina vascular homeostasis

The retina is one of the most essential elements of vision pathway in vertebrate. The dysplasia of retina cause congenital blindness or vision disability in individuals, and the misbalance in adult retinal vascular homeostasis leads to neo adults, such as diabetic retinopathy or age-related macular degeneration. Many developmental signaling pathways are involved in the process of retinal development and vascular homeostasis. Among them, Notch signaling pathway has long been studied, and Notch signaling-interfered mouse models show both neural retina dysplasia and vascular abnormality. In this review, we discuss the roles of Notch signaling in the maintenance of retinal progenitor cells, specification of retinal neurons and glial cells, and the sustaining of retina vascular homeostasis, especially from the aspects of conditional knockout mouse models. The potential of Notch signal manipulation may provide a powerful cell fate- and neovascularization-controUing tool that could have important applications in treatment of retinal diseases.

Notch signaling： a novel regulating differentiation mechanism of human umbilical cord blood-derived mesenchymal stem cells into insulin-producing cells in vitro

Background Human umbilical cord blood-derived mesenchymal stem cells （UCB-MSCs） could be induced to differentiate into insulin producing cells （IPCs） in vitro, which have good application potential in the cell replacement treatment of type-1 diabetes. However, the mechanisms regulating this differentiation have remained largely unknown. Notch signaling is critical in cell differentiation. This study investigated whether Notch signaling could regulate the IPCs differentiation of human UCB-MSCs. Methods Using an interfering Notch signaling protocol in vitro, we studied the role of Notch signaling in differentiation of human UCB-MSCs into IPCs. In a control group the induction took place without interfering Notch signaling. Results Human UCB-MSCs expressed the genes of Notch receptors （Notch 1 and Notch 2） and ligands （Jagged 1 and Deltalike 1）. Human UCB-MSCs with over-expressing Notch signaling in differentiation resulted in the down-regulation of insulin gene level, proinsulin protein expression, and insulin-positive cells percentage compared with the control group. These results showed that over-expressing Notch signaling inhibited IPCs differentiation. Conversely, when Notch signaling was attenuated by receptor inhibitor, the induced cells increased on average by 3.06-fold （n=-4, P 〈0.001） in insulin gene level, 2.60-fold （n=-3, P 〈0.02） in proinsulin protein expression, and 1.62-fold （n=-6, P 〈0.001） in the rate of IPCs compared with the control group. Notch signaling inhibition significantly promoted IPCs differentiation with about 40% of human UCB-MSCs that converted to IPCs, but these IPCs were not responsive to glucose challenge very well both in vitro and in vivo. Hence, further research has to be carried out in the future. Conclusions Notch signaling may be an important mechanism regulating IPCs differentiation of human LICB-MSCs in vitro and Notch signaling inhibition may be an efficient way to increase the number of IPCs, which may resolve the shortage of islet of cell replacement treatment of type-1 diabetes.

Notch signaling regulates expression of Mcl-1 andapoptosis in PPD-treated macrophages

Macrophages are cellular targets for infection by bacteria and viruses. The fate of infected macrophages plays a key role in determining the outcome of the host immune response. Apoptotic cell death of macrophages is considered to be a protective host defense that eliminates pathogens and infected cells. In this study, we investigated the involvement of Notch signaling in regulating apoptosis in macrophages treated with tuberculin purified protein derivative （PPD）. Murine bone marrow-derived macrophages （BMMs） treated with PPD or infected with Mycobacterium bovis Bacillus Calmette-Guerin （BCG） induced upregulation of Notch1. This upregulation correlated well with the upregulation of the anti-apoptotic gene mcl-1 both at the transcriptional and translational levels. Decreased levels of Notch I and Mcl- 1 were observed in BMM treated with PPD when a gamma secretase inhibitor （GSI）, which inhibits the processing of Notch receptors, was used. Moreover, silencing Notch1 in the macrophage-like cell line RAW264.7 decreased Mcl-1 protein expression, suggesting that Notch1 is critical for Mcl-1 expression in macrophages. A significant increase in apoptotic cells was observed upon treatment of BMM with PPD in the presence of GSI compared to the vehicle-control treated cells. Finally, analysis of the mcl-1 promoter in humans and mice revealed a conserved potential CSURBP-Jκ binding site. The association of Notch I with the mcl-1 promoter was confirmed by chromatin immunoprecipitation. Taken together, these results indicate that Notch I inhibits apoptosis of macrophages stimulated with PPD by directly controlling the mcl-1 promoter.

The roles and activation of endocardial Notch signaling in heart regeneration

As a highly conserved signaling pathway in metazoans,the Notch pathway plays important roles in embryonic development and tissue regeneration.Recently,cardiac injury and regeneration have become an increasingly popular topic for biomedical research,and Notch signaling has been shown to exert crucial functions during heart regeneration as well.In this review,we briefly summarize the molecular functions of the endocardial Notch pathway in several cardiac injury and stress models.Although there is an increase in appreciating the importance of endocardial Notch signaling in heart regeneration,the mechanism of its activation is not fully understood.This review highlights recent findings on the activation of the endocardial Notch pathway by hemodynamic blood flow change in larval zebrafish ventricle after partial ablation,a process involving primary cilia,mechanosensitive ion channel Trpv4 and mechanosensitive transcription factor Klf2.

Inscuteable maintains type I neuroblast lineage identity via Numb/Notch signaling in the Drosophila larval brain

In the Drosophila larval brain, type I and type Ⅱ neuroblasts（NBs） undergo a series of asymmetric divisions which give rise to distinct progeny lineages. The intermediate neural progenitors（INPs） exist only in type Ⅱ NB lineages. In this study, we reveal a novel function of Inscuteable（Insc） that acts to maintain type I NB lineage identity. In insc type I NB clones of mosaic analyses with a repressible cell marker（MARCM）, the formation of extra Deadpan（Dpn）tNB-like and GMC-like cells is observed. The lack of Insc leads to the defective localization and segregation of Numb during asymmetric cell division. By the end of cytokinesis, this results in insufficient Numb in ganglion mother cells（GMCs）. The formation of extra Deadpan（Dpn）tcells in insc clones is prevented by the attenuation of Notch activity. This suggests that Insc functions through the Numb/Notch signaling pathway. We also show that in the absence of Insc in type I NB lineages, the cellular identity of GMCs is altered where they adopt an INP-like cell fate as indicated by the initiation of Dpn expression accompanied by a transient presence of Earmuff（Erm）.These INP-like cells have the capacity to divide multiple times. We conclude that Insc is necessary for the maintenance of type I NB lineage identity. Genetic manipulations to eliminate most type I NBs with overproliferating type Ⅱ NBs in the larval brain lead to altered circadian rhythms and defective phototaxis in adult flies. This indicates that the homeogenesis of NB lineages is important for the adult＇s brain function.

Notch signaling in hepatocellular carcinoma:molecular targetingin an advanced disease

The use of alternative therapeutic approaches in advanced carcinogenesis is a growing investigative base.One such cancer,primary liver cancer,is one of the most commonly occurring cancers worldwide and often presents in late stage disease consequently preventing traditional curative modalities.As a result,hepatocellular carcinoma(HCC),representing the majority of primary liver cancer,is the third most common cause of cancer-related deaths globally.Survival rates are linked to stage of presentation as well as concomitant cirrhosis limiting the 5-year survival in these patients to<20%.Alternative strategies are in dire need as patients in this cohort have limited palliative options.Currently,sorafenib is the only approved systemic therapy;however,it has a limited survival advantage and low effi cacy prompting the empirical need for further evaluation.Understanding of cancer therapy has led to an enhanced focus on the Notch pathway as a potential target for advanced HCC.Notch signaling is a critical component of development and cell fate and has been linked to various modalities including liver regeneration and as a key driver in carcinogenesis.In this review,we will provide a review of the current status of the Notch signaling in liver cancer and of Notch as an alternative potential strategy for advanced HCC.

dBrms1 Acts as a Positive Regulator of Notch Signaling in Drosophila Wing

The highly conserved Notch signaling is precisely regulated at different steps in a series of developmental events. However, little is known about the regulation of Notch receptor at transcriptional level. Here, we demonstrate that dBrmsl is involved in regulating Notch signaling in Drosophila wing. We show that knockdown of dBrmsl by RNA interference （RNAi） in wing disc suppresses the expression of Notch signaling target genes wingless （wg）, cut and Enhancer of split m8 [E（spl）m8]. Consistently, the levels of Wg and Cut are reduced in the dBrmsl mutant clones. Importantly, loss of dBrmsl leads to significant reduction of Notch proteins. Furthermore, depletion of dBrmsl results in apparent downregulation of Notch transcription in the wing disc. Moreover, we find that dBrmsl is functionally conserved with human Breast cancer metastasis suppressor 1 like （hBRMSIL） in the modulation of Notch signaling. Taken together, our data provide important insights into the biological function of dBrmsl in regulating Notch signaling.